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Sample records for samples long-term memory

  1. 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 history

  2. A cost of long-term memory in Drosophila

    OpenAIRE

    Mery, Frederic; Kawecki, Tadeusz J.

    2005-01-01

    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...

  3. Long-term expression of human contextual fear and extinction memories involves amygdala, hippocampus and ventromedial prefrontal cortex: a reinstatement study in two independent samples.

    Science.gov (United States)

    Lonsdorf, Tina B; Haaker, Jan; Kalisch, Raffael

    2014-12-01

    Human context conditioning studies have focused on acquisition and extinction. Subsequent long-term changes in fear behaviors not only depend on associative learning processes during those phases but also on memory consolidation processes and the later ability to retrieve and express fear and extinction memories. Clinical theories explain relapse after successful exposure-based treatment with return of fear memories and remission with stable extinction memory expression. We probed contextual fear and extinction memories 1 week (Day8) after conditioning (Day1) and subsequent extinction (Day2) by presenting conditioned contexts before (Test1) and after (Test2) a reinstatement manipulation. We find consistent activation patterns in two independent samples: activation of a subgenual part of the ventromedial prefrontal cortex before reinstatement (Test1) and (albeit with different temporal profiles between samples) of the amygdala after reinstatement (Test2) as well as up-regulation of anterior hippocampus activity after reinstatement (Test2 > Test1). These areas have earlier been implicated in the expression of cued extinction and fear memories. The present results suggest a general role for these structures in defining the balance between fear and extinction memories, independent of the conditioning mode. The results are discussed in the light of hypotheses implicating the anterior hippocampus in the processing of situational ambiguity. PMID:24493848

  4. Long term memory in extreme returns of financial time series

    Science.gov (United States)

    Muchnik, Lev; Bunde, Armin; Havlin, Shlomo

    2009-10-01

    It is well known that while daily price returns of financial markets are uncorrelated, their absolute values (‘volatility’) are long-term correlated. Here we provide evidence that certain subsequences of the returns themselves also exhibit long-term memory. These subsequences consist of maxima (or minima) of returns in consecutive time windows of R days. Our analysis shows that for both stocks and currency exchange rates, long-term correlations are significant for R?4. We argue that this long-term memory which is similar to that observed in volatility clustering sheds further insight on price dynamics that might be used for risk estimation.

  5. Long Term Immunological Memory to Vaccinia Virus

    OpenAIRE

    Halla Halldórsdóttir 1987

    2012-01-01

    The smallpox vaccine is a vaccine of considerable importance. It made the eradication of smallpox possible and has been shown to elicit humoral and cellular immunity that can last for over half a century. Due to concerns about smallpox being used as a biological weapon, the immune response to the vaccine is of considerable interest. In this study, long term B- and T-cell responses were investigated in individuals with extreme responses to the smallpox vaccine when they were immunised over thr...

  6. Long-term memories in online users' selecting activities

    Science.gov (United States)

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

    2014-07-01

    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.

  7. Long-term memory impairment in patients with focal epilepsy.

    Science.gov (United States)

    Hoppe, Christian; Elger, Christian E; Helmstaedter, Christoph

    2007-01-01

    In temporal lobe epilepsy, long-term memory disturbance starts early in life mainly affecting declarative memory. Primary impairment of episodic memory often results in reduced semantic and autobiographic memory. Neuropsychological performance predicts academic achievement and everyday life functioning while subjective memory complaints are highly correlated with depression. Memory impairment is also influenced by initial brain damage, developmental retardation and dynamic factors (e.g., seizure frequency, medication). Damage of functional tissue, low mental reserve capacity, and poor seizure outcome increase the risk for postsurgical memory impairment whereas functional release due to seizure freedom counteracts negative impact. Preliminary findings indicate that postsurgical training improves memory deficits and encourage further research. PMID:18047597

  8. Examining the Long-Term Stability of Overgeneral Autobiographical Memory

    OpenAIRE

    Jennifer A. Sumner; Mineka, Susan; Zinbarg, Richard E.; Craske, Michelle G; Vrshek-Schallhorn, Suzanne; Epstein, Alyssa

    2013-01-01

    Overgeneral autobiographical memory (OGM) is a proposed trait-marker for vulnerability to depression, but relatively little work has examined its long-term stability. This study investigated the stability of OGM over several years in 271 late adolescents and young adults participating in a larger longitudinal study of risk for emotional disorders. The Autobiographical Memory Test (AMT) was administered twice, with test-retest intervals ranging from approximately 3 to 6 years. There was eviden...

  9. Merging of long-term memories in an insect.

    Science.gov (United States)

    Hunt, Kathryn L; Chittka, Lars

    2015-03-16

    Research on comparative cognition has largely focused on successes and failures of animals to solve certain cognitive tasks, but in humans, memory errors can be more complex than simple failures to retrieve information [1, 2]. The existence of various types of "false memories," in which individuals remember events that they have never actually encountered, are now well established in humans [3, 4]. We hypothesize that such systematic memory errors may be widespread in animals whose natural lifestyle involves the processing and recollection of memories for multiple stimuli [5]. We predict that memory traces for various stimuli may "merge," such that features acquired in distinct bouts of training are combined in an animal's mind, so that stimuli that have never been viewed before, but are a combination of the features presented in training, may be chosen during recall. We tested this using bumblebees, Bombus terrestris. When individuals were first trained to a solid single-colored stimulus followed by a black and white (b/w)-patterned stimulus, a subsequent preference for the last entrained stimulus was found in both short-term- and long-term-memory tests. However, when bees were first trained to b/w-patterned stimuli followed by solid single-colored stimuli and were tested in long-term-memory tests 1 or 3 days later, they only initially preferred the most recently rewarded stimulus, and then switched their preference to stimuli that combined features from the previous color and pattern stimuli. The observed merging of long-term memories is thus similar to the memory conjunction error found in humans [6]. PMID:25728692

  10. Long-term memory in electricity prices: Czech market evidence.

    Czech Academy of Sciences Publication Activity Database

    Krištoufek, Ladislav; Lu?á?ková, P.

    2013-01-01

    Ro?. 63, ?. 5 (2013), s. 407-424. ISSN 0015-1920 R&D Projects: GA ?R GA402/09/0965 Grant ostatní: GA ?R(CZ) GAP402/11/0948 Institutional support: RVO:67985556 Keywords : electricity * long-term memory Subject RIV: AH - Economics Impact factor: 0.358, year: 2013 http://library.utia.cas.cz/separaty/2014/E/kristoufek-0427660.pdf

  11. Long-Term Ecological Monitoring Field Sampling Plan for 2007

    Energy Technology Data Exchange (ETDEWEB)

    T. Haney

    2007-07-31

    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.

  12. 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

  13. Infants long-term memory for complex music

    Science.gov (United States)

    Ilari, Beatriz; Polka, Linda; Costa-Giomi, Eugenia

    2002-05-01

    In this study we examined infants' long-term memory for two complex pieces of music. A group of thirty 7.5 month-old infants was exposed daily to one short piano piece (i.e., either the Prelude or the Forlane by Maurice Ravel) for ten consecutive days. Following the 10-day exposure period there was a two-week retention period in which no exposure to the piece occurred. After the retention period, infants were tested on the Headturn Preference Procedure. At test, 8 different excerpts of the familiar piece were mixed with 8 different foil excerpts of the unfamiliar one. Infants showed a significant preference for the familiar piece of music. A control group of fifteen nonexposed infants was also tested and showed no preferences for either piece of music. These results suggest that infants in the exposure group retained the familiar music in their long-term memory. This was demonstrated by their ability to discriminate between the different excerpts of both the familiar and the unfamiliar pieces of music, and by their preference for the familiar piece. Confirming previous findings (Jusczyk and Hohne, 1993; Saffran et al., 2000), in this study we suggest that infants can retain complex pieces of music in their long-term memory for two weeks.

  14. Greater emotional arousal predicts poorer long-term memory of communication skills in couples

    OpenAIRE

    Baucom, Brian R.; Weusthoff, Sarah; Atkins, David; Hahlweg, Kurt

    2012-01-01

    Many studies have examined the importance of learning skills in behaviorally based couple interventions but none have examined predictors of long-term memory for skills. Associations between emotional arousal and long-term recall of communication skills delivered to couples during a behaviorally based relationship distress prevention program were examined in a sample of 49 German couples. Fundamental frequency (f0), a vocal measure of encoded emotional arousal, was measured during pre-treatme...

  15. Accessing forgotten memory traces from long-term memory via visual movements

    OpenAIRE

    Càmara, Estela; Fuentemilla, Lluís

    2014-01-01

    Because memory retrieval often requires overt responses, it is difficult to determine to what extend forgetting occurs as a problem in explicit accessing of long-term memory traces. In this study, we used eye-tracking measures in combination with a behavioral task that favored high forgetting rates to investigate the existence of memory traces from long-term memory in spite of failure in accessing them consciously. In two experiments, participants were encouraged to encode a large set of soun...

  16. Shared component processes in working memory and long-term memory : Insights from functional brain imaging

    OpenAIRE

    Marklund, Petter

    2004-01-01

    Marklund, P. (2004). Shared component processes in working memory and long-term memory: Insights from functional brain imaging. Department of Psychology, Umeå University, S-901 87 Umeå SwedenRecent findings from functional neuroimaging studies have shown pronounced similarities in the functional brain activity patterns associated with tests of various cognitive functions. This thesis investigates shared component processes in working memory and declarative long-term memory. Study 1 showed a c...

  17. Emotional Context and Visual Long-Term Memory.

    Science.gov (United States)

    Xie, Weizhen; Zhang, Weiwei

    2015-09-01

    Emotion exerts great impacts on memory. For instance, negative emotions can enhance memory encoding or reduce retrieval-induced forgetting. In addition, congruent mood states between encoding and retrieval (e.g., negative emotions at both stages) can also improve memory performance relative to incongruent mood states (e.g., negative emotion in encoding, but positive encoding in retrieval). However, it is unclear whether mood congruency between memory retrieval and encoding increases the probability of successful retrieval or enhance the quality of retrieved memory representations. The current study directly tested these two hypotheses using a visual long-term memory recall task. In the study phase, participants remembered a sequence of colorful objects. Each object was presented on top of a gray-scale negative image from the International Affective Picture System (IAPS). Participants gave a valence rating for each IAPS image for emotion induction. In the test phase, participants reconstructed the colors of the previously studied objects by continuously adjusting their colors under negative or positive emotional contexts using the same emotion induction procedure as that from the study phase. Negative IAPS images used for the negative emotional context were different from, but with matched valence as, those in the study phase. Positive images for the positive emotional context had comparable arousal levels as negative images. We found that memories encoded in negative context but retrieved in positive context (the incongruent condition) were less precise than memories encoded and retrieved both in negative context (the congruent condition). In contrast, no significant difference in the probability of successful retrieval was found between the two conditions. Follow-up experiments ruled out alternative interpretations that either negative emotion or positive emotion at the retrieval alone could account for the memory quality effects observed in the first experiment. Taken together, the present results support a resolution account for mood-congruency memory effect. Meeting abstract presented at VSS 2015. PMID:26325776

  18. Non-Climate Long Term Memory in Tree Ring Proxies

    Science.gov (United States)

    Zhang, Huan; Yuan, Naiming; Luterbacher, Juerg; Xoplaki, Elena; Werner, Johannes

    2015-04-01

    Long term memory (LTM) scaling behavior in tree-ring proxies and regional mean temperature/rainfall reconstructions has been analyzed and compared with the ones found in instrumental temperature and rainfall records. Detrended fluctuation analysis is employed to detect LTM, and its scaling exponent ? is used to measure LTM. The results show mean ? = 0.8 in tree-ring width records, and mean ? = 0.7 in tree-ring maximum density from 1yr up to 100yrs, while ? ˜ 0.6 (? = 0.5) is found in instrumental data of temperature (rainfall). By comparing the no-memory data (? = 0.5) with data with artificial LTM (? > 0.5), we demonstrate the potential influences of LTM on climate reconstructions and call special cautions in the variability analysis of proxy chronologies or reconstructions, especially in quantifying: i) trends; ii) climate anomalies; iii) extreme events.

  19. Modified climate with long term memory in tree ring proxies

    Science.gov (United States)

    Zhang, Huan; Yuan, Naiming; Esper, Jan; Werner, Johannes P.; Xoplaki, Elena; Büntgen, Ulf; Treydte, Kerstin; Luterbacher, Jürg

    2015-08-01

    Long term memory (LTM) scaling behavior in worldwide tree-ring proxies and subsequent climate reconstructions is analyzed for and compared with the memory structure inherent to instrumental temperature and precipitation data. Detrended fluctuation analysis is employed to detect LTM, and its scaling exponent ? is used to evaluate LTM. The results show that temperature and precipitation reconstructions based on ring width measurements (mean ? =0.8) contain more memory than records based on maximum latewood density (mean ? =0.7). Both exceed the memory inherent to regional instrumental data (? =0.6 for temperature, ? =0.5 for precipitation) in the time scales ranging from 1 year up to 50 years. We compare memory-free (? =0.5) pseudo-instrumental precipitation data with pseudo-reconstructed precipitation data with LTM (? \\gt 0.5), and demonstrate the biasing influences of LTM on climate reconstructions. We call for attention to statistical analysis with regard to the variability of proxy-based chronologies or reconstructions, particularly with respect to the contained (i) trends, (ii) past warm/cold period and wet/dry periods; and (iii) extreme events.

  20. Examining the long-term stability of overgeneral autobiographical memory.

    Science.gov (United States)

    Sumner, Jennifer A; Mineka, Susan; Zinbarg, Richard E; Craske, Michelle G; Vrshek-Schallhorn, Suzanne; Epstein, Alyssa

    2014-01-01

    Overgeneral autobiographical memory (OGM) is a proposed trait-marker for vulnerability to depression, but relatively little work has examined its long-term stability. This study investigated the stability of OGM over several years in 271 late adolescents and young adults participating in a larger longitudinal study of risk for emotional disorders. The Autobiographical Memory Test (AMT) was administered twice, with test-retest intervals ranging from approximately 3 to 6 years. There was evidence of significant but modest stability in OGM over several years. Specifically, Spearman rank correlations (?s) between the proportions of specific and categoric memories generated on the two AMTs were .31 and .32, respectively. We did not find evidence that the stability of OGM was moderated by the length of the test-retest interval. Furthermore, the stability coefficients for OGM for individuals with and without a lifetime history of major depressive disorder (MDD) were relatively similar in magnitude and not significantly different from one another (?s=.34 and .42 for the proportions of specific and categoric memories for those with a history of MDD; ?s=.31 for both the proportions of specific and categoric memories for those without a history of MDD). Implications for the conceptualisation of OGM are discussed. PMID:23439226

  1. REGULAR REHEARSAL HELPS IN CONSOLIDATION OF LONG TERM MEMORY

    Directory of Open Access Journals (Sweden)

    Milind Parle

    2006-03-01

    Full Text Available Memory, one of the most complex functions of the brain comprises of multiple components such as perception, registration, consolidation, storage, retrieval and decay. The present study was undertaken to evaluate the impact of different training sessions on the retention capacity of rats. The capacity of retention of learnt task was measured using exteroceptive behavioral models such as Hexagonal swimming pool apparatus, Hebb-Williams maze and Elevated plus-maze. A total of 150 rats divided into fifteen groups were employed in the present study. The animals were subjected to different training sessions during first three days. The ability to retain the learned task was tested after single, sub-acute, acute, sub-chronic and chronic exposure to above exteroceptive memory models in separate groups of animals. The memory score of all animals was recorded after 72 h, 192 h and 432 h of their last training trial. Rats of single exposure group did not show any effect on memory. Sub-acute training group animals showed improved memory up to 72 h only, where as in acute and sub-chronic training groups this memory improvement was extended up to 192 h. The rats, which were subjected to chronic exposures showed a significant improvement in retention capacity that lasted up to a period of eighteen days. These observations suggest that repeated rehearsals at regular intervals are probably necessary for consolidation of long-term memory. It was observed that sub-acute, acute and sub-chronic exposures, improved the retrieval ability of rats but this memory improving effect was short lived. Thus, rehearsal or training plays a crucial role in enhancing one's capacity of retaining the learnt information

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

    Science.gov (United States)

    Jeneson, Annette; Squire, Larry R.

    2012-01-01

    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…

  3. Regular rehearsal helps in consolidation of long term memory.

    Science.gov (United States)

    Parle, Milind; Singh, Nirmal; Vasudevan, Mani

    2006-01-01

    Memory, one of the most complex functions of the brain comprises of multiple components such as perception, registration, consolidation, storage, retrieval and decay. The present study was undertaken to evaluate the impact of different training sessions on the retention capacity of rats. The capacity of retention of learnt task was measured using exteroceptive behavioral models such as Hexagonal swimming pool apparatus, Hebb-Williams maze and Elevated plus-maze. A total of 150 rats divided into fifteen groups were employed in the present study. The animals were subjected to different training sessions during first three days. The ability to retain the learned task was tested after single, sub-acute, acute, sub-chronic and chronic exposure to above exteroceptive memory models in separate groups of animals. The memory score of all animals was recorded after 72 h, 192 h and 432 h of their last training trial. Rats of single exposure group did not show any effect on memory. Sub-acute training group animals showed improved memory up to 72 h only, where as in acute and sub-chronic training groups this memory improvement was extended up to 192 h. The rats, which were subjected to chronic exposures showed a significant improvement in retention capacity that lasted up to a period of eighteen days. These observations suggest that repeated rehearsals at regular intervals are probably necessary for consolidation of long-term memory. It was observed that sub-acute, acute and sub-chronic exposures, improved the retrieval ability of rats but this memory improving effect was short lived. Thus, rehearsal or training plays a crucial role in enhancing one's capacity of retaining the learnt information. Key PointsThe present study underlines the importance of regular rehearsals in enhancing one's capacity of retaining the learnt information. " Sub-acute, acute & sub-chronic rehearsals result in storing of information for a limited period of time.Quick decay of information or forgetting is a natural continuously active process designed to wipe out unnecessary and useless information.The capacities of grasping, understanding and memory are all crucial for career growth.Single exposure to a new environment is not sufficient enough to form a permanent memory trace in brain. PMID:24198684

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

    KAUST Repository

    Bag, A.

    2014-06-01

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

  5. Making long-term memories in minutes: a time pattern from memory research in education

    OpenAIRE

    PaulKelley; TerryWhatson

    2013-01-01

    Memory systems select from environmental stimuli those to encode permanently. Repeated stimuli separated by timed spaces without stimuli can initiate Long-Term Potentiation (LTP) and long-term memory (LTM) encoding. These processes occur in time scales of minutes, and has been demonstrated in many species. This study reports on using a specific timed pattern of three repeated stimuli separated by ten-minute spaces drawn from both behavioural and laboratory studies of LTP and LTM encoding. ...

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

    OpenAIRE

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

    2012-01-01

    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...

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

    OpenAIRE

    Jeneson, Annette; Squire, Larry R.

    2012-01-01

    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...

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

    Science.gov (United States)

    Menard, Marie-Claude; Belleville, Sylvie

    2009-01-01

    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…

  9. Accessing forgotten memory traces from long-term memory via visual movements

    Directory of Open Access Journals (Sweden)

    Estela Camara

    2014-11-01

    Full Text Available Because memory retrieval often requires overt responses, it is difficult to determine to what extend forgetting occurs as a problem in explicit accessing of long-term memory traces. In this study, we used eye-tracking measures in combination with a behavioural task that favoured high forgetting rates to investigate the existence of memory traces from long-term memory in spite of failure in accessing them consciously. In 2 experiments, participants were encouraged to encode a large set of sound-picture-location associations. In a later test, sounds were presented and participants were instructed to visually scan, before a verbal memory report, for the correct location of the associated pictures in an empty screen. We found the reactivation of associated memories by sound cues at test biased oculomotor behaviour towards locations congruent with memory representations, even when participants failed to consciously provide a memory report of it. These findings reveal the emergence of a memory-guided behaviour that can be used to map internal representations of forgotten memories from long-term memory.

  10. Enhanced long-term memory encoding after parietal neurostimulation.

    Science.gov (United States)

    Jones, Kevin T; Gözenman, Filiz; Berryhill, Marian E

    2014-12-01

    Neurostimulation, e.g., transcranial direct current stimulation (tDCS), shows promise as an effective cognitive intervention. In spite of low spatial resolution, limited penetration, and temporary influence, evidence highlights tDCS-linked cognitive benefits in a range of cognitive domains. The left posterior parietal cortex (PPC) is an accessible node in frontoparietal networks engaged during long-term memory (LTM). Here, we tested the hypothesis that tDCS can facilitate LTM by pairing LTM encoding and retrieval with PPC stimulation. Healthy young adults performed a verbal LTM task (California Verbal Learning Task) with four different stimulation parameters. In Experiment 1, we applied tDCS to left PPC during LTM encoding. In Experiment 2, we applied tDCS just prior to retrieval to test the temporal specificity of tDCS during a LTM task. In later experiments, we tested hemispheric specificity by replicating Experiment 1 while stimulating the right PPC. Experiment 1 showed that tDCS applied during LTM encoding improved the pace of list learning and enhanced retrieval after a short delay. Experiment 2 indicated anodal left PPC tDCS only improved LTM when applied during encoding, and not during maintenance. Experiments 3 and 4 confirmed that tDCS effects were hemisphere specific and that no effects were found after right PPC stimulation during encoding. These findings indicate that anodal tDCS to the PPC helps verbal LTM in healthy young adults under certain conditions. First, when it is applied to the left, not the right, PPC and second, when it is applied during encoding. PMID:25200180

  11. What Infant Memory Tells Us about Infantile Amnesia: Long-Term Recall and Deferred Imitation

    OpenAIRE

    Meltzoff, Andrew N.

    1995-01-01

    Long-term recall memory was assessed using a nonverbal method requiring subjects to reenact a past event from memory (deferred imitation). A large sample of infants (N = 192), evenly divided between 14- and 16-months old, was tested across two experiments. A delay of 2 months was used in Experiment 1 and a delay of 4 months in Experiment 2. In both experiments two treatment groups were used, In one treatment group, motor practice (immediate imitation) was allowed before the delay was imposed;...

  12. Memory Functioning in Children with Reading Disabilities and/or Attention-Deficit/Hyperactivity Disorder: A Clinical Investigation of Their Working Memory and Long-term Memory Functioning

    OpenAIRE

    Kibby, Michelle Y.; Cohen, Morris J

    2008-01-01

    We examined memory functioning in children with reading disabilities (RD), ADHD, and RD/ADHD using a clinic sample with a clinical instrument: the Children’s Memory Scale, enhancing its generalizability. Participants included 23 children with RD, 30 with ADHD, 30 with RD/ADHD, and 30 controls. Children with RD presented with reduced verbal short-term memory (STM) but intact visual STM, central executive (CE) and long-term memory (LTM) functioning. Their deficit in STM appeared specific to tas...

  13. Deficits in Long-Term Recognition Memory Reveal Dissociated Subtypes in Congenital Prosopagnosia

    OpenAIRE

    Stollhoff, Rainer; Jost, Jürgen; Elze, Tobias; Kennerknecht, Ingo

    2011-01-01

    The study investigates long-term recognition memory in congenital prosopagnosia (CP), a lifelong impairment in face identification that is present from birth. Previous investigations of processing deficits in CP have mostly relied on short-term recognition tests to estimate the scope and severity of individual deficits. We firstly report on a controlled test of long-term (one year) recognition memory for faces and objects conducted with a large group of participants with CP. Long-term recogni...

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

    Directory of Open Access Journals (Sweden)

    MÔNICA R.M. VIANNA

    2000-09-01

    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.

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

    Science.gov (United States)

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

    2007-01-01

    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…

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

    OpenAIRE

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

    2014-01-01

    A biologically relevant event such as finding food under starvation conditions or being poisoned can drive long-term memory (LTM) in a single training session. Neuronal mechanisms by which such a strong reward or punishment induces stable memory are poorly understood. Here we show that distinct subsets of dopamine neurons signal reward for short- and long-term appetitive memories in Drosophila. The temporal dynamics of memory components triggered by the distinct reward signals are complementa...

  17. Metamemory ratings predict long-term changes in reactivated episodic memories

    OpenAIRE

    Yacoby, Amnon; Dudai, Yadin; Mendelsohn, Avi

    2015-01-01

    Reactivation of long-term memory can render the memory item temporarily labile, offering an opportunity to modify it via behavioral or pharmacological intervention. Declarative memory reactivation is accompanied by a metamemory ability to subjectively assess the knowledge available concerning the target item (Feeling of knowing, FOK). We set out to examine whether FOK can predict the extent of change of long-term episodic memories by post-retrieval manipulations. To this end, participants wat...

  18. Late Protein Synthesis-Dependent Phases in CTA Long-Term Memory: BDNF Requirement

    OpenAIRE

    MarthaLEscobar

    2011-01-01

    It has been proposed that long-term memory persistence requires a late protein synthesis-dependent phase, even many hours after memory acquisition. Brain-derived neurotrophic factor (BDNF) is an essential protein synthesis product that has emerged as one of the most potent molecular mediators for long-term synaptic plasticity. Studies in the rat hippocampus have been shown that BDNF is capable to rescue the late-phase of long-term potentiation as well as the hippocampus-related long-term memo...

  19. The role of the hippocampus in long-term memory: is it memory store or comparator?

    Science.gov (United States)

    Kryukov, V I

    2008-03-01

    Several attempts have been made to reconcile a number of rival theories on the role of the hippocampus in long-term memory. Those attempts fail to explain the basic effects of the theories from the same point of view. We are reviewing the four major theories, and shall demonstrate, with the use of mathematical models of attention and memory, that only one theory is capable of reconciling all of them by explaining the basic effects of each theory in a unified fashion, without altogether sacrificing their individual contributions. The key issue here is whether or not a memory trace is ever stored in the hippocampus itself, and there is no reconciliation unless the answer to that question is that there is not. As a result of the reconciliation that we are proposing, there is a simple solution to several outstanding problems concerning the neurobiology of memory such as: consolidation and reconsolidation, persistency of long term memory, novelty detection, habituation, long-term potentiation, and the multifrequency oscillatory self-organization of the brain. PMID:18431820

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

    OpenAIRE

    Bolduc, François V.; Bell, Kimberly; Cox, Hilary; Broadie, Kendal; Tully, Tim

    2008-01-01

    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.

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

    Science.gov (United States)

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

    2015-01-01

    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

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

    CERN Document Server

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

    2006-01-01

    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...

  3. Anomalous Fluctuations in Autoregressive Models with Long-Term Memory

    Science.gov (United States)

    Sakaguchi, Hidetsugu; Honjo, Haruo

    2015-10-01

    An autoregressive model with a power-law type memory kernel is studied as a stochastic process that exhibits a self-affine-fractal-like behavior for a small time scale. We find numerically that the root-mean-square displacement ?(m) for the time interval m increases with a power law as m? with ? memory kernel.

  4. Word Length Effects in Long-Term Memory

    Science.gov (United States)

    Tehan, Gerald; Tolan, Georgina Anne

    2007-01-01

    The word length effect has been a central feature of theorising about immediate memory. The notion that short-term memory traces rapidly decay unless refreshed by rehearsal is based primarily upon the finding that serial recall for short words is better than that for long words. The decay account of the word length effect has come under pressure…

  5. Lateral Habenula determines long-term storage of aversive memories

    Science.gov (United States)

    Tomaiuolo, Micol; Gonzalez, Carolina; Medina, Jorge H.; Piriz, Joaquin

    2014-01-01

    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 h 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. PMID:24860453

  6. Lateral Habenula determines long-term storage of aversive memories.

    Directory of Open Access Journals (Sweden)

    Micol Tomaiuolo

    2014-05-01

    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.

  7. Debra, a Protein Mediating Lysosomal Degradation, Is Required for Long-Term Memory in Drosophila

    OpenAIRE

    Kottler, Benjamin; Lampin-Saint-Amaux, Aurélie; Comas, Daniel; Preat, Thomas; Goguel, Valérie

    2011-01-01

    A central goal of neuroscience is to understand how neural circuits encode memory and guide behavior changes. Many of the molecular mechanisms underlying memory are conserved from flies to mammals, and Drosophila has been used extensively to study memory processes. To identify new genes involved in long-term memory, we screened Drosophila enhancer-trap P(Gal4) lines showing Gal4 expression in the mushroom bodies, a specialized brain structure involved in olfactory memory. This screening led t...

  8. Fatty-Acid Binding Proteins Modulate Sleep and Enhance Long-Term Memory Consolidation in Drosophila

    OpenAIRE

    Gerstner, Jason R.; Vanderheyden, William M; Shaw, Paul J.; LANDRY, CHARLES F.; Yin, Jerry C.P.

    2011-01-01

    Sleep is thought to be important for memory consolidation, since sleep deprivation has been shown to interfere with memory processing. However, the effects of augmenting sleep on memory formation are not well known, and testing the role of sleep in memory enhancement has been limited to pharmacological and behavioral approaches. Here we test the effect of overexpressing the brain-type fatty acid binding protein (Fabp7) on sleep and long-term memory (LTM) formation in Drosophila melanogaster. ...

  9. Anomalous Fluctuations in Autoregressive Models with Long-Term Memory

    CERN Document Server

    Sakaguchi, Hidetsugu

    2015-01-01

    An autoregressive model with a power-law type memory kernel is studied as a stochastic process that exhibits a self-affine-fractal-like behavior for a small time scale. We find numerically that the root-mean-square displacement for the time interval increases with a power law for small time but saturates at sufficiently large time. The exponent changes with the power exponent of the memory kernel.

  10. Massive memory revisited: Limitations on storage capacity for object details in visual long-term memory.

    Science.gov (United States)

    Cunningham, Corbin A; Yassa, Michael A; Egeth, Howard E

    2015-11-01

    Previous work suggests that visual long-term memory (VLTM) is highly detailed and has a massive capacity. However, memory performance is subject to the effects of the type of testing procedure used. The current study examines detail memory performance by probing the same memories within the same subjects, but using divergent probing methods. The results reveal that while VLTM representations are typically sufficient to support performance when the procedure probes gist-based information, they are not sufficient in circumstances when the procedure requires more detail. We show that VLTM capacity, albeit large, is heavily reliant on gist as well as detail. Thus, the nature of the mnemonic representations stored in VLTM is important in understanding its capacity limitations. PMID:26472646

  11. Insulin signaling is acutely required for long-term memory in Drosophila

    OpenAIRE

    Chambers, Daniel B.; Androschuk, Alaura; Rosenfelt, Cory; Langer, Steven; Harding, Mark; Bolduc, Francois V

    2015-01-01

    Memory formation has been shown recently to be dependent on energy status in Drosophila. A well-established energy sensor is the insulin signaling (InS) pathway. Previous studies in various animal models including human have revealed the role of insulin levels in short-term memory but its role in long-term memory remains less clear. We therefore investigated genetically the spatial and temporal role of InS using the olfactory learning and long-term memory model in Drosophila. We found that In...

  12. Biased Competition during Long-term Memory Formation.

    Science.gov (United States)

    Hutchinson, J Benjamin; Pak, Sarah S; Turk-Browne, Nicholas B

    2016-01-01

    A key task for the brain is to determine which pieces of information are worth storing in memory. To build a more complete representation of the environment, memory systems may prioritize new information that has not already been stored. Here, we propose a mechanism that supports this preferential encoding of new information, whereby prior experience attenuates neural activity for old information that is competing for processing. We evaluated this hypothesis with fMRI by presenting a series of novel stimuli concurrently with repeated stimuli at different spatial locations in Experiment 1 and from different visual categories (i.e., faces and scenes) in Experiment 2. Subsequent memory for the novel stimuli could be predicted from the reduction in activity in ventral temporal cortex for the accompanying repeated stimuli. This relationship was eliminated in control conditions where the competition during encoding came from another novel stimulus. These findings reveal how prior experience adaptively guides learning toward new aspects of the environment. PMID:26439270

  13. Regular Rehearsal Helps in Consolidation of Long Term Memory

    OpenAIRE

    Milind Parle; Nirmal Singh1; Mani Vasudevan

    2006-01-01

    Memory, one of the most complex functions of the brain comprises of multiple components such as perception, registration, consolidation, storage, retrieval and decay. The present study was undertaken to evaluate the impact of different training sessions on the retention capacity of rats. The capacity of retention of learnt task was measured using exteroceptive behavioral models such as Hexagonal swimming pool apparatus, Hebb-Williams maze and Elevated plus-maze. A total of 150 rats divided in...

  14. Two Waves of Transcription Are Required for Long-Term Memory in the Honeybee

    Science.gov (United States)

    Lefer, Damien; Perisse, Emmanuel; Hourcade, Benoit; Sandoz, JeanChristophe; Devaud, Jean-Marc

    2013-01-01

    Storage of information into long-term memory (LTM) usually requires at least two waves of transcription in many species. However, there is no clear evidence of this phenomenon in insects, which are influential models for memory studies. We measured retention in honeybees after injecting a transcription inhibitor at different times before and after…

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

    Science.gov (United States)

    Korz, Volker; Frey, Julietta U.

    2007-01-01

    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…

  16. Using electrophysiology to demonstrate that cuing affects long-term memory storage over the short term

    Science.gov (United States)

    Maxcey, Ashleigh M.; Fukuda, Keisuke; Song, Won S.; Woodman, Geoffrey F.

    2015-01-01

    As researchers who study working memory, we often assume that participants keep a representation of an object in working memory when we present a cue that indicates that object will be tested in a couple of seconds. This intuitively accounts for how well people can remember a cued object relative to their memory for that same object presented without a cue. However, it is possible that this superior memory does not purely reflect storage of the cued object in working memory. We tested the hypothesis that cued presented during a stream of objects, followed by a short retention interval and immediate memory test, change how information is handled by long-term memory. We tested this hypothesis using a family of frontal event-related potentials (ERPs) believed to reflect long-term memory storage. We found that these frontal indices of long-term memory were sensitive to the task relevance of objects signaled by auditory cues, even when objects repeat frequently such that proactive interference was high. Our findings indicate the problematic nature of assuming process purity in the study of working memory, and demonstrate how frequent stimulus repetitions fail to isolate the role of working memory mechanisms. PMID:25604772

  17. Memory Distortion in Alzheimer’s Disease: Deficient Monitoring of Short and Long-term Memory

    Science.gov (United States)

    MacDuffie, Katherine E.; Atkins, Alexandra S.; Flegal, Kristin E.; Clark, Christopher M.; Reuter-Lorenz, Patricia A.

    2012-01-01

    Objective This study measured distortions of memory during short-term memory (STM) and long-term memory (LTM) versions of a semantically-associated word list learning paradigm. Performance of patients with mild-to-moderate Alzheimer’s disease (AD; MMSE ? 16) was compared to performance of age-matched, healthy older adult participants. Method In a STM version of the Deese-Roediger-McDermott (DRM) task, participants viewed four-word lists and were prompted for recall after a brief interval. The LTM task tested recall memory for 12-word lists. Results Compared to the healthy group, the AD participants show greater impairment on the LTM task than on the STM task, although veridical recall is significantly reduced on both tasks. Furthermore, on both memory tasks: a) Participants with AD generate more nonsemantic intrusions than healthy older adult participants; b) semantic intrusion rate, when computed as a proportion of total recall, does not differ between groups. Notably, nonsemantic intrusions are consistently high for AD participants across both STM and LTM despite a marked difference in recall accuracy (65% and 23%, respectively). Conclusions STM impairment with some preserved semantic processing is evident in AD. The extent and variety of intrusions reported by AD participants indicates a breakdown in their ability to monitor and constrain their recall responses, even within seconds of initial learning. PMID:22746309

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

    OpenAIRE

    Dong, Zhifang; Han, Huili; Li, Hongjie; Bai, Yanrui; Wang, Wei; Tu, Man; Peng, Yan; Zhou, Limin; He, Wenting; Wu, Xiaobin; Tan, Tao; Liu, Mingjing; Xiaoyan WU; Zhou, Weihui; Jin, Wuyang

    2014-01-01

    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 th...

  19. Depletion of perineuronal nets enhances recognition memory and long-term depression in the perirhinal cortex.

    Science.gov (United States)

    Romberg, Carola; Yang, Sujeong; Melani, Riccardo; Andrews, Melissa R; Horner, Alexa E; Spillantini, Maria G; Bussey, Timothy J; Fawcett, James W; Pizzorusso, Tommaso; Saksida, Lisa M

    2013-04-17

    Perineuronal nets (PNNs) are extracellular matrix structures surrounding cortical neuronal cell bodies and proximal dendrites and are involved in the control of brain plasticity and the closure of critical periods. Expression of the link protein Crtl1/Hapln1 in neurons has recently been identified as the key event triggering the formation of PNNs. Here we show that the genetic attenuation of PNNs in adult brain Crtl1 knock-out mice enhances long-term object recognition memory and facilitates long-term depression in the perirhinal cortex, a neural correlate of object recognition memory. Identical prolongation of memory follows localized digestion of PNNs with chondroitinase ABC, an enzyme that degrades the chondroitin sulfate proteoglycan components of PNNs. The memory-enhancing effect of chondroitinase ABC treatment attenuated over time, suggesting that the regeneration of PNNs gradually restored control plasticity levels. Our findings indicate that PNNs regulate both memory and experience-driven synaptic plasticity in adulthood. PMID:23595763

  20. Metamemory ratings predict long-term changes in reactivated episodic memories

    Directory of Open Access Journals (Sweden)

    Amnon Yacoby

    2015-02-01

    Full Text Available Reactivation of long-term memory can render the memory item temporarily labile, offering an opportunity to modify it via behavioral or pharmacological intervention. Declarative memory reactivation is accompanied by a metamemory ability to subjectively assess the knowledge available concerning the target item (Feeling of knowing, FOK. We set out to examine whether FOK can predict the extent of change of long-term episodic memories by post-retrieval manipulations. To this end, participants watched a short movie and immediately thereafter tested on their memory for it. A day later, they were reminded of that movie, and either immediately or one day later, were presented with a second movie. The reminder phase consisted of memory cues to which participants were asked to judge their FOK regarding the original movie. The memory performance of participants to whom new information was presented immediately after reactivating the original episode corresponded to the degree of FOK ratings upon reactivation such that the lower their FOK, the less their memory declined. In contrast, no relation was found between FOK and memory strength for those who learned new information one day after the reminder phase. Our findings suggest that the subjective accessibility of reactivated memories may determine the extent to which new information might modify those memories.

  1. 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

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

    Directory of Open Access Journals (Sweden)

    Lee Yong-Seok

    2008-06-01

    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.

  3. A brief retraining regulates the persistence and lability of a long-term memory

    OpenAIRE

    Levitan, David; Twitto, Rachel; Levy, Roi; Lyons, Lisa C.; Susswein, Abraham J.

    2010-01-01

    An experience extending the persistence of a memory after training Aplysia californica with inedible food also allows a consolidated memory to become sensitive to consolidation blockers. Long-term (24 h) memory is initiated by 5 min of training and is dependent on protein synthesis during the first few hours after training. By contrast, a more persistent (48 h) memory is dependent on a longer training session and on a later round of protein synthesis. When presented 24 h after training, a 3-m...

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

    Science.gov (United States)

    Ries, Michele; Marks, William

    2006-01-01

    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

  5. Long-Term Memory for Music: Infants Remember Tempo and Timbre

    Science.gov (United States)

    Trainor, Laurel J.; Wu, Luann; Tsang, Christine D.

    2004-01-01

    We show that infants' long-term memory representations for melodies are not just reduced to the structural features of relative pitches and durations, but contain surface or performance tempo- and timbre-specific information. Using a head turn preference procedure, we found that after a one week exposure to an old English folk song, infants…

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

    Directory of Open Access Journals (Sweden)

    LynnHuestegge

    2014-07-01

    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.

  7. 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

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

    Science.gov (United States)

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

    2015-03-01

    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

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

    OpenAIRE

    Yoshida, Masatoshi; Naya, Yuji; Miyashita, Yasushi

    2003-01-01

    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,...

  10. Swimming exercise during pregnancy alleviates pregnancy-associated long-term memory impairment.

    Science.gov (United States)

    Kim, Kijeong; Chung, Eunhee; Kim, Chang-Ju; Lee, Sukho

    2012-08-20

    Regular exercise has been shown to be beneficial to the brain functions, but little is known about the effects of exercise during pregnancy on the long-term memory function of the mothers. The objective of this study was to determine the effects of swimming during pregnancy on long-term memory function in rats on postpartum day 8. We examined the impact of swimming exercise during pregnancy on cell proliferation and apoptotic neuronal cell death in the hippocampus of peripartum rats. The rats were divided into three groups: the control group, the pregnant non-swimming group, and the pregnant swimming group. We found that pregnancy impaired the long-term memory while swimming during pregnancy alleviated the memory impairment. Pregnancy decreased cell proliferation in the dentate gyrus of the hippocampus, but swimming exercise during pregnancy reversed pregnancy-associated decreased cell proliferation back to control level. There was no difference in apoptotic neuronal cell death in the hippocampus among groups. Our results suggest that swimming during pregnancy alleviates pregnancy-associated decrease in memory function of mothers through an increase in cell proliferation in the hippocampus. PMID:22705471

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

    International Nuclear Information System (INIS)

    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 deg. 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

  12. Similarities and Differences Between Working Memory and Long-Term Memory: Evidence From the Levels-of-Processing Span Task

    OpenAIRE

    Rose, Nathan S; Myerson, Joel; Roediger, Henry L.; Hale, Sandra

    2010-01-01

    Two experiments compared the effects of depth of processing on working memory (WM) and long-term memory (LTM) using a levels-of-processing (LOP) span task, a newly developed WM span procedure that involves processing to-be-remembered words based on their visual, phonological, or semantic characteristics. Depth of processing had minimal effect on WM tests, yet subsequent memory for the same items on delayed tests showed the typical benefits of semantic processing. Although the difference in LO...

  13. High-precision visual long-term memory in children with high-functioning autism.

    Science.gov (United States)

    Jiang, Yuhong V; Palm, Bryce E; DeBolt, Michaela C; Goh, Yi Shuen

    2015-05-01

    Domain-general theories of autism rest on evidence that the disorder impacts not only social communication skills but also nonsocial functions such as memory. Yet recognition memory deficits have been inconsistently documented, especially for stimuli other than faces and sentences. Here we tested school-age children with high-functioning autism (ASD) and IQ, and age-matched comparison children on a visual long-term memory task involving more than 100 photographs of objects, faces, cats, houses, and abstract stimuli. Children viewed each photograph for 2 s. After a 10-min filled delay, we assessed recognition memory for object category as well as for specific exemplars. Data supported the presence of a high-capacity and high-precision visual memory in children with ASD. Both category memory and exemplar memory accuracies were above 90% for categories for which a single exemplar had been encoded. When more exemplars per category were encoded, category memory improved, but exemplar memory declined. An exception was face memory, which remained highly accurate even after many faces had been encoded. Our study provided no evidence that visual memory in general, and face memory in particular, is impaired in children with ASD. PMID:25436998

  14. Cues, context, and long-term memory: the role of the retrosplenial cortex in spatial cognition

    Directory of Open Access Journals (Sweden)

    Adam M P Miller

    2014-08-01

    Full Text Available Spatial navigation requires representations of landmarks and other navigation cues. The retrosplenial cortex (RSC is anatomically positioned between limbic areas important for memory formation, such as the hippocampus and the anterior thalamus, and cortical regions along the dorsal stream known to contribute importantly to long-term spatial representation, such as the posterior parietal cortex. Damage to the RSC severely impairs allocentric representations of the environment, including the ability to derive navigational information from landmarks. The specific deficits seen in tests of human and rodent navigation suggest that the RSC supports allocentric representation by processing the stable features of the environment and the spatial relationships among them. In addition to spatial cognition, the RSC plays a key role in contextual and episodic memory. The RSC also contributes importantly to the acquisition and consolidation of long-term spatial and contextual memory through its interactions with the hippocampus. Within this framework, the RSC plays a dual role as part of the feedforward network providing sensory and mnemonic input to the hippocampus and as a target of the hippocampal-dependent systems consolidation of long-term memory.

  15. 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)

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

    2006-01-01

    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…

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

    Directory of Open Access Journals (Sweden)

    Nasrin Hosseini

    2014-01-01

    Full Text Available 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.

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

    OpenAIRE

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

    2012-01-01

    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...

  18. Protein phosphatase 1 regulates the histone code for long-term memory

    OpenAIRE

    Koshibu, Kyoko; Gräff, Johannes; Beullens, Monique; Heitz, Fabrice D.; Berchtold, Dominik; Russig, Holger; Farinelli, Mélissa; Bollen, Mathieu; Mansuy, Isabelle M.

    2009-01-01

    Chromatin remodeling through histone posttranslational modifications (PTMs) and DNA methylation has recently been implicated in cognitive functions, but the mechanisms involved in such epigenetic regulation remain poorly understood. Here, we show that protein phosphatase 1 (PP1) is a critical regulator of chromatin remodeling in the mammalian brain that controls histone PTMs and gene transcription associated with long-term memory. Our data show that PP1 is present at the chromatin in brain ce...

  19. Integrin Dynamics Produce a Delayed Stage of Long-Term Potentiation and Memory Consolidation

    OpenAIRE

    Babayan, Alex H.; Kramár, Enikö A.; Barrett, Ruth M.; Jafari, Matiar; Häettig, Jakob; Chen, Lulu Y; Rex, Christopher S.; Lauterborn, Julie C.; Wood, Marcelo A.; Gall, Christine M.; Lynch, Gary

    2012-01-01

    Memory consolidation theory posits that newly acquired information passes through a series of stabilization steps before being firmly encoded. We report here that in rat and mouse, hippocampus cell adhesion receptors belonging to the ?1-integrin family exhibit dynamic properties in adult synapses and that these contribute importantly to a previously unidentified stage of consolidation. Quantitative dual immunofluorescence microscopy showed that induction of long-term potentiation (LTP) by the...

  20. Extreme event return times in long-term memory processes near 1/f

    OpenAIRE

    Sienz, F.; Fraedrich, K.; Blender, R.

    2008-01-01

    The distribution of extreme event return times and their correlations are analyzed in observed and simulated long-term memory (LTM) time series with 1/f power spectra. The analysis is based on tropical temperature and mixing ratio (specific humidity) time series from TOGA COARE with 1 min resolution and an approximate 1/f power spectrum. Extreme events are determined by Peak-Over-Threshold (POT) crossing. The Weibull distribution represents a reasonable fit to the return time distributions wh...

  1. Integrin dynamics produce a delayed stage of long-term potentiation and memory consolidation.

    Science.gov (United States)

    Babayan, Alex H; Kramár, Enikö A; Barrett, Ruth M; Jafari, Matiar; Häettig, Jakob; Chen, Lulu Y; Rex, Christopher S; Lauterborn, Julie C; Wood, Marcelo A; Gall, Christine M; Lynch, Gary

    2012-09-12

    Memory consolidation theory posits that newly acquired information passes through a series of stabilization steps before being firmly encoded. We report here that in rat and mouse, hippocampus cell adhesion receptors belonging to the ?1-integrin family exhibit dynamic properties in adult synapses and that these contribute importantly to a previously unidentified stage of consolidation. Quantitative dual immunofluorescence microscopy showed that induction of long-term potentiation (LTP) by theta burst stimulation (TBS) activates ?1 integrins, and integrin-signaling kinases, at spine synapses in adult hippocampal slices. Neutralizing antisera selective for ?1 integrins blocked these effects. TBS-induced integrin activation was brief (consolidation for both LTP and memory. PMID:22973009

  2. Long-term memory, forgetting, and deferred imitation in 12-month-old infants

    OpenAIRE

    Klein, Pamela J.; Meltzoff, Andrew N.

    1999-01-01

    Long-term recall memory, as indexed by deferred imitation, was assessed in 12-month-old infants. Independent groups of infants were tested after retention intervals of 3 min, 1 week and 4 weeks. Deferred imitation was assessed using the ‘observation-only’ procedure in which infants were not allowed motor practice on the tasks before the delay was imposed. Thus, the memory could not have been based on re-accessing a motor habit, because none was formed in the first place. After the delay, memo...

  3. Neuronal correlate of visual associative long-term memory in the primate temporal cortex

    Science.gov (United States)

    Miyashita, Yasushi

    1988-10-01

    In human long-term memory, ideas and concepts become associated in the learning process1. No neuronal correlate for this cognitive function has so far been described, except that memory traces are thought to be localized in the cerebral cortex; the temporal lobe has been assigned as the site for visual experience because electric stimulation of this area results in imagery recall,2 and lesions produce deficits in visual recognition of objects3-9. We previously reported that in the anterior ventral temporal cortex of monkeys, individual neurons have a sustained activity that is highly selective for a few of the 100 coloured fractal patterns used in a visual working-memory task10. Here I report the development of this selectivity through repeated trials involving the working memory. The few patterns for which a neuron was conjointly selective were frequently related to each other through stimulus-stimulus association imposed during training. The results indicate that the selectivity acquired by these cells represents a neuronal correlate of the associative long-term memory of pictures.

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

    OpenAIRE

    Pisoni, David B.

    1993-01-01

    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 analysis. ...

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

    Directory of Open Access Journals (Sweden)

    A. Rashidy-Pour

    2006-11-01

    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.

  6. Extreme event return times in long-term memory processes near 1/f

    Directory of Open Access Journals (Sweden)

    F. Sienz

    2008-07-01

    Full Text Available The distribution of extreme event return times and their correlations are analyzed in observed and simulated long-term memory (LTM time series with 1/f power spectra. The analysis is based on tropical temperature and mixing ratio (specific humidity time series from TOGA COARE with 1 min resolution and an approximate 1/f power spectrum. Extreme events are determined by Peak-Over-Threshold (POT crossing. The Weibull distribution represents a reasonable fit to the return time distributions while the power-law predicted by the stretched exponential for 1/f deviates considerably. For a comparison and an analysis of the return time predictability, a very long simulated time series with an approximate 1/f spectrum is produced by a fractionally differenced (FD process. This simulated data confirms the Weibull distribution (a power law can be excluded. The return time sequences show distinctly weaker long-term correlations than the original time series (correlation exponent ??0.56.

  7. Improving potato drought tolerance through the induction of long-term water stress memory.

    Science.gov (United States)

    Ramírez, D A; Rolando, J L; Yactayo, W; Monneveux, P; Mares, V; Quiroz, R

    2015-09-01

    Knowledge of drought tolerance in potato is limited and very little is known about stress memory in this crop. In the present study, long-term stress memory was tested on tuber yield and drought tolerance related traits in three potato varieties (Unica, Désirée and Sarnav) with contrasted yields under water restriction. Seed tubers produced by plants grown under non-restricted (non-primed tubers) and restricted (primed tubers) water conditions were sown and exposed to similar watering treatments. Tuber yield and leaf greenness of plants from primed and non-primed seeds as well as tuber carbon isotope discrimination (?(13)C) and antioxidant activity (AA) responses to watering treatments were compared. Higher tuber yield, both under non-restricted and restricted water regimes, was produced by primed Sarnav plants. The decrease of tuber yield and ?(13)C with water restriction was lower in primed Unica plants. Long-term stress memory consequently appears to be highly genotype-dependent in potato. Its expression in plants originated from primed tubers and facing water restriction seems to be positively associated to the degree of inherent capability of the cultivar to yield under water restriction. However, other effects of priming appear to be genotype-independent as priming enhanced the tuber AA in response to water restriction in the three varieties. PMID:26259171

  8. Measuring capital market efficiency: long-term memory, fractal dimension and approximate entropy

    Science.gov (United States)

    Kristoufek, Ladislav; Vosvrda, Miloslav

    2014-07-01

    We utilize long-term memory, fractal dimension and approximate entropy as input variables for the Efficiency Index [L. Kristoufek, M. Vosvrda, Physica A 392, 184 (2013)]. This way, we are able to comment on stock market efficiency after controlling for different types of inefficiencies. Applying the methodology on 38 stock market indices across the world, we find that the most efficient markets are situated in the Eurozone (the Netherlands, France and Germany) and the least efficient ones in the Latin America (Venezuela and Chile).

  9. Measuring capital market efficiency: Long-term memory, fractal dimension and approximate entropy.

    Czech Academy of Sciences Publication Activity Database

    Krištoufek, Ladislav; Vošvrda, Miloslav

    Jihlava : College of Polytechnics Jihlava, 2013 - (Vojackova, H.), s. 470-475 ISBN 978-80-87035-76-4. [International Conference on Mathematical Methods in Economics 2013 /31./. Jihlava (CZ), 11.09.2013-13.09.2013] R&D Projects: GA ?R GA402/09/0965 Grant ostatní: MŠk(CZ) SVV265504 Institutional support: RVO:67985556 Keywords : capital market efficiency * long-range dependence * fractal dimension * approximate entropy Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2013/E/kristoufek-measuring capital market efficienci long-term memory fractal dimension and approximate entropy .pdf

  10. Persistence of Long-Term Memory in Vitrified and Revived Caenorhabditis elegans.

    Science.gov (United States)

    Vita-More, Natasha; Barranco, Daniel

    2015-10-01

    Can memory be retained after cryopreservation? Our research has attempted to answer this long-standing question by using the nematode worm Caenorhabditis elegans, a well-known model organism for biological research that has generated revolutionary findings but has not been tested for memory retention after cryopreservation. Our study's goal was to test C. elegans' memory recall after vitrification and reviving. Using a method of sensory imprinting in the young C. elegans, we establish that learning acquired through olfactory cues shapes the animal's behavior and the learning is retained at the adult stage after vitrification. Our research method included olfactory imprinting with the chemical benzaldehyde (C6H5CHO) for phase-sense olfactory imprinting at the L1 stage, the fast-cooling SafeSpeed method for vitrification at the L2 stage, reviving, and a chemotaxis assay for testing memory retention of learning at the adult stage. Our results in testing memory retention after cryopreservation show that the mechanisms that regulate the odorant imprinting (a form of long-term memory) in C. elegans have not been modified by the process of vitrification or by slow freezing. PMID:25867710

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

    Science.gov (United States)

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

    2006-03-01

    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 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. PMID:16501817

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

    OpenAIRE

    Potkin, Katya Trudeau; Bunney, William E.

    2012-01-01

    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...

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

    Scientific Electronic Library Online (English)

    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

    Full Text Available 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.

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

    Science.gov (United States)

    Schweppe, Judith; Rummer, Ralf

    2014-01-01

    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…

  15. Effects of Pre-Encoding Stress on Brain Correlates Associated with the Long-Term Memory for Emotional Scenes

    OpenAIRE

    Wirkner, Janine; Weymar, Mathias; Löw, Andreas; Hamm, Alfons O.

    2013-01-01

    Recent animal and human research indicates that stress around the time of encoding enhances long-term memory for emotionally arousing events but neural evidence remains unclear. In the present study we used the ERP old/new effect to investigate brain dynamics underlying the long-term effects of acute pre-encoding stress on memory for emotional and neutral scenes. Participants were exposed either to the Socially Evaluated Cold Pressure Test (SECPT) or a warm water control procedure before view...

  16. Exchange Protein Activated by cAMP Enhances Long-Term Memory Formation Independent of Protein Kinase A

    Science.gov (United States)

    Ma, Nan; Abel, Ted; Hernandez, Pepe J.

    2009-01-01

    It is well established that cAMP signaling within neurons plays a major role in the formation of long-term memories--signaling thought to proceed through protein kinase A (PKA). However, here we show that exchange protein activated by cAMP (Epac) is able to enhance the formation of long-term memory in the hippocampus and appears to do so…

  17. Valence and the development of immediate and long-term false memory illusions.

    Science.gov (United States)

    Howe, Mark L; Candel, Ingrid; Otgaar, Henry; Malone, Catherine; Wimmer, Marina C

    2010-01-01

    Across five experiments we examined the role of valence in children's and adults' true and false memories. Using the Deese/Roediger-McDermott paradigm and either neutral or negative-emotional lists, both adults' (Experiment 1) and children's (Experiment 2) true recall and recognition was better for neutral than negative items, and although false recall was also higher for neutral items, false recognition was higher for negative items. The last three experiments examined adults' (Experiment 3) and children's (Experiments 4 and 5) 1-week long-term recognition of neutral and negative-emotional information. The results replicated the immediate recall and recognition findings from the first two experiments. More important, these experiments showed that although true recognition decreased over the 1-week interval, false recognition of neutral items remained unchanged whereas false recognition of negative-emotional items increased. These findings are discussed in terms of theories of emotion and memory as well as their forensic implications. PMID:20391177

  18. The coding theorem for a class of quantum channels with long-term memory

    International Nuclear Information System (INIS)

    In this paper, we consider the transmission of classical information through a class of quantum channels with long-term memory, which are convex combinations of memoryless channels. Hence, the memory of such channels can be considered to be given by a Markov chain which is aperiodic but not irreducible. We prove the coding theorem and weak converse for this class of channels. The main techniques that we employ are a quantum version of Feinstein's fundamental lemma (Feinstein A 1954 IRE Trans. PGIT 4 2-22, Khinchin A I 1957 Mathematical Foundations of Information Theory: II. On the Fundamental Theorems of Information Theory (New York: Dover) chapter IV) and a generalization of Helstrom's theorem (Helstrom C W 1976 Quantum detection and estimation theory Mathematics in Science and Engineering vol 123 (London: Academic))

  19. From Drosophila development to adult: clues to Notch function in long-term memory

    Directory of Open Access Journals (Sweden)

    Cedric S Wesley

    2013-11-01

    Full Text Available Notch is a cell surface receptor that is well known to mediate inter-cellular communication during animal development. Data in the field indicate that it is also involved in the formation of long-term memory (LTM in the fully developed adults and in memory loss upon neurodegeneration. Our studies in the model organism Drosophila reveal that a non-canonical Notch-Protein Kinase C (PKC activity that plays critical roles in embryonic development also regulates Cyclic-AMP Response Element Binding protein (CREB during LTM formation in adults. Here we present a perspective on how the various known features of Notch function relate to LTM formation and how they might interface with elements of Wingless/Wnt signaling in this process.

  20. Intrinsic Memorability Predicts Short- and Long-Term Memory of Static and Dynamic Faces.

    Science.gov (United States)

    Zhao, Mintao; Bülthoff, Isabelle

    2015-09-01

    Does a face itself determine how well it will be recognized? Unlike many previous studies that have linked face recognition performance to individuals' face processing ability (e.g., holistic processing), the present study investigated whether recognition of natural faces can be predicted by the faces themselves. Specifically, we examined whether short- and long-term recognition memory of both dynamic and static faces can be predicted according to face-based properties. Participants memorized either dynamic (Experiment 1) or static (Experiment 2) natural faces, and recognized them with both short- and long-term retention intervals (three minutes vs. seven days). We found that the intrinsic memorability of individual faces (i.e., the rate of correct recognition across a group of participants) consistently predicted an independent group of participants' performance in recognizing the same faces, for both static and dynamic faces and for both short- and long-term face recognition memory. This result indicates that intrinsic memorability of faces is bound to face identity rather than image properties. Moreover, we also asked participants to judge subjective memorability of faces they just learned, and to judge whether they were able to recognize the faces in late test. The result shows that participants can extract intrinsic face memorability at encoding. Together, these results provide compelling evidence for the hypothesis that intrinsic face memorability predicts natural face recognition, highlighting that face recognition performance is not only a function of individuals' face processing ability, but also determined by intrinsic properties of faces. Meeting abstract presented at VSS 2015. PMID:26326386

  1. Long-term memory in the Irish market (ISEQ): evidence from wavelet analysis

    CERN Document Server

    Sharkasi, A; Crane, M; Sharkasi, Adel; Ruskin, Heather J.; Crane, Martin

    2006-01-01

    Researchers have used many different methods to detect the possibility of long-term dependence (long memory) in stock market returns, but evidence is in general mixed. In this paper, three different tests, (namely Rescaled Range (R/S), its modified form, and the semi-parametric method (GPH)), in addition to a new approach using the discrete wavelet transform, (DWT), have been applied to the daily returns of five Irish Stock Exchange (ISEQ) indices. These methods have also been applied to the volatility measures (namely absolute and squared returns). The aim is to investigate the existence of long-term memory properties. The indices are Overall, Financial, General, Small Cap and ITEQ and the results of these approaches show that there is no evidence of long-range dependence in the returns themselves, while there is strong evidence for such dependence in the squared and absolute returns. Moreover, the discrete wavelet transform (DWT) provides additional insight on the series breakdown. In particular, in compari...

  2. Helping students succeed by helping them improve their long-term memory

    Science.gov (United States)

    Zettili, Nouredine; Boukahil, A.

    2005-04-01

    In this work, we focus on one of the most useful techniques of efficient study habits: How to improve long-term memory. We show that if a student carries a number of recalling sessions of the material studied and if he/she carries them at specific times, the student will be able to retain this material for a long time and hence be prepared for the exams. We argue that a student who conscientiously uses the proper techniques of efficient study habits will be able to achieve higher results than the student who does not. Moreover, a student equipped with the proper study skills will spend much less time to learn a subject than a student who has no effective study habits. After providing a summary of the most essential personal skills needed to be a successful student--concentration skills, how to take notes in class, how to prepare for and take exams---we give an extensive presentation on the techniques of improving long-term memory.

  3. Unforgettable film music: The role of emotion in episodic long-term memory for music

    Directory of Open Access Journals (Sweden)

    Altenmüller Eckart O

    2008-05-01

    Full Text Available Abstract Background Specific pieces of music can elicit strong emotions in listeners and, possibly in connection with these emotions, can be remembered even years later. However, episodic memory for emotional music compared with less emotional music has not yet been examined. We investigated whether emotional music is remembered better than less emotional music. Also, we examined the influence of musical structure on memory performance. Results Recognition of 40 musical excerpts was investigated as a function of arousal, valence, and emotional intensity ratings of the music. In the first session the participants judged valence and arousal of the musical pieces. One week later, participants listened to the 40 old and 40 new musical excerpts randomly interspersed and were asked to make an old/new decision as well as to indicate arousal and valence of the pieces. Musical pieces that were rated as very positive were recognized significantly better. Conclusion Musical excerpts rated as very positive are remembered better. Valence seems to be an important modulator of episodic long-term memory for music. Evidently, strong emotions related to the musical experience facilitate memory formation and retrieval.

  4. Great Apes Make Anticipatory Looks Based on Long-Term Memory of Single Events.

    Science.gov (United States)

    Kano, Fumihiro; Hirata, Satoshi

    2015-10-01

    Everyday life poses a continuous challenge for individuals to encode ongoing events, retrieve past events, and predict impending events [1-4]. Attention and eye movements reflect such online cognitive and memory processes [5, 6], especially through "anticipatory looks" [7-10]. Previous studies have demonstrated the ability of nonhuman animals to retrieve detailed information about single events that happened in the distant past [11-20]. However, no study has tested whether nonhuman animals employ online memory processes, in which they encode ongoing movie-like events into long-term storage during single viewing experiences. Here, we developed a novel eye-tracking task to examine great apes' anticipatory looks to the events that they had encountered one time 24 hr earlier. Half-minute movie clips depicted novel and potentially alarming situations to the participant apes (six bonobos, six chimpanzees). In the experiment 1 clip, an aggressive ape-like character came out from one of two identical doors. While viewing the same movie again, apes anticipatorily looked at the door where the character would show up. In the experiment 2 clip, the human actor grabbed one of two objects and attacked the character with it. While viewing the same movie again but with object-location switched, apes anticipatorily looked at the object that the human would use, rather than the former location of the object. Our results thus show that great apes, just by watching the events once, encoded particular information (location and content) into long-term memory and later retrieved that information at a particular time in anticipation of the impending events. PMID:26387711

  5. Visual long term memory is spatially specific, but only after a brief consolidation period.

    Science.gov (United States)

    Hong, Yoolim; Leber, Andrew

    2015-09-01

    For successful commerce with the world, it is essential that we remember objects that we encounter within the proper contexts. Consistent with this, visual long-term memory is known to be context dependent. However, the way in which these context dependent memories manifest has been relatively unexplored. Here, we measured the degree to which visual object memory is tied to spatial location. We manipulated the retention interval to explore how spatially specific memories emerged over time. During an initial encoding phase, we presented two placeholders on the screen (one on the left, one on the right), and we presented a series of 200 face stimuli. To associate each face stimulus with specific spatial context, half of them appeared inside the left placeholder and the other half appeared inside the right placeholder. Participants were instructed to discriminate each face's gender, regardless of its location. Subsequently, participants began the recognition phase. Critically, for one group of participants (No Retention Group), the recognition phase began immediately after encoding was finished, while for the other group (Retention Group), the recognition phase began after a 15 min retention interval in which a visual search task was performed. During the recognition phase, we presented one previously viewed (old) face and one novel face on each of 200 trials. Participants had to discriminate the side of the display containing the old face. To manipulate context dependency, we presented half of the faces inside the same placeholder as during encoding ("matching" condition) and the remaining faces inside the other placeholder ("nonmatching" condition). Results showed that the Retention group's recognition memory was significantly better in the matching condition than the nonmatching condition, while the No-Retention group's performance was equivalent in the two conditions. These results implicate a key role of consolidation in the genesis of context-specific visual memory. Meeting abstract presented at VSS 2015. PMID:26325780

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

    Directory of Open Access Journals (Sweden)

    F.H. Santos

    2006-03-01

    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.

  7. Protein degradation and protein synthesis in long-term memory formation

    Directory of Open Access Journals (Sweden)

    Timothy J Jarome

    2014-06-01

    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.

  8. Differentially expressed genes linked to natural variation in long-term memory formation in Cotesia parasitic wasps

    Science.gov (United States)

    van Vugt, Joke J. F. A.; Hoedjes, Katja M.; van de Geest, Henri C.; Schijlen, Elio W. G. M.; Vet, Louise E. M.; Smid, Hans M.

    2015-01-01

    Even though learning and memory are universal traits in the Animal Kingdom, closely related species reveal substantial variation in learning rate and memory dynamics. To determine the genetic background of this natural variation, we studied two congeneric parasitic wasp species, Cotesia glomerata and C. rubecula, which lay their eggs in caterpillars of the large and small cabbage white butterfly. A successful egg laying event serves as an unconditioned stimulus (US) in a classical conditioning paradigm, where plant odors become associated with the encounter of a suitable host caterpillar. Depending on the host species, the number of conditioning trials and the parasitic wasp species, three different types of transcription-dependent long-term memory (LTM) and one type of transcription-independent, anesthesia-resistant memory (ARM) can be distinguished. To identify transcripts underlying these differences in memory formation, we isolated mRNA from parasitic wasp heads at three different time points between induction and consolidation of each of the four memory types, and for each sample three biological replicates, where after strand-specific paired-end 100 bp deep sequencing. Transcriptomes were assembled de novo and differential expression was determined for each memory type and time point after conditioning, compared to unconditioned wasps. Most differentially expressed (DE) genes and antisense transcripts were only DE in one of the LTM types. Among the DE genes that were DE in two or more LTM types, were many protein kinases and phosphatases, small GTPases, receptors and ion channels. Some genes were DE in opposing directions between any of the LTM memory types and ARM, suggesting that ARM in Cotesia requires the transcription of genes inhibiting LTM or vice versa. We discuss our findings in the context of neuronal functioning, including RNA splicing and transport, epigenetic regulation, neurotransmitter/peptide synthesis and antisense transcription. In conclusion, these brain transcriptomes provide candidate genes that may be involved in the observed natural variation in LTM in closely related Cotesia parasitic wasp species.

  9. Combining Stressors That Individually Impede Long-Term Memory Blocks All Memory Processes

    OpenAIRE

    Dalesman, Sarah; Sunada, Hiroshi; Teskey, Morgan Lee; Lukowiak, Ken

    2013-01-01

    The effects of stress on memory are typically assessed individually; however, in reality different stressors are often experienced simultaneously. Here we determined the effect that two environmentally relevant stressors, crowding and low calcium availability, have on memory and neural activity following operant conditioning of aerial respiration in the pond snail, Lymnaea stagnalis. We measured aerial breathing behaviour and activity of a neuron necessary for memory formation, right pedal do...

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

    Science.gov (United States)

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

    2006-01-01

    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…

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

    Directory of Open Access Journals (Sweden)

    Vardan G. Arutyunyan

    2013-01-01

    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.

  12. Stress and glucocorticoid receptor-dependent mechanisms in long-term memory: from adaptive responses to psychopathologies

    OpenAIRE

    Finsterwald, Charles; Alberini, Cristina M.

    2013-01-01

    A proper response against stressors is critical for survival. In mammals, the stress response is primarily mediated by secretion of glucocorticoids via the hypothalamic-pituitaryadrenocortical (HPA) axis and release of catecholamines through adrenergic neurotransmission. Activation of these pathways results in a quick physical response to the stress and, in adaptive conditions, mediates long-term changes in the brain that lead to the formation of long-term memories of the experience. These lo...

  13. Post-learning stress enhances long-term memory and differentially influences memory in females depending on menstrual stage.

    Science.gov (United States)

    Zoladz, Phillip R; Peters, David M; Cadle, Chelsea E; Kalchik, Andrea E; Aufdenkampe, Rachael L; Dailey, Alison M; Brown, Callie M; Scharf, Amanda R; Earley, McKenna B; Knippen, Courtney L; Rorabaugh, Boyd R

    2015-09-01

    Most work has shown that post-learning stress enhances long-term memory; however, there have been recent inconsistencies in this literature. The purpose of the present study was to examine further the effects of post-learning stress on long-term memory and to explore any sex differences that may exist. Male and female participants learned a list of 42 words that varied in emotional valence and arousal level. Following encoding, participants completed a free recall assessment and then submerged their hand into a bath of ice cold (stress) or lukewarm (no stress) water for 3 min. The next day, participants were given free recall and recognition tests. Stressed participants recalled more words than non-stressed participants 24h after learning. Stress also enhanced female participants' recall of arousing words when they were in the follicular, but not luteal, phase. These findings replicate previous work examining post-learning stress effects on memory and implicate the involvement of sex-related hormones in such effects. PMID:26233730

  14. Stress Management Interventions and Predictors of Long-term Health : Prospectively Controlled Studies on Long-term Pain Patients and a Healthy Sample from IT- and Media Companies

    OpenAIRE

    Hasson, Dan

    2005-01-01

    This thesis reports on the effects of stress management on long-term pain patients and on a healthy sample from IT and media companies; two groups that are commonly exposed to high stress levels. Even if there are important differences between these two groups, there are similarities such as the necessity for effective stress management. Stress-related and musculoskeletal disorders are major public health issues in most industrialized countries and are expected to become increasingly common d...

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

    OpenAIRE

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

    2013-01-01

    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. ...

  16. Inverse temporal contributions of the dorsal hippocampus and medial prefrontal cortex to the expression of long-term fear memories

    OpenAIRE

    Quinn, Jennifer J.; Ma, Quang D.; Tinsley, Matthew R.; Koch, Christof; Fanselow, Michael S

    2008-01-01

    Retrograde amnesia following disruptions of hippocampal function is often temporally graded, with recent memories being more impaired. Evidence supports the existence of one or more neocortical long-term memory storage/retrieval site(s). Neurotoxic lesions of the medial prefrontal cortex (mPFC) or the dorsal hippocampus (DH) were made 1 day or 200 days following trace fear conditioning. Recently encoded trace fear memories were most disrupted by DH lesions, while remotely encoded trace and co...

  17. Word-frequency effects in long-term semantic priming and false memory.

    Science.gov (United States)

    Sherman, Susan M; Jordan, Timothy R

    2011-08-01

    Several studies have used the lexical decision task (LDT) with the Deese-Roediger-McDermott (DRM) false-memory paradigm to investigate whether long-term semantic priming (LTSP) occurs following presentation of lists of items (e.g., bed, dream, snore) for related non-presented lure words (e.g., sleep). However, results have been mixed, with some studies observing priming, whilst others have not. The present study had four goals: (i) to investigate the existence of LTSP in the LDT; (ii) to investigate effects of LTSP on standard effects of word frequency on LDT performance; (iii) to investigate the effect, if any, of word frequency on true and false recall; and (iv) to compare LDT performance with performance on a subsequent free-recall task. The findings showed (i) a significant effect of LTSP on LDT performance; (ii) no effect of LTSP on standard effects of word frequency on LDT performance; (iii) no effect of word frequency on either true or false free recall; and (iv) a significant relationship between LDT and free-recall performance. Implications of these findings for understanding LTSP and false memories are discussed. PMID:21752006

  18. Effects of long-term electromagnetic field exposure on spatial learning and memory in rats.

    Science.gov (United States)

    Hao, Dongmei; Yang, Lei; Chen, Su; Tong, Jun; Tian, Yonghao; Su, Benhang; Wu, Shuicai; Zeng, Yanjun

    2013-02-01

    With the development of communications industry, mobile phone plays an important role in daily life. Whether or not the electromagnetic radiation emitted by mobile phone causes any adverse effects on brain function has become of a great concern. This paper investigated the effect of electromagnetic field on spatial learning and memory in rats. 32 trained Wistar rats were divided into two groups: exposure group and control group. The exposure group was exposed to 916 MHz, 10w/m2 mobile phone electromagnetic field (EMF) 6 h a day, 5 days a week, 10 weeks. The completion time, number of total errors and the neuron discharge signals were recorded while the rats were searching for food in an eight-arm radial maze at every weekend. The neuron signals of one exposed rat and one control rat in the maze were obtained by the implanted microelectrode arrays in their hippocampal regions. It can be seen that during the weeks 4-5 of the experiment, the average completion time and error rate of the exposure group were longer and larger than that of control group (p influence learning and memory in rats to some extent in a period during exposure, and the rats can adapt to long-term EMF exposure. PMID:22362331

  19. Expertise in cognitive psychology: testing the hypothesis of long-term working memory in a study of soccer players.

    Science.gov (United States)

    Postal, Virginie

    2004-10-01

    This experiment compared several theories of expertise and exceptional performances in cognitive psychology. One current conception assumes that experts in a specific domain have developed a long-term working memory, which accounts for the difference in memory performance between experts and novices. The principal characteristics of this memory are the speed with which processes of storage and retrieval function and the existence of retrieval structures that allow a temporary activation of the knowledge store in long-term memory. Other authors such as Vicente and Wang argue this notion does not account for memory performance that is not intrinsic to the domain of expertise. We attempt to clarify the two viewpoints and to focus on this debate by testing the hypothesis of long-term working memory using soccer as the domain of expertise and by comparing the cognitive performance of participants who have different expertise (novices, supporters, players, and coaches). 35 male participants were administered a new version of the Reading Span test to assess their long-term working memory according to two conditions. In the first condition (structured condition), the last word of each sentence was related to the soccer domain, and these words were related to each other in such a manner that they represented a part of the game. In the second condition (unstructured condition), the last word of each sentence was related to soccer but these words did not represent part of the game. Analysis showed that the sentence span increased as a function of expertise for the structured condition but not for the unstructured condition. The results were interpreted in the framework of the constraint attunement hypothesis proposed by Vicente in 1992 and the long-term working memory hypothesis proposed by Ericsson and Kintsch in 1995. PMID:15560327

  20. Rapamycin restores BDNF-LTP and the persistence of long-term memory in a model of Down's syndrome.

    Science.gov (United States)

    Andrade-Talavera, Yuniesky; Benito, Itziar; Casañas, Juan José; Rodríguez-Moreno, Antonio; Montesinos, María Luz

    2015-10-01

    Down's syndrome (DS) is the most prevalent genetic intellectual disability. Memory deficits significantly contribute to the cognitive dysfunction in DS. Previously, we discovered that mTOR-dependent local translation, a pivotal process for some forms of synaptic plasticity, is deregulated in a DS mouse model. Here, we report that these mice exhibit deficits in both synaptic plasticity (i.e., BDNF-long term potentiation) and the persistence of spatial long-term memory. Interestingly, these deficits were fully reversible using rapamycin, a Food and Drug Administration-approved specific mTOR inhibitor; therefore, rapamycin may be a novel pharmacotherapy to improve cognition in DS. PMID:26388397

  1. Inert gas narcosis disrupts encoding but not retrieval of long term memory.

    Science.gov (United States)

    Hobbs, Malcolm; Kneller, Wendy

    2015-05-15

    Exposure to increased ambient pressure causes inert gas narcosis of which one symptom is long-term memory (LTM) impairment. Narcosis is posited to impair LTM by disrupting information encoding, retrieval (self-guided search), or both. The effect of narcosis on the encoding and retrieval of LTM was investigated by testing the effect of learning-recall pressure and levels of processing (LoP) on the free-recall of word lists in divers underwater. All participants (n=60) took part in four conditions in which words were learnt and then recalled at either low pressure (1.4-1.9atm/4-9msw) or high pressure (4.4-5.0atm/34-40msw), as manipulated by changes in depth underwater: low-low (LL), low-high(LH), high-high (HH), and high-low (HL). In addition, participants were assigned to either a deep or shallow processing condition, using LoP methodology. Free-recall memory ability was significantly impaired only when words were initially learned at high pressure (HH & HL conditions). When words were learned at low pressure and then recalled at low pressure (LL condition) or high pressure (LH condition) free-recall was not impaired. Although numerically superior in several conditions, deeper processing failed to significantly improve free-recall ability in any of the learning-recall conditions. This pattern of results support the hypothesis that narcosis disrupts encoding of information into LTM, while retrieval appears to be unaffected. These findings are discussed in relation to similar effects reported by some memory impairing drugs and the practical implications for workers in pressurised environments. PMID:25725120

  2. Visual Metamemory: Metacognitive Control and Monitoring of Long-Term Visual Memory for Objects and People.

    Science.gov (United States)

    New, Joshua; LoSchiavo, Caleb; Son, Lisa

    2015-09-01

    People have a remarkable long-term memory for scenes and objects - recognizing thousands of images from only a few moments of study each. We asked whether this visual memory capacity is associated with any metacognitive functions: What sense do viewers have of their abilities to encode - and subsequently access - such large numbers of stimuli? We tested whether allowing participants to control the time studying each image (self-paced) would - relative to fixed display durations (computer-paced) - increase their performance in a 2AFC old-new recognition test. We also tested whether participants had some metacognitive knowledge about their visual memory traces, through their 'bets' on having successfully recognized each item. In Experiment 1, when participants were allowed an average of two seconds of study for each item, recognition performance was significantly higher for self-paced than computer-paced study items. In the self-paced condition, the amount of time studying items was not only a significant predictor of their successful recognition but also of viewers' metacognitive awareness (i.e. confidence) about their accuracy. Studying objects again in Experiment 2 and individual people in Experiment 3, participants completed a self-paced block on Day 1 with unlimited study time, and completed a computer-paced block using the average of their self-paced study time on Day 8. Although performance was again higher after the self-paced study of objects in Experiment 2, such was not the case when controlling their study of people in Experiment 3 - perhaps complicated by factors such as attractiveness and distinctiveness. In both Experiment 2 and 3, the amount of time studying each item was again not only a significant predictor of recognition accuracy, but also of participants' confidence in their identification. The study of visual material may be profitably informed by metacognitive control and during retrieval later by metacognitive monitoring. Meeting abstract presented at VSS 2015. PMID:26325773

  3. Long-Term Memory: A Review and Meta-Analysis of Studies of Declarative and Procedural Memory in Specific Language Impairment

    Science.gov (United States)

    Lum, Jarrad A. G.; Conti-Ramsden, Gina

    2013-01-01

    This review examined the status of long-term memory systems in specific language impairment (SLI)--declarative memory and aspects of procedural memory in particular. Studies included in the review were identified following a systematic search of the literature and findings combined using meta-analysis. This review showed that individuals with SLI…

  4. Aluminium chloride impairs long-term memory and downregulates cAMP-PKA-CREB signalling in rats.

    Science.gov (United States)

    Zhang, Lifeng; Jin, Cuihong; Lu, Xiaobo; Yang, Jinghua; Wu, Shengwen; Liu, Qiufang; Chen, Rong; Bai, Chunyu; Zhang, Di; Zheng, Linlin; Du, Yanqiu; Cai, Yuan

    2014-09-01

    Epidemiological investigations have indicated that aluminium (Al) is an important environmental neurotoxicant that may be involved in the aetiology of the cognitive dysfunction associated with neurodegenerative diseases. Additionally, exposure to Al is known to cause neurobehavioural abnormalities in animals. Previous studies demonstrated that Al impaired early-phase long-term potentiation (E-LTP) in vivo and in vitro. Our previous research revealed that Al could impair long-term memory via the impairment of late-phase long-term potentiation (L-LTP) in vivo. However, the exact mechanism by which Al impairs long-term memory has been poorly studied thus far. This study was designed not only to observe the effects of subchronic Al treatment on long-term memory and hippocampal ultrastructure but also to explore a possible underlying mechanism (involving the cAMP-PKA-CREB signalling pathway) in the hippocampus of rats.. Pregnant Wistar rats were assigned to four groups. Neonatal rats were exposed to Al by parental lactation for 3 weeks and then fed with distilled water containing 0, 0.2%, 0.4% or 0.6% Al chloride (AlCl3) for 3 postnatal months. The levels of Al in the blood and hippocampus were quantified by atomic absorption spectrophotometry. The shuttle-box test was performed to detect long-term memory. The hippocampus was collected for ultrastructure observation, and the level of cAMP-PKA-CREB signalling was examined. The results showed that the Al concentrations in the blood and hippocampus of Al-treated rats were higher than those of the control rats. Al may impair the long-term memory of rats. Hippocampal cAMP, cPKA, pCREB, BDNF and c-jun expression decreased significantly, and the neuronal and synaptic ultrastructure exhibited pathological changes after Al treatment. These results indicated that Al may induce long-term memory damage in rats by inhibiting cAMP-PKA-CREB signalling and altering the synaptic and neuronal ultrastructure in the hippocampus. PMID:24973631

  5. Theta Oscillations Track the Content of Representations Retrieved from Long Term Memory.

    Science.gov (United States)

    Sutterer, David; Anderson, David; Serences, John; Vogel, Edward; Awh, Edward

    2015-09-01

    Recent work has demonstrated that it is possible to reconstruct orientation selective channel tuning functions (CTFs) during the encoding and delay period of a working memory (WM) task using a forward encoding model and electroencephalography (EEG). Specifically these CTFs can be derived from the distribution of alpha-band (8-12hz) activity across the scalp (Anderson et al. 2014), providing a high temporal resolution measure of the content and quality of WM representations. The goal of the present work was to determine whether we could employ a similar approach to track the content of representations retrieved from long term memory (LTM). Subjects (n = 24) learned randomly assigned colors for a collection of 120 unique shapes, with the color selected from a continuous 360 degree space. Twenty four hours after the initial learning session, subjects were presented with shape cues and asked to retrieve the associated color while EEG was recorded. We found that robust color-selective CTFs could be obtained from the distribution of evoked theta-band (4-7 hz) activity during the first 400 ms following the onset of the shape cue. We replicated this pattern of results with a spatial LTM task identical to the color task save that subjects learned and reported the position of 120 unique shapes from 360 degrees of space around a circle (n = 26). Together these results reveal that the content of representations retrieved from LTM is tracked by phasic activity in the theta-frequency band, and that this pattern of results generalizes across visual features. These findings dovetail with the longstanding consensus that low frequency activity in the theta band is integral to LTM function, and they provide a powerful new method for measuring the temporal dynamics of LTM retrieval. Meeting abstract presented at VSS 2015. PMID:26326801

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

    Science.gov (United States)

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

    2012-01-01

    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…

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

    Science.gov (United States)

    Schaap, Lydia; Verkoeijen, Peter; Schmidt, Henk

    2014-01-01

    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…

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

    OpenAIRE

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

    2006-01-01

    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...

  9. Drosophila ORB protein in two mushroom body output neurons is necessary for long-term memory formation

    OpenAIRE

    Pai, Tsung-Pin; Chen, Chun-Chao; Lin, Hui-Hao; Chin, An-Lun; Lai, Jason Sih-Yu; Lee, Pei-Tseng; Tully, Tim; Chiang, Ann-shyn

    2013-01-01

    Memory is initially labile and gradually consolidated over time through new protein synthesis into a long-lasting stable form. Studies of odor-shock associative learning in Drosophila have established the mushroom body (MB) as a key brain structure involved in olfactory long-term memory (LTM) formation. Exactly how early neural activity encoded in thousands of MB neurons is consolidated into protein-synthesis–dependent LTM remains unclear. Here, several independent lines of evidence indicate ...

  10. When Music and Long-Term Memory Interact: Effects of Musical Expertise on Functional and Structural Plasticity in the Hippocampus

    OpenAIRE

    Groussard, Mathilde; La Joie, Renaud; Rauchs, Géraldine; Landeau, Brigitte; Chételat, Gaël; Viader, Fausto; Desgranges, Béatrice; Eustache, Francis; Platel, Hervé

    2010-01-01

    The development of musical skills by musicians results in specific structural and functional modifications in the brain. Surprisingly, no functional magnetic resonance imaging (fMRI) study has investigated the impact of musical training on brain function during long-term memory retrieval, a faculty particularly important in music. Thus, using fMRI, we examined for the first time this process during a musical familiarity task (i.e., semantic memory for music). Musical expertise induced supplem...

  11. Genetic Activation of ERK5 MAP Kinase Enhances Adult Neurogenesis and Extends Hippocampus-Dependent Long-Term Memory

    OpenAIRE

    Wang, Wenbin; Pan, Yung-Wei; Zou, Junhui; Li, Tan; Abel, Glen M.; Palmiter, Richard D; Storm, Daniel R.; Xia, Zhengui

    2014-01-01

    Recent studies have shown that inhibition of adult neurogenesis impairs the formation of hippocampus-dependent memory. However, it is not known whether increasing adult neurogenesis affects the persistence of hippocampus-dependent long-term memory. Furthermore, signaling mechanisms that regulate adult neurogenesis are not fully defined. We recently reported that the conditional and targeted knock-out of ERK5 MAP kinase in adult neurogenic regions of the mouse brain attenuates adult neurogenes...

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

    CERN Document Server

    Kristoufek, Ladislav

    2014-01-01

    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 the separate processes. The bivariate Hurst exponent is then equal to an average of the separate Hurst exponents of the analysed processes. Strength of the short term memory has no effect on these asymptotic properties.

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

    OpenAIRE

    Kristoufek, Ladislav

    2014-01-01

    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...

  14. 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)

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

    DEFF Research Database (Denmark)

    Guerrieri, Fernando Javier; D'Ettorre, Patrizia

    2011-01-01

    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.

  16. Hippocampal CA1 Kindling but Not Long-Term Potentiation Disrupts Spatial Memory Performance

    Science.gov (United States)

    Leung, L. Stan; Shen, Bixia

    2006-01-01

    Long-term synaptic enhancement in the hippocampus has been suggested to cause deficits in spatial performance. Synaptic enhancement has been reported after hippocampal kindling that induced repeated electrographic seizures or afterdischarges (ADs) and after long-term potentiation (LTP) defined as synaptic enhancement without ADs. We studied…

  17. Long-Term Heavy Ketamine Use is Associated with Spatial Memory Impairment and Altered Hippocampal Activation

    OpenAIRE

    Morgan, Celia J A; Dodds, Chris M.; Furby, Hannah; Pepper, Fiona; Fam, Johnson; Freeman, Tom P; Hughes, Emer; Doeller, Christian; King, John; Howes, Oliver; Stone, James M

    2014-01-01

    Ketamine, a non-competitive N-methyl-d-aspartate receptor antagonist, is rising in popularity as a drug of abuse. Preliminary evidence suggests that chronic, heavy ketamine use may have profound effects on spatial memory but the mechanism of these deficits is as yet unclear. This study aimed to examine the neural mechanism by which heavy ketamine use impairs spatial memory processing. In a sample of 11 frequent ketamine users and 15 poly-drug controls, matched for IQ, age, years in education....

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

    Directory of Open Access Journals (Sweden)

    Pierre-Yves Plaçais

    2013-11-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Oikawa Kensuke

    2012-07-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Watson Shawn N

    2012-08-01

    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.

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

    OpenAIRE

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

    1998-01-01

    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 ...

  2. Differences in long-term memory stability and AmCREB level between forward and backward conditioned honeybees (Apis mellifera)

    Science.gov (United States)

    Felsenberg, Johannes; Dyck, Yan; Feige, Janina; Ludwig, Jenny; Plath, Jenny Aino; Froese, Anja; Karrenbrock, Melanie; Nölle, Anna; Heufelder, Karin; Eisenhardt, Dorothea

    2015-01-01

    In classical conditioning a predictive relationship between a neutral stimulus (conditioned stimulus; CS) and a meaningful stimulus (unconditioned stimulus; US) is learned when the CS precedes the US. In backward conditioning the sequence of the stimuli is reversed. In this situation animals might learn that the CS signals the end or the absence of the US. In honeybees 30 min and 24 h following backward conditioning a memory for the excitatory and inhibitory properties of the CS could be retrieved, but it remains unclear whether a late long-term memory is formed that can be retrieved 72 h following backward conditioning. Here we examine this question by studying late long-term memory formation in forward and backward conditioning of the proboscis extension response (PER). We report a difference in the stability of memory formed upon forward and backward conditioning with the same number of conditioning trials. We demonstrate a transcription-dependent memory 72 h after forward conditioning but do not observe a 72 h memory after backward conditioning. Moreover we find that protein degradation is differentially involved in memory formation following these two conditioning protocols. We report differences in the level of a transcription factor, the cAMP response element binding protein (CREB) known to induce transcription underlying long-term memory formation, following forward and backward conditioning. Our results suggest that these alterations in CREB levels might be regulated by the proteasome. We propose that the differences observed are due to the sequence of stimulus presentation between forward and backward conditioning and not to differences in the strength of the association of both stimuli. PMID:25964749

  3. Long-term avoidance memory formation is associated with a transient increase in mushroom body synaptic complexes in leaf-cutting ants

    OpenAIRE

    Falibene, Agustina; Roces, Flavio; Rössler, Wolfgang

    2015-01-01

    Long-term behavioral changes related to learning and experience have been shown to be associated with structural remodeling in the brain. Leaf-cutting ants learn to avoid previously preferred plants after they have proved harmful for their symbiotic fungus, a process that involves long-term olfactory memory. We studied the dynamics of brain microarchitectural changes after long-term olfactory memory formation following avoidance learning in Acromyrmex ambiguus. After performing experiments to...

  4. The compensatory effect of regular exercise on long-term memory impairment in sleep deprived female rats.

    Science.gov (United States)

    Salari, Maryam; Sheibani, Vahid; Saadati, Hakimeh; Pourrahimi, Alimohammad; khaksarihadad, Mohammad; Esmaeelpour, Khadijeh; Khodamoradi, Mehdi

    2015-10-01

    Previous studies have been shown that exercise can improve short-term spatial learning, memory and synaptic plasticity impairments in sleep deprived female rats. The aim of the present study was to investigate the effects of treadmill exercise on sleep deprivation (SD) induced impairment in hippocampal dependent long-term memory in female rats. Intact and ovariectomized female rats were used in the current study. Exercise protocol was 4 weeks treadmill running. Twenty four hour SD was induced by using multiple platform apparatus after learning phase. Spatial learning and long-term memory was examined by using the Morris Water Maze (MWM) test. Our results indicated that sleep deprivation impaired long term memory in the intact and ovariectomized female rats, regardless of reproductive status (pimpairment (p<0.05). In conclusion the results of the current study confirmed the negative effect of SD on cognitive functions and regular exercise seems to protect rats from these factors, however more investigations need to be done. PMID:26190016

  5. ADRA2B deletion variant selectively predicts stress-induced enhancement of long-term memory in females.

    Science.gov (United States)

    Zoladz, Phillip R; Kalchik, Andrea E; Hoffman, Mackenzie M; Aufdenkampe, Rachael L; Lyle, Sarah M; Peters, David M; Brown, Callie M; Cadle, Chelsea E; Scharf, Amanda R; Dailey, Alison M; Wolters, Nicholas E; Talbot, Jeffery N; Rorabaugh, Boyd R

    2014-10-01

    Clarifying the mechanisms that underlie stress-induced alterations of learning and memory may lend important insight into susceptibility factors governing the development of stress-related psychological disorders, such as post-traumatic stress disorder (PTSD). Previous work has shown that carriers of the ADRA2B Glu(301)-Glu(303) deletion variant exhibit enhanced emotional memory, greater amygdala responses to emotional stimuli and greater intrusiveness of traumatic memories. We speculated that carriers of this deletion variant might also be more vulnerable to stress-induced enhancements of long-term memory, which would implicate the variant as a possible susceptibility factor for traumatic memory formation. One hundred and twenty participants (72 males, 48 females) submerged their hand in ice cold (stress) or warm (no stress) water for 3min. Immediately afterwards, they studied a list of 42 words varying in emotional valence and arousal and then completed an immediate free recall test. Twenty-four hours later, participants' memory for the word list was examined via free recall and recognition assessments. Stressed participants exhibiting greater heart rate responses to the stressor had enhanced recall on the 24-h assessment. Importantly, this enhancement was independent of the emotional nature of the learned information. In contrast to previous work, we did not observe a general enhancement of memory for emotional information in ADRA2B deletion carriers. However, stressed female ADRA2B deletion carriers, particularly those exhibiting greater heart rate responses to the stressor, did demonstrate greater recognition memory than all other groups. Collectively, these findings implicate autonomic mechanisms in the pre-learning stress-induced enhancement of long-term memory and suggest that the ADRA2B deletion variant may selectively predict stress effects on memory in females. Such findings lend important insight into the physiological mechanisms underlying stress effects on learning and their sex-dependent nature. PMID:24997351

  6. Effects of D-amino acid oxidase inhibition on memory performance and long-term potentiation in vivo

    OpenAIRE

    Hopkins, Seth C.; Campbell, Una C; Heffernan, Michele L R; Spear, Kerry L; Jeggo, Ross D; Spanswick, David C.; Varney, Mark A; Large, Thomas H

    2013-01-01

    N-methyl-d-aspartate receptor (NMDAR) activation can initiate changes in synaptic strength, evident as long-term potentiation (LTP), and is a key molecular correlate of memory formation. Inhibition of d-amino acid oxidase (DAAO) may increase NMDAR activity by regulating d-serine concentrations, but which neuronal and behavioral effects are influenced by DAAO inhibition remain elusive. In anesthetized rats, extracellular field excitatory postsynaptic potentials (fEPSPs) were recorded before an...

  7. CREB expression in the brains of two closely related parasitic wasp species that differ in long-term memory formation

    OpenAIRE

    Berg, M.; Verbaarschot, P.G.H.; Hontelez, S.; Vet, L.E.M.; Dicke, M.; Smid, H M

    2010-01-01

    The cAMP/PKA signalling pathway and transcription factor cAMP response element-binding protein (CREB) play key roles in long-term memory (LTM) formation. We used two closely related parasitic wasp species, Cotesia glomerata and Cotesia rubecula, which were previously shown to be different in LTM formation, and sequenced at least nine different CREB transcripts in both wasp species. The splicing patterns, functional domains and amino acid sequences were similar to those found in the CREB genes...

  8. Learning to never forget—time scales and specificity of long-term memory of a motor skill

    OpenAIRE

    DagmarSternad; Se-WoongPark; TjeerdDijkstra

    2013-01-01

    Despite anecdotal reports that humans retain acquired motor skills for many years, if not a lifetime, long-term memory of motor skills has received little attention. While numerous neuroimaging studies showed practice-induced cortical plasticity, the behavioral correlates, what is retained and also what is forgotten, are little understood. This longitudinal case study on four subjects presents detailed kinematic analyses of humans practicing a bimanual polyrhythmic task over 2 months with ret...

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

    Directory of Open Access Journals (Sweden)

    AmedeoD'Angiulli

    2013-02-01

    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.

  10. Effects of Sleep Deprivation and Aging on Long-Term and Remote Memory in Mice

    Science.gov (United States)

    Vecsey, Christopher G.; Park, Alan J.; Khatib, Nora; Abel, Ted

    2015-01-01

    Sleep deprivation (SD) following hippocampus-dependent learning in young mice impairs memory when tested the following day. Here, we examined the effects of SD on remote memory in both young and aged mice. In young mice, we found that memory is still impaired 1 mo after training. SD also impaired memory in aged mice 1 d after training, but, by a…

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

    OpenAIRE

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

    2006-01-01

    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 augm...

  12. Get the gist? The effects of processing depth on false recognition in short-term and long-term memory.

    Science.gov (United States)

    Flegal, Kristin E; Reuter-Lorenz, Patricia A

    2014-07-01

    Gist-based processing has been proposed to account for robust false memories in the converging-associates task. The deep-encoding processes known to enhance verbatim memory also strengthen gist memory and increase distortions of long-term memory (LTM). Recent research has demonstrated that compelling false memory illusions are relatively delay-invariant, also occurring under canonical short-term memory (STM) conditions. To investigate the contributions of gist to false memory at short and long delays, processing depth was manipulated as participants encoded lists of four semantically related words and were probed immediately, following a filled 3- to 4-s retention interval, or approximately 20 min later, in a surprise recognition test. In two experiments, the encoding manipulation dissociated STM and LTM on the frequency, but not the phenomenology, of false memory. Deep encoding at STM increases false recognition rates at LTM, but confidence ratings and remember/know judgments are similar across delays and do not differ as a function of processing depth. These results suggest that some shared and some unique processes underlie false memory illusions at short and long delays. PMID:24395065

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-01

    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.

  14. The Sleep Elaboration-Awake Pruning (SEAP) theory of memory: long term memories grow in complexity during sleep and undergo selection while awake. Clinical, psychopharmacological and creative implications.

    Science.gov (United States)

    Charlton, Bruce G; Andras, Peter

    2009-07-01

    Long term memory (LTM) systems need to be adaptive such that they enhance an organism's reproductive fitness and self-reproducing in order to maintain their complexity of communications over time in the face of entropic loss of information. Traditional 'representation-consolidation' accounts conceptualize memory adaptiveness as due to memories being 'representations' of the environment, and the longevity of memories as due to 'consolidation' processes. The assumption is that memory representations are formed while an animal is awake and interacting with the environment, and these memories are consolidated mainly while the animal is asleep. So the traditional view of memory is 'instructionist' and assumes that information is transferred from the environment into the brain. By contrast, we see memories as arising endogenously within the brain's LTM system mainly during sleep, to create complex but probably maladaptive memories which are then simplified ('pruned') and selected during the awake period. When awake the LTM system is brought into a more intense interaction with past and present experience. Ours is therefore a 'selectionist' account of memory, and could be termed the Sleep Elaboration-Awake Pruning (or SEAP) theory. The SEAP theory explains the longevity of memories in the face of entropy by the tendency for memories to grow in complexity during sleep; and explains the adaptiveness of memory by selection for consistency with perceptions and previous memories during the awake state. Sleep is therefore that behavioural state during which most of the internal processing of the system of LTM occurs; and the reason sleep remains poorly understood is that its primary activity is the expansion of long term memories. By re-conceptualizing the relationship between memory, sleep and the environment; SEAP provides a radically new framework for memory research, with implications for the measurement of memory and the design of empirical investigations in clinical, psychopharmacological and creative domains. For example, it would be predicted that states of insufficient alertness such as delirium would produce errors of commission (memory distortion and false memories, as with psychotic delusions), while sleep deprivation would produce errors of memory omission (memory loss). Ultimately, the main argument in favour of SEAP is that long term memory must be a complex adaptive system, and complex systems arise, are selected and sustained according to the principles of systems theory; and therefore LTM cannot be functioning in the way assumed by 'representation-consolidation' theories. PMID:19349123

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

    Directory of Open Access Journals (Sweden)

    Cristina M Alberini

    2011-03-01

    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.

  16. Following the crowd: Brain Substrates of Long-Term Memory Conformity

    OpenAIRE

    Edelson, Micah; Sharot, Tali; Dolan, Raymond J.; Dudai, Yadin

    2011-01-01

    Human memory is strikingly susceptible to social influences, yet we know little about the underlying mechanisms. We examined how socially induced memory errors are generated in the brain by studying the memory of individuals exposed to recollections of others. Participants exhibited a strong tendency to conform to erroneous recollections of the group, producing both long-lasting and temporary errors, even when their initial memory was strong and accurate. Functional brain imaging revealed tha...

  17. Depletion of Perineuronal Nets Enhances Recognition Memory and Long-Term Depression in the Perirhinal Cortex

    OpenAIRE

    2013-01-01

    Perineuronal nets are extracellular matrix structures surrounding cortical neuronal cell bodies and proximal dendrites, and are involved in the control of brain plasticity and the closure of critical periods. Expression of the link protein Crtl1/Hapln1 in neurons has recently been identified as the key event triggering the formation of perineuronal nets. Here we show that the genetic attenuation of perineuronal nets in adult brain Crtl1 knockout mice enhances long term object recognition memo...

  18. Mind racing: The influence of exercise on long-term memory consolidation.

    Science.gov (United States)

    McNerney, M Windy; Radvansky, Gabriel A

    2015-11-01

    Over time, regular exercise can lower the risk for age-related decline in cognition. However, the immediate effects of exercise on memory consolidation in younger adults have not been fully investigated. In two experiments, the effects of exercise were assessed on three different memory tasks. These included paired-associate learning, procedural learning and text memory. Results indicate that performance on procedural learning and situation model memory was increased with exercise, regardless of if participants exercised before or after encoding. No benefit of exercise was found for paired-associate learning. These findings suggest that intense exercise may benefit certain types of memory consolidation. PMID:25312348

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

    OpenAIRE

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

    2006-01-01

    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 investiga...

  20. The hippocampus remains activated over the long term for the retrieval of truly episodic memories.

    Science.gov (United States)

    Harand, Caroline; Bertran, Françoise; La Joie, Renaud; Landeau, Brigitte; Mézenge, Florence; Desgranges, Béatrice; Peigneux, Philippe; Eustache, Francis; Rauchs, Géraldine

    2012-01-01

    The role of the hippocampus in declarative memory consolidation is a matter of intense debate. We investigated the neural substrates of memory retrieval for recent and remote information using functional magnetic resonance imaging (fMRI). 18 young, healthy participants learned a series of pictures. Then, during two fMRI recognition sessions, 3 days and 3 months later, they had to determine whether they recognized or not each picture using the "Remember/Know" procedure. Presentation of the same learned images at both delays allowed us to track the evolution of memories and distinguish consistently episodic memories from those that were initially episodic and then became familiar or semantic over time and were retrieved without any contextual detail. Hippocampal activation decreased over time for initially episodic, later semantic memories, but remained stable for consistently episodic ones, at least in its posterior part. For both types of memories, neocortical activations were observed at both delays, notably in the ventromedial prefrontal and anterior cingulate cortices. These activations may reflect a gradual reorganization of memory traces within neural networks. Our data indicate maintenance and strengthening of hippocampal and cortico-cortical connections in the consolidation and retrieval of episodic memories over time, in line with the Multiple Trace theory (Nadel and Moscovitch, 1997). At variance, memories becoming semantic over time consolidate through strengthening of cortico-cortical connections and progressive disengagement of the hippocampus. PMID:22937055

  1. EFFECTS OF LONG-TERM MEMANTINE ON MEMORY AND NEUROPATHOLOGY IN TS65DN MICE, A MODEL FOR DOWN SYNDROME

    OpenAIRE

    Lockrow, Jason; Boger, Heather; Bimonte-Nelson, Heather; Granholm, Ann-Charlotte

    2010-01-01

    Memantine is a partial NMDA receptor antagonist that has been shown to improve learning and memory in several animal models, and is approved for the treatment of Alzheimer’s disease. Chronic treatments using memantine in animal models of Alzheimer’s disease show disease-modifying effects and suggest a potential neuroprotective function. The present study assessed the effects of both short- and long-term memantine treatment in a mouse model of Down syndrome, the Ts65Dn mouse. The Ts65Dn mouse ...

  2. Consolidation power of extrinsic rewards: reward cues enhance long-term memory for irrelevant past events

    OpenAIRE

    Murayama, Kou; Kitagami, Shinji

    2014-01-01

    Recent research suggests that extrinsic rewards promote memory consolidation through dopaminergic modulation processes. However, no conclusive behavioral evidence exists given that the influence of extrinsic reward on attention and motivation during encoding and consolidation processes are inherently confounded. The present study provides behavioral evidence that extrinsic rewards (i.e., monetary incentives) enhance human memory consolidation independently of attention and motivation. Partici...

  3. Transient Relay Function of Midline Thalamic Nuclei during Long-Term Memory Consolidation in Humans

    Science.gov (United States)

    Thielen, Jan-Willem; Takashima, Atsuko; Rutters, Femke; Tendolkar, Indira; Fernández, Guillén

    2015-01-01

    To test the hypothesis that thalamic midline nuclei play a transient role in memory consolidation, we reanalyzed a prospective functional MRI study, contrasting recent and progressively more remote memory retrieval. We revealed a transient thalamic connectivity increase with the hippocampus, the medial prefrontal cortex (mPFC), and a…

  4. Long-term phonological knowledge supports serial ordering in working memory.

    Science.gov (United States)

    Nakayama, Masataka; Tanida, Yuki; Saito, Satoru

    2015-09-01

    Serial ordering mechanisms have been investigated extensively in psychology and psycholinguistics. It has also been demonstrated repeatedly that long-term phonological knowledge contributes to serial ordering. However, the mechanisms that contribute to serial ordering have yet to be fully understood. To understand these mechanisms, we demonstrate 2 effects using triples of Japanese nonwords in immediate serial recall. One, a type of bielement frequency effect, is a retrograde compatibility effect. Bielement frequency effects are well-established phenomena whereby a 2-element sequence (e.g., "ka-re") that frequently appears in a language instantiates better recall of any sequence that includes this element (e.g., "ka-re-su-mo"). We demonstrate that bielement frequency affected both the first (e.g., "ka" for "ka-re"; retrograde compatibility effect) and second part of a sequence, indicating the existence of minicontext representations of 2-element sequences. The other effects are the position-element(s) frequency effects, whereby an element (e.g., the mora "ka") that more frequently appears in 1 position of a sequence (e.g., in the first mora of a word) than in other positions facilitates better recall of that element (i.e., the first mora). The effects demonstrated in this article indicate the long-term associations of position representations and elements. These effects are discussed in terms of the extensive learning hypothesis, which assumes that phonological structures are learned gradually. Implications for computational models are also discussed. PMID:25730304

  5. 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 of memory processing

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

    OpenAIRE

    ZHANG, Ming; Wang, Hongbing

    2013-01-01

    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...

  7. LONG-TERM AGROECOSYSTEM EXPERIMENTS AND SAMPLE ARCHIVES AT USDA-ARS-NGPRL

    Science.gov (United States)

    The USDA-ARS Northern Great Plains Research Laboratory (NGPRL) near Mandan, North Dakota, USA (46º 46’ 12” N, 100º 54’ 57” W) was established in 1914, and currently manages three long-term agroecosystem experiments, each related to a different form of grazing management. Two native vegetation pastu...

  8. Consolidation power of extrinsic rewards: reward cues enhance long-term memory for irrelevant past events.

    Science.gov (United States)

    Murayama, Kou; Kitagami, Shinji

    2014-02-01

    Recent research suggests that extrinsic rewards promote memory consolidation through dopaminergic modulation processes. However, no conclusive behavioral evidence exists given that the influence of extrinsic reward on attention and motivation during encoding and consolidation processes are inherently confounded. The present study provides behavioral evidence that extrinsic rewards (i.e., monetary incentives) enhance human memory consolidation independently of attention and motivation. Participants saw neutral pictures, followed by a reward or control cue in an unrelated context. Our results (and a direct replication study) demonstrated that the reward cue predicted a retrograde enhancement of memory for the preceding neutral pictures. This retrograde effect was observed only after a delay, not immediately upon testing. An additional experiment showed that emotional arousal or unconscious resource mobilization cannot explain the retrograde enhancement effect. These results provide support for the notion that the dopaminergic memory consolidation effect can result from extrinsic reward. PMID:23421444

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

    Scientific Electronic Library Online (English)

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

    2006-03-01

    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 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

  10. Brain potentials during sentence verification: late negativity and long-term memory strength.

    Science.gov (United States)

    Fischler, I; Bloom, P A; Childers, D G; Arroyo, A A; Perry, N W

    1984-01-01

    Subjects decided whether self-referential statements were true or false. Event-related potentials (ERPs) associated with final words creating false statements displayed a late negativity (N340) relative to ERPs for true completions. The size of this difference between true and false statements was greater for highly familiar statements (e.g. "My name is Ira") than for less familiar ones (e.g. "I go to bed late") even after all the statements had been practised a number of times. The late negativity appears to be associated with a discrepancy between presented and remembered information, and its magnitude reflects the long-term familiarity or strength of the remembered information. PMID:6504296

  11. False memories and lexical decision: even twelve primes do not cause long-term semantic priming

    OpenAIRE

    Zeelenberg, R.; Pecher, D.

    2002-01-01

    Semantic priming effects are usually obtained only if the prime is presented shortly before the target stimulus. Recent evidence obtained with the so-called false memory paradigm suggests, however, that in both explicit and implicit memory tasks semantic relations between words can result in long-lasting effects when multiple 'primes' are presented. The aim of the present study was to investigate whether these effects would generalize to lexical decision. In four experiments...

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

    OpenAIRE

    Milton, F; Muhlert, N; Butler, CR; Smith, A.; Benattayallah, A; Zeman, AZ

    2011-01-01

    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...

  13. Posterior parietal cortex and long-term memory: some data from laboratory animals

    OpenAIRE

    Jociane C. Myskiw; Izquierdo, Iván

    2012-01-01

    The posterior parietal cortex (PPC) was long viewed as just involved in the perception of spatial relationships between the body and its surroundings and of movements related to them. In recent years the PPC has been shown to participate in many other cognitive processes, among which working memory and the consolidation and retrieval of episodic memory. The neurotransmitter and other molecular processes involved have been determined to a degree in rodents. More research will no doubt determin...

  14. POSTERIOR PARIETAL CORTEX AND LONG-TERM MEMORY: SOME DATA FROM LABORATORY ANIMALS

    OpenAIRE

    IvánIzquierdo

    2012-01-01

    The posterior parietal cortex (PPC), long viewed as just involved in the perception of spatial relationships between the body and its surroundings and of movements related to it has in recent years been shown to participate in many other cognitive processes, among which working memory and the consolidation and retrieval of episodic memory. The neurotransmitter and other molecular processes involved have been determined to a degree in rodents. More research will no doubt determine the extent...

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

    OpenAIRE

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

    2007-01-01

    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...

  16. Unforgettable film music: The role of emotion in episodic long-term memory for music

    OpenAIRE

    Altenmüller Eckart O; Münte Thomas F; Eschrich Susann

    2008-01-01

    Abstract Background Specific pieces of music can elicit strong emotions in listeners and, possibly in connection with these emotions, can be remembered even years later. However, episodic memory for emotional music compared with less emotional music has not yet been examined. We investigated whether emotional music is remembered better than less emotional music. Also, we examined the influence of musical structure on memory performance. Results Recognition of 40 musical excerpts was investiga...

  17. Conversion of short-term to long-term memory in the novel object recognition paradigm

    OpenAIRE

    Moore, Shannon J.; Deshpande, Kaivalya; Stinnett, Gwen S.; Seasholtz, Audrey F.; Geoffrey G Murphy

    2013-01-01

    It is well-known that stress can significantly impact learning; however, whether this effect facilitates or impairs the resultant memory depends on the characteristics of the stressor. Investigation of these dynamics can be confounded by the role of the stressor in motivating performance in a task. Positing a cohesive model of the effect of stress on learning and memory necessitates elucidating the consequences of stressful stimuli independently from task-specific functions. Therefore, the go...

  18. Calcium/Calmodulin-dependent Protein Kinase II is a Ubiquitous Molecule in Human Long-term Memory Synaptic Plasticity: A Systematic Review

    Science.gov (United States)

    Ataei, Negar; Sabzghabaee, Ali Mohammad; Movahedian, Ahmad

    2015-01-01

    Background: Long-term memory is based on synaptic plasticity, a series of biochemical mechanisms include changes in structure and proteins of brain's neurons. In this article, we systematically reviewed the studies that indicate calcium/calmodulin kinase II (CaMKII) is a ubiquitous molecule among different enzymes involved in human long-term memory and the main downstream signaling pathway of long-term memory. Methods: All of the observational, case–control and review studies were considered and evaluated by the search engines PubMed, Cochrane Central Register of Controlled Trials and ScienceDirect Scopus between 1990 and February 2015. We did not carry out meta-analysis. Results: At the first search, it was fined 1015 articles which included “synaptic plasticity” OR “neuronal plasticity” OR “synaptic density” AND memory AND “molecular mechanism” AND “calcium/calmodulin-dependent protein kinase II” OR CaMKII as the keywords. A total of 335 articles were duplicates in the databases and eliminated. A total of 680 title articles were evaluated. Finally, 40 articles were selected as reference. Conclusions: The studies have shown the most important intracellular signal of long-term memory is calcium-dependent signals. Calcium linked calmodulin can activate CaMKII. After receiving information for learning and memory, CaMKII is activated by Glutamate, the most important neurotransmitter for memory-related plasticity. Glutamate activates CaMKII and it plays some important roles in synaptic plasticity modification and long-term memory. PMID:26445635

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

    Directory of Open Access Journals (Sweden)

    H. Maldonado

    1997-07-01

    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

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

    Scientific Electronic Library Online (English)

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

    1997-07-01

    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

  1. 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.

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

    Science.gov (United States)

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

    2015-12-01

    Social isolation during the vulnerable period of adolescence produces emotional dysregulation that often manifests as abnormal behavior in adulthood. The enduring consequence of isolation might be caused by a weakened ability to forget unpleasant memories. However, it remains unclear whether isolation affects unpleasant memories. To address this, we used a model of associative learning to induce the fear memories and evaluated the influence of isolation mice during adolescence on the subsequent retention of fear memories and its underlying cellular mechanisms. Following adolescent social isolation, we found that mice decreased their social interaction time and had an increase in anxiety-related behavior. Interestingly, when we assessed memory retention, we found that isolated mice were unable to forget aversive memories when tested 4 weeks after the original event. Consistent with this, we observed that a single train of high-frequency stimulation (HFS) enabled a late-phase long-term potentiation (L-LTP) in the hippocampal CA1 region of isolated mice, whereas only an early-phase LTP was observed with the same stimulation in the control mice. Social isolation during adolescence also increased brain-derived neurotrophic factor (BDNF) expression in the hippocampus, and application of a tropomyosin-related kinase B (TrkB) receptor inhibitor ameliorated the facilitated L-LTP seen after isolation. Together, our results suggest that adolescent isolation may result in mental disorders during adulthood and that this may stem from an inability to forget the unpleasant memories via BDNF-mediated synaptic plasticity. These findings may give us a new strategy to prevent mental disorders caused by persistent unpleasant memories. PMID:25860250

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

    Science.gov (United States)

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

    2014-05-01

    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.

  4. POSTERIOR PARIETAL CORTEX AND LONG-TERM MEMORY: SOME DATA FROM LABORATORY ANIMALS

    Directory of Open Access Journals (Sweden)

    Iván Izquierdo

    2012-02-01

    Full Text Available The posterior parietal cortex (PPC, long viewed as just involved in the perception of spatial relationships between the body and its surroundings and of movements related to it has in recent years been shown to participate in many other cognitive processes, among which working memory and the consolidation and retrieval of episodic memory. The neurotransmitter and other molecular processes involved have been determined to a degree in rodents. More research will no doubt determine the extent to which these findings can be extrapolated to primates, including humans. In these there appears to be a paradox: imaging studies strongly suggest an important participation of the PPC in episodic memory, whereas lesion studies are much less suggestive, let alone conclusive.

  5. Emotion and memory: Children's long-term remembering, forgetting, and suggestibility.

    Science.gov (United States)

    Quas, J A; Goodman, G S; Bidrose, S; Pipe, M E; Craw, S; Ablin, D S

    1999-04-01

    Children's memories for an experienced and a never-experienced medical procedure were examined. Three- to 13-year-olds were questioned about a voiding cystourethrogram fluoroscopy (VCUG) they endured between 2 and 6 years of age. Children 4 years or older at VCUG were more accurate than children younger than 4 at VCUG. Longer delays were associated with providing fewer units of correct information but not with more inaccuracies. Parental avoidant attachment style was related to increased errors in children's VCUG memory. Children were more likely to assent to the false medical procedure when it was alluded to briefly than when described in detail, and false assents were related to fewer "do-not-know" responses about the VCUG. Results have implications for childhood amnesia, stress and memory, individual differences, and eyewitness testimony. PMID:10074380

  6. Long-term avoidance memory formation is associated with a transient increase in mushroom body synaptic complexes in leaf-cutting ants

    Directory of Open Access Journals (Sweden)

    Agustina Falibene

    2015-04-01

    Full Text Available Long-term behavioral changes related to learning and experience have been shown to be associated with structural remodeling in the brain. Leaf-cutting ants learn to avoid previously preferred plants after they have proved harmful for their symbiotic fungus, a process that involves long-term olfactory memory. We studied the dynamics of brain microarchitectural changes after long-term olfactory memory formation following avoidance learning in Acromyrmex ambiguus. After performing experiments to control for possible neuronal changes related to age and body size, we quantified synaptic complexes (microglomeruli, MG in olfactory regions of the mushroom bodies (MB at different times after learning. Long-term avoidance memory formation was associated with a transient change in MG densities. Two days after learning, MG density was higher than before learning. At days 4 and 15 after learning — when ants still showed plant avoidance — MG densities had decreased to the initial state. The structural reorganization of MG triggered by long-term avoidance memory formation clearly differed from changes promoted by pure exposure to and collection of novel plants with distinct odors. Sensory exposure by the simultaneous collection of several, instead of one, non-harmful plant species resulted in a decrease in MG densities in the olfactory lip. We hypothesize that while sensory exposure leads to MG pruning in the MB olfactory lip, the formation of long-term avoidance memory involves an initial growth of new MG followed by subsequent pruning.

  7. Long-term avoidance memory formation is associated with a transient increase in mushroom body synaptic complexes in leaf-cutting ants.

    Science.gov (United States)

    Falibene, Agustina; Roces, Flavio; Rössler, Wolfgang

    2015-01-01

    Long-term behavioral changes related to learning and experience have been shown to be associated with structural remodeling in the brain. Leaf-cutting ants learn to avoid previously preferred plants after they have proved harmful for their symbiotic fungus, a process that involves long-term olfactory memory. We studied the dynamics of brain microarchitectural changes after long-term olfactory memory formation following avoidance learning in Acromyrmex ambiguus. After performing experiments to control for possible neuronal changes related to age and body size, we quantified synaptic complexes (microglomeruli, MG) in olfactory regions of the mushroom bodies (MBs) at different times after learning. Long-term avoidance memory formation was associated with a transient change in MG densities. Two days after learning, MG density was higher than before learning. At days 4 and 15 after learning-when ants still showed plant avoidance-MG densities had decreased to the initial state. The structural reorganization of MG triggered by long-term avoidance memory formation clearly differed from changes promoted by pure exposure to and collection of novel plants with distinct odors. Sensory exposure by the simultaneous collection of several, instead of one, non-harmful plant species resulted in a decrease in MG densities in the olfactory lip. We hypothesize that while sensory exposure leads to MG pruning in the MB olfactory lip, the formation of long-term avoidance memory involves an initial growth of new MG followed by subsequent pruning. PMID:25904854

  8. Long-term avoidance memory formation is associated with a transient increase in mushroom body synaptic complexes in leaf-cutting ants

    Science.gov (United States)

    Falibene, Agustina; Roces, Flavio; Rössler, Wolfgang

    2015-01-01

    Long-term behavioral changes related to learning and experience have been shown to be associated with structural remodeling in the brain. Leaf-cutting ants learn to avoid previously preferred plants after they have proved harmful for their symbiotic fungus, a process that involves long-term olfactory memory. We studied the dynamics of brain microarchitectural changes after long-term olfactory memory formation following avoidance learning in Acromyrmex ambiguus. After performing experiments to control for possible neuronal changes related to age and body size, we quantified synaptic complexes (microglomeruli, MG) in olfactory regions of the mushroom bodies (MBs) at different times after learning. Long-term avoidance memory formation was associated with a transient change in MG densities. Two days after learning, MG density was higher than before learning. At days 4 and 15 after learning—when ants still showed plant avoidance—MG densities had decreased to the initial state. The structural reorganization of MG triggered by long-term avoidance memory formation clearly differed from changes promoted by pure exposure to and collection of novel plants with distinct odors. Sensory exposure by the simultaneous collection of several, instead of one, non-harmful plant species resulted in a decrease in MG densities in the olfactory lip. We hypothesize that while sensory exposure leads to MG pruning in the MB olfactory lip, the formation of long-term avoidance memory involves an initial growth of new MG followed by subsequent pruning. PMID:25904854

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

    Science.gov (United States)

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

    2013-10-01

    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

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

    Science.gov (United States)

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

    2013-09-01

    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

  11. ROLE OF NEUROTRANSMITTERS AND PROTEIN SYNTHESIS IN SHORT- AND LONG-TERM MEMORY

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, E.L.; Rosenzweig, M.R.; Flood, J.F.

    1978-10-01

    Anisomycin is an effective inhibitor of cerebral protein synthesis in mice and is also an effective amnestic agent for both passive and active behavioral tasks. From use of anisomycin in combination with a variety of stimulant and depressant drugs, we conclude that the level of arousal following acquisition plays an important role in determining the duration and the rate of the biosynthetic phase of memory formation. While we have interpreted the experiments with anisomycin as evidence for an essential role of protein in memory storage, others have suggested that side effects of inhibitors of protein synthesis on catecholamine metabolism are the main cause of amnesia. Several experiments were therefore done to compare the effects of anisemycin and catecholamine inhibitors on memory. We conclude that anisomycin's principal amnestic mechanism does not involve inhibition of the catecholamine system. The results strengthen our conclusion that protein synthesis is an essential component for longterm memory trace formation. Also, it is suggested that proteins synthesized in the neuronal cell body are used, in conjunction with other molecules, to produce permanent and semi-permanent anatomical changes.

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

    Science.gov (United States)

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

    2012-01-01

    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…

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

    Science.gov (United States)

    Amano, Hisayuki; Maruyama, Ichiro N.

    2011-01-01

    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…

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-08-01

    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.

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

    International Nuclear Information System (INIS)

    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

  16. Early Shifts of Brain Metabolism by Caloric Restriction Preserve White Matter Integrity and Long-Term Memory in Aging Mice

    Science.gov (United States)

    Guo, Janet; Bakshi, Vikas; Lin, Ai-Ling

    2015-01-01

    Preservation of brain integrity with age is highly associated with lifespan determination. Caloric restriction (CR) has been shown to increase longevity and healthspan in various species; however, its effects on preserving living brain functions in aging remain largely unexplored. In the study, we used multimodal, non-invasive neuroimaging (PET/MRI/MRS) to determine in vivo brain glucose metabolism, energy metabolites, and white matter structural integrity in young and old mice fed with either control or 40% CR diet. In addition, we determined the animals’ memory and learning ability with behavioral assessments. Blood glucose, blood ketone bodies, and body weight were also measured. We found distinct patterns between normal aging and CR aging on brain functions?–?normal aging showed reductions in brain glucose metabolism, white matter integrity, and long-term memory, resembling human brain aging. CR aging, in contrast, displayed an early shift from glucose to ketone bodies metabolism, which was associated with preservations of brain energy production, white matter integrity, and long-term memory in aging mice. Among all the mice, we found a positive correlation between blood glucose level and body weight, but an inverse association between blood glucose level and lifespan. Our findings suggest that CR could slow down brain aging, in part due to the early shift of energy metabolism caused by lower caloric intake, and we were able to identify the age-dependent effects of CR non-invasively using neuroimaging. These results provide a rationale for CR-induced sustenance of brain health with extended longevity. PMID:26617514

  17. 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

    OpenAIRE

    Klein, Stanley B.

    2013-01-01

    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 ...

  18. 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

    OpenAIRE

    StanKlein

    2013-01-01

    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...

  19. Two distinct origins of long-term learning effects in verbal short-term memory

    OpenAIRE

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

    2012-01-01

    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 nonwords, but not digits. In contrast, list-level chunk learning affects serial recall of digits. In a first series of experiments, participants heard a co...

  20. Serial position effects in a singer's long term recall identify landmarks and lacunae in memory

    OpenAIRE

    Chaffin, Roger; Ginsborg, Jane; Dixon, James

    2009-01-01

    An experienced singer learned Stravinsky’s Ricercar 1, for soprano and small instrumental ensemble for public performance and annotated copies of the score to indicate the location of musical features that she attended to during practice and performance cues that she attended to during performance. During the next five years, she wrote out the words and music from memory six times. Recall was initially perfect, but declined over time as portions of the piece were progressively forgotten. Land...

  1. A requirement for memory retrieval during and after long-term extinction learning

    OpenAIRE

    Ouyang, Ming; Thomas, Steven A.

    2005-01-01

    Current learning theories are based on the idea that learning is driven by the difference between expectations and experience (the delta rule). In extinction, one learns that certain expectations no longer apply. Here, we test the potential validity of the delta rule by manipulating memory retrieval (and thus expectations) during extinction learning. Adrenergic signaling is critical for the time-limited retrieval (but not acquisition or consolidation) of contextual fear. Using genetic and pha...

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

    Science.gov (United States)

    Milton, F; Muhlert, N; Butler, C R; Smith, A; Benattayallah, A; Zeman, A Z

    2011-10-01

    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 parahippocampal gyrus (aPHG) at 5 months compared to a 36-hour retention interval. Familiarity was associated with greater activation in aPHG and posterior parahippocampal gyrus (pPHG) than recollection and new responses. Familiarity activation decreased over time in anterior hippocampus/aPHG and posterior hippocampus/pPHG. The engagement of neocortical regions such as medial prefrontal cortex at a 5-month delay, together with the reduced MTL activation at 5 months relative to at 36 hours is in line with the assumptions of Consolidation theory. SenseCam provides a valuable technique for assessing the processes that underlie remote everyday recognition memory. PMID:21409716

  3. Groundwater sampling from borehole KR6 during long-term pumping test at olkiluoto, Eurajoki in 2002

    International Nuclear Information System (INIS)

    A long-term pumping test from borehole KR6 at Olkiluoto was initiated in 2001. Both flow and in situ EC measurements as well as groundwater samplings from specific sections are being performed. The aim is to get information on the potential connections via fractures both to the sea and to the deep saline groundwater during long term pumping of the borehole. In 2002 and at the beginning of 2003 six groundwater samples were collected from borehole KR6 at three different sampling depths (98,5-100,5 m, 125-130 m and 135-137 m). Groundwater samples were taken from the packed-off sections by a membrane pump. Salinities of two groundwater samples from depths 98,5-100,5 m and 135-137 m were increasing due to the long term pumping of the borehole KR6. Whereas the salinity of the groundwater samples taken from section 125-130 m was decreasing between two groundwater samplings done in 2002. All taken groundwater samples represent water type Na-Ca-Cl and they are brackish (1 000 mg/l < TDS< 10 000 mg/l). Electrical conductivity, which was measured during the groundwater sampling, was compared to the in situ electrical conductivity measurements. The results achieved with different methods agreed well except for one sample. Based on EC results it can be concluded that groundwater samples taken from borehole KR6 represent good groundwater from a single fracture or narrow fracture zone. This study presents sampling methods and the results of analyses of groundwater samples from the deep borehole KR6. Beside these the report presents operating principles of the in situ EC measurements and also comparison of the results to the EC results measured during groundwater sampling. This report also contains a short comparison of the groundwater sampling results achieved in 2002 and 2003. (orig.)

  4. The development of the abilities to acquire novel detailed orthographic representations and maintain them in long-term memory.

    Science.gov (United States)

    Binamé, Florence; Poncelet, Martine

    2016-03-01

    Previous studies have clearly demonstrated that the development of orthographic representations relies on phonological recoding. However, substantial questions persist about the remaining unexplained variance in the acquisition of word-specific orthographic knowledge that is still underspecified. The main aim of this study was to explore whether two cognitive factors-sensitivity to orthographic regularities and short-term memory (STM) for serial order-make independent contributions to the acquisition of novel orthographic representations beyond that of the phonological core component and the level of preexisting word-specific orthographic knowledge. To this end, we had children from second to sixth grades learn novel written word forms using a repeated spelling practice paradigm. The speed at which children learned the word forms and their long-term retention (1week and 1month later) were assessed. Hierarchical regression analyses revealed that phonological recoding, preexisting word-specific orthographic knowledge, and order STM explained a portion of the variance in orthographic learning speed, whereas phonological recoding, preexisting word-specific orthographic knowledge, and orthographic sensitivity each explained a portion of variance in the long-term retention of the newly created orthographic representations. A secondary aim of the study was to determine the developmental trajectory of the abilities to acquire novel orthographic word forms over the course of primary schooling. As expected, results showed an effect of age on both learning speed and long-term retention. The specific roles of orthographic sensitivity and order STM as independent factors involved in different steps of orthographic learning are discussed. PMID:26600080

  5. Impaired long-term memory retention and working memory in sdy mutant mice with a deletion in Dtnbp1, a susceptibility gene for schizophrenia

    Directory of Open Access Journals (Sweden)

    Takao Keizo

    2008-10-01

    Full Text Available Abstract Background Schizophrenia is a complex genetic disorder caused by multiple genetic and environmental factors. The dystrobrevin-binding protein 1 (DTNBP1: dysbindin-1 gene is a major susceptibility gene for schizophrenia. Genetic variations in DTNBP1 are associated with cognitive functions, general cognitive ability and memory function, and clinical features of patients with schizophrenia including negative symptoms and cognitive decline. Since reduced expression of dysbindin-1 has been observed in postmortem brains of patients with schizophrenia, the sandy (sdy mouse, which has a deletion in the Dtnbp1 gene and expresses no dysbindin-1 protein, could be an animal model of schizophrenia. To address this issue, we have carried out a comprehensive behavioral analysis of the sdy mouse in this study. Results In a rotarod test, sdy mice did not exhibit motor learning whilst the wild type mice did. In a Barnes circular maze test both sdy mice and wild type mice learned to selectively locate the escape hole during the course of the training period and in the probe trial conducted 24 hours after last training. However, sdy mice did not locate the correct hole in the retention probe tests 7 days after the last training trial, whereas wild type mice did, indicating impaired long-term memory retention. A T-maze forced alternation task, a task of working memory, revealed no effect of training in sdy mice despite the obvious effect of training in wild type mice, suggesting a working memory deficit. Conclusion Sdy mouse showed impaired long-term memory retention and working memory. Since genetic variation in DTNBP1 is associated with both schizophrenia and memory function, and memory function is compromised in patients with schizophrenia, the sdy mouse may represent a useful animal model to investigate the mechanisms of memory dysfunction in the disorder.

  6. 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.)

  7. Despair-associated memory requires a slow-onset CA1 long-term potentiation with unique underlying mechanisms

    Science.gov (United States)

    Jing, Liang; Duan, Ting-Ting; Tian, Meng; Yuan, Qiang; Tan, Ji-Wei; Zhu, Yong-Yong; Ding, Ze-Yang; Cao, Jun; Yang, Yue-Xiong; Zhang, Xia; Mao, Rong-Rong; Richter-levin, Gal; Zhou, Qi-Xin; Xu, Lin

    2015-01-01

    The emotion of despair that occurs with uncontrollable stressful event is probably retained by memory, termed despair-associated memory, although little is known about the underlying mechanisms. Here, we report that forced swimming (FS) with no hope to escape, but not hopefully escapable swimming (ES), enhances hippocampal ?-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)-dependent GluA1 Ser831 phosphorylation (S831-P), induces a slow-onset CA1 long-term potentiation (LTP) in freely moving rats and leads to increased test immobility 24-h later. Before FS application of the antagonists to block S831-P or N-methyl-D-aspartic acid receptor (NMDAR) or glucocorticoid receptor (GR) disrupts LTP and reduces test immobility, to levels similar to those of the ES group. Because these mechanisms are specifically linked with the hopeless of escape from FS, we suggest that despair-associated memory occurs with an endogenous CA1 LTP that is intriguingly mediated by a unique combination of rapid S831-P with NMDAR and GR activation to shape subsequent behavioral despair. PMID:26449319

  8. Endogenous secreted amyloid precursor protein-alpha regulates hippocampal NMDA receptor function, long-term potentiation and spatial memory.

    Science.gov (United States)

    Taylor, Chanel J; Ireland, David R; Ballagh, Irene; Bourne, Katie; Marechal, Nicola M; Turner, Paul R; Bilkey, David K; Tate, Warren P; Abraham, Wickliffe C

    2008-08-01

    Secreted amyloid precursor protein-alpha (sAPP alpha) levels are reduced during the pathogenesis of Alzheimer's disease, but the significance of this for neural function is not well understood. Here, we show that intrahippocampal infusion of antibodies targeted to endogenous sAPP alpha reduced long-term potentiation (LTP) in the dentate gyrus of adult rats by approximately 50%. Conversely, infusion of recombinant sAPP alpha dose-dependently increased LTP and facilitated in vitro tetanically evoked NMDA receptor-mediated currents. Pharmacological inhibition of alpha-secretase and other a-disintegrin-and-metalloproteases by TAPI-1 reduced both LTP and tetanus-evoked NMDA receptor-mediated currents in dentate granule cells. Both effects were prevented by co-application of exogenous recombinant sAPP alpha. Similarly, spatial memory was inhibited by intrahippocampal TAPI-1, an effect that was prevented by co-application of recombinant sAPP alpha. Together these findings indicate that endogenous sAPP alpha is a key contributor to synaptic plasticity and spatial memory. Its reduced production in Alzheimer's disease may thus contribute to the clinical memory deficits. PMID:18585048

  9. Despair-associated memory requires a slow-onset CA1 long-term potentiation with unique underlying mechanisms.

    Science.gov (United States)

    Jing, Liang; Duan, Ting-Ting; Tian, Meng; Yuan, Qiang; Tan, Ji-Wei; Zhu, Yong-Yong; Ding, Ze-Yang; Cao, Jun; Yang, Yue-Xiong; Zhang, Xia; Mao, Rong-Rong; Richter-Levin, Gal; Zhou, Qi-Xin; Xu, Lin

    2015-01-01

    The emotion of despair that occurs with uncontrollable stressful event is probably retained by memory, termed despair-associated memory, although little is known about the underlying mechanisms. Here, we report that forced swimming (FS) with no hope to escape, but not hopefully escapable swimming (ES), enhances hippocampal ?-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)-dependent GluA1 Ser831 phosphorylation (S831-P), induces a slow-onset CA1 long-term potentiation (LTP) in freely moving rats and leads to increased test immobility 24-h later. Before FS application of the antagonists to block S831-P or N-methyl-D-aspartic acid receptor (NMDAR) or glucocorticoid receptor (GR) disrupts LTP and reduces test immobility, to levels similar to those of the ES group. Because these mechanisms are specifically linked with the hopeless of escape from FS, we suggest that despair-associated memory occurs with an endogenous CA1 LTP that is intriguingly mediated by a unique combination of rapid S831-P with NMDAR and GR activation to shape subsequent behavioral despair. PMID:26449319

  10. Weight Cycling Practices and Long-term Health Conditions in a Sample of Former Wrestlers and Other Collegiate Athletes

    OpenAIRE

    Nitzke, Susan A; Voichick, S. Jane; Olson, Diane

    1992-01-01

    Weight cycling (repeated episodes of weight loss and regain) has been shown to reduce the resting metabolic rate in some chronic dieters. Concerns have been raised that wrestlers' repeated patterns of weight loss and gain may reduce metabolic rates and increase long-term health risks. We conducted this study to assess previous weight loss practices, current body weight, and incidence of chronic disease in a sample of male athletes who earned athletic letters in intercollegiate sports at the U...

  11. Differential Roles for "Nr4a1" and "Nr4a2" in Object Location vs. Object Recognition Long-Term Memory

    Science.gov (United States)

    McNulty, Susan E.; Barrett, Ruth M.; Vogel-Ciernia, Annie; Malvaez, Melissa; Hernandez, Nicole; Davatolhagh, M. Felicia; Matheos, Dina P.; Schiffman, Aaron; Wood, Marcelo A.

    2012-01-01

    "Nr4a1" and "Nr4a2" are transcription factors and immediate early genes belonging to the nuclear receptor Nr4a family. In this study, we examine their role in long-term memory formation for object location and object recognition. Using siRNA to block expression of either "Nr4a1" or "Nr4a2", we found that "Nr4a2" is necessary for both long-term

  12. Participation of the classical speech areas in auditory long-term memory.

    Science.gov (United States)

    Karabanov, Anke Ninija; Paine, Rainer; Chao, Chi Chao; Schulze, Katrin; Scott, Brian; Hallett, Mark; Mishkin, Mortimer

    2015-01-01

    Accumulating evidence suggests that storing speech sounds requires transposing rapidly fluctuating sound waves into more easily encoded oromotor sequences. If so, then the classical speech areas in the caudalmost portion of the temporal gyrus (pSTG) and in the inferior frontal gyrus (IFG) may be critical for performing this acoustic-oromotor transposition. We tested this proposal by applying repetitive transcranial magnetic stimulation (rTMS) to each of these left-hemisphere loci, as well as to a nonspeech locus, while participants listened to pseudowords. After 5 minutes these stimuli were re-presented together with new ones in a recognition test. Compared to control-site stimulation, pSTG stimulation produced a highly significant increase in recognition error rate, without affecting reaction time. By contrast, IFG stimulation led only to a weak, non-significant, trend toward recognition memory impairment. Importantly, the impairment after pSTG stimulation was not due to interference with perception, since the same stimulation failed to affect pseudoword discrimination examined with short interstimulus intervals. Our findings suggest that pSTG is essential for transforming speech sounds into stored motor plans for reproducing the sound. Whether or not the IFG also plays a role in speech-sound recognition could not be determined from the present results. PMID:25815813

  13. Can we throw information out of visual working memory and does this leave informational residue in long-term memory?

    OpenAIRE

    AshleighMonetteMaxcey; GeoffreyF.Woodman

    2014-01-01

    Can we entirely erase a temporary memory representation from mind? This question has been addressed in several recent studies that tested the specific hypothesis that a representation can be erased from visual working memory based on a cue that indicated that the representation was no longer necessary for the task. In addition to behavioral results that are consistent with the idea that we can throw information out of visual working memory, recent neurophysiological recordings support this pr...

  14. Delayed emergence of effects of memory-enhancing drugs: implications for the dynamics of long-term memory.

    OpenAIRE

    MONDADORI, C; Hengerer, B; Ducret, T; Borkowski, J

    1994-01-01

    Many theories of memory postulate that processing of information outlasts the learning situation and involves several different physiological substrates. If such physiologically distinct mechanisms or stages of memory do in fact exist, they should be differentially affected by particular experimental manipulations. Accordingly, a selective improvement of the processes underlying short-term memory should be detectable only while the information is encoded in the short-term mode, and a selectiv...

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

    Science.gov (United States)

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

    2014-11-01

    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

  16. Wnt-5a prevents A?-induced deficits in long-term potentiation and spatial memory in rats.

    Science.gov (United States)

    Zhang, Gui-Li; Zhang, Jun; Li, Shao-Feng; Lei, Liu; Xie, Hong-Yan; Deng, Fang; Feng, Jia-Chun; Qi, Jin-Shun

    2015-10-01

    Although the neurotoxicity of amyloid ? (A?) protein in Alzheimer's disease (AD) has been reported widely, the exact molecular mechanism underlying the A?-induced synaptic dysfunction and memory impairment remains largely unclear. Growing evidence indicates that wingless-type (Wnt) signaling plays an important role in neuronal development, synapse formation and synaptic plasticity. In the present study, we investigated the neuroprotective action of Wnt-5a against the synaptic damage and memory deficit induced by A?25-35 by using in vivo electrophysiological recording and Morris water maze (MWM) test. We found that intracerebroventricular (i.c.v.) injection of A?25-35 alone did not affect the baseline field excitatory postsynaptic potentials (fEPSPs) and the paired-pulse facilitation (PPF) in the hippocampal CA1 region of rats, but significantly suppressed high frequency stimulation (HFS) induced long-term potentiation (LTP); pretreatment with Wnt-5a prevented the A?25-35-induced suppression of hippocampal LTP in a dose-dependent manner; soluble Frizzled-related protein (sFRP), a specific Wnt antagonist, effectively attenuated the protective effects of Wnt-5a. In MWM test, A?25-35 alone significantly disrupted spatial learning and memory ability of rats, while pretreatment with Wnt-5a effectively prevented the impairments induced by A?25-35. These results in the present study demonstrated for the first time the neuroprotective effects of Wnt-5a against A?-induced in vivo synaptic plasticity impairment and memory disorder, suggesting that Wnt signaling pathway is one of the important targets of A? neurotoxicity and Wnt-5a might be used as one of the putative candidates for the therapeutic intervention of AD. PMID:26032671

  17. 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.)

  18. Molecular Mechanisms Underlying Formation of Long-Term Reward Memories and Extinction Memories in the Honeybee ("Apis Mellifera")

    Science.gov (United States)

    Eisenhardt, Dorothea

    2014-01-01

    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…

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

    Science.gov (United States)

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

    2011-01-01

    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…

  20. Differential roles for Nr4a1 and Nr4a2 in object location vs. object recognition long-term memory

    OpenAIRE

    McNulty, Susan E.; Barrett, Ruth M.; Vogel-Ciernia, Annie; Malvaez, Melissa; Hernandez, Nicole; Davatolhagh, M. Felicia; Matheos, Dina P; Schiffman, Aaron; Wood, Marcelo A.

    2012-01-01

    Nr4a1 and Nr4a2 are transcription factors and immediate early genes belonging to the nuclear receptor Nr4a family. In this study, we examine their role in long-term memory formation for object location and object recognition. Using siRNA to block expression of either Nr4a1 or Nr4a2, we found that Nr4a2 is necessary for both long-term memory for object location and object recognition. In contrast, Nr4a1 appears to be necessary only for object location. Indeed, their roles in these different ty...

  1. Ganzfeld stimulation or sleep enhance long term motor memory consolidation compared to normal viewing in saccadic adaptation paradigm.

    Science.gov (United States)

    Voges, Caroline; Helmchen, Christoph; Heide, Wolfgang; Sprenger, Andreas

    2015-01-01

    Adaptation of saccade amplitude in response to intra-saccadic target displacement is a type of implicit motor learning which is required to compensate for physiological changes in saccade performance. Once established trials without intra-saccadic target displacement lead to de-adaptation or extinction, which has been attributed either to extra-retinal mechanisms of spatial constancy or to the influence of the stable visual surroundings. Therefore we investigated whether visual deprivation ("Ganzfeld"-stimulation or sleep) can partially maintain this motor learning compared to free viewing of the natural surroundings. Thirty-five healthy volunteers performed two adaptation blocks of 100 inward adaptation trials - interspersed by an extinction block - which were followed by a two-hour break with or without visual deprivation (VD). Using additional adaptation and extinction blocks short and long (4 weeks) term memory of this implicit motor learning were tested. In the short term, motor memory tested immediately after free viewing was superior to adaptation performance after VD. In the long run, however, effects were opposite: motor memory and relearning of adaptation was superior in the VD conditions. This could imply independent mechanisms that underlie the short-term ability of retrieving learned saccadic gain and its long term consolidation. We suggest that subjects mainly rely on visual cues (i.e., retinal error) in the free viewing condition which makes them prone to changes of the visual stimulus in the extinction block. This indicates the role of a stable visual array for resetting adapted saccade amplitudes. In contrast, visual deprivation (GS and sleep), might train subjects to rely on extra-retinal cues, e.g., efference copy or prediction to remap their internal representations of saccade targets, thus leading to better consolidation of saccadic adaptation. PMID:25867186

  2. Understanding the neurobiological mechanisms of learning and memory: Memory systems of the brain, long term potentiation and synaptic...

    Directory of Open Access Journals (Sweden)

    Philippe Leff

    2002-01-01

    Full Text Available El fenómeno de LTP es una forma de plasticidad sináptica ampliamente aceptado como un modelo de estabilización de sinapsis en procesos neurobiológicos como el desarrollo del SNC y el fenómeno de aprendizaje y memoria. Desde su descubrimiento por Bliss y Lomo (1973, el fenómeno de potenciación a largo plazo (PLP o LTP (Long-Term Potentiation, por sus siglas en inglés ha sido definido convencionalmente como la estimulación aferente de alta frecuencia que es capaz de despolarizar la célula postsináptica, a través de la activación de receptores glutamaérgicos, con la resultante entrada de calcio a la neurona postsináptica. Este evento neurobiológico produce un incremento intracelular en la concentración de calcio [(Cai] que induce la activación de diferentes sistemas moleculares de señalamiento intracelular (AMPc, proteínas cinasas, fosforilación de proteínas intracelulares que conlleva a una alteración de la actividad postsináptica y/o presináptica, dando por resultado un persistente incremento de respuesta sináptica específica dependiente de la activación del receptor glutamaérgico NMDA...

  3. Integration of Metagenomic and Biogeochemical Data from Soils Sampled from a Long-Term Reciprocal Transplant

    Science.gov (United States)

    Bailey, V. L.; Hess, N. J.; McCue, L. A.

    2014-12-01

    The long-term impacts of climate conditions on soil ecosystems are difficult to discern with sufficient resolution to underpin a predictive understanding of ecosystem response to global climate change. The structure and function of the microbial community is intimately linked to soil organic carbon (SOC) by both the deposition of new carbon, and metabolism and respiration of existing SOC. We are studying the resilience of the microbial community, and the vulnerability of the soil carbon reservoirs, to changing climate conditions using a reciprocal soil transplant experiment initiated in 1994 in eastern Washington. Soil cores were reciprocally transplanted between two elevations (310 m and 844 m); the lower site is warmer and drier with 0.8% soil carbon, and the upper site is cooler and wetter with 1.8% soil carbon. We resampled these cores in 2012-13 to analyze the structure of the microbial community, biochemical activities of carbohydrate-active enzymes, and the soil carbon and nitrogen content. We hypothesized that microbial and biochemical dynamics developed under cool, moist conditions would destabilize under hot, dry conditions, such that carbon and nitrogen losses would be faster in warmer climate soils than the accruals in cooler climate soils. Metagenomics data analyses show that the microbial communities below 5 cm depth in the transplanted soils are most similar to those in the native and control soils from their original (pre-1994) location, whereas the surface microbial community has been influenced by their new (post-1994) location. Enzyme activities are highest in soils from the cooler, moister location, and the activities of the reciprocally transplanted soils are shifting toward the activities typical of their new location. Integration of these results with high-resolution mass spectrometry data of the soil carbon moieties will contribute to our fundamental understanding of climate change effects on the terrestrial ecosystem carbon cycle.

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

    DEFF Research Database (Denmark)

    Nielsen, Andreas HØjlund; Gebauer, Line

    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.

  5. Unconventional cytokine profiles and development of T cell memory in long-term survivors after cancer vaccination

    DEFF Research Database (Denmark)

    Kyte, Jon Amund; Trachsel, Sissel; Risberg, Bente; thor Straten, Per; Lislerud, Kari; Gaudernack, Gustav

    2009-01-01

    Cancer vaccine trials frequently report on immunological responses, without any clinical benefit. This paradox may reflect the challenge of discriminating between effective and pointless immune responses and sparse knowledge on their long-term development. Here, we have analyzed T cell responses in long-term survivors after peptide vaccination. There were three main study aims: (1) to characterize the immune response in patients with a possible clinical benefit. (2) To analyze the long-term deve...

  6. Facilitative Effects of Forgetting from Short-Term Memory on Growth of Long-Term Memory in Retardates

    Science.gov (United States)

    Sperber, Richard D.

    1976-01-01

    Competing explanations of the beneficial effect of spacing in retardate discrimination learning were tested. Results are inconsistent with consolidation and rehearsal theories but support the prediction of the Geber, Greenfield, and House spacing model that forgetting from short-term memory facilities retardate learning. (Author/SB)

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

    LENUS (Irish Health Repository)

    Mitchell, Jacqueline C

    2009-12-01

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

  8. Distractibility during Retrieval of Long-Term Memory: Domain-General Interference, Neural Networks and Increased Susceptibility in Normal Aging

    Directory of Open Access Journals (Sweden)

    PeterEdwardWais

    2014-04-01

    Full Text Available The mere presence of irrelevant external stimuli results in interference with the fidelity of details retrieved from long-term memory (LTM. Recent studies suggest that distractibility during LTM retrieval occurs when the focus of resource-limited, top-down mechanisms that guide the selection of relevant mnemonic details is disrupted by representations of external distractors. We review findings from four studies that reveal distractibility during episodic retrieval. The approach cued participants to recall previously studied visual details when their eyes were closed, or were open and irrelevant visual information was present. The results showed a negative impact of the distractors on the fidelity of details retrieved from LTM. An fMRI experiment using the same paradigm replicated the behavioral results and found that diminished episodic memory was associated with the disruption of functional connectivity in whole-brain networks. Specifically, network connectivity supported recollection of details based on visual imagery when eyes were closed, but connectivity declined in the presence of visual distractors. Another experiment using auditory distractors found equivalent effects for auditory and visual distraction during cued recall, suggesting that the negative impact of distractibility is a domain-general phenomenon in LTM. Comparisons between older and younger adults revealed an aging-related increase in the negative impact of distractibility on retrieval of LTM. Finally, a new study that compared categorization abilities between younger and older adults suggests a cause underlying age-related decline of visual details in LTM. The sum of our findings suggests that cognitive control resources, although limited, have the capability to resolve interference from distractors during tasks of moderate effort, but these resources are overwhelmed when additional processes associated with episodic retrieval, or categorization of complex prototypes, are required.

  9. Mapping of total scattering as a tool for long term investigations in the cleaning state of the functional coated samples

    Science.gov (United States)

    Kadkhoda, P.; Günster, S.; Jensen, L.; Ristau, D.

    2014-11-01

    In optical coating production the generation of particles and defects is always an undesirable side effect and cannot be completely avoided in the handling steps of the optical components. Particles and defects on the substrates and in the functional coatings lead to scattering and absorption, which may cause a lower damage threshold for components of high power laser application. In this study, results of a long term investigation in the quality and the state of the cleanliness of multilayer systems produced by different deposition techniques are presented. Coated samples of different coating processes are investigated with the help of a Fast Total Scatter scanning system. Adapted data reduction algorithms for the determination of the particle sizes derived from the scattering measurements are developed and applied to the measurement results. On this basis, the density distribution of particle contamination on the samples is evaluated for selected coating runs over a long term period. The calculated statistics of the samples are related to the corresponding production conditions of individual coating plants to extract specific effects of the process environment.

  10. 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

    Directory of Open Access Journals (Sweden)

    Stan Klein

    2013-02-01

    Full Text Available 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 (a the core features assumed unique to episodic memory are shared by semantic memory, (b 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 (c 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.

  11. Protein Synthesis-Dependent Long-Term Memory Induced by One Single Associative Training Trial in the Parasitic Wasp Lariophagus distinguendus

    Science.gov (United States)

    Steidle, Johannes L. M.; Collatz, Jana; Muller, Caroline

    2006-01-01

    Protein synthesis-dependent long-term memory in Apis mellifera and Drosophila melanogaster is formed after multiple trainings that are spaced in time. The parasitic wasp Lariophagus distinguendus remarkably differs from these species. It significantly responds to the artificial odor furfurylheptanoate (FFH) in olfactometer experiments, when this…

  12. Sampling design for long-term regional trends in marine rocky intertidal communities

    Science.gov (United States)

    Irvine, Gail V.; Shelley, Alice

    2013-01-01

    Probability-based designs reduce bias and allow inference of results to the pool of sites from which they were chosen. We developed and tested probability-based designs for monitoring marine rocky intertidal assemblages at Glacier Bay National Park and Preserve (GLBA), Alaska. A multilevel design was used that varied in scale and inference. The levels included aerial surveys, extensive sampling of 25 sites, and more intensive sampling of 6 sites. Aerial surveys of a subset of intertidal habitat indicated that the original target habitat of bedrock-dominated sites with slope ?30° was rare. This unexpected finding illustrated one value of probability-based surveys and led to a shift in the target habitat type to include steeper, more mixed rocky habitat. Subsequently, we evaluated the statistical power of different sampling methods and sampling strategies to detect changes in the abundances of the predominant sessile intertidal taxa: barnacles Balanomorpha, the mussel Mytilus trossulus, and the rockweed Fucus distichus subsp. evanescens. There was greatest power to detect trends in Mytilus and lesser power for barnacles and Fucus. Because of its greater power, the extensive, coarse-grained sampling scheme was adopted in subsequent years over the intensive, fine-grained scheme. The sampling attributes that had the largest effects on power included sampling of “vertical” line transects (vs. horizontal line transects or quadrats) and increasing the number of sites. We also evaluated the power of several management-set parameters. Given equal sampling effort, sampling more sites fewer times had greater power. The information gained through intertidal monitoring is likely to be useful in assessing changes due to climate, including ocean acidification; invasive species; trampling effects; and oil spills.

  13. Evidence for large long-term memory capacities in baboons and pigeons and its implications for learning and the evolution of cognition

    OpenAIRE

    Fagot, Joël; Cook, Robert G.

    2006-01-01

    Previous research has shown that birds and primates have a rich repertoire of behavioral and cognitive skills, but the mechanisms underlying these abilities are not well understood. A common hypothesis is that these adaptations are mediated by an efficient long-term memory, allowing animals to remember specific external events and associate appropriate behaviors to these events. Because earlier studies have not sufficiently challenged memory capacity in animals, our comparative research exami...

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

    Science.gov (United States)

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

    2013-01-01

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

  15. Long-term storage of salivary cortisol samples at room temperature

    Science.gov (United States)

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

    1992-01-01

    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.

  16. 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)

    Mohammad Karami

    2013-12-01

    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.

  17. 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)

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

    2012-01-01

    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…

  18. Intimate Partner Violence and Long-Term Psychosocial Functioning in a National Sample of American Women

    Science.gov (United States)

    Zlotnick, Caron; Johnson, Dawn M.; Kohn, Robert

    2006-01-01

    Using a nationally representative sample of American married or cohabiting women, this prospective study examined women who reported or denied intimate partner violence (IPV) at wave 1 and compared them on a range of psychosocial outcomes at a 5-year follow-up. This study also examined the rate of divorce or separation during the 5-year interval…

  19. Long-term room temperature preservation of corpse soft tissue: an approach for tissue sample storage

    OpenAIRE

    Caputo Mariela; Bosio Luis A; Corach Daniel

    2011-01-01

    Abstract Background Disaster victim identification (DVI) represents one of the most difficult challenges in forensic sciences, and subsequent DNA typing is essential. Collected samples for DNA-based human identification are usually stored at low temperature to halt the degradation processes of human remains. We have developed a simple and reliable procedure for soft tissue storage and preservation for DNA extraction. It ensures high quality DNA suitable for PCR-based DNA typing after at least...

  20. Long-term room temperature preservation of corpse soft tissue: an approach for tissue sample storage

    Directory of Open Access Journals (Sweden)

    Caputo Mariela

    2011-08-01

    Full Text Available Abstract Background Disaster victim identification (DVI represents one of the most difficult challenges in forensic sciences, and subsequent DNA typing is essential. Collected samples for DNA-based human identification are usually stored at low temperature to halt the degradation processes of human remains. We have developed a simple and reliable procedure for soft tissue storage and preservation for DNA extraction. It ensures high quality DNA suitable for PCR-based DNA typing after at least 1 year of room temperature storage. Methods Fragments of human psoas muscle were exposed to three different environmental conditions for diverse time periods at room temperature. Storage conditions included: (a a preserving medium consisting of solid sodium chloride (salt, (b no additional substances and (c garden soil. DNA was extracted with proteinase K/SDS followed by organic solvent treatment and concentration by centrifugal filter devices. Quantification was carried out by real-time PCR using commercial kits. Short tandem repeat (STR typing profiles were analysed with 'expert software'. Results DNA quantities recovered from samples stored in salt were similar up to the complete storage time and underscored the effectiveness of the preservation method. It was possible to reliably and accurately type different genetic systems including autosomal STRs and mitochondrial and Y-chromosome haplogroups. Autosomal STR typing quality was evaluated by expert software, denoting high quality profiles from DNA samples obtained from corpse tissue stored in salt for up to 365 days. Conclusions The procedure proposed herein is a cost efficient alternative for storage of human remains in challenging environmental areas, such as mass disaster locations, mass graves and exhumations. This technique should be considered as an additional method for sample storage when preservation of DNA integrity is required for PCR-based DNA typing.

  1. Long term observations of materials deposited on wall samples in ASDEX

    International Nuclear Information System (INIS)

    Protective glasses are mounted inside the vacuum vessel in front of the observation windows used for Hsub(?)-measurements. These glass discs are positioned near the wall surface and are routinely replaced at each major opening of the vessel, namely after several months of operation of ASDEX. Comprehensive surface analyses are performed using a scanning electron microscope combined with Auger, SIMS and X-ray microanalysis techniques. The lateral as well as the depth distributions of deposited materials are measured. The observations based on large number of samples (about 30) distributed all over the vacuum vessel, are the following: - deposits in the main plasma chamber consist of thin layers of stainless steel (i.e. Fe, Cr, Ni) and of titanium. These layers are completely oxidized and have been successively deposited during the major phases of the machine operation (limiter, divertor, titanium gettering). Many stainless-steel particles are observed. These are molten droplets projected and stuck on the glass surface. Their dimensions range from a few ?m to about 100 ?m. Very tiny titanium particles are also observed spread over the surface. - Deposits on samples exposed in the upper divertor chamber are covered with a uniform titanium layer. It is heavily oxidized over its thickness of approx. equal to 10 nm. No droplets are observed in the upper divertor chamber, but many are found in the lower chamber. (orig.)

  2. Protective long-term antibody memory by antigen-driven and T help-dependent differentiation of long-lived memory B cells to short-lived plasma cells independent of secondary lymphoid organs

    OpenAIRE

    Ochsenbein, Adrian F.; Pinschewer, Daniel D; Sierro, Sophie; Horvath, Edit; Hengartner, Hans; Zinkernagel, Rolf M.

    2000-01-01

    Memory is a hallmark of immunity. Memory carried by antibodies is largely responsible for protection against reinfection with most known acutely lethal infectious agents and is the basis for most clinically successful vaccines. However, the nature of long-term B cell and antibody memory is still unclear. B cell memory was studied here after infection of mice with the rabies-like cytopathic vesicular stomatitis virus, the noncytopathic lymphocytic choriomeningitis virus...

  3. 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)

    Parisa Hasanein

    2010-04-01

    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.

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

    DEFF Research Database (Denmark)

    Demant, Helle; Ladewig, Jan

    2011-01-01

    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.

  5. Genetic Disruption of Protein Kinase A Anchoring Reveals a Role for Compartmentalized Kinase Signaling in Theta-Burst Long-Term Potentiation and Spatial Memory

    OpenAIRE

    Nie, Ting; McDonough, Conor B.; Huang, Ted; Nguyen, Peter V; Abel, Ted

    2007-01-01

    Studies of hippocampal long-term potentiation (LTP), a cellular model of memory storage, implicate cAMP-dependent protein kinase (PKA) in presynaptic and postsynaptic mechanisms of LTP. The anchoring of PKA to AKAPs (A kinase-anchoring proteins) creates compartmentalized pools of PKA, but the roles of presynaptically and postsynaptically anchored forms of PKA in late-phase LTP are unclear. In this study, we have created genetically modified mice that conditionally express Ht31, an inhibitor o...

  6. Redintegration and the benefits of long-term knowledge in verbal short-term memory: an evaluation of Schweickert's (1993) multinomial processing tree model.

    Science.gov (United States)

    Thorn, Annabel S C; Gathercole, Susan E; Frankish, Clive R

    2005-03-01

    The impact of four long-term knowledge variables on serial recall accuracy was investigated. Serial recall was tested for high and low frequency words and high and low phonotactic frequency nonwords in 2 groups: monolingual English speakers and French-English bilinguals. For both groups the recall advantage for words over nonwords reflected more fully correct recalls with fewer recall attempts that consisted of fragments of the target memory items (one or two of the three target phonemes recalled correctly); completely incorrect recalls were equivalent for the 2 list types. However, word frequency (for both groups), nonword phonotactic frequency (for the monolingual group), and language familiarity all influenced the proportions of completely incorrect recalls that were made. These results are not consistent with the view that long-term knowledge influences on immediate recall accuracy can be exclusively attributed to a redintegration process of the type specified in multinomial processing tree model of immediate recall. The finding of a differential influence on completely incorrect recalls of these four long-term knowledge variables suggests instead that the beneficial effects of long-term knowledge on short-term recall accuracy are mediated by more than one mechanism. PMID:15680142

  7. 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

    Science.gov (United States)

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

    2014-01-01

    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)…

  8. 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

    Scientific Electronic Library Online (English)

    PABLO, ESPINA-MARCHANT; TERESA, PINTO-HAMUY; DIEGO, BUSTAMANTE; PAOLA, MORALES; LUIS, ROBLES; MARIO, HERRERA-MARSCHITZ.

    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 stra [...] tegy, 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

  9. 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

    Directory of Open Access Journals (Sweden)

    PABLO ESPINA-MARCHANT

    2006-01-01

    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

  10. Memory deficits in long-term survivors of childhood brain tumors may primarily reflect general cognitive dysfunctions

    DEFF Research Database (Denmark)

    Reimers, Tonny Solveig; Mortensen, Erik Lykke; Schmiegelow, Kjeld

    2007-01-01

    To analyze the impact of potential predictors on memory performance in survivors of childhood brain tumors and to examine whether deficits in memory after radiotherapy (RT) should be considered part of a more global mental dysfunction.

  11. Long-term memory in Aplysia modulates the total number of varicosities of single identified sensory neurons.

    OpenAIRE

    Bailey, C H; Chen, M.

    1988-01-01

    The morphological consequences of long-term habituation and sensitization of the gill withdrawal reflex in Aplysia california were explored by examining the total number of presynaptic varicosities of single identified sensory neurons (a critical site of plasticity for the biochemical and biophysical changes that underlie both types of learning) in control and behaviorally trained animals. Sensory neurons from habituated animals had 35% fewer synaptic varicosities than did sensory neurons fro...

  12. KAOLIN-INDUCED VENTRICULOMEGALY AT WEANING PRODUCES LONG-TERM LEARNING, MEMORY, AND MOTOR DEFICITS IN RATS

    OpenAIRE

    Williams, Michael T; Braun, Amanda A.; Amos-Kroohs, Robyn; McAllister, James P; Lindquist, Diana M.; Mangano, Francesco T; Vorhees, Charles V; Yuan, Weihong

    2014-01-01

    Ventriculomegaly occurs when there is imbalance between creation and absorption of cerebrospinal fluid (CSF); even when treated, long-term behavioral changes occur. Kaolin injection in the cisterna magna of rats produces an obstruction of CSF outflow and models one type of hydrocephalus. Previous research with this model shows that neonatal onset has mixed effects on Morris water maze (MWM) and motoric performance; we hypothesized that this might be because the severity of ventricular enlarge...

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

    Directory of Open Access Journals (Sweden)

    Alireza Sarkaki

    2013-09-01

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

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

    OpenAIRE

    Ingelman-Sundberg, Hanna M.

    2015-01-01

    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...

  15. Forebrain NR2B Overexpression Facilitating the Prefrontal Cortex Long-Term Potentiation and Enhancing Working Memory Function in Mice

    OpenAIRE

    Cui, Yihui; Jin, Jing; Zhang, Xuliang; Xu, Hao(School of Physics, Nankai University, 300071, Tianjin, People’s Republic of China); Yang, Liguo; Du, Dan; Zeng, Qingwen; Tsien, Joe Z.; Yu, Huiting; Cao, Xiaohua

    2011-01-01

    Prefrontal cortex plays an important role in working memory, attention regulation and behavioral inhibition. Its functions are associated with NMDA receptors. However, there is little information regarding the roles of NMDA receptor NR2B subunit in prefrontal cortical synaptic plasticity and prefrontal cortex-related working memory. Whether the up-regulation of NR2B subunit influences prefrontal cortical synaptic plasticity and working memory is not yet clear. In the present study, we measure...

  16. Relative Ease in Creating Detailed Orthographic Representations Contrasted with Severe Difficulties to Maintain Them in Long-term Memory Among Dyslexic Children.

    Science.gov (United States)

    Binamé, Florence; Danzio, Sophie; Poncelet, Martine

    2015-11-01

    Most research into orthographic learning abilities has been conducted in English with typically developing children using reading-based tasks. In the present study, we examined the abilities of French-speaking children with dyslexia to create novel orthographic representations for subsequent use in spelling and to maintain them in long-term memory. Their performance was compared with that of chronological age (CA)-matched and reading age (RA)-matched control children. We used an experimental task designed to provide optimal learning conditions (i.e. 10 spelling practice trials) ensuring the short-term acquisition of the spelling of the target orthographic word forms. After a 1-week delay, the long-term retention of the targets was assessed by a spelling post-test. Analysis of the results revealed that, in the short term, children with dyslexia learned the novel orthographic word forms well, only differing from both CA and RA controls on the initial decoding of the targets and from CA controls on the first two practice trials. In contrast, a dramatic drop was observed in their long-term retention relative to CA and RA controls. These results support the suggestion of the self-teaching hypothesis (Share, 1995) that initial errors in the decoding and spelling of unfamiliar words may hinder the establishment of fully specified novel orthographic representations. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26358745

  17. Application of Long-term cultured Interferon-? Enzyme-linked Immunospot Assay for Assessing Effector and Memory T Cell Responses in Cattle.

    Science.gov (United States)

    Maggioli, Mayara F; Palmer, Mitchell V; Vordermeier, H Martin; Whelan, Adam O; Fosse, James M; Nonnecke, Brian J; Waters, W Ray

    2015-01-01

    Effector and memory T cells are generated through developmental programing of naïve cells following antigen recognition. If the infection is controlled up to 95 % of the T cells generated during the expansion phase are eliminated (i.e., contraction phase) and memory T cells remain, sometimes for a lifetime. In humans, two functionally distinct subsets of memory T cells have been described based on the expression of lymph node homing receptors. Central memory T cells express C-C chemokine receptor 7 and CD45RO and are mainly located in T-cell areas of secondary lymphoid organs. Effector memory T cells express CD45RO, lack CCR7 and display receptors associated with lymphocyte homing to peripheral or inflamed tissues. Effector T cells do not express either CCR7 or CD45RO but upon encounter with antigen produce effector cytokines, such as interferon-?. Interferon-? release assays are used for the diagnosis of bovine and human tuberculosis and detect primarily effector and effector memory T cell responses. Central memory T cell responses by CD4(+) T cells to vaccination, on the other hand, may be used to predict vaccine efficacy, as demonstrated with simian immunodeficiency virus infection of non-human primates, tuberculosis in mice, and malaria in humans. Several studies with mice and humans as well as unpublished data on cattle, have demonstrated that interferon-? ELISPOT assays measure central memory T cell responses. With this assay, peripheral blood mononuclear cells are cultured in decreasing concentration of antigen for 10 to 14 days (long-term culture), allowing effector responses to peak and wane; facilitating central memory T cells to differentiate and expand within the culture. PMID:26275095

  18. 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)

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

    2015-03-01

    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

  19. 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)

    L Imberti

    2012-11-01

    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.

  20. The Effect of Synchronized Forced Running with Chronic Stress on Short, Mid and Long- term Memory in Rats

    OpenAIRE

    Maryam Radahmadi; Hojjatallah Alaei; Mohammad Reza Sharifi; Nasrin Hosseini

    2012-01-01

    Purpose: Impairment of learning and memory processes has been demonstrated by many studies using different stressors. Other reports suggested that exercise has a powerful behavioral intervention to improve cognitive function and brain health. In this research, we investigated protective effects of treadmill running on chronic stress–induced memory deficit in rats.Methods: Fifty male Wistar rats were randomly divided into five groups (n=10) as follows: Control (Co), Sham (Sh), Stress (St), Exe...

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

    Directory of Open Access Journals (Sweden)

    Thomas Simon

    2012-01-01

    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.

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

    Scientific Electronic Library Online (English)

    Thomas, Simon; Séverine, Tanguy-Royer; Pierre-Joseph, Royer; Nicolas, Boisgerault; Jihane, Frikeche; Jean-François, Fonteneau; Marc, Grégoire.

    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 init [...] iate 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.

  3. Reversal of Impaired Hippocampal Long-term Potentiation and Contextual Fear Memory Deficits in Angelman Syndrome Model Mice by ErbB Inhibitors

    Science.gov (United States)

    Kaphzan, Hanoch; Hernandez, Pepe; Jung, Joo In; Cowansage, Kiriana K.; Deinhardt, Katrin; Chao, Moses V.; Abel, Ted; Klann, Eric

    2012-01-01

    Background Angelman syndrome (AS) is a human neuropsychiatric disorder associated with autism, mental retardation, motor abnormalities, and epilepsy. In most cases, AS is caused by the deletion of the maternal copy of UBE3A gene, which encodes the enzyme ubiquitin ligase E3A, also termed E6-AP. A mouse model of AS has been generated and these mice exhibit many of the observed neurological alterations in humans. Because of clinical and neuroanatomical similarities between AS and schizophrenia, we examined AS model mice for alterations in the neuregulin-ErbB4 pathway, which has been implicated in the pathophysiology of schizophrenia. We focused our studies on the hippocampus, one of the major brain loci impaired in AS mice. Methods We determined the expression of NRG1 and ErbB4 receptors in AS mice and wild-type littermates (ages 10-16 weeks), and studied the effects of ErbB inhibition on long-term potentiation (LTP) in hippocampal area CA1 and on hippocampus-dependent contextual fear memory. Results We observed enhanced neuregulin-ErbB4 signaling in the hippocampus of AS model mice and found that ErbB inhibitors could reverse deficits in LTP, a cellular substrate for learning and memory. In addition, we found that an ErbB inhibitor enhanced long-term contextual fear memory in AS model mice. Conclusions Our findings suggest that neuregulin-ErbB4 signaling is involved in synaptic plasticity and memory impairments in AS model mice, suggesting that ErbB inhibitors have therapeutic potential for the treatment of AS. PMID:22381732

  4. 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 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.

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

    Science.gov (United States)

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

    2014-01-01

    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…

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

    Science.gov (United States)

    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

    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…

  7. Protective long-term antibody memory by antigen-driven and T help-dependent differentiation of long-lived memory B cells to short-lived plasma cells independent of secondary lymphoid organs.

    Science.gov (United States)

    Ochsenbein, A F; Pinschewer, D D; Sierro, S; Horvath, E; Hengartner, H; Zinkernagel, R M

    2000-11-21

    Memory is a hallmark of immunity. Memory carried by antibodies is largely responsible for protection against reinfection with most known acutely lethal infectious agents and is the basis for most clinically successful vaccines. However, the nature of long-term B cell and antibody memory is still unclear. B cell memory was studied here after infection of mice with the rabies-like cytopathic vesicular stomatitis virus, the noncytopathic lymphocytic choriomeningitis virus (Armstrong and WE), and after immunization with various inert viral antigens inducing naive B cells to differentiate either to plasma cells or memory B cells in germinal centers of secondary lymphoid organs. The results show that in contrast to very low background levels against internal viral antigens, no significant neutralizing antibody memory was observed in the absence of antigen and suggest that memory B cells (i) are long-lived in the absence of antigen, nondividing, and relatively resistant to irradiation, and (ii) must be stimulated by antigen to differentiate to short-lived antibody-secreting plasma cells, a process that is also efficient in the bone marrow and always depends on radiosensitive, specific T help. Therefore, for vaccines to induce long-term protective antibody titers, they need to repeatedly provide, or continuously maintain, antigen in minimal quantities over a prolonged time period in secondary lymphoid organs or the bone marrow for sufficient numbers of long-lived memory B cells to mature to short-lived plasma cells. PMID:11069289

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

    Science.gov (United States)

    Snow, Sarah Elizabeth

    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.

  9. Long-Term Care

    Science.gov (United States)

    ... this page please turn Javascript on. Long-Term Care What Is Long-Term Care? Long-term care involves a variety of services ... 8 sec Click to watch this video Most Care Provided at Home Click for more information Long- ...

  10. INTRA-HIPPOCAMPAL ADMINISTRATION OF THE VEGF RECEPTOR BLOCKER PTK787/ZK222584 IMPAIRS LONG-TERM MEMORY

    OpenAIRE

    Pati, Shibani; Orsi, Sara A.; Moore, Anthony N.; Dash, Pramod K.

    2008-01-01

    A number of studies have established a role for vascular endothelial growth factor (VEGF) in angiogenesis. Recent reports have shown that VEGF overexpression in the hippocampus improves learning and memory and is associated with enhanced neurogenesis. PTK787/ZK222584 (PTK/ZK) is a reported inhibitor of VEGFR signaling that is currently being tested for its effects on lung and colon cancer. However, the influence of this drug on cognition has not been examined. In the present study, we questio...

  11. Long-term sampling of CO2 from waste-to-energy plants: 14C determination methodology, data variation and uncertainty

    DEFF Research Database (Denmark)

    Fuglsang, Karsten; Pedersen, Niels Hald

    2014-01-01

    A dedicated sampling and measurement method was developed for long-term measurements of biogenic and fossil-derived CO2 from thermal waste-to-energy processes. Based on long-term sampling of CO2 and 14C determination, plant-specific emission factors can be determined more accurately, and the annual emission of fossil CO2 from waste-to-energy plants can be monitored according to carbon trading schemes and renewable energy certificates. Weekly and monthly measurements were performed at five Danish waste incinerators. Significant variations between fractions of biogenic CO2 emitted were observed, not only over time, but also between plants. From the results of monthly samples at one plant, the annual mean fraction of biogenic CO2 was found to be 69% of the total annual CO2 emissions. From weekly samples, taken every 3 months at the five plants, significant seasonal variations in biogenic CO2 emissions were observed (between 56% and 71% biogenic CO2). These variations confirmed that biomass fractions in the wastecan vary considerably, not only from day to day but also from month to month. An uncertainty budget for the measurement method itself showed that the expanded uncertainty of the method was ± 4.0 pmC (95 % confidence interval) at 62 pmC. The long-term sampling method was found to be useful for waste incinerators for determination of annual fossil and biogenic CO2 emissions with relatively low uncertainty.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  13. Long-term effects of neonatal exposure to MK-801 on recognition memory and excitatory-inhibitory balance in rat hippocampus.

    Science.gov (United States)

    Li, J-T; Zhao, Y-Y; Wang, H-L; Wang, X-D; Su, Y-A; Si, T-M

    2015-11-12

    Blockade of the N-methyl-d-aspartate receptors (NMDARs) during the neonatal period has been reported to induce long-term behavioral and neurochemical alterations that are relevant to schizophrenia. In this study, we examined the effects of such treatment on recognition memory and hippocampal excitatory and inhibitory (E/I) balance in both adolescence and adulthood. After exposure to the NMDAR antagonist, MK-801, at postnatal days (PND) 5-14, male Sprague-Dawley rats were tested for object and object-in-context recognition memory during adolescence (PND 35) and adulthood (PND 63). The parvalbumin-positive (PV+) ?-aminobutyric acid (GABA)-ergic interneurons and presynaptic markers for excitatory and inhibitory neurons, vesicular glutamate transporter-1 (VGLUT1) and vesicular GABA transporter (VGAT) were examined in the hippocampus to reflect the E/I balance. We found that rats receiving MK-801 treatment showed deficits of recognition memory, reduction in PV+ cell counts and upregulation of the VGLUT1/VGAT ratio in both adolescence and adulthood. Notably, the changes of the VGLUT1/VGAT ratio at the two time points exhibited distinct mechanisms. These results parallel findings of hippocampal abnormalities in schizophrenia and lend support to the usefulness of neonatal NMDAR blockade as a potential neurodevelopmental model for the disease. PMID:26349007

  14. Single fluoxetine treatment before but not after stress prevents stress-induced hippocampal long-term depression and spatial memory retrieval impairment in rats.

    Science.gov (United States)

    Han, Huili; Dai, Chunfang; Dong, Zhifang

    2015-01-01

    A growing body of evidence has shown that chronic treatment with fluoxetine, a widely prescribed medication for treatment of depression, can affect synaptic plasticity in the adult central nervous system. However, it is not well understood whether acute fluoxetine influences synaptic plasticity, especially on hippocampal CA1 long-term depression (LTD), and if so, whether it subsequently impacts hippocampal-dependent spatial memory. Here, we reported that LTD facilitated by elevated-platform stress in hippocampal slices was completely prevented by fluoxetine administration (10?mg/kg, i.p.) 30?min before stress. The LTD was not, however, significantly inhibited by fluoxetine administration immediately after stress. Similarly, fluoxetine incubation (10??M) during electrophysiological recordings also displayed no influence on the stress-facilitated LTD. In addition, behavioral results showed that a single fluoxetine treatment 30?min before but not after acute stress fully reversed the impairment of spatial memory retrieval in the Morris water maze paradigm. Taken together, these results suggest that acute fluoxetine treatment only before, but not after stress, can prevent hippocampal CA1 LTD and spatial memory retrieval impairment caused by behavioral stress in adult animals. PMID:26218751

  15. Effect of long-term storage on hormone measurements in samples from pregnant women: The experience of the Finnish Maternity Cohort

    OpenAIRE

    Holl, Katsiaryna; Lundin, Eva; Kaasila, Marjo; Grankvist, Kjell; Afanasyeva, Yelena; Hallmans, Göran; Lehtinen, Matti; Pukkala, Eero; Surcel, Helja-Marja; Toniolo, Paolo; Zeleniuch-Jacquotte, Anne; Koskela, Pentti; Lukanova, Annekatrin

    2007-01-01

    Validity of biobank studies on hormone associated cancers depend on the extent the sample preservation is affecting the hormone measurements. We investigated the effect of long-term storage (up to 22 years) on immunoassay measurements of three groups of hormones and associated proteins: sex-steroids [estradiol, progesterone, testosterone, dihydroepiandrosterone sulphate (DHEAS), sex hormone-binding globulin (SHBG)], pregnancy-specific hormones [human chorionic gonadotropin (hCG), placental gr...

  16. Long-term exposure to low frequency electro-magnetic fields of 50- and 217-Hz leads to learning and memory deficits in mice

    Directory of Open Access Journals (Sweden)

    Soheila Khodakarim

    2012-01-01

    Full Text Available Electromagnetic field (EMF radiation affects cellular and brain chemistry and function, resulting in deleterious effects such as free radicals formation, impaired DNA repair, reduced melatonin and blood brain barrier protection, and defects on learning and memory and other higher brain functions. In this paper the effects of low frequency EMF of 50- and 217 Hz, ranges often associated with common electronic devices such as televisions and cell phones were examined on learning and memory in adult male mice. Five groups (n=10 mice/group of mice (1 control and 4 experimental were initially trained for the passive avoidance (PA test. They were then placed in devices creating EMF radiation with varying intensities (0.5 to 2 milli-Tesla, mT and frequencies (50- and 217-Hz for 2-weeks (16 hrs/day. Control mice received no radiation. Learning and memory was tested by the PA test and evaluated based on the following parameters: mean step through latency (STL, number of crossing (Cr# and time in dark compartment (TDC. Results showed significant deficiencies in learning and memory in the EM-exposed mice compared to controls: mean STL decreased significantly (p<0.001 in the 50 Hz group (1 and 1.5 mT intensities. In the 217 Hz group, STL also decreased in the 0.5 and 2 mT groups (p< 0.05. There was a notable increase in mean Cr# for both groups and TDC for 50 Hz group. Results confirm that long-term exposure to EMF radiation of 50 and 217 Hz, imparts significant harmful changes on memory and learning, reiterating the need for preventive measures against such exposures.

  17. Long-term resource variation and group size: A large-sample field test of the Resource Dispersion Hypothesis

    Directory of Open Access Journals (Sweden)

    Morecroft Michael D

    2001-07-01

    Full Text Available Abstract Background The Resource Dispersion Hypothesis (RDH proposes a mechanism for the passive formation of social groups where resources are dispersed, even in the absence of any benefits of group living per se. Despite supportive modelling, it lacks empirical testing. The RDH predicts that, rather than Territory Size (TS increasing monotonically with Group Size (GS to account for increasing metabolic needs, TS is constrained by the dispersion of resource patches, whereas GS is independently limited by their richness. We conducted multiple-year tests of these predictions using data from the long-term study of badgers Meles meles in Wytham Woods, England. The study has long failed to identify direct benefits from group living and, consequently, alternative explanations for their large group sizes have been sought. Results TS was not consistently related to resource dispersion, nor was GS consistently related to resource richness. Results differed according to data groupings and whether territories were mapped using minimum convex polygons or traditional methods. Habitats differed significantly in resource availability, but there was also evidence that food resources may be spatially aggregated within habitat types as well as between them. Conclusions This is, we believe, the largest ever test of the RDH and builds on the long-term project that initiated part of the thinking behind the hypothesis. Support for predictions were mixed and depended on year and the method used to map territory borders. We suggest that within-habitat patchiness, as well as model assumptions, should be further investigated for improved tests of the RDH in the future.

  18. 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.)

  19. Learning-Induced Gene Expression in the Hippocampus Reveals a Role of Neuron -Astrocyte Metabolic Coupling in Long Term Memory

    KAUST Repository

    Tadi, Monika

    2015-10-29

    We examined the expression of genes related to brain energy metabolism and particularly those encoding glia (astrocyte)-specific functions in the dorsal hippocampus subsequent to learning. Context-dependent avoidance behavior was tested in mice using the step-through Inhibitory Avoidance (IA) paradigm. Animals were sacrificed 3, 9, 24, or 72 hours after training or 3 hours after retention testing. The quantitative determination of mRNA levels revealed learning-induced changes in the expression of genes thought to be involved in astrocyte-neuron metabolic coupling in a time dependent manner. Twenty four hours following IA training, an enhanced gene expression was seen, particularly for genes encoding monocarboxylate transporters 1 and 4 (MCT1, MCT4), alpha2 subunit of the Na/K-ATPase and glucose transporter type 1. To assess the functional role for one of these genes in learning, we studied MCT1 deficient mice and found that they exhibit impaired memory in the inhibitory avoidance task. Together, these observations indicate that neuron-glia metabolic coupling undergoes metabolic adaptations following learning as indicated by the change in expression of key metabolic genes.

  20. Learning-Induced Gene Expression in the Hippocampus Reveals a Role of Neuron -Astrocyte Metabolic Coupling in Long Term Memory

    Science.gov (United States)

    Tadi, Monika; Allaman, Igor; Lengacher, Sylvain; Grenningloh, Gabriele; Magistretti, Pierre J.

    2015-01-01

    We examined the expression of genes related to brain energy metabolism and particularly those encoding glia (astrocyte)-specific functions in the dorsal hippocampus subsequent to learning. Context-dependent avoidance behavior was tested in mice using the step-through Inhibitory Avoidance (IA) paradigm. Animals were sacrificed 3, 9, 24, or 72 hours after training or 3 hours after retention testing. The quantitative determination of mRNA levels revealed learning-induced changes in the expression of genes thought to be involved in astrocyte-neuron metabolic coupling in a time dependent manner. Twenty four hours following IA training, an enhanced gene expression was seen, particularly for genes encoding monocarboxylate transporters 1 and 4 (MCT1, MCT4), alpha2 subunit of the Na/K-ATPase and glucose transporter type 1. To assess the functional role for one of these genes in learning, we studied MCT1 deficient mice and found that they exhibit impaired memory in the inhibitory avoidance task. Together, these observations indicate that neuron-glia metabolic coupling undergoes metabolic adaptations following learning as indicated by the change in expression of key metabolic genes. PMID:26513352

  1. 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.)

  2. Long-term collections

    CERN Multimedia

    Collectes à long terme

    2007-01-01

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

  3. Freshwater suspended particles: An intercomparison of long-term integrating sampling systems used for environmental radioactivity monitoring

    International Nuclear Information System (INIS)

    Sampling and sample preparation are known to carry large, but typically unknown uncertainty contributions to the final analytical data and there is a lack of qualitative and quantitative data on the comparability of results achieved by different sampling methods. To this end an intercomparison exercise was carried out to compare different methods for the collection of suspended material used for the monitoring of environmental radioactivity in freshwater bodies. This paper presents the results of this intercomparison exercise in which 'in situ' particulate sampling devices were compared in field exercises performed in the Kiev Reservoir (Ukraine) and in the Po River (Italy). The main criterion for this intercomparison was the agreement among the 137Cs activity concentrations associated with the suspended particles expressed as Bq x g-1 and among the (C/N) molar ratios measured on the suspended particles. In addition, an estimate of the uncertainties associated with each measuring method has been performed. (author)

  4. Long term effects of murine postnatal exposure to decabromodiphenyl ether (BDE-209) on learning and memory are dependent upon APOE polymorphism and age

    DEFF Research Database (Denmark)

    Reverte, Ingrid; Klein, Anders B

    2013-01-01

    Polybrominated diphenyl ethers (PBDEs) are a group of chemicals widely used as flame retardants; the lower brominated forms (1-5 bromine atoms) are highly neurotoxic and are presently not in commercial use. The highest brominated, the decabromodiphenyl ether (BDE-209) remains in use and its adverse and persistent effects are subject to debate. Of special concern are developmental exposures that can disrupt later-in-life adult health or aging. In this study, we investigated the effects of postnatal exposure to BDE-209 in combination with apolipoprotein E (apoE) genotype, a genetic factor that is associated with varied vulnerability for the development of neurodegenerative diseases. On postnatal day 10, transgenic mice of both sexes carrying apoE2, apoE3 and apoE4 were orally exposed to 0, 10 or 30mg/kg of BDE-209. Spatial reference memory was assessed in a Morris Water Maze (MWM) task at 4 and 12months of age. The levels of the brain-derived neurotrophic factor (BDNF) were determined in hippocampus and frontalcortex of mice at 5months of age. Mice carrying different apoE polymorphisms showed differences in the acquisition and retention of the spatial navigation task both at 4 and 12months of age. Postnatal exposure to BDE-209 induced long term effects in spatial learning, which were dependent upon age, sex and apoE genotype; these effects were more evident in apoE3 mice. BDNF levels were lower in the frontal cortex of apoE4 mice and higher in the hippocampus of exposed mice, independent of the genotype. The results of the present study provide evidence of long-lasting effects in spatial learning and memory after early exposure to BDE-209. Developmental exposure to this neurotoxicant may contribute to cognitive decline and abnormal aging.

  5. Long term effects of murine postnatal exposure to decabromodiphenyl ether (BDE-209) on learning and memory are dependent upon APOE polymorphism and age.

    Science.gov (United States)

    Reverte, Ingrid; Klein, Anders B; Domingo, José L; Colomina, Maria Teresa

    2013-01-01

    Polybrominated diphenyl ethers (PBDEs) are a group of chemicals widely used as flame retardants; the lower brominated forms (1-5 bromine atoms) are highly neurotoxic and are presently not in commercial use. The highest brominated, the decabromodiphenyl ether (BDE-209) remains in use and its adverse and persistent effects are subject to debate. Of special concern are developmental exposures that can disrupt later-in-life adult health or aging. In this study, we investigated the effects of postnatal exposure to BDE-209 in combination with apolipoprotein E (apoE) genotype, a genetic factor that is associated with varied vulnerability for the development of neurodegenerative diseases. On postnatal day 10, transgenic mice of both sexes carrying apoE2, apoE3 and apoE4 were orally exposed to 0, 10 or 30mg/kg of BDE-209. Spatial reference memory was assessed in a Morris Water Maze (MWM) task at 4 and 12months of age. The levels of the brain-derived neurotrophic factor (BDNF) were determined in hippocampus and frontal cortex of mice at 5months of age. Mice carrying different apoE polymorphisms showed differences in the acquisition and retention of the spatial navigation task both at 4 and 12months of age. Postnatal exposure to BDE-209 induced long term effects in spatial learning, which were dependent upon age, sex and apoE genotype; these effects were more evident in apoE3 mice. BDNF levels were lower in the frontal cortex of apoE4 mice and higher in the hippocampus of exposed mice, independent of the genotype. The results of the present study provide evidence of long-lasting effects in spatial learning and memory after early exposure to BDE-209. Developmental exposure to this neurotoxicant may contribute to cognitive decline and abnormal aging. PMID:23999552

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

    Directory of Open Access Journals (Sweden)

    Dong Chen

    2014-06-01

    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.

  7. Working memory training shows immediate and long-term effects on cognitive performance in children [v3; ref status: indexed, http://f1000r.es/4y9

    Directory of Open Access Journals (Sweden)

    Fiona Pugin

    2015-01-01

    Full Text Available Working memory is important for mental reasoning and learning processes. Several studies in adults and school-age children have shown performance improvement in cognitive tests after working memory training. Our aim was to examine not only immediate but also long-term effects of intensive working memory training on cognitive performance tests in children. Fourteen healthy male subjects between 10 and 16 years trained a visuospatial n-back task over 3 weeks (30 min daily, while 15 individuals of the same age range served as a passive control group. Significant differences in immediate (after 3 weeks of training and long-term effects (after 2-6 months in an auditory n-back task were observed compared to controls (2.5 fold immediate and 4.7 fold long-term increase in the training group compared to the controls. The improvement was more pronounced in subjects who improved their performance during the training. Other cognitive functions (matrices test and Stroop task did not change when comparing the training group to the control group. We conclude that visuospatial working memory training in children boosts performance in similar memory tasks such as the auditory n-back task. The sustained performance improvement several months after the training supports the effectiveness of the training.

  8. Working memory training shows immediate and long-term effects on cognitive performance in children [v2; ref status: indexed, http://f1000r.es/4rj

    Directory of Open Access Journals (Sweden)

    Fiona Pugin

    2014-11-01

    Full Text Available Working memory is important for mental reasoning and learning processes. Several studies in adults and school-age children have shown performance improvement in cognitive tests after working memory training. Our aim was to examine not only immediate but also long-term effects of intensive working memory training on cognitive performance tests in children. Fourteen healthy male subjects between 10 and 16 years trained a visuospatial n-back task over 3 weeks (30 min daily, while 15 individuals of the same age range served as a passive control group. Significant differences in immediate (after 3 weeks of training and long-term effects (after 2-6 months in an auditory n-back task were observed compared to controls (2.5 fold immediate and 4.7 fold long-term increase in the training group compared to the controls. The improvement was more pronounced in subjects who improved their performance during the training. Other cognitive functions (matrices test and Stroop task did not change when comparing the training group to the control group. We conclude that visuospatial working memory training in children boosts performance in similar memory tasks such as the auditory n-back task. The sustained performance improvement several months after the training supports the effectiveness of the training.

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

    Science.gov (United States)

    Hädicke, Jana; Engelmann, Mario

    2013-01-01

    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 performance and the investigative behaviour in commercially available 129S1/SvImJ and C57BL/6JOlaHsd mice and two F1-hybrids (129S1/SvImJ×C57BL/6JOlaHsd) by using the social discrimination procedure and its modification, the volatile fraction cage (VFC). Our data revealed an unimpaired olfactory long-term recognition memory not only in female and male 129S1/SvImJ and C57BL/6JOlaHsd mice but also in the two hybrid lines (129S1/SvImJxC57BL/6JOlaHsd) when the full ‘olfactory signature’ of the ‘to-be-recognized’ conspecific was presented. Under these conditions we also failed to detect differences in the long-term recognition memory between male and female mice of the tested strains and revealed that the oestrus cycle did not affect the performance in this memory task. The performance in the VFC, based only on the volatile components of the ‘olfactory signature’ of the ‘to-be-recognized’ conspecific, was similar to that observed under direct exposure except that females of one F1 hybrid group failed to show an intact long-term memory. Thus, the social discrimination procedure allowing direct access between the experimental subject and the stimulus animal(s) is highly suitable to investigate the impact of genetic manipulations on long-term memory in male and female mice of the strain 129S1/SvImJ, C57BL/6JOlaHsd and 129S1/SvImJxC57BL/6JOlaHsd hybrids. PMID:23342157

  10. Impaired long-term memory retention and working memory in sdy mutant mice with a deletion in Dtnbp1, a susceptibility gene for schizophrenia

    OpenAIRE

    Takao Keizo; Toyama Keiko; Nakanishi Kazuo; Hattori Satoko; Takamura Hironori; Takeda Masatoshi; Miyakawa Tsuyoshi; Hashimoto Ryota

    2008-01-01

    Abstract Background Schizophrenia is a complex genetic disorder caused by multiple genetic and environmental factors. The dystrobrevin-binding protein 1 (DTNBP1: dysbindin-1) gene is a major susceptibility gene for schizophrenia. Genetic variations in DTNBP1 are associated with cognitive functions, general cognitive ability and memory function, and clinical features of patients with schizophrenia including negative symptoms and cognitive decline. Since reduced expression of dysbindin-1 has be...

  11. Influence of Pre-Training Predator Stress on the Expression of c-fos mRNA in the Hippocampus, Amygdala, and Striatum Following Long-Term Spatial Memory Retrieval

    OpenAIRE

    DavidMDiamond; MichaelBVanElzakker; PhillipRZoladz

    2011-01-01

    We have studied the influence of pre-training psychological stress on the expression of c-fos mRNA following long-term spatial memory retrieval. Rats were trained to learn the location of a hidden escape platform in the radial-arm water maze, and then their memory for the platform location was assessed 24?h later. Rat brains were extracted 30?min after the 24-h memory test trial for analysis of c-fos mRNA. Four groups were tested: (1) Rats given standard training (Standard); (2) Rats given ca...

  12. Long-Term Collections

    CERN Multimedia

    Comité des collectes à long terme

    2011-01-01

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

  13. 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)

    Foley Kristie

    2006-12-01

    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.

  14. Collectes à long terme

    CERN Multimedia

    Collectes à long terme

    2014-01-01

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

  15. 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)

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

    2011-12-01

    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).

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

    Science.gov (United States)

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

    2015-01-20

    This work uses probabilistic methods to simulate a hypothetical geologic CO2 storage site in a depleted oil and gas field, where the large number of legacy wells would make it cost-prohibitive to sample all wells for all measurements as part of the postinjection site care. Deep well leakage potential scores were assigned to the wells using a random subsample of 100 wells from a detailed study of 826 legacy wells that penetrate the basal Cambrian formation on the U.S. side of the U.S./Canadian border. Analytical solutions and Monte Carlo simulations were used to quantify the statistical power of selecting a leaking well. Power curves were developed as a function of (1) the number of leaking wells within the Area of Review; (2) the sampling design (random or judgmental, choosing first the wells with the highest deep leakage potential scores); (3) the number of wells included in the monitoring sampling plan; and (4) the relationship between a well’s leakage potential score and its relative probability of leakage. Cases where the deep well leakage potential scores are fully or partially informative of the relative leakage probability are compared to a noninformative base case in which leakage is equiprobable across all wells in the Area of Review. The results show that accurate prior knowledge about the probability of well leakage adds measurable value to the ability to detect a leaking well during the monitoring program, and that the loss in detection ability due to imperfect knowledge of the leakage probability can be quantified. This work underscores the importance of a data-driven, risk-based monitoring program that incorporates uncertainty quantification into long-term monitoring sampling plans at geologic CO2 storage sites. PMID:25551254

  17. Evaluation of a low-cost procedure for sampling, long-term storage, and extraction of RNA from blood for qPCR analyses

    DEFF Research Database (Denmark)

    Mærkedahl, Rasmus Baadsgaard; FrØkiær, Hanne

    2015-01-01

    Abstract Background: In large clinical trials, where RNA cannot be extracted immediately after sampling, preserving RNA in whole blood is a crucial initial step in obtaining robust qPCR data. The current golden standard for RNA preservation is costly and designed for time-consuming column-based RNA-extraction. We investigated the use of lysis buffer for long-term storage of blood samples for qPCR analysis. Methods: Blood was collected from 13 healthy adults and diluted in MagMAX lysis/binding solution or PAXgene Blood RNA tubes and stored at -20 °C for 0, 1, or 4 months before RNA extraction by the matching method. RNA integrity, yield and purity were evaluated and the methods were compared by subsequent analyses of the gene expression levels of 18S, ACTB, IL1B, IL1RN, IL1R2, and PGK1 using qPCR. Results: The MagMAX system extracted 2.3-2.8 times more RNA per mL blood, with better performance in terms of purity, and with comparable levels of integrity relative to the PAXgene system. Gene expression analysis using qPCR of 18S, ACTB, IL1B, IL1RN, IL1R2, and the promising blood-specific reference gene, PGK1, revealed negligible differences (<1-fold) between the samples stored in MagMAX lysis/binding solution over time and between samples stored and extracted by the two systems. Conclusions: The MagMAX system can be used for storage of human blood for up to 4 months and is equivalent to the PAXgene system for RNA extraction. It furthermore, provides a means for significant cost reduction in large clinical trials.

  18. Comparison of Eleven Methods for Genomic DNA Extraction Suitable for Large-Scale Whole-Genome Genotyping and Long-Term DNA Banking Using Blood Samples

    Science.gov (United States)

    Psifidi, Androniki; Dovas, Chrysostomos I.; Bramis, Georgios; Lazou, Thomai; Russel, Claire L.; Arsenos, Georgios; Banos, Georgios

    2015-01-01

    Over the recent years, next generation sequencing and microarray technologies have revolutionized scientific research with their applications to high-throughput analysis of biological systems. Isolation of high quantities of pure, intact, double stranded, highly concentrated, not contaminated genomic DNA is prerequisite for successful and reliable large scale genotyping analysis. High quantities of pure DNA are also required for the creation of DNA-banks. In the present study, eleven different DNA extraction procedures, including phenol-chloroform, silica and magnetic beads based extractions, were examined to ascertain their relative effectiveness for extracting DNA from ovine blood samples. The quality and quantity of the differentially extracted DNA was subsequently assessed by spectrophotometric measurements, Qubit measurements, real-time PCR amplifications and gel electrophoresis. Processing time, intensity of labor and cost for each method were also evaluated. Results revealed significant differences among the eleven procedures and only four of the methods yielded satisfactory outputs. These four methods, comprising three modified silica based commercial kits (Modified Blood, Modified Tissue, Modified Dx kits) and an in-house developed magnetic beads based protocol, were most appropriate for extracting high quality and quantity DNA suitable for large-scale microarray genotyping and also for long-term DNA storage as demonstrated by their successful application to 600 individuals. PMID:25635817

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

    DEFF Research Database (Denmark)

    Larsen, Lone Heimann; Xu, Yijuan

    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 stored at -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.

  20. Interfering with post-learning hippocampal activity does not affect long-term consolidation of a context fear memory outside the hippocampus.

    Science.gov (United States)

    Gulbrandsen, Tine L; Sparks, Fraser T; Sutherland, Robert J

    2013-03-01

    There are still uncertainties about the role of the hippocampus (HPC) in memory consolidation. One theory, systems consolidation, states that the HPC is required for the initial storage of certain memories that subsequently become established in non-HPC networks through a lengthy process, involving an interaction with the HPC. A similar process may underlie the ability of multiple, distributed learning episodes of contextual fear conditioning to create a HPC-independent context fear memory, in a memory task that does not undergo systems consolidation with the mere passage of time [5]. The current study examined whether post-learning HPC activity is necessary to establish these HPC-independent context memories through distributed learning episodes. Rats received either three or six context conditioning sessions over the course of three days. The HPC-dependence of context memories was assessed using multisite, temporary inactivation of the HPC using ropivacaine during retention testing. We established that six conditioning sessions, but not three, created a memory that could be retrieved while the HPC was inactive. To directly test our hypothesis, HPC was inactivated after half of the six context-shock pairings in an independent group of rats. The rats were then tested for retention of context fear in the absence of HPC activity. Post-learning inactivation of the HPC did not affect the establishment of a HPC-independent context memory. These results favor the idea that at least one memory system outside the HPC can acquire context memories independently. PMID:23201356

  1. LONG TERM COLLECTIONS

    CERN Multimedia

    STAFF ASSOCIATION

    2010-01-01

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

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

    Science.gov (United States)

    Zhang, Ming; Wang, Hongbing

    2013-01-01

    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…

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

    Directory of Open Access Journals (Sweden)

    Ingrid K Tulloch

    2014-12-01

    Full Text Available 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.

  4. LONG TERM COLLECTIONS

    CERN Multimedia

    2004-01-01

    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.

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

    OpenAIRE

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

    2014-01-01

    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...

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

    OpenAIRE

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

    2010-01-01

    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...

  7. Intensive cognitive training in schizophrenia enhances working memory and associated prefrontal cortical efficiency in a manner that drives long-term functional gains.

    Science.gov (United States)

    Subramaniam, Karuna; Luks, Tracy L; Garrett, Coleman; Chung, Cleo; Fisher, Melissa; Nagarajan, Srikantan; Vinogradov, Sophia

    2014-10-01

    We investigated whether intensive computerized cognitive training in schizophrenia could improve working memory performance and increase signal efficiency of associated middle frontal gyri (MFG) circuits in a functionally meaningful manner. Thirty schizophrenia participants and 13 healthy comparison participants underwent fMRI scanning during a letter N-back working memory task. Schizophrenia participants were then randomly assigned to either 80 h (16 weeks) of cognitive training or a computer games control condition. After this intervention, participants completed a second fMRI N-back scanning session. At baseline, during 2-back working memory trials, healthy participants showed the largest and most significant activation in bilateral MFG, which correlated with task performance. Schizophrenia participants showed impaired working memory, hypoactivation in left MFG, and no correlation between bilateral MFG signal and task performance. After training, schizophrenia participants improved their 2-back working memory performance and showed increased activation in left MFG. They also demonstrated a significant association between enhanced task performance and right MFG signal, similar to healthy participants. Both task performance and brain activity in right MFG after training predicted better generalized working memory at 6-month follow-up. Furthermore, task performance and brain activity within bilateral MFG predicted better occupational functioning at 6-month follow-up. No such findings were observed in the computer games control participants. Working memory impairments in schizophrenia and its underlying neural correlates in MFG can be improved by intensive computerized cognitive training; these improvements generalize beyond the trained task and are associated with enduring effects on cognition and functioning 6 months after the intervention. PMID:24867353

  8. Enhancement of declarative memory associated with emotional content in a Brazilian sample

    Directory of Open Access Journals (Sweden)

    Frank J.E.

    2000-01-01

    Full Text Available Several studies have documented that emotional arousal may enhance long-term memory. This is an adaptation of a paradigm previously used in North American and European samples in investigations of the influence of emotion on long-term retention. A sample of 46 healthy adults of high and low educational levels watched a slide presentation of stories. A randomly assigned group watched a story with an arousing content and another group watched a neutral story. The stories were matched for structure and comprehensibility and the set and order of the 11 slides were the same in both conditions. Immediately after viewing the slide presentation, the participants were asked to rate the emotionality of the narrative. The arousing narrative was rated as being more emotional than the neutral narrative (t (44 = -3.6, P<0.001. Ten days later subjects were asked to remember the story and answer a multiple-choice questionnaire about it. The subjects who watched the arousing story had higher scores in the free recall measure (t (44 = -2.59, P<0.01. There were no differences between groups in the multiple-choice test of recognition memory (t (44 = 0.26. These findings confirm that an emotional arousing content enhances long-term declarative memory and indicate the possibility of applying this instrument to clinical samples of various cultural backgrounds.

  9. Dopamine D1 Receptors Regulate Protein Synthesis-Dependent Long-Term Recognition Memory via Extracellular Signal-Regulated Kinase 1/2 in the Prefrontal Cortex

    Science.gov (United States)

    Nagai, Taku; Takuma, Kazuhiro; Kamei, Hiroyuki; Ito, Yukio; Nakamichi, Noritaka; Ibi, Daisuke; Nakanishi, Yutaka; Murai, Masaaki; Mizoguchi, Hiroyuki; Nabeshima, Toshitaka; Yamada, Kiyofumi

    2007-01-01

    Several lines of evidence suggest that extracellular signal-regulated kinase1/2 (ERK1/2) and dopaminergic system is involved in learning and memory. However, it remains to be determined if the dopaminergic system and ERK1/2 pathway contribute to cognitive function in the prefrontal cortex (PFC). The amount of phosphorylated ERK1/2 was increased in…

  10. Duration of the Unconditioned Stimulus in Appetitive Conditioning of Honeybees Differentially Impacts Learning, Long-Term Memory Strength, and the Underlying Protein Synthesis

    Science.gov (United States)

    Marter, Kathrin; Grauel, M. Katharina; Lewa, Carmen; Morgenstern, Laura; Buckemüller, Christina; Heufelder, Karin; Ganz, Marion; Eisenhardt, Dorothea

    2014-01-01

    This study examines the role of stimulus duration in learning and memory formation of honeybees ("Apis mellifera"). In classical appetitive conditioning honeybees learn the association between an initially neutral, conditioned stimulus (CS) and the occurrence of a meaningful stimulus, the unconditioned stimulus (US). Thereby the CS…

  11. Exercise and sodium butyrate transform a subthreshold learning event into long-term memory via a brain-derived neurotrophic factor-dependent mechanism.

    Science.gov (United States)

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

    2013-09-01

    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 enables strong discrimination in the spatial memory task. Cognitive benefits of exercise match those attained with post-training sodium butyrate (NaB), a histone deacetylase (HDAC) inhibitor previously shown to enable subthreshold learning. We demonstrate that the enabling effects of exercise and NaB on subthreshold OLM learning are dependent on hippocampal BDNF upregulation, and are blocked by hippocampal infusion of BDNF short-interfering RNA. Exercise and NaB increased bdnf transcripts I and IV, and the increases were associated with BDNF promoter acetylation on H4K8 but not H4K12. These data provide support for the concept that exercise engages epigenetic control mechanisms and serves as a natural stimulus that operates in part like NaB and potentially other HDAC inhibitors, placing the brain into a state of readiness for plasticity. PMID:23615664

  12. Long-Term Supplementation with Beta Serum Concentrate (BSC, a Complex of Milk Lipids, during Post-Natal Brain Development Improves Memory in Rats

    Directory of Open Access Journals (Sweden)

    Jian Guan

    2015-06-01

    Full Text Available We have previously reported that the supplementation of ganglioside-enriched complex-milk-lipids improves cognitive function and that a phospholipid-enriched complex-milk-lipid prevents age-related cognitive decline in rats. This current study evaluated the effects of post-natal supplementation of ganglioside- and phospholipid-enriched complex-milk-lipids beta serum concentrate (BSC on cognitive function in young rats. The diet of male rats was supplemented with either gels formulated BSC (n = 16 or blank gels (n = 16 from post-natal day 10 to day 70. Memory and anxiety-like behaviors were evaluated using the Morris water maze, dark–light boxes, and elevated plus maze tests. Neuroplasticity and white matter were measured using immunohistochemical staining. The overall performance in seven-day acquisition trials was similar between the groups. Compared with the control group, BSC supplementation reduced the latency to the platform during day one of the acquisition tests. Supplementation improved memory by showing reduced latency and improved path efficiency to the platform quadrant, and smaller initial heading error from the platform zone. Supplemented rats showed an increase in striatal dopamine terminals and hippocampal glutamate receptors. Thus BSC supplementation during post-natal brain development improved learning and memory, independent from anxiety. The moderately enhanced neuroplasticity in dopamine and glutamate may be biological changes underlying the improved cognitive function.

  13. Accessibility Long Term Perspectives

    Directory of Open Access Journals (Sweden)

    Kay Axhausen

    2008-11-01

    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.

  14. Ro 20-1724 Ameliorates Learning Deficit and Long-Term Memory Impairment Secondary to Repeated Ketamine Anesthesia in Young Rats

    OpenAIRE

    Sheng Peng; Hai Yan Sun; Gong-Jian Liu; Xia Yang; George Mychaskiw II

    2013-01-01

    To investigate effects and possible mechanism of Ro 20-1724, a PDE4 inhibitor, on long-time learning and memory ability following repeated ketamine exposure in immature rats. Methods: Sixty 21-day-old SD rats were randomly divided into five groups (n = 12): C: Normal control group, S: Saline control group, K: Ketamine, K + Ro: Ketamine + Ro 20-1724, K + E: Ketamine + ethanol vehicle. Ro 20-1724 (0.5 mg·kg-1) or its vehicle (ethanol) was administered intraperitoneally 30 minutes after ketamin...

  15. 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 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

  16. Long Term Survivors of Glioblastoma

    Directory of Open Access Journals (Sweden)

    Nezih OKTAR

    2009-12-01

    Full Text Available There is no generally accepted definition of long-term GBM survivors (LTGBMS. Usually most authors define long-term GBM survivor as a patient who survives at least 3 years after the histological diagnosis of glioblastoma. LTGBMS are uncommon and are reported to occur in 0.5%-16% of cases. In our ENOK (Ege Neuro-Oncology Council cases we have 12 out of 372 GBM patients who survived more than 3 years (3.2%. The clinical and molecular factors that contribute to long-term survival are still unknown. Authors underline the association of glioblastoma long-term survival with prognostically favorable clinical factors, in particular young age and good initial performance score (KPS as well as MGMT promotor hypermethylation.

  17. Long-term telecommunication forecasting

    OpenAIRE

    Stordahl, Kjell

    2006-01-01

    The key word for the thesis is long-term demand forecasting which have been applied on telecommunications and especially on broadband accesses and traffic. The objective with the thesis has been to structure and present work on long-term broadband forecasting, to evaluate the forecasting results and to extract the learning. Each main chapter ends with a section called experiences and conclusions. The thesis is organized in seven main parts. The first part addresses application of the Delphi t...

  18. 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)

    Sandra Milena, Camelo Roa; Alfredo, Ardila.

    2013-12-01

    Full Text Available 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.

  19. 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)

    Viviane, Moreira-Aguiar; Allan Pablo, Lameira; Erick Quintas, Conde; Antônio, Pereira Júnior; Carlo Arrigo, Umiltà; Luiz de Gonzaga, Gawryszewski.

    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 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.

  20. Enhancement of declarative memory associated with emotional content in a Brazilian sample

    Scientific Electronic Library Online (English)

    J.E., Frank; C., Tomaz.

    2000-12-01

    Full Text Available Several studies have documented that emotional arousal may enhance long-term memory. This is an adaptation of a paradigm previously used in North American and European samples in investigations of the influence of emotion on long-term retention. A sample of 46 healthy adults of high and low educatio [...] nal levels watched a slide presentation of stories. A randomly assigned group watched a story with an arousing content and another group watched a neutral story. The stories were matched for structure and comprehensibility and the set and order of the 11 slides were the same in both conditions. Immediately after viewing the slide presentation, the participants were asked to rate the emotionality of the narrative. The arousing narrative was rated as being more emotional than the neutral narrative (t (44) = -3.6, P

  1. Long-term study of accommodative esotropia.

    OpenAIRE

    Ludwig, Irene H; Imberman, Susan P; Hilary W. Thompson; Parks, Marshall M

    2003-01-01

    PURPOSE: Previous studies of accommodative esotropia have been hampered by bias-prone methods of data collection and analysis and by small sample size. The studies have conflicting conclusions, causing uncertain results. This study aims to determine long-term results of standard treatment of accommodative esotropia and identify predictors of outcome, while minimizing bias in data collection and analysis, using the largest possible sample size. METHODS: A research assistant collected data from...

  2. Prophylactic Subacute Administration of Zinc Increases CCL2, CCR2, FGF2, and IGF-1 Expression and Prevents the Long-Term Memory Loss in a Rat Model of Cerebral Hypoxia-Ischemia

    Science.gov (United States)

    Blanco-Alvarez, Victor Manuel; Soto-Rodriguez, Guadalupe; Gonzalez-Barrios, Juan Antonio; Martinez-Fong, Daniel; Brambila, Eduardo; Torres-Soto, Maricela; Aguilar-Peralta, Ana Karina; Gonzalez-Vazquez, Alejandro; Tomás-Sanchez, Constantino; Limón, I. Daniel; Eguibar, Jose R.; Ugarte, Araceli; Hernandez-Castillo, Jeanett; Leon-Chavez, Bertha Alicia

    2015-01-01

    Prophylactic subacute administration of zinc decreases lipoperoxidation and cell death following a transient cerebral hypoxia-ischemia, thus suggesting neuroprotective and preconditioning effects. Chemokines and growth factors are also involved in the neuroprotective effect in hypoxia-ischemia. We explored whether zinc prevents the cerebral cortex-hippocampus injury through regulation of CCL2, CCR2, FGF2, and IGF-1 expression following a 10?min of common carotid artery occlusion (CCAO). Male rats were grouped as follows: (1) Zn96h, rats injected with ZnCl2 (one dose every 24?h during four days); (2) Zn96h + CCAO, rats treated with ZnCl2 before CCAO; (3) CCAO, rats with CCAO only; (4) Sham group, rats with mock CCAO; and (5) untreated rats. The cerebral cortex-hippocampus was dissected at different times before and after CCAO. CCL2/CCR2, FGF2, and IGF-1 expression was assessed by RT-PCR and ELISA. Learning in Morris Water Maze was achieved by daily training during 5 days. Long-term memory was evaluated on day 7 after learning. Subacute administration of zinc increased expression of CCL2, CCR2, FGF2, and IGF-1 in the early and late phases of postreperfusion and prevented the CCAO-induced memory loss in the rat. These results might be explained by the induction of neural plasticity because of the expression of CCL2 and growth factors. PMID:26355725

  3. Long-term telecommunication forecasting

    OpenAIRE

    Stordahl, Kjell

    2006-01-01

    The key word for the thesis is long-term demand forecasting which have been applied on telecommunications and especially on broadband accesses and traffic.The objective with the thesis has been to structure and present work on long-term broadband forecasting, to evaluate the forecasting results and to extract the learning. Each main chapter ends with a section called experiences and conclusions.The thesis is organized in seven main parts.The first part addresses application of the Delphi tech...

  4. Spine Expansion and Stabilization Associated with Long-term Potentiation

    OpenAIRE

    Yang, Yunlei; Wang, Xiao-Bin; Frerking, Matthew; Zhou, Qiang

    2008-01-01

    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...

  5. Long-term Video-EEG Monitoring for Paroxysmal Events

    OpenAIRE

    Ying-Ying Lee; Mei-Ying Lee; Yu-Tai Tsai; Chung-Yang Sung; Hsiang-Yao Hsieh; Siew-Na Lim; Peter Wu Hung; Tony Wu; I-an Chen

    2009-01-01

    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...

  6. Optimizing nucleic acid extraction from thyroid fine-needle aspiration cells in stained slides, formalin-fixed/paraffin-embedded tissues, and long-term stored blood samples

    Directory of Open Access Journals (Sweden)

    Marina M. L. Kizys

    2012-12-01

    Full Text Available OBJECTIVE: Adequate isolation of nucleic acids from peripheral blood, fine-needle aspiration cells in stained slides, and fresh and formalin-fixed/paraffin-embedded tissues is crucial to ensure the success of molecular endocrinology techniques, especially when samples are stored for long periods, or when no other samples can be collected from patients who are lost to follow-up. Here, we evaluate several procedures to improve current methodologies for DNA (salting-out and RNA isolation. MATERIALS AND METHODS: We used proteinase K treatment, heat shock, and other adaptations to increase the amount and quality of the material retrieved from the samples. RESULTS: We successfully isolated DNA and RNA from the samples described above, and this material was suitable for PCR, methylation profiling, real-time PCR and DNA sequencing. CONCLUSION: The techniques herein applied to isolate nucleic acids allowed further reliable molecular analyses. Arq Bras Endocrinol Metab. 2012;56(9:618-26

  7. Potential groundwater sampling sites for installation of a well network for long-term monitoring of agricultural chemicals in the High Plains Aquifer, Colorado

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data are in support of report DS 456 (Arnold and others, 2009). This dataset includes 90 potential groundwater sampling sites randomly generated using...

  8. 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

  9. Long-Term Physical and Mental Health Consequences of Childhood Physical Abuse: Results from a Large Population-Based Sample of Men and Women

    Science.gov (United States)

    Springer, Kristen W.; Sheridan, Jennifer; Kuo, Daphne; Carnes, Molly

    2007-01-01

    Objective: Child maltreatment has been linked to negative adult health outcomes; however, much past research includes only clinical samples of women, focuses exclusively on sexual abuse and/or fails to control for family background and childhood characteristics, both potential confounders. Further research is needed to obtain accurate,…

  10. Long-term continuous sampling of ¹²CO?, ¹³CO? and ¹²C¹?O¹?O in ambient air with a quantum cascade laser spectrometer.

    Science.gov (United States)

    McManus, J Barry; Nelson, David D; Zahniser, Mark S

    2010-03-01

    A recently developed laser spectroscopic instrument allows real-time continuous measurements of the stable isotopologues of carbon dioxide at ambient concentrations. This compact instrument offers sufficient precision (0.2 per thousand in 1 s, 0.02 per thousand in 60 s) and stability (drift in 1 h ofcascade of timescales and show some results in application of that method to the continuous sampling data set. PMID:20229384

  11. Long term stability of power systems

    Energy Technology Data Exchange (ETDEWEB)

    Kundur, P.; Gao, B. [Powertech Labs. Inc., Surrey, BC (Canada)

    1994-12-31

    Power system long term stability is still a developing subject. In this paper we provide our perspectives and experiences related to long term stability. The paper begins with the description of the nature of the long term stability problem, followed by the discussion of issues related to the modeling and solution techniques of tools for long term stability analysis. Cases studies are presented to illustrate the voltage stability aspect and plant dynamics aspect of long term stability. (author) 20 refs., 11 figs.

  12. What Does Long-Term Care Include?

    Medline Plus

    Full Text Available Video: "What Does Long-Term Care Include?" Long-term care involves a variety of services designed to meet a person's health or personal care needs during a short or long period of ...

  13. Long-term biosignals visualization and processing

    OpenAIRE

    Gomes, Ricardo Rafael Baptista

    2011-01-01

    Long-term biosignals acquisitions are an important source of information about the patients’state and its evolution. However, long-term biosignals monitoring involves managing extremely large datasets, which makes signal visualization and processing a complex task. To overcome these problems, a new data structure to manage long-term biosignals was developed. Based on this new data structure, dedicated tools for long-term biosignals visualization and processing were implemented. A mul...

  14. Analysis of long-term soxhlet tests

    International Nuclear Information System (INIS)

    Cyclic leaching patterns were exhibited by simulated waste glass and ceramic titanate (w/10% zeolite) materials during long-term elevated temperature soxhlet leaching studies. In the vitreous waste form, these patterns appear to be due to the formation and subsequent spallation of multilayered alteration products which were characterized using electron microprobe analysis. Electron microprobe studies of the leached titanate sample illustrated a more subdued attack of the surface with no alteration layer formation. During fabrication, cesium was concentrated in zeolite pockets which were leached, presumably by a process similar to that for glasses. One difficulty in leaching studies is the large sample volume required when very low concentrations of elements are to be determined. Studies presently in progress indicate that laser excited atomic fluorescence spectrometry is applicable to determining less than picogram quantities of cesium in 50 ?L sample volumes

  15. Natural radionuclides in the atmosphere. An interpretation of long term radionuclide data for lead-210 and beryllium-7 collected at Murdoch University for the Surface Air Sampling Program (SASP) of the Environmental Measurements Laboratory (US Department of Energy)

    International Nuclear Information System (INIS)

    This study examines various aspects of natural radioactive materials in the atmosphere over Perth in order to characterise the behaviour of these radionuclides. Data for this study was provided by the surface air sampling program (SASP) of the U.S. Department of Energy, which focuses on the lowest 2 metre layer of air; sampling being at 1.6 metres above the surface. The study particularly aimed to interpret correlation between existing radionuclide concentration data and meteorological data; which has been achieved in a qualitative sense. A general conclusion drawn form the observed results is that long-term averages of radionuclide concentrations have the highest correlation with climatic data; correlations between sample readings and contemporaneous weather data have the lowest correlation coefficients. Limitations in both the radionuclide and meteorological data were realised early in the project. The focus of the project accordingly changed from one of data processing to a broad-based review and documentation of particular disciplines that deal with atmospheric trace substances and their movement. A review served to bring together these disciplines and produce a handbook of background information required by anyone pursuing similar research. A number of future research projects are identified. 152 refs., 23 tabs., 40 figs

  16. Providing Long-Term Participation Incentive in Participatory Sensing

    OpenAIRE

    GAO, LIN; Hou, Fen; Huang, Jianwei

    2015-01-01

    Providing an adequate long-term participation incentive is important for a participatory sensing system to maintain enough number of active users (sensors), so as to collect a sufficient number of data samples and support a desired level of service quality. In this work, we consider the sensor selection problem in a general time-dependent and location-aware participatory sensing system, taking the long-term user participation incentive into explicit consideration. We study t...

  17. Physiological, Molecular and Genetic Mechanisms of Long-Term Habituation

    Energy Technology Data Exchange (ETDEWEB)

    Calin-Jageman, Robert J

    2009-09-12

    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.

  18. 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)

    Kingo, Osman Skjold; Staugaard, Søren Risløv; Krøjgaard, Peter

    2014-01-01

    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 v...

  19. 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)

    Kingo, Osman Skjold; Staugaard, SØren RislØv

    2014-01-01

    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.

  20. Subacute neurotoxicity following long-term exposure to carbaryl.

    Science.gov (United States)

    Branch, R A; Jacqz, E

    1986-04-01

    Carbaryl, a widely used insecticide, is reputed to have a wide safety margin. It can induce acute cholinesterase poisoning, which is rapidly reversible on discontinuation of exposure. Long-term sequelae from long-term exposure have not previously been described in humans. This report describes the experience of a 75-year-old man who had long-term excessive exposure to carbaryl and in whom a debilitating syndrome, including headaches, memory loss, proximal muscle weakness, muscle fasciculation, muscle cramps, and anorexia with marked weight loss, developed. At the time of diagnosis, serum pseudocholinesterase levels were low, and his major symptoms resolved on termination of exposure. Late clinical features were sleep apnea and progressive development of a peripheral neuropathy. The difficulty in diagnosing the cause of a group of relatively nonspecific symptoms raises the question of whether chronic carbaryl neurotoxicity might be occurring more frequently than previously suspected. PMID:3083676

  1. 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)

    F, Khan; J H, Vorster; M, van Vuuren; P, Mapham.

    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 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

  2. LONG TERM SYNAPTIC PLASTICITY IS IMPAIRED IN RATS WITH LESIONS OF THE VENTROLATERAL PREOPTIC NUCLEUS

    OpenAIRE

    Arrigoni, Elda; Lu, Jun; Vetrivelan, Ramalingam; Saper, Clifford B

    2009-01-01

    Impairment of memory functions has been frequently reported in models of sleep deprivation. Similarly, hippocampal long-term synaptic plasticity has been shown to be sensitive to sleep loss due to acute sleep restriction. However, such approaches are limited by the stressful nature of sleep deprivation, and because it is difficult to study long term sleep restriction in animals. Here we report the effects of chronic sleep loss on hippocampal long-term potentiation (LTP) in a rodent model for ...

  3. Long-Term Response to Sunitinib Therapy for Metastatic Renal Cell Carcinoma

    OpenAIRE

    Molina, Ana M.; Jia, Xiaoyu; Feldman, Darren R.; Hsieh, James J; Ginsberg, Michelle S.; Velasco, Susanne; Patil, Sujata; Motzer, Robert J.

    2013-01-01

    A subset of patients achieves long-term responses with sunitinib therapy. We present a retrospective study of long-term responders, defined as patients achieving durable complete response (CR) or remaining progression free for > 18 months while receiving sunitinib. Favorable risk factors associated with long-term response include a lack of bone metastases or lung metastases and favorable Memorial Sloan-Kettering Cancer Center (MSKCC) risk status.

  4. 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

  5. Long-term solar-terrestrial observations

    Science.gov (United States)

    1988-01-01

    The results of an 18-month study of the requirements for long-term monitoring and archiving of solar-terrestrial data is presented. The value of long-term solar-terrestrial observations is discussed together with parameters, associated measurements, and observational problem areas in each of the solar-terrestrial links (the sun, the interplanetary medium, the magnetosphere, and the thermosphere-ionosphere). Some recommendations are offered for coordinated planning for long-term solar-terrestrial observations.

  6. Projecting Long-Term Primary Energy Consumption

    OpenAIRE

    Csereklyei, Zsuzsanna; Humer, Stefan

    2013-01-01

    In this paper we use the long-term empirical relationship among primary energy consumption, real income, physical capital, population and technology, obtained by averaged panel error correction models, to project the long-term primary energy consumption of 56 countries up to 2100. In forecasting long-term primary energy consumption, we work with four different Shared Socioeconomic Pathway Scenarios (SSPs) developed for the Intergovernmental Panel on Climate Change (IPCC) framew...

  7. Long-term criticality analyses process

    International Nuclear Information System (INIS)

    The process for evaluating long-term disposal criticality control in a potential repository is being developed to support long-term disposal as well as ensure the acceptance of the Multi-Purpose Canister (MPC). This paper outlines the current Waste Package Development process for performing long-term disposal criticality control evaluations. The process allows the entire time period of disposal criticality control to be evaluated with the issues for each time period addressed separately

  8. SGK Protein Kinase Facilitates the Expression of Long-Term Potentiation in Hippocampal Neurons

    Science.gov (United States)

    Ma, Yun L.; Tsai, Ming C.; Hsu, Wei L.; Lee, Eminy H.Y.

    2006-01-01

    Previous studies showed that the serum- and glucocorticoid-inducible kinase ("sgk") gene plays an important role in long-term memory formation. The present study further examined the role of SGK in long-term potentiation (LTP). The dominant-negative mutant of "sgk," SGKS422A, was used to inactivate SGK. Results revealed a time-dependent increase…

  9. Representational Specificity of Within-Category Phonetic Variation in the Long-Term Mental Lexicon

    Science.gov (United States)

    Ju, Min; Luce, Paul A.

    2006-01-01

    This study examines the potential encoding in long-term memory of subphonemic, within-category variation in voice onset time (VOT) and the degree to which this encoding of subtle variation is mediated by lexical competition. In 4 long-term repetition-priming experiments, magnitude of priming was examined as a function of variation in VOT in words…

  10. How long will long-term potentiation last?

    OpenAIRE

    Abraham, Wickliffe C.

    2003-01-01

    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...

  11. Long-Term Low-Level Arsenic Exposure Is Associated with Poorer Neuropsychological Functioning: A Project FRONTIER Study

    Directory of Open Access Journals (Sweden)

    Robert Barber

    2011-03-01

    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.

  12. Long Term Sorption Diffusion Experiment (LTDE-SD). Supporting laboratory program - Sorption diffusion experiments and rock material characterisation. With supplement of adsorption studies on intact rock samples from the Forsmark and Laxemar site investigations

    Energy Technology Data Exchange (ETDEWEB)

    Widestrand, Henrik; Byegaard, Johan; Selnert, Eva; Skaalberg, Mats; Hoeglund, Susanne; Gustafsson, Erik (Geosigma AB, Uppsala (Sweden))

    2010-12-15

    The LTDE-SD experiment, (Long Term Sorption Diffusion Experiment) aims at increasing the scientific knowledge of sorption and diffusion under in situ conditions and to provide data for performance and safety assessment calculations. In this report, performance and results of laboratory sorption and diffusion experiments and porosity investigations using site-specific crushed and intact rock materials are presented, including a geological and mineralogical characterization of the samples. A synthetic groundwater and a part of the radionuclide tracer cocktail that was used for the in situ experiment were used also in the laboratory experiments. 13 radionuclide tracers were analysed in the laboratory experiments. The method descriptions from SKB Site Investigations were applied in order to enable comparisons with Site Investigations data. The water saturation porosity of 10 unaltered matrix rock samples from KA3065A02 and A03 is 0.26 +- 0.08% and two fracture material samples show porosities of 2.4% and 5.2% respectively. 14C-methylmethacrylate impregnation (the PMMA-method) show that the unaltered rock matrix porosity is relatively homogeneous with grain boundary porosity, while the porosity of fracture samples is heterogeneous and have increased porosity up to more than 10% in some parts. Through-diffusion experiments using tritiated water (H3HO) give a matrix diffusivity in the range from 2.7centre dot10-14 to 6.5centre dot10-14 m2/s in four samples from KA3065A02 and A03. The results of the porosity and diffusion measurements are coherent in ranges with earlier LTDE-SD measurements and are also in line with the SKB Site Investigations results. In the batch sorption experiments using crushed rock material, two matrix rock samples of Aevroe granodiorite, one red-stained altered Aevroe granodiorite sample and two chlorite-calcite dominated fracture samples were analysed for three different size fractions as a function of time up to 186 days contact time. The strongest sorption was observed in the fracture material samples. The two matrix rock samples and the altered sample showed nearly the same sorption properties. K{sub d} values in the range from 1centre dot10-3 to 1 m3/kg could be detected with the method. The individual results for different tracers and species are interpreted in the report. Sorption-diffusion on intact rock samples showed concentration losses that were basically in line to what could be expected from the outcome of the batch sorption experiments within the LTDE-SD and the Site Investigation program. Modelling of the diffusion process showed that the product of the sorption coefficient and the formation factor, K{sub d}centre dotF{sub f}, can only be resolved by analysis of the tracer concentration profiles in the rock

  13. Long Term Sorption Diffusion Experiment (LTDE-SD). Supporting laboratory program - Sorption diffusion experiments and rock material characterisation. With supplement of adsorption studies on intact rock samples from the Forsmark and Laxemar site investigations

    International Nuclear Information System (INIS)

    The LTDE-SD experiment, (Long Term Sorption Diffusion Experiment) aims at increasing the scientific knowledge of sorption and diffusion under in situ conditions and to provide data for performance and safety assessment calculations. In this report, performance and results of laboratory sorption and diffusion experiments and porosity investigations using site-specific crushed and intact rock materials are presented, including a geological and mineralogical characterization of the samples. A synthetic groundwater and a part of the radionuclide tracer cocktail that was used for the in situ experiment were used also in the laboratory experiments. 13 radionuclide tracers were analysed in the laboratory experiments. The method descriptions from SKB Site Investigations were applied in order to enable comparisons with Site Investigations data. The water saturation porosity of 10 unaltered matrix rock samples from KA3065A02 and A03 is 0.26 ± 0.08% and two fracture material samples show porosities of 2.4% and 5.2% respectively. 14C-methylmethacrylate impregnation (the PMMA-method) show that the unaltered rock matrix porosity is relatively homogeneous with grain boundary porosity, while the porosity of fracture samples is heterogeneous and have increased porosity up to more than 10% in some parts. Through-diffusion experiments using tritiated water (H3HO) give a matrix diffusivity in the range from 2.7·10-14 to 6.5·10-14 m2/s in four samples from KA3065A02 and A03. The results of the porosity and diffusion measurements are coherent in ranges with earlier LTDE-SD measurements and are also in line with the SKB Site Investigations results. In the batch sorption experiments using crushed rock material, two matrix rock samples of Aevroe granodiorite, one red-stained altered Aevroe granodiorite sample and two chlorite-calcite dominated fracture samples were analysed for three different size fractions as a function of time up to 186 days contact time. The strongest sorption was observed in the fracture material samples. The two matrix rock samples and the altered sample showed nearly the same sorption properties. Kd values in the range from 1·10-3 to 1 m3/kg could be detected with the method. The individual results for different tracers and species are interpreted in the report. Sorption-diffusion on intact rock samples showed concentration losses that were basically in line to what could be expected from the outcome of the batch sorption experiments within the LTDE-SD and the Site Investigation program. Modelling of the diffusion process showed that the product of the sorption coefficient and the formation factor, Kd·Ff, can only be resolved by analysis of the tracer concentration profiles in the rock

  14. 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

  15. The Long-Term Swap Rate and a General Analysis of Long-Term Interest Rates

    OpenAIRE

    Biagini, Francesca; Gnoatto, Alessandro; Härtel, Maximilian

    2015-01-01

    We introduce here for the first time the long-term swap rate, characterised as the fair rate of an overnight indexed swap with infinitely many exchanges. Furthermore we analyse the relationship between the long-term swap rate, the long-term yield, see [4], [5], and [25], and the long-term simple rate, considered in [8] as long-term discounting rate. We finally investigate the existence of these long-term rates in two term structure methodologies, the Flesaker-Hughston model ...

  16. Long-term radiological surveillance program

    International Nuclear Information System (INIS)

    The U.S. Energy Research and Development Administration (ERDA) is committed to ensure that no public safety hazard exists or has developed at any site used for nuclear experimentation. This commitment is assured through strict adherence to applicable safety regulations during active site occupation and through the use of long-term monitoring programs after site activities have terminated. This program is carried out by the Environmental Protection Agency/Environmental Monitoring and Support Laboratory-Las Vegas (EPA/EMSL-LV) under the cognizance of the ERDA/NV. The Tatum Dome Test Site, used for Project Dribble, was the site of two nuclear and two nonnuclear events between 1964 and 1970. No radioactive contaminants were released to the environment by the actual tests themselves; however, minor releases did occur in connection with reentry drilling. The site was decontaminated, restored to near preshot conditions, and deactivated in 1972. No need for bioenvironmental monitoring, soil sampling, or seismic monitoring has been demonstrated for this site. However, water from all water-bearing formations above the Cook Mountain limestone and from the surface in the vicinity of the site will be periodically sampled, including deep wells, domestic wells, surface waters, and municipal water supplies. The sampling program will continue until it can be established that the need no longer exists. Annual reports will be prepared to document the results of the program. (auth)

  17. Long-Term Interest Rates and Public Debt Maturity

    OpenAIRE

    Sakalauskaite, Ieva; BEETSMA, Roel; GIULIODORI, Massimo

    2013-01-01

    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.

  18. Diabetes MILES--Australia (management and impact for long-term empowerment and success: methods and sample characteristics of a national survey of the psychological aspects of living with type 1 or type 2 diabetes in Australian adults

    Directory of Open Access Journals (Sweden)

    Speight Jane

    2012-02-01

    Full Text Available Abstract Background Successful management of diabetes requires attention to the behavioural, psychological and social aspects of this progressive condition. The Diabetes MILES (Management and Impact for Long-term Empowerment and Success Study is an international collaborative. Diabetes MILES--Australia, the first Diabetes MILES initiative to be undertaken, was a national survey of adults living with type 1 or type 2 diabetes in Australia. The aim of this study was to gather data that will provide insights into how Australians manage their diabetes, the support they receive and the impact of diabetes on their lives, as well as to use the data to validate new diabetes outcome measures. Methods/design The survey was designed to include a core set of self-report measures, as well as modules specific to diabetes type or management regimens. Other measures or items were included in only half of the surveys. Cognitive debriefing interviews with 20 participants ensured the survey content was relevant and easily understood. In July 2011, the survey was posted to 15,000 adults (aged 18-70 years with type 1 or type 2 diabetes selected randomly from the National Diabetes Services Scheme (NDSS database. An online version of the survey was advertised nationally. A total of 3,338 eligible Australians took part; most (70.4% completed the postal survey. Respondents of both diabetes types and genders, and of all ages, were adequately represented in both the postal and online survey sub-samples. More people with type 2 diabetes than type 1 diabetes took part in Diabetes MILES--Australia (58.8% versus 41.2%. Most respondents spoke English as their main language, were married/in a de facto relationship, had at least a high school education, were occupied in paid work, had an annual household income > $AUS40,000, and lived in metropolitan areas. Discussion A potential limitation of the study is the under-representation of respondents from culturally and linguistically diverse backgrounds (including Aboriginal and Torres Strait Islander origin. Diabetes MILES--Australia represents a major achievement in the study of diabetes in Australia, where for the first time, the focus is on psychosocial and behavioural aspects of this condition at a national level.

  19. Long Term Care Minimum Data Set (MDS)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Long-Term Care Minimum Data Set (MDS) is a standardized, primary screening and assessment tool of health status that forms the foundation of the comprehensive...

  20. 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

  1. MD iMAP: Long Term Care

    Data.gov (United States)

    U.S. Department of Health & Human Services — This is a MD iMAP hosted service. Find more information at http://imap.maryland.gov. DHMH has identified licensed long-term care and assisted living facilities in...

  2. Long-term solar activity predictions

    Science.gov (United States)

    Mcintosh, P. S.; Brown, G. M.; Buhmann, R.; Clark, T.; Fougere, P. F.; Hunter, H.; Lincoln, J. V.; Sargent, H. H., III; Timothy, J. G.; Lin, Y. Z.

    1979-01-01

    The need for long term solar activity predictions is addressed. The spatial organization of solar activity is described including applications for predictions, and ancient evidence for solar variability. Methods of predicting sunspot numbers are discussed. The inherent accuracy of the methods varies considerably, but a typical error bar 20%. The accuracy of sunspot cycle predictions is considered along with long term predictions of great solar events.

  3. The Lithuanian Long-term Care System

    OpenAIRE

    2010-01-01

    The remarkable growth of older population has moved long-term care to the front ranks of the social policy agenda in the European Union. This paper addresses the issue of the longterm care in Lithuania, its philosophy, the legal and funding regularities, management issues and LTC policy. Its attempt is also to provide a complex set of information about the demand side of long-term care including the demographic characteristics of people in need. The paper also presents a detailed description ...

  4. Reversing cerebellar long-term depression

    OpenAIRE

    Lev-Ram, Varda; Mehta, Samar B; Kleinfeld, David; Tsien, Roger Y

    2003-01-01

    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 be re...

  5. Foreign Currency for Long-Term Investors

    OpenAIRE

    Viceira, Luis; Campbell, John; White, Joshua

    2003-01-01

    Conventional wisdom holds that conservative investors should avoid exposure to foreign currency risk. Even if they hold foreign equities, they should hedge the currency exposure of these positions and hold only domestic Treasury bills. This paper argues that the conventional wisdom may be wrong for long-term investors. Domestic bills are risky for long-term investors, because real interest rates vary over time and bills must be rolled over at uncertain future interest rates. This risk can be ...

  6. Toward a comprehensive long term nicotine policy

    OpenAIRE

    Gray, N; Henningfield, J; BENOWITZ, N.; Connolly, G; Dresler, C; Fagerstrom, K; M. Jarvis(Imperial College, London, United Kingdom); Boyle, P.

    2005-01-01

    Global tobacco deaths are high and rising. Tobacco use is primarily driven by nicotine addiction. Overall tobacco control policy is relatively well agreed upon but a long term nicotine policy has been less well considered and requires further debate. Reaching consensus is important because a nicotine policy is integral to the target of reducing tobacco caused disease, and the contentious issues need to be resolved before the necessary political changes can be sought. A long term and comprehen...

  7. Institutionalization and Organizational Long-term Success

    OpenAIRE

    Denise L. Fleck

    2007-01-01

    Institutionalization processes have an ambivalent effect on organizational long-term success. Even though they foster organizational stability and permanence, they also bring about rigidity and resistance to change. As a result, successful organizations are likely to lose their competitive advantage over time. The paper addresses this issue through the investigation of the institutionalization processes of two long-lived companies: General Electric, a firm that has been a long-term success an...

  8. Long-term prophylaxis in bipolar disorder.

    OpenAIRE

    Taylor, MJ; Goodwin, GM

    2006-01-01

    Bipolar disorder is a major cause of disability, and the prevention of relapse is a key management goal. Pharmacological interventions, effectively delivered through enhanced clinical care, are central to long-term management. This article summarises the available evidence for a range of pharmacological options, and provides guidance on common issues in clinical management in line with current practice guidelines. The use of medications for long-term prophylaxis should be considered in all pa...

  9. 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 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)

  10. LONG-TERM MONITORING SENSOR NETWORK

    Energy Technology Data Exchange (ETDEWEB)

    Stephen P. Farrington; John W. Haas; Neal Van Wyck

    2003-10-16

    Long-term monitoring (LTM) associated with subsurface contamination sites is a key element of Long Term Stewardship and Legacy Management across the Department of Energy (DOE) complex. However, both within the DOE and elsewhere, LTM is an expensive endeavor, often exceeding the costs of the remediation phase of a clean-up project. The primary contributors to LTM costs are associated with labor. Sample collection, storage, preparation, analysis, and reporting can add a significant financial burden to project expense when extended over many years. Development of unattended, in situ monitoring networks capable of providing quantitative data satisfactory to regulatory concerns has the potential to significantly reduce LTM costs. But survival and dependable operation in a difficult environment is a common obstacle to widespread use across the DOE complex or elsewhere. Deploying almost any sensor in the subsurface for extended periods of time will expose it to chemical and microbial degradation. Over the time-scales required for in situ LTM, even the most advanced sensor systems may be rendered useless. Frequent replacement or servicing (cleaning) of sensors is expensive and labor intensive, offsetting most, if not all, of the cost savings realized with unattended, in situ sensors. To enable facile, remote monitoring of contaminants and other subsurface parameters over prolonged periods, Applied Research Associates, Inc has been working to develop an advanced LTM sensor network consisting of three key elements: (1) an anti-fouling sensor chamber that can accommodate a variety of chemical and physical measurement devices based on electrochemical, optical and other techniques; (2) two rapid, cost effective, and gentle means of emplacing sensor packages either at precise locations directly in the subsurface or in pre-existing monitoring wells; and (3) a web browser-based data acquisition and control system (WebDACS) utilizing field-networked microprocessor-controlled smart sensors housed in anti-fouling sensor chambers. The monitoring network is highly versatile and can be applied to a variety of subsurface sensing scenarios in different media. However, the current project focused on monitoring water quality parameters of pH, oxidation-reduction potential, conductivity, and temperature in groundwater.

  11. Diabetes MILES--Australia (management and impact for long-term empowerment and success): Methods and sample characteristics of a national survey of the psychological aspects of living with type 1 or type 2 diabetes in Australian adults

    OpenAIRE

    Speight Jane; Browne Jessica L; Holmes-Truscott Elizabeth; Hendrieckx Christel; Pouwer Frans

    2012-01-01

    Abstract Background Successful management of diabetes requires attention to the behavioural, psychological and social aspects of this progressive condition. The Diabetes MILES (Management and Impact for Long-term Empowerment and Success) Study is an international collaborative. Diabetes MILES--Australia, the first Diabetes MILES initiative to be undertaken, was a national survey of adults living with type 1 or type 2 diabetes in Australia. The aim of this study was to gather data that will pr...

  12. Soil seed bank of plant species as a function of long-term soil management and sampled depth / Banco de sementes de espécies vegetais em função de distintos manejos do solo por longo período e profundidade amostrada

    Scientific Electronic Library Online (English)

    G, Concenço; J.C, Salton; R.C, Brevilieri; P.B, Mendes; M.L, Secretti.

    2011-12-01

    Full Text Available Objetivou-se avaliar o nível de infestação por plantas daninhas em áreas submetidas a manejos distintos por 16 anos: (1) agricultura em sistema convencional de preparo; (2) agricultura em sistema plantio direto; (3) integração lavoura/pecuária; (4) somente pecuária. Amostras de solos destas áreas fo [...] ram coletadas em três profundidades (0-5, 5-10 and 10-15 cm), depositadas em potes plásticos e levadas a casa de vegetação. O solo era revolvido a cada 20 dias, quando as plantas daninhas presentes eram identificadas e coletadas. Foram avaliados cobertura por plantas daninhas; densidade de plantas daninhas e massa seca da comunidade infestante. Foi também conduzida análise fitoecológica em função dos distintos manejos e profundidades. Áreas onde pastagens estiveram presentes tiveram menor infestação por plantas daninhas que áreas onde somente agricultura era utilizada. A composição florística difere entre sistemas de manejo. Áreas onde a pecuária está presente apresentaram número de plântulas de espécies daninhas muito inferior a sistemas onde somente agricultura está presente. A presença de criação de gado afeta o potencial de emergência das espécies presentes no banco de sementes do solo. Sistemas de agricultura sem integração apresentam alta similaridade em termos de composição de espécies ao longo do perfil do solo enquanto sistemas integrados com pecuária apresentam pouca relação entre as profundidades amostradas. Modelos conservacionistas de exploração do solo contribuem com a redução da severidade de ocorrência de espécies daninhas a longo prazo. Abstract in english This study aimed at assessing the level of weed infestation indifferent areas that were submitted to different soil management for 16 years. Four management systems were studied: (1) agriculture only under conventional tillage system; (2) agriculture only under no-till system; (3) crop-livestock int [...] egrationcrop-livestock integration; (4) livestock only. These areas were sampled at three soil depths (0-5, 5-10 and 10-15 cm), and soil was stored in plastic pots and taken to a greenhouse, where soil moisture and weight were standardized. Soil was kept near 70% moisture field capacity, being revolved every 20 days when all seedling emerged from soil were counted, identified and collected for dry mass assessment. The soil coverage by weeds, number of weed seedlings and dry mass of the weedy community were assessed. A phytoecological analysis was conducted. Weed composition is differentdifferent among management systems after 16 years. Areas with livestock showed much smaller number of weed species in comparison to systems where only grain crops are grown. The presence of livestock affects the potential of germination of soil seed bank. Agriculture systems are similar in terms of weed composition along soil profile, while systems involving livestock show little relation in what regards such sampled depths. Conservationist models of land exploration contribute to reduce severity of weed species occurrence in the long term.

  13. Hormonal changes during long-term isolation.

    Science.gov (United States)

    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

    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

  14. Long-term follow-up study and long-term care of childhood cancer survivors

    Directory of Open Access Journals (Sweden)

    Hyeon Jin Park

    2010-04-01

    Full Text Available The number of long-term survivors is increasing in the western countries due to remarkable improvements in the treatment of childhood cancer. The long-term complications of childhood cancer survivors in these countries were brought to light by the childhood cancer survivor studies. In Korea, the 5-year survival rate of childhood cancer patients is approaching 70%; therefore, it is extremely important to undertake similar long-term follow-up studies and comprehensive long-term care for our population. On the basis of the experiences of childhood cancer survivorship care of the western countries and the current Korean status of childhood cancer survivors, long-term follow-up study and long-term care systems need to be established in Korea in the near future. This system might contribute to the improvement of the quality of life of childhood cancer survivors through effective intervention strategies.

  15. Long-term symptom relief after septoplasty.

    Science.gov (United States)

    Sundh, Carolina; Sunnergren, Ola

    2015-10-01

    The results for long-term symptom relief after septoplasty are contradictory in reviewed publications but the findings suggest that results are unsatisfactory. In this study, we analyzed and compared short- and long-term symptom relief after septoplasty and factors possibly associated with symptom relief. 111 patients that underwent septoplasty between 2008 and 2010 were included in the study. Medical charts were reviewed for preoperative characteristics and assessments. Data on short-term symptom relief (6 months) were retrieved from the Swedish National Quality Registry for Septoplasty; data on long-term symptom relief (34-70 months) were collected through a questionnaire. Upon the 34-70 month follow-up, 53% of the patients reported that symptoms either remained or had worsened and 83% reported nasal obstruction. Degree of symptom relief was significantly higher among patients not reporting nasal obstruction than among patients reporting nasal obstruction at long-term follow-up. The proportion of patients that reported "my symptoms are gone" declined from 53% after 6 months to 18% after 34-70 months. None of the factors taken into consideration, age at surgery, gender, follow-up time, primary operation/reoperation, history of nasal trauma, self-reported allergy, rhinometric obstruction, or same sided rhinometric, clinical and subjective nasal obstruction were associated with symptom relief. The long-term results after septoplasty are unsatisfactory. A majority of patients report that their symptoms remain after septoplasty. PMID:25432640

  16. Long-term prognosis of depression in primary care.

    OpenAIRE

    Simon, G. E.

    2000-01-01

    This article uses longitudinal data from a primary care sample to examine long-term prognosis of depression. A sample of 225 patients initiating antidepressant treatment in primary care completed assessments of clinical outcome (Hamilton Depression Rating Scale and the mood module of the Structured Clinical Interview for DSM-IIIR) 1, 3, 6, 9, 12, 18 and 24 months after initiating treatment. The proportion of patients continuing to meet criteria for major depression fell rapidly to approximate...

  17. Long-term dependence in exchange rates

    Directory of Open Access Journals (Sweden)

    G. Pavlides

    1999-01-01

    Full Text Available The extent to which exchange rates of four major currencies against the Greek Drachma exhibit long-term dependence is investigated using a R/S analysis testing framework. We show that both classic R/S analysis and the modified R/S statistic if enhanced by bootstrapping techniques can be proven very reliable tools to this end. Our findings support persistence and long-term dependence with non-periodic cycles for the Deutsche Mark and the French Franc series. In addition a noisy chaos explanation is favored over fractional Brownian motion. On the contrary, the US Dollar and British Pound were found to exhibit a much more random behavior and lack of any long-term structure.

  18. Explaining long-term growth in Namibia

    Scientific Electronic Library Online (English)

    Joel Hinaunye, Eita; Charlotte B, du Toit.

    2009-04-01

    Full Text Available 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.

  19. 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)

  20. Synapse Specificity of Long-Term Potentiation Breaks Down with Aging

    Science.gov (United States)

    Ris, Laurence; Godaux, Emile

    2007-01-01

    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,…

  1. Long-term home care scheduling

    DEFF Research Database (Denmark)

    Gamst, Mette; Jensen, Thomas Sejr

    2011-01-01

    In several countries, home care is provided for certain citizens living at home. The long-term home care scheduling problem is to generate work plans spanning several days such that a high quality of service is maintained and the overall cost is kept as low as possible. A solution to the problem provides detailed information on visits and visit times for each employee on each of the covered days. We propose a branch-and-price algorithm for the long-term home care scheduling problem. The pricing ...

  2. Education and Long-Term Unemployment

    OpenAIRE

    Garrouste, Christelle; Kozovska, Kornelia; Arjona Perez, Elena

    2010-01-01

    This paper investigates the relationship between education and long-term unemployment when considering regional economic differences and other relevant variables at the individual and at the local level, using data from the 2004-2006 EU-SILC (11 countries). The analysis has been run using both a binary logit model and a binary scobit model. Our results suggest that the probability of an individual to be in long-term unemployment decreases with her educational level. There is a decrease in ret...

  3. Long-term changes in Saturn's troposphere

    International Nuclear Information System (INIS)

    Attention is given to the results of a long term monitoring study of Saturn's H2 quadrupole and CH4 band absorptions outside the equatorial zone, over an interval of half a Saturn year that covers most of the perihelion half of Saturn's elliptical orbit (which is approximately bounded by the equinoxes). Marked long term changes are noted in the CH4 absorption, accompanied by weakly opposite changes in the H2 absorption. Seasonal changes are inferred on the basis of temporal variations in absorption. Spatial measurements have also been made in the 6450 A NH3 band since the 1980 equinox. 42 references

  4. Using XML for long-term preservation

    OpenAIRE

    Müller, Eva; Andersson, Stefan; Klosa, Uwe; Hansson, Peter; Siira, Erik

    2003-01-01

    One of the objectives of the project is to explore the possibility of using XML as a format for long-term preservation. For this reason, we evaluated the practical use of XML in different parts of the system before deciding on the design. An XML schema, DiVA XML schema, has been developed to describe the inter-relationships amongst the various data elements and processes, and to support long-term preservation of the actual documents. XML Schema provides a means for defining the structur...

  5. Long term planning for wind energy development

    International Nuclear Information System (INIS)

    In a planning system intended to be governed primarily by policies in statutory plans a reasonable horizon for long term planning is 10 years or longer. Because of statutory requirements, developers have no option but to pay due regard to, and take a full part in, long term planning. The paper examines the type of policies which have emerged in the last few years to cater for wind energy development. It canvasses the merits of different types of policies. Finally, it discusses the policy framework which may emerge to cater for development outside NFFO. (Author)

  6. Quality of Life and Functional Health Status of Long-Term Meditators

    OpenAIRE

    Deborah Black; Leigh Wilson; Ramesh Manocha

    2012-01-01

    Background. There is very little data describing the long-term health impacts of meditation. Aim. To compare the quality of life and functional health of long-term meditators to that of the normative population in Australia. Method. Using the SF-36 questionnaire and a Meditation Lifestyle Survey, we sampled 343 long-term Australian Sahaja Yoga meditation practitioners and compared their scores to those of the normative Australian population. Results. Six SF-36 subscales (bodily pain, general ...

  7. Motivational readiness for physical activity and quality of life in long-term lung cancer survivors

    OpenAIRE

    Clark, Matthew M.; Novotny, Paul J.; Patten, Christi A; Rausch, Sarah M.; Garces, Yolanda I; Jatoi, Aminah; Sloan, Jeff A; Yang, Ping

    2008-01-01

    Little is known about the relationship between motivational readiness for physical activity and quality of life (QOL) in long-term lung cancer survivors. Long-term survivors are considered those who are living 5 years or more following a cancer diagnosis. This project examined the relationship between a self-report measure of motivational readiness for physical activity and QOL in a sample of 272 long-term lung cancer survivors. Participants (54% male, average age 70 years old) completed the ...

  8. Strategic long term planning in mining

    Scientific Electronic Library Online (English)

    G.L., Smith.

    Full Text Available The fundamental challenge facing mineral and metal companies is how to create sustainable value while operating within mandated strategic bounds, identified constraints, and variable market and economic conditions. This can be achieved by allowing the fixed physical nature of the mineral asset to dr [...] ive definition of the optimal technical solution to mining and processing activities, and developing and resourcing a strategically aligned portfolio of production entities that creates flexibility to near- and longer-term business environment shifts, i.e. a production mix that allows variation of output to respond to short term market variation, within a long term context. The practical achievement of this outcome is enabled by the concept of strategic long term planning. The core elements of strategic long term planning in the metals and minerals industry, and the relationship between them, are expanded. The strategic long term planning framework is a logic construct that enables delivery of an optimized, strategically-aligned business plan from the mineral asset portfolio using a set of tools and techniques with a common language, standards, systems and processes to align decisions and actions on a cyclical basis.

  9. Long term trends in the lower ionosphere.

    Czech Academy of Sciences Publication Activity Database

    Laštovi?ka, Jan

    Ostseebad Kühlungsborn : Leibniz Institut für Atmosphären Physik , 2002 - (Heinrich, W.). s. 31 [276. WE Heraeus Seminar. 13.05.2002-16.05.2002, Ostseebad Kühlungsborn] R&D Projects: GA AV ?R IAA3042101; GA AV ?R KSK3012103 Institutional research plan: CEZ:AV0Z3042911 Keywords : long-term trends * lower ionosphere * upper atmosphere Subject RIV: DG - Athmosphere Sciences, Meteorology

  10. [Long-term plasticity of HVC-RA synapses in adult male zebra finches].

    Science.gov (United States)

    Li, Feng-Ling; Li, Dong-Feng

    2013-12-25

    Long-term synaptic plasticity is considered as a key part of the neural mechanism of learning and memory. The production of learned vocalization of male zebra finches is closely related to high vocal center (HVC)-robust nucleus of the arcopallium (RA) pathway. However, the long-term plasticity of HVC-RA synapses is unclear. This study investigated the long-term plasticity of HVC-RA synapses in adult male zebra finches through in vivo field potential recording. The results showed that physiologic stimulation, i.e., ? rhythmic stimulation and low frequency stimulation could not effectively induce long-term synaptic plasticity. The former leaded to no change of the amplitudes of evoked population spikes, and the latter induced short-term depression (STD) of the amplitudes of the second evoked population spikes caused by paired pulses. But high frequency stimulation induced long-term depression (LTD) of the amplitudes of evoked population spikes to show out long-term synaptic plasticity. These results suggest that LTD represents the long-term plasticity of HVC-RA synapses in adult male zebra finches, which may be a key part of the neural mechanism of vocal learning and memory and can explain the plasticity of adult song to some degree. PMID:24343715

  11. Long-term depression of nociception and pain in healthy volunteers

    OpenAIRE

    Rottmann, Silke

    2009-01-01

    Synaptic plasticity, including long-term potentiation (LTP) and long-term depression (LTD), represents a cellular model of learning and memory. LTP, a long-lasting increase of synaptic strength, can be induced by electrical stimulation with a high frequency. Low-frequency stimulation (LFS) leads to a decrease of synaptic transmission referred to as LTD. Synaptic plasticity was shown in the nociceptive system. LTP is suggested to be involved in central sensitization of pain, leading to a so-ca...

  12. Long term consequences on spatial learning-memory of low-calorie diet during adolescence in female rats; hippocampal and prefrontal cortex BDNF level, expression of NeuN and cell proliferation in dentate gyrus.

    Science.gov (United States)

    Kaptan, Zülal; Akgün-Dar, Kadriye; Kapucu, Ay?egül; Dedeakayo?ullar?, Huri; Batu, ?ule; Üzüm, Gülay

    2015-08-27

    Calorie restriction (CR) is argued to positively affect general health, longevity and normally occurring age-related reduction of cognition. Obesity during adolescence may adversely affect cognition in adulthood but, to date effects of CR have not been investigated. We hypothesized that feeding with as low as 15% low-calorie diet (LCD) during adolescence would increase hippocampal and prefrontal BDNF (Brain-derived neurotrophic factor) levels, proliferative cells and neuron numbers in dentate gyrus (DG), thus positively affecting spatial memory in adulthood. Spatial learning-memory function was improved in adult female Sprague-Dawley rats fed with LCD during adolescence. PCNA (Proliferating cell nuclear antigen-cell proliferation marker) expressing cells and NeuN (Neuronal nuclear antigen-neuron marker) expressing cells in hippocampus DG which are critically involved in memory were increased. Hippocampus and prefrontal cortex BDNF levels were increased while serum glucose levels and level of lipid peroxidation indicator malondialdehyde in serum and hippocampus were reduced. Our unique results suggest that improved cognition in adult rats with LCD feeding during adolescence may result from the increase of neurogenesis and BDNF. These findings reveal the importance of nutrition in adolescence for cognitive function in adulthood. Our results may be useful for further studies aiming to treat age-related cognitive impairments. PMID:26072462

  13. Hot functional test chemistry - long term experience

    International Nuclear Information System (INIS)

    Primary circuit materials undergo general corrosion in high temperature, deoxygenated, neutral or mildly alkaline solutions to form thin oxide films. These oxide layers (films) serve as protective film and mitigate the further corrosion of primary materials. Inner chromium-rich oxide layer has low cation diffusion coefficients and thus control iron and nickel transport from the metal surface to the outer layer and their dissolution into the coolant. Much less corrosion products are generated by the compact, integral and stable oxide (passivation) layer. For the latest Czech and Slovak stations commissioned (Temelin and Mochovce) a modified Hot Functional Test (HFT) chemistry was developed in the NRI Rez. Chromium rich surface layer formatted due to modified HTF chemistry ensures lower corrosion rates and radiation field formation and thus also mitigates crud formation during operation. This procedure was also designed to prepare the commissioned unit for the further proper water chemistry practise. Mochovce 1 (SK) was the first station commissioned using these recommendations in 1998. Mochovce 2 (1999) and Temelin 1 and 2 (CZ - 2000 and 2002) were subsequently commissioned using these guidelines too. The main principles of the controlled primary water chemistry applied during the hot functional tests are reviewed and importance of the water chemistry, technological and other relevant parameters is stressed regarding to the quality of the passive layer formed on the primary system surfaces. Samples from Mochovce indicated that duplex oxide layers up to 20 ?m thick were produced, which were mainly magnetite substituted with nickel and chromium (e.g. 60-65% Fe, 18-28% Cr, 9-12% Ni, <1% Mn and 1-2% Si on a stainless steel primary circuit sample). Long term operation experience from both nuclear power plants are discussed in this paper. Radiation field, occupational radiation exposure and corrosion layers evolution during the first c. ten years of operation are compared and presented. The operation experience from all above mentioned units showed a low level of corrosion products in the primary system as well as low dose rates. Thus, there is no need for any larger decontamination works. The effect of the initial passivation performed during hot functional tests and the primary water chemistry on the radioactivity level and overall radiation situation of corrosion products is discussed. (author)

  14. Changes of gamut volume during long-term tests

    OpenAIRE

    Ká?erová, Silvia; Veselý, Michal; Dzik, Petr; Št?pánková, Eva

    2013-01-01

    The stability of inkjet prints and photographs is influenced by the factors of the surrounding environment. The most harmful factors of environment are the light and the pollutants like ozone. Durability of inkjet prints is besides the ink composition, affected by the type of receiving layer. In this paper will be discussed the lightfastness of inkjet prints and photographs during the long-term ageing tests. Inkjet prints were prepared using both dye-based and pigment-based inks. The sampl...

  15. Enhanced Brain Connectivity in Long-term Meditation Practitioners

    OpenAIRE

    Luders, Eileen; Clark, Kristi; Narr, Katherine L.; Toga, Arthur W.

    2011-01-01

    Very little is currently known about the cerebral characteristics that underlie the complex processes of meditation as only a limited number of studies have addressed this topic. Research exploring structural connectivity in meditation practitioners is particularly rare. We thus acquired diffusion tensor imaging (DTI) data of high angular and spatial resolution and used atlas-based tract mapping methods to investigate white matter fiber characteristics in a well-matched sample of long-term me...

  16. Carbonation-Related Microstructural Changesin Long-Term Durability Concrete

    OpenAIRE

    Silva Cláudio A. Rigo da; Reis Rubens J. Pedrosa; Lameiras Fernando Soares; Vasconcelos Wander Luiz

    2002-01-01

    This paper discusses the effects of carbonation on the microstructure of Portland cement concrete for long-term durability applications. A class C40 concrete (characteristic compression strength between 40 MPa and 44 MPa on the 28th day, according to Brazilian standard NBR 8953) was chosen for the experimental study of the carbonation effects, from which test samples were molded for accelerated test under a 100%-CO2 atmosphere after physical and mechanical characterization. It was observed th...

  17. Data of long term atmospheric diffusion experiments (Winter, 1992)

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Takashi; Chino, Masamichi; Yamazawa, Hiromi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    1998-10-01

    The data were obtained in the long-term atmospheric diffusion experiments in the Tokai area, autumn, 1991 which were a part of the Evaluation Safety Demonstration Experiments of Environmental Radiation entrusted with the Science and Technology Agency. The experiments were conducted by JAERI in cooperation with the Japan Weather Association. The report includes tracer concentration data of surface sampling points and meteorological data. (author)

  18. INTELLIGENT SYSTEM FOR LONG TERM LOAD FORECASTING

    Directory of Open Access Journals (Sweden)

    Roohi Kapoor

    2011-01-01

    Full Text Available Long term load forecasting plays an important role in the economic optimization and secured operation of electric power systems. The plans of the electric power sector have been done and developed with the aid of statistical prediction methods. Electric utilities companies need monthly peak and yearly load forecasting for budget planning, maintenance scheduling and fuel management. The present work presents a comparative study between the approach based on neural network and a hybrid fuzzy neural technique for long term load forecasting of Haryana State. A large number of influencing factors have been examined and tested. This paper presents a system developed for the prediction of maximum electric demand and consumption of electricity. The strength of this technique lies in its ability to reduce appreciable computational time and its comparable accuracy with other modeling techniques.

  19. Quantifying Long-term Scientific Impact

    CERN Document Server

    Wang, Dashun; Barabási, Albert-László

    2013-01-01

    An ability to accurately assess the long-term impact of a scientific discovery has implications from science policy to individual reward. Yet, the documented lack of predictability of citation based measures frequently used to gauge impact, from impact factors to short-term citations, raises a fundamental question: is there long-term predictability in citation patterns? Here we derive a mechanistic model for the citation dynamics of individual papers, allowing us to collapse the citation histories of papers from different journals and disciplines into a single curve, indicating that all papers follow the same universal temporal pattern. The observed patterns not only help us uncover the basic mechanisms that govern scientific impact, but also offer reliable measures of influence with potential policy implications.

  20. Case presentation: long-term treatment.

    Science.gov (United States)

    Glucksman, Myron L

    2013-01-01

    The long-term (14 years) psychodynamic psychotherapy and pharmacotherapy of a depressed, suicidal, self-mutilating female patient is described. Her diagnoses included Chronic Posttraumatic Stress Disorder, Borderline Personality Disorder, and Recurrent Major Depression. Treatment was punctuated with repeated hospitalizations for self-mutilation (cutting) and suicidal ideation. A major determinant for her psychopathology was sexual abuse by her father from ages 6 to 14. This resulted in feelings of guilt and rage that she repressed and acted out through self-mutilating and suicidal behavior. A prolonged negative transference gradually became ambivalent, then positive. This was associated with her internalization of the healing qualities of the therapeutic relationship. She also gained insight into the reasons for her need to punish herself. Her initial self-representation as unworthy and bad was transformed into perceiving herself as a worthwhile, loving person. This case illustrates the role of long-term treatment for a complex, life-threatening, psychiatric disorder. PMID:24001161

  1. Timber joints under long-term loading

    DEFF Research Database (Denmark)

    Feldborg, T.; Johansen, M.

    1988-01-01

    This report describes tests and results from stiffness and strength testing of splice joints under long-term loading. During two years of loading the spicimens were exposed to cyclically changing relative humidity. After the loading period the specimens were short-term tested. The connectors were integral nail-plates and nailed steel and plywood gussets. The report is intended for designers and researchers in timber engineering.

  2. Long-term outcomes of sports injuries

    OpenAIRE

    Dekker, Rienk

    2004-01-01

    Participation in sports is an important way to spend spare time. Being actively involved in sports has clear advantages, like the improvement of physical endurance and the prevention of Western diseases. However, it can be questioned whether these advantages are not outweighted by the notable side effects: the occurrence and the adverse outcome of a large number of injuries. Long-term consequences are of importance in determining this outcome, since sportsmen are generally young and, conseque...

  3. Long-term outcomes of infantile spasms

    OpenAIRE

    Seak Hee Oh; Eun-Hye Lee; Min-Hee Joung; Mi-Sun Yum; Tae-Sung Ko

    2010-01-01

    Purpose : The aims of this study were to investigate the long-term outcomes in children with infantile spasms (IS) and to identify the prognostic factors influencing their neurodevelopment. Methods : We retrospectively evaluated seventy two children over five years old who were treated for IS at Asan Medical Center, Seoul, Korea, between 1994 and 2007. Forty-three children were contacted by telephone or medical follow-up to assess their current neurodevelopmental status. Multiple logistic reg...

  4. Long-term Treatment in Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Derya ULUDÜZ

    2008-05-01

    Full Text Available Multiple sclerosis is a chronic neuro-inflammatory and neuro-degenerative disease of the CNS which may present and progress heterogeneously. It is rather a spectrum and currently there is some evidence that long term treatments may be effective for its relapsing forms. Such treatments have been shown to reduce the number of attacks and MRI-related disease burden with the probability to slow progression. These long term treatments are considered to have mostly an anti-inflammatory activity. Interferon beta group drugs and glatiramer acetate are likely to exert their therapeutic effects through a number of different mechanisms but probably the main one is anti-inflammatory being through such mechanisms, but their efficacy is limited. Immunosuppressive drugs such as Mitoxantrone and Cyclophosphamide are accepted to have a more potent anti-inflammatory effect with better efficacy, but with more serious adverse effects. Natalizumab is one of the new players in the field with a supposedly better efficacy than the interferon betas or glatiramer acetate, but yet carries an increased risk of being associated with progressive mulifocal leukoencepalopathy as a serious side effect. As not all patients with MS progress and end up with disability, long-term treatments may not be necessary for every individual, who receives the diagnosis of MS. It is the MS neurologist who should consider first whether the patient should be put on long term treatment and once such a decision is given, then which one. The agents to be selected should be determined according to the benefit-risk ratio for each patient individually. In this review these issues are discussed. (Archives of Neuropsychiatry 2008; 45 Supplement: 26-36

  5. Long term evolution 4G and beyond

    CERN Document Server

    Yacoub, Michel; Figueiredo, Fabrício; Tronco, Tania

    2016-01-01

    This book focus on Long Term Evolution (LTE) and beyond. The chapters describe different aspects of research and development in LTE, LTE-Advanced (4G systems) and LTE-450 MHz such as telecommunications regulatory framework, voice over LTE, link adaptation, power control, interference mitigation mechanisms, performance evaluation for different types of antennas, cognitive mesh network, integration of LTE network and satellite, test environment, power amplifiers and so on. It is useful for researchers in the field of mobile communications.

  6. Safety of long-term PPI therapy

    DEFF Research Database (Denmark)

    Reimer, Christina

    2013-01-01

    Proton pump inhibitors have become the mainstay of medical treatment of acid-related disorders. Long-term use is becoming increasingly common, in some cases without a proper indication. A large number of mainly observational studies on a very wide range of possible associations have been published in the past decade and are critically reviewed in this article and the existing evidence is evaluated and translated into possible clinical consequences. Based on the existing evidence the benefits of ...

  7. Debt consolidation with long-term debt

    OpenAIRE

    Scheer, Alexander

    2015-01-01

    The Great Recession has sent debt levels to a post-WWII high for several advanced economies, reviving the discussion of fiscal consolidation. This paper assesses the macroeconomic implications of tax-based versus spending-based consolidation within the framework of a New Keynesian model with long term government debt. Three results stand out: First, tax-based consolidations are inflationary whereas spending-based ones are deflationary. Second, the net benefits of inflation increase in the ave...

  8. Long-term consequences of anorexia nervosa.

    Science.gov (United States)

    Meczekalski, Blazej; Podfigurna-Stopa, Agnieszka; Katulski, Krzysztof

    2013-07-01

    Anorexia nervosa (AN) is a psychiatric disorder that occurs mainly in female adolescents and young women. The obsessive fear of weight gain, critically limited food intake and neuroendocrine aberrations characteristic of AN have both short- and long-term consequences for the reproductive, cardiovascular, gastrointestinal and skeletal systems. Neuroendocrine changes include impairment of gonadotropin releasing-hormone (GnRH) pulsatile secretion and changes in neuropeptide activity at the hypothalamic level, which cause profound hypoestrogenism. AN is related to a decrease in bone mass density, which can lead to osteopenia and osteoporosis and a significant increase in fracture risk in later life. Rates of birth complications and low birth weight may be higher in women with previous AN. The condition is associated with fertility problems, unplanned pregnancies and generally negative attitudes to pregnancy. During pregnancy, women with the condition have higher rates of hyperemesis gravidarum, anaemia and obstetric complications, as well as impaired weight gain and compromised intrauterine foetal growth. It is reported that 80% of AN patients are affected by a cardiac complications such as sinus bradycardia, a prolonged QT interval on electrocardiography, arrythmias, myocardial mass modification and hypotension. A decrease in bone mineral density (BMD) is one of the most important medical consequences of AN. Reduced BMD may subsequently lead to a three- to seven-fold increased risk of spontaneous fractures. Untreated AN is associated with a significant increase in the risk of death. Better detection and sophisticated therapy should prevent the long-term consequences of this disorder. The aims of treatment are not only recovery but also prophylaxis and relief of the long-term effects of this disorder. Further investigations of the long-term disease risk are needed. PMID:23706279

  9. The discovery of long-term potentiation.

    OpenAIRE

    Lømo, Terje

    2003-01-01

    This paper describes circumstances around the discovery of long-term potentiation (LTP). In 1966, I had just begun independent work for the degree of Dr medicinae (PhD) in Per Andersen's laboratory in Oslo after an eighteen-month apprenticeship with him. Studying the effects of activating the perforant path to dentate granule cells in the hippocampus of anaesthetized rabbits, I observed that brief trains of stimuli resulted in increased efficiency of transmission at the perforant path-granule...

  10. INTELLIGENT SYSTEM FOR LONG TERM LOAD FORECASTING

    OpenAIRE

    Roohi Kapoor; Gopal Krishan; Neha Kapoor

    2011-01-01

    Long term load forecasting plays an important role in the economic optimization and secured operation of electric power systems. The plans of the electric power sector have been done and developed with the aid of statistical prediction methods. Electric utilities companies need monthly peak and yearly load forecasting for budget planning, maintenance scheduling and fuel management. The present work presents a comparative study between the approach based on neural network and a hybrid fuzzy ne...

  11. Long-term anticoagulation. Indications and management.

    OpenAIRE

    Stults, B. M.; Dere, W H; Caine, T H

    1989-01-01

    Each year half a million persons in the United States receive long-term anticoagulant therapy to prevent venous and arterial thromboembolism. Unfortunately, the relative benefits and risks of anticoagulant therapy have not been adequately quantified for many thromboembolic disorders, and the decisions as to whether, for how long, and how intensely to administer anticoagulation are often complex and controversial. Several expert panels have published recommendations for anticoagulant therapy f...

  12. French Approach for Long Term Storage Safety

    International Nuclear Information System (INIS)

    IRSN presents its statement regarding long-term storage facilities; in France, the regulatory documents do not define the long term duration. The storage facility lifetime can only be appreciated according to the needs and materials stored therein. However, the magnitude of the long-term can be estimated at a few hundred years compared to a few decades for current storage. Usually, in France, construction of storage facilities is driven from the necessity various necessities, linked to the management of radioactive material (eg spent fuel) and to the management of radioactive waste. Because of the variety of 'stored materials and objects' (fission product solutions, plutonium oxide powders, activated solids, drums containing technological waste, spent fuel...), a great number of storage facility design solutions have been developed (surface, subsurface areas, dry or wet conditions...) in the World. After describing the main functions of a storage facility, IRSN displays the safety principles and the associated design principles. The specific design principles applied to particular storage (dry or wet spent fuel storage, depleted uranium or reprocessed uranium storage, plutonium storage, waste containing tritium storage, HLW and ILLW storage...) are also presented. Finally, the concerns due to the long-term duration storage and related safety assessment are developed. After discussing these issues, IRSN displays its statement. The authorization procedures governing the facility lifetime are similar to those of any basic nuclear installation, the continuation of the facility operation remaining subject to periodic safety reviews (in France, every 10 years). The applicant safety cases have to show, that the safety requirements are always met; this requires, at minimum, to take into account at the design stage, comfortable design margins. (author)

  13. Bacterial cellulose : long-term biocompatibility studies

    OpenAIRE

    P??rtile, Renata Aparecida Nedel; Moreira, Susana Margarida Gomes; Costa, Rui M. Gil da; Correia, Alexandra; Guard??o, Lu??sa; Gartner, F??tima; Vilanova, Manuel; Gama, F.M.

    2012-01-01

    The bacterial cellulose (BC) secreted by G. xylinus is a network of pure cellulose nanofibers, which has high crystallinity, wettability and mechanical strength. These characteristics make BC an excellent material for tissue engineering constructs, noteworthy for artificial vascular grafts. In this work, the in vivo biocompatibility of BC membranes produced by two G. xylinus strains was analyzed through histological analysis of long-term subcutaneous implants in the mice. The BC implants caus...

  14. Long Term Evolution of Plasma Wakefields

    OpenAIRE

    Sahai, Aakash A.; Katsouleas, T. C.; Tsung, F. S.; Mori, W. B.

    2014-01-01

    We study the long-term evolution (LTE) of plasma wakefields over multiple plasma-electron periods and few plasma-ion periods, much less than a recombination time. The evolution and relaxation of such a wakefield-perturbed plasma over these timescales has important implications for the upper limits of repetition-rates in plasma colliders. Intense fields in relativistic lasers (or intense beams) create plasma wakefields (modes around {\\omega}pe) by transferring energy to the p...

  15. Managing soils for long-term productivity

    OpenAIRE

    Syers, J.K.

    1997-01-01

    Meeting the goal of long-term agricultural productivity requires that soil degradation be halted and reversed. Soil fertility decline is a key factor in soil degradation and is probably the major cause of declining crop yields. There is evidence that the contribution of declining soil fertility to soil degradation has been underestimated. Sensitivity to soil degradation is implicit in the assessment of the sustainability of land management practices, with wide recognition of the fact that soi...

  16. Long-term reductions in tinnitus severity

    OpenAIRE

    Folmer Robert L

    2002-01-01

    Abstract Background This study was undertaken to assess long-term changes in tinnitus severity exhibited by patients who completed a comprehensive tinnitus management program; to identify factors that contributed to changes in tinnitus severity within this population; to contribute to the development and refinement of effective assessment and management procedures for tinnitus. Methods Detailed questionnaires were mailed to 300 consecutive patients prior to their initial appointment at the Or...

  17. Long-term plant availability of actinides

    International Nuclear Information System (INIS)

    Environmental releases of actinide elements raise issues about which data are very limited. Quantitative information is required to assess the long-term behavior of actinides and their potential hazards resulting from the transport through food chains leading to man. This study provides valuable information on the effects of weathering and aging on the uptake of actinides from soil by range and crop plants grown under realistic field conditions

  18. Long-term home hemodialysis in children

    Science.gov (United States)

    Borra, Sonia; Kaye, Michael

    1971-01-01

    Experience with chronic hemodialysis as a definitive form of therapy is described for six children aged 11 to 15 years at the onset. Duration on dialysis in the home has been between one and 4½ years. All patients are alive and rehabilitated without serious complications. It is concluded that although transplantation is the most desirable form of treatment for children, long-term hemodialysis is an alternative acceptable second choice. ImagesFIG. 2 PMID:5150193

  19. On the fractional Eulerian numbers and equivalence of maps with long term power-law memory (integral Volterra equations of the second kind) to Grünvald-Letnikov fractional difference (differential) equations

    Science.gov (United States)

    Edelman, Mark

    2015-07-01

    In this paper, we consider a simple general form of a deterministic system with power-law memory whose state can be described by one variable and evolution by a generating function. A new value of the system's variable is a total (a convolution) of the generating functions of all previous values of the variable with weights, which are powers of the time passed. In discrete cases, these systems can be described by difference equations in which a fractional difference on the left hand side is equal to a total (also a convolution) of the generating functions of all previous values of the system's variable with the fractional Eulerian number weights on the right hand side. In the continuous limit, the considered systems can be described by the Grünvald-Letnikov fractional differential equations, which are equivalent to the Volterra integral equations of the second kind. New properties of the fractional Eulerian numbers and possible applications of the results are discussed.

  20. Titanium for long-term tritium storage

    International Nuclear Information System (INIS)

    Due to the reduction of nuclear weapon stockpile, there will be an excess of tritium returned from the field. The excess tritium needs to be stored for future use, which might be several years away. A safe and cost effective means for long term storage of tritium is needed. Storing tritium in a solid metal tritide is preferred to storing tritium as a gas, because a metal tritide can store tritium in a compact form and the stored tritium will not be released until heat is applied to increase its temperature to several hundred degrees centigrade. Storing tritium as a tritide is safer and more cost effective than as a gas. Several candidate metal hydride materials have been evaluated for long term tritium storage. They include uranium, La-Ni-Al alloys, zirconium and titanium. The criteria used include material cost, radioactivity, stability to air, storage capacity, storage pressure, loading and unloading conditions, and helium retention. Titanium has the best combination of properties and is recommended for long term tritium storage

  1. Long-term monitoring for closed special sites

    International Nuclear Information System (INIS)

    A methodology is presented for planning and implementing a long-term environmental monitoring program for closed special radioactive waste disposal sites. The steps in the method involve collection of the available background information on the site history, site and area characteristics, waste inventory, pathway analysis, prior monitoring programs, applicable standards, and the legal/regulatory requirements. This information is coupled with factors such as experience, half-life, radionuclide migration rates, and potential hazard to develop a monitoring program. As an example, a site-specific long-term monitoring program is described for the AMAX site using the available information. Sampling techniques and practices for the monitoring program are discussed and techniques and practices expected to be available in the future are considered. 7 references, 2 tables

  2. Switched capacitor arrays analog memory for sparse data sampling

    International Nuclear Information System (INIS)

    We present the design and the test performed on ADeLinel, a Full-Custom Analog Memory for sparse data sampling. It has been designed as an array of switched capacitors. It is only one channel of 8 cells. The control part of the ADeLine chip is custom designed for the size reduction, high speed performance and low power dissipation. The memory has been integrated in double poly, double metal AMS 0.8 ?m CMOS. It has 3.5 V input and output swings, a linearity within ± 6 mV in a 2 V range and 11 bits of resolution. (author)

  3. Long-Term Monitoring Research Needs: A DOE Perspective

    Science.gov (United States)

    Moore, B.; Davis, C. B.

    2002-05-01

    The U.S. Department of Energy's Office of Environmental Management is responsible for dealing with the nation's legacy of Cold War radioactive and hazardous waste and contamination. Major efforts are underway to deal with this legacy; these are expected to last up to decades and cost up to billions of dollars at some sites. At all sites, however, active remediation must eventually cease; if hazards then remain, the site must enter into a long-term stewardship mode. In this talk we discuss aspects of long-term monitoring pertinent to DOE sites, focusing on challenges to be faced, specific goals or targets to be met, and research needs to be addressed in order to enable DOE to meet its long-term stewardship obligations. DOE LTM research needs fall into three major categories: doing what we can do now much more efficiently; doing things we cannot do now; and proving the validity of our monitoring programs. Given the enormity of the DOE obligations, it will be highly desirable to develop much more efficient monitoring paradigms. Doing so will demand developing autonomous, remote monitoring networks of in situ sensors capable of replacing (or at least supplementing to a large extent) conventional groundwater and soil gas sampling and analysis programs. The challenges involved range from basic science (e.g., inventing in situ sensors for TCE that do not demand routine maintenance) to engineering (attaining superior reliability in data reporting in remote networks) to ergonomics (developing decent ways of selecting and presenting the "right" information from the monitoring network) to regulatory affairs (presenting convincing evidence that the more efficient systems actually provide superior monitoring). We explore these challenges in some detail, focusing on the "long" in long-term monitoring as it applies to DOE sites. Monitoring system performance validation and, ultimately, regulator and stakeholder acceptance of site closure and long-term stewardship plans depend critically on the validity and uncertainty in models used to predict contaminant fate and transport. This is an area of active research at the present time. We survey joint research initiatives in this area involving DOE along with USGS, U.S. EPA, U.S. NRC, and U.S. DOA and non-Federal collaborators, and explore their potential for furthering DOE long-term monitoring needs and objectives.

  4. Long-term investigation of tritium contamination of biosphere

    International Nuclear Information System (INIS)

    The danger is indicated of the growing contamination of the biosphere with tritium and the significance is stressed of controlling tritium release. The results of long-term investigation of contamination with tritium of ground and surface waters in the vicinity of the A-1 nuclear power plant at Jaslovske Bohunice are reported. Electrolytical isotope separation was used in sample preparations. The volume of samples was reduced and the resulting concentrate was mixed with a liquid scintillator. The results of scintillation measurement are evaluated statistically. The method made possible the determination of tritium activity not exceeding 15 TU which corresponds to typical tritium concentration in non-active laboratories. (L.O.)

  5. Long-term outcomes of infantile spasms

    Directory of Open Access Journals (Sweden)

    Seak Hee Oh

    2010-01-01

    Full Text Available Purpose : The aims of this study were to investigate the long-term outcomes in children with infantile spasms (IS and to identify the prognostic factors influencing their neurodevelopment. Methods : We retrospectively evaluated seventy two children over five years old who were treated for IS at Asan Medical Center, Seoul, Korea, between 1994 and 2007. Forty-three children were contacted by telephone or medical follow-up to assess their current neurodevelopmental status. Multiple logistic regression was used to calculate odds ratios (ORs and 95% confidence interval (95% CIs of risk factors for unfavorable outcomes. Results : The mean follow-up duration for these 43 children was 7.2¡?#?.5 ;years (range, 4.5 to 13.0 years. Of these, 13 (30.2% had cryptogenic and 30 (69.8% had symptomatic IS. Eleven (25.6% children were initially treated with adrenocorticotrophic hormone (ACTH therapy, with a mean treatment lag of 1.3¡?#?.9 ;months (range; 0.1 to 7.0 months. Eighteen (41.8% children clinically responded to initial treatment, as shown by EEG response. Overall, 22 (51.2% children had at least moderate neurodevelopmental disorders and 2 (4.8% died. In univariate analysis, etiology (symptomatic and poor electroclinical response to initial treatment were related to long-term unfavorable outcomes. In multivariate analysis, response to primary treatment was the sole significant independent risk factor with a high OR. Conclusion : Overall prognosis of children with IS was poor. Electroclinical non-responsiveness to initial treatment was related to unfavorable long-term outcomes, indicating that initial control of seizures may be important in reducing the likelihood of poor neurodevelopment.

  6. Long-term governance for sustainability

    International Nuclear Information System (INIS)

    Meritxell Martell spoke of the long-term aspects of radioactive waste management. She pointed out that decision-making processes need to be framed within the context of sustainability, which means that a balance should be sought between scientific considerations, economic aspects and structural conditions. Focusing on structural aspects, Working Group 3 of COWAM-Spain came to the conclusion that the activity of the regulator is a key factor of long-term management. Another finding is that from a sustainability perspective multi-level governance is more effective for coping with the challenges of radioactive waste management than one tier of government-making decisions. The working group also felt that the current Local Information Committees need to evolve towards more institutionalized and legitimized mechanisms for long-term involvement. Ms. Martell introduced a study comparing the efficiency of economic instruments to advance sustainable development in nuclear communities vs. municipalities in mining areas. The study found that funds transferred to nuclear zones had become a means to facilitate local acceptance of nuclear facilities rather than a means to promote socio-economic development. Another finding is that economic instruments are not sufficient guarantees of sustainable development by themselves; additional preconditions include leadership, vision and entrepreneur-ship on the part of community leaders, private or public investments, among others. Finally, Ms. Martell summarised the challenges faced by the Spanish radioactive waste management programme, which include the need for strategic thinking, designing the future in a participatory fashion, and working with local and regional governments and citizens to devise mechanisms for social learning, economic development and environmental protection. (author)

  7. Long Term R&D for Safeguards

    International Nuclear Information System (INIS)

    Within the Office of Defense Nuclear Non-proliferation Research and Development (DNN R&D), the Nuclear Weapons and Material Security Team conducts research to develop advanced detection and source technologies for the purposes of detecting and characterizing special nuclear materials (SNM); international safeguards and radiological source replacement; nuclear arms control treaty monitoring and verification; and supporting interdiction and nuclear security efforts across NNSA. Our safeguards-specific goal is to develop and demonstrate new technologies and capabilities to cooperatively quantify and track SNM in the nuclear fuel cycle and detect any diversion of these materials for illicit purposes. Our goals and objectives align with a technology goal of the International Atomic Energy's Long Term Strategy for 2012-2023 ''to improve the Department's technical capabilities by making use of scientific and technological innovation, and to enhance its readiness to safeguard new nuclear technology and support new verification missions.'' Toward that end, we work closely with the US Department of Energy's Next Generation Safeguards Initiative and the US Support Programme to meet their specific long term needs. In this talk we will give a brief overview of current research efforts and specifically describe several helium-3 replacement technologies, advanced spent nuclear fuel characterization methods, and upcoming tags and seals technologies. We will present additional research into cross cutting enabling technologies such as advancements in detector materials, electronics, and sources, and basic physics measurements that support long term safeguards R&D. (author)

  8. Long-Term Solar Irradiance Variability

    Science.gov (United States)

    Pap, J. M.

    1996-01-01

    Measurements of the solar energy throughout the solar spectrum and understanding its variability provide important information about the physical processes and structural changes in the solar interior and in the solar atmosphere...The aim of this paper is to discuss the solar-cycle-related long-term changes in solar total and UV irradiances. The spaceborne irradiance observations are compared to ground-based indices of solar magnetic activity, such as the Photometric Sunspot Index, full disk magnetic flux, and the Mt. Wilson Magnetic Plage Strength Index.

  9. Long-term plant availability of actinides

    International Nuclear Information System (INIS)

    Environmental releases of actinide elements raise issues about which data are very limited. Quantitative information is required to assess the long-term behavior of actinides and their potential hazards resulting from the transport through food chains leading to man. Of special interest is the effect of time on the changes in the availability of actinide elements for uptake by plants from soil. This study provides valuable information on the effects of weathering and aging on the uptake of actinides from soil by range and crop plants grown under realistic field conditions

  10. Long-term economic development problems

    International Nuclear Information System (INIS)

    The long-term economic development of New Mexico parallels the major energy issue of the nation - the impact of non-proliferation policy. The short lifespan and waste of energy resources in this country reflects a lack of foresight which can no longer be tolerated. The principal unknowns affecting uranium development in New Mexico are the extent and demand for uranium, the nuclear fuel cycle, and the lifespan of nuclear power plants, with or without reprocessing. Further areas of concern include the costs of reprocessing facilities, the evaluation of fuel cycles to minimize proliferation, and the impacts of waste disposal

  11. Long-term effects of class size

    OpenAIRE

    Fredriksson, P.; Öckert, B.; Oosterbeek, H.

    2013-01-01

    This article evaluates the long-term effects of class size in primary school. We use rich data from Sweden and exploit variation in class size created by a maximum class size rule. Smaller classes in the last three years of primary school (age 10 to 13) are beneficial for cognitive and noncognitive ability at age 13, and improve achievement at age 16. Most important, we find that smaller classes have positive effects on completed education, wages, and earnings at age 27 to 42. The estimated w...

  12. Long-term effects of class size

    OpenAIRE

    Fredriksson, Peter; Öckert, Björn; Oosterbeek, Hessel

    2012-01-01

    This paper evaluates the long-term effects of class size in primary school. We use rich administrative data from Sweden and exploit variation in class size created by a maximum class size rule. Smaller classes in the last three years of primary school (age 10 to 13) are not only beneficial for cognitive test scores at age 13 but also for non-cognitive scores at that age, for cognitive test scores at ages 16 and 18, and for completed education and wages at age 27 to 42. The estimated effect on...

  13. Human Behaviour in Long-Term Missions

    Science.gov (United States)

    1997-01-01

    In this session, Session WP1, the discussion focuses on the following topics: Psychological Support for International Space Station Mission; Psycho-social Training for Man in Space; Study of the Physiological Adaptation of the Crew During A 135-Day Space Simulation; Interpersonal Relationships in Space Simulation, The Long-Term Bed Rest in Head-Down Tilt Position; Psychological Adaptation in Groups of Varying Sizes and Environments; Deviance Among Expeditioners, Defining the Off-Nominal Act in Space and Polar Field Analogs; Getting Effective Sleep in the Space-Station Environment; Human Sleep and Circadian Rhythms are Altered During Spaceflight; and Methodological Approach to Study of Cosmonauts Errors and Its Instrumental Support.

  14. Long term lithium therapy in Malaysia.

    Science.gov (United States)

    Ngen, C C; Cheong, I K

    1989-09-01

    Ten patients on long term lithium therapy (mean four years, range 1-10.5 years) were subjected to various renal, thyroid, haematological, cardiac and endocrine tests. There was impaired urinary concentrating ability in seven subjects, which was not responsive to vasopressin stimulation, suggesting a partial nephrogenic diabetes insipidus. Nine subjects had metabolic acidosis with higher urinary pH than expected suggesting presence of acidification defect in the kidney. No significant change in renal function, thyroid function, ECG or haematological parameters were detected. Our findings concur with previous reports from the West regarding the safety of lithium administration. PMID:2626134

  15. Long term prisoners’ accounts of their sentence

    OpenAIRE

    Schinkel, Marguerite Lucile

    2013-01-01

    This thesis examines how long-term prisoners make sense of their sentence: what they see as its purpose, whether they think it fair and how they integrate their sentence in their life story. Its findings are based on narrative interviews with six men at the start of their sentence, twelve men who were about to be released and nine men who were under supervision in the community. The men interviewed felt the prison largely failed in its purposes of reform, rehabilitation and det...

  16. Establishment of a cohort for the long-term clinical follow-up with dose reconstruction under the joint medical research project conducted by Sasakawa Memorial Health Foundation (Japan) and the Research Institute of Radiation Hygiene (Russia)

    International Nuclear Information System (INIS)

    The cohort of children in the western districts of the Bryansk Region of Russia exposed to radiation following the Chernobyl accident is described in this paper. The cohort was selected under the Joint Medical Research Project on Dosimetry Associated with the Chernobyl Accident conducted by Sasakawa Memorial Health Foundation (SMHF, Japan) and the Research Institute of Radiation Hygiene (RIRH, Russia). The subjects of the Research Project are those people residing in the most contaminated areas of Russia who was 0 to 10 years old at the time of exposure. At the moment the cohort comprises 1210 subjects, though this number may slightly decrease in course of a follow-up in view of migration of population. Most of cohort subjects were examined on their health status within the framework of the Chernobyl Sasakawa Health and Medical Cooperation Project (CSHMCP) from 1991-1996. In view of the main findings of studies in CSHMCP were thyroid abnormalities, selection of subjects was conducted on the basis of the credible estimates of thyroid dose. Preference for subjects to be included into the cohort was defined by the availability of health examination data from previous study (1991-1996) and individual dosimetry, environmental and social data that may prove useful for reconstruction of individual dose. The primary data analyzed for subjects selection are measurements of iodine-131 in the thyroid in May-June 1986, questionnaire data on individual food habits and early measurements of radiocesium in the body of subjects made by RIRH from May to September 1986. Plausible analytical models were applied to calculate thyroid dose from available data. Previously worked out methods of thyroid dose reconstruction using early measurement data of radiocesium content in the body and questionnaire data on individual consumption of locally produced milk were reevaluated. Basing on these analytical procedures, the individual thyroid dose was ascribed to each member of the cohort. The preliminary distribution of internal radiation doses to the thyroid among subjects of the cohort is presented in the paper. The summary characteristics of dose distribution for cohort subjects seems to be reasonably credible, whereas, the individual doses to particular subjects are evaluated with essential degree of uncertainty. The further stage of dose reconstruction for a cohort study, that is now in progress, consists of reduction of these uncertainties by using additional (newly derived) questionnaire information, as well as by taking into account contribution of external radiation to thyroid dose and updating analytical procedures to interpret primary data. Finally, the distribution of subjects into several thyroid dose ranges, from 2 Gy, would be an acceptable approximation for the purposes of radiation epidemiology in a trial to access the radiation risk of developing thyroid diseases. (author)

  17. Long-term clinical outcome in patients with pineal germinoma

    International Nuclear Information System (INIS)

    We retrospectively analyzed the long-term clinical course of 10 patients with pineal germinomas to determine the best treatment modality for achieving a good outcome. Subjects were treated at the Gunma University Hospital between 1980 and 1998, given a total dose of 40-50 Gy (mean: 49 Gy) delivered under a conventional fractionation schedule. Tumors had shrunk at 20 Gy in all 10 patients. Mean follow-up was 13.5 years (162 months, range, 59 to 268 months). Five-year survival for the group was 100%. None experienced intracranial disease recurrence. No new abnormalities in internal secretion considered to be due to radiotherapy were seen. Karnofsky performance scales (KPS) for 8 of the 10 were 100. KPS of the remaining 2 were 80, including easy fatiguability, mild ataxia, and recent memory disturbance. Administration of doses of 50 Gy for pineal germinoma is adequate for controlling the tumor over the long term but may reduce the patientis quality of life. Further study is therefore needed to determine the optimal dosage for pineal germinoma. (author)

  18. Explaining Variance in Long-Term Recall in 3- and 4-Year-Old Children: The Importance of Post-Encoding Processes

    Science.gov (United States)

    Bauer, Patricia J.; Larkina, Marina; Doydum, Ayzit O.

    2012-01-01

    Long-term recall is influenced by what originally was encoded as well as by the efficacy of retrieval processes. The possible explanatory role of post-encoding processes by which initially labile memory traces are stabilized and integrated into long-term memory (i.e., consolidated) has received relatively less research attention. In the current…

  19. Toward a comprehensive long term nicotine policy.

    Science.gov (United States)

    Gray, N; Henningfield, J E; Benowitz, N L; Connolly, G N; Dresler, C; Fagerstrom, K; Jarvis, M J; Boyle, P

    2005-06-01

    Global tobacco deaths are high and rising. Tobacco use is primarily driven by nicotine addiction. Overall tobacco control policy is relatively well agreed upon but a long term nicotine policy has been less well considered and requires further debate. Reaching consensus is important because a nicotine policy is integral to the target of reducing tobacco caused disease, and the contentious issues need to be resolved before the necessary political changes can be sought. A long term and comprehensive nicotine policy is proposed here. It envisages both reducing the attractiveness and addictiveness of existing tobacco based nicotine delivery systems as well as providing alternative sources of acceptable clean nicotine as competition for tobacco. Clean nicotine is defined as nicotine free enough of tobacco toxicants to pass regulatory approval. A three phase policy is proposed. The initial phase requires regulatory capture of cigarette and smoke constituents liberalising the market for clean nicotine; regulating all nicotine sources from the same agency; and research into nicotine absorption and the role of tobacco additives in this process. The second phase anticipates clean nicotine overtaking tobacco as the primary source of the drug (facilitated by use of regulatory and taxation measures); simplification of tobacco products by limitation of additives which make tobacco attractive and easier to smoke (but tobacco would still be able to provide a satisfying dose of nicotine). The third phase includes a progressive reduction in the nicotine content of cigarettes, with clean nicotine freely available to take the place of tobacco as society's main nicotine source. PMID:15923465

  20. Long term modulation of cosmic rays

    International Nuclear Information System (INIS)

    Studies of the long term modulation of cosmic ray in interplanetary space give valuable information on the electromagnetic state in the solar magnetosphere as well as the properties of galactic cosmic ray. In the light of the Parker's diffusion-convection theory, the modulation of galactic cosmic ray can be well explained by setting proper physical states in the modulating region, but it is not clear how the physical states are related to solar activities. In this paper, it is demonstrated that the long term variation in cosmic ray intensity can be described by an integral equation, which is derived from the generalization of Simpson's coasting solar wind model. The function for cosmic ray intensity is given by some appropriate solar activity index, and the characteristic function expresses time dependence of the influence on the intensity depression due to solar disturbances when the disturbances generated by the solar activity propagate through the modulating region with the solar wind. From the integral equation with sunspot number as the solar activity index, the characteristic function for the variation with 11-year period in cosmic ray intensity is derived, using data of ionchambers and neutron monitors. (Yoshimori, M.)

  1. Optical Fiber Specifications For Long Term Maintenance

    Science.gov (United States)

    Skutnik, Bolesh J.

    1990-01-01

    In recent years the reliability of optical fibers in special environments has become of great concern in military, government and other specialty high performance applications. With the first exploratory installations of fiber-to-the-home confirming the inherent requirements for a robust optical fiber, the telecommunications market and operating companies have had to begin considering how to minimize long term maintenance of optical fiber systems, which are subjected to a much broader range of dangers than in long haul or station to station installations. This paper discusses some background information on the strength and fatigue of optical fibers/cables, their reliability issues and several points concerning design and lifetime predictions for such components/systems. It includes information on standards efforts in fiber reliability and environmental testing as well as on SPIE efforts to present up-to-date information on these topic areas. Its intent is to point out problem areas for long term maintenance and present current approaches to minimize these problems rather than present solutions.

  2. Long-term environmental behaviour of radionuclides

    International Nuclear Information System (INIS)

    The radioactive pollution of the environment results from the atmospheric nuclear weapons testing (during the mid-years of twentieth century), from the development of the civilian nuclear industry and from accidents such as Chernobyl. Assessing the resulting radiation that humans might receive requires a good understanding of the long-term behaviour of radionuclides in the environment. This document reports on a joint European effort to advance this understanding, 3 multinational projects have been coordinated: PEACE, EPORA and LANDSCAPE. This report proposes an overview of the results obtained and they are presented in 6 different themes: i) redistribution in the soil-plant system, ii) modelling, iii) countermeasures, iv) runoff v) spatial variations, and vi) dose assessment. The long term behaviour of the radionuclides 137Cs, 90Sr and 239-240Pu is studied through various approaches, these approaches range from in-situ experiments designed to exploit past contamination events to laboratory simulations. A broad scope of different ecosystems ranging from arctic and boreal regions down to mediterranean ones has been considered. (A.C.)

  3. Long term perfusion system supporting adipogenesis.

    Science.gov (United States)

    Abbott, Rosalyn D; Raja, Waseem K; Wang, Rebecca Y; Stinson, Jordan A; Glettig, Dean L; Burke, Kelly A; Kaplan, David L

    2015-08-01

    Adipose tissue engineered models are needed to enhance our understanding of disease mechanisms and for soft tissue regenerative strategies. Perfusion systems generate more physiologically relevant and sustainable adipose tissue models, however adipocytes have unique properties that make culturing them in a perfusion environment challenging. In this paper we describe the methods involved in the development of two perfusion culture systems (2D and 3D) to test their applicability for long term in vitro adipogenic cultures. It was hypothesized that a silk protein biomaterial scaffold would provide a 3D framework, in combination with perfusion flow, to generate a more physiologically relevant sustainable adipose tissue engineered model than 2D cell culture. Consistent with other studies evaluating 2D and 3D culture systems for adipogenesis we found that both systems successfully model adipogenesis, however 3D culture systems were more robust, providing the mechanical structure required to contain the large, fragile adipocytes that were lost in 2D perfused culture systems. 3D perfusion also stimulated greater lipogenesis and lipolysis and resulted in decreased secretion of LDH compared to 2D perfusion. Regardless of culture configuration (2D or 3D) greater glycerol was secreted with the increased nutritional supply provided by perfusion of fresh media. These results are promising for adipose tissue engineering applications including long term cultures for studying disease mechanisms and regenerative approaches, where both acute (days to weeks) and chronic (weeks to months) cultivation are critical for useful insight. PMID:25843606

  4. Craniopharyngioma in Children: Long-term Outcomes.

    Science.gov (United States)

    Steinbok, Paul

    2015-09-15

    The survival rate for childhood craniopharyngioma has been improving, with more long-term survivors. Unfortunately it is rare for the patient to be normal, either from the disease itself or from the effects of treatment. Long-term survivors of childhood craniopharyngioma suffer a number of impairments, which include visual loss, endocrinopathy, hypothalamic dysfunction, cerebrovascular problems, neurologic and neurocognitive dysfunction. Pituitary insufficiency is present in almost 100%. Visual and hypothalamic dysfunction is common. There is a high risk of metabolic syndrome and increased risk of cerebrovascular disease, including stroke and Moyamoya syndrome. Cognitive, psychosocial, and emotional problems are prevalent. Finally, there is a higher risk of premature death among survivors of craniopharyngioma, and often this is not from tumor recurrence. It is important to consider craniopharyngioma as a chronic disease. There is no perfect treatment. The treatment has to be tailored to the individual patient to minimize dysfunction caused by tumor and treatments. So "cure" of the tumor does not mean a normal patient. The management of the patient and family needs multidisciplinary evaluation and should involve ophthalmology, endocrinology, neurosurgery, oncology, and psychology. Furthermore, it is also important to address emotional issues and social integration. PMID:26345668

  5. Long term testing of PSI-membranes

    Energy Technology Data Exchange (ETDEWEB)

    Huslage, J.; Brack, H.P.; Geiger, F.; Buechi, F.N.; Tsukada, A.; Scherer, G.G. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Long term tests of PSI membranes based on radiation-grafted FEP and ETFE films were carried out and FEP-based membranes were evaluated by monitoring the in-situ membrane area resistance measured by a current pulse method. By modifying our irradiation procedure and using the double crosslinking concept we obtain reproducible membrane cell lifetimes (in term of in-situ membrane resistance) of greater than 5000 hours at 60-65{sup o}C. Preliminary tests at 80-85{sup o}C with lifetimes of greater than 2500 demonstrate the potential long term stability of PSI proton exchange membranes based on FEP over the whole operating temperature range of low-temperature polymer electrolyte fuel cells. Radiation grafted PSI membranes based on ETFE have better mechanical properties than those of the FEP membranes. Mechanical properties are particularly important in large area cells and fuel cell stacks. ETFE membranes have been tested successfully for approximately 1000 h in a 2-cell stack (100 cm{sup 2} active area each cell). (author) 4 figs., 4 refs.

  6. Long-term environmental behaviour of radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Brechignac, F.; Moberg, L.; Suomela, M

    2000-04-01

    The radioactive pollution of the environment results from the atmospheric nuclear weapons testing (during the mid-years of twentieth century), from the development of the civilian nuclear industry and from accidents such as Chernobyl. Assessing the resulting radiation that humans might receive requires a good understanding of the long-term behaviour of radionuclides in the environment. This document reports on a joint European effort to advance this understanding, 3 multinational projects have been coordinated: PEACE, EPORA and LANDSCAPE. This report proposes an overview of the results obtained and they are presented in 6 different themes: (i) redistribution in the soil-plant system, (ii) modelling, (iii) countermeasures, (iv) runoff (v) spatial variations, and (vi) dose assessment. The long term behaviour of the radionuclides {sup 137}Cs, {sup 90}Sr and {sup 239-240}Pu is studied through various approaches, these approaches range from in-situ experiments designed to exploit past contamination events to laboratory simulations. A broad scope of different ecosystems ranging from arctic and boreal regions down to mediterranean ones has been considered. (A.C.)

  7. The long term radioactive storage alternative

    International Nuclear Information System (INIS)

    With uncertainty regarding the Yucca Mountain geologic repository being just one manifestation of the controversy over where, how, and whether radioactive waste can be safely treated and disposed in a publicly acceptable manner, the authors suggest that a new approach regarding the storage of spent nuclear fuel (SNF) and radioactive waste is needed and, fortunately, available. Safely storing wastes in an environmentally-acceptable, monitored manner while a national political and technical consensus is reached on how to properly treat it prior to its ultimate disposal may be the most cost-effective and rational method of addressing these issues in the interim. Because of the limitations imposed on treatment and disposal options by state governments, legislative and regulatory requirements, and legal challenges, spent fuel, other reactor irradiated nuclear material (RINM), and radioactive waste are remaining where they were produced, usually in facilities neither sited nor designed with long-term storage in mind. The inertia associated with difficult choices based on imperfect information has resulted in a decision-making gridlock where an unpopular status quo continues and promising solutions remain untried. However, well-planned and locally accepted centralization of wastes (especially medical) within states and/or acceptance of dry spent fuel storage at each nuclear generating station can break the current gridlock of disposal and storage actions and inactions and can result in a more desirable outcome both in the intermediate and long term

  8. Institutionalization and Organizational Long-term Success

    Directory of Open Access Journals (Sweden)

    Denise L. Fleck

    2007-05-01

    Full Text Available Institutionalization processes have an ambivalent effect on organizational long-term success. Even though they foster organizational stability and permanence, they also bring about rigidity and resistance to change. As a result, successful organizations are likely to lose their competitive advantage over time. The paper addresses this issue through the investigation of the institutionalization processes of two long-lived companies: General Electric, a firm that has been a long-term success and its rival, Westinghouse, which was broken up after eleven decades of existence. The longitudinal, multilevel analysis of firms and industry has identified two different modes of organizational institutionalization. The reactive mode gives rise to rigidity and change resistance, much like institutional theory predicts; the proactive mode, on the other hand, neutralizes those negative effects of institutionalization processes. In the reactive mode, structure predominates. In the proactive mode, agency plays a major role in organizational institutionalization, and in managing the organization’s relations with the environment, clearly contributing to environmental institutionalization.

  9. Institutionalization and organizational long-term success

    Scientific Electronic Library Online (English)

    Denise, Fleck.

    2007-08-01

    Full Text Available Institutionalization processes have an ambivalent effect on organizational long-term success. Even though they foster organizational stability and permanence, they also bring about rigidity and resistance to change. As a result, successful organizations are likely to lose their competitive advantage [...] over time. The paper addresses this issue through the investigation of the institutionalization processes of two long-lived companies: General Electric, a firm that has been a long-term success and its rival, Westinghouse, which was broken up after eleven decades of existence. The longitudinal, multilevel analysis of firms and industry has identified two different modes of organizational institutionalization. The reactive mode gives rise to rigidity and change resistance, much like institutional theory predicts; the proactive mode, on the other hand, neutralizes those negative effects of institutionalization processes. In the reactive mode, structure predominates. In the proactive mode, agency plays a major role in organizational institutionalization, and in managing the organization's relations with the environment, clearly contributing to environmental institutionalization.

  10. Memory Networks

    OpenAIRE

    Weston, Jason; Chopra, Sumit; Bordes, Antoine

    2014-01-01

    We describe a new class of learning models called memory networks. Memory networks reason with inference components combined with a long-term memory component; they learn how to use these jointly. The long-term memory can be read and written to, with the goal of using it for prediction. We investigate these models in the context of question answering (QA) where the long-term memory effectively acts as a (dynamic) knowledge base, and the output is a textual response. We evalu...

  11. Health-related quality of life in long-term breast cancer survivors

    DEFF Research Database (Denmark)

    Peuckmann, Vera; Ekholm, Ola; Rasmussen, Niels Kristian; Møller, Susanne; Groenvold, Mogens; Christiansen, Peer; Eriksen, Jørgen; Sjøgren, Per

    2007-01-01

    AIM: To investigate health-related quality of life (HRQOL) in a nationally representative sample of long-term breast cancer survivors (BCS) in Denmark. PARTICIPANTS AND METHODS: An age-stratified random sample of 2,000 female BCS > or = 5 years after primary surgery without recurrence was drawn from the Danish Breast Cancer Cooperative Group register, which is representative regarding long-term BCS in Denmark, and compared with 3,104 women of the nationally representative Danish Health and Morbi...

  12. Assessing Long-term Reliability of Polymeric Housing Materials

    Science.gov (United States)

    Miyake, Takuma; Arata, Yoshihiro; Sakoda, Tatsuya; Otsubo, Masahisa; Sonoda, Yasufumi; Yamaguchi, Hiroshi

    Application of polymeric materials for housing of outdoor insulators is expected to rapidly increase in the near future. However, the lifetime and the aging deterioration, owing to environmental conditions, are concerned. To understand the long-term reliability of the insulation performance of polymeric materials, the salt fog tests were performed on the polymeric insulators made of ethylene vinyl acetate (EVA) and silicone rubber (SiR). The hydrophobicity was also evaluated. The samples which 11 years have passed since the installation were taken away from an actual distribution system in the region where pollution condition was comparatively severe. The results indicated that the polymeric insulators had enough insulation performance.

  13. Effects of Long-Term Representations on Free Recall of Unrelated Words

    Science.gov (United States)

    Katkov, Mikhail; Romani, Sandro; Tsodyks, Misha

    2015-01-01

    Human memory stores vast amounts of information. Yet recalling this information is often challenging when specific cues are lacking. Here we consider an associative model of retrieval where each recalled item triggers the recall of the next item based on the similarity between their long-term neuronal representations. The model predicts that…

  14. Effects of Spaced Repetition on Long-Term Map Knowledge Recall

    Science.gov (United States)

    Zirkle, David M.; Ellis, Arthur K.

    2010-01-01

    Sixth-grade students studying Latin America were placed in experimental and comparison groups to test the effects of map-study repetition on long-term memory. Mean scores on place-name repetition indicated that the experimental (repetition) group out-performed the comparison group at a statistically significant level with respect to both posttest…

  15. Sistemas de memoria: reseña histórica, clasificación y conceptos actuales. Primera parte: Historia, taxonomía de la memoria, sistemas de memoria de largo plazo: la memoria semántica / Memory systems: historical background, classification, and current concepts. Part one: History, taxonomy of memory, long-term memory systems: Semantic memory

    Scientific Electronic Library Online (English)

    Paul, Carrillo-Mora.

    2010-02-01

    Full Text Available La memoria es una función cerebral fascinante, mediante ella el Sistema Nervioso codifica, almacena, organiza y recupera una gran variedad de tipos de información que resultan de vital importancia para el individuo en particular. Los conocimientos actuales nos permiten conceptualizar a la memoria co [...] mo conformada por una red compleja de subsistemas de memoria que pueden trabajar en paralelo, cooperando e incluso en ocasiones funcionar de forma competitiva entre sí. La evolución de la clasificación de los sistemas de memoria se ha desarrollado en paralelo al conocimiento acerca del funcionamiento del los procesos mnésicos. Las primeras aproximaciones al estudio de la memoria estaban conformadas por métodos filosóficos que comprendían la observación, reflexión, lógica, etc. En el siglo XIX surgieron los primeros estudios científicos para el estudio experimental de la memoria. Autores como Ebbinghaus o Lashley estudiaron por primera vez la memoria humana y animal respectivamente. Los conductistas como Pavlov, Skinner, Thorndike y Watson sentaron las bases del aprendizaje asociativo que conocemos como condicionamiento clásico y condicionamiento operante. Más tarde los estudios neuropsicológicos de pacientes con lesiones quirúrgicas focales temporales arrojaron resultados contundentes acerca del sustrato anatómico de la memoria declarativa en el lóbulo temporal, lo que inició una avalancha de estudios y descripciones neuropsicológicas cada vez más finas sobre las consecuencias de las lesiones y patologías cerebrales en los distintos procesos de memoria. Más recientemente, los estudios de los procesos celulares y moleculares de las formas de aprendizaje más elementales (habituación y sensibilización) en modelos de animales invertebrados han demostrado los requerimientos celulares mínimos para el establecimiento del aprendizaje así como los mecanismos moleculares diferenciales involucrados en la memoria de corto y largo plazo. A últimas fechas, la introducción de los estudios de neuroimagen funcional en pacientes enfermos y sanos ha permitido la expansión de los conocimientos sobre el funcionamiento dinámico y en tiempo real de los diversos procesos de memoria. En la actualidad la clasificación más aceptada de los sistemas de memoria de largo plazo considera dos grandes esferas principales: la memoria declarativa y la no declarativa. La memoria declarativa se refiere a la que contiene información de la cual se tiene un registro consciente y que se puede verbalizar o transmitir fácilmente a través de algún medio a otro individuo. La memoria no declarativa comprende información que no se puede verbalizar fácilmente o cuyo aprendizaje puede ser inconsciente e incluso involuntario. La memoria declarativa se subdivide en memoria semántica y episódica. El ámbito de la memoria semántica es la información almacenada acerca de las características y atributos que definen los conceptos (hechos que carecen de un marco espacio temporal definido), así como los procesos que permiten su recuperación de forma eficiente para su utilización en el pensamiento y el lenguaje actual. Los estudios de imagen funcional han demostrado que la información sobre las características de objetos específicos que es necesaria para la generación de conceptos es almacenada dentro de los mismos sistemas neuronales que están activos durante la percepción de esos mismos estímulos. El rol del lóbulo temporal en esta variedad de memoria está comprobado por estudios experimentales y clínicos, pero los estudios de imagen funcional han demostrado otras áreas asociadas a la codificación y recuperación semántica cuyo papel aún no ha sido comprendido por completo. Abstract in english Memory is a fascinating brain function by means of which the nervous system can codify, store, organize, and recover a variety of information relevant to the subject. The formal study of memory started more than a century ago, providing in this time a considerable amount of scientific information on [...]

  16. Ammonia Inhibits Long-term Potentiation via Neurosteroid Synthesis in Hippocampal Pyramidal Neurons

    OpenAIRE

    Izumi, Yukitoshi; Svrakic, Neda; O’Dell, Kazuko; Zorumski, Charles F.

    2012-01-01

    Neurosteroids are a class of endogenous steroids synthesized in the brain that are believed to be involved in the pathogenesis of neuropsychiatric disorders and memory impairment. Ammonia impairs long-term potentiation (LTP), a synaptic model of learning, in the hippocampus, a brain region involved in memory acquisition. Although mechanisms underlying ammonia-mediated LTP inhibition are not fully understood, we previously found that activation of N-methyl-D-aspartate receptors (NMDARs) is imp...

  17. Accelerated long-term forgetting in transient epileptic amnesia: an acquisition or consolidation deficit?

    OpenAIRE

    Hoefeijzers, S; Dewar, M.; Della Sala, S; Zeman, A.; Butler, C.

    2013-01-01

    Accelerated Long-term Forgetting (ALF) is the rapid loss of newly acquired memories over days to weeks despite normal retention at standard (~30 min) intervals. It has recently been described in association with epilepsy, particularly the syndrome of Transient Epileptic Amnesia (TEA). The cognitive mechanisms underlying ALF remain uncertain, but disruption either of memory acquisition or consolidation processes has been postulated. To arbitrate between these accounts, we reanalysed data from ...

  18. Opposing actions of chronic ?9-tetrahydrocannabinol and cannabinoid antagonists on hippocampal long-term potentiation

    OpenAIRE

    Hoffman, Alexander F; Oz, Murat; Yang, Ruiqin; Lichtman, Aron H; Lupica, Carl R

    2007-01-01

    Memory deficits produced by marijuana arise partly via interaction of the psychoactive component, ?9-tetrahydrocannabinol (?9-THC), with cannabinoid receptors in the hippocampus. Although cannabinoids acutely reduce glutamate release and block hippocampal long-term potentiation (LTP), a potential substrate for learning and memory, the consequences of prolonged exposure to ?9-THC for hippocampal function are poorly understood. Rats were injected with ?9-THC (10 mg/kg, i.p., q.d.) for 1, 3, or ...

  19. Seasonal variation of long-term potentiation at a central synapse in the medicinal leech

    OpenAIRE

    Grey, Kathryn B.; Burrell, Brian D

    2011-01-01

    Long-term potentiation (LTP) is a persistent increase in synaptic transmission that is thought to contribute to a variety of adaptive processes including learning and memory. Although learning is known to undergo circannual variations, it is not known whether LTP undergoes similar changes despite the importance of LTP in learning and memory. Here we report that synapses in the CNS of the medicinal leech demonstrate seasonal variation in the capacity to undergo LTP following paired presynaptic...

  20. Reversal of Long-Term Potentiation-Like Plasticity Processes after Motor Learning Disrupts Skill Retention

    OpenAIRE

    Cantarero, Gabriela; Lloyd, Ashley; Celnik, Pablo

    2013-01-01

    Plasticity of synaptic connections in the primary motor cortex (M1) is thought to play an essential role in learning and memory. Human and animal studies have shown that motor learning results in long-term potentiation (LTP)-like plasticity processes, namely potentiation of M1 and a temporary occlusion of additional LTP-like plasticity. Moreover, biochemical processes essential for LTP are also crucial for certain types of motor learning and memory. Thus, it has been speculated that the occlu...

  1. Long-term behaviour of photovoltaic installations

    International Nuclear Information System (INIS)

    This article presents and discusses the results obtained from the long-term monitoring of grid-connected photovoltaic (PV) installations that has been carried out since 1992 by the University of Applied Science in Burgdorf, Switzerland. Most of the 42 installations monitored were located near Burgdorf, but plant located in alpine regions, the 'Mont Soleil' PV plant in the Jura mountains and three more recent installations using thin-film cells were also monitored. The article discusses inverter reliability and presents failure statistics in table form. The evolution of specific energy yield for the various installations is examined. Also, the degradation of the photovoltaic laboratory's own PV installation caused by soiling and ageing of the panels is discussed

  2. Long-term nuclear power optimization study

    International Nuclear Information System (INIS)

    An energy demand forecasting model, energy systems optimization model and optimal electrical expansion planning model of the Republic of Korea are developed. Using the first model of them, long-term energy and electric power demand to the year 2001 are forcasted, using the second model, the future energy systems especially for the reference year 1981 are analyzed and optimal energy flows are computed through possible energy supply-demand paths. Also, using the third model, the future nuclear power strategies are analyzed by the optimizing total investment costs for different nuclear reaction combination, assuming that there will be three available reactor types, namely, light water reactor, heavy water reactor and fast breeder reactor up to the year 2000 in Korea. (KAERI INIS Section)

  3. Hanford grout: predicting long-term performance

    International Nuclear Information System (INIS)

    Grouted disposal is being planned for the low-level portion of liquid radioactive wastes at the Hanford site in Washington state. The performance of the disposal system must be such that it will protect people and the environment for thousands of years after disposal. To predict whether a specific grout disposal system will comply with existing and foreseen regulations, a performance assessment (PA) is performed. Long-term PAs are conducted for a range of performance conditions. Performance assessment is an inexact science. Quantifying projected impacts is especially difficult when only scant data exist on the behavior of certain components of the disposal system over thousands of years. To develop defensible results, we are honing the models and obtaining experimental data. The combination of engineered features and PA refinements is being used to ensure that Hanford grout will meet its principal goal: to protect people and the environment in the future

  4. A long-term programme for IAEA

    International Nuclear Information System (INIS)

    At its fifth regular session in 1961, the IAEA General Conference adopted a resolution calling for the preparation of a long-term programme for the Agency's activities. The programme, which was prepared after extensive consultations with experts from many Member States and is intended to serve as a guide in planning and carrying out the Agency's work from 1965, has been presented to the seventh session of the General Conference by the Board of Governors and the Director General. It envisages that the Agency's main role during the next few years will be, on the one hand, to assist in preparing Member States for the introduction of atomic energy in its various peaceful uses, especially in the production of power, and, on the other, to stimulate and co-ordinate scientific and technological development with a view to making the advantages of peaceful atomic applications available to the maximum number of countries in the shortest possible time

  5. Managing Records for the Long Term - 12363

    International Nuclear Information System (INIS)

    The U.S. Department of Energy (DOE) is responsible for managing vast amounts of information documenting historical and current operations. This information is critical to the operations of the DOE Office of Legacy Management. Managing legacy records and information is challenging in terms of accessibility and changing technology. The Office of Legacy Management is meeting these challenges by making records and information management an organizational priority. The Office of Legacy Management mission is to manage DOE post-closure responsibilities at former Cold War weapons sites to ensure the future protection of human health and the environment. These responsibilities include environmental stewardship and long-term preservation and management of operational and environmental cleanup records associated with each site. A primary organizational goal for the Office of Legacy Management is to 'Preserve, Protect, and Share Records and Information'. Managing records for long-term preservation is an important responsibility. Adequate and dedicated resources and management support are required to perform this responsibility successfully. Records tell the story of an organization and may be required to defend an organization in court, provide historical information, identify lessons learned, or provide valuable information for researchers. Loss of records or the inability to retrieve records because of poor records management processes can have serious consequences and even lead to an organisation's downfall. Organizations must invest time and resources to establish a good records management program because of its significance to the organization as a whole. The Office of Legacy Management will continue to research and apply innovative ways of doing business to ensure that the organization stays at the forefront of effective records and information management. DOE is committed to preserving records that document our nation's Cold War legacy, and the Office of Legacy Management will keep records management as a high priority. (authors)

  6. Long term radiological impact of thorium extraction

    International Nuclear Information System (INIS)

    Thorium extraction produces a certain amount of radioactive wastes. Potential long term radiological impact of these residues has been calculated using the recent ICRP-68 ingestion dose factors in connection with the computing code DECAY, developed at Orsay and described in this work. This code solves the well known Bateman's equations which govern the time dependence of a set of coupled radioactive nuclei. Monazites will be very likely the minerals to be exploited first, in case of an extensive use of thorium as nuclear fuel. Because monazites contain uranium as well, mining residues will contain not only the descendants of 232Th and a certain proportion of non-extracted thorium (taken here to be 5%), but also this uranium, if left in the wastes for economical reasons. If no uranium would be present at all in the mineral, the potential radiotoxicity would strongly decrease in approximately 60 years, at the pace of the 5.8 years period of 228Ra, which becomes the longest-lived radionuclide of the 4n radioactive family in the residues. Moreover, there is no risk due to radon exhalation, because of the very short period of 220Rn. These significant differences between uranium and thorium mining have to be considered in view of some estimated long term real radiological impacts due to uranium residues, which could reach a value of the order of 1 mSv/year, the dose limit recommended for the public by the recent ICRP-60. (authors). 15 refs., 4 figs., 3 tabs., 43 appendices

  7. Long-term reductions in tinnitus severity

    Directory of Open Access Journals (Sweden)

    Folmer Robert L

    2002-09-01

    Full Text Available Abstract Background This study was undertaken to assess long-term changes in tinnitus severity exhibited by patients who completed a comprehensive tinnitus management program; to identify factors that contributed to changes in tinnitus severity within this population; to contribute to the development and refinement of effective assessment and management procedures for tinnitus. Methods Detailed questionnaires were mailed to 300 consecutive patients prior to their initial appointment at the Oregon Health & Science University Tinnitus Clinic. All patients were then evaluated and treated within a comprehensive tinnitus management program. Follow-up questionnaires were mailed to the same 300 patients 6 to 36 months after their initial tinnitus clinic appointment. Results One hundred ninety patients (133 males, 57 females; mean age 57 years returned follow-up questionnaires 6 to 36 months (mean = 22 months after their initial tinnitus clinic appointment. This group of patients exhibited significant long-term reductions in self-rated tinnitus loudness, Tinnitus Severity Index scores, tinnitus-related anxiety and prevalence of current depression. Patients who improved their sleep patterns or Beck Depression Inventory scores exhibited greater reductions of tinnitus severity scores than patients who continued to experience insomnia and depression at follow-up. Conclusions Individualized tinnitus management programs that were designed for each patient contributed to overall reductions in tinnitus severity exhibited on follow-up questionnaires. Identification and treatment of patients experiencing anxiety, insomnia or depression are vital components of an effective tinnitus management program. Utilization of acoustic therapy also contributed to improvements exhibited by these patients.

  8. GEOPOLYMER MATERIALS ON THE FLYASH BASIS – LONG-TERM PROPERTIES

    Directory of Open Access Journals (Sweden)

    FRANTIŠEK ŠKVÁRA

    2014-03-01

    Full Text Available The influence of the external environment on the properties of geopolymers on the basis of fly ashes exposed to various conditions (environments of different humidity levels, autoclave, dry conditions at 80°C, immersed in water has been investigated for two years. The strength values of geopolymers kept under various conditions do not drop during the period of two years. The maximum values could be achieved if the geopolymers were kept under dry conditions at 80°C and in the air at a relative humidity ranging from 40 to 50 percent. The strength values do not change practically if the geopolymers are kept in water, in an autoclave or in an environment with the relative humidity of 95 percent. The long-term exposure of fly ash-based geopolymers does not result in any change in their microstructure and practically no new phases arise. The exposure to water is accompanied by a gradual leaching of sodium until its almost complete transition to water. The exposure of geopolymers to alternating humid and dry conditions gives rise to efflorescences. The NMR 23Na, 27Al and 29Si spectra of fly ash-based geopolymers revealed a practically unchanged occurrence of structures in samples after their long-term exposure to various conditions as compared with the initial structures. Practically no evidence (X-ray diffraction and IR analyses of any formation of new phases after various exposure conditions. No significant morphological changes (the formation of crystalline phases in samples kept under above mentioned conditions could be identified after two years as compared to the initial state; hence, the original amorphous character of the geopolymers is preserved. The structure of man-made geopolymers can probably be deduced rather from the amorphous mineral allophane than from crystaline zeolites. Therefore, thanks to a comprehensive long-term investigation, the fly ash-based geopolymers can be regarded as stable hydraulic binders.

  9. Comparison of long-term care in an acute care institution and in a long-term care institution

    OpenAIRE

    Friedman, R.; Kalant, N

    1998-01-01

    BACKGROUND: Acute care hospitals in Quebec are required to reserve 10% of their beds for patients receiving long-term care while awaiting transfer to a long-term care facility. It is widely believed that this is inefficient because it is more costly to provide long-term care in an acute care hospital than in one dedicated to long-term care. The purpose of this study was to compare the quality and cost of long-term care in an acute care hospital and in a long-term care facility. METHODS: A con...

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

    Scientific Electronic Library Online (English)

    Timothy V.P., Bliss; Sam F., Cooke.

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

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

    Directory of Open Access Journals (Sweden)

    Timothy V.P. Bliss

    2011-01-01

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

  12. Does “Long-Term Compensation” Make CEOs Think Long-Term? A Study of CEO Compensation in the Commercial Banking Industry

    Directory of Open Access Journals (Sweden)

    Ryan Krause

    2009-04-01

    Full Text Available The issue of CEO compensation has become a controversial staple of media dialogue and academic pondering, especially after a crisis such as the 2007 mortgage market meltdown. CEOs, through stock options, stock grants, and cash bonuses, are supposedly paid to maximize long-term shareholder value. This desired result, however, often fails to come to fruition. In this study, from a sample of twenty-seven US commercial banks, I look for a correlation between the share of a CEO’s compensation that is designated “long-term” and two metrics of effective long-term strategy. I find no statistically significant evidence to suggest that the long-term portion of a CEO’s pay is correlated with the percentage change in either a bank’s net income or its allowance for loan losses, taken as a percentage of total loans. Nevertheless, I do find some evidence that long-term compensation plans that incorporate preset performance goals may improve the chances of long-term stability.

  13. Tiagabine Improves Hippocampal Long-Term Depression in Rat Pups Subjected to Prenatal Inflammation

    Science.gov (United States)

    Rideau Batista Novais, Aline; Crouzin, Nadine; Cavalier, Mélanie; Boubal, Mathilde; Guiramand, Janique; Cohen-Solal, Catherine; de Jesus Ferreira, Marie-Céleste; Cambonie, Gilles; Vignes, Michel; Barbanel, Gérard

    2014-01-01

    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 and 25 postnatal days instead of after the first postnatal month, and aberrant occurrence of long-term potentiation. We hypothesized this would be related to GABAergic system impairment. Sprague Dawley rats received either LPS or isotonic saline ip on gestational day 19. Male offspring's hippocampus was studied between 12 and 25 postnatal days. Morphological and functional analyses demonstrated that prenatal LPS triggered a deficit of hippocampal GABAergic interneurons, associated with presynaptic GABAergic transmission deficiency in male offspring. Increasing ambient GABA by impairing GABA reuptake with tiagabine did not interact with the low frequency-induced long-term depression in control animals but fully prevented its impairment in male offspring of LPS-challenged dams. Tiagabine furthermore prevented the aberrant occurrence of paired-pulse triggered long-term potentiation in these rats. Deficiency in GABA seems to be central to the dysregulation of synaptic plasticity observed in juvenile in utero LPS-challenged rats. Modulating GABAergic tone may be a possible therapeutic strategy at this developmental stage. PMID:25184226

  14. Efficient quantum memory using a weakly absorbing sample

    CERN Document Server

    Sabooni, Mahmood; Kröll, Stefan; Rippe, Lars

    2013-01-01

    A light-storage experiment with a total (storage and retrieval) efficiency $\\eta=58 \\pm 5%$ is carried out by enclosing a sample, with a single pass absorption of 10%, in an impedance-matched cavity. The experiment is carried out using the Atomic Frequency Comb (AFC) technique in a praseodymium-doped crystal ($0.05%Pr^{3+}:Y_2SiO_5$) and the cavity is created by reflection coating the crystal surfaces. The AFC technique has previously by far demonstrated the highest multi-mode capacity of all quantum memory concepts tested experimentally. We claim that the present work shows that it is realistic to create efficient, on-demand, long storage time AFC memories.

  15. Efficient Quantum Memory Using a Weakly Absorbing Sample

    Science.gov (United States)

    Sabooni, Mahmood; Li, Qian; Kröll, Stefan; Rippe, Lars

    2013-03-01

    A light-storage experiment with a total (storage and retrieval) efficiency ?=56% is carried out by enclosing a sample, with a single-pass absorption of 10%, in an impedance-matched cavity. The experiment is carried out using the atomic frequency comb (AFC) technique in a praseodymium-doped crystal (0.05%Pr3+?Y2SiO5) and the cavity is created by depositing reflection coatings directly onto the crystal surfaces. The AFC technique has previously by far demonstrated the highest multimode capacity of all quantum memory concepts tested experimentally. We claim that the present work shows that it is realistic to create efficient, on-demand, long storage time AFC memories.

  16. Evaluating Long-Term Care Through the Humanbecoming Lens.

    Science.gov (United States)

    Hart, Judith D

    2015-10-01

    The author describes evaluating long-term care from the humanbecoming perspective. Three core ideas are presented related to dignity and living quality, and how the humanbecoming perspective can be incorporated into long-term care evaluations that make a difference to the residents, caregivers, management, and to the outcomes of long-term care. This approach from the humanbecoming perspective can enrich evaluative information, influence long-term care outcomes, and ensure human dignity for all concerned. PMID:26396210

  17. Nuclear plant models for medium- to long-term power system stability studies

    International Nuclear Information System (INIS)

    CRIEPI and EPRI have jointly developed PWR and BWR nuclear power plant models for medium- to long-term power system dynamic simulation studies, which are being implemented for EPRI's and CRIEPI's long-term stability programs respectively. The models are extended versions of CRIEPI's previous one for short-term simulation. The models are useful in simulating the plant dynamics taking into account responses of the plant control and protection systems. The paper presents functional specification of the models, overall model description, newly included models for medium- to long-term studies and sample simulation results

  18. Experimental evidence on the long term impacts of a youth training program

    OpenAIRE

    Ibarrarán, Pablo; Kluve, Jochen; Ripani, Laura; Shady, David Rosas

    2015-01-01

    This paper presents the results of a randomized controlled trial on the long-term impacts of a youth training program. The empirical analysis estimates labor market impacts six years after the training - including long-term labor market trajectories of young people - and, to the best of our knowledge, is the first experimental long-term evaluation of a youth training program outside the US. We are able to track a representative sample of more than 3,200 youths at the six-year follow-up. Our e...

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

    International Nuclear Information System (INIS)

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

  20. Visual Imagery: Effects of Short- and Long-Term Memory

    OpenAIRE

    Ishai, A; Sagi, D.

    1997-01-01

    Visual imagery and perception share several functional properties and apparently share common underlying brain structures. A main approach to the scientific study of visual imagery is exploring the effects of mental imagery on perceptual processes. Previous studies have shown that visual imagery interferes with perception (Perky effect). Recently we have shown a direct facilitatory effect of visual imagery on visual perception. In an attempt to differentiate the conditions under which visual ...

  1. Long-term decline of radiocaesium in Fennoscandian reindeer

    Energy Technology Data Exchange (ETDEWEB)

    Skuterud, L. (Norwegian Radiation Protection Authority, Norwegian Reindeer Husbandry Administration (Norway)); AAhman, B. (Swedish Univ. of Agricultural Sciences (Sweden)); Solatie, D. (STUK-Radiation and Nuclear Safety Authority (Finland)); Gaare, E. (Norwegian Institute for Nature Researc (Norway))

    2009-06-15

    The NKS-B project REIN was established to synthesize the available information on contamination levels and effective half-times for 137Cs in reindeer in Finland, Sweden and Norway. Several studies of radiocaesium contamination in reindeer have been carried out in the Nordic countries over the last 50 years. However, the current slow decline in concentrations, which will maintain the consequences of the Chernobyl deposition for Swedish and Norwegian reindeer husbandry for at least another 10-20 years, have not previously been observed nor predicted. In the Chernobyl affected areas 137Cs concentrations in reindeer initially declined by effective half-times of 3-4 years, whereas the current decline appears to be mainly governed by the nuclide's physical half-life (30 years). The review of effective half-times of 137Cs in reindeer across Fennoscandia suggests that concentrations declined more rapidly in the northernmost areas. The reason(-s) remains unclear, and demonstrates the need for more long-term sampling of the various components of reindeer's diet. Such sampling should aim at covering climatically different areas, as climate may influence transfer of radiocaesium to reindeer via lichen growth and weathering rates, composition of plant communities and lichen availability, as well as soil-to-plant radiocaesium uptake. The lack of long-term data on radiocaesium in natural vegetation in the Nordic countries is one of the main limitations for the development of mechanistic models for radiocaesium in reindeer, and for further elucidation of the observed long-term trends in 137Cs concentrations in reindeer. Currently our understanding of the long-term trends observed in various areas is not good enough to predict how future radiocaesium deposition will behave. The high transfer of nuclides to reindeer, the geographical extension of reindeer herding and the special position of the Sami population in Finland, Sweden and Norway, demonstrates the need for maintaining competence and further developing the common basis for Nordic fallout management and emergency preparedness related to this food-chain. (au)

  2. Long-term decline of radiocaesium in Fennoscandian reindeer

    International Nuclear Information System (INIS)

    The NKS-B project REIN was established to synthesize the available information on contamination levels and effective half-times for 137Cs in reindeer in Finland, Sweden and Norway. Several studies of radiocaesium contamination in reindeer have been carried out in the Nordic countries over the last 50 years. However, the current slow decline in concentrations, which will maintain the consequences of the Chernobyl deposition for Swedish and Norwegian reindeer husbandry for at least another 10-20 years, have not previously been observed nor predicted. In the Chernobyl affected areas 137Cs concentrations in reindeer initially declined by effective half-times of 3-4 years, whereas the current decline appears to be mainly governed by the nuclide's physical half-life (30 years). The review of effective half-times of 137Cs in reindeer across Fennoscandia suggests that concentrations declined more rapidly in the northernmost areas. The reason(-s) remains unclear, and demonstrates the need for more long-term sampling of the various components of reindeer's diet. Such sampling should aim at covering climatically different areas, as climate may influence transfer of radiocaesium to reindeer via lichen growth and weathering rates, composition of plant communities and lichen availability, as well as soil-to-plant radiocaesium uptake. The lack of long-term data on radiocaesium in natural vegetation in the Nordic countries is one of the main limitations for the development of mechanistic models for radiocaesium in reindeer, and for further elucidation of the observed long-term trends in 137Cs concentrations in reindeer. Currently our understanding of the long-term trends observed in various areas is not good enough to predict how future radiocaesium deposition will behave. The high transfer of nuclides to reindeer, the geographical extension of reindeer herding and the special position of the Sami population in Finland, Sweden and Norway, demonstrates the need for maintaining competence and further developing the common basis for Nordic fallout management and emergency preparedness related to this food-chain. (au)

  3. Office of Disability, Aging and Long-Term Care Policy

    Science.gov (United States)

    ... 08/01/2015 Long-Term Care Awareness and Planning: What Do Americans Want? Adult Day Programs , Awareness , Disabled Persons , Evaluation Studies , Family , Goals , Health , Home Barrier Evaluation/Removal Services , Home Modification , Income , Insurance , Insurance, Long-Term Care , Long-Term Care , ...

  4. 17 CFR 256.224 - Other long-term debt.

    Science.gov (United States)

    2010-04-01

    ...2010-04-01 false Other long-term debt. 256.224 Section 256.224...AND SUBSIDIARY SERVICE COMPANIES, PUBLIC UTILITY HOLDING COMPANY ACT OF 1935 6. Long-Term Debt § 256.224 Other long-term debt. This account shall...

  5. Study on long-term behavior of weak rock

    Energy Technology Data Exchange (ETDEWEB)

    Okubo, Seisuke [Tokyo Univ., Tokyo (Japan)

    2003-03-01

    Using the boring core obtained in the Horonobe region, the beta in triaxial compression stress state was acquired, and the examination was carried out on the effect of the confirming pressure on long-term deformation or stability of the sample rock. At first, triaxial compression tests were carried out. In the test, loading rate (strain rate) was changed several times to obtain viscoelastic properties of the sample rock. Multi-stage creep tests were also performed in triaxial compression stress. The parameter set of a constitutive equation of variable compliance type was obtained based on the testing results. In this study, a transparent triaxial cell recently developed by this author was used. The external cylinder of this vessel was made of the transparent acrylic resin. Therefore, gradual deformation of the sample under testing was easily and clearly observed. (author)

  6. Biochemical effects on long-term frozen human costal cartilage

    International Nuclear Information System (INIS)

    Currently, the progresses on treatment of musculoskeletal diseases with the evolving of artificial implants and the success of tissue transplantation between genetically different individuals have conducted to an increase in radiosterilization. Regarding to tissue transplantation, it is essential to have sterile tissue and many tissue banks use radiosterilization as an effective method to sterilize these tissues. However, high doses of ionizing radiation and the preservation method may induce structural modifications in the tissues, as degradation of structural scaffold, decreasing its mechanical properties. Particularly, cartilage have been preserved in high concentrations of glycerol or deep-frozen at -70 degree C for storage after radiosterilization. Therefore, it is important to study the modifications induced in cartilage by preservation methods and by radiosterilization to determine the appropriated parameters for high quality of human allografts. Costal cartilages were obtained from cadaveric donors and were frozen at -20 degree C for 2 years long in order to compare with previous studies for fresh, deep-frozen and glycerolised cartilages. The mechanical tests were carried out in a universal testing machine until sample failure. According our results, there is no significant statistical difference between stress at break of fresh, long-term - 20 degree C frozen cartilages and deep-frozen cartilage. This early result suggests, regarding to tensile property, that long-term - 20 degree C frozen cartilages corresponds to glycerolised costal cartilages irradiated with 25 kGy or deep-frozen cartilages irradiated with 25 and 50 kGy. Thus, this long-term frozen cartilages may be used for tissue banks, but more studies about effects of ionizing radiation are necessary. (author)

  7. Biochemical effects on long-term frozen human costal cartilage

    Energy Technology Data Exchange (ETDEWEB)

    Santin, Stefany P.; Martinho Junior, Antonio C.; Yoshito, Daniele; Soares, Fernando A.N.; Mathor, Monica B., E-mail: mathor@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Currently, the progresses on treatment of musculoskeletal diseases with the evolving of artificial implants and the success of tissue transplantation between genetically different individuals have conducted to an increase in radiosterilization. Regarding to tissue transplantation, it is essential to have sterile tissue and many tissue banks use radiosterilization as an effective method to sterilize these tissues. However, high doses of ionizing radiation and the preservation method may induce structural modifications in the tissues, as degradation of structural scaffold, decreasing its mechanical properties. Particularly, cartilage have been preserved in high concentrations of glycerol or deep-frozen at -70 degree C for storage after radiosterilization. Therefore, it is important to study the modifications induced in cartilage by preservation methods and by radiosterilization to determine the appropriated parameters for high quality of human allografts. Costal cartilages were obtained from cadaveric donors and were frozen at -20 degree C for 2 years long in order to compare with previous studies for fresh, deep-frozen and glycerolised cartilages. The mechanical tests were carried out in a universal testing machine until sample failure. According our results, there is no significant statistical difference between stress at break of fresh, long-term - 20 degree C frozen cartilages and deep-frozen cartilage. This early result suggests, regarding to tensile property, that long-term - 20 degree C frozen cartilages corresponds to glycerolised costal cartilages irradiated with 25 kGy or deep-frozen cartilages irradiated with 25 and 50 kGy. Thus, this long-term frozen cartilages may be used for tissue banks, but more studies about effects of ionizing radiation are necessary. (author)

  8. Short- and Long-Term Cognitive Effects of Chronic Cannabinoids Administration in Late-Adolescence Rats

    OpenAIRE

    Abush, Hila; Akirav, Irit

    2012-01-01

    The use of cannabis can impair cognitive function, especially short-term memory. A controversial question is whether long-term cannabis use during the late-adolescence period can cause irreversible deficits in higher brain function that persist after drug use stops. In order to examine the short- and long-term effects of chronic exposure to cannabinoids, rats were administered chronic i.p. treatment with the CB1/CB2 receptor agonist WIN55,212-2 (WIN; 1.2 mg/kg) for two weeks during the late a...

  9. “Silent” Metaplasticity of the Late Phase of Long-Term Potentiation Requires Protein Phosphatases

    OpenAIRE

    Woo, Newton H.; Nguyen, Peter V

    2002-01-01

    The late phase of long-term potentiation (L-LTP) is correlated with some types of long-term memory, but the mechanisms by which L-LTP is modulated by prior synaptic activity are undefined. Activation of protein phosphatases by low-frequency stimulation (LFS) given before induction of L-LTP may significantly modify L-LTP. Using cellular electrophysiological recording methods in mouse hippocampal slices, we show that LFS given before induction of L-LTP inhibited L-LTP in an activity-dependent m...

  10. Soil seed bank of plant species as a function of long-term soil management and sampled depth Banco de sementes de espécies vegetais em função de distintos manejos do solo por longo período e profundidade amostrada

    OpenAIRE

    G. Concenço; J.C Salton; R.C Brevilieri; P.B Mendes; M.L Secretti

    2011-01-01

    This study aimed at assessing the level of weed infestation indifferent areas that were submitted to different soil management for 16 years. Four management systems were studied: (1) agriculture only under conventional tillage system; (2) agriculture only under no-till system; (3) crop-livestock integrationcrop-livestock integration; (4) livestock only. These areas were sampled at three soil depths (0-5, 5-10 and 10-15 cm), and soil was stored in plastic pots and taken to a greenhouse, where ...

  11. The effects of long-term captivity on the metabolic parameters of a small Afrotropical bird.

    Science.gov (United States)

    Thompson, Lindy J; Brown, Mark; Downs, Colleen T

    2015-04-01

    The few within-species studies on the effects of long-term captivity on avian physiological variables have small samples sizes and contradictory results. Nevertheless, many physiological studies make use of long-term captive birds, assuming the results will be applicable to wild populations. Here we investigated the effects of long-term captivity on a variety of physiological measurements in a relatively small (~12 g) southern African endemic bird, the Cape white-eye (Zosterops virens). Whole animal basal metabolic rate (BMR) and body mass (Mb) were influenced more by long-term captivity than by season, while mass-specific BMR, standard and basal whole animal and mass-specific evaporative water loss (EWL), and respiratory quotient (RQ), were all affected primarily by season, with long-term captivity having less of an effect. We therefore caution that whole animal BMR and Mb of long-term captive birds should not be used as representative of wild populations, and that the origin of study birds should be considered when comparing EWL and RQ of wild and long-term captive birds. PMID:25636901

  12. Long-term predictions using natural analogues

    International Nuclear Information System (INIS)

    One of the unique and scientifically most challenging aspects of nuclear waste isolation is the extrapolation of short-term laboratory data (hours to years) to the long time periods (103-105 years) required by regulatory agencies for performance assessment. The direct validation of these extrapolations is not possible, but methods must be developed to demonstrate compliance with government regulations and to satisfy the lay public that there is a demonstrable and reasonable basis for accepting the long-term extrapolations. Natural systems (e.g., open-quotes natural analoguesclose quotes) provide perhaps the only means of partial open-quotes validation,close quotes as well as data that may be used directly in the models that are used in the extrapolation. Natural systems provide data on very large spatial (nm to km) and temporal (103-108 years) scales and in highly complex terranes in which unknown synergisms may affect radionuclide migration. This paper reviews the application (and most importantly, the limitations) of data from natural analogue systems to the open-quotes validationclose quotes of performance assessments

  13. Workload measurement in long term care pharmacy.

    Science.gov (United States)

    Ruth, S; Eagleson, D; Ilersich, A L

    1990-06-01

    This paper describes the implementation of the Canadian Hospital Pharmacy Workload Measurement System (CHPWMS) by the pharmacy department of a 475-bed long term care facility. The CHPWMS description of a computerized individual patient prescription service provided the basis for the implementation. Following an initial appraisal of similarities between chronic care pharmacy services and the services outlined by CHPWMS, a program was developed and evaluated with the assistance of a pharmacist consultant. During a four-month trial all measurable work was recorded in a process that separated reportable (CHPWMS-defined) activities from other work activities. Eighty percent of the department's workload was accountable as reportable units using standard times. Nonreportable workload was documented using actual times, and adapted standard times. Dispensing accounted for the largest proportion of workload (79%). Manufacturing was the most frequently performed nonreportable activity. Pharmacist workload supported the desired level of 50% nondispensing activities. The productivity index of available worked hours was 70%. The consistent pattern of the recording suggested staff commitment. The program has been used to justify and monitor staffing levels. PMID:10105648

  14. Long-term plutonium storage: Design concepts

    International Nuclear Information System (INIS)

    An important part of the Department of Energy (DOE) Weapons Complex Reconfiguration (WCR) Program is the development of facilities for long-term storage of plutonium. The WCR design goals are to provide storage for metals, oxides, pits, and fuel-grade plutonium, including material being held as part of the Strategic Reserve and excess material. Major activities associated with plutonium storage are sorting the plutonium inventory, material handling and storage support, shipping and receiving, and surveillance of material in storage for both safety evaluations and safeguards and security. A variety of methods for plutonium storage have been used, both within the DOE weapons complex and by external organizations. This paper discusses the advantages and disadvantages of proposed storage concepts based upon functional criteria. The concepts discussed include floor wells, vertical and horizontal sleeves, warehouse storage on vertical racks, and modular storage units. Issues/factors considered in determining a preferred design include operational efficiency, maintenance and repair, environmental impact, radiation and criticality safety, safeguards and security, heat removal, waste minimization, international inspection requirements, and construction and operational costs

  15. Long-term acute care hospitals.

    Science.gov (United States)

    Munoz-Price, L Silvia

    2009-08-01

    Long-term acute care hospitals (LTACHs) are health care facilities that admit complex patients with acute care needs (eg, mechanical ventilator weaning, administration of intravenous antibiotics, and complex wound care) for a mean duration of stay of 25 days. LTACHs are different than nursing homes and were initially created in the 1990s in an effort to decrease Medicare costs by facilitating prompt discharge from intensive care units of patients with difficulty weaning mechanical ventilation; however, current admission diagnoses are quite broad. Patients admitted to these facilities have multiple comorbidities and are at risk for colonization with multidrug-resistant organisms. LTACH patients have been shown to have high rates of hospital-acquired infections, including central vascular catheter-associated bloodstream infection and ventilator-associated pneumonia. In addition, LTACHs have been implicated in various regional outbreaks of multidrug-resistant organisms. This review summarizes the limited amount of scientific literature on LTACHs while highlighting their infection control problems, as well as the role LTACHs play on regional outbreaks. PMID:19548836

  16. Long Term Evolution of Plasma Wakefields

    CERN Document Server

    Sahai, Aakash A; Tsung, F S; Mori, W B

    2014-01-01

    We study the long-term evolution (LTE) of plasma wakefields over multiple plasma-electron periods and few plasma-ion periods, much less than a recombination time. The evolution and relaxation of such a wakefield-perturbed plasma over these timescales has important implications for the upper limits of repetition-rates in plasma colliders. Intense fields in relativistic lasers (or intense beams) create plasma wakefields (modes around {\\omega}pe) by transferring energy to the plasma electrons. Charged-particle beams in the right phase may be accelerated with acceleration/focusing gradients of tens of GeV/m. However, wakefields leave behind a plasma not in equilibrium, with a relaxation time of multiple plasma-electron periods. Ion motion over ion timescales, caused by energy transfer from the driven plasma-electrons to the plasma-ions can create interesting plasma states. Eventually during LTE, the dynamics of plasma de-coheres (multiple modes through instability driven mixing), thermalizing into random motion (...

  17. [Long-term prognosis of ulcerative colitis].

    Science.gov (United States)

    Kaminaga, N; Satake, Y

    1999-11-01

    Despite its intermittent course of activity and remission, the good response to salazopyridine and steroids makes the long-term prognosis of ulcerative colitis favorable. The number of non-active type ulcerative colitis is increasing and consequently, the rate of active disease and relapse is decreasing every year. More than 90% of the patients even with disease of 10 or more years are able to work almost with no limits for the daily living. The colectomy rate in Japan is 4.1% after one year of the onset of the disease and 6.8% after 2 years. Thereafter approximately 1% of the patients undergo surgery yearly. The most common reasons of surgery are complications such as massive bleeding, perforation or toxic megacolon. Other indications are chronic continuous disease and cases with frequent relapses. Considering the extension of the disease, about one-third of the total colitis type and 10% of the left-sided type undergo surgery. The risk of colonic cancer is higher in patients with total colitis type and when has had the disease for more than 10 years. Most of the them are flat type poor-differentiated adenocarcinomas. Therefore patients with total colitis type for more than 10 years should undergo colonoscopic surveillance. PMID:10572407

  18. Long-term outcome of neuroparacoccidioidomycosis treatment

    Directory of Open Access Journals (Sweden)

    Fabio Francesconi

    2011-02-01

    Full Text Available INTRODUCTION: Neuroparacoccidioidomycosis (NPCM is a term used to describe the invasion of the central nervous system by the pathogenic fungus Paracoccidioides brasiliensis. NPCM has been described sporadically in some case reports and small case series, with little or no focus on treatment outcome and long-term follow-up. METHODS: All patients with NPCM from January 1991 to December 2006 were analyzed and were followed until December 2009. RESULTS: Fourteen (3.8% cases of NPCM were identified out of 367 patients with paracoccidioidomycosis (PCM. A combination of oral fluconazole and sulfamethoxazole/trimethoprim (SMZ/TMP was the regimen of choice, with no documented death due to Paracoccidioides brasiliensis infection. Residual neurological deficits were observed in 8 patients. Residual calcification was a common finding in neuroimaging follow-up. CONCLUSIONS: All the patients in this study responded positively to the association of oral fluconazole and sulfamethoxazole/trimethoprim, a regimen that should be considered a treatment option in cases of NPCM. Neurological sequela was a relatively common finding. For proper management of these patients, anticonvulsant treatment and physical therapy support were also needed.

  19. Long-term results of pancreatic cancer

    International Nuclear Information System (INIS)

    Long-term results of radiotherapy of 131 pancreatic cancer patients were discussed. The mean survival time after the therapy was 15.6 mos., in patients with histology verified diagnosis of cancer - 15 mos. During 1 year 64.4% of the patients survived, 2 years - 44.7%, 3 years - 35.2%, 4 years - 9.6%, 5 years - 3.2%. The results obtained were 2.5-fold better than those after biliodigestive anastomoses and 3-fold better than those after chemotherapy. Irradiation within a short period (0.5-1 month) after palliative or exploratory operation (the mean survival time was 20.9 mos.) seemed one of the most realistic methods for improving therapeutic results in pancreatic cancer. The mean survival after placing cholecystojejunoanastamosis and radiotherapy was 17.7 mos. (from the onset of irradiation), after exploratory laparatomy and irradiation - 18.9 mos., after palliative tumor resecton and irradiation - 23.9 mos. The efficacy of radiotherapy was lowered with increasing an interval between explorative or palliative operation and irradiation. A split course of ?-beam therapy was recommended depending on a patient's general status (10-20 after Karnovsky)

  20. Long-term predictions using natural analogues

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, R.C. [Univ. of New Mexico, Albuquerque, NM (United States)

    1995-09-01

    One of the unique and scientifically most challenging aspects of nuclear waste isolation is the extrapolation of short-term laboratory data (hours to years) to the long time periods (10{sup 3}-10{sup 5} years) required by regulatory agencies for performance assessment. The direct validation of these extrapolations is not possible, but methods must be developed to demonstrate compliance with government regulations and to satisfy the lay public that there is a demonstrable and reasonable basis for accepting the long-term extrapolations. Natural systems (e.g., {open_quotes}natural analogues{close_quotes}) provide perhaps the only means of partial {open_quotes}validation,{close_quotes} as well as data that may be used directly in the models that are used in the extrapolation. Natural systems provide data on very large spatial (nm to km) and temporal (10{sup 3}-10{sup 8} years) scales and in highly complex terranes in which unknown synergisms may affect radionuclide migration. This paper reviews the application (and most importantly, the limitations) of data from natural analogue systems to the {open_quotes}validation{close_quotes} of performance assessments.