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Sample records for activity level-dependent synapse-specific

  1. Synapse-specific stabilization of plasticity processes: the synaptic tagging and capture hypothesis revisited 10 years later.

    Barco, Angel; Lopez de Armentia, Mikel; Alarcon, Juan M

    2008-01-01

    A decade ago, the synaptic tagging hypothesis was proposed to explain how newly synthesized plasticity products can be specifically targeted to active synapses. A growing number of studies have validated the seminal findings that gave rise to this model, as well as contributed to unveil and expand the range of mechanisms underlying late-associativity and neuronal computation. Here, we will review what it was learnt during this past decade regarding the cellular and molecular mechanisms underlying synaptic tagging and synaptic capture. The accumulated experimental evidence has widened the theoretical framework set by the synaptic tagging and capture (STC) model and introduced concepts that were originally considered part of alternative models for explaining synapse-specific long-term potentiation (LTP). As a result, we believe that the STC model, now improved and expanded with these new ideas and concepts, still represents the most compelling hypothesis to explain late-associativity in synapse-specific plasticity processes. We will also discuss the impact of this model in our view of the integrative capability of neurons and associative learning. PMID:18281094

  2. Synapse-specific inhibitory control of hippocampal feedback inhibitory circuit

    Simon eChamberland

    2010-10-01

    Full Text Available Local circuit and long-range GABAergic projections provide powerful inhibitory control over the operation of hippocampal inhibitory circuits, yet little is known about the input- and target-specific organization of interacting inhibitory networks in relation to their specific functions. Using a combination of two-photon laser scanning photostimulation and whole-cell patch clamp recordings in mice hippocampal slices, we examined the properties of transmission at GABAergic synapses formed onto hippocampal CA1 stratum oriens – lacunosum moleculare (O–LM interneurons by two major inhibitory inputs: local projection originating from stratum radiatum interneurons and septohippocampal GABAergic terminals. Optical mapping of local inhibitory inputs to O–LM interneurons revealed that vasoactive intestinal polypeptide- and calretinine-positive neurons, with anatomical properties typical of type III interneuron-specific interneurons, provided the major local source of inhibition to O–LM cells. Inhibitory postsynaptic currents evoked by minimal stimulation of this input exhibited small amplitude and significant paired-pulse and multiple-pulse depression during repetitive activity. Moreover, these synapses failed to show any form of long-term synaptic plasticity. In contrast, synapses formed by septohippocampal projection produced higher amplitude and persistent inhibition and exhibited long-term potentiation induced by theta-like activity. These results indicate the input and target-specific segregation in inhibitory control, exerted by two types of GABAergic projections and responsible for distinct dynamics of inhibition in O–LM interneurons. The two inputs are therefore likely to support the differential activity- and brain state-dependent recruitment of hippocampal feedback inhibitory circuits in vivo, crucial for dendritic disinhibition and computations in CA1 pyramidal cells.

  3. Multi-regional investigation of the relationship between functional MRI blood oxygenation level dependent (BOLD activation and GABA concentration.

    Ashley D Harris

    Full Text Available Several recent studies have reported an inter-individual correlation between regional GABA concentration, as measured by MRS, and the amplitude of the functional blood oxygenation level dependent (BOLD response in the same region. In this study, we set out to investigate whether this coupling generalizes across cortex. In 18 healthy participants, we performed edited MRS measurements of GABA and BOLD-fMRI experiments using regionally related activation paradigms. Regions and tasks were the: occipital cortex with a visual grating stimulus; auditory cortex with a white noise stimulus; sensorimotor cortex with a finger-tapping task; frontal eye field with a saccade task; and dorsolateral prefrontal cortex with a working memory task. In contrast to the prior literature, no correlation between GABA concentration and BOLD activation was detected in any region. The origin of this discrepancy is not clear. Subtle differences in study design or insufficient power may cause differing results; these and other potential reasons for the discrepant results are discussed. This negative result, although it should be interpreted with caution, has a larger sample size than prior positive results, and suggests that the relationship between GABA and the BOLD response may be more complex than previously thought.

  4. GA-Binding Protein Is Dispensable for Neuromuscular Synapse Formation and Synapse-Specific Gene Expression▿

    Jaworski, Alexander; Smith, Cynthia L.; Burden, Steven J.

    2007-01-01

    The mRNAs encoding postsynaptic components at the neuromuscular junction are concentrated in the synaptic region of muscle fibers. Accumulation of these RNAs in the synaptic region is mediated, at least in part, by selective transcription of the corresponding genes in synaptic myofiber nuclei. The transcriptional mechanisms that are responsible for synapse-specific gene expression are largely unknown, but an Ets site in the promoter regions of acetylcholine receptor (AChR) subunit genes and o...

  5. Blood oxygenation-level dependent functional MRI in evaluating the selective activation of motor cortexes associated with recovery of motor function in hemiplegic patients with ischemic stroke

    Yuechun Li; Xiaoyan Liu; Guorong Liu; Ying He; Baojun Wang; Furu Liang; Li Wang; Hui Zhang; Jingfen Zhang; Ruiming Li

    2006-01-01

    BACKGROUND: Previous studies about blood oxygenation-level dependent (BOLD) functional MRI (fMRI) have indicated that the poststroke recovery of motor function is accompanied by the selective activation of motor cor texes with high correlation.OBJECTIVE: To evaluate the short-term outcomes after rehabilitative interventions with BOLD fMRI in hemi plegic patients with acute stroke, and analyze the correlation of the excitement of brain function in the passive and active movements of the affected limb with the recovery of motor function. DESIGN : A case observation. SETTING: Department of Neurology, Baotou Central Hospital. PARTICIPANTS: Thirty hemiplegic inpatients with ischemic stroke were selected from the Department of Neurology, Baotou Central Hospital from January to December in 2005, including 16 males and 14 females, aging 44-71 years with an average age of (56±5) years, and the disease course ranged from 12 to 72 hours. Inclusive criteria: In accordance with the diagnostic standard of ischemic stroke revised by the Fourth National Academic Meeting for Cerebrovascular Disease; Confirmed by cranial CT or MRI. They were all informed agreed with the detected items.METHODS: ① The Bobath technique was adopted in the rehabilitative interventions of the 30 patients, 30 minutes for each time, twice a day for three weeks continuously. ② The hand motor recovery of the stroke patients was graded by the Brunnstrom,stages ( Ⅰ -Ⅵ), and be able to grasp various objects and extend for the whole range was taken as grade Ⅵ. ③ The patients were examined with fMRI BOLD before rehabilitation and 3 weeks after rehabilitation. All the patients were trained with finger movements, the distracting thoughts should be eliminated as much as possible especially during the movement phase, the patients should highly concentrate on the hand movements. The range for the finger movements should be as large as possible with moderate frequency. The hand movements should be 10 s with

  6. Synapse-Specific Metaplasticity: To Be Silenced Is Not to Silence 2B

    Philpot, Benjamin D.; Zukin, R. Suzanne

    2010-01-01

    What happens to a single, presynaptically quiescent synapse among a population of active synapses? In this issue of Neuron, Ehlers and colleagues show that, far from being eliminated, these inactive synapses are primed for potentiation and incorporation into a new neural circuit through an upregulation of NR2B-containing NMDA receptors.

  7. Blood oxygenation level dependent (BOLD). Renal imaging. Concepts and applications

    Many renal diseases as well as several pharmacons cause a change in renal blood flow and/or renal oxygenation. The blood oxygenation level dependent (BOLD) imaging takes advantage of local field inhomogeneities and is based on a T2*-weighted sequence. BOLD is a non-invasive method allowing an estimation of the renal, particularly the medullary oxygenation, and an indirect measurement of blood flow without administration of contrast agents. Thus, effects of different drugs on the kidney and various renal diseases can be controlled and observed. This work will provide an overview of the studies carried out so far and identify ways how BOLD can be used in clinical studies. (orig.)

  8. Blood oxygenation level-dependent response to intragastric load of corn oil emulsion in conscious rats.

    Tsurugizawa, Tomokazu; Uematsu, Akira; Uneyama, Hisayuki; Torii, Kunio

    2009-12-01

    The postingestive actions after intragastric or oronasal stimulation of fat have been well investigated. The blood oxygenation level-dependent (BOLD) signal changes, however, after intragastric load of corn oil emulsion have yet to be elucidated. Here, using functional magnetic resonance imaging, we investigated the BOLD signal response to gut corn oil emulsion in nonanesthetized rats. Intragastrically infused 7% corn oil emulsion induced a BOLD signal increase in several brain regions, including the bilateral amygdala, hippocampus and the ventral tegmental area. These results indicate that the limbic system responds to gut corn oil emulsion and that activation of this system could promote the reinforcing action for food with high fat content. PMID:19918206

  9. Functional neuroanatomy in depressed patients with sexual dysfunction: blood oxygenation level dependent functional MR imaging

    To demonstrate the functional neuroanatomy associated with sexual arousal visually evoked in depressed males who have underlying sexual dysfunction using Blood Oxygenation Level Dependent-based fMRI. Ten healthy volunteers (age range 21-55: mean 32.5 years), and 10 depressed subjects (age range 23-51: mean 34.4 years, mean Beck Depression Inventory score of 39.6 ± 5.9, mean Hamilton Rating Scale Depression (HAMD)-17 score of 33.5 ± 6.0) with sexual arousal dysfunction viewed erotic and neutral video films during functional magnetic resonance imaging (fMRI) with 1.5 T MR scanner (GE Signa Horizon). The fMRI data were obtained from 7 oblique planes using gradient-echo EPI (flip angle/TR/TE=90 .deg. /6000 ms/50 ms). The visual stimulation paradigm began with 60 sec of black screen, 150 sec of neutral stimulation with a documentary video film, 30 sec of black screen, 150 sec of sexual stimulation with an erotic video film followed by 30 sec of black screen. The brain activation maps and their quantification were analyzed by SPM99 program. There was a significant difference of brain activation between two groups during visual sexual stimulation. In depressed subjects, the level of activation during the visually evoked sexual arousal was significantly less than that of healthy volunteers, especially in the cerebrocortical areas of the hypothalamus, thalamus, caudate nucleus, and inferior and superior temporal gyri. On the other hand, the cerebral activation patterns during the neutral condition in both groups showed no significant differences (ρ < 0.01). This study is the first demonstration of the functional neuroanatomy of the brain associated with sexual dysfunction in depressed patients using fMRI. In order to validate our physiological neuroscience results, further studies that would include patients with other disorders and sexual dysfunction, and depressed patients without sexual dysfunction and their treatment response are needed

  10. Functional neuroanatomy in depressed patients with sexual dysfunction: blood oxygenation level dependent functional MR imaging

    Yang, Jong Chul [Chonnam National Univ. Hospital, Kwangju (Korea, Republic of)

    2004-06-15

    To demonstrate the functional neuroanatomy associated with sexual arousal visually evoked in depressed males who have underlying sexual dysfunction using Blood Oxygenation Level Dependent-based fMRI. Ten healthy volunteers (age range 21-55: mean 32.5 years), and 10 depressed subjects (age range 23-51: mean 34.4 years, mean Beck Depression Inventory score of 39.6 {+-} 5.9, mean Hamilton Rating Scale Depression (HAMD)-17 score of 33.5 {+-} 6.0) with sexual arousal dysfunction viewed erotic and neutral video films during functional magnetic resonance imaging (fMRI) with 1.5 T MR scanner (GE Signa Horizon). The fMRI data were obtained from 7 oblique planes using gradient-echo EPI (flip angle/TR/TE=90 .deg. /6000 ms/50 ms). The visual stimulation paradigm began with 60 sec of black screen, 150 sec of neutral stimulation with a documentary video film, 30 sec of black screen, 150 sec of sexual stimulation with an erotic video film followed by 30 sec of black screen. The brain activation maps and their quantification were analyzed by SPM99 program. There was a significant difference of brain activation between two groups during visual sexual stimulation. In depressed subjects, the level of activation during the visually evoked sexual arousal was significantly less than that of healthy volunteers, especially in the cerebrocortical areas of the hypothalamus, thalamus, caudate nucleus, and inferior and superior temporal gyri. On the other hand, the cerebral activation patterns during the neutral condition in both groups showed no significant differences ({rho} < 0.01). This study is the first demonstration of the functional neuroanatomy of the brain associated with sexual dysfunction in depressed patients using fMRI. In order to validate our physiological neuroscience results, further studies that would include patients with other disorders and sexual dysfunction, and depressed patients without sexual dysfunction and their treatment response are needed.

  11. Evaluation by industrial workers of passive and level-dependent hearing protection devices

    Jennifer B Tufts

    2011-01-01

    Full Text Available Level-dependent hearing protection devices (HPDs provide protection from intense sound, while offering amplification for speech and other signals in lower levels of noise. These HPDs have been developed in response to the communication and operational needs of noise-exposed persons in industry and the military. This study was conducted to examine industrial workers′ perceptions of the performance of two level-dependent HPDs (one with integrated radio communication capability and one without it and their customary passive HPDs. This research took place at a plastic film manufacturing plant in Rhode Island, USA, following a mixed-measures design. Fifteen maintenance technicians at the plant evaluated the two level-dependent HPDs, plus their customary passive HPDs, in three separate trial periods. Data were collected via a questionnaire designed for this purpose. Mixed-model analyses of variance were performed on all dependent measures. Linear and quadratic effect sizes were assessed with eta. Results revealed that the two level-dependent HPDs offered better perceived communication and situational awareness than the workers′ customary passive HPDs. However, the level-dependent HPDs were rated lower than the passive HPDs in terms of usability and comfort. To increase workers′ acceptance of level-dependent HPDs, usability issues must be addressed by the HPD manufacturers.

  12. On the level-dependence of Wess-Zumino-Witten three-point functions

    Rasmussen, Jørgen; Walton, Mark A.

    2001-01-01

    Three-point functions of Wess-Zumino-Witten models are investigated. In particular, we study the level-dependence of three-point functions in the models based on algebras $su(3)$ and $su(4)$. We find a correspondence with Berenstein-Zelevinsky triangles. Using previous work connecting those triangles to the fusion multiplicities, and the Gepner-Witten depth rule, we explain how to construct the full three-point functions. We show how their level-dependence is similar to that of the related fu...

  13. Application of language blood oxygenation level dependent functional MRI in the navigating operation of neurosurgery

    Objective: To verify the accuracy of blood oxygenation level dependent (BOLD)-based activation using electrocortical stimulation mapping (ESM) and explore the value of language fMRI in the navigating operation of neurosurgery. Methods: In 8 cases with brain tumors, BOLD-fMRI examinations were done before the operations. Under the state of awake anesthesia,the patients were aroused and ESM was conducted. Point-to-point comparison between the BOLD signal activations and the ESM was carried out under the surveillance of the neuro-navigation technology. In order to observe the sensibility and specificity of BOLD activations, the location of BOLD activations and the point of ESM was compared to calculate the stimulating positive points inside the regions of BOLD signals (real positive), outside BOLD regions (pseudo- negative), the stimulating negative points inside the regions of BOLD signals (pseudo-positive), and outside BOLD region (real negative). Two kinds of criteria for assessment were used. One was that the positive stimulating points were located in BOLD regions, and the other was that the positive stimulating points were located within 1 cm around the range of BOLD regions. Removal of the lesions were conducted with the tissue 1 cm around the language region preserved, and the cortex inside 0.5-1.0 cm distance from the positive points were retained. Results: Of the 8 cases, only 6 finished the tasks. Among them, 3 cases were with astrocytoma of grade 2, 2 were with astrocytoma of grade 3, and one with glioblastoma. The total number of stimulating points was 48, among which the positive points were 11. When the first criteria was applied, the sensitivity was 72.7% (8/11), and the specificity was 81.8% (30/37). When the second criteria was applied, the sensitivity was 82.0% (9/11), and the specificity was 75.6% (28/37). Follow-up after operation showed no aphasia occurred. Conclusions: BOLD-fMRI had a high sensitivity and specificity in displaying the language

  14. Modelling the level-dependent latency of the auditory brainstem response

    Rønne, Filip Munch; Dau, Torsten; Harte, James;

    2011-01-01

    Auditory brainstem responses (ABR) are used for both clinical and research purposes to objectively assess human hearing. A prominent feature of the transient evoked ABR is the level-dependent latency of the distinct peaks in its waveform. The latency of the most prominent peak, wave-V, is about 8...

  15. Blood oxygenation level dependent (BOLD). Renal imaging. Concepts and applications; Blood Oxygenation Level Dependent (BOLD). Bildgebung der Nieren. Konzepte und Anwendungen

    Nissen, Johanna C.; Haneder, Stefan; Schoenberg, Stefan O.; Michaely, Henrik J. [Heidelberg Univ. Medizinische Fakultaet Mannheim (Germany). Inst. fuer Klinische Radiologie und Nuklearmedizin; Mie, Moritz B.; Zoellner, Frank G. [Heidelberg Univ. Medizinische Fakultaet Mannheim (DE). Inst. fuer Computerunterstuetzte Klinische Medizin (CKM)

    2010-07-01

    Many renal diseases as well as several pharmacons cause a change in renal blood flow and/or renal oxygenation. The blood oxygenation level dependent (BOLD) imaging takes advantage of local field inhomogeneities and is based on a T2{sup *}-weighted sequence. BOLD is a non-invasive method allowing an estimation of the renal, particularly the medullary oxygenation, and an indirect measurement of blood flow without administration of contrast agents. Thus, effects of different drugs on the kidney and various renal diseases can be controlled and observed. This work will provide an overview of the studies carried out so far and identify ways how BOLD can be used in clinical studies. (orig.)

  16. A novel function for serotonin-mediated short-term facilitation in Aplysia: Conversion of a transient, cell-wide homosynaptic Hebbian plasticity into a persistent, protein synthesis-independent synapse-specific enhancement

    Bailey, Craig H.; Giustetto, Maurizio; Zhu, Hiuxiang; Chen, Mary; Kandel, Eric R.

    2000-01-01

    Studies of sensitization and classical conditioning of the gill-withdrawal reflex in Aplysia have shown that the synaptic connections between identified glutamatergic sensory neurons and motor neurons can be enhanced in one of two ways: by a heterosynaptic (modulatory input-dependent) mechanism that gives rise with repetition to long-term facilitation and by a homosynaptic (activity-dependent) mechanism that gives rise with repetition to a facilitation that is part...

  17. Increased regional homogeneity of blood oxygen level-dependent signals in occipital cortex of early blind individuals.

    Liu, Chong; Liu, Yong; Li, Weilan; Wang, Dawei; Jiang, Tianzi; Zhang, Yunting; Yu, Chunshui

    2011-03-01

    Although resting-state functional magnetic resonance imaging has shown altered functional connectivity between visual and other brain areas in the early blind individuals, it cannot answer which brain area's local activities are changed. In this study, regional homogeneity, a measure of the homogeneity of the local blood oxygen level-dependent signals, was used for the first time to investigate the changes in the resting-state brain activity in the early blind individuals. Compared with age-matched and sex-matched sighted individuals, the early blind individuals showed increased regional homogeneity only in the occipital areas, which might be explained by the abnormal cortical development and/or experience-dependent plasticity, resulted from an early visual deprivation. PMID:21304328

  18. Inventory management for dual sales channels with inventory-level-dependent demand

    Tingting Li; Xiaobo Zhao; Jinxing Xie

    2015-01-01

    This paper studies the inventory management problem of dual channels operated by one vendor. Demands of dual channels are inventory-level-dependent. We propose a multi-period stochastic dynamic programming model which shows that under mild conditions, the myopic inventory policy is optimal for the infinite horizon problem. To investigate the importance of capturing demand dependency on inventory levels, we consider a heuristic where the vendor ignores demand dependency on inventory levels, an...

  19. Blood oxygenation level-dependent MRI for assessment of renal oxygenation

    Neugarten J; Golestaneh L

    2014-01-01

    Joel Neugarten, Ladan Golestaneh Renal Division, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, USA Abstract: Blood oxygen level-dependent magnetic resonance imaging (BOLD MRI) has recently emerged as an important noninvasive technique to assess intrarenal oxygenation under physiologic and pathophysiologic conditions. Although this tool represents a major addition to our armamentarium of methodologies to investigate the role of hypoxia in the pathogenesis of acute...

  20. Derivative Asset Analysis in Models with Level-Dependent and Stochastic Volatility

    Frey, R.

    1997-01-01

    In this survey we discuss models with level-dependent and stochastic volatility from the viewpoint of erivative asset analysis. Both classes of models are generalisations of the classical Black-Scholes model; they have been developed in an effort to build models that are flexible enough to cope with the known deficits of the classical Black-Scholes model. We start by briefly recalling the standard theory for pricing and hedging derivatives in complete frictionless markets and the classical Bl...

  1. Optimal production policy for multi-product with inventory-level-dependent demand in segmented market

    Singh Yogender

    2013-01-01

    Full Text Available Market segmentation has emerged as the primary means by which firms achieve optimal production policy. In this paper, we use market segmentation approach in multi-product inventory system with inventory-level-dependent demand. The objective is to make use of optimal control theory to solve the inventory-production problem and develop an optimal production policy that minimizes the total cost associated with inventory and production rate in segmented market. First, we consider a single production and inventory problem with multi-destination demand that vary from segment to segment. Further, we describe a single source production and multi destination inventory and demand problem under the assumption that firm may choose independently the inventory directed to each segment. The optimal control is applied to study and solve the proposed problem.

  2. Fermi level dependence of Moessbauer spectroscopic components corresponding to iron interstitials and their clusters in silicon

    57Fe deposited p- and n-type float-zone Si are studied by high temperature Moessbauer spectroscopy. After the deposition the spectra obtained at room temperature indicate that 57Fe atoms are migrating already, and forming the components due to interstitial, substitutional Fe and other clusters in Si. A measurement, i.e., simultaneously an annealing at 1273 K for about 10 days leads further to the diffusion of 57Fe atoms into a deeper part of the matrix. The spectra depend not only on the dopants and their concentrations, but also on temperature. This Fermi level dependence will provide us information on the charge states of each Fe component in Si matrix, and therefore their energy levels

  3. Preoperative 3T high field blood oxygen level dependent functional magnetic resonance imaging for glioma involving sensory cortical areas

    LI Shao-wu; WANG Jiang-fei; JIANG Tao; LI Shou-wei; ZHANG Wen-bo; LI Zi-xiao; ZHANG Zhong; DAI Jian-ping; WANG Zhong-cheng

    2010-01-01

    Background Localization of sensory cortical areas during the operation is essential to preserve the sensory function.Intraoperative direct electrostimulation under awake anesthesia is the golden standard but time-consuming. We applied 3T high field blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to identify the relationship between glioma and cortical sensory areas preoperatively and to guide intraoperative direct electrostimulation for quick and precise localization.Methods Five glioma patients with sensory cortex involvement by or next to the lesion had preoperative BOLD fMRI to determine the spatial relationship of cortical sensory areas to the tumours. Bilateral hand opposite movement was performed by these patients for fMRI. Precentral and postcentral gyri were identified by electrical stimulation during the operation. Karnofsky Performance Status scores of the patients' pre- and postoperative and the role of BOLD fMRI were evaluated.Results The cortical sensory areas were all activated in five glioma patients involving postcentral gyrus areas by BOLDf MRI with bilateral hand opposite movement. The detected activation areas corresponded with the results from cortical electrical stimulation.Conclusions The relationship between cortical sensory areas and tumour can be accurately shown by BOLD fMRI before operation. And the information used to make the tumour resection could obtain good clinical results.

  4. Blood oxygenation level dependent functional MRI study on the changes of motor cortex in patients with amyotrophic lateral sclerosis

    Objective: To study the changes of motor cortex in patients with amyotrophic lateral sclerosis (ALS) while executing sequential finger tapping movement by using blood oxygenation level dependent (BOLD) functional MRI. Methods: Fifteen patients with definite or probable ALS and 15 age and gender matched normal controls were enrolled in the BOLD study, and all the subjects were right-handed with no other diseases or any recent medication history. A 3.0 T MR scanner' was employed and gradient echo EPI (GRE-EPI)sequence was used to acquire the functional images. Subjects executed sequential finger tapping movement at a frequency of 1-2 Hz during a block design task. fMRI data were analyzed by using statistical parametric mapping (SPM) 2. Volume of activated brain areas was compared with the use of a Student's t-test. Results: Bilateral primary sensorimotor cortex (PSM), bilateral posterior aspect of premotor area (PA), bilateral supplementary motor area (SMA), contralateral inferior lateral premotor area (ILPA), bilateral parietal region (PAR), and ipsilateral cerebellum showed activation in both ALS patients and normal controls when executing the same motor task. The activation areas in bilateral PSM and bilateral posterior aspect of PA ( right hand ipsilateral activation: ALS (924.5±141.1) mm3, control (829.9± 98.4) mm3, P=0.05; right hand contralateral activation: ALS (9143.8±702.8) mm3, control (8638.8±506.4) mm3 P3, control (902.5±3 184.2)mm, P3, control (5934.6±616.4) mm3, P3, control (4710.7±416.3) mm3, P3, control (3688.9±672.3) mm3, P3, control (254.3±84.4) mm3, P3, control (1689.0±719.6) mm3, P<0.05) were significantly larger in ALS patients than in normal controls. Extra activation areas including ipsilateral ILPA, contralateral cerebellum and bilateral posterior limb of internal capsule were only detected in ALS patients. Conclusions: Similar activation areas were seen in both groups while executing the same motor task, but the activated areas

  5. Deciphering phonemes from syllables in blood oxygenation level-dependent signals in human superior temporal gyrus.

    Zhang, Qingtian; Hu, Xiaolin; Luo, Huan; Li, Jianmin; Zhang, Xiaolu; Zhang, Bo

    2016-03-01

    Linguistic units such as phonemes and syllables are important for speech perception. How the brain encodes these units is not well understood. Many neuroimaging studies have found distinct representations of consonant-vowel syllables that shared one phoneme and differed in the other phoneme (e.g. /ba/ and /da/), but it is unclear whether this discrimination ability is due to the neural coding of phonemes or syllables. We combined functional magnetic resonance imaging with multivariate pattern analysis to explore this question. Subjects listened to nine Mandarin syllables in a consonant-vowel form. We successfully decoded phonemes from the syllables based on the blood oxygenation level-dependent signals in the superior temporal gyrus (STG). Specifically, a classifier trained on the cortical patterns elicited by a set of syllables, which contained two phonemes, could distinguish the cortical patterns elicited by other syllables that contained the two phonemes. The results indicated that phonemes have unique representations in the STG. In addition, there was a categorical effect, i.e. the cortical patterns of consonants were similar, and so were the cortical patterns of vowels. Further analysis showed that phonemes exhibited stronger encoding specificity in the mid-STG than in the anterior STG. PMID:26751256

  6. Blood oxygenation level-dependent MRI for assessment of renal oxygenation

    Neugarten J

    2014-11-01

    Full Text Available Joel Neugarten, Ladan Golestaneh Renal Division, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, USA Abstract: Blood oxygen level-dependent magnetic resonance imaging (BOLD MRI has recently emerged as an important noninvasive technique to assess intrarenal oxygenation under physiologic and pathophysiologic conditions. Although this tool represents a major addition to our armamentarium of methodologies to investigate the role of hypoxia in the pathogenesis of acute kidney injury and progressive chronic kidney disease, numerous technical limitations confound interpretation of data derived from this approach. BOLD MRI has been utilized to assess intrarenal oxygenation in numerous experimental models of kidney disease and in human subjects with diabetic and nondiabetic chronic kidney disease, acute kidney injury, renal allograft rejection, contrast-associated nephropathy, and obstructive uropathy. However, confidence in conclusions based on data derived from BOLD MRI measurements will require continuing advances and technical refinements in the use of this technique. Keywords: kidney, hypoxia, oxygenation, diabetes mellitus, chronic kidney disease, acute kidney injury, contrast-associated nephropathy, BOLD MRI

  7. Axial level-dependent molecular and cellular mechanisms underlying the genesis of the embryonic neural plate.

    Kondoh, Hisato; Takada, Shinji; Takemoto, Tatsuya

    2016-06-01

    The transcription factor gene Sox2, centrally involved in neural primordial regulation, is activated by many enhancers. During the early stages of embryonic development, Sox2 is regulated by the enhancers N2 and N1 in the anterior neural plate (ANP) and posterior neural plate (PNP), respectively. This differential use of the enhancers reflects distinct regulatory mechanisms underlying the genesis of ANP and PNP. The ANP develops directly from the epiblast, triggered by nodal signal inhibition, and via the combined action of TFs SOX2, OTX2, POU3F1, and ZIC2, which promotes the the ANP development and inhibits other cell lineages. In contrast, the PNP is derived from neuromesodermal bipotential axial stem cells that develop into the neural plate when Sox2 is activated by the N1 enhancer, whereas they develop into the paraxial mesoderm when the N1 enhancer is repressed by the action of TBX6. The axial stem cells are maintained by the activity of WNT3a and T (Brachyury). However, at axial levels more anterior to the 8th somites (cervical levels), the development of both the neural plate and somite proceeds in the absence of WNT3a, T, or TBX6. These observations indicate that distinct molecular and cellular mechanisms determine neural plate genesis based on the axial level, and contradict the classical concept of the term "neural induction," which assumes a pan-neural plate mechanism. PMID:27279156

  8. How bold is blood oxygenation level dependent (BOLD) magnetic resonance imaging of the kidney? Opportunities, challenges and future directions

    Niendorf, T; Pohlmann, A.; Arakelyan, K.; Flemming, B; Cantow, K.; Hentschel, J.; Grosenick, D; Ladwig, M.; Reimann, H; Klix, S.; Waiczies, S; Seeliger, E.

    2015-01-01

    Renal tissue hypoperfusion and hypoxia are key elements in the pathophysiology of acute kidney injury and its progression to chronic kidney disease. Yet, in vivo assessment of renal haemodynamics and tissue oxygenation remains a challenge. Many of the established approaches are invasive, hence not applicable in humans. Blood oxygenation level dependent (BOLD) magnetic resonance imaging (MRI) offers an alternative. BOLD-MRI is non-invasive and indicative of renal tissue oxygenation. Nonetheles...

  9. CO2-level Dependent Effects of Ocean Acidification on Squid, Doryteuthis pealeii, Early Life History

    Zakroff, Casey J.

    2013-12-01

    Ocean acidification is predicted to lead to global oceanic decreases in pH of up to 0.3 units within the next 100 years. However, those levels are already being reached currently in coastal regions due to natural CO2 variability. Squid are a vital component of the pelagic ecosystem, holding a unique niche as a highly active predatory invertebrate and major prey stock for upper trophic levels. This study examined the effects of a range of ocean acidification regimes on the early life history of a coastal squid species, the Atlantic longfin squid, Doryteuthis pealeii. Eggs were raised in a flow-through ocean acidification system at CO2 levels ranging from ambient (400ppm) to 2200ppm. Time to hatching, hatching efficiency, and hatchling mantle lengths, yolk sac sizes, and statoliths were all examined to elucidate stress effects. Delays in hatching time of at least a day were seen at exposures above 1300ppm in all trials under controlled conditions. Mantle lengths were significantly reduced at exposures above 1300 ppm. Yolk sac sizes varied between CO2 treatments, but no distinct pattern emerged. Statoliths were increasingly porous and malformed as CO2 exposures increased, and were significantly reduced in surface area at exposures above 1300ppm. Doryteuthis pealeii appears to be able to withstand acidosis stress without major effects up to 1300ppm, but is strongly impacted past that threshold. Since yolk consumption did not vary among treatments, it appears that during its early life stages, D. pealeii reallocates its available energy budget away from somatic growth and system development in order to mitigate the stress of acidosis.

  10. Megalophallus as a sequela of priapism in sickle cell anemia: use of blood oxygen level-dependent magnetic resonance imaging.

    Kassim, A A; Umans, H; Nagel, R L; Fabry, M E

    2000-09-01

    Priapism is a common complication of sickle cell anemia. We report a little known sequela of priapism: painless megalophallus, with significant penile enlargement. The patient had had an intense episode of priapism 9 years previously and his penis remained enlarged. Blood oxygen level-dependent magnetic resonance imaging revealed enlarged, hypoxic corpora cavernosa. Megalophallus probably resulted from permanent loss of elasticity of the tunica albuginea due to severe engorgement during the episode of priapism. This sequela needs to be recognized by physicians because no intervention is necessary and sexual function seems to remain intact. PMID:10962334

  11. Cerebral misery perfusion diagnosed using hypercapnic blood-oxygenation-level-dependent contrast functional magnetic resonance imaging: a case report

    D'Souza Olympio

    2010-02-01

    Full Text Available Abstract Introduction Cerebral misery perfusion represents a failure of cerebral autoregulation. It is an important differential diagnosis in post-stroke patients presenting with collapses in the presence of haemodynamically significant cerebrovascular stenosis. This is particularly the case when cortical or internal watershed infarcts are present. When this condition occurs, further investigation should be done immediately. Case presentation A 50-year-old Caucasian man presented with a stroke secondary to complete occlusion of his left internal carotid artery. He went on to suffer recurrent seizures. Neuroimaging demonstrated numerous new watershed-territory cerebral infarcts. No source of arterial thromboembolism was demonstrable. Hypercapnic blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging was used to measure his cerebrovascular reserve capacity. The findings were suggestive of cerebral misery perfusion. Conclusions Blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging allows the inference of cerebral misery perfusion. This procedure is cheaper and more readily available than positron emission tomography imaging, which is the current gold standard diagnostic test. The most evaluated treatment for cerebral misery perfusion is extracranial-intracranial bypass. Although previous trials of this have been unfavourable, the results of new studies involving extracranial-intracranial bypass in high-risk patients identified during cerebral perfusion imaging are awaited. Cerebral misery perfusion is an important and under-recognized condition in which emerging imaging and treatment modalities present the possibility of practical and evidence-based management in the near future. Physicians should thus be aware of this disorder and of recent developments in diagnostic tests that allow its detection.

  12. Characterization of the blood-oxygen level-dependent (BOLD) response in cat auditory cortex using high-field fMRI.

    Brown, Trecia A; Joanisse, Marc F; Gati, Joseph S; Hughes, Sarah M; Nixon, Pam L; Menon, Ravi S; Lomber, Stephen G

    2013-01-01

    Much of what is known about the cortical organization for audition in humans draws from studies of auditory cortex in the cat. However, these data build largely on electrophysiological recordings that are both highly invasive and provide less evidence concerning macroscopic patterns of brain activation. Optical imaging, using intrinsic signals or dyes, allows visualization of surface-based activity but is also quite invasive. Functional magnetic resonance imaging (fMRI) overcomes these limitations by providing a large-scale perspective of distributed activity across the brain in a non-invasive manner. The present study used fMRI to characterize stimulus-evoked activity in auditory cortex of an anesthetized (ketamine/isoflurane) cat, focusing specifically on the blood-oxygen-level-dependent (BOLD) signal time course. Functional images were acquired for adult cats in a 7 T MRI scanner. To determine the BOLD signal time course, we presented 1s broadband noise bursts between widely spaced scan acquisitions at randomized delays (1-12 s in 1s increments) prior to each scan. Baseline trials in which no stimulus was presented were also acquired. Our results indicate that the BOLD response peaks at about 3.5s in primary auditory cortex (AI) and at about 4.5 s in non-primary areas (AII, PAF) of cat auditory cortex. The observed peak latency is within the range reported for humans and non-human primates (3-4 s). The time course of hemodynamic activity in cat auditory cortex also occurs on a comparatively shorter scale than in cat visual cortex. The results of this study will provide a foundation for future auditory fMRI studies in the cat to incorporate these hemodynamic response properties into appropriate analyses of cat auditory cortex. PMID:23000258

  13. Blood oxygenation level-dependent MRI of the skeletal muscle during ischemia in patients with peripheral arterial occlusive disease

    Potthast, Silke [Unispital Basel, Inst. fuer Radiologie (Switzerland); Schulte, A. [Univ. Hospital Ulm (Germany). Clinic for Radiation Therapy and Radiooncology; Kos, S.; Bilecen, D. [Unispital Basel, Interventional Radiology (Switzerland); Aschwanden, M. [Unispital Basel (Switzerland). Angiologie

    2009-12-15

    Purpose: to compare calf muscle Blood Oxygenation Level-Dependent (BOLD) response during ischemia in patients suffering from peripheral arterial occlusive disease (PAOD) and age-matched non-PAOD subjects. Materials and methods: PAOD patients with symptoms of intermittent calf claudication and an age-matched control group underwent T2*-weighted single-shot multi-echo planar imaging on a whole-body MR scanner at 1.5 T. The muscle BOLD signal in the calf was acquired during 60 sec of baseline and 240 sec of ischemia induced by cuff compression. T2* time courses in four calf muscles were evaluated. Results: significant differences in the mean T2* values were noted after 150 sec of measurement (p < 0.05). Patients with PAOD revealed a significantly reduced BOLD signal decrease compared to an age-matched control group. Conclusion: potential cause for this observation may be changes in the structure and/or the metabolic turnover of the muscle in PAOD patients. (orig.)

  14. Renal Blood Oxygenation Level-dependent Imaging in Longitudinal Follow-up of Donated and Remaining Kidneys.

    Seif, Maryam; Eisenberger, Ute; Binser, Tobias; Thoeny, Harriet C; Krauer, Fabienne; Rusch, Aurelia; Boesch, Chris; Vogt, Bruno; Vermathen, Peter

    2016-06-01

    Purpose To determine renal oxygenation changes associated with uninephrectomy and transplantation in both native donor kidneys and transplanted kidneys by using blood oxygenation level-dependent (BOLD) MR imaging. Materials and Methods The study protocol was approved by the local ethics committee. Thirteen healthy kidney donors and their corresponding recipients underwent kidney BOLD MR imaging with a 3-T imager. Written informed consent was obtained from each subject. BOLD MR imaging was performed in donors before uninephrectomy and in donors and recipients 8 days, 3 months, and 12 months after transplantation. R2* values, which are inversely related to tissue partial pressure of oxygen, were determined in the cortex and medulla. Longitudinal R2* changes were statistically analyzed by using repeated measures one-way analysis of variance with post hoc pair-wise comparisons. Results R2* values in the remaining kidneys significantly decreased early after uninephrectomy in both the medulla and cortex (P oxygen content. In donors, R2* remained significantly decreased in both the medulla and cortex at 3 (P < .01) and 12 (P < .01) months. In transplanted kidneys, R2* remained stable during the first year after transplantation, with no significant change. Among donors, cortical R2* was found to be negatively correlated with estimated glomerular filtration rate (R = -0.47, P < .001). Conclusion The results suggest that BOLD MR imaging may potentially be used to monitor renal functional changes in both remaining and corresponding transplanted kidneys. (©) RSNA, 2016. PMID:26744926

  15. Blood oxygenation level-dependent MRI of the skeletal muscle during ischemia in patients with peripheral arterial occlusive disease

    Purpose: to compare calf muscle Blood Oxygenation Level-Dependent (BOLD) response during ischemia in patients suffering from peripheral arterial occlusive disease (PAOD) and age-matched non-PAOD subjects. Materials and methods: PAOD patients with symptoms of intermittent calf claudication and an age-matched control group underwent T2*-weighted single-shot multi-echo planar imaging on a whole-body MR scanner at 1.5 T. The muscle BOLD signal in the calf was acquired during 60 sec of baseline and 240 sec of ischemia induced by cuff compression. T2* time courses in four calf muscles were evaluated. Results: significant differences in the mean T2* values were noted after 150 sec of measurement (p < 0.05). Patients with PAOD revealed a significantly reduced BOLD signal decrease compared to an age-matched control group. Conclusion: potential cause for this observation may be changes in the structure and/or the metabolic turnover of the muscle in PAOD patients. (orig.)

  16. Preoperative blood oxygen level-dependent functional magnetic resonance imaging in patients with gliomas involving the motor cortical areas

    XIE Jian; CHEN Xu-zhu; JIANG Tao; LI Shou-wei; LI Zi-xiao; ZHANG Zhong; DAI Jian-ping; WANG Zhong-cheng

    2008-01-01

    Background Blood oxygen level-dependent(BOLD)functional magnetic resonance imaging(fMRI)plays an important role in identifying functional cortical areas of the brain.especially In patients with gliomas.This study aimed to assess the value of fMRI in presurgical planning and functional outcome of patients with gliomas in the motor cortical areas.Methods Twenty-six patients with gliomas in the motor cortex were recruited in the study.Before operation.fMRI was performed in each patient to obtain the mapping of bilateral hands area on the primary sensorimotor cortex.This examination was performed on a 3.0T scanner with a bilateral hands movement paradigm.During microsurgery under awake anesthesia,the motor area was identified using direct electrical stimulation and compared with preoperative mapping.Finally the tumor was resected as much as possible with the motor cortex preserved in each patlent.Karnofsky performance status(KPS)was evaluated in all patients before and after operation.Results Twenty-three patients showed a successful fMRI mapping.Among them,19 were calssified to be grade Ⅲ;4,grade Ⅱ;3,grade Ⅰ.The operation time was about 7 hours in the 23 patients,8.5 hours in the other 3.The pre- and pOstODerative KPS score was 82.3±8.6 and 94.2±8.1,respectively.Conclusions Preoperative fMRI of the hand motor area shows a high consistency with intraoperative cortical electronic stimulation.Combined use of the two methods shows a maximum benefit in surgical treatment.

  17. Vascular Steal Explains Early Paradoxical Blood Oxygen Level-Dependent Cerebrovascular Response in Brain Regions with Delayed Arterial Transit Times

    Julien Poublanc

    2013-04-01

    Full Text Available Introduction: Blood oxygen level-dependent (BOLD magnetic resonance imaging (MRI during manipulation of inhaled carbon dioxide (CO2 can be used to measure cerebrovascular reactivity (CVR and map regions of exhausted cerebrovascular reserve. These regions exhibit a reduced or negative BOLD response to inhaled CO2. In this study, we sought to clarify the mechanism behind the negative BOLD response by investigating its time delay (TD. Dynamic susceptibility contrast (DSC MRI with the injection of a contrast agent was used as the gold standard in order to provide measurement of the blood arrival time to which CVR TD could be compared. We hypothesize that if negative BOLD responses are the result of a steal phenomenon, they should be synchronized with positive BOLD responses from healthy brain tissue, even though the blood arrival time would be delayed. Methods: On a 3-tesla MRI system, BOLD CVR and DSC images were collected in a group of 19 patients with steno-occlusive cerebrovascular disease. For each patient, we generated a CVR magnitude map by regressing the BOLD signal with the end-tidal partial pressure of CO2 (PETCO2, and a CVR TD map by extracting the time of maximum cross-correlation between the BOLD signal and PETCO2. In addition, a blood arrival time map was generated by fitting the DSC signal with a gamma variate function. ROI masks corresponding to varying degrees of reactivity were constructed. Within these masks, the mean CVR magnitude, CVR TD and DSC blood arrival time were extracted and averaged over the 19 patients. CVR magnitude and CVR TD were then plotted against DSC blood arrival time. Results: The results show that CVR magnitude is highly correlated to DSC blood arrival time. As expected, the most compromised tissues with the longest blood arrival time have the lowest (most negative CVR magnitude. However, CVR TD shows a noncontinuous relationship with DSC blood arrival time. CVR TD is well correlated to DSC blood arrival time

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

    Ris, Laurence; Godaux, Emile

    2007-01-01

    Memory shows age-related decline. According to the current prevailing theoretical model, encoding of memories relies on modifications in the strength of the synapses connecting the different cells within a neuronal network. The selective increases in synaptic weight are thought to be biologically implemented by long-term potentiation (LTP). Here,…

  19. Cadherin-9 Regulates Synapse-Specific Differentiation in the Developing Hippocampus

    Williams, Megan E.; Wilke, Scott A.; Daggett, Anthony; Davis, Elizabeth; Otto, Stefanie; Ravi, Deepak; Ripley, Beth; Bushong, Eric A.; Ellisman, Mark H.; Klein, Gerd; Ghosh, Anirvan

    2011-01-01

    Our understanding of mechanisms that regulate the differentiation of specific classes of synapses is limited. Here, we investigate the formation of synapses between hippocampal dentate gyrus (DG) neurons and their target CA3 neurons and find that DG neurons preferentially form synapses with CA3 rather than DG or CA1 neurons in culture, suggesting that specific interactions between DG and CA3 neurons drive synapse formation. Cadherin-9 is expressed selectively in DG and CA3 neurons, and downre...

  20. Angioplasty and stenting for severe vertebral artery oriifce stenosis:effects on cerebellar function remodeling veriifed by blood oxygen level-dependent functional magnetic resonance imaging

    Bo Liu; Zhiwei Li; Peng Xie

    2014-01-01

    Vertebral artery oriifce stenting may improve blood supply of the posterior circulation of the brain to regions such as the cerebellum and brainstem. However, previous studies have mainly focused on recovery of cerebral blood lfow and perfusion in the posterior circulation after inter-ventional therapy. This study examined the effects of functional recovery of local brain tissue on cerebellar function remodeling using blood oxygen level-dependent functional magnetic reso-nance imaging before and after interventional therapy. A total of 40 Chinese patients with severe unilateral vertebral artery oriifce stenosis were enrolled in this study. Patients were equally and randomly assigned to intervention and control groups. The control group received drug treat-ment only. The intervention group received vertebral artery oriifce angioplasty and stenting+identical drug treatment to the control group. At 13 days after treatment, the Dizziness Handicap Inventory score was compared between the intervention and control groups. Cerebellar function remodeling was observed between the two groups using blood oxygen level-dependent function-al magnetic resonance imaging. The improvement in dizziness handicap and cerebellar function was more obvious in the intervention group than in the control group. Interventional therapy for severe vertebral artery oriifce stenosis may effectively promote cerebellar function remodeling and exert neuroprotective effects.

  1. Blood oxygenation level-dependent MR imaging as a predictor of therapeutic response to concurrent chemoradiotherapy in cervical cancer: a preliminary experience

    Kim, Chan Kyo; Park, Sung Yoon; Park, Byung Kwan [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Samsung Medical Center, Seoul (Korea, Republic of); Park, Won; Huh, Seung Jae [Sungkyunkwan University School of Medicine, Department of Radiation Oncology, Samsung Medical Center, Seoul (Korea, Republic of)

    2014-07-15

    To investigate the value of blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) as a predictor of therapeutic response in cervical cancer patients undergoing concurrent chemoradiotherapy (CCRT). Thirty consecutive patients with biopsy-proven cervical cancer were examined by BOLD MRI before (preTx) and after CCRT (postTx). The R2* value (s{sup -1}) was calculated in the tumour and normal myometrium for preTx and postTx studies. Final tumour responses, as determined by changes of tumour size or volume on MRI, were correlated with tumour R2* values at preTx. The mean R2* values of tumours at preTx (21.1) were significantly lower than those at postTx (39.4 s{sup -1}) (p < 0.001), while those of normal myometrium were similar between preTx and postTx (p = 0.363). At preTx, tumour R2* values showed significantly negative correlation with final tumour size response (p = 0.022, Spearman's coefficient = -0.415). However, tumour R2* values at preTx were not associated with final tumour volume response (p = 0.069). BOLD MRI at 3 T, as an imaging biomarker, may have the potential to evaluate therapeutic response in cervical cancers. The association between BOLD MRI findings and CCRT responses warrants further validation. (orig.)

  2. Prognostic Significance of Transverse Relaxation Rate (R2*) in Blood Oxygenation Level-Dependent Magnetic Resonance Imaging in Patients with Invasive Breast Cancer

    Choi, Hye Young; Ko, Eun Sook; Han, Boo-Kyung; Kim, Eun Ju; Kim, Sun Mi; Lim, Yaeji; Kim, Rock Bum

    2016-01-01

    Objective To examine the relationship between magnetic resonance transverse relaxation rate (R2*) and prognostic factors. Materials and Methods A total of 159 women with invasive ductal carcinomas (IDCs) underwent breast magnetic resonance imaging (MRI) including blood oxygenation level-dependent (BOLD) sequence at 3 T. The distribution of the measured R2* values were analyzed, and the correlation between R2* and various prognostic factors (age, tumor size, histologic grade, lymphovascular invasion, and axillary lymph node status, as well as expression of estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, p53, and Ki-67) were retrospectively assessed using patient medical records. Results The baseline R2* values of the IDCs were very heterogeneous with wide range among the patients. The mean R2* value was (32.8 ± 14.0) Hz with a median of 29.3 Hz (range 13.5–109.4 Hz). In multivariate analysis, older age was associated with decreased R2* value (P = 0.011) and IDCs with p53-overexpression showed higher R2* values than those without p53-overexpression group (P = 0.031). Other prognostic factors were not significantly correlated with R2* value. Conclusion In this study, R2* values were significantly correlated with age and expression of p53. Further studies are necessary to determine the prognostic value of BOLD-MRI. PMID:27384310

  3. Injector doping level-dependent continuous-wave operation of InP-based QCLs at λ ∼ 7.3 µm above room temperature

    We report the continuous-wave (CW) operation of InGaAs/InAlAs quantum cascade lasers (QCLs) operating at λ ∼ 7.3 µm above room temperature. The injector doping level-dependent CW characteristics above room temperature are investigated for doping densities between 7 × 1016 cm−3 and 2 × 1017 cm−3. The device performance, i.e. threshold current density, output power, operating temperature and characteristic temperature, depends strongly on the injector doping density. For a relatively low injector doping density of 7 × 1016 cm−3, a high-reflectivity-coated 10 µm wide and 4 mm long laser exhibits an improved device performance with an output power of 152 mW and a threshold current density of 1.37 kA cm−2 at 298 K under CW mode, operating up to 343 K. The thermal characteristics are also analyzed by the estimation from the experimentally measured data for the QCLs with different injector doping densities

  4. Blood oxygenation level-dependent magnetic resonance imaging during carbogen breathing: differentiation between prostate cancer and benign prostate hyperplasia and correlation with vessel maturity

    Di, Ningning; Mao, Ning; Cheng, Wenna; Pang, Haopeng; Ren, Yan; Wang, Ning; Liu, Xinjiang; Wang, Bin

    2016-01-01

    Objective The aim of this study was to investigate whether the blood oxygenation level-dependent (BOLD) contrast magnetic resonance imaging (MRI) can evaluate tumor maturity and preoperatively differentiate prostate cancer (PCa) from benign prostate hyperplasia (BPH). Patients and methods BOLD MRI based on transverse relaxation time*-weighted echo planar imaging was performed to assess PCa (19) and BPH (22) responses to carbogen (95% O2 and 5% CO2). The average signal values of PCa and BPH before and after carbogen breathing and the relative increased signal values were computed, respectively. The endothelial-cell marker, CD31, and the pericyte marker, α-smooth muscle actin (mature vessels), were detected with immunofluorescence, and were assessed by microvessel density (MVD) and microvessel pericyte density (MPD). The microvessel pericyte coverage index (MPI) was used to evaluate the degree of vascular maturity. The changed signal from BOLD MRI was correlated with MVD, MPD, and MPI. Results After inhaling carbogen, both PCa and BPH showed an increased signal, but a lower slope was found in PCa than that in BPH (PMPI than BPH. The increased signal intensity was positively correlated with MPI in PCa and that in BPH (r=0.616, P=0.011; r=0.658, P=0.002); however, there was no correlation between the increased signal intensity and MPD or MVD in PCa than that in BPH (P>0.05). Conclusion Our results confirmed that the increased signal values induced by BOLD MRI well differentiated PCa from BPH and had a positive correlation with vessel maturity in both of them. BOLD MRI can be utilized as a surrogate marker for the noninvasive assessment of the degree of vessel maturity. PMID:27462169

  5. Noninvasive Monitoring of Microvascular Changes With Partial Irradiation Using Dynamic Contrast-Enhanced and Blood Oxygen Level-Dependent Magnetic Resonance Imaging

    Lin, Yu-Chun [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Department of Electrical Engineering, Chang Gung University, Linkou, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Wang, Jiun-Jie [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Hong, Ji-Hong [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Lin, Yi-Ping [Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Lee, Chung-Chi [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Wai, Yau-Yau; Ng, Shu-Hang; Wu, Yi-Ming [Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Taiwan (China); Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Wang, Chun-Chieh, E-mail: jjwang@adm.cgmh.org.tw [Department of Medical Imaging and Radiological Sciences, Chang Gung University, Linkou, Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Linkou, Taiwan (China)

    2013-04-01

    Purpose: The microvasculature of a tumor plays an important role in its response to radiation therapy. Dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) and blood oxygen level-dependent (BOLD) MRI are both sensitive to vascular characteristics. The present study proposed a partial irradiation approach to a xenograft tumor to investigate the intratumoral response to radiation therapy using DCE and BOLD MRI. Methods and Materials: TRAMP-C1 tumors were grown in C57BL/6J mice. Partial irradiation was performed on the distal half of the tumor with a single dose of 15 Gy. DCE MRI was performed to derive the endothelium transfer constant, K{sup trans}, using pharmacokinetic analysis. BOLD MRI was performed using quantitative R2* measurements with carbogen breathing. The histology of the tumor was analyzed using hematoxylin and eosin staining and CD31 staining to detect endothelial cells. The differences between the irradiated and nonirradiated regions of the tumor were assessed using K{sup trans} values, ΔR2* values in response to carbogen and microvascular density (MVD) measurements. Results: A significantly increased K{sup trans} and reduced BOLD response to carbogen were found in the irradiated region of the tumor compared with the nonirradiated region (P<.05). Histologic analysis showed a significant aggregation of giant cells and a reduced MVD in the irradiated region of the tumor. The radiation-induced difference in the BOLD response was associated with differences in MVD and K{sup trans}. Conclusions: We demonstrated that DCE MRI and carbogen-challenge BOLD MRI can detect differential responses within a tumor that may potentially serve as noninvasive imaging biomarkers to detect microvascular changes in response to radiation therapy.

  6. Mapping of cerebral metabolic rate of oxygen using dynamic susceptibility contrast and blood oxygen level dependent MR imaging in acute ischemic stroke

    Gersing, Alexandra S.; Schwaiger, Benedikt J. [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); University of California, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Ankenbrank, Monika; Toth, Vivien; Bauer, Jan S.; Zimmer, Claus [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); Janssen, Insa [Technical University Munich, Department of Neurosurgery, Munich (Germany); Kooijman, Hendrik [Philips Healthcare, Hamburg (Germany); Wunderlich, Silke [Technical University Munich, Department of Neurology, Munich (Germany); Preibisch, Christine [Technical University Munich, Klinikum rechts der Isar, Department of Neuroradiology, Munich (Germany); Technical University Munich, Department of Neurology, Munich (Germany)

    2015-12-15

    MR-derived cerebral metabolic rate of oxygen utilization (CMRO{sub 2}) has been suggested to be analogous to PET-derived CMRO{sub 2} and therefore may be used for detection of viable tissue at risk for infarction. The purpose of this study was to evaluate MR-derived CMRO{sub 2} mapping in acute ischemic stroke in relation to established diffusion- and perfusion-weighted imaging. In 23 patients (mean age 63 ± 18.7 years, 11 women) with imaging findings for acute ischemic stroke, relative oxygen extraction fraction was calculated from quantitative transverse relaxation times (T2, T2*) and relative cerebral blood volume using a quantitative blood oxygenation level dependent (BOLD) approach in order to detect a local increase of deoxyhemoglobin. Relative CMRO{sub 2} (rCMRO{sub 2}) maps were calculated by multiplying relative oxygen extraction fraction (rOEF) by cerebral blood flow, derived from PWI. After co-registration, rCMRO{sub 2} maps were evaluated in comparison with apparent diffusion coefficient (ADC) and time-to-peak (TTP) maps. Mean rCMRO{sub 2} values in areas with diffusion-restriction or TTP/ADC mismatch were compared with rCMRO{sub 2} values in the contralateral tissue. In tissue with diffusion restriction, mean rCMRO{sub 2} values were significantly decreased compared to perfusion-impaired (17.9 [95 % confidence interval 10.3, 25.0] vs. 58.1 [95 % confidence interval 50.1, 70.3]; P < 0.001) and tissue in the contralateral hemisphere (68.2 [95 % confidence interval 61.4, 75.0]; P < 0.001). rCMRO{sub 2} in perfusion-impaired tissue showed no significant change compared to tissue in the contralateral hemisphere (58.1 [95 % confidence interval 50.1, 70.3] vs. 66.7 [95 % confidence interval 53.4, 73.4]; P = 0.34). MR-derived CMRO{sub 2} was decreased within diffusion-restricted tissue and stable within perfusion-impaired tissue, suggesting that this technique may be adequate to reveal different pathophysiological stages in acute stroke. (orig.)

  7. Mapping of cerebral metabolic rate of oxygen using dynamic susceptibility contrast and blood oxygen level dependent MR imaging in acute ischemic stroke

    MR-derived cerebral metabolic rate of oxygen utilization (CMRO2) has been suggested to be analogous to PET-derived CMRO2 and therefore may be used for detection of viable tissue at risk for infarction. The purpose of this study was to evaluate MR-derived CMRO2 mapping in acute ischemic stroke in relation to established diffusion- and perfusion-weighted imaging. In 23 patients (mean age 63 ± 18.7 years, 11 women) with imaging findings for acute ischemic stroke, relative oxygen extraction fraction was calculated from quantitative transverse relaxation times (T2, T2*) and relative cerebral blood volume using a quantitative blood oxygenation level dependent (BOLD) approach in order to detect a local increase of deoxyhemoglobin. Relative CMRO2 (rCMRO2) maps were calculated by multiplying relative oxygen extraction fraction (rOEF) by cerebral blood flow, derived from PWI. After co-registration, rCMRO2 maps were evaluated in comparison with apparent diffusion coefficient (ADC) and time-to-peak (TTP) maps. Mean rCMRO2 values in areas with diffusion-restriction or TTP/ADC mismatch were compared with rCMRO2 values in the contralateral tissue. In tissue with diffusion restriction, mean rCMRO2 values were significantly decreased compared to perfusion-impaired (17.9 [95 % confidence interval 10.3, 25.0] vs. 58.1 [95 % confidence interval 50.1, 70.3]; P < 0.001) and tissue in the contralateral hemisphere (68.2 [95 % confidence interval 61.4, 75.0]; P < 0.001). rCMRO2 in perfusion-impaired tissue showed no significant change compared to tissue in the contralateral hemisphere (58.1 [95 % confidence interval 50.1, 70.3] vs. 66.7 [95 % confidence interval 53.4, 73.4]; P = 0.34). MR-derived CMRO2 was decreased within diffusion-restricted tissue and stable within perfusion-impaired tissue, suggesting that this technique may be adequate to reveal different pathophysiological stages in acute stroke. (orig.)

  8. 共济失调患者手运动时脑激活区域的定量分析%Quantitative analysis of the hand motor cortex in ataxia patients using blood oxygen level dependent functional magnetic resonance imaging

    元小冬; 王小洁; 王德; 赵丽君; 王守红

    2010-01-01

    Objective To study the characteristics of the hand motor cortex in ataxia patients during active and passive finger-to-thumb opposition movements using bold oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI). Methods Ten right-handed healthy volunteers and 16 ataxia patients with motor cortex lesions were selected, and whole-brain BOLD-fMRI examinations were made while the subjects were performing the active and passive movements. Activated volume and intensity were recorded from the corresponding motor cortex and analyzed quantitatively. Meanwhile, the patients' coordination was evaluated using the international cooperative ataxia rating scale (ICARS). Results During passive movement of the ataxia patient's affected hands, the ipsilateral supplementary motor area (SMA) activated volume was larger than that during normal ipsilateral hand movement, and the activation intensity was also higher than that in the healthy controls. The ipsilateral cerebellum activated volume and intensity were significantly lower than those in the control group, and the frequency of appearance of the cerebellum was also less. The patients' activated volume and intensity in the ipsilateral cerebellum showed no correlation with ICARS scores. Conclusions When the ataxia patients' affected side cerebellum was dysfunctional, the ipsilateral SMA could compensate for the weak cerebellum function. The ICARS does not reflect cerebellum function.%目的 利用血氧水平依赖性功能性磁共振成像(BOLD-fMRI)技术,探讨共济失调患者在主动与被动复杂对指运动模式下关键脑功能区激活体积和强度的变化.方法 选取共济失调患者16例作为病例组,另选10名健康志愿者作为正常组.入选者均进行主动与被动复杂对指运动,在这两种运动模式下进行BOLD-fMRl检查,记录相应脑运动功能区的激活体积和强度并进行定量分析.采用共济失调量表(ICARS)对共济失调患者的

  9. Longitudial observation of dynamic changes in cortical function and white matter fibrous structure of patients with visual pathway lesions by blood oxygenation level dependent-functional magnetic resonance imaging combined with diffusion tensor imaging

    2007-01-01

    BACKGROUND: Functional magnetic resonance imaging (fMRI) is initially used for visual cortex location.However, the application of fMRI in investigating the development of visual pathway lesions needs to be further observed.OBJECTIVE: This study is to longitudially observe the dynamic changes in cortical function and white matter fibrous structure of patients with visual pathway lesions by blood oxygenation level dependent-functional magnetic resonance imaging (BOLD-fMRI) combined with diffusion tensor imaging (DTI), and to analyze the characteristics of brain function and structural recombination at convalescent period of lesions.DESIGN: Randomized controlled observation.SETTING: Department of Radiology, the General Hospital of Nanjing Military Area Command of Chinese PLA.PARTICIPANTS: Eight patients with unilateral or bilateral visual disorder caused by visual pathway lesions,who admitted to Department of Radiology, the General Hospital of Nanjing Military Area Command of Chinese PLA from January to September 2006 were involved, and served as experimental subjects. The patients, 6 males and 2 females, were aged 16 - 67 years. They had visual disorder confirmed by clinical examination, i.e. visual pathway lesion, which was further diagnosed by MR or CT. Another 12 subjects generally matching to those patients of experimental group in gender, age and sight, who received health examination in synchronization were involved and served as controls. The subjects had no history of eye diseases. Their binocular visual acuity (or corrected visual acuity) was over 1.0. Both routine examination of ophthalmology and examination of fundus were normal. Informed consents of detected items were obtained from all the subjects.METHODS: Signa Excite HD 1.5T magnetic resonance imaging system with 16 passages (GE Company,USA) and coil with 8 passages were used; brain functional stimulus apparatus (SAV-8800. Meide Company) was used for showing experimental mission. At the early stage

  10. Bi-directional astrocytic regulation of neuronal activity within a network

    Alexey V Semyanov

    2012-11-01

    Full Text Available The concept of a tripartite synapse holds that astrocytes can affect both the pre- and postsynaptic compartments through the Ca2+-dependent release of gliotransmitters. Because astrocytic Ca2+ transients usually last for a few seconds, we assumed that astrocytic regulation of synaptic transmission may also occur on the scale of seconds. Here, we considered the basic physiological functions of tripartite synapses and investigated astrocytic regulation at the level of neural network activity. The firing dynamics of individual neurons in a spontaneous firing network was described by the Hodgkin-Huxley model. The neurons received excitatory synaptic input driven by the Poisson spike train with variable frequency. The mean field concentration of the released neurotransmitter was used to describe the presynaptic dynamics. The amplitudes of the excitatory postsynaptic currents (PSCs obeyed the gamma distribution law. In our model, astrocytes depressed the presynaptic release and enhanced the postsynaptic currents. As a result, low frequency synaptic input was suppressed while high frequency input was amplified. The analysis of the neuron spiking frequency as an indicator of network activity revealed that tripartite synaptic transmission dramatically changed the local network operation compared to bipartite synapses. Specifically, the astrocytes supported homeostatic regulation of the network activity by increasing or decreasing firing of the neurons. Thus, the astrocyte activation may modulate a transition of neural network into bistable regime of activity with two stable firing levels and spontaneous transitions between them.

  11. Activities.

    Moody, Mally

    1992-01-01

    A series of four activities are presented to enhance students' abilities to appreciate and use trigonometry as a tool in problem solving. Activities cover problems applying the law of sines, the law of cosines, and matching equivalent trigonometric expressions. A teacher's guide, worksheets, and answers are provided. (MDH)

  12. Application of blood oxygen level-dependent magnetic resonance imaging in chronic kidney disease%血氧水平依赖磁共振成像在慢性肾病中的应用

    王文娟; 郭燕; 李竹浩; 蔡华崧; 史瑶平; 杨栋

    2012-01-01

    背景:血氧水平依赖的磁共振成像是目前惟一能无创性地监测肾血氧含量的方法.目的:探讨血氧水平依赖的磁共振成像在评价慢性肾病患者肾血氧水平、反映肾功能状态方面的价值.方法:对20名健康志愿者和24名慢性肾病患者行肾脏血氧水平依赖的磁共振成像,测量各组肾皮质及髓质的R2*值,并进行统计学分析.结果与结论:正常肾髓质的R2*值高于皮质(P 0.05).慢性肾病患者皮质及髓质的R2*值均高于正常人(P 0.05). Patients with chronic kidney disease had higher cortical and medullary R2*than normal health (P < 0.05). There was a positive correlation between serum creatinine and renal R2* (r=0.564, P =0.004;r=0.588, P =0.003). This research shows that blood oxygen level-dependent magnetic resonance imaging can reflect renal bloodoxygen levels, and has certain value in evaluate the renal function.

  13. Experimental study of renal damage assessment after injection of iodine contrast medium: the role of blood oxygen level-dependent functional MRI with a 3.0 T system

    Objective: To evaluate blood oxygen level-dependent (BOLD) MRI on assessing renal damage after injection of iodine contrast medium with a 3.0 T system. Methods: Routine MRI examination, including T1WI and T2WI, and BOLD MRI were performed in 29 SD rats with a 3.0 T system before the injection of iodine contrast agent and 20 min, 24 h, 48 h, 72 h after the injection, respectively. T2 * and R2 * (=1/T2 *) measurements were obtained in the cortex, inner and outer medulla of kidney, respectively. The results obtained before contrast agent administration were considered as the self-controls. AVONA test were used for the comparison of R2 * values in different parts of both kidneys before contrast agent administration. Two-sample t test was used to compare R2 * values before and at each time point after contrast agent administration, and R2 * values in different parts of the kidneys. Results: Before contrast agent administration, R2 * values in outer medulla in both sides of kidney [R2 * leftOM =(31.76±2.73)/s , R2 * rightOM = (32.77±3.07)/s] were higher than those in cortex [R2 * leftC = (30.20±3.48)/s, R2 * rightC =(28.84±3.11)/s] and in inner medulla [R2 * leftIM =(29.54±2.42)/s, R2 * rightIM = (28.37±2.80)/s] (F=3.357 and 14.961, P2 * values in the three parts between left and right kidney, including cortex, outer and inner medulla (P>0.05). After contrast agent administration, R2 * values in outer medulla changed obviously, which reached to the peak values at 20 minutes after contrast agent administration [R2 * leftOM =(43.57±3.84)/s, R2 * rightOM =(44.58±3.13)/s] and dropped from 24 hours [R2 * leftOM =(42.07±4.82)/s, R2 * rightOM =(42.89±3.40)/s]. R2 * values in inner medulla and cortex only presented slight changes. Conclusion: R2 * values reflected the changes of oxygen content in renal cortex and medulla quantitatively, which helped for detecting medullar ischemia and hypoxia. BOLD MR imaging could offer a feasible method for evaluating oxygen

  14. Clinical application of blood oxygenation level-dependent MR imaging of kidney: A preliminary Study%肾脏血氧水平依赖MRI的初步应用

    徐学勤; 陈楠; 李晓; 林晓珠; 朱晓雷; 倪根雄; 陈克敏; 严福华; 方文强; 徐耀文

    2012-01-01

    目的:探讨肾脏血氧水平依赖(blood oxygenation level-dependent,BOLD) MRI的临床应用价值.方法:对正常志愿者70例(无原发性和继发性肾病病史及肾功能损害危险因素)和57例慢性肾病患者进行GE 1.5THDMRI冠状面BOLD成像,分别测量其肾脏皮质及髓质的自旋弛豫率(R2*)值,并作对比分析.其中10例正常志愿者在1~6个月内进行了相同参数的冠状面BOLD成像检查.结果:T2*图像上,正常肾脏的结构清晰,皮质和髓质分界清,皮质和髓质R2*值分别为(12.63±1.40)/s和(18.14±2.51)/s,双侧肾脏皮质间(t=-1.333,P=0.186)、髓质间(t=0.958,P=0.341)的R2*值差异均无统计学意义.不同年龄及性别的志愿者间肾脏皮质、髓质R2*值亦均无统计学差异(P>0.05).10例志愿者重复BOLD成像肾脏R2*值无统计学差异.T2*图像上,慢性肾病患者的皮髓质分界不清.正常志愿者与慢性肾病患者间肾髓质R2*值差异有统计学意义(P<0.05).结论:肾脏BOLD MRI可清晰显示正常肾脏结构,有较好的可重复性,对慢性肾病患者肾髓质缺氧诊断较灵敏,具有较好的科研及临床应用前景.%Objective To evaluate the clinical application of blood oxygenation level-dependent (BOLD) MR imaging of kidney. Methods: Seventy healthy volunteers and 57 chronic kidney disease (CKD)patients underwent the BOLD MR imaging of the kidney with a 1.5-T MR imager (GE Signa Excite HD Twin-Speed 1.5T) . R2* of cortical and medullar portion of the kidney were calculated and compared. Reproducibility was assessed by repeating the same protocol in 10 randomly selected healthy volunteers after 1-6 months. R2* between patients and heallhy volunteers were compared. Results: In all healthy volunteers,there was a clear demarcation between cortex and medulla on T2* map. Medullary R2* were higher than cortical R2* (18.l4±2.51)/s,(12.63±1.40)/s. There was no difference in renal R2* between right and left kidney (Z.0.05),and no difference in

  15. Architecture Level Dependency Analysis of SOA Based System through ?-Adl

    Pawan Kumar; Ratneshwer

    2016-01-01

    A formal Architecture Description Language (ADL) provides an effective way to dependency analysis at early stage of development. ?-ADL is an ADL that represents the static and dynamic features of software services. In this paper, we describe an approach of dependency analysis of SOA (Service Oriented Architecture) based system, at architecture level, through ?-ADL. A set of algorithms are also proposed for identification of dependency relationships from a SOA based system. The proposed algori...

  16. Effect of Electrical Filtering on Level Dependent ASE Noise

    Witzens, Jeremy

    2016-01-01

    We derive an analytical model describing the effect of filtering on amplified spontaneous emission noise during or after opto-electronic conversion. In particular, we show that electrical filtering results in a further reduction of the signal quality factor associated with an effective increase of the noise levels and can lead to counter-intuitive dependencies of the measured signal quality on the characteristics of the test setup. Closed form equations are compared with numerical models and experiments, showing excellent agreement.

  17. Time varying behavior of the loudspeaker suspension: Displacement level dependency

    Agerkvist, Finn T.; Pedersen, Bo Rohde

    2009-01-01

    how much the suspension has been stretched, i.e. the maximum displacement, is investigated. For this purpose the changes in compliance are measured when exposing the speaker to different levels and types of electrical excitation signals, as well as mechanical excitation only. For sinusoidal excitation......The compliance of the loudspeaker suspension is known to depend on the recent excitation level history. Previous investigations have shown that the electrical power as well as displacement and velocity plays a role. In this paper the hypothesis that the changes in compliance are caused mainly by...... the change in compliance is shown to depend primarily on maximum displacement. But for square pulse excitation the duration of the excitation also plays an important role...

  18. Oral glucose intake inhibits hypothalamic neuronal activity more effectively than glucose infusion

    Smeets, P.A.M.; Vidarsdottir, S.; Graaf, C. de; Stafleu, A.; Osch, M.J.P. van; Viergever, M.A.; Pijl, H.; Grond, J. van der

    2007-01-01

    We previously showed that hypothalamic neuronal activity, as measured by the blood oxygen level-dependent (BOLD) functional MRI signal, declines in response to oral glucose intake. To further explore the mechanism driving changes in hypothalamic neuronal activity in response to an oral glucose load,

  19. Application of Diffusion - weighted Imaging and Blood Oxygen Level - dependent MRI in the Evaluation of Renal Func-tion of Chronic Kidney Disease%磁共振扩散加权成像联合血氧水平依赖成像在慢性肾脏病肾功能评价中的应用

    李成; 房向东; 罗丹丹; 龚良庚; 连珞; 曾磊; 周国盛; 樊烨; 徐高四; 涂卫平

    2014-01-01

    Objective To investigate the application of diffusion - weighted imaging(DWI)and blood oxygen level -dependent MRI(BOLD MRI)in the evaluation of renal function of chronic kidney disease(CKD), Methods A total of 50 pa-tients with CKD who went to Department of Nephrology,the Second Affiliated Hospital of Nanchang University from February to December in 2012,were included in CKD group,20 healthy volunteers were included in control group, The ADC and R2 * values of bilateral cortex and medulla were measured by DWI and BOLD MRI among two groups, According to GFR measured by 99 Tcm -DTPA scintigraphy,CKD group were divided into 3 groups:CKD1 stage group(16 cases);CKD2 stage group(13 cases);CKD3 stage group(21 cases), The changes of ADC and R2 * values among patients with different CKD stages were analyzed, A total of 18 patients received renal biopsy,the correlation between pathological lesion degree and ADC and R2 * values of cortex and medulla was analysed, Results The ADC and R2 * values of bilateral cortex and medulla in CKD1 group,CKD2 group and CKD3 group were significantly lower than those in control group(P 0, 05), The medullary R2 * values were correlated negatively with pathological lesion degree(r = - 0, 659,P 0,05);髓质 R2*值与病理损害积分呈负相关(r =-0,659,P <0,05)。结论肾实质 ADC 值可无创性反映 CKD 肾功能水平及肾脏病理状态的改变。R2*值可以评价 CKD 肾脏髓质的氧代谢的改变,且对于判断 CKD 肾脏病理损伤的程度有一定意义。

  20. Linking human brain local activity fluctuations to structural and functional network architectures

    Baria, A.T.; Mansour, A; Huang, L.; Baliki, M. N.; Cecchi, G. A.; Mesulam, M M; A. V. Apkarian

    2013-01-01

    Activity of cortical local neuronal populations fluctuates continuously, and a large proportion of these fluctuations are shared across populations of neurons. Here we seek organizational rules that link these two phenomena. Using neuronal activity, as identified by functional MRI (fMRI) and for a given voxel or brain region, we derive a single measure of full bandwidth brain-oxygenation-level-dependent (BOLD) fluctuations by calculating the slope, α, for the log-linear power spectrum. For th...

  1. 正常肾脏血氧依赖磁共振成像特点及与生理指标相关性研究%Blood Oxygen Level Dependent MRI of Normal Kidney and Its Correlation with Physiological Indexes

    石会兰; 郑振峰; 马慧; 李峰坦; 张敬; 张云亭

    2014-01-01

    目的:探讨正常肾脏的血氧水平依赖磁共振(BOLD-MRI)成像特点,以及与部分生理指标之间的相关性。方法纳入90例行腹部磁共振检查的非肾脏病患者。使用GE 3.0 T磁共振扫描仪和Torsopa相控阵线圈,行肾脏冠状面T1WI及BOLD成像,BOLD-MRI成像扫描采用T2*自旋梯度回波(T2*SPGR)序列,BOLD影像分析采用R2*map后处理软件,分别从肾脏皮质和髓质区选取感兴趣区(ROI)测量表观自旋-自旋弛豫率(R2*)值。分析R2*值与患者年龄、性别、身高、体质量、体质量指数(BMI)、体表面积(BSA)和估算的肾小球滤过率(eGFR)之间的相关性。结果两侧肾脏皮质区R2*值[左侧(16.56±1.40)Hz和右侧(16.66±1.28)Hz]均低于相应髓质区[左侧(28.82±3.71)Hz和右侧(28.36±3.72)Hz];女性和男性患者皮质R2*值[女性(16.55±1.30)Hz和男性(16.66±1.38Hz)]也低于相应的髓质区[女性(28.46±3.64)Hz和男性(28.70±3.78)Hz]。双侧肾脏髓质区肾脏下极R2*值[(27.29±3.05)]Hz低于中极[(29.32±3.47)Hz]和上极[(29.16±4.21)Hz];差异均有统计学意义。髓质R2*值与年龄呈正相关,与eGFR呈负相关(r分别为0.284、-0.232,均P<0.05)。结论 R2*值可反映肾脏皮髓质氧分压的水平,判断其缺血缺氧程度。BOLD-MRI提供了一种简单、易行且无创性检测肾脏皮髓质氧代谢的方法。%Objective To explore the characteristics of blood oxygen level dependent (BOLD) magnetic resonance imaging (MRI) in healthy native kidneys. To investigate the relationship between BOLD-MRI and common physiological in-dexes. Methods GE 3.0T MRI scanner and Torsopa phased-array coil were employed to acquire renal coronal T1WI and BOLD image. Ninety patients who were ruled out chronic kidney diseases underwent BOLD-MRI with T2*-spoiled gradient recalled echo (T2*SPGR) sequence. BOLD images were analyzed on R2*map software. Cortical and

  2. Alcohol Attenuates Activation in the Bilateral Anterior Insula during an Emotional Processing Task: A Pilot Study †

    Padula, Claudia B.; Simmons, Alan N.; Matthews, Scott C; Robinson, Shannon K.; Tapert, Susan F.; Schuckit, Marc A.; Paulus, Martin P.

    2011-01-01

    Aims: Alcohol acutely reduces agitation and is widely used in social situations, but the neural substrates of emotion processing during its intoxication are not well understood. We examine whether alcohol's social stress dampening effect may be via reduced activity in the cortical systems that subserve awareness of bodily sensations, and are associated with affective distress. Methods: Blood oxygen level-dependent activation was measured through 24 functional magnetic resonance imaging sessio...

  3. The absolute CBF response to activation is preserved during elevated perfusion: Implications for neurovascular coupling measures

    Whittaker, Joseph R.; Driver, Ian D.; Bright, Molly G.; Murphy, Kevin

    2016-01-01

    Functional magnetic resonance imaging (fMRI) techniques in which the blood oxygenation level dependent (BOLD) and cerebral blood flow (CBF) response to a neural stimulus are measured, can be used to estimate the fractional increase in the cerebral metabolic rate of oxygen consumption (CMRO2) that accompanies evoked neural activity. A measure of neurovascular coupling is obtained from the ratio of fractional CBF and CMRO2 responses, defined as n, with the implicit assumption that relative rath...

  4. Relation of obesity to neural activation in response to food commercials

    Gearhardt, Ashley N; Yokum, Sonja; Stice, Eric; Harris, Jennifer L.; Brownell, Kelly D.

    2013-01-01

    Adolescents view thousands of food commercials annually, but the neural response to food advertising and its association with obesity is largely unknown. This study is the first to examine how neural response to food commercials differs from other stimuli (e.g. non-food commercials and television show) and to explore how this response may differ by weight status. The blood oxygen level-dependent functional magnetic resonance imaging activation was measured in 30 adolescents ranging from lean ...

  5. Functional MRI activity in the thalamus and occipital cortex of anesthetized dogs induced by monocular and binocular stimulation.

    Willis, C K; Quinn, R P; McDonell, W M; Gati, J; Partlow, G; Vilis, T.

    2001-01-01

    The neuroanatomy of the mammalian visual system has received considerable attention through electrophysiological study of cats and non-human primates, and through neuroimaging of humans. Canine neuroanatomy, however, has received much less attention, limiting our understanding of canine vision and visual pathways. As an early step in applying blood oxygenation level dependant (BOLD) functional magnetic resonance imaging (fMRI) for veterinary use, we compared visual activity in the thalamus an...

  6. Stimulus Ratio and Level Dependence of Low- and Mid-Frequency Distortion-Product Otoacoustic Emissions

    Christensen, Anders Tornvig; Ordoñez, Rodrigo Pizarro; Hammershøi, Dorte

    2014-01-01

    from heartbeating, breathing and swallowing contaminates the measurement. Above 4000 Hz, calibration of the equipment involved is challenging, if not impossible, to do reliably. Here, we investigate alternative measurement parameters to see if the DPOAE is limited to frequencies above 500 Hz. Few...

  7. Advances of blood oxygen-level dependent MRI in muscular system

    BOLD-fMRI has been applied to muscular system to observe muscular pathophysiological change after performing a task and show the characteristics of muscle perfusion. This paper mainly introduces the scanning sequence, common tasking methods, such as cuff compression, excise, oxygen and drug, etc. It also introduces clinical study of perfusion reserve of muscular tissue with abnormal blood vessels. (authors)

  8. Decoupling the level dependence of the basilar membrane gain and phase in nonlinear cochlea models.

    Sisto, Renata; Moleti, Arturo; Altoè, Alessandro

    2015-08-01

    In animal experiments, the strong dependence on stimulus level of the basilar membrane gain and tuning is not matched by a corresponding change in the phase slope in the resonant region. Linear models, in which the gain dependence on the stimulus level has to be schematized by explicitly changing the tuning parameters of the resonant model, do not easily match this feature of the experimental data. Nonlinear models predict a phase slope that is relatively decoupled from tuning. In addition, delayed-stiffness and feed-forward models also show a significant intrinsic decoupling between gain and tuning, which helps in matching the experimental data. PMID:26328742

  9. DEPEND: A simulation-based environment for system level dependability analysis

    Goswami, Kumar; Iyer, Ravishankar K.

    1992-01-01

    The design and evaluation of highly reliable computer systems is a complex issue. Designers mostly develop such systems based on prior knowledge and experience and occasionally from analytical evaluations of simplified designs. A simulation-based environment called DEPEND which is especially geared for the design and evaluation of fault-tolerant architectures is presented. DEPEND is unique in that it exploits the properties of object-oriented programming to provide a flexible framework with which a user can rapidly model and evaluate various fault-tolerant systems. The key features of the DEPEND environment are described, and its capabilities are illustrated with a detailed analysis of a real design. In particular, DEPEND is used to simulate the Unix based Tandem Integrity fault-tolerance and evaluate how well it handles near-coincident errors caused by correlated and latent faults. Issues such as memory scrubbing, re-integration policies, and workload dependent repair times which affect how the system handles near-coincident errors are also evaluated. Issues such as the method used by DEPEND to simulate error latency and the time acceleration technique that provides enormous simulation speed up are also discussed. Unlike any other simulation-based dependability studies, the use of these approaches and the accuracy of the simulation model are validated by comparing the results of the simulations, with measurements obtained from fault injection experiments conducted on a production Tandem Integrity machine.

  10. Optimal dynamic pricing and replenishment policy for perishable items with inventory-level-dependent demand

    Lu, Lihao; Zhang, Jianxiong; Tang, Wansheng

    2016-04-01

    An inventory system for perishable items with limited replenishment capacity is introduced in this paper. The demand rate depends on the stock quantity displayed in the store as well as the sales price. With the goal to realise profit maximisation, an optimisation problem is addressed to seek for the optimal joint dynamic pricing and replenishment policy which is obtained by solving the optimisation problem with Pontryagin's maximum principle. A joint mixed policy, in which the sales price is a static decision variable and the replenishment rate remains to be a dynamic decision variable, is presented to compare with the joint dynamic policy. Numerical results demonstrate the advantages of the joint dynamic one, and further show the effects of different system parameters on the optimal joint dynamic policy and the maximal total profit.

  11. Study on Supply Chain Disruption Management under Service Level Dependent Demand

    Boqi Li

    2014-06-01

    Full Text Available This paper studied pricing, service level, and production quantity decision problems in a supply chain with one manufacturer and one retailer under demand and production cost disruptions. The joint impact of demand and production cost disruptions on optimal pricing, service level, and production decisions in centralized and decentralized supply chain was analyzed, respectively. By solving the optimization problem, the optimal decisions of the supply chain were obtained under different demand and production cost disruptions scenarios. It is found that the original production quantity and demand-stimulating service level exhibit some robustness under disruptions in both centralized and decentralized supply chains, while the original optimal pricing does not. In centralized supply chains, it is always beneficial for the central decision-maker to knowing of the accurate information of disruptions. However, sharing disruption information is not always beneficial for both the manufacturer and retailer in decentralized supply chain.

  12. Physical activity

    Physical activity -- which includes an active lifestyle and routine exercise -- plus eating well, is the best way to ... shortness of breath when you are active Build physical activity into your regular routine Simple lifestyle changes can ...

  13. Spatial heterogeneity analysis of brain activation in fMRI

    Lalit Gupta

    2014-01-01

    Full Text Available In many brain diseases it can be qualitatively observed that spatial patterns in blood oxygenation level dependent (BOLD activation maps appear more (diffusively distributed than in healthy controls. However, measures that can quantitatively characterize this spatial distributiveness in individual subjects are lacking. In this study, we propose a number of spatial heterogeneity measures to characterize brain activation maps. The proposed methods focus on different aspects of heterogeneity, including the shape (compactness, complexity in the distribution of activated regions (fractal dimension and co-occurrence matrix, and gappiness between activated regions (lacunarity. To this end, functional MRI derived activation maps of a language and a motor task were obtained in language impaired children with (Rolandic epilepsy and compared to age-matched healthy controls. Group analysis of the activation maps revealed no significant differences between patients and controls for both tasks. However, for the language task the activation maps in patients appeared more heterogeneous than in controls. Lacunarity was the best measure to discriminate activation patterns of patients from controls (sensitivity 74%, specificity 70% and illustrates the increased irregularity of gaps between activated regions in patients. The combination of heterogeneity measures and a support vector machine approach yielded further increase in sensitivity and specificity to 78% and 80%, respectively. This illustrates that activation distributions in impaired brains can be complex and more heterogeneous than in normal brains and cannot be captured fully by a single quantity. In conclusion, heterogeneity analysis has potential to robustly characterize the increased distributiveness of brain activation in individual patients.

  14. Physical activity

    ... this page: //medlineplus.gov/ency/article/001941.htm Physical activity To use the sharing features on this page, please enable JavaScript. Physical activity -- which includes an active lifestyle and routine exercise -- ...

  15. Limbic Activity Modulation Guided by Functional Magnetic Resonance Imaging-Inspired Electroencephalography Improves Implicit Emotion Regulation.

    Keynan, Jackob N; Meir-Hasson, Yehudit; Gilam, Gadi; Cohen, Avihay; Jackont, Gilan; Kinreich, Sivan; Ikar, Limor; Or-Borichev, Ayelet; Etkin, Amit; Gyurak, Anett; Klovatch, Ilana; Intrator, Nathan; Hendler, Talma

    2016-09-15

    The amygdala has a pivotal role in processing traumatic stress; hence, gaining control over its activity could facilitate adaptive mechanism and recovery. To date, amygdala volitional regulation could be obtained only via real-time functional magnetic resonance imaging (fMRI), a highly inaccessible procedure. The current article presents high-impact neurobehavioral implications of a novel imaging approach that enables bedside monitoring of amygdala activity using fMRI-inspired electroencephalography (EEG), hereafter termed amygdala-electrical fingerprint (amyg-EFP). Simultaneous EEG/fMRI indicated that the amyg-EFP reliably predicts amygdala-blood oxygen level-dependent activity. Implementing the amyg-EFP in neurofeedback demonstrated that learned downregulation of the amyg-EFP facilitated volitional downregulation of amygdala-blood oxygen level-dependent activity via real-time fMRI and manifested as reduced amygdala reactivity to visual stimuli. Behavioral evidence further emphasized the therapeutic potential of this approach by showing improved implicit emotion regulation following amyg-EFP neurofeedback. Additional EFP models denoting different brain regions could provide a library of localized activity for low-cost and highly accessible brain-based diagnosis and treatment. PMID:26996601

  16. Recent development in noninvasive brain activity measurement by functional magnetic resonance imaging (fMRI)

    fMRI (functional magnetic resonance imaging) is a non-invasive brain imaging technique with which the distribution of neural activity is estimated by measuring local blood flow changes. Blood-oxygenation-level-dependent (BOLD) method measures changes in the density of deoxidized hemoglobin in blood caused by blood flow changes, while other methods have been developed to measure the blood flow changes directly. Effort has been expended to realize a submillimeter spatial resolution by using higher static magnetic field. fMRI has been carried out with various mental tasks, and many important findings have been made on the localization of higher brain functions. (author)

  17. Cortical and brain stem changes in neural activity during static handgrip and postexercise ischemia in humans

    Sander, Mikael; Macefield, Vaughan G; Henderson, Luke A

    2010-01-01

    , and to differentiate between central command and reflex inputs, we used blood oxygen level-dependent (BOLD) functional MRI (fMRI) of the whole brain (3 T). Subjects performed submaximal static handgrip exercise for 2 min followed by 6 min of PEI; MSNA was recorded on a separate day. During the contraction phase......Static isometric exercise increases muscle sympathetic nerve activity (MSNA) and mean arterial pressure, both of which can be maintained at the conclusion of the exercise by occlusion of the arterial supply [postexercise ischemia (PEI)]. To identify the cortical and subcortical sites involved...

  18. Get Active

    ... feeling the benefits of getting active, such as sleeping better or getting toned. Here are 2 ways to add more activity to your life. Be active for longer each time. If you are walking 3 days a week for 30 minutes, try ...

  19. Estimation of the neuronal activation using fMRI data: An observer-based approach

    Laleg-Kirati, Taous-Meriem

    2013-06-01

    This paper deals with the estimation of the neuronal activation and some unmeasured physiological information using the Blood Oxygenation Level Dependent (BOLD) signal measured using functional Magnetic Resonance Imaging (fMRI). We propose to use an observer-based approach applied to the balloon hemodynamic model. The latter describes the relation between the neural activity and the BOLD signal. The balloon model can be expressed in a nonlinear state-space representation where the states, the parameters and the input (neuronal activation), are unknown. This study focuses only on the estimation of the hidden states and the neuronal activation. The model is first linearized around the equilibrium and an observer is applied to this linearized version. Numerical results performed on synthetic data are presented.

  20. Activation analysis

    The neutron activation analysis, which appears to be in limits for further advance, is the most suitable for providing information on the principal as well as the microcomponents in any sample of solid form. Then, instrumental activation analysis is capable of determination of far many elements in various samples. Principally on the neutron activation analysis, the following are described in literature survey from 1982 to middle 1984: bibliography, review, data collection, etc.; problems in spectral analysis and measurement; activation analysis with neutrons; charged particle and photo-nucleus reactions; chemical separation, isotopic dilution activation analysis; molecular activation analysis; standard materials; life and its relation samples; environmental, food, court trial and archaeological samples; space and earth sciences. (Mori, K.)

  1. Active ratchets

    Angelani, L.; Costanzo, A.; Di Leonardo, R.

    2011-12-01

    We analyze self-propelling organisms, or active particles, in a periodic asymmetric potential. Unlike standard ratchet effect for Brownian particles requiring external forcing, in the case of active particles asymmetric potential alone produces a net drift speed (active ratchet effect). By using theoretical models and numerical simulations we demonstrate the emergence of the rectification process in the presence of an asymmetric piecewise periodic potential. The broken spatial symmetry (external potential) and time symmetry (active particles) are sufficient ingredients to sustain unidirectional transport. Our findings open the way to new mechanisms to move in directional manner motile organisms by using external periodic static fields.

  2. Physical Activity

    Andersen, Lars Bo; Anderssen, Sigmund Alfred; Wisløff, Ulrik;

    2014-01-01

    Andersen LB, Anderssen SA, Wisløff U, Hellénius M-L, Fogelholm M, Ekelund U. (Expert Group) Nordic Nutrition Recommendations 2012. Integrating nutrition and physical activity. Chapter: Physical Activity p. 195-217.Nordic Counsil of Ministers.......Andersen LB, Anderssen SA, Wisløff U, Hellénius M-L, Fogelholm M, Ekelund U. (Expert Group) Nordic Nutrition Recommendations 2012. Integrating nutrition and physical activity. Chapter: Physical Activity p. 195-217.Nordic Counsil of Ministers....

  3. Activity report

    The Department of Physics and Measurement Technology, Biology and Chemistry (IFM) presents every year a progress report containing a brief description of activities in research and education within the department. The report is intended as an information for colleagues and institutions. The present report contains activities for the academic year July 1989 to June 1990

  4. Indoor Activities

    ... so you can do some lifting while you watch TV. Walk around the house when you talk on the phone. Make an extra trip up and down the stairs when you do the laundry. Download the Tip Sheet Indoor Activities (PDF, 739.53 KB) You Might Also Like Sun Safety Have Fun. Be Active with Your Dog! ...

  5. Activated Charcoal

    ... reduce intestinal gas (flatulence), lower cholesterol levels, prevent hangover, and treat bile flow problems (cholestasis) during pregnancy. ... pregnancy, according to some early research reports. Preventing hangover. Activated charcoal is included in some hangover remedies, ...

  6. Active Galaxies

    Kilerci Eser, Ece

    Galaxy formation and evolution is one of the main research themes of modern astronomy. Active galaxies such as Active Galactic Nuclei (AGN) and Ultraluminous Infrared Galaxies (ULIRGs) are important evolutionary stages of galaxies. The ULIRG stage is mostly associated with galaxy mergers and...... interactions. During the interactions of gas-rich galaxies, the gas inflows towards the centers of the galaxies and can trigger both star formation and AGN activity. The ULIRG stage includes rapid star formation activity and fast black hole growth that is enshrouded by dust. Once the AGN emission is...... one is related to the mass estimates of supermassive black holes (SMBHs). Mass estimates of SMBHs are important to understand the formation and evolution of SMBHs and their host galaxies. Black hole masses in Type 1 AGN are measured with the reverberation mapping (RM) technique. Reverberation mapping...

  7. Physiological basis and image processing in functional magnetic resonance imaging: Neuronal and motor activity in brain

    Sharma Rakesh

    2004-05-01

    Full Text Available Abstract Functional magnetic resonance imaging (fMRI is recently developing as imaging modality used for mapping hemodynamics of neuronal and motor event related tissue blood oxygen level dependence (BOLD in terms of brain activation. Image processing is performed by segmentation and registration methods. Segmentation algorithms provide brain surface-based analysis, automated anatomical labeling of cortical fields in magnetic resonance data sets based on oxygen metabolic state. Registration algorithms provide geometric features using two or more imaging modalities to assure clinically useful neuronal and motor information of brain activation. This review article summarizes the physiological basis of fMRI signal, its origin, contrast enhancement, physical factors, anatomical labeling by segmentation, registration approaches with examples of visual and motor activity in brain. Latest developments are reviewed for clinical applications of fMRI along with other different neurophysiological and imaging modalities.

  8. Does functional MRI detect activation in white matter? A review of emerging evidence, issues, and future directions

    JodieReannaGawryluk; RyanD'Arcy; ErinLindsayMazerolle

    2014-01-01

    Functional magnetic resonance imaging (fMRI) is a non-invasive technique that allows for visualization of activated brain regions. Until recently, fMRI studies have focused on gray matter. There are two main reasons white matter fMRI remains controversial: (1) the blood oxygen level dependent (BOLD) fMRI signal depends on cerebral blood flow and volume, which are lower in white matter than gray matter and (2) fMRI signal has been associated with post-synaptic potentials (mainly localized in g...

  9. Heterosynaptic plasticity in pyramidal neurons of the hippocampus

    Haslehurst, P.

    2014-01-01

    Homeostatic synaptic plasticity (HSP) is an adjustment of synaptic strength which compensates for chronically altered activity levels in a neuron’s inputs. It is proposed that HSP allows the neuron to retain its ability to discriminate between different inputs in a changing environment. HSP has been demonstrated at several levels: the network, the individual neuron, and the synapse. Synapse-specific HSP involves a paradox: if intense transmission strengthens a synapse, HSP will act in a compe...

  10. Functional MRI study of cerebral cortical activation during volitional swallowing

    Wakasa, Toru; Aiga, Hideki; Yanagi, Yoshinobu; Kawai, Noriko; Sugimoto, Tomosada; Kuboki, Takuo; Kishi, Kanji [Okayama Univ. (Japan). Graduate School of Medicine and Dentistry

    2002-12-01

    The purpose of this study was to investigate the somatotropic distribution and lateralization of motor and sensory cortical activity during swallowing in healthy adult human subjects using functional MR imaging. Nine healthy right-handed adult volunteers (6 men, 3 women; ages 22-38) were examined. Their cortical activities were evoked by having them swallow, five times, a small bolus of water (3 ml) supplied through a plastic catheter. As a positive control, the subjects performed five repetitions of right-handed grasping tasks. Blood oxygenation level-dependent images were obtained using a 1.5 Tesla MR system (Magnetom Vision, Siemens Germany; repetition time/echo time (TR/TE)=0.96/0.66, flip angle (FA)=90 deg). T1 weighted anatomical images were obtained for the same slices in each subject. Cerebral activity was observed most notably in the primary motor cortex and primary somatosensory cortex, followed by the premotor cortex, anterior cingulate cortex, frontal operculum, and insula. The hand-grasping task activated relatively superior parts of the primary motor and somatosensory cortices. The swallowing task, on the other hand, activated the inferior parts of the pre- and postcentral gyri. The hand-grasping activation of motor and sensory cortices was localized absolutely on the contralateral side, whereas swallowing activated the motor cortex either bilaterally or unilaterally. Swallowing activated the sensory cortex almost always bilaterally. This study suggested that fMRI could be used to identify the specific areas of cortical activation caused by various tasks, and to differentiate the locations of cortical activation between tasks. (author)

  11. Functional MRI study of cerebral cortical activation during volitional swallowing

    The purpose of this study was to investigate the somatotropic distribution and lateralization of motor and sensory cortical activity during swallowing in healthy adult human subjects using functional MR imaging. Nine healthy right-handed adult volunteers (6 men, 3 women; ages 22-38) were examined. Their cortical activities were evoked by having them swallow, five times, a small bolus of water (3 ml) supplied through a plastic catheter. As a positive control, the subjects performed five repetitions of right-handed grasping tasks. Blood oxygenation level-dependent images were obtained using a 1.5 Tesla MR system (Magnetom Vision, Siemens Germany; repetition time/echo time (TR/TE)=0.96/0.66, flip angle (FA)=90 deg). T1 weighted anatomical images were obtained for the same slices in each subject. Cerebral activity was observed most notably in the primary motor cortex and primary somatosensory cortex, followed by the premotor cortex, anterior cingulate cortex, frontal operculum, and insula. The hand-grasping task activated relatively superior parts of the primary motor and somatosensory cortices. The swallowing task, on the other hand, activated the inferior parts of the pre- and postcentral gyri. The hand-grasping activation of motor and sensory cortices was localized absolutely on the contralateral side, whereas swallowing activated the motor cortex either bilaterally or unilaterally. Swallowing activated the sensory cortex almost always bilaterally. This study suggested that fMRI could be used to identify the specific areas of cortical activation caused by various tasks, and to differentiate the locations of cortical activation between tasks. (author)

  12. Active colloids

    Aranson, Igor S.

    2013-01-01

    A colloidal suspension is a heterogeneous fluid containing solid microscopic particles. Colloids play an important role in our everyday life, from food and pharmaceutical industries to medicine and nanotechnology. It is useful to distinguish two major classes of colloidal suspensions: equilibrium and active, i.e., maintained out of thermodynamic equilibrium by external electric or magnetic fields, light, chemical reactions, or hydrodynamic shear flow. While the properties of equilibrium colloidal suspensions are fairly well understood, active colloids pose a formidable challenge, and the research is in its early exploratory stage. One of the most remarkable properties of active colloids is the possibility of dynamic self-assembly, a natural tendency of simple building blocks to organize into complex functional architectures. Examples range from tunable, self-healing colloidal crystals and membranes to self-assembled microswimmers and robots. Active colloidal suspensions may exhibit material properties not present in their equilibrium counterparts, e.g., reduced viscosity and enhanced self-diffusivity, etc. This study surveys the most recent developments in the physics of active colloids, both in synthetic and living systems, with the aim of elucidation of the fundamental physical mechanisms governing self-assembly and collective behavior.

  13. Physics activities

    As we move into the 21st Century, nuclear technology is on the verge of rejuvenation in advanced Member States and of expansion in developing Member States. The principal responsibilities of the IAEA are transferring technologies, co-ordinating scientific research, managing specialized projects and maintaining analytical quality control. The IAEA physics activities provide assistance with nuclear instrumentation, promote more effective utilization of research reactors and accelerators, and facilitate global co-operation in nuclear fusion research. These activities will help Member States improve their standards of living through the benefits of nuclear technology. This booklet presents a brief profile on the physics activities and involvement in these fields of the Physics Section, IAEA

  14. Regulatory activities

    This publication, compiled in 8 chapters, presents the regulatory system developed by the Nuclear Regulatory Authority (NRA) of the Argentine Republic. The following activities and developed topics in this document describe: the evolution of the nuclear regulatory activity in Argentina; the Argentine regulatory system; the nuclear regulatory laws and standards; the inspection and safeguards of nuclear facilities; the emergency systems; the environmental systems; the environmental monitoring; the analysis laboratories on physical and biological dosimetry, prenatal irradiation, internal irradiation, radiation measurements, detection techniques on nuclear testing, medical program on radiation protection; the institutional relations with national and international organization; the training courses and meeting; the technical information

  15. Activated Sludge.

    Saunders, F. Michael

    1978-01-01

    Presents the 1978 literature review of wastewater treatment. This review covers: (1) activated sludge process; (2) process control; (3) oxygen uptake and transfer; (4) phosphorus removal; (5) nitrification; (6) industrial wastewater; and (7) aerobic digestion. A list of 136 references is also presented. (HM)

  16. Active house

    Eriksen, Kurt Emil; Olesen, Gitte Gylling Hammershøj

    2010-01-01

    Formålet med dette abstrakt er at illustrere, at huse kan være konstrueret til at basere sig udelukkende på vedvarende energikilder og samtidig være CO2-neutrale og producere mere energi end de forbruger. Active House Visionen undersøger disse muligheder i otte demonstration huse i fem forskellige...

  17. Platelet serotonin transporter function predicts default-mode network activity.

    Christian Scharinger

    Full Text Available The serotonin transporter (5-HTT is abundantly expressed in humans by the serotonin transporter gene SLC6A4 and removes serotonin (5-HT from extracellular space. A blood-brain relationship between platelet and synaptosomal 5-HT reuptake has been suggested, but it is unknown today, if platelet 5-HT uptake can predict neural activation of human brain networks that are known to be under serotonergic influence.A functional magnetic resonance study was performed in 48 healthy subjects and maximal 5-HT uptake velocity (Vmax was assessed in blood platelets. We used a mixed-effects multilevel analysis technique (MEMA to test for linear relationships between whole-brain, blood-oxygen-level dependent (BOLD activity and platelet Vmax.The present study demonstrates that increases in platelet Vmax significantly predict default-mode network (DMN suppression in healthy subjects independent of genetic variation within SLC6A4. Furthermore, functional connectivity analyses indicate that platelet Vmax is related to global DMN activation and not intrinsic DMN connectivity.This study provides evidence that platelet Vmax predicts global DMN activation changes in healthy subjects. Given previous reports on platelet-synaptosomal Vmax coupling, results further suggest an important role of neuronal 5-HT reuptake in DMN regulation.

  18. Digital Activism

    Skovgaard Jørgensen, Emma; Debiteh Dimma Nielsen, Cecilie

    2015-01-01

    This paper examines the phenomenon of digital activism an how it challenges political systems in transition to democracy. As theoretical framework we will use concepts within sociology and political science as analytical tools to our case studies of China and Egypt, in order to find out which role the different concepts play in each case and how these interrelate with one and other. The project was analyzed from a structuralist interpretive approach, viewing social reality as a practice ...

  19. Activity report

    Yu, S W

    2008-08-11

    This report is aimed to show the author's activities to support the LDRD. The title is 'Investigation of the Double-C Behavior in the Pu-Ga Time-Temperature-Transformation Diagram' The sections are: (1) Sample Holder Test; (2) Calculation of x-ray diffraction patterns; (3) Literature search and preparing publications; (4) Tasks Required for APS Experiments; and (5) Communications.

  20. Hepatoprotective Activity.

    2016-01-01

    The liver performs a vital role in metabolism, secretion, storage, and detoxification of endogenous and exogenous substances. Oxidative stress and free radicals enhance the severity of hepatic damage, which can be overcome by the antioxidant mechanism. Plant extracts can be the best source of such antioxidants and mediate hepatoprotective activity. In this chapter, high-dose paracetamol-induced hepatotoxicity in rat model is discussed with explanations of biochemical and histopathological studies. PMID:26939279

  1. Amygdala activity can be modulated by unexpected chord functions during music listening.

    Koelsch, Stefan; Fritz, Thomas; Schlaug, Gottfried

    2008-12-01

    Numerous earlier studies have investigated the cognitive processing of musical syntax with regular and irregular chord sequences. However, irregular sequences may also be perceived as unexpected, and therefore have a different emotional valence than regular sequences. We provide behavioral data showing that irregular chord functions presented in chord sequence paradigms are perceived as less pleasant than regular sequences. A reanalysis of functional MRI data showed increased blood oxygen level-dependent signal changes bilaterally in the amygdala in response to music-syntactically irregular (compared with regular) chord functions. The combined data indicate that music-syntactically irregular events elicit brain activity related to emotional processes, and that, in addition to intensely pleasurable music or highly unpleasant music, single chord functions can also modulate amygdala activity. PMID:19050462

  2. Halal Activism

    Fischer, Johan

    2016-01-01

    The purpose of this article is to further our understanding of contemporary Muslim consumer activism in Malaysia with a particular focus on halal (in Arabic, literally “permissible” or “lawful”) products and services. Muslim activists and organisations promote halal on a big scale in the interface...... particular historical/national settings and that these issues should be explored in the interfaces between Islam, the state and market. More specifically, this article examines the above issues building on ethnography from fieldwork with three Muslim organisations in Malaysia....

  3. Chocolate active

    There is a table of current radioactivity values for various foods and mushrooms. A special accent is on milk and chocolate. Chocolate sorts with more powdered milk are more active. Finally there is a chapter on radionucleides contained in the Chernobyl fallout, other than cesium 137, cesium 134 and strontium 90. The amounts of ruthenium 106, antimony 125, cerium 144, silver 110 m, cesium 134, strontium 90 and plutonium 239 relative to cesium 137 in soil samples in autumn 1987 are given. Special emphasis is on ruthenium 'hot particles' and on plutonium. (qui)

  4. Activating schoolyards

    Andersen, Henriette Bondo; Pawlowski, Charlotte Skau; Scheller, Hanne Bebendorf;

    2015-01-01

    objectively determine where and how active the students are in the schoolyard, before and after the intervention. This provides a type of data that, to our knowledge, has not been used before in schoolyard interventions. Exploring the change in behavior in relation to specific intervention elements in the...... accelerometer, GPS and GIS; 3) a process evaluation facilitating the intervention development process and identifying barriers and facilitators in the implementation process; 4) a post-intervention end-user evaluation aimed at exploring who uses the schoolyards and how the schoolyards are used. The seven...

  5. Active packaging with antifungal activities.

    Nguyen Van Long, N; Joly, Catherine; Dantigny, Philippe

    2016-03-01

    There have been many reviews concerned with antimicrobial food packaging, and with the use of antifungal compounds, but none provided an exhaustive picture of the applications of active packaging to control fungal spoilage. Very recently, many studies have been done in these fields, therefore it is timely to review this topic. This article examines the effects of essential oils, preservatives, natural products, chemical fungicides, nanoparticles coated to different films, and chitosan in vitro on the growth of moulds, but also in vivo on the mould free shelf-life of bread, cheese, and fresh fruits and vegetables. A short section is also dedicated to yeasts. All the applications are described from a microbiological point of view, and these were sorted depending on the name of the species. Methods and results obtained are discussed. Essential oils and preservatives were ranked by increased efficacy on mould growth. For all the tested molecules, Penicillium species were shown more sensitive than Aspergillus species. However, comparison between the results was difficult because it appeared that the efficiency of active packaging depended greatly on the environmental factors of food such as water activity, pH, temperature, NaCl concentration, the nature, the size, and the mode of application of the films, in addition to the fact that the amount of released antifungal compounds was not constant with time. PMID:26803804

  6. A deterministic model for deteriorating items with displayed inventory level dependent demand rate incorporating marketing decisions with transportation cost

    A. K. Bhunia

    2011-01-01

    Full Text Available This paper deals with an inventory model, which considers the impact of marketing strategies such as pricing and advertising as well as the displayed inventory level on the demand rate of the system. In addition, the demand rate during the stock-out period differs from that during the stock-in period by a function varied on the waiting time up to the beginning of the next cycle. Shortage are allowed and partially backlogged. Here, the deterioration rate is assumed to follow the Weibull distribution. Considering all these factors with others, different scenarios of the system are investigated. To obtain the solutions of these cases and to illustrate the model, an example is considered. Finally, to study the effects of changes of different parameters of the system, sensitivity analyses have been carried out with respect to the different parameters of the system.

  7. Visual perception from the perspective of a representational, non-reductionistic, level-dependent account of perception and conscious awareness

    Overgaard, Morten; Mogensen, Jesper

    2014-01-01

    analysis in a ‘situational algorithmic strategy’ that reflects the general state of an individual. We argue that conscious experience is intrinsically related to representations that are available to guide behaviour. From this perspective, we find that blindsight and subliminal perception can be explained...

  8. On the Accuracy of Fluid Approximations to a Class of Inventory-Level-Dependent EOQ and EPQ Models

    Alexey Piunovskiy

    2011-01-01

    Full Text Available Deterministic Economic Order Quantity (EOQ models have been studied intensively in the literature, where the demand process is described by an ordinary differential equation, and the objective is to obtain an EOQ, which minimizes the total cost per unit time. The total cost per unit time consists of a “discrete” part, the setup cost, which is incurred at the time of ordering, and a “continuous” part, the holding cost, which is continuously accumulated over time. Quite formally, such deterministic EOQ models can be viewed as fluid approximations to the corresponding stochastic EOQ models, where the demand process is taken as a stochastic jump process. Suppose now an EOQ is obtained from a deterministic model. The question is how well does this quantity work in the corresponding stochastic model. In the present paper we justify a translation of EOQs obtained from deterministic models, under which the resulting order quantities are asymptotically optimal for the stochastic models, by showing that the difference between the performance measures and the optimal values converges to zero with respect to a scaling parameter. Moreover, we provide an estimate for the rate of convergence. The same issue regarding specific Economic Production Quantity (EPQ models is studied, too.

  9. A multi-item inventory system with expected shortage level-dependent backorder rate with working capital and space restrictions

    Mirzazadeh, A; A. Gholami-Qadikolaei; M. Kajizad

    2012-01-01

    |In this paper, a new multi-item inventory system is considered with random demand and random lead time including m working capital and space constraints with three decision variables: order quantity, safety factor and backorder rate. The demand rate during lead time is stochastic with unknown distribution function and known mean and variance. Random constraints are transformed to crisp constraints with using the chance-constrained method. The Minimax distribution free procedure has been used...

  10. A multi-item inventory system with expected shortage level-dependent backorder rate with working capital and space restrictions

    A. Mirzazadeh

    2012-01-01

    Full Text Available |In this paper, a new multi-item inventory system is considered with random demand and random lead time including m working capital and space constraints with three decision variables: order quantity, safety factor and backorder rate. The demand rate during lead time is stochastic with unknown distribution function and known mean and variance. Random constraints are transformed to crisp constraints with using the chance-constrained method. The Minimax distribution free procedure has been used to lead proposed model to the optimal solution. The shortage is allowed and the backlogging rate is dependent on the expected shortage quantity at the end of cycle. Two numerical examples are presented to illustrate the proposed solution method.

  11. The equilibrium equations for the lost sales (r,q) policy with inventory level dependent demand and multiple outstanding orders

    Johnston, Bryan

    2012-01-01

    We develop the equilibrium equations for the a model generalizing the continuous review (r, q) lost-sales model with constant lead time, multiple outstanding orders and unit Poisson demand. Demand rate is allowed to depend on inventory level. The model is solved for the case r=2,q=2 as well as the general case q=1. An application is given for a system involving lateral transshipments.

  12. Individual Variability in Brain Activity: A Nuisance or an Opportunity?

    Van Horn, John Darrell; Grafton, Scott T; Miller, Michael B

    2008-12-01

    Functional imaging research has been heavily influenced by results based on population-level inference. However, group average results may belie the unique patterns of activity present in the individual that ordinarily are considered random noise. Recent advances in the evolution of MRI hardware have led to significant improvements in the stability and reproducibility of blood oxygen level dependent (BOLD) measurements. These enhancements provide a unique opportunity for closer examination of individual patterns of brain activity. Three objectives can be accomplished by considering brain scans at the individual level; (1) Mapping functional anatomy at a fine grained analysis; (2) Determining if an individual scan is normative with respect to a reference population; and (3) Understanding the sources of intersubject variability in brain activity. In this review, we detail these objectives, briefly discuss their histories and present recent trends in the analyses of individual variability. Finally, we emphasize the unique opportunities and challenges for understanding individual differences through international collaboration among Pacific Rim investigators. PMID:19777073

  13. Comparison of brain activation to purposefully activate a tool in healthy subjects and brain tumor patients using fMRI

    The purpose of this study was to determine the functional organization of the human brain involved in tool-manipulation. Blood Oxygen Level Dependent was measured by functional magnetic resonance imaging in seventeen right-handed healthy volunteers and two brain tumor patients during two tool-manipulation tasks: simulated tightening a bolt with a screwdriver (Simulation), and tightening a bolt with a screwdriver (Real). Subjects performed the experiment without watching the tasks. Bilateral pre-supplementary motor areas, bilateral cerebellar posterior lobes, right ventral premotor area, right calcarine sulcus, and cerebellar vermis were activated during Real but not during Simulation tasks in healthy volunteers. In addition, brain tumor patients activated the prefrontal areas. Our results suggest that the human brain mechanisms for tool-manipulation have a neural-network comprised of presupplementary motor area, ventral premotor area, and bilateral cerebellar posterior lobes. In the patients with brain dusfurction diee to tumors, activation at the prefrontal area provided function compensation without motor paralysis. (author)

  14. Active sharing

    2012-01-01

    The big news this week is, of course, the conclusions from the LHC performance workshop held in Chamonix from 6 to 10 February . The main recommendation, endorsed by CERN’s Machine Advisory Committee and adopted by the Management, is that the LHC will run at 4 TeV per beam this year. You can find all the details from Chamonix in the slides presented on Wednesday at the summary session, which leaves me free to talk about another important development coming up soon.   In ten days time, a new kind of gathering will be taking place in Geneva, bringing together two previously separate conferences, one driven by physics, the other by the medical community, but both looking to apply physics to the advancement of health. The merger of the International Conference for Translational Research in Radio-Oncology and CERN’s workshop on Physics for Health in Europe (ICTR-PHE) makes for a very eclectic mix. Presentations range from active shielding for interplanetary flight to the rather...

  15. IASS Activity

    Hojaev, Alisher S.; Ibragimova, Elvira M.

    2015-08-01

    It’s well known, astronomy in Uzbekistan has ancient roots and traditions (e.g., Mirzo Ulugh Beg, Abū al-Rayhān al-Bīrūnī, Abū ‘Abdallāh al-Khwārizmī) and astronomical heritage carefully preserved. Nowadays uzbek astronomers play a key role in scientific research but also in OAD and Decadal Plan activity in the Central Asia region. International Aerospace School (IASS) is an amazing and wonderful event held annually about 30 years. IASS is unique project in the region, and at the beginning we spent the Summer and Winter Schools. At present in the summer camp we gather about 50 teenage and undergraduate students over the country and abroad (France, Malaysia, Turkey, Azerbaijan, Pakistan, Russia, etc.). They are selected on the basis of tests of astronomy and space issues. During two weeks of IASS camp the invited scientists, cosmonauts and astronauts as well as other specialists give lectures and engage in practical exercises with IASS students in astronomy, including daily observations of the Sun and night sky observations with meniscus telescope, space research and exploration, aerospace modelling, preparation and presentation of original projects. This is important that IASS gives not theoretical grounds only but also practically train the students and the hands-on training is the major aims of IASS. Lectures and practice in the field of astronomy carried out with the direct involvement and generous assistance of Uranoscope Association (Paris, France). The current 26-th IASS is planned to held in July 2015.

  16. Physical Activity (Exercise)

    ... Our ePublications > Physical activity (exercise) fact sheet ePublications Physical activity (exercise) fact sheet How can physical activity improve ... Have had recent hip surgery More information on physical activity (exercise) For more information about physical activity (exercise), ...

  17. Metabolic activity of permafrost bacteria below the freezing point

    Rivkina, E. M.; Friedmann, E. I.; McKay, C. P.; Gilichinsky, D. A.

    2000-01-01

    Metabolic activity was measured in the laboratory at temperatures between 5 and -20 degrees C on the basis of incorporation of (14)C-labeled acetate into lipids by samples of a natural population of bacteria from Siberian permafrost (permanently frozen soil). Incorporation followed a sigmoidal pattern similar to growth curves. At all temperatures, the log phase was followed, within 200 to 350 days, by a stationary phase, which was monitored until the 550th day of activity. The minimum doubling times ranged from 1 day (5 degrees C) to 20 days (-10 degrees C) to ca. 160 days (-20 degrees C). The curves reached the stationary phase at different levels, depending on the incubation temperature. We suggest that the stationary phase, which is generally considered to be reached when the availability of nutrients becomes limiting, was brought on under our conditions by the formation of diffusion barriers in the thin layers of unfrozen water known to be present in permafrost soils, the thickness of which depends on temperature.

  18. Activation Energy

    Gadeken, Owen

    2002-01-01

    Teaming is so common in today's project management environment that most of us assume it comes naturally. We further assume that when presented with meaningful and challenging work, project teams will naturally engage in productive activity to complete their tasks. This assumption is expressed in the simple (but false) equation: Team + Work = Teamwork. Although this equation appears simple and straightforward, it is far from true for most project organizations whose reality is a complex web of institutional norms based on individual achievement and rewards. This is illustrated by the very first successful team experience from my early Air Force career. As a young lieutenant, I was sent to Squadron Officer School, which was the first in the series of Air Force professional military education courses I was required to complete during my career. We were immediately formed into teams of twelve officers. Much of the course featured competition between these teams. As the most junior member of my team, I quickly observed the tremendous pressure to show individual leadership capability. At one point early in the course, almost everyone in our group was vying to become the team leader. This conflict was so intense that it caused us to fail miserably in our first outdoor team building exercise. We spent so much time fighting over leadership that we were unable to complete any of the events on the outdoor obstacle course. This complete lack of success was so disheartening to me that I gave our team little hope for future success. What followed was a very intense period of bickering, conflict, and even shouting matches as our dysfunctional team tried to cope with our early failures and find some way to succeed. British physician and researcher Wilfred Bion (Experiences in Groups, 1961) discovered that there are powerful psychological forces inherent in all groups that divert from accomplishing their primary tasks. To overcome these restraining forces and use the potential

  19. Parametric modulation of neural activity by emotion in youth with bipolar disorder, youth with severe mood dysregulation, and healthy volunteers.

    Thomas, Laura A; Brotman, Melissa A; Muhrer, Eli J; Rosen, Brooke H; Bones, Brian L; Reynolds, Richard C; Deveney, Christen M; Pine, Daniel S; Leibenluft, Ellen

    2012-12-01

    CONTEXT Youth with bipolar disorder (BD) and those with severe, nonepisodic irritability (severe mood dysregulation [SMD]) exhibit amygdala dysfunction during facial emotion processing. However, studies have not compared such patients with each other and with comparison individuals in neural responsiveness to subtle changes in facial emotion; the ability to process such changes is important for social cognition. To evaluate this, we used a novel, parametrically designed faces paradigm. OBJECTIVE To compare activation in the amygdala and across the brain in BD patients, SMD patients, and healthy volunteers (HVs). DESIGN Case-control study. SETTING Government research institute. PARTICIPANTS Fifty-seven youths (19 BD, 15 SMD, and 23 HVs). MAIN OUTCOME MEASURE Blood oxygenation level-dependent data. Neutral faces were morphed with angry and happy faces in 25% intervals; static facial stimuli appeared for 3000 milliseconds. Participants performed hostility or nonemotional facial feature (ie, nose width) ratings. The slope of blood oxygenation level-dependent activity was calculated across neutral-to-angry and neutral-to-happy facial stimuli. RESULTS In HVs, but not BD or SMD participants, there was a positive association between left amygdala activity and anger on the face. In the neutral-to-happy whole-brain analysis, BD and SMD participants modulated parietal, temporal, and medial-frontal areas differently from each other and from that in HVs; with increasing facial happiness, SMD patients demonstrated increased, and BD patients decreased, activity in the parietal, temporal, and frontal regions. CONCLUSIONS Youth with BD or SMD differ from HVs in modulation of amygdala activity in response to small changes in facial anger displays. In contrast, individuals with BD or SMD show distinct perturbations in regions mediating attention and face processing in association with changes in the emotional intensity of facial happiness displays. These findings demonstrate

  20. Increased BOLD activation to predator stressor in subiculum and midbrain of amphetamine-sensitized maternal rats.

    Febo, Marcelo; Pira, Ashley S

    2011-03-25

    Amphetamine, which is known to cause sensitization, potentiates the hormonal and neurobiological signatures of stress and may also increase sensitivity to stress-inducing stimuli in limbic areas. Trimethylthiazoline (5μL TMT) is a chemical constituent of fox feces that evokes innate fear and activates the neuronal and hormonal signatures of stress in rats. We used blood oxygen level dependent (BOLD) MRI to test whether amphetamine sensitization (1mg/kg, i.p. ×3days) in female rats has a lasting effect on the neural response to a stress-evoking stimulus, the scent of a predator, during the postpartum period. The subiculum and dopamine-enriched midbrain VTA/SN of amphetamine-sensitized but not control mothers showed a greater BOLD signal response to predator odor than a control putrid scent. The greater responsiveness of these two brain regions following stimulant sensitization might impact neural processing in response to stressors in the maternal brain. PMID:21134359

  1. Tension-related activity in the orbitofrontal cortex and amygdala: an fMRI study with music.

    Lehne, Moritz; Rohrmeier, Martin; Koelsch, Stefan

    2014-10-01

    Tonal music is characterized by a continuous flow of tension and resolution. This flow of tension and resolution is closely related to processes of expectancy and prediction and is a key mediator of music-evoked emotions. However, the neural correlates of subjectively experienced tension and resolution have not yet been investigated. We acquired continuous ratings of musical tension for four piano pieces. In a subsequent functional magnetic resonance imaging experiment, we identified blood oxygen level-dependent signal increases related to musical tension in the left lateral orbitofrontal cortex (pars orbitalis of the inferior frontal gyrus). In addition, a region of interest analysis in bilateral amygdala showed activation in the right superficial amygdala during periods of increasing tension (compared with decreasing tension). This is the first neuroimaging study investigating the time-varying changes of the emotional experience of musical tension, revealing brain activity in key areas of affective processing. PMID:23974947

  2. ACTIVITY MINING: FROM ACTIVITIES TO ACTIONS

    LONGBING CAO; YANCHANG ZHAO; CHENGQI ZHANG; HUAIFENG ZHANG

    2008-01-01

    Activity data accumulated in real life, such as terrorist activities and governmental customer contacts, present special structural and semantic complexities. Activity data may lead to or be associated with significant business impacts, and result in important actions and decision making leading to business advantage. For instance, a series of terrorist activities may trigger a disaster to society, and large amounts of fraudulent activities in social security programs may result in huge gover...

  3. Activation of superior colliculi in humans during visual exploration

    Karnath Hans-Otto

    2007-08-01

    Full Text Available Abstract Background Visual, oculomotor, and – recently – cognitive functions of the superior colliculi (SC have been documented in detail in non-human primates in the past. Evidence for corresponding functions of the SC in humans is still rare. We examined activity changes in the human tectum and the lateral geniculate nuclei (LGN in a visual search task using functional magnetic resonance imaging (fMRI and anatomically defined regions of interest (ROI. Healthy subjects conducted a free visual search task and two voluntary eye movement tasks with and without irrelevant visual distracters. Blood oxygen level dependent (BOLD signals in the SC were compared to activity in the inferior colliculi (IC and LGN. Results Neural activity increased during free exploration only in the SC in comparison to both control tasks. Saccade frequency did not exert a significant effect on BOLD signal changes. No corresponding differences between experimental tasks were found in the IC or the LGN. However, while the IC revealed no signal increase from the baseline, BOLD signal changes at the LGN were consistently positive in all experimental conditions. Conclusion Our data demonstrate the involvement of the SC in a visual search task. In contrast to the results of previous studies, signal changes could not be seen to be driven by either visual stimulation or oculomotor control on their own. Further, we can exclude the influence of any nearby neural structures (e.g. pulvinar, tegmentum or of typical artefacts at the brainstem on the observed signal changes at the SC. Corresponding to findings in non-human primates, our data support a dependency of SC activity on functions beyond oculomotor control and visual processing.

  4. Brain oscillatory activity during motor imagery in EEG-fMRI coregistration.

    Formaggio, Emanuela; Storti, Silvia Francesca; Cerini, Roberto; Fiaschi, Antonio; Manganotti, Paolo

    2010-12-01

    The purpose of the present work was to investigate the correlation between topographical changes in brain oscillatory activity and the blood oxygenation level-dependent (BOLD) signal during a motor imagery (MI) task using electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) coregistration. EEG was recorded in 7 healthy subjects inside a 1.5 T MR scanner during the imagination of the kinesthetic experience of movement. A Fast Fourier Transform was applied to EEG signal in the rest and active conditions. We used the event-related-synchronization (ERS)/desynchronization (ERD) approach to characterize where the imagination of movement produces a decrease in alpha and beta power. The mean alpha map showed ERD decrease localized over the contralateral sensory motor area (SM1c) and a light desynchronization in the ipsilateral sensory motor area (SM1i); whereas the mean beta map showed ERD decrease over the supplementary motor area (SMA). fMRI showed significant activation in SMA, SM1c, SM1i. The correlation is negative in the contralateral side and positive in the ipsilateral side. Using combined EEG-fMRI signals we obtained useful new information on the description of the changes in oscillatory activity in alpha and beta bands during MI and on the investigation of the sites of BOLD activity as possible sources in generating these rhythms. By correlating BOLD and ERD/ERS we may identify more accurately which regions contribute to changes of the electrical response. PMID:20850237

  5. Effects of anesthesia on BOLD signal and neuronal activity in the somatosensory cortex.

    Aksenov, Daniil P; Li, Limin; Miller, Michael J; Iordanescu, Gheorghe; Wyrwicz, Alice M

    2015-11-01

    Most functional magnetic resonance imaging (fMRI) animal studies rely on anesthesia, which can induce a variety of drug-dependent physiological changes, including depression of neuronal activity and cerebral metabolism as well as direct effects on the vasculature. The goal of this study was to characterize the effects of anesthesia on the BOLD signal and neuronal activity. Simultaneous fMRI and electrophysiology were used to measure changes in single units (SU), multi-unit activity (MUA), local field potentials (LFP), and the blood oxygenation level-dependent (BOLD) response in the somatosensory cortex during whisker stimulation of rabbits before, during and after anesthesia with fentanyl or isoflurane. Our results indicate that anesthesia modulates the BOLD signal as well as both baseline and stimulus-evoked neuronal activity, and, most significantly, that the relationship between the BOLD and electrophysiological signals depends on the type of anesthetic. Specifically, the behavior of LFP observed under isoflurane did not parallel the behavior of BOLD, SU, or MUA. These findings suggest that the relationship between these signals may not be straightforward. BOLD may scale more closely with the best measure of the excitatory subcomponents of the underlying neuronal activity, which may vary according to experimental conditions that alter the excitatory/inhibitory balance in the cortex. PMID:26104288

  6. Carbamazepine reduces memory induced activation of mesial temporal lobe structures: a pharmacological fMRI-study

    Okujava Michael

    2001-11-01

    Full Text Available Abstract Background and Purpose It is not known whether carbamazepine (CBZ; a drug widely used in neurology and psychiatry influences the blood oxygenation level dependent (BOLD contrast changes induced by neuronal activation and measured by functional MRI (fMRI. We aimed to investigate the influence of CBZ on memory induced activation of the mesial temporal lobes in patients with symptomatic temporal lobe epilepsy (TLE. Material and Methods Twenty-one individual patients with refractory symptomatic TLE with different CBZ serum levels and 20 healthy controls were studied using BOLD fMRI. Mesial temporal lobe (MTL activation was induced by a task that is based on the retrieval of individually familiar visuo-spatial knowledge. The extent of significant MTL fMRI activation was measured and correlated with the CBZ serum level. Results In TLE patients, the extent of significant fMRI activation over both MTL was negatively correlated to the CBZ serum level (Spearman r = -0.654, P Conclusions In TLE patients, carbamazepine reduces the fMRI-detectable changes within the mesial temporal lobes as induced by effortful memory retrieval. FMRI appears to be suitable to study the effects of chronic drug treatment in patients with epilepsy.

  7. Cortical connective field estimates from resting state fMRI activity

    Gravel, Nicolás; Harvey, Ben; Nordhjem, Barbara; Haak, Koen V.; Dumoulin, Serge O.; Renken, Remco; Ćurčić-Blake, Branislava; Cornelissen, Frans W.

    2014-01-01

    One way to study connectivity in visual cortical areas is by examining spontaneous neural activity. In the absence of visual input, such activity remains shaped by the underlying neural architecture and, presumably, may still reflect visuotopic organization. Here, we applied population connective field (CF) modeling to estimate the spatial profile of functional connectivity in the early visual cortex during resting state functional magnetic resonance imaging (RS-fMRI). This model-based analysis estimates the spatial integration between blood-oxygen level dependent (BOLD) signals in distinct cortical visual field maps using fMRI. Just as population receptive field (pRF) mapping predicts the collective neural activity in a voxel as a function of response selectivity to stimulus position in visual space, CF modeling predicts the activity of voxels in one visual area as a function of the aggregate activity in voxels in another visual area. In combination with pRF mapping, CF locations on the cortical surface can be interpreted in visual space, thus enabling reconstruction of visuotopic maps from resting state data. We demonstrate that V1 ➤ V2 and V1 ➤ V3 CF maps estimated from resting state fMRI data show visuotopic organization. Therefore, we conclude that—despite some variability in CF estimates between RS scans—neural properties such as CF maps and CF size can be derived from resting state data. PMID:25400541

  8. Brain activation studies with PET and functional MRI

    Application of PET and functional MRI in brain activation studies is reviewed. 3D-PET images obtained repeatedly after intravenous injection of about 370 MBq of H215O can detect a faint blood flow change in the brain. Functional MRI can also detect the blood flow change in the brain due to blood oxygen level-dependent effect. Echo-planar imaging is popular in MRI with 1.5 or 3 T. Images are analyzed by statistical parametric mapping with correction of cerebral regions, anatomical normalization and statistics. PET data give the blood flow change by the H215O incorporation into the brain and MRI data, by the scarce tissue oxygen consumption despite the change. Actual images during the cognition task-performance and of frequent artifacts are given. PET is suitable for studies of brain functions like sensibility and emotion and functional MRI, like cortex functions and clinical practices in identification of functional regions prior to surgery and evaluation of functional recovery of damaged brain. (K.H.)

  9. Dynamic characteristics of oxygenation-sensitive MRI signal in different temporal protocols for imaging human brain activity

    The temporal characteristics of cerebral blood oxygenation during human brain activation were monitored with dynamic echo-planar imaging (EPI) using the blood oxygenation level dependent (BOLD) fMRI. We investigated oxygenation-sensitive signal changes: 1. during repetitive block stimuli, to determine the latency of the activation-induced signal change in the primary visual cortex; 2. on shortening the rest periods between constant stimulated phases, to investigate the limitations that this latency poses in temporal resolution of the technique; and 3. on sustained steady-state stimulation, to characterise oxygenation changes during prolonged brain activation using different stimuli. Delayed intrinsic haemodynamic response and a finite signal-to-noise ratio limit the temporal resolution achieved with BOLD fMRI. Separate activation periods were resolved when the delay between consecutive stimulations was at least 2 s. In this study oxygenation remained elevated throughout sustained activation, suggesting a constant rate of oxygen consumption by the primary cortical neurones during activation. Characterisation of fMRI signal dynamics in dynamic temporal protocols is significant both in terms of optimising stimulation protocols and the potential to gain insight into the physiological mechanisms underlying neuronal activation which could increase the clinical applicability of the technique. (orig.)

  10. Relation of obesity to neural activation in response to food commercials.

    Gearhardt, Ashley N; Yokum, Sonja; Stice, Eric; Harris, Jennifer L; Brownell, Kelly D

    2014-07-01

    Adolescents view thousands of food commercials annually, but the neural response to food advertising and its association with obesity is largely unknown. This study is the first to examine how neural response to food commercials differs from other stimuli (e.g. non-food commercials and television show) and to explore how this response may differ by weight status. The blood oxygen level-dependent functional magnetic resonance imaging activation was measured in 30 adolescents ranging from lean to obese in response to food and non-food commercials imbedded in a television show. Adolescents exhibited greater activation in regions implicated in visual processing (e.g. occipital gyrus), attention (e.g. parietal lobes), cognition (e.g. temporal gyrus and posterior cerebellar lobe), movement (e.g. anterior cerebellar cortex), somatosensory response (e.g. postcentral gyrus) and reward [e.g. orbitofrontal cortex and anterior cingulate cortex (ACC)] during food commercials. Obese participants exhibited less activation during food relative to non-food commercials in neural regions implicated in visual processing (e.g. cuneus), attention (e.g. posterior cerebellar lobe), reward (e.g. ventromedial prefrontal cortex and ACC) and salience detection (e.g. precuneus). Obese participants did exhibit greater activation in a region implicated in semantic control (e.g. medial temporal gyrus). These findings may inform current policy debates regarding the impact of food advertising to minors. PMID:23576811

  11. Right hemisphere neural activations in the recall of waking fantasies and of dreams.

    Benedetti, Francesco; Poletti, Sara; Radaelli, Daniele; Ranieri, Rebecca; Genduso, Valeria; Cavallotti, Simone; Castelnovo, Anna; Smeraldi, Enrico; Scarone, Silvio; D'Agostino, Armando

    2015-10-01

    The story-like organization of dreams is characterized by a pervasive bizarreness of events and actions that resembles psychotic thought, and largely exceeds that observed in normal waking fantasies. Little is known about the neural correlates of the confabulatory narrative construction of dreams. In this study, dreams, fantasies elicited by ambiguous pictorial stimuli, and non-imaginative first- and third-person narratives from healthy participants were recorded, and were then studied for brain blood oxygen level-dependent functional magnetic resonance imaging on a 3.0-Tesla scanner while listening to their own narrative reports and attempting a retrieval of the corresponding experience. In respect to non-bizarre reports of daytime activities, the script-driven recall of dreams and fantasies differentially activated a right hemisphere network including areas in the inferior frontal gyrus, and superior and middle temporal gyrus. Neural responses were significantly greater for fantasies than for dreams in all regions, and inversely proportional to the degree of bizarreness observed in narrative reports. The inferior frontal gyrus, superior and middle temporal gyrus have been implicated in the semantic activation, integration and selection needed to build a coherent story representation and to resolve semantic ambiguities; in deductive and inferential reasoning; in self- and other-perspective taking, theory of mind, moral and autobiographical reasoning. Their degree of activation could parallel the level of logical robustness or inconsistency experienced when integrating information and mental representations in the process of building fantasy and dream narratives. PMID:25871325

  12. Guide to Physical Activity

    ... Families ( We Can! ) Health Professional Resources Guide to Physical Activity Physical activity is an important part of your ... to injury. Examples of moderate-intensity amounts of physical activity Common Chores Washing and waxing a car for ...

  13. Charitable activities in Azerbaijan

    Ismailova Sevil Aydin

    2015-01-01

    In this article, found its proper reflection questions related to the issue of charitable activities in Azerbaijan. Briefly described the history of charitable activities in Azerbaijan. Also shown is the legal framework of charitable activities in Azerbaijan.

  14. Physical Activity Assessment

    Current evidence convincingly indicates that physical activity reduces the risk of colon and breast cancer. Physical activity may also reduce risk of prostate cancer. Scientists are also evaluating potential relationships between physical activity and other cancers.

  15. Bounded Active Perception

    KETENCI, Uktu Gorkem; Bremond, Roland; Auberlet, Jean Michel; GRISLIN, Emmanuelle

    2010-01-01

    There are two kinds of perception : active and passive. This paper is an attempt to take advantage of active perception to improve the agent's perception of relevant information. Through the data filtering capacity, active perception is a useful tool for modeling human-like bounded perception. Using such filters, either the agent or the environment take an active role. We determine several unsolved issues in active perception and do several proposals to implement our concept on the active per...

  16. The fMRI study on the front-parietal activation in abacus mental calculation trained children

    Objective: To investigate the difference in front-parietal activation between the trained and untrained children engaged in addition and multiplication with functional magnetic resonance imaging (fMRI), and to explore the role of abacus mental calculation in brain development. Methods: Twenty-four children trained with abacus mental calculation and twelve untrained children performed mental calculation tasks including addition, multiplication and number-object control judging tasks. Blood oxygenation level dependence (BOLD) fMRI was performed when they were calculating. All data were analyzed by SPM2 (statistical parametric mapping 2) to generate the brain activation map. Results: The performance of the trained group had better correctness and shorter reaction time than that of the untrained group. The front-parietal activation between two groups had obvious difference. The activation involved less prefrontal cortex in the trained group than in the untrained group (P<0.05). The parietal activation in the trained group was mainly in the posterior superior parietal lobe/ precuneus, whereas the activation areas focused on the inferior parietal lobule in the untrained group. Conclusion: Abacus mental calculation involves multiple functional areas. and these areas may work together as a whole in processing arithmetic problems. Abacus mental calculation not only enhances the information processing in some brain areas and improves the utilization efficiency of neural resources, but also plays an important role in developing brain. (authors)

  17. Political activity for physical activity: health advocacy for active transport

    Amun Qa-t-a; Reeder Anthony I; Murdoch Linda; Richards Rosalina

    2011-01-01

    Abstract Effective health advocacy is a priority for efforts to increase population participation in physical activity. Local councils are an important audience for this advocacy. The aim of the current study was to describe features of advocacy for active transport via submissions to city council annual plans in New Zealand, and the impact of an information sheet to encourage the health sector to be involved in this process. Written submissions to city council's annual consultation process w...

  18. Political activity for physical activity: health advocacy for active transport

    Amun Qa-t-a

    2011-05-01

    Full Text Available Abstract Effective health advocacy is a priority for efforts to increase population participation in physical activity. Local councils are an important audience for this advocacy. The aim of the current study was to describe features of advocacy for active transport via submissions to city council annual plans in New Zealand, and the impact of an information sheet to encourage the health sector to be involved in this process. Written submissions to city council's annual consultation process were requested for 16 city councils over the period of three years (2007/08, 2008/09, and 2009/10. Submissions were reviewed and categories of responses were created. An advocacy information sheet encouraging health sector participation and summarising some of the evidence-base related to physical activity, active transport and health was released just prior to the 2009/10 submission time. Over the period of the study, city councils received 47,392 submissions, 17% of which were related to active transport. Most submissions came from city residents, with a small proportion (2% from the health sector. The largest category of submissions was in support of pedestrian and cycling infrastructure, design and maintenance of facilities and additional features to support use of these transport modes. Health arguments featured prominently in justifications for active transport initiatives, including concerns about injury risk, obesity, physical inactivity, personal safety and facilities for people with disabilities. There was evidence that the information sheet was utilised by some health sector submitters (12.5%, providing tentative support for initiatives of this nature. In conclusion, the study provides novel information about the current nature of health advocacy for active transport and informs future advocacy efforts about areas for emphasis, such as health benefits of active transport, and potential alliances with other sectors such as environmental

  19. Persistent active longitudes in sunspot activity

    Berdyugina, S.; Usoskin, I.

    It has been recently shown that spot activity of cool stars including solar analogues, is grouped in two clearly distinguished active longitudes which are persistent within at least one starspot cycle. Solar data including positional information of individual sunspots / groups extends back for about 130 years covering 12 solar cycles. Here we present the results of our research of longitudinal distribution of sunspot activity using an analysis similar to that applied to the stars. First, we synthesized, from the actual sunspot data, the sun's light curve as if it was defined only by spots. Then solar images were calculated from this light curve, giving a natural smoothing of the spot pattern. For each Carrington rotation, longitudinal position of these smoothed spot regions was calculated. The analysis reveals the following main features: - Sunspot activity is grouped in two active longitudes (with the differential rotation taken into account) 180o apart from each other which are persistent through the entire studied period of 12 cycles, similarly to stars. - The longitude migration is determined by changing the mean latitude of sunspot activity (the Maunder butterfly) and differential rotation. - The two longitudes periodically alternate the dominant activity with about 3.7 year period implying for the existence of the Sflip-flopT phenomenon known in - starspot activity.

  20. Increasing Youth Physical Activity with Activity Calendars

    Eckler, Seth

    2016-01-01

    Physical educators often struggle with ways to get their students to be active beyond the school day. One strategy to accomplish this is the use of physical activity calendars (PACs). The purpose of this article is to support the use of PACs and give practical advice for creating effective PACs.

  1. Neutron Activation Analysis

    Corliss, William R.

    1968-01-01

    In activation analysis, a sample of an unknown material is first irradiated (activated) with nuclear particles. In practice these nuclear particles are almost always neutrons. The success of activation analysis depends upon nuclear reactions which are completely independent of an atom's chemical associations. The value of activation analysis as a research tool was recognized almost immediately upon the discovery of artificial radioactivity. This book discusses activation analysis experiments, applications and technical considerations.

  2. Active Player Modelling

    Togelius, Julian; Shaker, Noor; Yannakakis, Georgios N.

    2013-01-01

    We argue for the use of active learning methods for player modelling. In active learning, the learning algorithm chooses where to sample the search space so as to optimise learning progress. We hypothesise that player modelling based on active learning could result in vastly more efficient learning, but will require big changes in how data is collected. Some example active player modelling scenarios are described. A particular form of active learning is also equivalent to an influential forma...

  3. Informal Economic Activities

    Bühn, Andreas

    2010-01-01

    The dissertation “Informal Economic Activities” takes a comprehensive approach to the informal economy by studying traditional shadow economic activities, household DIY activities, and the smuggling of illegal and legal goods. Chapter 2 analyzes shadow economic and DIY activities and presents a dual estimation for the development of both types of informal economic activities in Germany from 1970 to 2005. It also considers the impact of German reunification on shadow economic and DIY activ...

  4. Brain region and activity-dependent properties of M for calibrated fMRI.

    Shu, Christina Y; Herman, Peter; Coman, Daniel; Sanganahalli, Basavaraju G; Wang, Helen; Juchem, Christoph; Rothman, Douglas L; de Graaf, Robin A; Hyder, Fahmeed

    2016-01-15

    Calibrated fMRI extracts changes in oxidative energy demanded by neural activity based on hemodynamic and metabolic dependencies of the blood oxygenation level-dependent (BOLD) response. This procedure requires the parameter M, which is determined from the dynamic range of the BOLD signal between deoxyhemoglobin (paramagnetic) and oxyhemoglobin (diamagnetic). Since it is unclear if the range of M-values in human calibrated fMRI is due to regional/state differences, we conducted a 9.4T study to measure M-values across brain regions in deep (α-chloralose) and light (medetomidine) anesthetized rats, as verified by electrophysiology. Because BOLD signal is captured differentially by gradient-echo (R2*) and spin-echo (R2) relaxation rates, we measured M-values by the product of the fMRI echo time and R2' (i.e., the reversible magnetic susceptibility component), which is given by the absolute difference between R2* and R2. While R2' mapping was shown to be dependent on the k-space sampling method used, at nominal spatial resolutions achieved at high magnetic field of 9.4T the M-values were quite homogenous across cortical gray matter. However cortical M-values varied in relation to neural activity between brain states. The findings from this study could improve precision of future calibrated fMRI studies by focusing on the global uniformity of M-values in gray matter across different resting activity levels. PMID:26529646

  5. Spatio-temporal activity in real time (STAR): optimization of regional fMRI feedback.

    Magland, Jeremy F; Tjoa, Christopher W; Childress, Anna Rose

    2011-04-01

    The use of real-time feedback has expanded fMRI from a brain probe to include potential brain interventions with significant therapeutic promise. However, whereas time-averaged blood oxygenation level-dependent (BOLD) signal measurement is usually sufficient for probing a brain state, the real-time (frame-to-frame) BOLD signal is noisy, compromising feedback accuracy. We have developed a new real-time processing technique (STAR) that combines noise-reduction properties of multi-voxel (e.g., whole-brain) techniques with the regional specificity critical for therapeutics. Nineteen subjects were given real-time feedback in a cognitive control task (imagining repetitive motor activity vs. spatial navigation), and were all able to control a visual feedback cursor based on whole-brain neural activity. The STAR technique was evaluated, retrospectively, for five a priori regions of interest in these data, and was shown to provide significantly better (frame-by-frame) classification accuracy than a regional BOLD technique. In addition to regional feedback signals, the output of the STAR technique includes spatio-temporal activity maps (movies) providing insight into brain dynamics. The STAR approach offers an appealing optimization for real-time fMRI applications requiring an anatomically-localized feedback signal. PMID:21232612

  6. Biophysical model for integrating neuronal activity, EEG, fMRI and metabolism.

    Sotero, Roberto C; Trujillo-Barreto, Nelson J

    2008-01-01

    Our goal is to model the coupling between neuronal activity, cerebral metabolic rates of glucose and oxygen consumption, cerebral blood flow (CBF), electroencephalography (EEG) and blood oxygenation level-dependent (BOLD) responses. In order to accomplish this, two previous models are coupled: a metabolic/hemodynamic model (MHM) for a voxel, linking BOLD signals and neuronal activity, and a neural mass model describing the neuronal dynamics within a voxel and its interactions with voxels of the same area (short-range interactions) and other areas (long-range interactions). For coupling both models, we take as the input to the BOLD model, the number of active synapses within the voxel, that is, the average number of synapses that will receive an action potential within the time unit. This is obtained by considering the action potentials transmitted between neuronal populations within the voxel, as well as those arriving from other voxels. Simulations are carried out for testing the integrated model. Results show that realistic evoked potentials (EP) at electrodes on the scalp surface and the corresponding BOLD signals for each voxel are produced by the model. In another simulation, the alpha rhythm was reproduced and reasonable similarities with experimental data were obtained when calculating correlations between BOLD signals and the alpha power curve. The origin of negative BOLD responses and the characteristics of EEG, PET and BOLD signals in Alzheimer's disease were also studied. PMID:17919931

  7. Disorders of consciousness: Moving from passive to resting state and active paradigms.

    Bruno, M A; Soddu, A; Demertzi, A; Laureys, S; Gosseries, O; Schnakers, C; Boly, M; Noirhomme, Q; Thonnard, M; Chatelle, C; Vanhaudenhuyse, A

    2010-09-01

    Following coma, some patients will recover wakefulness without signs of consciousness (i.e., vegetative state) or may show nonreflexive movements but with no ability for functional communication (i.e., minimally conscious state). Currently, there remains a high rate of misdiagnosis of the vegetative state. The increasing use of fMRI and EEG tools permits the clinical characterization of these patients to be improved. We first discuss "resting metabolism" and "passive activation" paradigms, used in neuroimaging and evoked potential studies, which merely identify neural activation reflecting "automatic" processing-that is, occurring without the patient's willful intervention. Secondly, we present an alternative approach consisting of instructing subjects to imagine well-defined sensory-motor or cognitive-mental actions. This strategy reflects volitional neural activation and, hence, witnesses awareness. Finally, we present results on blood-oxgen-level-dependent "default mode network"/resting state studies that might be a promising tool in the diagnosis of these challenging patients. PMID:24168335

  8. Lectures Abandoned: Active Learning by Active Seminars

    Christensen, Henrik Bærbak; Corry, Aino Vonge

    2012-01-01

    Traditional lecture-based courses are widely criticised for be- ing less eective in teaching. The question is of course what should replace the lectures and various active learning tech- niques have been suggested and studied. In this paper, we report on our experiences of redesigning a software ......- tive seminars as a replacement of traditional lectures, an activity template for the contents of active seminars, an ac- count on how storytelling supported the seminars, as well as reports on our and the students' experiences....

  9. Antifeedant activity of quassinoids.

    Leskinen, V; Polonsky, J; Bhatnagar, S

    1984-10-01

    The antifeedant activity of 13 quassinoids of different structural types has been studied against the Mexican bean beetle (Epilachna varivestis Mulsant) 4th instar larvae and the southern armyworm (Spodoptera eridania Crawer) 5th instar larvae. All quassinoids tested displayed significant activity against the Mexican bean beetle and, thus, do not reveal a simple structure-activity relationship. Five quassinoids were active against the southern armyworm. Interestingly, four of these-bruceantin (I), glaucarubinone (VI), isobruceine A (VIII), and simalikalactone D (XI)-possess the required structural features for antineoplastic activity. The noncytotoxic quassin (X) is an exception; it is active against both pests. PMID:24318349

  10. Functional MRI activity in the thalamus and occipital cortex of anesthetized dogs induced by monocular and binocular stimulation.

    Willis, C K; Quinn, R P; McDonell, W M; Gati, J; Partlow, G; Vilis, T

    2001-07-01

    The neuroanatomy of the mammalian visual system has received considerable attention through electrophysiological study of cats and non-human primates, and through neuroimaging of humans. Canine neuroanatomy, however, has received much less attention, limiting our understanding of canine vision and visual pathways. As an early step in applying blood oxygenation level dependant (BOLD) functional magnetic resonance imaging (fMRI) for veterinary use, we compared visual activity in the thalamus and occipital cortex of anesthetized dogs presented with binocular and monocular visual stimuli. Activity in the left and right thalamus and occipital cortex during monocular stimulation was also compared. Six beagles were presented with a vertical grating visual stimulus and scanned at 4 Tesla. Each dog was scanned twice under each of 3 anesthetic protocols (isoflurane, propofol, and fentanyl/midazolam). We found: 1) significant BOLD activation in the lateral geniculate nucleus (LGN) of the thalamus and the occipital cortex; 2) a significantly larger area of activation in the LGN during monocular stimulation than during binocular stimulation; and 3) that activity in the hemisphere contralateral to the stimulus was not significantly greater than that ipsilateral to it. PMID:11480525

  11. Immunizations: Active vs. Passive

    ... in Action Medical Editor & Editorial Advisory Board Sponsors Sponsorship Opporunities Spread the Word Shop AAP ... Active vs. Passive Page Content Article Body Pediatricians can protect your child by administering not only active immunizations , but sometimes ...

  12. Italian active volcanoes

    RobertoSantacroce; RenawCristofolini; LuigiLaVolpe; GiovanniOrsi; MauroRosi

    2003-01-01

    The eruptive histories, styles of activity and general modes of operation of the main active Italian volcanoes,Etna, Vulcano, Stromboli, Vesuvio, Campi Flegrei and Ischia, are described in a short summary.

  13. Major operations and activities

    This section of the 1994 Hanford Site Environmental Report summarizes the major operations and activities on the site. These operations and activities include site management, waste management, environmental restoration and corrective actions, and research and technology development

  14. Physical Activity and Children

    ... Food and Beverage Toolkit The AHA's Recommendations for Physical Activity in Children Updated:Jul 21,2016 Click image ... Inactive children are likely to become inactive adults. Physical activity helps with: controlling weight reducing blood pressure raising ...

  15. Active Marine Station Metadata

    National Oceanic and Atmospheric Administration, Department of Commerce — The Active Marine Station Metadata is a daily metadata report for active marine bouy and C-MAN (Coastal Marine Automated Network) platforms from the National Data...

  16. Forensic activation analysis

    Basic principles of neutron activation analysis are outlined. Examples of its use in police science include analysis for gunshot residues, toxic element determinations and multielement comparisons. Advantages of neutron activation analysis over other techniques are described. (R.L.)

  17. Family Activities for Fitness

    Grosse, Susan J.

    2009-01-01

    This article discusses how families can increase family togetherness and improve physical fitness. The author provides easy ways to implement family friendly activities for improving and maintaining physical health. These activities include: walking, backyard games, and fitness challenges.

  18. USAID Activity Locatons

    US Agency for International Development — The USAID Activities dataset is a snapshot of activities supported by USAID including their geographical locations within countries at the time of the snapshot. The...

  19. Preschoolers’ Physical Activity Behaviours

    Irwin, Jennifer D.; He, Meizi; Bouck, L. Michelle Sangster; Tucker, Patricia; Pollett, Graham L.

    2016-01-01

    Objectives To understand parents’ perspectives of their preschoolers’ physical activity behaviours. Methods A maximum variation sample of 71 parents explored their preschoolers’ physical activity behaviours through 10 semi-structured focus group discussions. Results Parents perceived Canada’s Physical Activity Guidelines for Children as inadequate; that their preschoolers get and need more than 30–90 minutes of activity daily; and that physical activity habits must be established during the preschool years. Nine barriers against and facilitators toward adequate physical activity were proposed: child’s age, weather, daycare, siblings, finances, time, society and safety, parents’ impact, and child’s activity preferences. Discussion The need for education and interventions that address current barriers are essential for establishing physical activity as a lifestyle behaviour during early childhood and, consequently, helping to prevent both childhood and adulthood obesity. PMID:16625802

  20. Major operations and activities

    Black, D.G.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the major operations and activities on the site. These operations and activities include site management, waste management, environmental restoration and corrective actions, and research and technology development.

  1. Activity-based design

    Andersen, Peter Bøgh

    2006-01-01

      In many types of activities communicative and material activities are so intertwined that the one cannot be understood without taking the other into account. This is true of maritime and hospital work that are used as examples in the paper. The spatial context of the activity is also important:...... and automatic machinery can replace one another in an activity. It also gives an example of how to use the framework for design....

  2. Canonical active Brownian motion

    Gluck, Alexander; Huffel, Helmuth; Ilijic, Sasa

    2008-01-01

    Active Brownian motion is the complex motion of active Brownian particles. They are active in the sense that they can transform their internal energy into energy of motion and thus create complex motion patterns. Theories of active Brownian motion so far imposed couplings between the internal energy and the kinetic energy of the system. We investigate how this idea can be naturally taken further to include also couplings to the potential energy, which finally leads to a general theory of cano...

  3. Woodsy Owl Activity Guide.

    Forest Service (USDA), Washington, DC.

    This guide offers teachers and after-school group leaders 12 fun and engaging activities. Activities feature lessons on trees, water, wind, the earth, food, and waste. The activities are designed to help children aged 5-8 become more aware of the natural environment and fundamental conservation principles. Titles of children's books are embedded…

  4. Activity Theory and Ontology

    Peim, Nick

    2009-01-01

    This paper seeks to re-examine Yrio Engestrom's activity theory as a technology of knowledge designed to enable positive transformations of specific practices. The paper focuses on a key paper where Engestrom defines the nature and present state of activity theory. Beginning with a brief account of the relations between activity theory and…

  5. Repeatability of Detecting Visual Cortex Activity in Functional Magnetic Resonance Imaging

    Mahboubeh Ma'soumbeigi

    2012-03-01

    Full Text Available Introduction As functional magnetic resonance imaging (fMRI is too expensive and time consuming, its frequent implementation is difficult. The aim of this study is to evaluate repeatability of detecting visual cortex activity in fMRI. Materials and Methods In this study, 15 normal volunteers (10 female, 5 male; Mean age±SD: 24.7±3.8 years attended. Functional magnetic resonance images were obtained during a visual task of sine-wave with spatial frequency of 1.84 cpd and temporal frequency of 8 Hz in three scan runs. Two runs of functional images were provided consecutively in a session, and the third run was provided 1-6 weeks later. The activation map was created using the data obtained from the block-designed fMRI study. Voxels whose Z value was above a threshold of 2.3, at a significance level p=0.05, were considered activated. After image processing, the blood oxygen level dependent (BOLD signal changes and the number of activated voxels in response to visual stimuli were compared in different runs. Results The results of this study demonstrate no significant difference between the number of activated voxels and BOLD signal in first and second runs in one session (Paired t-test, p>0.05. Moreover, there is a considerable correlation between first and second scan runs (rsignal=0.74, p=0.006 and rvoxel=0.62, p=0.03, while the correlation between the runs in separate sessions is weak (rsignal=0.28, p=0.38 and rvoxel=0.32, p=0.31. Conclusion Since the repeatability of BOLD signal and number of activated voxels in one session is considerably better than that in the separate sessions, it is suggested that in fMRI visual studies that need repeated scanning, scans should be acquired during a single session.

  6. Recurrent Activity in Active Galactic Nuclei

    Saikia, D J

    2010-01-01

    There has been a growing body of evidence to suggest that AGN activity, which is powered by mass accretion on to a supermasive black hole, could be episodic, although the range of time scales involved needs to be explored further. The structure and spectra of radio emission from radio galaxies, whose sizes range up to $\\sim$5 Mpc, contain information on the history of AGN activity in the source. They thus provide a unique opportunity to study the time scales of recurrent AGN activity. The most striking examples of recurrent activity in radio galaxies and quasars are the double-double or triple-double radio sources which contain two or three pairs of distinct lobes on opposite sides of the parent optical object. Spectral and dynamical ages of these lobes could be used to constrain time scales of episodic activity. Inverse-Compton scattered cosmic microwave background radiation could in principle probe lower Lorentz-factor particles than radio observations of synchrotron emission, and thereby reveal an older po...

  7. Accessibility, activity participation and location of activities

    Næss, Petter

    2006-01-01

    location and the amount of daily-life travel in an urban region. The empirical data are from a comprehensive study of residential location and travel in Copenhagen Metropolitan Area. Differences between inner- and outer-area residents in activity frequencies and trip frequencies are modest and partly......By investigating relationships between residential location and the availability of facilities, location of activities, trip distances, activity participation and trip frequencies, this paper seeks to contribute to a more detailed and nuanced understanding of the relationships between residential...... outweigh each other. However, differences in trip distances due to the location of the dwelling relative to concentrations of facilities translate into substantially longer total travelling distances among suburbanites than among inner-city residents....

  8. Active ageing technologies

    Lassen, Aske Juul

    physical and productive activity; e.g. that a game of billiards is a technology of active aging. Thus, active aging is enacted in the socio-material practices of the technologies in this paper. The paper contributes with a strengthening of the concept of active aging, by focusing on entangled practices and...... elderly. As part of this rearticulation of old age, many new technologies take form. This paper uses a wide concept of technologies (devices, regimes, strategies and ways of doing) and argues that technologies form active aging subjectivities, and on the other hand, that these subjectivities in their...... socio-material practices form active aging. Hence, active aging is a mutual entanglement (Callon and Rabeharisoa 2004) between technologies, practices and subjectivities. The paper is based on four months of participant observations and 17 in-depth interviews with elderly persons conducted at three...

  9. Outreach activities in JAEA

    Under the slogan of 'each staff member is a spokesperson', Japan Atomic Energy Agency (JAEA) holds lectures and science experiment classes at schools, as well as science cafes and open lectures for the general public. Especially at Sector of Fusion Research and Development, 'Katte ni Outreach (voluntary outreach)' activity group, a voluntary group consists of its staff members, plays the central role in its outreach activities. This article describes the system of this outreach activity and the tools for the activity, namely pocketbook, DVD, 3D model of JT-60SA, and so on. Showing the examples of outreach activities conducted nationwide and locally in collaboration with the local communities, the results of the survey conducted in these activities are introduced, also mentioning the future direction of the activity. (S.K.)

  10. Neural Changes following Behavioral Activation for a Depressed Breast Cancer Patient: A Functional MRI Case Study

    Michael J. Gawrysiak

    2012-01-01

    Full Text Available Functional neuroimaging is an innovative but at this stage underutilized method to assess the efficacy of psychotherapy for depression. Functional magnetic resonance imaging (fMRI was used in this case study to examine changes in brain activity in a depressed breast cancer patient receiving an 8-session Behavioral Activation Treatment for Depression (BATD, based on the work of Hopko and Lejuez (2007. A music listening paradigm was used during fMRI brain scans to assess reward responsiveness at pre- and posttreatment. Following treatment, the patient exhibited attenuated depression and changes in blood oxygenation level dependence (BOLD response in regions of the prefrontal cortex and the subgenual cingulate cortex. These preliminary findings outline a novel means to assess psychotherapy efficacy and suggest that BATD elicits functional brain changes in areas implicated in the pathophysiology of depression. Further research is necessary to explore neurobiological mechanisms of change in BATD, particularly the potential mediating effects of reward responsiveness and associated brain functioning.

  11. Evaluation of the Equivalent Radium Activity of Clay Brickworks in Backlands of Paraiba, Brazil

    The natural radioactivity can reach high levels, depending on the geological formation of each area of the planet. Construction materials contain amounts of natural radioactive elements that may have concentrations upper of established limits, varying according to the composition of rock and soil from which they originated, causing greater exposure to human beings through the use of clay as raw material for ceramics used in construction. The radioecology dosimetry of these materials is defined in terms of the Equivalent Radium activity (RaEq). In this context, this study aimed to establish the calculation of RaEq in the raw material of potteries in the badlands of Paraiba, area adjacent to the uranium deposits of Espinharas, to estimate the risks associated with primordial radionuclides attributed to TENORM activities from the extraction and use of clay in manufacture of bricks and tiles. Analysis were performed by high resolution gamma spectrometry with HPGe detector-Be, assuming the state of secular radioactive equilibrium. The results ranged from 84.49 to 747.78 Nq.kg-1, with a mean 333.97 Bq.kg-1. Some samples had values that exceeded the limit of 370 Bq.kg-1 established by UNSCEAR for construction materials, surpassing until on doubled, suggesting greater monitoring and control of these mining areas. (Author)

  12. The activity in the anterior insulae is modulated by perceptual decision-making difficulty.

    Lamichhane, Bidhan; Adhikari, Bhim M; Dhamala, Mukesh

    2016-07-01

    Previous neuroimaging studies provide evidence for the involvement of the anterior insulae (INSs) in perceptual decision-making processes. However, how the insular cortex is involved in integration of degraded sensory information to create a conscious percept of environment and to drive our behaviors still remains a mystery. In this study, using functional magnetic resonance imaging (fMRI) and four different perceptual categorization tasks in visual and audio-visual domains, we measured blood oxygen level dependent (BOLD) signals and examined the roles of INSs in easy and difficult perceptual decision-making. We created a varying degree of degraded stimuli by manipulating the task-specific stimuli in these four experiments to examine the effects of task difficulty on insular cortex response. We hypothesized that significantly higher BOLD response would be associated with the ambiguity of the sensory information and decision-making difficulty. In all of our experimental tasks, we found the INS activity consistently increased with task difficulty and participants' behavioral performance changed with the ambiguity of the presented sensory information. These findings support the hypothesis that the anterior insulae are involved in sensory-guided, goal-directed behaviors and their activities can predict perceptual load and task difficulty. PMID:27095712

  13. Ciguatoxins activate specific cold pain pathways to elicit burning pain from cooling.

    Vetter, Irina; Touska, Filip; Hess, Andreas; Hinsbey, Rachel; Sattler, Simon; Lampert, Angelika; Sergejeva, Marina; Sharov, Anastasia; Collins, Lindon S; Eberhardt, Mirjam; Engel, Matthias; Cabot, Peter J; Wood, John N; Vlachová, Viktorie; Reeh, Peter W; Lewis, Richard J; Zimmermann, Katharina

    2012-10-01

    Ciguatoxins are sodium channel activator toxins that cause ciguatera, the most common form of ichthyosarcotoxism, which presents with peripheral sensory disturbances, including the pathognomonic symptom of cold allodynia which is characterized by intense stabbing and burning pain in response to mild cooling. We show that intraplantar injection of P-CTX-1 elicits cold allodynia in mice by targeting specific unmyelinated and myelinated primary sensory neurons. These include both tetrodotoxin-resistant, TRPA1-expressing peptidergic C-fibres and tetrodotoxin-sensitive A-fibres. P-CTX-1 does not directly open heterologously expressed TRPA1, but when co-expressed with Na(v) channels, sodium channel activation by P-CTX-1 is sufficient to drive TRPA1-dependent calcium influx that is responsible for the development of cold allodynia, as evidenced by a large reduction of excitatory effect of P-CTX-1 on TRPA1-deficient nociceptive C-fibres and of ciguatoxin-induced cold allodynia in TRPA1-null mutant mice. Functional MRI studies revealed that ciguatoxin-induced cold allodynia enhanced the BOLD (Blood Oxygenation Level Dependent) signal, an effect that was blunted in TRPA1-deficient mice, confirming an important role for TRPA1 in the pathogenesis of cold allodynia. PMID:22850668

  14. Impaired Activation in Cognitive Control Regions Predicts Reversal Learning in Schizophrenia.

    Culbreth, Adam J; Gold, James M; Cools, Roshan; Barch, Deanna M

    2016-03-01

    Reinforcement learning deficits have been associated with schizophrenia (SZ). However, the pathophysiology that gives rise to these abnormalities remains unclear. To address this question, SZ patients (N = 58) and controls (CN; N = 36) completed a probabilistic reversal-learning paradigm during functional magnetic resonance imaging scanning. During the task, participants choose between 2 stimuli. Initially, 1 stimulus was frequently rewarded (80%); the other was infrequently rewarded (20%). The reward contingencies reversed periodically because the participant learned the more rewarded stimulus. The results indicated that SZ patients achieved fewer reversals than CN, and demonstrated decreased winstay-loseshift decision-making behavior. On loseshift compared to winstay trials, SZ patients showed reduced Blood Oxygen Level Dependent activation compared to CN in a network of brain regions widely associated with cognitive control, and striatal regions. Importantly, relationships between group membership and behavior were mediated by alterations in the activity of cognitive control regions, but not striatum. These findings indicate an important role for the cognitive control network in mediating the use and updating of value representations in SZ. Such results provide biological targets for further inquiry because researchers attempt to better characterize decision-making neural circuitry in SZ as a means to discover new pathways for interventions. PMID:26049083

  15. CHANGES IN LEVELS OF ACTIVITY OF SERINE PROTEASES ACCOMPANY THE EXPOSURE OF COMMON BEAN (PHASEOLUS VULGARIS L. TO WATER DEFICIT

    M. Budič

    2008-09-01

    Full Text Available A wide variety of proteolytic enzymes exist in plants. On their levels depends protein turnover, a fundamental component in plant development and adaptation to environmental conditions. Cysteine proteases have frequently been reported to be influenced by drought, but only a few serine proteases (SP, among them the trypsin-like enzyme and two aminopeptidases from bean leaves (Bartels and Sunkar, 2005; Hieng et al., 2004. Our starting point was to identify proteolytic activities assigned to SPs that change with drought and then to characterize the corresponding proteases. A quantitative, analytical one-step method was used to separate endopeptidases and aminopeptidases active against a range of substrates in leaf extracts of plants grown in the field (FC. The influence of drought was determined for those of these activities which were confirmed as SPs, based on their inhibition by specific inhibitors. Under water deficit in plants grown under controlled conditions (CC their levels changed in different ways. The levels of SP activities in FC plants, observed during a period of relative drought, were similar to those measured in mildly stressed CC plants. The partial characterisations of some of these SPs will be presented. Our results point to a number of roles for different SPs in the plant response to water stress, which could range from enhanced protein turnover to limited proteolysis at specific sites.

  16. Altered baseline brain activities before food intake in obese men: a resting state fMRI study.

    Zhang, Bin; Tian, Derun; Yu, Chunshui; Zhang, Jing; Tian, Xiao; von Deneen, Karen M; Zang, Yufeng; Walter, Martin; Liu, Yijun

    2015-01-01

    Obesity as a chronic disease has become a global epidemic. However, why obese individuals eat more still remains unclear. Recent functional neuroimaging studies have found abnormal brain activations in obese people. In the present study, we used resting state functional MRI to observe spontaneous blood-oxygen-level dependent (BOLD) signal fluctuations during both hunger and satiety states in 20 lean and 20 obese men. Using a regional homogeneity (ReHo) analysis method, we measured temporal homogeneity of the regional BOLD signals. We found that, before food intake, obese men had significantly increased synchronicity of activity in the left putamen relative to lean men. Decreased synchronicity of activity was found in the orbitofrontal cortex (OFC) and medial prefrontal cortex(MPFC) in the obese subjects. And, the ratings of hunger of the obese subjects were higher than those of the lean subjects before food intake. After food intake, we did not find the significant differences between the obese men and the lean men. In all participations, synchronicity of activity increased from the fasted to the satiated state in the OFC. The results indicated that OFC plays an important role in feeding behavior, and OFC signaling may be disordered in obesity. Obese men show less inhibitory control during fasting state. This study has provided strong evidence supporting the hypothesis that there is a hypo-functioning reward circuitry in obese individuals, in which the frontal cortex may fail to inhibit the striatum, and consequently lead to overeating and obesity. PMID:25459293

  17. The Active Reader: What Is Active?

    van Woerkum, Cees

    2012-01-01

    How writers can adapt to their readers is an important issue in effective communication strategies, and certainly crucial in the case of functional texts. Therefore, it is necessary to look at how readers are constructed as partners in a communication co-production. This article explores the concept of the "active reader," which is getting more…

  18. NEA activities in 1980. 9. Activity Report

    This report describes the main features of the Agency's work during 1980 and discusses the state and prospects of the nuclear industry in OECD countries. Trends in nuclear power, radiological and environmental impacts of nuclear fuel cycle activities, nuclear safety research and licensing, nuclear law, nuclear development and fuel cycle studies technical co-operation, nuclear science organisation and administration are reviewed

  19. Active knee joint flexibility and sports activity

    Hahn, Thomas; Foldspang, Anders; Vestergaard, E;

    1999-01-01

    significantly higher in women than in men and significantly positively associated with weekly hours of swimming and weekly hours of competitive gymnastics. Active knee flexion was significantly positively associated with participation in basketball, and significantly negatively associated with age and weekly...

  20. Differences in neural activity when processing emotional arousal and valence in autism spectrum disorders.

    Tseng, Angela; Wang, Zhishun; Huo, Yuankai; Goh, Suzanne; Russell, James A; Peterson, Bradley S

    2016-02-01

    Individuals with autism spectrum disorders (ASD) often have difficulty recognizing and interpreting facial expressions of emotion, which may impair their ability to navigate and communicate successfully in their social, interpersonal environments. Characterizing specific differences between individuals with ASD and their typically developing (TD) counterparts in the neural activity subserving their experience of emotional faces may provide distinct targets for ASD interventions. Thus we used functional magnetic resonance imaging (fMRI) and a parametric experimental design to identify brain regions in which neural activity correlated with ratings of arousal and valence for a broad range of emotional faces. Participants (51 ASD, 84 TD) were group-matched by age, sex, IQ, race, and socioeconomic status. Using task-related change in blood-oxygen-level-dependent (BOLD) fMRI signal as a measure, and covarying for age, sex, FSIQ, and ADOS scores, we detected significant differences across diagnostic groups in the neural activity subserving the dimension of arousal but not valence. BOLD-signal in TD participants correlated inversely with ratings of arousal in regions associated primarily with attentional functions, whereas BOLD-signal in ASD participants correlated positively with arousal ratings in regions commonly associated with impulse control and default-mode activity. Only minor differences were detected between groups in the BOLD signal correlates of valence ratings. Our findings provide unique insight into the emotional experiences of individuals with ASD. Although behavioral responses to face-stimuli were comparable across diagnostic groups, the corresponding neural activity for our ASD and TD groups differed dramatically. The near absence of group differences for valence correlates and the presence of strong group differences for arousal correlates suggest that individuals with ASD are not atypical in all aspects of emotion-processing. Studying these similarities

  1. Distinct BOLD activation profiles following central and peripheral oxytocin administration in awake rats

    Craig F Ferris

    2015-09-01

    Full Text Available A growing body of literature has suggested that intranasal oxytocin (OT or other systemic routes of administration can alter prosocial behavior, presumably by directly activating OT sensitive neural circuits in the brain. Yet there is no clear evidence that OT given peripherally can cross the blood-brain-barrier at levels sufficient to engage the OT receptor. To address this issue we examined changes in blood oxygen level dependent (BOLD signal intensity in response to peripheral OT injections (0.1, 0.5 or 2.5 mg/kg during functional magnetic resonance (fMRI in awake rats imaged at 7.0 tesla. These data were compared to OT (1ug/5 µl given directly to the brain via the lateral cerebroventricle. Using a 3D annotated MRI atlas of the rat brain segmented into 171 brain areas and computational analysis we reconstructed the distributed integrated neural circuits identified with BOLD fMRI following central and peripheral OT. Both routes of administration caused significant changes in BOLD signal within the first 10 min of administration. As expected, central OT activated a majority of brain areas known to express a high density of OT receptors e.g., lateral septum, subiculum, shell of the accumbens, bed nucleus of the stria terminalis. This profile of activation was not matched by peripheral OT. The change in BOLD signal to peripheral OT did not show any discernible dose-response. Interestingly, peripheral OT affected all subdivisions of the olfactory bulb, in addition to the cerebellum and several brainstem areas relevant to the autonomic nervous system, including the solitary tract nucleus. The results from this imaging study do not support a direct central action of peripheral OT on the brain. Instead, the patterns of brain activity suggest that peripheral OT may interact at the level of the olfactory bulb and through sensory afferents from the autonomic nervous system to influence brain activity.

  2. Poverty And Civic Activism

    William R. DiPietro

    2013-01-01

    This paper hypothesizes that country poverty is negatively associated with the civic activism of its citizens. It employs cross country regression analysis to test the proposition. In general, the findings of the paper lend support to the contention that greater civic activism leads to reduced poverty.Poverty is a worldwide problem. One of the possible ways that pressure can be brought to bear to change a countrys policies, institutions, attitudes, and beliefs is through civic activism and pr...

  3. Active Travel - Healthy Lives

    Institute of Public Health in Ireland

    2011-01-01

    Across Ireland, there is considerable scope to replace many short car journeys with walking and cycling which would bring about a range of benefits to health as well as saving money for individuals and society.'Active travel, healthy lives' presents a summary of international evidence on the health and economic benefits of active travel and makes recommendations on how active travel can become a viable, safe and attractive alternative to car use.

  4. Confinement for Active Objects

    Florian Kammuller

    2014-01-01

    In this paper, we provide a formal framework for the security of distributed active objects. Active objects com-municate asynchronously implementing method calls via futures. We base the formal framework on a security model that uses a semi-lattice to enable multi-lateral security crucial for distributed architectures. We further provide a security type system for the programming model ASPfun of functional active objects. Type safety and a confinement property are presented. ASPfun thus reali...

  5. Lupus Activity in Pregnancy

    Clowse, Megan E. B.

    2007-01-01

    Pregnancy in a woman with Systemic Lupus Erythematosus (SLE) can be complicated by both lupus activity and pregnancy mishaps. The majority of recent studies demonstrate an increase in lupus activity during pregnancy, perhaps exacerbated by hormonal shifts required to maintain pregnancy. Increased lupus activity, in turn, prompts an elevated risk for poor pregnancy outcomes, including stillbirth, preterm birth, low birth weight, and preeclamspsia. Fortunately, the majority of pregnancies in wo...

  6. Activated carbons and gold

    The literature on activated carbon is reviewed so as to provide a general background with respect to the effect of source material and activation procedure on carbon properties, the structure and chemical nature of the surface of the activated carbon, and the nature of absorption processes on carbon. The various theories on the absorption of gold and silver from cyanide solutions are then reviewed, followed by a discussion of processes for the recovery of gold and silver from cyanide solutions using activated carbon, including a comparison with zinc precipitation

  7. CDBG Public Improvements Activity

    Department of Housing and Urban Development — CDBG activity related to public improvements, including senior centers, youth centers, parks, street improvements, water/sewer improvements, child care centers,...

  8. CDBG Housing Activity

    Department of Housing and Urban Development — CDBG activity related to housing, including multifamily rehab, housing services, code enforcement, operation and repair of foreclosed property and public housing...

  9. CDBG Economic Development Activity

    Department of Housing and Urban Development — CDBG activity related to economic development, including commercial or industrial rehab, commercial or industrial land acquisition, commercial or industrial...

  10. Vibrational optical activity

    Recent vibrational activity (VOA) research is discussed. The vibrational circular dichroism (VCD) experiments were carried out with a Fourier transform infrared spectrometer. One of the major anticipations from VOA spectroscopy is to be able to derive new pathways for determining the molecular structure. Shown is Fourier transform infrared absorption and VCD spectra of lyxopyranose in pyradine-d5 solvent. Raman optical activity measurements are discussed, and depolarized Raman and Raman optical activity spectra for (+)-alpha-pinene are presented. It was concluded that at present Raman optical activity can be measured in the entire vibrational spectral region, where as VCD has not been measured below 600 cm-1

  11. CDBG Public Services Activity

    Department of Housing and Urban Development — CDBG activity related to public services, including senior services, legal services, youth services, employment training, health services, homebuyer counseling,...

  12. Exercise and activity - children

    ... child's preferences and abilities. Individual activities include swimming, running, skiing, or biking. Group sports are another option, such as soccer, football, basketball, karate, or tennis. Choose an exercise ...

  13. Who is actively denitrifying in activated sludge?

    Hansen, Aviaja Anna; Nielsen, Jeppe Lund

    -scale wastewater treatment plant the transcripts (mRNA) of the nirS, nirK and nosZ denitrification genes expressed under acetate or amino acid consumption were amplified, sequenced and identified. This revealed that the majority of the denitrifiers belonged to Alpha- and Betaproteobacteria, while only few...... genetic diversity was observed from the nirS transcripts and not the nosZ transcripts. Likewise, denitrifying cultures obtained from the activated sludge affiliated with the same Alpha- and Betaproteobacteria as detected with the denitrification genes, except one culture, which affiliated with...... Bacteroidetes. Furthermore, potential denitrifying genera of Alpha- and Betaproteobacteria were quantified in the activated sludge with 16S rRNA gene probes for fluorescence in situ hybridization (FISH). This revealed that Aquaspirillum-related bacteria were dominant followed by bacteria related to Azoarcus...

  14. NEA activities in 1983. 12. Activity report

    This report describes the main features of the Agency's work during 1983 and discusses the state and prospects of the nuclear industry in OECD countries. Trends in nuclear power, nuclear development and the fuel cycles nuclear safety technology and licensing, radiological and environmental impacts of nuclear fuel cycle activities, legal affairs, nuclear science, joint undertakings and other NEA joint projects, organisation and administration are reviewed

  15. HYDRATION AND ENZYME ACTIVITY

    Poole, P.

    1984-01-01

    Hydration induced conformation and dynamic changes are followed using a variety of experimental techniques applied to hen egg white lysozyme. These changes are completed just before the onset of enzyme activity, which occurs before all polar groups are hydrated, and before monolayer coverage is attained. We suggest that these hydration induced changes are necessary for the return of enzyme activity.

  16. Plasminogen activation in cancer

    Reijerkerk, Arie

    2004-01-01

    The subject of this thesis focusses on the role of the plasminogen activation system in angiogenesis and cancer. The plasminogen activation system regulates fibrinolysis and controls cell migration and invasion by plasmin-mediated matrix proteolysis. Plasmin is formed upon cleavage of the zymogen pl

  17. NEA activities in 1982

    This report presents an account of the activities of the Nuclear Energy Agency. It deals with current nuclear trends, nuclear development and the fuel cycle, nuclear safety research and licensing, radiological and environmental impacts of nuclear fuel cycle activities, legal affairs, nuclear science, joint undertakings, and, organization and administration

  18. RTE activity report 2005

    The RTE (electric power transport network) is the french manger of the electric power transport. This activity report provides information on the company results for the year 2005: panorama of the year, management and organization, the place of RTE in the european market, the customers, the industrial tool, the environment the human resources, the international activity and the management report. (A.L.B.)

  19. Warm-Up Activities.

    Mingguang, Yang

    1999-01-01

    Discusses how warm-up activities can help to make the English-as-a-foreign-language classroom a lively and interesting place. Warm-up activities are games carried out at the beginning of each class to motivate students to make good use of class time. (Author/VWL)

  20. Activity report 2002

    This annual report deals with the activities, the program management and the financial aspects of the ANDRA (National Agency for the radioactive wastes management) during 2002. After a presentation of the activities during the year 2002, it provides the financial accounting, data on company cash, the ANDRA missions and publications. (A.L.B.)

  1. Reflections on Activity Theory

    Bakhurst, David

    2009-01-01

    It is sometimes suggested that activity theory represents the most important legacy of Soviet philosophy and psychology. But what exactly "is" activity theory? The canonical account in the West is given by Engestrom, who identifies three stages in the theory's development: from Vygotsky's insights, through Leontiev's articulation of the…

  2. Laboratory Activities in Israel

    Mamlok-Naaman, Rachel; Barnea, Nitza

    2012-01-01

    Laboratory activities have long had a distinctive and central role in the science curriculum, and science educators have suggested that many benefits accrue from engaging students in science laboratory activities. Many research studies have been conducted to investigate the educational effectiveness of laboratory work in science education in…

  3. [Field Learning Activities].

    Nolde Forest Environmental Education Center, Reading, PA.

    Seventy field activities, pertinent to outdoor, environmental studies, are described in this compilation. Designed for elementary and junior high school students, the activities cover many discipline areas--science, social studies, language arts, health, history, mathematics, and art--and many are multidisciplinary in use. Topics range from soil…

  4. Rainy Day Activities.

    Texas Child Care, 1997

    1997-01-01

    Experienced caregivers plan ahead for rainy days. This article describes specific rainy day activities for young children, such as books and crafts to learn about rain (rain in a jar, making a rainbow), simple cooking activities (taffy pull, cinnamon candy tea), and games (mummy wrap, hunt the thimble, rain lotto). (EV)

  5. Peak Longevity Physical Activity

    People who engage in three to five times the recommended minimum level of leisure-time physical activity derive the greatest benefit in terms of mortality reduction when compared with people who do not engage in leisure-time physical activity.

  6. Habitats, activities, and signs

    Andersen, Peter Bøgh; Brynskov, Martin

    2004-01-01

    Digital habitats is a framework for designing and modeling environments for activities that involve mobile and embedded computing systems. This paper 1) introduces the basic concepts of the framework, i.e. activity, thematic role, and the three ‘dimensions’ of a habitat: physical, informational, ...

  7. The Activity of Trypsin

    Russo, Salvatore F.; Holzman, Tom

    1977-01-01

    Describes an experiment that illustrates the following points concerning the experimental determination of trypsin activity: (1) there is a difference in basing enzyme concentration on weight, absorbance, or active sites; and (2) the method of expressing enzyme concentration determines the value of specific, molecular, and catalytic center…

  8. Physical activity among adolescents

    Henriksen, P W; Ingholt, L; Rasmussen, M;

    2015-01-01

    The objectives of this study were (a) to examine the association between various kinds of parental social support and adolescents' physical activity (PA) and (b) to examine whether various kinds of social support from mothers and fathers were differently associated with boys' and girls' PA. Data...... understand why some adolescents are physically active and others are not....

  9. ANDRA, 2006 activity report

    The French national agency of radioactive waste management (ANDRA) was marked in 2006 by two outstanding events: the publication of the national inventory of radioactive wastes and valorisable materials, and the vote of the law from June 28, 2006 relative to the sustainable management of radioactive wastes and materials. This road-map law has an impact on ANDRA's activities for the coming years. This activity report presents several 2006 highlights of ANDRA's missions as well: the public service mission, the by-law about the effluents of the Aube plant for the storage of low-medium activity wastes, the building of the first 'double-cell' at the very-low activity waste storage plant of Aube, the research studies about the project of deep underground disposal of high-medium activity, long-living wastes, and the public information about ANDRA's technical and scientific know-how. The management and financial reports are attached in appendix. (J.S.)

  10. Risk informed maintenance activity

    In recent years, risk informed activities are being investigated as scientifically rational measures. Some Risk informed activities using Core Damage Frequency (CDF) have been already employed. Examples are extraction of accident management strategies, risk informed maintenance importance and such. This paper describes risk information such as CDF, risk profile, risk importance of equipments' contribution to risk, gained from Probabilistic Analysis (PSA). Furthermore, risk informed activities conducted and/or considered are also introduced. The examples are investigation of accident management strategies, on-line maintenance and risk informed In Service Inspection (ISI). In the end, open issues for further employment of risk information in the NPP activities are summarized. Technical quality of PSA methodology is one of these issues and it should be continuously addressed, however, the risk information as it is still useful for better activities in NPP. (author)

  11. Determinants of Physical Activity in Active and Low-Active, Sixth Grade African-American Youth.

    Trost, Stewart G.; Pate, Russell R.; Ward, Dianne S.; Saunders, Ruth; Riner, William

    1999-01-01

    Compared determinants of physical activity in active and low-active African-American sixth graders, surveying students and making objective assessments of physical activity over seven days. Results indicated that physical activity self-efficacy, beliefs about physical activity outcomes, involvement in community-based physical activity, perception…

  12. GOVERNOR ORGANIZATIONS ACTIVITY LICENSING

    Maslennikova L. V.

    2015-03-01

    Full Text Available The author analyses the licensing of governor organizations activity in connection with amendments to the Housing Code of the Russian Federation by adoption of a Federal law of 21.07.2014 N 255-FZ «On amendments to the Housing Code of the Russian Federation, some legislative acts of the Russian Federation and on declare force Certain Provisions of Legislative Acts of the Russian Federation void » and the Government Resolution adoption of the of 28.10.2014г. N 1110 «On entrepreneur activity in apartment buildings’ government licensing». The urgency of the issue of the apartment buildings licensing activity is associated with the modernization of housing and communal services and legal regulation in this area. Introduction of the governor organizations activity licensing without securing in law the concept of "governor organizations" is a significant flaw of the legislator. As a result, the author gives the concept of governor organizations based on the analysis of scientific papers and current legislation. In addition, the article analyzes the introduction of licensing control, assesses the established order of the three registers on the governor organizations activity. The presented paper examines the experience of foreign countries associated with the activities on the apartment building common property management as well, and the state control over such activity. The authors examine violations of housing legislation that may cause the governor organizations and their officials’ administrative responsibility

  13. Mental activity during sleep.

    Fagioli, Igino

    2002-08-01

    Since remote antiquity humankind has believed in the supernatural origin of dreaming. The scientific approach to mental activity during sleep dates back to the eighteenth century. One hundred years ago, psychoanalysis introduced dream analysis for diagnostic and therapeutic purposes. Only 50 years ago psychophysiology made it possible to collect mental sleep activity by means of experimental awakenings while monitoring physiological variables; this approach encouraged investigation into the relationship between the features of sleep activity and sleep state (REM versus NREM). Advances in neurophysiology, in neurochemistry, and recently in brain imaging techniques, have shed light on the roles played by the different cerebral structures in determining specific characteristics of mental activity during sleep. The development of cognitive psychology has enabled investigation of dream generation in terms of output from a complex multilevel system of information processing. In addition to sleep state, other factors, such as the time of the night and the sequence of the NREM-REM cycles, have been shown to influence the characteristics of mental activity. The usefulness of investigation of mental sleep activity as a clinical tool is controversial. The psychophysiological approach to mental sleep activity in clinical contexts has enabled the exploration of adaptation processes and contributed to neuropsychological studies on focal and systemic brain pathology. PMID:12531134

  14. Emotionally Intense Science Activities

    King, Donna; Ritchie, Stephen; Sandhu, Maryam; Henderson, Senka

    2015-08-01

    Science activities that evoke positive emotional responses make a difference to students' emotional experience of science. In this study, we explored 8th Grade students' discrete emotions expressed during science activities in a unit on Energy. Multiple data sources including classroom videos, interviews and emotion diaries completed at the end of each lesson were analysed to identify individual student's emotions. Results from two representative students are presented as case studies. Using a theoretical perspective drawn from theories of emotions founded in sociology, two assertions emerged. First, during the demonstration activity, students experienced the emotions of wonder and surprise; second, during a laboratory activity, students experienced the intense positive emotions of happiness/joy. Characteristics of these activities that contributed to students' positive experiences are highlighted. The study found that choosing activities that evoked strong positive emotional experiences, focused students' attention on the phenomenon they were learning, and the activities were recalled positively. Furthermore, such positive experiences may contribute to students' interest and engagement in science and longer term memorability. Finally, implications for science teachers and pre-service teacher education are suggested.

  15. No difference in frontal cortical activity during an executive functioning task after acute doses of aripiprazole and haloperidol

    Ingeborg eBolstad

    2015-05-01

    Full Text Available Background: Aripiprazole is an atypical antipsychotic drug that is characterized by partial dopamine D2 receptor agonism. Its pharmacodynamic profile is proposed to be beneficial in the treatment of cognitive impairment, which is prevalent in psychotic disorders. This study compared brain activation characteristics produced by aripiprazole with that of haloperidol, a typical D2 receptor antagonist, during a task targeting executive functioning.Methods: Healthy participants received an acute oral dose of haloperidol, aripiprazole or placebo before performing an executive functioning task while blood-oxygen-level-dependent (BOLD functional magnetic resonance imaging (fMRI was carried out. Results: There was a tendency towards reduced performance in the aripiprazole group compared to the two other groups. The image analysis yielded a strong task-related BOLD-fMRI response within each group. An uncorrected between-group analysis showed that aripiprazole challenge resulted in stronger activation in the frontal and temporal gyri and the putamen compared with haloperidol challenge, but after correcting for multiple testing there was no significant group difference. Conclusion: No significant group differences between aripiprazole and haloperidol in frontal cortical activation were obtained when corrected for multiple comparisons.This study is registered in ClinicalTrials.gov (identifier: 2009-016222-14; https://clinicaltrials.gov/.

  16. A Preliminary Study of Functional Brain Activation among Marijuana Users during Performance of a Virtual Water Maze Task

    Jennifer Tropp Sneider

    2013-01-01

    Full Text Available Numerous studies have reported neurocognitive impairments associated with chronic marijuana use. Given that the hippocampus contains a high density of cannabinoid receptors, hippocampal-mediated cognitive functions, including visuospatial memory, may have increased vulnerability to chronic marijuana use. Thus, the current study examined brain activation during the performance of a virtual analogue of the classic Morris water maze task in 10 chronic marijuana (MJ users compared to 18 nonusing (NU comparison subjects. Imaging data were acquired using blood oxygen level-dependent (BOLD functional MRI at 3.0 Tesla during retrieval (hidden platform and motor control (visible platform conditions. While task performance on learning trials was similar between groups, MJ users demonstrated a deficit in memory retrieval. For BOLD fMRI data, NU subjects exhibited greater activation in the right parahippocampal gyrus and cingulate gyrus compared to the MJ group for the Retrieval-Motor Control contrast (NU > MJ. These findings suggest that hypoactivation in MJ users may be due to differences in the efficient utilization of neuronal resources during the retrieval of memory. Given the paucity of data on visuospatial memory function in MJ users, these findings may help elucidate the neurobiological effects of marijuana on brain activation during memory retrieval.

  17. A preliminary study of functional brain activation among marijuana users during performance of a virtual water maze task.

    Sneider, Jennifer Tropp; Gruber, Staci A; Rogowska, Jadwiga; Silveri, Marisa M; Yurgelun-Todd, Deborah A

    2013-01-01

    Numerous studies have reported neurocognitive impairments associated with chronic marijuana use. Given that the hippocampus contains a high density of cannabinoid receptors, hippocampal-mediated cognitive functions, including visuospatial memory, may have increased vulnerability to chronic marijuana use. Thus, the current study examined brain activation during the performance of a virtual analogue of the classic Morris water maze task in 10 chronic marijuana (MJ) users compared to 18 non-using (NU) comparison subjects. Imaging data were acquired using blood oxygen-level dependent (BOLD) functional MRI at 3.0 Tesla during retrieval (hidden platform) and motor control (visible platform) conditions. While task performance on learning trials was similar between groups, MJ users demonstrated a deficit in memory retrieval. For BOLD fMRI data, NU subjects exhibited greater activation in the right parahippocampal gyrus and cingulate gyrus compared to the MJ group for the Retrieval - Motor control contrast (NU > MJ). These findings suggest that hypoactivation in MJ users may be due to differences in the efficient utilization of neuronal resources during the retrieval of memory. Given the paucity of data on visuospatial memory function in MJ users, these findings may help elucidate the neurobiological effects of marijuana on brain activation during memory retrieval. PMID:23951549

  18. Mycorrhizal dependency of mangaba tree under increasing phosphorus levels Dependência micorrízica de mangabeira em doses crescentes de fósforo

    Júlio Alves Cardoso Filho

    2008-07-01

    Full Text Available The objective of this study was to evaluate the mycorrhizal dependency of mangaba tree (Hancornia speciosa plantlets, under increasing levels of phosphorus fertilization. The experimental design was completely randomized in a 4×5 factorial arrangement with three mycorrhizal fungi inocula - Gigaspora margarita, Glomus etunicatum, or a pool of native mycorrhizal fungi (Acaulospora longula, Glomus clarum, Gigaspora albida, Paraglomus sp. -, and a nonmycorrhizal control, in combination with five levels of phosphorus applied to the substrate: 0, 25, 50, 75, and 100 mg kg-1. After 180 days of growth, plantlets with inoculation of native mycorrhizal pool produced more shoot and root dry biomass and had higher shoot phosphorus content and accumulation. The noninoculated control showed the lowest values, independently of the phosphorus level. The highest relative mycorrhizal dependency occurred with the inoculation of native mycorrhizal fungi. Plants with mycorrhizal fungi did not respond to phosphorus addition above 50 mg kg-1. Mangaba tree is highly dependent on mycorrhiza, but the degree of dependency varies according to phosphorus levels and fungal inocula. In general, mangaba tree is more responsive to mycorrhizal fungi inoculation than to phosphorus addition.O objetivo deste trabalho foi avaliar a dependência micorrízica de mudas de mangaba (Hancornia speciosa, em doses crescentes de fósforo. O delineamento experimental foi inteiramente casualizado, em arranjo fatorial 4´5 com três inóculos de fungos micorrízicos - Gigaspora margarita, Glomus etunicatum, ou uma mistura de espécies de fungos micorrízicos nativos (Acaulospora longula, Glomus clarum, Gigaspora albida e Paraglomus sp. -, e um controle não micorrízico, combinados a cinco doses de fósforo no substrato: 0, 25, 50, 75 e 100 mg kg-1. Após 180 dias, as mudas com inoculação dos fungos micorrízicos nativos produziram mais biomassa seca de parte aérea e raízes e apresentaram maior concentração e acúmulo de fósforo na parte aérea. O controle sem inóculo apresentou os menores valores, independentemente da dose de fósforo. A maior dependência micorrízica relativa ocorreu com a inoculação de fungos micorrízicos nativos. Plantas com inoculação micorrízica não responderam à adição de fósforo, em doses acima de 50 mg kg-1. A mangabeira é altamente dependente de micorrizas, mas o grau de dependência varia de acordo com os níveis de fósforo e com os inóculos fúngicos. Em geral, a mangabeira é mais responsiva à inoculação com fungos micorrízicos do que à adição de fósforo.

  19. Assessing the end-organ in peripheral arterial occlusive disease—from contrast—enhanced ultrasound to blood-oxygen-level-dependent MR imaging

    Aschwanden, Markus; Partovi, Sasan; Jacobi, Bjoern; Fergus, Nathan; Schulte, Anja-Carina; Robbin, Mark R; Bilecen, Deniz; Staub, Daniel

    2014-01-01

    Peripheral arterial occlusive disease (PAOD) is a result of atherosclerotic disease which is currently the leading cause of morbidity and mortality in the western world. Patients with PAOD may present with intermittent claudication or symptoms related to critical limb ischemia. PAOD is associated with increased mortality rates. Stenoses and occlusions are usually detected by macrovascular imaging, including ultrasound and cross-sectional methods. From a pathophysiological view these stenoses ...

  20. Correlation between single-trial visual evoked potentials and the blood oxygenation level dependent response in simultaneously recorded electroencephalography-functional magnetic resonance imaging

    Fuglø, Dan; Pedersen, Henrik; Rostrup, Egill;

    2012-01-01

    dependent variations in different occipital and extraoccipital cortical areas not explained by the boxcar regressor. The results suggest that the P1-N2 regressor is the best EEG-based regressor to model the visual paradigm, but when looking for additional effects like habituation or attention modulation...

  1. Regional placental blood oxygen level dependent (BOLD) changes with gestational age in normally developing pregnancies using long duration R2* mapping in utero

    Dighe, Manjiri; Kim, Yun Jung; Seshamani, Sharmishtaa; Blazejewska, Ania I.; Mckown, Susan; Caucutt, Jason; Gatenby, Christopher; Studholme, Colin

    2016-03-01

    The aim of this study was to examine the use of R2* mapping in maternal and fetal sub-regions of the placenta with the aim of providing a reference for blood oxygenation levels during normative development. There have been a number of MR relaxation studies of placental tissues in-utero, but none have reported R2* value changes with age, or examined differences in sub-regions of the placenta. Here specialized long-duration Multi-frame R2* imaging was used to create a stable estimate for R2* values in different placental regions in healthy pregnant volunteers not imaged for clinical reasons. 27 subjects were recruited and scanned up to 3 times during their pregnancy. A multi-slice dual echo EPI based BOLD acquisition was employed and repeated between 90 and 150 times over 3 to 5 minutes to provide a high accuracy estimate of the R2* signal level. Acquisitions were also repeated in 13 cases within a visit to evaluate reproducibility of the method in a given subject. Experimental results showed R2* measurements were highly repeatable within a visit with standard deviation of (0.76). Plots of all visits against gestational age indicated clear correlations showing decreases in R2* with age. This increase was consistent was also consistent over time in multiple visits of the same volunteer during their pregnancy. Maternal and fetal regional changes with gestational age followed the same trend with increase in R2* over the gestational age.

  2. The Dopants and Doping Level Dependence of the Structure and Magnetic Properties of the Eu (BA1-xLRx)2Cu3O7+Theta

    Yu Lin

    2002-12-31

    Eu(Ba{sub 1-x}Nd{sub x}){sub 2}Cu{sub 3}O{sub 7+{delta}} were systematically studied in order to understand how the valence of the rear earth elements, ionic sizes and magnetic moment affect the crystal structure and magnetic and electrical properties. Differential thermal analyses were carried out to check the phase purity, X-ray data were least-squares fitted to determine the lattice parameters, and DC-SQUID magnetometry was used to characterize the superconducting properties. These results showed that the crystallography is consistent with other EuLR123ss series, LR = La, Pr, Eu. The lattice parameters vary with the ionic radii of the rare earth ions. Unlike the uniform change in lattice parameter, the superconducting transition did not vary systematically with the ionic size of the dopants. Although the general trend was for T{sub c} to decrease with decreasing ionic size of the dopant, for the same doping level, Pr was anomalous, depressing T{sub c} faster. Although the exact mechanism is not clear, this result is consistent with the depression of T{sub c} for Pr substitution for the rare earth in R123. The critical current J{sub c} was determined using the Bean model from magnetization versus field measurements as a function of temperature and field. The effect of the dopants on J{sub c} with the increasing of temperature or applied field was determined. For T < 77 K and small values of x, the value of J{sub c} was increased over that of the x = 0 sample. In addition, the smaller the substituting atom, the higher the J{sub c} becomes. For instance, at x = 0.025, Eu123 < EuLa.025 < EuPr.025 < EuNd.025 < EuEu.025. The enhancement of J{sub c} disappears for x > 0.05 and T > 0.5T{sub c}.

  3. Blood oxygenation level-dependent magnetic resonance imaging during carbogen breathing: differentiation between prostate cancer and benign prostate hyperplasia and correlation with vessel maturity

    Wang, Bin

    2016-01-01

    Ningning Di,1,2,* Ning Mao,3,* Wenna Cheng,4 Haopeng Pang,1 Yan Ren,1 Ning Wang,2 Xinjiang Liu,2 Bin Wang5 1Department of Radiology, Affiliated Huashan Hospital of Fudan University, Shanghai, 2Department of Radiology, Binzhou Medical University Affiliated Hospital, Binzhou, 3Department of Radiology, Yantai Yuhangding Hospital, Yantai, 4Department of Pharmacy, Binzhou Medical University Affiliated Hospital, Binzhou, 5Department of Medical Imaging and Nuclear Medicine, Binzhou Medical Universi...

  4. Activity report 1977

    The Research and Development (R and D) activities of the Reactor Research Centre, Kalpakkam, during the year 1977 are reported. The report is presented in the form of individual summaries of R and D activities most of which are connected with the FBTR project. These R and D activities deal with various aspects of the FBTR project such as reactor physics, reactor design, reactor engineering, fabrication, testing and quality assurance of reactor materials and components, reactor chemistry, reactor safety, reprocessing, systems analysis and instrumentation. (M.G.B.)

  5. Activation Force Splines

    Engell-Nørregård, Morten Pol; Erleben, Kenny

    dimensional 2D/3D deformable model. Our activation splines are easy to set up and can be used for physics based animation of deformable models such as snake motion and locomotion of characters. Our approach generalises easily to both 2D and 3D simulations and is applicable in physics based games or animations......We present a method for simulating the active contraction of deformable models, usable for interactive animation of soft deformable objects. We present a novel physical principle as the governing equation for the coupling between the low dimensional 1D activation force model and the higher...... due to its simplicity and very low computational cost....

  6. Active Directory cookbook

    Hunter, Laura

    2008-01-01

    When you need practical hands-on support for Active Directory, the updated edition of this extremely popular Cookbook provides quick solutions to more than 300 common (and uncommon) problems you might encounter when deploying, administering, and automating Microsoft's network directory service. For the third edition, Active Directory expert Laura E. Hunter offers troubleshooting recipes based on valuable input from Windows administrators, in addition to her own experience. You'll find solutions for the Lightweight Directory Access Protocol (LDAP), ADAM (Active Directory Application Mode), m

  7. Inspector measurement verification activities

    e most difficult and complex activity facing a safeguards inspector involves the verification of measurements and the performance of the measurement system. Remeasurement is the key to measurement verification activities. Remeasurerements using the facility's measurement system provide the bulk of the data needed for determining the performance of the measurement system. Remeasurements by reference laboratories are also important for evaluation of the measurement system and determination of systematic errors. The use of these measurement verification activities in conjunction with accepted inventory verification practices provides a better basis for accepting or rejecting an inventory. (U.S.)

  8. Scientific activities 1979

    The scientific activities and achievements of the Nuclear Research Center Democritus for the year 1979 are presented in the form of a list of 78 projects giving title, objectives, commencement year, responsible of each project, developed activities and the pertaining lists of publications. The 15 chapters of this work cover the activities of the main Divisions of the Democritus NRC: Electronics, Biology, Physics, Chemistry, Health Physics, Reactor, Radioisotopes, Environmental Radioactivity, Soil Science, Computer Center, Uranium Exploration, Medical Service, Technological Applications and Training. (T.A.)

  9. 1985. Activity progress report

    The research program of the Laboratory of nuclear and high energy physics (LPNHE) of the Institute of nuclear and particle physics (IN2P3) presents the research activities of its groups: principally, the Delphi group which constructs the outer detector of Delphi at LEP, the neutrino group which studies the neutrino mass, the Hera group whose work is collaboration to the construction of a detector for Hera collisioner; in parallel to these activities, other more little groups continue analysis of activities which are going to be finished: they are the CELLO group, the EHS group, the omega prime group and the nuclear emulsion group

  10. Creative activity and inclusion

    Shemanov A.Yu.

    2013-09-01

    Full Text Available The aim of the article was to analyze the inclusion potential of art creative activity, namely of theatre performance, in people with disabilities. The article provides examples of disagreements in understanding the significance of these art activities for exercising the rights of people with disabilities to contribute to culture and art and some problems arising here. The conclusion is made that theatre art performed by people with disabilities is gradually changing its function: from being a means of self-affirmation to the determination of its specific place in overall theatre process. These changes confirm the inclusion potential of theatre art activity.

  11. Encapsulation of active ingredients

    Soest, van, A.J.; Schijndel, van, AWM Jos; Gotlieb, K.F.

    2002-01-01

    Microspheres having a particle size of 50 nm to 1 nm and a polydispersity of less than 40%, consisting of a chemically cross-linked starch shell containing an active ingredient, are obtained by preparing an oil-in-water emulsion of the active ingredient in a hydrophobic phase and starch or a dispersion of a solid active ingredient and starch in water, incorporating the oil-in-water emulsion or solid dispersion in an outer hydrophobic phase, particles of the oil-in-water emulsion or solid disp...

  12. Encapsulation of active ingredients

    Gotlieb, K.F.; Schijndel, van, AWM Jos; Soest, van, A.J.

    1999-01-01

    Microspheres having a particle size of 50 nm to 1 nm and a polydispersity of less than 40%, consisting of a chemically cross-linked starch shell containing an active ingredient, are obtained by preparing an oil-in-water emulsion of the active ingredient in a hydrophobic phase and starch or a dispersion of a solid active ingredient and starch in water, incorporating the oil-in-water emulsion or solid dispersion in an outer hydrophobic phase, particles of the oil-in-water emulsion or solid disp...

  13. Encapsulation of active ingredients

    Soest, van, A.J.; Schijndel, van, AWM Jos; Gotlieb, K.F.

    2000-01-01

    Microspheres having a particle size of 50 nm to 1 nm and a polydispersity of less than 40%, consisting of a chemically cross-linked starch shell containing an active ingredient, are obtained by preparing an oil-in-water emulsion of the active ingredient in a hydrophobic phase and starch or a dispersion of a solid active ingredient and starch in water, incorporating the oil-in-water emulsion or solid dispersion in an outer hydrophobic phase, particles of the oil-in-water emulsion or solid disp...

  14. Forecast of auroral activity

    A new technique is developed to predict auroral activity based on a sample of over 9000 auroral sites identified in global auroral images obtained by an ultraviolet imager on the NASA Polar satellite during a 6-month period. Four attributes of auroral activity sites are utilized in forecasting, namely, the area, the power, and the rates of change in area and power. This new technique is quite accurate, as indicated by the high true skill scores for forecasting three different levels of auroral dissipation during the activity lifetime. The corresponding advanced warning time ranges from 22 to 79 min from low to high dissipation levels

  15. γ activity in struverite

    The five different struverite samples collected from Southern Thailand were analysed for the 214Pb, 214Bi, 228Ac and 208Tl gamma activities. The concentrations of 226Ra for each of the samples were subsequently deduced from the activities of its daughter nuclides 214Pb and 214Bi on the assumption that secular equilibrium exists between them. Similarly the concentrations of 232Th for each of the samples were also deduced from the activities of its daughter nuclides 228Ac and 208Tl

  16. Physical activation of molecules

    A brief review of processes of physical activation of molecules on the basis of phenomena of electronic and vibrational excitation, electron polarization is presented. Consideration is given to activation by electron impact, photo-, magneto- and mechanoactivation, as well as to radiation activation, proceeding under the effect of high-power radiations (102-107 eV). The character of disturbance of molecules, participating in chemical reactions, under the effect of different types of ionizing radiation (α-particles, electrons, γ-quanta etc.) is discussed

  17. China's Space Activities

    China National Space Administration

    2004-01-01

    @@ Currently, space activities are very active around the world. Space technologies continuously expand to various areas of human activities, and space technology and applications are becoming an indispensable part of modern information society,while the development of space science brings a brand-new view to the development of science and technology. The development of space law is not only an important approach to improving people' s quality of lives, expanding the living space of human being, and exploiting new resources, but also an important symbol of the comprehensive strength and civilization of a nation.

  18. Physics of solar activity

    Sturrock, Peter A.

    1993-01-01

    The aim of the research activity was to increase our understanding of solar activity through data analysis, theoretical analysis, and computer modeling. Because the research subjects were diverse and many researchers were supported by this grant, a select few key areas of research are described in detail. Areas of research include: (1) energy storage and force-free magnetic field; (2) energy release and particle acceleration; (3) radiation by nonthermal electrons; (4) coronal loops; (5) flare classification; (6) longitude distributions of flares; (7) periodicities detected in the solar activity; (8) coronal heating and related problems; and (9) plasma processes.

  19. IPSN's 2001 activity report

    This report summarizes the 2001 activities and operation of the French institute of nuclear protection and safety (IPSN) which has become the institute of radioprotection and nuclear safety (IRSN) after its merging with the office of protection against ionizing radiations (OPRI). IPSN's activities cover: the safety of nuclear facilities, the safety of nuclear wastes, the management of emergencies, the management of sensible materials, the protection of the environment and of the public health, some research activities with foreign partners (central and eastern Europe, Asia..), and a partnership with the GRS, the German homologue of IPSN. (J.S.)

  20. Mnemonic activation by SPECT

    Data of literature show that SPECT is able to detect cerebral activations induced by sensory-motor stimuli. The facts are not clearly established in what concerns the cognitive activations the amplitude of which is lower. We have studied an activation paradigm such as the Grober and Bruschke test which implies the long term explicit memory. It comprises a visual presentation of words followed by their indexed recall. By using a two-day protocol, 2 SPECTs were achieved in 4 healthy right-handed voluntaries as follows: one of activation (A) and one of control (B). The fifth subject benefited by a SPECT B and of an MRI. The injection for the examination A has been done during the indexed recall stage and for the examination B at the moment when the patient repeated several times the same 3 words. The SPECT data were collected 1 hour after the injection of 370 MBq of ECD making use of a 3-head camera equipped with UHR fan collimators and ending by a LMH on the reconstructed images of 8 mm. The MRI has been achieved by means of a Signa 1.5 Tesla magnet. The SPECT A and B of the subjects 1 to 4 were matched elastically to that of the subject 5 and that of the subject 5 was rigidly matched on its MRI. In this way the individual activation cards of the 4 subjects could be averaged and superimposed on the MRI of the 5. subject. One observes an internal temporal activation (maximal activation of left tonsil, +25% and right uncus, +23%) and a right cingulum activation (maximal activation, +25%), in agreement with the neuro-physiological data. The elastic matching makes possible the inter-subject averaging, what increases the signal-to-noise ratio of activation. The inter-modality rigid matching facilitates the anatomical localisation of the activation site. With these adapted tools, the cognitive activation is thus possible by SPECT and opens perspectives for early diagnosis of neurological troubles, namely of Alzheimer's disease

  1. OTI Activity Database

    US Agency for International Development — OTI's worldwide activity database is a simple and effective information system that serves as a program management, tracking, and reporting tool. In each country,...

  2. Active flows on trees

    Forrow, Aden; Dunkel, Jörn

    2016-01-01

    Coherent, large scale dynamics in many nonequilibrium physical, biological, or information transport networks are driven by small-scale local energy input. We introduce and explore a generic model for compressible active flows on tree networks. In contrast to thermally-driven systems, active friction selects discrete states with only a small number of oscillation modes activated at distinct fixed amplitudes. This state selection interacts with graph topology to produce different localized dynamical time scales in separate regions of large networks. Using perturbation theory, we systematically predict the stationary states of noisy networks and find good agreement with a Bayesian state estimation based on a hidden Markov model applied to simulated time series data on binary trees. While the number of stable states per tree scales exponentially with the number of edges, the mean number of activated modes in each state averages $\\sim 1/4$ the number of edges. More broadly, these results suggest that the macrosco...

  3. Facts about Physical Activity

    ... stroke, type 2 diabetes, depression, and some cancers. Physical activity can also help with weight control, and may improve academic achievement in students. There's more . Inactive adults have a ...

  4. Exercise and activity - children

    ... active. Others would rather stay inside and play video games or watch TV. If your child does not ... water sprinkler, or splashing in puddles. Dance to music. Skate, ice-skate, skate-board, or roller-skate. ...

  5. Vessel Activity Record

    National Oceanic and Atmospheric Administration, Department of Commerce — The Vessel Activity Record is a bi-weekly spreadsheet that shows the status of fishing vessels. It records whether fishing vessels are fishing without an observer...

  6. Extravehicular activity technology discipline

    Webbon, Bruce W.

    1990-01-01

    Viewgraphs on extravehicular activity technology discipline for Space Station Freedom are presented. Topics covered include: extravehicular mobility unit; airlock and EMU support equipment; tools, mobility aids, and workstations; and telerobotic work aids interfaces.

  7. Active Fire Mapping Program

    Active Fire Mapping Program Current Large Incidents (Home) New Large Incidents Fire Detection Maps MODIS Satellite Imagery VIIRS Satellite Imagery Fire Detection GIS Data Fire Data in Google Earth ...

  8. Physical Activity and Cancer

    ... of insulin and insulin-like growth factor I (IGF-I), improving the immune response ; and assisting with ... studies have started examining the factors related to long-term behavior change and increases in physical activity. ...

  9. The Active Asteroids

    Jewitt, David; Agarwal, Jessica

    2015-01-01

    Some asteroids eject dust, producing transient, comet-like comae and tails; these are the active asteroids. The causes of activity in this newly-identified population are many and varied. They include impact ejection and disruption, rotational instabilities, electrostatic repulsion, radiation pressure sweeping, dehydration stresses and thermal fracture, in addition to the sublimation of asteroidal ice. These processes were either unsuspected or thought to lie beyond the realm of observation before the discovery of asteroid activity. Scientific interest in the active asteroids lies in their promise to open new avenues into the direct study of asteroid destruction, the production of interplanetary debris, the abundance of asteroid ice and the origin of terrestrial planet volatiles.

  10. Homebuyer Activities Report

    Department of Housing and Urban Development — This monthly report is an Excel spreadsheet. PJs can use this report to view homebuyer activities with the 2012 or 2013 program year in IDIS that are in final draw,...