Comparison of GaP and PH{sub 3} as dopant sources for STM-based device fabrication

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Goh, Kuan Eng Johnson [Australian Research Council Centre of Excellence for Quantum Computer Technology, University of New South Wales, Sydney, New South Wales 2052 (Australia); Oberbeck, L [Australian Research Council Centre of Excellence for Quantum Computer Technology, University of New South Wales, Sydney, New South Wales 2052 (Australia); Butcher, M J [School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); Curson, N J [Australian Research Council Centre of Excellence for Quantum Computer Technology, University of New South Wales, Sydney, New South Wales 2052 (Australia); Ruess, F J [Australian Research Council Centre of Excellence for Quantum Computer Technology, University of New South Wales, Sydney, New South Wales 2052 (Australia); Simmons, M Y [Australian Research Council Centre of Excellence for Quantum Computer Technology, University of New South Wales, Sydney, New South Wales 2052 (Australia)

2007-02-14

We present a comparative study of the use of a GaP solid source as an alternative to gaseous PH{sub 3} for controlled phosphorus {delta}-doping of lithographic patterns on H:Si(001) fabricated by scanning tunnelling microscopy (STM). Whilst our electrical studies show that P {delta}-doping of Si with the GaP solid source and gaseous PH{sub 3} result in essentially the same electrical characteristics, our STM studies reveal that P{sub 2} molecules from the GaP source exhibit a lower selectivity between bare Si(001) and H:Si(001) compared to PH{sub 3} molecules. We discuss the significance of our findings in the context of fabricating nanoscale P dopant devices in Si using STM-based lithography.

[Neuroanatomy of the Parietal Association Areas].

Science.gov (United States)

Kobayashi, Yasushi

2016-11-01

The parietal association cortex comprises the superior and inferior parietal lobules, the precuneus and the cortices in the intraparietal, parietooccipital and lunate sulci. By processing somatic, visual, acoustic and vestibular sensory information, the parietal association cortex plays a pivotal role in spatial cognition and motor control of the eyes and the extremities. Sensory information from the primary and secondary somatosensory areas enters the superior parietal lobule and is transferred to the inferior parietal lobule. Visual information is processed through the dorsal visual pathway and it reaches the inferior parietal lobule, the intraparietal sulcus and the precuneus. Acoustic information is transferred posteriorly from the primary acoustic area, and it reaches the posterior region of the inferior parietal lobule. The areas in the intraparietal sulcus project to the premotor area, the frontal eye fields, and the prefrontal area. These areas are involved in the control of ocular movements, reaching and grasping of the upper extremities, and spatial working memory. The posterior region of the inferior parietal lobule and the precuneus both project either directly, or indirectly via the posterior cingulate gyrus, to the parahippocampal and entorhinal cortices. Both these areas are strongly associated with hippocampal functions for long-term memory formation.

Visual Categorization and the Parietal Cortex

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Jamie K Fitzgerald

2012-05-01

Full Text Available The primate brain is adept at rapidly grouping items and events into functional classes, or categories, in order to recognize the significance of stimuli and guide behavior. Higher cognitive functions have traditionally been considered the domain of frontal areas. However, increasing evidence suggests that parietal cortex is also involved in categorical and associative processes. Previous work showed that the parietal cortex is highly involved in spatial processing, attention and saccadic eye movement planning, and more recent studies have found decision-making signals in LIP. We recently found that a subdivision of parietal cortex, the lateral intraparietal area (LIP, reflects learned categories for multiple types of visual stimuli. Additionally, a comparison of categorization signals in parietal and frontal areas found stronger and earlier categorization signals in parietal cortex, arguing that parietal abstract association or category signals are unlikely to arise via feedback from prefrontal cortex (PFC.

Neuronal oscillations form parietal/frontal networks during contour integration.

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Castellano, Marta; Plöchl, Michael; Vicente, Raul; Pipa, Gordon

2014-01-01

The ability to integrate visual features into a global coherent percept that can be further categorized and manipulated are fundamental abilities of the neural system. While the processing of visual information involves activation of early visual cortices, the recruitment of parietal and frontal cortices has been shown to be crucial for perceptual processes. Yet is it not clear how both cortical and long-range oscillatory activity leads to the integration of visual features into a coherent percept. Here, we will investigate perceptual grouping through the analysis of a contour categorization task, where the local elements that form contour must be linked into a coherent structure, which is then further processed and manipulated to perform the categorization task. The contour formation in our visual stimulus is a dynamic process where, for the first time, visual perception of contours is disentangled from the onset of visual stimulation or from motor preparation, cognitive processes that until now have been behaviorally attached to perceptual processes. Our main finding is that, while local and long-range synchronization at several frequencies seem to be an ongoing phenomena, categorization of a contour could only be predicted through local oscillatory activity within parietal/frontal sources, which in turn, would synchronize at gamma (>30 Hz) frequency. Simultaneously, fronto-parietal beta (13-30 Hz) phase locking forms a network spanning across neural sources that are not category specific. Both long range networks, i.e., the gamma network that is category specific, and the beta network that is not category specific, are functionally distinct but spatially overlapping. Altogether, we show that a critical mechanism underlying contour categorization involves oscillatory activity within parietal/frontal cortices, as well as its synchronization across distal cortical sites.

Multimodal responses induced by cortical stimulation of the parietal lobe: a stereo-electroencephalography study.

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Balestrini, Simona; Francione, Stefano; Mai, Roberto; Castana, Laura; Casaceli, Giuseppe; Marino, Daniela; Provinciali, Leandro; Cardinale, Francesco; Tassi, Laura

2015-09-01

The functional complexity of the parietal lobe still represents a challenge for neurophysiological and functional neuroimaging studies. While the somatosensory functions of the anterior parietal cortex are well established, the posterior parietal cortex has a relevant role in processing the sensory information, including visuo-spatial perception, visual attention, visuo-motor transformations and other complex and not completely understood functions. We retrospectively analysed all the clinical manifestations induced by intracerebral bipolar electrical stimulation in 172 patients suffering from drug-resistant focal epilepsy (mean age 25.6, standard deviation 11.6; 44% females and 56% males) with at least one electrode stereotactically implanted in the parietal cortex. A total of 1186 electrical stimulations were included in the analysis, of which 88 were subsequently excluded because of eliciting pathological electric activity or inducing ictal symptomatology. In the dominant parietal lobe, clinical responses were observed for 56 (25%) of the low-frequency stimulations and for 76 (50%) of the high-frequency stimulations. In the non-dominant parietal lobe, 111 (27%) low-frequency and 176 (55%) high-frequency stimulations were associated with a clinical response. Body scheme alteration was the only clinical effect showing a lateralization, as they were evoked only in the non-dominant hemisphere. The occurrence of somatosensory sensations, motor symptoms, dysarthria and multimodal responses were significantly associated with stimulation of the postcentral gyrus (odds ratio: 5.83, P < 0.001; odds ratio: 8.77, P < 0.001; odds ratio: 5.44, P = 0.011; odds ratio: 8.33, P = 0.006; respectively). Stimulation of the intraparietal sulcus was associated with the occurrence of sensory illusions or hallucinations (odds ratio: 8.68, P < 0.001) and eyeball/eyelid movements or sensations (odds ratio: 4.35, P = 0.047). To our knowledge, this is the only currently available complete

Interleukin-17A Promotes Parietal Cell Atrophy by Inducing ApoptosisSummary

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Kevin A. Bockerstett

Full Text Available Background & Aims: Atrophic gastritis caused by chronic inflammation in the gastric mucosa leads to the loss of gastric glandular cells, including acid-secreting parietal cells. Parietal cell atrophy in a setting of chronic inflammation induces spasmolytic polypeptide expressing metaplasia, a critical step in gastric carcinogenesis. However, the mechanisms by which inflammation causes parietal cell atrophy and spasmolytic polypeptide expressing metaplasia are not well defined. We investigated the role of interleukin-17A (IL-17A in causing parietal cell atrophy. Methods: A mouse model of autoimmune atrophic gastritis was used to examine IL-17A production during early and late stages of disease. Organoids derived from corpus glands were used to determine the direct effects of IL-17A on gastric epithelial cells. Immunofluorescent staining was used to examine IL-17A receptors and the direct effect of signaling on parietal cells. Mice were infected with an IL-17A-producing adenovirus to determine the effects of IL-17A on parietal cells in vivo. Finally, IL-17A neutralizing antibodies were administered to mice with active atrophic gastritis to evaluate the effects on parietal cell atrophy and metaplasia. Results: Increased IL-17A correlated with disease severity in mice with chronic atrophic gastritis. IL-17A caused caspase-dependent gastric organoid degeneration, which could not be rescued with a necroptosis inhibitor. Parietal cells expressed IL-17A receptors and IL-17A treatment induced apoptosis in parietal cells. Overexpressing IL-17A in vivo induced caspase-3 activation and terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling staining in parietal cells. Finally, IL-17A neutralizing antibody decreased parietal cell atrophy and metaplasia in mice with chronic atrophic gastritis. Conclusions: These data identify IL-17A as a cytokine that promotes parietal cell apoptosis during atrophic gastritis, a

Encefalomenigocele atrésico parietal Parietal atresic encephalomeningocele

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Liliana Rivera Oliva

2011-09-01

Full Text Available El encefalocele es una anomalía congénita rara, en la que una porción del encéfalo protruye a través de un orificio craneal (evaginación, generalmente situado en la línea media. Clínicamente se caracteriza por una masa epicraneal, de consistencia blanda, muchas veces acompañada de trastornos psicomotores, convulsiones y trastornos de la visión. Se presenta el caso de un recién nacido con diagnóstico de encefalomeningocele atrésico parietal, intervenido quirúrgicamente y con evolución satisfactoria.The encephalocele is a uncommon congenital anomaly where a portion of encephalon protrudes through a cranial orifice (evagination, generally located in the middle line. Clinically, it is characterized by a soft epicranial mass often accompanied or psychomotor disorders, convulsions and vision disorders. This is the case of a newborn diagnosed with parietal atresic encephalomeningocele operated on with a satisfactory evolution.

Visuo-spatial construction in patients with frontal and parietal lobe lesions

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Himani Kashyap

2011-04-01

Full Text Available Visuospatial construction, traditionally viewed as a putative parietal function, also requires sustained attention, planning, organization strategies and error correction, and hence frontal lobe mediation. The relative contributions of the frontal and parietal lobes are poorly understood. To examine the contributions of parietal, frontal lobes, as well as right and left cerebral hemispheres to visuospatial construction. The Stick Construction Test for two-dimensional construction and the Block Construction Test for three-dimensional construction were administered pre-surgically to patients with lesions in the parietal lobe (n =9 and the frontal lobe (n=11, along with normal control subjects (n =20 matched to the patients on age (+/- 3 years, gender, education (+/- 3 years and handedness. The patients were significantly slower than the controls on both two-dimensional and three-dimensional tests. Patients with parietal lesions were slower than those with frontal lesions on the test of three-dimensional construction. Within each lobe patients with right and left sided lesions did not differ significantly. It appears that tests of three-dimensional construction might be most sensitive to visuospatial construction deficits. Visuospatial construction involves the mediation of both frontal and parietal lobes. The function does not appear to be lateralized. The networks arising from the parieto-occipital areas and projecting to the frontal cortices (e.g., occipito-frontal fasciculus may be the basis of the mediation of both lobes in visuospatial construction. The present findings need replication from studies with larger sample sizes.

Optimized gamma synchronization enhances functional binding of fronto-parietal cortices in mathematically gifted adolescents during deductive reasoning

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Li eZhang

2014-06-01

Full Text Available As enhanced fronto-parietal network has been suggested to support reasoning ability of math-gifted adolescents, the main goal of this EEG source analysis is to investigate the temporal binding of the gamma-band (30-60Hz synchronization between frontal and parietal cortices in adolescents with exceptional mathematical ability, including the functional connectivity of gamma neurocognitive network, the temporal dynamics of fronto-parietal network (phase-locking durations and network lability in time domain, and the self-organized criticality of synchronizing oscillation. Compared with the average-ability subjects, the math-gifted adolescents show a highly integrated fronto-parietal network due to distant gamma phase-locking oscillations, which is indicated by lower modularity of the global network topology, more connector bridges between the frontal and parietal cortices and less connector hubs in the sensorimotor cortex. The time-domain analysis finds that, while maintaining more stable phase dynamics of the fronto-parietal coupling, the math-gifted adolescents are characterized by more extensive fronto-parietal connection reconfiguration. The results from sample fitting in the power-law model further find that the phase-locking durations in the math-gifted brain abides by a wider interval of the power-law distribution. This phase-lock distribution mechanism could represent a relatively optimized pattern for the functional binding of frontal-parietal network, which underlies stable fronto-parietal connectivity and increases flexibility of timely network reconfiguration.

Parietal lesion effects on cued recall following pair associate learning.

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Ben-Zvi, Shir; Soroker, Nachum; Levy, Daniel A

2015-07-01

We investigated the involvement of the posterior parietal cortex in episodic memory in a lesion-effects study of cued recall following pair-associate learning. Groups of patients who had experienced first-incident stroke, generally in middle cerebral artery territory, and exhibited damage that included lateral posterior parietal regions, were tested within an early post-stroke time window. In three experiments, patients and matched healthy comparison groups executed repeated study and cued recall test blocks of pairs of words (Experiment 1), pairs of object pictures (Experiment 2), or pairs of object pictures and environmental sounds (Experiment 3). Patients' brain CT scans were subjected to quantitative analysis of lesion volumes. Behavioral and lesion data were used to compute correlations between area lesion extent and memory deficits, and to conduct voxel-based lesion-symptom mapping. These analyses implicated lateral ventral parietal cortex, especially the angular gyrus, in cued recall deficits, most pronouncedly in the cross-modal picture-sound pairs task, though significant parietal lesion effects were also found in the unimodal word pairs and picture pairs tasks. In contrast to an earlier study in which comparable parietal lesions did not cause deficits in item recognition, these results indicate that lateral posterior parietal areas make a substantive contribution to demanding forms of recollective retrieval as represented by cued recall, especially for complex associative representations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Changes in cerebral activations during movement execution and imagery after parietal cortex TMS interleaved with 3T MRI

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de Vries, Paulien M.; de Jong, Bauke M.; Bohning, Daryl E.; Walker, John A.; George, Mark S.; Leenders, Klaus L.

2009-01-01

The left parietal cortex contributes to goal-directed hand movement. In this study, we targeted this region with transcranial magnetic stimulation (TMS) to assess the effects on a wider distributed circuitry related to motor control. Ten healthy subjects underwent 3 Tesla functional magnetic

Temporal order processing of syllables in the left parietal lobe.

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Moser, Dana; Baker, Julie M; Sanchez, Carmen E; Rorden, Chris; Fridriksson, Julius

2009-10-07

Speech processing requires the temporal parsing of syllable order. Individuals suffering from posterior left hemisphere brain injury often exhibit temporal processing deficits as well as language deficits. Although the right posterior inferior parietal lobe has been implicated in temporal order judgments (TOJs) of visual information, there is limited evidence to support the role of the left inferior parietal lobe (IPL) in processing syllable order. The purpose of this study was to examine whether the left inferior parietal lobe is recruited during temporal order judgments of speech stimuli. Functional magnetic resonance imaging data were collected on 14 normal participants while they completed the following forced-choice tasks: (1) syllable order of multisyllabic pseudowords, (2) syllable identification of single syllables, and (3) gender identification of both multisyllabic and monosyllabic speech stimuli. Results revealed increased neural recruitment in the left inferior parietal lobe when participants made judgments about syllable order compared with both syllable identification and gender identification. These findings suggest that the left inferior parietal lobe plays an important role in processing syllable order and support the hypothesized role of this region as an interface between auditory speech and the articulatory code. Furthermore, a breakdown in this interface may explain some components of the speech deficits observed after posterior damage to the left hemisphere.

Muscarinic responses of gastric parietal cells

International Nuclear Information System (INIS)

Wilkes, J.M.; Kajimura, M.; Scott, D.R.; Hersey, S.J.; Sachs, G.

1991-01-01

Isolated rabbit gastric glands were used to study the nature of the muscarinic cholinergic responses of parietal cells. Carbachol stimulation of acid secretion, as measured by the accumulation of aminopyrine, was inhibited by the M1 antagonist, pirenzepine, with an IC50 of 13 microM; by the M2 antagonist, 11,2-(diethylamino)methyl-1 piperidinyl acetyl-5,11-dihydro-6H-pyrido 2,3-b 1,4 benzodiazepin-6-one (AF-DX 116), with an IC50 of 110 microM; and by the M1/M3 antagonist, diphenyl-acetoxy-4-methylpiperidinemethiodide, with an IC50 of 35 nM. The three antagonists displayed equivalent IC50 values for the inhibition of carbachol-stimulated production of 14CO2 from radiolabeled glucose, which is a measure of the turnover of the H,K-ATPase, the final step of acid secretion. Intracellular calcium levels were measured in gastric glands loaded with FURA 2. Carbachol was shown to both release calcium from an intracellular pool and to promote calcium entry across the plasma membrane. The calcium entry was inhibitable by 20 microM La3+. The relative potency of the three muscarinic antagonists for inhibition of calcium entry was essentially the same as for inhibition of acid secretion or pump related glucose oxidation. Image analysis of the glands showed the effects of carbachol, and of the antagonists, on intracellular calcium were occurring largely in the parietal cell. The rise in cell calcium due to release of calcium from intracellular stores was inhibited by 4-DAMP with an IC50 of 1.7 nM, suggesting that the release pathway was regulated by a low affinity M3 muscarinic receptor or state; Ca entry and acid secretion are regulated by a high affinity M3 muscarinic receptor or state, inhibited by higher 4-DAMP concentrations, suggesting that it is the steady-state elevation of Ca that is related to parietal cell function rather than the [Ca]i transient

Parietal pleural invasion/adhesion of subpleural lung cancer: Quantitative 4-dimensional CT analysis using dynamic-ventilatory scanning

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Sakuma, Kotaro, E-mail: ksakuma@ohara-hp.or.jp [Department of Radiology, Ohara General Hospital, 6-11 Omachi, Fukushima City, Fukushima 960-8611 (Japan); Department of Radiology and Nuclear Medicine, Fukushima Medical University, 1 Hikariga-oka, Fukushima City, Fukushima 960-1295 (Japan); Yamashiro, Tsuneo, E-mail: clatsune@yahoo.co.jp [Department of Radiology, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 903-0215 (Japan); Moriya, Hiroshi, E-mail: hrshmoriya@gmail.com [Department of Radiology, Ohara General Hospital, 6-11 Omachi, Fukushima City, Fukushima 960-8611 (Japan); Murayama, Sadayuki, E-mail: sadayuki@med.u-ryukyu.ac.jp [Department of Radiology, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 903-0215 (Japan); Ito, Hiroshi, E-mail: h-ito@fmu.ac.jp [Department of Radiology and Nuclear Medicine, Fukushima Medical University, 1 Hikariga-oka, Fukushima City, Fukushima 960-1295 (Japan)

2017-02-15

Highlights: • 4DCT can be used for assessment of pleural invasion/adhesion by lung cancer. • Quantitative 4DCT indices of lung cancer and adjacent structures are described. • An automatic analysis of pleural invasion/adhesion would be developed in the future. - Abstract: Purpose: Using 4-dimensional dynamic-ventilatory scanning by a 320-row computed tomography (CT) scanner, we performed a quantitative assessment of parietal pleural invasion and adhesion by peripheral (subpleural) lung cancers. Methods: Sixteen patients with subpleural lung cancer underwent dynamic-ventilation CT during free breathing. Neither parietal pleural invasion nor adhesion was subsequently confirmed by surgery in 10 patients, whereas the other 6 patients were judged to have parietal pleural invasion or adhesion. Using research software, we tracked the movements of the cancer and of an adjacent structure such as the rib or aorta, and converted the data to 3-dimensional loci. The following quantitative indices were compared by the Mann-Whitney test: cross-correlation coefficient between time curves for the distances moved from the inspiratory frame by the cancer and the adjacent structure, the ratio of the total movement distances (cancer/adjacent structure), and the cosine similarities between the inspiratory and expiratory vectors (from the cancer to the adjacent structure) and between vectors of the cancer and of the adjacent structure (from inspiratory to expiratory frames). Results: Generally, the movements of the loci of the lung cancer and the adjacent structure were similar in patients with parietal pleural invasion/adhesion, while they were independent in patients without. There were significant differences in all the parameters between the two patient groups (cross-correlation coefficient and the movement distance ratio, P < 0.01; cosine similarities, P < 0.05). Conclusion: These observations suggest that quantitative indices by dynamic-ventilation CT can be utilized as a

Intellectual disability, muscle weakness and characteristic face in three siblings: A newly described recessive syndrome mapping to 3p24.3-p25.3.

Science.gov (United States)

Kariminejad, Ariana; Nafissi, Shahriar; Nilipoor, Yalda; Tavasoli, Alireza; Van Veldhoven, Paul P; Bonnard, Carine; Ng, Yeng Ting; Majoie, Charles B; Reversade, Bruno; Hennekam, Raoul C

2015-11-01

We report on a sister and two brothers born to healthy Iranian parents with mild intellectual disability, progressive muscle weakness, and characteristic facies. including highly arched eyebrows, down-slanting palpebral fissures, prominent nasal bridge, prominent nose, columella extending below alae nasi, narrow mouth, narrow palate, and dental caries, and in one of them an inability to abduct the left eye. Electrophysiological studies showed signs of myopathy, and muscle biopsies demonstrated only nonspecific signs. Brain MRIs in two of the sibs showed leukencephalopathy with delayed myelination, frontal and parietal hyperintensities, and hippocampal atrophy in one. We have been unable to find a description of this association of features in literature. Based on the occurrence in siblings, no significant difference in phenotype between the brothers and sister, absence of manifestations in parents, and a likely consanguinity between parents we performed a homozygosity mapping. A single identical-by-descent bloc encompassing 57 genes located at 3p24.3-p25.3 was found to segregate within the family with this phenotype. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Sylvian Fissure and Parietal Anatomy in Children with Autism Spectrum Disorder

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Tracey A. Knaus

2012-01-01

Full Text Available Autism spectrum disorder (ASD is characterized by deficits in social functioning and language and communication, with restricted interests or stereotyped behaviors. Anatomical differences have been found in the parietal cortex in children with ASD, but parietal subregions and associations between Sylvian fissure (SF and parietal anatomy have not been explored. In this study, SF length and anterior and posterior parietal volumes were measured on MRI in 30 right-handed boys with ASD and 30 right-handed typically developing boys (7–14 years, matched on age and non-verbal IQ. There was leftward SF and anterior parietal asymmetry, and rightward posterior parietal asymmetry, across groups. There were associations between SF and parietal asymmetries, with slight group differences. Typical SF asymmetry was associated with typical anterior and posterior parietal asymmetry, in both groups. In the atypical SF asymmetry group, controls had atypical parietal asymmetry, whereas in ASD there were more equal numbers of individuals with typical as atypical anterior parietal asymmetry. We did not find significant anatomical-behavioral associations. Our findings of more individuals in the ASD group having a dissociation between cortical asymmetries warrants further investigation of these subgroups and emphasizes the importance of investigating anatomical relationships in addition to group differences in individual regions.

Use of explicit memory cues following parietal lobe lesions.

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Dobbins, Ian G; Jaeger, Antonio; Studer, Bettina; Simons, Jon S

2012-11-01

The putative role of the lateral parietal lobe in episodic memory has recently become a topic of considerable debate, owing primarily to its consistent activation for studied materials during functional magnetic resonance imaging studies of recognition. Here we examined the performance of patients with parietal lobe lesions using an explicit memory cueing task in which probabilistic cues ("Likely Old" or "Likely New"; 75% validity) preceded the majority of verbal recognition memory probes. Without cues, patients and control participants did not differ in accuracy. However, group differences emerged during the "Likely New" cue condition with controls responding more accurately than parietal patients when these cues were valid (preceding new materials) and trending towards less accuracy when these cues were invalid (preceding old materials). Both effects suggest insufficient integration of external cues into memory judgments on the part of the parietal patients whose cued performance largely resembled performance in the complete absence of cues. Comparison of the parietal patients to a patient group with frontal lobe lesions suggested the pattern was specific to parietal and adjacent area lesions. Overall, the data indicate that parietal lobe patients fail to appropriately incorporate external cues of novelty into recognition attributions. This finding supports a role for the lateral parietal lobe in the adaptive biasing of memory judgments through the integration of external cues and internal memory evidence. We outline the importance of such adaptive biasing through consideration of basic signal detection predictions regarding maximum possible accuracy with and without informative environmental cues. Copyright © 2012 Elsevier Ltd. All rights reserved.

Parietal cortex and representation of the mental Self

DEFF Research Database (Denmark)

Lou, Hans C; Luber, Bruce; Crupain, Michael

2004-01-01

For a coherent and meaningful life, conscious self-representation is mandatory. Such explicit "autonoetic consciousness" is thought to emerge by retrieval of memory of personally experienced events ("episodic memory"). During episodic retrieval, functional imaging studies consistently show....... The medial parietal region may, then, be conceived of as a nodal structure in self-representation, functionally connected to both the right parietal and the medial prefrontal cortices. To determine whether medial parietal cortex in this network is essential for episodic memory retrieval with self...

Nuclear Glycogen Inclusions in Canine Parietal Cells.

Science.gov (United States)

Silvestri, S; Lepri, E; Dall'Aglio, C; Marchesi, M C; Vitellozzi, G

2017-05-01

Nuclear glycogen inclusions occur infrequently in pathologic conditions but also in normal human and animal tissues. Their function or significance is unclear. To the best of the authors' knowledge, no reports of nuclear glycogen inclusions in canine parietal cells exist. After initial observations of nuclear inclusions/pseudoinclusions during routine histopathology, the authors retrospectively examined samples of gastric mucosa from dogs presenting with gastrointestinal signs for the presence of intranuclear inclusions/pseudoinclusions and determined their composition using histologic and electron-microscopic methods. In 24 of 108 cases (22%), the authors observed various numbers of intranuclear inclusions/pseudoinclusions within scattered parietal cells. Nuclei were characterized by marked karyomegaly and chromatin margination around a central optically empty or slightly eosinophilic area. The intranuclear inclusions/pseudoinclusions stained positive with periodic acid-Schiff (PAS) and were diastase sensitive, consistent with glycogen. Several PAS-positive/diastase-sensitive sections were further examined by transmission electron microscopy, also using periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) staining to identify polysaccharides. Ultrastructurally, the nuclear inclusions were composed of electron-dense particles that were not membrane bound, without evidence of nuclear membrane invaginations or cytoplasmic organelles in the nuclei, and positive staining with PA-TCH-SP, confirming a glycogen composition. No cytoplasmic glycogen deposits were observed, suggesting that the intranuclear glycogen inclusions were probably synthesized in loco. Nuclear glycogen inclusions were not associated with gastritis or colonization by Helicobacter-like organisms ( P > .05). Our findings suggest that nuclear glycogen inclusions in canine parietal cells could be an incidental finding. Nevertheless, since nuclear glycogen is present in several pathologic

Mice lacking the conserved transcription factor Grainyhead-like 3 (Grhl3) display increased apposition of the frontal and parietal bones during embryonic development.

Science.gov (United States)

Goldie, Stephen J; Arhatari, Benedicta D; Anderson, Peter; Auden, Alana; Partridge, Darren D; Jane, Stephen M; Dworkin, Sebastian

2016-10-18

Increased apposition of the frontal and parietal bones of the skull during embryogenesis may be a risk factor for the subsequent development of premature skull fusion, or craniosynostosis. Human craniosynostosis is a prevalent, and often serious embryological and neonatal pathology. Other than known mutations in a small number of contributing genes, the aetiology of craniosynostosis is largely unknown. Therefore, the identification of novel genes which contribute to normal skull patterning, morphology and premature suture apposition is imperative, in order to fully understand the genetic regulation of cranial development. Using advanced imaging techniques and quantitative measurement, we show that genetic deletion of the highly-conserved transcription factor Grainyhead-like 3 (Grhl3) in mice (Grhl3 -/- ) leads to decreased skull size, aberrant skull morphology and premature apposition of the coronal sutures during embryogenesis. Furthermore, Grhl3 -/- mice also present with premature collagen deposition and osteoblast alignment at the sutures, and the physical interaction between the developing skull, and outermost covering of the brain (the dura mater), as well as the overlying dermis and subcutaneous tissue, appears compromised in embryos lacking Grhl3. Although Grhl3 -/- mice die at birth, we investigated skull morphology and size in adult animals lacking one Grhl3 allele (heterozygous; Grhl3 +/- ), which are viable and fertile. We found that these adult mice also present with a smaller cranial cavity, suggestive of post-natal haploinsufficiency in the context of cranial development. Our findings show that our Grhl3 mice present with increased apposition of the frontal and parietal bones, suggesting that Grhl3 may be involved in the developmental pathogenesis of craniosynostosis.

Xenomelia: a new right parietal lobe syndrome.

Science.gov (United States)

McGeoch, Paul D; Brang, David; Song, Tao; Lee, Roland R; Huang, Mingxiong; Ramachandran, V S

2011-12-01

Damage to the right parietal lobe has long been associated with various disorders of body image. The authors have recently suggested that an unusual behavioural condition in which otherwise rational individuals desire the amputation of a healthy limb might also arise from right parietal dysfunction. Four subjects who desired the amputation of healthy legs (two right, one left and one, at first, bilateral and then left only) were recruited and underwent magnetoencephalography (MEG) scans during tactile stimulation of sites above and below the desired amputation line. Regions of interest (ROIs) in each hemisphere (superior parietal lobule (SPL), inferior parietal lobule, S1, M1, insula, premotor cortex and precuneus) were defined using FreeSurfer software. Analysis of average MEG activity across the 40-140 ms post-stimulation timeframe was carried out using an unpaired t test. This revealed significantly reduced activation only in the right SPL ROI for the subjects' affected legs when compared with both subjects' unaffected legs and that of controls. The right SPL is a cortical area that appears ideally placed to unify disparate sensory inputs to create a coherent sense of having a body. The authors propose that inadequate activation of the right SPL leads to the unnatural situation in which the sufferers can feel the limb in question being touched without it actually incorporating into their body image, with a resulting desire for amputation. The authors introduce the term 'xenomelia' as a more appropriate name than apotemnophilia or body integrity identity disorder, for what appears to be an unrecognised right parietal lobe syndrome.

Reduced parietal activation in cervical dystonia after parietal TMS interleaved with fMRI

NARCIS (Netherlands)

de Vries, Paulien M.; de Jong, Bauke M.; Bohning, Daryl E.; Hinson, Vanessa K.; George, Mark S.; Leenders, Klaus L.

Objective: Clinically normal hand movement with altered cerebral activation patterns in cervical dystonia (CD) may imply cerebral adaptation. Since impaired sensorimotor integration appears to play a role in dystonia, left superior parietal cortex modulation with repetitive transcranial magnetic

Functional segregation and integration within fronto-parietal networks.

Science.gov (United States)

Parlatini, Valeria; Radua, Joaquim; Dell'Acqua, Flavio; Leslie, Anoushka; Simmons, Andy; Murphy, Declan G; Catani, Marco; Thiebaut de Schotten, Michel

2017-02-01

Experimental data on monkeys and functional studies in humans support the existence of a complex fronto-parietal system activating for cognitive and motor tasks, which may be anatomically supported by the superior longitudinal fasciculus (SLF). Advanced tractography methods have recently allowed the separation of the three branches of the SLF but are not suitable for their functional investigation. In order to gather comprehensive information about the functional organisation of these fronto-parietal connections, we used an innovative method, which combined tractography of the SLF in the largest dataset so far (129 participants) with 14 meta-analyses of functional magnetic resonance imaging (fMRI) studies. We found that frontal and parietal functions can be clustered into a dorsal spatial/motor network associated with the SLF I, and a ventral non-spatial/motor network associated with the SLF III. Further, all the investigated functions activated a middle network mostly associated with the SLF II. Our findings suggest that dorsal and ventral fronto-parietal networks are segregated but also share regions of activation, which may support flexible response properties or conscious processing. In sum, our novel combined approach provided novel findings on the functional organisation of fronto-parietal networks, and may be successfully applied to other brain connections. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Motor role of parietal cortex in a monkey model of hemispatial neglect.

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Kubanek, Jan; Li, Jingfeng M; Snyder, Lawrence H

2015-04-21

Parietal cortex is central to spatial cognition. Lesions of parietal cortex often lead to hemispatial neglect, an impairment of choices of targets in space. It has been unclear whether parietal cortex implements target choice at the general cognitive level, or whether parietal cortex subserves the choice of targets of particular actions. To address this question, monkeys engaged in choice tasks in two distinct action contexts--eye movements and arm movements. We placed focused reversible lesions into specific parietal circuits using the GABAA receptor agonist muscimol and validated the lesion placement using MRI. We found that lesions on the lateral bank of the intraparietal sulcus [lateral intraparietal area (LIP)] specifically biased choices made using eye movements, whereas lesions on the medial bank of the intraparietal sulcus [parietal reach region (PRR)] specifically biased choices made using arm movements. This double dissociation suggests that target choice is implemented in dedicated parietal circuits in the context of specific actions. This finding emphasizes a motor role of parietal cortex in spatial choice making and contributes to our understanding of hemispatial neglect.

Preparation and evaluation of various 32P sources for intravascular brachytherapy

International Nuclear Information System (INIS)

Petelenz, B.U.; Bilski, P.; Ochab, E.; Rajchel, B.; Styczen, J.; Walichiewicz, P.; Wodniecki, J.; Wilczek, K.

2001-01-01

A relatively high per cent of restenoses, being a long-term complication of percutaneous transluminal coronary angioplasty (PTCA), can be significantly reduced by short-range ionizing radiation applied locally, immediately after PTCA. In search for dosimetrically favourable and easy to handle radiation sources for this purpose, we tried a pure β - emitter 32 P (t 1/2 =14.3 days). Ways of preparation of 32 P sources were the following: (1) Neutron activation of 31 P layers implanted into metallic surfaces by ionic methods; (2) Conversion coating of metallic surfaces in aqueous solutions containing 32 PO 4 3- ions; (3) Direct application of Na 2 H 32 PO 4 solutions in the angioplasty balloon. It was shown that: (1) 32 P sources obtained by 31 P ion implantation followed by neutron activation can be useful, but only if activation of the support material by thermal neutrons is negligible; (2) Phosphate layers on stainless steel surface exhibit rather poor adhesion. Similar layers on titanium require further studies; (3) Liquid 32 P sources ensure very good radial dose distribution but only utmost care in filling the balloon can give a reliable activity-dose dependence. Dosimetry of liquid sources, performed in a PMMA phantom by thermoluminescence method showed that 32 P sources of radioactive concentration of 200 MBq/cm 3 can deposit therapeutic dose during about 12 min of exposition. TL detectors manufactured for this purpose in our laboratory show very good spatial resolution and can be recommended for similar studies. (author)

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

International Nuclear Information System (INIS)

Zhao Kunyuan; Wang Bin; Long Jinfeng; Li Lixin; Shen Xiaojun

2010-01-01

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)

Intrinsic connections and architectonics of posterior parietal cortex in the rhesus monkey

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Pandya, D.N.; Seltzer, B.

1982-01-01

By means of autoradiographic and ablation-degeneration techniques, the intrinsic cortical connections of the posterior parietal cortex in the rhesus monkey were traced and correlated with a reappraisal of cerebral architectonics. Two major rostral-to-caudal connectional sequences exist. One begins in the dorsal postcentral gyrus (area 2) and proceeds, through architectonic divisions of the superior parietal lobule (areas PE and PEc), to a cortical region on the medial surface of the parietal lobe (area PGm). This area has architectonic features similar to those of the caudal inferior parietal lobule (area PG). The second sequence begins in the ventral post/central gyrus (area 2) and passes through the rostral inferior parietal lobule (areas PG and PFG) to reach the caudal inferior parietal lobule (area PG). Both the superior parietal lobule and the rostral inferior parietal lobule also send projections to various other zones located in the parietal opercular region, the intraparietal sulcus, and the caudalmost portion of the cingulate sulcus. Areas PGm and PG, on the other hand, project to each other, to the cingulate region, to the caudalmost portion of the superior temporal gyrus, and to the upper bank of the superior temporal sulcus. Finally, a reciprocal sequence of connections, directed from caudal to rostral, links together many of the above-mentioned parietal zones. With regard to the laminar pattern of termination, the rostral-to-caudal connections are primarily distributed in the form of cortical ''columns'' while the caudal-to-rostral connections are found mainly over the first cortical cell layer

Kinesthetic alexia due to left parietal lobe lesions.

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Ihori, Nami; Kawamura, Mitsuru; Araki, Shigeo; Kawachi, Juro

2002-01-01

To investigate the neuropsychological mechanisms of kinesthetic alexia, we asked 7 patients who showed kinesthetic alexia with preserved visual reading after damage to the left parietal region to perform tasks consisting of kinesthetic written reproduction (writing down the same letter as the kinesthetic stimulus), kinesthetic reading aloud, visual written reproduction (copying letters), and visual reading aloud of hiragana (Japanese phonograms). We compared the performance in these tasks and the lesion sites in each patient. The results suggested that deficits in any one of the following functions might cause kinesthetic alexia: (1) the retrieval of kinesthetic images (motor engrams) of characters from kinesthetic stimuli, (2) kinesthetic images themselves, (3) access to cross-modal association from kinesthetic images, and (4) cross-modal association itself (retrieval of auditory and visual images from kinesthetic images of characters). Each of these factors seemed to be related to different lesion sites in the left parietal lobe. Copyright 2002 S. Karger AG, Basel

Bilateral, posterior parietal polymicrogyria as part of speech therapy ...

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SA Journal of Radiology ... Magnetic resonance imaging (MRI) has been associated with either diffuse polymicrogyria around the entire extent of the sylvian fissure or in the posterior aspects of the parietal regions, in which case it is called posterior parietal ... This article discusses the possible embryological origin of these

Isolation, culture and adenoviral transduction of parietal cells from mouse gastric mucosa

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Gliddon, Briony L; Nguyen, Nhung V; Gunn, Priscilla A; Gleeson, Paul A; Driel, Ian R van

2008-01-01

Here we describe a method for the isolation of intact gastric glands from mice and primary culture and transfection of mouse gastric epithelial cells. Collagenase digestion of PBS-perfused mouse stomachs released large intact gastric glands that were plated on a basement membrane matrix. The heterogeneous gland cell cultures typically contain ∼60% parietal cells. Isolated mouse parietal cells remain viable in culture for up to 5 days and react strongly with an antibody specific to the gastric H + /K + ATPase. Isolated intact mouse gastric glands and primary cultures of mouse parietal cells respond to the secretagogue, histamine. Typical morphological changes from a resting to an acid-secreting active parietal cell were observed. In resting cultures of mouse parietal cells, the H + /K + ATPase displayed a cytoplasmic punctate staining pattern consistent with tubulovesicle element structures. Following histamine stimulation, an expansion of internal apical vacuole structures was observed together with a pronounced redistribution of the H + /K + ATPase from the cytoplasm to the apical vacuoles. A reproducible procedure to express genes of interest exogenously in these cultures of mouse parietal cells was also established. This method combines recombinant adenoviral transduction with magnetic field-assisted transfection resulting in ∼30% transduced parietal cells. Adenoviral-transduced parietal cells maintain their ability to undergo agonist-induced activation. This protocol will be useful for the isolation, culture and expression of genes in parietal cells from genetically modified mice and as such will be an invaluable tool for studying the complex exocytic and endocytic trafficking events of the H + /K + ATPase which underpin the regulation of acid secretion

Origin of parietal podocytes in atubular glomeruli mapped by lineage tracing.

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Schulte, Kevin; Berger, Katja; Boor, Peter; Jirak, Peggy; Gelman, Irwin H; Arkill, Kenton P; Neal, Christopher R; Kriz, Wilhelm; Floege, Jürgen; Smeets, Bart; Moeller, Marcus J

2014-01-01

Parietal podocytes are fully differentiated podocytes lining Bowman's capsule where normally only parietal epithelial cells (PECs) are found. Parietal podocytes form throughout life and are regularly observed in human biopsies, particularly in atubular glomeruli of diseased kidneys; however, the origin of parietal podocytes is unresolved. To assess the capacity of PECs to transdifferentiate into parietal podocytes, we developed and characterized a novel method for creating atubular glomeruli by electrocoagulation of the renal cortex in mice. Electrocoagulation produced multiple atubular glomeruli containing PECs as well as parietal podocytes that projected from the vascular pole and lined Bowman's capsule. Notably, induction of cell death was evident in some PECs. In contrast, Bowman's capsules of control animals and normal glomeruli of electrocoagulated kidneys rarely contained podocytes. PECs and podocytes were traced by inducible and irreversible genetic tagging using triple transgenic mice (PEC- or Pod-rtTA/LC1/R26R). Examination of serial cryosections indicated that visceral podocytes migrated onto Bowman's capsule via the vascular stalk; direct transdifferentiation from PECs to podocytes was not observed. Similar results were obtained in a unilateral ureter obstruction model and in human diseased kidney biopsies, in which overlap of PEC- or podocyte-specific antibody staining indicative of gradual differentiation did not occur. These results suggest that induction of atubular glomeruli leads to ablation of PECs and subsequent migration of visceral podocytes onto Bowman's capsule, rather than transdifferentiation from PECs to parietal podocytes.

Intradiploic encephalocele of the left parietal bone: A case report

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Kim, Hyung Sock; Huh, Choon Woong; Kim, Dal Soo; Mok, Jin Ho; Kim, In Soo; Yang, Geun Seok [Myongji St. Mary' s Hospital, Seoul (Korea, Republic of)

2015-06-15

Encephaloceles are generally regarded as midline abnormalities. A 50-year-old man presented with a parietal intradiploic encephalocele manifesting as intermittent headache for the past 6 months. Computed tomography (CT) showed bone destruction associated with a left parietal lesion. Magnetic resonance imaging (MRI) demonstrated brain herniation within the intradiploic space. Cerebral angiographic imaging showed a normal cerebral vessel pattern within the herniated brain lesion. In this case, surgical treatment may not be necessary in the absence of concurrent symptoms and neurologic deficit. We report the CT, MRI, and angiographic findings of an extremely rare case of parietal intradiploic encephalocele in adulthood.

Intradiploic encephalocele of the left parietal bone: A case report

International Nuclear Information System (INIS)

Kim, Hyung Sock; Huh, Choon Woong; Kim, Dal Soo; Mok, Jin Ho; Kim, In Soo; Yang, Geun Seok

2015-01-01

Encephaloceles are generally regarded as midline abnormalities. A 50-year-old man presented with a parietal intradiploic encephalocele manifesting as intermittent headache for the past 6 months. Computed tomography (CT) showed bone destruction associated with a left parietal lesion. Magnetic resonance imaging (MRI) demonstrated brain herniation within the intradiploic space. Cerebral angiographic imaging showed a normal cerebral vessel pattern within the herniated brain lesion. In this case, surgical treatment may not be necessary in the absence of concurrent symptoms and neurologic deficit. We report the CT, MRI, and angiographic findings of an extremely rare case of parietal intradiploic encephalocele in adulthood

Syndecan-1 in the mouse parietal peritoneum microcirculation in inflammation.

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Paulina M Kowalewska

Full Text Available BACKGROUND: The heparan sulfate proteoglycan syndecan-1 (CD138 was shown to regulate inflammatory responses by binding chemokines and cytokines and interacting with adhesion molecules, thereby modulating leukocyte trafficking to tissues. The objectives of this study were to examine the expression of syndecan-1 and its role in leukocyte recruitment and chemokine presentation in the microcirculation underlying the parietal peritoneum. METHODS: Wild-type BALB/c and syndecan-1 null mice were stimulated with an intraperitoneal injection of Staphylococcus aureus LTA, Escherichia coli LPS or TNFα and the microcirculation of the parietal peritoneum was examined by intravital microscopy after 4 hours. Fluorescence confocal microscopy was used to examine syndecan-1 expression in the peritoneal microcirculation using fluorescent antibodies. Blocking antibodies to adhesion molecules were used to examine the role of these molecules in leukocyte-endothelial cell interactions in response to LTA. To determine whether syndecan-1 co-localizes with chemokines in vivo, fluorescent antibodies to syndecan-1 were co-injected intravenously with anti-MIP-2 (CXCL2, anti-KC (CXCL1 or anti-MCP-1 (CCL2. RESULTS AND CONCLUSION: Syndecan-1 was localized to the subendothelial region of peritoneal venules and the mesothelial layer. Leukocyte rolling was significantly decreased with LPS treatment while LTA and TNFα significantly increased leukocyte adhesion compared with saline control. Leukocyte-endothelial cell interactions were not different in syndecan-1 null mice. Antibody blockade of β2 integrin (CD18, ICAM-1 (CD54 and VCAM-1 (CD106 did not decrease leukocyte adhesion in response to LTA challenge while blockade of P-selectin (CD62P abrogated leukocyte rolling. Lastly, MIP-2 expression in the peritoneal venules was not dependent on syndecan-1 in vivo. Our data suggest that syndecan-1 is expressed in the parietal peritoneum microvasculature but does not regulate leukocyte

Aspirin induces morphological transformation to the secretory state in isolated rabbit parietal cells.

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Murthy, U K; Levine, R A

1991-08-01

The morphological response of rabbit parietal cells to aspirin was evaluated by grading several ultra-structural features including the extent of the tubulovesicular system, intracellular secretory canaliculi, and microvilli. After exposure of isolated parietal cells and gastric glands to aspirin or histamine, there was an approximately twofold increase in the ratio of secretory to nonsecretory parietal cells, and depletion of extracellular Ca2+ abolished the aspirin-induced morphological changes. Morphometry in parietal cells showed that aspirin induced a sixfold increase in secretory canalicular membrane elaboration. Aspirin potentiated histamine-induced parietal cell respiration and aminopyrine uptake ratio but did not increase basal respiration or aminopyrine uptake, suggesting an apparent dissociation from aspirin-induced morphological changes.

Matrix metalloproteinase-9 expression is enhanced in renal parietal epithelial cells of zucker diabetic Fatty rats and is induced by albumin in in vitro primary parietal cell culture.

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Yuanyuan Zhang

Full Text Available As a subfamily of matrix metalloproteinases (MMPs, gelatinases including MMP-2 and MMP-9 play an important role in remodeling and homeostasis of the extracellular matrix. However, conflicting results have been reported regarding their expression level and activity in the diabetic kidney. This study investigated whether and how MMP-9 expression and activity were changed in glomerular epithelial cells upon albumin overload. In situ zymography, immunostaining and Western blot for renal MMP gelatinolytic activity and MMP-9 protein expression were performed in Zucker lean and Zucker diabetic rats. Confocal microscopy revealed a focal increase in gelatinase activity and MMP-9 protein in the glomeruli of diabetic rats. Increased glomerular MMP-9 staining was mainly observed in hyperplastic parietal epithelial cells (PECs expressing claudin-1 in the diabetic kidneys. Interestingly, increased parietal MMP-9 was often accompanied by decreased staining for podocyte markers (nephrin and podocalyxin in the sclerotic area of affected glomeruli in diabetic rats. Additionally, urinary excretion of podocyte marker proteins was significantly increased in association with the levels of MMP-9 and albumin in the urine of diabetic animals. To evaluate the direct effect of albumin on expression and activity of MMP-9, primary cultured rat glomerular PECs were incubated with rat serum albumin (0.25 - 1 mg/ml for 24 - 48 hrs. MMP-9 mRNA levels were significantly increased following albumin treatment. Meanwhile, albumin administration resulted in a dose-dependent increase in MMP-9 protein and activity in culture supernatants of PECs. Moreover, albumin activated p44/42 mitogen-activated protein kinase (MAPK in PECs. Inhibition of p44/42 MAPK suppressed albumin-induced MMP-9 secretion from glomerular PECs. Taken together, we have demonstrated that an up-regulation of MMP-9 in activated parietal epithelium is associated with a loss of adjacent podocytes in progressive

Matrix Metalloproteinase-9 Expression Is Enhanced in Renal Parietal Epithelial Cells of Zucker Diabetic Fatty Rats and Is Induced by Albumin in In Vitro Primary Parietal Cell Culture

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Zhang, Yuanyuan; George, Jasmine; Li, Yun; Olufade, Rebecca; Zhao, Xueying

2015-01-01

As a subfamily of matrix metalloproteinases (MMPs), gelatinases including MMP-2 and MMP-9 play an important role in remodeling and homeostasis of the extracellular matrix. However, conflicting results have been reported regarding their expression level and activity in the diabetic kidney. This study investigated whether and how MMP-9 expression and activity were changed in glomerular epithelial cells upon albumin overload. In situ zymography, immunostaining and Western blot for renal MMP gelatinolytic activity and MMP-9 protein expression were performed in Zucker lean and Zucker diabetic rats. Confocal microscopy revealed a focal increase in gelatinase activity and MMP-9 protein in the glomeruli of diabetic rats. Increased glomerular MMP-9 staining was mainly observed in hyperplastic parietal epithelial cells (PECs) expressing claudin-1 in the diabetic kidneys. Interestingly, increased parietal MMP-9 was often accompanied by decreased staining for podocyte markers (nephrin and podocalyxin) in the sclerotic area of affected glomeruli in diabetic rats. Additionally, urinary excretion of podocyte marker proteins was significantly increased in association with the levels of MMP-9 and albumin in the urine of diabetic animals. To evaluate the direct effect of albumin on expression and activity of MMP-9, primary cultured rat glomerular PECs were incubated with rat serum albumin (0.25 - 1 mg/ml) for 24 - 48 hrs. MMP-9 mRNA levels were significantly increased following albumin treatment. Meanwhile, albumin administration resulted in a dose-dependent increase in MMP-9 protein and activity in culture supernatants of PECs. Moreover, albumin activated p44/42 mitogen-activated protein kinase (MAPK) in PECs. Inhibition of p44/42 MAPK suppressed albumin-induced MMP-9 secretion from glomerular PECs. Taken together, we have demonstrated that an up-regulation of MMP-9 in activated parietal epithelium is associated with a loss of adjacent podocytes in progressive diabetic nephropathy

Acute parietal lobe infarction presenting as Gerstmann’s syndrome and cognitive decline mimicking senile dementia

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Chen TY

2013-07-01

Full Text Available Tien-Yu Chen,1 Chun-Yen Chen,1,3 Che-Hung Yen,2,3 Shin-Chang Kuo,1,3 Yi-Wei Yeh,1,3 Serena Chang,1 San-Yuan Huang1,31Department of Psychiatry, 2Department of Neurology, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, 3Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of ChinaAbstract: Gerstmann’s syndrome encompasses the tetrad of finger agnosia, agraphia, acalculia, and right-left confusion. An elderly man with a history of several cardiovascular diseases was initially brought to the psychiatric outpatient department by his family because of worsening of recent memory, executive function, and mixed anxious-depressive mood. Gerstmann’s syndrome without obvious motor function impairment and dementia-like features could be observed at first. Emergent brain computed tomography scan revealed new left-middle cerebral artery infarction over the left posterior parietal lobe. This case reminds us that acute cerebral infarction involving the parietal lobe may present as Gerstmann’s syndrome accompanied by cognitive decline mimicking dementia. As a result, emergent organic workups should be arranged, especially for elderly patients at high risk for cerebral vascular accident.Keywords: Gerstmann’s syndrome, dementia, parietal lobe infarction

Clinical evidence of parietal cortex dysfunction and correlation with extent of allodynia in CRPS type 1.

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Cohen, H; McCabe, C; Harris, N; Hall, J; Lewis, J; Blake, D R

2013-04-01

Unusual symptoms such as digit misidentification and neglect-like phenomena have been reported in complex regional pain syndrome (CRPS), which we hypothesized could be explained by parietal lobe dysfunction. Twenty-two patients with chronic CRPS attending an in-patient rehabilitation programme underwent standard neurological examination followed by clinical assessment of parietal lobe function and detailed sensory testing. Fifteen (68%) patients had evidence of parietal lobe dysfunction. Six (27%) subjects failed six or more test categories and demonstrated new clinical signs consistent with their parietal testing impairments, which were impacting significantly on activities of daily living. A higher incidence was noted in subjects with >1 limb involvement, CRPS affecting the dominant side and in left-handed subjects. Eighteen patients (82%) had mechanical allodynia covering 3-57.5% of the body surface area. Allochiria (unilateral tactile stimulation perceived only in the analogous location on the opposite limb), sensory extinction (concurrent bilateral tactile stimulation perceived only in one limb), referred sensations (unilateral tactile stimulation perceived concurrently in another discrete body area) and dysynchiria (unilateral non-noxious tactile stimulation perceived bilaterally as noxious) were present in some patients. Greater extent of body surface allodynia was correlated with worse parietal function (Spearman's rho = -0.674, p = 0.001). In patients with chronic CRPS, detailed clinical examination may reveal parietal dysfunction, with severity relating to the extent of allodynia. © 2012 European Federation of International Association for the Study of Pain Chapters.

Distributed patterns of occipito-parietal functional connectivity predict the precision of visual working memory.

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Galeano Weber, Elena M; Hahn, Tim; Hilger, Kirsten; Fiebach, Christian J

2017-02-01

Limitations in visual working memory (WM) quality (i.e., WM precision) may depend on perceptual and attentional limitations during stimulus encoding, thereby affecting WM capacity. WM encoding relies on the interaction between sensory processing systems and fronto-parietal 'control' regions, and differences in the quality of this interaction are a plausible source of individual differences in WM capacity. Accordingly, we hypothesized that the coupling between perceptual and attentional systems affects the quality of WM encoding. We combined fMRI connectivity analysis with behavioral modeling by fitting a variable precision and fixed capacity model to the performance data obtained while participants performed a visual delayed continuous response WM task. We quantified functional connectivity during WM encoding between occipital and parietal brain regions activated during both perception and WM encoding, as determined using a conjunction of two independent experiments. The multivariate pattern of voxel-wise inter-areal functional connectivity significantly predicted WM performance, most specifically the mean of WM precision but not the individual number of items that could be stored in memory. In particular, higher occipito-parietal connectivity was associated with higher behavioral mean precision. These results are consistent with a network perspective of WM capacity, suggesting that the efficiency of information flow between perceptual and attentional neural systems is a critical determinant of limitations in WM quality. Copyright © 2016 Elsevier Inc. All rights reserved.

Exogenous vs. endogenous attention: Shifting the balance of fronto-parietal activity.

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Meyer, Kristin N; Du, Feng; Parks, Emily; Hopfinger, Joseph B

2018-03-01

Despite behavioral and electrophysiological evidence for dissociations between endogenous (voluntary) and exogenous (reflexive) attention, fMRI results have yet to consistently and clearly differentiate neural activation patterns between these two types of attention. This study specifically aimed to determine whether activity in the dorsal fronto-parietal network differed between endogenous and exogenous conditions. Participants performed a visual discrimination task in endogenous and exogenous attention conditions while undergoing fMRI scanning. Analyses revealed robust and bilateral activation throughout the dorsal fronto-parietal network for each condition, in line with many previous results. In order to investigate possible differences in the balance of neural activity within this network with greater sensitivity, a priori regions of interest (ROIs) were selected for analysis, centered on the frontal eye fields (FEF) and intraparietal sulcus (IPS) regions identified in previous studies. The results revealed a significant interaction between region, condition, and hemisphere. Specifically, in the left hemisphere, frontal areas were more active than parietal areas, but only during endogenous attention. Activity in the right hemisphere, in contrast, remained relatively consistent for these regions across conditions. Analysis of this activity over time indicates that this left-hemispheric regional imbalance is present within the FEF early, at 3-6.5 s post-stimulus presentation, whereas a regional imbalance in the exogenous condition is not evident until 6.5-8 s post-stimulus presentation. Overall, our results provide new evidence that although the dorsal fronto-parietal network is indeed associated with both types of attentional orienting, regions of the network are differentially engaged over time and across hemispheres depending on the type of attention. Copyright © 2018 Elsevier Ltd. All rights reserved.

Right parietal cortex and calculation processing: intraoperative functional mapping of multiplication and addition in patients affected by a brain tumor.

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Della Puppa, Alessandro; De Pellegrin, Serena; d'Avella, Elena; Gioffrè, Giorgio; Munari, Marina; Saladini, Marina; Salillas, Elena; Scienza, Renato; Semenza, Carlo

2013-11-01

The role of parietal areas in number processing is well known. The significance of intraoperative functional mapping of these areas has been only partially explored, however, and only a few discordant data are available in the surgical literature with regard to the right parietal lobe. The purpose of this study was to evaluate the clinical impact of simple calculation in cortical electrostimulation of right-handed patients affected by a right parietal brain tumor. Calculation mapping in awake surgery was performed in 3 right-handed patients affected by high-grade gliomas located in the right parietal lobe. Preoperatively, none of the patients presented with calculation deficits. In all 3 cases, after sensorimotor and language mapping, cortical and intraparietal sulcus areas involved in single-digit multiplication and addition calculations were mapped using bipolar electrostimulation. In all patients, different sites of the right parietal cortex, mainly in the inferior lobule, were detected as being specifically related to calculation (multiplication or addition). In 2 patients the intraparietal sulcus was functionally specific for multiplication. No functional sites for language were detected. All sites functional for calculation were spared during tumor resection, which was complete in all cases without postoperative neurological deficits. These findings provide intraoperative data in support of an anatomofunctional organization for multiplication and addition within the right parietal area. Furthermore, the study shows the potential clinical relevance of intraoperative mapping of calculation in patients undergoing surgery in the right parietal area. Further and larger studies are needed to confirm these data and assess whether mapped areas are effectively essential for function.

MMN and novelty P3 in coma and other altered states of consciousness: a review.

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Morlet, Dominique; Fischer, Catherine

2014-07-01

In recent decades, there has been a growing interest in the assessment of patients in altered states of consciousness. There is a need for accurate and early prediction of awakening and recovery from coma. Neurophysiological assessment of coma was once restricted to brainstem auditory and primary cortex somatosensory evoked potentials elicited in the 30 ms range, which have both shown good predictive value for poor coma outcome only. In this paper, we review how passive auditory oddball paradigms including deviant and novel sounds have proved their efficiency in assessing brain function at a higher level, without requiring the patient's active involvement, thus providing an enhanced tool for the prediction of coma outcome. The presence of an MMN in response to deviant stimuli highlights preserved automatic sensory memory processes. Recorded during coma, MMN has shown high specificity as a predictor of recovery of consciousness. The presence of a novelty P3 in response to the subject's own first name presented as a novel (rare) stimulus has shown a good correlation with coma awakening. There is now a growing interest in the search for markers of consciousness, if there are any, in unresponsive patients (chronic vegetative or minimally conscious states). We discuss the different ERP patterns observed in these patients. The presence of novelty P3, including parietal components and possibly followed by a late parietal positivity, raises the possibility that some awareness processes are at work in these unresponsive patients.

Diffusion Tensor Magnetic Resonance Imaging Finding of Discrepant Fractional Anisotropy Between the Frontal and Parietal Lobes After Whole-Brain Irradiation in Childhood Medulloblastoma Survivors: Reflection of Regional White Matter Radiosensitivity?

International Nuclear Information System (INIS)

Qiu Deqiang; Kwong, Dora; Chan, Godfrey; Leung, Lucullus; Khong, P.-L.

2007-01-01

Purpose: To test the hypothesis that fractional anisotropy (FA) is more severely reduced in white matter of the frontal lobe compared with the parietal lobe after receiving the same whole-brain irradiation dose in a cohort of childhood medulloblastoma survivors. Methods and Materials: Twenty-two medulloblastoma survivors (15 male, mean [± SD] age = 12.1 ± 4.6 years) and the same number of control subjects (15 male, aged 12.0 ± 4.2 years) were recruited for diffusion tensor magnetic resonance imaging scans. Using an automated tissue classification method and the Talairach Daemon atlas, FA values of frontal and parietal lobes receiving the same radiation dose, and the ratio between them were quantified and denoted as FFA, PFA, and FA f/p , respectively. The Mann-Whitney U test was used to test for significant differences of FFA, PFA, and FA f/p between medulloblastoma survivors and control subjects. Results: Frontal lobe and parietal lobe white matter FA were found to be significantly less in medulloblastoma survivors compared with control subjects (frontal p = 0.001, parietal p = 0.026). Moreover, these differences were found to be discrepant, with the frontal lobe having a significantly larger difference in FA compared with the parietal lobe. The FA f/p of control and medulloblastoma survivors was 1.110 and 1.082, respectively (p = 0.029). Conclusion: Discrepant FA changes after the same irradiation dose suggest radiosensitivity of the frontal lobe white matter compared with the parietal lobe. Special efforts to address the potentially vulnerable frontal lobe after treatment with whole-brain radiation may be needed so as to balance disease control and treatment-related morbidity

Characterization of visual percepts evoked by noninvasive stimulation of the human posterior parietal cortex.

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Peter J Fried

Full Text Available Phosphenes are commonly evoked by transcranial magnetic stimulation (TMS to study the functional organization, connectivity, and excitability of the human visual brain. For years, phosphenes have been documented only from stimulating early visual areas (V1-V3 and a handful of specialized visual regions (V4, V5/MT+ in occipital cortex. Recently, phosphenes were reported after applying TMS to a region of posterior parietal cortex involved in the top-down modulation of visuo-spatial processing. In the present study, we systematically characterized parietal phosphenes to determine if they are generated directly by local mechanisms or emerge through indirect activation of other visual areas. Using technology developed in-house to record the subjective features of phosphenes, we found no systematic differences in the size, shape, location, or frame-of-reference of parietal phosphenes when compared to their occipital counterparts. In a second experiment, discrete deactivation by 1 Hz repetitive TMS yielded a double dissociation: phosphene thresholds increased at the deactivated site without producing a corresponding change at the non-deactivated location. Overall, the commonalities of parietal and occipital phosphenes, and our ability to independently modulate their excitability thresholds, lead us to conclude that they share a common neural basis that is separate from either of the stimulated regions.

A parietal biomarker for ADHD liability:As predicted by The Distributed Effects Perspective Model of ADHD

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T. Sigi eHale

2015-05-01

Full Text Available Background: We previously hypothesized that poor task-directed sensory information processing should be indexed by increased weighting of right hemisphere (RH biased attention and visuo-perceptual brain functions during task operations, and have demonstrated this phenotype in ADHD across multiple studies, using multiple methodologies. However, in our recent Distributed Effects Model of ADHD, we surmised that this phenotype is not ADHD specific, but rather more broadly reflective of any circumstance that disrupts the induction and maintenance of an emergent task-directed neural architecture. Under this view, increased weighting of RH biased attention and visuo-perceptual brain functions is expected to generally index neurocognitive sets that are not optimized for task-directed thought and action, and when durable expressed, liability for ADHD. Method: The current study tested this view by examining whether previously identified rightward parietal EEG asymmetry in ADHD was associated with common ADHD characteristics and comorbidities (i.e., ADHD risk factors. Results: Barring one exception (non-right handedness, we found that it was. Rightward parietal asymmetry was associated with carrying the DRD4-7R risk allele, being male, having mood disorder, and having anxiety disorder. However, differences in the specific expression of rightward parietal asymmetry were observed, which are discussed in relation to possible unique mechanisms underlying ADHD liability in different ADHD RFs. Conclusion: Rightward parietal asymmetry appears to be a durable feature of ADHD liability, as predicted by the Distributed Effects Perspective Model of ADHD. Moreover, variability in the expression of this phenotype may shed light on different sources of ADHD liability.

Bilateral front-parietal polymicrogyria accompanied by cobblestone lissencephaly: 3T MR imaging findings of a case

International Nuclear Information System (INIS)

Bozkurt, Y.; Battal, B.; Ozcan, E.; Kocaoglu, M.

2012-01-01

Full text: Background: The cerebral cortex develops in three overlapping stages: cell proliferation, neuronal migration, and cortical organization. Lissencephaly (smooth brain) is a severe malformation of the cerebral cortex that results from impaired neuronal migration. Polymicrogyria is a disorder of late migration or cortical organization, and supposed to reflect a disruption of normal neuronal migration with subsequent disordered cortical organization. A combination of cobblestone lissencephaly and polymicrogyria is very rare in the same patient's brain. Objective: To present clinical and 3T magnetic resonance (MR) imaging findings of a 17-year-old male with bilateral fronto-parietal polimicrogyria accompanied by cobblestone lissencaphaly. Materials and methods: A 17-year-old male who had seizures and involuntary muscular spasm from birth, was referred to our Hospital. The patient was evaluated by a complete history, physical examination, a laboratory work-up, and cranial MR examination for evaluate the central nervous system. Results: A sharp wave paroxysm in the left temporal area was observed in the electroencephalogram (EEG). The neurological examination of our patient was normal. A slight increase have seen in the aspartate aminotransferase (SGOT) levels. The other biochemical tests were found to be normal. Cranial MR imaging showed an irregular nodular cortex with hypomyelination of the white matter at the lateral and posterior part of the right occipital lobe. We also observed the changes compatible with polymicrogyria in a large area of the medial parts of the bilateral temporal and parietal lobes. Conclusion: The role of radiological modalities for diagnosis of cortical formation disorders are very important. MR imaging are fairly useful for evaluation of these anomalies

Distinct Oscillatory Frequencies Underlie Excitability of Human Occipital and Parietal Cortex.

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Samaha, Jason; Gosseries, Olivia; Postle, Bradley R

2017-03-15

Transcranial magnetic stimulation (TMS) of human occipital and posterior parietal cortex can give rise to visual sensations called phosphenes. We used near-threshold TMS with concurrent EEG recordings to measure how oscillatory brain dynamics covary, on single trials, with the perception of phosphenes after occipital and parietal TMS. Prestimulus power and phase, predominantly in the alpha band (8-13 Hz), predicted occipital TMS phosphenes, whereas higher-frequency beta-band (13-20 Hz) power (but not phase) predicted parietal TMS phosphenes. TMS-evoked responses related to phosphene perception were similar across stimulation sites and were characterized by an early (200 ms) posterior negativity and a later (>300 ms) parietal positivity in the time domain and an increase in low-frequency (∼5-7 Hz) power followed by a broadband decrease in alpha/beta power in the time-frequency domain. These correlates of phosphene perception closely resemble known electrophysiological correlates of conscious perception of near-threshold visual stimuli. The regionally differential pattern of prestimulus predictors of phosphene perception suggests that distinct frequencies may reflect cortical excitability in occipital versus posterior parietal cortex, calling into question the broader assumption that the alpha rhythm may serve as a general index of cortical excitability. SIGNIFICANCE STATEMENT Alpha-band oscillations are thought to reflect cortical excitability and are therefore ascribed an important role in gating information transmission across cortex. We probed cortical excitability directly in human occipital and parietal cortex and observed that, whereas alpha-band dynamics indeed reflect excitability of occipital areas, beta-band activity was most predictive of parietal cortex excitability. Differences in the state of cortical excitability predicted perceptual outcomes (phosphenes), which were manifest in both early and late patterns of evoked activity, revealing the time

Examining the role of the temporo-parietal network in memory, imagery, and viewpoint transformations.

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Dhindsa, Kiret; Drobinin, Vladislav; King, John; Hall, Geoffrey B; Burgess, Neil; Becker, Suzanna

2014-01-01

The traditional view of the medial temporal lobe (MTL) focuses on its role in episodic memory. However, some of the underlying functions of the MTL can be ascertained from its wider role in supporting spatial cognition in concert with parietal and prefrontal regions. The MTL is strongly implicated in the formation of enduring allocentric representations (e.g., O'Keefe, 1976; King et al., 2002; Ekstrom et al., 2003). According to our BBB model (Byrne et al., 2007), these representations must interact with head-centered and body-centered representations in posterior parietal cortex via a transformation circuit involving retrosplenial areas. Egocentric sensory representations in parietal areas can then cue the recall of allocentric spatial representations in long-term memory and, conversely, the products of retrieval in MTL can generate mental imagery within a parietal "window." Such imagery is necessarily egocentric and forms part of visuospatial working memory, in which it can be manipulated for the purpose of planning/imagining the future. Recent fMRI evidence (Lambrey et al., 2012; Zhang et al., 2012) supports the BBB model. To further test the model, we had participants learn the locations of objects in a virtual scene and tested their spatial memory under conditions that impose varying demands on the transformation circuit. We analyzed how brain activity correlated with accuracy in judging the direction of an object (1) from visuospatial working memory (we assume transient working memory due to the order of tasks and the absence of change in viewpoint, but long-term memory retrieval is also possible), (2) after a rotation of viewpoint, or (3) after a rotation and translation of viewpoint (judgment of relative direction). We found performance-related activity in both tasks requiring viewpoint rotation (ROT and JRD, i.e., conditions 2 and 3) in the core medial temporal to medial parietal circuit identified by the BBB model. These results are consistent with the

Investigating the Functional Utility of the Left Parietal ERP Old/New Effect: Brain Activity Predicts within But Not between Participant Variance in Episodic Recollection

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Catherine A. MacLeod

2017-12-01

Full Text Available A success story within neuroimaging has been the discovery of distinct neural correlates of episodic retrieval, providing insight into the processes that support memory for past life events. Here we focus on one commonly reported neural correlate, the left parietal old/new effect, a positive going modulation seen in event-related potential (ERP data that is widely considered to index episodic recollection. Substantial evidence links changes in the size of the left parietal effect to changes in remembering, but the precise functional utility of the effect remains unclear. Here, using forced choice recognition of verbal stimuli, we present a novel population level test of the hypothesis that the magnitude of the left parietal effect correlates with memory performance. We recorded ERPs during old/new recognition, source accuracy and Remember/Know/Guess tasks in two large samples of healthy young adults, and successfully replicated existing within participant modulations of the magnitude of the left parietal effect with recollection. Critically, however, both datasets also show that across participants the magnitude of the left parietal effect does not correlate with behavioral measures of memory – including both subjective and objective estimates of recollection. We conclude that in these tasks, and across this healthy young adult population, the generators of the left parietal ERP effect do not index performance as expected. Taken together, these novel findings provide important constraints on the functional interpretation of the left parietal effect, suggesting that between group differences in the magnitude of old/new effects cannot always safely be used to infer differences in recollection.

Short parietal lobe connections of the human and monkey brain

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Catani, Marco; Robertsson, Naianna; Beyh, Ahmad

2017-01-01

projections were reconstructed for both species and results compared to identify similarities or differences in tract anatomy (i.e., trajectories and cortical projections). In addition, post-mortem dissections were performed in a human brain. The largest tract identified in both human and monkey brains...... and angular gyri of the inferior parietal lobule in humans but only to the supramarginal gyrus in the monkey brain. The third tract connects the postcentral gyrus to the anterior region of the superior parietal lobule and is more prominent in monkeys compared to humans. Finally, short U-shaped fibres...... and monkeys with some differences for those areas that have cytoarchitectonically distinct features in humans. The overall pattern of intraparietal connectivity supports the special role of the inferior parietal lobule in cognitive functions characteristic of humans....

Modulation of fronto-parietal connections during the rubber hand illusion

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Karabanov, Anke Ninija; Ritterband-Rosenbaum, Anina; Christensen, Mark Schram

2017-01-01

Accumulating evidence suggests that parieto-frontal connections play a role in adjusting body ownership during the Rubber Hand Illusion (RHI). Using a motor version of the rubber hand illusion paradigm, we applied single-site and dual-site transcranial magnetic stimulation (TMS) to investigate...... and during three RHI conditions: a) agency and ownership, b) agency but no ownership and c) neither agency nor ownership. Parietal-motor communication differed among experimental conditions. The induction of action ownership was associated with an inhibitory parietal-to-motor connectivity, which...... cortico-spinal and parietal-frontal connectivity during perceived rubber hand ownership. Healthy volunteers received a conditioning TMS pulse over left anterior intraparietal sulcus (aIPS) and a test TMS pulse over left primary motor cortex (M1). Motor Evoked Potentials (MEPs) were recorded at rest...

Endoplasmic reticulum stress responses differ in meninges and associated vasculature, striatum, and parietal cortex after a neurotoxic amphetamine exposure.

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Thomas, Monzy; George, Nysia I; Saini, Upasana T; Patterson, Tucker A; Hanig, Joseph P; Bowyer, John F

2010-08-01

Amphetamine (AMPH) is used to treat attention deficit and hyperactivity disorders, but it can produce neurotoxicity and adverse vascular effects at high doses. The endoplasmic reticulum (ER) stress response (ERSR) entails the unfolded protein response, which helps to avoid or minimize ER dysfunction. ERSR is often associated with toxicities resulting from the accumulation of unfolded or misfolded proteins and has been associated with methamphetamine toxicity in the striatum. The present study evaluates the effect of AMPH on several ERSR elements in meninges and associated vasculature (MAV), parietal cortex, and striatum. Adult, male Sprague-Dawley rats were exposed to saline, environmentally induced hyperthermia (EIH) or four consecutive doses of AMPH that produce hyperthermia. Expression changes (mRNA and protein levels) of key ERSR-related genes in MAV, striatum, and parietal cortex at 3 h or 1 day postdosing were monitored. AMPH increased the expression of some ERSR-related genes in all tissues. Atf4 (activating transcription factor 4, an indicator of Perk pathway activation), Hspa5/Grp78 (Glucose regulated protein 78, master regulator of ERSR), Pdia4 (protein disulfide isomerase, protein-folding enzyme), and Nfkb1 (nuclear factor of kappa b, ERSR sensor) mRNA increased significantly in MAV and parietal cortex 3 h after AMPH. In striatum, Atf4 and Hspa5/Grp78 mRNA significantly increased 3 h after AMPH, but Pdia4 and Nfkb11 did not. Thus, AMPH caused a robust activation of the Perk pathway in all tissues, but significant Ire1 pathway activation occurred only after AMPH treatment in the parietal cortex and striatum. Ddit3/Chop, a downstream effector of the ERSR pathway related to the neurotoxicity, was only increased in striatum and parietal cortex. Conversely, Pdia4, an enzyme protective in the ERSR, was only increased in MAV. The overall ERSR manifestation varied significantly between MAV, striatum, and parietal cortex after a neurotoxic exposure to AMPH.

Overlapping Parietal Activity in Memory and Perception: Evidence for the Attention to Memory Model

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Cabeza, Roberto; Mazuz, Yonatan S.; Stokes, Jared; Kragel, James E.; Woldorff, Marty G.; Ciaramelli, Elisa; Olson, Ingrid R.; Moscovitch, Morris

2011-01-01

The specific role of different parietal regions to episodic retrieval is a topic of intense debate. According to the Attention to Memory (AtoM) model, dorsal parietal cortex (DPC) mediates top-down attention processes guided by retrieval goals, whereas ventral parietal cortex (VPC) mediates bottom-up attention processes captured by the retrieval…

Multicenter prospective randomized study comparing the technique of using a bovine pericardium biological prosthesis reinforcement in parietal herniorrhaphy (Tutomesh TUTOGEN) with simple parietal herniorrhaphy, in a potentially contaminated setting.

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Nedelcu, Marius; Verhaeghe, Pierre; Skalli, Mehdi; Champault, Gerard; Barrat, Christophe; Sebbag, Hugues; Reche, Fabian; Passebois, Laurent; Beyrne, Daniel; Gugenheim, Jean; Berdah, Stephane; Bouayed, Amine; Michel Fabre, Jean; Nocca, David

2016-03-01

The use of parietal synthetic prosthetic reinforcement material in potentially contaminated settings is not recommended, as there is a risk that the prosthesis may become infected. Thus, simple parietal herniorrhaphy, is the conventional treatment, even though there is a significant risk that the hernia may recur. Using new biomaterials of animal origin presently appears to offer a new therapeutic solution, but their effectiveness has yet to be demonstrated. The purpose of this multicenter prospective randomized single-blind study was to compare the surgical treatment of inguinal hernia or abdominal incisional hernia by simple parietal herniorrhaphy without prosthetic reinforcement (Group A), with Tutomesh TUTOGEN biological prosthesis reinforcement parietal herniorrhaphy (Group B), in a potentially contaminated setting. We examined early postoperative complications in the first month after the operation, performed an assessment after one year of survival without recurrence and analyzed the quality of life and pain of the patients (using SF-12 health status questionnaire and Visual Analog Pain Scale) at 1, 6, and 12 months, together with an economic impact study. Hundred and thirty four patients were enrolled between January 2009 and October 2010 in 20 French hospitals. The groups were comparable with respect to their enrollment characteristics, their history, types of operative indications and procedures carried out. At one month post-op, the rate of infectious complications (n(A) = 11(18.33%) vs. n(B) = 12(19.05%), p = 0.919) was not significantly different between the two groups. The assessment after one year of survival without recurrence revealed that survival was significantly greater in Group B (Group A recurrence: 10, Group B: 3; p = 0.0475). No difference in the patients' quality of life was demonstrated at 1, 6, or 12 months. However, at the 1 month follow-up, the "perceived health" rating seemed better in the group with Tutomesh (p�

Bilateral fronto-parietal integrity in young chronic cigarette smokers: a diffusion tensor imaging study.

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Yanhui Liao

Full Text Available Cigarette smoking continues to be the leading cause of preventable morbidity and mortality in China and other countries. Previous studies have demonstrated gray matter loss in chronic smokers. However, only a few studies assessed the changes of white matter integrity in this group. Based on those previous reports of alterations in white matter integrity in smokers, the aim of this study was to examine the alteration of white matter integrity in a large, well-matched sample of chronic smokers and non-smokers.Using in vivo diffusion tensor imaging (DTI to measure the differences of whole-brain white matter integrity between 44 chronic smoking subjects (mean age, 28.0±5.6 years and 44 healthy age- and sex-matched comparison non-smoking volunteers (mean age, 26.3±5.8 years. DTI was performed on a 3-Tesla Siemens scanner (Allegra; Siemens Medical System. The data revealed that smokers had higher fractional anisotropy (FA than healthy non-smokers in almost symmetrically bilateral fronto-parietal tracts consisting of a major white matter pathway, the superior longitudinal fasciculus (SLF.We found the almost symmetrically bilateral fronto-parietal whiter matter changes in a relatively large sample of chronic smokers. These findings support the hypothesis that chronic cigarette smoking involves alterations of bilateral fronto-parietal connectivity.

Differentiated parietal connectivity of frontal regions for "what" and "where" memory.

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Rottschy, C; Caspers, S; Roski, C; Reetz, K; Dogan, I; Schulz, J B; Zilles, K; Laird, A R; Fox, P T; Eickhoff, S B

2013-11-01

In a previous meta-analysis across almost 200 neuroimaging experiments, working memory for object location showed significantly stronger convergence on the posterior superior frontal gyrus, whereas working memory for identity showed stronger convergence on the posterior inferior frontal gyrus (dorsal to, but overlapping with Brodmann's area BA 44). As similar locations have been discussed as part of a dorsal frontal-superior parietal reach system and an inferior frontal grasp system, the aim of the present study was to test whether the regions of working-memory related "what" and "where" processing show a similar distinction in parietal connectivity. The regions that were found in the previous meta-analysis were used as seeds for functional connectivity analyses using task-based meta-analytic connectivity modelling and task-independent resting state correlations. While the ventral seed showed significantly stronger connectivity with the bilateral intraparietal sulcus (IPS), the dorsal seed showed stronger connectivity with the bilateral posterior inferior parietal and the medial superior parietal lobule. The observed connections of regions involved in memory for object location and identity thus clearly demonstrate a distinction into separate pathways that resemble the parietal connectivity patterns of the dorsal and ventral premotor cortex in non-human primates and humans. It may hence be speculated that memory for a particular location and reaching towards it as well as object memory and finger positioning for manipulation may rely on shared neural systems. Moreover, the ensuing regions, in turn, featured differential connectivity with the bilateral ventral and dorsal extrastriate cortex, suggesting largely segregated bilateral connectivity pathways from the dorsal visual cortex via the superior and inferior parietal lobules to the dorsal posterior frontal cortex and from the ventral visual cortex via the IPS to the ventral posterior frontal cortex that may

Gastrin receptor characterization: affinity cross-linking of the gastrin receptor on canine gastric parietal cells

International Nuclear Information System (INIS)

Matsumoto, M.; Park, J.; Yamada, T.

1987-01-01

The authors applied affinity cross-linking methods to label the gastrin receptor on isolated canine gastric parietal cells in order to elucidate the nature of its chemical structure. 125 I-labeled Leu 15 -gastrin and 125 I-labeled gastrin/sub 2-17/ bound to intact parietal cells and their membranes with equal affinity, and half-maximal inhibition of binding was obtained at an incubation concentration of 3.2 x 10 -10 M unlabeled gastrin. 125 I-gastrin/sub 2-17/ was cross-linked to plasma membranes or intact parietal cells by incubation in disuccinimidyl suberate. The membrane pellets were solubilized with or without dithiothreitol and applied to electrophoresis on 7.5% sodium dodecyl sulfate polyacrylamide gels. Autoradiograms revealed a band of labeling at M/sub r/ 76,000 and labeling of this band was inhibited in a dose-dependent fashion by addition of unlabeled gastrin to the incubation mixture. Dithiothreitol in concentrations as high as 100 mM did not later the electrophoretic mobility of the labeled band. After taking into account the molecular weight of 125 I-gastrin/sub 2-17/, the results suggest that the gastrin receptor on parietal cells is a single protein of M/sub r/ 74,000 without disulfide-linked subunits

Prediction of Reach Goals in Depth and Direction from the Parietal Cortex

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Matteo Filippini

2018-04-01

Full Text Available Summary: The posterior parietal cortex is well known to mediate sensorimotor transformations during the generation of movement plans, but its ability to control prosthetic limbs in 3D environments has not yet been fully demonstrated. With this aim, we trained monkeys to perform reaches to targets located at various depths and directions and tested whether the reach goal position can be extracted from parietal signals. The reach goal location was reliably decoded with accuracy close to optimal (>90%, and this occurred also well before movement onset. These results, together with recent work showing a reliable decoding of hand grip in the same area, suggest that this is a suitable site to decode the entire prehension action, to be considered in the development of brain-computer interfaces. : Filippini et al. show that it is possible to use parietal cortex activity to predict in which direction the arm will move and how far it will reach. This opens up the possibility of neural prostheses that can accurately guide reach and grasp using signals from this part of the brain. Keywords: neuroprosthetics, offline neural decoding, reaching in depth, monkey, V6A, machine learning, visuomotor transformations, hand guidance, prehension, robotics

Significance of parietal projection in radiosotope scintigraphy of the brain

International Nuclear Information System (INIS)

Fomchenkov, E.P.

1978-01-01

The diagnostic value of the isotope scintigraphy of the brain in the parieal projection with the change of the dip angle of the gamma-chamber detector to the plane of the physiological horizontal was revealed. The observation was made on 100 patients with suspected presence of the volumetric process of the brain. Three variants of placing were studied: the parietal projection - standard (collimator plane parallel to the plane of physiological horizontal and strictly perpendicular to the sagittal plane); the placing with an angle of 30 deg between the detector plane and the physiological horizontal, opened at the front (posterio-parietal); placing with an angle of 30 deg between the detector plane and the physiological horizontal opened at the back (anterio-parietal). A comparative analysis of scintigrams with focal processes of the brain showed the largest informativeness of the proposed modification of the parietal projection in the form of a change of the dip angle of the gamma-chamber detector plane to the plane of the physiological horizontal opened at the back; this makes it possible to reveal more thoroughly the focus of the increased, pathological accumulation of the isotope in different parts of the skull, where the use of as standard placing is of small informativeness

It's how you get there: Walking down a virtual alley activates premotor and parietal areas

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Johanna eWagner

2014-02-01

Full Text Available Voluntary drive is crucial for motor learning, therefore we are interested in the role that motor planning plays in gait movements. In this study we examined the impact of an interactive Virtual Environment (VE feedback task on the EEG patterns during robot assisted walking. We compared walking in the VE modality to two control conditions: walking with a visual attention paradigm, in which visual stimuli were unrelated to the motor task; and walking with mirror feedback, in which participants observed their own movements. Eleven healthy participants were considered. Application of independent component analysis to the EEG revealed three independent component clusters in premotor and parietal areas showing increased activity during walking with the adaptive VE training paradigm compared to the control conditions. During the interactive VE walking task spectral power in frequency ranges 8-12Hz, 15-20Hz and 23-40Hz was significantly (p ≤ 0.05 decreased. This power decrease is interpreted as a correlate of an active cortical area. Furthermore activity in the premotor cortex revealed gait cycle related modulations significantly different (p ≤ 0.05 from baseline in the frequency range 23-40Hz during walking. These modulations were significantly (p ≤ 0.05 reduced depending on gait cycle phases in the interactive VE walking task compared to the control conditions.We demonstrate that premotor and parietal areas show increased activity during walking with the adaptive VE training paradigm, when compared to walking with mirror- and movement unrelated feedback. Previous research has related a premotor-parietal network to motor planning and motor intention. We argue that movement related interactive feedback enhances motor planning and motor intention. We hypothesize that this might improve gait recovery during rehabilitation.

Predicting oculomotor behaviour from correlated populations of posterior parietal neurons.

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Graf, Arnulf B A; Andersen, Richard A

2015-01-23

Oculomotor function critically depends on how signals representing saccade direction and eye position are combined across neurons in the lateral intraparietal (LIP) area of the posterior parietal cortex. Here we show that populations of parietal neurons exhibit correlated variability, and that using these interneuronal correlations yields oculomotor predictions that are more accurate and also less uncertain. The structure of LIP population responses is therefore essential for reliable read-out of oculomotor behaviour.

The structure of the parietal pleura and its relationship to pleural liquid dynamics in sheep.

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Albertine, K H; Wiener-Kronish, J P; Staub, N C

1984-03-01

We studied the parietal pleura of six sheep to obtain information on pleural structure, blood supply, and lymphatic drainage. In the strict sense, the parietal pleura is composed of a single layer of mesothelial cells and a uniform layer of loose, irregular connective tissue (about 23 micron in width) subjacent to the mesothelial cells. The parietal pleural blood vessels are 10-15 micron from the pleural space. Tracer substances put in the pleural space are removed at specific locations. Colloidal carbon and chick red blood cells are cleared by the parietal pleural lymphatics located over the intercostal spaces at the caudal end of the thoracic wall and over the lateral sides of the pericardial sac. In these areas the mesothelial cells have specialized openings, the stomata, that directly communicate with the underlying lymphatic lacunae. Cells and particulate matter in the pleural space are cleared only by the parietal pleural lymphatics. Compared to the visceral pleura, we believe the thinness of the parietal pleura, the closeness of its blood vessels to the pleural space, and its specialized lymphatic clearance pathways, together indicate that the parietal pleura plays a major role in pleural liquid and protein dynamics in sheep.

Testing a novel method for improving wayfinding by means of a P3b Virtual Reality Visual Paradigm in normal aging.

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de Tommaso, Marina; Ricci, Katia; Delussi, Marianna; Montemurno, Anna; Vecchio, Eleonora; Brunetti, Antonio; Bevilacqua, Vitoantonio

2016-01-01

We propose a virtual reality (VR) model, reproducing a house environment, where color modification of target places, obtainable by home automation in a real ambient, was tested by means of a P3b paradigm. The target place (bathroom door) was designed to be recognized during a virtual wayfinding in a realistic reproduction of a house environment. Different color and luminous conditions, easily obtained in the real ambient from a remote home automation control, were applied to the target and standard places, all the doors being illuminated in white (W), and only target doors colored with a green (G) or red (R) spotlight. Three different Virtual Environments (VE) were depicted, as the bathroom was designed in the aisle (A), living room (L) and bedroom (B). EEG was recorded from 57 scalp electrodes in 10 healthy subjects in the 60-80 year age range (O-old group) and 12 normal cases in the 20-30 year age range (Y-young group). In Young group, all the target stimuli determined a significant increase in P3b amplitude on the parietal, occipital and central electrodes compared to frequent stimuli condition, whatever was the color of the target door, while in elderly group the P3b obtained by the green and red colors was significantly different from the frequent stimulus, on the parietal, occipital, and central derivations, while the White stimulus did not evoke a significantly larger P3b with respect to frequent stimulus. The modulation of P3b amplitude, obtained by color and luminance change of target place, suggests that cortical resources, able to compensate the age-related progressive loss of cognitive performance, need to be facilitated even in normal elderly. The event-related responses obtained by virtual reality may be a reliable method to test the environmental feasibility to age-related cognitive changes.

Examining the role of the temporo-parietal network in memory, imagery and viewpoint transformations

Directory of Open Access Journals (Sweden)

Kiret eDhindsa

2014-09-01

Full Text Available The traditional view of the medial temporal lobe (MTL focuses on its role in episodic memory. However, some of the underlying functions of the MTL can be ascertained from its wider role in supporting spatial cognition in concert with parietal and prefrontal regions. The MTL is strongly implicated in the formation of enduring allocentric representations (e.g. O’Keefe (1976; Ekstrom et al. (2003; King et al. (2002. According to our BBB model (Byrne et al. (2007, these representations must interact with head-centered and body-centered representations in posterior parietal cortex via a transformation circuit involving retrosplenial areas. Egocentric sensory representations in parietal areas can then cue the recall of allocentric spatial representations in long-term memory and, conversely, the products of retrieval in MTL can generate mental imagery within a parietal ’window’. Such imagery is necessarily egocentric and forms part of visuospatial working memory, where it can be manipulated for the purpose of planning/imagining the future. Recent fMRI evidence (Lambrey et al. (2012; Zhang et al. (2012 supports the BBB model. To further test the model, we had participants learn the locations of objects in a virtual scene and tested their spatial memory under conditions that impose varying demands on the transformation circuit. We analyzed how brain activity correlated with accuracy in judging the direction of an object 1 from visuospatial working memory (we assume working memory due to the order of tasks and the consistency viewpoint, but long-term memory is also possible, 2 after a rotation of viewpoint, or 3 after a rotation and translation (judgement of relative direction. We found performance-related activity in both tasks requiring viewpoint rotation in the core medial temporal to medial parietal. These results are consistent with the BBB model and shed further light on the mechanisms underlying spatial memory, mental imagery and viewpoint

Abstract Representations of Object-Directed Action in the Left Inferior Parietal Lobule.

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Chen, Quanjing; Garcea, Frank E; Jacobs, Robert A; Mahon, Bradford Z

2018-06-01

Prior neuroimaging and neuropsychological research indicates that the left inferior parietal lobule in the human brain is a critical substrate for representing object manipulation knowledge. In the present functional MRI study we used multivoxel pattern analyses to test whether action similarity among objects can be decoded in the inferior parietal lobule independent of the task applied to objects (identification or pantomime) and stimulus format in which stimuli are presented (pictures or printed words). Participants pantomimed the use of objects, cued by printed words, or identified pictures of objects. Classifiers were trained and tested across task (e.g., training data: pantomime; testing data: identification), stimulus format (e.g., training data: word format; testing format: picture) and specific objects (e.g., training data: scissors vs. corkscrew; testing data: pliers vs. screwdriver). The only brain region in which action relations among objects could be decoded across task, stimulus format and objects was the inferior parietal lobule. By contrast, medial aspects of the ventral surface of the left temporal lobe represented object function, albeit not at the same level of abstractness as actions in the inferior parietal lobule. These results suggest compulsory access to abstract action information in the inferior parietal lobe even when simply identifying objects.

Patterns of morphological integration between parietal and temporal areas in the human skull.

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Bruner, Emiliano; Pereira-Pedro, Ana Sofia; Bastir, Markus

2017-10-01

Modern humans have evolved bulging parietal areas and large, projecting temporal lobes. Both changes, largely due to a longitudinal expansion of these cranial and cerebral elements, were hypothesized to be the result of brain evolution and cognitive variations. Nonetheless, the independence of these two morphological characters has not been evaluated. Because of structural and functional integration among cranial elements, changes in the position of the temporal poles can be a secondary consequence of parietal bulging and reorientation of the head axis. In this study, we use geometric morphometrics to test the correlation between parietal shape and the morphology of the endocranial base in a sample of adult modern humans. Our results suggest that parietal proportions show no correlation with the relative position of the temporal poles within the spatial organization of the endocranial base. The vault and endocranial base are likely to be involved in distinct morphogenetic processes, with scarce or no integration between these two districts. Therefore, the current evidence rejects the hypothesis of reciprocal morphological influences between parietal and temporal morphology, suggesting that evolutionary spatial changes in these two areas may have been independent. However, parietal bulging exerts a visible effect on the rotation of the cranial base, influencing head position and orientation. This change can have had a major relevance in the reorganization of the head functional axis. © 2017 Wiley Periodicals, Inc.

Sex-dependent age modulation of frontostriatal and temporo-parietal activation during cognitive control.

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Christakou, Anastasia; Halari, Rozmin; Smith, Anna B; Ifkovits, Eve; Brammer, Mick; Rubia, Katya

2009-10-15

Developmental functional imaging studies of cognitive control show progressive age-related increase in task-relevant fronto-striatal activation in male development from childhood to adulthood. Little is known, however, about how gender affects this functional development. In this study, we used event related functional magnetic resonance imaging to examine effects of sex, age, and their interaction on brain activation during attentional switching and interference inhibition, in 63 male and female adolescents and adults, aged 13 to 38. Linear age correlations were observed across all subjects in task-specific frontal, striatal and temporo-parietal activation. Gender analysis revealed increased activation in females relative to males in fronto-striatal areas during the Switch task, and laterality effects in the Simon task, with females showing increased left inferior prefrontal and temporal activation, and males showing increased right inferior prefrontal and parietal activation. Increased prefrontal activation clusters in females and increased parietal activation clusters in males furthermore overlapped with clusters that were age-correlated across the whole group, potentially reflecting more mature prefrontal brain activation patterns for females, and more mature parietal activation patterns for males. Gender by age interactions further supported this dissociation, revealing exclusive female-specific age correlations in inferior and medial prefrontal brain regions during both tasks, and exclusive male-specific age correlations in superior parietal (Switch task) and temporal regions (Simon task). These findings show increased recruitment of age-correlated prefrontal activation in females, and of age-correlated parietal activation in males, during tasks of cognitive control. Gender differences in frontal and parietal recruitment may thus be related to gender differences in the neurofunctional maturation of these brain regions.

Dissociation of Subtraction and Multiplication in the Right Parietal Cortex: Evidence from Intraoperative Cortical Electrostimulation

Science.gov (United States)

Yu, Xiaodan; Chen, Chuansheng; Pu, Song; Wu, Chenxing; Li, Yongnian; Jiang, Tao; Zhou, Xinlin

2011-01-01

Previous research has consistently shown that the left parietal cortex is critical for numerical processing, but the role of the right parietal lobe has been much less clear. This study used the intraoperative cortical electrical stimulation approach to investigate neural dissociation in the right parietal cortex for subtraction and…

Ge p-channel tunneling FETs with steep phosphorus profile source junctions

Science.gov (United States)

Takaguchi, Ryotaro; Matsumura, Ryo; Katoh, Takumi; Takenaka, Mitsuru; Takagi, Shinichi

2018-04-01

The solid-phase diffusion processes of three n-type dopants, i.e., phosphorus (P), arsenic (As), and antimony (Sb), from spin-on-glass (SOG) into Ge are compared. We show that P diffusion can realize both the highest impurity concentration (˜7 × 1019 cm-3) and the steepest impurity profile (˜10 nm/dec) among the cases of the three n-type dopants because the diffusion coefficient is strongly dependent on the dopant concentration. As a result, we can conclude that P is the most suitable dopant for the source formation of Ge p-channel TFETs. Using this P diffusion, we fabricate Ge p-channel TFETs with high-P-concentration and steep-P-profile source junctions and demonstrate their operation. A high ON current of ˜1.7 µA/µm is obtained at room temperature. However, the subthreshold swing and ON current/OFF current ratio are degraded by any generation-recombination-related current component. At 150 K, SSmin of ˜108 mV/dec and ON/OFF ratio of ˜3.5 × 105 are obtained.

Asymmetric multisensory interactions of visual and somatosensory responses in a region of the rat parietal cortex.

Directory of Open Access Journals (Sweden)

Michael T Lippert

Full Text Available Perception greatly benefits from integrating multiple sensory cues into a unified percept. To study the neural mechanisms of sensory integration, model systems are required that allow the simultaneous assessment of activity and the use of techniques to affect individual neural processes in behaving animals. While rodents qualify for these requirements, little is known about multisensory integration and areas involved for this purpose in the rodent. Using optical imaging combined with laminar electrophysiological recordings, the rat parietal cortex was identified as an area where visual and somatosensory inputs converge and interact. Our results reveal similar response patterns to visual and somatosensory stimuli at the level of current source density (CSD responses and multi-unit responses within a strip in parietal cortex. Surprisingly, a selective asymmetry was observed in multisensory interactions: when the somatosensory response preceded the visual response, supra-linear summation of CSD was observed, but the reverse stimulus order resulted in sub-linear effects in the CSD. This asymmetry was not present in multi-unit activity however, which showed consistently sub-linear interactions. These interactions were restricted to a specific temporal window, and pharmacological tests revealed significant local intra-cortical contributions to this phenomenon. Our results highlight the rodent parietal cortex as a system to model the neural underpinnings of multisensory processing in behaving animals and at the cellular level.

Attenuating illusory binding with TMS of the right parietal cortex

OpenAIRE

Esterman, Michael; Verstynen, Timothy; Robertson, Lynn C.

2007-01-01

A number of neuroimaging and neuropsychology studies have implicated various regions of parietal cortex as playing a critical role in the binding of color and form into conjunctions. The current study investigates the role of two such regions by examining how parietal transcranial magnetic stimulation (TMS) influences binding errors known as ‘illusory conjunctions.’ Participants made fewer binding errors after 1 Hz rTMS of the right intraparietal sulcus (IPS), while basic perception of featur...

The 3d8-(3d74p + 3p53d9) transitions in Br X: A striking case of configuration interaction

International Nuclear Information System (INIS)

Kleef, T.A.M. van; Uylings, P.H.M.; Ryabtsev, A.N.; Podobedova, L.I.; Joshi, Y.N.

1988-01-01

The spectrum of nine times ionized bromine (Br X) was photographed in the 90-120 A wavelength region on a variety of grazing incidence spectrographs using an open spark and a triggered spark as light sources. The analysis of the 3d 8 -(3d 7 4p + 3p 5 3d 9 ) transitions has resulted in establishing all 9 levels of the 3d 8 configuration, all 12 levels of the 3p 5 3d 9 configuration and 99 out of 110 levels of the 3d 7 4p configuration. The excitation probability of the 3p inner-shell electron increases with nuclear charge and in Br X is comparable with the excitation probability of the optical electrons resulting in a very strong configuration interaction between the 3p 5 3d 9 and 3d 7 4p configurations. Parametric calculations treating these configurations as one super configuration support the analysis. Two hundred and thirty two lines have been classified in this spectrum. (orig.)

Inhibition of partially purified K+/H+-ATPase from guinea-pig isolated and enriched parietal cells by substituted benzimidazoles.

Science.gov (United States)

Beil, W.; Sewing, K. F.

1984-01-01

The cellular and subcellular distributions of adenosinetriphosphatases (ATPases) were examined in guinea-pig gastric mucosal cells. All cell types displayed Mg2+-ATPase and bicarbonate (HCO3-)-stimulated ATPase activity. K+-ATPase was located only in fractions derived from parietal cells. Differential and density-gradient centrifugation of material prepared from parietal cells revealed that K+-ATPase activity was located in a tubulo-vesicular membrane fraction. Enzyme activity was ten fold greater in this fraction than in a crude parietal cell homogenate. The substituted benzimidazoles, omeprazole and picoprazole, inhibited K+-ATPase (IC50 1.8 +/- 0.5 mumol l-1 and 3.1 +/- 0.4 mumol l-1, respectively). Detailed kinetic analysis indicated that these compounds were non-competitive and reversible inhibitors of the enzyme. In contrast cimetidine and verapamil were without effect on the enzyme. The relevance of the inhibition of K+-ATPase to the antisecretory activity of the benzimidazoles, in experimental animals and man, is discussed. PMID:6146367

Investigating the effects of nitrous oxide sedation on frontal-parietal interactions.

Science.gov (United States)

Ryu, Ji-Ho; Kim, Pil-Jong; Kim, Hong-Gee; Koo, Yong-Seo; Shin, Teo Jeon

2017-06-09

Although functional connectivity has received considerable attention in the study of consciousness, few studies have investigated functional connectivity limited to the sedated state where consciousness is maintained but impaired. The aim of the present study was to investigate changes in functional connectivity of the parietal-frontal network resulting from nitrous oxide-induced sedation, and to determine the neural correlates of cognitive impairment during consciousness transition states. Electroencephalography was acquired from healthy adult patients who underwent nitrous oxide inhalation to induce cognitive impairment, and was analyzed using Granger causality (GC). Periods of awake, sedation and recovery for GC between frontal and parietal areas in the delta, theta, alpha, beta, gamma and total frequency bands were obtained. The Friedman test with post-hoc analysis was conducted for GC values of each period for comparison. As a sedated state was induced by nitrous oxide inhalation, power in the low frequency band showed increased activity in frontal regions that was reversed with discontinuation of nitrous oxide. Feedback and feedforward connections analyzed in spectral GC were changed differently in accordance with EEG frequency bands in the sedated state by nitrous oxide administration. Calculated spectral GC of the theta, alpha, and beta frequency regions in the parietal-to-frontal direction was significantly decreased in the sedated state while spectral GC in the reverse direction did not show significant change. Frontal-parietal functional connectivity is significantly affected by nitrous oxide inhalation. Significantly decreased parietal-to-frontal interaction may induce a sedated state. Copyright © 2017 Elsevier B.V. All rights reserved.

The mirror mechanism in the parietal lobe.

Science.gov (United States)

Rizzolatti, Giacomo; Rozzi, Stefano

2018-01-01

The mirror mechanism is a basic mechanism that transforms sensory representations of others' actions into motor representations of the same actions in the brain of the observer. The mirror mechanism plays an important role in understanding actions of others. In the present chapter we discuss first the basic organization of the posterior parietal lobe in the monkey, stressing that it is best characterized as a motor scaffold, on the top of which sensory information is organized. We then describe the location of the mirror mechanism in the posterior parietal cortex of the monkey, and its functional role in areas PFG, and anterior, ventral, and lateral intraparietal areas. We will then present evidence that a similar functional organization is present in humans. We will conclude by discussing the role of the mirror mechanism in the recognition of action performed with tools. Copyright © 2018 Elsevier B.V. All rights reserved.

Attentional Demands Predict Short-Term Memory Load Response in Posterior Parietal Cortex

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Magen, Hagit; Emmanouil, Tatiana-Aloi; McMains, Stephanie A.; Kastner, Sabine; Treisman, Anne

2009-01-01

Limits to the capacity of visual short-term memory (VSTM) indicate a maximum storage of only 3 or 4 items. Recently, it has been suggested that activity in a specific part of the brain, the posterior parietal cortex (PPC), is correlated with behavioral estimates of VSTM capacity and might reflect a capacity-limited store. In three experiments that…

The phenotypes of podocytes and parietal epithelial cells may overlap in diabetic nephropathy.

Science.gov (United States)

Andeen, Nicole K; Nguyen, Tri Q; Steegh, Floor; Hudkins, Kelly L; Najafian, Behzad; Alpers, Charles E

2015-11-01

Reversal of diabetic nephropathy (DN) has been achieved in humans and mice, but only rarely and under special circumstances. As progression of DN is related to podocyte loss, reversal of DN requires restoration of podocytes. Here, we identified and quantified potential glomerular progenitor cells that could be a source for restored podocytes. DN was identified in 31 human renal biopsy cases and separated into morphologically early or advanced lesions. Markers of podocytes (WT-1, p57), parietal epithelial cells (PECs) (claudin-1), and cell proliferation (Ki-67) were identified by immunohistochemistry. Podocyte density was progressively reduced with DN. Cells marking as podocytes (p57) were present infrequently on Bowman's capsule in controls, but significantly increased in histologically early DN. Ki-67-expressing cells were identified on the glomerular tuft and Bowman's capsule in DN, but rarely in controls. Cells marking as PECs were present on the glomerular tuft, particularly in morphologically advanced DN. These findings show evidence of phenotypic plasticity in podocyte and PEC populations and are consistent with studies in the BTBR ob/ob murine model in which reversibility of DN occurs with podocytes potentially regenerating from PEC precursors. Thus, our findings support, but do not prove, that podocytes may regenerate from PEC progenitors in human DN. If so, progression of DN may represent a modifiable net balance between podocyte loss and regeneration.

A compact sup 3 H(p,gamma) sup 4 He 19.8 MeV gamma-ray source for energy calibration at the Sudbury Neutrino Observatory

CERN Document Server

Poon, A W P; Waltham, C E; Browne, M C; Robertson, R G H; Kherani, N P; Mak, H B

2000-01-01

The Sudbury Neutrino Observatory (SNO) is a new 1000-t D sub 2 O Cherenkov solar neutrino detector. A high-energy gamma-ray source is needed to calibrate SNO beyond the sup 8 B solar neutrino endpoint of 15 MeV. This paper describes the design and construction of a source that generates 19.8 MeV gamma rays using the sup 3 H(p,gamma) sup 4 He reaction (''pT''), and demonstrates that the source meets all the physical, operational and lifetime requirements for calibrating SNO. An ion source was built into this unit to generate and to accelerate protons up to 30 keV, and a high-purity scandium tritide target with a scandium-tritium atomic ratio of 1 : 2.0+-0.2 was included. This pT source is the first self-contained, compact, and portable high-energy gamma-ray source (E subgamma>10 MeV). (authors)

The contribution of the human posterior parietal cortex to episodic memory

OpenAIRE

Sestieri, Carlo; Shulman, Gordon L.; Corbetta, Maurizio

2017-01-01

The posterior parietal cortex (PPC) is traditionally associated with attention, perceptual decision making and sensorimotor transformations, but more recent human neuroimaging studies support an additional role in episodic memory retrieval. In this Opinion article, we present a functional–anatomical model of the involvement of the PPC in memory retrieval. Parietal regions involved in perceptual attention and episodic memory are largely segregated and often show a push–pull relationship, poten...

Haptically guided grasping. FMRI shows right-hemisphere parietal stimulus encoding, and bilateral dorso-ventral parietal gradients of object- and action-related processing during grasp execution

Directory of Open Access Journals (Sweden)

Mattia eMarangon

2016-01-01

Full Text Available The neural bases of haptically-guided grasp planning and execution are largely unknown, especially for stimuli having no visual representations. Therefore, we used functional magnetic resonance imaging (fMRI to monitor brain activity during haptic exploration of novel 3D complex objects, subsequent grasp planning, and the execution of the pre-planned grasps. Haptic object exploration, involving extraction of shape, orientation and length of the to-be-grasped targets, was associated with the fronto-parietal, temporo-occipital, and insular cortex activity. Yet, only the anterior divisions of the posterior parietal cortex (PPC of the right hemisphere were significantly more engaged in exploration of complex objects (vs. simple control disks. None of these regions were re-recruited during the planning phase. Even more surprisingly, the left-hemisphere intraparietal, temporal, and occipital areas that were significantly invoked for grasp planning did not show sensitivity to object features. Finally, grasp execution, involving the re-recruitment of the critical right-hemisphere PPC clusters, was also significantly associated with two kinds of bilateral parieto-frontal processes. The first represents transformations of grasp-relevant target features and is linked to the dorso-dorsal (lateral and medial parieto-frontal networks. The second monitors grasp kinematics and belongs to the ventro-dorsal networks. Indeed, signal modulations associated with these distinct functions follow dorso-ventral gradients, with left aIPS showing significant sensitivity to both target features and the characteristics of the required grasp. Thus, our results from the haptic domain are consistent with the notion that the parietal processing for action guidance reflects primarily transformations from object-related to effector-related coding, and these mechanisms are rather independent of sensory input modality.

The Oft-Neglected Role of Parietal EEG Asymmetry and Risk for Major Depressive Disorder

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Stewart, Jennifer L.; Towers, David N.; Coan, James A.; Allen, John J.B.

2010-01-01

Relatively less right parietal activity may reflect reduced arousal and signify risk for major depressive disorder (MDD). Inconsistent findings with parietal electroencephalographic (EEG) asymmetry, however, suggest issues such as anxiety comorbidity and sex differences have yet to be resolved. Resting parietal EEG asymmetry was assessed in 306 individuals (31% male) with (n = 143) and without (n = 163) a DSM-IV diagnosis of lifetime MDD and no comorbid anxiety disorders. Past MDD+ women displayed relatively less right parietal activity than current MDD+ and MDD- women, replicating prior work. Recent caffeine intake, an index of arousal, moderated the relationship between depression and EEG asymmetry for women and men. Findings suggest that sex differences and arousal should be examined in studies of depression and regional brain activity. PMID:20525011

BOT3P - Bologna Transport Analysis Pre-Post-Processors Version 3.0

International Nuclear Information System (INIS)

Orsi, Roberto

2004-01-01

BOT3P is a set of standard FORTRAN 77 language programs developed at the ENEA-Bologna Nuclear Data Centre. BOT3P Version 1.0 was originally conceived to give the users of the DORT and TORT deterministic transport codes some useful diagnostic tools to prepare and to check their input data files. BOT3P Version 3.0 contains some important additions in the input geometrical model description, such as 'rod' and 'hexagonal' geometrical objects, respecting the exact cross-sectional area value and very suitable to describe a reactor lattice in detail. Moreover, it has extended the possibility to produce the geometrical, material distribution, and fixed neutron source data for the deterministic transport codes TWODANT and THREEDANT of the DANTSYS system and for the PARTISN code too, starting from the same input to BOT3P. When users require X-Y-Z TORT/THREEDANT/PARTISN mesh grids to be generated, BOT3P Version 3.0 produces a geometrical input for the MCNP Monte Carlo transport code also, where the MCNP cells correspond to the X-Y-Z bodies created for TORT.BOT3P Version 3.0 lets users specify areas/volumes of the model where the zone/material distribution can be defined not only by a combinatorial geometry but also by an external source, such as one originated from computerized tomography scan data (only for three-dimensional applications) and from one or more external DORT/TORT input files. BOT3P was developed on a DIGITAL UNIX ALPHA 500/333 workstation and successfully used in some complex neutron shielding and criticality benchmarks. It was also tested on Red Hat Linux 7.1 and is designed to run on most UNIX platforms. All BOT3P versions are publicly available from the Organisation for Economic Co-operation and Development/Nuclear Energy Agency Data Bank (NEA-1627, NEA-1678)

Phosphene-guided transcranial magnetic stimulation of occipital but not parietal cortex suppresses stimulus visibility

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Tapia, Evelina; Mazzi, Chiara; Savazzi, Silvia; Beck, Diane M.

2014-01-01

Transcranial magnetic stimulation (TMS) applied over the occipital lobe approximately 100 ms after the onset of a stimulus decreases its visibility if it appears in the location of the phosphene. Because phosphenes can also be elicited by stimulation of the parietal regions, we asked if the same procedure that is used to reduce visibility of stimuli with occipital TMS will lead to decreased stimulus visibility when TMS is applied to parietal regions. TMS was randomly applied at 0 to 130 ms after the onset of the stimulus (SOA) in steps of 10 ms in occipital and parietal regions. Participants responded to the orientation of the line stimulus and rated its visibility. We replicate previous reports of phosphenes from both occipital and parietal TMS. As previously reported, we also observed visual suppression around the classical 100 ms window both in the objective line orientation and subjective visibility responses with occipital TMS. Parietal stimulation, on the other hand, did not consistently reduce stimulus visibility in any time window. PMID:24584900

Parietal cells-new perspectives in glomerular disease

NARCIS (Netherlands)

Miesen, L.; Steenbergen, E.; Smeets, B.

2017-01-01

In normal glomeruli, parietal epithelial cells (PECs) line the inside of Bowman's capsule and form an inconspicuous sheet of flat epithelial cells in continuity with the proximal tubular epithelial cells (PTECs) at the urinary pole and with the podocytes at the vascular pole. PECs, PTECs and

Visual perception is dependent on visuospatial working memory and thus on the posterior parietal cortex.

Science.gov (United States)

Pisella, Laure

2017-06-01

Visual perception involves complex and active processes. We will start by explaining why visual perception is dependent on visuospatial working memory, especially the spatiotemporal integration of the perceived elements through the ocular exploration of visual scenes. Then we will present neuropsychology, transcranial magnetic stimulation and neuroimaging data yielding information on the specific role of the posterior parietal cortex of the right hemisphere in visuospatial working memory. Within the posterior parietal cortex, neuropsychology data also suggest that there might be dissociated neural substrates for deployment of attention (superior parietal lobules) and spatiotemporal integration (right inferior parietal lobule). Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Evolution of posterior parietal cortex and parietal-frontal networks for specific actions in primates.

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Kaas, Jon H; Stepniewska, Iwona

2016-02-15

Posterior parietal cortex (PPC) is an extensive region of the human brain that develops relatively late and is proportionally large compared with that of monkeys and prosimian primates. Our ongoing comparative studies have led to several conclusions about the evolution of this posterior parietal region. In early placental mammals, PPC likely was a small multisensory region much like PPC of extant rodents and tree shrews. In early primates, PPC likely resembled that of prosimian galagos, in which caudal PPC (PPCc) is visual and rostral PPC (PPCr) has eight or more multisensory domains where electrical stimulation evokes different complex motor behaviors, including reaching, hand-to-mouth, looking, protecting the face or body, and grasping. These evoked behaviors depend on connections with functionally matched domains in premotor cortex (PMC) and motor cortex (M1). Domains in each region compete with each other, and a serial arrangement of domains allows different factors to influence motor outcomes successively. Similar arrangements of domains have been retained in New and Old World monkeys, and humans appear to have at least some of these domains. The great expansion and prolonged development of PPC in humans suggest the addition of functionally distinct territories. We propose that, across primates, PMC and M1 domains are second and third levels in a number of parallel, interacting networks for mediating and selecting one type of action over others. © 2015 Wiley Periodicals, Inc.

Counteracting fatigue in multiple sclerosis with right parietal anodal transcranial direct current stimulation

Directory of Open Access Journals (Sweden)

Katrin Hanken

2016-09-01

Full Text Available Background: Fatigue in multiple sclerosis (MS patients appears to correlate with vigilance decrement as reflected in an increase in reaction time and errors with prolonged time-on-task. Objectives: The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. Methods: In study I, a randomized double-blind placebo-controlled study, anodal tDCS (1,5mA was delivered to the right parietal cortex or the right frontal cortex of 52 healthy participants during the first 20min of a 40min lasting visual vigilance task. Study II, also a randomized double-blind placebo-controlled study, investigated the effect of anodal tDCS (1.5mA over the right parietal cortex in 46 MS patients experiencing cognitive fatigue. TDCS was delivered for 20min before patients performed a 20min lasting visual vigilance task.Results: Study I showed that right parietal stimulation, but not right frontal stimulation, counteracts the increase in reaction time associated with vigilance decrement. Hence, only right parietal stimulation was applied to the MS patients in study II. Stimulation had a significant effect on vigilance decrement in mildly to moderately cognitively fatigued MS patients. Vigilance testing significantly increased the feeling of fatigue independent of stimulation.Conclusions: Anodal tDCS over the right parietal cortex can counteract the increase in reaction times during vigilance performance but not the increase in subjective fatigue. This finding is compatible with our model of fatigue in MS, suggesting a dissociation between the feeling and the behavioral characteristics of fatigue.

Counteracting Fatigue in Multiple Sclerosis with Right Parietal Anodal Transcranial Direct Current Stimulation.

Science.gov (United States)

Hanken, Katrin; Bosse, Mona; Möhrke, Kim; Eling, Paul; Kastrup, Andreas; Antal, Andrea; Hildebrandt, Helmut

2016-01-01

Fatigue in multiple sclerosis (MS) patients appears to correlate with vigilance decrement as reflected in an increase in reaction time (RT) and errors with prolonged time-on-task. The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS) over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. In study I, a randomized double-blind placebo-controlled study, anodal tDCS (1.5 mA) was delivered to the right parietal cortex or the right frontal cortex of 52 healthy participants during the first 20 min of a 40-min lasting visual vigilance task. Study II, also a randomized double-blind placebo-controlled study, investigated the effect of anodal tDCS (1.5 mA) over the right parietal cortex in 46 MS patients experiencing cognitive fatigue. tDCS was delivered for 20 min before patients performed a 20-min lasting visual vigilance task. Study I showed that right parietal stimulation, but not right frontal stimulation, counteracts the increase in RT associated with vigilance decrement. Hence, only right parietal stimulation was applied to the MS patients in study II. Stimulation had a significant effect on vigilance decrement in mildly to moderately cognitively fatigued MS patients. Vigilance testing significantly increased the feeling of fatigue independent of stimulation. Anodal tDCS over the right parietal cortex can counteract the increase in RTs during vigilance performance, but not the increase in subjective fatigue. This finding is compatible with our model of fatigue in MS, suggesting a dissociation between the feeling and the behavioral characteristics of fatigue.

Haptically Guided Grasping. fMRI Shows Right-Hemisphere Parietal Stimulus Encoding, and Bilateral Dorso-Ventral Parietal Gradients of Object- and Action-Related Processing during Grasp Execution.

Science.gov (United States)

Marangon, Mattia; Kubiak, Agnieszka; Króliczak, Gregory

2015-01-01

The neural bases of haptically-guided grasp planning and execution are largely unknown, especially for stimuli having no visual representations. Therefore, we used functional magnetic resonance imaging (fMRI) to monitor brain activity during haptic exploration of novel 3D complex objects, subsequent grasp planning, and the execution of the pre-planned grasps. Haptic object exploration, involving extraction of shape, orientation, and length of the to-be-grasped targets, was associated with the fronto-parietal, temporo-occipital, and insular cortex activity. Yet, only the anterior divisions of the posterior parietal cortex (PPC) of the right hemisphere were significantly more engaged in exploration of complex objects (vs. simple control disks). None of these regions were re-recruited during the planning phase. Even more surprisingly, the left-hemisphere intraparietal, temporal, and occipital areas that were significantly invoked for grasp planning did not show sensitivity to object features. Finally, grasp execution, involving the re-recruitment of the critical right-hemisphere PPC clusters, was also significantly associated with two kinds of bilateral parieto-frontal processes. The first represents transformations of grasp-relevant target features and is linked to the dorso-dorsal (lateral and medial) parieto-frontal networks. The second monitors grasp kinematics and belongs to the ventro-dorsal networks. Indeed, signal modulations associated with these distinct functions follow dorso-ventral gradients, with left aIPS showing significant sensitivity to both target features and the characteristics of the required grasp. Thus, our results from the haptic domain are consistent with the notion that the parietal processing for action guidance reflects primarily transformations from object-related to effector-related coding, and these mechanisms are rather independent of sensory input modality.

The analysis of the 3d8, 3d74p and 3p53d9 configurations of Se IX

International Nuclear Information System (INIS)

Kleef, T.A.M. van; Uylings, P.; Joshi, Y.N.; Podobedova, L.I.; Ryabtsev, A.N.

1984-01-01

The ninth spectrum of selenium (Se IX) was photographed in the region 100-140 A on a variety of grazing incidence spectrographs using a triggered spark or an open spark as sources. On the basis of these measurements all levels of the 3d 8 configuration, 11 out of 12 levels of the 3p 5 3d 9 configuration and 95 out of 110 levels of the 3d 7 4p configuration have been established. A strong configuration interaction exists between the two odd configurations. Least-squares-fit and Hartree-Fock parameter calculations support the analysis. Two hundred and twenty-five (225) lines have been classified in Se IX. (orig.)

Visual Short-Term Memory Activity in Parietal Lobe Reflects Cognitive Processes beyond Attentional Selection.

Science.gov (United States)

Sheremata, Summer L; Somers, David C; Shomstein, Sarah

2018-02-07

Visual short-term memory (VSTM) and attention are distinct yet interrelated processes. While both require selection of information across the visual field, memory additionally requires the maintenance of information across time and distraction. VSTM recruits areas within human (male and female) dorsal and ventral parietal cortex that are also implicated in spatial selection; therefore, it is important to determine whether overlapping activation might reflect shared attentional demands. Here, identical stimuli and controlled sustained attention across both tasks were used to ask whether fMRI signal amplitude, functional connectivity, and contralateral visual field bias reflect memory-specific task demands. While attention and VSTM activated similar cortical areas, BOLD amplitude and functional connectivity in parietal cortex differentiated the two tasks. Relative to attention, VSTM increased BOLD amplitude in dorsal parietal cortex and decreased BOLD amplitude in the angular gyrus. Additionally, the tasks differentially modulated parietal functional connectivity. Contrasting VSTM and attention, intraparietal sulcus (IPS) 1-2 were more strongly connected with anterior frontoparietal areas and more weakly connected with posterior regions. This divergence between tasks demonstrates that parietal activation reflects memory-specific functions and consequently modulates functional connectivity across the cortex. In contrast, both tasks demonstrated hemispheric asymmetries for spatial processing, exhibiting a stronger contralateral visual field bias in the left versus the right hemisphere across tasks, suggesting that asymmetries are characteristic of a shared selection process in IPS. These results demonstrate that parietal activity and patterns of functional connectivity distinguish VSTM from more general attention processes, establishing a central role of the parietal cortex in maintaining visual information. SIGNIFICANCE STATEMENT Visual short-term memory (VSTM) and

Differential frontal-parietal phase synchrony during hypnosis as a function of hypnotic suggestibility.

Science.gov (United States)

Terhune, Devin Blair; Cardeña, Etzel; Lindgren, Magnus

2011-10-01

Spontaneous dissociative alterations in awareness and perception among highly suggestible individuals following a hypnotic induction may result from disruptions in the functional coordination of the frontal-parietal network. We recorded EEG and self-reported state dissociation in control and hypnosis conditions in two sessions with low and highly suggestible participants. Highly suggestible participants reliably experienced greater state dissociation and exhibited lower frontal-parietal phase synchrony in the alpha2 frequency band during hypnosis than low suggestible participants. These findings suggest that highly suggestible individuals exhibit a disruption of the frontal-parietal network that is only observable following a hypnotic induction. Copyright © 2011 Society for Psychophysiological Research.

The inferior parietal lobule and recognition memory : expectancy violation or successful retrieval?

OpenAIRE

O'Connor, Akira R.; Han, Sanghoon; Dobbins, Ian G.

2010-01-01

Functional neuroimaging studies of episodic recognition demonstrate an increased lateral parietal response for studied versus new materials, often termed a retrieval success effect. Using a novel memory analog of attentional cueing, we manipulated the correspondence between anticipated and actual recognition evidence by presenting valid or invalid anticipatory cues (e. g., "likely old") before recognition judgments. Although a superior parietal region demonstrated the retrieval success patter...

Changes of cerebral current source by audiovisual erotic stimuli in premature ejaculation patients.

Science.gov (United States)

Hyun, Jae-Seog; Kam, Sung-Chul; Kwon, Oh-Young

2008-06-01

Premature ejaculation (PE) is one of the most common forms of male sexual dysfunction. The mechanisms of PE remain poorly understood, despite its high prevalence. To investigate the pathophysiology and causes of PE in the central nervous system, we tried to observe the changes in brain current source distribution by audiovisual induction of sexual arousal. Electroencephalograpies were recorded in patients with PE (45.0 +/- 10.3 years old, N = 18) and in controls (45.6 +/- 9.8 years old, N = 18) during four 10-minute segments of resting, watching a music video excerpt, resting, and watching an erotic video excerpt. Five artifact-free 5-second segments were used to obtain cross-spectral low-resolution brain electromagnetic tomography (LORETA) images. Statistical nonparametric maps (SnPM) were obtained to detect the current density changes of six frequency bands between the erotic video session and the music video session in each group. Comparisons were also made between the two groups in the erotic video session. In the SnPM of each spectrum in patients with PE, the current source density of the alpha band was significantly reduced in the right precentral gyrus, the right insula, and both superior parietal lobules (P erotic video session, the current densities of the beta-2 and -3 bands in the PE group were significantly decreased in the right parahippocampal gyrus and left middle temporal gyrus (P < 0.01). Neuronal activity in the right precental gyrus, the right insula, both the superior parietal lobule, the right parahippocampal gyrus, and the left middle temporal gyrus may be decreased in PE patients upon sexual arousal. Further studies are needed to evaluate the meaning of decreased neuronal activities in PE patients.

Early Left Parietal Activity Elicited by Direct Gaze: A High-Density EEG Study

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Burra, Nicolas; Kerzel, Dirk; George, Nathalie

2016-01-01

Gaze is one of the most important cues for human communication and social interaction. In particular, gaze contact is the most primary form of social contact and it is thought to capture attention. A very early-differentiated brain response to direct versus averted gaze has been hypothesized. Here, we used high-density electroencephalography to test this hypothesis. Topographical analysis allowed us to uncover a very early topographic modulation (40–80 ms) of event-related responses to faces with direct as compared to averted gaze. This modulation was obtained only in the condition where intact broadband faces–as opposed to high-pass or low-pas filtered faces–were presented. Source estimation indicated that this early modulation involved the posterior parietal region, encompassing the left precuneus and inferior parietal lobule. This supports the idea that it reflected an early orienting response to direct versus averted gaze. Accordingly, in a follow-up behavioural experiment, we found faster response times to the direct gaze than to the averted gaze broadband faces. In addition, classical evoked potential analysis showed that the N170 peak amplitude was larger for averted gaze than for direct gaze. Taken together, these results suggest that direct gaze may be detected at a very early processing stage, involving a parallel route to the ventral occipito-temporal route of face perceptual analysis. PMID:27880776

Parietal epithelial cells and podocytes in glomerular diseases

NARCIS (Netherlands)

Smeets, B.; Moeller, M.J.

2012-01-01

In recent years, it has become apparent that parietal epithelial cells (PECs) play an important role within the renal glomerulus, in particular in diseased conditions. In this review, we examine current knowledge about the role of PECs and their interactions with podocytes in development and under

Enhanced Working Memory Binding by Direct Electrical Stimulation of the Parietal Cortex

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Agustina Birba

2017-06-01

Full Text Available Recent works evince the critical role of visual short-term memory (STM binding deficits as a clinical and preclinical marker of Alzheimer’s disease (AD. These studies suggest a potential role of posterior brain regions in both the neurocognitive deficits of Alzheimer’s patients and STM binding in general. Thereupon, we surmised that stimulation of the posterior parietal cortex (PPC might be a successful approach to tackle working memory deficits in this condition, especially at early stages. To date, no causal evidence exists of the role of the parietal cortex in STM binding. A unique approach to assess this issue is afforded by single-subject direct intracranial electrical stimulation of specific brain regions during a relevant cognitive task. Electrical stimulation has been used both for clinical purposes and to causally probe brain mechanisms. Previous evidence of electrical currents spreading through white matter along well defined functional circuits indicates that visual working memory mechanisms are subserved by a specific widely distributed network. Here, we stimulated the parietal cortex of a subject with intracranial electrodes as he performed the visual STM task. We compared the ensuing results to those from a non-stimulated condition and to the performance of a matched control group. In brief, direct stimulation of the parietal cortex induced a selective improvement in STM. These results, together with previous studies, provide very preliminary but promising ground to examine behavioral changes upon parietal stimulation in AD. We discuss our results regarding: (a the usefulness of the task to target prodromal stages of AD; (b the role of a posterior network in STM binding and in AD; and (c the potential opportunity to improve STM binding through brain stimulation.

Fronto-parietal coding of goal-directed actions performed by artificial agents.

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Kupferberg, Aleksandra; Iacoboni, Marco; Flanagin, Virginia; Huber, Markus; Kasparbauer, Anna; Baumgartner, Thomas; Hasler, Gregor; Schmidt, Florian; Borst, Christoph; Glasauer, Stefan

2018-03-01

With advances in technology, artificial agents such as humanoid robots will soon become a part of our daily lives. For safe and intuitive collaboration, it is important to understand the goals behind their motor actions. In humans, this process is mediated by changes in activity in fronto-parietal brain areas. The extent to which these areas are activated when observing artificial agents indicates the naturalness and easiness of interaction. Previous studies indicated that fronto-parietal activity does not depend on whether the agent is human or artificial. However, it is unknown whether this activity is modulated by observing grasping (self-related action) and pointing actions (other-related action) performed by an artificial agent depending on the action goal. Therefore, we designed an experiment in which subjects observed human and artificial agents perform pointing and grasping actions aimed at two different object categories suggesting different goals. We found a signal increase in the bilateral inferior parietal lobule and the premotor cortex when tool versus food items were pointed to or grasped by both agents, probably reflecting the association of hand actions with the functional use of tools. Our results show that goal attribution engages the fronto-parietal network not only for observing a human but also a robotic agent for both self-related and social actions. The debriefing after the experiment has shown that actions of human-like artificial agents can be perceived as being goal-directed. Therefore, humans will be able to interact with service robots intuitively in various domains such as education, healthcare, public service, and entertainment. © 2017 Wiley Periodicals, Inc.

The contribution of the human posterior parietal cortex to episodic memory.

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Sestieri, Carlo; Shulman, Gordon L; Corbetta, Maurizio

2017-02-17

The posterior parietal cortex (PPC) is traditionally associated with attention, perceptual decision making and sensorimotor transformations, but more recent human neuroimaging studies support an additional role in episodic memory retrieval. In this Opinion article, we present a functional-anatomical model of the involvement of the PPC in memory retrieval. Parietal regions involved in perceptual attention and episodic memory are largely segregated and often show a push-pull relationship, potentially mediated by prefrontal regions. Moreover, different PPC regions carry out specific functions during retrieval - for example, representing retrieved information, recoding this information based on task demands, or accumulating evidence for memory decisions.

The role of parietal cortex in the formation of colour and motion based concepts

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Samuel William Cheadle

2014-07-01

Full Text Available Imaging evidence shows that separate subdivisions of parietal cortex, in and around the intraparietal sulcus (IPS, are engaged when stimuli are grouped according to colour and to motion (Zeki and Stutters 2013. Since grouping is an essential step in the formation of concepts, we wanted to learn whether parietal cortex is also engaged in the formation of concepts according to these two attributes. Using functional magnetic resonance imaging (fMRI, and choosing the recognition of concept-based colour or motion stimuli as our paradigm, we found that there was strong concept-related activity in and around the intraparietal sulcus (IPS, a region whose homologue in the macaque monkey is known to receive direct but segregated anatomical inputs from V4 and V5. Parietal activity related to colour concepts was juxtaposed but did not overlap with activity related to motion concepts, thus emphasizing the continuation of the segregation of colour and motion into the conceptual system. Concurrent retinotopic mapping experiments showed that within the parietal cortex, concept-related activity increases within later stage IPS areas.

Rat glomerular epithelial cells in culture. Parietal or visceral epithelial origin

International Nuclear Information System (INIS)

Norgaard, J.O.

1987-01-01

Isolated glomeruli from rats were explanted under standard culture conditions and outgrowths were studied by light and electron microscopy in order to identify the cells. Rat glomerular samples contained 20 to 30% structurally well-preserved encapsulated glomeruli which had a large rate of attachment to the substrate and very constantly gave rise to cellular outgrowth. In order to label cells from which outgrowth originated the glomerular incorporation of [ 3 H]thymidine was studied in the preattachment phase. By light and electron microscope autoradiograph it was demonstrated that label was located only over visceral and parietal epithelial cells during the first 3 days of culture. Incorporation of [ 3 H]thymidine was seen in mesangial cells after 5 days, i.e., after the glomeruli had attached to the culture vessels and the initial outgrowth had appeared. Consequently the first cells to grow out were of epithelial origin. Glomeruli were then incubated with [ 3 H]thymidine for the first 2 1/2 days of culture in order to label the epithelial cells, then were allowed to attach to the substrate and induce cell outgrowth. By light microscope autoradiography performed with the outgrowths in situ two types of cells with labeled nuclei were seen: (a) a small, polyhedral ciliated cell which grew in colonies where the cells were joined by junctional complexes (type I), and (b) a second very large, often multinucleated cell (type II). Based on the structural resemblance with their counterparts in situ and on comparisons with positively identified visceral epithelial cells in outgrowths from other species it is suggested that type I cells are derived from the parietal epithelium of Bowman's capsule and type II cells from the visceral epithelium

Investigation of Parietal Polysaccharides from Retama raetam Roots ...

African Journals Online (AJOL)

These results indicate the presence of the homogalacturonans and rhamnogalacturonans in pectin. This study constitutes the preliminary data obtained in the biochemical analysis of the parietal compounds of the roots of a species which grows in an arid area in comparison with those of its aerial parts. Keywords: Retama ...

Fractionation of parietal function in bistable perception probed with concurrent TMS-EEG.

Science.gov (United States)

Schauer, Georg; Chang, Acer; Schwartzman, David; Rae, Charlotte L; Iriye, Heather; Seth, Anil K; Kanai, Ryota

2016-08-16

When visual input has conflicting interpretations, conscious perception can alternate spontaneously between these possible interpretations. This is called bistable perception. Previous neuroimaging studies have indicated the involvement of two right parietal areas in resolving perceptual ambiguity (ant-SPLr and post-SPLr). Transcranial magnetic stimulation (TMS) studies that selectively interfered with the normal function of these regions suggest that they play opposing roles in this type of perceptual switch. In the present study, we investigated this fractionation of parietal function by use of combined TMS with electroencephalography (EEG). Specifically, while participants viewed either a bistable stimulus, a replay stimulus, or resting-state fixation, we applied single pulse TMS to either location independently while simultaneously recording EEG. Combined with participant's individual structural magnetic resonance imaging (MRI) scans, this dataset allows for complex analyses of the effect of TMS on neural time series data, which may further elucidate the causal role of the parietal cortex in ambiguous perception.

Parietal seeding of unsuspected gallbladder carcinoma after laparoscopic cholecystectomy.

Science.gov (United States)

Marmorale, C; Scibé, R; Siquini, W; Massa, M; Brunelli, A; Landi, E

1998-01-01

Laparoscopic cholecystectomy (VALC) represents the treatment of choice for the symptomatic gallstones. However the occurrence of an adenocarcinoma of the gallbladder results a controindication for this surgical technique. We present a case of a 52 years old woman who underwent a VALC; histology revealed a gallbladder adenocarcinoma. For this reason the patient underwent a second operation that is right hepatic trisegmentectomy. Six months later the patient presented with a parietal recurrence at the extraction site of the gallbladder. We discuss the possible mechanism responsible for carcinomatous dissemination during laparoscopic surgery and we raccommend the use of some procedures in order to limit the risk and eventually to treat a neoplastic parietal seeding. These complications suggest the problem about the utility and the future played by video assisted laparoscopic surgery in the diagnosis and treatment of intraabdominal malignancies.

Neuronal synchronization in human parietal cortex during saccade planning

NARCIS (Netherlands)

Werf, J. van der; Buchholz, V.N.; Jensen, O.; Medendorp, W.P.

2009-01-01

Neuropsychological and neuroimaging studies have implicated the human posterior parietal cortex (PPC) in sensorimotor integration and saccade planning However, the temporal dynamics of the underlying physiology and its relationship to observations in non-human primates have been difficult to pin

The Neuroanatomical Basis for Posterior Superior Parietal Lobule Control Lateralization of visuospatial Attention

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Yan eWu

2016-03-01

Full Text Available The right hemispheric dominance in visuospatial attention in human brain has been well established. Converging evidence has documented that ventral posterior parietal cortex (PPC plays an important role in visuospatial attention. The role of dorsal PPC subregions, especially the superior parietal lobule (SPL in visuospatial attention is still controversial. In the current study, we used repetitive transcranial magnetic stimulation (rTMS and diffusion magnetic resonance imaging (MRI techniques to test the role of posterior SPL in visuospatial attention and to investigate the potential neuroanatomical basis for right hemisphere dominance in visuospatial function. TMS results unraveled that the right SPL predominantly mediated visuospatial attention compared to left SPL. Anatomical connections analyses between the posterior SPL and the intrahemispheric frontal subregions and the contralateral PPC revealed that right posterior SPL has stronger anatomical connections with the ipsilateral middle frontal gyrus, with the ipsilateral inferior frontal gyrus, and with contralateral PPC than that of the left posterior SPL. Furthermore, these asymmetric anatomical connections were closely related to behavioral performances. Our findings indicate that SPL plays a crucial role in regulating visuospatial attention, and dominance of visuospatial attention results from unbalanced interactions between the bilateral fronto-parietal networks and the interhemispheric parietal network.

Earthquake source scaling and self-similarity estimation from stacking P and S spectra

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Prieto, GermáN. A.; Shearer, Peter M.; Vernon, Frank L.; Kilb, Debi

2004-08-01

We study the scaling relationships of source parameters and the self-similarity of earthquake spectra by analyzing a cluster of over 400 small earthquakes (ML = 0.5 to 3.4) recorded by the Anza seismic network in southern California. We compute P, S, and preevent noise spectra from each seismogram using a multitaper technique and approximate source and receiver terms by iteratively stacking the spectra. To estimate scaling relationships, we average the spectra in size bins based on their relative moment. We correct for attenuation by using the smallest moment bin as an empirical Green's function (EGF) for the stacked spectra in the larger moment bins. The shapes of the log spectra agree within their estimated uncertainties after shifting along the ω-3 line expected for self-similarity of the source spectra. We also estimate corner frequencies and radiated energy from the relative source spectra using a simple source model. The ratio between radiated seismic energy and seismic moment (proportional to apparent stress) is nearly constant with increasing moment over the magnitude range of our EGF-corrected data (ML = 1.8 to 3.4). Corner frequencies vary inversely as the cube root of moment, as expected from the observed self-similarity in the spectra. The ratio between P and S corner frequencies is observed to be 1.6 ± 0.2. We obtain values for absolute moment and energy by calibrating our results to local magnitudes for these earthquakes. This yields a S to P energy ratio of 9 ± 1.5 and a value of apparent stress of about 1 MPa.

Differential Recruitment of Parietal Cortex during Spatial and Non-spatial Reach Planning

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Pierre-Michel Bernier

2017-05-01

Full Text Available The planning of goal-directed arm reaching movements is associated with activity in the dorsal parieto-frontal cortex, within which multiple regions subserve the integration of arm- and target-related sensory signals to encode a motor goal. Surprisingly, many of these regions show sustained activity during reach preparation even when target location is not specified, i.e., when a motor goal cannot be unambiguously formed. The functional role of these non-spatial preparatory signals remains unresolved. Here this process was investigated in humans by comparing reach preparatory activity in the presence or absence of information regarding upcoming target location. In order to isolate the processes specific to reaching and to control for visuospatial attentional factors, the reaching task was contrasted to a finger movement task. Functional MRI and electroencephalography (EEG were used to characterize the spatio-temporal pattern of reach-related activity in the parieto-frontal cortex. Reach planning with advance knowledge of target location induced robust blood oxygenated level dependent and EEG responses across parietal and premotor regions contralateral to the reaching arm. In contrast, reach preparation without knowledge of target location was associated with a significant BOLD response bilaterally in the parietal cortex. Furthermore, EEG alpha- and beta-band activity was restricted to parietal scalp sites, the magnitude of the latter being correlated with reach reaction times. These results suggest an intermediate stage of sensorimotor transformations in bilateral parietal cortex when target location is not specified.

Prefrontal, posterior parietal and sensorimotor network activity underlying speed control during walking

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Thomas C Bulea

2015-05-01

Full Text Available Accumulating evidence suggests cortical circuits may contribute to control of human locomotion. Here, noninvasive electroencephalography (EEG recorded from able-bodied volunteers during a novel treadmill walking paradigm was used to assess neural correlates of walking. A systematic processing method, including a recently developed subspace reconstruction algorithm, reduced movement-related EEG artifact prior to independent component analysis and dipole source localization. We quantified cortical activity while participants tracked slow and fast target speeds across two treadmill conditions: an active mode that adjusted belt speed based on user movements and a passive mode reflecting a typical treadmill. Our results reveal frequency specific, multi-focal task related changes in cortical oscillations elicited by active walking. Low γ band power, localized to the prefrontal and posterior parietal cortices, was significantly increased during double support and early swing phases, critical points in the gait cycle since the active controller adjusted speed based on pelvis position and swing foot velocity. These phasic γ band synchronizations provide evidence that prefrontal and posterior parietal networks, previously implicated in visuo-spatial and somotosensory integration, are engaged to enhance lower limb control during gait. Sustained μ and β band desynchronization within sensorimotor cortex, a neural correlate for movement, was observed during walking thereby validating our methods for isolating cortical activity. Our results also demonstrate the utility of EEG recorded during locomotion for probing the multi-regional cortical networks which underpin its execution. For example, the cortical network engagement elicited by the active treadmill suggests that it may enhance neuroplasticity for more effective motor training.

Bilateral parietal extradural metastatic ewing's sarcoma simulating acute epidural hematoma

International Nuclear Information System (INIS)

Aslam, E.; Imran, M.; Faridi, N.M.

2006-01-01

Sarcomas usually metastasize to lugs. The following case report describes an unusual metastasis of Ewing's sarcoma to extradural parietal region bilaterally. The primary was found at lower end of ulna. (author)

Does shape discrimination by the mouth activate the parietal and occipital lobes? - near-infrared spectroscopy study.

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Tomonori Kagawa

Full Text Available A cross-modal association between somatosensory tactile sensation and parietal and occipital activities during Braille reading was initially discovered in tests with blind subjects, with sighted and blindfolded healthy subjects used as controls. However, the neural background of oral stereognosis remains unclear. In the present study, we investigated whether the parietal and occipital cortices are activated during shape discrimination by the mouth using functional near-infrared spectroscopy (fNIRS. Following presentation of the test piece shape, a sham discrimination trial without the test pieces induced posterior parietal lobe (BA7, extrastriate cortex (BA18, BA19, and striate cortex (BA17 activation as compared with the rest session, while shape discrimination of the test pieces markedly activated those areas as compared with the rest session. Furthermore, shape discrimination of the test pieces specifically activated the posterior parietal cortex (precuneus/BA7, extrastriate cortex (BA18, 19, and striate cortex (BA17, as compared with sham sessions without a test piece. We concluded that oral tactile sensation is recognized through tactile/visual cross-modal substrates in the parietal and occipital cortices during shape discrimination by the mouth.

Gyri of the human parietal lobe: Volumes, spatial extents, automatic labelling, and probabilistic atlases.

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Heather M Wild

Full Text Available Accurately describing the anatomy of individual brains enables interlaboratory communication of functional and developmental studies and is crucial for possible surgical interventions. The human parietal lobe participates in multimodal sensory integration including language processing and also contains the primary somatosensory area. We describe detailed protocols to subdivide the parietal lobe, analyze morphological and volumetric characteristics, and create probabilistic atlases in MNI152 stereotaxic space. The parietal lobe was manually delineated on 3D T1 MR images of 30 healthy subjects and divided into four regions: supramarginal gyrus (SMG, angular gyrus (AG, superior parietal lobe (supPL and postcentral gyrus (postCG. There was the expected correlation of male gender with larger brain and intracranial volume. We examined a wide range of anatomical features of the gyri and the sulci separating them. At least a rudimentary primary intermediate sulcus of Jensen (PISJ separating SMG and AG was identified in nearly all (59/60 hemispheres. Presence of additional gyri in SMG and AG was related to sulcal features and volumetric characteristics. The parietal lobe was slightly (2% larger on the left, driven by leftward asymmetries of the postCG and SMG. Intersubject variability was highest for SMG and AG, and lowest for postCG. Overall the morphological characteristics tended to be symmetrical, and volumes also tended to covary between hemispheres. This may reflect developmental as well as maturation factors. To assess the accuracy with which the labels can be used to segment newly acquired (unlabelled T1-weighted brain images, we applied multi-atlas label propagation software (MAPER in a leave-one-out experiment and compared the resulting automatic labels with the manually prepared ones. The results showed strong agreement (mean Jaccard index 0.69, corresponding to a mean Dice index of 0.82, average mean volume error of 0.6%. Stereotaxic

Posterior parietal cortex role in a sensorimotor task performance Papel do córtex parietal posterior na realização de uma tarefa sensório-motora

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Sergio Nader

2008-06-01

Full Text Available This study aimed to elucidate electrophysiological and cortical mechanisms involved in anticipatory actions when individuals had to catch balls in free drop; specifically through quantitative electroencephalography (qEEG alpha absolute power changes. The sample was composed for 23 health subjects, both sexes, with ages varying between 25 and 40 years, absence of mental and physical illness, right handed and don't make use of any psychoactive or psychotropic substance at the time of the study. The experiment consisted of a task of catching balls in free drop. The three-way ANOVA analysis demonstrated an interaction between moment and position factors in left parietal posterior cortex (PPC (p=0.001. Through the experimental task employed, this area demonstrated a differentiated activity involving expectation, planning and preparedness in the ball's drop task.O estudo tentou elucidar mecanismos eletrofisiológicos e corticais envolvidos em ações antecipatórias quando os sujeitos testados tiveram que apreender bolas em queda livre; especificamente através de mudanças na potência absoluta na banda alfa da eletrencefalografia quantitativa (EEGq. A amostra foi composta por 23 sujeitos sadios, ambos os sexos, idade entre variando entre 25 e 40 anos, sem comprometimento físico e mental, destros, e não fazer uso de nenhuma substância psicoativa ou psicotrópicos até o momento do estudo. O experimento consistiu de uma tarefa de apreensão de bolas em queda livre. A análise three-way ANOVA demonstrou uma interação entre os fatores momento e posição no córtex parietal posterior (CPP esquerdo (p=0,001. Através da tarefa experimental empregada, esta área demonstrou uma atividade diferenciada envolvendo expectativa, planejamento e prontidão na tarefa de queda de bolas.

Fronto-Parietal Network Reconfiguration Supports the Development of Reasoning Ability.

Science.gov (United States)

Wendelken, Carter; Ferrer, Emilio; Whitaker, Kirstie J; Bunge, Silvia A

2016-05-01

The goal of this fMRI study was to examine how well developmental improvements in reasoning ability can be explained by changes in functional connectivity between specific nodes in prefrontal and parietal cortices. To this end, we examined connectivity within the lateral fronto-parietal network (LFPN) and its relation to reasoning ability in 132 children and adolescents aged 6-18 years, 56 of whom were scanned twice over the course of 1.5 years. Developmental changes in strength of connections within the LFPN were most prominent in late childhood and early adolescence. Reasoning ability was related to functional connectivity between left rostrolateral prefrontal cortex (RLPFC) and inferior parietal lobule (IPL), but only among 12-18-year olds. For 9-11-year olds, reasoning ability was most strongly related to connectivity between left and right RLPFC; this relationship was mediated by working memory. For 6-8-year olds, significant relationships between connectivity and performance were not observed; in this group, processing speed was the primary mediator of improvement in reasoning ability. We conclude that different connections best support reasoning at different points in development and that RLPFC-IPL connectivity becomes an important predictor of reasoning during adolescence. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Subtotal ablation of parietal epithelial cells induces crescent formation.

NARCIS (Netherlands)

Sicking, E.M.; Fuss, A.; Uhlig, S.; Jirak, P.; Dijkman, H.; Wetzels, J.; Engel, D.R.; Urzynicok, T.; Heidenreich, S.; Kriz, W.; Kurts, C.; Ostendorf, T.; Floege, J.; Smeets, B.; Moeller, M.J.

2012-01-01

Parietal epithelial cells (PECs) of the renal glomerulus contribute to the formation of both cellular crescents in rapidly progressive GN and sclerotic lesions in FSGS. Subtotal transgenic ablation of podocytes induces FSGS but the effect of specific ablation of PECs is unknown. Here, we established

Regional intercostal bulging of the parietal pleura

International Nuclear Information System (INIS)

Jantsch, H.; Greene, R.; Lechner, G.; Mavritz, W.; Pichler, W.; Winkler, M.; Zadrobilek, E.

1989-01-01

This paper describes bedside radiographs with localized intercostal bulging as the sole indication of tension pneumothorax in six patients with acute deterioration in gas exchange. Relief of the pneumothorax was followed by a rush of gas from the tension space and a prompt improvement in gas exchange. The authors concluded the regional intercostal bulging of the parietal pleura may be the sole indicator of life-threatening tension pneumothorax in patients on mechanical ventilation

Parietal cells?new perspectives in glomerular disease

OpenAIRE

Miesen, Laura; Steenbergen, Eric; Smeets, Bart

2017-01-01

In normal glomeruli, parietal epithelial cells (PECs) line the inside of Bowman?s capsule and form an inconspicuous sheet of flat epithelial cells in continuity with the proximal tubular epithelial cells (PTECs) at the urinary pole and with the podocytes at the vascular pole. PECs, PTECs and podocytes have a common mesenchymal origin and are the result of divergent differentiation during embryogenesis. Podocytes and PTECs are highly differentiated cells with well-established functions pertain...

Visual processing of multiple elements in the dyslexic brain: evidence for a superior parietal dysfunction

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Muriel Anne Lobier

2014-07-01

Full Text Available The visual attention (VA span deficit hypothesis of developmental dyslexia posits that impaired multiple element processing can be responsible for poor reading outcomes. In VA span impaired dyslexic children, poor performance on letter report tasks is associated with reduced parietal activations for multiple letter processing. While this hints towards a non-specific, attention-based dysfunction, it is still unclear whether reduced parietal activity generalizes to other types of stimuli. Furthermore, putative links between reduced parietal activity and reduced ventral occipito-temporal (vOT in dyslexia have yet to be explored. Using fMRI, we measured brain activity in 12 VA span impaired dyslexic adults and 12 adult skilled readers while they carried out a categorization task on single or multiple alphanumeric or non-alphanumeric characters. While healthy readers activated parietal areas more strongly for multiple than single element processing (right-sided for alphanumeric and bilateral for non-alphanumeric, similar stronger multiple element right parietal activations were absent for dyslexic participants. Contrasts between skilled and dyslexic readers revealed significantly reduced right superior parietal lobule (SPL activity for dyslexic readers regardless of stimuli type. Using a priori anatomically defined ROI, we showed that neural activity was reduced for dyslexic participants in both SPL and vOT bilaterally. Finally, we used multiple regressions to test whether SPL activity could predict vOT activity in each group. In the left hemisphere, SPL activity modulated vOT activity for both normal and dyslexic readers. In contrast, in the right hemisphere, SPL activity modulated vOT activity only for dyslexic readers. These results bring critical support to the visual attention interpretation of the VA Span deficit. In addition, they offer a new insight on how deficits in automatic vOT based word recognition could arise in developmental dyslexia.

Choline acetyltransferase-containing neurons in the human parietal neocortex

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V Benagiano

2009-06-01

Full Text Available A number of immunocytochemical studies have indicated the presence of cholinergic neurons in the cerebral cortex of various species of mammals. Whether such cholinergic neurons in the human cerebral cortex are exclusively of subcortical origin is still debated. In this immunocytochemical study, the existence of cortical cholinergic neurons was investigated on surgical samples of human parietal association neocortex using a highly specific monoclonal antibody against choline acetyltransferase (ChAT, the acetylcholine biosynthesising enzyme. ChAT immunoreactivity was detected in a subpopulation of neurons located in layers II and III. These were small or medium-sized pyramidal neurons which showed cytoplasmic immunoreactivity in the perikarya and processes, often in close association to blood microvessels. This study, providing demonstration of ChAT neurons in the human parietal neocortex, strongly supports the existence of intrinsic cholinergic innervation of the human neocortex. It is likely that these neurons contribute to the cholinergic innervation of the intracortical microvessels.

Percent wall thickness evaluated by Gd-DTPA enhanced cine MRI as an indicator of local parietal movement in hypertrophic cardiomyopathy

International Nuclear Information System (INIS)

Hirano, Masaharu

1998-01-01

Hypertrophic cardiomyopathy (HCM) is a cardiac disease, the basic pathology of which consists of a decrease in left ventricular dilation compliance due to uneven hypertrophy of the left ventricular wall. Magnetic resonance imaging (MRI) is useful in monitoring uneven parietal hypertrophy and kinetics in HCM patients. The present study was undertaken in 47 HCM patients who showed asymmetrical septal hypertrophy to determine if percent thickness can be an indicator of left ventricular local movement using cine MRI. Longest and shortest axis images were acquired by the ECG synchronization method using a 1.5 T MR imager. Cardiac function was analyzed based on longest axis cine images, and telediastolic and telesystolic parietal thickness were measured based on shorter axis cine images at the papillary muscle level. Parietal movement index and percent thickness were used as indicators of local parietal movement. The correlation between these indicators and parietal thickness was evaluated. The percent thickness changed at an earlier stage of hypertrophy than the parietal movement index, thus it is thought to be useful in detecting left ventricular parietal movement disorders at an early stage of HCM. (author)

Percent wall thickness evaluated by Gd-DTPA enhanced cine MRI as an indicator of local parietal movement in hypertrophic cardiomyopathy

Energy Technology Data Exchange (ETDEWEB)

Hirano, Masaharu [Tokyo Medical Coll. (Japan)

1998-11-01

Hypertrophic cardiomyopathy (HCM) is a cardiac disease, the basic pathology of which consists of a decrease in left ventricular dilation compliance due to uneven hypertrophy of the left ventricular wall. Magnetic resonance imaging (MRI) is useful in monitoring uneven parietal hypertrophy and kinetics in HCM patients. The present study was undertaken in 47 HCM patients who showed asymmetrical septal hypertrophy to determine if percent thickness can be an indicator of left ventricular local movement using cine MRI. Longest and shortest axis images were acquired by the ECG synchronization method using a 1.5 T MR imager. Cardiac function was analyzed based on longest axis cine images, and telediastolic and telesystolic parietal thickness were measured based on shorter axis cine images at the papillary muscle level. Parietal movement index and percent thickness were used as indicators of local parietal movement. The correlation between these indicators and parietal thickness was evaluated. The percent thickness changed at an earlier stage of hypertrophy than the parietal movement index, thus it is thought to be useful in detecting left ventricular parietal movement disorders at an early stage of HCM. (author)

Metabolic Hyperactivity of the Medial Posterior Parietal Lobes in Psychogenic Tremor

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Peter Hedera

2012-05-01

Full Text Available Background: The pathophysiology of psychogenic movement disorders, including psychogenic tremor (PT, is only emerging. Case Report: This is a single case report of a patient who met diagnostic criteria for PT. He underwent positron emission tomography (PET of brain with 18F-deoxyglucose at resting state. His PET study showed symmetrically increased 18F-deoxyglucose uptake in both posterior medial parietal lobes. There was no corresponding abnormality on structural imaging. Discussion: Hypermetabolism of the medial aspects of posterior parietal lobes bilaterally may reflect abnormal activity of sensory integration that is important in the pathogenesis of PT. This further supports the idea that non-organic movement disorders may be associated with detectable functional brain abnormalities.

Isoelectronic comparison of the Al-like 3s23p 2P-3s3p24P transitions in the ions P III-Mo XXX

International Nuclear Information System (INIS)

Jupen, C.; Curtis, L.J.

1996-01-01

New observations of the 3s 2 3p 2 P-3s3p 2 4 P intercombination transitions in Al-like ions have been made for Cl V from spark spectra recorded at Lund and for Kr XXIV and Mo XXX from spectra obtained at the JET tokamak. The new results have been combined with other identifications of these transitions along the sequence and empirically systematized and compared with theoretical calculations. A set of smoothed and interpolated values for the excitation energies of the 3s3p 2 4 P levels in P III-Mo XXX is presented. (orig.)

Induction of motor associative plasticity in the posterior parietal cortex-primary motor network

DEFF Research Database (Denmark)

Chao, Chi-Chao; Karabanov, Anke Ninija; Paine, Rainer

2015-01-01

There is anatomical and functional connectivity between the primary motor cortex (M1) and posterior parietal cortex (PPC) that plays a role in sensorimotor integration. In this study, we applied corticocortical paired-associative stimuli to ipsilateral PPC and M1 (parietal ccPAS) in healthy right......-handed subjects to test if this procedure could modulate M1 excitability and PPC–M1 connectivity. One hundred and eighty paired transcranial magnetic stimuli to the PPC and M1 at an interstimulus interval (ISI) of 8 ms were delivered at 0.2 Hz. We found that parietal ccPAS in the left hemisphere increased...... the excitability of conditioned left M1 assessed by motor evoked potentials (MEPs) and the input–output curve. Motor behavior assessed by the Purdue pegboard task was unchanged compared with controls. At baseline, conditioning stimuli over the left PPC potentiated MEPs from left M1 when ISI was 8 ms...

Sensory-parietal cortical stimulation improves motor recovery in severe capsular infarct.

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Kim, Ra Gyung; Cho, Jongwook; Ree, Jinkyue; Kim, Hyung-Sun; Rosa-Neto, Pedro; Kim, Jin-Myung; Lee, Min-Cheol; Kim, Hyoung-Ihl

2016-12-01

The prevalence of subcortical white matter strokes in elderly patients is on the rise, but these patients show mixed responses to conventional rehabilitative interventions. To examine whether cortical electrical stimulation can promote motor recovery after white matter stroke, we delivered stimulation to a small or wide region of sensory-parietal cortex for two weeks in a rodent model of circumscribed subcortical capsular infarct. The sham-operated group (SOG) showed persistent and severe motor impairments together with decreased activation in bilateral sensorimotor cortices and striatum. In contrast, sensory-parietal cortex stimulation significantly improved motor recovery: final recovery levels were 72.9% of prelesion levels in the wide stimulation group (WSG) and 37% of prelesion levels in the small stimulation group (SSG). The microPET imaging showed reversal of cortical diaschisis in both groups: in both hemispheres for the WSG, and in the hemisphere ipsilateral to stimulation in the SSG. In addition, we observed activation of the corpus callosum and subcortical corticostriatal structures after stimulation. The results from the c-Fos mapping study were grossly consistent with the microPET imaging. Sensory-parietal cortex stimulation may therefore be a useful strategy for overcoming the limits of rehabilitative training in patients with severe forms of subcortical capsular infarct. © The Author(s) 2015.

Functional Dissociation of Latency-Variable, Stimulus- and Response-Locked Target P3 Sub-components in Task-Switching.

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Brydges, Christopher R; Barceló, Francisco

2018-01-01

Cognitive control warrants efficient task performance in dynamic and changing environments through adjustments in executive attention, stimulus and response selection. The well-known P300 component of the human event-related potential (ERP) has long been proposed to index "context-updating"-critical for cognitive control-in simple target detection tasks. However, task switching ERP studies have revealed both target P3 (300-350 ms) and later sustained P3-like potentials (400-1,200 ms) to first targets ensuing transition cues, although it remains unclear whether these target P3-like potentials also reflect context updating operations. To address this question, we applied novel single-trial EEG analyses-residue iteration decomposition (RIDE)-in order to disentangle target P3 sub-components in a sample of 22 young adults while they either repeated or switched (updated) task rules. The rationale was to revise the context updating hypothesis of P300 elicitation in the light of new evidence suggesting that "the context" consists of not only the sensory units of stimulation, but also associated motor units, and intermediate low- and high-order sensorimotor units, all of which may need to be dynamically updated on a trial by trial basis. The results showed functionally distinct target P3-like potentials in stimulus-locked, response-locked, and intermediate RIDE component clusters overlying parietal and frontal regions, implying multiple functionally distinct, though temporarily overlapping context updating operations. These findings support a reformulated version of the context updating hypothesis, and reveal a rich family of distinct target P3-like sub-components during the reactive control of target detection in task-switching, plausibly indexing the complex and dynamic workings of frontoparietal cortical networks subserving cognitive control.

Neural representations of social status hierarchy in human inferior parietal cortex.

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Chiao, Joan Y; Harada, Tokiko; Oby, Emily R; Li, Zhang; Parrish, Todd; Bridge, Donna J

2009-01-01

Mental representations of social status hierarchy share properties with that of numbers. Previous neuroimaging studies have shown that the neural representation of numerical magnitude lies within a network of regions within inferior parietal cortex. However the neural basis of social status hierarchy remains unknown. Using fMRI, we studied subjects while they compared social status magnitude of people, objects and symbols, as well as numerical magnitude. Both social status and number comparisons recruited bilateral intraparietal sulci. We also observed a semantic distance effect whereby neural activity within bilateral intraparietal sulci increased for semantically close relative to far numerical and social status comparisons. These results demonstrate that social status and number comparisons recruit distinct and overlapping neuronal representations within human inferior parietal cortex.

An enlarged parietal foramen in the late archaic Xujiayao 11 neurocranium from Northern China, and rare anomalies among Pleistocene Homo.

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Wu, Xiu-Jie; Xing, Song; Trinkaus, Erik

2013-01-01

We report here a neurocranial abnormality previously undescribed in Pleistocene human fossils, an enlarged parietal foramen (EPF) in the early Late Pleistocene Xujiayao 11 parietal bones from the Xujiayao (Houjiayao) site, northern China. Xujiayao 11 is a pair of partial posteromedial parietal bones from an adult. It exhibits thick cranial vault bones, arachnoid granulations, a deviated posterior sagittal suture, and a unilateral (right) parietal lacuna with a posteriorly-directed and enlarged endocranial vascular sulcus. Differential diagnosis indicates that the perforation is a congenital defect, an enlarged parietal foramen, commonly associated with cerebral venous and cranial vault anomalies. It was not lethal given the individual's age-at-death, but it may have been associated with secondary neurological deficiencies. The fossil constitutes the oldest evidence in human evolution of this very rare condition (a single enlarged parietal foramen). In combination with developmental and degenerative abnormalities in other Pleistocene human remains, it suggests demographic and survival patterns among Pleistocene Homo that led to an elevated frequency of conditions unknown or rare among recent humans.

An enlarged parietal foramen in the late archaic Xujiayao 11 neurocranium from Northern China, and rare anomalies among Pleistocene Homo.

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Xiu-Jie Wu

Full Text Available We report here a neurocranial abnormality previously undescribed in Pleistocene human fossils, an enlarged parietal foramen (EPF in the early Late Pleistocene Xujiayao 11 parietal bones from the Xujiayao (Houjiayao site, northern China. Xujiayao 11 is a pair of partial posteromedial parietal bones from an adult. It exhibits thick cranial vault bones, arachnoid granulations, a deviated posterior sagittal suture, and a unilateral (right parietal lacuna with a posteriorly-directed and enlarged endocranial vascular sulcus. Differential diagnosis indicates that the perforation is a congenital defect, an enlarged parietal foramen, commonly associated with cerebral venous and cranial vault anomalies. It was not lethal given the individual's age-at-death, but it may have been associated with secondary neurological deficiencies. The fossil constitutes the oldest evidence in human evolution of this very rare condition (a single enlarged parietal foramen. In combination with developmental and degenerative abnormalities in other Pleistocene human remains, it suggests demographic and survival patterns among Pleistocene Homo that led to an elevated frequency of conditions unknown or rare among recent humans.

10 Hz rTMS over right parietal cortex alters sense of agency during self-generated movements

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Anina eRitterband-Rosenbaum

2014-06-01

Full Text Available A large body of fMRI and lesion-literature has provided evidence that the Inferior Parietal Cortex (IPC is important for sensorimotor integration and sense of agency (SoA. We used repetitive transcranial magnetic stimulation (rTMS to explore the role of the IPC during a validated SoA detection task. 12 healthy, right-handed adults were included. The effects of rTMS on subjects’ SoA during self-generated movements were explored. The experiment consisted of 1/3 self-generated movements and 2/3 computer manipulated movements that introduced uncertainty as to whether the subjects were agents of an observed movement. Subjects completed three sessions, in which subjects received online rTMS over the right IPC (active condition, over the vertex (CZ (sham condition or no TMS but a sound-matched control. We found that rTMS over right IPC significantly altered SoA of the non-perturbed movements. Following IPC stimulation subjects were more likely to experience self-generated movements as being externally perturbed compared to the control site (P=0.002 and the stimulation-free control (P=0.042. The data support the importance of IPC activation during sensorimotor comparison in order to correctly determine the agent of movements.

Classification of single normal and Alzheimer’s disease individuals from cortical sources of resting state EEG rhythms

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Claudio eBabiloni

2016-02-01

Full Text Available Previous studies have shown abnormal power and functional connectivity of resting state electroencephalographic (EEG rhythms in groups of Alzheimer’s disease (AD compared to healthy elderly (Nold subjects. Here we tested the best classification rate of 120 AD patients and 100 matched Nold subjects using EEG markers based on cortical sources of power and functional connectivity of these rhythms. EEG data were recorded during resting state eyes-closed condition. Exact low-resolution brain electromagnetic tomography (eLORETA estimated the power and functional connectivity of cortical sources in frontal, central, parietal, occipital, temporal, and limbic regions. Delta (2-4 Hz, theta (4-8 Hz, alpha 1 (8-10.5 Hz, alpha 2 (10.5-13 Hz, beta 1 (13-20 Hz, beta 2 (20-30 Hz, and gamma (30-40 Hz were the frequency bands of interest. The classification rates of interest were those with an area under the receiver operating characteristic curve (AUROC higher than 0.7 as a threshold for a moderate classification rate (i.e. 70%. Results showed that the following EEG markers overcame this threshold: (i central, parietal, occipital, temporal, and limbic delta/alpha 1 current density; (ii central, parietal, occipital temporal, and limbic delta/alpha 2 current density; (iii frontal theta/alpha 1 current density; (iv occipital delta/alpha 1 inter-hemispherical connectivity; (v occipital-temporal theta/alpha 1 right and left intra-hemispherical connectivity; and (vi parietal-limbic alpha 1 right intra-hemispherical connectivity. Occipital delta/alpha 1 current density showed the best classification rate (sensitivity of 73.3%, specificity of 78%, accuracy of 75.5%, and AUROC of 82%. These results suggest that EEG source markers can classify Nold and AD individuals with a moderate classification rate higher than 80%.

The regenerative potential of parietal epithelial cells in adult mice

NARCIS (Netherlands)

Berger, K.; Schulte, K.; Boor, P.; Kuppe, C.; Kuppevelt, T.H. van; Floege, J.; Smeets, B.; Moeller, M.J.

2014-01-01

Previously, we showed that some podocytes in juvenile mice are recruited from cells lining Bowman's capsule, suggesting that parietal epithelial cells (PECs) are a progenitor cell population for podocytes. To investigate whether PECs also replenish podocytes in adult mice, PECs were genetically

Effect of pH and nitrogen source in carboxylation by seedlings of wheat and maize

International Nuclear Information System (INIS)

Garcia Pineda, D.; Saez, R.M.; Solano, M.L.

1983-01-01

Carboxylation has been studied in leaves homogenate, expressed as RuBP-carboxylase activity, using as one of the substrates NaH 14 CO 3 , and giving the acitivity value as nanomols of 14 CO 2 incorporated by mg.. of protein per minute in the determined conditions. The variable is the pH of the culture media. Cultures has been studied with pH values between 3.5 and 6.2. Three different nitrogen sources has been used, carefully calculating the composition of each medium in order that all of them have same nitrogen content:1) Nitrate medium, 2) Ammonium sulfate medium and 3) Ammonium nitrate medium. The results are presented graphically with a discussion about them. It is shown that the effect of pH is less pronounced in maize that in wheat, with NO 3 nitrogen source that with NH 4 + , and in plants 28 days age than in plants 7 days age. (author)

[Successive subcortical hemorrhages in the superior parietal lobule and postcentral gyrus in a 23-year-old female].

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Sato, K; Yoshikawa, H; Komai, K; Takamori, M

1998-04-01

We report a non-hypertensive 23-year-old female with successive hemorrhages in parietal subcortical regions. She had first experienced a transient pain in the left upper extremity one month before admission. She noticed dysesthesia in the same limb and weakness on her left hand, and, five days after, visited our hospital because of suddenly developed convulsion in the limb and loss of consciousness for a few minutes. Neurological examination revealed distal dominant flaccid paresis, positive pathological reflex and touch and position sense disturbances in the affected limb. Brain CT detected two high-density areas in the parietal lobe. Brain MRI demonstrated an acute phase subcortical hematoma in the left postcentral gyrus and a subacute phase one in the left superior parietal lobule. SPECT indicated hypoperfusion in the left frontal and parietal cortex. Cerebral angiography showed no abnormal findings. Her symptoms gradually improved, but left ulnar-type pseudoradicular sensory impairment remained on discharge. We considered the hemorrhage in this patient have arisen from rupture of cavernous hemangioma, because she was relatively young, the hematomas were oval in shape and successively developed in the left parietal lobe. Our patient suggests that a subcortical hemorrhage in the post-central gyrus causes flaccid paresis and pyramidal tract involvement.

Seeing is not feeling: posterior parietal but not somatosensory cortex engagement during touch observation.

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Chan, Annie W-Y; Baker, Chris I

2015-01-28

Observing touch has been reported to elicit activation in human primary and secondary somatosensory cortices and is suggested to underlie our ability to interpret other's behavior and potentially empathy. However, despite these reports, there are a large number of inconsistencies in terms of the precise topography of activation, the extent of hemispheric lateralization, and what aspects of the stimulus are necessary to drive responses. To address these issues, we investigated the localization and functional properties of regions responsive to observed touch in a large group of participants (n = 40). Surprisingly, even with a lenient contrast of hand brushing versus brushing alone, we did not find any selective activation for observed touch in the hand regions of somatosensory cortex but rather in superior and inferior portions of neighboring posterior parietal cortex, predominantly in the left hemisphere. These regions in the posterior parietal cortex required the presence of both brush and hand to elicit strong responses and showed some selectivity for the form of the object or agent of touch. Furthermore, the inferior parietal region showed nonspecific tactile and motor responses, suggesting some similarity to area PFG in the monkey. Collectively, our findings challenge the automatic engagement of somatosensory cortex when observing touch, suggest mislocalization in previous studies, and instead highlight the role of posterior parietal cortex. Copyright © 2015 the authors 0270-6474/15/351468-13$15.00/0.

Observing complex action sequences: The role of the fronto-parietal mirror neuron system.

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Molnar-Szakacs, Istvan; Kaplan, Jonas; Greenfield, Patricia M; Iacoboni, Marco

2006-11-15

A fronto-parietal mirror neuron network in the human brain supports the ability to represent and understand observed actions allowing us to successfully interact with others and our environment. Using functional magnetic resonance imaging (fMRI), we wanted to investigate the response of this network in adults during observation of hierarchically organized action sequences of varying complexity that emerge at different developmental stages. We hypothesized that fronto-parietal systems may play a role in coding the hierarchical structure of object-directed actions. The observation of all action sequences recruited a common bilateral network including the fronto-parietal mirror neuron system and occipito-temporal visual motion areas. Activity in mirror neuron areas varied according to the motoric complexity of the observed actions, but not according to the developmental sequence of action structures, possibly due to the fact that our subjects were all adults. These results suggest that the mirror neuron system provides a fairly accurate simulation process of observed actions, mimicking internally the level of motoric complexity. We also discuss the results in terms of the links between mirror neurons, language development and evolution.

Probing the early development of visual working memory capacity with functional near-infrared spectroscopy.

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Buss, Aaron T; Fox, Nicholas; Boas, David A; Spencer, John P

2014-01-15

Visual working memory (VWM) is a core cognitive system with a highly limited capacity. The present study is the first to examine VWM capacity limits in early development using functional neuroimaging. We recorded optical neuroimaging data while 3- and 4-year-olds completed a change detection task where they detected changes in the shapes of objects after a brief delay. Near-infrared sources and detectors were placed over the following 10-20 positions: F3 and F5 in left frontal cortex, F4 and F6 in right frontal cortex, P3 and P5 in left parietal cortex, and P4 and P6 in right parietal cortex. The first question was whether we would see robust task-specific activation of the frontal-parietal network identified in the adult fMRI literature. This was indeed the case: three left frontal channels and 11 of 12 parietal channels showed a statistically robust difference between the concentration of oxygenated and deoxygenated hemoglobin following the presentation of the sample array. Moreover, four channels in the left hemisphere near P3, P5, and F5 showed a robust increase as the working memory load increased from 1 to 3 items. Notably, the hemodynamic response did not asymptote at 1-2 items as expected from previous fMRI studies with adults. Finally, 4-year-olds showed a more robust parietal response relative to 3-year-olds, and an increasing sensitivity to the memory load manipulation. These results demonstrate that fNIRS is an effective tool to study the neural processes that underlie the early development of VWM capacity. Copyright © 2013 Elsevier Inc. All rights reserved.

Antigastric parietal cell and antithyroid autoantibodies in patients with desquamative gingivitis.

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Chang, Julia Yu-Fong; Chiang, Chun-Pin; Wang, Yi-Ping; Wu, Yang-Che; Chen, Hsin-Ming; Sun, Andy

2017-04-01

Desquamative gingivitis (DG) is principally associated with erosive oral lichen planus (EOLP), mucous membrane pemphigoid (MMP), and pemphigus vulgaris (PV). Serum autoantibodies including antigastric parietal cell antibody (GPCA), antithyroglobulin antibody (TGA), and antithyroid microsomal antibody (TMA) were measured in 500 patients with DG, 287 EOLP without DG (EOLP/DG - ) patients, and 100 healthy control subjects. The 500 patients with DG were diagnosed as having EOLP in 455 (91%), PV in 40 (8%), and MMP in five (1%) patients. We found that 37.0%, 43.6%, and 42.6% of 500 patients with DG, 39.6%, 46.4%, and 45.1% of 455 EOLP with DG (EOLP/DG) patients, and 18.5%, 27.5%, and 30.3% of 287 EOLP/DG - patients had the presence of GPCA, TGA, and TMA in their sera, respectively. DG, EOLP/DG, and EOLP/DG - patients all had a significantly higher frequency of GPCA, TGA, or TMA positivity than healthy control subjects (all P-values < 0.001). Moreover, 455 EOLP/DG patients had a significantly higher frequency of GPCA, TGA, or TMA positivity than 287 EOLP/DG - patients (all P-values < 0.001). Of 210 TGA/TMA-positive patients with DG whose serum thyroid-stimulating hormone (TSH) levels were measured, 84.3%, 6.7%, and 9.0% patients had normal, lower, and higher serum TSH levels, respectively. We conclude that 73.4% DG, 77.1% EOLP/DG, and 47.4% EOLP/DG - patients may have GPCA/TGA/TMA positivity in their sera. Because part of GPCA-positive patients may develop pernicious anemia, autoimmune atrophic gastritis, and gastric carcinoma, and part of TGA/TMA-positive patients may have thyroid dysfunction, these patients should be referred to medical department for further management. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Brain-behavior relationships in source memory: Effects of age and memory ability.

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Meusel, Liesel-Ann; Grady, Cheryl L; Ebert, Patricia E; Anderson, Nicole D

2017-06-01

There is considerable evidence for age-related decrements in source memory retrieval, but the literature on the neural correlates of these impairments is mixed. In this study, we used functional magnetic resonance imaging to examine source memory retrieval-related brain activity, and the monotonic relationship between retrieval-related brain activity and source memory accuracy, as a function of both healthy aging (younger vs older) and memory ability within the older adult group (Hi-Old vs Lo-Old). Participants studied lists of word pairs, half visually, half aurally; these were re-presented visually in a scanned test phase and participants indicated if the pair was 'seen' or 'heard' in the study phase. The Lo-Old, but not the Hi-Old, showed source memory performance decrements compared to the Young. During retrieval of source memories, younger and older adults engaged lateral and medial prefrontal cortex (PFC) and medial posterior parietal (and occipital) cortices. The groups differed in how brain activity related to source memory accuracy in dorsal anterior cingulate cortex, precuneus/cuneus, and the inferior parietal cortex; in each of these areas, greater activity was associated with poorer accuracy in the Young, but with higher accuracy in the Hi-Old (anterior cingulate and precuneus/cuneus) and Lo-Old (inferior parietal lobe). Follow-up pairwise group interaction analyses revealed that greater activity in right parahippocampal gyrus was associated with better source memory in the Hi-Old, but not in the Lo-Old. We conclude that older adults recruit additional brain regions to compensate for age-related decline in source memory, but the specific regions involved differ depending on their episodic memory ability. Copyright © 2017 Elsevier Ltd. All rights reserved.

Orbitofrontal cortex contribution to working memory. N-back ERP study

International Nuclear Information System (INIS)

Nakao, Yoshiaki; Tamura, Toshiyo; Kodabashi, Atsushi; Fujimoto, Toshiro; Yarita, Masaru

2011-01-01

Remarkable progress in cognitive neuroscience has revealed the involvement of the prefrontal cortex and the orbitofrontal cortex in human working memory, but the orbitofrontal cortex is still one of the least understood regions in the human brain. To elucidate the contribution of the orbitofrontal cortex to human working memory, we studied electroencephalography (EEG) P300 activity in n-back task. We elicited early P3 around 300 ms and late P3 around 360 ms of P300 components in n-back event related potentials (ERP). The amplitudes of the respective peaks changed depending on the working memory load (0-back, 1-back, 2-back, 3-back). We used source analysis to evaluate the orbitofrontal cortex in P3 components. A source model was constructed with the sources seeded from fMRI meta-analysis of n-back task and additional sources in the orbitofrontal cortex and the visual cortex estimated with P100 and late P3 components in the n-back ERP. This source model had more than 99% of GOF (goodness of fit) in n-back ERP. It gave us an insight of brain activity at the positions where sources existed. Early P3 was mainly produced by the dorsolateral prefrontal cortex, the ventrolateral prefrontal cortex, the inferior parietal lobule, the medial posterior parietal and the visual cortex. Late P3 was mainly produced by the medial premotor, the lateral premotor, the frontal pole and the orbitofrontal cortex. The contribution of the frontal pole and the orbitofrontal cortex had peaks around 390 ms which were later than late P3 component. In this study, the method to evaluate the orbitofrontal cortex activity in n-back ERP was provided. Our results elicited the involvement of the orbitofrontal cortex in late P3 component of n-back ERP. (author)

Right hemisphere dominance during spatial selective attention and target detection occurs outside the dorsal fronto-parietal network

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Shulman, Gordon L.; Pope, Daniel L. W.; Astafiev, Serguei V.; McAvoy, Mark P.; Snyder, Abraham Z.; Corbetta, Maurizio

2010-01-01

Spatial selective attention is widely considered to be right hemisphere dominant. Previous functional magnetic resonance imaging (fMRI) studies, however, have reported bilateral blood-oxygenation-level-dependent (BOLD) responses in dorsal fronto-parietal regions during anticipatory shifts of attention to a location (Kastner et al., 1999; Corbetta et al., 2000; Hopfinger et al., 2000). Right-lateralized activity has mainly been reported in ventral fronto-parietal regions for shifts of attention to an unattended target stimulus (Arrington et al., 2000; Corbetta et al., 2000). However, clear conclusions cannot be drawn from these studies because hemispheric asymmetries were not assessed using direct voxel-wise comparisons of activity in left and right hemispheres. Here, we used this technique to measure hemispheric asymmetries during shifts of spatial attention evoked by a peripheral cue stimulus and during target detection at the cued location. Stimulus-driven shifts of spatial attention in both visual fields evoked right-hemisphere dominant activity in temporo-parietal junction (TPJ). Target detection at the attended location produced a more widespread right hemisphere dominance in frontal, parietal, and temporal cortex, including the TPJ region asymmetrically activated during shifts of spatial attention. However, hemispheric asymmetries were not observed during either shifts of attention or target detection in the dorsal fronto-parietal regions (anterior precuneus, medial intraparietal sulcus, frontal eye fields) that showed the most robust activations for shifts of attention. Therefore, right hemisphere dominance during stimulus-driven shifts of spatial attention and target detection reflects asymmetries in cortical regions that are largely distinct from the dorsal fronto-parietal network involved in the control of selective attention. PMID:20219998

Gln3p and Nil1p regulation of invertase activity and SUC2 expression in Saccharomyces cerevisiae.

Science.gov (United States)

Oliveira, Edna Maria Morais; Mansure, José João; Bon, Elba Pinto da Silva

2005-04-01

In Saccharomyces cerevisiae, sensing and signalling pathways regulate gene expression in response to quality of carbon and nitrogen sources. One such system, the target of rapamycin (Tor) proteins, senses nutrients and uses the GATA activators Gln3p and Nil1p to regulate translation in response to low-quality carbon and nitrogen. The signal transduction, triggered in response to nitrogen nutrition that is sensed by the Tor proteins, operates via a regulatory pathway involving the cytoplasmic factor Ure2p. When carbon and nitrogen are abundant, the phosphorylated Ure2p anchors the also phosphorylated Gln3p and Nil1p in the cytoplasm. Upon a shift from high- to low-quality nitrogen or treatment with rapamycin all three proteins are dephosphorylated, causing Gln3p and Nil1p to enter the nucleus and promote transcription. The genes that code for yeast periplasmic enzymes with nutritional roles would be obvious targets for regulation by the sensing and signalling pathways that respond to quality of carbon and nitrogen sources. Indeed, previous results from our laboratory had shown that the GATA factors Gln3p, Nil1p, Dal80p, Nil2p and also the protein Ure2 regulate the expression of asparaginase II, coded by ASP3. We also had observed that the activity levels of the also periplasmic invertase, coded by SUC2, were 6-fold lower in ure2 mutant cells in comparison to wild-type cells collected at stationary phase. These results suggested similarities between the signalling pathways regulating the expression of ASP3 and SUC2. In the present work we showed that invertase levels displayed by the single nil1 and gln3 and by the double gln3nil1 mutant cells, cultivated in a sucrose-ammonium medium and collected at the exponential phase, were 6-, 10- and 60-fold higher, respectively, in comparison to their wild-type counterparts. RT-PCR data of SUC2 expression in the double-mutant cells indicated a 10-fold increase in the mRNA(SUC2) levels.

Unique and shared roles of the posterior parietal and dorsolateral prefrontal cortex in cognitive functions

Directory of Open Access Journals (Sweden)

Fumi eKatsuki

2012-05-01

Full Text Available The dorsolateral prefrontal and posterior parietal cortex are two parts of a broader brain network involved in the control of cognitive functions such as working memory, spatial attention, and decision making. The two areas share many functional properties and exhibit similar patterns of activation during the execution of mental operations. However, neurophysiological experiments in non-human primates have also documented subtle differences, revealing functional specialization within the fronto-parietal network. These differences include the ability of the dorsolateral prefrontal cortex to influence memory performance, attention allocation and motor responses to a greater extent, and to resist interference by distracting stimuli. In recent years, distinct cellular and anatomical differences have been identified, offering insights into how functional specialization is achieved. This article reviews the common functions and functional differences between the dorsolateral prefrontal and posterior parietal cortex, and their underlying mechanisms.

Increased gray matter density in the parietal cortex of mathematicians: a voxel-based morphometry study.

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Aydin, K; Ucar, A; Oguz, K K; Okur, O O; Agayev, A; Unal, Z; Yilmaz, S; Ozturk, C

2007-01-01

The training to acquire or practicing to perform a skill, which may lead to structural changes in the brain, is called experience-dependent structural plasticity. The main purpose of this cross-sectional study was to investigate the presence of experience-dependent structural plasticity in mathematicians' brains, which may develop after long-term practice of mathematic thinking. Twenty-six volunteer mathematicians, who have been working as academicians, were enrolled in the study. We applied an optimized method of voxel-based morphometry in the mathematicians and the age- and sex-matched control subjects. We assessed the gray and white matter density differences in mathematicians and the control subjects. Moreover, the correlation between the cortical density and the time spent as an academician was investigated. We found that cortical gray matter density in the left inferior frontal and bilateral inferior parietal lobules of the mathematicians were significantly increased compared with the control subjects. Furthermore, increase in gray matter density in the right inferior parietal lobule of the mathematicians was strongly correlated with the time spent as an academician (r = 0.84; P mathematicians' brains revealed increased gray matter density in the cortical regions related to mathematic thinking. The correlation between cortical density increase and the time spent as an academician suggests experience-dependent structural plasticity in mathematicians' brains.

Collaborative activity between parietal and dorso-lateral prefrontal cortex in dynamic spatial working memory revealed by fMRI.

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Diwadkar, V A; Carpenter, P A; Just, M A

2000-07-01

Functional MRI was used to determine how the constituents of the cortical network subserving dynamic spatial working memory respond to two types of increases in task complexity. Participants mentally maintained the most recent location of either one or three objects as the three objects moved discretely in either a two- or three-dimensional array. Cortical activation in the dorsolateral prefrontal (DLPFC) and the parietal cortex increased as a function of the number of object locations to be maintained and the dimensionality of the display. An analysis of the response characteristics of the individual voxels showed that a large proportion were activated only when both the variables imposed the higher level of demand. A smaller proportion were activated specifically in response to increases in task demand associated with each of the independent variables. A second experiment revealed the same effect of dimensionality in the parietal cortex when the movement of objects was signaled auditorily rather than visually, indicating that the additional representational demands induced by 3-D space are independent of input modality. The comodulation of activation in the prefrontal and parietal areas by the amount of computational demand suggests that the collaboration between areas is a basic feature underlying much of the functionality of spatial working memory. Copyright 2000 Academic Press.

Vulnerability of the frontal and parietal regions in hypertensive patients during working memory task.

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Li, Xin; Wang, Wenxiao; Wang, Ailin; Li, Peng; Zhang, Junying; Tao, Wuhai; Zhang, Zhanjun

2017-05-01

Hypertension is related with cognitive decline in the elderly. The frontal-parietal executive system plays an important role in cognitive aging and is also vulnerable to damage in elderly patients with hypertension. Examination of the brain's functional characteristics in frontal-parietal regions of hypertension is likely to be important for understanding the neural mechanisms of hypertension's effect on cognitive aging. We address this issue by comparing hypertension and control-performers in a functional MRI study. Twenty-eight hypertensive patients and 32 elderly controls were tested with n-back task with two load levels. The hypertensive patients exhibited worse executive and memory abilities than control subjects. The patterns of brain activation changed under different working memory loads in the hypertensive patients, who exhibited reduced activation only in the precentral gyrus under low loads and reduced activation in the middle frontal gyrus, left medial superior frontal gyrus and right precuneus under high loads. Thus, more regions of diminished activation were observed in the frontal and parietal regions with increasing task difficulty. More importantly, we found that lower activation in changed frontal and parietal regions was associated with worse cognitive function in high loads. The results demonstrate the relationship between cognitive function and frontoparietal functional activation in hypertension and their relevance to cognitive aging risk. Our findings provide a better understanding of the mechanism of cognitive decline in hypertension and highlight the importance of brain protection in hypertension.

Cerebral (1)H MRS alterations in recreational 3, 4-methylenedioxymethamphetamine (MDMA, "ecstasy") users.

Science.gov (United States)

Chang, L; Ernst, T; Grob, C S; Poland, R E

1999-10-01

3,4-methylenedioxymethamphetamine (MDMA) is an illicit drug that has been associated with serotonergic axonal degeneration in animals. This study evaluates neurochemical abnormalities in recreational MDMA users. Twenty-two MDMA users and 37 normal subjects were evaluated with magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy ((1)H MRS) in the mid-frontal, mid-occipital, and parietal brain regions. (1)H MRS showed normal N-acetyl (NA) compounds in all brain regions. The myo-inositol (MI) concentration (+16.3%, P = 0.04) and the MI to creatine (CR) ratio (+14.1%, P = 0. 01) were increased in the parietal white matter of MDMA users. The cumulative lifetime MDMA dose showed significant effects on [MI] in the parietal white matter and the occipital cortex. The normal NA concentration suggests a lack of significant neuronal injury in recreational MDMA users. However, the usage-related increase in MI suggests that exposure to MDMA, even at recreational doses, may cause increased glial content. J. Magn. Reson. Imaging 1999;10:521-526. Copyright 1999 Wiley-Liss, Inc.

Source Monitoring 15 Years Later: What Have We Learned from fMRI about the Neural Mechanisms of Source Memory?

Science.gov (United States)

Mitchell, Karen J.; Johnson, Marcia K.

2009-01-01

Focusing primarily on functional magnetic resonance imaging (fMRI), this article reviews evidence regarding the roles of subregions of the medial temporal lobes, prefrontal cortex, posterior representational areas, and parietal cortex in source memory. In addition to evidence from standard episodic memory tasks assessing accuracy for neutral…

Connections of the medial posterior parietal cortex (area 7m) in the monkey.

Science.gov (United States)

Leichnetz, G R

2001-06-01

The afferent and efferent cortical and subcortical connections of the medial posterior parietal cortex (area 7m) were studied in cebus (Cebus apella) and macaque (Macaca fascicularis) monkeys using the retrograde and anterograde capabilities of the horseradish peroxidase (HRP) technique. The principal intraparietal corticocortical connections of area 7m in both cebus and macaque cases were with the ipsilateral medial bank of the intraparietal sulcus (MIP) and adjacent superior parietal lobule (area 5), inferior parietal lobule (area 7a), lateral bank of the IPS (area 7ip), caudal parietal operculum (PGop), dorsal bank of the caudal superior temporal sulcus (visual area MST), and medial prestriate cortex (including visual area PO and caudal medial lobule). Its principal frontal corticocortical connections were with the prefrontal cortex in the shoulder above the principal sulcus and the cortex in the shoulder above the superior ramus of the arcuate sulcus (SAS), the area purported to contain the smooth eye movement-related frontal eye field (FEFsem) in the cebus monkey by other investigators. There were moderate connections with the cortex in the rostral bank of the arcuate sulcus (purported to contain the saccade-related frontal eye field; FEFsac), supplementary eye field (SEF), and rostral dorsal premotor area (PMDr). Area 7m also had major connections with the cingulate cortex (area 23), particularly the ventral bank of the cingulate sulcus. The principal subcortical connections of area 7m were with the dorsal portion of the ventrolateral thalamic (VLc) nucleus, lateral posterior thalamic nucleus, lateral pulvinar, caudal mediodorsal thalamic nucleus and medial pulvinar, central lateral, central superior lateral, and central inferior intralaminar thalamic nuclei, dorsolateral caudate nucleus and putamen, middle region of the claustrum, nucleus of the diagonal band, zona incerta, pregeniculate nucleus, anterior and posterior pretectal nuclei, intermediate layer of

EEG UPPER/LOW ALPHA FREQUENCY POWER RATIO RELATES TO TEMPORO-PARIETAL BRAIN ATROPHY AND MEMORY PERFORMANCES IN MILD COGNITIVE IMPAIRMENT

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Davide Vito Moretti

2013-10-01

Full Text Available Objective: temporo-parietal cortex thinning is associated to mild cognitive impairment (MCI due to Alzheimer disease (AD. The increase of EEG upper/low alpha power ratio has been associated with AD-converter MCI subjects. We investigated the association of alpha3/alpha2 ratio with patterns of cortical thickness in MCI.Methods: 74 adult subjects with MCI underwent clinical and neuropsychological evaluation, electroencephalogram (EEG recording and high resolution 3D magnetic resonance imaging (MRI. Alpha3/alpha2 power ratio as well as cortical thickness was computed for each subject. Three MCI groups were detected according to increasing tertile values of upper/low alpha power ratio . Difference of cortical thikness among the groups was estimated. Pearson’s r was used to assess the topography of the correlation between cortical thinning and memory impairment.Results: High upper/low alpha power ratio group had total cortical grey matter (CGM volume reduction of 471 mm2 than low upper/low alpha power ratio group (p

Inconsistent Effects of Parietal α-tACS on Pseudoneglect across Two Experiments: A Failed Internal Replication

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Domenica Veniero

2017-06-01

Full Text Available Transcranial electrical stimulation (tES is being investigated as an experimental and clinical interventional technique in human participants. While promising, important limitations have been identified, including weak effect sizes and high inter- and intra-individual variability of outcomes. Here, we compared two “inhibitory” tES-techniques with supposedly different mechanisms of action as to their effects on performance in a visuospatial attention task, and report on a direct replication attempt. In two experiments, 2 × 20 healthy participants underwent tES in three separate sessions testing different protocols (10 min stimulation each with a montage targeting right parietal cortex (right parietal–left frontal, electrode-sizes: 3cm × 3cm–7 cm × 5 cm, while performing a perceptual line bisection (landmark task. The tES-protocols were compared as to their ability to modulate pseudoneglect (thought to be under right hemispheric control. In experiment 1, sham-tES was compared to transcranial alternating current stimulation at alpha frequency (10 Hz; α-tACS (expected to entrain “inhibitory” alpha oscillations and to cathodal transcranial direct current stimulation (c-tDCS (shown to suppress neuronal spiking activity. In experiment 2, we attempted to replicate the findings of experiment 1, and establish frequency-specificity by adding a 45 Hz-tACS condition to α-tACS and sham. In experiment 1, right parietal α-tACS led to the expected changes in spatial attention bias, namely a rightward shift in subjective midpoint estimation (relative to sham. However, this was not confirmed in experiment 2 and in the complete sample. Right parietal c-tDCS and 45 Hz-tACS had no effect. These results highlight the importance of replication studies, adequate statistical power and optimizing tES-interventions for establishing the robustness and reliability of electrical stimulation effects, and best practice.

Automatic and Intentional Number Processing Both Rely on Intact Right Parietal Cortex: A Combined fMRI and Neuronavigated TMS Study

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Cohen Kadosh, Roi; Bien, Nina; Sack, Alexander T.

2012-01-01

Practice and training usually lead to performance increase in a given task. In addition, a shift from intentional toward more automatic processing mechanisms is often observed. It is currently debated whether automatic and intentional processing is subserved by the same or by different mechanism(s), and whether the same or different regions in the brain are recruited. Previous correlational evidence provided by behavioral, neuroimaging, modeling, and neuropsychological studies addressing this question yielded conflicting results. Here we used transcranial magnetic stimulation (TMS) to compare the causal influence of disrupting either left or right parietal cortex during automatic and intentional numerical processing, as reflected by the size congruity effect and the numerical distance effect, respectively. We found a functional hemispheric asymmetry within parietal cortex with only the TMS-induced right parietal disruption impairing both automatic and intentional numerical processing. In contrast, disrupting the left parietal lobe with TMS, or applying sham stimulation, did not affect performance during automatic or intentional numerical processing. The current results provide causal evidence for the functional relevance of right, but not left, parietal cortex for intentional, and automatic numerical processing, implying that at least within the parietal cortices, automatic, and intentional numerical processing rely on the same underlying hemispheric lateralization. PMID:22347175

Phosphorus sources (P plus filter pie with or without azotofos on the available P in the soil

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Maikel Abreu Jiménez

2014-04-01

Full Text Available The objective of the investigation was to evaluate the effect of four phosphorus sources plus filter pie with or without the biofertilizer Azotofos on the available phosphorus in the soil at different moments after the treatment. An experiment in factorial design 4(2+1 was established, being the four phosphorus sources: rock phosphate, natural phosphate, triple phosphate and Cuban phosphoric rock; two sources of the organic compound to base filter cake enriched with Azotofos microorganisms, only filter cake (without enrichment and a control treatment (without filter pie, neither Azotofos, with three repetitions. The evaluations of the tenor of available P (Bray-2 were carried out at the 30, 60, 90, 120 and 150 days after the installation of the experiment. The tenor of P (Bray-2 was influenced by the sources of P and the enrichment with biofertilizantes (factorial increasing the tenor of available P in front of the control. The triple superphosphate promoted the higher tenors in P in the soil at 60 and 90 days after its application, independently of the presence or not of the organic compound enriched with P solubilizing microorganisms, although this effect didn’t stay stable at the time.

Tracing the origin of glomerular extracapillary lesions from parietal epithelial cells.

NARCIS (Netherlands)

Smeets, B.; Uhlig, S.; Fuss, A.; Mooren, F.; Wetzels, J.F.M.; Floege, J.; Moeller, M.J.

2009-01-01

Cellular lesions form in Bowman's space in both crescentic glomerulonephritis and collapsing glomerulopathy. The pathomechanism and origin of the proliferating cells in these lesions are unknown. In this study, we examined proliferating cells by lineage tracing of either podocytes or parietal

The role of frontal and parietal brain areas in bistable perception

NARCIS (Netherlands)

Knapen, T.; Brascamp, J.; Pearson, J.; van Ee, R.; Blake, R.

2011-01-01

When sensory input allows for multiple, competing perceptual interpretations, observers' perception can fluctuate over time, which is called bistable perception. Imaging studies in humans have revealed transient responses in a right-lateralized network in the frontal-parietal cortex (rFPC) around

Electron-impact excitation of atomic-argon 3p54s-3p55p spectral transitions

International Nuclear Information System (INIS)

Bogdanova, I.P.; Yurgenson, S.V.

1990-01-01

Cross sections of excitation of some spectral lines of argon corresponding to transitions from 3p 5 5p-levels are measured using a pulsed electron beam. Cross sections of level excitation are estimated. It is shown that in transition from 3p 5 4p-levels to 3p 5 5p-levels, the cross section of levels by means of the electron impact decreases 20 times

Potential role of monkey inferior parietal neurons coding action semantic equivalences as precursors of parts of speech.

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Yamazaki, Yumiko; Yokochi, Hiroko; Tanaka, Michio; Okanoya, Kazuo; Iriki, Atsushi

2010-01-01

The anterior portion of the inferior parietal cortex possesses comprehensive representations of actions embedded in behavioural contexts. Mirror neurons, which respond to both self-executed and observed actions, exist in this brain region in addition to those originally found in the premotor cortex. We found that parietal mirror neurons responded differentially to identical actions embedded in different contexts. Another type of parietal mirror neuron represents an inverse and complementary property of responding equally to dissimilar actions made by itself and others for an identical purpose. Here, we propose a hypothesis that these sets of inferior parietal neurons constitute a neural basis for encoding the semantic equivalence of various actions across different agents and contexts. The neurons have mirror neuron properties, and they encoded generalization of agents, differentiation of outcomes, and categorization of actions that led to common functions. By integrating the activities of these mirror neurons with various codings, we further suggest that in the ancestral primates' brains, these various representations of meaningful action led to the gradual establishment of equivalence relations among the different types of actions, by sharing common action semantics. Such differential codings of the components of actions might represent precursors to the parts of protolanguage, such as gestural communication, which are shared among various members of a society. Finally, we suggest that the inferior parietal cortex serves as an interface between this action semantics system and other higher semantic systems, through common structures of action representation that mimic language syntax.

Right parietal cortex mediates recognition memory for melodies.

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Schaal, Nora K; Javadi, Amir-Homayoun; Halpern, Andrea R; Pollok, Bettina; Banissy, Michael J

2015-07-01

Functional brain imaging studies have highlighted the significance of right-lateralized temporal, frontal and parietal brain areas for memory for melodies. The present study investigated the involvement of bilateral posterior parietal cortices (PPCs) for the recognition memory of melodies using transcranial direct current stimulation (tDCS). Participants performed a recognition task before and after tDCS. The task included an encoding phase (12 melodies), a retention period, as well as a recognition phase (24 melodies). Experiment 1 revealed that anodal tDCS over the right PPC led to a deterioration of overall memory performance compared with sham. Experiment 2 confirmed the results of Experiment 1 and further showed that anodal tDCS over the left PPC did not show a modulatory effect on memory task performance, indicating a right lateralization for musical memory. Furthermore, both experiments revealed that the decline in memory for melodies can be traced back to an interference of anodal stimulation on the recollection process (remember judgements) rather than to familiarity judgements. Taken together, this study revealed a causal involvement of the right PPC for memory for melodies and demonstrated a key role for this brain region in the recollection process of the memory task. © 2015 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Causality in the association between P300 and alpha event-related desynchronization.

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Weiwei Peng

Full Text Available Recent findings indicated that both P300 and alpha event-related desynchronization (α-ERD were associated, and similarly involved in cognitive brain functioning, e.g., attention allocation and memory updating. However, an explicit causal influence between the neural generators of P300 and α-ERD has not yet been investigated. In the present study, using an oddball task paradigm, we assessed the task effect (target vs. non-target on P300 and α-ERD elicited by stimuli of four sensory modalities, i.e., audition, vision, somatosensory, and pain, estimated their respective neural generators, and investigated the information flow among their neural generators using time-varying effective connectivity in the target condition. Across sensory modalities, the scalp topographies of P300 and α-ERD were similar and respectively maximal at parietal and occipital regions in the target condition. Source analysis revealed that P300 and α-ERD were mainly generated from posterior cingulate cortex and occipital lobe respectively. As revealed by time-varying effective connectivity, the cortical information was consistently flowed from α-ERD sources to P300 sources in the target condition for all four sensory modalities. All these findings showed that P300 in the target condition is modulated by the changes of α-ERD, which would be useful to explore neural mechanism of cognitive information processing in the human brain.

Parietal theta burst TMS: Functional fractionation observed during bistable perception not evident in attention tasks.

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Schauer, Georg; Kanai, Ryota; Brascamp, Jan W

2016-02-01

When visual input is ambiguous, perception spontaneously alternates between interpretations: bistable perception. Studies have identified two distinct sites near the right intraparietal sulcus where inhibitory transcranial magnetic stimulation (TMS) affects the frequency of occurrence of these alternations, but strikingly with opposite directions of effect for the two sites. Lesion and TMS studies on spatial and sustained attention have also indicated a parcellation of right parietal cortex, into areas serving distinct attentional functions. We used the exact TMS procedure previously employed to affect bistable perception, yet measured its effect on spatial and sustained attention tasks. Although there was a trend for TMS to affect performance, trends were consistently similar for both parietal sites, with no indication of opposite effects. We interpret this as signifying that the previously observed parietal fractionation of function regarding the perception of ambiguous stimuli is not due to TMS-induced modification of spatial or sustained attention. Copyright © 2016 Elsevier Inc. All rights reserved.

Transcriptional landscape of glomerular parietal epithelial cells.

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Sina A Gharib

Full Text Available Very little is known about the function of glomerular parietal epithelial cells (PECs. In this study, we performed genome-wide expression analysis on PEC-enriched capsulated vs. PEC-deprived decapsulated rat glomeruli to determine the transcriptional state of PECs under normal conditions. We identified hundreds of differentially expressed genes that mapped to distinct biologic modules including development, tight junction, ion transport, and metabolic processes. Since developmental programs were highly enriched in PECs, we characterized several of their candidate members at the protein level. Collectively, our findings confirm that PECs are multifaceted cells and help define their diverse functional repertoire.

Interlaminar differences in the pyramidal cell phenotype in parietal cortex of an Indian bat, cynopterus sphinx.

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Srivastava, U C; Pathak, S V

2010-10-30

To study interlaminar phenotypic variations in the pyramidal neurons of parietal isocortex in bat (Cynopterus sphinx), Golgi and Nissl methods have been employed. The parietal isocortex is relatively thin in the bat as compared to prototheria with layer III, V and VI accounting for more than two—thirds of total cortical thickness. Thick cell free layer I and thinnest accentuated layer II are quite in connotation with other chiropterids. Poor demarcation of layer III/IV in the present study is also in connotation with primitive eutherian mammal (i.e. prototherian) and other chiropterids. Most of the pyramidal cells in the different layers of the parietal isocortex are of typical type as seen in other eutherians but differ significantly in terms of soma shape and size, extent of dendritic arbor, diameter of dendrites and spine density. Percentage of pyramidal neurons, diameter of apical dendrite and spine density on apical dendrite appear to follow an increasing trend from primitive to advanced mammals; but extent of dendrites are probably governed by the specific life patterns of these mammals. It is thus concluded that 'typical' pyramidal neurons in parietal isocortex are similar in therians but different from those in prototherians. It is possible that these cells might have arisen among early eutherians after divergence from prototherian stock.

The P-3 Scheduling Support System (P-3 S 3³)

OpenAIRE

Anderson, William B.

1988-01-01

Approved for public release; distribution is unlimited. A P-3 Scheduling Support System (P-3 S³ ) is a Management Information System (MIS) that was designed using structured techniques. Structured analysis was used to determine the functionality and data requirements. Computer Assisted Systems Engineering (CASE) tools were used to document the analysis and design. The system was designed to be implemented in dBase III Plus, a data base management tool developed by A...

EEG source reconstruction reveals frontal-parietal dynamics of spatial conflict processing

NARCIS (Netherlands)

Cohen, M.X.; Ridderinkhof, K.R.

2013-01-01

Cognitive control requires the suppression of distracting information in order to focus on task-relevant information. We applied EEG source reconstruction via time-frequency linear constrained minimum variance beamforming to help elucidate the neural mechanisms involved in spatial conflict

Controlling composition and color characteristics of Monascus pigments by pH and nitrogen sources in submerged fermentation.

Science.gov (United States)

Shi, Kan; Song, Da; Chen, Gong; Pistolozzi, Marco; Wu, Zhenqiang; Quan, Lei

2015-08-01

Submerged fermentations of Monascus anka were performed with different nitrogen sources at different pH in 3 L bioreactors. The results revealed that the Monascus pigments dominated by different color components (yellow pigments, orange pigments or red pigments) could be selectively produced through pH control and nitrogen source selection. A large amount of intracellular pigments dominated by orange pigments and a small amount of water-soluble extracellular yellow pigments were produced at low pH (pH 2.5 and 4.0), independently of the nitrogen source employed. At higher pH (pH 6.5), the role of the nitrogen source became more significant. In particular, when ammonium sulfate was used as nitrogen source, the intracellular pigments were dominated by red pigments with a small amount of yellow pigments. Conversely, when peptone was used, intracellular pigments were dominated by yellow pigments with a few red pigments derivatives. Neither the presence of peptone nor ammonium sulfate promoted the production of intracellular orange pigments while extracellular pigments with an orangish red color were observed in both cases, with a higher yield when peptone was used. Two-stage pH control fermentation was then performed to improve desirable pigments yield and further investigate the effect of pH and nitrogen sources on pigments composition. These results provide a useful strategy to produce Monascus pigments with different composition and different color characteristics. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Fronto-parietal contributions to phonological processes in successful artificial grammar learning

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Dariya Goranskaya

2016-11-01

Full Text Available Sensitivity to regularities plays a crucial role in the acquisition of various linguistic features from spoken language input. Artificial grammar (AG learning paradigms explore pattern recognition abilities in a set of structured sequences (i.e. of syllables or letters. In the present study, we investigated the functional underpinnings of learning phonological regularities in auditorily presented syllable sequences. While previous neuroimaging studies either focused on functional differences between the processing of correct vs. incorrect sequences or between different levels of sequence complexity, here the focus is on the neural foundation of the actual learning success. During functional magnetic resonance imaging (fMRI, participants were exposed to a set of syllable sequences with an underlying phonological rule system, known to ensure performance differences between participants. We expected that successful learning and rule application would require phonological segmentation and phoneme comparison. As an outcome of four alternating learning and test fMRI sessions, participants split into successful learners and non-learners. Relative to non-learners, successful learners showed increased task-related activity in a fronto-parietal network of brain areas encompassing the left lateral premotor cortex as well as bilateral superior and inferior parietal cortices during both learning and rule application. These areas were previously associated with phonological segmentation, phoneme comparison and verbal working memory. Based on these activity patterns and the phonological strategies for rule acquisition and application, we argue that successful learning and processing of complex phonological rules in our paradigm is mediated via a fronto-parietal network for phonological processes.

Body-centred map in parietal eye fields - functional MRI study

International Nuclear Information System (INIS)

Brotchie, P.; Chen, D.Y.; Bradley, W.G.

2002-01-01

Full text: In order for us to interact with our environment we need to know where objects are around us, relative to our body. In monkeys, a body-centred map of visual space is known to exist within the parietal eye fields. This map is formed by the modulation of neuronal activity by eye and head position (Brotchie et al, Nature 1995; Synder et al, Nature 1998). In humans no map of body centred space has been demonstrated. By using functional MRI we have localised a region along the intraparietal sulcus which has properties similar to the parietal eye fields of monkeys (Brotchie et al, ISMRM, 2000). The aim of this study was to determine if activity in this region is modulated by head position, consistent with a body centered representation of visual space. Functional MRI was performed on 6 subjects performing simple visually guided saccades using a 1.5 Tesla GE Echospeed scanner. 10 scans were performed on the 6 subjects at left and right body orientations. Regions of interest were selected around the intraparietal sulcus proper (IPSP) of both hemispheres and voxels with BOLD signal which correlated with the paradigm (r>0.35) were selected for further analysis. Comparisons of percentage signal change were made between the left and right IPSP using Student t test. Of the 10 MRI examinations, 6 demonstrated statistically significant differences in the amount of signal change between left and right IPSP. In each of these 6 cases, the signal change was greater within the IPSP contralateral to the direction of head position relative to the body. This indicates a modulation of activity within the IPSP related to head position, most likely reflecting modulation of the underlying neuronal activity and suggests the existence of a body-centred encoding of space within the parietal eye fields of humans. Copyright (2002) Blackwell Science Pty Ltd

Temporo-Parietal and Fronto-Parietal Lobe Contributions to Theory of Mind and Executive Control: An fMRI Study of Verbal Jokes

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Yu-Chen eChan

2015-09-01

Full Text Available ‘Getting a joke’ always requires resolving an apparent incongruity but the particular cognitive operations called upon vary depending on the nature of the joke itself. Previous research has identified the primary neural correlates of the cognitive and affective processes called upon to respond to humor generally, but little work has been done on the substrates underlying the distinct cognitive operations required to comprehend particular joke types. This study explored the neural correlates of the cognitive processes required to successfully comprehend three joke types: bridging-inference jokes, exaggeration jokes and ambiguity jokes. For all joke types, the left dlPFC appeared to support common cognitive mechanisms, such as script-shifting, while the vACC was associated with affective appreciation. The temporo-parietal lobe (TPJ and MTG was associated with bridging-inference jokes, suggesting involvement of these regions with ‘theory of mind’ processing. The ventral fronto-parietal lobe (IPL and IFG was associated with both exaggeration and ambiguity jokes, suggesting that it supports executive control processes such as retrieval from episodic memory, self-awareness, and language-based decoding. The social-affective appreciation of verbal jokes was associated with activity in the orbitofrontal cortex, amygdala, ventral anterior cingulate cortex (vACC, and parahippocampal gyrus. These results allow a more precise account of the neural

Study of source size in p bar p collisions at √s =1.8 TeV using pion interferometry

International Nuclear Information System (INIS)

Alexopoulos, T.; Allen, C.; Anderson, E.W.; Balamurali, V.; Banerjee, S.; Beery, P.D.; Bhat, P.; Bishop, J.M.; Biswas, N.N.; Bujak, A.; Carmony, D.D.; Carter, T.; Choi, Y.; Cole, P.; DeBonte, R.; DeCarlo, V.; Erwin, A.R.; Findeisen, C.; Goshaw, A.T.; Gutay, L.J.; Hirsch, A.S.; Hojvat, C.; Jennings, J.R.; Kenney, V.P.; Lindsey, C.S.; Loomis, C.; LoSecco, J.M.; McMahon, T.; McManus, A.P.; Morgan, N.K.; Nelson, K.; Oh, S.H.; Porile, N.T.; Reeves, D.; Rimai, A.; Robertson, W.R.; Scharenberg, R.P.; Stampke, S.R.; Stringfellow, B.C.; Thompson, M.A.; Turkot, F.; Walker, W.D.; Wang, C.H.; Warchol, J.; Wesson, D.K.; Zhan, Y.H.

1993-01-01

Experiment E735 collected data for ∼10 7 interactions at the C0 intersection of the Fermilab p bar p collider with √s =1.8 TeV. The Bose-Einstein correlations between pairs of identical pions were measured in a limited aperture spectrometer and used to estimate the size and lifetime of the source. The aperture shape limited the sensitivity primarily to the source dimension R along the incident p bar p direction. Both this dimension and the lifetime appear to depend strongly on pion multiplicity. Efforts were also made to obtain some information on the transverse source size, energy density, and the dependence of source size and strength on dipion momentum. Fits to the entire data sample yielded a value R=1.06±0.07 fm for the average source dimension and a value τ=0.74±0.06 fm for the average source lifetime with left-angle dN c /dη right-angle=14.4

Parietal intradiploic encephalocele: Report of a case and review of the literature.

Science.gov (United States)

Arevalo-Perez, Julio; Millán-Juncos, José M

2015-06-01

Encephaloceles consist of brain tissue and meninges that has herniated through a skull defect, usually located in the midline. They are seen more commonly in children and very rarely in adults. We present a case of an 84-year-old patient who was incidentally diagnosed with a lytic bone lesion in the right parietal intradiploic space, after computed tomography of the head was performed. A magnetic resonance imaging scan of the brain showed herniation of brain tissue through the defect. Magnetic resonance imaging was crucial in demonstrating the presence of parenchyma and its continuity with the rest of the brain, consequently distinguishing it from other entities. We report the imaging findings of a parietal indradiploic encephalocele with its differential diagnosis and a review of the relevant literature. © The Author(s) 2015.

Reactions of R(2)P-P(SiMe(3))Li with [(R'(3)P)(2)PtCl(2)]. A general and efficient entry to phosphanylphosphinidene complexes of platinum. Syntheses and structures of [(eta(2)-P=(i)Pr(2))Pt(p-Tol(3)P)(2)], [(eta(2)-P=(t)Bu(2))Pt(p-Tol(3)P)(2)], [{eta(2)-P=(N(i)Pr(2))(2)}Pt(p-Tol(3)P)(2)] and [{(Et(2)PhP)(2)Pt}(2)P(2)].

Science.gov (United States)

Domańska-Babul, Wioleta; Chojnacki, Jaroslaw; Matern, Eberhard; Pikies, Jerzy

2009-01-07

The reactions of lithium derivatives of diphosphanes R(2)P-P(SiMe(3))Li (R = (t)Bu, (i)Pr, Et(2)N and (i)Pr(2)N) with [(R'(3)P)(2)PtCl(2)] (R'(3)P = Et(3)P, Et(2)PhP, EtPh(2)P and p-Tol(3)P) proceed in a facile manner to afford side-on bonded phosphanylphosphinidene complexes of platinum [(eta(2)-P=R(2))Pt(PR'(3))(2)]. The related reactions of Ph(2)P-P(SiMe(3))Li with [(R'(3)P)(2)PtCl(2)] did not yield [(eta(2)-P=PPh(2))Pt(PR'(3))(2)] and resulted mainly in the formation of [{(R'(3)P)(2)Pt}(2)P(2)], Ph(2)P-PLi-PPh(2), (Me(3)Si)(2)PLi and (Me(3)Si)(3)P. Crystallographic data are reported for the compounds [(eta(2)-P=R(2))Pt(p-Tol(3)P)(2)] (R = (t)Bu, (i)Pr, ((i)Pr(2)N)(2)P) and for [{(Et(2)PhP)(2)Pt}(2)P(2)].

El contexto del arte parietal. La tecnología de los artistas en la Cueva de Tito Bustillo (Asturias

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Moure Romanillo, Alfonso

1988-12-01

Full Text Available This study overlaps in part with a communication presented to the «Colloque International d'Art Parietal Paléolithique» held at Perigueux-Le Thot in december 1984. The technological responses contained in a decorated zone of the cave of Tito Bustillo are analyzed, as well as the activities carried out on living floors related to the preparation and completion of the parietal art.

El trabajo coincide parcialmente con la comunicación presentada al «Colloque International d'Art Parietal Paléolithique» celebrado en Perigueux-Le Thot, en diciembre de 1984. Se analizan las respuestas tecnológicas contenidas en un área de decoración de la cueva de Tito Bustillo (Asturias, así como las actividades en áreas de estancia relacionadas con la preparación y ejecución del arte parietal.

Estudos sobre thrombose cardiaca e endocardite parietal de origem não valvular On thrombosis of heart and on mural endocarditis of non-valvular origin

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C. Magarinos Torres

1928-01-01

Full Text Available 1.-Since the parietal endocarditis represents a chapter generally neglected, owing to the relative lack of cases, and somewhat confused because there various terms have been applied to a very same morbid condition, it justifies the work which previously we tried to accomplish, of nosographic classification. Taking into account the functional disturbances and the anatomical changes, all cases of parietal endocarditis referred to in the litterature were distributed by the following groups: A-Group-Valvulo-parietal endocarditis. 1st . type-Valvulo-parietal endocarditis per continuum. 2nd. type-Metastatic valvulo-parietal endocarditis. 3rd. type-Valvulo-parietal endocarditis of the mitral stenosis. B-Group-Genuine parietal endocarditis. a with primary lesions in the myocardium. b with primary lesions in the endocardium. 4th type-Fibrous chronic parietal endocarditis (B A Ü M L E R, « endocarditis parietalis simplex». 5th type-Septic acute parietal endocarditis (LESCHKE, «endocarditis parietalis septica». 6th type-Subacute parietal endocarditis (MAGARINOS TORRES, «endocarditis muralis lenta». 2.-Studying a group of 14 cases of fibrous endomyocarditis with formation of thrombi, and carrying together pathological and bacteriological examinations it has been found that some of such cases represent an infectious parietal endocarditis, sometimes post-puerperal, of subacute or slow course, the endocardic vegetations being contamined by pathogenic microörganisms of which the most frequent is the Diplococcus pneumoniae, in most cases of attenuated virulence. Along with the infectious parietal endocarditis, there occur arterial and venous thromboses (abdominal aorta, common illiac and femural arteries and external jugular veins. The case 5,120 is a typical one of this condition which we name subacute parietal endocarditis (endocarditis parietalis s. muralis lenta. 3.-The endocarditis muralis lenta encloses an affection reputed to be of rare occurrence

Recent advances in acceleration of source iterations for fixed-source slab-geometry S{sub N} calculations based on P{sub N} synthetic initial guess

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Guida, Mateus Rodrigues; Alves Filho, Hermes; Barros, Ricardo C., E-mail: mguida@iprj.uerj.br, E-mail: halves@iprj.uerj.br, E-mail: rcbarros@pq.cnpq.br [Universidade do Estado do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil). Instituto Politecnico. Programa de Pos-Graduacao em Modelagem Computacional

2015-07-01

The scattering source iterative (SI) scheme is applied traditionally to converge fine-mesh numerical solutions to fixed-source discrete ordinates (S{sub N}) neutron transport problems with linearly anisotropic scattering. The SI scheme is very simple to implement under a computational viewpoint. However, the SI scheme may show very slow convergence rate, mainly for diffusive media (low absorption) with several mean free paths in extent. In this work we describe two acceleration techniques based on improved initial guesses for the SI scheme, wherein we initialize the scattering source distribution within the slab using the P{sub 1} and P{sub 3} approximations. In order to estimate these initial guesses, we use the coarse-mesh solution of the PN equations with special boundary conditions to account for the classical S{sub N} prescribed boundary conditions, including vacuum boundary conditions. To apply this coarse-mesh P{sub N} solution for the accelerated scheme, we first perform within-node spatial reconstruction, and then we determine the fine-mesh average scalar flux and total current for initializing the linearly anisotropic scattering source terms for the SI scheme. We consider a number of numerical experiments to illustrate the efficiency of the offered P{sub N} synthetic acceleration (P{sub N}SA) technique based on initial guess. (author)

Synthesis of 32P labelled phosphate sources with different solubility and their efficient s as fertilizers

International Nuclear Information System (INIS)

De Luca, Edgar Fernando; Boaretto, Antonio Enedi; Muraoka, Takashi

1999-01-01

The study was carried out at the Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo (CENA/USP), Brazil. With the objective to determine, by the isotopic tracer, the P recovery by rice (Oriza sativa) plants and eucalypt (Eucalyptus grandis) seedlings from the P sources with different solubilities, an experiment was carried out in greenhouse, using Quartzpsamment soil samples, which is very poor in P content. Monocalcium, bicalcium, and tricalcium phosphate, Ca(H2 32 PO4).H2O, CaH 32 PO4.2H2O and Ca3(32 PO4)2, respectively were obtained in laboratory. Their solubilities and the X-ray difratometry and differential thermal analysis comproved that the laboratory procedures were adequate for obtaining the desired compounds. These products were applied in the soil as fertilizers. Plants were harvested 60 days after growth period, digested and analysed for total P and 32 P counting through Cerenkov effect. The P recovery from the sources varied from 14.1% [Ca(H2 32 PO4).H2O] to 17.0% [CaH 32 PO4.2H2O] for eucalypt, and from 15.0% [Ca3(32 PO4)2] to 22.2% [CaH 32 PO4.2H2O] for rice. The rice plants showed better ability to absorb P from the laboratory prepared sources, but the eucalypt presented higher P nutritional efficiency index. The difference method, used for determining the P recovery, underestimated the eucalypt and rice plant ability to absorb this nutrient compared to the isotopic method

Electron Excitation Cross Sections for the S II Transitions: 3s(exp 2)3p(exp 3) 4S(exp o) approaches 3s(exp 2)3p(exp 3) 2D(exp o), 2P(exp o), and 3s3p(exp 4) 4P

Science.gov (United States)

Liao, C.; Chutjian, A.; Hitz, D.; Tayal, S. S.

1997-01-01

Experimental and theoretical collisional excitation cross sections are reported for the transitions 3s(exp 2)3p(exp 3)4S(exp o) approaches 3s(exp 2)3p(exp 3) 2D(exp o), 2P(exp o), and 3s3P(exp 4) 4P in S II. The transition wavelengths (energies) are 6716 A (1.85 eV), 4069 A (3.05 eV), and 1256 A (9.87 eV), respectively. In the experiments, use is made of the energy-loss merged-beams method. The metastable fraction of the S II beam was assessed and minimized. The contribution of elastically scattered electrons was reduced by the use of a lowered solenoidal magnetic field and a modulated radio-frequency voltage on the analyzing plates and by retarding grids to reject the elastically scattered electrons with larger Larmor radii. For each transition, comparisons are made among experiments, the new 19 state R-matrix calculation, and three other close-coupling calculations.

The impact of top-down spatial attention on laterality and hemispheric asymmetry in the human parietal cortex.

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Jeong, Su Keun; Xu, Yaoda

2016-08-01

The human parietal cortex exhibits a preference to contralaterally presented visual stimuli (i.e., laterality) as well as an asymmetry between the two hemispheres with the left parietal cortex showing greater laterality than the right. Using visual short-term memory and perceptual tasks and varying target location predictability, this study examined whether hemispheric laterality and asymmetry are fixed characteristics of the human parietal cortex or whether they are dynamic and modulated by the deployment of top-down attention to the target present hemifield. Two parietal regions were examined here that have previously been shown to be involved in visual object individuation and identification and are located in the inferior and superior intraparietal sulcus (IPS), respectively. Across three experiments, significant laterality was found in both parietal regions regardless of attentional modulation with laterality being greater in the inferior than superior IPS, consistent with their roles in object individuation and identification, respectively. Although the deployment of top-down attention had no effect on the superior IPS, it significantly increased laterality in the inferior IPS. The deployment of top-down spatial attention can thus amplify the strength of laterality in the inferior IPS. Hemispheric asymmetry, on the other hand, was absent in both brain regions and only emerged in the inferior but not the superior IPS with the deployment of top-down attention. Interestingly, the strength of hemispheric asymmetry significantly correlated with the strength of laterality in the inferior IPS. Hemispheric asymmetry thus seems to only emerge when there is a sufficient amount of laterality present in a brain region.

Laser annealed in-situ P-doped Ge for on-chip laser source applications (Conference Presentation)

Science.gov (United States)

Srinivasan, Ashwyn; Pantouvaki, Marianna; Shimura, Yosuke; Porret, Clement; Van Deun, Rik; Loo, Roger; Van Thourhout, Dries; Van Campenhout, Joris

2016-05-01

Realization of a monolithically integrated on-chip laser source remains the holy-grail of Silicon Photonics. Germanium (Ge) is a promising semiconductor for lasing applications when highly doped with Phosphorous (P) and or alloyed with Sn [1, 2]. P doping makes Ge a pseudo-direct band gap material and the emitted wavelengths are compatible with fiber-optic communication applications. However, in-situ P doping with Ge2H6 precursor allows a maximum active P concentration of 6×1019 cm-3 [3]. Even with such active P levels, n++ Ge is still an indirect band gap material and could result in very high threshold current densities. In this work, we demonstrate P-doped Ge layers with active n-type doping beyond 1020 cm-3, grown using Ge2H6 and PH3 and subsequently laser annealed, targeting power-efficient on-chip laser sources. The use of Ge2H6 precursors during the growth of P-doped Ge increases the active P concentration level to a record fully activated concentration of 1.3×1020 cm-3 when laser annealed with a fluence of 1.2 J/cm2. The material stack consisted of 200 nm thick P-doped Ge grown on an annealed 1 µm Ge buffer on Si. Ge:P epitaxy was performed with PH3 and Ge2H6 at 320oC. Low temperature growth enable Ge:P epitaxy far from thermodynamic equilibrium, resulting in an enhanced incorporation of P atoms [3]. At such high active P concentration, the n++ Ge layer is expected to be a pseudo-direct band gap material. The photoluminescence (PL) intensities for layers with highest active P concentration show an enhancement of 18× when compared to undoped Ge grown on Si as shown in Fig. 1 and Fig. 2. The layers were optically pumped with a 640 nm laser and an incident intensity of 410 mW/cm2. The PL was measured with a NIR spectrometer with a Hamamatsu R5509-72 NIR photomultiplier tube detector whose detectivity drops at 1620 nm. Due to high active P concentration, we expect band gap narrowing phenomena to push the PL peak to wavelengths beyond the detection limit

Surface Reconstruction from Parallel Curves with Application to Parietal Bone Fracture Reconstruction.

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Abdul Majeed

Full Text Available Maxillofacial trauma are common, secondary to road traffic accident, sports injury, falls and require sophisticated radiological imaging to precisely diagnose. A direct surgical reconstruction is complex and require clinical expertise. Bio-modelling helps in reconstructing surface model from 2D contours. In this manuscript we have constructed the 3D surface using 2D Computerized Tomography (CT scan contours. The fracture part of the cranial vault are reconstructed using GC1 rational cubic Ball curve with three free parameters, later the 2D contours are flipped into 3D with equidistant z component. The constructed surface is represented by contours blending interpolant. At the end of this manuscript a case report of parietal bone fracture is also illustrated by employing this method with a Graphical User Interface (GUI illustration.

P-protein distribution in mature sieve elements of Cucurbita maxima.

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Evert, R F; Eschrich, W; Eichhorn, S E

1972-09-01

Portions of the hypocotyls of 16-day-old Cucurbita maxima plants, from which the cotyledons and first foliage leaves had been removed 2 days earlier, were fixed in glutaraldehyde and postfixed in osmium tetroxide for electron microscopy. In well over 90% of the mature sieve elements examined the P-protein was entirely parietal in distribution in both the lumina and sieve-plate pores. In addition to the parietal P-protein, the unoccluded sieve-plate pores were lined by narrow callose cylinders and the plasmalemma. Segments of endoplasmic reticulum also occurred along the margins of the pores.

InGaAsP/InP-air-aperture microcavities for single-photon sources at 1.55-μm telecommunication band

Science.gov (United States)

Guo, Sijie; Zheng, Yanzhen; Weng, Zhuo; Yao, Haicheng; Ju, Yuhao; Zhang, Lei; Ren, Zhilei; Gao, Ruoyao; Wang, Zhiming M.; Song, Hai-Zhi

2016-11-01

InGaAsP/InP-air-aperture micropillar cavities are proposed to serve as 1.55-μm single photon sources, which are indispensable in silica-fiber based quantum information processing. Owing to air-apertures introduced to InP layers, and adiabatically tapered distributed Bragg-reflector structures used in the central cavity layers, the pillar diameters can be less than 1 μm, achieving mode volume as small as (λ/n)3, and the quality factors are more than 104 - 105, sufficient to increase the quantum dot emission rate for 100 times and create strong coupling between the optical mode and the 1.55- μm InAs/InP quantum dot emitter. The mode wavelengths and quality factors are found weakly changing with the cavity size and the deviation from the ideal shape, indicating the robustness against the imperfection of the fabrication technique. The fabrication, simply epitaxial growth, dry and chemical etching, is a damage-free and monolithic process, which is advantageous over previous hybrid cavities. The above properties satisfy the requirements of efficient, photonindistinguishable and coherent 1.55-μm quantum dot single photon sources, so the proposed InGaAsP/InP-air-aperture micropillar cavities are prospective candidates for quantum information devices at telecommunication band.

The organization of the posterior parietal cortex devoted to upper limb actions: An fMRI study

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Ferri, Stefania; Rizzolatti, Giacomo

2015-01-01

Abstract The present fMRI study examined whether upper‐limb action classes differing in their motor goal are encoded by different PPC sectors. Action observation was used as a proxy for action execution. Subjects viewed actors performing object‐related (e.g., grasping), skin‐displacing (e.g., rubbing the skin), and interpersonal upper limb actions (e.g., pushing someone). Observation of the three action classes activated a three‐level network including occipito‐temporal, parietal, and premotor cortex. The parietal region common to observing all three action classes was located dorsally to the left intraparietal sulcus (DIPSM/DIPSA border). Regions specific for observing an action class were obtained by combining the interaction between observing action classes and stimulus types with exclusive masking for observing the other classes, while for regions considered preferentially active for a class the interaction was exclusively masked with the regions common to all observed actions. Left putative human anterior intraparietal was specific for observing manipulative actions, and left parietal operculum including putative human SII region, specific for observing skin‐displacing actions. Control experiments demonstrated that this latter activation depended on seeing the skin being moved and not simply on seeing touch. Psychophysiological interactions showed that the two specific parietal regions had similar connectivities. Finally, observing interpersonal actions preferentially activated a dorsal sector of left DIPSA, possibly the homologue of ventral intraparietal coding the impingement of the target person's body into the peripersonal space of the actor. These results support the importance of segregation according to the action class as principle of posterior parietal cortex organization for action observation and by implication for action execution. Hum Brain Mapp 36:3845–3866, 2015. © 2015 The Authors Human Brain Mapping Published by Wiley

Sustained attention is associated with right superior longitudinal fasciculus and superior parietal white matter microstructure in children

DEFF Research Database (Denmark)

Klarborg, Brith; Skak Madsen, Kathrine; Vestergaard, Martin

2013-01-01

Sustained attention develops during childhood and has been linked to the right fronto-parietal cortices in functional imaging studies; however, less is known about its relation to white matter (WM) characteristics. Here we investigated whether the microstructure of the WM underlying and connecting...... the right fronto-parietal cortices was associated with sustained attention performance in a group of 76 typically developing children aged 7-13 years. Sustained attention was assessed using a rapid visual information processing paradigm. The two behavioral measures of interest were the sensitivity index d......' and the coefficient of variation in reaction times (RT(CV) ). Diffusion-weighted imaging was performed. Mean fractional anisotropy (FA) was extracted from the WM underlying right dorsolateral prefrontal (DLPFC) and parietal cortex (PC), and the right superior longitudinal fasciculus (SLF), as well as equivalent...

Transition probabilities for the 3s2 3p(2P0)-3s3p2(4P) intersystem lines of Si II

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Calamai, Anthony G.; Smith, Peter L.; Bergeson, S. D.

1993-01-01

Intensity ratios of lines of the spin-changing 'intersystem' multiplet of S II (4P yields 2P0) at 234 nm have been used to determine electron densities and temperatures in a variety of astrophysical environments. However, the accuracy of these diagnostic calculations have been limited by uncertainties associated with the available atomic data. We report the first laboratory measurement, using an ion-trapping technique, of the radiative lifetimes of the three metastable levels of the 3s3p2 4P term of Si II. Our results are 104 +/- 16, 406 +/- 33, and 811 +/- 77 micro-s for lifetimes of the J = 1/2, 5/2, and 3/2 levels, respectively. A-values were derived from our lifetimes by use of measured branching fractions. Our A-values, which differ from calculated values by 30 percent or more, should give better agreement between modeled and observed Si II line ratios.

Meta-analysis: how does posterior parietal cortex contribute to reasoning?

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Wendelken, Carter

2015-01-01

Reasoning depends on the contribution of posterior parietal cortex (PPC). But PPC is involved in many basic operations—including spatial attention, mathematical cognition, working memory, long-term memory, and language—and the nature of its contribution to reasoning is unclear. Psychological theories of the processes underlying reasoning make divergent claims about the neural systems that are likely to be involved, and better understanding the specific contribution of PPC can help to inform these theories. We set out to address several competing hypotheses, concerning the role of PPC in reasoning: (1) reasoning involves application of formal logic and is dependent on language, with PPC activation for reasoning mainly reflective of linguistic processing; (2) reasoning involves probabilistic computation and is thus dependent on numerical processing mechanisms in PPC; and (3) reasoning is built upon the representation and processing of spatial relations, and PPC activation associated with reasoning reflects spatial processing. We conducted two separate meta-analyses. First, we pooled data from our own studies of reasoning in adults, and examined activation in PPC regions of interest (ROI). Second, we conducted an automated meta-analysis using Neurosynth, in which we examined overlap between activation maps associated with reasoning and maps associated with other key functions of PPC. In both analyses, we observed reasoning-related activation concentrated in the left Inferior Parietal Lobe (IPL). Reasoning maps demonstrated the greatest overlap with mathematical cognition. Maintenance, visuospatial, and phonological processing also demonstrated some overlap with reasoning, but a large portion of the reasoning map did not overlap with the map for any other function. This evidence suggests that the PPC’s contribution to reasoning may be most closely related to its role in mathematical cognition, but that a core component of this contribution may be specific to

Meta-analysis: How does posterior parietal cortex contribute to reasoning?

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Carter eWendelken

2015-01-01

Full Text Available Reasoning depends on the contribution of posterior parietal cortex (PPC. But PPC is involved in many basic operations -- including spatial attention, mathematical cognition, working memory, long-term memory, and language -- and the nature of its contribution to reasoning is unclear. Psychological theories of the processes underlying reasoning make divergent claims about the neural systems that are likely to be involved, and better understanding the specific contribution of PPC can help to inform these theories. We set out to address several competing hypotheses, concerning the role of PPC in reasoning: 1 reasoning involves application of formal logic and is dependent on language, with PPC activation for reasoning mainly reflective of linguistic processing, 2 reasoning involves probabilistic computation and is thus dependent on numerical processing mechanisms in PPC, and 3 reasoning is built upon the representation and processing of spatial relations, and PPC activation associated with reasoning reflects spatial processing. We conducted two separate meta-analyses. First, we pooled data from our own studies of reasoning in adults, and examined activation in PPC regions of interest. Second, we conducted an automated meta-analysis using Neurosynth, in which we examined overlap between activation maps associated with reasoning and maps associated with other key functions of PPC. In both analyses, we observed reasoning-related activation concentrated in the left Inferior Parietal Lobe (IPL. Reasoning maps demonstrated the greatest overlap with mathematical cognition. Maintenance, visuospatial, and phonological processing also demonstrated some overlap with reasoning, but a large portion of the reasoning map did not overlap with the map for any other function. This evidence suggests that the PPC’s contribution to reasoning may be most closely related to its role in mathematical cognition, but that a core component of this contribution may be specific

A micromethod for the assay of cellular secretory physiology: Application to rabbit parietal cells

International Nuclear Information System (INIS)

Adrian, T.E.; Goldenring, J.R.; Oddsdottir, M.; Zdon, M.J.; Zucker, K.A.; Lewis, J.J.; Modlin, I.M.

1989-01-01

A micromethod for investigating secretory physiology in isolated cells was evaluated. The method utilized a specially designed polycarbonate incubation chamber to provide constant oxygenation to cells incubating in a 96-well microtiter plate. Cells were rapidly separated from media by vacuum filtration. Isolated parietal cells were utilized to demonstrate the versatility of the method for assay of intracellular accumulation of [ 14 C]-aminopyrine, secretion of intrinsic factor into the medium, and assay of intracellular cAMP. Histamine stimulated the uptake of [ 14 C]aminopyrine and intrinsic factor secretion in a sustained and linear fashion. At the end of the 2-h period uptake of aminopyrine and secretion of intrinsic factor were increased 17- and 5-fold, respectively. This response to histamine was accompanied by a rapid and sustained 3-fold rise in intracellular cyclic AMP. In contrast, carbamylcholine caused a transient increase in [ 14 C]aminopyrine accumulation and intrinsic factor secretion which was most pronounced during the first 10 min and had almost ceased by 30 min. Carbamylcholine had no effect on intracellular cAMP levels. This new method, which can handle 400 replicates using parietal cells from the fundic mucosa of a single rabbit, is suitable for studying the time course of intracellular events which accompany general secretory processes

Caracterización del injerto parietal

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José Manuel Díaz Fernández

1996-12-01

Full Text Available Se realizó un estudio descriptivo, longitudinal y prospectivo de 22 pacientes en los que se utilizó el injerto parietal autógeno para reconstruir defectos del cráneo, en los servicios de Cirugía Maxilofacial y Neurocirugía del Hospital Clinicoquirúrgico Docente "Saturnino Lora", de Santiago de Cuba, desde 1988 hasta 1991. El método de extracción del injerto con división in situ resultó el más empleado y el que ofreció las mejores posibilidades de reconstrucción en cuanto a forma, volumen y flexibilidad, por lo que se recomienda en los defectos pequeños y medianos, sobre todo de la región frontal y áreas adyacentes, donde el contorno y la simetría son los 2 aspectos fundamentales que se deben conseguir. El método de división, in vitro se utilizó en las reconstrucciones de las deformidades de grandes dimensiones, particularmente en aquellas que no incluían la frente. El índice de complicaciones fue bajoIt was carried out a descriptive, longitudinal and prospective study of 22 patients in whom an autogenous parietal graft was used to reconstruct cranial defects at the Maxillofacial Surgery and Neurosurgery Department of the "Saturnino Lora" Clinical and Surgical Teaching Hospital, in Santiago de Cuba, from 1988 to 1991. The graft extraction method with division in situ was the most used and offered the best possibilities for reconstruction as regards form, volume and flexibility. Therefore, it is recommended for small and medium defects, particularly of the frontal region and adjacent areas, where contour and symmetry are the two fundamental aspects to be taken into consideration. The method of division in vitro was used to reconstruct large deformities, specially those in which the forehead was not included. The complications index was low

High-alpha band synchronization across frontal, parietal and visual cortex mediates behavioral and neuronal effects of visuospatial attention.

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Lobier, Muriel; Palva, J Matias; Palva, Satu

2018-01-15

Visuospatial attention prioritizes processing of attended visual stimuli. It is characterized by lateralized alpha-band (8-14 Hz) amplitude suppression in visual cortex and increased neuronal activity in a network of frontal and parietal areas. It has remained unknown what mechanisms coordinate neuronal processing among frontoparietal network and visual cortices and implement the attention-related modulations of alpha-band amplitudes and behavior. We investigated whether large-scale network synchronization could be such a mechanism. We recorded human cortical activity with magnetoencephalography (MEG) during a visuospatial attention task. We then identified the frequencies and anatomical networks of inter-areal phase synchronization from source localized MEG data. We found that visuospatial attention is associated with robust and sustained long-range synchronization of cortical oscillations exclusively in the high-alpha (10-14 Hz) frequency band. This synchronization connected frontal, parietal and visual regions and was observed concurrently with amplitude suppression of low-alpha (6-9 Hz) band oscillations in visual cortex. Furthermore, stronger high-alpha phase synchronization was associated with decreased reaction times to attended stimuli and larger suppression of alpha-band amplitudes. These results thus show that high-alpha band phase synchronization is functionally significant and could coordinate the neuronal communication underlying the implementation of visuospatial attention. Copyright © 2017 Elsevier Inc. All rights reserved.

Posterior parietal cortex and episodic encoding: insights from fMRI subsequent memory effects and dual-attention theory.

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Uncapher, Melina R; Wagner, Anthony D

2009-02-01

The formation of episodic memories--memories for life events--is affected by attention during event processing. A leading neurobiological model of attention posits two separate yet interacting systems that depend on distinct regions in lateral posterior parietal cortex (PPC). From this dual-attention perspective, dorsal PPC is thought to support the goal-directed allocation of attention, whereas ventral PPC is thought to support reflexive orienting to information that automatically captures attention. To advance understanding of how parietal mechanisms may impact event encoding, we review functional MRI studies that document the relationship between lateral PPC activation during encoding and subsequent memory performance (e.g., later remembering or forgetting). This review reveals that (a) encoding-related activity is frequently observed in human lateral PPC, (b) increased activation in dorsal PPC is associated with later memory success, and (c) increased activation in ventral PPC predominantly correlates with later memory failure. From a dual-attention perspective, these findings suggest that allocating goal-directed attention during event processing increases the probability that the event will be remembered later, whereas the capture of reflexive attention during event processing may have negative consequences for event encoding. The prevalence of encoding-related activation in parietal cortex suggests that neurobiological models of episodic memory should consider how parietal-mediated attentional mechanisms regulate encoding.

Controversies over the mechanisms underlying the crucial role of the left fronto-parietal areas in the representation of tools

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Guido eGainotti

2013-10-01

Full Text Available Anatomo-clinical and neuroimaging data show that the left fronto-parietal areas play an important role in representing tools. As manipulation is an important source of knowledge about tools, it has been assumed that motor activity explains the link between tool knowledge and the left fronto-parietal areas. However, controversies exist over the exact mechanisms underlying this relationship. According to a strong version of the ‘embodied cognition theory’, activation of a tool concept necessarily involves re-enactment of the corresponding kind of action. Impairment of the ability to use tools should, therefore, lead to impairment of tool knowledge. Both the ‘domains of knowledge hypothesis’ and the ‘sensory-motor model of conceptual knowledge’ refute the strong version of the ‘embodied cognition hypothesis’ but acknowledge that manipulation and other action schemata play an important role in our knowledge of tools. The basic difference between these two models is that the former is based on an innatist model and the latter holds that the brain’s organization of categories is experience dependent. Data supporting and arguing against each of these models are briefly reviewed. In particular, the following lines of research, which argue against the innate nature of the brain’s categorical organization, are discussed: (1 the observation that in patients with category-specific disorders the semantic impairment does not respect the boundaries between biological entities and artefact items; (2 data showing that experience-driven neuroplasticity in musicians is not confined to alterations of perceptual and motor maps but also leads to the establishment of higher-level semantic representations for musical instruments; (3 results of experiments using previously unfamiliar materials showing that the history of our sensory-motor experience with an object significantly affects its neural representation.

Frontal and parietal cortical interactions with distributed visual representations during selective attention and action selection.

Science.gov (United States)

Nelissen, Natalie; Stokes, Mark; Nobre, Anna C; Rushworth, Matthew F S

2013-10-16

Using multivoxel pattern analysis (MVPA), we studied how distributed visual representations in human occipitotemporal cortex are modulated by attention and link their modulation to concurrent activity in frontal and parietal cortex. We detected similar occipitotemporal patterns during a simple visuoperceptual task and an attention-to-working-memory task in which one or two stimuli were cued before being presented among other pictures. Pattern strength varied from highest to lowest when the stimulus was the exclusive focus of attention, a conjoint focus, and when it was potentially distracting. Although qualitatively similar effects were seen inside regions relatively specialized for the stimulus category and outside, the former were quantitatively stronger. By regressing occipitotemporal pattern strength against activity elsewhere in the brain, we identified frontal and parietal areas exerting top-down control over, or reading information out from, distributed patterns in occipitotemporal cortex. Their interactions with patterns inside regions relatively specialized for that stimulus category were higher than those with patterns outside those regions and varied in strength as a function of the attentional condition. One area, the frontal operculum, was distinguished by selectively interacting with occipitotemporal patterns only when they were the focus of attention. There was no evidence that any frontal or parietal area actively inhibited occipitotemporal representations even when they should be ignored and were suppressed. Using MVPA to decode information within these frontal and parietal areas showed that they contained information about attentional context and/or readout information from occipitotemporal cortex to guide behavior but that frontal regions lacked information about category identity.

Frontal and Parietal Cortical Interactions with Distributed Visual Representations during Selective Attention and Action Selection

Science.gov (United States)

Stokes, Mark; Nobre, Anna C.; Rushworth, Matthew F. S.

2013-01-01

Using multivoxel pattern analysis (MVPA), we studied how distributed visual representations in human occipitotemporal cortex are modulated by attention and link their modulation to concurrent activity in frontal and parietal cortex. We detected similar occipitotemporal patterns during a simple visuoperceptual task and an attention-to-working-memory task in which one or two stimuli were cued before being presented among other pictures. Pattern strength varied from highest to lowest when the stimulus was the exclusive focus of attention, a conjoint focus, and when it was potentially distracting. Although qualitatively similar effects were seen inside regions relatively specialized for the stimulus category and outside, the former were quantitatively stronger. By regressing occipitotemporal pattern strength against activity elsewhere in the brain, we identified frontal and parietal areas exerting top-down control over, or reading information out from, distributed patterns in occipitotemporal cortex. Their interactions with patterns inside regions relatively specialized for that stimulus category were higher than those with patterns outside those regions and varied in strength as a function of the attentional condition. One area, the frontal operculum, was distinguished by selectively interacting with occipitotemporal patterns only when they were the focus of attention. There was no evidence that any frontal or parietal area actively inhibited occipitotemporal representations even when they should be ignored and were suppressed. Using MVPA to decode information within these frontal and parietal areas showed that they contained information about attentional context and/or readout information from occipitotemporal cortex to guide behavior but that frontal regions lacked information about category identity. PMID:24133250

Primary cultures of glomerular parietal epithelial cells or podocytes with proven origin.

NARCIS (Netherlands)

Kabgani, N.; Grigoleit, T.; Schulte, K.; Sechi, A.; Sauer-Lehnen, S.; Tag, C.; Boor, P.; Kuppe, C.; Warsow, G.; Schordan, S.; Mostertz, J.; Chilukoti, R.K.; Homuth, G.; Endlich, N.; Tacke, F.; Weiskirchen, R.; Fuellen, G.; Endlich, K.; Floege, J.; Smeets, B.; Moeller, M.J.

2012-01-01

Parietal epithelial cells (PECs) are crucially involved in the pathogenesis of rapidly progressive glomerulonephritis (RPGN) as well as in focal and segmental glomerulosclerosis (FSGS). In this study, transgenic mouse lines were used to isolate pure, genetically tagged primary cultures of PECs or

Individual structural differences in left inferior parietal area are associated with schoolchildrens’ arithmetic scores

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Yongxin eLi

2013-12-01

Full Text Available Arithmetic skill is of critical importance for academic achievement, professional success and everyday life, and childhood is the key period to acquire this skill. Neuroimaging studies have identified that left parietal regions are a key neural substrate for representing arithmetic skill. Although the relationship between functional brain activity in left parietal regions and arithmetic skill has been studied in detail, it remains unclear about the relationship between arithmetic achievement and structural properties in left inferior parietal area in schoolchildren. The current study employed a combination of voxel-based morphometry (VBM for high-resolution T1-weighted images and fiber tracking on diffusion tensor imaging (DTI to examine the relationship between structural properties in the inferior parietal area and arithmetic achievement in 10-year-old schoolchildren. VBM of the T1-weighted images revealed that individual differences in arithmetic scores were significantly and positively correlated with the grey matter (GM volume in the left intraparietal sulcus (IPS. Fiber tracking analysis revealed that the forceps major, left superior longitudinal fasciculus (SLF, bilateral inferior longitudinal fasciculus (ILF and inferior fronto-occipital fasciculus (IFOF were the primary pathways connecting the left IPS with other brain areas. Furthermore, the regression analysis of the probabilistic pathways revealed a significant and positive correlation between the fractional anisotropy (FA values in the left SLF, ILF and bilateral IFOF and arithmetic scores. The brain structure-behavior correlation analyses indicated that the GM volumes in the left IPS and the FA values in the tract pathways connecting left IPS were both related to children’s arithmetic achievement. The present findings provide evidence that individual structural differences in the left IPS are associated with arithmetic scores in schoolchildren.

An atretic parietal cephalocele associated with multiple intracranial and eye anomalies

International Nuclear Information System (INIS)

Saatci, I.; Yelgec, S.; Aydin, K.; Akalan, N.

1998-01-01

We present the cranial MRI findings in a 4-month-old girl with an atretic parietal cephalocele associated with multiple cerebral and ocular anomalies including lobar holoprosencephaly, a Dandy-Walker malformation, agenesis of the corpus callosum, grey-matter heterotopia, extra-axial cysts in various locations, bilateral microphthalmia and a retroocular cyst. (orig.)

Lateralization of Egocentric and Allocentric Spatial Processing after Parietal Brain Lesions

Science.gov (United States)

Iachini, Tina; Ruggiero, Gennaro; Conson, Massimiliano; Trojano, Luigi

2009-01-01

The purpose of this paper was to verify whether left and right parietal brain lesions may selectively impair egocentric and allocentric processing of spatial information in near/far spaces. Two Right-Brain-Damaged (RBD), 2 Left-Brain-Damaged (LBD) patients (not affected by neglect or language disturbances) and eight normal controls were submitted…

Development of in vitro techniques for individual monitoring of "3"2P

International Nuclear Information System (INIS)

Almeida, A.P.F.; Sousa, W.O.; Dantas, A.L.A.; Dantas, B.M.

2016-01-01

The "3"2P is used in the form of liquid unsealed sources in medical facilities, research and teaching, representing a risk of internal exposure in routine activities and in case of accidental incorporation. The evaluation of "3"2P incorporation can be accomplished through in vitro bioanalysis of urine. This paper aims to provide a methodology to analyze "3"2P in biological samples, applicable to internal individual monitoring using liquid scintillation technique. The minimum detectable activity of the system was determined and the sensitivity of the technique was evaluated, based on the detected minimum effective dose. (author)

Central and peripheral components of writing critically depend on a defined area of the dominant superior parietal gyrus.

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Magrassi, Lorenzo; Bongetta, Daniele; Bianchini, Simonetta; Berardesca, Marta; Arienta, Cesare

2010-07-30

Classical neuropsychological models of writing separate central (linguistic) processes common to oral spelling, writing and typing from peripheral (motor) processes that are modality specific. Damage to the left superior parietal gyrus, an area of the cortex involved in peripheral processes specific to handwriting, should generate distorted graphemes but not misspelled words, while damage to other areas of the cortex like the frontal lobe should produce alterations in written and oral spelling without distorted graphemes. We describe the clinical and neuropsychological features of a patient with combined agraphia for handwriting and typewriting bearing a small glioblastoma in the left parietal lobe. His agraphia resolved after antiedema therapy and we tested by bipolar cortical stimulation his handwriting abilities during an awake neurosurgical procedure. We found that we could reversibly re-induce the same defects of writing by stimulating during surgery a limited area of the superior parietal gyrus in the same patient and in an independent patient that was never agraphic before the operation. In those patients stimulation caused spelling errors, poorly formed letters and in some cases a complete cessation of writing with minimal or no effects on oral spelling. Our results suggest that stimulating a specific area in the superior parietal gyrus we can generate different patterns of agraphia. Moreover, our findings also suggest that some of the central processes specific for typing and handwriting converge with motor processes at least in the limited portion of the superior parietal gyrus we mapped in our patients. Copyright 2010 Elsevier B.V. All rights reserved.

The parietal cell gastric H, K-ATPase also functions as the Na, K-ATPase and Ca-ATPase in altered states.

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Ray, Tushar

2013-01-01

This article offers an explanation for the apparent lack of Na, K-ATPase activity in parietal cells although ouabain has been known to inhibit gastric acid secretion since 1962. The gastric H, K-ATPase (proton-pump) seems to be acting in altered states, thus behaving like a Na, K-ATPase (Na-pump) and/or Ca-ATPase (Ca-pump) depending on cellular needs.  This conclusion is based on the following findings. First, parietal cell fractions do not exhibit Na, K-ATPase activity at pH 7.0 but do at pH 8.5. Second, the apical plasma membrane (APM) fraction exhibits a (Ca or Mg)-ATPase activity with negligible H, K-ATPase activity. However, when assayed with Mg alone in presence of the 80 k Da cytosolic proton-pump activator (HAF), the APM fraction reveals remarkably high H, K-ATPase activity, suggesting the observed low affinity of Ca (or Mg)-ATPase is an altered state of the latter. Third, calcium (between 1 and 4 µM) shows both stimulation and inhibition of the HAF-stimulated H, K-ATPase depending on its concentration, revealing a close interaction between the  proton-pump activator and local Ca concentration in gastric H, K-ATPase function. Such interactions suggest that Ca is acting as a terminal member of the intracellular signaling system for the HAF-regulated proton-pump. It appears that during resting state, the HAF-associated H, K-ATPase remains inhibited by Ca (>1 µM) and, prior to resumption of acid secretion the gastric H, K-ATPase acts temporarily as a Ca-pump for removing excess Ca from its immediate environment. This conclusion is consistent with the recent reports of immunochemical co-localization of the gastric H, K-ATPase and Ca-ATPase by superimposition in parietal cells, and a transitory efflux of Ca immediately preceding the onset of acid secretion. These new perspectives on proton-pump function would open new avenues for a fuller understanding of the intracellular regulation of the ubiquitous Na-pump.

Noninvasive brain stimulation of the parietal lobe for improving neurologic, neuropsychologic, and neuropsychiatric deficits.

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Bolognini, Nadia; Miniussi, Carlo

2018-01-01

Transcranial magnetic stimulation (TMS) and transcranial electric stimulation (tES) are noninvasive brain stimulation (NIBS) tools that are now widely used in neuroscientific research in humans. The fact that both TMS and tES are able to modulate brain plasticity and, in turn, affect behavior is opening up new horizons in the treatment of brain circuit and plasticity disorders. In the present chapter, we will first provide the reader with a brief background on the basic principles of NIBS, describing the electromagnetic and physical foundations of TMS and tES, as well as the current knowledge of the neurophysiologic basis of their effects on brain activity and plasticity. In the main part, we will outline studies aimed at improving persistent symptoms and deficits in patients suffering from neurologic and neuropsychiatric disorders featured by dysfunction of the parietal lobe. The emerging view is that NIBS of parietal areas holds the promise to overcome various sensory, motor, and cognitive disorders that are often refractory to standard medical or behavioral therapies. The chapter closes with an outlook on further developments in this realm, discussing novel therapeutic approaches that could lead to more effective rehabilitation procedures, better suited for the specific parietal lobe dysfunction. Copyright © 2018 Elsevier B.V. All rights reserved.

Thalamic and parietal brain morphology predicts auditory category learning.

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Scharinger, Mathias; Henry, Molly J; Erb, Julia; Meyer, Lars; Obleser, Jonas

2014-01-01

Auditory categorization is a vital skill involving the attribution of meaning to acoustic events, engaging domain-specific (i.e., auditory) as well as domain-general (e.g., executive) brain networks. A listener's ability to categorize novel acoustic stimuli should therefore depend on both, with the domain-general network being particularly relevant for adaptively changing listening strategies and directing attention to relevant acoustic cues. Here we assessed adaptive listening behavior, using complex acoustic stimuli with an initially salient (but later degraded) spectral cue and a secondary, duration cue that remained nondegraded. We employed voxel-based morphometry (VBM) to identify cortical and subcortical brain structures whose individual neuroanatomy predicted task performance and the ability to optimally switch to making use of temporal cues after spectral degradation. Behavioral listening strategies were assessed by logistic regression and revealed mainly strategy switches in the expected direction, with considerable individual differences. Gray-matter probability in the left inferior parietal lobule (BA 40) and left precentral gyrus was predictive of "optimal" strategy switch, while gray-matter probability in thalamic areas, comprising the medial geniculate body, co-varied with overall performance. Taken together, our findings suggest that successful auditory categorization relies on domain-specific neural circuits in the ascending auditory pathway, while adaptive listening behavior depends more on brain structure in parietal cortex, enabling the (re)direction of attention to salient stimulus properties. © 2013 Published by Elsevier Ltd.

Recency Effects in the Inferior Parietal Lobe during Verbal Recognition Memory

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Bradley Russell Buchsbaum

2011-07-01

Full Text Available The most recently encountered information is often most easily remembered in psychological tests of memory. Recent investigations of the neural basis of such recency effects have shown that activation in the lateral inferior parietal cortex (LIPC tracks the recency of a probe item when subjects make recognition memory judgments. A key question regarding recency effects in the LIPC is whether they fundamentally reflect the storage (and strength of information in memory, or whether such effects are a consequence of task difficulty or an upswing in resting state network activity. Using functional magnetic resonance imaging (fMRI we show that recency effects in the LIPC are independent of the difficulty of recognition memory decisions, that they are not a by-product of an increase in resting state network activity, and that they appear to dissociate from regions known to be involved in verbal working memory maintenance. We conclude with a discussion of two alternative explanations – the memory strength and expectancy hypotheses, respectively -- of the parietal lobe recency effect.

EEG source reconstruction reveals frontal-parietal dynamics of spatial conflict processing

OpenAIRE

Cohen, M.X.; Ridderinkhof, K.R.

2013-01-01

Cognitive control requires the suppression of distracting information in order to focus on task-relevant information. We applied EEG source reconstruction via time-frequency linear constrained minimum variance beamforming to help elucidate the neural mechanisms involved in spatial conflict processing. Human subjects performed a Simon task, in which conflict was induced by incongruence between spatial location and response hand. We found an early (?200 ms post-stimulus) conflict modulation in ...

Multi-Tasking and Choice of Training Data Influencing Parietal ERP Expression and Single-Trial Detection—Relevance for Neuroscience and Clinical Applications

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Kirchner, Elsa A.; Kim, Su Kyoung

2018-01-01

Event-related potentials (ERPs) are often used in brain-computer interfaces (BCIs) for communication or system control for enhancing or regaining control for motor-disabled persons. Especially results from single-trial EEG classification approaches for BCIs support correlations between single-trial ERP detection performance and ERP expression. Hence, BCIs can be considered as a paradigm shift contributing to new methods with strong influence on both neuroscience and clinical applications. Here, we investigate the relevance of the choice of training data and classifier transfer for the interpretability of results from single-trial ERP detection. In our experiments, subjects performed a visual-motor oddball task with motor-task relevant infrequent (targets), motor-task irrelevant infrequent (deviants), and motor-task irrelevant frequent (standards) stimuli. Under dual-task condition, a secondary senso-motor task was performed, compared to the simple-task condition. For evaluation, average ERP analysis and single-trial detection analysis with different numbers of electrodes were performed. Further, classifier transfer was investigated between simple and dual task. Parietal positive ERPs evoked by target stimuli (but not by deviants) were expressed stronger under dual-task condition, which is discussed as an increase of task emphasis and brain processes involved in task coordination and change of task set. Highest classification performance was found for targets irrespective whether all 62, 6 or 2 parietal electrodes were used. Further, higher detection performance of targets compared to standards was achieved under dual-task compared to simple-task condition in case of training on data from 2 parietal electrodes corresponding to results of ERP average analysis. Classifier transfer between tasks improves classification performance in case that training took place on more varying examples (from dual task). In summary, we showed that P300 and overlaying parietal positive

Multimodal FMRI resting-state functional connectivity in granulin mutations: the case of fronto-parietal dementia.

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Enrico Premi

Full Text Available BACKGROUND: Monogenic dementias represent a great opportunity to trace disease progression from preclinical to symptomatic stages. Frontotemporal Dementia related to Granulin (GRN mutations presents a specific framework of brain damage, involving fronto-temporal regions and long inter-hemispheric white matter bundles. Multimodal resting-state functional MRI (rs-fMRI is a promising tool to carefully describe disease signature from the earliest disease phase. OBJECTIVE: To define local connectivity alterations in GRN related pathology moving from the presymptomatic (asymptomatic GRN mutation carriers to the clinical phase of the disease (GRN- related Frontotemporal Dementia. METHODS: Thirty-one GRN Thr272fs mutation carriers (14 patients with Frontotemporal Dementia and 17 asymptomatic carriers and 38 healthy controls were recruited. Local connectivity measures (Regional Homogeneity (ReHo, Fractional Amplitude of Low Frequency Fluctuation (fALFF and Degree Centrality (DC were computed, considering age and gender as nuisance variables as well as the influence of voxel-level gray matter atrophy. RESULTS: Asymptomatic GRN carriers had selective reduced ReHo in the left parietal region and increased ReHo in frontal regions compared to healthy controls. Considering Frontotemporal Dementia patients, all measures (ReHo, fALFF and DC were reduced in inferior parietal, frontal lobes and posterior cingulate cortex. Considering GRN mutation carriers, an inverse correlation with age in the posterior cingulate cortex, inferior parietal lobule and orbitofrontal cortex was found. CONCLUSIONS: GRN pathology is characterized by functional brain network alterations even decades before the clinical onset; they involve the parietal region primarily and then spread to the anterior regions of the brain, supporting the concept of molecular nexopathies.

Posterior Parietal Cortex and Episodic Encoding: Insights from fMRI Subsequent Memory Effects and Dual Attention Theory

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Uncapher, Melina; Wagner, Anthony D.

2010-01-01

The formation of episodic memories –– memories for life events –– is affected by attention during event processing. A leading neurobiological model of attention posits two separate yet interacting systems that depend on distinct regions in lateral posterior parietal cortex (PPC). From this dual-attention perspective, dorsal PPC is thought to support the goal-directed allocation of attention, whereas ventral PPC is thought to support reflexive orienting to information that automatically captures attention. To advance understanding of how parietal mechanisms may impact event encoding, we review functional MRI studies that document the relationship between lateral PPC activation during encoding and subsequent memory performance (e.g., later remembering or forgetting). This review reveals that (a) encoding-related activity is frequently observed in human lateral PPC, (b) increased activation in dorsal PPC is associated with later memory success, and (c) increased activation in ventral PPC predominantly correlates with later memory failure. From a dual-attention perspective, these findings suggest that allocating goal-directed attention during event processing increases the probability that the event will be remembered later, whereas the capture of reflexive attention during event processing may have negative consequences for event encoding. The prevalence of encoding-related activation in parietal cortex suggests that neurobiological models of episodic memory should consider how parietal-mediated attentional mechanisms regulate encoding. PMID:19028591

p3d--Python module for structural bioinformatics.

Science.gov (United States)

Fufezan, Christian; Specht, Michael

2009-08-21

High-throughput bioinformatic analysis tools are needed to mine the large amount of structural data via knowledge based approaches. The development of such tools requires a robust interface to access the structural data in an easy way. For this the Python scripting language is the optimal choice since its philosophy is to write an understandable source code. p3d is an object oriented Python module that adds a simple yet powerful interface to the Python interpreter to process and analyse three dimensional protein structure files (PDB files). p3d's strength arises from the combination of a) very fast spatial access to the structural data due to the implementation of a binary space partitioning (BSP) tree, b) set theory and c) functions that allow to combine a and b and that use human readable language in the search queries rather than complex computer language. All these factors combined facilitate the rapid development of bioinformatic tools that can perform quick and complex analyses of protein structures. p3d is the perfect tool to quickly develop tools for structural bioinformatics using the Python scripting language.

Copper Selenidophosphates Cu4P2Se6, Cu4P3Se4, Cu4P4Se3, and CuP2Se, Featuring Zero-, One-, and Two-Dimensional Anions.

Science.gov (United States)

Kuhn, Alexander; Schoop, Leslie M; Eger, Roland; Moudrakovski, Igor; Schwarzmüller, Stefan; Duppel, Viola; Kremer, Reinhard K; Oeckler, Oliver; Lotsch, Bettina V

2016-08-15

Five new compounds in the Cu/P/Se phase diagram have been synthesized, and their crystal structures have been determined. The crystal structures of these compounds comprise four previously unreported zero-, one-, and two-dimensional selenidophosphate anions containing low-valent phosphorus. In addition to two new modifications of Cu4P2Se6 featuring the well-known hexaselenidohypodiphosphate(IV) ion, there are three copper selenidophosphates with low-valent P: Cu4P3Se4 contains two different new anions, (i) a monomeric (zero-dimensional) selenidophosphate anion [P2Se4](4-) and (ii) a one-dimensional selenidophosphate anion [Formula: see text], which is related to the well-known gray-Se-like [Formula: see text] Zintl anion. Cu4P4Se3 contains one-dimensional [Formula: see text] polyanions, whereas CuP2Se contains the 2D selenidophosphate [Formula: see text] polyanion. It consists of charge-neutral CuP2Se layers separated by a van der Waals gap which is very rare for a Zintl-type phase. Hence, besides black P, CuP2Se constitutes a new possible source of 2D oxidized phosphorus containing layers for intercalation or exfoliation experiments. Additionally, the electronic structures and some fundamental physical properties of the new compounds are reported. All compounds are semiconducting with indirect band gaps of the orders of around 1 eV. The phases reported here add to the structural diversity of chalcogenido phosphates. The structural variety of this family of compounds may translate into a variety of tunable physical properties.

Glomerular parietal epithelial cells in kidney physiology, pathology, and repair

OpenAIRE

Shankland, Stuart J.; Anders, Hans-Joachim; Romagnani, Paola

2013-01-01

Purpose of review We have summarized recently published glomerular parietal epithelial cell (PEC) research, focusing on their roles in glomerular development and physiology, and in certain glomerular diseases. The rationale is that PECs have been largely ignored until the recent availability of cell lineage tracing studies, human and murine PEC culture systems, and potential therapeutic interventions of PECs. Recent findings Several new paradigms involving PECs have emerged demonstrating thei...

Gas1 expression in parietal cells of Bowman's capsule in experimental diabetic nephropathy.

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Luna-Antonio, Brenda I; Rodriguez-Muñoz, Rafael; Namorado-Tonix, Carmen; Vergara, Paula; Segovia, Jose; Reyes, Jose L

2017-07-01

Gas1 (Growth Arrest-Specific 1) is a pleiotropic protein with novel functions including anti-proliferative and proapoptotic activities. In the kidney, the expression of Gas1 has been described in mesangial cells. In this study, we described that renal parietal cells of Bowman's capsule (BC) and the distal nephron cells also express Gas1. The role of Gas1 in the kidney is not yet known. There is a subpopulation of progenitor cells in Bowman's capsule with self-renewal properties which can eventually differentiate into podocytes as a possible mechanism of regeneration in the early stages of diabetic nephropathy. We analyzed the expression of Gas1 in the parietal cells of Bowman's capsule in murine experimental diabetes. We found that diabetes reduced the expression of Gas1 and increased the expression of progenitor markers like NCAM, CD24, and SIX1/2, and mesenchymal markers like PAX2 in the Bowman's capsule. We also analyzed the expression of WT1 (a podocyte-specific marker) on BC and observed an increase in the number of WT1 positive cells in diabetes. In contrast, nephrin, another podocyte-specific protein, decreases its expression in the first week of diabetes in the glomerular tuft, which is gradually restored during the second and third weeks of diabetes. These results suggest that in diabetes the decrease of Gas1 promotes the activation of parietal progenitor cells of Bowman's capsule that might differentiate into podocytes and compensate their loss observed in this pathology.

Frontal and parietal theta burst TMS impairs working memory for visual-spatial conjunctions.

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Morgan, Helen M; Jackson, Margaret C; van Koningsbruggen, Martijn G; Shapiro, Kimron L; Linden, David E J

2013-03-01

In tasks that selectively probe visual or spatial working memory (WM) frontal and posterior cortical areas show a segregation, with dorsal areas preferentially involved in spatial (e.g. location) WM and ventral areas in visual (e.g. object identity) WM. In a previous fMRI study [1], we showed that right parietal cortex (PC) was more active during WM for orientation, whereas left inferior frontal gyrus (IFG) was more active during colour WM. During WM for colour-orientation conjunctions, activity in these areas was intermediate to the level of activity for the single task preferred and non-preferred information. To examine whether these specialised areas play a critical role in coordinating visual and spatial WM to perform a conjunction task, we used theta burst transcranial magnetic stimulation (TMS) to induce a functional deficit. Compared to sham stimulation, TMS to right PC or left IFG selectively impaired WM for conjunctions but not single features. This is consistent with findings from visual search paradigms, in which frontal and parietal TMS selectively affects search for conjunctions compared to single features, and with combined TMS and functional imaging work suggesting that parietal and frontal regions are functionally coupled in tasks requiring integration of visual and spatial information. Our results thus elucidate mechanisms by which the brain coordinates spatially segregated processing streams and have implications beyond the field of working memory. Copyright © 2013 Elsevier Inc. All rights reserved.

Dipolar sources of the early scalp somatosensory evoked potentials to upper limb stimulation. Effect of increasing stimulus rates.

Science.gov (United States)

Valeriani, M; Restuccia, D; Di Lazzaro, V; Le Pera, D; Barba, C; Tonali, P; Mauguiere, F

1998-06-01

Brain electrical source analysis (BESA) of the scalp electroencephalographic activity is well adapted to distinguish neighbouring cerebral generators precisely. Therefore, we performed dipolar source modelling in scalp medium nerve somatosensory evoked potentials (SEPs) recorded at 1.5-Hz stimulation rate, where all the early components should be identifiable. We built a four-dipole model, which was issued from the grand average, and applied it also to recordings from single individuals. Our model included a dipole at the base of the skull and three other perirolandic dipoles. The first of the latter dipoles was tangentially oriented and was active at the same latencies as the N20/P20 potential and, with opposite polarity, the P24/N24 response. The second perirolandic dipole showed an initial peak of activity slightly earlier than that of the N20/P20 dipolar source and, later, it was active at the same latency as the central P22 potential. Lastly, the third perirolandic dipole explaining the fronto-central N30 potential scalp distribution was constantly more posterior than the first one. In order to evaluate the effect of an increasing repetition frequency on the activity of SEP dipolar sources, we applied the model built from 1.5-Hz SEPs to traces recorded at 3-Hz and 10-Hz repetition rates. We found that the 10-Hz stimulus frequency reduced selectively the later of the two activity phases of the first perirolandic dipole. The decrement in strength of this dipolar source can be explained if we assume that: (a) the later activity of the first perirolandic dipole can represent the inhibitory phase of a "primary response"; (b) two different clusters of cells generate the opposite activities of the tangential perirolandic dipole. An additional finding in our model was that two different perirolandic dipoles contribute to the centro-parietal N20 potential generation.

Radioactive sources astray; Radioaktive kilder på avveier

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-02-01

In Norway, every year 2-3 incidents where radioactive sources are going astray happens. This can lead to serious consequences with the risk to both humans and the environment. Radioactive sources out of control are often ancient sources no longer in use and will be sent back to the dealer or an approved waste disposal facility.Radiation safety regulations has provisions for the acquisition, management and disposal of radioactive sources to assure proper use and handling of radioactive sources in the community. It is given here information about how businesses should deal with radioactive sources which have been taken out of use, and what should be done by discovery or suspected discovery of radioactivity in return metal industry.(eb)

Activity in the fronto-parietal network indicates numerical inductive reasoning beyond calculation: An fMRI study combined with a cognitive model.

Science.gov (United States)

Liang, Peipeng; Jia, Xiuqin; Taatgen, Niels A; Borst, Jelmer P; Li, Kuncheng

2016-05-19

Numerical inductive reasoning refers to the process of identifying and extrapolating the rule involved in numeric materials. It is associated with calculation, and shares the common activation of the fronto-parietal regions with calculation, which suggests that numerical inductive reasoning may correspond to a general calculation process. However, compared with calculation, rule identification is critical and unique to reasoning. Previous studies have established the central role of the fronto-parietal network for relational integration during rule identification in numerical inductive reasoning. The current question of interest is whether numerical inductive reasoning exclusively corresponds to calculation or operates beyond calculation, and whether it is possible to distinguish between them based on the activity pattern in the fronto-parietal network. To directly address this issue, three types of problems were created: numerical inductive reasoning, calculation, and perceptual judgment. Our results showed that the fronto-parietal network was more active in numerical inductive reasoning which requires more exchanges between intermediate representations and long-term declarative knowledge during rule identification. These results survived even after controlling for the covariates of response time and error rate. A computational cognitive model was developed using the cognitive architecture ACT-R to account for the behavioral results and brain activity in the fronto-parietal network.

Distinct parietal sites mediate the influences of mood, arousal, and their interaction on human recognition memory.

Science.gov (United States)

Greene, Ciara M; Flannery, Oliver; Soto, David

2014-12-01

The two dimensions of emotion, mood valence and arousal, have independent effects on recognition memory. At present, however, it is not clear how those effects are reflected in the human brain. Previous research in this area has generally dealt with memory for emotionally valenced or arousing stimuli, but the manner in which interacting mood and arousal states modulate responses in memory substrates remains poorly understood. We investigated memory for emotionally neutral items while independently manipulating mood valence and arousal state by means of music exposure. Four emotional conditions were created: positive mood/high arousal, positive mood/low arousal, negative mood/high arousal, and negative mood/low arousal. We observed distinct effects of mood valence and arousal in parietal substrates of recognition memory. Positive mood increased activity in ventral posterior parietal cortex (PPC) and orbitofrontal cortex, whereas arousal condition modulated activity in dorsal PPC and the posterior cingulate. An interaction between valence and arousal was observed in left ventral PPC, notably in a parietal area distinct from the those identified for the main effects, with a stronger effect of mood on recognition memory responses here under conditions of relative high versus low arousal. We interpreted the PPC activations in terms of the attention-to-memory hypothesis: Increased arousal may lead to increased top-down control of memory, and hence dorsal PPC activation, whereas positive mood valence may result in increased activity in ventral PPC regions associated with bottom-up attention to memory. These findings indicate that distinct parietal sites mediate the influences of mood, arousal, and their interplay during recognition memory.

High-Fidelity RF Gun Simulations with the Parallel 3D Finite Element Particle-In-Cell Code Pic3P

Energy Technology Data Exchange (ETDEWEB)

Candel, A; Kabel, A.; Lee, L.; Li, Z.; Limborg, C.; Ng, C.; Schussman, G.; Ko, K.; /SLAC

2009-06-19

SLAC's Advanced Computations Department (ACD) has developed the first parallel Finite Element 3D Particle-In-Cell (PIC) code, Pic3P, for simulations of RF guns and other space-charge dominated beam-cavity interactions. Pic3P solves the complete set of Maxwell-Lorentz equations and thus includes space charge, retardation and wakefield effects from first principles. Pic3P uses higher-order Finite Elementmethods on unstructured conformal meshes. A novel scheme for causal adaptive refinement and dynamic load balancing enable unprecedented simulation accuracy, aiding the design and operation of the next generation of accelerator facilities. Application to the Linac Coherent Light Source (LCLS) RF gun is presented.

Time course of the involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum in emotional prosody perception.

Directory of Open Access Journals (Sweden)

Marjolijn Hoekert

Full Text Available In verbal communication, not only the meaning of the words convey information, but also the tone of voice (prosody conveys crucial information about the emotional state and intentions of others. In various studies right frontal and right temporal regions have been found to play a role in emotional prosody perception. Here, we used triple-pulse repetitive transcranial magnetic stimulation (rTMS to shed light on the precise time course of involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum. We hypothesized that information would be processed in the right anterior superior temporal gyrus before being processed in the right fronto-parietal operculum. Right-handed healthy subjects performed an emotional prosody task. During listening to each sentence a triplet of TMS pulses was applied to one of the regions at one of six time points (400-1900 ms. Results showed a significant main effect of Time for right anterior superior temporal gyrus and right fronto-parietal operculum. The largest interference was observed half-way through the sentence. This effect was stronger for withdrawal emotions than for the approach emotion. A further experiment with the inclusion of an active control condition, TMS over the EEG site POz (midline parietal-occipital junction, revealed stronger effects at the fronto-parietal operculum and anterior superior temporal gyrus relative to the active control condition. No evidence was found for sequential processing of emotional prosodic information from right anterior superior temporal gyrus to the right fronto-parietal operculum, but the results revealed more parallel processing. Our results suggest that both right fronto-parietal operculum and right anterior superior temporal gyrus are critical for emotional prosody perception at a relatively late time period after sentence onset. This may reflect that emotional cues can still be ambiguous at the beginning of sentences, but become

Time course of the involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum in emotional prosody perception.

Science.gov (United States)

Hoekert, Marjolijn; Bais, Leonie; Kahn, René S; Aleman, André

2008-05-21

In verbal communication, not only the meaning of the words convey information, but also the tone of voice (prosody) conveys crucial information about the emotional state and intentions of others. In various studies right frontal and right temporal regions have been found to play a role in emotional prosody perception. Here, we used triple-pulse repetitive transcranial magnetic stimulation (rTMS) to shed light on the precise time course of involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum. We hypothesized that information would be processed in the right anterior superior temporal gyrus before being processed in the right fronto-parietal operculum. Right-handed healthy subjects performed an emotional prosody task. During listening to each sentence a triplet of TMS pulses was applied to one of the regions at one of six time points (400-1900 ms). Results showed a significant main effect of Time for right anterior superior temporal gyrus and right fronto-parietal operculum. The largest interference was observed half-way through the sentence. This effect was stronger for withdrawal emotions than for the approach emotion. A further experiment with the inclusion of an active control condition, TMS over the EEG site POz (midline parietal-occipital junction), revealed stronger effects at the fronto-parietal operculum and anterior superior temporal gyrus relative to the active control condition. No evidence was found for sequential processing of emotional prosodic information from right anterior superior temporal gyrus to the right fronto-parietal operculum, but the results revealed more parallel processing. Our results suggest that both right fronto-parietal operculum and right anterior superior temporal gyrus are critical for emotional prosody perception at a relatively late time period after sentence onset. This may reflect that emotional cues can still be ambiguous at the beginning of sentences, but become more apparent half

Autoimmune gastritis and parietal cell reactivity in two children with abnormal intestinal permeability

NARCIS (Netherlands)

Greenwood, Deanne L. V.; Crock, Patricia; Braye, Stephen; Davidson, Patricia; Sentry, John W.

Autoimmune gastritis is characterised by lymphocytic infiltration of the gastric submucosa, with loss of parietal and chief cells and achlorhydria. Often, gastritis is expressed clinically as cobalamin deficiency with megaloblastic anaemia, which is generally described as a disease of the elderly.

InP MMIC Chip Set for Power Sources Covering 80-170 GHz

Science.gov (United States)

Ngo, Catherine

2001-01-01

We will present a Monolithic Millimeter-wave Integrated Circuit (MMIC) chip set which provides high output-power sources for driving diode frequency multipliers into the terahertz range. The chip set was fabricated at HRL Laboratories using a 0.1-micrometer gate-length InAlAs/InGaAs/InP high electron mobility transistor (HEMT) process, and features transistors with an f(sub max) above 600 GHz. The HRL InP HEMT process has already demonstrated amplifiers in the 60-200 GHz range. In this paper, these high frequency HEMTs form the basis for power sources up to 170 GHz. A number of state-of-the-art InP HEMT MMICs will be presented. These include voltage-controlled and fixed-tuned oscillators, power amplifiers, and an active doubler. We will first discuss an 80 GHz voltage-controlled oscillator with 5 GHz of tunability and at least 17 mW of output power, as well as a 120 GHz oscillator providing 7 mW of output power. In addition, we will present results of a power amplifier which covers the full WRIO waveguide band (75-110 GHz), and provides 40-50 mW of output power. Furthermore, we will present an active doubler at 164 GHz providing 8% bandwidth, 3 mW of output power, and an unprecedented 2 dB of conversion loss for an InP HEMT MMIC at this frequency. Finally, we will demonstrate a power amplifier to cover 140-170 GHz with 15-25 mW of output power and 8 dB gain. These components can form a power source in the 155-165 GHz range by cascading the 80 GHz oscillator, W-band power amplifier, 164 GHz active doubler and final 140-170 GHz power amplifier for a stable, compact local oscillator subsystem, which could be used for atmospheric science or astrophysics radiometers.

Analysis of 3d7-3d64p transitions in the sixth spectrum of zinc: Zn VI

International Nuclear Information System (INIS)

Kleef, T.A.M. van; Joshi, Y.N.; Barakat, M.M.; Meijer, F.G.

1984-01-01

The spectrum of zinc was photographed in the 160-550 A region on a 6.65 m grazing incidence spectrograph. The sources used were a triggered spark and a sliding spark. On the basis of our new observations, all levels of the 3d 7 configuration and 161 out of 180 levels of the 3d 6 4p configuration of Zn VI have been established. The least-squares-fit (LSF) and Hartree-Fock (HF) parameter calculations support the analysis. Two hundred and seventy seven (277) lines have been classified in the 3d 7 -3d 6 4p transition array. (orig.)

Regulation of the Type III InsP3 Receptor by InsP3 and ATP

OpenAIRE

Hagar, Robert E.; Ehrlich, Barbara E.

2000-01-01

Many hormones and neurotransmitters raise intracellular calcium (Ca(2+)) by generating InsP(3) and activating the inositol 1,4, 5-trisphosphate receptor (InsP(3)R). Multiple isoforms with distinct InsP(3) binding properties () have been identified (). The type III InsP(3)R lacks Ca(2+)-dependent inhibition, a property that makes it ideal for signal initiation (). Regulation of the type III InsP(3)R by InsP(3) and ATP was explored in detail using planar lipid bilayers. In comparison to the typ...

Parietal scalp is another affected area in female pattern hair loss: an analysis of hair density and hair diameter

Directory of Open Access Journals (Sweden)

Rojhirunsakool S

2017-12-01

Full Text Available Salinee Rojhirunsakool, Poonkiat Suchonwanit Department of Medicine, Division of Dermatology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand Purpose: Female pattern hair loss (FPHL is a common hair disease. However, studies of the quantitative measurement of FPHL are still limited. The aim of this study was to investigate the characteristics of hair density and hair diameter in normal women and FPHL patients, and further correlate the quantitative measurement with the clinical presentation of FPHL.Patients and methods: An evaluation of 471 FPHL patients and 236 normal women was carried out according to the Ludwig classification, and analysis was performed by using a computerized handheld USB camera with computer-assisted software. Various areas of the scalp, including frontal, parietal, midscalp, and occipital, were analyzed for hair density, non-vellus hair diameter, and percentage of miniaturized hair.Results: The hair density in normal women was the highest and the lowest in the midscalp and parietal areas, respectively. The FPHL group revealed the lowest hair density in the parietal area. Significant differences in hair density, non-vellus hair diameter, and percentage of miniaturized hair between the normal and FPHL groups were observed, especially in the midscalp and parietal areas.Conclusion: The parietal area is another important affected area in FPHL in addition to the midscalp area. This finding provides novel important information of FPHL and will be useful for hair transplant surgeons choosing the optimal donor sites for hair transplantation in women. Keywords: androgenetic alopecia, alopecia, phototrichogram, miniaturization

The Regenerative Potential of Parietal Epithelial Cells in Adult Mice

OpenAIRE

Berger, Katja; Schulte, Kevin; Boor, Peter; Kuppe, Christoph; van Kuppevelt, Toin H.; Floege, Jürgen; Smeets, Bart; Moeller, Marcus J.

2014-01-01

Previously, we showed that some podocytes in juvenile mice are recruited from cells lining Bowman’s capsule, suggesting that parietal epithelial cells (PECs) are a progenitor cell population for podocytes. To investigate whether PECs also replenish podocytes in adult mice, PECs were genetically labeled in an irreversible fashion in 5-week-old mice. No significant increase in labeled podocytes was observed, even after 18 months. To accelerate a potential regenerative mechanism, progressive glo...

P300 component of event-related potentials in persons with asperger disorder.

Science.gov (United States)

Iwanami, Akira; Okajima, Yuka; Ota, Haruhisa; Tani, Masayuki; Yamada, Takashi; Yamagata, Bun; Hashimoto, Ryuichiro; Kanai, Chieko; Takashio, Osamu; Inamoto, Atsuko; Ono, Taisei; Takayama, Yukiko; Kato, Nobumasa

2014-10-01

In the present study, we investigated auditory event-related potentials in adults with Asperger disorder and normal controls using an auditory oddball task and a novelty oddball task. Task performance and the latencies of P300 evoked by both target and novel stimuli in the two tasks did not differ between the two groups. Analysis of variance revealed that there was a significant interaction effect between group and electrode site on the mean amplitude of the P300 evoked by novel stimuli, which indicated that there was an altered distribution of the P300 in persons with Asperger disorder. In contrast, there was no significant interaction effect on the mean P300 amplitude elicited by target stimuli. Considering that P300 comprises two main subcomponents, frontal-central-dominant P3a and parietal-dominant P3b, our results suggested that persons with Asperger disorder have enhanced amplitude of P3a, which indicated activated prefrontal function in this task.

Depth of source from long period P-waves

International Nuclear Information System (INIS)

Roy, Falguni

1986-01-01

Short period (SP) seismograms are much better than long period (LP) seismograms to get the time resolution needed for the focal depth estimation. However, complex scattering effects due to crustal inhomogeneities and also the multi-pathing of signals usually complicate the short period records. On the other hand the seismograms from long period signals demonstrate clear coherent body waves. Therefore, for intermediate depths (15-60 km) prediction error filtering of LP signals will be useful for identifying the depth phases. Such a study has been carried out in the first part of this report. In a group of 7 events, the p p phases have been extracted from LP signals and the depths so estimated compared well with the published data. For explosions at shallow depths (depth p phases will tend to cancel each other in LP seismograms. As the source depth increases, the cancellation becomes less effective. This feature can be used for the identification of an event as well as for getting an estimate of the source depth. This phenomenon can be successfully exploited for identifying multiple explosions, because at teleseismic distances (Δ > 30 o ) no LP (around 20s period) P waves will be seen in the seismogram due to such events whereas relatively strong SP signals and LP Rayleigh waves will be observed. This phenomenon has been studied for 16 events. For three of these events having m b as high as 6.1 and presumed to be underground explosions, one could not see any P wave on remaining 13 events (which were classified as earthquakes), it was possible to set a threshold value of m b above which an earthquake should produce LP P-wave signals at a given distance. (author)

Parietal and occipital encephalocele in same child: A rarest variety of double encephalocele.

Science.gov (United States)

Sharma, Somnath; Ojha, Bal Krishan; Chandra, Anil; Singh, Sunil Kumar; Srivastava, Chhitij

2016-05-01

An encephalocele is a protrusion of the brain and/or meninges through a defect in the skull. Based on the location of the skull defect they are classified into sincipital, basal, occipital or parietal varieties. Occurrence of more than one Encephalocele in a patient is very rare and very few cases of double encephalocele are reported. We report an interesting case where a parietal and an occipital encephalocele were present together. The patient was a 2 months boy who was brought to us with complaints of two swelling on the scalp since birth. Neuroimaging studies confirmed it to be a case of double encephalocele. The rarity of the findings prompted us to report this case. The presentation and management of the case along with and review of the relevant literature is presented. Copyright © 2016 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

Interaction between 4p photoionization and 3p resonant excitation channels of krypton

International Nuclear Information System (INIS)

Buhr, T.; Kover, A.; Varga, D.; Muller, A.; Ricz, S.; Justus-Liebig- Universitat Giessen, Giessen; Holste, K.; Borovik, Jr.A.A.; Bernhardt, D.; Schippers, S.

2011-01-01

Complete text of publication follows. The angular distribution of Kr 4p photoelectrons was measured employing a linearly polarized photon beam at energies from 205 eV to 230 eV. In this range the Kr 3p→ns/md (n,m=4,5,6, etc.) resonances can be excited. The experimental anisotropy parameters (β, γ and δ) were determined for the Kr 4p shell and its fine structure components. The measurement was carried out at beamline BW3 of the DORIS III synchrotron light source at HASYLAB (Hamburg, Germany). The ESA-22D electrostatic electron spectrometer was used to analyze the emitted electrons. The spectrometer consists of a spherical and a cylindrical mirror analyzer. The spherical mirror focuses the electrons from the scattering plane to the entrance slit of the cylindrical analyzer performing the energy analysis of the electrons. (For detailed description of an ESA- 22-type electron spectrometer see Ref. [1].) The measured dipole anisotropy parameters ? of Kr 4p photoelectrons are shown in Fig. 1 as a function of photon energy. Resonance-like structure can be seen in the photon energy dependence of the dipole parameters. This structure indicates that the channel interactions are important between the 3p resonant excitation-autoionization and 4p direct photoionization processes in krypton. The natural line width of the 3p photoelectron peaks was determined from the measured spectra and it is about 0.8 eV while the experimental width of the resonance near 220 eV photon energy (3p 1/2 -1 →5s resonant excitation) is approximately 2 eV in Fig. 1. This broadening can be explained with the strong interference between the ionization and excitation channels. As before, we conclude that the angular distribution of photoelectrons is strongly influenced by the excitation processes. Acknowledgements. The authors wish to thank the DORIS III staff for providing excellent working conditions. This work was supported by the NKTH-OTKA (Grant No. K67719), and by the European Community

Parietal disruption alters audiovisual binding in the sound-induced flash illusion.

Science.gov (United States)

Kamke, Marc R; Vieth, Harrison E; Cottrell, David; Mattingley, Jason B

2012-09-01

Selective attention and multisensory integration are fundamental to perception, but little is known about whether, or under what circumstances, these processes interact to shape conscious awareness. Here, we used transcranial magnetic stimulation (TMS) to investigate the causal role of attention-related brain networks in multisensory integration between visual and auditory stimuli in the sound-induced flash illusion. The flash illusion is a widely studied multisensory phenomenon in which a single flash of light is falsely perceived as multiple flashes in the presence of irrelevant sounds. We investigated the hypothesis that extrastriate regions involved in selective attention, specifically within the right parietal cortex, exert an influence on the multisensory integrative processes that cause the flash illusion. We found that disruption of the right angular gyrus, but not of the adjacent supramarginal gyrus or of a sensory control site, enhanced participants' veridical perception of the multisensory events, thereby reducing their susceptibility to the illusion. Our findings suggest that the same parietal networks that normally act to enhance perception of attended events also play a role in the binding of auditory and visual stimuli in the sound-induced flash illusion. Copyright © 2012 Elsevier Inc. All rights reserved.

32P uptake by wheat from sources under various moisture regimes

International Nuclear Information System (INIS)

Chalwade, P.B.; Ghonsikar, C.P.

1983-01-01

P fertilizers containing varying amounts of water soluble and citrate soluble P were evaluated under two (100 and 50 per cent field capacity) moisture regimes on wheat in a pot culture experiment using 32 P technique. It was found that inorganic P sources if combined or complexed with organic matters greatly help P availability in black soils having pH 8.0 and 9.1. However, reduced moisture considerably decreased total P uptake. (author)

Effects of Calcium Source on Biochemical Properties of Microbial CaCO3 Precipitation.

Science.gov (United States)

Xu, Jing; Du, Yali; Jiang, Zhengwu; She, Anming

2015-01-01

The biochemical properties of CaCO3 precipitation induced by Sporosarcina pasteurii, an ureolytic type microorganism, were investigated. Effects of calcium source on the precipitation process were examined, since calcium source plays a key role in microbiologically induced mineralization. Regardless of the calcium source type, three distinct stages in the precipitation process were identified by Ca(2+), NH4 (+), pH and cell density monitoring. Compared with stage 1 and 3, stage 2 was considered as the most critical part since biotic CaCO3 precipitation occurs during this stage. Kinetics studies showed that the microbial CaCO3 precipitation rate for calcium lactate was over twice of that for calcium nitrate, indicating that calcium lactate is more beneficial for the cell activity, which in turn determines urease production and CaCO3 precipitation. X-ray diffraction analysis confirmed the CaCO3 crystal as calcite, although scanning electron microscopy revealed a difference in crystal size and morphology if calcium source was different. The findings of this paper further suggest a promising application of microbiologically induced CaCO3 precipitation in remediation of surface and cracks of porous media, e.g., cement-based composites, particularly by using organic source of calcium lactate.

Pneumothorax simulated by detachment of parietal pleura associated with pneumomediastinum

International Nuclear Information System (INIS)

Rozeik, C.; Kotterer, O.; Deininger, H.K.

1994-01-01

We report a case of blunt chest trauma, where findings on repeated conventional chest radiographs were compatible with pneumothorax developing after 2 days of mechanical high-pressure ventilation. CT showed that the appearance was due to a detachment of the parietal pleura along the lateral, mediastinal and diaphragmatic boundaries of the lungs, imitating a pneumothorax. The case report illustrates the key role of CT in the differential diagnosis of epipleural interstitial air collection versus pneumothorax. (orig./MG)

Pneumothorax simulated by detachment of parietal pleura associated with pneumomediastinum

Energy Technology Data Exchange (ETDEWEB)

Rozeik, C. [Radiologie 1, Staedtische Kliniken Darmstadt (Germany); Kotterer, O. [Radiologie 1, Staedtische Kliniken Darmstadt (Germany); Deininger, H.K. [Radiologie 1, Staedtische Kliniken Darmstadt (Germany)

1994-10-01

We report a case of blunt chest trauma, where findings on repeated conventional chest radiographs were compatible with pneumothorax developing after 2 days of mechanical high-pressure ventilation. CT showed that the appearance was due to a detachment of the parietal pleura along the lateral, mediastinal and diaphragmatic boundaries of the lungs, imitating a pneumothorax. The case report illustrates the key role of CT in the differential diagnosis of epipleural interstitial air collection versus pneumothorax. (orig./MG)

Measurement of the spin-forbidden decay rate (3s3d)1D2¿(3s3p)3 P2,1 in 24Mg

DEFF Research Database (Denmark)

Therkildsen, K. T.; Jensen, Brian Bak; Ryder, C. P.

2009-01-01

We have measured the spin-forbidden decay rate from (3s3d)D12¿(3s3p)P32,1 in M24g atoms trapped in a magneto-optical trap. The total decay rate, summing up both exit channels (3s3p)P31 and (3s3p)P32 , yields 196±10s-1 in excellent agreement with resent relativistic many-body calculations of Porse...

Exercise Training Increases Parietal Lobe Cerebral Blood Flow in Chronic Stroke: An Observational Study

Directory of Open Access Journals (Sweden)

Andrew D. Robertson

2017-09-01

Full Text Available Exercise is increasingly recommended as an essential component of stroke rehabilitation, yet uncertainty remains with respect to its direct effect on the cerebral vasculature. The current study first demonstrated the repeatability of pseudo-continuous arterial spin labeling (ASL magnetic resonance imaging (MRI in older adults with stroke, and then investigated the change in cerebrovascular function following a 6-month cardiovascular rehabilitation program. In the repeatability study, 12 participants at least 3 months post-stroke underwent two ASL imaging scans 1 month apart. In the prospective observational study, eight individuals underwent ASL imaging and aerobic fitness testing before and after a 6-month cardiovascular rehabilitation program. Cerebral blood flow (CBF and the spatial coefficient of variation of CBF (sCoV were quantified to characterize tissue-level perfusion and large cerebral artery transit time properties, respectively. In repeat scanning, intraclass correlation (ICC indicated moderate test-retest reliability for global gray matter CBF (ICC = 0.73 and excellent reliability for sCoV (ICC = 0.94. In the observational study, gray matter CBF increased after training (baseline: 40 ± 13 vs. 6-month: 46 ± 12 ml·100 g−1·min−1, P = 0.036. The greatest change occurred in the parietal lobe (+18 ± 12%. Gray matter sCoV, however, did not change following training (P = 0.31. This study provides preliminary evidence that exercise-based rehabilitation in chronic stroke enhances tissue-level perfusion, without changing the relative hemodynamic properties of the large cerebral arteries.

Exercise Training Increases Parietal Lobe Cerebral Blood Flow in Chronic Stroke: An Observational Study

Science.gov (United States)

Robertson, Andrew D.; Marzolini, Susan; Middleton, Laura E.; Basile, Vincenzo S.; Oh, Paul I.; MacIntosh, Bradley J.

2017-01-01

Exercise is increasingly recommended as an essential component of stroke rehabilitation, yet uncertainty remains with respect to its direct effect on the cerebral vasculature. The current study first demonstrated the repeatability of pseudo-continuous arterial spin labeling (ASL) magnetic resonance imaging (MRI) in older adults with stroke, and then investigated the change in cerebrovascular function following a 6-month cardiovascular rehabilitation program. In the repeatability study, 12 participants at least 3 months post-stroke underwent two ASL imaging scans 1 month apart. In the prospective observational study, eight individuals underwent ASL imaging and aerobic fitness testing before and after a 6-month cardiovascular rehabilitation program. Cerebral blood flow (CBF) and the spatial coefficient of variation of CBF (sCoV) were quantified to characterize tissue-level perfusion and large cerebral artery transit time properties, respectively. In repeat scanning, intraclass correlation (ICC) indicated moderate test-retest reliability for global gray matter CBF (ICC = 0.73) and excellent reliability for sCoV (ICC = 0.94). In the observational study, gray matter CBF increased after training (baseline: 40 ± 13 vs. 6-month: 46 ± 12 ml·100 g−1·min−1, P = 0.036). The greatest change occurred in the parietal lobe (+18 ± 12%). Gray matter sCoV, however, did not change following training (P = 0.31). This study provides preliminary evidence that exercise-based rehabilitation in chronic stroke enhances tissue-level perfusion, without changing the relative hemodynamic properties of the large cerebral arteries. PMID:29033829

Posterior parietal cortex mediates encoding and maintenance processes in change blindness.

Science.gov (United States)

Tseng, Philip; Hsu, Tzu-Yu; Muggleton, Neil G; Tzeng, Ovid J L; Hung, Daisy L; Juan, Chi-Hung

2010-03-01

It is commonly accepted that right posterior parietal cortex (PPC) plays an important role in updating spatial representations, directing visuospatial attention, and planning actions. However, recent studies suggest that right PPC may also be involved in processes that are more closely associated with our visual awareness as its activation level positively correlates with successful conscious change detection (Beck, D.M., Rees, G., Frith, C.D., & Lavie, N. (2001). Neural correlates of change detection and change blindness. Nature Neuroscience, 4, 645-650.). Furthermore, disruption of its activity increases the occurrences of change blindness, thus suggesting a causal role for right PPC in change detection (Beck, D.M., Muggleton, N., Walsh, V., & Lavie, N. (2006). Right parietal cortex plays a critical role in change blindness. Cerebral Cortex, 16, 712-717.). In the context of a 1-shot change detection paradigm, we applied transcranial magnetic stimulation (TMS) during different time intervals to elucidate the temporally precise involvement of PPC in change detection. While subjects attempted to detect changes between two image sets separated by a brief time interval, TMS was applied either during the presentation of picture 1 when subjects were encoding and maintaining information into visual short-term memory, or picture 2 when subjects were retrieving information relating to picture 1 and comparing it to picture 2. Our results show that change blindness occurred more often when TMS was applied during the viewing of picture 1, which implies that right PPC plays a crucial role in the processes of encoding and maintaining information in visual short-term memory. In addition, since our stimuli did not involve changes in spatial locations, our findings also support previous studies suggesting that PPC may be involved in the processes of encoding non-spatial visual information (Todd, J.J. & Marois, R. (2004). Capacity limit of visual short-term memory in human

Fabrication of P3HT/gold nanoparticle LB films by P3HT templating Langmuir monolayer

International Nuclear Information System (INIS)

Chen, Liang-Huei; Hsu, Wen-Ping; Chan, Han-Wen; Lee, Yuh-Lang

2014-01-01

Highlights: • Addition of ODA into the P3HT monolayer can significantly improve the dispersion ability of P3HT molecules. • The adsorption ability of the P3HT monolayer to the dispersed AuNPs can also be enhanced by the presence of ODA. - Abstract: Regioregular poly(3-hexyl thiophene) (rr-P3HT) and mixed P3HT/octadecyl amine (ODA) were used as template monolayers to adsorb the gold nanoparticles (AuNPs) dispersed in subphase. The behaviors of P3HT and P3HT/ODA monolayers were investigated by surface pressure area per molecule (π–A) isotherms, transmission electron microscopy (TEM) and atomic force microscopy (AFM). The experimental results show that P3HT does not form a homogeneous film and tends to aggregate at the air/water interface. Meanwhile, the amount of AuNPs adsorbed by the P3HT monolayers is low, attributable to the weak interaction between AuNPs and P3HT. By introduction of ODA molecules into the P3HT monolayer, the spreading of P3HT molecules at the air/water interface is improved and the aggregation of P3HT is significantly inhibited. A nearly uniform and homogeneously mixed P3HT/ODA monolayer can be obtained when 50% of ODA is introduced. It is also found that the introduction of ODA can significantly increase the adsorption of AuNPs. For the mixed monolayer with low ratio of ODA (P3HT/ODA = 1/0.2), a higher concentration of adsorbed AuNPs was observed on the corresponding monolayer. However, when the ODA/P3HT ratio increases to 1/1, the AuNPs tend to form three-dimensional (3D) aggregates and the AuNPs cannot distribute well as a homogeneous monolayer. This result is ascribed to the increasing hydrophobicity of the adsorbed AuNPs because of capping of more ODA molecules

AFM observation of OMVPE-grown ErP on InP substrates using a new organometal tris(ethylcyclopentadienyl)erbium (Er(EtCp)3)

International Nuclear Information System (INIS)

Akane, T.; Jinno, S.; Yang, Y.; Kuno, T.; Hirata, T.; Isogai, Y.; Watanabe, N.; Fujiwara, Y.; Nakamura, A.; Takeda, Y.

2003-01-01

ErP has been grown on InP(0 0 1) substrates by organometallic vapor phase epitaxy (OMVPE) using a new liquid organic Er source: tris(ethylcyclopentadienyl)erbium (Er(EtCp) 3 ). Morphological change of an ErP layer on InP(0 0 1) is investigated together with that of an overgrown capping InP layer. Optimum growth condition of InP causes islanding on over-monolayer-ErP. A relatively low overgrowth temperature of InP is a key factor for attaining complete capping coverage on ErP

Low energy 7Li(p,n)7Be neutron source (CANUTRON)

International Nuclear Information System (INIS)

Lone, M.A.; Ross, A.M.; Fraser, J.S.; Schriber, S.O.; Kushneriuk, S.A.; Selander, W.N.

1982-04-01

Characteristics of a neutron source based on the 7 Li(p,n) reaction at 2.5 MeV are investigated. It is shosn that with a 10-50 mA beam current this reaction provides a useful source for neutron radiography and other industrial applications

Low-frequency rTMS in the superior parietal cortex affects the working memory in horizontal axis during the spatial task performance.

Science.gov (United States)

Ribeiro, Jéssica Alves; Marinho, Francisco Victor Costa; Rocha, Kaline; Magalhães, Francisco; Baptista, Abrahão Fontes; Velasques, Bruna; Ribeiro, Pedro; Cagy, Mauricio; Bastos, Victor Hugo; Gupta, Daya; Teixeira, Silmar

2018-03-01

Spatial working memory has been extensively investigated with different tasks, treatments, and analysis tools. Several studies suggest that low frequency of the repetitive transcranial magnetic stimulation (rTMS) applied to the parietal cortex may influence spatial working memory (SWM). However, it is not yet known if after low-frequency rTMS applied to the superior parietal cortex, according to Pz electroencephalography (EEG) electrode, would change the orientation interpretation about the vertical and horizontal axes coordinates in an SWM task. The current study aims at filling this gap and obtains a better understanding of the low-frequency rTMS effect in SWM. In this crossover study, we select 20 healthy subjects in two conditions (control and 1-Hz rTMS). The subjects performed an SWM task with two random coordinates. Our results presented that low-frequency rTMS applied over the superior parietal cortex may influence the SWM to lead to a larger distance of axes interception point (p low-frequency rTMS over the superior parietal cortex (SPC) changes the SWM performance, and it has more predominance in horizontal axis.

Cascade production of Ar(3p54p) following electron bombardment

International Nuclear Information System (INIS)

Keto, J.W.; Kuo, C.

1981-01-01

We observe the time dependence of the fluorescence of Ar(3p 5 4p) following electron excitation of argon at pressures from 2--3000 Torr. The population of these levels at the lowest pressures observed is dominated by radiative cascade from Ar(3p 5 3d) and Ar(3p 5 5s). For argon states 4p'[1/2] 0 , 4p'[3/2] 2 , and 4p[1/2] 0 we find the cascade transitions can be identified and we assign radiative lifetimes of 61 +- 10, 69 +- 12, and 61 +- 6 nsec to 3d'[3/2] 1 , 3d'[5/2] 3 , and 3d[3/2] 1 , respectively. For cascade lifetimes to other levels, unique assignments cannot be made until values for forbidden electron impact cross sections to 3p 5 3d and 3p 5 5s can be obtained. The collisional quenching rates for the cascading levels are measured and found to explain the pressure dependence of the decay of Ar(3p 5 4p) over the full range of pressure except for Ar(3p 5 4p'[1/2] 1 ) which has a unique and interesting behavior at high pressures

Pressure effects on some argon spectral lines belonging to the 3p54p-3p5nd (n=5-7) transitions

International Nuclear Information System (INIS)

Wolnikowski, J.; Wawrzynski, J.; Bielski, A.; Szudy, J.

1987-01-01

Low pressure broadening and shift of four spectral lines of argon: 518.7 nm (3p 5 4p-3p 5 5d'), 522.1 nm (3p 5 4p-3p 5 7d), 549.6 nm (3p 5 4p-3p 5 6d) and 603.2 nm (3p 5 4p-3p 5 5d) have been investigated by means of a Fabry-Perot interferometer. The values of the pressure broadening and shift coefficients for argon-argon, argon-neon and argon-helium interactions in the low-current glow discharge conditions are determined. For all lines in the pure argon a red shift and in the argon-neon and argon-helium mixtures a blue shift has been found. The results cannot be interpreted on the basis of the existing simple interaction potential models within the framework of the adiabatic impact broadening theory. (orig.)

p3d – Python module for structural bioinformatics

Directory of Open Access Journals (Sweden)

Fufezan Christian

2009-08-01

Full Text Available Abstract Background High-throughput bioinformatic analysis tools are needed to mine the large amount of structural data via knowledge based approaches. The development of such tools requires a robust interface to access the structural data in an easy way. For this the Python scripting language is the optimal choice since its philosophy is to write an understandable source code. Results p3d is an object oriented Python module that adds a simple yet powerful interface to the Python interpreter to process and analyse three dimensional protein structure files (PDB files. p3d's strength arises from the combination of a very fast spatial access to the structural data due to the implementation of a binary space partitioning (BSP tree, b set theory and c functions that allow to combine a and b and that use human readable language in the search queries rather than complex computer language. All these factors combined facilitate the rapid development of bioinformatic tools that can perform quick and complex analyses of protein structures. Conclusion p3d is the perfect tool to quickly develop tools for structural bioinformatics using the Python scripting language.

Expression of a novel stress-inducible protein, sestrin 2, in rat glomerular parietal epithelial cells

Science.gov (United States)

Hamatani, Hiroko; Sakairi, Toru; Takahashi, Satoshi; Watanabe, Mitsuharu; Maeshima, Akito; Ohse, Takamoto; Pippin, Jeffery W.; Shankland, Stuart J.; Nojima, Yoshihisa

2014-01-01

Sestrin 2, initially identified as a p53 target protein, accumulates in cells exposed to stress and inhibits mammalian target of rapamycin (mTOR) signaling. In normal rat kidneys, sestrin 2 was selectively expressed in parietal epithelial cells (PECs), identified by the marker protein gene product 9.5. In adriamycin nephropathy, sestrin 2 expression decreased in PECs on day 14, together with increased expression of phosphorylated S6 ribosomal protein (P-S6RP), a downstream target of mTOR. Sestrin 2 expression was markedly decreased on day 42, coinciding with glomerulosclerosis and severe periglomerular fibrosis. In puromycin aminonucleoside nephropathy, decreased sestrin 2 expression, increased P-S6RP expression, and periglomerular fibrosis were observed on day 9, when massive proteinuria developed. These changes were transient and nearly normalized by day 28. In crescentic glomerulonephritis, sestrin 2 expression was not detected in cellular crescents, whereas P-S6RP increased. In conditionally immortalized cultured PECs, the forced downregulation of sestrin 2 by short hairpin RNA resulted in increased expression of P-S6RP and increased apoptosis. These data suggest that sestrin 2 is involved in PEC homeostasis by regulating the activity of mTOR. In addition, sestrin 2 could be a novel marker of PECs, and decreased expression of sestrin 2 might be a marker of PEC injury. PMID:25056347

Interaction between 14-3-3β and PrP influences the dimerization of 14-3-3 and fibrillization of PrP106-126.

Science.gov (United States)

Han, Jun; Song, Qin-Qin; Sun, Peng; Zhang, Jin; Wang, Xu; Song, Juan; Li, Gong-Qi; Liu, Ying-Hui; Mei, Guo-Yong; Shi, Qi; Tian, Chan; Chen, Cao; Gao, Chen; Zhao, Bo; Dong, Xiao-Ping

2014-02-01

Proteins of the 14-3-3 family are universal participate in multiple cellular processes. However, their exact role in the pathogenesis of prion diseases remains unclear. In this study, we proposed that human PrP was able to form molecular complex with 14-3-3β. The domains responsible for the interactions between PrP and 14-3-3β were mapped at the segments of amino acid (aa) residues 106-126 within PrP and aa 1-38 within 14-3-3β. Homology modeling revealed that the key aa residues for molecular interaction were D22 and D23 in 14-3-3β as well as K110 in PrP. Mutations in these aa residues inhibited the interaction between the two proteins in vitro. Our results also showed that recombinant PrP encouraged 14-3-3β dimer formation, whereas PrP106-126 peptide inhibited it. Recombinant 14-3-3β disaggregated the mature PrP106-126 fibrils in vitro. Moreover, the PrP-14-3-3 protein complexes were observed in the brain tissues of normal and scrapie agent 263K infected hamsters. Colocalization of PrP and 14-3-3 was seen in the cytoplasm of human neuroblastoma cell line SH-SY5Y, as well as human cervical cancer cell line HeLa transiently expressing full-length human PrP. Our current data suggest the neuroprotection of PrPC and neuron damage caused by PrPSc may be associated with their functions of 14-3-3 dimerization regulation. Copyright © 2013 Elsevier Ltd. All rights reserved.

3s--3p, 3p--3d, and 3d--4f transitions of sodiumlike ions

International Nuclear Information System (INIS)

Reader, J.; Kaufman, V.; Sugar, J.; Olof Ekberg, J.; Feldman, U.; Brown, C.M.; Seely, J.F.; Rowan, W.L.

1987-01-01

New measurements have been made for wavelengths of the 3s--3p, 3p--3d, and 3d--4f transitions of the sodiumlike ions Cu/sup 18+/, Zn/sup 19+/, Ga/sup 20+/, Ge/sup 21+/, As/sup 22+/, Se/sup 23+/, Br/sup 24+/, Kr/sup 25+/, Y/sup 28+/, Zr/sup 29+/, Nb/sup 30+/, Mo/sup 31+/, Ru/sup 33+/, Rh/sup 34+/, Pd/sup 35+/, Ag/sup 36+/, and Sn/sup 39+/. The measurements were made by photographing laser-produced plasmas and tokamak plasmas with grazing-incidence spectrographs. The energies of the transitions were also calculated with Dirac--Fock computer codes. By fitting the differences between the observed and calculated wave numbers to simple formulas, least-squares-fitted wavelengths for all sodiumlike ions from Ar 7+ to Xe/sup 43+/ were determined. The estimated uncertainty of the fitted wavelengths is +- 0.007 A, which makes them useful as reference values. The wavelengths range from 9 to 713 A

Distinct antigenic characteristics of murine parietal yolk sac laminin

DEFF Research Database (Denmark)

Wewer, U M; Tichy, D; Damjanov, A

1987-01-01

Two monoclonal antibodies (LAM-A and LAM-B) specific for laminin from normal and neoplastic parietal yolk sac (PYS) cells were produced in rats immunized with a mouse yolk sac carcinoma cell line. Both antibodies immunoprecipitated the 400,000- and 200,000-Da chains of laminin and reacted...... with purified PYS laminin in ELISA. LAM-A reacted with mouse and rat PYS laminin, whereas LAM-B reacted only with mouse PYS laminin. Formaldehyde- and methanol-fixed adult and fetal somatic tissues were immunohistochemically unreactive with either of the two antibodies. In acetone-fixed tissue sections, both...

Anatomical substrates of the alerting, orienting and executive control components of attention: focus on the posterior parietal lobe.

Directory of Open Access Journals (Sweden)

Xuntao Yin

Full Text Available Both neuropsychological and functional neuroimaging studies have identified that the posterior parietal lobe (PPL is critical for the attention function. However, the unique role of distinct parietal cortical subregions and their underlying white matter (WM remains in question. In this study, we collected both magnetic resonance imaging and diffusion tensor imaging (DTI data in normal participants, and evaluated their attention performance using attention network test (ANT, which could isolate three different attention components: alerting, orienting and executive control. Cortical thickness, surface area and DTI parameters were extracted from predefined PPL subregions and correlated with behavioural performance. Tract-based spatial statistics (TBSS was used for the voxel-wise statistical analysis. Results indicated structure-behaviour relationships on multiple levels. First, a link between the cortical thickness and WM integrity of the right inferior parietal regions and orienting performance was observed. Specifically, probabilistic tractography demonstrated that the integrity of WM connectivity between the bilateral inferior parietal lobules mediated the orienting performance. Second, the scores of executive control were significantly associated with the WM diffusion metrics of the right supramarginal gyrus. Finally, TBSS analysis revealed that alerting performance was significant correlated with the fractional anisotropy of local WM connecting the right thalamus and supplementary motor area. We conclude that distinct areas and features within PPL are associated with different components of attention. These findings could yield a more complete understanding of the nature of the PPL contribution to visuospatial attention.

Parietal and premotor cortices: activation reflects imitation accuracy during observation, delayed imitation and concurrent imitation.

Science.gov (United States)

Krüger, Britta; Bischoff, Matthias; Blecker, Carlo; Langhanns, Christine; Kindermann, Stefan; Sauerbier, Isabell; Reiser, Mathias; Stark, Rudolf; Munzert, Jörn; Pilgramm, Sebastian

2014-10-15

This study investigated whether activation within areas belonging to the action observation and imitation network reveals a linear relation to the subsequent accuracy of imitating a bimanual rhythmic movement measured via a motion capturing system. 20 participants were scanned with functional magnetic resonance imaging (fMRI) when asked to imitate observed bimanual movements either concurrently versus with a delay (2s) or simply to observe the movements without imitation. Results showed that action observation relates to activation within classic mirror-related areas. Activation patterns were more widespread when participants were asked to imitate the movement. During observation with concurrent imitation, activation in the left inferior parietal lobe (IPL) was associated negatively with imitation accuracy. During observation in the delayed imitation condition, higher subsequent imitation accuracy was coupled with higher activation in the right superior parietal lobe (SPL) and the left parietal operculum (POp). During the delayed imitation itself, a negative association between imitation accuracy and brain activation was revealed in the right ventral premotor cortex (vPMC). We conclude that the IPL is involved in online comparison and visuospatial attention processes during imitation, the SPL provides a kinesthetic blueprint during movement observation, the POp preserves body identity, and the vPMC recruits motor representations--especially when no concurrent visual guidance is possible. Copyright © 2014 Elsevier Inc. All rights reserved.

N-Heterocyclic Carbene Capture by Cytochrome P450 3A4

Science.gov (United States)

Jennings, Gareth K.; Ritchie, Caroline M.; Shock, Lisa S.; Lyons, Charles E.

2016-01-01

Cytochrome P450 3A4 (CYP3A4) is the dominant P450 enzyme involved in human drug metabolism, and its inhibition may result in adverse interactions or, conversely, favorably reduce the systemic elimination rates of poorly bioavailable drugs. Herein we describe a spectroscopic investigation of the interaction of CYP3A4 with N-methylritonavir, an analog of ritonavir, widely used as a pharmacoenhancer. In contrast to ritonavir, the binding affinity of N-methylritonavir for CYP3A4 is pH-dependent. At pH UV-visible spectroscopy binding studies with molecular fragments narrows the source of this pH dependence to its N-methylthiazolium fragment. The C2 proton of this group is acidic, and variable-pH resonance Raman spectroscopy tentatively assigns it a pKa of 7.4. Hence, this fragment of N-methylritonavir is expected to be readily deprotonated under physiologic conditions to yield a thiazol-2-ylidene, which is an N-heterocyclic carbene that has high-affinity for and is presumed to be subsequently captured by the heme iron. This mechanism is supported by time-dependent density functional theory with an active site model that accurately reproduces distinguishing features of the experimental UV-visible spectra of N-methylritonavir bound to CYP3A4. Finally, density functional theory calculations support that this novel interaction is as strong as the tightest-binding azaheterocycles found in P450 inhibitors and could offer new avenues for inhibitor development. PMID:27126611

Inactivation of Parietal Reach Region Affects Reaching But Not Saccade Choices in Internally Guided Decisions.

Science.gov (United States)

Christopoulos, Vassilios N; Bonaiuto, James; Kagan, Igor; Andersen, Richard A

2015-08-19

The posterior parietal cortex (PPC) has traditionally been considered important for awareness, spatial perception, and attention. However, recent findings provide evidence that the PPC also encodes information important for making decisions. These findings have initiated a running argument of whether the PPC is critically involved in decision making. To examine this issue, we reversibly inactivated the parietal reach region (PRR), the area of the PPC that is specialized for reaching movements, while two monkeys performed a memory-guided reaching or saccade task. The task included choices between two equally rewarded targets presented simultaneously in opposite visual fields. Free-choice trials were interleaved with instructed trials, in which a single cue presented in the peripheral visual field defined the reach and saccade target unequivocally. We found that PRR inactivation led to a strong reduction of contralesional choices, but only for reaches. On the other hand, saccade choices were not affected by PRR inactivation. Importantly, reaching and saccade movements to single instructed targets remained largely intact. These results cannot be explained as an effector-nonspecific deficit in spatial attention or awareness, since the temporary "lesion" had an impact only on reach choices. Hence, the PPR is a part of a network for reach decisions and not just reach planning. There has been an ongoing debate on whether the posterior parietal cortex (PPC) represents only spatial awareness, perception, and attention or whether it is also involved in decision making for actions. In this study we explore whether the parietal reach region (PRR), the region of the PPC that is specialized for reaches, is involved in the decision process. We inactivated the PRR while two monkeys performed reach and saccade choices between two targets presented simultaneously in both hemifields. We found that inactivation affected only the reach choices, while leaving saccade choices intact

Integration of Visual and Proprioceptive Limb Position Information in Human Posterior Parietal, Premotor, and Extrastriate Cortex.

Science.gov (United States)

Limanowski, Jakub; Blankenburg, Felix

2016-03-02

The brain constructs a flexible representation of the body from multisensory information. Previous work on monkeys suggests that the posterior parietal cortex (PPC) and ventral premotor cortex (PMv) represent the position of the upper limbs based on visual and proprioceptive information. Human experiments on the rubber hand illusion implicate similar regions, but since such experiments rely on additional visuo-tactile interactions, they cannot isolate visuo-proprioceptive integration. Here, we independently manipulated the position (palm or back facing) of passive human participants' unseen arm and of a photorealistic virtual 3D arm. Functional magnetic resonance imaging (fMRI) revealed that matching visual and proprioceptive information about arm position engaged the PPC, PMv, and the body-selective extrastriate body area (EBA); activity in the PMv moreover reflected interindividual differences in congruent arm ownership. Further, the PPC, PMv, and EBA increased their coupling with the primary visual cortex during congruent visuo-proprioceptive position information. These results suggest that human PPC, PMv, and EBA evaluate visual and proprioceptive position information and, under sufficient cross-modal congruence, integrate it into a multisensory representation of the upper limb in space. The position of our limbs in space constantly changes, yet the brain manages to represent limb position accurately by combining information from vision and proprioception. Electrophysiological recordings in monkeys have revealed neurons in the posterior parietal and premotor cortices that seem to implement and update such a multisensory limb representation, but this has been difficult to demonstrate in humans. Our fMRI experiment shows that human posterior parietal, premotor, and body-selective visual brain areas respond preferentially to a virtual arm seen in a position corresponding to one's unseen hidden arm, while increasing their communication with regions conveying visual

Altered Parietal Activation during Non-symbolic Number Comparison in Children with Prenatal Alcohol Exposure

Directory of Open Access Journals (Sweden)

Keri J. Woods

2018-01-01

Full Text Available Number processing is a cognitive domain particularly sensitive to prenatal alcohol exposure, which relies on intact parietal functioning. Alcohol-related alterations in brain activation have been found in the parietal lobe during symbolic number processing. However, the effects of prenatal alcohol exposure on the neural correlates of non-symbolic number comparison and the numerical distance effect have not been investigated. Using functional magnetic resonance imaging (fMRI, we examined differences in brain activation associated with prenatal alcohol exposure in five parietal regions involved in number processing during a non-symbolic number comparison task with varying degrees of difficulty. fMRI results are presented for 27 Cape Colored children (6 fetal alcohol syndome (FAS/partial FAS, 5 heavily exposed (HE non-sydromal, 16 controls; mean age ± SD = 11.7 ± 1.1 years. Fetal alcohol exposure was assessed by interviewing mothers using a timeline follow-back approach. Separate subject analyses were performed in each of five regions of interest, bilateral horizontal intraparietal sulci (IPS, bilateral posterior superior parietal lobules (PSPL, and left angular gyrus (left AG, using the general linear model with predictors for number comparison and difficulty level. Mean percent signal change for each predictor was extracted for each subject for each region to examine group differences and associations with continuous measures of alcohol exposure. Although groups did not differ in performance, controls activated the right PSPL more during non-symbolic number comparison than exposed children, but this was not significant after controlling for maternal smoking, and the right IPS more than children with fetal alcohol syndrome (FAS or partial FAS. More heavily exposed children recruited the left AG to a greater extent as task difficulty increased, possibly to compensate, in part, for impairments in function in the PSPL and IPS. Notably, in non

"Do-It-Yourself" reliable pH-stat device by using open-source software, inexpensive hardware and available laboratory equipment

Science.gov (United States)

Kragic, Rastislav; Kostic, Mirjana

2018-01-01

In this paper, we present the construction of a reliable and inexpensive pH stat device, by using open-source “OpenPhControl” software, inexpensive hardware (a peristaltic and a syringe pump, Arduino, a step motor…), readily available laboratory devices: a pH meter, a computer, a webcam, and some 3D printed parts. We provide a methodology for the design, development and test results of each part of the device, as well as of the entire system. In addition to dosing reagents by means of a low-cost peristaltic pump, we also present carefully controlled dosing of reagents by an open-source syringe pump. The upgrading of the basic open-source syringe pump is given in terms of pump control and application of a larger syringe. In addition to the basic functions of pH stat, i.e. pH value measurement and maintenance, an improvement allowing the device to be used for potentiometric titration has been made as well. We have demonstrated the device’s utility when applied for cellulose fibers oxidation with 2,2,6,6-tetramethylpiperidine-1-oxyl radical, i.e. for TEMPO-mediated oxidation. In support of this, we present the results obtained for the oxidation kinetics, the consumption of added reagent and experimental repeatability. Considering that the open-source scientific tools are available to everyone, and that researchers can construct and adjust the device according to their needs, as well as, that the total cost of the open-source pH stat device, excluding the existing laboratory equipment (pH meter, computer and glossary) was less than 150 EUR, we believe that, at a small fraction of the cost of available commercial offers, our open-source pH stat can significantly improve experimental work where the use of pH stat is necessary. PMID:29509793

"Do-It-Yourself" reliable pH-stat device by using open-source software, inexpensive hardware and available laboratory equipment.

Science.gov (United States)

Milanovic, Jovana Z; Milanovic, Predrag; Kragic, Rastislav; Kostic, Mirjana

2018-01-01

In this paper, we present the construction of a reliable and inexpensive pH stat device, by using open-source "OpenPhControl" software, inexpensive hardware (a peristaltic and a syringe pump, Arduino, a step motor…), readily available laboratory devices: a pH meter, a computer, a webcam, and some 3D printed parts. We provide a methodology for the design, development and test results of each part of the device, as well as of the entire system. In addition to dosing reagents by means of a low-cost peristaltic pump, we also present carefully controlled dosing of reagents by an open-source syringe pump. The upgrading of the basic open-source syringe pump is given in terms of pump control and application of a larger syringe. In addition to the basic functions of pH stat, i.e. pH value measurement and maintenance, an improvement allowing the device to be used for potentiometric titration has been made as well. We have demonstrated the device's utility when applied for cellulose fibers oxidation with 2,2,6,6-tetramethylpiperidine-1-oxyl radical, i.e. for TEMPO-mediated oxidation. In support of this, we present the results obtained for the oxidation kinetics, the consumption of added reagent and experimental repeatability. Considering that the open-source scientific tools are available to everyone, and that researchers can construct and adjust the device according to their needs, as well as, that the total cost of the open-source pH stat device, excluding the existing laboratory equipment (pH meter, computer and glossary) was less than 150 EUR, we believe that, at a small fraction of the cost of available commercial offers, our open-source pH stat can significantly improve experimental work where the use of pH stat is necessary.

Resonant photoemission study on La0.7Ca0.3MnO3 using Indus-1 synchrotron source

International Nuclear Information System (INIS)

Sagdeo, P.R.; Choudhary, R.J.; Phase, D.M.

2008-01-01

The electronic valance band structure of pulsed laser deposited La 0.7 Ca 0.3 MnO 3 thin film has been investigated by resonant photoelectron spectroscopy using CSR beamline (BL-2) on Indus-1 synchrotron radiation source. The valance band spectra were measured at room temperature with the photon energy ranging from 40 eV to 60 eV. The contribution of Mn-3d to the valance band was determined using resonant photo-electron intensity near Mn3p-3d threshold. (author)

Bio-plastic (P-3HB-co-3HV) from Bacillus circulans (MTCC 8167) and its biodegradation.

Science.gov (United States)

Phukon, Pinkee; Saikia, Jyoti Prasad; Konwar, Bolin Kumar

2012-04-01

Polyhydroxyalkanoates (PHAs) are naturally occurring polyesters synthesized by bacteria for carbon and energy storage and it has commercial potential as bioplastic. The bacterial species Bacillus circulans MTCC 8167, isolated from crude oil contaminated soil, can efficiently produce medium chain length polyhydroxyalkanoates (P-3HB-co-3HV) from cheap carbon sources like dextrose. The molecular mass of P-3HB-co-3HV was reported as 5.1×10(4)Da with polydispersity index of 1.21 by gel permeation chromatography. In the present investigation different bacteria and fungi species were used for testing the biodegradability of the extracted polymer. The FTIR spectra of the biodegraded PHBV film showed a decrease in the peak from 1735 cm(-1) (untreated film) to 1675 cm(-1), and disappearance of a peak present in the control at 2922 cm(-1) indicating the breakdown of ester (>C=O) or O-R group and -C=H bond, respectively. From biodegradability testing, the tested microorganisms were found to have decisive contribution to the biodegradation of P-3HB-co-3HV polymer. Copyright © 2011 Elsevier B.V. All rights reserved.

Identification of miR-508-3p and miR-509-3p that are associated with cell invasion and migration and involved in the apoptosis of renal cell carcinoma

International Nuclear Information System (INIS)

Zhai, Qingna; Zhou, Liang; Zhao, Chunjuan; Wan, Jun; Yu, Zhendong; Guo, Xin; Qin, Jie; Chen, Jing; Lu, Ruijing

2012-01-01

Highlights: ► Previous method was the second-generation sequencing technology. ► miR-508-3p and miR-509-3p were significantly down-regulated in RCC tissues. ► They can inhibit cell proliferation and migration and promote cell apoptosis. ► The expression of miR-508-3p was significantly decreased in RCC patients plasma. ► miR-508-3p may be a novel diagnostic marker of RCC. -- Abstract: MicroRNAs (miRNAs) have emerged as powerful regulators of multiple processes linked to human cancer, including cell apoptosis, proliferation and migration, suggesting that the regulation of miRNA function could play a critical role in cancer progression. Recent studies have found that human serum/plasma contains stably expressed miRNAs. If they prove indicative of disease states, miRNAs measured from peripheral blood samples may be a source for routine clinical detection of cancer. Our studies showed that both miR-508-3p and miR-509-3p were down-regulated in renal cancer tissues. The level of miR-508-3p but not miR-509-3p in renal cell carcinoma (RCC) patient plasma demonstrated significant differences from that in control plasma. In addition, the overexpression of miR-508-3p and miR-509-3p suppressed the proliferation of RCC cells (786-0), induced cell apoptosis and inhibited cell migration in vitro. Our data demonstrated that miR-508-3p and miR-509-3p played an important role as tumor suppressor genes during tumor formation and that they may serve as novel diagnostic markers for RCC.

Quenching of I(2P1/2) by O3 and O(3P).

Science.gov (United States)

Azyazov, Valeriy N; Antonov, Ivan O; Heaven, Michael C

2007-04-26

Oxygen-iodine lasers that utilize electrical or microwave discharges to produce singlet oxygen are currently being developed. The discharge generators differ from conventional chemical singlet oxygen generators in that they produce significant amounts of atomic oxygen. Post-discharge chemistry includes channels that lead to the formation of ozone. Consequently, removal of I(2P1/2) by O atoms and O3 may impact the efficiency of discharge driven iodine lasers. In the present study, we have measured the rate constants for quenching of I(2P1/2) by O(3P) atoms and O3 using pulsed laser photolysis techniques. The rate constant for quenching by O3, (1.8 +/- 0.4) x 10(-12) cm3 s-1, was found to be a factor of 5 smaller than the literature value. The rate constant for quenching by O(3P) was (1.2 +/- 0.2) x 10(-11) cm3 s-1.

Population of the 3P2,1,0 fine-structure states in the 3s and 3p photoionization of atomic chlorine

International Nuclear Information System (INIS)

Krause, M.O.; Caldwell, C.D.; Whitfield, S.B.; de Lange, C.A.; van der Meulen, P.

1993-01-01

In a high-resolution photoelectron-spectrometry study of the photoionization of chlorine atoms in both the 3s and 3p subshells, we were able to resolve contributions from ionic states with specific J values and measure the relative populations of these fine-structure components. Our photoelectron spectra, recorded at hν=29.2 eV, give ratios of 3 P 2 : 3 P 1 : 3 P 0 =100:40.59.5 for 3p photoionization and 3 P 2 : 3 P 1 =100:31 for 3s photoionization. While the results for 3p ionization are in accord with predictions based on a simple geometric analysis, the contribution of the 3 P 1 state in 3s photoionization is larger than that predicted by this simple model. The geometric predictions are also compared with results from a similar measurement of the population of the 4p -1 ( 3 P J ) states produced in the 4p ionization of Br and with earlier work on the production of 3 D 2,1,0 states in d-shell photoionization of Cu and Ag

A theoretical study of the H-abstraction reactions from HOI by moist air radiolytic products (H, OH, and O (3P)) and iodine atoms (2P(3/2)).

Science.gov (United States)

Hammaecher, Catherine; Canneaux, Sébastien; Louis, Florent; Cantrel, Laurent

2011-06-23

The rate constants of the reactions of HOI molecules with H, OH, O ((3)P), and I ((2)P(3/2)) atoms have been estimated over the temperature range 300-2500 K using four different levels of theory. Geometry optimizations and vibrational frequency calculations are performed using MP2 methods combined with two basis sets (cc-pVTZ and 6-311G(d,p)). Single-point energy calculations are performed with the highly correlated ab initio coupled cluster method in the space of single, double, and triple (pertubatively) electron excitations CCSD(T) using the cc-pVTZ, cc-pVQZ, 6-311+G(3df,2p), and 6-311++G(3df,3pd) basis sets. Reaction enthalpies at 0 K were calculated at the CCSD(T)/cc-pVnZ//MP2/cc-pVTZ (n = T and Q), CCSD(T)/6-311+G(3df,2p)//MP2/6-311G(d,p), and CCSD(T)/6-311++G(3df,3pd)//MP2/6-311G(d,p) levels of theory and compared to the experimental values taken from the literature. Canonical transition-state theory with an Eckart tunneling correction is used to predict the rate constants as a function of temperature. The computational procedure has been used to predict rate constants for H-abstraction elementary reactions because there are actually no literature data to which the calculated rate constants can be directly compared. The final objective is to implement kinetics of gaseous reactions in the ASTEC (accident source term evaluation code) program to improve speciation of fission products, which can be transported along the reactor coolant system (RCS) of a pressurized water reactor (PWR) in the case of a severe accident.

Expression of UV-sensitive parapinopsin in the iguana parietal eyes and its implication in UV-sensitivity in vertebrate pineal-related organs.

Science.gov (United States)

Wada, Seiji; Kawano-Yamashita, Emi; Koyanagi, Mitsumasa; Terakita, Akihisa

2012-01-01

The pineal-related organs of lower vertebrates have the ability to discriminate different wavelengths of light. This wavelength discrimination is achieved through antagonistic light responses to UV or blue and visible light. Previously, we demonstrated that parapinopsin underlies the UV reception in the lamprey pineal organ and identified parapinopsin genes in teleosts and frogs of which the pineal-related organs were reported to discriminate light. In this study, we report the first identification of parapinopsin in the reptile lineage and show its expression in the parietal eye of the green iguana. Spectroscopic analysis revealed that iguana parapinopsin is a UV-sensitive pigment, similar to lamprey parapinopsin. Interestingly, immunohistochemical analyses using antibodies specific to parapinopsin and parietopsin, a parietal eye green-sensitive pigment, revealed that parapinopsin and parietopsin are colocalized in the outer segments of the parietal eye photoreceptor cells in iguanas. These results strongly suggest that parapinopsin underlies the wavelength discrimination involving UV reception in the iguana parietal eye. The current findings support the idea that parapinopsin is a common photopigment underlying the UV-sensitivity in wavelength discrimination of the pineal-related organs found from lampreys to reptiles.

Expression of UV-Sensitive Parapinopsin in the Iguana Parietal Eyes and Its Implication in UV-Sensitivity in Vertebrate Pineal-Related Organs

Science.gov (United States)

Wada, Seiji; Kawano-Yamashita, Emi; Koyanagi, Mitsumasa; Terakita, Akihisa

2012-01-01

The pineal-related organs of lower vertebrates have the ability to discriminate different wavelengths of light. This wavelength discrimination is achieved through antagonistic light responses to UV or blue and visible light. Previously, we demonstrated that parapinopsin underlies the UV reception in the lamprey pineal organ and identified parapinopsin genes in teleosts and frogs of which the pineal-related organs were reported to discriminate light. In this study, we report the first identification of parapinopsin in the reptile lineage and show its expression in the parietal eye of the green iguana. Spectroscopic analysis revealed that iguana parapinopsin is a UV-sensitive pigment, similar to lamprey parapinopsin. Interestingly, immunohistochemical analyses using antibodies specific to parapinopsin and parietopsin, a parietal eye green-sensitive pigment, revealed that parapinopsin and parietopsin are colocalized in the outer segments of the parietal eye photoreceptor cells in iguanas. These results strongly suggest that parapinopsin underlies the wavelength discrimination involving UV reception in the iguana parietal eye. The current findings support the idea that parapinopsin is a common photopigment underlying the UV-sensitivity in wavelength discrimination of the pineal-related organs found from lampreys to reptiles. PMID:22720013

Expression of UV-sensitive parapinopsin in the iguana parietal eyes and its implication in UV-sensitivity in vertebrate pineal-related organs.

Directory of Open Access Journals (Sweden)

Seiji Wada

Full Text Available The pineal-related organs of lower vertebrates have the ability to discriminate different wavelengths of light. This wavelength discrimination is achieved through antagonistic light responses to UV or blue and visible light. Previously, we demonstrated that parapinopsin underlies the UV reception in the lamprey pineal organ and identified parapinopsin genes in teleosts and frogs of which the pineal-related organs were reported to discriminate light. In this study, we report the first identification of parapinopsin in the reptile lineage and show its expression in the parietal eye of the green iguana. Spectroscopic analysis revealed that iguana parapinopsin is a UV-sensitive pigment, similar to lamprey parapinopsin. Interestingly, immunohistochemical analyses using antibodies specific to parapinopsin and parietopsin, a parietal eye green-sensitive pigment, revealed that parapinopsin and parietopsin are colocalized in the outer segments of the parietal eye photoreceptor cells in iguanas. These results strongly suggest that parapinopsin underlies the wavelength discrimination involving UV reception in the iguana parietal eye. The current findings support the idea that parapinopsin is a common photopigment underlying the UV-sensitivity in wavelength discrimination of the pineal-related organs found from lampreys to reptiles.

Association between auditory P300, psychopathology, and memory function in drug-naïve schizophrenia.

Science.gov (United States)

Chang, Wei-Hung; Chen, Kao-Chin; Yang, Yen-Kuang; Chen, Po-See; Lu, Ru-Band; Yeh, Tzung-Lieh; Wang, Carol Sheei-Meei; Lee, I-Hui

2014-03-01

The aim of this study was to explore memory deficits and psychopathology and their relationships with P300 in drug-naïve patients with schizophrenia. The Positive and Negative Syndrome Scale (PANSS) and the Wechsler Memory Scale-Revised were administered. Auditory event-related potentials elicited by an oddball paradigm were obtained. After controlling for age, sex, the results showed a statistically significant negative correlation between the total PANSS score and P300 amplitude at the parietal position (r = -0.66, p visual memory was significantly positively correlated with P300 amplitude at the parietal position (r = 0.67, p memory decompensation in P300 among drug-naïve patients with schizophrenia may be considered, and the compensatory or Default Model Network might be a possible explanation of this association. Copyright © 2013. Published by Elsevier B.V.

Spatial summation in macaque parietal area 7a follows a winner-take-all rule

NARCIS (Netherlands)

Oleksiak, Anna; Klink, P. Christiaan; Postma, Albert; van der Ham, Ineke J.M.; Lankheet, Martin J.M.; van Wezel, Richard Jack Anton

2011-01-01

While neurons in posterior parietal cortex have been found to signal the presence of a salient stimulus among multiple items in a display, spatial summation within their receptive field in the absence of an attentional bias has never been investigated. This information, however, is indispensable

Frontal parietal control network regulates the anti-correlated default and dorsal attention networks.

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Gao, Wei; Lin, Weili

2012-01-01

Recent reports demonstrate the anti-correlated behaviors between the default (DF) and the dorsal attention (DA) networks. We aimed to investigate the roles of the frontal parietal control (FPC) network in regulating the two anti-correlated networks through three experimental conditions, including resting, continuous self-paced/attended sequential finger tapping (FT), and natural movie watching (MW), respectively. The two goal-directed tasks were chosen to engage either one of the two competing networks-FT for DA whereas MW for default. We hypothesized that FPC will selectively augment/suppress either network depending on how the task targets the specific network; FPC will positively correlate with the target network, but negatively correlate with the network anti-correlated with the target network. We further hypothesized that significant causal links from FPC to both DA and DF are present during all three experimental conditions, supporting the initiative regulating role of FPC over the two opposing systems. Consistent with our hypotheses, FPC exhibited a significantly higher positive correlation with DA (P = 0.0095) whereas significantly more negative correlation with default (P = 0.0025) during FT when compared to resting. Completely opposite to that observed during FT, the FPC was significantly anti-correlated with DA (P = 2.1e-6) whereas positively correlated with default (P = 0.0035) during MW. Furthermore, extensive causal links from FPC to both DA and DF were observed across all three experimental states. Together, our results strongly support the notion that the FPC regulates the anti-correlated default and DA networks. Copyright © 2011 Wiley Periodicals, Inc.

(3)He pO2 mapping is limited by delayed-ventilation and diffusion in chronic obstructive pulmonary disease.

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Marshall, Helen; Parra-Robles, Juan; Deppe, Martin H; Lipson, David A; Lawson, Rod; Wild, Jim M

2014-03-01

Lung pO2 mapping with (3)He MRI assumes that the sources of signal decay with time during a breath-hold are radiofrequency depolarization and oxygen-dependent T1 relaxation, but the method is sensitive to other sources of spatio-temporal signal change such as diffusion. The purpose of this work was to assess the use of (3)He pO2 mapping in patients with chronic obstructive pulmonary disease. Ten patients with moderate to severe chronic obstructive pulmonary disease were scanned with a 3D single breath-hold pO2 mapping sequence. Images showed signal increasing over time in some lung regions due to delayed ventilation during breath-hold. Regions of physically unrealistic negative pO2 values were seen in all patients, and regional mean pO2 values of -0.3 bar were measured in the two patients most affected by delayed ventilation (where mean time to signal onset was 3-4 s). Movement of gas within the lungs during breath-hold causes regional changes in signal over time that are not related to oxygen concentration, leading to erroneous pO2 measurements using the linear oxygen-dependent signal decay model. These spatio-temporal sources of signal change cannot be reliably separated at present, making pO2 mapping using this methodology unreliable in chronic obstructive pulmonary disease patients with significant bullous emphysema or delayed ventilation. Copyright © 2013 Wiley Periodicals, Inc.

Improving ideomotor limb apraxia by electrical stimulation of the left posterior parietal cortex.

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Bolognini, Nadia; Convento, Silvia; Banco, Elisabetta; Mattioli, Flavia; Tesio, Luigi; Vallar, Giuseppe

2015-02-01

Limb apraxia, a deficit of planning voluntary gestures, is most frequently caused by damage to the left hemisphere, where, according to an influential neurofunctional model, gestures are planned, before being executed through the motor cortex of the hemisphere contralateral to the acting hand. We used anodal transcranial direct current stimulation delivered to the left posterior parietal cortex (PPC), the right motor cortex (M1), and a sham stimulation condition, to modulate the ability of six left-brain-damaged patients with ideomotor apraxia, and six healthy control subjects, to imitate hand gestures, and to perform skilled hand movements using the left hand. Transcranial direct current stimulation delivered to the left PPC reduced the time required to perform skilled movements, and planning, but not execution, times in imitating gestures, in both patients and controls. In patients, the amount of decrease of planning times brought about by left PPC transcranial direct current stimulation was influenced by the size of the parietal lobe damage, with a larger parietal damage being associated with a smaller improvement. Of interest from a clinical perspective, left PPC stimulation also ameliorated accuracy in imitating hand gestures in patients. Instead, transcranial direct current stimulation to the right M1 diminished execution, but not planning, times in both patients and healthy controls. In conclusion, by using a transcranial stimulation approach, we temporarily improved ideomotor apraxia in the left hand of left-brain-damaged patients, showing a role of the left PPC in planning gestures. This evidence opens up novel perspectives for the use of transcranial direct current stimulation in the rehabilitation of limb apraxia. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Observational learning of new movement sequences is reflected in fronto-parietal coherence.

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Jurjen van der Helden

Full Text Available Mankind is unique in her ability for observational learning, i.e. the transmission of acquired knowledge and behavioral repertoire through observation of others' actions. In the present study we used electrophysiological measures to investigate brain mechanisms of observational learning. Analysis investigated the possible functional coupling between occipital (alpha and motor (mu rhythms operating in the 10 Hz frequency range for translating "seeing" into "doing". Subjects observed movement sequences consisting of six consecutive left or right hand button presses directed at one of two target-buttons for subsequent imitation. Each movement sequence was presented four times, intervened by short pause intervals for sequence rehearsal. During a control task subjects observed the same movement sequences without a requirement for subsequent reproduction. Although both alpha and mu rhythms desynchronized during the imitation task relative to the control task, modulations in alpha and mu power were found to be largely independent from each other over time, arguing against a functional coupling of alpha and mu generators during observational learning. This independence was furthermore reflected in the absence of coherence between occipital and motor electrodes overlaying alpha and mu generators. Instead, coherence analysis revealed a pair of symmetric fronto-parietal networks, one over the left and one over the right hemisphere, reflecting stronger coherence during observation of movements than during pauses. Individual differences in fronto-parietal coherence were furthermore found to predict imitation accuracy. The properties of these networks, i.e. their fronto-parietal distribution, their ipsilateral organization and their sensitivity to the observation of movements, match closely with the known properties of the mirror neuron system (MNS as studied in the macaque brain. These results indicate a functional dissociation between higher order areas for

El arte parietal, espejo de las sociedades paleolíticas

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Georges SAUVET

2009-12-01

Full Text Available RESUMEN: El presente trabajo aboga por un estudio del arte parietal como instrumento del conocimiento de la geografía humana de las sociedades de cazadores y de la evolución de sus redes de alianza, durante el Paleolítico superior. Tomando como ejemplo el componente figurativo de este arte y un amplio corpus de 3981 figuras procedentes de 154 yacimientos franceses y españoles, se demuestra que las asociaciones entre especies animales diferentes obedecen a reglas simples y coherentes, que se dejan fácilmente exprimir por un modelo formal. El análisis de doce sub-conjuntos sincrónicos y diacrónicos evidencia la movilidad de las connexiones interregionales (por ejemplo el desarrollo del Solutrense cantábrico en relación con los centros peninsulares y con escaso contacto con el sudoeste francés, al contrario de la situación que prevalece durante el Magdaleniense medio-superior. Sin embargo conforta la idea que las variaciones regionales operan dentro de un sistema de pensamiento religioso relativamente estable. Una segunda fase del trabajo se propone describir la estructuración del arte parietal a un nivel mucho más fino, teniendo en cuenta la diversidad formal de cada figura y sus relaciones topológicas con las demás. Una larga base de datos está en curso de elaboración para su tratamiento con las técnicas de "extracción de conocimiento" (Knowledge Discovery in Databases. Unos resultados preliminares dejan esperar que una base de datos de este tipo servirá el objetivo y proporcionará une visión más precisa y segura de la historia de los pueblos paleolíticos, dado que la fuente del estilo propio de cada grupo debe buscarse en la construcción gráfica de paneles complejos.ABSTRACT: This paper pleads in favour of the study of parietal art as a means to investigate the human geography of palaeolithic hunter-gatherers in Europe and the evolution of their alliance networks. Taking the example of the figurative component of Rock

Parietal Lobe Volume Deficits in Adolescents with Schizophrenia and Adolescents with Cannabis Use Disorders

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Kumra, Sanjiv; Robinson, Paul; Tambyraja, Rabindra; Jensen, Daniel; Schimunek, Caroline; Houri, Alaa; Reis, Tiffany; Lim, Kelvin

2012-01-01

Objective: In early-onset schizophrenia (EOS), the earliest structural brain volumetric abnormalities appear in the parietal cortices. Early exposure to cannabis may represent an environmental risk factor for developing schizophrenia. This study characterized cerebral cortical gray matter structure in adolescents in regions of interest (ROIs) that…

Sea cucumber and blue mussel: new sources of phospholipid enriched omega-3 fatty acids with a potential role in 3T3-L1 adipocyte metabolism.

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Vaidya, Hitesh; Cheema, Sukhinder K

2014-12-01

Omega (n)-3 polyunsaturated fatty acids (PUFA), namely docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are known to reduce the risk of insulin resistance and ameliorate obesity-associated disorders. DHA and EPA structured in the phospholipid form possess superior biological effects compared to the triglyceride form available in fish oil. In this study, we have found that sea cucumber (SC) and blue mussel (BM) from Newfoundland and Labrador are rich sources of n-3 PUFA structured in the phospholipid form. Treatment with SC and BM methanolic extracts (250 and 100 μg mL(-1), respectively) significantly (p triglyceride accumulation in 3T3-L1 adipocytes, along with an increase in the mRNA expression of the peroxisome proliferator-activated receptor-γ (37 and 39%, respectively) and adiponectin (57 and 56%, respectively) compared with control cells (p triglyceride accumulation in 3T3-L1 cells as opposed to an increase in triglyceride accumulation at lower concentrations. This was due to inhibition of acetyl-CoA carboxylase-1 and SREBP-1 mRNA expression compared to control cells (p triglyceride accumulation at higher concentrations is not due to breakdown and release of fat. This is the first report to show that SC and BM are new sources of phospholipid bonded n-3 PUFA, with the potential to target insulin resistance and obesity.

Deficits in visual search for conjunctions of motion and form after parietal damage but with spared hMT+/V5.

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Dent, Kevin; Lestou, Vaia; Humphreys, Glyn W

2010-02-01

It has been argued that area hMT+/V5 in humans acts as a motion filter, enabling targets defined by a conjunction of motion and form to be efficiently selected. We present data indicating that (a) damage to parietal cortex leads to a selective problem in processing motion-form conjunctions, and (b) that the presence of a structurally and functional intact hMT+/V5 is not sufficient for efficient search for motion-form conjunctions. We suggest that, in addition to motion-processing areas (e.g., hMT+/V5), the posterior parietal cortex is necessary for efficient search with motion-form conjunctions, so that damage to either brain region may bring about deficits in search. We discuss the results in terms of the involvement of the posterior parietal cortex in the top-down guidance of search or in the binding of motion and form information.

Timing-dependent modulation of the posterior parietal cortex-primary motor cortex pathway by sensorimotor training

DEFF Research Database (Denmark)

Karabanov, Anke Ninija; Jin, Seung-Hyun; Joutsen, Atte

2012-01-01

at baseline and at four time points (0, 30, 60, and 180 min) after training. For EEG, task-related power and coherence were calculated for early and late training phases. The conditioned MEP was facilitated at a 2-ms conditioning-test interval before training. However, facilitation was abolished immediately...... following training, but returned to baseline at subsequent time points. Regional EEG activity and interregional connectivity between PPC and M1 showed an initial increase during early training followed by a significant decrease in the late phases. The findings indicate that parietal-motor interactions......Interplay between posterior parietal cortex (PPC) and ipsilateral primary motor cortex (M1) is crucial during execution of movements. The purpose of the study was to determine whether functional PPC-M1 connectivity in humans can be modulated by sensorimotor training. Seventeen participants...

Hippocampal and posterior parietal contributions to developmental increases in visual short-term memory capacity.

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von Allmen, David Yoh; Wurmitzer, Karoline; Klaver, Peter

2014-10-01

Developmental increases in visual short-term memory (VSTM) capacity have been associated with changes in attention processing limitations and changes in neural activity within neural networks including the posterior parietal cortex (PPC). A growing body of evidence suggests that the hippocampus plays a role in VSTM, but it is unknown whether the hippocampus contributes to the capacity increase across development. We investigated the functional development of the hippocampus and PPC in 57 children, adolescents and adults (age 8-27 years) who performed a visuo-spatial change detection task. A negative relationship between age and VSTM related activity was found in the right posterior hippocampus that was paralleled by a positive age-activity relationship in the right PPC. In the posterior hippocampus, VSTM related activity predicted individual capacity in children, whereas neural activity in the right anterior hippocampus predicted individual capacity in adults. The findings provide first evidence that VSTM development is supported by an integrated neural network that involves hippocampal and posterior parietal regions.

Emotion unfolded by motion: a role for parietal lobe in decoding dynamic facial expressions.

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Sarkheil, Pegah; Goebel, Rainer; Schneider, Frank; Mathiak, Klaus

2013-12-01

Facial expressions convey important emotional and social information and are frequently applied in investigations of human affective processing. Dynamic faces may provide higher ecological validity to examine perceptual and cognitive processing of facial expressions. Higher order processing of emotional faces was addressed by varying the task and virtual face models systematically. Blood oxygenation level-dependent activation was assessed using functional magnetic resonance imaging in 20 healthy volunteers while viewing and evaluating either emotion or gender intensity of dynamic face stimuli. A general linear model analysis revealed that high valence activated a network of motion-responsive areas, indicating that visual motion areas support perceptual coding for the motion-based intensity of facial expressions. The comparison of emotion with gender discrimination task revealed increased activation of inferior parietal lobule, which highlights the involvement of parietal areas in processing of high level features of faces. Dynamic emotional stimuli may help to emphasize functions of the hypothesized 'extended' over the 'core' system for face processing.

Temporo-Parietal Junction Activity in Theory-of-Mind Tasks: Falseness, Beliefs, or Attention

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Aichhorn, Markus; Perner, Josef; Weiss, Benjamin; Kronbichler, Martin; Staffen, Wolfgang; Ladurner, Gunther

2009-01-01

By combining the false belief (FB) and photo (PH) vignettes to identify theory-of-mind areas with the false sign (FS) vignettes, we re-establish the functional asymmetry between the left and right temporo-parietal junction (TPJ). The right TPJ (TPJ-R) is specially sensitive to processing belief information, whereas the left TPJ (TPJ-L) is equally…

Time-dependent anisotropic external sources in transient 3-D transport code TORT-TD

International Nuclear Information System (INIS)

Seubert, A.; Pautz, A.; Becker, M.; Dagan, R.

2009-01-01

This paper describes the implementation of a time-dependent distributed external source in TORT-TD by explicitly considering the external source in the ''fixed-source'' term of the implicitly time-discretised 3-D discrete ordinates transport equation. Anisotropy of the external source is represented by a spherical harmonics series expansion similar to the angular fluxes. The YALINA-Thermal subcritical assembly serves as a test case. The configuration with 280 fuel rods has been analysed with TORT-TD using cross sections in 18 energy groups and P1 scattering order generated by the KAPROS code system. Good agreement is achieved concerning the multiplication factor. The response of the system to an artificial time-dependent source consisting of two square-wave pulses demonstrates the time-dependent external source capability of TORT-TD. The result is physically plausible as judged from validation calculations. (orig.)

High Frequency rTMS over the Left Parietal Lobule Increases Non-Word Reading Accuracy

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Costanzo, Floriana; Menghini, Deny; Caltagirone, Carlo; Oliveri, Massimiliano; Vicari, Stefano

2012-01-01

Increasing evidence in the literature supports the usefulness of Transcranial Magnetic Stimulation (TMS) in studying reading processes. Two brain regions are primarily involved in phonological decoding: the left superior temporal gyrus (STG), which is associated with the auditory representation of spoken words, and the left inferior parietal lobe…

Open-Source Low-Cost Wireless Potentiometric Instrument for pH Determination Experiments

Science.gov (United States)

Jin, Hao; Qin, Yiheng; Pan, Si; Alam, Arif U.; Dong, Shurong; Ghosh, Raja; Deen, M. Jamal

2018-01-01

pH determination is an essential experiment in many chemistry laboratories. It requires a potentiometric instrument with extremely low input bias current to accurately measure the voltage between a pH sensing electrode and a reference electrode. In this technology report, we propose an open-source potentiometric instrument for pH determination…

Self-face recognition shares brain regions active during proprioceptive illusion in the right inferior fronto-parietal superior longitudinal fasciculus III network.

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Morita, Tomoyo; Saito, Daisuke N; Ban, Midori; Shimada, Koji; Okamoto, Yuko; Kosaka, Hirotaka; Okazawa, Hidehiko; Asada, Minoru; Naito, Eiichi

2017-04-21

Proprioception is somatic sensation that allows us to sense and recognize position, posture, and their changes in our body parts. It pertains directly to oneself and may contribute to bodily awareness. Likewise, one's face is a symbol of oneself, so that visual self-face recognition directly contributes to the awareness of self as distinct from others. Recently, we showed that right-hemispheric dominant activity in the inferior fronto-parietal cortices, which are connected by the inferior branch of the superior longitudinal fasciculus (SLF III), is associated with proprioceptive illusion (awareness), in concert with sensorimotor activity. Herein, we tested the hypothesis that visual self-face recognition shares brain regions active during proprioceptive illusion in the right inferior fronto-parietal SLF III network. We scanned brain activity using functional magnetic resonance imaging while twenty-two right-handed healthy adults performed two tasks. One was a proprioceptive illusion task, where blindfolded participants experienced a proprioceptive illusion of right hand movement. The other was a visual self-face recognition task, where the participants judged whether an observed face was their own. We examined whether the self-face recognition and the proprioceptive illusion commonly activated the inferior fronto-parietal cortices connected by the SLF III in a right-hemispheric dominant manner. Despite the difference in sensory modality and in the body parts involved in the two tasks, both tasks activated the right inferior fronto-parietal cortices, which are likely connected by the SLF III, in a right-side dominant manner. Here we discuss possible roles for right inferior fronto-parietal activity in bodily awareness and self-awareness. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Trepanation and enlarged parietal foramen on skulls from the Loyalty Islands (Melanesia).

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Vasilyev, Sergey V; Sviridov, Alexey A

2017-06-01

The goal of this study is a comprehensive examination of openings discovered on two skulls in the collection of skeletal remains from the Loyalty Islands (Melanesia). The skull No. 1524 displayed an evidence of successful trepanation, and the skull No. 7985 revealed openings that were reminiscent of a trepanation, however, we are inclined to believe that in the latter case we are dealing with a rare genetic anomaly - enlarged parietal foramen.

The 5s25p2 - (5s25p5d + 5s5p3 + 5s25p6s + 5s25p7s) transitions in Sb II and 5s25p - (5s5p2 + 5s2nl) transitions in Sb III

International Nuclear Information System (INIS)

Arcimowicz, B.; Joshi, Y.N.; Kaufman, V.

1989-01-01

The spectrum of antimony was photographed in the 575-2300 A region (1A 10 -10 m) using a hollow cathode and a triggered spark source. The analysis of the 5s 2 5p 2 - (5s 2 5p5d + 5s5p 3 + 5s 2 5p6s + 5s 2 5p7s) transitions in Sb II spectrum was revised and interpreted on the basis of multiconfiguration interaction calculations. Accurate wavelength measurements of Sb III lines lead to a revised ground-state 5s 2 5p 2 P interval value of 6574.5 cm -1 . (author). 15 refs., 9 tabs., 1 fig

Differential Medial Temporal Lobe and Parietal Cortical Contributions to Real-world Autobiographical Episodic and Autobiographical Semantic Memory.

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Brown, Thackery I; Rissman, Jesse; Chow, Tiffany E; Uncapher, Melina R; Wagner, Anthony D

2018-04-18

Autobiographical remembering can depend on two forms of memory: episodic (event) memory and autobiographical semantic memory (remembering personally relevant semantic knowledge, independent of recalling a specific experience). There is debate about the degree to which the neural signals that support episodic recollection relate to or build upon autobiographical semantic remembering. Pooling data from two fMRI studies of memory for real-world personal events, we investigated whether medial temporal lobe (MTL) and parietal subregions contribute to autobiographical episodic and semantic remembering. During scanning, participants made memory judgments about photograph sequences depicting past events from their life or from others' lives, and indicated whether memory was based on episodic or semantic knowledge. Results revealed several distinct functional patterns: activity in most MTL subregions was selectively associated with autobiographical episodic memory; the hippocampal tail, superior parietal lobule, and intraparietal sulcus were similarly engaged when memory was based on retrieval of an autobiographical episode or autobiographical semantic knowledge; and angular gyrus demonstrated a graded pattern, with activity declining from autobiographical recollection to autobiographical semantic remembering to correct rejections of novel events. Collectively, our data offer insights into MTL and parietal cortex functional organization, and elucidate circuitry that supports different forms of real-world autobiographical memory.

The parietal memory network activates similarly for true and associative false recognition elicited via the DRM procedure.

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McDermott, Kathleen B; Gilmore, Adrian W; Nelson, Steven M; Watson, Jason M; Ojemann, Jeffrey G

2017-02-01

Neuroimaging investigations of human memory encoding and retrieval have revealed that multiple regions of parietal cortex contribute to memory. Recently, a sparse network of regions within parietal cortex has been identified using resting state functional connectivity (MRI techniques). The regions within this network exhibit consistent task-related responses during memory formation and retrieval, leading to its being called the parietal memory network (PMN). Among its signature patterns are: deactivation during initial experience with an item (e.g., encoding); activation during subsequent repetitions (e.g., at retrieval); greater activation for successfully retrieved familiar words than novel words (e.g., hits relative to correctly-rejected lures). The question of interest here is whether novel words that are subjectively experienced as having been recently studied would elicit PMN activation similar to that of hits. That is, we compared old items correctly recognized to two types of novel items on a recognition test: those correctly identified as new and those incorrectly labeled as old due to their strong associative relation to the studied words (in the DRM false memory protocol). Subjective oldness plays a strong role in driving activation, as hits and false alarms activated similarly (and greater than correctly-rejected lures). Copyright © 2016 Elsevier Ltd. All rights reserved.

Hvad spillede de egentlig på P3 i januar 1963? 50 år med P3

DEFF Research Database (Denmark)

Smith-Sivertsen, Henrik

2015-01-01

ungdomsmusik, før P3 kom til, bl.a. med Jørn Hjorting som vært, og Jørgen de Mylius var langtfra den eneste af de nye P3-værter, der slog et ekstra slag for den ny musik. Smith-Sivertsen viser, at Pedro Biker og Hans Jørgen Skov bidrog i lige så høj grad til udbredelsen af fx The Beatles....

Repair of large frontal temporal parietal skull defect with digitally reconstructed titanium mesh: a report of 20 cases

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Gang-ge CHENG

2013-09-01

Full Text Available Objective　To explore the clinical effect and surgical technique of the repair of large defect involving frontal, temporal, and parietal regions using digitally reconstructed titanium mesh. Methods　Twenty patients with large frontal, temporal, and parietal skull defect hospitalized in Air Force General Hospital from November 2006 to May 2012 were involved in this study. In these 20 patients, there were 13 males and 7 females, aged 18-58 years (mean 39 years, and the defect size measured from 7.0cm×9.0cm to 11.5cm×14.0cm (mean 8.5cm×12.0cm. Spiral CT head scan and digital three-dimensional reconstruction of skull were performed in all the patients. The shape and geometric size of skull defect was traced based on the symmetry principle, and then the data were transferred into digital precision lathe to reconstruct a titanium mesh slightly larger (1.0-1.5cm than the skull defect, and the finally the prosthesis was perfected after pruning the border. Cranioplasty was performed 6-12 months after craniotomy using the digitally reconstructed titanium mesh. Results　The digitally reconstructed titanium mesh was used in 20 patients with large frontal, temporal, parietal skull defect. The surgical technique was relatively simple, and the surgical duration was shorter than before. The titanium mesh fit to the defect of skull accurately with satisfactory molding effect, good appearance and symmetrical in shape. No related complication was found in all the patients. Conclusion　Repair of large frontal, temporal, parietal skull defect with digitally reconstructed titanium mesh is more advantageous than traditional manual reconstruction, and it can improve the life quality of patients.

ERP correlates of source memory: unitized source information increases familiarity-based retrieval.

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Diana, Rachel A; Van den Boom, Wijnand; Yonelinas, Andrew P; Ranganath, Charan

2011-01-07

Source memory tests typically require subjects to make decisions about the context in which an item was encoded and are thought to depend on recollection of details from the study episode. Although it is generally believed that familiarity does not contribute to source memory, recent behavioral studies have suggested that familiarity may also support source recognition when item and source information are integrated, or "unitized," during study (Diana, Yonelinas, and Ranganath, 2008). However, an alternative explanation of these behavioral findings is that unitization affects the manner in which recollection contributes to performance, rather than increasing familiarity-based source memory. To discriminate between these possibilities, we conducted an event-related potential (ERP) study testing the hypothesis that unitization increases the contribution of familiarity to source recognition. Participants studied associations between words and background colors using tasks that either encouraged or discouraged unitization. ERPs were recorded during a source memory test for background color. The results revealed two distinct neural correlates of source recognition: a frontally distributed positivity that was associated with familiarity-based source memory in the high-unitization condition only and a parietally distributed positivity that was associated with recollection-based source memory in both the high- and low-unitization conditions. The ERP and behavioral findings provide converging evidence for the idea that familiarity can contribute to source recognition, particularly when source information is encoded as an item detail. Copyright © 2010 Elsevier B.V. All rights reserved.

The Role of the Parietal Lobe in Visual Extinction Studied with Transcranial Magnetic Stimulation

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Battelli, Lorella; Alvarez, George A.; Carlson, Thomas; Pascual-Leone, Alvaro

2009-01-01

Interhemispheric competition between homologous areas in the human brain is believed to be involved in a wide variety of human behaviors from motor activity to visual perception and particularly attention. For example, patients with lesions in the posterior parietal cortex are unable to selectively track objects in the contralesional side of…

Excitation light source dependence of emission in Sn2+-Ce3+ codoped ZnO-P2O5 glasses

OpenAIRE

Masai, Hirokazu; Hino, Yusuke; Yanagida, Takayuki; Fujimoto, Yutaka; Fukuda, Kentaro; Yoko, Toshinobu

2013-01-01

Correlation between excitation light source and the emission property of Sn^{2+}-Ce^{3+} co-doped zinc phosphate glasses is examined. Although photoluminescence (PL) peaks of both Sn^{2+}and Ce^{3+} shifted with increasing amount of Ce^{3+}, there was little energy resonance between Sn^{2+} and Ce^{3+} emission centers. On the other hand, radioluminescence (RL) spectra excited by X-ray was independent of the Ce concentration, indicating that emission was mainly observed from Sn^{2+} emission ...

MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject.

Science.gov (United States)

Ioannides, Andreas A; Liu, Lichan; Poghosyan, Vahe; Saridis, George A; Gjedde, Albert; Ptito, Maurice; Kupers, Ron

2013-01-01

Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG) data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1) and motor (M1) cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45-70 Hz activity at latencies of 20-50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA) 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong, and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI) revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occurred in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex.

The sixth sense in mammalian forerunners: Variability of the parietal foramen and the evolution of the pineal eye in South African Permo-Triassic eutheriodont therapsids

Directory of Open Access Journals (Sweden)

Julien Benoit

2016-12-01

Full Text Available In some extant ectotherms, the third eye (or pineal eye is a photosensitive organ located in the parietal foramen on the midline of the skull roof. The pineal eye sends information regarding exposure to sunlight to the pineal complex, a region of the brain devoted to the regulation of body temperature, reproductive synchrony, and biological rhythms. The parietal foramen is absent in mammals but present in most of the closest extinct relatives of mammals, the Therapsida. A broad ranging survey of the occurrence and size of the parietal foramen in different South African therapsid taxa demonstrates that through time the parietal foramen tends, in a convergent manner, to become smaller and is absent more frequently in eutherocephalians (Akidnognathiidae, Whaitsiidae, and Baurioidea and non-mammaliaform eucynodonts. Among the latter, the Probainognathia, the lineage leading to mammaliaforms, are the only one to achieve the complete loss of the parietal foramen. These results suggest a gradual and convergent loss of the photoreceptive function of the pineal organ and degeneration of the third eye. Given the role of the pineal organ to achieve fine-tuned thermoregulation in ectotherms (i.e., “cold-blooded” vertebrates, the gradual loss of the parietal foramen through time in the Karoo stratigraphic succession may be correlated with the transition from a mesothermic metabolism to a high metabolic rate (endothermy in mammalian ancestry. The appearance in the eye of melanopsin-containing retinal ganglion cells replacing the photoreceptive role of the pineal eye could also have accompanied its loss.

Alignment of Ar{sup +} [{sup 3}P]4p{sup 2}P{sup 0}{sub 3/2} satellite state from the polarization analysis of fluorescent radiation after photoionization

Energy Technology Data Exchange (ETDEWEB)

Yenen, O.; McLaughlin, K.W.; Jaecks, D.H. [Univ. of Nebraska, Lincoln, NE (United States)] [and others

1997-04-01

The measurement of the polarization of radiation from satellite states of Ar{sup +} formed after the photoionization of Ar provides detailed information about the nature of doubly excited states, magnetic sublevel cross sections and partial wave ratios of the photo-ejected electrons. Since the formation of these satellite states is a weak process, it is necessary to use a high flux beam of incoming photons. In addition, in order to resolve the many narrow doubly excited Ar resonances, the incoming photons must have a high resolution. The characteristics of the beam line 9.0.1 of the Advanced Light Source fulfill these requirements. The authors determined the polarization of 4765 {Angstrom} fluorescence from the Ar{sup +} [{sup 3}P] 4p {sup 2}P{sub 3/2}{sup 0} satellite state formed after photoionization of Ar by photons from the 9.0.1 beam line of ALS in the 35.620-38.261 eV energy range using a resolution of approximately 12,700. This is accomplished by measuring the intensities of the fluorescent light polarized parallel (I{parallel}) and perpendicular (I{perpendicular}) to the polarization axis of the incident synchrotron radiation using a Sterling Optics 105MB polarizing filter. The optical system placed at 90{degrees} with respect to the polarization axis of the incident light had a narrow band interference filter ({delta}{lambda}=0.3 nm) to isolate the fluorescent radiation.

The 4p3(2P) ns, nd configurations of Se I

International Nuclear Information System (INIS)

Mazzoni, M.

1989-01-01

The photoabsorption spectrum of Se I has been photographed in the 1100-900 A wavelength region, using a flash-pyrolisys system: About twenty lines were observed, most of them for the first time. With the support of Hartree-Fock calculations they have been identified and assigned to the 4p 4 →4p 3 ns 3 P(n=7-14) and 4p 4 →4p 3 nd 3 D (n=5-17) series, both converging on the limit 4p 3 ( 2 P 3/2 ). (orig.)

Texture and acceptability of goat meat frankfurters processed with 3 different sources of fat.

Science.gov (United States)

Bratcher, C L; Dawkins, N L; Solaiman, S; Kerth, C R; Bartlett, J R

2011-05-01

The objective of this research was to evaluate the texture and consumer acceptability of goat meat frankfurter formulations with no added fat (NAF), beef fat (BF), or canola oil (CO). Consumer sensory evaluation, fat, and moisture and texture profile analyses were performed on goat meat frankfurters produced with the fat sources BF, CO, and NAF. For sensory evaluations, NAF was less tender (P = 0.007; 4.90 vs. 4.11 and 4.35 for BF and CO, respectively) and the flavor was liked less (P = 0.004; 4.59 vs. 3.83 and 4.30 for BF and CO, respectively); BF was scored as the juiciest (P = 0.003; 3.86 vs. 4.49 and 4.58 for CO and NAF, respectively); and CO had the least amount of flavor (P = 0.029; 3.65 vs. 3.12 and 3.10 for BF and NAF, respectively). Moisture was least (P goat meat products received acceptable sensory scores; therefore, continued research and development will greatly expand the knowledge of goat meat and increase the acceptance of value-added products.

Normal variation of focal T2 Hyperintensities in anterior parietal periventricular white matter: Another 'Terminal Zones of Myelination'

International Nuclear Information System (INIS)

Park, Jong Oag; Woo, Je Ho; Ki, Tae Sung; Lee, Jong Hwa; Chung, Jin Woo; Lee, Don Young

1994-01-01

It has been known that there are several areas of T2 hyperintensity in normal white matter of brain, such as terminal zones of myelination, ependymitis granularis, ones of posterior internal capsule, and perivascular space. The aim of our study is to demonstrate another region of T2 hyperintensities in normal pediatric age group. We have studied brain MR for 10 normal volunteers and 35 patients without having intracranial lesions in pediatric age group(3-19 years). In 5 among 45 cases, focal T2 hyperintensities were seen in the parietal periventricular white matter beneath the postcentral gyri. They were noted as poorly defined, 5-10 mm sized areas of increased signal intensities on T2-weighted axial images. They were also characterized by bilateral, posteromedially oriented, short band-like or oval areas. Interestingly, they were directly continuous with the T2 hyperintensity of posterior internal capsule. In spite of the relatively highly frequency in the pediatric population as in our study, this finding has not been reported in the asymptomatic adults. The results show that the bilateral anterior parietal hyperintense areas may be another terminal zones of delayed myelination affecting the parietopontine tract. They should be differentiated from pathologic T2 hyperintensities by their characteristic findings

TSUNAMI INFORMATION SOURCES PART 3

Directory of Open Access Journals (Sweden)

Robert L. Wiegel

2009-01-01

Full Text Available This is Part 3 of Tsunami Information Sources published by Robert L. Wiegel, as Technical Report UCB/HEL 2006-3 of the Hydraulic Engineering Laboratory of the Department of Civil & Environmental Engineering of the University of California at Berkeley. Part 3 is published in "SCIENCE OF TSUNAMI HAZARDS" -with the author's permission -so that it can receive wider distribution and use by the Tsunami Scientific Community.

Proliferating cells in HIV and pamidronate-associated collapsing focal segmental glomerulosclerosis are parietal epithelial cells.

NARCIS (Netherlands)

Dijkman, H.B.P.M.; Weening, J.J.; Smeets, B.; Verrijp, K.; Kuppevelt, A.H.M.S.M. van; Assmann, K.K.; Steenbergen, E.; Wetzels, J.F.M.

2006-01-01

Collapsing focal segmental glomerulosclerosis (cFSGS) is characterized by hyperplasia of glomerular epithelial cells. In a mouse model of FSGS and in a patient with recurrent idiopathic FSGS, we identified the proliferating cells as parietal epithelial cells (PECs). In the present study, we have

Proliferating cells in HIV and pamidronate-associated collapsing focal segmental glomerulosclerosis are parietal epithelial cells

NARCIS (Netherlands)

Dijkman, H. B. P. M.; Weening, J. J.; Smeets, B.; Verrijp, K. C. N.; van Kuppevelt, T. H.; Assmann, K. K. J. M.; Steenbergen, E. J.; Wetzels, J. F. M.

2006-01-01

Collapsing focal segmental glomerulosclerosis (cFSGS) is characterized by hyperplasia of glomerular epithelial cells. In a mouse model of FSGS and in a patient with recurrent idiopathic FSGS, we identified the proliferating cells as parietal epithelial cells (PECs). In the present study, we have

Hybrid diffusion-P3 equation in N-layered turbid media: steady-state domain.

Science.gov (United States)

Shi, Zhenzhi; Zhao, Huijuan; Xu, Kexin

2011-10-01

This paper discusses light propagation in N-layered turbid media. The hybrid diffusion-P3 equation is solved for an N-layered finite or infinite turbid medium in the steady-state domain for one point source using the extrapolated boundary condition. The Fourier transform formalism is applied to derive the analytical solutions of the fluence rate in Fourier space. Two inverse Fourier transform methods are developed to calculate the fluence rate in real space. In addition, the solutions of the hybrid diffusion-P3 equation are compared to the solutions of the diffusion equation and the Monte Carlo simulation. For the case of small absorption coefficients, the solutions of the N-layered diffusion equation and hybrid diffusion-P3 equation are almost equivalent and are in agreement with the Monte Carlo simulation. For the case of large absorption coefficients, the model of the hybrid diffusion-P3 equation is more precise than that of the diffusion equation. In conclusion, the model of the hybrid diffusion-P3 equation can replace the diffusion equation for modeling light propagation in the N-layered turbid media for a wide range of absorption coefficients.

Single-cell analysis of peptide expression and electrophysiology of right parietal neurons involved in male copulation behavior of a simultaneous hermaphrodite.

Science.gov (United States)

El Filali, Z; de Boer, P A C M; Pieneman, A W; de Lange, R P J; Jansen, R F; Ter Maat, A; van der Schors, R C; Li, K W; van Straalen, N M; Koene, J M

2015-12-01

Male copulation is a complex behavior that requires coordinated communication between the nervous system and the peripheral reproductive organs involved in mating. In hermaphroditic animals, such as the freshwater snail Lymnaea stagnalis, this complexity increases since the animal can behave both as male and female. The performance of the sexual role as a male is coordinated via a neuronal communication regulated by many peptidergic neurons, clustered in the cerebral and pedal ganglia and dispersed in the pleural and parietal ganglia. By combining single-cell matrix-assisted laser mass spectrometry with retrograde staining and electrophysiology, we analyzed neuropeptide expression of single neurons of the right parietal ganglion and their axonal projections into the penial nerve. Based on the neuropeptide profile of these neurons, we were able to reconstruct a chemical map of the right parietal ganglion revealing a striking correlation with the earlier electrophysiological and neuroanatomical studies. Neurons can be divided into two main groups: (i) neurons that express heptapeptides and (ii) neurons that do not. The neuronal projection of the different neurons into the penial nerve reveals a pattern where (spontaneous) activity is related to branching pattern. This heterogeneity in both neurochemical anatomy and branching pattern of the parietal neurons reflects the complexity of the peptidergic neurotransmission involved in the regulation of male mating behavior in this simultaneous hermaphrodite.

The Effects of Maternal Hyperthyroidism on Histologic Changes in Parietal Lobe in Rat Embryos

Directory of Open Access Journals (Sweden)

Fatemeh Mirsafi

2017-05-01

Full Text Available Background Maternal hyperthyroidism causes developmental defects on the nervous system of fetuses. Objectives The present study was designed to study the effects of maternal hyperthyroidism on the development of the parietal lobe in the brain of rat embryos. Methods In this experimental study, thirty Sprague-Dawley rats were randomly divided into three groups. The control group received no injections, the sham group received intraperitoneal injections of distilled water solution containing salt and polysorbate (solvent of levothyroxine, and the experimental group received once-daily, intraperitoneal injections of 0.5 mg/kg levothyroxine for a 10-day period to become hyperthyroid rats. The hyperthyroid rats were then mated, and all pregnant rats were killed on the 20th day of gestation. Fetuses were removed, fixed, and processed for histological procedures. The fetuses were sagitally sectioned at 5 µ thickness and stained with hematoxylin-eosin (H and E technique. The sections were examined using a light microscope and Motic software. Results The results showed no significant difference in the studied variables between the sham and control groups. A significantly increase in body weight and a significant decrease in crown-rump length of embryos was observed in the experimental group when compared to the control group. The mean total thickness of the parietal cortex, ventricular layer, and intermediate layer of embryos showed a significant decrease in the experimental group compared to the control and sham groups. The mean number of cells also showed a significant decrease in the intermediate and ventricular layers in the experimental group compared to the control and sham groups. Conclusions This study showed that maternal hyperthyroidism leads to a reduction in development of the parietal cortex in embryos. Maternal hyperthyroidism can disturb the growth and development of embryos.

Analysis of the spectrum six times ionized zinc (Zn VII): the 3d6-3d54p transition array

International Nuclear Information System (INIS)

Hof, G.H. van het; Joshi, Y.N.; Raassen, A.J.J.; Ryabtsev, A.N.

1993-01-01

The spectrum of zinc was photographed in the 100-300 A region on a 10.7 m grazing incidence spectrograph using a triggered spark light source. 335 lines were classified in the Zn VII 3d 6 -3d 5 4p transition array, resulting in the establishment of 30 of the 34 levels of the 3d 6 configuration and 103 of the 214 levels of the 3d 5 4p. The ground configuration 3d 6 was described by a generalized least-squares fit (GLSF) involving orthogonal operators to a set of 3d N configurations. This yielded a mean error of 3 cm -1 for its level values. The excited configruation was described by the conventional Slater Condon parameter set, giving a mean error of 105 cm -1 . (orig.)

Studies of temporoparietal hypoperfusion in patients with Alzheimer's disease

International Nuclear Information System (INIS)

Ang Qiuqing; Jiang Kaida; Lin Xiangtong; Jin Shaojin; Zhang Mingyuan

2001-01-01

Objective: To understand the differences of brain perfusion changes in patients with Alzheimer's disease (AD) and healthy elders and to find out which is pathological and which is biological. To figure out the significance of low perfusion in temporal and parietal lobes to AD. Methods: Sixty AD patients were assigned to 3 age groups: 60-65 years old (adl), 66-70 (ad2) and over 70 (ad3). Seventy-three healthy elders were also assigned to 3 age groups as nor1, nor2 and nor3. Sixty AD patients and all control subjects were examined with SPECT. Results: Significant differences (P < 0.01) were found in perfusion at right parietal lobes between nor2 and nor1. Perfusions at bilateral temporal (P < 0.05), parietal (P < 0.01) and frontal (P < 0.01) lobes were significantly lower in AD patients than in controls. There were no significant difference in SPECT measures at all regions of interest among 3 AD age groups. In 60-65 group, perfusions at left temporal (P < 0.05), bilateral parietal (P < 0.01), left frontal (P < 0.01) and right frontal (P < 0.05) lobes were significantly lower in AD patients than in controls; in over 70 group, perfusions at bilateral parietal (P < 0.01) and frontal (P < 0.01) lobes were significantly lower in AD patients than in controls. All of the AD patients were categorized into 3 subgroups, in hierarchical cluster analysis through agglomeration, with bilateral parietal perfusion index as variate: sub-group I (subad1): 31 cases, MMSE scored from 20-24; sub-group II (subad 2): 22 cases, MMSE 13-19; sub-group III (subad3): 7 cases, MMSE 5-11. Conclusions: The extent and magnitude of cerebral blood hypoperfusion in AD patients were much more severe than in normal age-related changes in healthy controls. Bilateral parietal perfusion could be adopted as an effective categorical measure for AD patients at various severity

Duoplasmatron source modifications for 3He+ operation

Science.gov (United States)

Schmidt, C. W.; Popovic, M.

1998-02-01

A duoplasmatron ion source is used to produce 25 mA of 3He+ with a pulse width of ˜80 ms at 360 Hz for acceleration to 10.5 MeV. At this energy, 3He striking water or carbon targets can produce short lived isotopes of 11C, 13N, 15O, and 18F for medical positron emission tomography (PET). A duoplasmatron ion source was chosen originally since it is capable of a sufficient singly charged helium beam with an acceptable gas consumption. Stable long-term operation of the source required a change in the filament material to molybdenum, and a careful understanding of the oxide filament conditioning, operation and geometry. Other improvements, particularly in the electronics, were helpful to increasing the reliability. The source has operated for many months at ˜2.5% duty factor without significant problems and with good stability. We report here the effort that was done to make this source understandable and reliable.

Duoplasmatron source modifications for 3He+ Operation

International Nuclear Information System (INIS)

Schmidt, C.W.; Popovic, M.

1997-11-01

A duoplasmatron ion source is used to produce 25 mA of 3 He+ with a pulse width of ∼80 ms at 360 Hz for acceleration to 10.5 MeV. At this energy, 3 He striking water or carbon targets can produce short lived isotopes of 11 C, 13 N, 15 O and 18 F for medical positron emission tomography (PET). A duoplasmatron ion source was chosen originally since it is capable of a sufficient singly-charged helium beam with an acceptable gas consumption. Stable long-term operation of the source required a change in the filament material to molybdenum, and a careful understanding of the oxide filament conditioning, operation and geometry. Other improvements, particularly in the electronics, were helpful to increasing the reliability. The source has operated for many months at ∼2.5% duty factor without significant problems and with good stability. We report here the effort that was done to make this source understandable and reliable

Duoplasmatron source modifications for 3He+ operation

International Nuclear Information System (INIS)

Schmidt, C.W.; Popovic, M.

1998-01-01

A duoplasmatron ion source is used to produce 25 mA of 3 He + with a pulse width of ∼80ms at 360 Hz for acceleration to 10.5 MeV. At this energy, 3 He striking water or carbon targets can produce short lived isotopes of 11 C, 13 N, 15 O, and 18 F for medical positron emission tomography (PET). A duoplasmatron ion source was chosen originally since it is capable of a sufficient singly charged helium beam with an acceptable gas consumption. Stable long-term operation of the source required a change in the filament material to molybdenum, and a careful understanding of the oxide filament conditioning, operation and geometry. Other improvements, particularly in the electronics, were helpful to increasing the reliability. The source has operated for many months at ∼2.5% duty factor without significant problems and with good stability. We report here the effort that was done to make this source understandable and reliable

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

OpenAIRE

Myskiw, Jociane C.; Izquierdo, Iván

2012-01-01

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

The Effects of Maternal Hyperthyroidism on Histologic Changes in Parietal Lobe in Rat Embryos

OpenAIRE

Fatemeh Mirsafi; Gholamreza Kaka; Mahnaz Azarnia

2017-01-01

Background Maternal hyperthyroidism causes developmental defects on the nervous system of fetuses. Objectives The present study was designed to study the effects of maternal hyperthyroidism on the development of the parietal lobe in the brain of rat embryos. Methods In this experimental study, thirty Sprague-Dawley rats were randomly divided into three groups. The control group rec...

Laser source with high pulse energy at 3-5 μm and 8-12 μm based on nonlinear conversion in ZnGeP2

Science.gov (United States)

Lippert, Espen; Fonnum, Helge; Haakestad, Magnus W.

2014-10-01

We present a high energy infrared laser source where a Tm:fiber laser is used to pump a high-energy 2-μm cryogenically cooled Ho:YLF laser. We have achieved 550 mJ of output energy at 2.05 μm, and through non-linear conversion in ZnGeP2 generated 200 mJ in the 3-5-μm range. Using a numerical simulation tool we have also investigated a setup which should generate more than 70 mJ in the 8-12-μm range. The conversion stage uses a master-oscillator-power-amplifier architecture to enable high conversion efficiency and good beam quality.

Abnormal frontoparietal synaptic gain mediating the P300 in patients with psychotic disorder and their unaffected relatives.

Science.gov (United States)

Díez, Álvaro; Ranlund, Siri; Pinotsis, Dimitris; Calafato, Stella; Shaikh, Madiha; Hall, Mei-Hua; Walshe, Muriel; Nevado, Ángel; Friston, Karl J; Adams, Rick A; Bramon, Elvira

2017-06-01

The "dysconnection hypothesis" of psychosis suggests that a disruption of functional integration underlies cognitive deficits and clinical symptoms. Impairments in the P300 potential are well documented in psychosis. Intrinsic (self-)connectivity in a frontoparietal cortical hierarchy during a P300 experiment was investigated. Dynamic Causal Modeling was used to estimate how evoked activity results from the dynamics of coupled neural populations and how neural coupling changes with the experimental factors. Twenty-four patients with psychotic disorder, twenty-four unaffected relatives, and twenty-five controls underwent EEG recordings during an auditory oddball paradigm. Sixteen frontoparietal network models (including primary auditory, superior parietal, and superior frontal sources) were analyzed and an optimal model of neural coupling, explaining diagnosis and genetic risk effects, as well as their interactions with task condition were identified. The winning model included changes in connectivity at all three hierarchical levels. Patients showed decreased self-inhibition-that is, increased cortical excitability-in left superior frontal gyrus across task conditions, compared with unaffected participants. Relatives had similar increases in excitability in left superior frontal and right superior parietal sources, and a reversal of the normal synaptic gain changes in response to targets relative to standard tones. It was confirmed that both subjects with psychotic disorder and their relatives show a context-independent loss of synaptic gain control at the highest hierarchy levels. The relatives also showed abnormal gain modulation responses to task-relevant stimuli. These may be caused by NMDA-receptor and/or GABAergic pathologies that change the excitability of superficial pyramidal cells and may be a potential biological marker for psychosis. Hum Brain Mapp 38:3262-3276, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Electrophysiological evidence for cognitive control during conflict processing in visual spatial attention.

Science.gov (United States)

Kehrer, Stefanie; Kraft, Antje; Irlbacher, Kerstin; Koch, Stefan P; Hagendorf, Herbert; Kathmann, Norbert; Brandt, Stephan A

2009-11-01

Event-related potentials were measured to investigate the role of visual spatial attention mechanisms in conflict processing. We suggested that a more difficult target selection leads to stronger attentional top-down control, thereby reducing the effects of arising conflicts. This hypothesis was tested by varying the selection difficulty in a location negative priming (NP) paradigm. The difficult task resulted in prolonged responses as compared to the easy task. A behavioral NP effect was only evident in the easy task. Psychophysiologically the easy task was associated with reduced parietal N1, enhanced frontocentral N2 and N2pc components and a prolonged P3 latency for the conflict as compared to the control condition. The N2pc effect was also obvious in the difficult task. Additionally frontocentral N2 amplitudes increased and latencies of N2pc and P3 were delayed compared to the easy task. The differences at frontocentral and parietal electrodes are consistent with previous studies ascribing activity in the prefrontal and parietal cortex as the source of top-down attentional control. Thus, we propose that stronger cognitive control is involved in the difficult task, resulting in a reduced behavioral NP conflict.

Symptomatic Parietal Intradiploic Encephalocele—A Case Report and Literature Review

Science.gov (United States)

Shi, Chen; Flores, Bruno; Fisher, Stephen; Barnett, Samuel L

2017-01-01

Encephalocele is a rare condition that consists of herniation of cerebral matter through openings of dura and skull. A majority of encephaloceles are congenital and manifest in childhood. We present a case of a 45-year-old man presenting with contralateral hemiparesis and found to have an extremely rare phenomenon of a symptomatic posttraumatic parietal intradiploic encephalocele (IE) manifesting 36 years following pediatric traumatic head injury. Computed tomography and magnetic resonance imaging confirmed herniation of brain tissue into the intradiploic space. Surgical treatment with reduction of the encephalocele achieved near resolution of preoperative hemiparesis on follow-up. The pathogenesis and a literature review of IE are discussed. PMID:28316901

Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory.

Science.gov (United States)

Kawasaki, Masahiro; Kitajo, Keiichi; Yamaguchi, Yoko

2014-01-01

In humans, theta phase (4-8 Hz) synchronization observed on electroencephalography (EEG) plays an important role in the manipulation of mental representations during working memory (WM) tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from subjects who were performing auditory-verbal and visual WM tasks; we compared the theta synchronizations when subjects performed either auditory-verbal or visual manipulations in separate WM tasks, or performed both two manipulations in the same WM task. The auditory-verbal WM task required subjects to calculate numbers presented by an auditory-verbal stimulus, whereas the visual WM task required subjects to move a spatial location in a mental representation in response to a visual stimulus. The dual WM task required subjects to manipulate auditory-verbal, visual, or both auditory-verbal and visual representations while maintaining auditory-verbal and visual representations. Our time-frequency EEG analyses revealed significant fronto-temporal theta phase synchronization during auditory-verbal manipulation in both auditory-verbal and auditory-verbal/visual WM tasks, but not during visual manipulation tasks. Similarly, we observed significant fronto-parietal theta phase synchronization during visual manipulation tasks, but not during auditory-verbal manipulation tasks. Moreover, we observed significant synchronization in both the fronto-temporal and fronto-parietal theta signals during simultaneous auditory-verbal/visual manipulations. These findings suggest that theta synchronization seems to flexibly connect the brain areas that manipulate WM.

Inferior parietal and right frontal contributions to trial-by-trial adaptations of attention to memory.

Science.gov (United States)

Kizilirmak, Jasmin M; Rösler, Frank; Bien, Siegfried; Khader, Patrick H

2015-07-21

The attention to memory theory (AtoM) proposes that the same brain regions might be involved in selective processing of perceived stimuli (selective attention) and memory representations (selective retrieval). Although this idea is compelling, given consistently found neural overlap between perceiving and remembering stimuli, recent comparisons brought evidence for overlap as well as considerable differences. Here, we present a paradigm that enables the investigation of the AtoM hypothesis from a novel perspective to gain further insight into the neural resources involved in AtoM. Selective attention in perception is often investigated as a control process that shows lingering effects on immediately following trials. Here, we employed a paradigm capable of modulating selective retrieval in a similarly dynamic manner as in such selective-attention paradigms by inducing trial-to-trial shifts between relevant and irrelevant memory representations as well as changes of the width of the internal focus on memory. We found evidence for an involvement of bilateral inferior parietal lobe and right inferior frontal gyrus in reorienting the attentional focus on previously accessed memory representations. Moreover, we could dissociate the right inferior from the parietal activation in separate contrasts, suggesting that the right inferior frontal gyrus plays a role in facilitating attentional reorienting to memory representations when competing representations have been activated in the preceding trial, potentially by resolving this competition. Our results support the AtoM theory, i.e. that ventral frontal and parietal regions are involved in automatic attentional reorienting in memory, and highlight the importance of further investigations of the overlap and differences between regions involved in internal (memory) and external (perceptual) attentional selection. Copyright © 2015 Elsevier B.V. All rights reserved.

Fronto-parietal and fronto-temporal theta phase synchronization for visual and auditory-verbal working memory

Directory of Open Access Journals (Sweden)

Masahiro eKawasaki

2014-03-01

Full Text Available In humans, theta phase (4–8 Hz synchronization observed on electroencephalography (EEG plays an important role in the manipulation of mental representations during working memory (WM tasks; fronto-temporal synchronization is involved in auditory-verbal WM tasks and fronto-parietal synchronization is involved in visual WM tasks. However, whether or not theta phase synchronization is able to select the to-be-manipulated modalities is uncertain. To address the issue, we recorded EEG data from subjects who were performing auditory-verbal and visual WM tasks; we compared the theta synchronizations when subjects performed either auditory-verbal or visual manipulations in separate WM tasks, or performed both two manipulations in the same WM task. The auditory-verbal WM task required subjects to calculate numbers presented by an auditory-verbal stimulus, whereas the visual WM task required subjects to move a spatial location in a mental representation in response to a visual stimulus. The dual WM task required subjects to manipulate auditory-verbal, visual, or both auditory-verbal and visual representations while maintaining auditory-verbal and visual representations. Our time-frequency EEG analyses revealed significant fronto-temporal theta phase synchronization during auditory-verbal manipulation in both auditory-verbal and auditory-verbal/visual WM tasks, but not during visual manipulation tasks. Similarly, we observed significant fronto-parietal theta phase synchronization during visual manipulation tasks, but not during auditory-verbal manipulation tasks. Moreover, we observed significant synchronization in both the fronto-temporal and fronto-parietal theta signals during simultaneous auditory-verbal/visual manipulations. These findings suggest that theta synchronization seems to flexibly connect the brain areas that manipulate WM.

Deep 3 GHz number counts from a P(D) fluctuation analysis

Science.gov (United States)

Vernstrom, T.; Scott, Douglas; Wall, J. V.; Condon, J. J.; Cotton, W. D.; Fomalont, E. B.; Kellermann, K. I.; Miller, N.; Perley, R. A.

2014-05-01

Radio source counts constrain galaxy populations and evolution, as well as the global star formation history. However, there is considerable disagreement among the published 1.4-GHz source counts below 100 μJy. Here, we present a statistical method for estimating the μJy and even sub-μJy source count using new deep wide-band 3-GHz data in the Lockman Hole from the Karl G. Jansky Very Large Array. We analysed the confusion amplitude distribution P(D), which provides a fresh approach in the form of a more robust model, with a comprehensive error analysis. We tested this method on a large-scale simulation, incorporating clustering and finite source sizes. We discuss in detail our statistical methods for fitting using Markov chain Monte Carlo, handling correlations, and systematic errors from the use of wide-band radio interferometric data. We demonstrated that the source count can be constrained down to 50 nJy, a factor of 20 below the rms confusion. We found the differential source count near 10 μJy to have a slope of -1.7, decreasing to about -1.4 at fainter flux densities. At 3 GHz, the rms confusion in an 8-arcsec full width at half-maximum beam is ˜ 1.2 μJy beam-1, and a radio background temperature ˜14 mK. Our counts are broadly consistent with published evolutionary models. With these results, we were also able to constrain the peak of the Euclidean normalized differential source count of any possible new radio populations that would contribute to the cosmic radio background down to 50 nJy.

Superconductivity in Ti3P-type compounds

International Nuclear Information System (INIS)

Wills, J.O.; Hein, R.A.; Waterstrat, R.M.

1978-01-01

A study of 12 intermetallic A 3 B compounds which crsytallize in the tetragonal Ti 3 P-type structure has revealed five new superconductors with transition temperatures below 1 K: Zr 3 Si, Zr 3 Ge, Zr 3 P, V 3 P, and Nb 3 Ge (extrapolated from the alloy series Nb-Ge-As). In addition, two compounds, Zr 3 Sb and Ta 3 Ge, having the Ni 3 P structure type are found to be superconducting below 1 K. Within the Ti 3 P-type compounds, those with the lighter ''B'' elements in a given column of the Periodic Table have the higher transition temperatures. Critical-magnetic-field and electrical-resistivity data are reported for the superconducting Ti 2 P-type compound Nb 3 P, which permit one to estimate the Ginzburg-Landau kappa parameter and the electronic-specific-heat coefficient γ. The kappa value of 8.4 indicates that this material is type II, and the γ value of 1.3 mJ/mole K 2 for Nb 3 P is probably related to its low transition temperature relative to many A15 compounds

Performance evaluation of 3D-DDTC detectors on p-type substrates

International Nuclear Information System (INIS)

Dalla Betta, Gian-Franco; Boscardin, Maurizio; Bosisio, Luciano; Koehler, Michael; Parzefall, Ulrich; Ronchin, Sabina; Wiik, Liv; Zoboli, Andrea; Zorzi, Nicola

2010-01-01

In this work, we report on the noise and signal properties of n-on-p, 3D Double-Side Double Type Column (3D-DDTC) detectors fabricated at FBK-irst (Trento, Italy). Compared to full 3D detectors, devices made with this approach allow for a simpler fabrication process, but the efficiency and speed of the charge collection process critically depend on the column overlap and should be carefully evaluated. Measurements were performed on detectors in the microstrip configuration coupled to the ATLAS ABCD3T binary read-out. Spatially resolved signal efficiency tests made with a pulsed infrared laser setup and charge collection efficiency tests made with a β source setup are here reported.

Performance evaluation of 3D-DDTC detectors on p-type substrates

Energy Technology Data Exchange (ETDEWEB)

Dalla Betta, Gian-Franco, E-mail: dallabe@disi.unitn.i [Dipartimento Ingegneria e Scienza dell' Informazione, Universita di Trento, and INFN Trento, via Sommarive 14, 38123 Povo di Trento (Italy); Boscardin, Maurizio [Fondazione Bruno Kessler (FBK-irst), via Sommarive 18, 38123 Povo di Trento (Italy); Bosisio, Luciano [Dipartimento di Fisica, Universita di Trieste, and INFN Trieste, via A. Valerio 2, 34127 Trieste (Italy); Koehler, Michael; Parzefall, Ulrich [Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg (Germany); Ronchin, Sabina [Fondazione Bruno Kessler (FBK-irst), via Sommarive 18, 38123 Povo di Trento (Italy); Wiik, Liv [Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg (Germany); Zoboli, Andrea [Dipartimento Ingegneria e Scienza dell' Informazione, Universita di Trento, and INFN Trento, via Sommarive 14, 38123 Povo di Trento (Italy); Zorzi, Nicola [Fondazione Bruno Kessler (FBK-irst), via Sommarive 18, 38123 Povo di Trento (Italy)

2010-12-11

In this work, we report on the noise and signal properties of n-on-p, 3D Double-Side Double Type Column (3D-DDTC) detectors fabricated at FBK-irst (Trento, Italy). Compared to full 3D detectors, devices made with this approach allow for a simpler fabrication process, but the efficiency and speed of the charge collection process critically depend on the column overlap and should be carefully evaluated. Measurements were performed on detectors in the microstrip configuration coupled to the ATLAS ABCD3T binary read-out. Spatially resolved signal efficiency tests made with a pulsed infrared laser setup and charge collection efficiency tests made with a {beta} source setup are here reported.

Ultrasonographic analysis in vitro of parietal thickness of lower limb varicose veins.

Science.gov (United States)

Bruschi, E; Como, G; Zuiani, C; Segatto, E; Rocco, M; Biasi, G; Bazzocchi, M

2006-09-01

The aim of this study was to evaluate the ability of ultrasound (US) to measure the parietal thickness of varicose veins. In a blind in vitro analysis, 28 great saphenous veins, obtained after stripping surgery from 28 patients with chronic venous insufficiency, were examined with a digital US scanner ATL-HDI5000, linear 5-1 to 2-MHz broadband probe, compound imaging technique and analogic-digital zooming. We obtained one to three progressive measurements for each vein wall (total 67 parietal thicknesses). The samples, fixed in formalin, were sent to the pathology laboratory: sections were obtained at the same level of the sonographic planes, and images were obtained by digital camera mounted on an optical microscope. Measurements obtained at histology were considered as the gold standard. K-statistic was applied to compare sonographic and histologic measurements. Considering only the hypoechoic wall portion, 29/29 (100%) diagnoses of hypotrophy (K=0.91), 19/22 (86%) diagnoses of normotrophy (K=0,47) and 12/16 (75%) diagnoses of hypertrophy (K=0.7) were obtained by sonography. In our preliminary experience, the in vitro study of varicose veins allows precise, at least morphological, detection of hypotrophic walls. If these preliminary data are confirmed in vivo, sonography could be used to discriminate patients eligible for conservative treatment instead of surgery.

Functional Heterogeneity in Posterior Parietal Cortex Across Attention and Episodic Memory Retrieval

Science.gov (United States)

Hutchinson, J. Benjamin; Uncapher, Melina R.; Weiner, Kevin S.; Bressler, David W.; Silver, Michael A.; Preston, Alison R.; Wagner, Anthony D.

2014-01-01

While attention is critical for event memory, debate has arisen regarding the extent to which posterior parietal cortex (PPC) activation during episodic retrieval reflects engagement of PPC-mediated mechanisms of attention. Here, we directly examined the relationship between attention and memory, within and across subjects, using functional magnetic resonance imaging attention-mapping and episodic retrieval paradigms. During retrieval, 4 functionally dissociable PPC regions were identified. Specifically, 2 PPC regions positively tracked retrieval outcomes: lateral intraparietal sulcus (latIPS) indexed graded item memory strength, whereas angular gyrus (AnG) tracked recollection. By contrast, 2 other PPC regions demonstrated nonmonotonic relationships with retrieval: superior parietal lobule (SPL) tracked retrieval reaction time, consistent with a graded engagement of top-down attention, whereas temporoparietal junction displayed a complex pattern of below-baseline retrieval activity, perhaps reflecting disengagement of bottom-up attention. Analyses of retrieval effects in PPC topographic spatial attention maps (IPS0-IPS5; SPL1) revealed that IPS5 and SPL1 exhibited a nonmonotonic relationship with retrieval outcomes resembling that in the SPL region, further suggesting that SPL activation during retrieval reflects top-down attention. While demands on PPC attention mechanisms vary during retrieval attempts, the present functional parcellation of PPC indicates that 2 additional mechanisms (mediated by latIPS and AnG) positively track retrieval outcomes. PMID:23019246

p-type ZnO films with solid-source phosphorus doping by molecular-beam epitaxy

International Nuclear Information System (INIS)

Xiu, F.X.; Yang, Z.; Mandalapu, L.J.; Liu, J.L.; Beyermann, W. P.

2006-01-01

Phosphorus-doped p-type ZnO films were grown on r-plane sapphire substrates using molecular-beam epitaxy with a solid-source GaP effusion cell. X-ray diffraction spectra and reflection high-energy electron diffraction patterns indicate that high-quality single crystalline (1120) ZnO films were obtained. Hall and resistivity measurements show that the phosphorus-doped ZnO films have high hole concentrations and low resistivities at room temperature. Photoluminescence (PL) measurements at 8 K reveal a dominant acceptor-bound exciton emission with an energy of 3.317 eV. The acceptor energy level of the phosphorus dopant is estimated to be 0.18 eV above the valence band from PL spectra, which is also consistent with the temperature dependence of PL measurements

Counteracting Fatigue in Multiple Sclerosis with Right Parietal Anodal Transcranial Direct Current Stimulation

OpenAIRE

Hanken, Katrin; Bosse, Mona; M?hrke, Kim; Eling, Paul; Kastrup, Andreas; Antal, Andrea; Hildebrandt, Helmut

2016-01-01

BACKGROUND: Fatigue in multiple sclerosis (MS) patients appears to correlate with vigilance decrement as reflected in an increase in reaction time (RT) and errors with prolonged time-on-task. OBJECTIVES: The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS) over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. METHODS: In study I, a randomized double-blind placebo-controll...

P53 suppresses expression of the 14-3-3gamma oncogene

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Qi Wenqing

2011-08-01

Full Text Available Abstract Background 14-3-3 proteins are a family of highly conserved proteins that are involved in a wide range of cellular processes. Recent evidence indicates that some of these proteins have oncogenic activity and that they may promote tumorigenesis. We previously showed that one of the 14-3-3 family members, 14-3-3gamma, is over expressed in human lung cancers and that it can induce transformation of rodent cells in vitro. Methods qRTPCR and Western blot analysis were performed to examine 14-3-3gamma expression in non-small cell lung cancers (NSCLC. Gene copy number was analyzed by qPCR. P53 mutations were detected by direct sequencing and also by western blot. CHIP and yeast one hybrid assays were used to detect p53 binding to 14-3-3gamma promoter. Results Quantitative rtPCR results showed that the expression level of 14-3-3gamma was elevated in the majority of NSCLC that we examined which was also consistent with protein expression. Further analysis of the expression pattern of 14-3-3gamma in lung tumors showed a correlation with p53 mutations suggesting that p53 might suppress 14-3-3 gamma expression. Analysis of the gamma promoter sequence revealed the presence of a p53 consensus binding motif and in vitro assays demonstrated that wild-type p53 bound to this motif when activated by ionizing radiation. Deletion of the p53 binding motif eliminated p53's ability to suppress 14-3-3gamma expression. Conclusion Increased expression of 14-3-3gamma in lung cancer coincides with loss of functional p53. Hence, we propose that 14-3-3gamma's oncogenic activities cooperate with loss of p53 to promote lung tumorigenesis.

Uncertain relational reasoning in the parietal cortex.

Science.gov (United States)

Ragni, Marco; Franzmeier, Imke; Maier, Simon; Knauff, Markus

2016-04-01

The psychology of reasoning is currently transitioning from the study of deductive inferences under certainty to inferences that have degrees of uncertainty in both their premises and conclusions; however, only a few studies have explored the cortical basis of uncertain reasoning. Using transcranial magnetic stimulation (TMS), we show that areas in the right superior parietal lobe (rSPL) are necessary for solving spatial relational reasoning problems under conditions of uncertainty. Twenty-four participants had to decide whether a single presented order of objects agreed with a given set of indeterminate premises that could be interpreted in more than one way. During the presentation of the order, 10-Hz TMS was applied over the rSPL or a sham control site. Right SPL TMS during the inference phase disrupted performance in uncertain relational reasoning. Moreover, we found differences in the error rates between preferred mental models, alternative models, and inconsistent models. Our results suggest that different mechanisms are involved when people reason spatially and evaluate different kinds of uncertain conclusions. Copyright © 2016 Elsevier Inc. All rights reserved.

Surface photovoltage study of InP and Zn3P2

International Nuclear Information System (INIS)

Thurgate, S.M.; Lacuesta, T.D.; Huck, N.R.

1989-01-01

The surface photovoltage spectra of InP and Zn 3 P 2 were measured using a Kelvin probe to determine the contact potential difference between the sample and the probe as a function of the wavelength of illuminating light. The features in the resulting spectra were found to be sensitive to ion bombardment. The photovoltage spectra obtained from the InP differed from previously reported SPC spectra in that it showed clear evidence of surface states (or interfacial states) at 0.86 eV and 0.68 eV above VBM. It was found that the features in the spectrum of Zn 3 P 2 were reduced by ion bombardment, but not removed completely, whereas the features in the InP spectra were completely removed. Exposure of the ion bombarded urface to air restored the features of Zn 3 P 2 but only produced a small change in the spectrum of the InP. The loss of features in the InP spectra can be attributed to damage in the substrate caused by the ion bombardment even though the oxide layer was not removed before the damage occurred. Zn 3 P 2 was not as sensitive to ion damage as InP. (orig.)

Alignment of Ar+ [3P]4p2P03/2 satellite state from the polarization analysis of fluorescent radiation after photoionization

International Nuclear Information System (INIS)

Yenen, O.; McLaughlin, K.W.; Jaecks, D.H.

1997-01-01

The measurement of the polarization of radiation from satellite states of Ar + formed after the photoionization of Ar provides detailed information about the nature of doubly excited states, magnetic sublevel cross sections and partial wave ratios of the photo-ejected electrons. Since the formation of these satellite states is a weak process, it is necessary to use a high flux beam of incoming photons. In addition, in order to resolve the many narrow doubly excited Ar resonances, the incoming photons must have a high resolution. The characteristics of the beam line 9.0.1 of the Advanced Light Source fulfill these requirements. The authors determined the polarization of 4765 Angstrom fluorescence from the Ar + [ 3 P] 4p 2 P 3/2 0 satellite state formed after photoionization of Ar by photons from the 9.0.1 beam line of ALS in the 35.620-38.261 eV energy range using a resolution of approximately 12,700. This is accomplished by measuring the intensities of the fluorescent light polarized parallel (I parallel) and perpendicular (I perpendicular) to the polarization axis of the incident synchrotron radiation using a Sterling Optics 105MB polarizing filter. The optical system placed at 90 degrees with respect to the polarization axis of the incident light had a narrow band interference filter (δλ=0.3 nm) to isolate the fluorescent radiation

Abnormal parietal function in conversion paresis.

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Marije van Beilen

Full Text Available The etiology of medically unexplained symptoms such as conversion disorder is poorly understood. This is partly because the interpretation of neuroimaging results in conversion paresis has been complicated by the use of different control groups, tasks and statistical comparisons. The present study includes these different aspects in a single data set. In our study we included both normal controls and feigners to control for conversion paresis. We studied both movement execution and imagery, and we contrasted both within-group and between-group activation. Moreover, to reveal hemisphere-specific effects that have not been reported before, we performed these analyses using both flipped and unflipped data. This approach resulted in the identification of abnormal parietal activation which was specific for conversion paresis patients. Patients also showed reduced activity in the prefrontal cortex, supramarginal gyrus and precuneus, including hemisphere-specific activation that is lateralized in the same hemisphere, regardless of right- or left-sided paresis. We propose that these regions are candidates for an interface between psychological mechanisms and disturbed higher-order motor control. Our study presents an integrative neurophysiological view of the mechanisms that contribute to the etiology of this puzzling psychological disorder, which can be further investigated with other types of conversion symptoms.

Post test analysis of TEPSS tests -P2-, -P3-, -P5- and -P7- using the system code RELAP5/MOD 3.2

International Nuclear Information System (INIS)

Luebbesmeyer, D.

2000-01-01

For the PANDA-Test-Facility (TEPSS configuration) post-test calculations and analyses have been performed for experiment -P2- (Early Start), -P3- (PCC start up), -P5- (Symmetric case, Two PCCs only) and -P7- (Severe Accident). Post test calculations have been performed with the system code RELAP5/Mod 3.2 using two different nodalization of the PANDA facility namely a basis nodalization and a much reduced one. The general trend of the calculations can be summarised: RELAP5/Mod3.2 calculated the general trends of the experiments sufficiently accurate; Using the reduced nodalization the results seem to be slightly more accurate than for the basic nodalization; On the other hand, calculations based on the reduced nodalization are not significantly faster than those with basic nodalization; The mass error is in the order of 200 to 900 kg. (author)

Frontal Parietal Control Network Regulates the Anti-Correlated Default and Dorsal Attention Networks

OpenAIRE

Gao, Wei; Lin, Weili

2011-01-01

Recent reports demonstrate the anti-correlated behaviors between the default and the dorsal attention (DA) networks. We aimed to investigate the roles of the frontal parietal control (FPC) network in regulating the two anti-correlated networks through three experimental conditions, including resting, continuous self-paced/attended sequential finger tapping (FT), and natural movie watching (MW), respectively. The two goal-directed tasks were chosen to engage either one of the two competing net...

Counteracting fatigue in multiple sclerosis with right parietal anodal transcranial direct current stimulation

OpenAIRE

Katrin Hanken; Katrin Hanken; Mona Bosse; Kim Möhrke; Paul Eling; Andreas Kastrup; Andrea Antal; Helmut Hildebrandt; Helmut Hildebrandt

2016-01-01

Background: Fatigue in multiple sclerosis (MS) patients appears to correlate with vigilance decrement as reflected in an increase in reaction time and errors with prolonged time-on-task. Objectives: The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS) over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. Methods: In study I, a randomized double-blind placebo-controlled study, anoda...

Dominant lymph drainage patterns in the occipital and parietal regions: evaluation of lymph nodes in patients with skin cancer of the head.

Science.gov (United States)

Maeda, Taku; Yamamoto, Yuhei; Furukawa, Hiroshi; Oyama, Akihiko; Funayama, Emi; Murao, Naoki; Hayashi, Toshihiko

2017-08-01

The purpose of this study was to evaluate the superficial lymph drainage patterns of primary skin cancers of the head arising from the occipital or parietal region. The dominant patterns of lymph drainage were retrospectively reviewed in eight patients aged 36-85 years with skin cancers in the occipital or parietal region in whom sentinel lymph node biopsy or lymph node dissection had been performed at Hokkaido University Hospital between January 1981 and December 2015. Lymph drainage was mainly to the occipital (6/8, 75%), level II (5/8, 63%), and level V lymph nodes (5/8, 63%). Of the six patients with drainage to the occipital lymph nodes, four (67%) also had drainage to level V nodes. The dominant lymph drainage pattern in patients with skin cancer arising from the occipital or parietal region was to the occipital, level II, and level V lymph nodes. Further, lymph tended to drain directly from the occipital region to the level V lymph nodes.

Midfrontal Theta and Posterior Parietal Alpha Band Oscillations Support Conflict Resolution in a Masked Affective Priming Task.

Science.gov (United States)

Jiang, Jun; Bailey, Kira; Xiao, Xiao

2018-01-01

Past attempts to characterize the neural mechanisms of affective priming have conceptualized it in terms of classic cognitive conflict, but have not examined the neural oscillatory mechanisms of subliminal affective priming. Using behavioral and electroencephalogram (EEG) time frequency (TF) analysis, the current study examines the oscillatory dynamics of unconsciously triggered conflict in an emotional facial expressions version of the masked affective priming task. The results demonstrate that the power dynamics of conflict are characterized by increased midfrontal theta activity and suppressed parieto-occipital alpha activity. Across-subject and within-trial correlation analyses further confirmed this pattern. Phase synchrony and Granger causality analyses (GCAs) revealed that the fronto-parietal network was involved in unconscious conflict detection and resolution. Our findings support a response conflict account of affective priming, and reveal the role of the fronto-parietal network in unconscious conflict control.

Midfrontal Theta and Posterior Parietal Alpha Band Oscillations Support Conflict Resolution in a Masked Affective Priming Task

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Jun Jiang

2018-05-01

Full Text Available Past attempts to characterize the neural mechanisms of affective priming have conceptualized it in terms of classic cognitive conflict, but have not examined the neural oscillatory mechanisms of subliminal affective priming. Using behavioral and electroencephalogram (EEG time frequency (TF analysis, the current study examines the oscillatory dynamics of unconsciously triggered conflict in an emotional facial expressions version of the masked affective priming task. The results demonstrate that the power dynamics of conflict are characterized by increased midfrontal theta activity and suppressed parieto-occipital alpha activity. Across-subject and within-trial correlation analyses further confirmed this pattern. Phase synchrony and Granger causality analyses (GCAs revealed that the fronto-parietal network was involved in unconscious conflict detection and resolution. Our findings support a response conflict account of affective priming, and reveal the role of the fronto-parietal network in unconscious conflict control.

New superhindered polydentate polyphosphine ligands P(CH2CH2P(t)Bu2)3, PhP(CH2CH2P(t)Bu2)2, P(CH2CH2CH2P(t)Bu2)3, and their ruthenium(II) chloride complexes.

Science.gov (United States)

Gilbert-Wilson, Ryan; Field, Leslie D; Bhadbhade, Mohan M

2012-03-05

The synthesis and characterization of the extremely hindered phosphine ligands, P(CH(2)CH(2)P(t)Bu(2))(3) (P(2)P(3)(tBu), 1), PhP(CH(2)CH(2)P(t)Bu(2))(2) (PhP(2)P(2)(tBu), 2), and P(CH(2)CH(2)CH(2)P(t)Bu(2))(3) (P(3)P(3)(tBu), 3) are reported, along with the synthesis and characterization of ruthenium chloro complexes RuCl(2)(P(2)P(3)(tBu)) (4), RuCl(2)(PhP(2)P(2)(tBu)) (5), and RuCl(2)(P(3)P(3)(tBu)) (6). The bulky P(2)P(3)(tBu) (1) and P(3)P(3)(tBu) (3) ligands are the most sterically encumbered PP(3)-type ligands so far synthesized, and in all cases, only three phosphorus donors are able to bind to the metal center. Complexes RuCl(2)(PhP(2)P(2)(tBu)) (5) and RuCl(2)(P(3)P(3)(tBu)) (6) were characterized by crystallography. Low temperature solution and solid state (31)P{(1)H} NMR were used to demonstrate that the structure of RuCl(2)(P(2)P(3)(tBu)) (4) is probably analogous to that of RuCl(2)(PhP(2)P(2)(tBu)) (5) which had been structurally characterized.

Photoelectric characteristics of CH3NH3PbI3/p-Si heterojunction

Science.gov (United States)

Yamei, Wu; Ruixia, Yang; Hanmin, Tian; Shuai, Chen

2016-05-01

Organic-inorganic hybrid perovskite CH3NH3PbI3 film is prepared on p-type silicon substrate using the one-step solution method to form a CH3NH3PbI3/p-Si heterojunction. The film morphology and structure are characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The photoelectric properties of the CH3NH3PbI3/p-Si heterojunction are studied by testing the current-voltage (I-V) with and without illumination and capacitance-voltage (C-V) characteristics. It turns out from the I-V curve without illumination that the CH3NH3PbI3/p-Si heterojunction has a rectifier feature with the rectification ratio over 70 at the bias of ±5 V. Also, there appears a photoelectric conversion phenomenon on this heterojunction with a short circuit current (Isc) of 0.16 μA and an open circuit voltage (Voc) of about 10 mV The high frequency C-V characteristic of the Ag/CH3NH3PbI3/p-Si heterojunction turns out to be similar to that of the metal-insulator-semiconductor (MIS) structure, and a parallel translation of the C-V curve along the forward voltage axis is found. This parallel translation means the existence of defects at the CH3NH3PbI3/p-Si interface and positive fixed charges in the CH3NH3PbI3 layer. The defects at the interface of the CH3NH3PbI3/p-Si heterojunction result in the dramatic decline of the Voc. Besides, the C-V test of CH3NH3PbI3 film shows a non-linear dielectric property and the dielectric value is about 4.64 as calculated. Project supported by the Hebei Province Natural Science Foundation of China (No. F2014202184) and the Tianjin Natural Science Foundation of China (No. 15JCZDJC37800).

Role of the right inferior parietal cortex in auditory selective attention: An rTMS study.

Science.gov (United States)

Bareham, Corinne A; Georgieva, Stanimira D; Kamke, Marc R; Lloyd, David; Bekinschtein, Tristan A; Mattingley, Jason B

2018-02-01

Selective attention is the process of directing limited capacity resources to behaviourally relevant stimuli while ignoring competing stimuli that are currently irrelevant. Studies in healthy human participants and in individuals with focal brain lesions have suggested that the right parietal cortex is crucial for resolving competition for attention. Following right-hemisphere damage, for example, patients may have difficulty reporting a brief, left-sided stimulus if it occurs with a competitor on the right, even though the same left stimulus is reported normally when it occurs alone. Such "extinction" of contralesional stimuli has been documented for all the major sense modalities, but it remains unclear whether its occurrence reflects involvement of one or more specific subregions of the temporo-parietal cortex. Here we employed repetitive transcranial magnetic stimulation (rTMS) over the right hemisphere to examine the effect of disruption of two candidate regions - the supramarginal gyrus (SMG) and the superior temporal gyrus (STG) - on auditory selective attention. Eighteen neurologically normal, right-handed participants performed an auditory task, in which they had to detect target digits presented within simultaneous dichotic streams of spoken distractor letters in the left and right channels, both before and after 20 min of 1 Hz rTMS over the SMG, STG or a somatosensory control site (S1). Across blocks, participants were asked to report on auditory streams in the left, right, or both channels, which yielded focused and divided attention conditions. Performance was unchanged for the two focused attention conditions, regardless of stimulation site, but was selectively impaired for contralateral left-sided targets in the divided attention condition following stimulation of the right SMG, but not the STG or S1. Our findings suggest a causal role for the right inferior parietal cortex in auditory selective attention. Copyright © 2017 Elsevier Ltd. All rights

Comparing TMS perturbations to occipital and parietal cortices in concurrent TMS-fMRI studies-Methodological considerations

DEFF Research Database (Denmark)

Leitao, Joana; Thielscher, Axel; Tuennerhoff, Johannes

2017-01-01

the effect of transient perturbations on functional brain organization. This concurrent TMS-fMRI study applied TMS perturbation to occipital and parietal cortices with the aim to 'mimick' neglect and hemianopia. Based on the challenges and interpretational limitations of our own study we aim to provide...

Open-Source 3D-Printable Optics Equipment

Science.gov (United States)

Zhang, Chenlong; Anzalone, Nicholas C.; Faria, Rodrigo P.; Pearce, Joshua M.

2013-01-01

Just as the power of the open-source design paradigm has driven down the cost of software to the point that it is accessible to most people, the rise of open-source hardware is poised to drive down the cost of doing experimental science to expand access to everyone. To assist in this aim, this paper introduces a library of open-source 3-D-printable optics components. This library operates as a flexible, low-cost public-domain tool set for developing both research and teaching optics hardware. First, the use of parametric open-source designs using an open-source computer aided design package is described to customize the optics hardware for any application. Second, details are provided on the use of open-source 3-D printers (additive layer manufacturing) to fabricate the primary mechanical components, which are then combined to construct complex optics-related devices. Third, the use of the open-source electronics prototyping platform are illustrated as control for optical experimental apparatuses. This study demonstrates an open-source optical library, which significantly reduces the costs associated with much optical equipment, while also enabling relatively easily adapted customizable designs. The cost reductions in general are over 97%, with some components representing only 1% of the current commercial investment for optical products of similar function. The results of this study make its clear that this method of scientific hardware development enables a much broader audience to participate in optical experimentation both as research and teaching platforms than previous proprietary methods. PMID:23544104

Open-source 3D-printable optics equipment.

Science.gov (United States)

Zhang, Chenlong; Anzalone, Nicholas C; Faria, Rodrigo P; Pearce, Joshua M

2013-01-01

Just as the power of the open-source design paradigm has driven down the cost of software to the point that it is accessible to most people, the rise of open-source hardware is poised to drive down the cost of doing experimental science to expand access to everyone. To assist in this aim, this paper introduces a library of open-source 3-D-printable optics components. This library operates as a flexible, low-cost public-domain tool set for developing both research and teaching optics hardware. First, the use of parametric open-source designs using an open-source computer aided design package is described to customize the optics hardware for any application. Second, details are provided on the use of open-source 3-D printers (additive layer manufacturing) to fabricate the primary mechanical components, which are then combined to construct complex optics-related devices. Third, the use of the open-source electronics prototyping platform are illustrated as control for optical experimental apparatuses. This study demonstrates an open-source optical library, which significantly reduces the costs associated with much optical equipment, while also enabling relatively easily adapted customizable designs. The cost reductions in general are over 97%, with some components representing only 1% of the current commercial investment for optical products of similar function. The results of this study make its clear that this method of scientific hardware development enables a much broader audience to participate in optical experimentation both as research and teaching platforms than previous proprietary methods.

Open-source 3D-printable optics equipment.

Directory of Open Access Journals (Sweden)

Chenlong Zhang

Full Text Available Just as the power of the open-source design paradigm has driven down the cost of software to the point that it is accessible to most people, the rise of open-source hardware is poised to drive down the cost of doing experimental science to expand access to everyone. To assist in this aim, this paper introduces a library of open-source 3-D-printable optics components. This library operates as a flexible, low-cost public-domain tool set for developing both research and teaching optics hardware. First, the use of parametric open-source designs using an open-source computer aided design package is described to customize the optics hardware for any application. Second, details are provided on the use of open-source 3-D printers (additive layer manufacturing to fabricate the primary mechanical components, which are then combined to construct complex optics-related devices. Third, the use of the open-source electronics prototyping platform are illustrated as control for optical experimental apparatuses. This study demonstrates an open-source optical library, which significantly reduces the costs associated with much optical equipment, while also enabling relatively easily adapted customizable designs. The cost reductions in general are over 97%, with some components representing only 1% of the current commercial investment for optical products of similar function. The results of this study make its clear that this method of scientific hardware development enables a much broader audience to participate in optical experimentation both as research and teaching platforms than previous proprietary methods.

MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject

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Andreas A Ioannides

2013-08-01

Full Text Available Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1 and motor (M1 cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45 to 70 Hz activity at latencies of 20 to 50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occured in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex.

Projections to early visual areas V1 and V2 in the calcarine fissure from parietal association areas in the macaque.

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Elena eBorra

2011-06-01

Full Text Available Non-extrastriate projections to area V1 in monkeys, now demonstrated by several anatomical studies, are potential substrates of physiologically documented multisensory effects in primary sensory areas. The full network of projections among association and primary areas, however, is likely to be complex and is still only partially understood. In the present report, we used the anterograde tracer biotinylated dextran amine to investigate projections to areas V1 and V2 from subdivisions of the parietal association cortex in macaque. Parietal cortex was chosen to allow comparisons between projections from this higher association area and from other previously reported areas. In addition, we were interested in further elucidating pathways to areas V1 and V2 from parietal areas, as potentially contributing to attention and active vision. Of eight cases, three brains had projections only to area V2, and the five others projected to both areas V1 and V2. Terminations in area V1 were sparse. These were located in supragranular layers I, II, upper III; occasionally in IVB; and in layer VI. Terminations in V2 were denser, and slightly more prevalent in the supragranular layers. For both areas, terminations were in the calcarine region, corresponding to the representation of the peripheral visual field. By reconstructions of single axons, we demonstrated that four of nine axons had collaterals, either to V1 and V2 (n=1 or to area V1 and a ventral area likely to be TEO (n=3. In area V1, axons extended divergently in layer VI as well as layer I. Overall, these and previous results suggest a nested connectivity architecture, consisting of multiple direct and indirect recurrent projections from association areas to area V1. Terminations in area V1 are not abundant, but could be potentiated by the network of indirect connections.

Source and LINAC3 studies

CERN Document Server

Bellodi, G

2017-01-01

In the framework of the LHC Ion Injector Upgrade pro-gramme (LIU), several activities have been carried out in2016 to improve the ion source and Linac3 performance,with the goal to increase the beam current routinely deliv-ered to LEIR. The extraction region of the GTS-LHC ionsource was upgraded with enlarged vacuum chamber aper-tures and the addition of an einzel lens, yielding highertransmission through the rest of the machine. Also, a seriesof experiments have been performed to study the effects ofdouble frequency mixing on the afterglow performance ofthe source after installation of a Travelling Wave Tube Am-plifier (TWTA) as secondary microwave source at variablefrequency. Measurements have been carried out at a dedi-cated oven test stand for better understanding of the ionsource performance. Finally, several MD sessions werededicated to the study and characterization of the strippingfoils, after evidence of degradation in time was discoveredin the 2015 run.

Eukaryotic ribonucleases P/MRP: the crystal structure of the P3 domain.

Science.gov (United States)

Perederina, Anna; Esakova, Olga; Quan, Chao; Khanova, Elena; Krasilnikov, Andrey S

2010-02-17

Ribonuclease (RNase) P is a site-specific endoribonuclease found in all kingdoms of life. Typical RNase P consists of a catalytic RNA component and a protein moiety. In the eukaryotes, the RNase P lineage has split into two, giving rise to a closely related enzyme, RNase MRP, which has similar components but has evolved to have different specificities. The eukaryotic RNases P/MRP have acquired an essential helix-loop-helix protein-binding RNA domain P3 that has an important function in eukaryotic enzymes and distinguishes them from bacterial and archaeal RNases P. Here, we present a crystal structure of the P3 RNA domain from Saccharomyces cerevisiae RNase MRP in a complex with RNase P/MRP proteins Pop6 and Pop7 solved to 2.7 A. The structure suggests similar structural organization of the P3 RNA domains in RNases P/MRP and possible functions of the P3 domains and proteins bound to them in the stabilization of the holoenzymes' structures as well as in interactions with substrates. It provides the first insight into the structural organization of the eukaryotic enzymes of the RNase P/MRP family.

Human Occipital and Parietal GABA Selectively Influence Visual Perception of Orientation and Size.

Science.gov (United States)

Song, Chen; Sandberg, Kristian; Andersen, Lau Møller; Blicher, Jakob Udby; Rees, Geraint

2017-09-13

GABA is the primary inhibitory neurotransmitter in human brain. The level of GABA varies substantially across individuals, and this variability is associated with interindividual differences in visual perception. However, it remains unclear whether the association between GABA level and visual perception reflects a general influence of visual inhibition or whether the GABA levels of different cortical regions selectively influence perception of different visual features. To address this, we studied how the GABA levels of parietal and occipital cortices related to interindividual differences in size, orientation, and brightness perception. We used visual contextual illusion as a perceptual assay since the illusion dissociates perceptual content from stimulus content and the magnitude of the illusion reflects the effect of visual inhibition. Across individuals, we observed selective correlations between the level of GABA and the magnitude of contextual illusion. Specifically, parietal GABA level correlated with size illusion magnitude but not with orientation or brightness illusion magnitude; in contrast, occipital GABA level correlated with orientation illusion magnitude but not with size or brightness illusion magnitude. Our findings reveal a region- and feature-dependent influence of GABA level on human visual perception. Parietal and occipital cortices contain, respectively, topographic maps of size and orientation preference in which neural responses to stimulus sizes and stimulus orientations are modulated by intraregional lateral connections. We propose that these lateral connections may underlie the selective influence of GABA on visual perception. SIGNIFICANCE STATEMENT GABA, the primary inhibitory neurotransmitter in human visual system, varies substantially across individuals. This interindividual variability in GABA level is linked to interindividual differences in many aspects of visual perception. However, the widespread influence of GABA raises the

Human Occipital and Parietal GABA Selectively Influence Visual Perception of Orientation and Size

Science.gov (United States)

Andersen, Lau Møller; Blicher, Jakob Udby

2017-01-01

GABA is the primary inhibitory neurotransmitter in human brain. The level of GABA varies substantially across individuals, and this variability is associated with interindividual differences in visual perception. However, it remains unclear whether the association between GABA level and visual perception reflects a general influence of visual inhibition or whether the GABA levels of different cortical regions selectively influence perception of different visual features. To address this, we studied how the GABA levels of parietal and occipital cortices related to interindividual differences in size, orientation, and brightness perception. We used visual contextual illusion as a perceptual assay since the illusion dissociates perceptual content from stimulus content and the magnitude of the illusion reflects the effect of visual inhibition. Across individuals, we observed selective correlations between the level of GABA and the magnitude of contextual illusion. Specifically, parietal GABA level correlated with size illusion magnitude but not with orientation or brightness illusion magnitude; in contrast, occipital GABA level correlated with orientation illusion magnitude but not with size or brightness illusion magnitude. Our findings reveal a region- and feature-dependent influence of GABA level on human visual perception. Parietal and occipital cortices contain, respectively, topographic maps of size and orientation preference in which neural responses to stimulus sizes and stimulus orientations are modulated by intraregional lateral connections. We propose that these lateral connections may underlie the selective influence of GABA on visual perception. SIGNIFICANCE STATEMENT GABA, the primary inhibitory neurotransmitter in human visual system, varies substantially across individuals. This interindividual variability in GABA level is linked to interindividual differences in many aspects of visual perception. However, the widespread influence of GABA raises the

Single photon emission computed tomography with N-isopropyl-p-[123I] iodoamphetamine in dementia of the Alzheimer type

International Nuclear Information System (INIS)

Tsunoda, Masahiko; Fujii, Tsutomu; Tanii, Yasuyuki; Yasui, Shinichi; Yuasa, Satoru; Shimizu, Akinori; Kurachi, Masayoshi; Seki, Hiroyasu; Fukuta, Tsutomu.

1989-01-01

Correlation between brain uptake of N-isopropyl-p-[I-123]iodoamphetamine (I-123 IMP), as shown on single photon emission computed tomography (SPECT) scans, and clinical stages was examined in 8 patients with Alzheimer type dementia. The patients were clinically staged as Stage I (3), Stage II (3), or Stage III (2). The count ratio of each cerebral lobe to the cerebellum was calculated on horizontal SPECT scans. Stage I patients had a decreased I-123 IMP uptake in the temporal and parietal lobes. The decreased uptake in these areas became marked in Stage II patients, with diffusely slight uptake of I-123 IMP in the brain. In Stage III patients, the uptake of I-123 IMP was markedly decreased in the whole brain, including temporal, parietal, and frontal lobes. For five patients of Stage II and III, bilateral differences in the cerebral hemispheres were observed, corresponding to neurologic symptoms. Iodine-123 IMP SPECT was thus considered useful in clinically evaluating Alzheimer type dementia and in determining degenerative process of this disease. (Namekawa, K)

Time-dependent anisotropic distributed source capability in transient 3-d transport code tort-TD

International Nuclear Information System (INIS)

Seubert, A.; Pautz, A.; Becker, M.; Dagan, R.

2009-01-01

The transient 3-D discrete ordinates transport code TORT-TD has been extended to account for time-dependent anisotropic distributed external sources. The extension aims at the simulation of the pulsed neutron source in the YALINA-Thermal subcritical assembly. Since feedback effects are not relevant in this zero-power configuration, this offers a unique opportunity to validate the time-dependent neutron kinetics of TORT-TD with experimental data. The extensions made in TORT-TD to incorporate a time-dependent anisotropic external source are described. The steady state of the YALINA-Thermal assembly and its response to an artificial square-wave source pulse sequence have been analysed with TORT-TD using pin-wise homogenised cross sections in 18 prompt energy groups with P 1 scattering order and 8 delayed neutron groups. The results demonstrate the applicability of TORT-TD to subcritical problems with a time-dependent external source. (authors)

Separating recognition processes of declarative memory via anodal tDCS: boosting old item recognition by temporal and new item detection by parietal stimulation.

Science.gov (United States)

Pisoni, Alberto; Turi, Zsolt; Raithel, Almuth; Ambrus, Géza Gergely; Alekseichuk, Ivan; Schacht, Annekathrin; Paulus, Walter; Antal, Andrea

2015-01-01

There is emerging evidence from imaging studies that parietal and temporal cortices act together to achieve successful recognition of declarative information; nevertheless, the precise role of these regions remains elusive. To evaluate the role of these brain areas in declarative memory retrieval, we applied bilateral tDCS, with anode over the left and cathode over the right parietal or temporal cortices separately, during the recognition phase of a verbal learning paradigm using a balanced old-new decision task. In a parallel group design, we tested three different groups of healthy adults, matched for demographic and neurocognitive status: two groups received bilateral active stimulation of either the parietal or the temporal cortex, while a third group received sham stimulation. Accuracy, discriminability index (d') and reaction times of recognition memory performance were measurements of interest. The d' sensitivity index and accuracy percentage improved in both active stimulation groups, as compared with the sham one, while reaction times remained unaffected. Moreover, the analysis of accuracy revealed a different effect of tDCS for old and new item recognition. While the temporal group showed enhanced performance for old item recognition, the parietal group was better at correctly recognising new ones. Our results support an active role of both of these areas in memory retrieval, possibly underpinning different stages of the recognition process.

Dissociable Changes of Frontal and Parietal Cortices in Inherent Functional Flexibility across the Human Life Span.

Science.gov (United States)

Yin, Dazhi; Liu, Wenjing; Zeljic, Kristina; Wang, Zhiwei; Lv, Qian; Fan, Mingxia; Cheng, Wenhong; Wang, Zheng

2016-09-28

Extensive evidence suggests that frontoparietal regions can dynamically update their pattern of functional connectivity, supporting cognitive control and adaptive implementation of task demands. However, it is largely unknown whether this flexibly functional reconfiguration is intrinsic and occurs even in the absence of overt tasks. Based on recent advances in dynamics of resting-state functional resonance imaging (fMRI), we propose a probabilistic framework in which dynamic reconfiguration of intrinsic functional connectivity between each brain region and others can be represented as a probability distribution. A complexity measurement (i.e., entropy) was used to quantify functional flexibility, which characterizes heterogeneous connectivity between a particular region and others over time. Following this framework, we identified both functionally flexible and specialized regions over the human life span (112 healthy subjects from 13 to 76 years old). Across brainwide regions, we found regions showing high flexibility mainly in the higher-order association cortex, such as the lateral prefrontal cortex (LPFC), lateral parietal cortex, and lateral temporal lobules. In contrast, visual, auditory, and sensory areas exhibited low flexibility. Furthermore, we observed that flexibility of the right LPFC improved during maturation and reduced due to normal aging, with the opposite occurring for the left lateral parietal cortex. Our findings reveal dissociable changes of frontal and parietal cortices over the life span in terms of inherent functional flexibility. This study not only provides a new framework to quantify the spatiotemporal behavior of spontaneous brain activity, but also sheds light on the organizational principle behind changes in brain function across the human life span. Recent neuroscientific research has demonstrated that the human capability of adaptive task control is primarily the result of the flexible operation of frontal brain networks. However

The gastric acid secretagogue gastrin-releasing peptide and the inhibitor oxyntomodulin do not exert their effect directly on the parietal cell in the rat

DEFF Research Database (Denmark)

Poulsen, Steen Seier; Holst, J J

1988-01-01

in vitro by measuring [14C]-aminopyrine accumulation, a reliable index of H+ generation, in isolated rat parietal cells. However, neither gastrin-releasing peptide nor oxyntomodulin influenced basal acid secretion or histamine-stimulated gastric acid secretion. Electron-microscopic studies of unstimulated...... and histamine-stimulated parietal cells confirmed that the cells retained the normal morphology of intracellular organelles and that the cells responded to physiological stimulation by marked expansion of the intracellular canaliculi....

10 Hz rTMS over right parietal cortex alters sense of agency during self-controlled movements

DEFF Research Database (Denmark)

Ritterband-Rosenbaum, Anina; Karabanov, Anke N; Christensen, Mark Schram

2014-01-01

A large body of fMRI and lesion-literature has provided evidence that the Inferior Parietal Cortex (IPC) is important for sensorimotor integration and sense of agency (SoA). We used repetitive transcranial magnetic stimulation (rTMS) to explore the role of the IPC during a validated SoA detection...

Three-dimensional balanced steady state free precession myocardial perfusion cardiovascular magnetic resonance at 3T using dual-source parallel RF transmission: initial experience.

Science.gov (United States)

Jogiya, Roy; Schuster, Andreas; Zaman, Arshad; Motwani, Manish; Kouwenhoven, Marc; Nagel, Eike; Kozerke, Sebastian; Plein, Sven

2014-11-28

The purpose of this study was to establish the feasibility of three-dimensional (3D) balanced steady-state-free-precession (bSSFP) myocardial perfusion cardiovascular magnetic resonance (CMR) at 3T using local RF shimming with dual-source RF transmission, and to compare it with spoiled gradient echo (TGRE) acquisition. Dynamic contrast-enhanced 3D bSSFP perfusion imaging was performed on a 3T MRI scanner equipped with dual-source RF transmission technology. Images were reconstructed using k-space and time broad-use linear acquisition speed-up technique (k-t BLAST) and compartment based principle component analysis (k-t PCA). In phantoms and volunteers, local RF shimming with dual source RF transmission significantly improved B1 field homogeneity compared with single source transmission (P=0.01). 3D bSSFP showed improved signal-to-noise, contrast-to-noise and signal homogeneity compared with 3D TGRE (29.8 vs 26.9, P=0.045; 23.2 vs 21.6, P=0.049; 14.9% vs 12.4%, p=0.002, respectively). Image quality was similar between bSSFP and TGRE but there were more dark rim artefacts with bSSFP. k-t PCA reconstruction reduced artefacts for both sequences compared with k-t BLAST. In a subset of five patients, both methods correctly identified those with coronary artery disease. Three-dimensional bSSFP myocardial perfusion CMR using local RF shimming with dual source parallel RF transmission at 3T is feasible and improves signal characteristics compared with TGRE. Image artefact remains an important limitation of bSSFP imaging at 3T but can be reduced with k-t PCA.

Excitation function measurements of sup 4 sup 0 Ar(p,3n) sup 3 sup 8 K, sup 4 sup 0 Ar(p,2pn) sup 3 sup 8 Cl and sup 4 sup 0 Ar(p,2p) sup 3 sup 9 Cl reactions

CERN Document Server

Nagatsu, K; Suzuki, K

1999-01-01

For the production of sup 3 sup 8 K, excitation functions of the sup 4 sup 0 Ar(p,3n) sup 3 sup 8 K reaction and its accompanying reactions sup 4 sup 0 Ar(p,2pn) sup 3 sup 8 Cl, and sup 4 sup 0 Ar(p,2p) sup 3 sup 9 Cl were measured at the proton energy of 20.5-39.5 MeV to determine the optimum conditions of irradiation. Target cells containing argon gas were prepared using specially developed tools in an argon-replaced glove box. In the sup 4 sup 0 Ar(p,3n) sup 3 sup 8 K, sup 4 sup 0 Ar(p,2pn) sup 3 sup 8 Cl, and sup 4 sup 0 Ar(p,2p) sup 3 sup 9 Cl reactions, the maximum cross sections were 6.7+-0.7, 34+-3.3 and 11+-1.2mbarn at 37.6, 39.5 and 32.0 MeV, respectively, and the saturation thick target yields were calculated to be 560, 2200, and 1300 sup * MBq/mu A, respectively, at an incident energy of 39.5 MeV ( sup * integral yield above 21 MeV).

Frontal and parietal transcranial magnetic stimulation (TMS) disturbs programming of saccadic eye movements.

Science.gov (United States)

Zangemeister, W H; Canavan, A G; Hoemberg, V

1995-11-01

Transcranial magnetic stimulation (TMS) of human motor cortex typically evoked motor responses. TMS has failed to elicit eye movements in humans, whereas prolongations of saccadic latency have been reported with TMS. In previous studied we demonstrated that saccades can be abolished or saccadic trajectories can be changed through TMS in the 100 msec before saccade onset. This effect was especially marked when TMS was applied parietally. TMS never influenced a saccade in flight. Simulations of predictive experimental saccades that were impaired through TMS of the frontal or parietal cortex demonstrated especially that the dynamics of small saccades were markedly influenced, resulting in a significant decrease in acceleration and amplitude, or an almost complete inhibition. The impact of inhibition through TMS was critically dependent on timing: early TMS (-70 msec) had a much larger inhibitory effect than late TMS (-20 msec) on experimental saccades. Differential timing of TMS in influencing the cortical control signal is demonstrated through simulations of a reciprocally innervated eye movement model that paralleled empirically determined changes in eye movement dynamics after real TMS. There is a reasonable match between the model and the experimental data. We conclude that the inhibitory action of a presaccadic disturbance, such as a TMS pulse, on saccadic programming is inversely related to timing and amplitude of the predicted saccade.

Navigating actions through the rodent parietal cortex

Directory of Open Access Journals (Sweden)

Jonathan R. Whitlock

2014-05-01

Full Text Available The posterior parietal cortex (PPC participates in a manifold of cognitive functions, including visual attention, working memory, spatial processing and movement planning. Given the vast interconnectivity of PPC with sensory and motor areas, it is not surprising that neuronal recordings show that PPC often encodes mixtures of spatial information as well as the movements required to reach a goal. Recent work sought to discern the relative strength of spatial versus motor signaling in PPC by recording single unit activity in PPC of freely behaving rats during selective changes in either the spatial layout of the local environment or in the pattern of locomotor behaviors executed during navigational tasks. The results revealed unequivocally a predominant sensitivity of PPC neurons to locomotor action structure, with subsets of cells even encoding upcoming movements more than 1 second in advance. In light of these and other recent findings in the field, I propose that one of the key contributions of PPC to navigation is the synthesis of goal-directed behavioral sequences, and that the rodent PPC may serve as an apt system to investigate cellular mechanisms for spatial motor planning as traditionally studied in humans and monkeys.

High-efficiency silicon doping of InP and In0.53Ga0.47As in gas source and metalorganic molecular beam epitaxy using silicon tetrabromide

International Nuclear Information System (INIS)

Jackson, S.L.; Fresina, M.T.; Baker, J.E.; Stillman, G.E.

1994-01-01

Efficient vapor source Si doping of InP and In 0.53 Ga 0.47 As have been demonstrated using SiBr 4 as the Si source for both gas source (GSMBE) and metalorganic molecular beam epitaxy (MOMBE). Net electron concentrations ranging from n=2x10 17 to 6.8x10 19 cm -3 and from 9x10 16 to 3x10 19 cm -3 have been obtained for InP and In 0.53 Ga 0.47 As, respectively. Comparison of these data with those for Si 2 H 6 indicate that the Si incorporation efficiency with SiBr 4 is more than 10 000 times greater than with Si 2 H 6 for substrate temperatures in the range of 475≤T s ≤500 degree C. Specular surface morphologies were obtained, even for the most heavily doped samples. While [Si] as high as 1.8x10 20 cm -3 was obtained in InP, the net electron concentrations and 300 K Hall mobilities decrease with increasing [Si] for [Si]>6.8x10 19 cm -3 . Contact resistances as low as R c =3x10 -8 Ω cm 2 were obtained using a nonalloyed Ti/Pt/Au contact to InP layers doped to n=6.3x10 19 cm -3 . During GSMBE growth, an increased Si background concentration ([Si]∼2x10 17 cm -3 ) was observed after extended use of the SiBr 4 source for these heavy doping concentrations. This increased background was not observed in MOMBE-grown material. Depth profiles of pulse-doped structures indicate the absence of memory effects for structures grown by MOMBE

Behaviors of beryllium compensation doping in InGaAsP grown by gas source molecular beam epitaxy

Science.gov (United States)

Ma, Y. J.; Zhang, Y. G.; Gu, Y.; Xi, S. P.; Chen, X. Y.; Liang, Baolai; Juang, Bor-Chau; Huffaker, Diana L.; Du, B.; Shao, X. M.; Fang, J. X.

2017-07-01

We report structural properties as well as electrical and optical behaviors of beryllium (Be)-doped InGaAsP lattice-matched to InP grown by gas source molecular beam epitaxy. P type layers present a high degree of compensation on the order of 1018 cm-3, and for Be densities below 9.5×1017 cm-3, they are found to be n type. Enhanced incorporation of oxygen during Be doping is observed by secondary ion mass spectroscopy. Be in forms of interstitial donors or donor-like Be-O complexes for cell temperatures below 800°C is proposed to account for such anomalous compensation behaviors. A constant photoluminescence energy of 0.98 eV without any Moss-Burstein shift for Be doping levels up to 1018 cm-3 along with increased emission intensity due to passivation effect of Be is also observed. An increasing number of minority carriers tend to relax via Be defect state-related Shockley-Read-Hall recombination with the increase of Be doping density.

Behaviors of beryllium compensation doping in InGaAsP grown by gas source molecular beam epitaxy

Directory of Open Access Journals (Sweden)

Y. J. Ma

2017-07-01

Full Text Available We report structural properties as well as electrical and optical behaviors of beryllium (Be-doped InGaAsP lattice-matched to InP grown by gas source molecular beam epitaxy. P type layers present a high degree of compensation on the order of 1018 cm−3, and for Be densities below 9.5×1017 cm−3, they are found to be n type. Enhanced incorporation of oxygen during Be doping is observed by secondary ion mass spectroscopy. Be in forms of interstitial donors or donor-like Be-O complexes for cell temperatures below 800°C is proposed to account for such anomalous compensation behaviors. A constant photoluminescence energy of 0.98 eV without any Moss-Burstein shift for Be doping levels up to 1018 cm−3 along with increased emission intensity due to passivation effect of Be is also observed. An increasing number of minority carriers tend to relax via Be defect state-related Shockley-Read-Hall recombination with the increase of Be doping density.

Semiconducting La2AuP3, the metallic conductor Ce2AuP3, and other rare-earth gold phosphides Ln2AuP3 with two closely related crystal structures

International Nuclear Information System (INIS)

Eschen, M.; Kotzyba, G.; Kuennen, B.; Jeitschko, W.

2001-01-01

The compounds Ln 2 AuP 3 were synthesized by reaction of the elemental components in evacuated silica tubes. Their crystal structures were determined from single-crystal diffractometer data. The compounds with Ln = La, Ce, and Pr crystallize with an orthorhombic U 2 NiC 3 type structure (Pnma, Z = 4). The structure refinement for Ce 2 AuP 3 resulted in a = 774.14(6) pm, b = 421.11(4) pm, c = 1612.3(1) pm, R = 0.019 for 1410 structure factors and 38 variable parameters. For Pr 2 AuP 3 a residual of R = 0.024 was obtained. Nd 2 AuP 3 crystallizes with a monoclinic distortion of this structure: P2 1 /c, Z = 4, a = 416.14(4) pm, b = 768.87(6) pm, c = 1647.1(2) pm, β = 104.06(1) , R = 0.022 for 1361 F values and 56 variables. The near-neighbor coordinations of the two structures are nearly the same. In both structures the gold and phosphorus atoms form two-dimensionally infinite nets, where the gold atoms are tetrahedrally coordinated by phosphorus atoms with Au-P distances varying between 245.8 and 284.2 pm. Two thirds of the phosphorus atoms form pairs with single-bond distances varying between 217.7 and 218.9 pm. Thus, using oxidation numbers the structures can be rationalized with the formulas (Ln +3 ) 2 [AuP 3 ] -6 and (Ln +3 ) 2 Au +1 (P 2 ) -4 P -3 . Accordingly, La 2 AuP 3 is a diamagnetic semiconductor. Pr 2 AuP 3 is semi-conducting with an antiferromagnetic ground state, showing metamagnetism with a critical field of B c = 0.5(±0.1) T. In contrast, the cerium compound is a metallic conductor, even though its cell volume indicates that the cerium atoms are essentially trivalent, as is also suggested by the ferro- or ferrimagnetic behavior of the compound. (orig.)

P-wave pulse analysis to retrieve source and propagation effects in the case of Vrancea earthquakes

International Nuclear Information System (INIS)

Popescu, E.; Popa, M.; Placinta, A.; Grecu, B.; Radulian, M.

2004-01-01

Seismic source parameters and attenuation structure properties are obtained from the first P-wave pulse analysis and empirical Green's function deconvolution. The P pulse characteristics are combined effects of source and path properties. To reproduce the real source and structure parameters it is crucial to apply a method able to distinguish between the different factors affecting the observed seismograms. For example the empirical Green's function deconvolution method (Hartzell, 1978) allows the retrieval of the apparent source time function or source spectrum corrected for path, site and instrumental effects. The apparent source duration is given by the width of the deconvoluted source pulse and is directly related to the source dimension. Once the source time function established, next we can extract the parameters related to path effects. The difference between the pulse recorded at a given station and the source pulse obtained by deconvolution is a measure of the attenuation along the path from focus to the station. On the other hand, the pulse width variations with azimuth depend critically on the fault plane orientation and source directivity. In favourable circumstances (high signal/noise ratio, high resolution and station coverage), the method of analysis proposed in this paper allows the constraint of the rupture plane among the two nodal planes characterizing the fault plane solution, even for small events. P-wave pulse analysis was applied for 25 Vrancea earthquakes recorded between 1999 and 2003 by the Romanian local network to determine source parameters and attenuation properties. Our results outline high-stress drop seismic energy release with relatively simple rupture process for the considered events and strong lateral variation of attenuation of seismic waves across Carpathians Arc. (authors)

An impaired attentional dwell time after parietal and frontal lesions related to impaired selective attention not unilateral neglect.

Science.gov (United States)

Correani, Alessia; Humphreys, Glyn W

2011-07-01

The attentional blink, a measure of the temporal dynamics of visual processing, has been documented to be more pronounced following brain lesions that are associated with visual neglect. This suggests that, in addition to their spatial bias in attention, neglect patients may have a prolonged dwell time for attention. Here the attentional dwell time was examined in patients with damage focused on either posterior parietal or frontal cortices. In three experiments, we show that there is an abnormally pronounced attentional dwell time, which does not differ in patients with posterior parietal and with frontal lobe lesions, and this is associated with a measure of selective attention but not with measures of spatial bias in selection. These data occurred both when we attempted to match patients and controls for overall differences in performance and when a single set stimulus exposure was used across participants. In Experiments 1 and 2, requiring report of colour-form conjunctions, there was evidence that the patients were also impaired at temporal binding, showing errors in feature combination across stimuli and in reporting in the correct temporal order. In Experiment 3, requiring only the report of features but introducing task switching led to similar results. The data suggest that damage to a frontoparietal network can compromise temporal selection of visual stimuli; however, this is not necessarily related to a deficit in hemispatial visual attention but it is to impaired target selection. We discuss the implications for understanding visual selection.

Analysis of the reaction 3He + p → p + p + d at 2,5 GeV/c 3He nucleus momentum

International Nuclear Information System (INIS)

Blinov, A.V.; Chuvilo, I.V.; Drobot, V.V.

1984-01-01

The experimental data on the reaction 3 He+p → p+p+d obtained by the exposition of an 80 cm liquid hydrogen bubble chamber to the 3 He nucleus beam at 2.5 GeV/c momentum are considered. The angular, momentum and invariant mass distributions, which have been measured, are compared with theoretical calculations performed using the pole model. On the whole a satisfactory agreement between theoretical and experimental data is found in the kinematical region, where pd- rescattering effects are negligible. It is concluded, that 3 He nuclear wave function calculated by means of nonrelativistic potential models falls too sharply with the spectator momenta as compared with the data

Association between auditory P300, psychopathology, and memory function in drug-naïve schizophrenia

Directory of Open Access Journals (Sweden)

Wei-Hung Chang

2014-03-01

Full Text Available The aim of this study was to explore memory deficits and psychopathology and their relationships with P300 in drug-naïve patients with schizophrenia. The Positive and Negative Syndrome Scale (PANSS and the Wechsler Memory Scale—Revised were administered. Auditory event-related potentials elicited by an oddball paradigm were obtained. After controlling for age, sex, the results showed a statistically significant negative correlation between the total PANSS score and P300 amplitude at the parietal position (r = −0.66, p < 0.05. Moreover, visual memory was significantly positively correlated with P300 amplitude at the parietal position (r = 0.67, p < 0.05. After controlling for the duration of illness, the above correlations remained statistically significant. The correlation between P300 and the severity of psychopathology was reconfirmed in drug-naïve patients with schizophrenia. A possible contribution of memory decompensation in P300 among drug-naïve patients with schizophrenia may be considered, and the compensatory or Default Model Network might be a possible explanation of this association.

Larger right posterior parietal volume in action video game experts: a behavioral and voxel-based morphometry (VBM study.

Directory of Open Access Journals (Sweden)

Satoshi Tanaka

Full Text Available Recent studies suggest that action video game players exhibit superior performance in visuospatial cognitive tasks compared with non-game players. However, the neural basis underlying this visuospatial cognitive performance advantage remains largely unknown. The present human behavioral and imaging study compared gray matter volume in action video game experts and non-experts using structural magnetic resonance imaging and voxel-based morphometry analysis. The results revealed significantly larger gray matter volume in the right posterior parietal cortex in experts compared with non-experts. Furthermore, the larger gray matter volume in the right posterior parietal cortex significantly correlated with individual performance in a visual working memory task in experts. These results suggest that differences in brain structure may be linked to extensive video game play, leading to superior visuospatial cognitive performance in action video game experts.

Parietal Fast Sleep Spindle Density Decrease in Alzheimer's Disease and Amnesic Mild Cognitive Impairment

Science.gov (United States)

Gorgoni, Maurizio; Lauri, Giulia; Truglia, Ilaria; Cordone, Susanna; Sarasso, Simone; Scarpelli, Serena; Mangiaruga, Anastasia; D'Atri, Aurora; Tempesta, Daniela; Ferrara, Michele; Marra, Camillo; Rossini, Paolo Maria; De Gennaro, Luigi

2016-01-01

Several studies have identified two types of sleep spindles: fast (13–15 Hz) centroparietal and slow (11–13 Hz) frontal spindles. Alterations in spindle activity have been observed in Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI). Only few studies have separately assessed fast and slow spindles in these patients showing a reduction of fast spindle count, but the possible local specificity of this phenomenon and its relation to cognitive decline severity are not clear. Moreover, fast and slow spindle density have never been assessed in AD/MCI. We have assessed fast and slow spindles in 15 AD patients, 15 amnesic MCI patients, and 15 healthy elderly controls (HC). Participants underwent baseline polysomnographic recording (19 cortical derivations). Spindles during nonrapid eye movements sleep were automatically detected, and spindle densities of the three groups were compared in the derivations where fast and slow spindles exhibited their maximum expression (parietal and frontal, resp.). AD and MCI patients showed a significant parietal fast spindle density decrease, positively correlated with Minimental State Examination scores. Our results suggest that AD-related changes in spindle density are specific for frequency and location, are related to cognitive decline severity, and may have an early onset in the pathology development. PMID:27066274

A low-energy ion source for p-type doping in MBE

International Nuclear Information System (INIS)

Park, R.M.; Stanley, C.R.; Clampitt, R.

1980-01-01

A compact low-energy ion cell has been developed for use as a source of acceptor impurities for the growth of p-type semiconductor material in ultra-high vacuum by molecular beam epitaxy. A flux of either zinc or cadmium atoms is emitted under molecular effusion conditions and partially ionised in the orifice of the cell by electron bombardment. The design provides for control of both the ion energy and current at constant cell temperature. (100)InP has been grown by MBE in a flux of 1 keV Zn ions. The surface morphology and crystal structure show no degradation when compared with (100)InP grown without the Zn ions present. (author)

A study of the Ne 2s2p{sup 5}({sup 3}P)3s and 3p correlation satellites up to 75 eV above threshold

Energy Technology Data Exchange (ETDEWEB)

Yarzhemsky, V G [RAS Kurnakov Institute of General and Inorganic Chemistry, Moscow (Russian Federation); Amusia, M Ya [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel); Bolognesi, P; Avaldi, L, E-mail: lorenzo.avaldi@imip.cnr.i [CNR-Istituto di Metodologie Inorganiche e dei Plasmi, Area della Ricerca di Roma 1, CP 10, 00016 Monterotondo Scalo (Italy)

2010-09-28

The 2s2p{sup 5}({sup 3}P)3s {sup 2}P, 3p {sup 2}D and {sup 2}S satellite states of neon have been studied at several energies from 5 to 75 eV above their respective thresholds. The relative intensities of the satellite states with respect to their main lines shed light on the nature of the many-electron correlations leading to the formation of these satellites. The experimental results are compared with a calculation which makes use of a random phase approximation with exchange (RPAE) cross sections, and takes into account the shake-up and direct knock-out channels as well as their interference.

FIRST DETECTION OF [C I] {sup 3}P{sub 1}–{sup 3}P{sub 0} EMISSION FROM A PROTOPLANETARY DISK

Energy Technology Data Exchange (ETDEWEB)

Tsukagoshi, Takashi; Momose, Munetake [College of Science, Ibaraki University, Bunkyo 2-1-1, Mito 310-8512 (Japan); Saito, Masao [Nobeyama Radio Observatory, Minamimaki, Minamisaku, Nagano 384-1305 (Japan); Kitamura, Yoshimi [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Yoshinodai 3-1-1, Sagamihara, Kanagawa 229-8510 (Japan); Shimajiri, Yoshito [Laboratoire AIM, CEA/DSM-CNRS-Université Paris, Diderot, IRFU/Service d’Astrophysique, CEA, Saclay, F-91191 Gif-sur-Yvette Cedex (France); Kawabe, Ryohei, E-mail: ttsuka@mx.ibaraki.ac.jp [National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588 (Japan)

2015-03-20

We performed single point [C i] {sup 3}P{sub 1}–{sup 3}P{sub 0} and CO J = 4–3 observations toward three T Tauri stars (TTSs), DM Tau, LkCa 15, and TW Hya, using the Atacama Large Millimeter/submillimeter Array Band 8 qualification model receiver installed on the Atacama Submillimeter Telescope Experiment. Two protostars (PSs) in the Taurus L1551 region, L1551 IRS 5 and HL Tau, were also observed. We successfully detected [C i] emission from the protoplanetary disk around DM Tau as well as the protostellar targets. The spectral profile of the [C i] emission from the protoplanetary disk is marginally single-peaked, suggesting that atomic carbon (C) extends toward the outermost disk. The detected [C i] emission is optically thin and the column densities of C are estimated to be ≲10{sup 16} and ∼10{sup 17} cm{sup −2} for the TTS targets and the PSs, respectively. We found a clear difference in the total mass ratio of C to dust, M(C)/M(dust), between the TTSs and protostellar targets; the M(C)/M(dust) ratio of the TTSs is one order of magnitude smaller than that of the PSs. The decrease of the estimated M(C)/M(dust) ratios for the disk sources is consistent with a theoretical prediction that the atomic C can survive only in the near surface layer of the disk and C{sup +}/C/CO transition occurs deeper into the disk midplane.

Activation in the Right Inferior Parietal Lobule Reflects the Representation of Musical Structure beyond Simple Pitch Discrimination

Science.gov (United States)

Royal, Isabelle; Vuvan, Dominique T.; Zendel, Benjamin Rich; Robitaille, Nicolas; Schönwiesner, Marc; Peretz, Isabelle

2016-01-01

Pitch discrimination tasks typically engage the superior temporal gyrus and the right inferior frontal gyrus. It is currently unclear whether these regions are equally involved in the processing of incongruous notes in melodies, which requires the representation of musical structure (tonality) in addition to pitch discrimination. To this aim, 14 participants completed two tasks while undergoing functional magnetic resonance imaging, one in which they had to identify a pitch change in a series of non-melodic repeating tones and a second in which they had to identify an incongruous note in a tonal melody. In both tasks, the deviants activated the right superior temporal gyrus. A contrast between deviants in the melodic task and deviants in the non-melodic task (melodic > non-melodic) revealed additional activity in the right inferior parietal lobule. Activation in the inferior parietal lobule likely represents processes related to the maintenance of tonal pitch structure in working memory during pitch discrimination. PMID:27195523

Mechanisms within the Parietal Cortex Correlate with the Benefits of Random Practice in Motor Adaptation

Directory of Open Access Journals (Sweden)

Benjamin Thürer

2017-08-01

Full Text Available The motor learning literature shows an increased retest or transfer performance after practicing under unstable (random conditions. This random practice effect (also known as contextual interference effect is frequently investigated on the behavioral level and discussed in the context of mechanisms of the dorsolateral prefrontal cortex and increased cognitive efforts during movement planning. However, there is a lack of studies examining the random practice effect in motor adaptation tasks and, in general, the underlying neural processes of the random practice effect are not fully understood. We tested 24 right-handed human subjects performing a reaching task using a robotic manipulandum. Subjects learned to adapt either to a blocked or a random schedule of different force field perturbations while subjects’ electroencephalography (EEG was recorded. The behavioral results showed a distinct random practice effect in terms of a more stabilized retest performance of the random compared to the blocked practicing group. Further analyses showed that this effect correlates with changes in the alpha band power in electrodes over parietal areas. We conclude that the random practice effect in this study is facilitated by mechanisms within the parietal cortex during movement execution which might reflect online feedback mechanisms.

Object integration requires attention: Visual search for Kanizsa figures in parietal extinction.

Science.gov (United States)

Gögler, Nadine; Finke, Kathrin; Keller, Ingo; Müller, Hermann J; Conci, Markus

2016-11-01

The contribution of selective attention to object integration is a topic of debate: integration of parts into coherent wholes, such as in Kanizsa figures, is thought to arise either from pre-attentive, automatic coding processes or from higher-order processes involving selective attention. Previous studies have attempted to examine the role of selective attention in object integration either by employing visual search paradigms or by studying patients with unilateral deficits in selective attention. Here, we combined these two approaches to investigate object integration in visual search in a group of five patients with left-sided parietal extinction. Our search paradigm was designed to assess the effect of left- and right-grouped nontargets on detecting a Kanizsa target square. The results revealed comparable reaction time (RT) performance in patients and controls when they were presented with displays consisting of a single to-be-grouped item that had to be classified as target vs. nontarget. However, when display size increased to two items, patients showed an extinction-specific pattern of enhanced RT costs for nontargets that induced a partial shape grouping on the right, i.e., in the attended hemifield (relative to the ungrouped baseline). Together, these findings demonstrate a competitive advantage for right-grouped objects, which in turn indicates that in parietal extinction, attentional competition between objects particularly limits integration processes in the contralesional, i.e., left hemifield. These findings imply a crucial contribution of selective attentional resources to visual object integration. Copyright © 2016 Elsevier Ltd. All rights reserved.

Model of the biological flow of phosphorus from supplemental phosphates sources in pig diets, using the 32P as marker

International Nuclear Information System (INIS)

Batista Lopes, Jose

1999-01-01

The experiment was designed to test hypotheses, to adjust through simulation bio mathematical models to the phosphorus metabolism and to evaluate the absorption, retention, endogenous P that returns to the digestive tract, dietary absorbed P, accretion, reabsorption and balance of P in bone and tissues and fraction of P from total absorbed and the bone and tissue which returns to the digestive tract, in growing pigs fed different phosphates sources. The model mathematical, deterministic and compartimental was adapted from the studies of FERNANDEZ (1995) and GRACE (1981). The model is represented by three compartiments the digestive tract (C1), bones (C2) and liver heart, kidney and muscle (C3). The information on metabolism and kinetics of the P in tissues obtained by isotopcic dilution technique were used. It was concluded that: the hypotheses established in the model are coherent and the obtained values are adjusted to the P flow in pigs; the variables P intake, endogenous P that return to the digestive tract, P retention, dietary absorbed P, incorporation, reabsorption and balance of P from bone and tissues and fraction of P from total absorved that returned to the digestive tract wasn't influenced by the supplemental P of the phosphates sources; the dietary phosphorus can interfere in the distribution of P in the tissues after the process of absorption of that mineral; the fraction of P from total absorbed P which return to the digestive tract is proportional to P intake

Differential roles of polar orbital prefrontal cortex and parietal lobes in logical reasoning with neutral and negative emotional content.

Science.gov (United States)

Eimontaite, Iveta; Goel, Vinod; Raymont, Vanessa; Krueger, Frank; Schindler, Igor; Grafman, Jordan

2018-05-14

To answer the question of how brain pathology affects reasoning about negative emotional content, we administered a disjunctive logical reasoning task involving arguments with neutral content (e.g. Either there are tigers or women in NYC, but not both; There are no tigers in NYC; There are women in NYC) and emotionally laden content (e.g. Either there are pedophiles or politicians in Texas, but not both; There are politicians in Texas; There are no pedophiles in Texas) to 92 neurological patients with focal lesions to various parts of the brain. A Voxel Lesion Symptom Mapping (VLSM) analysis identified 16 patients, all with lesions to the orbital polar prefrontal cortex (BA 10 & 11), as being selectively impaired in the emotional reasoning condition. Another 17 patients, all with lesions to the parietal cortex, were identified as being impaired in the neutral content condition. The reasoning scores of these two patient groups, along with 23 matched normal controls, underwent additional analysis to explore the effect of belief bias. This analysis revealed that the differences identified above were largely driven by trials where there was an incongruency between the believability of the conclusion and the validity of the argument (i.e. valid argument /false conclusion or invalid argument /true conclusion). Patients with lesions to polar orbital prefrontal cortex underperformed in incongruent emotional content trials and over performed in incongruent neutral content trials (compared to both normal controls and patients with parietal lobe lesions). Patients with lesions to parietal lobes underperformed normal controls (at a trend level) in neutral trials where there was a congruency between the believability of the conclusion and the validity of the argument (i.e. valid argument/true conclusion or invalid argument/false conclusion). We conclude that lesions to the polar orbital prefrontal cortex (i) prevent these patients from enjoying any emotionally induced cognitive

Effect of transcranial magnetic stimulation (TMS on parietal and premotor cortex during planning of reaching movements.

Directory of Open Access Journals (Sweden)

Pierpaolo Busan

Full Text Available BACKGROUND: Cerebral activation during planning of reaching movements occurs both in the superior parietal lobule (SPL and premotor cortex (PM, and their activation seems to take place in parallel. METHODOLOGY: The activation of the SPL and PM has been investigated using transcranial magnetic stimulation (TMS during planning of reaching movements under visual guidance. PRINCIPAL FINDINGS: A facilitory effect was found when TMS was delivered on the parietal cortex at about half of the time from sight of the target to hand movement, independently of target location in space. Furthermore, at the same stimulation time, a similar facilitory effect was found in PM, which is probably related to movement preparation. CONCLUSIONS: This data contributes to the understanding of cortical dynamics in the parieto-frontal network, and suggests that it is possible to interfere with the planning of reaching movements at different cortical points within a particular time window. Since similar effects may be produced at similar times on both the SPL and PM, parallel processing of visuomotor information is likely to take place in these regions.

Excitation into 3p55p levels from the metastable levels of Ar

International Nuclear Information System (INIS)

Jung, R. O.; Boffard, John B.; Anderson, L. W.; Lin, Chun C.

2007-01-01

Measurements of cross sections for electron-impact excitation out of the J=0 and J=2 3p 5 4s metastable levels of argon into nine of the ten levels of the 3p 5 5p manifold are presented in the energy range from threshold to 10 eV. A mixed target of atoms in both metastable levels was created by a hollow cathode discharge. Laser quenching was used to depopulate either one of the metastable levels, allowing separate measurements of the cross sections from each of the two metastable levels. Unlike the metastable excitation cross sections into 3p 5 4p levels, the cross sections into the 3p 5 5p levels are not found to be proportional to optical oscillator strengths

Effect of the green/blue flicker matrix for P300-based brain–computer interface: an EEG–fMRI study.

Directory of Open Access Journals (Sweden)

Shiro eIkegami

2012-07-01

Full Text Available The visual P300 brain–computer interface (BCI, a popular system for EEG-based BCI, utilizes the P300 event-related potential to select an icon arranged in a flicker matrix. In the conventional P300 BCI speller paradigm, white/gray luminance intensification of each row/column in the matrix is used. In an earlier study, we applied green/blue luminance and chromatic change in the P300 BCI system and reported that this luminance and chromatic flicker matrix was associated with better performance and greater subject comfort compared with the conventional white/gray luminance flicker matrix. In this study, we used simultaneous EEG-fMRI recordings to identify brain areas that were more enhanced in the green/blue flicker matrix than in the white/gray flicker matrix, as these may highlight areas devoted to improved P300-BCI performance. The peak of the positive wave in the EEG data was detected under both conditions, and the peak amplitudes were larger at the parietal and occipital electrodes, particularly in the late components, under the green/blue condition than under the white/gray condition. fMRI data showed activation in the bilateral parietal and occipital cortices, and these areas, particularly those in the right hemisphere, were more activated under the green/blue condition than under the white/gray condition. The parietal and occipital regions more involved in the green/blue condition were part of the areas devoted to conventional P300s. These results suggest that the green/blue flicker matrix was useful for enhancing the so-called P300 responses.

Diagnosis of pulmonary artery embolism. Comparison of single-source CT and 3rd generation dual-source CT using a dual-energy protocol regarding image quality and radiation dose

International Nuclear Information System (INIS)

Petritsch, Bernhard; Kosmala, Aleksander; Gassenmeier, Tobias; Weng, Andreas Max; Veldhoen, Simon; Kunz, Andreas Steven; Bley, Thorsten Alexander

2017-01-01

To compare radiation dose, subjective and objective image quality of 3 rd generation dual-source CT (DSCT) and dual-energy CT (DECT) with conventional 64-slice single-source CT (SSCT) for pulmonary CTA. 180 pulmonary CTA studies were performed in three patient cohorts of 60 patients each. Group 1: conventional SSCT 120 kV (ref.); group 2: single-energy DSCT 100 kV (ref.); group 3: DECT 90/Sn150 kV. CTDIvol, DLP, effective radiation dose were reported, and CT attenuation (HU) was measured on three central and peripheral levels. The signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR) were calculated. Two readers assessed subjective image quality according to a five-point scale. Mean CTDIvol and DLP were significantly lower in the dual-energy group compared to the SSCT group (p < 0.001 [CTDIvol]; p < 0.001 [DLP]) and the DSCT group (p = 0.003 [CTDIvol]; p = 0.003 [DLP]), respectively. The effective dose in the DECT group was 2.79 ± 0.95 mSv and significantly smaller than in the SSCT group (4.60 ± 1.68 mSv, p < 0.001) and the DSCT group (4.24 ± 2.69 mSv, p = 0.003). The SNR and CNR were significantly higher in the DSCT group (p < 0.001). Subjective image quality did not differ significantly among the three protocols and was rated good to excellent in 75 % (135/180) of cases with an inter-observer agreement of 80 %. Dual-energy pulmonary CTA protocols of 3 rd generation dual-source scanners allow for significant reduction of radiation dose while providing excellent image quality and potential additional information by means of perfusion maps. Dual-energy CT with 90/Sn150 kV configuration allows for significant dose reduction in pulmonary CTA. Subjective image quality was similar among the three evaluated CT-protocols (64-slice SSCT, single-energy DSCT, 90/Sn150 kV DECT) and was rated good to excellent in 75% of cases. Dual-energy CT provides potential additional information by means of iodine distribution maps.

3D Multi‐source Least‐squares Reverse Time Migration

KAUST Repository

Dai, Wei; Boonyasiriwat, Chaiwoot; Schuster, Gerard T.

2010-01-01

: random time shift, random source polarity and random source location selected from a pre‐designed table. Numerical tests for the 3D SEG/EAGE Overthrust model show that multi‐source LSRTM can suppress migration artifacts in the migration image and remove

Dual-Source Linear Energy Prediction (LINE-P) Model in the Context of WSNs.

Science.gov (United States)

Ahmed, Faisal; Tamberg, Gert; Le Moullec, Yannick; Annus, Paul

2017-07-20

Energy harvesting technologies such as miniature power solar panels and micro wind turbines are increasingly used to help power wireless sensor network nodes. However, a major drawback of energy harvesting is its varying and intermittent characteristic, which can negatively affect the quality of service. This calls for careful design and operation of the nodes, possibly by means of, e.g., dynamic duty cycling and/or dynamic frequency and voltage scaling. In this context, various energy prediction models have been proposed in the literature; however, they are typically compute-intensive or only suitable for a single type of energy source. In this paper, we propose Linear Energy Prediction "LINE-P", a lightweight, yet relatively accurate model based on approximation and sampling theory; LINE-P is suitable for dual-source energy harvesting. Simulations and comparisons against existing similar models have been conducted with low and medium resolutions (i.e., 60 and 22 min intervals/24 h) for the solar energy source (low variations) and with high resolutions (15 min intervals/24 h) for the wind energy source. The results show that the accuracy of the solar-based and wind-based predictions is up to approximately 98% and 96%, respectively, while requiring a lower complexity and memory than the other models. For the cases where LINE-P's accuracy is lower than that of other approaches, it still has the advantage of lower computing requirements, making it more suitable for embedded implementation, e.g., in wireless sensor network coordinator nodes or gateways.

Association of miR-548c-5p, miR-7-5p, miR-210-3p, miR-128-3p with recurrence in systemically untreated breast cancer

DEFF Research Database (Denmark)

Block, Ines; Burton, Mark; Sørensen, Kristina Pilekær

2018-01-01

. To validate their prognostic potential, we analyzed microRNA expression in an independent cohort (n = 110) using a pairmatched study design minimizing dependence of classical markers. The expression of hsa-miR-548c-5p was significantly associated with abridged disease-free survival (hazard ratio [HR]:1.96, p...... = 0.027). Contradicting published results, high hsa-miR516-3p expression was associated with favorable outcome (HR:0.29, p = 0.0068). The association is probably time-dependent indicating later relapse. Additionally, re-analysis of previously published expression data of two matching cohorts (n = 100......, n = 255) supports an association of hsa-miR-128-3p with shortened diseasefree survival (HR:2.48, p = 0.0033) and an upregulation of miR-7-5p (p = 0.0038; p = 0.039) and miR-210-3p (p = 0.031) in primary tumors of patients who experienced metastases. Further analysis may verify the prognostic...

Facile consecutive solvothermal growth of highly fluorescent InP/ZnS core/shell quantum dots using a safer phosphorus source.

Science.gov (United States)

Byun, Ho-June; Song, Woo-Seuk; Yang, Heesun

2011-06-10

The work presents a facile, stepwise synthetic approach for the production of highly fluorescent InP/ZnS core/shell quantum dots (QDs) by using a safer phosphorus (P) precursor. First, InP quantum dots (QDs) were solvothermally prepared at 180 °C for 24 h by using a P source of P(N(CH(3))(2))(3). The as-grown InP QDs were consecutively placed in another solvothermal condition for ZnS shell overcoating. In contrast to the almost non-fluorescent InP QDs, due to their highly defective surface states, the ZnS-coated InP QDs were highly fluorescent as a result of effective surface passivation. After the shell growth, the resulting InP/ZnS core/shell QDs were subjected to a size-sorting processing, by which red- to green-emitting QDs with quantum yields (QYs) of 24-60% were produced. Solvothermal shell growth parameters such as the reaction time and Zn/In solution concentration ratio were varied and optimized toward the highest QYs of core/shell QDs.

Facile consecutive solvothermal growth of highly fluorescent InP/ZnS core/shell quantum dots using a safer phosphorus source

International Nuclear Information System (INIS)

Byun, Ho-June; Song, Woo-Seuk; Yang, Heesun

2011-01-01

The work presents a facile, stepwise synthetic approach for the production of highly fluorescent InP/ZnS core/shell quantum dots (QDs) by using a safer phosphorus (P) precursor. First, InP quantum dots (QDs) were solvothermally prepared at 180 deg. C for 24 h by using a P source of P(N(CH 3 ) 2 ) 3 . The as-grown InP QDs were consecutively placed in another solvothermal condition for ZnS shell overcoating. In contrast to the almost non-fluorescent InP QDs, due to their highly defective surface states, the ZnS-coated InP QDs were highly fluorescent as a result of effective surface passivation. After the shell growth, the resulting InP/ZnS core/shell QDs were subjected to a size-sorting processing, by which red- to green-emitting QDs with quantum yields (QYs) of 24-60% were produced. Solvothermal shell growth parameters such as the reaction time and Zn/In solution concentration ratio were varied and optimized toward the highest QYs of core/shell QDs.

Facile consecutive solvothermal growth of highly fluorescent InP/ZnS core/shell quantum dots using a safer phosphorus source

Science.gov (United States)

Byun, Ho-June; Song, Woo-Seuk; Yang, Heesun

2011-06-01

The work presents a facile, stepwise synthetic approach for the production of highly fluorescent InP/ZnS core/shell quantum dots (QDs) by using a safer phosphorus (P) precursor. First, InP quantum dots (QDs) were solvothermally prepared at 180 °C for 24 h by using a P source of P(N(CH3)2)3. The as-grown InP QDs were consecutively placed in another solvothermal condition for ZnS shell overcoating. In contrast to the almost non-fluorescent InP QDs, due to their highly defective surface states, the ZnS-coated InP QDs were highly fluorescent as a result of effective surface passivation. After the shell growth, the resulting InP/ZnS core/shell QDs were subjected to a size-sorting processing, by which red- to green-emitting QDs with quantum yields (QYs) of 24-60% were produced. Solvothermal shell growth parameters such as the reaction time and Zn/In solution concentration ratio were varied and optimized toward the highest QYs of core/shell QDs.

Facile consecutive solvothermal growth of highly fluorescent InP/ZnS core/shell quantum dots using a safer phosphorus source

Energy Technology Data Exchange (ETDEWEB)

Byun, Ho-June; Song, Woo-Seuk; Yang, Heesun, E-mail: hyang@hongik.ac.kr [Department of Materials Science and Engineering, Hongik University, Seoul 121-791 (Korea, Republic of)

2011-06-10

The work presents a facile, stepwise synthetic approach for the production of highly fluorescent InP/ZnS core/shell quantum dots (QDs) by using a safer phosphorus (P) precursor. First, InP quantum dots (QDs) were solvothermally prepared at 180 deg. C for 24 h by using a P source of P(N(CH{sub 3}){sub 2}){sub 3}. The as-grown InP QDs were consecutively placed in another solvothermal condition for ZnS shell overcoating. In contrast to the almost non-fluorescent InP QDs, due to their highly defective surface states, the ZnS-coated InP QDs were highly fluorescent as a result of effective surface passivation. After the shell growth, the resulting InP/ZnS core/shell QDs were subjected to a size-sorting processing, by which red- to green-emitting QDs with quantum yields (QYs) of 24-60% were produced. Solvothermal shell growth parameters such as the reaction time and Zn/In solution concentration ratio were varied and optimized toward the highest QYs of core/shell QDs.

Teaching Petri Nets Using P3

Science.gov (United States)

Gasevic, Dragan; Devedzic, Vladan

2004-01-01

This paper presents Petri net software tool P3 that is developed for training purposes of the Architecture and organization of computers (AOC) course. The P3 has the following features: graphical modeling interface, interactive simulation by single and parallel (with previous conflict resolution) transition firing, two well-known Petri net…

Crystal structure and magnetic properties of the Ba3TeCo3P2O14, Pb3TeCo3P2O14, and Pb3TeCo3V2O14 langasites

DEFF Research Database (Denmark)

Krizan, J.W.; de la Cruz, C.; Andersen, Niels Hessel