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1

Climate Predictability and Long Term Memory  

Science.gov (United States)

The benefit of climate Long Term Memory (LTM) for long term prediction is assessed using data from a millennium control simulation with the atmosphere ocean general circulation model ECHAM5/MPIOM. The forecast skills are evaluated for surface temperature time series at individual grid points. LTM is characterised by the Hurst exponent in the power-law scaling of the fluctuation function which is determined by detrended fluctuation analysis (DFA). LTM with a Hurst exponent close to 0.9 occurs mainly in high latitude oceans, which are also characterized by high potential predictability. Climate predictability is diagnosed in terms of potentially predictable variance fractions. Explicit prediction experiments for various time steps are conducted on a grid point basis using an auto-correlation (AR1) predictor: in regions with LTM, prediction skills are beyond that expected from red noise persistence; exceptions occur in some areas in the southern oceans and over the northern hemisphere continents. Extending the predictability analysis to the fully forced simulation shows large improvement in prediction skills.

Zhu, X.; Blender, R.; Fraedrich, K.; Liu, Z.

2010-09-01

2

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

UK PubMed Central (United Kingdom)

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

Bell MC; Kawadri N; Simone PM; Wiseheart M

2013-03-01

3

Two different biological configurations for long-term memory.  

UK PubMed Central (United Kingdom)

Long-term memory (LTM) in Hermissenda can be distinguished from consolidated long-term memory (CLTM) by determining how long recall is retained. LTM is retained for approximately 1 day, while CLTM is retained for at least 3 days. During the transition from LTM to CLTM, the extent of retention appears to depend partially on how much consolidation has been completed. Several models are discussed that may be related to the two different manifestations of recall.

Epstein HT; Kuzirian AM; Child FM; Alkon DL

2004-01-01

4

Practicing memory retrieval improves long-term retention in rats.  

UK PubMed Central (United Kingdom)

The view that the human mind is a repository of stored items dates at least to Aristotle and Plato and continues to dominate investigations of human memory [1]. This view fits with our intuitions that we study information as the optimal method to store information in memory and that retrieval of information functions only to assess what information was previously stored. Yet modern research on human memory suggests that retrieving information during a test facilitates later memory of that information [2-6]. Because human memory is intertwined with language, it is difficult to resist the conclusion that language is essential for this key aspect of human cognition. Here we show that practising memory retrieval improves long-term retention in a nonhuman species. We report evidence that rats' long-term memory performance is enhanced if they had previously retrieved specific items stored in memory.

Crystal JD; Ketzenberger JA; Alford WT

2013-09-01

5

Evidence for long-term spatial memory in a parid.  

UK PubMed Central (United Kingdom)

Many animals use spatial memory. Although much work has examined the accuracy of spatial memory, few studies have explicitly focused on its longevity. The importance of long-term spatial memory for foraging has been demonstrated in several cases. However, the importance of such long-term memory for all animals is unclear. In this study, we present the first evidence that a parid species (the black-capped chickadee, Poecile atricapillus) can remember the location of a single food item for at least 6 months under an associative-learning spatial memory paradigm with multiple reinforcements. We did not detect a significant difference in memory longevity between two populations of chickadees shown previously to differ in short-term spatial memory and hippocampal morphology, an area of the brain involved in spatial memory. Our study showed that small birds such as parids can maintain spatial memories for long periods, a feat shown previously only in corvids. Moreover, we were able to demonstrate this longevity within the context of only 16 repeated trials. We speculate that this ability may potentially be useful in relocating caches if reinforced by repeated visits. Future studies are necessary to test whether our results were specifically due to multiple reinforcements of the food-containing location and whether parids may have similar memory longevity during food-caching experiences in the wild.

Roth TC; LaDage LD; Pravosudov VV

2012-03-01

6

A Biochemical Blueprint for Long-Term Memory  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The greatest barrier to the long-term storage of information in a biological system is the inevitability of molecular turnover. In this review, we discuss the features required of any chemical mechanism capable of overcoming this obstacle, positing that a specific type of “mnemogenic”, or memory-for...

Roberson, Erik D.; Sweatt, J. David

7

Long Term Potentiation as a Mechanism for Learning and Memory  

Directory of Open Access Journals (Sweden)

Full Text Available Since the 1970s when long term potentiation (LTP) was introduced to the scientific world;several studies have been devoted to determining whether this phenomenon is naturally abasic mechanism of learning and memory in mammalian brains. However, plenty of evidenceconfirms that a) LTP is inducible in the circuits involved in learning and memory; b) commonreceptors and intracellular cascades are recruited in both memory and synaptic plasticityand c) LTP and memory are similarly affected by many parameters such as: ligands, environmentalsignals, history of neuronal activity. Despite this, contradictory reports exist whichoppose the similarities between LTP and memory. In this paper we briefly introduce learning,memory and LTP, and argue relevant factors that possibly connect them. Ultimately, currentconsiderations lead one to conclude that the time is too early to judge clearly if LTP is a realmechanism of learning and memory.

Sayyed Alireza Talaei Zavareh; Gholamali Hamidi; Mahmoud Salami

2009-01-01

8

Binding actions and scenes in visual long-term memory.  

Science.gov (United States)

How does visual long-term memory store representations of different entities (e.g., objects, actions, and scenes) that are present in the same visual event? Are the different entities stored as an integrated representation in memory, or are they stored separately? To address this question, we asked observers to view a large number of events; in each event, an action was performed within a scene. Afterward, the participants were shown pairs of action-scene sets and indicated which of the two they had seen. When the task required recognizing the individual actions and scenes, performance was high (80 %). Conversely, when the task required remembering which actions had occurred within which scenes, performance was significantly lower (59 %). We observed this dissociation between memory for individual entities and memory for entity bindings across multiple testing conditions and presentation durations. These experiments indicate that visual long-term memory stores information about actions and information about scenes separately from one another, even when an action and scene were observed together in the same visual event. These findings also highlight an important limitation of human memory: Situations that require remembering actions and scenes as integrated events (e.g., eyewitness testimony) may be particularly vulnerable to memory errors. PMID:23653419

Urgolites, Zhisen Jiang; Wood, Justin N

2013-05-01

9

Binding actions and scenes in visual long-term memory.  

UK PubMed Central (United Kingdom)

How does visual long-term memory store representations of different entities (e.g., objects, actions, and scenes) that are present in the same visual event? Are the different entities stored as an integrated representation in memory, or are they stored separately? To address this question, we asked observers to view a large number of events; in each event, an action was performed within a scene. Afterward, the participants were shown pairs of action-scene sets and indicated which of the two they had seen. When the task required recognizing the individual actions and scenes, performance was high (80 %). Conversely, when the task required remembering which actions had occurred within which scenes, performance was significantly lower (59 %). We observed this dissociation between memory for individual entities and memory for entity bindings across multiple testing conditions and presentation durations. These experiments indicate that visual long-term memory stores information about actions and information about scenes separately from one another, even when an action and scene were observed together in the same visual event. These findings also highlight an important limitation of human memory: Situations that require remembering actions and scenes as integrated events (e.g., eyewitness testimony) may be particularly vulnerable to memory errors.

Urgolites ZJ; Wood JN

2013-05-01

10

Effects of perceived long-term stress on subjective and objective aspects of memory and cognitive functioning in a middle-aged population-based sample.  

UK PubMed Central (United Kingdom)

The longitudinal effects of perceived stress on measures of memory and two other cognitive functions (word fluency, visuospatial ability) in a middle-aged sample (40-60 years, M age = 47.1 years, SD = 6.1 years; n = 192) were examined. A group describing themselves as stressed in general at baseline, and at follow-up measurement 5 and 10 years later (n = 96) was compared with a matched (age, sex) low-stress group (n = 96). The results revealed more depressive symptoms over time in the high-stress group. With regard to memory, a dissociation between subjective and objective measures was observed. Specifically, participants in the high-stress group rated their memory as worse over time as compared with controls, and reported a higher frequency of occurrence of everyday memory failures, effects partly independent of depressive symptoms. However, the groups did not differ in terms of objective episodic memory performance, word fluency or block design performance, with stable levels of performance over time regardless of perceived stress. The lack of effects of stress on cognitive performance is discussed in the light of factors such as stress level, age of the participants, and other individual difference factors.

Rönnlund M; Sundström A; Sörman DE; Nilsson LG

2013-01-01

11

Visual long-term memory has the same limit on fidelity as visual working memory.  

UK PubMed Central (United Kingdom)

Visual long-term memory can store thousands of objects with surprising visual detail, but just how detailed are these representations, and how can one quantify this fidelity? Using the property of color as a case study, we estimated the precision of visual information in long-term memory, and compared this with the precision of the same information in working memory. Observers were shown real-world objects in random colors and were asked to recall the colors after a delay. We quantified two parameters of performance: the variability of internal representations of color (fidelity) and the probability of forgetting an object's color altogether. Surprisingly, the fidelity of color information in long-term memory was comparable to the asymptotic precision of working memory. These results suggest that long-term memory and working memory may be constrained by a common limit, such as a bound on the fidelity required to retrieve a memory representation.

Brady TF; Konkle T; Gill J; Oliva A; Alvarez GA

2013-06-01

12

Long-Term Ecological Monitoring Field Sampling Plan for 2007  

Energy Technology Data Exchange (ETDEWEB)

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

T. Haney

2007-07-31

13

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.

2007-01-01

14

Hippocampal focal knockout of CBP affects specific histone modifications, long-term potentiation, and long-term memory.  

UK PubMed Central (United Kingdom)

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

Barrett RM; Malvaez M; Kramar E; Matheos DP; Arrizon A; Cabrera SM; Lynch G; Greene RW; Wood MA

2011-07-01

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Erythropoietin enhances hippocampal long-term potentiation and memory  

Directory of Open Access Journals (Sweden)

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

Adamcio Bartosz; Sargin Derya; Stradomska Alicja; Medrihan Lucian; Gertler Christoph; Theis Fabian; Zhang Mingyue; Müller Michael; Hassouna Imam; Hannke Kathrin; Sperling Swetlana; Radyushkin Konstantin; El-Kordi Ahmed; Schulze Lizzy; Ronnenberg Anja; Wolf Fred; Brose Nils; Rhee Jeong-Seop; Zhang Weiqi; Ehrenreich Hannelore

2008-01-01

16

Long-term memory and volatility clustering in high-frequency price changes  

Science.gov (United States)

We studied the long-term memory in diverse stock market indices and foreign exchange rates using Detrended Fluctuation Analysis (DFA). For all high-frequency market data studied, no significant long-term memory property was detected in the return series, while a strong long-term memory property was found in the volatility time series. The possible causes of the long-term memory property were investigated using the return data filtered by the AR(1) model, reflecting the short-term memory property, the GARCH(1,1) model, reflecting the volatility clustering property, and the FIGARCH model, reflecting the long-term memory property of the volatility time series. The memory effect in the AR(1) filtered return and volatility time series remained unchanged, while the long-term memory property diminished significantly in the volatility series of the GARCH(1,1) filtered data. Notably, there is no long-term memory property, when we eliminate the long-term memory property of volatility by the FIGARCH model. For all data used, although the Hurst exponents of the volatility time series changed considerably over time, those of the time series with the volatility clustering effect removed diminish significantly. Our results imply that the long-term memory property of the volatility time series can be attributed to the volatility clustering observed in the financial time series.

Oh, Gabjin; Kim, Seunghwan; Eom, Cheoljun

2008-02-01

17

Long-term consequences of subarachnoid hemorrhage: Examining working memory.  

Science.gov (United States)

Working memory impairments are prevalent among survivors of aneurysmal subarachnoid hemorrhage (SAH), but few studies have examined specifically these impairments. Such an examination is important because working memory processes are vital for daily cognitive functioning. In the current study, patients with SAH and healthy control participants were administered the word-span and alpha-span test - experimental tests of working memory. In the word-span test, participants recalled increasingly longer word-lists, requiring the maintenance of information in mind. In the alpha-span test, participants recalled the word-lists in alphabetical order, requiring both the maintenance and manipulation of information. Patients with SAH were no different from healthy controls on a battery of standard neuropsychological measures or on the word-span test. They were, however, significantly impaired on the alpha-span test, suggesting a deficit in the manipulation components of working memory. That is, impairment resulting from SAH is present when a working memory task requires additional executive processing demands. This deficit in patients with SAH does not appear to be influenced by aneurysm location, suggesting that some of the effects of SAH on cognition are from diffuse rather than focal pathology; however, a larger sample size is needed to reinforce this claim. PMID:23871092

Sheldon, Signy; Macdonald, R Loch; Cusimano, Michael; Spears, Julian; Schweizer, Tom A

2013-07-18

18

Long-term consequences of subarachnoid hemorrhage: Examining working memory.  

UK PubMed Central (United Kingdom)

Working memory impairments are prevalent among survivors of aneurysmal subarachnoid hemorrhage (SAH), but few studies have examined specifically these impairments. Such an examination is important because working memory processes are vital for daily cognitive functioning. In the current study, patients with SAH and healthy control participants were administered the word-span and alpha-span test - experimental tests of working memory. In the word-span test, participants recalled increasingly longer word-lists, requiring the maintenance of information in mind. In the alpha-span test, participants recalled the word-lists in alphabetical order, requiring both the maintenance and manipulation of information. Patients with SAH were no different from healthy controls on a battery of standard neuropsychological measures or on the word-span test. They were, however, significantly impaired on the alpha-span test, suggesting a deficit in the manipulation components of working memory. That is, impairment resulting from SAH is present when a working memory task requires additional executive processing demands. This deficit in patients with SAH does not appear to be influenced by aneurysm location, suggesting that some of the effects of SAH on cognition are from diffuse rather than focal pathology; however, a larger sample size is needed to reinforce this claim.

Sheldon S; Macdonald RL; Cusimano M; Spears J; Schweizer TA

2013-09-01

19

Wnt transmembrane signaling and long-term spatial memory.  

UK PubMed Central (United Kingdom)

Transmembrane signaling mechanisms are critical for regulating the plasticity of neuronal connections underlying the establishment of long-lasting memory (e.g., Linden and Routtenberg (1989) Brain Res Rev 14:279-296; Sossin (1996) Trends Neurosci 19:215-218; Mayr and Montminy (2001) Nat Rev Mol Cell Biol 2:599-609; Chen et al. (2011) Nature 469:491-497). One signaling mechanism that has received surprisingly little attention in this regard is the well-known Wnt transmembrane signaling pathway even though this pathway in the adult plays a significant role, for example, in postsynaptic dendritic spine morphogenesis and presynaptic terminal neurotransmitter release (Inestrosa and Arenas (2010) Nat Rev Neurosci 11:77-86). The present report now provides the first evidence of Wnt signaling in spatial information storage processes. Importantly, this Wnt participation is specific and selective. Thus, spatial, but not cued, learning in a water maze selectively elevates the levels in hippocampus of Wnt 7 and Wnt 5a, but not the Wnt 3 isoform, indicating behavioral selectivity and isoform specificity. Wnt 7 elevation is subfield-specific: granule cells show an increase with no detectable change in CA3 neurons. Wnt 7 elevation is temporally specific: increased Wnt signaling is not observed during training, but is seen 7 days and, unexpectedly, 30 days later. If the Wnt elevation after learning is activity-dependent, then it may be possible to model this effect in primary hippocampal neurons in culture. Here, we evaluate the consequence of potassium or glutamate depolarization on Wnt signaling. This represents, to our knowledge, the first demonstration of an activation-dependent elevation of Wnt levels and surprisingly an increased number of Wnt-stained puncta in neurites suggestive of trafficking from the cell body to neuronal processes, probably dendrites. It is proposed that Wnt signaling pathways regulate long-term information storage in a behavioral-, cellular-, and isoform-specific manner.

Tabatadze N; Tomas C; McGonigal R; Lin B; Schook A; Routtenberg A

2012-06-01

20

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

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this study was to compare the Short Term Memory and Long Term Memory of Athlete and non Athlete. One hundred college boys (50 Athlete participated in inter-college tournament and 50 non Athlete) from different colleges of north 24 district in West Bengal were considered for this study whose age range between 22 to 25 years. Only, Short Term and Long Term memory were measured for this study. Standard questionnaires were used for this study. The statistical 't' test was applied to investigate the existence of significant difference in Short Term Memory and Long Term Memory between Athlete and non Athlete. In conclusion Athlete performed better in the both tests i.e. Short Term Memory and Long Term Memory in comparison to non Athlete and the difference was statistically significant. Exercise not only gives healthy life style but also improve memory function. so regular exercise is strongly recommended.

GOPAL CHANDRA SAHA; SHANTANU HALDER; PULEN DAS

2013-01-01

 
 
 
 
21

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

Directory of Open Access Journals (Sweden)

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

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

2000-01-01

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

Science.gov (United States)

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

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

2011-01-01

23

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

Science.gov (United States)

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

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

2007-01-01

24

Long-term variability of a complete sample of quasars  

Energy Technology Data Exchange (ETDEWEB)

The long-term variability of a complete sample of quasars selected in the field of the SA 94 has been investigated. Using Schmidt plates covering a time baseline of seven years, about one-third of the quasars are found to be variable. It is suggested that all the quasi-stellar objects are variable with amplitudes of a few tenths of a magnitude on timescales of the order of some years in their restframes. The application of the variability technique to the selection of complete samples of quasars is discussed. The timescales estimated can be easily accounted for in the accreting black hole with thermal and viscous timescales. The variability is found to be correlated with the absolute magnitude and/or the redshift. 21 refs.

Cristiani, S.; Vio, R.; Andreani, P. (Padova Universita, Padua (Italy))

1990-07-01

25

Working memory capacity and retrieval from long-term memory: the role of controlled search.  

UK PubMed Central (United Kingdom)

In two experiments, the role of working memory capacity (WMC) in the controlled search of long-term memory was examined. Participants performed a prolonged category fluency task that required them to retrieve as many animals as possible in 5 min. The results suggested that WMC differences arose in the numbers of animals retrieved, the numbers of clusters retrieved, and the rates of the retrieval (Exp. 1). However, no differences were found in terms of how participants initiated retrieval or in the nature of the clusters generated. Furthermore, an examination of differences in retrieval strategies suggested that high-WMC individuals were more strategic than low-WMC individuals and that these differences in retrieval strategies accounted for the overall differences in the numbers of animals retrieved. Additionally, presenting participants with retrieval cues eliminated WMC differences in the numbers of animals retrieved (Exp. 2). These results suggest that low-WMC individuals are less able than high-WMC individuals to select and utilize appropriate retrieval strategies to self-generate cues to access information in long-term memory. Collectively, the results are consistent with research suggesting that WMC is important for controlled search from long-term memory.

Unsworth N; Brewer GA; Spillers GJ

2013-02-01

26

Musical and verbal memory in Alzheimer's disease: a study of long-term and short-term memory.  

UK PubMed Central (United Kingdom)

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 memory using a task that used pseudowords (LTM) or syllables (STM). Results indicated impaired musical memory in AD patients relative to healthy controls. The deficit was found for both long-term and short-term memory. Furthermore, it was of the same magnitude for both musical and verbal domains whether tested with short-term or long-term memory tasks. No correlation was found between musical and verbal LTM. However, there was a significant correlation between verbal and musical STM in AD participants and healthy older adults, which suggests that the two domains may share common mechanisms.

Ménard MC; Belleville S

2009-10-01

27

Short-term memory to long-term memory transition in a nanoscale memristor.  

Science.gov (United States)

"Memory" is an essential building block in learning and decision-making in biological systems. Unlike modern semiconductor memory devices, needless to say, human memory is by no means eternal. Yet, forgetfulness is not always a disadvantage since it releases memory storage for more important or more frequently accessed pieces of information and is thought to be necessary for individuals to adapt to new environments. Eventually, only memories that are of significance are transformed from short-term memory into long-term memory through repeated stimulation. In this study, we show experimentally that the retention loss in a nanoscale memristor device bears striking resemblance to memory loss in biological systems. By stimulating the memristor with repeated voltage pulses, we observe an effect analogous to memory transition in biological systems with much improved retention time accompanied by additional structural changes in the memristor. We verify that not only the shape or the total number of stimuli is influential, but also the time interval between stimulation pulses (i.e., the stimulation rate) plays a crucial role in determining the effectiveness of the transition. The memory enhancement and transition of the memristor device was explained from the microscopic picture of impurity redistribution and can be qualitatively described by the same equations governing biological memories. PMID:21861506

Chang, Ting; Jo, Sung-Hyun; Lu, Wei

2011-08-26

28

Short-term memory to long-term memory transition in a nanoscale memristor.  

UK PubMed Central (United Kingdom)

"Memory" is an essential building block in learning and decision-making in biological systems. Unlike modern semiconductor memory devices, needless to say, human memory is by no means eternal. Yet, forgetfulness is not always a disadvantage since it releases memory storage for more important or more frequently accessed pieces of information and is thought to be necessary for individuals to adapt to new environments. Eventually, only memories that are of significance are transformed from short-term memory into long-term memory through repeated stimulation. In this study, we show experimentally that the retention loss in a nanoscale memristor device bears striking resemblance to memory loss in biological systems. By stimulating the memristor with repeated voltage pulses, we observe an effect analogous to memory transition in biological systems with much improved retention time accompanied by additional structural changes in the memristor. We verify that not only the shape or the total number of stimuli is influential, but also the time interval between stimulation pulses (i.e., the stimulation rate) plays a crucial role in determining the effectiveness of the transition. The memory enhancement and transition of the memristor device was explained from the microscopic picture of impurity redistribution and can be qualitatively described by the same equations governing biological memories.

Chang T; Jo SH; Lu W

2011-09-01

29

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

Science.gov (United States)

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

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

2005-01-01

30

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

Czech Academy of Sciences Publication Activity Database

approximate entropyKód oboru RIV: AH - Ekonomie http://library.utia.cas.cz/separaty/2013/E/kristoufek-measuring capital market efficienci long-term memory fractal dimension and approximate entropy.pdf

Krištoufek, LadislavG; Vošvrda, Miloslav

31

Long-term working memory deficits after concussion: Electrophysiological evidence.  

UK PubMed Central (United Kingdom)

Abstract Background: Persistent complaints of lingering memory and concentration difficulties are common following a concussion, although the brain basis of these is unknown. Some suggest abnormalities can be found on the P300 event-related potential component, recorded using electroencephalography (EEG), despite unobservable cognitive impairments. Objective: To examine the P300 and cognitive performance following a remote concussion during an n-back task that varies in working memory load. Research design: Seventeen participants with a remote concussion and 17 controls performed a visual n-back task in which working memory demands were systematically increased by manipulating cognitive load. Participants also completed neuropsychological and self-report measures. Results: The concussion group showed a decrease in P300 amplitude compared to controls that was independent of working memory load on the n-back task. While no performance differences were observed between groups, P300 amplitude was negatively correlated with response times at higher loads in both groups. Conclusion: High functioning young adults with a remote concussion may have inefficient recruitment of processing resources for target identification, evident by the attenuated P300. The negative correlations between response time and P300 amplitude suggest that the time necessary to accurately respond to targets increases as the efficiency of allocating processing resources decreases during highly demanding working memory tasks.

Ozen LJ; Itier RJ; Preston FF; Fernandes MA

2013-01-01

32

How do observer's responses affect visual long-term memory?  

UK PubMed Central (United Kingdom)

How does responding to an object affect explicit memory for visual information? The close theoretical relationship between action and perception suggests that items that require a response should be better remembered than items that require no response. However, conclusive evidence for this claim is lacking, as semantic coherence, category size, and trial frequency often differ between stimuli that require a response and those that do not. Here we showed that memory is affected by response requirements, even when confounding factors were eliminated. Participants viewed a stream of images and encoded them into memory. During encoding, some images required a response, whereas others did not. Although all images were task relevant, images that were overtly responded to (e.g., with a button press) were better remembered than those that were not. However, the action itself was not critical to the memory advantage. Covertly counted images were better remembered than those that were not. Moreover, when participants pressed a button for most images, images that required withholding a button press were remembered better than the others. We conclude that the need to modify an ongoing activity results in improved memory.

Makovski T; Jiang YV; Swallow KM

2013-07-01

33

Controlling conflict from interfering long-term memory representations.  

UK PubMed Central (United Kingdom)

Remembering is more than an activation of a memory trace. As retrieval cues are often not uniquely related to one specific memory, cognitive control should come into play to guide selective memory retrieval by focusing on relevant while ignoring irrelevant information. Here, we investigated, by means of EEG and fMRI, how the memory system deals with retrieval interference arising when retrieval cues are associated with two material types (faces and spatial positions), but only one is task-relevant. The topography of slow EEG potentials and the fMRI BOLD signal in posterior storage areas indicated that in such situations not only the relevant but also the irrelevant material becomes activated. This results in retrieval interference that triggers control processes mediated by the medial and lateral PFC, which are presumably involved in biasing target representations by boosting the task-relevant material. Moreover, memory-based conflict was found to be dissociable from response conflict that arises when the relevant and irrelevant materials imply different responses. The two types of conflict show different activations in the medial frontal cortex, supporting the claim of domain-specific prefrontal control systems.

Jost K; Khader PH; Düsel P; Richter FR; Rohde KB; Bien S; Rösler F

2012-05-01

34

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

UK PubMed Central (United Kingdom)

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 goal of this study was to examine the effect of manipulating a task-independent stressor (elevated light level) on short-term and long-term memory in the novel object recognition paradigm. Short-term memory was elicited in both low light and high light conditions, but long-term memory specifically required high light conditions during the acquisition phase (familiarization trial) and was independent of the light level during retrieval (test trial). Additionally, long-term memory appeared to be independent of stress-mediated glucocorticoid release, as both low and high light produced similar levels of plasma corticosterone, which further did not correlate with subsequent memory performance. Finally, both short-term and long-term memory showed no savings between repeated experiments suggesting that this novel object recognition paradigm may be useful for longitudinal studies, particularly when investigating treatments to stabilize or enhance weak memories in neurodegenerative diseases or during age-related cognitive decline.

Moore SJ; Deshpande K; Stinnett GS; Seasholtz AF; Murphy GG

2013-10-01

35

Aging and long-term memory for emotionally valenced events.  

UK PubMed Central (United Kingdom)

In 2008, 1103 ardent Boston Red Sox fans answered questions about their team's 2003 loss and 2004 win in baseball championship games with archrival New York Yankees. Contrary to predictions based on socioemotional selectivity theory, there were no significant interactions of age and event valence for accuracy in remembering event details, or for self-reported subjective vividness and rehearsal of the memories. Fans 65 years and older tended to remember feeling only sad about the 2003 loss, whereas fans 25 years and under tended to remember feeling both sad and angry. Individuals may remember emotional feelings based on remembered goals about an event.

Breslin CW; Safer MA

2013-06-01

36

Entanglement Assisted Classical Capacity of a Class of Quantum Channels with Long-Term Memory  

CERN Multimedia

In this paper we evaluate the entanglement assisted classical capacity of a class of quantum channels with long-term memory, which are convex combinations of memoryless channels. The memory of such channels can be considered to be given by a Markov chain which is aperiodic but not irreducible.

Datta, Nilanjana; Dorlas, Tony C

2007-01-01

37

The prion gene is associated with human long-term memory.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Human cognitive processes are highly variable across individuals and are influenced by both genetic and environmental factors. Although genetic variations affect short-term memory in humans, it is unknown whether genetic variability has also an impact on long-term memory. Because prion-like conforma...

Papassotiropoulos, A; Wollmer, M A; Aguzzi, A; Hock, Christoph; Nitsch, R M; de Quervain, D J F

38

Insulin Receptor Signaling in Long-Term Memory Consolidation Following Spatial Learning  

Science.gov (United States)

|Evidence has shown that the insulin and insulin receptor (IR) play a role in cognitive function. However, the detailed mechanisms underlying insulin's action on learning and memory are not yet understood. Here we investigated changes in long-term memory-associated expression of the IR and downstream molecules in the rat hippocampus. After…

Dou, Jing-Tao; Chen, Min; Dufour, Franck; Alkon, Daniel L.; Zhao, Wei-Qin

2005-01-01

39

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

Science.gov (United States)

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…

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

2013-01-01

40

Increased NR2A:NR2B ratio compresses long-term depression range and constrains long-term memory.  

Science.gov (United States)

The NR2A:NR2B subunit ratio of the NMDA receptors is widely known to increase in the brain from postnatal development to sexual maturity and to aging, yet its impact on memory function remains speculative. We have generated forebrain-specific NR2A overexpression transgenic mice and show that these mice had normal basic behaviors and short-term memory, but exhibited broad long-term memory deficits as revealed by several behavioral paradigms. Surprisingly, increased NR2A expression did not affect 1-Hz-induced long-term depression (LTD) or 100?Hz-induced long-term potentiation (LTP) in the CA1 region of the hippocampus, but selectively abolished LTD responses in the 3-5?Hz frequency range. Our results demonstrate that the increased NR2A:NR2B ratio is a critical genetic factor in constraining long-term memory in the adult brain. We postulate that LTD-like process underlies post-learning information sculpting, a novel and essential consolidation step in transforming new information into long-term memory. PMID:23301157

Cui, Zhenzhong; Feng, Ruiben; Jacobs, Stephanie; Duan, Yanhong; Wang, Huimin; Cao, Xiaohua; Tsien, Joe Z

2013-01-08

 
 
 
 
41

Increased NR2A:NR2B ratio compresses long-term depression range and constrains long-term memory.  

UK PubMed Central (United Kingdom)

The NR2A:NR2B subunit ratio of the NMDA receptors is widely known to increase in the brain from postnatal development to sexual maturity and to aging, yet its impact on memory function remains speculative. We have generated forebrain-specific NR2A overexpression transgenic mice and show that these mice had normal basic behaviors and short-term memory, but exhibited broad long-term memory deficits as revealed by several behavioral paradigms. Surprisingly, increased NR2A expression did not affect 1-Hz-induced long-term depression (LTD) or 100?Hz-induced long-term potentiation (LTP) in the CA1 region of the hippocampus, but selectively abolished LTD responses in the 3-5?Hz frequency range. Our results demonstrate that the increased NR2A:NR2B ratio is a critical genetic factor in constraining long-term memory in the adult brain. We postulate that LTD-like process underlies post-learning information sculpting, a novel and essential consolidation step in transforming new information into long-term memory.

Cui Z; Feng R; Jacobs S; Duan Y; Wang H; Cao X; Tsien JZ

2013-01-01

42

Similar autobiographical memory impairment in long-term secondary progressive multiple sclerosis and Alzheimer's disease.  

UK PubMed Central (United Kingdom)

BACKGROUND: Memory disturbance is a common symptom of multiple sclerosis (MS), but little is known about autobiographical memory deficits in the long-term course of different MS subtypes. Inflammatory activity and demyelination is pronounced in relapsing-remitting multiple sclerosis (RRMS) whereas, similar to Alzheimer's disease, neurodegeneration affecting autobiographical memory-associated areas is seen in secondary progressive multiple sclerosis (SPMS). OBJECTIVE: In light of distinct disease mechanisms, we evaluated autobiographical memory in different MS subtypes and hypothesized similarities between elderly patients with SPMS and Alzheimer's disease. METHODS: We used the Autobiographical Memory Interview to assess episodic and semantic autobiographical memory in 112 education- and gender-matched participants, including healthy controls and patients with RRMS, SPMS, amnesic mild cognitive impairment (aMCI) and early Alzheimer's dementia (AD). RESULTS: Patients with SPMS, AD, and aMCI, but not with RRMS, exhibited a pattern of episodic autobiographical memory impairment that followed Ribot's Law; older memories were better preserved than more recent memories. In contrast to aMCI and AD, neither SPMS nor RRMS was associated with semantic autobiographical memory impairment. CONCLUSION: Our neuropsychological findings suggest that episodic autobiographical memory is affected in long-term patients with SPMS, possibly due to neurodegenerative processes in functional relevant brain regions.

Müller S; Saur R; Greve B; Melms A; Hautzinger M; Fallgatter AJ; Leyhe T

2013-02-01

43

Long-Term Effects of Neonatal Single or Multiple Isoflurane Exposures on Spatial Memory in Rats  

Science.gov (United States)

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

Murphy, Kathy L.; Baxter, Mark G.

2013-01-01

44

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

UK PubMed Central (United Kingdom)

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

Murphy KL; Baxter MG

2013-01-01

45

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.

2012-01-00

46

Making long-term memories in minutes: a spaced learning pattern from memory research in education.  

UK PubMed Central (United Kingdom)

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 have been demonstrated in many species. This study reports on using a specific timed pattern of three repeated stimuli separated by 10 min spaces drawn from both behavioral and laboratory studies of LTP and LTM encoding. A technique was developed based on this pattern to test whether encoding complex information into LTM in students was possible using the pattern within a very short time scale. In an educational context, stimuli were periods of highly compressed instruction, and spaces were created through 10 min distractor activities. Spaced Learning in this form was used as the only means of instruction for a national curriculum Biology course, and led to very rapid LTM encoding as measured by the high-stakes test for the course. Remarkably, learning at a greatly increased speed and in a pattern that included deliberate distraction produced significantly higher scores than random answers (p < 0.00001) and scores were not significantly different for experimental groups (one hour spaced learning) and control groups (four months teaching). Thus learning per hour of instruction, as measured by the test, was significantly higher for the spaced learning groups (p < 0.00001). In a third condition, spaced learning was used to replace the end of course review for one of two examinations. Results showed significantly higher outcomes for the course using spaced learning (p < 0.0005). The implications of these findings and further areas for research are briefly considered.

Kelley P; Whatson T

2013-01-01

47

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

Energy Technology Data Exchange (ETDEWEB)

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.

Yong, L [Renmin University of China, Information School (China); Department of Mathematics, Beijing 100872 (China)], E-mail: linyong01@ruc.edu.cn

2008-02-15

48

Does Immediate Imitation Influence Long-Term Memory for Observed Actions?  

Science.gov (United States)

Describes research on young children's long-term memory under 2 conditions of acquisition: direct imitation followed by a 10-minute delay, or deferred imitation. Children were able to encode and retain as much from visual pickup of modeled acts as from feedback obtained through imitation. (Author/GH)

Abravanel, Eugene

1991-01-01

49

Operant Conditioning in Lymnaea: Evidence for Intermediate- and Long-term Memory  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Aerial respiration of the pond snail, Lymnaea stagnalis, can be operantly conditioned; however, the parameters necessary to produce long-term (LTM) or intermediate term memory (ITM) have not previously been investigated. We conducted training using procedures that varied in the duration of the train...

Lukowiak, Ken; Adatia, Nimet; Krygier, Darin; Syed, Naweed

50

Protein Phosphatase 1-Dependent Transcriptional Programs for Long-Term Memory and Plasticity  

Science.gov (United States)

Gene transcription is essential for the establishment and the maintenance of long-term memory (LTM) and for long-lasting forms of synaptic plasticity. The molecular mechanisms that control gene transcription in neuronal cells are complex and recruit multiple signaling pathways in the cytoplasm and the nucleus. Protein kinases (PKs) and…

Graff, Johannes; Koshibu, Kyoko; Jouvenceau, Anne; Dutar, Patrick; Mansuy, Isabelle M.

2010-01-01

51

Automatic and Controlled Processing in Sentence Recall: The Role of Long-Term and Working Memory  

Science.gov (United States)

|Immediate serial recall is better for sentences than word lists presumably because of the additional support that meaningful material receives from long-term memory. This may occur automatically, without the involvement of attention, or may require additional attentionally demanding processing. For example, the episodic buffer model (Baddeley,…

Jefferies, E.; Lambon Ralph, M.A.; Baddeley, A.D.

2004-01-01

52

Hippocampal long-term depression mediates acute stress-induced spatial memory retrieval impairment  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Acute stress impairs memory retrieval and facilitates the induction of long-term depression (LTD) in the hippocampal CA1 region of the adult rodent brain. However, whether such alterations in synaptic plasticity cause the behavioral effects of stress is not known. Here, we report that two selective ...

Wong, Tak Pan; Howland, John G.; Robillard, Julie M.; Ge, Yuan; Yu, Wayne; Titterness, Andrea K.; Brebner, Karen

53

Visual long-term memory stores high-fidelity representations of observed actions.  

UK PubMed Central (United Kingdom)

The ability to remember others' actions is fundamental to social cognition, but the precision of action memories remains unknown. To probe the fidelity of the action representations stored in visual long-term memory, we asked observers to view a large number of computer-animated actions. Afterward, observers were shown pairs of actions and indicated which of the two actions they had seen for each pair. On some trials, the previously viewed action was paired with an action from a different action category, and on other trials, it was paired with an action from the same category. Accuracy on both types of trials was remarkably high (81% and 82%, respectively). Further, results from a second experiment showed that the action representations maintained in visual long-term memory can be nearly as precise as the action representations maintained in visual working memory. Together, these findings provide evidence for a mechanism in visual long-term memory that maintains high-fidelity representations of observed actions.

Urgolites ZJ; Wood JN

2013-04-01

54

On the contribution of binocular disparity to the long-term memory for natural scenes.  

UK PubMed Central (United Kingdom)

Binocular disparity is a fundamental dimension defining the input we receive from the visual world, along with luminance and chromaticity. In a memory task involving images of natural scenes we investigate whether binocular disparity enhances long-term visual memory. We found that forest images studied in the presence of disparity for relatively long times (7s) were remembered better as compared to 2D presentation. This enhancement was not evident for other categories of pictures, such as images containing cars and houses, which are mostly identified by the presence of distinctive artifacts rather than by their spatial layout. Evidence from a further experiment indicates that observers do not retain a trace of stereo presentation in long-term memory.

Valsecchi M; Gegenfurtner KR

2012-01-01

55

Long-term memory of hierarchical relationships in free-living greylag geese.  

UK PubMed Central (United Kingdom)

Animals may memorise spatial and social information for many months and even years. Here, we investigated long-term memory of hierarchically ordered relationships, where the position of a reward depended on the relationship of a stimulus relative to other stimuli in the hierarchy. Seventeen greylag geese (Anser anser) had been trained on discriminations between successive pairs of five or seven implicitly ordered colours, where the higher ranking colour in each pair was rewarded. Geese were re-tested on the task 2, 6 and 12 months after learning the dyadic colour relationships. They chose the correct colour above chance at all three points in time, whereby performance was better in colour pairs at the beginning or end of the colour series. Nonetheless, they also performed above chance on internal colour pairs, which is indicative of long-term memory for quantitative differences in associative strength and/or for relational information. There were no indications for a decline in performance over time, indicating that geese may remember dyadic relationships for at least 6 months and probably well over 1 year. Furthermore, performance in the memory task was unrelated to the individuals' sex and their performance while initially learning the dyadic colour relationships. We discuss possible functions of this long-term memory in the social domain.

Weiss BM; Scheiber IB

2013-01-01

56

Erosion of long-term wall samples in JET  

Energy Technology Data Exchange (ETDEWEB)

The erosion of carbon and the deposition of carbon and impurities have been determined for graphite samples exposed at the wall of JET during the six months of operation in 1985. Graphite erosion was determined using SIMS analysis of the depth change of implanted /sup 13/C marker layers in the samples. Impurity deposition was measured using SIMS and Rutherford backscattering. The samples showed high erosion ranging from 0.2 to 0.6 ..mu..m at various locations, with significant poloidal variation in both erosion and deposition. The deposition of substantial quantities of metal impurities and carbon was related to a probe accident and a deliberate heavy carbonization procedure during the operation period. The highest observed erosion exceeds the expected sputter erosion due to charge exchange neutrals by more than an order of magnitude, unless neutral fluxes are enhanced at the inner wall due to ions arriving along open field lines during current ramp-down.

Roth, J.; Ehrenberg, J.; Wittmaack, K.; Coad, P.; Roberto, J.B.

1987-02-01

57

Nitric oxide-dependent long-term depression but not endocannabinoid-mediated long-term potentiation is crucial for visual recognition memory.  

UK PubMed Central (United Kingdom)

Abstract? Synaptic plasticity in perirhinal cortex is essential for recognition memory. Nitric oxide and endocannabinoids (eCBs), which are produced in the postsynaptic cell and act on the presynaptic terminal, are implicated in mechanisms of long-term potentiation (LTP) and long-term depression (LTD) in other brain regions. In this study, we examine these two retrograde signalling cascades in perirhinal cortex synaptic plasticity and in visual recognition memory in the rat. We show that inhibition of NO-dependent signalling prevented both carbachol- and activity (5 Hz)-dependent LTD but not activity (100 Hz theta burst)-dependent LTP in the rat perirhinal cortex in vitro. In contrast, inhibition of the eCB-dependent signalling prevented LTP but not the two forms of LTD in vitro. Local administration into perirhinal cortex of the nitric oxide synthase inhibitor NPA (2 ?m) disrupted acquisition of long-term visual recognition memory. In contrast, AM251 (10 ?m), a cannabinoid receptor 1 antagonist, did not impair visual recognition memory. The results of this study demonstrate dissociation between putative retrograde signalling mechanisms in LTD and LTP in perirhinal cortex. Thus, LTP relies on cannabinoid but not NO signalling, whilst LTD relies on NO- but not eCB-dependent signalling. Critically, these results also establish, for the first time, that NO- but not eCB-dependent signalling is important in perirhinal cortex-dependent visual recognition memory.

Tamagnini F; Barker G; Warburton EC; Burattini C; Aicardi G; Bashir ZI

2013-08-01

58

Nitric oxide-dependent long-term depression but not endocannabinoid-mediated long-term potentiation is crucial for visual recognition memory.  

Science.gov (United States)

Abstract? Synaptic plasticity in perirhinal cortex is essential for recognition memory. Nitric oxide and endocannabinoids (eCBs), which are produced in the postsynaptic cell and act on the presynaptic terminal, are implicated in mechanisms of long-term potentiation (LTP) and long-term depression (LTD) in other brain regions. In this study, we examine these two retrograde signalling cascades in perirhinal cortex synaptic plasticity and in visual recognition memory in the rat. We show that inhibition of NO-dependent signalling prevented both carbachol- and activity (5 Hz)-dependent LTD but not activity (100 Hz theta burst)-dependent LTP in the rat perirhinal cortex in vitro. In contrast, inhibition of the eCB-dependent signalling prevented LTP but not the two forms of LTD in vitro. Local administration into perirhinal cortex of the nitric oxide synthase inhibitor NPA (2 ?m) disrupted acquisition of long-term visual recognition memory. In contrast, AM251 (10 ?m), a cannabinoid receptor 1 antagonist, did not impair visual recognition memory. The results of this study demonstrate dissociation between putative retrograde signalling mechanisms in LTD and LTP in perirhinal cortex. Thus, LTP relies on cannabinoid but not NO signalling, whilst LTD relies on NO- but not eCB-dependent signalling. Critically, these results also establish, for the first time, that NO- but not eCB-dependent signalling is important in perirhinal cortex-dependent visual recognition memory. PMID:23671159

Tamagnini, Francesco; Barker, Gareth; Warburton, E Clea; Burattini, Costanza; Aicardi, Giorgio; Bashir, Zafar I

2013-05-13

59

Hippocampal long term memory: effect of the cholinergic system on local protein synthesis.  

UK PubMed Central (United Kingdom)

The present study was aimed at establishing a link between the cholinergic system and the pathway of mTOR and its downstream effector p70S6K, likely actors in long term memory encoding. We performed in vivo behavioural experiments using the step down inhibitory avoidance test (IA) in adult Wistar rats to evaluate memory formation under different conditions, and immunohistochemistry on hippocampal slices to evaluate the level and the time-course of mTOR and p70S6K activation. We also examined the effect of RAPA, inhibitor of mTORC1 formation, and of the acetylcholine (ACh) muscarinic receptor antagonist scopolamine (SCOP) or ACh nicotinic receptor antagonist mecamylamine (MECA) on short and long term memory formation and on the functionality of the mTOR pathway. Acquisition test was performed 30 min after i.c.v. injection of RAPA, a time sufficient for the drug to diffuse to CA1 pyramidal neurons, as demonstrated by MALDI-TOF-TOF imaging. Recall test was performed 1 h, 4 h or 24 h after acquisition. To confirm our results we performed in vitro experiments on live hippocampal slices: we evaluated whether stimulation of the cholinergic system with the cholinergic receptor agonist carbachol (CCh) activated the mTOR pathway and whether the administration of the above-mentioned antagonists together with CCh could revert this activation. We found that 1) mTOR and p70S6K activation in the hippocampus were involved in long term memory formation; 2) RAPA administration caused inhibition of mTOR activation at 1 h and 4 h and of p70S6K activation at 4 h, and long term memory impairment at 24 h after acquisition; 3) scopolamine treatment caused short but not long term memory impairment with an early increase of mTOR/p70S6K activation at 1 h followed by stabilization at longer times; 4) mecamylamine plus scopolamine treatment caused short term memory impairment at 1 h and 4 h and reduced the scopolamine-induced increase of mTOR/p70S6K activation at 1 h and 4 h; 5) mecamylamine plus scopolamine treatment did not impair long term memory formation; 6) in vitro treatment with carbachol activated mTOR and p70S6K and this effect was blocked by scopolamine and mecamylamine. Taken together our data reinforce the idea that distinct molecular mechanisms are at the basis of the two different forms of memory and are in accordance with data presented by other groups that there exist molecular mechanisms that underlie short term memory, others that underlie long term memories, but some mechanisms are involved in both.

Lana D; Cerbai F; Russo JD; Boscaro F; Giannetti A; Petkova-Kirova P; Pugliese AM; Giovannini MG

2013-09-01

60

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

UK PubMed Central (United Kingdom)

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 we showed that even as many as 12 primes do not cause long-term semantic priming. In all experiments, however, a repetition priming effect was obtained. The present results are consistent with a number of other results showing that semantic information plays a minimal role in long-term priming in visual word recognition.

Zeelenberg R; Pecher D

2002-03-01

 
 
 
 
61

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

Science.gov (United States)

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 we showed that even as many as 12 primes do not cause long-term semantic priming. In all experiments, however, a repetition priming effect was obtained. The present results are consistent with a number of other results showing that semantic information plays a minimal role in long-term priming in visual word recognition. PMID:11881903

Zeelenberg, René; Pecher, Diane

2002-03-01

62

Impairment of recognition memory and hippocampal long-term potentiation after acute exposure to clioquinol.  

UK PubMed Central (United Kingdom)

Clioquinol (CQ) was associated with cases of transient global amnesia and with the neurodegenerative syndrome subacute myelo-optico-neuropathy (SMON) in humans. However, CQ forms lipophilic chelates with cations and has the potential as a scientific and clinical tool used for selective modulation of histochemically reactive zinc pools. The relationship among transient lack of synaptic zinc release, hippocampal long-term potentiation (LTP) induction and cognitive memory is poorly understood. To evaluate the role of synaptic zinc release, in the present study, hippocampal LTP induction and cognitive behavior were examined in young rats after i.p. injection of CQ (30 mg/kg). Intracellular zinc detected by Timm's stain and extracellular (synaptic cleft) zinc detected by ZnAF-2 were significantly decreased in the hippocampus 6 h after CQ injection. The molecular layer of the dentate gyrus, in which perforant path-granule cell synapses exist, was most responsive to CQ injection. Dentate gyrus LTP was induced similarly to the control 2 h after CQ injection, while significantly attenuated 6-24 h after CQ injection. In the training trial of the object recognition memory 2 h after CQ injection, there was no significant difference in learning behavior between the control and CQ-treated rats. In the test trial, CQ-treated rats showed normal recognition memory 1 h after the training, whereas recognition memory deficit 24 h after the training unlike the control rats. These results indicate that acute exposure to CQ impairs long-term (24 h) memory in the hippocampus of young rats. The CQ-mediated attenuation of dentate gyrus LTP, which may be associated with the transient lack of zinc release from zincergic neurons, seems to be involved in the impairment of the long-term memory.

Takeda A; Takada S; Ando M; Itagaki K; Tamano H; Suzuki M; Iwaki H; Oku N

2010-12-01

63

Impairment of recognition memory and hippocampal long-term potentiation after acute exposure to clioquinol.  

Science.gov (United States)

Clioquinol (CQ) was associated with cases of transient global amnesia and with the neurodegenerative syndrome subacute myelo-optico-neuropathy (SMON) in humans. However, CQ forms lipophilic chelates with cations and has the potential as a scientific and clinical tool used for selective modulation of histochemically reactive zinc pools. The relationship among transient lack of synaptic zinc release, hippocampal long-term potentiation (LTP) induction and cognitive memory is poorly understood. To evaluate the role of synaptic zinc release, in the present study, hippocampal LTP induction and cognitive behavior were examined in young rats after i.p. injection of CQ (30 mg/kg). Intracellular zinc detected by Timm's stain and extracellular (synaptic cleft) zinc detected by ZnAF-2 were significantly decreased in the hippocampus 6 h after CQ injection. The molecular layer of the dentate gyrus, in which perforant path-granule cell synapses exist, was most responsive to CQ injection. Dentate gyrus LTP was induced similarly to the control 2 h after CQ injection, while significantly attenuated 6-24 h after CQ injection. In the training trial of the object recognition memory 2 h after CQ injection, there was no significant difference in learning behavior between the control and CQ-treated rats. In the test trial, CQ-treated rats showed normal recognition memory 1 h after the training, whereas recognition memory deficit 24 h after the training unlike the control rats. These results indicate that acute exposure to CQ impairs long-term (24 h) memory in the hippocampus of young rats. The CQ-mediated attenuation of dentate gyrus LTP, which may be associated with the transient lack of zinc release from zincergic neurons, seems to be involved in the impairment of the long-term memory. PMID:20849933

Takeda, A; Takada, S; Ando, M; Itagaki, K; Tamano, H; Suzuki, M; Iwaki, H; Oku, N

2010-09-16

64

Emotion and long-term memory for duration: resistance against interference.  

UK PubMed Central (United Kingdom)

The aim of this study was to examine the effect of emotion on the long-term memory for duration. On day 1, participants learned a temporal task in a high-arousing or neutral control condition that was followed by a 15-min interference task. Then, 24 h later, on day 2, they were given a test. In this recall test, they judged whether or not comparison durations were similar to the previously learned standard duration. The results showed that temporal discrimination was more accurate in the emotional than in the neutral condition. Emotion thus strengthened memory traces of time by increasing their resistance against interference effects.

Cocenas-Silva R; Bueno JL; Droit-Volet S

2013-07-01

65

Emotion and long-term memory for duration: resistance against interference.  

Science.gov (United States)

The aim of this study was to examine the effect of emotion on the long-term memory for duration. On day 1, participants learned a temporal task in a high-arousing or neutral control condition that was followed by a 15-min interference task. Then, 24 h later, on day 2, they were given a test. In this recall test, they judged whether or not comparison durations were similar to the previously learned standard duration. The results showed that temporal discrimination was more accurate in the emotional than in the neutral condition. Emotion thus strengthened memory traces of time by increasing their resistance against interference effects. PMID:23562667

Cocenas-Silva, Raquel; Bueno, José Lino Oliveira; Droit-Volet, Sylvie

2013-04-02

66

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

UK PubMed Central (United Kingdom)

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

Callaghan CK; Kelly AM

2013-09-01

67

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

Science.gov (United States)

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

Callaghan, Charlotte K; Kelly, Aine M

2013-05-10

68

Chronic treatment with DCPCX, an adenosine A(1) antagonist, worsens long-term memory.  

UK PubMed Central (United Kingdom)

Alzheimer's disease is characterized by progressive cognitive disturbances and neurotransmitter dysfunction. Previous studies targeting the adrenergic A1 pathway suggest that this plays a role in cognitive impairment in Alzheimer's disease. Previous studies have reported that acute treatment with A1 antagonists appears to improve behavioral deficits in rodent models of memory and behavioral impairment. In this study, we addressed whether the chronic administration of 8-cyclopentyl-1,3-dipropylxanthine, a potent and selective adenosine A1 antagonist, could reverse the memory deficits found in aged APPswe/PS1dE9 mice. Chronic treatment did not improve memory in the APPswe/PS1dE9 mouse model and resulted in reduced exploratory behavior, suggestive of reduced anxiety, and a worsening of long-term memory in nontransgenic mice. These results have important implications for understanding the mechanisms of A1 receptor modulation as a target in Alzheimer's disease therapy.

Vollert C; Forkuo GS; Bond RA; Eriksen JL

2013-08-01

69

Short- and long-term components of working memory in the rat.  

UK PubMed Central (United Kingdom)

Previous experiments suggested that working memory of rats trained on a radial maze can be discussed in terms of its short- and long-term temporal components. For example, in Mizumori, Channon, Rosenzweig, and Bennett's (1985) study, long-term working memory was found to be susceptible to disruption by the protein synthesis inhibitor anisomycin (ANI). In Experiment 1 of this report, we examined the neuropharmacological nature of short-term working memory of rats trained to retrieve food from all arms of a 12-arm radial maze. Delay intervals of varying length were placed between Choices 6 and 7. Lanthanum (LaCl3) and glutamate (GLU) injected bilaterally into the hippocampus effectively impaired retention over short delay intervals, which suggests a possible role for calcium and/or potassium and for glutamate in working memory. However, another equally likely explanation for the amnesic effects of LaCl3 and GLU is that these drugs impaired reference memory. To test more directly the hypothesis that LaCl3, GLU, or ANI might differentially affect working and reference memory, we tested the effects of these drugs on performance of rats trained to retrieve food from only 8 arms of the 12-arm maze in Experiment 2. The remaining 4 arms were never baited, in order to test reference memory function. We predicted that rats would make errors only in baited arms (i.e., errors of working memory). Instead, results of Experiment 2 showed that LaCl3, GLU, or ANI injection produced errors in unbaited arms even before a 120-min delay. If rats were injected with LaCl3 or GLU, baited-arm errors were observed only after the delay period.(ABSTRACT TRUNCATED AT 250 WORDS)

Mizumori SJ; Channon V; Rosenzweig MR; Bennett EL

1987-12-01

70

Repetitive fluoxetine treatment affects long-term memories but not learning.  

Science.gov (United States)

Fluoxetine is currently being administered for long-term maintenance and for prophylactic reasons following the remission of depressive symptoms and several other psychiatric and neurological conditions. We have previously found that in naïve adult male rats, repetitive administration of fluoxetine induced maturation of telencephalic dendritic spines. This finding was associated with the presence of a higher proportion of GluA2- and GluN2A-containing glutamate receptors. To gain further insight into the possible consequences of such synaptic re-organization on learning and memory processes, we evaluated hippocampal- and non-hippocampal-dependent memories following administration of 0.7 mg/kg fluoxetine for four weeks. Standard behavioral tasks were used: the Morris Water Maze (MWM) and Object Location Memory (OLM) tasks to assess spatial memory and the Novel Object Recognition (NOR) task to assess recognition memory. We found that treated rats showed normal learning and short-term memory (1 h post-learning). However, either recent (24 h) or remote (17 days) memories were impaired depending upon the task. Interestingly, spatial memory impairment spontaneously reverted after 6 weeks of fluoxetine withdrawal. PMID:23511254

Ampuero, Estibaliz; Stehberg, Jimmy; Gonzalez, Daniela; Besser, Nicolas; Ferrero, Monica; Diaz-Veliz, Gabriela; Wyneken, Ursula; Rubio, Francisco Javier

2013-03-16

71

Does immediate imitation influence long-term memory for observed actions?  

UK PubMed Central (United Kingdom)

Long-term memory for object-related information acquired observationally was studied among younger and older toddlers under two conditions of acquisition and retention: direct imitation followed by reproduction after a 10 min delay (delayed imitation), and deferred imitation. A principal aim was to determine whether direct imitation fosters a form of enactive representation that improves long-term memory, or whether such memory is influenced more by visual encoding factors. Tasks consisted of five simple action combinations or separations. Results indicated that post-test scores were higher under all three post-test conditions than under pretest. Likewise, post-test performance was higher than that of a comparison group that did not observe the target actions. The results overall indicate that direct imitation did not operate substantially to improve memory for the modelled acts. Children were able to encode and retain about as much from their visual pickup of the modeled acts as from feedback obtained through the process of imitation. This finding was especially true for the older children.

Abravanel E

1991-04-01

72

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

Directory of Open Access Journals (Sweden)

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

A. Rashidy-Pour; A.A. Taherian; A.A. Vafaei; H. Miladi-Gorji; H. Sadeghi; Y. Fathollahi; A.R. Bandehgi

2006-01-01

73

Drosophila amyloid precursor protein-like is required for long-term memory.  

UK PubMed Central (United Kingdom)

The amyloid precursor protein (APP) plays an important role in Alzheimer's disease (AD), a progressive neurodegenerative pathology that first manifests as a decline of memory. While the main hypothesis for AD pathology centers on the proteolytic processing of APP, very little is known about the physiological function of the APP protein in the adult brain. Likewise, whether APP loss of function contributes to AD remains unclear. Drosophila has been used extensively as a model organism to study neuronal function and pathology. In addition, many of the molecular mechanisms underlying memory are thought to be conserved from flies to mammals, prompting us to study the function of APPL, the fly APP ortholog, during associative memory. It was previously shown that APPL expression is highly enriched in the mushroom bodies (MBs), a specialized brain structure involved in olfactory memory. We analyzed memory in flies in which APPL expression has been silenced specifically and transiently in the adult MBs. Our results show that in adult flies, APPL is not required for learning but is specifically involved in long-term memory, a long lasting memory whose formation requires de novo protein synthesis and is thought to require synaptic structural plasticity. These data support the hypothesis that disruption of normal APP function may contribute to early AD cognitive impairment.

Goguel V; Belair AL; Ayaz D; Lampin-Saint-Amaux A; Scaplehorn N; Hassan BA; Preat T

2011-01-01

74

Drosophila amyloid precursor protein-like is required for long-term memory.  

Science.gov (United States)

The amyloid precursor protein (APP) plays an important role in Alzheimer's disease (AD), a progressive neurodegenerative pathology that first manifests as a decline of memory. While the main hypothesis for AD pathology centers on the proteolytic processing of APP, very little is known about the physiological function of the APP protein in the adult brain. Likewise, whether APP loss of function contributes to AD remains unclear. Drosophila has been used extensively as a model organism to study neuronal function and pathology. In addition, many of the molecular mechanisms underlying memory are thought to be conserved from flies to mammals, prompting us to study the function of APPL, the fly APP ortholog, during associative memory. It was previously shown that APPL expression is highly enriched in the mushroom bodies (MBs), a specialized brain structure involved in olfactory memory. We analyzed memory in flies in which APPL expression has been silenced specifically and transiently in the adult MBs. Our results show that in adult flies, APPL is not required for learning but is specifically involved in long-term memory, a long lasting memory whose formation requires de novo protein synthesis and is thought to require synaptic structural plasticity. These data support the hypothesis that disruption of normal APP function may contribute to early AD cognitive impairment. PMID:21248128

Goguel, Valérie; Belair, Anne-Laure; Ayaz, Derya; Lampin-Saint-Amaux, Aurélie; Scaplehorn, Niki; Hassan, Bassem A; Preat, Thomas

2011-01-19

75

Stress within a restricted time window selectively affects the persistence of long-term memory.  

UK PubMed Central (United Kingdom)

The effects of stress on emotional memory are distinct and depend on the stages of memory. Memory undergoes consolidation and reconsolidation after acquisition and retrieval, respectively. Stress facilitates the consolidation but disrupts the reconsolidation of emotional memory. Previous research on the effects of stress on memory have focused on long-term memory (LTM) formation (tested 24 h later), but the effects of stress on the persistence of LTM (tested at least 1 week later) are unclear. Recent findings indicated that the persistence of LTM requires late-phase protein synthesis in the dorsal hippocampus. The present study investigated the effect of stress (i.e., cold water stress) during the late phase after the acquisition and retrieval of contextual fear memory in rats. We found that stress and corticosterone administration during the late phase (12 h) after acquisition, referred to as late consolidation, selectively enhanced the persistence of LTM, whereas stress during the late phase (12 h) after retrieval, referred to as late reconsolidation, selectively disrupted the restabilized persistence of LTM. Moreover, the effects of stress on the persistence of LTM were blocked by the corticosterone synthesis inhibitor metyrapone, which was administered before stress, suggesting that the glucocorticoid system is involved in the effects of stress on the persistence of LTM. We conclude that stress within a restricted time window after acquisition or retrieval selectively affects the persistence of LTM and depends on the glucocorticoid system.

Yang C; Liu JF; Chai BS; Fang Q; Chai N; Zhao LY; Xue YX; Luo YX; Jian M; Han Y; Shi HS; Lu L; Wu P; Wang JS

2013-01-01

76

Statistical traces of long-term memories stored in strengths and patterns of synaptic connections.  

UK PubMed Central (United Kingdom)

Learning and long-term memory rely on plasticity of neural circuits. In adult cerebral cortex, plasticity can result from potentiation and depression of synaptic strengths and structural reorganization of circuits through growth and retraction of dendritic spines. By analyzing 166 distributions of spine head volumes and spine lengths from mouse, rat, monkey, and human brains, we determine the "generalized cost" of dendritic spines. This cost universally depends on spine shape, i.e., the dependence is the same in all the analyzed systems. We show that, in adult, synaptic strength and structural synaptic plasticity mechanisms are in statistical equilibrium, the numbers of dendritic spines in different cortical areas are nearly optimally chosen for memory storage, and the distributions of spine lengths and head volumes are governed by a single parameter--the effective temperature. We suggest that the effective temperature may be viewed as a measure of circuit stability or longevity of stored memories.

Stepanyants A; Escobar G

2011-05-01

77

Statistical traces of long-term memories stored in strengths and patterns of synaptic connections.  

Science.gov (United States)

Learning and long-term memory rely on plasticity of neural circuits. In adult cerebral cortex, plasticity can result from potentiation and depression of synaptic strengths and structural reorganization of circuits through growth and retraction of dendritic spines. By analyzing 166 distributions of spine head volumes and spine lengths from mouse, rat, monkey, and human brains, we determine the "generalized cost" of dendritic spines. This cost universally depends on spine shape, i.e., the dependence is the same in all the analyzed systems. We show that, in adult, synaptic strength and structural synaptic plasticity mechanisms are in statistical equilibrium, the numbers of dendritic spines in different cortical areas are nearly optimally chosen for memory storage, and the distributions of spine lengths and head volumes are governed by a single parameter--the effective temperature. We suggest that the effective temperature may be viewed as a measure of circuit stability or longevity of stored memories. PMID:21613479

Stepanyants, Armen; Escobar, Gina

2011-05-25

78

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

UK PubMed Central (United Kingdom)

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 (<7 min) and followed by an ?45 min period during which the adhesion receptors did not respond to a second application of TBS. Brefeldin A, which blocks integrin trafficking to the plasma membrane, prevented the delayed recovery of integrin responses to TBS. ?1 integrin-neutralizing antisera erased LTP when applied during, but not after, the return of integrin responsivity. Similarly, infusions of anti-?1 into rostral mouse hippocampus blocked formation of long-term, object location memory when started 20 min after learning but not 40 min later. The finding that ?1 integrin neutralization was effective in the same time window for slice and behavioral experiments strongly suggests that integrin recovery triggers a temporally discrete, previously undetected second stage of consolidation for both LTP and memory.

Babayan AH; Kramár EA; Barrett RM; Jafari M; Häettig J; Chen LY; Rex CS; Lauterborn JC; Wood MA; Gall CM; Lynch G

2012-09-01

79

Long-term and within-day variability of working memory performance and EEG in individuals.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Assess individual-subject long-term and within-day variability of a combined behavioral and EEG test of working memory. METHODS: EEGs were recorded from 16 adults performing n-back working memory tasks, with 10 tested in morning and afternoon sessions over several years. Participants were also tested after ingesting non-prescription medications or recreational substances. Performance and EEG measures were analyzed to derive an Overall score and three constituent sub-scores characterizing changes in performance, cortical activation, and alertness from each individual's baseline. Long-term and within-day variability were determined for each score; medication effects were assessed by reference to each individual's normal day-to-day variability. RESULTS: Over the several year period, the mean Overall score and sub-scores were approximately zero with standard deviations less than one. Overall scores were lower and their variability higher in afternoon relative to morning sessions. At the group level, alcohol, diphenhydramine and marijuana produced significant effects, but there were large individual differences. CONCLUSIONS: Objective working memory measures incorporating performance and EEG are stable over time and sensitive at the level of individual subjects to interventions that affect neurocognitive function. SIGNIFICANCE: With further research these measures may be suitable for use in individualized medical care by providing a sensitive assessment of incipient illness and response to treatment.

Gevins A; McEvoy LK; Smith ME; Chan CS; Sam-Vargas L; Baum C; Ilan AB

2012-07-01

80

PKA and PKC Are Required for Long-Term but Not Short-Term in Vivo Operant Memory in "Aplysia"  

Science.gov (United States)

We investigated the involvement of PKA and PKC signaling in a negatively reinforced operant learning paradigm in "Aplysia", learning that food is inedible (LFI). In vivo injection of PKA or PKC inhibitors blocked long-term LFI memory formation. Moreover, a persistent phase of PKA activity, although not PKC activity, was necessary for long-term

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

2011-01-01

 
 
 
 
81

Testing long-term memory in animal models of schizophrenia: Suggestions from CNTRICS.  

UK PubMed Central (United Kingdom)

This paper reports the results of discussions at the fourth meeting of Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS) meeting, held over two days in Washington, DC in April 2011. The meeting focused on animal paradigms for assessing the cognitive constructs relevant to schizophrenia identified in previous CNTRICS meetings. This report focuses on the outcome of discussions in the general area of long-term memory. A number of candidate animal paradigms were discussed. Two of these - one for rodents and one for non-human primates - were recommended as particularly promising for further development.

Bussey TJ; Barch DM; Baxter MG

2013-06-01

82

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

Directory of Open Access Journals (Sweden)

Full Text Available Long-term potentiation (LTP) is the enhancement of postsynaptic responses for hours, days or weeks following the brief repetitive afferent stimulation of presynaptic afferents. It has been proposed many times over the last 30 years to be the basis of long-term memory. Several recent findings finally supported this hypothesis: a) memory formation of one-trial avoidance learning depends on a series of molecular steps in the CA1 region of the hippocampus almost identical to those of LTP in the same region; 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.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.

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

2008-01-01

83

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A potenciação de longa duração (LTP) é o aumento de respostas pós-sinápticas durante horas, dias ou semanas após a breve estimulação repetitiva de aferentes pre-sinápticos. Foi proposto durante 30 anos ser a base da memória de longa duração. Vários achados recentes finalmente apoiaram esta hipótese: a) a formação da memória de esquiva inibitória adquirida numa sessão depende de uma cadeia de processos moleculares na região CA1 do hipocampo quase idê (more) ntica 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 (more) 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.

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

2008-03-01

84

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)).

2007-07-13

85

Attention in direct and indirect memory tasks with short- and long-term probes.  

UK PubMed Central (United Kingdom)

In two experiments, college students verified the answers to addition problems as their primary task while simultaneously viewing a word or nonword. The degree of attention allocated to the verbal stimulus varied depending on the difficulty of the problem and the instructions given. After each problem, a test probe assessed either a direct test of recognition memory or an indirect test of repetition priming in lexical decision at lags of 0, 1, or 8 intervening trials. The degree of attention at encoding and lag strongly affected recognition sensitivity (d'), but only lag affected recognition latencies. The repetition-priming effect neither declined with lag nor varied with the degree of attention. The degree of attention at encoding thus affects direct and indirect test performance differentially, a finding consistent with the distinction between explicit and implicit systems of long-term memory.

Kellogg RT; Newcombe C; Kammer D; Schmitt K

1996-01-01

86

Requirement for nuclear calcium signaling in Drosophila long-term memory.  

UK PubMed Central (United Kingdom)

Calcium is used throughout evolution as an intracellular signal transducer. In the mammalian central nervous system, calcium mediates the dialogue between the synapse and the nucleus that is required for transcription-dependent persistent neuronal adaptations. A role for nuclear calcium signaling in similar processes in the invertebrate brain has yet to be investigated. Here, we show by in vivo calcium imaging of adult brain neurons of the fruit fly Drosophila melanogaster, that electrical foot shocks used in olfactory avoidance conditioning evoked transient increases in cytosolic and nuclear calcium concentrations in neurons. These calcium signals were detected in Kenyon cells of the flies' mushroom bodies, which are sites of learning and memory related to smell. Acute blockade of nuclear calcium signaling during conditioning selectively and reversibly abolished the formation of long-term olfactory avoidance memory, whereas short-term, middle-term, or anesthesia-resistant olfactory memory remained unaffected. Thus, nuclear calcium signaling is required in flies for the progression of memories from labile to transcription-dependent long-lasting forms. These results identify nuclear calcium as an evolutionarily conserved signal needed in both invertebrate and vertebrate brains for transcription-dependent memory consolidation.

Weislogel JM; Bengtson CP; Müller MK; Hörtzsch JN; Bujard M; Schuster CM; Bading H

2013-05-01

87

Basolateral amygdala lesions block the disruptive effects of long-term adrenalectomy on spatial memory.  

UK PubMed Central (United Kingdom)

The present study examined, in rats with N-methyl-D-aspartate-induced lesions of the basolateral amygdala, the effects of long-term adrenalectomy (i.e. 12-13 weeks) on memory for spatial and cued learning in a water maze. In sham amygdala-lesioned rats, adrenalectomy induced impairments in acquisition and retention performance for the spatial, but not the cued water-maze task. The adrenalectomized rats sustained selective degeneration and death of granule cells in the dentate gyrus dorsal blade. Continuous supplementation of the animals' drinking water with an extremely low dose of corticosterone (20 microg/ml) did not block the retention deficit, but blocked the acquisition deficit and the dentate gyrus neurodegenerative changes. The finding that the memory impairments and dentate gyrus neurodegeneration are dissociable supports the view that the adrenalectomy-induced memory effects are due to the loss of activational effects of circulating adrenal hormones at the time of learning. In adrenalectomized rats which received corticosterone as well as those which did not, lesions of the basolateral amygdala blocked the impairing effects of adrenalectomy on spatial learning and memory. However, the basolateral amygdala lesions did not affect the neurodegenerative changes in the dentate gyrus. In conclusion, the present findings provide further evidence that the basolateral amygdala is involved in regulating stress hormone effects on learning and memory.

Roozendaal B; Sapolsky RM; McGaugh JL

1998-05-01

88

[Memory and metamemory during transient global amnesia: a comparative study about long-term follow up].  

UK PubMed Central (United Kingdom)

INTRODUCTION: Diagnostic criteria of transient global amnesia (TGA) establishes that memory functioning has to be recovered in 24 hours. However, there are contradictory data about the existence of long-term sequelae. Furthermore, there is no consensus about which is the most suitable tool in order to use in the assessment of the follow up of these patients. AIMS: To assess episodic memory of TGA patients during amnesic episode and 7, 30 and 90 days after with free recall and Mini-Mental tasks. Moreover, it has been measured patient's metamemory. SUBJECTS AND METHODS: 17 TGA patients and 17 healthy volunteers, matched by age, sex, and educational level were assessed. A longitudinal (four assessments) and factorial (patients and control group) study was carried out. RESULTS: During TGA, free recall and Mini-Mental tasks were significantly affected. However, only free recall task showed improvement along time and impairment after three months. It has been also detected that metamemory of TGA patients is imprecise. CONCLUSIONS: Comparing with control group, both free recall and Mini-Mental tasks have significant lower levels during TGA, but only the first one is sensitive enough to show long-term disturbance associated with this amnesia.

Marín-García E; Ruiz-Vargas JM

2011-07-01

89

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

CERN Multimedia

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...

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

2006-01-01

90

Quantitative Analysis of Long-Term Virus-Specific CD8+-T-Cell Memory in Mice Challenged with Unrelated Pathogens  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The consequences for the long-term maintenance of virus-specific CD8+-T-cell memory have been analyzed experimentally for sequential respiratory infections with readily eliminated (influenza virus) and persistent (gammaherpesvirus 68 [?HV68]) pathogens. Sampling a broad range of tissue sites establi...

Liu, Haiyan; Andreansky, Samita; Diaz, Gabriela; Turner, Stephen J.; Wodarz, Dominik; Doherty, Peter C.

91

Dual effect of morphine in long-term social memory in rat.  

UK PubMed Central (United Kingdom)

BACKGROUND AND PURPOSE: Bimodal dose-response relationships have been demonstrated in animals and humans following morphine administration. We examined if systemic administration of morphine, in extremely low (?g) and high (mg, analgesic) doses, changed the learning process. EXPERIMENTAL APPROACH: In the social learning test, an adult rat investigates a juvenile. The juvenile is submitted to a second encounter after a few days and investigation by the adult should be reduced. Morphine was administered before the first encounter between rats, and the critical test was performed 24, 72 or 168 h later, when animals were re-exposed to each other, in the absence of morphine. KEY RESULTS: Low doses of morphine, comparable with endogenous brain concentrations, enhanced long-term memory recognition; while high doses did the reverse, indicating the adult failed to recognize the juvenile. Recognition of a familiar rat appeared to be mediated within the brain accessory olfactory bulb (AOB) by an opioid system intrinsic to the olfactory system through ?-opioid receptors (MORs). At this supraspinal site, the PLC/PKC signalling pathway was activated by extremely low morphine doses. CONCLUSIONS AND IMPLICATIONS: Morphine treatment administration may either disrupt or facilitate social memory, depending on the dose, extending to memory formation the bimodal effects of morphine previously shown in pain. Social memory formation elicited by extremely low morphine doses, was mediated within the AOB by an opioid system, intrinsic to the olfactory system through MORs.

Bianchi E; Menicacci C; Ghelardini C

2013-04-01

92

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

Directory of Open Access Journals (Sweden)

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

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

2006-01-01

93

Episodic long-term memory of spoken discourse masked by speech: what is the role for working memory capacity?  

UK PubMed Central (United Kingdom)

PURPOSE: To investigate whether working memory capacity (WMC) modulates the effects of to-be-ignored speech on the memory of materials conveyed by to-be-attended speech. METHOD: Two tasks (reading span, Daneman & Carpenter, 1980; Rönnberg et al., 2008; and size-comparison span, Sörqvist, Ljungberg, & Ljung, 2010) were used to measure individual differences in WMC. Episodic long-term memory of spoken discourse was measured by requesting participants to listen to stories masked either by normal speech or by a rotated version of that speech and to subsequently answer questions on the content of the stories. RESULTS: Normal speech impaired performance on the episodic long-term memory test, and both WMC tasks were negatively related to this effect, indicating that individuals with high WMC are less susceptible to disruption. Moreover, further analyses revealed that size-comparison span (a task that requires resolution of semantic confusion by inhibition processes) is a stronger predictor of the effect than is reading span. CONCLUSIONS: Cognitive control processes support listening in adverse conditions. In particular, inhibition processes acting to resolve semantic confusion seem to underlie the relationship between WMC and susceptibility to distraction from masking speech.

Sörqvist P; Rönnberg J

2012-02-01

94

Modafinil, but not escitalopram, improves working memory and sustained attention in long-term, high-dose cocaine users.  

UK PubMed Central (United Kingdom)

OBJECTIVE: The purpose of the present study was to determine the effects of modafinil, escitalopram, and modafinil + escitalopram administration on neurocognition in a sample of long-term, high-dose cocaine users. METHOD: Sixty-one cocaine-dependent individuals were randomly assigned to receive placebo (n = 14), modafinil, 200 mg, once daily (n = 16), escitalopram, 20 mg, once daily (n = 16), or modafinil and escitalopram, once daily (n = 15), for five days on an inpatient basis. Urinanalysis was used to confirm abstinence from cocaine on the day of admission and the next five days. Baseline neurocognitive assessment, which included measures of attention/information processing, episodic memory, and working memory, was conducted immediately after the washout phase and prior to the administration of modafinil. The follow-up assessment was conducted after participants had received modafinil or placebo for five days. RESULTS: Repeated-measures, mixed model analysis of variance showed that modafinil administration was associated with significantly improved performance on two measures of working memory span (mean n-back span, maximum n-back span) and a trend toward significant improvement on a measure of visual working memory (visual accuracy) and two measures of sustained attention, consistency of response time (Variability) and reduced impulsivity (Perseveration). Modafinil administration did not modulate performance on measures of information processing speed or episodic memory. Escitalopram did not modulate performance on measures of cognition, either alone or in combination with modafinil. CONCLUSIONS: This study provides initial data showing that, in a sample of long-term, high-dose cocaine users, administration of psychotropic medications, such as modafinil, can improve performance on measures of working memory. Moreover, it confirms the utility of studying the interactive effects of psychotropic medications to confirm the manner in which the candidate medications independently and interactively affect neurocognition. These effects are likely relevant in the treatment of cocaine dependence, in which the remediation of impaired working memory may be associated with improved treatment outcomes. This article is part of a Special Issue entitled 'Cognitive Enhancers'.

Kalechstein AD; Mahoney JJ 3rd; Yoon JH; Bennett R; De la Garza R 2nd

2013-01-01

95

A novel whole-cell mechanism for long-term memory enhancement.  

UK PubMed Central (United Kingdom)

Olfactory-discrimination learning was shown to induce a profound long-lasting enhancement in the strength of excitatory and inhibitory synapses of pyramidal neurons in the piriform cortex. Notably, such enhancement was mostly pronounced in a sub-group of neurons, entailing about a quarter of the cell population. Here we first show that the prominent enhancement in the subset of cells is due to a process in which all excitatory synapses doubled their strength and that this increase was mediated by a single process in which the AMPA channel conductance was doubled. Moreover, using a neuronal-network model, we show how such a multiplicative whole-cell synaptic strengthening in a sub-group of cells that form a memory pattern, sub-serves a profound selective enhancement of this memory. Network modeling further predicts that synaptic inhibition should be modified by complex learning in a manner that much resembles synaptic excitation. Indeed, in a subset of neurons all GABAA-receptors mediated inhibitory synapses also doubled their strength after learning. Like synaptic excitation, Synaptic inhibition is also enhanced by two-fold increase of the single channel conductance. These findings suggest that crucial learning induces a multiplicative increase in strength of all excitatory and inhibitory synapses in a subset of cells, and that such an increase can serve as a long-term whole-cell mechanism to profoundly enhance an existing Hebbian-type memory. This mechanism does not act as synaptic plasticity mechanism that underlies memory formation but rather enhances the response of already existing memory. This mechanism is cell-specific rather than synapse-specific; it modifies the channel conductance rather than the number of channels and thus has the potential to be readily induced and un-induced by whole-cell transduction mechanisms.

Reuveni I; Saar D; Barkai E

2013-01-01

96

Dietary cholesterol degrades rabbit long term memory for discrimination learning but facilitates acquisition of discrimination reversal.  

UK PubMed Central (United Kingdom)

We have shown previously that feeding dietary cholesterol before learning can improve acquisition whereas feeding cholesterol after learning can degrade long term memory. To examine these different findings within a single paradigm, we fed groups of rabbits 2% cholesterol or normal chow with or without 0.12ppm copper added to the drinking water following two-tone discrimination learning of the nictitating membrane response in which a 8-kHz tone (conditioned stimulus, CS+) was followed by air puff and a 1-kHz tone (CS-) was not. After eight weeks on the diet, we assessed the rabbits' conditioned responding during testing and retraining. We then reversed the two-tone discrimination and assessed responding to the 1-kHz tone CS+and the 8-kHz CS-. During testing, rabbits given cholesterol without copper had lower levels of responding to CS+than rabbits in the other groups suggesting they did not retain the discrimination as well. However, during a brief discrimination retraining session, their response levels to the CS+returned to the level of the other groups, demonstrating a return of the memory of the original discrimination. At the end of discrimination reversal, these same rabbits exhibited superior discrimination indexed by lower response levels to CS- but similar levels to CS+, suggesting they were better able to acquire the new relationship between the two tones by inhibiting CS- responses. These results add to our previous data by showing cholesterol diet-induced degradation of an old memory and facilitation of a new memory can both be demonstrated within a discrimination reversal paradigm. Given discrimination reversal is a hippocampally-dependent form of learning, the data support the role of cholesterol in modifying hippocampal function as we have shown previously with in vitro brain slice recordings.

Schreurs BG; Smith-Bell CA; Wang D; Burhans LB

2013-09-01

97

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

UK PubMed Central (United Kingdom)

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 < 0.05). During the weeks 1-3 and 6-9, they were close to each other. The hippocampal neurons showed irregular firing patterns and more spikes with shorter interspike interval during the whole experiment period. It indicates that the 916 MHz EMF influence learning and memory in rats to some extent in a period during exposure, and the rats can adapt to long-term EMF exposure.

Hao D; Yang L; Chen S; Tong J; Tian Y; Su B; Wu S; Zeng Y

2013-02-01

98

Divergent short- and long-term effects of acute stress in object recognition memory are mediated by endogenous opioid system activation.  

UK PubMed Central (United Kingdom)

Acute stress induces short-term object recognition memory impairment and elicits endogenous opioid system activation. The aim of this study was thus to evaluate whether opiate system activation mediates the acute stress-induced object recognition memory changes. Adult male Wistar rats were trained in an object recognition task designed to test both short- and long-term memory. Subjects were randomly assigned to receive an intraperitoneal injection of saline, 1mg/kg naltrexone or 3mg/kg naltrexone, four and a half hours before the sample trial. Five minutes after the injection, half the subjects were submitted to movement restraint during four hours while the other half remained in their home cages. Non-stressed subjects receiving saline (control) performed adequately during the short-term memory test, while stressed subjects receiving saline displayed impaired performance. Naltrexone prevented such deleterious effect, in spite of the fact that it had no intrinsic effect on short-term object recognition memory. Stressed subjects receiving saline and non-stressed subjects receiving naltrexone performed adequately during the long-term memory test; however, control subjects as well as stressed subjects receiving a high dose of naltrexone performed poorly. Control subjects' dissociated performance during both memory tests suggests that the short-term memory test induced a retroactive interference effect mediated through light opioid system activation; such effect was prevented either by low dose naltrexone administration or by strongly activating the opioid system through acute stress. Both short-term memory retrieval impairment and long-term memory improvement observed in stressed subjects may have been mediated through strong opioid system activation, since they were prevented by high dose naltrexone administration. Therefore, the activation of the opioid system plays a dual modulating role in object recognition memory.

Nava-Mesa MO; Lamprea MR; Múnera A

2013-09-01

99

Propranolol's effects on the consolidation and reconsolidation of long-term emotional memory in healthy participants: a meta-analysis.  

UK PubMed Central (United Kingdom)

BACKGROUND: Considering the pivotal role of negative emotional experiences in the development and persistence of mental disorders, interfering with the consolidation/reconsolidation of such experiences would open the door to a novel treatment approach in psychiatry. We conducted a meta-analysis on the experimental evidence regarding the capacity of the ß-blocker propranolol to block the consolidation/reconsolidation of emotional memories in healthy adults. METHODS: Selected studies consisted of randomized, double-blind experiments assessing long-term memory for emotional material in healthy adults and involved at least 1 propranolol and 1 placebo condition. We searched PsycInfo, PubMed, Web of Science, Cochrane Central, PILOTS, Google Scholar and clinicaltrials.org for eligible studies from the period 1995-2012. Ten consolidation (n = 259) and 8 reconsolidation (n = 308) experiments met the inclusion criteria. We calculated effect sizes (Hedges g) using a random effects model. RESULTS: Compared with placebo, propranolol given before memory consolidation reduced subsequent recall for negatively valenced stories, pictures and word lists (Hedges g = 0.44, 95% confidence interval [CI] 0.14-0.74). Propranolol before reconsolidation also reduced subsequent recall for negatively valenced emotional words and the expression of cue-elicited fear responses (Hedges g = 0.56, 95% CI 0.13-1.00). LIMITATIONS: Limitations include the moderate number of studies examining the influence of propranolol on emotional memory consolidation and reconsolidation in healthy adults and the fact that most samples consisted entirely of young adults, which may limit the ecological validity of results. CONCLUSION: Propranolol shows promise in reducing subsequent memory for new or recalled emotional material in healthy adults. However, future studies will need to investigate whether more powerful idiosyncratic emotional memories can also be weakened and whether this weakening can bring about long-lasting symptomatic relief in clinical populations, such as patients with posttraumatic stress or other event-related disorders.

Lonergan MH; Olivera-Figueroa LA; Pitman RK; Brunet A

2013-07-01

100

Propranolol's effects on the consolidation and reconsolidation of long-term emotional memory in healthy participants: a meta-analysis  

Science.gov (United States)

Background Considering the pivotal role of negative emotional experiences in the development and persistence of mental disorders, interfering with the consolidation/reconsolidation of such experiences would open the door to a novel treatment approach in psychiatry. We conducted a meta-analysis on the experimental evidence regarding the capacity of the ?-blocker propranolol to block the consolidation/reconsolidation of emotional memories in healthy adults. Methods Selected studies consisted of randomized, double-blind experiments assessing long-term memory for emotional material in healthy adults and involved at least 1 propranolol and 1 placebo condition. We searched PsycInfo, PubMed, Web of Science, Cochrane Central, PILOTS, Google Scholar and clinicaltrials.org for eligible studies from the period 1995–2012. Ten consolidation (n = 259) and 8 reconsolidation (n = 308) experiments met the inclusion criteria. We calculated effect sizes (Hedges g) using a random effects model. Results Compared with placebo, propranolol given before memory consolidation reduced subsequent recall for negatively valenced stories, pictures and word lists (Hedges g = 0.44, 95% confidence interval [CI] 0.14–0.74). Propranolol before reconsolidation also reduced subsequent recall for negatively valenced emotional words and the expression of cue-elicited fear responses (Hedges g = 0.56, 95% CI 0.13–1.00). Limitations Limitations include the moderate number of studies examining the influence of propranolol on emotional memory consolidation and reconsolidation in healthy adults and the fact that most samples consisted entirely of young adults, which may limit the ecological validity of results. Conclusion Propranolol shows promise in reducing subsequent memory for new or recalled emotional material in healthy adults. However, future studies will need to investigate whether more powerful idiosyncratic emotional memories can also be weakened and whether this weakening can bring about long-lasting symptomatic relief in clinical populations, such as patients with posttraumatic stress or other event-related disorders.

Lonergan, Michelle H.; Olivera-Figueroa, Lening A.; Pitman, Roger K.; Brunet, Alain

2013-01-01

 
 
 
 
101

Event-related functional magnetic resonance imaging of a low dose of dexmedetomidine that impairs long-term memory.  

UK PubMed Central (United Kingdom)

BACKGROUND: Work suggests the amnesia from dexmedetomidine (an ?2-adrenergic agonist) is caused by a failure of information to be encoded into long-term memory and that dexmedetomidine might differentially affect memory for emotionally arousing material. We investigated these issues in humans using event-related neuroimaging to reveal alterations in brain activity and subsequent memory effects associated with drug exposure. METHODS: Forty-eight healthy volunteers received a computer-controlled infusion of either placebo or low-dose dexmedetomidine (target = 0.15 ng/ml plasma) during neuroimaging while they viewed and rated 80 emotionally arousing (e.g., graphic war wound) and 80 nonarousing neutral (e.g., cup) pictures for emotional arousal content. Long-term picture memory was tested 4 days later without neuroimaging. Imaging data were analyzed for drug effects, emotional processing differences, and memory-related changes with statistical parametric mapping-8. RESULTS: Dexmedetomidine impaired overall (mean ± SEM) picture memory (placebo: 0.58 ± 0.03 vs. dexmedetomidine: 0.45 ± 0.03, P = 0.001), but did not differentially modulate memory as a function of item arousal. Arousing pictures were better remembered for both groups. Dexmedetomidine had regionally heterogeneous effects on brain activity, primarily decreasing it in the cortex and increasing it in thalamic and posterior hippocampal regions. Nevertheless, a single subsequent memory effect for item memory common to both groups was identified only in the left hippocampus/amygdala. Much of this effect was found to be larger for the placebo than dexmedetomidine group. CONCLUSION: Dexmedetomidine impaired long-term picture memory, but did not disproportionately block memory for emotionally arousing items. The memory impairment on dexmedetomidine corresponds with a weakened hippocampal subsequent memory effect.

Hayama HR; Drumheller KM; Mastromonaco M; Reist C; Cahill LF; Alkire MT

2012-11-01

102

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

Directory of Open Access Journals (Sweden)

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

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

2005-01-01

103

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

Science.gov (United States)

An optical model of classical photons propagating through array of many beam splitters is developed to give a physical analogy of Parrondo's game and Parrondo-Harmer-Abbott game. We showed both the two games are reasonable game without so-called game paradox and they are essentially the same. We designed the games with long-term memory on loop lattice and history-entangled game. The strong correlation between nearest two rounds of game can make the combination of two losing game win, lose or oscillate between win and loss. The periodic potential in Brownian ratchet is analogous to a long chain of beam splitters. The coupling between two neighboring potential wells is equivalent to two coupled beam splitters. This correspondence may help us to understand the anomalous motion of exceptional Brownian particles moving in the opposite direction to the majority. We designed the capital wave for a game by introducing correlations into independent capitals instead of sub-games. Playing entangled quantum states in many coupled classical games obey the same rules for manipulating quantum states in many body physics.

Si, Tieyan

2012-11-01

104

Norepinephrine enhances a discrete form of long-term depression during fear memory storage.  

UK PubMed Central (United Kingdom)

Amygdala excitatory synaptic strengthening is thought to contribute to both conditioned fear and anxiety. Thus, one basis for behavioral flexibility could allow these pathways to be weakened and corresponding emotion to be attenuated. However, synaptic depression within the context of amygdala-dependent behavior remains poorly understood. Previous work identified lateral amygdala (LA) calcium-permeable AMPA receptors (CP-AMPARs) as a key target for synaptic removal in long-term depression (LTD) and persistent fear attenuation. Here we demonstrate that LA neurons express two equally potent forms of LTD with contrasting requirements for protein kinase and phosphatase activity and differential impact on CP-AMPAR trafficking. Selective removal of CP-AMPARs from synapses is contingent on group 1 metabotropic glutamate receptor (mGluR1) and PKC signaling, in contrast to an alternate LTD pathway that nonselectively removes AMPARs and requires calcineurin (PP2b). Intriguingly, the balance between these forms of LTD is shifted by posttraining activation of ?-adrenergic receptors in fear conditioned mice, resulting in selective augmentation of mGluR-dependent depression. These results highlight the complexity of core mechanisms in LTD and suggest that norepinephrine exposure mediates a form of synaptic metaplasticity that recalibrates fear memory processing.

Clem RL; Huganir RL

2013-07-01

105

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

Directory of Open Access Journals (Sweden)

Full Text Available Introduction:The hippocampus is one for the major centers of learning and memory. Role of the opioid system has been investigated and on the other hand receptors related to this system such as mu-opioid receptors (MOR) are extended in the hippocampus. In this study the effect of Naloxone administration as a mu opioid receptor antagonist on passive avoidance memory in adult male rats was investigated by using shuttle box instrument. Methods:Methods: In this study 45 male adult Wistar rats at range of 200± 20 were used. They were cannulated after anesthesia and Naloxone 0.5, 1, 1.5 and 2 µg/rat has been injected intrahippocampally after recovery and post training by shuttle box .Then after 90 minute short –term memory and after 24 hours long- term memory were measured posttrainingly. Results:results showed that naloxone0.5, 1, 1.5 and 2µg/rat didn’t affected short – term memory on the other hand according to results of long-term memory showed that Naloxone 0.5 µg/rat didn’t affected memory and Naloxone 1 and 1.5 µg/rat improved memory and Naloxone 2 µg/rat impaired memory. Conclusion:Considering to obtained results it seems that Naloxone affected learning and memory in a dose dependent manner.

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

2012-01-01

106

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

UK PubMed Central (United Kingdom)

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

Wang DM; Yang YJ; Zhang L; Zhang X; Guan FF; Zhang LF

2013-01-01

107

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

Science.gov (United States)

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

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

2013-03-11

108

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

Science.gov (United States)

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

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

2012-01-01

109

PKA and PKC are required for long-term but not short-term in vivo operant memory in Aplysia  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We investigated the involvement of PKA and PKC signaling in a negatively reinforced operant learning paradigm in Aplysia, learning that food is inedible (LFI). In vivo injection of PKA or PKC inhibitors blocked long-term LFI memory formation. Moreover, a persistent phase of PKA activity, although no...

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

110

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

DEFF Research Database (Denmark)

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

Guerrieri, Fernando Javier; D'Ettorre, Patrizia

2011-01-01

111

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

International Nuclear Information System (INIS)

To see the dose dependent effects of zinc chloride on the short-term and long-term memory in a shuttle box (rats). Six pair adult wistar rats were taken for this experiment. One group of pregnant rats received a daily oral dose of 20 mg/kg Zn as zinc chloride and the remaining groups received a daily oral dose of (30, 50, 70,100 mg/kg) zinc chloride for two weeks by gavage. One month after birth, a shuttle box was used to test short-term and long-term memory. Two criteria were considered to behavioral test, including latency in entering dark chamber and time spent in the dark chamber. This experiment showed that oral administration of ZnCl/sub 2/ with (20, 30, 50 mg/kg/day) doses after 2 weeks at the stage of pregnancy, can improve the working memory of their offspring (p

2007-01-01

112

Relation between school bullying during adolescence and subsequent long-term unemployment in adulthood in a Finnish sample.  

UK PubMed Central (United Kingdom)

The relationship between school bullying in adolescence and long-term unemployment in adulthood was investigated. A questionnaire was distributed to 68 participants of a training program for people with long-term unemployment in Finland. Responses were compared with data of a nationwide investigation (sample 53,394) of the prevalence of school bullying, according to which 8% of Finnish pupils are regularly bullied at least once a week. Among people with long-term unemployment, 29% reported having been exposed to school bullying at least once a week during their adolescence. This finding indicates a relationship between self-reported school bullying in adolescence and long-term unemployment in adulthood.

Varhama LM; Björkqvist K

2005-04-01

113

Pre-learning stress that is temporally removed from acquisition exerts sex-specific effects on long-term memory.  

UK PubMed Central (United Kingdom)

We have examined the influence of sex and the perceived emotional nature of learned information on pre-learning stress-induced alterations of long-term memory. Participants submerged their dominant hand in ice cold (stress) or warm (no stress) water for 3 min. Thirty minutes later, they studied 30 words, rated the words for their levels of emotional valence and arousal and were then given an immediate free recall test. Twenty-four hours later, participants' memory for the word list was assessed via delayed free recall and recognition assessments. The resulting memory data were analyzed after categorizing the studied words (i.e., distributing them to "positive-arousing", "positive-non-arousing", "negative-arousing", etc. categories) according to participants' valence and arousal ratings of the words. The results revealed that participants exhibiting a robust cortisol response to stress exhibited significantly impaired recognition memory for neutral words. More interestingly, however, males displaying a robust cortisol response to stress demonstrated significantly impaired recall, overall, and a marginally significant impairment of overall recognition memory, while females exhibiting a blunted cortisol response to stress demonstrated a marginally significant impairment of overall recognition memory. These findings support the notion that a brief stressor that is temporally separated from learning can exert deleterious effects on long-term memory. However, they also suggest that such effects depend on the sex of the organism, the emotional salience of the learned information and the degree to which stress increases corticosteroid levels.

Zoladz PR; Warnecke AJ; Woelke SA; Burke HM; Frigo RM; Pisansky JM; Lyle SM; Talbot JN

2013-02-01

114

Cost analysis of automated long-term sampling in comparison to existing application modes of manual short-term sampling  

Energy Technology Data Exchange (ETDEWEB)

Because of the unsatisfactory informations which are given by manual sampling, some plants are controlled more frequently by manual sampling, by demand of the local authorities. Such more frequently manual samplings lead to an intensive cost increase of the dioxin emission control. As reported in earlier publications, the ROCEPA (Republic if China EPA) was setting up a project for continuous monitoring of PCDD/F. One topic of this project, which is surely also of general international interest, was a cost analysis for the comparison of long-term sampling and different application modes of manual sampling, which are applied practice in Taiwan in different plants. For the project, the long-term sampling system AMESA {sup registered} was chosen and therefore the published results are calculated on the basis of the AMESA {sup registered} system price. Additional other calculations show that also for dioxin inventories in European countries, the costs by using a long-term sampling system would be in an acceptable cost efficient range.

Reinmann, J. [bm becker messtechnik gmbh, Eschborn (Germany); Huang, A. [TUeV Rheinland Taiwan Ltd., Taipeh (Taiwan); Mehl, K.W.

2004-09-15

115

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

Science.gov (United States)

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

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

2006-01-01

116

Olfactory associative discrimination: a model for studying modifications of synaptic efficacy in neuronal networks supporting long-term memory.  

Science.gov (United States)

This review summarizes research that correlates behavioral performance and cellular physiology leading to modifications in the neuronal networks supporting long-term memory in the mammalian brain. Rats were trained in an olfactory associative discrimination task in which natural odors were replaced by mimetic olfactory stimulations. Olfactory learning induced synaptic modifications that affected behavioral performance along the central olfactory pathways. Starting with an early increase in monosynaptic efficacy in the dentate gyrus on the first session, a polysynaptic modification appeared later on in this hippocampal network, when rats began to make associations between cues and rewards. Therefore, only when rats made consistent associations did a long-term potentiation in the synapses of the piriform cortex pyramidal neurons appear. These modifications may correspond to the long-term storage of the meaning of the cue-reward association in a specific cortical area. Based on these cumulative results, a hypothesis is proposed to account for how, when, and where synaptic modifications in neural networks are required to constitute long-term memory. PMID:15046196

Roman, François S; Truchet, Bruno; Chaillan, Franck A; Marchetti, Evelyne; Soumireu-Mourat, Bernard

2004-01-01

117

Immunosuppressive effect of long-term drainage of thoracic duct on immunological memory in adult thymectomized rats.  

UK PubMed Central (United Kingdom)

Profound reduction of the recirculating lymphocyte pool using thoracic duct drainage (TDD), a method developed by Gowans et al, has been shown to be of limited immunosuppressive value when applied in experimental as well as in clinical settings across major histocompatibility antigen complex (MHC) differences. This limitation is due to the observation that animals, in particular mice, are normally not able to have the drainage last longer than 8 to 10 days. However, using a simple modification of TDD, we have established a long-term TDD method, ie, more than 20 days. Combining this long-term TDD with adult thymectomy, we have examined the life span of naive and memory T cells specific for the minor histocompatibility antigen H-Y in female lewis rats. Furthermore, we demonstrated that memory T cells specific for the H-Y antigen do not appear to be recirculating lymphocytes.

Satoh E; Hattori Y; Guo L; Li XK; Teramoto K; Arii S; Kimura H

2005-05-01

118

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

Directory of Open Access Journals (Sweden)

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

Fei-xue HUANG; Jian-dong JIN; Yan-xi LI

2010-01-01

119

Sampling the soil in long-term forest plots: the implications of spatial variation.  

Science.gov (United States)

Long-term monitoring of forest soils as part of a pan-European network to detect environmental change depends on an accurate determination of the mean of the soil properties at each monitoring event. Forest soil is known to be very variable spatially, however. A study was undertaken to explore and quantify this variability at three forest monitoring plots in Britain. Detailed soil sampling was carried out, and the data from the chemical analyses were analysed by classical statistics and geostatistics. An analysis of variance showed that there were no consistent effects from the sample sites in relation to the position of the trees. The variogram analysis showed that there was spatial dependence at each site for several variables and some varied in an apparently periodic way. An optimal sampling analysis based on the multivariate variogram for each site suggested that a bulked sample from 36 cores would reduce error to an acceptable level. Future sampling should be designed so that it neither targets nor avoids trees and disturbed ground. This can be achieved best by using a stratified random sampling design. PMID:16311827

Kirwan, N; Oliver, M A; Moffat, A J; Morgan, G W

2005-12-01

120

Sampling the soil in long-term forest plots: the implications of spatial variation.  

UK PubMed Central (United Kingdom)

Long-term monitoring of forest soils as part of a pan-European network to detect environmental change depends on an accurate determination of the mean of the soil properties at each monitoring event. Forest soil is known to be very variable spatially, however. A study was undertaken to explore and quantify this variability at three forest monitoring plots in Britain. Detailed soil sampling was carried out, and the data from the chemical analyses were analysed by classical statistics and geostatistics. An analysis of variance showed that there were no consistent effects from the sample sites in relation to the position of the trees. The variogram analysis showed that there was spatial dependence at each site for several variables and some varied in an apparently periodic way. An optimal sampling analysis based on the multivariate variogram for each site suggested that a bulked sample from 36 cores would reduce error to an acceptable level. Future sampling should be designed so that it neither targets nor avoids trees and disturbed ground. This can be achieved best by using a stratified random sampling design.

Kirwan N; Oliver MA; Moffat AJ; Morgan GW

2005-12-01

 
 
 
 
121

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.  

UK PubMed Central (United Kingdom)

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.

Charlton BG; Andras P

2009-07-01

122

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)

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

Charlton, Bruce G; Andras, Peter

2009-04-05

123

The effects of word co-occurrence on short-term memory: associative links in long-term memory affect short-term memory performance.  

Science.gov (United States)

In immediate serial recall tasks, high-frequency words are recalled better than low-frequency words. This has been attributed to high-frequency words' being better represented and providing more effective support to a redintegration process at retrieval (C. Hulme et al., 1997). In studies of free recall, there is evidence that frequency of word co-occurrence, rather than word frequency per se, may explain the recall advantage enjoyed by high-frequency words (J. Deese, 1960). The authors present evidence that preexposing pairs of low-frequency words, so as to create associative links between them, has substantial beneficial effects on immediate serial recall performance. These benefits, which are not attributable to simple familiarization with the words per se, do not occur for high-frequency words. These findings indicate that associative links between items in long-term memory have important effects on short-term memory performance and suggest that the effects of word frequency in short-term memory tasks are related to differences in interitem associations in long-term memory. PMID:10855432

Stuart, G; Hulme, C

2000-05-01

124

The effects of word co-occurrence on short-term memory: associative links in long-term memory affect short-term memory performance.  

UK PubMed Central (United Kingdom)

In immediate serial recall tasks, high-frequency words are recalled better than low-frequency words. This has been attributed to high-frequency words' being better represented and providing more effective support to a redintegration process at retrieval (C. Hulme et al., 1997). In studies of free recall, there is evidence that frequency of word co-occurrence, rather than word frequency per se, may explain the recall advantage enjoyed by high-frequency words (J. Deese, 1960). The authors present evidence that preexposing pairs of low-frequency words, so as to create associative links between them, has substantial beneficial effects on immediate serial recall performance. These benefits, which are not attributable to simple familiarization with the words per se, do not occur for high-frequency words. These findings indicate that associative links between items in long-term memory have important effects on short-term memory performance and suggest that the effects of word frequency in short-term memory tasks are related to differences in interitem associations in long-term memory.

Stuart G; Hulme C

2000-05-01

125

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

Directory of Open Access Journals (Sweden)

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

Mark Hughes

2004-01-01

126

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

UK PubMed Central (United Kingdom)

Glucocorticoid hormones enhance the consolidation of long-term memory of emotionally arousing training experiences. This memory enhancement requires activation of the cAMP-dependent kinase pathway and the subsequent phosphorylation of cAMP response-element binding (CREB) protein. Here, we demonstrate that glucocorticoids enhance the consolidation of hippocampus-dependent and hippocampus-independent aspects of object recognition memory via chromatin modification. More specifically, systemic corticosterone increases histone acetylation, a form of chromatin modification, in both the hippocampus and insular cortex following training on an object recognition task. This led us to examine whether increasing histone acetylation via histone deacetylase (HDAC) inhibition enhances memory in a manner similar to corticosterone. We found a double dissociation between posttraining HDAC inhibitor infusion into the insular cortex and hippocampus on the enhancement of object recognition and object location memory, respectively. In determining the molecular pathway upstream of glucocorticoids' effects on chromatin modification, we found that activation of membrane-associated glucocorticoid receptors (GRs) and the subsequent interaction between phospho-CREB and CREB-binding protein (CBP) appear to be necessary for glucocorticoids to enhance memory consolidation via chromatin modification. In contrast, mineralocorticoid receptors (MRs) do not appear to be involved. The findings also indicate that glucocorticoid activity has differential influences on hippocampus-dependent and hippocampus-independent components of memory for objects.

Roozendaal B; Hernandez A; Cabrera SM; Hagewoud R; Malvaez M; Stefanko DP; Haettig J; Wood MA

2010-04-01

127

An automated training paradigm reveals long-term memory in planaria and its persistence through head regeneration.  

UK PubMed Central (United Kingdom)

Planarian flatworms are a popular system for research into the molecular mechanisms that enable these complex organisms to regenerate their entire body, including the brain. Classical data suggest that they may also be capable of long-term memory. Thus, the planarian system may offer the unique opportunity to study brain regeneration and memory in the same animal. To establish a system for the investigation of the dynamics of memory in a regenerating brain, we developed a computerized training and testing paradigm that avoided the many issues that confounded previous, manual attempts to train planaria. We then used this new system to train flatworms in an environmental familiarization protocol. We show that worms exhibit environmental familiarization, and that this memory persists for at least 14 days - long enough for the brain to regenerate. We further show that trained, decapitated planaria exhibit evidence of memory retrieval in a savings paradigm after regenerating a new head. Our work establishes a foundation for objective, high-throughput assays in this molecularly-tractable model system that will shed light on the fundamental interface between body patterning and stored memories. We propose planaria as a key emerging model species for mechanistic investigations of the encoding of specific memories in biological tissues. Moreover, this system is likely to have important implications for the biomedicine of stem cell-derived treatments of degenerative brain disorders in human adults.

Shomrat T; Levin M

2013-07-01

128

An automated training paradigm reveals long-term memory in planarians and its persistence through head regeneration.  

UK PubMed Central (United Kingdom)

Planarian flatworms are a popular system for research into the molecular mechanisms that enable these complex organisms to regenerate their entire body, including the brain. Classical data suggest that they may also be capable of long-term memory. Thus, the planarian system may offer the unique opportunity to study brain regeneration and memory in the same animal. To establish a system for the investigation of the dynamics of memory in a regenerating brain, we developed a computerized training and testing paradigm that avoided the many issues that confounded previous, manual attempts to train planarians. We then used this new system to train flatworms in an environmental familiarization protocol. We show that worms exhibit environmental familiarization, and that this memory persists for at least 14 days - long enough for the brain to regenerate. We further show that trained, decapitated planarians exhibit evidence of memory retrieval in a savings paradigm after regenerating a new head. Our work establishes a foundation for objective, high-throughput assays in this molecularly tractable model system that will shed light on the fundamental interface between body patterning and stored memories. We propose planarians as key emerging model species for mechanistic investigations of the encoding of specific memories in biological tissues. Moreover, this system is lik ely to have important implications for the biomedicine of stem-cell-derived treatments of degenerative brain disorders in human adults.

Shomrat T; Levin M

2013-10-01

129

An automated training paradigm reveals long-term memory in planarians and its persistence through head regeneration.  

Science.gov (United States)

Planarian flatworms are a popular system for research into the molecular mechanisms that enable these complex organisms to regenerate their entire body, including the brain. Classical data suggest that they may also be capable of long-term memory. Thus, the planarian system may offer the unique opportunity to study brain regeneration and memory in the same animal. To establish a system for the investigation of the dynamics of memory in a regenerating brain, we developed a computerized training and testing paradigm that avoided the many issues that confounded previous, manual attempts to train planarians. We then used this new system to train flatworms in an environmental familiarization protocol. We show that worms exhibit environmental familiarization, and that this memory persists for at least 14 days - long enough for the brain to regenerate. We further show that trained, decapitated planarians exhibit evidence of memory retrieval in a savings paradigm after regenerating a new head. Our work establishes a foundation for objective, high-throughput assays in this molecularly tractable model system that will shed light on the fundamental interface between body patterning and stored memories. We propose planarians as key emerging model species for mechanistic investigations of the encoding of specific memories in biological tissues. Moreover, this system is lik ely to have important implications for the biomedicine of stem-cell-derived treatments of degenerative brain disorders in human adults. PMID:23821717

Shomrat, Tal; Levin, Michael

2013-07-02

130

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

UK PubMed Central (United Kingdom)

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.

Harand C; Bertran F; La Joie R; Landeau B; Mézenge F; Desgranges B; Peigneux P; Eustache F; Rauchs G

2012-01-01

131

Relation between school bullying during adolescence and subsequent long-term unemployment in adulthood in a Finnish sample.  

Science.gov (United States)

The relationship between school bullying in adolescence and long-term unemployment in adulthood was investigated. A questionnaire was distributed to 68 participants of a training program for people with long-term unemployment in Finland. Responses were compared with data of a nationwide investigation (sample 53,394) of the prevalence of school bullying, according to which 8% of Finnish pupils are regularly bullied at least once a week. Among people with long-term unemployment, 29% reported having been exposed to school bullying at least once a week during their adolescence. This finding indicates a relationship between self-reported school bullying in adolescence and long-term unemployment in adulthood. PMID:15941099

Varhama, Lasse M; Björkqvist, Kaj

2005-04-01

132

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

UK PubMed Central (United Kingdom)

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), Exercise (Ex) and Stress and Exercise (St & Ex) groups. Chronic restraint stress was applied by 6h/day/21days and also treadmill running at a speed 20-21m/min for 1h/day/21days. Memory function was evaluated by the passive avoidance test in different intervals (1, 7 and 21 days) after foot shock. RESULTS: OUR RESULTS SHOWED THAT: 1) Although exercise alone showed beneficial effects especially on short and mid-term memory (P<0.05) in comparison with control group, but synchronized exercise with stress had not significantly improved short, mid and long-term memory deficit in stressed rats. 2) Short and mid-term memory deficit was significantly (P<0.05) observed in synchronized exercise with stress and stress groups with respect to normal rats. 3) Memory deficit in synchronized exercise with stress group was nearly similar to stressed rats. 4) Helpful effects of exercise were less than harmful effects of stress when they were associated together. CONCLUSION: The data correspond to the possibility that although treadmill running alone has helpful effects on learning and memory consolidation, but when it is synchronized with stress there is no significant benefit and protective effects in improvement of memory deficit induced by chronic stress. However, it is has a better effect than no training on memory deficit in stressed rats.

Radahmadi M; Alaei H; Sharifi MR; Hosseini N

2013-03-01

133

Mind bomb-1 is an essential modulator of long-term memory and synaptic plasticity via the Notch signaling pathway  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Notch signaling is well recognized as a key regulator of the neuronal fate during embryonic development, but its function in the adult brain is still largely unknown. Mind bomb-1 (Mib1) is an essential positive regulator in the Notch pathway, acting non-autonomously in the signal-sending cells. Therefore, genetic ablation of Mib1 in mature neuron would give valuable insight to understand the cell-to-cell interaction between neurons via Notch signaling for their proper function. Results Here we show that the inactivation of Mib1 in mature neurons in forebrain results in impaired hippocampal dependent spatial memory and contextual fear memory. Consistently, hippocampal slices from Mib1-deficient mice show impaired late-phase, but not early-phase, long-term potentiation and long-term depression without change in basal synaptic transmission at SC-CA1 synapses. Conclusions These data suggest that Mib1-mediated Notch signaling is essential for long-lasting synaptic plasticity and memory formation in the rodent hippocampus.

Yoon Ki-Jun; Lee Hye-Ryeon; Jo Yong Sang; An Kyongman; Jung Sang-Yong; Jeong Min-Woo; Kwon Seok-Kyu; Kim Nam-Shik; Jeong Hyun-Woo; Ahn Seo-Hee; Kim Kyong-Tai; Lee Kyungmin; Kim Eunjoon; Kim Joung-Hun; Choi June-Seek; Kaang Bong-Kiun; Kong Young-Yun

2012-01-01

134

Long-term benefits of the Memory-Link programme in a case of amnesia.  

UK PubMed Central (United Kingdom)

OBJECTIVE: To systematically evaluate the maintenance of clinical gains from a structured memory intervention programme. Efficacy of the programme was initially demonstrated in RR, a woman with moderate-to-severe memory impairment following colloid cyst removal. In the current study (Svoboda and Richards, 2009), we examined RR's day-to-day memory functioning 18 months after completion of the intervention programme. DESIGN: Within-subject A(1)B(1)A(2)B(2)B(3) single-case experimental design. SETTING: Outpatient memory rehabilitation clinic. INTERVENTION: A theory-driven training programme in the use of commercially available smartphones for individuals with moderate-to-severe memory impairment. MAIN MEASURES: A phone call task was used as an objective measure of prospective memory function. Self-report, ecologically valid questionnaires were also completed to further assess generalization of smartphone use to day-to-day memory function. RESULTS: Eighteen months after intervention, RR completed 80% of scheduled calls using the smartphone, a rate significantly higher than at baseline (40%) and comparable to her success rate immediately following intervention (90%) and at the four-month follow-up (90%). Responses to questionnaires indicated that RR felt more confident in her ability to handle memory-demanding situations and was making fewer memory mistakes. This favourable outcome was not found with the use of another smartphone brand for which training was not received. CONCLUSIONS: Results from ecologically valid measures of memory functioning demonstrated robust maintenance of independent commercial smartphone use over an 18-month period, with increases observed in independence, confidence and real-life memory functioning. The findings further suggest poor cross-device generalizability.

Savage KR; Svoboda E

2013-06-01

135

Long-term calibration considerations during subcutaneous microdialysis sampling in mobile rats.  

UK PubMed Central (United Kingdom)

The level at which implanted sensors and sampling devices maintain their calibration is an important research area. In this work, microdialysis probes with identical geometry and different membranes, polycarbonate/polyether (PC) or polyethersulfone (PES), were used with internal standards (Vitamin B(12) (MW 1355), antipyrine (MW 188) and 2-deoxyglucose (2-DG, MW 164)) and endogenous glucose to investigate changes in their long-term calibration after implantation into the subcutaneous space of Sprague-Dawley rats. Histological analysis confirmed an inflammatory response to the microdialysis probes and the presence of a collagen capsule. The membrane extraction efficiency (percentage delivered to the tissue space) for antipyrine and 2-DG was not altered throughout the implant lifetime for either PC- or PES membranes. Yet, Vitamin B(12) extraction efficiency and collected glucose concentrations decreased during the implant lifetime. Antipyrine was administered i.v. and its concentrations obtained in both PC- and PES-membrane probes were significantly reduced between the implant day and seven (PC) or 10 (PES) days post-implantation suggesting that solute supply is critical for in vivo extraction efficiency. For the low molecular weight solutes such as antipyrine and glucose, localized delivery is not affected by the foreign body reaction, but recovery is significantly reduced. For Vitamin B(12), a larger solute, the fibrotic capsule formed around the probe significantly restricts diffusion from the implanted microdialysis probes.

Mou X; Lennartz MR; Loegering DJ; Stenken JA

2010-06-01

136

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

International Nuclear Information System (INIS)

[en] 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

1990-01-01

137

Long-term outcomes of cochlear implantation in early childhood: sample characteristics and data collection methods.  

UK PubMed Central (United Kingdom)

OBJECTIVES: This article describes participants in a follow-up study of a nationwide sample of children who had used a cochlear implant (CI) since preschool. The children were originally tested when they were in early elementary grades, and results were published in a monograph supplement of Ear and Hearing. Recently, many of these children returned for follow-up testing when they were in high school with >10 yrs experience with a CI. This introductory article will (1) discuss the extent to which the sample tested is representative of typical populations and (2) describe how sample characteristics changed over time for the 112 students tested in both elementary grades and high school. DESIGN: Over a 4-yr period, 112 teenagers from across North America, accompanied by a parent, attended a research camp that was similar to one in which they had participated 8 yrs earlier. A battery of auditory, speech, language, and reading tests was administered, and responses to questionnaires and written language samples were obtained and are described in the following articles in this issue. This article summarizes child, family, and educational characteristics that were quantified so that their role in outcome levels achieved could be examined statistically. For example, metrics were devised to reflect the extent to which a student's language improved when sign language was added to spoken language (i.e., sign enhancement) based on test results obtained in elementary grades and in high school. RESULTS: Comparisons of early characteristics of the 112 students who returned for follow-up testing with the 72 who did not return indicated comparable Performance Intelligence Quotients, communication mode ratings, family education/income, and age at implant. However, follow-up participants had better speech perception, speech intelligibility, and language skills at 8 or 9 yrs of age. Seventy-five percent of returning teenagers were fully mainstreamed in high school (compared with 63% in elementary grades). Only 5% of adolescents were in full-time special education. Grade placement of the teenagers was appropriate to their chronologic age. Estimates of sign enhancement, family characteristics, and Performance Intelligence Quotient were consistent over the two test sessions. CONCLUSIONS: A large proportion of the original sample returned for follow-up testing in adolescence, but they were a more selective group than nonreturning subjects, and their scores may overestimate long-term CI outcomes for the general population. On the other hand, CI-HS students who participated in this study received their device >10 yrs ago and did not have some of the advantages available to more recently implanted children, so their results may underestimate those outcomes.

Geers AE; Brenner CA; Tobey EA

2011-02-01

138

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

Directory of Open Access Journals (Sweden)

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

H. Maldonado; A. Romano; D. Tomsic

1997-01-01

139

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in english A decade of studies on long-term habituation (LTH) in the crab Chasmagnathus is reviewed. Upon sudden presentation of a passing object overhead, the crab reacts with an escape response that habituates promptly and for at least five days. LTH proved to be an instance of associative memory and showed context, stimulus frequency and circadian phase specificity. A strong training protocol (STP) (³15 trials, intertrial interval (ITI) of 171 s) invar (more) iably 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

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

1997-07-01

140

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

UK PubMed Central (United Kingdom)

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

Gupta R; Gupta LK

2012-08-01

 
 
 
 
141

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.

2012-01-01

142

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

UK PubMed Central (United Kingdom)

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.

Quas JA; Goodman GS; Bidrose S; Pipe ME; Craw S; Ablin DS

1999-04-01

143

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

Science.gov (United States)

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

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

2013-08-01

144

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

Science.gov (United States)

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

Amano, Hisayuki; Maruyama, Ichiro N.

2011-01-01

145

Mental health outcome of long-term and episodic adolescent depression: 15-year follow-up of a community sample.  

UK PubMed Central (United Kingdom)

BACKGROUND: Recent studies have highlighted the unfavourable natural course of chronic/long-term depression. We investigated the adult mental health outcome of adolescent depression, with specific focus on long-term and episodic adolescent major depression (MD). METHODS: A community sample of depressed adolescents and non-depressed peers was followed-up with a structured diagnostic interview after 15 years. The participants (n=382) were divided into five groups depending on their status in adolescence: no depression (n=155); long-term MD (n=91); episodic MD (n=63); dysthymia (n=33); and subthreshold symptoms (n=40). Outcomes (age 19-31) included mood disorders, other mental disorders, suicidality, and treatment for mental disorders. RESULTS: The long-term group overall had a poorer outcome than the non-depressed group, with the episodic group in an intermediate position. The outcome of the dysthymic group was similar to that of the long-term group, while the subsyndromal group did not differ markedly from the non-depressed group. The long-term group was more likely than the episodic group to report adult anxiety disorders, multiple mental disorders, suicide attempts, and treatment; they also seemed to develop more persistent adult depressions, with a higher number of recurrent episodes and longer duration of antidepressant treatment. Even after adjustment for adolescent factors of clinical and etiological importance, the long-term group had a markedly less favourable outcome than the episodic group. LIMITATION: The participation rate at follow-up was 64.6%. CONCLUSION: Longstanding depression in adolescence is a powerful predictor of continued mental health problems in adulthood. It is now important to evaluate if early interventions can alter this severe course.

Jonsson U; Bohman H; von Knorring L; Olsson G; Paaren A; von Knorring AL

2011-05-01

146

A transcription factor-binding domain of the coactivator CBP is essential for long-term memory and the expression of specific target genes.  

UK PubMed Central (United Kingdom)

Transcriptional activation is a key process required for long-term memory formation. Recently, the transcriptional coactivator CREB-binding protein (CBP) was shown to be critical for hippocampus-dependent long-term memory and hippocampal synaptic plasticity. As a coactivator with intrinsic histone acetyltransferase activity, CBP interacts with numerous transcription factors and contains multiple functional domains. Currently, it is not known which transcription factor-binding domain of CBP is essential for memory storage. Using mice that carry inactivating mutations in the CREB-binding (KIX) domain of the coactivator CBP (CBPKIX/KIX mice), we show that the KIX domain is required for long-term memory storage. These results are the first to identify an in vivo function for the KIX domain of CBP in the brain, and they suggest that KIX-interacting transcription factors recruit CBP histone acetyltransferase activity during long-term memory storage. One such KIX-interacting factor is the transcription factor CREB. Using quantitative real-time RT-PCR, we find that the expression of specific CREB target genes is reduced in the hippocampi of CBPKIX/KIX mice during memory consolidation. The recruitment of the transcriptional coactivator CBP via the KIX domain thus imparts target gene-dependent selectivity to CREB-driven transcriptional regulation, thereby activating genes required for the long-term storage of hippocampus-dependent memory.

Wood MA; Attner MA; Oliveira AM; Brindle PK; Abel T

2006-09-01

147

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

UK PubMed Central (United Kingdom)

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

Conejo NM; Cimadevilla JM; González-Pardo H; Méndez-Couz M; Arias JL

2013-01-01

148

Repolarization Changes Underlying Long-Term Cardiac Memory Due to Right Ventricular Pacing: Noninvasive Mapping with ECGI  

Science.gov (United States)

Background Cardiac memory refers to the observation that altered cardiac electrical activation results in repolarization changes that persist after the restoration of a normal activation pattern. Animal studies, however, have yielded disparate conclusions both regarding the spatial pattern of repolarization changes in cardiac memory and the underlying mechanisms. This study was undertaken to produce three dimensional images of the repolarization changes underlying long-term cardiac memory in humans. Methods and Results Nine adult subjects with structurally normal hearts and dual-chamber pacemakers were enrolled in the study. Non-invasive electrocardiographic imaging (ECGI) was used before and after one month of ventricular pacing to reconstruct epicardial activation and repolarization patterns. Eight subjects exhibited cardiac memory in response to ventricular pacing. In all subjects, ventricular pacing resulted in a prolongation of the activation recovery interval (a surrogate for action potential duration) in the region close to the site of pacemaker-induced activation from 228.4±7.6 ms during sinus rhythm to 328.3±6.2 ms during cardiac memory. As a consequence, increases are observed in both apical-basal and right-left ventricular gradients of repolarization resulting in a significant increase in the dispersion of repolarization. Conclusions These results demonstrate that electrical remodeling in response to ventricular pacing in human subjects results in action potential prolongation near the site of abnormal activation and a marked dispersion of repolarization. This dispersion of repolarization is potentially arrhythmogenic and, intriguingly, was less evident during continuous RV pacing, suggesting the novel possibility that continuous RV pacing at least partially suppresses pacemaker-induced cardiac memory.

Marrus, Scott B.; Andrews, Christopher M.; Cooper, Daniel H.; Faddis, Mitchell N.; Rudy, Yoram

2012-01-01

149

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)

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.

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

2008-01-01

150

Dissociation of explicit and implicit long-term memory consolidation in semantic dementia: a case study.  

UK PubMed Central (United Kingdom)

We report a case study of a semantic dementia patient, whose episodic memory consolidation was tested over a 2-month period. The results reveal that despite early retention of information, the patient lost all explicit information of the newly learnt material after 2 weeks. By contrast, he retained implicit word information even after a 4-week delay. These findings highlight the critical time window of 2-4 weeks in which newly learnt information should be re-encoded in rehabilitations studies. The results also indicate that learnt information can be still accessed with implicit retrieval strategies when explicit retrieval fails.

Tu S; Mioshi E; Savage S; Hodges JR; Hornberger M

2013-08-01

151

Characterization of long-term memory, resistance to extinction, and influence of temperament during two instrumental tasks in horses.  

UK PubMed Central (United Kingdom)

The present study investigated the influence of temperament on long-term recall and extinction of 2 instrumental tasks in 26 horses. In the first task (backward task), horses learned to walk backward, using commands given by an experimenter, in order to obtain a food reward. In the second task (active avoidance task), horses had to cross an obstacle after a bell rang in order to avoid emission of an air puff. Twenty-two months after acquisition, horses exhibited perfect recall performance in both tasks. Accordingly, no influence of temperament on recall performance could be observed for either task. In contrast, in the absence of positive or negative outcomes, the horses' ability to extinguish their response to either task was highly variable. Resistance to extinction was related to some indicators of temperament: The most fearful horses tended to be the most resistant to extinction in the backward task, while the least sensitive horses tended to be the most resistant to extinction in the active avoidance task. These findings reveal extensive long-term memory abilities in horses and suggest an influence of temperament on learning processes other than acquisition.

Valenchon M; Lévy F; Górecka-Bruzda A; Calandreau L; Lansade L

2013-06-01

152

Characterization of long-term memory, resistance to extinction, and influence of temperament during two instrumental tasks in horses.  

UK PubMed Central (United Kingdom)

The present study investigated the influence of temperament on long-term recall and extinction of 2 instrumental tasks in 26 horses. In the first task (backward task), horses learned to walk backward, using commands given by an experimenter, in order to obtain a food reward. In the second task (active avoidance task), horses had to cross an obstacle after a bell rang in order to avoid emission of an air puff. Twenty-two months after acquisition, horses exhibited perfect recall performance in both tasks. Accordingly, no influence of temperament on recall performance could be observed for either task. In contrast, in the absence of positive or negative outcomes, the horses' ability to extinguish their response to either task was highly variable. Resistance to extinction was related to some indicators of temperament: The most fearful horses tended to be the most resistant to extinction in the backward task, while the least sensitive horses tended to be the most resistant to extinction in the active avoidance task. These findings reveal extensive long-term memory abilities in horses and suggest an influence of temperament on learning processes other than acquisition.

Valenchon M; Lévy F; Górecka-Bruzda A; Calandreau L; Lansade L

2013-11-01

153

Memorization and recall of very long lists accounted for within the Long-Term Working Memory framework.  

UK PubMed Central (United Kingdom)

In a recent paper, Hu, Ericsson, Yang, and Lu (2009) found that an ability to memorize very long lists of digits is not mediated by the same mechanisms as exceptional memory for rapidly presented lists, which has been the traditional focus of laboratory research. Chao Lu is the holder of the Guinness World Record for reciting the most decimal positions of pi, yet he lacks an exceptional memory span for digits. In the first part of this paper we analyzed the reliability and structure of his reported encodings for lists of 300 digits and his application of the story mnemonic. Next, his study and recall times for lists of digits were analyzed to test hypotheses about his detailed encoding processes, and cued-recall performance was used to assess the structure of his encodings. Three experiments were then designed to interfere with the uniqueness of Chao Lu's story encodings, and evidence was found for his remarkable ability to adapt his encoding processes to reduce the interference. Finally, we show how his skills for encoding and recalling long lists can be accounted for within the theoretical framework of Ericsson and Kintsch's (1995) Long-Term Working Memory.

Hu Y; Ericsson KA

2012-06-01

154

Calcium-stimulated adenylyl cyclase activity is critical for hippocampus-dependent long-term memory and late phase LTP.  

Science.gov (United States)

It is hypothesized that Ca2+ stimulation of calmodulin (CaM)-activated adenylyl cyclases (AC1 or AC8) generates cAMP signals critical for late phase LTP (L-LTP) and long-term memory (LTM). However, mice lacking either AC1 or AC8 exhibit normal L-LTP and LTM. Here, we report that mice lacking both enzymes (DKO) do not exhibit L-LTP or LTM. To determine if these defects are due to a loss of cAMP increases in the hippocampus, DKO mice were unilaterally cannulated to deliver forskolin. Administration of forskolin to area CA1 before training restored normal LTM. We conclude that Ca2+-stimulated adenylyl cyclase activity is essential for L-LTP and LTM and that AC1 or AC8 can produce the necessary cAMP signal. PMID:10482244

Wong, S T; Athos, J; Figueroa, X A; Pineda, V V; Schaefer, M L; Chavkin, C C; Muglia, L J; Storm, D R

1999-08-01

155

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1997-08-01

156

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.

157

Impaired long-term memory retention: Common denominator for acutely or genetically reduced hippocampal neurogenesis in adult mice.  

Science.gov (United States)

In adult rodents, decreasing hippocampal neurogenesis experimentally using different approaches often impairs performance in hippocampus-dependent processes. Nonetheless, functional relevance of adult neurogenesis is far from being unraveled, and deficits so far described in animal models often lack reproducibility. One hypothesis is that such differences might be the consequence of the extent of the methodological specificity used to alter neurogenesis rather than the extent to which adult neurogenesis is altered. To address this, we focused on cranial irradiation, the most widely used technique to impair hippocampal neurogenesis and consequentially induce hippocampus-dependent behavioral deficits. To investigate the specificity of the technique, we thus exposed 4-5 months old female cyclin D2 knockout mice, a model lacking physiological levels of olfactory and hippocampal neurogenesis, to an X-ray dose of 10Gy, reported to specifically affect transiently amplifying precursors. After a recovery period of 1.5 months, behavioral tests were performed and probed for locomotor activity, habituation, anxiety, and spatial learning and memory. Spatial learning in the Morris water maze was intact in all experimental groups. Although spatial memory retention assessed 24h following acquisition was also intact in all mice, irradiated wild type and cyclin D2 knockout mice displayed memory deficits one week after acquisition. In addition, we observed significant differences in tests addressing anxiety and locomotor activity dependent on the technique used to alter neurogenesis. Whereas irradiated mice were hyperactive regardless of their genotype, cyclin D2 knockout mice were hypoactive in most of the tests and displayed altered habituation. The present study emphasizes that different approaches aimed at decreasing adult hippocampal neurogenesis may result in distinct behavioral impairments related to locomotion and anxiety. In contrast, spatial long-term memory retention is consistently altered after both approaches suggesting a plausible implication of hippocampal neurogenesis in this cognitive process. PMID:23714078

Ben Abdallah, Nada M-B; Filipkowski, Robert K; Pruschy, Martin; Jaholkowski, Piotr; Winkler, Juergen; Kaczmarek, Leszek; Lipp, Hans-Peter

2013-05-25

158

Impaired long-term memory retention: Common denominator for acutely or genetically reduced hippocampal neurogenesis in adult mice.  

UK PubMed Central (United Kingdom)

In adult rodents, decreasing hippocampal neurogenesis experimentally using different approaches often impairs performance in hippocampus-dependent processes. Nonetheless, functional relevance of adult neurogenesis is far from being unraveled, and deficits so far described in animal models often lack reproducibility. One hypothesis is that such differences might be the consequence of the extent of the methodological specificity used to alter neurogenesis rather than the extent to which adult neurogenesis is altered. To address this, we focused on cranial irradiation, the most widely used technique to impair hippocampal neurogenesis and consequentially induce hippocampus-dependent behavioral deficits. To investigate the specificity of the technique, we thus exposed 4-5 months old female cyclin D2 knockout mice, a model lacking physiological levels of olfactory and hippocampal neurogenesis, to an X-ray dose of 10Gy, reported to specifically affect transiently amplifying precursors. After a recovery period of 1.5 months, behavioral tests were performed and probed for locomotor activity, habituation, anxiety, and spatial learning and memory. Spatial learning in the Morris water maze was intact in all experimental groups. Although spatial memory retention assessed 24h following acquisition was also intact in all mice, irradiated wild type and cyclin D2 knockout mice displayed memory deficits one week after acquisition. In addition, we observed significant differences in tests addressing anxiety and locomotor activity dependent on the technique used to alter neurogenesis. Whereas irradiated mice were hyperactive regardless of their genotype, cyclin D2 knockout mice were hypoactive in most of the tests and displayed altered habituation. The present study emphasizes that different approaches aimed at decreasing adult hippocampal neurogenesis may result in distinct behavioral impairments related to locomotion and anxiety. In contrast, spatial long-term memory retention is consistently altered after both approaches suggesting a plausible implication of hippocampal neurogenesis in this cognitive process.

Ben Abdallah NM; Filipkowski RK; Pruschy M; Jaholkowski P; Winkler J; Kaczmarek L; Lipp HP

2013-09-01

159

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

Science.gov (United States)

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 retention tests after 6 months and, for two subjects, after 8 years. Results showed that individuals not only retained the task, but also reproduced their individual "style" of performance, even after 8 years. During practice, variables such as the two hands' frequency ratio and relative phase, changed at different rates, indicative of multiple time scales of neural processes. Frequency leakage across hands, reflecting intermanual crosstalk, attenuated at a significantly slower rate and was the only variable not maintained after 8 years. Complementing recent findings on neuroplasticity in gray and white matter, our study presents new behavioral evidence that highlights the multi-scale process of practice-induced changes and its remarkable persistence. Results suggest that motor memory may comprise not only higher-level task variables but also individual kinematic signatures. PMID:24032015

Park, Se-Woong; Dijkstra, Tjeerd M H; Sternad, Dagmar

2013-09-02

160

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

Science.gov (United States)

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 retention tests after 6 months and, for two subjects, after 8 years. Results showed that individuals not only retained the task, but also reproduced their individual “style” of performance, even after 8 years. During practice, variables such as the two hands' frequency ratio and relative phase, changed at different rates, indicative of multiple time scales of neural processes. Frequency leakage across hands, reflecting intermanual crosstalk, attenuated at a significantly slower rate and was the only variable not maintained after 8 years. Complementing recent findings on neuroplasticity in gray and white matter, our study presents new behavioral evidence that highlights the multi-scale process of practice-induced changes and its remarkable persistence. Results suggest that motor memory may comprise not only higher-level task variables but also individual kinematic signatures.

Park, Se-Woong; Dijkstra, Tjeerd M. H.; Sternad, Dagmar

2013-01-01

 
 
 
 
161

Long-Term Frozen Storage of Urine Samples: A Trouble to Get PCR Results in Schistosoma spp. DNA Detection?  

Science.gov (United States)

Background Human schistosomiasis remains a serious worldwide public health problem. At present, a sensitive and specific assay for routine diagnosis of schistosome infection is not yet available. The potential for detecting schistosome-derived DNA by PCR-based methods in human clinical samples is currently being investigated as a diagnostic tool with potential application in routine schistosomiasis diagnosis. Collection of diagnostic samples such as stool or blood is usually difficult in some populations. However, urine is a biological sample that can be collected in a non-invasive method, easy to get from people of all ages and easy in management, but as a sample for PCR diagnosis is still not widely used. This could be due to the high variability in the reported efficiency of detection as a result of the high variation in urine samples’ storage or conditions for handling and DNA preservation and extraction methods. Methodology/Principal Findings We evaluate different commercial DNA extraction methods from a series of long-term frozen storage human urine samples from patients with parasitological confirmed schistosomiasis in order to assess the PCR effectiveness for Schistosoma spp. detection. Patient? urine samples were frozen for 18 months up to 7 years until use. Results were compared with those obtained in PCR assays using fresh healthy human urine artificially contaminated with Schistosoma mansoni DNA and urine samples from mice experimentally infected with S. mansoni cercariae stored frozen for at least 12 months before use. PCR results in fresh human artificial urine samples using different DNA based extraction methods were much more effective than those obtained when long-term frozen human urine samples were used as the source of DNA template. Conclusions/Significance Long-term frozen human urine samples are probably not a good source for DNA extraction for use as a template in PCR detection of Schistosoma spp., regardless of the DNA method of extraction used.

Fernandez-Soto, Pedro; Velasco Tirado, Virginia; Carranza Rodriguez, Cristina; Perez-Arellano, Jose Luis; Muro, Antonio

2013-01-01

162

Impairment of long-term potentiation induction is essential for the disruption of spatial memory after microwave exposure.  

UK PubMed Central (United Kingdom)

Abstract Purpose: This study was intended to assess the impact of microwave exposure on learning and memory and to explore the underlying mechanisms. Materials and methods: 100 Wistar rats were exposed to a 2.856 GHz pulsed microwave field at average power densities of 0 mW/cm(2), 5 mW/cm(2), 10 mW/cm(2) and 50 mW/cm(2) for 6 min. The spatial memory was assessed by the Morris Water Maze (MWM) task. An in vivo study was conducted soon after microwave exposure to evaluate the changes of population spike (PS) amplitudes of long-term potentiation (LTP) in the medial perforant path (MPP)-dentate gyrus (DG) pathway. The structure of the hippocampus was observed by the light microscopy and the transmission electron microscopy (TEM) at 7 d after microwave exposure. Results: Our results showed that the rats exposed in 10 mW/cm(2) and 50 mW/cm(2) microwave displayed significant deficits in spatial learning and memory at 6 h, 1 d and 3 d after exposure. Decreased PS amplitudes were also found after 10 mW/cm(2) and 50 mW/cm(2) microwave exposure. Besides, varying degrees of degeneration of hippocampal neurons, decreased synaptic vesicles and blurred synaptic clefts were observed in the rats exposed in 10 mW/cm(2) and 50 mW/cm(2) microwave. Compared with the sham group, the rats exposed in 5 mW/cm(2) microwave showed no difference in the above experiments. Conclusions: This study suggested that impairment of LTP induction and the damages of hippocampal structure, especially changes of synapses, might contribute to cognitive impairment after microwave exposure.

Wang H; Peng R; Zhou H; Wang S; Gao Y; Wang L; Yong Z; Zuo H; Zhao L; Dong J; Xu X; Su Z

2013-06-01

163

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

Science.gov (United States)

Reductions in the integrity of white matter microstructure are thought to be a significant cause of age-related decline in mnemonic abilities, including working memory (WM) and long-term episodic memory (LTM). This study uses tract-based spatial statistics (TBSS) applied to diffusion tensor magnetic resonance images to explore correlations between white matter microstructure and verbal WM and LTM in a sample of 98 normal older adults. WM performance was associated with microstructure in left fronto-parietal pathways and LTM was associated with bilateral fronto-temporal pathways. Interhemispheric-frontal pathways (genu of the corpus callosum) were associated with both types of mnemonic function. We hypothesize that in normal aging, damage to certain white matter pathways may reduce the dynamic efficiency of mnemonic abilities by disrupting the connections within multiple distributed networks. By correlating white matter with two mnemonic functions in the same analysis, we have demonstrated that regional white matter networks may share common mnemonic functions but also may be differentiated for memory types. (PsycINFO Database Record (c) 2013 APA, all rights reserved). PMID:23957226

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

2013-08-19

164

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

UK PubMed Central (United Kingdom)

Reductions in the integrity of white matter microstructure are thought to be a significant cause of age-related decline in mnemonic abilities, including working memory (WM) and long-term episodic memory (LTM). This study uses tract-based spatial statistics (TBSS) applied to diffusion tensor magnetic resonance images to explore correlations between white matter microstructure and verbal WM and LTM in a sample of 98 normal older adults. WM performance was associated with microstructure in left fronto-parietal pathways and LTM was associated with bilateral fronto-temporal pathways. Interhemispheric-frontal pathways (genu of the corpus callosum) were associated with both types of mnemonic function. We hypothesize that in normal aging, damage to certain white matter pathways may reduce the dynamic efficiency of mnemonic abilities by disrupting the connections within multiple distributed networks. By correlating white matter with two mnemonic functions in the same analysis, we have demonstrated that regional white matter networks may share common mnemonic functions but also may be differentiated for memory types. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

Charlton RA; Barrick TR; Markus HS; Morris RG

2013-09-01

165

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

Energy Technology Data Exchange (ETDEWEB)

The Argonne team has gathered available data on monitoring wells and measured hydraulic heads from the Argonne 317/319 site and sent it to UIUC. Xiaodong Li, a research assistant supported by the project, has reviewed the data and is beginning to fit spatiotemporal statistical models to it. Another research assistant, Yonas Demissie, has gotten the site's Modflow model working and is developing a transport model that will be used to generate artificial data. Abhishek Singh, a third research assistant supported by the project, has performed a literature review on inverse modeling and is receiving training on the software that will be used in this project (D2K). He has also created two models of user preferences and successfully implemented them with an interactive genetic algorithm on test functions. Meghna Babbar, the fourth research assistant supported by the project, has created an interactive genetic algorithm code and initial user interface in D2K. Gayathri Gopalakrishnan, the last research assistant who is partially supported by the project, has collected and analyzed data from the phytoremediation systems at the 317/319 site. She has found good correlations between concentrations in the ground water and in branches of the trees, which indicates excellent promise for using the trees as cost-effective long-term monitoring of the contaminants.

Minsker, Barbara

2003-06-01

166

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

Directory of Open Access Journals (Sweden)

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 [(Ca)i] 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...

Philippe Leff; Héctor Romo; Maura Matus; Adriana Hernández; Juan Carlos Calva; Rodolfo Acevedo; Carlos Torner; Rafael Gutiérrez; Benito Anton

2002-01-01

167

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

International Nuclear Information System (INIS)

[en] 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.)

2008-01-01

168

The hippocampus supports high-resolution binding in the service of perception, working memory and long-term memory.  

Science.gov (United States)

It is well established that the hippocampus plays a critical role in our ability to recollect past events. A number of recent studies have indicated that the hippocampus may also play a critical role in working memory and perception, but these results have been highly controversial because other similar studies have failed to find evidence for hippocampal involvement. Thus, the precise role that the hippocampus plays in cognition is still debated. In the current paper, I propose that the hippocampus supports the generation and utilization of complex high-resolution bindings that link together the qualitative aspects that make up an event; these bindings are essential for recollection, and they can also contribute to performance across a variety of tasks including perception and working memory. An examination of the existing patient literature provides support for this proposal by showing that hippocampal damage leads to impairments on perception and working memory tasks that require complex high-resolution bindings. Conversely, hippocampal damage is much less likely to lead to impairments on tasks that require only low-resolution or simple associations/relations. The current proposal can be distinguished from earlier accounts of hippocampal function, and it generates a number of novel predictions that can be tested in future studies. PMID:23721964

Yonelinas, Andrew P

2013-05-27

169

Very long-term memories may be stored in the pattern of holes in the perineuronal net.  

UK PubMed Central (United Kingdom)

A hypothesis and the experiments to test it propose that very long-term memories, such as fear conditioning, are stored as the pattern of holes in the perineuronal net (PNN), a specialized ECM that envelops mature neurons and restricts synapse formation. The 3D intertwining of PNN and synapses would be imaged by serial-section EM. Lifetimes of PNN vs. intrasynaptic components would be compared with pulse-chase (15)N labeling in mice and (14)C content in human cadaver brains. Genetically encoded indicators and antineoepitope antibodies should improve spatial and temporal resolution of the in vivo activity of proteases that locally erode PNN. Further techniques suggested include genetic KOs, better pharmacological inhibitors, and a genetically encoded snapshot reporter, which will capture the pattern of activity throughout a large ensemble of neurons at a time precisely defined by the triggering illumination, drive expression of effector genes to mark those cells, and allow selective excitation, inhibition, or ablation to test their functional importance. The snapshot reporter should enable more precise inhibition or potentiation of PNN erosion to compare with behavioral consequences. Finally, biosynthesis of PNN components and proteases would be imaged.

Tsien RY

2013-07-01

170

Very long-term memories may be stored in the pattern of holes in the perineuronal net.  

Science.gov (United States)

A hypothesis and the experiments to test it propose that very long-term memories, such as fear conditioning, are stored as the pattern of holes in the perineuronal net (PNN), a specialized ECM that envelops mature neurons and restricts synapse formation. The 3D intertwining of PNN and synapses would be imaged by serial-section EM. Lifetimes of PNN vs. intrasynaptic components would be compared with pulse-chase (15)N labeling in mice and (14)C content in human cadaver brains. Genetically encoded indicators and antineoepitope antibodies should improve spatial and temporal resolution of the in vivo activity of proteases that locally erode PNN. Further techniques suggested include genetic KOs, better pharmacological inhibitors, and a genetically encoded snapshot reporter, which will capture the pattern of activity throughout a large ensemble of neurons at a time precisely defined by the triggering illumination, drive expression of effector genes to mark those cells, and allow selective excitation, inhibition, or ablation to test their functional importance. The snapshot reporter should enable more precise inhibition or potentiation of PNN erosion to compare with behavioral consequences. Finally, biosynthesis of PNN components and proteases would be imaged. PMID:23832785

Tsien, Roger Y

2013-07-05

171

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)

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…

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

2013-01-01

172

Hippocampal Overexpression of Mutant CREB Blocks Long-Term, but Not Short-Term Memory for a Socially Transmitted Food Preference  

Science.gov (United States)

Phosphorylation of the transcription factor CREB on Ser133 is implicated in the establishment of long-term memory for hippocampus-dependent tasks, including spatial learning and contextual fear conditioning. We reported previously that training on a hippocampus-dependent social transmission of food preference (STFP) task increases CREB…

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

2005-01-01

173

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

Directory of Open Access Journals (Sweden)

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

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

2013-01-01

174

Comparison of the Effects of Dose-dependent Zinc Chloride on Short-term and Long-term Memory in Young Male Rats  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of the present study was to evaluate the effects of dose-dependent of zinc chloride on short-term and long-term memory in a shuttle box. Young Wistar rats (94±10 g) (age 27-30 days) consumed zinc chloride drinking water in five different doses (20, 30, 50, 70 and 100 mg kg-1day-1) for two weeks by gavage. After 14 days on experimental diets, a shuttle box used to test short- and long-term memory. Two criteria considering for behavioral test, including latency in entering dark chamber and time spent in the dark chamber. This experiment shows that after 2 weeks oral administration of ZnCl2 with (20, 30 and 50 mg kg-1 day-1) doses, the rat’s working (short-term) has been improved (p2 with 30 mg kg-1 day-1 dose has been more effected than other doses (p2 with 100 mg kg-1 day-1, has been shown significant impairment in working memory (p-1 day-1 dose for two weeks was more effective than other doses on short-term memory. But consumption of ZnCl2 with 100 mg kg-1 day-1 dose for two week had the negative effect on short-term memory. On the other hand, zinc supplementation did not have an effect on long-term memory.

A.A. Moazedi; Z. Ghotbeddin; G.H. Parham

2007-01-01

175

Long-term antibody memory induced by synthetic peptide vaccination is protective against Streptococcus pyogenes infection and is independent of memory T cell help.  

UK PubMed Central (United Kingdom)

Streptococcus pyogenes (group A Streptococcus [GAS]) is a leading human pathogen associated with a diverse array of mucosal and systemic infections. Vaccination with J8, a conserved region synthetic peptide derived from the M-protein of GAS and containing only 12 aa from GAS, when conjugated to diphtheria toxoid, has been shown to protect mice against a lethal GAS challenge. Protection has been previously shown to be Ab-mediated. J8 does not contain a dominant GAS-specific T cell epitope. The current study examined long-term Ab memory and dissected the role of B and T cells. Our results demonstrated that vaccination generates specific memory B cells (MBC) and long-lasting Ab responses. The MBC response can be activated following boost with Ag or limiting numbers of whole bacteria. We further show that these memory responses protect against systemic infection with GAS. T cell help is required for activation of MBC but can be provided by naive T cells responding directly to GAS at the time of infection. Thus, individuals whose T cells do not recognize the short synthetic peptide in the vaccine will be able to generate a protective and rapid memory Ab response at the time of infection. These studies significantly strengthen previous findings, which showed that protection by the J8-diphtheria toxoid vaccine is Ab-mediated and suggest that in vaccine design for other organisms the source of T cell help for Ab responses need not be limited to sequences from the organism itself.

Pandey M; Wykes MN; Hartas J; Good MF; Batzloff MR

2013-03-01

176

Long-term monitoring of the Danube river-Sampling techniques, radionuclide metrology and radioecological assessment  

International Nuclear Information System (INIS)

Sampling techniques and radiometric methods, developed and applied in a comprehensive radioecological study of the Danube River are presented. Results and radiometric data of sediment samples, collected by sediment traps in Austria and additionally by grab sampling in the Danube during research cruises between Germany and the delta (Black sea) are shown and discussed. Goal of the investigation is the protection of public and environment, especially the sustainable use and conservation of human freshwater resources against harmful radioactive exposure.

2009-01-01

177

Long-term monitoring of the Danube river-Sampling techniques, radionuclide metrology and radioecological assessment  

Energy Technology Data Exchange (ETDEWEB)

Sampling techniques and radiometric methods, developed and applied in a comprehensive radioecological study of the Danube River are presented. Results and radiometric data of sediment samples, collected by sediment traps in Austria and additionally by grab sampling in the Danube during research cruises between Germany and the delta (Black sea) are shown and discussed. Goal of the investigation is the protection of public and environment, especially the sustainable use and conservation of human freshwater resources against harmful radioactive exposure.

Maringer, F.J. [Federal Office of Metrology and Surveying (BEV), Arltgasse 35, 1160 Wien (Austria); University of Natural Resources and Applied Live Science (BOKU), Low-level Counting Laboratory Arsenal, Faradaygasse 3, Arsenal 214, 1030 Wien (Austria)], E-mail: franz-josef.maringer@bev.gv.at; Gruber, V. [University of Natural Resources and Applied Live Science (BOKU), Low-level Counting Laboratory Arsenal, Faradaygasse 3, Arsenal 214, 1030 Wien (Austria); Hrachowitz, M. [University of Aberdeen, Scotland (United Kingdom); Baumgartner, A.; Weilner, S.; Seidel, C. [University of Natural Resources and Applied Live Science (BOKU), Low-level Counting Laboratory Arsenal, Faradaygasse 3, Arsenal 214, 1030 Wien (Austria)

2009-05-15

178

Long-term performance and stability of molecular shotgun lipidomic analysis of human plasma samples.  

UK PubMed Central (United Kingdom)

The stability of the lipid concentration levels in shotgun lipidomics analysis was tracked over a period of 3.5 years. Concentration levels in several lipid classes, such as phospholipids, were determined in human plasma lipid extracts. Impact of the following factors on the analysis was investigated: sample amount, internal standard amount, and sample dilution factor. Moreover, the reproducibility of lipid profiles obtained in both polarity modes was evaluated. Total number of samples analyzed was approximately 6800 and 7300 samples in negative and positive ion modes, respectively, out of which 610 and 639 instrument control samples were used in stability calculations. The assessed shotgun lipidomics approach showed to be remarkably robust and reproducible, requiring no batch corrections. Coefficients of variation (CVs) of lipid mean concentration measured with optimized analytical parameters were typically less than 15%. The high reproducibility indicated that no lipid degradation occurred during the monitored time period.

Heiskanen LA; Suoniemi M; Ta HX; Tarasov K; Ekroos K

2013-09-01

179

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

UK PubMed Central (United Kingdom)

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.

Irvine GV; Shelly A

2013-08-01

180

Limitations of dioxin emission testing by EN 1948 compared to long term sampling  

Energy Technology Data Exchange (ETDEWEB)

According to the EN1948 standard dioxin emissions from municipal waste incinerators are sampled during 6 to 8 hours. The effectiveness of this measurement in testing compliance with the emission limit of 0.1 ng TEQ/Nm{sup 3} as a time average is limited due to the typical property that dioxins are products of incomplete combustion, and that high emissions during starts, stops, or failing of gas cleaning equipment may occur. This is illustrated by data from the IVOO incinerator at Oostende in Belgium where, in 1998, after an extension of the gas cleaning, dioxin concentration results from the EN1948 method were 30 to 50 times lower than the averages obtained by continuous sampling. Results over 1999 and 2000 from both continuous sampling and 6-hour samples are given and these data show better agreement while the incinerators emissions are constantly below 0,1 ng TEQ/Nm{sup 3}. (orig.)

De Fre, R.; Wevers, M. [Flemish Institute for Technological Research (Vito), Mol (Belgium)

2001-07-01

 
 
 
 
181

Hyperosmotic priming of Arabidopsis seedlings establishes a long-term somatic memory accompanied by specific changes of the epigenome.  

UK PubMed Central (United Kingdom)

BACKGROUND: In arid and semi-arid environments, drought and soil salinity usually occur at the beginning and end of a plant's life cycle, offering a natural opportunity for the priming of young plants to enhance stress tolerance in mature plants. Chromatin marks, such as histone modifications, provide a potential molecular mechanism for priming plants to environmental stresses, but whether transient exposure of seedlings to hyperosmotic stress leads to chromatin changes that are maintained throughout vegetative growth remains unclear. RESULTS: We have established an effective protocol for hyperosmotic priming in the model plant Arabidopsis, which includes a transient mild salt treatment of seedlings followed by an extensive period of growth in control conditions. Primed plants are identical to non-primed plants in growth and development, yet they display reduced salt uptake and enhanced drought tolerance after a second stress exposure. ChIP-seq analysis of four histone modifications revealed that the priming treatment altered the epigenomic landscape; the changes were small but they were specific for the treated tissue, varied in number and direction depending on the modification, and preferentially targeted transcription factors. Notably, priming leads to shortening and fractionation of H3K27me3 islands. This effect fades over time, but is still apparent after a ten day growth period in control conditions. Several genes with priming-induced differences in H3K27me3 showed altered transcriptional responsiveness to the second stress treatment. CONCLUSION: Experience of transient hyperosmotic stress by young plants is stored in a long-term somatic memory comprising differences of chromatin status, transcriptional responsiveness and whole plant physiology.

Sani E; Herzyk P; Perrella G; Colot V; Amtmann A

2013-06-01

182

Analyses of metallic first mirror samples after long term plasma exposure in Tore Supra  

Energy Technology Data Exchange (ETDEWEB)

Metallic mirrors are foreseen in ITER diagnostic systems as optical elements directly viewing the plasma radiation. In the frame of an EFDA contract, metallic mirror samples have been exposed for long pulse plasma discharges in Tore Supra (TS) in order to investigate surface modifications caused by erosion and re-deposition processes. Three different materials have been selected: mono-crystalline molybdenum (mc-Mo), polycrystalline stainless steel (SS) and copper (Cu). The mc-Mo samples showed after TS exposure almost no surface roughness modifications and the lowest net-erosion. A slight reflectivity reduction, most pronounced in the near UV, is attributed to light absorption in a thin carbon deposit. Cu mirrors showed by far the highest surface roughness, erosion and diffusive reflectivity. Comparative laboratory glow discharge experiments with virgin reference samples and numerical simulations of erosion/deposition confirm the dominant contribution of conditioning procedures to erosion of mirrors exposed (without shutter protection) in Tore Supra. (authors)

Lipa, M.; Schunke, B.; Gil, Ch.; Bucalossi, J. [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Voitsenya, V.S.; Konovalov, V. [Institut of Plasma Physics, NSC KIPT (Ukraine); Vukolov, K. [Kurchatov Institute, NFI RRC, Moscow (Russian Federation); Balden, M. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Temmerman, G. de; Oelhafen, P. [Basel Univ. (Switzerland). Inst. fuer Physik; Litnovsky, A.; Wienhold, P. [Institut fuer Plasmaphysik, Forschungszentrum Julich (Germany)

2005-07-01

183

Analyses of metallic first mirror samples after long term plasma exposure in Tore Supra  

Energy Technology Data Exchange (ETDEWEB)

Metallic mirrors are foreseen in ITER diagnostic systems as optical elements directly viewing the plasma radiation. In the frame of an EFDA contract, metallic mirror samples have been exposed for long pulse plasma discharges in Tore Supra (TS) in order to investigate surface modifications caused by erosion and re-deposition processes. Three different materials have been selected: mono-crystalline molybdenum (mc-Mo), polycrystalline stainless steel (SS) and copper (Cu). The mc-Mo samples showed after TS exposure almost no surface roughness modifications and the lowest net-erosion. A slight reflectivity reduction, most pronounced in the near UV, is attributed to light absorption in a thin carbon deposit. Cu mirrors showed by far the highest surface roughness, erosion and diffusive reflectivity. Comparative laboratory glow discharge experiments with virgin reference samples and numerical simulations of erosion/deposition confirm the dominant contribution of conditioning procedures to erosion of mirrors exposed (without shutter protection) in Tore Supra.

Lipa, M. [Association Euratom-CEA, CEA/DSM/DRFC, CEA-Cadarache, 13108 Saint-Paul-Lez-Durance (France)]. E-mail: manfred.lipa@cea.fr; Schunke, B. [Association Euratom-CEA, CEA/DSM/DRFC, CEA-Cadarache, 13108 Saint-Paul-Lez-Durance (France); Gil, Ch. [Association Euratom-CEA, CEA/DSM/DRFC, CEA-Cadarache, 13108 Saint-Paul-Lez-Durance (France); Bucalossi, J. [Association Euratom-CEA, CEA/DSM/DRFC, CEA-Cadarache, 13108 Saint-Paul-Lez-Durance (France); Voitsenya, V.S. [Institute of Plasma Physics, NSC KIPT, Akademichna St. 1, 61108 Kharkov (Ukraine); Konovalov, V. [Institute of Plasma Physics, NSC KIPT, Akademichna St. 1, 61108 Kharkov (Ukraine); Vukolov, K. [NFI RRC Kurchatov Institute, Moscow (Russian Federation); Balden, M. [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany); De Temmerman, G. [Institut fuer Physik, Universitaet Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Oelhafen, P. [Institut fuer Physik, Universitaet Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Litnovsky, A. [Institut fuer Plasmaphysik, Forschungszentrum Juelich, D-42425 Juelich (Germany); Wienhold, P. [Institut fuer Plasmaphysik, Forschungszentrum Juelich, D-42425 Juelich (Germany)

2006-02-15

184

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

Science.gov (United States)

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

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

2002-01-01

185

Biomarkers of exposure in Monday morning urine samples as a long-term measure of exposure to aromatic diisocyanates.  

UK PubMed Central (United Kingdom)

PURPOSE: Exposure to diisocyanates is a known occupational hazard. One method for monitoring occupational exposure is by analyzing biomarkers in hydrolyzed urine and plasma. The half-life of the biomarkers in plasma is about 3 weeks, and the urinary elimination is divided into one fast (hours) and one slow phases (weeks). Polymorphism in glutathione S-transferase enzymes (GST) is earlier shown to modify the metabolism. The aim of the study was to assess whether biomarkers of exposure in urine collected after two non-exposed days correlate with levels in plasma and whether they can be used as a measure for long-term exposure to aromatic diisocyanates and further whether polymorphisms in GST influenced the correlations. METHODS: Biomarkers of exposure was analyzed in urine and blood samples collected from 24 workers, exposed to at least one of toluene-, methylenediphenyl- or naphthalene diisocyanate, on a Monday morning after at least two unexposed days. Moreover, genotype was determined for 19 of the workers. RESULTS: The corresponding specific gravity-adjusted biomarkers in urine and plasma levels for the different diisocyanates correlated well (r between 0.689 and 0.988). When taking all samples together, the correlation coefficient was 0.926. Polymorphism in the GSTM1 genotype seemed to modify the association. CONCLUSION: Urine collected after two unexposed days can possibly be used as long-term biomarker of exposure for aromatic diisocyanates.

Tinnerberg H; Broberg K; Lindh CH; Jönsson BA

2013-04-01

186

Long-term accuracy and precision of PIXE and PIGE measurements for thin and thick sample analyses  

International Nuclear Information System (INIS)

[en] This paper describes PIXE/PIGE measurements on thin Micromatter Standard (±5%) foils run over a period of 10 years. The selected foils were typically 50 ?g/cm2 thick and covered the commonly used PIXE X-ray energy range 1.4-20 keV and the light elements F and Na for PIGE studies. For the thousands of thick obsidian and pottery samples analysed over a 6-year period, the Ohio Red Clay standard has been used for both PIXE and PIGE calibration of a range of elements from Li to Rb. For PIXE, the long-term accuracy could be as low as ±1.6% for major elements with precision ranging from ±5% to ±10% depending on the elemental concentration. For PIGE, accuracies were around ±5% with precision ranging from ±5% in thick samples to ±15% in thin samples or for low yield ?-ray production

2002-01-01

187

Long-term accuracy and precision of PIXE and PIGE measurements for thin and thick sample analyses  

Energy Technology Data Exchange (ETDEWEB)

This paper describes PIXE/PIGE measurements on thin Micromatter Standard ({+-}5%) foils run over a period of 10 years. The selected foils were typically 50 {mu}g/cm{sup 2} thick and covered the commonly used PIXE X-ray energy range 1.4-20 keV and the light elements F and Na for PIGE studies. For the thousands of thick obsidian and pottery samples analysed over a 6-year period, the Ohio Red Clay standard has been used for both PIXE and PIGE calibration of a range of elements from Li to Rb. For PIXE, the long-term accuracy could be as low as {+-}1.6% for major elements with precision ranging from {+-}5% to {+-}10% depending on the elemental concentration. For PIGE, accuracies were around {+-}5% with precision ranging from {+-}5% in thick samples to {+-}15% in thin samples or for low yield {gamma}-ray production.

Cohen, David D. E-mail: dcz@ansto.gov.au; Siegele, Rainer; Orlic, Ivo; Stelcer, Ed

2002-04-01

188

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

Directory of Open Access Journals (Sweden)

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.

Caputo Mariela; Bosio Luis A; Corach Daniel

2011-01-01

189

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

UK PubMed Central (United Kingdom)

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.

Caputo M; Bosio LA; Corach D

2011-01-01

190

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

UK PubMed Central (United Kingdom)

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-frequency stimulation caused comparable synaptic depotentiation in both wild type and AC1 transgenic (AC1 TG) mice. Although previous studies have suggested the function of LTD in spatial memory flexibility, AC1 TG mice showed not only better initial learning in the Morris water maze, but also faster acquisition and increased ratio of new memory formation to old memory retention during the reversal platform training. In the memory extinction test, which requires suppression of old memory without involving the acquisition of the new platform information, AC1 TG and wild type mice showed comparable performance. Our results demonstrate new functions of Ca2+ -stimulated AC1, and also suggest that certain aspects of hippocampus-dependent behavioral flexibility may not require intact LTD.

Zhang M; Wang H

2013-07-01

191

Intimate partner violence and long-term psychosocial functioning in a national sample of American women.  

UK PubMed Central (United Kingdom)

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 among women who reported IPV at wave 1 and explored whether certain predictors were related to ending an abusive relationship with an intimate partner during the period. Women with IPV at wave 1, compared to women without IPV, were significantly more likely to experience a greater degree of depressive symptoms and functional impairment and less self-esteem and life satisfaction at the 5-year follow-up. Also, nearly half of the women in an abusive relationship left the relationship within the period. Leaving the abusive relationship was associated with lower individual income and more social support at wave 1.

Zlotnick C; Johnson DM; Kohn R

2006-02-01

192

Automatic segmentation of long-term ECG signals corrupted with broadband noise based on sample entropy.  

UK PubMed Central (United Kingdom)

Biomedical signals are nonstationary in nature, namely, their statistical properties are time-dependent. Such changes in the underlying statistical properties of the signal and the effects of external noise often affect the performance and applicability of automatic signal processing methods that require stationarity. A number of methods have been proposed to address the problem of finding stationary signal segments within larger nonstationary signals. In this framework, processing and analysis are applied to each resulting locally stationary segment separately. The method proposed in this paper addresses the problem of finding locally quasi-stationary signal segments. Particularly, our proposed algorithm is designed to solve the specific problem of segmenting semiperiodic biomedical signals corrupted with broadband noise according to the various degrees of external noise power. It is based on the sample entropy and the relative sensitivity of this signal regularity metric to changes in the underlying signal properties and broadband noise levels. The assessment of the method was carried out by means of experiments on ECG signals drawn from the MIT-BIH arrhythmia database. The results were measured in terms of false alarms based on the changepoint detection bias. In summary, the results achieved were a sensitivity of 97%, and an error of 16% for records corrupted with muscle artifacts.

Micó P; Mora M; Cuesta-Frau D; Aboy M

2010-05-01

193

Long-term variations of solar corpuscular fluxes based on lunar soil samples  

Science.gov (United States)

We report the results of age determination of a lunar soil column, delivered by the Luna 16 mission in September 1970 from the Sea of Fertility. We elaborated and applied the soil age determination method using the kinetic parameter, the regolith accumulation rate. The age of the soil delivered by Luna 16 is about 90 Myr. The isotopic ratio of 3He/4He in the column is slightly higher than in the soil column delivered by the Luna 24 mission. The abundance of helium in the fine fraction of the soil (about 100 µm) is significantly higher and is close to the maximum abundance from the Luna 24 soil column. These differences are most likely associated with the variations of solar corpuscular fluxes. Based on the measurements of the helium isotope abundance in the samples of lunar soil columns, we have estimated the values of ancient solar fluxes of protons and helium and variations thereof in the time interval of up to 600 Myr. We demonstrate that during this epoch there were two strong bursts of the helium flux, about 80 and 470 Myr ago, respectively. The existence of the first peak was assumed earlier from the paleodendrochronological data.

Anufriev, G. S.

2013-07-01

194

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

DEFF Research Database (Denmark)

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

Demant, Helle; Ladewig, Jan

2011-01-01

195

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

CERN Multimedia

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

da Silva, J Gomes; Bonfils, X

2010-01-01

196

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

Energy Technology Data Exchange (ETDEWEB)

Yonas Demissie, a research assistant supported by the project, has successfully created artificial data and assimilated it into coupled Modflow and artificial neural network models. His initial findings show that the neural networks help correct errors in the Modflow models. Abhishek Singh has used test cases from the literature to show that performing model calibration with an interactive genetic algorithm results in significantly improved parameter values. Meghna Babbar, the third research assistant supported by the project, has found similar results when applying an interactive genetic algorithms to long-term monitoring design. She has also developed new types of interactive genetic algorithms that significantly improve performance. Gayathri Gopalakrishnan, the last research assistant who is partially supported by the project, has shown that sampling branches of phytoremediation trees is an accurate approach to estimating soil and groundwater contaminations in areas surrounding the trees at the Argonne 317/319 site.

Minsker, Barbara

2005-06-01

197

The effects of torture-related injuries on long-term psychological distress in a Punjabi Sikh sample.  

UK PubMed Central (United Kingdom)

Torture survivors often report chronic debilitating physical and psychological distress. Prior research on the relationship between physical and psychological trauma suggests that the 2 are not independent. Injury sustained during torture may increase the likelihood of subsequent distress as either a moderator or mediator. For long-term psychopathology in a sample of Punjabi Sikh survivors of human rights violations (N = 116), chronic injuries mediated the path between torture and posttraumatic stress disorder, specifically the severity of numbing symptoms. Although injuries were associated with major depression, torture was not, and injuries did not moderate the relationship between major depression and torture. Chronic injuries may represent trauma severity or persistent traumatic cues. These findings emphasize connections between physical and psychological trauma and the importance of an interdisciplinary approach to torture treatment.

Rasmussen A; Rosenfeld B; Reeves K; Keller AS

2007-11-01

198

The effects of torture-related injuries on long-term psychological distress in a Punjabi Sikh sample.  

Science.gov (United States)

Torture survivors often report chronic debilitating physical and psychological distress. Prior research on the relationship between physical and psychological trauma suggests that the 2 are not independent. Injury sustained during torture may increase the likelihood of subsequent distress as either a moderator or mediator. For long-term psychopathology in a sample of Punjabi Sikh survivors of human rights violations (N = 116), chronic injuries mediated the path between torture and posttraumatic stress disorder, specifically the severity of numbing symptoms. Although injuries were associated with major depression, torture was not, and injuries did not moderate the relationship between major depression and torture. Chronic injuries may represent trauma severity or persistent traumatic cues. These findings emphasize connections between physical and psychological trauma and the importance of an interdisciplinary approach to torture treatment. PMID:18020719

Rasmussen, Andrew; Rosenfeld, Barry; Reeves, Kim; Keller, Allen S

2007-11-01

199

Newborn neurons in the olfactory bulb selected for long-term survival through olfactory learning are prematurely suppressed when the olfactory memory is erased.  

Science.gov (United States)

A role for newborn neurons in olfactory memory has been proposed based on learning-dependent modulation of olfactory bulb neurogenesis in adults. We hypothesized that if newborn neurons support memory, then they should be suppressed by memory erasure. Using an ecological approach in mice, we showed that behaviorally breaking a previously learned odor-reward association prematurely suppressed newborn neurons selected to survive during initial learning. Furthermore, intrabulbar infusions of the caspase pan-inhibitor ZVAD (benzyloxycarbonyl-Val-Ala-Asp) during the behavioral odor-reward extinction prevented newborn neurons death and erasure of the odor-reward association. Newborn neurons thus contribute to the bulbar network plasticity underlying long-term memory. PMID:22016522

Sultan, Sébastien; Rey, Nolwen; Sacquet, Joelle; Mandairon, Nathalie; Didier, Anne

2011-10-19

200

Newborn neurons in the olfactory bulb selected for long-term survival through olfactory learning are prematurely suppressed when the olfactory memory is erased.  

UK PubMed Central (United Kingdom)

A role for newborn neurons in olfactory memory has been proposed based on learning-dependent modulation of olfactory bulb neurogenesis in adults. We hypothesized that if newborn neurons support memory, then they should be suppressed by memory erasure. Using an ecological approach in mice, we showed that behaviorally breaking a previously learned odor-reward association prematurely suppressed newborn neurons selected to survive during initial learning. Furthermore, intrabulbar infusions of the caspase pan-inhibitor ZVAD (benzyloxycarbonyl-Val-Ala-Asp) during the behavioral odor-reward extinction prevented newborn neurons death and erasure of the odor-reward association. Newborn neurons thus contribute to the bulbar network plasticity underlying long-term memory.

Sultan S; Rey N; Sacquet J; Mandairon N; Didier A

2011-10-01

 
 
 
 
201

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-03-15

202

Regular exercise prevents sleep deprivation associated impairment of long-term memory and synaptic plasticity in the CA1 area of the hippocampus.  

UK PubMed Central (United Kingdom)

STUDY OBJECTIVES: The present study aimed to investigate the effects of treadmill exercise on sleep deprivation (S-D)-induced impairment of hippocampal dependent long-term memory, late phase long-term potentiation (L-LTP) and its signaling cascade in the cornu ammonis 1 (CA1) area. EXPERIMENTAL DESIGN: Animals were conditioned to run on treadmills for 4 weeks then deprived of sleep for 24 h using the columns-in-water method. We tested the effect of exercise and/or S-D on behavioral performance using a post-learning paradigm in the radial arm water maze (RAWM) and in vivo extracellular recording in the CA1 area. The levels of L-LTP-related molecules in the CA1 area were then assessed both before and after L-LTP induction. MEASUREMENTS AND RESULTS: After 24 h of S-D, spatial long-term memory impairment in the RAWM and L-LTP suppression was prevented by 4 weeks of regular exercise. Regular exercise also restored the S-D-associated decreases in the basal levels of key signaling molecules such as: calcium/calmodulin kinase IV (CaMKIV), mitogen-activated protein kinase (MAPK/ERK), phosphorylated cAMP response element-binding protein (P-CREB) and brain derived neurotrophic factor (BDNF), in the CA1 area. After L-LTP induction, regular exercise also prevented the S-D-induced down regulation of BDNF and P-CREB protein levels. CONCLUSIONS: The results suggest that our exercise protocol may prevent 24-h S-D-induced impairments in long-term memory and LTP by preventing deleterious changes in the basal and post-stimulation levels of P-CREB and BDNF associated with S-D.

Zagaar M; Dao A; Levine A; Alhaider I; Alkadhi K

2013-05-01

203

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)

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

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

2006-01-01

204

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

DEFF Research Database (Denmark)

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.

Reimers, Tonny Solveig; Mortensen, Erik Lykke

2007-01-01

205

Low-flow, long-term air sampling under normal domestic activity to measure house dust mite and cockroach allergens.  

Science.gov (United States)

Successful applications of air sampling for the quantification of exposure to indoor allergens have been reported, but its efficiency is still controversial. We evaluated whether the low-flow, long-term air sampling in normal domestic activity conditions can quantify the exposure of house dust mites (HDM) and cockroaches (CR) allergens or not. Airborne Der f 1 and Bla g 1 were captured with a personal air sampler in 25 bedrooms during normal domestic activity. Quantification of the major allergens in the reservoir dust and the extraction of the air sampler filters were done with two-site ELISA kits. Airborne Der f 1 was measured above the threshold level of detection in 15 houses (60%). Detection rate of airborne Der f 1 was significantly higher in those houses where D. farinae was microscopically found in the reservoir dusts (76.5% vs. 25%, chi 2 = 6.0, p = 0.014). Airborne Der f 1 was more frequently detected in the houses with higher Der f 1 (> or = 10 micrograms/g dust) in bedding reservoir dust than the other group (91% vs. 35.7%, chi 2 = 7.819, p = 0.005), and the median value of airborne Der f 1 was also significantly higher in that group (14.0 pg/m3 vs. below detection limit, p = 0.002). Airborne Der f 1 was significantly correlated with Der f 1 in bedding reservoir dust (r = 0.591, p < 0.01). Airborne Bla g 1 was measured with ELISA in 16 houses (64%), and it was more frequently detected in the houses where the CRs were captured by adhesive traps (91% vs. 57%, chi 2 = 3,484, p = 0.06). The median concentration of Bla g 1 in the filter was also higher in the houses with captured CRs (0.12 vs. 0.05 mU/m3, p = 0.06), but the level of Bla g 1 did not correlate with that of the bedding dusts or the floor dusts of kitchen. These results suggested that airborne HDM or CR allergens could be measured by low-flow, long-term air sampling, and that it might be one of appropriate modalities for evaluating personal exposure to HDM and CR allergens. PMID:12926189

Park, Jung Won; Kim, Cheol Woo; Kang, Dae Bong; Lee, In Young; Choi, Soo Young; Yong, Tai-Soon; Shin, Dong Cheon; Kim, Kyu Earn; Hong, Chein-Soo

2002-01-01

206

Low-flow, long-term air sampling under normal domestic activity to measure house dust mite and cockroach allergens.  

UK PubMed Central (United Kingdom)

Successful applications of air sampling for the quantification of exposure to indoor allergens have been reported, but its efficiency is still controversial. We evaluated whether the low-flow, long-term air sampling in normal domestic activity conditions can quantify the exposure of house dust mites (HDM) and cockroaches (CR) allergens or not. Airborne Der f 1 and Bla g 1 were captured with a personal air sampler in 25 bedrooms during normal domestic activity. Quantification of the major allergens in the reservoir dust and the extraction of the air sampler filters were done with two-site ELISA kits. Airborne Der f 1 was measured above the threshold level of detection in 15 houses (60%). Detection rate of airborne Der f 1 was significantly higher in those houses where D. farinae was microscopically found in the reservoir dusts (76.5% vs. 25%, chi 2 = 6.0, p = 0.014). Airborne Der f 1 was more frequently detected in the houses with higher Der f 1 (> or = 10 micrograms/g dust) in bedding reservoir dust than the other group (91% vs. 35.7%, chi 2 = 7.819, p = 0.005), and the median value of airborne Der f 1 was also significantly higher in that group (14.0 pg/m3 vs. below detection limit, p = 0.002). Airborne Der f 1 was significantly correlated with Der f 1 in bedding reservoir dust (r = 0.591, p < 0.01). Airborne Bla g 1 was measured with ELISA in 16 houses (64%), and it was more frequently detected in the houses where the CRs were captured by adhesive traps (91% vs. 57%, chi 2 = 3,484, p = 0.06). The median concentration of Bla g 1 in the filter was also higher in the houses with captured CRs (0.12 vs. 0.05 mU/m3, p = 0.06), but the level of Bla g 1 did not correlate with that of the bedding dusts or the floor dusts of kitchen. These results suggested that airborne HDM or CR allergens could be measured by low-flow, long-term air sampling, and that it might be one of appropriate modalities for evaluating personal exposure to HDM and CR allergens.

Park JW; Kim CW; Kang DB; Lee IY; Choi SY; Yong TS; Shin DC; Kim KE; Hong CS

2002-01-01

207

Selective pharmacogenetic inhibition of mammalian target of Rapamycin complex I (mTORC1) blocks long-term synaptic plasticity and memory storage.  

UK PubMed Central (United Kingdom)

Both the formation of long-term memory (LTM) and late-long-term potentiation (L-LTP), which is thought to represent the cellular model of learning and memory, require de novo protein synthesis. The mammalian target of Rapamycin (mTOR) complex I (mTORC1) integrates information from various synaptic inputs and its best characterized function is the regulation of translation. Although initial studies have shown that rapamycin reduces L-LTP and partially blocks LTM, recent genetic and pharmacological evidence indicating that mTORC1 promotes L-LTP and LTM is controversial. Thus, the role of mTORC1 in L-LTP and LTM is unclear. To selectively inhibit mTORC1 activity in the adult brain, we used a "pharmacogenetic" approach that relies on the synergistic action of a drug (rapamycin) and a genetic manipulation (mTOR heterozygotes, mTOR(+/-) mice) on the same target (mTORC1). Although L-LTP and LTM are normal in mTOR(+/-) mice, application of a low concentration of rapamycin-one that is subthreshold for WT mice-prevented L-LTP and LTM only in mTOR(+/-) mice. Furthermore, we found that mTORC1-mediated translational control is required for memory reconsolidation. We provide here direct genetic evidence supporting the role of mTORC1 in L-LTP and behavioral memory.

Stoica L; Zhu PJ; Huang W; Zhou H; Kozma SC; Costa-Mattioli M

2011-03-01

208

Central memory CD4 T cells are associated with incomplete restoration of the CD4 T cell pool after treatment-induced long-term undetectable HIV viraemia.  

UK PubMed Central (United Kingdom)

OBJECTIVES: It is unclear to what extent T cell reconstitution may be possible in HIV-1-infected individuals on continuous successful highly active antiretroviral therapy (HAART). Herein, we analysed distinct phenotypic markers of immune recovery in patients with undetectable viraemia for 8 years, taking as reference untreated patients and healthy controls. METHODS: Seventy-two subjects were examined: 28 HIV-1+ patients on successful long-term HAART, 24 HIV-1+ untreated viraemic patients and 20 age-matched healthy controls. Analysis of naive and memory CD4 and CD8 T cells was combined with measurements of activation status (expression of CD38) and with thymic function (expression of CD31). Statistical significance was determined by non-parametric tests. RESULTS: After long-term HAART, the majority of parameters were normalized compared with age-matched control values, including T cell activation and thymic function. However, absolute counts of naive and central memory CD4 T cells remained below normal levels. The only parameters significantly associated with CD4 counts at the end of follow-up were the pre-HAART CD4 count (???±?SD?=?0.54?±?0.16, P?=?0.003) and the level of CD4 central memory cells at the end of follow-up (??±?SD?=?1.18?±?0.23, P?350 cells/mm(3) reached a complete normalization of CD4 counts. CONCLUSIONS: Even after long-term successful HAART, complete CD4 restoration may be attainable only in patients starting therapy with moderately high CD4 counts, prompting early initiation of antiretroviral therapy. Incomplete CD4 restoration may be associated with a defective restoration of central memory CD4 T cells, a cell subset with a pivotal role in T cell homeostasis.

Rallón N; Sempere-Ortells JM; Soriano V; Benito JM

2013-07-01

209

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

UK PubMed Central (United Kingdom)

Memory impairment is a common feature of conditions that involve changes in inflammatory signaling in the brain, including traumatic brain injury, infection, neurodegenerative disorders, and normal aging. However, the causal importance of inflammatory mediators in cognitive impairments in these conditions remains unclear. Here we show that specific immune proteins, members of the major histocompatibility complex class I (MHC class I), are essential for normal hippocampus-dependent memory, and are specifically required for NMDAR-dependent forms of long-term depression (LTD) in the healthy adult hippocampus. In ?2m(-/-)TAP(-/-)mice, which lack stable cell-surface expression of most MHC class I proteins, NMDAR-dependent LTD in area CA1 of adult hippocampus is abolished, while NMDAR-independent forms of potentiation, facilitation, and depression are unaffected. Altered NMDAR-dependent synaptic plasticity in the hippocampus of ?2m(-/-)TAP(-/-)mice is accompanied by pervasive deficits in hippocampus-dependent memory, including contextual fear memory, object recognition memory, and social recognition memory. Thus normal MHC class I expression is essential for NMDAR-dependent hippocampal synaptic depression and hippocampus-dependent memory. These results suggest that changes in MHC class I expression could be an unexpected cause of disrupted synaptic plasticity and cognitive deficits in the aging, damaged, and diseased brain.

Nelson PA; Sage JR; Wood SC; Davenport CM; Anagnostaras SG; Boulanger LM

2013-01-01

210

Just another day in a woman's life? Part II: Nature and consistency of women's long-term memories of their first birth experiences.  

Science.gov (United States)

Twenty women who attended the author's natural childbirth classes between 1968 and 1974 were the informants in this study of long-term memories of their first childbirths. The data from each informant consisted of 1) a labor and birth questionnaire, including an open-ended account of her labor, written shortly after her baby was born; 2) a similar questionnaire and account written in 1988 and 1989; and 3) a transcribed interview during which her memories and perceptions were discussed and any discrepancies between the questionnaires were explored. The questionnaires were compared for consistency of recall, and the interviews consulted for further clarification. Specific memories were excerpted, compared, classified, tabulated, and summarized. Findings were that, years later, women's memories are generally accurate, and many are strikingly vivid, especially of onset of labor; rupture of the membranes; arrival at the hospital; actions of doctors, nurses, and partners; particular interventions; the birth; and first contact with the baby. Most memory lapses or confusion were minor. Evidence of a halo effect was observed as well. PMID:1388434

Simkin, P

1992-06-01

211

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.

2011-06-01

212

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)

Full Text Available Abstract in english 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 (more) 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.

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

2012-01-01

213

Changes in heart rate variability are associated with expression of short-term and long-term contextual and cued fear memories.  

Science.gov (United States)

Heart physiology is a highly useful indicator for measuring not only physical states, but also emotional changes in animals. Yet changes of heart rate variability during fear conditioning have not been systematically studied in mice. Here, we investigated changes in heart rate and heart rate variability in both short-term and long-term contextual and cued fear conditioning. We found that while fear conditioning could increase heart rate, the most significant change was the reduction in heart rate variability which could be further divided into two distinct stages: a highly rhythmic phase (stage-I) and a more variable phase (stage-II). We showed that the time duration of the stage-I rhythmic phase were sensitive enough to reflect the transition from short-term to long-term fear memories. Moreover, it could also detect fear extinction effect during the repeated tone recall. These results suggest that heart rate variability is a valuable physiological indicator for sensitively measuring the consolidation and expression of fear memories in mice. PMID:23667644

Liu, Jun; Wei, Wei; Kuang, Hui; Zhao, Fang; Tsien, Joe Z

2013-05-07

214

Changes in heart rate variability are associated with expression of short-term and long-term contextual and cued fear memories.  

UK PubMed Central (United Kingdom)

Heart physiology is a highly useful indicator for measuring not only physical states, but also emotional changes in animals. Yet changes of heart rate variability during fear conditioning have not been systematically studied in mice. Here, we investigated changes in heart rate and heart rate variability in both short-term and long-term contextual and cued fear conditioning. We found that while fear conditioning could increase heart rate, the most significant change was the reduction in heart rate variability which could be further divided into two distinct stages: a highly rhythmic phase (stage-I) and a more variable phase (stage-II). We showed that the time duration of the stage-I rhythmic phase were sensitive enough to reflect the transition from short-term to long-term fear memories. Moreover, it could also detect fear extinction effect during the repeated tone recall. These results suggest that heart rate variability is a valuable physiological indicator for sensitively measuring the consolidation and expression of fear memories in mice.

Liu J; Wei W; Kuang H; Zhao F; Tsien JZ

2013-01-01

215

Ambient visual information confers a context-specific, long-term benefit on memory for haptic scenes.  

UK PubMed Central (United Kingdom)

We investigated the effects of indirect, ambient visual information on haptic spatial memory. Using touch only, participants first learned an array of objects arranged in a scene and were subsequently tested on their recognition of that scene which was always hidden from view. During haptic scene exploration, participants could either see the surrounding room or were blindfolded. We found a benefit in haptic memory performance only when ambient visual information was available in the early stages of the task but not when participants were initially blindfolded. Specifically, when ambient visual information was available a benefit on performance was found in a subsequent block of trials during which the participant was blindfolded (Experiment 1), and persisted over a delay of one week (Experiment 2). However, we found that the benefit for ambient visual information did not transfer to a novel environment (Experiment 3). In Experiment 4 we further investigated the nature of the visual information that improved haptic memory and found that geometric information about a surrounding (virtual) room rather than isolated object landmarks, facilitated haptic scene memory. Our results suggest that vision improves haptic memory for scenes by providing an environment-centred, allocentric reference frame for representing object location through touch.

Pasqualotto A; Finucane CM; Newell FN

2013-09-01

216

The Ebb and Flow of Infant Attentional Preferences: Evidence for Long-Term Recognition Memory in 3-Month-Olds.  

Science.gov (United States)

Two experiments used paired-comparisons to investigate 3-month olds' recognition of dynamic visual events after various retention intervals. Results indicated a changing pattern of attentional preferences over time consistent with models of infant recognition memory in which novelty, familiarity, and null preferences are considered conjointly and…

Courage, Mary L.; Howe, Mark L.

1998-01-01

217

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Introduction:The hippocampus is one for the major centers of learning and memory. Role of the opioid system has been investigated and on the other hand receptors related to this system such as mu-opioid receptors (MOR) are extended in the hippocampus. In this study the effect of Naloxone administrat...

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

218

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

Directory of Open Access Journals (Sweden)

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

Wichian Sittiprapaporn; Chittin Chindaduangratn; Naiphinich Kotchabhakdi

2004-01-01

219

Consolidation of long-term memory by insulin in Lymnaea is not brought about by changing the number of insulin receptors.  

UK PubMed Central (United Kingdom)

The pond snail Lymnaea stagnalis learns taste aversion and consolidates it into long-term memory (LTM). This is referred to as conditioned taste aversion (CTA). The superfusion of molluscan insulin-related peptides (MIPs) over the isolated snail brain causes a long-term enhancement of synaptic input between the cerebral giant cell and the B1 buccal motor neuron. This enhancement is hypothesized to underlie CTA. The synaptic enhancement caused by the superfusion of MIPs can be blocked by the application of human insulin receptor antibody, which recognizes the extracellular domain of human insulin receptor and acts as an antagonist even for MIP receptors. An injection of the human insulin receptor antibody into the abdominal cavity of trained snails blocks the consolidation process leading to LTM, even though the snails acquire taste aversion. Here, we examined whether or not taste-aversion training changes the mRNA expression level of MIP receptor in the snail brain and found that it does not. This result, taken together with previous findings, suggest that the MIPs' effect on synaptic function in the snail brain is attributable to a change in the MIP concentration, and not to a change in the mRNA expression level of MIP receptor, which is thought to reflect the number of MIP receptors.

Hatakeyama D; Okuta A; Otsuka E; Lukowiak K; Ito E

2013-05-01

220

Consolidation of long-term memory by insulin in Lymnaea is not brought about by changing the number of insulin receptors.  

Science.gov (United States)

The pond snail Lymnaea stagnalis learns taste aversion and consolidates it into long-term memory (LTM). This is referred to as conditioned taste aversion (CTA). The superfusion of molluscan insulin-related peptides (MIPs) over the isolated snail brain causes a long-term enhancement of synaptic input between the cerebral giant cell and the B1 buccal motor neuron. This enhancement is hypothesized to underlie CTA. The synaptic enhancement caused by the superfusion of MIPs can be blocked by the application of human insulin receptor antibody, which recognizes the extracellular domain of human insulin receptor and acts as an antagonist even for MIP receptors. An injection of the human insulin receptor antibody into the abdominal cavity of trained snails blocks the consolidation process leading to LTM, even though the snails acquire taste aversion. Here, we examined whether or not taste-aversion training changes the mRNA expression level of MIP receptor in the snail brain and found that it does not. This result, taken together with previous findings, suggest that the MIPs' effect on synaptic function in the snail brain is attributable to a change in the MIP concentration, and not to a change in the mRNA expression level of MIP receptor, which is thought to reflect the number of MIP receptors. PMID:23710281

Hatakeyama, Dai; Okuta, Akiko; Otsuka, Emi; Lukowiak, Ken; Ito, Etsuro

2013-04-09

 
 
 
 
221

Long-term T cell memory to human leucocyte antigen-A2 supertype epitopes in humans vaccinated against smallpox.  

Science.gov (United States)

Identification of human leucocyte antigen (HLA) class I-restricted T cell epitopes is important to develop methods to track the evolution of T cell memory to new generation smallpox vaccines and allow comparison to older vaccinia virus preparations known to induce protection against smallpox. We evaluated the relative predictive values of four computational algorithms to identify candidate 9-mer HLA-A2 supertype epitopes that were confirmed to stimulate preferentially T cell interferon (IFN)-gamma responses by subjects last vaccinated with Dryvax 27-54 years previously. Six peptides encoded by I4L, G1L, A8R, I8R, D12L and H3L open reading frames that were identical for Vaccinia (Copenhagen), Variola major (Bangledesh 1975) and modified vaccinia Ankara strain preferentially stimulated IFN-gamma responses by healthy HLA-A2 supertype adults last given Dryvax 27-49 years earlier relative to remotely vaccinated non-HLA-A2 supertype and unvaccinated HLA-A2 supertype adults. Combining results from at least two computational algorithms that use different strategies to predict peptide binding to HLA-A2 supertype molecules was optimal for selection of candidate peptides that were confirmed to be epitopes by recall of T cell IFN-gamma responses. These data will facilitate evaluation of the immunogenicity of replication incompetent smallpox vaccines such as modified vaccinia Ankara and contribute to knowledge of poxvirus epitopes that are associated with long-lived T cell memory. PMID:17488297

Ostrout, N D; McHugh, M M; Tisch, D J; Moormann, A M; Brusic, V; Kazura, J W

2007-05-04

222

The n-butanolic extract of Opuntia ficus-indica var. saboten enhances long-term memory in the passive avoidance task in mice.  

UK PubMed Central (United Kingdom)

Opuntia ficus-indica var. saboten Makino (Cactaceae) is used to treat burns, edema, dyspepsia, and asthma in traditional medicine. The present study investigated the beneficial effects of the n-butanolic extract of O. ficus-indica var. saboten (BOF) on memory performance in mice and attempts to uncover the mechanisms underlying its action. Memory performance was assessed with the passive avoidance task, and western blotting and immunohistochemistry were used to measure changes in protein expression and cell survival. After the oral administration of BOF for 7 days, the latency time in the passive avoidance task was significantly increased relative to vehicle-treated controls (P<0.05). Western blotting revealed that the expression levels of brain-derived neurotrophic factor (BDNF), phosphorylated cAMP response element binding-protein (pCREB), and phosphorylated extracellular signal-regulated kinase (pERK) 1/2 were significantly increased in hippocampal tissue after 7 days of BOF administration (P<0.05). Doublecortin and 5-bromo-2-deoxyuridine immunostaining also revealed that BOF significantly enhanced the survival of immature neurons, but did not affect neuronal cell proliferation in the subgranular zone of the hippocampal dentate gyrus. These results suggest that the subchronic administration of BOF enhances long-term memory, and that this effect is partially mediated by ERK-CREB-BDNF signaling and the survival of immature neurons.

Kim JM; Kim DH; Park SJ; Park DH; Jung SY; Kim HJ; Lee YS; Jin C; Ryu JH

2010-08-01

223

Differences in gene expression in the hippocampus of aged rats are associated with better long-term memory performance in a passive avoidance test.  

UK PubMed Central (United Kingdom)

Microarray analysis was used to identify genes differentially expressed in the hippocampus of aged rats showing diverse long-term (3 and 6 h) spatial-associative memory performance in a single-trial inhibitory avoidance task. The transcription of 43 genes (including genes functionally linked to signal transduction, cell growth and differentiation, translation, energy metabolism, and nucleic acid processing) was significantly upregulated in good- versus bad-performing animals, whereas that of 18 genes (including genes functionally linked to transcription, cell growth and differentiation, apoptosis, and protein transport) was significantly downregulated in good- versus bad-performing animals. The differential expression of 14 of these genes was confirmed by real-time polymerase chain reaction.

Di Stefano G; Casoli T; Platano D; Fattoretti P; Balietti M; Giorgetti B; Bertoni-Freddari C; Lattanzio F; Aicardi G

2010-04-01

224

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)

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.

Elaheh Nooshinfar; Mostafa Rezaei-Tavirani; Soheila Khodakarim

2012-01-01

225

Long-term ?- and spontaneous fission measurement of a Rf/Db sample chemically prepared in a 48Ca on 243Am experiment  

International Nuclear Information System (INIS)

Results from long-term measurements of a chemically separated Db/Rf sample prepared from the products of a 48Ca on 243Am irradiation are presented. The sample with the highest spontaneous fission activity out of eight samples produced in the course of chemical experiments performed in 2004 was selected for these measurements. We conclude that there is no evidence for SF-decay originating from heavy actinide isotopes in this sample. Hence, it is appropriate to assign the SF-events observed in this experiment to decay products of 288115.

2009-01-01

226

Short-term and long-term memory deficits in handedness learning in mice with absent corpus callosum and reduced hippocampal commissure.  

UK PubMed Central (United Kingdom)

The corpus callosum (CC) and hippocampal commissure (HC) are major interhemispheric connections whose role in brain function and behaviors is fascinating and contentious. Paw preference of laboratory mice is a genetically regulated, adaptive behavior, continuously shaped by training and learning. We studied variation with training in paw-preference in mice of the 9XCA/WahBid ('9XCA') recombinant inbred strain, selected for complete absence of the CC and severely reduced HC. We measured sequences of paw choices in 9XCA mice in two training sessions in unbiased test chambers, separated by one-week. We compared them with sequences of paw choices in model non-learner mice that have random unbiased paw choices and with those of C57BL/6JBid ('C57BL/6J') mice that have normal interhemispheric connections and learn a paw preference. Positive autocorrelation between successive paw choices during each session and change in paw-preference bias between sessions indicate that 9XCA mice have weak, but not null, learning skills. We tested the effect of the forebrain commissural defect on paw-preference learning with the independent BTBR T+ tf/J ('BTBR') mouse strain that has a genetically identical, non-complementing commissural trait. BTBR has weak short-term and long-term memory skills, identical to 9XCA. The results provide strong evidence that CC and HC contribute in memory function and formation of paw-preference biases.

Ribeiro AS; Eales BA; Biddle FG

2013-05-01

227

Aquaporin-4 deficiency exacerbates brain oxidative damage and memory deficits induced by long-term ovarian hormone deprivation and D-galactose injection.  

UK PubMed Central (United Kingdom)

Astrocyte dysfunction is implicated in pathogenesis of certain neurological disorders including Alzheimer's disease (AD). A growing body of evidence indicates that water channel aquaporin-4 (AQP4) is a potential molecular target for the regulation astrocyte function. Recently, we reported that AQP4 expression was increased in the hippocampus of an AD mouse model established by long-term ovarian hormone deprivation combined with D-galactose (D-gal) exposure. However, pathophysiological roles and mechanisms of AQP4 up-regulation remain unclear. To address this issue, age-matched female wild-type and AQP4 null mice underwent ovariectomy, followed by D-gal administration for 8 wk. AQP4 null mice showed more severe brain oxidative stress, spatial learning and memory deficits, and basal forebrain cholinergic impairment than the wild-type controls. Notably, AQP4 null hippocampus contained more prominent amyloid-? production and loss of synapse-related proteins. These results suggested that ovariectomy and D-gal injection induced oxidative damage results in compensatory increases of AQP4 expression, and deficiency of AQP4 exacerbates brain oxidative stress and memory deficits. Therefore, regulation of astrocyte function by AQP4 may attenuate oxidative damage, offering a promising therapeutic strategy for AD.

Liu L; Lu Y; Kong H; Li L; Marshall C; Xiao M; Ding J; Gao J; Hu G

2011-02-01

228

Nicotinamide prevents the long-term effects of perinatal asphyxia on apoptosis, non-spatial working memory and anxiety in rats.  

UK PubMed Central (United Kingdom)

There is no established treatment for the long-term effects produced by perinatal asphyxia. Thus, we investigated the neuroprotection provided by nicotinamide against the effects elicited by perinatal asphyxia on hippocampus and behaviour observed at 30-90 days of age. Asphyxia was induced by immersing foetuses-containing uterine horns, removed from ready-to-deliver rats into a water bath at 37 degrees C for 20 min. Caesarean-delivered siblings were used as controls. Saline or nicotinamide (0.8 mmol/kg, i.p.) was administered to control and asphyxia-exposed animals 24, 48, and 72 h after birth. The animals were examined for morphological changes in hippocampus, focusing on delayed cell death and mossy fibre sprouting, and behaviour, focusing on cognitive behaviour and anxiety. At the age of 30-45 days, asphyxia-exposed rats displayed (1) increased apoptosis, assessed in whole hippocampus by nuclear Hoechst staining, and (2) increased mossy fibre sprouting, restricted to the stratum oriens of dorsal hippocampus, assessed by Timm's staining. Rats from the same cohorts displayed (3) deficits in non-spatial working memory, assessed by a novel object recognition task, and (4) increased anxiety, assessed by an elevated plus-maze test when examined at the age of 90 days. Nicotinamide prevented the effects elicited by perinatal asphyxia on apoptosis, working memory, and anxiety.

Morales P; Simola N; Bustamante D; Lisboa F; Fiedler J; Gebicke-Haerter PJ; Morelli M; Tasker RA; Herrera-Marschitz M

2010-04-01

229

A low bit-rate video coding approach using modified adaptive warping and long-term spatial memory  

Science.gov (United States)

In this paper, an H.264/AVC video coding strategy is introduced that employs a spatial-temporal video sequence representation in which video frames are coded at a low spatial sampling rate and reference I frames are coded at high spatial resolution. High spatial frequency information is re-synthesized at the receiver side using an adaptive motion estimation and warping method. The approach as presented is shown to improve coding quality for sequences with low to moderate motion.

Chen, Ying; Lettsome, Clyde; Smith, Mark; Delp, Edward J.

2007-01-01

230

Use of creatine containing preparation e.g. for improving memory, retentivity, long-term memory and for preventing mental fatigue condition, comprising e.g. Ginkgo biloba, ginseng and niacin  

UK PubMed Central (United Kingdom)

Use of a creatine containing preparation for improving memory, retentivity, long-term memory and for preventing mental fatigue conditions, comprising e.g. at least a further physiologically effective component of the series Ginkgo biloba, ginseng, taiga root, yam root, lecithin, choline, phosphatidylserine, dimethylamino ethanol, acetyl choline, acetyl-L-carnitine, glutathione, glutamine, cysteine, vitamin A, E, B1, B2, B6, B12, folic acid, pantothenic acid and/or zinc, is claimed. Use of a creatine-component containing preparation for improving memory, retentivity, long-term memory and for preventing mental fatigue conditions, comprising at least a further physiologically effective component of the series Ginkgo biloba, ginseng, taiga root, yam root, lecithin, choline, phosphatidylserine, dimethylamino ethanol, acetyl choline, acetyl-L-carnitine, glutathione, glutamine, cysteine, vitamin A, E, B1, B2, B6, B12, E, niacin, biotin, folic acid, pantothenic acid, zinc, manganese, selenium, magnesium, coenzyme Q10, glucose, colostrum, synephrine, octopamine, caffeine, theophylline, alpha -linolenic acid, eicosapentaenoic acid, omega-3-fatty acid, piracetam, aniracetam, memantine, pyritinol, galantamine, vinpocetin, pangamic acid and/or optionally organic or inorganic salts and/or optionally esters, is claimed. - ACTIVITY : Nootropic CNS-Gen Cerebroprotective. - MECHANISM OF ACTION : None given.

GASTNER THOMAS; SELZER FRAUKE; KRIMMER HANS-PETER; HAMMER BENEDIKT

231

Cytokines induced by long-term potentiation (LTP) recording: a potential explanation for the lack of correspondence between learning/memory performance and LTP.  

UK PubMed Central (United Kingdom)

The relationship between learning/memory performance and long-term potentiation (LTP) induction is ambiguous. Although a large body of data supports a strong correspondence between learning/memory performance and LTP, many studies have also provided evidence to the contrary. In this study, we found that 2-month-old senescence-accelerated mice/prone 8 (SAMP8 mice) displayed both impaired performance in a Morris Water Maze (MWM) and enhanced LTP compared to senescence-accelerated mice/resistance 1 (SAMR1). BALB/c mice challenged with Complete Freund's Adjuvant (CFA) performed better in the shuttle-box test but displayed impaired LTP compared to intact animals. It is interesting that BALB/c mice challenged with Incomplete Freund's Adjuvant (IFA) performed better than intact animals, with no LTP impairment. Cytokine analysis showed no significant differences between the interleukin-6 (IL-6), interleukin-10 (IL-10) or TNF-? content in the intact hippocampal tissues of either the SAMR1 and SAMP8 mice or the immune-challenged BALB/c and intact animals. Further analysis demonstrated that the increase in cytokine content was higher in the hippocampal tissues used for LTP recording in the SAMR1 and CFA-challenged animals compared to the SAMP8 and intact BALB/c mice. A correlation analysis demonstrated that pro-inflammatory cytokines (IL-6 and TNF-?) displayed a negative correlation with LTP, while an anti-inflammatory cytokine (IL-10) displayed a positive correlation with LTP. These results suggest that pro-inflammatory cytokines induced by LTP manipulation in experiments (e.g., via tissue injury caused by electrode insertion) may be one of the factors contributing to the observed lack of correspondence between memory/learning ability and LTP.

Huang Y; Hu Z; Liu G; Zhou W; Zhang Y

2013-02-01

232

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

International Nuclear Information System (INIS)

The Argonne team has gathered available data on monitoring wells and measured hydraulic heads from the Argonne 317/319 site and sent it to UIUC. Xiaodong Li, a research assistant supported by the project, has reviewed the data and has fit initial spatiotemporal statistical models to it. Another research assistant, Yonas Demissie, has completed generation of the artificial data that will be used for model development and testing. In order to generate the artificial data a detailed groundwater flow and contaminant transport model was developed based upon characteristics of the 317/319 site. The model covers a multi-year time horizon that includes both before and after planting of the trees. As described in the proposal, the artificial data is created by adding ''measurement'' error to the ''true'' value from the numerical model. To date, only simple white noise error models have been considered. He is now reviewing the literature and beginning to develop a hierarchical modeling approach for the artificial data. Abhishek Singh, a third research assistant supported by the project, is implementing learning models for learning users preferences in an interactive genetic algorithm for solving the inverse problem. Meghna Babbar, the fourth research assistant supported by the project, has been improving the user interface for the interactive genetic algorithm and preparing a long-term monitoring design problem for testing the approach. Gayathri Gopalakrishnan, the last research assistant who is partially supported by the project, has collected substantial data from the 317/319 phytoremediation site at Argonne and has begun learning approaches for modeling these data.

2004-01-01

233

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

Energy Technology Data Exchange (ETDEWEB)

The Argonne team has gathered available data on monitoring wells and measured hydraulic heads from the Argonne 317/319 site and sent it to UIUC. Xiaodong Li, a research assistant supported by the project, has reviewed the data and has fit initial spatiotemporal statistical models to it. Another research assistant, Yonas Demissie, has completed generation of the artificial data that will be used for model development and testing. In order to generate the artificial data a detailed groundwater flow and contaminant transport model was developed based upon characteristics of the 317/319 site. The model covers a multi-year time horizon that includes both before and after planting of the trees. As described in the proposal, the artificial data is created by adding ''measurement'' error to the ''true'' value from the numerical model. To date, only simple white noise error models have been considered. He is now reviewing the literature and beginning to develop a hierarchical modeling approach for the artificial data. Abhishek Singh, a third research assistant supported by the project, is implementing learning models for learning users preferences in an interactive genetic algorithm for solving the inverse problem. Meghna Babbar, the fourth research assistant supported by the project, has been improving the user interface for the interactive genetic algorithm and preparing a long-term monitoring design problem for testing the approach. Gayathri Gopalakrishnan, the last research assistant who is partially supported by the project, has collected substantial data from the 317/319 phytoremediation site at Argonne and has begun learning approaches for modeling these data.

Minsker, Barbara

2004-12-01

234

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

UK PubMed Central (United Kingdom)

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.

Reverte I; Klein AB; Domingo JL; Colomina MT

2013-08-01

235

IL-1RA blocks E. coli-induced suppression of Arc and long-term memory in aged F344 x BN F1 rats  

Science.gov (United States)

In normal aging, a peripheral immune challenge induces a sensitized and protracted neuroinflammatory response in parallel with long-term memory (LTM) impairments. Proinflammatory mediators of neuroinflammation impair LTM, synaptic plasticity and LTP. The immediate early gene Arc is considered a critical protein regulating LTM and synaptic plasticity. The present investigation examined whether 1) a peripheral E. coli infection suppresses hippocampal Arc expression, and 2) central proinflammatory cytokines (IL-1? and IL-6) mediate the effects of peripheral E. coli infection on Arc and LTM. In 24 mo F344 × BN F1 rats, E. coli infection suppressed basal Arc gene expression as well as contextual fear conditioning-induced Arc expression. E. coli treatment failed to alter either basal or conditioning-induced c-Fos expression. At 24 h post-infection, intracisterna magna (ICM) treatment with the anti-inflammatory cytokine IL-1RA blocked the E. coli-induced suppression of hippocampal Arc and increases in IL-6 protein. At 4 d post-infection, IL-1RA blocked the E. coli-induced LTM impairments and increases in IL-6 protein. The present results suggest that central proinflammatory cytokines play a salient role in the suppression of Arc and impairments of LTM by a peripheral immune challenge in older animals.

Frank, Matthew G.; Barrientos, Ruth M.; Hein, Amy M.; Biedenkapp, Joseph C.; Watkins, Linda R.; Maier, Steven F.

2009-01-01

236

Robust Recall and Long-Term Memory T-Cell Responses Induced by Prime-Boost Regimens with Heterologous Live Viral Vectors Expressing Human Immunodeficiency Virus Type 1 Gag and Env Proteins  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We investigated long-term memory and recall cellular immune responses to human immunodeficiency virus type 1 (HIV-1) Env and Gag proteins elicited by recombinant vesicular stomatitis viruses (VSVs) expressing Env and Gag. More than 7 months after a single vaccination with VSV-Env, ?6% of CD8+ spleno...

Haglund, Karl; Leiner, Ingrid; Kerksiek, Kristen; Buonocore, Linda; Pamer, Eric; Rose, John K.

237

Long-term collections  

CERN Multimedia

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

Collectes à long terme

2007-01-01

238

Long Term Ecological Resources  

Science.gov (United States)

Students analyze data on temperature and precipitation collected from 26 different Long Term Ecological Research sites and compare them with annual net primary productivity. The students then form an ecological rule to explain their results.

Cooper, Scott

239

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

CERN Multimedia

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

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

2012-01-01

240

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

Directory of Open Access Journals (Sweden)

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

Bråve Andreas; Gudmundsdotter Lindvi; Gasteiger Georg; Hallermalm Kristian; Kastenmuller Wolfgang; Rollman Erik; Boberg Andreas; Engström Gunnel; Reiland Sven; Cosma Antonio; Drexler Ingo; Hinkula Jorma; Wahren Britta; Erfle Volker

2007-01-01

 
 
 
 
241

Protein kinase M maintains long-term sensitization and long-term facilitation in aplysia.  

UK PubMed Central (United Kingdom)

How the brain maintains long-term memories is one of the major outstanding questions in modern neuroscience. Evidence from mammalian studies indicates that activity of a protein kinase C (PKC) isoform, protein kinase M? (PKM?), plays a critical role in the maintenance of long-term memory. But the range of memories whose persistence depends on PKM?, and the mechanisms that underlie the effect of PKM? on long-term memory, remain obscure. Recently, a PKM isoform, known as PKM Apl III, was cloned from the nervous system of Aplysia. Here, we tested whether PKM Apl III plays a critical role in long-term memory maintenance in Aplysia. Intrahemocoel injections of the pseudosubstrate inhibitory peptide ZIP (? inhibitory peptide) or the PKC inhibitor chelerythrine erased the memory for long-term sensitization (LTS) of the siphon-withdrawal reflex (SWR) as late as 7 d after training. In addition, both PKM inhibitors disrupted the maintenance of long-term (? 24 h) facilitation (LTF) of the sensorimotor synapse, a form of synaptic plasticity previously shown to mediate LTS of the SWR. Together with previous results (Bougie et al., 2009), our results support the idea that long-term memory in Aplysia is maintained via a positive-feedback loop involving PKM Apl III-dependent protein phosphorylation. The present data extend the known role of PKM in memory maintenance to a simple and well studied type of long-term learning. Furthermore, the demonstration that PKM activity underlies the persistence of LTF of the Aplysia sensorimotor synapse, a form of synaptic plasticity amenable to rigorous cellular and molecular analyses, should facilitate efforts to understand how PKM activity maintains memory.

Cai D; Pearce K; Chen S; Glanzman DL

2011-04-01

242

Long-Term Collections  

CERN Document Server

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

Comité des collectes à long terme

2011-01-01

243

Long Term Quadrotor Stabilization.  

Science.gov (United States)

The work of this thesis focuses on the IMU and getting the best performance possible out of the IMU to achieve better long term stability and a better navigation solution. This is done in two ways. First, the IMU accelerometer output is examined to determ...

N. Hamilton

2011-01-01

244

Long-term medical outcomes in survivors of extra-ocular retinoblastoma: the Memorial Sloan-Kettering Cancer Center (MSKCC) experience.  

UK PubMed Central (United Kingdom)

BACKGROUND: Data on long-term outcomes of survivors of extra-ocular retinoblastoma are lacking. The authors sought to provide the first report characterizing long-term outcomes among survivors of extra-ocular retinoblastoma. PROCEDURE: Retrospective analysis of long-term medical outcomes in 19 survivors of extra-ocular retinoblastoma treated between 1992 and 2009. Severity of outcomes was graded using Common Terminology Criteria for Adverse Events. All patients received intensive multimodality therapy for their extra-ocular disease after management of their primary intra-ocular disease, including conventional chemotherapy (n = 19, 100%), radiotherapy (n = 15, 69%), and/or high-dose chemotherapy with autologous stem cell transplant (n = 17, 89%). RESULTS: The median follow-up was 7.8 years from diagnosis of extra-ocular retinoblastoma (range 2-17.8 years). The most common long-term non-visual outcomes were hearing loss (n = 15, 79%), short stature (n = 7, 37%), and secondary malignancies [SMN] (n = 6, 31%). Sixty-eight percent of survivors exhibited ?2 non-visual long-term outcomes of any grade. Except short stature, which was not graded for severity, Grade 3-4 outcomes were limited to: ototoxicity (n = 8; n = 4 require hearing aids), SMNs (n = 6), and unequal limb length (n = 1). Five patients who developed SMNs carried a known RB1 mutation. SMNs developed at a median of 11.1 years after initial diagnosis; two patients died of their SMN. Long-term cardiac, pulmonary, hepatobiliary, or renal conditions were not identified in any survivors. CONCLUSION: Long-term outcomes are commonly seen in extra-ocular retinoblastoma survivors but the majority are mild-moderate in their severity. Longer comprehensive follow-up is needed to fully assess treatment-related outcomes but the information collected to date may affect management decisions for children with extra-ocular disease.

Friedman DN; Sklar CA; Oeffinger KC; Kernan NA; Khakoo Y; Marr BP; Wolden SL; Abramson DH; Dunkel IJ

2013-04-01

245

Direct quantification of cell-associated HIV DNA in isolated rectal and blood memory CD4 T cells revealed their similar and low infection levels in long-term treated HIV-infected patients.  

UK PubMed Central (United Kingdom)

To evaluate the contribution of CD4 T cells from blood and gut compartments to the HIV-1 reservoir, we directly quantified cell-associated HIV DNA in isolated rectal (R-) and peripheral blood (PB-) memory CD4 T cells from 11 successfully long-term treated patients. Proportion of activated (CD25(+); CD69(+); and HLA-DR(+)) and CCR5 expressing CD4 T cells were markedly higher in rectal tissue compared with blood. However, HIV-1 infection levels of R- and PB-memory CD4 T cells did not significantly differ (medians: 4000 and 2100 copies per million cells) after effective long-term viral control, suggesting that each of these 2 compartments does not contribute in a similar fashion to the total HIV reservoir.

Descours B; Lambert-Niclot S; Mory B; Samri A; Charlotte F; Peytavin G; Tubiana R; Papagno L; Bacchus C; Lecardonnel F; Katlama C; Autran B; Marcelin AG; Valantin MA; Carcelain G

2013-03-01

246

Role of the Phosphoinositide 3-Kinase-Akt-Mammalian Target of the Rapamycin Signaling Pathway in Long-Term Potentiation and Trace Fear Conditioning Memory in Rat Medial Prefrontal Cortex  

Science.gov (United States)

Phosphatidylinositol 3-kinase (PI3K) and its downstream targets, including Akt (also known as protein kinase B, PKB), mammalian target of rapamycin (mTOR), the 70-kDa ribosomal S6 kinase (p70S6k), and the eukaryotic initiation factor 4E (eIF4E)-binding protein 1 (4E-BP1), may play important roles in long-term synaptic plasticity and memory in many…

Sui, Li; Wang, Jing; Li, Bao-Ming

2008-01-01

247

Comparison of use of vaginal HPV self-sampling and offering flexible appointments as strategies to reach long-term non-attending women in organized cervical screening.  

UK PubMed Central (United Kingdom)

BACKGROUND: Many cervical cancers occur among women who have not attended cervical screening. Strategies to reach non-attending women may improve the effectiveness of cervical screening programmes. OBJECTIVE: To compare the responses among long-term non-attending women to either (i) HPV-testing of a self-collected vaginal sample, or (ii) cytological screening with a flexible no-fee appointment for sampling at an outpatient clinic. STUDY DESIGN: Among the 242,000 women aged 32-65 years in Southern Sweden, we identified 28,635 women who had not had any cervical smears taken for >9 years. We randomized 1000 women to invitation to HPV self-sampling, and 500 women to flexible outpatient clinic appointments. Responding women received a questionnaire about their reasons for previous non-attendance. RESULTS: The response rate to HPV self-sampling was three times higher than the flexible outpatient clinic invitations (147/1000 women (14.7%) compared to 21/500 (4.2%) p<0.0001). High-risk (hr)-HPV was found in 10/147 self-sampled women (6.9%). 7/10 hr-HPV-positive women attended colposcopy, but no HSIL was found. Among the clinic-sampled women, 2/21 had hr-HPV and 1/21 had HSIL. Reasons for not attending were "uncomfortable with vaginal examination", "feel healthy", "lack of time" and "experience of unfriendly health workers". CONCLUSIONS: Although the response rate was low for both interventions, the invitation to vaginal HPV self-sampling was more effective for increasing the coverage of the screening programme. The fact that "uncomfortable with vaginal examination" was the most common reason for non-attending suggests that self-sampling could be further explored as a strategy to increase the coverage of cervical screening programmes.

Darlin L; Borgfeldt C; Forslund O; Hénic E; Hortlund M; Dillner J; Kannisto P

2013-09-01

248

Long-term data archiving  

Energy Technology Data Exchange (ETDEWEB)

Long term data archiving has much value for chemists, not only to retain access to research and product development records, but also to enable new developments and new discoveries. There are some recent regulatory requirements (e.g., FDA 21 CFR Part 11), but good science and good business both benefit regardless. A particular example of the benefits of and need for long term data archiving is the management of data from spectroscopic laboratory instruments. The sheer amount of spectroscopic data is increasing at a scary rate, and the pressures to archive come from the expense to create the data (or recreate it if it is lost) as well as its high information content. The goal of long-term data archiving is to save and organize instrument data files as well as any needed meta data (such as sample ID, LIMS information, operator, date, time, instrument conditions, sample type, excitation details, environmental parameters, etc.). This editorial explores the issues involved in long-term data archiving using the example of Raman spectral databases. There are at present several such databases, including common data format libraries and proprietary libraries. However, such databases and libraries should ultimately satisfy stringent criteria for long term data archiving, including readability for long times into the future, robustness to changes in computer hardware and operating systems, and use of public domain data formats. The latter criterion implies the data format should be platform independent and the tools to create the data format should be easily and publicly obtainable or developable. Several examples of attempts at spectral libraries exist, such as the ASTM ANDI format, and the JCAMP-DX format. On the other hand, proprietary library spectra can be exchanged and manipulated using proprietary tools. As the above examples have deficiencies according to the three long term data archiving criteria, Extensible Markup Language (XML; a product of the World Wide Web Consortium, an independent standards body) as a new data interchange tool is being investigated and implemented. In order to facilitate data archiving, Raman data needs calibration as well as some other kinds of data treatment. Figure 1 illustrates schematically the present situation for Raman data calibration in the world-wide Raman spectroscopy community, and presents some of the terminology used.

Moore, David Steven [Los Alamos National Laboratory

2009-01-01

249

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

Science.gov (United States)

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

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

2011-12-01

250

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

UK PubMed Central (United Kingdom)

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

Romeu B; Lastre M; García L; Cedré B; Mandariote A; Fariñas M; Oliva R; Pérez O

2013-05-01

251

Exploitation of FTA cartridges for the sampling, long-term storage and DNA-based analyses of plant-parasitic nematodes.  

UK PubMed Central (United Kingdom)

The use of DNA-based analyses in molecular plant nematology research has dramatically increased over recent decades. Therefore, the development and adaptation of simple, robust and cost-effective DNA purification procedures are required to address these contemporary challenges. The solid phase-based approach developed by Flinders Technology Associates (FTA) has been shown to be a powerful technology for the preparation of DNA from different biological materials, including blood, saliva, plant tissues, and various human and plant microbial pathogens. In this work, we demonstrate, for the first time, that this FTA-based technology is a valuable, low-cost and time-saving approach for the sampling, long-term archiving and molecular analysis of plant-parasitic nematodes. Despite the complex structure and anatomical organization of the multicellular bodies of nematodes, we report the successful and reliable DNA-based analysis of nematode high-copy and low-copy genes using the FTA technology. This was achieved by applying nematodes to the FTA cards either in the form of a suspension of individuals, as intact or pestle-crushed nematodes, or by the direct mechanical printing of nematode-infested plant tissues. We further demonstrate that the FTA method is also suitable for the so-called "one-nematode-assay", in which the target DNA is typically analyzed from a single individual nematode. More surprisingly, a time-course experiment showed that nematode DNA can be detected specifically in the FTA-captured samples many years after initial sampling occurs. Collectively, our data clearly demonstrate the applicability and the robustness of this FTA-based approach for molecular research and diagnostics concerning phytonematodes; this research includes economically important species, such as the stem nematode (Ditylenchus dipsaci), the sugar beet nematode (Heterodera schachtii) and the Northern root-knot nematode (Meloidogyne hapla).

Marek M; Zouhar M; Douda O; Manasova M; Rysanek P

2013-10-01

252

The Neurobiological Basis of Cognition: Identification by Multi-Input, Multioutput Nonlinear Dynamic Modeling: A method is proposed for measuring and modeling human long-term memory formation by mathematical analysis and computer simulation of nerve-cell dynamics.  

UK PubMed Central (United Kingdom)

The successful development of neural prostheses requires an understanding of the neurobiological bases of cognitive processes, i.e., how the collective activity of populations of neurons results in a higher level process not predictable based on knowledge of the individual neurons and/or synapses alone. We have been studying and applying novel methods for representing nonlinear transformations of multiple spike train inputs (multiple time series of pulse train inputs) produced by synaptic and field interactions among multiple subclasses of neurons arrayed in multiple layers of incompletely connected units. We have been applying our methods to study of the hippocampus, a cortical brain structure that has been demonstrated, in humans and in animals, to perform the cognitive function of encoding new long-term (declarative) memories. Without their hippocampi, animals and humans retain a short-term memory (memory lasting approximately 1 min), and long-term memory for information learned prior to loss of hippocampal function. Results of more than 20 years of studies have demonstrated that both individual hippocampal neurons, and populations of hippocampal cells, e.g., the neurons comprising one of the three principal subsystems of the hippocampus, induce strong, higher order, nonlinear transformations of hippocampal inputs into hippocampal outputs. For one synaptic input or for a population of synchronously active synaptic inputs, such a transformation is represented by a sequence of action potential inputs being changed into a different sequence of action potential outputs. In other words, an incoming temporal pattern is transformed into a different, outgoing temporal pattern. For multiple, asynchronous synaptic inputs, such a transformation is represented by a spatiotemporal pattern of action potential inputs being changed into a different spatiotemporal pattern of action potential outputs. Our primary thesis is that the encoding of short-term memories into new, long-term memories represents the collective set of nonlinearities induced by the three or four principal subsystems of the hippocampus, i.e., entorhinal cortex-to-dentate gyrus, dentate gyrus-to-CA3 pyramidal cell region, CA3-to-CA1 pyramidal cell region, and CA1-to-subicular cortex. This hypothesis will be supported by studies using in vivo hippocampal multineuron recordings from animals performing memory tasks that require hippocampal function. The implications for this hypothesis will be discussed in the context of "cognitive prostheses"-neural prostheses for cortical brain regions believed to support cognitive functions, and that often are subject to damage due to stroke, epilepsy, dementia, and closed head trauma.

Berger TW; Song D; Chan RH; Marmarelis VZ

2010-03-01

253

Transcranial focal electrical stimulation via tripolar concentric ring electrodes does not modify the short- and long-term memory formation in rats evaluated in the novel object recognition test.  

UK PubMed Central (United Kingdom)

Noninvasive transcranial focal electrical stimulation (TFS) via tripolar concentric ring electrodes (TCREs) has been under development as an alternative/complementary therapy for seizure control. Transcranial focal electrical stimulation has shown efficacy in attenuating penicillin-, pilocarpine-, and pentylenetetrazole-induced acute seizures in rat models. This study evaluated the effects of TFS via TCREs on the memory formation of healthy rats as a safety test of TFS. Short- and long-term memory formation was tested after the application of TFS using the novel object recognition (NOR) test. The following independent groups were used: naïve, control (without TFS), and TFS (treated). The naïve, control, and stimulated groups spent more time investigating the new object than the familiar one during the test phase. Transcranial focal electrical stimulation via TCREs given once does not modify the short- and long-term memory formation in rats in the NOR test. Results provide an important step towards a better understanding for the safe usage of TFS via TCREs.

Rogel-Salazar G; Luna-Munguía H; Stevens KE; Besio WG

2013-04-01

254

LONG TERM COLLECTIONS  

CERN Multimedia

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

STAFF ASSOCIATION

2010-01-01

255

Self-referential processing is distinct from semantic elaboration: Evidence from long-term memory effects in a patient with amnesia and semantic impairments.  

UK PubMed Central (United Kingdom)

We report data demonstrating that self-referential encoding facilitates memory performance in the absence of effects of semantic elaboration in a severely amnesic patient also suffering semantic problems. In Part 1, the patient, GA, was trained to associate items with the self or a familiar other during the encoding phase of a memory task (self-ownership decisions in Experiment 1 and self-evaluation decisions in Experiment 2). Tests of memory showed a consistent self-reference advantage, relative to a condition where the reference was another person in both experiments. The pattern of the self-reference advantage was similar to that in healthy controls. In Part 2 we demonstrate that GA showed minimal effects of semantic elaboration on memory for items he semantically classified, compared with items subject to physical size decisions; in contrast, healthy controls demonstrated enhanced memory performance after semantic relative to physical encoding. The results indicate that self-referential encoding, not semantic elaboration, improves memory in amnesia. Self-referential processing may provide a unique scaffold to help improve learning in amnesic cases.

Sui J; Humphreys GW

2013-08-01

256

Long-term testing  

Energy Technology Data Exchange (ETDEWEB)

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

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

1994-12-31

257

Long-term testing  

Science.gov (United States)

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

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

258

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

Directory of Open Access Journals (Sweden)

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.

Frank J.E.; Tomaz C.

2000-01-01

259

Modes of long-term coping with trauma memories: relative use and associations with personality among Vietnam veterans with chronic PTSD.  

UK PubMed Central (United Kingdom)

Little is known about how individuals who develop chronic posttraumatic stress disorder (PTSD) cope with recurring trauma memories, or how enduring personality characteristics influence such coping. Focusing on 110 hospitalized Vietnam combat veterans with chronic PTSD, this exploratory study assessed the relative frequency of using eight ways of coping with war memories, and associations between relative use of these strategies and eight dysfunctional personality styles. As a secondary issue, associations between coping strategies, combat exposure, and PTSD severity were also examined. Consistent with prior findings, these veterans predominantly used emotion-focused and avoidant strategies to cope with war memories. Differing personality styles and relative use or nonuse of particular coping strategies were also associated in psychologically coherent ways. These preliminary findings are discussed in relation to methodologic and future research issues.

Hyer L; McCranie EW; Boudewyns PA; Sperr E

1996-04-01

260

Modes of long-term coping with trauma memories: relative use and associations with personality among Vietnam veterans with chronic PTSD.  

Science.gov (United States)

Little is known about how individuals who develop chronic posttraumatic stress disorder (PTSD) cope with recurring trauma memories, or how enduring personality characteristics influence such coping. Focusing on 110 hospitalized Vietnam combat veterans with chronic PTSD, this exploratory study assessed the relative frequency of using eight ways of coping with war memories, and associations between relative use of these strategies and eight dysfunctional personality styles. As a secondary issue, associations between coping strategies, combat exposure, and PTSD severity were also examined. Consistent with prior findings, these veterans predominantly used emotion-focused and avoidant strategies to cope with war memories. Differing personality styles and relative use or nonuse of particular coping strategies were also associated in psychologically coherent ways. These preliminary findings are discussed in relation to methodologic and future research issues. PMID:8731549

Hyer, L; McCranie, E W; Boudewyns, P A; Sperr, E

1996-04-01

 
 
 
 
261

Study of avidity of antigen-specific antibody as a means of understanding development of long-term immunological memory after Vibrio cholerae O1 infection.  

UK PubMed Central (United Kingdom)

The avidity of antibodies to specific antigens and the relationship of avidity to memory B cell responses to these antigens have not been studied in patients with cholera or those receiving oral cholera vaccines. We measured the avidity of antibodies to cholera toxin B subunit (CTB) and Vibrio cholerae O1 lipopolysaccharide (LPS) in Bangladeshi adult cholera patients (n = 30), as well as vaccinees (n = 30) after administration of two doses of a killed oral cholera vaccine. We assessed antibody and memory B cell responses at the acute stage in patients or prior to vaccination in vaccinees and then in follow-up over a year. Both patients and vaccinees mounted CTB-specific IgG and IgA antibodies of high avidity. Patients showed longer persistence of these antibodies than vaccinees, with persistence lasting in patients up to day 270 to 360. The avidity of LPS-specific IgG and IgA antibodies in patients remained elevated up to 180 days of follow-up. Vaccinees mounted highly avid LPS-specific antibodies at day 17 (3 days after the second dose of vaccine), but the avidity waned rapidly to baseline by 30 days. We examined the correlation between antigen-specific memory B cell responses and avidity indices for both antigens. We found that numbers of CTB- and LPS-specific memory B cells significantly correlated with the avidity indices of the corresponding antibodies (P < 0.05; Spearman's ? = 0.28 to 0.45). These findings suggest that antibody avidity after infection and immunization is a good correlate of the development and maintenance of memory B cell responses to Vibrio cholerae O1 antigens.

Alam MM; Arifuzzaman M; Ahmad SM; Hosen MI; Rahman MA; Rashu R; Sheikh A; Ryan ET; Calderwood SB; Qadri F

2013-01-01

262

The elevated T-maze task as an animal model to simultaneously investigate the effects of drugs on long-term memory and anxiety in mice.  

UK PubMed Central (United Kingdom)

The elevated T-maze (ETM) is an apparatus derived from the elevated plus-maze test, which is used to evaluate anxiety. Because anxiety is a biasing factor in models of memory, this study proposed the ETM as a task for the simultaneous assessment of memory and anxiety in mice. The ETM consists of one enclosed and two open arms. The procedure is based on the avoidance of open spaces learned during training session, in which mice were exposed to the enclosed arm as many times as needed to stay 300s. In the test session, memory is assessed by re-exposing the mouse to the enclosed arm and the latency to enter an open arm was recorded. The anxiolytic diazepam (DZP; 1 or 2mg/kg) and the amnestic biperiden (BPR; 0.5, 1 or 3mg/kg) were injected at three distinct times: pre-training, post-training, and pre-test. Pre-training administration of BPR 1 and DZP 2 increased the number of trials needed to reach the avoidance criterion, suggesting a passive avoidance learning impairment. However, BPR induced hyperlocomotion, which could bias the interpretation of any BPR-induced effects during the training session. Pre-training injection of BPR did not affect the spontaneous increase in the latency to enter an open arm between trials, while DZP reduced latencies in the first three trials suggesting anxiolysis. In the test session, pre-training injection of BPR 1 and DZP 2 reduced latencies to enter an open arm, indicating memory impairment. Post-training and pre-test injection of DZP or BPR did not affect memory. In conclusion, the proposed ETM task is practical for the detection of the anxiolytic and amnesic effects of drugs.

Asth L; Lobão-Soares B; André E; Soares Vde P; Gavioli EC

2012-04-01

263

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

Directory of Open Access Journals (Sweden)

Full Text Available Tianeptine is a well-described antidepressant which has been shown to prevent stress from producing deleterious effects on brain structure and function. Preclinical studies have shown that tianeptine blocks stress-induced alterations of neuronal morphology and synaptic plasticity. Moreover, tianeptine prevents stress from impairing learning and memory, and, importantly, demonstrates memory-enhancing properties in the absence of stress. Recent research has indicated that tianeptine works by normalizing glutamatergic neurotransmission, a mechanism of action that may underlie its effectiveness as an antidepressant. These findings emphasize the value in focusing on the mechanisms of action of tianeptine, and specifically, the glutamatergic system, in the development of novel pharmacotherapeutic strategies in the treatment of depression.

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

2010-01-01

264

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 ketamine anesthesia (70 mg·kg-1), daily for seven days. Nine weeks after birth, the Morris water maze was used to test the ability of learning and spatial localization memory on the rats. Following behavioral testing, animals’ hippocampi were removed for Western blot and electron microscopic examination. Results: In the Morris water maze test, compared with controls, the escape latency in groups exposed to ketamine or ketamine plus the ethanol vehicle were significantly prolonged (P P P 0.05), while there was no significant difference between control groups and animals treated with Ro 20-1724 following ketamine exposure (P > 0.05). Electron microscopy demonstrated degenerative changes in hippocampal neurons of animals repetitively exposed to 70 mg·kg-1 Ketamine, which was ameliorated by Ro 20-1724 (0.5 mg·kg-1). Conclusion: The PDE-4 inhibitor Ro 20-1724 (0.5 mg·kg-1

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

2013-01-01

265

Memória de longo prazo modulada pela memória de curto prazo Memoria a largo plazo modulada por la memoria a corto plazo Long term memory modulated by short term memory  

Directory of Open Access Journals (Sweden)

Full Text Available Quando um estímulo ocorre aleatoriamente à esquerda ou à direita, a resposta é mais rápida quando estímulo e resposta estão no mesmo lado (condição compatível) do que em lados opostos (condição incompatível). Na tarefa de Simon, embora a resposta seja selecionada pela forma (ou cor) do estímulo, a posição deste influencia o Tempo de Reação Manual (TRM). O efeito Simon corresponde à diferença entre as médias dos TRMs nas duas condições (incompatível e compatível). Neste trabalho, estudamos como uma tarefa prévia de compatibilidade realizada com um dedo indicador modula o efeito Simon. Vinte e oito voluntários realizaram uma tarefa de compatibilidade seguida pela tarefa de Simon. No grupo compatível (14 voluntários), encontramos um efeito Simon de 24 ms. No incompatível (14 voluntários), ocorreu um efeito Simon inverso de -16 ms. Estes resultados mostram uma modulação da memória de longo prazo por uma tarefa envolvendo a memória de curto prazo.Cuando un estimulo ocurre aleatoriamente a la izquierda o a la derecha, la respuesta es más rápida cuando el estimulo y la respuesta están del mismo lado (condición compatible), de que cuando están en lados opuestos (condición incompatible). En la prueba de Simon, el color o la forma del estímulo determina la respuesta, pero éste es más rápido cuando hay una correlación espacial entre el estímulo y la respuesta. En este trabajo, estudiamos la modulación del efecto Simon por la tarea de la compatibilidad espacial en la cual uno dedo índice respondió. Veintiocho voluntarios realizaron la prueba de compatibilidad (14 la compatible y 14 la incompatible). Después el voluntario realizó la prueba de Simon. En el grupo compatible, encontramos efecto de Simon de 21 ms. Sin embargo, en el grupo incompatibles, ocurrió un efecto de Simon inverso de -16 ms. Estos resultados demuestran una modulación de la memoria a largo plazo por la memoria a corto plazo.When a stimulus randomly occurs at left or right, the response is faster when stimulus and response are on the same side (compatible condition) than on opposite sides (incompatible condition). In the Simon task, color or shape determines the correct response but it is faster when there is correspondence between stimulus and response key positions. In this research, we studied the Simon effect modulation through a previous spatial compatibility task in which just one index finger presses the keys. Twenty-eight volunteers run compatibility tasks (14 compatible and 14 incompatible). Then, they performed a Simon task in which the correct response was selected by shape. A Simon effect of 24 ms was found in the compatible group. An inverse Simon effect of -16 ms occurred in the incompatible group. These results show long-term memory modulation by task involving short-term memory.

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

2008-01-01

266

The ups and downs of repetition: Modulation of the perirhinal cortex by conceptual repetition predicts priming and long-term memory.  

UK PubMed Central (United Kingdom)

In order to better understand how concepts might be represented in the brain, we used a cross-modal conceptual priming paradigm to examine how repetition-related activity changes in the brain are related to conceptual priming. During scanning, subjects made natural/manmade judgments on a continuous stream of spoken nouns, written nouns and pictures of objects. Each stimulus either repeated in the same or a different modality with 1-4 intervening trials between repetitions. Behaviorally, participants showed significant perceptual and conceptual priming effects. The fMRI data showed that the conditions associated with the greatest behavioral priming exhibited the largest decreases in BOLD activity in left perirhinal cortex (PRc), as well as a few other regions. Furthermore, the PRc was the only region to show this relationship for the cross-modal conditions alone, where the concept but not the percept repeated. Conversely, repetition-related increases in PRc activity predicted better subsequent memory as assessed by a post-scan recognition test. These results suggest that repetition-related activity changes in the PRc are related both to the speed of access to a repeated concept and to that concept's later memorability.

Heusser AC; Awipi T; Davachi L

2013-05-01

267

Long Term Survivors of Glioblastoma  

Directory of Open Access Journals (Sweden)

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.

Nezih OKTAR; Erkin ÖZG?RAY; Taner AKALIN

2009-01-01

268

Used fuel long term management  

Energy Technology Data Exchange (ETDEWEB)

This is a presentation on the long term management of used fuel. It discusses the Nuclear Fuel Waste (NFW) Act and formation of Waste Management Organisation (WMO), and requirements of the ACT and response of the owners of spent CANDU fuel (formation of JWO). Technical work programs include deep geological repository (DGR) technology and performance assessment tools, study options for long term management of the fuel and irradiated fuel studies (fuel behaviour in interim storage and in repository environment.

Villagran, J. [Ontario Power Generation, Toronto, Ontario (Canada)

2002-07-01

269

Dopaminergic control of long-term depression/long-term potentiation threshold in prefrontal cortex.  

Science.gov (United States)

Long-term memory in the prefrontal cortex is a necessary component of adaptive executive control and is strongly modulated by dopamine. However, the functional significance of this dopaminergic modulation remains elusive. In vitro experimental results on dopamine-dependent shaping of prefrontal long-term plasticity often appear inconsistent and, altogether, draw a complicated picture. It is also generally difficult to relate these findings to in vivo observations given strong differences between the two experimental conditions. This study presents a unified view of the functional role of dopamine in the prefrontal cortex by framing it within the Bienenstock-Cooper-Munro theory of cortical plasticity. We investigate dopaminergic modulation of long-term plasticity through a multicompartment Hodgkin-Huxley model of a prefrontal pyramidal neuron. Long-term synaptic plasticity in the model is governed by a calcium- and dopamine-dependent learning rule, in which dopamine exerts its action via D1 and D2 dopamine receptors in a concentration-dependent manner. Our results support a novel function of dopamine in the prefrontal cortex, namely that it controls the synaptic modification threshold between long-term depression and potentiation in pyramidal neurons. The proposed theoretical framework explains a wide range of experimental results and provides a link between in vitro and in vivo studies of dopaminergic plasticity modulation. It also suggests that dopamine may constitute a new player in metaplastic and homeostatic processes in the prefrontal cortex. PMID:23966711

Sheynikhovich, Denis; Otani, Satoru; Arleo, Angelo

2013-08-21

270

Long-term depression in the CNS.  

UK PubMed Central (United Kingdom)

Long-term depression (LTD) in the CNS has been the subject of intense investigation as a process that may be involved in learning and memory and in various pathological conditions. Several mechanistically distinct forms of this type of synaptic plasticity have been identified and their molecular mechanisms are starting to be unravelled. Most studies have focused on forms of LTD that are triggered by synaptic activation of either NMDARs (N-methyl-D-aspartate receptors) or metabotropic glutamate receptors (mGluRs). Converging evidence supports a crucial role of LTD in some types of learning and memory and in situations in which cognitive demands require a flexible response. In addition, LTD may underlie the cognitive effects of acute stress, the addictive potential of some drugs of abuse and the elimination of synapses in neurodegenerative diseases.

Collingridge GL; Peineau S; Howland JG; Wang YT

2010-07-01

271

Enhanced Long-Term and Impaired Short-Term Spatial Memory in GluA1 AMPA Receptor Subunit Knockout Mice: Evidence for a Dual-Process Memory Model  

Science.gov (United States)

|The GluA1 AMPA receptor subunit is a key mediator of hippocampal synaptic plasticity and is especially important for a rapidly-induced, short-lasting form of potentiation. GluA1 gene deletion impairs hippocampus-dependent, spatial working memory, but spares hippocampus-dependent spatial reference memory. These findings may reflect the necessity…

Sanderson, David J.; Good, Mark A.; Skelton, Kathryn; Sprengel, Rolf; Seeburg, Peter H.; Rawlins, J. Nicholas P.; Bannerman, David M.

2009-01-01

272

Sleep facilitates long-term face adaptation  

Science.gov (United States)

Adaptation is an automatic neural mechanism supporting the optimization of visual processing on the basis of previous experiences. While the short-term effects of adaptation on behaviour and physiology have been studied extensively, perceptual long-term changes associated with adaptation are still poorly understood. Here, we show that the integration of adaptation-dependent long-term shifts in neural function is facilitated by sleep. Perceptual shifts induced by adaptation to a distorted image of a famous person were larger in a group of participants who had slept (experiment 1) or merely napped for 90 min (experiment 2) during the interval between adaptation and test compared with controls who stayed awake. Participants' individual rapid eye movement sleep duration predicted the size of post-sleep behavioural adaptation effects. Our data suggest that sleep prevented decay of adaptation in a way that is qualitatively different from the effects of reduced visual interference known as ‘storage’. In the light of the well-established link between sleep and memory consolidation, our findings link the perceptual mechanisms of sensory adaptation—which are usually not considered to play a relevant role in mnemonic processes—with learning and memory, and at the same time reveal a new function of sleep in cognition.

Ditye, Thomas; Javadi, Amir Homayoun; Carbon, Claus-Christian; Walsh, Vincent

2013-01-01

273

Sleep facilitates long-term face adaptation.  

UK PubMed Central (United Kingdom)

Adaptation is an automatic neural mechanism supporting the optimization of visual processing on the basis of previous experiences. While the short-term effects of adaptation on behaviour and physiology have been studied extensively, perceptual long-term changes associated with adaptation are still poorly understood. Here, we show that the integration of adaptation-dependent long-term shifts in neural function is facilitated by sleep. Perceptual shifts induced by adaptation to a distorted image of a famous person were larger in a group of participants who had slept (experiment 1) or merely napped for 90 min (experiment 2) during the interval between adaptation and test compared with controls who stayed awake. Participants' individual rapid eye movement sleep duration predicted the size of post-sleep behavioural adaptation effects. Our data suggest that sleep prevented decay of adaptation in a way that is qualitatively different from the effects of reduced visual interference known as 'storage'. In the light of the well-established link between sleep and memory consolidation, our findings link the perceptual mechanisms of sensory adaptation-which are usually not considered to play a relevant role in mnemonic processes-with learning and memory, and at the same time reveal a new function of sleep in cognition.

Ditye T; Javadi AH; Carbon CC; Walsh V

2013-01-01

274

Sleep facilitates long-term face adaptation.  

Science.gov (United States)

Adaptation is an automatic neural mechanism supporting the optimization of visual processing on the basis of previous experiences. While the short-term effects of adaptation on behaviour and physiology have been studied extensively, perceptual long-term changes associated with adaptation are still poorly understood. Here, we show that the integration of adaptation-dependent long-term shifts in neural function is facilitated by sleep. Perceptual shifts induced by adaptation to a distorted image of a famous person were larger in a group of participants who had slept (experiment 1) or merely napped for 90 min (experiment 2) during the interval between adaptation and test compared with controls who stayed awake. Participants' individual rapid eye movement sleep duration predicted the size of post-sleep behavioural adaptation effects. Our data suggest that sleep prevented decay of adaptation in a way that is qualitatively different from the effects of reduced visual interference known as 'storage'. In the light of the well-established link between sleep and memory consolidation, our findings link the perceptual mechanisms of sensory adaptation-which are usually not considered to play a relevant role in mnemonic processes-with learning and memory, and at the same time reveal a new function of sleep in cognition. PMID:23986109

Ditye, Thomas; Javadi, Amir Homayoun; Carbon, Claus-Christian; Walsh, Vincent

2013-08-28

275

Long term radioactive waste management  

Energy Technology Data Exchange (ETDEWEB)

In France, waste management, a sensitive issue in term of public opinion, is developing quickly, and due to twenty years of experience, is now reaching maturity. With the launching of the French nuclear programme, the use of radioactive sources in radiotherapy and industry, waste management has become an industrial activity. Waste management is an integrated system dealing with the wastes from their production to the long term disposal, including their identification, sortage, treatment, packaging, collection and transport. This system aims at guaranteeing the protection of present and future populations with an available technology. In regard to their long term management, and the design of disposals, radioactive wastes are divided in three categories. This classification takes into account the different radioisotopes contained, their half life and their total activity. Presently short-lived wastes are stored in the shallowland disposal of the ''Centre de la Manche''. Set up within the French Atomic Energy Commission (CEA), the National Agency for waste management (ANDRA) is responsible within the framework of legislative and regulatory provisions for long term waste management in France.

Lavie, J.M. (Agence Nationale pour la Gestion des Dechets Radioactifs, 75 - Paris (France))

1984-02-01

276

Economic efficiency of the system of long-term core sample storage in the example of the base mechanized reservoir in Verkhnyaya Pyshma  

Energy Technology Data Exchange (ETDEWEB)

The technique of determining the economic efficiency of core sample storage as applied to conditions of the base mechanized reervoir in the Verkhniyaya Pyshma is briefly presented. Results are cited of calculations made according to this technique which compare the Pyshma mechanized reservoir with a number of prototype reservoirs. On this basis a conclusion is drawn regarding the significant advantage of the Verkhnyaya Pyshma reservoir in relation to the comparable.

Chelyashev, V.L.; Deryabin, N.N.

1980-01-01

277

Long term radio variability of AGN  

CERN Multimedia

A large number of AGN have been monitored for nearly 30 years at 22, 37 and 87 GHz in Mets\\"ahovi Radio Observatory. These data were combined with lower frequency 4.8, 8.0 and 14.5 GHz data from the University of Michigan Radio Astronomy Observatory, higher frequency data at 90 and 230 GHz from SEST, and supplementary higher frequency data from the literature to study the long-term variability of a large sample of AGN. Both the characteristics of individual flares from visual inspection and statistically-determined variability timescales as a function of frequency and optical class type were determined. Based on past behaviour, predictions of sources expected to exhibit large flares in 2008--2009 appropriate for study by GLAST and other instruments are made. The need for long-term data for properly understanding source behaviour is emphasised.

Hovatta, T; Lehto, H J; Nieppola, E; Valtaoja, E; lainela, M; Torniainen, I; Lähteenmäki, A; Aller, M F; Aller, H D

2008-01-01

278

Ascorbate and dehydroascorbic acid as reliable biomarkers of oxidative stress : analytical reproducibility and long-term stability of plasma samples subjected to acidic deproteinization  

DEFF Research Database (Denmark)

Lack of post-sampling stability of ascorbate and dehydroascorbic acid and failure to block their in vivo equilibrium have lowered their value as biomarkers of oxidative stress and limited the ability to further investigate their possible role in disease prevention. In the present paper, the analytical reproducibility was tested by repeated analysis of plasma aliquots from one individual over four years. The plasma was subjected to acidic deproteinization with an equal volume of 10% meta-phosphoric acid containing 2 mM EDTA and analyzed for ascorbate and dehydroascorbic acid by high-performance liquid chromatography with coulometric detection. In a parallel experiment, stability of human plasma samples treated as above and stored at -80°C for five years was tested in a cohort of 131 individuals. No degradation or shift in the equilibrium between ascorbate and dehydroascorbic acid was observed in either of the experiments. In conclusion, ascorbate and dehydroascorbic acid can be adequately preserved in plasma stored at -80°C following acidic deproteinization with meta-phosphoric acid containing 2 mM EDTA.

Lykkesfeldt, Jens

2007-01-01

279

Observations on the effects of different chemotherapy strategies on the transmission of Schistosoma mansoni in Machakos District, Kenya, measured by long-term snail sampling and cercariometry.  

UK PubMed Central (United Kingdom)

Transmission of Schistosoma mansoni was monitored by routine snail sampling for Biomphalaria pfeifferi and by supplementary cercariometric measurements in 4 neighbouring study areas in Machakos District, Kenya. After 1 year, extensive, population-based chemotherapy with a single dose of praziquantel was given in 3 areas, but only minimal treatment in the fourth. In the year preceding treatment, seasonal transmission of S. mansoni and other non-human trematodes occurred in all 4 areas, despite some ecological differences and the effects of earlier treatment campaigns in 1 of the study areas. After treatment of all infected subjects in one area in which there had been earlier chemotherapy campaigns, S. mansoni transmission remained very low. It was reduced for at least 2 years after chemotherapy targeted at either all heavily infected subjects or all infected school children, but it was unaffected in an area where treatment was restricted to those few very heavily infected cases at risk of developing disease. Nowhere was transmission entirely eliminated by chemotherapy and that of non-human trematodes continued unabated. The snail data correspond well with the human, parasitological data. Targeting school children was as effective as more extensive campaigns, but chemotherapy alone never stopped S. mansoni transmission: reinfection was inevitable, at rates determined by ecological factors affecting snail populations.

Sturrock RF; Klumpp RK; Ouma JH; Butterworth AE; Fulford AJ; Kariuki HC; Thiongo FW; Koech D

1994-11-01

280

Long term stability of power systems  

Energy Technology Data Exchange (ETDEWEB)

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

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

1994-12-31

 
 
 
 
281

Long-term economic outlook  

Energy Technology Data Exchange (ETDEWEB)

This update on the long-term economic outlook from the perspective of Ontario Hydro replaces a similar review issued in May 1989, with the main difference from the previous review being an increase in the inflation rate due to the introduction of the federal Goods and Services Tax, scheduled to be introduced on January 1, 1991. The document details changes since the May 1989 review in Ontario economic growth, sectoral distribution of output, inflation and the consumer price index, interest rates, the Canadian dollar exchange rate, and energy prices. Forecast tables are given for energy consumption in Ontario, Canada, the United States, and the Ontario industrial structure. 12 tabs

1989-09-01

282

Epilepsy-related long-term amnesia: anatomical perspectives.  

UK PubMed Central (United Kingdom)

There are few clues as to the neural basis of selective long-term amnesia. We report group and single-case data to shed light on this issue. In a group study of patients with transient epileptic amnesia, there were no significant correlations between volumetric measures of the hippocampus and indices of accelerated long-term forgetting or longer-term autobiographical memory loss. Post-mortem investigations in a patient with temporal lobe epilepsy who showed accelerated long-term forgetting, together with a degree of autobiographical memory loss, yielded evidence of neuronal loss and gliosis in regions of both the right and the left hippocampus. Neuronal loss and gliosis were more evident in anterior than posterior hippocampus. These results indicate that the unusual forms of long-term forgetting seen in some patients with temporal lobe epilepsy have no gross anatomical correlate. The findings leave open the possibilities that subtle structural damage or subtle functional disturbance, perhaps in the form of subclinical epileptiform activity, underly epilepsy-related long-term amnesia.

Butler C; Kapur N; Zeman A; Weller R; Connelly A

2012-11-01

283

Physiological, Molecular and Genetic Mechanisms of Long-Term Habituation  

Energy Technology Data Exchange (ETDEWEB)

Work funded on this grant has explored the mechanisms of long-term habituation, a ubiquitous form of learning that plays a key role in basic cognitive functioning. Specifically, behavioral, physiological, and molecular mechanisms of habituation have been explored using a simple model system, the tail-elicited siphon-withdrawal reflex (T-SWR) in the marine mollusk Aplysia californica. Substantial progress has been made on the first and third aims, providing some fundamental insights into the mechanisms by which memories are stored. We have characterized the physiological correlates of short- and long-term habituation. We found that short-term habituation is accompanied by a robust sensory adaptation, whereas long-term habituation is accompanied by alterations in sensory and interneuron synaptic efficacy. Thus, our data indicates memories can be shifted between different sites in a neural network as they are consolidated from short to long term. At the molecular level, we have accomplished microarray analysis comparing gene expression in both habituated and control ganglia. We have identified a network of putatively regulated transcripts that seems particularly targeted towards synaptic changes (e.g. SNAP25, calmodulin) . We are now beginning additional work to confirm regulation of these transcripts and build a more detailed understanding of the cascade of molecular events leading to the permanent storage of long-term memories. On the third aim, we have fostered a nascent neuroscience program via a variety of successful initiatives. We have funded over 11 undergraduate neuroscience scholars, several of whom have been recognized at national and regional levels for their research. We have also conducted a pioneering summer research program for community college students which is helping enhance access of underrepresented groups to life science careers. Despite minimal progress on the second aim, this project has provided a) novel insight into the network mechanisms by which short-term memories are permanently stored, and b) a strong foundation for continued growth of an excellent undergraduate neuroscience program.

Calin-Jageman, Robert J

2009-09-12

284

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

1980-12-12

285

Long-term economic outlook  

Energy Technology Data Exchange (ETDEWEB)

This update on the long-term economic outlook from the perspective of Ontario Hydro replaces a similar review issued in September 1990. The revised forecast is similar to last year's outlook. It calls for a continuing decline in the trend rate of growth of Ontario's gross domestic product, to an average of about 2.5% per year at the end of the forecast horizon, due to slower growth in the labour force. It continues to assume that inflation will remain moderate, rather than declining sharply as called for by the Bank of Canada's targets. Real interest rates are expected to decline gradually, and the Canadian dollar is expected to return to a more sustainable value in the area of 80 U.S. cents. The document details changes since the September 1990 review in Ontario economic growth, industrial prospects and problems, inflation and the consumer price index, interest rates, the Canadian dollar exchange rate, environmental policies, and energy prices. Forecast tables are given for energy consumption in Ontario, Canada, the United States, and the Ontario industrial structure. 7 tabs.

1991-09-01

286

Long-term corrosion studies  

International Nuclear Information System (INIS)

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

1998-01-01

287

Outlook positive over long term  

Energy Technology Data Exchange (ETDEWEB)

The trends established in 1987 will be very important in reestablishing some level of confidence in future price expectations. The authors expect prices to fluctuate widely in the coming year as OPEC makes and breaks various production quota agreements. Continued price instability will certainly all but negate short term marginally economic exploration and development prospects. Utilization rates will suffer accordingly. But on the positive side, the long term outlook is considerably more stable. Rock-bottom prices will increase the demand for cheap oil substantially. We're already seeing world demand figures rise. Increased demand will cause the world's (mainly OPEC's) excess production to be depleted over the next three to five years. Prices will rise slowly in parallel with the decline in excess production capacity over several years. Banking on upward price pressure, financially sound operators with solid cash flow will want to take advantage of low exploration and development costs. Utilization, then, can be expected to follow oil prices in a slow upward spiral over the next three to five years. Next year, the industry should begin to feel the effect of the beginning of that upward trend.

1986-11-01

288

Developmental aspects of working and associative memory.  

UK PubMed Central (United Kingdom)

Developmental differences between working and long-term associative memory were evaluated through a cross-sectional age difference study based on data from a memory battery's standardization sample. The scores of 856 children and adolescents ranging from 5 to 17 years of age were compared on memory subtests that assess verbal working and long-term memory. Data were examined using curve fitting and ANOVA procedures that evaluated age group and years of age differences. The major finding was that the developmental trajectories across age differed substantially between the two memory domains. The working memory trajectory was linear until age 11, whereas the long-term memory trajectory was curvilinear with an inflection point at age 8. Both trajectories plateaued after age 11. ANOVAs produced significant interactions between tests of working and associative memory with age, supporting the view that the age trajectories had differing courses. The results are discussed in terms of neurobiological implications for the two memory systems studied.

Thaler NS; Goldstein G; Pettegrew JW; Luther JF; Reynolds CR; Allen DN

2013-06-01

289

Evaluation of the effects of long-term storage of bovine ear notch samples on the ability of 2 diagnostic assays to identify calves persistently infected with bovine viral diarrhoea virus  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Research aimed at optimising diagnostic laboratory procedures is central to the development of effective bovine viral diarrhoea virus (BVDV) control programmes. BVDV is a singlestranded RNA virus that crosses the placenta to infect foetuses, resulting in reproductive losses due to foetal death or persistently infected calves that die early in life. Persistently infected animals are widely accepted to be the primary reservoir of BVDV and the largest source of infection. Th (more) is 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

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

2011-01-01

290

Rasch analysis of the Mini-Mental Adjustment to Cancer Scale (mini-MAC) among a heterogeneous sample of long-term cancer survivors: a cross-sectional study.  

UK PubMed Central (United Kingdom)

BACKGROUND: The mini-Mental Adjustment to Cancer Scale (mini-MAC) is a well-recognised, popular measure of coping in psycho-oncology and assesses five cancer-specific coping strategies. It has been suggested that these five subscales could be grouped to form the over-arching adaptive and maladptive coping subscales to facilitate the interpretation and clinical application of the scale. Despite the popularity of the mini-MAC, few studies have examined its psychometric properties among long-term cancer survivors, and further validation of the mini-MAC is needed to substantiate its use with the growing population of survivors. Therefore, this study examined the psychometric properties and dimensionality of the mini-MAC in a sample of long-term cancer survivors using Rasch analysis. METHODS: RUMM 2030 was used to analyse the mini-MAC data (n=851). Separate Rasch analyses were conducted for each of the original mini-MAC subscales as well as the over-arching adaptive and maladaptive coping subscales to examine summary and individual model fit statistics, person separation index (PSI), response format, local dependency, targeting, item bias (or differential item functioning -DIF), and dimensionality. RESULTS: For the fighting spirit, fatalism, and helplessness-hopelessness subscales, a revised three-point response format seemed more optimal than the original four-point response. To achieve model fit, items were deleted from four of the five subscales - Anxious Preoccupation items 7, 25, and 29; Cognitive Avoidance items 11 and 17; Fighting Spirit item 18; and Helplessness-Hopelessness items 16 and 20. For those subscales with sufficient items, analyses supported unidimensionality. Combining items to form the adaptive and maladaptive subscales was partially supported. CONCLUSIONS: The original five subscales required item deletion and/or rescaling to improve goodness of fit to the Rasch model. While evidence was found for overarching subscales of adaptive and maladaptive coping, extensive modifications were necessary to achieve this result. Further exploration and validation of over-arching subscales assessing adaptive and maladaptive coping is necessary with cancer survivors.

Zucca A; Lambert SD; Boyes AW; Pallant JF

2012-01-01

291

Rasch analysis of the Mini-Mental Adjustment to Cancer Scale (mini-MAC) among a heterogeneous sample of long-term cancer survivors: A cross-sectional study  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The mini-Mental Adjustment to Cancer Scale (mini-MAC) is a well-recognised, popular measure of coping in psycho-oncology and assesses five cancer-specific coping strategies. It has been suggested that these five subscales could be grouped to form the over-arching adaptive and maladptive coping subscales to facilitate the interpretation and clinical application of the scale. Despite the popularity of the mini-MAC, few studies have examined its psychometric properties among long-term cancer survivors, and further validation of the mini-MAC is needed to substantiate its use with the growing population of survivors. Therefore, this study examined the psychometric properties and dimensionality of the mini-MAC in a sample of long-term cancer survivors using Rasch analysis. Methods RUMM 2030 was used to analyse the mini-MAC data (n=851). Separate Rasch analyses were conducted for each of the original mini-MAC subscales as well as the over-arching adaptive and maladaptive coping subscales to examine summary and individual model fit statistics, person separation index (PSI), response format, local dependency, targeting, item bias (or differential item functioning -DIF), and dimensionality. Results For the fighting spirit, fatalism, and helplessness-hopelessness subscales, a revised three-point response format seemed more optimal than the original four-point response. To achieve model fit, items were deleted from four of the five subscales – Anxious Preoccupation items 7, 25, and 29; Cognitive Avoidance items 11 and 17; Fighting Spirit item 18; and Helplessness-Hopelessness items 16 and 20. For those subscales with sufficient items, analyses supported unidimensionality. Combining items to form the adaptive and maladaptive subscales was partially supported. Conclusions The original five subscales required item deletion and/or rescaling to improve goodness of fit to the Rasch model. While evidence was found for overarching subscales of adaptive and maladaptive coping, extensive modifications were necessary to achieve this result. Further exploration and validation of over-arching subscales assessing adaptive and maladaptive coping is necessary with cancer survivors.

Zucca Alison; Lambert Sylvie D; Boyes Allison W; Pallant Julie F

2012-01-01

292

Long term dynamics: its perspectives in Brazil  

Energy Technology Data Exchange (ETDEWEB)

This work presents an analysis of the perspectives of Long Term Dynamic in Brazil based on recent survey produced by TF 38-02-08 of CIGRE. Disturbances that occurred in the Brazilian power system that required extended simulation are mentioned. Desired characteristics for long term dynamic tools are also commented. A typical numerical algorithm for long term dynamics simulation is implemented and tested. (author)

Jardim, Jorge Luiz [FURNAS Centrais Eletricas S.A., Rio de Janeiro, RJ (Brazil); Vieira Filho, Xisto [CEPEL, Rio de Janeiro, RJ (Brazil)

1996-07-01

293

Age, memory type, and the phenomenology of autobiographical memory: Findings from an Italian sample.  

Science.gov (United States)

The present research explored differences in phenomenology between two types of memories, a general self-defining memory and an earliest childhood memory. A sample of 76 Italian participants were selected and categorised into two age groups: 20-30 years and 31-40 years. The Memory Experiences Questionnaire (MEQ) was administered, taking note of latency and duration times of the narratives. Consistent with the literature, the self-defining memory differed significantly from the earliest childhood memory in terms of phenomenology, with the recency of the memory associated with more intense phenomenological experience. The self-defining memory took longer to retrieve and narrate than the earliest childhood memory. Meaningful differences also emerged between the two age groups: Participants in their 30s rated their self-defining memory as more vivid, coherent, and accessible than participants in their 20s. According to latency findings, these differences suggest an expanded period of identity consolidation for younger adults. Further applications of the MEQ should be carried out to replicate these results with other samples of young adults. PMID:23586480

Montebarocci, Ornella; Luchetti, Martina; Sutin, Angelina R

2013-04-16

294

Comparison of propidium monoazide-quantitative PCR and reverse transcription quantitative PCR for viability detection of fresh Cryptosporidium oocysts following disinfection and after long-term storage in water samples.  

Science.gov (United States)

Purified oocysts of Cryptosporidium parvum were used to evaluate the applicability of two quantitative PCR (qPCR) viability detection methods in raw surface water and disinfection treated water. Propidium monoazide-qPCR targeting hsp70 gene was compared to reverse transcription (RT)-qPCR heat induced hsp70 mRNA in water samples spiked with oocysts. Changes in viability of flow cytometry sorted fresh and oocysts having undergone various aging periods (up to 48 months at 4 °C) were evaluated by Ct values obtained from the qPCR before and after disinfection scenarios involving ammonia or hydrogen peroxide. Both qPCR methods achieved stability in dose dependent responses by hydrogen peroxide treatment in distilled water that proved their suitability for the viability evaluations. Oocysts exposed to 3% hydrogen peroxide were inactivated at a rate of 0.26 h(-1) and 0.93 h(-1), as measured by the mRNA assay and the PMA-DNA assay, respectively. In contrast, the PMA-DNA assay was not as sensitive as the mRNA assay in detecting viability alterations followed by exposure to ammonia or after a long-term storage in 4 °C in distilled water since no dose response dependency was achieved. Surface water concentrates containing enhanced suspendable solids determined that changes in viability were frequently detected only by the mRNA method. Failure of, or inconsistency in the detection of oocysts viability with the PMA-DNA method, apparently resulted from solids that might have reduced light penetration through the samples, and thus inhibited the cross-linking step of PMA-DNA assay. PMID:22980572

Liang, Zhanbei; Keeley, Ann

2012-08-23

295

Comparison of propidium monoazide-quantitative PCR and reverse transcription quantitative PCR for viability detection of fresh Cryptosporidium oocysts following disinfection and after long-term storage in water samples.  

UK PubMed Central (United Kingdom)

Purified oocysts of Cryptosporidium parvum were used to evaluate the applicability of two quantitative PCR (qPCR) viability detection methods in raw surface water and disinfection treated water. Propidium monoazide-qPCR targeting hsp70 gene was compared to reverse transcription (RT)-qPCR heat induced hsp70 mRNA in water samples spiked with oocysts. Changes in viability of flow cytometry sorted fresh and oocysts having undergone various aging periods (up to 48 months at 4 °C) were evaluated by Ct values obtained from the qPCR before and after disinfection scenarios involving ammonia or hydrogen peroxide. Both qPCR methods achieved stability in dose dependent responses by hydrogen peroxide treatment in distilled water that proved their suitability for the viability evaluations. Oocysts exposed to 3% hydrogen peroxide were inactivated at a rate of 0.26 h(-1) and 0.93 h(-1), as measured by the mRNA assay and the PMA-DNA assay, respectively. In contrast, the PMA-DNA assay was not as sensitive as the mRNA assay in detecting viability alterations followed by exposure to ammonia or after a long-term storage in 4 °C in distilled water since no dose response dependency was achieved. Surface water concentrates containing enhanced suspendable solids determined that changes in viability were frequently detected only by the mRNA method. Failure of, or inconsistency in the detection of oocysts viability with the PMA-DNA method, apparently resulted from solids that might have reduced light penetration through the samples, and thus inhibited the cross-linking step of PMA-DNA assay.

Liang Z; Keeley A

2012-11-01

296

Preschool speech intelligibility and vocabulary skills predict long-term speech and language outcomes following cochlear implantation in early childhood.  

UK PubMed Central (United Kingdom)

Speech and language measures during grade school predict adolescent speech-language outcomes in children who receive cochlear implants (CIs), but no research has examined whether speech and language functioning at even younger ages is predictive of long-term outcomes in this population. The purpose of this study was to examine whether early preschool measures of speech and language performance predict speech-language functioning in long-term users of CIs. Early measures of speech intelligibility and receptive vocabulary (obtained during preschool ages of 3-6 years) in a sample of 35 prelingually deaf, early-implanted children predicted speech perception, language, and verbal working memory skills up to 18 years later. Age of onset of deafness and age at implantation added additional variance to preschool speech intelligibility in predicting some long-term outcome scores, but the relationship between preschool speech-language skills and later speech-language outcomes was not significantly attenuated by the addition of these hearing history variables. These findings suggest that speech and language development during the preschool years is predictive of long-term speech and language functioning in early-implanted, prelingually deaf children. As a result, measures of speech-language functioning at preschool ages can be used to identify and adjust interventions for very young CI users who may be at long-term risk for suboptimal speech and language outcomes.

Castellanos I; Kronenberger WG; Beer J; Henning SC; Colson BG; Pisoni DB

2013-08-01

297

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

Directory of Open Access Journals (Sweden)

Full Text Available Exposure to elements in groundwater (toxic or beneficial) is commonplace yet, outside of lead and mercury, little research has examined the impact of many commonly occurring environmental exposures on mental abilities during the aging process. Inorganic arsenic is a known neurotoxin that has both neurodevelopmental and neurocognitive consequences. The aim of this study was to examine the potential association between current and long-term arsenic exposure and detailed neuropsychological functioning in a sample of rural-dwelling adults and elders. Data were analyzed from 434 participants (133 men and 301 women) of Project FRONTIER, a community-based participatory research study of the epidemiology of health issues of rural-dwelling adults and elders. The results of the study showed that GIS-based groundwater arsenic exposure (current and long-term) was significantly related to poorer scores in language, visuospatial skills, and executive functioning. Additionally, long-term low-level exposure to arsenic was significantly correlated to poorer scores in global cognition, processing speed and immediate memory. The finding of a correlation between arsenic and the domains of executive functioning and memory is of critical importance as these are cognitive domains that reflect the earliest manifestations of Alzheimer’s disease. Additional work is warranted given the population health implications associated with long-term low-level arsenic exposure.

Sid E. O’Bryant; Melissa Edwards; Chloe V. Menon; Gordon Gong; Robert Barber

2011-01-01

298

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)

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

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

2010-12-15

299

Reversing cerebellar long-term depression  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The discovery of a postsynaptically expressed form of cerebellar parallel fiber–Purkinje cell long-term potentiation (LTP) raises the question whether this is the long-sought resetting mechanism for long-term depression (LTD). Extracellular monitoring of PC spikes enables stable prolonged recordings...

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

300

Long-term preservation of Anammox bacteria  

Science.gov (United States)

Deposit of useful microorganisms in culture collections requires long-term preservation and successful reactivation techniques. The goal of this study was to develop a simple preservation protocol for the long-term storage and reactivation of the anammox biomass. To achieve this, anammox biomass w...

 
 
 
 
301

Long-term survival after perforated diverticulitis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Aim: Short-term survival after emergency surgery for perforated diverticulitis is poor. Less is known about long-term survival. The aims of this study were to evaluate long-term survival after discharge from hospital and to identify factors associated with prognosis. Method: All patients who underwe...

Vermeulen, J.; Gosselink, M.P.; Hop, W.C.J.; Harst, E. van der; Hansen, B.E.; Mannaerts, G.H.H.; Coene, P-P.; Weidema, W.F.

302

Financing long-term care in Canada.  

Science.gov (United States)

Financial policies relating to long-term care in Canada are changing rapidly in response to demands for health care reform. This chapter focuses on the financial structure of institutional care, primarily nursing homes, in the western provinces of Alberta and British Columbia. Community-based long-term care is discussed briefly. PMID:10169492

Jacobs, P; Mills, C; Hollander, M

1997-06-01

303

Financing long-term care in Canada.  

UK PubMed Central (United Kingdom)

Financial policies relating to long-term care in Canada are changing rapidly in response to demands for health care reform. This chapter focuses on the financial structure of institutional care, primarily nursing homes, in the western provinces of Alberta and British Columbia. Community-based long-term care is discussed briefly.

Jacobs P; Mills C; Hollander M

1997-06-01

304

The natural abundance of 13C, 15N, 34S and 14C in archived (1923-2000) plant and soil samples from the Askov long-term experiments on animal manure and mineral fertilizer.  

UK PubMed Central (United Kingdom)

The Askov field experiment (Denmark), established in 1894, provides a unique opportunity to examine long-term effects of animal manure and mineral fertilizer on soil organic matter quality and turnover. This sandy loam soil is classified as Alfisol (Typic Hapludalf). Soil C, N, S, 13C, 15N, 34S and 14C contents were measured in a selection of archived soil samples (1923, 1938, 1945, 1953, 1964, 1976, 1985, 1996 and 2000) from unfertilized (O), animal manure (1 AM) and mineral fertilizer (1 NPK) treatments. These treatments are imbedded in a four-course crop rotation of winter cereals, root crops, spring cereals and a clover/grass mixture. The contents of C, N, S, 13C, 15N and 34S in selected crop samples (1953-1996) and in contemporary samples of animal feed and manure were also determined. Temporal soil nutrient and isotope trends between fertilizer treatments were significantly different, except for S content in 1 AM and 1 NPK. The total soil C and S was higher in 1 AM and 1 NPK than in the O treatment. The total soil N content (1 AM>1 NPK>O) and the delta15N content (1 AM>1 NPK and O) were also different. Analyses of plant, animal feed and manures confirmed that differences in soil 15N values were related to delta15N values of added source inputs. Soil and crop delta13C values were similar, but manures had slightly lower values. The variation of soil delta34S (and total S) from 1923 to 1996 was larger in the O than 1 AM and 1 NPK plots reflecting changes in atmospheric S inputs. The total contents of soil C, N and S were significantly correlated, but their isotopic signatures were not, suggesting that the C, N, S turnovers in soil are subject to different controls. The 14C content was generally higher in the 1 AM than 1 NPK and O, with bomb-14C incorporation modelling indicating that mean residence time (MRT) was ca. 170 years in the 1 AM, but closer to 250-290 years in the 1 NPK and O treatments. The measured trends in soil C and 14C during 1923-1996 were successfully modelled using the RothC model. The OM accumulation in the Askov soils was generally dominated by microbial decomposition products rather than by recalcitrant components of the various inputs.

Bol R; Eriksen J; Smith P; Garnett MH; Coleman K; Christensen BT

2005-01-01

305

Principles of long-term dynamics of dendritic spines.  

UK PubMed Central (United Kingdom)

Long-term potentiation of synapse strength requires enlargement of dendritic spines on cerebral pyramidal neurons. Long-term depression is linked to spine shrinkage. Indeed, spines are dynamic structures: they form, change their shapes and volumes, or can disappear in the space of hours. Do all such changes result from synaptic activity, or do some changes result from intrinsic processes? How do enlargement and shrinkage of spines relate to elimination and generation of spines, and how do these processes contribute to the stationary distribution of spine volumes? To answer these questions, we recorded the volumes of many individual spines daily for several days using two-photon imaging of CA1 pyramidal neurons in cultured slices of rat hippocampus between postnatal days 17 and 23. With normal synaptic transmission, spines often changed volume or were created or eliminated, thereby showing activity-dependent plasticity. However, we found that spines changed volume even after we blocked synaptic activity, reflecting a native instability of these small structures over the long term. Such "intrinsic fluctuations" showed unique dependence on spine volume. A mathematical model constructed from these data and the theory of random fluctuations explains population behaviors of spines, such as rates of elimination and generation, stationary distribution of volumes, and the long-term persistence of large spines. Our study finds that generation and elimination of spines are more prevalent than previously believed, and spine volume shows significant correlation with its age and life expectancy. The population dynamics of spines also predict key psychological features of memory.

Yasumatsu N; Matsuzaki M; Miyazaki T; Noguchi J; Kasai H

2008-12-01

306

Effects of naloxone on the long-term potentiation of EPSPs from the pathway of Schaffer collateral to CA1 region of hippocampus in aged rats with declined memory.  

UK PubMed Central (United Kingdom)

Morris water maze (MWM) was employed to distinguish the aged rats with declined memory to investigate the effect of naloxone on the synaptic plasticity of hippocampus in declined memory aged rats. After administration with naloxone for 7 days, LTP of excitatory post-synaptic potentials (EPSPs) from Schaffer collateral to CA1 region was recorded. The results showed that the maintenance of LTP of EPSPs from Schaffer collateral to CA1 subfield in isolate hippocampal brain slice was prolonged by naloxone with improved Morris water maze performance and reduced threshold of EPSPs. It is suggested that naloxone can improve learning and memory through enhancement of the synaptic plasticity of hippocampus in aged rats with declined memory.

Zhao H; Xu H; Xu X

2004-01-01

307

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)

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.

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

2012-01-01

308

Long term effects of radiation in man  

Energy Technology Data Exchange (ETDEWEB)

An overview of the long term effects of radiation in man is presented, categorizing into somatic effects, genetic effects and teratogenic effects, and including an indication of the problems that arise in their determination.

Tso Chih Ping (Malaya Univ., Kuala Lumpur (Malaysia)); Idris Besar (PUSPATI, Selangor (Malaysia))

1984-06-01

309

Long term wet spent nuclear fuel storage  

International Nuclear Information System (INIS)

[en] 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

1987-01-01

310

Long term liquidity analysis of the firm  

Directory of Open Access Journals (Sweden)

Full Text Available Liquidity control is a very difficult and important function. If the business is not liquid in the long term, it is under threatof bankruptcy, and on the other hand surplus of the cash in hand threaten its future efficiency, because the cash in hand is a sourceof only limited profitability. Long term liquidity is related to the ability of the short term and long term liabilities payment. Articleis trying to point out to the monitoring and analyzing of the long term liquidity in the concrete business, in this case the printing industrycompany. Hereby at the end of the article mentioned monitored and analyzed liquidity is evaluated in the five years time period.

Jaroslav Gonos

2009-01-01

311

Long-term outcome after coronary stenting  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract The present review assesses the data on long-term outcome after coronary stenting. Histological, angiographical and intravascular imaging data have shown that the insertion of stents constitutes only a transient stimulus to lumen renarrowing, that this process is almost complete at 6 months and that a certain degree of neointima regression is also possible after this time. Clinical data have confirmed the sustained benefit of stenting in the long term. Careful selection of optimal stent designs and application of the recent advances in adjunctive pharmacological therapy are currently effective strategies to improve both short-and long-term results with coronary stenting. However, further efforts are needed and are ongoing to combat restenosis, a process that counters the excellent short-term results of stenting in the long term.

Kastrati Adnan; Hall Donald; Schömig Albert

2000-01-01

312

Who Pays for Long-Term Care?  

Science.gov (United States)

... non-skilled assistance with Activities of Daily Living (ADL), which make up the majority of long-term ... on the amount of assistance you need with ADL Other federal programs such as the Older Americans ...

313

Modeling long-term distributions of significant wave height  

Energy Technology Data Exchange (ETDEWEB)

The problems involved with the use of parametric models to describe the long-term behavior of the significant wave height are discussed. In particular, it is shown that the usual understanding of good fit does not ensure a good representation of the tails. The problem of defining a population and of choosing one sample for inferring the parameters of the distribution is discussed. In particular, the time-varying character of the data is illustrated. A new model of long-term distribution is proposed which accounts for this variability.

Guedes Soares, C.; Ferreira, J.A. [Technical Univ. of Lisbon, Lisboa (Portugal). Unit of Marine Technology and Engineering

1995-12-31

314

A long-term, multitrophic level study to assess pulp and paper mill effluent effects on aquatic communities in four US receiving waters: characteristics of the study streams, sample sites, mills, and mill effluents.  

UK PubMed Central (United Kingdom)

Watershed characteristics, study streams, sample sites, mills, and mill effluents are provided for 4 streams included in a long-term study to assess potential effects of pulp and paper mill effluents on US receiving waters. The study streams are Codorus Creek (Pennsylvania, USA), Leaf River (Mississippi, USA) and McKenzie and Willamette rivers (Oregon, USA) and were chosen to represent a blend of mill process types, effluent concentrations, and coldwater/warmwater stream systems. The described effluent quality, water quality, and habitat data sets encompass the initial 7 to 8 y of a study anticipated to continue >10 y and provide a backdrop to a series of articles describing periphyton, macroinvertebrate, and fish community properties in these same streams. The mean in-stream waste concentration (IWC) for these 4 effluent discharges was 32.4%, 2.0%, 0.5%, and 0.2% v/v for Codorus Creek and Leaf, McKenzie, and Willamette rivers, respectively, as compared with a median of 0.4% for US mills. Effluent quality measurements included Selenastrum capricornutum, Ceriodaphnia dubia, and Pimephales promelas chronic bioassays as sanctioned by the US Environmental Protection Agency for estimating effluent effects on receiving-water aquatic communities. Based on mean bioassay inhibition concentration for a 25% effect and on mean IWC, a margin of safety against adverse biological effects of 2, 25, 137, and 150 times was indicated for Codorus Creek and Leaf, McKenzie, and Willamette rivers, respectively. Habitat and water quality assessment was carried out over a gradient of sample sites above and below the effluent discharge to determine nonmill-related conditions that might interfere with interpretation of effluent effects. Noneffluent related localized differences in conditions for some parameters, including current velocity (McKenzie River), and surface incident photosynthetically active radiation (Codorus Creek and Willamette River) occurred at the sample stations immediately upstream or downstream of the effluent discharge. In addition, broader watershed differences were evident on Codorus Creek, where a relatively rich riparian corridor and stream structure occurred upstream in contrast to areas of canopy and stream-structure loss in the downstream urban area. The mill effluent discharges contributed to increases in receiving-water color and conductivity, although upstream tributaries contributed additional conductivity to Codorus Creek and color to the Leaf River. The McKenzie River provided the only example of a nutrient increase immediately downstream of a mill discharge. This increase in total nitrogen (0.11 vs 0.16 mg/L) could not, however, be differentiated with respect to whether it was of mill effluent or tributary stream origin. Tributary streams were potentially important total nitrogen contributors on Codorus Creek and the Willamette River. As an integrated study, the effluent quality and physical/chemical watershed descriptions provided here represent 1 component of the broader study addressing potential point-source effluent effects within the context of the larger watershed and a multiyear timescale. The absence of effluent-related in-stream chemical/physical responses, other than increases in conductivity and color, and a considerable bioassay-based margin of safety, provides for a working hypothesis that there will be no effluent-related biological population/community responses from these 4 mill discharges. This hypothesis, as it relates to periphyton, macroinvertebrate, and fish communities, will be addressed in other articles in this series.

Hall TJ; Ragsdale RL; Arthurs WJ; Ikoma J; Borton DL; Cook DL

2009-04-01

315

A long-term, multitrophic level study to assess pulp and paper mill effluent effects on aquatic communities in four US receiving waters: characteristics of the study streams, sample sites, mills, and mill effluents.  

Science.gov (United States)

Watershed characteristics, study streams, sample sites, mills, and mill effluents are provided for 4 streams included in a long-term study to assess potential effects of pulp and paper mill effluents on US receiving waters. The study streams are Codorus Creek (Pennsylvania, USA), Leaf River (Mississippi, USA) and McKenzie and Willamette rivers (Oregon, USA) and were chosen to represent a blend of mill process types, effluent concentrations, and coldwater/warmwater stream systems. The described effluent quality, water quality, and habitat data sets encompass the initial 7 to 8 y of a study anticipated to continue >10 y and provide a backdrop to a series of articles describing periphyton, macroinvertebrate, and fish community properties in these same streams. The mean in-stream waste concentration (IWC) for these 4 effluent discharges was 32.4%, 2.0%, 0.5%, and 0.2% v/v for Codorus Creek and Leaf, McKenzie, and Willamette rivers, respectively, as compared with a median of 0.4% for US mills. Effluent quality measurements included Selenastrum capricornutum, Ceriodaphnia dubia, and Pimephales promelas chronic bioassays as sanctioned by the US Environmental Protection Agency for estimating effluent effects on receiving-water aquatic communities. Based on mean bioassay inhibition concentration for a 25% effect and on mean IWC, a margin of safety against adverse biological effects of 2, 25, 137, and 150 times was indicated for Codorus Creek and Leaf, McKenzie, and Willamette rivers, respectively. Habitat and water quality assessment was carried out over a gradient of sample sites above and below the effluent discharge to determine nonmill-related conditions that might interfere with interpretation of effluent effects. Noneffluent related localized differences in conditions for some parameters, including current velocity (McKenzie River), and surface incident photosynthetically active radiation (Codorus Creek and Willamette River) occurred at the sample stations immediately upstream or downstream of the effluent discharge. In addition, broader watershed differences were evident on Codorus Creek, where a relatively rich riparian corridor and stream structure occurred upstream in contrast to areas of canopy and stream-structure loss in the downstream urban area. The mill effluent discharges contributed to increases in receiving-water color and conductivity, although upstream tributaries contributed additional conductivity to Codorus Creek and color to the Leaf River. The McKenzie River provided the only example of a nutrient increase immediately downstream of a mill discharge. This increase in total nitrogen (0.11 vs 0.16 mg/L) could not, however, be differentiated with respect to whether it was of mill effluent or tributary stream origin. Tributary streams were potentially important total nitrogen contributors on Codorus Creek and the Willamette River. As an integrated study, the effluent quality and physical/chemical watershed descriptions provided here represent 1 component of the broader study addressing potential point-source effluent effects within the context of the larger watershed and a multiyear timescale. The absence of effluent-related in-stream chemical/physical responses, other than increases in conductivity and color, and a considerable bioassay-based margin of safety, provides for a working hypothesis that there will be no effluent-related biological population/community responses from these 4 mill discharges. This hypothesis, as it relates to periphyton, macroinvertebrate, and fish communities, will be addressed in other articles in this series. PMID:19063588

Hall, Timothy J; Ragsdale, Renee L; Arthurs, William J; Ikoma, Joan; Borton, Dennis L; Cook, Diana L

2009-04-01

316

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)

2002-01-01

317

Theta reset produces optimal conditions for long-term potentiation.  

UK PubMed Central (United Kingdom)

Connections among theta rhythm, long-term potentiation (LTP) and memory in hippocampus are suggested by previous research, but definitive links are yet to be established. We investigated the hypothesis that resetting of local hippocampal theta to relevant stimuli in a working memory task produces optimal conditions for induction of LTP. The timings of the peak and trough of the first wave of reset theta were determined in initial sessions and used to time stimulation (4 pulses, 200 Hz) during subsequent performance. Stimulation on the peak of stimulus-reset theta produced LTP while stimulation on the trough did not. These results suggest that a memory-relevant stimulus produces a phase shift of ongoing theta rhythm that induces optimal conditions for the stimulus to undergo potentiation.

McCartney H; Johnson AD; Weil ZM; Givens B

2004-01-01

318

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  

Directory of Open Access Journals (Sweden)

Full Text Available 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 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.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 foram 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.

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

2011-01-01

319

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)

Full Text Available Abstract in portuguese 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 foram 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, qu (more) ando 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 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 (more) 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.

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

2011-12-01

320

Hormonal changes during long-term isolation.  

UK PubMed Central (United Kingdom)

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.

Custaud MA; Belin de Chantemele E; Larina IM; Nichiporuk IA; Grigoriev A; Duvareille M; Gharib C; Gauquelin-Koch G

2004-05-01

 
 
 
 
321

Distinct long-term neurocognitive outcomes after equipotent sevoflurane or isoflurane anaesthesia in immature rats.  

UK PubMed Central (United Kingdom)

BACKGROUND: Many anaesthetics when given to young animals cause cell death and learning deficits that persist until much later in life. Recent attempts to compare the relative safety or toxicity between different agents have not adequately controlled for the relative dose of anaesthetic given, thereby making direct comparisons difficult. METHODS: Isoflurane or sevoflurane were given at 1 minimum alveolar concentration (MAC) for 4 h to postnatal day 7 (P7) rat pups. Beginning at P75 these animals underwent fear conditioning and at P83 Morris water maze testing to assess working memory, short-term memory and early long-term memory using delays of 1 min, 1 h, and 4 h. RESULTS: No difference between groups was seen in fear conditioning experiments. Morris water maze learning was equivalent between groups, and no difference was seen in working memory. Sevoflurane-treated animals had a deficit in early long-term memory, and isoflurane-treated animals had a deficit in both short-term and early long-term memory. CONCLUSIONS: Both isoflurane and sevoflurane delivered at 1 MAC for 4 h to immature rats caused a deficit in long-term memory. Isoflurane also caused a deficit in short-term memory. Isoflurane might be more detrimental than sevoflurane in very young animals.

Ramage TM; Chang FL; Shih J; Alvi RS; Quitoriano GR; Rau V; Barbour KC; Elphick SA; Kong CL; Tantoco NK; Ben-Tzur D; Kang H; McCreery MS; Huang P; Park A; Uy J; Rossi MJ; Zhao C; Di Geronimo RT; Stratmann G; Sall JW

2013-06-01

322

Sleep oscillations in the thalamocortical system induce long-term neuronal plasticity.  

UK PubMed Central (United Kingdom)

Long-term plasticity contributes to memory formation and sleep plays a critical role in memory consolidation. However, it is unclear whether sleep slow oscillation by itself induces long-term plasticity that contributes to memory retention. Using in vivo prethalamic electrical stimulation at 1 Hz, which itself does not induce immediate potentiation of evoked responses, we investigated how the cortical evoked response was modulated by different states of vigilance. We found that somatosensory evoked potentials during wake were enhanced after a slow-wave sleep episode (with or without stimulation during sleep) as compared to a previous wake episode. In vitro, we determined that this enhancement has a postsynaptic mechanism that is calcium dependent, requires hyperpolarization periods (slow waves), and requires a coactivation of both AMPA and NMDA receptors. Our results suggest that long-term potentiation occurs during slow-wave sleep, supporting its contribution to memory.

Chauvette S; Seigneur J; Timofeev I

2012-09-01

323

Switched capacitor arrays analog memory for sparse data sampling  

International Nuclear Information System (INIS)

[en] 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)

1999-09-21

324

Long-term dependence in exchange rates  

Directory of Open Access Journals (Sweden)

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.

A. Karytinos; A. S. Andreou; G. Pavlides

1999-01-01

325

Long-term results after fibroid embolization  

International Nuclear Information System (INIS)

Fibroids (leiomyoma) are the most frequent benign tumors of the uterus during female reproductive age. In the case of clinical symptoms, uterine artery embolization (UAE) is a well established treatment option for symptomatic fibroids, resulting in promising long-term results. In order to estimate long-term success after UAE, reduction of fibroids and uterus volume is less important than complete improvement and disappearance of fibroid-related symptoms. In addition to a high technical success rate and a low perioperative complication rate, UAE results in high short-term and long-term patient satisfaction (>87%) and improvement of symptoms (>81%). Candidates for UAE should be informed about potential reinterventions in terms of repeated UAE (up to 18% of cases) or surgical treatment options. (orig.)

2008-01-01

326

Health problems and long-term unemployment.  

UK PubMed Central (United Kingdom)

The article deals with the relation between unemployment and health problems using as a case a local support project for long-term unemployed in northern Finland. Mass unemployment has increased competition on the labor market, and successful job-seekers must have a wider range of qualifications than before. As demands have intensified on the labor market, health has become a salient criterion in the recruitment process. At the same time the incidence of illness among long-term unemployed is surprisingly high. The situations of the project clients strongly indicate that health-related difficulties are one distinct risk factor for the long-term unemployed in finding work. We need new means for health promotion, more extensive psychosocial rehabilitation and local solutions for people who are unemployed.

Pohjola A

2001-01-01

327

Complications of long-term ventilation tubes.  

UK PubMed Central (United Kingdom)

OBJECTIVE: To demonstrate that ventilation tubes can remain in situ much longer than expected, and that the materials used in the manufacturing of these tubes can degrade and cause complications. Long-term follow up and replacement of the tube is recommended. METHOD: Case report and review of the literature concerning the use of long-term ventilation tubes. RESULTS: In the case reported, the ventilation tube was in place for 19 years, which resulted in chronic ear discharge. When it was removed, it was noted that the tube itself had degraded and had caused a chronic inflammatory reaction. CONCLUSION: We recommend that the long-term use of ventilation tubes is followed up and that the tube is replaced before material degradation takes place.

Mohammed H; Martinez-Devesa P

2013-05-01

328

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)

2005-01-01

329

Long-term Video-EEG Monitoring for Paroxysmal Events  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Long term video-electroencephalography monitoring (VEM) has been widelyused for the diagnosis, classification, and management of seizures. Fewstudies have systemically examined its safety issues and clinical utility. Thisprospective study investigates the general clinical application of long termVEM in the management of paroxysmal events.Methods: This study cohort consisted of patients admitted to the inpatient VEM unit atChang Gung Memorial Hospital (Lin-Kou). Standard 19 channel scalp electroencephalography(EEG), electrocardiography (ECG), and simultaneousvideo images were recorded continuously for 2 full days. Patient characteristics,and clinical, video-EEG and safety data were obtained and analyzed.The diagnosis and management of paroxysmal events before VEM werecompared with those after VEM.Results: Habitual events were recorded in 54.3% of the 129 patients, and VEM had ayield rate of 76% (events recorded or newly recorded interictal discharges) indetermining the nature of the events. Eleven patients had seizure clusters, butthere was no status epilepticus or electrode-related injury. After VEM, thediagnostic categories were changed in 41.1% of the patients, and 40.3% hadrevisions in management.Conclusions: Long term VEM is a safe diagnostic tool providing a high diagnostic yieldrate and directing adjustment of management for patients with paroxysmalevents.

Ying-Ying Lee; 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

330

Long-term characteristics of nuclear emulsion  

Energy Technology Data Exchange (ETDEWEB)

Long-term characteristics of the nuclear emulsion so called 'OPERA film' used in the neutrino oscillation experiment, OPERA, has been studied for 8 years since its production or refreshing after it. In the results, it turned out to be excellent in sensitivity, amount of random noise, and refreshing characteristics. The retention capacity of latent image of tracks was also studied. The result will open the way to the recycling of 7,000,000 emulsion films which will remain not developed after 5 years of OPERA's run, and other long-term experiments with emulsion.

Naganawa, N [Nagoya University, 464-8602 Nagoya (Japan); Kuwabara, K, E-mail: naganawa@flab.phys.nagoya-u.ac.j [Ashigara Research Laboratory, Fuji Photo Film Co., LTD, 250-0913 Minamiashigara (Japan)

2010-02-15

331

Long-term characteristics of nuclear emulsion  

International Nuclear Information System (INIS)

[en] Long-term characteristics of the nuclear emulsion so called 'OPERA film' used in the neutrino oscillation experiment, OPERA, has been studied for 8 years since its production or refreshing after it. In the results, it turned out to be excellent in sensitivity, amount of random noise, and refreshing characteristics. The retention capacity of latent image of tracks was also studied. The result will open the way to the recycling of 7,000,000 emulsion films which will remain not developed after 5 years of OPERA's run, and other long-term experiments with emulsion.

2010-01-01

332

Long term storage techniques for 85Kr  

International Nuclear Information System (INIS)

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

1974-08-12

333

Scenarios for long-term analysis  

Energy Technology Data Exchange (ETDEWEB)

Data Preservation and Long-Term Analysis of High Energy Physics (HEP) Experiments data is described and summarized in this talk. The summary covers information presented at the First Workshop on Data Preservation and Long-Term Analysis. Experiments representing e{sup +}e{sup -} collisions (LEP, B Factories and CLEO), ep collisions (H1 and ZEUS), p{bar p} collisions (CDF and D0) and others presented interesting information related to utilizing the large datasets collected over many years at these HEP facilities. Many questions and issues remain to be explored.

Wolbers, Stephen; /Fermilab

2009-01-01

334

Long-term consequences of foodborne infections.  

Science.gov (United States)

Foodborne infections with Campylobacter, E. coli O157:H7, Listeria monocytogenes, Salmonella, Shigella, Toxoplasma gondii, and other pathogens can result in long-term sequelae to numerous organ systems. These include irritable bowel syndrome, inflammatory bowel disease, reactive arthritis, hemolytic uremic syndrome, chronic kidney disease, Guillain-Barré Syndrome, neurological disorders from acquired and congenital listeriosis and toxoplasmosis, and cognitive and developmental deficits due to diarrheal malnutrition or severe acute illness. A full understanding of the long-term sequelae of foodborne infection is important both for individual patient management by clinicians, as well as to inform food safety and public health decision making. PMID:24011832

Batz, Michael B; Henke, Evan; Kowalcyk, Barbara

2013-07-25

335

Long-term consequences of foodborne infections.  

UK PubMed Central (United Kingdom)

Foodborne infections with Campylobacter, E. coli O157:H7, Listeria monocytogenes, Salmonella, Shigella, Toxoplasma gondii, and other pathogens can result in long-term sequelae to numerous organ systems. These include irritable bowel syndrome, inflammatory bowel disease, reactive arthritis, hemolytic uremic syndrome, chronic kidney disease, Guillain-Barré Syndrome, neurological disorders from acquired and congenital listeriosis and toxoplasmosis, and cognitive and developmental deficits due to diarrheal malnutrition or severe acute illness. A full understanding of the long-term sequelae of foodborne infection is important both for individual patient management by clinicians, as well as to inform food safety and public health decision making.

Batz MB; Henke E; Kowalcyk B

2013-09-01

336

[Fetal pain: immediate and long term consequences].  

UK PubMed Central (United Kingdom)

Several situations are potentially painful for fetuses, such as malformations and invasive procedures. Nociceptive pathways are known to be functional at 26 weeks. Even if it is not possible to evaluate the fetal experience of pain, it is essential to examine its immediate and long-term consequences. As early as the beginning of the second trimester, hemodynamic and hormonal responses are observed following fetal nociceptive stimulation, In experimental studies, long-term changes have been noted in the corticotrop axis, subsequent responses to pain, and behavior after perinatal nociceptive stimulation.

Houfflin Debarge V; Dutriez I; Pusniak B; Delarue E; Storme L

2010-06-01

337

Long-term dietary extra-virgin olive oil rich in polyphenols reverses age-related dysfunctions in motor coordination and contextual memory in mice: role of oxidative stress.  

Science.gov (United States)

The aim of this study was to evaluate the effects of olive oil phenols on brain aging in mice and to verify whether the antioxidant and antiinflammatory activities of these polyphenols were involved. C57Bl/6J mice were fed from middle age to senescence with extra-virgin olive oil (10% wt/wt dry diet) rich in phenols (total polyphenol dose/day, 6?mg/kg). Behavioral tests were employed to assess cognitive, motor, and emotional behavior after 6 or 12 months of treatment. Parameters of oxidative status and inflammation were measured in different brain areas at the same times and evaluated for correlation with behavioral changes. The treatment with olive oil phenols improved contextual memory in the step-down test to levels similar to young animals and prevented the age-related impairment in motor coordination in the rotarod test. This motor effect was correlated with reduced lipid peroxidation in the cerebellum (p<0.05), whereas the memory effect did not correlate with oxidation or inflammation parameters. In conclusion, this work points out that natural polyphenols contained in extra-virgin olive oil can improve some age-related dysfunctions by differentially affecting different brain areas. Such a modulation can be obtained with an olive oil intake that is normal in the Mediterranean area, provided that the oil has a sufficiently high content of polyphenols. PMID:22950431

Pitozzi, Vanessa; Jacomelli, Michela; Catelan, Dolores; Servili, Maurizio; Taticchi, Agnese; Biggeri, Annibale; Dolara, Piero; Giovannelli, Lisa

2012-11-16

338

Long-term dietary extra-virgin olive oil rich in polyphenols reverses age-related dysfunctions in motor coordination and contextual memory in mice: role of oxidative stress.  

UK PubMed Central (United Kingdom)

The aim of this study was to evaluate the effects of olive oil phenols on brain aging in mice and to verify whether the antioxidant and antiinflammatory activities of these polyphenols were involved. C57Bl/6J mice were fed from middle age to senescence with extra-virgin olive oil (10% wt/wt dry diet) rich in phenols (total polyphenol dose/day, 6?mg/kg). Behavioral tests were employed to assess cognitive, motor, and emotional behavior after 6 or 12 months of treatment. Parameters of oxidative status and inflammation were measured in different brain areas at the same times and evaluated for correlation with behavioral changes. The treatment with olive oil phenols improved contextual memory in the step-down test to levels similar to young animals and prevented the age-related impairment in motor coordination in the rotarod test. This motor effect was correlated with reduced lipid peroxidation in the cerebellum (p<0.05), whereas the memory effect did not correlate with oxidation or inflammation parameters. In conclusion, this work points out that natural polyphenols contained in extra-virgin olive oil can improve some age-related dysfunctions by differentially affecting different brain areas. Such a modulation can be obtained with an olive oil intake that is normal in the Mediterranean area, provided that the oil has a sufficiently high content of polyphenols.

Pitozzi V; Jacomelli M; Catelan D; Servili M; Taticchi A; Biggeri A; Dolara P; Giovannelli L

2012-12-01

339

Principles of long-term dynamics of dendritic spines.  

Science.gov (United States)

Long-term potentiation of synapse strength requires enlargement of dendritic spines on cerebral pyramidal neurons. Long-term depression is linked to spine shrinkage. Indeed, spines are dynamic structures: they form, change their shapes and volumes, or can disappear in the space of hours. Do all such changes result from synaptic activity, or do some changes result from intrinsic processes? How do enlargement and shrinkage of spines relate to elimination and generation of spines, and how do these processes contribute to the stationary distribution of spine volumes? To answer these questions, we recorded the volumes of many individual spines daily for several days using two-photon imaging of CA1 pyramidal neurons in cultured slices of rat hippocampus between postnatal days 17 and 23. With normal synaptic transmission, spines often changed volume or were created or eliminated, thereby showing activity-dependent plasticity. However, we found that spines changed volume even after we blocked synaptic activity, reflecting a native instability of these small structures over the long term. Such "intrinsic fluctuations" showed unique dependence on spine volume. A mathematical model constructed from these data and the theory of random fluctuations explains population behaviors of spines, such as rates of elimination and generation, stationary distribution of volumes, and the long-term persistence of large spines. Our study finds that generation and elimination of spines are more prevalent than previously believed, and spine volume shows significant correlation with its age and life expectancy. The population dynamics of spines also predict key psychological features of memory. PMID:19074033

Yasumatsu, Nobuaki; Matsuzaki, Masanori; Miyazaki, Takashi; Noguchi, Jun; Kasai, Haruo

2008-12-10

340

The effect of physical activity on long-term income.  

Science.gov (United States)

Empirical evidence for the direct effects of physical activities on long-term labor market outcomes is limited. This state of affairs is surprising, because there is a growing amount of support on the positive effects of physical activities on health on the one hand and on the effects of good health on labor market outcomes on the other hand. We examine the long-term income effects of physical activity using a large sample (N = 5042) of male twins from Finland (Older Finnish Twin Cohort Study, 1975, 1981, 1990), matched to detailed register-based income data (Finnish Longitudinal Employer-Employee Data, 1990-2004). Our primary income measure is calculated over a fifteen-year period and it covers the prime working age of the twins that we study. We use the twin dimension of the data to control for unobservable genetic and family confounding factors. Our within-twin estimates show that being physically active has a positive impact on the long-term income. We argue that our results are not easily reconciled with the intuitive explanation of physical activity enhancing long-term income via health or more intense labor market attachment. We reason that instead, there may be various non-cognitive mechanisms at work: Physical activity can, for example, make people more persistent in the face of work-related difficulties and increase their desire to partake in competitive situations, with greater expected pecuniary rewards. PMID:24034960

Hyytinen, Ari; Lahtonen, Jukka

2013-08-06

 
 
 
 
341

The effect of physical activity on long-term income.  

UK PubMed Central (United Kingdom)

Empirical evidence for the direct effects of physical activities on long-term labor market outcomes is limited. This state of affairs is surprising, because there is a growing amount of support on the positive effects of physical activities on health on the one hand and on the effects of good health on labor market outcomes on the other hand. We examine the long-term income effects of physical activity using a large sample (N = 5042) of male twins from Finland (Older Finnish Twin Cohort Study, 1975, 1981, 1990), matched to detailed register-based income data (Finnish Longitudinal Employer-Employee Data, 1990-2004). Our primary income measure is calculated over a fifteen-year period and it covers the prime working age of the twins that we study. We use the twin dimension of the data to control for unobservable genetic and family confounding factors. Our within-twin estimates show that being physically active has a positive impact on the long-term income. We argue that our results are not easily reconciled with the intuitive explanation of physical activity enhancing long-term income via health or more intense labor market attachment. We reason that instead, there may be various non-cognitive mechanisms at work: Physical activity can, for example, make people more persistent in the face of work-related difficulties and increase their desire to partake in competitive situations, with greater expected pecuniary rewards.

Hyytinen A; Lahtonen J

2013-11-01

342

Long-term fertilizer containing nitrogen  

UK PubMed Central (United Kingdom)

A long-term fertilizer containing nitrogen, contains a mixture of acetylene diurea and at least one other organic fertilizer containing nitrogen, such as methylene urea, isobutylidene diurea, crotonylidene diurea, oxamide, melamine, substituted triazones, ethylene diurea, triuret or mixtures of them.

HORCHLER KLAUS; WISSEMEIER ALEXANDER; HAHNDEL REINHARD; CZIKKELY VILMOS; WEIGELT WOLFGANG; ZERULLA WOLFRAM

343

Models for delivering long term care.  

UK PubMed Central (United Kingdom)

Five models are presented for delivering Long Term Care to frail elderly persons. The framework uses basic microeconomic concepts to describe different incentives at work in the five models. Unique features of each model are described and clinical studies reviewed suggesting when a particular option might the most appropriate. Additional research questions are raised by the framework.

Lubben JE

1987-01-01

344

Long term prospects for double beta decay  

CERN Multimedia

In rather general terms the long term perspective of double beta decay is discussed. All important experimental parameters are investigated as well as the status of nuclear matrix element issues. The link with other neutrino physics results and options to disentangle the underlying physics process are presented.

Zuber, K

2010-01-01

345

Long-Term Stability of Social Participation  

Science.gov (United States)

The long-term stability of social participation was investigated in a representative urban population of 415 men and 579 women who had taken part in the nationwide Mini-Finland Health Survey in the years 1978-1980 and were re-examined 20 years later. Stability was assessed by means of the following tracking coefficients: kappa, proportion of…

Hyyppa, Markku T.; Maki, Juhani; Alanen, Erkki; Impivaara, Olli; Aromaa, Arpo

2008-01-01

346

Long-Term Care -- Actuarial Cost Estimates.  

Science.gov (United States)

The areas covered by this paper, which is designed to help Congress in its deliberations on changes in existing programs, include: (1) the demand for long-term health and social services; (2) the existing supply of the services; and (3) the cost of certai...

1977-01-01

347

Eta Carinae long-term variability  

CERN Multimedia

We present preliminary results of our analysis on the long-term variations observed in the optical spectrum of the LBV star Eta Carinae. Based on the hydrogen line profiles, we conclude that the physical parameters of the primary star did not change in the last 15 years.

Damineli, A; Corcoran, M; Groh, J H

2010-01-01

348

Pituitary diseases : long-term psychological consequences  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Nowadays, pituitary adenomas can be appropriately treated, but patients continue to report impaired quality of life (QoL) despite long-term remission or cure. In patients with Cushing’s disease, Cushing’s syndrome or acromegaly, doctors should be aware of subtle cognitive impairments and the increa...

Tiemensma, Jitske

349

JAXA's Long Term Vision in Science  

International Nuclear Information System (INIS)

Japan Aerospace Exploration Agency (JAXA) has been founded as a result of the integration of three space related institutions. JAXA's long term vision was defined in 2005 as the proposal on its initiative and provides the ideal situation of aerospace in the next 20 years. Space science is clearly defined as one of important categories in future.

2007-01-01

350

Long-term solar-terrestrial observations  

Energy Technology Data Exchange (ETDEWEB)

In the fall of 1985, the Committee on Solar-Terrestrial Research (CSTR) created a panel to study the requirements for long-term monitoring and archiving of solar-terrestrial data. The panel comprised specialists in all four areas that constitute solar-terrestrial science: the sun, interplanetary medium, magnetosphere-thermosphere-ionosphere, and upper atmosphere. It interviewed many individuals from the solar-terrestrial monitoring and data archiving communities, along with administrators and directors from appropriate government agencies. It circulated nearly 500 questionnaires to obtain information and opinions from the broader community to learn which observational data should be considered essential over the long term to support the operational and research needs of solar-terrestrial science. This report summarizes the panel's principal findings, and the panel's recommendations follow. A separate section listing the critical observational needs by area is presented together with the scientific rationale for each area. The recommendations are defended in terms of this explicit scientific rationale and the multifold uses of current and long-term solar-terrestrial observations for continued operational solar-terrestrial forecasts and services. Finally, the panel addresses the question of setting priorities among the critical set of observations during periods of low or declining scientific budgets. Here the most important criterion is the recognition that the field must allocate funding to support new research at the same time that it is acquiring the high-priority data sets over the long term.

1988-01-01

351

Long-term survival following pneumococcal pneumonia.  

UK PubMed Central (United Kingdom)

We studied the long-term survival of patients who recovered from pneumococcal pneumonia. Mortality was increased for up to 10 years after documented pneumococcal pneumonia and was greater in proportion to the PORT score at admission and among persons who had bacteremic disease.

Sandvall B; Rueda AM; Musher DM

2013-04-01

352

Toward a comprehensive long term nicotine policy  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Global tobacco deaths are high and rising. Tobacco use is primarily driven by nicotine addiction. Overall tobacco control policy is relatively well agreed upon but a long term nicotine policy has been less well considered and requires further debate. Reaching consensus is important because a nicot...

Gray, N; Henningfield, J; Benowitz, N; Connolly, G; Dresler, C; Fagerstrom, K; Jarvis, M; Boyle, P

353

Long-term future energy supply  

International Nuclear Information System (INIS)

The paper exposes the long-term future energy supply within a demand side expectation which, though modest, is well in excess of the average 0.75% growth rate of the 1990s. Recent important changes on both the supply and demand sides have created the prospect for a highly sustainable energy future well into the second half of this century.

2001-01-01

354

Long-term survival after perforated diverticulitis.  

UK PubMed Central (United Kingdom)

AIM: Short-term survival after emergency surgery for perforated diverticulitis is poor. Less is known about long-term survival. The aims of this study were to evaluate long-term survival after discharge from hospital and to identify factors associated with prognosis. METHOD: All patients who underwent emergency surgery for perforated diverticulitis in five hospitals in Rotterdam, the Netherlands, between 1990 and 2005, were included. The association between type of surgery (Hartmann's procedure or primary anastomosis) and long-term survival was analysed using multivariate Cox regression analysis, taking into account age American Society of Anesthesiology (ASA) classification, Hinchey score, Mannheim Peritonitis Index (MPI) and surgeon's experience. In addition, survival of the patients was compared with that of the matched general Dutch population. RESULTS: Of 340 patients included in the study, 250 were discharged alive from hospital. The overall 5-year survival was 53%. Survival was significantly impaired compared with the expected matched gender-, age- and calendar time-specific survival. Overall survival was significantly related to age and ASA classification. Hinchey score, MPI, number of re-interventions, the surgeon's experience and type of procedure did not influence long-term survival, although a trend was found for Hartmann's procedure to be a risk factor for poorer survival compared with primary anastomosis (hazard ratio for mortality: 1.88; 95% confidence interval, 0.96-3.67; P = 0.07). CONCLUSION: Long-term survival of patients after perforated diverticulitis is limited and mainly caused by the poor general condition of the patients, rather than by the severity of the primary disease or calendar-time and type of procedure.

Vermeulen J; Gosselink MP; Hop WC; van der Harst E; Hansen BE; Mannaerts GH; Coene PP; Weidema WF; Lange JF

2011-02-01

355

Long-term consequences of severe infections.  

UK PubMed Central (United Kingdom)

There are convincing data to show that the consequences of a severe infection extend well beyond the first month following it. During the first year after severe sepsis or infection, the survival of sepsis patients is guarded compared with matched control groups. Their quality of life is impaired, and they suffer from rapid degradation in cognition and functional capacity. We could postulate three explanations for the long-term bad outcomes of severe infections and sepsis (or a combination of the three): (i) sepsis usually happens in the elderly and sick, and it causes deterioration in life expectancy and functional status as an acute, non-specific event; (ii) an interaction between specific mechanisms of sepsis and underlying disorders; or (iii) long-term complications directly related to infection. If the second or third explanations are true, then management of the original infection/sepsis might have an influence on long-term outcomes. Elderly survivors of severe infections should be carefully assessed for whether they need intermediate care for recuperation and re-conditioning when leaving hospital. We need prospective, observational studies to define which are the factors that most influence long-term outcomes, and especially management of the acute infection. The investigation of long-term outcomes in trials of treatment modalities for sepsis or severe infections should be encouraged. The true answer for whether one treatment is better than another in severe infections or sepsis lies in the people trajectory in the year following the infection, and not only on 4-6 weeks outcome.

Leibovici L

2013-06-01

356

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

International Nuclear Information System (INIS)

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)

1998-01-01

357

Data of long term atmospheric diffusion experiments (Summer, 1992)  

International Nuclear Information System (INIS)

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)

1998-01-01

358

Data of long term atmospheric diffusion experiments (autumn, 1991)  

Energy Technology Data Exchange (ETDEWEB)

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)

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

1998-10-01

359

Data of long term atmospheric diffusion experiments (Summer, 1992)  

Energy Technology Data Exchange (ETDEWEB)

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)

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

1998-10-01

360

Data of long term atmospheric diffusion experiments (spring, 1992)  

Energy Technology Data Exchange (ETDEWEB)

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)

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

1998-10-01

 
 
 
 
361

[Bariatric surgery - significance, risks, long term consequences].  

UK PubMed Central (United Kingdom)

In recent years the number of bariatric surgery has markedly increased in industrial nations. Surgery provides a more rapid decrease of body weight than conservative approach. However a long term conservative follow up therapy is mandatory to stabilize reduced weight. Due to increasing knowledge from long term follow up of surgically treated obese patients there is a growing body of evidence that frequently there is necessity of reoperations and of substitution both of trace elementsand of minerals or vitamins due to their hampered enteral resorption. Additionally therapy of surgery induced endocrine alterations not seldom is necessary.These insights are of outstanding importance because meanwhile an enlargement of the indications for bariatric surgery as a therapeutic option for metabolic disorders is being discussed. This review refers to the recent internationally published papers concerning consequences of bariatric surgery.

Schubert T; Jahn U; Eben E; Deuber HJ

2013-03-01

362

INTELLIGENT SYSTEM FOR LONG TERM LOAD FORECASTING  

Directory of Open Access Journals (Sweden)

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.

Neha Kapoor; Gopal Krishan; Roohi Kapoor

2011-01-01

363

Analysis of long-term energy scenarios  

Energy Technology Data Exchange (ETDEWEB)

When addressing the role of fusion energy in the 21. century, the evaluation of possible future structures in the electricity market and the energy sector as a whole, can be a useful tool. Because fusion energy still needs demonstration, commercialized fusion energy is not likely to be a reality within the next few decades. Therefore long-term scenarios are needed describing the energy markets, which fusion energy eventually will be part of. This report performs an analysis of two of the most detailed existing long-term scenarios describing possible futures of the energy system. The aim is to clarify the frames in which the future development of the global energy demand, as well as the structure of the energy system can be expected to develop towards the year 2100. (au) 19 refs.

Lemming, J.; Morthorst, P.E.

1998-09-01

364

Quantifying Long-term Scientific Impact  

CERN Document Server

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.

Wang, Dashun; Barabási, Albert-László

2013-01-01

365

Long-term Treatment in Bipolar Disorder  

Directory of Open Access Journals (Sweden)

Full Text Available Although the importance of long-term prophylactic treatment is certain in bipolar disorder, there is stil debate on how to which patients and evaluate the treatment response. Efficacious long-term treatment can reduce morbidity and mortality significantly and improve quality of life of bipolar patients. The concept of ideal response should also be defined very clearly in order to discuss the difficulties of measuring the effectiveness of the prophylactic treatment. The aims of this paper are to determine whether our currently methods and criteria are valid, reliable and sensitive evaluating the efficacy of the treatment response and to briefly inform the clinicians about the drugs used in pharmacologic prophylaxis in accordance with relevant data.

Meliha Zengin Eroglu; Nurgul Ozpoyraz

2010-01-01

366

Long-term study measures radon  

Science.gov (United States)

Preliminary results from a long-term study of indoor radon levels will be presented on Tuesday, May 19, at the AGU Spring Meeting in Baltimore, Md. The study, which is still in progress, has already pointed to some possible links between levels of radon gas in homes and local geology and home construction, according to Douglas Mose and George Mushrush of George Mason University (Fairfax, Va.).

Katzoff, Judith A.

367

Long-term outlook for electric demand  

Energy Technology Data Exchange (ETDEWEB)

Utilities are showing more willingness to let lower demand forecasts reflect unfavorable economic conditions, but they may now be overreacting to short-term situations. Long-term growth estimates based on demand estimates of real rates and real gross national product (GNP) suggest a demand growth of 4.5 and 5% per year, given a 3% growth in real GNP and a 2% growth in electric rates, and not the 2.5% estimated by the utility industry. (DCK)

Studness, C.M.

1983-09-15

368

Long-term sequelae of electrical injury  

Science.gov (United States)

Abstract Objective To summarize the current evidence-based knowledge about the long-term sequelae of injuries from electrical current. Quality of evidence MEDLINE was searched for English-language articles published in the past 20 years using the following search terms: electrical, injuries, wound, trauma, accident, sequelae, long-term, follow-up, and aftereffects. For obvious reasons, it is unethical to randomly study electrical injury in controlled clinical trials. By necessity, this topic is addressed in less-rigorous observational and retrospective work and case studies. Therefore, the strength of the literature pertaining to the long-term sequelae of electrical injury is impaired by the necessity of retrospective methods and case studies that typically describe small cohorts. Main message There are 2 possible consequences of electrical injury: the person either survives or dies. For those who survive electrical injury, the immediate consequences are usually obvious and often require extensive medical intervention. The long-term sequelae of the electrical injury might be more subtle, pervasive, and less well defined, but can include neurologic, psychological, and physical symptoms. In the field of compensation medicine, determining causation and attributing outcome to an injury that might not result in objective clinical findings becomes a considerable challenge. Conclusion The appearance of these consequences of electrical injury might be substantially delayed, with onset 1 to 5 or more years after the electrical injury. This poses a problem for patients and health care workers, making it hard to ascribe symptoms to a remote injury when they might not arise until well after the incident event.

Wesner, Marni L.; Hickie, John

2013-01-01

369

Long-term sequelae of electrical injury.  

UK PubMed Central (United Kingdom)

OBJECTIVE: To summarize the current evidence-based knowledge about the long-term sequelae of injuries from electrical current. QUALITY OF EVIDENCE: MEDLINE was searched for English-language articles published in the past 20 years using the following search terms: electrical, injuries, wound, trauma, accident, sequelae, long-term, follow-up, and aftereffects. For obvious reasons, it is unethical to randomly study electrical injury in controlled clinical trials. By necessity, this topic is addressed in less-rigorous observational and retrospective work and case studies. Therefore, the strength of the literature pertaining to the long-term sequelae of electrical injury is impaired by the necessity of retrospective methods and case studies that typically describe small cohorts. MAIN MESSAGE: There are 2 possible consequences of electrical injury: the person either survives or dies. For those who survive electrical injury, the immediate consequences are usually obvious and often require extensive medical intervention. The long-term sequelae of the electrical injury might be more subtle, pervasive, and less well defined, but can include neurologic, psychological, and physical symptoms. In the field of compensation medicine, determining causation and attributing outcome to an injury that might not result in objective clinical findings becomes a considerable challenge. CONCLUSION: The appearance of these consequences of electrical injury might be substantially delayed, with onset 1 to 5 or more years after the electrical injury. This poses a problem for patients and health care workers, making it hard to ascribe symptoms to a remote injury when they might not arise until well after the incident event.

Wesner ML; Hickie J

2013-09-01

370

Long-term outcomes after laparoscopic colectomy  

Directory of Open Access Journals (Sweden)

Full Text Available AIM: To evaluate long-term outcomes in a large series of patients who randomly received laparoscopic or open colorectal resection.METHODS: From February 2000 to December 2004, six hundred sixty-two patients with colorectal disease were randomly assigned to laparoscopic (LPS, n = 330) or open (n = 332) colorectal resection. All patients were analyzed on an intention-to-treat basis. Long-term follow-up was carried out every 6 mo by office visits. In 526 cancer patients five-year overall and disease-free survival were evaluated. Median oncologic follow-up was 96 mo.RESULTS: Eight (4.2%) LPS group patients needed conversion to open surgery. Overall long-term morbidity rate was 7.6% (25/330) in the LPS vs 11.1% (37/332) in the open group (P = 0.17). In cancer patients, five-year overall survival was 68.6% in the LPS group and 64.0% in the Open group (P = 0.27). Excluding stage IV patients, five-year local and distant recurrence rates were 32.5% in the LPS group and 36.8% in the Open group (P = 0.36). Further, no difference in recurrence rate was found when patients were stratified according to cancer stage.CONCLUSION: LPS colorectal resection was associated with a slightly lower incidence of long-term complications than open surgery. No difference between groups was found in overall and disease-free survival rates.

Marco Braga, Nicolò Pecorelli, Matteo Frasson, Andrea Vignali, Walter Zuliani, Valerio Di Carlo

2011-01-01

371

Long-term Treatment in Multiple Sclerosis  

Directory of Open Access Journals (Sweden)

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)

Derya ULUDÜZ; Sabahattin SA?P; Aksel S?VA

2008-01-01

372

Electrodes for long-term esophageal electrocardiography.  

Science.gov (United States)

The emerging application of long-term and high-quality ECG recording requires alternative electrodes to improve the signal quality and recording capability of surface skin electrodes. The esophageal ECG has the potential to overcome these limitations but necessitates novel recorder and lead designs. The electrode material is of particular interest, since the material has to ensure conflicting requirements like excellent biopotential recording properties and inertness. To this end, novel electrode materials like PEDOT and silver-PDMS as well as established electrode materials such as stainless steel, platinum, gold, iridium oxide, titanium nitride, and glassy carbon were investigated by long-term electrochemical impedance spectroscopy and model-based signal analysis using the derived in vitro interfacial properties in conjunction with a dedicated ECG amplifier. The results of this novel approach show that titanium nitride and iridium oxide featuring microstructured surfaces did not degrade when exposed to artificial acidic saliva. These materials provide low electrode potential drifts and insignificant signal distortion superior to surface skin electrodes making them compatible with accepted standards for ambulatory ECG. They are superior to the noble and polarizable metals such as platinum, silver, and gold that induced more signal distortions and are superior to esophageal stainless steel electrodes that corrode in artificial saliva. The study provides rigorous criteria for the selection of electrode materials for prolonged ECG recording by combining long-term in vitro electrode material properties with ECG signal quality assessment. PMID:23649132

Niederhauser, Thomas; Haeberlin, Andreas; Marisa, Thanks; Jungo, Michael; Goette, Josef; Jacomet, Marcel; Abacherli, Roger; Vogel, Rolf

2013-05-01

373

Long-term solar-terrestrial observations  

Science.gov (United States)

In the fall of 1985, the Committee on Solar-Terrestrial Research (CSTR) created a panel to study the requirements for long-term monitoring and archiving of solar-terrestrial data. The panel comprised specialists in all four areas that constitute solar-terrestrial science: the sun, interplanetary medium, magnetosphere-thermosphere-ionosphere, and upper atmosphere. It interviewed many individuals from the solar-terrestrial monitoring and data archiving communities, along with administrators and directors from appropriate government agencies. It circulated nearly 500 questionnaires to obtain information and opinions from the broader community to learn which observational data should be considered essential over the long term to support the operational and research needs of solar-terrestrial science. This report summarizes the panel's principal findings, and the panel's recommendations follow. A separate section listing the critical observational needs by area is presented together with the scientific rationale for each area. The recommendations are defended in terms of this explicit scientific rationale and the multifold uses of current and long-term solar-terrestrial observations for continued operational solar-terrestrial forecasts and services.

374

Electrodes for long-term esophageal electrocardiography.  

UK PubMed Central (United Kingdom)

The emerging application of long-term and high-quality ECG recording requires alternative electrodes to improve the signal quality and recording capability of surface skin electrodes. The esophageal ECG has the potential to overcome these limitations but necessitates novel recorder and lead designs. The electrode material is of particular interest, since the material has to ensure conflicting requirements like excellent biopotential recording properties and inertness. To this end, novel electrode materials like PEDOT and silver-PDMS as well as established electrode materials such as stainless steel, platinum, gold, iridium oxide, titanium nitride, and glassy carbon were investigated by long-term electrochemical impedance spectroscopy and model-based signal analysis using the derived in vitro interfacial properties in conjunction with a dedicated ECG amplifier. The results of this novel approach show that titanium nitride and iridium oxide featuring microstructured surfaces did not degrade when exposed to artificial acidic saliva. These materials provide low electrode potential drifts and insignificant signal distortion superior to surface skin electrodes making them compatible with accepted standards for ambulatory ECG. They are superior to the noble and polarizable metals such as platinum, silver, and gold that induced more signal distortions and are superior to esophageal stainless steel electrodes that corrode in artificial saliva. The study provides rigorous criteria for the selection of electrode materials for prolonged ECG recording by combining long-term in vitro electrode material properties with ECG signal quality assessment.

Niederhauser T; Haeberlin A; Marisa T; Jungo M; Goette J; Jacome