48 CFR 211.275 - Passive radio frequency identification.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Passive radio frequency identification. 211.275 Section 211.275 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS... Requirements Documents 211.275 Passive radio frequency identification. ...

Acute Effects of Ecstasy on Memory Are more Extensive than Chronic Effects

PubMed Central

Shariati, Mohamad Bakhtiar Hesam; Sohrabi, Maryam; Shahidi, Siamak; Nikkhah, Ali; Mirzaei, Fatemeh; Medizadeh, Mehdi; Asl, Sara Soleimani

2014-01-01

Introduction Exposure to 3, 4- methylenedioxymethamphetamine (MDMA) could lead to serotonergic system toxicity in the brain. This system is responsible for learning and memory functions. Studies show that MDMA causes memory impairment dose-dependently and acutely. The present study was designed to evaluate the chronic and acute effects of MDMD on spatial memory and acquisition of passive avoidance. Methods Adult male Wistar rats (200-250 g) were given single or multiple injections of MDMA (10 mg/kg, IP). Using passive avoidance and Morris Water Maze (MWM) tasks, learning and spatial memory functions were assessed. The data were analyzed by SPSS 16 software and one- way analysis of variance (ANOVA) test. Results Our results showed that there were significant differences in latency to enter the dark compartment (STL) between sham and MDMA- treated groups. Acute group significantly showed more STL in comparison with chronic group. Furthermore, MDMA groups spent more time in dark compartment (TDS) than the sham group. Administration of single dose of MDMA significantly caused an increase in TDS compared with the chronic group. In the MWM, MDMA treatment significantly increased the traveled distance and escaped latency compared to the sham group. Like to passive avoidance task, percentage of time spent in the target quadrant in MDMA- treated animals impaired in MWM compared with sham group. Discussion These data suggest that MDMA treatment impairs learning and memory functions that are more extensive in acute- treated rats. PMID:25337384

Effect of pregabalin on fear-based conditioned avoidance learning and spatial learning in a mouse model of scopolamine-induced amnesia.

PubMed

Sałat, Kinga; Podkowa, Adrian; Malikowska, Natalia; Trajer, Jędrzej

2017-03-01

Cognitive deficits are one of the frequent symptoms accompanying epilepsy or its treatment. In this study, the effect on cognition of intraperitoneally administered antiepileptic drug, pregabalin (10 mg/kg), was investigated in scopolamine-induced memory-impaired mice in the passive avoidance task and Morris water maze task. The effect of scopolamine and pregabalin on animals' locomotor activity was also studied. In the retention phase of the passive avoidance task, pregabalin reversed memory deficits induced by scopolamine (p < 0.05). During the acquisition phase of the Morris water maze pregabalin-treated memory-impaired mice performed the test with longer escape latencies than the vehicle-treated mice (significant at p < 0.05 on Day 5, and at p < 0.001 on Day 6). There were no differences in this parameter between the scopolamine-treated control group and pregabalin-treated memory-impaired mice, which indicated that pregabalin had no influence on spatial learning in this task. During the probe trial a significant difference (p < 0.05) was observed in terms of the mean number of target crossings between vehicle-treated mice and pregabalin-treated memory-impaired mice but there was no difference between the scopolamine-treated control group and mice treated with pregabalin + scopolamine. Pregabalin did not influence locomotor activity increased by scopolamine. In passive avoidance task, pregabalin reversed learning deficits induced by scopolamine. In the Morris water maze, pregabalin did not influence spatial learning deficits induced by scopolamine. These results are relevant for epileptic patients treated with pregabalin and those who use it for other therapeutic indications (anxiety, pain).

Four dimensional hybrid ultrasound and optoacoustic imaging via passive element optical excitation in a hand-held probe

NASA Astrophysics Data System (ADS)

Fehm, Thomas Felix; Deán-Ben, Xosé Luís; Razansky, Daniel

2014-10-01

Ultrasonography and optoacoustic imaging share powerful advantages related to the natural aptitude for real-time image rendering with high resolution, the hand-held operation, and lack of ionizing radiation. The two methods also possess very different yet highly complementary advantages of the mechanical and optical contrast in living tissues. Nonetheless, efficient integration of these modalities remains challenging owing to the fundamental differences in the underlying physical contrast, optimal signal acquisition, and image reconstruction approaches. We report on a method for hybrid acquisition and reconstruction of three-dimensional pulse-echo ultrasound and optoacoustic images in real time based on passive ultrasound generation with an optical absorber, thus avoiding the hardware complexity of active ultrasound generation. In this way, complete hybrid datasets are generated with a single laser interrogation pulse, resulting in simultaneous rendering of ultrasound and optoacoustic images at an unprecedented rate of 10 volumetric frames per second. Performance is subsequently showcased in phantom experiments and in-vivo measurements from a healthy human volunteer, confirming general clinical applicability of the method.

Four dimensional hybrid ultrasound and optoacoustic imaging via passive element optical excitation in a hand-held probe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fehm, Thomas Felix; Razansky, Daniel, E-mail: dr@tum.de; Faculty of Medicine, Technische Universität München, Munich

2014-10-27

Ultrasonography and optoacoustic imaging share powerful advantages related to the natural aptitude for real-time image rendering with high resolution, the hand-held operation, and lack of ionizing radiation. The two methods also possess very different yet highly complementary advantages of the mechanical and optical contrast in living tissues. Nonetheless, efficient integration of these modalities remains challenging owing to the fundamental differences in the underlying physical contrast, optimal signal acquisition, and image reconstruction approaches. We report on a method for hybrid acquisition and reconstruction of three-dimensional pulse-echo ultrasound and optoacoustic images in real time based on passive ultrasound generation with an opticalmore » absorber, thus avoiding the hardware complexity of active ultrasound generation. In this way, complete hybrid datasets are generated with a single laser interrogation pulse, resulting in simultaneous rendering of ultrasound and optoacoustic images at an unprecedented rate of 10 volumetric frames per second. Performance is subsequently showcased in phantom experiments and in-vivo measurements from a healthy human volunteer, confirming general clinical applicability of the method.« less

Fatty acid amide hydrolase (FAAH) inhibition enhances memory acquisition through activation of PPAR-α nuclear receptors

PubMed Central

Mazzola, Carmen; Medalie, Julie; Scherma, Maria; Panlilio, Leigh V.; Solinas, Marcello; Tanda, Gianluigi; Drago, Filippo; Cadet, Jean Lud; Goldberg, Steven R.; Yasar, Sevil

2009-01-01

Inhibitors of fatty acid amide hydrolase (FAAH) increase endogenous levels of anandamide (a cannabinoid CB1-receptor ligand) and oleoylethanolamide and palmitoylethanolamide (OEA and PEA, ligands for α-type peroxisome proliferator-activated nuclear receptors, PPAR-α) when and where they are naturally released in the brain. Using a passive-avoidance task in rats, we found that memory acquisition was enhanced by the FAAH inhibitor URB597 or by the PPAR-α agonist WY14643, and these enhancements were blocked by the PPAR-α antagonist MK886. These findings demonstrate novel mechanisms for memory enhancement by activation of PPAR-α, either directly by administering a PPAR-α agonist or indirectly by administering a FAAH inhibitor. PMID:19403796

Prior fear conditioning does not impede enhanced active avoidance in serotonin transporter knockout rats.

PubMed

Schipper, Pieter; Henckens, Marloes J A G; Borghans, Bart; Hiemstra, Marlies; Kozicz, Tamas; Homberg, Judith R

2017-05-30

Stressors can be actively or passively coped with, and adequate adaption of the coping response to environmental conditions can reduce their potential deleterious effects. One major factor influencing stress coping behaviour is serotonin transporter (5-HTT) availability. Abolishment of 5-HTT is known to impair fear extinction but facilitates acquisition of signalled active avoidance (AA), a behavioural task in which an animal learns to avoid an aversive stimulus that is predicted by a cue. Flexibility in adapting coping behaviour to the nature of the stressor shapes resilience to stress-related disorders. Therefore, we investigated the relation between 5-HTT expression and ability to adapt a learned coping response to changing environmental conditions. To this end, we first established and consolidated a cue-conditioned passive fear response in 5-HTT -/- and wildtype rats. Next, we used the conditioned stimulus (CS) to signal oncoming shocks during signalled AA training in 5-HTT -/- and wildtype rats to study their capability to acquire an active coping response to the CS following fear conditioning. Finally, we investigated the behavioural response to the CS in a novel environment and measured freezing, exploration and self-grooming, behaviours reflective of stress coping strategy. We found that fear conditioned and sham conditioned 5-HTT -/- animals acquired the signalled AA response faster than wildtypes, while prior conditioning briefly delayed AA learning similarly in both genotypes. Subsequent exposure to the CS in the novel context reduced freezing and increased locomotion in 5-HTT -/- compared to wildtype rats. This indicates that improved AA performance in 5-HTT -/- rats resulted in a weaker residual passive fear response to the CS in a novel context. Fear conditioning prior to AA training did not affect freezing upon re-encountering the CS, although it did reduce locomotion in 5-HTT -/- rats. We conclude that independent of 5-HTT signalling, prior fear conditioning does not greatly impair the acquisition of subsequent active coping behaviour when the situation allows for it. Abolishment of 5-HTT results in a more active coping style in case of novelty-induced fear and upon CS encounter in a novel context after AA learning. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of cholestasis on learning and locomotor activity in bile duct ligated rats.

PubMed

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

2014-01-01

Cognitive functions are impaired in patients with liver disease. Bile duct ligation causes cholestasis that impairs liver function. This study investigated the impact of cholestasis progression on the acquisition and retention times in the passive avoidance test and on the locomotor activity of rats. Cholestasis was induced in male Wistar rats by ligating the main bile duct. Locomotor activity, learning and memory were assessed by the passive avoidance learning test at day 7, day 14, and day 21 post-bile duct ligation. The serum levels of bilirubin, alanine aminotransferase, and alkaline phosphatase were measured. The results showed that acquisition time and locomotor activity were not affected at day 7 and day 14, but they were significantly (P < 0.05) impaired at day 21 post-bile duct ligation compared with the results for the control group. Additionally, memory was significantly impaired on day 7 (P < 0.01), day 14, and day 21 (P < 0.001) compared with the control groups. The levels of total bilirubin, direct bilirubin, indirect bilirubin, alanine aminotransferase, and alkaline phosphatase were significantly higher at day 7, day 14, and day 21 post-bile duct ligation compared with the levels in the sham group. Based on these findings, both liver and memory function were affected in the early stage of cholestasis (7 days after bile duct ligation), while learning and locomotor activity were impaired at 21 days after bile duct ligation following the progression of cholestasis.

The effect of para-chlorophenylalanine and scopolamine on passive avoidance in chicks.

PubMed

Mattingly, B A; Zolman, J F

1981-05-01

Four-day-old Vantress x Arbor Acre chicks were treated for key-peck passive avoidance (PA) learning following intraperitoneal injections of parachlorophenylalanine (PCPA) and/or scopolamine. In Experiment 1, chicks were pre-treated with either three or five injections of PCPA (150 mg/kg) or saline across th first three posthatch days and then tested for PA learning on the fourth posthatch day. In Experiment 2, chicks were first pre-treated with three injections of PCPA (150 mg/kg) or saline, and then injected with either scopolamine (0.5 mg/kg) or saline 20 min prior to PA testing on the fourth posthatch day. Major findings were: (a) Chicks pre-treated with PCPA did not significantly differ from saline control chicks in either the acquisition or maintenance of response suppression during PA testing; (b) chicks injected with scopolamine were significantly disrupted in PA learning as compared to saline control chicks; and (c) PCPA pre-treatment did not significantly affect the scopolamine-induced disruption of PA learning. These findings, therefore, suggest that cholinergic, but not serotonergic, mechanisms are involved in PA learning of the young chick.

Spatial learning in rats: correlation with cortical choline acetyltransferase and improvement with NGF following NBM damage.

PubMed

Mandel, R J; Gage, F H; Thal, L J

1989-06-01

Rats display an acquisition deficit in a circular water maze following excitotoxic lesions of the nucleus basalis magnocellularis (NBM). Experiments were therefore performed to determine if acquisition behavior on this task could predict the degree of cortical cholinergic deafferentation and if the acquisition deficit could be pharmacologically reversed. Performance on acquisition was highly correlated with the lesion-induced reduction in cortical choline acetyltransferase (ChAT) activity. Accuracy of spatial behavior was highly correlated to percentage ChAT depletion (r = 0.75). Neither lesioned rats nor controls displayed a retention deficit after a 9-day interval, nor did either group display a passive-avoidance retention deficit. To test the causal relationship between cholinergic dysfunction and spatial behavior, the central nervous system cholinergic enhancer nerve growth factor (NGF) was intraventricularly infused for 4 weeks. NGF infusion resulted in improved acquisition of the water maze task compared to NBM-lesioned rats receiving vehicle infusion and untreated rats with NBM lesions. These studies indicate that the decrease in cortical ChAT activity is likely to be responsible for the observed acquisition deficit and that pharmacological manipulations can be successfully used to improve behavior following NBM lesions.

On the Second Language Acquisition of Spanish Reflexive Passives and Reflexive Impersonals by French- and English-Speaking Adults

ERIC Educational Resources Information Center

Tremblay, Annie

2006-01-01

This study, a partial replication of Bruhn de Garavito (1999a; 1999b), investigates the second language (L2) acquisition of Spanish reflexive passives and reflexive impersonals by French- and English-speaking adults at an advanced level of proficiency. The L2 acquisition of Spanish reflexive passives and reflexive impersonals by native French and…

Long-term moderate treadmill exercise promotes stress-coping strategies in male and female rats.

PubMed

Lalanza, Jaume F; Sanchez-Roige, Sandra; Cigarroa, Igor; Gagliano, Humberto; Fuentes, Silvia; Armario, Antonio; Capdevila, Lluís; Escorihuela, Rosa M

2015-11-05

Recent evidence has revealed the impact of exercise in alleviating anxiety and mood disorders; however, the exercise protocol that exerts such benefit is far from known. The current study was aimed to assess the effects of long-term moderate exercise on behavioural coping strategies (active vs. passive) and Hypothalamic-Pituitary-Adrenal response in rats. Sprague-Dawley male and female rats were exposed to 32-weeks of treadmill exercise and then tested for two-way active avoidance learning (shuttle-box). Two groups were used as controls: a non-handled sedentary group, receiving no manipulation, and a control group exposed to a stationary treadmill. Female rats displayed shorter escape responses and higher number of avoidance responses, reaching criterion for performance earlier than male rats. In both sexes, exercise shortened escape latencies, increased the total number of avoidances and diminished the number of trials needed to reach criterion for performance. Those effects were greater during acquisition in female rats, but remained over the shuttle-box sessions in treadmill trained male rats. In females, exercise did not change ACTH and corticosterone levels after shuttle-box acquisition. Collectively, treadmill exercise improved active coping strategies in a sex-dependent manner. In a broader context, moderate exercise could serve as a therapeutic intervention for anxiety and mood disorders.

Long-term moderate treadmill exercise promotes stress-coping strategies in male and female rats

PubMed Central

Lalanza, Jaume F.; Sanchez-Roige, Sandra; Cigarroa, Igor; Gagliano, Humberto; Fuentes, Silvia; Armario, Antonio; Capdevila, Lluís; Escorihuela, Rosa M.

2015-01-01

Recent evidence has revealed the impact of exercise in alleviating anxiety and mood disorders; however, the exercise protocol that exerts such benefit is far from known. The current study was aimed to assess the effects of long-term moderate exercise on behavioural coping strategies (active vs. passive) and Hypothalamic-Pituitary-Adrenal response in rats. Sprague-Dawley male and female rats were exposed to 32-weeks of treadmill exercise and then tested for two-way active avoidance learning (shuttle-box). Two groups were used as controls: a non-handled sedentary group, receiving no manipulation, and a control group exposed to a stationary treadmill. Female rats displayed shorter escape responses and higher number of avoidance responses, reaching criterion for performance earlier than male rats. In both sexes, exercise shortened escape latencies, increased the total number of avoidances and diminished the number of trials needed to reach criterion for performance. Those effects were greater during acquisition in female rats, but remained over the shuttle-box sessions in treadmill trained male rats. In females, exercise did not change ACTH and corticosterone levels after shuttle-box acquisition. Collectively, treadmill exercise improved active coping strategies in a sex-dependent manner. In a broader context, moderate exercise could serve as a therapeutic intervention for anxiety and mood disorders. PMID:26538081

Critical role of CA1 muscarinic receptors on memory acquisition deficit induced by total (TSD) and REM sleep deprivation (RSD).

PubMed

Javad-Moosavi, Bibi-Zahra; Vaezi, Gholamhassan; Nasehi, Mohammad; Haeri-Rouhani, Seyed-Ali; Zarrindast, Mohammad-Reza

2017-10-03

Despite different theories regarding sleep physiological function, an overall census indicates that sleep is useful for neural plasticity which eventually strengthens cognition and brain performance. Different studies show that sleep deprivation (SD) leads to impaired learning and hippocampus dependent memory. According to some studies, cholinergic system plays an important role in sleep (particularly REM sleep), learning, memory, and its retrieval. So this study has been designed to investigate the effect of CA1 Cholinergic Muscarinic Receptors on memory acquisition deficit induced by total sleep deprivation (TSD) and REM sleep deprivation (RSD). A modified water box (locomotor activity may be provide a limiting factor in this method of SD) or multiple platforms were used for induction of TSD or RSD, respectively. Inhibitory passive avoidance apparatus has been used to determine the effects of SD and its changes by physostigmine (as cholinesterase inhibitor) or scopolamine (muscarinic receptor antagonist) on memory formation. Because locomotor activity and pain perception induce critical roles in passive avoidance memory formation, we also measured these factors by open field and hot-plate instruments, respectively. The results showed that TSD and RSD for 24 hours impaired memory formation but they did not alter locomotor activity. TSD also induced analgesia effect, but RSD did not alter it. Intra-CA1 injection of physostigmine (0.0001μg/rat) and scopolamine (0.01μg/rat) did not alter memory acquisition in the sham-TSD or sham-RSD, by themselves. Moreover, intra-CA1 injection of sub-threshold dose of physostigmine (0.0001μg/rat) and scopolamine (0.01μg/rat) could restore the memory acquisition deficit induced by RSD, while scopolamine could restore TSD-induced amnesia. Both drugs reversed analgesia induced by TSD. None of previous interventions altered locomotor activity. According to this study, CA1 cholinergic muscarinic receptors play an important role in amnesia induced by both TSD and RSD. However further studies are needed for showing cellular and molecular mechanisms of surprising result of similar pharmacological effects using compounds with opposite profiles. Copyright © 2016. Published by Elsevier Inc.

The hydroalcoholic extract of Salvia elegans induces anxiolytic- and antidepressant-like effects in rats.

PubMed

Mora, S; Millán, R; Lungenstrass, H; Díaz-Véliz, G; Morán, J A; Herrera-Ruiz, M; Tortoriello, J

2006-06-15

Behavioral effects of a hydroalcoholic (60% ethanol) extract from the leaves of Salvia elegans Vahl (Lamiaceae) were studied in male Sprague-Dawley rats. The extract was administered intraperitoneally and its effects on spontaneous motor activity (total motility, locomotion, rearing and grooming behavior) were monitored. Putative anxiolytic and antidepressant properties of Salvia elegans were studied in the elevated plus-maze test (EPM) and in the forced swimming test (FST), respectively. Deleterious effects of Salvia elegans on learning and memory were also studied by using active and passive avoidance paradigms. The results revealed that all doses (3.12, 12.5, 25 and 50 mg/kg) of the extract caused a significant decrease in total motility, locomotion, rearing and grooming behavior. Only the dose of 12.5 mg/kg increased the exploration of the EPM open arms in a similar way to that of diazepam (1 mg/kg). In the FST, all doses of the extract induced a reduction of immobility, in a similar way to that of fluoxetine (10 mg/kg) and imipramine (12.5 mg/kg), along with a significant increase in the time spent in swimming behavior. Acquisition of active avoidance responses was disrupted by pre-treatment with the extract, but retention of a passive avoidance response was not significantly modified. These results suggest that some of the components of the hydroalcoholic extract of Salvia elegans have psychotropic properties, which deserve further investigation.

Learning and memory deficits in mice lacking protease activated receptor-1

PubMed Central

Almonte, Antoine G.; Hamill, Cecily E.; Chhatwal, Jasmeer P.; Wingo, Thomas S.; Barber, Jeremy A.; Lyuboslavsky, Polina N.; Sweatt, J. David; Ressler, Kerry J.; White, David A.; Traynelis, Stephen F.

2007-01-01

The roles of serine proteases and protease activated receptors have been extensively studied in coagulation, wound healing, inflammation, and neurodegeneration. More recently, serine proteases have been suggested to influence synaptic plasticity. In this context, we examined the role of protease activated receptor 1 (PAR1), which is activated following proteolytic cleavage by thrombin and plasmin, in emotionally-motivated learning. We were particularly interested in PAR1 because its activation enhances the function of NMDA receptors, which are required for some forms of synaptic plasticity. We examined several baseline behavioral measures, including locomotor activity, expression of anxiety-like behavior, motor task acquisition, nociceptive responses, and startle responses in C57Bl/6 mice in which the PAR1 receptor has been genetically deleted. In addition, we evaluated learning and memory in these mice using two memory tasks, passive avoidance and cued fear-conditioning. Whereas locomotion, pain response, startle, and measures of baseline anxiety were largely unaffected by PAR1 removal, PAR1−/− animals showed significant deficits in a passive avoidance task and in cued fear conditioning. These data suggest that PAR1 may play an important role in emotionally-motivated learning. PMID:17544303

Cognitive benefits of Angiotensin IV and Angiotensin-(1-7): a systematic review of experimental studies.

PubMed

Ho, Jean K; Nation, Daniel A

2018-05-04

To explore effects of the brain renin-angiotensin system (RAS) on cognition. Systematic review of experimental (non-human) studies assessing cognitive effects of RAS peptides angiotensin-(3-8) [Ang IV] and angiotensin-(1-7) [Ang-(1-7)] and their receptors, the Ang IV receptor (AT4R) and the Mas receptor. Of 450 articles identified, 32 met inclusion criteria. Seven of 11 studies of normal animals found Ang IV had beneficial effects on tests of passive or conditioned avoidance and object recognition. In models of cognitive deficit, eight of nine studies found Ang IV and its analogs (Nle 1 -Ang IV, dihexa, LVV-hemorphin-7) improved performance on spatial working memory and passive avoidance tasks. Two of three studies examining Ang-(1-7) found it benefited memory. Mas receptor removal was associated with reduced fear memory in one study. Studies of cognitive impairment show salutary effects of acute administration of Ang IV and its analogs, as well as AT4R activation. Brain RAS peptides appear most effective administered intracerebroventricularly, close to the time of learning acquisition or retention testing. Ang-(1-7) shows anti-dementia qualities. Copyright © 2018. Published by Elsevier Ltd.

Developmental Perspectives on the Acquisition of the Passive

ERIC Educational Resources Information Center

Crawford, Jean Lenore

2012-01-01

This dissertation investigates the acquisition of the passive. The apparent cross-linguistic delay of the verbal passive compared to other constructions suggests children's knowledge is somehow restricted, leading some to propose the difficulty arises because of syntactic maturation (Wexler 2004, Orfitelli 2012) or because of a heavy reliance…

Effect of radio-frequency electromagnetic radiations (RF-EMR) on passive avoidance behaviour and hippocampal morphology in Wistar rats.

PubMed

Narayanan, Sareesh Naduvil; Kumar, Raju Suresh; Potu, Bhagath Kumar; Nayak, Satheesha; Bhat, P Gopalakrishna; Mailankot, Maneesh

2010-05-01

The interaction of mobile phone radio-frequency electromagnetic radiation (RF-EMR) with the brain is a serious concern of our society. We evaluated the effect of RF-EMR from mobile phones on passive avoidance behaviour and hippocampal morphology in rats. Healthy male albino Wistar rats were exposed to RF-EMR by giving 50 missed calls (within 1 hour) per day for 4 weeks, keeping a GSM (0.9 GHz/1.8 GHz) mobile phone in vibratory mode (no ring tone) in the cage. After the experimental period, passive avoidance behaviour and hippocampal morphology were studied. Passive avoidance behaviour was significantly affected in mobile phone RF-EMR-exposed rats demonstrated as shorter entrance latency to the dark compartment when compared to the control rats. Marked morphological changes were also observed in the CA(3) region of the hippocampus of the mobile phone-exposed rats in comparison to the control rats. Mobile phone RF-EMR exposure significantly altered the passive avoidance behaviour and hippocampal morphology in rats.

Involvement of NMDA glutamate receptors in the acquisition and reinstatement of the conditioned place preference induced by MDMA.

PubMed

García-Pardo, Maria P; Escobar-Valero, Carla; Rodríguez-Arias, Marta; Miñarro, Jose; Aguilar, Maria A

2015-08-01

Some 3,4-methylenedioxymethamphetamine (MDMA) users become dependent as a result of chronic consumption. A greater understanding of the neurobiological basis of the rewarding effects of MDMA could contribute to developing effective pharmacotherapies for MDMA-related problems. The present study evaluated the role of N-methyl-D-aspartate (NMDA) glutamate receptors (NMDARs) in the acquisition and reinstatement of conditioned place preference (CPP) induced by MDMA. Adolescent male mice were conditioned with 1 or 10 mg/kg MDMA and pretreated with 5 or 10 mg/kg of the NMDAR antagonist memantine during acquisition of conditioning (experiment 1), or before a reinstatement test (experiment 2). In addition, the effects of memantine on acquisition of chocolate-induced CPP and the effects of memantine and MDMA on a passive avoidance task were evaluated. Memantine did not exert any motivational effects, but blocked the acquisition of MDMA-induced CPP. Moreover, following acquisition and extinction of MDMA-induced CPP, memantine did not induce reinstatement but blocked reinstatement of the CPP induced by priming with MDMA. Memantine did not block the CPP induced by chocolate, and it partially reversed the impairing effects of MDMA on memory. Our results demonstrate that NMDARs are involved in acquisition of the conditioned rewarding effects of MDMA and in priming-induced reinstatement of CPP following extinction. Moreover, they suggest the validity of memantine for the treatment of MDMA abuse.

Effects of the antidepressant drug moclobemide on learning and memory in rats.

PubMed

Getova, D; Dimitrova, D; Roukounakis, I

2003-12-01

Moclobemide is a well known drug with antidepressant action. The aim of this study was to investigate the effects of moclobemide on learning and memory processes in Sprague Dawley rats. Over a 5-day period, learning sessions with 30 trials per day and memory retention tests were performed. The conditioned responses (avoidances), the unconditioned responses (escapes) and the intertrial crossings were observed. An active avoidance test was carried out using a shuttle box. Two passive avoidance tests were used: step-through (using a light chamber) and step-down (using a platform). In the step-through passive avoidance test, the learning and retention sessions consisted of three trials each and the latency of reaction times (the rat remaining in the light chamber for more than 180 sec) was used as criterion. In the step-down passive avoidance test, learning and retention sessions consisted of two trials and the latency of reaction times (the rat remaining on the platform for 60 sec) was used as criterion. In the active avoidance tests, moclobemide dose-dependently increased the number of avoidances during learning sessions and maintained this number in memory retention tests. Moclobemide did not alter the number of escapes, but did increase motor activity. In the passive avoidance tests, moclobemide also increased the latency of reaction times in learning and short memory retrieval tests. These findings suggest that moclobemide improves learning and memory processes in active and passive avoidance tests and has a cognition-enhancing effect. (c) 2003 Prous Science

[Influence of activation and blockade of NMDA receptors on extinction of passive avoidance response in mice with different levels of anxiety].

PubMed

Tomilenko, R A; Dubrovina, N I

2006-03-01

Influence of agonist (D-cycloserine) and antagonist (dizocilpine) N-methyl-D-aspartate receptors on learning and extinction of passive avoidance response in medium-, high-, and low-anxious mice was studied. In medium-anxious mice, D-cycloserine (30 mg/kg) although not changing learning accelerated development of extinction, whereas dizocilpine (0.15 mg/kg), while impairing passive avoidance learning, detained the extinction. In high-anxious mice with good retrieval of memory trace and absence of extinction, D-cycloserine was ineffective, whereas dizocilpine reduced learning and promoted retention of memory trace retrieval at the generated level on extinction. In low-anxious mice, D-cycloserine impaired learning and accelerated extinction, whereas dizocilpine completely blocked learning and retention of passive avoidance response.

7-Nitroindazole, a neuronal nitric oxide synthase inhibitor, impairs passive-avoidance and elevated plus-maze memory performance in rats.

PubMed

Yildiz Akar, Furuzan; Ulak, Guner; Tanyeri, Pelin; Erden, Faruk; Utkan, Tijen; Gacar, Nejat

2007-10-01

The role of nitric oxide (NO) on cognitive performance in a modified elevated plus-maze (mEPM) and passive-avoidance (PA) task was investigated by using the NO synthase (NOS) inhibitor 7-nitroindazole (7-NI) and an NO precursor l-arginine. The interaction between the activation of N-methyl-d-aspartate (NMDA) receptors and NO synthesis on memory retention was also studied. 7-NI, l-arginine or MK-801, a non-competitive NMDA receptor antagonist were injected intraperitoneally (i.p) to male Wistar rats 30 min before the first training session of the PA test or 30 min before on the first day testing (acquisition session) of mEPM task. Transfer latency, the time rat took to move from the open arm to the enclosed arm, was used as an index of learning and memory in a mEPM test. The retention session was performed 24 h after the acquisition one. In the PA task, the retention test was carried out 24 h after training and reduction of retention latency was used to evaluate the acquisition of learning and memory. Blood glucose level and locomotor activity of the rats was also evaluated. 7-NI (10, 20, 25, 50 mg/kg) and MK-801 (0.15 mg/kg) significantly prolonged the transfer latency on retention session in a mEPM test and shortened step-through latency in PA test. 7-NI-induced impairment in memory and learning was partly reversed by l-arginine (200 mg/kg), a competitive substrate for NOS. However subeffective doses of 7-NI (5 mg/kg) and MK-801 (0.075 mg/kg) given in combination significantly impaired plus-maze and PA performances in rats. Thus NMDA receptor mediated NO pathways may be implicated in the PA and mEPM behaviours in rats. Since 7-NI does not affect blood pressure and did not alter blood glucose level and locomotor activity in conscious rats, 7-NI-induced impairment of memory is not due to either hypertension, changes in blood glucose level or effects on locomotor activity.

An Event-Structural Account of Passive Acquisition in Korean

ERIC Educational Resources Information Center

Lee, Kwee-Ock; Lee, Youngjoo

2008-01-01

Some peculiar properties of children's passives have long been observed in various languages such as an asymmetry between actional passives and nonactional passives. These peculiarities have been accounted for under the hypothesis that children's early passives are adjectival, and as such exhibit properties of adjectival passives in adult grammar.…

I-SCAD® standoff chemical agent detector overview

NASA Astrophysics Data System (ADS)

Popa, Mirela O.; Griffin, Matthew T.

2012-06-01

This paper presents a system-level description of the I-SCAD® Standoff Chemical Agent Detector, a passive Fourier Transform InfraRed (FTIR) based remote sensing system, for detecting chemical vapor threats. The passive infrared detection system automatically searches the 7 to 14 micron region of the surrounding atmosphere for agent vapor clouds. It is capable of operating while on the move to accomplish reconnaissance, surveillance, and contamination avoidance missions. Additionally, the system is designed to meet the needs for application on air and sea as well as ground mobile and fixed site platforms. The lightweight, passive, and fully automatic detection system scans the surrounding atmosphere for chemical warfare agent vapors. It provides on-the-move, 360-deg coverage from a variety of tactical and reconnaissance platforms at distances up to 5 km. The core of the system is a rugged Michelson interferometer with a flexure spring bearing mechanism and bi-directional data acquisition capability. The modular system design facilitates interfacing to many platforms. A Reduced Field of View (RFOV) variant includes novel modifications to the scanner subcomponent assembly optical design that gives extended performance in detection range and detection probability without sacrificing existing radiometric sensitivity performance. This paper will deliver an overview of system.

Potentiation of the early visual response to learned danger signals in adults and adolescents

PubMed Central

Howsley, Philippa; Jordan, Jeff; Johnston, Pat

2015-01-01

The reinforcing effects of aversive outcomes on avoidance behaviour are well established. However, their influence on perceptual processes is less well explored, especially during the transition from adolescence to adulthood. Using electroencephalography, we examined whether learning to actively or passively avoid harm can modulate early visual responses in adolescents and adults. The task included two avoidance conditions, active and passive, where two different warning stimuli predicted the imminent, but avoidable, presentation of an aversive tone. To avoid the aversive outcome, participants had to learn to emit an action (active avoidance) for one of the warning stimuli and omit an action for the other (passive avoidance). Both adults and adolescents performed the task with a high degree of accuracy. For both adolescents and adults, increased N170 event-related potential amplitudes were found for both the active and the passive warning stimuli compared with control conditions. Moreover, the potentiation of the N170 to the warning stimuli was stable and long lasting. Developmental differences were also observed; adolescents showed greater potentiation of the N170 component to danger signals. These findings demonstrate, for the first time, that learned danger signals in an instrumental avoidance task can influence early visual sensory processes in both adults and adolescents. PMID:24652856

Human hippocampus arbitrates approach-avoidance conflict.

PubMed

Bach, Dominik R; Guitart-Masip, Marc; Packard, Pau A; Miró, Júlia; Falip, Mercè; Fuentemilla, Lluís; Dolan, Raymond J

2014-03-03

Animal models of human anxiety often invoke a conflict between approach and avoidance. In these, a key behavioral assay comprises passive avoidance of potential threat and inhibition, both thought to be controlled by ventral hippocampus. Efforts to translate these approaches to clinical contexts are hampered by the fact that it is not known whether humans manifest analogous approach-avoidance dispositions and, if so, whether they share a homologous neurobiological substrate. Here, we developed a paradigm to investigate the role of human hippocampus in arbitrating an approach-avoidance conflict under varying levels of potential threat. Across four experiments, subjects showed analogous behavior by adapting both passive avoidance behavior and behavioral inhibition to threat level. Using functional magnetic resonance imaging (fMRI), we observe that threat level engages the anterior hippocampus, the human homolog of rodent ventral hippocampus. Testing patients with selective hippocampal lesions, we demonstrate a causal role for the hippocampus with patients showing reduced passive avoidance behavior and inhibition across all threat levels. Our data provide the first human assay for approach-avoidance conflict akin to that of animal anxiety models. The findings bridge rodent and human research on passive avoidance and behavioral inhibition and furnish a framework for addressing the neuronal underpinnings of human anxiety disorders, where our data indicate a major role for the hippocampus. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Prolongation of latencies for passive avoidance responses in rats treated with aniracetam or piracetam.

PubMed

Yamada, K; Inoue, T; Tanaka, M; Furukawa, T

1985-04-01

Effects of aniracetam (1-anysoyl-2-pyrrolodone) and piracetam (1-acetamido-2-pyrrolidone) on passive avoidance behavior were studied in 2 and 18 months old rats using a step-down passive avoidance task. Repeated administration of aniracetam (30 and 50 mg/kg, IP X 5 days) or piracetam (100 mg/kg, IP X 5 days) significantly prolonged step-down latencies for a passive avoidance task in 2 months old rats. Administration of aniracetam (50 mg/kg, IP) or piracetam (100 mg/kg, IP), however, did not affect locomotor activity. This prolongation of latencies was also seen with oral administration of aniracetam (50 mg/kg X 5 days). Similar prolongation of latencies also occurred in 18 months old rat treated with aniracetam (50 mg/kg, IP X 5 days). The results imply that aniracetam may improve learning and/or memory in 2 and 18 months old rats.

Commentary on "Capturing the Evasive Passive"

ERIC Educational Resources Information Center

Lillo-Martin, Diane; Snyder, William

2009-01-01

Passives has been the focus of much research in language acquisition since the 1970s. It has been clear from this research that young children seldom produce passives spontaneously, particularly "long" or "full" passives with a by-phrase; and they usually perform poorly on experimental tests of the comprehension of passives, especially passives of…

31 CFR 800.223 - Solely for the purpose of passive investment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (Continued) OFFICE OF INVESTMENT SECURITY, DEPARTMENT OF THE TREASURY REGULATIONS PERTAINING TO MERGERS, ACQUISITIONS, AND TAKEOVERS BY FOREIGN PERSONS Definitions § 800.223 Solely for the purpose of passive... Board of Directors. The acquisition by Corporation A of a voting interest in Corporation B is not solely...

The novel substituted acylproline-containing dipeptide, GVS-111, promotes the restoration of learning and memory impaired by bilateral frontal lobectomy in rats.

PubMed

Ostrovskaya, R U; Romanova, G A; Trofimov, S S; Gudasheva, T A; Voronina, T A; Halikas, J A; Seredenin, S B

1997-06-01

The present study investigated the potential benefit of the ethyl ester of N-phenylacetylprolylglycine (GVS-111) on the model of bilateral frontal lobectomy (BFL) in rats. The animals in Experiment 1 were trained in an active avoidance task and subsequently underwent BFL. The animals in Experiment 2 were first assessed in an open field and in a passive avoidance test before the BFL was performed. BFL dramatically decreased performance in the active avoidance test, disturbed habituation of horizontal activity in the open field and diminished the latency to enter the dark compartment in the passive avoidance test. GVS-111, administered in a dose of 0.5 mg/kg/day i.p. for 9 days following the operation, was found to improve performance in both active avoidance and passive avoidance and restored habituation of horizontal activity in the lobectomized animals.

Automatic honesty forgoing reward acquisition and punishment avoidance: a functional MRI investigation

PubMed Central

Yoneda, Mei; Ueda, Ryuhei; Ashida, Hiroshi

2017-01-01

Recent neuroimaging investigations into human honesty suggest that honest moral decisions in individuals who consistently behave honestly occur automatically, without the need for active self-control. However, it remains unclear whether this observation can be applied to two different types of honesty: honesty forgoing dishonest reward acquisition and honesty forgoing dishonest punishment avoidance. To address this issue, a functional MRI study, using an incentivized prediction task in which participants were confronted with real and repeated opportunities for dishonest gain leading to reward acquisition and punishment avoidance, was conducted. Behavioral data revealed that the frequency of dishonesty was equivalent between the opportunities for dishonest reward acquisition and for punishment avoidance. Reaction time data demonstrated that two types of honest decisions in the opportunity for dishonest reward acquisition and punishment avoidance required no additional cognitive control. Neuroimaging data revealed that honest decisions in the opportunity for dishonest reward acquisition and those for punishment avoidance required no additional control-related activity compared with a control condition in which no opportunity for dishonest behavior was given. These results suggest that honesty flows automatically, irrespective of the concomitant motivation for dishonesty leading to reward acquisition and punishment avoidance. PMID:28746066

Automatic honesty forgoing reward acquisition and punishment avoidance: a functional MRI investigation.

PubMed

Yoneda, Mei; Ueda, Ryuhei; Ashida, Hiroshi; Abe, Nobuhito

2017-09-27

Recent neuroimaging investigations into human honesty suggest that honest moral decisions in individuals who consistently behave honestly occur automatically, without the need for active self-control. However, it remains unclear whether this observation can be applied to two different types of honesty: honesty forgoing dishonest reward acquisition and honesty forgoing dishonest punishment avoidance. To address this issue, a functional MRI study, using an incentivized prediction task in which participants were confronted with real and repeated opportunities for dishonest gain leading to reward acquisition and punishment avoidance, was conducted. Behavioral data revealed that the frequency of dishonesty was equivalent between the opportunities for dishonest reward acquisition and for punishment avoidance. Reaction time data demonstrated that two types of honest decisions in the opportunity for dishonest reward acquisition and punishment avoidance required no additional cognitive control. Neuroimaging data revealed that honest decisions in the opportunity for dishonest reward acquisition and those for punishment avoidance required no additional control-related activity compared with a control condition in which no opportunity for dishonest behavior was given. These results suggest that honesty flows automatically, irrespective of the concomitant motivation for dishonesty leading to reward acquisition and punishment avoidance.

Passive avoidance is linked to impaired fear extinction in humans

PubMed Central

Cornwell, Brian R.; Overstreet, Cassie; Krimsky, Marissa; Grillon, Christian

2013-01-01

Conventional wisdom dictates we must face our fears to conquer them. This idea is embodied in exposure-based treatments for anxiety disorders, where the intent of exposure is to reverse a history of avoidant behavior that is thought to fuel a patient’s irrational fears. We tested in humans the relationship between fear and avoidance by combining Pavlovian differential fear conditioning with a novel task for quantifying spontaneous passive avoidant behavior. During self-guided navigation in virtual reality following de novo fear conditioning, we observed participants keeping their distance from the feared object. At the individual level, passive avoidant behavior was highly associated with maladaptive fear expression (fear-potentiated startle) during late extinction training, indicating that extinction learning was impaired following a brief episode of avoidance. Avoidant behavior, however, was not related to initial acquired fear, raising doubt about a straightforward link between physiological fear and behavioral avoidance. We conclude that a deeper understanding of what motivates avoidance may offer a target for early intervention, before fears transition from the rational to the irrational. PMID:23427168

78 FR 35262 - Detection and Avoidance of Counterfeit Electronic Parts

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-12

... DEPARTMENT OF DEFENSE Defense Acquisition Regulations System [DFARS Case 2012-D055] Detection and Avoidance of Counterfeit Electronic Parts AGENCY: Defense Acquisition Regulations System, Department of... detection and avoidance coverage proposed to be included in the Defense Federal Acquisition Regulation...

Acquisition and carriage of meningococci in marine commando recruits.

PubMed Central

Riordan, T.; Cartwright, K.; Andrews, N.; Stuart, J.; Burris, A.; Fox, A.; Borrow, R.; Douglas-Riley, T.; Gabb, J.; Miller, A.

1998-01-01

Meningococcal acquisition is a prerequisite for invasive disease. Three hundred and eleven male marine commando recruits were studied throughout 29 weeks of basic training to identify factors influencing meningococcal carriage and acquisition including troop number, season, smoking, respiratory infection, antibiotic usage and nasopharyngeal bacterial interference flora. A high carriage rate on entry to training (118/311, 37.9%) and subsequent sustained high rates of meningococcal acquisition were found. Of the potential factors examined, only active and passive smoking were found to be associated significantly with meningococcal carriage on entry. The association between active smoking and meningococcal carriage was dose-dependent, with odds ratios (OR) of 2.2 (95% CIs 1.0-4.8) and 7.2 (95% CIs 2.3-22.9) for light and heavy smokers respectively. Passive smoking predisposed independently to carriage (OR 1.8, 95% CIs 1.1-3.0). Active and passive smoking combined to give an attributable risk for meningococcal carriage of 33%. In contrast, despite a high and sustained rate of meningococcal acquisition in the study population, none of the risk factors investigated, including active smoking, was associated significantly with meningococcal acquisition. No cases of meningococcal disease occurred during the 16-month study period. Therefore smoking may increase the duration of meningococcal carriage rather than the rate of acquisition, consistent with the increased risk of meningococcal disease from passive as opposed to active smoking. Public health measures that reduce the prevalence of smoking should reduce the risk of meningococcal disease. PMID:10030697

TRIMETHYLTIN IMPAIRS RETENTION OF A PASSIVE AVOIDANCE TASK

EPA Science Inventory

Trimethyltin is a neurotoxic organometal which produces neuronal damage in several limbic regions including the hippocampus, amygdala and the pyriform cortex. One administration of trimethyltin (5,6 or 7 mg/kg) twenty one days prior to passive avoidance conditioning produced an i...

Tobacco Use and Environmental Smoke Exposure among Taiwanese Pregnant Smokers and Recent Quitters: Risk Perception, Attitude, and Avoidance Behavior

PubMed Central

Lai, Ming-Cheng; Chou, Feng-Sha; Yang, Yann-Jy; Wang, Chih-Chien; Lee, Ming-Chang

2013-01-01

In this study, we conducted an empirical survey of the avoidance behaviors and risk perceptions of active and passive smoking pregnant smokers and recent quitters. We employed an online questionnaire survey by recruiting 166 voluntary participants from an online parenting community in Taiwan. The results of the empirical survey revealed that three-fourths of smokers quit smoking during pregnancy and one-fourth continued smoking. All pregnant women who continued smoking had partners or lived with relatives who smoked. Current smokers and quitters differed significantly in their risk perceptions and attitudes toward smoking during pregnancy. Most pregnant smokers and quitters adopted passive smoking avoidance behaviors at home and in public. Nevertheless, one-fifth of pregnant women chose not to avoid passive smoking. We concluded that most women stop smoking during pregnancy; however, most women continue to be exposed to passive-smoking environments. Perceived fetal health risks and attitudes toward smoking during pregnancy are critical predictors of the anti-smoking behaviors of pregnant women. PMID:24005830

Aniracetam reverses memory impairment in rats.

PubMed

Martin, J R; Moreau, J L; Jenck, F

1995-02-01

The pyrrolidinone derivative aniracetam given orally immediately after acquisition of an inhibitory avoidance response reproducibly ameliorated scopolamine-induced amnesia in female rats in an extensive series of test sessions conducted over a 1-year period. In a dose-response experiment it was demonstrated that 50 mg kg-1 was the lowest oral dose of aniracetam to significantly ameliorate scopolamine-induced amnesia. Combined results from these numerous test sessions demonstrated that 50 mg kg-1 aniracetam administered to scopolamine-treated rats resulted in 53% of the animals exhibiting correct passive avoidance responding in the retention evaluation versus 9% of the scopolamine-treated rats given vehicle (in comparison, 64% of the rats injected with vehicle rather than scopolamine in this experimental situation exhibited correct responding in the retention test). There was minimal variation in this pattern of results over the successive 1-month blocks constituting the complete experimental period. Thus, the nootropic compound aniracetam replicably exhibited memory enhancing effects in this animal model of reduced cholinergic function.

Nootropic activity of extracts from wild and cultivated Alfredia cernua.

PubMed

Mustafin, R N; Shilova, I V; Suslov, N I; Kuvacheva, N V; Amelchenko, V P

2011-01-01

Antihypoxic and nootropic activities of extracts from aerial parts of wild and cultivated Alfredia cernua (L.) Cass. were studied on the models of pressure chamber hypoxia, open field test, and passive avoidance conditioning. The extracts of Alfredia cernua promoted retention of the orientation reflex and passive avoidance conditioned response and normalized orientation and exploratory activities disordered as a result of hypoxic injury. The efficiency of the extracts was superior to that of piracetam by the effect on retention of passive avoidance response throughout the greater part of the experiment. Nootropic activity of cultivated Alfredia cernua was not inferior to that of the wild plant.

Is Young Children's Passive Syntax Semantically Constrained? Evidence from Syntactic Priming

ERIC Educational Resources Information Center

Messenger, Katherine; Branigan, Holly P.; McLean, Janet F.; Sorace, Antonella

2012-01-01

Previous research suggests that English-speaking children comprehend agent-patient verb passives earlier than experiencer-theme verb passives (Maratsos, Fox, Becker, & Chalkley, 1985). We report three experiments examining whether such effects reflect delayed acquisition of the passive syntax or instead are an artifact of the experimental task,…

48 CFR 552.211-92 - Radio Frequency Identification (RFID) using passive tags.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Identification (RFID) using passive tags. 552.211-92 Section 552.211-92 Federal Acquisition Regulations System... Provisions and Clauses 552.211-92 Radio Frequency Identification (RFID) using passive tags. As prescribed in 511.204(b)(11), insert the following clause: Radio Frequency Identification (RFID) Using Passive Tags...

48 CFR 552.211-92 - Radio Frequency Identification (RFID) using passive tags.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Identification (RFID) using passive tags. 552.211-92 Section 552.211-92 Federal Acquisition Regulations System... Provisions and Clauses 552.211-92 Radio Frequency Identification (RFID) using passive tags. As prescribed in 511.204(b)(11), insert the following clause: Radio Frequency Identification (RFID) Using Passive Tags...

31 CFR 800.223 - Solely for the purpose of passive investment.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Solely for the purpose of passive..., ACQUISITIONS, AND TAKEOVERS BY FOREIGN PERSONS Definitions § 800.223 Solely for the purpose of passive investment. Ownership interests are held or acquired solely for the purpose of passive investment if the...

Involvement of nitric oxide in granisetron improving effect on scopolamine-induced memory impairment in mice.

PubMed

Javadi-Paydar, Mehrak; Zakeri, Marjan; Norouzi, Abbas; Rastegar, Hossein; Mirazi, Naser; Dehpour, Ahmad Reza

2012-01-06

Granisetron, a serotonin 5-HT(3) receptor antagonist, widely used as an antiemetic drug following chemotherapy, has been found to improve learning and memory. In this study, effects of granisetron on spatial recognition memory and fear memory and the involvement of nitric oxide (NO) have been determined in a Y-maze and passive avoidance test. Granisetron (3, 10mg/kg, intraperitoneally) was administered to scopolamine-induced memory-impaired mice prior to acquisition, consolidation and retrieval phases, either in the presence or in the absence of a non-specific NO synthase inhibitor, l-NAME (3, 10mg/kg, intraperitoneally); a specific inducible NO synthase (iNOS) inhibitor, aminoguanidine (100mg/kg); and a NO precursor, l-arginine (750 mg/kg). It is demonstrated that granisetron improved memory acquisition in a dose-dependent manner, but it was ineffective on consolidation and retrieval phases of memory. The beneficial effect of granisetron (10mg/kg) on memory acquisition was significantly reversed by l-NAME (10mg/kg) and aminoguanidine (100mg/kg); however, l-arginine (750 mg/kg) did not potentiate the effect of sub-effective dose of granisetron (3mg/kg) in memory acquisition phase. It is concluded that nitric oxide is probably involved in improvement of memory acquisition by granisetron in both spatial recognition memory and fear memory. This article is part of a Special Issue entitled The Cognitive Neuroscience. Copyright © 2011 Elsevier B.V. All rights reserved.

PWZ-029, A COMPOUND WITH MODERATE INVERSE AGONIST FUNCTIONAL SELECTIVITY AT GABAA RECEPTORS CONTAINING α5 SUBUNITS, IMPROVES PASSIVE, BUT NOT ACTIVE, AVOIDANCE LEARNING IN RATS

PubMed Central

Savić, Miroslav M.; Clayton, Terry; Furtmüller, Roman; Gavrilović, Ivana; Samardžić, Janko; Savić, Snežana; Huck, Sigismund; Sieghart, Werner; Cook, James M.

2008-01-01

Benzodiazepine (BZ) site ligands affect vigilance, anxiety, memory processes, muscle tone and epileptogenic propensity through modulation of neurotransmission at GABAA receptors containing α1, α2, α3 or α5 subunits, and may have numerous experimental and clinical applications. The ability of nonselective BZ site inverse agonists to enhance cognition, documented in animal models and human studies, is clinically not feasible due to potentially unacceptable psychomotor effects. Most investigations to date have proposed the α1 and/or α5 subunit-containing GABAA receptors as comprising the memory-modulating population of these receptors. The novel ligand PWZ-029, which we synthesised and characterized electrophysiologically, possesses in vitro binding selectivity and moderate inverse agonist functional selectivity at α5-containing GABAA receptors. This ligand has also been examined in rats in the passive and active avoidance, spontaneous locomotor activity, elevated plus maze and grip strength tests, primarily predictive of the effects on the memory acquisition, basal locomotor activity, anxiety level and muscle tone, respectively. The improvement of task learning was detected at the dose of 5 mg/kg in the passive, but not active avoidance test. The inverse agonist PWZ-029 had no effect on anxiety or muscle tone, whereas at higher doses (10 and 20 mg/kg) it decreased locomotor activity. This effect was antagonized by flumazenil and also by the lower (but not the higher) dose of an agonist (SH-053-R-CH3-2’F) selective for GABAA receptors containing the α5 subunit. The hypolocomotor effect of PWZ-029 was not antagonized by the antagonist β-CCt exhibiting a preferential affinity for α1-subunit containing receptors. These data suggest that moderate negative modulation at GABAA receptors containing the α5 subunit is a sufficient condition for eliciting enhanced encoding/consolidation of declarative memory, while the influence of higher doses of modulators at these receptors on motor activity shows an intricate pattern whose relevance and mechanism await to be defined. PMID:18394590

The Comparative Effects of Processing Instruction and Dictogloss on the Acquisition of the English Passive by Speakers of Turkish

ERIC Educational Resources Information Center

Uludag, Onur; Vanpatten, Bill

2012-01-01

The current study presents the results of an experiment investigating the effects of processing instruction (PI) and dictogloss (DG) on the acquisition of the English passive voice. Sixty speakers of Turkish studying English at university level were assigned to three groups: one receiving PI, the other receiving DG and the third serving as a…

Involvement of amygdalar extracellular zinc in rat behavior for passive avoidance.

PubMed

Takeda, Atsushi; Minami, Akira; Yamaide, Rie; Oku, Naoto

2004-03-25

On the basis of the evidence that zinc is released from glutamatergic neuron terminals in the amygdala, the effect of chelation of amygdalar extracellular zinc on glutamate release from the neuron terminals was studied by using in vivo microdialysis. When the amygdala was perfused with 100 microM CaEDTA to chelate extracellular zinc, glutamate concentration in the perfusate was decreased significantly, whereas that tended to be increased by perfusion with 100 microM ZnEDTA as a control. The effect of CaEDTA on extracellular glutamate levels was different between the amygdala and hippocampus, implying that modulation of glutamate signaling by zinc is different between them. To evaluate chelation of zinc in rat behavior, perfusion of the amygdala with CaEDTA was started 40 min before behavioral test for passive avoidance. The behavior for passive avoidance was impaired during perfusion with CaEDTA. On the other hand, the behavior during perfusion with ZnEDTA was more rapidly developed than that with vehicle only. These results suggest that amygdalar extracellular zinc is involved in the behavior for passive avoidance.

Protective Effects of Enriched Environment Against Transient Cerebral Ischemia-Induced Impairment of Passive Avoidance Memory and Long-Term Potentiation in Rats

PubMed Central

Ahmadalipour, Ali; Sadeghzadeh, Jafar; Samaei, Seyed Afshin; Rashidy-Pour, Ali

2017-01-01

Introduction: Enriched Environment (EE), a complex novel environment, has been demonstrated to improve synaptic plasticity in both injured and intact animals. The present study investigated the capacity of an early environmental intervention to normalize the impairment of passive avoidance memory and Long-Term Potentiation (LTP) induced by transient bilateral common carotid artery occlusion (2-vessel occlusion, 2VO) in rats. Methods: After weaning, young Wistar rats (22 days old) were housed in EE or Standard Environment (SE) for 40 days. Transient (30-min) incomplete forebrain ischemia was induced 4 days before the passive avoidance memory test and LTP induction. Results: The transient forebrain ischemia led to impairment of passive avoidance memory and LTP induction in the Perforant Path-Dentate Gyrus (PP-DG) synapses. Interestingly, housing and growing in EE prior to 2VO was found to significantly reverse 2VO-induced cognitive and LTP impairments. Conclusion: Our results suggest that early housing and growing in EE exhibits therapeutic potential to normalize cognitive and LTP abnormalities induced by 2VO ischemic model in rats.

Neuropathological changes in brain cortex and hippocampus in a rat model of Alzheimer's disease.

PubMed

Nobakht, Maliheh; Hoseini, Seyed Mohammad; Mortazavi, Pejman; Sohrabi, Iraj; Esmailzade, Banafshe; Rahbar Rooshandel, Nahid; Omidzahir, Shila

2011-01-01

Alzheimer's disease (AD) is a neurodegenerative disorder with progressive loss of cognitive abilities and memory loss. The aim of this study was to compare neuropathological changes in hippocampus and brain cortex in a rat model of AD. Adult male Albino Wistar rats (weighing 250-300 g) were used for behavioral and histopathological studies. The rats were randomly assigned to three groups: control, sham and Beta amyloid (ABeta) injection. For behavioral analysis, Y-maze and shuttle box were used, respectively at 14 and 16 days post-lesion. For histological studies, Nissl, modified Bielschowsky and modified Congo red staining were performed. The lesion was induced by injection of 4 muL of ABeta (1-40) into the hippocampal fissure. In the present study, ABeta (1-40) injection into hippocampus could decrease the behavioral indexes and the number of CA1 neurons in hippocampus. ABeta injection CA1 caused ABeta deposition in the hippocampus and less than in cortex. We observed the loss of neurons in the hippocampus and cerebral cortex and certain subcortical regions. Y-maze test and single-trial passive avoidance test showed reduced memory retention in AD group. We found a significant decreased acquisition of passive avoidance and alternation behavior responses in AD group compared to control and sham group (P<0.0001). Compacted amyloid cores were present in the cerebral cortex, hippocampus and white matter, whereas, scattered amyloid cores were seen in cortex and hippocampus of AD group. Also, reduced neuronal density was indicated in AD group.

Carryover effects associated with the single-trial passive avoidance learning task in the young chick.

PubMed

Crowe, Simon F; Hale, Matthew W

2002-09-01

The single-trial passive avoidance task is a useful procedure for examining learning and memory in the young chick. However, it has recently been suggested that discrepant results reported by different laboratories are due to differences in training procedure. The present study investigated a number of parameters surrounding the passive avoidance task, using day-old White Leghorn, Black Australorp cockerels. The results suggested that presentation of a water-dipped bead immediately after the aversive bead significantly altered retention levels. In addition, when the water-dipped bead was presented after the aversive bead, chicks failed to discriminate between beads for a period of 10 min following exposure to the aversant experience. A novel variant of the passive avoidance procedure, involving pretraining with a water-dipped red bead, training with an aversant-coated red bead, and testing with a dry red bead, was evaluated. A measure of avoidance was calculated using all three trials. It is suggested that the use of a single bead, measured both before and after the training experience and using both aversant- and water-trained controls, results in the most concise characterization of memory-related phenomena in the chick which is not contaminated by a carryover effect from the aversive training experience to the nonaversive bead.

NASA and ESA Collaboration on Alternative to Nitric Acid Passivation: Parameter Optimization of Citric Acid Passivation for Stainless Steel Alloys

NASA Technical Reports Server (NTRS)

Kessel, Kurt R.

2016-01-01

National Aeronautics and Space Administration (NASA) Headquarters chartered the Technology Evaluation for Environmental Risk Mitigation Principal Center (TEERM) to coordinate agency activities affecting pollution prevention issues identified during system and component acquisition and sustainment processes. The primary objectives of NASA TEERM are to: Reduce or eliminate the use of hazardous materials or hazardous processes at manufacturing, remanufacturing, and sustainment locations. Avoid duplication of effort in actions required to reduce or eliminate hazardous materials through joint center cooperation and technology sharing. Corrosion is an extensive problem that affects the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA). The damaging effects of corrosion result in steep costs, asset downtime affecting mission readiness, and safety risks to personnel. Consequently, it is vital to reduce corrosion costs and risks in a sustainable manner. NASA and ESA have numerous structures and equipment that are fabricated from stainless steel. The standard practice for protection of stainless steel is a process called passivation. Passivation is defined by The American Heritage Dictionary of the English Language as to treat or coat (a metal) in order to reduce the chemical reactivity of its surface. Passivation works by forming a shielding outer (metal oxide) layer that reduces the impact of destructive environmental factors such as air or water. Consequently, this process necessitates a final product that is very clean and free of iron and other contaminants. Typical passivation procedures call for the use of nitric acid; however, there are a number of environmental, worker safety, and operational issues associated with its use. Citric acid is an alternative to nitric acid for the passivation of stainless steels. Citric acid offers a variety of benefits including increased safety for personnel, reduced environmental impact, and reduced operational cost. The primary objective of this effort is to qualify citric acid as an environmentally-preferable alternative to nitric acid for the passivation of stainless steel alloys. While citric acid use has become more prominent in industry, there is little evidence that citric acid is a technically sound passivation agent, especially for the unique and critical applications encountered by NASA and ESA.

Pre-training Catechin gavage prevents memory impairment induced by intracerebroventricular streptozotocin in rats.

PubMed

Zamani, Marzieh; Rohampour, Kambiz; Zeraati, Maryam; Hosseinmardi, Narges; Kazemian, Mostafa M

2015-07-01

To evaluate the effects of Catechin (CAT) on memory acquisition and retrieval in the animal model of sporadic alzheimer`s disease (sAD) induced by intracerebroventricular (icv) injection of streptozotocin (STZ) in passive avoidance memory test. Thirty adult rats were divided into 5 experimental groups (n=6). Animals were treated by icv saline/STZ (3 mg/kg) injection at day one and 3 after cannulation. The STZ+CAT group received 40 mg/kg CAT by daily gavages for 10 days, after icv STZ treatment and before training. The step-through latency (STL) and time spent in the dark compartment (TDC) were evaluated to examine the memory acquisition and retrieval. All tests were performed in Qom University of Medical Sciences, Qom, Iran, from April to December 2013. The STZ treatment significantly decreased STL and increased the number of entries to the dark compartment on the training day. It also increased TDC, on day one and 7 after training. Pre-training gavage of CAT reversed the STL significantly (p=0.027). The CAT treatment also decreased the TDC in both early and late retrieval, in respect to STZ group. This data suggests that CAT as an antioxidant could improve both memory acquisition and retrieval in the animal model of sAD.

Older Age of Onset in Child L2 Acquisition Can Be Facilitative: Evidence from the Acquisition of English Passives by Spanish Natives

ERIC Educational Resources Information Center

Rothman, Jason; Long, Drew; Iverson, Michael; Judy, Tiffany; Lingwall, Anne; Chakravarty, Tushar

2016-01-01

We report a longitudinal comprehension study of (long) passive constructions in two native-Spanish child groups differing by age of initial exposure to L2 English (young group: 3;0-4;0; older group: 6;0-7;0), where amount of input, L2 exposure environment, and socioeconomic status are controlled. Data from a forced-choice task show that both…

Professor Age and Research Assistant Ratings of Passive-Avoidant and Proactive Leadership: The Role of Age-Related Work Concerns and Age Stereotypes

ERIC Educational Resources Information Center

Zacher, Hannes; Bal, P. Matthijs

2012-01-01

Recent research has shown that, in general, older professors are rated to have more passive-avoidant leadership styles than younger professors by their research assistants. The current study investigated professors' age-related work concerns and research assistants' favorable age stereotypes as possible explanations for this finding. Data came…

Intrahippocampal Insulin Improves Memory in a Passive-Avoidance Task in Male Wistar Rats

ERIC Educational Resources Information Center

Babri, Shirin; Badie, Hamid Gholamipour; Khamenei, Saeed; Seyedlar, Mehdi Ordikhani

2007-01-01

The main impacts of insulin favor the peripheral organs. Although it functions as a neuropeptide, insulin possesses also some central effects. The aim of this study was to determine the effect of intrahippocampal infusion of insulin on passive avoidance learning in healthy male rats. Thirty male wistar rats were divided into three groups (n = 10…

A Large-Scale Cross-Linguistic Investigation of the Acquisition of Passive

ERIC Educational Resources Information Center

Armon-Lotem, Sharon; Haman, Ewa; de López, Kristine Jensen; Smoczynska, Magdalena; Yatsushiro, Kazuko; Szczerbinski, Marcin; van Hout, Angeliek; Dabašinskiene, Ineta; Gavarró, Anna; Hobbs, Erin; Kamandulyte-Merfeldiene, Laura; Katsos, Napoleon; Kunnari, Sari; Nitsiou, Chrisa; Olsen, Lone Sundahl; Parramon, Xavier; Sauerland, Uli; Torn-Leesik, Reeli; van der Lely, Heather

2016-01-01

This cross-linguistic study evaluates children's understanding of passives in 11 typologically different languages: Catalan, Cypriot Greek, Danish, Dutch, English, Estonian, Finnish, German, Hebrew, Lithuanian, and Polish. The study intends to determine whether the reported gaps between the comprehension of active and passive and between short and…

Acquisition/expulsion system for earth orbital propulsion system study. Volume 5: Earth storable design

NASA Technical Reports Server (NTRS)

1973-01-01

A comprehensive analysis and parametric design effort was conducted under the earth-storable phase of the program. Passive Acquisition/expulsion system concepts were evaluated for a reusable Orbital Maneuvering System (OMS) application. The passive surface tension technique for providing gas free liquid on demand was superior to other propellant acquisition methods. Systems using fine mesh screens can provide the requisite stability and satisfy OMS mission requirements. Both fine mesh screen liner and trap systems were given detailed consideration in the parametric design, and trap systems were selected for this particular application. These systems are compatible with the 100- to 500-manned mission reuse requirements.

Acquisition and extinction of human avoidance behavior: attenuating effect of safety signals and associations with anxiety vulnerabilities.

PubMed

Sheynin, Jony; Beck, Kevin D; Servatius, Richard J; Myers, Catherine E

2014-01-01

While avoidance behavior is often an adaptive strategy, exaggerated avoidance can be detrimental and result in the development of psychopathologies, such as anxiety disorders. A large animal literature shows that the acquisition and extinction of avoidance behavior in rodents depends on individual differences (e.g., sex, strain) and might be modulated by the presence of environmental cues. However, there is a dearth of such reports in human literature, mainly due to the lack of adequate experimental paradigms. In the current study, we employed a computer-based task, where participants control a spaceship and attempt to gain points by shooting an enemy spaceship that appears on the screen. Warning signals predict on-screen aversive events; the participants can learn a protective response to escape or avoid these events. This task has been recently used to reveal facilitated acquisition of avoidance behavior in individuals with anxiety vulnerability due to female sex or inhibited personality. Here, we extended the task to include an extinction phase, and tested the effect of signals that appeared during "safe" periods. Healthy young adults (n = 122) were randomly assigned to a testing condition with or without such signals. Results showed that the addition of safety signals during the acquisition phase impaired acquisition (in females) and facilitated extinction of the avoidance behavior. We also replicated our recent finding of an association between female sex and longer avoidance duration and further showed that females continued to demonstrate more avoidance behavior even on extinction trials when the aversive events no longer occurred. This study is the first to show sex differences on the acquisition and extinction of human avoidance behavior and to demonstrate the role of safety signals in such behavior, highlighting the potential relevance of safety signals for cognitive therapies that focus on extinction learning to treat anxiety symptoms.

Acquisition and Extinction of Human Avoidance Behavior: Attenuating Effect of Safety Signals and Associations with Anxiety Vulnerabilities

PubMed Central

Sheynin, Jony; Beck, Kevin D.; Servatius, Richard J.; Myers, Catherine E.

2014-01-01

While avoidance behavior is often an adaptive strategy, exaggerated avoidance can be detrimental and result in the development of psychopathologies, such as anxiety disorders. A large animal literature shows that the acquisition and extinction of avoidance behavior in rodents depends on individual differences (e.g., sex, strain) and might be modulated by the presence of environmental cues. However, there is a dearth of such reports in human literature, mainly due to the lack of adequate experimental paradigms. In the current study, we employed a computer-based task, where participants control a spaceship and attempt to gain points by shooting an enemy spaceship that appears on the screen. Warning signals predict on-screen aversive events; the participants can learn a protective response to escape or avoid these events. This task has been recently used to reveal facilitated acquisition of avoidance behavior in individuals with anxiety vulnerability due to female sex or inhibited personality. Here, we extended the task to include an extinction phase, and tested the effect of signals that appeared during “safe” periods. Healthy young adults (n = 122) were randomly assigned to a testing condition with or without such signals. Results showed that the addition of safety signals during the acquisition phase impaired acquisition (in females) and facilitated extinction of the avoidance behavior. We also replicated our recent finding of an association between female sex and longer avoidance duration and further showed that females continued to demonstrate more avoidance behavior even on extinction trials when the aversive events no longer occurred. This study is the first to show sex differences on the acquisition and extinction of human avoidance behavior and to demonstrate the role of safety signals in such behavior, highlighting the potential relevance of safety signals for cognitive therapies that focus on extinction learning to treat anxiety symptoms. PMID:25309373

Submarine Combat Systems Engineering Project Capstone Project

DTIC Science & Technology

2011-06-06

sonar , imaging, Electronic Surveillance (ES) and communications. These sensors passively detect contacts, which emit... passive sensors is included. A Search Detect Identify Track Decide Engage Assess 3 contact can be sensed by the system as either surface or... Detect Track Avoid Search Detect Identify Track Search Engage Assess Detect Track Avoid Search • SONAR •Imagery •TC • SONAR • SONAR •EW •Imagery •ESM

Syntactic Markedness and Language Acquisition.

ERIC Educational Resources Information Center

Mazurkewich, Irene

1985-01-01

Argues that Chomsky's theory of generative grammar provides a model for second language acquisition that meets the criteria of descriptive and exploratory adequacy in accounting for the language learning process. Illustrates this by presenting data on the acquisition of dative complements and dative questions in a passive context by second…

17 CFR 140.735-2a - Prohibited interests.

Code of Federal Regulations, 2010 CFR

2010-04-01

... acquired by inheritance, gift, stock split, involuntary stock dividend, merger, acquisition, or other... subject to the provisions of paragraphs (d) and (f) of this section. (d) Retention or passive acquisition... statement, SF 278 or SF 450, rather than when notification of the transaction is received. Acquisition by...

Chronic infusion of GABA and saline into the nucleus basalis magnocellularis of rats: II. Cognitive impairments.

PubMed

Majchrzak, M; Brailowsky, S; Will, B

1990-02-12

In order to assess sensorimotor and/or cognitive modifications following chronic inhibition of nucleus basalis magnocellularis (NBM) neurons, rats trained in two radial maze paradigms (the classical version of the test and a modified version introducing a one-hour delay between the fourth and the fifth choice) received chronic infusion of gamma-aminobutyric acid (GABA) into the NBM area. GABA (10 and 50 micrograms/microliters/h) was infused for 3 days into the NBM contralateral to their preferred turning direction in the radial maze. Simultaneously, saline (NaCl 0.9%; 1 microliter/h) was infused into the contralateral NBM. GABA and saline infusions were alternated for the subsequent 3-day period. One week later, we investigated the rats' ability to learn a multiple trial passive avoidance task. At the dose of 50 micrograms/microliters, GABA infusion produced (1) a turning bias ipsilateral to the side first infused with GABA, (2) transitory cognitive impairments in radial maze tasks and (3) a deficit in the acquisition of the passive avoidance task. At the dose of 10 micrograms/microliters, the same behavioral deficits were observed except that (1) the turning bias was reversed by the contralateral GABA infusion and (2) cognitive impairments in the radial maze were observed only when a delay was inserted between the fourth and the fifth choice. Histologically, we found a dose-dependent gliosis in the NBM area first infused with GABA. These data suggest a reactivity of the NBM to GABAergic manipulations and the intervention of this structure in both sensorimotor and cognitive processes involved in the radial maze paradigms.

SSP-002392, a new 5-HT4 receptor agonist, dose-dependently reverses scopolamine-induced learning and memory impairments in C57Bl/6 mice.

PubMed

Lo, Adrian C; De Maeyer, Joris H; Vermaercke, Ben; Callaerts-Vegh, Zsuzsanna; Schuurkes, Jan A J; D'Hooge, Rudi

2014-10-01

5-HT4 receptors (5-HT4R) are suggested to affect learning and memory processes. Earlier studies have shown that animals treated with 5-HT4R agonists, often with limited selectivity, show improved learning and memory with retention memory often being assessed immediately after or within 24 h after the last training session. In this study, we characterized the effect of pre-training treatment with the selective 5-HT4R agonist SSP-002392 on memory acquisition and the associated long-term memory retrieval in animal models of impaired cognition. Pre-training treatment with SSP-002392 (0.3 mg/kg, 1.5 mg/kg and 7.5 mg/kg p.o.) dose-dependently inhibited the cognitive deficits induced by scopolamine (0.5 mg/kg s.c.) in two different behavioral tasks: passive avoidance and Morris water maze. In the Morris water maze, spatial learning was significantly improved after treatment with SSP-002392 translating in an accelerated and more efficient localization of the hidden platform compared to scopolamine-treated controls. Moreover, retention memory was assessed 24 h (passive avoidance) and 72 h (Morris water maze) after the last training session of cognitive-impaired animals and this was significantly improved in animals treated with SSP-002392 prior to the training sessions. Furthermore, the effects of SSP-002392 were comparable to galanthamine hydrobromide. We conclude that SSP-002392 has potential as a memory-enhancing compound. Copyright © 2014 Elsevier Ltd. All rights reserved.

Emotional reactivity and cognitive performance in aversively motivated tasks: a comparison between four rat strains.

PubMed

van der Staay, F Josef; Schuurman, Teun; van Reenen, Cornelis G; Korte, S Mechiel

2009-12-15

Cognitive function might be affected by the subjects' emotional reactivity. We assessed whether behavior in different tests of emotional reactivity is correlated with performance in aversively motivated learning tasks, using four strains of rats generally considered to have a different emotional reactivity. The performance of male Brown Norway, Lewis, Fischer 344, and Wistar Kyoto rats in open field (OF), elevated plus-maze (EPM), and circular light-dark preference box (cLDB) tasks, which are believed to provide measures of emotional reactivity, was evaluated. Spatial working and reference memory were assessed in two aversively motivated learning and memory tasks: the standard and the "repeated acquisition" versions of the Morris water maze escape task, respectively. All rats were also tested in a passive avoidance task. At the end of the study, levels of serotonin (5-HT) and 5-hydroxyindoleacetic acid, and 5-HT turnover in the hippocampus and frontal cortex were determined. Strain differences showed a complex pattern across behavioral tests and serotonergic measures. Fischer 344 rats had the poorest performance in both versions of the Morris water escape task, whereas Brown Norway rats performed these tasks very well but the passive avoidance task poorly. Neither correlation analysis nor principal component analysis provided convincing support for the notion that OF, EPM, and cLDB tasks measure the same underlying trait. Our findings do not support the hypothesis that the level of emotional reactivity modulates cognitive performance in aversively motivated tasks. Concepts such as "emotional reactivity" and "learning and memory" cannot adequately be tapped with only one behavioral test. Our results emphasize the need for multiple testing.

Neuropathological Changes in Brain Cortex and Hippocampus in a Rat Model of Alzheimer’s Disease

PubMed Central

Nobakht, Maliheh; Hoseini, Seyed Mohammad; Mortazavi, Pejman; Sohrabi, Iraj; Esmailzade, Banafshe; Roosh, Nahid Rahbar; Omidzahir, Shila

2011-01-01

Background: Alzheimer’s disease (AD) is a neurodegenerative disorder with progressive loss of cognitive abilities and memory loss. The aim of this study was to compare neuropathological changes in hippocampus and brain cortex in a rat model of AD. Methods: Adult male Albino Wistar rats (weighing 250-300 g) were used for behavioral and histopathological studies. The rats were randomly assigned to three groups: control, sham and β-amyloid (Aβ) injection. For behavioral analysis, Y-maze and shuttle box were used, respectively at 14 and 16 days post-lesion. For histological studies, Nissl, modified Bielschowsky and modified Congo red staining were performed. The lesion was induced by injection of 4 µL of Aβ (1-40) into the hippocampal fissure. Results: In the present study, Aβ (1-40) injection into hippocampus could decrease the behavioral indexes and the number of CA1 neurons in hippocampus. Aβ injection CA1 caused Aβ deposition in the hippocampus and less than in cortex. We observed the loss of neurons in the hippocampus and cerebral cortex and certain subcortical regions. Y-maze test and single-trial passive avoidance test showed reduced memory retention in AD group. Conclusion: We found a significant decreased acquisition of passive avoidance and alternation behavior responses in AD group compared to control and sham group (P<0.0001). Compacted amyloid cores were present in the cerebral cortex, hippocampus and white matter, whereas, scattered amyloid cores were seen in cortex and hippocampus of AD group. Also, reduced neuronal density was indicated in AD group. PMID:21725500

Sexually dimorphic responses to neonatal basal forebrain lesions in mice: I. Behavior and neurochemistry.

PubMed

Arters, J; Hohmann, C F; Mills, J; Olaghere, O; Berger-Sweeney, J

1998-12-01

The nucleus basalis magnocellularis (nBM) provides the primary source of cholinergic input to the cortex. Neonatal lesions of the nBM produce transient reductions in cholinergic markers, persistent abnormalities in cortical morphology, and spatial navigation impairments in adult mice. The present study examined sex differences in the effects of an electrolytic nBM lesion on postnatal day 1 (PND 1) in mice on behavior and neurochemistry in adulthood. Mice were lesioned on PND 1 and tested at 8 weeks of age on a battery of behavioral tests including passive avoidance, cued and spatial tasks in the Morris water maze, simple and delayed nonmatch to sample versions of an odor discrimination task, and locomotor activity measurements. Following behavioral testing, mice were sacrificed for either morphological assessment or neurochemical analysis of a cholinergic marker or catecholamines. There were no lesion or sex differences in acquisition or retention of passive avoidance, performance of the odor discrimination tasks, or activity levels. Control mice showed a robust sex difference in performance of the spatial water maze task. The lesion produced a slight cued but more dramatic spatial navigation deficit in the water maze which affected only the male mice. Neurochemical analyses revealed no lesion-induced changes in either choline acetyltransferase activity or levels of norepinephrine or serotonin at the time of testing. The subsequent report shows a sex difference in lesion-induced changes in cortical morphology which suggests that sexually dimorphic cholinergic influences on cortical development are responsible for the behavioral deficits seen in this study.

Brief postnatal exposure to phenobarbital impairs passive-avoidance learning and sensorimotor gating in rats

PubMed Central

Gutherz, Samuel B.; Kulick, Catherine V.; Soper, Colin; Kondratyev, Alexei; Gale, Karen; Forcelli, Patrick A.

2014-01-01

Phenobarbital is the most commonly utilized drug for the treatment of neonatal seizures. However, mounting preclinical evidence suggests that even brief exposure to phenobarbital in the neonatal period can induce neuronal apoptosis, alterations in synaptic development, and long-lasting changes in behavioral functions. In the present report, we treated neonatal rat pups with phenobarbital and evaluated behavior in adulthood. Pups were treated initially with a loading dose (80mg/kg) on postnatal day (P)7 and with a lower dose (40 mg/kg) on P8 and P9. We examined sensorimotor gating (prepulse inhibition), passive avoidance, and conditioned place preference to cocaine when the animals reached adulthood. Consistent with our previous reports, we found that three days of neonatal exposure to phenobarbital significantly impaired prepulse inhibition as compared to vehicle-exposed control animals. Using a step-though passive avoidance paradigm, we found that animals exposed to phenobarbital as neonates and tested as adults showed significant deficits in passive avoidance retention as compared to matched controls, indicating impairment in associative memory and/or recall. Finally, we examined place preference conditioning in response to cocaine. Phenobarbital exposure did not alter the normal conditioned place preference associated with cocaine exposure. Our findings expand the profile of behavioral toxicity induced by phenobarbital. PMID:25112558

Brief postnatal exposure to phenobarbital impairs passive avoidance learning and sensorimotor gating in rats.

PubMed

Gutherz, Samuel B; Kulick, Catherine V; Soper, Colin; Kondratyev, Alexei; Gale, Karen; Forcelli, Patrick A

2014-08-01

Phenobarbital is the most commonly utilized drug for the treatment of neonatal seizures. However, mounting preclinical evidence suggests that even brief exposure to phenobarbital in the neonatal period can induce neuronal apoptosis, alterations in synaptic development, and long-lasting changes in behavioral functions. In the present report, we treated neonatal rat pups with phenobarbital and evaluated behavior in adulthood. Pups were treated initially with a loading dose (80 mg/kg) on postnatal day (P)7 and with a lower dose (40 mg/kg) on P8 and P9. We examined sensorimotor gating (prepulse inhibition), passive avoidance, and conditioned place preference for cocaine when the animals reached adulthood. Consistent with our previous reports, we found that three days of neonatal exposure to phenobarbital significantly impaired prepulse inhibition compared with vehicle-exposed control animals. Using a step-though passive avoidance paradigm, we found that animals exposed to phenobarbital as neonates and tested as adults showed significant deficits in passive avoidance retention compared with matched controls, indicating impairment in associative memory and/or recall. Finally, we examined place preference conditioning in response to cocaine. Phenobarbital exposure did not alter the normal conditioned place preference associated with cocaine exposure. Our findings expand the profile of behavioral toxicity induced by phenobarbital. Copyright © 2014 Elsevier Inc. All rights reserved.

The influence of leadership style on subordinates' attachment to the leader.

PubMed

Molero, Fernando; Moriano, Juan A; Shaver, Phillip R

2013-01-01

The aim of this research is to explore the extent to which employees establish attachment bonds with their leaders and the effects these bonds have on organizational outcomes. A sample of 225 participants reported on their supervisor's leadership style (transformational, transactional, or passive-avoidant), their attachment bonds to this supervisor (anxious or avoidant), and four organizational variables (subordinate's satisfaction, identification with the organization, extra effort, and perceived leadership effectiveness). Results, analyzed using a Partial Least Squares (PLS) approach, indicated that (a) transformational leadership was negatively associated with employees' insecure (anxious or avoidant) attachment to their leader; (b) passive/avoidant leadership was positively associated with subordinates' insecure attachment to their leader; (c) transactional leadership was positively associated with employee's anxious attachment but not with their avoidant attachment; (d) avoidant, but not anxious, attachment to the leader was negatively associated with employee satisfaction, perceived leader effectiveness, employee's extra effort, and organizational identification.

MDMA modifies active avoidance learning and recall in mice.

PubMed

Trigo, José Manuel; Cabrero-Castel, Araceli; Berrendero, Fernando; Maldonado, Rafael; Robledo, Patricia

2008-04-01

Several studies have suggested the existence of cognitive deficits after repeated or high doses of 3,4-methylenedioxymethamphetamine (MDMA) in humans and experimental animals. However, the extent of the impairments observed in learning or memory tasks remains unclear. The objective of this study was to evaluate the effects of different dosing regimens of MDMA on the ability of mice to learn and recall an active avoidance task. Animals were treated with MDMA (0, 1, 3, 10 and 30 mg/kg) under four different experimental conditions, and active avoidance acquisition and recall were evaluated. In experiments 1 and 2, MDMA was administered 1 h before different active avoidance training sessions. In experiments 3 and 4, mice received a repeated treatment with MDMA before or after active avoidance training, respectively. Changes in presynaptic striatal dopamine transporter (DAT) binding sites were evaluated at two different time points in animals receiving a high dose of MDMA (30 mg/kg) or saline twice a day over 4 days. MDMA administered before the active avoidance sessions interfered with the acquisition and the execution of a previously learned task. A repeated treatment with high doses of MDMA administered before training reduced acquisition of active avoidance in mice, while pre-treatment with both high and low doses of MDMA impaired recall of this task. A reduction in DAT binding was observed 4 days but not 23 days after the last MDMA administration. Acute MDMA modifies the acquisition and execution of active avoidance in mice, while repeated pre-treatment with MDMA impairs acquisition and recall of this task.

[Stimulation of D1-receptors improves passive avoidance learning of female rats during ovary cycle].

PubMed

Fedotova, Iu O; Sapronov, N S

2012-01-01

The involvement of D1-receptors in learning/memory processes during ovary cycle was assessed in the adult female rats. SKF-38393 (0,1 mg/kg, i.p.), D1-receptor agonist and SCH-23390 (0,1 mg/kg, i.p.), D1-receptor antagonist were injected chronically to adult female rats. Learning of these animals was assessed in different models: passive avoidance performance and Morris water maze. Chronic SKF-3839 administration to females resulted in the appearance of the passive avoidance performance in proestrous and estrous, as distinct from the control animals, but failed to change the dynamics of spatial learning in Morris water maze. Chronic SCH-23390 administration similarly impaired non-spatial and spatial learning in females during all phases of ovary cycle. The results of the study suggest modulating role of D1-receptors in learning/memory processes during ovary cycle in the adult female rats.

[Stimulation of D2-receptors improves passive avoidance learning in female rats].

PubMed

Fedotova, Iu O

2012-01-01

The involvement of D2-receptors in learning/memory processes during ovary cycle was assessed in the adult female rats. Quinperole (0,1 mg/kg, i.p.), D2-receptor agonist and sulpiride (10,0 mg/kg, i.p.), D2-receptor antagonist were injected chronically to adult female rats. Learning of these animals was assessed in different models: passive avoidance performance and Morris water maze. Chronic quinperole administration to females resulted in the appearance of the passive avoidance performance in proestrous and estrous, as distinct from the control animals. Also, quinperole improved spatial learning in proestrous and stimulated it in estrous in Morris water maze. Chronic sulpiride administration similarly impaired non-spatial and spatial learning in females during all phases of ovary cycle. The results of the study suggest modulating role of D2-receptors in learning/memory processes during ovary cycle in the adult female rats.

Electrical Stimulation of Lateral Habenula during Learning: Frequency-Dependent Effects on Acquisition but Not Retrieval of a Two-Way Active Avoidance Response

PubMed Central

Wetzel, Wolfram; Scheich, Henning; Ohl, Frank W.

2013-01-01

The lateral habenula (LHb) is an epithalamic structure involved in signaling reward omission and aversive stimuli, and it inhibits dopaminergic neurons during motivated behavior. Less is known about LHb involvement in the acquisition and retrieval of avoidance learning. Our previous studies indicated that brief electrical stimulation of the LHb, time-locked to the avoidance of aversive footshock (presumably during the positive affective “relief” state that occurs when an aversive outcome is averted), inhibited the acquisition of avoidance learning. In the present study, we used the same paradigm to investigate different frequencies of LHb stimulation. The effect of 20 Hz vs. 50 Hz vs. 100 Hz stimulation was investigated during two phases, either during acquisition or retrieval in Mongolian gerbils. The results indicated that 50 Hz, but not 20 Hz, was sufficient to produce a long-term impairment in avoidance learning, and was somewhat more effective than 100 Hz in this regard. None of the stimulation parameters led to any effects on retrieval of avoidance learning, nor did they affect general motor activity. This suggests that, at frequencies in excess of the observed tonic firing rates of LHb neurons (>1–20 Hz), LHb stimulation may serve to interrupt the consolidation of new avoidance memories. However, these stimulation parameters are not capable of modifying avoidance memories that have already undergone extensive consolidation. PMID:23840355

Effects of prior aversive experience upon retrograde amnesia induced by hypothermia.

PubMed

Jensen, R A; Riccio, D C; Gehres, L

1975-08-01

Two experiments examined the extent to which retrograde amnesia (RA) is attenuated by prior learning experiences. In Experiment 1, rats initially received either passive avoidance training in a step-through apparatus, exposure to the apparatus, or noncontingent footshock. When training on a second but different passive avoidance task was followed by hypothermia treatment, RA was obtained only in the latter two groups. In Experiment 2, one-way active avoidance training, yoked noncontingent shocks, or apparatus exposure constituted the initial experience. Subsequent step-down passive avoidance training and amnestic treatment resulted in memory loss for the prior apparatus exposure group, but not for either of the preshocked conditions. These experiments demonstrate that certain types of prior aversive experience can substantially modify the magnitude of RA, and, in conjunction with other familiarization studies, emphasize a paradox for interpretations of RA based solely upon CNS disruption. The possibility that hypothermia treatment serves as an important contextual or encoding cue necessary for memory retrieval was considered. It was suggested that prior experience may block RA by enabling rats to differentiate training and treatment conditions.

Development of a Naval Supply Systems Command Acquisition Supplement - A Business Practice Improvement

DTIC Science & Technology

2015-09-01

The information reviewed for this project will help the reader understand how acquisition rules and regulations flow down to the acquisition...ACQUISITIONS IN SUPPORT OF OPERATIONS IN AFGHANISTAN Aug-09 N Obsolete 09-26 PASSIVE RADIO FREQUENCY IDENTIFICATION ( RFID ) DFARS COMPLIANCE REPORTING...been made. Many of the instructions and publications refer readers to additional instructions and publications, and often reference specific policy

[A cross sectional study of passive smoking of non-smoking women and analysis of influence factors on women passive smoking].

PubMed

Han, Jing-Xiu; Ma, Ling; Zhang, Hong-Wei; Liu, Xi; Zheng, Su-hua; Gan, De-kun; Fang, Jun

2006-09-01

To fund out the state of passive smoking of non-smoking women and search for measures of controlling women passive smoking. 3500 non-smoking women in Beijing, Shanghai, Chengdu city were interviewed. Analyses were performed by chi2 test Fisher test and ANOVA test. 92.7% passive smoking women exposure to ETS at home, 40.8% at workplace. 38.9% exposed to ETS from birthday, and 42.3% from 18 - 30 age. The average exposure time of passive smoking is (1.17 +/- 1.10) hours per day. The proportion of passive-smoking time over 2 hours at home is higher than work place. In passive-smoking group, the proportion of 30 - 50 age group, secondary education, married, merchant/service, principal of units, and manufacture/transport workers were higher than non-smoking group. 97.5% think that passive smoking is harmful to health, and the proportion of thinking passive smoking has severe harm to health in non-passive-smoking group is higher than passive-smoking group. 70.0% open windows when someone smokes around her, but only 16.9% ask the smokers do not smoke around her forwardly. Suppose that someone were smoking around yourself, the consciousness of avoiding passive smoking forwardly in non-passive-smoking group is stronger than passive-smoking group. 95.1% believe the content of smoking-harm propagandized by medium. The main places of controlling passive smoking are the home and the department, commerce, service, and manufacture/ transport workplace. The rate of passive smoking was influenced by the consciousness of the serious level of harms by passive smoking. Propagandizing the serious harm of passive smoking by medium and strengthening the consciousness of avoiding passive smoking were one of feasible measures to lower the rate of smoking and passive smoking.

Behaviourally-inhibited temperament and female sex, two vulnerability factors for anxiety disorders, facilitate conditioned avoidance (also) in humans

PubMed Central

Sheynin, Jony; Beck, Kevin D.; Pang, Kevin C.H.; Servatius, Richard J.; Shikari, Saima; Ostovich, Jacqueline; Myers, Catherine E.

2014-01-01

Acquisition and maintenance of avoidance behaviour is a key feature of all human anxiety disorders. Animal models have been useful in understanding how anxiety vulnerability could translate into avoidance learning. For example, behaviourally-inhibited temperament and female sex, two vulnerability factors for clinical anxiety, are associated with faster acquisition of avoidance responses in rodents. However, to date, the translation of such empirical data to human populations has been limited since many features of animal avoidance paradigms are not typically captured in human research. Here, using a computer-based task that captures many features of rodent escape-avoidance learning paradigms, we investigated whether avoidance learning would be faster in humans with inhibited temperament and/or female sex and, if so, whether this facilitation would take the same form. Results showed that, as in rats, both vulnerability factors were associated with facilitated acquisition of avoidance behaviour in humans. Specifically, inhibited temperament was specifically associated with higher rate of avoidance responding, while female sex was associated with longer avoidance duration. These findings strengthen the direct link between animal avoidance work and human anxiety vulnerability, further motivating the study of animal models while also providing a simple testbed for a direct human testing. PMID:24412263

AMPA receptors mediate passive avoidance deficits induced by sleep deprivation.

PubMed

Dubiela, Francisco Paulino; Queiroz, Claudio Marcos; Moreira, Karin Di Monteiro; Nobrega, Jose N; Sita, Luciane Valéria; Tufik, Sergio; Hipolide, Debora Cristina

2013-11-15

The present study addressed the effects of sleep deprivation (SD) on AMPA receptor (AMPAR) binding in brain regions associated with learning and memory, and investigated whether treatment with drugs acting on AMPAR could prevent passive avoidance deficits in sleep deprived animals. [(3)H]AMPA binding and GluR1 in situ hybridization signals were quantified in different brain regions of male Wistar rats either immediately after 96 h of sleep deprivation or after 24h of sleep recovery following 96 h of sleep deprivation. Another group of animals were sleep deprived and then treated with either the AMPAR potentiator, aniracetam (25, 50 and 100mg/kg, acute administration) or the AMPAR antagonist GYKI-52466 (5 and 10mg/kg, acute and chronic administration) before passive avoidance training. Task performance was evaluated 2h and 24h after training. A significant reduction in [(3)H]AMPA binding was found in the hippocampal formation of SD animals, while no alterations were observed in GluR1 mRNA levels. The highest dose of aniracetam (100mg/kg) reverted SD-induced impairment of passive avoidance performance in both retention tests, whereas GYKI-52466 treatment had no effect. Pharmacological enhancement of AMPAR function may revert hippocampal-dependent learning impairments produced after SD. We argue that such effects might be associated with reduced AMPAR binding in the hippocampus of sleep deprived animals. Copyright © 2013 Elsevier B.V. All rights reserved.

Perinatal exposure to genistein, a soy phytoestrogen, improves spatial learning and memory but impairs passive avoidance learning and memory in offspring.

PubMed

Kohara, Yumi; Kuwahara, Rika; Kawaguchi, Shinichiro; Jojima, Takeshi; Yamashita, Kimihiro

2014-05-10

This study investigated the effects of perinatal genistein (GEN) exposure on the central nervous system of rat offspring. Pregnant dams orally received GEN (1 or 10 mg/kg/day) or vehicle (1 ml/kg/day) from gestation day 10 to postnatal day 14. In order to assess the effects of GEN on rat offspring, we used a battery of behavioral tests, including the open-field, elevated plus-maze, MAZE and step-through passive avoidance tests. MAZE test is an appetite-motivation test, and we used this mainly for assessing spatial learning and memory. In the MAZE test, GEN groups exhibited shorter latency from start to goal than the vehicle-treated group in both sexes. On the other hand, performances in the step-through passive avoidance test were non-monotonically inhibited by GEN in both sexes, and a significant difference was observed in low dose of the GEN-treated group compared to the vehicle-treated group in female rats. Furthermore, we found that perinatal exposure to GEN did not significantly alter locomotor activity or emotionality as assessed by the open-field and elevated-plus maze tests. These results suggest that perinatal exposure to GEN improved spatial learning and memory of rat offspring, but impaired their passive avoidance learning and memory. Copyright © 2014 Elsevier Inc. All rights reserved.

The effect of Vitamin E on learning and memory deficits in intrahippocampal kainate-induced temporal lobe epilepsy in rats.

PubMed

Kiasalari, Zahra; Khalili, Mohsen; Shafiee, Samaneh; Roghani, Mehrdad

2016-01-01

Since temporal lobe epilepsy (TLE) is associated with learning and memory impairment, we investigated the beneficial effect of Vitamin E on the impaired learning and memory in the intrahippocampal kainate model of TLE in rats. Rats were divided into sham, Vitamin E-treated sham, kainate, and Vitamin E-treated kainate. Intrahippocampal kainate was used for induction of epilepsy. Vitamin E was injected intraperitoneal (i.p.) at a dose of 200 mg/kg/day started 1 week before surgery until 1 h presurgery. Initial and step-through latencies in the passive avoidance test and alternation behavior percentage in Y-maze were finally determined in addition to measurement of some oxidative stress markers. Kainate injection caused a higher severity and rate of seizures and deteriorated learning and memory performance in passive avoidance paradigm and spontaneous alternation as an index of spatial recognition memory in Y-maze task. Intrahippocampal kainate also led to the elevation of malondialdehyde (MDA) and nitrite and reduced activity of superoxide dismutase (SOD). Vitamin E pretreatment significantly attenuated severity and incidence rate of seizures, significantly improved retrieval and recall in passive avoidance, did not ameliorate spatial memory deficit in Y-maze, and lowered MDA and enhanced SOD activity. Vitamin E improves passive avoidance learning and memory and part of its beneficial effect is due to its potential to mitigate hippocampal oxidative stress.

Eventive and Stative Passives in Spanish L2 Acquisition: A Matter of Aspect

ERIC Educational Resources Information Center

De Garavito, Joyce Bruhn; Valenzuela, Elena

2008-01-01

This paper reports on an empirical study that examined knowledge of eventive and stative passives in the L2 Spanish grammar of L1 speakers of English. Although the two types of passive exist in English, the difference between them is not signaled in any specific way. In Spanish, in contrast, the distinction is marked by the choice of copula: "ser"…

Evaluation of an image-based tracking workflow using a passive marker and resonant micro-coil fiducials for automatic image plane alignment in interventional MRI.

PubMed

Neumann, M; Breton, E; Cuvillon, L; Pan, L; Lorenz, C H; de Mathelin, M

2012-01-01

In this paper, an original workflow is presented for MR image plane alignment based on tracking in real-time MR images. A test device consisting of two resonant micro-coils and a passive marker is proposed for detection using image-based algorithms. Micro-coils allow for automated initialization of the object detection in dedicated low flip angle projection images; then the passive marker is tracked in clinical real-time MR images, with alternation between two oblique orthogonal image planes along the test device axis; in case the passive marker is lost in real-time images, the workflow is reinitialized. The proposed workflow was designed to minimize dedicated acquisition time to a single dedicated acquisition in the ideal case (no reinitialization required). First experiments have shown promising results for test-device tracking precision, with a mean position error of 0.79 mm and a mean orientation error of 0.24°.

Evaluation of acute tacrine treatment on passive-avoidance response, open-field behavior, and toxicity in 17- and 30-day-old mice.

PubMed

Pan, S Y; Han, Y F; Yu, Z L; Yang, R; Dong, H; Ko, K M

2006-09-01

The potential of tacrine in altering cognitive/behavioral function as well as in causing toxicity was evaluated in mice of 17 and 30 days of age. Cognitive and behavioral studies were performed using a step-through passive avoidance task and a habituation open-field test with a 24-h retention interval. Tacrine was subcutaneously injected (1.25-80 micro mol/kg) 30 min prior to the first session of both tests. During the training session in step-through task, tacrine treatment dose-dependently decreased the number of footshocks, with IC(50) values being 7.8 and 23.3 micro mol/kg in 17- and 30-day-old mice, respectively. Treatment with tacrine at a low dose (5 micro mol/kg) significantly prolonged the retention latency in 17-day-old mice only, but it shortened the retention latency at high doses of 20 and 40 micro mol/kg in 17- and 30-day-old, respectively. During the acquisition session in the open-field test, tacrine treatment dose-dependently decreased the locomotor activity in 17- and 30-day-old mice, with IC(50) values being 15.1 and 24.7 micro mol/kg, respectively. High doses of tacrine invariably increased the locomotor activity during the recall session. Tacrine treatment at a dose of 40 micro mol/kg caused a significant increase in serum alanine aminotransferase activity in 17- and 30-day-old mice at 6 h post-dosing, with the extent of stimulation in 30-day-old mice being more prominent. In conclusion, tacrine was more potent in enhancing/disrupting the cognitive function, inhibiting locomotor activity as well as in causing hepatotoxicity in 17-day-old than in 30-day-old mice.

Emotional reactivity and cognitive performance in aversively motivated tasks: a comparison between four rat strains

PubMed Central

2009-01-01

Background Cognitive function might be affected by the subjects' emotional reactivity. We assessed whether behavior in different tests of emotional reactivity is correlated with performance in aversively motivated learning tasks, using four strains of rats generally considered to have a different emotional reactivity. Methods The performance of male Brown Norway, Lewis, Fischer 344, and Wistar Kyoto rats in open field (OF), elevated plus-maze (EPM), and circular light-dark preference box (cLDB) tasks, which are believed to provide measures of emotional reactivity, was evaluated. Spatial working and reference memory were assessed in two aversively motivated learning and memory tasks: the standard and the "repeated acquisition" versions of the Morris water maze escape task, respectively. All rats were also tested in a passive avoidance task. At the end of the study, levels of serotonin (5-HT) and 5-hydroxyindoleacetic acid, and 5-HT turnover in the hippocampus and frontal cortex were determined. Results Strain differences showed a complex pattern across behavioral tests and serotonergic measures. Fischer 344 rats had the poorest performance in both versions of the Morris water escape task, whereas Brown Norway rats performed these tasks very well but the passive avoidance task poorly. Neither correlation analysis nor principal component analysis provided convincing support for the notion that OF, EPM, and cLDB tasks measure the same underlying trait. Conclusions Our findings do not support the hypothesis that the level of emotional reactivity modulates cognitive performance in aversively motivated tasks. Concepts such as "emotional reactivity" and "learning and memory" cannot adequately be tapped with only one behavioral test. Our results emphasize the need for multiple testing. PMID:20003525

Acquaintance Rape: Effective Avoidance Strategies.

ERIC Educational Resources Information Center

Levine-MacCombie, Joyce; Koss, Mary P.

1986-01-01

Determined that acknowledged and unacknowledged acquaintance rape victims and rape avoiders could be discriminated by situational variables and response strategies. Avoiders were less likely to have experienced passive or internalizing emotions at the time of the assault, perceived the assault as less violent, and were more likely to have utilized…

[Nootropic and analgesic effects of Semax following different routes of administration].

PubMed

Manchenko, D M; Glazova, N Iu; Levitskaia, N G; Andreeva, L A; Kamenskiĭ, A A; Miasoedov, N F

2010-10-01

Heptapeptide Semax (MEHFPGP) is the fragment of ACTH(4-10) analogue with prolonged neurotropic activity. The aim of the present work was to study the Semax effects on learning capability and pain sensitivity in white rats following intraperitoneal and intranasal administration in different doses. Semax nootropic effects were studied in the test of acquisition of passive avoidance task. Pain sensitivity was estimated in Randall-Selitto paw-withdrawal test. It was shown that Semax exerts nootropic and analgesic activities following intraperitoneal administration. Analysis of dependence of these effects on dose resulted in different dose-response curves. Following intranasal administration, Semax was more potent in learning improvement compared to intraperitoneal administration. The peptide failed to affect the animal pain sensitivity following intranasal administration as opposed to intraperitoneal administration. The data obtained suggest different mechanisms and brain structures involved in realization of the nootropic and analgesic effects of Semax.

Internalism, Externalism and Coding

ERIC Educational Resources Information Center

Carr, Philip

2007-01-01

I examine some of the issues connected with the internalist/externalist distinction in work on the ontology of language. I note that Chomskyan radical internalism necessarily leads to a passive conception of child language acquisition. I reject that passive conception, and support current versions of constructivism [Tomasello, M., 2001. "The…

Armstrong Flight Research Center Flight Test Capabilities and Opportunities for the Applications of Wireless Data Acquisition Systems

NASA Technical Reports Server (NTRS)

Hang, Richard

2015-01-01

The presentation will overview NASA Armstrong Flight Research Centers flight test capabilities, which can provide various means for flight testing of passive and active wireless sensor systems, also, it will address the needs of the wireless data acquisition solutions for the centers flight instrumentation issues such as additional weight caused by added instrumentation wire bundles, connectors, wire cables routing, moving components, etc., that the Passive Wireless Sensor Technology Workshop may help. The presentation shows the constraints and requirements that the wireless sensor systems will face in the flight test applications.

Advances in real-time millimeter-wave imaging radiometers for avionic synthetic vision

NASA Astrophysics Data System (ADS)

Lovberg, John A.; Chou, Ri-Chee; Martin, Christopher A.; Galliano, Joseph A., Jr.

1995-06-01

Millimeter-wave imaging has advantages over conventional visible or infrared imaging for many applications because millimeter-wave signals can travel through fog, snow, dust, and clouds with much less attenuation than infrared or visible light waves. Additionally, passive imaging systems avoid many problems associated with active radar imaging systems, such as radar clutter, glint, and multi-path return. ThermoTrex Corporation previously reported on its development of a passive imaging radiometer that uses an array of frequency-scanned antennas coupled to a multichannel acousto-optic spectrum analyzer (Bragg-cell) to form visible images of a scene through the acquisition of thermal blackbody radiation in the millimeter-wave spectrum. The output from the Bragg cell is imaged by a standard video camera and passed to a computer for normalization and display at real-time frame rates. An application of this system is its incorporation as part of an enhanced vision system to provide pilots with a synthetic view of a runway in fog and during other adverse weather conditions. Ongoing improvements to a 94 GHz imaging system and examples of recent images taken with this system will be presented. Additionally, the development of dielectric antennas and an electro- optic-based processor for improved system performance, and the development of an `ultra- compact' 220 GHz imaging system will be discussed.

Active versus Passive Training of a Complex Bimanual Task: Is Prescriptive Proprioceptive Information Sufficient for Inducing Motor Learning?

PubMed Central

Beets, Iseult A. M.; Macé, Marc; Meesen, Raf L. J.; Cuypers, Koen; Levin, Oron; Swinnen, Stephan P.

2012-01-01

Perceptual processes play an important role in motor learning. While it is evident that visual information greatly contributes to learning new movements, much less is known about provision of prescriptive proprioceptive information. Here, we investigated whether passive (proprioceptively-based) movement training was comparable to active training for learning a new bimanual task. Three groups practiced a bimanual coordination pattern with a 1∶2 frequency ratio and a 90° phase offset between both wrists with Lissajous feedback over the course of four days: 1) passive training; 2) active training; 3) no training (control). Retention findings revealed that passive as compared to active training resulted in equally successful acquisition of the frequency ratio but active training was more effective for acquisition of the new relative phasing between the limbs in the presence of augmented visual feedback. However, when this feedback was removed, performance of the new relative phase deteriorated in both groups whereas the frequency ratio was better preserved. The superiority of active over passive training in the presence of augmented feedback is hypothesized to result from active involvement in processes of error detection/correction and planning. PMID:22666379

Active and Passive Spatial Learning in Human Navigation: Acquisition of Graph Knowledge

ERIC Educational Resources Information Center

Chrastil, Elizabeth R.; Warren, William H.

2015-01-01

It is known that active exploration of a new environment leads to better spatial learning than does passive visual exposure. We ask whether specific components of active learning differentially contribute to particular forms of spatial knowledge--the "exploration-specific learning hypothesis". Previously, we found that idiothetic…

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

PubMed

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

2016-11-09

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

a Comparison Between Active and Passive Techniques for Underwater 3d Applications

NASA Astrophysics Data System (ADS)

Bianco, G.; Gallo, A.; Bruno, F.; Muzzupappa, M.

2011-09-01

In the field of 3D scanning, there is an increasing need for more accurate technologies to acquire 3D models of close range objects. Underwater exploration, for example, is very hard to perform due to the hostile conditions and the bad visibility of the environment. Some application fields, like underwater archaeology, require to recover tridimensional data of objects that cannot be moved from their site or touched in order to avoid possible damages. Photogrammetry is widely used for underwater 3D acquisition, because it requires just one or two digital still or video cameras to acquire a sequence of images taken from different viewpoints. Stereo systems composed by a pair of cameras are often employed on underwater robots (i.e. ROVs, Remotely Operated Vehicles) and used by scuba divers, in order to survey archaeological sites, reconstruct complex 3D structures in aquatic environment, estimate in situ the length of marine organisms, etc. The stereo 3D reconstruction is based on the triangulation of corresponding points on the two views. This requires to find in both images common points and to match them (correspondence problem), determining a plane that contains the 3D point on the object. Another 3D technique, frequently used in air acquisition, solves this point-matching problem by projecting structured lighting patterns to codify the acquired scene. The corresponding points are identified associating a binary code in both images. In this work we have tested and compared two whole-field 3D imaging techniques (active and passive) based on stereo vision, in underwater environment. A 3D system has been designed, composed by a digital projector and two still cameras mounted in waterproof housing, so that it can perform the various acquisitions without changing the configuration of optical devices. The tests were conducted in a water tank in different turbidity conditions, on objects with different surface properties. In order to simulate a typical seafloor, we used various concentrations of clay. The performances of the two techniques are described and discussed. In particular, the point clouds obtained are compared in terms of number of acquired 3D points and geometrical deviation.

Does Experiential Avoidance Mediate the Effects of Maladaptive Coping Styles on Psychopathology and Mental Health?

ERIC Educational Resources Information Center

Fledderus, Martine; Bohlmeijer, Ernst T.; Pieterse, Marcel E.

2010-01-01

Experiential avoidance (EA) is considered a risk factor for psychopathology. This study explores whether EA mediates the relationship between maladaptive coping styles (palliative, avoidance, and passive coping) and psychopathology and positive mental health. A total of 93 adults with mild to moderate psychological distress completed measures…

Direction of attention bias to threat relates to differences in fear acquisition and extinction in anxious children.

PubMed

Waters, Allison M; Kershaw, Rachel

2015-01-01

Anxious children show attention biases towards and away from threat stimuli. Moreover, threat avoidance compared to vigilance predicts a poorer outcome from exposure-based treatments, such as cognitive-behavioural therapy (CBT), yet the mechanisms underlying this differential response are unclear. Pavlovian fear conditioning is a widely accepted theory to explain the acquisition and extinction of fear, including exposure-based treatments, such as CBT. In typical fear conditioning experiments, anxious children have shown larger physiological responses to an aversive unconditional stimulus (i.e., US on CS+ trials) and to non-reinforced stimuli (CS-) during fear acquisition and to both CSs during fear extinction compared to non-anxious peers. This study examined whether threat avoidance compared to threat vigilance was related to differences in fear acquisition and extinction in anxious children. Thirty-four clinically-anxious children completed a visual probe task including angry-neutral face pairs to determine the direction of threat attention bias as well as a discriminant conditioning and extinction task in which a geometric shape CS+ was paired with an aversive tone US, while the CS- geometric shape was always presented alone during acquisition trials. Both CSs were presented alone during extinction trials. Fear acquisition and extinction were indexed by skin conductance responses (SCR) and subjective measures. Children were classified as threat vigilant (N = 18) and threat avoidant (n = 16) based on the direction of threat attention bias on the visual probe task. During acquisition, threat avoidant relative to threat vigilant anxious children displayed larger orienting SCRs to both CSs during the first block of trials and larger third interval SCRs to the US on CS+ trials as well as on CS- trials. During extinction, threat avoidant anxious children showed delayed extinction of SCRs to both the CS+ and CS- and reported higher subjective anxiety ratings after extinction compared to threat vigilant anxious children. Threat avoidant anxious children may be more reactive physiologically to novel cues and to stimuli that become associated with threat and this may interfere with extinction learning. These findings could help explain previous evidence that threat avoidant anxious children do not respond as well as threat vigilant anxious children to exposure-based CBT. Copyright © 2014 Elsevier Ltd. All rights reserved.

Active and Passive Spatial Learning in Human Navigation: Acquisition of Survey Knowledge

ERIC Educational Resources Information Center

Chrastil, Elizabeth R.; Warren, William H.

2013-01-01

It seems intuitively obvious that active exploration of a new environment would lead to better spatial learning than would passive visual exposure. It is unclear, however, which components of active learning contribute to spatial knowledge, and previous literature is decidedly mixed. This experiment tests the contributions of 4 components to…

3-Year-Olds' Comprehension, Production, and Generalization of Sesotho Passives

ERIC Educational Resources Information Center

Demuth, Katherine; Moloi, Francina; Machobane, Malillo

2010-01-01

Researchers have long been puzzled by the challenge English passive constructions present for language learners, with adult-like comprehension and production emerging only around the age of 5. It has therefore been of significant interest that researchers of other languages, including the Bantu language Sesotho, have reported acquisition of the…

Immediate Extinction Attenuates Spontaneous Recovery and Reinstatement in a Passive Avoidance Paradigm.

PubMed

Briggs, James F; Fava, Devin A

2016-08-01

Recent research suggests that extinction occurring shortly after fear conditioning attenuates spontaneous recovery and reinstatement of fear. Two experiments investigated whether immediate extinction would prevent spontaneous recovery and reinstatement of fear using a passive avoidance paradigm. In Experiment 1, naive female adult rats (N = 40) received extinction training either immediately or 24 hours (delayed) after fear conditioning. Both extinction groups showed a significant reduction in fear at a 1-day test. At a 15-day test, spontaneous recovery was observed in the delayed extinction group while the immediate extinction group continued to show significant extinction. In Experiment 2, using a naive group of adult female rats (N = 16), the extinction result was replicated in both the immediate and delayed extinction groups at the 1-day interval. Reinstatement of fear, elicited by foot-shock in a neutral environment, was observed for the delayed group but not for the immediate group. By utilizing the passive-avoidance paradigm, these experiments replicate and extend previous findings that immediate extinction attenuates spontaneous recovery and reinstatement of fear. © The Author(s) 2016.

Passive Avoidance Is Linked to Impaired Fear Extinction in Humans

ERIC Educational Resources Information Center

Cornwell, Brian R.; Overstreet, Cassie; Krimsky, Marissa; Grillon, Christian

2013-01-01

Conventional wisdom dictates we must face our fears to conquer them. This idea is embodied in exposure-based treatments for anxiety disorders, where the intent of exposure is to reverse a history of avoidant behavior that is thought to fuel a patient's irrational fears. We tested in humans the relationship between fear and avoidance by combining…

A Magnetic Field Response Recorder: A New Tool for Measurement Acquisition

NASA Technical Reports Server (NTRS)

Woodard, Stanley E.; Taylor, Bryant D.

2006-01-01

A magnetic field response recorder was developed to facilitate a measurement acquisition method that uses magnetic fields to power and to interrogate all sensors. Sensors are designed as electrically passive inductive-capacitive or passive inductive-capacitive-resistive circuits that produce magnetic field responses when electrically activated by oscillating magnetic fields. When electrically activated, the sensor's magnetic field response attributes (frequency, amplitude and bandwidth) correspond to the one or more physical states that each sensor measures. The response recorder makes it possible to simultaneously measure two unrelated physical properties using this class of sensors. The recorder is programmable allowing it to analyze one or more response attributes simultaneously. A single sensor design will be used to demonstrate that the acquisition method and the sensor example can be used to for all phases of a component's life from manufacturing to damage that can destroy it.

Airborne Active and Passive L-Band Observations in Soil Moisture Active Passive Validation Experiment 2012 (SMAPVEX12)

NASA Astrophysics Data System (ADS)

Colliander, A.; Yueh, S. H.; Chazanoff, S.; Jackson, T. J.; McNairn, H.; Bullock, P.; Wiseman, G.; Berg, A. A.; Magagi, R.; Njoku, E. G.

2012-12-01

NASA's (National Aeronautics and Space Administration) Soil Moisture Active Passive (SMAP) Mission is scheduled for launch in October 2014. The objective of the mission is global mapping of soil moisture and freeze/thaw state. Merging of active and passive L-band observations of the mission will enable unprecedented combination of accuracy, resolution, coverage and revisit-time for soil moisture and freeze/thaw state retrieval. For pre-launch algorithm development and validation the SMAP project and NASA coordinated a field campaign named as SMAPVEX12 (Soil Moisture Active Passive Validation Experiment 2012) together with Agriculture and Agri-Food Canada in the vicinity of Winnipeg, Canada in June-July, 2012. The main objective of SMAPVEX12 was acquisition of data record that features long-time series with varying soil moisture and vegetation conditions (for testing the application of time-series approach) over aerial domain of multiple parallel lines (for spatial disaggregation studies). The coincident active and passive L-band data were acquired using the Passive Active L-band System (PALS), which is an airborne radiometer and radar developed for testing L-band retrieval algorithms. For SMAPVEX12 PALS was installed on a Twin Otter aircraft. The flight plan included flights at two altitudes. The higher altitude was used to map the whole experiment domain and the lower altitude was used to obtain measurements over a specific set of field sites. The spatial resolution (and swath) of the radar and radiometer from low altitude was about 600 m and from high altitude about 1500 m. The PALS acquisitions were complemented with high resolution (~10 m) L-band SAR measurements carried out by UAVSAR instrument on-board G-III aircraft. The campaign ran from June 7 until July 19. The PALS instrument conducted 17 brightness temperature and backscatter measurement flights and the UAVSAR conducted 14 backscatter measurement flights. The airborne data acquisition was supported by extensive ground truth collection. In situ soil moisture and vegetation biomass and structure of the mixed cropland, pasture and forest landscape of the experiment domain was gathered synchronously with the airborne acquisitions. The conditions included wide range in both soil moisture and vegetation density. This paper presents an overview of the SMAPVEX12 campaign and an evaluation of the quality of the PALS measurements. The calibration methodology based on the internal calibration, lake over-flights and specific calibration maneuvers were utilized before and after each day's science flights to guarantee accuracy and consistency of the measurements over the campaign duration. As a consequence the correspondence of the airborne acquisitions with the spatial and temporal evolution of the geophysical variables over the experiment domain meets the requirement set by the objectives of the campaign. Acknowledgement: This work was carried out in Jet Propulsion Laboratory, California Institute of Technology under contract with National Aeronautics and Space Administration. USDA is an equal opportunity provider and employer.

Now You See it, Now You Don't: Age Differences in Affective Reactivity to Social Tensions

PubMed Central

Charles, Susan Turk; Piazza, Jennifer R.; Luong, Gloria; Almeida, David M.

2009-01-01

When faced with interpersonal conflict, older adults report using passive strategies more often than do younger adults. They also report less affective reactivity in response to these tensions. We examined whether the use of passive strategies may explain age-related reductions in affective reactivity to interpersonal tensions. Over eight consecutive evenings, participants (N = 1031, 25 – 74 years-old) reported daily negative affect and the occurrence of tense situations where they had an argument or avoided an argument. Older age was related to less affective reactivity when people decided to avoid an argument but was unrelated to affective reactivity when people engaged in arguments. Findings suggest that avoidance of negative situations may largely underlie age-related benefits in affective well-being. PMID:19739920

Sensor Management for Tactical Surveillance Operations

DTIC Science & Technology

2007-11-01

active and passive sonar for submarine and tor- pedo detection, and mine avoidance. [range, bearing] range 1.8 km to 55 km Active or Passive AN/SLQ-501...finding (DF) unit [bearing, classification] maximum range 1100 km Passive Cameras (day- light/ night- vision) ( video & still) Record optical and...infrared still images or motion video of events for near-real time assessment or long term analysis and archiving. Range is limited by the image resolution

37 CFR 10.64 - Avoiding acquisition of interest in litigation or proceeding before the Office.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Avoiding acquisition of interest in litigation or proceeding before the Office. 10.64 Section 10.64 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE REPRESENTATION OF OTHERS BEFORE THE PATENT AND TRADEMARK OFFICE Patent and...

Obstacle Avoidance and Target Acquisition for Robot Navigation Using a Mixed Signal Analog/Digital Neuromorphic Processing System

PubMed Central

Milde, Moritz B.; Blum, Hermann; Dietmüller, Alexander; Sumislawska, Dora; Conradt, Jörg; Indiveri, Giacomo; Sandamirskaya, Yulia

2017-01-01

Neuromorphic hardware emulates dynamics of biological neural networks in electronic circuits offering an alternative to the von Neumann computing architecture that is low-power, inherently parallel, and event-driven. This hardware allows to implement neural-network based robotic controllers in an energy-efficient way with low latency, but requires solving the problem of device variability, characteristic for analog electronic circuits. In this work, we interfaced a mixed-signal analog-digital neuromorphic processor ROLLS to a neuromorphic dynamic vision sensor (DVS) mounted on a robotic vehicle and developed an autonomous neuromorphic agent that is able to perform neurally inspired obstacle-avoidance and target acquisition. We developed a neural network architecture that can cope with device variability and verified its robustness in different environmental situations, e.g., moving obstacles, moving target, clutter, and poor light conditions. We demonstrate how this network, combined with the properties of the DVS, allows the robot to avoid obstacles using a simple biologically-inspired dynamics. We also show how a Dynamic Neural Field for target acquisition can be implemented in spiking neuromorphic hardware. This work demonstrates an implementation of working obstacle avoidance and target acquisition using mixed signal analog/digital neuromorphic hardware. PMID:28747883

Obstacle Avoidance and Target Acquisition for Robot Navigation Using a Mixed Signal Analog/Digital Neuromorphic Processing System.

PubMed

Milde, Moritz B; Blum, Hermann; Dietmüller, Alexander; Sumislawska, Dora; Conradt, Jörg; Indiveri, Giacomo; Sandamirskaya, Yulia

2017-01-01

Neuromorphic hardware emulates dynamics of biological neural networks in electronic circuits offering an alternative to the von Neumann computing architecture that is low-power, inherently parallel, and event-driven. This hardware allows to implement neural-network based robotic controllers in an energy-efficient way with low latency, but requires solving the problem of device variability, characteristic for analog electronic circuits. In this work, we interfaced a mixed-signal analog-digital neuromorphic processor ROLLS to a neuromorphic dynamic vision sensor (DVS) mounted on a robotic vehicle and developed an autonomous neuromorphic agent that is able to perform neurally inspired obstacle-avoidance and target acquisition. We developed a neural network architecture that can cope with device variability and verified its robustness in different environmental situations, e.g., moving obstacles, moving target, clutter, and poor light conditions. We demonstrate how this network, combined with the properties of the DVS, allows the robot to avoid obstacles using a simple biologically-inspired dynamics. We also show how a Dynamic Neural Field for target acquisition can be implemented in spiking neuromorphic hardware. This work demonstrates an implementation of working obstacle avoidance and target acquisition using mixed signal analog/digital neuromorphic hardware.

Cross State-dependent Learning Interaction Between Scopolamine and Morphine in Mice: The Role of Dorsal Hippocampus

PubMed Central

Maleki, Morteza; Hassanpour-Ezatti, Majid; Navaeian, Majid

2017-01-01

Introduction: The current study aimed at investigating the existence of the cross state-dependent learning between morphine and scopolamine (SCO) in mice by passive avoidance method, pointing to the role of CA1 area. Methods: The effects of pre-training SCO (0.75, 1.5, and 3 μg, Intra-CA1), or morphine (1, 3, and 6 mg/kg, intraperitoneal (i.p.) was evaluated on the retrieval of passive avoidance learning using step-down task in mice (n=10). Then, the effect of pretest administration of morphine (1.5, 3, and 6 mg/kg, i.p.) was examined on passive avoidance retrieval impairment induced by pre-training SCO (3 μg/mice, Intra-CA1). Next, the effect of pretest Intra-CA1 injection of scopolamine (0.75, 1.5, and 3 μg/mice) was evaluated on morphine (6 mg/kg, i.p.) pre-training deficits in this task in mice. Results: The pre-training Intra-CA1 injection of scopolamine (1.5 and 3 μg/mouse), or morphine (3 and 6 mg/kg, i.p.) impaired the avoidance memory retrieval when it was tested 24 hours later. Pretest injection of both drugs improved its pre-training impairing effects on mice memory. Moreover, the amnesia induced by the pre-training injections of scopolamine (3 μg/mice) was restored significantly (P<0.01) by pretest injections of morphine (3 and 6 mg/kg, i.p.). Similarly, pretest injection of scopolamine (3 μg/mice) restored amnesia induced by the pre-training injections of morphine (6 mg/kg, i.p.), significantly (P<0.01). Conclusion: The current study findings indicated a cross state-dependent learning between SCO and morphine at CA1 level. Therefore, it seems that muscarinic and opioid receptors may act reciprocally on modulation of passive avoidance memory retrieval, at the level of dorsal hippocampus, in mice. PMID:28781727

Preschoolers' Sensitivity to the Maxims of the Cooperative Principle: Scaffolds and Developmental Trends

ERIC Educational Resources Information Center

Skarakis-Doyle, Elizabeth; Izaryk, Kristen; Campbell, Wenonah; Terry, Alexandra

2014-01-01

This study examines preschoolers' acquisition of the maxims of the Cooperative Principle and the sociocognitive scaffolds that support this acquisition. In Study 1, 84 children between 3 and 5 years old were required to make passive judgments of violations of the Cooperative Principle. Results showed that children consistently identified…

Nitric oxide facilitates active avoidance learning via enhancement of glutamate levels in the hippocampal dentate gyrus.

PubMed

Wang, Shi; Pan, De-Xi; Wang, Dan; Wan, Peng; Qiu, De-Lai; Jin, Qing-Hua

2014-09-01

The hippocampus is a key structure for learning and memory in mammals, and long-term potentiation (LTP) is an important cellular mechanism responsible for learning and memory. Despite a number of studies indicating that nitric oxide (NO) is involved in the formation and maintenance of LTP as a retrograde messenger, few studies have used neurotransmitter release as a visual indicator in awake animals to explore the role of NO in learning-dependent long-term enhancement of synaptic efficiency. Therefore, in the present study, the effects of l-NMMA (a NO synthase inhibitor) and SNP (a NO donor) on extracellular glutamate (Glu) concentrations and amplitudes of field excitatory postsynaptic potential (fEPSP) were measured in the hippocampal dentate gyrus (DG) region during the acquisition and extinction of active-avoidance behavior in freely-moving conscious rats. In the control group, the extracellular concentration of Glu in the DG was significantly increased during the acquisition of active-avoidance behavior and gradually returned to baseline levels following extinction training. In the experimental group, the change in Glu concentration was significantly reduced by local microinjection of l-NMMA, as was the acquisition of the active-avoidance behavior. In contrast, the change in Glu concentration was significantly enhanced by SNP, and the acquisition of the active-avoidance behavior was significantly accelerated. Furthermore, in all groups, the changes in extracellular Glu were accompanied by corresponding changes in fEPSP amplitude and active-avoidance behavior. Our results suggest that NO in the hippocampal DG facilitates active avoidance learning via enhancements of glutamate levels and synaptic efficiency in rats. Copyright © 2014 Elsevier B.V. All rights reserved.

Exaggerated acquisition and resistance to extinction of avoidance behavior in treated heroin-dependent males

PubMed Central

Sheynin, Jony; Moustafa, Ahmed A.; Beck, Kevin D.; Servatius, Richard J.; Casbolt, Peter A.; Haber, Paul; Elsayed, Mahmoud; Hogarth, Lee; Myers, Catherine E.

2015-01-01

Objective Addiction is often conceptualized as a behavioral strategy for avoiding negative experiences. In rodents, opioid intake has been associated with abnormal acquisition and extinction of avoidance behavior. Here, we tested the hypothesis that these findings would generalize to human opioid-dependent subjects. Method Adults meeting DSM-IV criteria for heroin-dependence and treated with opioid medication (n=27), and healthy controls (n=26), were recruited between March–October 2013 and given a computer-based task to assess avoidance behavior. On this task, subjects controlled a spaceship and could either gain points by shooting an enemy spaceship, or hide in safe areas to avoid on-screen aversive events. Results While groups did not differ on escape responding (hiding) during the aversive event, heroin-dependent males (but not females) made more avoidance responses during a warning signal that predicted the aversive event (ANOVA, sex × group interaction, p=0.007). This group was also slower to extinguish the avoidance response when the aversive event no longer followed the warning signal (p=0.011). This behavioral pattern resulted in reduced opportunity to obtain reward without reducing risk of punishment. Results suggest that differences in avoidance behavior cannot be easily explained by impaired task performance or by exaggerated motor activity in male patients. Conclusion This study provides evidence for abnormal acquisition and extinction of avoidance behavior in opioid-dependent patients. Interestingly, data suggest abnormal avoidance is demonstrated only by male patients. Findings shed light on cognitive and behavioral manifestations of opioid addiction, and may facilitate development of therapeutic approaches to help affected individuals. PMID:27046310

In defense of the passive voice in medical writing.

PubMed

Minton, Timothy D

2015-01-01

Few medical journals specifically instruct authors to use the active voice and avoid the passive voice, but advice to that effect is common in the large number of stylebooks and blogs aimed at medical and scientific writers. Such advice typically revolves around arguments that the passive voice is less clear, less direct, and less concise than the active voice, that it conceals the identity of the person(s) performing the action(s) described, that it obscures meaning, that it is pompous, and that the high rate of passive-voice usage in scientific writing is a result of conformity to an established and old-fashioned style of writing. Some of these arguments are valid with respect to specific examples of passive-voice misuse by some medical (and other) writers, but as arguments for avoiding passive-voice use in general, they are seriously flawed. In addition, many of the examples that stylebook writers give of inappropriate use are actually much more appropriate in certain contexts than the active-voice alternatives they provide. In this review, I examine the advice offered by anti-passive writers, along with some of their examples of "inappropriate" use, and argue that the key factor in voice selection is sentence word order as determined by the natural tendency in English for the topic of discourse ("old" information) to take subject position and for "new" information to come later. Authors who submit to this natural tendency will not have to worry much about voice selection, because it will usually be automatic.

Chronic cyanidin-3-glucoside administration improves short-term spatial recognition memory but not passive avoidance learning and memory in streptozotocin-diabetic rats.

PubMed

Nasri, Sima; Roghani, Mehrdad; Baluchnejadmojarad, Tourandokht; Balvardi, Mahboubeh; Rabani, Tahereh

2012-08-01

This research study was conducted to evaluate the efficacy of chronic cyanidin-3-glucoside (C3G) on alleviation of learning and memory deficits in diabetic rats as a result of the observed antidiabetic and antioxidant activity of C3G. Male Wistar rats were divided into control, diabetic, C3G-treated-control and -diabetic groups. The C3G was administered i.p. at a dose of 10 mg/kg on alternate days for eight weeks. For evaluation of learning and memory, initial latency (IL) and step-through latency (STL) were determined at the end of study using passive avoidance test. Meanwhile, spatial recognition memory was assessed as alternation in the Y-maze task. Oxidative stress markers in brain tissue were also measured. It was found that the alternation score of the diabetic rats was lower than that of control (p < 0.01) and C3G-treated diabetic rats showed a higher alternation score as compared to diabetic group (p < 0.05). Diabetic rats also developed a significant impairment in retention and recall in passive avoidance test (p < 0.01) and C3G treatment of diabetic rats did not produce any significant improvement. Meanwhile, increased level of malondialdehyde (MDA) in diabetic rats was significantly reduced following C3G treatment (p < 0.05). Taken together, chronic C3G could improve short-term spatial recognition memory disturbance in the Y-maze test but not retention and recall capability in passive avoidance test in STZ-diabetic rats. Copyright © 2012 John Wiley & Sons, Ltd.

The Effect of BSA-Based Curcumin Nanoparticles on Memory and Hippocampal MMP-2, MMP-9, and MAPKs in Adult Mice.

PubMed

SoukhakLari, Roksana; Moezi, Leila; Pirsalami, Fatema; Moosavi, Maryam

2018-06-24

Although high rate of curcumin consumption has been suggested to decrease the prevalence of Alzheimer's disease (AD), its administration has no effect on the progression of AD in humans and this has been attributed to its poor bioavailability. Using nanotechnology to break down curcumin increases its bioavailability and improves its effect on the brain. BSA, as a non-toxic protein with high binding capacity, was used to break curcumin to nanosize and to explore the effect of nanocurcumin on passive avoidance memory and hippocampal MMP-2 and -9 and MAPKs. BSA-based nanocurcumin was produced by desolvation method. In this study, 15 and 20 mg/kg/p.o. nanocurcumin (based on our preliminary studies) were administered to male NMRI mice weighing 20-25 g for 10 days. Passive avoidance training was performed on day 10 and 24 h after, a retention trial was done. Upon completion of behavioral studies, the hippocampi were isolated and western blot analysis was performed on MMP-2, MMP-9, and MAPKs (JNK, ERK, and p38). The results showed that BSA-based nanocurcumin administered at 15 and 20 mg/kg doses resulted in a significantly improved performance in passive avoidance memory test while its equivalent doses of natural curcumin did not produce a similar effect. In addition, this effect was accompanied with an increase in MMP-2, MMP-9, and p-ERK and a decrease in p-JNK. This study indicates that breaking curcumin to nanosize produces improved effects on passive avoidance memory in adult mice accompanied with MMP-2, MMP-9, p-ERK, and p-JNK changes in the hippocampus.

Participation of muscarinic receptors in memory consolidation in passive avoidance learning.

PubMed

Dobryakova, Yulia V; Gurskaya, Olga; Markevich, Vladimir A

2014-01-01

It is well-known that the cholinergic system and the muscarinic cholinergic receptors are associated with cognitive functions. Here we examined whether a non-selective muscarinic receptor antagonist scopolamine affects learning performance and/or synaptic plasticity during the memory consolidation period. Adult male Wistar rats (250-300 g) were injected with scopolamine (2 mg/kg) or saline immediately after training in a "passive avoidance" task. Memory retention test was conducted 24 h after training. The changes in the latency of the first entry into a dark compartment of a test chamber was chosen as a criterion of learning. The efficacy of synaptic transmission was estimated by the changes in the basal level of focal potentials (fEPSP amplitude and slope ratio) before training (baseline), 90 min after the training (consolidation period), and 24 hour after the training (retention period). We found that foot-shock presentation by itself had no effect on fEPSP within the first 90 min after training, but in 24 hour fEPSPs were decreased. In untrained rats administration of scopolamine had no effect on the fEPSP amplitude within the first 90 min after the injection, but in 24 h we observed an increase in the fEPSP amplitude. In trained animals, scopolamine decreased the fEPSP amplitude in the hippocampal CA1 area during first 1.5 h after the injection. However, the drug had no effect on the memory retention in the passive avoidance task. Taken together our data suggest that scopolamine modifies the synaptic placticity of the hippocampal network but does not induce significant changes in the retention of the passive avoidance skill.

Assessment of the stress transmitted to dental implants connected to screw-retained bars using different casting techniques.

PubMed

Haselhuhn, Klaus; Marotti, Juliana; Tortamano, Pedro; Weiss, Claudia; Suleiman, Lubna; Wolfart, Stefan

2014-12-01

Passive fit of the prosthetic superstructure is important to avoid complications; however, evaluation of passive fit is not possible using conventional procedures. Thus, the aim of this study was to check and locate mechanical stress in bar restorations fabricated using two casting techniques. Fifteen patients received four implants in the interforaminal region of the mandible, and a bar was fabricated using either the cast-on abutment or lost-wax casting technique. The fit accuracy was checked according to the Sheffield's test criteria. Measurements were recorded on the master model with a gap-free, passive fit using foil strain gauges both before and after tightening the prosthetic screws. Data acquisition and processing was analyzed with computer software and submitted to statistical analysis (ANOVA). The greatest axial distortion was at position 42 with the cast-on abutment technique, with a mean distortion of 450 μm/m. The lowest axial distortion occurred at position 44 with the lost-wax casting technique, with a mean distortion of 100 μm/m. The minimal differences between the means of axial distortion do not indicate any significant differences between the techniques (P = 0.2076). Analysis of the sensor axial distortion in relation to the implant position produced a significant difference (P < 0.0001). Significantly higher measurements were recorded in the axial distortion analysis of the distal sensors of implants at the 34 and 44 regions than on the mesial positions at the 32 and 42 regions (P = 0.0481). The measuring technique recorded axial distortion in the implant-supported superstructures. Distortions were present at both casting techniques, with no significant difference between the sides.

Exaggerated acquisition and resistance to extinction of avoidance behavior in treated heroin-dependent men.

PubMed

Sheynin, Jony; Moustafa, Ahmed A; Beck, Kevin D; Servatius, Richard J; Casbolt, Peter A; Haber, Paul; Elsayed, Mahmoud; Hogarth, Lee; Myers, Catherine E

2016-03-01

Addiction is often conceptualized as a behavioral strategy for avoiding negative experiences. In rodents, opioid intake has been associated with abnormal acquisition and extinction of avoidance behavior. Here, we tested the hypothesis that these findings would generalize to human opioid-dependent subjects. Adults meeting DSM-IV criteria for heroin dependence and treated with opioid medication (n = 27) and healthy controls (n = 26) were recruited between March 2013 and October 2013 and given a computer-based task to assess avoidance behavior. For this task, subjects controlled a spaceship and could either gain points by shooting an enemy spaceship or hide in safe areas to avoid on-screen aversive events. Hiding duration during different periods of the task was used to measure avoidance behavior. While groups did not differ on escape responding (hiding) during the aversive event, heroin-dependent men (but not women) made more avoidance responses during a warning signal that predicted the aversive event (analysis of variance, sex × group interaction, P = .007). Heroin-dependent men were also slower to extinguish the avoidance response when the aversive event no longer followed the warning signal (P = .011). This behavioral pattern resulted in reduced opportunity to obtain reward without reducing risk of punishment. Results suggest that, in male patients, differences in avoidance behavior cannot be easily explained by impaired task performance or by exaggerated motor activity. This study provides evidence for abnormal acquisition and extinction of avoidance behavior in opioid-dependent patients. Interestingly, data suggest that abnormal avoidance is demonstrated only by male patients. Findings shed light on cognitive and behavioral manifestations of opioid addiction and may facilitate development of therapeutic approaches to help affected individuals. © Copyright 2016 Physicians Postgraduate Press, Inc.

Comparison of fMRI data from passive listening and active-response story processing tasks in children

PubMed Central

Vannest, Jennifer J.; Karunanayaka, Prasanna R.; Altaye, Mekibib; Schmithorst, Vincent J.; Plante, Elena M.; Eaton, Kenneth J.; Rasmussen, Jerod M.; Holland, Scott K.

2009-01-01

Purpose To use functional MRI methods to visualize a network of auditory and language-processing brain regions associated with processing an aurally-presented story. We compare a passive listening (PL) story paradigm to an active-response (AR) version including on-line performance monitoring and a sparse acquisition technique. Materials/Methods Twenty children (ages 11−13) completed PL and AR story processing tasks. The PL version presented alternating 30-second blocks of stories and tones; the AR version presented story segments, comprehension questions, and 5s tone sequences, with fMRI acquisitions between stimuli. fMRI data was analyzed using a general linear model approach and paired t-test identifying significant group activation. Results Both tasks activated in primary auditory cortex, superior temporal gyrus bilaterally, left inferior frontal gyrus. The AR task demonstrated more extensive activation, including dorsolateral prefrontal cortex and anterior/posterior cingulate cortex. Comparison of effect size in each paradigm showed a larger effect for the AR paradigm in a left inferior frontal ROI. Conclusion Activation patterns for story processing in children are similar in passive listening and active-response tasks. Increases in extent and magnitude of activation in the AR task are likely associated with memory and attention resources engaged across acquisition intervals. PMID:19306445

Intra-Amygdala ZIP Injections Impair the Memory of Learned Active Avoidance Responses and Attenuate Conditioned Taste-Aversion Acquisition in Rats

ERIC Educational Resources Information Center

Gamiz, Fernando; Gallo, Milagros

2011-01-01

We have investigated the effect of protein kinase Mzeta (PKM[zeta]) inhibition in the basolateral amygdala (BLA) upon the retention of a nonspatial learned active avoidance response and conditioned taste-aversion (CTA) acquisition in rats. ZIP (10 nmol/[mu]L) injected into the BLA 24 h after training impaired retention of a learned…

Maternal Modeling and the Acquisition of Fear and Avoidance in Toddlers: Influence of Stimulus Preparedness and Child Temperament

ERIC Educational Resources Information Center

Dubi, Kathrin; Rapee, Ronald M.; Emerton, Jane L.; Schniering, Carolyn A.

2008-01-01

The aim of the present study was to investigate the influence of maternal modeling on the acquisition of fear and avoidance towards fear-relevant and fear-irrelevant, novel stimuli in a sample of 71 toddlers. Children were shown a rubber snake or spider (fear-relevant objects) and a rubber mushroom or flower (fear-irrelevant objects), which were…

The Acquisition of Passives in Serbian

ERIC Educational Resources Information Center

Perovic, Alexandra; Vuksanovic, Jasmina; Petrovic, Boban; Avramovic-Ilic, Irena

2014-01-01

This study examined the comprehension of actional and psychological verbs in both their active and passive (short and long) forms by 99 Serbian-speaking children. The children, whose age ranged between 3 years, 6 months (3;6) and 7 years, 6 months (7;6), were divided into three groups: 3;6-5 ("M" = 4.3), 5;1-6;1 ("M" = 5.6),…

The Effect of Processing Instruction and Dictogloss Tasks on Acquisition of the English Passive Voice

ERIC Educational Resources Information Center

Qin, Jingjing

2008-01-01

This study was intended to compare processing instruction (VanPatten, 1993, 1996, 2000), an input-based focus on form technique, to dictogloss tasks, an output-oriented focus-on-form type of instruction to assess their effects in helping beginning-EFL (English as a Foreign Language) learners acquire the simple English passive voice. Two intact…

Overview of the joint services lightweight standoff chemical agent detector (JSLSCAD)

NASA Astrophysics Data System (ADS)

Hammond, Barney; Popa, Mirela

2005-05-01

This paper presents a system-level description of the Joint Services Lightweight Standoff Chemical Agent Detector (JSLSCAD). JSLSCAD is a passive Fourier Transform InfraRed (FTIR) based remote sensing system for detecting chemical warfare agents. Unlike predecessor systems, JSLSCAD is capable of operating while on the move to accomplish reconnaissance, surveillance, and contamination avoidance missions. Additionally, the system is designed to meet the needs for application on air and sea as well as ground mobile and fixed site platforms. The core of the system is a rugged Michelson interferometer with a flexure spring bearing mechanism and bi-directional data acquisition capability. The sensor is interfaced to a small, high performance spatial scanner that provides high-speed, two-axis area coverage. Command, control, and processing electronics have been coupled with real time control software and robust detection/discrimination algorithms. Operator interfaces include local and remote options in addition to interfaces to external communications networks. The modular system design facilitates interfacing to the many platforms targeted for JSLSCAD.

48 CFR 17.105-2 - Objectives.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Objectives. 17.105-2 Section 17.105-2 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS... contracts. (d) Substantial continuity of production or performance, thus avoiding annual startup costs...

Effect of harmane, an endogenous β-carboline, on learning and memory in rats.

PubMed

Celikyurt, Ipek Komsuoglu; Utkan, Tijen; Gocmez, Semil Selcen; Hudson, Alan; Aricioglu, Feyza

2013-01-01

Our aim was to investigate the effects of acute harmane administration upon learning and memory performance of rats using the three-panel runway paradigm and passive avoidance test. Male rats received harmane (2.5, 5, and 7.5mg/kg, i.p.) or saline 30 min. before each session of experiments. In the three panel runway paradigm, harmane did not affect the number of errors and latency in reference memory. The effect of harmane on the errors of working memory was significantly higher following the doses of 5mg/kg and 7.5mg/kg. The latency was changed significantly at only 7.5mg/kg in comparison to control group. Animals were given pre-training injection of harmane in the passive avoidance test in order to determine the learning function. Harmane treatment decreased the retention latency significantly and dose dependently, which indicates an impairment in learning. In this study, harmane impaired working memory in three panel runway test and learning in passive avoidance test. As an endogenous bioactive molecule, harmane might have a critical role in the modulation of learning and memory functions. Copyright © 2012 Elsevier Inc. All rights reserved.

Input, Triggering and Poverty of the Stimulus in the Second Language Acquisition of Japanese Passives

ERIC Educational Resources Information Center

Hara, Masahiro

2007-01-01

This article adopts an input perspective in examining a poverty-of-the stimulus (POS) learning situation in second language acquisition (SLA). Analysis of grammaticality judgement data from 81 English-speaking and 85 Chinese-speaking learners of Japanese isolates triggering input that informed English learners of subtle semantic properties of the…

English Native Speakers' L2 Acquisition of the Spanish Clitic Se

ERIC Educational Resources Information Center

Bailey, Carolina

2013-01-01

This study investigated the acquisition of the Spanish clitic se by English native speakers in passive, middle, and impersonal constructions. Little research has been done on this topic in SLA within a UG framework (Bayona, 2005; Bruhn de Garavito, 1999). VanPatten (2004) proposed the Processing Instruction (PI) model arguing for the necessity of…

[Interventions on the exposure of non-smoking pregnant women to passive smoking].

PubMed

Yao, Ting-ting; Chen, Xue-yun; Hu, De-wei; Mao, Zheng-zhong

2008-09-01

To investigate the extent of exposure of non-smoking pregnant women to passive smoking; to undertake interventions on the knowledge, attitudes and behaviors of those women toward passive smoking; and to evaluate the effectiveness of the interventions. A total of 128 non-smoking pregnant women participated in the survey. Their knowledge, attitudes and behaviors towards passive smoking were measured by a self-administered questionnaire. A sixteen-week intervention was undertaken. The knowledge and attitudes of the non-smoking pregnant women towards passive smoking improved significantly, as well as their attempts to avoid exposure to the passive smoking brought by their smoking husbands or other family members. Telephone counseling, booklets and doctors' advices were the most acceptable approaches of health education. The comprehensive interventions are effective for improving the knowledge, attitudes and behaviors of non-smoking women toward passive smoking.

Different Role of CA1 5HT3 Serotonin Receptors on Memory Acquisition Deficit Induced by Total (TSD) and REM Sleep Deprivation (RSD).

PubMed

Eydipour, Zainab; Vaezi, Gholamhassan; Nasehi, Mohammad; Haeri-Rouhani, Seyed-Ali; Zarrindast, Mohammad-Reza

2017-09-01

Serotonin receptors such as 5-HT3 plays critical role in regulation of sleep, wake cycle and cognitive process. Thus, we investigated the role of CA1 5HT3 serotonin receptors in memory acquisition deficit induced by total sleep deprivation (TSD; for 24 hour) and REM sleep deprivation (RSD; for 24 hour). Pain perception and locomotor activity were also assessed as factors that may affect the memory process. Modified water box and multi-platform apparatus were used to induce TSD or RSD, respectively. Passive avoidance, hot plate and open field devices were used for assessment of memory acquisition, pain and locomotor activity, respectively. Totally, 152 male Wistar rats were used in the study. Pre-training, intra-CA1 injection of 5-HT3 receptor agonist Chlorophenylbiguanide (Mchl; 0.01 and 0.001 µg/rat; P < 0.001) and antagonist Y-25130 (0.1 µg/rat; P < 0.001) reduced memory acquisition and did not alter pain response, while higher dose of both drugs increased locomotor activity in normal rats. Both TSD and RSD reduced memory acquisition (P < 0.001) and did not alter locomotor activity, while TSD (P < 0.001) but not RSD induced analgesia effect. The amnesia induced by TSD was restored by subthreshold dose of Y25130 (0.001 µg/rat; P < 0.001) but not Mchl (0.0001 µg/rat), while both drugs reversed TSD-induced analgesia effect (P < 0.01 for Mchl and P < 0.05 for Y25130), and Y25130 increased locomotor activity in TSD rats (P < 0.05). In RSD rats, subthreshold dose of both drugs did not alter memory acquisition deficit and increased locomotor activity (P < 0.001 for Mchl and P < 0.01 for Y25130), while the Y25130 (P < 0.001), but not Mchl induced analgesia in the RSD rats. Based on the above data, CA1 5HT3 receptors seem to play a critical role in cognitive and non-cognitive behaviors induced by TSD and RSD.

Behavioral deficits induced by third-trimester equivalent alcohol exposure in male C57BL/6J mice are not associated with reduced adult hippocampal neurogenesis but are still rescued with voluntary exercise.

PubMed

Hamilton, G F; Bucko, P J; Miller, D S; DeAngelis, R S; Krebs, C P; Rhodes, J S

2016-11-01

Prenatal alcohol exposure can produce permanent alterations in brain structure and profound behavioral deficits. Mouse models can help discover mechanisms and identify potentially useful interventions. This study examined long-term influences of either a single or repeated alcohol exposure during the third-trimester equivalent on survival of new neurons in the hippocampus, behavioral performance on the Passive avoidance and Rotarod tasks, and the potential role of exercise as a therapeutic intervention. C57BL/6J male mice received either saline or 5g/kg ethanol split into two s.c. injections, two hours apart, on postnatal day (PD)7 (Experiment 1) or on PD5, 7 and 9 (Experiment 2). All mice were weaned on PD21 and received either a running wheel or remained sedentary from PD35-PD80/81. From PD36-45, mice received i.p. injections of 50mg/kg bromodeoxyuridine (BrdU) to label dividing cells. Behavioral testing occurred between PD72-79. Number of surviving BrdU+ cells and immature neurons (doublecortin; DCX+) was measured at PD80-81. Alcohol did not affect number of BrdU+ or DCX+ cells in either experiment. Running significantly increased number of BrdU+ and DCX+ cells in both treatment groups. Alcohol-induced deficits on Rotarod performance and acquisition of the Passive avoidance task (Day 1) were evident only in Experiment 2 and running rescued these deficits. These data suggest neonatal alcohol exposure does not result in long-term impairments in adult hippocampal neurogenesis in the mouse model. Three doses of ethanol were necessary to induce behavioral deficits. Finally, the mechanisms by which exercise ameliorated the neonatal alcohol induced behavioral deficits remain unknown. Copyright © 2016 Elsevier B.V. All rights reserved.

Venturing out safely: The biogeography of Homo erectus dispersal out of Africa.

PubMed

Carotenuto, F; Tsikaridze, N; Rook, L; Lordkipanidze, D; Longo, Laura; Condemi, Silvana; Raia, P

2016-06-01

The dispersal of Homo erectus out of Africa at some 1.9 million years ago is one of the most important, crucial, and yet controversial events in human evolution. Current opinions about this episode expose the contrast between those who see H. erectus as a highly social, cooperative species seeking out new ecological opportunities to exploit, and those preferring a passive, climate driven explanation for such an event. By using geostatistics techniques and probabilistic models, we characterised the ecological context of H. erectus dispersal, from its East African origin to the colonization of Eurasia, taking into account both the presence of other large mammals and the physical characteristics of the landscape as potential factors. Our model indicated that H. erectus followed almost passively the large herbivore fauna during its dispersal. In Africa, the dispersal was statistically associated with the presence of large freshwater bodies (Rift Valley Lakes). In Eurasia, the presence of H. erectus was associated with the occurrence of geological outcrops likely yielding unconsolidated flint. During the early phase of dispersal, our model indicated that H. erectus actively avoided areas densely populated by large carnivores. This pattern weakened as H. erectus dispersed over Europe, possibly because of the decreasing presence of carnivores there plus the later acquisition of Acheulean technology. During this later phase, H. erectus was associated with limestone and shaley marl, and seems to have been selecting for high-elevation sites. While our results do not directly contradict the idea that H. erectus may have been an active hunter, they clearly point to the fact that predator avoidance may have conditioned its long-distance diffusion as it moved outside Africa. The modelled dispersal route suggests that H. erectus remained preferentially associated with low/middle latitude (i.e., comparatively warm) sites throughout its colonization history. Copyright © 2016 Elsevier Ltd. All rights reserved.

Stages of Drug Use Acquisition among College Students: Implications for the Prevention of Drug Abuse.

ERIC Educational Resources Information Center

Werch, Chudley E.; And Others

1993-01-01

Examined stages of drug use acquisition among college students (n=669) and relationship between stage status and motivation to avoid drugs and frequency of drug use. College students differed with regard to their stage of habit acquisition across five drugs. Findings suggest that acquisition stage heuristic holds promise in increasing…

Whole body heat stress increases motor cortical excitability and skill acquisition in humans

PubMed Central

Littmann, Andrew E.; Shields, Richard K.

2015-01-01

Objective Vigorous systemic exercise stimulates a cascade of molecular and cellular processes that enhance central nervous system (CNS) plasticity and performance. The influence of heat stress on CNS performance and learning is novel. We designed two experiments to determine whether passive heat stress 1) facilitated motor cortex excitability and 2) improved motor task acquisition compared to no heat stress. Methods Motor evoked potentials (MEPs) from the first dorsal interosseus (FDI) were collected before and after 30 minutes of heat stress at 73° C. A second cohort of subjects performed a motor learning task using the FDI either following heat or the no heat condition. Results Heat stress increased heart rate to 65% of age-predicted maximum. After heat, mean resting MEP amplitude increased 48% (P < 0.05). MEP stimulus-response amplitudes did not differ according to stimulus intensity. In the second experiment, heat stress caused a significant decrease in absolute and variable error (p < 0.05) during a novel movement task using the FDI. Conclusions Passive environmental heat stress 1) increases motor cortical excitability, and 2) enhances performance in a motor skill acquisition task. Significance Controlled heat stress may prime the CNS to enhance motor skill acquisition during rehabilitation. PMID:26616546

Antidepressant, psychostimulant, and nootropic effects of major and trace element composition.

PubMed

Afanasieva, O G; Suslov, N I; Shilova, I V

2013-06-01

The antidepressant, psychostimulant, and nootropic effects of a composition of major and trace elements including KCl, RbNO3, magnesium sulfate, and zinc sulfate were studied on the models of behavioural despair (Porsolt test) and conditioned passive avoidance test. The preparation was found to shorten the immobilization time in the Porsolt test and promote retention of the conditioned passive avoidance. The most pronounced psychostimulant effect of the substance was observed at a dose of 4.68 mg/kg and the most pronounced antidepressant effect was found at a dose of 18.72 mg/kg. Maximum nootropic activity of the preparation was found at a dose of 93.6 mg/kg.

[Interaction of immobilization stress and food-getting learning].

PubMed

Levshina, I P; Stashkevich, I S; Shuĭkin, N N

2009-01-01

The behavioral effects of emotional negative stress (immobilization) were studied in Wistar rats intact and those that had previous positive emotion experience. The food-getting learning has been chosen as positive emotion experience. Animals were trained in food pellet-reaching task by their preferred paw. It was shown that immobilization of intact rats leads to suppression of motor activity and increasing the duration of grooming. These effects indicate enhancement of passive-avoidance reactions. It was also shown that motor learning in group of rats with food reinforcement before immobilisation significantly reduces appearance of passive-avoidance reactions. It was found that immobilization stress does not inverse the initial direction of limb preference in majority of rats.

Transformational leadership in primary care: Clinicians' patterned approaches to care predict patient satisfaction and health expectations.

PubMed

Huynh, Ho Phi; Sweeny, Kate; Miller, Tricia

2018-04-01

Clinicians face the complex challenge of motivating their patients to achieve optimal health while also ensuring their satisfaction. Inspired by transformational leadership theory, we proposed that clinicians' motivational behaviors can be organized into three patient care styles (transformational, transactional, and passive-avoidant) and that these styles differentially predict patient health outcomes. In two studies using patient-reported data and observer ratings, we found that transformational patient care style positively predicted patients' satisfaction and health expectations above and beyond transactional and passive-avoidant patient care style. These findings provide initial support for the patient care style approach and suggest novel directions for the study of clinicians' motivational behaviors.

Comparison between implant-supported prostheses and teeth regarding passive threshold level.

PubMed

Jacobs, R; van Steenberghe, D

1993-01-01

A passive threshold determination was carried out on 31 patients subdivided into four test groups according to different prosthesis types supported by osseointegrated implants. They were compared to a control group of 10 patients with nonrestored natural test teeth. Forces were generated by a solenoid-driven stimulating device, which was placed in contact with the implant or tooth prior to the actual force rise to avoid impact forces. The findings indicate that the threshold level of implants is 50 times higher than that of natural teeth when tapping is avoided, which might otherwise trigger distant receptors. Bone deformation triggering the periosteal mechanoreceptors is the most logical explanation for the sensation reported.

Identifying the Factors That Facilitate or Hinder Advance Planning by Persons With Dementia

PubMed Central

Hirschman, Karen B.; Kapo, Jennifer M.; Karlawish, Jason H. T.

2009-01-01

We performed semistructured interviews with 30 family members of patients with advanced dementia to identify the factors that facilitate or hinder advance planning by persons with dementia. All interviews were analyzed using qualitative data analysis techniques. The majority (77%) of family members reported that their relative had some form of written advance directive, and at least half reported previous discussions about health care preferences (57%), living situation or placement issues (50%), and finances or estate planning (60%) with the patient. Family members reported some themes that prompted planning and others that were barriers to planning. Events that most often triggered planning were medical, living situation, or financial issues associated with a friend or family member of the patient (57%). Barriers to planning included both passive and active avoidance. The most common form of passive avoidance was not realizing the importance of planning until it was too late to have the discussion (63%). The most common form of active avoidance was avoiding the discussion (53%). These data suggest potentially remediable strategies to address barriers to advance planning discussions. PMID:18580595

Asymmetric band offsets in silicon heterojunction solar cells: Impact on device performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seif, Johannes Peter; Menda, Deneb; Descoeudres, Antoine

Here, amorphous/crystalline silicon interfaces feature considerably larger valence than conduction band offsets. In this article, we analyze the impact of such band offset asymmetry on the performance of silicon heterojunction solar cells. To this end, we use silicon suboxides as passivation layers -- inserted between substrate and (front or rear) contacts -- since such layers enable intentionally exacerbated band-offset asymmetry. Investigating all topologically possible passivation layer permutations and focussing on light and dark current-voltage characteristics, we confirm that to avoid fill factor losses, wider-bandgap silicon oxide films (of at least several nanometer thin) should be avoided in hole-collecting contacts. Asmore » a consequence, device implementation of such films as window layers -- without degraded carrier collection -- demands electron collection at the front and hole collection at the rear. Furthermore, at elevated operating temperatures, once possible carrier transport barriers are overcome by thermionic (field) emission, the device performance is mainly dictated by the passivation of its surfaces. In this context, compared to the standard amorphous silicon layers, the wide-bandgap oxide layers applied here passivate remarkably better at these temperatures, which may represent an additional benefit under practical operation conditions.« less

Asymmetric band offsets in silicon heterojunction solar cells: Impact on device performance

DOE PAGES

Seif, Johannes Peter; Menda, Deneb; Descoeudres, Antoine; ...

2016-08-01

Here, amorphous/crystalline silicon interfaces feature considerably larger valence than conduction band offsets. In this article, we analyze the impact of such band offset asymmetry on the performance of silicon heterojunction solar cells. To this end, we use silicon suboxides as passivation layers -- inserted between substrate and (front or rear) contacts -- since such layers enable intentionally exacerbated band-offset asymmetry. Investigating all topologically possible passivation layer permutations and focussing on light and dark current-voltage characteristics, we confirm that to avoid fill factor losses, wider-bandgap silicon oxide films (of at least several nanometer thin) should be avoided in hole-collecting contacts. Asmore » a consequence, device implementation of such films as window layers -- without degraded carrier collection -- demands electron collection at the front and hole collection at the rear. Furthermore, at elevated operating temperatures, once possible carrier transport barriers are overcome by thermionic (field) emission, the device performance is mainly dictated by the passivation of its surfaces. In this context, compared to the standard amorphous silicon layers, the wide-bandgap oxide layers applied here passivate remarkably better at these temperatures, which may represent an additional benefit under practical operation conditions.« less

Asymmetric band offsets in silicon heterojunction solar cells: Impact on device performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seif, Johannes Peter, E-mail: johannes.seif@alumni.epfl.ch; Ballif, Christophe; De Wolf, Stefaan

Amorphous/crystalline silicon interfaces feature considerably larger valence than conduction band offsets. In this article, we analyze the impact of such band offset asymmetry on the performance of silicon heterojunction solar cells. To this end, we use silicon suboxides as passivation layers—inserted between substrate and (front or rear) contacts—since such layers enable intentionally exacerbated band-offset asymmetry. Investigating all topologically possible passivation layer permutations and focussing on light and dark current-voltage characteristics, we confirm that to avoid fill factor losses, wider-bandgap silicon oxide films (of at least several nanometer thin) should be avoided in hole-collecting contacts. As a consequence, device implementation ofmore » such films as window layers—without degraded carrier collection—demands electron collection at the front and hole collection at the rear. Furthermore, at elevated operating temperatures, once possible carrier transport barriers are overcome by thermionic (field) emission, the device performance is mainly dictated by the passivation of its surfaces. In this context, compared to the standard amorphous silicon layers, the wide-bandgap oxide layers applied here passivate remarkably better at these temperatures, which may represent an additional benefit under practical operation conditions.« less

Passive imaging based multi-cue hazard detection spacecraft safe landing

NASA Technical Reports Server (NTRS)

Huertas, Andres; Cheng, Yang; Madison, Richard

2006-01-01

Accurate assessment of potentially damaging ground hazards during the spacecraft EDL (Entry, Descent and Landing) phase is crucial to insure a high probability of safe landing. A lander that encounters a large rock, falls off a cliff, or tips over on a steep slope can sustain mission ending damage. Guided entry is expected to shrink landing ellipses from 100-300 km to -10 km radius for the second generation landers as early as 2009. Regardless of size and location, however, landing ellipses will almost always contain hazards such as craters, discontinuities, steep slopes, and large rocks. It is estimated that an MSL (Mars Science Laboratory)-sized lander should detect and avoid 16- 150m diameter craters, vertical drops similar to the edges of 16m or 3.75m diameter crater, for high and low altitude HAD (Hazard Detection and Avoidance) respectively. It should also be able to detect slopes 20' or steeper, and rocks 0.75m or taller. In this paper we will present a passive imaging based, multi-cue hazard detection and avoidance (HDA) system suitable for Martian and other lander missions. This is the first passively imaged HDA system that seamlessly integrates multiple algorithm-crater detection, slope estimation, rock detection and texture analysis, and multicues- crater morphology, rock distribution, to detect these hazards in real time.

Central ghrelin increases anxiety in the Open Field test and impairs retention memory in a passive avoidance task in neonatal chicks.

PubMed

Carvajal, Pedro; Carlini, Valeria P; Schiöth, Helgi B; de Barioglio, Susana R; Salvatierra, Nancy A

2009-05-01

Ghrelin (Grh) is an endogenous ligand for the growth hormone secretagogue receptor. Although Ghr stimulates feeding in rats, it inhibits feeding in neonatal chicks. However, little is known about other central behavioral effects of Ghr. Therefore, we investigated the Ghr effects, injected intracerebroventricularly, on anxiety and memory retention of neonatal chicks in an Open Field test and in a one-trial passive avoidance task, respectively. In the Open Field test, the administration of Ghr in a dose-dependent manner increased the latency to ambulate but decreased ambulation activity, indicating an anxiogenic effect. Furthermore, chicks trained on a passive avoidance task and injected with a dose of 30pmol of Ghr immediately after training showed an impairment of memory retention. However, there were no significant effects on the number of pecks during the pretraining, training, retention and discrimination. In addition, different doses of Ghr produced an inhibition in food intake at different times after injection. Our results indicate that Ghr induces anxiogenesis in chicks. Moreover, we have shown for the first time that Ghr can decrease memory retention in a non-mammalian species, suggesting that Ghr may play an important role in the processes of memory retention in birds.

Effects of URB597 as an inhibitor of fatty acid amide hydrolase on WIN55, 212-2-induced learning and memory deficits in rats.

PubMed

Hasanein, Parisa; Teimuri Far, Massoud

2015-04-01

Cannabinoid and endocannabinoid systems have been implicated in several physiological functions including modulation of cognition. In this study we evaluated the effects and interaction between fatty-acid amide hydrolase (FAAH) inhibitor URB597 and CB1 receptor agonist WIN55, 212-2 on memory using object recognition and passive avoidance learning (PAL) tests. Learning and memory impairment was induced by WIN 55, 212-2 administration (1mg/kg, i.p.) 30min before the acquisition trial. URB597 (0.1, 0.3 and 1mg/kg, i.p.) or SR141716A (1mg/kg, i.p.) was injected to rats 10min before WIN 55, 212-2 or URB597 respectively. URB597 (0.3 and 1mg/kg) but not 0.1mg/kg induced higher discrimination index (DI) in object recognition test and enhanced memory acquisition in PAL test. The cognitive enhancing effect of URB597 was blocked by a CB1 receptor antagonist, SR141716A which at this dose alone had no effect on cognition. WIN55, 212-2 caused cognition deficits in both tests. URB597 (0.3 and 1mg/kg) treatment could alleviate the negative influence of WIN 55, 212-2 on cognition and memory. These results indicate URB597 potential to protect against memory deficits induced by cannabinoid. Therefore, in combination with URB597 beneficial effects, this study suggests that URB597 has recognition and acquisition memory enhancing effects. It may also constitute a novel approach for the treatment of cannabinoid induced memory deficits and lead to a better understanding of the brain mechanisms underlying cognition. Copyright © 2015 Elsevier Inc. All rights reserved.

Lessons Learned.

ERIC Educational Resources Information Center

Hassell, Kim Dale

2000-01-01

Discusses the common mistakes in school design and construction and how to avoid them. Mistake avoidance in mastering planning, site acquisition, drawing changes, budgeting, school design process, construction management, and the architect's role are highlighted. (GR)

31 CFR 800.104 - Transactions or devices for avoidance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (Continued) OFFICE OF INVESTMENT SECURITY, DEPARTMENT OF THE TREASURY REGULATIONS PERTAINING TO MERGERS, ACQUISITIONS, AND TAKEOVERS BY FOREIGN PERSONS General § 800.104 Transactions or devices for avoidance. Any...

Activation of β-adrenoceptor facilitates active avoidance learning through enhancement of glutamate levels in the hippocampal dentate gyrus.

PubMed

Lv, Jing; Feng, Hao; Chen, Ling; Wang, Wei-Yao; Yue, Xue-Ling; Jin, Qing-Hua

2017-10-18

Long-term potentiation (LTP) is widely accepted as the best studied model for neurophysiological mechanisms that could underlie learning and memory formation. Despite a number of studies indicating that β-adrenoceptors in the hippocampal dentate gyrus (DG) is involved in the modulation of learning and memory as well as LTP, few studies have used glutamate release as a visual indicator in awake animals to explore the role of β-adrenoceptors in learning-dependent LTP. Therefore, in the present study, the effects of propranolol (an antagonist of β-adrenoceptor) and isoproterenol (an agonist of β-adrenoceptor) on extracellular concentrations of glutamate and amplitudes of field excitatory postsynaptic potential were measured in the DG region during active avoidance learning in freely moving conscious rats. In the control group, the glutamate level in the DG was significantly increased during the acquisition of active avoidance behavior and returned to basal level following extinction training. In propranolol group, antagonism of β-adrenoceptors in the DG significantly reduced the change in glutamate level, and the acquisition of the active avoidance behavior was significantly inhibited. In contrast, the change in glutamate level was significantly enhanced by isoproterenol, and the acquisition of the active avoidance behavior was significantly accelerated. Furthermore, in all groups, the changes in glutamate level were accompanied by corresponding changes in field excitatory postsynaptic potential amplitude and active avoidance behavior. Our results suggest that activation of β-adrenoceptors in the hippocampal DG facilitates active avoidance learning by modulations of glutamate level and synaptic efficiency in rats.

Sense and avoid technology for Global Hawk and Predator UAVs

NASA Astrophysics Data System (ADS)

McCalmont, John F.; Utt, James; Deschenes, Michael; Taylor, Michael J.

2005-05-01

The Sensors Directorate at the Air Force Research Laboratory (AFRL) along with Defense Research Associates, Inc. (DRA) conducted a flight demonstration of technology that could potentially satisfy the Federal Aviation Administration's (FAA) requirement for Unmanned Aerial Vehicles (UAVs) to sense and avoid local air traffic sufficient to provide an "...equivalent level of safety, comparable to see-and-avoid requirements for manned aircraft". This FAA requirement must be satisfied for autonomous UAV operation within the national airspace. The real-time on-board system passively detects approaching aircraft, both cooperative and non-cooperative, using imaging sensors operating in the visible/near infrared band and a passive moving target indicator algorithm. Detection range requirements for RQ-4 and MQ-9 UAVs were determined based on analysis of flight geometries, avoidance maneuver timelines, system latencies and human pilot performance. Flight data and UAV operating parameters were provided by the system program offices, prime contractors, and flight-test personnel. Flight demonstrations were conducted using a surrogate UAV (Aero Commander) and an intruder aircraft (Beech Bonanza). The system demonstrated target detection ranges out to 3 nautical miles in nose-to-nose scenarios and marginal visual meteorological conditions. (VMC) This paper will describe the sense and avoid requirements definition process and the system concept (sensors, algorithms, processor, and flight rest results) that has demonstrated the potential to satisfy the FAA sense and avoid requirements.

Molecular Monolayers for Electrical Passivation and Functionalization of Silicon-Based Solar Energy Devices.

PubMed

Veerbeek, Janneke; Firet, Nienke J; Vijselaar, Wouter; Elbersen, Rick; Gardeniers, Han; Huskens, Jurriaan

2017-01-11

Silicon-based solar fuel devices require passivation for optimal performance yet at the same time need functionalization with (photo)catalysts for efficient solar fuel production. Here, we use molecular monolayers to enable electrical passivation and simultaneous functionalization of silicon-based solar cells. Organic monolayers were coupled to silicon surfaces by hydrosilylation in order to avoid an insulating silicon oxide layer at the surface. Monolayers of 1-tetradecyne were shown to passivate silicon micropillar-based solar cells with radial junctions, by which the efficiency increased from 8.7% to 9.9% for n + /p junctions and from 7.8% to 8.8% for p + /n junctions. This electrical passivation of the surface, most likely by removal of dangling bonds, is reflected in a higher shunt resistance in the J-V measurements. Monolayers of 1,8-nonadiyne were still reactive for click chemistry with a model catalyst, thus enabling simultaneous passivation and future catalyst coupling.

S-wave velocity measurements along levees in New Orleans using passive surface wave methods

NASA Astrophysics Data System (ADS)

Hayashi, K.; Lorenzo, J. M.; Craig, M. S.; Gostic, A.

2017-12-01

In order to develop non-invasive methods for levee inspection, geophysical investigations were carried out at four sites along levees in the New Orleans area: 17th Street Canal, London Avenue Canal, Marrero Levee, and Industrial Canal. Three of the four sites sustained damage from Hurricane Katrina in 2005 and have since been rebuilt. The geophysical methods used include active and passive surface wave methods, and capacitively coupled resistivity. This paper summarizes the acquisition and analysis of the 1D and 2D passive surface wave data. Twelve wireless seismic data acquisition units with 2 Hz vertical component geophones were used to record data. Each unit includes a GPS receiver so that all units can be synchronized over any distance without cables. The 1D passive method used L shaped arrays of three different sizes with geophone spacing ranging from 5 to 340 m. Ten minutes to one hour of ambient noise was recorded with each array, and total data acquisition took approximately two hours at each site. The 2D method used a linear array with a geophone spacing of 5m. Four geophones were moved forward every 10 minutes along 400 1000 m length lines. Data acquisition took several hours for each line. Recorded ambient noise was processed using the spatial autocorrelation method and clear dispersion curves were obtained at all sites (Figure 1a). Minimum frequencies ranged from 0.4 to 0.7 Hz and maximum frequencies ranged from 10 to 30 Hz depending on the site. Non-linear inversion was performed and 1D and 2D S-wave velocity models were obtained. The 1D method penetrated to depths ranging from 200 to 500 m depending on the site (Figure 1b). The 2D method penetrated to a depth of 40 60 m and provided 400 1000 m cross sections along the levees (Figure 2). The interpretation focused on identifying zones beneath the levees or canal walls having low S-wave velocities corresponding to saturated, unconsolidated sands, or low-rigidity clays. Resultant S-wave velocity profiles are generally consistent with existing drilling logs and the results of laboratory tests.

Effect of noopept and afobazole on the development of neurosis of learned helplessness in rats.

PubMed

Uyanaev, A A; Fisenko, V P; Khitrov, N K

2003-08-01

We studied the effects of new psychotropic preparations noopept and afobazole on acquisition of the conditioned active avoidance response and development of neurosis of learned helplessness in rats. Noopept in doses of 0.05-0.10 mg/kg accelerated acquisition of conditioned active avoidance response and reduced the incidence of learned helplessness in rats. Afobazole in a dose of 5 mg/kg produced an opposite effect, which is probably related to high selective anxiolytic activity of this preparation.

Passive Collision Avoidance System for UAS

DTIC Science & Technology

2008-09-01

feasibility of using SWAP efficient LWIR microbolometers as outlined in the Priest report circa 1998 as a solution to the collision avoidance problems for UASs...81 7.3 LWIR Multispectral Sensor ..........................................................................................84 7.4 LWIR ... LWIR image of the Ultralight. Muffler runs at approximately 1200 F. ......................32 Figure 36: 3D model of LVDS circuit board with L-3

Chronic treatment with the new anticonvulsant drug lacosamide impairs learning and memory processes in rats: A possible role of BDNF/TrkB ligand receptor system.

PubMed

Shishmanova-Doseva, Michaela; Peychev, Lyudmil; Koeva, Yvetta; Terzieva, Dora; Georgieva, Katerina; Peychev, Zhivko

2018-06-01

Cognitive impairment is considered a frequent side effect in the drug treatment of epilepsy. The objective of the present study was to investigate the effects of lacosamide (LCM) on learning and memory processes in rats, on the serum level of brain-derived neurotrophic factor (BDNF) and BDNF/TrkB ligand receptor system expression in the hippocampal formation. Male Wistar rats underwent long-term treatment with three different doses of lacosamide - 3 mg/kg (LCM 3), 10 mg/kg (LCM 10) and 30 mg/kg (LCM 30). All rats were subjected to one active and one passive avoidance tests. The BDNF/TrkB immunohistochemical expression in the hippocampus was measured and serum BDNF was determined. The LCM-treated rats made fewer avoidance responses than controls during acquisition training and in the memory retention test. The number of escapes in the LCM 10 and LCM 30 groups decreased throughout the test, while the rats in the LCM 3 group showed fewer escapes only in the memory test in the active avoidance task. In the step-down test, the latency time of the LCM-30 treated rats was reduced as compared with the controls during the learning session and the short- and long-term memory retention tests. Lacosamide induced a dose-dependent reduction of the hippocampal expression of BDNF and its receptor TrkB. We found no significant difference between BDNF serum levels in the test animals and controls. The results of the study suggest that LCM suppresses the learning and memory processes in rats, with the inhibition of hippocampal BDNF/TrkB ligand receptor system being one of the possible mechanisms causing this effect. Copyright © 2018 Elsevier Inc. All rights reserved.

Whole body heat stress increases motor cortical excitability and skill acquisition in humans.

PubMed

Littmann, Andrew E; Shields, Richard K

2016-02-01

Vigorous systemic exercise stimulates a cascade of molecular and cellular processes that enhance central nervous system (CNS) plasticity and performance. The influence of heat stress on CNS performance and learning is novel. We designed two experiments to determine whether passive heat stress (1) facilitated motor cortex excitability and (2) improved motor task acquisition compared to no heat stress. Motor evoked potentials (MEPs) from the first dorsal interosseus (FDI) were collected before and after 30 min of heat stress at 73 °C. A second cohort of subjects performed a motor learning task using the FDI either following heat or the no heat condition. Heat stress increased heart rate to 65% of age-predicted maximum. After heat, mean resting MEP amplitude increased 48% (p<0.05). MEP stimulus-response amplitudes did not differ according to stimulus intensity. In the second experiment, heat stress caused a significant decrease in absolute and variable error (p<0.05) during a novel movement task using the FDI. Passive environmental heat stress (1) increases motor cortical excitability, and (2) enhances performance in a motor skill acquisition task. Controlled heat stress may prime the CNS to enhance motor skill acquisition during rehabilitation. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Increased levels of conditioned fear and avoidance behavior coincide with changes in phosphorylation of the protein kinase B (AKT) within the amygdala in a mouse model of extremes in trait anxiety.

PubMed

Yen, Yi-Chun; Mauch, Christoph P; Dahlhoff, Maik; Micale, Vincenzo; Bunck, Mirjam; Sartori, Simone B; Singewald, Nicolas; Landgraf, Rainer; Wotjak, Carsten T

2012-07-01

Patients diagnosed for anxiety disorders often display faster acquisition and slower extinction of learned fear. To gain further insights into the mechanisms underlying these phenomenona, we studied conditioned fear in mice originating form a bi-directional selective breeding approach, which is based on elevated plus-maze behavior and results in CD1-derived high (HAB), normal (NAB), and low (LAB) anxiety-related behavior mice. HAB mice displayed pronounced cued-conditioned fear compared to NAB/CD1 and LAB mice that coincided with increased phosphorylation of the protein kinase B (AKT) in the basolateral amygdala 45 min after conditioning. No similar changes were observed after non-associative immediate shock presentations. Fear extinction of recent but not older fear memories was preserved. However, HAB mice were more prone to relapse of conditioned fear with the passage of time. HAB mice also displayed higher levels of contextual fear compared to NAB and LAB mice and exaggerated avoidance following step-down avoidance training. Interestingly, HAB mice showed lower and LAB mice higher levels of acoustic startle responses compared to NAB controls. The increase in arousal observed in LAB mice coincided with the general absence of conditioned freezing. Taken together, our results suggest that the genetic predisposition to high anxiety-related behavior may increase the risk of forming traumatic memories, phobic-like fear and avoidance behavior following aversive encounters, with a clear bias towards passive coping styles. In contrast, genetic predisposition to low anxiety-related and high risk-taking behavior seems to be associated with an increase in active coping styles. Our data imply changes in AKT phosphorylation as a therapeutic target for the prevention of exaggerated fear memories. Copyright © 2012 Elsevier Inc. All rights reserved.

26 CFR 1.267(f)-1 - Controlled groups.

Code of Federal Regulations, 2010 CFR

2010-04-01

... § 1.1502-13. See also, sections 269 (acquisitions to evade or avoid income tax) and 482 (allocations... is engaged in or structured with a principal purpose to avoid the purposes of this section (including, for example, by avoiding treatment as an intercompany sale or by distorting the timing of losses or...

Applying Movement Ecology to Marine Animals with Complex Life Cycles.

PubMed

Allen, Richard M; Metaxas, Anna; Snelgrove, Paul V R

2018-01-03

Marine animals with complex life cycles may move passively or actively for fertilization, dispersal, predator avoidance, resource acquisition, and migration, and over scales from micrometers to thousands of kilometers. This diversity has catalyzed idiosyncratic and unfocused research, creating unsound paradigms regarding the role of movement in ecology and evolution. The emerging movement ecology paradigm offers a framework to consolidate movement research independent of taxon, life-history stage, scale, or discipline. This review applies the framework to movement among life-history stages in marine animals with complex life cycles to consolidate marine movement research and offer insights for scientists working in aquatic and terrestrial realms. Irrespective of data collection or simulation strategy, breaking each life-history stage down into the fundamental units of movement allows each unit to be studied independently or interactively with other units. Understanding these underlying mechanisms of movement within each life-history stage can then be used to construct lifetime movement paths. These paths can allow further investigation of the relative contributions and interdependencies of steps and phases across a lifetime and how these paths influence larger research topics, such as population-level movements.

Interactions between oxiracetam, aniracetam and scopolamine on behavior and brain acetylcholine.

PubMed

Spignoli, G; Pepeu, G

1987-07-01

The effect of cognition-enhancing agents oxiracetam and aniracetam on scopolamine-induced amnesia and brain acetylcholine decrease was investigated in the rat. Acetylcholine levels were measured by means of a gas-chromatographic method. Scopolamine (0.63 mg/kg IP 60 min before training) prevented the acquisition of a passive avoidance conditioned response ("step through": retest 30 min after training) and brought about a 64, 56 and 42% decrease in acetylcholine level in the cortex, hippocampus and striatum respectively. Oxiracetam (50 and 100 mg/kg IP) administered 30 min before scopolamine reduced the scopolamine-induced amnesic effect and decrease in acetylcholine level in the cortex and hippocampus, but not in the striatum. Lower and higher doses of oxiracetam were ineffective. Aniracetam (100 mg/kg PO) also prevented scopolamine-induced amnesia but attenuated acetylcholine decrease in the hippocampus only. Aniracetam (300 mg PO) reduced acetylcholine decrease in the hippocampus but did not prevent scopolamine-amnesia. In conclusion, oxiracetam and aniracetam exert a stimulatory effect on specific central cholinergic pathways. However, a direct relationship between cognition-enhancing properties and cholinergic activation needs further confirmation.

Applying Movement Ecology to Marine Animals with Complex Life Cycles

NASA Astrophysics Data System (ADS)

Allen, Richard M.; Metaxas, Anna; Snelgrove, Paul V. R.

2018-01-01

Marine animals with complex life cycles may move passively or actively for fertilization, dispersal, predator avoidance, resource acquisition, and migration, and over scales from micrometers to thousands of kilometers. This diversity has catalyzed idiosyncratic and unfocused research, creating unsound paradigms regarding the role of movement in ecology and evolution. The emerging movement ecology paradigm offers a framework to consolidate movement research independent of taxon, life-history stage, scale, or discipline. This review applies the framework to movement among life-history stages in marine animals with complex life cycles to consolidate marine movement research and offer insights for scientists working in aquatic and terrestrial realms. Irrespective of data collection or simulation strategy, breaking each life-history stage down into the fundamental units of movement allows each unit to be studied independently or interactively with other units. Understanding these underlying mechanisms of movement within each life-history stage can then be used to construct lifetime movement paths. These paths can allow further investigation of the relative contributions and interdependencies of steps and phases across a lifetime and how these paths influence larger research topics, such as population-level movements.

Contrasting effects of acute and chronic treatment with imipramine and fluoxetine on inhibitory avoidance and escape responses in mice exposed to the elevated T-maze.

PubMed

Gomes, Karina Santos; de Carvalho-Netto, Eduardo Ferreira; Monte, Kátia Cristina Da Silva; Acco, Bruno; Nogueira, Paulo José de Campos; Nunes-de-Souza, Ricardo Luiz

2009-03-30

The elevated T-maze (ETM) is an animal model of anxiety-like behavior that assesses two different defensive behavioral tasks in the same animal-acquisition of inhibitory avoidance and latency to escape from an open and elevated arm. In rats, cute and chronic treatments with anxiolytic-like drugs impair avoidance acquisition while only chronic administration of panicolytic-like drugs impairs open arm withdrawal. To date, only the acute effects of anxiolytic/anxiogenic or panicolytic/panicogenic drugs have been tested in the mouse ETM and the results have partially corroborated those found in the rat ETM. This study investigated the effects of acute (a single intraperitoneal injection 30 min before testing) and chronic (daily i.p. injections for 15 consecutive days) treatment with imipramine or fluoxetine, non-selective and selective serotonin reuptake inhibitors, respectively, on inhibitory avoidance and escape tasks in the mouse ETM. Neither acute nor chronic treatment with imipramine (0, 1, 5 or 10 mg/kg, i.p.) significantly changed the behavioral profile of mice in the two ETM tasks. Interestingly, while acute fluoxetine (0, 5, 10, 20 or 40 mg/kg, i.p.) facilitated inhibitory avoidance and impaired escape latency, chronic treatment (0, 5, 20 or 40 mg/kg, i.p.) with this selective serotonin reuptake inhibitor (SSRI) produced an opposite effect, i.e., it impaired inhibitory avoidance acquisition and facilitated open arm withdrawal. Importantly, acute or chronic treatment with imipramine (except at the highest dose that increased locomotion when given acutely) or fluoxetine failed to alter general locomotor activity in mice as assessed in an ETM in which all arms were enclosed by lateral walls (eETM). These results suggest that inhibitory avoidance acquisition is a useful task for the evaluation of acute and chronic effects of SSRI treatment on anxiety in mice. However, as open arm latency was actually increased and reduced by acute and chronic fluoxetine, respectively, this does not seem to be a useful measure of escape from a proximal threat in this species.

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

PubMed

Kim, Jong Min; Kim, Dong Hyun; Park, Se Jin; Park, Dong Hyun; Jung, Seo Yun; Kim, Hyoung Ja; Lee, Yong Sup; Jin, Changbae; Ryu, Jong Hoon

2010-08-16

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. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Preventive effects of Salvia officinalis L. against learning and memory deficit induced by diabetes in rats: Possible hypoglycaemic and antioxidant mechanisms.

PubMed

Hasanein, Parisa; Felehgari, Zhila; Emamjomeh, Abbasali

2016-05-27

Learning and memory impairment occurs in diabetes. Salvia officinalis L. (SO) has been used in Iranian traditional medicine as a remedy against diabetes. We hypothesized that chronic administration of SO (400, 600 and 800mg/kg, p.o.) and its principal constituent, rosmarinic acid, would affect on passive avoidance learning (PAL) and memory in streptozocin-induced diabetic and non-diabetic rats. We also explored hypoglycemic and antioxidant activities of SO as the possible mechanisms. Treatments were begun at the onset of hyperglycemia. PAL was assessed 30days later. Retention test was done 24h after training. At the end, animals were weighed and blood samples were drawn for further analyzing of glucose and oxidant/antioxidant markers. Diabetes induced deficits in acquisition and retrieval processes. SO (600 and 800mg/kg) and rosmarinic acid reversed learning and memory deficits induced by diabetes and improved cognition of healthy rats. While the dose of 400mg/kg had no effect, the higher doses and rosmarinic acid inhibited hyperglycemia and lipid peroxidation as well as enhanced the activity of antioxidant enzymes superoxide dismutase and catalase. SO prevented diabetes-induced acquisition and memory deficits through inhibiting hyperglycemia, lipid peroxidation as well as enhancing antioxidant defense systems. Therefore, SO and its principal constituent rosmarinic acid represent a potential therapeutic option against diabetic memory impairment which deserves consideration and further examination. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Development of EOS-aided procedures for the determination of the water balance of hydrologic budget of a large watershed

NASA Technical Reports Server (NTRS)

Congalton, Russell G.; Thomas, Randall W.; Zinke, Paul J.

1986-01-01

Work focused on the acquisition of remotely sensed data for the 1985 to 1986 hydrogolic year; continuation of the field measurement program; continued acquisition and construction of passive microwave remote sensing instruments; a compilation of data necessary for an initial water balance computation; and participation with the EOS Simulataneity Team in reviewing the Feather River watershed as a possible site for a simultaneity experiment.

Genotype-environment interaction in passive avoidance learning of the paradise fish (Macropodus opercularis).

PubMed

Csányi, V; Gervai, J

1985-01-01

Passive dark avoidance conditioning and effects of the presence and absence of a fish-like dummy on the training process were studied in four inbred strains of paradise fish. Strain differences were found in the shuttle activity during habituation trials, and in the sensitivity to the mild electric shock punishment. The presence or absence of the dummy in the punished dark side of the shuttle box had a genotype-dependent effect on the measures taken during the conditioning process. The statistical analysis of the learning curves revealed differences in the way the strains varied in the different environments, i.e. genotype--environment interaction components of variances were identified. The results are discussed in the light of previous investigations and their implication in further genetic analysis.

CRISPR adaptation biases explain preference for acquisition of foreign DNA

PubMed Central

Yosef, Ido; Auster, Oren; Manor, Miriam; Amitai, Gil; Edgar, Rotem; Qimron, Udi; Sorek, Rotem

2015-01-01

In the process of CRISPR adaptation, short pieces of DNA (“spacers”) are acquired from foreign elements and integrated into the CRISPR array. It so far remained a mystery how spacers are preferentially acquired from the foreign DNA while the self chromosome is avoided. Here we show that spacer acquisition is replication-dependent, and that DNA breaks formed at stalled replication forks promote spacer acquisition. Chromosomal hotspots of spacer acquisition were confined by Chi sites, which are sequence octamers highly enriched on the bacterial chromosome, suggesting that these sites limit spacer acquisition from self DNA. We further show that the avoidance of “self” is mediated by the RecBCD dsDNA break repair complex. Our results suggest that in E. coli, acquisition of new spacers depends on RecBCD-mediated processing of dsDNA breaks occurring primarily at replication forks, and that the preference for foreign DNA is achieved through the higher density of Chi sites on the self chromosome, in combination with the higher number of forks on the foreign DNA. This model explains the strong preference to acquire spacers from both high copy plasmids and phages. PMID:25874675

Simultaneous passively Q-switched dual-wavelength solid-state laser working at 1065 and 1066 nm.

PubMed

Pallas, Florent; Herault, Emilie; Roux, Jean-Francois; Kevorkian, Antoine; Coutaz, Jean-Louis; Vitrant, Guy

2012-07-15

A passively Q-switched dual-wavelength solid-state laser is presented. The two wavelengths are emitted by two different crystals in order to avoid gain competition, and the synchronization between the pulses is obtained by external triggering of the saturable absorber. Sum frequency mixing is demonstrated, proving the interest of this source for terahertz generation in the 0.3-0.4 THz range through difference frequency generation.

76 FR 58142 - Defense Federal Acquisition Regulation Supplement; Passive Radio Frequency Identification (DFARS...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-20

.... (6) Agricultural products such as seeds, grains, or animal feed. Case means either a MIL-STD-129... pharmaceuticals, biologicals, and reagents--suppliers should limit the mixing of excluded and non-excluded...

Somatosensory Contribution to the Initial Stages of Human Motor Learning

PubMed Central

Bernardi, Nicolò F.; Darainy, Mohammad

2015-01-01

The early stages of motor skill acquisition are often marked by uncertainty about the sensory and motor goals of the task, as is the case in learning to speak or learning the feel of a good tennis serve. Here we present an experimental model of this early learning process, in which targets are acquired by exploration and reinforcement rather than sensory error. We use this model to investigate the relative contribution of motor and sensory factors to human motor learning. Participants make active reaching movements or matched passive movements to an unseen target using a robot arm. We find that learning through passive movements paired with reinforcement is comparable with learning associated with active movement, both in terms of magnitude and durability, with improvements due to training still observable at a 1 week retest. Motor learning is also accompanied by changes in somatosensory perceptual acuity. No stable changes in motor performance are observed for participants that train, actively or passively, in the absence of reinforcement, or for participants who are given explicit information about target position in the absence of somatosensory experience. These findings indicate that the somatosensory system dominates learning in the early stages of motor skill acquisition. SIGNIFICANCE STATEMENT The research focuses on the initial stages of human motor learning, introducing a new experimental model that closely approximates the key features of motor learning outside of the laboratory. The finding indicates that it is the somatosensory system rather than the motor system that dominates learning in the early stages of motor skill acquisition. This is important given that most of our computational models of motor learning are based on the idea that learning is motoric in origin. This is also a valuable finding for rehabilitation of patients with limited mobility as it shows that reinforcement in conjunction with passive movement results in benefits to motor learning that are as great as those observed for active movement training. PMID:26490869

What are the Effects of Protest Fear?

DTIC Science & Technology

2014-06-17

Acquisition Professional Development Program AT&L Acquisition, Technology, and Logistics BPA blanket purchase agreement CONUS continental United States...Blanket Purchase Agreement [ BPA ]) in order to avoid a bid protest. The data shows that 88 respondents had done so throughout their career with 4,139

Effects of environmental enrichment on behavioral deficits and alterations in hippocampal BDNF induced by prenatal exposure to morphine in juvenile rats.

PubMed

Ahmadalipour, A; Sadeghzadeh, J; Vafaei, A A; Bandegi, A R; Mohammadkhani, R; Rashidy-Pour, A

2015-10-01

Prenatal morphine exposure throughout pregnancy can induce a series of neurobehavioral and neurochemical disturbances by affecting central nervous system development. This study was designed to investigate the effects of an enriched environment on behavioral deficits and changes in hippocampal brain-derived neurotrophic factor (BDNF) levels induced by prenatal morphine in rats. On pregnancy days 11-18, female Wistar rats were randomly injected twice daily with saline or morphine. Offspring were weaned on postnatal day (PND) 21. They were subjected to a standard rearing environment or an enriched environment on PNDs 22-50. On PNDs 51-57, the behavioral responses including anxiety and depression-like behaviors, and passive avoidance memory as well as hippocampal BDNF levels were investigated. The light/dark (L/D) box and elevated plus maze (EPM) were used for the study of anxiety, forced swimming test (FST) was used to assess depression-like behavior and passive avoidance task was used to evaluate learning and memory. Prenatal morphine exposure caused a reduction in time spent in the EPM open arms and a reduction in time spent in the lit side of the L/D box. It also decreased step-through latency and increased time spent in the dark side of passive avoidance task. Prenatal morphine exposure also reduced immobility time and increased swimming time in FST. Postnatal rearing in an enriched environment counteracted with behavioral deficits in the EPM and passive avoidance task, but not in the L/D box. This suggests that exposure to an enriched environment during adolescence period alters anxiety profile in a task-specific manner. Prenatal morphine exposure reduced hippocampal BDNF levels, but enriched environment significantly increased BDNF levels in both saline- and morphine-exposed groups. Our results demonstrate that exposure to an enriched environment alleviates behavioral deficits induced by prenatal morphine exposure and up-regulates the decreased levels of BDNF. BDNF may contribute to the beneficial effects of an enriched environment on prenatal morphine-exposed to rats. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Applying Rapid Acquisition Policy Lessons for Defense Innovation

DTIC Science & Technology

2017-12-21

51 Applying Rapid Acquisition Policy Lessons for Defense Innovation Jonathan Wong Abstract: With the Department of Defense’s (DOD) recent focus on ...finds that DOD can incorporate innovation practices by dispersing organizations focused on new capabilities development across the agency to avoid...adjunct political scientist at the Rand Corporation. His research focuses on the intersection of new technology and defense acquisition. Prior to Rand

Acquisition of Programming Skills

DTIC Science & Technology

1990-04-01

skills (e.g., arithmetic reasoning, work knowledge, information processing speed); and c) passive versus active learning style. Ability measures...concurrent storage and processing an individual was capable of doing), and an active learning style. Implications of the findings for the development of

Effects of self-administered cocaine in adolescent and adult male rats on orbitofrontal cortex-related neurocognitive functioning

PubMed Central

Harvey, Roxann C.; Dembro, Kimberly A.; Rajagopalan, Kiran; Mutebi, Michael M.; Kantak, Kathleen M.

2010-01-01

Rationale Deficits in amygdala-related stimulus-reward learning are produced following 18 drug-free days of cocaine self-administration or its passive delivery in rats exposed during adulthood. No deficits in stimulus-reward learning are produced by cocaine exposure initiated during adolescence. Objectives To determine if age of initiating cocaine exposure differentially affects behavioral functioning of an additional memory system linked to cocaine addiction, the orbitofrontal cortex. Materials and methods A yoked-triad design (n=8) was used. One rat controlled cocaine delivery and the other two passively received cocaine or saline. Rats controlling drug delivery (1.0 mg/kg) self-administered cocaine from either P37–P59 or P77–P99, and then underwent 18 drug-free days (P60–P77 vs. P100–P117). Rats next were tested for acquisition of odor-delayed win-shift behavior conducted over 15 sessions (P78–P96 vs. P118–P136). Results Cocaine self-administration did not differ between adults and adolescents. During the test phase of the odor-delayed win-shift task (relatively difficult task demands), rats from both drug-onset ages showed learning deficits. Rats with cocaine self-administration experience committed more errors and had longer session latencies compared to rats passively receiving saline or cocaine. Rats with adolescent-onset cocaine self-administration experience showed an additional learning deficit by requiring more sessions to reach criterion levels for task acquisition compared to same-aged passive saline controls or rats with adult-onset cocaine self-administration experience. Rats passively receiving cocaine did not differ from the passive saline control from either age group. Conclusions Rats with adolescent-onset cocaine self-administration experience were more impaired in an orbitofrontal cortex-related learning task than rats with adult-onset cocaine self-administration experience. PMID:19513699

Voice Technology Design Guides for Navy Training Systems.

DTIC Science & Technology

1983-03-01

34 LSO acknowledges (AUTOIMANUAL/ pilot meatball Coupled as acquisition. appropriate) "Paddles Contact" LSO assuming control from CCA. (continued) 68... meatball to avoid ball to avoid settling slope if not corrected. settling below glide- below glideslope. slope. "Don’t climb"- If not corrected air...Check sink rate and Check sink rate and meat- "Don’t go high." craft will climb above meatball to avoid ball to avoid climbing optimum glideslope

The role of social cognition in parasite and pathogen avoidance.

PubMed

Kavaliers, Martin; Choleris, Elena

2018-07-19

The acquisition and use of social information are integral to social behaviour and parasite/pathogen avoidance. This involves social cognition which encompasses mechanisms for acquiring, processing, retaining and acting on social information. Social cognition entails the acquisition of social information about others (i.e. social recognition) and from others (i.e. social learning). Social cognition involves assessing other individuals and their infection status and the pathogen and parasite threat they pose and deciding about when and how to interact with them. Social cognition provides a framework for examining pathogen and parasite avoidance behaviours and their associated neurobiological mechanisms. Here, we briefly consider the relationships between social cognition and olfactory-mediated pathogen and parasite avoidance behaviours. We briefly discuss aspects of (i) social recognition of actual and potentially infected individuals and the impact of parasite/pathogen threat on mate and social partner choice; (ii) the roles of 'out-groups' (strangers, unfamiliar individuals) and 'in-groups' (familiar individuals) in the expression of parasite/pathogen avoidance behaviours; (iii) individual and social learning, i.e. the utilization of the pathogen recognition and avoidance responses of others; and (iv) the neurobiological mechanisms, in particular the roles of the nonapeptide, oxytocin and steroid hormones (oestrogens) associated with social cognition and parasite/pathogen avoidance.This article is part of the Theo Murphy meeting issue 'Evolution of pathogen and parasite avoidance behaviours'. © 2018 The Author(s).

Enhanced Cognitive Effects of Demethoxycurcumin, a Natural Derivative of Curcumin on Scopolamine-Induced Memory Impairment in Mice.

PubMed

Lim, Dong Wook; Son, Hyun Jung; Um, Min Young; Kim, In-Ho; Han, Daeseok; Cho, Suengmok; Lee, Chang-Ho

2016-08-05

In the present study, we examined the ameliorating effects of demethoxycurcumin (DMC) on memory impairment induced by scopolamine using passive avoidance and Morris water maze tests in mice. Moreover, to determine the neurobiological effects underlying the ameliorating effects of the DMC, choline acetyltransferase (ChAT) immunoreactivity was evaluated in mice exposed to scopolamine. Our results demonstrated that chronic oral administration (28 days) of DMC (10 mg/kg) improved scopolamine-induced learning impairment in the passive avoidance task and memory impairment in the Morris water maze. Moreover, Choline acetyltransferase (ChAT) activity in the DMC-treated group was significantly increased to 33.03% compared with the control group. Our present finding suggests that DMC ameliorates memory impairments induced by scopolamine treatment through reversing the reduction of hippocampal ChAT expression in mice.

Learning and extinction of a passive avoidance response in mice with high levels of predisposition to catalepsy.

PubMed

Dubrovina, N I; Zinov'ev, D R; Zinov'eva, D V; Kulikov, A V

2009-06-01

This report presents results obtained from comparative analysis of learning and the dynamics of extinction of a conditioned passive avoidance response in ASC mice, which were bred for a high level of predisposition to catalepsy, and in CBA and AKR mice. The following findings were obtained: 1) impairments to the extinction of the memory of fear represent an important symptom of depression in ASC mice; 2) extinction is delayed in CBA mice; and 3) new inhibitory learning occurs quickly in AKR mice. Prolonged retention of the fear memory in ASC mice appears to be related to increased anxiety on prolonged testing without a punishment. The deficit of inhibition of the fear reaction in ASC mice allows this strain to be regarded as a genetic model of depression.

Object relations, reality testing, and social withdrawal in schizophrenia and bipolar disorder.

PubMed

Hansen, Charlotte Fredslund; Torgalsbøen, Anne-Kari; Røssberg, Jan Ivar; Romm, Kristin Lie; Andreassen, Ole Andreas; Bell, Morris D; Melle, Ingrid

2013-03-01

In this study, we investigated the relationships between observed social withdrawal (Positive and Negative Syndrome Scale [PANSS] Passive Social Withdrawal and PANSS Active Social Avoidance), subjectively experienced social withdrawal (Social Functioning Scale [SFS] Withdrawal and SFS Interpersonal Behavior), and their associations to the underlying psychological patterns of Object Relations and Reality Testing. Patients with schizophrenia (n = 55) and bipolar disorder (n = 51) from the ongoing Thematically Organized Psychosis project, Oslo University Hospital, Norway, were evaluated using the Bell Object Relations and Reality Testing Inventory, the PANSS, and the SFS. Object relations and reality testing subscales related differentially to PANSS Passive Social Withdrawal and PANSS Active Social Avoidance. These two measures, together with the level of alienation, explained a significant amount of variance in self-experienced social dysfunction. Findings reveal the multidimensional nature of social dysfunction in severe mental disorders.

Youth with substance abuse histories exhibit dysfunctional representation of expected value during a passive avoidance task.

PubMed

White, Stuart F; Tyler, Patrick; Botkin, Mary L; Erway, Anna K; Thornton, Laura C; Kolli, Venkata; Pope, Kayla; Meffert, Harma; Blair, R James

2016-11-30

Individuals with substance abuse (SA) histories show impairment in the computations necessary for decision-making, including expected value (EV) and prediction error (PE). Neuroimaging findings, however, have been inconsistent. Sixteen youth with (SA positive ) and 29 youth without (SA negative ) substance abuse histories completed a passive avoidance task while undergoing functional MRI. The groups did not significantly differ on age, gender composition or IQ. Behavioral results indicated that SA positive youth showed significantly less learning than SA negative youth over the task. SA positive youth show problems representing EV information when attempting to avoid sub-optimal choices in bilateral inferior frontal gyrus and striatum. Furthermore, SA positive youth showed a significantly increased differential response to reward versus punishment feedback modulated by PE in posterior cingulate cortex relative to SA negative youth. Disrupted decision-making is likely to exacerbate SA as a failure to represent EV during the avoidance of sub-optimal choices is likely to increase the likelihood of SA. With respect to the representation of PE, future work will be needed to clarify the impact of different substances on the neural systems underpinning PE representation. Moreover, interaction of age/development and substance abuse on PE signaling will need to be explored. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Passive Seismic for Hydrocarbon Indicator : Between Expectation and Reality

NASA Astrophysics Data System (ADS)

Pandito, Riky H. B.

2018-03-01

In between 5 – 10 years, in our country, passive seismic method became more popular to finding hydrocarbon. Low price, nondestructive acquisition and easy to mobilization is the best reason for choose the method. But in the other part, some people are pessimistically to deal with the result. Instrument specification, data condition and processing methods is several points which influence characteristic and interpretation passive seismic result. In 2010 one prospect in East Java Basin has been measurement constist of 112 objective points and several calibration points. Data measurement results indicate a positive response. Furthermore, in 2013 exploration drliing conducted on the prospect. Drill steam test showes 22 MMCFD in objective zone, upper – late oligocene. In 2015, remeasurement taken in objective area and show consistent responses with previous measurement. Passive seismic is unique method, sometimes will have difference results on dry, gas and oil area, in field production and also temporary suspend area with hidrocarbon content.

26 CFR 1.269-4 - Power of district director to allocate deduction, credit, or allowance in part.

Code of Federal Regulations, 2010 CFR

2010-04-01

... evasion or avoidance of Federal income tax for which the acquisition was made. The district director is...(a), but only to such extent as he determines will not result in the evasion or avoidance of Federal...

A painless and constraint-free method to estimate viscoelastic passive dynamics of limbs' joints to support diagnosis of neuromuscular diseases.

PubMed

Venture, Gentiane; Nakamura, Yoshihiko; Yamane, Katsu; Hirashima, Masaya

2007-01-01

Though seldom identified, the human joints dynamics is important in the fields of medical robotics and medical research. We present a general solution to estimate in-vivo and simultaneously the passive dynamics of the human limbs' joints. It is based on the use of the multi-body description of the human body and its kinematics and dynamics computations. The linear passive joint dynamics of the shoulders and the elbows: stiffness, viscosity and friction, is estimated simultaneously using the linear least squares method. Acquisition of movements is achieved with an optical motion capture studio on one examinee during the clinical diagnosis of neuromuscular diseases. Experimental results are given and discussed.

Design of short-range terahertz wave passive detecting system

NASA Astrophysics Data System (ADS)

Zhang, Chao; Lou, Guowei; Zhu, Li; Qian, Songsong; Li, Ting

2016-09-01

Based on the study of radiation and transmission characteristics on THz waveband, a short-range passive detecting system is designed. The scheme originated from microwave passive detecting system. A prototype was developed following the design of key components including antennas and a harmonic mixer. The system operated at 0.36 THz. A dual-beam Cassegrain antenna was adopted for receiving signals which radiated by object and background. Local oscillator signal was generated by frequency multiplication. Harmonic mixing is adopted for reducing local oscillator signal frequency required by half. Superheterodyne technology is employed for signal acquisition. The system implemented easily. Tests and measurements were taken, which showed that the scheme was feasible and the performance of the prototype system met the design requirements.

Velocity filtering applied to optical flow calculations

NASA Technical Reports Server (NTRS)

Barniv, Yair

1990-01-01

Optical flow is a method by which a stream of two-dimensional images obtained from a forward-looking passive sensor is used to map the three-dimensional volume in front of a moving vehicle. Passive ranging via optical flow is applied here to the helicopter obstacle-avoidance problem. Velocity filtering is used as a field-based method to determine range to all pixels in the initial image. The theoretical understanding and performance analysis of velocity filtering as applied to optical flow is expanded and experimental results are presented.

Passive versus active hazard detection and avoidance systems

NASA Astrophysics Data System (ADS)

Neveu, D.; Mercier, G.; Hamel, J.-F.; Simard Bilodeau, V.; Woicke, S.; Alger, M.; Beaudette, D.

2015-06-01

Upcoming planetary exploration missions will require advanced guidance, navigation and control technologies to reach landing sites with high precision and safety. Various technologies are currently in development to meet that goal. Some technologies rely on passive sensors and benefit from the low mass and power of such solutions while others rely on active sensors and benefit from an improved robustness and accuracy. This paper presents two different hazard detection and avoidance (HDA) system design approaches. The first architecture relies only on a camera as the passive HDA sensor while the second relies, in addition, on a Lidar as the active HDA sensor. Both options use in common an innovative hazard map fusion algorithm aiming at identifying the safest landing locations. This paper presents the simulation tools and reports the closed-loop software simulation results obtained using each design option. The paper also reports the Monte Carlo simulation campaign that was used to assess the robustness of each design option. The performance of each design option is compared against each other in terms of performance criteria such as percentage of success, mean distance to nearest hazard, etc. The applicability of each design option to planetary exploration missions is also discussed.

76 FR 9714 - Defense Federal Acquisition Regulation Supplement; Passive Radio Frequency Identification (DFARS...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-22

... materials, including pharmaceuticals (excluding biologicals, and reagents--suppliers should limit the mixing... concrete or similar construction materials. (5) Coal or combustibles such as firewood. (6) Agricultural... Class VIII--Medical materials including pharmaceuticals, (excluding biologicals, and reagents--suppliers...

Passive appendages improve the maneuverability of fish-like robots

NASA Astrophysics Data System (ADS)

Pollard, Beau; Tallapragada, Phanindra

2017-11-01

It is known that the passive mechanics of fish appendages play a role in the high efficiency of their swimming. A well known example of this is the experimental demonstration that a dead fish could swim upstream. However little is known about the role if any of passive deformations of a fish-like body that could aid in its maneuverability. Part of the difficulty investigating this lies in clearly separating the role of actuated body deformations and passive deformations in response to the fluid structure interaction. In this paper we compare the maneuverability of several fish shaped robotic models that possess varying numbers of passive appendages with a fish shaped robot that has no appendages. All the robots are propelled by the oscillations of an internal momentum wheel thereby eliminating any active deformations of the body. Our experiments clearly reveal the significant improvement in maneuverability of robots with passive appendages. In the broader context of swimming robots our experiments show that passive mechanisms could be useful to provide mechanical feedback that can help maneuverability and obstacle avoidance along with propulsive efficiency. This work was partly supported by a Grant from the NSF CMMI 1563315.

Memory Formation: Evidence for a Specific Neurochemical System in the Amygdala

ERIC Educational Resources Information Center

Gallagher, Michela; And Others

1977-01-01

Reports bita-Adrenergic antagonists injected into rats trained in a passive avoidance task produced time-dependent and dose-dependent decreases in retention of the task. Results were stereospecific and reversed by norepinephrine. (SL)

Aircraft wake vortex measurements at Denver International Airport

DOT National Transportation Integrated Search

2004-05-10

Airport capacity is constrained, in part, by spacing requirements associated with the wake vortex hazard. NASA's Wake Vortex Avoidance Project has a goal to establish the feasibility of reducing this spacing while maintaining safety. Passive acoustic...

Li-air batteries: Decouple to stabilize

NASA Astrophysics Data System (ADS)

Xu, Ji-Jing; Zhang, Xin-Bo

2017-09-01

The utilization of porous carbon cathodes in lithium-air batteries is hindered by their severe decomposition during battery cycling. Now, dual redox mediators are shown to decouple the complex electrochemical reactions at the cathode, avoiding cathode passivation and decomposition.

Comparison of Nootropic and Neuroprotective Features of Aryl-Substituted Analogs of Gamma-Aminobutyric Acid.

PubMed

Tyurenkov, I N; Borodkina, L E; Bagmetova, V V; Berestovitskaya, V M; Vasil'eva, O S

2016-02-01

GABA analogs containing phenyl (phenibut) or para-chlorophenyl (baclofen) substituents demonstrated nootropic activity in a dose of 20 mg/kg: they improved passive avoidance conditioning, decelerated its natural extinction, and exerted antiamnestic effect on the models of amnesia provoked by scopolamine or electroshock. Tolyl-containing GABA analog (tolibut, 20 mg/kg) exhibited antiamnestic activity only on the model of electroshock-induced amnesia. Baclofen and, to a lesser extent, tolibut alleviated seizures provoked by electroshock, i.e. both agents exerted anticonvulsant effect. All examined GABA aryl derivatives demonstrated neuroprotective properties on the maximum electroshock model: they shortened the duration of coma and shortened the period of spontaneous motor activity recovery. In addition, these agents decreased the severity of passive avoidance amnesia and behavioral deficit in the open field test in rats exposed to electroshock. The greatest neuroprotective properties were exhibited by phenyl-containing GABA analog phenibut.

Coping behavior and loneliness among obese patients.

PubMed

Hörchner, Rogier; Tuinebreijer, Wim E; Kelder, Hans; van Urk, Elly

2002-12-01

Morbid obesity can be accompanied by physical and social problems that may influence interpersonal relationships and the recruitment of social support. The problems can be tackled with a variety of coping strategies. 104 patients with a body mass index (BMI) 32-64 kg/m2 and mean age 36 yr were presented with the Utrecht Coping List (UCL) and the Loneliness Scale. Of these patients, 94 were female, and this cohort was analyzed more extensively. Patients exhibited elevated values on the Loneliness Scale and in the UCL sub-scales palliative response, avoidance / wait-and-see, passive / depressive response pattern and expression of emotions / anger. The active approach UCL sub-scale scored lower than in a control group. Obese female patients displayed avoidance, wait-and-see and passive response pattern as coping behavior, experiencing their intimate relationships as relatively unreliable and not very intimate. More research is needed to determine the effect of coping behavior on therapeutic effect.

The effect of lithium chloride on one-trial passive avoidance learning in rats.

PubMed Central

Johnson, F N

1976-01-01

1 Expression of a one-trial passive avoidance learning response in rats was examined following injections of lithium chloride or sodium chloride before and after initial training and before the first day of testing. Five tests were given at daily intervals, 24 h after training being the time of the first test. 2. Lithium given before the first day of testing impaired response expression on the first and all subsequent days of testing; the rate of extinction was unaffected. 3. Given both before and immediately after initial training, lithium impaired response expression on the first day of testing but slowed down the subsequent rate of extinction, leading eventually to improved performance on the fifth day, as compared with placebo-treated control subjects. 4. The results are interpreted in the light of the hypothesis that lithium impaired the central processing of sensory information. PMID:1252666

Compressive passive millimeter wave imager

DOEpatents

Gopalsami, Nachappa; Liao, Shaolin; Elmer, Thomas W; Koehl, Eugene R; Heifetz, Alexander; Raptis, Apostolos C

2015-01-27

A compressive scanning approach for millimeter wave imaging and sensing. A Hadamard mask is positioned to receive millimeter waves from an object to be imaged. A subset of the full set of Hadamard acquisitions is sampled. The subset is used to reconstruct an image representing the object.

Active music classes in infancy enhance musical, communicative and social development.

PubMed

Gerry, David; Unrau, Andrea; Trainor, Laurel J

2012-05-01

Previous studies suggest that musical training in children can positively affect various aspects of development. However, it remains unknown as to how early in development musical experience can have an effect, the nature of any such effects, and whether different types of music experience affect development differently. We found that random assignment to 6 months of active participatory musical experience beginning at 6 months of age accelerates acquisition of culture-specific knowledge of Western tonality in comparison to a similar amount of passive exposure to music. Furthermore, infants assigned to the active musical experience showed superior development of prelinguistic communicative gestures and social behaviour compared to infants assigned to the passive musical experience. These results indicate that (1) infants can engage in meaningful musical training when appropriate pedagogical approaches are used, (2) active musical participation in infancy enhances culture-specific musical acquisition, and (3) active musical participation in infancy impacts social and communication development. © 2012 Blackwell Publishing Ltd.

[A comparative analysis of the passive electric probe detection and spectrum diagnosis of laser-induced plasma].

PubMed

Liu, Tong; Yang, Li-Jun; Wang, Li-Jun; Wang, Lang-Ping

2014-02-01

An approach to detecting laser-induced plasma using passive probe was brought up. The plasma of laser welding was studied by using a synchronous electric and spectral information acquisition system, the laser-induced plasma was detected by a passive electric probe and fiber spectrometer, the electrical signal was analyzed on the basis of the theory of plasma sheath, and the temperature of laser-induced plasma was calculated by using the method of relative spectral intensity. The analysis results from electrical signal and spectral one were compared. Calculation results of three kinds of surface circumstances, which were respectively coated by KF, TiO2 and without coating, were compared. The factors affecting the detection accuracy were studied. The results indicated that the results calculated by passive probe matched that by spectral signal basically, and the accuracy was affected by ions mass of the plasma. The designed passive electric probe can be used to reflect the continuous fluctuation of electron temperature of the generated plasma, and monitor the laser-induced plasma.

Active prospective control is required for effective sensorimotor learning.

PubMed

Snapp-Childs, Winona; Casserly, Elizabeth; Mon-Williams, Mark; Bingham, Geoffrey P

2013-01-01

Passive modeling of movements is often used in movement therapy to overcome disabilities caused by stroke or other disorders (e.g. Developmental Coordination Disorder or Cerebral Palsy). Either a therapist or, recently, a specially designed robot moves or guides the limb passively through the movement to be trained. In contrast, action theory has long suggested that effective skill acquisition requires movements to be actively generated. Is this true? In view of the former, we explicitly tested the latter. Previously, a method was developed that allows children with Developmental Coordination Disorder to produce effective movements actively, so as to improve manual performance to match that of typically developing children. In the current study, we tested practice using such active movements as compared to practice using passive movement. The passive movement employed, namely haptic tracking, provided a strong test of the comparison, one that showed that the mere inaction of the muscles is not the problem. Instead, lack of prospective control was. The result was no effective learning with passive movement while active practice with prospective control yielded significant improvements in performance.

Effects of aniracetam on one-trial passive avoidance tests and cholinergic neurons in discrete brain regions of rats.

PubMed

Toide, K

1989-01-01

Using rats in one-trial passive avoidance tests, the anti-amnesic effects of the nootropic drug aniracetam were investigated; moreover, the action of aniracetam upon the cholinergic system in the brain was studied. In one-trial passive avoidance tests, aniracetam prolonged significantly the retention time for 100 mg/kg, p.o. However, the retention-prolonging effect was diminished when the dose was increased to 300 mg/kg p.o. Investigation of the action of the drug upon the cholinergic system revealed that ACh and choline content in the corpus striatum was not increased by any doses of aniracetam. ACh content in the hippocampus was increased by doses of 100-300 mg/kg, p.o., but choline was not significantly increased by any doses, while in the cerebral cortex ACh content was significantly increased by a dose of 300 mg/kg, p.o. In addition, the decrease in hippocampal ACh and choline content following an injection of scopolamine was lessened by aniracetam 100 mg/kg, p.o. and 100-300 mg/kg, respectively. In order to elucidate the mechanism of these actions of aniracetam, the ACh-releasing action and changes in choline content of the extracellular spaces in the hippocampus were investigated, but no effects were observed. The results obtained indicate that aniracetam has an inhibitory effect upon scopolamine-induced amnesia. The mechanism of this effect may be an action upon the cholinergic system; therefore, some action with respect to the impairment of cholinergic neurotransmission in the hippocampus induced by scopolamine appears to be of particular importance.

Divergent stress responses and coping styles in psychogenetically selected Roman high-(RHA) and low-(RLA) avoidance rats: behavioural, neuroendocrine and developmental aspects.

PubMed

Steimer, Thierry; Driscoll, Peter

2003-06-01

The Swiss sublines of Roman high-(RHA/Verh) and low-(RLA/Verh) avoidance rats have been genetically selected for good vs. poor performance in two-way active avoidance since 1972. RLA/Verh rats show increased stress responses (e.g. freezing behaviour, ACTH, corticosterone and prolactin secretion) and adopt a more passive (or reactive) coping style when confronted with a novel environment. In the open field, elevated plus-maze, black/white box test, and in a new light/dark open field test, RLA/Verh rats appear to be more anxious than their RHA/Verh counterparts. Anxiety may result from their particular psychophysiological profile, i.e. increased emotionality combined with a passive coping style. In contrast, RHA/Verh rats are less responsive to stress, they show little anxiety in novel situations and tend to be impulsive and novelty (sensation) seekers. Some behavioural differences are already noticeable shortly after birth, but the full pattern appears to stabilize only after puberty. Gene-environment interactions are critical in establishing this pattern. The data reviewed indicate that the differences between RHA/Verh and RLA/Verh rats probably result from a complex interaction among divergent anxiety/emotionality characteristics, differences in locomotor activity and novelty/reward seeking, as well as active vs. passive coping styles. It is proposed further that these divergent personality types are to be found not only in other selective breeding programs but in the form of individual differences in most populations of rats used for this type of research.

Passive Avoidance Training and Recall are Associated With Increased Glutamate Levels in the Intermediate Medial Hyperstriatum Ventrale of the Day-Old Chick

PubMed Central

Daisley, Jonathan N.; Gruss, Michael; Rose, Steven P. R.; Braun, Katharina

1998-01-01

In the young chick, the intermediate medial hyperstriatum ventrale is involved in learning paradigms, including imprinting and passive avoidance learning. Biochemical changes in the intermediate medial hyperstriatum ventrale following learning include an up-regulation of amino-acid transmitter levels and receptor activity. To follow the changes of extracellular amino acid levels during passive avoidance training, we used an in vivo microdialysis technique. Probes were implanted in chicks before training the animals, either on a methyl- anthranylate-or water-coated bead. One hour later, recall was tested in both groups by presenting a similar bead. An increase of extra-cellular glutamate levels accompanied training and testing in both groups; during training, glutamate release was higher in methylanthranylate- trained than in water-trained chicks. When compared with the methylanthranylate-trained chicks during testing, the water-trained chicks showed enhanced extra-cellular glutamate levels. No other amino acid examined showed significant changes. After testing, the chicks were anesthetized and release- stimulated with an infusion of 50 mM potassium. Extra-cellular glutamate and taurine levels were significantly increased in both methylanthranylate-and water-trained chicks. The presentation of methylanthranylate as an. olfactory stimulus significantly enhanced glutamate levels, especially in methylanthranylate-trained chicks. The results suggest that such changes in extra-cellular glutamate levels in the intermediate medial hyperstriatum ventrale accompany pecking at either the water- or the methylanthranylate-bead. The taste of the aversant may be responsible for the greater increases found in methylanthranylate-trained birds. PMID:9920682

Effects of the estrous cycle and ovarian hormones on behavioral indices of anxiety in female rats.

PubMed

Mora, S; Dussaubat, N; Díaz-Véliz, G

1996-10-01

The influence of the estrous cycle and the effects of exogenous administration of estradiol and progesterone on level of anxiety were studied in intact and ovariectomized rats. Intact Sprague-Dawley female rats were classified according to the stages of estrous cycle. Another group of rats was ovariectomized bilaterally and, 14 days after surgery, they received estradiol benzoate (10 micrograms/kg, s.c.) and/or progesterone (25 mg/kg, s.c.) or corn oil (1 ml/kg). The behavioral tests began 3 h after estradiol or 6 h after progesterone and consisted of: (1) exploration of an elevated plus-maze; and (2) retention of a passive avoidance response. Open-arm exploration of the plus-maze varied according to light intensity and the stages of the estrous cycle. There was a slight increase in open-arm exploration by rats in metestrus, under high light intensity. Low light intensity increased the exploration of the open arms by rats in proestrus and estrus, compared to the other phases of the cycle. Retention of the passive avoidance response was inhibited during proestrus and estrus. Progesterone increased open-arm exploration of the plus-maze under high light conditions, whereas estradiol antagonized this effect. Retention of passive avoidance was inhibited after estradiol or progesterone injection. These results suggest that the behavioral indices of anxiety can vary across the estrous cycle, that low light intensities have anxiolytic-like effects, and that the sensitivity to this effect is higher during proestrus and estrus. This could be explained through modulatory effects of ovarian hormones upon behavioral indices of anxiety.

Animal models.

PubMed

Walker, Ellen A

2010-01-01

As clinical studies reveal that chemotherapeutic agents may impair several different cognitive domains in humans, the development of preclinical animal models is critical to assess the degree of chemotherapy-induced learning and memory deficits and to understand the underlying neural mechanisms. In this chapter, the effects of various cancer chemotherapeutic agents in rodents on sensory processing, conditioned taste aversion, conditioned emotional response, passive avoidance, spatial learning, cued memory, discrimination learning, delayed-matching-to-sample, novel-object recognition, electrophysiological recordings and autoshaping is reviewed. It appears at first glance that the effects of the cancer chemotherapy agents in these many different models are inconsistent. However, a literature is emerging that reveals subtle or unique changes in sensory processing, acquisition, consolidation and retrieval that are dose- and time-dependent. As more studies examine cancer chemotherapeutic agents alone and in combination during repeated treatment regimens, the animal models will become more predictive tools for the assessment of these impairments and the underlying neural mechanisms. The eventual goal is to collect enough data to enable physicians to make informed choices about therapeutic regimens for their patients and discover new avenues of alternative or complementary therapies that reduce or eliminate chemotherapy-induced cognitive deficits.

Comprehensive analysis of information dissemination in disasters

NASA Astrophysics Data System (ADS)

Zhang, N.; Huang, H.; Su, Boni

2016-11-01

China is a country that experiences a large number of disasters. The number of deaths caused by large-scale disasters and accidents in past 10 years is around 900,000. More than 92.8 percent of these deaths could be avoided if there were an effective pre-warning system deployed. Knowledge of the information dissemination characteristics of different information media taking into consideration governmental assistance (information published by a government) in disasters in urban areas, plays a critical role in increasing response time and reducing the number of deaths and economic losses. In this paper we have developed a comprehensive information dissemination model to optimize efficiency of pre-warning mechanics. This model also can be used for disseminating information for evacuees making real-time evacuation plans. We analyzed every single information dissemination models for pre-warning in disasters by considering 14 media: short message service (SMS), phone, television, radio, news portals, Wechat, microblogs, email, newspapers, loudspeaker vehicles, loudspeakers, oral communication, and passive information acquisition via visual and auditory senses. Since governmental assistance is very useful in a disaster, we calculated the sensitivity of governmental assistance ratio. The results provide useful references for information dissemination during disasters in urban areas.

Comparison of fMRI data from passive listening and active-response story processing tasks in children.

PubMed

Vannest, Jennifer J; Karunanayaka, Prasanna R; Altaye, Mekibib; Schmithorst, Vincent J; Plante, Elena M; Eaton, Kenneth J; Rasmussen, Jerod M; Holland, Scott K

2009-04-01

To use functional MRI (fMRI) methods to visualize a network of auditory and language-processing brain regions associated with processing an aurally-presented story. We compare a passive listening (PL) story paradigm to an active-response (AR) version including online performance monitoring and a sparse acquisition technique. Twenty children (ages 11-13 years) completed PL and AR story processing tasks. The PL version presented alternating 30-second blocks of stories and tones; the AR version presented story segments, comprehension questions, and 5-second tone sequences, with fMRI acquisitions between stimuli. fMRI data was analyzed using a general linear model approach and paired t-test identifying significant group activation. Both tasks showed activation in the primary auditory cortex, superior temporal gyrus bilaterally, and left inferior frontal gyrus (IFG). The AR task demonstrated more extensive activation, including the dorsolateral prefrontal cortex and anterior/posterior cingulate cortex. Comparison of effect size in each paradigm showed a larger effect for the AR paradigm in a left inferior frontal region-of-interest (ROI). Activation patterns for story processing in children are similar in PL and AR tasks. Increases in extent and magnitude of activation in the AR task are likely associated with memory and attention resources engaged across acquisition intervals.

Understanding avoidant leadership in health care: findings from a secondary analysis of two qualitative studies.

PubMed

Jackson, Debra; Hutchinson, Marie; Peters, Kath; Luck, Lauretta; Saltman, Deborah

2013-04-01

To illuminate ways that avoidant leadership can be enacted in contemporary clinical settings. Avoidance is identified in relation to laissez-faire leadership and passive avoidant leadership. However, the nature and characteristics of avoidance and how it can be enacted in a clinical environment are not detailed. This paper applied secondary analysis to data from two qualitative studies. We have identified three forms of avoidant leader response: placating avoidance, where leaders affirmed concerns but abstained from action; equivocal avoidance, where leaders were ambivalent in their response; and hostile avoidance, where the failure of leaders to address concerns escalated hostility towards the complainant. Through secondary analysis of two existing sets of data, we have shed new light on avoidant leaderships and how it can be enacted in contemporary clinical settings. Further work needs to be undertaken to better understand this leadership style. We recommend that organizations ensure that all nurse leaders are aware of how best to respond to concerns of wrongdoing and that mechanisms are created to ensure timely feedback is provided about the actions taken. © 2012 Blackwell Publishing Ltd.

Analysis of the 5-HT1A receptor involvement in passive avoidance in the rat

PubMed Central

Misane, Ilga; Johansson, Christina; Ove Ögren, Sven

1998-01-01

The effects of the 5-HT2A/2C agonist DOB, the selective 5-HT1A agonist NDO 008 (3-dipropylamino-5-hydroxychroman), and the two enantiomers of the selective 5-HT1A agonist 8-OH-DPAT (R(+)-8-OH-DPAT and S(−)-8-OH-DPAT) were studied in a step-through passive avoidance (PA) test in the male rat.The 5-HT1A agonists injected prior to training (conditioning) produced a dose-dependent impairment of PA retention when examined 24 h later. R(+)-8-OH-DPAT was four times more effective than S(−)-8-OH-DPAT to cause an impairment of PA retention. Both NDO 008 and the two enantiomers of 8-OH-DPAT induced the serotonin syndrome at the dose range that produced inhibition of the PA response, thus, indicating activation of postsynaptic 5-HT1A receptors.Neither NDO 008 nor R(+)-8-OH-DPAT induced head-twitches, a behavioural response attributed to stimulation of postsynaptic 5-HT2A receptors. In contrast, DOB induced head-twitches at the 0.01 mg kg−1 dose while a 200 times higher dose was required to produce a significant impairment of PA retention.The impairment of PA retention induced by both NDO 008 and R(+)-8-OH-DPAT was fully blocked by the active S(+)- enantiomer of the selective 5-HT1A antagonist WAY 100135 and the mixed 5-HT1A/β-adrenoceptor antagonist L(−)-alprenolol. In contrast, the mixed 5-HT2A/2C antagonists ketanserin and pirenperone were found to be ineffective. Moreover, the β2-adrenoceptor antagonist ICI 118551, the β1-antagonist metoprolol as well as the mixed β-adrenoceptor blocker D(+)-alprenolol all failed to modify the deficit of PA retention by NDO 008 and R(+)-8-OH-DPAT. None of the 5-HT1A or 5-HT2A/2C receptor antagonists tested or the β-blockers altered PA retention by themselves.A 3 day pretreatment procedure (200+100+100 mg kg−1) with the tryptophan hydroxylase inhibitor p-chlorophenylalanine (PCPA) did not alter PA retention and did not prevent the inhibitory action of the 5-HT1A agonists, indicating that their effects on PA do not depend on endogenous 5-HT.The effects of NDO 008 on PA were also studied using a state-dependent learning paradigm. NDO 008 was found to produce a disruption of PA when given either prior to training or retention or both prior to training and retention but it failed to affect PA retention when given immediately after training.These findings indicate that the deficit of passive avoidance retention induced by the 5-HT1A agonists is mainly a result of stimulation of postsynaptic 5-HT1A receptors but not 5-HT2A receptors. The 5-HT1A receptor stimulation appears to interfere with learning processes operating at both acquisition and retrieval. PMID:9806333

A Novel Approach to the Design of Passive Filters in Electric Grids

NASA Astrophysics Data System (ADS)

Filho da Costa Castro, José; Lima, Lucas Ramalho; Belchior, Fernando Nunes; Ribeiro, Paulo Fernando

2016-12-01

The design of shunt passive filters has been a topic of constant research since the 70's. Due to the lower cost, passive shunt filters are still considered a preferred option. This paper presents a novel approach for the placement and sizing of passive filters through ranking solutions based on the minimization of the total harmonic distortion (THDV) of the supply system rather than one specific bus, without neglecting the individual harmonic distortions. The developed method was implemented using Matlab/Simulink and applied to a test system. The results shown that is possible to minimize the total voltage harmonic distortion using a system approach during the filter selection. Additionally, since the method is mainly based on a heurist approach, it avoids the complexity associated with of use of advanced mathematical tools such as artificial intelligence techniques. The analyses contemplate a sinusoidal voltage utility and also the condition with background distortion utility.

Elastic Velocity Updating through Image-Domain Tomographic Inversion of Passive Seismic Data

NASA Astrophysics Data System (ADS)

Witten, B.; Shragge, J. C.

2014-12-01

Seismic monitoring at injection sites (e.g., CO2sequestration, waste water disposal, hydraulic fracturing) has become an increasingly important tool for hazard identification and avoidance. The information obtained from this data is often limited to seismic event properties (e.g., location, approximate time, moment tensor), the accuracy of which greatly depends on the estimated elastic velocity models. However, creating accurate velocity models from passive array data remains a challenging problem. Common techniques rely on picking arrivals or matching waveforms requiring high signal-to-noise data that is often not available for the magnitude earthquakes observed over injection sites. We present a new method for obtaining elastic velocity information from earthquakes though full-wavefield wave-equation imaging and adjoint-state tomography. The technique exploits images of the earthquake source using various imaging conditions based upon the P- and S-wavefield data. We generate image volumes by back propagating data through initial models and then applying a correlation-based imaging condition. We use the P-wavefield autocorrelation, S-wavefield autocorrelation, and P-S wavefield cross-correlation images. Inconsistencies in the images form the residuals, which are used to update the P- and S-wave velocity models through adjoint-state tomography. Because the image volumes are constructed from all trace data, the signal-to-noise in this space is increased when compared to the individual traces. Moreover, it eliminates the need for picking and does not require any estimation of the source location and timing. Initial tests show that with reasonable source distribution and acquisition array, velocity anomalies can be recovered. Future tests will apply this methodology to other scales from laboratory to global.

Germanium detector passivated with hydrogenated amorphous germanium

DOEpatents

Hansen, William L.; Haller, Eugene E.

1986-01-01

Passivation of predominantly crystalline semiconductor devices (12) is provided for by a surface coating (21) of sputtered hydrogenated amorphous semiconductor material. Passivation of a radiation detector germanium diode, for example, is realized by sputtering a coating (21) of amorphous germanium onto the etched and quenched diode surface (11) in a low pressure atmosphere of hydrogen and argon. Unlike prior germanium diode semiconductor devices (12), which must be maintained in vacuum at cryogenic temperatures to avoid deterioration, a diode processed in the described manner may be stored in air at room temperature or otherwise exposed to a variety of environmental conditions. The coating (21) compensates for pre-existing undesirable surface states as well as protecting the semiconductor device (12) against future impregnation with impurities.

Overpassivization in Second Language Acquisition

ERIC Educational Resources Information Center

Kondo, Takako

2005-01-01

An important problem for a language learner is identifying how properties of argument structure are realized morphosyntactically in the particular language they are learning. Speakers of some L1s overgeneralize the morphosyntactic reflexes of the movement of Theme objects in English to unaccusative intransitive verbs, using passive morphology in…

78 FR 6185 - Federal Acquisition Regulation; Prohibition on Contracting With Inverted Domestic Corporations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-29

... reincorporated in a tax haven; the major players in these transactions are reportedly the very large... should not be rewarded for tax avoidance. Comment: Many respondents stated that companies should not be rewarded for tax avoidance, which enables them to compete unfairly with U.S. companies. Response: The...

Spatial learning in the genetically heterogeneous NIH-HS rat stock and RLA-I/RHA-I rats: revisiting the relationship with unconditioned and conditioned anxiety.

PubMed

Martínez-Membrives, Esther; López-Aumatell, Regina; Blázquez, Gloria; Cañete, Toni; Tobeña, Adolf; Fernández-Teruel, Alberto

2015-05-15

To characterize learning/memory profiles for the first time in the genetically heterogeneous NIH-HS rat stock, and to examine whether these are associated with anxiety, we evaluated NIH-HS rats for spatial learning/memory in the Morris water maze (MWM) and in the following anxiety/fear tests: the elevated zero-maze (ZM; unconditioned anxiety), a context-conditioned fear test and the acquisition of two-way active avoidance (conditioned anxiety). NIH-HS rats were compared with the Roman High- (RHA-I) and Low-Avoidance (RLA-I) rat strains, given the well-known differences between the Roman strains/lines in anxiety-related behavior and in spatial learning/memory. The results show that: (i) As expected, RLA-I rats were more anxious in the ZM test, displayed more frequent context-conditioned freezing episodes and fewer avoidances than RHA-I rats. (ii) Scores of NIH-HS rats in these tests/tasks mostly fell in between those of the Roman rat strains, and were usually closer to the values of the RLA-I strain. (iii) Pigmented NIH-HS (only a small part of NIH-HS rats were albino) rats were the best spatial learners and displayed better spatial memory than the other three (RHA-I, RLA-I and NIH-HS albino) groups. (iv) Albino NIH-HS and RLA-I rats also showed better learning/memory than the RHA-I strain. (v) Within the NIH-HS stock, the most anxious rats in the ZM test presented the best learning and/or memory efficiency (regardless of pigmentation). In summary, NIH-HS rats display a high performance in spatial learning/memory tasks and a passive coping strategy when facing conditioned conflict situations. In addition, unconditioned anxiety in NIH-HS rats predicts better spatial learning/memory. Copyright © 2015 Elsevier Inc. All rights reserved.

Trends in federal land acquisition, protection strategies, and planning

Treesearch

Warren Brown

1980-01-01

In the past, Federal land acquisition has been one of the most popular ways to protect outstanding natural resources and provide recreational opportunities. Federal purchase, maintenance, and operation can help take pressure off the State or local budget. Federal involvement also can provide a way for local officials to avoid making some tough decisions about...

Access Denied? Twenty-First-Century Technology in Schools

ERIC Educational Resources Information Center

Male, Trevor; Burden, Kevin

2014-01-01

This article considers how developments in technologies have transformed the kind of social interaction possible over the Internet, making it feasible to undertake discourse and dialogue without having to rely solely on text-based mediation. This represents a fundamental change to learning, shifting from passive acquisition of someone else's ideas…

Magnetic Field Response Measurement Acquisition System

NASA Technical Reports Server (NTRS)

Woodard, Stanley E.; Taylor, Bryant D.; Shams, Qamar A.; Fox, Robert L.

2005-01-01

A measurement acquisition method that alleviates many shortcomings of traditional measurement systems is presented in this paper. The shortcomings are a finite number of measurement channels, weight penalty associated with measurements, electrical arcing, wire degradations due to wear or chemical decay and the logistics needed to add new sensors. The key to this method is the use of sensors designed as passive inductor-capacitor circuits that produce magnetic field responses. The response attributes correspond to states of physical properties for which the sensors measure. A radio frequency antenna produces a time-varying magnetic field used to power the sensor and receive the magnetic field response of the sensor. An interrogation system for discerning changes in the sensor response is presented herein. Multiple sensors can be interrogated using this method. The method eliminates the need for a data acquisition channel dedicated to each sensor. Methods of developing magnetic field response sensors and the influence of key parameters on measurement acquisition are discussed.

fastSIM: a practical implementation of fast structured illumination microscopy.

PubMed

Lu-Walther, Hui-Wen; Kielhorn, Martin; Förster, Ronny; Jost, Aurélie; Wicker, Kai; Heintzmann, Rainer

2015-01-16

A significant improvement in acquisition speed of structured illumination microscopy (SIM) opens a new field of applications to this already well-established super-resolution method towards 3D scanning real-time imaging of living cells. We demonstrate a method of increased acquisition speed on a two-beam SIM fluorescence microscope with a lateral resolution of ~100 nm at a maximum raw data acquisition rate of 162 frames per second (fps) with a region of interest of 16.5  ×  16.5 µm 2 , free of mechanically moving components. We use a programmable spatial light modulator (ferroelectric LCOS) which promises precise and rapid control of the excitation pattern in the sample plane. A passive Fourier filter and a segmented azimuthally patterned polarizer are used to perform structured illumination with maximum contrast. Furthermore, the free running mode in a modern sCMOS camera helps to achieve faster data acquisition.

fastSIM: a practical implementation of fast structured illumination microscopy

NASA Astrophysics Data System (ADS)

Lu-Walther, Hui-Wen; Kielhorn, Martin; Förster, Ronny; Jost, Aurélie; Wicker, Kai; Heintzmann, Rainer

2015-03-01

A significant improvement in acquisition speed of structured illumination microscopy (SIM) opens a new field of applications to this already well-established super-resolution method towards 3D scanning real-time imaging of living cells. We demonstrate a method of increased acquisition speed on a two-beam SIM fluorescence microscope with a lateral resolution of ~100 nm at a maximum raw data acquisition rate of 162 frames per second (fps) with a region of interest of 16.5  ×  16.5 µm2, free of mechanically moving components. We use a programmable spatial light modulator (ferroelectric LCOS) which promises precise and rapid control of the excitation pattern in the sample plane. A passive Fourier filter and a segmented azimuthally patterned polarizer are used to perform structured illumination with maximum contrast. Furthermore, the free running mode in a modern sCMOS camera helps to achieve faster data acquisition.

Dopamine and Octopamine Influence Avoidance Learning of Honey Bees in a Place Preference Assay

PubMed Central

Agarwal, Maitreyi; Giannoni Guzmán, Manuel; Morales-Matos, Carla; Del Valle Díaz, Rafael Alejandro; Abramson, Charles I.; Giray, Tugrul

2011-01-01

Biogenic amines are widely characterized in pathways evaluating reward and punishment, resulting in appropriate aversive or appetitive responses of vertebrates and invertebrates. We utilized the honey bee model and a newly developed spatial avoidance conditioning assay to probe effects of biogenic amines octopamine (OA) and dopamine (DA) on avoidance learning. In this new protocol non-harnessed bees associate a spatial color cue with mild electric shock punishment. After a number of experiences with color and shock the bees no longer enter the compartment associated with punishment. Intrinsic aspects of avoidance conditioning are associated with natural behavior of bees such as punishment (lack of food, explosive pollination mechanisms, danger of predation, heat, etc.) and their association to floral traits or other spatial cues during foraging. The results show that DA reduces the punishment received whereas octopamine OA increases the punishment received. These effects are dose-dependent and specific to the acquisition phase of training. The effects during acquisition are specific as shown in experiments using the antagonists Pimozide and Mianserin for DA and OA receptors, respectively. This study demonstrates the integrative role of biogenic amines in aversive learning in the honey bee as modeled in a novel non-appetitive avoidance learning assay. PMID:21980435

Leadership and Creativity in Higher Education

ERIC Educational Resources Information Center

Zacher, Hannes; Johnson, Emily

2015-01-01

Leadership and creativity have received increasing attention from researchers in the field of higher education; however, empirical studies investigating these topics simultaneously are rare. In this study, the authors examined relationships between PhD students' perceptions of their advising professors' passive-avoidant, transactional, and…

Extensibility of the hamstrings is best explained by mechanical components of muscle contraction, not behavioral measures in individuals with chronic low back pain.

PubMed

Marshall, Paul W M; Mannion, Jamie; Murphy, Bernadette A

2009-08-01

To examine the relationship between hamstring extensibility by use of the instrumented straight leg raise; mechanical components of muscle contraction, including muscle recruitment, passive torque measures of tissue stiffness, and eccentric strength; and self-reported measures of pain and disability. Cross-sectional study. University laboratory. Twenty-one individuals with chronic nonspecific axial lower back pain and 15 healthy control subjects. Instrumented straight leg raise, concentric and eccentric hamstring strength, self-reported measures of pain, disability, fear avoidance, general health and well-being Objective measures included hamstring extensibility, hamstring muscle stiffness, absolute and relative concentric/eccentric strength, concentric/eccentric strength ratios. Self-reported measures included Oswestry disability index, visual analog pain scale, fear avoidance beliefs, and general health and well being. Patients with lower back pain had lower range of motion, greater changes in muscle stiffness, and impaired concentric-to-eccentric strength levels. Stepwise regression identified measures of stiffness as significantly predicting hamstring extensibility (adjusted r(2) = 0.58, F = 23.76, P < .001). Self-reported measures were not associated with extensibility. Gender differences were noted for passive stiffness and absolute strength. For women, later onset of the medial hamstrings also was associated with greater hamstring extensibility. Decreased extensibility of the hamstrings was associated with increased passive stiffness during the common range of motion (20 to 50 degrees ). Impaired stretch tolerance is associated with actual mechanical restriction, not behavioral measures indicating increased pain or fear-avoidant behavior. With no relationship to actual disability and contradictory findings in the literature for the relationship of the hamstrings to the mechanics of the low back, it is unclear whether decreased hamstring extensibility should be targeted in rehabilitation programs for axial lower back pain.

[Effect of diisobutyl phthalate on learning and memory behavior and apoptosis of hippocampus cells in mice].

PubMed

Ma, Ning; Liu, Shan; Gao, Peng; Cao, Pei; Xu, Haibin

2013-01-01

To give the original research of diisobutyl phthalate (DiBP) on learning and memory behavior, determine whether it can through blood-brain barrier and effect apoptosis of hippocampus cells in mice. Accommodating 60 Kunming mice to the animal house for 3 days, then dividing the mice into 5 groups according to their weights. That is, one control group and four experimental groups (I group, 50 mg/kg BW. II group, 250mg/kg BW. III group, 500 mg/kg BW. IV group, 1000 mg/kg BW). The mice were fed with the corn oil in control group, and the other groups were fed with the related dose of diisobutyl phthalate mixture by gavages last for 8 weeks. At the end of experimental time, passive avoidance response was examined, then all of mice were killed, and choosed the brain tissues to test the DiBP content and apoptosis rate of hippocampal cells and hippocampal ultrastructural alterations on electron microscopy. In the passive avoidance response test, the exposed animals of IV group showed learning impairment as compared to unexposed mice (P < 0.05). DiBP was detected in III group and IV group, the mean content of them were (1.27 +/- 0.56) and (1.96 +/- 0.42) microg/g. The apoptosis rate of hippocampal cells (IV group vs control group) increase significantly (P < 0.05). Hippocampal ultrastructural were damaged in all dose-groups. As a result, in the experiments, exposure to DiBP could exert passive avoidance neurobehavioral effects. DiBP could through blood-brain barrier after oral intake, and disordered the way of apoptosis of hippocampal cells, and morphologic change of mitochondria mybe is the main reason of changes of neuron apoptosis.

Acupuncture inhibits the decrease in brain catecholamine contents and the impairment of passive avoidance task in ovariectomized mice.

PubMed

Toriizuka, K; Okumura, M; Iijima, K; Haruyama, K; Cyong, J C

1999-01-01

The effects of acupuncture on the disorders elicited by abnormalities of endocrine system were investigated in ovariectomized mice. Female mice (strain; C57BL/6) were ovariectomized (OVX) and acupuncture points, Shenshu ([Japanese pictograph see text] : BL23) on both side of the back were continuously stimulated by subcutaneous needles for 20 days. After completion of experimental sessions, animals were sacrificed and specific brain regions were assayed for catecholamine contents by high performance liquid chromatography with electro chemical detector (ECD-HPLC). The mitogenic activities of splenic lymphocytes were measured by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTS) assay and alkaline phosphatase (ALP) assay. Furthermore, the effects of needle stimulation on learning and memory ability were studied by the step-through type passive avoidance test. Norepinephrine and dopamine contents in the frontoparietal cerebral cortex, ventral hippocampus and olfactory bulb were decreased in the OVX group, and both MTS activity and ALP activity were decreased 20 days after ovariectomy. The mean latent period was also shortened in the passive avoidance test in the OVX group. However, applying needle stimulation increased norepinephrine and dopamine contents in the brain regions, and enhanced mitogenic activities of splenic lymphocytes. The stimulation also improved memory-related behavior. It was concluded from this study that after mice were stimulated by subcutaneous needle insertion, overall changes were observed in central nervous system (including retention of memory) and immune functions. The study suggests that acupuncture improves the memory loss and decrease of immune responses accompanying aging and/or menopause, and the that it may have an important role in medical care for the elderly.

Summary of avoidable cancers in the Nordic countries.

PubMed

Olsen, J H; Andersen, A; Dreyer, L; Pukkala, E; Tryggvadottir, L; Gerhardsson de Verdier, M; Winther, J F

1997-01-01

An overview is given of the most important known causes of cancer in the five Nordic countries and the resulting number of cancers that are potentially avoidable. The main causes include active and passive smoking, alcohol consumption, exposure to asbestos and other occupational carcinogens, solar and ionizing radiation, obesity, human papillomavirus infection in the female genital tract and infection with Helicobacter pylori. The organs most commonly affected are those of the respiratory system, the upper digestive tract and stomach, skin, the lower urinary tract and the uterine cervix. Annually, more than 18,000 cancers in men and 11,000 in women in the Nordic populations could be avoided by eliminating exposure to known carcinogens which is equivalent to 33% and 20% of all cancers arising in men and women, respectively, around the year 2000. Smoking habits account for a little more than half of these avoidable cases. Estimates of avoidable cancers are given for each Nordic country, separately.

THE EFFECT OF INTIMACY AND STATUS DISCREPANCY ON SALIENT AND NON-SALIENT CONFLICT STRATEGIES OF JAPANESE.

PubMed

Nakatsugawa, Satomi; Takai, Jiro

2015-10-01

It has been claimed that Japanese people prefer passive forms of conflict strategies to preserve interpersonal harmony. This study aimed to identify some conditions in which such passive strategies are used. The effects of target intimacy and status discrepancy on the intent and use of salient and non-salient conflict strategies were examined, along with respondent sex differences. Questionnaires were collected from 205 Japanese university students. Results indicated that women were more likely to have non-salient intents than men and that intimacy affected considerateness intent but not avoidance intent. Active non-salient strategy was affected by status while passive non-salient strategy was affected by intimacy. Overall, target characteristics proved to be a strong factor in the intents and strategies employed in conflict situations of Japanese.

Instant loading with intraoral welding technique and PRAMA implants: a new prosthetic approach.

PubMed

Celletti, R; Fanali, S; Laici, C U; Santori, C; Pignatelli, P; Sinjari, B

2017-01-01

When splinting multiple implants passive fit of the framework should be achieved to avoid excessive force distribution on the implants. Recently, a protocol was suggested for immediate loading of multiple implants by welding a titanium bar to implant abutments directly in the oral cavity so as to create a customized, precise and passive metal-reinforced provisional restoration. The intraoral welding technique subsequently proves to be a successful option in the full-arch immediate restorations of the mandible and maxilla. The aim of this article is to present a case report in which a new prosthetic approach, using trans-mucosal implants, is described. Dental implants are instantly loaded with a provisional prosthesis supported by an intraoral welded titanium framework to obtain a precise passive fit of the immediate loaded prosthesis.

Reversible inactivation of interpeduncular nucleus impairs memory consolidation and retrieval but not learning in rats: A behavioral and molecular study.

PubMed

Khatami, Leila; Khodagholi, Fariba; Motamedi, Fereshteh

2018-04-16

The Interpedundular nucleus (IPN) is a small midbrain structure located deeply between the two cerebral peduncles. The strategic placement of this nucleus makes it a possible relay between structures involved in the modulation of hippocampal theta rhythm activity. In this study we aimed to investigate how reversible inactivation of IPN could affect the acquisition, consolidation and retrieval phases of memory in passive avoidance (PA) and Morris water maze (MWM) tasks. To support our data, molecular studies were performed in order to detect possible changes in the expression of proteins related to learning and memory in the hippocampus. To address this issue rats' IPN was reversibly inactivated by microinjection of lidocaine hydrochloride (4%). After the behavioral studies, the phosphorylation of CREB and P70, and c-fos expression levels in the hippocampus were determined using western blotting and immunohistochemistry respectively. Our results in the PA and MWM tasks showed that IPN reversible inactivation could impair immediate post training consolidation and retrieval while it had no effect on the acquisition phase. In addition, there was a deficit in the retention of the MWM working memory. Our data showed the ratio of pCREB/CREB, pP70/P70 and c-fos expression in the hippocampus significantly decreased after IPN reversible inactivation. Collectively, the results show that behaviorally defined changes could be due to what happens molecularly in the hippocampus after IPN reversible inactivation. It is concluded that IPN not only makes part of a network involved in the modulation of hippocampal theta rhythm activity, but also is actively engaged in hippocampal memory formation. Copyright © 2018 Elsevier B.V. All rights reserved.

Scopolamine-Induced Memory Impairment Is Alleviated by Xanthotoxin: Role of Acetylcholinesterase and Oxidative Stress Processes.

PubMed

Skalicka-Wozniak, Krystyna; Budzynska, Barbara; Biala, Grazyna; Boguszewska-Czubara, Anna

2018-05-16

Xanthotoxin, popularly occurring furanocoumarin, which can be found in plants from the Apiaceae family, was isolated from fruits of Pastinaca sativa L. by mean of high-performance countercurrent chromatography, and its effects on the scopolamine-induced cognitive deficits in male Swiss mice using the passive avoidance (PA) test were evaluated. To measure the acquisition of memory processes, xanthotoxin (1, 2.5, 5 mg/kg) was administered 30 min before PA test and scopolamine was administered 10 min after xanthotoxin. To measure the consolidation of memory processes, xanthotoxin (1 and 2.5 mg/kg) was injected immediately after removing the mouse from the apparatus and 10 min after scopolamine was administered. In subchronic experiments, mice were injected with xanthotoxin (1 mg/kg) or saline, 6 days, twice daily. At 24 h after the last injection of the drugs, the hippocampus and the prefrontal cortex were removed for biochemical assays. The results demonstrated that either single (2.5 and 5 mg/kg) or repeatable (1 mg/kg) administration of xanthotoxin significantly increased index of latency (IL) in both acquisition and consolidation of memory processes, showing some procognitive effects. The behavioral tests also showed that an acute (2.5 mg/kg) and subchronic (1 mg/kg) administration of xanthotoxin prevent memory impairment induced by injection of scopolamine (1 mg/kg). Observed effects could be due to the inhibition of acetylcholinesterase activities and amelioration of oxidative stress processes in the hippocampus and the prefrontal cortex. It was suggested that xanthotoxin could show neuroprotective effect in scopolamine-induced cognitive impairment connected to cholinergic neurotransmission and oxidative stress in the brain structures.

Interrelationship of Personality Disorders: Theoretical Formulations and Anecdotal Evidence.

ERIC Educational Resources Information Center

Vincent, Ken R.

1987-01-01

Attempts to define interrelationship of personality disorders. Discusses relationships between and among three major groupings of Diagnostic and Statistical Manual of Mental Disorders. Suggests that passive aggressive, avoidant, and borderline personality disorders serve as bridges between these groupings. Discusses placement within groupings with…

Pre-electroconvulsive shock administration of calcium channel blockers reduces retrograde amnesia induced by ECS.

PubMed

Sushma, M; Sudha, S; Guido, S

2004-11-01

Effect of pre-electroconvulsive shock (ECS) administration of calcium channel blockers (CCBs) like verapamil, diltiazem, nifedipine, nimodipine, flunarizine and cinnarizine on retrograde amnesia induced by ECS was examined using passive avoidance paradigm in rats. The groups (Gr 1-7) of adult, male Wistar rats received true ECS with CCBs (5mg/kg; i.p) or vehicle (10 ml/kg; ip) and other groups (Gr 8-14) received sham ECS with CCBs (5mg/kg; i.p) or vehicle (10 ml/kg; i.p). The anti-amnestic activity of CCBs were evaluated using the passive avoidance paradigm in rats. Results showed that, the baseline latencies for all the groups did not differ significantly. Rats receiving true ECS produced significantly lower latencies. There was increase in the post ECS step through latencies of the rats administered CCBs before ECS. Therefore, pre-ECS administration of calcium channel blockers might reduce retrograde amnesia produced by ECS without altering seizure duration.

Prevalence of personality disorders in patients with chronic migraine.

PubMed

Kayhan, Fatih; Ilik, Faik

2016-07-01

The present study aimed to investigate the prevalence of personality disorders (PDs) in patients with chronic migraine (CM). This study included 105 CM patients who were diagnosed according to the criteria of the International Headache Society (IHS) and 100 healthy volunteers. PDs were diagnosed with the Structured Clinical Interview for DSM, Revised Third Edition Personality Disorders, and pain severity and level of disability were assessed with the Migraine Disability Assessment (MIDAS) test. Of the 105 CM patients, 85 (81%) had at least one PD. PDs were more prevalent in the patient group than in the healthy control group, and the most common PDs were obsessive-compulsive (n=53, 50.5%), dependent (n=20, 19%), avoidant (n=20, 19%), and passive-aggressive (n=14, 13.3%) PDs. The MIDAS scores of the CM patients with PDs were higher than those of the CM patients without PDs. PDs, particularly obsessive-compulsive, dependent, avoidant, and passive-aggressive PDs, were frequently observed in CM patients in the present study. Copyright © 2016 Elsevier Inc. All rights reserved.

[Effect of agonist and antagonist of 5-HT(1A) receptors on learning in female rats during ovarian cycle].

PubMed

Fedotova, Iu O; Ordian, N E

2010-01-01

The involvement of 5-HT(1A) receptors in learning/memory processes during ovary cycle was assessed in the adult female rats. 8-OH-DPAT (0.05 mg/kg, s.c.), 5-HT(1A) receptor agonist and NAN-190 (0.1 mg/kg, i.p.), 5-HT(1A) receptor antagonist were injected chronically to adult female rats. Learning of these animals was assessed in different models: passive avoidance performance and Morris water maze. Chronic NAN-190 administration to females resulted in the appearance of the passive avoidance performance in proestrous and estrous, as distinct from the control animals, but failed to change the dynamics of spatial learning in Morris water maze. Chronic 8-OH-DPAT administration similarly impaired non-spatial and spatial learning in females during all phases of ovary cycle. The results of the study suggest modulating role of 5-HT(1A) receptors in learning/memory processes during ovary cycle in the adult female rats.

Furoxans (Oxadiazole-4 N-oxides) with Attenuated Reactivity are Neuroprotective, Cross the Blood Brain Barrier, and Improve Passive Avoidance Memory.

PubMed

Horton, Austin; Nash, Kevin; Tackie-Yarboi, Ethel; Kostrevski, Alexander; Novak, Adam; Raghavan, Aparna; Tulsulkar, Jatin; Alhadidi, Qasim; Wamer, Nathan; Langenderfer, Bryn; Royster, Kalee; Ducharme, Maxwell; Hagood, Katelyn; Post, Megan; Shah, Zahoor A; Schiefer, Isaac T

2018-05-07

Nitric oxide (NO) mimetics and other agents capable of enhancing NO/cGMP signaling have demonstrated efficacy as potential therapies for Alzheimer's disease. A group of thiol-dependent NO mimetics known as furoxans may be designed to exhibit attenuated reactivity to provide slow onset NO effects. The present study describes the design, synthesis, and evaluation of a furoxan library resulting in the identification of a prototype furoxan, 5a, which was profiled for use in the central nervous system. Furoxan 5a demonstrated negligible reactivity toward generic cellular thiols under physiological conditions. Nonetheless, cGMP-dependent neuroprotection was observed, and 5a (20 mg/kg) reversed cholinergic memory deficits in a mouse model of passive avoidance fear memory. Importantly, 5a can be prepared as a pharmaceutically acceptable salt and is observed in the brain 12 h after oral administration, suggesting potential for daily dosing and excellent metabolic stability. Continued investigation into furoxans as attenuated NO mimetics for the CNS is warranted.

Neuroprotective and cognitive enhancing activity of the fermented Bozhougyiqi-Tang

PubMed Central

Weon, Jin Bae; Lee, Bohyoung; Yun, Bo-Ra; Lee, Jiwoo; Ma, Jin Y; Ma, Choong Je

2014-01-01

Background: Alzheimer's disease is a neurodegenerative disease related to memory impairments and neuronal cell death. Bozhougyiqi-Tang (BZYQT), a traditional herbal medicine, has been therapeutically used for the treatment of pulmonary tuberculosis. Objective: The aim of this study is to evaluated the neuroprotective effect of the fermented BZYQT and compared with unfermented BZYQT in HT22 cells by MTT assay and tested the beneficial effect on memory impairments induced by scopolamine (1 mg/kg, i.p.) using the passive avoidance and Morris water maze tests. Results: Compared with unfermented BZYQT, the neuroprotective effect of fermented BZYQT on glutamate induced neurotoxicity in HT22 cells increased at a concentration of 100 μg/mL. Fermented BZYQT increased the step-through latency of the passive avoidance response. Furthermore, in Morris water maze test for evaluation of spatial learning and memory, escape latency time was significantly reduced by fermented BZYQT. Conclusion: These results suggest that the fermentation process of BZYQT led to improve neuroprotective and cognitive enhancing effect. PMID:24991099

Effects of activation and blockade of dopamine receptors on the extinction of a passive avoidance reaction in mice with a depressive-like state.

PubMed

Dubrovina, N I; Zinov'eva, D V

2010-01-01

Learning and extinction of a conditioned passive avoidance reaction resulting from neuropharmacological actions on dopamine D(1) and D(2) receptors were demonstrated to be specific in intact mice and in mice with a depressive-like state. Learning was degraded only after administration of the D(2) receptor antagonist sulpiride and was independent of the initial functional state of the mice. In intact mice, activation of D(2) receptors with quinpirole led to a deficit of extinction, consisting of a reduction in the ability to acquire new inhibitory learning in conditions associated with the disappearance of the expected punishment. In mice with the "behavioral despair" reaction, characterized by delayed extinction, activation of D(1) receptors with SKF38393 normalized this process, while the D(2) agonist was ineffective. A positive effect consisting of accelerated extinction of the memory of fear of the dark ("dangerous") sector of the experimental chamber was also seen on blockade of both types of dopamine receptor.

Ameliorating effect of new constituents from the hooks of Uncaria rhynchophylla on scopolamine-induced memory impairment.

PubMed

Shin, Suk-Chul; Lee, Dong-Ung

2013-07-01

To study the chemical constituents and their anti-amnesic effect from the hooks of Uncaria rhynchophylla. The isolation of compounds was performed by chromatographic techniques and their structures were identified on the basis of spectral analysis. Their ameliorating effects on scopolamine-induced memory impairment in vivo using a Morris water-maze task and passive avoidance task system were evaluated. Activity-guided fractionation of the total extracts resulted in the isolation of four constituents, trans-anethole (1), p-anisaldehyde (2), estragole (3), and 3-oxo-olean-12-en-28-oic acid (4), which were found for the first time from this plant. Compound 1 exhibited a better memory enhancing effect than tacrine, a positive agent, at the same dose in the passive avoidance test and a similar property in the water-maze test, and its action may be mediated, in part, by the acetylcholine enhancing cholinergic nervous system. Copyright © 2013 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

Passive in-vehicle driver breath alcohol detection using advanced sensor signal acquisition and fusion.

PubMed

Ljungblad, Jonas; Hök, Bertil; Allalou, Amin; Pettersson, Håkan

2017-05-29

The research objective of the present investigation is to demonstrate the present status of passive in-vehicle driver breath alcohol detection and highlight the necessary conditions for large-scale implementation of such a system. Completely passive detection has remained a challenge mainly because of the requirements on signal resolution combined with the constraints of vehicle integration. The work is part of the Driver Alcohol Detection System for Safety (DADSS) program aiming at massive deployment of alcohol sensing systems that could potentially save thousands of American lives annually. The work reported here builds on earlier investigations, in which it has been shown that detection of alcohol vapor in the proximity of a human subject may be traced to that subject by means of simultaneous recording of carbon dioxide (CO 2 ) at the same location. Sensors based on infrared spectroscopy were developed to detect and quantify low concentrations of alcohol and CO 2 . In the present investigation, alcohol and CO 2 were recorded at various locations in a vehicle cabin while human subjects were performing normal in-step procedures and driving preparations. A video camera directed to the driver position was recording images of the driver's upper body parts, including the face, and the images were analyzed with respect to features of significance to the breathing behavior and breath detection, such as mouth opening and head direction. Improvement of the sensor system with respect to signal resolution including algorithm and software development, and fusion of the sensor and camera signals was successfully implemented and tested before starting the human study. In addition, experimental tests and simulations were performed with the purpose of connecting human subject data with repeatable experimental conditions. The results include occurrence statistics of detected breaths by signal peaks of CO 2 and alcohol. From the statistical data, the accuracy of breath alcohol estimation and timing related to initial driver routines (door opening, taking a seat, door closure, buckling up, etc.) can be estimated. The investigation confirmed the feasibility of passive driver breath alcohol detection using our present system. Trade-offs between timing and sensor signal resolution requirements will become critical. Further improvement of sensor resolution and system ruggedness is required before the results can be industrialized. It is concluded that a further important step toward completely passive detection of driver breath alcohol has been taken. If required, the sniffer function with alcohol detection capability can be combined with a subsequent highly accurate breath test to confirm the driver's legal status using the same sensor device. The study is relevant to crash avoidance, in particular driver monitoring systems and driver-vehicle interface design.

Avoiding "culture rejection" in healthcare mergers and acquisitions: how New Heights Community Health Centres and York Community Services minimized the culture risk when forming Unison Health and Community Services.

PubMed

Chan, Jeff

2013-01-01

Among the requirements for a successful merger or acquisition are strategic rationale, rigorous due diligence, the right price and revenue and cost synergies. However, bridging the culture gap between organizations is frequently overlooked. The leaders of New Heights Community Health Centres and York Community Services explicitly considered culture in their merger to form Unison Health and Community Services, and they used employee engagement surveys to assess culture in their merger planning and post-merger integration. How Unison Health leaders avoided the risk of culture rejection to achieve a successful merger, and the lessons learned from their experience, is the focus of this article.

Reactive Collision Avoidance Algorithm

NASA Technical Reports Server (NTRS)

Scharf, Daniel; Acikmese, Behcet; Ploen, Scott; Hadaegh, Fred

2010-01-01

The reactive collision avoidance (RCA) algorithm allows a spacecraft to find a fuel-optimal trajectory for avoiding an arbitrary number of colliding spacecraft in real time while accounting for acceleration limits. In addition to spacecraft, the technology can be used for vehicles that can accelerate in any direction, such as helicopters and submersibles. In contrast to existing, passive algorithms that simultaneously design trajectories for a cluster of vehicles working to achieve a common goal, RCA is implemented onboard spacecraft only when an imminent collision is detected, and then plans a collision avoidance maneuver for only that host vehicle, thus preventing a collision in an off-nominal situation for which passive algorithms cannot. An example scenario for such a situation might be when a spacecraft in the cluster is approaching another one, but enters safe mode and begins to drift. Functionally, the RCA detects colliding spacecraft, plans an evasion trajectory by solving the Evasion Trajectory Problem (ETP), and then recovers after the collision is avoided. A direct optimization approach was used to develop the algorithm so it can run in real time. In this innovation, a parameterized class of avoidance trajectories is specified, and then the optimal trajectory is found by searching over the parameters. The class of trajectories is selected as bang-off-bang as motivated by optimal control theory. That is, an avoiding spacecraft first applies full acceleration in a constant direction, then coasts, and finally applies full acceleration to stop. The parameter optimization problem can be solved offline and stored as a look-up table of values. Using a look-up table allows the algorithm to run in real time. Given a colliding spacecraft, the properties of the collision geometry serve as indices of the look-up table that gives the optimal trajectory. For multiple colliding spacecraft, the set of trajectories that avoid all spacecraft is rapidly searched on-line. The optimal avoidance trajectory is implemented as a receding-horizon model predictive control law. Therefore, at each time step, the optimal avoidance trajectory is found and the first time step of its acceleration is applied. At the next time step of the control computer, the problem is re-solved and the new first time step is again applied. This continual updating allows the RCA algorithm to adapt to a colliding spacecraft that is making erratic course changes.

Affordability Constraints in Major Defense Acquisitions

DTIC Science & Technology

2016-11-01

Fence Inc 1 30-May-2014 4-Oct-2012 4-Nov-2015 32 SSC 5-Jul-2012 33 VH-92A (VXX) 5-Apr-2013 17-Apr-2014 34 FAB -T CPT 26-Oct...Development EPAWSS Eagle Passive/Active Warning and Survivability System EPP Extended Planning Period EPS Enhanced Polar System FAB -T CPT Family of

Fear of movement, passive coping, manual handling, and severe or radiating pain increase the likelihood of sick leave due to low back pain.

PubMed

Dawson, Anna P; Schluter, Philip J; Hodges, Paul W; Stewart, Simon; Turner, Catherine

2011-07-01

Sick leave due to low back pain (LBP-SL) is costly and compromises workforce productivity. The fear-avoidance model asserts that maladaptive pain-related cognitions lead to avoidance and disuse, which can perpetuate ongoing pain. Staying home from work is an avoidant behavior, and hence pain-related psychological features may help explain LBP-SL. We examined the relative contribution of pain catastrophizing, fear of movement, and pain coping (active and passive) in LBP-SL in addition to pain characteristics and other psychosocial, occupational, general health, and demographic factors. Two-way interactions between age and gender and candidate exposures were also considered. Our sample comprised 2164 working nurses and midwives with low back pain in the preceding year. Binary logistic regression was performed on cross-sectional data by manual backward stepwise elimination of nonsignificant terms to generate a parsimonious multivariable model. From an extensive array of exposures assessed, fear of movement (women, odds ratio [OR]=1.05, 95% confidence interval [CI] 1.02-1.08; men, OR=1.17, 95% CI 1.05-1.29), passive coping (OR=1.07, 95% CI 1.04-1.11), pain severity (OR=1.61, 95% CI 1.50-1.72), pain radiation (women, OR=1.45, 95% CI 1.10-1.92; men, OR=4.13, 95% CI 2.15-7.95), and manual handling frequency (OR=1.03, 95% CI 1.01-1.05) increased the likelihood of LBP-SL in the preceding 12 months. Administrators and managers were less likely to report LBP-SL (OR=0.44, 95% CI 0.27-0.71), and age had a protective effect in individuals in a married or de facto relationship (OR=0.97, 95% CI 0.95-0.98). In summary, fear of movement, passive coping, frequent manual handling, and severe or radiating pain increase the likelihood of LBP-SL. Gender-specific responses to pain radiation and fear of movement are evident. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

26 CFR 1.269-4 - Power of district director to allocate deduction, credit, or allowance in part.

Code of Federal Regulations, 2011 CFR

2011-04-01

... result in the evasion or avoidance of Federal income tax for which the acquisition was made. The district..., DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Items Not Deductible... section 269(a), but only to such extent as he determines will not result in the evasion or avoidance of...

Context conditioning and behavioral avoidance in a virtual reality environment: effect of predictability.

PubMed

Grillon, Christian; Baas, Johanna M P; Cornwell, Brian; Johnson, Linda

2006-10-01

Sustained anxiety can be modeled using context conditioning, which can be studied in a virtual reality environment. Unpredictable stressors increase context conditioning in animals. This study examined context conditioning to predictable and unpredictable shocks in humans using behavioral avoidance, potentiated startle, and subjective reports of anxiety. Subjects were guided through three virtual rooms (no-shock, predictable, unpredictable contexts). Eight-sec duration colored lights served as conditioned stimuli (CS). During acquisition, no shock was administered in the no-shock context. Shocks were paired with the CS in the predictable context and were administered randomly in the unpredictable context. No shock was administered during extinction. Startle stimuli were delivered during CS and between CS to assess cued and context conditioning, respectively. To assess avoidance, subjects freely navigated into two of the three contexts to retrieve money. Startle between CS was potentiated in the unpredictable context compared to the two other contexts. Following acquisition, subjects showed a strong preference for the no-shock context and avoidance of the unpredictable context. Consistent with animal data, context conditioning is increased by unpredictability. These data support virtual reality as a tool to extend research on physiological and behavioral signs of fear and anxiety in humans.

Determination of trichloroanisole and trichlorophenol in wineries' ambient air by passive sampling and thermal desorption-gas chromatography coupled to tandem mass spectrometry.

PubMed

Camino-Sánchez, F J; Bermúdez-Peinado, R; Zafra-Gómez, A; Ruíz-García, J; Vílchez-Quero, J L

2015-02-06

The present paper describes the calibration of selected passive samplers used in the quantitation of trichlorophenol and trichloroanisole in wineries' ambient air, by calculating the corresponding sampling rates. The method is based on passive sampling with sorbent tubes and involves thermal desorption-gas chromatography-triple quadrupole mass spectrometry analysis. Three commercially available sorbents were tested using sampling cartridges with a radial design instead of axial ones. The best results were found for Tenax TA™. Sampling rates (R-values) for the selected sorbents were determined. Passive sampling was also used for accurately determining the amount of compounds present in the air. Adequate correlation coefficients between the mass of the target analytes and exposure time were obtained. The proposed validated method is a useful tool for the early detection of trichloroanisole and its precursor trichlorophenol in wineries' ambient air while avoiding contamination of wine or winery facilities. Copyright © 2015 Elsevier B.V. All rights reserved.

[Euthanasia and the doctrine of double effect].

PubMed

Klein, Martin

2005-01-01

Direct active euthanasia is prohibited in most countries while passive and indirect is not. However, many arguments against the legalization of voluntary active euthanasia are flawed. Ethical differences between active and passive or indirect euthanasia are difficult to maintain especially when the passivity of the actor causes death. The crucial point is not activity or passivity but respect for the autonomy of individual human beings. In particular there appears to be little ethical difference between active and indirect euthanasia. Indirect euthanasia has often been justified by the principle of double effect, which traces back to Thomas Aquinas. But resorting to this rule contains a logical fallacy. The principle of double effect does not allow foreseen and unwanted adverse effects of an action to occur when they are avoidable. In terminal sedation, an example for indirect euthanasia, hypoxemia and dehydration can easily be prevented by respirator therapy and fluid administration. Therefore the rule of double effect is not applicable. Indirect and direct active euthanasia cannot be ethically distinguished by resorting to the principle of double effect.

A low timing jitter picosecond microchip laser pumped by pulsed LD

NASA Astrophysics Data System (ADS)

Wang, Sha; Wang, Yan-biao; Feng, Guoying; Zhou, Shou-huan

2016-07-01

SESAM passively Q-switched microchip laser is a very promising instrument to replace mode locked lasers to obtain picosecond pulses. The biggest drawback of a passively Q-switched microchip laser is its un-avoided large timing jitter, especially when the pump intensity is low, i.e. at low laser repetition rate range. In order to obtain a low timing jitter passively Q-switched picosecond microchip laser in the whole laser repetition rate range, a 1000 kHz pulsed narrow bandwidth Fiber Bragg Grating (FBG) stablized laser diode was used as the pump source. By tuning the pump intensity, we could control the output laser frequency. In this way, we achieved a very low timing jitter passively Q-switched picosecond laser at 2.13 mW, 111.1 kHz. The relative timing jitter was only 0.0315%, which was around 100 times smaller compared with a cw LD pumped microchip working at hundred kilohertz repetition rate frequency range.

Corrosion control when using passively treated abandoned mine drainage as alternative makeup water for cooling systems.

PubMed

Hsieh, Ming-Kai; Chien, Shih-Hsiang; Li, Heng; Monnell, Jason D; Dzombak, David A; Vidic, Radisav D

2011-09-01

Passively treated abandoned mine drainage (AMD) is a promising alternative to fresh water as power plant cooling water system makeup water in mining regions where such water is abundant. Passive treatment and reuse of AMD can avoid the contamination of surface water caused by discharge of abandoned mine water, which typically is acidic and contains high concentrations of metals, especially iron. The purpose of this study was to evaluate the feasibility of reusing passively treated AMD in cooling systems with respect to corrosion control through laboratory experiments and pilot-scale field testing. The results showed that, with the addition of the inhibitor mixture orthophosphate and tolyltriazole, mild steel and copper corrosion rates were reduced to acceptable levels (< 0.127 mm/y and < 0.0076 mm/y, respectively). Aluminum had pitting corrosion problems in every condition tested, while cupronickel showed that, even in the absence of any inhibitor and in the presence of the biocide monochloramine, its corrosion rate was still very low (0.018 mm/y).

Exercise Science Principles and the Vocal Warm-up: Implications for Singing Voice Pedagogy.

PubMed

Hoch, Matthew; Sandage, Mary J

2018-01-01

Principles from exercise science literature were applied to singing warm-up pedagogy as a method for examining parallels between athletic and voice training. Analysis of the use of exercise principles in vocal warm-up should illuminate aspects of voice training that may be further developed in the future. A selected canon of standard voice pedagogy texts and well-regarded warm-up methods were evaluated for use of exercise science principles for skill acquisition and fatigue resistance. Exercises were then categorized according to whether they were used for the purpose of skill acquisition (specificity), training up to tasks (overload), or detraining (reversibility). A preliminary review of well-established voice pedagogy programs reveals a strong bias toward the skill acquisition aspects of vocal warm-up, with little commentary on the fatigue management aspects. Further, the small number of vocalises examined that are not skill-acquisition oriented fall into a third "habilitative" category that likewise does not relate to overload but may play a role in offsetting reversibility. Although a systematic pedagogy for skill acquisition has emerged in the literature and practice of voice pedagogy, a parallel pedagogy for fatigue management has yet to be established. Identification of a systematic pedagogy for training up to specific singing genres and development of a singing maintenance program to avoid detraining may help the singer avoid injury. Copyright © 2018 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Data acquisition system for segmented reactor antineutrino detector

NASA Astrophysics Data System (ADS)

Hons, Z.; Vlášek, J.

2017-01-01

This paper describes the data acquisition system used for data readout from the PMT channels of a segmented detector of reactor antineutrinos with active shielding. Theoretical approach to the data acquisition is described and two possible solutions using QDCs and digitizers are discussed. Also described are the results of the DAQ performance during routine data taking operation of DANSS. DANSS (Detector of the reactor AntiNeutrino based on Solid Scintillator) is a project aiming to measure a spectrum of reactor antineutrinos using inverse beta decay (IBD) in a plastic scintillator. The detector is located close to an industrial nuclear reactor core and is covered by passive and active shielding. It is expected to have about 15000 IBD interactions per day. Light from the detector is sensed by PMT and SiPM.

Attenuation of scopolamine-induced and age-associated memory impairments by the sigma and 5-hydroxytryptamine(1A) receptor agonist OPC-14523 (1-[3-[4-(3-chlorophenyl)-1-piperazinyl]propyl]-5-methoxy-3,4-dihydro-2[1H]-quinolinone monomethanesulfonate).

PubMed

Tottori, Katsura; Nakai, Masami; Uwahodo, Yasufumi; Miwa, Takashi; Yamada, Sakiko; Oshiro, Yasuo; Kikuchi, Tetsuro; Altar, C Anthony

2002-04-01

Sigma and 5-HT(1A) receptor stimulation can increase acetylcholine (ACh) release in the brain. Because ACh release facilitates learning and memory, we evaluated the degree to which OPC-14523 (1-[3-[4-(3-chlorophenyl)-1-piperazinyl]propyl]-5-methoxy-3,4-dihydro-2[1H]-quinolinone monomethane sulfonate), a novel sigma and 5-HT(1A) receptor agonist, can augment ACh release and improve learning impairments in rats due to cholinergic- or age-related deficits. Single oral administration of OPC-14523 improved scopolamine-induced learning impairments in the passive-avoidance task and memory impairment in the Morris water maze. The chronic oral administration of OPC-14523 attenuated age-associated impairments of learning acquisition in the water maze and in the conditioned active-avoidance response test. OPC-14523 did not alter basal locomotion or inhibit acetylcholinesterase (AChE) activity at concentrations up to 100 microM and, unlike AChE inhibitors, did not cause peripheral cholinomimetic responses. ACh release in the dorsal hippocampus of freely moving rats increased after oral delivery of OPC-14523 and after local delivery of OPC-14523 into the hippocampus. The increases in hippocampal ACh release were blocked by the sigma receptor antagonist NE-100 (N,N-dipropyl-2-[4-methoxy-3-(2-phenylethoxy)-phenyl]-ethylamine). Thus, OPC-14523 improves scopolamine-induced and age-associated learning and memory impairments by enhancing ACh release, due to a stimulation of sigma and probably 5-HT(1A) receptors. Combined sigma/5-HT(1A) receptor agonism may be a novel approach to ameliorate cognitive disorders associated with age-associated cholinergic deficits.

Behavioral and neurochemical characterization of mice deficient in the phosphodiesterase-1B (PDE1B) enzyme.

PubMed

Siuciak, J A; McCarthy, S A; Chapin, D S; Reed, T M; Vorhees, C V; Repaske, D R

2007-07-01

PDE1B is a calcium-dependent cyclic nucleotide phosphodiesterase that is highly expressed in the striatum. In order to investigate the physiological role of PDE1B in the central nervous system, PDE1B knockout mice (C57BL/6N background) were assessed in behavioral tests and their brains were assayed for monoamine content. In a variety of well-characterized behavioral tasks, including the elevated plus maze (anxiety-like behavior), forced swim test (depression-like behavior), hot plate (nociception) and two cognition models (passive avoidance and acquisition of conditioned avoidance responding), PDE1B knockout mice performed similarly to wild-type mice. PDE1B knockout mice showed increased baseline exploratory activity when compared to wild-type mice. When challenged with amphetamine (AMPH) and methamphetamine (METH), male and female PDE1B knockout mice showed an exaggerated locomotor response. Male PDE1B knockout mice also showed increased locomotor responses to higher doses of phencyclidine (PCP) and MK-801; however, this effect was not consistently observed in female knockout mice. In the striatum, increased dopamine turnover (DOPAC/DA and HVA/DA ratios) was found in both male and female PDE1B knockout mice. Striatal serotonin (5-HT) levels were also decreased in PDE1B knockout mice, although levels of the metabolite, 5HIAA, were unchanged. The present studies demonstrate increased striatal dopamine turnover in PDE1B knockout mice associated with increased baseline motor activity and an exaggerated locomotor response to dopaminergic stimulants such as methamphetamine and amphetamine. These data further support a role for PDE1B in striatal function.

[Investigation on remote measurement of air pollution by a method of infrared passive scanning imaging].

PubMed

Jiao, Yang; Xu, Liang; Gao, Min-Guang; Feng, Ming-Chun; Jin, Ling; Tong, Jing-Jing; Li, Sheng

2012-07-01

Passive remote sensing by Fourier-transform infrared (FTIR) spectrometry allows detection of air pollution. However, for the localization of a leak and a complete assessment of the situation in the case of the release of a hazardous cloud, information about the position and the distribution of a cloud is essential. Therefore, an imaging passive remote sensing system comprising an interferometer, a data acquisition and processing software, scan system, a video system, and a personal computer has been developed. The remote sensing of SF6 was done. The column densities of all directions in which a target compound has been identified may be retrieved by a nonlinear least squares fitting algorithm and algorithm of radiation transfer, and a false color image is displayed. The results were visualized by a video image, overlaid by false color concentration distribution image. The system has a high selectivity, and allows visualization and quantification of pollutant clouds.

Passive Infrared Thermographic Imaging for Mobile Robot Object Identification

NASA Astrophysics Data System (ADS)

Hinders, M. K.; Fehlman, W. L.

2010-02-01

The usefulness of thermal infrared imaging as a mobile robot sensing modality is explored, and a set of thermal-physical features used to characterize passive thermal objects in outdoor environments is described. Objects that extend laterally beyond the thermal camera's field of view, such as brick walls, hedges, picket fences, and wood walls as well as compact objects that are laterally within the thermal camera's field of view, such as metal poles and tree trunks, are considered. Classification of passive thermal objects is a subtle process since they are not a source for their own emission of thermal energy. A detailed analysis is included of the acquisition and preprocessing of thermal images, as well as the generation and selection of thermal-physical features from these objects within thermal images. Classification performance using these features is discussed, as a precursor to the design of a physics-based model to automatically classify these objects.

Two-Bin Kanban: Ordering Impact at Navy Medical Center San Diego

DTIC Science & Technology

2016-06-17

pretest (2013 data set) and posttest (2015 data set) analysis to avoid having the findings influenced by price changes. DMLSS does not track shipping...statistics based on those observations (Kabacoff, 2011, p. 112). Replacing the groups of observations with summary statistics allows the analyst...listed on the Acquisition Research Program website (www.acquisitionresearch.net). Acquisition Research Program Graduate School of Business & Public

Magnetic-Field-Response Measurement-Acquisition System

NASA Technical Reports Server (NTRS)

Woodward, Stanley E.; Shams, Qamar A.; Fox, Robert L.; Taylor, Bryant D.

2006-01-01

A measurement-acquisition system uses magnetic fields to power sensors and to acquire measurements from sensors. The system alleviates many shortcomings of traditional measurement-acquisition systems, which include a finite number of measurement channels, weight penalty associated with wires, use limited to a single type of measurement, wire degradation due to wear or chemical decay, and the logistics needed to add new sensors. Eliminating wiring for acquiring measurements can alleviate potential hazards associated with wires, such as damaged wires becoming ignition sources due to arcing. The sensors are designed as electrically passive inductive-capacitive or passive inductive-capacitive-resistive circuits that produce magnetic-field-responses. One or more electrical parameters (inductance, capacitance, and resistance) of each sensor can be variable and corresponds to a measured physical state of interest. The magnetic-field- response attributes (frequency, amplitude, and bandwidth) of the inductor correspond to the states of physical properties for which each sensor measures. For each sensor, the measurement-acquisition system produces a series of increasing magnetic-field harmonics within a frequency range dedicated to that sensor. For each harmonic, an antenna electrically coupled to an oscillating current (the frequency of which is that of the harmonic) produces an oscillating magnetic field. Faraday induction via the harmonic magnetic fields produces an electromotive force and therefore a current in the sensor. Once electrically active, the sensor produces its own harmonic magnetic field as the inductor stores and releases magnetic energy. The antenna of the measurement- acquisition system is switched from a transmitting to a receiving mode to acquire the magnetic-field response of the sensor. The rectified amplitude of the received response is compared to previous responses to prior transmitted harmonics, to ascertain if the measurement system has detected a response inflection. The "transmit-receive-compare" of sequential harmonics is repeated until the inflection is identified. The harmonic producing the amplitude inflection is the sensor resonant frequency. Resonant frequency and response amplitude are stored and then correlated to calibration data.

Laser range measurement for a satellite navigation scheme and mid-range path selection and obstacle avoidance. M.S. Thesis

NASA Technical Reports Server (NTRS)

Zuraski, G. D.

1972-01-01

The functions of a laser rangefinder on board an autonomous Martian roving vehicle are discussed. The functions are: (1) navigation by means of a passive satellite and (2) mid-range path selection and obstacle avoidance. The feasibility of using a laser to make the necessary range measurements is explored and a preliminary design is presented. The two uses of the rangefinder dictate widely different operating parameters making it impossible to use the same system for both functions.

[Delayed reactions of active avoidance in white rats under conditions of an alternative choice].

PubMed

Ioseliani, T K; Sikharulidze, N I; Kadagishvili, A Ia; Mitashvili, E G

1995-01-01

It was shown that if the rats had been learned and then tested using conventional pain punishment of erroneous choice they were able to solve the problem of alternative choice only in the period of immediate action of conditioned stimuli. If the pain punishment for erroneously chosen compartment had not been applied in animal learning and testing, rats successfully solved the problem of alternative choice even after 5-second delay. Introduction of pain punishment led to the frustration of earlier elaborated delayed avoidance reactions. Analysis of the obtained results allows us to argue that the apparent incapability of white rats for solving the problems of delayed avoidance is caused by simultaneous action of two different mechanisms, i.e., those of the active and passive avoidance rather than short-term memory deficit.

Environmental triggers and avoidance in the management of asthma

PubMed Central

Gautier, Clarisse; Charpin, Denis

2017-01-01

Identifying asthma triggers forms the basis of environmental secondary prevention. These triggers may be allergenic or nonallergenic. Allergenic triggers include indoor allergens, such as house dust mites (HDMs), molds, pets, cockroaches, and rodents, and outdoor allergens, such as pollens and molds. Clinical observations provide support for the role of HDM exposure as a trigger, although avoidance studies provide conflicting results. Molds and their metabolic products are now considered to be triggers of asthma attacks. Pets, dogs, and especially cats can undoubtedly trigger asthmatic symptoms in sensitized subjects. Avoidance is difficult and rarely adhered to by families. Cockroach allergens contribute to asthma morbidity, and avoidance strategies can lead to clinical benefit. Mouse allergens are mostly found in inner-city dwellings, but their implication in asthma morbidity is debated. In the outdoors, pollens can induce seasonal asthma in sensitized individuals. Avoidance relies on preventing pollens from getting into the house and on minimizing seasonal outdoor exposure. Outdoor molds may lead to severe asthma exacerbations. Nonallergenic triggers include viral infections, active and passive smoking, meteorological changes, occupational exposures, and other triggers that are less commonly involved. Viral infection is the main asthma trigger in children. Active smoking is associated with higher asthma morbidity, and smoking cessation interventions should be personalized. Passive smoking is also a risk factor for asthma exacerbation. The implementation of public smoking bans has led to a reduction in the hospitalization of asthmatic children. Air pollution levels have been linked with asthmatic symptoms, a decrease in lung function, and increased emergency room visits and hospitalizations. Since avoidance is not easy to achieve, clean air policies remain the most effective strategy. Indoor air is also affected by air pollutants, such as cigarette smoke and volatile organic compounds generated by building and cleaning materials. Occupational exposures include work-exacerbated asthma and work-related asthma. PMID:28331347

Zinc Chloride and Lead Acetate-Induced Passive Avoidance Memory Retention Deficits Reversed by Nicotine and Bucladesine in Mice.

PubMed

Tabrizian, Kaveh; Yazdani, Abdolmajid; Baheri, Behnam; Payandemehr, Borna; Sanati, Mehdi; Hashemzaei, Mahmoud; Miri, Abdolhossein; Zandkarimi, Majid; Belaran, Maryam; Fanoudi, Sahar; Sharifzadeh, Mohammad

2016-01-01

It is very important to investigate the neurotoxic effects of metals on learning and memory processes. In this study, we tried to investigate the effects and time course properties of oral administration of zinc chloride (25, 50, and 75 mg/kg, for 2 weeks), lead acetate (250, 750, 1,500, and 2,500 ppm for 4, 6 and 8 weeks), and their possible mechanisms on a model of memory function. For this matter, we examined the intra-peritoneal injections of nicotine (0.25, 0.5, 1, and 1.5 mg/kg) and bucladesine (50, 100, 300, and 600 nM/mouse) for 4 days alone and in combination with mentioned metals in the step-through passive avoidance task. Control animals received saline, drinking water, saline, and DMSO (dimethyl sulfoxide)/deionized water (1:9), respectively. At the end of each part of studies, animals were trained for 1 day in step-through task. The avoidance memory retention alterations were evaluated 24 and 48 h later in singular and combinational studies. Zinc chloride (75 mg/kg) oral gavage for 2 weeks decreased latency times compared to control animals. Also, lead acetate (750 ppm oral administrations for 8 weeks) caused significant lead blood levels and induced avoidance memory retention impairments. Four-days intra-peritoneal injection of nicotine (1 mg/kg) increased latency time compared to control animals. Finally, findings of this research showed that treatment with intra-peritoneal injections of nicotine (1 mg/kg) and/or bucladesine (600 nM/mouse) reversed zinc chloride- and lead acetate-induced avoidance memory retention impairments. Taken together, these results showed the probable role of cholinergic system and protein kinase A pathways in zinc chloride- and lead acetate-induced avoidance memory alterations.

Active and passive spatial learning in human navigation: acquisition of survey knowledge.

PubMed

Chrastil, Elizabeth R; Warren, William H

2013-09-01

It seems intuitively obvious that active exploration of a new environment would lead to better spatial learning than would passive visual exposure. It is unclear, however, which components of active learning contribute to spatial knowledge, and previous literature is decidedly mixed. This experiment tests the contributions of 4 components to metric survey knowledge: visual, vestibular, and podokinetic information and cognitive decision making. In the learning phase, 6 groups of participants learned the locations of 8 objects in a virtual hedge maze by (a) walking, (b) being pushed in a wheelchair, or (c) watching a video, crossed with (1) making decisions about their path or (2) being guided through the maze. In the test phase, survey knowledge was assessed by having participants walk a novel shortcut from a starting object to the remembered location of a test object, with the maze removed. Performance was slightly better than chance in the passive video condition. The addition of vestibular information did not improve performance in the wheelchair condition, but the addition of podokinetic information significantly improved angular accuracy in the walking condition. In contrast, there was no effect of decision making in any condition. The results indicate that visual and podokinetic information significantly contribute to survey knowledge, whereas vestibular information and decision making do not. We conclude that podokinetic information is the primary component of active learning for the acquisition of metric survey knowledge. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Socially acquired predator avoidance: is it just classical conditioning?

PubMed

Griffin, Andrea S

2008-06-15

Associative learning theories presume the existence of a general purpose learning process, the structure of which does not mirror the demands of any particular learning problem. In contrast, learning scientists working within an Evolutionary Biology tradition believe that learning processes have been shaped by ecological demands. One potential means of exploring how ecology may have modified properties of acquisition is to use associative learning theory as a framework within which to analyse a particular learning phenomenon. Recent work has used this approach to examine whether socially transmitted predator avoidance can be conceptualised as a classical conditioning process in which a novel predator stimulus acts as a conditioned stimulus (CS) and acquires control over an avoidance response after it has become associated with alarm signals of social companions, the unconditioned stimulus (US). I review here a series of studies examining the effect of CS/US presentation timing on the likelihood of acquisition. Results suggest that socially acquired predator avoidance may be less sensitive to forward relationships than traditional classical conditioning paradigms. I make the case that socially acquired predator avoidance is an exciting novel one-trial learning paradigm that could be studied along side fear conditioning. Comparisons between social and non-social learning of danger at both the behavioural and neural level may yield a better understanding of how ecology might shape properties and mechanisms of learning.

Caffeine impairs the acquisition and retention, but not the consolidation of Pavlovian conditioned freezing in mice

PubMed Central

Dubroqua, Sylvain; Low, Samuel R.L.; Yee, Benjamin K.; Singer, Philipp

2014-01-01

Rationale The psychoactive substance, caffeine may improve cognitive performance, but its direct impact on learning and memory remains ill-defined. Conflicting reports suggest that caffeine may impair as well as enhance Pavlovian fear conditioning in animals, and its effect may vary across different phases of learning. Objectives To dissect the effect of a motor-stimulant dose of caffeine (30 mg/kg i.p.) on acquisition, retrieval or consolidation of conditioned fear in C57BL/6 mice. Methods Fear conditioning was evaluated in a conditioned freezing paradigm comprising 3 tone-shock pairings and a two-way active avoidance paradigm lasting two consecutive days with 80 conditioning trials per test session. Results Conditioning to both the discrete tone conditioned stimulus (CS) and the context was markedly impaired by caffeine. The deficits were similarly evident when caffeine was administered prior to acquisition or retrieval (48 and 72 h after conditioning); and the most severe impairment was seen in animals given caffeine before acquisition and before retrieval. A comparable deficit was observed in the conditioned active avoidance test. By contrast, caffeine administered immediately following acquisition neither affected the expression of tone freezing nor context freezing. Conclusions The present study challenges the previous report that caffeine primarily disrupts hippocampus-dependent conditioning to the context. At the relevant dose range, acute caffeine likely exerts more widespread impacts beyond the hippocampus, including amygdala and striatum that are anatomically connected to the hippocampus; and together they support the acquisition and retention of fear memories to discrete stimuli as well as diffused contextual cues. PMID:25172668

C. S. Peirce's Dialogical Conception of Sign Processes

ERIC Educational Resources Information Center

Bergman, Mats

2005-01-01

This article examines the contention that the central concepts of C. S. Peirce's semeiotic are inherently communicational. It is argued that the Peircean approach avoids the pitfalls of objectivism and constructivism, rendering the sign-user neither a passive recipient nor an omnipotent creator of meaning. Consequently, semeiotic may serve as a…

Behavioral Strategies for Nonsmokers: Avoiding and Confronting Smokers.

ERIC Educational Resources Information Center

Jason, Leonard A.

Nonsmokers repeatedly breathe smoke-polluted air in various settings, despite the evidence demonstrating the deleterious consequences upon such passive smokers. The extent of exposure to environmental irritants during a 17-day baseline period was tested, and the efficacy of two simple behavioral strategies in reducing smoke were documented…

The Draws and Drawbacks of College Students' Active Procrastination

ERIC Educational Resources Information Center

Hensley, Lauren C.

2016-01-01

When students procrastinate, they divert time from academics toward other activities, returning to academics at a later time. Active procrastination is a departure from the form of procrastination defined by scholars as passive (i.e., avoidant, maladaptive) in nature. Hensley selected the methodology (phenomenology) in order to undertake an…

Solar heated beehives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hardin, B.

1985-02-01

A new translucent plastic cover for bee hives is described which will serve as a passive solar collector and insulator. Scientists at the USDA-ARS designed the cover to maintain bees in cold weather. It should be of interest to beekeepers in northern states who have had to destroy colonies to avoid overwintering costs.

Foraging scent marks of bumblebees: footprint cues rather than pheromone signals

NASA Astrophysics Data System (ADS)

Wilms, Jessica; Eltz, Thomas

2008-02-01

In their natural habitat foraging bumblebees refuse to land on and probe flowers that have been recently visited (and depleted) by themselves, conspecifics or other bees, which increases their overall rate of nectar intake. This avoidance is often based on recognition of scent marks deposited by previous visitors. While the term ‘scent mark’ implies active labelling, it is an open question whether the repellent chemicals are pheromones actively and specifically released during flower visits, or mere footprints deposited unspecifically wherever bees walk. To distinguish between the two possibilities, we presented worker bumblebees ( Bombus terrestris) with three types of feeders in a laboratory experiment: unvisited control feeders, passive feeders with a corolla that the bee had walked over on its way from the nest (with unspecific footprints), and active feeders, which the bee had just visited and depleted, but which were immediately refilled with sugar water (potentially with specific scent marks). Bumblebees rejected both active and passive feeders more frequently than unvisited controls. The rate of rejection of passive feeders was only slightly lower than that of active feeders, and this difference vanished completely when passive corollas were walked over repeatedly on the way from the nest. Thus, mere footprints were sufficient to emulate the repellent effect of an actual feeder visit. In confirmation, glass slides on which bumblebees had walked on near the nest entrance accumulated hydrocarbons (alkanes and alkenes, C23 to C31), which had previously been shown to elicit repellency in flower choice experiments. We conclude that repellent scent marks are mere footprints, which foraging bees avoid when they encounter them in a foraging context.

In vivo modulation of the behavioral effects of nicotine by the coumarins xanthotoxin, bergapten, and umbelliferone.

PubMed

Budzynska, Barbara; Skalicka-Wozniak, Krystyna; Kruk-Slomka, Marta; Wydrzynska-Kuzma, Malgorzata; Biala, Grazyna

2016-06-01

Nicotine, a dominant alkaloid found in tobacco, is responsible for physical dependence, as well as addiction to cigarette smoking; consequently, smoking cessation is a very difficult process. Hepatic cytochrome P-450 2A6 (CYP2A6) is involved in the 70-80 % of the initial metabolism of nicotine and its co-metabolites. As this metabolism is slowed by inhibitors of CYP2A6, this kind of enzymatic inhibition has been proposed as a novel target for smoking cessation. Nicotine administered alone improved memory acquisition and consolidation as well as exerted antidepressive activity in animal models. These effects persist for 24 h. However, they are completely extinguished 48 h after administration. To investigate if the coumarins prolong the behavioral effects of nicotine, the forced swimming test (FST)-animal models of depression, and passive avoidance (PA) test-memory and learning paradigm were used. This study revealed that three CYP2A6 inhibitors: two furanocoumarins, xanthotoxin (15 mg/kg) and bergapten (25 mg/kg), and the simple coumarin umbelliferone (25 mg/kg), prolonged the antidepressive and procognitive effects of nicotine. These natural products may offer a new approach to the treatment of nicotinism as antidepressant and memory improvement actions are one of the main factors of nicotine dependence.

Attenuation of neurobehavioral and neurochemical abnormalities in animal model of cognitive deficits of Alzheimer's disease by fermented soybean nanonutraceutical.

PubMed

Bhatt, Prakash Chandra; Pathak, Shruti; Kumar, Vikas; Panda, Bibhu Prasad

2018-02-01

The present study was performed to evaluate the efficacy of nanonutraceuticals (NN) for attenuation of neurobehavioral and neurochemical abnormalities in Alzheimer's disease. Solid-state fermentation of soybean with Bacillus subtilis was performed to produce different metabolites (nattokinase, daidzin, genistin and glycitin and menaquinone-7). Intoxication of rats with colchicine caused impairment in learning and memory which was demonstrated in neurobehavioral paradigms (Morris water maze and passive avoidance) linked with decreased activity of acetylcholinesterase (AChE). NN treatment led to a significant increase in TLT in the retention trials as compared to acquisition trial TLT suggesting an improved learning and memory in rats. Further, treatment of NN caused an increase in the activity of AChE (42%), accompanied with a reduced activity of glutathione (42%), superoxide dismutase (43%) and catalase (41%). It also decreased the level of lipid peroxidation (28%) and protein carbonyl contents (30%) in hippocampus as compared to those treated with colchicine alone, suggesting a possible neuroprotective efficacy of NN. Interestingly, in silico studies also demonstrated an effective amyloid-β and BACE-1 inhibition activity. These findings clearly indicated that NN reversed colchicine-induced behavioral and neurochemical alterations through potent antioxidant activity and could possibly impart beneficial effects in cognitive defects associated with Alzheimer's disease.

Suggested Best Practice for seismic monitoring and characterization of non-conventional reservoirs

NASA Astrophysics Data System (ADS)

Malin, P. E.; Bohnhoff, M.; terHeege, J. H.; Deflandre, J. P.; Sicking, C.

2017-12-01

High rates of induced seismicity and gas leakage in non-conventional production have become a growing issue of public concern. It has resulted in calls for independent monitoring before, during and after reservoir production. To date no uniform practice for it exists and few reservoirs are locally monitored at all. Nonetheless, local seismic monitoring is a pre-requisite for detecting small earthquakes, increases of which can foreshadow damaging ones and indicate gas leaks. Appropriately designed networks, including seismic reflection studies, can be used to collect these and Seismic Emission Tomography (SET) data, the latter significantly helping reservoir characterization and exploitation. We suggest a Step-by-Step procedure for implementing such networks. We describe various field kits, installations, and workflows, all aimed at avoiding damaging seismicity, as indicators of well stability, and improving reservoir exploitation. In Step 1, a single downhole seismograph is recommended for establishing baseline seismicity before development. Subsequent Steps are used to decide cost-effective ways of monitoring treatments, production, and abandonment. We include suggestions for monitoring of disposal and underground storage. We also describe how repeated SET observations improve reservoir management as well as regulatory monitoring. Moreover, SET acquisition can be included at incremental cost in active surveys or temporary passive deployments.

Selective and Protracted Effect of Nifedipine on Fear Memory Extinction Correlates with Induced Stress Response

ERIC Educational Resources Information Center

Waltereit, Robert; Mannhardt, Sonke; Nescholta, Sabine; Maser-Gluth, Christiane; Bartsch, Dusan

2008-01-01

Memory extinction, defined as a decrease of a conditioned response as a function of a non-reinforced conditioned stimulus presentation, has high biological and clinical relevance. Extinction is not a passive reversing or erasing of the plasticity associated with acquisition, but a novel, active learning process. Nifedipine blocks L-type voltage…

Sensory Desensitization Training for Successful Net Application and EEG/ERP Acquisition in Difficult to Test Children

ERIC Educational Resources Information Center

Roesler, Cynthia P.; Flax, Judy; MacRoy-Higgins, Michelle; Fermano, Zena; Morgan-Byrne, Julie; Benasich, April A.

2013-01-01

This study examined the effectiveness of sensory desensitization training for 12 nonverbal children with autism to facilitate participation in an electrophysiological study assessing linguistic processing. Sensory desensitization was achieved for 10 of the 12 children and thus allowed collection of usable data in a passive linguistic paradigm.…

78 FR 20624 - Information Collection Requirement; Defense Federal Acquisition Regulation Supplement (DFARS...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-05

.... Needs and Uses: DoD uses advance shipment notices for the shipment of material containing RFID tag data... encoded on the RFID tag with the corresponding shipment. Use of the RFID technology permits DoD an... Identification Advance Shipment Notices, requires the contractor to ensure that the data on each passive RFID tag...

Effects of oxotremorine and physostigmine on the inhibitory avoidance impairment produced by amitriptyline in male and female mice.

PubMed

Monleón, Santiago; Urquiza, Adoración; Vinader-Caerols, Concepción; Parra, Andrés

2009-12-28

We have previously observed that amitriptyline and other antidepressants produce impairing effects on inhibitory avoidance (also called passive avoidance) in mice of both sexes. In the present study we investigated the involvement of the cholinergic system in the inhibitory avoidance impairment produced by acute amitriptyline in male and female CD1 mice. For this purpose, the effects on said task of acute i.p. administration of several doses of amitriptyline, either alone or in combination with the cholinergic agonists oxotremorine and physostigmine, were evaluated. Pre-training administration of 5, 7.5, 10 or 15 mg/kg of amitriptyline produced a significant impairment of inhibitory avoidance in both males and females. When oxotremorine (0.05 or 0.1 mg/kg) was co-administered with amitriptyline, the antidepressant's impairing effect was partially counteracted, although inhibitory avoidance learning was not significant. Physostigmine (0.15, 0.3 or 0.6 mg/kg) counteracted the impairment produced by amitriptyline, as mice treated with both drugs exhibited inhibitory avoidance learning. These results show that the inhibitory avoidance impairment produced by amitriptyline in male and female mice is mediated, at least partially, by the cholinergic system.

Functional Connectivity in Frequency-Tagged Cortical Networks During Active Harm Avoidance

PubMed Central

Miskovic, Vladimir; Príncipe, José C.; Keil, Andreas

2015-01-01

Abstract Many behavioral and cognitive processes are grounded in widespread and dynamic communication between brain regions. Thus, the quantification of functional connectivity with high temporal resolution is highly desirable for capturing in vivo brain function. However, many of the commonly used measures of functional connectivity capture only linear signal dependence and are based entirely on relatively simple quantitative measures such as mean and variance. In this study, the authors used a recently developed algorithm, the generalized measure of association (GMA), to quantify dynamic changes in cortical connectivity using steady-state visual evoked potentials (ssVEPs) measured in the context of a conditioned behavioral avoidance task. GMA uses a nonparametric estimator of statistical dependence based on ranks that are efficient and capable of providing temporal precision roughly corresponding to the timing of cognitive acts (∼100–200 msec). Participants viewed simple gratings predicting the presence/absence of an aversive loud noise, co-occurring with peripheral cues indicating whether the loud noise could be avoided by means of a key press (active) or not (passive). For active compared with passive trials, heightened connectivity between visual and central areas was observed in time segments preceding and surrounding the avoidance cue. Viewing of the threat stimuli also led to greater initial connectivity between occipital and central regions, followed by heightened local coupling among visual regions surrounding the motor response. Local neural coupling within extended visual regions was sustained throughout major parts of the viewing epoch. These findings are discussed in a framework of flexible synchronization between cortical networks as a function of experience and active sensorimotor coupling. PMID:25557925

Viability of a Bioelectrical Signal Acquisition System Energized by Cellphone with NFC.

PubMed

Kay, Marcel Seiji; Iaione, Fábio

2015-01-01

Currently, smartphones are used in various systems in the medical field due to the presence of various features, notably Near Field Communication (NFC). NFC utilizes communication technology and an energy supply based on electromagnetic induction. One of the most common medical tests is the electrocardiogram (ECG), through which various heart diseases can be diagnosed. The objective of this study is to evaluate the feasibility of providing power to a bioelectrical signal acquisition module using a mobile phone with NFC. After testing it was indicated that it is possible to construct a passive module to acquire ECG signals using NFC mobile phone.

Magnetic Field Response Measurement Acquisition System

NASA Technical Reports Server (NTRS)

Woodard, Stanley E. (Inventor); Taylor, Bryant D. (Inventor); Shams, Qamar A. (Inventor); Fox, Robert L. (Inventor); Fox, Christopher L. (Inventor); Fox, Melanie L. (Inventor); Bryant, Robert G. (Inventor)

2006-01-01

Magnetic field response sensors designed as passive inductor-capacitor circuits produce magnetic field responses whose harmonic frequencies correspond to states of physical properties for which the sensors measure. Power to the sensing element is acquired using Faraday induction. A radio frequency antenna produces the time varying magnetic field used for powering the sensor, as well as receiving the magnetic field response of the sensor. An interrogation architecture for discerning changes in sensor s response kequency, resistance and amplitude is integral to the method thus enabling a variety of measurements. Multiple sensors can be interrogated using this method, thus eliminating the need to have a data acquisition channel dedicated to each sensor. The method does not require the sensors to be in proximity to any form of acquisition hardware. A vast array of sensors can be used as interchangeable parts in an overall sensing system.

Study to investigate and evaluate means of optimizing the radar function for the space shuttle

NASA Technical Reports Server (NTRS)

1976-01-01

A detailed analysis of the spiral scan was performed for antenna sizes ranging from 20 inches to 36 inches in diameter and for search angles characteristic of both the radar and the communication acquisition modes. The power budgets for passive target radar detection were calculated for antenna diameters ranging from 20 to 36 inches. Dwell times commensurate with spiral scan were used for these budget calculations. The signal design for the candidate pulse Doppler system is summarized. Ground return analysis carried out for the passive target radar mode is examined, and the details are presented. A concluding description of the proposed candidate radar/communication system configuration is given.

Real Time Fatigue Damage Growth Assessment of a Composite Three-Stringer Panel Using Passive Thermography

NASA Technical Reports Server (NTRS)

Zalameda, Joseph N.; Burke, Eric R.; Horne, Michael R.; Bly, James B.

2015-01-01

Fatigue testing of advanced composite structures is critical to validate both structural designs and damage prediction models. In-situ inspection methods are necessary to track damage onset and growth as a function of load cycles. Passive thermography is a large area, noncontact inspection technique that is used to detect composite damage onset and growth in real time as a function of fatigue cycles. The thermal images are acquired in synchronicity to the applied compressive load using a dual infrared camera acquisition system for full (front and back) coverage. Image processing algorithms are investigated to increase defect contrast areas. The thermal results are compared to non-immersion ultrasound inspections and acoustic emission data.

Partial reinforcement of avoidance and resistance to extinction in humans.

PubMed

Xia, Weike; Dymond, Simon; Lloyd, Keith; Vervliet, Bram

2017-09-01

In anxiety, maladaptive avoidance behavior provides for near-perfect controllability of potential threat. There has been little laboratory-based treatment research conducted on controllability as a contributing factor in the transition from adaptive to maladaptive avoidance. Here, we investigated for the first time whether partial reinforcement rate, or the reliability of avoidance at controlling or preventing contact with an aversive event, influences subsequent extinction of avoidance in humans. Five groups of participants were exposed to different partial reinforcement rates where avoidance cancelled upcoming shock on 100%, 75%, 50%, 25% or 0% of trials. During extinction, all shocks were withheld. Avoidance behavior, online shock expectancy ratings and skin conductance responses (SCRs) were measured throughout. We found that avoidance was a function of relative controllability: higher reinforcement rate groups engaged in significantly more extinction-resistant avoidance than lower reinforcement groups, and shock expectancy was inversely related with reinforcement rate during avoidance acquisition. Partial reinforcement effects were not evident in SCRs. Overall, the current study highlights the clinical relevance of laboratory-based treatment research on partial reinforcement or controllability effects on extinction of avoidance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Monte Carlo patient study on the comparison of prompt gamma and PET imaging for range verification in proton therapy

NASA Astrophysics Data System (ADS)

Moteabbed, M.; España, S.; Paganetti, H.

2011-02-01

The purpose of this work was to compare the clinical adaptation of prompt gamma (PG) imaging and positron emission tomography (PET) as independent tools for non-invasive proton beam range verification and treatment validation. The PG range correlation and its differences with PET have been modeled for the first time in a highly heterogeneous tissue environment, using different field sizes and configurations. Four patients with different tumor locations (head and neck, prostate, spine and abdomen) were chosen to compare the site-specific behaviors of the PG and PET images, using both passive scattered and pencil beam fields. Accurate reconstruction of dose, PG and PET distributions was achieved by using the planning computed tomography (CT) image in a validated GEANT4-based Monte Carlo code capable of modeling the treatment nozzle and patient anatomy in detail. The physical and biological washout phenomenon and decay half-lives for PET activity for the most abundant isotopes such as 11C, 15O, 13N, 30P and 38K were taken into account in the data analysis. The attenuation of the gamma signal after traversing the patient geometry and respective detection efficiencies were estimated for both methods to ensure proper comparison. The projected dose, PG and PET profiles along many lines in the beam direction were analyzed to investigate the correlation consistency across the beam width. For all subjects, the PG method showed on average approximately 10 times higher gamma production rates than the PET method before, and 60 to 80 times higher production after including the washout correction and acquisition time delay. This rate strongly depended on tissue density and elemental composition. For broad passive scattered fields, it was demonstrated that large differences exist between PG and PET signal falloff positions and the correlation with the dose distribution for different lines in the beam direction. These variations also depended on the treatment site and the particular subject. Thus, similar to PET, direct range verification with PG in passive scattering is not easily viable. However, upon development of an optimized 3D PG detector, indirect range verification by comparing measured and simulated PG distributions (currently being explored for the PET method) would be more beneficial because it can avoid the inherent biological challenges of the PET imaging. The improved correlation of PG and PET with dose when using pencil beams was evident. PG imaging was found to be potentially advantageous especially for small tumors in the presence of high tissue heterogeneities. Including the effects of detector acceptance and efficiency may hold PET superior in terms of the amplitude of the detected signal (depending on the future development of PG detection technology), but the ability to perform online measurements and avoid signal disintegration (due to washout) with PG are important factors that can outweigh the benefits of higher detection sensitivity.

Monte Carlo patient study on the comparison of prompt gamma and PET imaging for range verification in proton therapy.

PubMed

Moteabbed, M; España, S; Paganetti, H

2011-02-21

The purpose of this work was to compare the clinical adaptation of prompt gamma (PG) imaging and positron emission tomography (PET) as independent tools for non-invasive proton beam range verification and treatment validation. The PG range correlation and its differences with PET have been modeled for the first time in a highly heterogeneous tissue environment, using different field sizes and configurations. Four patients with different tumor locations (head and neck, prostate, spine and abdomen) were chosen to compare the site-specific behaviors of the PG and PET images, using both passive scattered and pencil beam fields. Accurate reconstruction of dose, PG and PET distributions was achieved by using the planning computed tomography (CT) image in a validated GEANT4-based Monte Carlo code capable of modeling the treatment nozzle and patient anatomy in detail. The physical and biological washout phenomenon and decay half-lives for PET activity for the most abundant isotopes such as (11)C, (15)O, (13)N, (30)P and (38)K were taken into account in the data analysis. The attenuation of the gamma signal after traversing the patient geometry and respective detection efficiencies were estimated for both methods to ensure proper comparison. The projected dose, PG and PET profiles along many lines in the beam direction were analyzed to investigate the correlation consistency across the beam width. For all subjects, the PG method showed on average approximately 10 times higher gamma production rates than the PET method before, and 60 to 80 times higher production after including the washout correction and acquisition time delay. This rate strongly depended on tissue density and elemental composition. For broad passive scattered fields, it was demonstrated that large differences exist between PG and PET signal falloff positions and the correlation with the dose distribution for different lines in the beam direction. These variations also depended on the treatment site and the particular subject. Thus, similar to PET, direct range verification with PG in passive scattering is not easily viable. However, upon development of an optimized 3D PG detector, indirect range verification by comparing measured and simulated PG distributions (currently being explored for the PET method) would be more beneficial because it can avoid the inherent biological challenges of the PET imaging. The improved correlation of PG and PET with dose when using pencil beams was evident. PG imaging was found to be potentially advantageous especially for small tumors in the presence of high tissue heterogeneities. Including the effects of detector acceptance and efficiency may hold PET superior in terms of the amplitude of the detected signal (depending on the future development of PG detection technology), but the ability to perform online measurements and avoid signal disintegration (due to washout) with PG are important factors that can outweigh the benefits of higher detection sensitivity.

Continuous place avoidance task reveals differences in spatial navigation in male and female rats.

PubMed

Cimadevilla, J M; Fenton, A A; Bures, J

2000-01-01

A new place navigation test was used to estimate the spatial orientation abilities of male and female rats. Animals had to avoid a room frame defined area on a rotating arena, entering of which was punished by mild footshock, i.e. rats had to avoid the same place in the room but different parts of the floor, which was rotated through the punished zone. Because of the rotation of the arena (one revolution per min), animals could not rely on intramaze cues and only extramaze landmarks could be used for accurate navigation. During 8 consecutive days rats were exposed to daily 40-min sessions, consisting of 20-min acquisition and 20-min extinction (shock discontinued). The position of the punished sector centered around one of the four mutually perpendicular azimuths was daily changed in a predetermined sequence. The results showed no male female differences during acquisition and better performance of males during extinction. The performance of females was not affected by estral cycle-related hormonal changes. The findings are discussed in the light of controversial results of research into sex differences in spatial abilities.

Passive avoidance and complex maze learning in the senescence accelerated mouse (SAM): age and strain comparisons of SAM P8 and R1.

PubMed

Spangler, Edward L; Patel, Namisha; Speer, Dorey; Hyman, Michael; Hengemihle, John; Markowska, Alicja; Ingram, Donald K

2002-02-01

Two strains of the senescence accelerated mouse, P8 and R1,were tested in footshock-motivated passive avoidance (PA; P8, 3-21 months; R1, 3-24 months) and 14-unit T-maze (P8 and R1, 9, and 15 months) tasks. For PA, entry to a dark chamber from a lighted chamber was followed by a brief shock. Latency to enter the dark chamber 24 hours later served as a measure of retention. Two days of active avoidance training in a straight runway preceded 2 days (8 trials/day) of testing in the 14-unit T-maze. For PA retention, older P8 mice entered the dark chamber more quickly than older R1 mice, whereas no differences were observed between young P8 or R1 mice. In the 14-unit T-maze, age-related learning performance deficits were reflected in higher error scores for older mice. P8 mice were actually superior learners; that is, they had lower error scores compared with those of age-matched R1 counterparts. Although PA learning results were in agreement with other reports, results obtained in the 14-unit T-maze were not consistent with previous reports of learning impairments in the P8 senescence accelerated mouse.

Abnormal decision-making in generalized anxiety disorder: Aversion of risk or stimulus-reinforcement impairment?

PubMed

Teng, Cindy; Otero, Marcela; Geraci, Marilla; Blair, R J R; Pine, Daniel S; Grillon, Christian; Blair, Karina S

2016-03-30

There is preliminary data indicating that patients with generalized anxiety disorder (GAD) show impairment on decision-making tasks requiring the appropriate representation of reinforcement value. The current study aimed to extend this literature using the passive avoidance (PA) learning task, where the participant has to learn to respond to stimuli that engender reward and avoid responding to stimuli that engender punishment. Six stimuli engendering reward and six engendering punishment are presented once per block for 10 blocks of trials. Thirty-nine medication-free patients with GAD and 29 age-, IQ and gender matched healthy comparison individuals performed the task. In addition, indexes of social functioning as assessed by the Global Assessment of Functioning (GAF) scale were obtained to allow for correlational analyzes of potential relations between cognitive and social impairments. The results revealed a Group-by-Error Type-by-Block interaction; patients with GAD committed significantly more commission (passive avoidance) errors than comparison individuals in the later blocks (blocks 7,8, and 9). In addition, the extent of impairment on these blocks was associated with their functional impairment as measured by the GAF scale. These results link GAD with anomalous decision-making and indicate that a potential problem in reinforcement representation may contribute to the severity of expression of their disorder. Copyright © 2016. Published by Elsevier Ireland Ltd.

[An increase in allergic diseases in childhood--current hypotheses and possible prevention].

PubMed

Kurz, Herbert; Riedler, Jose

2003-01-01

During the last few decades there has ben a significant rise in the prevalence of allergic diseases such as asthma, hay fever and atopic dermatitis. Epidemiological studies strongly suggest that this increase is real and not due to changes in diagnostic labelling. It has become increasingly clear that a complex interplay between genetic and environmental factors account for this phenomenon. Genetically predisposed individuals are at an increased susceptibility to develop asthma or other allergic diseases when exposed to certain environmental or lifestyle factors. Particularly passive smoking has been shown to increase the risk for asthma in many studies and for atopy at least in some studies. This association is less clear for the exposure to sulfur dioxide, particulate matter, diesel exhaust and ozone. Lifestyle factors like socioeconomic status, sib-ship size, early childhood infections, dietary habits, growing up in antroposophic families or on a farm are more and more realised to be of great relevance for the development of allergic conditions. At the moment, there is a lot of uncertainty about which recommendations should be given for primary prevention. Recent studies have challenged the old paradigma that avoidance of early allergen contact could prevent the development of allergic disease. However, there is consensus that avoidance of smoking during pregnancy and avoidance of passive smoking during childhood should be recommended for primary prevention of asthma.

Antiamnesic effect of acyl-prolyl-containing dipeptide (GVS-111) in compression-induced damage to frontal cortex.

PubMed

Romanova, G A; Mirzoev, T K; Barskov, I V; Victorov, I V; Gudasheva, T A; Ostrovskaya, R U

2000-09-01

Antiamnestic effect of acyl-prolyl-containing dipeptide GVS-111 was demonstrated in rats with bilateral compression-induced damage to the frontal cortex. Both intraperitoneal and oral administration of the dipeptide improved retrieval of passive avoidance responses in rats with compression-induced cerebral ischemia compared to untreated controls.

Principal Leadership Styles and the Academic Achievement of Students with Disabilities: A Mixed Methods Approach

ERIC Educational Resources Information Center

Brander, Bryan Patrick

2013-01-01

The purpose of this study was to examine the relationship between principal leadership styles and the academic achievement of students with disabilities. Participants were North Carolina elementary and middle school principals and teachers. The researcher examined what leadership styles (transformational, transactional, or passive-avoidant) are…

An Evaluation of the Response Modulation Hypothesis in Relation to Attention-Deficit/ Hyperactivity Disorder

ERIC Educational Resources Information Center

Farmer, Richard F.; Rucklidge, Julia J.

2006-01-01

Several hypotheses related to Newman's (e.g., Patterson & Newman, 1993) response modulation hypothesis were examined among adolescents with attention-deficit/hyperactivity disorder (ADHD; n = 18) and normal controls (n = 23). Consistent with predictions, youth with ADHD committed more passive avoidance errors (PAEs) than controls during the latter…

Learning and memory effects of neonatal methamphetamine exposure in rats: Role of reactive oxygen species and age at assessment.

PubMed

Jablonski, Sarah A; Williams, Michael T; Vorhees, Charles V

2017-11-01

In utero methamphetamine (MA) exposure leads to a range of adverse effects, such as decreased attention, reduced working-memory capability, behavioral dysregulation, and spatial memory impairments in exposed children. In the current experiment, preweaning Sprague-Dawley rats-as a model of third trimester human exposure-were administered the spin trapping agent, N-tert-butyl-α-phenylnitrone (PBN), daily prior to MA. Rats were given 0 (SAL) or 40 mg/kg PBN prior to each MA dose (10 mg/kg, 4× per day) from postnatal day (P) 6-15. Littermates underwent Cincinnati water maze, Morris water maze, and radial water maze assessment beginning on P30 (males) or P60 (females). Males were also tested for conditioned contextual and cued freezing, while females were trained in passive avoidance. Findings show that, regardless of age/sex, neonatal MA induced deficits in all tests, except passive avoidance. PBN did not ameliorate these effects, but had a few minor effects. Taken together, MA induced learning deficits emerge early and persist, but the mechanism remains unknown. © 2017 Wiley Periodicals, Inc.

Ameliorative effect of Noni fruit extract on streptozotocin-induced memory impairment in mice.

PubMed

Pachauri, Shakti D; Verma, Priya Ranjan P; Dwivedi, Anil K; Tota, Santoshkumar; Khandelwal, Kiran; Saxena, Jitendra K; Nath, Chandishwar

2013-08-01

This study evaluated the effects of a standardized ethyl acetate extract of Morinda citrifolia L. (Noni) fruit on impairment of memory, brain energy metabolism, and cholinergic function in intracerebral streptozotocin (STZ)-treated mice. STZ (0.5 mg/kg) was administered twice at an interval of 48 h. Noni (50 and 100 mg/kg, postoperatively) was administered for 21 days following STZ administration. Memory function was evaluated using Morris Water Maze and passive avoidance tests, and brain levels of cholinergic function, oxidative stress, energy metabolism, and brain-derived neurotrophic factor (BDNF) were estimated. STZ caused memory impairment in Morris Water Maze and passive avoidance tests along with reduced brain levels of ATP, BDNF, and acetylcholine and increased acetylcholinesterase activity and oxidative stress. Treatment with Noni extract (100 mg/kg) prevented the STZ-induced memory impairment in both behavioral tests along with reduced oxidative stress and acetylcholinesterase activity, and increased brain levels of BDNF, acetylcholine, and ATP level. The study shows the beneficial effects of Noni fruit against STZ-induced memory impairment, which may be attributed to improved brain energy metabolism, cholinergic neurotransmission, BDNF, and antioxidative action.

The effect of facial expressions on peripersonal and interpersonal spaces.

PubMed

Ruggiero, Gennaro; Frassinetti, Francesca; Coello, Yann; Rapuano, Mariachiara; di Cola, Armando Schiano; Iachini, Tina

2017-11-01

Identifying individuals' intent through the emotional valence conveyed by their facial expression influences our capacity to approach-avoid these individuals during social interactions. Here, we explore if and how the emotional valence of others' facial expressiveness modulates peripersonal-action and interpersonal-social spaces. Through Immersive Virtual Reality, participants determined reachability-distance (for peripersonal space) and comfort-distance (for interpersonal space) from male/female virtual confederates exhibiting happy, angry and neutral facial expressions while being approached by (passive-approach) or walking toward (active-approach) them. Results showed an increase of distance when seeing angry rather than happy confederates in both approach conditions of comfort-distance. The effect also appeared in reachability-distance, but only in the passive-approach. Anger prompts avoidant behaviors, and thus an expansion of distance, particularly with a potential violation of near body space by an intruder. Overall, the findings suggest that peripersonal-action space, in comparison with interpersonal-social space, is similarly sensitive to the emotional valence of stimuli. We propose that this similarity could reflect a common adaptive mechanism shared by these spaces, presumably at different degrees, for ensuring self-protection functions.

The Effects of Focused/Unfocused Audio-Appended Reading Tasks on Intermediate Female EFL Learners' Written Accuracy

ERIC Educational Resources Information Center

Alavinia, Parviz; Shafaei, Ali; Salimi, Asghar

2018-01-01

The current research study was conducted to examine the impacts of focused and unfocused audio-appended reading tasks on female EFL learners' acquisition of a rule-bound structure (passive voice) and a non-rule-bound structure (prepositions). The participants of this study involved ninety intermediate female English learners. They were assigned…

Target Presentation Methodology for Tactical Field Evaluations

DTIC Science & Technology

1976-10-01

to making their observations. Finally, Sternberp and Banks J (during an investigation of search effectiveness with passive night vision...factors are likely to be more important in the acquisition process. ^J. Stemberg and J. Banks . Search Fffcstivcncss viih hwoive Nipht Vision...differently-colored low-contrast uni- forms (green field uniform and black pajama -type uniform) in a Jungle environment. They found that the

Cost effectiveness and budget impact of natalizumab in patients with relapsing multiple sclerosis.

PubMed

Chiao, Evelyn; Meyer, Kellie

2009-06-01

Disease-modifying therapy (DMT) is the largest single-cost item that contributes to the total per-patient cost of multiple sclerosis (MS), a disabling disorder of the central nervous system. Natalizumab is the most recent DMT to be approved for the treatment of relapsing MS and may be an attractive alternative to interferon beta and glatiramer acetate (GA). To determine from the perspective of a United States payer (1) the incremental cost effectiveness of natalizumab compared with other DMTs and (2) the budgetary impact of utilization of natalizumab for the treatment of relapsing MS. A combined cost effectiveness and budget impact model was developed. Model inputs were drug acquisition costs (wholesale acquisition cost), costs of drug administration and monitoring, costs of treating relapses, anticipated reduction in relapse rates after 2 years of therapy, and estimated market utilization of natalizumab. Outcomes included total 2-year costs of therapy per patient, costs per relapse avoided for each treatment, and overall 2-year costs to the health plan and per member per month (PMPM) costs. Drug acquisition costs are in 2008 US dollars, and all other costs were inflated to 2008 US dollars when necessary. Univariate sensitivity analyses were performed to determine the model inputs with the greatest influence on the cost per relapse avoided for natalizumab. The overall 2-year cost of therapy per patient was $72,120 for natalizumab, $56,790 for intramuscular (IM) interferon beta-1a (IFNbeta-1a), $56,773 for IFNbeta-1b, $57,180 for GA, and $58,538 for subcutaneous (SC) IFNbeta-1a. The cost per relapse avoided was lowest for natalizumab at $56,594, followed by $87,791 for IFNbeta-1b, $93,306 for IM IFNbeta-1a, $96,178 for SC IFNbeta-1a, and $103,665 for GA. The incremental cost-effectiveness ratios of natalizumab relative to IM IFNbeta-1a, IFNbeta-1b, GA, and SC IFNbeta-1a were $23,029, $24,452, $20,671, and $20,403 per additional relapse avoided, respectively. An increase in natalizumab utilization to 9% resulted in an increase of approximately $61 760 in total 2-year costs to a hypothetical health plan of 1 million members, or a $0.003 PMPM incremental cost. Univariate sensitivity analyses indicated that the model inputs with the most influence on cost per relapse avoided for natalizumab were the weighted average number of relapses before treatment and the anticipated relative relapse rate reduction. Natalizumab was the most cost-effective therapy as measured by total cost per relapse avoided, not withstanding a higher drug acquisition cost versus other DMTs. Entry of natalizumab to the market is likely to result in a minimal increase in health-plan costs on a PMPM basis. Limitations of the study include the use of a surrogate measure, relapse avoided, as an outcome measure; also, adverse events were not included in the model.

Investigating the genetic and environmental bases of biases in threat recognition and avoidance in children with anxiety problems

PubMed Central

2012-01-01

Background Adults with anxiety show biased categorization and avoidance of threats. Such biases may emerge through complex interplay between genetics and environments, occurring early in life. Research on threat biases in children has focuses on a restricted range of biases, with insufficient focus on genetic and environmental origins. Here, we explore differences between children with and without anxiety problems in under-studied areas of threat bias. We focused both on associations with anxious phenotype and the underlying gene-environmental correlates for two specific processes: the categorisation of threat faces and avoidance learning. Method Two-hundred and fifty 10-year old MZ and DZ twin pairs (500 individuals) completed tasks assessing accuracy in the labelling of threatening facial expressions and in the acquisition of avoidant responses to a card associated with a masked threatening face. To assess whether participants met criteria for an anxiety disorder, parents of twins completed a self-guided computerized version of the Development and Well-being Assessment (DAWBA). Comparison of MZ and DZ twin correlations using model-fitting were used to compute estimates of genetic, shared and non-shared environmental effects. Results Of the 500 twins assessed, 25 (5%) met diagnostic criteria for a current anxiety disorder. Children with anxiety disorders were more accurate in their ability to recognize disgust faces than those without anxiety disorders, but were commensurate on identifying other threatening face emotions (angry, fearful, sad). Children with anxiety disorders but also more strongly avoided selecting a conditioned stimulus than non-anxious children. While recognition of socially threatening faces was moderately heritable, avoidant responses were heavily influenced by the non-shared environment. Conclusion These data add to other findings on threat biases in anxious children. Specifically, we found biases in the labelling of some negative-valence faces and in the acquisition of avoidant responses. While non-shared environmental effects explained all of the variance on threat avoidance, some of this may be due to measurement error. PMID:22788754

CHARACTER OF THE CHANGES IN FEAR MOTIVATED DECLARATIVE MEMORY IN THE HIGH IMMOBILIZATION "DEPRESSIVE" RATS.

PubMed

Nachkebia, N; Shavgulidze, M; Babilodze, M; Chkhartishvili, E; Rogava, N

2016-10-01

Present study investigated possible differences in the learning and memory of declarative memory task in rats selected according to the differences in immobilization response that is in high immobilization "depressive" and low immobilization "non-depressive" rats. Understanding the character of learning and memory disturbances in basal conditions of animal models of depression is still very topical for more intimate definition of the pathophysiology of major depressive disorder and appropriate searching the ways of its correction. Experiments were carried out on the adult white wild rats (with the weight 200-250 g, n=20). Selection of rats according to the level of immobilization was made by means of forced swim test. Learning and memory disturbances were studied using passive avoidance test that is fear motivated one trial declarative memory task. It was shown by us that 100% of low immobilization "non-depressive" rats remember painful stimulation and therefore they are not enter in the dark compartment during whole period of observation during testing session. Behavior of high immobilization "depressive" rats is not similar in passive avoidance camera; 50% of "depressive" rats, with long escape latency during training session (92±10 sec), remember painful stimulation during testing session and therefore they are not enter in the dark compartment during whole observation period. The remaining 50%, that are not differ significantly from the low immobility "non-depressive" rats by the latency of escape (5±1 sec) during training session, are not able to remember painful stimulation during testing session and therefore they enter in the dark compartment with shortest escape latency (6±1 sec). In conclusion, high immobility "depressive" rats perform passive avoidance declarative memory task at the chance level that is a direct indicator for the serious disturbances of declarative memory mechanisms in "depressive" rats selected in forced swim test according to the level of immobility.

Age moderates the effect of acute dopamine depletion on passive avoidance learning.

PubMed

Kelm, Mary Katherine; Boettiger, Charlotte Ann

2015-04-01

Despite extensive links between reinforcement-based learning and dopamine (DA), studies to date have not found consistent effects of acute DA reduction on reinforcement learning in both men and women. Here, we tested the effects of reducing DA on reward- and punishment-based learning using the deterministic passive avoidance learning (PAL) task. We tested 16 (5 female) adults (ages 22-40) in a randomized, cross-over design to determine whether reducing global DA by administering an amino acid beverage deficient in the DA precursors, phenylalanine and tyrosine (P/T[-]), would affect PAL task performance. We found that P/T[-] beverage effects on PAL performance were modulated by age. Specifically, we found that P/T depletion significantly improved learning from punishment with increasing participant age. Participants committed 1.49 fewer passive avoidance errors per additional year of age (95% CI, -0.71 - -2.27, r=-0.74, p=0.001). Moreover, P/T depletion improved learning from punishment in adults (ages 26-40) while it impaired learning from punishment in emerging adults (ages 22-25). We observed similar, but non-significant trends in learning from reward. While there was no overall effect of P/T-depletion on reaction time (RT), there was a relationship between the effect of P/T depletion on PAL performance and RT; those who responded more slowly on the P/T[-] beverage also made more errors on the P/T[-] beverage. When P/T-depletion slowed RT after a correct response, there was a worsening of PAL task performance; there was no similar relationship for the RT after an incorrect response and PAL task performance. Moreover, among emerging adults, changes in mood on the P/T[-] beverage negatively correlated with learning from reward on the P/T[-] beverage. Together, we found that both reward- and punishment-based learning are sensitive to central catecholamine levels, and that these effects of acute DA reduction vary with age. Copyright © 2015 Elsevier Inc. All rights reserved.

Bisphenol-A rapidly enhanced passive avoidance memory and phosphorylation of NMDA receptor subunits in hippocampus of young rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu Xiaohong, E-mail: xuxh63@zjnu.cn; Li Tao; Luo Qingqing

Bisphenol-A (BPA), an endocrine disruptor, is found to influence development of brain and behaviors in rodents. The previous study indicated that perinatal exposure to BPA impaired learning-memory and inhibited N-methyl-D-aspartate receptor (NMDAR) subunits expressions in hippocampus during the postnatal development in rats; and in cultured hippocampal neurons, BPA rapidly promotes dynamic changes in dendritic morphology through estrogen receptor-mediated pathway by concomitant phosphorylation of NMDAR subunit NR2B. In the present study, we examined the rapid effect of BPA on passive avoidance memory and NMDAR in the developing hippocampus of Sprague-Dawley rats at the age of postnatal day 18. The results showedmore » that BPA or estradiol benzoate (EB) rapidly extended the latency to step down from the platform 1 h after footshock and increased the phosphorylation levels of NR1, NR2B, and mitogen-activated extracellular signal-regulated kinase (ERK) in hippocampus within 1 h. While 24 h after BPA or EB treatment, the improved memory and the increased phosphorylation levels of NR1, NR2B, ERK disappeared. Furthermore, pre-treatment with an estrogen receptors (ERs) antagonist, ICI182,780, or an ERK-activating kinase inhibitor, U0126, significantly attenuated EB- or BPA-induced phosphorylations of NR1, NR2B, and ERK within 1 h. These data suggest that BPA rapidly enhanced short-term passive avoidance memory in the developing rats. A non-genomic effect via ERs may mediate the modulation of the phosphorylation of NMDAR subunits NR1 and NR2B through ERK signaling pathway. - Highlights: > BPA rapidly extended the latency to step down from platform 1 h after footshock. > BPA rapidly increased pNR1, pNR2B, and pERK in hippocampus within 1 h. > ERs antagonist or MEK inhibitor attenuated BPA-induced pNR1, pNR2B, and pERK.« less

Effects of novel tacrine-related cholinesterase inhibitors in the reversal of 3-quinuclidinyl benzilate-induced cognitive deficit in rats--Is there a potential for Alzheimer's disease treatment?

PubMed

Misik, Jan; Korabecny, Jan; Nepovimova, Eugenie; Kracmarova, Alzbeta; Kassa, Jiri

2016-01-26

Inhibitors of cholinesterase are important drugs for therapy of Alzheimer's disease and the search for new modifications is extensive, including dual inhibitors or multi-target hybrid compounds. The aim of the present study was a preliminary evaluation of pro-cognitive effects of newly-developed 7-MEOTA-donepezil like hybrids (compounds no. 1 and 2) and N-alkylated tacrine derivatives (compounds no. 3 and 4) using an animal model of pharmacologically-induced cognitive deficit. Male Wistar rats were subjected to tests of learning and memory in a water maze and step-through passive avoidance task. Cognitive impairment was induced by 3-quinuclidinyl benzilate (QNB, 2mgkg(-1)), administered intraperitoneally 1h before training sessions. Cholinesterase inhibitors were administered as a single therapeutic dose following the QNB at 30min at the following dose rates; 1 (25.6mgkg(-1)), 2 (12.3mgkg(-1)), 3 (5.7mgkg(-1)), 4 (5.2mgkg(-1)). The decrease in total path within the 10-swim session (water maze), the preference for target quadrant (water maze) and the entrance latency (passive avoidance) were taken as indicators of learning ability in rats. The effects of novel compounds were compared to that of standards tacrine (5.2mgkg(-1)) and donepezil (2.65mgkg(-1)). QNB significantly impaired spatial navigation as well as fear learning. Generally, the performance of rats was improved when treated with novel inhibitors and this effect reached efficiency of standard donepezil at selected doses. There was a significant improvement in the groups treated with compounds 2 and 3 in all behavioral tasks. The rest of the novel compounds succeed in the passive avoidance test. In summary, the potential of novel inhibitors (especially compounds 2 and 3) was proved and further detailed evaluation of these compounds as potential drugs for Alzheimer's disease treatment is proposed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Obstacle-avoiding robot with IR and PIR motion sensors

NASA Astrophysics Data System (ADS)

Ismail, R.; Omar, Z.; Suaibun, S.

2016-10-01

Obstacle avoiding robot was designed, constructed and programmed which may be potentially used for educational and research purposes. The developed robot will move in a particular direction once the infrared (IR) and the PIR passive infrared (PIR) sensors sense a signal while avoiding the obstacles in its path. The robot can also perform desired tasks in unstructured environments without continuous human guidance. The hardware was integrated in one application board as embedded system design. The software was developed using C++ and compiled by Arduino IDE 1.6.5. The main objective of this project is to provide simple guidelines to the polytechnic students and beginners who are interested in this type of research. It is hoped that this robot could benefit students who wish to carry out research on IR and PIR sensors.

Higher threat avoidance costs reduce avoidance behaviour which in turn promotes fear extinction in humans.

PubMed

Rattel, Julina A; Miedl, Stephan F; Blechert, Jens; Wilhelm, Frank H

2017-09-01

Theoretical models specifying the underlying mechanisms of the development and maintenance of anxiety and related disorders state that fear responses acquired through classical Pavlovian conditioning are maintained by repeated avoidance behaviour; thus, it is assumed that avoidance prevents fear extinction. The present study investigated behavioural avoidance decisions as a function of avoidance costs in a naturalistic fear conditioning paradigm. Ecologically valid avoidance costs - manipulated between participant groups - were represented via time-delays during a detour in a gamified computer task. After differential acquisitions of shock-expectancy to a predictive conditioned stimulus (CS+), participants underwent extinction where they could either take a risky shortcut, while anticipating shock signaled by the CS+, or choose a costly avoidance option (lengthy detour); thus, they were faced with an approach-avoidance conflict. Groups with higher avoidance costs (longer detours) showed lower proportions of avoiders. Avoiders gave heightened shock-expectancy ratings post-extinction, demonstrating 'protecting from extinction', i.e. failure to extinguish. Moreover, there was an indirect effect of avoidance costs on protection from extinction through avoidance behaviour. No moderating role of trait-anxiety was found. Theoretical implications of avoidance behaviour are discussed, considering the involvement of instrumental learning in the maintenance of fear responses. Copyright © 2016 Elsevier Ltd. All rights reserved.

Magnetic Field Response Measurement Acquisition System

NASA Technical Reports Server (NTRS)

Woodward, Stanley E. (Inventor); Taylor, Bryant D. (Inventor)

2007-01-01

Magnetic field response sensors designed as passive inductor- capacit or circuits produce magnetic field responses whose harmonic frequenci es correspond to states of physical properties for which the sensors measure. Power to the sensing element is acquired using Faraday induc tion. A radio frequency antenna produces the time varying magnetic fi eld used for powering the sensor, as well as receiving the magnetic field response of the sensor. An interrogation architecture for disce rning changes in sensor's response frequency, resistance and amplitud e is integral to the method thus enabling a variety of measurements. Multiple sensors can be interrogated using this method, thus eliminat ing the need to have a data acquisition channel dedicated to each se nsor. The method does not require the sensors to be in proximity to a ny form of acquisition hardware. A vast array of sensors can be used as interchangeable parts in an overall sensing system.

Modulated Acquisition of Spatial Distortion Maps

PubMed Central

Volkov, Alexey; Gros, Jerneja Žganec; Žganec, Mario; Javornik, Tomaž; Švigelj, Aleš

2013-01-01

This work discusses a novel approach to image acquisition which improves the robustness of captured data required for 3D range measurements. By applying a pseudo-random code modulation to sequential acquisition of projected patterns the impact of environmental factors such as ambient light and mutual interference is significantly reduced. The proposed concept has been proven with an experimental range sensor based on the laser triangulation principle. The proposed design can potentially enhance the use of this principle to a variety of outdoor applications, such as autonomous vehicles, pedestrians' safety, collision avoidance, and many other tasks, where robust real-time distance detection in real world environment is crucial. PMID:23966196

Modulated acquisition of spatial distortion maps.

PubMed

Volkov, Alexey; Gros, Jerneja Zganec; Zganec, Mario; Javornik, Tomaž; Svigelj, Aleš

2013-08-21

This work discusses a novel approach to image acquisition which improves the robustness of captured data required for 3D range measurements. By applying a pseudo-random code modulation to sequential acquisition of projected patterns the impact of environmental factors such as ambient light and mutual interference is significantly reduced. The proposed concept has been proven with an experimental range sensor based on the laser triangulation principle. The proposed design can potentially enhance the use of this principle to a variety of outdoor applications, such as autonomous vehicles, pedestrians' safety, collision avoidance, and many other tasks, where robust real-time distance detection in real world environment is crucial.

Photo-stability and time-resolved photoluminescence study of colloidal CdSe/ZnS quantum dots passivated in Al{sub 2}O{sub 3} using atomic layer deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Chih-Yi; Mao, Ming-Hua, E-mail: mhmao@ntu.edu.tw; Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan

2016-08-28

We report photo-stability enhancement of colloidal CdSe/ZnS quantum dots (QDs) passivated in Al{sub 2}O{sub 3} thin film using the atomic layer deposition (ALD) technique. 62% of the original peak photoluminescence (PL) intensity remained after ALD. The photo-oxidation and photo-induced fluorescence enhancement effects of both the unpassivated and passivated QDs were studied under various conditions, including different excitation sources, power densities, and environment. The unpassivated QDs showed rapid PL degradation under high excitation due to strong photo-oxidation in air while the PL intensity of Al{sub 2}O{sub 3} passivated QDs was found to remain stable. Furthermore, recombination dynamics of the unpassivated andmore » passivated QDs were investigated by time-resolved measurements. The average lifetime of the unpassivated QDs decreases with laser irradiation time due to photo-oxidation. Photo-oxidation creates surface defects which reduces the QD emission intensity and enhances the non-radiative recombination rate. From the comparison of PL decay profiles of the unpassivated and passivated QDs, photo-oxidation-induced surface defects unexpectedly also reduce the radiative recombination rate. The ALD passivation of Al{sub 2}O{sub 3} protects QDs from photo-oxidation and therefore avoids the reduction of radiative recombination rate. Our experimental results demonstrated that passivation of colloidal QDs by ALD is a promising method to well encapsulate QDs to prevent gas permeation and to enhance photo-stability, including the PL intensity and carrier lifetime in air. This is essential for the applications of colloidal QDs in light-emitting devices.« less

Passive acquisition of CLIPS rules

NASA Technical Reports Server (NTRS)

Kovarik, Vincent J., Jr.

1991-01-01

The automated acquisition of knowledge by machine has not lived up to expectations, and knowledge engineering remains a human intensive task. Part of the reason for the lack of success is the difference in the cognitive focus of the expert. The expert must shift his or her focus from the subject domain to that of the representation environment. In doing so this cognitive shift introduces opportunity for errors and omissions. Presented here is work that observes the expert interact with a simulation of the domain. The system logs changes in the simulation objects and the expert's actions in response to those changes. This is followed by the application of inductive reasoning to move the domain specific rules observed to general domain rules.

Estimating pharmacy level prescription drug acquisition costs for third-party reimbursement.

PubMed

Kreling, D H; Kirk, K W

1986-07-01

Accurate payment for the acquisition costs of drug products dispensed is an important consideration in a third-party prescription drug program. Two alternative methods of estimating these costs among pharmacies were derived and compared. First, pharmacists were surveyed to determine the purchase discounts offered to them by wholesalers. A 10.00% modal and 11.35% mean discount resulted for 73 responding pharmacists. Second, cost-plus percents derived from gross profit margins of wholesalers were calculated and applied to wholesaler product costs to estimate pharmacy level acquisition costs. Cost-plus percents derived from National Median and Southwestern Region wholesaler figures were 9.27% and 10.10%, respectively. A comparison showed the two methods of estimating acquisition costs would result in similar acquisition cost estimates. Adopting a cost-plus estimating approach is recommended because it avoids potential pricing manipulations by wholesalers and manufacturers that would negate improvements in drug product reimbursement accuracy.

A simple acquisition strategy to avoid off-resonance blurring in spiral imaging with redundant spiral-in/out k-space trajectories

PubMed Central

Fielden, Samuel W.; Meyer, Craig H.

2014-01-01

Purpose The major hurdle to widespread adoption of spiral trajectories has been their poor off-resonance performance. Here we present a self-correcting spiral k-space trajectory that avoids much of the well-known spiral blurring during data acquisition. Theory and Methods In comparison with a traditional spiral-out trajectory, the spiral-in/out trajectory has improved off-resonance performance. By combining two spiral-in/out acquisitions, one rotated 180° in k-space compared to the other, multi-shot spiral-in/out artifacts are eliminated. A phantom was scanned with the center frequency manually tuned 20, 40, 80, and 160 Hz off-resonance with both a spiral-out gradient echo sequence and the redundant spiral-in/out sequence. The phantom was also imaged in an oblique orientation in order to demonstrate improved concomitant gradient field performance of the sequence, and was additionally incorporated into a spiral turbo spin echo sequence for brain imaging. Results Phantom studies with manually-tuned off-resonance agree well with theoretical calculations, showing that moderate off-resonance is well-corrected by this acquisition scheme. Blur due to concomitant fields is reduced, and good results are obtained in vivo. Conclusion The redundant spiral-in/out trajectory results in less image blur for a given readout length than a traditional spiral-out scan, reducing the need for complex off-resonance correction algorithms. PMID:24604539

A simple acquisition strategy to avoid off-resonance blurring in spiral imaging with redundant spiral-in/out k-space trajectories.

PubMed

Fielden, Samuel W; Meyer, Craig H

2015-02-01

The major hurdle to widespread adoption of spiral trajectories has been their poor off-resonance performance. Here we present a self-correcting spiral k-space trajectory that avoids much of the well-known spiral blurring during data acquisition. In comparison with a traditional spiral-out trajectory, the spiral-in/out trajectory has improved off-resonance performance. By combining two spiral-in/out acquisitions, one rotated 180° in k-space compared with the other, multishot spiral-in/out artifacts are eliminated. A phantom was scanned with the center frequency manually tuned 20, 40, 80, and 160 Hz off-resonance with both a spiral-out gradient echo sequence and the redundant spiral-in/out sequence. The phantom was also imaged in an oblique orientation in order to demonstrate improved concomitant gradient field performance of the sequence. Additionally, the trajectory was incorporated into a spiral turbo spin echo sequence for brain imaging. Phantom studies with manually tuned off-resonance agree well with theoretical calculations, showing that moderate off-resonance is well-corrected by this acquisition scheme. Blur due to concomitant fields is reduced, and good results are obtained in vivo. The redundant spiral-in/out trajectory results in less image blur for a given readout length than a traditional spiral-out scan, reducing the need for complex off-resonance correction algorithms. © 2014 Wiley Periodicals, Inc.

Performance optimization of the Varian aS500 EPID system.

PubMed

Berger, Lucie; François, Pascal; Gaboriaud, Geneviève; Rosenwald, Jean-Claude

2006-01-01

Today, electronic portal imaging devices (EPIDs) are widely used as a replacement to portal films for patient position verification, but the image quality is not always optimal. The general aim of this study was to optimize the acquisition parameters of an amorphous silicon EPID commercially available for clinical use in radiation therapy with the view to avoid saturation of the system. Special attention was paid to selection of the parameter corresponding to the number of rows acquired between accelerator pulses (NRP) for various beam energies and dose rates. The image acquisition system (IAS2) has been studied, and portal image acquisition was found to be strongly dependent on the accelerator pulse frequency. This frequency is set for each "energy - dose rate" combination of the linear accelerator. For all combinations, the image acquisition parameters were systematically changed to determine their influence on the performances of the Varian aS500 EPID system. New parameters such as the maximum number of rows (MNR) and the number of pulses per frame (NPF) were introduced to explain portal image acquisition theory. Theoretical and experimental values of MNR and NPF were compared, and they were in good agreement. Other results showed that NRP had a major influence on detector saturation and dose per image. A rule of thumb was established to determine the optimum NRP value to be used. This practical application was illustrated by a clinical example in which the saturation of the aSi EPID was avoided by NRP optimization. Moreover, an additional study showed that image quality was relatively insensitive to this parameter.

Exposure to Novelty Weakens Conditioned Fear in Long-Evans Rats

ERIC Educational Resources Information Center

Anderson, Matthew J.; Burpee, Tara E.; Wall, Matthew J.; McGraw, Justin J.

2013-01-01

The present study sought to determine whether post-training exposure to a novel or familiar object, encountered in either the location of the original fear conditioning (black compartment of a passive avoidance {PA} chamber) or in a neutral setting (open field where initial object training had occurred) would prove capable of reducing fear at…

Teachers' Perception of Their Principal's Leadership Style and the Effects on Student Achievement in Improving and Non-Improving Schools

ERIC Educational Resources Information Center

Hardman, Brenda Kay

2011-01-01

Teachers' perceptions of their school leaders influence student achievement in their schools. The extent of this influence is examined in this study. This quantitative study examined teachers' perceptions of the leadership style of their principals as transformational, transactional or passive-avoidant in improving and non-improving schools in…

The Inevitability of Conflict and the Importance of Its Resolution in Christian Higher Education

ERIC Educational Resources Information Center

Ennis, Leslie Sturdivant

2008-01-01

Among Christian adherents, the subject of conflict and its proper resolution has been a source of misunderstanding and angst for centuries. New Testament admonitions concerning the proper Christian life have traditionally focused on passivism and have been interpreted broadly by Christendom to require avoidance of all conflict as a virtue. The…

Lindera melissifolia responses to flood durations and light regimes suggest strategies for recovery and conservation

Treesearch

Brian Roy Lockhart; Emile S. Gardiner; Theodor D. Leininger; Paul B. Hamel; Kristina F. Connor; Margaret S. Devall; Nathan M. Schiff; A. Dan Wilson

2013-01-01

Passive management to preserve endangered plant species involves measures to avoid anthropogenic disturbance of natural populations, but this approach may not sustain plants that require disturbance-maintained habitats. Active management is often necessary to maintain existing habitats or provide new habitats for endangered species recovery. Our objective was to...

The integrated role of ACh, ERK and mTOR in the mechanisms of hippocampal inhibitory avoidance memory.

PubMed

Giovannini, Maria Grazia; Lana, Daniele; Pepeu, Giancarlo

2015-03-01

The purpose of this review is to summarize the present knowledge on the interplay among the cholinergic system, Extracellular signal-Regulated Kinase (ERK) and Mammalian Target of Rapamycin (mTOR) pathways in the development of short and long term memories during the acquisition and recall of the step-down inhibitory avoidance in the hippocampus. The step-down inhibitory avoidance is a form of associative learning that is acquired in a relatively simple one-trial test through several sensorial inputs. Inhibitory avoidance depends on the integrated activity of hippocampal CA1 and other brain areas. Recall can be performed at different times after acquisition, thus allowing for the study of both short and long term memory. Among the many neurotransmitter systems involved, the cholinergic neurons that originate in the basal forebrain and project to the hippocampus are of crucial importance in inhibitory avoidance processes. Acetylcholine released from cholinergic fibers during acquisition and/or recall of behavioural tasks activates muscarinic and nicotinic acetylcholine receptors and brings about a long-lasting potentiation of the postsynaptic membrane followed by downstream activation of intracellular pathway (ERK, among others) that create conditions favourable for neuronal plasticity. ERK appears to be salient not only in long term memory, but also in the molecular mechanisms underlying short term memory formation in the hippocampus. Since ERK can function as a biochemical coincidence detector in response to extracellular signals in neurons, the activation of ERK-dependent downstream effectors is determined, in part, by the duration of ERK phosphorylation itself. Long term memories require protein synthesis, that in the synapto-dendritic compartment represents a direct mechanism that can produce rapid changes in protein content in response to synaptic activity. mTOR in the brain regulates protein translation in response to neuronal activity, thereby modulating synaptic plasticity and long term memory formation. Some studies demonstrate a complex interplay among the cholinergic system, ERK and mTOR. It has been shown that co-activation of muscarinic acetylcholine receptors and β-adrenergic receptors facilitates the conversion of short term to long term synaptic plasticity through an ERK- and mTOR-dependent mechanism which requires translation initiation. It seems therefore that the complex interplay among the cholinergic system, ERK and mTOR is crucial in the development of new inhibitory avoidance memories in the hippocampus. Copyright © 2015 Elsevier Inc. All rights reserved.

Fully Passive Wireless Acquisition of Neuropotentials

NASA Astrophysics Data System (ADS)

Schwerdt, Helen N.

The ability to monitor electrophysiological signals from the sentient brain is requisite to decipher its enormously complex workings and initiate remedial solutions for the vast amount of neurologically-based disorders. Despite immense advancements in creating a variety of instruments to record signals from the brain, the translation of such neurorecording instrumentation to real clinical domains places heavy demands on their safety and reliability, both of which are not entirely portrayed by presently existing implantable recording solutions. In an attempt to lower these barriers, alternative wireless radar backscattering techniques are proposed to render the technical burdens of the implant chip to entirely passive neurorecording processes that transpire in the absence of formal integrated power sources or powering schemes along with any active circuitry. These radar-like wireless backscattering mechanisms are used to conceive of fully passive neurorecording operations of an implantable microsystem. The fully passive device potentially manifests inherent advantages over current wireless implantable and wired recording systems: negligible heat dissipation to reduce risks of brain tissue damage and minimal circuitry for long term reliability as a chronic implant. Fully passive neurorecording operations are realized via intrinsic nonlinear mixing properties of the varactor diode. These mixing and recording operations are directly activated by wirelessly interrogating the fully passive device with a microwave carrier signal. This fundamental carrier signal, acquired by the implant antenna, mixes through the varactor diode along with the internal targeted neuropotential brain signals to produce higher frequency harmonics containing the targeted neuropotential signals. These harmonics are backscattered wirelessly to the external interrogator that retrieves and recovers the original neuropotential brain signal. The passive approach removes the need for internal power sources and may alleviate heat trauma and reliability issues that limit practical implementation of existing implantable neurorecorders.

Folding Elastic Thermal Surface - FETS

NASA Technical Reports Server (NTRS)

Urquiza, Eugenio; Zhang, Burt X.; Thelen, Michael P.; Rodriquez, Jose I.; Pellegrino, Sergio

2013-01-01

The FETS is a light and compact thermal surface (sun shade, IR thermal shield, cover, and/or deployable radiator) that is mounted on a set of offset tape-spring hinges. The thermal surface is constrained during launch and activated in space by a thermomechanical latch such as a wax actuator. An application-specific embodiment of this technology developed for the MATMOS (Mars Atmospheric Trace Molecule Occultation Spectrometer) project serves as a deployable cover and thermal shield for its passive cooler. The FETS fits compactly against the instrument within the constrained launch envelope, and then unfolds into a larger area once in space. In this application, the FETS protects the passive cooler from thermal damage and contamination during ground operations, launch, and during orbit insertion. Once unfolded or deployed, the FETS serves as a heat shield, intercepting parasitic heat loads by blocking the passive cooler s view of the warm spacecraft. The technology significantly enhances the capabilities of instruments requiring either active or passive cooling of optical detectors. This can be particularly important for instruments where performance is limited by the available radiator area. Examples would be IR optical instruments on CubeSATs or those launched as hosted payloads because radiator area is limited and views are often undesirable. As a deployable radiator, the panels making up the FETS are linked thermally by thermal straps and heat pipes; the structural support and deployment energy is provided using tape-spring hinges. The FETS is a novel combination of existing technologies. Prior art for deployable heat shields uses rotating hinges that typically must be lubricated to avoid cold welding or static friction. By using tape-spring hinges, the FETS avoids the need for lubricants by avoiding friction altogether. This also eliminates the potential for contamination of nearby cooled optics by outgassing lubricants. Furthermore, the tape-spring design of the FETS is also self-locking so the panels stay in a rigid and extended configuration after deployment. This unexpected benefit makes the tape-spring hinge design of the FETS a light, simple, reliable, compact, non-outgassing hinge, spring, and latch. While tape-spring hinges are not novel, they have never been used to deploy passive unfolding thermal surfaces (radiator panels, covers, sun shades, or IR thermal shields). Furthermore, because this technology is compact, it has minimal impact on the launch envelope and mass specifications. FETS enhances the performance of hosted payload instruments where the science data is limited by dark noise. Incorporating FETS into a thermal control system increases radiator area, which lowers the optical detector temperature. This results in higher SNR (signal-to-noise ratio) and improved science data.

Food Avoidance Learning in Squirrel Monkeys and Common Marmosets

PubMed Central

Laska, Matthias; Metzker, Karin

1998-01-01

Using a conditioned food avoidance learning paradigm, six squirrel monkeys (Saimiri sciureus) and six common marmosets (Callithrix jacchus) were tested for their ability to (1) reliably form associations between visual or olfactory cues of a potential food and its palatability and (2) remember such associations over prolonged periods of time. We found (1) that at the group level both species showed one-trial learning with the visual cues color and shape, whereas only the marmosets were able to do so with the olfactory cue, (2) that all individuals from both species learned to reliably avoid the unpalatable food items within 10 trials, (3) a tendency in both species for quicker acquisition of the association with the visual cues compared with the olfactory cue, (4) a tendency for quicker acquisition and higher reliability of the aversion by the marmosets compared with the squirrel monkeys, and (5) that all individuals from both species were able to reliably remember the significance of the visual cues, color and shape, even after 4 months, whereas only the marmosets showed retention of the significance of the olfactory cues for up to 4 weeks. Furthermore, the results suggest that in both species tested, illness is not a necessary prerequisite for food avoidance learning but that the presumably innate rejection responses toward highly concentrated but nontoxic bitter and sour tastants are sufficient to induce robust learning and retention. PMID:10454364

Behavioral consequences of predator stress in the rat elevated T-maze.

PubMed

Bulos, Erika Mondin; Pobbe, Roger Luis Henschel; Zangrossi, Helio

2015-07-01

Analyses of the behavioral reactions of rodents to predators have greatly contributed to the understanding of defense-related human psychopathologies such as anxiety and panic.We here investigated the behavioral consequences of exposing male Wistar rats to a live cat using the elevated T-maze test of anxiety. This test allows the measurement of two defensive responses: inhibitory avoidance and escape, which in terms of pathology have been associated with generalized anxiety and panic disorders, respectively. For comparative reasons, the effects of exposure to the cat were also assessed in the elevated plus-maze. The results showed that a 5-min exposure to the cat selectively facilitated inhibitory avoidance acquisition, an anxiogenic effect, without affecting escape expression in the elevated T-maze. This was seen immediately but not 30 min after contact with the predator. This short-lived anxiogenic effect was also detected in the elevated plus-maze. Previous administration of the benzodiazepine anxiolytic diazepam (2 mg/kg) decreased the immediate avoidance response to the predator and the neophobic reaction to a dummy cat used as a control stimulus. The drug also impaired inhibitory avoidance acquisition in the elevated T-maze, indicating an anxiolytic effect, without affecting escape performance. The results indicate that the state of anxiety evoked during contact with the predator generalizes to both elevated plus- and T-mazes, impacting on defensive responses associated with generalized anxiety disorder.

Multiple trial inhibitory avoidance acquisition and retrieval are resistant to chronic stress.

PubMed

Raya, J; Girardi, C E N; Esumi, L A; Ferreira, L B T; Hipólide, D C

2018-02-01

Chronic mild stress (CMS) is a widely accepted animal model relevant to depression that among other consequences, is chiefly known to induce anhedonia, often assessed as decreased preference for sucrose solution. CMS is also known to affect cognition, particularly memory tasks. In this study we have employed the multiple-trial inhibitory avoidance memory task (MTIA) to assess CMS effects on memory acquisition and retrieval. MTIA consists of repeated exposures to the unconditioned stimulus until a learning criterion is reached. Wistar rats underwent CMS for 5 weeks, and sucrose consumption was assessed once a week. At the end of CMS, animals were evaluated in the MTIA task. Overall decreased sucrose solution preference was highly variable. Further analyses showed that a subset of animals expressed resilience while another subset was sensitive to stress. CMS did not affect the number of acquisition sessions before reaching criterion or retrieval latency of MTIA task in neither sensitive nor resilient groups. Although tasks that assess learning ability in animal models relevant to depression indicate cognitive deficits, the ability to learn the association between compartment crossing and the aversive electric foot shock, which is strongly dependent on emotional aspects, was intact. Copyright © 2017 Elsevier B.V. All rights reserved.

Somatic Arc protein expression in hippocampal granule cells is increased in response to environmental change but independent of task-specific learning.

PubMed

Cleland, J P; Willis, E F; Bartlett, P F; Vukovic, J

2017-09-29

Activated neurons express immediate-early genes, such as Arc. Expression of Arc in the hippocampal granule cell layer, an area crucial for spatial learning and memory, is increased during acquisition of spatial learning; however, it is unclear whether this effect is related to the task-specific learning process or to nonspecific aspects of the testing procedure (e.g. exposure to the testing apparatus and exploration of the environment). Herein, we show that Arc-positive cells numbers are increased to the same extent in the granule cell layer after both acquisition of a single spatial learning event in the active place avoidance task and exploration of the testing environment, as compared to naïve (i.e. caged) mice. Repeated exposure the testing apparatus and environment did not reduce Arc expression. Furthermore, Arc expression did not correlate with performance in both adult and aged animals, suggesting that exploration of the testing environment, rather than the specific acquisition of the active place avoidance task, induces Arc expression in the dentate granule cell layer. These findings thus suggest that Arc is an experience-induced immediate-early gene.

Airborne Remote Observations of L-Band Radio Frequency Interference and Implications for Satellite Missions

NASA Technical Reports Server (NTRS)

Laymon, Charles; Srinivasan, Karthik; Limaye, Ashutosh

2011-01-01

Passive remote sensing of the Earth s surface and atmosphere from space has significant importance in operational and research environmental studies, in particular for the scientific understanding, monitoring and prediction of climate change and its impacts. Passive remote sensing requires the measurement of naturally occurring radiations, usually of very low power levels, which contain essential information on the physical process under investigation. As such, these sensed radio frequency bands are a unique natural resource enabling space borne passive sensing of the atmosphere and the Earth s surface that deserves adequate allocation to the Earth Exploration Satellite Service and absolute protection from interference. Unfortunately, radio frequency interference (RFI) is an increasing problem for Earth remote sensing, particularly for passive observations of natural emissions. Because these natural signals tend to be very weak, even low levels of interference received by a passive sensor may degrade the fidelity of scientific data. The characteristics of RFI (low-level interference and radar-pulse noise) are not well known because there has been no systematic surveillance, spectrum inventory or mapping of RFI. While conducting a flight experiment over central Tennessee in May 2010, RFI, a concern for any instrument operating in the passive L band frequency, was observed across 16 subbands between 1402-1427 MHz. Such a survey provides rare characterization data from which to further develop mitigation technologies as well as to identify bandwidths to avoid in future sensor formulation.

Independent and joint exposure to passive smoking and cooking oil fumes on oral cancer in Chinese women: a hospital-based case-control study.

PubMed

He, Baochang; Chen, Fa; Yan, Lingjun; Huang, Jiangfeng; Liu, Fangping; Qiu, Yu; Lin, Lisong; Zhang, Zuofeng; Cai, Lin

2016-10-01

Passive smoking and COF exposure are independent risk factors for oral cancer in Chinese women, with the multiplicative interactions from combined exposures. Avoiding exposure to environmental tobacco smoke and COF may contribute to the prevention of oral cancer in Chinese women. To evaluate the independent and joint effects of passive smoking and cooking oil fumes (COF) on oral cancer in Chinese women. A case-control study was performed including 238 female patients with pathologically confirmed oral cancer and 470 controls as age-matched controls. Face-to-face interviews were conducted based on a structured questionnaire. The effects of passive smoking and COF exposure were analyzed using non-conditional logistic regression models. Passive smoking significantly increased the risk of oral cancer in Chinese women: adjusted ORs were 2.12 (95% CI = 1.11-4.07) for those only exposed before age 18, 1.52 (95% CI = 1.01-2.31) for those only exposed after age 18, and 2.38 (95% CI = 1.47-3.85) for those both exposed before and after age 18. In addition, COF exposure was significantly associated with a risk of oral cancer (adjusted ORs were 1.69 (95% CI = 1.03-2.78) for light exposure and 2.06 (95% CI = 1.21-3.50) for heavy exposure). Furthermore, there was a significantly multiplicative interaction between passive smoking and COF for oral cancer.

Enhancing hazard avoidance in teen-novice riders.

PubMed

Vidotto, Giulio; Bastianelli, Alessia; Spoto, Andrea; Sergeys, Filip

2011-01-01

Research suggests that novice drivers' safety performance is inferior to that of experienced drivers in different ways. One of the most critical skills related to accident avoidance by a novice driver is the detection, recognition and reaction to traffic hazards; it is called hazard perception and is defined as the ability to identify potentially dangerous traffic situations. The focus of this research is to assess how far a motorcycle simulator could improve hazard avoidance skills in teenagers. Four hundred and ten participants (207 in the experimental group and 203 in the control group) took part in this research. Results demonstrated that the mean proportion of avoided hazards increases as a function of the number of tracks performed in the virtual training. Participants of the experimental group after the training had a better proportion of avoided hazards than participants of the control group with a passive training based on a road safety lesson. Results provide good evidence that training with the simulator increases the number of avoided accidents in the virtual environment. It would be reasonable to explain this improvement by a higher level of hazard perception skills. Copyright © 2010 Elsevier Ltd. All rights reserved.

A self-regulation perspective on avoidance and persistence behavior in chronic pain: new theories, new challenges?

PubMed

Van Damme, Stefaan; Kindermans, Hanne

2015-02-01

Behavioral factors such as avoidance and persistence have received massive theoretical and empirical attention in the attempts to explain chronic pain and disability. The determinants of these pain behaviors remain, however, poorly understood. We propose a self-regulation perspective to increase our understanding of pain-related avoidance and persistence. A narrative review. We identified several theoretical views that may help explaining avoidance and persistence behavior, and organized these views around 4 concepts central in self-regulation theories: (1) identity, (2) affective-motivational orientation, (3) goal cognitions, and (4) coping. The review shows that each of these self-regulation perspectives allows for a broadened view in which pain behaviors are not simply considered passive consequences of fear, but proactive strategies to regulate the self when challenged by pain. Several implications and challenges arising from this review are discussed. In particular, a self-regulation perspective does not consider avoidance and persistence behavior to be intrinsically adaptive or maladaptive, but argues that their effects on disability and well-being rather depend on the goals underlying these behaviors. Such view would require a shift in how avoidance and persistence behavior are assessed and approached in clinical interventions.

Proline-containing dipeptide GVS-111 retains nootropic activity after oral administration.

PubMed

Ostrovskaya, R U; Mirsoev, T K; Romanova, G A; Gudasheva, T A; Kravchenko, E V; Trofimov, C C; Voronina, T A; Seredenin, S B

2001-10-01

Experiments on rats trained passive avoidance task showed that N-phenyl-acetyl-L-prolyl-glycyl ethyl ester, peptide analog of piracetam (GVS-111, Noopept) after oral administration retained antiamnesic activity previously observed after its parenteral administration. Effective doses were 0.5-10 mg/kg. Experiments on a specially-developed model of active avoidance (massive one-session learning schedule) showed that GVS-111 stimulated one-session learning after single administration, while after repeated administration it increased the number of successful learners among those animals who failed after initial training. In this respect, GVS-111 principally differs from its main metabolite cycloprolylglycine and standard nootropic piracetam.

Dense range map reconstruction from a versatile robotic sensor system with an active trinocular vision and a passive binocular vision.

PubMed

Kim, Min Young; Lee, Hyunkee; Cho, Hyungsuck

2008-04-10

One major research issue associated with 3D perception by robotic systems is the creation of efficient sensor systems that can generate dense range maps reliably. A visual sensor system for robotic applications is developed that is inherently equipped with two types of sensor, an active trinocular vision and a passive stereo vision. Unlike in conventional active vision systems that use a large number of images with variations of projected patterns for dense range map acquisition or from conventional passive vision systems that work well on specific environments with sufficient feature information, a cooperative bidirectional sensor fusion method for this visual sensor system enables us to acquire a reliable dense range map using active and passive information simultaneously. The fusion algorithms are composed of two parts, one in which the passive stereo vision helps active vision and the other in which the active trinocular vision helps the passive one. The first part matches the laser patterns in stereo laser images with the help of intensity images; the second part utilizes an information fusion technique using the dynamic programming method in which image regions between laser patterns are matched pixel-by-pixel with help of the fusion results obtained in the first part. To determine how the proposed sensor system and fusion algorithms can work in real applications, the sensor system is implemented on a robotic system, and the proposed algorithms are applied. A series of experimental tests is performed for a variety of configurations of robot and environments. The performance of the sensor system is discussed in detail.

Developing Coping Typologies of Minority Adolescents: A Latent Profile Analysis

PubMed Central

Aldridge, Arianna A.; Roesch, Scott C.

2008-01-01

Latent profile analysis (LPA) was used to develop a coping typology of minority adolescents (M = 15.5 yrs). A multiethnic sample (n = 354) was recruited from a program aimed at serving low-income students. LPA revealed three distinct coping profiles. The first comprised adolescents who used a number of specific coping strategies at a low level (Low Generic Copers). The second comprised adolescents who emphasized active/approach strategies (e.g., planning; Active Copers). The third comprised adolescents who emphasized avoidant/passive strategies (e.g., substance abuse; Avoidant Copers). Active Copers experienced significantly less depression and more stress-related growth than Low Generic Copers. Low Generic Copers experienced significantly less depression than Avoidant Copers but also significantly less stress-related growth than Active Copers. Discussion focuses on integrating the current typology with traditional coping taxomonies. PMID:17904631

Coping and sickness absence

PubMed Central

Schaufeli, Wilmar B.; van Dijk, Frank J. H.; Blonk, Roland W. B.

2007-01-01

Objectives The aim of this study is to examine the role of coping styles in sickness absence. In line with findings that contrast the reactive–passive focused strategies, problem-solving strategies are generally associated with positive results in terms of well-being and overall health outcomes; our hypothesis is that such strategies are positively related to a low frequency of sickness absence and with short lengths (total number of days absent) and durations (mean duration per spell). Methods Using a prospective design, employees’ (N = 3,628) responses on a self-report coping inventory are used to predict future registered sickness absence (i.e. frequency, length, duration, and median time before the onset of a new sick leave period). Results and conclusions In accordance with our hypothesis, and after adjustment for potential confounders, employees with an active problem-solving coping strategy are less likely to drop out because of sickness absence in terms of frequency, length (longer than 14 days), and duration (more than 7 days) of sickness absence. This positive effect is observed in the case of seeking social support only for the duration of sickness absence and in the case of palliative reaction only for the length and frequency of absence. In contrast, an avoidant coping style, representing a reactive–passive strategy, increases the likelihood of frequent absences significantly, as well as the length and duration of sickness absence. Expression of emotions, representing another reactive–passive strategy, has no effect on future sickness absenteeism. The median time before the onset of a new episode of absenteeism is significantly extended for active problem-solving and reduced for avoidance and for a palliative response. The results of the present study support the notion that problem-solving coping and reactive–passive strategies are inextricably connected to frequency, duration, length and onset of sickness absence. Especially, active problem-solving decreases the chance of future sickness absence. PMID:17701200

Coping and sickness absence.

PubMed

van Rhenen, Willem; Schaufeli, Wilmar B; van Dijk, Frank J H; Blonk, Roland W B

2008-02-01

The aim of this study is to examine the role of coping styles in sickness absence. In line with findings that contrast the reactive-passive focused strategies, problem-solving strategies are generally associated with positive results in terms of well-being and overall health outcomes; our hypothesis is that such strategies are positively related to a low frequency of sickness absence and with short lengths (total number of days absent) and durations (mean duration per spell). Using a prospective design, employees' (N = 3,628) responses on a self-report coping inventory are used to predict future registered sickness absence (i.e. frequency, length, duration, and median time before the onset of a new sick leave period). In accordance with our hypothesis, and after adjustment for potential confounders, employees with an active problem-solving coping strategy are less likely to drop out because of sickness absence in terms of frequency, length (longer than 14 days), and duration (more than 7 days) of sickness absence. This positive effect is observed in the case of seeking social support only for the duration of sickness absence and in the case of palliative reaction only for the length and frequency of absence. In contrast, an avoidant coping style, representing a reactive-passive strategy, increases the likelihood of frequent absences significantly, as well as the length and duration of sickness absence. Expression of emotions, representing another reactive-passive strategy, has no effect on future sickness absenteeism. The median time before the onset of a new episode of absenteeism is significantly extended for active problem-solving and reduced for avoidance and for a palliative response. The results of the present study support the notion that problem-solving coping and reactive-passive strategies are inextricably connected to frequency, duration, length and onset of sickness absence. Especially, active problem-solving decreases the chance of future sickness absence.

Experiences with Acquiring Highly Redundant Spatial Data to Support Driverless Vehicle Technologies

NASA Astrophysics Data System (ADS)

Koppanyi, Z.; Toth, C. K.

2018-05-01

As vehicle technology is moving towards higher autonomy, the demand for highly accurate geospatial data is rapidly increasing, as accurate maps have a huge potential of increasing safety. In particular, high definition 3D maps, including road topography and infrastructure, as well as city models along the transportation corridors represent the necessary support for driverless vehicles. In this effort, a vehicle equipped with high-, medium- and low-resolution active and passive cameras acquired data in a typical traffic environment, represented here by the OSU campus, where GPS/GNSS data are available along with other navigation sensor data streams. The data streams can be used for two purposes. First, high-definition 3D maps can be created by integrating all the sensory data, and Data Analytics/Big Data methods can be tested for automatic object space reconstruction. Second, the data streams can support algorithmic research for driverless vehicle technologies, including object avoidance, navigation/positioning, detecting pedestrians and bicyclists, etc. Crucial cross-performance analyses on map database resolution and accuracy with respect to sensor performance metrics to achieve economic solution for accurate driverless vehicle positioning can be derived. These, in turn, could provide essential information on optimizing the choice of geospatial map databases and sensors' quality to support driverless vehicle technologies. The paper reviews the data acquisition and primary data processing challenges and performance results.

Maternal mobile phone exposure alters intrinsic electrophysiological properties of CA1 pyramidal neurons in rat offspring.

PubMed

Razavinasab, Moazamehosadat; Moazzami, Kasra; Shabani, Mohammad

2016-06-01

Some studies have shown that exposure to electromagnetic field (EMF) may result in structural damage to neurons. In this study, we have elucidated the alteration in the hippocampal function of offspring Wistar rats (n = 8 rats in each group) that were chronically exposed to mobile phones during their gestational period by applying behavioral, histological, and electrophysiological tests. Rats in the EMF group were exposed to 900 MHz pulsed-EMF irradiation for 6 h/day. Whole cell recordings in hippocampal pyramidal cells in the mobile phone groups did show a decrease in neuronal excitability. Mobile phone exposure was mostly associated with a decrease in the number of action potentials fired in spontaneous activity and in response to current injection in both male and female groups. There was an increase in the amplitude of the afterhyperpolarization (AHP) in mobile phone rats compared with the control. The results of the passive avoidance and Morris water maze assessment of learning and memory performance showed that phone exposure significantly altered learning acquisition and memory retention in male and female rats compared with the control rats. Light microscopy study of brain sections of the control and mobile phone-exposed rats showed normal morphology.Our results suggest that exposure to mobile phones adversely affects the cognitive performance of both female and male offspring rats using behavioral and electrophysiological techniques. © The Author(s) 2014.

Developing a Passive Acoustic Monitoring Network for Harbor Porpoise in California

NASA Astrophysics Data System (ADS)

Jacobson, Eiren Kate

Assessing the abundance of and trends in whale, dolphin, and porpoise (cetacean) populations using traditional visual methods can be challenging due primarily to their limited availability at the surface of the ocean. As a result, researchers are increasingly interested in incorporating non-visual and remote observations to improve cetacean population assessments. Passive acoustic monitoring (PAM) can complement or replace visual surveys for cetaceans that produce echolocation clicks, whistles, and other vocalizations. My doctoral dissertation is focused on developing methods to improve PAM of cetaceans. I used the Monterey Bay population of harbor porpoise (Phocoena phocoena ) as a case study for methods development. In Chapter 2, I used passive acoustic data to document that harbor porpoises avoid bottlenose dolphins (Tursiops truncatus) in nearshore Monterey Bay. In Chapter 3, I investigated whether different passive acoustic instruments could be used to monitor harbor porpoise. I recorded harbor porpoise echolocation clicks simultaneously on two different passive acoustic instruments and compared the number and peak frequency of echolocation signals recorded on the two instruments. I found that the number of echolocation clicks was highly correlated between instruments but that the peak frequency of echolocation clicks was not well-correlated, suggesting that some instruments may not be capable of discriminating harbor porpoise echolocation clicks in regions where multiple species with similar echolocation signals are present. In Chapter 4, I used paired visual and passive acoustic surveys to estimate the effective detection area of the passive acoustic sensors in a Bayesian framework. This approach resulted in a posterior distribution of the effective detection area that was consistent with previously published values. In Chapter 5, I used aerial survey and passive acoustic data in a simulation framework to investigate the statistical power of different passive acoustic network designs and hypothetical changes in harbor porpoise abundance. As a whole, this dissertation used an applied approach to methods development to advance the use of PAM for cetaceans.

Spiny lobsters detect conspecific blood-borne alarm cues exclusively through olfactory sensilla.

PubMed

Shabani, Shkelzen; Kamio, Michiya; Derby, Charles D

2008-08-01

When attacked by predators, diverse animals actively or passively release molecules that evoke alarm and related anti-predatory behavior by nearby conspecifics. The actively released molecules are alarm pheromones, whereas the passively released molecules are alarm cues. For example, many insects have alarm-signaling systems that involve active release of alarm pheromones from specialized glands and detection of these signals using specific sensors. Many crustaceans passively release alarm cues, but the nature of the cues, sensors and responses is poorly characterized. Here we show in laboratory and field experiments that injured Caribbean spiny lobsters, Panulirus argus, passively release alarm cues via blood (hemolymph) that induce alarm responses in the form of avoidance and suppression of feeding. These cues are detected exclusively through specific olfactory chemosensors, the aesthetasc sensilla. The alarm cues for Caribbean spiny lobsters are not unique to the species but do show some phylogenetic specificity: P. argus responds primarily with alarm behavior to conspecific blood, but with mixed alarm and appetitive behaviors to blood from the congener Panulirus interruptus, or with appetitive behaviors to blood from the blue crab Callinectes sapidus. This study lays the foundation for future neuroethological studies of alarm cue systems in this and other decapod crustaceans.

Limitations on Ku-band communications due to multipath

NASA Technical Reports Server (NTRS)

Lindsey, J. F.; Rudnicki, J. F.

1977-01-01

The earth and orbiter body reflections involving the Tracking Data Relay Satellite (TDRS)/orbiter communications link are evaluated. Recommendations address operational conditions in order to avoid critical multipath impacts, modulation preferences during acquisition, and preferred scan limit implementation.

Development of amnesia in different mouse strains.

PubMed

Sinovyev, D R; Dubrovina, N I; Kulikov, A V

2009-05-01

We studied passive avoidance retrieval after amnestic stimulation (arrest in unsafe section of the experimental setup) in C57Bl/6J, BALB/c, CBA/Lac, AKR/J, DBA/2J, C3H/HeJ, and ASC/Icg mice. We demonstrated resistance to amnestic stimulation in mice with high predisposition to freezing reaction (ASC/Icg) and memory deficit in other mouse strains.

Cognitive-enhancing effects of hydrolysate of polygalasaponin in SAMP8 mice*

PubMed Central

Xu, Pan; Xu, Shu-ping; Wang, Ke-zhu; Lu, Cong; Zhang, Hong-xia; Pan, Rui-le; Qi, Chang; Yang, Yan-yan; Li, Ying-hui; Liu, Xin-min

2016-01-01

Objectives: The aim of the study is to evaluate the cognitive-enhancing effects of hydrolysate of polygalasaponin (HPS) on senescence accelerate mouse P8 (SAMP8) mice, an effective Alzheimer’s disease (AD) model, and to research the relevant mechanisms. Methods: The cognitive-enhancing effects of HPS on SAMP8 mice were assessed using Morris water maze (MWM) and step-through passive avoidance tests. Then N-methyl-D-aspartate (NMDA) receptor subunit expression for both the cortex and hippocampus of mice was observed using Western blotting. Results: HPS (25 and 50 mg/kg) improved the escape rate and decreased the escape latency and time spent in the target quadrant for the SAMP8 mice in the MWM after oral administration of HPS for 10 d. Moreover, it decreased error times in the passive avoidance tests. Western blotting showed that HPS was able to reverse the levels of NMDAR1 and NMDAR2B expression in the cortex or hippocampus of model mice. Conclusions: The present study suggested that HPS can improve cognitive deficits in SAMP8 mice, and this mechanism might be associated with NMDA receptor (NMDAR)-related pathways. PMID:27381727

[Influence of stimulation and blockade of α4β2 nicotinic acetylcholine receptors on learning of female rats in basic phases of ovary cycle].

PubMed

Fedotova, Iu O

2014-03-01

The present work was devoted to the comparative analysis of α4β2 nicotinic acetylcholine receptors (nAChRs) in learning/memory processes during ovary cycle in the adult female rats. RJR-2403 (1.0 mg/kg, i. p.), α4β2 nAChRs agonist and mecamylamine (1.0 mg/kg, i. p.), α4β2 nAChRs antagonist were injected chronically during 14 days. The processes of learning/memory were assessed in different models of learning: passive avoidance performance and Morris water maze. Chronic RJR-2403 administration to females improved the passive avoidance performance in proestrous and estrous as compared to the control animals. Also, RJR-2403 restored spatial learning of rats during proestrous phases in Morris water maze, and stimulated the dynamics of spatial learning during estrous phases. On the contrary, the chronic mecamylamine administration impaired non-spatial, and especially, spatial learning in females during key phases of ovary cycle. The results of the study suggest positive effect of α4β2 nAChRs stimulation in learning/memory processes during ovary cycle in the adult female rats.

The effect of sleep deprivation on leadership behaviour in military officers: an experimental study.

PubMed

Olsen, Olav Kjellevold; Pallesen, Ståle; Torsheim, Torbjørn; Espevik, Roar

2016-12-01

While several studies show that leaders frequently lack sleep, little is known about how this influences leadership behaviour. The present study encompasses an experiment that investigated how three main types of leadership behaviour: transformational (four sub-facets); transactional (two sub-facets); and passive-avoidant (two sub-facets) leadership differed across a rested and a long-term, partially sleep-deprived condition. A total of 16 military naval officers participated. In both conditions, the leaders managed a team of three subordinates in a navy navigation simulator, instructed to complete a specific mission (A or B). Both sleep state (rested or sleep deprived) and mission were counterbalanced. Leadership behaviour was video recorded and subsequently rated on the three leadership behaviours. Overall, the scores on transformational leadership (and on two of four sub-facets) and transactional leadership (on both sub-facets) decreased from the rested to sleep-deprived condition, whereas scores on passive-avoidant leadership overall (and on both sub-facets) increased from the rested to sleep-deprived condition. This study underscores the importance of including sleep as a potentially important determinant when assessing leadership effectiveness. © 2016 European Sleep Research Society.

Naringenin improves learning and memory in an Alzheimer's disease rat model: Insights into the underlying mechanisms.

PubMed

Ghofrani, Saeed; Joghataei, Mohammad-Taghi; Mohseni, Simin; Baluchnejadmojarad, Tourandokht; Bagheri, Maryam; Khamse, Safoura; Roghani, Mehrdad

2015-10-05

Alzheimer's disease (AD) is one of the prevalent neurological disorders of the central nervous system hallmarked by increased beta-amyloid (Aβ) deposition and ensuing learning and memory deficit. In the present study, the beneficial effect of naringenin on improvement of learning and memory was evaluated in an Alzheimer's disease rat model. The Aβ-injected rats showed a lower alternation score in Y-maze task, impairment of retention and recall capability in passive avoidance test, and lower correct choices and higher errors in radial arm maze (RAM) task as compared to sham group in addition to enhanced oxidative stress and apoptosis. Naringenin, but not a combination of naringenin and fulvestrant (an estrogenic receptor antagonist) significantly improved the performance of Aβ-injected rats in passive avoidance and RAM tasks. Naringenin pretreatment of Aβ-injected rats also lowered hippocampal malondialdehyde (MDA) with no significant effect on nitrite and superoxide dismutase (SOD) activity in addition to lowering apoptosis. These results suggest naringenin pretreatment attenuates Aβ-induced impairment of learning and memory through mitigation of lipid peroxidation and apoptosis and its beneficial effect is somewhat mediated via estrogenic pathway. Copyright © 2015 Elsevier B.V. All rights reserved.

Passivity-based control with collision avoidance for a hub-beam spacecraft

NASA Astrophysics Data System (ADS)

Wen, Hao; Chen, Ti; Jin, Dongping; Hu, Haiyan

2017-01-01

For the application of robotically assembling large space structures, a feedback control law is synthesized for transitional and rotational maneuvers of a 'tug' spacecraft in order to transport a flexible element to a desired position without colliding with other space bodies. The flexible element is treated as a long beam clamped to the 'tug' spacecraft modelled as a rigid hub. First, the physical property of passivity of Euler-Lagrange system is exploited to design the position and attitude controllers by taking a simpler obstacle-free control problem into account. To reduce sensing and actuating requirements, the vibration modes of the beam appendage are supposed to be not directly measured and actuated on. Besides, the requirements of measuring velocities are removed with the aid of a dynamic extension technique. Second, the bounding boxes in the form of super-quadric surfaces are exploited to enclose the maximal extents of the obstacles and the hub-beam spacecraft. The collision avoidance between bounding boxes is achieved by applying additional repulsive force and torque to the spacecraft based on the method of artificial potential field. Finally, the effectiveness of proposed control scheme is numerically demonstrated via case studies.

Curcumin exerts neuroprotective effects against homocysteine intracerebroventricular injection-induced cognitive impairment and oxidative stress in rat brain.

PubMed

Ataie, Amin; Sabetkasaei, Masoumeh; Haghparast, Abbas; Moghaddam, Akbar Hajizadeh; Ataee, Ramin; Moghaddam, Shiva Nasiraei

2010-08-01

Aging is the major risk factor for neurodegenerative diseases and oxidative stress and is involved in their pathophysiology. Oxidative stress can induce neuronal damage and modulate intracellular signaling, ultimately leading to neuronal death by apoptosis or necrosis. In this study we investigated the neuroprotective properties of the natural polyphenolic antioxidant compound, curcumin, against homocysteine (Hcy) neurotoxicity. Curcumin (5, 15, or 45 mg/kg) was injected intraperitoneally once daily for a period of 10 days beginning 5 days prior to Hcy (0.2 micromol/microl) intracerebroventricular injection in rats. Biochemical and behavioral studies, including passive avoidance learning and locomotor activity tests, were evaluated 24 hours after the last injection of curcumin or vehicle. Results indicated that Hcy induces lipid peroxidation and increases malondialdehyde (MDA) and superoxide anion (SOA) levels in whole rat brain. In addition, Hcy impaired memory retention in the passive avoidance learning test. However, curcumin treatment significantly decreased MDA and SOA levels and improved learning and memory in rats. These results suggest that Hcy may induce lipid peroxidation in rat brain and that polyphenol treatment (curcumin) improves learning and memory deficits by protecting the nervous system against oxidative stress.

Brain-derived neurotrophic factor transgenic mice exhibit passive avoidance deficits, increased seizure severity and in vitro hyperexcitability in the hippocampus and entorhinal cortex.

PubMed

Croll, S D; Suri, C; Compton, D L; Simmons, M V; Yancopoulos, G D; Lindsay, R M; Wiegand, S J; Rudge, J S; Scharfman, H E

1999-01-01

Transgenic mice overexpressing brain-derived neurotrophic factor from the beta-actin promoter were tested for behavioral, gross anatomical and physiological abnormalities. Brain-derived neurotrophic factor messenger RNA overexpression was widespread throughout brain. Overexpression declined with age, such that levels of overexpression decreased sharply by nine months. Brain-derived neurotrophic factor transgenic mice had no gross deformities or behavioral abnormalities. However, they showed a significant passive avoidance deficit. This deficit was dependent on continued overexpression, and resolved with age as brain-derived neurotrophic factor transcripts decreased. In addition, the brain-derived neurotrophic factor transgenic mice showed increased seizure severity in response to kainic acid. Hippocampal slices from brain-derived neurotrophic factor transgenic mice showed hyperexcitability in area CA3 and entorhinal cortex, but not in dentate gyrus. Finally, area CA1 long-term potentiation was disrupted, indicating abnormal plasticity. Our data suggest that overexpression of brain-derived neurotrophic factor in the brain can interfere with normal brain function by causing learning impairments and increased excitability. The results also support the hypothesis that excess brain-derived neurotrophic factor could be pro-convulsant in the limbic system.

Effects of repeated administration of (-)-nicotine on AF64A-induced learning and memory impairment in rats.

PubMed

Hiramatsu, M; Yamatsu, T; Kameyama, T; Nabeshima, T

2002-03-01

It has been reported that pretreatment with (-)-nicotine prevents glutamate- and amyloid beta protein (Abeta)-induced cytotoxicity in vitro. However, few studies on the neuroprotective effects of (-)-nicotine in vivo have been reported. We examined whether repeated administration of (-)-nicotine exhibits neuroprotective effects in AF64A-treated rats. (-)-Nicotine (0.1 and 0.2 mg/kg, s.c.) was administered once a day for 28 days. On day 14, AF64A (2.5 nmol/side) was injected bilaterally into the hippocampus. Intrahippocampal injection of AF64A showed severe impairment of learning and memory in rats in the water maze and passive avoidance tests. Repeated administration of (-)-nicotine (0.1 and 0.2 mg/kg, s.c.) did not reverse the impairment of memory induced by AF64A in the water maze test. Interestingly, the (-)-nicotine (0.1 and 0.2 mg/kg, s.c.)-treated group showed weak impairment of learning and memory after AF64A treatment compared to the (AF64A + saline)-treated group in the passive avoidance test. These results suggested that (-)-nicotine may have neuroprotective effects against the neurotoxicity induced by AF64A.

[Study on corrosion resistance of three non-noble porcelain alloys].

PubMed

Wu, Zhikai; Xu, Sheng; Li, Wei; Teng, Jin; Li, Ning

2011-10-01

To study the electrochemical corrosion behavior of Co-Cr, Ni-Cr and Ni-Cr-Be based porcelain alloys in NaCl solution. Five samples of each alloy were made respectively, electric polarization curve of each alloy was obtained using potentiodynamic polarization technique. Self-corrosion potential (E(corr)), self-corrosion current density (I(corr), passive region and transpassivation potential were tested. Microstructure and constituent was examined using scanning electron microscopy and energy dispersive spectroscopy. Co-Cr alloy possessed the most desirable corrosion resistance because of its integrated, homogeneous and compact passive film. The poor compactness of Ni-Cr alloy's passive film decreased its corrosion resistance. Ni-Cr-Be alloy exhibited the worst corrosion resistance due to the Cr and Mo depleted Ni-Be eutectic phases in the alloy. Taking biological security into consideration, it is necessary to avoid the application of porcelain alloys with Be element. Co-Cr alloy with better biocompatibility possesses much broader prospect in the field of dental restoration.

Support for the Naval Research Laboratory Environmental Passive Microwave Remote Sensing Program.

DTIC Science & Technology

1983-04-29

L. H. Gesell te _ C= Project Manager ’ . . , . ".."........... . ., . q J ABSTRACT This document summarizes the data acquisition, reduc- tion, and...film camera , and other environmental sensors. CSC gradually assumed the bulk of the responsibility for opera- ting this equipment. This included running...radiometers, and setting up and operating the strip-film camera and other en- vironmental sensors. Also of significant importance to the missions was

A portable respiratory rate estimation system with a passive single-lead electrocardiogram acquisition module.

PubMed

Nayan, Nazrul Anuar; Risman, Nur Sabrina; Jaafar, Rosmina

2016-07-27

Among vital signs of acutely ill hospital patients, respiratory rate (RR) is a highly accurate predictor of health deterioration. This study proposes a system that consists of a passive and non-invasive single-lead electrocardiogram (ECG) acquisition module and an ECG-derived respiratory (EDR) algorithm in the working prototype of a mobile application. Before estimating RR that produces the EDR rate, ECG signals were evaluated based on the signal quality index (SQI). The SQI algorithm was validated quantitatively using the PhysioNet/Computing in Cardiology Challenge 2011 training data set. The RR extraction algorithm was validated by adopting 40 MIT PhysioNet Multiparameter Intelligent Monitoring in Intensive Care II data set. The estimated RR showed a mean absolute error (MAE) of 1.4 compared with the ``gold standard'' RR. The proposed system was used to record 20 ECGs of healthy subjects and obtained the estimated RR with MAE of 0.7 bpm. Results indicate that the proposed hardware and algorithm could replace the manual counting method, uncomfortable nasal airflow sensor, chest band, and impedance pneumotachography often used in hospitals. The system also takes advantage of the prevalence of smartphone usage and increase the monitoring frequency of the current ECG of patients with critical illnesses.

Investigation of remote sensing techniques of measuring soil moisture

NASA Technical Reports Server (NTRS)

Newton, R. W. (Principal Investigator); Blanchard, A. J.; Nieber, J. L.; Lascano, R.; Tsang, L.; Vanbavel, C. H. M.

1981-01-01

Major activities described include development and evaluation of theoretical models that describe both active and passive microwave sensing of soil moisture, the evaluation of these models for their applicability, the execution of a controlled field experiment during which passive microwave measurements were acquired to validate these models, and evaluation of previously acquired aircraft microwave measurements. The development of a root zone soil water and soil temperature profile model and the calibration and evaluation of gamma ray attenuation probes for measuring soil moisture profiles are considered. The analysis of spatial variability of soil information as related to remote sensing is discussed as well as the implementation of an instrumented field site for acquisition of soil moisture and meteorologic information for use in validating the soil water profile and soil temperature profile models.

ESAC RFI Survey in the SMOS 1400-1427MHz Passive Band

NASA Astrophysics Data System (ADS)

Castillo-Fraile, Manuel; Uranga, Ekhi

2016-08-01

The SMOS (Soil Moisture and Ocean Salinity) satellite was launched on 2 November 2009, and it is the ESA second Earth Explorer Opportunity mission. After 6 years of successful Operations, the status of the SMOS mission is excellent, and it is providing very reliable acquisition, nominal and NRT data processing, archiving, and dissemination services of Level 1 and Level 2 processed data around the entire Planet. However, SMOS observations are significantly affected by RF interferences in several World areas. In this context, a new RFI detection and monitoring tool has been implemented at ESAC to provide to the national radiofrequency authorities with a proper detection and localization method of the illegal ground emitters in order to ensure the protection of the SMOS 1400- 1427MHz Passive Band for scientific applications.

Gyro-effect stabilizes unstable permanent maglev centrifugal pump.

PubMed

Qian, Kun-Xi

2007-03-01

According to Earnshaw's Theorem (1839), the passive maglev cannot achieve stable equilibrium and thus an extra coil is needed to make the rotor electrically levitated in a heart pump. The author had developed a permanent maglev centrifugal pump utilizing only passive magnetic bearings, to keep the advantages but to avoid the disadvantages of the electric maglev pumps. The equilibrium stability was achieved by use of so-called "gyro-effect": a rotating body with certain high speed can maintain its rotation stably. This pump consisted of a rotor (driven magnets and an impeller), and a stator with motor coil and pump housing. Two passive magnetic bearings between rotor and stator were devised to counteract the attractive force between the motor coil iron core and the rotor driven magnets. Bench testing with saline demonstrated a levitated rotor under preconditions of higher than 3,250 rpm rotation and more than 1 l/min pumping flow. Rotor levitation was demonstrated by 4 Hall sensors on the stator, with evidence of reduced maximal eccentric distance from 0.15 mm to 0.07 mm. The maximal rotor vibration amplitude was 0.06 mm in a gap of 0.15 mm between rotor and stator. It concluded that Gyro-effect can help passive maglev bearings to achieve stabilization of permanent maglev pump; and that high flow rate indicates good hydraulic property of the pump, which helps also the stability of passive maglev pump.

Autonomously acquiring declarative and procedural knowledge for ICAT systems

NASA Technical Reports Server (NTRS)

Kovarik, Vincent J., Jr.

1993-01-01

The construction of Intelligent Computer Aided Training (ICAT) systems is critically dependent on the ability to define and encode knowledge. This knowledge engineering effort can be broadly divided into two categories: domain knowledge and expert or task knowledge. Domain knowledge refers to the physical environment or system with which the expert interacts. Expert knowledge consists of the set of procedures and heuristics employed by the expert in performing their task. Both these areas are a significant bottleneck in the acquisition of knowledge for ICAT systems. This paper presents a research project in the area of autonomous knowledge acquisition using a passive observation concept. The system observes an expert and then generalizes the observations into production rules representing the domain expert's knowledge.

Semiconductor with protective surface coating and method of manufacture thereof. [Patent application

DOEpatents

Hansen, W.L.; Haller, E.E.

1980-09-19

Passivation of predominantly crystalline semiconductor devices is provided for by a surface coating of sputtered hydrogenated amorphous semiconductor material. Passivation of a radiation detector germanium diode, for example, is realized by sputtering a coating of amorphous germanium onto the etched and quenched diode surface in a low pressure atmosphere of hydrogen and argon. Unlike prior germanium diode semiconductor devices, which must be maintained in vacuum at cryogenic temperatures to avoid deterioration, a diode processed in the described manner may be stored in air at room temperature or otherwise exposed to a variety of environmental conditions. The coating compensates for pre-existing undesirable surface states as well as protecting the semiconductor device against future impregnation with impurities.

Dynamical thermal effects in InGaAsP microtubes at telecom wavelengths.

PubMed

Tian, Zhaobing; Bianucci, Pablo; Roche, Philip J R; Dastjerdi, M Hadi Tavakoli; Mi, Zetian; Poole, Philip J; Kirk, Andrew G; Plant, David V

2012-07-01

We report on the observation of a dynamical thermal effect in InGaAsP microtubes at telecom wavelengths. The microtubes are fabricated by releasing a strained semiconductor bilayer and are picked up by abruptly tapered optical fibers for subsequent coupling with adiabatically tapered optical fibers. As a result of absorption by InAs quantum dots embedded in the tube structure, these microtubes show dynamical thermal effects at wavelengths around 1525 nm and 1578 nm, while they are passive at longer wavelengths near 1634 nm. The photon absorption induced thermal effect is visualized by generating a pair of microbottles. The dynamical thermal effect can be avoided or exploited for passive or active applications by utilizing appropriate resonance wavelengths.

48 CFR 909.504 - Contracting officer's responsibility.

Code of Federal Regulations, 2010 CFR

2010-10-01

... such firms for interests relating to a potential organizational conflict of interest in the performance... ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Organizational and Consultant Conflicts of Interest 909.504... potential organizational conflict of interest and identify any actions that may be taken to avoid...

48 CFR 909.504 - Contracting officer's responsibility.

Code of Federal Regulations, 2011 CFR

2011-10-01

... such firms for interests relating to a potential organizational conflict of interest in the performance... ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Organizational and Consultant Conflicts of Interest 909.504... potential organizational conflict of interest and identify any actions that may be taken to avoid...

What are the Effects of Protest Fear?

DTIC Science & Technology

2014-06-01

Program AT&L Acquisition, Technology, and Logistics BPA blanket purchase agreement CONUS continental United States COR...they have awarded a task/delivery order against an IDIQ contract (or Blanket Purchase Agreement [ BPA ]) in order to avoid a bid protest. The data shows

HIV vaccine research and discovery in the nonhuman primates model: a unified theory in acquisition prevention and control of SIV infection.

PubMed

Lynch, Rebecca M; Yamamoto, Takuya; McDermott, Adrian B

2013-07-01

Here we highlight the latest advances in HIV vaccine concepts that will expand our knowledge on how to elicit effective acquisition-prevention and/or control of simian immunodeficiency virus (SIV) replication in the nonhuman primate (NHP) model. In the context of the promising analyses from the RV144 Thai Trial and the effective control of SIV replication exerted by rhCMV-(SIV) elicited EM CD8 T cells, the HIV field has recently shifted toward vaccine concepts that combine protection from acquisition with effective control of SIV replication. Current studies in the NHP model have demonstrated the efficacy of HIV-neutralizing antibodies via passive transfer, the potential importance of the CD4 Tfh subset, the ability to effectively model the RV144 vaccine trial and the capacity of an Ad26 prime and modified vaccinia Ankara virus boost to elicit Env-specific antibody and cellular responses that both limit acquisition and control heterologous SIVmac251 challenge. The latest work in the NHP model suggests that the next generation HIV-1 vaccines should aim to provoke a comprehensive adaptive immune response for both prevention of SIV acquisition as well as control of replication in breakthrough infection.

Detrimental Effects of Helium Ion Irradiation on Cognitive Performance and Cortical Levels of MAP-2 in B6D2F1 Mice.

PubMed

Raber, Jacob; Torres, Eileen Ruth S; Akinyeke, Tunde; Lee, Joanne; Weber Boutros, Sydney J; Turker, Mitchell S; Kronenberg, Amy

2018-04-20

The space radiation environment includes helium (⁴He) ions that may impact brain function. As little is known about the effects of exposures to ⁴He ions on the brain, we assessed the behavioral and cognitive performance of C57BL/6J × DBA2/J F1 (B6D2F1) mice three months following irradiation with ⁴He ions (250 MeV/n; linear energy transfer (LET) = 1.6 keV/μm; 0, 21, 42 or 168 cGy). Sham-irradiated mice and mice irradiated with 21 or 168 cGy showed novel object recognition, but mice irradiated with 42 cGy did not. In the passive avoidance test, mice received a slight foot shock in a dark compartment, and latency to re-enter that compartment was assessed 24 h later. Sham-irradiated mice and mice irradiated with 21 or 42 cGy showed a higher latency on Day 2 than Day 1, but the latency to enter the dark compartment in mice irradiated with 168 cGy was comparable on both days. ⁴He ion irradiation, at 42 and 168 cGy, reduced the levels of the dendritic marker microtubule-associated protein-2 (MAP-2) in the cortex. There was an effect of radiation on apolipoprotein E (apoE) levels in the hippocampus and cortex, with higher apoE levels in mice irradiated at 42 cGy than 168 cGy and a trend towards higher apoE levels in mice irradiated at 21 than 168 cGy. In addition, in the hippocampus, there was a trend towards a negative correlation between MAP-2 and apoE levels. While reduced levels of MAP-2 in the cortex might have contributed to the altered performance in the passive avoidance test, it does not seem sufficient to do so. The higher hippocampal and cortical apoE levels in mice irradiated at 42 than 168 cGy might have served as a compensatory protective response preserving their passive avoidance memory. Thus, there were no alterations in behavioral performance in the open filed or depressive-like behavior in the forced swim test, while cognitive impairments were seen in the object recognition and passive avoidance tests, but not in the contextual or cued fear conditioning tests. Taken together, the results indicate that some aspects of cognitive performance are altered in male mice exposed to ⁴He ions, but that the response is task-dependent. Furthermore, the sensitive doses can vary within each task in a non-linear fashion. This highlights the importance of assessing the cognitive and behavioral effects of charged particle exposure with a variety of assays and at multiple doses, given the possibility that lower doses may be more damaging due to the absence of induced compensatory mechanisms at higher doses.

Development of remote data acquisition system based on OPC for brake test bench

NASA Astrophysics Data System (ADS)

Wang, Yiwei; Wu, Mengling; Tian, Chun; Ma, Tianhe

2017-08-01

The 1:1 train brake system test bench can be used to carry out brake-related adhesion-slid control, stability test, noise test and dynamic test. To collect data of the test bench, a data acquisition method is needed. In this paper, the remote data acquisition system of test bench is built by LabVIEW based on OPC technology. Unlike the traditional hardwire way connecting PLC acquisition module with sensors, the novel method is used to collect data and share them through the internal LAN built by Ethernet switches, which avoids the complex wiring interference in an easy, efficient and flexible way. The system has been successfully applied to the data acquisition activities of the comprehensive brake system test bench of CRRC Nanjing Puzhen Haitai Brake Equipment Co., Ltd., and the relationship test between the adhesion coefficient and the slip-ratio is realized. The speed signal, torque signal and brake disc temperature can be collected and displayed. The results show that the system is reliable, convenient, and efficient, and can meet the requirements of data acquisition.

Discrimination and avoidance learning in adult mice following developmental exposure to diisopropylfluorophosphate.

PubMed

Levi, Yifat; Kofman, Ora; Schwebel, Margalit; Shaldubina, Alona

2008-02-01

Exposure to acetylcholinesterase inhibitors during development was shown in the past to induce sex-dependent changes in locomotion and specific cognitive and emotional tests in rodents. Adult mice that had been treated with 0.5 mg/kg diisopropylfluorphosphate (DFP), on post-natal days 14-20 were tested on active avoidance and a set-shifting task. DFP pre-treatment did not affect the active avoidance task, but impaired performance on the extra-dimensional shift task. DFP-treated females showed more general deficits in the acquisition of simple discrimination, intra-dimensional shift, extra-dimensional shift and reversal learning. These data suggest that pre-weanling exposure to cholinesterase inhibitors may have long-term consequences on attentional capabilities.

Behavioral and experiential avoidance in patients with hoarding disorder.

PubMed

Ayers, Catherine R; Castriotta, Natalie; Dozier, Mary E; Espejo, Emmanuel P; Porter, Ben

2014-09-01

This study examined the relationship between experiential and behavioral avoidance and hoarding symptom severity, controlling for anxiety and depression symptoms, in 66 adult individuals (M age = 61.41; SD = 9.03) with HD. Hierarchical regression was used to test the associations between hoarding severity, as defined by the Savings Inventory-Revised (SI-R) total and its three subscales, and avoidance, as defined by the Acceptance and Action Questionnaire II (AAQ-II) and two scales from the Brief COPE (Self-Distraction and Behavioral Disengagement) when controlling for anxiety and depression symptoms. Experiential avoidance (AAQ-II) and behavioral avoidance (Brief COPE subscales Self-Distraction and Behavioral Disengagement) uniquely accounted for aspects of hoarding severity (SI-R) in regression models. Behavioral avoidance contributed significant additional variance to the SI-R Clutter subscale, whereas experiential avoidance was uniquely predictive of additional variance in the SI-R Difficulty Discarding and the SI-R Acquisition subscales. Future research should examine the effect of experiential avoidance on hoarding behaviors experimentally. Given that the AAQ-II and Self-Distraction and Behavioral Disengagement subscales were not correlated, these findings suggest that experiential and behavioral avoidance are two distinct processes contributing to the severity of specific HD. Results support the utility of avoidance in the cognitive-behavioral model for HD. Copyright © 2014 Elsevier Ltd. All rights reserved.

Variable learning performance: the levels of behaviour organization.

PubMed

Csányi, V; Altbäcker, V

1990-01-01

Our experiments were focused on some special aspects of learning in the paradise fish. Passive avoidance conditioning method was used with different success depending on the complexity of the learning tasks. In the case of simple behavioural elements various "constrains" on avoidance learning were found. In a small, covered place the fish were ready to perform freezing reaction and mild punishment increased the frequency and duration of the freezing bouts very substantially. However, it was very difficult to enhance the frequency of freezing by punishment in a tank with transparent walls, where the main response to punishment was escape. The most easily learned tasks were the complex ones which had several different solutions. The fish learned to avoid either side of an aquarium very easily because they could use various behavioural elements to solve the problem. These findings could be interpreted within the framework of different organizational levels of behaviour.

Inhibition of long-term memory formation by anti-ependymin antisera after active shock-avoidance learning in goldfish.

PubMed

Piront, M L; Schmidt, R

1988-02-23

Ependymins are acidic glycoprotein constituents of goldfish brain cytoplasm and extracellular fluid which are known to participate in biochemical reactions of long-term memory formation. In earlier experiments, anti-ependymin antisera were found to cause amnesia when injected into goldfish brain ventricles after the acquisition of a vestibulomotoric training task. To investigate whether they also inhibit memory consolidation after other learning events the anti-ependymin antisera were injected after an active shock-avoidance learning paradigm, as follows: goldfish were trained in a shuttle-box to cross a barrier in order to avoid electric shocks (unconditioned stimulus) applied shortly after a light signal (conditioned stimulus). Anti-ependymin antisera blocked retention of the learned avoidance when injected 0.5, 4.5 or 24 h after acquisition of the new behavior. They had no effect, however, when injected 72 h after learning. Apparently, long-term memory was already consolidated at this point. Antisera injected 0.5 or 72 h prior to training, also did not influence learning or memory. Thirteen percent of the goldfish fled the light stimulus spontaneously. These fish therefore did not experience the unconditioned stimulus and thus were unable to learn the task. When they were treated with the anti-ependymin antisera and tested 3 days later, the spontaneous escape reaction was not affected (active control group). The ability of anti-ependymin antisera to inhibit memory consolidation and their efficacy after administration at specific time intervals are very similar for the active shock-avoidance learning and for the vestibulomotoric training. We conclude that ependymins are not task-specific, but serve a general function in biochemical reactions essential for long-term memory formation.

Airborne active and passive L-band measurements using PALS instrument in SMAPVEX12 soil moisture field campaign

NASA Astrophysics Data System (ADS)

Colliander, Andreas; Yueh, Simon; Chazanoff, Seth; Dinardo, Steven; O'Dwyer, Ian; Jackson, Thomas; McNairn, Heather; Bullock, Paul; Wiseman, Grant; Berg, Aaron; Magagi, Ramata; Njoku, Eni

2012-10-01

NASA's (National Aeronautics and Space Administration) Soil Moisture Active Passive (SMAP) Mission is scheduled for launch in late 2014. The objective of the mission is global mapping of soil moisture and freeze/thaw state. Merging of active and passive L-band observations of the mission will enable unprecedented combination of accuracy, resolution, coverage and revisit-time for soil moisture and freeze/thaw state retrieval. For pre-launch algorithm development and validation the SMAP project and NASA coordinated a field campaign named as SMAPVEX12 (Soil Moisture Active Passive Validation Experiment 2012) together with Agriculture and Agri-Food Canada, and other Canadian and US institutions in the vicinity of Winnipeg, Canada in June-July, 2012. The main objective of SMAPVEX12 was acquisition of a data record that features long time-series with varying soil moisture and vegetation conditions over an aerial domain of multiple parallel flight lines. The coincident active and passive L-band data was acquired with the PALS (Passive Active L-band System) instrument. The measurements were conducted over the experiment domain every 2-3 days on average, over a period of 43 days. The preliminary calibration of the brightness temperatures obtained in the campaign has been performed. Daily lake calibrations were used to adjust the radiometer calibration parameters, and the obtained measurements were compared against the raw in situ soil moisture measurements. The evaluation shows that this preliminary calibration of the data produces already a consistent brightness temperature record over the campaign duration, and only secondary adjustments and cleaning of the data is need before the data can be applied to the development and validation of SMAP algorithms.

An airborne sensor for the avoidance of clear air turbulence

NASA Technical Reports Server (NTRS)

Gary, B. L.

1981-01-01

This paper describes an airborne microwave radiometer that may be able to provide altitude guidance away from layers containing clear air turbulence, CAT. The sensor may also be able to predict upper limits for the severity of upcoming CAT. The 55 GHz radiometer is passive, not radar, and it measures the temperature of oxygen molecules in the viewing direction (averaged along a several-kilometer path). A small computer directs the viewing direction through elevation angle scans, and converts observed quantities to an 'altitude temperature profile'. The principle for CAT avoidance is that CAT is found statistically more often within inversion layers and at the tropopause, both of which are easily located from sensor-generated altitude temperature profiles.

Age differences in everyday problem-solving effectiveness: older adults select more effective strategies for interpersonal problems.

PubMed

Blanchard-Fields, Fredda; Mienaltowski, Andrew; Seay, Renee Baldi

2007-01-01

Using the Everyday Problem Solving Inventory of Cornelius and Caspi, we examined differences in problem-solving strategy endorsement and effectiveness in two domains of everyday functioning (instrumental or interpersonal, and a mixture of the two domains) and for four strategies (avoidance-denial, passive dependence, planful problem solving, and cognitive analysis). Consistent with past research, our research showed that older adults were more problem focused than young adults in their approach to solving instrumental problems, whereas older adults selected more avoidant-denial strategies than young adults when solving interpersonal problems. Overall, older adults were also more effective than young adults when solving everyday problems, in particular for interpersonal problems.

Original nootropic drug noopept prevents memory deficit in rats with muscarinic and nicotinic receptor blockade.

PubMed

Radionova, K S; Belnik, A P; Ostrovskaya, R U

2008-07-01

Antiamnesic activity of Noopept was studied on the original three-way model of conditioned passive avoidance response, which allows studying spatial component of memory. Cholinoceptor antagonists of both types (scopolamine and mecamylamine) decreased entry latency and reduced the probability for selection of the safe compartment. Noopept abolished the antiamnesic effect of cholinoceptor antagonists and improved spatial preference.

Euthanasia: a summary of the law in England and Wales.

PubMed

Simillis, Constantinos

2008-07-01

When medical treatment becomes futile, or the patient's suffering is intractable, doctors face the agonising dilemma of whether to proceed with euthanasia. It is important for a doctor to be familiar with the law surrounding euthanasia, in order to avoid prosecution. This paper explores the law in England and Wales regarding the different categories of euthanasia: voluntary euthanasia, nonvoluntary euthanasia, passive euthanasia, and active euthanasia.

Effects of Green Tea Extract on Learning, Memory, Behavior and Acetylcholinesterase Activity in Young and Old Male Rats

ERIC Educational Resources Information Center

Kaur, Tranum; Pathak, C. M.; Pandhi, P.; Khanduja, K. L.

2008-01-01

Objective: To study the effects of green tea extract administration on age-related cognition in young and old male Wistar rats. Methods: Young and old rats were orally administered 0.5% green tea extract for a period of eight weeks and were evaluated by passive avoidance, elevated maze plus paradigm and changes in acetylcholinesterase activity.…

Age Moderates the Effect of Acute Dopamine Depletion on Passive Avoidance Learning

PubMed Central

Kelm, Mary Katherine; Boettiger, Charlotte Ann

2015-01-01

Despite extensive links between reinforcement-based learning and dopamine (DA), studies to date have not found consistent effects of acute DA reduction on reinforcement learning in both men and women. Here, we tested the effects of reducing DA on reward- and punishment-based learning using the deterministic passive avoidance learning (PAL) task We tested 16 (5 female) adults (ages 22–40) in a randomized, cross-over design to determine whether reducing global DA by administering an amino acid beverage deficient in the DA precursors, phenylalanine and tyrosine (P/T[−]), would affect performance on the PAL task. We found that P/T[−] beverage effects on PAL performance were modulated by age. In particular, we found that P/T depletion significantly improved learning from punishment with increasing participant age. Participants committed 1.49 fewer passive avoidance errors per additional year of age (95% CI, −0.71 – −2.27, r=−0.74, p=0.001). Moreover, in this small sample, P/T depletion improved learning from punishment in adults (ages 26–40) while it impaired learning from punishment in emerging adults (ages 22–25). We observed similar, but non-significant trends in learning from reward. While there was no overall effect of P/T-depletion on reaction time (RT), there was a relationship between the effect of P/T depletion on PAL performance and RT; those who responded more slowly on the P/T[−] beverage also made more errors on the P/T[−] beverage. When P/T-depletion slowed RT after a correct response, there was a worsening of PAL task performance; there was no similar relationship for the RT after an incorrect response and PAL task performance. Moreover, among emerging adults, changes in mood on the P/T[−] beverage negatively correlated with learning from reward on the P/T[−] beverage. Together, we found that both reward- and punishment-based learning are sensitive to central catecholamine levels, and that these effects of acute DA reduction vary with age. PMID:25636601

The effect of chronic stimulation of serotonin receptor type 7 on recognition, passive avoidance memory, hippocampal long-term potentiation, and neuronal apoptosis in the amyloid β protein treated rat.

PubMed

Shahidi, Siamak; Asl, Sara Soleimani; Komaki, Alireza; Hashemi-Firouzi, Nasrin

2018-05-01

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by memory impairment, neuronal death, and synaptic loss in the hippocampus. Long-term potentiation (LTP), a type of synaptic plasticity, occurs during learning and memory. Serotonin receptor type 7 (5-HTR7) activation is suggested as a possible therapeutic target for AD. The aim of the present study was to examine the effects of chronic treatment with the 5-HTR7 agonist, AS19, on cognitive function, memory, hippocampal plasticity, amyloid beta (Aβ) plaque accumulation, and apoptosis in an adult rat model of AD. AD was induced in rats using Aβ (single 1 μg/μL intracerebroventricular (icv) injection during surgery). The following experimental groups were included: control, sham-operated, Aβ + saline (1 μL icv for 30 days), and Aβ + AS19 (1 μg/μL icv for 30 days) groups. The animals were tested for cognition and memory performance using the novel object recognition and passive avoidance tests, respectively. Next, anesthetized rats were placed in a stereotaxic apparatus for electrode implantation, and field potentials were recorded in the hippocampal dentate gyrus. Lastly, brains were removed and Aβ plaques and neuronal apoptosis were evaluated using Congo red staining and TUNEL assay, respectively. Administration of AS19 in the Aβ rats increased the discrimination index of the novel object recognition test. Furthermore, AS19 treatment decreased time spent in the dark compartment during the passive avoidance test. AS19 also enhanced both the population spike (PS) amplitude and the field excitatory postsynaptic potential (fEPSP) slope evoked potentials of the LTP components. Aβ plaques and neuronal apoptosis were decreased in the AS19-treated Aβ rats. These results indicate that chronic treatment with a 5-HTR7 agonist can prevent Aβ-related impairments in cognition and memory performance by alleviating Aβ plaque accumulation and neuronal apoptosis, hence improving neuronal plasticity. AS19 may be useful as a therapeutic agent for AD.

Evaluation of passive avoidance learning and spatial memory in rats exposed to low levels of lead during specific periods of early brain development.

PubMed

Rao Barkur, Rajashekar; Bairy, Laxminarayana K

2015-01-01

Widespread use of heavy metal lead (Pb) for various commercial purposes has resulted in the environmental contamination caused by this metal. The studies have shown a definite relationship between low level lead exposure during early brain development and deficit in children's cognitive functions. This study investigated the passive avoidance learning and spatial learning in male rat pups exposed to lead through their mothers during specific periods of early brain development. Experimental male rats were divided into 5 groups: i) the normal control group (NC) (N = 12) consisted of rat offspring born to mothers who were given normal drinking water throughout gestation and lactation, ii) the pre-gestation lead exposed group (PG) (N = 12) consisted of rat offspring, mothers of these rats had been exposed to 0.2% lead acetate in the drinking water for 1 month before conception, iii) the gestation lead exposed group (G) (N = 12) contained rat offspring born to mothers who had been exposed to 0.2% lead acetate in the drinking water throughout gestation, iv) the lactation lead exposed group (L) (N = 12) had rat offspring, mothers of these rats exposed to 0.2% lead acetate in the drinking water throughout lactation and v) the gestation and lactation lead exposed group (GL) (N = 12) contained rat offspring, mothers of these rats were exposed to 0.2% lead acetate throughout gestation and lactation. The study found deficit in passive avoidance learning in the G, L and GL groups of rats. Impairment in spatial learning was found in the PG, G, L and GL groups of rats. Interestingly, the study found that gestation period only and lactation period only lead exposure was sufficient to cause deficit in learning and memory in rats. The extent of memory impairment in the L group of rats was comparable with the GL group of rats. So it can be said that postnatal period of brain development is more sensitive to neurotoxicity compared to prenatal exposure. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Working Papers in Acquisition of Knowledge for Image Understanding Research,

DTIC Science & Technology

1976-12-15

Rmvt 112,7,P IM Y. K3p ’Of’ z4-" odK zw Mw; OW, ev 6 "ONO T;I 11; "VI lip, IA wo 44 jo . ... . ...... I I WORKING PAPERS IN ACQUISITION OF...paradigm than any other. They have collected protocolt on subjects verbally describing scenes, after examining them visually. The control variable they... collection of Elements of Control Flow (ECF). To avoid creation of either file, the user presses the return key without typing a name to the respective

Treating the merger as a taxable versus tax-free combination.

PubMed

Finkler, S A; Karlinsky, S S

1985-04-01

A key issue in any business combination is whether the transaction is to be a taxable acquisition or a tax-free reorganization. Neither structure's benefits clearly dominate. Taxable acquisitions result in greater inventory cost and depreciation tax benefits to the buyer and more tax to the seller. Tax-free reorganizations allow the seller to avoid current payment of at least some taxes but result in less favorable tax benefits to the buyer. Each merger must therefore be tailored to fit the specific needs and wishes of the parties involved.

How Much of Language Acquisition Does Operant Conditioning Explain?

PubMed

Sturdy, Christopher B; Nicoladis, Elena

2017-01-01

Since the 1950s, when Chomsky argued that Skinner's arguments could not explain syntactic acquisition, psychologists have generally avoided explicitly invoking operant or instrumental conditioning as a learning mechanism for language among human children. In this article, we argue that this is a mistake. We focus on research that has been done on language learning in human infants and toddlers in order to illustrate our points. Researchers have ended up inventing learning mechanisms that, in actual practice, not only resemble but also in fact are examples of operant conditioning (OC) by any other name they select. We argue that language acquisition researchers should proceed by first ruling out OC before invoking alternative learning mechanisms. While it is possible that OC cannot explain all of the language acquisition, simple learning mechanisms that work across species may have some explanatory power in children's language learning.

How Much of Language Acquisition Does Operant Conditioning Explain?

PubMed Central

Sturdy, Christopher B.; Nicoladis, Elena

2017-01-01

Since the 1950s, when Chomsky argued that Skinner’s arguments could not explain syntactic acquisition, psychologists have generally avoided explicitly invoking operant or instrumental conditioning as a learning mechanism for language among human children. In this article, we argue that this is a mistake. We focus on research that has been done on language learning in human infants and toddlers in order to illustrate our points. Researchers have ended up inventing learning mechanisms that, in actual practice, not only resemble but also in fact are examples of operant conditioning (OC) by any other name they select. We argue that language acquisition researchers should proceed by first ruling out OC before invoking alternative learning mechanisms. While it is possible that OC cannot explain all of the language acquisition, simple learning mechanisms that work across species may have some explanatory power in children’s language learning. PMID:29163295

Effects of heavy particle irradiation and diet on amphetamine- and lithium chloride-induced taste avoidance learning in rats

NASA Technical Reports Server (NTRS)

Rabin, Bernard M.; Shukitt-Hale, Barbara; Szprengiel, Aleksandra; Joseph, James A.

2002-01-01

Rats were maintained on diets containing either 2% blueberry or strawberry extract or a control diet for 8 weeks prior to being exposed to 1.5 Gy of 56Fe particles in the Alternating Gradient Synchrotron at Brookhaven National Laboratory. Three days following irradiation, the rats were tested for the effects of irradiation on the acquisition of an amphetamine- or lithium chloride-induced (LiCl) conditioned taste avoidance (CTA). The rats maintained on the control diet failed to show the acquisition of a CTA following injection of amphetamine. In contrast, the rats maintained on antioxidant diets (strawberry or blueberry extract) continued to show the development of an amphetamine-induced CTA following exposure to 56Fe particles. Neither irradiation nor diet had an effect on the acquisition of a LiCl-induced CTA. The results are interpreted as indicating that oxidative stress following exposure to 56Fe particles may be responsible for the disruption of the dopamine-mediated amphetamine-induced CTA in rats fed control diets; and that a reduction in oxidative stress produced by the antioxidant diets functions to reinstate the dopamine-mediated CTA. The failure of either irradiation or diet to influence LiCl-induced responding suggests that oxidative stress may not be involved in CTA learning following injection of LiCl.

NCAM deficiency in the mouse forebrain impairs innate and learned avoidance behaviours.

PubMed

Brandewiede, J; Stork, O; Schachner, M

2014-06-01

The neural cell adhesion molecule (NCAM) has been implicated in the development and plasticity of neural circuits and the control of hippocampus- and amygdala-dependent learning and behaviour. Previous studies in constitutive NCAM null mutants identified emotional behaviour deficits related to disturbances of hippocampal and amygdala functions. Here, we studied these behaviours in mice conditionally deficient in NCAM in the postmigratory forebrain neurons. We report deficits in both innate and learned avoidance behaviours, as observed in elevated plus maze and passive avoidance tasks. In contrast, general locomotor activity, trait anxiety or neophobia were unaffected by the mutation. Altered avoidance behaviour of the conditional NCAM mutants was associated with a deficit in serotonergic signalling, as indicated by their reduced responsiveness to (±)-8-hydroxy-2-(dipropylamino)-tetralin-induced hypothermia. Another serotonin-dependent behaviour, namely intermale aggression that is massively increased in constitutively NCAM-deficient mice, was not affected in the forebrain-specific mutants. Our data suggest that genetically or environmentally induced changes of NCAM expression in the late postnatal and mature forebrain determine avoidance behaviour and serotonin (5-HT)1A receptor signalling. © 2014 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Studies of learned helplessness in honey bees (Apis mellifera ligustica).

PubMed

Dinges, Christopher W; Varnon, Christopher A; Cota, Lisa D; Slykerman, Stephen; Abramson, Charles I

2017-04-01

The current study reports 2 experiments investigating learned helplessness in the honey bee (Apis mellifera ligustica). In Experiment 1, we used a traditional escape method but found the bees' activity levels too high to observe changes due to treatment conditions. The bees were not able to learn in this traditional escape procedure; thus, such procedures may be inappropriate to study learned helplessness in honey bees. In Experiment 2, we used an alternative punishment, or passive avoidance, method to investigate learned helplessness. Using a master and yoked design where bees were trained as either master or yoked and tested as either master or yoked, we found that prior training with unavoidable and inescapable shock in the yoked condition interfered with avoidance and escape behavior in the later master condition. Unlike control bees, learned helplessness bees failed to restrict their movement to the safe compartment following inescapable shock. Unlike learned helplessness studies in other animals, no decrease in general activity was observed. Furthermore, we did not observe a "freezing" response to inescapable aversive stimuli-a phenomenon, thus far, consistently observed in learned helplessness tests with other species. The bees, instead, continued to move back and forth between compartments despite punishment in the incorrect compartment. These findings suggest that, although traditional escape methods may not be suitable, honey bees display learned helplessness in passive avoidance procedures. Thus, regardless of behavioral differences from other species, honey bees can be a unique invertebrate model organism for the study of learned helplessness. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Developmental subchronic exposure to diphenylarsinic acid induced increased exploratory behavior, impaired learning behavior, and decreased cerebellar glutathione concentration in rats.

PubMed

Negishi, Takayuki; Matsunaga, Yuki; Kobayashi, Yayoi; Hirano, Seishiro; Tashiro, Tomoko

2013-12-01

In Japan, people using water from the well contaminated with high-level arsenic developed neurological, mostly cerebellar, symptoms, where diphenylarsinic acid (DPAA) was a major compound. Here, we investigated the adverse effects of developmental exposure to 20mg/l DPAA in drinking water (early period [0-6 weeks of age] and/or late period [7-12]) on behavior and cerebellar development in male rats. In the open field test at 6 weeks of age, early exposure to DPAA significantly increased exploratory behaviors. At 12 weeks of age, late exposure to DPAA similarly increased exploratory behavior independent of the early exposure although a 6-week recovery from DPAA could reverse that change. In the passive avoidance test at 6 weeks of age, early exposure to DPAA significantly decreased the avoidance performance. Even at 12 weeks of age, early exposure to DPAA significantly decreased the test performance, which was independent of the late exposure to DPAA. These results suggest that the DPAA-induced increase in exploratory behavior is transient, whereas the DPAA-induced impairment of passive avoidance is long lasting. At 6 weeks of age, early exposure to DPAA significantly reduced the concentration of cerebellar total glutathione. At 12 weeks of age, late, but not early, exposure to DPAA also significantly reduced the concentration of cerebellar glutathione, which might be a primary cause of oxidative stress. Early exposure to DPAA induced late-onset suppressed expression of NMDAR1 and PSD95 protein at 12 weeks of age, indicating impaired glutamatergic system in the cerebellum of rats developmentally exposed to DPAA.

Surface recombination velocity imaging of wet-cleaned silicon wafers using quantitative heterodyne lock-in carrierography

NASA Astrophysics Data System (ADS)

Sun, Qiming; Melnikov, Alexander; Mandelis, Andreas; Pagliaro, Robert H.

2018-01-01

InGaAs-camera based heterodyne lock-in carrierography (HeLIC) is developed for surface recombination velocity (SRV) imaging characterization of bare (oxide-free) hydrogen passivated Si wafer surfaces. Samples prepared using four different hydrofluoric special-solution etching conditions were tested, and a quantitative assessment of their surface quality vs. queue-time after the hydrogen passivation process was made. The data acquisition time for an SRV image was about 3 min. A "round-trip" frequency-scan mode was introduced to minimize the effects of signal transients on data self-consistency. Simultaneous best fitting of HeLIC amplitude-frequency dependencies at various queue-times was used to guarantee the reliability of resolving surface and bulk carrier recombination/transport properties. The dynamic range of the measured SRV values was established from 0.1 to 100 m/s.

Capillary channel flow experiments aboard the International Space Station

NASA Astrophysics Data System (ADS)

Conrath, M.; Canfield, P. J.; Bronowicki, P. M.; Dreyer, M. E.; Weislogel, M. M.; Grah, A.

2013-12-01

In the near-weightless environment of orbiting spacecraft capillary forces dominate interfacial flow phenomena over unearthly large length scales. In current experiments aboard the International Space Station, partially open channels are being investigated to determine critical flow rate-limiting conditions above which the free surface collapses ingesting bubbles. Without the natural passive phase separating qualities of buoyancy, such ingested bubbles can in turn wreak havoc on the fluid transport systems of spacecraft. The flow channels under investigation represent geometric families of conduits with applications to liquid propellant acquisition, thermal fluids circulation, and water processing for life support. Present and near future experiments focus on transient phenomena and conduit asymmetries allowing capillary forces to replace the role of gravity to perform passive phase separations. Terrestrial applications are noted where enhanced transport via direct liquid-gas contact is desired.

48 CFR 42.002 - Interagency agreements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Interagency agreements. 42... MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES 42.002 Interagency agreements. (a) Agencies shall avoid... agency, through the use of interagency agreements. (b) Subject to the fiscal regulations of the agencies...

48 CFR 42.002 - Interagency agreements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Interagency agreements. 42... MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES 42.002 Interagency agreements. (a) Agencies shall avoid... agency, through the use of interagency agreements. (b) Subject to the fiscal regulations of the agencies...

48 CFR 42.002 - Interagency agreements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Interagency agreements. 42... MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES 42.002 Interagency agreements. (a) Agencies shall avoid... agency, through the use of interagency agreements. (b) Subject to the fiscal regulations of the agencies...

A study of the feasibility and performance of an active/passive imager using silicon focal plane arrays and incoherent continuous wave laser diodes

NASA Astrophysics Data System (ADS)

Vollmerhausen, Richard H.

This dissertation describes an active/passive imager (API) that provides reliable, nighttime, target acquisition in a man-portable package with effective visual range of about 4 kilometers. The reflective imagery is easier to interpret than currently used thermal imagery. Also, in the active mode, the API provides performance equivalent to the big-aperture, thermal systems used on weapons platforms like tanks and attack helicopters. This dissertation describes the research needed to demonstrate both the feasibility and utility of the API. Part of the research describes implementation of a silicon focal plane array (SFPA) capable of both active and passive imaging. The passive imaging mode exceeds the nighttime performance of currently fielded, man-portable sensors. Further, when scene illumination is insufficient for passive imaging, the low dark current of SFPA makes it possible to use continuous wave laser diodes (CWLD) to add an active imaging mode. CWLD have advantages of size, efficiency, and improved eye safety when compared to high peak-power diodes. Because of the improved eye safety, the API provides user-demanded features like video output and extended range gates in the active as well as passive imaging modes. Like any other night vision device, the API depends on natural illumination of the scene for passive operation. Although it has been known for decades that "starlight" illumination is actually from diffuse airglow emissions, the research described in this dissertation provides the first estimates of the global and temporal variation of ground illumination due to airglow. A third related element of the current research establishes the impact of atmospheric aerosols on API performance. We know from day experience that atmospheric scattering of sunlight into the imager line-of-sight can blind the imager and drastically degrade performance. Atmospheric scattering of sunlight is extensively covered in the literature. However, previous literature did not cover the impact of atmospheric scattering when the target is diffusely illuminated by airglow.

High-Resolution Enhanced Product based on SMAP Active-Passive Approach using Sentinel 1A and 1B SAR Data

NASA Astrophysics Data System (ADS)

Das, N. N.; Entekhabi, D.; Dunbar, R. S.; Colliander, A.; Kim, S.; Yueh, S. H.

2017-12-01

NASA's Soil Moisture Active Passive (SMAP) mission was launched on January 31st, 2015. SMAP utilizes an L-band radar and radiometer sharing a rotating 6-meter mesh reflector antenna. However, on July 7th, 2015, the SMAP radar encountered an anomaly and is currently inoperable. During the SMAP post-radar phase, many ways are explored to recover the high-resolution soil moisture capability of the SMAP mission. One of the feasible approaches is to substitute the SMAP radar with other available SAR data. Sentinel 1A/1B SAR data is found more suitable for combining with the SMAP radiometer data because of almost similar orbit configuration that allow overlapping of their swaths with minimal time difference that is key to the SMAP active-passive algorithm. The Sentinel SDV mode acquisition also provide the co-pol and x-pol observations required for the SMAP active-passive algorithm. Some differences do exist between the SMAP SAR data and Sentinel SAR data, they are mainly: 1) Sentinel has C-band SAR and SMAP is L-band; 2) Sentinel has multi incidence angle within its swath, where as SMAP has single incidence angle; and 3) Sentinel swath width is 300 km as compare to SMAP 1000 km swath width. On any given day, the narrow swath width of the Sentinel observations will significantly reduce the spatial coverage of SMAP active-passive approach as compared to the SMAP swath coverage. The temporal resolution (revisit interval) is also degraded from 3-days to 12-days when Sentinel 1A/1B data is used. One bright side of using Sentinel 1A/1B data in the SMAP active-passive algorithm is the potential of obtaining the disaggregated brightness temperature and soil moisture at much finer spatial resolutions of 3 km and 9 km with optimal accuracy. The Beta version of SMAP-Sentinel Active-Passive high-resolution product will be made available to public in September 2017.

DFL, Canada's Space AIT Facilities - Current and Planned Capabilities

NASA Astrophysics Data System (ADS)

Singhal, R.; Mishra, S.; Choueiry, E.; Dumoulin, J.; Ahmed, S.

2004-08-01

The David Florida Laboratory (DFL) of the Canadian Space Agency is the Canadian national ISO 9001:2000 registered facility for the assembly, integration, and (environmental) testing of space hardware. This paper briefly describes the three main qualification facilities: Structural Qualification Facilities (SQF); Radio Frequency Qualification Facilities (RFQF); and Thermal Qualification Facilities (TQF). The paper also describes the planned/new upgrades/improvements to the DFL's existing capabilities. These include: cylindrical near-field antenna measurement system, current capabilities in multi-frequency multi-band passive intermodulation (PIM) measurement; combined thermal/vibration test facility, improvement in efficiency and performance of the photogrammetry capability, acquisition of an additional mass properties measurement system for small and micro-satellites; combined control and data acquisition system for all existing thermal vacuum facilities, plus a new automatic thermal control system and hypobaric chamber.

Clozapine and Olanzapine Exhibit an Intrinsic Anxiolytic Property in Two Conditioned Fear Paradigms: Contrast with Haloperidol and Chlordiazepoxide

PubMed Central

Mead, Alexa; Li, Ming; Kapur, Shitij

2008-01-01

Psychotic fear and anxiety disturbances are seen at a relatively high frequency in patients with schizophrenia. Atypical antipsychotics are believed to show superior efficacy in reducing these symptoms. However, clinical and preclinical evidence regarding their anxiolytic efficacy has been mixed. In this study, we evaluated the possible anxiolytic property of two atypicals clozapine and olanzapine and compared them with typical haloperidol and chlordiazepoxide (a prototype of sedative-anxiolytic drug) in two preclinical models of fear. In Experiment 1, we used a fear-induced passive avoidance and conditioned place aversion paradigm and examined the effects of clozapine (20 mg/kg, sc), haloperidol (0.05 mg/kg, sc) and chlordiazepoxide (10 mg/kg, ip). In Experiments 2 and 3, we used a two-way active avoidance conditioning paradigm and further compared the effects of clozapine (20 mg/kg, sc), haloperidol (0.05 mg/kg, sc), chlordiazepoxide (10 mg/kg, ip) and three doses of olanzapine (0.5, 1.0, and 2.0 mg/kg, sc). Results show that clozapine and chlordiazepoxide, but not haloperidol, significantly attenuated the shock conditioning-induced place aversion, decreased the amount of defecations and the number of the 22 kHz vocalizations. Clozapine also reduced the shock conditioning-induced hyperthermia. Similar to clozapine, olanzapine also significantly decreased the amount of defecations and reduced the shock conditioning-induced hyperthermia, but it did not inhibit the 22 kHz vocalizations. This study demonstrates that clozapine and olanzapine possess an intrinsic anxiolytic property, which is not attributable to its superior anti-“psychotic” effect or its favorable effects on motor functions or learning and memory processes. These findings also suggest that the combined use of passive avoidance and active avoidance conditioning models can be useful in better differentiating typical and atypical antipsychotics as well as anxiolytics. PMID:18547622

Environmental transmission of generalized anxiety disorder from parents to children: worries, experiential avoidance, and intolerance of uncertainty

PubMed Central

Aktar, Evin; Nikolić, Milica; Bögels, Susan M.

2017-01-01

Generalized anxiety disorder (GAD) runs in families. Building on recent theoretical approaches, this review focuses on potential environmental pathways for parent-to-child transmission of GAD. First, we address child acquisition of a generalized pattern of fearful/anxious and avoidant responding to potential threat from parents via verbal information and via modeling. Next, we address how parenting behaviors may contribute to maintenance of fearful/anxious and avoidant reactions in children. Finally, we consider intergenerational transmission of worries as a way of coping with experiential avoidance of strong negative emotions and with intolerance of uncertainty. We conclude that parents with GAD may bias their children's processing of potential threats in the environment by conveying the message that the world is not safe, that uncertainty is intolerable, that strong emotions should be avoided, and that worry helps to cope with uncertainty, thereby transmitting cognitive styles that characterize GAD. Our review highlights the need for research on specific pathways for parent-to-child transmission of GAD. PMID:28867938

Environmental transmission of generalized anxiety disorder from parents to children: worries, experiential avoidance, and intolerance of uncertainty.

PubMed

Aktar, Evin; Nikolić, Milica; Bögels, Susan M

2017-06-01

Generalized anxiety disorder (GAD) runs in families. Building on recent theoretical approaches, this review focuses on potential environmental pathways for parent-to-child transmission of GAD. First, we address child acquisition of a generalized pattern of fearful/anxious and avoidant responding to potential threat from parents via verbal information and via modeling. Next, we address how parenting behaviors may contribute to maintenance of fearful/anxious and avoidant reactions in children. Finally, we consider intergenerational transmission of worries as a way of coping with experiential avoidance of strong negative emotions and with intolerance of uncertainty. We conclude that parents with GAD may bias their children's processing of potential threats in the environment by conveying the message that the world is not safe, that uncertainty is intolerable, that strong emotions should be avoided, and that worry helps to cope with uncertainty, thereby transmitting cognitive styles that characterize GAD. Our review highlights the need for research on specific pathways for parent-to-child transmission of GAD.

Passive band-gap reconfiguration born from bifurcation asymmetry.

PubMed

Bernard, Brian P; Mann, Brian P

2013-11-01

Current periodic structures are constrained to have fixed energy transmission behavior unless active control or component replacement is used to alter their wave propagation characteristics. The introduction of nonlinearity to generate multiple stable equilibria is an alternative strategy for realizing distinct energy propagation behaviors. We investigate the creation of a reconfigurable band-gap system by implementing passive switching between multiple stable states of equilibrium, to alter the level of energy attenuation in response to environmental stimuli. The ability to avoid potentially catastrophic loads is demonstrated by tailoring the bandpass and band-gap regions to coalesce for two stable equilibria and varying an external load parameter to trigger a bifurcation. The proposed phenomenon could be utilized in remote or autonomous applications where component modifications and active control are impractical.

Inbreeding and inbreeding avoidance in wild giant pandas.

PubMed

Hu, Yibo; Nie, Yonggang; Wei, Wei; Ma, Tianxiao; Van Horn, Russell; Zheng, Xiaoguang; Swaisgood, Ronald R; Zhou, Zhixin; Zhou, Wenliang; Yan, Li; Zhang, Zejun; Wei, Fuwen

2017-10-01

Inbreeding can have negative consequences on population and individual fitness, which could be counteracted by inbreeding avoidance mechanisms. However, the inbreeding risk and inbreeding avoidance mechanisms in endangered species are less studied. The giant panda, a solitary and threatened species, lives in many small populations and suffers from habitat fragmentation, which may aggravate the risk of inbreeding. Here, we performed long-term observations of reproductive behaviour, sampling of mother-cub pairs and large-scale genetic analyses on wild giant pandas. Moderate levels of inbreeding were found in 21.1% of mating pairs, 9.1% of parent pairs and 7.7% of panda cubs, but no high-level inbreeding occurred. More significant levels of inbreeding may be avoided passively by female-biased natal dispersal rather than by breeding dispersal or active relatedness-based mate choice mechanisms. The level of inbreeding in giant pandas is greater than expected for a solitary mammal and thus warrants concern for potential inbreeding depression, particularly in small populations isolated by continuing habitat fragmentation, which will reduce female dispersal and increase the risk of inbreeding. © 2017 John Wiley & Sons Ltd.

Effective Surface Passivation of InP Nanowires by Atomic-Layer-Deposited Al2O3 with POx Interlayer.

PubMed

Black, L E; Cavalli, A; Verheijen, M A; Haverkort, J E M; Bakkers, E P A M; Kessels, W M M

2017-10-11

III/V semiconductor nanostructures have significant potential in device applications, but effective surface passivation is critical due to their large surface-to-volume ratio. For InP such passivation has proven particularly difficult, with substantial depassivation generally observed following dielectric deposition on InP surfaces. We present a novel approach based on passivation with a phosphorus-rich interfacial oxide deposited using a low-temperature process, which is critical to avoid P-desorption. For this purpose we have chosen a PO x layer deposited in a plasma-assisted atomic layer deposition (ALD) system at room temperature. Since PO x is known to be hygroscopic and therefore unstable in atmosphere, we encapsulate this layer with a thin ALD Al 2 O 3 capping layer to form a PO x /Al 2 O 3 stack. This passivation scheme is capable of improving the photoluminescence (PL) efficiency of our state-of-the-art wurtzite (WZ) InP nanowires by a factor of ∼20 at low excitation. If we apply the rate equation analysis advocated by some authors, we derive a PL internal quantum efficiency (IQE) of 75% for our passivated wires at high excitation. Our results indicate that it is more reliable to calculate the IQE as the ratio of the integrated PL intensity at room temperature to that at 10 K. By this means we derive an IQE of 27% for the passivated wires at high excitation (>10 kW cm -2 ), which constitutes an unprecedented level of performance for undoped InP nanowires. This conclusion is supported by time-resolved PL decay lifetimes, which are also shown to be significantly higher than previously reported for similar wires. The passivation scheme displays excellent long-term stability (>7 months) and is additionally shown to substantially improve the thermal stability of InP surfaces (>300 °C), significantly expanding the temperature window for device processing. Such effective surface passivation is a key enabling technology for InP nanowire devices such as nanolasers and solar cells.

Effective Surface Passivation of InP Nanowires by Atomic-Layer-Deposited Al2O3 with POx Interlayer

PubMed Central

2017-01-01

III/V semiconductor nanostructures have significant potential in device applications, but effective surface passivation is critical due to their large surface-to-volume ratio. For InP such passivation has proven particularly difficult, with substantial depassivation generally observed following dielectric deposition on InP surfaces. We present a novel approach based on passivation with a phosphorus-rich interfacial oxide deposited using a low-temperature process, which is critical to avoid P-desorption. For this purpose we have chosen a POx layer deposited in a plasma-assisted atomic layer deposition (ALD) system at room temperature. Since POx is known to be hygroscopic and therefore unstable in atmosphere, we encapsulate this layer with a thin ALD Al2O3 capping layer to form a POx/Al2O3 stack. This passivation scheme is capable of improving the photoluminescence (PL) efficiency of our state-of-the-art wurtzite (WZ) InP nanowires by a factor of ∼20 at low excitation. If we apply the rate equation analysis advocated by some authors, we derive a PL internal quantum efficiency (IQE) of 75% for our passivated wires at high excitation. Our results indicate that it is more reliable to calculate the IQE as the ratio of the integrated PL intensity at room temperature to that at 10 K. By this means we derive an IQE of 27% for the passivated wires at high excitation (>10 kW cm–2), which constitutes an unprecedented level of performance for undoped InP nanowires. This conclusion is supported by time-resolved PL decay lifetimes, which are also shown to be significantly higher than previously reported for similar wires. The passivation scheme displays excellent long-term stability (>7 months) and is additionally shown to substantially improve the thermal stability of InP surfaces (>300 °C), significantly expanding the temperature window for device processing. Such effective surface passivation is a key enabling technology for InP nanowire devices such as nanolasers and solar cells. PMID:28885032

Relationship between changes in rat behavior and integral biochemical indexes determined by laser correlation spectroscopy after photothrombosis of the prefrontal cortex.

PubMed

Romanova, G A; Shakova, F M; Kovaleva, O I; Pivovarov, V V; Khlebnikova, N N; Karganov, M Yu

2004-02-01

Experiments on rats showed that Noopept improved retention and retrieval of conditioned passive avoidance response after phototrombosis of the prefrontal cortex (a procedure impairing retention of memory traces). The impairment of mnesic functions was accompanied by changes in integral biochemical indexes of the plasma determined by laser correlation spectroscopy. Treatment of behavioral disorders with Noopepet normalized biochemical indexes.

Nootropic and antiamnestic effects of tenoten (pediatric formulation) in immature rat pups.

PubMed

Voronina, T A; Molodavkin, G M; Borodavkina, M V; Kheyfets, I A; Dugina, Yu L; Sergeeva, S A

2009-09-01

The antiamnestic effects of tenoten (pediatric formulation) was demonstrated on the model of scopolamine-induced amnesia of passive avoidance reflex and the nootropic effect of this preparation was demonstrated on the model of incomplete conditioning and in rat pups with experimental attention deficit syndrome. The efficiency of the preparation was comparable to that of piracetam and phenibut and even surpassed it by some parameters.

Different Involvement of Type 1, 2, and 3 Ryanodine Receptors in Memory Processes

ERIC Educational Resources Information Center

Galeotti, Nicoletta; Quattrone, Alessandro; Vivoli, Elisa; Norcini, Monica; Bartolini, Alessandro; Ghelardini, Carla

2008-01-01

The administration of the ryanodine receptor (RyR) agonist 4-Cmc (0.003-9 nmol per mouse intracerebroventricularly [i.c.v.]) ameliorated memory functions, whereas the RyR antagonist ryanodine (0.0001-1 nmol per mouse i.c.v.) induced amnesia in the mouse passive avoidance test. The role of the type 1, 2, and 3 RyR isoforms in memory processes was…

A stereo-vision hazard-detection algorithm to increase planetary lander autonomy

NASA Astrophysics Data System (ADS)

Woicke, Svenja; Mooij, Erwin

2016-05-01

For future landings on any celestial body, increasing the lander autonomy as well as decreasing risk are primary objectives. Both risk reduction and an increase in autonomy can be achieved by including hazard detection and avoidance in the guidance, navigation, and control loop. One of the main challenges in hazard detection and avoidance is the reconstruction of accurate elevation models, as well as slope and roughness maps. Multiple methods for acquiring the inputs for hazard maps are available. The main distinction can be made between active and passive methods. Passive methods (cameras) have budgetary advantages compared to active sensors (radar, light detection and ranging). However, it is necessary to proof that these methods deliver sufficiently good maps. Therefore, this paper discusses hazard detection using stereo vision. To facilitate a successful landing not more than 1% wrong detections (hazards that are not identified) are allowed. Based on a sensitivity analysis it was found that using a stereo set-up at a baseline of ≤ 2 m is feasible at altitudes of ≤ 200 m defining false positives of less than 1%. It was thus shown that stereo-based hazard detection is an effective means to decrease the landing risk and increase the lander autonomy. In conclusion, the proposed algorithm is a promising candidate for future landers.

The memory-ameliorating effects of Artemisia princeps var. orientalis against cholinergic dysfunction in mice.

PubMed

Liu, Xiaotong; Kim, Dong Hyun; Kim, Jong Min; Park, Se Jin; Cai, Mudan; Jang, Dae Sik; Ryu, Jong Hoon

2012-01-01

Artemisia princeps var. orientalis (Compositae) is widely distributed in China, Japan and Korea and is known to have anti-inflammatory and anti-oxidative activities. The ethyl acetate fraction of ethanolic extract of A. princeps var. orientalis (AEA) was found to inhibit acetylcholinesterase activity in a dose-dependent manner in vitro (IC(50) value: 541.4 ± 67.5 μg/ml). Therefore, we investigated the effects of AEA on scopolamine-induced learning and memory impairment using the passive avoidance, the Y-maze, and the Morris water maze tasks in mice. AEA (100 or 200 mg/kg, p.o.) significantly ameliorated scopolamine-induced cognitive impairments in the passive avoidance and Y-maze tasks (p < 0.05). In the Morris water maze task, AEA (200 mg/kg, p.o.) significantly shortened escape latencies in training trials and increased both swimming time spent in the target zone and probe crossing numbers during the probe trial as compared with scopolamine-treated mice (p < 0.05). Additionally, the ameliorating effect of AEA on scopolamine-induced memory impairment was antagonized by a subeffective dose of MK-801. These results suggest that AEA could be an effective treatment against cholinergic dysfunction and its effect is mediated by the enhancement of the cholinergic neurotransmitter system via NMDA receptor signaling or acetylcholinesterase inhibition.

Neuroprotective effects of the polyphenolic antioxidant agent, Curcumin, against homocysteine-induced cognitive impairment and oxidative stress in the rat.

PubMed

Ataie, Amin; Sabetkasaei, Masoumeh; Haghparast, Abbas; Moghaddam, Akbar Hajizadeh; Kazeminejad, Behrang

2010-10-01

Aging is the major risk factor for neurodegenerative diseases and oxidative stress is involved in the pathophysiology of these diseases. In this study, the possible antioxidant and neuroprotective properties of the polyphenolic antioxidant compound, Curcumin against homocysteine (Hcy) neurotoxicity was investigated. Curcumin (5 and 50mg/kg) was injected intraperitoneally once daily for a period of 10 days beginning 5 days prior to Hcy (0.2 micromol/microl) intrahippocampal injection in rats. Biochemical and behavioral studies, including passive avoidance learning and locomotor activity tests were studied 24h after the last Curcumin or its vehicle injection. We detected Malondialdehyde (MDA) and Super oxide anion (SOA) in rats' hippocampi. Results indicated that Hcy could induce lipid peroxidation and increase MDA and SOA levels in rats' hippocampi. Additionally, Hcy impaired memory retention in passive avoidance learning test. However, Curcumin treatment decreased MDA and SOA levels significantly as well as improved learning and memory in rats. Histopathological analysis also indicated that Hcy could decrease hippocampus cell count and Curcumin inhibited this toxic effect. These results suggest that Hcy may induce lipid peroxidation in rats' hippocampi and polyphenol treatment (Curcumin) improved learning and memory deficits by protecting the nervous system against Hcy toxicity. (c) 2010 Elsevier Inc. All rights reserved.

P7C3 Attenuates the Scopolamine-Induced Memory Impairments in C57BL/6J Mice.

PubMed

Jiang, Bo; Song, Lu; Huang, Chao; Zhang, Wei

2016-05-01

Memory impairment is the most common symptom in patients with Alzheimer's disease. The purpose of this study is to evaluate the memory enhancing effects of P7C3, a recently identified compound with robust proneurogenic and neuroprotective effects, on the cognitive impairment induced by scopolamine, a muscarinic acetylcholine receptor antagonist. Different behavior tests including the Y-maze, Morris water maze, and passive avoidance tests were performed to measure cognitive functions. Scopolamine significantly decreased the spontaneous alternation and step-through latency of C57BL/6J mice in Y-maze test and passive avoidance test, whereas increased the time of mice spent to find the hidden platform in Morris water maze test. Importantly, intraperitoneal administration of P7C3 effectively reversed those Scopolamine-induced cognitive impairments in C57BL/6J mice. Furthermore, P7C3 treatment significantly enhanced the level of brain-derived neurotrophic factor (BDNF) signaling pathway in the cortex and hippocampus, and the usage of selective BDNF signaling inhibitor fully blocked the anti-amnesic effects of P7C3. Therefore, these findings suggest that P7C3 could improve the scopolamine-induced learning and memory impairment possibly through activation of BDNF signaling pathway, thereby exhibiting a cognition-enhancing potential.

NOAA PORTS PROGRAM

Science.gov Websites

greater danger near shore or any shallow waters? NOAA PORTS PROGRAM The Physical Oceanographic Real-Time navigation by providing ship masters and pilots with accurate real-time information required to avoid data acquisition and dissemination systems that provide real-time water levels, currents, and other

On Normal and Autistic Pronouns

ERIC Educational Resources Information Center

Fay, Warren H.

1971-01-01

An alternative to the ego-based explanations for the autistic child's characteristic patterns of pronominal reversals and avoidances is an approach based on studies of echolalia which considers grammatical aspects of acquisition, reversal, and nonreversal. Focus is consequently shifted from primacy of expressive I to comprehension of you/me…

Eliminating Unpredictable Variation through Iterated Learning

ERIC Educational Resources Information Center

Smith, Kenny; Wonnacott, Elizabeth

2010-01-01

Human languages may be shaped not only by the (individual psychological) processes of language acquisition, but also by population-level processes arising from repeated language learning and use. One prevalent feature of natural languages is that they avoid unpredictable variation. The current work explores whether linguistic predictability might…

Antibody blocks acquisition of bacterial colonization through agglutination

PubMed Central

Roche, A. M.; Richard, A. L.; Rahkola, J. T.; Janoff, E. N.; Weiser, J. N.

2014-01-01

Invasive infection often begins with asymptomatic colonization of mucosal surfaces. A murine model of bacterial colonization with Streptococcus pneumoniae was used to study the mechanism for mucosal protection by immunoglobulin. In previously colonized immune mice, bacteria were rapidly sequestered within large aggregates in the nasal lumen. To further examine the role of bacterial agglutination in protection by specific antibodies, mice were passively immunized with IgG purified from anti-pneumococcal sera or pneumococcal type-specific monoclonal human IgA (hIgA1 or hIgA2). Systemically-delivered IgG accessed the mucosal surface and blocked acquisition of colonization and transmission between littermates. Optimal protection by IgG was independent of Fc fragment and complement and, therefore, did not involve an opsonophagocytic mechanism. Enzymatic digestion or reduction of IgG prior to administration showed that protection required divalent binding that maintained its agglutinating effect. Divalent hIgA1 is cleaved by the pneumococcal member of a family of bacterial proteases that generate monovalent Fabα fragments. Thus, passive immunization with hIgA1 blocked colonization by an IgA1-protease deficient mutant (agglutinated), but not the protease-producing wild-type parent (not agglutinated), whereas protease-resistant hIgA2 agglutinated and blocked colonization by both. Our findings highlight the importance of agglutinating antibodies in mucosal defense and reveal how successful pathogens evade this effect. PMID:24962092

Magnetic Field Response Measurement Acquisition System

NASA Technical Reports Server (NTRS)

Woodard, Stanley E.; Taylor,Bryant D.; Shams, Qamar A.; Fox, Robert L.

2007-01-01

This paper presents a measurement acquisition method that alleviates many shortcomings of traditional measurement systems. The shortcomings are a finite number of measurement channels, weight penalty associated with measurements, electrical arcing, wire degradations due to wear or chemical decay and the logistics needed to add new sensors. Wire degradation has resulted in aircraft fatalities and critical space launches being delayed. The key to this method is the use of sensors designed as passive inductor-capacitor circuits that produce magnetic field responses. The response attributes correspond to states of physical properties for which the sensors measure. Power is wirelessly provided to the sensing element by using Faraday induction. A radio frequency antenna produces a time-varying magnetic field used to power the sensor and receive the magnetic field response of the sensor. An interrogation system for discerning changes in the sensor response frequency, resistance and amplitude has been developed and is presented herein. Multiple sensors can be interrogated using this method. The method eliminates the need for a data acquisition channel dedicated to each sensor. The method does not require the sensors to be near the acquisition hardware. Methods of developing magnetic field response sensors and the influence of key parameters on measurement acquisition are discussed. Examples of magnetic field response sensors and the respective measurement characterizations are presented. Implementation of this method on an aerospace system is discussed.

Stabilizing a graphene platform toward discrete components

NASA Astrophysics Data System (ADS)

Mzali, Sana; Montanaro, Alberto; Xavier, Stéphane; Servet, Bernard; Mazellier, Jean-Paul; Bezencenet, Odile; Legagneux, Pierre; Piquemal-Banci, Maëlis; Galceran, Regina; Dlubak, Bruno; Seneor, Pierre; Martin, Marie-Blandine; Hofmann, Stephan; Robertson, John; Cojocaru, Costel-Sorin; Centeno, Alba; Zurutuza, Amaia

2016-12-01

We report on statistical analysis and consistency of electrical performances of devices based on a large scale passivated graphene platform. More than 500 graphene field effect transistors (GFETs) based on graphene grown by chemical vapor deposition and transferred on 4 in. SiO2/Si substrates were fabricated and tested. We characterized the potential of a two-step encapsulation process including an Al2O3 protection layer to avoid graphene contamination during the lithographic process followed by a final Al2O3 passivation layer subsequent to the GFET fabrication. Devices were investigated for occurrence and reproducibility of conductance minimum related to the Dirac point. While no conductance minimum was observed in unpassivated devices, 75% of the passivated transistors exhibited a clear conductance minimum and low hysteresis. The maximum of the device number distribution corresponds to a residual doping below 5 × 1011 cm-2 (0.023 V/nm). This yield shows that GFETs integrating low-doped graphene and exhibiting small hysteresis in the transfer characteristics can be envisaged for discrete components, with even further potential for low power driven electronics.

Optimization of Controllable Factors in the Aluminum Silicon Eutectic Paste and Rear Silicon Nitride Mono-Passivation Layer of PERC Solar Cells

NASA Astrophysics Data System (ADS)

Park, Sungeun; Park, Hyomin; Kim, Dongseop; Yang, JungYup; Lee, Dongho; Kim, Young-Su; Kim, Hyun-Jong; Suh, Dongchul; Min, Byoung Koun; Kim, Kyung Nam; Park, Se Jin; Kim, Donghwan; Lee, Hae-Seok; Nam, Junggyu; Kang, Yoonmook

2018-05-01

Passivated emitter and rear contact (PERC) is a promising technology owing to high efficiency can be achieved with p-type wafer and their easily applicable to existing lines. In case of using p-type mono wafer, 0.5-1% efficiency increase is expected with PERC technologies compared to existing Al BSF solar cells, while for multi-wafer solar cells it is 0.5-0.8%. We addressed the optimization of PERC solar cells using the Al paste. The paste was prepared from the aluminum-silicon alloy with eutectic composition to avoid the formation of voids that degrade the open-circuit voltage. The glass frit of the paste was changed to improve adhesion. Scanning electron microscopy revealed voids and local back surface field between the aluminum electrode and silicon base. We confirmed the conditions on the SiNx passivation layer for achieving higher efficiency and better adhesion for long-term stability. The cell characteristics were compared across cells containing different pastes. PERC solar cells with the Al/Si eutectic paste exhibited the efficiency of 19.6%.

Moving to stay in place: behavioral mechanisms for coexistence of African large carnivores.

PubMed

Vanak, Abi Tamim; Fortin, Daniel; Thaker, Maria; Ogden, Monika; Owen, Cailey; Greatwood, Sophie; Slotow, Rob

2013-11-01

Most ecosystems have multiple predator species that not only compete for shared prey, but also pose direct threats to each other. These intraguild interactions are key drivers of carnivore community structure, with ecosystem-wide cascading effects. Yet, behavioral mechanisms for coexistence of multiple carnivore species remain poorly understood. The challenges of studying large, free-ranging carnivores have resulted in mainly coarse-scale examination of behavioral strategies without information about all interacting competitors. We overcame some of these challenges by examining the concurrent fine-scale movement decisions of almost all individuals of four large mammalian carnivore species in a closed terrestrial system. We found that the intensity ofintraguild interactions did not follow a simple hierarchical allometric pattern, because spatial and behavioral tactics of subordinate species changed with threat and resource levels across seasons. Lions (Panthera leo) were generally unrestricted and anchored themselves in areas rich in not only their principal prey, but also, during periods of resource limitation (dry season), rich in the main prey for other carnivores. Because of this, the greatest cost (potential intraguild predation) for subordinate carnivores was spatially coupled with the highest potential benefit of resource acquisition (prey-rich areas), especially in the dry season. Leopard (P. pardus) and cheetah (Acinonyx jubatus) overlapped with the home range of lions but minimized their risk using fine-scaled avoidance behaviors and restricted resource acquisition tactics. The cost of intraguild competition was most apparent for cheetahs, especially during the wet season, as areas with energetically rewarding large prey (wildebeest) were avoided when they overlapped highly with the activity areas of lions. Contrary to expectation, the smallest species (African wild dog, Lycaon pictus) did not avoid only lions, but also used multiple tactics to minimize encountering all other competitors. Intraguild competition thus forced wild dogs into areas with the lowest resource availability year round. Coexistence of multiple carnivore species has typically been explained by dietary niche separation, but our multi-scaled movement results suggest that differences in resource acquisition may instead be a consequence of avoiding intraguild competition. We generate a more realistic representation of hierarchical behavioral interactions that may ultimately drive spatially explicit trophic structures of multi-predator communities.

PSD Camera Based Position and Posture Control of Redundant Robot Considering Contact Motion

NASA Astrophysics Data System (ADS)

Oda, Naoki; Kotani, Kentaro

The paper describes a position and posture controller design based on the absolute position by external PSD vision sensor for redundant robot manipulator. The redundancy enables a potential capability to avoid obstacle while continuing given end-effector jobs under contact with middle link of manipulator. Under contact motion, the deformation due to joint torsion obtained by comparing internal and external position sensor, is actively suppressed by internal/external position hybrid controller. The selection matrix of hybrid loop is given by the function of the deformation. And the detected deformation is also utilized in the compliant motion controller for passive obstacle avoidance. The validity of the proposed method is verified by several experimental results of 3link planar redundant manipulator.

Development of data acquisition and over-current protection systems for a suppressor-grid current with a neutral-beam ion source

NASA Astrophysics Data System (ADS)

Wei, LIU; Chundong, HU; Sheng, LIU; Shihua, SONG; Jinxin, WANG; Yan, WANG; Yuanzhe, ZHAO; Lizhen, LIANG

2017-12-01

Neutral beam injection is one of the effective auxiliary heating methods in magnetic-confinement-fusion experiments. In order to acquire the suppressor-grid current signal and avoid the grid being damaged by overheating, a data acquisition and over-current protection system based on the PXI (PCI eXtensions for Instrumentation) platform has been developed. The system consists of a current sensor, data acquisition module and over-current protection module. In the data acquisition module, the acquired data of one shot will be transferred in isolation and saved in a data-storage server in a txt file. It can also be recalled using NBWave for future analysis. The over-current protection module contains two modes: remote and local. This gives it the function of setting a threshold voltage remotely and locally, and the forbidden time of over-current protection also can be set by a host PC in remote mode. Experimental results demonstrate that the data acquisition and over-current protection system has the advantages of setting forbidden time and isolation transmission.

Role of "the frame cycle time" in portal dose imaging using an aS500-II EPID.

PubMed

Al Kattar Elbalaa, Zeina; Foulquier, Jean Noel; Orthuon, Alexandre; Elbalaa, Hanna; Touboul, Emmanuel

2009-09-01

This paper evaluates the role of an acquisition parameter, the frame cycle time "FCT", in the performance of an aS500-II EPID. The work presented rests on the study of the Varian EPID aS500-II and the image acquisition system 3 (IAS3). We are interested in integrated acquisition using asynchronous mode. For better understanding the image acquisition operation, we investigated the influence of the "frame cycle time" on the speed of acquisition, the pixel value of the averaged gray-scale frame and the noise, using 6 and 15MV X-ray beams and dose rates of 1-6Gy/min on 2100 C/D Linacs. In the integrated mode not synchronized to beam pulses, only one parameter the frame cycle time "FCT" influences the pixel value. The pixel value of the averaged gray-scale frame is proportional to this parameter. When the FCT <55ms (speed of acquisition V(f/s)>18 frames/s), the speed of acquisition becomes unstable and leads to a fluctuation of the portal dose response. A timing instability and saturation are detected when the dose per frame exceeds 1.53MU/frame. Rules were deduced to avoid saturation and to optimize this dosimetric mode. The choice of the acquisition parameter is essential for the accurate portal dose imaging.

48 CFR 2452.209-70 - Potential organizational conflicts of interest.

Code of Federal Regulations, 2011 CFR

2011-10-01

... conflicts of interest. 2452.209-70 Section 2452.209-70 Federal Acquisition Regulations System DEPARTMENT OF... relevant facts that show how its organizational structure and/or management systems limit its knowledge of... and how that structure or system would avoid or mitigate such organizational conflict. (d) No award...

Seeking Positive Experiences Can Produce Illusory Correlations

ERIC Educational Resources Information Center

Denrell, Jerker; Le Mens, Gael

2011-01-01

Individuals tend to select again alternatives about which they have positive impressions and to avoid alternatives about which they have negative impressions. Here we show how this sequential sampling feature of the information acquisition process leads to the emergence of an illusory correlation between estimates of the attributes of…

FY 2003 Acquisition and Technology Division Annual Report

DTIC Science & Technology

2004-08-01

readiness. The Army will be better able to preserve readiness, save money, and avoid bad decisions by knowing which alternative cleaning products meet its...USAEC and ATC are leading an initiative to comprehensively test several cleaning products and gather data the Army and other DoD services can use to

FY 2002 Pollution Prevention/Compliance, Acquisition and Technology Division Annual Report

DTIC Science & Technology

2003-03-03

will be better able to preserve readiness, save money and avoid bad decisions by knowing which alternative cleaning products meet its stringent...partnership with commodity managers, USAEC and ATC are leading an initiative to compre- hensively test several cleaning products and gather data the Army

FY 2001 Pollution Prevention/Compliance, Acquisition and Technology Division Annual Report

DTIC Science & Technology

2002-02-15

readiness, save money and avoid bad decisions by knowing which alternative cleaning products meet its stringent requirements for performance, soldier...several cleaning products and gather data the Army and other DoD services can use to make procurement and usage decisions. The current program test

48 CFR 3.601 - Policy.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Policy. 3.601 Section 3... Controlled by Them 3.601 Policy. (a) Except as specified in 3.602, a contracting officer shall not knowingly... substantially owned or controlled by one or more Government employees. This policy is intended to avoid any...

48 CFR 3.601 - Policy.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Policy. 3.601 Section 3... Controlled by Them 3.601 Policy. (a) Except as specified in 3.602, a contracting officer shall not knowingly... substantially owned or controlled by one or more Government employees. This policy is intended to avoid any...

Motivation to Avoid Loss Improves Implicit Skill Performance

ERIC Educational Resources Information Center

Chon, Danbee; Thompson, Kelsey R.; Reber, Paul J.

2018-01-01

Implicit learning reflects learning from experience that occurs without intention or awareness of the information acquired and is hypothesized to contribute to skill acquisition by improving performance with practice. The role of motivation has not been examined because this kind of memory is represented outside awareness. We manipulated…

76 FR 28060 - Regional Habitat Conservation Plan, Hays County, TX

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-13

... alternative features the acquisition of a modestly sized, pre-determined preserve system and limits the amount... under Alternative B, this alternative involves a conservation program that utilizes a pre-determined..., adaptive management, and other strategies designed to avoid and minimize harm to the covered species and...

Avoidance of Phycomyces in a controlled environment.

PubMed Central

Meyer, P W; Matus, I J; Berg, H C

1987-01-01

The sporangiophore of the fungus Phycomyces bends away from nearby objects without ever touching them. It has been thought that these objects act as aerodynamic obstacles that damp random winds, thereby generating asymmetric distributions of a growth-promoting gas emitted by the growth zone. In the interest of testing this hypothesis, we studied avoidance in an environmental chamber in which convection was suppressed by a shallow thermal gradient. We also controlled pressure, temperature, and relative humidity of the air, electrostatic charge, and ambient light. A protocol was established that yielded avoidance rates constant from sporangiophore to sporangiophore to within +/- 10%. We found that avoidance occurred at normal rates in the complete absence of random winds. The rates were smaller at 100% than at lower values of relative humidity, but not by much. Remarkably, at a distance as great as 0.5 mm, avoidance from a 30-micron diam glass fiber (aligned parallel to the sporangiophore) was about the same as that from a planar glass sheet. However, the rate for the fiber fell more rapidly with distance. The rate for the sheet remained nearly constant out to approximately 4 mm. We conclude that avoidance depends either on adsorption by the barrier of a growth-inhibiting substance or emission by the barrier of a growth-promoting substance; it cannot occur by passive reflection. Models that can explain these effects are analyzed in the Appendix. PMID:3567313

Boron transport in plants: co-ordinated regulation of transporters

PubMed Central

Miwa, Kyoko; Fujiwara, Toru

2010-01-01

Background The essentiality of boron (B) for plant growth was established >85 years ago. In the last decade, it has been revealed that one of the physiological roles of B is cross-linking the pectic polysaccharide rhamnogalacturonan II in primary cell walls. Borate cross-linking of pectic networks serves both for physical strength of cell walls and for cell adhesion. On the other hand, high concentrations of B are toxic to plant growth. To avoid deficiency and toxicity problems, it is important for plants to maintain their tissue B concentrations within an optimum range by regulating transport processes. Boron transport was long believed to be a passive, unregulated process, but the identification of B transporters has suggested that plants sense and respond to the B conditions and regulate transporters to maintain B homeostasis. Scope Transporters responsible for efficient B uptake by roots, xylem loading and B distribution among leaves have been described. These transporters are required under B limitation for efficient acquisition and utilization of B. Transporters important for tolerating high B levels in the environment have also been identified, and these transporters export B from roots back to the soil. Two types of transporters are involved in these processes: NIPs (nodulin-26-like intrinsic proteins), boric acid channels, and BORs, B exporters. It is demonstrated that the expression of genes encoding these transporters is finely regulated in response to B availability in the environment to ensure tissue B homeostasis. Furthermore, plants tolerant to stress produced by low B or high B in the environment can be generated through altered expression of these transporters. Conclusions The identification of the first B transporter led to the discovery that B transport was a process mediated not only by passive diffusion but also by transporters whose activity was regulated in response to B conditions. Now it is evident that plants sense internal and external B conditions and regulate B transport by modulating the expression and/or accumulation of these transporters. Results obtained in model plants are applicable to other plant species, and such knowledge may be useful in designing plants or crops tolerant to soils containing low or high B. PMID:20228086

Further analysis and evaluation of the results of the NATO common shield-DAT#7 experiment: defence against terrorism

NASA Astrophysics Data System (ADS)

Dill, Stephan; Peichl, Markus; Jirousek, Matthias; Süß, Helmut

2009-09-01

The contactless control of persons and the remote surveillance of sensitive infrastructures are important tasks in order to provide the required security measures to protect the human population against the threads of international terrorism. Passive microwave imaging allows a daytime independent observation and examination of objects and persons under nearly all adverse ambient conditions without artificial exposure, hence fully avoiding health risks. The penetration capability of microwaves provides the detection of objects through atmospheric obstacles like bad weather, fog or dust, vapour and smoke, as well as through thin non-metallic materials and clothing. For the latter the detection of hidden objects like weapons, explosives, and contraband is possible by monitoring dielectric anomalies. The experiment "Common Shield" is part of a perennial investigation series leaded by the "Center for Transformation of the German armed forces (Bundeswehr)". In 2008 the protection of soldiers and facilities was experimentally investigated under the aspect of a networked operational leadership. In this context as well a harbour protection trial was carried out in August/September 2008 at the naval base Eckernfoerde in Germany. This trial was part of the NATO CNADs program of work for "Defence Against Terrorism (DAT)" starting in 2003, and Germany is the lead nation for item 7 on "Technology for Intelligence, Surveillance, Reconnaissance & Target Acquisition of Terrorists (ISRTA)". One main activity in the Eckernfoerde trial was the simulation of a military entrance control facility by a tent including various imaging and a chemical sensor suite in order to provide security for a military camp. Besides commercial optical and infrared cameras various passive millimeter-wave imagers have been used from different German research institutions. The DLR Microwaves and Radar Institute, Department for Reconnaissance and Security (HR-AS), provided an imaging radiometer scanner operating at W band. A multitude of situations have been simulated and many persons carrying hidden objects under their clothing have been scanned. The ongoing evaluation of the radiometer measurements are shown and discussed in the paper.

[Learning to solve a spatial task in a water maze in aggressive and submissive mice].

PubMed

Dubrovina, N I; Tomilenko, R A

2007-01-01

Learning and retention of the spatial memory were studied in mice with alternative under conditions of various experimental protocols. Visible and hidden platform acquisition in a simple model of the water maze was similarly fast both in aggressive and submissive mice, but extinction differed. Retention of the platform location preference persisted in aggressive mice in four testing trials. In submissive mice, extiction of the spatial memory was accompanied with a prolongation of search with parallel production of episodes of "passive drift". Differences in spatial learning between aggressive and submissive mice were revealed in a water maze complicated with partitions. In this case, aggressors were able to learn the position of a hidden platform (in contrast to submissive mice with the dominant response of "passive drift"). During testing the response, aggressive mice longer retained the spatial preference without extinction.

Centaur Propellant Thermal Conditioning Study

NASA Technical Reports Server (NTRS)

Blatt, M. H.; Pleasant, R. L.; Erickson, R. C.

1976-01-01

A wicking investigation revealed that passive thermal conditioning was feasible and provided considerable weight advantage over active systems using throttled vent fluid in a Centaur D-1s launch vehicle. Experimental wicking correlations were obtained using empirical revisions to the analytical flow model. Thermal subcoolers were evaluated parametrically as a function of tank pressure and NPSP. Results showed that the RL10 category I engine was the best candidate for boost pump replacement and the option showing the lowest weight penalty employed passively cooled acquisition devices, thermal subcoolers, dry ducts between burns and pumping of subcooler coolant back into the tank. A mixing correlation was identified for sizing the thermodynamic vent system mixer. Worst case mixing requirements were determined by surveying Centaur D-1T, D-1S, IUS, and space tug vehicles. Vent system sizing was based upon worst case requirements. Thermodynamic vent system/mixer weights were determined for each vehicle.

Robotic Arm Manipulator Using Active Control for Sample Acquisition and Transfer, and Passive Mode for Surface Compliance

NASA Technical Reports Server (NTRS)

Liu, Jun; Underhill, Michael L.; Trease, Brian P.; Lindemann, Randel A.

2010-01-01

A robotic arm that consists of three joints with four degrees of freedom (DOF) has been developed. It can carry an end-effector to acquire and transfer samples by using active control and comply with surface topology in a passive mode during a brief surface contact. The three joints are arranged in such a way that one joint of two DOFs is located at the shoulder, one joint of one DOF is located at the elbow, and one joint of one DOF is located at the wrist. Operationally, three DOFs are moved in the same plane, and the remaining one on the shoulder is moved perpendicular to the other three for better compliance with ground surface and more flexibility of sample handling. Three out of four joints are backdriveable, making the mechanism less complex and more cost effective

Passive water collection with the integument: mechanisms and their biomimetic potential.

PubMed

Comanns, Philipp

2018-05-22

Several mechanisms of water acquisition have evolved in animals living in arid habitats to cope with limited water supply. They enable access to water sources such as rain, dew, thermally facilitated condensation on the skin, fog, or moisture from a damp substrate. This Review describes how a significant number of animals - in excess of 39 species from 24 genera - have acquired the ability to passively collect water with their integument. This ability results from chemical and structural properties of the integument, which, in each species, facilitate one or more of six basic mechanisms: increased surface wettability, increased spreading area, transport of water over relatively large distances, accumulation and storage of collected water, condensation, and utilization of gravity. Details are described for each basic mechanism. The potential for bio-inspired improvement of technical applications has been demonstrated in many cases, in particular for several wetting phenomena, fog collection and passive, directional transport of liquids. Also considered here are potential applications in the fields of water supply, lubrication, heat exchangers, microfluidics and hygiene products. These present opportunities for innovations, not only in product functionality, but also for fabrication processes, where resources and environmental impact can be reduced. © 2018. Published by The Company of Biologists Ltd.

Power cavitation-guided blood-brain barrier opening with focused ultrasound and microbubbles

NASA Astrophysics Data System (ADS)

Burgess, M. T.; Apostolakis, I.; Konofagou, E. E.

2018-03-01

Image-guided monitoring of microbubble-based focused ultrasound (FUS) therapies relies on the accurate localization of FUS-stimulated microbubble activity (i.e. acoustic cavitation). Passive cavitation imaging with ultrasound arrays can achieve this, but with insufficient spatial resolution. In this study, we address this limitation and perform high-resolution monitoring of acoustic cavitation-mediated blood-brain barrier (BBB) opening with a new technique called power cavitation imaging. By synchronizing the FUS transmit and passive receive acquisition, high-resolution passive cavitation imaging was achieved by using delay and sum beamforming with absolute time delays. Since the axial image resolution is now dependent on the duration of the received acoustic cavitation emission, short pulses of FUS were used to limit its duration. Image sets were acquired at high-frame rates for calculation of power cavitation images analogous to power Doppler imaging. Power cavitation imaging displays the mean intensity of acoustic cavitation over time and was correlated with areas of acoustic cavitation-induced BBB opening. Power cavitation-guided BBB opening with FUS could constitute a standalone system that may not require MRI guidance during the procedure. The same technique can be used for other acoustic cavitation-based FUS therapies, for both safety and guidance.

Power cavitation-guided blood-brain barrier opening with focused ultrasound and microbubbles.

PubMed

Burgess, M T; Apostolakis, I; Konofagou, E E

2018-03-15

Image-guided monitoring of microbubble-based focused ultrasound (FUS) therapies relies on the accurate localization of FUS-stimulated microbubble activity (i.e. acoustic cavitation). Passive cavitation imaging with ultrasound arrays can achieve this, but with insufficient spatial resolution. In this study, we address this limitation and perform high-resolution monitoring of acoustic cavitation-mediated blood-brain barrier (BBB) opening with a new technique called power cavitation imaging. By synchronizing the FUS transmit and passive receive acquisition, high-resolution passive cavitation imaging was achieved by using delay and sum beamforming with absolute time delays. Since the axial image resolution is now dependent on the duration of the received acoustic cavitation emission, short pulses of FUS were used to limit its duration. Image sets were acquired at high-frame rates for calculation of power cavitation images analogous to power Doppler imaging. Power cavitation imaging displays the mean intensity of acoustic cavitation over time and was correlated with areas of acoustic cavitation-induced BBB opening. Power cavitation-guided BBB opening with FUS could constitute a standalone system that may not require MRI guidance during the procedure. The same technique can be used for other acoustic cavitation-based FUS therapies, for both safety and guidance.

Competition for nitrogen between Fagus sylvatica and Acer pseudoplatanus seedlings depends on soil nitrogen availability.

PubMed

Li, Xiuyuan; Rennenberg, Heinz; Simon, Judy

2015-01-01

Competition for nitrogen (N), particularly in resource-limited habitats, might be avoided by different N acquisition strategies of plants. In our study, we investigated whether slow-growing European beech and fast-growing sycamore maple seedlings avoid competition for growth-limiting N by different N uptake patterns and the potential alteration by soil N availability in a microcosm experiment. We quantified growth and biomass indices, (15)N uptake capacity and N pools in the fine roots. Overall, growth indices, N acquisition and N pools in the fine roots were influenced by species-specific competition depending on soil N availability. With inter-specific competition, growth of sycamore maple reduced regardless of soil N supply, whereas beech only showed reduced growth when N was limited. Both species responded to inter-specific competition by alteration of N pools in the fine roots; however, sycamore maple showed a stronger response compared to beech for almost all N pools in roots, except for structural N at low soil N availability. Beech generally preferred organic N acquisition while sycamore maple took up more inorganic N. Furthermore, with inter-specific competition, beech had an enhanced organic N uptake capacity, while in sycamore maple inorganic N uptake capacity was impaired by the presence of beech. Although sycamore maple could tolerate the suboptimal conditions at the cost of reduced growth, our study indicates its reduced competitive ability for N compared to beech.

Loganin enhances long-term potentiation and recovers scopolamine-induced learning and memory impairments.

PubMed

Hwang, Eun-Sang; Kim, Hyun-Bum; Lee, Seok; Kim, Min-Ji; Lee, Sung-Ok; Han, Seung-Moo; Maeng, Sungho; Park, Ji-Ho

2017-03-15

Although the incidence rate of dementia is rapidly growing in the aged population, therapeutic and preventive reagents are still suboptimal. Various model systems are used for the development of such reagents in which scopolamine is one of the favorable pharmacological tools widely applied. Loganin is a major iridoid glycoside obtained from Corni fructus (Cornusofficinalis et Zucc) and demonstrated to have anti-inflammatory, anti-tumor and osteoporosis prevention effects. It has also been found to attenuate Aβ-induced inflammatory reactions and ameliorate memory deficits induced by scopolamine. However, there has been limited information available on how loganin affects learning and memory both electrophysiologically and behaviorally. To assess its effect on learning and memory, we investigated the influence of acute loganin administration on long-term potentiation (LTP) using organotypic cultured hippocampal tissues. In addition, we measured the effects of loganin on the behavior performance related to avoidance memory, short-term spatial navigation memory and long-term spatial learning and memory in the passive avoidance, Y-maze, and Morris water maze learning paradigms, respectively. Loganin dose-dependently increased the total activity of fEPSP after high frequency stimulation and attenuated scopolamine-induced blockade of fEPSP in the hippocampal CA1 area. In accordance with these findings, loganin behaviorally attenuated scopolamine-induced shortening of step-through latency in the passive avoidance test, reduced the percent alternation in the Y-maze, and increased memory retention in the Morris water maze test. These results indicate that loganin can effectively block cholinergic muscarinic receptor blockade -induced deterioration of LTP and memory related behavioral performance. Based on these findings, loganin may aid in the prevention and treatment of Alzheimer's disease and learning and memory-deficit disorders in the future. Copyright © 2017 Elsevier Inc. All rights reserved.

Repeated administration of fresh garlic increases memory retention in rats.

PubMed

Haider, Saida; Naz, Nosheen; Khaliq, Saima; Perveen, Tahira; Haleem, Darakhshan J

2008-12-01

Garlic (Allium sativum) is regarded as both a food and a medicinal herb. Increasing attention has focused on the biological functions and health benefits of garlic as a potentially major dietary component. Chronic garlic administration has been shown to enhance memory function. Evidence also shows that garlic administration in rats affects brain serotonin (5-hydroxytryptamine [5-HT]) levels. 5-HT, a neurotransmitter involved in a number of physiological functions, is also known to enhance cognitive performance. The present study was designed to investigate the probable neurochemical mechanism responsible for the enhancement of memory following garlic administration. Sixteen adult locally bred male albino Wistar rats were divided into control (n = 8) and test (n = 8) groups. The test group was orally administered 250 mg/kg fresh garlic homogenate (FGH), while control animals received an equal amount of water daily for 21 days. Estimation of plasma free and total tryptophan (TRP) and whole brain TRP, 5-HT, and 5-hydroxyindole acetic acid (5-HIAA) was determined by high-performance liquid chromatography with electrochemical detection. For assessment of memory, a step-through passive avoidance paradigm (electric shock avoidance) was used. The results showed that the levels of plasma free TRP significantly increased (P < .01) and plasma total TRP significantly decreased (P < .01) in garlic-treated rats. Brain TRP, 5-HT, and 5-HIAA levels were also significantly increased following garlic administration. A significant improvement in memory function was exhibited by garlic-treated rats in the passive avoidance test. Increased brain 5-HT levels were associated with improved cognitive performance. The present results, therefore, demonstrate that the memory-enhancing effect of garlic may be associated with increased brain 5-HT metabolism in rats. The results further support the use of garlic as a food supplement for the enhancement of memory.

Developmental Subchronic Exposure to Diphenylarsinic Acid Induced Increased Exploratory Behavior, Impaired Learning Behavior, and Decreased Cerebellar Glutathione Concentration in Rats

PubMed Central

Negishi, Takayuki; Matsunaga, Yuki

2013-01-01

In Japan, people using water from the well contaminated with high-level arsenic developed neurological, mostly cerebellar, symptoms, where diphenylarsinic acid (DPAA) was a major compound. Here, we investigated the adverse effects of developmental exposure to 20mg/l DPAA in drinking water (early period [0–6 weeks of age] and/or late period [7–12]) on behavior and cerebellar development in male rats. In the open field test at 6 weeks of age, early exposure to DPAA significantly increased exploratory behaviors. At 12 weeks of age, late exposure to DPAA similarly increased exploratory behavior independent of the early exposure although a 6-week recovery from DPAA could reverse that change. In the passive avoidance test at 6 weeks of age, early exposure to DPAA significantly decreased the avoidance performance. Even at 12 weeks of age, early exposure to DPAA significantly decreased the test performance, which was independent of the late exposure to DPAA. These results suggest that the DPAA-induced increase in exploratory behavior is transient, whereas the DPAA-induced impairment of passive avoidance is long lasting. At 6 weeks of age, early exposure to DPAA significantly reduced the concentration of cerebellar total glutathione. At 12 weeks of age, late, but not early, exposure to DPAA also significantly reduced the concentration of cerebellar glutathione, which might be a primary cause of oxidative stress. Early exposure to DPAA induced late-onset suppressed expression of NMDAR1 and PSD95 protein at 12 weeks of age, indicating impaired glutamatergic system in the cerebellum of rats developmentally exposed to DPAA. PMID:24008832

Age differences in emotion regulation effort: Pupil response distinguishes reappraisal and distraction for older but not younger adults.

PubMed

Martins, Bruna; Florjanczyk, Jan; Jackson, Nicholas J; Gatz, Margaret; Mather, Mara

2018-03-01

In previous research, older adults show greater emotional benefits from distracting themselves than from reappraising an event when strategically regulating emotion. Older adults also demonstrate an attentional preference to avoid, while younger adults show a bias toward approaching negative stimuli. This suggests a possible age-related differentiation of cognitive effort across approach and avoidance of negative stimuli during emotion regulation. In this study, we tracked cognitive effort via pupil dilation during the use of distraction (avoidance) and reappraisal (approach) strategies across age. Forty-eight younger adults (M = 20.94, SD = 1.78; 19 men) and 48 older adults (M = 68.82, SD = 5.40; 15 men) viewed a slideshow of negative images and were instructed to distract, reappraise, or passively view each image. Older adults showed greater pupil dilation during reappraisal than distraction, but younger adults displayed no difference between conditions-an effect that survived when controlling for gaze patterns. Gaze findings revealed that older adults looked less within images during active emotion regulation compared with passive viewing (no difference between distraction and reappraisal), and younger adults showed no difference across strategies. Younger adults gazed less within the most emotional image areas during distraction, but this did not significantly contribute to pupil response. Our findings support that distraction is less cognitively effortful than reinterpreting negative information in later life. These findings could be explained by older adults' motivational bias to disengage from negative information because of the age-related positivity effect, or compensation for decreased working memory resources across the life span. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Acquisition of Uropygial Gland Microbiome by Hoopoe Nestlings.

PubMed

Martín-Vivaldi, Manuel; Soler, Juan José; Martínez-García, Ángela; Arco, Laura; Juárez-García-Pelayo, Natalia; Ruiz-Rodríguez, Magdalena; Martínez-Bueno, Manuel

2017-12-18

Mutualistic symbioses between animals and bacteria depend on acquisition of appropriate symbionts while avoiding exploitation by non-beneficial microbes. The mode of acquisition of symbionts would determine, not only the probability of encountering but also evolutionary outcomes of mutualistic counterparts. The microbiome inhabiting the uropygial gland of the European hoopoe (Upupa epops) includes a variety of bacterial strains, some of them providing antimicrobial benefits. Here, the mode of acquisition and stability of this microbiome is analyzed by means of Automated rRNA Intergenic Spacer Analysis and two different experiments. The first experiment impeded mothers' access to their glands, thus avoiding direct transmission of microorganisms from female to offspring secretions. The second experiment explored the stability of the microbiomes by inoculating glands with secretions from alien nests. The first experiment provoked a reduction in similarity of microbiomes of mother and nestlings. Interestingly, some bacterial strains were more often detected when females had not access to their glands, suggesting antagonistic effects among bacteria from different sources. The second experiment caused an increase in richness of the microbiome of receivers in terms of prevalence of Operational Taxonomic Units (OTUs) that reduced differences in microbiomes of donors and receivers. That occurred because OTUs that were present in donors but not in receivers incorporated to the microbiome of the latter, which provoked that cross-inoculated nestlings got similar final microbiomes that included the most prevalent OTUs. The results are therefore consistent with a central role of vertical transmission in bacterial acquisition by nestling hoopoes and support the idea that the typical composition of the hoopoe gland microbiome is reached by the incorporation of some bacteria during the nestling period. This scenario suggests the existence of a coevolved core microbiome composed by a mix of specialized vertically transmitted strains and facultative symbionts able to coexist with them. The implications of this mixed mode of transmission for the evolution of the mutualism are discussed.

Punishment and the potential for negative reinforcement with histamine injection.

PubMed

Mayer, Paulo César Morales; de Carvalho Neto, Marcus Bentes; Katz, Jonathan L

2018-03-01

The present study examined punishment of responding with histamine injection, and its potential to generate avoidance of punishment. Sprague-Dawley rats were trained under concurrent schedules in which responses on one lever (the punishment lever) produced food under a variable-interval schedule, and under some conditions intermittent injections of histamine, which suppressed behavior. Responses on a second (avoidance) lever prevented histamine injections scheduled on the punishment lever. After stabilization of punished responding, a variable-interval 15-s schedule of cancellation of histamine (avoidance) was added for responding on the second/avoidance lever, without subsequent acquisition of responding on that lever. Progressive decreases in the length of the punishment variable-interval schedule increased suppression on the punishment lever without increases in response rates on the avoidance lever. Exchanging contingencies on the levers ensured that response rates on the avoidance lever were sufficiently high to decrease the histamine injection frequency; nonetheless response rates on the avoidance lever decreased over subsequent sessions. Under no condition was responding maintained on the avoidance lever despite continued punishing effectiveness of histamine throughout. The present results suggest that avoidance conditioning is not a necessary condition for effective punishment, and confirm the importance of empirical rather than presumed categorization of behavioral effects of stimulus events. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

Enhancing Classroom Participation of Rural Trainee Teachers of English through Use of Action Research: A Reflecton from a Chinese Teacher Trainer's Perspective

ERIC Educational Resources Information Center

Ping, Wang

2015-01-01

A common problem for Chinese teacher trainers is coping with a passive class with silent trainee learners, when trainees tend to be unresponsive and avoid interactions with the trainer. This is especially true when a trainer seeks interactions in the process of training, such as asking questions to the class as a whole or expecting at least one…

Moral fixations: The role of moral integrity and social anxiety in the selective avoidance of social threat.

PubMed

Van Dillen, Lotte F; Enter, Dorien; Peters, Leonie P M; van Dijk, Wilco W; Rotteveel, Mark

2017-01-01

People derive their sense of belonging from perceptions of being a moral person. Research moreover suggests that social cues of rejection rapidly influence visual scanning, and result in avoidant gaze behavior, especially in socially anxious individuals. With the current eye-tracking experiment, we therefore examined whether moral integrity threats and affirmations influence selective avoidance of social threat, and how this varies with individual differences in social anxiety. Fifty-nine participants retrieved a memory of a past immoral, moral, or neutral act. Next, participants passively viewed angry, happy, and neutral faces, while we recorded how often they first fixated on the eyes. In addition, we administered the Liebowitz Social Anxiety Scale (1987). Participants first fixated less on angry eyes compared to happy or neutral eyes when their moral integrity was threatened, and this selective avoidance was enhanced with increasing social anxiety. Following a moral affirmation, however, participants no longer selectively avoided the eyes of angry faces, regardless of individual differences in social anxiety. The results thus suggest that both low and high socially anxious people adjust their social gaze behavior in response to threats and affirmations of their moral integrity, pointing to the importance of the social context when considering affective processing biases. Copyright © 2016 Elsevier B.V. All rights reserved.

Intercepted signals for ionospheric science

NASA Astrophysics Data System (ADS)

Lind, F. D.; Erickson, P. J.; Coster, A. J.; Foster, J. C.; Marchese, J. R.; Berkowitz, Z.; Sahr, J. D.

2013-05-01

The ISIS array (Intercepted Signals for Ionospheric Science) is a distributed, coherent software radio array designed for the study of geospace phenomena by observing the scatter of ambient radio frequency (RF) signals. ISIS data acquisition and analysis is performed using the MIDAS-M platform (Millstone Data Acquisition System - Mobile). Observations of RF signals can be performed between HF and L-band using the Array nodes and appropriate antennas. The deployment of the Array focuses on observations of the plasmasphere boundary layer. We discuss the concept of the coherent software radio array, describe the ISIS hardware, and give examples of data from the system for selected applications. In particular, we include the first observations of E region irregularities using the Array. We also present single-site passive radar observations of both meteor trails and E region irregularities using adaptive filtering techniques.

Implications of the Naturalistic Decision Making Framework for Information Dominance.

DTIC Science & Technology

1997-07-01

Information Dominance , defined as an operational advantage obtained through superior effectiveness of informational activity. NDM is the study of how people use their experience to make decisions in field settings. Expertise was considered at both the individual and the team level of decision making. The report defines the components of expertise and identifies obstacles to the acquisition of Information Dominance . These obstacles include: (1) excessive data, (2) pre-processed data, (3) excessive procedures, (4) performing formal analyses, (5) passive

Experimental and Analytical Investigation of the Vibration Characteristics of a Remotely Piloted Helicopter

DTIC Science & Technology

1992-06-01

IQ Z -104.9* 171: .0471 6/LB XP11 ) EXP N I SETUP W TF DUAL v, 400 CHAB FR 200HZ 0:30:to * /A AIS ’"TS.H A S 8 -IV ISO -10 •]’Ft B/A AY6 IL TEý . 2 " N C...4 A. SOURCES OF HELICOPTER VIBRATION .... ..... 4 B. VIBRATION REDUCTION TECHNIQUES ..... ...... 6 1. Passive Systems .......... ............ 6 2 ...EXCITATION SYSTEM ...... ............. 22 C. DATA ACQUISITION SYSTEM .... .......... 27 1. Components ......... .............. 27 2 . System Operation

A Near Term Approach to Embedded Training: Battle Command Visualization 101

DTIC Science & Technology

2006-05-01

Example of Task Guidance area at the end of Module 1, Exercise 1 (Level 1) ...... 26 Figure 9 Example of Robo -Scout information, accessed through the...unmanned ground vehicle (UGV) sensor, the Robo -Scout. They will be equipped with both passive and active systems to provide target acquisition, real...PIR# Track of Update RqieTemplated Required 1 Tracked & NAI 1, 2 S, T S200 synthetic L 2 hrs Vehicle type, Intel, Fires (PIR 1) Wheeled aperture radar

The National Shipbuilding Research Program. Update Handbook for Surface Preparation and Coatings in Tanks and Confined Areas

DTIC Science & Technology

2000-10-31

cleaning method are described in Naval Ships’ Technical Manual Chapter 631. 4.6.4 Citric Acid Cleaning The citric acid cleaning system is intended to...acquisition of necessary chemicals and tools, degreasing/cleaning, paint/stripping/removal, citric acid rust removal, passivation of bare steel, and drying...Figure 9-7 Hanging Explosion -Proof Light Box • Figure 9-8 Lighting in Tank • Figure 10-1 Hazardous Waste Storage Area • Figure 10-2 Solvent

The flying hot wire and related instrumentation

NASA Technical Reports Server (NTRS)

Coles, D.; Cantnell, B.; Wadcock, A.

1978-01-01

A flying hot-wire technique is proposed for studies of separated turbulent flow in wind tunnels. The technique avoids the problem of signal rectification in regions of high turbulence level by moving the probe rapidly through the flow on the end of a rotating arm. New problems which arise include control of effects of torque variation on rotor speed, avoidance of interference from the wake of the moving arms, and synchronization of data acquisition with rotation. Solutions for these problems are described. The self-calibrating feature of the technique is illustrated by a sample X-array calibration.

An Overview of NASA's In-Space Cryogenic Propellant Management Technologies

NASA Technical Reports Server (NTRS)

Tucker, Stephen; Hastings, Leon; Haynes, Davy (Technical Monitor)

2001-01-01

Future mission planning within NASA continues to include cryogenic propellants for in space transportation, with mission durations ranging from days to years. Between 1995 and the present, NASA has pursued a diversified program of ground-based testing to prepare the various technologies associated with in-space cryogenic fluid management (CFM) for implementation. CFM technology areas being addressed include passive insulation, zero gravity pressure control, zero gravity mass gauging, capillary liquid acquisition devices, and zero boiloff storage. NASA CFM technologies are planned, coordinated, and implemented through the Cryogenic Technology Working Group which is comprised of representatives from the various NASA Centers as well as the National Institute of Standards and Technologies (NIST) and, on selected occasions, the Air Force. An overview of the NASA program and Marshall Space Flight Center (MSFC) roles, accomplishments, and near-term activities are presented herein. Basic CFM technology areas being addressed include passive insulation, zero gravity pressure control, zero gravity mass gauging, capillary liquid acquisition devices, and zero boiloff storage. Recent MSFC accomplishments include: the large scale demonstration of a high performance variable density multilayer insulation (MLI) that reduced the boiloff by about half that of standard MLI; utilization of a foam substrate under MLI to eliminate the need for a helium purge bag system; demonstrations of both spray-bar and axial-jet mixer concepts for zero gravity pressure control; and sub-scale testing that verified an optical sensor concept for measuring liquid hydrogen mass in zero gravity. In response to missions requiring cryogenic propellant storage durations on the order of years, a cooperative effort by NASA's Ames Research Center, Glenn Research Center, and MSFC has been implemented to develop and demonstrate zero boiloff concepts for in-space storage of cryogenic propellants. An MSFC contribution to this cooperative effort is a large-scale demonstration of the integrated operation of passive insulation, destratification/pressure control, and cryocooler (commercial unit) subsystems to achieve zero boiloff storage of liquid hydrogen. Testing is expected during the Summer of 2001.

Preliminary Results on the Use of Leather Chrome Shavings for Air Passive Sampling

PubMed Central

Sanjuán-Herráez, D.; Chabaane, L.; Tahiri, S.; Pastor, A.; de la Guardia, M.

2012-01-01

A new passive sampler based on low-density polyethylene (LDPE) layflat tube filled with chrome shavings from tannery waste residues was evaluated to determine volatile organic compounds (VOCs) in indoor and outdoor areas. VOCs were directly determined by head space-gas chromatography-mass spectrometry (HS-GC-MS) without any pretreatment of the sampler and avoiding the use of solvents. Limit of detection values ranging from 20 to 75 ng sampler−1 and good repeatability values were obtained for VOCs under study with relative standard deviation values from 2.8 to 9.6% except for carbon disulfide for which it was 22.5%. The effect of the amount of chrome shavings per sampler was studied and results were compared with those obtained using empty LDPE tubes, to demonstrate the capacity of chrome shavings to adsorb VOCs. PMID:22900233

Advanced obstacle avoidance for a laser based wheelchair using optimised Bayesian neural networks.

PubMed

Trieu, Hoang T; Nguyen, Hung T; Willey, Keith

2008-01-01

In this paper we present an advanced method of obstacle avoidance for a laser based intelligent wheelchair using optimized Bayesian neural networks. Three neural networks are designed for three separate sub-tasks: passing through a door way, corridor and wall following and general obstacle avoidance. The accurate usable accessible space is determined by including the actual wheelchair dimensions in a real-time map used as inputs to each networks. Data acquisitions are performed separately to collect the patterns required for specified sub-tasks. Bayesian frame work is used to determine the optimal neural network structure in each case. Then these networks are trained under the supervision of Bayesian rule. Experiment results showed that compare to the VFH algorithm our neural networks navigated a smoother path following a near optimum trajectory.

Hazard avoidance via descent images for safe landing

NASA Astrophysics Data System (ADS)

Yan, Ruicheng; Cao, Zhiguo; Zhu, Lei; Fang, Zhiwen

2013-10-01

In planetary or lunar landing missions, hazard avoidance is critical for landing safety. Therefore, it is very important to correctly detect hazards and effectively find a safe landing area during the last stage of descent. In this paper, we propose a passive sensing based HDA (hazard detection and avoidance) approach via descent images to lower the landing risk. In hazard detection stage, a statistical probability model on the basis of the hazard similarity is adopted to evaluate the image and detect hazardous areas, so that a binary hazard image can be generated. Afterwards, a safety coefficient, which jointly utilized the proportion of hazards in the local region and the inside hazard distribution, is proposed to find potential regions with less hazards in the binary hazard image. By using the safety coefficient in a coarse-to-fine procedure and combining it with the local ISD (intensity standard deviation) measure, the safe landing area is determined. The algorithm is evaluated and verified with many simulated descent downward looking images rendered from lunar orbital satellite images.

Agglutination by anti-capsular polysaccharide antibody is associated with protection against experimental human pneumococcal carriage

PubMed Central

Reiné, J; Zangari, T; Owugha, JT; Pennington, SH; Gritzfeld, JF; Wright, AD; Collins, AM; van Selm, S; de Jonge, MI; Gordon, SB; Weiser, JN; Ferreira, DM

2016-01-01

The ability of pneumococcal conjugate vaccine (PCV) to decrease transmission by blocking the acquisition of colonization has been attributed to herd immunity. We describe the role of mucosal IgG to capsular polysaccharide (CPS) in mediating protection from carriage, translating our findings from a murine model to humans. We used a flow-cytometric assay to quantify antibody-mediated agglutination demonstrating that hyperimmune sera generated against an unencapsulated mutant was poorly agglutinating. Passive immunization with this antiserum was ineffective to block acquisition of colonization compared to agglutinating antisera raised against the encapsulated parent strain. In the human challenge model samples were collected from PCV and control vaccinated adults. In PCV-vaccinated subjects IgG levels to CPS were increased in serum and nasal wash (NW). IgG to the inoculated strain CPS dropped in NW samples after inoculation suggesting its sequestration by colonizing pneumococci. In post-vaccination NW samples pneumococci were heavily agglutinated compared to pre-vaccination samples in subjects protected against carriage. Our results indicate that pneumococcal agglutination mediated by CPS specific antibodies is a key mechanism of protection against acquisition of carriage. Capsule may be the only vaccine target that can elicit strong agglutinating antibody responses, leading to protection against carriage acquisition and generation of herd immunity. PMID:27579859

APNEA list mode data acquisition and real-time event processing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hogle, R.A.; Miller, P.; Bramblett, R.L.

1997-11-01

The LMSC Active Passive Neutron Examinations and Assay (APNEA) Data Logger is a VME-based data acquisition system using commercial-off-the-shelf hardware with the application-specific software. It receives TTL inputs from eighty-eight {sup 3}He detector tubes and eight timing signals. Two data sets are generated concurrently for each acquisition session: (1) List Mode recording of all detector and timing signals, timestamped to 3 microsecond resolution; (2) Event Accumulations generated in real-time by counting events into short (tens of microseconds) and long (seconds) time bins following repetitive triggers. List Mode data sets can be post-processed to: (1) determine the optimum time bins formore » TRU assay of waste drums, (2) analyze a given data set in several ways to match different assay requirements and conditions and (3) confirm assay results by examining details of the raw data. Data Logger events are processed and timestamped by an array of 15 TMS320C40 DSPs and delivered to an embedded controller (PowerPC604) for interim disk storage. Three acquisition modes, corresponding to different trigger sources are provided. A standard network interface to a remote host system (Windows NT or SunOS) provides for system control, status, and transfer of previously acquired data. 6 figs.« less

Feasibility of developing a portable driver performance data acquisition system for human factors research: Technical tasks. Volume 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carter, R.J.; Barickman, F.S.; Spelt, P.F.

1998-01-01

A two-phase, multi-year research program entitled ``development of a portable driver performance data acquisition system for human factors research`` was recently completed. The primary objective of the project was to develop a portable data acquisition system for crash avoidance research (DASCAR) that will allow drive performance data to be collected using a large variety of vehicle types and that would be capable of being installed on a given vehicle type within a relatively short-time frame. During phase 1 a feasibility study for designing and fabricating DASCAR was conducted. In phase 2 of the research DASCAR was actually developed and validated.more » This technical memorandum documents the results from the feasibility study. It is subdivided into three volumes. Volume one (this report) addresses the last five items in the phase 1 research and the first issue in the second phase of the project. Volumes two and three present the related appendices, and the design specifications developed for DASCAR respectively. The six tasks were oriented toward: identifying parameters and measures; identifying analysis tools and methods; identifying measurement techniques and state-of-the-art hardware and software; developing design requirements and specifications; determining the cost of one or more copies of the proposed data acquisition system; and designing a development plan and constructing DASCAR. This report also covers: the background to the program; the requirements for the project; micro camera testing; heat load calculations for the DASCAR instrumentation package in automobile trunks; phase 2 of the research; the DASCAR hardware and software delivered to the National Highway Traffic Safety Administration; and crash avoidance problems that can be addressed by DASCAR.« less

Passivation of bimetallic catalysts used in water treatment: prevention and reactivation.

PubMed

Chen, Jianming; Gillham, Robert W; Gui, Lai

2013-01-01

With respect to degradation rates and the range in contaminants treated, bimetals such as Ni-Fe or Pd-Fe generally outperform unamended granular iron. However, the catalytic enhancement is generally short-lived, lasting from a few days to months. To take advantage of the significant benefits of bimetals, this study aims at developing an effective method for the rejuvenation of passivated bimetals and alternatively, the prevention of rapid reactivity loss of bimetals. Because the most likely cause of Ni-Fe and Pd-Fe passivation is the deposition of iron oxide films over the catalyst sites, it is hypothesized that removal of the iron oxide films will restore the lost reactivity or avoiding the deposition of iron oxide films will prevent passivation. Two organic ligands (ethylenediaminetetraacetic acid (EDTA), and [s,s]-ethylenediaminedisuccinate acid ([s,s]-EDDS)) and two acids (citric acid and sulphuric acid) were tested as possible chemical reagents for both passivation rejuvenation and prevention. Trichloroethene (TCE) and Ni-Fe were chosen as probes for chlorinated solvents and bimetals respectively. The test was carried out using small glass columns packed with Ni-Fe. TCE solution containing a single reagent at various concentrations was pumped through the Ni-Fe columns with a residence time in the Ni-Fe of about 6.6 min. TCE concentrations in the influent and effluent were measured to evaluate the performance of each chemical reagent. The results show that (i) for passivated Ni-Fe, flushing with a low concentration of acid or ligand solution without mechanical mixing can fully restore the lost reactivity; and (ii) for passivation prevention, adding a small amount of a ligand or an acid to the feed solution can successfully prevent or at least substantially reduce Ni-Fe passivation. All four chemicals tested are effective in both rejuvenation and prevention, but sulphuric acid and citric acid are considered to be the most practical reagents due to their relatively low costs and environmentally friendly nature. This study suggests that the use of bimetals in above-groundwater treatment applications could become practical with appropriate engineering design.

Wetland-based passive treatment systems for gold ore processing effluents containing residual cyanide, metals and nitrogen species.

PubMed

Alvarez, R; Ordóñez, A; Loredo, J; Younger, P L

2013-10-01

Gold extraction operations generate a variety of wastes requiring responsible disposal in compliance with current environmental regulations. During recent decades, increased emphasis has been placed on effluent control and treatment, in order to avoid the threat to the environment posed by toxic constituents. In many modern gold mining and ore processing operations, cyanide species are of most immediate concern. Given that natural degradation processes are known to reduce the toxicity of cyanide over time, trials have been made at laboratory and field scales into the feasibility of using wetland-based passive systems as low-cost and environmentally friendly methods for long-term treatment of leachates from closed gold mine tailing disposal facilities. Laboratory experiments on discrete aerobic and anaerobic treatment units supported the development of design parameters for the construction of a field-scale passive system at a gold mine site in northern Spain. An in situ pilot-scale wetland treatment system was designed, constructed and monitored over a nine-month period. Overall, the results suggest that compost-based constructed wetlands are capable of detoxifying cyanidation effluents, removing about 21.6% of dissolved cyanide and 98% of Cu, as well as nitrite and nitrate. Wetland-based passive systems can therefore be considered as a viable technology for removal of residual concentrations of cyanide from leachates emanating from closed gold mine tailing disposal facilities.

Greater avoidance behavior in individuals with posttraumatic stress disorder symptoms

PubMed Central

Sheynin, Jony; Shind, Christine; Radell, Milen; Ebanks-Williams, Yasheca; Gilbertson, Mark W.; Beck, Kevin D.; Myers, Catherine E.

2017-01-01

While avoidance is a core symptom of PTSD, little is known about whether individuals with PTSD show a general cognitive bias to acquire and express avoidance, in situations not related to trauma or fear. Here, we used a computer-based task to examine operant acquisition and extinction of avoidance in participants with and without severe self -reported PTSD symptoms. A total of 119 participants (77 male, 42 female; 74 veteran, 45 civilian) with symptoms (PTSS; n=63) or with few/no symptoms (noPTSS; n=56) performed a task, in which they controlled a spaceship and could shoot a target to gain points or hide in “safe areas” to escape or avoid on-screen aversive events. Results show that participants with PTSS exhibited more avoidance across trials than no PTSS participants, particularly due to more avoidance behavior in PTSS females compared to noPTSS females. Avoidance behavior decreased across extinction trials but interactions with PTSS and gender fell short of significance. Overall, PTSD symptoms were associated with propensity to acquire and express avoidance behavior, in both civilians and veterans, and even in a cognitive task that does not explicitly involve trauma or fear. This effect was more pronounced in females, highlighting the role of gender differences in PTSD symptomatology. Importantly, this study also demonstrates the potential of an objective assessment of avoidance behavior, which could be used to supplement the common but limited self-report tools. PMID:28322068

Greater avoidance behavior in individuals with posttraumatic stress disorder symptoms.

PubMed

Sheynin, Jony; Shind, Christine; Radell, Milen; Ebanks-Williams, Yasheca; Gilbertson, Mark W; Beck, Kevin D; Myers, Catherine E

2017-05-01

While avoidance is a core symptom of PTSD, little is known about whether individuals with PTSD show a general cognitive bias to acquire and express avoidance, in situations not related to trauma or fear. Here, we used a computer-based task to examine operant acquisition and extinction of avoidance in participants with and without severe self-reported PTSD symptoms. A total of 119 participants (77 male, 42 female; 74 veteran, 45 civilian) with symptoms (PTSS; n = 63) or with few/no symptoms (noPTSS; n = 56) performed a task, in which they controlled a spaceship and could shoot a target to gain points or hide in "safe areas" to escape or avoid on-screen aversive events. Results show that participants with PTSS exhibited more avoidance across trials than noPTSS participants, particularly due to more avoidance behavior in PTSS females compared to noPTSS females. Avoidance behavior decreased across extinction trials but interactions with PTSS and gender fell short of significance. Overall, PTSD symptoms were associated with propensity to acquire and express avoidance behavior, in both civilians and veterans, and even in a cognitive task that does not explicitly involve trauma or fear. This effect was more pronounced in females, highlighting the role of gender differences in PTSD symptomatology. Importantly, this study also demonstrates the potential of an objective assessment of avoidance behavior, which could be used to supplement the common but limited self-report tools.

Culture in Foreign Language Teaching

ERIC Educational Resources Information Center

Kramsch, Claire

2013-01-01

In foreign language education, the teaching of culture remains a hotly debated issue. What is culture? What is its relation to language? Which and whose culture should be taught? What role should the learners' culture play in the acquisition of knowledge of the target culture? How can we avoid essentializing cultures and teaching stereotypes? And…

A Connectionist Model of the Retreat from Verb Argument Structure Overgeneralization

ERIC Educational Resources Information Center

Ambridge, Ben; Blything, Ryan P.

2016-01-01

A central question in language acquisition is how children build linguistic representations that allow them to generalize verbs from one construction to another (e.g., "The boy gave a present to the girl" ? "The boy gave the girl a present"), whilst appropriately constraining those generalizations to avoid non-adultlike errors…

Cognitive Load Theory and the Acquisition of Complex Cognitive Skills in the Elderly: Towards an Integrative Framework.

ERIC Educational Resources Information Center

Van Gerven, Pascal W. M.; Paas, Fred G. W. C.; Van Merrienboer, Jeroen J. G.; Schmidt, Henk G.

2000-01-01

Cognitive load (CL) theory suggests minimizing extraneous CL and maximizing germane CL in order not to overload working memory. Instructional design for older adults should therefore include goal-free problems, worked examples, and different modalities and avoid splitting attention and including redundant information. (SK)

How To Avoid Acquisition Disasters and Create Affordable Solutions for America’s Air Warriors by Applying Lessons from the Past

DTIC Science & Technology

2011-02-16

Strike Fighter Program. Research Report, Air Command and Staff College, Air University, Montgomery: Air University, 2008. Boyne, Walter J. Messerschmitt...Restructures Program. Testimony, Washington, D.C.: General Accounting Office, 2010. Gillcrist, Paul T. Tomcat: The Grumman F-14 Story. Atglen: Schiffer

Facilitation by 8-OH-DPAT of passive avoidance performance in rats after inactivation of 5-HT1A receptors

PubMed Central

Otano, Ana; García-Osta, Ana; Ballaz, Santiago; Frechilla, Diana; Del Río, Joaquín

1999-01-01

Pretraining administration of 8-hydroxy-2-di-n-propylamino-tetralin (8-OH-DPAT 0.1 mg kg−1), a 5-HT1A receptor agonist, or buspirone (1 mg kg−1), a 5-HT1A receptor partial agonist, markedly impaired passive avoidance retention in rats 24 h later. The effect of 8-OH-DPAT was prevented by the 5-HT1A receptor antagonists, NAN-190 and WAY-100635, at doses without any intrinsic effect.N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ 10 mg kg−1), an alkylating agent that inactivates different G-protein coupled receptors, impaired retention performance when given 48 h pretraining. The disruptive effect of EEDQ was reversed by 8-OH-DPAT or buspirone, given 30 min before training.Non-specific actions did not account for 8-OH-DPAT-induced reversal of the EEDQ effect since no significant difference in locomotor activity or in pain threshold was found between rats receiving EEDQ or EEDQ+8-OH-DPAT.When NAN-190 (1 mg kg−1) or WAY-100635 (0.5 mg kg−1) were given before 8-OH-DPAT to EEDQ-pretreated animals, the reversal by 8-OH-DPAT of EEDQ-induced retention impairment was still more pronounced. However, no EEDQ reversal by 8-OH-DPAT was found when 5-HT1A receptors were protected by WAY-100635 (10 mg kg−1) 30 min before EEDQ.In the hippocampus of EEDQ-treated rats, 5-HT7 receptors were less inactivated than 5-HT1A receptors and significant increases were found in 5-HT1A but not in 5-HT7 receptor mRNA levels. Ritanserin and methiothepin (10 mg kg−1 each), antagonists with higher affinity at 5-HT7 than at 5-HT1A receptors, prevented the retention impairment induced by EEDQ but did not significantly protect against 5-HT7 receptor inactivation.The results indicate that the facilitatory effect of 8-OH-DPAT is not mediated through 5-HT1A receptors and suggest that other 8-OH-DPAT-sensitive receptors could be involved in the dual effect of 8-OH-DPAT on passive avoidance performance in rats. PMID:10588924

Behavioral methods for the study of the Ras-ERK pathway in memory formation and consolidation: passive avoidance and novel object recognition tests.

PubMed

d'Isa, Raffaele; Brambilla, Riccardo; Fasano, Stefania

2014-01-01

Memory is a high-level brain function that enables organisms to adapt their behavioral responses to the environment, hence increasing their probability of survival. The Ras-ERK pathway is a key molecular intracellular signalling cascade for memory consolidation. In this chapter we will describe two main one-trial behavioral tests commonly used in the field of memory research in order to assess the role of Ras-ERK signalling in long-term memory: passive avoidance and object recognition. Passive avoidance (PA) is a fear-motivated instrumental learning task, designed by Jarvik and Essman in 1960, in which animals learn to refrain from emitting a behavioral response that has previously been associated with a punishment. We will describe here the detailed protocol and show some examples of how PA can reveal impairments or enhancements in memory consolidation following loss or gain of function genetic manipulations of the Ras-ERK pathway. The phenotypes of global mutants as Ras-GRF1 KO, GENA53, and ERK1 KO mice, as well as of conditional region-specific mutants (striatal K-CREB mice), will be illustrated as examples. Novel object recognition (NOR), developed by Ennaceur and Delacour in 1988, is instead a more recent and highly ecological test, which relies on the natural tendency of rodents to spontaneously approach and explore novel objects, representing hence a useful non-stressful tool for the study of memory in animals without the employment of punishments or starvation/water restriction regimens. Careful indications will be given on how to select the positions for the novel object, in order to counterbalance for individual side preferences among mice during the training. Finally, the methods for calculating two learning indexes will be described. In addition to the classical discrimination index (DI) that measures the ability of an animal to discriminate between two different objects which are presented at the same time, we will describe the formula of a new index that we present here for the first time, the recognition index (RI), which quantifies the ability of an animal to recognize a same object at different time points and that, by taking into account the basal individual preferences displayed during the training, can give a more accurate measure of an animal's actual recognition memory.

Child abuse and performance task assessments of executive functions in boys.

PubMed

Mezzacappa, E; Kindlon, D; Earls, F

2001-11-01

We examined executive functions using performance tasks in 126 boys aged 6 to 16 years. who attended public schools and therapeutic schools for children with emotional and behavioral problems. Children were further grouped based on the presence or absence of substantiated abuse histories. Based on their abuse histories and schools of origin, children were classified as Therapeutic, Abused (TA, N = 25). Therapeutic, Nonabused (TN, N = 52), and Public School (PS, N = 48). Controlling IQ and medication status, we compared children in the three groups on teacher ratings of behavior, on experimenter observations of behavior during testing, and on performance tasks challenging the capacities to inhibit an act in progress, and to passively avoid responses associated with adverse consequences. We examined mean group differences in symptoms, behaviors, and task performance, as well as differential age-dependent changes in these dimensions. Independent of abuse history, therapeutic school children demonstrated comparable levels of internalizing and externalizing symptoms, and comparable levels of redirections to task during testing-sessions, that were significantly higher than those of the public school children. Both groups of therapeutic school children also showed comparable overall performance on the capacities to inhibit an act in progress, and to passively avoid responses associated with adverse consequences that were poorer than the performance of children from the public school. Children with histories of substantiated abuse showed diminished improvement with increasing age in the capacity to passively avoid responses associated with adverse consequences when compared not only to the public school children, but also to the children from the therapeutic schools without histories of abuse. Our findings complement reports of behavioral observations of abused children, and reports associating child abuse with altered cognitive development in other areas of competence. They suggest that child abuse may negatively influence the expected developmental progression of competence in certain executive functions. This in turn could have implications for the nature and the persistence of certain forms of psychopathology associated with abuse and poor self-control. Given the cross-sectional nature of our data, however, longitudinal developmental studies of the relations between child abuse and executive functions are needed to elucidate the influence of abuse on the growth and development of such organizing principles of behavioral self-regulation.

Strain Wave Acquisition by a Fiber Optic Coherent Sensor for Impact Monitoring

PubMed Central

Sbarufatti, Claudio; Beligni, Alessio; Gilioli, Andrea; Ferrario, Maddalena; Mattarei, Marco; Martinelli, Mario; Giglio, Marco

2017-01-01

A novel fiber optic sensing technology for high frequency dynamics detection is proposed in this paper, specifically tailored for structural health monitoring applications based on strain wave analysis, for both passive impact identification and active Lamb wave monitoring. The sensing solution relies on a fiber optic-based interferometric architecture associated to an innovative coherent detection scheme, which retrieves in a completely passive way the high-frequency phase information of the received optical signal. The sensing fiber can be arranged into different layouts, depending on the requirement of the specific application, in order to enhance the sensor sensitivity while still ensuring a limited gauge length if punctual measures are required. For active Lamb wave monitoring, this results in a sensing fiber arranged in multiple loops glued on an aluminum thin panel in order to increase the phase signal only in correspondence to the sensing points of interest. Instead, for passive impact identification, the required sensitivity is guaranteed by simply exploiting a longer gauge length glued to the structure. The fiber optic coherent (FOC) sensor is exploited to detect the strain waves emitted by a piezoelectric transducer placed on the aluminum panel or generated by an impulse hammer, respectively. The FOC sensor measurements have been compared with both a numerical model based on Finite Elements and traditional piezoelectric sensors, confirming a good agreement between experimental and simulated results for both active and passive impact monitoring scenarios. PMID:28773154

Multisample cross-validation of a model of childhood posttraumatic stress disorder symptomatology.

PubMed

Anthony, Jason L; Lonigan, Christopher J; Vernberg, Eric M; Greca, Annette M La; Silverman, Wendy K; Prinstein, Mitchell J

2005-12-01

This study is the latest advancement of our research aimed at best characterizing children's posttraumatic stress reactions. In a previous study, we compared existing nosologic and empirical models of PTSD dimensionality and determined the superior model was a hierarchical one with three symptom clusters (Intrusion/Active Avoidance, Numbing/Passive Avoidance, and Arousal; Anthony, Lonigan, & Hecht, 1999). In this study, we cross-validate this model in two populations. Participants were 396 fifth graders who were exposed to either Hurricane Andrew or Hurricane Hugo. Multisample confirmatory factor analysis demonstrated the model's factorial invariance across populations who experienced traumatic events that differed in severity. These results show the model's robustness to characterize children's posttraumatic stress reactions. Implications for diagnosis, classification criteria, and an empirically supported theory of PTSD are discussed.

A data-driven and physics-based single-pass retrieval of active-passive microwave covariation and vegetation parameters for the SMAP mission

NASA Astrophysics Data System (ADS)

Entekhabi, D.; Jagdhuber, T.; Das, N. N.; Baur, M.; Link, M.; Piles, M.; Akbar, R.; Konings, A. G.; Mccoll, K. A.; Alemohammad, S. H.; Montzka, C.; Kunstmann, H.

2016-12-01

The active-passive soil moisture retrieval algorithm of NASA's SMAP mission depends on robust statistical estimation of active-passive covariation (β) and vegetation structure (Γ) parameters in order to provide reliable global measurements of soil moisture on an intermediate level (9km) compared to the native resolution of the radiometer (36km) and radar (3km) instruments. These parameters apply to the SMAP radiometer-radar combination over the period of record that was cut short with the end of the SMAP radar transmission. They also apply to the current SMAP radiometer and Sentinel 1A/B radar combination for high-resolution surface soil moisture mapping. However, the performance of the statistically-based approach is directly dependent on the selection of a representative time frame in which these parameters can be estimated assuming dynamic soil moisture and stationary soil roughness and vegetation cover. Here, we propose a novel, data-driven and physics-based single-pass retrieval of active-passive microwave covariation and vegetation parameters for the SMAP mission. The algorithm does not depend on time series analyses and can be applied using minimum one pair of an active-passive acquisition. The algorithm stems from the physical link between microwave emission and scattering via conservation of energy. The formulation of the emission radiative transfer is combined with the Distorted Born Approximation of radar scattering for vegetated land surfaces. The two formulations are simultaneously solved for the covariation and vegetation structure parameters. Preliminary results from SMAP active-passive observations (April 13th to July 7th 2015) compare well with the time-series statistical approach and confirms the capability of this method to estimate these parameters. Moreover, the method is not restricted to a given frequency (applies to both L-band and C-band combinations for the radar) or incidence angle (all angles and not just the fixed 40° incidence). Therefore, the approach is applicable to the combination of SMAP and Sentinel-1A/B data for active-passive and high-resolution soil moisture estimation.

Design, synthesis and nootropic activity of new analogues of sunifiram and sapunifiram, two potent cognition-enhancers.

PubMed

Martini, Elisabetta; Salvicchi, Alberto; Ghelardini, Carla; Manetti, Dina; Dei, Silvia; Guandalini, Luca; Martelli, Cecilia; Melchiorre, Michele; Cellai, Cristina; Scapecchi, Serena; Teodori, Elisabetta; Romanelli, Maria Novella

2009-11-01

A series of amides and sulfonamides, structurally related to DM235 (sunifiram) and MN19 (sapunifiram), derived by ring expansion or contraction, or by inversion of the exocyclic amide function, have been synthesized and tested for cognition-enhancing activity in the mouse passive-avoidance test. Some of the compounds display good antiamnesic and procognitive activity, with higher potency than piracetam, and with a potency similar to the parent compounds.

Implementing a Multiplexed System of Detectors for Higher Photon Counting Rates

DTIC Science & Technology

2007-01-01

D1 D2 Fig. 3. (a) Setup for testing different arrangements of InGaAs SPAD assemblies; (b) three different InGaAs SPAD assemblies; ( c ) schematic of...presently available, either commercial or prototype, the deadtimes range from ≈50 ns for actively quenched single photon avalanche detectors ( SPADs ...to ≈10 µs for passively quenched SPADs , although even actively quenched SPADs sometimes employ µs deadtimes to avoid excessive afterpulsing rates. In

An examination of the roles of glutamate and sex in latent inhibition: Relevance to the glutamate hypothesis of schizophrenia?

PubMed

Huang, Andrew Chih Wei; Bo-Han He, Alan; Chen, Chih-Chung

2017-10-01

The present study examined the effects of the glutamate receptor antagonist MK-801, the glutamate receptor agonist N-methyl-D-aspartate (NMDA), and sexual dimorphism on latent inhibition to elucidate the glutamate hypothesis of schizophrenia. During the pre-exposure phase, 56 male and 65 female Wistar rats were intracerebroventricularly administered normal saline, MK-801 or NMDA, in the left ventricle and then exposed to a passive avoidance box (or a different context) in three trials over 3 days. Then, all of the rats were placed in the light compartment of the passive avoidance box and were allowed to enter the dark compartment, where they each received a footshock (1mA, 2s) in five trials over 5 days. Injections of the glutamate drugs NMDA and MK-801 did not affect latent inhibition. Sexual dimorphism did not occur in latent inhibition. The present data on the male rats indicated that the glutamate system did not affect latent inhibition, indicating that the glutamate system was not like the dopamine system in terms of mediating the positive symptoms of schizophrenia. The glutamate system might be involved in the negative and cognitive symptoms of schizophrenia. The results may provide information for novel treatments of the negative and cognitive symptoms of schizophrenia. Copyright © 2017 Elsevier B.V. All rights reserved.

Pervasive hyperactivity and long-term learning impairments in rats with induced micrencephaly from prenatal exposure to methylazoxymethanol.

PubMed

Vorhees, C V; Fernandez, K; Dumas, R M; Haddad, R K

1984-07-01

Pregnant Long-Evans rats were given a single i.p. injection of 30 mg/kg of methylazoxymethanol (MAM) acetate or saline on day 14 of gestation (vaginal plug = day 0). All litters were reduced to 8 at birth and were reared by their biological dams. Between 49-192 days of age all offspring were examined on open-field, figure-8 (at two different ages), and hole-board tests of activity, as well as passive avoidance and Biel water maze tests of learning (also at two different ages). The MAM offspring showed no increase in mortality, but weighed less than controls, a difference that remained relatively constant throughout the experiment. At 204-215 days of age the MAM offspring were confirmed to be micrencephalic, a known effect of this drug at this dose and exposure period. On all tests of activity the MAM offspring were markedly hyperactive. The female progeny also exhibited a pronounced impairment of normal activity habituation patterns. The MAM males, however, showed a marked impairment of passive avoidance performance, while the females did not. At 2 months of age the MAM offspring also showed a pronounced deficit in learning a water maze. This maze deficit had not abated when tested again at 6 months of age. The MAM induced brain and behavioral abnormalities provide a potentially useful animal model of congenital micrencephaly and associated mental retardation.

Phytochemical analysis, antioxidant, antistress, and nootropic activities of aqueous and methanolic seed extracts of ladies finger (Abelmoschus esculentus L.) in mice.

PubMed

Doreddula, Sathish Kumar; Bonam, Srinivasa Reddy; Gaddam, Durga Prasad; Desu, Brahma Srinivasa Rao; Ramarao, Nadendla; Pandy, Vijayapandi

2014-01-01

Abelmoschus esculentus L. (ladies finger, okra) is a well-known tropical vegetable, widely planted from Africa to Asia and from South Europe to America. In the present study, we investigated the in vitro antioxidant capacity and in vivo protective effect of the aqueous and methanolic seed extracts of Abelmoschus esculentus against scopolamine-induced cognitive impairment using passive avoidance task and acute restraining stress-induced behavioural and biochemical changes using elevated plus maze (EPM) and forced swimming test (FST) in mice. Our results demonstrated that the pretreatment of mice with aqueous and methanolic seed extracts of Abelmoschus esculentus (200 mg/kg, p.o.) for seven days significantly (P < 0.01) attenuated scopolamine-induced cognitive impairment in the passive avoidance test. In addition, these extracts significantly reduced the blood glucose, corticosterone, cholesterol, and triglyceride levels elevated by acute restraint stress and also significantly increased the time spent in open arm in EPM and decreased the immobility time in FST. It has also been revealed that these extracts showed a significant antioxidant activity and no signs of toxicity or death up to a dose of 2000 mg/kg, p.o. These results suggest that the seed extracts of Abelmoschus esculentus L. possess antioxidant, antistress, and nootropic activities which promisingly support the medicinal values of ladies finger as a vegetable.

Neurotoxicity of neem commercial formulation (Azadirachta indica A. Juss) in adult zebrafish (Danio rerio).

PubMed

Bernardi, M M; Dias, S G; Barbosa, V E

2013-11-01

The neurotoxic effects of a commercial formulation of Azadirachta indica A. Juss, also called neem or nim, in adult zebrafish were determined using behavioral models. General activity, anxiety-like effects, and learning and memory in a passive avoidance task were assessed after exposure to 20 or 40 μl/L neem. The results showed that 20 μl/L neem reduced the number of runs. Both neem concentrations increased the number of climbs to the water surface, and 40 μl/L increased the number of tremors. In the anxiety test, the 20 μl/L dose increased the number of entries in the light side compared with controls, but the latency to enter the dark side and the freezing behavior in this side did not changed. In relation to controls, the 40 μl/L neem reduced the latency to enter in the light side, did not change the number of entries in this side and increased freezing behavior in the light side. In the passive avoidance test, pre-training and pre-test neem exposure to 40 μl/L decreased the response to the learning task. Thus, no impairment was observed in this behavioral test. We conclude that neem reduced general activity and increased anxiety-like behavior but did not affect learning and memory. Copyright © 2013 Elsevier B.V. All rights reserved.

Phytochemical Analysis, Antioxidant, Antistress, and Nootropic Activities of Aqueous and Methanolic Seed Extracts of Ladies Finger (Abelmoschus esculentus L.) in Mice

PubMed Central

Doreddula, Sathish Kumar; Bonam, Srinivasa Reddy; Gaddam, Durga Prasad; Desu, Brahma Srinivasa Rao; Ramarao, Nadendla; Pandy, Vijayapandi

2014-01-01

Abelmoschus esculentus L. (ladies finger, okra) is a well-known tropical vegetable, widely planted from Africa to Asia and from South Europe to America. In the present study, we investigated the in vitro antioxidant capacity and in vivo protective effect of the aqueous and methanolic seed extracts of Abelmoschus esculentus against scopolamine-induced cognitive impairment using passive avoidance task and acute restraining stress-induced behavioural and biochemical changes using elevated plus maze (EPM) and forced swimming test (FST) in mice. Our results demonstrated that the pretreatment of mice with aqueous and methanolic seed extracts of Abelmoschus esculentus (200 mg/kg, p.o.) for seven days significantly (P < 0.01) attenuated scopolamine-induced cognitive impairment in the passive avoidance test. In addition, these extracts significantly reduced the blood glucose, corticosterone, cholesterol, and triglyceride levels elevated by acute restraint stress and also significantly increased the time spent in open arm in EPM and decreased the immobility time in FST. It has also been revealed that these extracts showed a significant antioxidant activity and no signs of toxicity or death up to a dose of 2000 mg/kg, p.o. These results suggest that the seed extracts of Abelmoschus esculentus L. possess antioxidant, antistress, and nootropic activities which promisingly support the medicinal values of ladies finger as a vegetable. PMID:25401145

Deficient behavioral inhibition and anomalous selective attention in a community sample of adolescents with psychopathic traits and low-anxiety traits.

PubMed

Vitale, Jennifer E; Newman, Joseph P; Bates, John E; Goodnight, Jackson; Dodge, Kenneth A; Pettit, Gregory S

2005-08-01

Socialization is the important process by which individuals learn and then effectively apply the rules of appropriate societal behavior. Response modulation is a psychobiological process theorized to aid in socialization by allowing individuals to utilize contextual information to modify ongoing behavior appropriately. Using Hare's (1991) Psychopathy Checklist and the Welsh (1956) anxiety scale, researchers have identified a relatively specific form of a response modulation deficit in low-anxious, Caucasian psychopaths. Preliminary evidence suggests that the Antisocial Process Screening Device (APSD; Frick & Hare, 2001) may be used to identify children with a similar vulnerability. Using a representative community sample of 308 16-year-olds from the Child Development Project (Dodge, Bates, & Pettit, 1990), we tested and corroborated the hypotheses that participants with relatively low anxiety and high APSD scores would display poorer passive avoidance learning and less interference on a spatially separated, picture-word Stroop task than controls. Consistent with hypotheses, the expected group differences in picture-word Stroop interference were found with male and female participants, whereas predicted differences in passive avoidance were specific to male participants. To the extent that response modulation deficits contributing to poor socialization among psychopathic adult offenders also characterize a subgroup of adolescents with mild conduct problems, clarification of the developmental processes that moderate the expression of this vulnerability could inform early interventions.

Operation in low edge safety factor regime and passive disruption avoidance due to stellarator rotational transform in the Compact Toroidal Hybrid

NASA Astrophysics Data System (ADS)

Pandya, M. D.; Ennis, D. A.; Hartwell, G. J.; Maurer, D. A.

2015-11-01

Low edge safety factor operation at a value less than two (q (a) = 1 /ttot (a) < 2) is routine on the Compact Toroidal Hybrid device. Presently, the operational space of this current carrying stellarator extends down to q (a) = 1 . 2 without significant n = 1 kink mode activity after the initial plasma current rise of the discharge. The disruption dynamics of these low q (a) plasmas depend upon the fraction of rotational transform produced by external stellarator coils to that generated by the plasma current. We observe that when about 10% of the total rotational transform is supplied by the stellarator coils, low q (a) disruptions are passively suppressed and avoided even though q (a) < 2 . When the plasma does disrupt, the instability precursors measured and implicated as the cause are internal tearing modes with poloidal, m, and toroidal, n, mode numbers of m / n = 3 / 2 and 4 / 3 observed by external magnetic sensors, and m / n = 1 / 1 activity observed by core soft x-ray emissivity measurements. Even though q (a) passes through and becomes much less than two, external n = 1 kink mode activity does not appear to play a significant role in the observed disruption phenomenology. This work is supported by US Department of Energy Grant No. DE-FG02-00ER54610.

Low edge safety factor operation and passive disruption avoidance in current carrying plasmas by the addition of stellarator rotational transform

NASA Astrophysics Data System (ADS)

Pandya, M. D.; ArchMiller, M. C.; Cianciosa, M. R.; Ennis, D. A.; Hanson, J. D.; Hartwell, G. J.; Hebert, J. D.; Herfindal, J. L.; Knowlton, S. F.; Ma, X.; Massidda, S.; Maurer, D. A.; Roberds, N. A.; Traverso, P. J.

2015-11-01

Low edge safety factor operation at a value less than two ( q (a )=1 /ι̷tot(a )<2 ) is routine on the Compact Toroidal Hybrid device with the addition of sufficient external rotational transform. Presently, the operational space of this current carrying stellarator extends down to q (a )=1.2 without significant n = 1 kink mode activity after the initial plasma current rise phase of the discharge. The disruption dynamics of these low edge safety factor plasmas depend upon the fraction of helical field rotational transform from external stellarator coils to that generated by the plasma current. We observe that with approximately 10% of the total rotational transform supplied by the stellarator coils, low edge q disruptions are passively suppressed and avoided even though q(a) < 2. When the plasma does disrupt, the instability precursors measured and implicated as the cause are internal tearing modes with poloidal, m, and toroidal, n, helical mode numbers of m /n =3 /2 and 4/3 observed on external magnetic sensors and m /n =1 /1 activity observed on core soft x-ray emissivity measurements. Even though the edge safety factor passes through and becomes much less than q(a) < 2, external n = 1 kink mode activity does not appear to play a significant role in the disruption phenomenology observed.

Impact of leadership styles adopted by head nurses on job satisfaction: a comparative study between governmental and private hospitals in Jordan.

PubMed

Abdelhafiz, Ibrahim Mbarak; Alloubani, Aladeen Mah'D; Almatari, Mohammad

2016-04-01

Previous studies demonstrated that leadership styles are the basis of daily interactions between leaders and employees and facilitate and enhance work processes. This study aimed to explore how the leadership styles of nurse leaders affect job satisfaction among working nurses. Quantitative, descriptive and comparative methods were used. Three main Ministry of Health hospitals in different areas of Jordan and three private hospitals in Amman were selected. Among the leadership styles measured by the Multi-factor Leadership Questionnaire 5X, transformational leadership had been used by head nurse managers in both settings more than transactional leadership and passive-avoidant leadership. The level of job satisfaction among nursing staff was higher in public hospitals than in private hospitals in this study. A positive relationship was found between the overall score for transformational leadership and job satisfaction (r = 0.374**). The overall transactional leadership score correlated positively with job satisfaction (r = 0.391**). Conversely, the overall correlation between passive-avoidant leadership and job satisfaction was negative (r = -0.240). The increased development of transformational leadership behaviours increases nurses' job satisfaction and thus contributes to an increased retention of nurses. The ability of hospitals to address the leadership styles of head nurses and their impacts on job satisfaction will be strengthened. © 2015 John Wiley & Sons Ltd.

Prediction Error Representation in Individuals with Generalized Anxiety Disorder During Passive Avoidance

PubMed Central

White, Stuart F.; Geraci, Marilla; Lewis, Elizabeth; Leshin, Joseph; Teng, Cindy; Averbeck, Bruno; Meffert, Harma; Ernst, Monique; Blair, James R.; Grillon, Christian; Blair, Karina S.

2017-01-01

Objective Deficits in reinforcement-based decision-making have been reported in Generalized Anxiety Disorder. However, the pathophysiology of these deficits is largely unknown, extant studies have mainly examined youth and the integrity of core functional processes underpinning decision-making remain undetermined. In particular, it is unclear whether the representation of reinforcement prediction error (PE: the difference between received and expected reinforcement) is disrupted in Generalized Anxiety Disorder. The current study addresses these issues in adults with the disorder. Methods Forty-six un-medicated individuals with Generalized Anxiety Disorder and 32 healthy controls group-matched on IQ, gender and age, completed a passive avoidance task while undergoing functional MRI. Results Behaviorally, individuals with Generalized Anxiety Disorder showed impaired reinforcement-based decision-making. Imaging results revealed that during feedback, individuals with Generalized Anxiety Disorder relative to healthy controls showed a reduced correlation between PE and activity within ventromedial prefrontal cortex, ventral striatum and other structures implicated in decision-making. In addition, individuals with Generalized Anxiety Disorder relative to healthy participants showed a reduced correlation between punishment, but not reward, PEs and activity within bilateral lentiform nucleus/putamen. Conclusions This is the first study to identify computational impairments during decision-making in Generalized Anxiety Disorder. PE signaling is significantly disrupted in individuals with the disorder and may underpin the decision-making deficits observed in patients with GAD. PMID:27631963