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Sample records for stimulating conditions significantly

  1. Formal conditions for the significance-effect

    DEFF Research Database (Denmark)

    Thellefsen, Torkild Leo; Sørensen, Bent; Thellefsen, Martin

    2006-01-01

    The significance-effect is the right effect of meaning caused upon an interpreting mind. The right effect is understood as the right interpretation of an intended meaning caused by a sign communicated by an utterer. In the article, which is inspired by Charles S. Peirce's doctrine of signs, his s...... semeiotics and his theory of communication, we account for the formal conditions that have to be present for the release of the significance-effect....

  2. Consecutive Acupuncture Stimulations Lead to Significantly Decreased Neural Responses

    NARCIS (Netherlands)

    Yeo, S.; Choe, I.H.; Noort, M.W.M.L. van den; Bosch, M.P.C.; Lim, S.

    2010-01-01

    Objective: Functional magnetic resonance imaging (fMRI), in combination with block design paradigms with consecutive acupuncture stimulations, has often been used to investigate the neural responses to acupuncture. In this study, we investigated whether previous acupuncture stimulations can affect

  3. Stimulating Sustainability in Multinational Companies: the Significance of Regional Headquarters

    Directory of Open Access Journals (Sweden)

    Andreas G. M. NACHBAGAUER

    2016-06-01

    Full Text Available Recently, regional headquarters have gained practical importance and theoretical attention. Traditionally considered a mere transmission facility to manage complex organisations, advanced approaches, however, locate regional headquarters in a field of tension between hierarchical integration and strategic independence. Given the growing concern for global responsibility, stimulating sustainability also and particularly addresses regional headquarters. This conceptual article combines the call for sustainability with the upcoming importance of regional headquarters: which contributions can the regional headquarters of a multinational company deliver to stimulate the development of sustainable corporate strategy and operations? The main topics are the effects different versions of embedding regional headquarters into the corporate context have on opportunities to implement sustainability policies: Are there different chances for successful implementation depending on the strategic setup of the company? Does the distribution of competences matter? Which types of interaction between headquarters and branch are suitable to introduce sustainability sustainably? Is the mix of national contexts of headquarters and branch of importance? First results show that depending on the companywide strategy, and especially on the structure and distribution of competences, regional headquarters can play a significant role as trigger of sustainability. The literature favours strong involvement and large autonomy of both branches as well as regional headquarters for the development and management of sustainability. The parts of the company involved in a critical environment often are the starting point of sustainability policies.

  4. Stimulating Sustainability in Multinational Companies: the Significance of Regional Headquarters

    OpenAIRE

    Andreas G. M. NACHBAGAUER

    2016-01-01

    Recently, regional headquarters have gained practical importance and theoretical attention. Traditionally considered a mere transmission facility to manage complex organisations, advanced approaches, however, locate regional headquarters in a field of tension between hierarchical integration and strategic independence. Given the growing concern for global responsibility, stimulating sustainability also and particularly addresses regional headquarters. This conceptual article combines the call...

  5. Gene expression results in lipopolysaccharide-stimulated monocytes depend significantly on the choice of reference genes

    Directory of Open Access Journals (Sweden)

    Øvstebø Reidun

    2010-05-01

    Full Text Available Abstract Background Gene expression in lipopolysaccharide (LPS-stimulated monocytes is mainly studied by quantitative real-time reverse transcription PCR (RT-qPCR using GAPDH (glyceraldehyde 3-phosphate dehydrogenase or ACTB (beta-actin as reference gene for normalization. Expression of traditional reference genes has been shown to vary substantially under certain conditions leading to invalid results. To investigate whether traditional reference genes are stably expressed in LPS-stimulated monocytes or if RT-qPCR results are dependent on the choice of reference genes, we have assessed and evaluated gene expression stability of twelve candidate reference genes in this model system. Results Twelve candidate reference genes were quantified by RT-qPCR in LPS-stimulated, human monocytes and evaluated using the programs geNorm, Normfinder and BestKeeper. geNorm ranked PPIB (cyclophilin B, B2M (beta-2-microglobulin and PPIA (cyclophilin A as the best combination for gene expression normalization in LPS-stimulated monocytes. Normfinder suggested TBP (TATA-box binding protein and B2M as the best combination. Compared to these combinations, normalization using GAPDH alone resulted in significantly higher changes of TNF-α (tumor necrosis factor-alpha and IL10 (interleukin 10 expression. Moreover, a significant difference in TNF-α expression between monocytes stimulated with equimolar concentrations of LPS from N. meningitides and E. coli, respectively, was identified when using the suggested combinations of reference genes for normalization, but stayed unrecognized when employing a single reference gene, ACTB or GAPDH. Conclusions Gene expression levels in LPS-stimulated monocytes based on RT-qPCR results differ significantly when normalized to a single gene or a combination of stably expressed reference genes. Proper evaluation of reference gene stabiliy is therefore mandatory before reporting RT-qPCR results in LPS-stimulated monocytes.

  6. Medial prefrontal cortex stimulation modulates the processing of conditioned fear

    Directory of Open Access Journals (Sweden)

    Anne eGuhn

    2014-02-01

    Full Text Available The extinction of conditioned fear is dependent on an efficient interplay between the amygdala and the medial prefrontal cortex (mPFC. In rats, high-frequency electrical mPFC stimulation was shown to improve extinction by a reduction of amygdala activity. However, so far it is unclear whether stimulation of homologues regions in humans might have similar beneficial effects.Healthy volunteers received one-session of either active or sham repetitive transcranial magnetic stimulation (rTMS covering the mPFC while undergoing a two-day fear conditioning and extinction paradigm. rTMS was applied offline after fear acquisition in which one of two faces (CS+ but not CS- was associated with an aversive scream (UCS. Immediate extinction learning (day 1 and extinction recall (day 2 were conducted without UCS delivery. Conditioned responses were assessed in a multimodal approach using fear-potentiated startle (FPS, skin conductance responses (SCR, functional near-infrared spectroscopy (fNIRS and self-report scales. Consistent with the hypothesis of a modulated processing of conditioned fear after high-frequency rTMS, the active group showed a reduced CS+/CS- discrimination during extinction learning as evident in FPS as well as in SCR and arousal ratings. FPS responses to CS+ further showed a linear decrement throughout both extinction sessions. This study describes the first experimental approach of influencing conditioned fear by using rTMS which can be a basis for future studies investigating a complementation of mPFC stimulation to cognitive behavioral therapy.

  7. Simultaneous bilateral stereotactic procedure for deep brain stimulation implants: a significant step for reducing operation time.

    Science.gov (United States)

    Fonoff, Erich Talamoni; Azevedo, Angelo; Angelos, Jairo Silva Dos; Martinez, Raquel Chacon Ruiz; Navarro, Jessie; Reis, Paul Rodrigo; Sepulveda, Miguel Ernesto San Martin; Cury, Rubens Gisbert; Ghilardi, Maria Gabriela Dos Santos; Teixeira, Manoel Jacobsen; Lopez, William Omar Contreras

    2016-07-01

    OBJECT Currently, bilateral procedures involve 2 sequential implants in each of the hemispheres. The present report demonstrates the feasibility of simultaneous bilateral procedures during the implantation of deep brain stimulation (DBS) leads. METHODS Fifty-seven patients with movement disorders underwent bilateral DBS implantation in the same study period. The authors compared the time required for the surgical implantation of deep brain electrodes in 2 randomly assigned groups. One group of 28 patients underwent traditional sequential electrode implantation, and the other 29 patients underwent simultaneous bilateral implantation. Clinical outcomes of the patients with Parkinson's disease (PD) who had undergone DBS implantation of the subthalamic nucleus using either of the 2 techniques were compared. RESULTS Overall, a reduction of 38.51% in total operating time for the simultaneous bilateral group (136.4 ± 20.93 minutes) as compared with that for the traditional consecutive approach (220.3 ± 27.58 minutes) was observed. Regarding clinical outcomes in the PD patients who underwent subthalamic nucleus DBS implantation, comparing the preoperative off-medication condition with the off-medication/on-stimulation condition 1 year after the surgery in both procedure groups, there was a mean 47.8% ± 9.5% improvement in the Unified Parkinson's Disease Rating Scale Part III (UPDRS-III) score in the simultaneous group, while the sequential group experienced 47.5% ± 15.8% improvement (p = 0.96). Moreover, a marked reduction in the levodopa-equivalent dose from preoperatively to postoperatively was similar in these 2 groups. The simultaneous bilateral procedure presented major advantages over the traditional sequential approach, with a shorter total operating time. CONCLUSIONS A simultaneous stereotactic approach significantly reduces the operation time in bilateral DBS procedures, resulting in decreased microrecording time, contributing to the optimization of functional

  8. Medial Auditory Thalamic Stimulation as a Conditioned Stimulus for Eyeblink Conditioning in Rats

    Science.gov (United States)

    Campolattaro, Matthew M.; Halverson, Hunter E.; Freeman, John H.

    2007-01-01

    The neural pathways that convey conditioned stimulus (CS) information to the cerebellum during eyeblink conditioning have not been fully delineated. It is well established that pontine mossy fiber inputs to the cerebellum convey CS-related stimulation for different sensory modalities (e.g., auditory, visual, tactile). Less is known about the…

  9. Significant plant growth stimulation by composted as opposed to untreated Biochar

    Science.gov (United States)

    Kammann, Claudia; Messerschmidt, Nicole; Müller, Christoph; Steffens, Diedrich; Schmidt, Hans-Peter; Koyro, Hans-Werner

    2013-04-01

    stimulation was most pronounced when the growth conditions were the most unfavorable (no compost addition + low fertilization: aged BC 305% versus fresh BC 61% of zero-BC). The stimulation was least pronounced in the treatment where the growth conditions were most favorable (compost addition + high fertilization). However, despite the higher fertility and higher nitrate values the mixtures with the composted biochar did not show higher N2O emissions. Reasons for the strong significant change in plant growth promotion, i.e. changes on the biochar surfaces that occur during the composting, will be discussed. Fischer D, Glaser B (2012) Synergisms between compost and biochar for sustainable soil amelioration. In: Management of Organic Waste. (eds Sunil K, Bharti A), ISBN 978-953-307-925-7, Chapter 10, pp. 167-198.

  10. Modulation of itch by conditioning itch and pain stimulation in healthy humans

    DEFF Research Database (Denmark)

    Andersen, Hjalte Holm; van Laarhoven, Antoinette I. M.; Elberling, Jesper

    2017-01-01

    Little is known about endogenous descending control of itch. In chronic pain, descending pain inhibition is reduced as signified by lowered conditioned pain modulation (CPM). There are indications that patients with chronic itch may also exhibit reduced endogenous descending inhibition of itch......-evoked itch, while the test stimuli were electrical stimulation paradigms designed to evoke itch or pain. Pain was significantly reduced (CPM-effect) by the conditioning pain stimulus (p

  11. Pavlovian conditioning of psychomotor stimulant-induced behaviours: has convenience led us astray?

    Science.gov (United States)

    Martin-Iverson, M.T.; Fawcett, S.L.

    1996-01-01

    In order to classically condition the behavioural effects of psychomotor stimulants within a test context, rats were treated for 10 days with (+)-amphetamine (1.5mg/kg), (+)-4-propyl-9-hydroxynaphthoxazine (PHNO, 30µg/kg) or vehicle prior to a 1h placement into a test box. Conditioned behavioural effects were then measured in the previously drug-paired context after a vehicle injection (drug-free test day). Each rat was videotaped for the 1h test box exposure on days 1, 4, 7 and 10 of the drug conditioning trials, and on the drug-free test day. Eleven of 28 behaviours that were scored for frequency, duration and mean bout duration (bout length) were significantly influenced by at least one of the two drugs. Amphetamine predominantly increased bout lengths while PHNO predominantly increased bout frequency. Only two measures that were influenced by the drugs exhibited clear increases over controls in a manner consistent with a classical conditioning interpretation. Behavioural sensitization clearly occurred to some of the effects of amphetamine and PHNO, but these were not the same effects as those increased on the non-drug day testing for classical conditioning. Most behavioural effects of amphetamine and PHNO are not classically conditioned, and behavioural sensitization to these drugs, while perhaps context-specific, is not due to classical conditioning. Automated measures of behaviours have provided misleading evidence concerning the similarity among behavioural effects of stimulants, sensitization and effects of exposure to an environment previously paired with stimulants. Analysis of transitions between behaviours does not support the view that stimulants increase switching or response competition, or that behavioural reorganization is responsible for sensitization. Rather, it is suggested that stimulants selectively facilitate current stimulus-guided behaviours.

  12. Assurance of Fault Management: Risk-Significant Adverse Condition Awareness

    Science.gov (United States)

    Fitz, Rhonda

    2016-01-01

    Fault Management (FM) systems are ranked high in risk-based assessment of criticality within flight software, emphasizing the importance of establishing highly competent domain expertise to provide assurance for NASA projects, especially as spaceflight systems continue to increase in complexity. Insight into specific characteristics of FM architectures seen embedded within safety- and mission-critical software systems analyzed by the NASA Independent Verification Validation (IVV) Program has been enhanced with an FM Technical Reference (TR) suite. Benefits are aimed beyond the IVV community to those that seek ways to efficiently and effectively provide software assurance to reduce the FM risk posture of NASA and other space missions. The identification of particular FM architectures, visibility, and associated IVV techniques provides a TR suite that enables greater assurance that critical software systems will adequately protect against faults and respond to adverse conditions. The role FM has with regard to overall asset protection of flight software systems is being addressed with the development of an adverse condition (AC) database encompassing flight software vulnerabilities.Identification of potential off-nominal conditions and analysis to determine how a system responds to these conditions are important aspects of hazard analysis and fault management. Understanding what ACs the mission may face, and ensuring they are prevented or addressed is the responsibility of the assurance team, which necessarily should have insight into ACs beyond those defined by the project itself. Research efforts sponsored by NASAs Office of Safety and Mission Assurance defined terminology, categorized data fields, and designed a baseline repository that centralizes and compiles a comprehensive listing of ACs and correlated data relevant across many NASA missions. This prototype tool helps projects improve analysis by tracking ACs, and allowing queries based on project, mission

  13. Some conditions for significant contribution from photovoltaics to sustainable development

    International Nuclear Information System (INIS)

    Coiante, D.

    1994-03-01

    In medium-long term perspective, the anthropogenic atmospheric pollution, due to fossil fuel burning, could be contained by massively using of renewable energy. Significant improvements are expected to arise from diffusion into use of large scale PV power systems. Considering the situation in Italy as a typical study case, a limit can be individuated, which makes that PV contribution to annual electric energy balance can reach a maximum of about 7%. Such a figure corresponds to about 2% in terms of contribution to total energy balance. Thus, the intermittent energy sources are destined, in Italy, to be confined to a role, just significant (7%) in the electric energy sector, but quite marginal (2%) with reference to expected environmental massive benefits. Apart from numerical results, this disappointing concept can be applied in general to all OCSE countries, wich globally produce the largest amount of world pollutant energy. Consequently, if photovoltaics wants to acquire a real environmental consistence, the limit of PV system diffusion has to be overcome. This can be attained by implementing the present grid-tied reference model for PV system diffusion by including an hydrogen production and storage system

  14. Spontaneous pneumomediastinum on CT : related condition and its clinical significance

    International Nuclear Information System (INIS)

    Kim, Sung Hyun; Im, Jung Gi; Seo, Joon Beom; Park, Jae Hyung; Yeon, Kyung Mo; Han, Man Chung

    1998-01-01

    The purpose of this paper is to tabulate underlying disease and to assess the clinical significance of CT-diagnosed spontaneous pneumomediastinum. We retrospectively reviewed CT scans and medical records of 11 consecutive patients with spontaneous pneumomediastinum, and analyzed their clinical history and course, and in five cases, pulmonary function. CT scans of 126 patients with idiopathic pulmonary fibrosis (IPE) collected while the 11 consecutive patients were being treated were analyzed for the prevalence of pneumomediastinum. We analyzed CT findings with respect to the amount and distribution of air in the mediastinum, and the presence of absence of air outside the mediastinum. Spontaneous pneumomediastinum might be associated with idiopathic pulmonary fibrosis and might be a poor prognostic factor in patients with IPE or BOOP. (author). 18 refs., 2 figs

  15. Spontaneous pneumomediastinum on CT : related condition and its clinical significance

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Hyun; Im, Jung Gi; Seo, Joon Beom; Park, Jae Hyung; Yeon, Kyung Mo; Han, Man Chung [Seoul National Univ. (Korea, Republic of). Coll. of Medicine

    1998-03-01

    The purpose of this paper is to tabulate underlying disease and to assess the clinical significance of CT-diagnosed spontaneous pneumomediastinum. We retrospectively reviewed CT scans and medical records of 11 consecutive patients with spontaneous pneumomediastinum, and analyzed their clinical history and course, and in five cases, pulmonary function. CT scans of 126 patients with idiopathic pulmonary fibrosis (IPE) collected while the 11 consecutive patients were being treated were analyzed for the prevalence of pneumomediastinum. We analyzed CT findings with respect to the amount and distribution of air in the mediastinum, and the presence of absence of air outside the mediastinum. Spontaneous pneumomediastinum might be associated with idiopathic pulmonary fibrosis and might be a poor prognostic factor in patients with IPE or BOOP. (author). 18 refs., 2 figs.

  16. Evidence of Pavlovian conditioned fear following electrical stimulation of the periaqueductal grey in the rat.

    Science.gov (United States)

    Di Scala, G; Mana, M J; Jacobs, W J; Phillips, A G

    1987-01-01

    Stimulation of the periaqueductal grey (PAG) has been used to support aversive conditioning in a variety of species with several experimental paradigms. However, it has not been clearly demonstrated whether the behavioral changes produced by PAG stimulation in these paradigms are mediated by associative or nonassociative mechanisms. The present studies demonstrate that electrical stimulation of the PAG in the rat may be used to support associative learning in a Pavlovian paradigm. In each experiment, a fully controlled conditional emotional response (CER) procedure was used to examine the unconditional aversive properties of PAG stimulation. In Experiment 1a, weak associative conditioning was observed when a light CS was paired with PAG stimulation over 6 conditioning trials. In Experiment 1b, robust associative conditioning was obtained with a light CS when 18 conditioning trials were used. In Experiment 2, robust associative conditioning was demonstrated with a tone CS when 6 conditioning trials were used. The results parallel those found when other aversive stimuli are used as a UCS (e.g., footshock or intraorbital air puff), and because the present experiments included the proper control procedures the results clearly indicate that the behavioral changes produced by PAG stimulation are mediated by associative Pavlovian learning mechanisms rather than nonassociative mechanisms such as sensitization or pseudoconditioning. The present technique may be useful for assessing the neuroanatomical and neurochemical substrates underlying the aversive effects of brain-stimulation, and for screening the effects of drugs on the conditional and unconditional responses produced by such stimulation.

  17. Deep Brain Stimulation Target Selection in an Advanced Parkinson's Disease Patient with Significant Tremor and Comorbid Depression

    Directory of Open Access Journals (Sweden)

    Amar S. Patel

    2017-04-01

    Full Text Available Clinical Vignette: A 67-year-old female with advanced Parkinson's disease (PD, medically refractory tremor, and a history of significant depression presents for evaluation of deep brain stimulation (DBS candidacy.  Clinical Dilemma: Traditionally, stimulation of the subthalamic nucleus (STN has been the preferred target for patients with significant PD tremor. However, STN stimulation is avoided in patients with a significant pre-surgical history of mood disorder.  Clinical Solution: Bilateral DBS of the globus pallidus interna led to significant short term improvement in PD motor symptoms, including significant tremor reduction.  Gap in Knowledge: There is insufficient evidence to support or refute clinicians' traditional preference for STN stimulation in treating refractory PD tremor. Similarly, the available evidence for risk of worsening depression and/or suicidality after STN DBS is mixed. Both questions require further clarification to guide patient and clinician decision-making.

  18. Operant conditioning of rat navigation using electrical stimulation for directional cues and rewards.

    Science.gov (United States)

    Lee, Maan-Gee; Jun, Gayoung; Choi, Hyo-Soon; Jang, Hwan Soo; Bae, Yong Chul; Suk, Kyoungho; Jang, Il-Sung; Choi, Byung-Ju

    2010-07-01

    Operant conditioning is often used to train a desired behavior in an animal. The contingency between a specific behavior and a reward is required for successful training. Here, we compared the effectiveness of two different mazes for training turning behaviors in response to directional cues in Sprague-Dawley rats. Forty-three rats were implanted with electrodes into the medial forebrain bundle and the left and right somatosensory cortices for reward and cues. Among them, thirteen rats discriminated between the left and right somatosensory stimulations to obtain rewards. They were trained to learn ipsilateral turning response to the stimulation of the left or right somatosensory cortex in either the T-maze (Group T) or the E| maze (Group W). Performance was measured by the navigation speed in the mazes. Performances of rats in Group T were enhanced faster than those in Group W. A significant correlation between performances during training and performance in final testing was observed in Group T starting with the fifth training session while such a correlation was not observed in Group W until the tenth training session. The training mazes did not however affect the performances in the final test. These results suggest that a simple maze is better than a complicated maze for training animals to learn directions and direct cortical stimulation can be used as a cue for direction training. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  19. Modulation of Itch by Conditioning Itch and Pain Stimulation in Healthy Humans.

    Science.gov (United States)

    Andersen, Hjalte H; van Laarhoven, Antoinette I M; Elberling, Jesper; Arendt-Nielsen, Lars

    2017-12-01

    Little is known about endogenous descending control of itch. In chronic pain, descending pain inhibition is reduced as signified by lowered conditioned pain modulation. There are indications that patients with chronic itch may also exhibit reduced endogenous descending inhibition of itch and pain. This study aimed to investigate whether and the extent to which itch can be modulated by conditioning itch and pain stimuli. Twenty-six healthy volunteers participated. The study consisted of 5 conditions designed to systematically assess endogenous modulation of itch or pain: 1) itch-induced modulation of contralateral itch, 2) pain-induced modulation of contralateral itch, 3) pain-induced modulation of ipsilateral itch, 4) pain-induced modulation of contralateral pain, and 5) itch-induced modulation of contralateral pain. Conditioning stimuli were cold pressor-induced pain and histamine-evoked itch, whereas the test stimuli were electrical stimulation paradigms designed to evoke itch or pain. Pain was significantly reduced (conditioned pain modulation-effect) by the conditioning pain stimulus (P modulation-effect) by contra- as well as ipsilateral applied conditioning pain (both P modulation of itch as well as pain in humans. Future studies addressing potential aberrations in pain-evoked descending modulation of itch in chronic itch patients are warranted. Copyright © 2017 American Pain Society. Published by Elsevier Inc. All rights reserved.

  20. G-quadruplexes Significantly Stimulate Pif1 Helicase-catalyzed Duplex DNA Unwinding*

    Science.gov (United States)

    Duan, Xiao-Lei; Liu, Na-Nv; Yang, Yan-Tao; Li, Hai-Hong; Li, Ming; Dou, Shuo-Xing; Xi, Xu-Guang

    2015-01-01

    The evolutionarily conserved G-quadruplexes (G4s) are faithfully inherited and serve a variety of cellular functions such as telomere maintenance, gene regulation, DNA replication initiation, and epigenetic regulation. Different from the Watson-Crick base-pairing found in duplex DNA, G4s are formed via Hoogsteen base pairing and are very stable and compact DNA structures. Failure of untangling them in the cell impedes DNA-based transactions and leads to genome instability. Cells have evolved highly specific helicases to resolve G4 structures. We used a recombinant nuclear form of Saccharomyces cerevisiae Pif1 to characterize Pif1-mediated DNA unwinding with a substrate mimicking an ongoing lagging strand synthesis stalled by G4s, which resembles a replication origin and a G4-structured flap in Okazaki fragment maturation. We find that the presence of G4 may greatly stimulate the Pif1 helicase to unwind duplex DNA. Further studies reveal that this stimulation results from G4-enhanced Pif1 dimerization, which is required for duplex DNA unwinding. This finding provides new insights into the properties and functions of G4s. We discuss the observed activation phenomenon in relation to the possible regulatory role of G4s in the rapid rescue of the stalled lagging strand synthesis by helping the replicator recognize and activate the replication origin as well as by quickly removing the G4-structured flap during Okazaki fragment maturation. PMID:25627683

  1. Growth of AlGaN under the conditions of significant gallium evaporation: phase separation and enhanced lateral growth

    OpenAIRE

    Mayboroda, I. O.; Knizhnik, A. A.; Grishchenko, Yu. V.; Ezubchenko, I. S.; Zanaveskin, Maxim L.; Presniakov, M. Yu.; Potapkin, B. V.; Ilyin, V. A.

    2017-01-01

    Growth kinetics of AlGaN in NH3 MBE under significant Ga desorption was studied. It was found that the addition of gallium stimulates 2D growth and provides better morphology of films compared to pure AlN. The effect was experimentally observed at up to 98% desorption of the impinging gallium. We found that, under the conditions of significant thermal desorption, larger amounts of gallium were retained at lateral boundaries of 3D surface features than at flat terraces because of the higher bi...

  2. No significant effect of transcranial direct current stimulation (tDCS) found on simple motor reaction time comparing 15 different simulation protocols.

    Science.gov (United States)

    Horvath, Jared Cooney; Carter, Olivia; Forte, Jason D

    2016-10-01

    Research exploring the behavioral impact of transcranial direct current stimulation (tDCS) over M1 has produced homogenous results. The most common explanations to address this homogeneity concerns the differential impact of varied tDCS parameters (such as stimulation intensity or electrode montage). To explore this, we systematically examined the effects of 15 different tDCS protocols on a well-elucidated neurobehavioral system: simple visual motor reaction time (smRT). For the initial phase of this study, 150 healthy participants were randomly assigned to one of 5 experimental groups (2mA anodal, 2mA cathodal, 1mA anodal, 1mA cathodal, or sham) across 3 different conditions (orbitofrontal, bilateral, or extracephalic reference electrode location). The active electrode was always placed over M1 and tDCS lasted for 20min. Starting ~5min prior to stimulation and running continuously for ~30min, participants were repeatedly presented with a visual cue centered on a computer monitor and asked to press a response button as quickly as possible at stimulus onset (stimuli number: 100 pre-, 400 during-, and 100-post stimulation - interstimulus interval: 1-3s). Ex-gaussian distribution curves, miss, and error rates were determined for each normalized batch of 100 RTs and compared using a two-way ANOVA. As the largest group differences were seen with 2mA anodal (compared to sham) stimulation using an orbitofrontal montage, an additional 60 healthy participants were recruited to further test for significance in this condition. No significant impact of tDCS was seen on any parameter of smRT distribution, error rate, or miss rate, regardless of polarity, stimulation intensity, electrode montage, or stimulation-to-task relationship. Our results suggest that tDCS over M1 might not have a predictable or reliable effect on short duration smRT. Our results raise interesting questions regarding the mechanisms by which tDCS might modulate more complex motor behaviors. Additional

  3. Optical stimulation of the hearing and deaf cochlea under thermal and stress confinement condition

    Science.gov (United States)

    Schultz, M.; Baumhoff, P.; Kallweit, N.; Sato, M.; Krüger, A.; Ripken, T.; Lenarz, T.; Kral, A.

    2014-03-01

    There is a controversy, to which extend cochlear stimulation with near infrared laser pulses at a wavelength of 1860 nm is based on optoacoustic stimulation of intact hair cells or -in contrast- is based on direct stimulation of the nerve cells in absence of functional hair cells. Thermal and stress confinement conditions apply, because of the pulse duration range (5 ns, 10 μs-20 ms) of the two lasers used. The dependency of the signal characteristics on pulse peak power and pulse duration was investigated in this study. The compound action potential (CAP) was measured during stimulation of the cochlea of four anaesthetized guinea pigs, which were hearing at first and afterwards acutely deafened using intracochlear neomycin-rinsing. For comparison hydrophone measurements in a water tank were performed to investigate the optoacoustic signals at different laser interaction regimes. With rising pulse peak power CAPs of the hearing animals showed first a threshold, then a positively correlated and finally a saturating dependency. CAPs also showed distinct responses at laser onset and offset separated with the pulse duration. At pulse durations shorter than physiological response times the signals merged. Basically the same signal characteristics were observed in the optoacoustic hydrophone measurements, scaled with the sensitivity and response time of the hydrophone. Taking together the qualitative correspondence in the signal response and the absence of any CAPs in deafened animals our results speak in favor of an optoacoustic stimulation of intact hair cells rather than a direct stimulation of nerve cells.

  4. Evoked potentials after painful cutaneous electrical stimulation depict pain relief during a conditioned pain modulation.

    Science.gov (United States)

    Höffken, Oliver; Özgül, Özüm S; Enax-Krumova, Elena K; Tegenthoff, Martin; Maier, Christoph

    2017-08-29

    Conditioned pain modulation (CPM) evaluates the pain modulating effect of a noxious conditioning stimulus (CS) on another noxious test stimulus (TS), mostly based solely on subjective pain ratings. We used painful cutaneous electrical stimulation (PCES) to induce TS in a novel CPM-model. Additionally, to evaluate a more objective parameter, we recorded the corresponding changes of cortical evoked potentials (PCES-EP). We examined the CPM-effect in 17 healthy subjects in a randomized controlled cross-over design during immersion of the non-dominant hand into 10 °C or 24 °C cold water (CS). Using three custom-built concentric surface electrodes, electrical stimuli were applied on the dominant hand, inducing pain of 40-60 on NRS 0-100 (TS). At baseline, during and after CS we assessed the electrically induced pain intensity and electrically evoked potentials recorded over the central electrode (Cz). Only in the 10 °C-condition, both pain (52.6 ± 4.4 (baseline) vs. 30.3 ± 12.5 (during CS)) and amplitudes of PCES-EP (42.1 ± 13.4 μV (baseline) vs. 28.7 ± 10.5 μV (during CS)) attenuated during CS and recovered there after (all p pain ratings during electrical stimulation and amplitudes of PCES-EP correlated significantly with each other (r = 0.5) and with CS pain intensity (r = 0.5). PCES-EPs are a quantitative measure of pain relief, as changes in the electrophysiological response are paralleled by a consistent decrease in subjective pain ratings. This novel CPM paradigm is a feasible method, which could help to evaluate the function of the endogenous pain modulation processes. German Clinical Trials Register DRKS-ID: DRKS00012779 , retrospectively registered on 24 July 2017.

  5. Conditioned medium of dental pulp cells stimulated by Chinese propolis show neuroprotection and neurite extension in vitro.

    Science.gov (United States)

    Kudo, Daichi; Inden, Masatoshi; Sekine, Shin-Ichiro; Tamaoki, Naritaka; Iida, Kazuki; Naito, Eiji; Watanabe, Kazuhiro; Kamishina, Hiroaki; Shibata, Toshiyuki; Hozumi, Isao

    2015-03-04

    The purpose of this study was to clarify the effect of Chinese propolis on the expression level of neurotrophic factors in dental pulp cells (DPCs). We also investigated that the effects of the conditioned medium (CM) of DPCs stimulated by the propolis against oxidative and endoplasmic reticulum (ER) stresses in human neuroblastoma SH-SY5Y cells, and on neurite extensions in rat adrenal pheochromocytoma PC12 cells. To investigate the effect of the propolis on the levels of neurotrophic factors in DPCs, we performed a qRT-PCR experiment. As results, NGF, but not BDNF and NT-3, in DPCs was significantly elevated by the propolis in a concentration-dependent manner. H2O2-induced cell death was significantly inhibited by the treatment with the CM of DPCs. In addition, the treatment with the propolis-stimulated CM of DPCs had a more protective effect than that with the CM of DPCs. We also examine the effect of the propolis-stimulated CM of DPCs against a tunicamycin-induced ER stress. The treatment with the propolis-stimulated CM as well as the CM of DPCs significantly inhibited tunicamycin-induced cell death. Moreover, the treatment with the propolis-stimulated CM of DPCs significantly induced neurite outgrowth from PC12 cells than that with the CM of DPCs. These results suggest that the CM of DPCs as well as DPCs will be an efficient source of new treatments for neurodegenerative diseases and that the propolis promote the advantage of the CM of DPCs via producing neurotrophic factors. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. Significance of Operating Environment in Condition Monitoring of Large Civil Structures

    Directory of Open Access Journals (Sweden)

    Sreenivas Alampalli

    1999-01-01

    Full Text Available Success of remote long-term condition monitoring of large civil structures and developing calibrated analytical models for damage detection, depend significantly on establishing accurate baseline signatures and their sensitivity. Most studies reported in the literature concentrated on the effect of structural damage on modal parameters without emphasis on reliability of modal parameters. Thus, a field bridge structure was studied for the significance of operating conditions in relation to baseline signatures. Results indicate that in practice, civil structures should be monitored for at least one full cycle of in-service environmental changes before establishing baselines for condition monitoring or calibrating finite-element models. Boundary conditions deserve special attention.

  7. Significance of Operating Environment in Condition Monitoring of Large Civil Structures

    OpenAIRE

    Alampalli, Sreenivas

    1999-01-01

    Success of remote long-term condition monitoring of large civil structures and developing calibrated analytical models for damage detection, depend significantly on establishing accurate baseline signatures and their sensitivity. Most studies reported in the literature concentrated on the effect of structural damage on modal parameters without emphasis on reliability of modal parameters. Thus, a field bridge structure was studied for the significance of operating conditions in relation to bas...

  8. Psychological Strategy to stimulate the training of labor competitions in students of Psychology, in university conditions.

    Directory of Open Access Journals (Sweden)

    Yadira Rodríguez Faría

    2012-06-01

    Full Text Available The present investigation proposes a psychological strategy to stimulate the training of labor competitions in students of Psychology in semi presence conditions based upon an educative necessity diagnosis felt by students and their potentialities and the educative context. ANSE Model was the main technique for the diagnosis, using specifically the Central Group, Research of problems and Nominal Group, besides observation, were used no structural interviews, revision of documents, and content analysis. The psychological strategy was validated by means of the Expert Criteria Method. The system of actions created were the based for the training process of labor competitions in students of psychology in semi presence conditions with the professor labor.

  9. Optimum conditions for producing Cs2 molecular condensates by stimulated Raman adiabatic passage

    International Nuclear Information System (INIS)

    Feng Zhifang; Li Weidong; Wang Lirong; Xiao Liantuan; Jia Suotang

    2009-01-01

    The optimum conditions for producing Cs 2 molecular condensates from Cs atomic condensates with high transfer efficiency by stimulated Raman adiabatic passage are presented. Under the extended 'two-photon' resonance condition, including the two-photon process, the mean-field correction, and the tunneling coupling between two upper excited molecular levels, a high and stable conversion efficiency is realized. The high conversion efficiency could be achieved by following two methods under experimentally less demanding conditions (relatively small effective Rabi frequency for pump laser pulse). One is adjusting the detuning difference between two laser pulses for same effective Rabi frequencies with up to 87.2% transfer efficiency. Another one is adjusting the effective Rabi frequency, the detuning of dump laser for given effective Rabi frequency, and the detuning of pump laser with up to 80.7% transfer efficiency.

  10. Optimum conditions for producing Cs2 molecular condensates by stimulated Raman adiabatic passage

    Science.gov (United States)

    Feng, Zhifang; Li, Weidong; Wang, Lirong; Xiao, Liantuan; Jia, Suotang

    2009-10-01

    The optimum conditions for producing Cs2 molecular condensates from Cs atomic condensates with high transfer efficiency by stimulated Raman adiabatic passage are presented. Under the extended “two-photon” resonance condition, including the two-photon process, the mean-field correction, and the tunneling coupling between two upper excited molecular levels, a high and stable conversion efficiency is realized. The high conversion efficiency could be achieved by following two methods under experimentally less demanding conditions (relatively small effective Rabi frequency for pump laser pulse). One is adjusting the detuning difference between two laser pulses for same effective Rabi frequencies with up to 87.2% transfer efficiency. Another one is adjusting the effective Rabi frequency, the detuning of dump laser for given effective Rabi frequency, and the detuning of pump laser with up to 80.7% transfer efficiency.

  11. Does transcutaneous electrical nerve stimulation (TENS have a clinically relevant analgesic effect on different pain conditions? A literature review

    Directory of Open Access Journals (Sweden)

    Asami Naka

    2013-07-01

    Full Text Available Transcutaneous electric nerve stimulation (TENS is a standard therapy used in different painful conditions such as low back pain, diabetic polyneuropathy or arthrosis. However, literature reviews focusing on the effects and the clinical implication of this method in various painful conditions are yet scarce. The purpose of this literature research was to determine, whether TENS provides an analgesic effect on common painful conditions in clinical practice. Literature research was performed using three data bases (Pubmed, Embase, Cochrane Database, focusing on papers published in the space of time from 2007 to 2012. Papers were evaluated from two reviewers independently concerning the clinical outcome, taking account for the level of external evidence according to the German Cochrane levels of evidence (Ia – IV. 133 papers of varying methodological quality dealing with different painful conditions were selected in total. A clinically relevant analgesic effect was described in 90 painful conditions (67%. In 30 painful states (22%, the outcome was inconclusive due to the study design. No significant analgesic effect of TENS was observed in 15 painful conditions (11%. The vast majority of the papers were classified as Cochrane evidence level Ib (n = 64; 48%, followed by level Ia (n = 23; 17%, level III (n = 18; 14%, level IV (n = 15; 11%, level IIb (n = 10; 8% and level IIa (n = 3; 2%. Most of the studies revealed an analgesic effect in various painful conditions, confirming the usefulness of TENS in clinical practice.

  12. TNF-{alpha} mediates the stimulation of sclerostin expression in an estrogen-deficient condition

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Beom-Jun [Division of Endocrinology and Metabolism, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnap2-Dong, Seoul (Korea, Republic of); Bae, Sung Jin [Health Promotion Center, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnap2-Dong, Seoul (Korea, Republic of); Lee, Sun-Young; Lee, Young-Sun; Baek, Ji-Eun; Park, Sook-Young [Asan Institute for Life Sciences, 388-1 Poongnap2-Dong, Seoul (Korea, Republic of); Lee, Seung Hun [Division of Endocrinology and Metabolism, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnap2-Dong, Seoul (Korea, Republic of); Koh, Jung-Min, E-mail: jmkoh@amc.seoul.kr [Division of Endocrinology and Metabolism, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnap2-Dong, Seoul (Korea, Republic of); Kim, Ghi Su [Division of Endocrinology and Metabolism, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnap2-Dong, Seoul (Korea, Republic of)

    2012-07-20

    nude mice and sham-operated nude mice. In conclusion, these results suggest that TNF-{alpha} originating from T cells may be at least in part responsible for stimulating the sclerostin expression observed in an estrogen-deficient condition.

  13. TNF-α mediates the stimulation of sclerostin expression in an estrogen-deficient condition

    International Nuclear Information System (INIS)

    Kim, Beom-Jun; Bae, Sung Jin; Lee, Sun-Young; Lee, Young-Sun; Baek, Ji-Eun; Park, Sook-Young; Lee, Seung Hun; Koh, Jung-Min; Kim, Ghi Su

    2012-01-01

    responsible for stimulating the sclerostin expression observed in an estrogen-deficient condition.

  14. Identification of key factors in Accelerated Low Water Corrosion through experimental simulation of tidal conditions: influence of stimulated indigenous microbiota

    NARCIS (Netherlands)

    Marty, F.; Gueuné, H.; Malard, E.; Sánchez-Amaya, J.M.; Sjögren, L.; Abbas, B.; Quillet, L.; van Loosdrecht, M.C.M.; Muyzer, G.

    2014-01-01

    Biotic and abiotic factors favoring Accelerated Low Water Corrosion (ALWC) on harbor steel structures remain unclear warranting their study under controlled experimental tidal conditions. Initial stimulation of marine microbial consortia by a pulse of organic matter resulted in localized corrosion

  15. Annexin A1 N-terminal derived peptide Ac2-26 stimulates fibroblast migration in high glucose conditions.

    Directory of Open Access Journals (Sweden)

    Valentina Bizzarro

    Full Text Available Deficient wound healing in diabetic patients is very frequent, but the cellular and molecular causes are poorly defined. In this study, we have evaluated whether Annexin A1 derived peptide Ac2-26 stimulates fibroblast migration in high glucose conditions. Using normal human skin fibroblasts WS1 in low glucose (LG or high glucose (HG we observed the enrichment of Annexin A1 protein at cell movement structures like lamellipodial extrusions and interestingly, a significant decrease in levels of the protein in HG conditions. The analysis of the translocation of Annexin A1 to cell membrane showed lower levels of Annexin A1 in both membrane pool and supernatants of WS1 cells treated with HG. Wound-healing assays using cell line transfected with Annexin A1 siRNAs indicated a slowing down in migration speed of cells suggesting that Annexin A1 has a role in the migration of WS1 cells. In order to analyze the role of extracellular Annexin A1 in cell migration, we have performed wound-healing assays using Ac2-26 showing that peptide was able to increase fibroblast cell migration in HG conditions. Experiments on the mobilization of intracellular calcium and analysis of p-ERK expression confirmed the activity of the FPR1 following stimulation with the peptide Ac2-26. A wound-healing assay on WS1 cells in the presence of the FPR agonist fMLP, of the FPR antagonist CsH and in the presence of Ac2-26 indicated that Annexin A1 influences fibroblast cell migration under HG conditions acting through FPR receptors whose expression was slightly increased in HG. In conclusion, these data demonstrate that (i Annexin A1 is involved in migration of WS1 cells, through interaction with FPRs; (ii N- terminal peptide of Annexin A1 Ac2-26 is able to stimulate direct migration of WS1 cells in high glucose treatment possibly due to the increased receptor expression observed in hyperglycemia conditions.

  16. Design retrofit to prevent damage due to heat transport pump operation under conditions of significant void

    International Nuclear Information System (INIS)

    Lam, K.F.

    1991-01-01

    The purpose of this paper is to provide a general review of certain key design areas which address the safety concerns of HT pump operation under conditions of significant void. To illustrate the challenges confronting designers and analysts, some of the highlights during the design of a protective system to prevent damage to HT piping and pump supports at Bruce NGS 'A' are outlined. The effects of this protective system on reactor safety are also discussed. HI pump operation under conditions of significant void offers a major challenge to designers and analysts to ensure that pump induced vibration and its effects on pump and piping are addressed. For an in-service station the search for a practical solution is often limited by existing. station equipment design and Layout. The diversity of design verification process requires a major commitment of engineering resources to ensure all. safety aspects meet the requirements of regulatory body. Work currently undertaken at Ontario Hydro Research Pump Test Complex on two-phase flow in pumps and piping may provide better prediction of vibration characteristics so that inherent conservativeness in fatigue Life prediction of HI system components can be reduced

  17. Design retrofit to prevent damage due to heat transport pump operation under conditions of significant void

    Energy Technology Data Exchange (ETDEWEB)

    Lam, K F [Bruce Engineering Department, In-Service Nuclear Projects, Ontario Hydro, North York, ON (Canada)

    1991-04-01

    The purpose of this paper is to provide a general review of certain key design areas which address the safety concerns of HT pump operation under conditions of significant void. To illustrate the challenges confronting designers and analysts, some of the highlights during the design of a protective system to prevent damage to HT piping and pump supports at Bruce NGS 'A' are outlined. The effects of this protective system on reactor safety are also discussed. HI pump operation under conditions of significant void offers a major challenge to designers and analysts to ensure that pump induced vibration and its effects on pump and piping are addressed. For an in-service station the search for a practical solution is often limited by existing. station equipment design and Layout. The diversity of design verification process requires a major commitment of engineering resources to ensure all. safety aspects meet the requirements of regulatory body. Work currently undertaken at Ontario Hydro Research Pump Test Complex on two-phase flow in pumps and piping may provide better prediction of vibration characteristics so that inherent conservativeness in fatigue Life prediction of HI system components can be reduced.

  18. Enhancement of delay eyelid conditioning by microcurrent electrical stimulation of the medial prefrontal cortex is triggered by the expression of Fos protein in guinea pigs.

    Science.gov (United States)

    Zheng, Ya-Juan; Dong, Yu-Chen; Zhu, Chao; Zhao, Mei-Sheng

    2016-03-01

    Eyelid conditioning, including delay eyelid conditioning and trace eyelid conditioning, has been used extensively to study neural structures and mechanisms of learning and memory as a form of associative learning. In the present study, microcurrent electrical stimulation was used to stimulate the medial prefrontal cortex (mPFC) to induce delay eyelid conditioning in guinea pigs. The acquisition rate and relative latency of the conditioned eyelid response (CR) and the startle eyelid response (SR) were analyzed. The mPFC sites in the guinea pigs were examined under a light microscope following Nissl staining. In addition, the expression of Fos protein in neurons was detected using immunohistochemistry and western blot analysis. The results indicated that the acquisition rates of CR and SR were increased significantly (Pmicrocurrent electrical stimulation of the mPFC in guinea pigs was triggered by the expression of Fos protein. The observations of the present study further expand the understanding of conditioned reflexes and may aid future investigations into the formation of eyelid conditioning and the mechanisms underlying the circuit in various conditions.

  19. Carbon Mineralization Can Be Sustained or Even Stimulated under Fluctuating Redox Conditions in Tropical and Temperate Soils

    Science.gov (United States)

    Huang, W.; Hall, S. J.

    2017-12-01

    Soil carbon (C) mineralization is widely thought to be affected by O2 availability, and anaerobiosis represents a significant global mechanism of C stabilization. However, mineral-associated organic C (e.g. Fe-bound organic C) may be vulnerable to redox fluctuations due to release following Fe reduction, which could counteract protective effects of anaerobiosis. Many soils, including temperate Mollisols and tropical Oxisols, experience fluctuating redox conditions following moisture variations that could impact C cycling and stabilization. Here we incubated two soils with C4 leaf litter at different duration and frequencies of anaerobic periods for 128 days to investigate how redox fluctuations affect soil C mineralization. The treatments included static aerobic (control), and 2-, 4-, 8- and 12- day anaerobic followed by 4-day aerobic. We measured CO2, CH4, and their C isotope ratios. Longer durations of anaerobic conditions promoted greater Fe reduction and more DOC released. Notably, in both soils despite their large differences in composition, the production of CO2 and CH4 was stimulated under aerobic conditions following anaerobic conditions (relative to the control), which compensated for the decrease under anaerobic conditions. After 128 days, cumulative C mineralization in the control was similar between the Mollisol (9.7 mg C g-1) and the Oxisol (10.1 mg C g-1). The value in the Mollisol was significantly higher in the 12-day anaerobic treatment (11.2 mg C g-1) than the aerobic control and the 2-day anaerobic treatment (9.7 mg C g-1). In the Oxisol, cumulative C mineralization was not significantly affected by any of the fluctuating redox treatments relative to the control. Our findings challenge theory by showing that redox fluctuations can counteract the suppressive effects of O2 limitation on decomposition.

  20. Vagus nerve stimulation enhances extinction of conditioned fear and modulates plasticity in the pathway from the infralimbic prefrontal cortex to the amygdala.

    Directory of Open Access Journals (Sweden)

    David Frausto Peña

    2014-09-01

    Full Text Available Fearful experiences can produce long-lasting and debilitating memories. Extinction of the fear response requires consolidation of new memories that compete with fearful associations. Subjects with posttraumatic stress disorder (PTSD show impaired extinction of conditioned fear, which is associated with decreased ventromedial prefrontal cortex (vmPFC control over amygdala activity. Vagus nerve stimulation (VNS enhances memory consolidation in both rats and humans, and pairing VNS with exposure to conditioned cues enhances the consolidation of extinction learning in rats. Here we investigated whether pairing VNS with extinction learning facilitates plasticity between the infralimbic (IL medial prefrontal cortex and the basolateral complex of the amygdala (BLA. Rats were trained on an auditory fear conditioning task, which was followed by a retention test and one day of extinction training. Vagus nerve stimulation or sham-stimulation was administered concurrently with exposure to the fear-conditioned stimulus and retention of fear conditioning was tested again 24 hours later. VNS-treated rats demonstrated a significant reduction in freezing after a single extinction training session similar to animals that received 5x the number of extinction pairings. To study plasticity in the IL-BLA pathway, we recorded evoked field potentials in the BLA in anesthetized animals 24 h after retention testing. Brief burst stimulation in the IL produced LTD in the BLA field response in fear-conditioned and sham-treated animals. In contrast, the same stimulation resulted in potentiation of the IL-BLA pathway in the VNS-treated group. The present findings suggest that VNS promotes plasticity in the IL-BLA pathway to facilitate extinction of conditioned fear responses.

  1. Risk-Significant Adverse Condition Awareness Strengthens Assurance of Fault Management Systems

    Science.gov (United States)

    Fitz, Rhonda

    2017-01-01

    As spaceflight systems increase in complexity, Fault Management (FM) systems are ranked high in risk-based assessment of software criticality, emphasizing the importance of establishing highly competent domain expertise to provide assurance. Adverse conditions (ACs) and specific vulnerabilities encountered by safety- and mission-critical software systems have been identified through efforts to reduce the risk posture of software-intensive NASA missions. Acknowledgement of potential off-nominal conditions and analysis to determine software system resiliency are important aspects of hazard analysis and FM. A key component of assuring FM is an assessment of how well software addresses susceptibility to failure through consideration of ACs. Focus on significant risk predicted through experienced analysis conducted at the NASA Independent Verification Validation (IVV) Program enables the scoping of effective assurance strategies with regard to overall asset protection of complex spaceflight as well as ground systems. Research efforts sponsored by NASA's Office of Safety and Mission Assurance defined terminology, categorized data fields, and designed a baseline repository that centralizes and compiles a comprehensive listing of ACs and correlated data relevant across many NASA missions. This prototype tool helps projects improve analysis by tracking ACs and allowing queries based on project, mission type, domaincomponent, causal fault, and other key characteristics. Vulnerability in off-nominal situations, architectural design weaknesses, and unexpected or undesirable system behaviors in reaction to faults are curtailed with the awareness of ACs and risk-significant scenarios modeled for analysts through this database. Integration within the Enterprise Architecture at NASA IVV enables interfacing with other tools and datasets, technical support, and accessibility across the Agency. This paper discusses the development of an improved workflow process utilizing this

  2. State Policy of Stimulation of Industrial Competitiveness under Conditions of Economic Integration

    Directory of Open Access Journals (Sweden)

    Kovalchuk Viacheslav H.

    2014-03-01

    Full Text Available The article is devoted to problems of state regulatory policy of stimulation of economic growth, increase of efficiency of activity of industrial branches of the country. It considers examples of foreign experience in the part of state support of domestic manufacturers. It shows possible variants of integration of co-operation between CIS countries on the basis of specialisation, co-operation and joint activity for achieving economic growth of economies. It demonstrates an automated system of mass servicing of customers, which is offered to be used in the structure of associations of trade enterprises. It offers ways of achievement of competitive advantages of domestic enterprises under conditions of globalisation by means of introduction of clusters of the consumer market enterprises. The article reveals their shortcomings and possibilities of development in the territory of Ukraine under conditions of limited financial resources. It acknowledges that measures of the fiscal policy should be directed, first of all, at support of creation of associations of medium enterprises of the light and other branches of industry and agriculture, which have development potential. It identifies main elements of creation of state programmes of support and development of the cluster form of organisation of the light and other branches of industry, agriculture and trade.

  3. The significance of the pilot conditioning plant (PKA) for spent fuel management

    International Nuclear Information System (INIS)

    Willax, H.O.

    1996-01-01

    The pilot conditioning plant (PKA) is intended as a multi-purpose facility and thus may serve various purposes involved in the conditioning or disposal of spent fuel elements or radwaste. Its design as a pilot plant permits development and trial of various methods and processes for fuel element conditioning, as well as for radwaste conditioning. (orig./DG) [de

  4. Social participation and healthy ageing: a neglected, significant protective factor for chronic non communicable conditions

    Directory of Open Access Journals (Sweden)

    Joseph Jennifer

    2011-10-01

    Full Text Available Abstract Background Low and middle income countries are ageing at a much faster rate than richer countries, especially in Asia. This is happening at a time of globalisation, migration, urbanisation, and smaller families. Older people make significant contributions to their families and communities, but this is often undermined by chronic disease and preventable disability. Social participation can help to protect against morbidity and mortality. We argue that social participation deserves much greater attention as a protective factor, and that older people can play a useful role in the prevention and management of chronic conditions. We present, as an example, a low-cost, sustainable strategy that has increased social participation among elders in Sri Lanka. Discussion Current international policy initiatives to address the increasing prevalence of non-communicable chronic diseases are focused on cardiovascular disease, diabetes, respiratory disease and cancers, responsible for much premature mortality. Interventions to modify their shared risk factors of high salt and fat diets, inactivity, smoking and alcohol use are advocated. But older people also suffer chronic conditions that primarily affect quality of life, and have a wider range of risk factors. There is strong epidemiological and physiological evidence that social isolation, in particular, is as important a risk factor for chronic diseases as the 'lifestyle' risk factors, yet it is currently neglected. There are useful experiences of inexpensive and sustainable strategies to improve social participation among older people in low and lower middle income countries. Our experience with forming Elders' Clubs with retired tea estate workers in Sri Lanka suggests many benefits, including social support and participation, inter-generational contact, a collective voice, and facilitated access to health promotion activities, and to health care and social welfare services. Summary Policies to

  5. Heat storage in forest biomass significantly improves energy balance closure particularly during stable conditions

    Science.gov (United States)

    Lindroth, A.; Mölder, M.; Lagergren, F.

    2009-08-01

    Temperature measurements in trunks and branches in a mature ca. 100 years-old mixed pine and spruce forest in central Sweden were used to estimate the heat storage in the tree biomass. The estimated heat flux in the sample trees and data on biomass distributions were used to scale up to stand level biomass heat fluxes. The rate of change of sensible and latent heat storage in the air layer below the level of the flux measurements was estimated from air temperature and humidity profile measurements and soil heat flux was estimated from heat flux plates and soil temperature measurements. The fluxes of sensible and latent heat from the forest were measured with an eddy covariance system in a tower. The analysis was made for a two-month period in summer of 1995. The tree biomass heat flux was the largest of the estimated storage components and varied between 40 and -35 W m-2 on summer days with nice weather. Averaged over two months the diurnal maximum of total heat storage was 45 W m-2 and the minimum was -35 W m-2. The soil heat flux and the sensible heat storage in air were out of phase with the biomass flux and they reached maximum values that were about 75% of the maximum of the tree biomass heat storage. The energy balance closure improved significantly when the total heat storage was added to the turbulent fluxes. The slope of a regression line with sum of fluxes and storage as independent and net radiation as dependent variable, increased from 0.86 to 0.95 for half-hourly data and the scatter was also reduced. The most significant finding was, however, that during nights with strongly stable conditions when the sensible heat flux dropped to nearly zero, the total storage matched the net radiation nearly perfectly. Another interesting result was that the mean energy imbalance started to increase when the Richardson number became more negative than ca. -0.1. In fact, the largest energy deficit occurred at maximum instability. Our conclusion is that eddy

  6. Statistical significant changes in ground thermal conditions of alpine Austria during the last decade

    Science.gov (United States)

    Kellerer-Pirklbauer, Andreas

    2016-04-01

    Longer data series (e.g. >10 a) of ground temperatures in alpine regions are helpful to improve the understanding regarding the effects of present climate change on distribution and thermal characteristics of seasonal frost- and permafrost-affected areas. Beginning in 2004 - and more intensively since 2006 - a permafrost and seasonal frost monitoring network was established in Central and Eastern Austria by the University of Graz. This network consists of c.60 ground temperature (surface and near-surface) monitoring sites which are located at 1922-3002 m a.s.l., at latitude 46°55'-47°22'N and at longitude 12°44'-14°41'E. These data allow conclusions about general ground thermal conditions, potential permafrost occurrence, trend during the observation period, and regional pattern of changes. Calculations and analyses of several different temperature-related parameters were accomplished. At an annual scale a region-wide statistical significant warming during the observation period was revealed by e.g. an increase in mean annual temperature values (mean, maximum) or the significant lowering of the surface frost number (F+). At a seasonal scale no significant trend of any temperature-related parameter was in most cases revealed for spring (MAM) and autumn (SON). Winter (DJF) shows only a weak warming. In contrast, the summer (JJA) season reveals in general a significant warming as confirmed by several different temperature-related parameters such as e.g. mean seasonal temperature, number of thawing degree days, number of freezing degree days, or days without night frost. On a monthly basis August shows the statistically most robust and strongest warming of all months, although regional differences occur. Despite the fact that the general ground temperature warming during the last decade is confirmed by the field data in the study region, complications in trend analyses arise by temperature anomalies (e.g. warm winter 2006/07) or substantial variations in the winter

  7. DETERMINATION OF MOST SIGNIFICANT FACTORS FOR ANALYSIS OF HIGHWAY OPERATING CONDITIONS

    Directory of Open Access Journals (Sweden)

    M. G. Solodkaya

    2017-01-01

    Full Text Available Traffic circulation on highways is a random process. Therefore automotive damage rate and, respectively, roads on which they are moving is subjected to regularities of random processes. Dynamic processes of vehicle-road interaction are determined to various extents by a host of factors that include road pavement evenness and characteristics of moving vehicles. For this reason the following task has been set: to reveal the most significant factors and mathematically correlate values of vehicle dynamic loads with a quality of road pavement and vehicle speed. Such task statement has not been solved adequately and this situation determines importance and novelty of the investigations in the given direction. While solving the mentioned task the investigations which have been carried out under real-life conditions and with the help of real-life objects are considered as the most reliable ones. However, preparation and execution of such experiments as needed significantly complicates their implementation. In this regard it looks rather expediential to combine a factorial experiment with the tests of a checked model while using ECM with stage-by-stage parameter fixation of working processes passing in “vehicle-road” system, comprehensive assessment pertaining to influence of the selected factors and selection of their optimum combination. Mathematical dependence has been obtained to evaluate influence of several external factors on optimization of vehicle dynamic load on the road. This component makes it possible to attain a simplified and adequate description of element interaction in “vehicle – road” system. While investigating influence of pavement irregularities on maximum dynamic loads on the road influence rate of the selected factors is determined in the following sequence: vehicle weight, pavement evenness and speed of transport facility.

  8. Insulin signaling in various equine tissues under basal conditions and acute stimulation by intravenously injected insulin.

    Science.gov (United States)

    Warnken, Tobias; Brehm, Ralph; Feige, Karsten; Huber, Korinna

    2017-10-01

    The aim of the study was to analyze key proteins of the equine insulin signaling cascade and their extent of phosphorylation in biopsies from muscle tissue (MT), liver tissue (LT), and nuchal AT, subcutaneous AT, and retroperitoneal adipose tissues. This was investigated under unstimulated (B1) and intravenously insulin stimulated (B2) conditions, which were achieved by injection of insulin (0.1 IU/kg bodyweight) and glucose (150 mg/kg bodyweight). Twelve warmblood horses aged 15 ± 6.8 yr (yr), weighing 559 ± 79 kg, and with a mean body condition score of 4.7 ± 1.5 were included in the study. Key proteins of the insulin signaling cascade were semiquantitatively determined using Western blotting. Furthermore, modulation of the cascade was assessed. The basal expression of the proteins was only slightly influenced during the experimental period. Insulin induced a high extent of phosphorylation of insulin receptor in LT (P < 0.01) but not in MT. Protein kinase B and mechanistic target of rapamycin expressed a higher extent of phosphorylation in all tissues in B2 biopsies. Adenosine monophosphate protein kinase, as a component related to insulin signaling, expressed enhanced phosphorylation in MT (P < 0.05) and adipose tissues (nuchal AT P < 0.05; SCAT P < 0.01; retroperitoneal adipose tissue P < 0.05), but not in LT at B2. Tissue-specific variations in the acute response of insulin signaling to intravenously injected insulin were observed. In conclusion, insulin sensitivity in healthy horses is based on a complex concerted action of different tissues by their variations in the molecular response to insulin. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Studies on gene expressions analyses for Arabidopsis thaliana plants stimulated by space flight condition

    Science.gov (United States)

    Lu, Jinying; Liu, Min; Pan, Yi; Li, Huasheng

    We carried out whole-genome microarray to screen the transcript profile of Arabidopsis thaliana seedlings after three treatment: space microgravity condition( Seedlings grown in microgravity state of space flight of SIMBOX on Shenzhou-8), 1g centrifugal force in space(Seedlings grown in 1g centrifugal force state of space flight of SIMBOX on Shenzhou-8) and ground control. The result of microarray analysis is as followed: There were 368 genes significantly differentially expressed in space microgravity condition compared with that in 1g centrifuge space condition. Space radiation caused 246 genes significantly differentially expressed between seedlings in 1g centrifuge space condition and ground control. Space conditions (including microgravity and radiation) caused 621 genes significantly differentially expressed between seedlings in space microgravity condition and ground control. Microgravity and radiation as a single factor can cause plant gene expression change, but two factors synergism can produce some new effects on plant gene expression. The function of differential expression genes were analyst by bioinformatics, and we found the expression of genes related with stress were more different, such as the dehydration of protein (dehydrin Xero2) expression is up-regulated 57 times; low-temperature-induced protein expression is up-regulated in 49 times; heat shock protein expression is up-regulated 20 times; transcription factor DREB2A expression increase 25 times; protein phosphatase 2C expression is up-regulated 14 times; transcription factor NAM-like protein expression is up-regulated 13 times; cell wall metabolism related genes (xyloglucan, endo-1, 4-beta-D-glucanase) expression is down-regulated in 15 times. The results provide scientific data for the mechanism of space mutation.

  10. Electroconvulsive therapy in the treatment of neuropsychiatric conditions and transcranial magnetic stimulation as a pathophysiological probe in neuropsychiatry.

    Science.gov (United States)

    McDonald, W M; Greenberg, B D

    2000-01-01

    It is a challenging task to review transcranial magnetic stimulation (TMS) studies in neuropsychiatric disorders alongside assessments of longstanding clinical applications of ECT as an empirical treatment. The task is challenging because TMS was developed as a probe of neural mechanisms, whereas, in marked contrast, ECT has been a clinical technique from its inception. Since the onset of modern psychopharmacology, the understanding of the potential applications of ECT to neuropsychiatric disorders is generally restricted to case reports of patients with intractable disease that have had at least a partial response to ECT. Studies of the possible efficacy of TMS in neuropsychiatric conditions have a significant advantage over ECT as the treatments are associated with less morbidity. The only serious known complication in TMS is a risk of seizures that may increase in patients with neuropsychiatric conditions such as course brain disease. Only cortical structures are themselves accessible to TMS using current technology. Present TMS techniques, however, seem capable of affecting activity in deeper brain structures that are functionally linked to cortical brain regions. TMS permits novel explorations of relationships between regional brain activity and symptoms of a number of neuropsychiatric disorders, as well as in research relating activity in functionally related brain regions to modulation of cognition and affective states in healthy individuals. This is particularly true at present because TMS and powerful neuroimaging and neuropsychological tools are all making rapid advances simultaneously.

  11. Interference effects of transcranial direct current stimulation over the right frontal cortex and adrenergic system on conditioned fear.

    Science.gov (United States)

    Nasehi, Mohammad; Soltanpour, Reyhaneh; Ebrahimi-Ghiri, Mohaddeseh; Zarrabian, Shahram; Zarrindast, Mohammad-Reza

    2017-11-01

    The effects of pharmacological interventions on fear memory have widely been studied, but there are very few studies about the effects of brain electrical stimulation on fear memory function. Therefore, our aim was to determine whether anodal/cathodal transcranial direct current stimulation (tDCS) over the right frontal cortex would modify propranolol-induced contextual and auditory fear memory deficits, before or after training. The adult NMRI male mice were randomly assigned into three groups: the sham group, the anodal tDCS group, and the cathodal tDCS group. Fear memories were evaluated using a classical fear conditioning apparatus. While the anodal stimulation did not affect fear retrieval, post-training cathodal stimulation improved fear memory retrieval. Regardless of when propranolol (0.1 mg/kg) was administered, it impaired fear memory retrieval. However, when anodal stimulation and propranolol were applied prior to the training, contextual fear memory retrieval was increased and auditory fear memory was reversed. An enhanced contextual retrieval was also observed when propranolol was administered prior to the training and stimulation occurred after the training. Only when the stimulation occurred prior to the training and propranolol was administered after the training was there a selective improvement in contextual fear memory retrieval, leaving the auditory fear memory retrieval impaired. Interestingly, cathodal stimulation improved the effects of propranolol on auditory fear memory only when it occurred prior to the training. The results highlight possible improving effects for anodal/cathodal tDCS on propranolol-induced deficits on fear memories. The timing of the interventions related to the specific phases of memory formation is important in modulating fear behaviors.

  12. Conditioning stimulation techniques for enhancement of transcranially elicited evoked motor responses

    NARCIS (Netherlands)

    Journee, H. -L.; Polak, H. E.; De Kleuver, M.

    2007-01-01

    Introduction. - In spite of the use of multipulse, transcranial electrical stimulation (TES) is still insufficient in a subgroup of patients to elicit motor-evoked potentials during intraoperative neurophysiological monitoring (IONM). Classic facilitation methods used in awake patients are precluded

  13. A novel lumazine synthase molecule from Brucella significantly promotes the immune-stimulation effects of antigenic protein.

    Science.gov (United States)

    Du, Z Q; Wang, J Y

    2015-10-27

    Brucella, an intracellular parasite that infects some livestock and humans, can damage or destroy the reproductive system of livestock. The syndrome is referred to as brucellosis and often occurs in pastoral areas; it is contagious from livestock to humans. In this study, the intact Brucella suis outer membrane protein 31 (omp31) gene was cloned, recombinantly expressed, and examined as a subunit vaccine candidate. The intact Brucella lumazine synthase (bls) gene was cloned and recombinantly expressed to study polymerization function in vitro. Non-reducing gel electrophoresis showed that rBs-BLS existed in different forms in vitro, including as a dimer and a pentamer. An enzyme-linked immunosorbent assay result showed that rOmp31 protein could induce production of an antibody in rabbits. However, the rOmp31-BLS fusion protein could elicit a much higher antibody titer in rabbits; this construct involved fusion of the Omp31 molecule with the BLS molecule. Our results indicate that Omp31 is involved in immune stimulation, while BLS has a polymerizing function based on rOmp31-BLS fusion protein immunogenicity. These data suggest that Omp31 is an ideal subunit vaccine candidate and that the BLS molecule is a favorable transport vector for antigenic proteins.

  14. The autophagoproteasome a novel cell clearing organelle in baseline and stimulated conditions

    Directory of Open Access Journals (Sweden)

    Paola Lenzi

    2016-07-01

    Full Text Available Protein clearing pathways named autophagy (ATG and ubiquitin proteasome (UP control homeostasis within eukaryotic cells, while their dysfunction produces neurodegeneration. These pathways are viewed as distinct biochemical cascades occurring within specific cytosolic compartments owing pathway-specific enzymatic activity.Recent data strongly challenged the concept of two morphologically distinct and functionally segregated compartments. In fact, preliminary evidence suggests the convergence of these pathways to form a novel organelle named autophagoproteasome. This is characterized in the present study by using a cell line where, mTOR activity is upregulated and autophagy is suppressed. This was reversed dose-dependently by administering the mTOR inhibitor rapamycin. Thus, we could study autophagoproteasomes when autophagy was either suppressed or stimulated. The occurrence of autophagoproteasome was shown also in non-human cell lines. Ultrastructural morphometry, based on the stochiometric binding of immunogold particles allowed the quantitative evaluation of ATG and UP component within autophagoproteasomes. The number of autophagoproteasomes increases following mTOR inhibition. Similarly, mTOR inhibition produces overexpression of both LC3 and P20S particles. This is confirmed by the fact that the ratio of free vs autophagosome-bound LC3 is similar to that measured for P20S, both in baseline conditions and following mTOR inhibition. Remarkably, within autophagoproteasomes there is a slight prevalence of ATG compared with UP components for low rapamycin doses, whereas for higher rapamycin doses UP increases more than ATG. While LC3 is widely present within cytosol, UP is strongly polarized within autophagoproteasomes. These fine details were evident at electron microscopy but could not be deciphered by using confocal microscopy. Despite its morphological novelty autophagoproteasomes appear the natural site where clearing pathways (once believed

  15. The Autophagoproteasome a Novel Cell Clearing Organelle in Baseline and Stimulated Conditions.

    Science.gov (United States)

    Lenzi, Paola; Lazzeri, Gloria; Biagioni, Francesca; Busceti, Carla L; Gambardella, Stefano; Salvetti, Alessandra; Fornai, Francesco

    2016-01-01

    Protein clearing pathways named autophagy (ATG) and ubiquitin proteasome (UP) control homeostasis within eukaryotic cells, while their dysfunction produces neurodegeneration. These pathways are viewed as distinct biochemical cascades occurring within specific cytosolic compartments owing pathway-specific enzymatic activity. Recent data strongly challenged the concept of two morphologically distinct and functionally segregated compartments. In fact, preliminary evidence suggests the convergence of these pathways to form a novel organelle named autophagoproteasome. This is characterized in the present study by using a cell line where, mTOR activity is upregulated and autophagy is suppressed. This was reversed dose-dependently by administering the mTOR inhibitor rapamycin. Thus, we could study autophagoproteasomes when autophagy was either suppressed or stimulated. The occurrence of autophagoproteasome was shown also in non-human cell lines. Ultrastructural morphometry, based on the stochiometric binding of immunogold particles allowed the quantitative evaluation of ATG and UP component within autophagoproteasomes. The number of autophagoproteasomes increases following mTOR inhibition. Similarly, mTOR inhibition produces overexpression of both LC3 and P20S particles. This is confirmed by the fact that the ratio of free vs. autophagosome-bound LC3 is similar to that measured for P20S, both in baseline conditions and following mTOR inhibition. Remarkably, within autophagoproteasomes there is a slight prevalence of ATG compared with UP components for low rapamycin doses, whereas for higher rapamycin doses UP increases more than ATG. While LC3 is widely present within cytosol, UP is strongly polarized within autophagoproteasomes. These fine details were evident at electron microscopy but could not be deciphered by using confocal microscopy. Despite its morphological novelty autophagoproteasomes appear in the natural site where clearing pathways (once believed to be

  16. The significance of thermohydraulic conditions for the corrosion safety of PWR steam generators

    International Nuclear Information System (INIS)

    Gulich, J.F.

    1975-04-01

    In several PWR nuclear power plants leakages have occurred in the steam generator which were caused by localised corrosion attack. While the attention of manufacturers and operators is focused on the influences of feedwater chemistry and tube material, the present work highlights the fact that the damage always occurred in those places where flow regimed are poorly defined. The investigation leads to the result that local dry out of the heating surface can be contributing cause of damage. A method is indicated for estimating the thermohydraulic conditions in the inflow region over the tube plate and measures to improve corrosion safety are discussed. (author)

  17. Enhancement of delay eyelid conditioning by microcurrent electrical stimulation of the medial prefrontal cortex is triggered by the expression of Fos protein in guinea pigs

    OpenAIRE

    ZHENG, YA-JUAN; DONG, YU-CHEN; ZHU, CHAO; ZHAO, MEI-SHENG

    2016-01-01

    Eyelid conditioning, including delay eyelid conditioning and trace eyelid conditioning, has been used extensively to study neural structures and mechanisms of learning and memory as a form of associative learning. In the present study, microcurrent electrical stimulation was used to stimulate the medial prefrontal cortex (mPFC) to induce delay eyelid conditioning in guinea pigs. The acquisition rate and relative latency of the conditioned eyelid response (CR) and the startle eyelid response (...

  18. Deep brain stimulation affects conditioned and unconditioned anxiety in different brain areas

    NARCIS (Netherlands)

    van Dijk, A.; Klanker, M.; van Oorschot, N.; Post, R.; Hamelink, R.; Feenstra, M. G. P.; Denys, D.

    2013-01-01

    Deep brain stimulation (DBS) of the nucleus accumbens (NAc) has proven to be an effective treatment for therapy refractory obsessive compulsive disorder. Clinical observations show that anxiety symptoms decrease rapidly following DBS. As in clinical studies different regions are targeted, it is of

  19. High-pressure polymorphs in Yamato-790729 L6 chondrite and their significance for collisional conditions

    Science.gov (United States)

    Kato, Yukako; Sekine, Toshimori; Kayama, Masahiko; Miyahara, Masaaki; Yamaguchi, Akira

    2017-12-01

    Shock pressure recorded in Yamato (Y)-790729, classified as L6 type ordinary chondrite, was evaluated based on high-pressure polymorph assemblages and cathodoluminescence (CL) spectra of maskelynite. The host-rock of Y-790729 consists mainly of olivine, low-Ca pyroxene, plagioclase, metallic Fe-Ni, and iron-sulfide with minor amounts of phosphate and chromite. A shock-melt vein was observed in the hostrock. Ringwoodite, majorite, akimotoite, lingunite, tuite, and xieite occurred in and around the shock-melt vein. The shock pressure in the shock-melt vein is about 14-23 GPa based on the phase equilibrium diagrams of high-pressure polymorphs. Some plagioclase portions in the host-rock occurred as maskelynite. Sixteen different CL spectra of maskelynite portions were deconvolved using three assigned emission components (centered at 2.95, 3.26, and 3.88 eV). The intensity of emission component at 2.95 eV was selected as a calibrated barometer to estimate shock pressure, and the results indicate pressures of about 11-19 GPa. The difference in pressure between the shock-melt vein and host-rock might suggest heterogeneous shock conditions. Assuming an average shock pressure of 18 GPa, the impact velocity of the parent-body of Y-790729 is calculated to be 1.90 km s-1. The parent-body would be at least 10 km in size based on the incoherent formation mechanism of ringwoodite in Y-790729.

  20. Significance of proper oral hygiene for health condition of mouth and teeth

    Directory of Open Access Journals (Sweden)

    Ljaljević Agima

    2012-01-01

    Full Text Available Background/Aim. Proper mouth and teeth hygiene has influence on the prevention of a great number of diseases and very often some of them are not related only to oral cavity. Most frequent diseases of mouth and teeth such as caries and periodontal diseases are caused, among other factors, by poor oral hygiene. They are also more frequent in young population. The aim of this study was to estimate the influence of sociodemographic characteristics and hygienic habit on oral health in children aged 11-15 years. Methods. This crosssectional study was conducted by the dental teams in dentist surgeries in Tivat Health Center between May and September 2009. The sample consisted of patients 11 to 15 years of age. A questionnaire and dental examination of mouth and teeth were used as research instruments. The examinations were conducted in accordance with the World Health Organization methodology and criteria. The data obtained from the interviews were correlated with those obtained from the clinical examinations. Results. The results show that the majority of respondents brush their teeth twice a day and visit the dentist once in every six months. The research also shows that 57% respondents have caries of deciduous teeth and over 63% respondents of permanent teeth. Gingivitis was found in 14% and orthodontic anomalies in 44.7% respondents. A half of respondents who brush their teeth rarely have problems with gingivitis. There is a highly statistically significant difference between the occurrence of gingivitis and the frequency of teeth brushing. Conclusion. There is a significant difference between mouth and oral hygiene and sex as well as other sociodemographic characteristics of respondents. The study showed the correlation between occurrence of caries and the gingivitis and frequency of teeth brushing and dental visits.

  1. [Significance of proper oral hygiene for health condition of mouth and teeth].

    Science.gov (United States)

    Ljaljević, Agima; Matijević, Snezana; Terzić, Natasa; Andjelić, Jasmina; Mugosa, Boban

    2012-01-01

    Proper mouth and teeth hygiene has influence on the prevention of a great number of diseases and very often some of them are not related only to oral cavity. Most frequent diseases of mouth and teeth such as caries and periodontal diseases are caused, among other factors, by poor oral hygiene. They are also more frequent in young population. The aim of this study was to estimate the influence of sociodemographic characteristics and hygienic habit on oral health in children aged 11-15 years. This cross-sectional study was conducted by the dental teams in dentist surgeries in Tivat Health Center between May and September 2009. The sample consisted of patients 11 to 15 years of age. A questionnaire and dental examination of mouth and teeth were used as research instruments. The examinations were conducted in accordance with the World Health Organization methodology and criteria. The data obtained from the interviews were correlated with those obtained from the clinical examinations. The results show that the majority of respondents brush their teeth twice a day and visit the dentist once in every six months. The research also shows that 57% respondents have caries of deciduous teeth and over 63% respondents of permanent teeth. Gingivitis was found in 14% and orthodontic anomalies in 44.7% respondents. A half of respondents who brush their teeth rarely have problems with gingivitis. There is a highly statistically significant difference between the occurrence of gingivitis and the frequency of teeth brushing. There is a significant difference between mouth and oral hygiene and sex as well as other sociodemographic characteristics of respondents. The study showed the correlation between occurrence of caries and the gingivitis and frequency of teeth brushing and dental visits.

  2. Neuromodulation of conditioned placebo/nocebo in heat pain: anodal vs cathodal transcranial direct current stimulation to the right dorsolateral prefrontal cortex.

    Science.gov (United States)

    Egorova, Natalia; Yu, Rongjun; Kaur, Navneet; Vangel, Mark; Gollub, Randy L; Dougherty, Darin D; Kong, Jian; Camprodon, Joan A

    2015-07-01

    Placebo and nocebo play an important role in clinical practice and medical research. Modulating placebo/nocebo responses using noninvasive brain stimulation methods, such as transcranial direct current stimulation (tDCS), has the potential to harness these effects to therapeutic benefit in a clinical setting. In this study, we assessed the effect of anodal and cathodal tDCS over the right dorsolateral prefrontal cortex (rDLPFC) on conditioned placebo/nocebo cue response to heat pain. Two matched groups of healthy volunteers were subjected to an identical session of conditioning, during which low and high cues (abstract images) were associated with low and high pain levels, respectively. Twenty-minute 2-mA tDCS (either anodal or cathodal) over the rDLPFC was applied. The influence of tDCS current polarity (anodal vs cathodal) on placebo and nocebo was assessed, using subjects' pain ratings in response to identical pain preceded by the conditioned high or low cues. The duration of cue presentation varied to allow either fully conscious or subliminal processing. Significant placebo and nocebo effects in the anodal but not the cathodal group were elicited with the conditioning paradigm. This study provides evidence of a possibility to modulate the conditioned placebo and nocebo effect by changing the excitability of the rDLPFC using tDCS.

  3. Stimulation Of The Methane Production With The Use Of Changing Of The Rock Massif Physical Conditions

    Directory of Open Access Journals (Sweden)

    Baev Mikhail

    2017-01-01

    Full Text Available The commercial coalbed methane production success is majorly defined by the effectiveness of the use of special gas inflow stimulation methods. The necessity of using of such methods issubject to the aspects of searching and displacement of methane within the coal compound. Theanalysis of the ways of methane production stimulation from virgin coal formations is given. The description of the process of hydraulic fracturing (fracturing as the most common stimulation method during the commercial coalbed methane production as well as its major advantages are presented. The present work provides data about the initiated laboratory research of sands collected from Kemerovo region deposits for the purpose of finding of the most prospective samples by means of anchoring of fractures. The prospectivity and ability to implement the hydraulic fracturing with the use of locally available sands acting as proppants are shown. The influence of the strain-stress state of the rock massif on the alteration of permeability and the necessity of its extension study with respect to different technological features of hydraulic fracturing is shown

  4. Endocannabinergic modulation of interleukin-1β in mouse hippocampus under basal conditions and after in vivo systemic lipopolysaccharide stimulation.

    Science.gov (United States)

    Csölle, Cecília; Sperlágh, Beáta

    2011-01-01

    Cannabinoids play an important role in the suppression of proinflammatory cytokine production in the periphery and brain. In this study, we explored whether endogenous activation of cannabinoid (CB) 1 receptors (CB1Rs) affects interleukin (IL)-1β levels in the mouse hippocampus under basal conditions and following stimulation with in vivo bacterial lipopolysaccharide (LPS, 250 μg/kg i.p.). IL-1β levels were determined in the hippocampi of wild-type (WT), CB1R-/- and P2X₇ receptor (P2X₇R)-/- mice using an ELISA kit. Basal but not LPS-induced IL-1β levels were downregulated when CB1R function was abrogated by genetic deletion, suggesting that endocannabinoids contributed to basal IL-1β content in the mouse hippocampus. AM251 (3 mg/kg i.p.), an antagonist of CB1Rs, also inhibited basal IL-1β protein in WT but not in CB1R-/- mice. In the absence of P2X₇R, LPS-induced IL-1β production was lower, while the inhibitory effect of CB1R antagonists on basal IL-1β was significantly attenuated. The LPS-induced elevation in IL-1β production was decreased in the presence of AM251 and AM281, with no significant difference between WT and P2X₇R-/- mice. CB1Rs are responsible for the modulation of basal IL-1β levels in the hippocampus, while the effects of CB1 antagonists on systemic LPS-induced IL-1β concentrations are independent of CB1Rs. Copyright © 2011 S. Karger AG, Basel.

  5. Evidence for the involvement of a labile protein in stimulation of adrenal steroidogenesis under conditions not inhibitory to protein synthesis

    International Nuclear Information System (INIS)

    Krueger, R.J.; Orme-Johnson, N.R.

    1988-01-01

    Evidence is presented to support the hypothesis that synthesis of a labile protein is required for stimulation of steroidogenesis in rat adrenocortical cells. Amino acids L-canavanine and L-S-aminoethylcysteine, at concentrations as high as 5 mM, each inhibited steroidogenesis to a much greater extent than they inhibited protein synthesis. S-Aminoethylcysteine caused a 50% decrease in the stimulated rate of corticosterone production under conditions where incorporation of [35S]methionine into protein was unchanged. Both amino acids block stimulation of steroid synthesis at a step subsequent to the formation of cAMP and before the synthesis of progesterone. The onset of this effect, after the addition of the amino acids, on corticosterone production is quite rapid. These results provide support, that is not dependent on inhibition of protein synthesis, for the hypothesis that a labile protein mediates stimulation of steroidogenesis. Reversal of canavanine and S-aminoethylcysteine inhibition of steroidogenesis by arginine and lysine, respectively, suggests that the inhibitors are functioning as amino acid analogs. S-Aminoethylcysteine inhibits the incorporation of [3H]lysine into protein as well as inhibits steroidogenesis; further, [3H]S-aminoethylcysteine is incorporated into protein that is nonstimulatory. These results suggest that lysine residues play an essential role in the function of the labile protein or that the labile protein contains a large number of lysine residues

  6. Reinstatement of contextual conditioned anxiety in virtual reality and the effects of transcutaneous vagus nerve stimulation in humans.

    Science.gov (United States)

    Genheimer, Hannah; Andreatta, Marta; Asan, Esther; Pauli, Paul

    2017-12-20

    Since exposure therapy for anxiety disorders incorporates extinction of contextual anxiety, relapses may be due to reinstatement processes. Animal research demonstrated more stable extinction memory and less anxiety relapse due to vagus nerve stimulation (VNS). We report a valid human three-day context conditioning, extinction and return of anxiety protocol, which we used to examine effects of transcutaneous VNS (tVNS). Seventy-five healthy participants received electric stimuli (unconditioned stimuli, US) during acquisition (Day1) when guided through one virtual office (anxiety context, CTX+) but never in another (safety context, CTX-). During extinction (Day2), participants received tVNS, sham, or no stimulation and revisited both contexts without US delivery. On Day3, participants received three USs for reinstatement followed by a test phase. Successful acquisition, i.e. startle potentiation, lower valence, higher arousal, anxiety and contingency ratings in CTX+ versus CTX-, the disappearance of these effects during extinction, and successful reinstatement indicate validity of this paradigm. Interestingly, we found generalized reinstatement in startle responses and differential reinstatement in valence ratings. Altogether, our protocol serves as valid conditioning paradigm. Reinstatement effects indicate different anxiety networks underlying physiological versus verbal responses. However, tVNS did neither affect extinction nor reinstatement, which asks for validation and improvement of the stimulation protocol.

  7. Tooth pulp stimulation as an unconditioned stimulus in defensive instrumental conditioning.

    Science.gov (United States)

    Jastreboff, P J; Keller, O; Zieliński, K

    1977-01-01

    In an experiment performed on five cats, stable escape and avoidance reflexes in a bar-pressing situation were established using tooth pulp electric stimulation as the unconditioned stimulus. The influence of changes in parameters of the unconditioned stimulus (current intensity, single pulse and train durations, frequency of pulses and rate of train presentations) on unconditioned and instrumental responses was analysed in three additional subjects. Among other relationships the dependence of the threshold of bar press responses on the amount of charge in a single pulse was determined.

  8. A novel vibrotactile system for stimulating the glabrous skin of awake freely behaving rats during operant conditioning.

    Science.gov (United States)

    Devecioğlu, İsmail; Güçlü, Burak

    2015-03-15

    Rat skin is innervated by mechanoreceptive fibers similar to those in other mammals. Tactile experiments with behaving rats mostly focus on the vibrissal system which does not exist in humans. The aim of this study was to design and implement a novel vibrotactile system to stimulate the glabrous skin of behaving rats during operant conditioning. A computer-controlled vibrotactile system was developed for various tasks in which the volar surface of unrestrained rats' fore- and hindpaws was stimulated in an operant chamber. The operant chamber was built from off-the-shelf components. A highly accurate electrodynamic shaker with a novel multi-probe design was used for generating mechanical displacements. Twenty-five rats were trained for four sequential tasks: (A) middle-lever (trial start signal) press, (B) side-lever press with an associated visual cue, (C) similar to (B) with the addition of an auditory/tactile stimulus, (D) auditory/tactile detection (yes/no) task. Out of 9 rats which could complete the tactile version of this training schedule, 5 had over 70% accuracy in the tactile version of the detection task. Unlike actuators for stimulating whiskers, this system does not require a particular head/body alignment and can be used with freely behaving animals. The vibrotactile system was found to be effective for conditioning freely behaving rats based on stimuli applied on the glabrous skin. However, detection accuracies were lower compared to those in tasks involving whisker stimulation reported previously, probably due to differences in cortical processing. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Effects of vagus nerve stimulation on extinction of conditioned fear and post-traumatic stress disorder symptoms in rats.

    Science.gov (United States)

    Noble, L J; Gonzalez, I J; Meruva, V B; Callahan, K A; Belfort, B D; Ramanathan, K R; Meyers, E; Kilgard, M P; Rennaker, R L; McIntyre, C K

    2017-08-22

    Exposure-based therapies help patients with post-traumatic stress disorder (PTSD) to extinguish conditioned fear of trauma reminders. However, controlled laboratory studies indicate that PTSD patients do not extinguish conditioned fear as well as healthy controls, and exposure therapy has high failure and dropout rates. The present study examined whether vagus nerve stimulation (VNS) augments extinction of conditioned fear and attenuates PTSD-like symptoms in an animal model of PTSD. To model PTSD, rats were subjected to a single prolonged stress (SPS) protocol, which consisted of restraint, forced swim, loss of consciousness, and 1 week of social isolation. Like PTSD patients, rats subjected to SPS show impaired extinction of conditioned fear. The SPS procedure was followed, 1 week later, by auditory fear conditioning (AFC) and extinction. VNS or sham stimulation was administered during half of the extinction days, and was paired with presentations of the conditioned stimulus. One week after completion of extinction training, rats were given a battery of behavioral tests to assess anxiety, arousal and avoidance. Results indicated that rats given SPS 1 week prior to AFC (PTSD model) failed to extinguish the freezing response after eleven consecutive days of extinction. Administration of VNS reversed the extinction impairment and attenuated reinstatement of the conditioned fear response. Delivery of VNS during extinction also eliminated the PTSD-like symptoms, such as anxiety, hyperarousal and social avoidance for more than 1 week after VNS treatment. These results provide evidence that extinction paired with VNS treatment can lead to remission of fear and improvements in PTSD-like symptoms. Taken together, these findings suggest that VNS may be an effective adjunct to exposure therapy for the treatment of PTSD.

  10. Hexavalent chromium reduction under fermentative conditions with lactate stimulated native microbial communities.

    Science.gov (United States)

    Somenahally, Anil C; Mosher, Jennifer J; Yuan, Tong; Podar, Mircea; Phelps, Tommy J; Brown, Steven D; Yang, Zamin K; Hazen, Terry C; Arkin, Adam P; Palumbo, Anthony V; Van Nostrand, Joy D; Zhou, Jizhong; Elias, Dwayne A

    2013-01-01

    Microbial reduction of toxic hexavalent chromium (Cr(VI)) in-situ is a plausible bioremediation strategy in electron-acceptor limited environments. However, higher [Cr(VI)] may impose stress on syntrophic communities and impact community structure and function. The study objectives were to understand the impacts of Cr(VI) concentrations on community structure and on the Cr(VI)-reduction potential of groundwater communities at Hanford, WA. Steady state continuous flow bioreactors were used to grow native communities enriched with lactate (30 mM) and continuously amended with Cr(VI) at 0.0 (No-Cr), 0.1 (Low-Cr) and 3.0 (High-Cr) mg/L. Microbial growth, metabolites, Cr(VI), 16S rRNA gene sequences and GeoChip based functional gene composition were monitored for 15 weeks. Temporal trends and differences in growth, metabolite profiles, and community composition were observed, largely between Low-Cr and High-Cr bioreactors. In both High-Cr and Low-Cr bioreactors, Cr(VI) levels were below detection from week 1 until week 15. With lactate enrichment, native bacterial diversity substantially decreased as Pelosinus spp., and Sporotalea spp., became the dominant groups, but did not significantly differ between Cr concentrations. The Archaea diversity also substantially decreased after lactate enrichment from Methanosaeta (35%), Methanosarcina (17%) and others, to mostly Methanosarcina spp. (95%). Methane production was lower in High-Cr reactors suggesting some inhibition of methanogens. Several key functional genes were distinct in Low-Cr bioreactors compared to High-Cr. Among the Cr resistant microbes, Burkholderia vietnamiensis, Comamonas testosterone and Ralstonia pickettii proliferated in Cr amended bioreactors. In-situ fermentative conditions facilitated Cr(VI) reduction, and as a result 3.0 mg/L Cr(VI) did not impact the overall bacterial community structure.

  11. Hexavalent chromium reduction under fermentative conditions with lactate stimulated native microbial communities.

    Directory of Open Access Journals (Sweden)

    Anil C Somenahally

    Full Text Available Microbial reduction of toxic hexavalent chromium (Cr(VI in-situ is a plausible bioremediation strategy in electron-acceptor limited environments. However, higher [Cr(VI] may impose stress on syntrophic communities and impact community structure and function. The study objectives were to understand the impacts of Cr(VI concentrations on community structure and on the Cr(VI-reduction potential of groundwater communities at Hanford, WA. Steady state continuous flow bioreactors were used to grow native communities enriched with lactate (30 mM and continuously amended with Cr(VI at 0.0 (No-Cr, 0.1 (Low-Cr and 3.0 (High-Cr mg/L. Microbial growth, metabolites, Cr(VI, 16S rRNA gene sequences and GeoChip based functional gene composition were monitored for 15 weeks. Temporal trends and differences in growth, metabolite profiles, and community composition were observed, largely between Low-Cr and High-Cr bioreactors. In both High-Cr and Low-Cr bioreactors, Cr(VI levels were below detection from week 1 until week 15. With lactate enrichment, native bacterial diversity substantially decreased as Pelosinus spp., and Sporotalea spp., became the dominant groups, but did not significantly differ between Cr concentrations. The Archaea diversity also substantially decreased after lactate enrichment from Methanosaeta (35%, Methanosarcina (17% and others, to mostly Methanosarcina spp. (95%. Methane production was lower in High-Cr reactors suggesting some inhibition of methanogens. Several key functional genes were distinct in Low-Cr bioreactors compared to High-Cr. Among the Cr resistant microbes, Burkholderia vietnamiensis, Comamonas testosterone and Ralstonia pickettii proliferated in Cr amended bioreactors. In-situ fermentative conditions facilitated Cr(VI reduction, and as a result 3.0 mg/L Cr(VI did not impact the overall bacterial community structure.

  12. Hexavalent Chromium Reduction under Fermentative Conditions with Lactate Stimulated Native Microbial Communities

    Energy Technology Data Exchange (ETDEWEB)

    Somenahally, Anil C [ORNL; Mosher, Jennifer J [ORNL; Yuan, Tong [University of Oklahoma; Phelps, Tommy Joe [ORNL; Brown, Steven D [ORNL; Yang, Zamin Koo [ORNL; Hazen, Terry C [ORNL; Arkin, Adam [Lawrence Berkeley National Laboratory (LBNL); Palumbo, Anthony Vito [ORNL; Van Nostrand, Dr. Joy D. [Oklahoma University; Zhou, Jizhong [University of Oklahoma; Elias, Dwayne A [ORNL

    2013-01-01

    Microbial reduction of toxic hexavalent chromium (Cr(VI)) in-situ is a plausible bioremediation strategy in electron-acceptor limited environments. However, higher [Cr(VI)] may impose stress on syntrophic communities and impact community structure and function. The study objectives were to understand the impacts of Cr(VI) concentrations on community structure and on the Cr(VI)-reduction potential of groundwater communities at Hanford, WA. Steady state continuous flow bioreactors were used to grow native communities enriched with lactate (30 mM) and continuously amended with Cr(VI) at 0.0 (No-Cr), 0.1 (Low-Cr) and 3.0 (High-Cr) mg/L. Microbial growth, metabolites, Cr(VI), 16S rRNA gene sequences and GeoChip based functional gene composition were monitored for 15 weeks. Temporal trends and differences in growth, metabolite profiles, and community composition were observed, largely between Low-Cr and High-Cr bioreactors. In both High-Cr and Low-Cr bioreactors, Cr(VI) levels were below detection from week 1 until week 15. With lactate enrichment, native bacterial diversity substantially decreased as Pelosinus spp., and Sporotalea spp., became the dominant groups, but did not significantly differ between Cr concentrations. The Archaea diversity also substantially decreased after lactate enrichment from Methanosaeta (35%), Methanosarcina (17%) and others, to mostly Methanosarcina spp. (95%). Methane production was lower in High-Cr reactors suggesting some inhibition of methanogens. Several key functional genes were distinct in Low-Cr bioreactors compared to High-Cr. Among the Cr resistant microbes, Burkholderia vietnamiensis, Comamonas testosterone and Ralstonia pickettii proliferated in Cr amended bioreactors. In-situ fermentative conditions facilitated Cr(VI) reduction, and as a result 3.0 mg/L Cr(VI) did not impact the overall bacterial community structure.

  13. Neutrophil-induced transmigration of tumour cells treated with tumour-conditioned medium is facilitated by granulocyte-macrophage colony-stimulating factor.

    LENUS (Irish Health Repository)

    Wu, Q D

    2012-02-03

    OBJECTIVE: To investigate the effect of different cytokines that are present in tumour-conditioned medium on human neutrophil (PMN)-induced tumour cell transmigration. DESIGN: Laboratory study. SETTING: University hospital, Ireland. MATERIAL: Isolated human PMN and cultured human breast tumour cell line, MDA-MB-231. Interventions: Human PMN treated with either tumour-conditioned medium or different media neutralised with monoclonal antibodies (MoAb), and MDA-MB-231 cells were plated on macrovascular and microvascular endothelial monolayers in collagen-coated transwells to assess migration of tumour cells. MAIN OUTCOME MEASURES: Cytokines present in tumour-conditioned medium, PMN cytocidal function and receptor expression, and tumour cell transmigration. RESULTS: tumour-conditioned medium contained high concentrations of granulocyte-macrophage colony-stimulating factor (GM-CSF), vascular endothelial growth factor (VEGF), and interleukin 8 (IL-8), but not granulocyte colony-stimulating factor (G-CSF) and interleukin 3 (IL-3). Anti-GM-CSF MoAb significantly reduced PMN-induced transmigration of tumour cells treated with tumour-conditioned medium (p < 0.05), whereas anti-VEGF and anti-IL-8 MoAbs did not affect their migration. In addition, anti-GM-CSF MoAb, but not anti-VEGF or anti-IL-8 MoAb, reduced PMN CD11b and CD18 overexpression induced by tumour-conditioned medium (p < 0.05). CONCLUSION: These results indicate that the GM-CSF that is present in tumour-conditioned medium may be involved, at least in part, in alterations in PMN function mediated by the medium and subsequently PMN-induced transmigration of tumour cells.

  14. Collision-induced stimulated photon echo generated at transition 0-1 on broad spectral line conditions

    Science.gov (United States)

    Rubtsova, N. N.; Gol'dort, V. G.; Ishchenko, V. N.; Khvorostov, E. B.; Kochubei, S. A.; Borisov, G. M.; Ledovskikh, D. V.; Reshetov, V. A.

    2018-04-01

    For the first time, the collision induced stimulated photon echo generated at transition 1S0 → 3 P1 of 174Yb (type 0-1) in the mixture of gases Yb  +  Xe was investigated in the presence of weak longitudinal magnetic field, with experimental parameters corresponding to broad spectral line conditions. Comparison of the experimental echo amplitude versus magnetic field strength dependence with the theoretical curve shows a very good agreement, giving rise to an improved estimate for the difference between alignment and orientation decay rates.

  15. Medial Auditory Thalamus Is Necessary for Acquisition and Retention of Eyeblink Conditioning to Cochlear Nucleus Stimulation

    Science.gov (United States)

    Halverson, Hunter E.; Poremba, Amy; Freeman, John H.

    2015-01-01

    Associative learning tasks commonly involve an auditory stimulus, which must be projected through the auditory system to the sites of memory induction for learning to occur. The cochlear nucleus (CN) projection to the pontine nuclei has been posited as the necessary auditory pathway for cerebellar learning, including eyeblink conditioning.…

  16. Positive impact of bio-stimulators on growth and physiological activity of willow in climate change conditions

    Science.gov (United States)

    Piotrowski, Krzysztof; Romanowska-Duda, Zdzisława

    2018-04-01

    The aim of this research was to evaluate the physiological activity and growth of willow (Salix viminalis L.) plants cultivated under the conditions of adverse temperature and soil moisture content, and to assess the effect of the foliar application of Biojodis (1.0%) and Asahi SL (0.03%) bio-stimulators, or a mixture of Microcistis aeruginosa MKR 0105 and Anabaena PCC 7120 cyanobacteria under such changing growth conditions. The obtained results showed different reactions to the applied constant or periodically changed temperature and soil moisture content. The plants which grew at periodically changed adverse temperature (from -5 to 40oC) or in scantily (20% m.c.) or excessively (60% m.c.) watered soils, grew slowly, in comparison with those growing at 20oC and in optimally moistened soil (30% m.c.). Foliar application of Biojodis and Asahi SL cyanobacteria increased the growth of willow at optimal and adverse temperature or in scantily and excessively moistened soil. The changes in plant growth were associated with the changes in electrolyte leakage, activity of acid or alkaline phosphatases, RNase, index of chlorophyll content in leaves and gas exchange. The above indicates that the foliar application of the studied cyanobacteria and bio-stimulators partly alleviates the harmful impact of adverse temperature and water stress on growth and physiological activity of willow plants

  17. Conditional probability distribution associated to the E-M image reconstruction algorithm for neutron stimulated emission tomography

    International Nuclear Information System (INIS)

    Viana, R.S.; Yoriyaz, H.; Santos, A.

    2011-01-01

    The Expectation-Maximization (E-M) algorithm is an iterative computational method for maximum likelihood (M-L) estimates, useful in a variety of incomplete-data problems. Due to its stochastic nature, one of the most relevant applications of E-M algorithm is the reconstruction of emission tomography images. In this paper, the statistical formulation of the E-M algorithm was applied to the in vivo spectrographic imaging of stable isotopes called Neutron Stimulated Emission Computed Tomography (NSECT). In the process of E-M algorithm iteration, the conditional probability distribution plays a very important role to achieve high quality image. This present work proposes an alternative methodology for the generation of the conditional probability distribution associated to the E-M reconstruction algorithm, using the Monte Carlo code MCNP5 and with the application of the reciprocity theorem. (author)

  18. Conditional probability distribution associated to the E-M image reconstruction algorithm for neutron stimulated emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Viana, R.S.; Yoriyaz, H.; Santos, A., E-mail: rodrigossviana@gmail.com, E-mail: hyoriyaz@ipen.br, E-mail: asantos@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The Expectation-Maximization (E-M) algorithm is an iterative computational method for maximum likelihood (M-L) estimates, useful in a variety of incomplete-data problems. Due to its stochastic nature, one of the most relevant applications of E-M algorithm is the reconstruction of emission tomography images. In this paper, the statistical formulation of the E-M algorithm was applied to the in vivo spectrographic imaging of stable isotopes called Neutron Stimulated Emission Computed Tomography (NSECT). In the process of E-M algorithm iteration, the conditional probability distribution plays a very important role to achieve high quality image. This present work proposes an alternative methodology for the generation of the conditional probability distribution associated to the E-M reconstruction algorithm, using the Monte Carlo code MCNP5 and with the application of the reciprocity theorem. (author)

  19. Using the new board game SeCZ TaLK to stimulate the communication on sexual health for adolescents with chronic conditions

    NARCIS (Netherlands)

    A. Visser; Dr. H.A. van der Stege; Dr. S.R. Hilberink; Dr. A.L. van Staa

    2010-01-01

    This study evaluated the feasibility and appreciation of a new educational board game (SeCZ TaLK) that stimulates communication on sexuality and intimate relationships in youth with chronic conditions.

  20. Significance of settling model structures and parameter subsets in modelling WWTPs under wet-weather flow and filamentous bulking conditions

    DEFF Research Database (Denmark)

    Ramin, Elham; Sin, Gürkan; Mikkelsen, Peter Steen

    2014-01-01

    Current research focuses on predicting and mitigating the impacts of high hydraulic loadings on centralized wastewater treatment plants (WWTPs) under wet-weather conditions. The maximum permissible inflow to WWTPs depends not only on the settleability of activated sludge in secondary settling tanks...... (SSTs) but also on the hydraulic behaviour of SSTs. The present study investigates the impacts of ideal and non-ideal flow (dry and wet weather) and settling (good settling and bulking) boundary conditions on the sensitivity of WWTP model outputs to uncertainties intrinsic to the one-dimensional (1-D...... of settling parameters to the total variance of the key WWTP process outputs significantly depends on the influent flow and settling conditions. The magnitude of the impact is found to vary, depending on which type of 1-D SST model is used. Therefore, we identify and recommend potential parameter subsets...

  1. Mechanism of S100b release from rat cortical slices determined under basal and stimulated conditions.

    Science.gov (United States)

    Gürsoy, Murat; Büyükuysal, R Levent

    2010-03-01

    Incubation of rat cortical slices in a medium that was not containing oxygen and glucose (oxygen-glucose deprivation, OGD) caused a 200% increase in the release of S100B. However, when slices were transferred to a medium containing oxygen and glucose (reoxygenation conditions, or REO), S100B release reached 500% of its control value. Neither inhibition of nitric oxide (NO) synthase by L-NAME nor addition of the NO donors sodium nitroprussid (SNP) or hydroxylamine (HA) to the medium altered basal S100B release. Similarly, the presence of SNP, HA or NO precursor L: -arginine in the medium, or inhibition of NO synthase by L-NAME also failed to alter OGD- and REO-induced S100B outputs. Moreover, individual inhibition of PKC, PLA(2) or PLC all failed to attenuate the S100B release determined under control condition or enhanced by either OGD or REO. Blockade of calcium channels with verapamil, chelating the Ca(+2) ions with BAPTA or blockade of sodium channels with tetrodotoxin (TTX) did not alter OGD- and REO-induced S100B release. In contrast to the pharmacologic manipulations mentioned above, glutamate and alpha-ketoglutarate added at high concentrations to the medium prevented both OGD- and REO-induced S100B outputs. These results indicate that neither NO nor the activation of PKC, PLA(2) or PLC seem to be involved in basal or OGD- and REO-induced S100B outputs. Additionally, calcium and sodium currents that are sensitive to verapamil and TTX, respectively, are unlikely to contribute to the enhanced S100B release observed under these conditions.

  2. In vitro stimulation of vascular endothelial growth factor by borate-based glass fibers under dynamic flow conditions

    International Nuclear Information System (INIS)

    Chen, Sisi; Yang, Qingbo; Brow, Richard K.; Liu, Kun; Brow, Katherine A.; Ma, Yinfa

    2017-01-01

    Bioactive borate glass has been recognized to have both hard and soft tissue repair and regeneration capabilities through stimulating both osteogenesis and angiogenesis. However, the underlying biochemical and cellular mechanisms remain unclear. In this study, dynamic flow culturing modules were designed to simulate the micro-environment near the vascular depletion and hyperplasia area in wound-healing regions, thus to better investigate the mechanisms underlying the biocompatibility and functionality of borate-based glass materials. Glass fibers were dosed either upstream or in contact with the pre-seeded cells in the dynamic flow module. Two types of borate glasses, doped with (1605) or without (13-93B3) CuO and ZnO, were studied along with the silicate-based glass, 45S5. Substantial fiber dissolution in cell culture medium was observed, leading to the release of ions (boron, sodium and potassium) and the deposition of a calcium phosphate phase. Different levels of vascular endothelial growth factor secretion were observed from cells exposed to these three glass fibers, and the copper/zinc containing borate 1605 fibers exhibited the most positive influence. These results indicate that dynamic studies of in vitro bioactivity provide useful information to understand the in vivo response to bioactive borate glasses. - Highlights: • Novel dynamic flow cell culture modules were designed. • Bioactive glass fibers were evaluated for their effects on VEGF secretion. • Borate-based glass fibers stimulate VEGF secretion under dynamic condition. • CuO and ZnO doped borate-based glass fibers stimulate the greatest VEGF release.

  3. In vitro stimulation of vascular endothelial growth factor by borate-based glass fibers under dynamic flow conditions

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Sisi [Department of Chemistry, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Center for Biomedical Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Yang, Qingbo [Department of Chemistry, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Center for Biomedical Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Center for Single Nanoparticle, Single Cell, and Single Molecule Monitoring, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Brow, Richard K. [Department of Material Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Center for Biomedical Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Liu, Kun [Department of Chemistry, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Center for Single Nanoparticle, Single Cell, and Single Molecule Monitoring, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Brow, Katherine A. [Department of Chemistry, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Ma, Yinfa [Department of Chemistry, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Center for Biomedical Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Center for Single Nanoparticle, Single Cell, and Single Molecule Monitoring, Missouri University of Science and Technology, Rolla, MO 65409 (United States); and others

    2017-04-01

    Bioactive borate glass has been recognized to have both hard and soft tissue repair and regeneration capabilities through stimulating both osteogenesis and angiogenesis. However, the underlying biochemical and cellular mechanisms remain unclear. In this study, dynamic flow culturing modules were designed to simulate the micro-environment near the vascular depletion and hyperplasia area in wound-healing regions, thus to better investigate the mechanisms underlying the biocompatibility and functionality of borate-based glass materials. Glass fibers were dosed either upstream or in contact with the pre-seeded cells in the dynamic flow module. Two types of borate glasses, doped with (1605) or without (13-93B3) CuO and ZnO, were studied along with the silicate-based glass, 45S5. Substantial fiber dissolution in cell culture medium was observed, leading to the release of ions (boron, sodium and potassium) and the deposition of a calcium phosphate phase. Different levels of vascular endothelial growth factor secretion were observed from cells exposed to these three glass fibers, and the copper/zinc containing borate 1605 fibers exhibited the most positive influence. These results indicate that dynamic studies of in vitro bioactivity provide useful information to understand the in vivo response to bioactive borate glasses. - Highlights: • Novel dynamic flow cell culture modules were designed. • Bioactive glass fibers were evaluated for their effects on VEGF secretion. • Borate-based glass fibers stimulate VEGF secretion under dynamic condition. • CuO and ZnO doped borate-based glass fibers stimulate the greatest VEGF release.

  4. Alkaline conditions stimulate the production of 1,3-propanediol in Lactobacillus panis PM1 through shifting metabolic pathways.

    Science.gov (United States)

    Grahame, Douglas A S; Kang, Tae Sun; Khan, Nurul H; Tanaka, Takuji

    2013-07-01

    A novel Lactobacillus panis PM1 isolate was found to be capable of converting glycerol to 1,3-propanediol (1,3-PDO), an increasingly valuable commodity chemical. In this study the effects of various process parameters, including glucose and glycerol concentrations, inoculum size, temperature, aeration, pH, and carbon source were examined to determine the optimal conditions for the production of 1,3-PDO using a culture method simulating late log to early stationary phases. Inoculum size did not influence the production of 1,3-PDO, and temperature variance showed similar 1,3-PDO production between 25 and 37 °C under the examined conditions. Glycerol concentration and pH played a primary role in the final concentration of 1,3-PDO. The highest production occurred at 150-250 mM glycerol when 50 mM glucose was available. Alkaline initial conditions (pH 9-10) stimulated the production of 1,3-PDO which concurrently occurred with increased acetic acid production. Under these conditions, 213.6 mM of 1,3-PDO were produced from 300 mM glycerol (conversion efficiency was 71 %). These observations indicated that the production of 1,3-PDO was associated with the shift of the metabolic end-product ethanol to acetic acid, and that this shift resulted in an excess concentration of NADH available for the processing of glycerol to 1,3-PDO.

  5. Significance of settling model structures and parameter subsets in modelling WWTPs under wet-weather flow and filamentous bulking conditions.

    Science.gov (United States)

    Ramin, Elham; Sin, Gürkan; Mikkelsen, Peter Steen; Plósz, Benedek Gy

    2014-10-15

    Current research focuses on predicting and mitigating the impacts of high hydraulic loadings on centralized wastewater treatment plants (WWTPs) under wet-weather conditions. The maximum permissible inflow to WWTPs depends not only on the settleability of activated sludge in secondary settling tanks (SSTs) but also on the hydraulic behaviour of SSTs. The present study investigates the impacts of ideal and non-ideal flow (dry and wet weather) and settling (good settling and bulking) boundary conditions on the sensitivity of WWTP model outputs to uncertainties intrinsic to the one-dimensional (1-D) SST model structures and parameters. We identify the critical sources of uncertainty in WWTP models through global sensitivity analysis (GSA) using the Benchmark simulation model No. 1 in combination with first- and second-order 1-D SST models. The results obtained illustrate that the contribution of settling parameters to the total variance of the key WWTP process outputs significantly depends on the influent flow and settling conditions. The magnitude of the impact is found to vary, depending on which type of 1-D SST model is used. Therefore, we identify and recommend potential parameter subsets for WWTP model calibration, and propose optimal choice of 1-D SST models under different flow and settling boundary conditions. Additionally, the hydraulic parameters in the second-order SST model are found significant under dynamic wet-weather flow conditions. These results highlight the importance of developing a more mechanistic based flow-dependent hydraulic sub-model in second-order 1-D SST models in the future. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Elevated Atmospheric CO2 and Warming Stimulates Growth and Nitrogen Fixation in a Common Forest Floor Cyanobacterium under Axenic Conditions

    Directory of Open Access Journals (Sweden)

    Zoë Lindo

    2017-03-01

    Full Text Available The predominant input of available nitrogen (N in boreal forest ecosystems originates from moss-associated cyanobacteria, which fix unavailable atmospheric N2, contribute to the soil N pool, and thereby support forest productivity. Alongside climate warming, increases in atmospheric CO2 concentrations are expected in Canada’s boreal region over the next century, yet little is known about the combined effects of these factors on N fixation by forest floor cyanobacteria. Here we assess changes in N fixation in a common forest floor, moss-associated cyanobacterium, Nostoc punctiforme Hariot, under elevated CO2 conditions over 30 days and warming combined with elevated CO2 over 90 days. We measured rates of growth and changes in the number of specialized N2 fixing heterocyst cells, as well as the overall N fixing activity of the cultures. Elevated CO2 stimulated growth and N fixation overall, but this result was influenced by the growth stage of the cyanobacteria, which in turn was influenced by our temperature treatments. Taken together, climate change factors of warming and elevated CO2 are expected to stimulate N2 fixation by moss-associated cyanobacteria in boreal forest systems.

  7. Defibrotide in combination with granulocyte colony-stimulating factor significantly enhances the mobilization of primitive and committed peripheral blood progenitor cells in mice.

    Science.gov (United States)

    Carlo-Stella, Carmelo; Di Nicola, Massimo; Magni, Michele; Longoni, Paolo; Milanesi, Marco; Stucchi, Claudio; Cleris, Loredana; Formelli, Franca; Gianni, Massimo A

    2002-11-01

    Defibrotide is a polydeoxyribonucleotide, which significantly reduces the expression of adhesion molecules on endothelial cells. We investigated the activity of Defibrotide alone or in combination with recombinant human granulocyte colony-stimulating factor (rhG-CSF) to mobilize peripheral blood progenitor cells (PBPCs) in BALB/c mice. A 5-day treatment with Defibrotide alone (1-15 mg/mouse/day) had no effect on WBC counts, frequencies and absolute numbers of total circulating colony-forming cells (CFCs), i.e., granulocyte-macrophage colony-forming units, erythroid burst-forming units, and multilineage colony-forming units. As compared with mock-injected mice, administration of rhG-CSF alone (5 micro g/mouse/day) for 5 days significantly (P Defibrotide (15 mg/mouse/day) and rhG-CSF significantly (P Defibrotide plus rhG-CSF resulted in a significant increase (P Defibrotide/rhG-CSF-mobilized mononuclear cells rescued 43% and 71% of recipient mice, respectively. Experiments of CFC homing performed in lethally irradiated or nonirradiated recipients showed that marrow homing of transplanted PBPCs was reduced by 3-fold in Defibrotide-treated animals as compared with mock-injected mice (P Defibrotide might be because of an effect on PBPC trafficking. In conclusion, our data demonstrate that Defibrotide synergizes with rhG-CSF and significantly increases the mobilization of a broad spectrum of PBPCs, including primitive and committed progenitor cells. These data might have relevant implications for autologous and allogeneic anticancer therapy in humans.

  8. Multicolumn spinal cord stimulation for significant low back pain in failed back surgery syndrome: design of a national, multicentre, randomized, controlled health economics trial (ESTIMET Study).

    Science.gov (United States)

    Roulaud, M; Durand-Zaleski, I; Ingrand, P; Serrie, A; Diallo, B; Peruzzi, P; Hieu, P D; Voirin, J; Raoul, S; Page, P; Fontaine, D; Lantéri-Minet, M; Blond, S; Buisset, N; Cuny, E; Cadenne, M; Caire, F; Ranoux, D; Mertens, P; Naous, H; Simon, E; Emery, E; Gadan, B; Regis, J; Sol, J-C; Béraud, G; Debiais, F; Durand, G; Guetarni Ging, F; Prévost, A; Brandet, C; Monlezun, O; Delmotte, A; d'Houtaud, S; Bataille, B; Rigoard, P

    2015-03-01

    Many studies have demonstrated the efficacy of spinal cord stimulation (SCS) for chronic neuropathic radicular pain over recent decades, but despite global favourable outcomes in failed back surgery syndrome (FBSS) with leg pain, the back pain component remains poorly controlled by neurostimulation. Technological and scientific progress has led to the development of new SCS leads, comprising a multicolumn design and a greater number of contacts. The efficacy of multicolumn SCS lead configurations for the treatment of the back pain component of FBSS has recently been suggested by pilot studies. However, a randomized controlled trial must be conducted to confirm the efficacy of new generation multicolumn SCS. Évaluation médico-économique de la STImulation MEdullaire mulTi-colonnes (ESTIMET) is a multicentre, randomized study designed to compare the clinical efficacy and health economics aspects of mono- vs. multicolumn SCS lead programming in FBSS patients with radicular pain and significant back pain. FBSS patients with a radicular pain VAS score≥50mm, associated with a significant back pain component were recruited in 14 centres in France and implanted with multicolumn SCS. Before the lead implantation procedure, they were 1:1 randomized to monocolumn SCS (group 1) or multicolumn SCS (group 2). Programming was performed using only one column for group 1 and full use of the 3 columns for group 2. Outcome assessment was performed at baseline (pre-implantation), and 1, 3, 6 and 12months post-implantation. The primary outcome measure was a reduction of the severity of low back pain (bVAS reduction≥50%) at the 6-month visit. Additional outcome measures were changes in global pain, leg pain, paraesthesia coverage mapping, functional capacities, quality of life, neuropsychological aspects, patient satisfaction and healthcare resource consumption. Trial recruitment started in May 2012. As of September 2013, all 14 study centres have been initiated and 112

  9. Research project: State and Stimulation of Developmet in Chidren Aged 8-9 Living Under War Conditions

    Directory of Open Access Journals (Sweden)

    M. Vranešić

    1998-02-01

    Full Text Available The somatic, functional and metabolic characteristics of children at 8 years of age have been established. These children have, for the previous three years, lived under stressful conditions of direct shelling, poor nutrition and movement. At the same time there has been an evaluation of the effects of programmed physical activities which have been applied in the aim of stimulating natural physical dynamics and functional developments and the elimination of stagnation of development which occurs from conditions of unfavorable factors. The research and the program of physical activities included 41 boys, starting at an average age of 8 years and four months. The somatic characteristics of the boys, according to 25 antropo-metric measures (IBP, show a lag in the boy’s physical development according to their age group by one year. The lagging behind is especially evident in volume dimensions and underskin tissue fat (Przulj, 1991., Bonacin, 1995. Blaha, 1982.. An improvement of conditions and a greater scope of movement activities for the duration of 8 months did not significantly influence on the improvement of the somatic and functional status of the boys in comparison with the controlled group (N=21 of the same average age during another measurement period. While resting, on the level of aerobic threshold, anaerobic threshold and maximal oxygen uptake, the value of ergonometric, functional and metabolic parameters were confirmed: V02 stpd, Ve btps. Ve * V02-1, Ve*VC02-l, RQ, fc (beats*min-l, work load in Watts and on the basis of these relative indicators were completed. The gradual growth of work load was completed with the help of bicyklergometer (Monark. After 3 minutes of easy pedaling (warming-up an initial work load was given of Watt*body mass and increased by 1/3 of the mass*Watt every minute until the achievement of maximal oxygen uptake. Individual aerobic and anaerobic thresholds (Aep and (Anp, for each person examined were confirmed

  10. Determination of some significant batch culture conditions affecting acetyl-xylan esterase production by Penicillium notatum NRRL-1249

    Directory of Open Access Journals (Sweden)

    Akhtar MN

    2011-05-01

    Full Text Available Abstract Background Acetyl-xylan esterase (AXE, EC 3.1.1.72 hydrolyses acetate group from the linear chain of xylopyranose residues bound by β-1,4-linkage. The enzyme finds commercial applications in bio-bleaching of wood pulp, treating animal feed to increase digestibility, processing food to increase clarification and converting lignocellulosics to feedstock and fuel. In the present study, we report on the production of an extracellular AXE from Penicillium notatum NRRL-1249 by solid state fermentation (SSF. Results Wheat bran at a level of 10 g (with 4 cm bed height was optimized as the basal substrate for AXE production. An increase in enzyme activity was observed when 7.5 ml of mineral salt solution (MSS containing 0.1% KH2PO4, 0.05% KCl, 0.05% MgSO4.7H2O, 0.3% NaNO3, 0.001% FeSO4.2H2O and 0.1% (v/w Tween-80 as an initial moisture content was used. Various nitrogen sources including ammonium sulphate, urea, peptone and yeast extract were compared for enzyme production. Maximal enzyme activity of 760 U/g was accomplished which was found to be highly significant (p ≤ 0.05. A noticeable enhancement in enzyme activity was observed when the process parameters including incubation period (48 h, initial pH (5, 0.2% (w/w urea as nitrogen source and 0.5% (v/w Tween-80 as a stimulator were further optimized using a 2-factorial Plackett-Burman design. Conclusion From the results it is clear that an overall improvement of more than 35% in terms of net enzyme activity was achieved compared to previously reported studies. This is perhaps the first report dealing with the use of P. notatum for AXE production under batch culture SSF. The Plackett-Burman model terms were found highly significant (HS, suggesting the potential commercial utility of the culture used (df = 3, LSD = 0.126.

  11. Interrater and intrarater agreements of magnetic resonance imaging findings in the lumbar spine: significant variability across degenerative conditions.

    Science.gov (United States)

    Fu, Michael C; Buerba, Rafael A; Long, William D; Blizzard, Daniel J; Lischuk, Andrew W; Haims, Andrew H; Grauer, Jonathan N

    2014-10-01

    agreement. However, when stratified by condition, absolute interrater agreement ranged from 65.1% to 92.0%. Disc hydration, disc space height, and bone marrow changes exhibited the lowest absolute interrater agreements. The absolute intrarater agreement had a narrower range, from 74.5% to 91.5%. Fleiss kappa coefficients ranged from fair-to-substantial agreement (0.282-0.618). Even in a study using standardized evaluation criteria, there was significant variability in the interrater and intrarater agreements of MRI in assessing different degenerative conditions of the lumbar spine. Clinicians should be aware of the condition-specific diagnostic limitations of MRI interpretation. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Reduction of hexavalent chromium by Pannonibacter phragmitetus LSSE-09 stimulated with external electron donors under alkaline conditions

    International Nuclear Information System (INIS)

    Xu Lin; Luo Mingfang; Li Wangliang; Wei Xuetuan; Xie Keng; Liu Lijun; Jiang Chengying; Liu Huizhou

    2011-01-01

    Research highlights: → Growing cells have high Cr (VI) resistant and reducing ability aerobically. → Resting cells show strong anaerobic-reduction potential. → Acetate can highly stimulate both aerobic and anaerobic reduction process. - Abstract: A novel Cr (VI) resistant bacterial strain LSSE-09, identified as Pannonibacter phragmitetus, was isolated from industrial sludge. It has strong aerobic and anaerobic Cr (VI)-reduction potential under alkaline conditions. At 37 o C and pH 9.0, growing cells of strain LSSE-09 could completely reduce 100 and 1000 mg L -1 Cr (VI)-Cr (III) within 9 and 24 h, respectively under aerobic condition. Resting cells showed higher anaerobic reduction potential with the rate of 1.46 mg g -1 (dryweight) min -1 , comparing with their aerobic reduction rate, 0.21 mg g -1 min -1 . External electron donors, such as lactate, acetate, formate, pyruvate, citrate and glucose could highly increase the reduction rate, especially for aerobic reduction. The presence of 3000 mg L -1 acetate enhanced anaerobic and aerobic Cr (VI)-reduction rates up to 9.47 mg g -1 min -1 and 4.42 mg g -1 min -1 , respectively, which were 5 and 20 times faster than those without it. Strain LSSE-09 retained high activities over six batch cycles and NO 3 - and SO 4 2- had slightly negative effects on Cr (VI)-reduction rates. The results suggest that strain LSSE-09 has potential application for Cr (VI) detoxification in alkaline wastewater.

  13. Amphetamine-type stimulant use and conditional paths of consumption: data from the Second Brazilian National Alcohol and Drugs Survey

    Directory of Open Access Journals (Sweden)

    Luciana T.S. Massaro

    2017-07-01

    Full Text Available Objective: The aim of this study was to estimate nationally representative prevalence rates of amphetamine-type stimulant (ATS use and to identify consumption-associated factors, proposing a conditional model of direct and indirect consumption paths. Method: Using data from the Second Brazilian National Alcohol and Drugs Survey, this cross-sectional study analyzed a subsample of 3,828 participants between 15 and 64 years old, gathering information on the use of psychoactive substances in a probabilistic sample of the Brazilian household population. Results: Rates of lifetime and last-year ATS use were, respectively, 4.1 and 1.6%. Economically privileged individuals and users of other substances were more at risk for using ATS. The results suggest that higher education decreases the chances of ATS consumption. The conditional model showed that higher income increased ATS use, higher education lowered the odds of such an increase, and cocaine use cancelled that associative effect. Conclusion: Brazil presents high rates of ATS use. Prevention and treatment strategies should focus on the protective effect of higher education levels and should target polydrug use. Knowledge of ATS-associated factors and user profiles is the starting point for developing effective treatments and tailored prevention strategies.

  14. A more robust model of the biodiesel reaction, allowing identification of process conditions for significantly enhanced rate and water tolerance.

    Science.gov (United States)

    Eze, Valentine C; Phan, Anh N; Harvey, Adam P

    2014-03-01

    A more robust kinetic model of base-catalysed transesterification than the conventional reaction scheme has been developed. All the relevant reactions in the base-catalysed transesterification of rapeseed oil (RSO) to fatty acid methyl ester (FAME) were investigated experimentally, and validated numerically in a model implemented using MATLAB. It was found that including the saponification of RSO and FAME side reactions and hydroxide-methoxide equilibrium data explained various effects that are not captured by simpler conventional models. Both the experiment and modelling showed that the "biodiesel reaction" can reach the desired level of conversion (>95%) in less than 2min. Given the right set of conditions, the transesterification can reach over 95% conversion, before the saponification losses become significant. This means that the reaction must be performed in a reactor exhibiting good mixing and good control of residence time, and the reaction mixture must be quenched rapidly as it leaves the reactor. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Significance of oxidized low-density lipoprotein in body fluids as a marker related to diseased conditions.

    Science.gov (United States)

    Itabe, Hiroyuki; Kato, Rina; Sasabe, Naoko; Obama, Takashi; Yamamoto, Matsuo

    2018-03-06

    Oxidatively modified low-density lipoprotein (oxLDL) is known to be involved in various diseases, including cardiovascular diseases. The presence of oxLDL in the human circulatory system and in atherosclerotic lesions has been demonstrated using monoclonal antibodies. Studies have shown the significance of circulating oxLDL in various systemic diseases, including acute myocardial infarction and diabetic mellitus. Several different enzyme-linked immunosorbent assay (ELISA) procedures to measure oxLDL were utilized. Evidence has been accumulating that reveals changes in oxLDL levels under certain pathological conditions. Since oxLDL concentration tends to correlate with low-density lipoprotein (LDL)-cholesterol, the ratio of oxLDL and LDL rather than oxLDL concentration alone has been focused attention. In addition to circulating plasma, LDL and oxLDL are found in gingival crevicular fluid (GCF), where the ratio of oxLDL to LDL in GCF is much higher than in plasma. LDL and oxLDL levels in GCF show an increase in diabetic patients and periodontal patients, suggesting that GCF might be useful in examining systemic conditions. GCF oxLDL increased when the teeth were affected by periodontitis. It is likely that oxLDL levels in plasma and GCF could reflect oxidative stress and transfer efficacy in circulatory system. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  16. Ghrelin receptor antagonism attenuates cocaine- and amphetamine-induced locomotor stimulation, accumbal dopamine release, and conditioned place preference.

    Science.gov (United States)

    Jerlhag, Elisabet; Egecioglu, Emil; Dickson, Suzanne L; Engel, Jörgen A

    2010-09-01

    Recently we demonstrated that genetic or pharmacological suppression of the central ghrelin signaling system, involving the growth hormone secretagogue receptor 1A (GHS-R1A), lead to a reduced reward profile from alcohol. As the target circuits for ghrelin in the brain include a mesolimbic reward pathway that is intimately associated with reward-seeking behaviour, we sought to determine whether the central ghrelin signaling system is required for reward from drugs of abuse other than alcohol, namely cocaine or amphetamine. We found that amphetamine-as well as cocaine-induced locomotor stimulation and accumbal dopamine release were reduced in mice treated with a GHS-R1A antagonist. Moreover, the ability of these drugs to condition a place preference was also attenuated by the GHS-R1A antagonist. Thus GHS-R1A appears to be required not only for alcohol-induced reward, but also for reward induced by psychostimulant drugs. Our data suggest that the central ghrelin signaling system constitutes a novel potential target for treatment of addictive behaviours such as drug dependence.

  17. Identifying significant genetic regulatory networks in the prostate cancer from microarray data based on transcription factor analysis and conditional independency

    Directory of Open Access Journals (Sweden)

    Yeh Cheng-Yu

    2009-12-01

    Full Text Available Abstract Background Prostate cancer is a world wide leading cancer and it is characterized by its aggressive metastasis. According to the clinical heterogeneity, prostate cancer displays different stages and grades related to the aggressive metastasis disease. Although numerous studies used microarray analysis and traditional clustering method to identify the individual genes during the disease processes, the important gene regulations remain unclear. We present a computational method for inferring genetic regulatory networks from micorarray data automatically with transcription factor analysis and conditional independence testing to explore the potential significant gene regulatory networks that are correlated with cancer, tumor grade and stage in the prostate cancer. Results To deal with missing values in microarray data, we used a K-nearest-neighbors (KNN algorithm to determine the precise expression values. We applied web services technology to wrap the bioinformatics toolkits and databases to automatically extract the promoter regions of DNA sequences and predicted the transcription factors that regulate the gene expressions. We adopt the microarray datasets consists of 62 primary tumors, 41 normal prostate tissues from Stanford Microarray Database (SMD as a target dataset to evaluate our method. The predicted results showed that the possible biomarker genes related to cancer and denoted the androgen functions and processes may be in the development of the prostate cancer and promote the cell death in cell cycle. Our predicted results showed that sub-networks of genes SREBF1, STAT6 and PBX1 are strongly related to a high extent while ETS transcription factors ELK1, JUN and EGR2 are related to a low extent. Gene SLC22A3 may explain clinically the differentiation associated with the high grade cancer compared with low grade cancer. Enhancer of Zeste Homolg 2 (EZH2 regulated by RUNX1 and STAT3 is correlated to the pathological stage

  18. Identifying significant genetic regulatory networks in the prostate cancer from microarray data based on transcription factor analysis and conditional independency.

    Science.gov (United States)

    Yeh, Hsiang-Yuan; Cheng, Shih-Wu; Lin, Yu-Chun; Yeh, Cheng-Yu; Lin, Shih-Fang; Soo, Von-Wun

    2009-12-21

    Prostate cancer is a world wide leading cancer and it is characterized by its aggressive metastasis. According to the clinical heterogeneity, prostate cancer displays different stages and grades related to the aggressive metastasis disease. Although numerous studies used microarray analysis and traditional clustering method to identify the individual genes during the disease processes, the important gene regulations remain unclear. We present a computational method for inferring genetic regulatory networks from micorarray data automatically with transcription factor analysis and conditional independence testing to explore the potential significant gene regulatory networks that are correlated with cancer, tumor grade and stage in the prostate cancer. To deal with missing values in microarray data, we used a K-nearest-neighbors (KNN) algorithm to determine the precise expression values. We applied web services technology to wrap the bioinformatics toolkits and databases to automatically extract the promoter regions of DNA sequences and predicted the transcription factors that regulate the gene expressions. We adopt the microarray datasets consists of 62 primary tumors, 41 normal prostate tissues from Stanford Microarray Database (SMD) as a target dataset to evaluate our method. The predicted results showed that the possible biomarker genes related to cancer and denoted the androgen functions and processes may be in the development of the prostate cancer and promote the cell death in cell cycle. Our predicted results showed that sub-networks of genes SREBF1, STAT6 and PBX1 are strongly related to a high extent while ETS transcription factors ELK1, JUN and EGR2 are related to a low extent. Gene SLC22A3 may explain clinically the differentiation associated with the high grade cancer compared with low grade cancer. Enhancer of Zeste Homolg 2 (EZH2) regulated by RUNX1 and STAT3 is correlated to the pathological stage. We provide a computational framework to reconstruct

  19. Fe(II)/Cu(II) interaction on goethite stimulated by an iron-reducing bacteria Aeromonas Hydrophila HS01 under anaerobic conditions.

    Science.gov (United States)

    Tao, Liang; Zhu, Zhen-Ke; Li, Fang-Bai; Wang, Shan-Li

    2017-11-01

    Copper is a trace element essential for living creatures, but copper content in soil should be controlled, as it is toxic. The physical-chemical-biological features of Cu in soil have a significant correlation with the Fe(II)/Cu(II) interaction in soil. Of significant interest to the current study is the effect of Fe(II)/Cu(II) interaction conducted on goethite under anaerobic conditions stimulated by HS01 (a dissimilatory iron reduction (DIR) microbial). The following four treatments were designed: HS01 with α-FeOOH and Cu(II) (T1), HS01 with α-FeOOH (T2), HS01 with Cu(II) (T3), and α-FeOOH with Cu(II) (T4). HS01 presents a negligible impact on copper species transformation (T3), whereas the presence of α-FeOOH significantly enhanced copper aging contributing to the DIR effect (T1). Moreover, the violent reaction between adsorbed Fe(II) and Cu(II) leads to the decreased concentration of the active Fe(II) species (T1), further inhibiting reactions between Fe(II) and iron (hydr)oxides and decelerating the phase transformation of iron (hydr)oxides (T1). From this study, the effects of the Fe(II)/Cu(II) interaction on goethite under anaerobic conditions by HS01 are presented in three aspects: (1) the accelerating effect of copper aging, (2) the reductive transformation of copper, and (3) the inhibition effect of the phase transformation of iron (hydr)oxides. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Evaluating the effects of buffer conditions and extremolytes on thermostability of granulocyte colony-stimulating factor using high-throughput screening combined with design of experiments.

    Science.gov (United States)

    Ablinger, Elisabeth; Hellweger, Monika; Leitgeb, Stefan; Zimmer, Andreas

    2012-10-15

    In this study, we combined a high-throughput screening method, differential scanning fluorimetry (DSF), with design of experiments (DoE) methodology to evaluate the effects of several formulation components on the thermostability of granulocyte colony stimulating factor (G-CSF). First we performed a primary buffer screening where we tested thermal stability of G-CSF in different buffers, pH values and buffer concentrations. The significance of each factor and the two-way interactions between them were studied by multivariable regression analysis. pH was identified as most critical factor regarding thermal stability. The most stabilizing buffer, sodium glutamate, and sodium acetate were determined for further investigations. Second we tested the effect of 6 naturally occurring extremolytes (trehalose, sucrose, ectoine, hydroxyectoine, sorbitol, mannitol) on the thermal stability of G-CSF, using a central composite circumscribed design. At low pH (3.8) and low buffer concentration (5 mM) all extremolytes led to a significant increase in thermal stability except the addition of ectoine which resulted in a strong destabilization of G-CSF. Increasing pH and buffer concentration led to an increase in thermal stability with all investigated extremolytes. The described systematic approach allowed to create a ranking of stabilizing extremolytes at different buffer conditions. Copyright © 2012. Published by Elsevier B.V.

  1. Reproduction rates under variable food conditions and starvation in Mnemiopsis leidyi: significance for the invasion success of a ctenophore

    DEFF Research Database (Denmark)

    Jaspers, Cornelia; Møller, Lene Friis; Kiørboe, Thomas

    2015-01-01

    Europe. Furthermore, starved animals continue to produce eggs for up to 12 days after cessation of feeding with high overall hatching success of 65–90%. These life history traits allow M. leidyi to thrive and reproduce in environments with varying food conditions and give it a competitive advantage under...... on the reproduction of laboratory-reared and field-caught animals during starvation. Our results show that the half-saturation zooplankton prey concentration for egg production is reached at food levels of 12–23 µgC L−1, which is below the average summer food concentration encountered in invaded areas of northern...... unfavourable conditions. This may explain why recurrent population blooms are observed and sustained in localized areas in invaded northern Europe, where water exchange is limited and zooplankton food resources are quickly depleted by M. leidyi. We suggest that these reproductive life history traits are key...

  2. A 10-days heatwave around flowering superimposed on climate change conditions significantly affects production of 22 barley accessions

    DEFF Research Database (Denmark)

    Ingvordsen, Cathrine Heinz; Lyngkjær, Michael F.; Peltonen-Sainio, Pirjo

    2015-01-01

    Extreme climate events as heatwaves, floods and storms cause acute changes in season variability influencing primary production and are very likely to increase in magnitude and/or frequency (IPCC, AR5, WGI). In the present study 22 primarily Nordic barley accessions were grown in four basic clima...... climate change conditions on numerous accessions in order to select appropriate genotypes for breeding future cultivars that can secure the primary production....

  3. Computer analysis of the significance of surface boundary conditions on the collection of α-induced charge

    International Nuclear Information System (INIS)

    Terrill, K.W.; Hu, C.; Neureuther, A.R.; California Univ., Berkeley

    1983-01-01

    The collection of α-particle generated charge by collectors surrounded by either uniform reflecting or uniform absorbing surfaces are compared as the two extreme cases of any real condition in IC's. The comparison for varying α-particle energies and collector sizes indicates that the differences in collected charge for the two cases is less than a factor of two if the α-particle strike is through the center of the collector. It is shown that variation of collected charge with feature length is approximately linear in both cases. The effect of scaling on soft errors in static RAM's is discussed. It is assumed that the charge transport is by diffusion only. (author)

  4. Norepinephrine stimulates progesterone production in highly estrogenic bovine granulosa cells cultured under serum-free, chemically defined conditions

    Directory of Open Access Journals (Sweden)

    Piccinato Carla A

    2012-11-01

    Full Text Available Abstract Background Since noradrenergic innervation was described in the ovarian follicle, the actions of the intraovarian catecholaminergic system have been the focus of a variety of studies. We aimed to determine the gonadotropin-independent effects of the catecholamine norepinephrine (NE in the steroid hormone profile of a serum-free granulosa cell (GC culture system in the context of follicular development and dominance. Methods Primary bovine GCs were cultivated in a serum-free, chemically defined culture system supplemented with 0.1% polyvinyl alcohol. The culture features were assessed by hormone measurements and ultrastructural characteristics of GCs. Results GCs produced increasing amounts of estradiol and pregnenolone for 144h and maintained ultrastructural features of healthy steroidogenic cells. Progesterone production was also detected, although it significantly increased only after 96h of culture. There was a highly significant positive correlation between estradiol and pregnenolone production in high E2-producing cultures. The effects of NE were further evaluated in a dose–response study. The highest tested concentration of NE (10 (−7 M resulted in a significant increase in progesterone production, but not in estradiol or pregnenolone production. The specificity of NE effects on progesterone productio n was further investigated by incubating GCs with propranolol (10 (−8 M, a non-selective beta-adrenergic antagonist. Conclusions The present culture system represents a robust model to study the impact of intrafollicular factors, such as catecholamines, in ovarian steroidogenesis and follicular development. The results of noradrenergic effects in the steroidogenesis of GC have implications on physiological follicular fate and on certain pathological ovarian conditions such as cyst formation and anovulation.

  5. Norepinephrine stimulates progesterone production in highly estrogenic bovine granulosa cells cultured under serum-free, chemically defined conditions.

    Science.gov (United States)

    Piccinato, Carla A; Montrezor, Luis H; Collares, Cristhianna A V; Vireque, Alessandra A; Rosa e Silva, Alzira A M

    2012-11-22

    Since noradrenergic innervation was described in the ovarian follicle, the actions of the intraovarian catecholaminergic system have been the focus of a variety of studies. We aimed to determine the gonadotropin-independent effects of the catecholamine norepinephrine (NE) in the steroid hormone profile of a serum-free granulosa cell (GC) culture system in the context of follicular development and dominance. Primary bovine GCs were cultivated in a serum-free, chemically defined culture system supplemented with 0.1% polyvinyl alcohol. The culture features were assessed by hormone measurements and ultrastructural characteristics of GCs. GCs produced increasing amounts of estradiol and pregnenolone for 144h and maintained ultrastructural features of healthy steroidogenic cells. Progesterone production was also detected, although it significantly increased only after 96h of culture. There was a highly significant positive correlation between estradiol and pregnenolone production in high E2-producing cultures. The effects of NE were further evaluated in a dose-response study. The highest tested concentration of NE (10 (-7) M) resulted in a significant increase in progesterone production, but not in estradiol or pregnenolone production. The specificity of NE effects on progesterone production was further investigated by incubating GCs with propranolol (10 (-8) M), a non-selective beta-adrenergic antagonist. The present culture system represents a robust model to study the impact of intrafollicular factors, such as catecholamines, in ovarian steroidogenesis and follicular development. The results of noradrenergic effects in the steroidogenesis of GC have implications on physiological follicular fate and on certain pathological ovarian conditions such as cyst formation and anovulation.

  6. [Conditions required for appearance of a double response to a single-shock stimulation of Schaffer collaterals in hippocampal field CA1 in freely moving rats].

    Science.gov (United States)

    Zosimovskiĭ, V A; Korshunov, V A; Markevich, V A

    2007-01-01

    Schaffer collateral stimulation with a single current impulse can evoke a double response in hippocampal field CA1 of freely moving rats. The late response appears as a population excitatory postsynaptic potential with a preceding short-term potential (frequently biphasic) only after the early population spike and is time-locked to it. The wave shape and polarity of the late response, its latency with respect to the peak of the early population spike suggest that the excitation wave produced in the CA1 field by the stimulation of Schaffer collaterals passes across the entorhinal cortex and returns to the CA1 directly via the perforant path fibers. In waking rat, the medium-intensity stimulation of Schaffer collaterals (able to evoke in the CA1 an early population spike of sufficiently high amplitude) usually does not result in the appearance of the late response. However, similar stimulation becomes efficient after the tetanization of Schaffer collaterals, under conditions of the long-term potentiation of the early population spike. Moreover, the late response occurrence is facilitated in a rat falling asleep after the development in the CA1 of high-amplitude low-frequency EEG oscillations typical for the slow-wave sleep and in a sleeping rat independently of the EEG pattern.

  7. Significance of Mangrove Biodiversity Conservation in Fishery Production and Living Conditions of Coastal Communities in Sri Lanka

    Directory of Open Access Journals (Sweden)

    Chaya Sarathchandra

    2018-03-01

    Full Text Available Sri Lanka is an island nation where ~59% of the population live in coastal regions. The main income source in these areas is fishing, which contributes to ~44% of the national GDP. Fishery resources depend on mangroves, especially in estuaries and lagoons, as mangroves provide the best nursery grounds for both brackish and marine species that are significant for the island’s fishing industry. However, growing pressures from an increasing population and development are causing substantial damage to mangroves resulting in loss of mangrove diversity. We analyzed whether variation in mangrove diversity within a lagoon system affects fishery production and livelihoods. Along the lagoon we selected three sites, which were 5 km apart from each other, for the survey. We used three 50 m long transects at each site for faunal and floral diversity assessments. The fishery catch was recorded from three crafts in each side. The socio-economic survey was conducted in 30 households per site using a standard questionnaire. In the site with the highest floral and faunal diversity, we also recorded the highest fish catch, but not the highest crab or shrimp catches. Our results confirm that higher mangrove diversity—and not just area—supports higher income generation. Thus, future development should prioritize biodiversity conservation in coastal regions.

  8. Combination of retinal pigment epithelium cell-conditioned medium and photoreceptor outer segments stimulate mesenchymal stem cell differentiation toward a functional retinal pigment epithelium cell phenotype.

    Science.gov (United States)

    Huang, Chen; Zhang, Jing; Ao, Mingxin; Li, Ying; Zhang, Chun; Xu, Yonggen; Li, Xuemin; Wang, Wei

    2012-02-01

    Recent studies have suggested that bone marrow-derived mesenchymal stem cells (BMMSCs) are capable of retinal tissue-specific differentiation but not retinal pigment epithelium (RPE) cell-specific differentiation. Photoreceptor outer segments (POS) contribute to RPE development and maturation. However, there has been no standard culture system that fosters the differentiation of BMMSCs into mature RPE cells in vitro. In this study, we investigated if the soluble factors from RPE cells and POS could differentiate BMMSCs into cells having a phenotype characteristic of RPE cells. Rat BMMSCs were separately co-cultured with RPE cells, or they were exposed to either control medium, RPE cell-conditioned medium (RPECM), POS, or a combination of RPECM and POS (RPECM-POS). After 7 days, the cells were analyzed for morphology and the expression of RPE markers (cytokeratin 8, CRALBP, and RPE65) to assess the RPE differentiation. Significantly higher pigment accumulation and increased protein expression of the three markers were seen in cells cultured in RPECM-POS than in other treated cultures. Furthermore, the RPECM-POS-treated cultures displayed ultrastructural features typical of RPE cells, expressed RPE cell functional proteins, and had the capability to phagocytose POS. Together, theses results suggest the combination of RPECM and POS stimulate BMMSCs differentiation toward a functional RPE phenotype. Our results provide the foundation for a new route to RPE regenerative therapy involving BMMSCs. Future work isolating the active agent in RPECM and POS would be useful in therapies for RPE diseases or in developing appropriately pre-differentiated BMMSCs for tissue-engineered RPE reconstruction. Copyright © 2011 Wiley Periodicals, Inc.

  9. Serum Inhibin B and follicle-stimulating hormone levels as tools in the evaluation of infertile men: significance of adequate reference values from proven fertile men

    DEFF Research Database (Denmark)

    Andersson, A.-M.; Petersen, Jørgen Holm; Jørgensen, N.

    2004-01-01

    Inhibin B and FSH levels in 289 idiopathic infertile men were compared with reference materials consisting of 303 proven fertile men (reference group 1) and 307 healthy men from the general population with unknown fertility status (reference group 2). The diagnostic power of these two serum markers...... of spermatogenesis was evaluated by the use of receiver operating characteristic plot analysis, and an example of how both markers can be used simultaneously in a bivariate reference chart is presented. Inhibin B levels were significantly lower and FSH levels were significantly higher in the infertile men, compared...

  10. Stimulation of the Lateral Geniculate, Superior Colliculus, or Visual Cortex is Sufficient for Eyeblink Conditioning in Rats

    Science.gov (United States)

    Halverson, Hunter E.; Hubbard, Erin M.; Freeman, John H.

    2009-01-01

    The role of the cerebellum in eyeblink conditioning is well established. Less work has been done to identify the necessary conditioned stimulus (CS) pathways that project sensory information to the cerebellum. A possible visual CS pathway has been hypothesized that consists of parallel inputs to the pontine nuclei from the lateral geniculate…

  11. Insulin-like growth factor stimulation increases radiosensitivity of a pancreatic cancer cell line through endoplasmic reticulum stress under hypoxic conditions

    International Nuclear Information System (INIS)

    Isohashi, Fumiaki; Endo, Hiroko; Mukai, Mutsuko; Inoue, Masahiro; Inoue, Takehiro

    2008-01-01

    Tumor hypoxia is an obstacle to radiotherapy. Radiosensitivity under hypoxic conditions is determined by molecular oxygen levels, as well as by various biological cellular responses. The insulin-like growth factor (IGF) signaling pathway is a widely recognized survival signal that confers radioresistance. However, under hypoxic conditions the role of IGF signaling in radiosensitivity is still poorly understood. Here, we demonstrate that IGF-II stimulation decreases clonogenic survival under hypoxic conditions in the pancreatic cancer cell lines AsPC-1 and Panc-1, and in the human breast cancer cell line MCF-7. IGF treatment under hypoxic conditions suppressed increased radiation sensitivity in these cell lines by pharmacologically inhibiting the phosphoinositide 3-kinase-mammalian target of rapamycin pathway, a major IGF signal-transduction pathway. Meanwhile, IGF-II induced the endoplasmic reticulum stress response under hypoxia, including increased protein levels of CHOP and ATF4, mRNA levels of CHOP, GADD34, and BiP as well as splicing levels of XBP-1. The response was suppressed by inhibiting phosphoinositide 3-kinase and mammalian target of rapamycin activity. Overexpression of CHOP in AsPC-1 cells increased radiation sensitivity by IGF-II simulation under hypoxic conditions, whereas suppression of CHOP expression levels with small hairpin RNA or a dominant negative form of a proline-rich extensin-like receptor protein kinase in hypoxia decreased IGF-induced radiosensitivity. IGF-induced endoplasmic reticulum stress contributed to radiosensitization independent of cell cycle status. Taken together, IGF stimulation increased radiosensitivity through the endoplasmic reticulum stress response under hypoxic conditions. (author)

  12. Toll-like receptor 6 and connective tissue growth factor are significantly upregulated in mitomycin-C-treated urothelial carcinoma cells under hydrostatic pressure stimulation.

    Science.gov (United States)

    Chen, Shao-Kuan; Chung, Chih-Ang; Cheng, Yu-Che; Huang, Chi-Jung; Chen, Wen-Yih; Ruaan, Ruoh-Chyu; Li, Chuan; Tsao, Chia-Wen; Hu, Wei-Wen; Chien, Chih-Cheng

    2014-06-01

    Urothelial carcinoma (UC) is the most common histologic subtype of bladder cancer. The administration of mitomycin C (MMC) into the bladder after transurethral resection of the bladder tumor (TURBT) is a common treatment strategy for preventing recurrence after surgery. We previously applied hydrostatic pressure combined with MMC in UC cells and found that hydrostatic pressure synergistically enhanced MMC-induced UC cell apoptosis through the Fas/FasL pathways. To understand the alteration of gene expressions in UC cells caused by hydrostatic pressure and MMC, oligonucleotide microarray was used to explore all the differentially expressed genes. After bioinformatics analysis and gene annotation, Toll-like receptor 6 (TLR6) and connective tissue growth factor (CTGF) showed significant upregulation among altered genes, and their gene and protein expressions with each treatment of UC cells were validated by quantitative real-time PCR and immunoblotting. Under treatment with MMC and hydrostatic pressure, UC cells showed increasing apoptosis using extrinsic pathways through upregulation of TLR6 and CTGF.

  13. In vitro stimulation of vascular endothelial growth factor by borate-based glass fibers under dynamic flow conditions.

    Science.gov (United States)

    Chen, Sisi; Yang, Qingbo; Brow, Richard K; Liu, Kun; Brow, Katherine A; Ma, Yinfa; Shi, Honglan

    2017-04-01

    Bioactive borate glass has been recognized to have both hard and soft tissue repair and regeneration capabilities through stimulating both osteogenesis and angiogenesis. However, the underlying biochemical and cellular mechanisms remain unclear. In this study, dynamic flow culturing modules were designed to simulate the micro-environment near the vascular depletion and hyperplasia area in wound-healing regions, thus to better investigate the mechanisms underlying the biocompatibility and functionality of borate-based glass materials. Glass fibers were dosed either upstream or in contact with the pre-seeded cells in the dynamic flow module. Two types of borate glasses, doped with (1605) or without (13-93B3) CuO and ZnO, were studied along with the silicate-based glass, 45S5. Substantial fiber dissolution in cell culture medium was observed, leading to the release of ions (boron, sodium and potassium) and the deposition of a calcium phosphate phase. Different levels of vascular endothelial growth factor secretion were observed from cells exposed to these three glass fibers, and the copper/zinc containing borate 1605 fibers exhibited the most positive influence. These results indicate that dynamic studies of in vitro bioactivity provide useful information to understand the in vivo response to bioactive borate glasses. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Efficacy of kilohertz-frequency and conventional spinal cord stimulation in rat models of different pain conditions.

    Science.gov (United States)

    Song, Zhiyang; Viisanen, Hanna; Meyerson, Björn A; Pertovaara, Antti; Linderoth, Bengt

    2014-04-01

    The aim was to compare the effects of high-frequency spinal cord stimulation (HF-SCS) at subparesthetic intensity with conventional SCS in rat models of different types of pain. In addition, microrecordings of afferent activity in the dorsal columns during both types of SCS were performed to elucidate their mode of action. Miniature SCS electrodes were implanted in all rats. One group was submitted to the spared nerve injury procedure (SNI) and another to inflammatory pain after carrageenan injection into a hind paw. All animals were tested for hypersensitivity to normally innocuous tactile and thermal stimuli. One group of normal healthy rats was submitted to acute nociceptive (pinch, heat) pain. Microrecording of afferent activity in the gracile nucleus (GN) was performed in a group of nerve-lesioned rats responding to conventional SCS. HF-SCS at 500, 1,000, or 10,000 Hz at subparesthetic amplitudes produced similar reductions in hypersensitivity due to nerve lesion as did conventional SCS at 50 Hz. HF-SCS showed no effect on thermal pain. A trial to rescue non-responders to conventional SCS using HF-SCS was not successful. There were no effects either of conventional or of HF-SCS on acute or inflammatory pain. Conventional SCS produced massive activation in the GN but no activation during HF-SCS, though normal peripherally evoked afferent activity remained. Conventional SCS proved equally effective to HF-SCS in various pain models. As no activity is conveyed rostrally in subparesthetic HF-SCS, we hypothesize that its mechanisms of action are primarily segmental. © 2014 International Neuromodulation Society.

  15. Deep brain stimulation of the amygdala alleviates fear conditioning-induced alterations in synaptic plasticity in the cortical-amygdala pathway and fear memory.

    Science.gov (United States)

    Sui, Li; Huang, SiJia; Peng, BinBin; Ren, Jie; Tian, FuYing; Wang, Yan

    2014-07-01

    Deep brain stimulation (DBS) of the amygdala has been demonstrated to modulate hyperactivity of the amygdala, which is responsible for the symptoms of post-traumatic stress disorder (PTSD), and thus might be used for the treatment of PTSD. However, the underlying mechanism of DBS of the amygdala in the modulation of the amygdala is unclear. The present study investigated the effects of DBS of the amygdala on synaptic transmission and synaptic plasticity at cortical inputs to the amygdala, which is critical for the formation and storage of auditory fear memories, and fear memories. The results demonstrated that auditory fear conditioning increased single-pulse-evoked field excitatory postsynaptic potentials in the cortical-amygdala pathway. Furthermore, auditory fear conditioning decreased the induction of paired-pulse facilitation and long-term potentiation, two neurophysiological models for studying short-term and long-term synaptic plasticity, respectively, in the cortical-amygdala pathway. In addition, all these auditory fear conditioning-induced changes could be reversed by DBS of the amygdala. DBS of the amygdala also rescued auditory fear conditioning-induced enhancement of long-term retention of fear memory. These findings suggested that DBS of the amygdala alleviating fear conditioning-induced alterations in synaptic plasticity in the cortical-amygdala pathway and fear memory may underlie the neuromodulatory role of DBS of the amygdala in activities of the amygdala.

  16. Air-drying of cells, the novel conditions for stimulated synthesis of triacylglycerol in a Green Alga, Chlorella kessleri.

    Directory of Open Access Journals (Sweden)

    Takuma Shiratake

    Full Text Available Triacylglycerol is used for the production of commodities including food oils and biodiesel fuel. Microalgae can accumulate triacylglycerol under adverse environmental conditions such as nitrogen-starvation. This study explored the possibility of air-drying of green algal cells as a novel and simple protocol for enhancement of their triacylglycerol content. Chlorella kessleri cells were fixed on the surface of a glass fibre filter and then subjected to air-drying with light illumination. The dry cell weight, on a filter, increased by 2.7-fold in 96 h, the corresponding chlorophyll content ranging from 1.0 to 1.3-fold the initial one. Concomitantly, the triacylglycerol content remarkably increased to 70.3 mole% of fatty acids and 15.9% (w/w, relative to total fatty acids and dry cell weight, respectively, like in cells starved of nitrogen. Reduction of the stress of air-drying by placing the glass filter on a filter paper soaked in H2O lowered the fatty acid content of triacylglycerol to 26.4 mole% as to total fatty acids. Moreover, replacement of the H2O with culture medium further decreased the fatty acid content of triacylglycerol to 12.2 mole%. It thus seemed that severe dehydration is required for full induction of triacylglycerol synthesis, and that nutritional depletion as well as dehydration are crucial environmental factors. Meanwhile, air-drying of Chlamydomonas reinhardtii cells increased the triacylglycerol content to only 37.9 mole% of fatty acids and 4.8% (w/w, relative to total fatty acids and dry cell weight, respectively, and a marked decrease in the chlorophyll content, on a filter, of 33%. Air-drying thus has an impact on triacylglycerol synthesis in C. reinhardtii also, however, the effect is considerably limited, owing probably to instability of the photosynthetic machinery. This air-drying protocol could be useful for the development of a system for industrial production of triacylglycerol with appropriate selection of the

  17. The effects of auditory stimulation on the arithmetic performance of children with ADHD and nondisabled children.

    Science.gov (United States)

    Abikoff, H; Courtney, M E; Szeibel, P J; Koplewicz, H S

    1996-05-01

    This study evaluated the impact of extra-task stimulation on the academic task performance of children with attention-deficit/hyperactivity disorder (ADHD). Twenty boys with ADHD and 20 nondisabled boys worked on an arithmetic task during high stimulation (music), low stimulation (speech), and no stimulation (silence). The music "distractors" were individualized for each child, and the arithmetic problems were at each child's ability level. A significant Group x Condition interaction was found for number of correct answers. Specifically, the nondisabled youngsters performed similarly under all three auditory conditions. In contrast, the children with ADHD did significantly better under the music condition than speech or silence conditions. However, a significant Group x Order interaction indicated that arithmetic performance was enhanced only for those children with ADHD who received music as the first condition. The facilitative effects of salient auditory stimulation on the arithmetic performance of the children with ADHD provide some support for the underarousal/optimal stimulation theory of ADHD.

  18. Clinically significant changes in the emotional condition of relatives of patients with severe traumatic brain injury during sub-acute rehabilitation

    DEFF Research Database (Denmark)

    Norup, Anne; Kristensen, Karin Spangsberg; Poulsen, Ingrid

    2013-01-01

    .2% and 58.1% of relatives had scores above cut-off values on the anxiety and depression scales, respectively. On the anxiety scale 69.7% of these experienced a reliable improvement according to the Reliable Change Index (RCI) and 45.5% also obtained CSC, as their end-point was below the cut-off value...... the Symptom Checklist-90-R (SCL-90-R) when the patients were admitted to sub-acute rehabilitation and at discharge. Improvement in emotional condition was investigated using the following criteria: (i) statistically reliable improvement; and (ii) clinically significant change (CSC). Results: At admission, 53...... in the patients. Conclusion: Of the relatives who reported scores above cut-off values on the anxiety and depression scales at patient's admission, approximately 40% experienced CSC in anxiety and depression during the patient's rehabilitation. Relatives of patients experiencing improvement during inpatient...

  19. Loss of ethanol conditioned taste aversion and motor stimulation in knockin mice with ethanol-insensitive α2-containing GABA(A) receptors.

    Science.gov (United States)

    Blednov, Y A; Borghese, C M; McCracken, M L; Benavidez, J M; Geil, C R; Osterndorff-Kahanek, E; Werner, D F; Iyer, S; Swihart, A; Harrison, N L; Homanics, G E; Harris, R A

    2011-01-01

    GABA type A receptors (GABA(A)-Rs) are potential targets of ethanol. However, there are multiple subtypes of this receptor, and, thus far, individual subunits have not been definitively linked with specific ethanol behavioral actions. Interestingly, though, a chromosomal cluster of four GABA(A)-R subunit genes, including α2 (Gabra2), was associated with human alcoholism (Am J Hum Genet 74:705-714, 2004; Pharmacol Biochem Behav 90:95-104, 2008; J Psychiatr Res 42:184-191, 2008). The goal of our study was to determine the role of receptors containing this subunit in alcohol action. We designed an α2 subunit with serine 270 to histidine and leucine 277 to alanine mutations that was insensitive to potentiation by ethanol yet retained normal GABA sensitivity in a recombinant expression system. Knockin mice containing this mutant subunit were tested in a range of ethanol behavioral tests. These mutant mice did not develop the typical conditioned taste aversion in response to ethanol and showed complete loss of the motor stimulant effects of ethanol. Conversely, they also demonstrated changes in ethanol intake and preference in multiple tests. The knockin mice showed increased ethanol-induced hypnosis but no difference in anxiolytic effects or recovery from acute ethanol-induced motor incoordination. Overall, these studies demonstrate that the effects of ethanol at GABAergic synapses containing the α2 subunit are important for specific behavioral effects of ethanol that may be relevant to the genetic linkage of this subunit with human alcoholism.

  20. Loss of Ethanol Conditioned Taste Aversion and Motor Stimulation in Knockin Mice with Ethanol-Insensitive α2-Containing GABAA Receptors

    Science.gov (United States)

    Borghese, C. M.; McCracken, M. L.; Benavidez, J. M.; Geil, C. R.; Osterndorff-Kahanek, E.; Werner, D. F.; Iyer, S.; Swihart, A.; Harrison, N. L.; Homanics, G. E.; Harris, R. A.

    2011-01-01

    GABA type A receptors (GABAA-Rs) are potential targets of ethanol. However, there are multiple subtypes of this receptor, and, thus far, individual subunits have not been definitively linked with specific ethanol behavioral actions. Interestingly, though, a chromosomal cluster of four GABAA-R subunit genes, including α2 (Gabra2), was associated with human alcoholism (Am J Hum Genet 74:705–714, 2004; Pharmacol Biochem Behav 90:95–104, 2008; J Psychiatr Res 42:184–191, 2008). The goal of our study was to determine the role of receptors containing this subunit in alcohol action. We designed an α2 subunit with serine 270 to histidine and leucine 277 to alanine mutations that was insensitive to potentiation by ethanol yet retained normal GABA sensitivity in a recombinant expression system. Knockin mice containing this mutant subunit were tested in a range of ethanol behavioral tests. These mutant mice did not develop the typical conditioned taste aversion in response to ethanol and showed complete loss of the motor stimulant effects of ethanol. Conversely, they also demonstrated changes in ethanol intake and preference in multiple tests. The knockin mice showed increased ethanol-induced hypnosis but no difference in anxiolytic effects or recovery from acute ethanol-induced motor incoordination. Overall, these studies demonstrate that the effects of ethanol at GABAergic synapses containing the α2 subunit are important for specific behavioral effects of ethanol that may be relevant to the genetic linkage of this subunit with human alcoholism. PMID:20876231

  1. NF-κB activity in muscle from obese and type 2 diabetic subjects under basal and exercise-stimulated conditions.

    Science.gov (United States)

    Tantiwong, Puntip; Shanmugasundaram, Karthigayan; Monroy, Adriana; Ghosh, Sangeeta; Li, Mengyao; DeFronzo, Ralph A; Cersosimo, Eugenio; Sriwijitkamol, Apiradee; Mohan, Sumathy; Musi, Nicolas

    2010-11-01

    NF-κB is a transcription factor that controls the gene expression of several proinflammatory proteins. Cell culture and animal studies have implicated increased NF-κB activity in the pathogenesis of insulin resistance and muscle atrophy. However, it is unclear whether insulin-resistant human subjects have abnormal NF-κB activity in muscle. The effect that exercise has on NF-κB activity/signaling also is not clear. We measured NF-κB DNA-binding activity and the mRNA level of putative NF-κB-regulated myokines interleukin (IL)-6 and monocyte chemotactic protein-1 (MCP-1) in muscle samples from T2DM, obese, and lean subjects immediately before, during (40 min), and after (210 min) a bout of moderate-intensity cycle exercise. At baseline, NF-κB activity was elevated 2.1- and 2.7-fold in obese nondiabetic and T2DM subjects, respectively. NF-κB activity was increased significantly at 210 min following exercise in lean (1.9-fold) and obese (2.6-fold) subjects, but NF-κB activity did not change in T2DM. Exercise increased MCP-1 mRNA levels significantly in the three groups, whereas IL-6 gene expression increased significantly only in lean and obese subjects. MCP-1 and IL-6 gene expression peaked at the 40-min exercise time point. We conclude that insulin-resistant subjects have increased basal NF-κB activity in muscle. Acute exercise stimulates NF-κB in muscle from nondiabetic subjects. In T2DM subjects, exercise had no effect on NF-κB activity, which could be explained by the already elevated NF-κB activity at baseline. Exercise-induced MCP-1 and IL-6 gene expression precedes increases in NF-κB activity, suggesting that other factors promote gene expression of these cytokines during exercise.

  2. Biochemical acclimation, stomatal limitation and precipitation patterns underlie decreases in photosynthetic stimulation of soybean (Glycine max) at elevated [CO₂] and temperatures under fully open air field conditions.

    Science.gov (United States)

    Rosenthal, David M; Ruiz-Vera, Ursula M; Siebers, Matthew H; Gray, Sharon B; Bernacchi, Carl J; Ort, Donald R

    2014-09-01

    The net effect of elevated [CO2] and temperature on photosynthetic acclimation and plant productivity is poorly resolved. We assessed the effects of canopy warming and fully open air [CO2] enrichment on (1) the acclimation of two biochemical parameters that frequently limit photosynthesis (A), the maximum carboxylation capacity of Rubisco (Vc,max) and the maximum potential linear electron flux through photosystem II (Jmax), (2) the associated responses of leaf structural and chemical properties related to A, as well as (3) the stomatal limitation (l) imposed on A, for soybean over two growing seasons in a conventionally managed agricultural field in Illinois, USA. Acclimation to elevated [CO2] was consistent over two growing seasons with respect to Vc,max and Jmax. However, elevated temperature significantly decreased Jmax contributing to lower photosynthetic stimulation by elevated CO2. Large seasonal differences in precipitation altered soil moisture availability modulating the complex effects of elevated temperature and CO2 on biochemical and structural properties related to A. Elevated temperature also reduced the benefit of elevated [CO2] by eliminating decreases in stomatal limitation at elevated [CO2]. These results highlight the critical importance of considering multiple environmental factors (i.e. temperature, moisture, [CO2]) when trying to predict plant productivity in the context of climate change. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  3. Amount of prenatal visual stimulation alters incubation times and postnatal preferences in leopard geckos (Eublepharis macularius).

    Science.gov (United States)

    Sleigh, M J; Birchard, G F

    2001-09-01

    The authors exposed gecko (Eublepharis macularius) embryos to patterned visual stimulation beginning at either 1 week or 2 weeks prior to hatching. Embryos exposed to the substantially augmented amount of prenatal visual stimulation hatched significantly earlier than the embryos either exposed to the moderately augmented prenatal visual stimulation or not exposed to any prenatal visual stimulation (p geckos in all conditions failed to exhibit a preference for either stimulus.

  4. Comparing the Efficacy of Excitatory Transcranial Stimulation Methods Measuring Motor Evoked Potentials

    Directory of Open Access Journals (Sweden)

    Vera Moliadze

    2014-01-01

    Full Text Available The common aim of transcranial stimulation methods is the induction or alterations of cortical excitability in a controlled way. Significant effects of each individual stimulation method have been published; however, conclusive direct comparisons of many of these methods are rare. The aim of the present study was to compare the efficacy of three widely applied stimulation methods inducing excitability enhancement in the motor cortex: 1 mA anodal transcranial direct current stimulation (atDCS, intermittent theta burst stimulation (iTBS, and 1 mA transcranial random noise stimulation (tRNS within one subject group. The effect of each stimulation condition was quantified by evaluating motor-evoked-potential amplitudes (MEPs in a fixed time sequence after stimulation. The analyses confirmed a significant enhancement of the M1 excitability caused by all three types of active stimulations compared to sham stimulation. There was no significant difference between the types of active stimulations, although the time course of the excitatory effects slightly differed. Among the stimulation methods, tRNS resulted in the strongest and atDCS significantly longest MEP increase compared to sham. Different time courses of the applied stimulation methods suggest different underlying mechanisms of action. Better understanding may be useful for better targeting of different transcranial stimulation techniques.

  5. 3 Tesla MRI of patients with a vagus nerve stimulator: initial experience using a T/R head coil under controlled conditions.

    Science.gov (United States)

    Gorny, Krzysztof R; Bernstein, Matt A; Watson, Robert E

    2010-02-01

    To assess safety of clinical MRI of the head in patients with implanted model 100, 102, and 103 vagus nerve stimulation (VNS) Therapy Systems (Cyberonics, Inc., Houston, TX) in 3.0 Tesla MRI (GE Healthcare, Milwaukee, WI). The distributions of the radiofrequency B(1) (+)-field produced by the clinically used transmit/receive (T/R) head coil (Advanced Imaging Research Incorporated, Cleveland, OH) and body coil were measured in a head and shoulders phantom. These measurements were supplemented by temperature measurements on the lead tips and the implantable pulse generator (IPG) of the VNS devices in a head and torso phantom with the same two coils. Clinical 3T MRI head scans were then acquired under highly controlled conditions in a series of 17 patients implanted with VNS. Phantom studies showed only weak B(1) (+) fields at the location of the VNS IPG and leads for MRI scans using the T/R head coil. The MRI-related heating on a VNS scanned in vitro at 3T was also found to be minimal (0.4-0.8 degrees C at the leads, negligible at the IPG). The patient MRI examinations were completed successfully without any adverse incidents. No patient reported any heating, discomfort, or any other unusual sensation. Safe clinical MRI head scanning of patients with implanted VNS is shown to be feasible on a GE Signa Excite 3T MRI system using one specific T/R head coil. These results apply to this particular MRI system configuration. Extrapolation or generalization of these results to more general or less controlled imaging situations without supporting data of safety is highly discouraged.

  6. The Codacs™ direct acoustic cochlear implant actuator: exploring alternative stimulation sites and their stimulation efficiency.

    Science.gov (United States)

    Grossöhmichen, Martin; Salcher, Rolf; Kreipe, Hans-Heinrich; Lenarz, Thomas; Maier, Hannes

    2015-01-01

    This work assesses the efficiency of the Codacs system actuator (Cochlear Ltd., Sydney Australia) in different inner ear stimulation modalities. Originally the actuator was intended for direct perilymph stimulation after stapedotomy using a piston prosthesis. A possible alternative application is the stimulation of middle ear structures or the round window (RW). Here the perilymph stimulation with a K-piston through a stapes footplate (SFP) fenestration (N = 10) as well as stimulation of the stapes head (SH) with a Bell prosthesis (N = 9), SFP stimulation with an Omega/Aerial prosthesis (N = 8) and reverse RW stimulation (N = 10) were performed in cadaveric human temporal bones (TBs). Codacs actuator output is expressed as equivalent sound pressure level (eq. SPL) using RW and SFP displacement responses, measured by Laser Doppler velocimetry as reference. The axial actuator coupling force in stimulation of stapes and RW was adjusted to ~5 mN. The Bell prosthesis and Omega/Aerial prosthesis stimulation generated similar mean eq. SPLs (Bell: 127.5-141.8 eq. dB SPL; Omega/Aerial: 123.6-143.9 eq. dB SPL), being significantly more efficient than K-piston perilymph stimulation (108.6-131.6 eq. dB SPL) and RW stimulation (108.3-128.2 eq. dB SPL). Our results demonstrate that SH, SFP and RW are adequate alternative stimulation sites for the Codacs actuator using coupling prostheses and an axial coupling force of ~5 mN. Based on the eq. SPLs, all investigated methods were adequate for in vivo hearing aid applications, provided that experimental conditions including constant coupling force will be implemented.

  7. The Codacs™ direct acoustic cochlear implant actuator: exploring alternative stimulation sites and their stimulation efficiency.

    Directory of Open Access Journals (Sweden)

    Martin Grossöhmichen

    Full Text Available This work assesses the efficiency of the Codacs system actuator (Cochlear Ltd., Sydney Australia in different inner ear stimulation modalities. Originally the actuator was intended for direct perilymph stimulation after stapedotomy using a piston prosthesis. A possible alternative application is the stimulation of middle ear structures or the round window (RW. Here the perilymph stimulation with a K-piston through a stapes footplate (SFP fenestration (N = 10 as well as stimulation of the stapes head (SH with a Bell prosthesis (N = 9, SFP stimulation with an Omega/Aerial prosthesis (N = 8 and reverse RW stimulation (N = 10 were performed in cadaveric human temporal bones (TBs. Codacs actuator output is expressed as equivalent sound pressure level (eq. SPL using RW and SFP displacement responses, measured by Laser Doppler velocimetry as reference. The axial actuator coupling force in stimulation of stapes and RW was adjusted to ~5 mN. The Bell prosthesis and Omega/Aerial prosthesis stimulation generated similar mean eq. SPLs (Bell: 127.5-141.8 eq. dB SPL; Omega/Aerial: 123.6-143.9 eq. dB SPL, being significantly more efficient than K-piston perilymph stimulation (108.6-131.6 eq. dB SPL and RW stimulation (108.3-128.2 eq. dB SPL. Our results demonstrate that SH, SFP and RW are adequate alternative stimulation sites for the Codacs actuator using coupling prostheses and an axial coupling force of ~5 mN. Based on the eq. SPLs, all investigated methods were adequate for in vivo hearing aid applications, provided that experimental conditions including constant coupling force will be implemented.

  8. Comparative estimation of inevitable endogenous ileal flow of amino acids in Pekin ducks under varying dietary or physiological conditions and their significance to nutritional requirements for amino acids.

    Science.gov (United States)

    Akinde, D O

    2017-10-01

    In 2 experiments in Pekin ducks the inevitable endogenous ileal flow (IEIF) of AA was estimated at changing intake and source of crude fiber (CF) or soybean oil (SO) level. Also the roles of dry matter intake (DMI) and BW or age as well as the proportion of IEIF in the dietary requirement for AA were studied. In experiment 1 three basal CP (20, 60, or 100 g/kg) diets were formulated containing a low CF (LCF, 30 g/kg) or high (HCF, 80 g/kg) level; achieved with cellulose supplementation. All diets were similar in every other respect including having SO content of 40 g/kg. Four floor pens of eight 85-day-old ducks were randomly allocated to each diet. Similar diets were mixed in experiment 2 but corn cob meal replaced cellulose as the fiber source. A high SO (HSO) series was also formed by increasing the SO level from 40 g/kg in the basal series to 100 g/kg. Thus the LCF series was concurrently classified as low SO (LSO) series to control SO effect. Each of the eventual 9 diets were fed to 5 floor pens of ten 65-day-old ducks. Ileal AA flow was measured after a 5 day feeding period in both experiments. Linear regression was calculated between ileal flow and dietary intake of individual AA. The IEIF interpreted as the y-intercept of each linear function responded neither to elevated ingestion of each CF type nor to SO level. Age and DMI had no effect on IEIF computed in relation to BW, but wide discrepancies resulted when related to DMI. Overall IEIF of AA varied between 14.3 to 129.8 mg/kg BW d-1. These flows were established in model computations to account for 10 to 64% of the recommended intake of limiting AA. In conclusion the ileal inevitable flow is constant within the dietary/age conditions investigated. However it is modulated by feed intake and accounts for a significant portion of total amino acid requirement. © 2017 Poultry Science Association Inc.

  9. Effects of electric stimulation of the hunger center in the lateral hypothalamus on slow electric activity and spike activity of fundal and antral stomach muscles in rabbits under conditions of hunger and satiation.

    Science.gov (United States)

    Kromin, A A; Zenina, O Yu

    2013-09-01

    In chronic experiments on rabbits, the effect of electric stimulation of the hunger center in the lateral hypothalamus on myoelectric activity of the fundal and antral parts of the stomach was studied under conditions of hunger and satiation in the absence of food. Stimulation of the lateral hypothalamus in rabbits subjected to 24-h food deprivation and in previously fed rabbits produced incessant seeking behavior, which was followed by reorganization of the structure of temporal organization of slow wave electric activity of muscles of the stomach body and antrum specific for hungry and satiated animals. Increased hunger motivation during electric stimulation of the lateral hypothalamus manifested in the structure of temporal organization of slow wave electric activity of the stomach body and antrum muscles in rabbits subjected to 24-h food deprivation in the replacement of bimodal distribution of slow wave periods to a trimodal type typical of 2-day deprivation, while transition from satiation to hunger caused by electric stimulation of the lateral hypothalamus was associated with a shift from monomodal distributions of slow wave periods to a bimodal type typical of 24-h deprivation. Reorganization of the structure of temporal organization of slow wave electric activity of the stomach body and antrum muscles during electric stimulation of the lateral hypothalamus was determined by descending inhibitory influences of food motivational excitation on activity of the myogenic pacemaker of the lesser curvature of the stomach.

  10. Efeito de giberelina (GA3 e do bioestimulante 'Stimulate' na indução floral e produtividade do maracujazeiro-amarelo em condições de safra normal Effect of gibereline (GA3 and biostimulant 'Stimulate' in floral induction and yield of yellow passion fruit in conditions of normal growing season

    Directory of Open Access Journals (Sweden)

    Elma Machado Ataíde

    2006-12-01

    Full Text Available O objetivo do trabalho foi avaliar os efeitos de GA3, nas concentrações de 100; 200 e 300mg L-1 e do bioestimulante Stimulate®, em doses de 2,08; 4,17 e 6,25mL L-1, em duas aplicações via foliar, acrescidas de espalhante adesivo Silwett® a 0,05% e a exposição dos ramos à luminosidade, na indução floral e produtividade do maracujazeiro-amarelo, em condições de safra normal, em Araguari-MG. Aos 30 dias após a primeira aplicação dos tratamentos, iniciaram-se as avaliações do número de flores, com contagens diárias, nos dois lados da espaldeira, nos meses de setembro de 2002 a março de 2003. As colheitas dos frutos foram realizadas semanalmente, no período de novembro de 2002 a abril de 2003, observando-se a produção. O GA3 e o Stimulate não proporcionaram efeito significativo no número de flores, nas sete épocas, assim como no número total de flores. Não houve efeito dos tratamentos para a produtividade e produção total de frutos. Os ramos sob luminosidade pela tarde apresentaram maior número de flores, nos meses de setembro, dezembro, fevereiro e março. A interação entre os tratamentos e a exposição dos ramos à luminosidade não foi significativa para o número de flores, nas épocas avaliadas.The objective of this work was to evaluate the effects of GA3 , in concentrations of 100, 200 and 300mg L-1 and biostimulant StimulateTM, in doses of 2,08, 4,17 and 6,25 mL L-1, in two leaf applications, added with the adhesive spreader SilwettTM at 0,05% and branch exposure to brightness, on passion fruit in floral induction and yield, in conditions of normal growing season, in Araguari-MG. At 30 days after the first treatment application, the evaluation of flower number started, with daily counts, in both sides of the plants, from September 2002 to March 2003. Fruit harvest was realized weekly from November 2002 to April 2003, being observed the yield. GA3 and Stimulate did not provide significant effect on flower

  11. Calmodulin protects cells from death under normal growth conditions and mitogenic starvation but plays a mediating role in cell death upon B-cell receptor stimulation

    DEFF Research Database (Denmark)

    Schmalzigaug, R; Ye, Q; Berchtold, M W

    2001-01-01

    stimulation of the B-cell receptor (BCR), the resting Ca2+ levels remain elevated after the initial transient in CaMII-/- cells. Despite higher Ca2+ resting levels, the CaMII-/- cells are partially protected from BCR induced apoptosis indicating that CaM plays a dual role in apoptotic processes....

  12. Fetal stimulation by pulsed diagnostic ultrasound.

    Science.gov (United States)

    Fatemi, M; Ogburn, P L; Greenleaf, J F

    2001-08-01

    To show that pulsed ultrasound from a clinical ultrasonic imaging system can stimulate the fetus. Stimulation is defined mainly as increased fetal gross body movements in response to excitation. Fetuses of a group of 9 volunteer women (mean gestational age, 33.37 weeks; range, 25-40 weeks) were evaluated for body movement under 3 different conditions: (1) control, with no ultrasound exposure; (2) ultrasound in continuous wave Doppler mode; and (3) pulsed ultrasound in pulsed Doppler and B modes. A conventional external fetal monitor, with negligible ultrasonic output, was used to monitor fetal gross body motions. After an initial rest period of 3 minutes with 1 or no fetal motion, fetuses were monitored for an additional 3 minutes under the exposure criterion defined for each condition. Resulting fetal motions under the 3 conditions were compared using the Wilcoxon signed rank test. The test showed that fetuses moved significantly more frequently under condition 3 (mean +/- SD, 3.43 +/- 1.93 movements per minute) than under condition 1 (0.40 +/- 7.33 movements per minute) or condition 2 (0.63 +/- 7.67 movements per minute); P = .004 and .016, respectively. Fetal movements under conditions 1 and 2 did not differ significantly. Diagnostic ultrasound may stimulate fetal body motion.

  13. Transcriptional and metabolic regulation of denitrification in Paracoccus denitrificans allows low but significant activity of nitrous oxide reductase under oxic conditions.

    Science.gov (United States)

    Qu, Zhi; Bakken, Lars R; Molstad, Lars; Frostegård, Åsa; Bergaust, Linda L

    2016-09-01

    Oxygen is known to repress denitrification at the transcriptional and metabolic levels. It has been a common notion that nitrous oxide reductase (N2 OR) is the most sensitive enzyme among the four N-oxide reductases involved in denitrification, potentially leading to increased N2 O production under suboxic or fluctuating oxygen conditions. We present detailed gas kinetics and transcription patterns from batch culture experiments with Paracoccus denitrificans, allowing in vivo estimation of e(-) -flow to O2 and N2 O under various O2 regimes. Transcription of nosZ took place concomitantly with that of narG under suboxic conditions, whereas transcription of nirS and norB was inhibited until O2 levels approached 0 μM in the liquid. Catalytically functional N2 OR was synthesized and active in aerobically raised cells transferred to vials with 7 vol% O2 in headspace, but N2 O reduction rates were 10 times higher when anaerobic pre-cultures were subjected to the same conditions. Upon oxygen exposure, there was an incomplete and transient inactivation of N2 OR that could be ascribed to its lower ability to compete for electrons compared with terminal oxidases. The demonstrated reduction of N2 O at high O2 partial pressure and low N2 O concentrations by a bacterium not known as a typical aerobic denitrifier may provide one clue to the understanding of why some soils appear to act as sinks rather than sources for atmospheric N2 O. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  14. Music acupuncture stimulation method.

    Science.gov (United States)

    Brătilă, F; Moldovan, C

    2007-01-01

    Harmonic Medicine is the model using the theory that the body rhythms synchronize to an outer rhythm applied for therapeutic purpose, can restores the energy balance in acupuncture channels and organs and the condition of well-being. The purpose of this scientific work was to demonstrate the role played by harmonic sounds in the stimulation of the Lung (LU) Meridian (Shoutaiyin Feijing) and of the Kidney (KI) Meridian (Zushaoyin Shenjing). It was used an original method that included: measurement and electronic sound stimulation of the Meridian Entry Point, measurement of Meridian Exit Point, computer data processing, bio feed-back adjustment of the music stimulation parameters. After data processing, it was found that the sound stimulation of the Lung Meridian Frequency is optimal between 122 Hz and 128 Hz, with an average of 124 Hz (87% of the subjects) and for Kidney Meridian from 118 Hz to 121 Hz, with an average of 120 Hz (67% of the subjects). The acupuncture stimulation was more intense for female subjects (> 7%) than for the male ones. We preliminarily consider that an informational resonance phenomenon can be developed between the acupuncture music stimulation frequency and the cellular dipole frequency, being a really "resonant frequency signature" of an acupoint. The harmonic generation and the electronic excitation or low-excitation status of an acupuncture point may be considered as a resonance mechanism. By this kind of acupunctural stimulation, a symphony may act and play a healer role.

  15. growth stimulant

    African Journals Online (AJOL)

    Effects of timing and duration of supplementation of LIVFIT VET ® (growth stimulant) as substitute for fish meal on the growth performance, haematology and clinical enzymes concentration of growing pigs.

  16. Significance of heat-moisture treatment conditions on the pasting and gelling behaviour of various starch-rich cereal and pseudocereal flours.

    Science.gov (United States)

    Collar, Concha

    2017-10-01

    The impact of heat-moisture treatment processing conditions (15%, 25%, and 35% moisture content; 1, 3, and 5 h heating time at 120 ℃) on the viscosity pasting and gelling profiles of different grain flours matrices (barley, buckwheat, sorghum, high β-glucan barley, and wheat) was investigated by applying successive cooking and cooling cycles to rapid visco analyser canisters with highly hydrated samples (3.5:25, w:w). At a milder heat-moisture treatment conditions (15% moisture content, 1 h heating time), except for sorghum, heat-moisture treatment flours reached much higher viscosity values during earlier pasting and subsequent gelling than the corresponding native counterparts. Besides heat-moisture treatment wheat flour, the described behaviour found also for non-wheat-treated flours has not been previously reported in the literature. An increased hydrophobicity of prolamins and glutelins in low moisture-short heating time heat-moisture treatment of non-wheat flours with high protein content (12.92%-19.95%) could explain the enhanced viscosity profile observed.

  17. Clinically significant changes in the emotional condition of relatives of patients with severe traumatic brain injury during sub-acute rehabilitation

    DEFF Research Database (Denmark)

    Norup, Anne; Kristensen, Karin Spangsberg; Poulsen, Ingrid

    2013-01-01

    . On the depression scale the corresponding figures were 44.4% and 41.7%, respectively. When comparing relatives with and without CSC, we found that CSC in symptoms of anxiety was associated with significantly better functional improvement during rehabilitation and a shorter period of post-traumatic amnesia...

  18. Is transcranial direct current stimulation a potential method for improving response inhibition?

    Science.gov (United States)

    Kwon, Yong Hyun; Kwon, Jung Won

    2013-04-15

    Inhibitory control of movement in motor learning requires the ability to suppress an inappropriate action, a skill needed to stop a planned or ongoing motor response in response to changes in a variety of environments. This study used a stop-signal task to determine whether transcranial direct-current stimulation over the pre-supplementary motor area alters the reaction time in motor inhibition. Forty healthy subjects were recruited for this study and were randomly assigned to either the transcranial direct-current stimulation condition or a sham-transcranial direct-current stimulation condition. All subjects consecutively performed the stop-signal task before, during, and after the delivery of anodal transcranial direct-current stimulation over the pre-supplementary motor area (pre-transcranial direct-current stimulation phase, transcranial direct-current stimulation phase, and post-transcranial direct-current stimulation phase). Compared to the sham condition, there were significant reductions in the stop-signal processing times during and after transcranial direct-current stimulation, and change times were significantly greater in the transcranial direct-current stimulation condition. There was no significant change in go processing-times during or after transcranial direct-current stimulation in either condition. Anodal transcranial direct-current stimulation was feasibly coupled to an interactive improvement in inhibitory control. This coupling led to a decrease in the stop-signal process time required for the appropriate responses between motor execution and inhibition. However, there was no transcranial direct-current stimulation effect on the no-signal reaction time during the stop-signal task. Transcranial direct-current stimulation can adjust certain behaviors, and it could be a useful clinical intervention for patients who have difficulties with response inhibition.

  19. The significance of climate change in the Netherlands. An analysis of historical and future trends (1901-2020) in weather conditions, weather extremes and temperature-related impacts

    Energy Technology Data Exchange (ETDEWEB)

    Visser, H.

    2005-07-01

    A rigorous statistical analysis reveals changes in Dutch climate that are statistically significant over the last century. Annually averaged temperatures have increased by 1.5 about 0.5 degrees Centigrade; the number of summer days has roughly doubled from 14 about 5 to 27 about 9 days; annual precipitation has increased by 120 about 100 mm; and the number of extremely wet days has increased by about 40%, from 19 about 3 to 26 about 3 days. Several other changes in Dutch climate, such as spring temperatures rising more rapidly than winter temperatures, the increase of the coldest temperature in each year by 0.9 degrees Centigrade and the annual maximum day sum of precipitation, turn out to be not (yet) statistically significant. The changes in Dutch climate have already led to several statistically significant impacts. The length of the growing season has increased by nearly a month, and the number of heating-degree days, a measure for the energy needed for the heating of houses and buildings, has decreased by 14 about 5%. Projections of future temperature increase in 2020 based on the statistical analysis closely resemble projections based on climate models: temperatures continue to increase from 10.4 about 0.4 degrees Centigrade in 2003 to 10.7 about 0.6 degrees Centigrade in 2010 and 11.1 about 1.0 degrees Centigrade in 2020. The energy needed for heating of houses and buildings is expected to decrease further. This warming effect is expected to lower projections of future Dutch greenhouse-gas emissions by 3.5 Mton CO2 equivalents, which is relevant in the context of commitments under the Kyoto Protocol. Finally, over the course of the 20th century the chance on an 'Elfstedentocht', an outdoor skating event in the Netherlands, has decreased from once every five years to once every ten years. Even though this impact change is not yet statistically significant, it resides 'on the edge' of significance: within a few years more evidence may

  20. Transcranial Direct Current Stimulation Improves Audioverbal Memory in Stroke Patients.

    Science.gov (United States)

    Kazuta, Toshinari; Takeda, Kotaro; Osu, Rieko; Tanaka, Satoshi; Oishi, Ayako; Kondo, Kunitsugu; Liu, Meigen

    2017-08-01

    The aim of this study was to investigate whether anodal transcranial direct current stimulation over the left temporoparietal area improved audioverbal memory performance in stroke patients. Twelve stroke patients with audioverbal memory impairment participated in a single-masked, crossover, and sham-controlled experiment. The anodal or sham transcranial direct current stimulation was applied during the Rey Auditory Verbal Learning Test, which evaluates the ability to recall a list of 15 heard words over five trials. The number of correctly recalled words was compared between the anodal and sham conditions and the influence of transcranial direct current stimulation on serial position effect of the 15 words was also examined. The increase in the number of correctly recalled words from the first to the fifth trial was significantly greater in the anodal condition than in the sham condition (P transcranial direct current stimulation over the left temporoparietal area improved audioverbal memory performance and induced the primacy effect in stroke patients.

  1. Optimization of Submerged Cultivation Conditions for Production of Big Cup Culinary-Medicinal Mushroom Clitocybe maxima (Agaricomycetes) Biomass with Significant Antioxidative and Antihyperlipidemic Activities.

    Science.gov (United States)

    Hu, Shu-Hui; Chen, Ker-Shew; Liu, Ming-Yi; Cheung, Peter Chi Keung; Wang, Jinn-Chyi; Chang, Sue-Joan

    2017-01-01

    In this study, a large Clitocybe maxima mycelium biomass was obtained by submerged cultivation under optimal conditions. Three test samples from lyophilized mycelia, including hot water extract (CW) and elutes from solvents with different polarity (CA and CB), were combined and used to explore antioxidant and antihyper-lipidemic activities in vitro and in vivo. The CA group showed the highest DPPH free radical scavenging activity and iron-reducing capability at concentrations of 6.0% and 3.0% (w/v), respectively. Further, the CA group showed the highest glutathione peroxidase and superoxide dismutase activities at a dose of 0.25 mg/kg body weight (CA-0.25 group) in all hyperlipidemic hamsters tested. Serum lipid levels (apart from high-density lipoprotein cholesterol levels) of hamsters in the CA-0.25 group were lower than those of hamsters in the negative control group in antihy-perlipidemic tests. Therefore, we believe that extracts from C. maxima mycelia are rich reservoirs of antioxidant and antihyperlipidemic activities.

  2. An Evaluation of the Significance of Work-Related Influence Factors on Fitness and the Development of Medical and Orthopaedic Conditions in Military Executives

    Directory of Open Access Journals (Sweden)

    Christoph Schulze

    2016-01-01

    Full Text Available Occupational health promotion is an effective tool to improve the state of health of employees. As part of occupational health promotion in the German Bundeswehr, top-ranking military executives are offered a medical examination and training programme. Health-related data is collected as a basis for training and lifestyle counselling. This data was subjected to a retrospective evaluation in order to identify occupational risk factors and their correlation with cardiovascular resilience, trunk strength, and the development of orthopaedic and internal disorders. A total of 122 military executives (all male, age 54.6±4.2 years answered a questionnaire aimed at evaluating private and occupational stress factors. The medical history was followed by a medical and orthopaedic examination involving a lactate performance test (treadmill or bicycle ergometry and an isometric trunk strength measurement. The data obtained was then statistically evaluated. For military executives, work-related travelling and commuting involve a high risk of medical and orthopaedic conditions. Regular exercise leads to improved fitness levels. In order to prevent medical problems, military executives working long hours should regularly take part in fitness and weight training under professional instructions.

  3. Efficient detection of human circulating tumor cells without significant production of false-positive cells by a novel conditionally replicating adenovirus

    Directory of Open Access Journals (Sweden)

    Fuminori Sakurai

    2016-01-01

    Full Text Available Circulating tumor cells (CTCs are promising biomarkers in several cancers, and thus methods and apparatuses for their detection and quantification in the blood have been actively pursued. A novel CTC detection system using a green fluorescence protein (GFP–expressing conditionally replicating adenovirus (Ad (rAd-GFP was recently developed; however, there is concern about the production of false-positive cells (GFP-positive normal blood cells when using rAd-GFP, particularly at high titers. In addition, CTCs lacking or expressing low levels of coxsackievirus–adenovirus receptor (CAR cannot be detected by rAd-GFP, because rAd-GFP is constructed based on Ad serotype 5, which recognizes CAR. In order to suppress the production of false-positive cells, sequences perfectly complementary to blood cell–specific microRNA, miR-142-3p, were incorporated into the 3′-untranslated region of the E1B and GFP genes. In addition, the fiber protein was replaced with that of Ad serotype 35, which recognizes human CD46, creating rAdF35-142T-GFP. rAdF35-142T-GFP efficiently labeled not only CAR-positive tumor cells but also CAR-negative tumor cells with GFP. The numbers of false-positive cells were dramatically lower for rAdF35-142T-GFP than for rAd-GFP. CTCs in the blood of cancer patients were detected by rAdF35-142T-GFP with a large reduction in false-positive cells.

  4. Electrical stimulation of the midbrain excites the auditory cortex asymmetrically.

    Science.gov (United States)

    Quass, Gunnar Lennart; Kurt, Simone; Hildebrandt, Jannis; Kral, Andrej

    2018-05-17

    Auditory midbrain implant users cannot achieve open speech perception and have limited frequency resolution. It remains unclear whether the spread of excitation contributes to this issue and how much it can be compensated by current-focusing, which is an effective approach in cochlear implants. The present study examined the spread of excitation in the cortex elicited by electric midbrain stimulation. We further tested whether current-focusing via bipolar and tripolar stimulation is effective with electric midbrain stimulation and whether these modes hold any advantage over monopolar stimulation also in conditions when the stimulation electrodes are in direct contact with the target tissue. Using penetrating multielectrode arrays, we recorded cortical population responses to single pulse electric midbrain stimulation in 10 ketamine/xylazine anesthetized mice. We compared monopolar, bipolar, and tripolar stimulation configurations with regard to the spread of excitation and the characteristic frequency difference between the stimulation/recording electrodes. The cortical responses were distributed asymmetrically around the characteristic frequency of the stimulated midbrain region with a strong activation in regions tuned up to one octave higher. We found no significant differences between monopolar, bipolar, and tripolar stimulation in threshold, evoked firing rate, or dynamic range. The cortical responses to electric midbrain stimulation are biased towards higher tonotopic frequencies. Current-focusing is not effective in direct contact electrical stimulation. Electrode maps should account for the asymmetrical spread of excitation when fitting auditory midbrain implants by shifting the frequency-bands downward and stimulating as dorsally as possible. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. Temporal lobe cortical electrical stimulation during the encoding and retrieval phase reduces false memories.

    Directory of Open Access Journals (Sweden)

    Paulo S Boggio

    Full Text Available A recent study found that false memories were reduced by 36% when low frequency repetitive transcranial magnetic stimulation (rTMS was applied to the left anterior temporal lobe after the encoding (study phase. Here we were interested in the consequences on a false memory task of brain stimulation throughout the encoding and retrieval task phases. We used transcranial direct current stimulation (tDCS because it has been shown to be a useful tool to enhance cognition. Specifically, we examined whether tDCS can induce changes in a task assessing false memories. Based on our preliminary results, three conditions of stimulation were chosen: anodal left/cathodal right anterior temporal lobe (ATL stimulation ("bilateral stimulation"; anodal left ATL stimulation (with a large contralateral cathodal electrode--referred as "unilateral stimulation" and sham stimulation. Our results showed that false memories were reduced significantly after the two active conditions (unilateral and bilateral stimulation as compared with sham stimulation. There were no significant changes in veridical memories. Our findings show that false memories are reduced by 73% when anodal tDCS is applied to the anterior temporal lobes throughout the encoding and retrieval stages, suggesting a possible strategy for improving certain aspects of learning.

  6. Brain Stimulation Therapies

    Science.gov (United States)

    ... Magnetic Seizure Therapy Deep Brain Stimulation Additional Resources Brain Stimulation Therapies Overview Brain stimulation therapies can play ... for a shorter recovery time than ECT Deep Brain Stimulation Deep brain stimulation (DBS) was first developed ...

  7. Subliminal Stimulation: Hoax or Reality?

    Science.gov (United States)

    Trank, Douglas M.

    Subliminal stimulation is defined as that which is perceived by an individual below the threshold of awareness or cognizance. This article traces the history of research in subliminal stimulation to illustrate that under certain circumstances and conditions, this behavioral phenomenon does occur. Although subliminal stimuli do affect human…

  8. Repetitive Transcranial Magnetic Stimulation Improved Symptoms of Obsessive-Compulsive Disorder, but Also Cognitive Performance: Results from a Randomized Clinical Trial with a Cross-Over Design and Sham Condition.

    Science.gov (United States)

    Jahangard, Leila; Haghighi, Mohammad; Shyayganfard, Mehran; Ahmadpanah, Mohammad; Sadeghi Bahmani, Dena; Bajoghli, Hafez; Holsboer-Trachsler, Edith; Brand, Serge

    2016-01-01

    There is some evidence that repetitive transcranial magnetic stimulation (rTMS) is an effective method of treating patients suffering from obsessive-compulsive disorder (OCD). Here, we tested the hypothesis that rTMS has a positive impact both on symptom severity and cognitive performance in such patients. Specifically, short-term verbal processing speed and flexibility were assessed. Ten patients suffering from refractory OCD and treated with standard medication were randomly assigned either to a treatment-first or to a sham-first condition. At baseline and after 2 and 4 weeks, symptom severity (experts' ratings) and cognitive performance (auditory perception, visual perception, short-term memory, and processing speed) were assessed. After 2 weeks, the treatment condition switched to the sham condition, and the sham condition switched to the treatment condition. Under treatment but not under sham conditions, symptom severity reduced. Moreover, cognitive performance improved in parallel. rTMS is a safe and efficient treatment for patients suffering from refractory OCD; symptoms and cognitive performance improved in parallel. © 2016 S. Karger AG, Basel.

  9. Computationally Developed Sham Stimulation Protocol for Multichannel Desynchronizing Stimulation

    Directory of Open Access Journals (Sweden)

    Magteld Zeitler

    2018-05-01

    Full Text Available A characteristic pattern of abnormal brain activity is abnormally strong neuronal synchronization, as found in several brain disorders, such as tinnitus, Parkinson's disease, and epilepsy. As observed in several diseases, different therapeutic interventions may induce a placebo effect that may be strong and hinder reliable clinical evaluations. Hence, to distinguish between specific, neuromodulation-induced effects and unspecific, placebo effects, it is important to mimic the therapeutic procedure as precisely as possibly, thereby providing controls that actually lack specific effects. Coordinated Reset (CR stimulation has been developed to specifically counteract abnormally strong synchronization by desynchronization. CR is a spatio-temporally patterned multichannel stimulation which reduces the extent of coincident neuronal activity and aims at an anti-kindling, i.e., an unlearning of both synaptic connectivity and neuronal synchrony. Apart from acute desynchronizing effects, CR may cause sustained, long-lasting desynchronizing effects, as already demonstrated in pre-clinical and clinical proof of concept studies. In this computational study, we set out to computationally develop a sham stimulation protocol for multichannel desynchronizing stimulation. To this end, we compare acute effects and long-lasting effects of six different spatio-temporally patterned stimulation protocols, including three variants of CR, using a no-stimulation condition as additional control. This is to provide an inventory of different stimulation algorithms with similar fundamental stimulation parameters (e.g., mean stimulation rates but qualitatively different acute and/or long-lasting effects. Stimulation protocols sharing basic parameters, but inducing nevertheless completely different or even no acute effects and/or after-effects, might serve as controls to validate the specific effects of particular desynchronizing protocols such as CR. In particular, based on

  10. Effects of oral and gastric stimulation on appetite and energy intake.

    Science.gov (United States)

    Wijlens, Anne G M; Erkner, Alfrun; Alexander, Erin; Mars, Monica; Smeets, Paul A M; de Graaf, Cees

    2012-11-01

    Appetite is regulated by many factors, including oro-sensory and gastric signals. There are many studies on contributions of and possible interaction between sensory and gastric stimulation, but there are few studies in humans using simultaneous oral and gastric stimulation. We investigated the effect of simultaneous, but independently manipulated, oral and gastric stimulation on appetite ratings and energy intake. We hypothesized that compared with no stimulation, oral and gastric stimulation would equally and additively decrease appetite ratings and energy intake. Healthy men (n = 26, 21 ± 2 years, BMI 22 ± 3 kg/m(2)) participated in a randomized crossover trial with four experimental conditions and a control condition. Experimental conditions consisted of oral stimulation, with either 1 or 8 min modified sham feeding (MSF), and gastric stimulation, with either 100 or 800 ml intragastrically infused liquid (isocaloric, 99 kcal, 100 ml/min). The control condition consisted of no oral or gastric stimulation. Outcome measures were energy intake 30 min after the treatment and appetite ratings. Compared with the control condition, energy intake decreased significantly after the 8 min/100 ml (19% lower, P = 0.001) and 8 min/800 ml conditions (15% lower, P = 0.02), but not after the 1 min/100 ml (14% lower, P = 0.06) and 1 min/800 ml conditions (10% lower, P = 0.39). There was no interaction of oral and gastric stimulation on energy intake. Hunger and fullness differed across all conditions (P ≤ 0.01). In conclusion, duration of oral exposure was at least as important in decreasing energy intake as gastric filling volume. Oral and gastric stimulation did not additively decrease energy intake. Longer oro-sensory stimulation, therefore, may be an important contributor to a lower energy intake.

  11. Effectiveness of transcutaneous electrical nerve stimulation on saliva production in post-radiated oral cancer patients

    Directory of Open Access Journals (Sweden)

    Sakshi Ojha

    2016-01-01

    Full Text Available Aims and Objectives: To determine the effectiveness of transcutaneous electrical nerve stimulation (TENS in stimulating salivary flow in post-radiated oral cancer patients, and to compare the salivary flow rate between unstimulated saliva and saliva stimulated with TENS in post-radiated oral cancer patients. Materials and Methods: In 30 patients who underwent radiotherapy for oral cancer, unstimulated saliva was collected every minute for 5 min in a graduated test tube. The TENS unit was activated and stimulated saliva was collected for 5 min in a separate graduated test tube, and the flow rate was compared with the unstimulated salivary flow rate. Results: A statistically significant improvement was seen in saliva production during stimulation (P < 0.001. In addition, statistically significant increase in TENS stimulated saliva was observed in patients aged ≥50 years compared to that in patients aged <50 years (P < 0.05. There was no significant difference in salivary flow rate between the two genders in both stimulated and unstimulated conditions, however, statistically significant increase in salivary flow rate was observed in males under stimulated condition (P < 0.01. Conclusion: TENS was highly effective in stimulating the whole salivary flow rate in post-radiated oral cancer patients. It is an effective supportive treatment modality in xerostomia patients caused by radiotherapy in oral cancer patients.

  12. Stimulation of protein synthesis by internalized insulin

    International Nuclear Information System (INIS)

    Miller, D.S.; Sykes, D.B.

    1991-01-01

    Previous studies showed that microinjected insulin stimulates transcription and translation in Stage 4 Xenopus oocytes by acting at nuclear and cytoplasmic sites. The present report is concerned with the question of whether hormone, internalized from an external medium, can act on those sites to alter cell function. Both intracellular accumulation of undegraded 125I-insulin and insulin-stimulated 35S-methionine incorporation into oocyte protein were measured. Anti-insulin antiserum and purified anti-insulin antibody were microinjected into the cytoplasm of insulin-exposed cells to determine if insulin derived from the medium acted through internal sites. In cells exposed for 2 h to 7 or 70 nM external insulin, methionine incorporation was stimulated, but intracellular hormone accumulation was minimal and microinjected antibody was without effect. In cells exposed for 24 h, methionine incorporation again increased, but now accumulation of undegraded, intracellular hormone was substantial (2.6 and 25.3 fmol with 7 and 70 nM, respectively), and microinjected anti-insulin antibody significantly reduced the insulin-stimulated component of incorporation; basal incorporation was not affected. For cells exposed to 70 nM insulin for 24 h, inhibition of the insulin-stimulated component was maximal at 39%. Thus under those conditions, about 40% of insulin's effects were mediated by the internal sites. Together, the data show that inhibition of insulin-stimulated protein synthesis by microinjected antibody was associated with the intracellular accumulation of insulin. They indicate that when oocytes are exposed to external insulin, hormone eventually gains access to intracellular sites of action and through these stimulates translation. Control of translation appears to be shared between the internal sites and the surface receptor

  13. Conditioning pain stimulation does not affect itch induced by intra-epidermal histamine pricks but aggravates neurogenic inflammation in healthy volunteers

    DEFF Research Database (Denmark)

    Andersen, Hjalte Holm; Imai, Yosuke; Petersen, Kristian Kjær

    2016-01-01

    This study investigated whether itch induced by intra-epidermal histamine is subjected to modulation by a standardized conditioned pain modulation (CPM) paradigm in 24 healthy volunteers. CPM was induced by computer-controlled cuff pressure algometry and histamine was introduced to the volar...... forearm by skin prick test punctures. Moreover, neurogenic inflammation and wheal reactions induced by histamine and autonomic nervous system responses (heart rate variability and skin conductance) were monitored. CPM did not modulate the intensity of histamine-induced itch suggesting that pruriceptive...... signaling is not inhibited by pain-recruited endogenous modulation, however, CPM was found to aggravate histamine-induced neurogenic inflammation, likely facilitated by efferent sympathetic fibers....

  14. Hematopoietic stem cell cytokines and fibroblast growth factor-2 stimulate human endothelial cell-pericyte tube co-assembly in 3D fibrin matrices under serum-free defined conditions.

    Directory of Open Access Journals (Sweden)

    Annie O Smith

    Full Text Available We describe a novel 3D fibrin matrix model using recombinant hematopoietic stem cell cytokines under serum-free defined conditions which promotes the assembly of human endothelial cell (EC tubes with co-associated pericytes. Individual ECs and pericytes are randomly mixed together and EC tubes form that is accompanied by pericyte recruitment to the EC tube abluminal surface over a 3-5 day period. These morphogenic processes are stimulated by a combination of the hematopoietic stem cell cytokines, stem cell factor, interleukin-3, stromal derived factor-1α, and Flt-3 ligand which are added in conjunction with fibroblast growth factor (FGF-2 into the fibrin matrix. In contrast, this tube morphogenic response does not occur under serum-free defined conditions when VEGF and FGF-2 are added together in the fibrin matrices. We recently demonstrated that VEGF and FGF-2 are able to prime EC tube morphogenic responses (i.e. added overnight prior to the morphogenic assay to hematopoietic stem cell cytokines in collagen matrices and, interestingly, they also prime EC tube morphogenesis in 3D fibrin matrices. EC-pericyte interactions in 3D fibrin matrices leads to marked vascular basement membrane assembly as demonstrated using immunofluorescence and transmission electron microscopy. Furthermore, we show that hematopoietic stem cell cytokines and pericytes stimulate EC sprouting in fibrin matrices in a manner dependent on the α5β1 integrin. This novel co-culture system, under serum-free defined conditions, allows for a molecular analysis of EC tube assembly, pericyte recruitment and maturation events in a critical ECM environment (i.e. fibrin matrices that regulates angiogenic events in postnatal life.

  15. Do changes in spinal reflex excitability elicited by transcranial magnetic stimulation differ based on the site of cerebellar stimulation?

    Science.gov (United States)

    Matsugi, Akiyoshi

    2018-05-06

    The present study aimed to investigate whether spinal reflex excitability is influenced by the site of cerebellar transcranial magnetic stimulation (C-TMS). Fourteen healthy volunteers (mean age: 24.6 ± 6.6 years [11 men]) participated. Participants lay on a bed in the prone position, with both ankle joints fixed to prevent unwanted movement. Right tibial nerve stimulation was provided to elicit the H-reflex in the right soleus muscle. Conditioning transcranial magnetic stimulation (TMS) was delivered at one of the following sites 110 ms prior to tibial stimulation: right, central, or left cerebellum; midline parietal (Pz) region; or sham stimulation. A total of 10 test trials were included for each condition, in random order. The unconditioned and conditioned H-reflexes were measured during random inter-test trials, and the cerebellar spinal facilitation (CSpF) ratios for each site were calculated (the ratio of conditioned to unconditioned H-reflexes). CSpF ratios were compared among TMS sites. CSpF ratios were significantly higher at cerebellar sites than at the Pz site or during sham stimulation. However, there was no significant difference in CSpF ratio among cerebellar sites. TMS conditioning over any part of the cerebellum facilitated the excitability of the spinal motoneuron pool. Facilitation of the H-reflex due to C-TMS may involve the effects of the bilateral descending tract of the spinal cord on the spinal motoneuron pool. Alternatively, direct brainstem stimulation may have activated portions of the bilateral descending tract of the spinal cord.

  16. Kinetic analysis and modeling of oleate and ethanol stimulated uranium (VI) bio-reduction in contaminated sediments under sulfate reduction conditions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Fan, E-mail: zhangfan@itpcas.ac.cn [Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Wu Weimin [Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305 (United States); Parker, Jack C. [Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Mehlhorn, Tonia [Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Kelly, Shelly D.; Kemner, Kenneth M. [Biosciences Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Zhang, Gengxin [Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Schadt, Christopher; Brooks, Scott C. [Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Criddle, Craig S. [Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305 (United States); Watson, David B. [Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Jardine, Philip M. [Biosystems Engineering and Soil Science Department, University of Tennessee, Knoxville, TN 37996 (United States)

    2010-11-15

    Microcosm tests with uranium contaminated sediments were performed to explore the feasibility of using oleate as a slow-release electron donor for U(VI) reduction in comparison to ethanol. Oleate degradation proceeded more slowly than ethanol with acetate produced as an intermediate for both electron donors under a range of initial sulfate concentrations. A kinetic microbial reduction model was developed and implemented to describe and compare the reduction of sulfate and U(VI) with oleate or ethanol. The reaction path model considers detailed oleate/ethanol degradation and the production and consumption of intermediates, acetate and hydrogen. Although significant assumptions are made, the model tracked the major trend of sulfate and U(VI) reduction and describes the successive production and consumption of acetate, concurrent with microbial reduction of aqueous sulfate and U(VI) species. The model results imply that the overall rate of U(VI) bioreduction is influenced by both the degradation rate of organic substrates and consumption rate of intermediate products.

  17. Kinetic analysis and modeling of oleate and ethanol stimulated uranium (VI) bio-reduction in contaminated sediments under sulfate reduction conditions

    International Nuclear Information System (INIS)

    Zhang Fan; Wu Weimin; Parker, Jack C.; Mehlhorn, Tonia; Kelly, Shelly D.; Kemner, Kenneth M.; Zhang, Gengxin; Schadt, Christopher; Brooks, Scott C.; Criddle, Craig S.; Watson, David B.; Jardine, Philip M.

    2010-01-01

    Microcosm tests with uranium contaminated sediments were performed to explore the feasibility of using oleate as a slow-release electron donor for U(VI) reduction in comparison to ethanol. Oleate degradation proceeded more slowly than ethanol with acetate produced as an intermediate for both electron donors under a range of initial sulfate concentrations. A kinetic microbial reduction model was developed and implemented to describe and compare the reduction of sulfate and U(VI) with oleate or ethanol. The reaction path model considers detailed oleate/ethanol degradation and the production and consumption of intermediates, acetate and hydrogen. Although significant assumptions are made, the model tracked the major trend of sulfate and U(VI) reduction and describes the successive production and consumption of acetate, concurrent with microbial reduction of aqueous sulfate and U(VI) species. The model results imply that the overall rate of U(VI) bioreduction is influenced by both the degradation rate of organic substrates and consumption rate of intermediate products.

  18. Adults with an epilepsy history fare significantly worse on positive mental and physical health than adults with other common chronic conditions-Estimates from the 2010 National Health Interview Survey and Patient Reported Outcome Measurement System (PROMIS) Global Health Scale.

    Science.gov (United States)

    Kobau, Rosemarie; Cui, Wanjun; Zack, Matthew M

    2017-07-01

    Healthy People 2020, a national health promotion initiative, calls for increasing the proportion of U.S. adults who self-report good or better health. The Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health Scale (GHS) was identified as a reliable and valid set of items of self-reported physical and mental health to monitor these two domains across the decade. The purpose of this study was to examine the percentage of adults with an epilepsy history who met the Healthy People 2020 target for self-reported good or better health and to compare these percentages to adults with history of other common chronic conditions. Using the 2010 National Health Interview Survey, we compared and estimated the age-standardized prevalence of reporting good or better physical and mental health among adults with five selected chronic conditions including epilepsy, diabetes, heart disease, cancer, and hypertension. We examined response patterns for physical and mental health scale among adults with these five conditions. The percentages of adults with epilepsy who reported good or better physical health (52%) or mental health (54%) were significantly below the Healthy People 2020 target estimate of 80% for both outcomes. Significantly smaller percentages of adults with an epilepsy history reported good or better physical health than adults with heart disease, cancer, or hypertension. Significantly smaller percentages of adults with an epilepsy history reported good or better mental health than adults with all other four conditions. Health and social service providers can implement and enhance existing evidence-based clinical interventions and public health programs and strategies shown to improve outcomes in epilepsy. These estimates can be used to assess improvements in the Healthy People 2020 Health-Related Quality of Life and Well-Being Objective throughout the decade. Published by Elsevier Inc.

  19. Novel transcranial magnetic stimulation coil for mice

    Science.gov (United States)

    March, Stephen; Stark, Spencer; Crowther, Lawrence; Hadimani, Ravi; Jiles, David

    2014-03-01

    Transcranial magnetic stimulation (TMS) shows potential for non-invasive treatment of various neurological disorders. Significant work has been performed on the design of coils used for TMS on human subjects but few reports have been made on the design of coils for use on the brains of animals such as mice. This work is needed as TMS studies utilizing mice can allow rapid preclinical development of TMS for human disorders but the coil designs developed for use on humans are inadequate for optimal stimulation of the much smaller mouse brain. A novel TMS coil has been developed with the goal of inducing strong and focused electric fields for the stimulation of small animals such as mice. Calculations of induced electric fields were performed utilizing an MRI derived inhomogeneous model of an adult male mouse. Mechanical and thermal analysis of this new TMS helmet-coil design have also been performed at anticipated TMS operating conditions to ensure mechanical stability of the new coil and establish expected linear attraction and rotational force values. Calculated temperature increases for typical stimulation periods indicate the helmet-coil system is capable of operating within established medical standards. A prototype of the coil has been fabricated and characterization results are presented.

  20. Unilateral prefrontal direct current stimulation effects are modulated by working memory load and gender.

    Science.gov (United States)

    Meiron, Oded; Lavidor, Michal

    2013-05-01

    Recent studies revealed that anodal transcranial direct current stimulation (tDCS) to the left dorsolateral prefrontal cortex (DLPFC) may improve verbal working memory (WM) performance in humans. In the present study, we evaluated executive attention, which is the core of WM capacity, considered to be significantly involved in tasks that require active maintenance of memory representations in interference-rich conditions, and is highly dependent on DLPFC function. We investigated verbal WM accuracy using a WM task that is highly sensitive to executive attention function. We were interested in how verbal WM accuracy may be affected by WM load, unilateral DLPFC stimulation, and gender, as previous studies showed gender-dependent brain activation during verbal WM tasks. We utilized a modified verbal n-Back task hypothesized to increase demands on executive attention. We examined "online" WM performance while participants received transcranial direct current stimulation (tDCS), and implicit learning performance in a post-stimulation WM task. Significant lateralized "online" stimulation effects were found only in the highest WM load condition revealing that males benefit from left DLPFC stimulation, while females benefit from right DLPFC stimulation. High WM load performance in the left DLPFC stimulation was significantly related to post-stimulation recall performance. Our findings support the idea that lateralized stimulation effects in high verbal WM load may be gender-dependent. Further, our post-stimulation results support the idea that increased left hemisphere activity may be important for encoding verbal information into episodic memory as well as for facilitating retrieval of context-specific targets from semantic memory. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Spectral characteristics of light sources for S-cone stimulation.

    Science.gov (United States)

    Schlegelmilch, F; Nolte, R; Schellhorn, K; Husar, P; Henning, G; Tornow, R P

    2002-11-01

    Electrophysiological investigations of the short-wavelength sensitive pathway of the human eye require the use of a suitable light source as a S-cone stimulator. Different light sources with their spectral distribution properties were investigated and compared with the ideal S-cone stimulator. First, the theoretical background of the calculation of relative cone energy absorption from the spectral distribution function of the light source is summarized. From the results of the calculation, the photometric properties of the ideal S-cone stimulator will be derived. The calculation procedure was applied to virtual light sources (computer generated spectral distribution functions with different medium wavelengths and spectrum widths) and to real light sources (blue and green light emitting diodes, blue phosphor of CRT-monitor, multimedia projector, LCD monitor and notebook display). The calculated relative cone absorbencies are compared to the conditions of an ideal S-cone stimulator. Monochromatic light sources with wavelengths of less than 456 nm are close to the conditions of an ideal S-cone stimulator. Spectrum widths up to 21 nm do not affect the S-cone activation significantly (S-cone activation change < 0.2%). Blue light emitting diodes with peak wavelength at 448 nm and spectrum bandwidth of 25 nm are very useful for S-cone stimulation (S-cone activation approximately 95%). A suitable display for S-cone stimulation is the Trinitron computer monitor (S-cone activation approximately 87%). The multimedia projector has a S-cone activation up to 91%, but their spectral distribution properties depends on the selected intensity. LCD monitor and notebook displays have a lower S-cone activation (< or = 74%). Carefully selecting the blue light source for S-cone stimulation can reduce the unwanted L-and M-cone activation down to 4% for M-cones and 1.5% for L-cones.

  2. Spinal Cord Stimulation

    DEFF Research Database (Denmark)

    Meier, Kaare

    2014-01-01

    Spinal cord stimulation (SCS) is a surgical treatment for chronic neuropathic pain that is refractory to other treatment. Originally described by Shealy et al. in 1967(1), it is used to treat a range of conditions such as complex regional pain syndrome (CRPS I)(2), angina pectoris(3), radicular...... pain after failed back surgery syndrome (FBSS)(4), pain due to peripheral nerve injury, stump pain(5), peripheral vascular disease(6) and diabetic neuropathy(7,8); whereas phantom pain(9), postherpetic neuralgia(10), chronic visceral pain(11), and pain after partial spinal cord injury(12) remain more...

  3. Gastric secretion elicited by conditioning in rats.

    Science.gov (United States)

    Caboclo, José Liberato Ferreira; Cury, Francico de Assis; Borin, Aldenis Albanese; Caboclo, Luís Otávio Sales Ferreira; Ribeiro, Maria Fernanda Sales Caboclo; de Freitas, Pedro José; Andersson, Sven

    2009-01-01

    To investigate whether interdigestive gastric acid secretion can be controlled by a possible memory-related cortical mechanism. To evaluate gastric secretion in rats, we used a methodology that allows gastric juice collection in rats in their habitual conditions (without any restraining) by pairing sound as the conditioning stimulus (CS) and food as the unconditioning stimulus (US). The levels of gastric acid secretion under basal conditions and under sound stimulation were recorded and the circulating gastrin levels determined. When the gastric juice was collected in the course of the conditioning procedure, the results showed that under noise stimulation a significant increase in gastric acid secretion occurred after 10 days of conditioning (p<0.01). The significance was definitively demonstrated after 13 days of conditioning (p<0.001). Basal secretions of the conditioned rats reached a significant level after 16 days of conditioning. The levels of noise-stimulated gastric acid secretion were the highest so far described in physiological experiments carried out in rats and there were no significant increases in the circulating gastrin levels. The results point to the important role played by cortical structures in the control of interdigestive gastric acid secretion in rats. If this mechanism is also present in humans, it may be involved in diseases caused by inappropriate gastric acid secretion during the interprandial periods.

  4. The glucagon-like peptide 1 analogue Exendin-4 attenuates the nicotine-induced locomotor stimulation, accumbal dopamine release, conditioned place preference as well as the expression of locomotor sensitization in mice.

    Directory of Open Access Journals (Sweden)

    Emil Egecioglu

    Full Text Available The gastrointestinal peptide glucagon-like peptide 1 (GLP-1 is known to regulate consummatory behavior and is released in response to nutrient ingestion. Analogues of this peptide recently emerged as novel pharmacotherapies for treatment of type II diabetes since they reduce gastric emptying, glucagon secretion as well as enhance glucose-dependent insulin secretion. The findings that GLP-1 targets reward related areas including mesolimbic dopamine areas indicate that the physiological role of GLP-1 extends beyond food intake and glucose homeostasis control to include reward regulation. The present series of experiments was therefore designed to investigate the effects of the GLP-1 receptor agonist, Exendin-4 (Ex4, on established nicotine-induced effects on the mesolimbic dopamine system in mice. Specifically, we show that treatment with Ex4, at a dose with no effect per se, attenuate nicotine-induced locomotor stimulation, accumbal dopamine release as well as the expression of conditioned place preference in mice. In accordance, Ex4 also blocks nicotine-induced expression of locomotor sensitization in mice. Given that development of nicotine addiction largely depends on the effects of nicotine on the mesolimbic dopamine system these findings indicate that the GLP-1 receptor may be a potential target for the development of novel treatment strategies for nicotine cessations in humans.

  5. Cerebellar transcranial static magnetic field stimulation transiently reduces cerebellar brain inhibition.

    Science.gov (United States)

    Matsugi, Akiyoshi; Okada, Y

    The aim of this study was to investigate whether transcranial static magnetic field stimulation (tSMS) delivered using a compact cylindrical NdFeB magnet over the cerebellum modulates the excitability of the cerebellum and contralateral primary motor cortex, as measured using cerebellar brain inhibition (CBI), motor evoked potentials (MEPs), and resting motor threshold (rMT). These parameters were measured before tSMS or sham stimulation and immediately, 5 minutes and 10 minutes after stimulation. There were no significant changes in CBI, MEPs or rMT over time in the sham stimulation condition, and no changes in MEPs or rMT in the tSMS condition. However, CBI was significantly decreased immediately after tSMS as compared to that before and 5 minutes after tSMS. Our results suggest that tSMS delivered to the cerebellar hemisphere transiently reduces cerebellar inhibitory output but does not affect the excitability of the contralateral motor cortex.

  6. Effects of intermittent theta burst stimulation on cerebral blood flow and cerebral vasomotor reactivity.

    Science.gov (United States)

    Pichiorri, Floriana; Vicenzini, Edoardo; Gilio, Francesca; Giacomelli, Elena; Frasca, Vittorio; Cambieri, Chiara; Ceccanti, Marco; Di Piero, Vittorio; Inghilleri, Maurizio

    2012-08-01

    To determine whether intermittent theta burst stimulation influences cerebral hemodynamics, we investigated changes induced by intermittent theta burst stimulation on the middle cerebral artery cerebral blood flow velocity and vasomotor reactivity to carbon dioxide (CO(2)) in healthy participants. The middle cerebral artery flow velocity and vasomotor reactivity were monitored by continuous transcranial Doppler sonography. Changes in cortical excitability were tested by transcranial magnetic stimulation. In 11 healthy participants, before and immediately after delivering intermittent theta burst stimulation, we tested cortical excitability measured by the resting motor threshold and motor evoked potential amplitude over the stimulated hemisphere and vasomotor reactivity to CO(2) bilaterally. The blood flow velocity was monitored in both middle cerebral arteries throughout the experimental session. In a separate session, we tested the effects of sham stimulation under the same experimental conditions. Whereas the resting motor threshold remained unchanged before and after stimulation, motor evoked potential amplitudes increased significantly (P = .04). During and after stimulation, middle cerebral artery blood flow velocities also remained bilaterally unchanged, whereas vasomotor reactivity to CO(2) increased bilaterally (P = .04). The sham stimulation left all variables unchanged. The expected intermittent theta burst stimulation-induced changes in cortical excitability were not accompanied by changes in cerebral blood flow velocities; however, the bilateral increased vasomotor reactivity suggests that intermittent theta burst stimulation influences the cerebral microcirculation, possibly involving subcortical structures. These findings provide useful information on hemodynamic phenomena accompanying intermittent theta burst stimulation, which should be considered in research aimed at developing this noninvasive, low-intensity stimulation technique for safe

  7. Modulation of Total Sleep Time by Transcranial Direct Current Stimulation (tDCS).

    Science.gov (United States)

    Frase, Lukas; Piosczyk, Hannah; Zittel, Sulamith; Jahn, Friederike; Selhausen, Peter; Krone, Lukas; Feige, Bernd; Mainberger, Florian; Maier, Jonathan G; Kuhn, Marion; Klöppel, Stefan; Normann, Claus; Sterr, Annette; Spiegelhalder, Kai; Riemann, Dieter; Nitsche, Michael A; Nissen, Christoph

    2016-09-01

    Arousal and sleep are fundamental physiological processes, and their modulation is of high clinical significance. This study tested the hypothesis that total sleep time (TST) in humans can be modulated by the non-invasive brain stimulation technique transcranial direct current stimulation (tDCS) targeting a 'top-down' cortico-thalamic pathway of sleep-wake regulation. Nineteen healthy participants underwent a within-subject, repeated-measures protocol across five nights in the sleep laboratory with polysomnographic monitoring (adaptation, baseline, three experimental nights). tDCS was delivered via bi-frontal target electrodes and bi-parietal return electrodes before sleep (anodal 'activation', cathodal 'deactivation', and sham stimulation). Bi-frontal anodal stimulation significantly decreased TST, compared with cathodal and sham stimulation. This effect was location specific. Bi-frontal cathodal stimulation did not significantly increase TST, potentially due to ceiling effects in good sleepers. Exploratory resting-state EEG analyses before and after the tDCS protocols were consistent with the notion of increased cortical arousal after anodal stimulation and decreased cortical arousal after cathodal stimulation. The study provides proof-of-concept that TST can be decreased by non-invasive bi-frontal anodal tDCS in healthy humans. Further elucidating the 'top-down' pathway of sleep-wake regulation is expected to increase knowledge on the fundamentals of sleep-wake regulation and to contribute to the development of novel treatments for clinical conditions of disturbed arousal and sleep.

  8. Comparing the force ripple during asynchronous and conventional stimulation.

    Science.gov (United States)

    Downey, Ryan J; Tate, Mark; Kawai, Hiroyuki; Dixon, Warren E

    2014-10-01

    Asynchronous stimulation has been shown to reduce fatigue during electrical stimulation; however, it may also exhibit a force ripple. We quantified the ripple during asynchronous and conventional single-channel transcutaneous stimulation across a range of stimulation frequencies. The ripple was measured during 5 asynchronous stimulation protocols, 2 conventional stimulation protocols, and 3 volitional contractions in 12 healthy individuals. Conventional 40 Hz and asynchronous 16 Hz stimulation were found to induce contractions that were as smooth as volitional contractions. Asynchronous 8, 10, and 12 Hz stimulation induced contractions with significant ripple. Lower stimulation frequencies can reduce fatigue; however, they may also lead to increased ripple. Future efforts should study the relationship between force ripple and the smoothness of the evoked movements in addition to the relationship between stimulation frequency and NMES-induced fatigue to elucidate an optimal stimulation frequency for asynchronous stimulation. © 2014 Wiley Periodicals, Inc.

  9. Evoked Electromyographically Controlled Electrical Stimulation

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Hayashibe

    2016-07-01

    Full Text Available Time-variant muscle responses under electrical stimulation (ES are often problematic for all the applications of neuroprosthetic muscle control. This situation limits the range of ES usage in relevant areas, mainly due to muscle fatigue and also to changes in stimulation electrode contact conditions, especially in transcutaneous ES. Surface electrodes are still the most widely used in noninvasive applications.Electrical field variations caused by changes in the stimulation contact condition markedly affect the resulting total muscle activation levels. Fatigue phenomena under functional electrical stimulation (FES are also well known source of time-varying characteristics coming from muscle response under ES. Therefore it is essential to monitor the actual muscle state and assess the expected muscle response by ES so as to improve the current ES system in favour of adaptive muscle-response-aware FES control. To deal with this issue, we have been studying a novel control technique using evoked electromyography (eEMG signals to compensate for these muscle time-variances under ES for stable neuroprosthetic muscle control. In this perspective article, I overview the background of this topic and highlight important points to be aware of when using ES to induce the desired muscle activation regardless of the time-variance. I also demonstrate how to deal with the common critical problem of ES to move toward robust neuroprosthetic muscle control with the Evoked Electromyographically Controlled Electrical Stimulation paradigm.

  10. Galvanic vestibular stimulation may improve anterior bending posture in Parkinson's disease.

    Science.gov (United States)

    Okada, Yohei; Kita, Yorihiro; Nakamura, Junji; Kataoka, Hiroshi; Kiriyama, Takao; Ueno, Satoshi; Hiyamizu, Makoto; Morioka, Shu; Shomoto, Koji

    2015-05-06

    This study investigated the effects of binaural monopolar galvanic vestibular stimulation (GVS), which likely stimulates the bilateral vestibular system, on the anterior bending angle in patients with Parkinson's disease (PD) with anterior bending posture in a single-blind, randomized sham-controlled crossover trial. The seven PD patients completed two types of stimulation (binaural monopolar GVS and sham stimulation) applied in a random order 1 week apart. We measured each patient's anterior bending angles while he or she stood with eyes open and eyes closed before/after the stimulations. The anterior bending angles in both the eyes-open and the eyes-closed conditions were significantly reduced after the GVS. The amount of change in the eyes-closed condition post-GVS was significantly larger than that by sham stimulation. The amount of change in anterior bending angles in the GVS condition was not significantly correlated with Unified Parkinson's Disease Rating Scale motor score, disease duration, the duration of the postural deformities, and the anterior bending angles before the GVS. Binaural monopolar GVS might improve anterior bending posture in PD patients, irrespective of the duration and the severity of disease and postural deformities. Binaural monopolar GVS might be a novel treatment strategy to improve anterior bending posture in PD.

  11. Network-targeted cerebellar transcranial magnetic stimulation improves attentional control

    Science.gov (United States)

    Esterman, Michael; Thai, Michelle; Okabe, Hidefusa; DeGutis, Joseph; Saad, Elyana; Laganiere, Simon E.; Halko, Mark A.

    2018-01-01

    Developing non-invasive brain stimulation interventions to improve attentional control is extremely relevant to a variety of neurologic and psychiatric populations, yet few studies have identified reliable biomarkers that can be readily modified to improve attentional control. One potential biomarker of attention is functional connectivity in the core cortical network supporting attention - the dorsal attention network (DAN). We used a network-targeted cerebellar transcranial magnetic stimulation (TMS) procedure, intended to enhance cortical functional connectivity in the DAN. Specifically, in healthy young adults we administered intermittent theta burst TMS (iTBS) to the midline cerebellar node of the DAN and, as a control, the right cerebellar node of the default mode network (DMN). These cerebellar targets were localized using individual resting-state fMRI scans. Participants completed assessments of both sustained (gradual onset continuous performance task, gradCPT) and transient attentional control (attentional blink) immediately before and after stimulation, in two sessions (cerebellar DAN and DMN). Following cerebellar DAN stimulation, participants had significantly fewer attentional lapses (lower commission error rates) on the gradCPT. In contrast, stimulation to the cerebellar DMN did not affect gradCPT performance. Further, in the DAN condition, individuals with worse baseline gradCPT performance showed the greatest enhancement in gradCPT performance. These results suggest that temporarily increasing functional connectivity in the DAN via network-targeted cerebellar stimulation can enhance sustained attention, particularly in those with poor baseline performance. With regard to transient attention, TMS stimulation improved attentional blink performance across both stimulation sites, suggesting increasing functional connectivity in both networks can enhance this aspect of attention. These findings have important implications for intervention applications

  12. Coupling brain-machine interfaces with cortical stimulation for brain-state dependent stimulation: enhancing motor cortex excitability for neurorehabilitation

    Directory of Open Access Journals (Sweden)

    Alireza eGharabaghi

    2014-03-01

    Full Text Available Motor recovery after stroke is an unsolved challenge despite intensive rehabilitation training programs. Brain stimulation techniques have been explored in addition to traditional rehabilitation training to increase the excitability of the stimulated motor cortex. This modulation of cortical excitability augments the response to afferent input during motor exercises, thereby enhancing skilled motor learning by long-term potentiation-like plasticity. Recent approaches examined brain stimulation applied concurrently with voluntary movements to induce more specific use-dependent neural plasticity during motor training for neurorehabilitation. Unfortunately, such approaches are not applicable for the many severely affected stroke patients lacking residual hand function. These patients require novel activity-dependent stimulation paradigms based on intrinsic brain activity. Here, we report on such brain state-dependent stimulation (BSDS combined with haptic feedback provided by a robotic hand orthosis. Transcranial magnetic stimulation of the motor cortex and haptic feedback to the hand were controlled by sensorimotor desynchronization during motor-imagery and applied within a brain-machine interface environment in one healthy subject and one patient with severe hand paresis in the chronic phase after stroke. BSDS significantly increased the excitability of the stimulated motor cortex in both healthy and post-stroke conditions, an effect not observed in non-BSDS protocols. This feasibility study suggests that closing the loop between intrinsic brain state, cortical stimulation and haptic feedback provides a novel neurorehabilitation strategy for stroke patients lacking residual hand function, a proposal that warrants further investigation in a larger cohort of stroke patients.

  13. Applied electric field enhances DRG neurite growth: influence of stimulation media, surface coating and growth supplements

    Science.gov (United States)

    Wood, Matthew D.; Willits, Rebecca Kuntz

    2009-08-01

    Electrical therapies have been found to aid repair of nerve injuries and have been shown to increase and direct neurite outgrowth during stimulation. This enhanced neural growth existed even after the electric field (EF) or stimulation was removed, but the factors that may influence the enhanced growth, such as stimulation media or surface coating, have not been fully investigated. This study characterized neurite outgrowth and branching under various conditions: EF magnitude and application time, ECM surface coating, medium during EF application and growth supplements. A uniform, low-magnitude EF (24 or 44 V m-1) was applied to dissociated chick embryo dorsal root ganglia seeded on collagen or laminin-coated surfaces. During the growth period, cells were either exposed to NGF or N2, and during stimulation cells were exposed to either unsupplemented media (Ca2+) or PBS (no Ca2+). Parallel controls for each experiment included cells exposed to the chamber with no stimulation and cells remaining outside the chamber. After brief electrical stimulation (10 min), neurite length significantly increased 24 h after application for all conditions studied. Of particular interest, increased stimulation time (10-100 min) further enhanced neurite length on laminin but not on collagen surfaces. Neurite branching was not affected by stimulation on any surface, and no preferential growth of neurites was noted after stimulation. Overall, the results of this report suggest that short-duration electric stimulation is sufficient to enhance neurite length under a variety of conditions. While further data are needed to fully elucidate a mechanism for this increased growth, these data suggest that one focus of those investigations should be the interaction between the growth cone and the substrata.

  14. MR-sialography: optimisation and evaluation of an ultra-fast sequence in parallel acquisition technique and different functional conditions of salivary glands; MR-Sialographie: Optimierung und Bewertung ultraschneller Sequenzen mit paralleler Bildgebung und oraler Stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Habermann, C.R.; Cramer, M.C.; Aldefeld, D.; Weiss, F.; Kaul, M.G.; Adam, G. [Radiologisches Zentrum, Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Universitaetsklinikum Hamburg-Eppendorf (Germany); Graessner, J. [Siemens Medical Systems, Hamburg (Germany); Reitmeier, F.; Jaehne, M. [Kopf- und Hautzentrum, Klinik und Poliklinik fuer Hals-, Nasen- und Ohrenheilkunde, Universitaetsklinikum Hamburg-Eppendorf (Germany); Petersen, K.U. [Zentrum fuer Psychosoziale Medizin, Klinik und Poliklinik fuer Psychiatrie und Psychotherapie, Universitaetsklinikum Hamburg-Eppendorf (Germany)

    2005-04-01

    Purpose: To optimise a fast sequence for MR-sialography and to compare a parallel and non-parallel acquisition technique. Additionally, the effect of oral stimulation regarding the image quality was evaluated. Material and Methods: All examinations were performed by using a 1.5-T superconducting system. After developing a sufficient sequence for MR-sialography, a single-shot turbo-spin-echo sequence (ss-TSE) with an acquisition time of 2.8 sec was used in transverse and oblique sagittal orientation in 27 healthy volunteers. All images were performed with and without parallel imaging technique. The assessment of the ductal system of the submandibular and parotid gland was performed using a 1 to 5 visual scale for each side separately. Images were evaluated by four independent experienced radiologists. For statistical evaluation, an ANOVA with post-hoc comparisons was used with an overall two-tailed significance level of P=.05. For evaluation of interobserver variability, an intraclass correlation was computed and correlation >.08 was determined to indicate a high correlation. Results: All parts of salivary excretal ducts could be visualised in all volunteers, with an overall rating for all ducts of 2.26 (SD{+-}1.09). Between the four observers a high correlation could be obtained with an intraclass correlation of 0.9475. A significant influence regarding the slice angulations could not be obtained (p=0.74). In all healthy volunteers the visibility of excretory ducts improved significantly after oral application of a Sialogogum (p<0.001; {eta}{sup 2}=0.049). The use of a parallel imaging technique did not lead to an improvement of visualisation, showing a significant loss of image quality compared to an acquistion technique without parallel imaging (p<0.001; {eta}{sup 2}=0.013). Conclusion: The optimised ss-TSE MR-sialography seems to be a fast and sufficient technique for visualisation of excretory ducts of the main salivary glands, with no elaborate post

  15. Enhanced motor learning following task-concurrent dual transcranial direct current stimulation.

    Directory of Open Access Journals (Sweden)

    Sophia Karok

    Full Text Available OBJECTIVE: Transcranial direct current stimulation (tDCS of the primary motor cortex (M1 has beneficial effects on motor performance and motor learning in healthy subjects and is emerging as a promising tool for motor neurorehabilitation. Applying tDCS concurrently with a motor task has recently been found to be more effective than applying stimulation before the motor task. This study extends this finding to examine whether such task-concurrent stimulation further enhances motor learning on a dual M1 montage. METHOD: Twenty healthy, right-handed subjects received anodal tDCS to the right M1, dual tDCS (anodal current over right M1 and cathodal over left M1 and sham tDCS in a repeated-measures design. Stimulation was applied for 10 mins at 1.5 mA during an explicit motor learning task. Response times (RT and accuracy were measured at baseline, during, directly after and 15 mins after stimulation. Motor cortical excitability was recorded from both hemispheres before and after stimulation using single-pulse transcranial magnetic stimulation. RESULTS: Task-concurrent stimulation with a dual M1 montage significantly reduced RTs by 23% as early as with the onset of stimulation (p<0.01 with this effect increasing to 30% at the final measurement. Polarity-specific changes in cortical excitability were observed with MEPs significantly reduced by 12% in the left M1 and increased by 69% in the right M1. CONCLUSION: Performance improvement occurred earliest in the dual M1 condition with a stable and lasting effect. Unilateral anodal stimulation resulted only in trendwise improvement when compared to sham. Therefore, task-concurrent dual M1 stimulation is most suited for obtaining the desired neuromodulatory effects of tDCS in explicit motor learning.

  16. Consensus paper: combining transcranial stimulation with neuroimaging

    DEFF Research Database (Denmark)

    Siebner, Hartwig R; Bergmann, Til O; Bestmann, Sven

    2009-01-01

    neuroimaging (online approach), TMS can be used to test how focal cortex stimulation acutely modifies the activity and connectivity in the stimulated neuronal circuits. TMS and neuroimaging can also be separated in time (offline approach). A conditioning session of repetitive TMS (rTMS) may be used to induce...... information obtained by neuroimaging can be used to define the optimal site and time point of stimulation in a subsequent experiment in which TMS is used to probe the functional contribution of the stimulated area to a specific task. In this review, we first address some general methodologic issues that need......In the last decade, combined transcranial magnetic stimulation (TMS)-neuroimaging studies have greatly stimulated research in the field of TMS and neuroimaging. Here, we review how TMS can be combined with various neuroimaging techniques to investigate human brain function. When applied during...

  17. Spinal cord stimulation

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007560.htm Spinal cord stimulation To use the sharing features on this page, please enable JavaScript. Spinal cord stimulation is a treatment for pain that uses ...

  18. Feldspar, Infrared Stimulated Luminescence

    DEFF Research Database (Denmark)

    Jain, Mayank

    2014-01-01

    This entry primarily concerns the characteristics and the origins of infrared-stimulated luminescence in feldspars.......This entry primarily concerns the characteristics and the origins of infrared-stimulated luminescence in feldspars....

  19. Growth hormone stimulation test

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003377.htm Growth hormone stimulation test To use the sharing features on this page, please enable JavaScript. The growth hormone (GH) stimulation test measures the ability of ...

  20. Labor stimulation with oxytocin: effects on obstetrical and neonatal outcomes

    Directory of Open Access Journals (Sweden)

    Pedro Hidalgo-Lopezosa

    Full Text Available Abstract Objective: to evaluate the effects of labor stimulation with oxytocin on maternal and neonatal outcomes. Method: descriptive and analytical study with 338 women who gave birth at a tertiary hospital. Obstetric and neonatal variables were measured and compared in women submitted and non-submitted to stimulation with oxytocin. Statistics were performed using Chi-square test, Fisher exact test, Student t-test; and crude Odds Ratio with 95% confidence interval were calculated. A p < 0.05 was considered statistically significant. Results: stimulation with oxytocin increases the rates of cesarean sections, epidural anesthesia and intrapartum maternal fever in primiparous and multiparous women. It has also been associated with low pH values of umbilical cord blood and with a shorter duration of the first stage of labor in primiparous women. However, it did not affect the rates of 3rd and 4th degree perineal lacerations, episiotomies, advanced neonatal resuscitation, 5-minute Apgar scores and meconium. Conclusion: stimulation with oxytocin should not be used systematically, but only in specific cases. These findings provide further evidence to health professionals and midwives on the use of oxytocin during labor. Under normal conditions, women should be informed of the possible effects of labor stimulation with oxytocin.

  1. Effects of electrical stimulation of the hunger center in the lateral hypothalamus and food reinforcement on impulse activity of the stomach in rabbits under conditions of hunger and satiation.

    Science.gov (United States)

    Zenina, O Yu; Kromin, A A

    2012-10-01

    Stimulation of the lateral hypothalamus in preliminary fed animals in the presence of the food is associated with successful food-procuring behavior, accompanied by regular generation of high-amplitude slow electrical waves by muscles of the lesser curvature, body, and antrum of the stomach, which was reflected in the structure of temporal organization of slow electrical activity in the form of unimodal distribution of slow wave periods typical of satiation state. Despite increased level of food motivation caused by stimulation of the lateral hypothalamus, the additional food intake completely abolished the inhibitory effects of hunger motivation excitement on slow electrical muscle activity in the lesser curvature, body, and antrum of the stomach of satiated rabbits. Changes in slow electrical activity of the stomach muscles in rabbits deprived of food over 24 h and offered food and associated food-procuring behavior during electrical stimulation of the lateral hypothalamus have a two-phase pattern. Despite food intake during phase I of electrical stimulation, the downstream inhibitory effect of hunger motivation excitement on myogenic pacemaker of the lesser curvature of stomach abolishes the stimulating effect of food reinforcement on slow electrical muscle activity in the lesser curvature, body, and antrum of the stomach. During phase II of electrical stimulation, the food reinforcement decreases inhibitory effect of hunger motivation excitement on myogenic pacemaker of the lesser curvature that paces maximal rhythm of slow electrical waves for muscles activity in the lesser curvature, body, and antrum of the stomach, which is reflected by unimodal distribution of slow electrical wave periods. Our results indicated that the structure of temporal organization of slow electrical activity of the stomach muscles reflects convergent interactions of food motivation and reinforcement excitations on the dorsal vagal complex neurons in medulla oblongata.

  2. Dobutamine use for arrhythmia induction during electrical programmed heart stimulation

    International Nuclear Information System (INIS)

    Vanegas, Diego I; Perez, Climaco de J; Montenegro, Juan de J; Orjuela, Alejandro

    2006-01-01

    isoproterenol is the traditionally used drug for incrementing arrhythmia induction when this induction is not achieved during electric programmed heart stimulation under basal conditions. Dobutamine is an adrenergic agent, chemical precursor of isoproterenol, which can be an alternative for inducing arrhythmia during electrical programmed heart stimulation (PES). Patients and methods: a retrospective comparative study of the experience with dobutamine for inducing arrhythmia during electrical programmed heart stimulation was performed. The following data were collected: number of studies, data about the patient (medical record, age, gender, and study indication) protocol of programmed electrical stimulation, basal and under dobutamine or isoproterenol, and result of the study. Isoproterenol was used in doses of 1 to 3 micrograms per minute until the basal heart rate was incremented at least in 25%. Dobutamine was used in doses of 10 to 40 micrograms per kg of body weight, until obtaining the same increment in the basal heart rate. Results: 1054 electrophysiological studies were evaluated. In 144 patients (group A) isoproterenol was used and in 140, dobutamine (group B). In A group the mean age was 39.2 ± 16.2 and 58.3% were females. In-group B, mean age was 41.9 ± 18.6 and 51% were females. The most frequent symptom was palpitation and the most commonly induced arrhythmia was AV nodal reentry tachycardia in both groups. The induction of arrhythmia during the electrical programmed heat stimulation under drugs was similar in-group A (isoproterenol) respect to group B (dobutamine). Conclusions: There were no statistical significant differences in the induction of arrhythmia during electrical programmed heart stimulation using dobutamine or isoproterenol. Dobutamine may be safe and may be successfully used as an alternative to isoproterenol for arrhythmia induction during electrical programmed stimulation

  3. Effects of kinesthetic and cutaneous stimulation during the learning of a viscous force field.

    Science.gov (United States)

    Rosati, Giulio; Oscari, Fabio; Pacchierotti, Claudio; Prattichizzo, Domenico

    2014-01-01

    Haptic stimulation can help humans learn perceptual motor skills, but the precise way in which it influences the learning process has not yet been clarified. This study investigates the role of the kinesthetic and cutaneous components of haptic feedback during the learning of a viscous curl field, taking also into account the influence of visual feedback. We present the results of an experiment in which 17 subjects were asked to make reaching movements while grasping a joystick and wearing a pair of cutaneous devices. Each device was able to provide cutaneous contact forces through a moving platform. The subjects received visual feedback about joystick's position. During the experiment, the system delivered a perturbation through (1) full haptic stimulation, (2) kinesthetic stimulation alone, (3) cutaneous stimulation alone, (4) altered visual feedback, or (5) altered visual feedback plus cutaneous stimulation. Conditions 1, 2, and 3 were also tested with the cancellation of the visual feedback of position error. Results indicate that kinesthetic stimuli played a primary role during motor adaptation to the viscous field, which is a fundamental premise to motor learning and rehabilitation. On the other hand, cutaneous stimulation alone appeared not to bring significant direct or adaptation effects, although it helped in reducing direct effects when used in addition to kinesthetic stimulation. The experimental conditions with visual cancellation of position error showed slower adaptation rates, indicating that visual feedback actively contributes to the formation of internal models. However, modest learning effects were detected when the visual information was used to render the viscous field.

  4. Effects and significance of electrical stimulation Of the vagus nerve on plasma levels of nitric oxide and endothelin in severe acute pancreatitis in rats%电刺激迷走神经对大鼠重症急性胰腺炎血浆内皮素和一氧化氮水平的影响及意义

    Institute of Scientific and Technical Information of China (English)

    金鑫; 冯利; 胡永毅; 陶坤; 赵国海

    2013-01-01

    the left cervical vagus nerve trunk proximal part for 20 min after VNC induction. Groups of rats were sacrificed atlh,3h,6h. Endothelin and nitric oxide leavels were measured in blood of each group rats and histological changes of the pancreas were observed. Results Compared with rats in Sham group, ET and NO levels,the value of ET/NO and pancreatic histopathological score were significantly higher in rats of the SAP group and VNC group ( P < 0. 05 ). In VNC group, NO level was not increased obviously, the value of ET/NO and pancreatic histopathological score upgraded dramatically compared to SAP group (P <0. 05). In VNS group, the value of ET/NO and pancreatic histopathological score were obviously depressed, and NO level was significantly arised compared to SAP group and VNC group (P <0. 05). Conclusion Electrical stimulation of vagus nerves can relief injury degree of severe acute pancreatitis in rats by increaseing NO produce and release and lessening the disequilibrium of N0/ET ratio to improve microcirculation disorder.

  5. Testing Significance Testing

    Directory of Open Access Journals (Sweden)

    Joachim I. Krueger

    2018-04-01

    Full Text Available The practice of Significance Testing (ST remains widespread in psychological science despite continual criticism of its flaws and abuses. Using simulation experiments, we address four concerns about ST and for two of these we compare ST’s performance with prominent alternatives. We find the following: First, the 'p' values delivered by ST predict the posterior probability of the tested hypothesis well under many research conditions. Second, low 'p' values support inductive inferences because they are most likely to occur when the tested hypothesis is false. Third, 'p' values track likelihood ratios without raising the uncertainties of relative inference. Fourth, 'p' values predict the replicability of research findings better than confidence intervals do. Given these results, we conclude that 'p' values may be used judiciously as a heuristic tool for inductive inference. Yet, 'p' values cannot bear the full burden of inference. We encourage researchers to be flexible in their selection and use of statistical methods.

  6. Spinal cord stimulation in patients with painful diabetic neuropathy: a multicentre randomised clinical trial

    DEFF Research Database (Denmark)

    de Vos, Cecile C; Meier, Kaare; Zaalberg, Paul Brocades

    2014-01-01

    Painful diabetic neuropathy (PDN) is a peripheral neuropathic pain condition that is often difficult to relieve. Spinal cord stimulation (SCS) is a proven effective therapy for various types of mixed neuropathic conditions, yet effectiveness of SCS treatment for PDN is not well established. To our......D questionnaires also showed that patients in the SCS group, unlike those in the control group, experienced reduced pain and improved health and quality of life after 6 months of treatment. In patients with refractory painful diabetic neuropathy, spinal cord stimulation therapy significantly reduced...

  7. Transcranial Direct Current Stimulation in Neurodegenerative Disease

    Directory of Open Access Journals (Sweden)

    Argye E. Hillis

    2014-04-01

    Full Text Available We review rationale, challenges, study designs, reported results, and future directions in the use of transcranial direct cranial stimulation (tDCS in neurodegenerative disease, focusing on treatment of spelling in primary progressive aphasia (PPA. Rationale Evidence from both animal studies and human studies indicates that anodal and cathodal tDCS over the brain result in a temporary change in membrane potentials, reducing the threshold for long-term potentiation of neurons in the affected area. This may allow unaffected brain regions to assume functions of diseased regions. Challenges Special challenges in treating individuals with progressive conditions include altered goals of treatment and the possibility that participants may accumulate new deficits over the course of the treatment program that interfere with their ability to understand, retain, or cooperate with aspects of the program. The most serious challenge – particularly for single case designs - is that there may be no stable baseline against which to measure change with treatment. Thus, it is essential to demonstrate that treatment results in a statistically significant change in the slope of decline or improvement. Therefore, demonstration of a significant difference between tDCS and control (sham requires either a large number of participants or a large effect size. Designs The choice of a treatment design reflects these limitations. Group studies with a randomized, double-blind, sham control trial design (without cross-over provide the greatest power to detect a difference between intervention and control conditions, with the fewest participants. A cross-over design, in which all participants (from 1 to many receive both active and sham conditions, in randomized order, requires a larger effect size for the active condition relative to the control condition (or little to no maintenance of treatment gains or carry-over effect to show significant differences between treatment

  8. Modulation of EEG spectral edge frequency during patterned pneumatic oral stimulation in preterm infants

    Science.gov (United States)

    Song, Dongli; Jegatheesan, Priya; Weiss, Sunshine; Govindaswami, Balaji; Wang, Jingyan; Lee, Jaehoon; Oder, Austin; Barlow, Steven M

    2014-01-01

    Background Stimulation of the nervous system plays a central role in brain development and neurodevelopmental outcome. Thalamocortical and corticocortical development is diminished in premature infants and correlated to electroencephalography (EEG) progression. The purpose of this study was to determine the effects of orocutaneous stimulation on the modulation of spectral edge frequency, fc=90% (SEF-90) derived from EEG recordings in preterm infants. Methods Twenty two preterm infants were randomized to experimental and control conditions. Pulsed orocutaneous stimulation was presented during gavage feedings begun at around 32 weeks postmenstrual age (PMA). The SEF-90 was derived from 2-channel EEG recordings. Results Compared to the control condition, the pulsed orocutaneous stimulation produced a significant reorganization of SEF-90 in the left (p = 0.005) and right (p stimulation also produced a significant pattern of short term cortical adaptation and a long term neural adaptation manifest as a 0.5 Hz elevation in SEF-90 after repeated stimulation sessions. Conclusion This is the first study to demonstrate the modulating effects of a servo-controlled oral somatosensory input on the spectral features of EEG activity in preterm infants. PMID:24129553

  9. Subthalamic stimulation: toward a simplification of the electrophysiological procedure.

    Science.gov (United States)

    Fetter, Damien; Derrey, Stephane; Lefaucheur, Romain; Borden, Alaina; Wallon, David; Chastan, Nathalie; Maltete, David

    2016-06-01

    The aim of the present study was to assess the consequences of a simplification of the electrophysiological procedure on the post-operative clinical outcome after subthalamic nucleus implantation in Parkinson disease. Microelectrode recordings were performed on 5 parallel trajectories in group 1 and less than 5 trajectories in group 2. Clinical evaluations were performed 1 month before and 6 months after surgery. After surgery, the UPDRS III score in the off-drug/on-stimulation and on-drug/on-stimulation conditions significantly improved by 66,9% and 82%, respectively in group 1, and by 65.8% and 82.3% in group 2 (P<0.05). Meanwhile, the total number of words (P<0.05) significantly decreased for fluency tasks in both groups. Motor disability improvement and medication reduction were similar in both groups. Our results suggest that the electrophysiological procedure should be simplified as the team's experience increases.

  10. Subthalamic nucleus stimulation does not influence basal glucose metabolism or insulin sensitivity in patients with Parkinson's disease.

    Science.gov (United States)

    Lammers, Nicolette M; Sondermeijer, Brigitte M; Twickler, Th B Marcel; de Bie, Rob M; Ackermans, Mariëtte T; Fliers, Eric; Schuurman, P Richard; La Fleur, Susanne E; Serlie, Mireille J

    2014-01-01

    Animal studies have shown that central dopamine signaling influences glucose metabolism. As a first step to show this association in an experimental setting in humans, we studied whether deep brain stimulation (DBS) of the subthalamic nucleus (STN), which modulates the basal ganglia circuitry, alters basal endogenous glucose production (EGP) or insulin sensitivity in patients with Parkinson's disease (PD). We studied 8 patients with PD treated with DBS STN, in the basal state and during a hyperinsulinemic euglycemic clamp using a stable glucose isotope, in the stimulated and non-stimulated condition. We measured EGP, hepatic insulin sensitivity, peripheral insulin sensitivity (Rd), resting energy expenditure (REE), glucoregulatory hormones, and Parkinson symptoms, using the Unified Parkinson's Disease Rating Scale (UPDRS). Basal plasma glucose and EGP did not differ between the stimulated and non-stimulated condition. Hepatic insulin sensitivity was similar in both conditions and there were no significant differences in Rd and plasma glucoregulatory hormones between DBS on and DBS off. UPDRS was significantly higher in the non-stimulated condition. DBS of the STN in patients with PD does not influence basal EGP or insulin sensitivity. These results suggest that acute modulation of the motor basal ganglia circuitry does not affect glucose metabolism in humans.

  11. Nanoscale Mechanical Stimulation of Human Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    H Nikukar

    2014-05-01

    We observed significant responses after 1 and 2-week stimulations in cell number, cell shapes and phenotypical markers. Microarray was performed for all groups. Cell count showed normal cell growth with stimulation. However, cell surface area, cell perimeter, and arboration after 1-week stimulation showed significant increases. Immunofluorescent studies have showed significant increase in osteocalcin production after stimulation. Conclusions: Nanoscale mechanical vibration showed significant changes in human mesenchymal stem cell behaviours. Cell morphology changed to become more polygonal and increased expression of the osteoblast markers were noted. These findings with gene regulation changes suggesting nanoscale mechanostimulation has stimulated osteoblastogenesis.  Keywords:  Mesenchymal, Nanoscale, Stem Cells.

  12. Electrical stimulation reduces smokers' craving by modulating the coupling between dorsal lateral prefrontal cortex and parahippocampal gyrus.

    Science.gov (United States)

    Yang, Li-Zhuang; Shi, Bin; Li, Hai; Zhang, Wei; Liu, Ying; Wang, Hongzhi; Zhou, Yanfei; Wang, Ying; Lv, Wanwan; Ji, Xuebing; Hudak, Justin; Zhou, Yifeng; Fallgatter, Andreas J; Zhang, Xiaochu

    2017-08-01

    Applying electrical stimulation over the prefrontal cortex can help nicotine dependents reduce cigarette craving. However, the underlying mechanism remains ambiguous. This study investigates this issue with functional magnetic resonance imaging. Thirty-two male chronic smokers received real and sham stimulation over dorsal lateral prefrontal cortex (DLPFC) separated by 1 week. The neuroimaging data of the resting state, the smoking cue-reactivity task and the emotion task after stimulation were collected. The craving across the cue-reactivity task was diminished during real stimulation as compared with sham stimulation. The whole-brain analysis on the cue-reactivity task revealed a significant interaction between the stimulation condition (real vs sham) and the cue type (smoking vs neutral) in the left superior frontal gyrus and the left middle frontal gyrus. The functional connectivity between the left DLPFC and the right parahippocampal gyrus, as revealed by both psychophysical interaction analysis and the resting state functional connectivity, is altered by electrical stimulation. Moreover, the craving change across the real and sham condition is predicted by alteration of functional connectivity revealed by psychophysical interaction analysis. The local and long-distance coupling, altered by the electrical stimulation, might be the underlying neural mechanism of craving regulation. © The Author (2017). Published by Oxford University Press.

  13. Deep-brain-stimulation does not impair deglutition in Parkinson's disease.

    Science.gov (United States)

    Lengerer, Sabrina; Kipping, Judy; Rommel, Natalie; Weiss, Daniel; Breit, Sorin; Gasser, Thomas; Plewnia, Christian; Krüger, Rejko; Wächter, Tobias

    2012-08-01

    A large proportion of patients with Parkinson's disease develop dysphagia during the course of the disease. Dysphagia in Parkinson's disease affects different phases of deglutition, has a strong impact on quality of life and may cause severe complications, i.e., aspirational pneumonia. So far, little is known on how deep-brain-stimulation of the subthalamic nucleus influences deglutition in PD. Videofluoroscopic swallowing studies on 18 patients with Parkinson's disease, which had been performed preoperatively, and postoperatively with deep-brain-stimulation-on and deep-brain-stimulation-off, were analyzed retrospectively. The patients were examined in each condition with three consistencies (viscous, fluid and solid). The 'New Zealand index for multidisciplinary evaluation of swallowing (NZIMES) Subscale One' for qualitative and 'Logemann-MBS-Parameters' for quantitative evaluation were assessed. Preoperatively, none of the patients presented with clinically relevant signs of dysphagia. While postoperatively, the mean daily levodopa equivalent dosage was reduced by 50% and deep-brain-stimulation led to a 50% improvement in motor symptoms measured by the UPDRS III, no clinically relevant influence of deep-brain-stimulation-on swallowing was observed using qualitative parameters (NZIMES). However quantitative parameters (Logemann scale) found significant changes of pharyngeal parameters with deep-brain-stimulation-on as compared to preoperative condition and deep-brain-stimulation-off mostly with fluid consistency. In Parkinson patients without dysphagia deep-brain-stimulation of the subthalamic nucleus modulates the pharyngeal deglutition phase but has no clinically relevant influence on deglutition. Further studies are needed to test if deep-brain-stimulation is a therapeutic option for patients with swallowing disorders. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Direct Electrical Stimulation of the Human Entorhinal Region and Hippocampus Impairs Memory.

    Science.gov (United States)

    Jacobs, Joshua; Miller, Jonathan; Lee, Sang Ah; Coffey, Tom; Watrous, Andrew J; Sperling, Michael R; Sharan, Ashwini; Worrell, Gregory; Berry, Brent; Lega, Bradley; Jobst, Barbara C; Davis, Kathryn; Gross, Robert E; Sheth, Sameer A; Ezzyat, Youssef; Das, Sandhitsu R; Stein, Joel; Gorniak, Richard; Kahana, Michael J; Rizzuto, Daniel S

    2016-12-07

    Deep brain stimulation (DBS) has shown promise for treating a range of brain disorders and neurological conditions. One recent study showed that DBS in the entorhinal region improved the accuracy of human spatial memory. Based on this line of work, we performed a series of experiments to more fully characterize the effects of DBS in the medial temporal lobe on human memory. Neurosurgical patients with implanted electrodes performed spatial and verbal-episodic memory tasks. During the encoding periods of both tasks, subjects received electrical stimulation at 50 Hz. In contrast to earlier work, electrical stimulation impaired memory performance significantly in both spatial and verbal tasks. Stimulation in both the entorhinal region and hippocampus caused decreased memory performance. These findings indicate that the entorhinal region and hippocampus are causally involved in human memory and suggest that refined methods are needed to use DBS in these regions to improve memory. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. tDCS stimulation segregates words in the brain: evidence from aphasia

    Directory of Open Access Journals (Sweden)

    Valentina eFiori

    2013-06-01

    Full Text Available A number of studies have already shown that modulating cortical activity by means of transcranial direct current stimulation (tDCS improves noun or verb naming in aphasic patients. However, it is not yet clear whether these effects are equally obtained through stimulation over the frontal or the temporal regions. In the present study, the same group of aphasic subjects participated in two randomized double-blind experiments involving two intensive language treatments for their noun and verb retrieval difficulties. During each training, each subject was treated with tDCS (20 min., 1mA over the left hemisphere in three different conditions: anodic tDCS over the temporal areas, anodic tDCS over the frontal areas and sham stimulation, while they performed a noun and an action naming tasks. Each experimental condition was run in five consecutive daily sessions over three weeks with 6 days of intersession interval. The order of administration of the two language trainings was randomly assigned to all patients. Overall, with respect to the other two conditions, results showed a significant greater improvement in noun naming after stimulation over the temporal region, while verb naming recovered significantly better after stimulation of the frontal region. These improvements persisted at one month after the end of each treatment suggesting a long-term effect on recovery of the patients’ noun and verb difficulties. These data clearly suggest that the mechanisms of recovery for naming can be segregated coupling tDCS with an intensive language training.

  16. Stimulating the Comfort of Textile Electrodes in Wearable Neuromuscular Electrical Stimulation

    Directory of Open Access Journals (Sweden)

    Hui Zhou

    2015-07-01

    Full Text Available Textile electrodes are becoming an attractive means in the facilitation of surface electrical stimulation. However, the stimulation comfort of textile electrodes and the mechanism behind stimulation discomfort is still unknown. In this study, a textile stimulation electrode was developed using conductive fabrics and then its impedance spectroscopy, stimulation thresholds, and stimulation comfort were quantitatively assessed and compared with those of a wet textile electrode and a hydrogel electrode on healthy subjects. The equivalent circuit models and the finite element models of different types of electrode were built based on the measured impedance data of the electrodes to reveal the possible mechanism of electrical stimulation pain. Our results showed that the wet textile electrode could achieve similar stimulation performance as the hydrogel electrode in motor threshold and stimulation comfort. However, the dry textile electrode was found to have very low pain threshold and induced obvious cutaneous painful sensations during stimulation, in comparison to the wet and hydrogel electrodes. Indeed, the finite element modeling results showed that the activation function along the z direction at the depth of dermis epidermis junction of the dry textile electrode was significantly larger than that of the wet and hydrogel electrodes, thus resulting in stronger activation of pain sensing fibers. Future work will be done to make textile electrodes have similar stimulation performance and comfort as hydrogel electrodes.

  17. Stimulating the Comfort of Textile Electrodes in Wearable Neuromuscular Electrical Stimulation

    Science.gov (United States)

    Zhou, Hui; Lu, Yi; Chen, Wanzhen; Wu, Zhen; Zou, Haiqing; Krundel, Ludovic; Li, Guanglin

    2015-01-01

    Textile electrodes are becoming an attractive means in the facilitation of surface electrical stimulation. However, the stimulation comfort of textile electrodes and the mechanism behind stimulation discomfort is still unknown. In this study, a textile stimulation electrode was developed using conductive fabrics and then its impedance spectroscopy, stimulation thresholds, and stimulation comfort were quantitatively assessed and compared with those of a wet textile electrode and a hydrogel electrode on healthy subjects. The equivalent circuit models and the finite element models of different types of electrode were built based on the measured impedance data of the electrodes to reveal the possible mechanism of electrical stimulation pain. Our results showed that the wet textile electrode could achieve similar stimulation performance as the hydrogel electrode in motor threshold and stimulation comfort. However, the dry textile electrode was found to have very low pain threshold and induced obvious cutaneous painful sensations during stimulation, in comparison to the wet and hydrogel electrodes. Indeed, the finite element modeling results showed that the activation function along the z direction at the depth of dermis epidermis junction of the dry textile electrode was significantly larger than that of the wet and hydrogel electrodes, thus resulting in stronger activation of pain sensing fibers. Future work will be done to make textile electrodes have similar stimulation performance and comfort as hydrogel electrodes. PMID:26193273

  18. Prescription stimulant use is associated with earlier onset of psychosis.

    Science.gov (United States)

    Moran, Lauren V; Masters, Grace A; Pingali, Samira; Cohen, Bruce M; Liebson, Elizabeth; Rajarethinam, R P; Ongur, Dost

    2015-12-01

    A childhood history of attention deficit hyperactivity disorder (ADHD) is common in psychotic disorders, yet prescription stimulants may interact adversely with the physiology of these disorders. Specifically, exposure to stimulants leads to long-term increases in dopamine release. We therefore hypothesized that individuals with psychotic disorders previously exposed to prescription stimulants will have an earlier onset of psychosis. Age of onset of psychosis (AOP) was compared in individuals with and without prior exposure to prescription stimulants while controlling for potential confounding factors. In a sample of 205 patients recruited from an inpatient psychiatric unit, 40% (n = 82) reported use of stimulants prior to the onset of psychosis. Most participants were prescribed stimulants during childhood or adolescence for a diagnosis of ADHD. AOP was significantly earlier in those exposed to stimulants (20.5 vs. 24.6 years stimulants vs. no stimulants, p drugs of abuse, and family history of a first-degree relative with psychosis, the association between stimulant exposure and earlier AOP remained significant. There was a significant gender × stimulant interaction with a greater reduction in AOP for females, whereas the smaller effect of stimulant use on AOP in males did not reach statistical significance. In conclusion, individuals with psychotic disorders exposed to prescription stimulants had an earlier onset of psychosis, and this relationship did not appear to be mediated by IQ or cannabis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Multi-axial mechanical stimulation of tissue engineered cartilage: Review

    Directory of Open Access Journals (Sweden)

    S D Waldman

    2007-04-01

    Full Text Available The development of tissue engineered cartilage is a promising new approach for the repair of damaged or diseased tissue. Since it has proven difficult to generate cartilaginous tissue with properties similar to that of native articular cartilage, several studies have used mechanical stimuli as a means to improve the quantity and quality of the developed tissue. In this study, we have investigated the effect of multi-axial loading applied during in vitro tissue formation to better reflect the physiological forces that chondrocytes are subjected to in vivo. Dynamic combined compression-shear stimulation (5% compression and 5% shear strain amplitudes increased both collagen and proteoglycan synthesis (76 ± 8% and 73 ± 5%, respectively over the static (unstimulated controls. When this multi-axial loading condition was applied to the chondrocyte cultures over a four week period, there were significant improvements in both extracellular matrix (ECM accumulation and the mechanical properties of the in vitro-formed tissue (3-fold increase in compressive modulus and 1.75-fold increase in shear modulus. Stimulated tissues were also significantly thinner than the static controls (19% reduction suggesting that there was a degree of ECM consolidation as a result of long-term multi-axial loading. This study demonstrated that stimulation by multi-axial forces can improve the quality of the in vitro-formed tissue, but additional studies are required to further optimize the conditions to favour improved biochemical and mechanical properties of the developed tissue.

  20. Combined effects of cerebellar transcranial direct current stimulation and transcutaneous spinal direct current stimulation on robot-assisted gait training in patients with chronic brain stroke: A pilot, single blind, randomized controlled trial.

    Science.gov (United States)

    Picelli, Alessandro; Chemello, Elena; Castellazzi, Paola; Filippetti, Mirko; Brugnera, Annalisa; Gandolfi, Marialuisa; Waldner, Andreas; Saltuari, Leopold; Smania, Nicola

    2018-01-01

    Preliminary evidence showed additional effects of anodal transcranial direct current stimulation over the damaged cerebral hemisphere combined with cathodal transcutaneous spinal direct current stimulation during robot-assisted gait training in chronic stroke patients. This is consistent with the neural organization of locomotion involving cortical and spinal control. The cerebellum is crucial for locomotor control, in particular for avoidance of obstacles, and adaptation to novel conditions during walking. Despite its key role in gait control, to date the effects of transcranial direct current stimulation of the cerebellum have not been investigated on brain stroke patients treated with robot-assisted gait training. To evaluate the effects of cerebellar transcranial direct current stimulation combined with transcutaneous spinal direct current stimulation on robot-assisted gait training in patients with chronic brain stroke. After balanced randomization, 20 chronic stroke patients received ten, 20-minute robot-assisted gait training sessions (five days a week, for two consecutive weeks) combined with central nervous system stimulation. Group 1 underwent on-line cathodal transcranial direct current stimulation over the contralesional cerebellar hemisphere + cathodal transcutaneous spinal direct current stimulation. Group 2 received on-line anodal transcranial direct current stimulation over the damaged cerebral hemisphere + cathodal transcutaneous spinal direct current stimulation. The primary outcome was the 6-minute walk test performed before, after, and at follow-up at 2 and 4 weeks post-treatment. The significant differences in the 6-minute walk test noted between groups at the first post-treatment evaluation (p = 0.041) were not maintained at either the 2-week (P = 0.650) or the 4-week (P = 0.545) follow-up evaluations. Our preliminary findings support the hypothesis that cathodal transcranial direct current stimulation over the contralesional

  1. Neural correlates of erotic stimulation under different levels of female sexual hormones.

    Science.gov (United States)

    Abler, Birgit; Kumpfmüller, Daniela; Grön, Georg; Walter, Martin; Stingl, Julia; Seeringer, Angela

    2013-01-01

    Previous studies have demonstrated variable influences of sexual hormonal states on female brain activation and the necessity to control for these in neuroimaging studies. However, systematic investigations of these influences, particularly those of hormonal contraceptives as compared to the physiological menstrual cycle are scarce. In the present study, we investigated the hormonal modulation of neural correlates of erotic processing in a group of females under hormonal contraceptives (C group; N = 12), and a different group of females (nC group; N = 12) not taking contraceptives during their mid-follicular and mid-luteal phases of the cycle. We used functional magnetic resonance imaging to measure hemodynamic responses as an estimate of brain activation during three different experimental conditions of visual erotic stimulation: dynamic videos, static erotic pictures, and expectation of erotic pictures. Plasma estrogen and progesterone levels were assessed in all subjects. No strong hormonally modulating effect was detected upon more direct and explicit stimulation (viewing of videos or pictures) with significant activations in cortical and subcortical brain regions previously linked to erotic stimulation consistent across hormonal levels and stimulation type. Upon less direct and less explicit stimulation (expectation), activation patterns varied between the different hormonal conditions with various, predominantly frontal brain regions showing significant within- or between-group differences. Activation in the precentral gyrus during the follicular phase in the nC group was found elevated compared to the C group and positively correlated with estrogen levels. From the results we conclude that effects of hormonal influences on brain activation during erotic stimulation are weak if stimulation is direct and explicit but that female sexual hormones may modulate more subtle aspects of sexual arousal and behaviour as involved in sexual expectation. Results

  2. Neural correlates of erotic stimulation under different levels of female sexual hormones.

    Directory of Open Access Journals (Sweden)

    Birgit Abler

    Full Text Available Previous studies have demonstrated variable influences of sexual hormonal states on female brain activation and the necessity to control for these in neuroimaging studies. However, systematic investigations of these influences, particularly those of hormonal contraceptives as compared to the physiological menstrual cycle are scarce. In the present study, we investigated the hormonal modulation of neural correlates of erotic processing in a group of females under hormonal contraceptives (C group; N = 12, and a different group of females (nC group; N = 12 not taking contraceptives during their mid-follicular and mid-luteal phases of the cycle. We used functional magnetic resonance imaging to measure hemodynamic responses as an estimate of brain activation during three different experimental conditions of visual erotic stimulation: dynamic videos, static erotic pictures, and expectation of erotic pictures. Plasma estrogen and progesterone levels were assessed in all subjects. No strong hormonally modulating effect was detected upon more direct and explicit stimulation (viewing of videos or pictures with significant activations in cortical and subcortical brain regions previously linked to erotic stimulation consistent across hormonal levels and stimulation type. Upon less direct and less explicit stimulation (expectation, activation patterns varied between the different hormonal conditions with various, predominantly frontal brain regions showing significant within- or between-group differences. Activation in the precentral gyrus during the follicular phase in the nC group was found elevated compared to the C group and positively correlated with estrogen levels. From the results we conclude that effects of hormonal influences on brain activation during erotic stimulation are weak if stimulation is direct and explicit but that female sexual hormones may modulate more subtle aspects of sexual arousal and behaviour as involved in sexual

  3. Stimulation of phagocytosis by sulforaphane

    International Nuclear Information System (INIS)

    Suganuma, Hiroyuki; Fahey, Jed W.; Bryan, Kelley E.; Healy, Zachary R.; Talalay, Paul

    2011-01-01

    Research highlights: → Sulforaphane stimulates the phagocytosis of RAW 264.7 macrophages under conditions of serum deprivation. → This effect does not require Nrf2-dependent induction of phase 2 genes. → Inactivation of macrophage migration inhibitory factor (MIF) by sulforaphane may be involved in stimulation of phagocytosis by sulforaphane. -- Abstract: Sulforaphane, a major isothiocyanate derived from cruciferous vegetables, protects living systems against electrophile toxicity, oxidative stress, inflammation, and radiation. A major protective mechanism is the induction of a network of endogenous cytoprotective (phase 2) genes that are regulated by transcription factor Nrf2. To obtain a more detailed understanding of the anti-inflammatory and immunomodulatory effects of sulforaphane, we evaluated its effect on the phagocytosis activity of RAW 264.7 murine macrophage-like cells by measuring the uptake of 2-μm diameter polystyrene beads. Sulforaphane raised the phagocytosis activity of RAW 264.7 cells but only in the absence or presence of low concentrations (1%) of fetal bovine serum. Higher serum concentrations depressed phagocytosis and abolished its stimulation by sulforaphane. This stimulation did not depend on the induction of Nrf2-regulated genes since it occurred in peritoneal macrophages of nrf2 -/- mice. Moreover, a potent triterpenoid inducer of Nrf2-dependent genes did not stimulate phagocytosis, whereas sulforaphane and another isothiocyanate (benzyl isothiocyanate) had comparable inducer potencies. It has been shown recently that sulforaphane is a potent and direct inactivator of macrophage migration inhibitory factor (MIF), an inflammatory cytokine. Moreover, the addition of recombinant MIF to RAW 264.7 cells attenuated phagocytosis, but sulforaphane-inactivated MIF did not affect phagocytosis. The inactivation of MIF may therefore be involved in the phagocytosis-enhancing activity of sulforaphane.

  4. Stimulation of phagocytosis by sulforaphane

    Energy Technology Data Exchange (ETDEWEB)

    Suganuma, Hiroyuki, E-mail: hsuganu1@jhmi.edu [Lewis B. and Dorothy Cullman Cancer Chemoprotection Center, Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205 (United States); Fahey, Jed W., E-mail: jfahey@jhmi.edu [Lewis B. and Dorothy Cullman Cancer Chemoprotection Center, Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205 (United States); Bryan, Kelley E., E-mail: kbryanm1@jhmi.edu [Lewis B. and Dorothy Cullman Cancer Chemoprotection Center, Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205 (United States); Healy, Zachary R., E-mail: zhealy1@jhmi.edu [Lewis B. and Dorothy Cullman Cancer Chemoprotection Center, Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205 (United States); Talalay, Paul, E-mail: ptalalay@jhmi.edu [Lewis B. and Dorothy Cullman Cancer Chemoprotection Center, Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205 (United States)

    2011-02-04

    Research highlights: {yields} Sulforaphane stimulates the phagocytosis of RAW 264.7 macrophages under conditions of serum deprivation. {yields} This effect does not require Nrf2-dependent induction of phase 2 genes. {yields} Inactivation of macrophage migration inhibitory factor (MIF) by sulforaphane may be involved in stimulation of phagocytosis by sulforaphane. -- Abstract: Sulforaphane, a major isothiocyanate derived from cruciferous vegetables, protects living systems against electrophile toxicity, oxidative stress, inflammation, and radiation. A major protective mechanism is the induction of a network of endogenous cytoprotective (phase 2) genes that are regulated by transcription factor Nrf2. To obtain a more detailed understanding of the anti-inflammatory and immunomodulatory effects of sulforaphane, we evaluated its effect on the phagocytosis activity of RAW 264.7 murine macrophage-like cells by measuring the uptake of 2-{mu}m diameter polystyrene beads. Sulforaphane raised the phagocytosis activity of RAW 264.7 cells but only in the absence or presence of low concentrations (1%) of fetal bovine serum. Higher serum concentrations depressed phagocytosis and abolished its stimulation by sulforaphane. This stimulation did not depend on the induction of Nrf2-regulated genes since it occurred in peritoneal macrophages of nrf2{sup -/-} mice. Moreover, a potent triterpenoid inducer of Nrf2-dependent genes did not stimulate phagocytosis, whereas sulforaphane and another isothiocyanate (benzyl isothiocyanate) had comparable inducer potencies. It has been shown recently that sulforaphane is a potent and direct inactivator of macrophage migration inhibitory factor (MIF), an inflammatory cytokine. Moreover, the addition of recombinant MIF to RAW 264.7 cells attenuated phagocytosis, but sulforaphane-inactivated MIF did not affect phagocytosis. The inactivation of MIF may therefore be involved in the phagocytosis-enhancing activity of sulforaphane.

  5. Optimal number of stimulation contacts for coordinated reset neuromodulation

    Science.gov (United States)

    Lysyansky, Borys; Popovych, Oleksandr V.; Tass, Peter A.

    2013-01-01

    In this computational study we investigate coordinated reset (CR) neuromodulation designed for an effective control of synchronization by multi-site stimulation of neuronal target populations. This method was suggested to effectively counteract pathological neuronal synchrony characteristic for several neurological disorders. We study how many stimulation sites are required for optimal CR-induced desynchronization. We found that a moderate increase of the number of stimulation sites may significantly prolong the post-stimulation desynchronized transient after the stimulation is completely switched off. This can, in turn, reduce the amount of the administered stimulation current for the intermittent ON–OFF CR stimulation protocol, where time intervals with stimulation ON are recurrently followed by time intervals with stimulation OFF. In addition, we found that the optimal number of stimulation sites essentially depends on how strongly the administered current decays within the neuronal tissue with increasing distance from the stimulation site. In particular, for a broad spatial stimulation profile, i.e., for a weak spatial decay rate of the stimulation current, CR stimulation can optimally be delivered via a small number of stimulation sites. Our findings may contribute to an optimization of therapeutic applications of CR neuromodulation. PMID:23885239

  6. When does mechanical plantar stimulation promote sensory re-weighing: standing on a firm or compliant surface?

    Science.gov (United States)

    Preszner-Domjan, Andrea; Nagy, Edit; Szíver, Edit; Feher-Kiss, Anna; Horvath, Gyöngyi; Kranicz, Janos

    2012-08-01

    The purpose of this study was to investigate the effect of different types of mechanical stimulation of the sole on standing postural stability in healthy, young adults. Fifty subjects (34 women, 16 men; mean age 23 ± 2 (mean ± SE)) stood barefoot on fixed force plates both with open and closed eyes on firm surface and then on compliant surface (foam). A modified clinical test of sensory interaction on balance protocol was employed to assess the center of gravity (COG) excursions along anteroposterior (AP) and mediolateral (ML) axes on each surface and visual condition. After the baseline measurement, a stimulation was applied with an elastic spiked layer topped to the firm and then foam surface, and the COG excursions were measured during the stimulation, and then at least 30 min after the stimulation of the spiked layer, we used 10 min of manual static and glide pressure applied to the plantar surface of both feet. Immediately after manual stimulation, static balance parameters were measured again. Results showed that after manual stimulation, the sway path with closed eyes decreased significantly on the AP and ML directions on firm surface conditions. The spiked layer caused significantly decreased sway path on firm platform in both directions, but it was ineffective on compliant surface. Our results established that the activation of plantar mechanoreceptors by 10-min manual stimulation can partially compensate subjects for the absence of visual input and the lack of accurate pressure information from the supporting surface, too.

  7. Immediate effect of laryngeal surface electrical stimulation on swallowing performance.

    Science.gov (United States)

    Takahashi, Keizo; Hori, Kazuhiro; Hayashi, Hirokazu; Fujiu-Kurachi, Masako; Ono, Takahiro; Tsujimura, Takanori; Magara, Jin; Inoue, Makoto

    2018-01-01

    Surface electrical stimulation of the laryngeal region is used to improve swallowing in dysphagic patients. However, little is known about how electrical stimulation affects tongue movements and related functions. We investigated the effect of electrical stimulation on tongue pressure and hyoid movement, as well as suprahyoid and infrahyoid muscle activity, in 18 healthy young participants. Electrical stimulation (0.2-ms duration, 80 Hz, 80% of each participant's maximal tolerance) of the laryngeal region was applied. Each subject swallowed 5 ml of barium sulfate liquid 36 times at 10-s intervals. During the middle 2 min, electrical stimulation was delivered. Tongue pressure, electromyographic activity of the suprahyoid and infrahyoid muscles, and videofluorographic images were simultaneously recorded. Tongue pressure during stimulation was significantly lower than before or after stimulation and was significantly greater after stimulation than at baseline. Suprahyoid activity after stimulation was larger than at baseline, while infrahyoid muscle activity did not change. During stimulation, the position of the hyoid at rest was descended, the highest hyoid position was significantly inferior, and the vertical movement was greater than before or after stimulation. After stimulation, the positions of the hyoid at rest and at the maximum elevation were more superior than before stimulation. The deviation of the highest positions of the hyoid before and after stimulation corresponded to the differences in tongue pressures at those times. These results suggest that surface electrical stimulation applied to the laryngeal region during swallowing may facilitate subsequent hyoid movement and tongue pressure generation after stimulation. NEW & NOTEWORTHY Surface electrical stimulation applied to the laryngeal region during swallowing may facilitate subsequent hyoid movement and tongue pressure generation after stimulation. Tongue muscles may contribute to overshot recovery

  8. Stimulants for the Control of Hedonic Appetite

    OpenAIRE

    Poulton, Alison S.; Hibbert, Emily J.; Champion, Bernard L.; Nanan, Ralph K. H.

    2016-01-01

    The focus of this paper is treatment of obesity in relation to the management of hedonic appetite. Obesity is a complex condition which may be potentiated by excessive reward seeking in combination with executive functioning deficits that impair cognitive control of behaviour. Stimulant medications address both reward deficiency and enhance motivation, as well as suppressing appetite. They have long been recognised to be effective for treating obesity. However, stimulants can be abused for th...

  9. [Transcranial magnetic stimulation].

    Science.gov (United States)

    Tormos, J M; Catalá, M D; Pascual-Leone, A

    Transcranial magnetic stimulation (TMS) permits stimulation of the cerebral cortex in humans without requiring open access to the brain and is one of the newest tools available in neuroscience. There are two main types of application: single-pulse TMS and repetitive TMS. The magnetic stimulator is composed of a series of capacitors that store the voltage necessary to generate a stimulus of the sufficient intensity of generate an electric field in the stimulation coil. The safety of TMS is supported by the considerable experience derived from studies involving electrical stimulation of the cortex in animals and humans, and also specific studies on the safety of TMS in humans. In this article we review historical and technical aspects of TMS, describe its adverse effects and how to avoid them, summarize the applications of TMS in the investigation of different cerebral functions, and discuss the possibility of using TMS for the treatment of neuropsychiatric disorders.

  10. Neuropsychology of selective attention and magnetic cortical stimulation.

    Science.gov (United States)

    Sabatino, M; Di Nuovo, S; Sardo, P; Abbate, C S; La Grutta, V

    1996-01-01

    Informed volunteers were asked to perform different neuropsychological tests involving selective attention under control conditions and during transcranial magnetic cortical stimulation. The tests chosen involved the recognition of a specific letter among different letters (verbal test) and the search for three different spatial orientations of an appendage to a square (visuo-spatial test). For each test the total time taken and the error rate were calculated. Results showed that cortical stimulation did not cause a worsening in performance. Moreover, magnetic stimulation of the temporal lobe neither modified completion time in both verbal and visuo-spatial tests nor changed error rate. In contrast, magnetic stimulation of the pre-frontal area induced a significant reduction in the performance time of both the verbal and visuo-spatial tests always without an increase in the number of errors. The experimental findings underline the importance of the pre-frontal area in performing tasks requiring a high level of controlled attention and suggest the need to adopt an interdisciplinary approach towards the study of neurone/mind interface mechanisms.

  11. Studies on the radiation chemistry of biomolecules in aqueous solution with specific objective of minimizing their radiolytic degradation. Coordinated programme for Asia and the Pacific Region on radiation sterilization practices significant to local medical supplies and conditions

    International Nuclear Information System (INIS)

    Narayana Rao, K.

    1979-01-01

    As part of a study of radiolytic degradation of pharmaceuticals during radiosterilization, the basic radiation chemistry of the B-group vitamins, nicotinamide, pyridoxin, riboflavin and thiamine, and the reaction of hydrogen peroxide with these same materials has been investigated. The various aspects studied were - radiolysis under controlled conditions, effects of phase, temperature, pH and nature and concentration of additives. Some of the conclusions are: 1) with oxygen saturated aqueous solutions containing glucose, the radiolytic degradation of the vitamins is reduced: 2) results a similar for N 2 O saturated aqueous solutions; 3) in glucose-containing solutions, the protective effect is considerably modified at higher temperatures; and 4) irradiation of air-saturated aqueous solutions in the frozen state leads to reduced decomposition. It is concluded that in the presence of oxygen, in frozen matrices at low temperature, it appears possible to reduce the radiolytic breakdown of vitamins to low levels

  12. Addictive drugs and brain stimulation reward.

    Science.gov (United States)

    Wise, R A

    1996-01-01

    Direct electrical or chemical stimulation of specific brain regions can establish response habits similar to those established by natural rewards such as food or sexual contact. Cocaine, mu and delta opiates, nicotine, phencyclidine, and cannabis each have actions that summate with rewarding electrical stimulation of the medial forebrain bundle (MFB). The reward-potentiating effects of amphetamine and opiates are associated with central sites of action where these drugs also have their direct rewarding effects, suggesting common mechanisms for drug reward per se and for drug potentiation of brain stimulation reward. The central sites at which these and perhaps other drugs of abuse potentiate brain stimulation reward and are rewarding in their own right are consistent with the hypothesis that the laboratory reward of brain stimulation and the pharmacological rewards of addictive drugs are habit forming because they act in the brain circuits that subserve more natural and biologically significant rewards.

  13. [Electrical acupoint stimulation increases athletes' rapid strength].

    Science.gov (United States)

    Yang, Hua-yuan; Liu, Tang-yi; Kuai, Le; Gao, Ming

    2006-05-01

    To search for a stimulation method for increasing athletes' performance. One hundred and fifty athletes were randomly divided into a trial group and a control group, 75 athletes in each group. Acupoints were stimulated with audio frequency pulse modulated wave and multi-blind method were used to investigate effects of the electric stimulation of acupoints on 30-meter running, standing long jumping and Cybex isokinetic testing index. The acupoint electric stimulation method could significantly increase athlete's performance (P < 0.05), and the biomechanical indexes, maximal peak moment of force (P < 0.05), force moment accelerating energy (P < 0.05) and average power (P < 0.05). Electrical acupoint stimulation can enhance athlete's rapid strength.

  14. Thermo-stimulated current and dielectric loss in composite materials

    International Nuclear Information System (INIS)

    Nishijima, S.; Hagihara, T.; Okada, T.

    1986-01-01

    Thermo-stimulated current and dielectric loss measurements have been performed on five kinds of commercially available composite materials in order to study the electric properties of composite materials at low temperatures. Thermo-stimulated current measurements have been made on the composite materials in which the matrix quality was changed intentionally. The changes in the matrices were introduced by gamma irradiation or different curing conditions. Thermo-stimulated current and dielectric loss measurements revealed the number and the molecular weight of dipolar molecules. The different features of thermo-stimulated current and dielectric losses were determined for different composite materials. The gamma irradiation and the curing conditions especially affect the thermo-stimulated current features. The changes in macroscopic mechanical properties reflect those of thermo-stimulated current. It was found that the change in quality and/or degradation of the composite materials could be detected by means of thermo-stimulated current and/or dielectric loss measurements

  15. Disturbance of visual search by stimulating to posterior parietal cortex in the brain using transcranial magnetic stimulation

    Science.gov (United States)

    Iramina, Keiji; Ge, Sheng; Hyodo, Akira; Hayami, Takehito; Ueno, Shoogo

    2009-04-01

    In this study, we applied a transcranial magnetic stimulation (TMS) to investigate the temporal aspect for the functional processing of visual attention. Although it has been known that right posterior parietal cortex (PPC) in the brain has a role in certain visual search tasks, there is little knowledge about the temporal aspect of this area. Three visual search tasks that have different difficulties of task execution individually were carried out. These three visual search tasks are the "easy feature task," the "hard feature task," and the "conjunction task." To investigate the temporal aspect of the PPC involved in the visual search, we applied various stimulus onset asynchronies (SOAs) and measured the reaction time of the visual search. The magnetic stimulation was applied on the right PPC or the left PPC by the figure-eight coil. The results show that the reaction times of the hard feature task are longer than those of the easy feature task. When SOA=150 ms, compared with no-TMS condition, there was a significant increase in target-present reaction time when TMS pulses were applied. We considered that the right PPC was involved in the visual search at about SOA=150 ms after visual stimulus presentation. The magnetic stimulation to the right PPC disturbed the processing of the visual search. However, the magnetic stimulation to the left PPC gives no effect on the processing of the visual search.

  16. Effect of electrical stimulation on consumer acceptance of mutton ...

    African Journals Online (AJOL)

    MarianaD

    -voltage electrical stimulation, HVES – high-voltage electrical stimulation, ... Electrical stimulation varied between 21 V – 1100 V. The drop in pH was significantly faster in the .... Table 2 Gender and age distribution of consumer panel (n=229).

  17. Computational analysis of transcranial magnetic stimulation in the presence of deep brain stimulation probes

    Science.gov (United States)

    Syeda, F.; Holloway, K.; El-Gendy, A. A.; Hadimani, R. L.

    2017-05-01

    Transcranial Magnetic Stimulation is an emerging non-invasive treatment for depression, Parkinson's disease, and a variety of other neurological disorders. Many Parkinson's patients receive the treatment known as Deep Brain Stimulation, but often require additional therapy for speech and swallowing impairment. Transcranial Magnetic Stimulation has been explored as a possible treatment by stimulating the mouth motor area of the brain. We have calculated induced electric field, magnetic field, and temperature distributions in the brain using finite element analysis and anatomically realistic heterogeneous head models fitted with Deep Brain Stimulation leads. A Figure of 8 coil, current of 5000 A, and frequency of 2.5 kHz are used as simulation parameters. Results suggest that Deep Brain Stimulation leads cause surrounding tissues to experience slightly increased E-field (Δ Emax =30 V/m), but not exceeding the nominal values induced in brain tissue by Transcranial Magnetic Stimulation without leads (215 V/m). The maximum temperature in the brain tissues surrounding leads did not change significantly from the normal human body temperature of 37 °C. Therefore, we ascertain that Transcranial Magnetic Stimulation in the mouth motor area may stimulate brain tissue surrounding Deep Brain Stimulation leads, but will not cause tissue damage.

  18. Three lifestyle-related issues of major significance for public health among the Inuit in contemporary Greenland: a review of adverse childhood conditions, obesity, and smoking in a period of social transition.

    Science.gov (United States)

    Bjerregaard, Peter; Larsen, Christina V L

    2018-01-01

    Greenland is a country in transition from a colonial past with subsistence hunting and fishing to an urban Nordic welfare state. Epidemiological transition from infectious to chronic diseases has been evident since the 1950s. Ninety percent of the population is Inuit. We studied three public health issues based on published literature, namely adverse childhood experiences, addictive behavior, and suicide; diet and obesity; and smoking. Alcohol consumption was high in the 1970s and 1980s with accompanying family and social disruption. This is still a cause of poor mental health and suicides in the generations most affected. The diet is changing from a traditional diet of fish and marine mammals to imported food including food items rich in sugar and fat from domestic animals, and the level of physical activity is decreasing with an ensuing epidemic rise in obesity. The prevalence of smoking is high at around 60% among both men and women and is only slowly decreasing. Smoking shows large social variation, and tobacco-related diseases are widespread. The diseases and conditions outlined above all contribute towards a low life expectancy at birth-69 years for men and 74 years for women in 2011-2015-compared with 78 and 84 years for men and women, respectively, on average in the European countries. The translation of government public health programs into local activities needs strengthening, and it must be realized that the improvement of public health is a long-term process.

  19. Paired pulse TMS stimulation and human tongue corticomotor pathways

    DEFF Research Database (Denmark)

    Kothari, Mohit; Svensson, Peter; Nielsen, Jørgen Feldbæk

    Objectives: Paired pulse transcranial magnetic stimulation (ppTMS) can be used to assess short-term interval intra-cortical inhibitory (SICI) and facilitatory (ICF) networks. The degree of SICI and ICF varies with interstimulus intervals (ISI) and stimulus intensities of the conditioning stimulus...... ms were applied 8 times each in randomized order in two blocks (CS intensity of 70% and 80% of rMT, respectively). The amplitudes of the averaged MEPs were analyzed with analysis of variance. Results: There was an overall effect of ISI (P... intensities (P = 0.984). Post-hoc tests revealed that there was significant SICI with ppTMS ISI of 2, 2.5, 3, and 3.5 ms compared with single pulse stimulation (Pstimulation (P=0.988). There was no interaction between...

  20. ENSAYOS DE BIOESTIMULACIÓN ALGAL CON DIFERENTES RELACIONES NITRÓGENO: FÓSFORO, BAJO CONDICIONES DE LABORATORIO ASSAYS OF ALGAL BIO-STIMULATION WITH DIFFERENT NITROGEN-PHOSPHORUS RELATIONS UNDER LABORATORY CONDITIONS

    Directory of Open Access Journals (Sweden)

    Néstor J. Aguirre Ramírez

    2007-07-01

    Full Text Available Esta investigación tuvo como objetivo evaluar el crecimiento del alga Chlorella vulgaris ante diferentes concentraciones de nitrógeno y fósforo, a través de ensayos de bioestimulación en una cámara ambiental. Las variables respuesta fueron la densidad algal y la turbidez, evaluadas por conteo en una cámara de Neubauer y por espectrofotometría, empleando un equipo NOVA 60. Para los ensayos de bioestimulación se utilizó el medio de cultivo Estándar Métodos, sugerido por APHA, AWWA (1995 con diferentes concentraciones de nitrógeno y de fósforo. En general, se concluyó que la bioestimulación del crecimiento de Chlorella vulgaris depende de la relación estequiométrica entre el nitrógeno y el fósforo. En síntesis, cuando el fósforo se hace menos limitante se presentó una mayor tasa de crecimiento poblacional. Sin embargo, el nitrógeno es también esencial y ambos nutrientes no pueden ser analizados independientemente. Por lo tanto, el aumento o la disminución de las concentraciones de estos nutrientes en los ambientes acuáticos deben ser estudiados conjuntamente a través de sus relaciones estequiométricas.The main objective of this work was to evaluate the growth of algal population Chlorella vulgaris in different concentrations from nitrogen and phosphorus, through tests of algal stimulation in an environmental camera. The answer variables were algal density and turbidity, evaluated by count in a camera of Neubauer and with a photometric method (# 077, using NOVA 60 equipment. For the algal stimulation tests, methods suggested by APHA, AWWA (1995 with different phosphorus and nitrogen concentrations were used In general we concluded that the algal stimulation of the population growth of C. vulgaris depends on the stoichiometric relation between nitrogen and phosphorus. In synthesis when phosphorus becomes a less limit, a greater rate of population growth, appears; nevertheless nitrogen is also essential and both nutrients

  1. Criminality Among Rural Stimulant Users in the United States

    OpenAIRE

    Oser, Carrie; Leukefeld, Carl; Staton-Tindall, Michele; Duvall, Jamieson; Garrity, Thomas; Stoops, William; Falck, Russel; Wang, Jichuan; Carlson, Robert; Sexton, Rocky; Wright, Patricia; Booth, Brenda

    2011-01-01

    Despite the increase in media attention on “meth cooking” in rural areas of the United States, little is known about rural stimulant use, particularly the criminality associated with stimulant use. Data were collected from community stimulant users in rural Ohio, Arkansas, and Kentucky (N=709). Findings from three logistic regression models indicate that younger stimulant users (x =32.55, SD = 10.35), those with more convictions, and those who used crack frequently were significantly more lik...

  2. Five-year follow-up of 23 asymmetrical Parkinson's disease patients treated with unilateral subthalamic nucleus stimulation

    Institute of Scientific and Technical Information of China (English)

    Jinchuan Liang; Xiaowu Hu; Xiaoping Zhou; Xiufeng Jiang; Yiqun Cao; Laixing Wang; Aiguo Jin; Jianmin Liu

    2012-01-01

    In this study, 23 asymmetrical Parkinson's disease patients were treated with unilateral deep brain stimulation of the subthalamic nucleus and followed up for 5 years. At 5 years after stimulation treatment, Unified Parkinson's Disease Rating Scale II, III and axial symptom scores in the off-drug condition were significantly increased compared those at baseline. However, total Unified Parkinson's Disease Rating Scale II, III and axial symptom scores were significantly lower with stimulation-on compared with the synchronous stimulation-off state in off-drug condition, and the motor symptoms of contralateral side limbs were effectively controlled. Only low Hoehn-Yahr stage was correlated with good long-term postoperative improvement in motor symptoms. The mean levodopa-equivalent daily dose after stimulation treatment was significantly lower than that before treatment, but dyskinesias became worse. Our experimental findings indicate that unilateral deep brain stimulation of the subthalamic nucleus is an effective treatment for improving motor symptoms in well selected asymmetrical Parkinson's disease patients presenting no severe axial symptoms and dyskinesias.

  3. Enhanced hepatic insulin signaling in the livers of high altitude native rats under basal conditions and in the livers of low altitude native rats under insulin stimulation: a mechanistic study.

    Science.gov (United States)

    Al Dera, Hussain; Eleawa, Samy M; Al-Hashem, Fahaid H; Mahzari, Moeber M; Hoja, Ibrahim; Al Khateeb, Mahmoud

    2017-07-01

    This study was designed to investigate the role of the liver in lowering fasting blood glucose levels (FBG) in rats native to high (HA) and low altitude (LA) areas. As compared with LA natives, besides the improved insulin and glucose tolerance, HA native rats had lower FBG, at least mediated by inhibition of hepatic gluconeogenesis and activation of glycogen synthesis. An effect that is mediated by the enhancement of hepatic insulin signaling mediated by the decreased phosphorylation of TSC induced inhibition of mTOR function. Such effect was independent of activation of AMPK nor stabilization of HIF1α, but most probably due to oxidative stress induced REDD1 expression. However, under insulin stimulation, and in spite of the less activated mTOR function in HA native rats, LA native rats had higher glycogen content and reduced levels of gluconeogenic enzymes with a more enhanced insulin signaling, mainly due to higher levels of p-IRS1 (tyr612).

  4. Thermally stimulated scattering in plasmas

    DEFF Research Database (Denmark)

    Dysthe, K. B.; Mjølhus, E.; Pécseli, H. L.

    1985-01-01

    this experiment local heat conduction is of little importance and the dynamic evolution for the electron temperature is dominated by heating and energy exchange with the ion component. These features are incorporated in the analysis. The resulting set of equations gives a growth rate and characteristic scale size......A theory for stimulated scattering of a laser beam is formulated where the dominant nonlinearity is the ohmic heating of the plasma. The analysis is carried out with particular reference to experimental investigations of CO2 laser heating of linear discharge plasma. In the conditions characterizing...

  5. Patterned sensory nerve stimulation enhances the reactivity of spinal Ia inhibitory interneurons.

    Science.gov (United States)

    Kubota, Shinji; Hirano, Masato; Morishita, Takuya; Uehara, Kazumasa; Funase, Kozo

    2015-03-25

    Patterned sensory nerve stimulation has been shown to induce plastic changes in the reciprocal Ia inhibitory circuit. However, the mechanisms underlying these changes have not yet been elucidated in detail. The aim of the present study was to determine whether the reactivity of Ia inhibitory interneurons could be altered by patterned sensory nerve stimulation. The degree of reciprocal Ia inhibition, the conditioning effects of transcranial magnetic stimulation (TMS) on the soleus (SOL) muscle H-reflex, and the ratio of the maximum H-reflex amplitude versus maximum M-wave (H(max)/M(max)) were examined in 10 healthy individuals. Patterned electrical nerve stimulation was applied to the common peroneal nerve every 1 s (100 Hz-5 train) at the motor threshold intensity of tibialis anterior muscle to induce activity changes in the reciprocal Ia inhibitory circuit. Reciprocal Ia inhibition, the TMS-conditioned H-reflex amplitude, and H(max)/M(max) were recorded before, immediately after, and 15 min after the electrical stimulation. The patterned electrical nerve stimulation significantly increased the degree of reciprocal Ia inhibition and decreased the amplitude of the TMS-conditioned H-reflex in the short-latency inhibition phase, which was presumably mediated by Ia inhibitory interneurons. However, it had no effect on H(max)/M(max). Our results indicated that patterned sensory nerve stimulation could modulate the activity of Ia inhibitory interneurons, and this change may have been caused by the synaptic modification of Ia inhibitory interneuron terminals. These results may lead to a clearer understanding of the spinal cord synaptic plasticity produced by repetitive sensory inputs. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

  6. Impact of Prefrontal Theta Burst Stimulation on Clinical Neuropsychological Tasks

    Directory of Open Access Journals (Sweden)

    Raquel Viejo-Sobera

    2017-08-01

    Full Text Available Theta burst stimulation (TBS protocols hold high promise in neuropsychological rehabilitation. Nevertheless, their ability to either decrease (continuous, cTBS or increase (intermittent, iTBS cortical excitability in areas other than the primary motor cortex, and their consistency modulating human behaviors with clinically relevant tasks remain to be fully established. The behavioral effects of TBS over the dorsolateral prefrontal cortex (dlPFC are particularly interesting given its involvement in working memory (WM and executive functions (EF, often impaired following frontal brain damage. We aimed to explore the ability of cTBS and iTBS to modulate WM and EF in healthy individuals, assessed with clinical neuropsychological tests (Digits Backward, 3-back task, Stroop Test, and Tower of Hanoi. To this end, 36 participants were assessed using the four tests 1 week prior to stimulation and immediately following a single session of either cTBS, iTBS, or sham TBS, delivered to the left dlPFC. No significant differences were found across stimulation conditions in any of the clinical tasks. Nonetheless, in some of them, active stimulation induced significant pre/post performance modulations, which were not found for the sham condition. More specifically, sham stimulation yielded improvements in the 3-back task and the Color, Color-Word, and Interference Score of the Stroop Test, an effect likely caused by task practice. Both, iTBS and cTBS, produced improvements in Digits Backward and impairments in 3-back task accuracy. Moreover, iTBS increased Interference Score in the Stroop Test in spite of the improved word reading and impaired color naming, whereas cTBS decreased the time required to complete the Tower of Hanoi. Differing from TBS outcomes reported for cortico-spinal measures on the primary motor cortex, our analyses did not reveal any of the expected performance differences across stimulation protocols. However, if one considers independently

  7. [Is it possible to train Achatina fulica using visual stimulation?].

    Science.gov (United States)

    Baĭkova, I B; Zhukov, V V

    2001-01-01

    The conditioned behavior to visual stimuli was obtained in Achatina fulica mollusk on the basis of its negative phototaxis. Directional moving of snails toward black cards was accompanied by the negative unconditioned stimulation (electric current). Learning was expressed in a statistically significant decrease in locomotor activity of animals and decrease in the rate of preference of sections with black cards. Learning developed within two daily training sessions with 30 trials in each of them. Learning traces were observed as defensive behavior at least during a month after reinforcement elimination.

  8. Detecting Novelty and Significance

    Science.gov (United States)

    Ferrari, Vera; Bradley, Margaret M.; Codispoti, Maurizio; Lang, Peter J.

    2013-01-01

    Studies of cognition often use an “oddball” paradigm to study effects of stimulus novelty and significance on information processing. However, an oddball tends to be perceptually more novel than the standard, repeated stimulus as well as more relevant to the ongoing task, making it difficult to disentangle effects due to perceptual novelty and stimulus significance. In the current study, effects of perceptual novelty and significance on ERPs were assessed in a passive viewing context by presenting repeated and novel pictures (natural scenes) that either signaled significant information regarding the current context or not. A fronto-central N2 component was primarily affected by perceptual novelty, whereas a centro-parietal P3 component was modulated by both stimulus significance and novelty. The data support an interpretation that the N2 reflects perceptual fluency and is attenuated when a current stimulus matches an active memory representation and that the amplitude of the P3 reflects stimulus meaning and significance. PMID:19400680

  9. Significant NRC Enforcement Actions

    Data.gov (United States)

    Nuclear Regulatory Commission — This dataset provides a list of Nuclear Regulartory Commission (NRC) issued significant enforcement actions. These actions, referred to as "escalated", are issued by...

  10. Intracranial self-stimulation to evaluate abuse potential of drugs.

    Science.gov (United States)

    Negus, S Stevens; Miller, Laurence L

    2014-07-01

    Intracranial self-stimulation (ICSS) is a behavioral procedure in which operant responding is maintained by pulses of electrical brain stimulation. In research to study abuse-related drug effects, ICSS relies on electrode placements that target the medial forebrain bundle at the level of the lateral hypothalamus, and experimental sessions manipulate frequency or amplitude of stimulation to engender a wide range of baseline response rates or response probabilities. Under these conditions, drug-induced increases in low rates/probabilities of responding maintained by low frequencies/amplitudes of stimulation are interpreted as an abuse-related effect. Conversely, drug-induced decreases in high rates/probabilities of responding maintained by high frequencies/amplitudes of stimulation can be interpreted as an abuse-limiting effect. Overall abuse potential can be inferred from the relative expression of abuse-related and abuse-limiting effects. The sensitivity and selectivity of ICSS to detect abuse potential of many classes of abused drugs is similar to the sensitivity and selectivity of drug self-administration procedures. Moreover, similar to progressive-ratio drug self-administration procedures, ICSS data can be used to rank the relative abuse potential of different drugs. Strengths of ICSS in comparison with drug self-administration include 1) potential for simultaneous evaluation of both abuse-related and abuse-limiting effects, 2) flexibility for use with various routes of drug administration or drug vehicles, 3) utility for studies in drug-naive subjects as well as in subjects with controlled levels of prior drug exposure, and 4) utility for studies of drug time course. Taken together, these considerations suggest that ICSS can make significant contributions to the practice of abuse potential testing. Copyright © 2014 by The American Society for Pharmacology and Experimental Therapeutics.

  11. Nonpainful remote electrical stimulation alleviates episodic migraine pain.

    Science.gov (United States)

    Yarnitsky, David; Volokh, Lana; Ironi, Alon; Weller, Boaz; Shor, Merav; Shifrin, Alla; Granovsky, Yelena

    2017-03-28

    To evaluate the efficacy of remote nonpainful electrical upper arm skin stimulation in reducing migraine attack pain. This is a prospective, double-blinded, randomized, crossover, sham-controlled trial. Migraineurs applied skin electrodes to the upper arm soon after attack onset for 20 minutes, at various pulse widths, and refrained from medications for 2 hours. Patients were asked to use the device for up to 20 attacks. In 71 patients (299 treatments) with evaluable data, 50% pain reduction was obtained for 64% of participants based on best of 200-μs, 150-μs, and 100-μs pulse width stimuli per individual vs 26% for sham stimuli. Greater pain reduction was found for active stimulation vs placebo; for those starting at severe or moderate pain, reduction (1) to mild or no pain occurred in 58% (25/43) of participants (66/134 treatments) for the 200-μs stimulation protocol and 24% (4/17; 8/29 treatments) for placebo ( p = 0.02), and (2) to no pain occurred in 30% (13/43) of participants (37/134 treatments) and 6% (1/17; 5/29 treatments), respectively ( p = 0.004). Earlier application of the treatment, within 20 minutes of attack onset, yielded better results: 46.7% pain reduction as opposed to 24.9% reduction when started later ( p = 0.02). Nonpainful remote skin stimulation can significantly reduce migraine pain, especially when applied early in an attack. This is presumably by activating descending inhibition pathways via the conditioned pain modulation effect. This treatment may be proposed as an attractive nonpharmacologic, easy to use, adverse event free, and inexpensive tool to reduce migraine pain. NCT02453399. This study provides Class III evidence that for patients with an acute migraine headache, remote nonpainful electrical stimulation on the upper arm skin reduces migraine pain. © 2017 American Academy of Neurology.

  12. Transcranial Alternating Current Stimulation Attenuates Neuronal Adaptation.

    Science.gov (United States)

    Kar, Kohitij; Duijnhouwer, Jacob; Krekelberg, Bart

    2017-03-01

    We previously showed that brief application of 2 mA (peak-to-peak) transcranial currents alternating at 10 Hz significantly reduces motion adaptation in humans. This is but one of many behavioral studies showing that weak currents applied to the scalp modulate neural processing. Transcranial stimulation has been shown to improve perception, learning, and a range of clinical symptoms. Few studies, however, have measured the neural consequences of transcranial current stimulation. We capitalized on the strong link between motion perception and neural activity in the middle temporal (MT) area of the macaque monkey to study the neural mechanisms that underlie the behavioral consequences of transcranial alternating current stimulation. First, we observed that 2 mA currents generated substantial intracranial fields, which were much stronger in the stimulated hemisphere (0.12 V/m) than on the opposite side of the brain (0.03 V/m). Second, we found that brief application of transcranial alternating current stimulation at 10 Hz reduced spike-frequency adaptation of MT neurons and led to a broadband increase in the power spectrum of local field potentials. Together, these findings provide a direct demonstration that weak electric fields applied to the scalp significantly affect neural processing in the primate brain and that this includes a hitherto unknown mechanism that attenuates sensory adaptation. SIGNIFICANCE STATEMENT Transcranial stimulation has been claimed to improve perception, learning, and a range of clinical symptoms. Little is known, however, how transcranial current stimulation generates such effects, and the search for better stimulation protocols proceeds largely by trial and error. We investigated, for the first time, the neural consequences of stimulation in the monkey brain. We found that even brief application of alternating current stimulation reduced the effects of adaptation on single-neuron firing rates and local field potentials; this mechanistic

  13. Stimulating at the right time: phase-specific deep brain stimulation.

    Science.gov (United States)

    Cagnan, Hayriye; Pedrosa, David; Little, Simon; Pogosyan, Alek; Cheeran, Binith; Aziz, Tipu; Green, Alexander; Fitzgerald, James; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Hariz, Marwan; Friston, Karl J; Denison, Timothy; Brown, Peter

    2017-01-01

    SEE MOLL AND ENGEL DOI101093/AWW308 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Brain regions dynamically engage and disengage with one another to execute everyday actions from movement to decision making. Pathologies such as Parkinson's disease and tremor emerge when brain regions controlling movement cannot readily decouple, compromising motor function. Here, we propose a novel stimulation strategy that selectively regulates neural synchrony through phase-specific stimulation. We demonstrate for the first time the therapeutic potential of such a stimulation strategy for the treatment of patients with pathological tremor. Symptom suppression is achieved by delivering stimulation to the ventrolateral thalamus, timed according to the patient's tremor rhythm. Sustained locking of deep brain stimulation to a particular phase of tremor afforded clinically significant tremor relief (up to 87% tremor suppression) in selected patients with essential tremor despite delivering less than half the energy of conventional high frequency stimulation. Phase-specific stimulation efficacy depended on the resonant characteristics of the underlying tremor network. Selective regulation of neural synchrony through phase-locked stimulation has the potential to both increase the efficiency of therapy and to minimize stimulation-induced side effects. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain.

  14. Development of Fetal Movement between 26 and 36 Weeks’ Gestation in Response to Vibro-acoustic Stimulation

    Directory of Open Access Journals (Sweden)

    Marybeth eGrant-Beuttler

    2011-12-01

    Full Text Available Background: Ultrasound observation of fetal movement has documented general trends in motor development and fetal age when motor response to stimulation is observed. Evaluation of fetal movement quality, in addition to specific motor activity, may improve documentation of motor development and highlight specific motor responses to stimulation. Aims: The aim of this investigation was to assess fetal movement at 26 and 36 weeks gestation during three conditions (baseline, immediate response to vibro-acoustic stimulation (VAS, and post-response. Design: A prospective, longitudinal design was utilized. Subjects: Twelve normally developing fetuses, 8 females and 4 males, were examined with continuous ultrasound imaging. Outcome measures: The Fetal Neurobehavioral Coding System (FENS was used to evaluate the quality of motor activity during 10-second epochs over the three conditions. Results: Seventy-five percent of the fetuses at the 26 week assessment and 100% of the fetuses at the 36 week assessment responded with movement immediately following stimulation. Significant differences in head, fetal breathing, general, limb, and mouthing movements were detected between the 26 week and 36 week assessments. Movement differences between conditions were detected in head, fetal breathing, limb, and mouthing movements. Conclusions: Smoother and more complex movement was observed with fetal maturation. Following VAS stimulation, an immediate increase of large, jerky movements suggest instability in fetal capabilities. Fetal movement quality changes over gestation may reflect sensorimotor synaptogenesis in the central nervous system, while observation of immature movement patterns following VAS stimulation may reflect movement pattern instability.

  15. Music as the Means to Stimulate Novelty and Challenge Seeking in Persons with Intellectual Disability

    Directory of Open Access Journals (Sweden)

    Maria Chong Abdullah

    2013-02-01

    Full Text Available Purpose: The main aim of the study was to determine whether challenge seeking behaviour could be increased by stimulating persons with intellectual disability with music. The intention was also to evaluate whether the participants would attempt to seek challenges when they felt bored with a music experience. Method: Thirty adolescents and young adults with mild to moderate intellectual disability were randomly selected to take part in a repeated-measure experimental design, under three different conditions. In the first condition, the participants were provided adequate challenges through teaching fundamental musical skills. In the second condition, no optimal challenge was provided, and in the third condition, using special strategies, the participants were stimulated to look for novelty and challenge through involvement in creative musical tasks. Level of innovation, as an index of challenge seeking, was measured during the 8 minutes of free choice interval at the end of each condition. Results: Using Friedman’s ANOVA and Wilcoxon signed-rank test, the findings showed that the low and statistically similar levels of challenge seeking behaviour in conditions 1 and 2 significantly increased to a high level in condition 3. It confirmed that participants with intellectual disability are capable of demonstrating challenge seeking behaviour if they are stimulated to do so. The results also confirmed that the tendency to demonstrate challenge seeking behaviour during a boring musical situation was low.

  16. Modulation of mu rhythm desynchronization during motor imagery by transcranial direct current stimulation

    Directory of Open Access Journals (Sweden)

    Kimura Akio

    2010-06-01

    Full Text Available Abstract Background The mu event-related desynchronization (ERD is supposed to reflect motor preparation and appear during motor imagery. The aim of this study is to examine the modulation of ERD with transcranial direct current stimulation (tDCS. Methods Six healthy subjects were asked to imagine their right hand grasping something after receiving a visual cue. Electroencephalograms (EEGs were recorded near the left M1. ERD of the mu rhythm (mu ERD by right hand motor imagery was measured. tDCS (10 min, 1 mA was used to modulate the cortical excitability of M1. Anodal, cathodal, and sham tDCS were tested in each subject with a randomized sequence on different days. Each condition was separated from the preceding one by more than 1 week in the same subject. Before and after tDCS, mu ERD was assessed. The motor thresholds (MT of the left M1 were also measured with transcranial magnetic stimulation. Results Mu ERD significantly increased after anodal stimulation, whereas it significantly decreased after cathodal stimulation. There was a significant correlation between mu ERD and MT. Conclusions Opposing effects on mu ERD based on the orientation of the stimulation suggest that mu ERD is affected by cortical excitability.

  17. Exploring potential social influences on brain potentials during anticipation of tactile stimulation.

    Science.gov (United States)

    Shen, Guannan; Saby, Joni N; Drew, Ashley R; Marshall, Peter J

    2017-03-15

    This study explored interpersonal influences on electrophysiological responses during the anticipation of tactile stimulation. It is well-known that broad, negative-going potentials are present in the event-related potential (ERP) between a forewarning cue and a tactile stimulus. It has also been shown that the alpha-range mu rhythm shows a lateralized desynchronization over central electrode sites during anticipation of tactile stimulation of the hand. The current study used a tactile discrimination task in which a visual cue signaled that an upcoming stimulus would either be delivered 1500ms later to the participant's hand, to a task partner's hand, or to neither person. For the condition in which participants anticipated the tactile stimulation to their own hand, a negative potential (contingent negative variation, CNV) was observed in the ERP at central sites in the 1000ms prior to the tactile stimulus. Significant mu rhythm desynchronization was also present in the same time window. The magnitudes of the ERPs and of the mu desynchronization were greater in the contralateral than in the ipsilateral hemisphere prior to right hand stimulation. Similar ERP and EEG changes were not present when the visual cue indicated that stimulation would be delivered to the task partner or to neither person. The absence of social influences during anticipation of tactile stimulation, and the relationship between the two brain signatures of anticipatory attention (CNV and mu rhythm) are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Transcranial magnetic stimulation in the treatment of chronic widespread pain: a randomized controlled study.

    Science.gov (United States)

    Avery, David H; Zarkowski, Paul; Krashin, Daniel; Rho, Wang-Ku; Wajdik, Chandra; Joesch, Jutta M; Haynor, David R; Buchwald, Dedra; Roy-Byrne, Peter

    2015-03-01

    Our objective was to assess transcranial magnetic stimulation (TMS) in the treatment of chronic widespread pain. Nineteen participants were randomized into 2 groups: one group receiving active TMS (n = 7) and another group receiving sham stimulation (n = 11) applied to the left dorsolateral prefrontal cortex. During sham stimulation, subjects heard a sound similar to the sound heard by those receiving the active treatment and received an active electrical stimulus to the scalp. The stimulation protocol consisted of 15 sessions completed within a 4-week period. Blind assessments were done at baseline and after each 5 sessions followed by blind assessments at 1 week, 1 month, and 3 months after the last TMS sessions. The primary outcome variable was a pain measure, the Gracely Box Intensity Scale (BIRS). The percentage of subjects who guessed that they were receiving TMS was similar in the 2 groups. Both the TMS group and the sham group showed a statistically significant reduction in the BIRS scores from baseline during the acute phase of treatment and the follow-up phase. However, the TMS and sham groups did not differ in the change in the BIRS scores. Although some previous clinical studies and basic science studies of TMS in treating pain are promising, this study found no difference in the analgesic effect of TMS and sham stimulation. Future studies should use a sham condition that attempts to simulate the sound and sensation of the TMS stimulation. Stimulus location and other stimulus parameters should be explored in future studies.

  19. Optical stimulated luminescence (OSL) dating

    International Nuclear Information System (INIS)

    Banerjee, D.

    1999-01-01

    Since the pioneering work by Huntley et al. (1985), optical dating is being increasingly recognised as an important technique for establishing a time frame of deposition of sediments (Aitken, 1998). Optical dating differs from thermoluminescence (TL) dating in that visible/infrared light from lasers or LEDs (light-emitting-diodes) is used as a means of stimulation, in contrast to thermal stimulation. It has several advantages over TL dating: (i) the resetting of the OSL (optically stimulated luminescence) clock is more effective than that of TL clock; for sediments transported under water or in other situations where the sediment grains have undergone inhomogeneous bleaching, this property ensures that ages based on optical dating are generally more reliable than TL ages, (ii) the optical dating technique is non-destructive, and multiple readouts of the optical signal is possible; this feature has resulted in the development of single-aliquot and single-grain protocols (Murray and Wintle, 1999; Banerjee et al. 1999), (iii) the sample is not heated as in TL; thus, spurious luminescence is avoided and there is a significant reduction in blackbody radiation. Dating of materials which change phase on heating is also practical, and finally, (iv) thermal quenching of luminescence is negligible, allowing accurate estimation of kinetic parameters using standard techniques and providing access to deep OSL traps. This characteristic may be helpful in extending the limits of optical dating beyond the last 150 ka from a global point of view

  20. A wireless wearable surface functional electrical stimulator

    Science.gov (United States)

    Wang, Hai-Peng; Guo, Ai-Wen; Zhou, Yu-Xuan; Xia, Yang; Huang, Jia; Xu, Chong-Yao; Huang, Zong-Hao; Lü, Xiao-Ying; Wang, Zhi-Gong

    2017-09-01

    In this paper, a wireless wearable functional electrical stimulator controlled by Android phone with real-time-varying stimulation parameters for multichannel surface functional electrical stimulation application has been developed. It can help post-stroke patients using more conveniently. This study focuses on the prototype design, including the specific wristband concept, circuits and stimulation pulse-generation algorithm. A novel stimulator circuit with a driving stage using a complementary current source technique is proposed to achieve a high-voltage compliance, a large output impedance and an accurate linear voltage-to-current conversion. The size of the prototype has been significantly decreased to 17 × 7.5 × 1 cm3. The performance of the prototype has been tested with a loaded resistor and wrist extension/flexion movement of three hemiplegic patients. According to the experiments, the stimulator can generate four-channel charge-balanced biphasic stimulation with a voltage amplitude up to 60 V, and the pulse frequency and width can be adjusted in real time with a range of 100-600 μs and 20-80 Hz, respectively.

  1. A fully implantable rodent neural stimulator

    Science.gov (United States)

    Perry, D. W. J.; Grayden, D. B.; Shepherd, R. K.; Fallon, J. B.

    2012-02-01

    The ability to electrically stimulate neural and other excitable tissues in behaving experimental animals is invaluable for both the development of neural prostheses and basic neurological research. We developed a fully implantable neural stimulator that is able to deliver two channels of intra-cochlear electrical stimulation in the rat. It is powered via a novel omni-directional inductive link and includes an on-board microcontroller with integrated radio link, programmable current sources and switching circuitry to generate charge-balanced biphasic stimulation. We tested the implant in vivo and were able to elicit both neural and behavioural responses. The implants continued to function for up to five months in vivo. While targeted to cochlear stimulation, with appropriate electrode arrays the stimulator is well suited to stimulating other neurons within the peripheral or central nervous systems. Moreover, it includes significant on-board data acquisition and processing capabilities, which could potentially make it a useful platform for telemetry applications, where there is a need to chronically monitor physiological variables in unrestrained animals.

  2. Comparison of dysphagia before and after deep brain stimulation in Parkinson's disease.

    Science.gov (United States)

    Silbergleit, Alice K; LeWitt, Peter; Junn, Fred; Schultz, Lonni R; Collins, Denise; Beardsley, Tausha; Hubert, Meghan; Trosch, Richard; Schwalb, Jason M

    2012-12-01

    Although dysphagia is a common problem for many Parkinson's disease (PD) patients, the effect of deep brain stimulation (DBS) on swallowing is unclear. Fourteen subjects with advanced PD underwent videofluorographic swallowing studies prior to bilateral DBS of the subthalamic nucleus (STN) and at 3 and 12 months postprocedure. They were tested under several stimulation and medication conditions. Subjects completed the Dysphagia Handicap Index at each time. There was a strong trend toward improved swallowing response for solid intake in the medication-free condition with the stimulator on compared with the stimulator off (P = .0107). Also, there was a trend toward improved oral preparation of thin liquids (P = .0368) in the medication-free condition when the stimulator was on versus off 12 months later. The remaining swallowing parameters showed no change or worsening of swallowing function regardless of stimulator or medication status. Results of the Dysphagia Handicap Index revealed significant improvement in subject self-perception of swallowing 3 and 12 months following the procedure compared with baseline on the functional subscale (P = .020 and P = .010, respectively), the emotional subscale (P = .013 and P = .003, respectively), and the total score (P = .025 and P = .003, respectively). These data suggest that bilateral STN-DBS does not substantively impair swallowing in PD. In addition, it may improve motor sequencing of the oropharyngeal swallow for solid consistencies (which are known to provide increased sensory feedback to assist motor planning of the oropharyngeal swallow). Subjects with advanced PD who are undergoing DBS may perceive significant improvement in swallowing ability despite the lack of objective improvements in swallowing function. Copyright © 2012 Movement Disorder Society.

  3. Is seed conditioning essential for Orobanche germination?

    Science.gov (United States)

    Plakhine, Dina; Ziadna, Hammam; Joel, Daniel M

    2009-05-01

    Parasitic Orobanchaceae germinate only after receiving a chemical stimulus from roots of potential host plants. A preparatory phase of several days that follows seed imbibition, termed conditioning, is known to be required; thereafter the seeds can respond to germination stimulants. The aim of this study was to examine whether conditioning is essential for stimulant receptivity. Non-conditioned seeds of both Orobanche cumana Wallr. and O. aegyptiaca Pers. [syn. Phelipanche aegyptiaca (Pers.) Pomel] were able to germinate in response to chemical stimulation by GR24 even without prior conditioning. Stimulated seeds reached maximal germination rates about 2 weeks after the onset of imbibition, no matter whether the seeds had or had not been conditioned before stimulation. Whereas the lag time between stimulation and germination response of non-conditioned seeds was longer than for conditioned seeds, the total time between imbibition and germination was shorter for the non-conditioned seeds. Unlike the above two species, O. crenata Forsk. was found to require conditioning prior to stimulation. Seeds of O. cumana and O. aegyptiaca are already receptive before conditioning. Thus, conditioning is not involved in stimulant receptivity. A hypothesis is put forward, suggesting that conditioning includes (a) a parasite-specific early phase that allows the imbibed seeds to overcome the stress caused by failing to receive an immediate germination stimulus, and (b) a non-specific later phase that is identical to the pregermination phase between seed imbibition and actual germination that is typical for all higher plants.

  4. Physical injury stimulates aerobic methane emissions from terrestrial plants

    Directory of Open Access Journals (Sweden)

    Z.-P. Wang

    2009-04-01

    Full Text Available Physical injury is common in terrestrial plants as a result of grazing, harvesting, trampling, and extreme weather events. Previous studies demonstrated enhanced emission of non-microbial CH4 under aerobic conditions from plant tissues when they were exposed to increasing UV radiation and temperature. Since physical injury is also a form of environmental stress, we sought to determine whether it would also affect CH4 emissions from plants. Physical injury (cutting stimulated CH4 emission from fresh twigs of Artemisia species under aerobic conditions. More cutting resulted in more CH4 emissions. Hypoxia also enhanced CH4 emission from both uncut and cut Artemisia frigida twigs. Physical injury typically results in cell wall degradation, which may either stimulate formation of reactive oxygen species (ROS or decrease scavenging of them. Increased ROS activity might explain increased CH4 emission in response to physical injury and other forms of stress. There were significant differences in CH4 emissions among 10 species of Artemisia, with some species emitting no detectable CH4 under any circumstances. Consequently, CH4 emissions may be species-dependent and therefore difficult to estimate in nature based on total plant biomass. Our results and those of previous studies suggest that a variety of environmental stresses stimulate CH4 emission from a wide variety of plant species. Global change processes, including climate change, depletion of stratospheric ozone, increasing ground-level ozone, spread of plant pests, and land-use changes, could cause more stress in plants on a global scale, potentially stimulating more CH4 emission globally.

  5. In vitro magnetic stimulation: a simple stimulation device to deliver defined low intensity electromagnetic fields

    Directory of Open Access Journals (Sweden)

    Stephanie Grehl

    2016-11-01

    Full Text Available Non-invasive electromagnetic field brain stimulation (NIBS appears to benefit human neurological and psychiatric conditions, although the optimal stimulation parameters and underlying mechanisms remain unclear. Although in vitro studies have begun to elucidate cellular mechanisms, stimulation is delivered by a range of coils (from commercially available human stimulation coils to laboratory-built circuits so that the electromagnetic fields induced within the tissue to produce the reported effects are ill-defined.Here we develop a simple in vitro stimulation device with plug-and-play features that allow delivery of a range of stimulation parameters. We chose to test low intensity repetitive magnetic stimulation (LI-rMS delivered at 3 frequencies to hindbrain explant cultures containing the olivocerebellar pathway. We used computational modelling to define the parameters of a stimulation circuit and coil that deliver a unidirectional homogeneous magnetic field of known intensity and direction, and therefore a predictable electric field, to the target. We built the coil to be compatible with culture requirements: stimulation within an incubator; a flat surface allowing consistent position and magnetic field direction; location outside the culture plate to maintain sterility and no heating or vibration. Measurements at the explant confirmed the induced magnetic field was homogenous and matched the simulation results. To validate our system we investigated biological effects following LI-rMS at 1 Hz, 10 Hz and biomimetic high frequency (BHFS, which we have previously shown induces neural circuit reorganisation. We found that gene expression was modified by LI-rMS in a frequency-related manner. Four hours after a single 10-minute stimulation session, the number of c-fos positive cells increased, indicating that our stimulation activated the tissue. Also, after 14 days of LI-rMS, the expression of genes normally present in the tissue was differentially

  6. New York Canyon Stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Raemy, Bernard

    2012-06-21

    The New York Canyon Stimulation Project was to demonstrate the commercial application of Enhanced Geothermal System techniques in Buena Vista Valley area of Pershing County, Nevada. From October 2009 to early 2012, TGP Development Company aggressively implemented Phase I of Pre-Stimulation and Site/Wellbore readiness. This included: geological studies; water studies and analyses and procurement of initial permits for drilling. Oversubscription of water rights and lack of water needed for implementation of EGS were identified and remained primary obstacles. Despite extended efforts to find alternative solutions, the water supply circumstances could not be overcome and led TGP to determine a "No Go" decision and initiate project termination in April 2012.

  7. Transcranial direct current stimulation over left inferior frontal cortex improves speech fluency in adults who stutter.

    Science.gov (United States)

    Chesters, Jennifer; Möttönen, Riikka; Watkins, Kate E

    2018-04-01

    See Crinion (doi:10.1093/brain/awy075) for a scientific commentary on this article.Stuttering is a neurodevelopmental condition affecting 5% of children, and persisting in 1% of adults. Promoting lasting fluency improvement in adults who stutter is a particular challenge. Novel interventions to improve outcomes are of value, therefore. Previous work in patients with acquired motor and language disorders reported enhanced benefits of behavioural therapies when paired with transcranial direct current stimulation. Here, we report the results of the first trial investigating whether transcranial direct current stimulation can improve speech fluency in adults who stutter. We predicted that applying anodal stimulation to the left inferior frontal cortex during speech production with temporary fluency inducers would result in longer-lasting fluency improvements. Thirty male adults who stutter completed a randomized, double-blind, controlled trial of anodal transcranial direct current stimulation over left inferior frontal cortex. Fifteen participants received 20 min of 1-mA stimulation on five consecutive days while speech fluency was temporarily induced using choral and metronome-timed speech. The other 15 participants received the same speech fluency intervention with sham stimulation. Speech fluency during reading and conversation was assessed at baseline, before and after the stimulation on each day of the 5-day intervention, and at 1 and 6 weeks after the end of the intervention. Anodal stimulation combined with speech fluency training significantly reduced the percentage of disfluent speech measured 1 week after the intervention compared with fluency intervention alone. At 6 weeks after the intervention, this improvement was maintained during reading but not during conversation. Outcome scores at both post-intervention time points on a clinical assessment tool (the Stuttering Severity Instrument, version 4) also showed significant improvement in the group receiving

  8. Significance of bone scintollography

    International Nuclear Information System (INIS)

    Wioland, M.; Milhaud, G.

    1985-01-01

    Artificial radioactivity enables visualisation of the principal organs in the forms of scintiscans, introduces a new order of sensitivity in quantitative hormonal analysis, thanks to radio-immunology and remains unrivalled in compartmental analyses of the various metabolism. The diagnosis of local skeletal conditions is reviewed and the indications for this quantitative examination are described for the diagnosis of numerous bone metabolic diseases. Finally, mono- and bi- photonic absorptiometry, the latest developments in isotopic techniques, are introduced. They are likely to provide numerical data on the state of mineralisation of bone tissue. The use of these nuclear techniques for the diagnosis and surveillance of osteoporosis is detailed [fr

  9. Performance Enhancement by Brain Stimulation

    Directory of Open Access Journals (Sweden)

    Parisa Gazerani

    2017-09-01

    et al., 2017 has summarized that overall brain stimulation by some techniques including TMS and tDCS seem to speed up motor learning, and motor skills in sport activities. Considering that performance enhancement can be seen (Colzato et al., 2017, one would ask how and by which mechanism. Davis proposed that there would be two ways that brain stimulation could possibly improve sport performance (Davis, 2013. One way is to benefit from brain stimulation before performance to, for instance, reduce stress level or muscle tension or to enhance focus for a quicker action. The other way would be potential use during training for athletic performance that can eventually help athletes to learn motor skills better. Presented research results are mainly based on the experimental set up; therefore, it is important to identify whether physical and mental performance gains under experimental conditions would also be meaningful in a real world competition. To study actual gain by brain stimulation, future investigations must properly be designed, include placebo and control arms, remain blinded until after data analysis, and include objective assessments in addition to subjective outcomes. Time-course of beneficial effect in certain sport competition is not clear. It has been shown that repetitive applications of tDCS can increase the effects of stimulation (Nitsche and Paulus, 2011; but, it is not clear if this is the case for athletic performance. There is no evidence on side effects especially for long term use of these techniques. Overall, these techniques are considered non-invasive and safe (Rossi et al., 2009. Under medical application, it has been notified that some individuals are highly responders while others do not respond well. This might be the case for athletes. Additive or synergistic effects of these techniques together with other techniques or methods of performance enhancement have not yet been investigated either. Therefore, further studies are required to

  10. The effects of high frequency subthalamic stimulation on balance performance and fear of falling in patients with Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Jarnlo Gun-Britt

    2009-04-01

    Full Text Available Abstract Background Balance impairment is one of the most distressing symptoms in Parkinson's disease (PD even with pharmacological treatment (levodopa. A complementary treatment is high frequency stimulation in the subthalamic nucleus (STN. Whether STN stimulation improves postural control is under debate. The aim of this study was to explore the effects of STN stimulation alone on balance performance as assessed with clinical performance tests, subjective ratings of fear of falling and posturography. Methods Ten patients (median age 66, range 59–69 years with bilateral STN stimulation for a minimum of one year, had their anti-PD medications withdrawn overnight. Assessments were done both with the STN stimulation turned OFF and ON (start randomized. In both test conditions, the following were assessed: motor symptoms (descriptive purposes, clinical performance tests, fear of falling ratings, and posturography with and without vibratory proprioceptive disturbance. Results STN stimulation alone significantly (p = 0.002 increased the scores of the Berg balance scale, and the median increase was 6 points. The results of all timed performance tests, except for sharpened Romberg, were significantly (p ≤ 0.016 improved. The patients rated their fear of falling as less severe, and the total score of the Falls-Efficacy Scale(S increased (p = 0.002 in median with 54 points. All patients completed posturography when the STN stimulation was turned ON, but three patients were unable to do so when it was turned OFF. The seven patients with complete data showed no statistical significant difference (p values ≥ 0.109 in torque variance values when comparing the two test situations. This applied both during quiet stance and during the periods with vibratory stimulation, and it was irrespective of visual input and sway direction. Conclusion In this sample, STN stimulation alone significantly improved the results of the clinical performance tests that mimic

  11. Effects of stimulation parameters and electrode location on thresholds for epidural stimulation of cat motor cortex

    Science.gov (United States)

    Wongsarnpigoon, Amorn; Grill, Warren M.

    2011-12-01

    Epidural electrical stimulation (ECS) of the motor cortex is a developing therapy for neurological disorders. Both placement and programming of ECS systems may affect the therapeutic outcome, but the treatment parameters that will maximize therapeutic outcomes and minimize side effects are not known. We delivered ECS to the motor cortex of anesthetized cats and investigated the effects of electrode placement and stimulation parameters on thresholds for evoking motor responses in the contralateral forelimb. Thresholds were inversely related to stimulation frequency and the number of pulses per stimulus train. Thresholds were lower over the forelimb representation in motor cortex (primary site) than surrounding sites (secondary sites), and thresholds at sites 4 mm away. Electrode location and montage influenced the effects of polarity on thresholds: monopolar anodic and cathodic thresholds were not significantly different over the primary site, cathodic thresholds were significantly lower than anodic thresholds over secondary sites and bipolar thresholds were significantly lower with the anode over the primary site than with the cathode over the primary site. A majority of bipolar thresholds were either between or equal to the respective monopolar thresholds, but several bipolar thresholds were greater than or less than the monopolar thresholds of both the anode and cathode. During bipolar stimulation, thresholds were influenced by both electric field superposition and indirect, synaptically mediated interactions. These results demonstrate the influence of stimulation parameters and electrode location during cortical stimulation, and these effects should be considered during the programming of systems for therapeutic cortical stimulation.

  12. Vertex Stimulation as a Control Site for Transcranial Magnetic Stimulation: A Concurrent TMS/fMRI Study

    OpenAIRE

    Jung, JeYoung; Bungert, Andreas; Bowtell, Richard; Jackson, Stephen R.

    2016-01-01

    Background A common control condition for transcranial magnetic stimulation (TMS) studies is to apply stimulation at the vertex. An assumption of vertex stimulation is that it has relatively little influence over on-going brain processes involved in most experimental tasks, however there has been little attempt to measure neural changes linked to vertex TMS. Here we directly test this assumption by using a concurrent TMS/fMRI paradigm in which we investigate fMRI blood-oxygenation-level-depen...

  13. IDEA: Stimulating Oral Production.

    Science.gov (United States)

    Easley, Jacob J.

    1995-01-01

    Presents daily activities that facilitate complete sentence response, promote oral production, and aid the learning of vocabulary in foreign-language classes. Because speech is the primary form of communication in the foreign-language classroom, it is important to stimulate students to converse as soon as possible. (Author/CK)

  14. stimulated BV2 Microglial

    African Journals Online (AJOL)

    2012-03-26

    Mar 26, 2012 ... 2), in LPS-stimulated BV2 microglial cells. The level of NO production was analyzed using Griess reaction. The release of PGE2 was determined using sandwich enzyme-linked immunosorbent assay. The DNA-binding activity of nuclear factor-κB (NF-κB) was measured by electrophoretic mobility shift assay ...

  15. Brain stimulation in migraine.

    Science.gov (United States)

    Brighina, Filippo; Cosentino, Giuseppe; Fierro, Brigida

    2013-01-01

    Migraine is a very prevalent disease with great individual disability and socioeconomic burden. Despite intensive research effort in recent years, the etiopathogenesis of the disease remains to be elucidated. Recently, much importance has been given to mechanisms underlying the cortical excitability that has been suggested to be dysfunctional in migraine. In recent years, noninvasive brain stimulation techniques based on magnetic fields (transcranial magnetic stimulation, TMS) and on direct electrical currents (transcranial direct current stimulation, tDCS) have been shown to be safe and effective tools to explore the issue of cortical excitability, activation, and plasticity in migraine. Moreover, TMS, repetitive TMS (rTMS), and tDCS, thanks to their ability to interfere with and/or modulate cortical activity inducing plastic, persistent effects, have been also explored as potential therapeutic approaches, opening an interesting perspective for noninvasive neurostimulation for both symptomatic and preventive treatment of migraine and other types of headache. In this chapter we critically review evidence regarding the role of noninvasive brain stimulation in the pathophysiology and treatment of migraine, delineating the advantages and limits of these techniques together with potential development and future application. © 2013 Elsevier B.V. All rights reserved.

  16. Free radical-mediated stimulation of tyrosine-specific protein kinase in rat liver plasma membrane

    International Nuclear Information System (INIS)

    Chan, T.M.; Tatoyan, A.; Cheng, E.; Shargill, N.S.; Pleta, M.

    1986-01-01

    Incorporation of 32 P from (γ- 32 P)-ATP into endogenous proteins of plasma membranes isolated from rat liver was significantly increased by several naphthoquinones including menadione. This apparent stimulation of membrane-associated protein kinase activity by these compounds was most striking (up to 6-7 fold) when the synthetic copolymers containing glutamate and tyrosine residues (4:1) was used as substrate. Since tyrosine residues are the only possible phosphate acceptor in the copolymers, the quinone-stimulated liver membrane protein kinase is most likely tyrosine specific. Although not required for protein kinase activity, dithiothreitol (DTT) was necessary for its stimulation by these quinonoid compounds. Hydrolysis of ATP was not significantly affected by quinones under the experimental conditions. Both menadione and vitamin k 5 increased phosphorylation of plasma membrane proteins of molecular weight 45 and 60 kd. The stimulatory effect of menadione on protein phosphorylation was prevented by the addition of superoxide dismutase. Dihydroxyfumerate, which spontaneously produces various radical species, and H 2 O 2 , also stimulated tyrosine-specific protein phosphorylation. DTT was also required for their full effect. It, therefore, appears that quinonone stimulation of tyrosine-specific protein phosphorylation is mediated by oxygen radicals

  17. Functional electrical stimulation of intrinsic laryngeal muscles under varying loads in exercising horses.

    Directory of Open Access Journals (Sweden)

    Jon Cheetham

    Full Text Available Bilateral vocal fold paralysis (BVCP is a life threatening condition and appears to be a good candidate for therapy using functional electrical stimulation (FES. Developing a working FES system has been technically difficult due to the inaccessible location and small size of the sole arytenoid abductor, the posterior cricoarytenoid (PCA muscle. A naturally-occurring disease in horses shares many functional and etiological features with BVCP. In this study, the feasibility of FES for equine vocal fold paralysis was explored by testing arytenoid abduction evoked by electrical stimulation of the PCA muscle. Rheobase and chronaxie were determined for innervated PCA muscle. We then tested the hypothesis that direct muscle stimulation can maintain airway patency during strenuous exercise in horses with induced transient conduction block of the laryngeal motor nerve. Six adult horses were instrumented with a single bipolar intra-muscular electrode in the left PCA muscle. Rheobase and chronaxie were within the normal range for innervated muscle at 0.55±0.38 v and 0.38±0.19 ms respectively. Intramuscular stimulation of the PCA muscle significantly improved arytenoid abduction at all levels of exercise intensity and there was no significant difference between the level of abduction achieved with stimulation and control values under moderate loads. The equine larynx may provide a useful model for the study of bilateral fold paralysis.

  18. Understanding the True Stimulated Reservoir Volume in Shale Reservoirs

    KAUST Repository

    Hussain, Maaruf

    2017-06-06

    Successful exploitation of shale reservoirs largely depends on the effectiveness of hydraulic fracturing stimulation program. Favorable results have been attributed to intersection and reactivation of pre-existing fractures by hydraulically-induced fractures that connect the wellbore to a larger fracture surface area within the reservoir rock volume. Thus, accurate estimation of the stimulated reservoir volume (SRV) becomes critical for the reservoir performance simulation and production analysis. Micro-seismic events (MS) have been commonly used as a proxy to map out the SRV geometry, which could be erroneous because not all MS events are related to hydraulic fracture propagation. The case studies discussed here utilized a fully 3-D simulation approach to estimate the SRV. The simulation approach presented in this paper takes into account the real-time changes in the reservoir\\'s geomechanics as a function of fluid pressures. It is consisted of four separate coupled modules: geomechanics, hydrodynamics, a geomechanical joint model for interfacial resolution, and an adaptive re-meshing. Reservoir stress condition, rock mechanical properties, and injected fluid pressure dictate how fracture elements could open or slide. Critical stress intensity factor was used as a fracture criterion governing the generation of new fractures or propagation of existing fractures and their directions. Our simulations were run on a Cray XC-40 HPC system. The studies outcomes proved the approach of using MS data as a proxy for SRV to be significantly flawed. Many of the observed stimulated natural fractures are stress related and very few that are closer to the injection field are connected. The situation is worsened in a highly laminated shale reservoir as the hydraulic fracture propagation is significantly hampered. High contrast in the in-situ stresses related strike-slip developed thereby shortens the extent of SRV. However, far field nature fractures that were not connected to

  19. Effect of transcranial direct current stimulation on neuroplasticity in corticomotor pathways of the tongue muscles

    DEFF Research Database (Denmark)

    Kothari, Mohit; Stubbs, Peter William; Figlewski, Krystian

    2017-01-01

    To investigate effects of transcranial direct current stimulation (tDCS) on neuroplasticity in corticomotor pathways related to tongue muscles evoked by a training task using the Tongue Drive System (TDS). Using a cross-over design, 13 healthy participants completed two sessions of tDCS while...... performing 30 min of TDS training. Sessions were spaced at least 2 weeks apart and participants randomly received anodal and sham tDCS stimulation in the first session and the other condition in the second session. Single and paired pulse transcranial magnetic stimulation was used to elicit motor evoked...... potentials (MEPs) of the tongue at three time-points; before, immediately after and 30 min after training. Participant-based reports of fun, pain, fatigue and motivation, level of difficulty and effort were evaluated on numerical rating scales. There was no consistent significant effect of anodal and sham...

  20. MR imaging of salivary glands after ductal ligation and stimulation by pilocarpine

    International Nuclear Information System (INIS)

    Patronas, N.J.; Tsuchimoch, M.; Webber, R.; Ruttimann, U.; Fox, P.; Bacher, J.; Schellinger, D.

    1988-01-01

    This paper presents an assessment of the usefulness of MR imaging in pathologic conditions of the salivary gland. The authors performed MR imaging in six dogs after ductal ligation on one side, followed by secretory stimulation with intraperitoneal injection of pilocarpine (5 mg/kg). On the images obtained after ductal ligation and before stimulation, there was no significant change in the signal intensity on either side. After injection of pilocarpine, however, T2-weighted images showed an obvious increase in signal intensity of the ligated gland in every instance. Their results indicate that MR images obtained after pilocarpine stimulation will be useful to study patients with ductal obstruction and that they may provide an objective basis for a noninvasive diagnostic test for unilateral stenosis

  1. Management of overactive bladder review: the role of percutaneous tibial nerve stimulation

    Directory of Open Access Journals (Sweden)

    Elita Wibisono

    2017-01-01

    Full Text Available Overactive bladder (OAB is a common condition that is experienced by around 455 million people (11% of the world population and associated with significant impact in patients’ quality of life. The first line treatments of OAB are conservative treatment and anti-muscarinic medication. For the refractory OAB patients, the treatment options available are surgical therapy, electrical stimulation, and botulinum toxin injection. Among them, percutaneous tibial nerve stimulation (PTNS is a minimally invasive option that aims to stimulate sacral nerve plexus, a group of nerve that is responsible for regulation of bladder function. After its approval by food and drug administration (FDA in 2007, PTNS revealed considerable promise in OAB management. In this review, several non-comparative and comparative studies comparing PTNS with sham procedure, anti-muscarinic therapy, and multimodal therapy combining PTNS and anti-muscarinic had supportive data to this consideration.

  2. Significant Tsunami Events

    Science.gov (United States)

    Dunbar, P. K.; Furtney, M.; McLean, S. J.; Sweeney, A. D.

    2014-12-01

    Tsunamis have inflicted death and destruction on the coastlines of the world throughout history. The occurrence of tsunamis and the resulting effects have been collected and studied as far back as the second millennium B.C. The knowledge gained from cataloging and examining these events has led to significant changes in our understanding of tsunamis, tsunami sources, and methods to mitigate the effects of tsunamis. The most significant, not surprisingly, are often the most devastating, such as the 2011 Tohoku, Japan earthquake and tsunami. The goal of this poster is to give a brief overview of the occurrence of tsunamis and then focus specifically on several significant tsunamis. There are various criteria to determine the most significant tsunamis: the number of deaths, amount of damage, maximum runup height, had a major impact on tsunami science or policy, etc. As a result, descriptions will include some of the most costly (2011 Tohoku, Japan), the most deadly (2004 Sumatra, 1883 Krakatau), and the highest runup ever observed (1958 Lituya Bay, Alaska). The discovery of the Cascadia subduction zone as the source of the 1700 Japanese "Orphan" tsunami and a future tsunami threat to the U.S. northwest coast, contributed to the decision to form the U.S. National Tsunami Hazard Mitigation Program. The great Lisbon earthquake of 1755 marked the beginning of the modern era of seismology. Knowledge gained from the 1964 Alaska earthquake and tsunami helped confirm the theory of plate tectonics. The 1946 Alaska, 1952 Kuril Islands, 1960 Chile, 1964 Alaska, and the 2004 Banda Aceh, tsunamis all resulted in warning centers or systems being established.The data descriptions on this poster were extracted from NOAA's National Geophysical Data Center (NGDC) global historical tsunami database. Additional information about these tsunamis, as well as water level data can be found by accessing the NGDC website www.ngdc.noaa.gov/hazard/

  3. The stimulation of hematosis on short-term and prolong irradiation

    International Nuclear Information System (INIS)

    Tukhtaev, T.M.

    1978-01-01

    This book studies the stimulation of hematosis on short-term and prolong irradiation, pathogenetic mechanisms of lesion and reconstruction of hematosis at critical radiation sickness, action hematosis stimulators in short-term irradiation conditions

  4. Smile and laughter induction and intraoperative predictors of response to deep brain stimulation for obsessive-compulsive disorder.

    Science.gov (United States)

    Haq, Ihtsham U; Foote, Kelly D; Goodman, Wayne G; Wu, Samuel S; Sudhyadhom, Atchar; Ricciuti, Nicola; Siddiqui, Mustafa S; Bowers, Dawn; Jacobson, Charles E; Ward, Herbert; Okun, Michael S

    2011-01-01

    We recently treated six patients for OCD utilizing deep brain stimulation (DBS) of the anterior limb of the internal capsule and the nucleus accumbens region (ALIC-NA). We individually tested leads via a scripted intraoperative protocol designed to determine DBS-induced side effects and mood changes. We previously published qualitative data regarding our observations of induced emotional behaviors in our first five subjects. We have now studied these same behaviors in the full cohort of six patients over 2 years of follow-up and have examined the relationship of these behaviors to intraoperative mood changes and postoperative clinical outcomes. Five patients experienced at least one smile response during testing. At higher voltages of stimulation, some of these smiles progressed to natural laughter. Smiles and laughter were associated with mood elevation. At stimulation locations at which smiles were observed, voltage and mood were significantly correlated (p=0.0004 for right brain and plaughter-inducing sites were located relatively medial, posterior, and deep in the ALIC-NA. The presence of stimulation induced laughter predicted improvement in OCD symptoms at 2 years. The higher the percentage of laugh conditions experienced in an individual patient, the greater the reduction in YBOCS (24 months, p=0.034). Other correlations between clinical outcomes and percent of smile/laugh conditions were not significant. These stimulation-induced behaviors were less frequently observed with 1 and 2-month postoperative test stimulation and were not observed at subsequent test stimulation sessions. Intraoperative stimulation-induced laughter may predict long-term OCD response to DBS. Identifying other potential response predictors for OCD will become increasingly important as more patients are implanted with DBS devices. A larger study is needed to better delineate the relationship between induced intraoperative and postoperative emotional behavior and clinical outcome in

  5. Smile and Laughter Induction and Intraoperative Predictors of Response to Deep Brain Stimulation for Obsessive Compulsive Disorder

    Science.gov (United States)

    Haq, Ihtsham U; Foote, Kelly D; Goodman, Wayne G; Wu, Samuel S; Sudhyadhom, Atchar; Ricciutti, Nicola; Siddiqui, Mustafa S.; Bowers, Dawn; Jacobson, Charles E; Ward, Herbert; Okun, Michael S

    2010-01-01

    We recently treated six patients for OCD utilizing deep brain stimulation (DBS) of the anterior limb of the internal capsule and the nucleus accumbens region (ALIC-NA). We individually tested leads via a scripted intraoperative protocol designed to determine DBS-induced side effects and mood changes. We previously published qualitative data regarding our observations of induced emotional behaviors in our first five subjects. We have now studied these same behaviors in the full cohort of six patients over two years of follow-up and have examined the relationship of these behaviors to intraoperative mood changes and postoperative clinical outcomes. Five patients experienced at least one smile response during testing. At higher voltages of stimulation some of these smiles progressed to natural laughter. Smiles and laughter were associated with mood elevation. At stimulation locations at which smiles were observed, voltage and mood were significantly correlated (p=0.0004 for right brain and plaughter-inducing sites were located relatively medial, posterior, and deep in the ALIC-NA. The presence of stimulation induced laughter predicted improvement in OCD symptoms at two years. The higher the percentage of laugh conditions experienced in an individual patient, the greater the reduction in YBOCS (24 months, p=0.034). Other correlations between clinical outcomes and percent of smile/laugh conditions were not significant. These stimulation-induced behaviors were less frequently observed with one and two-month postoperative test stimulation and were not observed at subsequent test stimulation sessions. Intraoperative stimulation-induced laughter may predict long-term OCD response to DBS. Identifying other potential response predictors for OCD will become increasingly important as more patients are implanted with DBS devices. A larger study is needed to better delineate the relationship between induced intraoperative and postoperative emotional behavior and clinical outcome

  6. Epilepsia partialis continua responsive to neocortical electrical stimulation.

    Science.gov (United States)

    Valentin, Antonio; Ughratdar, Ismail; Cheserem, Beverly; Morris, Robert; Selway, Richard; Alarcon, Gonzalo

    2015-08-01

    Epilepsia partialis continua (EPC), defined as a syndrome of continuous focal jerking, is a rare form of focal status epilepticus that usually affects a distal limb, and when prolonged, can produce long-lasting deficits in limb function. Substantial electrophysiologic evidence links the origin of EPC to the motor cortex; thus surgical resection carries the risk of significant handicap. We present two patients with focal, drug-resistant EPC, who were admitted for intracranial video-electroencephalography monitoring to elucidate the location of the epileptogenic focus and identification of eloquent motor cortex with functional mapping. In both cases, the focus resided at or near eloquent motor cortex and therefore precluded resective surgery. Chronic cortical stimulation delivered through subdural strips at the seizure focus (continuous stimulation at 60-130 Hz, 2-3 mA) resulted in >90% reduction in seizures and abolition of the EPC after a follow-up of 22 months in both patients. Following permanent implantation of cortical stimulators, no adverse effects were noted. EPC restarted when intensity was reduced or batteries depleted. Battery replacement restored previous improvement. This two-case report opens up avenues for the treatment of this debilitating condition. Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.

  7. Electronically switchable sham transcranial magnetic stimulation (TMS system.

    Directory of Open Access Journals (Sweden)

    Fumiko Hoeft

    Full Text Available Transcranial magnetic stimulation (TMS is increasingly being used to demonstrate the causal links between brain and behavior in humans. Further, extensive clinical trials are being conducted to investigate the therapeutic role of TMS in disorders such as depression. Because TMS causes strong peripheral effects such as auditory clicks and muscle twitches, experimental artifacts such as subject bias and placebo effect are clear concerns. Several sham TMS methods have been developed, but none of the techniques allows one to intermix real and sham TMS on a trial-by-trial basis in a double-blind manner. We have developed an attachment that allows fast, automated switching between Standard TMS and two types of control TMS (Sham and Reverse without movement of the coil or reconfiguration of the setup. We validate the setup by performing mathematical modeling, search-coil and physiological measurements. To see if the stimulus conditions can be blinded, we conduct perceptual discrimination and sensory perception studies. We verify that the physical properties of the stimulus are appropriate, and that successive stimuli do not contaminate each other. We find that the threshold for motor activation is significantly higher for Reversed than for Standard stimulation, and that Sham stimulation entirely fails to activate muscle potentials. Subjects and experimenters perform poorly at discriminating between Sham and Standard TMS with a figure-of-eight coil, and between Reverse and Standard TMS with a circular coil. Our results raise the possibility of utilizing this technique for a wide range of applications.

  8. Assessment of the risk of fall, related to visual stimulation, in patients with central vestibular disorders.

    Science.gov (United States)

    Suárez, H; Musé, P; Suárez, A; Arocena, M

    2001-01-01

    In order to assess the influence of visual stimulation in the triggering of imbalance and falls in the elderly population, the postural responses of 18 elderly patients with central vestibular disorders and clinical evidence of instability and falls were studied while receiving different types of visual stimuli. The stimulation conditions were: (i) no specific stimuli; (ii) smooth pursuit with pure sinusoids of 0.2 Hz as foveal stimulation; and (iii) optokinetic stimulation (OK) as retinal stimuli. Using a platform AMTI Accusway platform, the 95% confidence ellipse (CE) and sway velocity (SV) were evaluated with a scalogram using wavelets in order to assess the relationship between time and frequency in postural control. Velocity histograms were also constructed in order to observe the distribution of velocity values during the recording. A non-homogeneous postural behavior after visual stimulation was found among this population. In five of the patients the OK stimulation generated: (i) significantly higher average values of CE ( > 3.4+/-0.69 cm2); (ii) a significant increase in the average values of the SV ( > 3.89+/-1.15 cm/s) and a velocity histogram with a homogeneous distribution between 0 and 18 cm/s; and (iii) a scalogram with sway frequencies of up to 4 Hz distributed in both the X and Y directions (backwards and forwards and lateral) during visual stimulation with arbitrary units of energy density > 5. These three qualitative and quantitative aspects could be "markers" of visual dependence in the triggering of the mechanism of lack of equilibrium and hence falls in some elderly patients and should be considered in order to prevent falls and also to assist in the rehabilitation program of these patients.

  9. Selective left, right and bilateral stimulation of subthalamic nuclei in Parkinson's disease: differential effects on motor, speech and language function.

    Science.gov (United States)

    Schulz, Geralyn M; Hosey, Lara A; Bradberry, Trent J; Stager, Sheila V; Lee, Li-Ching; Pawha, Rajesh; Lyons, Kelly E; Metman, Leo Verhagen; Braun, Allen R

    2012-01-01

    Deep brain stimulation (DBS) of the subthalamic nucleus improves the motor symptoms of Parkinson's disease, but may produce a worsening of speech and language performance at rates and amplitudes typically selected in clinical practice. The possibility that these dissociated effects might be modulated by selective stimulation of left and right STN has never been systematically investigated. To address this issue, we analyzed motor, speech and language functions of 12 patients implanted with bilateral stimulators configured for optimal motor responses. Behavioral responses were quantified under four stimulator conditions: bilateral DBS, right-only DBS, left-only DBS and no DBS. Under bilateral and left-only DBS conditions, our results exhibited a significant improvement in motor symptoms but worsening of speech and language. These findings contribute to the growing body of literature demonstrating that bilateral STN DBS compromises speech and language function and suggests that these negative effects may be principally due to left-sided stimulation. These findings may have practical clinical consequences, suggesting that clinicians might optimize motor, speech and language functions by carefully adjusting left- and right-sided stimulation parameters.

  10. Effects of external trigeminal nerve stimulation (eTNS) on laser evoked cortical potentials (LEP): A pilot study in migraine patients and controls.

    Science.gov (United States)

    Vecchio, Eleonora; Gentile, Eleonora; Franco, Giovanni; Ricci, Katia; de Tommaso, Marina

    2017-01-01

    Background Transcutaneous external supraorbital nerve stimulation has emerged as a treatment option for primary headache disorders, though its action mechanism is still unclear. Study aim In this randomized, sham-controlled pilot study we aimed to test the effects of a single external transcutaneous nerve stimulation session on pain perception and cortical responses induced by painful laser stimuli delivered to the right forehead and the right hand in a cohort of migraine without aura patients and healthy controls. Methods Seventeen migraine without aura patients and 21 age- and sex-matched controls were selected and randomly assigned to a real or sham external transcutaneous nerve stimulation single stimulation session. The external transcutaneous nerve stimulation was delivered with a self-adhesive electrode placed on the forehead and generating a 60 Hz pulse at 16 mA intensity for 20 minutes. For sham stimulation, we used 2 mA intensity. Laser evoked responses were recorded from 21 scalp electrodes in basal condition (T0), during external transcutaneous nerve stimulation and sham stimulation (T1), and immediately after these (T2). The laser evoked responses were analyzed by LORETA software. Results The real external transcutaneous nerve stimulation reduced the trigeminal N2P2 amplitude in migraine and control groups significantly in respect to placebo. The real stimulation was associated with lower activity in the anterior cingulate cortex under trigeminal laser stimuli. The pattern of LEP-reduced habituation was reverted by real and sham transcutaneous stimulation in migraine patients. Conclusions The present results could suggest that the external transcutaneous nerve stimulation may interfere with the threshold and the extent of trigeminal system activation, with a mechanism of potential utility in the resolution and prevention of migraine attacks.

  11. A trial of scheduled deep brain stimulation for Tourette syndrome: moving away from continuous deep brain stimulation paradigms.

    Science.gov (United States)

    Okun, Michael S; Foote, Kelly D; Wu, Samuel S; Ward, Herbert E; Bowers, Dawn; Rodriguez, Ramon L; Malaty, Irene A; Goodman, Wayne K; Gilbert, Donald M; Walker, Harrison C; Mink, Jonathan W; Merritt, Stacy; Morishita, Takashi; Sanchez, Justin C

    2013-01-01

    To collect the information necessary to design the methods and outcome variables for a larger trial of scheduled deep brain stimulation (DBS) for Tourette syndrome. We performed a small National Institutes of Health-sponsored clinical trials planning study of the safety and preliminary efficacy of implanted DBS in the bilateral centromedian thalamic region. The study used a cranially contained constant-current device and a scheduled, rather than the classic continuous, DBS paradigm. Baseline vs 6-month outcomes were collected and analyzed. In addition, we compared acute scheduled vs acute continuous vs off DBS. A university movement disorders center. Five patients with implanted DBS. A 50% improvement in the Yale Global Tic Severity Scale (YGTSS) total score. RESULTS Participating subjects had a mean age of 34.4 (range, 28-39) years and a mean disease duration of 28.8 years. No significant adverse events or hardware-related issues occurred. Baseline vs 6-month data revealed that reductions in the YGTSS total score did not achieve the prestudy criterion of a 50% improvement in the YGTSS total score on scheduled stimulation settings. However, statistically significant improvements were observed in the YGTSS total score (mean [SD] change, -17.8 [9.4]; P=.01), impairment score (-11.3 [5.0]; P=.007), and motor score (-2.8 [2.2]; P=.045); the Modified Rush Tic Rating Scale Score total score (-5.8 [2.9]; P=.01); and the phonic tic severity score (-2.2 [2.6]; P=.04). Continuous, off, and scheduled stimulation conditions were assessed blindly in an acute experiment at 6 months after implantation. The scores in all 3 conditions showed a trend for improvement. Trends for improvement also occurred with continuous and scheduled conditions performing better than the off condition. Tic suppression was commonly seen at ventral (deep) contacts, and programming settings resulting in tic suppression were commonly associated with a subjective feeling of calmness. This study provides

  12. Effects of pulsed magnetic stimulation on tumor development and immune functions in mice.

    Science.gov (United States)

    Yamaguchi, Sachiko; Ogiue-Ikeda, Mari; Sekino, Masaki; Ueno, Shoogo

    2006-01-01

    We investigated the effects of pulsed magnetic stimulation on tumor development processes and immune functions in mice. A circular coil (inner diameter = 15 mm, outer diameter = 75 mm) was used in the experiments. Stimulus conditions were pulse width = 238 micros, peak magnetic field = 0.25 T (at the center of the coil), frequency = 25 pulses/s, 1,000 pulses/sample/day and magnetically induced eddy currents in mice = 0.79-1.54 A/m(2). In an animal study, B16-BL6 melanoma model mice were exposed to the pulsed magnetic stimulation for 16 days from the day of injection of cancer cells. A tumor growth study revealed a significant tumor weight decrease in the stimulated group (54% of the sham group). In a cellular study, B16-BL6 cells were also exposed to the magnetic field (1,000 pulses/sample, and eddy currents at the bottom of the dish = 2.36-2.90 A/m(2)); however, the magnetically induced eddy currents had no effect on cell viabilities. Cytokine production in mouse spleens was measured to analyze the immunomodulatory effect after the pulsed magnetic stimulation. tumor necrosis factor (TNF-alpha) production in mouse spleens was significantly activated after the exposure of the stimulus condition described above. These results showed the first evidence of the anti-tumor effect and immunomodulatory effects brought about by the application of repetitive magnetic stimulation and also suggested the possible relationship between anti-tumor effects and the increase of TNF-alpha levels caused by pulsed magnetic stimulation.

  13. Monitoring transcranial direct current stimulation induced changes in cortical excitability during the serial reaction time task.

    Science.gov (United States)

    Ambrus, Géza Gergely; Chaieb, Leila; Stilling, Roman; Rothkegel, Holger; Antal, Andrea; Paulus, Walter

    2016-03-11

    The measurement of the motor evoked potential (MEP) amplitudes using single pulse transcranial magnetic stimulation (TMS) is a common method to observe changes in motor cortical excitability. The level of cortical excitability has been shown to change during motor learning. Conversely, motor learning can be improved by using anodal transcranial direct current stimulation (tDCS). In the present study, we aimed to monitor cortical excitability changes during an implicit motor learning paradigm, a version of the serial reaction time task (SRTT). Responses from the first dorsal interosseous (FDI) and forearm flexor (FLEX) muscles were recorded before, during and after the performance of the SRTT. Online measurements were combined with anodal, cathodal or sham tDCS for the duration of the SRTT. Negative correlations between the amplitude of online FDI MEPs and SRTT reaction times (RTs) were observed across the learning blocks in the cathodal condition (higher average MEP amplitudes associated with lower RTs) but no significant differences in the anodal and sham conditions. tDCS did not have an impact on SRTT performance, as would be predicted based on previous studies. The offline before-after SRTT MEP amplitudes showed an increase after anodal and a tendency to decrease after cathodal stimulation, but these changes were not significant. The combination of different interventions during tDCS might result in reduced efficacy of the stimulation that in future studies need further attention. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. Brain stimulation methods to treat tobacco addiction.

    Science.gov (United States)

    Wing, Victoria C; Barr, Mera S; Wass, Caroline E; Lipsman, Nir; Lozano, Andres M; Daskalakis, Zafiris J; George, Tony P

    2013-05-01

    Tobacco smoking is the leading cause of preventable deaths worldwide, but many smokers are simply unable to quit. Psychosocial and pharmaceutical treatments have shown modest results on smoking cessation rates, but there is an urgent need to develop treatments with greater efficacy. Brain stimulation methods are gaining increasing interest as possible addiction therapeutics. The purpose of this paper is to review the studies that have evaluated brain stimulation techniques on tobacco addiction, and discuss future directions for research in this novel area of addiction interventions. Electronic and manual literature searches identified fifteen studies that administered repetitive transcranial magnetic stimulation (rTMS), cranial electrostimulation (CES), transcranial direct current stimulation (tDCS) or deep brain stimulation (DBS). rTMS was found to be the most well studied method with respect to tobacco addiction. Results indicate that rTMS and tDCS targeted to the dorsolateral prefrontal cortex (DLPFC) were the most efficacious in reducing tobacco cravings, an effect that may be mediated through the brain reward system involved in tobacco addiction. While rTMS was shown to reduce consumption of cigarettes, as yet no brain stimulation technique has been shown to significantly increase abstinence rates. It is possible that the therapeutic effects of rTMS and tDCS may be improved by optimization of stimulation parameters and increasing the duration of treatment. Although further studies are needed to confirm the ability of brain stimulation methods to treat tobacco addiction, this review indicates that rTMS and tDCS both represent potentially novel treatment modalities. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Bihemispheric stimulation over left and right inferior frontal region enhances recovery from apraxia of speech in chronic aphasia.

    Science.gov (United States)

    Marangolo, Paola; Fiori, Valentina; Cipollari, Susanna; Campana, Serena; Razzano, Carmelina; Di Paola, Margherita; Koch, Giacomo; Caltagirone, Carlo

    2013-11-01

    Several studies have already shown that transcranial direct current stimulation (tDCS) is a useful tool for enhancing recovery in aphasia. However, all tDCS studies have previously investigated the effects using unihemisperic stimulation. No reports to date have examined the role of bihemispheric tDCS on aphasia recovery. Here, eight aphasic persons with apraxia of speech underwent intensive language therapy in two different conditions: real bihemispheric anodic ipsilesional stimulation over the left Broca's area and cathodic contralesional stimulation over the right homologue of Broca's area, and a sham condition. In both conditions, patients underwent concurrent language therapy for their apraxia of speech. The language treatment lasted 10 days (Monday to Friday, then weekend off, then Monday to Friday). There was a 14-day intersession interval between the real and the sham conditions. In all patients, language measures were collected before (T0), at the end of (T10) and 1 week after the end of (F/U) treatment. Results showed that after simultaneous excitatory stimulation to the left frontal hemisphere and inhibitory stimulation to the right frontal hemisphere regions, patients exhibited a significant recovery not only in terms of better accuracy and speed in articulating the treated stimuli but also in other language tasks (picture description, noun and verb naming, word repetition, word reading) which persisted in the follow-up session. Taken together, these data suggest that bihemispheric anodic ipsilesional and cathodic contralesional stimulation in chronic aphasia patients may affect the treated function, resulting in a positive influence on different language tasks. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  16. Safety significance evaluation system

    International Nuclear Information System (INIS)

    Lew, B.S.; Yee, D.; Brewer, W.K.; Quattro, P.J.; Kirby, K.D.

    1991-01-01

    This paper reports that the Pacific Gas and Electric Company (PG and E), in cooperation with ABZ, Incorporated and Science Applications International Corporation (SAIC), investigated the use of artificial intelligence-based programming techniques to assist utility personnel in regulatory compliance problems. The result of this investigation is that artificial intelligence-based programming techniques can successfully be applied to this problem. To demonstrate this, a general methodology was developed and several prototype systems based on this methodology were developed. The prototypes address U.S. Nuclear Regulatory Commission (NRC) event reportability requirements, technical specification compliance based on plant equipment status, and quality assurance assistance. This collection of prototype modules is named the safety significance evaluation system

  17. Predicting significant torso trauma.

    Science.gov (United States)

    Nirula, Ram; Talmor, Daniel; Brasel, Karen

    2005-07-01

    Identification of motor vehicle crash (MVC) characteristics associated with thoracoabdominal injury would advance the development of automatic crash notification systems (ACNS) by improving triage and response times. Our objective was to determine the relationships between MVC characteristics and thoracoabdominal trauma to develop a torso injury probability model. Drivers involved in crashes from 1993 to 2001 within the National Automotive Sampling System were reviewed. Relationships between torso injury and MVC characteristics were assessed using multivariate logistic regression. Receiver operating characteristic curves were used to compare the model to current ACNS models. There were a total of 56,466 drivers. Age, ejection, braking, avoidance, velocity, restraints, passenger-side impact, rollover, and vehicle weight and type were associated with injury (p < 0.05). The area under the receiver operating characteristic curve (83.9) was significantly greater than current ACNS models. We have developed a thoracoabdominal injury probability model that may improve patient triage when used with ACNS.

  18. Gas revenue increasingly significant

    International Nuclear Information System (INIS)

    Megill, R.E.

    1991-01-01

    This paper briefly describes the wellhead prices of natural gas compared to crude oil over the past 70 years. Although natural gas prices have never reached price parity with crude oil, the relative value of a gas BTU has been increasing. It is one of the reasons that the total amount of money coming from natural gas wells is becoming more significant. From 1920 to 1955 the revenue at the wellhead for natural gas was only about 10% of the money received by producers. Most of the money needed for exploration, development, and production came from crude oil. At present, however, over 40% of the money from the upstream portion of the petroleum industry is from natural gas. As a result, in a few short years natural gas may become 50% of the money revenues generated from wellhead production facilities

  19. [Transcranial magnetic stimulation and motor cortex stimulation in neuropathic pain].

    Science.gov (United States)

    Mylius, V; Ayache, S S; Teepker, M; Kappus, C; Kolodziej, M; Rosenow, F; Nimsky, C; Oertel, W H; Lefaucheur, J P

    2012-12-01

    Non-invasive and invasive cortical stimulation allows the modulation of therapy-refractory neuropathic pain. High-frequency repetitive transcranial magnetic stimulation (rTMS) of the contralateral motor cortex yields therapeutic effects at short-term and predicts the benefits of epidural motor cortex stimulation (MCS). The present article summarizes the findings on application, mechanisms and therapeutic effects of cortical stimulation in neuropathic pain.

  20. Stimulating thought: a functional MRI study of transcranial direct current stimulation in schizophrenia.

    Science.gov (United States)

    Orlov, Natasza D; O'Daly, Owen; Tracy, Derek K; Daniju, Yusuf; Hodsoll, John; Valdearenas, Lorena; Rothwell, John; Shergill, Sukhi S

    2017-09-01

    Individuals with schizophrenia typically suffer a range of cognitive deficits, including prominent deficits in working memory and executive function. These difficulties are strongly predictive of functional outcomes, but there is a paucity of effective therapeutic interventions targeting these deficits. Transcranial direct current stimulation is a novel neuromodulatory technique with emerging evidence of potential pro-cognitive effects; however, there is limited understanding of its mechanism. This was a double-blind randomized sham controlled pilot study of transcranial direct current stimulation on a working memory (n-back) and executive function (Stroop) task in 28 individuals with schizophrenia using functional magnetic resonance imaging. Study participants received 30 min of real or sham transcranial direct current stimulation applied to the left frontal cortex. The 'real' and 'sham' groups did not differ in online working memory task performance, but the transcranial direct current stimulation group demonstrated significant improvement in performance at 24 h post-transcranial direct current stimulation. Transcranial direct current stimulation was associated with increased activation in the medial frontal cortex beneath the anode; showing a positive correlation with consolidated working memory performance 24 h post-stimulation. There was reduced activation in the left cerebellum in the transcranial direct current stimulation group, with no change in the middle frontal gyrus or parietal cortices. Improved performance on the executive function task was associated with reduced activity in the anterior cingulate cortex. Transcranial direct current stimulation modulated functional activation in local task-related regions, and in more distal nodes in the network. Transcranial direct current stimulation offers a potential novel approach to altering frontal cortical activity and exerting pro-cognitive effects in schizophrenia. © The Author (2017). Published by Oxford

  1. Pudendal nerve stimulation and block by a wireless-controlled implantable stimulator in cats.

    Science.gov (United States)

    Yang, Guangning; Wang, Jicheng; Shen, Bing; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2014-07-01

    The study aims to determine the functionality of a wireless-controlled implantable stimulator designed for stimulation and block of the pudendal nerve. In five cats under α-chloralose anesthesia, the stimulator was implanted underneath the skin on the left side in the lower back along the sacral spine. Two tripolar cuff electrodes were implanted bilaterally on the pudendal nerves in addition to one bipolar cuff electrode that was implanted on the left side central to the tripolar cuff electrode. The stimulator provided high-frequency (5-20 kHz) biphasic stimulation waveforms to the two tripolar electrodes and low-frequency (1-100 Hz) rectangular pulses to the bipolar electrode. Bladder and urethral pressures were measured to determine the effects of pudendal nerve stimulation (PNS) or block. The maximal (70-100 cmH2O) urethral pressure generated by 20-Hz PNS applied via the bipolar electrode was completely eliminated by the pudendal nerve block induced by the high-frequency stimulation (6-15 kHz, 6-10 V) applied via the two tripolar electrodes. In a partially filled bladder, 20-30 Hz PNS (2-8 V, 0.2 ms) but not 5 Hz stimulation applied via the bipolar electrode elicited a large sustained bladder contraction (45.9 ± 13.4 to 52.0 ± 22 cmH2O). During cystometry, the 5 Hz PNS significantly (p < 0.05) increased bladder capacity to 176.5 ± 27.1% of control capacity. The wireless-controlled implantable stimulator successfully generated the required waveforms for stimulation and block of pudendal nerve, which will be useful for restoring bladder functions after spinal cord injury. © 2013 International Neuromodulation Society.

  2. Magnetic fields in noninvasive brain stimulation.

    Science.gov (United States)

    Vidal-Dourado, Marcos; Conforto, Adriana Bastos; Caboclo, Luis Otávio Sales Ferreira; Scaff, Milberto; Guilhoto, Laura Maria de Figueiredo Ferreira; Yacubian, Elza Márcia Targas

    2014-04-01

    The idea that magnetic fields could be used therapeutically arose 2000 years ago. These therapeutic possibilities were expanded after the discovery of electromagnetic induction by the Englishman Michael Faraday and the American Joseph Henry. In 1896, Arsène d'Arsonval reported his experience with noninvasive brain magnetic stimulation to the scientific French community. In the second half of the 20th century, changing magnetic fields emerged as a noninvasive tool to study the nervous system and to modulate neural function. In 1985, Barker, Jalinous, and Freeston presented transcranial magnetic stimulation, a relatively focal and painless technique. Transcranial magnetic stimulation has been proposed as a clinical neurophysiology tool and as a potential adjuvant treatment for psychiatric and neurologic conditions. This article aims to contextualize the progress of use of magnetic fields in the history of neuroscience and medical sciences, until 1985.

  3. Pathways of translation: deep brain stimulation.

    Science.gov (United States)

    Gionfriddo, Michael R; Greenberg, Alexandra J; Wahegaonkar, Abhijeet L; Lee, Kendall H

    2013-12-01

    Electrical stimulation of the brain has a 2000 year history. Deep brain stimulation (DBS), one form of neurostimulation, is a functional neurosurgical approach in which a high-frequency electrical current stimulates targeted brain structures for therapeutic benefit. It is an effective treatment for certain neuropathologic movement disorders and an emerging therapy for psychiatric conditions and epilepsy. Its translational journey did not follow the typical bench-to-bedside path, but rather reversed the process. The shift from ancient and medieval folkloric remedy to accepted medical practice began with independent discoveries about electricity during the 19th century and was fostered by technological advances of the 20th. In this paper, we review that journey and discuss how the quest to expand its applications and improve outcomes is taking DBS from the bedside back to the bench. © 2013 Wiley Periodicals, Inc.

  4. Transcranial direct current stimulation (tDCS) modulation of picture naming and word reading: A meta-analysis of single session tDCS applied to healthy participants.

    Science.gov (United States)

    Westwood, Samuel J; Romani, Cristina

    2017-09-01

    Recent reviews quantifying the effects of single sessions of transcranial direct current stimulation (or tDCS) in healthy volunteers find only minor effects on cognition despite the popularity of this technique. Here, we wanted to quantify the effects of tDCS on language production tasks that measure word reading and picture naming. We reviewed 14 papers measuring tDCS effects across a total of 96 conditions to a) quantify effects of conventional stimulation on language regions (i.e., left hemisphere anodal tDCS administered to temporal/frontal areas) under normal conditions or under conditions of cognitive (semantic) interference; b) identify parameters which may moderate the size of the tDCS effect within conventional stimulation protocols (e.g., online vs offline, high vs. low current densities, and short vs. long durations), as well as within types of stimulation not typically explored by previous reviews (i.e., right hemisphere anodal tDCS or left/right hemisphere cathodal tDCS). In all analyses there was no significant effect of tDCS, but we did find a small but significant effect of time and duration of stimulation with stronger effects for offline stimulation and for shorter durations (tDCS and its poor efficacy in healthy participants. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Grating stimulated echo

    International Nuclear Information System (INIS)

    Dubetsky, B.; Berman, P.R.; Sleator, T.

    1992-01-01

    A theory of a grating simulated echo (GTE) is developed. The GSE involves the sequential excitation of atoms by two counterpropagating traveling waves, a standing wave, and a third traveling wave. It is shown that the echo signal is very sensitive to small changes in atomic velocity, much more sensitive than the normal stimulated echo. Use of the GSE as a collisional probe or accelerometer is discussed

  6. Thyroid Stimulating Hormone Receptor

    Directory of Open Access Journals (Sweden)

    Murat Tuncel

    2017-02-01

    Full Text Available Thyroid stimulating hormone receptor (TSHR plays a pivotal role in thyroid hormone metabolism. It is a major controller of thyroid cell function and growth. Mutations in TSHR may lead to several thyroid diseases, most commonly hyperthyroidism. Although its genetic and epigenetic alterations do not directly lead to carcinogenesis, it has a crucial role in tumor growth, which is initiated by several oncogenes. This article will provide a brief review of TSHR and related diseases.

  7. Manual evaluation of residual curarization using double burst stimulation

    DEFF Research Database (Denmark)

    Drenck, N E; Ueda, N; Olsen, Niels Vidiendal

    1989-01-01

    Double burst stimulation (DBS) is a new mode of stimulation developed to reveal residual neuromuscular blockade under clinical conditions. The stimulus consists of two short bursts of 50 Hz tetanic stimulation, separated by 750 ms, and the response to the stimulation is two short muscle contracti......Double burst stimulation (DBS) is a new mode of stimulation developed to reveal residual neuromuscular blockade under clinical conditions. The stimulus consists of two short bursts of 50 Hz tetanic stimulation, separated by 750 ms, and the response to the stimulation is two short muscle...... contractions. Fade in the response results from neuromuscular blockade as with train-of-four stimulation (TOF). The authors compared the sensitivity of DBS and TOF in the detection of residual neuromuscular blockade during clinical anaesthesia. Fifty-two healthy patients undergoing surgery were studied...... with DBS than with TOF, regardless of the TOF ratio level. Absence of fade with TOF implied a 48% chance of considerable residual relaxation as compared with 9% when fade was absent with DBS. The results demonstrate that DBS is more sensitive than TOF in the manual detection of residual neuromuscular...

  8. Tumor significant dose

    International Nuclear Information System (INIS)

    Supe, S.J.; Nagalaxmi, K.V.; Meenakshi, L.

    1983-01-01

    In the practice of radiotherapy, various concepts like NSD, CRE, TDF, and BIR are being used to evaluate the biological effectiveness of the treatment schedules on the normal tissues. This has been accepted as the tolerance of the normal tissue is the limiting factor in the treatment of cancers. At present when various schedules are tried, attention is therefore paid to the biological damage of the normal tissues only and it is expected that the damage to the cancerous tissues would be extensive enough to control the cancer. Attempt is made in the present work to evaluate the concent of tumor significant dose (TSD) which will represent the damage to the cancerous tissue. Strandquist in the analysis of a large number of cases of squamous cell carcinoma found that for the 5 fraction/week treatment, the total dose required to bring about the same damage for the cancerous tissue is proportional to T/sup -0.22/, where T is the overall time over which the dose is delivered. Using this finding the TSD was defined as DxN/sup -p/xT/sup -q/, where D is the total dose, N the number of fractions, T the overall time p and q are the exponents to be suitably chosen. The values of p and q are adjusted such that p+q< or =0.24, and p varies from 0.0 to 0.24 and q varies from 0.0 to 0.22. Cases of cancer of cervix uteri treated between 1978 and 1980 in the V. N. Cancer Centre, Kuppuswamy Naidu Memorial Hospital, Coimbatore, India were analyzed on the basis of these formulations. These data, coupled with the clinical experience, were used for choice of a formula for the TSD. Further, the dose schedules used in the British Institute of Radiology fraction- ation studies were also used to propose that the tumor significant dose is represented by DxN/sup -0.18/xT/sup -0.06/

  9. Investigation of Balance Function Using Dynamic Posturography under Electrical-Acoustic Stimulation in Cochlear Implant Recipients

    Directory of Open Access Journals (Sweden)

    B. Schwab

    2010-01-01

    Full Text Available Introduction. The purpose of the present study is to investigate the effect of electrical-acoustic stimulation on vestibular function in CI patients by using the EquiTest and to help answer the question of whether electrically stimulating the inner ear using a cochlear implant influences the balance system in any way. Material and Methods. A test population (=50 was selected at random from among the cochlear implant recipients. Dynamic posturography (using the EquiTest was performed with the device switched off an switched on. Results. In summary, it can be said that an activated cochlear implant affects the function of the vestibular system and may, to an extent, even lead to a stabilization of balance function under the static conditions of dynamic posturography, but nevertheless also to a significant destabilization. Significant improvements in vestibular function were seen mainly in equilibrium scores under conditions 4 and 5, the composite equilibrium score, and the vestibular components as revealed by sensory analysis. Conclusions. Only under the static conditions are significantly poorer scores achieved when stimulation is applied. It may be that the explanation for any symptoms of dizziness lies precisely in the fact that they occur in supposedly noncritical situations, since, when the cochlear implant makes increased demands on the balance system, induced disturbances can be centrally suppressed.

  10. High frequency oscillations evoked by peripheral magnetic stimulation.

    Science.gov (United States)

    Biller, S; Simon, L; Fiedler, P; Strohmeier, D; Haueisen, J

    2011-01-01

    The analysis of somatosensory evoked potentials (SEP) and / or fields (SEF) is a well-established and important tool for investigating the functioning of the peripheral and central human nervous system. A standard technique to evoke SEPs / SEFs is the stimulation of the median nerve by using a bipolar electrical stimulus. We aim at an alternative stimulation technique enabling stimulation of deep nerve structures while reducing patient stress and error susceptibility. In the current study, we apply a commercial transcranial magnetic stimulation system for peripheral magnetic stimulation of the median nerve. We compare the results of simultaneously recorded EEG signals to prove applicability of our technique to evoke SEPs including low frequency components (LFC) as well as high frequency oscillations (HFO). Therefore, we compare amplitude, latency and time-frequency characteristics of the SEP of 14 healthy volunteers after electric and magnetic stimulation. Both low frequency components and high frequency oscillations were detected. The HFOs were superimposed onto the primary cortical response N20. Statistical analysis revealed significantly lower amplitudes and increased latencies for LFC and HFO components after magnetic stimulation. The differences indicate the inability of magnetic stimulation to elicit supramaximal responses. A psycho-perceptual evaluation showed that magnetic stimulation was less unpleasant for 12 out of the 14 volunteers. In conclusion, we showed that LFC and HFO components related to median nerve stimulation can be evoked by peripheral magnetic stimulation.

  11. Optimal number of stimulation contacts for coordinated reset neuromodulation

    Directory of Open Access Journals (Sweden)

    Borys eLysyansky

    2013-07-01

    Full Text Available In this computational study we investigatecoordinated reset (CR neuromodulation designed for an effective controlof synchronization by multi-site stimulation of neuronal target populations. This method was suggested to effectively counteract pathological neuronal synchronycharacteristic for several neurological disorders. We studyhow many stimulation sites are required for optimal CR-induced desynchronization. We found that a moderate increase of the number of stimulation sitesmay significantly prolong the post-stimulation desynchronized transientafter the stimulation is completely switched off. This can, in turn,reduce the amount of the administered stimulation current for theintermittent ON-OFF CR stimulation protocol, where time intervalswith stimulation ON are recurrently followed by time intervals withstimulation OFF. In addition, we found that the optimal number ofstimulation sites essentially depends on how strongly the administeredcurrent decays within the neuronal tissue with increasing distancefrom the stimulation site. In particular, for a broad spatial stimulationprofile, i.e., for a weak spatial decay rate of the stimulation current,CR stimulation can optimally be delivered via a small number of stimulationsites. Our findings may contribute to an optimization of therapeutic applications of CR neuromodulation.

  12. Uranium chemistry: significant advances

    International Nuclear Information System (INIS)

    Mazzanti, M.

    2011-01-01

    The author reviews recent progress in uranium chemistry achieved in CEA laboratories. Like its neighbors in the Mendeleev chart uranium undergoes hydrolysis, oxidation and disproportionation reactions which make the chemistry of these species in water highly complex. The study of the chemistry of uranium in an anhydrous medium has led to correlate the structural and electronic differences observed in the interaction of uranium(III) and the lanthanides(III) with nitrogen or sulfur molecules and the effectiveness of these molecules in An(III)/Ln(III) separation via liquid-liquid extraction. Recent work on the redox reactivity of trivalent uranium U(III) in an organic medium with molecules such as water or an azide ion (N 3 - ) in stoichiometric quantities, led to extremely interesting uranium aggregates particular those involved in actinide migration in the environment or in aggregation problems in the fuel processing cycle. Another significant advance was the discovery of a compound containing the uranyl ion with a degree of oxidation (V) UO 2 + , obtained by oxidation of uranium(III). Recently chemists have succeeded in blocking the disproportionation reaction of uranyl(V) and in stabilizing polymetallic complexes of uranyl(V), opening the way to to a systematic study of the reactivity and the electronic and magnetic properties of uranyl(V) compounds. (A.C.)

  13. Meaning and significance of

    Directory of Open Access Journals (Sweden)

    Ph D Student Roman Mihaela

    2011-05-01

    Full Text Available The concept of "public accountability" is a challenge for political science as a new concept in this area in full debate and developement ,both in theory and practice. This paper is a theoretical approach of displaying some definitions, relevant meanings and significance odf the concept in political science. The importance of this concept is that although originally it was used as a tool to improve effectiveness and eficiency of public governance, it has gradually become a purpose it itself. "Accountability" has become an image of good governance first in the United States of America then in the European Union.Nevertheless,the concept is vaguely defined and provides ambiguous images of good governance.This paper begins with the presentation of some general meanings of the concept as they emerge from specialized dictionaries and ancyclopaedies and continues with the meanings developed in political science. The concept of "public accontability" is rooted in economics and management literature,becoming increasingly relevant in today's political science both in theory and discourse as well as in practice in formulating and evaluating public policies. A first conclusin that emerges from, the analysis of the evolution of this term is that it requires a conceptual clarification in political science. A clear definition will then enable an appropriate model of proving the system of public accountability in formulating and assessing public policies, in order to implement a system of assessment and monitoring thereof.

  14. Evaluation of intradural stimulation efficiency and selectivity in a computational model of spinal cord stimulation.

    Directory of Open Access Journals (Sweden)

    Bryan Howell

    Full Text Available Spinal cord stimulation (SCS is an alternative or adjunct therapy to treat chronic pain, a prevalent and clinically challenging condition. Although SCS has substantial clinical success, the therapy is still prone to failures, including lead breakage, lead migration, and poor pain relief. The goal of this study was to develop a computational model of SCS and use the model to compare activation of neural elements during intradural and extradural electrode placement. We constructed five patient-specific models of SCS. Stimulation thresholds predicted by the model were compared to stimulation thresholds measured intraoperatively, and we used these models to quantify the efficiency and selectivity of intradural and extradural SCS. Intradural placement dramatically increased stimulation efficiency and reduced the power required to stimulate the dorsal columns by more than 90%. Intradural placement also increased selectivity, allowing activation of a greater proportion of dorsal column fibers before spread of activation to dorsal root fibers, as well as more selective activation of individual dermatomes at different lateral deviations from the midline. Further, the results suggest that current electrode designs used for extradural SCS are not optimal for intradural SCS, and a novel azimuthal tripolar design increased stimulation selectivity, even beyond that achieved with an intradural paddle array. Increased stimulation efficiency is expected to increase the battery life of implantable pulse generators, increase the recharge interval of rechargeable implantable pulse generators, and potentially reduce stimulator volume. The greater selectivity of intradural stimulation may improve the success rate of SCS by mitigating the sensitivity of pain relief to malpositioning of the electrode. The outcome of this effort is a better quantitative understanding of how intradural electrode placement can potentially increase the selectivity and efficiency of SCS

  15. Age-dependent effects of brain stimulation on network centrality.

    Science.gov (United States)

    Antonenko, Daria; Nierhaus, Till; Meinzer, Marcus; Prehn, Kristin; Thielscher, Axel; Ittermann, Bernd; Flöel, Agnes

    2018-04-18

    Functional magnetic resonance imaging (fMRI) studies have suggested that advanced age may mediate the effects of transcranial direct current stimulation (tDCS) on brain function. However, studies directly comparing neural tDCS effects between young and older adults are scarce and limited to task-related imaging paradigms. Resting-state (rs-) fMRI, that is independent of age-related differences in performance, is well suited to investigate age-associated differential neural tDCS effects. Three "online" tDCS conditions (anodal, cathodal, sham) were compared in a cross-over, within-subject design, in 30 young and 30 older adults. Active stimulation targeted the left sensorimotor network (active electrode over left sensorimotor cortex with right supraorbital reference electrode). A graph-based rs-fMRI data analysis approach (eigenvector centrality mapping) and complementary seed-based analyses characterized neural tDCS effects. An interaction between anodal tDCS and age group was observed. Specifically, centrality in bilateral paracentral and posterior regions (precuneus, superior parietal cortex) was increased in young, but decreased in older adults. Seed-based analyses revealed that these opposing patterns of tDCS-induced centrality modulation were explained from differential effects of tDCS on functional coupling of the stimulated left paracentral lobule. Cathodal tDCS did not show significant effects. Our study provides first evidence for differential tDCS effects on neural network organization in young and older adults. Anodal stimulation mainly affected coupling of sensorimotor with ventromedial prefrontal areas in young and decoupling with posteromedial areas in older adults. Copyright © 2018. Published by Elsevier Inc.

  16. Stimulants for the control of hedonic appetite

    Directory of Open Access Journals (Sweden)

    Alison Sally Poulton

    2016-04-01

    Full Text Available The focus of this paper is treatment of obesity in relation to the management of hedonic appetite. Obesity is a complex condition which may be potentiated by excessive reward seeking in combination with executive functioning deficits that impair cognitive control of behaviour. Stimulant medications address both reward deficiency and enhance motivation, as well as suppressing appetite. They have long been recognised to be effective for treating obesity. However, stimulants can be abused for their euphoric effect. They induce euphoria via the same neural pathway that underlies their therapeutic effect in obesity. For this reason they have generally not been endorsed for use in obesity. Among the stimulants, only phentermine (either alone or in combination with topiramate and bupropion (which has stimulant-like properties and is used in combination with naltrexone, are approved by the United States Food and Drug Administration (FDA for obesity, although dexamphetamine and methylpenidate are approved and widely used for treating attention deficit hyperactivity disorder (ADHD in adults and children. Experience gained over many years in the treatment of ADHD demonstrates that with careful dose titration, stimulants can be used safely. In obesity, improvement in mood and executive functioning could assist with the lifestyle changes necessary for weight control, acting synergistically with appetite suppression. The obesity crisis has reached the stage that strong consideration should be given to adequate utilisation of this effective and inexpensive class of drug.

  17. Technological Advances in Deep Brain Stimulation.

    Science.gov (United States)

    Ughratdar, Ismail; Samuel, Michael; Ashkan, Keyoumars

    2015-01-01

    Functional and stereotactic neurosurgery has always been regarded as a subspecialty based on and driven by technological advances. However until recently, the fundamentals of deep brain stimulation (DBS) hardware and software design had largely remained stagnant since its inception almost three decades ago. Recent improved understanding of disease processes in movement disorders as well clinician and patient demands has resulted in new avenues of development for DBS technology. This review describes new advances both related to hardware and software for neuromodulation. New electrode designs with segmented contacts now enable sophisticated shaping and sculpting of the field of stimulation, potentially allowing multi-target stimulation and avoidance of side effects. To avoid lengthy programming sessions utilising multiple lead contacts, new user-friendly software allows for computational modelling and individualised directed programming. Therapy delivery is being improved with the next generation of smaller profile, longer-lasting, re-chargeable implantable pulse generators (IPGs). These include IPGs capable of delivering constant current stimulation or personalised closed-loop adaptive stimulation. Post-implantation Magnetic Resonance Imaging (MRI) has long been an issue which has been partially overcome with 'MRI conditional devices' and has enabled verification of DBS lead location. Surgical technique is considering a shift from frame-based to frameless stereotaxy or greater role for robot assisted implantation. The challenge for these contemporary techniques however, will be in demonstrating equivalent safety and accuracy to conventional methods. We also discuss potential future direction utilising wireless technology allowing for miniaturisation of hardware.

  18. Significant Radionuclides Determination

    Energy Technology Data Exchange (ETDEWEB)

    Jo A. Ziegler

    2001-07-31

    The purpose of this calculation is to identify radionuclides that are significant to offsite doses from potential preclosure events for spent nuclear fuel (SNF) and high-level radioactive waste expected to be received at the potential Monitored Geologic Repository (MGR). In this calculation, high-level radioactive waste is included in references to DOE SNF. A previous document, ''DOE SNF DBE Offsite Dose Calculations'' (CRWMS M&O 1999b), calculated the source terms and offsite doses for Department of Energy (DOE) and Naval SNF for use in design basis event analyses. This calculation reproduces only DOE SNF work (i.e., no naval SNF work is included in this calculation) created in ''DOE SNF DBE Offsite Dose Calculations'' and expands the calculation to include DOE SNF expected to produce a high dose consequence (even though the quantity of the SNF is expected to be small) and SNF owned by commercial nuclear power producers. The calculation does not address any specific off-normal/DBE event scenarios for receiving, handling, or packaging of SNF. The results of this calculation are developed for comparative analysis to establish the important radionuclides and do not represent the final source terms to be used for license application. This calculation will be used as input to preclosure safety analyses and is performed in accordance with procedure AP-3.12Q, ''Calculations'', and is subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (DOE 2000) as determined by the activity evaluation contained in ''Technical Work Plan for: Preclosure Safety Analysis, TWP-MGR-SE-000010'' (CRWMS M&O 2000b) in accordance with procedure AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities''.

  19. Evaluation of aldosterone-and cortisol levels in blood plasma in normal conditions of ingestion of sodium and potassium, after saline-increase and depletion, in regard to position, and after stimulation with ACTH and angiotensin II

    International Nuclear Information System (INIS)

    Okada, H.

    1979-01-01

    Methods for the determination of plasma aldosterone and cortisol, by radioimmunoassay, were performed utilizing highly specific antisera. With this methodology it was possible to evaluate cortisol and aldosterone secretion, in six normal subjects, submitted to a basal rice diet on standing and recumbent positions, the effects of exogenous cortrosyn (β1-24 ACTH) and angiotensin II and the same manoevres with progressively increased Na + content of the diet. Aldosterone basal levels decreased with the increase of Na + content in the diet. However, there were no significant differences between the relative increments observed on the recumbent position, at the three levels of sodium intake. The relative increase of plasma aldosterone after ACTH was similar for each basal level of aldosterone induced by different sodium intakes. The responsiveness of aldosterone secretion to cortrosyn and standing position was similar, with no relation to the sodium intake. The infusion of angiotensin II induced an increase in plasma aldosterone, and the relative increment in the levels of the hormone were higher with high sodium than on the rice diet. The average basal cortisol value at the different levels of sodium intake was significantly different being greater on the basal, rice diet, and there was a decrease in cortisol level after recumbency, with the theree diets. The injection of ACTH induced similar cortisol secretion with no relation to the sodium intake. The infusion of non-hypertensive doses of angiotensin II resulted in an anomalous fall in cortisol level, probably because of 'shunt' of substrates to biosynthesis with the added effect of cortisol diurnal rhythmycity. (Author) [pt

  20. Mechanically stimulated bone cells secrete paracrine factors that regulate osteoprogenitor recruitment, proliferation, and differentiation

    International Nuclear Information System (INIS)

    Brady, Robert T.; O'Brien, Fergal J.; Hoey, David A.

    2015-01-01

    Bone formation requires the recruitment, proliferation and osteogenic differentiation of mesenchymal progenitors. A potent stimulus driving this process is mechanical loading, yet the signalling mechanisms underpinning this are incompletely understood. The objective of this study was to investigate the role of the mechanically-stimulated osteocyte and osteoblast secretome in coordinating progenitor contributions to bone formation. Initially osteocytes (MLO-Y4) and osteoblasts (MC3T3) were mechanically stimulated for 24hrs and secreted factors within the conditioned media were collected and used to evaluate mesenchymal stem cell (MSC) and osteoblast recruitment, proliferation and osteogenesis. Paracrine factors secreted by mechanically stimulated osteocytes significantly enhanced MSC migration, proliferation and osteogenesis and furthermore significantly increased osteoblast migration and proliferation when compared to factors secreted by statically cultured osteocytes. Secondly, paracrine factors secreted by mechanically stimulated osteoblasts significantly enhanced MSC migration but surprisingly, in contrast to the osteocyte secretome, inhibited MSC proliferation when compared to factors secreted by statically cultured osteoblasts. A similar trend was observed in osteoblasts. This study provides new information on mechanically driven signalling mechanisms in bone and highlights a contrasting secretome between cells at different stages in the bone lineage, furthering our understanding of loading-induced bone formation and indirect biophysical regulation of osteoprogenitors. - Highlights: • Physically stimulated osteocytes secrete factors that regulate osteoprogenitors. • These factors enhance recruitment, proliferation and osteogenic differentiation. • Physically stimulated osteoblasts secrete factors that also regulate progenitors. • These factors enhance recruitment but inhibit proliferation of osteoprogenitors. • This study highlights a contrasting

  1. Mechanically stimulated bone cells secrete paracrine factors that regulate osteoprogenitor recruitment, proliferation, and differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Brady, Robert T. [Tissue Engineering Research Group, Dept. of Anatomy, Royal College of Surgeons in Ireland (Ireland); Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin (Ireland); Advanced Materials and BioEngineering Research Centre (AMBER), Trinity College Dublin & Royal College of Surgeons in Ireland (Ireland); Dept. of Mechanical, Aeronautical and Biomedical Engineering, University of Limerick (Ireland); O' Brien, Fergal J. [Tissue Engineering Research Group, Dept. of Anatomy, Royal College of Surgeons in Ireland (Ireland); Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin (Ireland); Advanced Materials and BioEngineering Research Centre (AMBER), Trinity College Dublin & Royal College of Surgeons in Ireland (Ireland); Hoey, David A., E-mail: david.hoey@ul.ie [Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin (Ireland); Dept. of Mechanical, Aeronautical and Biomedical Engineering, University of Limerick (Ireland); The Centre for Applied Biomedical Engineering Research, University of Limerick (Ireland); Materials & Surface Science Institute, University of Limerick (Ireland)

    2015-03-27

    Bone formation requires the recruitment, proliferation and osteogenic differentiation of mesenchymal progenitors. A potent stimulus driving this process is mechanical loading, yet the signalling mechanisms underpinning this are incompletely understood. The objective of this study was to investigate the role of the mechanically-stimulated osteocyte and osteoblast secretome in coordinating progenitor contributions to bone formation. Initially osteocytes (MLO-Y4) and osteoblasts (MC3T3) were mechanically stimulated for 24hrs and secreted factors within the conditioned media were collected and used to evaluate mesenchymal stem cell (MSC) and osteoblast recruitment, proliferation and osteogenesis. Paracrine factors secreted by mechanically stimulated osteocytes significantly enhanced MSC migration, proliferation and osteogenesis and furthermore significantly increased osteoblast migration and proliferation when compared to factors secreted by statically cultured osteocytes. Secondly, paracrine factors secreted by mechanically stimulated osteoblasts significantly enhanced MSC migration but surprisingly, in contrast to the osteocyte secretome, inhibited MSC proliferation when compared to factors secreted by statically cultured osteoblasts. A similar trend was observed in osteoblasts. This study provides new information on mechanically driven signalling mechanisms in bone and highlights a contrasting secretome between cells at different stages in the bone lineage, furthering our understanding of loading-induced bone formation and indirect biophysical regulation of osteoprogenitors. - Highlights: • Physically stimulated osteocytes secrete factors that regulate osteoprogenitors. • These factors enhance recruitment, proliferation and osteogenic differentiation. • Physically stimulated osteoblasts secrete factors that also regulate progenitors. • These factors enhance recruitment but inhibit proliferation of osteoprogenitors. • This study highlights a contrasting

  2. Low intensity transcranial electric stimulation

    DEFF Research Database (Denmark)

    Antal, Andrea; Alekseichuk, I; Bikson, M

    2017-01-01

    Low intensity transcranial electrical stimulation (TES) in humans, encompassing transcranial direct current (tDCS), transcutaneous spinal Direct Current Stimulation (tsDCS), transcranial alternating current (tACS), and transcranial random noise (tRNS) stimulation or their combinations, appears...

  3. Culture Conditions stimulating high γ-Linolenic Acid accumulation by Spirulina platensis Condições de cultura simulando o levado acúmulo de ácido γ-linolênico por Spirulina platensis

    Directory of Open Access Journals (Sweden)

    Srinivasa Reddy Ronda

    2008-12-01

    Full Text Available Gamma-linolenic acid (GLA production by Spirulina platensis under different stress-inducing conditions was studied. Submerged culture studies showed that low temperature (25ºC, strong light intensity (6 klux and primrose oil supplement (0.8%w/v induced 13.2 mg/g, 14.6 mg/g and 13.5 mg linolenic acid per gram dry cell weight respectively. A careful observation of fatty acid profile of the cyanobacteria shows that, oleic acid and linoleic acid, in experiments with varying growth temperature and oil supplements respectively, helped in accumulating excess γ-linolenic acid. In addition, cultures grown at increasing light regimes maintained the γ-linolenic acid to the total fatty acid ratio(GLA/TFA constant, despite any change in γ-linolenic acid content of the cyanobacteria.Estudou-se a produção de ácido γ-linolênico por Spirulina platensis em diferentes condições de estresse. Culturas submersas indicaram que temperatura baixa (25ºC, forte intensidade de luz (6 klux e suplementação com óleo de prímula (0,8% p/v induziram a produção de ácido linolênico de 13,2 mg/g, 14,6 mg/g e 13,5 mg/g peso seco, respectivamente. Uma observação cuidadosa do perfil de ácidos graxos da cianobacteria indica que os ácidos oléico e linoléico, em experimentos com diferentes temperaturas de crescimento e suplementos de óleo, auxiliaram no acúmulo de excesso de ácido γ-linolênico. Além disso, as culturas obtidas em intensidades crescentes de luz mantiveram a relação ácido γ-linolênico/ácidos graxos totais constante, independentemente de qualquer mudança no conteúdo de ácido γ-linolênico da cianobactéria.

  4. Neural Stimulation Has a Long-Term Effect on Foreign Vocabulary Acquisition.

    Science.gov (United States)

    Pasqualotto, Achille; Kobanbay, Begüm; Proulx, Michael J

    2015-01-01

    Acquisition of a foreign language is a challenging task that is becoming increasingly more important in the world nowadays. There is evidence suggesting that the frontal and temporal cortices are involved in language processing and comprehension, but it is still unknown whether foreign language acquisition recruits additional cortical areas in a causal manner. For the first time, we used transcranial random noise stimulation on the frontal and parietal brain areas, in order to compare its effect on the acquisition of unknown foreign words and a sham, or placebo, condition was also included. This type of noninvasive neural stimulation enhances cortical activity by boosting the spontaneous activity of neurons. Foreign vocabulary acquisition was tested both immediately and seven days after the stimulation. We found that stimulation on the posterior parietal, but not the dorsolateral prefrontal cortex or sham stimulation, significantly improved the memory performance in the long term. These results suggest that the posterior parietal cortex is directly involved in acquisition of foreign vocabulary, thus extending the "linguistic network" to this area.

  5. Reduced multimodal integration of memory features following continuous theta burst stimulation of angular gyrus.

    Science.gov (United States)

    Yazar, Yasemin; Bergström, Zara M; Simons, Jon S

    Lesions of the angular gyrus (AnG) region of human parietal cortex do not cause amnesia, but appear to be associated with reduction in the ability to consciously experience the reliving of previous events. We used continuous theta burst stimulation to test the hypothesis that the cognitive mechanism implicated in this memory deficit might be the integration of retrieved sensory event features into a coherent multimodal memory representation. Healthy volunteers received stimulation to AnG or a vertex control site after studying stimuli that each comprised a visual object embedded in a scene, with the name of the object presented auditorily. Participants were then asked to make memory judgments about the studied stimuli that involved recollection of single event features (visual or auditory), or required integration of event features within the same modality, or across modalities. Participants' ability to retrieve context features from across multiple modalities was significantly reduced after AnG stimulation compared to stimulation of the vertex. This effect was observed only for the integration of cross-modal context features but not for integration of features within the same modality, and could not be accounted for by task difficulty as performance was matched across integration conditions following vertex stimulation. These results support the hypothesis that AnG is necessary for the multimodal integration of distributed cortical episodic features into a unified conscious representation that enables the experience of remembering. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  6. What if there were no significance tests?

    CERN Document Server

    Harlow, Lisa L; Steiger, James H

    2013-01-01

    This book is the result of a spirited debate stimulated by a recent meeting of the Society of Multivariate Experimental Psychology. Although the viewpoints span a range of perspectives, the overriding theme that emerges states that significance testing may still be useful if supplemented with some or all of the following -- Bayesian logic, caution, confidence intervals, effect sizes and power, other goodness of approximation measures, replication and meta-analysis, sound reasoning, and theory appraisal and corroboration. The book is organized into five general areas. The first presents an overview of significance testing issues that sythesizes the highlights of the remainder of the book. The next discusses the debate in which significance testing should be rejected or retained. The third outlines various methods that may supplement current significance testing procedures. The fourth discusses Bayesian approaches and methods and the use of confidence intervals versus significance tests. The last presents the p...

  7. Comparisons among serum, egg albumin and yolk concentrations of corticosterone as biomarkers of basal and stimulated adrenocortical activity of laying hens.

    Science.gov (United States)

    Cook, N J; Renema, R; Wilkinson, C; Schaefer, A L

    2009-09-01

    1. Serial blood samples from individual birds were analysed for corticosterone concentrations under basal and stimulated conditions, and matched to eggs from the same birds for comparison to albumin and yolk concentrations of corticosterone. 2. Serum corticosterone exhibited increases in response to stimulation by ACTH and Handling stress. There were no significant increases in egg albumin or yolk concentrations of corticosterone following stimulation. 3. Several significant correlations were observed between the mean and area under the curve (AUC) measurements of serum corticosterone concentrations with albumin and yolk corticosterone concentrations in eggs laid from 1 to 2 d later. 4. The results demonstrated a relationship between endogenous concentrations of serum corticosterone that reflected daily adrenocortical output with albumin and yolk corticosterone concentrations in eggs laid the following day. 5. The results do not support the concept of albumin and yolk concentrations of corticosterone as biomarkers of acute adrenocortical responses to stimulation.

  8. Online effects of transcranial direct current stimulation on prefrontal metabolites in gambling disorder.

    Science.gov (United States)

    Dickler, Maya; Lenglos, Christophe; Renauld, Emmanuelle; Ferland, Francine; Edden, Richard A; Leblond, Jean; Fecteau, Shirley

    2018-03-15

    Gambling disorder is characterized by persistent maladaptive gambling behaviors and is now considered among substance-related and addictive disorders. There is still unmet therapeutic need for these clinical populations, however recent advances indicate that interventions targeting the Glutamatergic/GABAergic system hold promise in reducing symptoms in substance-related and addictive disorders, including gambling disorder. There is some data indicating that transcranial direct current stimulation may hold clinical benefits in substance use disorders and modulate levels of brain metabolites including glutamate and GABA. The goal of the present work was to test whether this non-invasive neurostimulation method modulates key metabolites in gambling disorder. We conducted a sham-controlled, crossover, randomized study, blinded at two levels in order to characterize the effects of transcranial direct current stimulation over the dorsolateral prefrontal cortex on neural metabolites levels in sixteen patients with gambling disorder. Metabolite levels were measured with magnetic resonance spectroscopy from the right dorsolateral prefrontal cortex and the right striatum during active and sham stimulation. Active as compared to sham stimulation elevated prefrontal GABA levels. There were no significant changes between stimulation conditions in prefrontal glutamate + glutamine and N-acetyl Aspartate, or in striatal metabolite levels. Results also indicated positive correlations between metabolite levels during active, but not sham, stimulation and levels of risk taking, impulsivity and craving. Our findings suggest that transcranial direct current stimulation can modulate GABA levels in patients with gambling disorder which may represent an interesting future therapeutic avenue. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Preliminary evidence for performance enhancement following parietal lobe stimulation in Developmental Dyscalculia.

    Science.gov (United States)

    Iuculano, Teresa; Cohen Kadosh, Roi

    2014-01-01

    Nearly 7% of the population exhibit difficulties in dealing with numbers and performing arithmetic, a condition named Developmental Dyscalculia (DD), which significantly affects the educational and professional outcomes of these individuals, as it often persists into adulthood. Research has mainly focused on behavioral rehabilitation, while little is known about performance changes and neuroplasticity induced by the concurrent application of brain-behavioral approaches. It has been shown that numerical proficiency can be enhanced by applying a small-yet constant-current through the brain, a non-invasive technique named transcranial electrical stimulation (tES). Here we combined a numerical learning paradigm with transcranial direct current stimulation (tDCS) in two adults with DD to assess the potential benefits of this methodology to remediate their numerical difficulties. Subjects learned to associate artificial symbols to numerical quantities within the context of a trial and error paradigm, while tDCS was applied to the posterior parietal cortex (PPC). The first subject (DD1) received anodal stimulation to the right PPC and cathodal stimulation to the left PPC, which has been associated with numerical performance's improvements in healthy subjects. The second subject (DD2) received anodal stimulation to the left PPC and cathodal stimulation to the right PPC, which has been shown to impair numerical performance in healthy subjects. We examined two indices of numerical proficiency: (i) automaticity of number processing; and (ii) mapping of numbers onto space. Our results are opposite to previous findings with non-dyscalculic subjects. Only anodal stimulation to the left PPC improved both indices of numerical proficiency. These initial results represent an important step to inform the rehabilitation of developmental learning disabilities, and have relevant applications for basic and applied research in cognitive neuroscience, rehabilitation, and education.

  10. Preliminary evidence for performance enhancement following parietal lobe stimulation in Developmental Dyscalculia

    Directory of Open Access Journals (Sweden)

    Teresa eIuculano

    2014-02-01

    Full Text Available Nearly 7% of the population exhibit difficulties in dealing with numbers and performing arithmetic, a condition named Developmental Dyscalculia (DD, which significantly affects the educational and professional outcomes of these individuals, as it often persists into adulthood. Research has mainly focused on behavioral rehabilitation, while little is known about performance changes and neuroplasticity induced by the concurrent application of brain-behavioral approaches. It has been shown that numerical proficiency can be enhanced by applying a small – yet constant – current through the brain, a non-invasive technique named transcranial electrical stimulation (tES. Here we combined a numerical learning paradigm with transcranial direct current stimulation (tDCS in two adults with DD to assess the potential benefits of this methodology to remediate their numerical difficulties. Subjects learned to associate artificial symbols to numerical quantities within the context of a trial and error paradigm, while tDCS was applied to the posterior parietal cortex (PPC. The first subject (DD1 received anodal stimulation to the right PPC and cathodal stimulation to the left PPC, which has been associated with numerical performance’s improvements in healthy subjects. The second subject (DD2 received anodal stimulation to the left PPC and cathodal stimulation to the right PPC, which has been shown to impair numerical performance in healthy subjects. We examined two indices of numerical proficiency: (i automaticity of number processing; and (ii mapping of numbers onto space. Our results are opposite to previous findings with non-dyscalculic subjects. Only anodal stimulation to the left PPC improved both indices of numerical proficiency. These initial results represent an important step to inform the rehabilitation of developmental learning disabilities, and have relevant applications for basic and applied research in cognitive neuroscience, rehabilitation

  11. Time and frequency-dependent modulation of local field potential synchronization by deep brain stimulation.

    Directory of Open Access Journals (Sweden)

    Clinton B McCracken

    Full Text Available High-frequency electrical stimulation of specific brain structures, known as deep brain stimulation (DBS, is an effective treatment for movement disorders, but mechanisms of action remain unclear. We examined the time-dependent effects of DBS applied to the entopeduncular nucleus (EP, the rat homolog of the internal globus pallidus, a target used for treatment of both dystonia and Parkinson's disease (PD. We performed simultaneous multi-site local field potential (LFP recordings in urethane-anesthetized rats to assess the effects of high-frequency (HF, 130 Hz; clinically effective, low-frequency (LF, 15 Hz; ineffective and sham DBS delivered to EP. LFP activity was recorded from dorsal striatum (STR, ventroanterior thalamus (VA, primary motor cortex (M1, and the stimulation site in EP. Spontaneous and acute stimulation-induced LFP oscillation power and functional connectivity were assessed at baseline, and after 30, 60, and 90 minutes of stimulation. HF EP DBS produced widespread alterations in spontaneous and stimulus-induced LFP oscillations, with some effects similar across regions and others occurring in a region- and frequency band-specific manner. Many of these changes evolved over time. HF EP DBS produced an initial transient reduction in power in the low beta band in M1 and STR; however, phase synchronization between these regions in the low beta band was markedly suppressed at all time points. DBS also enhanced low gamma synchronization throughout the circuit. With sustained stimulation, there were significant reductions in low beta synchronization between M1-VA and STR-VA, and increases in power within regions in the faster frequency bands. HF DBS also suppressed the ability of acute EP stimulation to induce beta oscillations in all regions along the circuit. This dynamic pattern of synchronizing and desynchronizing effects of EP DBS suggests a complex modulation of activity along cortico-BG-thalamic circuits underlying the therapeutic

  12. A novel dual-wavelength laser stimulator to elicit transient and tonic nociceptive stimulation.

    Science.gov (United States)

    Dong, Xiaoxi; Liu, Tianjun; Wang, Han; Yang, Jichun; Chen, Zhuying; Hu, Yong; Li, Yingxin

    2017-07-01

    This study aimed to develop a new laser stimulator to elicit both transient and sustained heat stimulation with a dual-wavelength laser system as a tool for the investigation of both transient and tonic experimental models of pain. The laser stimulator used a 980-nm pulsed laser to generate transient heat stimulation and a 1940-nm continuous-wave (CW) laser to provide sustained heat stimulation. The laser with 980-nm wavelength can elicit transient pain with less thermal injury, while the 1940-nm CW laser can effectively stimulate both superficial and deep nociceptors to elicit tonic pain. A proportional integral-derivative (PID) temperature feedback control system was implemented to ensure constancy of temperature during heat stimulation. The performance of this stimulator was evaluated by in vitro and in vivo animal experiments. In vitro experiments on totally 120 specimens fresh pig skin included transient heat stimulation by 980-nm laser (1.5 J, 10 ms), sustained heat stimulation by 1940-nm laser (50-55 °C temperature control mode or 1.5 W, 5 min continuous power supply), and the combination of transient/sustained heat stimulation by dual lasers (1.5 J, 10 ms, 980-nm pulse laser, and 1940-nm laser with 50-55 °C temperature control mode). Hemoglobin brushing and wind-cooling methods were tested to find better stimulation model. A classic tail-flick latency (TFL) experiment with 20 Wistar rats was used to evaluate the in vivo efficacy of transient and tonic pain stimulation with 15 J, 100 ms 980-nm single laser pulse, and 1.5 W constant 1940-nm laser power. Ideal stimulation parameters to generate transient pain were found to be a 26.6 °C peak temperature rise and 0.67 s pain duration. In our model of tonic pain, 5 min of tonic stimulation produced a temperature change of 53.7 ± 1.3 °C with 1.6 ± 0.2% variation. When the transient and tonic stimulation protocols were combined, no significant difference was observed depending on the order

  13. Blockade of NMDA receptors blocks the acquisition of cocaine conditioned approach in rats.

    Science.gov (United States)

    Galaj, Ewa; Seepersad, Neal; Dakmak, Zena; Ranaldi, Robert

    2018-01-05

    Conditioned stimuli (CSs) exert motivational effects on both adaptive and pathological reward-related behaviors, including drug taking and seeking. We developed a paradigm that allows us to investigate the neuropharmacology by which previously neutral stimuli acquire the capacity to function as CSs and elicit (intravenous) cocaine conditioned approach and used this paradigm to test the role of NMDA receptor stimulation in the acquisition of cocaine conditioned approach. Rats were injected systemically with the NMDA receptor antagonist, MK-801, before the start of 4 consecutive conditioning sessions, each of which consisted of 20 randomly presented light/tone (CS) presentations paired with cocaine infusion contingent upon nose pokes. Rats later were subjected to a CS-only test. To test the role of NMDA receptor stimulation in the already established conditioned approach, rats were injected with MK-801 prior to the CS-only test that occurred after 18 CS-cocaine conditioning sessions. Blockade of NMDA receptors significantly impaired the acquisition of cocaine-conditioned approach as indicated by the emission of significantly fewer nose pokes and significantly longer latencies to nose poke during CS presentations. When MK-801 treatment was applied after the acquisition of conditioned approach responding it had no effect on these measures. These results suggest that NMDA receptor stimulation plays an important role in the acquisition of reward-related conditioned responses driven by intravenous cocaine-associated CSs. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Low dose stimulation in foeniculum vulgare

    International Nuclear Information System (INIS)

    Jahagirdar, H.A.; Khalatkar, A.W.; Dnyansagar, V.R.

    1974-01-01

    Genetically pure seeds with a moisture content of 12.5% were irradiated in a 60 Co γ-source at a dose rate of 1.1 KR/min, the radiation dose varying between 2 and 14 KR. Four days after irradiation the seeds were sown into the open field. Stimulation was determined on the basis of a lot of parameters e.g. height. The results indicated a significant stimulation after 10 KR as far as seed yield is concerned. (MG) [de

  15. Parametric changes in response equilibrium during an intra-cranial self stimulation (ICSS) task: can reward value be assessed independently of absolute threshold?

    Science.gov (United States)

    Easterling, K W; Holtzman, S G

    1997-01-01

    Traditional ICSS methodologies have attempted to evaluate changes in the rewarding value of brain stimulation by assessing the lowest value of the stimulation that will support responding. However, orderly changes in suprathreshold indicants of hedonic magnitude such as titration point have been shown. In the present experiments, rats were trained to respond on two ICSS autotitration schedules in which every response on one lever produced stimulation of the medial forebrain bundle, and every Xth response decreased either the stimulation current or the stimulation frequency. At any time, a response on a second "reset" lever restored the stimulation current or frequency available on the stimulation lever to its starting level and operationally defined changes in "reward value". In order to study this titration point measure, two response requirements (responses/stepdown; step size) and two stimulation parameters (initial stimulation level; train duration) were systematically varied. Under both current and frequency titration schedules, data indicated that response rate and titration point remained stable over repeated trials and multiple testing days--parameters being constant. Across all conditions, compared to the frequency titration schedule, subjects responding under the current titration schedule showed significantly higher titration points and lower rates of responding. Indicating the independence of rate and titration point data, parametric manipulations did not affect titration point and rate data concurrently. Results support the conclusion that titration point is a relative measure of "reward value" that is generally independent of response rate, but that is affected by manipulations that alter the amount of stimulation available between "resets". Additional work is needed in order to determine the relationship between the magnitude of stimulation needed to maintain minimal responding and that needed to maintain response equilibrium in an autotitration task.

  16. Vertical illusory self-motion through haptic stimulation of the feet

    DEFF Research Database (Denmark)

    Nordahl, Rolf; Nilsson, Niels Christian; Turchet, Luca

    2012-01-01

    Circular and linear self-motion illusions induced through visual and auditory stimuli have been studied rather extensively. While the ability of haptic stimuli to augment such illusions has been investigated, the self-motion illusions which primarily are induced by stimulation of the haptic...... to generate the haptic feedback while the final condition included no haptic feedback. Analysis of self-reports were used to assess the participants' experience of illusory self-motion. The results indicate that such illusions are indeed possible. Significant differences were found between the condition...... modality remain relatively unexplored. In this paper, we present an experiment performed with the intention of investigating whether it is possible to use haptic stimulation of the main supporting areas of the feet to induce vertical illusory self-motion on behalf of unrestrained participants during...

  17. Higher success rate with transcranial electrical stimulation of motor-evoked potentials using constant-voltage stimulation compared with constant-current stimulation in patients undergoing spinal surgery.

    Science.gov (United States)

    Shigematsu, Hideki; Kawaguchi, Masahiko; Hayashi, Hironobu; Takatani, Tsunenori; Iwata, Eiichiro; Tanaka, Masato; Okuda, Akinori; Morimoto, Yasuhiko; Masuda, Keisuke; Tanaka, Yuu; Tanaka, Yasuhito

    2017-10-01

    During spine surgery, the spinal cord is electrophysiologically monitored via transcranial electrical stimulation of motor-evoked potentials (TES-MEPs) to prevent injury. Transcranial electrical stimulation of motor-evoked potential involves the use of either constant-current or constant-voltage stimulation; however, there are few comparative data available regarding their ability to adequately elicit compound motor action potentials. We hypothesized that the success rates of TES-MEP recordings would be similar between constant-current and constant-voltage stimulations in patients undergoing spine surgery. The objective of this study was to compare the success rates of TES-MEP recordings between constant-current and constant-voltage stimulation. This is a prospective, within-subject study. Data from 100 patients undergoing spinal surgery at the cervical, thoracic, or lumbar level were analyzed. The success rates of the TES-MEP recordings from each muscle were examined. Transcranial electrical stimulation with constant-current and constant-voltage stimulations at the C3 and C4 electrode positions (international "10-20" system) was applied to each patient. Compound muscle action potentials were bilaterally recorded from the abductor pollicis brevis (APB), deltoid (Del), abductor hallucis (AH), tibialis anterior (TA), gastrocnemius (GC), and quadriceps (Quad) muscles. The success rates of the TES-MEP recordings from the right Del, right APB, bilateral Quad, right TA, right GC, and bilateral AH muscles were significantly higher using constant-voltage stimulation than those using constant-current stimulation. The overall success rates with constant-voltage and constant-current stimulations were 86.3% and 68.8%, respectively (risk ratio 1.25 [95% confidence interval: 1.20-1.31]). The success rates of TES-MEP recordings were higher using constant-voltage stimulation compared with constant-current stimulation in patients undergoing spinal surgery. Copyright © 2017

  18. A novel approach to mechanical foot stimulation during human locomotion under body weight support.

    Science.gov (United States)

    Gravano, S; Ivanenko, Y P; Maccioni, G; Macellari, V; Poppele, R E; Lacquaniti, F

    2011-04-01

    Input from the foot plays an essential part in perceiving support surfaces and determining kinematic events in human walking. To simulate adequate tactile pressure inputs under body weight support (BWS) conditions that represent an effective form of locomotion training, we here developed a new method of phasic mechanical foot stimulation using light-weight pneumatic insoles placed inside the shoes (under the heel and metatarsus). To test the system, we asked healthy participants to walk on a treadmill with different levels of BWS. The pressure under the stimulated areas of the feet and subjective sensations were higher at high levels of BWS and when applied to the ball and toes rather than heels. Foot stimulation did not disturb significantly the normal motor pattern, and in all participants we evoked a reliable step-synchronized triggering of stimuli for each leg separately. This approach has been performed in a general framework looking for "afferent templates" of human locomotion that could be used for functional sensory stimulation. The proposed technique can be used to imitate or partially restore surrogate contact forces under body weight support conditions. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. Palatoglossus coupling in selective upper airway stimulation.

    Science.gov (United States)

    Heiser, Clemens; Edenharter, Günther; Bas, Murat; Wirth, Markus; Hofauer, Benedikt

    2017-10-01

    Selective upper airway stimulation (sUAS) of the hypoglossal nerve is a useful therapy to treat patients with obstructive sleep apnea. Is it known that multiple obstructions can be solved by this stimulation technique, even at the retropalatal region. The aim of this study was to verify the palatoglossus coupling at the soft palate during stimulation. Single-center, prospective clinical trail. Twenty patients who received an sUAS implant from April 2015 to April 2016 were included. A drug-induced sedated endoscopy (DISE) was performed before surgery. Six to 12 months after activation of the system, patients' tongue motions were recorded, an awake transnasal endoscopy was performed with stimulation turned on, and a DISE with stimulation off and on was done. Patients with a bilateral protrusion of the tongue base showed a significantly increased opening at the retropalatal level compared to ipsilateral protrusions. Furthermore, patients with a clear activation of the geniohyoid muscle showed a better reduction in apnea-hypopnea index. A bilateral protrusion of the tongue base during sUAS seems to be accompanied with a better opening of the soft palate. This effect can be explained by the palatoglossal coupling, due to its linkage of the muscles within the soft palate to those of the lateral tongue body. 4 Laryngoscope, 127:E378-E383, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  20. Spinal cord stimulation for neuropathic pain: current perspectives.

    Science.gov (United States)

    Wolter, Tilman

    2014-01-01

    Neuropathic pain constitutes a significant portion of chronic pain. Patients with neuropathic pain are usually more heavily burdened than patients with nociceptive pain. They suffer more often from insomnia, anxiety, and depression. Moreover, analgesic medication often has an insufficient effect on neuropathic pain. Spinal cord stimulation constitutes a therapy alternative that, to date, remains underused. In the last 10 to 15 years, it has undergone constant technical advancement. This review gives an overview of the present practice of spinal cord stimulation for chronic neuropathic pain and current developments such as high-frequency stimulation and peripheral nerve field stimulation.

  1. Inner Retinal Oxygen Extraction Fraction in Response to Light Flicker Stimulation in Humans

    Science.gov (United States)

    Felder, Anthony E.; Wanek, Justin; Blair, Norman P.; Shahidi, Mahnaz

    2015-01-01

    Purpose Light flicker has been shown to stimulate retinal neural activity, increase blood flow, and alter inner retinal oxygen metabolism (MO2) and delivery (DO2). The purpose of the study was to determine the change in MO2 relative to DO2 due to light flicker stimulation in humans, as assessed by the inner retinal oxygen extraction fraction (OEF). Methods An optical imaging system, based on a modified slit lamp biomicroscope, was developed for simultaneous measurements of retinal vascular diameter (D) and oxygen saturation (SO2). Retinal images were acquired in 20 healthy subjects before and during light flicker stimulation. Arterial and venous D (DA and DV) and SO2 (SO2A and SO2V) were quantified within a circumpapillary region. Oxygen extraction fraction was defined as the ratio of MO2 to DO2 and was calculated as (SO2A − SO2V)/SO2A. Reproducibility of measurements was assessed. Results Coefficients of variation and intraclass correlation coefficients of repeated measurements were <5% and ≥0.83, respectively. During light flicker stimulation, DA, DV , and SO2V significantly increased (P ≤ 0.004). Oxygen extraction fraction was 0.37 ± 0.08 before light flicker and significantly decreased to 0.31 ± 0.07 during light flicker (P = 0.001). Conclusions Oxygen extraction fraction before and during light flicker stimulation is reported in human subjects for the first time. Oxygen extraction fraction decreased during light flicker stimulation, indicating the change in DO2 exceeded that of MO2. This technology is potentially useful for the detection of changes in OEF response to light flicker in physiological and pathological retinal conditions. PMID:26469748

  2. Systems for deep brain stimulation: review of technical features.

    Science.gov (United States)

    Amon, A; Alesch, F

    2017-09-01

    The use of deep brain stimulation (DBS) is an important treatment option for movement disorders and other medical conditions. Today, three major manufacturers provide implantable systems for DBS. Although the underlying principle is basically the same for all available systems, the differences in the technical features vary considerably. This article outlines aspects regarding the technical features of DBS systems. The differences between voltage and current sources are addressed and their effect on stimulation is shown. To maintain clinical benefit and minimize side effects the stimulation field has to be adapted to the requirements of the patient. Shaping of the stimulation field can be achieved by the electrode design and polarity configuration. Furthermore, the electric signal consisting of stimulation rate, stimulation amplitude and pulse width affect the stimulation field. Interleaving stimulation is an additional concept, which permits improved treatment outcomes. Therefore, the electrode design, the polarity, the electric signal, and the concept of interleaving stimulation are presented. The investigated systems can be also categorized as rechargeable and non-rechargeable, which is briefly discussed. Options for interconnecting different system components from various manufacturers are presented. The present paper summarizes the technical features and their combination possibilities, which can have a major impact on the therapeutic effect.

  3. The effects of transcranial direct current stimulation in patients with neuropathic pain from spinal cord injury.

    Science.gov (United States)

    Ngernyam, Niran; Jensen, Mark P; Arayawichanon, Preeda; Auvichayapat, Narong; Tiamkao, Somsak; Janjarasjitt, Suparerk; Punjaruk, Wiyada; Amatachaya, Anuwat; Aree-uea, Benchaporn; Auvichayapat, Paradee

    2015-02-01

    Transcranial direct current stimulation (tDCS) has demonstrated efficacy for reducing neuropathic pain, but the respective mechanisms remain largely unknown. The current study tested the hypothesis that pain reduction with tDCS is associated with an increase in the peak frequency spectrum density in the theta-alpha range. Twenty patients with spinal cord injury and bilateral neuropathic pain received single sessions of both sham and anodal tDCS (2 mA) over the left primary motor area (M1) for 20 min. Treatment order was randomly assigned. Pre- to post-procedure changes in pain intensity and peak frequency of electroencephalogram spectral analysis were compared between treatment conditions. The active treatment condition (anodal tDCS over M1) but not sham treatment resulted in significant decreases in pain intensity. In addition, consistent with the study hypothesis, peak theta-alpha frequency (PTAF) assessed from an electrode placed over the site of stimulation increased more from pre- to post-session among participants in the active tDCS condition, relative to those in the sham tDCS condition. Moreover, we found a significant association between a decrease in pain intensity and an increase in PTAF at the stimulation site. The findings are consistent with the possibility that anodal tDCS over the left M1 may be effective, at least in part, because it results in an increase in M1 cortical excitability, perhaps due to a pain inhibitory effect of motor cortex stimulation that may influence the descending pain modulation system. Future research is needed to determine if there is a causal association between increased left anterior activity and pain reduction. The results provide new findings regarding the effects of tDCS on neuropathic pain and brain oscillation changes. Copyright © 2014 International Federation of Clinical Neurophysiology. All rights reserved.

  4. A distributed current stimulator ASIC for high density neural stimulation.

    Science.gov (United States)

    Jeong Hoan Park; Chaebin Kim; Seung-Hee Ahn; Tae Mok Gwon; Joonsoo Jeong; Sang Beom Jun; Sung June Kim

    2016-08-01

    This paper presents a novel distributed neural stimulator scheme. Instead of a single stimulator ASIC in the package, multiple ASICs are embedded at each electrode site for stimulation with a high density electrode array. This distributed architecture enables the simplification of wiring between electrodes and stimulator ASIC that otherwise could become too complex as the number of electrode increases. The individual ASIC chip is designed to have a shared data bus that independently controls multiple stimulating channels. Therefore, the number of metal lines is determined by the distributed ASICs, not by the channel number. The function of current steering is also implemented within each ASIC in order to increase the effective number of channels via pseudo channel stimulation. Therefore, the chip area can be used more efficiently. The designed chip was fabricated with area of 0.3 mm2 using 0.18 μm BCDMOS process, and the bench-top test was also conducted to validate chip performance.

  5. Four stimulants of the central nervous system: effects on short-term memory in young versus aged monkeys.

    Science.gov (United States)

    Bartus, R T

    1979-07-01

    Aged Rhesus monkeys and young control monkeys were tested in a delayed-response procedure to assess the effects of central-nervous-system (CNS) stimulants on short-term memory (STM). Previous research had established that the aged monkeys showed specific impairments of STM in this procedure. Four different CNS stimulants (methylphenidate, magnesium pemoline, a pentylenetetrazole/niacin mixture, and caffeine) were chosen for evaluation on the basis of their relevancy to current geriatric-psychopharmacologic research. Four different doses of each of the four CNS stimulants were given to each monkey, counter-balanced for possible order effects. Methylphenidate and caffeine impaired the performance of both age groups in this non-human primate cognitive task, even at relatively low dose levels. Magnesium pemoline produced fewer adverse effects and some evidence of improving STM in the aged monkeys, although not within the levels of statistical significance. The pentylenetetrazole/niacin mixture produced a three-way interaction involving age, dose and retention interval. This reflected the fact that although no definite effects were noted under the zero-sec control condition, statistically significant age-related deficits did occur in the STM-dependent retention interval as the dose varied. The data demonstrate that, of these four CNS stimulants, none radily improves (and often may impair) performance of tasks requiring STM. Thus the results of this study offer little support for the hypothesis that general CNS stimulation may constitute significant therapy for cognitive impairments associated with advanced age.

  6. A novel brain stimulation technology provides compatibility with MRI.

    Science.gov (United States)

    Serano, Peter; Angelone, Leonardo M; Katnani, Husam; Eskandar, Emad; Bonmassar, Giorgio

    2015-04-29

    Clinical electrical stimulation systems--such as pacemakers and deep brain stimulators (DBS)--are an increasingly common therapeutic option to treat a large range of medical conditions. Despite their remarkable success, one of the significant limitations of these medical devices is the limited compatibility with magnetic resonance imaging (MRI), a standard diagnostic tool in medicine. During an MRI exam, the leads used with these devices, implanted in the body of the patient, act as an electric antenna potentially causing a large amount of energy to be absorbed in the tissue, which can lead to serious heat-related injury. This study presents a novel lead design that reduces the antenna effect and allows for decreased tissue heating during MRI. The optimal parameters of the wire design were determined by a combination of computational modeling and experimental measurements. The results of these simulations were used to build a prototype, which was tested in a gel phantom during an MRI scan. Measurement results showed a three-fold decrease in heating when compared to a commercially available DBS lead. Accordingly, the proposed design may allow a significantly increased number of patients with medical implants to have safe access to the diagnostic benefits of MRI.

  7. Coordination of eye and head components of movements evoked by stimulation of the paramedian pontine reticular formation

    Science.gov (United States)

    Barton, Ellen J.; Sparks, David L.

    2013-01-01

    Constant frequency microstimulation of the paramedian pontine reticular formation (PPRF) in head-restrained monkeys evokes a constant velocity eye movement. Since the PPRF receives significant projections from structures that control coordinated eye-head movements, we asked whether stimulation of the pontine reticular formation in the head-unrestrained animal generates a combined eye-head movement or only an eye movement. Microstimulation of most sites yielded a constant-velocity gaze shift executed as a coordinated eye-head movement, although eye-only movements were evoked from some sites. The eye and head contributions to the stimulation-evoked movements varied across stimulation sites and were drastically different from the lawful relationship observed for visually-guided gaze shifts. These results indicate that the microstimulation activated elements that issued movement commands to the extraocular and, for most sites, neck motoneurons. In addition, the stimulation-evoked changes in gaze were similar in the head-restrained and head-unrestrained conditions despite the assortment of eye and head contributions, suggesting that the vestibuloocular reflex (VOR) gain must be near unity during the coordinated eye-head movements evoked by stimulation of the PPRF. These findings contrast the attenuation of VOR gain associated with visually-guided gaze shifts and suggest that the vestibulo-ocular pathway processes volitional and PPRF stimulation-evoked gaze shifts differently. PMID:18458891

  8. Isotope tracer-aided studies on the date and significance of insecticides used for the control of rice pests under conditions of Indian agriculture. Coordinate programme on isotopic-tracer-aided studies on the origin and fate of foreign chemical residues in the agricultural environment

    International Nuclear Information System (INIS)

    Sethunathan, N.

    1976-01-01

    Radiotracer-aided studies were made of the fate of insecticides: parathion, benzenehexachloride (BHC) and endrin in rice soils under flooded conditions and the effect of a fungicide benomyl on heterotrophic nitrification. BHC, known for its stability in non-flooded soils and other aerobic environments, decomposed rapidly in microbially-active flooded soils, capable of obtaining Eh of -40 to -100 mV. Moreover the addition of rice straw (a common cultural practice) further accelerated the Eh drop due to enhanced microbial activity and, thereby, BHC degradation. Substantial loss of gamma-BHC also occurred by volatilization from the standing water of flooded soils. The fate of endrin was studied in 8 rice-flooded soils. Endrin decomposed rapidly in most soils, except in a sandy one. Endrin was converted to 6 metabolites in non-sterile samples of laterite, alluvial and pokkali soils as compared to 3 compounds in sterile samples indicating microbial participation. In sandy soils also only 3 compounds were detected and in kari soil 4. The degradation of parathion in flooded soils proceeds by nitrogroup reduction to amino-parathion and by hydrolysis of the P-O-C linkage to P-nitrophenol and diethylthiophosphoric acid. Microorganisms, Penicillium waksmani Zoleski, Pseudomonas sp. and Bacillus sp. are involved in both reactions. Organic sources inhibited the parathion hydrolysis but it is unlikely to cause any residue hazards since at the same time nitrogroup reduction is enhanced. Applications of benomyl to the simulated oxidized zone of flooded soils favoured heterotrophic nitrification due to stimulating the proliferation of heterotrophic nitrifying bacteria. This may pose an indirect environmental pollution hazard in addition to the direct toxicity of the fungicide

  9. Influence of Transcranial Direct Current Stimulation to the Cerebellum on Standing Posture Control

    Directory of Open Access Journals (Sweden)

    Yasuto Inukai

    2016-07-01

    Full Text Available Damage to the vestibular cerebellum results in dysfunctional standing posture control. Patients with cerebellum dysfunction have a larger sway in the center of gravity while standing compared with healthy subjects. Transcranial direct current stimulation (tDCS is a noninvasive technique for selectively exciting or inhibiting specific neural structures with potential applications in functional assessment and treatment of neural disorders. However, the specific stimulation parameters for influencing postural control have not been assessed. In this study, we investigated the influence of tDCS when applied over the cerebellum on standing posture control. Sixteen healthy subjects received tDCS (20 min, 2 mA over the scalp 2 cm below the inion. In experiment 1, all 16 subjects received tDCS under three stimulus conditions, Sham, Cathodal, and Anodal, in a random order with the second electrode placed on the forehead. In experiment 2, five subjects received cathodal stimulation only with the second electrode placed over the right buccinator muscle. Center of gravity sway was measured twice for 60 s before and after tDCS in a standing posture with eyes open and legs closed, and average total locus length, locus length per second, rectangular area, and enveloped area were calculated. In experiment 1, total locus length and locus length per second decreased significantly after cathodal stimulation but not after anodal or sham stimulation, while no tDCS condition influenced rectangular or enveloped areas. In experiment 2, cathodal tDCS again significantly reduced total locus length and locus length per second but not rectangular and enveloped areas. The effects of tDCS on postural control are polarity-dependent, likely reflecting the selective excitation or inhibition of cerebellar Purkinje cells. Cathodal tDCS to the cerebellum of healthy subjects can alter body sway (velocity.

  10. Power Conditioning and Stimulation for Wireless Neural Interface ICs

    OpenAIRE

    Biederman, William

    2014-01-01

    Brain machine interfaces have the potential to revolutionize our understanding of the brain, restore motor function, and improve the quality of life to patients with neurological con- ditions. In recent human trials, control of robotic prostheses has been demonstrated using micro-electrode arrays, which provide high spatio-temporal resolution and an electrical feed- back path to the brain. However, after implantation, scar tissue degrades the recording signal-to-noise ratio and limits the use...

  11. Human embryo-conditioned medium stimulates in vitro endometrial angiogenesis

    NARCIS (Netherlands)

    Kapiteijn, K.; Koolwijk, P.; Weiden, R.M.F. van der; Nieuw Amerongen, G. van; Plaisier, M.; Hinsbergh, V.W.M. van; Helmerhorst, F.M.

    2006-01-01

    Objective: Successful implantation and placentation depend on the interaction between the endometrium and the embryo. Angiogenesis is crucial at this time. In this article we investigate the direct influence of the human embryo on in vitro endometrial angiogenesis. Design: In vitro study. Setting:

  12. Onsite-effects of dual-hemisphere versus conventional single-hemisphere transcranial direct current stimulation

    Science.gov (United States)

    Kwon, Yong Hyun; Jang, Sung Ho

    2012-01-01

    We performed functional MRI examinations in six right-handed healthy subjects. During functional MRI scanning, transcranial direct current stimulation was delivered with the anode over the right primary sensorimotor cortex and the cathode over the left primary sensorimotor cortex using dual-hemispheric transcranial direct current stimulation. This was compared to a cathode over the left supraorbital area using conventional single-hemispheric transcranial direct current stimulation. Voxel counts and blood oxygenation level-dependent signal intensities in the right primary sensorimotor cortex regions were estimated and compared between the two transcranial direct current stimulation conditions. Our results showed that dual-hemispheric transcranial direct current stimulation induced greater cortical activities than single-hemispheric transcranial direct current stimulation. These findings suggest that dual-hemispheric transcranial direct current stimulation may provide more effective cortical stimulation than single-hemispheric transcranial direct current stimulation. PMID:25624815

  13. Stimulated Thomson scattering

    International Nuclear Information System (INIS)

    Spencer, R.L.

    1979-03-01

    The theory of stimulated Thomson scattering is investigated both quantum mechanically and classically. Two monochromatic electromagnetic waves of like polarization travelling in opposite directions are allowed to interact for a time tau with the electrons in a collisionless plasma. The electromagnetic waves have frequencies well above the plasma frequency, and their difference frequency is allowed to range upward from the plasma frequency. With the difference frequency well above the plasma frequency, the rate at which energy is transferred from one wave to the other is calculated quantum mechanically, classically from a fluid theory, and classically from an independent electron theory. The rate is calculated in both the homogeneously broadened limit, and in the inhomogeneously broadened limit

  14. Engagement sensitive visual stimulation

    Directory of Open Access Journals (Sweden)

    Deepesh Kumar

    2016-06-01

    Full Text Available Stroke is one of leading cause of death and disability worldwide. Early detection during golden hour and treatment of individual neurological dysfunction in stroke using easy-to-access biomarkers based on a simple-to-use, cost-effective, clinically-valid screening tool can bring a paradigm shift in healthcare, both urban and rural. In our research we have designed a quantitative automatic home-based oculomotor assessment tool that can play an important complementary role in prognosis of neurological disorders like stroke for the neurologist. Once the patient has been screened for stroke, the next step is to design proper rehabilitation platform to alleviate the disability. In addition to the screening platform, in our research, we work in designing virtual reality based rehabilitation exercise platform that has the potential to deliver visual stimulation and in turn contribute to improving one’s performance.

  15. Stimulated coherent transition radiation

    International Nuclear Information System (INIS)

    Hung-chi Lihn.

    1996-03-01

    Coherent radiation emitted from a relativistic electron bunch consists of wavelengths longer than or comparable to the bunch length. The intensity of this radiation out-numbers that of its incoherent counterpart, which extends to wavelengths shorter than the bunch length, by a factor equal to the number of electrons in the bunch. In typical accelerators, this factor is about 8 to 11 orders of magnitude. The spectrum of the coherent radiation is determined by the Fourier transform of the electron bunch distribution and, therefore, contains information of the bunch distribution. Coherent transition radiation emitted from subpicosecond electron bunches at the Stanford SUNSHINE facility is observed in the far-infrared regime through a room-temperature pyroelectric bolometer and characterized through the electron bunch-length study. To measure the bunch length, a new frequency-resolved subpicosecond bunch-length measuring system is developed. This system uses a far-infrared Michelson interferometer to measure the spectrum of coherent transition radiation through optical autocorrelation with resolution far better than existing time-resolved methods. Hence, the radiation spectrum and the bunch length are deduced from the autocorrelation measurement. To study the stimulation of coherent transition radiation, a special cavity named BRAICER is invented. Far-infrared light pulses of coherent transition radiation emitted from electron bunches are delayed and circulated in the cavity to coincide with subsequent incoming electron bunches. This coincidence of light pulses with electron bunches enables the light to do work on electrons, and thus stimulates more radiated energy. The possibilities of extending the bunch-length measuring system to measure the three-dimensional bunch distribution and making the BRAICER cavity a broadband, high-intensity, coherent, far-infrared light source are also discussed

  16. Investigating the Effects of Vestibular Stimulation on Balance Performance in Children with Cerebral Palsy: A Randomized Clinical Trial Study

    Directory of Open Access Journals (Sweden)

    Seyed Ali Hosseini

    2015-06-01

    Full Text Available Background: Centre of pressure displacement is an indicator of postural control. Children with cerebral palsy have poor postural control. One common intervention to enhance their balance is vestibular stimulation. The aim of this research was to investigate the effect of vestibular stimulation on COP parameters in children with cerebral palsy (3-10 years old. Methods: This study was a randomized double-blind controlled clinical trial. Twenty children with cerebral palsy received vestibular stimulation, two sessions per week with a course of twelve sessions, based on vestibular stimulation protocol including anteroposterior, lateral, ascending–descending movements and spinning. One cerebral palsy group experienced current and conventional occupational therapy while the other received a period of vestibular stimulation during treatment. Force plate outcome measures were center of pressure displacement parameters as well as velocity, area, displacement in X and Y axes. Results: According to Mann-Whitney U test, means in post-tests in two groups with both conditions of eyes open and closed were significant in velocity parameter (eyes open P=0.036; eyes closed P=0.021 while Area parameter, COP displacement in X axis (Rang fore after, COP displacement in Y axis (Rang side way were not significant (P>0.05. Wilcoxon Test showed significant difference in the velocity parameter; eyes open (P=0.012 and eyes closed (P=0.018. Conclusion: Children who received vestibular stimulation are able to change and control COP displacement faster (according to changes in velocity parameters. So we suggest rehabilitation team members especially occupational therapist to apply vestibular stimulation during their treatment.

  17. Transdermal optogenetic peripheral nerve stimulation

    Science.gov (United States)

    Maimon, Benjamin E.; Zorzos, Anthony N.; Bendell, Rhys; Harding, Alexander; Fahmi, Mina; Srinivasan, Shriya; Calvaresi, Peter; Herr, Hugh M.

    2017-06-01

    Objective: A fundamental limitation in both the scientific utility and clinical translation of peripheral nerve optogenetic technologies is the optical inaccessibility of the target nerve due to the significant scattering and absorption of light in biological tissues. To date, illuminating deep nerve targets has required implantable optical sources, including fiber-optic and LED-based systems, both of which have significant drawbacks. Approach: Here we report an alternative approach involving transdermal illumination. Utilizing an intramuscular injection of ultra-high concentration AAV6-hSyn-ChR2-EYFP in rats. Main results: We demonstrate transdermal stimulation of motor nerves at 4.4 mm and 1.9 mm depth with an incident laser power of 160 mW and 10 mW, respectively. Furthermore, we employ this technique to accurately control ankle position by modulating laser power or position on the skin surface. Significance: These results have the potential to enable future scientific optogenetic studies of pathologies implicated in the peripheral nervous system for awake, freely-moving animals, as well as a basis for future clinical studies.

  18. Avoiding Internal Capsule Stimulation With a New Eight-Channel Steering Deep Brain Stimulation Lead.

    Science.gov (United States)

    van Dijk, Kees J; Verhagen, Rens; Bour, Lo J; Heida, Ciska; Veltink, Peter H

    2017-10-15

    Novel deep brain stimulation (DBS) lead designs are currently entering the market, which are hypothesized to provide a way to steer the stimulation field away from neural populations responsible for side effects and towards populations responsible for beneficial effects. The objective of this study is to assess the performances of a new eight channel steering-DBS lead and compare this with a conventional cylindrical contact (CC) lead. The two leads were evaluated in a finite element electric field model combined with multicompartment neuron and axon models, representing the internal capsule (IC) fibers and subthalamic nucleus (STN) cells. We defined the optimal stimulation setting as the configuration that activated the highest percentage of STN cells, without activating any IC fibers. With this criterion, we compared monopolar stimulation using a single contact of the steering-DBS lead and CC lead, on three locations and four orientations of the lead. In addition, we performed a current steering test case by dividing the current over two contacts with the steering-DBS lead in its worst-case orientation. In most cases, the steering-DBS lead is able to stimulate a significantly higher percentage of STN cells compared to the CC lead using single contact stimulation or using a two contact current steering protocol when there is approximately a 1 mm displacement of the CC lead. The results also show that correct placement and orientation of the lead in the target remains an important aspect in achieving the optimal stimulation outcome. Currently, clinical trials are set up in Europe with a similar design as the steering-DBS lead. Our results illustrate the importance of the orientation of the new steering-DBS lead in avoiding side effects induced by stimulation of IC fibers. Therefore, in clinical trials sufficient attention should be paid to implanting the steering DBS-lead in the most effective orientation. © 2017 International Neuromodulation Society.

  19. TBA biodegradation in surface-water sediments under aerobic and anaerobic conditions.

    Science.gov (United States)

    Bradley, Paul M; Landmeyer, James E; Chapelle, Francis H

    2002-10-01

    The potential for [U-14C] TBA biodegradation was examined in laboratory microcosms under a range of terminal electron accepting conditions. TBA mineralization to CO2 was substantial in surface-water sediments under oxic, denitrifying, or Mn(IV)-reducing conditions and statistically significant but low under SO4-reducing conditions. Thus, anaerobic TBA biodegradation may be a significant natural attenuation mechanism for TBA in the environment, and stimulation of in situ TBA bioremediation by addition of suitable terminal electron acceptors may be feasible. No degradation of [U-14C] TBA was observed under methanogenic or Fe(III)-reducing conditions.

  20. Dysregulation of the descending pain system in temporomandibular disorders revealed by low-frequency sensory transcutaneous electrical nerve stimulation: a pupillometric study.

    Directory of Open Access Journals (Sweden)

    Annalisa Monaco

    Full Text Available Using computerized pupillometry, our previous research established that the autonomic nervous system (ANS is dysregulated in patients suffering from temporomandibular disorders (TMDs, suggesting a potential role for ANS dysfunction in pain modulation and the etiology of TMD. However, pain modulation hypotheses for TMD are still lacking. The periaqueductal gray (PAG is involved in the descending modulation of defensive behavior and pain through μ, κ, and δ opioid receptors. Transcutaneous electrical nerve stimulation (TENS has been extensively used for pain relief, as low-frequency stimulation can activate µ receptors. Our aim was to use pupillometry to evaluate the effect of low-frequency TENS stimulation of μ receptors on opioid descending pathways in TMD patients. In accordance with the Research Diagnostic Criteria for TMD, 18 females with myogenous TMD and 18 matched-controls were enrolled. All subjects underwent subsequent pupillometric evaluations under dark and light conditions before, soon after (end of stimulation and long after (recovery period sensorial TENS. The overall statistics derived from the darkness condition revealed no significant differences in pupil size between cases and controls; indeed, TENS stimulation significantly reduced pupil size in both groups. Controls, but not TMD patients, displayed significant differences in pupil size before compared with after TENS. Under light conditions, TMD patients presented a smaller pupil size compared with controls; the pupil size was reduced only in the controls. Pupil size differences were found before and during TENS and before and after TENS in the controls only. Pupillometry revealed that stimulating the descending opioid pathway with low-frequency sensory TENS of the fifth and seventh pairs of cranial nerves affects the peripheral target. The TMD patients exhibited a different pattern of response to TENS stimulation compared with the controls, suggesting that impaired

  1. Inhibition of stimulated Raman scattering due to the excitation of stimulated Brillouin scattering

    Science.gov (United States)

    Zhao, Yao; Yu, Lu-Le; Weng, Su-Ming; Ren, Chuang; Liu, Chuan-Sheng; Sheng, Zheng-Ming

    2017-09-01

    The nonlinear coupling between stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SBS) of intense laser in underdense plasma is studied theoretically and numerically. Based upon the fluid model, their coupling equations are derived, and a threshold condition of plasma density perturbations due to SBS for the inhibition of SRS is given. Particle-in-cell simulations show that this condition can be achieved easily by SBS in the so-called fluid regime with kLλDDebye length [Kline et al., Phys. Plasmas 13, 055906 (2006)]. SBS can reduce the saturation level of SRS and the temperature of electrons in both homogeneous and inhomogeneous plasma. Numerical simulations also show that this reduced SRS saturation is retained even if the fluid regime condition mentioned above is violated at a later time due to plasma heating.

  2. Ultrasound stimulation on bone healing. The optimization of stimulation time

    International Nuclear Information System (INIS)

    Rosim, R.C.; Paulin, J.B.P.; Goncalves, R.P.

    1990-01-01

    Previous works in ultrasonic simulation of bone healing dealt with parameters optimization. Albertin (1983) studied the stimulation time and found forty minutes as ideal. However, this stimulation time was the largest one employed and remained some doubt about the most appropriated value. 30, 40, 50 and 60 minutes of stimulation time were selected, while others parameters were held constant with: pulse width in 200 μs, repetition rate in 1000 pulses per second and amplitude in 30 V. Partial incomplete transverse osteotomies were done in the middle third of radio in the right forearm of rabbits. Twenty four animals divided in four subgroups, with 6 animals each were stimulated. The daily stimulation time for each subgroup was 30, 40, 50 and minutes respectively, during 15 consecutive days. The stimulation procedure started 24 hours after surgery. After the stimulation period, radiological, histological and morphometric evaluations were done and greater bone healing was found for the 50 minutes stimulation subgroup, in them new bone was also prominent. (author)

  3. Electrical stimulation of schwann cells promotes sustained increases in neurite outgrowth.

    Science.gov (United States)

    Koppes, Abigail N; Nordberg, Andrea L; Paolillo, Gina M; Goodsell, Nicole M; Darwish, Haley A; Zhang, Linxia; Thompson, Deanna M

    2014-02-01

    Endogenous electric fields are instructive during embryogenesis by acting to direct cell migration, and postnatally, they can promote axonal growth after injury (McCaig 1991, Al-Majed 2000). However, the mechanisms for these changes are not well understood. Application of an appropriate electrical stimulus may increase the rate and success of nerve repair by directly promoting axonal growth. Previously, DC electrical stimulation at 50 mV/mm (1 mA, 8 h duration) was shown to promote neurite outgrowth and a more pronounced effect was observed if both peripheral glia (Schwann cells) and neurons were co-stimulated. If electrical stimulation is delivered to an injury site, both the neurons and all resident non-neuronal cells [e.g., Schwann cells, endothelial cells, fibroblasts] will be treated and this biophysical stimuli can influence axonal growth directly or indirectly via changes to the resident, non-neuronal cells. In this work, non-neuronal cells were electrically stimulated, and changes in morphology and neuro-supportive cells were evaluated. Schwann cell response (morphology and orientation) was examined after an 8 h stimulation over a range of DC fields (0-200 mV/mm, DC 1 mA), and changes in orientation were observed. Electrically prestimulating Schwann cells (50 mV/mm) promoted 30% more neurite outgrowth relative to co-stimulating both Schwann cells with neurons, suggesting that electrical stimulation modifies Schwann cell phenotype. Conditioned medium from the electrically prestimulated Schwann cells promoted a 20% increase in total neurite outgrowth and was sustained for 72 h poststimulation. An 11-fold increase in nerve growth factor but not brain-derived neurotrophic factor or glial-derived growth factor was found in the electrically prestimulated Schwann cell-conditioned medium. No significant changes in fibroblast or endothelial morphology and neuro-supportive behavior were observed poststimulation. Electrical stimulation is widely used in

  4. Transcranial brain stimulation: closing the loop between brain and stimulation

    DEFF Research Database (Denmark)

    Karabanov, Anke; Thielscher, Axel; Siebner, Hartwig Roman

    2016-01-01

    -related and state-related variability. Fluctuations in brain-states can be traced online with functional brain imaging and inform the timing or other settings of transcranial brain stimulation. State-informed open-loop stimulation is aligned to the expression of a predefined brain state, according to prespecified......PURPOSE OF REVIEW: To discuss recent strategies for boosting the efficacy of noninvasive transcranial brain stimulation to improve human brain function. RECENT FINDINGS: Recent research exposed substantial intra- and inter-individual variability in response to plasticity-inducing transcranial brain...... stimulation. Trait-related and state-related determinants contribute to this variability, challenging the standard approach to apply stimulation in a rigid, one-size-fits-all fashion. Several strategies have been identified to reduce variability and maximize the plasticity-inducing effects of noninvasive...

  5. Effects of Navigated Repetitive Transcranial Magnetic Stimulation After Stroke.

    Science.gov (United States)

    Chervyakov, Alexander V; Poydasheva, Alexandra G; Lyukmanov, Roman H; Suponeva, Natalia A; Chernikova, Ludmila A; Piradov, Michael A; Ustinova, Ksenia I

    2018-03-01

    The purpose of this study was to test the effects of navigated repetitive transcranial magnetic stimulation, delivered in different modes, on motor impairments and functional limitations after stroke. The study sample included 42 patients (58.5 ± 10.7 years; 26 males) who experienced a single unilateral stroke (1-12 months previously) in the area of the middle cerebral artery. Patients completed a course of conventional rehabilitation, together with 10 sessions of navigated repetitive transcranial magnetic stimulation or sham stimulation. Stimulation was scheduled five times a week over two consecutive weeks in an inpatient clinical setting. Patients were randomly assigned to one of four groups and received sham stimulation (n = 10), low-frequency (1-Hz) stimulation of the nonaffected hemisphere (n = 11), high-frequency (10-Hz) stimulation of the affected hemisphere (n = 13), or sequential combination of low- and high-frequency stimulations (n = 8). Participants were evaluated before and after stimulation with clinical tests, including the arm and hand section of the Fugl-Meyer Assessment Scale, modified Ashworth Scale of Muscle Spasticity, and Barthel Index of Activities of Daily Living. Participants in the three groups receiving navigated repetitive transcranial magnetic stimulation showed improvements in arm and hand functions on the Fugl-Meyer Stroke Assessment Scale. Ashworth Scale of Muscle Spasticity and Barthel Index scores were significantly reduced in groups receiving low- or high-frequency stimulation alone. Including navigated repetitive transcranial magnetic stimulation in a conventional rehabilitation program positively influenced motor and functional recovery in study participants, demonstrating the clinical potential of the method. The results of this study will be used for designing a large-scale clinical trial.

  6. Bilateral Alternating Auditory Stimulations Facilitate Fear Extinction and Retrieval

    Directory of Open Access Journals (Sweden)

    Sarah Boukezzi

    2017-06-01

    Full Text Available Disruption of fear conditioning, its extinction and its retrieval are at the core of posttraumatic stress disorder (PTSD. Such deficits, especially fear extinction delay, disappear after alternating bilateral stimulations (BLS during eye movement desensitization and reprocessing (EMDR therapy. An animal model of fear recovery, based on auditory cued fear conditioning and extinction learning, recently showed that BLS facilitate fear extinction and fear extinction retrieval. Our goal was to determine if these previous results found in animals can be reproduced in humans. Twenty-two healthy participants took part in a classical fear conditioning, extinction, and extinction recall paradigm. Behavioral responses (fear expectations as well as psychophysiological measures (skin conductance responses, SCRs were recorded. The results showed a significant fear expectation decrease during fear extinction with BLS. Additionally, SCR for fear extinction retrieval were significantly lower with BLS. Our results demonstrate the importance of BLS to reduce negative emotions, and provide a successful model to further explore the neural mechanisms underlying the sole BLS effect in the EMDR.

  7. ANODAL TRANSCRANIAL DIRECT CURRENT STIMULATION (TDCS) INCREASES ISOMETRIC STRENGTH OF SHOULDER ROTATORS MUSCLES IN HANDBALL PLAYERS.

    Science.gov (United States)

    Hazime, Fuad Ahmad; da Cunha, Ronaldo Alves; Soliaman, Renato Rozenblit; Romancini, Ana Clara Bezerra; Pochini, Alberto de Castro; Ejnisman, Benno; Baptista, Abrahão Fontes

    2017-06-01

    Weakness of the rotator cuff muscles can lead to imbalances in the strength of shoulder external and internal rotators, change the biomechanics of the glenohumeral joint and predispose an athlete to injury. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that has demonstrated promising results in a variety of health conditions. However few studies addressed its potential approach in the realm of athletics. The purpose of this study was to investigate if transcranial direct current stimulation (tDCS) technique increases the isometric muscle strength of shoulder external and internal rotators in handball athletes. Randomized, double-blind, placebo-controlled, crossover study. Eight female handball players aged between 17 and 21 years (Mean=19.65; SD=2.55) with 7.1 ± 4.8 years of experience in training, participating in regional and national competitions were recruited. Maximal voluntary isometric contraction (MVIC) of shoulder external and internal rotator muscles was evaluated during and after 30 and 60 minutes post one session of anodal and sham current (2mA; 0.057mA/cm 2 ) with a one-week interval between stimulations. Compared to baseline, MVIC of shoulder external and internal rotators significantly increased after real but not sham tDCS. Between-group differences were observed for external and internal rotator muscles. Maximal voluntary isometric contraction of external rotation increased significantly during tDCS, and 30 and 60 minutes post-tDCS for real tDCS compared to that for sham tDCS. For internal rotation MVIC increased significantly during and 60 minutes post-tDCS. The results indicate that transcranial direct current stimulation temporarily increases maximal isometric contractions of the internal and external rotators of the shoulder in handball players. 2.

  8. Facilitating Access to Emotions: Neural Signature of EMDR Stimulation

    Science.gov (United States)

    Herkt, Deborah; Tumani, Visal; Grön, Georg; Kammer, Thomas; Hofmann, Arne; Abler, Birgit

    2014-01-01

    Background Eye Movement Desensitisation and Reprocessing (EMDR) is a method in psychotherapy effective in treating symptoms of posttraumatic stress disorder. The client attends to alternating bilateral visual, auditory or sensory stimulation while confronted with emotionally disturbing material. It is thought that the bilateral stimulation as a specific element of EMDR facilitates accessing and processing of negative material while presumably creating new associative links. We hypothesized that the putatively facilitated access should be reflected in increased activation of the amygdala upon bilateral EMDR stimulation even in healthy subjects. Methods We investigated 22 healthy female university students (mean 23.5 years) with fMRI. Subjects were scanned while confronted with blocks of disgusting and neutral picture stimuli. One third of the blocks was presented without any additional stimulation, one third with bilateral simultaneous auditory stimulation, and one third with bilateral alternating auditory stimulation as used in EMDR. Results Contrasting disgusting vs. neutral picture stimuli confirmed the expected robust effect of amygdala activation for all auditory stimulation conditions. The interaction analysis with the type of auditory stimulation revealed a specific increase in activation of the right amygdala for the bilateral alternating auditory stimulation. Activation of the left dorsolateral prefrontal cortex showed the opposite effect with decreased activation. Conclusions We demonstrate first time evidence for a putative neurobiological basis of the bilateral alternating stimulation as used in the EMDR method. The increase in limbic processing along with decreased frontal activation is in line with theoretical models of how bilateral alternating stimulation could help with therapeutic reintegration of information, and present findings may pave the way for future research on EMDR in the context of posttraumatic stress disorder. PMID:25165974

  9. The Mechanism of Financial Stimulation of Investment Activity

    Directory of Open Access Journals (Sweden)

    Vasiliy Valeryevich Tarakanov

    2016-03-01

    Full Text Available Modernization of the Russian economy and creation of conditions for its economic growth demand activization of investment activity that is possible by means of its financial stimulation. Financial stimulation of investment activity defines the need of changes of the contents, the directions and ways of implementation of the financial relations between subjects of investment activity. Financial stimulation of investment activity is carried out via the mechanism in the context of which these financial relations are settled. For defining the mechanism of financial stimulation of investment activity the authors consider the very concept of financial mechanism. The conclusion is drawn that all elements of the financial mechanism are the integrated unity, they are interdependent and interconnected, and the combination of types, forms, methods of the organization of the financial relations forms “a design of the financial mechanism”. The article specifies the maintenance of the mechanism of financial stimulation of investment activity, and reveals its essence. The structure of the mechanism of financial stimulation of investment activity is presented by the following elements: subjects of financial stimulation of investment activity, the purpose of attraction of investments by them, set of financial methods and tools, sources of means of achievement of goals, standard - legal and information support of financial stimulation of investment activity. It is proved that in the mechanism of financial stimulation of investment activity the leading role is played by the state by means of forms of direct and indirect participation in attraction of investments, each of which is realized by means of specific methods and the corresponding tools. The widespread instrument of financial stimulation of investment activity is the investments which are carried out by the state institutes of development participating in the organization of the process of financial

  10. Can a single pulse transcranial magnetic stimulation targeted to the motor cortex interrupt pain processing?

    Science.gov (United States)

    Kisler, Lee-Bareket; Gurion, Ilan; Granovsky, Yelena; Sinai, Alon; Sprecher, Elliot; Shamay-Tsoory, Simone; Weissman-Fogel, Irit

    2018-01-01

    The modulatory role of the primary motor cortex (M1), reflected by an inhibitory effect of M1-stimulation on clinical pain, motivated us to deepen our understanding of M1's role in pain modulation. We used Transcranial Magnetic Stimulation (TMS)-induced virtual lesion (VL) to interrupt with M1 activity during noxious heat pain. We hypothesized that TMS-VL will effect experimental pain ratings. Three VL protocols were applied consisting of single-pulse TMS to transiently interfere with right M1 activity: (1) VLM1- TMS applied to 11 subjects, 20 msec before the individual's first pain-related M1 peak activation, as determined by source analysis (sLORETA), (2) VL-50 (N = 16; TMS applied 50 ms prior to noxious stimulus onset), and (3) VL+150 (N = 16; TMS applied 150 ms after noxious stimulus onset). Each protocol included 3 conditions ('pain-alone', ' TMS-VL', and 'SHAM-VL'), each consisted of 30 noxious heat stimuli. Pain ratings were compared, in each protocol, for TMS-VL vs. SHAM-VL and vs. pain-alone conditions. Repeated measures analysis of variance, corrected for multiple comparisons revealed no significant differences in the pain ratings between the different conditions within each protocol. Therefore, our results from this exploratory study suggest that a single pulse TMS-induced VL that is targeted to M1 failed to interrupt experimental pain processing in the specific three stimulation timing examined here.

  11. Effect of multipactor conditioning on technical electrode surfaces

    International Nuclear Information System (INIS)

    Graves, T. P.; Spektor, R.; Stout, P.

    2009-01-01

    Historically, multipactor conditioning has been utilized to remove surface contaminants from rf electrodes by electron-stimulated gas desorption, and such conditioning has been shown to reduce multipactor susceptibility. Multipactor threshold improvements are due to increasing E 1 , the minimum energy for the secondary electron coefficient, δ>1, such that resonant electrons are incapable of producing discharge-sustaining secondary emission. Using an rf amplitude sweep technique, the evolution of the multipactor threshold is measured as a function of multipactor conditioning time for a series of technical electrode surfaces. Results show over +3 dB of threshold improvement in copper and gold electrodes, while the aluminum threshold actually decreases with conditioning exposure. Additionally, these conditioning results indicate the possible voltage region for transient-mode multipaction (TMM), which can cause significant risk to rf systems such as space satellite components for which in-situ conditioning is generally not possible. Experimental results and supporting Monte Carlo particle tracking simulation results are presented.

  12. Modelling the effect of electrode displacement on transcranial direct current stimulation (tDCS)

    Science.gov (United States)

    Ramaraju, Sriharsha; Roula, Mohammed A.; McCarthy, Peter W.

    2018-02-01

    Objective. Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that delivers a low-intensity, direct current to cortical areas with the purpose of modulating underlying brain activity. Recent studies have reported inconsistencies in tDCS outcomes. The underlying assumption of many tDCS studies has been that replication of electrode montage equates to replicating stimulation conditions. It is possible however that anatomical difference between subjects, as well as inherent inaccuracies in montage placement, could affect current flow to targeted areas. The hypothesis that stimulation of a defined brain region will be stable under small displacements was tested. Approach. Initially, we compared the total simulated current flowing through ten specific brain areas for four commonly used tDCS montages: F3-Fp2, C3-Fp2, Fp1-F4, and P3-P4 using the software tool COMETS. The effect of a slight (~1 cm in each of four directions) anode displacement on the simulated regional current density for each of the four tDCS montages was then determined. Current flow was calculated and compared through ten segmented brain areas to determine the effect of montage type and displacement. The regional currents, as well as the localised current densities, were compared with the original electrode location, for each of these new positions. Main results. Recommendations for montages that maximise stimulation current for the ten brain regions are considered. We noted that the extent to which stimulation is affected by electrode displacement varies depending on both area and montage type. The F3-Fp2 montage was found to be the least stable with up to 38% change in average current density in the left frontal lobe while the Fp1-F4 montage was found to the most stable exhibiting only 1% change when electrodes were displaced. Significance. These results indicate that even relatively small changes in stimulation electrode placement appear to result in surprisingly large

  13. Potential mechanisms supporting the value of motor cortex stimulation to treat chronic pain syndromes

    Directory of Open Access Journals (Sweden)

    Marcos Fabio DosSantos

    2016-02-01

    Full Text Available Throughout the first years of the twenty-first century, neurotechnologies such as motor cortex stimulation (MCS, transcranial magnetic stimulation (TMS and transcranial direct current stimulation (tDCS have attracted scientific attention and been considered as potential tools to centrally modulate chronic pain, especially for those conditions more difficult to manage and refractory to all types of available pharmacological therapies. Interestingly, although the role of the motor cortex in pain has not been fully clarified, it is one of the cortical areas most commonly targeted by invasive and non-invasive neuromodulation technologies. Recent studies have provided significant advances concerning the establishment of the clinical effectiveness of primary motor cortex stimulation to treat different chronic pain syndromes. Concurrently, the neuromechanisms related to each method of primary motor cortex (M1 modulation have been unveiled. In this respect, the most consistent scientific evidence originates from MCS studies, which indicate the activation of top-down controls driven by M1 stimulation. This concept has also been applied to explain M1-TMS mechanisms. Nevertheless, activation of remote areas in the brain, including cortical and subcortical structures, has been reported with both invasive and non-invasive methods and the participation of major neurotransmitters (e.g. glutamate, GABA and serotonin as well as the release of endogenous opioids has been demonstrated. In this critical review, the putative mechanisms underlying the use of motor cortex stimulation to provide relief from chronic migraine and other types of chronic pain are discussed. Emphasis is placed on the most recent scientific evidence obtained from chronic pain research studies involving MCS and non-invasive neuromodulation methods (e.g. tDCS and TMS, which are analyzed comparatively.

  14. Safety of transcranial magnetic stimulation: review of international guidelines and new findings

    Directory of Open Access Journals (Sweden)

    N. A. Suponeva

    2017-01-01

    Full Text Available Transcranial magnetic stimulation (TMS is a rapidly developing method of neuromodulation. The use of TMS has increased significantly in both research and clinical practice. This allows not only to better understand this method, but also assess possible risks and consequences for both healthy individuals and patients. In 1998 and 2009 safety, ethical considerations, and application guidelines for the use of TMS in clinical practice and research were published. These recommendations are now the basis for safe application of the method in clinical practice and research. Safety of brain stimulation includes several aspects: the prevention and treatment of adverse effects, the strategy of patient and stimulation protocols selection, as well as safety and monitoring procedures. The most common adverse effects of TMS include headache and neck pain, syncope, transient hearing impairment. The risk of epileptic seizureis extremely low and can be minimized by careful selection of patients and the use of safe stimulation protocols. Careful selection of patients is important, taking into account a large number of factors that influence the risk of adverse effects. These factors are considered in the questionnaires to identify limitations and absolute or relative contraindications to TMS. Another important part of TMS safety is the choice of the stimulation protocol and parameters such as intensity, frequency, duration of one train of stimuli, and the interstimulus interval. Currently, the recommended limits of stimulation parameters are covered in the safety guidelines. It is also necessary to follow the procedure, including the monitoring the patient's condition during TMS and the providing qualified assistance in case of adverse effects.

  15. Transcranial Magnetic Stimulation in the Treatment of Chronic Widespread Pain: A Randomized, Controlled Study

    Science.gov (United States)

    Avery, David H.; Zarkowski, Paul; Krashin, Daniel; Rho, Wang-ku; Wajdik, Chandra; Joesch, Jutta M.; Haynor, David R.; Buchwald, Dedra; Roy-Byrne, Peter

    2014-01-01

    Objective Our objective was to assess transcranial magnetic stimulation (TMS) in the treatment of chronic widespread pain (CWP). Methods Nineteen participants were randomized to two groups: one receiving active TMS (N=7) and another receiving sham stimulation (N=11) applied to the left dorsolateral prefrontal cortex. During sham stimulation, subjects heard a sound similar to the sound heard by those receiving the active treatment and received an active electrical stimulus to the scalp. The stimulation protocol consisted of 15 sessions completed within a 4-week period. Blind assessments were done at baseline and after each 5 sessions followed by blind assessments at 1 week, 1 month and 3 months after the last TMS sessions. The primary outcome variable was a pain measure, the Gracely Box Intensity Scale (BIRS). Results The percentage of subjects who guessed that they were receiving TMS was similar in the two groups. Both the TMS group and the sham group showed a statistically significant reduction in the BIRS scores from baseline during the acute phase of treatment and the follow-up phase. However, the TMS and sham groups did not differ in the change in the BIRS scores. Discussion Although some previous clinical studies and basic science studies of TMS in treating pain are promising, this study found no difference in the analgesic effect of TMS and sham stimulation. Future studies should utilize a sham condition that attempts to simulate the sound and sensation of the TMS stimulation. Stimulus location and other stimulus parameters should be explored in future studies. PMID:24755729

  16. Distinct Roles of Opioid and Dopamine Systems in Lateral Hypothalamic Intracranial Self-Stimulation.

    Science.gov (United States)

    Ide, Soichiro; Takahashi, Takehiro; Takamatsu, Yukio; Uhl, George R; Niki, Hiroaki; Sora, Ichiro; Ikeda, Kazutaka

    2017-05-01

    Opioid and dopamine systems play crucial roles in reward. Similarities and differences in the neural mechanisms of reward that are mediated by these 2 systems have remained largely unknown. Thus, in the present study, we investigated the differences in reward function in both µ-opioid receptor knockout mice and dopamine transporter knockout mice, important molecules in the opioid and dopamine systems. Mice were implanted with electrodes into the right lateral hypothalamus (l hour). Mice were then trained to put their muzzle into the hole in the head-dipping chamber for intracranial electrical stimulation, and the influences of gene knockout were assessed. Significant differences are observed between opioid and dopamine systems in reward function. µ-Opioid receptor knockout mice exhibited enhanced intracranial electrical stimulation, which induced dopamine release. They also exhibited greater motility under conditions of "despair" in both the tail suspension test and water wheel test. In contrast, dopamine transporter knockout mice maintained intracranial electrical stimulation responding even when more active efforts were required to obtain the reward. The absence of µ-opioid receptor or dopamine transporter did not lead to the absence of intracranial electrical stimulation responsiveness but rather differentially altered it. The present results in µ-opioid receptor knockout mice are consistent with the suppressive involvement of µ-opioid receptors in both positive incentive motivation associated with intracranial electrical stimulation and negative incentive motivation associated with depressive states. In contrast, the results in dopamine transporter knockout mice are consistent with the involvement of dopamine transporters in positive incentive motivation, especially its persistence. Differences in intracranial electrical stimulation in µ-opioid receptor and dopamine transporter knockout mice underscore the multidimensional nature of reward. © The Author

  17. Deep-Brain Stimulation for Basal Ganglia Disorders.

    Science.gov (United States)

    Wichmann, Thomas; Delong, Mahlon R

    2011-07-01

    The realization that medications used to treat movement disorders and psychiatric conditions of basal ganglia origin have significant shortcomings, as well as advances in the understanding of the functional organization of the brain, has led to a renaissance in functional neurosurgery, and particularly the use of deep brain stimulation (DBS). Movement disorders are now routinely being treated with DBS of 'motor' portions of the basal ganglia output nuclei, specifically the subthalamic nucleus and the internal pallidal segment. These procedures are highly effective and generally safe. Use of DBS is also being explored in the treatment of neuropsychiatric disorders, with targeting of the 'limbic' basal ganglia-thalamocortical circuitry. The results of these procedures are also encouraging, but many unanswered questions remain in this emerging field. This review summarizes the scientific rationale and practical aspects of using DBS for neurologic and neuropsychiatric disorders.

  18. Role of Sensory Stimulation in Amelioration of Obstructive Sleep Apnea

    Directory of Open Access Journals (Sweden)

    Mak Adam Daulatzai

    2011-01-01

    Full Text Available Obstructive sleep apnea (OSA, characterized by recurrent upper airway (UA collapse during sleep, is associated with significant morbidity and disorders. Polysomnogram is employed in the evaluation of OSA and apnea-hypopnea number per hour reflects severity. For normal breathing, it is essential that the collapsible UA is patent. However, obstruction of the UA is quite common in adults and infants. Normally, important reflex mechanisms defend against the UA collapse. The muscle activity of UA dilators, including the genioglossus, tensor palatini (TP, and pharyngeal constrictors, is due to the integrated mechanism of afferent sensory input → to motor function. Snoring is harsh breathing to prevent UA obstruction. Unfortunately, snoring vibrations, pharyngeal suction collapse, negative pressure, and hypoxia cause pathological perturbations including dysfunctional UA afferent sensory activity. The current paper posits that peripheral sensory stimulation paradigm, which has been shown to be efficacious in improving several neurological conditions, could be an important therapeutic strategy in OSA also.

  19. Neural dynamics during repetitive visual stimulation

    Science.gov (United States)

    Tsoneva, Tsvetomira; Garcia-Molina, Gary; Desain, Peter

    2015-12-01

    after approx. 500 ms. During the steady-state response, we observed alpha band desynchronization over occipital sites and after 500 ms also over frontal sites, while neighboring areas synchronized. The power in beta band over occipital sites increased during the stimulation period, possibly caused by increase in power at sub-harmonic frequencies of stimulation. Gamma power was also enhanced by the stimulation. Significance. These findings have direct implications on the use of RVS and SSVEPs for neural process investigation through steady-state topography, controlled entrainment of brain oscillations and BCIs. A deep understanding of SSVEP propagation in time and space and the link with ongoing brain rhythms is crucial for optimizing the typical SSVEP applications for studying, assisting, or augmenting human cognitive and sensorimotor function.

  20. Brain evoked potentials to noxious sural nerve stimulation in sciatalgic patients.

    Science.gov (United States)

    Willer, J C; De Broucker, T; Barranquero, A; Kahn, M F

    1987-07-01

    In sciatalgic patients and before any treatment, the goal of this work was to compare the amplitude of the late component (N150-P220) of the brain evoked potential (BEP) between resting pain-free conditions and a neurological induced pain produced by the Lasègue manoeuvre. The study was carried out with 8 inpatients affected with a unilateral sciatica resulting from an X-ray identified dorsal root compression from discal origin. The sural nerve was electrically stimulated at the ankle level while BEPs were recorded monopolarly from the vertex. The stimulus intensity eliciting a liminal nociceptive reflex response in a knee-flexor muscle associated with a liminal pain was selected for this study. Both normal and affected side were alternatively stimulated during several conditions of controls and of Lasègue's manoeuvres performed on the normal and on the affected side. Results show that the Lasègue manoeuvre performed on the affected side induced a significant increase in the amplitude of N150-P220; performed on the normal side, this same manoeuvre resulted in a significant decrease of the N150-P220 amplitude. These variations were observed whatever was the side (normal or affected) under sural nerve stimulation. The possible neural mechanisms of these changes and clinical implications of these data are then discussed.

  1. Effects of autonomic nerve stimulation on colorectal motility in rats

    Science.gov (United States)

    Tong, Wei Dong; Ridolfi, Timothy J.; Kosinski, Lauren; Ludwig, Kirk; Takahashi, Toku

    2010-01-01

    Background Several disease processes of the colon and rectum, including constipation and incontinence, have been associated with abnormalities of the autonomic nervous system. However, the autonomic innervation to the colon and rectum are not fully understood. The aims of this study were to investigate the effect of stimulation of vagus nerves, pelvic nerves (PN) and hypogastric nerves (HGN) on colorectal motility in rats. Methods Four strain gauge transducers were implanted on the proximal colon, mid colon, distal colon and rectum to record circular muscle contractions in rats. Electrical stimulation was administered to the efferent distal ends of the cervical vagus nerve, PN and HGN. Motility index (MI) was evaluated before and during stimulation. Key Results Electrical stimulation (5–20 Hz) of the cervical vagus elicited significant contractions in the mid colon and distal colon, whereas less pronounced contractions were observed in the proximal colon. PN stimulation elicited significant contractions in the rectum as well as the mid colon and distal colon. Atropine treatment almost completely abolished the contractions induced by vagus nerve and PN stimulation. HGN stimulation caused relaxations in the rectum, mid colon and distal colon. The relaxations in response to HGN stimulation were abolished by propranolol. Conclusions & Inferences Vagal innervation extends to the distal colon, while the PN has projections in the distribution of the rectum through the mid colon. This suggests a pattern of dual parasympathetic innervation in the left colon. Parasympathetic fibers regulate colorectal contractions via muscarinic receptors. The HGN mainly regulates colorectal relaxations via beta-adrenoceptors. PMID:20067587

  2. Repeated sessions of noninvasive brain DC stimulation is associated with motor function improvement in stroke patients.

    Science.gov (United States)

    Boggio, Paulo S; Nunes, Alice; Rigonatti, Sergio P; Nitsche, Michael A; Pascual-Leone, Alvaro; Fregni, Felipe

    2007-01-01

    Recent evidence has suggested that a simple technique of noninvasive brain stimulation - transcranial direct current stimulation (tDCS) - is associated with a significant motor function improvement in stroke patients. We tested the motor performance improvement in stroke patients following 4 weekly sessions of sham, anodal- and cathodal tDCS (experiment 1) and the effects of 5 consecutive daily sessions of cathodal tDCS (experiment 2). A blinded rater evaluated motor function using the Jebsen-Taylor Hand Function Test. There was a significant main effect of stimulation condition (p=0.009) in experiment 1. Furthermore there was a significant motor function improvement after either cathodal tDCS of the unaffected hemisphere (p=0.016) or anodal tDCS of the affected hemisphere (p=0.046) when compared to sham tDCS. There was no cumulative effect associated with weekly sessions of tDCS, however consecutive daily sessions of tDCS (experiment 2) were associated with a significant effect on time (pmotor function improvement in stroke patients; and support that consecutive daily sessions of tDCS might increase its behavioral effects. Because the technique of tDCS is simple, safe and non-expensive; our findings support further research on the use of this technique for the rehabilitation of patients with stroke.

  3. EOR by stimulated microflora

    Energy Technology Data Exchange (ETDEWEB)

    Svarovskaya, L.I.; Altunina, L.K.; Rozhenkova, Z.A.; Bulavin, V.D. [Institute of Petroleum Chemistry, Tomsk (Russian Federation)

    1995-12-31

    A combined microbiological and physico-chemical method for EOR has been developed for flooded West Siberia oil fields with formation temperature of 45{degrees}-95{degrees}C (318-365K). Formation water includes rich and various biocenoses numbering up to 2 x 10{sup 7} cells per ml. Representatives of genera, i.e, Pseudomonas, Bacillus, Actinomyces, Micrococcus, Mycobacterium, Sarcina, etc. were found to be the most widely distributed microorganisms. The method is based on injection of systems exhibiting high oil displacing capacity and at the same time being an additional nitrous nutrient for endemic populations of microorganisms. Their injection into formation water favors biomass growth by 4-6 orders and promotes syntheses of biosurfactants, biopolymers, acids, etc., and gaseous products. The features of residual oil displacement have been studied on laboratory models using a combined microbiological and physico-chemical method. A curve for the yield of residual oil is presented by two peaks. The first peak is stipulated by the washing action of oil displacement system, and the second one by the effect of metabolites produced at stimulation of biogenic processes. Oil displacement index increases by 15%-30%.

  4. Electrode position markedly affects knee torque in tetanic, stimulated contractions.

    Science.gov (United States)

    Vieira, Taian M; Potenza, Paolo; Gastaldi, Laura; Botter, Alberto

    2016-02-01

    The purpose of this study was to investigate how much the distance between stimulation electrodes affects the knee extension torque in tetanic, electrically elicited contractions. Current pulses of progressively larger amplitude, from 0 mA to maximally tolerated intensities, were delivered at 20 pps to the vastus medialis, rectus femoris and vastus lateralis muscles of ten, healthy male subjects. Four inter-electrode distances were tested: 32.5% (L1), 45.0% (L2), 57.5% (L3) and 70% (L4) of the distance between the patella apex and the anterior superior iliac spine. The maximal knee extension torque and the current leading to the maximal torque were measured and compared between electrode configurations. The maximal current tolerated by each participant ranged from 60 to 100 mA and did not depend on the inter-electrode distance. The maximal knee extension torque elicited did not differ between L3 and L4 (P = 0.15) but, for both conditions, knee torque was significantly greater than for L1 and L2 (P torque elicited for L3 and L4 was two to three times greater than that obtained for L1 and L2. The current leading to maximal torque was not as sensitive to inter-electrode distance. Except for L1 current intensity did not change with electrode configuration (P > 0.16). Key results presented here revealed that for a given stimulation intensity, knee extension torque increased dramatically with the distance between electrodes. The distance between electrodes seems therefore to critically affect knee torque, with potential implication for optimising exercise protocols based on electrical stimulation.

  5. Benfotiamine attenuates inflammatory response in LPS stimulated BV-2 microglia.

    Science.gov (United States)

    Bozic, Iva; Savic, Danijela; Laketa, Danijela; Bjelobaba, Ivana; Milenkovic, Ivan; Pekovic, Sanja; Nedeljkovic, Nadezda; Lavrnja, Irena

    2015-01-01

    Microglial cells are resident immune cells of the central nervous system (CNS), recognized as key elements in the regulation of neural homeostasis and the response to injury and repair. As excessive activation of microglia may lead to neurodegeneration, therapeutic strategies targeting its inhibition were shown to improve treatment of most neurodegenerative diseases. Benfotiamine is a synthetic vitamin B1 (thiamine) derivate exerting potentially anti-inflammatory effects. Despite the encouraging results regarding benfotiamine potential to alleviate diabetic microangiopathy, neuropathy and other oxidative stress-induced pathological conditions, its activities and cellular mechanisms during microglial activation have yet to be elucidated. In the present study, the anti-inflammatory effects of benfotiamine were investigated in lipopolysaccharide (LPS)-stimulated murine BV-2 microglia. We determined that benfotiamine remodels activated microglia to acquire the shape that is characteristic of non-stimulated BV-2 cells. In addition, benfotiamine significantly decreased production of pro-inflammatory mediators such as inducible form of nitric oxide synthase (iNOS) and NO; cyclooxygenase-2 (COX-2), heat-shock protein 70 (Hsp70), tumor necrosis factor alpha α (TNF-α), interleukin-6 (IL-6), whereas it increased anti-inflammatory interleukin-10 (IL-10) production in LPS stimulated BV-2 microglia. Moreover, benfotiamine suppressed the phosphorylation of extracellular signal-regulated kinases 1/2 (ERK1/2), c-Jun N-terminal kinases (JNK) and protein kinase B Akt/PKB. Treatment with specific inhibitors revealed that benfotiamine-mediated suppression of NO production was via JNK1/2 and Akt pathway, while the cytokine suppression includes ERK1/2, JNK1/2 and Akt pathways. Finally, the potentially protective effect is mediated by the suppression of translocation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in the nucleus. Therefore, benfotiamine may

  6. Proinflammatory mediators stimulate neutrophil-directed angiogenesis.

    LENUS (Irish Health Repository)

    McCourt, M

    2012-02-03

    BACKGROUND: Vascular endothelial growth factor (VEGF; vascular permeability factor) is one of the most potent proangiogenic cytokines, and it plays a central role in mediating the process of angiogenesis or new blood vessel formation. Neutrophils (PMNs) recently have been shown to produce VEGF. HYPOTHESIS: The acute inflammatory response is a potent stimulus for PMN-directed angiogenesis. METHODS: Neutrophils were isolated from healthy volunteers and stimulated with lipopolysaccharide (LPS), tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), and anti-human Fas monoclonal antibody. Culture supernatants were assayed for VEGF using enzyme-linked immunosorbent assays. Culture supernatants from LPS- and TNF-alpha-stimulated PMNs were then added to human umbilical vein endothelial cells and human microvessel endothelial cells and assessed for endothelial cell proliferation using 5-bromodeoxyuridine labeling. Tubule formation was also assessed on MATRIGEL basement membrane matrix. Neutrophils were lysed to measure total VEGF release, and VEGF expression was detected using Western blot analysis. RESULTS: Lipopolysaccharide and TNF-alpha stimulation resulted in significantly increased release of PMN VEGF (532+\\/-49 and 484+\\/-80 pg\\/mL, respectively; for all, presented as mean +\\/- SEM) compared with control experiments (32+\\/-4 pg\\/mL). Interleukin 6 and Fas had no effect. Culture supernatants from LPS- and TNF-alpha-stimulated PMNs also resulted in significant increases (P<.005) in macrovascular and microvascular endothelial cell proliferation and tubule formation. Adding anti-human VEGF-neutralizing polyclonal antibody to stimulated PMN supernatant inhibited these effects. Total VEGF release following cell lysis and Western blot analysis suggests that the VEGF is released from an intracellular store. CONCLUSION: Activated human PMNs are directly angiogenic by releasing VEGF, and this has important implications for inflammation, capillary leak syndrome

  7. Stimulating Language: Insights from TMS

    Science.gov (United States)

    Devlin, Joseph T.; Watkins, Kate E.

    2007-01-01

    Fifteen years ago, Pascual-Leone and colleagues used transcranial magnetic stimulation (TMS) to investigate speech production in pre-surgical epilepsy patients and in doing so, introduced a novel tool into language research. TMS can be used to non-invasively stimulate a specific cortical region and transiently disrupt information processing. These…

  8. Vertex Stimulation as a Control Site for Transcranial Magnetic Stimulation: A Concurrent TMS/fMRI Study.

    Science.gov (United States)

    Jung, JeYoung; Bungert, Andreas; Bowtell, Richard; Jackson, Stephen R

    2016-01-01

    A common control condition for transcranial magnetic stimulation (TMS) studies is to apply stimulation at the vertex. An assumption of vertex stimulation is that it has relatively little influence over on-going brain processes involved in most experimental tasks, however there has been little attempt to measure neural changes linked to vertex TMS. Here we directly test this assumption by using a concurrent TMS/fMRI paradigm in which we investigate fMRI blood-oxygenation-level-dependent (BOLD) signal changes across the whole brain linked to vertex stimulation. Thirty-two healthy participants to part in this study. Twenty-one were stimulated at the vertex, at 120% of resting motor threshold (RMT), with short bursts of 1 Hz TMS, while functional magnetic resonance imaging (fMRI) BOLD images were acquired. As a control condition, we delivered TMS pulses over the left primary motor cortex using identical parameters to 11 other participants. Vertex stimulation did not evoke increased BOLD activation at the stimulated site. By contrast we observed widespread BOLD deactivations across the brain, including regions within the default mode network (DMN). To examine the effects of vertex stimulation a functional connectivity analysis was conducted. The results demonstrated that stimulating the vertex with suprathreshold TMS reduced neural activity in brain regions related to the DMN but did not influence the functional connectivity of this network. Our findings provide brain imaging evidence in support of the use of vertex simulation as a control condition in TMS but confirm that vertex TMS induces regional widespread decreases in BOLD activation. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Intensity dependent effects of transcranial direct current stimulation on corticospinal excitability in chronic spinal cord injury.

    Science.gov (United States)

    Murray, Lynda M; Edwards, Dylan J; Ruffini, Giulio; Labar, Douglas; Stampas, Argyrios; Pascual-Leone, Alvaro; Cortes, Mar

    2015-04-01

    To investigate the effects of anodal transcranial direct current stimulation (a-tDCS) intensity on corticospinal excitability and affected muscle activation in individuals with chronic spinal cord injury (SCI). Single-blind, randomized, sham-controlled, crossover study. Medical research institute and rehabilitation hospital. Volunteers (N = 9) with chronic SCI and motor dysfunction in wrist extensor muscles. Three single session exposures to 20 minutes of a-tDCS (anode over the extensor carpi radialis [ECR] muscle representation on the left primary motor cortex, cathode over the right supraorbital area) using 1 mA, 2 mA, or sham stimulation, delivered at rest, with at least 1 week between sessions. Corticospinal excitability was assessed with motor-evoked potentials (MEPs) from the ECR muscle using surface electromyography after transcranial magnetic stimulation. Changes in spinal excitability, sensory threshold, and muscle strength were also investigated. Mean MEP amplitude significantly increased by approximately 40% immediately after 2mA a-tDCS (pre: 0.36 ± 0.1 mV; post: 0.47 ± 0.11 mV; P = .001), but not with 1 mA or sham. Maximal voluntary contraction measures remained unaltered across all conditions. Sensory threshold significantly decreased over time after 1mA (P = .002) and 2mA (P = .039) a-tDCS and did not change with sham. F-wave persistence showed a nonsignificant trend for increase (pre: 32% ± 12%; post: 41% ± 10%; follow-up: 46% ± 12%) after 2 mA stimulation. No adverse effects were reported with any of the experimental conditions. The a-tDCS can transiently raise corticospinal excitability to affected muscles in patients with chronic SCI after 2 mA stimulation. Sensory perception can improve with both 1 and 2 mA stimulation. This study gives support to the safe and effective use of a-tDCS using small electrodes in patients with SCI and highlights the importance of stimulation intensity. Copyright © 2015 American Congress of Rehabilitation

  10. Differential effects of bihemispheric and unihemispheric transcranial direct current stimulation in young and elderly adults in verbal learning.

    Science.gov (United States)

    Fiori, Valentina; Nitsche, Michael; Iasevoli, Luigi; Cucuzza, Gabriella; Caltagirone, Carlo; Marangolo, Paola

    2017-03-15

    For the past few years, the potential of transcranial direct current stimulation (tDCS) for the treatment of several pathologies has been investigated. In the language domain, several studies, in healthy and brain-damaged populations, have already shown that tDCS is effective in enhancing naming, repetition and semantic word generation. In those studies, different tDCS electrode configurations have been tested, however, a direct comparison between different montages in verbal learning has never been conducted. In this study, we aimed to explore the impact of bihemispheric and unihemispheric tDCS on verbal learning task performance in two groups (young vs. elderly). Fifteen healthy volunteers participated per group. Each participant received three stimulation conditions: unihemispheric anodal tDCS over the left temporal area, bihemispheric tDCS over the left (anodal) and right (cathodal) temporal areas and a sham condition. During active stimulation, tDCS (20min, 2mA) was applied while each participant learned twenty pseudowords (arbitrarily assigned to corresponding pictures). No significant differences were found between the three conditions for the young group with regard to accuracy and vocal reaction times. In contrast, in the elderly group, real stimulation improved performance compared to sham but bihemispheric tDCS was more efficient than unilateral stimulation. These results suggest that bihemispheric stimulation is more effective in improving language learning but this effect is age-dependent. The hypothesis is advanced that cortical changes in the course of aging might differentially impact on tDCS efficacy on behavioral performance. These data may also have implications for treatment of stroke patients with language impairment. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Ultra-nanocrystalline diamond electrodes: optimization towards neural stimulation applications.

    Science.gov (United States)

    Garrett, David J; Ganesan, Kumaravelu; Stacey, Alastair; Fox, Kate; Meffin, Hamish; Prawer, Steven

    2012-02-01

    Diamond is well known to possess many favourable qualities for implantation into living tissue including biocompatibility, biostability, and for some applications hardness. However, conducting diamond has not, to date, been exploited in neural stimulation electrodes due to very low electrochemical double layer capacitance values that have been previously reported. Here we present electrochemical characterization of ultra-nanocrystalline diamond electrodes grown in the presence of nitrogen (N-UNCD) that exhibit charge injection capacity values as high as 163 µC cm(-2) indicating that N-UNCD is a viable material for microelectrode fabrication. Furthermore, we show that the maximum charge injection of N-UNCD can be increased by tailoring growth conditions and by subsequent electrochemical activation. For applications requiring yet higher charge injection, we show that N-UNCD electrodes can be readily metalized with platinum or iridium, further increasing charge injection capacity. Using such materials an implantable neural stimulation device fabricated from a single piece of bio-permanent material becomes feasible. This has significant advantages in terms of the physical stability and hermeticity of a long-term bionic implant.

  12. Relaxation oscillations in stimulated Raman scattering

    International Nuclear Information System (INIS)

    Kachen, G.I.; Lowdermilk, W.H.

    1977-01-01

    Light pulses created by stimulated Raman scattering having been found to exhibit a complex time dependence which resembles relaxation oscillations. A focused laser pulse generated both forward and backward Raman emissions which appeared as a series of pulses with durations much shorter than the incident laser pulse. Time dependence of the Raman emission was observed directly by use of a streak camera. The number of observed pulses increased with the intensity of the incident pulse, while separation of the pulses in time depended on the length of the focal region. Beam focusing was incorporated in the coupled wave equations for stimulated Raman scattering. These rate equations were then solved numerically, and the results are in good qualitative agreement with the experimental observations. The short Raman pulses are created by a process associated with depletion of the incident laser pulse. This process occurs under a broad range of conditions

  13. Electrical stimulation in treatment of pharyngolaryngeal dysfunctions.

    Science.gov (United States)

    Miller, Simone; Jungheim, Michael; Kühn, Daniela; Ptok, Martin

    2013-01-01

    Neuromuscular electrical stimulation (NMES) has been proposed in the treatment of laryngopharyngeal dysfunctions (dysphonia, dyspnoea, dysphagia) for more than 40 years. Several studies have investigated possible therapeutic effects. Some researchers described favourable results, whereas others did not find relevant benefits. This article aims to review available studies to give an overview regarding the current state of knowledge. We conducted a selective literature search using PubMed. In total, 356 papers were identified: 6 case reports, 11 reviews, 43 prospective clinical trials and 3 retrospective trials were found. Due to different stimulation protocols, electrode positioning and various underlying pathological conditions, summarizing the present studies appears to be difficult. However, there is evidence that NMES is a valuable adjunct in patients with dysphagia and in patients with vocal fold paresis. Nevertheless, more empirical data is needed to fully understand the benefits provided by NMES. Further research suggestions are put forward. © 2013 S. Karger AG, Basel.

  14. Effects of Anodal Transcranial Direct Current Stimulation on Visually Guided Learning of Grip Force Control

    Directory of Open Access Journals (Sweden)

    Tamas Minarik

    2015-03-01

    Full Text Available Anodal transcranial Direct Current Stimulation (tDCS has been shown to be an effective non-invasive brain stimulation method for improving cognitive and motor functioning in patients with neurological deficits. tDCS over motor cortex (M1, for instance, facilitates motor learning in stroke patients. However, the literature on anodal tDCS effects on motor learning in healthy participants is inconclusive, and the effects of tDCS on visuo-motor integration are not well understood. In the present study we examined whether tDCS over the contralateral motor cortex enhances learning of grip-force output in a visually guided feedback task in young and neurologically healthy volunteers. Twenty minutes of 1 mA anodal tDCS were applied over the primary motor cortex (M1 contralateral to the dominant (right hand, during the first half of a 40 min power-grip task. This task required the control of a visual signal by modulating the strength of the power-grip for six seconds per trial. Each participant completed a two-session sham-controlled crossover protocol. The stimulation conditions were counterbalanced across participants and the sessions were one week apart. Performance measures comprised time-on-target and target-deviation, and were calculated for the periods of stimulation (or sham and during the afterphase respectively. Statistical analyses revealed significant performance improvements over the stimulation and the afterphase, but this learning effect was not modulated by tDCS condition. This suggests that the form of visuomotor learning taking place in the present task was not sensitive to neurostimulation. These null effects, together with similar reports for other types of motor tasks, lead to the proposition that tDCS facilitation of motor learning might be restricted to cases or situations where the motor system is challenged, such as motor deficits, advanced age, or very high task demand.

  15. Excitability of the motor system: A transcranial magnetic stimulation study on singing and speaking.

    Science.gov (United States)

    Royal, Isabelle; Lidji, Pascale; Théoret, Hugo; Russo, Frank A; Peretz, Isabelle

    2015-08-01

    The perception of movements is associated with increased activity in the human motor cortex, which in turn may underlie our ability to understand actions, as it may be implicated in the recognition, understanding and imitation of actions. Here, we investigated the involvement and lateralization of the primary motor cortex (M1) in the perception of singing and speech. Transcranial magnetic stimulation (TMS) was applied independently for both hemispheres over the mouth representation of the motor cortex in healthy participants while they watched 4-s audiovisual excerpts of singers producing a 2-note ascending interval (singing condition) or 4-s audiovisual excerpts of a person explaining a proverb (speech condition). Subjects were instructed to determine whether a sung interval/written proverb, matched a written interval/proverb. During both tasks, motor evoked potentials (MEPs) were recorded from the contralateral mouth muscle (orbicularis oris) of the stimulated motor cortex compared to a control task. Moreover, to investigate the time course of motor activation, TMS pulses were randomly delivered at 7 different time points (ranging from 500 to 3500 ms after stimulus onset). Results show that stimulation of the right hemisphere had a similar effect on the MEPs for both the singing and speech perception tasks, whereas stimulation of the left hemisphere significantly differed in the speech perception task compared to the singing perception task. Furthermore, analysis of the MEPs in the singing task revealed that they decreased for small musical intervals, but increased for large musical intervals, regardless of which hemisphere was stimulated. Overall, these results suggest a dissociation between the lateralization of M1 activity for speech perception and for singing perception, and that in the latter case its activity can be modulated by musical parameters such as the size of a musical interval. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Are Participants Aware of the Type and Intensity of Transcranial Direct Current Stimulation?

    Directory of Open Access Journals (Sweden)

    Matthew F Tang

    Full Text Available Transcranial direct current stimulation (tDCS is commonly used to alter cortical excitability but no experimental study has yet determined whether human participants are able to distinguish between the different types (anodal, cathodal, and sham of stimulation. If they can then they are not blind to experimental conditions. We determined whether participants could identify different types of stimulation (anodal, cathodal, and sham and current strengths after experiencing the sensations of stimulation during current onset and offset (which are associated with the most intense sensations in Experiment 1 and also with a prolonged period of stimulation in Experiment 2. We first familiarized participants with anodal, cathodal, and sham stimulation at both 1 and 2 mA over either primary motor or visual cortex while their sensitivity to small changes in visual stimuli was assessed. The different stimulation types were then applied for a short (Experiment 1 or extended (Experiment 2 period with participants indicating the type and strength of the stimulation on the basis of the evoked sensations. Participants were able to identify the intensity of stimulation with shorter, but not longer periods, of stimulation at better than chance levels but identification of the different stimulation types was at chance levels. This result suggests that even after exposing participants to stimulation, and ensuring they are fully aware of the existence of a sham condition, they are unable to identify the type of stimulation from transient changes in stimulation intensity or from more prolonged stimulation. Thus participants are able to identify intensity of stimulation but not the type of stimulation.

  17. Polarity-Dependent Misperception of Subjective Visual Vertical during and after Transcranial Direct Current Stimulation (tDCS).

    Science.gov (United States)

    Santos-Pontelli, Taiza E G; Rimoli, Brunna P; Favoretto, Diandra B; Mazin, Suleimy C; Truong, Dennis Q; Leite, Joao P; Pontes-Neto, Octavio M; Babyar, Suzanne R; Reding, Michael; Bikson, Marom; Edwards, Dylan J

    2016-01-01

    Pathologic tilt of subjective visual vertical (SVV) frequently has adverse functional consequences for patients with stroke and vestibular disorders. Repetitive transcranial magnetic stimulation (rTMS) of the supramarginal gyrus can produce a transitory tilt on SVV in healthy subjects. However, the effect of transcranial direct current stimulation (tDCS) on SVV has never been systematically studied. We investigated whether bilateral tDCS over the temporal-parietal region could result in both online and offline SVV misperception in healthy subjects. In a randomized, sham-controlled, single-blind crossover pilot study, thirteen healthy subjects performed tests of SVV before, during and after the tDCS applied over the temporal-parietal region in three conditions used on different days: right anode/left cathode; right cathode/left anode; and sham. Subjects were blind to the tDCS conditions. Montage-specific current flow patterns were investigated using computational models. SVV was significantly displaced towards the anode during both active stimulation conditions when compared to sham condition. Immediately after both active conditions, there were rebound effects. Longer lasting after-effects towards the anode occurred only in the right cathode/left anode condition. Current flow models predicted the stimulation of temporal-parietal regions under the electrodes and deep clusters in the posterior limb of the internal capsule. The present findings indicate that tDCS over the temporal-parietal region can significantly alter human SVV perception. This tDCS approach may be a potential clinical tool for the treatment of SVV misperception in neurological patients.

  18. Gamma-radiation-induced chromosal aberration in human lymphocytes: dose-rate effects in stimulated and non-stimulated cells

    International Nuclear Information System (INIS)

    Liniecki, J.; Bajerska, A.; Wyszynska, K.; Cisowska, B.

    1977-01-01

    Stimulated and non-stimulated human peripheral blood lymphocytes were irradiated acutely and chronically, over 24 h. Dose-effect relationships for dicentric chromosomes were established and various models were fitted to the data. At prolonged irradiations, the yield decreased in basic agreement with the linear-quadratic model of aberration induction. Dose-protraction experiments on PHA + and PHA - lymphocytes, irradiated under various conditions of oxygenation and suspension (culture medium, whole blood) showed that the rejoining time increased from about 3 h in non-stimulated cells to about 10 h after PHA stimulation, and that this retarded rejoining was most likely due to blastic transformation itself and not to other conditions of irradiation

  19. Gamma radiation induced chromosal aberration in human lymphocytes: dose-rate effects in stimulated and non-stimulated cells

    Energy Technology Data Exchange (ETDEWEB)

    Liniecki, J; Bajerska, A; Wyszynska, K [School of Medicine, Lodz (Poland). Div. of Nuclear Medicine and Radiobiology. Medical Research Center; Cisowska, B [Copernicus Municipal Hospital, Lodz (Poland). Oncology Center. Radiotherapy Dept.

    1977-05-01

    Stimulated and non-stimulated human peripheral blood lymphocytes were irradiated acutely and chronically, over 24 h. Dose-effect relationships for dicentric chromosomes were established and various models were fitted to the data. At prolonged irradiations, the yield decreased in basic agreement with the linear-quadratic model of aberration induction. Dose-protraction experiments on PHA/sup +/ and PHA/sup -/ lymphocytes, irradiated under various conditions of oxygenation and suspension (culture medium, whole blood) showed that the rejoining time increased from about 3 h in non-stimulated cells to about 10 h after PHA stimulation, and that this retarded rejoining was most likely due to blastic transformation itself and not to other conditions of irradiation.

  20. Ipsilateral masking between acoustic and electric stimulations.

    Science.gov (United States)

    Lin, Payton; Turner, Christopher W; Gantz, Bruce J; Djalilian, Hamid R; Zeng, Fan-Gang

    2011-08-01

    Residual acoustic hearing can be preserved in the same ear following cochlear implantation with minimally traumatic surgical techniques and short-electrode arrays. The combined electric-acoustic stimulation significantly improves cochlear implant performance, particularly speech recognition in noise. The present study measures simultaneous masking by electric pulses on acoustic pure tones, or vice versa, to investigate electric-acoustic interactions and their underlying psychophysical mechanisms. Six subjects, with acoustic hearing preserved at low frequencies in their implanted ear, participated in the study. One subject had a fully inserted 24 mm Nucleus Freedom array and five subjects had Iowa/Nucleus hybrid implants that were only 10 mm in length. Electric masking data of the long-electrode subject showed that stimulation from the most apical electrodes produced threshold elevations over 10 dB for 500, 625, and 750 Hz probe tones, but no elevation for 125 and 250 Hz tones. On the contrary, electric stimulation did not produce any electric masking in the short-electrode subjects. In the acoustic masking experiment, 125-750 Hz pure tones were used to acoustically mask electric stimulation. The acoustic masking results showed that, independent of pure tone frequency, both long- and short-electrode subjects showed threshold elevations at apical and basal electrodes. The present results can be interpreted in terms of underlying physiological mechanisms related to either place-dependent peripheral masking or place-independent central masking.

  1. Galvanic vestibular stimulation speeds visual memory recall.

    Science.gov (United States)

    Wilkinson, David; Nicholls, Sophie; Pattenden, Charlotte; Kilduff, Patrick; Milberg, William

    2008-08-01

    The experiments of Alessandro Volta were amongst the first to indicate that visuo-spatial function can be altered by stimulating the vestibular nerves with galvanic current. Until recently, the beneficial effects of the procedure were masked by the high levels of electrical current applied, which induced nystagmus-related gaze deviation and spatial disorientation. However, several neuropsychological studies have shown that much weaker, imperceptible currents that do not elicit unpleasant side-effects can help overcome visual loss after stroke. Here, we show that visual processing in neurologically healthy individuals can also benefit from galvanic vestibular stimulation. Participants first learnt the names of eight unfamiliar faces and then after a short delay, answered questions from memory about how pairs of these faces differed. Mean correct reaction times were significantly shorter when sub-sensory, noise-enhanced anodal stimulation was administered to the left mastoid, compared to when no stimulation was administered at all. This advantage occurred with no loss in response accuracy, and raises the possibility that the procedure may constitute a more general form of cognitive enhancement.

  2. Targeted transtracheal stimulation for vocal fold closure.

    Science.gov (United States)

    Hadley, Aaron J; Thompson, Paul; Kolb, Ilya; Hahn, Elizabeth C; Tyler, Dustin J

    2014-06-01

    Paralysis of the structures in the head and neck due to stroke or other neurological disorder often causes dysphagia (difficulty in swallowing). Patients with dysphagia have a significantly higher incidence of aspiration pneumonia and death. The recurrent laryngeal nerve (RLN), which innervates the intrinsic laryngeal muscles that control the vocal folds, travels superiorly in parallel to the trachea in the tracheoesophageal groove. This study tests the hypothesis that functional electrical stimulation (FES) applied via transtracheal electrodes can produce controlled vocal fold adduction. Bipolar electrodes were placed at 15° intervals around the interior mucosal surface of the canine trachea, and current was applied to the tissue while electromyography (EMG) from the intrinsic laryngeal muscles and vocal fold movement visualization via laryngoscopy were recorded. The lowest EMG thresholds were found at an average location of 100° to the left of the ventral midsagittal line and 128° to the right. A rotatable pair of bipolar electrodes spaced 230° apart were able to stimulate bilaterally both RLNs in every subject. Laryngoscopy showed complete glottal closure with transtracheal stimulation in six of the eight subjects, and this closure was maintained under simultaneous FES-induced laryngeal elevation. Transtracheal stimulation is an effective tool for minimally invasive application of FES to induce vocal fold adduction, providing an alternative mechanism to study airway protection.

  3. Human transient response under local thermal stimulation

    Directory of Open Access Journals (Sweden)

    Wang Lijuan

    2017-01-01

    Full Text Available Human body can operate physiological thermoregulation system when it is exposed to cold or hot environment. Whether it can do the same work when a local part of body is stimulated by different temperatures? The objective of this paper is to prove it. Twelve subjects are recruited to participate in this experiment. After stabilizing in a comfort environment, their palms are stimulated by a pouch of 39, 36, 33, 30, and 27°C. Subject’s skin temperature, heart rate, heat flux of skin, and thermal sensation are recorded. The results indicate that when local part is suffering from harsh temperature, the whole body is doing physiological thermoregulation. Besides, when the local part is stimulated by high temperature and its thermal sensation is warm, the thermal sensation of whole body can be neutral. What is more, human body is more sensitive to cool stimulation than to warm one. The conclusions are significant to reveal and make full use of physiological thermoregulation.

  4. Bubble nonlinear dynamics and stimulated scattering process

    Science.gov (United States)

    Jie, Shi; De-Sen, Yang; Sheng-Guo, Shi; Bo, Hu; Hao-Yang, Zhang; Shi-Yong, Hu

    2016-02-01

    A complete understanding of the bubble dynamics is deemed necessary in order to achieve their full potential applications in industry and medicine. For this purpose it is first needed to expand our knowledge of a single bubble behavior under different possible conditions including the frequency and pressure variations of the sound field. In addition, stimulated scattering of sound on a bubble is a special effect in sound field, and its characteristics are associated with bubble oscillation mode. A bubble in liquid can be considered as a representative example of nonlinear dynamical system theory with its resonance, and its dynamics characteristics can be described by the Keller-Miksis equation. The nonlinear dynamics of an acoustically excited gas bubble in water is investigated by using theoretical and numerical analysis methods. Our results show its strongly nonlinear behavior with respect to the pressure amplitude and excitation frequency as the control parameters, and give an intuitive insight into stimulated sound scattering on a bubble. It is seen that the stimulated sound scattering is different from common dynamical behaviors, such as bifurcation and chaos, which is the result of the nonlinear resonance of a bubble under the excitation of a high amplitude acoustic sound wave essentially. The numerical analysis results show that the threshold of stimulated sound scattering is smaller than those of bifurcation and chaos in the common condition. Project supported by the Program for Changjiang Scholars and Innovative Research Team in University, China (Grant No. IRT1228) and the Young Scientists Fund of the National Natural Science Foundation of China (Grant Nos. 11204050 and 11204049).

  5. Evaluation of focused multipolar stimulation for cochlear implants: a preclinical safety study

    Science.gov (United States)

    Shepherd, Robert K.; Wise, Andrew K.; Enke, Ya Lang; Carter, Paul M.; Fallon, James B.

    2017-08-01

    Objective. Cochlear implants (CIs) have a limited number of independent stimulation channels due to the highly conductive nature of the fluid-filled cochlea. Attempts to develop highly focused stimulation to improve speech perception in CI users includes the use of simultaneous stimulation via multiple current sources. Focused multipolar (FMP) stimulation is an example of this approach and has been shown to reduce interaction between stimulating channels. However, compared with conventional biphasic current pulses generated from a single current source, FMP is a complex stimulus that includes extended periods of stimulation before charge recovery is achieved, raising questions on whether chronic stimulation with this strategy is safe. The present study evaluated the long-term safety of intracochlear stimulation using FMP in a preclinical animal model of profound deafness. Approach. Six cats were bilaterally implanted with scala tympani electrode arrays two months after deafening, and received continuous unilateral FMP stimulation at levels that evoked a behavioural response for periods of up to 182 d. Electrode impedance, electrically-evoked compound action potentials (ECAPs) and auditory brainstem responses (EABRs) were monitored periodically over the course of the stimulation program from both the stimulated and contralateral control cochleae. On completion of the stimulation program cochleae were examined histologically and the electrode arrays were evaluated for evidence of platinum (Pt) corrosion. Main results. There was no significant difference in electrode impedance between control and chronically stimulated electrodes following long-term FMP stimulation. Moreover, there was no significant difference between ECAP and EABR thresholds evoked from control or stimulated cochleae at either the onset of stimulation or at completion of the stimulation program. Chronic FMP stimulation had no effect on spiral ganglion neuron (SGN) survival when compared with

  6. A simple miniature device for wireless stimulation of neural circuits in small behaving animals.

    Science.gov (United States)

    Zhang, Yisi; Langford, Bruce; Kozhevnikov, Alexay

    2011-10-30

    The use of wireless neural stimulation devices offers significant advantages for neural stimulation experiments in behaving animals. We demonstrate a simple, low-cost and extremely lightweight wireless neural stimulation device which is made from off-the-shelf components. The device has low power consumption and does not require a high-power RF preamplifier. Neural stimulation can be carried out in either a voltage source mode or a current source mode. Using the device, we carry out wireless stimulation in the premotor brain area HVC of a songbird and demonstrate that such stimulation causes rapid perturbations of the acoustic structure of the song. Published by Elsevier B.V.

  7. Prefrontal cortex stimulation does not affect emotional bias, but may slow emotion identification.

    Science.gov (United States)

    Nord, Camilla L; Forster, Sophie; Halahakoon, D Chamith; Penton-Voak, Ian S; Munafò, Marcus R; Roiser, Jonathan P

    2017-05-01

    Transcranial direct current stimulation (tDCS) has recently garnered attention as a putative depression treatment. However, the cognitive mechanisms by which it exerts an antidepressant effect are unclear: tDCS may directly alter 'hot' emotional processing biases, or alleviate depression through changes in 'cold' (non-emotional) cognitive function. Here, 75 healthy participants performed a facial emotion identification task during 20 minutes of anodal or sham tDCS over the left dorsolateral prefrontal cortex (DLPFC) in a double-blind, within-subject crossover design. A subset of 31 participants additionally completed a task measuring attentional distraction during stimulation. Compared to sham stimulation, anodal tDCS of the left DLPFC resulted in an increase in response latency across all emotional conditions. Bayesian analysis showed definitively that tDCS exerted no emotion-dependent effect on behaviour. Thus, we demonstrate that anodal tDCS produces a general, rather than an emotion-specific, effect. We also report a preliminary finding in the subset of participants who completed the distractibility task: increased distractibility during active stimulation correlated significantly with the degree to which tDCS slowed emotion identification. Our results provide insight into the possible mechanisms by which DLPFC tDCS may treat symptoms of depression, suggesting that it may not alter emotional biases, but instead may affect 'cold' cognitive processes. © The Author (2017). Published by Oxford University Press.

  8. Is effect of transcranial direct current stimulation on visuomotor coordination dependent on task difficulty?

    Directory of Open Access Journals (Sweden)

    Yong Hyun Kwon

    2015-01-01

    Full Text Available Transcranial direct current stimulation (tDCS, an emerging technique for non-invasive brain stimulation, is increasingly used to induce changes in cortical excitability and modulate motor behavior, especially for upper limbs. The purpose of this study was to investigate the effects of tDCS of the primary motor cortex on visuomotor coordination based on three levels of task difficulty in healthy subjects. Thirty-eight healthy participants underwent real tDCS or sham tDCS. Using a single-blind, sham-controlled crossover design, tDCS was applied to the primary motor cortex. For real tDCS conditions, tDCS intensity was 1 mA while stimulation was applied for 15 minutes. For the sham tDCS, electrodes were placed in the same position, but the stimulator was turned off after 5 seconds. Visuomotor tracking task, consisting of three levels (levels 1, 2, 3 of difficulty with higher level indicating greater difficulty, was performed before and after tDCS application. At level 2, real tDCS of the primary motor cortex improved the accurate index compared to the sham tDCS. However, at levels 1 and 3, the accurate index was not significantly increased after real tDCS compared to the sham tDCS. These findings suggest that tasks of moderate difficulty may improve visuomotor coordination in healthy subjects when tDCS is applied compared with easier or more difficult tasks.

  9. Targeted therapies using electrical and magnetic neural stimulation for the treatment of chronic pain in spinal cord injury.

    Science.gov (United States)

    Moreno-Duarte, Ingrid; Morse, Leslie R; Alam, Mahtab; Bikson, Marom; Zafonte, Ross; Fregni, Felipe

    2014-01-15

    Chronic neuropathic pain is one of the most common and disabling symptoms in individuals with spinal cord injury (SCI). Over two-thirds of subjects with SCI suffer from chronic pain influencing quality of life, rehabilitation, and recovery. Given the refractoriness of chronic pain to most pharmacological treatments, the majority of individuals with SCI report worsening of this condition over time. Moreover, only 4-6% of patients in this cohort report improvement. Novel treatments targeting mechanisms associated with pain-maladaptive plasticity, such as electromagnetic neural stimulation, may be desirable to improve outcomes. To date, few, small clinical trials have assessed the effects of invasive and noninvasive nervous system stimulation on pain after SCI. We aimed to review initial efficacy, safety and potential predictors of response by assessing the effects of neural stimulation techniques to treat SCI pain. A literature search was performed using the PubMed database including studies using the following targeted stimulation strategies: transcranial Direct Current Stimulation (tDCS), High Definition tDCS (HD-tDCS), repetitive Transcranial Magnetical Stimulation (rTMS), Cranial Electrotherapy Stimulation (CES), Transcutaneous Electrical Nerve Stimulation (TENS), Spinal Cord Stimulation (SCS) and Motor Cortex Stimulation (MCS), published prior to June of 2012. We included studies from 1998 to 2012. Eight clinical trials and one naturalistic observational study (nine studies in total) met the inclusion criteria. Among the clinical trials, three studies assessed the effects of tDCS, two of CES, two of rTMS and one of TENS. The naturalistic study investigated the analgesic effects of SCS. No clinical trials for epidural motor cortex stimulation (MCS) or HD-tDCS were found. Parameters of stimulation and also clinical characteristics varied significantly across studies. Three out of eight studies showed larger effects sizes (0.73, 0.88 and 1.86 respectively) for pain

  10. Transcutaneous electrical nerve stimulation and transcutaneous spinal electroanalgesia: a preliminary efficacy and mechanisms-based investigation.

    Science.gov (United States)

    Palmer, Shea; Cramp, Fiona; Propert, Kate; Godfrey, Helen

    2009-09-01

    To determine the effects of transcutaneous electrical nerve stimulation (TENS) and transcutaneous spinal electroanalgesia (TSE) on mechanical pain threshold (MPT) and vibration threshold (VT). A prospective, single-blind, randomised, placebo-controlled trial. Laboratory based. Thirty-four healthy volunteers (12 men and 22 women; mean age+/-standard deviation 30+/-8 years). Exclusion criteria were conditions affecting upper limb sensation and contraindications to electrical stimulation. Participants were allocated at random to receive TENS (n=8), TSE (n=8), placebo (n=9) or control (n=9). Electrical stimulation was applied for 30 minutes (from time 18 minutes to 48 minutes) via electrodes (5 cmx5 cm) placed centrally above and below the space between the C6 and C7 spinous processes, with 5 cm between electrodes. MPT (using an algometer) and VT (using a vibrameter) were recorded on seven occasions from the first dorsal interosseous muscle of the right hand - at baseline (0 minutes) and then at 10-minute intervals until the end of the 60-minute testing period. There were no statistically significant group differences in MPT (all p>0.05). Significant group differences in VT were found at 20, 30 and 40 minutes (all ptests showed that the TENS group had significantly greater VT than both the placebo [median difference 0.30 microm, 95% confidence interval (CI) -0.05 to 0.66] and control (0.51 microm, 95% CI 0.05 to 0.97) groups at 20 minutes, and significantly greater VT than the control group (0.69 microm, 95% CI 0.20 to 1.17) at 30 minutes (all p<0.008). Electrical stimulation did not alter MPT. The increase in VT during TENS may be due to distraction or antidromic block of large-diameter nerve fibres. TSE failed to alter either outcome measure significantly.

  11. Paired associative stimulation targeting the tibialis anterior muscle using either mono or biphasic transcranial magnetic stimulation

    DEFF Research Database (Denmark)

    Mrachacz-Kersting, Natalie; Stevenson, Andrew James Thomas

    2017-01-01

    Paired associative stimulation (PAS) protocols induce plastic changes within the motor cortex. The objectives of this study were to investigate PAS effects targeting the tibialis anterior (TA) muscle using a biphasic transcranial magnetic stimulation (TMS) pulse form and, to determine whether...... a reduced intensity of this pulse would lead to significant changes as has been reported for hand muscles using a monophasic TMS pulse. Three interventions were investigated: (1) suprathreshold PAbi-PAS (n = 11); (2) suprathreshold PAmono-PAS (n = 11) where PAS was applied using a biphasic or monophasic......% for subthreshold PAbi-PAS. PAS using a biphasic pulse form at subthreshold intensities induces similar effects to conventional PAS....

  12. Intra-Subject Consistency and Reliability of Response Following 2 mA Transcranial Direct Current Stimulation.

    Science.gov (United States)

    Dyke, Katherine; Kim, Soyoung; Jackson, Georgina M; Jackson, Stephen R

    Transcranial direct current stimulation (tDCS) is a popular non-invasive brain stimulation technique that has been shown to influence cortical excitability. While polarity specific effects have often been reported, this is not always the case, and variability in both the magnitude and direction of the effects have been observed. We aimed to explore the consistency and reliability of the effects of tDCS by investigating changes in cortical excitability across multiple testing sessions in the same individuals. A within subjects design was used to investigate the effects of anodal and cathodal tDCS applied to the motor cortex. Four experimental sessions were tested for each polarity in addition to two sham sessions. Transcranial magnetic stimulation (TMS) was used to measure cortical excitability (TMS recruitment curves). Changes in excitability were measured by comparing baseline measures and those taken immediately following 20 minutes of 2 mA stimulation or sham stimulation. Anodal tDCS significantly increased cortical excitability at a group level, whereas cathodal tDCS failed to have any significant effects. The sham condition also failed to show any significant changes. Analysis of intra-subject responses to anodal stimulation across four sessions suggest that the amount of change in excitability across sessions was only weakly associated, and was found to have poor reliability across sessions (ICC = 0.276). The effects of cathodal stimulation show even poorer reliability across sessions (ICC = 0.137). In contrast ICC analysis for the two sessions of sham stimulation reflect a moderate level of reliability (ICC = .424). Our findings indicate that although 2 mA anodal tDCS is effective at increasing cortical excitability at group level, the effects are unreliable across repeated testing sessions within individual participants. Our results suggest that 2 mA cathodal tDCS does not significantly alter cortical excitability immediately following

  13. Mechanical stimulation increases proliferation, differentiation and protein expression in culture

    DEFF Research Database (Denmark)

    Grossi, Alberto; Yadav, Kavita; Lawson, Moira Ann

    2007-01-01

    Myogenesis is a complex sequence of events, including the irreversible transition from the proliferation-competent myoblast stage into fused, multinucleated myotubes. Myogenic differentiation is regulated by positive and negative signals from surrounding tissues. Stimulation due to stretch- or load...... to elucidate also the signaling pathway by which this mechanical stimulation can causes an increase in protein expression. When mechanically stimulated via laminin receptors on cell surface, C(2)C(12) cells showed an increase in cell proliferation and differentiation. Populations undergoing mechanical...... stimulation through laminin receptors show an increase in expression of Myo-D, myogenin and an increase in ERK1/2 phosphorylation. Cells stimulated via fibronectin receptors show no significant increases in fusion competence. We conclude that load induced signalling through integrin containing laminin...

  14. Spinal cord stimulation for neuropathic pain: current perspectives

    Directory of Open Access Journals (Sweden)

    Wolter T

    2014-11-01

    Full Text Available Tilman Wolter Interdisciplinary Pain Centre, University Hospital Freiburg, Freiburg, Germany Abstract: Neuropathic pain constitutes a significant portion of chronic pain. Patients with neuropathic pain are usually more heavily burdened than patients with nociceptive pain. They suffer more often from insomnia, anxiety, and depression. Moreover, analgesic medication often has an insufficient effect on neuropathic pain. Spinal cord stimulation constitutes a therapy alternative that, to date, remains underused. In the last 10 to 15 years, it has undergone constant technical advancement. This review gives an overview of the present practice of spinal cord stimulation for chronic neuropathic pain and current developments such as high-frequency stimulation and peripheral nerve field stimulation. Keywords: spinal cord stimulation, neuropathic pain, neurostimulation

  15. Claustral single cell reactions to tooth pulp stimulation in cats.

    Science.gov (United States)

    Jastreboff, P; Sikora, M; Frydrychowski, A; Słoniewski, P

    1983-01-01

    Single unit activity in the central region of the claustrum, evoked by electrical stimulation of tooth pulp or paws was studied on cats under chloralose anesthesia. The majority of cells responded in similar manner to stimulation of tooth pulp or paws, but there were cells with clear preference to a given type of stimulation. Latencies of reactions evoked by tooth pulp stimulation were significantly shorter than those for limb stimulation. In the former case latencies as short as 8 rns were observed. It is postulated that the central region of the claustrum receives a projection from the tooth pulp, and that in those cases with very short latency the projection is direct and does not involve the cerebral cortex.

  16. Vagal nerve stimulation therapy: what is being stimulated?

    Science.gov (United States)

    Kember, Guy; Ardell, Jeffrey L; Armour, John A; Zamir, Mair

    2014-01-01

    Vagal nerve stimulation in cardiac therapy involves delivering electrical current to the vagal sympathetic complex in patients experiencing heart failure. The therapy has shown promise but the mechanisms by which any benefit accrues is not understood. In this paper we model the response to increased levels of stimulation of individual components of the vagal sympathetic complex as a differential activation of each component in the control of heart rate. The model provides insight beyond what is available in the animal experiment in as much as allowing the simultaneous assessment of neuronal activity throughout the cardiac neural axis. The results indicate that there is sensitivity of the neural network to low level subthreshold stimulation. This leads us to propose that the chronic effects of vagal nerve stimulation therapy lie within the indirect pathways that target intrinsic cardiac local circuit neurons because they have the capacity for plasticity.

  17. Vagal nerve stimulation therapy: what is being stimulated?

    Directory of Open Access Journals (Sweden)

    Guy Kember

    Full Text Available Vagal nerve stimulation in cardiac therapy involves delivering electrical current to the vagal sympathetic complex in patients experiencing heart failure. The therapy has shown promise but the mechanisms by which any benefit accrues is not understood. In this paper we model the response to increased levels of stimulation of individual components of the vagal sympathetic complex as a differential activation of each component in the control of heart rate. The model provides insight beyond what is available in the animal experiment in as much as allowing the simultaneous assessment of neuronal activity throughout the cardiac neural axis. The results indicate that there is sensitivity of the neural network to low level subthreshold stimulation. This leads us to propose that the chronic effects of vagal nerve stimulation therapy lie within the indirect pathways that target intrinsic cardiac local circuit neurons because they have the capacity for plasticity.

  18. Effect of low frequency transcutaneous magnetic stimulation on sensory and motor transmission.

    Science.gov (United States)

    Leung, Albert; Shukla, Shivshil; Lee, Jacquelyn; Metzger-Smith, Valerie; He, Yifan; Chen, Jeffrey; Golshan, Shahrokh

    2015-09-01

    Peripheral nerve injury diminishes fast conducting large myelinated afferent fibers transmission but enhances smaller pain transmitting fibers firing. This aberrant afferent neuronal behavior contributes to development of chronic post-traumatic peripheral neuropathic pain (PTP-NP). Non-invasive dynamic magnetic flux stimulation has been implicated in treating PTP-NP, a condition currently not adequately addressed by other therapies including transcutaneous electrical nerve stimulation (TENS). The current study assessed the effect of low frequency transcutaneous magnetic stimulation (LFTMS) on peripheral sensory thresholds, nerve conduction properties, and TENS induced fast afferent slowing effect as measured by motor and sensory conduction studies in the ulnar nerve. Results indicated sham LFTMS with TENS (Sham + TENS) significantly (P = 0.02 and 0.007, respectively) reduces sensory conduction velocity (CV) and increases sensory onset latency (OL), and motor peak latency (PL) whereas, real LFTMS with TENS (Real + TENS) reverses effects of TENS on sensory CV and OL, and significantly (P = 0.036) increases the sensory PL. LFTMS alone significantly (P sensory PL and onset-to-peak latency. LFTMS appears to reverse TENS slowing effect on fast conducting fibers and casts a selective peripheral modulatory effect on slow conducting pain afferent fibers. © 2015 Wiley Periodicals, Inc.

  19. Electrical stimulation in exercise training

    Science.gov (United States)

    Kroll, Walter

    1994-01-01

    Electrical stimulation has a long history of use in medicine dating back to 46 A.D. when the Roman physician Largus found the electrical discharge of torpedo fishes useful in the treatment of pain produced by headache and gout. A rival Greek physician, Dioscorides, discounted the value of the torpedo fish for headache relief but did recommend its use in the treatment of hemorrhoids. In 1745, the Leyden jar and various sized electrostatic generators were used to treat angina pectoris, epilepsy, hemiplegia, kidney stones, and sciatica. Benjamin Franklin used an electrical device to treat successfully a young woman suffering from convulsive fits. In the late 1800's battery powered hydroelectric baths were used to treat chronic inflammation of the uterus while electrified athletic supporters were advertised for the treatment of male problems. Fortunately, such an amusing early history of the simple beginnings of electrical stimulation did not prevent eventual development of a variety of useful therapeutic and rehabilitative applications of electrical stimulation. Over the centuries electrical stimulation has survived as a modality in the treatment of various medical disorders with its primary application being in the rehabilitation area. Recently, a surge of new interest in electrical stimulation has been kindled by the work of a Russian sport scientist who reported remarkable muscle strength and endurance improvements in elite athletes. Yakov Kots reported his research on electric stimulation and strength improvements in 1977 at a Canadian-Soviet Exchange Symposium held at Concordia University in Montreal. Since then an explosion of new studies has been seen in both sport science and in medicine. Based upon the reported works of Kots and the present surge of new investigations, one could be misled as to the origin of electrical stimulation as a technique to increase muscle strength. As a matter of fact, electric stimulation has been used as a technique to improve

  20. Stimulation of aerobic degradation of bentazone, mecoprop and dichlorprop by oxygen addition to aquifer sediment

    DEFF Research Database (Denmark)

    Levi, Suzi; Hybel, Anne-Marie; Bjerg, Poul Løgstrup

    2014-01-01

    for the herbicides. In the presence of oxygen 14C-labelled bentazone and mecoprop were removed significantly from the two monitoring wells' groundwater samples. Oxygen was added to microcosms in order to investigate whether different oxygen concentrations stimulate the biodegradation of the three herbicides....... The highest oxygen concentrations (corresponding to 4-11mgL-1) stimulated degradation (a 14-27% increase for mecoprop, 3-9% for dichlorprop and 15-20% for bentazone) over an experimental period of 200days. Oxygen was required to biodegrade the herbicides, since no degradation was observed under anaerobic...... conditions. This is the first time bentazone degradation has been observed in aquifer material at low oxygen concentrations (2mgL-1). The sediment had substantial oxygen consumption (0.92-1.45O2g-1dw over 200days) and oxygen was depleted rapidly in most incubations soon after its addition, which might be due...

  1. Radioimmunological determination of arginine vasopressin (AVP) after stimulation and suppression of secretion

    International Nuclear Information System (INIS)

    Boeltz, E.

    1982-01-01

    As proof of the proper functioning of the hypothalamus-hypophyseal system the AVP secretion pattern which results from the analysis of plasma concentration at certain time intervals and under stimulation or suppression conditions can be used. 10 healthy control persons showed during an oral glucose intolerance test (=suppression) a significant decline in the AVP plasma concentration and after stimulation with apomorphine a healthy control person showed a large increase in AVP concentration in plasma. Because of the for the patient very stressful examination the physiological osmoregulation should first be checked during the infusion of a 2.5% NaCl solution with a minimal increase of the AVP plasma concentration. (TRV) [de

  2. Left caloric vestibular stimulation as a tool to reveal implicit and explicit parameters of body representation.

    Science.gov (United States)

    Sedda, A; Tonin, D; Salvato, G; Gandola, M; Bottini, G

    2016-04-01

    Homeostatic parameters, such as temperature, are related to body representation. In this study, we measured whether caloric vestibular stimulation (CVS) alters body temperature and tactile processing, and if in the direction predicted by a holistic body matrix representation. Skin temperature and tactile two-point discrimination (TPD) acuity were measured for both arms before, immediately after and with a delay from CVS. Participants were also administered a personality questionnaire and an anxiety inventory to rule out confounding factors. Two control experiments were planned to exclude casual variations. Our results show that temperature drops significantly in both arms after CVS. CVS also induces a bilateral improvement in tactile acuity (even though not immediately after but in the delayed condition). Finally, these effects are not due to learning, as demonstrated by the control experiment. In summary, our results suggest that vestibular stimulation updates body representation, supporting the evidence in favor of a body matrix. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. The effect of Hegu acupoint stimulation in dental acupuncture analgesia

    Directory of Open Access Journals (Sweden)

    Fransiskus Andrianto

    2007-03-01

    Full Text Available In daily life, dental treatments are often related with oral pain sensation which needs anesthesia procedures. Sometimes local anesthetics can not be used because patients have hypersensitive reaction or systemic diseases which may lead to complications. Stimulating acupoint, such as Hegu activates hypothalamus and pituitary gland to release endogenous opioid peptide substances that reduce pain sensitivity. The aim of the study was to determine Hegu acupoint stimulation effect on the pain sensitivity reduction in maxillary central incisor gingiva. The laboratory experimental research was conducted on 12 healthy male Wistar rats (3 months old, weights 150–200 grams. All rat samples received the same treatments and adapted within 1 month. The research was done in pre and post test control group design. 40-Volt electro-stimulation was done once on the maxillary central incisor gingiva prior to the bilateral Hegu acupoint stimulation, then followed by 3 times electro-stimulation with 3 minutes intervals. The pain scores were obtained based on the samples’ contraction in each electro-stimulation. The responses were categorized into 5 pain scores and statistically analyzed using Wilcoxon Test. The results showed that Hegu acupoint stimulation lowered the pain scores significantly (p < 0.05. Hegu acupoint stimulation could reduce the pain sensitivity in maxillary central incisor gingiva. Therefore, the use of acupuncture analgesia in dental pain management can be considered in the future.

  4. Effect of low-level laser stimulation on EEG.

    Science.gov (United States)

    Wu, Jih-Huah; Chang, Wen-Dien; Hsieh, Chang-Wei; Jiang, Joe-Air; Fang, Wei; Shan, Yi-Chia; Chang, Yang-Chyuan

    2012-01-01

    Conventional laser stimulation at the acupoint can induce significant brain activation, and the activation is theoretically conveyed by the sensory afferents. Whether the insensible low-level Laser stimulation outside the acupoint could also evoke electroencephalographic (EEG) changes is not known. We designed a low-level laser array stimulator (6 pcs laser diode, wavelength 830 nm, output power 7 mW, and operation frequency 10 Hz) to deliver insensible laser stimulations to the palm. EEG activities before, during, and after the laser stimulation were collected. The amplitude powers of each EEG frequency band were analyzed. We found that the low-level laser stimulation was able to increase the power of alpha rhythms and theta waves, mainly in the posterior head regions. These effects lasted at least 15 minutes after cessation of the laser stimulation. The amplitude power of beta activities in the anterior head regions decreased after laser stimulation. We thought these EEG changes comparable to those in meditation.

  5. Effect of Low-Level Laser Stimulation on EEG

    Directory of Open Access Journals (Sweden)

    Jih-Huah Wu

    2012-01-01

    Full Text Available Conventional laser stimulation at the acupoint can induce significant brain activation, and the activation is theoretically conveyed by the sensory afferents. Whether the insensible low-level Laser stimulation outside the acupoint could also evoke electroencephalographic (EEG changes is not known. We designed a low-level laser array stimulator (6 pcs laser diode, wavelength 830 nm, output power 7 mW, and operation frequency 10 Hz to deliver insensible laser stimulations to the palm. EEG activities before, during, and after the laser stimulation were collected. The amplitude powers of each EEG frequency band were analyzed. We found that the low-level laser stimulation was able to increase the power of alpha rhythms and theta waves, mainly in the posterior head regions. These effects lasted at least 15 minutes after cessation of the laser stimulation. The amplitude power of beta activities in the anterior head regions decreased after laser stimulation. We thought these EEG changes comparable to those in meditation.

  6. Differential effects of painful and non-painful stimulation on tactile processing in fibromyalgia syndrome and subjects with masochistic behaviour.

    Directory of Open Access Journals (Sweden)

    Bettina Pollok

    Full Text Available BACKGROUND: In healthy subjects repeated tactile stimulation in a conditioning test stimulation paradigm yields attenuation of primary (S1 and secondary (S2 somatosensory cortical activation, whereas a preceding painful stimulus results in facilitation. METHODOLOGY/PRINCIPAL FINDINGS: Since previous data suggest that cognitive processes might affect somatosensory processing in S1, the present study aims at investigating to what extent cortical reactivity is altered by the subjective estimation of pain. To this end, the effect of painful and tactile stimulation on processing of subsequently applied tactile stimuli was investigated in patients with fibromyalgia syndrome (FMS and in subjects with masochistic behaviour (MB by means of a 122-channel whole-head magnetoencephalography (MEG system. Ten patients fulfilling the criteria for the diagnosis of FMS, 10 subjects with MB and 20 control subjects matched with respect to age, gender and handedness participated in the present study. Tactile or brief painful cutaneous laser stimuli were applied as conditioning stimulus (CS followed by a tactile test stimulus (TS 500 ms later. While in FMS patients significant attenuation following conditioning tactile stimulation was evident, no facilitation following painful stimulation was found. By contrast, in subjects with MB no attenuation but significant facilitation occurred. Attenuation as well as facilitation applied to cortical responses occurring at about 70 ms but not to early S1 or S2 responses. Additionally, in FMS patients the amount of attenuation was inversely correlated with catastrophizing tendency. CONCLUSION: The present results imply altered cortical reactivity of the primary somatosensory cortex in FMS patients and MB possibly reflecting differences of individual pain experience.

  7. Effects of Subthalamic and Nigral Stimulation on Gait Kinematics in Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Marlieke Scholten

    2017-10-01

    Full Text Available Conventional subthalamic deep brain stimulation for Parkinson’s disease (PD presumably modulates the spatial component of gait. However, temporal dysregulation of gait is one of the factors that is tightly associated with freezing of gait (FOG. Temporal locomotor integration may be modulated differentially at distinct levels of the basal ganglia. Owing to its specific descending brainstem projections, stimulation of the substantia nigra pars reticulata (SNr area might modulate spatial and temporal parameters of gait differentially compared to standard subthalamic nucleus (STN stimulation. Here, we aimed to characterize the differential effect of STN or SNr stimulation on kinematic gait parameters. We analyzed biomechanical parameters during unconstrained over ground walking in 12 PD patients with subthalamic deep brain stimulation and FOG. Patients performed walking in three therapeutic conditions: (i Off stimulation, (ii STN stimulation (alone, and (iii SNr stimulation (alone. SNr stimulation was achieved by stimulating the most caudal contact of the electrode. We recorded gait using three sensors (each containing a tri-axial accelerometer, gyroscope, and magnetometer attached on both left and right ankle, and to the lumbar spine. STN stimulation improved both the spatial features (stride length, stride length variability and the temporal parameters of gait. SNr stimulation improved temporal parameters of gait (swing time asymmetry. Correlation analysis suggested that patients with more medial localization of the SNr contact associated with a stronger regularization of gait. These results suggest that SNr stimulation might support temporal regularization of gait integration.

  8. Comparison of the shock artifacts induced by tripolar and bipolar electrical stimulation techniques.

    Science.gov (United States)

    Wee, A S; Jiles, K; Brennan, R

    2001-01-01

    Tripolar and bipolar electrical stimulation procedures were performed on the upper limbs of eight subjects. The mid-forearm was stimulated electrically (tripolar or bipolar) by surface electrodes, and the induced stimulus shock artifacts were recorded simultaneously from the wrist and elbow. During tripolar stimulation, two types of stimulating configurations were utilized: with the center electrode designated as the cathode and the two outermost electrodes connected to a common anode, and vice versa. During bipolar stimulation, the center electrode served as one pole of the stimulator, and one of the two outermost electrodes of the tripolar stimulator was disconnected. The stimulus intensity was kept constant in all stimulating procedures. Artifacts were reduced significantly during tripolar compared to bipolar stimulation, if the outermost electrodes of the tripolar stimulator (which were facing the recording electrodes) were also oriented toward the recording sites during bipolar stimulation and had the same stimulus polarity. Artifacts were slightly reduced in amplitude from tripolar stimulation, if the center electrode were oriented toward the recording sites during bipolar stimulation and had the same stimulus polarity as previously used during tripolar stimulation.

  9. Intermittent θ burst stimulation over primary motor cortex enhances movement-related β synchronisation.

    Science.gov (United States)

    Hsu, Ya-Fang; Liao, Kwong-Kum; Lee, Po-Lei; Tsai, Yun-An; Yeh, Chia-Lung; Lai, Kuan-Lin; Huang, Ying-Zu; Lin, Yung-Yang; Lee, I-Hui

    2011-11-01

    The objective of this study is to investigate how transcranial magnetic intermittent theta burst stimulation (iTBS) with a prolonged protocol affects human cortical excitability and movement-related oscillations. Using motor-evoked potentials (MEPs) and movement-related magnetoencephalography (MEG), we assessed the changes of corticospinal excitability and cortical oscillations after iTBS with double the conventional stimulation time (1200 pulses, iTBS1200) over the primary motor cortex (M1) in 10 healthy subjects. Continuous TBS (cTBS1200) and sham stimulation served as controls. iTBS1200 facilitated MEPs evoked from the conditioned M1, while inhibiting MEPs from the contralateral M1 for 30 min. By contrast, cTBS1200 inhibited MEPs from the conditioned M1. Importantly, empirical mode decomposition-based MEG analysis showed that the amplitude of post-movement beta synchronisation (16-26 Hz) was significantly increased by iTBS1200 at the conditioned M1, but was suppressed at the nonconditioned M1. Alpha (8-13 Hz) and low gamma-ranged (35-45 Hz) rhythms were not notably affected. Movement kinetics remained consistent throughout. TBS1200 modulated corticospinal excitability in parallel with the direction of conventional paradigms with modestly prolonged efficacy. Moreover, iTBS1200 increased post-movement beta synchronisation of the stimulated M1, and decreased that of the contralateral M1, probably through interhemispheric interaction. Our results provide insight into the underlying mechanism of TBS and reinforce the connection between movement-related beta synchronisation and corticospinal output. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  10. PI 3-kinase signalling in platelets: the significance of synergistic, autocrine stimulation.

    Science.gov (United States)

    Selheim, F; Holmsen, H; Vassbotn, F S

    2000-03-01

    Phosphoinositide 3-kinases (PI 3Ks) play a key role in regulation of intracellular signalling and cellular function, including cell proliferation, apoptosis, chemotaxis, membrane trafficking and platelet activation. The PI 3Ks are grouped into three classes on the basis on their structure and in vitro substrate specificity. Class I are activated by a variety of agonists which mediate their effect through tyrosine kinase-linked or G-protein-linked receptors. In vivo class I PI 3Ks seem to preferentially phosphorylate the D3 hydroxyls of the inositol moiety of PtdIns(4,5)P2 to produce PtdIns(3,4,5)P3. However, class II PI 3Ks preferentially phosphorylate the D3 hydroxyl of PtdIns and PtdIns(4)P to produce PtdIns(3)P and PtdIns(3,4)P2, respectively. The late accumulation of PtdIns(3,4)P2 has been suggested to play an important role in irreversible platelet aggregation. In human platelets the class II PI 3K isoform HsC2-PI 3K is activated in an integrin alpha IIb beta 3 + fibrinogen-dependent manner. Class III PI 3Ks phosphorylate PtdIns to produce PtdIns(3)P, which play a crucial role in vesicular trafficking. Recent work has suggested that crosstalk between individual receptors and their downstream signal pathways play a central role in PI 3K signalling responses. In this review, we will concentrate on recent advances regarding the regulation of platelet PI 3Ks.

  11. The impact of neuromuscular electrical stimulation on recovery after intensive, muscle damaging, maximal speed training in professional team sports players.

    Science.gov (United States)

    Taylor, Tom; West, Daniel J; Howatson, Glyn; Jones, Chris; Bracken, Richard M; Love, Thomas D; Cook, Christian J; Swift, Eamon; Baker, Julien S; Kilduff, Liam P

    2015-05-01

    During congested fixture periods in team sports, limited recovery time and increased travel hinder the implementation of many recovery strategies; thus alternative methods are required. We examined the impact of a neuromuscular electrical stimulation device on 24-h recovery from an intensive training session in professional players. Twenty-eight professional rugby and football academy players completed this randomised and counter-balanced study, on 2 occasions, separated by 7 days. After baseline perceived soreness, blood (lactate and creatine kinase) and saliva (testosterone and cortisol) samples were collected, players completed a standardised warm-up and baseline countermovement jumps (jump height). Players then completed 60 m × 50 m maximal sprints, with 5 min recovery between efforts. After completing the sprint session, players wore a neuromuscular electrical stimulation device or remained in normal attire (CON) for 8 h. All measures were repeated immediately, 2 and 24-h post-sprint. Player jump height was reduced from baseline at all time points under both conditions; however, at 24-h neuromuscular electrical stimulation was significantly more recovered (mean±SD; neuromuscular electrical stimulation -3.2±3.2 vs. CON -7.2±3.7%; P0.05). Neuromuscular electrical stimulation improves recovery from intensive training in professional team sports players. This strategy offers an easily applied recovery strategy which may have particular application during sleep and travel. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  12. The effect of sensory stimulation provided by family on arterial blood oxygen saturation in critical care patients.

    Science.gov (United States)

    Yousefi, Hojatollah; Naderi, Mojgan; Daryabeigi, Reza

    2015-01-01

    Stressors in the intensive care unit (ICU) impair patients' comfort, excite the stress response, and increase oxygen consumption in their body. Non-medical interventions are recommended by several studies as a treatment to improve comfort in the ICU patients. Sensory stimulation is one of the most important interventions. Since arterial blood oxygen saturation is an important index of patients' clinical and respiratory condition, this study aimed to investigate the effect of sensory stimulation provided by family on arterial blood oxygen saturation in critical care patients. This study is a clinical trial conducted on 64 patients hospitalized in the ICU wards of Al-Zahra and Kashani hospitals in Isfahan, Iran in 2012 and 2013. The patients were selected by simple sampling method and were randomly assigned to two groups (study and control). Patients' arterial blood oxygen saturations were measured 10 min before, immediately after, 10 min and 30 min after sensory stimulation in the study group, and simultaneously in the control group without any intervention. Repeated measures analysis of variance (ANOVA) showed a significant difference in the mean of arterial blood oxygen saturation levels 10 min before, immediately after, 10 min and 30 min after sensory stimulation in the study group (P 0.18). Application of sensory stimulations as a nursing and non-medical intervention by the family members improves comfort and increases the level of blood oxygen saturation in critical care patients.

  13. Systemic administration of thrombin peptide TP508 enhances VEGF-stimulated angiogenesis and attenuates effects of chronic hypoxia

    Science.gov (United States)

    Olszewska-Pazdrak, Barbara; Carney, Darrell H.

    2015-01-01

    Revascularization of chronic wounds and ischemic tissue is attenuated by endothelial dysfunction and the inability of angiogenic factors to stimulate angiogenesis. We recently showed that TP508, a nonproteolytic thrombin peptide, increases perfusion and NO-dependent vasodilation in hearts with chronic ischemia and stimulates NO production by endothelial cells. In this study, we investigated systemic in vivo effects of TP508 on VEGF-stimulated angiogenesis in vitro using aortic explants in normoxic and hypoxic conditions. Mice were injected with saline or TP508 and 24h later aortas were removed and cultured to quantify endothelial sprouting. TP508 injection increased endothelial sprouting and potentiated the in vitro response to VEGF. Exposure of control explants to hypoxia inhibited basal and VEGF-stimulated endothelial cell sprouting. This effect of hypoxia was significantly prevented by TP508 injection. Thus, TP508 systemic administration increases responsiveness of aortic endothelial cells to VEGF and diminishes the effect of chronic hypoxia on endothelial cell sprouting. Studies using human endothelial cells in culture suggest that protective effects of TP508 during hypoxia may involve stimulation of endothelial cell NO production. These data suggest potential clinical benefit of using a combination of systemic TP508 and local VEGF as a therapy for revascularization of ischemic tissue. PMID:23594718

  14. Transcranial alternating current stimulation with sawtooth waves: simultaneous stimulation and EEG recording

    Directory of Open Access Journals (Sweden)

    James eDowsett

    2016-03-01

    Full Text Available Transcranial alternating current stimulation (tACS has until now mostly been administered as an alternating sinusoidal wave. Despite modern tACS stimulators being able to deliver alternating current with any arbitrary shape there has been no systematic exploration into the relative benefits of different waveforms. As tACS is a relatively new technique there is a huge parameter space of unexplored possibilities which may prove superior or complimentary to the traditional sinusoidal waveform. Here we begin to address this with an investigation into the effects of sawtooth wave tACS on individual alpha power. Evidence from animal models suggests that the gradient and direction of an electric current should be important factors for the subsequent neural firing rate; we compared positive and negative ramp sawtooth waves to test this. An additional advantage of sawtooth waves is that the resulting artefact in the electroencephalogram (EEG recording is significantly simpler to remove than a sine wave; accordingly we were able to observe alpha oscillations both during and after stimulation.We found that positive ramp sawtooth, but not negative ramp sawtooth, significantly enhanced alpha power during stimulation relative to sham (p<0.01. In addition we tested for an after-effect of both sawtooth and sinusoidal stimulation on alpha power but in this case did not find any significant effect. This preliminary study paves the way for further investigations into the effect of the gradient and direction of the current in tACS which could significantly improve the usefulness of this technique.

  15. Leucine stimulation of skeletal muscle protein synthesis

    International Nuclear Information System (INIS)

    Layman, D.K.; Grogan, C.K.

    1986-01-01

    Previous work in this laboratory has demonstrated a stimulatory effect of leucine on skeletal muscle protein synthesis measured in vitro during catabolic conditions. Studies in other laboratories have consistently found this effect in diaphragm muscle, however, studies examining effects on nitrogen balance or with in vivo protein synthesis in skeletal muscle are equivocal. This experiment was designed to determine the potential of leucine to stimulate skeletal muscle protein synthesis in vivo. Male Sprague-Dawley rats weighing 200 g were fasted for 12 hrs, anesthetized, a jugular cannula inserted, and protein synthesis measured using a primed continuous infusion of 14 C-tyrosine. A plateau in specific activity was reached after 30 to 60 min and maintained for 3 hrs. The leucine dose consisted of a 240 umole priming dose followed by a continuous infusion of 160 umoles/hr. Leucine infusion stimulated protein synthesis in the soleus muscle (28%) and in the red (28%) and white portions (12%) of the gastrocnemius muscle compared with controls infused with only tyrosine. The increased rates of protein synthesis were due to increased incorporation of tyrosine into protein and to decreased specific activity of the free tyrosine pool. These data indicate that infusion of leucine has the potential to stimulate in vivo protein synthesis in skeletal muscles

  16. A novel paradigm to evaluate conditioned pain modulation in fibromyalgia

    Directory of Open Access Journals (Sweden)

    Schoen CJ

    2016-09-01

    Full Text Available Cynthia J Schoen,1,* Jacob N Ablin,2,* Eric Ichesco,1 Rupal J Bhavsar,3 Laura Kochlefl,1 Richard E Harris,1 Daniel J Clauw,1 Richard H Gracely,4 Steven E Harte1 1Department of Anesthesiology, Chronic Pain and Fatigue Research Center, University of Michigan, Ann Arbor, MI, USA; 2Institute of Rheumatology, Tel Aviv Suorasky Medical Center, and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; 3Department of Neurology, University of Pennsylvania, Philadelphia, PA, 4Department of Endodontics, University of North Carolina – Chapel Hill, Chapel Hill, NC, USA *These authors contributed equally to this work Introduction: Application of noxious stimulation to one body area reduces pain sensitivity in a remote body area through activation of an endogenous pain-inhibitory network, a behavioral phenomenon referred to as conditioned pain modulation (CPM. The efficiency of CPM is predictive of a variety of health outcomes, while impaired CPM has been associated with various chronic pain conditions. Current methods used to assess CPM vary widely, and interest in CPM method development remains strong. Here, we evaluated a novel method for assessing CPM in healthy controls and fibromyalgia (FM patients using thumb pressure as both a test and conditioning stimulus.Methods: Sixteen female FM patients and 14 matched healthy controls underwent CPM testing with thumbnail pressure as the test stimulus, and either cold water or noxious pressure as the conditioning stimulus. CPM magnitude was evaluated as the difference in pain rating of the test stimulus applied before and during the conditioning stimulus.Results: In healthy controls, application of either pressure or cold water conditioning stimulation induced CPM as evidenced by a significant reduction in test stimulus pain rating during conditioning (P=0.007 and P=0.021, respectively. In contrast, in FM patients, neither conditioning stimulus induced a significant CPM effect P-values >0

  17. The Impact of Monaural Beat Stimulation on Anxiety and Cognition

    Directory of Open Access Journals (Sweden)

    Leila Chaieb

    2017-05-01

    Full Text Available Application of auditory beat stimulation has been speculated to provide a promising new tool with which to alleviate symptoms of anxiety and to enhance cognition. In spite of reportedly similar EEG effects of binaural and monaural beats, data on behavioral effects of monaural beats are still lacking. Therefore, we examined the impact of monaural beat stimulation on anxiety, mood and memory performance. We aimed to target states related to anxiety levels and general well-being, in addition to long-term and working memory processes, using monaural beats within the range of main cortical rhythms. Theta (6 Hz, alpha (10 Hz and gamma (40 Hz beat frequencies, as well as a control stimulus were applied to healthy participants for 5 min. After each stimulation period, participants were asked to evaluate their current mood state and to perform cognitive tasks examining long-term and working memory processes, in addition to a vigilance task. Monaural beat stimulation was found to reduce state anxiety. When evaluating responses for the individual beat frequencies, positive effects on state anxiety were observed for all monaural beat conditions compared to control stimulation. Our results indicate a role for monaural beat stimulation in modulating state anxiety and are in line with previous studies reporting anxiety-reducing effects of auditory beat stimulation.

  18. The Impact of Monaural Beat Stimulation on Anxiety and Cognition.

    Science.gov (United States)

    Chaieb, Leila; Wilpert, Elke C; Hoppe, Christian; Axmacher, Nikolai; Fell, Juergen

    2017-01-01

    Application of auditory beat stimulation has been speculated to provide a promising new tool with which to alleviate symptoms of anxiety and to enhance cognition. In spite of reportedly similar EEG effects of binaural and monaural beats, data on behavioral effects of monaural beats are still lacking. Therefore, we examined the impact of monaural beat stimulation on anxiety, mood and memory performance. We aimed to target states related to anxiety levels and general well-being, in addition to long-term and working memory processes, using monaural beats within the range of main cortical rhythms. Theta (6 Hz), alpha (10 Hz) and gamma (40 Hz) beat frequencies, as well as a control stimulus were applied to healthy participants for 5 min. After each stimulation period, participants were asked to evaluate their current mood state and to perform cognitive tasks examining long-term and working memory processes, in addition to a vigilance task. Monaural beat stimulation was found to reduce state anxiety. When evaluating responses for the individual beat frequencies, positive effects on state anxiety were observed for all monaural beat conditions compared to control stimulation. Our results indicate a role for monaural beat stimulation in modulating state anxiety and are in line with previous studies reporting anxiety-reducing effects of auditory beat stimulation.

  19. Multielectrode intrafascicular and extraneural stimulation

    NARCIS (Netherlands)

    Veltink, Petrus H.; van Alste, Jan A.; Boom, H.B.K.

    1989-01-01

    The relationship between nerve stimulation, pulse amplitude and isometric muscle force was measured to investigate recruitment of motor units. Force addition experiments were performed to obtain insight in the intersection of motor unit groups recruited by different electrodes. Intrafascicular and

  20. Noninvasive Stimulation of the Human Brain

    DEFF Research Database (Denmark)

    Di Lazzaro, Vincenzo; Rothwell, John; Capogna, Marco

    2017-01-01

    Noninvasive brain stimulation methods, such as transcranial electric stimulation and transcranial magnetic stimulation are widely used tools for both basic research and clinical applications. However, the cortical circuits underlying their effects are poorly defined. Here we review the current...

  1. Stimulation and recording electrodes for neural prostheses

    CERN Document Server

    Pour Aryan, Naser; Rothermel, Albrecht

    2015-01-01

    This book provides readers with basic principles of the electrochemistry of the electrodes used in modern, implantable neural prostheses. The authors discuss the boundaries and conditions in which the electrodes continue to function properly for long time spans, which are required when designing neural stimulator devices for long-term in vivo applications. Two kinds of electrode materials, titanium nitride and iridium are discussed extensively, both qualitatively and quantitatively. The influence of the counter electrode on the safety margins and electrode lifetime in a two electrode system is explained. Electrode modeling is handled in a final chapter.

  2. Non-invasive electrical brain stimulation: from acute to late-stage treatment of central nervous system damage

    Directory of Open Access Journals (Sweden)

    Petra Henrich-Noack

    2017-01-01

    Full Text Available Non-invasive brain current stimulation (NIBS is a promising and versatile tool for inducing neuroplasticity, protection and functional rehabilitation of damaged neuronal systems. It is technically simple, requires no surgery, and has significant beneficial effects. However, there are various technical approaches for NIBS which influence neuronal networks in significantly different ways. Transcranial direct current stimulation (tDCS, alternating current stimulation (ACS and repetitive transcranial magnetic stimulation (rTMS all have been applied to modulate brain activity in animal experiments under normal and pathological conditions. Also clinical trials have shown that tDCS, rTMS and ACS induce significant behavioural effects and can – depending on the parameters chosen – enhance or decrease brain excitability and influence performance and learning as well as rehabilitation and protective mechanisms. The diverse phaenomena and partially opposing effects of NIBS are not yet fully understood and mechanisms of action need to be explored further in order to select appropriate parameters for a given task, such as current type and strength, timing, distribution of current densities and electrode position. In this review, we will discuss the various parameters which need to be considered when designing a NIBS protocol and will put them into context with the envisaged applications in experimental neurobiology and medicine such as vision restoration, motor rehabilitation and cognitive enhancement.

  3. Effects of stimulated repopulation on oral mucositis during conventional radiotherapy

    International Nuclear Information System (INIS)

    Doerr, W.; Jacubek, A.; Kummermehr, J.; Herrmann, Th.; Doelling-Jochem, I.; Eckelt, U.

    1995-01-01

    The effect of local conditioning of human oral mucosa by silver nitrate solution (3%) on epithelial proliferation rates was tested in 11 healthy volunteers by in vitro labelling of biopsies with tritiated thymidine. Compared to control biopsies from 13 volunteers, stimulation over 3 days, 3 times per day, yielded a significant (p = 0.006) increase in the epithelial labelling index (LI) from 4.75 ± 0.32% to 6.85 ± 0.65%, i.e., by 44%. The increase in the absolute number of labelled cells per mm epithelial length was dependent on the overall cell density at the various intraoral sites and varied between 45% in the maxillary vestibule and 91% at the floor of the mouth. In an analysis of variance, stimulation turned out to be the most important source causing the effect (p = 0.011 for LI and 0.015 for labelled cells per mm). In a radiotherapy trial with conventional postoperative treatment with 5 x 2 Gy/week to a total dose of 60 Gy in 6 weeks, the left buccal mucosa in 10 patients with squamous cell carcinomas of the head and neck was conditioned (3% silver nitrate, 3 times per day, 5 days before and the first 2 days of radiotherapy) while the contralateral mucosa, receiving an identical dose, served as individual control. Mucositis scores according to the EORTC/RTOG or the Dische system showed that the time course and severity of the mucosal response was almost identical in both cheeks, which is in clear contrast to a previous clinical study (Maciejewski et al. Radiother. Oncol. 22, 7-11, 1991). Differences in radiation dose intensity, i.e., weekly dose, in these studies are discussed as a tentative explanation for the different clinical findings

  4. Perceptual embodiment of prosthetic limbs by transcutaneous electrical nerve stimulation.

    Science.gov (United States)

    Mulvey, Matthew R; Fawkner, Helen J; Radford, Helen E; Johnson, Mark I

    2012-01-01

      In able-bodied participants, it is possible to induce a sense of perceptual embodiment in an artificial hand using a visual-tactile illusion. In amputee patients, electrical stimulation of sensory afferents using transcutaneous electrical nerve stimulation (TENS) has been shown to generate somatic sensations in an amputee's phantom limb(s). However, the effects of TENS on the perceptual embodiment of an artificial limb are not known. Our objective was to investigate the effects of TENS on the perceptual embodiment of an artificial limb in fully intact able-bodied participants.   We used a modified version of the rubber hand illusion presented to 30 able-bodied participants (16 women, 14 men) to convey TENS paresthesia to an artificial hand. TENS electrodes were located over superficial radial nerve on the lateral aspect of the right forearm (1 cm proximal to the wrist), which was hidden from view. TENS intensity was increased to a strong non-painful TENS sensation (electrical paresthesia) was felt beneath the electrodes and projecting into the fingers of the hand. The electrical characteristics of TENS were asymmetric biphasic electrical pulsed waves, continuous pulse pattern, 120 Hz pulse frequency (rate), and 80 µs pulse duration (width).   Participants reported significantly higher intensities of the rubber hand illusion during the two TENS conditions (mean = 5.8, standard deviation = 1.9) compared with the two non-TENS conditions (mean = 4.9, standard deviation = 1.7), p embodiment of an artificial hand. Further exploratory studies involving an amputee population are warranted. © 2011 International Neuromodulation Society.

  5. Vagus nerve stimulation modulates visceral pain-related affective memory.

    Science.gov (United States)

    Zhang, Xu; Cao, Bing; Yan, Ni; Liu, Jin; Wang, Jun; Tung, Vivian Oi Vian; Li, Ying

    2013-01-01

    Within a biopsychosocial model of pain, pain is seen as a conscious experience modulated by mental, emotional and sensory mechanisms. Recently, using a rodent visceral pain assay that combines the colorectal distension (CRD) model with the conditioned place avoidance (CPA) paradigms, we measured a learned behavior that directly reflects the affective component of visceral pain, and showed that perigenual anterior cingulate cortex (pACC) activation is critical for memory processing involved in long-term visceral affective state and prediction of aversive stimuli by contextual cue. Electrical vagus nerve stimulation (VNS) has become an established therapy for treatment-resistant epilepsy. VNS has also been shown to enhance memory performance in rats and humans. High-intensity VNS (400 μA) immediately following conditional training significantly increases the CRD-induced CPA scores, and enhanced the pain affective memory retention. In contrast, VNS (400 μA) had no effect on CPA induced by non-nociceptive aversive stimulus (U69,593). Low-intensity VNS (40 μA) had no effect on CRD-induced CPA. Electrophysiological recording showed that VNS (400 μA) had no effect on basal and CRD-induced ACC neuronal firing. Further, VNS did not alter CRD-induced visceral pain responses suggesting high intensity VNS facilitates visceral pain aversive memory independent of sensory discriminative aspects of visceral pain processing. The findings that vagus nerve stimulation facilities visceral pain-related affective memory underscore the importance of memory in visceral pain perception, and support the theory that postprandial factors may act on vagal afferents to modulate ongoing nature of visceral pain-induced affective disorder observed in the clinic, such as irritable bowel syndrome. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Differential effects of subcutaneous electrical stimulation (SQS) and transcutaneous electrical nerve stimulation (TENS) in rodent models of chronic neuropathic or inflammatory pain.

    Science.gov (United States)

    Vera-Portocarrero, Louis P; Cordero, Toni; Billstrom, Tina; Swearingen, Kim; Wacnik, Paul W; Johanek, Lisa M

    2013-01-01

    Electrical stimulation has been used for many years for the treatment of pain. Present-day research demonstrates that stimulation targets and parameters impact the induction of specific pain-modulating mechanisms. New targets are increasingly being investigated clinically, but the scientific rationale for a particular target is often not well established. This present study compares the behavioral effects of targeting peripheral axons by electrode placement in the subcutaneous space vs. electrode placement on the surface of the skin in a rodent model. Rodent models of inflammatory and neuropathic pain were used to investigate subcutaneous electrical stimulation (SQS) vs. transcutaneous electrical nerve stimulation (TENS). Electrical parameters and relative location of the leads were held constant under each condition. SQS had cumulative antihypersensitivity effects in both inflammatory and neuropathic pain rodent models, with significant inhibition of mechanical hypersensitivity observed on days 3-4 of treatment. In contrast, reduction of thermal hyperalgesia in the inflammatory model was observed during the first four days of treatment with SQS, and reduction of cold allodynia in the neuropathic pain model was seen only on the first day with SQS. TENS was effective in the inflammation model, and in agreement with previous studies, tolerance developed to the antihypersensitivity effects of TENS. With the exception of a reversal of cold hypersensitivity on day 1 of testing, TENS did not reveal significant analgesic effects in the neuropathic pain rodent model. The results presented show that TENS and SQS have different effects that could point to unique biologic mechanisms underlying the analgesic effect of each therapy. Furthermore, this study is the first to demonstrate in an animal model that SQS attenuates neuropathic and inflammatory-induced pain behaviors. © 2013 Medtronic, Inc.

  7. Physiological effects of mechanical pain stimulation at the lower back measured by functional near-infrared spectroscopy and capnography.

    Science.gov (United States)

    Holper, Lisa; Gross, Andrea; Scholkmann, Felix; Humphreys, B Kim; Meier, Michael L; Wolf, Ursula; Wolf, Martin; Hotz-Boendermaker, Sabina

    2014-03-01

    The aim was to investigate the effect of mechanical pain stimulation at the lower back on hemodynamic and oxygenation changes in the prefrontal cortex (PFC) assessed by functional near-infrared spectroscopy (fNIRS) and on the partial pressure of end-tidal carbon dioxide ( PetCO 2) measured by capnography. 13 healthy subjects underwent three measurements (M) during pain stimulation using pressure pain threshold (PPT) at three locations, i.e., the processus spinosus at the level of L4 (M1) and the lumbar paravertebral muscles at the level of L1 on the left (M2) and the right (M3) side. Results showed that only in the M2 condition the pain stimulation elicited characteristic patterns consisting of (1) a fNIRS-derived decrease in oxy- and total hemoglobin concentration and tissue oxygen saturation, an increase in deoxy-hemoglobin concentration, (2) a decrease in the PetCO 2 response and (3) a decrease in coherence between fNIRS parameters and PetCO 2 responses in the respiratory frequency band (0.2-0.5 Hz). We discuss the comparison between M2 vs. M1 and M3, suggesting that the non-significant findings in the two latter measurements were most likely subject to effects of the different stimulated tissues, the stimulated locations and the stimulation order. We highlight that PetCO 2 is a crucial parameter for proper interpretation of fNIRS data in experimental protocols involving pain stimulation. Together, our data suggest that the combined fNIRS-capnography approach has potential for further development as pain monitoring method, such as for evaluating clinical pain treatment.

  8. Operant conditioning of facial displays of pain.

    Science.gov (United States)

    Kunz, Miriam; Rainville, Pierre; Lautenbacher, Stefan

    2011-06-01

    The operant model of chronic pain posits that nonverbal pain behavior, such as facial expressions, is sensitive to reinforcement, but experimental evidence supporting this assumption is sparse. The aim of the present study was to investigate in a healthy population a) whether facial pain behavior can indeed be operantly conditioned using a discriminative reinforcement schedule to increase and decrease facial pain behavior and b) to what extent these changes affect pain experience indexed by self-ratings. In the experimental group (n = 29), the participants were reinforced every time that they showed pain-indicative facial behavior (up-conditioning) or a neutral expression (down-conditioning) in response to painful heat stimulation. Once facial pain behavior was successfully up- or down-conditioned, respectively (which occurred in 72% of participants), facial pain displays and self-report ratings were assessed. In addition, a control group (n = 11) was used that was yoked to the reinforcement plans of the experimental group. During the conditioning phases, reinforcement led to significant changes in facial pain behavior in the majority of the experimental group (p .136). Fine-grained analyses of facial muscle movements revealed a similar picture. Furthermore, the decline in facial pain displays (as observed during down-conditioning) strongly predicted changes in pain ratings (R(2) = 0.329). These results suggest that a) facial pain displays are sensitive to reinforcement and b) that changes in facial pain displays can affect self-report ratings.

  9. Repetitive transcranial magnetic stimulation for hallucination in schizophrenia spectrum disorders: A meta-analysis.

    Science.gov (United States)

    Zhang, Yingli; Liang, Wei; Yang, Shichang; Dai, Ping; Shen, Lijuan; Wang, Changhong

    2013-10-05

    This study assessed the efficacy and tolerability of repetitive transcranial magnetic stimulation for treatment of auditory hallucination of patients with schizophrenia spectrum disorders. Online literature retrieval was conducted using PubMed, ISI Web of Science, EMBASE, Medline and Cochrane Central Register of Controlled Trials databases from January 1985 to May 2012. Key words were "transcranial magnetic stimulation", "TMS", "repetitive transcranial magnetic stimulation", and "hallucination". Selected studies were randomized controlled trials assessing therapeutic efficacy of repetitive transcranial magnetic stimulation for hallucination in patients with schizophrenia spectrum disorders. Experimental intervention was low-frequency repetitive transcranial magnetic stimulation in left temporoparietal cortex for treatment of auditory hallucination in schizophrenia spectrum disorders. Control groups received sham stimulation. The primary outcome was total scores of Auditory Hallucinations Rating Scale, Auditory Hallucination Subscale of Psychotic Symptom Rating Scale, Positive and Negative Symptom Scale-Auditory Hallucination item, and Hallucination Change Scale. Secondary outcomes included response rate, global mental state, adverse effects and cognitive function. Seventeen studies addressing repetitive transcranial magnetic stimulation for treatment of schizophrenia spectrum disorders were screened, with controls receiving sham stimulation. All data were completely effective, involving 398 patients. Overall mean weighted effect size for repetitive transcranial magnetic stimulation versus sham stimulation was statistically significant (MD = -0.42, 95%CI: -0.64 to -0.20, P = 0.000 2). Patients receiving repetitive transcranial magnetic stimulation responded more frequently than sham stimulation (OR = 2.94, 95%CI: 1.39 to 6.24, P = 0.005). No significant differences were found between active repetitive transcranial magnetic stimulation and sham stimulation for

  10. Economics of nuclear gas stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Frank, G W [Austral Oil Company Incorporated, Houston, TX (United States); Coffer, H F; Luetkehans, G R [CER Geonuclear Corporation, Las Vegas, NV (United States)

    1970-05-01

    Nuclear stimulation of the Mesaverde Formation in the Piceance Basin appears to be the only available method that can release the contained gas economically. In the Rulison Field alone estimates show six to eight trillion cubic feet of gas may be made available by nuclear means, and possibly one hundred trillion cubic feet could be released in the Piceance Basin. Several problems remain to be solved before this tremendous gas reserve can be tapped. Among these are (1) rates of production following nuclear stimulation; (2) costs of nuclear stimulation; (3) radioactivity of the chimney gas; and (4) development of the ideal type of device to carry out the stimulations. Each of these problems is discussed in detail with possible solutions suggested. First and foremost is the rate at which gas can be delivered following nuclear stimulation. Calculations have been made for expected production behavior following a 5-kiloton device and a 40-kiloton device with different permeabilities. These are shown, along with conventional production history. The calculations show that rates of production will be sufficient if costs can be controlled. Costs of nuclear stimulation must be drastically reduced for a commercial process. Project Rulison will cost approximately $3.7 million, excluding lease costs, preliminary tests, and well costs. At such prices, nothing can possibly be commercial; however, these costs can come down in a logical step-wise fashion. Radiation contamination of the gas remains a problem. Three possible solutions to this problem are included. (author)

  11. Economics of nuclear gas stimulation

    International Nuclear Information System (INIS)

    Frank, G.W.; Coffer, H.F.; Luetkehans, G.R.

    1970-01-01

    Nuclear stimulation of the Mesaverde Formation in the Piceance Basin appears to be the only available method that can release the contained gas economically. In the Rulison Field alone estimates show six to eight trillion cubic feet of gas may be made available by nuclear means, and possibly one hundred trillion cubic feet could be released in the Piceance Basin. Several problems remain to be solved before this tremendous gas reserve can be tapped. Among these are (1) rates of production following nuclear stimulation; (2) costs of nuclear stimulation; (3) radioactivity of the chimney gas; and (4) development of the ideal type of device to carry out the stimulations. Each of these problems is discussed in detail with possible solutions suggested. First and foremost is the rate at which gas can be delivered following nuclear stimulation. Calculations have been made for expected production behavior following a 5-kiloton device and a 40-kiloton device with different permeabilities. These are shown, along with conventional production history. The calculations show that rates of production will be sufficient if costs can be controlled. Costs of nuclear stimulation must be drastically reduced for a commercial process. Project Rulison will cost approximately $3.7 million, excluding lease costs, preliminary tests, and well costs. At such prices, nothing can possibly be commercial; however, these costs can come down in a logical step-wise fashion. Radiation contamination of the gas remains a problem. Three possible solutions to this problem are included. (author)

  12. A twin study of the neuropsychological consequences of stimulant abuse.

    Science.gov (United States)

    Toomey, Rosemary; Lyons, Michael J; Eisen, Seth A; Xian, Hong; Chantarujikapong, Sunanta; Seidman, Larry J; Faraone, Stephen V; Tsuang, Ming T

    2003-03-01

    Previous studies document neuropsychological deficits associated with stimulant abuse, but findings are inconsistent. We identified 50 twin pairs in which only 1 member had heavy stimulant abuse (cocaine and/or amphetamines) ending at least 1 year before the evaluation. The co-twin control research design controls for familial vulnerability and makes it easier to identify neuropsychological deficits that are consequences of stimulant abuse. Subjects were administered an extensive neuropsychological test battery organized into the following 5 functions: attention, executive functioning, motor skills, intelligence, and memory. Multivariate tests showed that abusers performed significantly worse than nonabusers on functions of attention and motor skills. Within each of these functions, univariate tests showed that abusers performed significantly worse on certain tests of motor skills and attention. In contrast, abusers performed significantly better on one test of attention measuring visual vigilance. Within the abuser group, higher levels of stimulant use were largely uncorrelated with neuropsychological test scores, although a few significant correlations indicated better functioning with more stimulant use. With ideal controls, this study demonstrates that deficits in attention and motor skills persist after 1 year of abstinence from stimulant use and raises hypotheses regarding relative strengths on a vigilance task among abusers.

  13. Biomarkers and Stimulation Algorithms for Adaptive Brain Stimulation

    Directory of Open Access Journals (Sweden)

    Kimberly B. Hoang

    2017-10-01

    Full Text Available The goal of this review is to describe in what ways feedback or adaptive stimulation may be delivered and adjusted based on relevant biomarkers. Specific treatment mechanisms underlying therapeutic brain stimulation remain unclear, in spite of the demonstrated efficacy in a number of nervous system diseases. Brain stimulation appears to exert widespread influence over specific neural networks that are relevant to specific disease entities. In awake patients, activation or suppression of these neural networks can be assessed by either symptom alleviation (i.e., tremor, rigidity, seizures or physiological criteria, which may be predictive of expected symptomatic treatment. Secondary verification of network activation through specific biomarkers that are linked to symptomatic disease improvement may be useful for several reasons. For example, these biomarkers could aid optimal intraoperative localization, possibly improve efficacy or efficiency (i.e., reduced power needs, and provide long-term adaptive automatic adjustment of stimulation parameters. Possible biomarkers for use in portable or implanted devices span from ongoing physiological brain activity, evoked local field potentials (LFPs, and intermittent pathological activity, to wearable devices, biochemical, blood flow, optical, or magnetic resonance imaging (MRI changes, temperature changes, or optogenetic signals. First, however, potential biomarkers must be correlated directly with symptom or disease treatment and network activation. Although numerous biomarkers are under consideration for a variety of stimulation indications the feasibility of these approaches has yet to be fully determined. Particularly, there are critical questions whether the use of adaptive systems can improve efficacy over continuous stimulation, facilitate adjustment of stimulation interventions and improve our understanding of the role of abnormal network function in disease mechanisms.

  14. Comparison of early gestational development between natural and stimulated pregnancies

    International Nuclear Information System (INIS)

    Jun, Soon Ae; Ahn, M. O.; Yoon, T. K.; Cha, G. Y.

    1990-01-01

    In order to assess the difference in growth and development between the stimulated and natural pregnancies, we compared the sonographic measurement of early embryos from the fifth to seventh gestational week, in terms of mean size of gestational sac, crown rump length, fetal heart rate and yolk sac size between 26 ovulation stimulated pregnancies and 38 natural pre gnancies. The two groups were compared by multiple regression analysis, The data suggest that there is attend that embryos smaller in stimulated pregnancies though significant statistical differences was not proved

  15. Augmentation of Fear Extinction by Transcranial Direct Current Stimulation (tDCS

    Directory of Open Access Journals (Sweden)

    Natalie Dittert

    2018-04-01

    Full Text Available Although posttraumatic stress disorder (PTSD; DSM-V 309.82 and anxiety disorders (DSM-V 300.xx are widely spread mental disorders, the effectiveness of their therapy is still unsatisfying. Non-invasive brain-stimulation techniques like transcranial direct current stimulation (tDCS might be an option to improve extinction learning, which is a main functional factor of exposure-based therapy for anxiety disorders. To examine this hypothesis, we used a fear conditioning paradigm with female faces as conditioned stimuli (CS and a 95-dB female scream as unconditioned stimulus (UCS. We aimed to perform a tDCS of the ventromedial prefrontal cortex (vmPFC, which is mainly involved in the control of extinction-processes. Therefore, we applied two 4 × 4 cm electrodes approximately at the EEG-positions F7 and F8 and used a direct current of 1.5 mA. The 20-min stimulation was started during a 10-min break between acquisition and extinction and went on overall extinction-trials. The healthy participants were randomly assigned in two double-blinded process into two sham stimulation and two verum stimulation groups with opposite current flow directions. To measure the fear reactions, we used skin conductance responses (SCR and subjective ratings. We performed a generalized estimating equations model for the SCR to assess the impact of tDCS and current flow direction on extinction processes for all subjects that showed a successful conditioning (N = 84. The results indicate that tDCS accelerates early extinction processes with a significantly faster loss of CS+/CS– discrimination. The discrimination loss was driven by a significant decrease in reaction toward the CS+ as well as an increase in reaction toward the CS– in the tDCS verum groups, whereas the sham groups showed no significant reaction changes during this period. Therefore, we assume that tDCS of the vmPFC can be used to enhance early extinction processes successfully. But before it should be

  16. THE AVAILABILITY AND PORTRAYAL OF STIMULANTS OVER THE INTERNET

    Science.gov (United States)

    Schepis, Ty S.; Marlowe, Douglas B.; Forman, Robert F.

    2008-01-01

    Purpose To quantify the online availability and portrayal of amphetamine-class prescription stimulants with a focus on those medications commonly prescribed to and abused by adolescents. Methods The Google™ search engine was used in searches to assess the frequency of websites offering to sell controlled stimulants (retail sites) or websites that directly linked to retail sites (portal sites). Also, separate searches evaluated the portrayal of controlled prescription stimulants by the initial 20 websites returned by Google™. Retail and portal website frequency was collected for each search. For searches measuring the portrayal of stimulants, webpages were categorized as pro-abuse, anti-abuse, neutral or other, based on set criteria. Results Sites offering to sell stimulants without a prescription were found for nearly all search terms. Across all searches, the Schedule III stimulants indicated for the treatment of obesity returned more sites offering to sell stimulants without a prescription than Schedule II stimulants indicated for the treatment of ADHD. Internet site portrayal of each stimulant varied. However, sites that contained “methamphetamine” often included anti-abuse information. Discussion The apparent availability of stimulants over the Internet without a prescription indicates the potential for a significant public health problem. The extent to which teens are obtaining these drugs via the Internet remains unclear, but clinicians must be aware of the potential for abuse, concomitant prescription use issues, illicit sources, and diversion of these highly addictive medications. Education of consumers and physicians as well as further governmental interventions is needed to limit the potential scope of this problem. PMID:18407040

  17. Vagus nerve stimulation magnet activation for seizures: a critical review.

    Science.gov (United States)

    Fisher, R S; Eggleston, K S; Wright, C W

    2015-01-01

    Some patients receiving VNS Therapy report benefit from manually activating the generator with a handheld magnet at the time of a seizure. A review of 20 studies comprising 859 subjects identified patients who reported on-demand magnet mode stimulation to be beneficial. Benefit was reported in a weighted average of 45% of patients (range 0-89%) using the magnet, with seizure cessation claimed in a weighted average of 28% (range 15-67%). In addition to seizure termination, patients sometimes reported decreased intensity or duration of seizures or the post-ictal period. One study reported an isolated instance of worsening with magnet stimulation (Arch Pediatr Adolesc Med, 157, 2003 and 560). All of the reviewed studies assessed adjunctive magnet use. No studies were designed to provide Level I evidence of efficacy of magnet-induced stimulation. Retrospective analysis of one pivotal randomized trial of VNS therapy showed significantly more seizures terminated or improved in the active stimulation group vs the control group. Prospective, controlled studies would be required to isolate the effect and benefit of magnet mode stimulation and to document that the magnet-induced stimulation is the proximate cause of seizure reduction. Manual application of the magnet to initiate stimulation is not always practical because many patients are immobilized or unaware of their seizures, asleep or not in reach of the magnet. Algorithms based on changes in heart rate at or near the onset of the seizure provide a methodology for automated responsive stimulation. Because literature indicates additional benefits from on-demand magnet mode stimulation, a potential role exists for automatic activation of stimulation. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Subthalamic stimulation modulates cortical motor network activity and synchronization in Parkinson’s disease

    Science.gov (United States)

    Klotz, Rosa; Govindan, Rathinaswamy B.; Scholten, Marlieke; Naros, Georgios; Ramos-Murguialday, Ander; Bunjes, Friedemann; Meisner, Christoph; Plewnia, Christian; Krüger, Rejko

    2015-01-01

    Dynamic modulations of large-scale network activity and synchronization are inherent to a broad spectrum of cognitive processes and are disturbed in neuropsychiatric conditions including Parkinson’s disease. Here, we set out to address the motor network activity and synchronization in Parkinson’s disease and its modulation with subthalamic stimulation. To this end, 20 patients with idiopathic Parkinson’s disease with subthalamic nucleus stimulation were analysed on externally cued right hand finger movements with 1.5-s interstimulus interval. Simultaneous recordings were obtained from electromyography on antagonistic muscles (right flexor digitorum and extensor digitorum) together with 64-channel electroencephalography. Time-frequency event-related spectral perturbations were assessed to determine cortical and muscular activity. Next, cross-spectra in the time-frequency domain were analysed to explore the cortico-cortical synchronization. The time-frequency modulations enabled us to select a time-frequency range relevant for motor processing. On these time-frequency windows, we developed an extension of the phase synchronization index to quantify the global cortico-cortical synchronization and to obtain topographic differentiations of distinct electrode sites with respect to their contributions to the global phase synchronization index. The spectral measures were used to predict clinical and reaction time outcome using regression analysis. We found that movement-related desynchronization of cortical activity in the upper alpha and beta range was significantly facilitated with ‘stimulation on’ compared to ‘stimulation off’ on electrodes over the bilateral parietal, sensorimotor, premotor, supplementary-motor, and prefrontal areas, including the bilateral inferior prefrontal areas. These spectral modulations enabled us to predict both clinical and reaction time improvement from subthalamic stimulation. With ‘stimulation on’, interhemispheric cortico

  19. Shaping pseudoneglect with transcranial cerebellar direct current stimulation and music listening

    Directory of Open Access Journals (Sweden)

    Silvia ePicazio

    2015-03-01

    Full Text Available Non-invasive brain stimulation modulates cortical excitability depending on the initial activation state of the structure being stimulated. Combination of cognitive with neurophysiological stimulations has been successfully employed to modulate responses of specific brain regions. The present research combined a neurophysiological pre-conditioning with a cognitive conditioning stimulation to modulate behavior. We applied this new state-dependency approach to investigate the cerebellar role in musical and spatial information processing, given that a link between musical perception and visuo-spatial abilities and a clear cerebellar involvement in music perception and visuo-spatial tasks have been reported. Cathodal, anodal or sham transcranial cerebellar Direct Current Stimulation (tcDCS pre-conditioning was applied on the left cerebellar hemisphere followed by conditioning stimulation through music or white noise listening in a sample of healthy subjects performing a Line Bisection Task (LBT. The combination of the cathodal stimulation with music listening resulted in a marked attentional shift toward the right hemispace, compensating thus the natural leftward bias of the baseline condition (pseudoneglect. Conversely, the anodal or sham pre-conditioning stimulations combined with either music and white noise conditioning listening did not modulate spatial attention. The efficacy of the combined stimulation (cathodal pre-conditioning and music conditioning and the absence of any effect of the single stimulations provide a strong support to the state-dependency theory. They propose that tcDCS in combination with music listening could act as a rehabilitative tool to improve cognitive functions in the presence of neglect or other spatial disorders.

  20. Testosterone Suppression of CRH-stimulated Cortisol in Men

    OpenAIRE

    Rubinow, David R.; Roca, Catherine A.; Schmidt, Peter J.; Danaceau, Merry A.; Putnam, Karen; Cizza, Giovanni; Chrousos, George; Nieman, Lynnette

    2005-01-01

    Despite observations of age-dependent sexual dimorphisms in hypothalamic-pituitary-adrenal (HPA) axis activity, the role of androgens in the regulation of HPA axis activity in men has not been examined. We assessed this role by performing CRH stimulation tests in ten men (ages 18–45) during gonadal suppression with leuprolide acetate and during testosterone addition to leuprolide. CRH-stimulated cortisol levels as well as peak cortisol and greatest cortisol excursion were significantly lower ...

  1. Biceps brachii muscle oxygenation in electrical muscle stimulation.

    Science.gov (United States)

    Muthalib, Makii; Jubeau, Marc; Millet, Guillaume Y; Maffiuletti, Nicola A; Ferrari, Marco; Nosaka, Kazunori

    2010-09-01

    The purpose of this study was to compare between electrical muscle stimulation (EMS) and maximal voluntary (VOL) isometric contractions of the elbow flexors for changes in biceps brachii muscle oxygenation (tissue oxygenation index, TOI) and haemodynamics (total haemoglobin volume, tHb = oxygenated-Hb + deoxygenated-Hb) determined by near-infrared spectroscopy (NIRS). The biceps brachii muscle of 10 healthy men (23-39 years) was electrically stimulated at high frequency (75 Hz) via surface electrodes to evoke 50 intermittent (4-s contraction, 15-s relaxation) isometric contractions at maximum tolerated current level (EMS session). The contralateral arm performed 50 intermittent (4-s contraction, 15-s relaxation) maximal voluntary isometric contractions (VOL session) in a counterbalanced order separated by 2-3 weeks. Results indicated that although the torque produced during EMS was approximately 50% of VOL (P<0.05), there was no significant difference in the changes in TOI amplitude or TOI slope between EMS and VOL over the 50 contractions. However, the TOI amplitude divided by peak torque was approximately 50% lower for EMS than VOL (P<0.05), which indicates EMS was less efficient than VOL. This seems likely because of the difference in the muscles involved in the force production between conditions. Mean decrease in tHb amplitude during the contraction phases was significantly (P<0.05) greater for EMS than VOL from the 10th contraction onwards, suggesting that the muscle blood volume was lower in EMS than VOL. It is concluded that local oxygen demand of the biceps brachii sampled by NIRS is similar between VOL and EMS.

  2. Electrical stimulation and motor recovery.

    Science.gov (United States)

    Young, Wise

    2015-01-01

    In recent years, several investigators have successfully regenerated axons in animal spinal cords without locomotor recovery. One explanation is that the animals were not trained to use the regenerated connections. Intensive locomotor training improves walking recovery after spinal cord injury (SCI) in people, and >90% of people with incomplete SCI recover walking with training. Although the optimal timing, duration, intensity, and type of locomotor training are still controversial, many investigators have reported beneficial effects of training on locomotor function. The mechanisms by which training improves recovery are not clear, but an attractive theory is available. In 1949, Donald Hebb proposed a famous rule that has been paraphrased as "neurons that fire together, wire together." This rule provided a theoretical basis for a widely accepted theory that homosynaptic and heterosynaptic activity facilitate synaptic formation and consolidation. In addition, the lumbar spinal cord has a locomotor center, called the central pattern generator (CPG), which can be activated nonspecifically with electrical stimulation or neurotransmitters to produce walking. The CPG is an obvious target to reconnect after SCI. Stimulating motor cortex, spinal cord, or peripheral nerves can modulate lumbar spinal cord excitability. Motor cortex stimulation causes long-term changes in spinal reflexes and synapses, increases sprouting of the corticospinal tract, and restores skilled forelimb function in rats. Long used to treat chronic pain, motor cortex stimuli modify lumbar spinal network excitability and improve lower extremity motor scores in humans. Similarly, epidural spinal cord stimulation has long been used to treat pain and spasticity. Subthreshold epidural stimulation reduces the threshold for locomotor activity. In 2011, Harkema et al. reported lumbosacral epidural stimulation restores motor control in chronic motor complete patients. Peripheral nerve or functional electrical

  3. Psychophysical Evaluation of Subdermal Electrical Stimulation in Relation to Prosthesis Sensory Feedback.

    Science.gov (United States)

    Geng, Bo; Dong, Jian; Jensen, Winnie; Dosen, Strahinja; Farina, Dario; Kamavuako, Ernest Nlandu

    2018-03-01

    This paper evaluated the psychophysical properties of subdermal electrical stimulation to investigate its feasibility in providing sensory feedback for limb prostheses. The detection threshold (DT), pain threshold (PT), just noticeable difference (JND), as