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Sample records for matter wm integrity

  1. Numerical simulation of structure integrated cold storages with the model CST-WM; Numerische Simulation gebaeudeintegrierter Kaeltespeicher mit dem Modell CST-WM

    Energy Technology Data Exchange (ETDEWEB)

    Koppatz, Stefan; Urbaneck, Thorsten; Platzer, Bernd [TU Chemnitz (Germany). Fakultaet Maschinenbau; Kalz, Doreen; Sonntag, Martin [Fraunhofer ISE, Freiburg (Germany). Bereich Energieeffiziente und Solare Kuehlung

    2013-04-15

    Decentralized, structure integrated cold water storaged have been purpose of research in Germany for a short time, which is why appropriate system simulation models for mapping their thermal performance are missing. Intention of this article is the presentation of the MATLAB CST-WM model, which is adapted to the special requirements of this storage type in order to differ from existent models. Thereby, a specific method reduces the programming and computation effort.

  2. Poorer frontolimbic white matter integrity is associated with chronic cannabis use, FAAH genotype, and increased depressive and apathy symptoms in adolescents and young adults

    Directory of Open Access Journals (Sweden)

    Skyler G. Shollenbarger

    2015-01-01

    Conclusions: Consistent with prior findings, cannabis use was associated with reduced frontolimbic WM integrity. WM integrity was also moderated by FAAH genotype, in that cannabis-using FAAH C/C carriers and A carrying controls had reduced WM integrity compared to control C/C carriers. Observed frontolimbic white matter abnormalities were linked with increased depressive and apathy symptoms in the cannabis users.

  3. Central Artery Stiffness, Baroreflex Sensitivity, and Brain White Matter Neuronal Fiber Integrity in Older Adults

    OpenAIRE

    Tarumi, Takashi; de Jong, Daan L.K.; Zhu, David C.; Tseng, Benjamin Y.; Liu, Jie; Hill, Candace; Riley, Jonathan; Womack, Kyle B.; Kerwin, Diana R.; Lu, Hanzhang; Cullum, C. Munro; Zhang, Rong

    2015-01-01

    Cerebral hypoperfusion elevates the risk of brain white matter (WM) lesions and cognitive impairment. Central artery stiffness impairs baroreflex, which controls systemic arterial perfusion, and may deteriorate neuronal fiber integrity of brain WM. The purpose of this study was to examine the associations among brain WM neuronal fiber integrity, baroreflex sensitivity (BRS), and central artery stiffness in older adults. Fifty-four adults (65±6 years) with normal cognitive function or mild cog...

  4. Altered Gray Matter Volume and White Matter Integrity in College Students with Mobile Phone Dependence

    OpenAIRE

    Wang, Yongming; Zou, Zhiling; Song, Hongwen; Xu, Xiaodan; Wang, Huijun; d?Oleire Uquillas, Federico; Huang, Xiting

    2016-01-01

    Mobile phone dependence (MPD) is a behavioral addiction that has become an increasing public mental health issue. While previous research has explored some of the factors that may predict MPD, the underlying neural mechanisms of MPD have not been investigated yet. The current study aimed to explore the microstructural variations associated with MPD as measured with functional Magnetic Resonance Imaging (fMRI). Gray matter volume (GMV) and white matter (WM) integrity [four indices: fractional ...

  5. Cognitive Intraindividual Variability and White Matter Integrity in Aging

    Directory of Open Access Journals (Sweden)

    Nathalie Mella

    2013-01-01

    Full Text Available The intraindividual variability (IIV of cognitive performance has been shown to increase with aging. While brain research has generally focused on mean performance, little is known about neural correlates of cognitive IIV. Nevertheless, some studies suggest that IIV relates more strongly than mean level of performance to the quality of white matter (WM. Our study aims to explore the relation between WM integrity and cognitive IIV by combining functional (fMRI and structural (diffusion tensor imaging, DTI imaging. Twelve young adults (aged 18–30 years and thirteen older adults (61–82 years underwent a battery of neuropsychological tasks, along with fMRI and DTI imaging. Their behavioral data were analyzed and correlated with the imaging data at WM regions of interest defined on the basis of (1 the fMRI-activated areas and (2 the Johns Hopkins University (JHU WM tractography atlas. For both methods, fractional anisotropy, along with the mean, radial, and axial diffusivity parameters, was computed. In accord with previous studies, our results showed that the DTI parameters were more related to IIV than to mean performance. Results also indicated that age differences in the DTI parameters were more pronounced in the regions activated primarily by young adults during a choice reaction-time task than in those also activated in older adults.

  6. Integrated coherent matter wave circuits

    International Nuclear Information System (INIS)

    Ryu, C.; Boshier, M. G.

    2015-01-01

    An integrated coherent matter wave circuit is a single device, analogous to an integrated optical circuit, in which coherent de Broglie waves are created and then launched into waveguides where they can be switched, divided, recombined, and detected as they propagate. Applications of such circuits include guided atom interferometers, atomtronic circuits, and precisely controlled delivery of atoms. We report experiments demonstrating integrated circuits for guided coherent matter waves. The circuit elements are created with the painted potential technique, a form of time-averaged optical dipole potential in which a rapidly moving, tightly focused laser beam exerts forces on atoms through their electric polarizability. Moreover, the source of coherent matter waves is a Bose-Einstein condensate (BEC). Finally, we launch BECs into painted waveguides that guide them around bends and form switches, phase coherent beamsplitters, and closed circuits. These are the basic elements that are needed to engineer arbitrarily complex matter wave circuitry

  7. Retroviral integration: Site matters

    Science.gov (United States)

    Demeulemeester, Jonas; De Rijck, Jan

    2015-01-01

    Here, we review genomic target site selection during retroviral integration as a multistep process in which specific biases are introduced at each level. The first asymmetries are introduced when the virus takes a specific route into the nucleus. Next, by co‐opting distinct host cofactors, the integration machinery is guided to particular chromatin contexts. As the viral integrase captures a local target nucleosome, specific contacts introduce fine‐grained biases in the integration site distribution. In vivo, the established population of proviruses is subject to both positive and negative selection, thereby continuously reshaping the integration site distribution. By affecting stochastic proviral expression as well as the mutagenic potential of the virus, integration site choice may be an inherent part of the evolutionary strategies used by different retroviruses to maximise reproductive success. PMID:26293289

  8. Central Artery Stiffness, Baroreflex Sensitivity, and Brain White Matter Neuronal Fiber Integrity in Older Adults

    Science.gov (United States)

    Tarumi, Takashi; de Jong, Daan L.K.; Zhu, David C.; Tseng, Benjamin Y.; Liu, Jie; Hill, Candace; Riley, Jonathan; Womack, Kyle B.; Kerwin, Diana R.; Lu, Hanzhang; Cullum, C. Munro; Zhang, Rong

    2015-01-01

    Cerebral hypoperfusion elevates the risk of brain white matter (WM) lesions and cognitive impairment. Central artery stiffness impairs baroreflex, which controls systemic arterial perfusion, and may deteriorate neuronal fiber integrity of brain WM. The purpose of this study was to examine the associations among brain WM neuronal fiber integrity, baroreflex sensitivity (BRS), and central artery stiffness in older adults. Fifty-four adults (65±6 years) with normal cognitive function or mild cognitive impairment (MCI) were tested. The neuronal fiber integrity of brain WM was assessed from diffusion metrics acquired by diffusion tensor imaging. BRS was measured in response to acute changes in blood pressure induced by bolus injections of vasoactive drugs. Central artery stiffness was measured by carotid-femoral pulse wave velocity (cfPWV). The WM diffusion metrics including fractional anisotropy (FA) and radial (RD) and axial (AD) diffusivities, BRS, and cfPWV were not different between the control and MCI groups. Thus, the data from both groups were combined for subsequent analyses. Across WM, fiber tracts with decreased FA and increased RD were associated with lower BRS and higher cfPWV, with many of the areas presenting spatial overlap. In particular, the BRS assessed during hypotension was strongly correlated with FA and RD when compared with hypertension. Executive function performance was associated with FA and RD in the areas that correlated with cfPWV and BRS. These findings suggest that baroreflex-mediated control of systemic arterial perfusion, especially during hypotension, may play a crucial role in maintaining neuronal fiber integrity of brain WM in older adults. PMID:25623500

  9. Lifelong bilingualism contributes to cognitive reserve against white matter integrity declines in aging.

    Science.gov (United States)

    Gold, Brian T; Johnson, Nathan F; Powell, David K

    2013-11-01

    Recent evidence suggests that lifelong bilingualism may contribute to cognitive reserve (CR) in normal aging. However, there is currently no neuroimaging evidence to suggest that lifelong bilinguals can retain normal cognitive functioning in the face of age-related neurodegeneration. Here we explored this issue by comparing white matter (WM) integrity and gray matter (GM) volumetric patterns of older adult lifelong bilinguals (N=20) and monolinguals (N=20). The groups were matched on a range of relevant cognitive test scores and on the established CR variables of education, socioeconomic status and intelligence. Participants underwent high-resolution structural imaging for assessment of GM volume and diffusion tensor imaging (DTI) for assessment of WM integrity. Results indicated significantly lower microstructural integrity in the bilingual group in several WM tracts. In particular, compared to their monolingual peers, the bilingual group showed lower fractional anisotropy and/or higher radial diffusivity in the inferior longitudinal fasciculus/inferior fronto-occipital fasciculus bilaterally, the fornix, and multiple portions of the corpus callosum. There were no group differences in GM volume. Our results suggest that lifelong bilingualism contributes to CR against WM integrity declines in aging. © 2013 Published by Elsevier Ltd.

  10. Altered Gray Matter Volume and White Matter Integrity in College Students with Mobile Phone Dependence.

    Science.gov (United States)

    Wang, Yongming; Zou, Zhiling; Song, Hongwen; Xu, Xiaodan; Wang, Huijun; d'Oleire Uquillas, Federico; Huang, Xiting

    2016-01-01

    Mobile phone dependence (MPD) is a behavioral addiction that has become an increasing public mental health issue. While previous research has explored some of the factors that may predict MPD, the underlying neural mechanisms of MPD have not been investigated yet. The current study aimed to explore the microstructural variations associated with MPD as measured with functional Magnetic Resonance Imaging (fMRI). Gray matter volume (GMV) and white matter (WM) integrity [four indices: fractional anisotropy (FA); mean diffusivity (MD); axial diffusivity (AD); and radial diffusivity (RD)] were calculated via voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) analysis, respectively. Sixty-eight college students (42 female) were enrolled and separated into two groups [MPD group, N = 34; control group (CG), N = 34] based on Mobile Phone Addiction Index (MPAI) scale score. Trait impulsivity was also measured using the Barratt Impulsiveness Scale (BIS-11). In light of underlying trait impulsivity, results revealed decreased GMV in the MPD group relative to controls in regions such as the right superior frontal gyrus (sFG), right inferior frontal gyrus (iFG), and bilateral thalamus (Thal). In the MPD group, GMV in the above mentioned regions was negatively correlated with scores on the MPAI. Results also showed significantly less FA and AD measures of WM integrity in the MPD group relative to controls in bilateral hippocampal cingulum bundle fibers (CgH). Additionally, in the MPD group, FA of the CgH was also negatively correlated with scores on the MPAI. These findings provide the first morphological evidence of altered brain structure with mobile phone overuse, and may help to better understand the neural mechanisms of MPD in relation to other behavioral and substance addiction disorders.

  11. Altered Gray Matter Volume and White Matter Integrity in College Students with Mobile Phone Dependence

    Science.gov (United States)

    Wang, Yongming; Zou, Zhiling; Song, Hongwen; Xu, Xiaodan; Wang, Huijun; d’Oleire Uquillas, Federico; Huang, Xiting

    2016-01-01

    Mobile phone dependence (MPD) is a behavioral addiction that has become an increasing public mental health issue. While previous research has explored some of the factors that may predict MPD, the underlying neural mechanisms of MPD have not been investigated yet. The current study aimed to explore the microstructural variations associated with MPD as measured with functional Magnetic Resonance Imaging (fMRI). Gray matter volume (GMV) and white matter (WM) integrity [four indices: fractional anisotropy (FA); mean diffusivity (MD); axial diffusivity (AD); and radial diffusivity (RD)] were calculated via voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) analysis, respectively. Sixty-eight college students (42 female) were enrolled and separated into two groups [MPD group, N = 34; control group (CG), N = 34] based on Mobile Phone Addiction Index (MPAI) scale score. Trait impulsivity was also measured using the Barratt Impulsiveness Scale (BIS-11). In light of underlying trait impulsivity, results revealed decreased GMV in the MPD group relative to controls in regions such as the right superior frontal gyrus (sFG), right inferior frontal gyrus (iFG), and bilateral thalamus (Thal). In the MPD group, GMV in the above mentioned regions was negatively correlated with scores on the MPAI. Results also showed significantly less FA and AD measures of WM integrity in the MPD group relative to controls in bilateral hippocampal cingulum bundle fibers (CgH). Additionally, in the MPD group, FA of the CgH was also negatively correlated with scores on the MPAI. These findings provide the first morphological evidence of altered brain structure with mobile phone overuse, and may help to better understand the neural mechanisms of MPD in relation to other behavioral and substance addiction disorders. PMID:27199831

  12. Altered gray matter volume and white matter integrity in college students with mobile phone dependence

    Directory of Open Access Journals (Sweden)

    Yongming eWang

    2016-05-01

    Full Text Available Mobile phone dependence (MPD is a behavioral addiction that has become an increasing public mental health issue. While previous research has explored some of the factors that may predict MPD, the underlying neural mechanisms of MPD have not been investigated yet. The current study aimed to explore the microstructural variations associated with MPD as measured with functional Magnetic Resonance Imaging (fMRI. Gray matter volume (GMV and white matter (WM integrity (four indexes: fractional anisotropy, FA; mean diffusivity, MD; axial diffusivity, AD; and radial diffusivity, RD were calculated via voxel-based morphometry (VBM and tract-based spatial statistics (TBSS analysis, respectively. Sixty-eight college students (42 female were enrolled and separated into two groups (MPD group, N=34; control group, N=34 based on Mobile Phone Addiction Index (MPAI scale score. Trait impulsivity was also measured using the Barrett Impulsivity Scale (BIS-11. In light of underlying trait impulsivity, results revealed decreased GMV in the MPD group relative to controls in regions such as the right superior frontal gyrus (sFG, right inferior frontal gyrus (iFG, and bilateral thalamus (Thal. In the MPD group, GMV in the above mentioned regions was negatively correlated with scores on the MPAI. Results also showed significantly less FA and AD measures of white matter integrity in the MPD group relative to controls in bilateral hippocampal cingulum bundle fibers (CgH. Additionally, in the MPD group, FA of the CgH was also negatively correlated with scores on the MPAI. These findings provide the first morphological evidence of altered brain structure with phone-overuse, and may help to better understand the neural mechanisms of MPD in relation with other behavioral and substance addiction disorders.

  13. White matter microstructure in 22q11 deletion syndrome: a pilot diffusion tensor imaging and voxel-based morphometry study of children and adolescents

    NARCIS (Netherlands)

    Sundram, Frederick; Campbell, Linda E.; Azuma, Rayna; Daly, Eileen; Bloemen, Oswald J. N.; Barker, Gareth J.; Chitnis, Xavier; Jones, Derek K.; van Amelsvoort, Therese; Murphy, Kieran C.; Murphy, Declan G. M.

    2010-01-01

    Young people with 22q11 Deletion Syndrome (22q11DS) are at substantial risk for developing psychosis and have significant differences in white matter (WM) volume. However, there are few in vivo studies of both WM microstructural integrity (as measured using Diffusion Tensor (DT)-MRI) and WM volume

  14. Spaceflight Effect on White Matter Structural Integrity

    Science.gov (United States)

    Lee, Jessica K.; Kopplemans, Vincent; Paternack, Ofer; Bloomberg, Jacob J.; Mulavara, Ajitkumar P.; Seidler, Rachael D.

    2017-01-01

    Recent reports of elevated brain white matter hyperintensity (WMH) counts and volume in postflight astronaut MRIs suggest that further examination of spaceflight's impact on the microstructure of brain white matter is warranted. To this end, retrospective longitudinal diffusion-weighted MRI scans obtained from 15 astronauts were evaluated. In light of the recent reports of microgravity-induced cephalad fluid shift and gray matter atrophy seen in astronauts, we applied a technique to estimate diffusion tensor imaging (DTI) metrics corrected for free water contamination. This approach enabled the analysis of white matter tissue-specific alterations that are unrelated to fluid shifts, occurring from before spaceflight to after landing. After spaceflight, decreased fractional anisotropy (FA) values were detected in an area encompassing the superior and inferior longitudinal fasciculi and the inferior fronto-occipital fasciculus. Increased radial diffusivity (RD) and decreased axial diffusivity (AD) were also detected within overlapping regions. In addition, FA values in the corticospinal tract decreased and RD measures in the precentral gyrus white matter increased from before to after flight. The results show disrupted structural connectivity of white matter in tracts involved in visuospatial processing, vestibular function, and movement control as a result of spaceflight. The findings may help us understand the structural underpinnings of the extensive spaceflight-induced sensorimotor remodeling. Prospective longitudinal assessment of the white matter integrity in astronauts is needed to characterize the evolution of white matter microstructural changes associated with spaceflight, their behavioral consequences, and the time course of recovery. Supported by a grant from the National Space Biomedical Research Institute, NASA NCC 9-58.

  15. Association between abnormal serum myelin-specific protein levels and white matter integrity in first-episode and drug-naïve patients with major depressive disorder.

    Science.gov (United States)

    Jiang, Linling; Cheng, Yuqi; Jiang, Hongyan; Xu, Jian; Lu, Jin; Shen, Zonglin; Lu, Yi; Liu, Fang; Li, Luqiong; Xu, Xiufeng

    2018-05-01

    Although the structural abnormalities of white matter (WM) have been described in patients with major depressive disorder (MDD), the neuropathological changes remain unclear. The current study aimed to investigate the myelin oligodendrocyte glycoprotein (MOG) and myelin-associated glycoprotein (MAG) levels and their correlations with WM integrity in first-episode, drug-naïve MDD patients. We obtained diffusion tensor images of 102 first-episode, drug-naïve MDD patients and 81 age- and sex-matched controls. Serum MOG and MAG levels of all participants were measured and compared between the two groups. The correlations between WM integrity and MOG and MAG levels were examined. MOG and MAG serum levels were significantly higher in MDD patients than in controls. Patients with MDD also showed decreased fractional anisotropy (FA) and axial diffusivity in the WM of the bilateral thalamus, right hippocampus, right temporal lobe, and left pulvinar. At the whole-brain level, no regions showed any correlations of diffusivity parameters with MOG or MAG levels in healthy subjects. However, we observed two-way correlations between the MOG and MAG levels and the FA and mean diffusivity values in the WM of the left middle frontal lobe, right inferior parietal lobe, and right supplementary motor area in MDD patients. Further investigation with a larger sample size and longitudinal studies are required to better understand the neuropathology of WM integrity in MDD. Our findings represent the first evidence of a relationship between abnormal serum myelin-specific protein levels and impaired WM integrity, which may help to better understand the neurobiological mechanisms of MDD. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Surface-based vertexwise analysis of morphometry and microstructural integrity for white matter tracts in diffusion tensor imaging: With application to the corpus callosum in Alzheimer's disease.

    Science.gov (United States)

    Tang, Xiaoying; Qin, Yuanyuan; Zhu, Wenzhen; Miller, Michael I

    2017-04-01

    In this article, we present a unified statistical pipeline for analyzing the white matter (WM) tracts morphometry and microstructural integrity, both globally and locally within the same WM tract, from diffusion tensor imaging. Morphometry is quantified globally by the volumetric measurement and locally by the vertexwise surface areas. Meanwhile, microstructural integrity is quantified globally by the mean fractional anisotropy (FA) and trace values within the specific WM tract and locally by the FA and trace values defined at each vertex of its bounding surface. The proposed pipeline consists of four steps: (1) fully automated segmentation of WM tracts in a multi-contrast multi-atlas framework; (2) generation of the smooth surface representations for the WM tracts of interest; (3) common template surface generation on which the localized morphometric and microstructural statistics are defined and a variety of statistical analyses can be conducted; (4) multiple comparison correction to determine the significance of the statistical analysis results. Detailed herein, this pipeline has been applied to the corpus callosum in Alzheimer's disease (AD) with significantly decreased FA values and increased trace values, both globally and locally, being detected in patients with AD when compared to normal aging populations. A subdivision of the corpus callosum in both hemispheres revealed that the AD pathology primarily affects the body and splenium of the corpus callosum. Validation analyses and two multiple comparison correction strategies are provided. Hum Brain Mapp 38:1875-1893, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  17. Reduced white matter integrity and facial emotion perception in never-medicated patients with first-episode schizophrenia: A diffusion tensor imaging study.

    Science.gov (United States)

    Zhao, Xiaoxin; Sui, Yuxiu; Yao, Jingjing; Lv, Yiding; Zhang, Xinyue; Jin, Zhuma; Chen, Lijun; Zhang, Xiangrong

    2017-07-03

    Facial emotion perception is impaired in schizophrenia. Although the pathology of schizophrenia is thought to involve abnormality in white matter (WM), few studies have examined the correlation between facial emotion perception and WM abnormalities in never-medicated patients with first-episode schizophrenia. The present study tested associations between facial emotion perception and WM integrity in order to investigate the neural basis of impaired facial emotion perception in schizophrenia. Sixty-three schizophrenic patients and thirty control subjects underwent facial emotion categorization (FEC). The FEC data was inserted into a logistic function model with subsequent analysis by independent-samples T test and the shift point and slope as outcome measurements. Severity of symptoms was measured using a five-factor model of the Positive and Negative Syndrome Scale (PANSS). Voxelwise group comparison of WM fractional anisotropy (FA) was operated using tract-based spatial statistics (TBSS). The correlation between impaired facial emotion perception and FA reduction was examined in patients using simple regression analysis within brain areas that showed a significant FA reduction in patients compared with controls. The same correlation analysis was also performed for control subjects in the whole brain. The patients with schizophrenia reported a higher shift point and a steeper slope than control subjects in FEC. The patients showed a significant FA reduction in left deep WM in the parietal, temporal and occipital lobes, a small portion of the corpus callosum (CC), and the corona radiata. In voxelwise correlation analysis, we found that facial emotion perception significantly correlated with reduced FA in various WM regions, including left forceps major (FM), inferior longitudinal fasciculus (ILF), inferior fronto-occipital fasciculus (IFOF), Left splenium of CC, and left ILF. The correlation analyses in healthy controls revealed no significant correlation of FA with

  18. Topological matter, integrable models and fusion rings

    International Nuclear Information System (INIS)

    Nemeschansky, D.; Warner, N.P.

    1992-01-01

    We show how topological G k /G k models can be embedded into the topological matter models that are obtained by perturbing the twisted N = 2 supersymmetric, hermitian symmetric, coset models. In particular, this leads to an embedding of the fusion ring of G as a sub-ring of the perturbed, chiral primary ring. The perturbation of the twisted N = 2 model that leads to the fusion ring is also shown to lead to an integrable N = 2 supersymmetric field theory when the untwisted N = 2 superconformal field theory is perturbed by the same operator and its hermitian conjugate. (orig.)

  19. Tank Farm WM-182 and WM-183 Heel Slurry Samples PSD Results

    International Nuclear Information System (INIS)

    Batcheller, T.A.; Huestis, G.M.

    2000-01-01

    Particle size distribution (PSD) analysis of INTEC Tank Farm WM-182 and WM-183 heel slurry samples were performed using a modified Horiba LA-300 PSD analyzer at the RAL facility. There were two types of testing performed: typical PSD analysis, and setting rate testing. Although the heel slurry samples were obtained from two separate vessels, the particle size distribution results were quite similar. The slurry solids were from approximately a minimum particle size of 0.5 mm to a maximum of 230 mm with about 90% of the material between 2-to-133 mm, and the cumulative 50% value at approximately 20 mm. This testing also revealed that high frequency sonication with an ultrasonic element may break-up larger particles in the WM-182 and WM-183 tank from heel slurries. This finding represents useful information regarding ultimate tank heel waste processing. Settling rate testing results were also fairly consistent with material from both vessels in that it appears that most of the mass of solids settle to an agglomerated, yet easily redispersed layer at the bottom. A dispersed and suspended material remained in the ''clear'' layer above the settled layer after about one-half an hour of settling time. This material had a statistical mode of approximately 5 mm and a maximum particle size of 30 mm

  20. Blast Exposure, White Matter Integrity, and Cognitive Function in Iraq and Afghanistan Combat Veterans

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    Erin A. Hazlett

    2017-04-01

    Full Text Available The long-term effects of blast exposure are a major health concern for combat veterans returning from the recent conflicts in Iraq and Afghanistan. We used an optimized diffusion tensor imaging tractography algorithm to assess white matter (WM fractional anisotropy (FA in blast-exposed Iraq and Afghanistan veterans (n = 40 scanned on average 3.7 years after deployment/trauma exposure. Veterans diagnosed with a blast-related mild traumatic brain injury (mTBI were compared to combat veterans with blast exposure but no TBI diagnosis. Blast exposure was associated with decreased FA in several WM tracts. However, total blast exposure did not correlate well with neuropsychological testing performance and there were no differences in FA based on mTBI diagnosis. Yet, veterans with mTBI performed worse on every neurocognitive test administered. Multiple linear regression across all blast-exposed veterans using a six-factor prediction model indicated that the amount of blast exposure accounted for 11–15% of the variability in composite FA scores such that as blast exposure increased, FA decreased. Education accounted for 10% of the variability in composite FA scores and 25–32% of FA variability in the right cingulum, such that as level of education increased, FA increased. Total blast exposure, age, and education were significant predictors of FA in the left cingulum. We did not find any effect of post-traumatic stress disorder on cognition or composite FA. In summary, our findings suggest that greater total blast exposure is a contributing factor to poor WM integrity. While FA was not associated with neurocognitive performance, we hypothesize that FA changes in the cingulum in veterans with multiple combat exposures and no head trauma prior to deployment may represent a marker of vulnerability for future deficits. Future work needs to examine this longitudinally.

  1. Abnormal white matter integrity in chronic users of codeine-containing cough syrups: a tract-based spatial statistics study.

    Science.gov (United States)

    Qiu, Y-W; Su, H-H; Lv, X-F; Jiang, G-H

    2015-01-01

    Codeine-containing cough syrups have become one of the most popular drugs of abuse in young people in the world. Chronic codeine-containing cough syrup abuse is related to impairments in a broad range of cognitive functions. However, the potential brain white matter impairment caused by chronic codeine-containing cough syrup abuse has not been reported previously. Our aim was to investigate abnormalities in the microstructure of brain white matter in chronic users of codeine-containing syrups and to determine whether these WM abnormalities are related to the duration of the use these syrups and clinical impulsivity. Thirty chronic codeine-containing syrup users and 30 matched controls were evaluated. Diffusion tensor imaging was performed by using a single-shot spin-echo-planar sequence. Whole-brain voxelwise analysis of fractional anisotropy was performed by using tract-based spatial statistics to localize abnormal WM regions. The Barratt Impulsiveness Scale 11 was surveyed to assess participants' impulsivity. Volume-of-interest analysis was used to detect changes of diffusivity indices in regions with fractional anisotropy abnormalities. Abnormal fractional anisotropy was extracted and correlated with clinical impulsivity and the duration of codeine-containing syrup use. Chronic codeine-containing syrup users had significantly lower fractional anisotropy in the inferior fronto-occipital fasciculus of the bilateral temporo-occipital regions, right frontal region, and the right corona radiata WM than controls. There were significant negative correlations among fractional anisotropy values of the right frontal region of the inferior fronto-occipital fasciculus and the right superior corona radiata WM and Barratt Impulsiveness Scale total scores, and between the right frontal region of the inferior fronto-occipital fasciculus and nonplan impulsivity scores in chronic codeine-containing syrup users. There was also a significant negative correlation between fractional

  2. PPAR-gamma agonist pioglitazone modifies craving intensity and brain white matter integrity in patients with primary cocaine use disorder: a double-blind randomized controlled pilot trial.

    Science.gov (United States)

    Schmitz, Joy M; Green, Charles E; Hasan, Khader M; Vincent, Jessica; Suchting, Robert; Weaver, Michael F; Moeller, F Gerard; Narayana, Ponnada A; Cunningham, Kathryn A; Dineley, Kelly T; Lane, Scott D

    2017-10-01

    Pioglitazone (PIO), a potent agonist of PPAR-gamma, is a promising candidate treatment for cocaine use disorder (CUD). We tested the effects of PIO on targeted mechanisms relevant to CUD: cocaine craving and brain white matter (WM) integrity. Feasibility, medication compliance and tolerability were evaluated. Two-arm double-blind randomized controlled proof-of-concept pilot trial of PIO or placebo (PLC). Single-site out-patient treatment research clinic in Houston, TX, USA. Thirty treatment-seeking adults, 18 to 60 years old, with CUD. Eighteen participants (8 = PIO; 10 = PLC) completed diffusion tensor imaging (DTI) of WM integrity at pre-/post-treatment. Study medication was dispensed at thrice weekly visits along with once-weekly cognitive behavioral therapy for 12 weeks. Measures of target engagement mechanisms of interest included cocaine craving assessed by the Brief Substance Craving Scale (BSCS), the Obsessive Compulsive Drug Use Scale (OCDUS), a visual analog scale (VAS) and change in WM integrity. Feasibility measures included number completing treatment, medication compliance (riboflavin detection) and tolerability (side effects, serious adverse events). Target engagement change in mechanisms of interest, defined as a ≥ 0.75 Bayesian posterior probability of an interaction existing favoring PIO over PLC, was demonstrated on measures of craving (BSCS, VAS) and WM integrity indexed by fractional anisotropy (FA) values. Outcomes indicated greater decrease in craving and greater increase in FA values in the PIO group. Feasibility was demonstrated by high completion rates among those starting treatment (21/26 = 80%) and medication compliance (≥ 80%). There were no reported serious adverse events for PIO. Compared with placebo, patients receiving pioglitazone show a higher likelihood of reduced cocaine craving and improved brain white matter integrity as a function of time in treatment. Pioglitazone shows good feasibility as a treatment for cocaine

  3. Joint assessment of white matter integrity, cortical and subcortical atrophy to distinguish AD from behavioral variant FTD: A two-center study

    Directory of Open Access Journals (Sweden)

    Christiane Möller

    2015-01-01

    Full Text Available We investigated the ability of cortical and subcortical gray matter (GM atrophy in combination with white matter (WM integrity to distinguish behavioral variant frontotemporal dementia (bvFTD from Alzheimer's disease (AD and from controls using voxel-based morphometry, subcortical structure segmentation, and tract-based spatial statistics. To determine which combination of MR markers differentiated the three groups with the highest accuracy, we conducted discriminant function analyses. Adjusted for age, sex and center, both types of dementia had more GM atrophy, lower fractional anisotropy (FA and higher mean (MD, axial (L1 and radial diffusivity (L23 values than controls. BvFTD patients had more GM atrophy in orbitofrontal and inferior frontal areas than AD patients. In addition, caudate nucleus and nucleus accumbens were smaller in bvFTD than in AD. FA values were lower; MD, L1 and L23 values were higher, especially in frontal areas of the brain for bvFTD compared to AD patients. The combination of cortical GM, hippocampal volume and WM integrity measurements, classified 97–100% of controls, 81–100% of AD and 67–75% of bvFTD patients correctly. Our results suggest that WM integrity measures add complementary information to measures of GM atrophy, thereby improving the classification between AD and bvFTD.

  4. White matter tract covariance patterns predict age-declining cognitive abilities.

    Science.gov (United States)

    Gazes, Yunglin; Bowman, F DuBois; Razlighi, Qolamreza R; O'Shea, Deirdre; Stern, Yaakov; Habeck, Christian

    2016-01-15

    Previous studies investigating the relationship of white matter (WM) integrity to cognitive abilities and aging have either focused on a global measure or a few selected WM tracts. Ideally, contribution from all of the WM tracts should be evaluated at the same time. However, the high collinearity among WM tracts precludes systematic examination of WM tracts simultaneously without sacrificing statistical power due to stringent multiple-comparison corrections. Multivariate covariance techniques enable comprehensive simultaneous examination of all WM tracts without being penalized for high collinearity among observations. In this study, Scaled Subprofile Modeling (SSM) was applied to the mean integrity of 18 major WM tracts to extract covariance patterns that optimally predicted four cognitive abilities (perceptual speed, episodic memory, fluid reasoning, and vocabulary) in 346 participants across ages 20 to 79years old. Using expression of the covariance patterns, age-independent effects of white matter integrity on cognition and the indirect effect of WM integrity on age-related differences in cognition were tested separately, but inferences from the indirect analyses were cautiously made given that cross-sectional data set was used in the analysis. A separate covariance pattern was identified that significantly predicted each cognitive ability after controlling for age except for vocabulary, but the age by WM covariance pattern interaction was not significant for any of the three abilities. Furthermore, each of the patterns mediated the effect of age on the respective cognitive ability. A distinct set of WM tracts was most influential in each of the three patterns. The WM covariance pattern accounting for fluid reasoning showed the most number of influential WM tracts whereas the episodic memory pattern showed the least number. Specific patterns of WM tracts make significant contributions to the age-related differences in perceptual speed, episodic memory, and

  5. Clinical Significance of Cerebrovascular Biomarkers and White Matter Tract Integrity in Alzheimer Disease: Clinical correlations With Neurobehavioral Data in Cross-Sectional and After 18 Months Follow-ups.

    Science.gov (United States)

    Wu, Ming-Kung; Lu, Yan-Ting; Huang, Chi-Wei; Lin, Pin-Hsuan; Chen, Nai-Ching; Lui, Chun-Chung; Chang, Wen-Neng; Lee, Chen-Chang; Chang, Ya-Ting; Chen, Sz-Fan; Chang, Chiung-Chih

    2015-07-01

    Cerebrovascular risk factors and white matter (WM) damage lead to worse cognitive performance in Alzheimer dementia (AD). This study investigated WM microstructure using diffusion tensor imaging in patients with mild to moderate AD and investigated specific fiber tract involvement with respect to predefined cerebrovascular risk factors and neurobehavioral data prediction cross-sectionally and after 18 months. To identify the primary pathoanatomic relationships of risk biomarkers to fiber tract integrity, we predefined 11 major association tracts and calculated tract specific fractional anisotropy (FA) values. Eighty-five patients with AD underwent neurobehavioral assessments including the minimental state examination (MMSE) and 12-item neuropsychiatric inventory twice with a 1.5-year interval to represent major outcome factors. In the cross-sectional data, total cholesterol, low-density lipoprotein, vitamin B12, and homocysteine levels correlated variably with WM FA values. After entering the biomarkers and WM FA into a regression model to predict neurobehavioral outcomes, only fiber tract FA or homocysteine level predicted the MMSE score, and fiber tract FA or age predicted the neuropsychiatric inventory total scores and subdomains of apathy, disinhibition, and aberrant motor behavior. In the follow-up neurobehavioral data, the mean global FA value predicted the MMSE and aberrant motor behavior subdomain, while age predicted the anxiety and elation subdomains. Cerebrovascular risk biomarkers may modify WM microstructural organization, while the association with fiber integrity showed greater clinical significance to the prediction of neurobehavioral outcomes both cross-sectionally and longitudinally.

  6. Diminished white matter integrity in patients with systemic lupus erythematosus

    Directory of Open Access Journals (Sweden)

    Tobias Schmidt-Wilcke

    2014-01-01

    Conclusions: Our data suggest that changes in regional white matter integrity, in terms of a decrease in FA, are present not only in NPSLE patients, but also in non-NPSLE patients, though to a lesser degree. We also demonstrate that the way statistical maps are corrected for multiple comparisons has a profound influence on whether alterations in white matter integrity in non-NPSLE patients are deemed significant.

  7. Alterations of White Matter Integrity and Hippocampal Functional Connectivity in Type 2 Diabetes Without Mild Cognitive Impairment

    Directory of Open Access Journals (Sweden)

    Qian Sun

    2018-03-01

    Full Text Available Aims: To investigate the white matter (WM integrity and hippocampal functional connectivity (FC in type 2 diabetes mellitus (T2DM patients without mild cognitive impairment (MCI by using diffusion tensor imaging (DTI and resting-state functional magnetic resonance imaging (rs-fMRI, respectively.Methods: Twelve T2DM patients without MCI and 24 age, sex and education matched healthy controls (HC were recruited. DTI and rs-fMRI data were subsequently acquired on a 3.0T MR scanner. Tract-based spatial statistics (TBSS combining region of interests (ROIs analysis was used to investigate the alterations of DTI metrics (fractional anisotropy (FA, mean diffusivity (MD, λ1 and λ23 and FC measurement was performed to calculate hippocampal FC with other brain regions. Cognitive function was evaluated by using Mini-Mental State Examination (MMSE and Montreal Cognitive Assessment (MoCA. Brain volumes were also evaluated among these participants.Results: There were no difference of MMSE and MoCA scores between two groups. Neither whole brain nor regional brain volume decrease was revealed in T2DM patients without MCI. DTI analysis revealed extensive WM disruptions, especially in the body of corpus callosum (CC. Significant decreases of hippocampal FC with certain brain structures were revealed, especially with the bilateral frontal cortex. Furthermore, the decreased FA in left posterior thalamic radiation (PTR and increased MD in the splenium of CC were closely related with the decreased hippocampal FC to caudate nucleus and frontal cortex.Conclusions: T2DM patients without MCI showed extensive WM disruptions and abnormal hippocampal FC. Moreover, the WM disruptions and abnormal hippocampal FC were closely associated.Highlights-T2DM patients without MCI demonstrated no obvious brain volume decrease.-Extensive white matter disruptions, especially within the body of corpus callosum, were revealed with DTI analysis among the T2DM patients.-Despite no MCI in T2

  8. Deep white matter hyperintensities, microstructural integrity and dual task walking in older people.

    Science.gov (United States)

    Ghanavati, Tabassom; Smitt, Myriam Sillevis; Lord, Stephen R; Sachdev, Perminder; Wen, Wei; Kochan, Nicole A; Brodaty, Henry; Delbaere, Kim

    2018-01-03

    To examine neural, physiological and cognitive influences on gait speed under single and dual-task conditions. Sixty-two community-dwelling older people (aged 80.0 ± 4.2 years) participated in our study. Gait speed was assessed with a timed 20-meter walk under single and dual-task (reciting alternate letters of the alphabet) conditions. Participants also underwent tests to estimate physiological fall risk based on five measures of sensorimotor function, cognitive function across five domains, brain white matter (WM) hyperintensities and WM microstructural integrity by measuring fractional anisotropy (FA). Univariate linear regression analyses showed that global physiological and cognitive measures were associated with single (β = 0.594 and β=-0.297, respectively) and dual-task gait speed (β = 0.306 and β=-0.362, respectively). Deep WMHs were associated with dual-task gait speed only (β = 0.257). Multivariate mediational analyses showed that global and executive cognition reduced the strength of the association between deep WMHs and dual-task gait speed by 27% (β = 0.188) and 44% (β = 0.145) respectively. There was a significant linear association between single-task gait speed and mean FA values of the genu (β=-0.295) and splenium (β=-0.326) of the corpus callosum, and between dual-task gait speed and mean FA values of Superior Cerebellar Peduncle (β=-0.284), splenium of the Corpus Callosum (β=-0.286) and Cingulum (β=-0.351). Greater deep WMH volumes are associated with slower walking speed under dual-task conditions, and this relationship is mediated in part by global cognition and executive abilities specifically. Furthermore, both cerebellum and cingulum are related to dual-task walking due to their role in motor skill performance and attention, respectively.

  9. Light Duty Utility Arm deployment in Tank WM-188

    International Nuclear Information System (INIS)

    Patterson, M.

    1999-01-01

    The Light Duty Utility Arm (LDUA) was successfully deployed in Tank WM-188 during February and March of 1999 at the Idaho Nuclear Technology and Engineering Center (INTEC) tank farm at the Idaho National Engineering and Environmental Laboratory. Some equipment problems were identified, but most were indicative of any first time activity. Deployment during cold weather imposed additional equipment risks, but in general, equipment response to the winter conditions was better than expected. Three end effectors were demonstrated during the deployment. All performed as expected, although the limited resolution of the Alternating Current Field Measurement end effector cannot absolutely confirm tank integrity, which is necessary for future tank inspections. Four heel samples were taken with the sampler end effector and a broad spectrum of analyses were performed. A detailed inspection of the tank interior was performed with the High Resolution Stereo Video System end effector. The sample information is proving invaluable to the development of new treatment flowsheets and waste forms. It is expected that the LDUA will be deployed for tank inspections through the next several years to support other Notice of Non-Compliance (NON) Consent Order requirements and several other ongoing initiatives

  10. Light Duty Utility Arm deployment in Tank WM-188

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, M.W.

    1999-12-01

    The Light Duty Utility Arm (LDUA) was successfully deployed in Tank WM-188 during February and March of 1999 at the Idaho Nuclear Technology and Engineering Center (INTEC) tank farm at the Idaho National Engineering and Environmental Laboratory. Some equipment problems were identified, but most were indicative of any first time activity. Deployment during cold weather imposed additional equipment risks, but in general, equipment response to the winter conditions was better than expected. Three end effectors were demonstrated during the deployment. All performed as expected, although the limited resolution of the Alternating Current Field Measurement end effector cannot absolutely confirm tank integrity, which is necessary for future tank inspections. Four heel samples were taken with the sampler end effector and a broad spectrum of analyses were performed. A detailed inspection of the tank interior was performed with the High Resolution Stereo Video System end effector. The sample information is proving invaluable to the development of new treatment flowsheets and waste forms. It is expected that the LDUA will be deployed for tank inspections through the next several years to support other Notice of Non-Compliance (NON) Consent Order requirements and several other ongoing initiatives.

  11. Light Duty Utility Arm Deployment in Tank WM-188

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, Michael W

    2000-01-01

    The Light Duty Utility Arm (LDUA) was successfully deployed in Tank WM-188 during February and March of 1999 at the Idaho Nuclear Technology and Engineering Center (INTEC) tank farm at the Idaho National Engineering and Environmental Laboratory. Some equipment problems were identified, but most were indicative of any first time activity. Deployment during cold weather imposed additional equipment risks, but in general, equipment response to the winter conditions was better than expected. Three end effectors were demonstrated during the deployment. All performed as expected, although the limited resolution of the Alternating Current Field Measurement end effector cannot absolutely confirm tank integrity, which is necessary for future tank inspections. Four heel samples were taken with the sampler end effector and a broad spectrum of analyses were performed. A detailed inspection of the tank interior was performed with the High Resolution Stereo Video System end effector. The sample information is proving invaluable to the development of new treatment flowsheets and waste forms. It is expected that the LDUA will be deployed for tank inspections through the next several years to support other Notice of NonCompliance (NON) Consent Order requirements and several other ongoing initiatives.

  12. Integrating retrogenesis theory to Alzheimer's disease pathology: insight from DTI-TBSS investigation of the white matter microstructural integrity.

    Science.gov (United States)

    Alves, Gilberto Sousa; Oertel Knöchel, Viola; Knöchel, Christian; Carvalho, André Férrer; Pantel, Johannes; Engelhardt, Eliasz; Laks, Jerson

    2015-01-01

    Microstructural abnormalities in white matter (WM) are often reported in Alzheimer's disease (AD) and may reflect primary or secondary circuitry degeneration (i.e., due to cortical atrophy). The interpretation of diffusion tensor imaging (DTI) eigenvectors, known as multiple indices, may provide new insights into the main pathological models supporting primary or secondary patterns of WM disruption in AD, the retrogenesis, and Wallerian degeneration models, respectively. The aim of this review is to analyze the current literature on the contribution of DTI multiple indices to the understanding of AD neuropathology, taking the retrogenesis model as a reference for discussion. A systematic review using MEDLINE, EMBASE, and PUBMED was performed. Evidence suggests that AD evolves through distinct patterns of WM disruption, in which retrogenesis or, alternatively, the Wallerian degeneration may prevail. Distinct patterns of WM atrophy may be influenced by complex interactions which comprise disease status and progression, fiber localization, concurrent risk factors (i.e., vascular disease, gender), and cognitive reserve. The use of DTI multiple indices in addition to other standard multimodal methods in dementia research may help to determine the contribution of retrogenesis hypothesis to the understanding of neuropathological hallmarks that lead to AD.

  13. White matter integrity in brain networks relevant to anxiety and depression: evidence from the human connectome project dataset.

    Science.gov (United States)

    De Witte, Nele A J; Mueller, Sven C

    2017-12-01

    Anxiety and depression are associated with altered communication within global brain networks and between these networks and the amygdala. Functional connectivity studies demonstrate an effect of anxiety and depression on four critical brain networks involved in top-down attentional control (fronto-parietal network; FPN), salience detection and error monitoring (cingulo-opercular network; CON), bottom-up stimulus-driven attention (ventral attention network; VAN), and default mode (default mode network; DMN). However, structural evidence on the white matter (WM) connections within these networks and between these networks and the amygdala is lacking. The current study in a large healthy sample (n = 483) observed that higher trait anxiety-depression predicted lower WM integrity in the connections between amygdala and specific regions of the FPN, CON, VAN, and DMN. We discuss the possible consequences of these anatomical alterations for cognitive-affective functioning and underscore the need for further theory-driven research on individual differences in anxiety and depression on brain structure.

  14. Normal white matter microstructure in women long-term recovered from anorexia nervosa: A diffusion tensor imaging study.

    Science.gov (United States)

    Bang, Lasse; Rø, Øyvind; Endestad, Tor

    2018-01-01

    Studies point to white matter (WM) microstructure alterations in both adolescent and adult patients with anorexia nervosa (AN). These include reduced fractional anisotropy in several WM fiber tracts, suggesting reduced WM integrity. The extent to which these alterations are reversible with recovery from AN is unclear. There is a paucity of research investigating the presence of WM microstructure alterations in recovered AN patients, and results are inconsistent. This study aimed to investigate the presence of WM microstructure alterations in women long-term recovered from AN. Twenty-one adult women who were recovered from AN for at least 1 year were compared to 21 adult comparison women. Participants were recruited via user-organizations for eating disorders, local advertisements, and online forums. Diffusion tensor imaging was used to compare WM microstructure between groups. Correlations between WM microstructure and clinical characteristics were also explored. There were no statistically significant between-group differences in WM microstructure. These null findings remained when employing liberal alpha level thresholds. Furthermore, there were no statistically significant correlations between WM microstructure and clinical characteristics. Our findings showed normal WM microstructure in long-term recovered patients, indicating the alterations observed during the acute phase are reversible. Given the paucity of research and inconsistent findings, future studies are warranted to determine the presence of WM microstructure alterations following recovery from AN. © 2017 Wiley Periodicals, Inc.

  15. White matter integrity in dyskinetic cerebral palsy: Relationship with intelligence quotient and executive function

    Directory of Open Access Journals (Sweden)

    Olga Laporta-Hoyos

    2017-01-01

    Conclusion: The widespread loss in the integrity of WM tissue is mainly located in the parietal lobe and related to IQ in dyskinetic CP. Unexpectedly, executive functions are only related with WM microstructure in regions containing fronto-cortical and posterior cortico-subcortical pathways, and not being specifically related to the state of fronto-striatal pathways which might be due to brain reorganization. Further studies of this nature may improve our understanding of the neurobiological bases of cognitive impairments after early brain insult.

  16. Waste Management Fault Tree Data Bank (WM): 1992 status report

    International Nuclear Information System (INIS)

    Baughman, D.F.; Hang, P.; Townsend, C.S.

    1993-01-01

    The Risk Assessment Methodology Group (RAM) of the Nuclear Process Safety Research Section (NPSR) maintains a compilation of incidents that have occurred in the Waste Management facilities. The Waste Management Fault Tree Data Bank (WM) contains more than 35,000 entries ranging from minor equipment malfunctions to incidents with significant potential for injury or contamination of personnel. This report documents the status of the WM data bank including: availability, training, source of data, search options, and usage, to which these data have been applied. Periodic updates to this memorandum are planned as additional data or applications are acquired

  17. White matter tract integrity in treatment-resistant gambling disorder

    DEFF Research Database (Denmark)

    Chamberlain, Samuel R.; Derbyshire, Katherine; Daws, Richard E.

    2016-01-01

    Background: Gambling disorder is a relatively common psychiatric disorder recently re-classified within the DSM-5 under the category of ‘substance-related and addictive disorders’. Aims: To compare white matter integrity in patients with gambling disorder with healthy controls; to explore...

  18. Wind Turbine Test. Wind Matic WM 17S

    DEFF Research Database (Denmark)

    Friis Pedersen, Troels

    The report describes standard measurements performed on a Wind-Matic WM 17S, 75 kW wind turbine. The measurements carried out and reported here comprises the power output, system efficiency, energy production, transmission efficiency, rotor power, rotor efficiency, air-brakes efficiency, structural...

  19. Wind Turbine Test Wind Matic WM 15S

    DEFF Research Database (Denmark)

    Friis Pedersen, Troels

    The report describes standard measurements performed on a Wind-Matic WM 15S, 55 kW wind turbine. The measurements carried out and reported here comprises the power output, system efficiency, energy production, transmission efficiency, rotor power, rotor efficiency, air-brakes efficiency, dynamical...

  20. White matter integrity in kleptomania: A pilot study

    Science.gov (United States)

    Grant, Jon E.; Correia, Stephen; Brennan-Krohn, Thea

    2007-01-01

    This study's goal was to examine microstructural organization of frontal white matter in kleptomania. Ten females with DSM-IV kleptomania and 10 female controls underwent diffusion tensor imaging. Inferior frontal white matter was the a priori region of interest. Trace and fractional anisotropy (FA) were also calculated for frontal and posterior cortical regions in both subject groups. Kleptomania subjects had significantly higher mean frontal Trace, and significantly lower mean frontal FA than control subjects. Group differences remained significant when right and left frontal Trace and FA were analyzed. Groups did not differ significantly in posterior Trace or FA. Kleptomania may be associated with decreased white matter microstructural integrity in inferior frontal brain regions. PMID:16956753

  1. Corrosion Evaluation of INTEC Waste Storage Tank WM-182

    International Nuclear Information System (INIS)

    Dirk, W. J.; Anderson, P. A.

    1999-01-01

    Irradiated nuclear fuel has been stored and reprocessed at the Idaho National Engineering and Environmental Laboratory since 1953 using facilities located at the Idaho Nuclear Technology and Engineering Center (INTEC). This reprocessing produced radioactive liquid waste which was stored in the Tank Farm. The INTEC Tank Farm consists of eleven vaulted 300,000-gallon underground tanks including Tank WM-182. Tank WM-182 was put into service in 1955, has been filled four times, and has contained aluminum and zirconium fuel reprocessing wastes as well as sodium bearing waste. A program to monitor corrosion in the waste tanks was initiated in 1953 when the first of the eleven Tank Farm tanks was placed in service. Austenitic stainless steel coupons representative of the materials of construction of the tanks are used to monitor internal tank corrosion. This report documents the final inspection of the WM-182 corrosion coupons. Physical examination of the welded corrosion test coupons exposed to the tank bottom conditions of Tank WM-182 revealed very light uniform corrosion. Examination of the external surfaces of the extruded pipe samples showed very light uniform corrosion with slight indications of preferential attack parallel to extrusion marks and start of end grain attack of the cut edges. These indications were only evident when examined under stereo microscope at magnifications of 20X and above. There were no definite indications of localized corrosion, such as cracking, pitting, preferential weld attack, or weld heat affected zone attack on either the welded or extruded coupons. Visual examination of the coupon support cables, where they were not encased in plastic, failed to reveal any indication of liquid-liquid interface attack of any crevice corrosion. Based on the WM-182 coupon evaluations, which have occurred throughout the life of the tank, the metal loss from the tank wall due to uniform corrosion is not expected to exceed 5.5 x 10-1 mil (0.00 055 inch

  2. Abnormal brain white matter network in young smokers: a graph theory analysis study.

    Science.gov (United States)

    Zhang, Yajuan; Li, Min; Wang, Ruonan; Bi, Yanzhi; Li, Yangding; Yi, Zhang; Liu, Jixin; Yu, Dahua; Yuan, Kai

    2018-04-01

    Previous diffusion tensor imaging (DTI) studies had investigated the white matter (WM) integrity abnormalities in some specific fiber bundles in smokers. However, little is known about the changes in topological organization of WM structural network in young smokers. In current study, we acquired DTI datasets from 58 male young smokers and 51 matched nonsmokers and constructed the WM networks by the deterministic fiber tracking approach. Graph theoretical analysis was used to compare the topological parameters of WM network (global and nodal) and the inter-regional fractional anisotropy (FA) weighted WM connections between groups. The results demonstrated that both young smokers and nonsmokers had small-world topology in WM network. Further analysis revealed that the young smokers exhibited the abnormal topological organization, i.e., increased network strength, global efficiency, and decreased shortest path length. In addition, the increased nodal efficiency predominately was located in frontal cortex, striatum and anterior cingulate gyrus (ACG) in smokers. Moreover, based on network-based statistic (NBS) approach, the significant increased FA-weighted WM connections were mainly found in the PFC, ACG and supplementary motor area (SMA) regions. Meanwhile, the network parameters were correlated with the nicotine dependence severity (FTND) scores, and the nodal efficiency of orbitofrontal cortex was positive correlation with the cigarette per day (CPD) in young smokers. We revealed the abnormal topological organization of WM network in young smokers, which may improve our understanding of the neural mechanism of young smokers form WM topological organization level.

  3. The effects of bilingualism on the white matter structure of the brain.

    Science.gov (United States)

    Pliatsikas, Christos; Moschopoulou, Elisavet; Saddy, James Douglas

    2015-02-03

    Recent studies suggest that learning and using a second language (L2) can affect brain structure, including the structure of white matter (WM) tracts. This observation comes from research looking at early and older bilingual individuals who have been using both their first and second languages on an everyday basis for many years. This study investigated whether young, highly immersed late bilinguals would also show structural effects in the WM that can be attributed to everyday L2 use, irrespective of critical periods or the length of L2 learning. Our Tract-Based Spatial Statistics analysis revealed higher fractional anisotropy values for bilinguals vs. monolinguals in several WM tracts that have been linked to language processing and in a pattern closely resembling the results reported for older and early bilinguals. We propose that learning and actively using an L2 after childhood can have rapid dynamic effects on WM structure, which in turn may assist in preserving WM integrity in older age.

  4. White matter hyperintensities and normal-appearing white matter integrity in the aging brain.

    Science.gov (United States)

    Maniega, Susana Muñoz; Valdés Hernández, Maria C; Clayden, Jonathan D; Royle, Natalie A; Murray, Catherine; Morris, Zoe; Aribisala, Benjamin S; Gow, Alan J; Starr, John M; Bastin, Mark E; Deary, Ian J; Wardlaw, Joanna M

    2015-02-01

    White matter hyperintensities (WMH) of presumed vascular origin are a common finding in brain magnetic resonance imaging of older individuals and contribute to cognitive and functional decline. It is unknown how WMH form, although white matter degeneration is characterized pathologically by demyelination, axonal loss, and rarefaction, often attributed to ischemia. Changes within normal-appearing white matter (NAWM) in subjects with WMH have also been reported but have not yet been fully characterized. Here, we describe the in vivo imaging signatures of both NAWM and WMH in a large group of community-dwelling older people of similar age using biomarkers derived from magnetic resonance imaging that collectively reflect white matter integrity, myelination, and brain water content. Fractional anisotropy (FA) and magnetization transfer ratio (MTR) were significantly lower, whereas mean diffusivity (MD) and longitudinal relaxation time (T1) were significantly higher, in WMH than NAWM (p curve, 0.982; 95% CI, 0.975-0.989). Furthermore, the level of deterioration of NAWM was strongly associated with the severity of WMH, with MD and T1 increasing and FA and MTR decreasing in NAWM with increasing WMH score, a relationship that was sustained regardless of distance from the WMH. These multimodal imaging data indicate that WMH have reduced structural integrity compared with surrounding NAWM, and MD provides the best discriminator between the 2 tissue classes even within the mild range of WMH severity, whereas FA, MTR, and T1 only start reflecting significant changes in tissue microstructure as WMH become more severe. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Comparison of Multi-Tensor Diffusion Models' Performance for White Matter Integrity Estimation in Chronic Stroke

    Directory of Open Access Journals (Sweden)

    Olena G. Filatova

    2018-04-01

    Full Text Available Better insight into white matter (WM alterations after stroke onset could help to understand the underlying recovery mechanisms and improve future interventions. MR diffusion imaging enables to assess such changes. Our goal was to investigate the relation of WM diffusion characteristics derived from diffusion models of increasing complexity with the motor function of the upper limb. Moreover, we aimed to evaluate the variation of such characteristics across different WM structures of chronic stroke patients in comparison to healthy subjects. Subjects were scanned with a two b-value diffusion-weighted MRI protocol to exploit multiple diffusion models: single tensor, single tensor with isotropic compartment, bi-tensor model, bi-tensor with isotropic compartment. From each model we derived the mean tract fractional anisotropy (FA, mean (MD, radial (RD and axial (AD diffusivities outside the lesion site based on a WM tracts atlas. Asymmetry of these measures was correlated with the Fugl-Meyer upper extremity assessment (FMA score and compared between patient and control groups. Eighteen chronic stroke patients and eight age-matched healthy individuals participated in the study. Significant correlation of the outcome measures with the clinical scores of stroke recovery was found. The lowest correlation of the corticospinal tract FAasymmetry and FMA was with the single tensor model (r = −0.3, p = 0.2 whereas the other models reported results in the range of r = −0.79 ÷ −0.81 and p = 4E-5 ÷ 8E-5. The corticospinal tract and superior longitudinal fasciculus showed most alterations in our patient group relative to controls. Multiple compartment models yielded superior correlation of the diffusion measures and FMA compared to the single tensor model.

  6. Decreased Number of Self-Paced Saccades in Post-Concussion Syndrome Associated with Higher Symptom Burden and Reduced White Matter Integrity.

    Science.gov (United States)

    Taghdiri, Foad; Chung, Jonathan; Irwin, Samantha; Multani, Namita; Tarazi, Apameh; Ebraheem, Ahmed; Khodadadi, Mozghan; Goswami, Ruma; Wennberg, Richard; Mikulis, David; Green, Robin; Davis, Karen; Tator, Charles; Eizenman, Moshe; Tartaglia, Maria Carmela

    2018-03-01

    The aim of this study was to examine the potential utility of a self-paced saccadic eye movement as a marker of post-concussion syndrome (PCS) and monitoring the recovery from PCS. Fifty-nine persistently symptomatic participants with at least two concussions performed the self-paced saccade (SPS) task. We evaluated the relationships between the number of SPSs and 1) number of self-reported concussion symptoms, and 2) integrity of major white matter (WM) tracts (as measured by fractional anisotropy [FA] and mean diffusivity) that are directly or indirectly involved in saccadic eye movements and often affected by concussion. These tracts included the uncinate fasciculus (UF), cingulum (Cg) and its three subcomponents (subgenual, retrosplenial, and parahippocampal), superior longitudinal fasciculus, and corpus callosum. Mediation analyses were carried out to examine whether specific WM tracts (left UF and left subgenual Cg) mediated the relationship between the number of SPSs and 1) interval from last concussion or 2) total number of self-reported symptoms. The number of SPSs was negatively correlated with the total number of self-reported symptoms (r = -0.419, p = 0.026). The number of SPSs were positively correlated with FA of left UF and left Cg (r = 0.421, p = 0.013 and r = 0.452, p = 0.008; respectively). FA of the subgenual subcomponent of the left Cg partially mediated the relationship between the total number of symptoms and the number of SPSs, while FA of the left UF mediated the relationship between interval from last concussion and the number of SPSs. In conclusion, SPS testing as a fast and objective assessment may reflect symptom burden in patients with PCS. In addition, since the number of SPSs is associated with the integrity of some WM tracts, it may be useful as a diagnostic biomarker in patients with PCS.

  7. Frontoparietal white matter integrity predicts haptic performance in chronic stroke

    Directory of Open Access Journals (Sweden)

    Alexandra L. Borstad

    2016-01-01

    Full Text Available Frontoparietal white matter supports information transfer between brain areas involved in complex haptic tasks such as somatosensory discrimination. The purpose of this study was to gain an understanding of the relationship between microstructural integrity of frontoparietal network white matter and haptic performance in persons with chronic stroke and to compare frontoparietal network integrity in participants with stroke and age matched control participants. Nineteen individuals with stroke and 16 controls participated. Haptic performance was quantified using the Hand Active Sensation Test (HASTe, an 18-item match-to-sample test of weight and texture discrimination. Three tesla MRI was used to obtain diffusion-weighted and high-resolution anatomical images of the whole brain. Probabilistic tractography was used to define 10 frontoparietal tracts total; Four intrahemispheric tracts measured bilaterally 1 thalamus to primary somatosensory cortex (T–S1, 2 thalamus to primary motor cortex (T–M1, 3 primary to secondary somatosensory cortex (S1 to SII and 4 primary somatosensory cortex to middle frontal gyrus (S1 to MFG and, 2 interhemispheric tracts; S1–S1 and precuneus interhemispheric. A control tract outside the network, the cuneus interhemispheric tract, was also examined. The diffusion metrics fractional anisotropy (FA, mean diffusivity (MD, axial (AD and radial diffusivity (RD were quantified for each tract. Diminished FA and elevated MD values are associated with poorer white matter integrity in chronic stroke. Nine of 10 tracts quantified in the frontoparietal network had diminished structural integrity poststroke compared to the controls. The precuneus interhemispheric tract was not significantly different between groups. Principle component analysis across all frontoparietal white matter tract MD values indicated a single factor explained 47% and 57% of the variance in tract mean diffusivity in stroke and control groups respectively

  8. Frontoparietal white matter integrity predicts haptic performance in chronic stroke.

    Science.gov (United States)

    Borstad, Alexandra L; Choi, Seongjin; Schmalbrock, Petra; Nichols-Larsen, Deborah S

    2016-01-01

    Frontoparietal white matter supports information transfer between brain areas involved in complex haptic tasks such as somatosensory discrimination. The purpose of this study was to gain an understanding of the relationship between microstructural integrity of frontoparietal network white matter and haptic performance in persons with chronic stroke and to compare frontoparietal network integrity in participants with stroke and age matched control participants. Nineteen individuals with stroke and 16 controls participated. Haptic performance was quantified using the Hand Active Sensation Test (HASTe), an 18-item match-to-sample test of weight and texture discrimination. Three tesla MRI was used to obtain diffusion-weighted and high-resolution anatomical images of the whole brain. Probabilistic tractography was used to define 10 frontoparietal tracts total; Four intrahemispheric tracts measured bilaterally 1) thalamus to primary somatosensory cortex (T-S1), 2) thalamus to primary motor cortex (T-M1), 3) primary to secondary somatosensory cortex (S1 to SII) and 4) primary somatosensory cortex to middle frontal gyrus (S1 to MFG) and, 2 interhemispheric tracts; S1-S1 and precuneus interhemispheric. A control tract outside the network, the cuneus interhemispheric tract, was also examined. The diffusion metrics fractional anisotropy (FA), mean diffusivity (MD), axial (AD) and radial diffusivity (RD) were quantified for each tract. Diminished FA and elevated MD values are associated with poorer white matter integrity in chronic stroke. Nine of 10 tracts quantified in the frontoparietal network had diminished structural integrity poststroke compared to the controls. The precuneus interhemispheric tract was not significantly different between groups. Principle component analysis across all frontoparietal white matter tract MD values indicated a single factor explained 47% and 57% of the variance in tract mean diffusivity in stroke and control groups respectively. Age

  9. Reduced anterior internal capsule white matter integrity in primary insomnia.

    Science.gov (United States)

    Spiegelhalder, Kai; Regen, Wolfram; Prem, Martin; Baglioni, Chiara; Nissen, Christoph; Feige, Bernd; Schnell, Susanne; Kiselev, Valerij G; Hennig, Jürgen; Riemann, Dieter

    2014-07-01

    Chronic insomnia is one of the most prevalent central nervous system diseases, however, its neurobiology is poorly understood. Up to now, nothing is known about the integrity of white matter tracts in insomnia patients. In this study, diffusion tensor imaging (DTI) was used in a well-characterized sample of primary insomnia (PI) patients and good sleeper controls to fill this void. Voxelwise between-group comparisons of fractional anisotropy (FA) were performed in 24 PI patients (10 males; 14 females; 42.7 ± 14.5 years) and 35 healthy good sleepers (15 males; 20 females; 40.1 ± 9.1 years) with age and sex as covariates. PI patients showed reduced FA values within the right anterior internal capsule and a trend for reduced FA values in the left anterior internal capsule. The results suggest that insomnia is associated with a reduced integrity of white matter tracts in the anterior internal capsule indicating that disturbed fronto-subcortical connectivity may be a cause or consequence of the disorder.

  10. Neurotransmitter signaling in white matter.

    Science.gov (United States)

    Butt, Arthur M; Fern, Robert F; Matute, Carlos

    2014-11-01

    White matter (WM) tracts are bundles of myelinated axons that provide for rapid communication throughout the CNS and integration in grey matter (GM). The main cells in myelinated tracts are oligodendrocytes and astrocytes, with small populations of microglia and oligodendrocyte precursor cells. The prominence of neurotransmitter signaling in WM, which largely exclude neuronal cell bodies, indicates it must have physiological functions other than neuron-to-neuron communication. A surprising aspect is the diversity of neurotransmitter signaling in WM, with evidence for glutamatergic, purinergic (ATP and adenosine), GABAergic, glycinergic, adrenergic, cholinergic, dopaminergic and serotonergic signaling, acting via a wide range of ionotropic and metabotropic receptors. Both axons and glia are potential sources of neurotransmitters and may express the respective receptors. The physiological functions of neurotransmitter signaling in WM are subject to debate, but glutamate and ATP-mediated signaling have been shown to evoke Ca(2+) signals in glia and modulate axonal conduction. Experimental findings support a model of neurotransmitters being released from axons during action potential propagation acting on glial receptors to regulate the homeostatic functions of astrocytes and myelination by oligodendrocytes. Astrocytes also release neurotransmitters, which act on axonal receptors to strengthen action potential propagation, maintaining signaling along potentially long axon tracts. The co-existence of multiple neurotransmitters in WM tracts suggests they may have diverse functions that are important for information processing. Furthermore, the neurotransmitter signaling phenomena described in WM most likely apply to myelinated axons of the cerebral cortex and GM areas, where they are doubtless important for higher cognitive function. © 2014 Wiley Periodicals, Inc.

  11. Memory binding and white matter integrity in familial Alzheimer's disease.

    Science.gov (United States)

    Parra, Mario A; Saarimäki, Heini; Bastin, Mark E; Londoño, Ana C; Pettit, Lewis; Lopera, Francisco; Della Sala, Sergio; Abrahams, Sharon

    2015-05-01

    Binding information in short-term and long-term memory are functions sensitive to Alzheimer's disease. They have been found to be affected in patients who meet criteria for familial Alzheimer's disease due to the mutation E280A of the PSEN1 gene. However, only short-term memory binding has been found to be affected in asymptomatic carriers of this mutation. The neural correlates of this dissociation are poorly understood. The present study used diffusion tensor magnetic resonance imaging to investigate whether the integrity of white matter structures could offer an account. A sample of 19 patients with familial Alzheimer's disease, 18 asymptomatic carriers and 21 non-carrier controls underwent diffusion tensor magnetic resonance imaging, neuropsychological and memory binding assessment. The short-term memory binding task required participants to detect changes across two consecutive screens displaying arrays of shapes, colours, or shape-colour bindings. The long-term memory binding task was a Paired Associates Learning Test. Performance on these tasks were entered into regression models. Relative to controls, patients with familial Alzheimer's disease performed poorly on both memory binding tasks. Asymptomatic carriers differed from controls only in the short-term memory binding task. White matter integrity explained poor memory binding performance only in patients with familial Alzheimer's disease. White matter water diffusion metrics from the frontal lobe accounted for poor performance on both memory binding tasks. Dissociations were found in the genu of corpus callosum which accounted for short-term memory binding impairments and in the hippocampal part of cingulum bundle which accounted for long-term memory binding deficits. The results indicate that white matter structures in the frontal and temporal lobes are vulnerable to the early stages of familial Alzheimer's disease and their damage is associated with impairments in two memory binding functions known to

  12. Long-term prognosis of geriatric major depression in relation to cognition and white matter integrity: follow up of two cases

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo de Oliveira Alves

    2012-01-01

    Full Text Available INTRODUCTION: The geriatric depression (GD represents one of the most frequent psychiatric disorders in outpatient services specialized in old-age treatment. OBJECTIVE: The course of two illustrative cases of GD is discussed, highlighting its clinical picture after antidepressant treatment and underlining variables related to disease prognosis, treatment effectiveness and conversion to major cognitive disorders such as vascular dementia (VD. METHODS: The cognitive performance, depressive symptoms, autonomy and brain structural measurements as white matter hyperintensities (WMH and hippocampal size, and microstructural integrity of WM with diffusion tensor imaging were followed during four years. RESULTS: Case 1, with a severe degree of WMH, was associated with worsening cognition and increasing functional disability. Case 2, with mild WMH, an improvement of cognitive functioning could be seen. CONCLUSIONS: The existence of different subtypes of GD, as presented in this report, points a pathophysiological heterogeneity of GD, and suggests a possible continuum vascular depression (VaDp and vascular cognitive impairment (VCI.

  13. Frontal white matter alterations in short-term medicated panic disorder patients without comorbid conditions: a diffusion tensor imaging study.

    Directory of Open Access Journals (Sweden)

    Borah Kim

    Full Text Available The frontal cortex might play an important role in the fear network, and white matter (WM integrity could be related to the pathophysiology of panic disorder (PD. A few studies have investigated alterations of WM integrity in PD. The aim of this study was to determine frontal WM integrity differences between patients with PD without comorbid conditions and healthy control (HC subjects by using diffusion tensor imaging. Thirty-six patients with PD who had used medication within 1 week and 27 age- and sex-matched HC subjects participated in this study. Structural brain magnetic resonance imaging was performed on all participants. Panic Disorder Severity Scale and Beck Anxiety Inventory (BAI scores were assessed. Tract-based spatial statistics (TBSS was used for image analysis. TBSS analysis showed decreased fractional anisotropy (FA in frontal WM and WM around the frontal lobe, including the corpus callosum of both hemispheres, in patients with PD compared to HC subjects. Moreover, voxel-wise correlation analysis revealed that the BAI scores for patients with PD were positively correlated with their FA values for regions showing group differences in the FA of frontal WM of both hemispheres. Altered integrity in frontal WM of patients with PD without comorbid conditions might represent the structural pathophysiology in these patients, and these changes could be related to clinical symptoms of PD.

  14. 75 FR 49524 - In the Matter of Certain Integrated Circuits, Chipsets, and Products Containing Same Including...

    Science.gov (United States)

    2010-08-13

    ... the United States after importation of certain integrated circuits, chipsets, and products containing... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-709] In the Matter of Certain Integrated Circuits, Chipsets, and Products Containing Same Including Televisions, Media Players, and Cameras; Notice...

  15. 76 FR 34101 - In the Matter of Certain Integrated Circuits, Chipsets, and Products Containing Same Including...

    Science.gov (United States)

    2011-06-10

    ... within the United States after importation of certain integrated circuits, chipsets, and products... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-709] In the Matter of Certain Integrated Circuits, Chipsets, and Products Containing Same Including Televisions, Media Players, and Cameras; Notice...

  16. 75 FR 65654 - In the Matter of: Certain Integrated Circuits, Chipsets, and Products Containing Same Including...

    Science.gov (United States)

    2010-10-26

    ... within the United States after importation of certain integrated circuits, chipsets, and products... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-709] In the Matter of: Certain Integrated Circuits, Chipsets, and Products Containing Same Including Televisions, Media Players, and Cameras; Notice...

  17. Abnormal white matter integrity as a structural endophenotype for bipolar disorder.

    Science.gov (United States)

    Sarıçiçek, A; Zorlu, N; Yalın, N; Hıdıroğlu, C; Çavuşoğlu, B; Ceylan, D; Ada, E; Tunca, Z; Özerdem, A

    2016-05-01

    Several lines of evidence suggest that bipolar disorder (BD) is associated with white matter (WM) pathology. Investigation of unaffected first-degree relatives of BD patients may help to distinguish structural biomarkers of genetic risk without the confounding effects of burden of illness, medication or clinical state. In the present study, we applied tract-based spatial statistics to study WM changes in patients with BD, unaffected siblings and controls. A total of 27 euthymic patients with BD type I, 20 unaffected siblings of bipolar patients and 29 healthy controls who did not have any current or past diagnosis of Axis I psychiatric disorders were enrolled in the study. Fractional anisotropy (FA) was significantly lower in BD patients than in the control group in the corpus callosum, fornix, bilateral superior longitudinal fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, anterior thalamic radiation, posterior thalamic radiation, cingulum, uncinate fasciculus, superior corona radiata, anterior corona radiata and left external capsule. In region-of-interest (ROI) analyses, we found that both unaffected siblings and bipolar patients had significantly reduced FA in the left posterior thalamic radiation, the left sagittal stratum, and the fornix compared with healthy controls. Average FA for unaffected siblings was intermediate between the healthy controls and bipolar patients within these ROIs. Decreased FA in the fornix, left posterior thalamic radiation and left sagittal stratum in both bipolar patients and unaffected siblings may represent a potential structural endophenotype or a trait-based marker for BD.

  18. MRI markers for mild cognitive impairment: comparisons between white matter integrity and gray matter volume measurements.

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    Full Text Available The aim of the study was to evaluate the value of assessing white matter integrity using diffusion tensor imaging (DTI for classification of mild cognitive impairment (MCI and prediction of cognitive impairments in comparison to brain atrophy measurements using structural MRI. Fifty-one patients with MCI and 66 cognitive normal controls (CN underwent DTI and T1-weighted structural MRI. DTI measures included fractional anisotropy (FA and radial diffusivity (DR from 20 predetermined regions-of-interest (ROIs in the commissural, limbic and association tracts, which are thought to be involved in Alzheimer's disease; measures of regional gray matter (GM volume included 21 ROIs in medial temporal lobe, parietal cortex, and subcortical regions. Significant group differences between MCI and CN were detected by each MRI modality: In particular, reduced FA was found in splenium, left isthmus cingulum and fornix; increased DR was found in splenium, left isthmus cingulum and bilateral uncinate fasciculi; reduced GM volume was found in bilateral hippocampi, left entorhinal cortex, right amygdala and bilateral thalamus; and thinner cortex was found in the left entorhinal cortex. Group classifications based on FA or DR was significant and better than classifications based on GM volume. Using either DR or FA together with GM volume improved classification accuracy. Furthermore, all three measures, FA, DR and GM volume were similarly accurate in predicting cognitive performance in MCI patients. Taken together, the results imply that DTI measures are as accurate as measures of GM volume in detecting brain alterations that are associated with cognitive impairment. Furthermore, a combination of DTI and structural MRI measurements improves classification accuracy.

  19. Impaired class switch recombination (CSR) in Waldenstrom macroglobulinemia (WM) despite apparently normal CSR machinery.

    Science.gov (United States)

    Kriangkum, Jitra; Taylor, Brian J; Strachan, Erin; Mant, Michael J; Reiman, Tony; Belch, Andrew R; Pilarski, Linda M

    2006-04-01

    Analysis of clonotypic isotype class switching (CSR) in Waldenström macroglobulinemia (WM) and IgM monoclonal gammopathy of undetermined significance (MGUS) reveals a normal initial phase of B-cell activation as determined by constitutive and inducible expression of activation-induced cytidine deaminase (AID). Switch mu (Smu) analysis shows that large deletions are not common in WM or IgM MGUS. In CD40L/IL-4-stimulated WM cultures from 2 patients, we observed clonotypic IgG exhibiting intraclonal homogeneity associated with multiple hybrid Smu/Sgamma junctions. This suggests CSR had occurred within WM cells. Nevertheless, the estimated IgG/IgM-cell frequency was relatively low (1/1600 cells). Thus, for the majority of WM B cells, CSR does not occur even when stimulated in vitro, suggesting that the WM cell is constitutively unable to or being prevented from carrying out CSR. In contrast to WM, the majority of IgM MGUS clones exhibit intraclonal heterogeneity of IgH VDJ. Furthermore, most IgM MGUS accumulate more mutations in the upstream Smu region than do WM, making them unlikely WM progenitors. These observations suggest that switch sequence analysis may identify the subset of patients with IgM MGUS who are at risk of progression to WM.

  20. Permeability-diffusivity modeling vs. fractional anisotropy on white matter integrity assessment and application in schizophrenia.

    Science.gov (United States)

    Kochunov, P; Chiappelli, J; Hong, L E

    2013-01-01

    Diffusion tensor imaging (DTI) assumes a single pool of anisotropically diffusing water to calculate fractional anisotropy (FA) and is commonly used to ascertain white matter (WM) deficits in schizophrenia. At higher b-values, diffusion-signal decay becomes bi-exponential, suggesting the presence of two, unrestricted and restricted, water pools. Theoretical work suggests that semi-permeable cellular membrane rather than the presence of two physical compartments is the cause. The permeability-diffusivity (PD) parameters measured from bi-exponential modeling may offer advantages, over traditional DTI-FA, in identifying WM deficits in schizophrenia. Imaging was performed in N = 26/26 patients/controls (age = 20-61 years, average age = 40.5 ± 12.6). Imaging consisted of fifteen b-shells: b = 250-3800 s/mm(2) with 30 directions/shell, covering seven slices of mid-sagittal corpus callosum (CC) at 1.7 × 1.7 × 4.6 mm. 64-direction DTI was also collected. Permeability-diffusivity-index (PDI), the ratio of restricted to unrestricted apparent diffusion coefficients, and the fraction of unrestricted compartment (Mu) were calculated for CC and cingulate gray matter (GM). FA values for CC were calculated using tract-based-spatial-statistics. Patients had significantly reduced PDI in CC (p ≅ 10(- 4)) and cingulate GM (p = 0.002), while differences in CC FA were modest (p ≅ .03). There was no group-related difference in Mu. Additional theoretical-modeling analysis suggested that reduced PDI in patients may be caused by reduced cross-membrane water molecule exchanges. PDI measurements for cerebral WM and GM yielded more robust patient-control differences than DTI-FA. Theoretical work offers an explanation that patient-control PDI differences should implicate abnormal active membrane permeability. This would implicate abnormal activities in ion-channels that use water as substrate for ion exchange, in cerebral tissues of schizophrenia patients.

  1. White matter integrity in kleptomania: A pilot study

    OpenAIRE

    Grant, Jon E.; Correia, Stephen; Brennan-Krohn, Thea

    2006-01-01

    This study's goal was to examine microstructural organization of frontal white matter in kleptomania. Ten females with DSM-IV kleptomania and 10 female controls underwent diffusion tensor imaging. Inferior frontal white matter was the a priori region of interest. Trace and fractional anisotropy (FA) were also calculated for frontal and posterior cortical regions in both subject groups. Kleptomania subjects had significantly higher mean frontal Trace, and significantly lower mean frontal FA th...

  2. 76 FR 41521 - In the Matter of Certain Integrated Circuits, Chipsets, and Products Containing Same Including...

    Science.gov (United States)

    2011-07-14

    ... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-786] In the Matter of Certain Integrated Circuits... sale within the United States after importation of certain integrated circuits, chipsets, and products... after importation of certain integrated circuits, chipsets, and products containing same including...

  3. 75 FR 16837 - In the Matter of Certain Integrated Circuits, Chipsets, and Products Containing Same Including...

    Science.gov (United States)

    2010-04-02

    ... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-709] In the Matter of Certain Integrated Circuits... importation of certain integrated circuits, chipsets, and products containing same including televisions... importation, or the sale within the United States after importation of certain integrated circuits, chipsets...

  4. Relationship between grey matter integrity and executive abilities in aging.

    Science.gov (United States)

    Manard, Marine; Bahri, Mohamed Ali; Salmon, Eric; Collette, Fabienne

    2016-07-01

    This cross-sectional study was designed to investigate grey matter changes that occur in healthy aging and the relationship between grey matter characteristics and executive functioning. Thirty-six young adults (18-30 years old) and 43 seniors (60-75 years old) were included. A general executive score was derived from a large battery of neuropsychological tests assessing three major aspects of executive functioning (inhibition, updating and shifting). Age-related grey matter changes were investigated by comparing young and older adults using voxel-based morphometry and voxel-based cortical thickness methods. A widespread difference in grey matter volume was found across many brain regions, whereas cortical thinning was mainly restricted to central areas. Multivariate analyses showed age-related changes in relatively similar brain regions to the respective univariate analyses but appeared more limited. Finally, in the older adult sample, a significant relationship between global executive performance and decreased grey matter volume in anterior (i.e. frontal, insular and cingulate cortex) but also some posterior brain areas (i.e. temporal and parietal cortices) as well as subcortical structures was observed. Results of this study highlight the distribution of age-related effects on grey matter volume and show that cortical atrophy does not appear primarily in "frontal" brain regions. From a cognitive viewpoint, age-related executive functioning seems to be related to grey matter volume but not to cortical thickness. Therefore, our results also highlight the influence of methodological aspects (from preprocessing to statistical analysis) on the pattern of results, which could explain the lack of consensus in literature. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. 78 FR 56224 - Hydro Nelson, Ltd.; Hydro-WM, LLC; Notice of Transfer of Exemption

    Science.gov (United States)

    2013-09-12

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 3401-049] Hydro Nelson, Ltd.; Hydro-WM, LLC; Notice of Transfer of Exemption 1. By documentation filed July 8, 2013 and supplemented... Hydro-WM, LLC. The project is located on the Rockfish River in Nelson County, Virginia. The transfer of...

  6. 75 FR 1362 - WM Renewable Energy, L.L.C.; Notice of Filing

    Science.gov (United States)

    2010-01-11

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket Nos. EL10-32-000, QF08-622-002] WM Renewable Energy, L.L.C.; Notice of Filing January 4, 2010. Take notice that on December 31, 2009, WM Renewable Energy, L.L.C. filed a petition for a declaratory order, pursuant to Rule 207(a)(2) of...

  7. 78 FR 57105 - Wm. Wrigley Jr. Company; Filing of Color Additive Petition

    Science.gov (United States)

    2013-09-17

    ... lead in synthetic iron oxide for human food use. DATES: The color additive petition was filed on July.... FDA-2013-C-1008] Wm. Wrigley Jr. Company; Filing of Color Additive Petition AGENCY: Food and Drug... announcing that we have filed a petition, submitted by the Wm. Wrigley Jr. Company, proposing that the color...

  8. Aging of cerebral white matter.

    Science.gov (United States)

    Liu, Huan; Yang, Yuanyuan; Xia, Yuguo; Zhu, Wen; Leak, Rehana K; Wei, Zhishuo; Wang, Jianyi; Hu, Xiaoming

    2017-03-01

    White matter (WM) occupies a large volume of the human cerebrum and is mainly composed of myelinated axons and myelin-producing glial cells. The myelinated axons within WM are the structural foundation for efficient neurotransmission between cortical and subcortical areas. Similar to neuron-enriched gray matter areas, WM undergoes a series of changes during the process of aging. WM malfunction can induce serious neurobehavioral and cognitive impairments. Thus, age-related changes in WM may contribute to the functional decline observed in the elderly. In addition, aged WM becomes more susceptible to neurological disorders, such as stroke, traumatic brain injury (TBI), and neurodegeneration. In this review, we summarize the structural and functional alterations of WM in natural aging and speculate on the underlying mechanisms. We also discuss how age-related WM changes influence the progression of various brain disorders, including ischemic and hemorrhagic stroke, TBI, Alzheimer's disease, and Parkinson's disease. Although the physiology of WM is still poorly understood relative to gray matter, WM is a rational therapeutic target for a number of neurological and psychiatric conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Age-related Differences in White Matter Integrity in Healthy Human Brain: Evidence from Structural Mri and Diffusion Tensor Imaging

    Directory of Open Access Journals (Sweden)

    Rishu Rathee

    2016-01-01

    Full Text Available The aim is to investigate the relationship between microstructural white matter (WM diffusivity indices and macrostructural WM volume (WMV among healthy individuals (20–85 years. Whole-brain diffusion measures were calculated from diffusion tensor imaging using FMRIB software library while WMV was estimated through voxel-based morphometry, and voxel-based analysis was carried out using tract-based spatial statistics. Our results revealed that mean diffusivity, axial diffusivity, and radial diffusivity had shown good correlation with WMV but not for fractional anisotropy (FA. Voxel-wise tract-based spatial statistics analysis for FA showed a significant decrease in four regions for middle-aged group compared to young-aged group, in 22 regions for old-aged group compared to middle-aged group, and in 26 regions for old-aged group compared to young-aged group ( P < 0.05. We found significantly lower WMV, FA, and mean diffusivity values in females than males and inverted-U trend for FA in males. We conclude differential age- and gender-related changes for structural WMV and WM diffusion indices.

  10. White matter integrity as a predictor of response to treatment in first episode psychosis.

    Science.gov (United States)

    Reis Marques, Tiago; Taylor, Heather; Chaddock, Chris; Dell'acqua, Flavio; Handley, Rowena; Reinders, A A T Simone; Mondelli, Valeria; Bonaccorso, Stefania; Diforti, Marta; Simmons, Andrew; David, Anthony S; Murray, Robin M; Pariante, Carmine M; Kapur, Shitij; Dazzan, Paola

    2014-01-01

    The integrity of brain white matter connections is central to a patient's ability to respond to pharmacological interventions. This study tested this hypothesis using a specific measure of white matter integrity, and examining its relationship to treatment response using a prospective design in patients within their first episode of psychosis. Diffusion tensor imaging data were acquired in 63 patients with first episode psychosis and 52 healthy control subjects (baseline). Response was assessed after 12 weeks and patients were classified as responders or non-responders according to treatment outcome. At this second time-point, they also underwent a second diffusion tensor imaging scan. Tract-based spatial statistics were used to assess fractional anisotropy as a marker of white matter integrity. At baseline, non-responders showed lower fractional anisotropy than both responders and healthy control subjects (P psychosis. These data, together with earlier findings on cortical grey matter, suggest that grey and white matter integrity at the start of treatment is an important moderator of response to antipsychotics. These findings can inform patient stratification to anticipate care needs, and raise the possibility that antipsychotics may restore white matter integrity as part of the therapeutic response.

  11. Widespread reductions of white matter integrity in patients with long-term remission of Cushing's disease

    Directory of Open Access Journals (Sweden)

    Steven J.A. van der Werff

    2014-01-01

    Conclusion: Patients with a history of endogenous hypercortisolism in present remission show widespread changes of white matter integrity in the brain, with abnormalities in the integrity of the uncinate fasciculus being related to the severity of depressive symptoms, suggesting persistent structural effects of hypercortisolism.

  12. Organisational Culture Matters for System Integration in Health Care

    Science.gov (United States)

    Munir, Samina K.; Kay, Stephen

    2003-01-01

    This paper illustrates the importance of organisational culture for Clinical Information Systems (CIS) integration. The study is based on data collected in intensive care units in the UK and Denmark. Data were collected using qualitative methods, i.e., observations, interviews and shadowing of health care providers, together with a questionnaire at each site. The data are analysed to extract salient variables for CIS integration, and it is shown that these variables can be separated into two categories that describe the ‘Actual Usefulness’ of the system and the ‘Organisational Culture’. This model is then extended to show that CIS integration directly affects the work processes of the organisation, forming an iterative process of change as a CIS is introduced and integrated. PMID:14728220

  13. Milestones of European Integration: Which matters most for Export Openness?

    DEFF Research Database (Denmark)

    Hiller, Sanne; Kruse, Robinson

    The European integration process has removed barriers to trade within Europe. We analyze which integration step has most profoundly influenced the trending behavior of export openness. We endogenously determine the single most decisive break in the trend, account for strong cross-country heteroge......The European integration process has removed barriers to trade within Europe. We analyze which integration step has most profoundly influenced the trending behavior of export openness. We endogenously determine the single most decisive break in the trend, account for strong cross...... and the Netherlands are the Euro introduction, the Maastricht Treaty, the Exchange Rate Mechanism I and the merge of EFTA and EEC to the European Economic Area, respectively. Our empirical results have important implications for inner-European economic development, as export openness feeds back into growth...

  14. White matter hyperintensities and changes in white matter integrity in patients with Alzheimer's disease

    International Nuclear Information System (INIS)

    Wang, Liya; Mao, Hui; Goldstein, Felicia C.; Levey, Allan I.; Lah, James J.; Meltzer, Carolyn C.; Holder, Chad A.

    2011-01-01

    White matter hyperintensities (WMHs) are a risk factor for Alzheimer's disease (AD). This study investigated the relationship between WMHs and white matter changes in AD using diffusion tensor imaging (DTI) and the sensitivity of each DTI index in distinguishing AD with WMHs. Forty-four subjects with WMHs were included. Subjects were classified into three groups based on the Scheltens rating scale: 15 AD patients with mild WMHs, 12 AD patients with severe WMHs, and 17 controls with mild WMHs. Fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (D R ), and axial diffusivity (D A ) were analyzed using the region of interest and tract-based spatial statistics methods. Sensitivity and specificity of DTI indices in distinguishing AD groups from the controls were evaluated. AD patients with mild WMHs exhibited differences from control subjects in most DTI indices in the medial temporal and frontal areas; however, differences in DTI indices from AD patients with mild WMHs and AD patients with severe WMHs were found in the parietal and occipital areas. FA and D R were more sensitive measurements than MD and D A in differentiating AD patients from controls, while MD was a more sensitive measurement in distinguishing AD patients with severe WMHs from those with mild WMHs. WMHs may contribute to the white matter changes in AD brains, specifically in temporal and frontal areas. Changes in parietal and occipital lobes may be related to the severity of WMHs. D R may serve as an imaging marker of myelin deficits associated with AD. (orig.)

  15. Episodic memory function is associated with multiple measures of white matter integrity in cognitive aging

    Directory of Open Access Journals (Sweden)

    Samuel Neal Lockhart

    2012-03-01

    Full Text Available Previous neuroimaging research indicates that white matter injury and integrity, measured respectively by white matter hyperintensities (WMH and fractional anisotropy (FA obtained from diffusion tensor imaging, differ with aging and cerebrovascular disease and are associated with episodic memory deficits in cognitively normal older adults. However, knowledge about tract-specific relationships between WMH, FA, and episodic memory in aging remains limited. We hypothesized that white matter connections between frontal cortex and subcortical structures as well as connections between frontal and temporo-parietal cortex would be most affected. In the current study, we examined relationships between WMH, FA and episodic memory in 15 young adults, 13 elders with minimal WMH and 15 elders with extensive WMH, using an episodic recognition memory test for object-color associations. Voxel-based statistics were used to identify voxel clusters where white matter measures were specifically associated with variations in episodic memory performance, and white matter tracts intersecting these clusters were analyzed to examine white matter-memory relationships. White matter injury and integrity measures were significantly associated with episodic memory in extensive regions of white matter, located predominantly in frontal, parietal, and subcortical regions. Template based tractography indicated that white matter injury, as measured by WMH, in the uncinate and inferior longitudinal fasciculi were significantly negatively associated with episodic memory performance. Other tracts such as thalamo-frontal projections, superior longitudinal fasciculus, and dorsal cingulum bundle demonstrated strong negative associations as well. The results suggest that white matter injury to multiple pathways, including connections of frontal and temporal cortex and frontal-subcortical white matter tracts, plays a critical role in memory differences seen in older individuals.

  16. Structures and electronic properties of WmCun (n + m ≤ 7) clusters

    Indian Academy of Sciences (India)

    MS received 2 May 2017; accepted 12 June 2017; published online 29 March 2018 ... ing technology by Dong [30], revealing that graphene reacts ..... Size dependence of binding energies per atom for the lowest energy structures of WmCun ...

  17. White Matter Integrity Deficit Associated with Betel Quid Dependence

    Directory of Open Access Journals (Sweden)

    Fulai Yuan

    2017-10-01

    Full Text Available Betel quid (BQ is a commonly consumed psychoactive substance, which has been regarded as a human carcinogen. Long-term BQ chewing may cause Diagnostic and Statistical Manual of Mental Disorders-IV dependence symptoms, which can lead to decreased cognitive functions, such as attention and inhibition control. Although betel quid dependence (BQD individuals have been reported with altered brain structure and function, there is little evidence showing white matter microstructure alternation in BQD individuals. The present study aimed to investigate altered white matter microstructure in BQD individuals using diffusion tensor imaging. Tract-based spatial statistics was used to analyze the data. Compared with healthy controls, BQD individuals exhibited higher mean diffusivity (MD in anterior thalamic radiation (ATR. Further analysis revealed that the ATR in BQD individuals showed less fractional anisotropy (FA than that in healthy controls. Correlation analysis showed that both the increase of MD and reduction of FA in BQD individuals were associated with severity of BQ dependence. These results suggested that BQD would disrupt the balance between prefrontal cortex and subcortical areas, causing declined inhibition control.

  18. White Matter Integrity Deficit Associated with Betel Quid Dependence.

    Science.gov (United States)

    Yuan, Fulai; Zhu, Xueling; Kong, Lingyu; Shen, Huaizhen; Liao, Weihua; Jiang, Canhua

    2017-01-01

    Betel quid (BQ) is a commonly consumed psychoactive substance, which has been regarded as a human carcinogen. Long-term BQ chewing may cause Diagnostic and Statistical Manual of Mental Disorders-IV dependence symptoms, which can lead to decreased cognitive functions, such as attention and inhibition control. Although betel quid dependence (BQD) individuals have been reported with altered brain structure and function, there is little evidence showing white matter microstructure alternation in BQD individuals. The present study aimed to investigate altered white matter microstructure in BQD individuals using diffusion tensor imaging. Tract-based spatial statistics was used to analyze the data. Compared with healthy controls, BQD individuals exhibited higher mean diffusivity (MD) in anterior thalamic radiation (ATR). Further analysis revealed that the ATR in BQD individuals showed less fractional anisotropy (FA) than that in healthy controls. Correlation analysis showed that both the increase of MD and reduction of FA in BQD individuals were associated with severity of BQ dependence. These results suggested that BQD would disrupt the balance between prefrontal cortex and subcortical areas, causing declined inhibition control.

  19. Effects of bilingualism on white matter integrity in older adults.

    Science.gov (United States)

    Anderson, John A E; Grundy, John G; De Frutos, Jaisalmer; Barker, Ryan M; Grady, Cheryl; Bialystok, Ellen

    2018-02-15

    Bilingualism can delay the onset of dementia symptoms and has thus been characterized as a mechanism for cognitive or brain reserve, although the origin of this reserve is unknown. Studies with young adults generally show that bilingualism is associated with a strengthening of white matter, but there is conflicting evidence for how bilingualism affects white matter in older age. Given that bilingualism has been shown to help stave off the symptoms of dementia by up to four years, it is crucial that we clarify the mechanism underlying this reserve. The current study uses diffusion tensor imaging (DTI) to compare monolinguals and bilinguals while carefully controlling for potential confounds (e.g., I.Q., MMSE, and demographic variables). We show that group differences in Fractional Anisotropy (FA) and Radial Diffusivity (RD) arise from multivariable interactions not adequately controlled for by sequential bivariate testing. After matching and statistically controlling for confounds, bilinguals still had greater axial diffusivity (AD) in the left superior longitudinal fasciculus than monolingual peers, supporting a neural reserve account for healthy older bilinguals. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Aortic stiffness is associated with white matter integrity in patients with type 1 diabetes

    International Nuclear Information System (INIS)

    Tjeerdema, Nathanja; Schinkel, Linda D. van; Westenberg, Jos J.; Elderen, Saskia G. van; Buchem, Mark A. van; Grond, Jeroen van der; Roos, Albert de; Smit, Johannes W.

    2014-01-01

    To assess the association between aortic pulse wave velocity (PWV) as a marker of arterial stiffness and diffusion tensor imaging of brain white matter integrity in patients with type 1 diabetes using advanced magnetic resonance imaging (MRI) technology. Forty-one patients with type 1 diabetes (23 men, mean age 44 ± 12 years, mean diabetes duration 24 ± 13 years) were included. Aortic PWV was assessed using through-plane velocity-encoded MRI. Brain diffusion tensor imaging (DTI) measurements were performed on 3-T MRI. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were calculated for white and grey matter integrity. Pearson correlation and multivariable linear regression analyses including cardiovascular risk factors as covariates were assessed. Multivariable linear regression analyses revealed that aortic PWV is independently associated with white matter integrity FA (β = -0.777, p = 0.008) in patients with type 1 diabetes. This effect was independent of age, gender, mean arterial pressure, body mass index, smoking, duration of diabetes and glycated haemoglobin levels. Aortic PWV was not significantly related to grey matter integrity. Our data suggest that aortic stiffness is independently associated with reduced white matter integrity in patients with type 1 diabetes. (orig.)

  1. Aortic stiffness is associated with white matter integrity in patients with type 1 diabetes

    Energy Technology Data Exchange (ETDEWEB)

    Tjeerdema, Nathanja; Schinkel, Linda D. van [Leiden University Medical Center, Department of Endocrinology and General Internal Medicine (C7-Q), Albinusdreef 2, PO Box 9600, Leiden (Netherlands); Westenberg, Jos J.; Elderen, Saskia G. van; Buchem, Mark A. van; Grond, Jeroen van der; Roos, Albert de [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Smit, Johannes W. [Leiden University Medical Center, Department of Endocrinology and General Internal Medicine (C7-Q), Albinusdreef 2, PO Box 9600, Leiden (Netherlands); University Medical Center Nijmegen, Department of General Internal Medicine, Nijmegen (Netherlands)

    2014-09-15

    To assess the association between aortic pulse wave velocity (PWV) as a marker of arterial stiffness and diffusion tensor imaging of brain white matter integrity in patients with type 1 diabetes using advanced magnetic resonance imaging (MRI) technology. Forty-one patients with type 1 diabetes (23 men, mean age 44 ± 12 years, mean diabetes duration 24 ± 13 years) were included. Aortic PWV was assessed using through-plane velocity-encoded MRI. Brain diffusion tensor imaging (DTI) measurements were performed on 3-T MRI. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were calculated for white and grey matter integrity. Pearson correlation and multivariable linear regression analyses including cardiovascular risk factors as covariates were assessed. Multivariable linear regression analyses revealed that aortic PWV is independently associated with white matter integrity FA (β = -0.777, p = 0.008) in patients with type 1 diabetes. This effect was independent of age, gender, mean arterial pressure, body mass index, smoking, duration of diabetes and glycated haemoglobin levels. Aortic PWV was not significantly related to grey matter integrity. Our data suggest that aortic stiffness is independently associated with reduced white matter integrity in patients with type 1 diabetes. (orig.)

  2. Quantifying the association between white matter integrity changes and subconcussive head impact exposure from a single season of youth and high school football using 3D convolutional neural networks

    Science.gov (United States)

    Saghafi, Behrouz; Murugesan, Gowtham; Davenport, Elizabeth; Wagner, Ben; Urban, Jillian; Kelley, Mireille; Jones, Derek; Powers, Alexander; Whitlow, Christopher; Stitzel, Joel; Maldjian, Joseph; Montillo, Albert

    2018-02-01

    The effect of subconcussive head impact exposure during contact sports, including American football, on brain health is poorly understood particularly in young and adolescent players, who may be more vulnerable to brain injury during periods of rapid brain maturation. This study aims to quantify the association between cumulative effects of head impact exposure from a single season of football on white matter (WM) integrity as measured with diffusion MRI. The study targets football players aged 9-18 years old. All players were imaged pre- and post-season with structural MRI and diffusion tensor MRI (DTI). Fractional Anisotropy (FA) maps, shown to be closely correlated with WM integrity, were computed for each subject, co-registered and subtracted to compute the change in FA per subject. Biomechanical metrics were collected at every practice and game using helmet mounted accelerometers. Each head impact was converted into a risk of concussion, and the risk of concussion-weighted cumulative exposure (RWE) was computed for each player for the season. Athletes with high and low RWE were selected for a two-category classification task. This task was addressed by developing a 3D Convolutional Neural Network (CNN) to automatically classify players into high and low impact exposure groups from the change in FA maps. Using the proposed model, high classification performance, including ROC Area Under Curve score of 85.71% and F1 score of 83.33% was achieved. This work adds to the growing body of evidence for the presence of detectable neuroimaging brain changes in white matter integrity from a single season of contact sports play, even in the absence of a clinically diagnosed concussion.

  3. White matter integrity deficits in prefrontal-amygdala pathways in Williams syndrome.

    Science.gov (United States)

    Avery, Suzanne N; Thornton-Wells, Tricia A; Anderson, Adam W; Blackford, Jennifer Urbano

    2012-01-16

    Williams syndrome is a neurodevelopmental disorder associated with significant non-social fears. Consistent with this elevated non-social fear, individuals with Williams syndrome have an abnormally elevated amygdala response when viewing threatening non-social stimuli. In typically-developing individuals, amygdala activity is inhibited through dense, reciprocal white matter connections with the prefrontal cortex. Neuroimaging studies suggest a functional uncoupling of normal prefrontal-amygdala inhibition in individuals with Williams syndrome, which might underlie both the extreme amygdala activity and non-social fears. This functional uncoupling might be caused by structural deficits in underlying white matter pathways; however, prefrontal-amygdala white matter deficits have yet to be explored in Williams syndrome. We used diffusion tensor imaging to investigate prefrontal-amygdala white matter integrity differences in individuals with Williams syndrome and typically-developing controls with high levels of non-social fear. White matter pathways between the amygdala and several prefrontal regions were isolated using probabilistic tractography. Within each pathway, we tested for between-group differences in three measures of white matter integrity: fractional anisotropy (FA), radial diffusivity (RD), and parallel diffusivity (λ(1)). Individuals with Williams syndrome had lower FA, compared to controls, in several of the prefrontal-amygdala pathways investigated, indicating a reduction in white matter integrity. Lower FA in Williams syndrome was explained by significantly higher RD, with no differences in λ(1), suggestive of lower fiber density or axon myelination in prefrontal-amygdala pathways. These results suggest that deficits in the structural integrity of prefrontal-amygdala white matter pathways might underlie the increased amygdala activity and extreme non-social fears observed in Williams syndrome. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Integrating Condensed Matter Physics into a Liberal Arts Physics Curriculum

    Science.gov (United States)

    Collett, Jeffrey

    2008-03-01

    The emergence of nanoscale science into the popular consciousness presents an opportunity to attract and retain future condensed matter scientists. We inject nanoscale physics into recruiting activities and into the introductory and the core portions of the curriculum. Laboratory involvement and research opportunity play important roles in maintaining student engagement. We use inexpensive scanning tunneling (STM) and atomic force (AFM) microscopes to introduce students to nanoscale structure early in their college careers. Although the physics of tip-surface interactions is sophisticated, the resulting images can be interpreted intuitively. We use the STM in introductory modern physics to explore quantum tunneling and the properties of electrons at surfaces. An interdisciplinary course in nanoscience and nanotechnology course team-taught with chemists looks at nanoscale phenomena in physics, chemistry, and biology. Core quantum and statistical physics courses look at effects of quantum mechanics and quantum statistics in degenerate systems. An upper level solid-state physics course takes up traditional condensed matter topics from a structural perspective by beginning with a study of both elastic and inelastic scattering of x-rays from crystalline solids and liquid crystals. Students encounter reciprocal space concepts through the analysis of laboratory scattering data and by the development of the scattering theory. The course then examines the importance of scattering processes in band structure and in electrical and thermal conduction. A segment of the course is devoted to surface physics and nanostructures where we explore the effects of restricting particles to two-dimensional surfaces, one-dimensional wires, and zero-dimensional quantum dots.

  5. Cigarette smoking is associated with reduced microstructural integrity of cerebral white matter.

    Science.gov (United States)

    Gons, Rob A R; van Norden, Anouk G W; de Laat, Karlijn F; van Oudheusden, Lucas J B; van Uden, Inge W M; Zwiers, Marcel P; Norris, David G; de Leeuw, Frank-Erik

    2011-07-01

    Cigarette smoking doubles the risk of dementia and Alzheimer's disease. Various pathophysiological pathways have been proposed to cause such a cognitive decline, but the exact mechanisms remain unclear. Smoking may affect the microstructural integrity of cerebral white matter. Diffusion tensor imaging is known to be sensitive for microstructural changes in cerebral white matter. We therefore cross-sectionally studied the relation between smoking behaviour (never, former, current) and diffusion tensor imaging parameters in both normal-appearing white matter and white matter lesions as well as the relation between smoking behaviour and cognitive performance. A structured questionnaire was used to ascertain the amount and duration of smoking in 503 subjects with small-vessel disease, aged between 50 and 85 years. Cognitive function was assessed with a neuropsychological test battery. All subjects underwent 1.5 Tesla magnetic resonance imaging. Using diffusion tensor imaging, fractional anisotropy and mean diffusivity were calculated in both normal-appearing white matter and white matter lesions. A history of smoking was associated with significant higher values of mean diffusivity in normal-appearing white matter and white matter lesions (P-trend for smoking status = 0.02) and with poorer cognitive functioning compared with those who never smoked. Associations with smoking and loss of structural integrity appeared to be strongest in normal-appearing white matter. Furthermore, the duration of smoking cessation was positively related to lower values of mean diffusivity and higher values of fractional anisotropy in normal-appearing white matter [β = -0.004 (95% confidence interval -0.007 to 0.000; P = 0.03) and β = 0.019 (95% confidence interval 0.001-0.038; P = 0.04)]. Fractional anisotropy and mean diffusivity values in normal-appearing white matter of subjects who had quit smoking for >20 years were comparable with subjects who had never smoked. These data suggest

  6. Mapping White Matter Integrity and Neurobehavioral Correlates in Children with Fetal Alcohol Spectrum Disorders

    Science.gov (United States)

    Sowell, Elizabeth R.; Johnson, Arianne; Kan, Eric; Lu, Lisa H.; Van Horn, John Darrell; Toga, Arthur W.; O’Connor, Mary J.; Bookheimer, Susan Y.

    2013-01-01

    Brain structural abnormalities and neurocognitive dysfunction have been observed in individuals with fetal alcohol spectrum disorders (FASDs). Little is known about how white matter integrity is related to these functional and morphological deficits. We used a combination of diffusion tensor and T1-weighted magnetic resonance imaging to evaluate white matter integrity in individuals with FASDs and related these findings to neurocognitive deficits. Seventeen children and adolescents with FASDs were compared with 19 typically developing age-and gender-matched controls. Lower fractional anisotropy (FA) was observed in individuals with FASDs relative to controls in the right lateral temporal lobe and bilaterally in the lateral aspects of the splenium of the corpus callosum. White matter density was also lower in some, but not all regions in which FA was lower. FA abnormalities were confirmed to be in areas of white matter in post hoc region of interest analyses, further supporting that less myelin or disorganized fiber tracts are associated with heavy prenatal alcohol exposure. Significant correlations between performance on a test of visuomotor integration and FA in bilateral splenium, but not temporal regions were observed within the FASD group. Correlations between the visuomotor task and FA within the splenium were not significant with in the control group, and were not significant for measures of reading ability. This suggests that this region of white matter is particularly susceptible to damage from prenatal alcohol exposure and that disruption of splenial fibers in this group is associated with poorer visuomotor integration. PMID:18256251

  7. Testing the hypothesis of accelerated cerebral white matter aging in schizophrenia and major depression.

    Science.gov (United States)

    Kochunov, Peter; Glahn, David C; Rowland, Laura M; Olvera, Rene L; Winkler, Anderson; Yang, Yi-Hong; Sampath, Hemalatha; Carpenter, Will T; Duggirala, Ravindranath; Curran, Joanne; Blangero, John; Hong, L Elliot

    2013-03-01

    Elevated rate of aging-related biological and functional decline, termed "accelerated aging," is reported in patients with schizophrenia (SCZ) and major depressive disorder (MDD). We used diffusion tensor imaging derived fractional anisotropy (FA) as a biomarker of aging-related decline in white matter (WM) integrity to test the hypotheses of accelerated aging in SCZ and MDD. The SCZ cohort comprised 58 SCZ patients and 60 controls (aged 20-60 years). The MDD cohort comprised 136 MDD patients and 351 controls (aged 20-79 years). The main outcome measures were the diagnosis-by-age interaction on whole-brain-averaged WM FA values and FA values from 12 major WM tracts. Diagnosis-by-age interaction for the whole-brain average FA was significant for the SCZ (p = .04) but not the MDD (p = .80) cohort. Diagnosis-by-age interaction was nominally significant (paccelerated aging in SCZ but not in MDD, suggesting some difference in the pathophysiology underlying their WM aging changes. Tract-specific heterochronicity of WM development modulated presentation of accelerated aging in SCZ: WM tracts that matured later in life appeared more sensitive to the pathophysiology of SCZ and demonstrated more susceptibility to disorder-related accelerated decline in FA values with age. This trend was not observed in MDD cohort. Copyright © 2013 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  8. Effects of insulin resistance on white matter microstructure in middle-aged and older adults

    Science.gov (United States)

    Coutu, Jean-Philippe; Rosas, H. Diana; Salat, David H.

    2014-01-01

    Objective: To investigate the potential relationship between insulin resistance (IR) and white matter (WM) microstructure using diffusion tensor imaging in cognitively healthy middle-aged and older adults. Methods: Diffusion tensor imaging was acquired from 127 individuals (age range 41–86 years). IR was evaluated by the homeostasis model assessment of IR (HOMA-IR). Participants were divided into 2 groups based on HOMA-IR values: “high HOMA-IR” (≥2.5, n = 27) and “low HOMA-IR” (HOMA-IR group demonstrated decreased axial diffusivity broadly throughout the cerebral WM in areas such as the corpus callosum, corona radiata, cerebral peduncle, posterior thalamic radiation, and right superior longitudinal fasciculus, and WM underlying the frontal, parietal, and temporal lobes, as well as decreased fractional anisotropy in the body and genu of corpus callosum and parts of the superior and anterior corona radiata, compared with the low HOMA-IR group, independent of age, WM signal abnormality volume, and antihypertensive medication status. These regions additionally demonstrated linear associations between diffusion measures and HOMA-IR across all subjects, with higher HOMA-IR values being correlated with lower axial diffusivity. Conclusions: In generally healthy adults, greater IR is associated with alterations in WM tissue integrity. These cross-sectional findings suggest that IR contributes to WM microstructural alterations in middle-aged and older adults. PMID:24771537

  9. Safe and healthy integration into semiskilled jobs: does gender matter?

    Science.gov (United States)

    Laberge, Marie; Vézina, Nicole; Saint-Charles, Johanne

    2012-01-01

    Women report fewer injuries than men when they are young, but report a higher proportion of professional diseases later in life (35 years +). Understanding early work conditions that lead to postponed health outcomes is necessary if we are to prevent women's injury as well as men's. Introduction to work and safe integration programs are often put forward to prevent injuries among youth. This paper aims to illustrate some differences in the job introduction / integration process for men and women and to discuss some gender-based Occupational Health and Safety (OHS) implications. Data come from two waves of interviews with 31 students enrolled in vocational training for a semiskilled trade. Results demonstrated differences between men and women: trades chosen, OHS complaints, supervising patterns, integration to work, etc. Women often choose customer service jobs, have less formal supervision and are often left to themselves when learning to do their job. Men declared more accidents while women reported more musculoskeletal symptoms. Findings from this research suggest young women's OHS issues should not be trivialized and that specific youth prevention programs for sectors where women are more present, such as customer service, should be developed.

  10. Altered Development of White Matter in Youth at High Familial Risk for Bipolar Disorder: A Diffusion Tensor Imaging Study

    Science.gov (United States)

    Versace, Amelia; Ladouceur, Cecile D.; Romero, Soledad; Birmaher, Boris; Axelson, David A.; Kupfer, David J.; Phillips, Mary L.

    2010-01-01

    Objective: To study white matter (WM) development in youth at high familial risk for bipolar disorder (BD). WM alterations are reported in youth and adults with BD. WM undergoes important maturational changes in adolescence. Age-related changes in WM microstructure using diffusion tensor imaging with tract-based spatial statistics in healthy…

  11. Regional brain gray and white matter changes in perinatally HIV-infected adolescents☆

    Science.gov (United States)

    Sarma, Manoj K.; Nagarajan, Rajakumar; Keller, Margaret A.; Kumar, Rajesh; Nielsen-Saines, Karin; Michalik, David E.; Deville, Jaime; Church, Joseph A.; Thomas, M. Albert

    2013-01-01

    Despite the success of antiretroviral therapy (ART), perinatally infected HIV remains a major health problem worldwide. Although advance neuroimaging studies have investigated structural brain changes in HIV-infected adults, regional gray matter (GM) and white matter (WM) volume changes have not been reported in perinatally HIV-infected adolescents and young adults. In this cross-sectional study, we investigated regional GM and WM changes in 16 HIV-infected youths receiving ART (age 17.0 ± 2.9 years) compared with age-matched 14 healthy controls (age 16.3 ± 2.3 years) using magnetic resonance imaging (MRI)-based high-resolution T1-weighted images with voxel based morphometry (VBM) analyses. White matter atrophy appeared in perinatally HIV-infected youths in brain areas including the bilateral posterior corpus callosum (CC), bilateral external capsule, bilateral ventral temporal WM, mid cerebral peduncles, and basal pons over controls. Gray matter volume increase was observed in HIV-infected youths for several regions including the left superior frontal gyrus, inferior occipital gyrus, gyrus rectus, right mid cingulum, parahippocampal gyrus, bilateral inferior temporal gyrus, and middle temporal gyrus compared with controls. Global WM and GM volumes did not differ significantly between groups. These results indicate WM injury in perinatally HIV-infected youths, but the interpretation of the GM results, which appeared as increased regional volumes, is not clear. Further longitudinal studies are needed to clarify if our results represent active ongoing brain infection or toxicity from HIV treatment resulting in neuronal cell swelling and regional increased GM volume. Our findings suggest that assessment of regional GM and WM volume changes, based on VBM procedures, may be an additional measure to assess brain integrity in HIV-infected youths and to evaluate success of current ART therapy for efficacy in the brain. PMID:24380059

  12. Regional brain gray and white matter changes in perinatally HIV-infected adolescents

    Directory of Open Access Journals (Sweden)

    Manoj K. Sarma

    2014-01-01

    Full Text Available Despite the success of antiretroviral therapy (ART, perinatally infected HIV remains a major health problem worldwide. Although advance neuroimaging studies have investigated structural brain changes in HIV-infected adults, regional gray matter (GM and white matter (WM volume changes have not been reported in perinatally HIV-infected adolescents and young adults. In this cross-sectional study, we investigated regional GM and WM changes in 16 HIV-infected youths receiving ART (age 17.0 ± 2.9 years compared with age-matched 14 healthy controls (age 16.3 ± 2.3 years using magnetic resonance imaging (MRI-based high-resolution T1-weighted images with voxel based morphometry (VBM analyses. White matter atrophy appeared in perinatally HIV-infected youths in brain areas including the bilateral posterior corpus callosum (CC, bilateral external capsule, bilateral ventral temporal WM, mid cerebral peduncles, and basal pons over controls. Gray matter volume increase was observed in HIV-infected youths for several regions including the left superior frontal gyrus, inferior occipital gyrus, gyrus rectus, right mid cingulum, parahippocampal gyrus, bilateral inferior temporal gyrus, and middle temporal gyrus compared with controls. Global WM and GM volumes did not differ significantly between groups. These results indicate WM injury in perinatally HIV-infected youths, but the interpretation of the GM results, which appeared as increased regional volumes, is not clear. Further longitudinal studies are needed to clarify if our results represent active ongoing brain infection or toxicity from HIV treatment resulting in neuronal cell swelling and regional increased GM volume. Our findings suggest that assessment of regional GM and WM volume changes, based on VBM procedures, may be an additional measure to assess brain integrity in HIV-infected youths and to evaluate success of current ART therapy for efficacy in the brain.

  13. Assessing Working Memory in Children: The Comprehensive Assessment Battery for Children - Working Memory (CABC-WM).

    Science.gov (United States)

    Cabbage, Kathryn; Brinkley, Shara; Gray, Shelley; Alt, Mary; Cowan, Nelson; Green, Samuel; Kuo, Trudy; Hogan, Tiffany P

    2017-06-12

    The Comprehensive Assessment Battery for Children - Working Memory (CABC-WM) is a computer-based battery designed to assess different components of working memory in young school-age children. Working memory deficits have been identified in children with language-based learning disabilities, including dyslexia 1 , 2 and language impairment 3 , 4 , but it is not clear whether these children exhibit deficits in subcomponents of working memory, such as visuospatial or phonological working memory. The CABC-WM is administered on a desktop computer with a touchscreen interface and was specifically developed to be engaging and motivating for children. Although the long-term goal of the CABC-WM is to provide individualized working memory profiles in children, the present study focuses on the initial success and utility of the CABC-WM for measuring central executive, visuospatial, phonological loop, and binding constructs in children with typical development. Immediate next steps are to administer the CABC-WM to children with specific language impairment, dyslexia, and comorbid specific language impairment and dyslexia.

  14. White Matter Integrity Pre- and Post Marijuana and Alcohol Initiation in Adolescence

    Directory of Open Access Journals (Sweden)

    Lindsay M. Squeglia

    2013-03-01

    Full Text Available Characterizing the effects of alcohol and marijuana use on adolescent brain development is important for understanding potential alterations in neurodevelopment. Several cross sectional studies have identified group differences in white matter integrity after initiation of heavy alcohol and marijuana use, however none have explored white matter trajectories in adolescents pre- and post initiation of use, particularly for marijuana users. This study followed 16 adolescents with minimal alcohol and marijuana use at ages 16–18 over three years. At follow-up, teens were 19–22 years old; half of the participants initiated heavy alcohol use and half initiated heavy alcohol and marijuana use. Repeated-measures ANOVA revealed 20 clusters in association and projection fibers tracts (p < 0.01 in which a group by time interaction was found. Most consistently, white matter integrity (i.e., fractional anisotropy decreased for those who initiated both heavy alcohol and marijuana use over the follow-up interval. No effect of time or change in white matter integrity was seen for those who initiated alcohol use only in the majority of clusters. In most regions, at the baseline time point, teens who would later initiate both alcohol and marijuana use demonstrated white matter integrity greater than or equal to teens that initiated alcohol use only. Findings suggest poorer tissue integrity associated with combined initiation of heavy alcohol and marijuana use in late adolescence. While pre-existing differences may also be related to likelihood of substance use, the present data suggest an effect on tissue integrity for these teens transitioning to combined alcohol and marijuana use in later adolescence.

  15. White Matter Microstructural Changes Following Quadrato Motor Training: A Longitudinal Study

    Directory of Open Access Journals (Sweden)

    Claudia Piervincenzi

    2017-12-01

    Full Text Available Diffusion tensor imaging (DTI is an important way to characterize white matter (WM microstructural changes. While several cross-sectional DTI studies investigated possible links between mindfulness practices and WM, only few longitudinal investigations focused on the effects of these practices on WM architecture, behavioral change, and the relationship between them. To this aim, in the current study, we chose to conduct an unbiased tract-based spatial statistics (TBSS analysis (n = 35 healthy participants to identify longitudinal changes in WM diffusion parameters following 6 and 12 weeks of daily Quadrato Motor Training (QMT, a whole-body mindful movement practice aimed at improving well-being by enhancing attention, coordination, and creativity. We also investigated the possible relationship between training-induced WM changes and concomitant changes in creativity, self-efficacy, and motivation. Our results indicate that following 6 weeks of daily QMT, there was a bilateral increase of fractional anisotropy (FA in tracts related to sensorimotor and cognitive functions, including the corticospinal tracts, anterior thalamic radiations, and uncinate fasciculi, as well as in the left inferior fronto-occipital, superior and inferior longitudinal fasciculi. Interestingly, significant FA increments were still present after 12 weeks of QMT in most of the above WM tracts, but only in the left hemisphere. FA increase was accompanied by a significant decrease of radial diffusivity (RD, supporting the leading role of myelination processes in training-related FA changes. Finally, significant correlations were found between training-induced diffusion changes and increased self-efficacy as well as creativity. Together, these findings suggest that QMT can improve WM integrity and support the existence of possible relationships between training-related WM microstructural changes and behavioral change.

  16. Financial literacy is associated with white matter integrity in old age.

    Science.gov (United States)

    Han, S Duke; Boyle, Patricia A; Arfanakis, Konstantinos; Fleischman, Debra; Yu, Lei; James, Bryan D; Bennett, David A

    2016-04-15

    Financial literacy, the ability to understand, access, and utilize information in ways that contribute to optimal financial outcomes, is important for independence and wellbeing in old age. We previously reported that financial literacy is associated with greater functional connectivity between brain regions in old age. Here, we tested the hypothesis that higher financial literacy would be associated with greater white matter integrity in old age. Participants included 346 persons without dementia (mean age=81.36, mean education=15.39, male/female=79/267, mean MMSE=28.52) from the Rush Memory and Aging Project. Financial literacy was assessed using a series of questions imbedded as part of an ongoing decision making study. White matter integrity was assessed with diffusion anisotropy measured with diffusion tensor magnetic resonance imaging (DTI). We tested the hypothesis that higher financial literacy is associated with higher diffusion anisotropy in white matter, adjusting for the effects of age, education, sex, and white matter hyperintense lesions. We then repeated the analysis also adjusting for cognitive function. Analyses revealed regions with significant positive associations between financial literacy and diffusion anisotropy, and many remained significant after accounting for cognitive function. White matter tracts connecting right hemisphere temporal-parietal brain regions were particularly implicated. Greater financial literacy is associated with higher diffusion anisotropy in white matter of nondemented older adults after adjusting for important covariates. These results suggest that financial literacy is positively associated with white matter integrity in old age. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Cortisol Reactivity to Stress and Its Association With White Matter Integrity in Adults With Schizophrenia.

    Science.gov (United States)

    Nugent, Katie L; Chiappelli, Joshua; Sampath, Hemalatha; Rowland, Laura M; Thangavelu, Kavita; Davis, Beshaun; Du, Xiaoming; Muellerklein, Florian; Daughters, Stacey; Kochunov, Peter; Hong, L Elliot

    2015-09-01

    Although acute hypothalamic-pituitary-adrenal axis response to stress is often adaptive, prolonged responses may have detrimental effects. Many components of white matter structures are sensitive to prolonged cortisol exposure. We aimed to identify a behavioral laboratory assay for cortisol response related to brain pathophysiology in schizophrenia. We hypothesized that an abnormally prolonged cortisol response to stress may be linked to abnormal white matter integrity in patients with schizophrenia. Acute and prolonged salivary cortisol response was measured outside the scanner at pretest and then at 0, 20, and 40 minutes after a psychological stress task in patients with schizophrenia (n = 45) and controls (n = 53). Tract-averaged white matter was measured by 64-direction diffusion tensor imaging in a subset of patients (n = 30) and controls (n = 33). Patients who did not tolerate the psychological stress task and quit had greater acute (t = 2.52 [p = .016] and t = 3.51 [p = .001] at 0 and 20 minutes) and prolonged (t = 3.62 [p = .001] at 40 minutes) cortisol reactivity compared with patients who finished the task. Abnormally prolonged cortisol reactivity in patients was significantly associated with reduced white matter integrity (r = -0.468, p = .009). Regardless of task completion status, acute cortisol response was not related to the white matter measures in patients or controls. This paradigm was successful at identifying a subset of patients whose cortisol response was associated with brain pathophysiology. Abnormal cortisol response may adversely affect white matter integrity, partly explaining this pathology observed in schizophrenia. Prolonged stress responses may be targeted for intervention to test for protective effects against white matter damages.

  18. White Matter Integrity in Adolescents with Histories of Marijuana Use and Binge Drinking

    OpenAIRE

    Jacobus, J.; McQueeny, T.; Bava, S.; Schweinsburg, B. C.; Frank, L.R.; Yang, T. T.; Tapert, S. F.

    2009-01-01

    Structural brain abnormalities have been observed in adolescents with alcohol use disorders but less is known about neuropathological brain characteristics of teens with subdiagnostic binge drinking or the common pattern of binge drinking combined with marijuana use. The goal of this study was to examine white matter integrity in adolescents with histories of binge drinking and marijuana use.

  19. Foreign exchange market microstructure and the WM/Reuters 4 pm fix

    Directory of Open Access Journals (Sweden)

    P.S. Michelberger

    2016-03-01

    Full Text Available A market fix serves as a benchmark for foreign exchange (FX execution, and is employed by many institutional investors to establish an exact reference at which execution takes place. The currently most popular FX fix is the World Market Reuters (WM/R 4 pm fix. Execution at the WM/R 4 pm fix is a service offered by FX brokers (normally banks, who deliver execution at the fix provided they obtain the trade order ahead of time. In this paper, we study the market microstructure around 4 pm. We demonstrate that market dynamics can be distinguished from other times during the day through increased volatility and size of movements. Our findings question the aggregate benefit to the client base of using the WM/R 4 pm fix in its current form.

  20. Cognitive processing speed in older adults: relationship with white matter integrity.

    Directory of Open Access Journals (Sweden)

    Geoffrey A Kerchner

    Full Text Available Cognitive processing slows with age. We sought to determine the importance of white matter integrity, assessed by diffusion tensor imaging (DTI, at influencing cognitive processing speed among normal older adults, assessed using a novel battery of computerized, non-verbal, choice reaction time tasks. We studied 131 cognitively normal adults aged 55-87 using a cross-sectional design. Each participant underwent our test battery, as well as MRI with DTI. We carried out cross-subject comparisons using tract-based spatial statistics. As expected, reaction time slowed significantly with age. In diffuse areas of frontal and parietal white matter, especially the anterior corpus callosum, fractional anisotropy values correlated negatively with reaction time. The genu and body of the corpus callosum, superior longitudinal fasciculus, and inferior fronto-occipital fasciculus were among the areas most involved. This relationship was not explained by gray or white matter atrophy or by white matter lesion volume. In a statistical mediation analysis, loss of white matter integrity mediated the relationship between age and cognitive processing speed.

  1. Abnormal temporal lobe white matter as a biomarker for genetic risk of bipolar disorder.

    Science.gov (United States)

    Mahon, Katie; Burdick, Katherine E; Ikuta, Toshikazu; Braga, Raphael J; Gruner, Patricia; Malhotra, Anil K; Szeszko, Philip R

    2013-01-15

    Brain white matter (WM) abnormalities have been hypothesized to play an important role in the neurobiology of bipolar disorder (BD). The nature of these abnormalities is not well-characterized, however, and it is unknown whether they occur after disease onset or represent potential markers of genetic risk. We examined WM integrity (assessed via fractional anisotropy [FA]) with diffusion tensor imaging in patients with BD (n=26), unaffected siblings of patients with BD (n=15), and healthy volunteers (n=27) to identify WM biomarkers of genetic risk. The FA differed significantly (punaffected siblings>BD). Moreover, FA values in this region correlated negatively and significantly with trait impulsivity in unaffected siblings. Probabilistic tractography indicated that the regional abnormality lies along the inferior fronto-occipital fasciculus, a large intrahemispheric association pathway. Our results suggest that lower WM integrity in the right temporal lobe might be a biomarker for genetic risk of BD. It is conceivable that the attenuated nature of these WM abnormalities present in unaffected siblings allows for some preservation of adaptive emotional regulation, whereas more pronounced alterations observed in patients is related to the marked emotional dysregulation characteristic of BD. Copyright © 2013 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  2. 76 FR 72025 - Noise Compatibility Program Notice for W.M. Kellogg Airport, Battle Creek, MI

    Science.gov (United States)

    2011-11-21

    ... for W.M. Kellogg Airport, Battle Creek, MI AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... exposure maps submitted by the City of Battle Creek, Michigan for W.K. Kellogg Airport under the provisions... noise compatibility program that was submitted for W.K. Kellogg Airport under part 150 in conjunction...

  3. 85 μm core rod fiber amplifier delivering 350 W/m

    DEFF Research Database (Denmark)

    Johansen, Mette Marie; Michieletto, Mattia; Kristensen, Torben

    2016-01-01

    An improved version of the distributed modal filtering (DMF) rod fiber is tested in a high power setup delivering 350 W/m of extracted signal average power limited by the available pump power. The rod fiber is thoroughly tested to record the transverse modal instability (TMI) behavior and also me...

  4. White matter microstructure in 22q11 deletion syndrome: a pilot diffusion tensor imaging and voxel-based morphometry study of children and adolescents.

    Science.gov (United States)

    Sundram, Frederick; Campbell, Linda E; Azuma, Rayna; Daly, Eileen; Bloemen, Oswald J N; Barker, Gareth J; Chitnis, Xavier; Jones, Derek K; van Amelsvoort, Therese; Murphy, Kieran C; Murphy, Declan G M

    2010-06-01

    Young people with 22q11 Deletion Syndrome (22q11DS) are at substantial risk for developing psychosis and have significant differences in white matter (WM) volume. However, there are few in vivo studies of both WM microstructural integrity (as measured using Diffusion Tensor (DT)-MRI) and WM volume in the same individual. We used DT-MRI and structural MRI (sMRI) with voxel based morphometry (VBM) to compare, respectively, the fractional anisotropy (FA) and WM volume of 11 children and adolescents with 22q11DS and 12 controls. Also, within 22q11DS we related differences in WM to severity of schizotypy, and polymorphism of the catechol-O-methyltransferase (COMT) gene. People with 22q11DS had significantly lower FA in inter-hemispheric and brainstem and frontal, parietal and temporal lobe regions after covarying for IQ. Significant WM volumetric increases were found in the internal capsule, anterior brainstem and frontal and occipital lobes. There was a significant negative correlation between increased schizotypy scores and reduced WM FA in the right posterior limb of internal capsule and the right body and left splenium of corpus callosum. Finally, the Val allele of COMT was associated with a significant reduction in both FA and volume of WM in the frontal lobes, cingulum and corpus callosum. Young people with 22q11DS have significant differences in both WM microstructure and volume. Also, there is preliminary evidence that within 22q11DS, some regional differences in FA are associated with allelic variation in COMT and may perhaps also be associated with schizotypy.

  5. Aerobic fitness is associated with greater white matter integrity in children

    Directory of Open Access Journals (Sweden)

    Laura eChaddock-Heyman

    2014-08-01

    Full Text Available Aerobic fitness has been found to play a positive role in brain and cognitive health of children. Yet, many of the neural biomarkers related to aerobic fitness remain unknown. Here, using diffusion tensor imaging (DTI, we demonstrated that higher aerobic fitness was related to greater estimates of white matter microstructure in children. Higher fit 9- and 10-year-old children showed greater fractional anisotropy (FA in sections of the corpus callosum, corona radiata, and superior longitudinal fasciculus, compared to lower fit children. The FA effects were primarily characterized by aerobic fitness differences in radial diffusivity (RD, thereby raising the possibility that estimates of myelination may vary as a function of individual differences in fitness during childhood. White matter structure may be another potential neural mechanism of aerobic fitness that assists in efficient communication between gray matter regions as well as the integration of regions into networks.

  6. Obesity gene NEGR1 associated with white matter integrity in healthy young adults.

    Science.gov (United States)

    Dennis, Emily L; Jahanshad, Neda; Braskie, Meredith N; Warstadt, Nicholus M; Hibar, Derrek P; Kohannim, Omid; Nir, Talia M; McMahon, Katie L; de Zubicaray, Greig I; Montgomery, Grant W; Martin, Nicholas G; Toga, Arthur W; Wright, Margaret J; Thompson, Paul M

    2014-11-15

    Obesity is a crucial public health issue in developed countries, with implications for cardiovascular and brain health as we age. A number of commonly-carried genetic variants are associated with obesity. Here we aim to see whether variants in obesity-associated genes--NEGR1, FTO, MTCH2, MC4R, LRRN6C, MAP2K5, FAIM2, SEC16B, ETV5, BDNF-AS, ATXN2L, ATP2A1, KCTD15, and TNN13K--are associated with white matter microstructural properties, assessed by high angular resolution diffusion imaging (HARDI) in young healthy adults between 20 and 30 years of age from the Queensland Twin Imaging study (QTIM). We began with a multi-locus approach testing how a number of common genetic risk factors for obesity at the single nucleotide polymorphism (SNP) level may jointly influence white matter integrity throughout the brain and found a wide spread genetic effect. Risk allele rs2815752 in NEGR1 was most associated with lower white matter integrity across a substantial portion of the brain. Across the area of significance in the bilateral posterior corona radiata, each additional copy of the risk allele was associated with a 2.2% lower average FA. This is the first study to find an association between an obesity risk gene and differences in white matter integrity. As our subjects were young and healthy, our results suggest that NEGR1 has effects on brain structure independent of its effect on obesity. Copyright © 2014. Published by Elsevier Inc.

  7. Diffusion tensor MR imaging of white matter integrity in HIV-positive patients with planning deficit

    International Nuclear Information System (INIS)

    Correa, Diogo Goulart; Doring, Thomas M.; Wilner, Nina Ventura; Cabral, Rafael Ferracini; Gasparetto, Emerson Leandro; Zimmermann, Nicolle; Fonseca, Rochele Paz; Leite, Sarah C.B.; Bahia, Paulo R.V.

    2015-01-01

    The aim of this study was to evaluate whether normal controls and human immunodeficiency virus (HIV) patients with and without planning deficits differ on white matter integrity. A total of 34 HIV-positive patients with planning deficits were compared with 13 HIV-positive patients without planning deficits and 19 gender-, age-, and education-matched control subjects. Diffusion tensor imaging (DTI) was performed along 30 noncolinear directions in a 1.5-T scanner. For tract-based spatial statistics analysis, a white matter skeleton was created, and a permutation-based inference with 5000 permutations with a threshold of p < 0.05 was used to identify abnormalities in fractional anisotropy (FA). The median, radial, and axial diffusivities were also projected onto the mean FA skeleton. Compared with controls, HIV-positive patients with planning deficits had decreased FA in bilateral anterior thalamic radiations, bilateral inferior fronto-occiptal fasciculi, genu and splenium of the corpus callosum, bilateral superior longitudinal fascicule, and bilateral uncinate fasciculi. Compared to HIV-positive patients without planning deficits, patients with planning deficits had decreased FA in bilateral anterior thalamic radiations, bilateral inferior fronto-occiptal fasciculi, genu of the corpus callosum, bilateral superior longitudinal fascicule, and right uncinate fascicule. DTI can detect extensive white matter abnormalities in the normal-appearing white matter of HIV-positive patients with planning deficits compared with controls and HIV-positive patients without planning deficits. (orig.)

  8. Diffusion tensor MR imaging of white matter integrity in HIV-positive patients with planning deficit

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Diogo Goulart; Doring, Thomas M.; Wilner, Nina Ventura; Cabral, Rafael Ferracini; Gasparetto, Emerson Leandro [Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro, RJ (Brazil); Zimmermann, Nicolle; Fonseca, Rochele Paz [Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Pontifical Catholic University of Rio Grande do Sul, Department of Psychology, Rio Grande do Sul (Brazil); Leite, Sarah C.B.; Bahia, Paulo R.V. [Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil)

    2015-05-01

    The aim of this study was to evaluate whether normal controls and human immunodeficiency virus (HIV) patients with and without planning deficits differ on white matter integrity. A total of 34 HIV-positive patients with planning deficits were compared with 13 HIV-positive patients without planning deficits and 19 gender-, age-, and education-matched control subjects. Diffusion tensor imaging (DTI) was performed along 30 noncolinear directions in a 1.5-T scanner. For tract-based spatial statistics analysis, a white matter skeleton was created, and a permutation-based inference with 5000 permutations with a threshold of p < 0.05 was used to identify abnormalities in fractional anisotropy (FA). The median, radial, and axial diffusivities were also projected onto the mean FA skeleton. Compared with controls, HIV-positive patients with planning deficits had decreased FA in bilateral anterior thalamic radiations, bilateral inferior fronto-occiptal fasciculi, genu and splenium of the corpus callosum, bilateral superior longitudinal fascicule, and bilateral uncinate fasciculi. Compared to HIV-positive patients without planning deficits, patients with planning deficits had decreased FA in bilateral anterior thalamic radiations, bilateral inferior fronto-occiptal fasciculi, genu of the corpus callosum, bilateral superior longitudinal fascicule, and right uncinate fascicule. DTI can detect extensive white matter abnormalities in the normal-appearing white matter of HIV-positive patients with planning deficits compared with controls and HIV-positive patients without planning deficits. (orig.)

  9. Alterations of white matter integrity related to the season of birth in schizophrenia: a DTI study.

    Directory of Open Access Journals (Sweden)

    Stéphanie Giezendanner

    Full Text Available In schizophrenia there is a consistent epidemiological finding of a birth excess in winter and spring. Season of birth is thought to act as a proxy indicator for harmful environmental factors during foetal maturation. There is evidence that prenatal exposure to harmful environmental factors may trigger pathologic processes in the neurodevelopment, which subsequently increase the risk of schizophrenia. Since brain white matter alterations have repeatedly been found in schizophrenia, the objective of this study was to investigate whether white matter integrity was related to the season of birth in patients with schizophrenia. Thirty-four patients with schizophrenia and 33 healthy controls underwent diffusion tensor imaging. Differences in the fractional anisotropy maps of schizophrenia patients and healthy controls born in different seasons were analysed with tract-based spatial statistics. A significant main effect of season of birth and an interaction of group and season of birth showed that patients born in summer had significantly lower fractional anisotropy in widespread white matter regions than those born in the remainder of the year. Additionally, later age of schizophrenia onset was found in patients born in winter months. The current findings indicate a relationship of season of birth and white matter alterations in schizophrenia and consequently support the neurodevelopmental hypothesis of early pathological mechanisms in schizophrenia.

  10. Integrated dataset of impact of dissolved organic matter on particle behavior and phototoxicity of titanium dioxide nanoparticles

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset is generated to both qualitatively and quantitatively examine the interactions between nano-TiO2 and natural organic matter (NOM). This integrated...

  11. Memory binding and white matter integrity in familial Alzheimer’s disease

    Science.gov (United States)

    Saarimäki, Heini; Bastin, Mark E.; Londoño, Ana C.; Pettit, Lewis; Lopera, Francisco; Della Sala, Sergio; Abrahams, Sharon

    2015-01-01

    Binding information in short-term and long-term memory are functions sensitive to Alzheimer’s disease. They have been found to be affected in patients who meet criteria for familial Alzheimer’s disease due to the mutation E280A of the PSEN1 gene. However, only short-term memory binding has been found to be affected in asymptomatic carriers of this mutation. The neural correlates of this dissociation are poorly understood. The present study used diffusion tensor magnetic resonance imaging to investigate whether the integrity of white matter structures could offer an account. A sample of 19 patients with familial Alzheimer’s disease, 18 asymptomatic carriers and 21 non-carrier controls underwent diffusion tensor magnetic resonance imaging, neuropsychological and memory binding assessment. The short-term memory binding task required participants to detect changes across two consecutive screens displaying arrays of shapes, colours, or shape-colour bindings. The long-term memory binding task was a Paired Associates Learning Test. Performance on these tasks were entered into regression models. Relative to controls, patients with familial Alzheimer’s disease performed poorly on both memory binding tasks. Asymptomatic carriers differed from controls only in the short-term memory binding task. White matter integrity explained poor memory binding performance only in patients with familial Alzheimer’s disease. White matter water diffusion metrics from the frontal lobe accounted for poor performance on both memory binding tasks. Dissociations were found in the genu of corpus callosum which accounted for short-term memory binding impairments and in the hippocampal part of cingulum bundle which accounted for long-term memory binding deficits. The results indicate that white matter structures in the frontal and temporal lobes are vulnerable to the early stages of familial Alzheimer’s disease and their damage is associated with impairments in two memory binding

  12. ADRB2, brain white matter integrity and cognitive ageing in the Lothian Birth Cohort 1936.

    Science.gov (United States)

    Lyall, Donald M; Lopez, Lorna M; Bastin, Mark E; Maniega, Susana Muñoz; Penke, Lars; Valdés Hernández, Maria del C; Royle, Natalie A; Starr, John M; Porteous, David J; Wardlaw, Joanna M; Deary, Ian J

    2013-01-01

    The non-synonymous mutations arg16gly (rs1042713) and gln27glu (rs1042714) in the adrenergic β-2 receptor gene (ADRB2) have been associated with cognitive function and brain white matter integrity. The current study aimed to replicate these findings and expand them to a broader range of cognitive and brain phenotypes. The sample used is a community-dwelling group of older people, the Lothian Birth Cohort 1936. They had been assessed cognitively at age 11 years, and undertook further cognitive assessments and brain diffusion MRI tractography in older age. The sample size range for cognitive function variables was N = 686-765, and for neuroimaging variables was N = 488-587. Previously-reported findings with these genetic variants did not replicate in this cohort. Novel, nominally significant associations were observed; notably, the integrity of the left arcuate fasciculus mediated the association between rs1042714 and the Digit Symbol Coding test of information processing speed. No significant associations of cognitive and brain phenotypes with ADRB2 variants survived correction for false discovery rate. Previous findings may therefore have been subject to type 1 error. Further study into links between ADRB2, cognitive function and brain white matter integrity is required.

  13. An integrated processor for photonic quantum states using a broadband light–matter interface

    International Nuclear Information System (INIS)

    Saglamyurek, E; Sinclair, N; Slater, J A; Heshami, K; Oblak, D; Tittel, W

    2014-01-01

    Faithful storage and coherent manipulation of quantum optical pulses are key for long distance quantum communications and quantum computing. Combining these functions in a light–matter interface that can be integrated on-chip with other photonic quantum technologies, e.g. sources of entangled photons, is an important step towards these applications. To date there have only been a few demonstrations of coherent pulse manipulation utilizing optical storage devices compatible with quantum states, and that only in atomic gas media (making integration difficult) and with limited capabilities. Here we describe how a broadband waveguide quantum memory based on the atomic frequency comb (AFC) protocol can be used as a programmable processor for essentially arbitrary spectral and temporal manipulations of individual quantum optical pulses. Using weak coherent optical pulses at the few photon level, we experimentally demonstrate sequencing, time-to-frequency multiplexing and demultiplexing, splitting, interfering, temporal and spectral filtering, compressing and stretching as well as selective delaying. Our integrated light–matter interface offers high-rate, robust and easily configurable manipulation of quantum optical pulses and brings fully practical optical quantum devices one step closer to reality. Furthermore, as the AFC protocol is suitable for storage of intense light pulses, our processor may also find applications in classical communications. (paper)

  14. Q-ball imaging models: comparison between high and low angular resolution diffusion-weighted MRI protocols for investigation of brain white matter integrity

    Energy Technology Data Exchange (ETDEWEB)

    Caiazzo, Giuseppina; Trojsi, Francesca; Cirillo, Mario; Tedeschi, Gioacchino [MRI Research Center SUN-FISM-Neurological Institute for Diagnosis and Care ' ' Hermitage Capodimonte' ' , Naples (Italy); Second University of Naples, Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, Naples (Italy); Esposito, Fabrizio [University of Salerno, Department of Medicine and Surgery, Baronissi (Salerno) (Italy); Maastricht University, Department of Cognitive Neuroscience, Maastricht (Netherlands)

    2016-02-15

    Q-ball imaging (QBI) is one of the typical data models for quantifying white matter (WM) anisotropy in diffusion-weighted MRI (DwMRI) studies. Brain and spinal investigation by high angular resolution DwMRI (high angular resolution imaging (HARDI)) protocols exhibits higher angular resolution in diffusion imaging compared to low angular resolution models, although with longer acquisition times. We aimed to assess the difference between QBI-derived anisotropy values from high and low angular resolution DwMRI protocols and their potential advantages or shortcomings in neuroradiology. Brain DwMRI data sets were acquired in seven healthy volunteers using both HARDI (b = 3000 s/mm{sup 2}, 54 gradient directions) and low angular resolution (b = 1000 s/mm{sup 2}, 32 gradient directions) acquisition schemes. For both sequences, tract of interest tractography and generalized fractional anisotropy (GFA) measures were extracted by using QBI model and were compared between the two data sets. QBI tractography and voxel-wise analyses showed that some WM tracts, such as corpus callosum, inferior longitudinal, and uncinate fasciculi, were reconstructed as one-dominant-direction fiber bundles with both acquisition schemes. In these WM tracts, mean percent different difference in GFA between the two data sets was less than 5 %. Contrariwise, multidirectional fiber bundles, such as corticospinal tract and superior longitudinal fasciculus, were more accurately depicted by HARDI acquisition scheme. Our results suggest that the design of optimal DwMRI acquisition protocols for clinical investigation of WM anisotropy by QBI models should consider the specific brain target regions to be explored, inducing researchers to a trade-off choice between angular resolution and acquisition time. (orig.)

  15. MR diffusion tensor imaging voxel-based analysis of whole brain white matter in patients with amnestic-type mild cognitive impairment and mild Alzheimer disease

    International Nuclear Information System (INIS)

    Li Yadi; Feng Xiaoyuan; He Huijin; Ding Ding; Tang Weijun; Zhao Qianhua

    2011-01-01

    Objective: To evaluate the microstructural integrity of white matter (WM) in patients with amnestic mild cognitive impairment (aMCI) and mild Alzheimer's disease (AD) using voxel-based analysis (VBA), and investigate the relationship between WM abnormalities and gray matter (GM) atrophy. Methods: Thirty-three cases with aMCI, 32 cases with mild AD and 31 normal aging volunteers as control subjects were scanned on a 3.0 T MR system using diffusion tensor imaging (DTI) and three-dimensional spoiled gradient-recalled (3DSPGR) sequences. Fractional anisotropy (FA) maps and morphological images were preprocessed by SPM5 and voxel-based comparisons between the 2 patient groups and the control group were performed by t test. Results: Relative to the control group, patients with aMCI showed significantly reduced FA value in bilateral frontal, temporal and left occipital WM, left anterior part of cingulum, left inferior parietal lobule, and the WM adjacent to the triangular part of the right lateral ventricle (k ≥ 20 voxels). In mild AD, significantly reduced FA value was found in bilateral hippocampal, inferior parietal lobular, frontal, temporal, and occipital WM, bilateral corpus callosum, anterior part of cingulums, the WM adjacent to the triangular part of the bilateral lateral ventricles, left temporal stem, left thalamus, right precuneus (k ≥ 20 voxels). Significantly reduced GM volume was found in left hippocampus, parahippocampal gyrus, lingual gyrus and superior temporal gyrus, bilateral insulae and middle temporal gyri in aMCI group when compared with control group (k ≥ 50 voxels). In mild AD, significantly reduced GM volume was found in bilateral hippocampi, parahippocampal gyri, amygdalae, thalami, temporal, parietal, frontal, occipital cortex (k ≥ 50 voxels). The pattern of areas with reduced FA differs from that of the GM volumetric reduction. No areas with significantly reduced FA was detected in aMCI compared with mild AD. There was no significant

  16. Integrated evaluation of soil quality after the incorporation of organic matter and microorganisms

    Directory of Open Access Journals (Sweden)

    Valarini Pedro J.

    2002-01-01

    Full Text Available The soil quality was evaluated following the addition of organic matter and microorganisms to a clay loam soil collected in Aranjuez (Madrid under controlled conditions of temperature and moisture, and over a period of three months. The following treatments were carried out: soil (control; soil + 50 t/ha of animal manure (E50; soil + 50 t/ha of animal manure + 30l/ha of effective microorganisms (E50EM; soil + 30 t/ha of combination of various green crop residues and weeds (RC30 and soil + 30 t/ha of combination of various green crop residues and weeds + 30l/ha of effective microorganisms (RC30EM. The soil samples were taken before and after the incubation and analysed using physical, chemical and microbiological parameters. A significant increase in the production of polysaccharides and alkaline phosphatase and esterase enzymes in the treatments E50EM and RC30EM was observed, being in direct correlation with the humification of the organic matter, with the water retention at field capacity, and with the cationic exchange capacity (CEC. It can be concluded that the incorporation of microorganisms EM potentialized the soil biological activity and improved physico-chemical soil properties, contributing to a quick humification of fresh organic matter. Those findings were proved by microbiological activities of exopolysaccharides by alcaline phosphatase and esterase enzymes, which can be used as earlier and integral soil health indicators.

  17. Recreational marijuana use impacts white matter integrity and subcortical (but not cortical) morphometry.

    Science.gov (United States)

    Orr, Joseph M; Paschall, Courtnie J; Banich, Marie T

    2016-01-01

    A recent shift in legal and social attitudes toward marijuana use has also spawned a surge of interest in understanding the effects of marijuana use on the brain. There is considerable evidence that an adolescent onset of marijuana use negatively impacts white matter coherence. On the other hand, a recent well-controlled study demonstrated no effects of marijuana use on the morphometry of subcortical or cortical structures when users and non-users were matched for alcohol use. Regardless, most studies have involved small, carefully selected samples, so the ability to generalize to larger populations is limited. In an attempt to address this issue, we examined the effects of marijuana use on white matter integrity and cortical and subcortical morphometry using data from the Human Connectome Project (HCP) consortium. The HCP data consists of ultra-high resolution neuroimaging data from a large community sample, including 466 adults reporting recreational marijuana use. Rather than just contrasting two groups of individuals who vary significantly in marijuana usage as typifies prior studies, we leveraged the large sample size provided by the HCP data to examine parametric effects of recreational marijuana use. Our results indicate that the earlier the age of onset of marijuana use, the lower was white matter coherence. Age of onset also also affected the shape of the accumbens, while the number of lifetime uses impacted the shape of the amygdala and hippocampus. Marijuana use had no effect on cortical volumes. These findings suggest subtle but significant effects of recreational marijuana use on brain structure.

  18. The relationship between recognition memory for emotion-laden words and white matter microstructure in normal older individuals.

    Science.gov (United States)

    Saarela, Carina; Karrasch, Mira; Ilvesmäki, Tero; Parkkola, Riitta; Rinne, Juha O; Laine, Matti

    2016-12-14

    Functional neuroimaging studies have shown age-related differences in brain activation and connectivity patterns for emotional memory. Previous studies with middle-aged and older adults have reported associations between episodic memory and white matter (WM) microstructure obtained from diffusion tensor imaging, but such studies on emotional memory remain few. To our knowledge, this is the first study to explore associations between WM microstructure as measured by fractional anisotropy (FA) and recognition memory for intentionally encoded positive, negative, and emotionally neutral words using tract-based spatial statistics applied to diffusion tensor imaging images in an elderly sample (44 cognitively intact adults aged 50-79 years). The use of tract-based spatial statistics enables the identification of WM tracts important to emotional memory without a priori assumptions required for region-of-interest approaches that have been used in previous work. The behavioral analyses showed a positivity bias, that is, a preference for positive words, in recognition memory. No statistically significant associations emerged between FA and memory for negative or neutral words. Controlling for age and memory performance for negative and neutral words, recognition memory for positive words was negatively associated with FA in several projection, association, and commissural tracts in the left hemisphere. This likely reflects the complex interplay between the mnemonic positivity bias, structural WM integrity, and functional brain compensatory mechanisms in older age. Also, the unexpected directionality of the results indicates that the WM microstructural correlates of emotional memory show unique characteristics in normal older individuals.

  19. Structural changes of central white matter tracts in Kennedy's disease - a diffusion tensor imaging and voxel-based morphometry study.

    Science.gov (United States)

    Pieper, C C; Konrad, C; Sommer, J; Teismann, I; Schiffbauer, H

    2013-05-01

    Spinobulbar muscular atrophy [Kennedy's disease (KD)] is a rare X-linked neurodegenerative disorder of mainly spinal and bulbar motoneurons. Recent studies suggest a multisystem character of this disease. The aim of this study was to identify and characterize structural changes of gray (GM) and white matter (WM) in the central nervous system. Whole-brain-based voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) analyses were applied to MRI data of eight genetically proven patients with KD and compared with 16 healthy age-matched controls. Diffusion tensor imaging analysis showed not only decreased fractional anisotropy (FA) values in the brainstem, but also widespread changes in central WM tracts, whereas VBM analysis of the WM showed alterations primarily in the brainstem and cerebellum. There were no changes in GM volume. The FA value decrease in the brainstem correlated with the disease duration. Diffusion tensor imaging analysis revealed subtle changes of central WM tract integrity, while GM and WM volume remained unaffected. In our patient sample, KD had more extended effects than previously reported. These changes could either be attributed primarily to neurodegeneration or reflect secondary plastic changes due to atrophy of lower motor neurons and reorganization of cortical structures. © 2012 John Wiley & Sons A/S.

  20. Individual white matter fractional anisotropy analysis on patients with MRI negative partial epilepsy.

    Science.gov (United States)

    Duning, Thomas; Kellinghaus, Christoph; Mohammadi, Siawoosh; Schiffbauer, Hagen; Keller, Simon; Ringelstein, E Bernd; Knecht, Stefan; Deppe, Michael

    2010-02-01

    Conventional structural MRI fails to identify a cerebral lesion in 25% of patients with cryptogenic partial epilepsy (CPE). Diffusion tensor imaging is an MRI technique sensitive to microstructural abnormalities of cerebral white matter (WM) by quantification of fractional anisotropy (FA). The objectives of the present study were to identify focal FA abnormalities in patients with CPE who were deemed MRI negative during routine presurgical evaluation. Diffusion tensor imaging at 3 T was performed in 12 patients with CPE and normal conventional MRI and in 67 age matched healthy volunteers. WM integrity was compared between groups on the basis of automated voxel-wise statistics of FA maps using an analysis of covariance. Volumetric measurements from high resolution T1-weighted images were also performed. Significant FA reductions in WM regions encompassing diffuse areas of the brain were observed when all patients as a group were compared with controls. On an individual basis, voxel based analyses revealed widespread symmetrical FA reduction in CPE patients. Furthermore, asymmetrical temporal lobe FA reduction was consistently ipsilateral to the electroclinical focus. No significant correlations were found between FA alterations and clinical data. There were no differences in brain volumes of CPE patients compared with controls. Despite normal conventional MRI, WM integrity abnormalities in CPE patients extend far beyond the epileptogenic zone. Given that unilateral temporal lobe FA abnormalities were consistently observed ipsilateral to the seizure focus, analysis of temporal FA may provide an informative in vivo investigation into the localisation of the epileptogenic zone in MRI negative patients.

  1. Plasma DNA Mediate Autonomic Dysfunctions and White Matter Injuries in Patients with Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Meng-Hsiang Chen

    2017-01-01

    Full Text Available Background. Cardiovascular autonomic dysfunction is well known in Parkinson’s disease (PD presentation and it produces hypoperfusion of vital organs. The association between cardiovascular autonomic dysfunction and oxidative stress was examined in previous animal models. Oxidative stress and neuroinflammation were thought to have roles in PD pathogenesis. Owing to the relative low intrinsic antioxidative properties, brain white matter (WM is vulnerable to the oxidative stress. This study is conducted to examine possible relationships by using a hypothesis-driven mediation model. Methods. Twenty-nine patients with PD and 26 healthy controls participated in this study, with complete examinations of cardiac autonomic parameters, plasma DNA level, and WM integrity. A single-level three-variable mediation model was used to investigate the possible relationships. Results. The elevated serum oxidative stress biomarkers include plasma nuclear DNA and mitochondrial DNA, and poorer cardiac autonomic parameters and multiple regional microstructural WM changes are demonstrated. Further mediation analysis shows that plasma nuclear DNA served as the mediators between poorer baroreflex sensitivity and mean diffusivity changes in cingulum. Conclusions. These results provide a possible pathophysiology for how the poor baroreflex sensitivity and higher oxidative stress adversely impacted the WM integrity. This model could provide us with a piece of the puzzle of the entire PD pathogenesis.

  2. Right lateralized white matter abnormalities in first-episode, drug-naive paranoid schizophrenia.

    Science.gov (United States)

    Guo, Wenbin; Liu, Feng; Liu, Zhening; Gao, Keming; Xiao, Changqing; Chen, Huafu; Zhao, Jingping

    2012-11-30

    Numerous studies in first-episode schizophrenia suggest the involvement of white matter (WM) abnormalities in multiple regions underlying the pathogenesis of this condition. However, there has never been a neuroimaging study in patients with first-episode, drug-naive paranoid schizophrenia by using tract-based spatial statistics (TBSS) method. Here, we used diffusion tensor imaging (DTI) with TBSS method to investigate the brain WM integrity in patients with first-episode, drug-naive paranoid schizophrenia. Twenty patients with first-episode, drug-naive paranoid schizophrenia and 26 healthy subjects matched with age, gender, and education level were scanned with DTI. An automated TBSS approach was employed to analyze the data. Voxel-wise statistics revealed that patients with paranoid schizophrenia had decreased fractional anisotropy (FA) values in the right superior longitudinal fasciculus (SLF) II, the right fornix, the right internal capsule, and the right external capsule compared to healthy subjects. Patients did not have increased FA values in any brain regions compared to healthy subjects. There was no correlation between the FA values in any brain regions and patient demographics and the severity of illness. Our findings suggest right-sided alterations of WM integrity in the WM tracts of cortical and subcortical regions may play an important role in the pathogenesis of paranoid schizophrenia. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  3. White Matter Changes in HIV+ Women with a History of Cocaine Dependence

    Directory of Open Access Journals (Sweden)

    Kathryn-Mary Wakim

    2017-10-01

    Full Text Available Cocaine use is associated with the transmission of human immunodeficiency (HIV virus through risky sexual behavior. In HIV+ individuals, cocaine use is linked with poor health outcomes, including HIV-medication non-adherence and faster disease progression. Both HIV and cocaine dependence are associated with reduced integrity of cerebral white matter (WM, but the effects of HIV during cocaine abstinence have not yet been explored. We used diffusion tensor imaging (DTI to understand the effect of combined HIV+ serostatus and former cocaine dependence on cerebral WM integrity. DTI data obtained from 15 HIV+ women with a history of cocaine dependence (COC+/HIV+ and 21 healthy females were included in the analysis. Diffusion-based measures [fractional anisotropy (FA, radial diffusivity (RD, mean diffusivity, and axial diffusivity] were examined using tract-based spatial statistics and region-of-interest analyses. In a whole-brain analysis, COC+/HIV+ women showed significantly reduced FA and increased RD in all major WM tracts, except the left corticospinal tract for RD. The tract with greatest percentage of voxels showing significant between-group differences was the forceps minor (FA: 75.6%, RD: 59.7%. These widespread changes in diffusion measures indicate an extensive neuropathological effect of HIV and former cocaine dependence on WM.

  4. Evaluation of deep gray matter volume, cortical thickness and white matter integrity in patients with typical absence epilepsy: a study using voxelwise-based techniques

    International Nuclear Information System (INIS)

    Correa, D.G.; Ventura, N.; Tukamoto, G.; Gasparetto, E.L.; Zimmermann, N.; Doring, T.M.; Leme, J.; Pereira, M.; Andrea, I. d'; Rego, C.; Alves-Leon, S.V.

    2017-01-01

    The objective of this study was to evaluate the cortical thickness and the volume of deep gray matter structures, measured from 3D T1-weighted gradient echo imaging, and white matter integrity, by diffusion tensor imaging (DTI) in patients with typical absence epilepsy (AE). Patients (n = 19) with typical childhood AE and juvenile AE, currently taking antiepileptic medication, were compared with control subjects (n = 19), matched for gender and age. 3D T1 magnetization-prepared rapid gradient echo-weighted imaging and DTI along 30 noncolinear directions were performed using a 1.5-T MR scanner. FreeSurfer was used to perform cortical volumetric reconstruction and segmentation of deep gray matter structures. For tract-based spatial statistics analysis of DTI, a white matter skeleton was created, along with a permutation-based inference with 5000 permutations. A threshold of p < 0.05 was used to identify abnormalities in fractional anisotropy (FA). The mean, radial, and axial diffusivities were also projected onto the mean FA skeleton. Patients with AE presented decreased FA and increased mean diffusivity and radial diffusivity values in the genu and the body of the corpus callosum and right anterior corona radiata, as well as decreased axial diffusivity in the left posterior thalamic radiation, inferior cerebellar peduncle, right cerebral peduncle, and right corticospinal tract. However, there were no significant differences in cortical thickness or deep gray matter structure volumes between patients with AE and controls. Abnormalities found in white matter integrity may help to better understand the pathophysiology of AE and optimize diagnosis and treatment strategies. (orig.)

  5. Evaluation of deep gray matter volume, cortical thickness and white matter integrity in patients with typical absence epilepsy: a study using voxelwise-based techniques

    Energy Technology Data Exchange (ETDEWEB)

    Correa, D.G.; Ventura, N.; Tukamoto, G.; Gasparetto, E.L. [Federal University of Rio de Janeiro, Department of Radiology, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro (Brazil); Zimmermann, N. [Federal University of Rio de Janeiro, Department of Radiology, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Pontifical Catholic University of Rio Grande do Sul, Department of Psychology, Porto Alegre (Brazil); Doring, T.M. [Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro (Brazil); Leme, J.; Pereira, M. [Federal University of Rio de Janeiro, Department of Radiology, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Andrea, I. d' ; Rego, C.; Alves-Leon, S.V. [Federal University of Rio de Janeiro, Department of Neurology, Epilepsy Center, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro (Brazil)

    2017-03-15

    The objective of this study was to evaluate the cortical thickness and the volume of deep gray matter structures, measured from 3D T1-weighted gradient echo imaging, and white matter integrity, by diffusion tensor imaging (DTI) in patients with typical absence epilepsy (AE). Patients (n = 19) with typical childhood AE and juvenile AE, currently taking antiepileptic medication, were compared with control subjects (n = 19), matched for gender and age. 3D T1 magnetization-prepared rapid gradient echo-weighted imaging and DTI along 30 noncolinear directions were performed using a 1.5-T MR scanner. FreeSurfer was used to perform cortical volumetric reconstruction and segmentation of deep gray matter structures. For tract-based spatial statistics analysis of DTI, a white matter skeleton was created, along with a permutation-based inference with 5000 permutations. A threshold of p < 0.05 was used to identify abnormalities in fractional anisotropy (FA). The mean, radial, and axial diffusivities were also projected onto the mean FA skeleton. Patients with AE presented decreased FA and increased mean diffusivity and radial diffusivity values in the genu and the body of the corpus callosum and right anterior corona radiata, as well as decreased axial diffusivity in the left posterior thalamic radiation, inferior cerebellar peduncle, right cerebral peduncle, and right corticospinal tract. However, there were no significant differences in cortical thickness or deep gray matter structure volumes between patients with AE and controls. Abnormalities found in white matter integrity may help to better understand the pathophysiology of AE and optimize diagnosis and treatment strategies. (orig.)

  6. Attention, working memory, and phenomenal experience of WM content: memory levels determined by different types of top-down modulation

    OpenAIRE

    Jacob, Jane; Jacobs, Christianne; Silvanto, Juha

    2015-01-01

    What is the role of top-down attentional modulation in consciously accessing working memory (WM) content? In influential WM models, information can exist in different states, determined by allocation of attention; placing the original memory representation in the center of focused attention gives rise to conscious access. Here we discuss various lines of evidence indicating that such attentional modulation is not sufficient for memory content to be phenomenally experienced. We propose that, i...

  7. White matter integrity in veterans with mild traumatic brain injury: associations with executive function and loss of consciousness.

    Science.gov (United States)

    Sorg, Scott F; Delano-Wood, Lisa; Luc, Norman; Schiehser, Dawn M; Hanson, Karen L; Nation, Daniel A; Lanni, Elisa; Jak, Amy J; Lu, Kun; Meloy, M J; Frank, Lawrence R; Lohr, James B; Bondi, Mark W

    2014-01-01

    We investigated using diffusion tensor imaging (DTI) and the association between white matter integrity and executive function (EF) performance in postacute mild traumatic brain injury (mTBI). In addition, we examined whether injury severity, as measured by loss of consciousness (LOC) versus alterations in consciousness (AOC), is related to white matter microstructural alterations and neuropsychological outcome. Thirty Iraq and Afghanistan War era veterans with a history of mTBI and 15 healthy veteran control participants. There were no significant overall group differences between control and mTBI participants on DTI measures. However, a subgroup of mTBI participants with EF decrements (n = 13) demonstrated significantly decreased fractional anisotropy of prefrontal white matter, corpus callosum, and cingulum bundle structures compared with mTBI participants without EF decrements (n = 17) and control participants. Participants having mTBI with LOC were more likely to evidence reduced EF performances and disrupted ventral prefrontal white matter integrity when compared with either mTBI participants without LOC or control participants. Findings suggest that altered white matter integrity contributes to reduced EF in subgroups of veterans with a history of mTBI and that LOC may be a risk factor for reduced EF as well as associated changes to ventral prefrontal white matter.

  8. Recreational marijuana use impacts white matter integrity and subcortical (but not cortical morphometry

    Directory of Open Access Journals (Sweden)

    Joseph M. Orr

    2016-01-01

    Full Text Available A recent shift in legal and social attitudes toward marijuana use has also spawned a surge of interest in understanding the effects of marijuana use on the brain. There is considerable evidence that an adolescent onset of marijuana use negatively impacts white matter coherence. On the other hand, a recent well-controlled study demonstrated no effects of marijuana use on the morphometry of subcortical or cortical structures when users and non-users were matched for alcohol use. Regardless, most studies have involved small, carefully selected samples, so the ability to generalize to larger populations is limited. In an attempt to address this issue, we examined the effects of marijuana use on white matter integrity and cortical and subcortical morphometry using data from the Human Connectome Project (HCP consortium. The HCP data consists of ultra-high resolution neuroimaging data from a large community sample, including 466 adults reporting recreational marijuana use. Rather than just contrasting two groups of individuals who vary significantly in marijuana usage as typifies prior studies, we leveraged the large sample size provided by the HCP data to examine parametric effects of recreational marijuana use. Our results indicate that the earlier the age of onset of marijuana use, the lower was white matter coherence. Age of onset also also affected the shape of the accumbens, while the number of lifetime uses impacted the shape of the amygdala and hippocampus. Marijuana use had no effect on cortical volumes. These findings suggest subtle but significant effects of recreational marijuana use on brain structure.

  9. 2C-R4WM Spectroscopy of Jet Cooled NO_3

    Science.gov (United States)

    Fukushima, Masaru; Ishiwata, Takashi; Hirota, Eizi

    2016-06-01

    We have generated NO_3 from pyrolysis of N_2O_5 following supersonic free jet expansion, and carried out two color resonant four wave mixing ( 2C-R4WM ) spectroscopy of the tilde{B} ^2E' - tilde{X} ^2A_2' electronic transition. One laser was fixed to pump NO_3 to a ro-vibronic level of the tilde{B} state, and the other laser ( probe ) was scanned across two levels of the tilde{X} ^2A_2' state lying at 1051 and 1492 cm-1, the ν_1 (a_1') and ν_3 (e') fundamentals, respectively. The 2C-R4WM spectra have unexpected back-ground signal of NO_3 ( stray signal due to experimental set-up is also detected ) similar to laser induced fluorescence ( LIF ) excitation spectrum of the 0-0 band, although the back-ground signal was not expected in considering the 2C-R4WM scheme. Despite the back-ground interference, we have observed two peaks at 1051.61 and 1055.29 cm-1 in the ν_1 region of the spectrum, and the frequencies agree with the two bands, 1051.2 and 1055.3 cm-1, of our relatively higher resolution dispersed fluorescence spectrum, the former of which has been assigned to the ν_1 fundamental. Band width of both peaks, ˜ 0.2 cm-1, is broader than twice the experimental spectral-resolution, 0.04 cm-1 ( because this experiment is double resonance spectroscopy ), and the 1051.61 cm-1 peak is attributed to a Q branch band head ( a line-like Q branch ) of the ν_1 fundamental. The other branches are suspected to be hidden in noise of the back-ground signal. The 1055.29 cm-1 peak is also attributed to a Q band head. The tilde{B} ^2E'1/2 ( J' = 3/2, K' = 1 ) - tilde{X} ^2A_2' ( N'' = 1, K'' = 0 ) ro-vibronic transition was used as the pump transition. The dump ( probe ) transition to both a_1' and e' vibronic levels are then allowed as perpendicular transition. Accordingly, it cannot be determined from present results whether the 1055.29 cm-1 band is attributed to a_1' or e' (ν_3), unfortunately. The 2C-R4WM spectrum of the 1492 cm-1 band region shows one Q head at 1499.79 cm

  10. Microstructural integrity of white matter tracts amongst older fallers: A DTI study.

    Directory of Open Access Journals (Sweden)

    Yoke Queen Wong

    Full Text Available This study assesses the whole brain microstructural integrity of white matter tracts (WMT among older individuals with a history of falls compared to non-fallers.85 participants (43 fallers, 42 non-fallers were evaluated with conventional MRI and diffusion tensor imaging (DTI sequences of the brain. DTI metrics were obtained from selected WMT using tract-based spatial statistics (TBSS method. This was followed by binary logistic regression to investigate the clinical variables that could act as confounding elements on the outcomes. The TBSS analysis was then repeated, but this time including all significant predictor variables from the regression analysis as TBSS covariates.The mean diffusivity (MD and axial diffusivity (AD and to a lesser extent radial diffusivity (RD values of the projection fibers and commissural bundles were significantly different in fallers (p < 0.05 compared to non-fallers. However, the final logistic regression model obtained showed that only functional reach, white matter lesion volume, hypertension and orthostatic hypotension demonstrated statistical significant differences between fallers and non-fallers. No significant differences were found in the DTI metrics when taking into account age and the four variables as covariates in the repeated analysis.This DTI study of 85 subjects, do not support DTI metrics as a singular factor that contributes independently to the fall outcomes. Other clinical and imaging factors have to be taken into account.

  11. Abnormal white matter integrity in the corpus callosum among smokers: tract-based spatial statistics.

    Directory of Open Access Journals (Sweden)

    Wakako Umene-Nakano

    Full Text Available In the present study, we aimed to investigate the difference in white matter between smokers and nonsmokers. In addition, we examined relationships between white matter integrity and nicotine dependence parameters in smoking subjects. Nineteen male smokers were enrolled in this study. Eighteen age-matched non-smokers with no current or past psychiatric history were included as controls. Diffusion tensor imaging scans were performed, and the analysis was conducted using a tract-based special statistics approach. Compared with nonsmokers, smokers exhibited a significant decrease in fractional anisotropy (FA throughout the whole corpus callosum. There were no significant differences in radial diffusivity or axial diffusivity between the two groups. There was a significant negative correlation between FA in the whole corpus callosum and the amount of tobacco use (cigarettes/day; R = - 0.580, p = 0.023. These results suggest that the corpus callosum may be one of the key areas influenced by chronic smoking.

  12. Non-integrable dynamics of matter-wave solitons in a density-dependent gauge theory

    Science.gov (United States)

    Dingwall, R. J.; Edmonds, M. J.; Helm, J. L.; Malomed, B. A.; Öhberg, P.

    2018-04-01

    We study interactions between bright matter-wave solitons which acquire chiral transport dynamics due to an optically-induced density-dependent gauge potential. Through numerical simulations, we find that the collision dynamics feature several non-integrable phenomena, from inelastic collisions including population transfer and radiation losses to the formation of short-lived bound states and soliton fission. An effective quasi-particle model for the interaction between the solitons is derived by means of a variational approximation, which demonstrates that the inelastic nature of the collision arises from a coupling of the gauge field to velocities of the solitons. In addition, we derive a set of interaction potentials which show that the influence of the gauge field appears as a short-range potential, that can give rise to both attractive and repulsive interactions.

  13. Integrable open spin chains and the doubling trick in N = 2 SYM with fundamental matter

    International Nuclear Information System (INIS)

    Erler, Theodore G.; Mann, Nelia

    2006-01-01

    We demonstrate that the one-loop anomalous dimension matrix in N = 2 SYM with a single chiral hypermultiplet of fundamental matter, which is dual to AdS 5 x S 5 with a D7-brane filling AdS 5 and wrapped around an S 3 in the S 5 , is an integrable open spin chain Hamiltonian. We also use the doubling trick to relate these open spin chains to closed spin chains in pure N = 4 SYM. By using the AdS/CFT correspondence, we find a relation between the corresponding open and closed strings that differs from a simple doubling trick by terms that vanish in the semiclassical limit. We also demonstrate that in some cases the closed string is simpler and easier to study than the corresponding open string, and we speculate on the nature of corrections due to the presence of D-branes that this implies

  14. Remote Lower White Matter Integrity Increases the Risk of Long-Term Cognitive Impairment After Ischemic Stroke in Young Adults.

    Science.gov (United States)

    Schaapsmeerders, Pauline; Tuladhar, Anil M; Arntz, Renate M; Franssen, Sieske; Maaijwee, Noortje A M; Rutten-Jacobs, Loes C A; Schoonderwaldt, Hennie C; Dorresteijn, Lucille D A; van Dijk, Ewoud J; Kessels, Roy P C; de Leeuw, Frank-Erik

    2016-10-01

    Poststroke cognitive impairment occurs frequently in young patients with ischemic stroke (18 through 50 years of age). Accumulating data suggest that stroke is associated with lower white matter integrity remote from the stroke impact area, which might explain why some patients have good long-term cognitive outcome and others do not. Given the life expectancy of decades in young patients, we therefore investigated remote white matter in relation to long-term cognitive function. We included all consecutive first-ever ischemic stroke patients, left/right hemisphere, without recurrent stroke or transient ischemic attack during follow-up, aged 18 through 50 years, admitted to our university medical center between 1980 and 2010. One hundred seventeen patients underwent magnetic resonance imaging scanning including a T1-weighted scan, a diffusion tensor imaging scan, and completed a neuropsychological assessment. Patients were compared with a matched stroke-free control group (age, sex, and education matched). Cognitive impairment was defined as >1.5 SD below the mean cognitive index score of controls and no cognitive impairment as ≤1 SD. Tract-Based Spatial Statistics was used to assess the white matter integrity (fractional anisotropy and mean diffusivity). About 11 years after ischemic stroke, lower remote white matter integrity was associated with a worse long-term cognitive performance. A lower remote white matter integrity, even in the contralesional hemisphere, was observed in cognitively impaired patients (n=25) compared with cognitively unimpaired patients (n=71). These findings indicate that although stroke has an acute onset, it might have long lasting effects on remote white matter integrity and thereby increases the risk of long-term cognitive impairment. © 2016 American Heart Association, Inc.

  15. Quantifying white matter structural integrity with high-definition fiber tracking in traumatic brain injury.

    Science.gov (United States)

    Presson, Nora; Krishnaswamy, Deepa; Wagener, Lauren; Bird, William; Jarbo, Kevin; Pathak, Sudhir; Puccio, Ava M; Borasso, Allison; Benso, Steven; Okonkwo, David O; Schneider, Walter

    2015-03-01

    There is an urgent, unmet demand for definitive biological diagnosis of traumatic brain injury (TBI) to pinpoint the location and extent of damage. We have developed High-Definition Fiber Tracking, a 3 T magnetic resonance imaging-based diffusion spectrum imaging and tractography analysis protocol, to quantify axonal injury in military and civilian TBI patients. A novel analytical methodology quantified white matter integrity in patients with TBI and healthy controls. Forty-one subjects (23 TBI, 18 controls) were scanned with the High-Definition Fiber Tracking diffusion spectrum imaging protocol. After reconstruction, segmentation was used to isolate bilateral hemisphere homologues of eight major tracts. Integrity of segmented tracts was estimated by calculating homologue correlation and tract coverage. Both groups showed high correlations for all tracts. TBI patients showed reduced homologue correlation and tract spread and increased outlier count (correlations>2.32 SD below control mean). On average, 6.5% of tracts in the TBI group were outliers with substantial variability among patients. Number and summed deviation of outlying tracts correlated with initial Glasgow Coma Scale score and 6-month Glasgow Outcome Scale-Extended score. The correlation metric used here can detect heterogeneous damage affecting a low proportion of tracts, presenting a potential mechanism for advancing TBI diagnosis. Reprint & Copyright © 2015 Association of Military Surgeons of the U.S.

  16. Comparison of diffusion tensor imaging and voxel-based morphometry to detect white matter damage in Alzheimer's disease.

    Science.gov (United States)

    Yoon, Bora; Shim, Yong-S; Hong, Yun-Jeong; Koo, Bang-Bon; Kim, Yong-Duk; Lee, Kee-Ook; Yang, Dong-Won

    2011-03-15

    Regional atrophy of gray matter (GM) in Alzheimer's disease (AD) is well known; however, the relationship between macroscopic and microscopic changes of cerebral white matter (WM) is uncertain. The aim of this study was to investigate the pattern of GM, WM atrophy, and microscopic WM changes in the same individuals with AD. All subjects (10AD and 15 healthy controls [HC]) underwent a MRI scanning at 1.5 T, including a 3-dimensional volumetric scan and diffusion tensor imaging (DTI). We performed statistical parametric mapping (SPM) with DTI to evaluate the patterns of the microscopic WM changes, as well as voxel-based morphometry (VBM) for GM and WM volume changes between patients with AD and HC. GM atrophy was detected, mainly in posterior regions, and WM atrophy was similarly distributed, but less involved on VBM analysis. Unlike WM atrophy on VBM analysis, microscopic WM changes were shown in the medial frontal, orbitofrontal, splenium of the corpus callosum, and cingulum on DTI analysis with SPM. We demonstrated that the pattern of macroscopic WM atrophy was similar to GM atrophy, while microscopic WM changes had a different pattern and distribution. Our findings suggest that WM atrophy may preferentially reflect the secondary changes of GM atrophy, while microscopic WM changes start earlier in frontal areas before GM and WM atrophy can be detected macroscopically. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. Pittsburgh compound-B PET white matter imaging and cognitive function in late multiple sclerosis.

    Science.gov (United States)

    Zeydan, Burcu; Lowe, Val J; Schwarz, Christopher G; Przybelski, Scott A; Tosakulwong, Nirubol; Zuk, Samantha M; Senjem, Matthew L; Gunter, Jeffrey L; Roberts, Rosebud O; Mielke, Michelle M; Benarroch, Eduardo E; Rodriguez, Moses; Machulda, Mary M; Lesnick, Timothy G; Knopman, David S; Petersen, Ronald C; Jack, Clifford R; Kantarci, Kejal; Kantarci, Orhun H

    2018-05-01

    There is growing interest in white matter (WM) imaging with positron emission tomography (PET). We studied the association of cognitive function in late multiple sclerosis (MS) with cortical and WM Pittsburgh compound-B PET (PiB-PET) binding. In the population-based Mayo Clinic Study of Aging, 24 of 4869 participants had MS (12 underwent PiB-PET). Controls were age and sex matched (5:1). We used automated or semi-automated processing for quantitative image analyses and conditional logistic regression for group differences. MS patients had lower memory ( p = 0.03) and language ( p = 0.02) performance; smaller thalamic volumes ( p = 0.003); and thinner temporal ( p = 0.001) and frontal ( p = 0.045) cortices on magnetic resonance imaging (MRI) than controls. There was no difference in global cortical PiB standardized uptake value ratios between MS and controls ( p = 0.35). PiB uptake was lower in areas of WM hyperintensities compared to normal-appearing white matter (NAWM) in MS ( p = 0.0002). Reduced PiB uptake in both the areas of WM hyperintensities ( r = 0.65; p = 0.02) and NAWM ( r = 0.69; p = 0.01) was associated with decreased visuospatial performance in MS. PiB uptake in the cortex in late MS is not different from normal age-matched controls. PiB uptake in the WM in late MS may be a marker of the large network structures' integrity such as those involved in visuospatial performance.

  18. Abnormal white matter microstructure among early adulthood smokers: a tract-based spatial statistics study.

    Science.gov (United States)

    Wang, Shuangkun; Zuo, Long; Jiang, Tao; Peng, Peng; Chu, Shuilian; Xiao, Dan

    2017-12-01

    Objectives Cigarette smoking is an important risk factor of central nervous system diseases. However, the white matter (WM) integrity of early adulthood chronic smokers has not been attached enough importance to as it deserves, and the relationship between the chronic smoking effect and the WM is still unclear. The purpose of this study was to investigate whole - brain WM microstructure of early adulthood smokers and explore the structural correlates of behaviorally relevant features of the disorder. Methods We compared multiple DTI-derived indices, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD), between early adulthood smokers (n = 19) and age-, education- and gender-matched controls (n = 23) using a whole-brain tract-based spatial statistics approach. We also explored the correlations of the mean DTI index values with pack-years and Fagerström Test for Nicotine Dependence. Results The smokers showed increased FA in left superior longitudinal fasciculus (SLF), left anterior corona radiate, left superior corona radiate, left posterior corona radiate, left external capsule (EC), left inferior fronto-occipital fasciculus and sagittal stratum (SS), and decreased RD in left SLF. There were significant negative correlations among the average FA in the left external capsule and pack-years in smokers. In addition, significant positive correlation was found between RD values in the left SLF and pack-years. Discussion These findings indicate that smokers show microstructural changes in several white-matter regions. The correlation between the cumulative effect and microstructural WM alternations suggests that WM properties may become the new biomarkers in practice.

  19. Hemispheric Differences in White Matter Microstructure between Two Profiles of Children with High Intelligence Quotient vs. Controls: A Tract-Based Spatial Statistics Study

    Science.gov (United States)

    Nusbaum, Fanny; Hannoun, Salem; Kocevar, Gabriel; Stamile, Claudio; Fourneret, Pierre; Revol, Olivier; Sappey-Marinier, Dominique

    2017-01-01

    Objectives: The main goal of this study was to investigate and compare the neural substrate of two children's profiles of high intelligence quotient (HIQ). Methods: Two groups of HIQ children were included with either a homogeneous (Hom-HIQ: n = 20) or a heterogeneous IQ profile (Het-HIQ: n = 24) as defined by a significant difference between verbal comprehension index and perceptual reasoning index. Diffusion tensor imaging was used to assess white matter (WM) microstructure while tract-based spatial statistics (TBSS) analysis was performed to detect and localize WM regional differences in fractional anisotropy (FA), mean diffusivity, axial (AD), and radial diffusivities. Quantitative measurements were performed on 48 regions and 21 fiber-bundles of WM. Results: Hom-HIQ children presented higher FA than Het-HIQ children in widespread WM regions including central structures, and associative intra-hemispheric WM fasciculi. AD was also greater in numerous WM regions of Total-HIQ, Hom-HIQ, and Het-HIQ groups when compared to the Control group. Hom-HIQ and Het-HIQ groups also differed by their hemispheric lateralization in AD differences compared to Controls. Het-HIQ and Hom-HIQ groups showed a lateralization ratio (left/right) of 1.38 and 0.78, respectively. Conclusions: These findings suggest that both inter- and intra-hemispheric WM integrity are enhanced in HIQ children and that neural substrate differs between Hom-HIQ and Het-HIQ. The left hemispheric lateralization of Het-HIQ children is concordant with their higher verbal index while the relative right hemispheric lateralization of Hom-HIQ children is concordant with their global brain processing and adaptation capacities as evidenced by their homogeneous IQ. PMID:28420955

  20. In Vivo Evidence of Reduced Integrity of the Gray-White Matter Boundary in Autism Spectrum Disorder.

    Science.gov (United States)

    Andrews, Derek Sayre; Avino, Thomas A; Gudbrandsen, Maria; Daly, Eileen; Marquand, Andre; Murphy, Clodagh M; Lai, Meng-Chuan; Lombardo, Michael V; Ruigrok, Amber N V; Williams, Steven C; Bullmore, Edward T; The Mrc Aims Consortium; Suckling, John; Baron-Cohen, Simon; Craig, Michael C; Murphy, Declan G M; Ecker, Christine

    2017-02-01

    Atypical cortical organization and reduced integrity of the gray-white matter boundary have been reported by postmortem studies in individuals with autism spectrum disorder (ASD). However, there are no in vivo studies that examine these particular features of cortical organization in ASD. Hence, we used structural magnetic resonance imaging to examine differences in tissue contrast between gray and white matter in 98 adults with ASD and 98 typically developing controls, to test the hypothesis that individuals with ASD have significantly reduced tissue contrast. More specifically, we examined contrast as a percentage between gray and white matter tissue signal intensities (GWPC) sampled at the gray-white matter boundary, and across different cortical layers. We found that individuals with ASD had significantly reduced GWPC in several clusters throughout the cortex (cluster, P gray-white matter interface, which indicates a less distinct gray-white matter boundary in ASD. Our in vivo findings of reduced GWPC in ASD are therefore consistent with prior postmortem findings of a less well-defined gray-white matter boundary in ASD. Taken together, these results indicate that GWPC might be utilized as an in vivo proxy measure of atypical cortical microstructural organization in future studies. © The Author 2017. Published by Oxford University Press.

  1. Path Integral Monte Carlo Simulations of Warm Dense Matter and Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Militzer, Burkhard [Univ. of California, Berkeley, CA (United States)

    2018-01-13

    New path integral Monte Carlo simulation (PIMC) techniques will be developed and applied to derive the equation of state (EOS) for the regime of warm dense matter and dense plasmas where existing first-principles methods cannot be applied. While standard density functional theory has been used to accurately predict the structure of many solids and liquids up to temperatures on the order of 10,000 K, this method is not applicable at much higher temperature where electronic excitations become important because the number of partially occupied electronic orbitals reaches intractably large numbers and, more importantly, the use of zero-temperature exchange-correlation functionals introduces an uncontrolled approximation. Here we focus on PIMC methods that become more and more efficient with increasing temperatures and still include all electronic correlation effects. In this approach, electronic excitations increase the efficiency rather than reduce it. While it has commonly been assumed such methods can only be applied to elements without core electrons like hydrogen and helium, we recently showed how to extend PIMC to heavier elements by performing the first PIMC simulations of carbon and water plasmas [Driver, Militzer, Phys. Rev. Lett. 108 (2012) 115502]. Here we propose to continue this important development to extend the reach of PIMC simulations to yet heavier elements and also lower temperatures. The goal is to provide a robust first-principles simulation method that can accurately and efficiently study materials with excited electrons at solid-state densities in order to access parts of the phase diagram such the regime of warm dense matter and plasmas where so far only more approximate, semi-analytical methods could be applied.

  2. Developing Pre-Service Teachers' Subject Matter Knowledge of Electromagnetism by Integrating Concept Maps and Collaborative Learning

    Science.gov (United States)

    Govender, Nadaraj

    2015-01-01

    This case study explored the development of two pre-service teachers' subject matter knowledge (SMK) of electromagnetism while integrating the use of concept maps (CM) and collaborative learning (CL) strategies. The study aimed at capturing how these pre-service teachers' SMK in electromagnetism was enhanced after having been taught SMK in a…

  3. Remote lower white matter integrity increases the risk of long-term cognitive impairment after ischemic stroke in young adults

    NARCIS (Netherlands)

    Schaapsmeerders, P.; Tuladhar, A.M.; Arntz, R.M.; Franssen, S.; Maaijwee, N.A.M.M.; Rutten-Jacobs, L.C.A.; Schoonderwaldt, H.C.; Dorresteijn, L.D.A.; Dijk, E.J. van; Kessels, R.P.C.; Leeuw, H.F. de

    2016-01-01

    Background and Purpose: Poststroke cognitive impairment occurs frequently in young patients with ischemic stroke (18 through 50 years of age). Accumulating data suggest that stroke is associated with lower white matter integrity remote from the stroke impact area, which might explain why some

  4. Remote lower white matter integrity increases the risk of long-term cognitive impairment after ischemic stroke in young adults

    NARCIS (Netherlands)

    Schaapsmeerders, P.; Tuladhar, A.M.; Arntz, R.M.; Franssen, S.; Maaijwee, N.A.M.M.; Rutten-Jacobs, L.C.A.; Schoonderwaldt, H.C.; Dorresteijn, L.D.A.; Dijk, E.J. van; Kessels, R.P.C.; Leeuw, F.E. de

    2016-01-01

    BACKGROUND AND PURPOSE: Poststroke cognitive impairment occurs frequently in young patients with ischemic stroke (18 through 50 years of age). Accumulating data suggest that stroke is associated with lower white matter integrity remote from the stroke impact area, which might explain why some

  5. 76 FR 19174 - In the Matter of Circuit Systems, Inc., Global Energy Group, Inc., Integrated Medical Resources...

    Science.gov (United States)

    2011-04-06

    ... SECURITIES AND EXCHANGE COMMISSION File No. 500-1 In the Matter of Circuit Systems, Inc., Global Energy Group, Inc., Integrated Medical Resources, Inc., iNTELEFILM Corp., and Lot$off Corp.; Order of... lack of current and accurate information concerning the securities of Circuit Systems, Inc. because it...

  6. Loss of white matter integrity is associated with gait disorders in cerebral small vessel disease

    NARCIS (Netherlands)

    Laat, K.F. de; Tuladhar, A.M.; Norden, A.G.W. van; Norris, D.G.; Zwiers, M.P.; Leeuw, F.E. de

    2011-01-01

    Gait disturbances are common in the elderly. Cerebral small vessel disease, including white matter lesions and lacunars infarcts, is thought to disrupt white matter tracts that connect important motor regions, hence resulting in gait disturbances. Pathological studies have demonstrated abnormalities

  7. Altered whole-brain white matter networks in preclinical Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Florian Udo Fischer

    2015-01-01

    Our results suggest an impairment of WM networks in preclinical AD that is detectable while other structural imaging markers do not yet indicate incipient neurodegeneration. Moreover, these findings are specific to WM networks and cannot be explained by other surrogates of global WM integrity.

  8. Spatial characteristics of white matter abnormalities in schizophrenia

    NARCIS (Netherlands)

    T.J.H. White (Tonya); S.M. Ehrlich (Stefan); B.C. Ho (Beng ); D.S. Manoach (Dara); A. Caprihan (Arvind); S.C. Schulz (S. Charles); N.C. Andreasen; R.L. Gollub (Randy); V.D. Calhoun (Vince); V. Magnotta

    2013-01-01

    textabstractThere is considerable evidence implicating brain white matter (WM) abnormalities in the pathophysiology of schizophrenia; however, the spatial localization of WM abnormalities reported in the existing studies is heterogeneous. Thus, the goal of this study was to quantify the spatial

  9. Non-pharmacological modulation of cerebral white matter organization

    DEFF Research Database (Denmark)

    Kristensen, Tina D; Mandl, Rene C W; Jepsen, Jens R M

    2018-01-01

    OBJECTIVE: Neuroplasticity is a well-described phenomenon, but effects of non-pharmacological interventions on white matter (WM) are unclear. Here we review associations between active non-pharmacological interventions and WM organization in healthy subjects and in psychiatric patients. METHOD...

  10. The Wm. H. Zimmer Nuclear Power Station: Draft environmental statement (Docket No. 50-358)

    International Nuclear Information System (INIS)

    1976-10-01

    The proposed action is the issuance of an operating license to the Cincinnati Gas and Electric Company, the Columbus and Southern Ohio Electric Company, and the Dayton Power and Light Company for the startup and operation of the Wm. H. Zimmer Nuclear Power Station (Docket No. 50-358) (the station), located on the Ohio River in Clermont County, about 24 miles southeast of Cincinnati, Ohio. The information in this statement represents the second assessment of the environmental impact associated with the Zimmer Nuclear Power Station pursuant to the guidelines of the National Environmental Policy Act of 1969 (NEPA) and 10 CFR Part 51 of the Commission's Regulations. After receipt of an application in 1970 to construct this plant, the staff carried out a review of impact that would occur during the plant's construction and operation. This evaluation was issued as a final environmental statement in September 1972. As the result of this environmental review, a safety review, an evaluation by the Advisory Committee on Reactor Safeguards, and a public hearing in Cincinnati, Ohio, the AEC (now NRC) issued a permit in October 1972 for the construction of Unit 1 of the Zimmer Nuclear Power Station. As of June 1976, the construction of the plant was 54% complete. With a proposed fuel-loading data of April 1978, the applicant has petitioned for license to operate Unit 1 and has submitted (September 1975) the required safety and environmental reports to substantiate this petition. 96 refs., 17 figs., 34 tabs

  11. White-matter microstructure and language lateralization in left-handers: a whole-brain MRI analysis.

    Science.gov (United States)

    Perlaki, Gabor; Horvath, Reka; Orsi, Gergely; Aradi, Mihaly; Auer, Tibor; Varga, Eszter; Kantor, Gyongyi; Altbäcker, Anna; John, Flora; Doczi, Tamas; Komoly, Samuel; Kovacs, Norbert; Schwarcz, Attila; Janszky, Jozsef

    2013-08-01

    Most people are left-hemisphere dominant for language. However the neuroanatomy of language lateralization is not fully understood. By combining functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI), we studied whether language lateralization is associated with cerebral white-matter (WM) microstructure. Sixteen healthy, left-handed women aged 20-25 were included in the study. Left-handers were targeted in order to increase the chances of involving subjects with atypical language lateralization. Language lateralization was determined by fMRI using a verbal fluency paradigm. Tract-based spatial statistics analysis of DTI data was applied to test for WM microstructural correlates of language lateralization across the whole brain. Fractional anisotropy and mean diffusivity were used as indicators of WM microstructural organization. Right-hemispheric language dominance was associated with reduced microstructural integrity of the left superior longitudinal fasciculus and left-sided parietal lobe WM. In left-handed women, reduced integrity of the left-sided language related tracts may be closely linked to the development of right hemispheric language dominance. Our results may offer new insights into language lateralization and structure-function relationships in human language system. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. A retrospective study of white matter integrity in mild cognitive impairment

    Science.gov (United States)

    van Bruggen, Thomas; Stieltjes, Bram; Meinzer, Hans-Peter; Fritzsche, Klaus H.

    2011-03-01

    Prior work has shown that white matter fiber integrity decreases in Alzheimer's disease (AD) and mild cognitive impairment (MCI). This can be achieved by quantifying anisotropic water movement in the brain using diffusion tensor imaging techniques. Since less than half (but still a considerable amount) of the MCI patients convert to AD it is important to identify features that can predict the chance of conversion to AD within a certain time frame. In this study we applied tract-based spatial statistics (TBSS) in order to perform this task, which overcomes limitations that are commonly associated with ROI-based approaches and voxel-based morphometry (VBM). Diffusion weighted images were taken from 15 healthy controls, 15 AD patients and 17 MCI patients. 8 MCI patients remained stable within 3 years of follow-up investigations ("non-converters" or MCI-nc) and 9 converted to AD ("converters" or MCI-c). Significant differences between the MCI-nc and MCI-c groups were found in large parts of the fornix, the corpus callosum and the cingulum. In comparison, the MCI-c group did not differ significantly from the AD group and the MCI-nc group exhibited features similar to the control group in most parts of the structures. These results demonstrate that, although MCI-c and MCI-nc patients were clinically similar at time of inclusion, the MCI-c group already exhibited pathologic features of fiber integrity associated with AD. This finding could lead to more powerful techniques in the early identification of AD and thus support an earlier and more successful treatment.

  13. White matter disruption in moderate/severe pediatric traumatic brain injury: Advanced tract-based analyses

    Directory of Open Access Journals (Sweden)

    Emily L. Dennis

    2015-01-01

    Full Text Available Traumatic brain injury (TBI is the leading cause of death and disability in children and can lead to a wide range of impairments. Brain imaging methods such as DTI (diffusion tensor imaging are uniquely sensitive to the white matter (WM damage that is common in TBI. However, higher-level analyses using tractography are complicated by the damage and decreased FA (fractional anisotropy characteristic of TBI, which can result in premature tract endings. We used the newly developed autoMATE (automated multi-atlas tract extraction method to identify differences in WM integrity. 63 pediatric patients aged 8–19 years with moderate/severe TBI were examined with cross sectional scanning at one or two time points after injury: a post-acute assessment 1–5 months post-injury and a chronic assessment 13–19 months post-injury. A battery of cognitive function tests was performed in the same time periods. 56 children were examined in the first phase, 28 TBI patients and 28 healthy controls. In the second phase 34 children were studied, 17 TBI patients and 17 controls (27 participants completed both post-acute and chronic phases. We did not find any significant group differences in the post-acute phase. Chronically, we found extensive group differences, mainly for mean and radial diffusivity (MD and RD. In the chronic phase, we found higher MD and RD across a wide range of WM. Additionally, we found correlations between these WM integrity measures and cognitive deficits. This suggests a distributed pattern of WM disruption that continues over the first year following a TBI in children.

  14. The Struggle of Integration: James Baldwin and Melanie Klein in the Context of Black Lives Matter

    Directory of Open Access Journals (Sweden)

    David W McIvor

    2016-12-01

    Full Text Available Recent killings of unarmed black citizens are a fresh reminder of the troubled state of racial integration in the United States. At the same time, the unfolding Black Lives Matter protest movements and the responses by federal agencies each testify to a not insignificant capacity for addressing social pathologies surrounding the color line. In order to respond to this ambivalent situation, this article suggests a pairing between the work of James Baldwin and that of the psychoanalyst Melanie Klein. I will argue that we cannot fully appreciate the depths of what Baldwin called the “savage paradox” of race without the insights provided by Klein and object relations psychoanalysis. Conversely, Baldwin helps us to sound out the political significance of object relations approaches, including the work of Klein and those influenced by her such as Hanna Segal and Wilfred Bion. In conversation with the work of Baldwin, object relations theory can help to identify particular social settings and institutions that might allow concrete efforts toward racial justice to take root.

  15. NASA's Universe of Learning: The Integral Role of Research Astronomers and Other Subject Matter Experts

    Science.gov (United States)

    Lee, Janice; Universe of Learning Team

    2018-01-01

    Astronomy seeks to understand the workings of the Universe on its largest scales, and to answer fundamental questions about the story of our origins. The science of astronomy thus naturally lends itself to informal education and public outreach activities, as it broadly captures the human imagination. There are at least three overall goals for investment of resources in Astronomy E/PO: to interest students in pursuing STEM education and careers; to develop Astronomy as context for teaching more basic physical and computer science in service of US National Education Goals; to help motivate continued public support of federally funded Astronomy research and technology development. Providing a full spectrum of opportunities for the public to learn about recent Astronomy discoveries is key to achieving these societal goals. Thus, the E/PO professional community must have an understanding of recent scientific/technological results, and engage with the researchers who are creating new knowledge to explicate that knowledge to the public. It stands to reason that researchers (or “subject matter experts, SMEs”) must be involved in and remain connected to the E/PO endeavor. In this talk, I will describe how research astronomers and other SMEs play an integral role in a full range of informal education programming developed by the NASA Universe of Learning collaboration, and opportunities to get involved.

  16. “The Relationship between Executive Functioning, Processing Speed and White Matter Integrity in Multiple Sclerosis”

    Science.gov (United States)

    Genova, Helen M.; DeLuca, John; Chiaravalloti, Nancy; Wylie, Glenn

    2014-01-01

    The primary purpose of the current study was to examine the relationship between performance on executive tasks and white matter integrity, assessed by diffusion tensor imaging (DTI) in Multiple Sclerosis (MS). A second aim was to examine how processing speed affects the relationship between executive functioning and FA. This relationship was examined in two executive tasks that rely heavily on processing speed: the Color-Word Interference Test and Trail-Making Test (Delis-Kaplan Executive Function System). It was hypothesized that reduced fractional anisotropy (FA) is related to poor performance on executive tasks in MS, but that this relationship would be affected by the statistical correction of processing speed from the executive tasks. 15 healthy controls and 25 persons with MS participated. Regression analyses were used to examine the relationship between executive functioning and FA, both before and after processing speed was removed from the executive scores. Before processing speed was removed from the executive scores, reduced FA was associated with poor performance on Color-Word Interference Test and Trail-Making Test in a diffuse network including corpus callosum and superior longitudinal fasciculus. However, once processing speed was removed, the relationship between executive functions and FA was no longer significant on the Trail Making test, and significantly reduced and more localized on the Color-Word Interference Test. PMID:23777468

  17. Emotion detection deficits and changes in personality traits linked to loss of white matter integrity in primary progressive aphasia

    Directory of Open Access Journals (Sweden)

    Namita Multani

    2017-01-01

    Full Text Available Non-cognitive features including personality changes are increasingly recognized in the three PPA variants (semantic-svPPA, non fluent-nfvPPA, and logopenic-lvPPA. However, differences in emotion processing among the PPA variants and its association with white matter tracts are unknown. We compared emotion detection across the three PPA variants and healthy controls (HC, and related them to white matter tract integrity and cortical degeneration. Personality traits in the PPA group were also examined in relation to white matter tracts. Thirty-three patients with svPPA, nfvPPA, lvPPA, and 32 HC underwent neuropsychological assessment, emotion evaluation task (EET, and MRI scan. Patients' study partners were interviewed on the Clinical Dementia Rating Scale (CDR and completed an interpersonal traits assessment, the Interpersonal Adjective Scale (IAS. Diffusion tensor imaging of uncinate fasciculus (UF, superior longitudinal fasciculus (SLF and inferior longitudinal fasciculus (ILF, and voxel-based morphometry to derive gray matter volumes for orbitofrontal cortex (OFC, anterior temporal lobe (ATL regions were performed. In addition, gray matter volumes of white matter tract-associated regions were also calculated: inferior frontal gyrus (IFG, posterior temporal lobe (PTL, inferior parietal lobe (IPL and occipital lobe (OL. ANCOVA was used to compare EET performance. Partial correlation and multivariate linear regression were conducted to examine association between EET and neuroanatomical regions affected in PPA. All three variants of PPA performed significantly worse than HC on EET, and the svPPA group was least accurate at recognizing emotions. Performance on EET was related to the right UF, SLF, and ILF integrity. Regression analysis revealed EET performance primarily relates to the right UF integrity. The IAS subdomain, cold-hearted, was also associated with right UF integrity. Disease-specific emotion recognition and personality changes occur

  18. Effect of integrated forage rotation and manure management on yield, nutrient balance and soil organic matter

    Directory of Open Access Journals (Sweden)

    Cesare Tomasoni

    2011-03-01

    Full Text Available This paper reports results from a field experiment established in 1995 and still on going. It is located in Lodi, in the irrigated lowlands of Lombardy, Northern Italy. The experiment compares two rotations: the annual double cropping system, Italian ryegrass + silage maize (R1; and the 6-year rotation, in which three years of double crop Italian ryegrass + silage maize are followed by three years of alfalfa harvested for hay (R6 Each rotation have received two types of dairy manure: i farmyard manure (FYM; ii semi-liquid manure (SLM. The intent was to apply to each unit land area the excreta produced by the number of adult dairy cows sustained, in terms of net energy, by the forage produced in each rotation, corresponding to about 6 adult cows ha-1 for R1 and 4 adult cows ha-1 for R6. Manure was applied with (N1 or without (N0 an extra supply of mineral N in the form of urea. The objectives of this study were: i to assess whether the recycling of two types of manure in two forage rotation systems can sustain crop yields in the medium and long term without additional N fertilization; ii to evaluate the nutrient balance of these integrated forage rotations and manure management systems; iii to compare the effects of farmyard manure and semi-liquid manure on soil organic matter. The application of FYM, compared to SLM, increased yield of silage maize by 19% and alfalfa by 23%, while Italian ryegrass was not influenced by the manure treatment. Yet, silage maize produced 6% more in rotation R6 compared to rotation R1. The mineral nitrogen fertilization increased yield of Italian ryegrass by 11% and of silage maize by 10%. Alfalfa, not directly fertilized with mineral nitrogen, was not influenced by the nitrogen applied to the other crops in rotation. The application of FYM, compared to SLM, increased soil organic matter (SOM by +37 % for the rotation R1, and by +20% for the rotation R6. Conversely, no significant difference on SOM was observed

  19. Dissolved organic and inorganic matter in bulk deposition of a coastal urban area: an integrated approach.

    Science.gov (United States)

    Santos, Patrícia S M; Santos, Eduarda B H; Duarte, Armando C

    2014-12-01

    Bulk deposition can remove atmospheric organic and inorganic pollutants that may be associated with gaseous, liquid or particulate phases. To the best of our knowledge, few studies have been carried out, which simultaneously analyse the presence of organic and inorganic fractions in rainwater. In the present work, the complementarity of organic and inorganic data was assessed, through crossing data of some organic [DOC (dissolved organic carbon), absorbance at 250 nm (UV250nm), integrated fluorescence] and inorganic [H(+), NH4(+), NO3(-), non sea salt sulphate (NSS-SO4(2-))] parameters measured in bulk deposition in the coastal urban area of Aveiro. The organic and inorganic parameters analysed were positively correlated (pCDOM) came from anthropogenic sources. Furthermore, the inverse correlations observed for the organic and inorganic parameters with the precipitation amount suggest that organic and inorganic fractions were incorporated into the rainwater partially by below-cloud scavenging of airborne particulate matter. This is in accordance with the high values of DOC and NO3(-) found in samples associated with marine air masses, which were linked in part to the contribution of local emissions from vehicular traffic. DOC of bulk deposition was the predominant constituent when compared with the constituents H(+), NH4(+), NO3(-) and NSS-SO4(2-), and consequently bulk deposition flux was also highest for DOC, highlighting the importance of DOC and of anthropogenic ions being simultaneously removed from the atmosphere by bulk deposition. However, it was verified that the contribution of anthropogenic sources to the DOC of bulk deposition may be different for distinct urban areas. Thus, it is recommended that organic and inorganic fractions of bulk deposition are studied together. Copyright © 2014. Published by Elsevier Ltd.

  20. QUANTITY AND QUALITY OF SOIL ORGANIC MATTER IN ECOLOGICAL AND INTEGRATED FARMING SYSTEM

    Directory of Open Access Journals (Sweden)

    ERIKA TOBIAŠOVÁ

    2012-09-01

    Full Text Available Impact of farming system on the quantity and quality of soil organic matter was studied. The experiment was situated on Haplic Luvisol of Research – experimental base of Slovak University of Agriculture Dolná Malanta, where over a period of 5 years soil samples from ecological (ES and integrated (IS farming system were collected. In period of 5 years, on average higher contents of total organic carbon (TOC and total nitrogen (NT were in ES (1.219%; 1382 mg.kg-1 than in IS (1.121%; 1262 mg.kg-1. TOC content in the ES was on the level of variants with application of farmyard manure, while in the IS it was on the level of non-fertilized variants. The highest contents of TOC and non-labile carbon (CNL were recorded in 2010 when the previous crops were alfalfa (Medicago sativa and pea (Pisum sativum. Higher content of CNL was in the ES than in the IS. A positive linear relationship between the amounts of precipitation per year and during the vegetation was observed not only between TOC contents (r = 0.914, P < 0.05 and r = 0.971, P < 0.01, but also CNL contents (r = 0.880, P < 0.05 and r = 0.952, P < 0.05. The most stabilized humus substances were in 2007, when the highest average temperature per year and during the vegetation was recorded. In 2010, the lowest amounts of extracted humus substances were recorded, with domination of humic acids. Their stability, however, on the base of colour coefficients of humus substances and humic acids were the lowest from all years. The humus substances were more stabilized in the IS than in the ES.

  1. Effects of a Balanced Translocation between Chromosomes 1 and 11 Disrupting the DISC1 Locus on White Matter Integrity.

    Directory of Open Access Journals (Sweden)

    Heather C Whalley

    Full Text Available Individuals carrying rare, but biologically informative genetic variants provide a unique opportunity to model major mental illness and inform understanding of disease mechanisms. The rarity of such variations means that their study involves small group numbers, however they are amongst the strongest known genetic risk factors for major mental illness and are likely to have large neural effects. DISC1 (Disrupted in Schizophrenia 1 is a gene containing one such risk variant, identified in a single Scottish family through its disruption by a balanced translocation of chromosomes 1 and 11; t(1;11 (q42.1;q14.3.Within the original pedigree, we examined the effects of the t(1;11 translocation on white matter integrity, measured by fractional anisotropy (FA. This included family members with (n = 7 and without (n = 13 the translocation, along with a clinical control sample of patients with psychosis (n = 34, and a group of healthy controls (n = 33.We report decreased white matter integrity in five clusters in the genu of the corpus callosum, the right inferior fronto-occipital fasciculus, acoustic radiation and fornix. Analysis of the mixed psychosis group also demonstrated decreased white matter integrity in the above regions. FA values within the corpus callosum correlated significantly with positive psychotic symptom severity.We demonstrate that the t(1;11 translocation is associated with reduced white matter integrity in frontal commissural and association fibre tracts. These findings overlap with those shown in affected patients with psychosis and in DISC1 animal models and highlight the value of rare but biologically informative mutations in modeling psychosis.

  2. White matter abnormalities and their impact on attentional performance in adult attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Konrad, Andreas; Dielentheis, Thomas F; El Masri, Dschamil; Dellani, Paulo R; Stoeter, Peter; Vucurevic, Goran; Winterer, Georg

    2012-06-01

    Inattention is the most important behavioral feature of adult patients with attention-deficit/hyperactivity disorder (ADHD). Neuroimaging studies in ADHD have demonstrated abnormalities primarily in the frontostriatal circuitry and were mostly conducted in children. We investigated white matter (WM) integrity in adult ADHD patients and the correlation of WM microstructure and neuropsychological parameters in 37 (21 men) never-medicated adult ADHD patients and 34 age- and gender-matched healthy controls. All subjects underwent clinical interviews, rating scales, and neuropsychological tests of attentional performance. Diffusion tensor imaging (DTI) was acquired, and 12 WM regions-of-interest (ROIs) within the attentional network were chosen. Group differences of mean fractional anisotropy (FA) and mean diffusivity (MD) values were calculated for each ROI, and patients' DTI measures were then correlated with measures of attentional performance. FA values in ADHD patients were significantly reduced in the left inferior longitudinal fasciculus (ILF), while MD values were significantly increased in ADHD patients in the frontal portion of the left frontooccipital fasciculus (IFO). In ADHD patients, MD values were negatively correlated with attentional performance in the left ILF. Our findings provide further support for disturbed frontostriatal structural connectivity and also point to an involvement of the left temporal white matter with an impact on attentional performance.

  3. White matter damage impairs access to consciousness in multiple sclerosis.

    Science.gov (United States)

    Reuter, Françoise; Del Cul, Antoine; Malikova, Irina; Naccache, Lionel; Confort-Gouny, Sylviane; Cohen, Laurent; Cherif, André Ali; Cozzone, Patrick J; Pelletier, Jean; Ranjeva, Jean-Philippe; Dehaene, Stanislas; Audoin, Bertrand

    2009-01-15

    Global neuronal workspace theory predicts that damage to long-distance white matter (WM) tracts should impair access to consciousness during the perception of brief stimuli. To address this issue, we studied visual backward masking in 18 patients at the very first clinical stage of multiple sclerosis (MS), a neurological disease characterized by extensive WM damage, and in 18 matched healthy subjects. In our masking paradigm, the visibility of a digit stimulus increases non-linearly as a function of the interval duration between this target and a subsequent mask. In order to characterize quantitatively, for each subject, the transition between non-conscious and conscious perception of the stimulus, we used non-linear regression to fit a sigmoid curve to objective performance and subjective visibility reports as a function of target-mask delay. The delay corresponding to the inflexion point of the sigmoid, where visibility suddenly increases, was termed the "non-linear transition threshold" and used as a summary measure of masking efficiency. Objective and subjective non-linear transition thresholds were highly correlated across subjects in both groups, and were higher in patients compared to controls. In patients, variations in the non-linear transition threshold were inversely correlated to the Magnetization transfer ratio (MTR) values inside the right dorsolateral prefrontal WM, the right occipito-frontal fasciculus and the left cerebellum. This study provides clinical evidence of a relationship between impairments of conscious access and integrity of large WM bundles, particularly involving prefrontal cortex, as predicted by global neuronal workspace theory.

  4. Age-related reduction of adaptive brain response during semantic integration is associated with gray matter reduction.

    Directory of Open Access Journals (Sweden)

    Zude Zhu

    Full Text Available While aging is associated with increased knowledge, it is also associated with decreased semantic integration. To investigate brain activation changes during semantic integration, a sample of forty-eight 25-75 year-old adults read sentences with high cloze (HC and low cloze (LC probability while functional magnetic resonance imaging was conducted. Significant age-related reduction of cloze effect (LC vs. HC was found in several regions, especially the left middle frontal gyrus (MFG and right inferior frontal gyrus (IFG, which play an important role in semantic integration. Moreover, when accounting for global gray matter volume reduction, the age-cloze correlation in the left MFG and right IFG was absent. The results suggest that brain structural atrophy may disrupt brain response in aging brains, which then show less brain engagement in semantic integration.

  5. Changes in functional organization and white matter integrity in the connectome in Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Sule Tinaz

    2017-01-01

    Our results suggest that despite subtle white matter connectivity changes, the overall structural organization of the PD connectome remains robust at relatively early disease stages. However, there is a breakdown in the functional modular organization of the PD connectome.

  6. Effects of low-level sarin and cyclosarin exposure on white matter integrity in Gulf War Veterans.

    Science.gov (United States)

    Chao, Linda L; Zhang, Yu; Buckley, Shannon

    2015-05-01

    We previously found evidence of reduced gray and white matter volume in Gulf War (GW) veterans with predicted low-level exposure to sarin (GB) and cyclosarin (GF). Because loss of white matter tissue integrity has been linked to both gray and white matter atrophy, the current study sought to test the hypothesis that GW veterans with predicted GB/GF exposure have evidence of disrupted white matter microstructural integrity. Measures of fractional anisotropy and directional (i.e., axial and radial) diffusivity were assessed from the 4T diffusion tensor images (DTI) of 59 GW veterans with predicted GB/GF exposure and 59 "matched" unexposed GW veterans (mean age: 48 ± 7 years). The DTI data were analyzed using regions of interest (ROI) analyses that accounted for age, sex, total brain gray and white matter volume, trauma exposure, posttraumatic stress disorder, current major depression, and chronic multisymptom illness status. There were no significant group differences in fractional anisotropy or radial diffusivity. However, there was increased axial diffusivity in GW veterans with predicted GB/GF exposure compared to matched, unexposed veterans throughout the brain, including the temporal stem, corona radiata, superior and inferior (hippocampal) cingulum, inferior and superior fronto-occipital fasciculus, internal and external capsule, and superficial cortical white matter blades. Post hoc analysis revealed significant correlations between higher fractional anisotropy and lower radial diffusivity with better neurobehavioral performance in unexposed GW veterans. In contrast, only increased axial diffusivity in posterior limb of the internal capsule was associated with better psychomotor function in GW veterans with predicted GB/GF exposure. The finding that increased axial diffusivity in a region of the brain that contains descending corticospinal fibers was associated with better psychomotor function and the lack of significant neurobehavioral deficits in veterans

  7. Configuration Path Integral Monte Carlo. Ab initio simulations of fermions in the warm dense matter regime

    Energy Technology Data Exchange (ETDEWEB)

    Schoof, Tim

    2017-03-08

    The reliable quantum mechanical description of thermodynamic properties of fermionic many-body systems at high densities and strong degeneracy is of increasing interest due to recent experimental progress in generating systems that exhibit a non-trivial interplay of quantum, temperature, and coupling effects. While quantum Monte Carlo methods are among the most accurate approaches for the description of the ground state, finite-temperature path integral Monte Carlo (PIMC) simulations cannot correctly describe weakly to moderately coupled and strongly degenerate Fermi systems due to the so-called fermion sign problem. By switching from the coordinate representation to a basis of anti-symmetric Slater-determinants, the Configuration Path Integral Monte Carlo (CPIMC) approach greatly reduces the sign problem and allows for the exact computation of thermodynamic properties in this regime. During this work, the CPIMC algorithm was greatly improved in terms of efficiency and accessible observables. The first successful implementation of the diagrammatic worm algorithm for a general Hamiltonian in Fock space with arbitrary pair interactions gives direct access to the Matsubara Green function. This allows for the reconstruction of dynamic properties from simulations in thermodynamic equilibrium and significantly reduces the statistical variance of derived estimators, such as the one-particle density. The strongly improved MC sampling, the much more efficient calculation of update probabilities, and the successful parallelization to thousands of CPU cores, which have been achieved as part of the new implementation, are essential for the subsequent application of the method to much larger systems than in previous works. This thesis demonstrates the capabilities of the CPIMC approach for a model system of Coulomb interacting fermions in a two-dimensional harmonic trap. The correctness of the CPIMC implementation is verified by rigorous comparisons with an exact

  8. Assessing Working Memory in Children: The Comprehensive Assessment Battery for Children – Working Memory (CABC-WM)

    OpenAIRE

    Cabbage, Kathryn; Brinkley, Shara; Gray, Shelley; Alt, Mary; Cowan, Nelson; Green, Samuel; Kuo, Trudy; Hogan, Tiffany P.

    2017-01-01

    The Comprehensive Assessment Battery for Children - Working Memory (CABC-WM) is a computer-based battery designed to assess different components of working memory in young school-age children. Working memory deficits have been identified in children with language-based learning disabilities, including dyslexia1 2 and language impairment3 4, but it is not clear whether these children exhibit deficits in subcomponents of working memory, such as visuospatial or phonological working memory. The C...

  9. Patterns of white matter microstructure in individuals at ultra-high-risk for psychosis

    DEFF Research Database (Denmark)

    Krakauer, K; Ebdrup, B H; Glenthøj, B Y

    2017-01-01

    BACKGROUND: Individuals at ultra-high-risk (UHR) for psychosis present with emerging symptoms and decline in functioning. Previous univariate analyses have indicated widespread white matter (WM) aberrations in multiple brain regions in UHR individuals and patients with schizophrenia. Using multiv......, MO, and higher RD. CONCLUSIONS: UHR individuals demonstrate complex brain patterns of WM abnormalities. Despite the subtle psychopathology of UHR individuals, aberrations in WM appear associated with positive and negative symptoms as well as level of functioning....

  10. Alzheimer's disease susceptibility genes APOE and TOMM40, and brain white matter integrity in the Lothian Birth Cohort 1936.

    Science.gov (United States)

    Lyall, Donald M; Harris, Sarah E; Bastin, Mark E; Muñoz Maniega, Susana; Murray, Catherine; Lutz, Michael W; Saunders, Ann M; Roses, Allen D; Valdés Hernández, Maria del C; Royle, Natalie A; Starr, John M; Porteous, David J; Wardlaw, Joanna M; Deary, Ian J

    2014-06-01

    Apolipoprotein E (APOE) ε genotype has previously been significantly associated with cognitive, brain imaging, and Alzheimer's disease-related phenotypes (e.g., age of onset). In the TOMM40 gene, the rs10524523 ("523") variable length poly-T repeat polymorphism has more recently been associated with similar ph/enotypes, although the allelic directions of these associations have varied between initial reports. Using diffusion magnetic resonance imaging tractography, the present study aimed to investigate whether there are independent effects of apolipoprotein E (APOE) and TOMM40 genotypes on human brain white matter integrity in a community-dwelling sample of older adults, the Lothian Birth Cohort 1936 (mean age = 72.70 years, standard deviation = 0.74, N approximately = 640-650; for most analyses). Some nominally significant effects were observed (i.e., covariate-adjusted differences between genotype groups at p vs. absence) were found in the right ventral cingulum and left inferior longitudinal fasciculus. To test for biologically independent effects of the TOMM40 523 repeat, participants were stratified into APOE genotype subgroups, so that any significant effects could not be attributed to APOE variation. In participants with the APOE ε3/ε4 genotype, effects of TOMM40 523 status were found in the left uncinate fasciculus, left rostral cingulum, left ventral cingulum, and a general factor of white matter integrity. In all 4 of these tractography measures, carriers of the TOMM40 523 "short" allele showed lower white matter integrity when compared with carriers of the "long" and "very-long" alleles. Most of these effects survived correction for childhood intelligence test scores and vascular disease history, though only the effect of TOMM40 523 on the left ventral cingulum integrity survived correction for false discovery rate. The effects of APOE in this older population are more specific and restricted compared with those reported in previous studies, and the

  11. 75 FR 5804 - In the Matter of: Certain Semiconductor Integrated Circuits and Products Containing Same; Notice...

    Science.gov (United States)

    2010-02-04

    ... Semiconductor Integrated Circuits and Products Containing Same; Notice of Commission Determination To Review in... importation of certain semiconductor integrated circuits and products containing same by reason of... (collectively ``Seagate''). Qimonda accuses of infringement certain LSI integrated circuits, as well as certain...

  12. Anatomical abnormalities in gray and white matter of the cortical surface in persons with schizophrenia.

    Directory of Open Access Journals (Sweden)

    Tiziano Colibazzi

    Full Text Available Although schizophrenia has been associated with abnormalities in brain anatomy, imaging studies have not fully determined the nature and relative contributions of gray matter (GM and white matter (WM disturbances underlying these findings. We sought to determine the pattern and distribution of these GM and WM abnormalities. Furthermore, we aimed to clarify the contribution of abnormalities in cortical thickness and cortical surface area to the reduced GM volumes reported in schizophrenia.We recruited 76 persons with schizophrenia and 57 healthy controls from the community and obtained measures of cortical and WM surface areas, of local volumes along the brain and WM surfaces, and of cortical thickness.We detected reduced local volumes in patients along corresponding locations of the brain and WM surfaces in addition to bilateral greater thickness of perisylvian cortices and thinner cortex in the superior frontal and cingulate gyri. Total cortical and WM surface areas were reduced. Patients with worse performance on the serial-position task, a measure of working memory, had a higher burden of WM abnormalities.Reduced local volumes along the surface of the brain mirrored the locations of abnormalities along the surface of the underlying WM, rather than of abnormalities of cortical thickness. Moreover, anatomical features of white matter, but not cortical thickness, correlated with measures of working memory. We propose that reductions in WM and smaller total cortical surface area could be central anatomical abnormalities in schizophrenia, driving, at least partially, the reduced regional GM volumes often observed in this illness.

  13. Atypical functional connectivity in autism spectrum disorder is associated with disrupted white matter microstructural organisation

    Directory of Open Access Journals (Sweden)

    Jane eMcGrath

    2013-09-01

    Full Text Available Disruption of structural and functional neural connectivity has been widely reported in Autism Spectrum Disorder (ASD but there is a striking lack of research attempting to integrate analysis of functional and structural connectivity in the same study population, an approach that may provide key insights into the specific neurobiological underpinnings of altered functional connectivity in autism. The aims of this study were 1. to determine whether functional connectivity abnormalities were associated with structural abnormalities of white matter (WM in ASD and 2. to examine the relationships between aberrant neural connectivity and behaviour in ASD. 22 individuals with ASD and 22 age, IQ-matched controls completed a high-angular-resolution diffusion MRI scan. Structural connectivity was analysed using constrained spherical deconvolution based tractography. Regions for tractography were generated from the results of a previous study, in which 10 pairs of brain regions showed abnormal functional connectivity during visuospatial processing in ASD. WM tracts directly connected 5 of the 10 region pairs that showed abnormal functional connectivity; linking a region in the left occipital lobe (left BA19 and five paired regions: left caudate head, left caudate body, left uncus, left thalamus and left cuneus. Measures of WM microstructural organisation were extracted from these tracts. Fractional anisotropy reductions in the ASD group relative to controls were significant for WM connecting left BA19 to left caudate head and left BA19 to left thalamus. Using a multimodal imaging approach, this study has revealed aberrant white matter microstructure in tracts that directly connect brain regions that are abnormally functionally connected in ASD. These results provide novel evidence to suggest that structural brain pathology may contribute 1. to abnormal functional connectivity and 2. to atypical visuospatial processing in ASD.

  14. White Matter Integrity Dissociates Verbal Memory and Auditory Attention Span in Emerging Adults with Congenital Heart Disease.

    Science.gov (United States)

    Brewster, Ryan C; King, Tricia Z; Burns, Thomas G; Drossner, David M; Mahle, William T

    2015-01-01

    White matter disruptions have been identified in individuals with congenital heart disease (CHD). However, no specific theory-driven relationships between microstructural white matter disruptions and cognition have been established in CHD. We conducted a two-part study. First, we identified significant differences in fractional anisotropy (FA) of emerging adults with CHD using Tract-Based Spatial Statistics (TBSS). TBSS analyses between 22 participants with CHD and 18 demographically similar controls identified five regions of normal appearing white matter with significantly lower FA in CHD, and two higher. Next, two regions of lower FA in CHD were selected to examine theory-driven differential relationships with cognition: voxels along the left uncinate fasciculus (UF; a tract theorized to contribute to verbal memory) and voxels along the right middle cerebellar peduncle (MCP; a tract previously linked to attention). In CHD, a significant positive correlation between UF FA and memory was found, r(20)=.42, p=.049 (uncorrected). There was no correlation between UF and auditory attention span. A positive correlation between MCP FA and auditory attention span was found, r(20)=.47, p=.027 (uncorrected). There was no correlation between MCP and memory. In controls, no significant relationships were identified. These results are consistent with previous literature demonstrating lower FA in younger CHD samples, and provide novel evidence for disrupted white matter integrity in emerging adults with CHD. Furthermore, a correlational double dissociation established distinct white matter circuitry (UF and MCP) and differential cognitive correlates (memory and attention span, respectively) in young adults with CHD.

  15. Methods That Matter: Integrating Mixed Methods for More Effective Social Science Research

    Science.gov (United States)

    Hay, M. Cameron, Ed.

    2016-01-01

    To do research that really makes a difference--the authors of this book argue--social scientists need questions and methods that reflect the complexity of the world. Bringing together a consortium of voices across a variety of fields, "Methods that Matter" offers compelling and successful examples of mixed methods research that do just…

  16. Morphometric analysis of gray matter integrity in individuals with early-treated phenylketonuria.

    Science.gov (United States)

    Christ, Shawn E; Price, Mason H; Bodner, Kimberly E; Saville, Christopher; Moffitt, Amanda J; Peck, Dawn

    2016-05-01

    The most widely-reported neurologic finding in individuals with early-treated phenylketonuria (PKU) is abnormality in the white matter of the brain. In contrast, much less is known regarding the impact of PKU on cortical gray matter (GM) structures. Presently, we applied advanced morphometric methods to the analysis of high-resolution structural MRI images from a sample of 19 individuals with early-treated PKU and an age- and gender-matched comparison group of 22 healthy individuals without PKU. Data analysis revealed decreased GM volume in parietal cortex for the PKU group compared with the non-PKU group. A similar trend was observed for occipital GM volume. There was no evidence of group-related differences in frontal or temporal GM volume. Within the PKU group, we also found a significant relationship between blood phenylalanine levels and GM volume for select posterior cortical sub-regions. Taken together with previous research on white matter and gray matter abnormalities in PKU, the present findings point to the posterior cortices as the primary site of neurostructural changes related to early-treated PKU. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Integrating Quality Matters into Hybrid Course Design: A Principles of Marketing Case Study

    Science.gov (United States)

    Young, Mark R.

    2014-01-01

    Previous research supports the idea that the success of hybrid or online delivery modes is more a function of course design than delivery media. This article describes a case study of a hybrid Principles of Marketing course that implemented a comprehensive redesign based on design principles espoused by the Quality Matters Program, a center for…

  18. Integrated indoor and outdoor exposure assessment framework for fine particulate matter pollution

    DEFF Research Database (Denmark)

    McKone, Thomas E; Hodas, Natasha; Apte, Joshua S.

    2016-01-01

    The 2010 Global Burden of Disease report demonstrates that fine particulate matter (PM2.5) pollution is the major environmental contributor to mortality. Exposures outdoors (ambient) and indoors (household) contribute almost qually to this burden. Unfortunately, the health impacts from exposure t...

  19. Integrated analysis of gray and white matter alterations in attention-deficit/hyperactivity disorder

    NARCIS (Netherlands)

    Francx, W.C.; Llera, A.; Mennes, M.; Zwiers, M.P.; Faraone, S.V; Oosterlaan, J.; Heslenfeld, D.; Hoekstra, P.J.; Hartman, C.A.; Franke, B.; Buitelaar, J.K.; Beckmann, C.F.

    2016-01-01

    BACKGROUND: Magnetic resonance imaging (MRI) is able to provide detailed insights into the structural organization of the brain, e.g., by means of mapping brain anatomy and white matter microstructure. Understanding interrelations between MRI modalities, rather than mapping modalities in isolation,

  20. Integrated analysis of gray and white matter alterations in attention-deficit/hyperactivity disorder

    NARCIS (Netherlands)

    Francx, Winke; Llera, Alberto; Mennes, Maarten; Zwiers, Marcel P.; Faraone, Stephen V.; Oosterlaan, Jaap; Heslenfeld, Dirk; Hoekstra, Pieter J.; Hartman, Catharina A.; Franke, Barbara; Buitelaar, Jan K.; Beckmann, Christian F.

    2016-01-01

    Background: Magnetic resonance imaging (MRI) is able to provide detailed insights into the structural organization of the brain, e.g., by means of mapping brain anatomy and white matter microstructure. Understanding interrelations between MRI modalities, rather than mapping modalities in isolation,

  1. White matter abnormalities in treatment-naive adolescents at the earliest stages of Anorexia Nervosa: A diffusion tensor imaging study.

    Science.gov (United States)

    Gaudio, Santino; Quattrocchi, Carlo Cosimo; Piervincenzi, Claudia; Zobel, Bruno Beomonte; Montecchi, Francesca Romana; Dakanalis, Antonios; Riva, Giuseppe; Carducci, Filippo

    2017-08-30

    Few studies have examined white matter (WM) integrity in long-lasting Anorexia Nervosa (AN) patients using Diffusion Tensor Imaging (DTI). In this paper, we investigated WM integrity at the earliest stages of AN (i.e. less than 6 months duration). Fourteen treatment-naive female adolescents with AN restrictive type (AN-r) in its earliest stages and 15 age-matched healthy females received brain MRI. Fractional Anisotropy (FA), Axial Diffusivity (AD), Radial diffusivity (RD), and Mean Diffusivity (MD) maps were computed from DTI data using Tract-Based Spatial Statistics analysis. AN-r patients showed FA decreases compared to controls (p FWE < 0.05) mainly in left anterior and superior corona radiata and left superior longitudinal fasciculus. AN-r patients also showed decreased AD in superior longitudinal fasciculus bilaterally and left superior and anterior corona radiata, (p FWE < 0.05). No significant differences were found in RD and MD values between the two groups. FA and AD integrity appears to be specifically affected at the earliest stages of AN. Alterations in the microstructural properties of the above mentioned tracts, also involved in cognitive control and visual perception and processing, may be early mechanisms of vulnerability/resilience of WM in AN and sustain the key symptoms of AN, such as impaired cognitive flexibility and body image distortion. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  2. Minerals as Time-Integrating Luminescence Detectors for setting bounds on dark matter particle characteristics

    International Nuclear Information System (INIS)

    Polymeris, G.S.; Kitis, G.; Liolios, A.K.; Tsirliganis, N.C.; Zioutas, K.

    2006-01-01

    Terrestrial material, since its formation, is supposed to receive additional radiation dose from its exposure to fluxes of dark matter particles. The present work investigates the possibility for bound estimation of interaction parameters of dark matter particles with ordinary matter, by measuring the accumulated doses of certain geological materials. It is proposed that Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) could enable the differentiation between the individual dose components, attributing a possible excessive dose, beyond the anticipated from cosmic rays and environmental radioactivity, to interactions with dark matter particles. Dosimetric properties of natural calcium fluoride, such as low detectable dose limit and low energy threshold (well below 1keV), indicate it as a promising Thermoluminescent Dosimeter (TLD) for the proposed method. The limitations imposed by the 'background' of cosmic rays and environmental radioactivity are discussed, and initial limits for the interaction strengths with ordinary matter, and/or the mass of WIMPs and axions are derived. The use of sedimentary quartz, sited in a free-from background-radiation environment, would yield a value of 4x10 -8 GeV -1 as an upper limit for the axion-to-photon interaction constant g aγγ and a value of 3x10 -8 GeV as a lower limit for the neutralino mass. The best limits, g aγγ =1.1x10 -10 GeV -1 for solar axions and m=3000GeV for neutralinos, could be derived for natural calcium fluoride as a dosimeter

  3. Time projection chambers with integrated pixels and their application to fast neutron detection and dark matter searches

    Energy Technology Data Exchange (ETDEWEB)

    Seong, I.S., E-mail: issung83@gmail.com; Beamer, K.; Hedges, M.T.; Jaegle, I.; Rosen, M.D.; Ross, S.J.; Thorpe, T.N.; Vahsen, S.E.; Yamaoka, J.

    2013-12-21

    We present our most recent work on the use of integrated silicon pixel electronics to read out gas-filled Time Projection Chambers (TPCs). Such detectors have great promise to measure the direction and energy of neutral particles via nuclear recoils that ionize the gas. We report on ongoing studies and refinement of the first prototype constructed at the University of Hawaii. We present data on the detection of alpha particles and fast neutrons using Ar:CO{sub 2} (70:30) and He:CO{sub 2} (70:30) gas, respectively. We also present plans and sensitivity estimates for a future Dark Matter search based on the technology under study.

  4. Comparing brain white matter on sequential cranial ultrasound and MRI in very preterm infants

    Energy Technology Data Exchange (ETDEWEB)

    Leijser, Lara M.; Veen, Sylvia; Boer, Inge P. de; Walther, Frans J.; Wezel-Meijler, Gerda van [Leiden University Medical Center, Department of Pediatrics, Division of Neonatology, Albinusdreef 2, P.O. Box 9600, Leiden (Netherlands); Liauw, Lishya [Leiden University Medical Center, Department of Radiology, Division of Neuroradiology, Albinusdreef 2, P.O. Box 9600, Leiden (Netherlands)

    2008-09-15

    Periventricular white matter (WM) echodensities, frequently seen in preterm infants, can be associated with suboptimal neurodevelopment. Major WM injury is well detected on cranial ultrasound (cUS). cUS seems less sensitive for diffuse or more subtle WM injury. Our aim was to assess the value of cUS and magnetic resonance imaging (MRI) for evaluating WM changes and the predictive value of cUS and/or MRI findings for neurodevelopmental outcome in very preterm infants with normal to severely abnormal WM on sequential high-quality cUS. Very preterm infants (<32 weeks) who had sequential cUS and one MRI within the first three postnatal months were included. Periventricular WM on cUS and MRI was compared and correlated with neurodevelopmental outcome at 2 years corrected age. Forty preterm infants were studied; outcome data were available in 32. WM changes on sequential cUS were predictive of WM changes on MRI. Severely abnormal WM on cUS/MRI was predictive of adverse outcome, and normal-mildly abnormal WM of favorable outcome. Moderately abnormal WM on cUS/MRI was associated with variable outcome. Additional MRI slightly increased the predictive value of cUS in severe WM changes. Sequential cUS in preterm infants is reliable for detecting WM changes and predicting favorable and severely abnormal outcome. Conventional and diffusion-weighted MRI sequences before term equivalent age in very preterm infants, suggested on cUS to have mild to moderately abnormal WM, do not seem to be warranted. (orig.)

  5. Comparing brain white matter on sequential cranial ultrasound and MRI in very preterm infants

    International Nuclear Information System (INIS)

    Leijser, Lara M.; Veen, Sylvia; Boer, Inge P. de; Walther, Frans J.; Wezel-Meijler, Gerda van; Liauw, Lishya

    2008-01-01

    Periventricular white matter (WM) echodensities, frequently seen in preterm infants, can be associated with suboptimal neurodevelopment. Major WM injury is well detected on cranial ultrasound (cUS). cUS seems less sensitive for diffuse or more subtle WM injury. Our aim was to assess the value of cUS and magnetic resonance imaging (MRI) for evaluating WM changes and the predictive value of cUS and/or MRI findings for neurodevelopmental outcome in very preterm infants with normal to severely abnormal WM on sequential high-quality cUS. Very preterm infants (<32 weeks) who had sequential cUS and one MRI within the first three postnatal months were included. Periventricular WM on cUS and MRI was compared and correlated with neurodevelopmental outcome at 2 years corrected age. Forty preterm infants were studied; outcome data were available in 32. WM changes on sequential cUS were predictive of WM changes on MRI. Severely abnormal WM on cUS/MRI was predictive of adverse outcome, and normal-mildly abnormal WM of favorable outcome. Moderately abnormal WM on cUS/MRI was associated with variable outcome. Additional MRI slightly increased the predictive value of cUS in severe WM changes. Sequential cUS in preterm infants is reliable for detecting WM changes and predicting favorable and severely abnormal outcome. Conventional and diffusion-weighted MRI sequences before term equivalent age in very preterm infants, suggested on cUS to have mild to moderately abnormal WM, do not seem to be warranted. (orig.)

  6. Differences in integrity of white matter and changes with training in spelling impaired children: a diffusion tensor imaging study.

    Science.gov (United States)

    Gebauer, D; Fink, A; Filippini, N; Johansen-Berg, H; Reishofer, G; Koschutnig, K; Kargl, R; Purgstaller, C; Fazekas, F; Enzinger, C

    2012-07-01

    While the functional correlates of spelling impairment have been rarely investigated, to our knowledge no study exists regarding the structural characteristics of spelling impairment and potential changes with interventions. Using diffusion tensor imaging at 3.0 T, we here therefore sought to investigate (a) differences between children with poor spelling abilities (training group and waiting group) and controls, and (b) the effects of a morpheme-based spelling intervention in children with poor spelling abilities on DTI parameters. A baseline comparison of white matter indices revealed significant differences between controls and spelling-impaired children, mainly located in the right hemisphere (superior corona radiata (SCR), posterior limb of internal capsule, superior longitudinal fasciculus). After 5 weeks of training, spelling ability improved in the training group, along with increases in fractional anisotropy and decreases of radial diffusivity in the right hemisphere compared to controls. In addition, significantly higher decreases of mean diffusivity in the right SCR for the spelling-impaired training group compared to the waiting group were observed. Our results suggest that spelling impairment is associated with differences in white-matter integrity in the right hemisphere. We also provide first indications that white matter changes occur during successful training, but this needs to be more specifically addressed in future research.

  7. Multimodal Voxel-Based Meta-Analysis of White Matter Abnormalities in Obsessive-Compulsive Disorder

    NARCIS (Netherlands)

    Radua, J.; Grau, M.; van den Heuvel, O.A.; Thiebaut de Schotten, M.; Stein, D.J.; Canales-Rodriguez, E.J.; Catani, M.; Mataix-Cols, D.

    2014-01-01

    White matter (WM) abnormalities have long been suspected in obsessive-compulsive disorder (OCD) but the available evidence has been inconsistent. We conducted the first multimodal meta-analysis of WM volume (WMV) and fractional anisotropy (FA) studies in OCD. All voxel-wise studies comparing WMV or

  8. Altered White Matter Integrity in Smokers Is Associated with Smoking Cessation Outcomes

    OpenAIRE

    Huang, Peiyu; Shen, Zhujing; Wang, Chao; Qian, Wei; Zhang, Huan; Yang, Yihong; Zhang, Minming

    2017-01-01

    Smoking is a significant cause of preventable mortality worldwide. Understanding the neural mechanisms of nicotine addiction and smoking cessation may provide effective targets for developing treatment strategies. In the present study, we explored whether smokers have white matter alterations and whether these alterations are related to cessation outcomes and smoking behaviors. Sixty-six smokers and thirty-seven healthy non-smokers were enrolled. The participants underwent magnetic resonance ...

  9. Supplier integration in product development: A matter of designing the project structure

    Directory of Open Access Journals (Sweden)

    Mike Danilovic

    2007-11-01

    Full Text Available In product development close collaboration between systems integrators and suppliers is important. The purpose of this article is to investigate the impact of the work breakdown structure (WBS and work packages (WPs in product development on the possibility of carrying through the strategy of supplier involvement into collaborative practice and to investigate how supplier involvement can be improved by altering the design of collaborative WBS and WP structures. Dependence Structure Matrix (DSM is introduced in order to analyse, visualise and manage interdependencies, in terms of information exchange between the systems integrator and supplier. This article shows how DSM can support the alternative design of integrated and collaborative WBS and integrated WPs following the logic of dependencies and the flow of information in order to support a strategy focusing on integration of suppliers on project and team level.

  10. Wavelength-Modulated Differential Photoacoustic (WM-DPA) imaging: a high dynamic range modality towards noninvasive diagnosis of cancer

    Science.gov (United States)

    Dovlo, Edem; Lashkari, Bahman; Choi, Sung soo Sean; Mandelis, Andreas

    2016-03-01

    This study explores wavelength-modulated differential photo-acoustic (WM-DPA) imaging for non-invasive early cancer detection via sensitive characterization of functional information such as hemoglobin oxygenation (sO2) levels. Well-known benchmarks of tumor formation such as angiogenesis and hypoxia can be addressed this way. While most conventional photo-acoustic imaging has almost entirely employed high-power pulsed lasers, frequency-domain photo-acoustic radar (FD-PAR) has seen significant development as an alternative technique. It employs a continuous wave laser source intensity-modulated and driven by frequency-swept waveforms. WM-DPA imaging utilizes chirp modulated laser beams at two distinct wavelengths for which absorption differences between oxy- and deoxygenated hemoglobin are minimum (isosbestic point, 805 nm) and maximum (680 nm) to simultaneously generate two signals detected using a standard commercial array transducer as well as a single-element transducer that scans the sample. Signal processing is performed using Lab View and Matlab software developed in-house. Minute changes in total hemoglobin concentration (tHb) and oxygenation levels are detectable using this method since background absorption is suppressed due to the out-of-phase modulation of the laser sources while the difference between the two signals is amplified, thus allowing pre-malignant tumors to become identifiable. By regulating the signal amplitude ratio and phase shift the system can be tuned to applications like cancer screening, sO2 quantification and hypoxia monitoring in stroke patients. Experimental results presented demonstrate WM-DPA imaging of sheep blood phantoms in comparison to single-wavelength FD-PAR imaging. Future work includes the functional PA imaging of small animals in vivo.

  11. Preliminary Concept of Operations for the Spent Fuel Management System--WM2017

    Energy Technology Data Exchange (ETDEWEB)

    Cumberland, Riley M [ORNL; Adeniyi, Abiodun Idowu [ORNL; Howard, Rob L [ORNL; Joseph III, Robert Anthony [ORNL; Jarrell, Joshua J [ORNL; Nutt, Mark [Argonne National Laboratory (ANL)

    2017-01-01

    The Nuclear Fuels Storage and Transportation Planning Project (NFST) within the U.S. Department of Energy s Office of Nuclear Energy is tasked with identifying, planning, and conducting activities to lay the groundwork for developing interim storage and transportation capabilities in support of an integrated waste management system. The system will provide interim storage for commercial spent nuclear fuel (SNF) from reactor sites and deliver it to a repository. The system will also include multiple subsystems, potentially including; one or more interim storage facilities (ISF); one or more repositories; facilities to package and/or repackage SNF; and transportation systems. The project team is analyzing options for an integrated waste management system. To support analysis, the project team has developed a Concept of Operations document that describes both the potential integrated system and inter-dependencies between system components. The goal of this work is to aid systems analysts in the development of consistent models across the project, which involves multiple investigators. The Concept of Operations document will be updated periodically as new developments emerge. At a high level, SNF is expected to travel from reactors to a repository. SNF is first unloaded from reactors and placed in spent fuel pools for wet storage at utility sites. After the SNF has cooled enough to satisfy loading limits, it is placed in a container at reactor sites for storage and/or transportation. After transportation requirements are met, the SNF is transported to an ISF to store the SNF until a repository is developed or directly to a repository if available. While the high level operation of the system is straightforward, analysts must evaluate numerous alternative options. Alternative options include the number of ISFs (if any), ISF design, the stage at which SNF repackaging occurs (if any), repackaging technology, the types of containers used, repository design, component

  12. Disrupted topological properties of brain white matter networks in left temporal lobe epilepsy: a diffusion tensor imaging study.

    Science.gov (United States)

    Xu, Y; Qiu, S; Wang, J; Liu, Z; Zhang, R; Li, S; Cheng, L; Liu, Z; Wang, W; Huang, R

    2014-10-24

    Mesial temporal lobe epilepsy (mTLE) is the most common drug-refractory focal epilepsy in adults. Although previous functional and morphological studies have revealed abnormalities in the brain networks of mTLE, the topological organization of the brain white matter (WM) networks in mTLE patients is still ambiguous. In this study, we constructed brain WM networks for 14 left mTLE patients and 22 age- and gender-matched normal controls using diffusion tensor tractography and estimated the alterations of network properties in the mTLE brain networks using graph theoretical analysis. We found that networks for both the mTLE patients and the controls exhibited prominent small-world properties, suggesting a balanced topology of integration and segregation. However, the brain WM networks of mTLE patients showed a significant increased characteristic path length but significant decreased global efficiency, which indicate a disruption in the organization of the brain WM networks in mTLE patients. Moreover, we found significant between-group differences in the nodal properties in several brain regions, such as the left superior temporal gyrus, left hippocampus, the right occipital and right temporal cortices. The robustness analysis showed that the results were likely to be consistent for the networks constructed with different definitions of node and edge weight. Taken together, our findings may suggest an adverse effect of epileptic seizures on the organization of large-scale brain WM networks in mTLE patients. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Structural white-matter connections mediating distinct behavioral components of spatial neglect in right brain-damaged patients.

    Science.gov (United States)

    Vaessen, Maarten J; Saj, Arnaud; Lovblad, Karl-Olof; Gschwind, Markus; Vuilleumier, Patrik

    2016-04-01

    Spatial neglect is a neuropsychological syndrome in which patients fail to perceive and orient to stimuli located in the space contralateral to the lesioned hemisphere. It is characterized by a wide heterogeneity in clinical symptoms which can be grouped into distinct behavioral components correlating with different lesion sites. Moreover, damage to white-matter (WM) fiber tracts has been suggested to disconnect brain networks that mediate different functions associated with spatial cognition and attention. However, it remains unclear what WM pathways are associated with functionally dissociable neglect components. In this study we examined nine patients with a focal right hemisphere stroke using a series of neuropsychological tests and diffusion tensor imaging (DTI) in order to disentangle the role of specific WM pathways in neglect symptoms. First, following previous work, the behavioral test scores of patients were factorized into three independent components reflecting perceptual, exploratory, and object-centered deficits in spatial awareness. We then examined the structural neural substrates of these components by correlating indices of WM integrity (fractional anisotropy) with the severity of deficits along each profile. Several locations in the right parietal and frontal WM correlated with neuropsychological scores. Fiber tracts projecting from these locations indicated that posterior parts of the superior longitudinal fasciculus (SLF), as well as nearby callosal fibers connecting ipsilateral and contralateral parietal areas, were associated with perceptual spatial deficits, whereas more anterior parts of SLF and inferior fronto-occipital fasciculus (IFOF) were predominantly associated with object-centered deficits. In addition, connections between frontal areas and superior colliculus were found to be associated with the exploratory deficits. Our results provide novel support to the view that neglect may result from disconnection lesions in distributed

  14. The Seismic Broad Band Western Mediterranean (wm) Network and the Obs Fomar Pool: Current state and Obs activities.

    Science.gov (United States)

    Pazos, Antonio; Davila, Jose Martin; Buforn, Elisa; Bezzeghoud, Mourad; Harnafi, Mimoun; Mattesini, Mauricio; Caldeira, Bento; Hanka, Winfried; El Moudnib, Lahcen; Strollo, Angelo; Roca, Antoni; Lopez de Mesa, Mireya; Dahm, Torsten; Cabieces, Roberto

    2016-04-01

    The Western Mediterranean (WM) seismic network started in 1996 as an initiative of the Royal Spanish Navy Observatory (ROA) and the Universidad Complutense de Madrid (UCM), with the collaboration of the GeoForschungsZentrum (GFZ) of Potsdam. A first broad band seismic station (SFUC) was installed close to Cádiz (South Spain). Since then, additional stations have been installed in the Ibero-Moghrebian region. In 2005, the "WM" code was assigned by the FDSN and new partners were jointed: Evora University (UEVO, Portugal), the Scientifique Institute of Rabat (ISRABAT, Morocco), and GFZ. Now days, the WM network is composed by 15 BB stations, all of them with Streckaisen STS-2 or STS-2.5 sensors, Quanterra or Earthdata digitizers and SeiscomP. Most them have co-installed a permanent geodetic GPS stations, and some them also have an accelerometer. There are 10 stations deployed in Spanish territory (5 in the Iberian peninsula, 1 in Balearic islands and 4 in North Africa Spanish places) with VSAT or Internet communications, 2 in Portugal (one of them without real time), and 3 in Morocco (2 VSAT and 1 ADSL). Additionally, 2 more stations (one in South Spain and one in Morocco) will be installed along this year. Additionally ROA has deployed a permanent real time VBB (CMG-3T: 360s) station at the Alboran Island. Due to the fact that part of the seismic activity is located at marine areas, and also because of the poor geographic azimuthal coverage at some zones provided by the land stations (specially in the SW of the San Vicente Cape area), ROA and UCM have acquired six broad band "LOBSTERN" OBS, manufactured by KUM (Kiel, Germany), conforming the OBS FOMAR pool. Three of them with CMG-40T sensor and the other with Trillium 120. These OBS were deployed along the Gibraltar strait since January to November 2014 to study the microseismicity in the Gibraltar strait area. In September 2015 FOMAR network has been deployed in SW of the San Vicente Cape for 8 months as a part of

  15. Web technology in the separation of strontium and cesium from INEL-ICPP radioactive acid waste (WM-185)

    International Nuclear Information System (INIS)

    Bray, L.A.; Brown, G.N.

    1995-01-01

    Strontium and cesium were successfully removed from radioactive acidic waste (WM-185) at the Idaho National Engineering Laboratory, Idaho Chemical Processing Plant (ICPP), with web technology from 3M and IBC Advanced Technologies, Inc. (IBC). A technical team from Pacific Northwest Laboratory, ICPP, 3M and IBC conducted a very successful series of experiments from August 15 through 18, 1994. The ICPP, Remote Analytical Laboratory, Idaho Falls, Idaho, provided the hot cell facilities and staff to complete these milestone experiments. The actual waste experiments duplicated the initial 'cold' simulated waste results and confirmed the selective removal provided by ligand-particle web technology

  16. Integration of white matter network is associated with interindividual differences in psychologically mediated placebo response in migraine patients.

    Science.gov (United States)

    Liu, Jixin; Ma, Shaohui; Mu, Junya; Chen, Tao; Xu, Qing; Dun, Wanghuan; Tian, Jie; Zhang, Ming

    2017-10-01

    Individual differences of brain changes of neural communication and integration in the modular architecture of the human brain network exist for the repeated migraine attack and physical or psychological stressors. However, whether the interindividual variability in the migraine brain connectome predicts placebo response to placebo treatment is still unclear. Using DTI and graph theory approaches, we systematically investigated the topological organization of white matter networks in 71 patients with migraine without aura (MO) and 50 matched healthy controls at three levels: global network measure, nodal efficiency, and nodal intramodule/intermodule efficiency. All patients participated in an 8-week sham acupuncture treatment to induce analgesia. In our results, 30% (n = 21) of patients had 50% change in migraine days from baseline after placebo treatment. At baseline, abnormal increased network integration was found in MO patients as compared with the HC group, and the increased global efficiency before starting clinical treatment was associated with their following placebo response. For nodal efficiency, significantly increased within-subnetwork nodal efficiency and intersubnetwork connectivity of the hippocampus and middle frontal gyrus in patients' white matter network were correlated with the responses of follow-up placebo treatment. Our findings suggested that the trait-like individual differences in pain-related maladaptive stress interfered with and diminished the capacity of chronic pain modulation differently, and the placebo response for treatment could be predicted from a prior white matter network modular structure in migraineurs. Hum Brain Mapp 38:5250-5259, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  17. The effects of the serotonin transporter polymorphism and age on frontal white matter integrity in healthy adult women.

    Directory of Open Access Journals (Sweden)

    Rune eJonassen

    2012-02-01

    Full Text Available Studies of populations at genetic risk have the potential to explore the underlying structural and functional mechanisms in the development of psychological disorders. The polymorphic region (5-HTTLPR in the serotonin transporter gene (SLC6A4 has been associated with major depression (Caspi et al., 2003. In healthy women, variation in the human brain white matter microstructure integrity in the uncinate fascicule (UF has been suggested as an endophenotypes in the development of major depression (MDD. Pacheco et al. (2009 found a unique effect of age and 5-HTTLPR within the left frontal UF. The present study examined whether these associations persist along the adult life span. Thirty-seven right-handed healthy women between 21 and 61 years of age were invited for a diffusion MRI study. The functional polymorphism 5-HTTLPR located in the promoter region of the SLC6A4 gene was genotyped using polymerase chain reaction (PCR. Fractional anisotropy (FA was generated for the UF based on Tract-Based Spatial Statistics (TBSS. Models of emotion regulation circuitry suggest that working memory is important in conscious emotion regulation (Price and Drevets, 2010. To explore if 5-HTTLPR is related to this aspects of emotion processing, a working memory pathway, the superior longitudinal fascicule (SLF was included. The results demonstrate that age may explain the hypothesized association between 5-HTTLPR and frontal uncinate fascicule white matter integrity in healthy adult women. Both white matter changes associated with the aging process and those associated with growth and development may explain why the earlier reported unique effects of genotype in frontal UF FA do not persist into adulthood.

  18. Economic aspects of thermal treatment of solid waste in a sustainable WM system

    Energy Technology Data Exchange (ETDEWEB)

    Massarutto, Antonio

    2015-03-15

    Highlights: • Provides a comprehensive review of the applied economic literature dedicated to WtE. • Offers a detailed discussion of the main assumptions that characterize alternative positions. • Highlights the most robust achievements obtained by the applied economic research in this field. • Compares economic and non-economic valuation techniques. - Abstract: This paper offers a systematic review of the literature of the last 15 years, which applies economic analysis and theories to the issue of combustion of solid waste. Waste incineration has attracted the interest of economists in the first place concerning the comparative assessment of waste management options, with particular reference to external costs and benefits. A second important field of applied economic research concerns the market failures associated with the provision of thermal treatment of waste, that justify some deviation from the standard competitive market model. Our analysis discusses the most robust achievements and the more controversial areas. All in all, the economic perspective seems to confirm the desirability of assigning a prominent role to thermal treatments in an integrated waste management strategy. Probably the most interesting original contribution it has to offer concerns the refusal of categorical assumptions and too rigid priority ladders, emphasizing instead the need to consider site-specific circumstances that may favor one or another solution.

  19. Economic aspects of thermal treatment of solid waste in a sustainable WM system

    International Nuclear Information System (INIS)

    Massarutto, Antonio

    2015-01-01

    Highlights: • Provides a comprehensive review of the applied economic literature dedicated to WtE. • Offers a detailed discussion of the main assumptions that characterize alternative positions. • Highlights the most robust achievements obtained by the applied economic research in this field. • Compares economic and non-economic valuation techniques. - Abstract: This paper offers a systematic review of the literature of the last 15 years, which applies economic analysis and theories to the issue of combustion of solid waste. Waste incineration has attracted the interest of economists in the first place concerning the comparative assessment of waste management options, with particular reference to external costs and benefits. A second important field of applied economic research concerns the market failures associated with the provision of thermal treatment of waste, that justify some deviation from the standard competitive market model. Our analysis discusses the most robust achievements and the more controversial areas. All in all, the economic perspective seems to confirm the desirability of assigning a prominent role to thermal treatments in an integrated waste management strategy. Probably the most interesting original contribution it has to offer concerns the refusal of categorical assumptions and too rigid priority ladders, emphasizing instead the need to consider site-specific circumstances that may favor one or another solution

  20. 'Trust and teamwork matter': community health workers' experiences in integrated service delivery in India.

    Science.gov (United States)

    Mishra, Arima

    2014-01-01

    A comprehensive and integrated approach to strengthen primary health care has been the major thrust of the National Rural Health Mission (NRHM) that was launched in 2005 to revamp India's rural public health system. Though the logic of horizontal and integrated health care to strengthen health systems has long been acknowledged at policy level, empirical evidence on how such integration operates is rare. Based on recent (2011-2012) ethnographic fieldwork in Odisha, India, this article discusses community health workers' experiences in integrated service delivery through village-level outreach sessions within the NRHM. It shows that for health workers, the notion of integration goes well beyond a technical lens of mixing different health services. Crucially, they perceive 'teamwork' and 'building trust with the community' (beyond trust in health services) to be critical components of their practice. However, the comprehensive NRHM primary health care ideology - which the health workers espouse - is in constant tension with the exigencies of narrow indicators of health system performance. Our ethnography shows how monitoring mechanisms, the institutionalised privileging of statistical evidence over field-based knowledge and the highly hierarchical health bureaucratic structure that rests on top-down communications mitigate efforts towards sustainable health system integration.

  1. Evaluating the relationship between white matter integrity, cognition, and varieties of video game learning.

    Science.gov (United States)

    Ray, Nicholas R; O'Connell, Margaret A; Nashiro, Kaoru; Smith, Evan T; Qin, Shuo; Basak, Chandramallika

    2017-01-01

    Many studies are currently researching the effects of video games, particularly in the domain of cognitive training. Great variability exists among video games however, and few studies have attempted to compare different types of video games. Little is known, for instance, about the cognitive processes or brain structures that underlie learning of different genres of video games. To examine the cognitive and neural underpinnings of two different types of game learning in order to evaluate their common and separate correlates, with the hopes of informing future intervention research. Participants (31 younger adults and 31 older adults) completed an extensive cognitive battery and played two different genres of video games, one action game and one strategy game, for 1.5 hours each. DTI scans were acquired for each participant, and regional fractional anisotropy (FA) values were extracted using the JHU atlas. Behavioral results indicated that better performance on tasks of working memory and perceptual discrimination was related to enhanced learning in both games, even after controlling for age, whereas better performance on a perceptual speed task was uniquely related with enhanced learning of the strategy game. DTI results indicated that white matter FA in the right fornix/stria terminalis was correlated with action game learning, whereas white matter FA in the left cingulum/hippocampus was correlated with strategy game learning, even after controlling for age. Although cognition, to a large extent, was a common predictor of both types of game learning, regional white matter FA could separately predict action and strategy game learning. Given the neural and cognitive correlates of strategy game learning, strategy games may provide a more beneficial training tool for adults suffering from memory-related disorders or declines in processing speed, particularly older adults.

  2. Disruption of Accumbens and Thalamic White Matter Connectivity Revealed by Diffusion Tensor Tractography in Young Men with Genetic Risk for Obesity

    Directory of Open Access Journals (Sweden)

    Gaia Olivo

    2018-02-01

    Full Text Available Background: Neurovascular coupling is associated with white matter (WM structural integrity, and it is regulated by specific subtypes of dopaminergic receptors. An altered activity of such receptors, highly expressed in reward-related regions, has been reported in carriers of obesity-risk alleles of the fat mass and obesity associated (FTO gene. Among the reward-related regions, the thalamus and the nucleus accumbens are particularly vulnerable to blood pressure dysregulation due to their peculiar anatomo-vascular characteristics, and have been consistently reported to be altered in early-stage obesity. We have thus hypothesized that a disruption in thalamus and nucleus accumbens WM microstructure, possibly on neurovascular basis, could potentially be a predisposing factor underlying the enhanced risk for obesity in the risk-allele carriers.Methods: We have tested WM integrity in 21 male participants genotyped on the FTO risk single nucleotide polymorphisms (SNP rs9939609, through a deterministic tractography analysis. Only homozygous participants (9 AA, 12 TT were included. 11 tracts were selected and categorized as following according to our hypothesis: “risk tracts”, “obesity-associated tracts”, and a control tract (forcpes major. We investigated whether an association existed between genotype, body mass index (BMI and WM microstructural integrity in the “risk-tracts” (anterior thalamic radiation and accumbofrontal fasciculus compared to other tracts. Moreover, we explored whether WM diffusivity could be related to specific personality traits in terms of punishment and reward sensitivity, as measure by the BIS/BAS questionnaire.Results: An effect of the genotype and an interaction effect of genotype and BMI were detected on the fractional anisotropy (FA of the “risk tracts”. Correlations between WM diffusivity parameters and measures of punishment and reward sensitivity were also detected in many WM tracts of both networks

  3. Attention, working memory, and phenomenal experience of WM content: memory levels determined by different types of top-down modulation.

    Science.gov (United States)

    Jacob, Jane; Jacobs, Christianne; Silvanto, Juha

    2015-01-01

    What is the role of top-down attentional modulation in consciously accessing working memory (WM) content? In influential WM models, information can exist in different states, determined by allocation of attention; placing the original memory representation in the center of focused attention gives rise to conscious access. Here we discuss various lines of evidence indicating that such attentional modulation is not sufficient for memory content to be phenomenally experienced. We propose that, in addition to attentional modulation of the memory representation, another type of top-down modulation is required: suppression of all incoming visual information, via inhibition of early visual cortex. In this view, there are three distinct memory levels, as a function of the top-down control associated with them: (1) Nonattended, nonconscious associated with no attentional modulation; (2) attended, phenomenally nonconscious memory, associated with attentional enhancement of the actual memory trace; (3) attended, phenomenally conscious memory content, associated with enhancement of the memory trace and top-down suppression of all incoming visual input.

  4. MAJAS DAN GAYA KALIMAT PUISI “TUHAN, KITA BEGITU DEKAT” KARYA ABDULHADI W.M. DAN DIMENSI SUFISTIKNYA

    Directory of Open Access Journals (Sweden)

    Ali Imron Al-Ma’ruf

    2011-06-01

    Kajian ini menggunakan metode penelitian kualitatif deskriptif dengan mendasarkan pada kerangka berpikir induktif. Pengumpulan data dilakukan dengan teknik pustaka. Analisis data dilakukan dengan metode contens analysis dan pembacaan model semiotik yakni pembacaan heuristik dan hermeneutik dengan pendekatan teori Semiotik. Hasil kajian ini adalah: (1 style ’gaya bahasa’ puisi “Tuhan, Kita Begitu Dekat” karya Abdulhadi W.M. memiliki kekhasan dan keunikan (ideosyncrasy yang berbeda dengan karya penyair lain. Kekhasan style puisi tersebut terlihat antara lain pada majas dan gaya kalimat. Majas dalam puisi tersebut didominasi oleh metafora, simile, dan hiperbola. Adapun gaya kalimat puisi itu didominasi oleh gaya kalimat implisit dengan melesapkan beberapa bagian dalam kalimat demi efektivitas dan untuk menciptakan daya ekspresif dalam rangka mencapai efek estetis. Style Abdulhadi W.M. dalam puisi itu menunjukkan kekhasan dan keunikan sebagai wujud individuasi penyair; (2 Puisi karya Abdulhadi W.M. itu mengungkapkan dimensi sufistik. Puisi itu menyiratkan gagasan tasawuf Wahdatul Wujud, yang melukiskan berpadunya eksistensi manusia dengan eksistensi Tuhan, berpadunya dimensi insaniyah dengan dimensi Ilahiyah, bersatunya makhluk dengan Khalik. Itulah esensi puisi itu yakni hakikat dan ma’rifat dalam tradisi tasawuf yang dianut para sufi. Sekaligus puisi itu menunjukkan bahwa Abdulhadi W.M. merupakan salah satu sastrawan sufistik Indonesia. Kata Kunci: stilistika, majas, gaya kalimat, puisi “Tuhan, Begitu Dekat”, sufistik

  5. Frontal White Matter Damage Impairs Response Inhibition in Children Following Traumatic Brain Injury

    Science.gov (United States)

    Lipszyc, Jonathan; Levin, Harvey; Hanten, Gerri; Hunter, Jill; Dennis, Maureen; Schachar, Russell

    2014-01-01

    Inhibition, the ability to suppress inappropriate cognitions or behaviors, can be measured using computer tasks and questionnaires. Inhibition depends on the frontal cortex, but the role of the underlying white matter (WM) is unclear. We assessed the specific impact of frontal WM damage on inhibition in 29 children with moderate-to-severe traumatic brain injury (15 with and 14 without frontal WM damage), 21 children with orthopedic injury, and 29 population controls. We used the Stop Signal Task to measure response inhibition, the Behavior Rating Inventory of Executive Function to assess everyday inhibition, and T2 fluid-attenuated inversion recovery magnetic resonance imaging to identify lesions. Children with frontal WM damage had impaired response inhibition compared with all other groups and poorer everyday inhibition than the orthopedic injury group. Frontal WM lesions most often affected the superior frontal gyrus. These results provide evidence for the critical role of frontal WM in inhibition. PMID:24618405

  6. Individualized prediction of schizophrenia based on the whole-brain pattern of altered white matter tract integrity.

    Science.gov (United States)

    Chen, Yu-Jen; Liu, Chih-Min; Hsu, Yung-Chin; Lo, Yu-Chun; Hwang, Tzung-Jeng; Hwu, Hai-Gwo; Lin, Yi-Tin; Tseng, Wen-Yih Isaac

    2018-01-01

    A schizophrenia diagnosis relies on characteristic symptoms identified by trained physicians, and is thus prone to subjectivity. This study developed a procedure for the individualized prediction of schizophrenia based on whole-brain patterns of altered white matter tract integrity. The study comprised training (108 patients and 144 controls) and testing (60 patients and 60 controls) groups. Male and female participants were comparable in each group and were analyzed separately. All participants underwent diffusion spectrum imaging of the head, and the data were analyzed using the tract-based automatic analysis method to generate a standardized two-dimensional array of white matter tract integrity, called the connectogram. Unique patterns in the connectogram that most accurately identified schizophrenia were systematically reviewed in the training group. Then, the diagnostic performance of the patterns was individually verified in the testing group by using receiver-operating characteristic curve analysis. The performance was high in men (accuracy = 0.85) and satisfactory in women (accuracy = 0.75). In men, the pattern was located in discrete fiber tracts, as has been consistently reported in the literature; by contrast, the pattern was widespread over all tracts in women. These distinct patterns suggest that there is a higher variability in the microstructural alterations in female patients than in male patients. The individualized prediction of schizophrenia is feasible based on the different whole-brain patterns of tract integrity. The optimal masks and their corresponding regions in the fiber tracts could serve as potential imaging biomarkers for schizophrenia. Hum Brain Mapp 39:575-587, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  7. White matter tract integrity is associated with antidepressant response to lurasidone in bipolar depression.

    Science.gov (United States)

    Lan, Martin J; Rubin-Falcone, Harry; Motiwala, Fatima; Chen, Ying; Stewart, Jonathan W; Hellerstein, David J; Mann, J John; McGrath, Patrick J

    2017-09-01

    Patients with bipolar disorder spend the most time in the depressed phase, and that phase is associated with the most morbidity and mortality. Treatment of bipolar depression lacks a test to determine who will respond to treatment. White matter disruptions have been found in bipolar disorder. Previous reports suggest that white matter disruptions may be associated with resistance to antidepressant medication, but this has never been investigated in a prospective study using a Food and Drug Administration (FDA)-approved medication. Eighteen subjects with bipolar disorder who were in a major depressive episode and off all medications were recruited. Magnetic resonance imaging was acquired using a 64-direction diffusion tensor imaging sequence on a 3T scanner. Subjects were treated with 8 weeks of open-label lurasidone. The Montgomrey-Asberg Depression Rating Scale (MADRS) was completed weekly. Tract-Based Spatial Statistics were utilized to perform a regression analysis of fractional anisotropy (FA) data with treatment outcome as assessed by percent change in MADRS as a regressor while controlling for age and sex, using a threshold of P (threshold-free cluster enhancement-corrected) bipolar disorder were associated with poorer antidepressant response to lurasidone. The disruptions may potentially indicate treatment with a different antidepressant medication class. These results are limited by the open-label study design, sample size and lack of a healthy control group. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Disrupted white matter structure underlies cognitive deficit in hypertensive patients

    International Nuclear Information System (INIS)

    Li, Xin; Ma, Chao; Zhang, Junying; Chen, Yaojing; Zhang, Zhanjun; Sun, Xuan; Chen, Kewei

    2016-01-01

    Hypertension is considered a risk factor of cognitive impairments and could result in white matter changes. Current studies on hypertension-related white matter (WM) changes focus only on regional changes, and the information about global changes in WM structure network is limited. We assessed the cognitive function in 39 hypertensive patients and 37 healthy controls with a battery of neuropsychological tests. The WM structural networks were constructed by utilizing diffusion tensor tractography and calculated topological properties of the networks using a graph theoretical method. The direct and indirect correlations among cognitive impairments, brain WM network disruptions and hypertension were analyzed with structural equation modelling (SEM). Hypertensive patients showed deficits in executive function, memory and attention compared with controls. An aberrant connectivity of WM networks was found in the hypertensive patients (P Eglob = 0.005, P Lp = 0.005), especially in the frontal and parietal regions. Importantly, SEM analysis showed that the decline of executive function resulted from aberrant WM networks in hypertensive patients (p = 0.3788, CFI = 0.99). These results suggest that the cognitive decline in hypertensive patients was due to frontal and parietal WM disconnections. Our findings highlight the importance of brain protection in hypertension patients. (orig.)

  9. Making Communication Matter: Integrating Instruction, Projects and Assignments to Teach Writing and Design

    Science.gov (United States)

    Riddell, William T.; Courtney, Jennifer; Constans, Eric; Dahm, Kevin; Harvey, Roberta; von Lockette, Paris

    2010-01-01

    An integrated technical writing and design course has been developed at Rowan University. This course was developed using aspects of project-based learning and recent discussions about design education, as well as pedagogical approaches from the write-to-learn and the writing in the disciplines (WID) movements. The result is a course where the…

  10. 75 FR 24742 - In the Matter of Certain Large Scale Integrated Circuit Semiconductor Chips and Products...

    Science.gov (United States)

    2010-05-05

    ... Semiconductor, Xiqing Integrated Semiconductor, Manufacturing Site, No. 15 Xinghua Road, Xiqing Economic... Malaysia Sdn. Bhd., NO. 2 Jalan SS 8/2, Free Industrial Zone, Sungai Way, 47300 Petaling Jaya, Selengor, Malaysia. Freescale Semiconductor Pte. Ltd., 7 Changi South Street 2, 03-00, Singapore 486415. Freescale...

  11. Content and carbon stocks in labile and recalcitrant organic matter of the soil under crop-livestock integration in Cerrado

    Directory of Open Access Journals (Sweden)

    Itaynara Batista

    2013-12-01

    Full Text Available The study of organic matter and its compartments and their relationship with management, aims to develop strategies for increasing their levels in soils and better understanding of its dynamics. This work aimed to evaluate the fractions of soil organic matter and their carbon stocks in different soil cover system in crop-livestock integration and native Cerrado vegetation. The study was conducted at the farm Cabeceira, Maracajú – MS, sample area have the following history: soybean/corn + brachiaria/cotton/oat + pasture/soybean/formation of pasture/grazing, sampling was carried out in two seasons, dry (May/2009 and rainy (March 2010, in the dry season, crops present were: pasture, corn and cotton + brachiaria and in the rainy season were corn, cotton and soybeans, so the areas in the two evaluation periods were: pasture / maize + brachiaria / cotton, cotton / soybean area and a native of Savanna. Was performed to determine the exchangeable cations, particle size analysis, bulk density, organic carbon, particle size fractionation of organic matter of the soil with the quantification of particulate organic carbon (POC and organic carbon associated with minerals (OCam. Was also quantified the carbon stock and size fractions. The area of pasture / maize showed higher carbon stock in the particulate fraction in the topsoil. The area of cotton / soy due to its lower clay, showed the greatest loss of carbon. Because of the areas have the same history, the stock of more recalcitrant fraction was not sensitive to variations in coverage. The POC fraction appears more sensitive to different soil covers and seasonality.

  12. Analyses of disruption of cerebral white matter integrity in schizophrenia with MR diffusion tensor fiber tracking method

    International Nuclear Information System (INIS)

    Yamamoto, Utako; Kobayashi, Tetsuo; Kito, Shinsuke; Koga, Yoshihiko

    2010-01-01

    We have analyzed cerebral white matter using magnetic resonance diffusion tensor imaging (MR-DTI) to measure the diffusion anisotropy of water molecules. The goal of this study is the quantitative evaluation of schizophrenia. Diffusion tensor images are acquired for patients with schizophrenia and healthy comparison subjects, group-matched for age, sex, and handedness. Fiber tracking is performed on the superior longitudinal fasciculus for the comparison between the patient and comparison groups. We have analysed and compared the cross-sectional area on the starting coronal plane and the mean and standard deviation of the fractional anisotropy and the apparent diffusion coefficient along fibers in the right and left hemispheres. In the right hemisphere, the cross-sectional areas in patient group are significantly smaller than those in the comparison group. Furthermore, in the comparison group, the cross-sectional areas in the right hemisphere are significantly larger than those in the left hemisphere, whereas there is no significant difference in the patient group. These results suggest that we may evaluate the disruption in white matter integrity in schizophrenic patients quantitatively by comparing the cross-sectional area of the superior longitudinal fasciculus in the right and left hemispheres. (author)

  13. Does integration matter? A holistic model for building community resilience in Pakistan.

    Science.gov (United States)

    Kanta Kafle, Shesh

    2017-01-01

    This paper analyses an integrated communitybased risk reduction model adopted by the Pakistan Red Crescent. The paper analyses the model's constructs and definitions, and provides a conceptual framework and a set of practical recommendations for building community resilience. The study uses the process of outcome-based resilience index to assess the effectiveness of the approach. The results indicate that the integrated programming approach is an effective way to build community resilience as it offers a number of tangible and longlasting benefits, including effective and efficient service delivery, local ownership, sustainability of results, and improved local resilience with respect to the shock and stress associated with disaster. The paper also outlines a set of recommendations for the effective and efficient use of the model for building community resilience in Pakistan.

  14. The perspective matters! Multisensory integration in ego-centric reference frames determines full body ownership

    Directory of Open Access Journals (Sweden)

    Valeria Ivanova Petkova

    2011-03-01

    Full Text Available Recent advances in experimental science have made it possible to investigate the perceptual processes involved in generating a sense of owning an entire body. This is achieved by full-body ownership illusions which make use of specific patterns of visual and somatic stimuli integration. Here we investigate the fundamental question of the reference frames used in the process of attributing an entire body to the self. We quantified the strength of the body-swap illusion in conditions where the participants were observing this artificial body from the perspective of the first or third person. Consistent results from subjective reports and physiological recordings show that the first person visual perspective is critical for the induction of this full-body ownership illusion. This demonstrates that the multisensory integration processes producing the sense of corporeal self operates in an ego-centric reference frame.

  15. The Perspective Matters! Multisensory Integration in Ego-Centric Reference Frames Determines Full-Body Ownership

    Science.gov (United States)

    Petkova, Valeria I.; Khoshnevis, Mehrnoush; Ehrsson, H. Henrik

    2011-01-01

    Recent advances in experimental science have made it possible to investigate the perceptual processes involved in generating a sense of owning an entire body. This is achieved by full-body ownership illusions which make use of specific patterns of visual and somatic stimuli integration. Here we investigate the fundamental question of the reference frames used in the process of attributing an entire body to the self. We quantified the strength of the body-swap illusion in conditions where the participants were observing this artificial body from the perspective of the first or third person. Consistent results from subjective reports and physiological recordings show that the first person visual perspective is critical for the induction of this full-body ownership illusion. This demonstrates that the multisensory integration processes producing the sense of corporeal self operates in an ego-centric reference frame. PMID:21687436

  16. Least Square Fast Learning Network for modeling the combustion efficiency of a 300WM coal-fired boiler.

    Science.gov (United States)

    Li, Guoqiang; Niu, Peifeng; Wang, Huaibao; Liu, Yongchao

    2014-03-01

    This paper presents a novel artificial neural network with a very fast learning speed, all of whose weights and biases are determined by the twice Least Square method, so it is called Least Square Fast Learning Network (LSFLN). In addition, there is another difference from conventional neural networks, which is that the output neurons of LSFLN not only receive the information from the hidden layer neurons, but also receive the external information itself directly from the input neurons. In order to test the validity of LSFLN, it is applied to 6 classical regression applications, and also employed to build the functional relation between the combustion efficiency and operating parameters of a 300WM coal-fired boiler. Experimental results show that, compared with other methods, LSFLN with very less hidden neurons could achieve much better regression precision and generalization ability at a much faster learning speed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. The Left, The Better: White-Matter Brain Integrity Predicts Foreign Language Imitation Ability.

    Science.gov (United States)

    Vaquero, Lucía; Rodríguez-Fornells, Antoni; Reiterer, Susanne M

    2017-08-01

    Speech imitation is crucial for language acquisition and second-language learning. Interestingly, large individual differences regarding the ability in imitating foreign-language sounds have been observed. The origin of this interindividual diversity remains unknown, although it might be partially explained by structural predispositions. Here we correlated white-matter structural properties of the arcuate fasciculus (AF) with the performance of 52 German-speakers in a Hindi sentence- and word-imitation task. First, a manual reconstruction was performed, permitting us to extract the mean values along the three branches of the AF. We found that a larger lateralization of the AF volume toward the left hemisphere predicted the performance of our participants in the imitation task. Second, an automatic reconstruction was carried out, allowing us to localize the specific region within the AF that exhibited the largest correlation with foreign language imitation. Results of this reconstruction also showed a left lateralization trend: greater fractional anisotropy values in the anterior half of the left AF correlated with the performance in the Hindi-imitation task. From the best of our knowledge, this is the first time that foreign language imitation aptitude is tested using a more ecological imitation task and correlated with DTI tractography, using both a manual and an automatic method. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  18. Changes in Parahippocampal White Matter Integrity in Amnestic Mild Cognitive Impairment: A Diffusion Tensor Imaging Study

    Directory of Open Access Journals (Sweden)

    E. J. Rogalski

    2009-01-01

    Full Text Available In the present study, changes in the parahippocampal white matter (PWM, in the region that includes the perforant path, were investigated, in vivo, in 14 individuals with amnestic mild cognitive impairment (aMCI compared to 14 elderly controls with no cognitive impairment (NCI. For this purpose, (1 volumetry; (2 diffusion tensor imaging (DTI derived measures of mean diffusivity (MD and fractional anisotropy (FA; and (3 tractography were used. In addition, regression models were utilized to examine the association of PWM measurements with memory decline. The results from this study confirm previous findings in our laboratory and others, showing that compared to controls, individuals with aMCI have PWM volume loss. In addition to volume reduction, participants with aMCI demonstrated a significant increase in MD, but no difference in FA, both in the PWM region and in fibers modeled to pass through the PWM region. Further, the DTI metric of MD was associated with declarative memory performance, suggesting it may be a sensitive marker for memory dysfunction. These results indicate that there is general tissue loss and degradation (decreased volume; increased MD in individuals with aMCI compared to older people with normal cognitive function. However, the microstructural organization of remaining fibers, as determined by measures of anisotropic diffusion, is not significantly different from that of controls.

  19. Integrating plant litter quality, soil organic matter stabilization, and the carbon saturation concept.

    Science.gov (United States)

    Castellano, Michael J; Mueller, Kevin E; Olk, Daniel C; Sawyer, John E; Six, Johan

    2015-09-01

    Labile, 'high-quality', plant litters are hypothesized to promote soil organic matter (SOM) stabilization in mineral soil fractions that are physicochemically protected from rapid mineralization. However, the effect of litter quality on SOM stabilization is inconsistent. High-quality litters, characterized by high N concentrations, low C/N ratios, and low phenol/lignin concentrations, are not consistently stabilized in SOM with greater efficiency than 'low-quality' litters characterized by low N concentrations, high C/N ratios, and high phenol/lignin concentrations. Here, we attempt to resolve these inconsistent results by developing a new conceptual model that links litter quality to the soil C saturation concept. Our model builds on the Microbial Efficiency-Matrix Stabilization framework (Cotrufo et al., 2013) by suggesting the effect of litter quality on SOM stabilization is modulated by the extent of soil C saturation such that high-quality litters are not always stabilized in SOM with greater efficiency than low-quality litters. © 2015 John Wiley & Sons Ltd.

  20. Early microstructural white matter changes in patients with HIV: A diffusion tensor imaging study

    Directory of Open Access Journals (Sweden)

    Stubbe-Drger Bianca

    2012-05-01

    Full Text Available Abstract Background Previous studies have reported white matter (WM brain alterations in asymptomatic patients with human immunodeficiency virus (HIV. Methods We compared diffusion tensor imaging (DTI derived WM fractional anisotropy (FA between HIV-patients with and without mild macroscopic brain lesions determined using standard magnetic resonance imaging (MRI. We furthermore investigated whether WM alterations co-occurred with neurocognitive deficits and depression. We performed structural MRI and DTI for 19 patients and 19 age-matched healthy controls. Regionally-specific WM integrity was investigated using voxel-based statistics of whole-brain FA maps and region-of-interest analysis. Each patient underwent laboratory and neuropsychological tests. Results Structural MRI revealed no lesions in twelve (HIV-MRN and unspecific mild macrostructural lesions in seven patients (HIV-MRL. Both analyses revealed widespread FA-alterations in all patients. Patients with HIV-MRL had FA-alterations primarily adjacent to the observed lesions and, whilst reduced in extent, patients with HIV-MRN also exhibited FA-alterations in similar regions. Patients with evidence of depression showed FA-increase in the ventral tegmental area, pallidum and nucleus accumbens in both hemispheres, and patients with evidence of HIV-associated neurocognitive disorder showed widespread FA-reduction. Conclusion These results show that patients with HIV-MRN have evidence of FA-alterations in similar regions that are lesioned in HIV-MRL patients, suggesting common neuropathological processes. Furthermore, they suggest a biological rather than a reactive origin of depression in HIV-patients.

  1. White matter alterations in cocaine users are negatively related to the number of additionally (ab)used substances

    NARCIS (Netherlands)

    Kaag, A.M.; van Wingen, G.A.; Caan, M.W.A.; Homberg, J.R.; van den Brink, W.; Reneman, L.

    Diffusion tensor imaging studies have provided evidence for white matter (WM) alterations in cocaine users. While polysubstance use is a widespread phenomenon among cocaine users, its role in WM alterations in cocaine users is currently unknown. This study examined the relation between the number of

  2. Characterization of functional and structural integrity in experimental focal epilepsy: reduced network efficiency coincides with white matter changes.

    Directory of Open Access Journals (Sweden)

    Willem M Otte

    Full Text Available BACKGROUND: Although focal epilepsies are increasingly recognized to affect multiple and remote neural systems, the underlying spatiotemporal pattern and the relationships between recurrent spontaneous seizures, global functional connectivity, and structural integrity remain largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: Here we utilized serial resting-state functional MRI, graph-theoretical analysis of complex brain networks and diffusion tensor imaging to characterize the evolution of global network topology, functional connectivity and structural changes in the interictal brain in relation to focal epilepsy in a rat model. Epileptic networks exhibited a more regular functional topology than controls, indicated by a significant increase in shortest path length and clustering coefficient. Interhemispheric functional connectivity in epileptic brains decreased, while intrahemispheric functional connectivity increased. Widespread reductions of fractional anisotropy were found in white matter regions not restricted to the vicinity of the epileptic focus, including the corpus callosum. CONCLUSIONS/SIGNIFICANCE: Our longitudinal study on the pathogenesis of network dynamics in epileptic brains reveals that, despite the locality of the epileptogenic area, epileptic brains differ in their global network topology, connectivity and structural integrity from healthy brains.

  3. Using CForest to Analyze Diffusion Tensor Imaging Data: A Study of White Matter Integrity in Healthy Aging.

    Science.gov (United States)

    McWhinney, Sean R; Tremblay, Antoine; Chevalier, Thérèse M; Lim, Vanessa K; Newman, Aaron J

    2016-12-01

    Healthy aging has been associated with a global reduction in white matter integrity, which is thought to reflect cognitive decline. The present study aimed to investigate this reduction over a broad range of the life span, using diffusion tensor imaging analyzed with conditional inference random forest modeling (CForest). This approach is sensitive to subtle and potentially nonlinear effects over the age continuum and was used to characterize the progression of decline in greater detail than has been possible in the past. Data were collected from 45 healthy individuals ranging in age from 19 to 67 years. Fractional anisotropy (FA) was estimated using probabilistic tractography for a number of major tracts across the brain. Age coincided with a nonlinear decrease in FA, with onset beginning at ∼30 years of age and the steepest declines occurring later in life. However, several tracts showed a transient increase before this decline. The progression of decline varied by tract, with steeper but later decline occurring in more anterior tracts. Finally, strongly right-handed individuals demonstrated relatively preserved FA until more than a decade following the onset of decline of others. These results demonstrate that using a novel, nonparametric analysis approach, previously reported reductions in FA with healthy aging were confirmed, while at the same time, new insight was provided into the onset and progression of decline, with evidence suggesting increases in integrity continuing into adulthood.

  4. Physical Exercise Keeps the Brain Connected: Biking Increases White Matter Integrity in Patients With Schizophrenia and Healthy Controls.

    Science.gov (United States)

    Svatkova, Alena; Mandl, René C W; Scheewe, Thomas W; Cahn, Wiepke; Kahn, René S; Hulshoff Pol, Hilleke E

    2015-07-01

    It has been shown that learning a new skill leads to structural changes in the brain. However, it is unclear whether it is the acquisition or continuous practicing of the skill that causes this effect and whether brain connectivity of patients with schizophrenia can benefit from such practice. We examined the effect of 6 months exercise on a stationary bicycle on the brain in patients with schizophrenia and healthy controls. Biking is an endemic skill in the Netherlands and thus offers an ideal situation to disentangle the effects of learning vs practice. The 33 participating patients with schizophrenia and 48 healthy individuals were assigned to either one of two conditions, ie, physical exercise or life-as-usual, balanced for diagnosis. Diffusion tensor imaging brain scans were made prior to and after intervention. We demonstrate that irrespective of diagnosis regular physical exercise of an overlearned skill, such as bicycling, significantly increases the integrity, especially of motor functioning related, white matter fiber tracts whereas life-as-usual leads to a decrease in fiber integrity. Our findings imply that exercise of an overlearned physical skill improves brain connectivity in patients and healthy individuals. This has important implications for understanding the effect of fitness programs on the brain in both healthy subjects and patients with schizophrenia. Moreover, the outcome may even apply to the nonphysical realm. © The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  5. Youth Involvement in Politically Motivated Violence: Why Do Social Integration, Perceived Legitimacy, and Perceived Discrimination Matter?

    Directory of Open Access Journals (Sweden)

    Maarten S. De Waele

    2014-09-01

    Full Text Available Several major theories of crime causation have been applied to the study of violence towards persons and towards property (vandalism. Less frequently, these middle-range theoretical frameworks are applied to explain individual differences in political violence. Against a background of growing concern about right-wing political violence among adolescents, the present study examines the role of a number of independent variables derived from different theoretical frameworks in a sample of 2,879 Flemish adolescents. Using blockwise regression models, the independent effects of key independent variables from social control theory, procedural justice theory, general strain theory, social learning theory, and self-control theory are assessed. The results support an integrative approach towards the explanation of political violence. The implications of our findings for future studies on violent extremism are discussed.

  6. White matter atrophy and cognitive dysfunctions in neuromyelitis optica.

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    Frederic Blanc

    Full Text Available Neuromyelitis optica (NMO is an inflammatory disease of central nervous system characterized by optic neuritis and longitudinally extensive acute transverse myelitis. NMO patients have cognitive dysfunctions but other clinical symptoms of brain origin are rare. In the present study, we aimed to investigate cognitive functions and brain volume in NMO. The study population consisted of 28 patients with NMO and 28 healthy control subjects matched for age, sex and educational level. We applied a French translation of the Brief Repeatable Battery (BRB-N to the NMO patients. Using SIENAx for global brain volume (Grey Matter, GM; White Matter, WM; and whole brain and VBM for focal brain volume (GM and WM, NMO patients and controls were compared. Voxel-level correlations between diminished brain concentration and cognitive performance for each tests were performed. Focal and global brain volume of NMO patients with and without cognitive impairment were also compared. Fifteen NMO patients (54% had cognitive impairment with memory, executive function, attention and speed of information processing deficits. Global and focal brain atrophy of WM but not Grey Matter (GM was found in the NMO patients group. The focal WM atrophy included the optic chiasm, pons, cerebellum, the corpus callosum and parts of the frontal, temporal and parietal lobes, including superior longitudinal fascicle. Visual memory, verbal memory, speed of information processing, short-term memory and executive functions were correlated to focal WM volumes. The comparison of patients with, to patients without cognitive impairment showed a clear decrease of global and focal WM, including brainstem, corticospinal tracts, corpus callosum but also superior and inferior longitudinal fascicles. Cognitive impairment in NMO patients is correlated to the decreased of global and focal WM volume of the brain. Further studies are needed to better understand the precise origin of cognitive impairment in

  7. Relationship between white matter integrity and serum cortisol levels in drug-naive patients with major depressive disorder: diffusion tensor imaging study using tract-based spatial statistics.

    Science.gov (United States)

    Liu, Xiaodan; Watanabe, Keita; Kakeda, Shingo; Yoshimura, Reiji; Abe, Osamu; Ide, Satoru; Hayashi, Kenji; Katsuki, Asuka; Umene-Nakano, Wakako; Watanabe, Rieko; Ueda, Issei; Nakamura, Jun; Korogi, Yukunori

    2016-06-01

    Higher daytime cortisol levels because of a hyperactive hypothalamic-pituitary-adrenal axis have been reported in patients with major depressive disorder (MDD). The elevated glucocorticoids inhibit the proliferation of the oligodendrocytes that are responsible for myelinating the axons of white matter fibre tracts. To evaluate the relationship between white matter integrity and serum cortisol levels during a first depressive episode in drug-naive patients with MDD (MDD group) using a tract-based spatial statistics (TBSS) method. The MDD group (n = 29) and a healthy control group (n = 47) underwent diffusion tensor imaging (DTI) scans and an analysis was conducted using TBSS. Morning blood samples were obtained from both groups for cortisol measurement. Compared with the controls, the MDD group had significantly reduced fractional anisotropy values (Plevels in the MDD group (Plevels in the MDD group may injure the white matter integrity in the frontal-subcortical and frontal-limbic circuits. © The Royal College of Psychiatrists 2016.

  8. White matter and schizophrenia: A meta-analysis of voxel-based morphometry and diffusion tensor imaging studies.

    Science.gov (United States)

    Vitolo, Enrico; Tatu, Mona Karina; Pignolo, Claudia; Cauda, Franco; Costa, Tommaso; Ando', Agata; Zennaro, Alessandro

    2017-12-30

    Voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) are the most implemented methodologies to detect alterations of both gray and white matter (WM). However, the role of WM in mental disorders is still not well defined. We aimed at clarifying the role of WM disruption in schizophrenia and at identifying the most frequently involved brain networks. A systematic literature search was conducted to identify VBM and DTI studies focusing on WM alterations in patients with schizophrenia compared to control subjects. We selected studies reporting the coordinates of WM reductions and we performed the anatomical likelihood estimation (ALE). Moreover, we labeled the WM bundles with an anatomical atlas and compared VBM and DTI ALE-scores of each significant WM tract. A total of 59 studies were eligible for the meta-analysis. WM alterations were reported in 31 and 34 foci with VBM and DTI methods, respectively. The most occurred WM bundles in both VBM and DTI studies and largely involved in schizophrenia were long projection fibers, callosal and commissural fibers, part of motor descending fibers, and fronto-temporal-limbic pathways. The meta-analysis showed a widespread WM disruption in schizophrenia involving specific cerebral circuits instead of well-defined regions. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Integration of optical and chemical parameters to improve the particulate matter characterization

    Science.gov (United States)

    Perrone, M. R.; Romano, S.; Genga, A.; Paladini, F.

    2018-06-01

    Integrating nephelometer measurements have been combined with co-located in space and time PM10 and PM1 mass concentration measurements to highlight the benefits of integrating aerosol optical properties with the chemical speciation of PM1 and PM10 samples. Inorganic ions (SO42-, NO3-, NH4+, Cl-, Na+, K+, Mg2+, and Ca2+), metals (Fe, Al, Zn, Ti, Cu, V, Mn, and Cr), and the elemental and organic carbon (EC and OC, respectively) have been monitored to characterize the chemical composition of PM1 and PM10 samples, respectively. The scattering coefficient (σp) at 450 nm, the scattering Ångström coefficient (Å) calculated at the 450-635 nm wavelength pair, and the scattering Ångström coefficient difference (ΔÅ) retrieved from nephelometer measurements have been used to characterize the optical properties of the particles at the surface. The frequency distribution of the Å daily means during the one-year monitoring campaign, performed at a southeastern Italian site, has allowed identifying three main Å variability ranges: Å ≤ 0.8, 0.8 1.2. We found that σp and ΔÅ mean values and the mean chemical composition of the PM1 and PM10 samples varied with the Å variability range. σp and ΔÅ reached the highest (149 Mm-1) and the smallest (0.16) mean value, respectively, on the days characterized by Å > 1.2. EC, SO42-, and NH4+ mean mass percentages also reached the highest mean value on the Å > 1.2 days, representing on average 8.4, 9.8, and 4.2%, respectively, of the sampled PM10 mass and 12.4, 10.6, and 7.7%, respectively, of the PM1 mass. Conversely, σp and ΔÅ mean values were equal to 85 Mm-1 and 0.55, respectively, on the days characterized by Å ≤ 0.8 and the EC, SO42-, and NH4+ mean mass percentages reached smaller values on the Å ≤ 0.8 days, representing 4.5, 6.0, and 1.9% of the PM10 mass and 9.4, 7.3, and 5.8% of the PM1 mass, respectively. Primary and secondary OC (POC and SOC, respectively) contributions also varied with the

  10. Marriage and Partnership Integrity After Aneurysmal Subarachnoid Hemorrhage: Small Alterations in Neurologic Status Matter Most.

    Science.gov (United States)

    Schöni, Daniel; Lauber, Lara; Fung, Christian; Goldberg, Johannes; Müri, René; Raabe, Andreas; Nyffeler, Thomas; Beck, Jürgen

    2018-05-01

    Common sequelae of subarachnoid hemorrhage (SAH) include somatic and/or cognitive impairment. This can cause emotional stress, social tensions, and difficulties in relationships. To test our hypothesis that more severe somatic and cognitive impairments increased the likelihood of disruption of a relationship after SAH, we assessed the integrity of marriage or partnership status in a well-evaluated subset of SAH patients. Our sample comprised 50 SAH patients who were discharged to a neurologic, in-house rehabilitation center between 2005 and 2010. Deficits on admission to the rehabilitation center were divided into 18 categories and grouped into minor and major somatic deficits, as well as cognitive deficits. Clinical outcome scores, marital/partnership status, and duration of partnership before ictus were recorded. A follow-up questionnaire after 4.3 (2012) and 8.8 (2017) years was used to assess changes in marital/partnership status. Possible predictor parameters were estimated and included in a stepdown regression analysis. In 2012, after a mean follow-up of 4.3 years, 8 of the 50 SAH patients were divorced or separated, whereas after 8.8 years only 1 additional relationship had ended. In our regression model analysis, a "short duration of relationship" before SAH and the presence of a "few minor somatic deficits" were associated with a higher likelihood of divorce or separation in the near future and remained unchanged at long-term follow-up. Contrary to our hypothesis, neither the presence of severe somatic or cognitive deficits nor clinical evaluation scores reliably predicted divorce or separation after SAH. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Association of schizophrenia onset age and white matter integrity with treatment effect of D-cycloserine: a randomized placebo-controlled double-blind crossover study.

    Science.gov (United States)

    Takiguchi, Kazuo; Uezato, Akihito; Itasaka, Michio; Atsuta, Hidenori; Narushima, Kenji; Yamamoto, Naoki; Kurumaji, Akeo; Tomita, Makoto; Oshima, Kazunari; Shoda, Kosaku; Tamaru, Mai; Nakataki, Masahito; Okazaki, Mitsutoshi; Ishiwata, Sayuri; Ishiwata, Yasuyoshi; Yasuhara, Masato; Arima, Kunimasa; Ohmori, Tetsuro; Nishikawa, Toru

    2017-07-12

    It has been reported that drugs which promote the N-Methyl-D-aspartate-type glutamate receptor function by stimulating the glycine modulatory site in the receptor improve negative symptoms and cognitive dysfunction in schizophrenia patients being treated with antipsychotic drugs. We performed a placebo-controlled double-blind crossover study involving 41 schizophrenia patients in which D-cycloserine 50 mg/day was added-on, and the influence of the onset age and association with white matter integrity on MR diffusion tensor imaging were investigated for the first time. The patients were evaluated using the Positive and Negative Syndrome Scale (PANSS), Scale for the Assessment of Negative Symptoms (SANS), Brief Assessment of Cognition in Schizophrenia (BACS), and other scales. D-cycloserine did not improve positive or negative symptoms or cognitive dysfunction in schizophrenia. The investigation in consideration of the onset age suggests that D-cycloserine may aggravate negative symptoms of early-onset schizophrenia. The better treatment effect of D-cycloserine on BACS was observed when the white matter integrity of the sagittal stratum/ cingulum/fornix stria terminalis/genu of corpus callosum/external capsule was higher, and the better treatment effect on PANSS general psychopathology (PANSS-G) was observed when the white matter integrity of the splenium of corpus callosum was higher. In contrast, the better treatment effect of D-cycloserine on PANSS-G and SANS-IV were observed when the white matter integrity of the posterior thalamic radiation (left) was lower. It was suggested that response to D-cycloserine is influenced by the onset age and white matter integrity. UMIN Clinical Trials Registry (number UMIN000000468 ). Registered 18 August 2006.

  12. Selection Ideal Coal Suppliers of Thermal Power Plants Using the Matter-Element Extension Model with Integrated Empowerment Method for Sustainability

    Directory of Open Access Journals (Sweden)

    Zhongfu Tan

    2014-01-01

    Full Text Available In order to reduce thermal power generation cost and improve its market competitiveness, considering fuel quality, cost, creditworthiness, and sustainable development capacity factors, this paper established the evaluation system for coal supplier selection of thermal power and put forward the coal supplier selection strategies for thermal power based on integrated empowering and ideal matter-element extension models. On the one hand, the integrated empowering model can overcome the limitations of subjective and objective methods to determine weights, better balance subjective, and objective information. On the other hand, since the evaluation results of the traditional element extension model may fall into the same class and only get part of the order results, in order to overcome this shortcoming, the idealistic matter-element extension model is constructed. It selects the ideal positive and negative matter-elements classical field and uses the closeness degree to replace traditional maximum degree of membership criterion and calculates the positive or negative distance between the matter-element to be evaluated and the ideal matter-element; then it can get the full order results of the evaluation schemes. Simulated and compared with the TOPSIS method, Romania selection method, and PROMETHEE method, numerical example results show that the method put forward by this paper is effective and reliable.

  13. Apportioning sources of organic matter in streambed sediments: An integrated molecular and compound-specific stable isotope approach

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Richard J., E-mail: Richard.J.Cooper@uea.ac.uk [School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ (United Kingdom); Pedentchouk, Nikolai; Hiscock, Kevin M.; Disdle, Paul [School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ (United Kingdom); Krueger, Tobias [IRI THESys, Humboldt University, 10099 Berlin (Germany); Rawlins, Barry G. [British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom)

    2015-07-01

    apportionment of organic matter sources. Median organic matter contributions ranged from 22% to 52% for trees, 29% to 50% for herbaceous perennials, 17% to 34% for C{sub 3} graminoids and 3% to 7% for C{sub 4} graminoids. The results presented here clearly demonstrate the effectiveness of an integrated molecular and stable isotope analysis for quantitatively apportioning, with uncertainty, plant-specific organic matter contributions to streambed sediments via a Bayesian mixing model approach. - Highlights: • Organic contributions from trees, herbs and C{sub 3}/C{sub 4} graminoids are apportioned. • δ{sup 2}H provides strong discrimination between plant functional types. • δ{sup 13}C provides strong contrasts between C{sub 3} and C{sub 4} plants. • δ{sup 2}H and δ{sup 13}C values could not differentiate aquatic and terrestrial species. • n-Alkane ratios compliment isotopic discrimination.

  14. Early postnatal exposure to intermittent hypoxia in rodents is proinflammatory, impairs white matter integrity, and alters brain metabolism.

    Science.gov (United States)

    Darnall, Robert A; Chen, Xi; Nemani, Krishnamurthy V; Sirieix, Chrystelle M; Gimi, Barjor; Knoblach, Susan; McEntire, Betty L; Hunt, Carl E

    2017-07-01

    BackgroundPreterm infants are frequently exposed to intermittent hypoxia (IH) associated with apnea and periodic breathing that may result in inflammation and brain injury that later manifests as cognitive and executive function deficits. We used a rodent model to determine whether early postnatal exposure to IH would result in inflammation and brain injury.MethodsRat pups were exposed to IH from P2 to P12. Control animals were exposed to room air. Cytokines were analyzed in plasma and brain tissue at P13 and P18. At P20-P22, diffusion tensor imaging (DTI) and magnetic resonance spectroscopy (MRS) were performed.ResultsPups exposed to IH had increased plasma Gro/CXCL1 and cerebellar IFN-γ and IL-1β at P13, and brainstem enolase at P18. DTI showed a decrease in FA and AD in the corpus callosum (CC) and cingulate gyrus, and an increase in RD in the CC. MRS revealed decreases in NAA/Cho, Cr, Tau/Cr, and Gly/Cr; increases in TCho and GPC in the brainstem; and decreases in NAA/Cho in the hippocampus.ConclusionsWe conclude that early postnatal exposure to IH, similar in magnitude to that experienced in human preterm infants, is associated with evidence for proinflammatory changes, decreases in white matter integrity, and metabolic changes consistent with hypoxia.

  15. Genetic effect of MTHFR C677T polymorphism on the structural covariance network and white-matter integrity in Alzheimer's disease.

    Science.gov (United States)

    Chang, Yu-Tzu; Hsu, Shih-Wei; Tsai, Shih-Jen; Chang, Ya-Ting; Huang, Chi-Wei; Liu, Mu-En; Chen, Nai-Ching; Chang, Wen-Neng; Hsu, Jung-Lung; Lee, Chen-Chang; Chang, Chiung-Chih

    2017-06-01

    The 677 C to T transition in the MTHFR gene is a genetic determinant for hyperhomocysteinemia. We investigated whether this polymorphism modulates gray matter (GM) structural covariance networks independently of white-matter integrity in patients with Alzheimer's disease (AD). GM structural covariance networks were constructed by 3D T1-magnetic resonance imaging and seed-based analysis. The patients were divided into two genotype groups: C homozygotes (n = 73) and T carriers (n = 62). Using diffusion tensor imaging and white-matter parcellation, 11 fiber bundle integrities were compared between the two genotype groups. Cognitive test scores were the major outcome factors. The T carriers had higher homocysteine levels, lower posterior cingulate cortex GM volume, and more clusters in the dorsal medial lobe subsystem showing stronger covariance strength. Both posterior cingulate cortex seed and interconnected peak cluster volumes predicted cognitive test scores, especially in the T carriers. There were no between-group differences in fiber tract diffusion parameters. The MTHFR 677T polymorphism modulates posterior cingulate cortex-anchored structural covariance strength independently of white matter integrities. Hum Brain Mapp 38:3039-3051, 2017. © 2017 The Authors Human Brain Mapping Published Wiley by Periodicals, Inc. © 2017 The Authors Human Brain Mapping Published Wiley by Periodicals, Inc.

  16. Increased gray matter volume of left pars opercularis in male orchestral musicians correlate positively with years of musical performance.

    Science.gov (United States)

    Abdul-Kareem, Ihssan A; Stancak, Andrej; Parkes, Laura M; Sluming, Vanessa

    2011-01-01

    To compare manual volumetry of gray matter (GM) / white matter (WM) of Broca's area subparts: pars opercularis (POP) and pars triangularis (PTR) in both hemispheres between musicians and nonmusician, as it has been shown that these regions are crucial for musical abilities. A previous voxel-based morphometric (VBM) study conducted in our laboratory reported increased GM density in Broca's area of left hemisphere in male orchestral musicians. Functional segregation of POP/PTR justified separate volumetric analysis of these parts. We used the same cohort for the VBM study. Manual morphometry (stereology) was used to compare volumes between 26/26 right-handed orchestral musicians/nonmusicians. As expected, musicians showed significantly increased GM volume in the Broca's area, specifically in the left POP. No significant results were detected in right POP, left/right PTR GM volumes, and WM volumes for all regions. Results were positively correlated with years of musical performance (r = 0.7, P = 0.0001). This result corroborates the VBM study and is in line with the hypothesis of critical involvement of POP in hearing-action integration being an integral component of frontoparietotemporal mirror neuron network. We hypothesize that increased size of musicians' left POP represent use-dependent structural adaptation in response to intensive audiomotor skill acquisition. Copyright © 2010 Wiley-Liss, Inc.

  17. White matter sexual dimorphism of the adult human brain

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    Bourisly Ali K.

    2017-05-01

    Full Text Available Sex-biased psychophysiology, behavior, brain function, and conditions are extensive, yet underlying structural brain mechanisms remain unclear. There is contradicting evidence regarding sexual dimorphism when it comes to brain structure, and there is still no consensus on whether or not there exists such a dimorphism for brain white matter. Therefore, we conducted a voxel-based morphometry (VBM analysis along with global volume analysis for white matter across sex. We analyzed 384 T1-weighted MRI brain images (192 male, 192 female to investigate any differences in white matter (WM between males and females. In the VBM analysis, we found males to have larger WM, compared to females, in occipital, temporal, insular, parietal, and frontal brain regions. In contrast, females showed only one WM region to be significantly larger than males: the right postcentral gyrus in the parietal lobe region. Although, on average, males showed larger global WM volume, we did not find any significant difference in global WM volume between males and females.

  18. A template-based procedure for determining white matter integrity in the internal capsule early after stroke

    Directory of Open Access Journals (Sweden)

    Matthew A. Petoe

    2014-01-01

    Full Text Available The integrity of descending white matter pathways, measured by fractional anisotropy from DW-MRI, is a key prognostic indicator of motor recovery after stroke. Barriers to translation of fractional anisotropy measures into routine clinical practice include the time required for manually delineating volumes of interest (VOIs, and inter-examiner variability in this process. This study investigated whether registering and then editing template volumes of interest ‘as required’ would improve inter-examiner reliability compared with manual delineation, without compromising validity. MRI was performed with 30 sub-acute stroke patients with motor deficits (mean NIHSS = 11, range 0–17. Four independent examiners manually delineated VOIs for the posterior limbs of the internal capsules on T1 images, or edited template VOIs that had been registered to the T1 images if they encroached on ventricles or basal ganglia. Fractional anisotropy within each VOI and interhemispheric asymmetry were then calculated. We found that 13/30 registered template VOIs required editing. Edited template VOIs were more spatially similar between examiners than the manually delineated VOIs (p = 0.005. Both methods produced similar asymmetry values that correlated with clinical scores with near perfect levels of agreement between examiners. Contralesional fractional anisotropy correlated with age when edited template VOIs were used but not when VOIs were manually delineated. Editing template VOIs as required is reliable, increases the validity of fractional anisotropy measurements in the posterior limb of the internal capsule, and is less time-consuming compared to manual delineation. This approach could support the use of FA asymmetry measures in routine clinical practice.

  19. Altered brain network integrity after childhood maltreatment: A structural connectomic DTI-study

    NARCIS (Netherlands)

    Puetz, V.B.; Parker, D.; Kohn, N.; Dahmen, B.; Verma, R.; Konrad, K.

    2017-01-01

    Childhood maltreatment is associated with alterations in neural architecture that potentially put these children at increased risk for psychopathology. Alterations in white matter (WM) tracts have been reported, however no study to date has investigated WM connectivity in brain networks in

  20. Quantifying Cerebellum Grey Matter and White Matter Perfusion Using Pulsed Arterial Spin Labeling

    Directory of Open Access Journals (Sweden)

    Xiufeng Li

    2014-01-01

    Full Text Available To facilitate quantification of cerebellum cerebral blood flow (CBF, studies were performed to systematically optimize arterial spin labeling (ASL parameters for measuring cerebellum perfusion, segment cerebellum to obtain separate CBF values for grey matter (GM and white matter (WM, and compare FAIR ASST to PICORE. Cerebellum GM and WM CBF were measured with optimized ASL parameters using FAIR ASST and PICORE in five subjects. Influence of volume averaging in voxels on cerebellar grey and white matter boundaries was minimized by high-probability threshold masks. Cerebellar CBF values determined by FAIR ASST were 43.8 ± 5.1 mL/100 g/min for GM and 27.6 ± 4.5 mL/100 g/min for WM. Quantitative perfusion studies indicated that CBF in cerebellum GM is 1.6 times greater than that in cerebellum WM. Compared to PICORE, FAIR ASST produced similar CBF estimations but less subtraction error and lower temporal, spatial, and intersubject variability. These are important advantages for detecting group and/or condition differences in CBF values.

  1. Quantifying cerebellum grey matter and white matter perfusion using pulsed arterial spin labeling.

    Science.gov (United States)

    Li, Xiufeng; Sarkar, Subhendra N; Purdy, David E; Briggs, Richard W

    2014-01-01

    To facilitate quantification of cerebellum cerebral blood flow (CBF), studies were performed to systematically optimize arterial spin labeling (ASL) parameters for measuring cerebellum perfusion, segment cerebellum to obtain separate CBF values for grey matter (GM) and white matter (WM), and compare FAIR ASST to PICORE. Cerebellum GM and WM CBF were measured with optimized ASL parameters using FAIR ASST and PICORE in five subjects. Influence of volume averaging in voxels on cerebellar grey and white matter boundaries was minimized by high-probability threshold masks. Cerebellar CBF values determined by FAIR ASST were 43.8 ± 5.1 mL/100 g/min for GM and 27.6 ± 4.5 mL/100 g/min for WM. Quantitative perfusion studies indicated that CBF in cerebellum GM is 1.6 times greater than that in cerebellum WM. Compared to PICORE, FAIR ASST produced similar CBF estimations but less subtraction error and lower temporal, spatial, and intersubject variability. These are important advantages for detecting group and/or condition differences in CBF values.

  2. Quantifying Cerebellum Grey Matter and White Matter Perfusion Using Pulsed Arterial Spin Labeling

    Science.gov (United States)

    Li, Xiufeng; Sarkar, Subhendra N.; Purdy, David E.; Briggs, Richard W.

    2014-01-01

    To facilitate quantification of cerebellum cerebral blood flow (CBF), studies were performed to systematically optimize arterial spin labeling (ASL) parameters for measuring cerebellum perfusion, segment cerebellum to obtain separate CBF values for grey matter (GM) and white matter (WM), and compare FAIR ASST to PICORE. Cerebellum GM and WM CBF were measured with optimized ASL parameters using FAIR ASST and PICORE in five subjects. Influence of volume averaging in voxels on cerebellar grey and white matter boundaries was minimized by high-probability threshold masks. Cerebellar CBF values determined by FAIR ASST were 43.8 ± 5.1 mL/100 g/min for GM and 27.6 ± 4.5 mL/100 g/min for WM. Quantitative perfusion studies indicated that CBF in cerebellum GM is 1.6 times greater than that in cerebellum WM. Compared to PICORE, FAIR ASST produced similar CBF estimations but less subtraction error and lower temporal, spatial, and intersubject variability. These are important advantages for detecting group and/or condition differences in CBF values. PMID:24949416

  3. Identifying the white matter impairments among ART-naive HIV patients: a multivariate pattern analysis of DTI data

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Zhenchao [Shandong University, School of Mechanical, Electrical and Information Engineering, Weihai, Shandong Province (China); Institute of Automation, CAS Key Laboratory of Molecular Imaging, Beijing (China); Liu, Zhenyu; Yang, Xin; Wang, Shuo; Yu, Dongdong [Institute of Automation, CAS Key Laboratory of Molecular Imaging, Beijing (China); Li, Ruili; Li, Hongjun [Beijing YouAn Hospital, Capital Medical University, Department of Radiology, Beijing (China); Cui, Xingwei [Zhengzhou University, Cooperative Innovation Center of Internet Healthcare, Zhengzhou (China); Dong, Enqing [Shandong University, School of Mechanical, Electrical and Information Engineering, Weihai, Shandong Province (China); Tian, Jie [Institute of Automation, CAS Key Laboratory of Molecular Imaging, Beijing (China); University of Chinese Academy of Sciences, Beijing (China)

    2017-10-15

    To identify the white matter (WM) impairments of the antiretroviral therapy (ART)-naive HIV patients by conducting a multivariate pattern analysis (MVPA) of Diffusion Tensor Imaging (DTI) data We enrolled 33 ART-naive HIV patients and 32 Normal controls in the current study. Firstly, the DTI metrics in whole brain WM tracts were extracted for each subject and feed into the Least Absolute Shrinkage and Selection Operators procedure (LASSO)-Logistic regression model to identify the impaired WM tracts. Then, Support Vector Machines (SVM) model was constructed based on the DTI metrics in the impaired WM tracts to make HIV-control group classification. Pearson correlations between the WM impairments and HIV clinical statics were also investigated. Extensive HIV-related impairments were observed in the WM tracts associated with motor function, the corpus callosum (CC) and the frontal WM. With leave-one-out cross validation, accuracy of 83.08% (P=0.002) and the area under the Receiver Operating Characteristic curve of 0.9110 were obtained in the SVM classification model. The impairments of the CC were significantly correlated with the HIV clinic statics. The MVPA was sensitive to detect the HIV-related WM changes. Our findings indicated that the MVPA had considerable potential in exploring the HIV-related WM impairments. (orig.)

  4. Identifying the white matter impairments among ART-naive HIV patients: a multivariate pattern analysis of DTI data

    International Nuclear Information System (INIS)

    Tang, Zhenchao; Liu, Zhenyu; Yang, Xin; Wang, Shuo; Yu, Dongdong; Li, Ruili; Li, Hongjun; Cui, Xingwei; Dong, Enqing; Tian, Jie

    2017-01-01

    To identify the white matter (WM) impairments of the antiretroviral therapy (ART)-naive HIV patients by conducting a multivariate pattern analysis (MVPA) of Diffusion Tensor Imaging (DTI) data We enrolled 33 ART-naive HIV patients and 32 Normal controls in the current study. Firstly, the DTI metrics in whole brain WM tracts were extracted for each subject and feed into the Least Absolute Shrinkage and Selection Operators procedure (LASSO)-Logistic regression model to identify the impaired WM tracts. Then, Support Vector Machines (SVM) model was constructed based on the DTI metrics in the impaired WM tracts to make HIV-control group classification. Pearson correlations between the WM impairments and HIV clinical statics were also investigated. Extensive HIV-related impairments were observed in the WM tracts associated with motor function, the corpus callosum (CC) and the frontal WM. With leave-one-out cross validation, accuracy of 83.08% (P=0.002) and the area under the Receiver Operating Characteristic curve of 0.9110 were obtained in the SVM classification model. The impairments of the CC were significantly correlated with the HIV clinic statics. The MVPA was sensitive to detect the HIV-related WM changes. Our findings indicated that the MVPA had considerable potential in exploring the HIV-related WM impairments. (orig.)

  5. Isotropic non-white matter partial volume effects in constrained spherical deconvolution

    Directory of Open Access Journals (Sweden)

    Timo eRoine

    2014-03-01

    Full Text Available Diffusion-weighted (DW magnetic resonance imaging (MRI is a noninvasive imaging method, which can be used to investigate neural tracts in the white matter (WM of the brain. Significant partial volume effects (PVE are present in the DW signal due to relatively large voxel sizes. These PVEs can be caused by both non-WM tissue, such as gray matter (GM and cerebrospinal fluid (CSF, and by multiple nonparallel WM fiber populations. High angular resolution diffusion imaging (HARDI methods have been developed to correctly characterize complex WM fiber configurations, but to date, many of the HARDI methods do not account for non-WM PVEs. In this work, we investigated the isotropic PVEs caused by non-WM tissue in WM voxels on fiber orientations extracted with constrained spherical deconvolution (CSD. Experiments were performed on simulated and real DW-MRI data. In particular, simulations were performed to demonstrate the effects of varying the diffusion weightings, signal-to-noise ratios (SNR, fiber configurations, and tissue fractions.Our results show that the presence of non-WM tissue signal causes a decrease in the precision of the detected fiber orientations and an increase in the detection of false peaks in CSD. We estimated 35-50 % of WM voxels to be affected by non-WM PVEs. For HARDI sequences, which typically have a relatively high degree of diffusion weighting, these adverse effects are most pronounced in voxels with GM PVEs. The non-WM PVEs become severe with 50 % GM volume for maximum spherical harmonics orders of 8 and below, and already with 25 % GM volume for higher orders. In addition, a low diffusion weighting or SNR increases the effects. The non-WM PVEs may cause problems in connectomics, where reliable fiber tracking at the WM-GM interface is especially important. We suggest acquiring data with high diffusion-weighting 2500-3000 s/mm2, reasonable SNR (~30 and using lower SH orders in GM contaminated regions to minimize the non-WM PVEs

  6. Isotropic non-white matter partial volume effects in constrained spherical deconvolution.

    Science.gov (United States)

    Roine, Timo; Jeurissen, Ben; Perrone, Daniele; Aelterman, Jan; Leemans, Alexander; Philips, Wilfried; Sijbers, Jan

    2014-01-01

    Diffusion-weighted (DW) magnetic resonance imaging (MRI) is a non-invasive imaging method, which can be used to investigate neural tracts in the white matter (WM) of the brain. Significant partial volume effects (PVEs) are present in the DW signal due to relatively large voxel sizes. These PVEs can be caused by both non-WM tissue, such as gray matter (GM) and cerebrospinal fluid (CSF), and by multiple non-parallel WM fiber populations. High angular resolution diffusion imaging (HARDI) methods have been developed to correctly characterize complex WM fiber configurations, but to date, many of the HARDI methods do not account for non-WM PVEs. In this work, we investigated the isotropic PVEs caused by non-WM tissue in WM voxels on fiber orientations extracted with constrained spherical deconvolution (CSD). Experiments were performed on simulated and real DW-MRI data. In particular, simulations were performed to demonstrate the effects of varying the diffusion weightings, signal-to-noise ratios (SNRs), fiber configurations, and tissue fractions. Our results show that the presence of non-WM tissue signal causes a decrease in the precision of the detected fiber orientations and an increase in the detection of false peaks in CSD. We estimated 35-50% of WM voxels to be affected by non-WM PVEs. For HARDI sequences, which typically have a relatively high degree of diffusion weighting, these adverse effects are most pronounced in voxels with GM PVEs. The non-WM PVEs become severe with 50% GM volume for maximum spherical harmonics orders of 8 and below, and already with 25% GM volume for higher orders. In addition, a low diffusion weighting or SNR increases the effects. The non-WM PVEs may cause problems in connectomics, where reliable fiber tracking at the WM-GM interface is especially important. We suggest acquiring data with high diffusion-weighting 2500-3000 s/mm(2), reasonable SNR (~30) and using lower SH orders in GM contaminated regions to minimize the non-WM PVEs in CSD.

  7. Moderate Physical Activity Mediates the Association between White Matter Lesion Volume and Memory Recall in Breast Cancer Survivors.

    Directory of Open Access Journals (Sweden)

    Gillian E Cooke

    Full Text Available Increased survival rates among breast cancer patients have drawn significant attention to consequences of both the presence of cancer, and the subsequent treatment-related impact on the brain. The incidence of breast cancer and the effects of treatment often result in alterations in the microstructure of white matter and impaired cognitive functioning. However, physical activity is proving to be a successful modifiable lifestyle factor in many studies that could prove beneficial to breast cancer survivors. This study investigates the link between white matter lesion volume, moderate physical activity, and cognition in breast cancer survivors following treatment compared to non-cancer age-matched controls. Results revealed that brain structure significantly predicted cognitive function via mediation of physical activity in breast cancer survivors. Overall, the study provided preliminary evidence suggesting moderate physical activity may help reduce the treatment related risks associated with breast cancer, including changes to WM integrity and cognitive impairment.

  8. Action Video Game Experience Related to Altered Large-Scale White Matter Networks.

    Science.gov (United States)

    Gong, Diankun; Ma, Weiyi; Gong, Jinnan; He, Hui; Dong, Li; Zhang, Dan; Li, Jianfu; Luo, Cheng; Yao, Dezhong

    2017-01-01

    With action video games (AVGs) becoming increasingly popular worldwide, the cognitive benefits of AVG experience have attracted continuous research attention over the past two decades. Research has repeatedly shown that AVG experience can causally enhance cognitive ability and is related to neural plasticity in gray matter and functional networks in the brain. However, the relation between AVG experience and the plasticity of white matter (WM) network still remains unclear. WM network modulates the distribution of action potentials, coordinating the communication between brain regions and acting as the framework of neural networks. And various types of cognitive deficits are usually accompanied by impairments of WM networks. Thus, understanding this relation is essential in assessing the influence of AVG experience on neural plasticity and using AVG experience as an interventional tool for impairments of WM networks. Using graph theory, this study analyzed WM networks in AVG experts and amateurs. Results showed that AVG experience is related to altered WM networks in prefrontal networks, limbic system, and sensorimotor networks, which are related to cognitive control and sensorimotor functions. These results shed new light on the influence of AVG experience on the plasticity of WM networks and suggested the clinical applicability of AVG experience.

  9. Action Video Game Experience Related to Altered Large-Scale White Matter Networks

    Directory of Open Access Journals (Sweden)

    Diankun Gong

    2017-01-01

    Full Text Available With action video games (AVGs becoming increasingly popular worldwide, the cognitive benefits of AVG experience have attracted continuous research attention over the past two decades. Research has repeatedly shown that AVG experience can causally enhance cognitive ability and is related to neural plasticity in gray matter and functional networks in the brain. However, the relation between AVG experience and the plasticity of white matter (WM network still remains unclear. WM network modulates the distribution of action potentials, coordinating the communication between brain regions and acting as the framework of neural networks. And various types of cognitive deficits are usually accompanied by impairments of WM networks. Thus, understanding this relation is essential in assessing the influence of AVG experience on neural plasticity and using AVG experience as an interventional tool for impairments of WM networks. Using graph theory, this study analyzed WM networks in AVG experts and amateurs. Results showed that AVG experience is related to altered WM networks in prefrontal networks, limbic system, and sensorimotor networks, which are related to cognitive control and sensorimotor functions. These results shed new light on the influence of AVG experience on the plasticity of WM networks and suggested the clinical applicability of AVG experience.

  10. An integrated system for the determination of the local, regional and long-transport contributions to Particulate Matter concentrations

    Science.gov (United States)

    Amodio, M.; Andriani, E.; Daresta, B. E.; de Gennaro, G.; di Gilio, A.; Ielpo, P.,; Placentino, C. M.; Trizio, L.; Tutino, M.

    2010-05-01

    Several epidemiological studies have shown the negative effects of air pollution on human health, which range from respiratory and cardiovascular disease to neurotoxic effects, and cancer. Most recent investigations have been focused on health toxicological features of Particulate Matter (PM) and its interactions with other pollutants: it was found that fine particles (PM2.5) could be an effective media to transport these pollutants deeply into the lung and to cause many kind of reactions which include oxidative stress, local pulmonary and systemic inflammatory responses (Künzli and Perez, 2009). Based on these implications on public health, many countries have developed plans to suggest effective control strategies which involve the identification of Particulate Matter sources, the quantitative estimation of the emission rates of the pollutants, the understanding of PM transport, mixing and transformation processes and the identification of main factors influencing PM concentrations. In this field, receptor models can be useful tools to estimate sources contributions to PM collected in an area under investigations. Different approaches to receptor model analysis can be distinguished on basis of whether chemical characteristics of emission sources are required to be known before the source apportionment. The multivariate approach could be preferred when a lack of information concerning sources profiles occurred (Hopke, 2003). In this work, the results obtained by applying an integrated approach in the monitoring of PM using several typologies of instrumentations will be shown. A prototype for the determination of the contributions of a single source (‘fugitive emission') on the fine PM concentrations has been developed: it consists of a Swam dual-channel sampler, an OPC Monitor, a sonic anemometer and a PBL Mixing monitor. The investigated site chosen for the application of prototype will be the iron and steel pole of Taranto (Apulia Region, South of Italy

  11. Physical and Human Controls on the Carbon Composition of Organic Matter in Tropical Rivers: An Integrated Analysis of Landscape Properties and River Isotopic Composition

    Energy Technology Data Exchange (ETDEWEB)

    Ballester, M. V.R.; Victoria, R. L.; Krusche, A. V. [Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo, Piracicaba (Brazil); Bernardes, M. [Universidade Federal Fluminense, Rio de Janeiro (Brazil); Neill, C.; Deegan, L. [Marine Biological Laboratory, Woods Hole, MA (United States); Richey, J. E. [University of Washington, Seatle, WA (United States)

    2013-05-15

    We applied an integrated analysis of landscape properties including soil properties, land cover and riverine isotopic composition. To evaluate physical and human controls on the carbon composition of organic matter in tropical rivers, we applied an integrated analysis of landscape properties including soil properties, land cover and riverine isotopic composition. Our main objective was to establish the relationship between basin attributes and forms, fluxes and composition of dissolved and particulate organic matter in river channels. A physical template was developed as a GIS-based comprehensive tool to support the understanding of the biogeochemistry of the surface waters of two tropical rivers: the Ji-Parana (Western Amazonia) and the Piracicaba (southeastern of Brazil). For each river we divided the basin into drainage units, organized according to river network morphology and degree of land use impact. Each sector corresponded to a sampling point where river isotopic composition was analysed. River sites and basin characteristics were calculated using datasets compiled as layers in ArcGis Geographical Information System and ERDAS-IMAGINE (Image Processing) software. Each delineated drainage area was individually characterized in terms of topography, soils, river network and land use. Carbon stable isotopic composition of dissolved organic matter (DOM) and particulate organic matter (POM) was determined at several sites along the main tributaries and small streams. The effects of land use on fluvial carbon composition were quantified by a linear regression analysis, relating basin cover and river isotopic composition. The results showed that relatively recent land cover changes have already had an impact on the composition of the riverine DOM and POM, indicating that, as in natural ecosystems, vegetation plays a key role in the composition of riverine organic matter in agricultural ecosystems. (author)

  12. The Microbial Efficiency-Matrix Stabilization (MEMS) framework integrates plant litter decomposition with soil organic matter stabilization: do labile plant inputs form stable soil organic matter?

    Science.gov (United States)

    Cotrufo, M Francesca; Wallenstein, Matthew D; Boot, Claudia M; Denef, Karolien; Paul, Eldor

    2013-04-01

    The decomposition and transformation of above- and below-ground plant detritus (litter) is the main process by which soil organic matter (SOM) is formed. Yet, research on litter decay and SOM formation has been largely uncoupled, failing to provide an effective nexus between these two fundamental processes for carbon (C) and nitrogen (N) cycling and storage. We present the current understanding of the importance of microbial substrate use efficiency and C and N allocation in controlling the proportion of plant-derived C and N that is incorporated into SOM, and of soil matrix interactions in controlling SOM stabilization. We synthesize this understanding into the Microbial Efficiency-Matrix Stabilization (MEMS) framework. This framework leads to the hypothesis that labile plant constituents are the dominant source of microbial products, relative to input rates, because they are utilized more efficiently by microbes. These microbial products of decomposition would thus become the main precursors of stable SOM by promoting aggregation and through strong chemical bonding to the mineral soil matrix. © 2012 Blackwell Publishing Ltd.

  13. Voxel-based gray and white matter morphometry correlates of hallucinations in schizophrenia: The superior temporal gyrus does not stand alone.

    Science.gov (United States)

    van Tol, Marie-José; van der Meer, Lisette; Bruggeman, Richard; Modinos, Gemma; Knegtering, Henderikus; Aleman, André

    2014-01-01

    Auditory verbal hallucinations (AVH) in schizophrenia (SZ) have been proposed to result from abnormal local, interregional and interhemispheric integration of brain signals in regions involved in language production and perception. This abnormal functional integration may find its base in morphological abnormalities. Structurally, AVHs have been frequently linked to abnormal morphology of the superior temporal gyrus (STG), but only a few studies investigated the relation of hallucination presence with both whole-brain gray matter (GM) and white matter (WM) morphometry. Using a unified voxel-based morphometry-DARTEL approach, we investigated correlates of AVH presence in 51 schizophrenia patients (20 non-hallucinating [SZ -], 31 hallucinating [SZ +]), and included 51 age and sex matched healthy participants. Effects are reported at p frontal and right parahippocampal gyrus, and higher WM volume of the left postcentral and superior parietal lobule than controls. Finally, volume of the putamen was lower in SZ + compared to SZ -. No effects on corpus callosum morphometry were observed. Delusion severity, general positive and negative symptomatology illness duration, and medication status could not explain the results. Results suggest that STG GM abnormalities underlie the general susceptibility to experience psychotic symptoms and that additional abnormalities in a network of medial temporal, ventrolateral, putaminal, and parietal regions related to verbal memory and speech production may specifically increase the likelihood of experiencing AVH. Future studies should clarify the meaning of morphometry abnormalities for functional interregional communication.

  14. Spinal cord microstructure integrating phase-sensitive inversion recovery and diffusional kurtosis imaging

    Energy Technology Data Exchange (ETDEWEB)

    Panara, V.; Navarra, R; Caulo, M. [University ' ' G. d' Annunzio' ' , Department of Neuroscience, Imaging and Clinical Sciences, Chieti (Italy); University ' ' G. d' Annunzio' ' , ITAB Institute of Advanced Biomedical Technologies, Chieti (Italy); Mattei, P.A. [University ' ' G. d' Annunzio' ' , ITAB Institute of Advanced Biomedical Technologies, Chieti (Italy); University ' ' G. d' Annunzio' ' , Department of Medicine and Science of Aging, Ophthalmology Clinic, Chieti (Italy); Piccirilli, E. [University ' ' G. d' Annunzio' ' , ITAB Institute of Advanced Biomedical Technologies, Chieti (Italy); Cotroneo, A.R.; Uncini, A. [University ' ' G. d' Annunzio' ' , Department of Neuroscience, Imaging and Clinical Sciences, Chieti (Italy); Papinutto, N.; Henry, R.G. [University of California, San Francisco, Department of Neurology, San Francisco, CA (United States)

    2017-08-15

    The aim of this prospective study was to determine the feasibility in terms of repeatability and reproducibility of diffusional kurtosis imaging (DKI) for microstructural assessment of the normal cervical spinal cord (cSC) using a phase-sensitive inversion recovery (PSIR) sequence as the anatomical reference for accurately defining white-matter (WM) and gray-matter (GM) regions of interests (ROIs). Thirteen young healthy subjects were enrolled to undergo DKI and PSIR sequences in the cSC. The repeatability and reproducibility of kurtosis metrics and fractional anisotropy (FA) were calculated in GM, WM, and cerebral-spinal-fluid (CSF) ROIs drawn by two independent readers on PSIR images of three different levels (C1-C4). The presence of statistically significant differences in DKI metrics for levels, ROIs (GM, WM, and CSF) repeatability, reproducibility, and inter-reader agreement was evaluated. Intra-class correlation coefficients between the two readers ranged from good to excellent (0.75 to 0.90). The inferior level consistently had the highest concordance. The lower values of scan-rescan variability for all DKI parameters were found for the inferior level. Statistically significant differences in kurtosis values were not found in the lateral white-matter bundles of the spinal cord. The integration of DKI and PSIR sequences in a clinical MR acquisition to explore the regional microstructure of the cSC in healthy subjects is feasible, and the results obtainable are reproducible. Further investigation will be required to verify the possibility to translate this method to a clinical setting to study patients with SC involvement especially in the absence of MRI abnormalities on standard sequences. (orig.)

  15. Effects of VRK2 (rs2312147 on white matter connectivity in patients with schizophrenia.

    Directory of Open Access Journals (Sweden)

    Hoyoung Sohn

    Full Text Available Recent genome-wide association studies of schizophrenia reported a novel risk variant, rs2312147 at vaccinia-related kinase 2 gene (VRK2, in multiple Asian and European samples. However, its effect on the brain structure in schizophrenia is little known. We analyzed the brain structure of 36 schizophrenia patients and 18 healthy subjects with regard to rs2312147 genotype groups. Brain magnetic resonance scans for gray matter (GM and white matter (WM analysis, and genotype analysis for VRK2 rs2312147, were conducted. The Positive and Negative Syndrome Scale and the Digit Symbol Test were assessed for schizophrenia patients. There was no significant difference in either GM volume or WM connectivity with regard to rs2312147 genotype in healthy subjects. In contrast, we found significant differences in the WM connectivity between rs2312147 CC and CT/TT genotype groups of schizophrenia patients. The related brain areas included the splenium of corpus callosum, the left occipital lobe WM, the internal capsule (left anterior limb and right retrolenticular part, the bilateral temporal lobe WM, the left fornix/stria terminalis, the left cingulate gyrus WM, and the left parietal lobe WM. Voxelwise correlation analysis revealed that the Digit Symbol Test scores (age corrected correlated with the fractional anisotropy in WM tracts that previously showed significant group differences between the CT/TT and CC genotypes in the rs2312147 CT/TT genotype group, while no significant correlation was found in the CC genotype group. Our data may provide evidence for the effect of VRK2 on WM connectivity in patients with schizophrenia.

  16. Heterochronicity of white matter development and aging explains regional patient control differences in schizophrenia.

    Science.gov (United States)

    Kochunov, Peter; Ganjgahi, Habib; Winkler, Anderson; Kelly, Sinead; Shukla, Dinesh K; Du, Xiaoming; Jahanshad, Neda; Rowland, Laura; Sampath, Hemalatha; Patel, Binish; O'Donnell, Patricio; Xie, Zhiyong; Paciga, Sara A; Schubert, Christian R; Chen, Jian; Zhang, Guohao; Thompson, Paul M; Nichols, Thomas E; Hong, L Elliot

    2016-12-01

    Altered brain connectivity is implicated in the development and clinical burden of schizophrenia. Relative to matched controls, schizophrenia patients show (1) a global and regional reduction in the integrity of the brain's white matter (WM), assessed using diffusion tensor imaging (DTI) fractional anisotropy (FA), and (2) accelerated age-related decline in FA values. In the largest mega-analysis to date, we tested if differences in the trajectories of WM tract development influenced patient-control differences in FA. We also assessed if specific tracts showed exacerbated decline with aging. Three cohorts of schizophrenia patients (total n = 177) and controls (total n = 249; age = 18-61 years) were ascertained with three 3T Siemens MRI scanners. Whole-brain and regional FA values were extracted using ENIGMA-DTI protocols. Statistics were evaluated using mega- and meta-analyses to detect effects of diagnosis and age-by-diagnosis interactions. In mega-analysis of whole-brain averaged FA, schizophrenia patients had lower FA (P = 10 -11 ) and faster age-related decline in FA (P = 0.02) compared with controls. Tract-specific heterochronicity measures, that is, abnormal rates of adolescent maturation and aging explained approximately 50% of the regional variance effects of diagnosis and age-by-diagnosis interaction in patients. Interactive, three-dimensional visualization of the results is available at www.enigma-viewer.org. WM tracts that mature later in life appeared more sensitive to the pathophysiology of schizophrenia and were more susceptible to faster age-related decline in FA values. Hum Brain Mapp 37:4673-4688, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Effect of Simulated Microgravity on Human Brain Gray Matter and White Matter--Evidence from MRI.

    Directory of Open Access Journals (Sweden)

    Ke Li

    Full Text Available There is limited and inconclusive evidence that space environment, especially microgravity condition, may affect microstructure of human brain. This experiment hypothesized that there would be modifications in gray matter (GM and white matter (WM of the brain due to microgravity.Eighteen male volunteers were recruited and fourteen volunteers underwent -6° head-down bed rest (HDBR for 30 days simulated microgravity. High-resolution brain anatomical imaging data and diffusion tensor imaging images were collected on a 3T MR system before and after HDBR. We applied voxel-based morphometry and tract-based spatial statistics analysis to investigate the structural changes in GM and WM of brain.We observed significant decreases of GM volume in the bilateral frontal lobes, temporal poles, parahippocampal gyrus, insula and right hippocampus, and increases of GM volume in the vermis, bilateral paracentral lobule, right precuneus gyrus, left precentral gyrus and left postcentral gyrus after HDBR. Fractional anisotropy (FA changes were also observed in multiple WM tracts.These regions showing GM changes are closely associated with the functional domains of performance, locomotion, learning, memory and coordination. Regional WM alterations may be related to brain function decline and adaption. Our findings provide the neuroanatomical evidence of brain dysfunction or plasticity in microgravity condition and a deeper insight into the cerebral mechanisms in microgravity condition.

  18. Reduced white matter MRI transverse relaxation rate in cognitively normal H63D-HFE human carriers and H67D-HFE mice.

    Science.gov (United States)

    Meadowcroft, Mark D; Wang, Jianli; Purnell, Carson J; Peters, Douglas G; Eslinger, Paul J; Neely, Elizabeth B; Gill, David J; Vasavada, Megha; Ali-Rahmani, Fatima; Yang, Qing X; Connor, James R

    2016-12-01

    Mutations within the HFE protein gene sequence have been associated with increased risk of developing a number of neurodegenerative disorders. To this effect, an animal model has been created which incorporates the mouse homologue to the human H63D-HFE mutation: the H67D-HFE knock-in mouse. These mice exhibit alterations in iron management proteins, have increased neuronal oxidative stress, and a disruption in cholesterol regulation. However, it remains undetermined how these differences translate to human H63D carriers in regards to white matter (WM) integrity. To this endeavor, MRI transverse relaxation rate (R 2 ) parametrics were employed to test the hypothesis that WM alterations are present in H63D human carriers and are recapitulated in the H67D mice. H63D carriers exhibit widespread reductions in brain R 2 compared to non-carriers within white matter association fibers in the brain. Similar R 2 decreases within white matter tracts were observed in the H67D mouse brain. Additionally, an exacerbation of age-related R 2 decrease is found in the H67D animal model in white matter regions of interest. The decrease in R 2 within white matter tracts of both species is speculated to be multifaceted. The R 2 changes are hypothesized to be due to alterations in axonal biochemical tissue composition. The R 2 changes observed in both the human-H63D and mouse-H67D data suggest that modified white matter myelination is occurring in subjects with HFE mutations, potentially increasing vulnerability to neurodegenerative disorders.

  19. Genetic effect of interleukin-1 beta (C-511T) polymorphism on the structural covariance network and white matter integrity in Alzheimer's disease.

    Science.gov (United States)

    Huang, Chi-Wei; Hsu, Shih-Wei; Tsai, Shih-Jen; Chen, Nai-Ching; Liu, Mu-En; Lee, Chen-Chang; Huang, Shu-Hua; Chang, Weng-Neng; Chang, Ya-Ting; Tsai, Wan-Chen; Chang, Chiung-Chih

    2017-01-18

    Inflammatory processes play a pivotal role in the degenerative process of Alzheimer's disease. In humans, a biallelic (C/T) polymorphism in the promoter region (position-511) (rs16944) of the interleukin-1 beta gene has been significantly associated with differences in the secretory capacity of interleukin-1 beta. In this study, we investigated whether this functional polymorphism mediates the brain networks in patients with Alzheimer's disease. We enrolled a total of 135 patients with Alzheimer's disease (65 males, 70 females), and investigated their gray matter structural covariance networks using 3D T1 magnetic resonance imaging and their white matter macro-structural integrities using fractional anisotropy. The patients were classified into two genotype groups: C-carriers (n = 108) and TT-carriers (n = 27), and the structural covariance networks were constructed using seed-based analysis focusing on the default mode network medial temporal or dorsal medial subsystem, salience network and executive control network. Neurobehavioral scores were used as the major outcome factors for clinical correlations. There were no differences between the two genotype groups in the cognitive test scores, seed, or peak cluster volumes and white matter fractional anisotropy. The covariance strength showing C-carriers > TT-carriers was the entorhinal-cingulum axis. There were two peak clusters (Brodmann 6 and 10) in the salience network and four peak clusters (superior prefrontal, precentral, fusiform, and temporal) in the executive control network that showed C-carriers covariance strength. The salience network and executive control network peak clusters in the TT group and the default mode network peak clusters in the C-carriers strongly predicted the cognitive test scores. Interleukin-1 beta C-511 T polymorphism modulates the structural covariance strength on the anterior brain network and entorhinal-interconnected network which were independent of the white

  20. Distinct white matter integrity in glutamic acid decarboxylase and voltage-gated potassium channel-complex antibody-associated limbic encephalitis.

    Science.gov (United States)

    Wagner, Jan; Schoene-Bake, Jan-Christoph; Witt, Juri-Alexander; Helmstaedter, Christoph; Malter, Michael P; Stoecker, Winfried; Probst, Christian; Weber, Bernd; Elger, Christian E

    2016-03-01

    Autoantibodies against glutamic acid decarboxylase (GAD) and the voltage-gated potassium channel (VGKC) complex are associated with distinct subtypes of limbic encephalitis regarding clinical presentation, response to therapy, and outcome. The aim of this study was to investigate white matter changes in these two limbic encephalitis subtypes by means of diffusion tensor imaging (DTI). Diffusion data were obtained in 14 patients with GAD antibodies and 16 patients with VGKC-complex antibodies and compared with age- and gender-matched control groups. Voxelwise statistical analysis was carried out using tract-based spatial statistics. The results were furthermore compared with those of 15 patients with unilateral histologically confirmed hippocampal sclerosis and correlated with verbal and figural memory performance. We found widespread changes of fractional anisotropy and all diffusivity parameters in GAD-associated limbic encephalitis, whereas no changes were found in VGKC-complex-associated limbic encephalitis. The changes observed in the GAD group were even more extensive when compared against those of the hippocampal sclerosis group, although the disease duration was markedly shorter in patients with GAD antibodies. Correlation analysis revealed areas with a trend toward a negative correlation of diffusivity parameters with figural memory performance located mainly in the right temporal lobe in the GAD group as well. The present study provides further evidence that, depending on the associated antibody, limbic encephalitis features clearly distinct imaging characteristics by showing widespread white matter changes in GAD-associated limbic encephalitis and preserved white matter integrity in VGKC-complex-associated limbic encephalitis. Furthermore, our results contribute to a better understanding of the specific pathophysiologic properties in these two subforms of limbic encephalitis by revealing that patients with GAD antibodies show widespread affections of

  1. The Quest for Dark Matter

    CERN Document Server

    Rubbia, Carlo

    2005-01-01

    Recent experiments have brought for the first time under a strong experimental basis that the total density of the Universe is Wo = 1.02 ± 0.02. We have for the first time a cosmic agreement, namely matter density WM = 0.27 ± 0.04 and dark energy density WL = 0.73 ± 0.04 add up precisely to Wo ! WM + WL. On the other hand ordinary hadronic matter (quarks and leptons) determined by the Big Bang Nucleo-synthesis (BBN) is also firmly set to WBBN = 0.044 ± 0.004. About 100 years after Einstein's birth we know experimentally the identity of less than 5% of what the Universe is made of, the remaining > 95% escaping to us completely. An enormous effort is being made at LHC in order to discover SUSY particles. SUSY is an “almost necessity” of elementary particle physics. The fact that such particles may also account for the observed non baryonic dark matter is either a big coincidence or a big hint. If such SUSY particles indeed exist, they must have been...

  2. Interaction of the radiation with matter

    International Nuclear Information System (INIS)

    2013-01-01

    This third chapter presents the ionization, excitation, activation and radiation breaking; radiation directly and indirectly ionizing; interaction of the electromagnetic radiation with matter; interaction of neutrons with matter; interaction of radiation directly ionizing with matter; interaction of electrons with matter, interaction of alpha particle with matter; interaction of fission fragments with matter; travel time and integrated processes of interaction: energy dissipation

  3. Integration of Sparse Multi-modality Representation and Geometrical Constraint for Isointense Infant Brain Segmentation

    OpenAIRE

    Wang, Li; Shi, Feng; Li, Gang; Lin, Weili; Gilmore, John H.; Shen, Dinggang

    2013-01-01

    Segmentation of infant brain MR images is challenging due to insufficient image quality, severe partial volume effect, and ongoing maturation and myelination process. During the first year of life, the signal contrast between white matter (WM) and gray matter (GM) in MR images undergoes inverse changes. In particular, the inversion of WM/GM signal contrast appears around 6–8 months of age, where brain tissues appear isointense and hence exhibit extremely low tissue contrast, posing significan...

  4. Dry matter yield and forage quality traits of oat (Avena sativa L. under integrative use of microbial and synthetic source of nitrogen

    Directory of Open Access Journals (Sweden)

    M. Bilal

    2017-07-01

    Full Text Available The natural microbes are potential contributor to build up soil nitrogen through transformation of molecular nitrogen to plant available forms. Therefore, in the present study, we investigated the contribution of biofertilizer to reduce the synthetic nitrogen application without deteriorating the yield and forage quality. The supplementary nitrogen rates included 0, 40, 80 and 120 kg ha−1 and the seed inoculation was carried out with the mixture of Azospirillum + Azotobacter spp. The experiment was laid out in randomized complete block design with factorial arrangement. The results indicated that organic matter contents and ether extractable fat were negatively associated with both nitrogen and inoculation factors. The inoculation produced 6.58%, 9.58%, 2.51%, 16.94%, 10.26%, 17.59%, 14.02%, 33.81% and 66.18% more No. tillers, plant height, leaf to stem ratio, dry matter yield, mineral matter contents, crude fibre, crude protein, crude protein yield and total digestible crude protein yield, respectively over uninoculation. The interactive effects indicated that inoculation alone without nitrogen application produced 19.16% and 6.87% more dry matter yield and crude protein (%, respectively. The beneficiary effects of biofertilizers on growth and dry matter of oat were more pronounced at intermediate level of inorganic nitrogen which was gradually decreased at higher nitrogen levels. The CP, CPY and DCPY achieved with inoculation alone were statistically equivalent to plots fertilized with 0 and 40 kg N ha−1. It is clear that plots sown with inoculated seeds must be fertilized with 80 kg N to produce higher dry matter and economic returns. However, the highest protein contents in dry matter were recorded with highest fertilization level along with inoculation. By giving due attention to stimulatory effects of bacterial species in the present study, it is therefore, recommended to integrate the use of biofertilizers with supplemental

  5. The use of the lumbosacral enlargement as an intrinsic imaging biomarker: feasibility of grey matter and white matter cross-sectional area measurements using MRI at 3T.

    Directory of Open Access Journals (Sweden)

    Marios C Yiannakas

    Full Text Available Histopathological studies have demonstrated the involvement of spinal cord grey matter (GM and white matter (WM in several diseases and recent research has suggested the use of magnetic resonance imaging (MRI as a promising tool for in vivo assessment of the upper spinal cord. However, many neurological conditions would benefit from quantitative assessment of tissue integrity at different levels and relatively little work has been done, mainly due to technical challenges associated with imaging the lower spinal cord. In this study, the value of the lumbosacral enlargement (LSE as an intrinsic imaging biomarker was determined by exploring the feasibility of obtaining within it reliable GM and WM cross-sectional area (CSA measurements by means of a commercially available MRI system at 3 tesla (T. 10 healthy volunteers (mean age 27.5 years, 6 female gave written informed consent and high resolution images of the LSE were acquired and analysed using an optimised MRI acquisition and analysis protocol. GM and WM mean CSA measurements were obtained from a 15 mm section at the level of the LSE and the reproducibility of the measurements was determined by means of scan-rescan, intra- and inter-observer assessments. Mean (±SD LSE cross-sectional area (LSE-CSA was 62.3 (±4.1 mm2 and mean (±SD LSE grey matter cross-sectional area (LSE-GM-CSA was 19.8 (±3.3 mm2. The mean scan-rescan, intra- and inter-observer % coefficient of variation (COV for measuring the LSE-CSA were 2%, 2% and 2.5%, respectively and for measuring the LSE-GM-CSA were 7.8%, 8% and 8.6%, respectively. This study has shown that the LSE can be used reliably as an intrinsic imaging biomarker. The method presented here can be potentially extended to study the LSE in the diseased state and could provide a solid foundation for subsequent multi-parametric MRI investigations.

  6. Performance of five research-domain automated WM lesion segmentation methods in a multi-center MS study

    DEFF Research Database (Denmark)

    de Sitter, Alexandra; Steenwijk, Martijn D; Ruet, Aurélie

    2017-01-01

    (Lesion-TOADS); and k-Nearest Neighbor with Tissue Type Priors (kNN-TTP). Main software parameters were optimized using a training set (N = 18), and formal testing was performed on the remaining patients (N = 52). To evaluate volumetric agreement with the reference segmentations, intraclass correlation......BACKGROUND AND PURPOSE: In vivoidentification of white matter lesions plays a key-role in evaluation of patients with multiple sclerosis (MS). Automated lesion segmentation methods have been developed to substitute manual outlining, but evidence of their performance in multi-center investigations......-one-center-out design to exclude the center of interest from the training phase to evaluate the performance of the method on 'unseen' center. RESULTS: Compared to the reference mean lesion volume (4.85 ± 7.29 mL), the methods displayed a mean difference of 1.60 ± 4.83 (Cascade), 2.31 ± 7.66 (LGA), 0.44 ± 4.68 (LPA), 1...

  7. Evaluation of white matter integrity in systemic lupus erythematosus by diffusion tensor magnetic resonance imaging: a study using tract-based spatial statistics

    International Nuclear Information System (INIS)

    Goulart Correa, Diogo; Ventura, Nina; Gasparetto, Emerson Leandro; Zimmermann, Nicolle; Paz Fonseca, Rochele; Batista Pereira, Denis; Netto, Tania Maria; Doring, Thomas M.

    2016-01-01

    The aim of this study was to evaluate the white matter integrity in brains of patients with systemic lupus erythematosus (SLE) using a voxel-based analyses of diffusion tensor imaging (DTI) data. Fifty-seven patients with SLE were compared to 36 control patients who were matched by gender, age, education, and Mini Mental State Examination score. DTI was performed along 30 noncollinear directions in a 1.5 Tesla scanner. For tract-based spatial statistics (TBSS), a white matter skeleton was created, and a permutation-based inference with 5000 permutations and a threshold of p < 0.05 was used to identify abnormalities in fractional anisotropy (FA). The mean (MD), radial (RD), and axial diffusivities (AD) were also projected onto the mean FA skeleton. We found a significant decrease of global FA in SLE patients compared to controls. The areas of reduced FA included the right superior corona radiata, the right superior longitudinal fasciculus, the body of the corpus callosum, the right inferior fronto-occipital fasciculus, the right thalamic radiation, and the right uncinate fasciculus. Patients with SLE also had increased AD and RD in several areas. Substantial overlap of areas with increased AD and RD occurred and were spatially much more extensive than the areas of reduced FA. Significant increases of AD values were concordant to those of RD and MD and more extensive than FA changes. Analyzing all diffusivity parameters, using TBSS, can detect more white matter microstructural changes in patients with SLE than analyzing FA alone. (orig.)

  8. Evaluation of white matter integrity in systemic lupus erythematosus by diffusion tensor magnetic resonance imaging: a study using tract-based spatial statistics

    Energy Technology Data Exchange (ETDEWEB)

    Goulart Correa, Diogo; Ventura, Nina; Gasparetto, Emerson Leandro [Federal University of Rio de Janeiro, Department of Radiology, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro, RJ (Brazil); Zimmermann, Nicolle; Paz Fonseca, Rochele [Federal University of Rio de Janeiro, Department of Radiology, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Pontifical Catholic University of Rio Grande do Sul, Department of Psychology, Porto Alegre, RS (Brazil); Batista Pereira, Denis; Netto, Tania Maria [Federal University of Rio de Janeiro, Department of Radiology, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Doring, Thomas M. [Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro, RJ (Brazil)

    2016-08-15

    The aim of this study was to evaluate the white matter integrity in brains of patients with systemic lupus erythematosus (SLE) using a voxel-based analyses of diffusion tensor imaging (DTI) data. Fifty-seven patients with SLE were compared to 36 control patients who were matched by gender, age, education, and Mini Mental State Examination score. DTI was performed along 30 noncollinear directions in a 1.5 Tesla scanner. For tract-based spatial statistics (TBSS), a white matter skeleton was created, and a permutation-based inference with 5000 permutations and a threshold of p < 0.05 was used to identify abnormalities in fractional anisotropy (FA). The mean (MD), radial (RD), and axial diffusivities (AD) were also projected onto the mean FA skeleton. We found a significant decrease of global FA in SLE patients compared to controls. The areas of reduced FA included the right superior corona radiata, the right superior longitudinal fasciculus, the body of the corpus callosum, the right inferior fronto-occipital fasciculus, the right thalamic radiation, and the right uncinate fasciculus. Patients with SLE also had increased AD and RD in several areas. Substantial overlap of areas with increased AD and RD occurred and were spatially much more extensive than the areas of reduced FA. Significant increases of AD values were concordant to those of RD and MD and more extensive than FA changes. Analyzing all diffusivity parameters, using TBSS, can detect more white matter microstructural changes in patients with SLE than analyzing FA alone. (orig.)

  9. An Example-Based Multi-Atlas Approach to Automatic Labeling of White Matter Tracts.

    Science.gov (United States)

    Yoo, Sang Wook; Guevara, Pamela; Jeong, Yong; Yoo, Kwangsun; Shin, Joseph S; Mangin, Jean-Francois; Seong, Joon-Kyung

    2015-01-01

    We present an example-based multi-atlas approach for classifying white matter (WM) tracts into anatomic bundles. Our approach exploits expert-provided example data to automatically classify the WM tracts of a subject. Multiple atlases are constructed to model the example data from multiple subjects in order to reflect the individual variability of bundle shapes and trajectories over subjects. For each example subject, an atlas is maintained to allow the example data of a subject to be added or deleted flexibly. A voting scheme is proposed to facilitate the multi-atlas exploitation of example data. For conceptual simplicity, we adopt the same metrics in both example data construction and WM tract labeling. Due to the huge number of WM tracts in a subject, it is time-consuming to label each WM tract individually. Thus, the WM tracts are grouped according to their shape similarity, and WM tracts within each group are labeled simultaneously. To further enhance the computational efficiency, we implemented our approach on the graphics processing unit (GPU). Through nested cross-validation we demonstrated that our approach yielded high classification performance. The average sensitivities for bundles in the left and right hemispheres were 89.5% and 91.0%, respectively, and their average false discovery rates were 14.9% and 14.2%, respectively.

  10. A Whole-Brain Investigation of White Matter Microstructure in Adolescents with Conduct Disorder.

    Directory of Open Access Journals (Sweden)

    Sagari Sarkar

    Full Text Available The biological basis of severe antisocial behaviour in adolescents is poorly understood. We recently reported that adolescents with conduct disorder (CD have significantly increased fractional anisotropy (FA of the uncinate fasciculus (a white matter (WM tract that connects the amygdala to the frontal lobe compared to their non-CD peers. However, the extent of WM abnormality in other brain regions is currently unclear.We used tract-based spatial statistics to investigate whole brain WM microstructural organisation in 27 adolescent males with CD, and 21 non-CD controls. We also examined relationships between FA and behavioural measures. Groups did not differ significantly in age, ethnicity, or substance use history.The CD group, compared to controls, had clusters of significantly greater FA in 7 brain regions corresponding to: 1 the bilateral inferior and superior cerebellar peduncles, corticopontocerebellar tract, posterior limb of internal capsule, and corticospinal tract; 2 right superior longitudinal fasciculus; and 3 left cerebellar WM. Severity of antisocial behavior and callous-unemotional symptoms were significantly correlated with FA in several of these regions across the total sample, but not in the CD or control groups alone.Adolescents with CD have significantly greater FA than controls in WM regions corresponding predominantly to the fronto-cerebellar circuit. There is preliminary evidence that variation in WM microstructure may be dimensionally related to behaviour problems in youngsters. These findings are consistent with the hypothesis that antisocial behaviour in some young people is associated with abnormalities in WM 'connectivity'.

  11. A Whole-Brain Investigation of White Matter Microstructure in Adolescents with Conduct Disorder.

    Science.gov (United States)

    Sarkar, Sagari; Dell'Acqua, Flavio; Froudist Walsh, Seán; Blackwood, Nigel; Scott, Stephen; Craig, Michael C; Deeley, Quinton; Murphy, Declan G M

    2016-01-01

    The biological basis of severe antisocial behaviour in adolescents is poorly understood. We recently reported that adolescents with conduct disorder (CD) have significantly increased fractional anisotropy (FA) of the uncinate fasciculus (a white matter (WM) tract that connects the amygdala to the frontal lobe) compared to their non-CD peers. However, the extent of WM abnormality in other brain regions is currently unclear. We used tract-based spatial statistics to investigate whole brain WM microstructural organisation in 27 adolescent males with CD, and 21 non-CD controls. We also examined relationships between FA and behavioural measures. Groups did not differ significantly in age, ethnicity, or substance use history. The CD group, compared to controls, had clusters of significantly greater FA in 7 brain regions corresponding to: 1) the bilateral inferior and superior cerebellar peduncles, corticopontocerebellar tract, posterior limb of internal capsule, and corticospinal tract; 2) right superior longitudinal fasciculus; and 3) left cerebellar WM. Severity of antisocial behavior and callous-unemotional symptoms were significantly correlated with FA in several of these regions across the total sample, but not in the CD or control groups alone. Adolescents with CD have significantly greater FA than controls in WM regions corresponding predominantly to the fronto-cerebellar circuit. There is preliminary evidence that variation in WM microstructure may be dimensionally related to behaviour problems in youngsters. These findings are consistent with the hypothesis that antisocial behaviour in some young people is associated with abnormalities in WM 'connectivity'.

  12. Diffusion-weighted MRI measures suggest increased white-matter integrity in Internet gaming disorder: Evidence from the comparison with recreational Internet game users.

    Science.gov (United States)

    Dong, Guangheng; Wu, Lingdan; Wang, Ziliang; Wang, Yifan; Du, Xiaoxia; Potenza, Marc N

    2018-06-01

    Several studies have suggested that Internet gaming disorder (IGD) is related to altered brain white matter integrity. However, seeming inconsistencies exist and may reflect comparison groups not matched well for certain gaming characteristics. In order to address this possible concern, we recruited in the present study individuals with recreational Internet game use (RGU) comprised of individuals who spend similar amounts of time as IGD subjects playing online games without developing IGD. Diffusion tensor imaging data were collected from 42 IGD and 44 RGU subjects. Whole-brain comparisons showed that IGD subjects demonstrated increased fractional anisotropy (FA) in the bilateral anterior thalamic radiation, anterior limb of the internal capsule, bilateral corticospinal tract, bilateral inferior fronto-occipital fasciculus, corpus callosum, and bilateral inferior longitudinal fasciculus. In addition, Internet-addiction severity was positively correlated with FA values. Taken together, we conclude that IGD is associated with measures of increased white-matter integrity in tracts linking reward circuitry and sensory and motor control systems. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Optimization of a Clinically Relevant Model of White Matter Stroke in Mice: Histological and Functional Evidences

    Science.gov (United States)

    Ahmad, Abdullah S.; Satriotomo, Irawan; Fazal, Jawad A.; Nadeau, Stephen E.; Doré, Sylvain

    2015-01-01

    Background and Purpose White matter (WM) injury during stroke increases the risk of disability and gloomy prognosis of post-stroke rehabilitation. However, modeling of WM loss in rodents has proven to be challenging. Methods We report improved WM injury models in male C57BL/6 mice. Mice were given either endothelin-1 (ET-1) or L-N5-(1-iminoethyl)ornitine (L-NIO) into the periventricular white matter (PVWM), in the corpus callosum (CC), or in the posterior limb of internal capsule (PLIC). Anatomical and functional outcomes were quantified on day 7 post injection. Results Injection of ET-1 or L-NIO caused a small focal lesion in the injection site in the PVWM. No significant motor function deficits were observed in the PVWM lesion model. We next targeted the PLIC by using single or double injections of L-NIO and found that this strategy induced small focal infarction. Interestingly, injection of L-NIO in the PLIC also resulted in gliosis, and significant motor function deficits. Conclusions By employing different agents, doses, and locations, this study shows the feasibility of inducing brain WM injury accompanied with functional deficits in mice. Selective targeting of the injury location, behavioral testing, and the agents chosen to induce WM injury are all keys to successfully develop a mouse model and subsequent testing of therapeutic interventions against WM injury. PMID:27512724

  14. References for HNF-SD-WM-TRD-007, ''System specification for the double-shell tank system: HNF-PROs, CFRs, DOE Orders, WACs''

    International Nuclear Information System (INIS)

    Shaw, C.P.

    1998-01-01

    HNF-SD-WM-TRD-O07, System Specification for the Double-Shell Tank System, (hereafter referred to as DST Specification), defines the requirements of the double-shell tank system at the Hanford Site for Phase 1 privatization. Many of the sections in this document reference other documents for design guidance and requirements. Referenced documents include Project Hanford Management Contract (PHMC) procedures (HNF-PROS), Codes of Federal Regulation (CFRs), DOE Orders, and Washington Administrative Codes (WACs). This document provides rationale for the selection and inclusion of HNF-PROS, CFRs, DOE Orders and WACs

  15. DEWS (DEep White matter hyperintensity Segmentation framework): A fully automated pipeline for detecting small deep white matter hyperintensities in migraineurs.

    Science.gov (United States)

    Park, Bo-Yong; Lee, Mi Ji; Lee, Seung-Hak; Cha, Jihoon; Chung, Chin-Sang; Kim, Sung Tae; Park, Hyunjin

    2018-01-01

    Migraineurs show an increased load of white matter hyperintensities (WMHs) and more rapid deep WMH progression. Previous methods for WMH segmentation have limited efficacy to detect small deep WMHs. We developed a new fully automated detection pipeline, DEWS (DEep White matter hyperintensity Segmentation framework), for small and superficially-located deep WMHs. A total of 148 non-elderly subjects with migraine were included in this study. The pipeline consists of three components: 1) white matter (WM) extraction, 2) WMH detection, and 3) false positive reduction. In WM extraction, we adjusted the WM mask to re-assign misclassified WMHs back to WM using many sequential low-level image processing steps. In WMH detection, the potential WMH clusters were detected using an intensity based threshold and region growing approach. For false positive reduction, the detected WMH clusters were classified into final WMHs and non-WMHs using the random forest (RF) classifier. Size, texture, and multi-scale deep features were used to train the RF classifier. DEWS successfully detected small deep WMHs with a high positive predictive value (PPV) of 0.98 and true positive rate (TPR) of 0.70 in the training and test sets. Similar performance of PPV (0.96) and TPR (0.68) was attained in the validation set. DEWS showed a superior performance in comparison with other methods. Our proposed pipeline is freely available online to help the research community in quantifying deep WMHs in non-elderly adults.

  16. Characterization of Functional and Structural Integrity in Experimental Focal Epilepsy: Reduced Network Efficiency Coincides with White Matter Changes

    NARCIS (Netherlands)

    Otte, W.M.; Dijkhuizen, R.M.; van Meer, M.P.A.; Van der Hel, W.S.; Verlinde, S.A.M.W.; van Nieuwenhuizen, O.; Viergever, M.A.; Stam, C.J.; Braun, K.P.J.

    2012-01-01

    Background: Although focal epilepsies are increasingly recognized to affect multiple and remote neural systems, the underlying spatiotemporal pattern and the relationships between recurrent spontaneous seizures, global functional connectivity, and structural integrity remain largely unknown.

  17. Age-related reduction of adaptive brain response during semantic integration is associated with gray matter reduction

    OpenAIRE

    Zhu, Zude; Yang, Fengjun; Li, Dongning; Zhou, Lianjun; Liu, Ying; Zhang, Ying; Chen, Xuezhi

    2017-01-01

    While aging is associated with increased knowledge, it is also associated with decreased semantic integration. To investigate brain activation changes during semantic integration, a sample of forty-eight 25-75 year-old adults read sentences with high cloze (HC) and low cloze (LC) probability while functional magnetic resonance imaging was conducted. Significant age-related reduction of cloze effect (LC vs. HC) was found in several regions, especially the left middle frontal gyrus (MFG) and ri...

  18. New MRI technologies. Diffusion MRI and its application to functional neuroimaging and analyses of white matter integrity

    International Nuclear Information System (INIS)

    Kobayashi, Tetsuo

    2010-01-01

    Described is the technological aspect of MRI, MR diffusion-weighted imaging (MR-DWI), principles of its measurement and application for imaging the cerebral function and for aiding the quantitative diagnosis of brain diseases. The author explains the principle of MR imaging process; diffusion properties of water molecules, MR-DWI based on them and DW-fMRI of the brain; MR-diffusion tensor imaging (MR-DTI), its analysis and color acquisition, and tracking of white matter nerve fibers; analysis of white matter lesions by the tracking; and the new tracking method at the chiasm of nerve fascicles. The usual fMRI reflects the blood oxygen level depending (BOLD) signals whereas recently attracted DW-fMRI, the volume changes of nerve cells concomitant to nerve activation accompanying apparent changes of water diffusion coefficients in and out of cells which occur faster than BOLD signs, resulting in higher resolution of time and space. However, DWI requires the higher intensity of static magnetic field like 3T. MR-DTI acquires the anisotropic diffusion of water molecules using MR-DWI technique with application of 6 or more motion probing gradients, thus makes it possible to track the running directions of nerve fibers and capillary vessels, and is proposed to be a useful mean of specific fiber tracking in the white matter when displayed by 3 different colors exhibiting the directions like the right/left (x axis, red), anterior/posterior (y, green) and upper/lower (z, blue) sides of head. Recently, MR-DWI and MR-DTI have been found usable for pathogenic studies of brain diseases such as dementia. Tensor anisotropy is apparently lowered at the chiasm of nerve fascicles, the cause of tracking error, for which authors have developed a new method using the similarity of directional vector, not of tensor, before and behind the chiasm. As exemplified, MRI technology is further advancing even at present. (T.T.)

  19. Progressive white matter microstructure damage in male chronic heroin dependent individuals: a DTI and TBSS study.

    Directory of Open Access Journals (Sweden)

    Yingwei Qiu

    Full Text Available BACKGROUND: To investigate the WM microstructure deficits in heroin dependent individuals (HDIs with different length of heroin dependence, and to investigate whether these WM deficits can be related to the duration of heroin use and to decision-making deficits in HDIs. METHODOLOGY/PRINCIPAL FINDINGS: Thirty-six HDIs [including eighteen sHDIs (duration of heroin dependent is less than 10 years and eighteen lHDIs (duration of dependent is between 10:20 years] and sixteen healthy controls participated in this study. Whole brain voxel-wise analysis of fractional anisotropy (FA, mean diffusivity (MD, axial diffusivity (Da and radial diffusivity (Dr were performed by tract-based spatial statistics (TBSS to localize abnormal WM regions among groups. TBSS demonstrated that sHDIs had significantly lower FA than controls in right orbito-frontal WM, bilateral temporal WM and right parietal WM. The lHDIs had significantly lower FA throughout the brain compared with the controls and sHDIs. The lHDIs had significantly lower Da than controls in bilateral inferior frontaloccipital fasciculus, bilateral splenium of corpus callosum, left inferior longitudinal fasciculus, and had significantly higher Dr than controls in bilateral uncinatus fasciculus, bilateral inferior frontaloccipital fasciculus and bilateral cortical spinal fasciculus. Volume-of-interest (VOI analyses detect the changes of diffusivity indices in the regions with FA abnormalities revealed by control vs sHDIs. In most VOIs, FA reductions were caused by the increase in Dr as well as the decrease in Da. Correlation analysis was used to assess the relationship between FA and behavioral measures in HDIs and controls available. Significantly positively correlations were found between the FA values in the right orbital-frontal WM, right parietal WM and IGT performance. CONCLUSIONS: The extent and severity of WM integrity deficits in HDIs was associated with the length of heroin dependent. Furthermore

  20. Is sequential cranial ultrasound reliable for detection of white matter injury in very preterm infants?

    International Nuclear Information System (INIS)

    Leijser, Lara M.; Steggerda, Sylke J.; Walther, Frans J.; Wezel-Meijler, Gerda van; Bruine, Francisca T. de; Grond, Jeroen van der

    2010-01-01

    Cranial ultrasound (cUS) may not be reliable for detection of diffuse white matter (WM) injury. Our aim was to assess in very preterm infants the reliability of a classification system for WM injury on sequential cUS throughout the neonatal period, using magnetic resonance imaging (MRI) as reference standard. In 110 very preterm infants (gestational age <32 weeks), serial cUS during admission (median 8, range 4-22) and again around term equivalent age (TEA) and a single MRI around TEA were performed. cUS during admission were assessed for presence of WM changes, and contemporaneous cUS and MRI around TEA additionally for abnormality of lateral ventricles. Sequential cUS (from birth up to TEA) and MRI were classified as normal/mildly abnormal, moderately abnormal, or severely abnormal, based on a combination of findings of the WM and lateral ventricles. Predictive values of the cUS classification were calculated. Sequential cUS were classified as normal/mildly abnormal, moderately abnormal, and severely abnormal in, respectively, 22%, 65%, and 13% of infants and MRI in, respectively, 30%, 52%, and 18%. The positive predictive value of the cUS classification for the MRI classification was high for severely abnormal WM (0.79) but lower for normal/mildly abnormal (0.67) and moderately abnormal (0.64) WM. Sequential cUS during the neonatal period detects severely abnormal WM in very preterm infants but is less reliable for mildly and moderately abnormal WM. MRI around TEA seems needed to reliably detect WM injury in very preterm infants. (orig.)

  1. White matter integrity of the medial forebrain bundle and attention and working memory deficits following traumatic brain injury.

    Science.gov (United States)

    Owens, Jacqueline A; Spitz, Gershon; Ponsford, Jennie L; Dymowski, Alicia R; Ferris, Nicholas; Willmott, Catherine

    2017-02-01

    The medial forebrain bundle (MFB) contains ascending catecholamine fibers that project to the prefrontal cortex (PFC). Damage to these fibers following traumatic brain injury (TBI) may alter extracellular catecholamine levels in the PFC and impede attention and working memory ability. This study investigated white matter microstructure of the medial MFB, specifically the supero-lateral branch (slMFB), following TBI, and its association with performance on attention and working memory tasks. Neuropsychological measures of attention and working memory were administered to 20 moderate-severe participants with TBI (posttraumatic amnesia M  = 40.05 ± 37.10 days, median time since injury 10.48 months, range 3.72-87.49) and 20 healthy controls. Probabilistic tractography was used to obtain fractional anisotropy (FA) and mean diffusivity (MD) values for 17 participants with TBI and 20 healthy controls. When compared to controls, participants with TBI were found to have significantly lower FA ( p  attention task, n -back, and Symbol Digit Modalities Test. This study was the first to demonstrate microstructural white matter damage within the slMFB following TBI. However, no evidence was found for an association of alterations to this tract and performance on attentional tasks.

  2. Does company size matter? Validation of an integrative model of safety behavior across small and large construction companies.

    Science.gov (United States)

    Guo, Brian H W; Yiu, Tak Wing; González, Vicente A

    2018-02-01

    Previous safety climate studies primarily focused on either large construction companies or the construction industry as a whole, while little is known about whether company size has significant effects on workers' understanding of safety climate measures and relationships between safety climate factors and safety behavior. Thus, this study aims to: (a) test the measurement equivalence (ME) of a safety climate measure across workers from small and large companies; (b) investigate if company size alters the causal structure of the integrative model developed by Guo, Yiu, and González (2016). Data were collected from 253 construction workers in New Zealand using a safety climate measure. This study used multi-group confirmatory factor analyses (MCFA) to test the measurement equivalence of the safety climate measure and structure invariance of the integrative model. Results indicate that workers from small and large companies understood the safety climate measure in a similar manner. In addition, it was suggested that company size does not change the causal structure and mediational processes of the integrative model. Both measurement equivalence of the safety climate measure and structural invariance of the integrative model were supported by this study. Practical applications: Findings of this study provided strong support for a meaningful use of the safety climate measure across construction companies in different sizes. Safety behavior promotion strategies designed based on the integrative model may be well suited for both large and small companies. Copyright © 2017 National Safety Council and Elsevier Ltd. All rights reserved.

  3. Effects of white matter microstructure on phase and susceptibility maps.

    Science.gov (United States)

    Wharton, Samuel; Bowtell, Richard

    2015-03-01

    To investigate the effects on quantitative susceptibility mapping (QSM) and susceptibility tensor imaging (STI) of the frequency variation produced by the microstructure of white matter (WM). The frequency offsets in a WM tissue sample that are not explained by the effect of bulk isotropic or anisotropic magnetic susceptibility, but rather result from the local microstructure, were characterized for the first time. QSM and STI were then applied to simulated frequency maps that were calculated using a digitized whole-brain, WM model formed from anatomical and diffusion tensor imaging data acquired from a volunteer. In this model, the magnitudes of the frequency contributions due to anisotropy and microstructure were derived from the results of the tissue experiments. The simulations suggest that the frequency contribution of microstructure is much larger than that due to bulk effects of anisotropic magnetic susceptibility. In QSM, the microstructure contribution introduced artificial WM heterogeneity. For the STI processing, the microstructure contribution caused the susceptibility anisotropy to be significantly overestimated. Microstructure-related phase offsets in WM yield artifacts in the calculated susceptibility maps. If susceptibility mapping is to become a robust MRI technique, further research should be carried out to reduce the confounding effects of microstructure-related frequency contributions. © 2014 Wiley Periodicals, Inc.

  4. Integration

    DEFF Research Database (Denmark)

    Emerek, Ruth

    2004-01-01

    Bidraget diskuterer de forskellige intergrationsopfattelse i Danmark - og hvad der kan forstås ved vellykket integration......Bidraget diskuterer de forskellige intergrationsopfattelse i Danmark - og hvad der kan forstås ved vellykket integration...

  5. Media Matter

    Directory of Open Access Journals (Sweden)

    Holger Pötzsch

    2017-02-01

    Full Text Available The present contribution maps materialist advances in media studies. Based on the assumption that matter and materiality constitute significant aspects of communication processes and practices, I introduce four fields of inquiry - technology, political economy, ecology, and the body - and argue that these perspectives enable a more comprehensive understanding of the implications of contemporary technologically afforded forms of interaction. The article shows how each perspective can balance apologetic and apocalyptic approaches to the impact of in particular digital technologies, before it demonstrates the applicability of an integrated framework with reference to the techno-politics of NSA surveillance and the counter-practices of WikiLeaks.

  6. Common variation in the autism risk gene CNTNAP2, brain structural connectivity and multisensory speech integration.

    Science.gov (United States)

    Ross, Lars A; Del Bene, Victor A; Molholm, Sophie; Jae Woo, Young; Andrade, Gizely N; Abrahams, Brett S; Foxe, John J

    2017-11-01

    Three lines of evidence motivated this study. 1) CNTNAP2 variation is associated with autism risk and speech-language development. 2) CNTNAP2 variations are associated with differences in white matter (WM) tracts comprising the speech-language circuitry. 3) Children with autism show impairment in multisensory speech perception. Here, we asked whether an autism risk-associated CNTNAP2 single nucleotide polymorphism in neurotypical adults was associated with multisensory speech perception performance, and whether such a genotype-phenotype association was mediated through white matter tract integrity in speech-language circuitry. Risk genotype at rs7794745 was associated with decreased benefit from visual speech and lower fractional anisotropy (FA) in several WM tracts (right precentral gyrus, left anterior corona radiata, right retrolenticular internal capsule). These structural connectivity differences were found to mediate the effect of genotype on audiovisual speech perception, shedding light on possible pathogenic pathways in autism and biological sources of inter-individual variation in audiovisual speech processing in neurotypicals. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Integration of sparse multi-modality representation and geometrical constraint for isointense infant brain segmentation.

    Science.gov (United States)

    Wang, Li; Shi, Feng; Li, Gang; Lin, Weili; Gilmore, John H; Shen, Dinggang

    2013-01-01

    Segmentation of infant brain MR images is challenging due to insufficient image quality, severe partial volume effect, and ongoing maturation and myelination process. During the first year of life, the signal contrast between white matter (WM) and gray matter (GM) in MR images undergoes inverse changes. In particular, the inversion of WM/GM signal contrast appears around 6-8 months of age, where brain tissues appear isointense and hence exhibit extremely low tissue contrast, posing significant challenges for automated segmentation. In this paper, we propose a novel segmentation method to address the above-mentioned challenge based on the sparse representation of the complementary tissue distribution information from T1, T2 and diffusion-weighted images. Specifically, we first derive an initial segmentation from a library of aligned multi-modality images with ground-truth segmentations by using sparse representation in a patch-based fashion. The segmentation is further refined by the integration of the geometrical constraint information. The proposed method was evaluated on 22 6-month-old training subjects using leave-one-out cross-validation, as well as 10 additional infant testing subjects, showing superior results in comparison to other state-of-the-art methods.

  8. The Plasticity of Brain Gray Matter and White Matter following Lower Limb Amputation

    Directory of Open Access Journals (Sweden)

    Guangyao Jiang

    2015-01-01

    Full Text Available Accumulating evidence has indicated that amputation induces functional reorganization in the sensory and motor cortices. However, the extent of structural changes after lower limb amputation in patients without phantom pain remains uncertain. We studied 17 adult patients with right lower limb amputation and 18 healthy control subjects using T1-weighted magnetic resonance imaging and diffusion tensor imaging. Cortical thickness and fractional anisotropy (FA of white matter (WM were investigated. In amputees, a thinning trend was seen in the left premotor cortex (PMC. Smaller clusters were also noted in the visual-to-motor regions. In addition, the amputees also exhibited a decreased FA in the right superior corona radiata and WM regions underlying the right temporal lobe and left PMC. Fiber tractography from these WM regions showed microstructural changes in the commissural fibers connecting the bilateral premotor cortices, compatible with the hypothesis that amputation can lead to a change in interhemispheric interactions. Finally, the lower limb amputees also displayed significant FA reduction in the right inferior frontooccipital fasciculus, which is negatively correlated with the time since amputation. In conclusion, our findings indicate that the amputation of lower limb could induce changes in the cortical representation of the missing limb and the underlying WM connections.

  9. Dyslexia and voxel-based morphometry: correlations between five behavioural measures of dyslexia and gray and white matter volumes

    NARCIS (Netherlands)

    Tamboer, P.; Scholte, H.S.; Vorst, H.C.M.

    2015-01-01

    In voxel-based morphometry studies of dyslexia, the relation between causal theories of dyslexia and gray matter (GM) and white matter (WM) volume alterations is still under debate. Some alterations are consistently reported, but others failed to reach significance. We investigated GM alterations in

  10. Addiction as an Attachment Disorder: White Matter Impairment Is Linked to Increased Negative Affective States in Poly-Drug Use

    Directory of Open Access Journals (Sweden)

    Eva Z. Reininghaus

    2017-04-01

    Full Text Available Substance use disorders (SUD have been shown to be linked to various neuronal and behavioral impairments. In this study, we investigate whether there is a connection between the integrity of white matter (WM and attachment styles as well as different affective states including spirituality in a group of patients diagnosed for poly-drug use disorder (PUD in comparison to non-clinical controls. A total sample of 59 right-handed men, comprising the groups of patients with PUD (n = 19, recreational drug-using individuals (RUC; n = 20 as well as non-drug using controls were recruited (NUC; n = 20. For the behavioral assessment, we applied the Adult Attachment-Scale, the Affective Neuroscience Personality-Scale (short version and the Multidimensional Inventory for Religious/Spiritual Well-Being. Diffusion Tensor Imaging was used to investigate differences in WM neural connectivity. Analyses revealed decreased Fractional Anisotropy and decreased Mean Diffusivity in PUD patients as compared to RUC and NUC. No differences were found between RUC and NUC. Additional ROI analyses suggested that WM impairment in the superior longitudinal fasciculus (SLF and the superior corona radiata (SCR was linked to more insecure attachment as well as to more negative affectivity. No substantial correlation was observed with spirituality. These findings are mainly limited by the cross-sectional design of the study. However, our preliminary results support the idea of addiction as an attachment disorder, both at neuronal and behavioral levels. Further research might be focused on the changes of insecure attachment patterns in SUD treatment and their correlation with changes in the brain.

  11. White matter alterations in the brains of patients with active, remitted, and cured cushing syndrome: a DTI study.

    Science.gov (United States)

    Pires, P; Santos, A; Vives-Gilabert, Y; Webb, S M; Sainz-Ruiz, A; Resmini, E; Crespo, I; de Juan-Delago, M; Gómez-Anson, B

    2015-06-01

    Cushing syndrome appears after chronic exposure to elevated glucocorticoid levels. Cortisol excess may alter white matter microstructure. Our purpose was to study WM changes in patients with Cushing syndrome compared with controls by using DTI and the influence of hypercortisolism. Thirty-five patients with Cushing syndrome and 35 healthy controls, matched for age, education, and sex, were analyzed through DTI (tract-based spatial statistics) for fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity (general linear model, family-wise error, and threshold-free cluster enhancement corrections, P Cushing syndrome with active hypercortisolism, 7 with Cushing syndrome with medication-remitted cortisol, 20 surgically cured, and 35 controls. Cardiovascular risk factors were used as covariates. In addition, correlations were analyzed among DTI values, concomitant 24-hour urinary free cortisol levels, and disease duration. There were widespread alterations (reduced fractional anisotropy, and increased mean diffusivity, axial diffusivity, and radial diffusivity values; P Cushing syndrome compared with controls, independent of the cardiovascular risk factors present. Both active and cured Cushing syndrome subgroups showed similar changes compared with controls. Patients with medically remitted Cushing syndrome also had reduced fractional anisotropy and increased mean diffusivity and radial diffusivity values, compared with controls. No correlations were found between DTI maps and 24-hour urinary free cortisol levels or with disease duration. Diffuse WM alterations in patients with Cushing syndrome suggest underlying loss of WM integrity and demyelination. Once present, they seem to be independent of concomitant hypercortisolism, persisting after remission/cure. © 2015 by American Journal of Neuroradiology.

  12. Do inclusive work environments matter? Effects of community-integrated employment on quality of life for individuals with intellectual disabilities.

    Science.gov (United States)

    Blick, Rachel N; Litz, Katherine S; Thornhill, Monica G; Goreczny, Anthony J

    2016-01-01

    More individuals with an intellectual disability now possess prerequisite skills and supports necessary for successful work force integration than did previous generations. The current study compared quality of life of community-integrated workers with those participating in sheltered vocational workshops and adult day care programs. We considered numerous indices of quality of life, including inclusion and community participation; satisfaction within professional services, home life, and day activities; dignity, rights, and respect received from others; fear; choice and control; and family satisfaction. Our data revealed several important differences in quality of life across daytime activities; participants involved in community-integrated employment tended to be younger, indicated a greater sense of community integration, and reported more financial autonomy than did those who participated in adult day care programs and sheltered workshops. However, individuals reported no differences in overall satisfaction across daytime activities. We discuss generational differences across employment status as well as possible explanations to account for high levels of satisfaction across daytime activities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Matter Tracking Information System -

    Data.gov (United States)

    Department of Transportation — The Matter Tracking Information System (MTIS) principle function is to streamline and integrate the workload and work activity generated or addressed by our 300 plus...

  14. Right-to-left shunt may be prone to affect the white matter integrity of posterior circulation in migraine without aura.

    Science.gov (United States)

    Xie, Hui; Bian, Yitong; Jian, Zhijie; Huo, Kang; Liu, Rui; Zhu, Dan; Zhang, Lihui; Wu, Jun; Yang, Jian; Liu, Jixin; Luo, Guogang

    2018-01-01

    Numerous studies have indicated an association between migraine and right-to-left shunt. However, little is known about whether right-to-left shunt has an effect on the migraine brain. This observational study aims to explore the impact of right-to-left shunt on the brain of migraine without aura on microstructural level. Thirty-five patients with migraine without aura were enrolled in this study. Contrast-enhanced Transcranial Doppler was performed to evaluate the status of right-to-left shunt. Three-dimensional T1-weighted and diffusion tensor images were acquired for data analysis. We employed voxel-based morphometry and tract-based spatial statistical analyses to assess the differences of gray and white matter between migraineurs with and without right-to-left shunt, respectively. Among the 35 patients, 19 (54.3%) patients had right-to-left shunt. There were no significant differences in headache features between migraineurs with and without right-to-left shunt. There were significant increases of mean and radial diffusivity in migraineurs with right-to-left shunt compared with migraineurs without right-to-left shunt. The alterations were primarily located in the right posterior thalamic radiation, secondly in the body of corpus callosum and the right superior corona radiata. No significant differences were observed in values of fractional anisotropy and axial diffusivity. No significant between-group differences were found in gray matter volume. Right-to-left shunt may cause alterations of white matter integrity in migraine without aura, and the alterations are more likely to be located at the posterior circulation.

  15. [Integrity].

    Science.gov (United States)

    Gómez Rodríguez, Rafael Ángel

    2014-01-01

    To say that someone possesses integrity is to claim that that person is almost predictable about responses to specific situations, that he or she can prudentially judge and to act correctly. There is a closed interrelationship between integrity and autonomy, and the autonomy rests on the deeper moral claim of all humans to integrity of the person. Integrity has two senses of significance for medical ethic: one sense refers to the integrity of the person in the bodily, psychosocial and intellectual elements; and in the second sense, the integrity is the virtue. Another facet of integrity of the person is la integrity of values we cherish and espouse. The physician must be a person of integrity if the integrity of the patient is to be safeguarded. The autonomy has reduced the violations in the past, but the character and virtues of the physician are the ultimate safeguard of autonomy of patient. A field very important in medicine is the scientific research. It is the character of the investigator that determines the moral quality of research. The problem arises when legitimate self-interests are replaced by selfish, particularly when human subjects are involved. The final safeguard of moral quality of research is the character and conscience of the investigator. Teaching must be relevant in the scientific field, but the most effective way to teach virtue ethics is through the example of the a respected scientist.

  16. The salience network and human personality: Integrity of white matter tracts within anterior and posterior salience network relates to the self-directedness character trait.

    Science.gov (United States)

    Prillwitz, Conrad; Rüber, Theodor; Reuter, Martin; Montag, Christian; Weber, Bernd; Elger, Christian E; Markett, Sebastian

    2018-04-28

    A prevailing topic in personality neuroscience is the question how personality traits are reflected in the brain. Functional and structural networks have been examined by functional and structural magnetic resonance imaging, however, the structural correlates of functionally defined networks have not been investigated in a personality context. By using the Temperament and Character Inventory (TCI) and Diffusion Tensor Imaging (DTI), the present study assesses in a sample of 116 healthy participants how personality traits proposed in the framework of the biopsychosocial theory on personality relate to white matter pathways delineated by functional network imaging. We show that the character trait self-directedness relates to the overall microstructural integrity of white matter tracts constituting the salience network as indicated by DTI-derived measures. Self-directedness has been proposed as the executive control component of personality and describes the tendency to stay focused on the attainment of long-term goals. The present finding corroborates the view of the salience network as an executive control network that serves maintenance of rules and task-sets to guide ongoing behavior. Copyright © 2018. Published by Elsevier B.V.

  17. Estimating pesticide sampling rates by the polar organic chemical integrative sampler (POCIS) in the presence of natural organic matter and varying hydrodynamic conditions

    Science.gov (United States)

    Charlestra, Lucner; Amirbahman, Aria; Courtemanch, David L.; Alvarez, David A.; Patterson, Howard

    2012-01-01

    The polar organic chemical integrative sampler (POCIS) was calibrated to monitor pesticides in water under controlled laboratory conditions. The effect of natural organic matter (NOM) on the sampling rates (Rs) was evaluated in microcosms containing -1 of total organic carbon (TOC). The effect of hydrodynamics was studied by comparing Rs values measured in stirred (SBE) and quiescent (QBE) batch experiments and a flow-through system (FTS). The level of NOM in the water used in these experiments had no effect on the magnitude of the pesticide sampling rates (p > 0.05). However, flow velocity and turbulence significantly increased the sampling rates of the pesticides in the FTS and SBE compared to the QBE (p < 0.001). The calibration data generated can be used to derive pesticide concentrations in water from POCIS deployed in stagnant and turbulent environmental systems without correction for NOM.

  18. Quantifying Matter

    CERN Document Server

    Angelo, Joseph A

    2011-01-01

    Quantifying Matter explains how scientists learned to measure matter and quantify some of its most fascinating and useful properties. It presents many of the most important intellectual achievements and technical developments that led to the scientific interpretation of substance. Complete with full-color photographs, this exciting new volume describes the basic characteristics and properties of matter. Chapters include:. -Exploring the Nature of Matter. -The Origin of Matter. -The Search for Substance. -Quantifying Matter During the Scientific Revolution. -Understanding Matter's Electromagnet

  19. Interprofessional collaboration - a matter of differentiation and integration? Theoretical reflections based in the context of Norwegian childcare.

    Science.gov (United States)

    Willumsen, Elisabeth

    2008-08-01

    This paper presents a selection of theoretical approaches illuminating some aspects of interprofessional collaboration, which will be related to theory of contingency as well as to the concepts of differentiation and integration. Theories that describe collaboration on an interpersonal as well as inter-organizational level are outlined and related to dynamic and contextual factors. Implications for the organization of welfare services are elucidated and a categorization of internal and external collaborative forms is proposed. A reflection model is presented in order to analyse the degree of integration in collaborative work and may serve as an analytical tool for addressing the linkage between different levels of collaboration and identifying opportunities and limitations. Some implications related to the legal mandate(s) given to childcare agencies are discussed in relation to the context of childcare in Norway.

  20. Cue integration vs. exemplar-based reasoning in multi-attribute decisions from memory: A matter of cue representation

    OpenAIRE

    Arndt Broeder; Ben R. Newell; Christine Platzer

    2010-01-01

    Inferences about target variables can be achieved by deliberate integration of probabilistic cues or by retrieving similar cue-patterns (exemplars) from memory. In tasks with cue information presented in on-screen displays, rule-based strategies tend to dominate unless the abstraction of cue-target relations is unfeasible. This dominance has also been demonstrated --- surprisingly --- in experiments that demanded the retrieval of cue values from memory (M. Persson \\& J. Rieskamp, 2009). In th...

  1. Correlation between white matter alterations and cognitive function decline in early Alzheimer's disease

    International Nuclear Information System (INIS)

    Ni Hongyan; Qi Ji; Wang Mingshi

    2008-01-01

    Objective: To investigate the effects of early stage Alzheimer's disease (AD) on white matter (WM) integrity using diffusion tensor imaging (DTI) and its relationship with cognitive function decline. Methods: DTI was performed in 32 subjects, including 14 early AD patients and 18 elder controls (ON) with a 1.5 T MR scanner. Fractional anisotropy (FA) and mean diffusivity (b) values were computed and compared for 9 regions of interest (ROI). Eight standard neuropsychological tests were performed and compared between AD and ON to evaluate basic cognitive capacities of AD. Correlation analysis was applied between FA, D values and scores of neuropsychological tests for all subjects. Results: FA significantly decreased in splenium of the corpus callosum and the posterior parietal-temporal region (S2), and (D)-bar significantly increased in the splenium in AD patients (P<0.05). AD patients showed lower scores compared with ON in all neuropsychological tests (P<0.05). FA of the splenium and S2 positively correlated with several tests scores, while D of multiple ROIs negatively correlated with several tests scores (P<0.05). Conclusions: In the early stage of AD, neuropathology has effect not only on cognitive function, but also on white matter structure, and they have strong relationship. AD patients show white matter changes in specific regions, which reflect loss in cortico-cortical connections. (authors)

  2. The structure of teichoic acid from Bacillus subtilis var. niger WM as determined by 13C nuclear-magnetic-resonance spectroscopy

    International Nuclear Information System (INIS)

    De Boer, W.R.; Kruyssen, F.J.; Wouters, J.T.M.; Kruk, C.

    1976-01-01

    The walls of Bacillus subtilis var. niger WM, grown in a Mg 2+ -limited chemostat culture (carbon source glucose, dilution rate = 0.2 h -1 , 37 0 C, pH 7) contained 45% (w/w) teichoic acid, a polymer composed of glycerol, phosphate and glucose in the molar ratio 1.00 : 1.00 : 0.88. Alkaline hydrolysis of this teichoic acid yielded 1-O-β-glucosylglycerol phosphate (together with small amounts of glycerol phosphate), and 13 C nuclear magnetic resonance spectra of this hydrolysis product, and its derivative after alkaline phosphatase treatment, confirmed that the monomeric unit was 1-O-β-glucosylglycerol-3-phosphate. Assignment of the resonances in the spectrum of undegraded teichoic acid revealed that the polymer was a poly[(2,3)glycerol phosphate], glucosidically substituted on C-1 of glycerol with β-glucose. (orig.) [de

  3. Abnormal inter- and intra-hemispheric integration in male paranoid schizophrenia: a graph-theoretical analysis.

    Science.gov (United States)

    Chen, Jianhuai; Yao, Zhijian; Qin, Jiaolong; Yan, Rui; Hua, Lingling; Lu, Qing

    2015-06-25

    The human brain is a complex network of regions that are structurally interconnected by white matter (WM) tracts. Schizophrenia (SZ) can be conceptualized as a disconnection syndrome characterized by widespread disconnections in WM pathways. To assess whether or not anatomical disconnections are associated with disruption of the topological properties of inter- and intra-hemispheric networks in SZ. We acquired the diffusion tensor imaging data from 24 male patients with paranoid SZ during an acute phase of their illness and from 24 healthy age-matched male controls. The brain FA-weighted (fractional anisotropy-weighted) structural networks were constructed and the inter- and intra-hemispheric integration was assessed by estimating the average characteristic path lengths (CPLs) between and within the left and right hemisphere networks. The mean CPLs for all 18 inter-and intra-hemispheric CPLs assessed were longer in the SZ patient group than in the control group, but only some of these differences were significantly different: the CPLs for the overall inter-hemispheric and the left and right intra-hemispheric networks; the CPLs for the interhemisphere subnetworks of the frontal lobes, temporal lobes, and subcortical structures; and the CPL for the intra- frontal subnetwork in the right hemisphere. Among the 24 patients, the CPL of the inter-frontal subnetwork was positively associated with negative symptom severity, but this was the only significant result among 72 assessed correlations, so it may be a statistical artifact. Our findings suggest that the integrity of intra- and inter-hemispheric WM tracts is disrupted in males with paranoid SZ, supporting the brain network disconnection model (i.e., the (')connectivity hypothesis(')) of schizophrenia. Larger studies with less narrowly defined samples of individuals with schizophrenia are needed to confirm these results.

  4. White matter pathology and disconnection in the frontal lobe in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).

    Science.gov (United States)

    Craggs, Lucinda J L; Yamamoto, Yumi; Ihara, Masafumi; Fenwick, Richard; Burke, Matthew; Oakley, Arthur E; Roeber, Sigrun; Duering, Marco; Kretzschmar, Hans; Kalaria, Raj N

    2014-08-01

    Magnetic resonance imaging indicates diffuse white matter (WM) changes are associated with cognitive impairment in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). We examined whether the distribution of axonal abnormalities is related to microvascular pathology in the underlying WM. We used post-mortem brains from CADASIL subjects and similar age cognitively normal controls to examine WM axonal changes, microvascular pathology, and glial reaction in up to 16 different regions extending rostro-caudally through the cerebrum. Using unbiased stereological methods, we estimated length densities of affected axons immunostained with neurofilament antibody SMI32. Standard immunohistochemistry was used to assess amyloid precursor protein immunoreactivity per WM area. To relate WM changes to microvascular pathology, we also determined the sclerotic index (SI) in WM arterioles. The degree of WM pathology consistently scored higher across all brain regions in CADASIL subjects (Pneurones connecting to targets in the subcortical structures. © 2013 The Authors. Neuropathology and Applied Neurobiology published by John Wiley & Sons Ltd on behalf of British Neuropathological Society.

  5. Age and Alzheimer's pathology disrupt default mode network functioning via alterations in white matter microstructure but not hyperintensities.

    Science.gov (United States)

    Brown, Christopher A; Jiang, Yang; Smith, Charles D; Gold, Brian T

    2018-04-19

    The default mode network (DMN) comprises defined brain regions contributing to internally-directed thought processes. Reductions in task-induced deactivation in the DMN have been associated with increasing age and poorer executive task performance, but factors underlying these functional changes remain unclear. We investigated contributions of white matter (WM) microstructure, WM hyperintensities (WMH) and Alzheimer's pathology to age-related alterations in DMN function. Thirty-five cognitively normal older adults and 29 younger adults underwent working memory task fMRI and diffusion tensor imaging. In the older adults, we measured cerebrospinal fluid tau and Aβ 42 (markers of AD pathology), and WMH on FLAIR imaging (marker of cerebrovascular disease). We identified a set of regions showing DMN deactivation and a set of inter-connecting WM tracts (DMN-WM) common to both age groups. There were negative associations between DMN deactivation and task performance in older adults, consistent with previous studies. Decreased DMN deactivation was associated with AD pathology and WM microstructure but not with WMH volume. Mediation analyses showed that WM microstructure mediated declines in DMN deactivation associated with both aging and AD pathology. Together these results suggest that AD pathology may exert a "second-hit" on WM microstructure, over-and-above the effects of age, both contributing to diminished DMN deactivation in older adults. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Evaluation of organic matter removal and electricity generation by using integrated microbial fuel cells for wastewater treatment.

    Science.gov (United States)

    Yamashita, Takahiro; Ishida, Mitsuyoshi; Ogino, Akifumi; Yokoyama, Hiroshi

    2016-01-01

    A floating all-in-one type of microbial fuel cell (Fa-MFC) that allows simple operation and installation in existing wastewater reservoirs for decomposition of organic matter was designed. A prototype cell was constructed by fixing a tubular floater to an assembly composed of a proton-exchange membrane and an air-cathode. To compare anode materials, carbon-cloth anodes or carbon-brush anodes were included in the assembly. The fabricated assemblies were floated in 1-L beakers filled with acetate medium. Both reactors removed acetate at a rate of 133-181 mg/L/d. The Fa-MFC quipped with brush anodes generated a 1.7-fold higher maximum power density (197 mW/m(2)-cathode area) than did that with cloth anodes (119 mW/m(2)-cathode area). To evaluate the performance of the Fa-MFCs on more realistic substrates, artificial wastewater, containing peptone and meat extract, was placed in a 2-L beaker, and the Fa-MFC with brush anodes was floated in the beaker. The Fa-MFC removed the chemical oxygen demand of the wastewater at a rate of 465-1029 mg/L/d, and generated a maximum power density of 152 mW/m(2)-cathode area. When the Fa-MFC was fed with actual livestock wastewater, the biological oxygen demand of the wastewater was removed at a rate of 45-119 mg/L/d, with electricity generation of 95 mW/m(2)-cathode area. Bacteria related to Geobacter sulfurreducens were predominantly detected in the anode biofilm, as deduced from the analysis of the 16S rRNA gene sequence.

  7. Contribution of Regional White Matter Integrity to Visuospatial Construction Accuracy, Organizational Strategy, and Memory for a Complex Figure in Abstinent Alcoholics.

    Science.gov (United States)

    Rosenbloom, Margaret J; Sassoon, Stephanie A; Pfefferbaum, Adolf; Sullivan, Edith V

    2009-12-01

    Visuospatial construction ability as used in drawing complex figures is commonly impaired in chronic alcoholics, but memory for such information can be enhanced by use of a holistic drawing strategy during encoding. We administered the Rey-Osterrieth Complex Figure Test (ROCFT) to 41 alcoholic and 38 control men and women and assessed the contribution of diffusion tensor imaging (DTI) measures of integrity of selected white matter tracts to ROCFT copy accuracy, copy strategy, and recall accuracy. Although alcoholics copied the figure less accurately than controls, a more holistic strategy at copy was associated with better recall in both groups. Greater radial diffusivity, reflecting compromised myelin integrity, in occipital forceps and external capsule was associated with poorer copy accuracy in both groups. Lower FA, reflecting compromised fiber microstructure in the inferior cingulate bundle, which links frontal and medial temporal episodic memory systems, was associated with piecemeal copy strategy and poorer immediate recall in the alcoholics. The correlations were generally modest and should be considered exploratory. To the extent that the inferior cingulate was relatively spared in alcoholics, it may have provided an alternative pathway to the compromised frontal system for successful copy strategy and, by extension, aided recall.

  8. Radiologic differences in white matter maturation between preterm and full-term infants: TBSS study

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ah Young; Jang, Sung Ho; Ahn, Sang Ho; Cho, Hee Kyung; Jo, Hae Min; Son, Su Min [Yeungnam University, Department of Physical Medicine and Rehabilitation, College of Medicine, Taegu (Korea, Republic of); Lee, Eunsil [Yeungnam University, Department of Pediatrics, College of Medicine, Taegu (Korea, Republic of)

    2013-03-15

    Widespread white matter (WM) pathology in preterm children has been proposed. The purpose of this study was to investigate maturational differences of WM between preterm infants with thinning of the corpus callosum and full-term infants. A total of 18 preterm children and 18 full-term children were divided into three subgroups according to the corrected age at the time of diffusion tensor imaging scanning. Tract-based spatial statistics was used for assessing differences in fractional anisotropy (FA) between preterm and full-term children, and between each age-related subgroup in preterm and in full-term children. In the preterm group, FA values of overall WM showed an increase with age. This trend indicates that WM maturation is a gradual occurrence during a child's first 2 years. In the full-term group, most WM structures had reached maturation at around 1 year of age; however, centrum semiovale level showed sustained maturation during the first 2 years. Results of our study demonstrate radiologic maturational differences of WM and provide evidence of the need for therapeutic intervention within 2 years of birth to prevent specific functional impairment and to improve clinical outcome in preterm children. (orig.)

  9. Frontotemporal White Matter in Adolescents with, and at-Risk for, Bipolar Disorder

    Directory of Open Access Journals (Sweden)

    Sonja M. C. de Zwarte

    2014-03-01

    Full Text Available Frontotemporal neural systems are highly implicated in the emotional dysregulation characteristic of bipolar disorder (BD. Convergent genetic, postmortem, behavioral and neuroimaging evidence suggests abnormalities in the development of frontotemporal white matter (WM in the pathophysiology of BD. This review discusses evidence for the involvement of abnormal WM development in BD during adolescence, with a focus on frontotemporal WM. Findings from diffusion tensor imaging (DTI studies in adults and adolescents are reviewed to explore possible progressive WM abnormalities in the disorder. Intra- and interhemispheric frontotemporal abnormalities were reported in adults with BD. Although evidence in children and adolescents with BD to date has been limited, similar intrahemispheric and interhemispheric findings have also been reported. The findings in youths suggest that these abnormalities may represent a trait marker present early in the course of BD. Functional connectivity studies, demonstrating a relationship between WM abnormalities and frontotemporal dysfunction in BD, and DTI studies of vulnerability in first-degree relatives of individuals with BD, are discussed. Together, findings suggest the involvement of abnormal frontotemporal WM development in the pathophysiology of BD and that these abnormalities may be early trait markers of vulnerability; however, more studies are critically needed.

  10. Mild developmental foreign accent syndrome and psychiatric comorbidity: Altered white matter integrity in speech and emotion regulation networks

    Directory of Open Access Journals (Sweden)

    Marcelo L Berthier

    2016-08-01

    Full Text Available Foreign accent syndrome (FAS is a speech disorder that is defined by the emergence of a peculiar manner of articulation and intonation which is perceived as foreign. In most cases of acquired FAS (AFAS the new accent is secondary to small focal lesions involving components of the bilaterally distributed neural network for speech production. In the past few years FAS has also been described in different psychiatric conditions (conversion disorder, bipolar disorder, schizophrenia as well as in developmental disorders (specific language impairment, apraxia of speech. In the present study, two adult males, one with atypical phonetic production and the other one with cluttering, reported having developmental FAS (DFAS since their adolescence. Perceptual analysis by naïve judges could not confirm the presence of foreign accent, possibly due to the mildness of the speech disorder. However, detailed linguistic analysis provided evidence of prosodic and segmental errors previously reported in AFAS cases. Cognitive testing showed reduced communication in activities of daily living and mild deficits related to psychiatric disorders. Psychiatric evaluation revealed long-lasting internalizing disorders (neuroticism, anxiety, obsessive-compulsive disorder, social phobia, depression, alexithymia, hopelessness, and apathy in both subjects. Diffusion tensor imaging (DTI data from each subject with DFAS were compared with data from a group of 21 age- and gender-matched healthy control subjects. Diffusion parameters (MD, AD, and RD in predefined regions of interest showed changes of white matter microstructure in regions previously related with AFAS and psychiatric disorders. In conclusion, the present findings militate against the possibility that these two subjects have FAS of psychogenic origin. Rather, our findings provide evidence that mild DFAS occurring in the context of subtle, yet persistent, developmental speech disorders may be associated with

  11. Effect of the Maximum Dose on White Matter Fiber Bundles Using Longitudinal Diffusion Tensor Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Tong; Chapman, Christopher H. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Tsien, Christina [Department of Radiation Oncology, Washington University at St Louis, St Louis, Missouri (United States); Kim, Michelle; Spratt, Daniel E.; Lawrence, Theodore S. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Cao, Yue, E-mail: yuecao@umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan (United States)

    2016-11-01

    Purpose: Previous efforts to decrease neurocognitive effects of radiation focused on sparing isolated cortical structures. We hypothesize that understanding temporal, spatial, and dosimetric patterns of radiation damage to whole-brain white matter (WM) after partial-brain irradiation might also be important. Therefore, we carried out a study to develop the methodology to assess radiation therapy (RT)–induced damage to whole-brain WM bundles. Methods and Materials: An atlas-based, automated WM tractography analysis was implemented to quantify longitudinal changes in indices of diffusion tensor imaging (DTI) of 22 major WM fibers in 33 patients with predominantly low-grade or benign brain tumors treated by RT. Six DTI scans per patient were performed from before RT to 18 months after RT. The DTI indices and planned doses (maximum and mean doses) were mapped onto profiles of each of 22 WM bundles. A multivariate linear regression was performed to determine the main dose effect as well as the influence of other clinical factors on longitudinal percentage changes in axial diffusivity (AD) and radial diffusivity (RD) from before RT. Results: Among 22 fiber bundles, AD or RD changes in 12 bundles were affected significantly by doses (P<.05), as the effect was progressive over time. In 9 elongated tracts, decreased AD or RD was significantly related to maximum doses received, consistent with a serial structure. In individual bundles, AD changes were up to 11.5% at the maximum dose locations 18 months after RT. The dose effect on WM was greater in older female patients than younger male patients. Conclusions: Our study demonstrates for the first time that the maximum dose to the elongated WM bundles causes post-RT damage in WM. Validation and correlative studies are necessary to determine the ability and impact of sparing these bundles on preserving neurocognitive function after RT.

  12. Diffusion tensor imaging study of early white matter integrity in HIV-infected patients: A tract-based spatial statistics analysis

    Directory of Open Access Journals (Sweden)

    Ruili Li

    2015-12-01

    Conclusion: Multiple cerebral white matter fiber tracts are damaged in HIV-infected patients without cognitive impairment. Quantitative analysis of DTI using TBSS is valuable in evaluating changes of HIV-associated white matter microstructures.

  13. TU-CD-BRB-05: Radiation Damage Signature of White Matter Fiber Bundles Using Diffusion Tensor Imaging (DTI)

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, T; Chapman, C; Lawrence, T; Cao, Y [University of Michigan, Ann Arbor, MI (United States); Tsien, C [Washington University at St. Louis, St. Louis, MO (United States)

    2015-06-15

    Purpose: To develop an automated and scalable approach and identify temporal, spatial and dosimetric patterns of radiation damage of white matter (WM) fibers following partial brain irradiation. Methods: An automated and scalable approach was developed to extract DTI features of 22 major WM fibers from 33 patients with low-grade/benign tumors treated by radiation therapy (RT). DTI scans of the patients were performed pre-RT, 3- and 6-week during RT, and 1, 6 and 18 months after RT. The automated tractography analysis was applied to 198 datasets as: (1) intra-subject registration of longitudinal DTI, (2) spatial normalization of individual-patient DTI to the Johns Hopkins WM Atlas, (3) automatic fiber tracking regulated by the WM Atlas, and (4) segmentation of WM into 22 major tract profiles. Longitudinal percentage changes in fractional anisotropy (FA), and mean, axial and radial diffusivity (MD/AD/RD) of each tract from pre-RT were quantified and correlated to 95%, 90% and 80% percentiles of doses and mean doses received by the tract. Heatmaps were used to identify clusters of significant correlation and reveal temporal, spatial and dosimetric signatures of WM damage. A multivariate linear regression was further carried out to determine influence of clinical factors. Results: Of 22 tracts, AD/MD changes in 12 tracts had significant correlation with doses, especially at 6 and 18 months post-RT, indicating progressive radiation damage after RT. Most interestingly, the DTI-index changes in the elongated tracts were associated with received maximum doses, suggesting a serial-structure behavior; while short association fibers were affected by mean doses, indicating a parallel-structure response. Conclusion: Using an automated DTI-tractography analysis of whole brain WM fibers, we reveal complex radiation damage patterns of WM fibers. Damage in WM fibers that play an important role in the neural network could be associated with late neurocognitive function declines

  14. Convergence and divergence across construction methods for human brain white matter networks: an assessment based on individual differences.

    Science.gov (United States)

    Zhong, Suyu; He, Yong; Gong, Gaolang

    2015-05-01

    Using diffusion MRI, a number of studies have investigated the properties of whole-brain white matter (WM) networks with differing network construction methods (node/edge definition). However, how the construction methods affect individual differences of WM networks and, particularly, if distinct methods can provide convergent or divergent patterns of individual differences remain largely unknown. Here, we applied 10 frequently used methods to construct whole-brain WM networks in a healthy young adult population (57 subjects), which involves two node definitions (low-resolution and high-resolution) and five edge definitions (binary, FA weighted, fiber-density weighted, length-corrected fiber-density weighted, and connectivity-probability weighted). For these WM networks, individual differences were systematically analyzed in three network aspects: (1) a spatial pattern of WM connections, (2) a spatial pattern of nodal efficiency, and (3) network global and local efficiencies. Intriguingly, we found that some of the network construction methods converged in terms of individual difference patterns, but diverged with other methods. Furthermore, the convergence/divergence between methods differed among network properties that were adopted to assess individual differences. Particularly, high-resolution WM networks with differing edge definitions showed convergent individual differences in the spatial pattern of both WM connections and nodal efficiency. For the network global and local efficiencies, low-resolution and high-resolution WM networks for most edge definitions consistently exhibited a highly convergent pattern in individual differences. Finally, the test-retest analysis revealed a decent temporal reproducibility for the patterns of between-method convergence/divergence. Together, the results of the present study demonstrated a measure-dependent effect of network construction methods on the individual difference of WM network properties. © 2015 Wiley

  15. Evaluation of Repair Tension in Arthroscopic Rotator Cuff Repair: Does It Really Matter to the Integrity of the Rotator Cuff?

    Science.gov (United States)

    Kim, Do Hoon; Jang, Young Hoon; Choi, Young Eun; Lee, Hwa-Ryeong; Kim, Sae Hoon

    2016-11-01

    Repair tension of a torn rotator cuff can affect healing after repair. However, a measurement of the actual tension during arthroscopic rotator cuff repair is not feasible. The relationship between repair tension and healing of a rotator cuff repair remains unclear. The purpose of this study was to evaluate the effect of repair tension on healing at the repair site. The hypothesis was that repair tension would be a major factor in determining the anatomic outcome of rotator cuff repair. Cohort study; Level of evidence, 2. Arthroscopic rotator cuff repairs (132 patients) for full-thickness rotator cuff tears were analyzed. An intraoperative model was designed for the estimation of repair tension using a tensiometer. Magnetic resonance imaging (MRI) was performed approximately 1 year (mean [±SD], 12.7 ± 3.2 months) postoperatively for the evaluation of healing at the repair site. Multivariable analysis was performed for tear size, amount of retraction, and fatty degeneration (FD) of rotator cuff muscles. The mean repair tension measured during the arthroscopic procedure was 28.5 ± 23.1 N. There was a statistically significant correlation between tension and tear size (Pearson correlation coefficient [PCC], 0.529; P repair tension also showed a significant inverse correlation with healing at the repair site (SCC, 0.195; P = .025). However, when sex, age, tear size, amount of retraction, tendon quality, and FD of rotator cuff muscles were included for multivariable logistic regression analysis, only FD of the infraspinatus showed an association with the anatomic outcome of repair (Exp(B) = 0.596; P = .010). Our intraoperative model for the estimation of rotator cuff repair tension showed an inverse correlation of repair tension with healing at the repair site, suggesting that complete healing is less likely with high-tension repairs. A significant association was observed on MRI between a high level of FD of the infraspinatus and repaired tendon integrity. © 2016

  16. Altered topological organization of white matter structural networks in patients with neuromyelitis optica.

    Directory of Open Access Journals (Sweden)

    Yaou Liu

    Full Text Available OBJECTIVE: To investigate the topological alterations of the whole-brain white-matter (WM structural networks in patients with neuromyelitis optica (NMO. METHODS: The present study involved 26 NMO patients and 26 age- and sex-matched healthy controls. WM structural connectivity in each participant was imaged with diffusion-weighted MRI and represented in terms of a connectivity matrix using deterministic tractography method. Graph theory-based analyses were then performed for the characterization of brain network properties. A multiple linear regression analysis was performed on each network metric between the NMO and control groups. RESULTS: The NMO patients exhibited abnormal small-world network properties, as indicated by increased normalized characteristic path length, increased normalized clustering and increased small-worldness. Furthermore, largely similar hub distributions of the WM structural networks were observed between NMO patients and healthy controls. However, regional efficiency in several brain areas of NMO patients was significantly reduced, which were mainly distributed in the default-mode, sensorimotor and visual systems. Furthermore, we have observed increased regional efficiency in a few brain regions such as the orbital parts of the superior and middle frontal and fusiform gyri. CONCLUSION: Although the NMO patients in this study had no discernible white matter T2 lesions in the brain, we hypothesize that the disrupted topological organization of WM networks provides additional evidence for subtle, widespread cerebral WM pathology in NMO.

  17. Effects of long-term mindfulness meditation on brain's white matter microstructure and its aging.

    Directory of Open Access Journals (Sweden)

    Davide eLaneri

    2016-01-01

    Full Text Available Although research on the effects of mindfulness meditation (MM is increasing, still very little has been done to address its influence on the white matter (WM of the brain. We hypothesized that the practice of MM might affect the WM microstructure adjacent to five brain regions of interest associated with mindfulness. Diffusion tensor imaging was employed on samples of meditators and non-meditators (n=64 in order to investigate the effects of MM on group difference and aging. Tract-Based Spatial Statistics was used to estimate the fractional anisotrophy of the WM connected to the thalamus, insula, amygdala, hippocampus and anterior cingulate cortex. The subsequent generalized linear model analysis revealed group differences and a group-by-age interaction in all five selected regions. These data provide preliminary indications that the practice of MM might result in WM matter connectivity change and might provide evidence on its ability to help diminish age-related WM degeneration in key regions which participate in processes of mindfulness.

  18. Three-dimensional textural analysis of brain images reveals distributed grey-matter abnormalities in schizophrenia

    Energy Technology Data Exchange (ETDEWEB)

    Ganeshan, Balaji [University of Sussex, Falmer, Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, Brighton (United Kingdom); University of Sussex, Falmer, Department of Engineering and Design, Brighton (United Kingdom); Miles, Kenneth A.; Critchley, Hugo D. [University of Sussex, Falmer, Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, Brighton (United Kingdom); Young, Rupert C.D.; Chatwin, Christopher R. [University of Sussex, Falmer, Department of Engineering and Design, Brighton (United Kingdom); Gurling, Hugh M.D. [University College London, Department of Mental Health Sciences, London (United Kingdom)

    2010-04-15

    Three-dimensional (3-D) selective- and relative-scale texture analysis (TA) was applied to structural magnetic resonance (MR) brain images to quantify the presence of grey-matter (GM) and white-matter (WM) textural abnormalities associated with schizophrenia. Brain TA comprised volume filtration using the Laplacian of Gaussian filter to highlight fine, medium and coarse textures within GM and WM, followed by texture quantification. Relative TA (e.g. ratio of fine to medium) was also computed. T1-weighted MR whole-brain images from 32 participants with diagnosis of schizophrenia (n = 10) and healthy controls (n = 22) were examined. Five patients possessed marker alleles (SZ8) associated with schizophrenia on chromosome 8 in the pericentriolar material 1 gene while the remaining five had not inherited any of the alleles (SZ0). Filtered fine GM texture (mean grey-level intensity; MGI) most significantly differentiated schizophrenic patients from controls (P = 0.0058; area under the receiver-operating characteristic curve = 0.809, sensitivity = 90%, specificity = 70%). WM measurements did not distinguish the two groups. Filtered GM and WM textures (MGI) correlated with total GM and WM volume respectively. Medium-to-coarse GM entropy distinguished SZ0 from controls (P = 0.0069) while measures from SZ8 were intermediate between the two. 3-D TA of brain MR enables detection of subtle distributed morphological features associated with schizophrenia, determined partly by susceptibility genes. (orig.)

  19. Three-dimensional textural analysis of brain images reveals distributed grey-matter abnormalities in schizophrenia

    International Nuclear Information System (INIS)

    Ganeshan, Balaji; Miles, Kenneth A.; Critchley, Hugo D.; Young, Rupert C.D.; Chatwin, Christopher R.; Gurling, Hugh M.D.

    2010-01-01

    Three-dimensional (3-D) selective- and relative-scale texture analysis (TA) was applied to structural magnetic resonance (MR) brain images to quantify the presence of grey-matter (GM) and white-matter (WM) textural abnormalities associated with schizophrenia. Brain TA comprised volume filtration using the Laplacian of Gaussian filter to highlight fine, medium and coarse textures within GM and WM, followed by texture quantification. Relative TA (e.g. ratio of fine to medium) was also computed. T1-weighted MR whole-brain images from 32 participants with diagnosis of schizophrenia (n = 10) and healthy controls (n = 22) were examined. Five patients possessed marker alleles (SZ8) associated with schizophrenia on chromosome 8 in the pericentriolar material 1 gene while the remaining five had not inherited any of the alleles (SZ0). Filtered fine GM texture (mean grey-level intensity; MGI) most significantly differentiated schizophrenic patients from controls (P = 0.0058; area under the receiver-operating characteristic curve = 0.809, sensitivity = 90%, specificity = 70%). WM measurements did not distinguish the two groups. Filtered GM and WM textures (MGI) correlated with total GM and WM volume respectively. Medium-to-coarse GM entropy distinguished SZ0 from controls (P = 0.0069) while measures from SZ8 were intermediate between the two. 3-D TA of brain MR enables detection of subtle distributed morphological features associated with schizophrenia, determined partly by susceptibility genes. (orig.)

  20. Fully automatic detection of deep white matter T1 hypointense lesions in multiple sclerosis

    Science.gov (United States)

    Spies, Lothar; Tewes, Anja; Suppa, Per; Opfer, Roland; Buchert, Ralph; Winkler, Gerhard; Raji, Alaleh

    2013-12-01

    A novel method is presented for fully automatic detection of candidate white matter (WM) T1 hypointense lesions in three-dimensional high-resolution T1-weighted magnetic resonance (MR) images. By definition, T1 hypointense lesions have similar intensity as gray matter (GM) and thus appear darker than surrounding normal WM in T1-weighted images. The novel method uses a standard classification algorithm to partition T1-weighted images into GM, WM and cerebrospinal fluid (CSF). As a consequence, T1 hypointense lesions are assigned an increased GM probability by the standard classification algorithm. The GM component image of a patient is then tested voxel-by-voxel against GM component images of a normative database of healthy individuals. Clusters (≥0.1 ml) of significantly increased GM density within a predefined mask of deep WM are defined as lesions. The performance of the algorithm was assessed on voxel level by a simulation study. A maximum dice similarity coefficient of 60% was found for a typical T1 lesion pattern with contrasts ranging from WM to cortical GM, indicating substantial agreement between ground truth and automatic detection. Retrospective application to 10 patients with multiple sclerosis demonstrated that 93 out of 96 T1 hypointense lesions were detected. On average 3.6 false positive T1 hypointense lesions per patient were found. The novel method is promising to support the detection of hypointense lesions in T1-weighted images which warrants further evaluation in larger patient samples.

  1. Activation of auditory white matter tracts as revealed by functional magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tae, Woo Suk [Kangwon National University, Neuroscience Research Institute, School of Medicine, Chuncheon (Korea, Republic of); Yakunina, Natalia; Nam, Eui-Cheol [Kangwon National University, Neuroscience Research Institute, School of Medicine, Chuncheon (Korea, Republic of); Kangwon National University, Department of Otolaryngology, School of Medicine, Chuncheon, Kangwon-do (Korea, Republic of); Kim, Tae Su [Kangwon National University Hospital, Department of Otolaryngology, Chuncheon (Korea, Republic of); Kim, Sam Soo [Kangwon National University, Neuroscience Research Institute, School of Medicine, Chuncheon (Korea, Republic of); Kangwon National University, Department of Radiology, School of Medicine, Chuncheon (Korea, Republic of)

    2014-07-15

    The ability of functional magnetic resonance imaging (fMRI) to detect activation in brain white matter (WM) is controversial. In particular, studies on the functional activation of WM tracts in the central auditory system are scarce. We utilized fMRI to assess and characterize the entire auditory WM pathway under robust experimental conditions involving the acquisition of a large number of functional volumes, the application of broadband auditory stimuli of high intensity, and the use of sparse temporal sampling to avoid scanner noise effects and increase signal-to-noise ratio. Nineteen healthy volunteers were subjected to broadband white noise in a block paradigm; each run had four sound-on/off alternations and was repeated nine times for each subject. Sparse sampling (TR = 8 s) was used. In addition to traditional gray matter (GM) auditory center activation, WM activation was detected in the isthmus and midbody of the corpus callosum (CC), tapetum, auditory radiation, lateral lemniscus, and decussation of the superior cerebellar peduncles. At the individual level, 13 of 19 subjects (68 %) had CC activation. Callosal WM exhibited a temporal delay of approximately 8 s in response to the stimulation compared with GM. These findings suggest that direct evaluation of the entire functional network of the central auditory system may be possible using fMRI, which may aid in understanding the neurophysiological basis of the central auditory system and in developing treatment strategies for various central auditory disorders. (orig.)

  2. Quantitative evaluation of cerebral white matter in patients with multiple sclerosis using multicomponent T2 mapping.

    Science.gov (United States)

    Baranovicova, Eva; Mlynarik, Vladimir; Kantorova, Ema; Hnilicova, Petra; Dobrota, Dusan

    2016-05-01

    A standard magnetic resonance imaging (MRI) investigation of white matter (WM) areas with visible or expected pathology does not explain satisfactorily the relation between pathology and clinical outcome. Therefore, we focused on multicomponent T2 mapping of WM with the intention to characterize the WM, including normal-appearing white matter that has normal and prolonged T2 and lesions, including degenerated tissue. Twenty-nine patients with clinically diagnosed MS and 27 healthy controls underwent MRI examination. T2 mapping of the WM across the two whole MRI slices was carried out. The relative abundance of biologically relevant T2 regions was correlated with age and the expanded disability status scale (EDSS). The relative abundance of the T2 values of water trapped in myelin increased with age in both healthy subjects (p T2 assigned to intra- and extracellular water decreased with age in both groups (p T2 above 110 ms were not related to age, but strongly increased with EDSS (p T2 mapping of the WM can be a useful parameter for monitoring the progression of MS in patients.

  3. Activation of auditory white matter tracts as revealed by functional magnetic resonance imaging

    International Nuclear Information System (INIS)

    Tae, Woo Suk; Yakunina, Natalia; Nam, Eui-Cheol; Kim, Tae Su; Kim, Sam Soo

    2014-01-01

    The ability of functional magnetic resonance imaging (fMRI) to detect activation in brain white matter (WM) is controversial. In particular, studies on the functional activation of WM tracts in the central auditory system are scarce. We utilized fMRI to assess and characterize the entire auditory WM pathway under robust experimental conditions involving the acquisition of a large number of functional volumes, the application of broadband auditory stimuli of high intensity, and the use of sparse temporal sampling to avoid scanner noise effects and increase signal-to-noise ratio. Nineteen healthy volunteers were subjected to broadband white noise in a block paradigm; each run had four sound-on/off alternations and was repeated nine times for each subject. Sparse sampling (TR = 8 s) was used. In addition to traditional gray matter (GM) auditory center activation, WM activation was detected in the isthmus and midbody of the corpus callosum (CC), tapetum, auditory radiation, lateral lemniscus, and decussation of the superior cerebellar peduncles. At the individual level, 13 of 19 subjects (68 %) had CC activation. Callosal WM exhibited a temporal delay of approximately 8 s in response to the stimulation compared with GM. These findings suggest that direct evaluation of the entire functional network of the central auditory system may be possible using fMRI, which may aid in understanding the neurophysiological basis of the central auditory system and in developing treatment strategies for various central auditory disorders. (orig.)

  4. The role of gray and white matter segmentation in quantitative proton MR spectroscopic imaging.

    Science.gov (United States)

    Tal, Assaf; Kirov, Ivan I; Grossman, Robert I; Gonen, Oded

    2012-12-01

    Since the brain's gray matter (GM) and white matter (WM) metabolite concentrations differ, their partial volumes can vary the voxel's ¹H MR spectroscopy (¹H-MRS) signal, reducing sensitivity to changes. While single-voxel ¹H-MRS cannot differentiate between WM and GM signals, partial volume correction is feasible by MR spectroscopic imaging (MRSI) using segmentation of the MRI acquired for VOI placement. To determine the magnitude of this effect on metabolic quantification, we segmented a 1-mm³ resolution MRI into GM, WM and CSF masks that were co-registered with the MRSI grid to yield their partial volumes in approximately every 1 cm³ spectroscopic voxel. Each voxel then provided one equation with two unknowns: its i- metabolite's GM and WM concentrations C(i) (GM) , C(i) (WM) . With the voxels' GM and WM volumes as independent coefficients, the over-determined system of equations was solved for the global averaged C(i) (GM) and C(i) (WM) . Trading off local concentration differences offers three advantages: (i) higher sensitivity due to combined data from many voxels; (ii) improved specificity to WM versus GM changes; and (iii) reduced susceptibility to partial volume effects. These improvements made no additional demands on the protocol, measurement time or hardware. Applying this approach to 18 volunteered 3D MRSI sets of 480 voxels each yielded N-acetylaspartate, creatine, choline and myo-inositol C(i) (GM) concentrations of 8.5 ± 0.7, 6.9 ± 0.6, 1.2 ± 0.2, 5.3 ± 0.6 mM, respectively, and C(i) (WM) concentrations of 7.7 ± 0.6, 4.9 ± 0.5, 1.4 ± 0.1 and 4.4 ± 0.6mM, respectively. We showed that unaccounted voxel WM or GM partial volume can vary absolute quantification by 5-10% (more for ratios), which can often double the sample size required to establish statistical significance. Copyright © 2012 John Wiley & Sons, Ltd.

  5. Clinical prediction of fall risk and white matter abnormalities: a diffusion tensor imaging study

    Science.gov (United States)

    The Tinetti scale is a simple clinical tool designed to predict risk of falling by focusing on gait and stance impairment in elderly persons. Gait impairment is also associated with white matter (WM) abnormalities. Objective: To test the hypothesis that elderly subjects at risk for falling, as deter...

  6. Dark Matter

    Directory of Open Access Journals (Sweden)

    Einasto J.

    2011-06-01

    Full Text Available I give a review of the development of the concept of dark matter. The dark matter story passed through several stages from a minor observational puzzle to a major challenge for theory of elementary particles. Modern data suggest that dark matter is the dominant matter component in the Universe, and that it consists of some unknown non-baryonic particles. Dark matter is the dominant matter component in the Universe, thus properties of dark matter particles determine the structure of the cosmic web.

  7. Clinical Study White Matter Atrophy in Patients with Mesial Temporal Lobe Epilepsy: Voxel-Based Morphometry Analysis of T1- and T2-Weighted MR Images

    International Nuclear Information System (INIS)

    Braga, B.; Yasuda, C.L.; Cendes, F.

    2012-01-01

    Introduction. Mesial temporal lobe epilepsy (MTLE) associated with hippocampal sclerosis is highly refractory to clinical treatment. MRI voxel-based morphometry (VBM) of T1-weighted images has revealed a widespread pattern of gray matter (GM) and white matter (WM) atrophy in MTLE. Few studies have investigated the role of T2-weighted images in revealing WM atrophy using VBM. Objectives. To compare the results of WM atrophy between T1- and T2-weighted images through VBM. Methods. We selected 28 patients with left and 27 with right MTLE and 60 normal controls. We analyzed T1- and T2- weighted images with SPM8, using VBM/DARTEL algorithm to extract maps of GM and WM. The second level of SPM was used to investigate areas of WM atrophy among groups. Results. Both acquisitions showed bilateral widespread WM atrophy. T1-weighted images showed higher sensibility to detect areas of WM atrophy in both groups of MTLE. T2-weighted images also showed areas of WM atrophy in a more restricted pattern, but still bilateral and with a large area of superposition with T1-weighted images. Conclusions. In MTLE, T1-weighted images are more sensitive to detect subtle WM abnormalities using VBM, compared to T2 images, although both present a good superposition of statistical maps. 1. Introduction The mesial temporal lobe epilepsy (MTLE) is highly refractory to pharmacological treatment [1], and it is the main group of epilepsy referred to the tertiary care hospitals for surgical treatment [2]. MTLE shows a good surgical prognosis, with satisfactory seizures control in 60-80% of the patients [3]. In approximately 65%

  8. 40 CFR Appendix L to Part 50 - Reference Method for the Determination of Fine Particulate Matter as PM2.5 in the Atmosphere

    Science.gov (United States)

    2010-07-01

    ... and 1000 W/m2 solar radiation intensity. 7.4.8.2 The ambient temperature sensor shall be of such a... measurement of the mass concentration of fine particulate matter having an aerodynamic diameter less than or... matter specified in § 50.7 and § 50.13 of this part are met. The measurement process is considered to be...

  9. Estimating pesticide sampling rates by the polar organic chemical integrative sampler (POCIS) in the presence of natural organic matter and varying hydrodynamic conditions

    International Nuclear Information System (INIS)

    Charlestra, Lucner; Amirbahman, Aria; Courtemanch, David L.; Alvarez, David A.; Patterson, Howard

    2012-01-01

    The polar organic chemical integrative sampler (POCIS) was calibrated to monitor pesticides in water under controlled laboratory conditions. The effect of natural organic matter (NOM) on the sampling rates (R s ) was evaluated in microcosms containing −1 of total organic carbon (TOC). The effect of hydrodynamics was studied by comparing R s values measured in stirred (SBE) and quiescent (QBE) batch experiments and a flow-through system (FTS). The level of NOM in the water used in these experiments had no effect on the magnitude of the pesticide sampling rates (p > 0.05). However, flow velocity and turbulence significantly increased the sampling rates of the pesticides in the FTS and SBE compared to the QBE (p < 0.001). The calibration data generated can be used to derive pesticide concentrations in water from POCIS deployed in stagnant and turbulent environmental systems without correction for NOM. - Highlights: ► We assessed the effect of TOC and stirring on pesticide sampling rates by POCIS. ► Total organic carbon (TOC) had no effect on the sampling rates. ► Water flow and stirring significantly increased the magnitude of the sampling rates. ► The sampling rates generated are directly applicable to field conditions. - This study provides POCIS sampling rates data that can be used to estimate freely dissolved concentrations of toxic pesticides in natural waters.

  10. Early post-natal exposure to intermittent hypoxia in rodents is pro-inflammatory, impairs white matter integrity and alters brain metabolism

    Science.gov (United States)

    Darnall, Robert A.; Chen, Xi; Nemani, Krishnamurthy V.; Sirieix, Chrystelle M.; Gimi, Barjor; Knoblach, Susan; McEntire, Betty L.; Hunt, Carl E.

    2017-01-01

    Background Preterm infants are frequently exposed to intermittent hypoxia (IH) associated with apnea and periodic breathing that may result in inflammation and brain injury that later manifests as cognitive and executive function deficits. We used a rodent model to determine whether early postnatal exposure to IH would result in inflammation and brain injury. Methods Rat pups were exposed to IH from P2–P12. Control animals were exposed to room air. Cytokines were analyzed in plasma and brain tissue at P13 and P18. At P20–P22, diffusion tensor imaging (DTI) and magnetic resonance spectroscopy (MRS) were performed. Results Pups exposed to IH had increased plasma Gro/CXCL1 and cerebellar IFN-γ and IL-1β at P13, and brainstem enolase at P18. DTI showed a decrease in FA and AD in the corpus callosum (CC) and cingulate gyrus and an increase in RD in the CC. MRS revealed decreases in NAA/Cho, Cr, Tau/Cr and Gly/Cr and increases in TCho and GPC in the brainstem and decreases in NAA/Cho in the hippocampus. Conclusions We conclude that early postnatal exposure to IH, similar in magnitude experienced in human preterm infants, is associated with evidence for pro-inflammatory changes, decreases in white matter integrity, and metabolic changes consistent with hypoxia. PMID:28388601

  11. Alterations in the microstructure of white matter in children and adolescents with Tourette syndrome measured using tract-based spatial statistics and probabilistic tractography.

    Science.gov (United States)

    Sigurdsson, Hilmar P; Pépés, Sophia E; Jackson, Georgina M; Draper, Amelia; Morgan, Paul S; Jackson, Stephen R

    2018-04-12

    Tourette syndrome (TS) is a neurodevelopmental disorder characterised by repetitive and intermittent motor and vocal tics. TS is thought to reflect fronto-striatal dysfunction and the aetiology of the disorder has been linked to widespread alterations in the functional and structural integrity of the brain. The aim of this study was to assess white matter (WM) abnormalities in a large sample of young patients with TS in comparison to a sample of matched typically developing control individuals (CS) using diffusion MRI. The study included 35 patients with TS (3 females; mean age: 14.0 ± 3.3) and 35 CS (3 females; mean age: 13.9 ± 3.3). Diffusion MRI data was analysed using tract-based spatial statistics (TBSS) and probabilistic tractography. Patients with TS demonstrated both marked and widespread decreases in axial diffusivity (AD) together with altered WM connectivity. Moreover, we showed that tic severity and the frequency of premonitory urges (PU) were associated with increased connectivity between primary motor cortex (M1) and the caudate nuclei, and increased information transfer between M1 and the insula, respectively. This is to our knowledge the first study to employ both TBSS and probabilistic tractography in a sample of young patients with TS. Our results contribute to the limited existing literature demonstrating altered connectivity in TS and confirm previous results suggesting in particular, that altered insular function contributes to increased frequency of PU. Copyright © 2018. Published by Elsevier Ltd.

  12. Integration of Distinct Objects in Visual Working Memory Depends on Strong Objecthood Cues Even for Different-Dimension Conjunctions.

    Science.gov (United States)

    Balaban, Halely; Luria, Roy

    2016-05-01

    What makes an integrated object in visual working memory (WM)? Past evidence suggested that WM holds all features of multidimensional objects together, but struggles to integrate color-color conjunctions. This difficulty was previously attributed to a challenge in same-dimension integration, but here we argue that it arises from the integration of 2 distinct objects. To test this, we examined the integration of distinct different-dimension features (a colored square and a tilted bar). We monitored the contralateral delay activity, an event-related potential component sensitive to the number of objects in WM. The results indicated that color and orientation belonging to distinct objects in a shared location were not integrated in WM (Experiment 1), even following a common fate Gestalt cue (Experiment 2). These conjunctions were better integrated in a less demanding task (Experiment 3), and in the original WM task, but with a less individuating version of the original stimuli (Experiment 4). Our results identify the critical factor in WM integration at same- versus separate-objects, rather than at same- versus different-dimensions. Compared with the perfect integration of an object's features, the integration of several objects is demanding, and depends on an interaction between the grouping cues and task demands, among other factors. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  13. Soft Active Matter

    OpenAIRE

    Marchetti, M. C.; Joanny, J. -F.; Ramaswamy, S.; Liverpool, T. B.; Prost, J.; Rao, Madan; Simha, R. Aditi

    2012-01-01

    In this review we summarize theoretical progress in the field of active matter, placing it in the context of recent experiments. Our approach offers a unified framework for the mechanical and statistical properties of living matter: biofilaments and molecular motors in vitro or in vivo, collections of motile microorganisms, animal flocks, and chemical or mechanical imitations. A major goal of the review is to integrate the several approaches proposed in the literature, from semi-microscopic t...

  14. Solid Matter

    CERN Document Server

    Angelo, Joseph A

    2011-01-01

    Supported by a generous quantity of full-color illustrations and interesting sidebars, Solid Matter introduces the basic characteristics and properties of solid matter. It briefly describes the cosmic connection of the elements, leading readers through several key events in human pre-history that resulted in more advanced uses of matter in the solid state. Chapters include:. -Solid Matter: An Initial Perspective. -Physical Behavior of Matter. -The Gravity of Matter. -Fundamentals of Materials Science. -Rocks and Minerals. -Metals. -Building Materials. -Carbon Earth's Most Versatile Element. -S

  15. 'Integration'

    DEFF Research Database (Denmark)

    Olwig, Karen Fog

    2011-01-01

    , while the countries have adopted disparate policies and ideologies, differences in the actual treatment and attitudes towards immigrants and refugees in everyday life are less clear, due to parallel integration programmes based on strong similarities in the welfare systems and in cultural notions...... of equality in the three societies. Finally, it shows that family relations play a central role in immigrants’ and refugees’ establishment of a new life in the receiving societies, even though the welfare society takes on many of the social and economic functions of the family....

  16. Speech Matters

    DEFF Research Database (Denmark)

    Hasse Jørgensen, Stina

    2011-01-01

    About Speech Matters - Katarina Gregos, the Greek curator's exhibition at the Danish Pavillion, the Venice Biannual 2011.......About Speech Matters - Katarina Gregos, the Greek curator's exhibition at the Danish Pavillion, the Venice Biannual 2011....

  17. Memory Matters

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Memory Matters KidsHealth / For Kids / Memory Matters What's in ... of your complex and multitalented brain. What Is Memory? When an event happens, when you learn something, ...

  18. Cloning, expression, purification, crystallization and preliminary X-ray analysis of NodS N-methyltransferase from Bradyrhizobium japonicum WM9

    International Nuclear Information System (INIS)

    Cakici, Ozgur; Sikorski, Michal; Stepkowski, Tomasz; Bujacz, Grzegorz; Jaskolski, Mariusz

    2008-01-01

    The NodS N-methyltransferase, an enzyme participating in the biosynthesis of the bacterial nodulation (Nod) factor necessary to establish symbiotic nitrogen fixation with a legume plant host, has been crystallized in the apo form as well as in complex with SAH. SAH is a byproduct of SAM degradation during the SAM-dependent methylation reaction. The Nod factor (NF) is a rhizobial signal molecule that is involved in recognition of a legume host and the formation of root and stem nodules. Some unique enzymes are involved in the biosynthesis of NF, which is a variously but specifically substituted lipochitooligosaccharide. One of these enzymes is NodS, an N-methyltransferase that methylates end-deacetylated chitooligosaccharide substrates. In the methylation reaction, NodS uses S-adenosyl-l-methionine (SAM) as a methyl donor. To date, no structural information is available about NodS from any rhizobium. X-ray crystallographic studies of the NodS protein from Bradyrhizobium japonicum WM9, which infects the legumes lupin and serradella, have been undertaken. The nodS gene was cloned and the recombinant protein was expressed in Escherichia coli cells using natural amino acids and as an SeMet derivative. NodS without ligands was crystallized in the presence of PEG 3350 and MgCl 2 . The protein was also crystallized in complex with S-adenosyl-l-homocysteine (SAH) in the presence of PEG 8000 and MgCl 2 . SAH is produced from SAM as a byproduct of the methylation reaction. The crystals of apo NodS are tetragonal and diffracted X-rays to 2.42 Å resolution. The NodS–SAH complex crystallizes in an orthorhombic space group and the crystals diffracted X-rays to 1.85 Å resolution

  19. Multi-parameter observations in the Ibero-Moghrebian region: the Western Mediterranean seismic network (WM) and ROA GPS geodynamic network

    Science.gov (United States)

    Pazos, Antonio; Martín Davila, José; Buforn, Elisa; Gárate Pasquín, Jorge; Catalán Morollón, Manuel; Hanka, Winfried; Udías, Agustín.; Benzzeghoud, Mourad; Harnafi, Mimoun

    2010-05-01

    The plate boundary between Eurasia and Africa plates crosses the called "Ibero-Maghrebian" region from the San Vicente Cape (SW Portugal) to Tunisia including the South of Iberia, Alboran Sea, and northern Morocco and Algeria. In this area, the convergence, with a low rate, is accommodated over a wide and diffuse deformation zone, characterized by a significant and widespread moderate seismic activity [Buforn et al., 1995], and the occurrence of large earthquakes is separated by long time intervals. Since more than hundred years ago San Fernando Naval Observatory (ROA), in collaboration with other Institutes, has deployed different geophysical and geodetic equipment in the Southern Spain - North-western Africa area in order to study this broad deformation zone. Currently a Broad Band seismic net (Western Mediterranean, WM net) is deployed, in collaboration with other institutions, around the Gulf of Cádiz and the Alboran sea, with stations in the South of Iberia and in North Africa (at Spanish places and Morocco), together with the seismic stations a permanent geodetic GPS net is co-installed at the same sites. Also, other geophysical instruments have been installed: a Satellite Laser Ranging (SLR) station at San Fernando Observatory Headquarter, a Geomagnetic Observatory in Cádiz bay area and some meteorological stations. These networks have been recently improved with the deployment of a new submarine and on-land geophysical observatory in the Alboran island (ALBO Observatory), where a permanent GPS, a meteorological station were installed on land and a permanent submarine observatory in 50 meters depth was also deploy in last October (with a broad band seismic sensor, a 3 C accelerometer and a DPG). This work shows the present status and the future plans of these networks and some results.

  20. Dark Matter

    Indian Academy of Sciences (India)

    What You See Ain't What. You Got, Resonance, Vol.4,. No.9,1999. Dark Matter. 2. Dark Matter in the Universe. Bikram Phookun and Biman Nath. In Part 11 of this article we learnt that there are compelling evidences from dynamics of spiral galaxies, like our own, that there must be non-luminous matter in them. In this.

  1. Longitudinal diffusion tensor magnetic resonance imaging study of radiation-induced white matter damage in a rat model.

    Science.gov (United States)

    Wang, Silun; Wu, Ed X; Qiu, Deqiang; Leung, Lucullus H T; Lau, Ho-Fai; Khong, Pek-Lan

    2009-02-01

    Radiation-induced white matter (WM) damage is a major side effect of whole brain irradiation among childhood cancer survivors. We evaluate longitudinally the diffusion characteristics of the late radiation-induced WM damage in a rat model after 25 and 30 Gy irradiation to the hemibrain at 8 time points from 2 to 48 weeks postradiation. We hypothesize that diffusion tensor magnetic resonance imaging (DTI) indices including fractional anisotropy (FA), trace, axial diffusivity (lambda(//)), and radial diffusivity (lambda( perpendicular)) can accurately detect and monitor the histopathologic changes of radiation-induced WM damage, measured at the EC, and that these changes are dose and time dependent. Results showed a progressive reduction of FA, which was driven by reduction in lambda(//) from 4 to 40 weeks postradiation, and an increase in lambda( perpendicular) with return to baseline in lambda(//) at 48 weeks postradiation. Histologic evaluation of irradiated WM showed reactive astrogliosis from 4 weeks postradiation with reversal at 36 weeks, and demyelination, axonal degeneration, and necrosis at 48 weeks postradiation. Moreover, changes in lambda(//) correlated with reactive astrogliosis (P histopathologic changes of WM damage and our results support the use of DTI as a biomarker to noninvasively monitor radiation-induced WM damage.

  2. Deficits in Docosahexaenoic Acid Accrual during Adolescence Reduce Rat Forebrain White Matter Microstructural Integrity: An in vivo Diffusion Tensor Imaging Study.

    Science.gov (United States)

    McNamara, Robert K; Schurdak, Jennifer D; Asch, Ruth H; Peters, Bart D; Lindquist, Diana M

    2018-01-01

    Neuropsychiatric disorders that frequently initially emerge during adolescence are associated with deficits in the omega-3 (n-3) fatty acid docosahexaenoic acid (DHA), elevated proinflammatory signaling, and regional reductions in white matter integrity (WMI). This study determined the effects of altering brain DHA accrual during adolescence on WMI in the rat brain by diffusion tensor imaging (DTI), and investigated the potential mediating role of proinflammatory signaling. During periadolescent development, male rats were fed a diet deficient in n-3 fatty acids (DEF, n = 20), a fish oil-fortified diet containing preformed DHA (FO, n = 20), or a control diet (CON, n = 20). In adulthood, DTI scans were performed and brain WMI was determined using voxelwise tract-based spatial statistics (TBSS). Postmortem fatty acid composition, peripheral (plasma IL-1β, IL-6, and C-reactive protein [CRP]) and central (IL-1β and CD11b mRNA) proinflammatory markers, and myelin basic protein (MBP) mRNA expression were determined. Compared with CON rats, forebrain DHA levels were lower in DEF rats and higher in FO rats. Compared with CON rats, DEF rats exhibited greater radial diffusivity (RD) and mean diffusivity in the right external capsule, and greater axial diffusivity in the corpus callosum genu and left external capsule. DEF rats also exhibited greater RD than FO rats in the right external capsule. Forebrain MBP expression did not differ between groups. Compared with CON rats, central (IL-1β and CD11b) and peripheral (IL-1β and IL-6) proinflammatory markers were not different in DEF rats, and DEF rats exhibited lower CRP levels. These findings demonstrate that deficits in adolescent DHA accrual negatively impact forebrain WMI, independently of elevated proinflammatory signaling. © 2017 S. Karger AG, Basel.

  3. Persistent, Long-term Cerebral White Matter Changes after Sports-Related Repetitive Head Impacts

    Science.gov (United States)

    Bazarian, Jeffrey J.; Zhu, Tong; Zhong, Jianhui; Janigro, Damir; Rozen, Eric; Roberts, Andrew; Javien, Hannah; Merchant-Borna, Kian; Abar, Beau; Blackman, Eric G.

    2014-01-01

    Introduction Repetitive head impacts (RHI) sustained in contact sports are thought to be necessary for the long-term development of chronic traumatic encephalopathy (CTE). Our objectives were to: 1) characterize the magnitude and persistence of RHI-induced white matter (WM) changes; 2) determine their relationship to kinematic measures of RHI; and 3) explore their clinical relevance. Methods Prospective, observational study of 10 Division III college football players and 5 non-athlete controls during the 2011-12 season. All subjects underwent diffusion tensor imaging (DTI), physiologic, cognitive, and balance testing at pre-season (Time 1), post-season (Time 2), and after 6-months of no-contact rest (Time 3). Head impact measures were recorded using helmet-mounted accelerometers. The percentage of whole-brain WM voxels with significant changes in fractional anisotropy (FA) and mean diffusivity (MD) from Time 1 to 2, and Time 1 to 3 was determined for each subject and correlated to head impacts and clinical measures. Results Total head impacts for the season ranged from 431–1,850. No athlete suffered a clinically evident concussion. Compared to controls, athletes experienced greater changes in FA and MD from Time 1 to 2 as well as Time 1 to 3; most differences at Time 2 persisted to Time 3. Among athletes, the percentage of voxels with decreased FA from Time 1 to 2 was positively correlated with several helmet impact measures. The persistence of WM changes from Time 1 to 3 was also associated with changes in serum ApoA1 and S100B autoantibodies. WM changes were not consistently associated with cognition or balance. Conclusions A single football season of RHIs without clinically-evident concussion resulted in WM changes that correlated with multiple helmet impact measures and persisted following 6 months of no-contact rest. This lack of WM recovery could potentially contribute to cumulative WM changes with subsequent RHI exposures. PMID:24740265

  4. Ascl1 controls the number and distribution of astrocytes and oligodendrocytes in the gray matter and white matter of the spinal cord

    Science.gov (United States)

    Vue, Tou Yia; Kim, Euiseok J.; Parras, Carlos M.; Guillemot, Francois; Johnson, Jane E.

    2014-01-01

    Glia constitute the majority of cells in the mammalian central nervous system and are crucial for neurological function. However, there is an incomplete understanding of the molecular control of glial cell development. We find that the transcription factor Ascl1 (Mash1), which is best known for its role in neurogenesis, also functions in both astrocyte and oligodendrocyte lineages arising in the mouse spinal cord at late embryonic stages. Clonal fate mapping in vivo reveals heterogeneity in Ascl1-expressing glial progenitors and shows that Ascl1 defines cells that are restricted to either gray matter (GM) or white matter (WM) as astrocytes or oligodendrocytes. Conditional deletion of Ascl1 post-neurogenesis shows that Ascl1 is required during oligodendrogenesis for generating the correct numbers of WM but not GM oligodendrocyte precursor cells, whereas during astrocytogenesis Ascl1 functions in balancing the number of dorsal GM protoplasmic astrocytes with dorsal WM fibrous astrocytes. Thus, in addition to its function in neurogenesis, Ascl1 marks glial progenitors and controls the number and distribution of astrocytes and oligodendrocytes in the GM and WM of the spinal cord. PMID:25249462

  5. Combined DTI Tractography and Functional MRI Study of the Language Connectome in Healthy Volunteers: Extensive Mapping of White Matter Fascicles and Cortical Activations.

    Directory of Open Access Journals (Sweden)

    François Vassal

    Full Text Available Despite a better understanding of brain language organization into large-scale cortical networks, the underlying white matter (WM connectivity is still not mastered. Here we combined diffusion tensor imaging (DTI fiber tracking (FT and language functional magnetic resonance imaging (fMRI in twenty healthy subjects to gain new insights into the macroscopic structural connectivity of language. Eight putative WM fascicles for language were probed using a deterministic DTI-FT technique: the arcuate fascicle (AF, superior longitudinal fascicle (SLF, uncinate fascicle (UF, temporo-occipital fascicle, inferior fronto-occipital fascicle (IFOF, middle longitudinal fascicle (MdLF, frontal aslant fascicle and operculopremotor fascicle. Specific measurements (i.e. volume, length, fractional anisotropy and precise cortical terminations were derived for each WM fascicle within both hemispheres. Connections between these WM fascicles and fMRI activations were studied to determine which WM fascicles are related to language. WM fascicle volumes showed asymmetries: leftward for the AF, temporoparietal segment of SLF and UF, and rightward for the frontoparietal segment of the SLF. The lateralization of the AF, IFOF and MdLF extended to differences in patterns of anatomical connections, which may relate to specific hemispheric abilities. The leftward asymmetry of the AF was correlated to the leftward asymmetry of fMRI activations, suggesting that the lateralization of the AF is a structural substrate of hemispheric language dominance. We found consistent connections between fMRI activations and terminations of the eight WM fascicles, providing a detailed description of the language connectome. WM fascicle terminations were also observed beyond fMRI-confirmed language areas and reached numerous cortical areas involved in different functional brain networks. These findings suggest that the reported WM fascicles are not exclusively involved in language and might be

  6. Combined DTI Tractography and Functional MRI Study of the Language Connectome in Healthy Volunteers: Extensive Mapping of White Matter Fascicles and Cortical Activations.

    Science.gov (United States)

    Vassal, François; Schneider, Fabien; Boutet, Claire; Jean, Betty; Sontheimer, Anna; Lemaire, Jean-Jacques

    2016-01-01

    Despite a better understanding of brain language organization into large-scale cortical networks, the underlying white matter (WM) connectivity is still not mastered. Here we combined diffusion tensor imaging (DTI) fiber tracking (FT) and language functional magnetic resonance imaging (fMRI) in twenty healthy subjects to gain new insights into the macroscopic structural connectivity of language. Eight putative WM fascicles for language were probed using a deterministic DTI-FT technique: the arcuate fascicle (AF), superior longitudinal fascicle (SLF), uncinate fascicle (UF), temporo-occipital fascicle, inferior fronto-occipital fascicle (IFOF), middle longitudinal fascicle (MdLF), frontal aslant fascicle and operculopremotor fascicle. Specific measurements (i.e. volume, length, fractional anisotropy) and precise cortical terminations were derived for each WM fascicle within both hemispheres. Connections between these WM fascicles and fMRI activations were studied to determine which WM fascicles are related to language. WM fascicle volumes showed asymmetries: leftward for the AF, temporoparietal segment of SLF and UF, and rightward for the frontoparietal segment of the SLF. The lateralization of the AF, IFOF and MdLF extended to differences in patterns of anatomical connections, which may relate to specific hemispheric abilities. The leftward asymmetry of the AF was correlated to the leftward asymmetry of fMRI activations, suggesting that the lateralization of the AF is a structural substrate of hemispheric language dominance. We found consistent connections between fMRI activations and terminations of the eight WM fascicles, providing a detailed description of the language connectome. WM fascicle terminations were also observed beyond fMRI-confirmed language areas and reached numerous cortical areas involved in different functional brain networks. These findings suggest that the reported WM fascicles are not exclusively involved in language and might be related to

  7. Perilesional and contralateral white matter evolution and integrity in patients with periventricular nodular heterotopia and epilepsy: a longitudinal diffusion tensor imaging study.

    Science.gov (United States)

    Liu, W; Yan, B; An, D; Niu, R; Tang, Y; Tong, X; Gong, Q; Zhou, D

    2017-12-01

    This study aimed to assess the evolution of perinodular and contralateral white matter abnormalities in patients with periventricular nodular heterotopia (PNH) and epilepsy. Diffusion tensor imaging (DTI) (64 directions) and 3 T structural magnetic resonance imaging were performed in 29 PNH patients (mean age 27.3 years), and 16 patients underwent a second scan (average time between the two scans 1.1 years). Fractional anisotropy and mean diffusivity were measured within the perilesional and contralateral white matter. Longitudinal analysis showed that white matter located 10 mm from the focal nodule displayed characteristics intermediate to tissue 5 mm away, and normal-appearing white matter (NAWM) also established evolution profiles of perinodular white matter in different cortical lobes. Compared to 29 age- and sex-matched healthy controls, significant decreased fractional anisotropy and elevated mean diffusivity values were observed in regions 5 and 10 mm from nodules (P < 0.01), whilst DTI metrics of the remaining NAWM did not differ significantly from controls. Additionally, normal DTI metrics were shown in the contralateral region in patients with unilateral PNH. Periventricular nodular heterotopia is associated with microstructural abnormalities within the perilesional white matter and the extent decreases with increasing distance from the nodule. In the homologous contralateral region, white matter diffusion metrics were unchanged in unilateral PNH. These findings have clinical implications with respect to the medical and surgical interventions of PNH-related epilepsy. © 2017 EAN.

  8. Neurons in the white matter of the adult human neocortex

    Directory of Open Access Journals (Sweden)

    M Luisa Suarez-Sola

    2009-06-01

    Full Text Available The white matter (WM of the adult human neocortex contains the so-called “interstitial neurons”. They are most numerous in the superficial WM underlying the cortical gyri, and decrease in density toward the deep WM. They are morphologically heterogeneous. A subgroup of interstitial neurons display pyramidal-cell like morphologies, characterized by a polarized dendritic tree with a dominant apical dendrite, and covered with a variable number of dendritic spines. In addition, a large contingent of interstitial neurons can be classified as interneurons based on their neurochemical profile as well as on morphological criteria. WM- interneurons have multipolar or bipolar shapes and express GABA and a variety of other neuronal markers, such as calbindin and calretinin, the extracellular matrix protein reelin, or neuropeptide Y, somatostatin, and nitric oxide synthase. The heterogeneity of interstitial neurons may be relevant for the pathogenesis of Alzheimer disease and schizophrenia. Interstitial neurons are most prominent in human brain, and only rudimentary in the brain of non-primate mammals. These evolutionary differences have precluded adequate experimental work on this cell population, which is usually considered as a relict of the subplate, a transient compartment proper of development and without a known function in the adult brain. The primate-specific prominence of the subplate in late fetal stages points to an important role in the establishment of interstitial neurons. Neurons in the adult WM may be actively involved in coordinating inter-areal connectivity and regulation of blood flow. Further studies in primates will be needed to elucidate the developmental history, adult components and activities of this large neuronal system.

  9. Functional connectivity and microstructural white matter changes in phenocopy frontotemporal dementia

    Energy Technology Data Exchange (ETDEWEB)

    Meijboom, R.; Steketee, R.M.E.; Lugt, A. van der; Smits, M. [Erasmus MC - University Medical Centre, Radiology and Nuclear Medicine, Rotterdam (Netherlands); Koning, I. de [Erasmus MC - University Medical Centre, Neuropsychology, Rotterdam (Netherlands); Osse, R.J. [Erasmus MC - University Medical Centre, Psychiatry, Rotterdam (Netherlands); Jiskoot, L.C. [Erasmus MC - University Medical Centre, Neuropsychology, Rotterdam (Netherlands); Erasmus MC - University Medical Centre, Neurology, Rotterdam (Netherlands); Jong, F.J. de; Swieten, J.C. van [Erasmus MC - University Medical Centre, Neurology, Rotterdam (Netherlands)

    2017-04-15

    Phenocopy frontotemporal dementia (phFTD) is a rare and poorly understood clinical syndrome. PhFTD shows core behavioural variant FTD (bvFTD) symptoms without associated cognitive deficits and brain abnormalities on conventional MRI and without progression. In contrast to phFTD, functional connectivity and white matter (WM) microstructural abnormalities have been observed in bvFTD. We hypothesise that phFTD belongs to the same disease spectrum as bvFTD and investigated whether functional connectivity and microstructural WM changes similar to bvFTD are present in phFTD. Seven phFTD patients without progression or alternative psychiatric diagnosis, 12 bvFTD patients and 17 controls underwent resting state functional MRI (rs-fMRI) and diffusion tensor imaging (DTI). Default mode network (DMN) connectivity and WM measures were compared between groups. PhFTD showed subtly increased DMN connectivity and subtle microstructural changes in frontal WM tracts. BvFTD showed abnormalities in similar regions as phFTD, but had lower increased DMN connectivity and more extensive microstructural WM changes. Our findings can be interpreted as neuropathological changes in phFTD and are in support of the hypothesis that phFTD and bvFTD may belong to the same disease spectrum. Advanced MRI techniques, objectively identifying brain abnormalities, would therefore be potentially suited to improve the diagnosis of phFTD. (orig.)

  10. Functional connectivity and microstructural white matter changes in phenocopy frontotemporal dementia

    International Nuclear Information System (INIS)

    Meijboom, R.; Steketee, R.M.E.; Lugt, A. van der; Smits, M.; Koning, I. de; Osse, R.J.; Jiskoot, L.C.; Jong, F.J. de; Swieten, J.C. van

    2017-01-01

    Phenocopy frontotemporal dementia (phFTD) is a rare and poorly understood clinical syndrome. PhFTD shows core behavioural variant FTD (bvFTD) symptoms without associated cognitive deficits and brain abnormalities on conventional MRI and without progression. In contrast to phFTD, functional connectivity and white matter (WM) microstructural abnormalities have been observed in bvFTD. We hypothesise that phFTD belongs to the same disease spectrum as bvFTD and investigated whether functional connectivity and microstructural WM changes similar to bvFTD are present in phFTD. Seven phFTD patients without progression or alternative psychiatric diagnosis, 12 bvFTD patients and 17 controls underwent resting state functional MRI (rs-fMRI) and diffusion tensor imaging (DTI). Default mode network (DMN) connectivity and WM measures were compared between groups. PhFTD showed subtly increased DMN connectivity and subtle microstructural changes in frontal WM tracts. BvFTD showed abnormalities in similar regions as phFTD, but had lower increased DMN connectivity and more extensive microstructural WM changes. Our findings can be interpreted as neuropathological changes in phFTD and are in support of the hypothesis that phFTD and bvFTD may belong to the same disease spectrum. Advanced MRI techniques, objectively identifying brain abnormalities, would therefore be potentially suited to improve the diagnosis of phFTD. (orig.)

  11. Working memory studies among individuals with intellectual disability: An integrative research review.

    Science.gov (United States)

    Lifshitz, Hefziba; Kilberg, Esther; Vakil, Eli

    2016-12-01

    Integrative research review infers generalizations about a substantive subject, summarizes the accumulated knowledge that research has left unresolved and generates a new framework on these issues. Due to methodological issues emerging from working memory (WM) studies in the population with non-specific intellectual disability (NSID) (N=64) between 1990-2014, it is difficult to conclude on WM performance in this population. This integrative research review aimed to resolve literature conflicts on WM performance among individuals with NSID and to identify the conditions/moderators that govern their WM performance compared to controls with Typical development. We used the six stages of integrative research review: problem formulation, data collection, evaluation, data analysis, results, interpretation and discussion. The findings indicate two types of moderators that determine WM performance in the population with NSID: Participants' moderators (criteria for matching the ID and TD groups, CA and MA), and task moderators [the three WM components of Baddeley and Hitch's (1974) model and task load]. Only an interaction between the two moderators determines WM performance in this population. The findings indicate a hierarchy (from more to less preserved) in WM performance of individuals with NSID: The visuospatial tasks, then some of the executive functions tasks, and the phonological loop tasks being less preserved. Furthermore, at a low level of control, the performance of participants with NSID was preserved beyond the modality and vice versa. Modality and MA/intelligence determine WM performance of individuals with ID. Educators should prepare intervention programs take the impact of the two moderators into account. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Brain size and white matter content of cerebrospinal tracts determine the upper cervical cord area: evidence from structural brain MRI

    Energy Technology Data Exchange (ETDEWEB)

    Engl, Christina; Arsic, Milan; Boucard, Christine C.; Biberacher, Viola; Nunnemann, Sabine; Muehlau, Mark [Technische Universitaet Muenchen, Department of Neurology, Klinikum rechts der Isar, Munich (Germany); Technische Universitaet Muenchen, TUM-Neuroimaging Center, Klinikum rechts der Isar, Munich (Germany); Schmidt, Paul [Technische Universitaet Muenchen, Department of Neurology, Klinikum rechts der Isar, Munich (Germany); Ludwig-Maximilians-University Muenchen, Department of Statistics, Munich (Germany); Roettinger, Michael [Technische Universitaet Muenchen, Department of Radiology, Klinikum rechts der Isar, Munich (Germany); Muenchner Institut fuer Neuroradiologie, Munich (Germany); Etgen, Thorleif [Technische Universitaet Muenchen, Department of Neurology, Klinikum rechts der Isar, Munich (Germany); Klinikum Traunstein, Department of Neurology, Traunstein (Germany); Koutsouleris, Nikolaos; Meisenzahl, Eva M. [Ludwig-Maximilians-Universitaet Muenchen, Department of Psychiatry and Psychotherapy, Munich (Germany); Reiser, Maximilian [Ludwig-Maximilians-Universitaet, Department of Radiology, Munich (Germany)

    2013-08-15

    Measurement of the upper cervical cord area (UCCA) from brain MRI may be an effective way to quantify spinal cord involvement in neurological disorders such as multiple sclerosis. However, knowledge on the determinants of UCCA in healthy controls (HCs) is limited. In two cohorts of 133 and 285 HCs, we studied the influence of different demographic, body-related, and brain-related parameters on UCCA by simple and partial correlation analyses as well as by voxel-based morphometry (VBM) across both cerebral gray matter (GM) and white matter (WM). First, we confirmed the known but moderate effect of age on UCCA in the older cohort. Second, we studied the correlation of UCCA with sex, body height, and total intracranial volume (TIV). TIV was the only variable that correlated significantly with UCCA after correction for the other variables. Third, we studied the correlation of UCCA with brain-related parameters. Brain volume correlated stronger with UCCA than TIV. Both volumes of the brain tissue compartments GM and WM correlated with UCCA significantly. WM volume explained variance of UCCA after correction for GM volume, whilst the opposite was not observed. Correspondingly, VBM did not yield any brain region, whose GM content correlated significantly with UCCA, whilst cerebral WM content of cerebrospinal tracts strongly correlated with UCCA. This latter effect increased along a craniocaudal gradient. UCCA is mainly determined by brain volume as well as by WM content of cerebrospinal tracts. (orig.)

  13. Smoking and the Developing Brain : Altered White Matter Microstructure in Attention-Deficit/Hyperactivity Disorder and Healthy Controls

    NARCIS (Netherlands)

    van Ewijk, Hanneke; Groenman, Annabeth P.; Zwiers, Marcel P.; Heslenfeld, Dirk J.; Faraone, Stephen V.; Hartman, Catharina A.; Luman, Marjolein; Greven, Corina U.; Hoekstra, Pieter J.; Franke, Barbara; Buitelaar, Jan; Oosterlaan, Jaap

    Brain white matter (WM) tracts, playing a vital role in the communication between brain regions, undergo important maturational changes during adolescence and young adulthood, a critical period for the development of nicotine dependence. Attention-deficit/hyperactivity disorder (ADHD) is associated

  14. The influence of comorbid oppositional defiant disorder on white matter microstructure in attention-deficit/hyperactivity disorder

    NARCIS (Netherlands)

    van Ewijk, Hanneke; Noordermeer, Siri D. S.; Heslenfeld, Dirk J.; Luman, Marjolein; Hartman, Catharina A.; Hoekstra, Pieter J.; Faraone, Stephen V.; Franke, Barbara; Buitelaar, Jan K.; Oosterlaan, J.

    Attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) are highly comorbid disorders. ADHD has been associated with altered white matter (WM) microstructure, though the literature is inconsistent, which may be due to differences in the in- or exclusion of

  15. Nonlocal gravity simulates dark matter

    OpenAIRE

    Hehl, Friedrich W.; Mashhoon, Bahram

    2009-01-01

    A nonlocal generalization of Einstein's theory of gravitation is constructed within the framework of the translational gauge theory of gravity. In the linear approximation, the nonlocal theory can be interpreted as linearized general relativity but in the presence of "dark matter" that can be simply expressed as an integral transform of matter. It is shown that this approach can accommodate the Tohline-Kuhn treatment of the astrophysical evidence for dark matter.

  16. D matter

    International Nuclear Information System (INIS)

    Shiu, Gary; Wang Liantao

    2004-01-01

    We study the properties and phenomenology of particlelike states originating from D branes whose spatial dimensions are all compactified. They are nonperturbative states in string theory and we refer to them as D matter. In contrast to other nonperturbative objects such as 't Hooft-Polyakov monopoles, D-matter states could have perturbative couplings among themselves and with ordinary matter. The lightest D particle (LDP) could be stable because it is the lightest state carrying certain (integer or discrete) quantum numbers. Depending on the string scale, they could be cold dark matter candidates with properties similar to that of WIMPs or wimpzillas. The spectrum of excited states of D matter exhibits an interesting pattern which could be distinguished from that of Kaluza-Klein modes, winding states, and string resonances. We speculate about possible signatures of D matter from ultrahigh energy cosmic rays and colliders

  17. Dark Matter

    International Nuclear Information System (INIS)

    Holt, S. S.; Bennett, C. L.

    1995-01-01

    These proceedings represent papers presented at the Astrophysics conference in Maryland, organized by NASA Goddard Space Flight Center and the University of Maryland. The topics covered included low mass stars as dark matter, dark matter in galaxies and clusters, cosmic microwave background anisotropy, cold and hot dark matter, and the large scale distribution and motions of galaxies. There were eighty five papers presented. Out of these, 10 have been abstracted for the Energy Science and Technology database

  18. No Evidence That Short-Term Cognitive or Physical Training Programs or Lifestyles Are Related to Changes in White Matter Integrity in Older Adults at Risk of Dementia.

    Science.gov (United States)

    Fissler, Patrick; Müller, Hans-Peter; Küster, Olivia C; Laptinskaya, Daria; Thurm, Franka; Woll, Alexander; Elbert, Thomas; Kassubek, Jan; von Arnim, Christine A F; Kolassa, Iris-Tatjana

    2017-01-01

    Cognitive and physical activities can benefit cognition. However, knowledge about the neurobiological mechanisms underlying these activity-induced cognitive benefits is still limited, especially with regard to the role of white matter integrity (WMI), which is affected in cognitive aging and Alzheimer's disease. To address this knowledge gap, we investigated the immediate and long-term effects of cognitive or physical training on WMI, as well as the association between cognitive and physical lifestyles and changes in WMI over a 6-month period. Additionally, we explored whether changes in WMI underlie activity-related cognitive changes, and estimated the potential of both trainings to improve WMI by correlating training outcomes with WMI. In an observational and interventional pretest, posttest, 3-month follow-up design, we assigned 47 community-dwelling older adults at risk of dementia to 50 sessions of auditory processing and working memory training ( n = 13), 50 sessions of cardiovascular, strength, coordination, balance and flexibility exercises ( n = 14), or a control group ( n = 20). We measured lifestyles trough self-reports, cognitive training skills through training performance, functional physical fitness through the Senior Fitness Test, and global cognition through a cognitive test battery. WMI was assessed via a composite score of diffusion tensor imaging-based fractional anisotropy (FA) of three regions of interest shown to be affected in aging and Alzheimer's disease: the genu of corpus callosum, the fornix, and the hippocampal cingulum. Effects for training interventions on FA outcomes, as well as associations between lifestyles and changes in FA outcomes were not significant. Additional analyses did show associations between cognitive lifestyle and global cognitive changes at the posttest and the 3-month follow-up (β ≥ 0.40, p ≤ 0.02) and accounting for changes in WMI did not affect these relationships. The targeted training outcomes were

  19. Dark Matter

    International Nuclear Information System (INIS)

    Bashir, A.; Cotti, U.; De Leon, C. L.; Raya, A; Villasenor, L.

    2008-01-01

    One of the biggest scientific mysteries of our time resides in the identification of the particles that constitute a large fraction of the mass of our Universe, generically known as dark matter. We review the observations and the experimental data that imply the existence of dark matter. We briefly discuss the properties of the two best dark-matter candidate particles and the experimental techniques presently used to try to discover them. Finally, we mention a proposed project that has recently emerged within the Mexican community to look for dark matter

  20. Neuroinflammatory component of gray matter pathology in multiple sclerosis.

    Science.gov (United States)

    Herranz, Elena; Giannì, Costanza; Louapre, Céline; Treaba, Constantina A; Govindarajan, Sindhuja T; Ouellette, Russell; Loggia, Marco L; Sloane, Jacob A; Madigan, Nancy; Izquierdo-Garcia, David; Ward, Noreen; Mangeat, Gabriel; Granberg, Tobias; Klawiter, Eric C; Catana, Ciprian; Hooker, Jacob M; Taylor, Norman; Ionete, Carolina; Kinkel, Revere P; Mainero, Caterina

    2016-11-01

    In multiple sclerosis (MS), using simultaneous magnetic resonance-positron emission tomography (MR-PET) imaging with 11 C-PBR28, we quantified expression of the 18kDa translocator protein (TSPO), a marker of activated microglia/macrophages, in cortex, cortical lesions, deep gray matter (GM), white matter (WM) lesions, and normal-appearing WM (NAWM) to investigate the in vivo pathological and clinical relevance of neuroinflammation. Fifteen secondary-progressive MS (SPMS) patients, 12 relapsing-remitting MS (RRMS) patients, and 14 matched healthy controls underwent 11 C-PBR28 MR-PET. MS subjects underwent 7T T2*-weighted imaging for cortical lesion segmentation, and neurological and cognitive evaluation. 11 C-PBR28 binding was measured using normalized 60- to 90-minute standardized uptake values and volume of distribution ratios. Relative to controls, MS subjects exhibited abnormally high 11 C-PBR28 binding across the brain, the greatest increases being in cortex and cortical lesions, thalamus, hippocampus, and NAWM. MS WM lesions showed relatively modest TSPO increases. With the exception of cortical lesions, where TSPO expression was similar, 11 C-PBR28 uptake across the brain was greater in SPMS than in RRMS. In MS, increased 11 C-PBR28 binding in cortex, deep GM, and NAWM correlated with neurological disability and impaired cognitive performance; cortical thinning correlated with increased thalamic TSPO levels. In MS, neuroinflammation is present in the cortex, cortical lesions, deep GM, and NAWM, is closely linked to poor clinical outcome, and is at least partly linked to neurodegeneration. Distinct inflammatory-mediated factors may underlie accumulation of cortical and WM lesions. Quantification of TSPO levels in MS could prove to be a sensitive tool for evaluating in vivo the inflammatory component of GM pathology, particularly in cortical lesions. Ann Neurol 2016;80:776-790. © 2016 American Neurological Association.

  1. Intracranial Fluid Redistribution But No White Matter Microstructural Changes During a Spaceflight Analog.

    Science.gov (United States)

    Koppelmans, Vincent; Pasternak, Ofer; Bloomberg, Jacob J; Dios, Yiri E De; Wood, Scott J; Riascos, Roy; Reuter-Lorenz, Patricia A; Kofman, Igor S; Mulavara, Ajitkumar P; Seidler, Rachael D

    2017-06-09

    The neural correlates of spaceflight-induced sensorimotor impairments are unknown. Head down-tilt bed rest (HDBR) serves as a microgravity analog because it mimics the headward fluid shift and axial body unloading of spaceflight. We investigated focal brain white matter (WM) changes and fluid shifts during 70 days of 6° HDBR in 16 subjects who were assessed pre (2x), during (3x), and post-HDBR (2x). Changes over time were compared to those in control subjects (n = 12) assessed four times over 90 days. Diffusion MRI was used to assess WM microstructure and fluid shifts. Free-Water Imaging was used to quantify distribution of intracranial extracellular free water (FW). Additionally, we tested whether WM and FW changes correlated with changes in functional mobility and balance measures. HDBR resulted in FW increases in fronto-temporal regions and decreases in posterior-parietal regions that largely recovered by two weeks post-HDBR. WM microstructure was unaffected by HDBR. FW decreases in the post-central gyrus and precuneus correlated negatively with balance changes. We previously reported that gray matter increases in these regions were associated with less HDBR-induced balance impairment, suggesting adaptive structural neuroplasticity. Future studies are warranted to determine causality and underlying mechanisms.

  2. Obesity Associated Cerebral Gray and White Matter Alterations Are Interrelated in the Female Brain.

    Directory of Open Access Journals (Sweden)

    Karsten Mueller

    Full Text Available Obesity is known to affect the brain's gray matter (GM and white matter (WM structure but the interrelationship of such changes remains unclear. Here we used T1-weighted magnetic resonance imaging (MRI in combination with voxel-based morphometry (VBM and diffusion-tensor imaging (DTI with tract-based spatial statistics (TBSS to assess the relationship between obesity-associated alterations of gray matter density (GMD and anisotropic water diffusion in WM, respectively. In a small cohort of lean to obese women, we confirmed previous reports of obesity-associated alterations of GMD in brain regions involved in executive control (i.e., dorsolateral prefrontal cortex, DLPFC and habit learning (i.e., dorsal striatum. Gray matter density alterations of the DLPFC were negatively correlated with radial diffusivity in the entire corpus callosum. Within the genu of the corpus callosum we found a positive correlation with axial diffusivity. In posterior region and inferior areas of the body of the corpus callosum, axial diffusivity correlated negatively with altered GMD in the dorsal striatum. These findings suggest that, in women, obesity-related alterations of GMD in brain regions involved in executive control and habit learning might relate to alterations of associated WM fiber bundles within the corpus callosum.

  3. Gaseous Matter

    CERN Document Server

    Angelo, Joseph A

    2011-01-01

    aseous Matter focuses on the many important discoveries that led to the scientific interpretation of matter in the gaseous state. This new, full-color resource describes the basic characteristics and properties of several important gases, including air, hydrogen, helium, oxygen, and nitrogen. The nature and scope of the science of fluids is discussed in great detail, highlighting the most important scientific principles upon which the field is based. Chapters include:. Gaseous Matter An Initial Perspective. Physical Characteristics of Gases. The Rise of the Science of Gases. Kinetic Theory of

  4. White Matter Structural Connectivity Is Not Correlated to Cortical Resting-State Functional Connectivity over the Healthy Adult Lifespan

    Directory of Open Access Journals (Sweden)

    Adrian Tsang

    2017-05-01

    Full Text Available Structural connectivity (SC of white matter (WM and functional connectivity (FC of cortical regions undergo changes in normal aging. As WM tracts form the underlying anatomical architecture that connects regions within resting state networks (RSNs, it is intuitive to expect that SC and FC changes with age are correlated. Studies that investigated the relationship between SC and FC in normal aging are rare, and have mainly compared between groups of elderly and younger subjects. The objectives of this work were to investigate linear SC and FC changes across the healthy adult lifespan, and to define relationships between SC and FC measures within seven whole-brain large scale RSNs. Diffusion tensor imaging (DTI and resting-state functional MRI (rs-fMRI data were acquired from 177 healthy participants (male/female = 69/108; aged 18–87 years. Forty cortical regions across both hemispheres belonging to seven template-defined RSNs were considered. Mean diffusivity (MD, fractional anisotropy (FA, mean tract length, and number of streamlines derived from DTI data were used as SC measures, delineated using deterministic tractography, within each RSN. Pearson correlation coefficients of rs-fMRI-obtained BOLD signal time courses between cortical regions were used as FC measure. SC demonstrated significant age-related changes in all RSNs (decreased FA, mean tract length, number of streamlines; and increased MD, and significant FC decrease was observed in five out of seven networks. Among the networks that showed both significant age related changes in SC and FC, however, SC was not in general significantly correlated with FC, whether controlling for age or not. The lack of observed relationship between SC and FC suggests that measures derived from DTI data that are commonly used to infer the integrity of WM microstructure are not related to the corresponding changes in FC within RSNs. The possible temporal lag between SC and FC will need to be addressed

  5. Metric to quantify white matter damage on brain magnetic resonance images

    International Nuclear Information System (INIS)

    Valdes Hernandez, Maria del C.; Munoz Maniega, Susana; Anblagan, Devasuda; Bastin, Mark E.; Wardlaw, Joanna M.; Chappell, Francesca M.; Morris, Zoe; Sakka, Eleni; Dickie, David Alexander; Royle, Natalie A.; Armitage, Paul A.; Deary, Ian J.

    2017-01-01

    Quantitative assessment of white matter hyperintensities (WMH) on structural Magnetic Resonance Imaging (MRI) is challenging. It is important to harmonise results from different software tools considering not only the volume but also the signal intensity. Here we propose and evaluate a metric of white matter (WM) damage that addresses this need. We obtained WMH and normal-appearing white matter (NAWM) volumes from brain structural MRI from community dwelling older individuals and stroke patients enrolled in three different studies, using two automatic methods followed by manual editing by two to four observers blind to each other. We calculated the average intensity values on brain structural fluid-attenuation inversion recovery (FLAIR) MRI for the NAWM and WMH. The white matter damage metric is calculated as the proportion of WMH in brain tissue weighted by the relative image contrast of the WMH-to-NAWM. The new metric was evaluated using tissue microstructure parameters and visual ratings of small vessel disease burden and WMH: Fazekas score for WMH burden and Prins scale for WMH change. The correlation between the WM damage metric and the visual rating scores (Spearman ρ > =0.74, p =0.72, p < 0.0001). The repeatability of the WM damage metric was better than WM volume (average median difference between measurements 3.26% (IQR 2.76%) and 5.88% (IQR 5.32%) respectively). The follow-up WM damage was highly related to total Prins score even when adjusted for baseline WM damage (ANCOVA, p < 0.0001), which was not always the case for WMH volume, as total Prins was highly associated with the change in the intense WMH volume (p = 0.0079, increase of 4.42 ml per unit change in total Prins, 95%CI [1.17 7.67]), but not with the change in less-intense, subtle WMH, which determined the volumetric change. The new metric is practical and simple to calculate. It is robust to variations in image processing methods and scanning protocols, and sensitive to subtle and severe white

  6. Metric to quantify white matter damage on brain magnetic resonance images

    Energy Technology Data Exchange (ETDEWEB)

    Valdes Hernandez, Maria del C.; Munoz Maniega, Susana; Anblagan, Devasuda; Bastin, Mark E.; Wardlaw, Joanna M. [University of Edinburgh, Department of Neuroimaging Sciences, Centre for Clinical Brain Sciences, Edinburgh (United Kingdom); University of Edinburgh, Centre for Cognitive Ageing and Cognitive Epidemiology, Edinburgh (United Kingdom); UK Dementia Research Institute, Edinburgh Dementia Research Centre, London (United Kingdom); Chappell, Francesca M.; Morris, Zoe; Sakka, Eleni [University of Edinburgh, Department of Neuroimaging Sciences, Centre for Clinical Brain Sciences, Edinburgh (United Kingdom); UK Dementia Research Institute, Edinburgh Dementia Research Centre, London (United Kingdom); Dickie, David Alexander; Royle, Natalie A. [University of Edinburgh, Department of Neuroimaging Sciences, Centre for Clinical Brain Sciences, Edinburgh (United Kingdom); University of Edinburgh, Centre for Cognitive Ageing and Cognitive Epidemiology, Edinburgh (United Kingdom); Armitage, Paul A. [University of Sheffield, Department of Cardiovascular Sciences, Sheffield (United Kingdom); Deary, Ian J. [University of Edinburgh, Centre for Cognitive Ageing and Cognitive Epidemiology, Edinburgh (United Kingdom); University of Edinburgh, Department of Psychology, Edinburgh (United Kingdom)

    2017-10-15

    Quantitative assessment of white matter hyperintensities (WMH) on structural Magnetic Resonance Imaging (MRI) is challenging. It is important to harmonise results from different software tools considering not only the volume but also the signal intensity. Here we propose and evaluate a metric of white matter (WM) damage that addresses this need. We obtained WMH and normal-appearing white matter (NAWM) volumes from brain structural MRI from community dwelling older individuals and stroke patients enrolled in three different studies, using two automatic methods followed by manual editing by two to four observers blind to each other. We calculated the average intensity values on brain structural fluid-attenuation inversion recovery (FLAIR) MRI for the NAWM and WMH. The white matter damage metric is calculated as the proportion of WMH in brain tissue weighted by the relative image contrast of the WMH-to-NAWM. The new metric was evaluated using tissue microstructure parameters and visual ratings of small vessel disease burden and WMH: Fazekas score for WMH burden and Prins scale for WMH change. The correlation between the WM damage metric and the visual rating scores (Spearman ρ > =0.74, p < 0.0001) was slightly stronger than between the latter and WMH volumes (Spearman ρ > =0.72, p < 0.0001). The repeatability of the WM damage metric was better than WM volume (average median difference between measurements 3.26% (IQR 2.76%) and 5.88% (IQR 5.32%) respectively). The follow-up WM damage was highly related to total Prins score even when adjusted for baseline WM damage (ANCOVA, p < 0.0001), which was not always the case for WMH volume, as total Prins was highly associated with the change in the intense WMH volume (p = 0.0079, increase of 4.42 ml per unit change in total Prins, 95%CI [1.17 7.67]), but not with the change in less-intense, subtle WMH, which determined the volumetric change. The new metric is practical and simple to calculate. It is robust to variations in

  7. Thyroxin treatment protects against white matter injury in the immature brain via brain-derived neurotrophic factor.

    Science.gov (United States)

    Hung, Pi-Lien; Huang, Chao-Ching; Huang, Hsiu-Mei; Tu, Dom-Gene; Chang, Ying-Chao

    2013-08-01

    Low level of thyroid hormone is a strong independent risk factor for white matter (WM) injury, a major cause of cerebral palsy, in preterm infants. Thyroxin upregulates brain-derived neurotrophic factor during development. We hypothesized that thyroxin protected against preoligodendrocyte apoptosis and WM injury in the immature brain via upregulation of brain-derived neurotrophic factor. Postpartum (P) day-7 male rat pups were exposed to hypoxic ischemia (HI) and intraperitoneally injected with thyroxin (T4; 0.2 mg/kg or 1 mg/kg) or normal saline immediately after HI at P9 and P11. WM damage was analyzed for myelin formation, axonal injury, astrogliosis, and preoligodendrocyte apoptosis. Neurotrophic factor expression was assessed by real-time polymerase chain reaction and immunohistochemistry. Neuromotor functions were measured using open-field locomotion (P11 and P21), inclined plane climbing (P11), and beam walking (P21). Intracerebroventricular injection of TrkB-Fc or systemic administration of 7,8-dihydroxyflavone was performed. On P11, the HI group had significantly lower blood T4 levels than the controls. The HI group showed ventriculomegaly and marked reduction of myelin basic protein immunoreactivities in the WM. T4 (1 mg/kg) treatment after HI markedly attenuated axonal injury, astrocytosis, and microgliosis, and increased preoligodendrocyte survival. In addition, T4 treatment significantly increased myelination and selectively upregulated brain-derived neurotrophic factor expression in the WM, and improved neuromotor deficits after HI. The protective effect of T4 on WM myelination and neuromotor performance after HI was significantly attenuated by TrkB-Fc. Systemic 7,8-dihydroxyflavone treatment ameliorated hypomyelination after HI injury. T4 protects against WM injury at both pathological and functional levels via upregulation of brain-derived neurotrophic factor-TrkB signaling in the immature brain.

  8. Dark matters

    International Nuclear Information System (INIS)

    Silk, Joseph

    2010-01-01

    One of the greatest mysteries in the cosmos is that it is mostly dark. That is, not only is the night sky dark, but also most of the matter and the energy in the universe is dark. For every atom visible in planets, stars and galaxies today there exists at least five or six times as much 'Dark Matter' in the universe. Astronomers and particle physicists today are seeking to unravel the nature of this mysterious but pervasive dark matter, which has profoundly influenced the formation of structure in the universe. Dark energy remains even more elusive, as we lack candidate fields that emerge from well established physics. I will describe various attempts to measure dark matter by direct and indirect means, and discuss the prospects for progress in unravelling dark energy.

  9. Dirac matter

    CERN Document Server

    Rivasseau, Vincent; Fuchs, Jean-Nöel

    2017-01-01

    This fifteenth volume of the Poincare Seminar Series, Dirac Matter, describes the surprising resurgence, as a low-energy effective theory of conducting electrons in many condensed matter systems, including graphene and topological insulators, of the famous equation originally invented by P.A.M. Dirac for relativistic quantum mechanics. In five highly pedagogical articles, as befits their origin in lectures to a broad scientific audience, this book explains why Dirac matters. Highlights include the detailed "Graphene and Relativistic Quantum Physics", written by the experimental pioneer, Philip Kim, and devoted to graphene, a form of carbon crystallized in a two-dimensional hexagonal lattice, from its discovery in 2004-2005 by the future Nobel prize winners Kostya Novoselov and Andre Geim to the so-called relativistic quantum Hall effect; the review entitled "Dirac Fermions in Condensed Matter and Beyond", written by two prominent theoreticians, Mark Goerbig and Gilles Montambaux, who consider many other mater...

  10. 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...

  11. Análise microbiológica de gastroscópios descontaminados em aparelho Cleantop WM-1 por uso de água eletrolítica ácida Microbiological evaluation of gastroscope decontamination by electrolysed acid water (Clentop WM-1

    Directory of Open Access Journals (Sweden)

    Alexandre Paulo Machado

    2005-03-01

    Full Text Available RACIONAL: O método com utilização manual de glutaraldeído é amplamente empregado para desinfecção de endoscópios. A elevada rotina nos serviços de gastroscopia, pequena quantidade de equipamentos e a falta de conhecimento técnico sobre os processos de descontaminação contribuem para desinfecção inadequada dos endoscópios, intensificando o risco de transmissão de microrganismos. A água eletrolítica ácida tem apresentado eficácia na inativação e destruição de microrganismos e vem sendo usada na descontaminação de endoscópios. OBJETIVO: Verificar a eficiência microbicida da água eletrolítica ácida, produzida pelo aparelho Cleantop WM-1, em 20 gastroscópios contaminados após uso em pacientes. MATERIAL E MÉTODOS: Amostras coletadas do canal de biopsia dos endoscópios, após uso em pacientes (n = 20 e depois da desinfecção (n = 20, foram cultivadas em ágar tripticaseína de soja, MacConkey e Sabouraud dextrose. RESULTADOS: Dezessete das 20 amostras coletadas após o uso do aparelho em pacientes revelaram a presença de bacilos gram-negativos, cocos gram-positivos e leveduras em taxas de 10³ a 10(5 ufc/mL. Nenhuma amostra, das 20 coletadas após a descontaminação, apresentou contaminação microbiana. CONCLUSÃO: Nesse estudo preliminar, a desinfecção mecânica realizada pelo aparelho Cleantop com água eletrolítica ácida revelou resultados satisfatórios pela eliminação de microrganismos e otimização no tempo de processamento dos gastroscópiosBACKGROUND: The manual disinfection of endoscopes with glutharaldeyde is widely employed. The great routine in gastroenteroscopy services, low number of equipment and the lack of technical knowledge about the decontamination processes are factors that stimulate the inadequate endoscope disinfection, intensifying the risk of transmission of microorganisms. The electrolysed acid water has been effective in the inactivation and destruction of microorganisms. AIM: The

  12. Corpus callosum vasculature predicts white matter microstructure abnormalities following pediatric mild traumatic brain injury.

    Science.gov (United States)

    Wendel, Kara M; Lee, Jeong Bin; Affeldt, Bethann; Hamer, Mary; Harahap-Carrillo, Indira S; Pardo, Andrea C; Obenaus, Andre

    2018-05-09

    Emerging data suggest that pediatric traumatic brain injury (TBI) is associated with impaired developmental plasticity and poorer neuropsychological outcomes than adults with similar head injuries. Unlike adult mild TBI (mTBI), the effects of mTBI on white matter (WM) microstructure and vascular supply are not well-understood in the pediatric population. The cerebral vasculature plays an important role providing necessary nutrients and removing waste. To address this critical element, we examined the microstructure of the corpus callosum (CC) following pediatric mTBI using diffusion tensor imaging (DTI), and investigated myelin, oligodendrocytes, and vasculature of WM with immunohistochemistry. We hypothesized that pediatric mTBI leads to abnormal WM microstructure and impacts the vasculature within the CC, and that these alterations to WM vasculature contribute to the long-term altered microstructure. We induced a closed head injury mTBI at postnatal day 14, then at 4, 14, and 60 days post injury (DPI) mice were sacrificed for analysis. We observed persistent changes in apparent diffusion coefficient (ADC) within the ipsilateral CC following mTBI, indicating microstructural changes, but surprisingly changes in myelin and oligodendrocyte densities were minimal. However, vasculature features of the ipsilateral CC such as vessel density, length, and number of junctions were persistently altered following mTBI. Correlative analysis showed a strong inverse relationship between ADC and vessel density at 60 DPI, suggesting increased vessel density following mTBI may restrict WM diffusion characteristics. Our findings suggest that WM vasculature contributes to the long-term microstructural changes within the ipsilateral CC following mTBI.

  13. White Matter Microstructural Abnormalities in Type 2 Diabetes Mellitus: A Diffusional Kurtosis Imaging Analysis.

    Science.gov (United States)

    Xie, Y; Zhang, Y; Qin, W; Lu, S; Ni, C; Zhang, Q

    2017-03-01

    Increasing DTI studies have demonstrated that white matter microstructural abnormalities play an important role in type 2 diabetes mellitus-related cognitive impairment. In this study, the diffusional kurtosis imaging method was used to investigate WM microstructural alterations in patients with type 2 diabetes mellitus and to detect associations between diffusional kurtosis imaging metrics and clinical/cognitive measurements. Diffusional kurtosis imaging and cognitive assessments were performed on 58 patients with type 2 diabetes mellitus and 58 controls. Voxel-based intergroup comparisons of diffusional kurtosis imaging metrics were conducted, and ROI-based intergroup comparisons were further performed. Correlations between the diffusional kurtosis imaging metrics and cognitive/clinical measurements were assessed after controlling for age, sex, and education in both patients and controls. Altered diffusion metrics were observed in the corpus callosum, the bilateral frontal WM, the right superior temporal WM, the left external capsule, and the pons in patients with type 2 diabetes mellitus compared with controls. The splenium of the corpus callosum and the pons had abnormal kurtosis metrics in patients with type 2 diabetes mellitus. Additionally, altered diffusion metrics in the right prefrontal WM were significantly correlated with disease duration and attention task performance in patients with type 2 diabetes mellitus. With both conventional diffusion and additional kurtosis metrics, diffusional kurtosis imaging can provide additional information on WM microstructural abnormalities in patients with type 2 diabetes mellitus. Our results indicate that WM microstructural abnormalities occur before cognitive decline and may be used as neuroimaging markers for predicting the early cognitive impairment in patients with type 2 diabetes mellitus. © 2017 by American Journal of Neuroradiology.

  14. Impaired white matter connections of the limbic system networks associated with impaired emotional memory in Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Xiaoshu Li

    2016-10-01

    Full Text Available Background: Discrepancies persist regarding retainment of emotional enhancement of memory (EEM in mild cognitive impairment (MCI and early Alzheimer’s disease (AD patients. In addition, the neural mechanisms are still poorly understood, little is known about emotional memory related changes in white matter (WM.Objective: To observe whether EEM is absent in amnestic MCI (aMCI and AD patients, and to investigate if emotional memory is associated with WM connections and gray matters (GM of the limbic system networks. Methods: Twenty-one AD patients, 20 aMCI patients and 25 normal controls participated in emotional picture recognition tests and MRI scanning. Tract-based spatial statistics (TBSS and voxel-based morphometry (VBM methods were used to determine white and gray matter changes of patients. Fourteen regions of interest (ROI of WM and 20 ROIs of GM were then selected for the correlation analyses with behavioral scores. Results: The EEM effect was lost in AD patients. Both white and gray matter of the limbic system networks were impaired in AD patients. Significant correlations or tendencies between the bilateral uncinate fasciculus, corpus callosum (genu and body, left cingulum bundle, left parahippocampal WM and the recognition sensitivity of emotional valence pictures, and significant correlations or tendencies between the splenium of corpus callosum, left cingulum bundle, left crus of fornix and stria terminalis and the recognition sensitivity of EEM were found. The volume of left amygdala, bilateral insula, medial frontal lobe, anterior and middle cingulum gyrus were positively correlated with the recognition sensitivity of emotional photos, and the right precuneus was positively correlated with the negative EEM effect. However, the affected brain areas of aMCI patients were more localized, and aMCI patients benefited only from positive stimuli. Conclusion: There are impairments of the limbic system networks of AD patients. Damaged WM

  15. Alterations in Cortical Thickness and White Matter Integrity in Mild-to-Moderate Communicating Hydrocephalic School-Aged Children Measured by Whole-Brain Cortical Thickness Mapping and DTI

    Directory of Open Access Journals (Sweden)

    Siyu Zhang

    2017-01-01

    Full Text Available Follow-up observation is required for mild-to-moderate hydrocephalic patients because of the potential damage to brain. However, effects of mild-to-moderate hydrocephalus on gray and white matter remain unclear in vivo. Using structural MRI and diffusion tensor imaging (DTI, current study compared the cortical thickness and white matter integrity between children with mild-to-moderate communicating hydrocephalus and healthy controls. The relationships between cortical changes and intelligence quota were also examined in patients. We found that cortical thickness in the left middle temporal and left rostral middle frontal gyrus was significantly lower in the hydrocephalus group compared with that of controls. Fractional anisotropy in the right corpus callosum body was significantly lower in the hydrocephalus group compared with that of controls. In addition, there was no association of cortical thinning or white matter fractional anisotropy with intelligence quota in either group. Thus, our findings provide clues to that mild-to-moderate hydrocephalus could lead to structural brain deficits especially in the middle temporal and middle frontal gyrus prior to the behavior changes.

  16. The influence of comorbid oppositional defiant disorder on white matter microstructure in attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    van Ewijk, Hanneke; Noordermeer, Siri D S; Heslenfeld, Dirk J; Luman, Marjolein; Hartman, Catharina A; Hoekstra, Pieter J; Faraone, Stephen V; Franke, Barbara; Buitelaar, Jan K; Oosterlaan, J

    2016-07-01

    Attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) are highly comorbid disorders. ADHD has been associated with altered white matter (WM) microstructure, though the literature is inconsistent, which may be due to differences in the in- or exclusion of participants with comorbid ODD. WM abnormalities in ODD are still poorly understood, and it is unclear whether comorbid ODD in ADHD may have confounded the current ADHD literature. Diffusion Tensor Imaging (DTI) was used to compare fractional anisotropy (FA) and mean diffusivity (MD) between ADHD patients with (n = 42) and without (n = 117) comorbid ODD. All participants were between 8-25 years and groups did not differ in mean age or gender. Follow-up analyses were conducted to examine the role of antisocial behaviour (conduct problems) on FA and MD values in both groups. Comorbid ODD in ADHD was associated with lower FA in left frontotemporal WM, which appeared independent of ADHD symptoms. FA was negatively associated with antisocial behaviour in ADHD + ODD, but not in ADHD-only. Comorbid ODD is associated with WM abnormalities in individuals with ADHD, which appears to be independent of ADHD symptoms. Altered WM microstructure in comorbid ODD may play a role in inconsistencies in the current DTI literature in ADHD. Altered development of these tracts may contribute to social-emotional and cognitive problems in children with oppositional and antisocial behaviour.

  17. Quality and quantity of diffuse and focal white matter disease and cognitive disability of patients with multiple sclerosis.

    Science.gov (United States)

    Bomboi, Giuseppe; Ikonomidou, Vasiliki N; Pellegrini, Stefano; Stern, Susan K; Gallo, Antonio; Auh, Sungyoung; Evangelou, Iordanis E; Agarwal, Jhalak; Pellicano, Clelia; Ohayon, Joan M; Cantor, Fredric K; Ehrmantraut, Mary; McFarland, Henry F; Kane, Robert L; Bagnato, Francesca

    2011-04-01

    Using high-field magnetic resonance imaging (MRI), we investigated the relationships between white matter (WM) lesion volume (LV), normal-appearing WM (NAWM) normalized volume, WM-lesion and NAWM magnetization transfer ratios (MTRs), brain parenchyma fraction (BPF), and cognitive impairment (CI) in multiple sclerosis (MS). Twenty-four patients and 24 healthy volunteers (age, sex, and years of education-matched) underwent a 3.0 Tesla (3T) scan and evaluation of depression, fatigue, and CI using the Minimal Assessment of Cognitive Function in MS (MACFIMS) battery. In this clinically relatively well-preserved cohort of patients (median score on the Expanded Disability Status Scale=1.5), CI was detected on Symbol Digit Modalities Test (SDMT), California Verbal Learning Test-II (CVLT-II), and Controlled Oral Word Association Test. MT data were available in 19 pairs on whom correlation analyses were performed. Associations were seen between SDMT and normalized NAWM volume (P=.034, r=.502), CVLT-II long delay and normalized NAWM volume (P=.012, r=.563), WM-LV (P=.024, r=.514), and BPF (P=.002, r=.666). The use of 3T MRI in a sample of clinically stable MS patients shows the importance of WM disease in hampering processing speed and word retrieval. Copyright © 2010 by the American Society of Neuroimaging.

  18. White matter tract network disruption explains reduced conscientiousness in multiple sclerosis.

    Science.gov (United States)

    Fuchs, Tom A; Dwyer, Michael G; Kuceyeski, Amy; Choudhery, Sanjeevani; Carolus, Keith; Li, Xian; Mallory, Matthew; Weinstock-Guttman, Bianca; Jakimovski, Dejan; Ramasamy, Deepa; Zivadinov, Robert; Benedict, Ralph H B

    2018-05-08

    Quantifying white matter (WM) tract disruption in people with multiple sclerosis (PwMS) provides a novel means for investigating the relationship between defective network connectivity and clinical markers. PwMS exhibit perturbations in personality, where decreased Conscientiousness is particularly prominent. This trait deficit influences disease trajectory and functional outcomes such as work capacity. We aimed to identify patterns of WM tract disruption related to decreased Conscientiousness in PwMS. Personality assessment and brain MRI were obtained in 133 PwMS and 49 age- and sex-matched healthy controls (HC). Lesion maps were applied to determine the severity of WM tract disruption between pairs of gray matter regions. Next, the Network-Based-Statistics tool was applied to identify structural networks whose disruption negatively correlates with Conscientiousness. Finally, to determine whether these networks explain unique variance above conventional MRI measures and cognition, regression models were applied controlling for age, sex, brain volume, T2-lesion volume, and cognition. Relative to HCs, PwMS exhibited lower Conscientiousness and slowed cognitive processing speed (p = .025, p = .006). Lower Conscientiousness in PwMS was significantly associated with WM tract disruption between frontal, frontal-parietal, and frontal-cingulate pathways in the left (p = .02) and right (p = .01) hemisphere. The mean disruption of these pathways explained unique additive variance in Conscientiousness, after accounting for conventional MRI markers of pathology and cognition (ΔR 2  = .049, p = .029). Damage to WM tracts between frontal, frontal-parietal, and frontal-cingulate cortical regions is significantly correlated with reduced Conscientiousness in PwMS. Tract disruption within these networks explains decreased Conscientiousness observed in PwMS as compared with HCs. © 2018 Wiley Periodicals, Inc.

  19. An investigation of the influence of strength mis-matching and HAZ width on the fracture behaviour of welds with cracks in the WM/HAZ interface

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, D.M.; Menezes, L.F.; Loureiro, A. [Dept of Mechanical Eng., FCTUC, Coimbra (Portugal)

    2004-07-01

    In this paper a numerical study concerning the influence of the mis-match in mechanical properties and of the heat affected zone width on the crack driving force of welds with cracks in the weld metal / heat affected zone interface is described. This work was performed through the numerical simulation of three-point bending tests, using finite element meshes of weld samples with various HAZ widths and two different crack length sizes. The numerical calculation of the J integral and of the stress fields ahead the notch tip was used to evaluate the fracture strength variation in the welds. (orig.)

  20. Night sleep influences white matter microstructure in bipolar depression.

    Science.gov (United States)

    Benedetti, Francesco; Melloni, Elisa M T; Dallaspezia, Sara; Bollettini, Irene; Locatelli, Clara; Poletti, Sara; Colombo, Cristina

    2017-08-15

    Alteration of circadian rhythms and sleep disruption are prominent trait-like features of bipolar disorder (BD). Diffusion tensor imaging (DTI) measures suggest a widespread alteration of white matter (WM) microstructure in patients with BD. Sleep promotes myelination and oligodendrocyte precursor cells proliferation. We hypothesized a possible association between DTI measures of WM microstructure and sleep quantity measures in BD. We studied 69 inpatients affected by a depressive episode in course of type I BD. We used whole brain tract-based spatial statistics on DTI measures of WM microstructure: axial, radial, and mean diffusivity (AD, RD, MD), and fractional anisotropy (FA). Self-assessed measures of time asleep (TA) and total sleep time (TST) were extracted from the Pittsburgh Sleep Quality Index (PSQI). Actigraphic recordings were performed on a subsample of 23 patients. We observed a positive correlation of DTI measures of FA with actigraphic measures of TA and TST, and with PSQI measure of TA. DTI measures of RD inversely associated with actigraphic measure of TA, and with PSQI measures of TA and TST. Several WM tracts were involved, including corpus callosum, cyngulate gyrus, uncinate fasciculus, left superior and inferior longitudinal and fronto-occipital fasciculi, thalamic radiation, corona radiata, retrolenticular part of internal capsule and corticospinal tract. The study is correlational in nature, and no conclusion about a causal connection can be drawn. Reduced FA with increased RD and MD indicate higher water diffusivity associated with less organized myelin and/or axonal structures. Our findings suggest an association between sleep disruption and these measures of brain microstructure in specific tracts contributing to the functional connectivity in BD. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Quark matter

    Energy Technology Data Exchange (ETDEWEB)

    Csernai, L.; Kampert, K. H.

    1994-10-15

    Precisely one decade ago the GSI (Darmstadt)/LBL (Berkeley) Collaboration at the Berkeley Bevalac reported clear evidence for collective sidewards flow in high energy heavy ion collisions. This milestone observation clearly displayed the compression and heating up of nuclear matter, providing new insights into how the behaviour of nuclear matter changes under very different conditions. This year, evidence for azimuthally asymmetric transverse flow at ten times higher projectile energy (11 GeV per nucleon gold on gold collisions) was presented by the Brookhaven E877 collaboration at the recent European Research Conference on ''Physics of High Energy Heavy Ion Collisions'', held in Helsinki from 17-22 June.

  2. Economic integration in the Americas

    OpenAIRE

    Uitdewilligen, G.

    1997-01-01

    This pioneering study shows that economic integration in the Americas is not simply a matter of removing trade barriers. Economic Integration in the Americas addresses the pervasive effects of economic integration on the economy as a whole.

  3. Dark Matter

    Indian Academy of Sciences (India)

    As if this was not enough, it turns out that if our knowledge of ... are thought to contain dark matter, although the evidences from them are the .... protons, electrons, neutrons ... ratio of protons to neutrons was close to unity then as they were in ...

  4. Quantum matter

    International Nuclear Information System (INIS)

    Buechler, Hans Peter; Calcarco, Tommaso; Dressel, Martin

    2008-01-01

    The following topics are dealt with: Artificial atoms and molecules, tailored from solids, fractional flux quanta, molecular magnets, controlled interaction in quantum gases, the theory of quantum correlations in mott matter, cold gases, and mesoscopic systems, Bose-Einstein condensates on the chip, on the route to the quantum computer, a quantum computer in diamond. (HSI)

  5. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 4. Molecule Matters – van der Waals Molecules - History and Some Perspectives on Intermolecular Forces. E Arunan. Feature Article Volume 14 Issue 4 April 2009 pp 346-356 ...

  6. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 12. Molecule Matters - Dinitrogen. A G Samuelson J Jabadurai. Volume 16 Issue 12 ... Author Affiliations. A G Samuelson1 J Jabadurai1. Department of Inroganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012, India.

  7. Interstellar matter

    International Nuclear Information System (INIS)

    Mezger, P.G.

    1978-01-01

    An overview of the formation of our galaxy is presented followed by a summary of recent work in star formation and related topics. Selected discussions are given on interstellar matter including absorption characteristics of dust, the fully ionised component of the ISM and the energy density of lyc-photons in the solar neighbourhood and the diffuse galactic IR radiation

  8. Dark Matter

    Indian Academy of Sciences (India)

    The study of gas clouds orbiting in the outer regions of spiral galaxies has revealed that their gravitational at- traction is much larger than the stars alone can provide. Over the last twenty years, astronomers have been forced to postulate the presence of large quantities of 'dark matter' to explain their observations. They are ...

  9. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 9. Molecule Matters - A Chromium Compound with a Quintuple Bond. K C Kumara Swamy. Feature Article Volume 11 Issue 9 September 2006 pp 72-75. Fulltext. Click here to view fulltext PDF. Permanent link:

  10. Magnetic resonance fiber density mapping of age-related white matter changes

    International Nuclear Information System (INIS)

    Stadlbauer, Andreas; Ganslandt, Oliver; Salomonowitz, Erich; Buchfelder, Michael; Hammen, Thilo; Bachmair, Johanna; Eberhardt, Knut

    2012-01-01

    Objectives: To introduce fiber density mapping (FDM) for investigation of age-related white matter (WM) changes and to compare its capabilities with conventional diffusion tensor imaging (DTI) post-processing. Methods: DTI data with 1.9 mm 3 isotropic voxels were acquired from 44 healthy volunteers (18–88 years) at 3 T. FDM is a 3-step approach which includes diagonalization of the diffusion tensor, fiber reconstruction for the whole brain, and calculation of fiber density (FD) values. Maps of fractional anisotropy (FA) and mean diffusivity (MD) were additionally calculated. Voxel-based analyses were performed to determine volume clusters of significant correlation with age. Bivariate linear regression models and Hotelling–Williams tests were used to detect significant differences between correlations. Results: FDM detected a larger WM volume affected by age-related changes concomitant with fewer significant clusters compared to FA and MD. This indicates that WM alterations due to normal aging occur rather globally than locally. FD values showed a significant stronger correlation with age in frontal lobes (prefrontal and precentral gyrus), limbic lobes (cingulate and parahippocampal gyrus), the corpus callosum (genu) and temporal lobes. Conclusions: FDM shows higher sensitivity for detection of age-related WM changes because it includes all surrounding fiber structures into the evaluation of each DTI data voxel.

  11. White Matter Structural Differences in Young Children With Type 1 Diabetes: A Diffusion Tensor Imaging Study

    Science.gov (United States)

    Aye, Tandy; Barnea-Goraly, Naama; Ambler, Christian; Hoang, Sherry; Schleifer, Kristin; Park, Yaena; Drobny, Jessica; Wilson, Darrell M.; Reiss, Allan L.; Buckingham, Bruce A.

    2012-01-01

    OBJECTIVE To detect clinical correlates of cognitive abilities and white matter (WM) microstructural changes using diffusion tensor imaging (DTI) in young children with type 1 diabetes. RESEARCH DESIGN AND METHODS Children, ages 3 to <10 years, with type 1 diabetes (n = 22) and age- and sex-matched healthy control subjects (n = 14) completed neurocognitive testing and DTI scans. RESULTS Compared with healthy controls, children with type 1 diabetes had lower axial diffusivity (AD) values (P = 0.046) in the temporal and parietal lobe regions. There were no significant differences between groups in fractional anisotropy and radial diffusivity (RD). Within the diabetes group, there was a significant, positive correlation between time-weighted HbA1c and RD (P = 0.028). A higher, time-weighted HbA1c value was significantly correlated with lower overall intellectual functioning measured by the full-scale intelligence quotient (P = 0.03). CONCLUSIONS Children with type 1 diabetes had significantly different WM structure (as measured by AD) when compared with controls. In addition, WM structural differences (as measured by RD) were significantly correlated with their HbA1c values. Additional studies are needed to determine if WM microstructural differences in young children with type 1 diabetes predict future neurocognitive outcome. PMID:22966090

  12. Endothelial Function Is Associated with White Matter Microstructure and Executive Function in Older Adults

    Directory of Open Access Journals (Sweden)

    Nathan F. Johnson

    2017-08-01

    Full Text Available Age-related declines in endothelial function can lead to cognitive decline. However, little is known about the relationships between endothelial function and specific neurocognitive functions. This study explored the relationship between measures of endothelial function (reactive hyperemia index; RHI, white matter (WM health (fractional anisotropy, FA, and WM hyperintensity volume, WMH, and executive function (Trail Making Test (TMT; Trail B − Trail A. Participants were 36 older adults between the ages of 59 and 69 (mean age = 63.89 years, SD = 2.94. WMH volume showed no relationship with RHI or executive function. However, there was a positive relationship between RHI and FA in the genu and body of the corpus callosum. In addition, higher RHI and FA were each associated with better executive task performance. Tractography was used to localize the WM tracts associated with RHI to specific portions of cortex. Results indicated that the RHI-FA relationship observed in the corpus callosum primarily involved tracts interconnecting frontal regions, including the superior frontal gyrus (SFG and frontopolar cortex, linked with executive function. These findings suggest that superior endothelial function may help to attenuate age-related declines in WM microstructure in portions of the corpus callosum that interconnect prefrontal brain regions involved in executive function.

  13. A review of anisotropic conductivity models of brain white matter based on diffusion tensor imaging.

    Science.gov (United States)

    Wu, Zhanxiong; Liu, Yang; Hong, Ming; Yu, Xiaohui

    2018-06-01

    The conductivity of brain tissues is not only essential for electromagnetic source estimation (ESI), but also a key reflector of the brain functional changes. Different from the other brain tissues, the conductivity of whiter matter (WM) is highly anisotropic and a tensor is needed to describe it. The traditional electrical property imaging methods, such as electrical impedance tomography (EIT) and magnetic resonance electrical impedance tomography (MREIT), usually fail to image the anisotropic conductivity tensor of WM with high spatial resolution. The diffusion tensor imaging (DTI) is a newly developed technique that can fulfill this purpose. This paper reviews the existing anisotropic conductivity models of WM based on the DTI and discusses their advantages and disadvantages, as well as identifies opportunities for future research on this subject. It is crucial to obtain the linear conversion coefficient between the eigenvalues of anisotropic conductivity tensor and diffusion tensor, since they share the same eigenvectors. We conclude that the electrochemical model is suitable for ESI analysis because the conversion coefficient can be directly obtained from the concentration of ions in extracellular liquid and that the volume fraction model is appropriate to study the influence of WM structural changes on electrical conductivity. Graphical abstract ᅟ.

  14. Reliability of White Matter Microstructural Changes in HIV Infection: Metaanalysis and Confirmation

    Science.gov (United States)

    O’Connor, Erin E.; Jaillard, Assia; Renard, Felix; Zeffiro, Thomas A.

    2017-01-01

    Background Diffusion tensor imaging (DTI) has been widely used to measure HIV effects on white matter (WM) microarchitecture. While many have reported reduced fractional anisotropy (FA) and increased mean diffusivity (MD) in HIV, quantitative inconsistencies across studies are large. Purpose To evaluate the consistency across studies of HIV effects on DTI measures and then examine DTI reliability in a longitudinal seropositive cohort. Study Selection The meta-analysis included 16 cross-sectional studies reporting FA and 12 studies reporting MD in the corpus callosum. Data Analysis Random effects meta-analysis was used to estimate study standardized mean differences (smd) and heterogeneity. DTI longitudinal reliability was estimated in seropositives studied before, and three and six months after, beginning treatment. Data Synthesis Meta-analysis revealed lower FA (smd −0.43; psmd 0.44; p0.96. Limitation Many studies pooled participants with varying treatments, ages and disease durations. Conclusion HIV effects on WM microstructure exhibited substantial variations that could result from acquisition, processing or cohort selection differences. When acquisition parameters and processing were carefully controlled, the resulting DTI measures did not show high temporal variation. HIV effects on WM microstructure may be age dependent. The high longitudinal reliability of DTI WM microstructure measures make them promising disease activity markers. PMID:28596189

  15. Simultaneous Assessment of White Matter Changes in Microstructure and Connectedness in the Blind Brain

    Directory of Open Access Journals (Sweden)

    Nina Linde Reislev

    2016-01-01

    Full Text Available Magnetic resonance imaging (MRI of the human brain has provided converging evidence that visual deprivation induces regional changes in white matter (WM microstructure. It remains unclear how these changes modify network connections between brain regions. Here we used diffusion-weighted MRI to relate differences in microstructure and structural connectedness of WM in individuals with congenital or late-onset blindness relative to normally sighted controls. Diffusion tensor imaging (DTI provided voxel-specific microstructural features of the tissue, while anatomical connectivity mapping (ACM assessed the connectedness of each voxel with the rest of the brain. ACM yielded reduced anatomical connectivity in the corpus callosum in individuals with congenital but not late-onset blindness. ACM did not identify any brain region where blindness resulted in increased anatomical connectivity. DTI revealed widespread microstructural differences as indexed by a reduced regional fractional anisotropy (FA. Blind individuals showed lower FA in the primary visual and the ventral visual processing stream relative to sighted controls regardless of the blindness onset. The results show that visual deprivation shapes WM microstructure and anatomical connectivity, but these changes appear to be spatially dissociated as changes emerge in different WM tracts. They also indicate that regional differences in anatomical connectivity depend on the onset of blindness.

  16. Magnetic resonance fiber density mapping of age-related white matter changes

    Energy Technology Data Exchange (ETDEWEB)

    Stadlbauer, Andreas, E-mail: andi@nmr.at [MR Physics Group, Department of Radiology, Landesklinikum St. Poelten, Propst Fuehrer Strasse 4, A-3100 St. Poelten (Austria); Department of Neurosurgery, University of Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen (Germany); Ganslandt, Oliver [Department of Neurosurgery, University of Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen (Germany); Salomonowitz, Erich [MR Physics Group, Department of Radiology, Landesklinikum St. Poelten, Propst Fuehrer Strasse 4, A-3100 St. Poelten (Austria); Buchfelder, Michael [Department of Neurosurgery, University of Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen (Germany); Hammen, Thilo [Department of Neurology, Epilepsy Center, University of Erlangen-Nuremberg, Schwabachanlage 6, D-90429 Erlangen (Germany); Bachmair, Johanna [MR Physics Group, Department of Radiology, Landesklinikum St. Poelten, Propst Fuehrer Strasse 4, A-3100 St. Poelten (Austria); Eberhardt, Knut [Krankenhaus Schloss Werneck, MRT-Kompetenzzentrum, Balthasar-Neumann-Platz 1, D-97440 Werneck (Germany)

    2012-12-15

    Objectives: To introduce fiber density mapping (FDM) for investigation of age-related white matter (WM) changes and to compare its capabilities with conventional diffusion tensor imaging (DTI) post-processing. Methods: DTI data with 1.9 mm{sup 3} isotropic voxels were acquired from 44 healthy volunteers (18–88 years) at 3 T. FDM is a 3-step approach which includes diagonalization of the diffusion tensor, fiber reconstruction for the whole brain, and calculation of fiber density (FD) values. Maps of fractional anisotropy (FA) and mean diffusivity (MD) were additionally calculated. Voxel-based analyses were performed to determine volume clusters of significant correlation with age. Bivariate linear regression models and Hotelling–Williams tests were used to detect significant differences between correlations. Results: FDM detected a larger WM volume affected by age-related changes concomitant with fewer significant clusters compared to FA and MD. This indicates that WM alterations due to normal aging occur rather globally than locally. FD values showed a significant stronger correlation with age in frontal lobes (prefrontal and precentral gyrus), limbic lobes (cingulate and parahippocampal gyrus), the corpus callosum (genu) and temporal lobes. Conclusions: FDM shows higher sensitivity for detection of age-related WM changes because it includes all surrounding fiber structures into the evaluation of each DTI data voxel.

  17. Does white matter structure or hippocampal volume mediate associations between cortisol and cognitive ageing?

    Science.gov (United States)

    Cox, Simon R.; MacPherson, Sarah E.; Ferguson, Karen J.; Royle, Natalie A.; Maniega, Susana Muñoz; Hernández, Maria del C. Valdés; Bastin, Mark E.; MacLullich, Alasdair M.J.; Wardlaw, Joanna M.; Deary, Ian J.

    2015-01-01

    Elevated glucocorticoid (GC) levels putatively damage specific brain regions, which in turn may accelerate cognitive ageing. However, many studies are cross-sectional or have relatively short follow-up periods, making it difficult to relate GCs directly to changes in cognitive ability with increasing age. Moreover, studies combining endocrine, MRI and cognitive variables are scarce, measurement methods vary considerably, and formal tests of the underlying causal hypothesis (cortisol → brain → cognition) are absent. In this study, 90 men, aged 73 years, provided measures of fluid intelligence, processing speed and memory, diurnal and reactive salivary cortisol and two measures of white matter (WM) structure (WM hyperintensity volume from structural MRI and mean diffusivity averaged across 12 major tracts from diffusion tensor MRI), hippocampal volume, and also cognitive ability at age 11. We tested whether negative relationships between cognitive ageing differences (over more than 60 years) and salivary cortisol were significantly mediated by WM and hippocampal volume. Significant associations between reactive cortisol at 73 and cognitive ageing differences between 11 and 73 (r = −.28 to −.36, p cognition associations (cognitive ageing differences from childhood to the early 70s, partly via brain WM structure. PMID:26298692

  18. A reliable spatially normalized template of the human spinal cord--Applications to automated white matter/gray matter segmentation and tensor-based morphometry (TBM) mapping of gray matter alterations occurring with age.

    Science.gov (United States)

    Taso, Manuel; Le Troter, Arnaud; Sdika, Michaël; Cohen-Adad, Julien; Arnoux, Pierre-Jean; Guye, Maxime; Ranjeva, Jean-Philippe; Callot, Virginie

    2015-08-15

    Recently, a T2*-weighted template and probabilistic atlas of the white and gray matter (WM, GM) of the spinal cord (SC) have been reported. Such template can be used as tissue-priors for automated WM/GM segmentation but can also provide a common reference and normalized space for group studies. Here, a new template has been created (AMU40), and accuracy of automatic template-based WM/GM segmentation was quantified. The feasibility of tensor-based morphometry (TBM) for studying voxel-wise morphological differences of SC between young and elderly healthy volunteers was also investigated. Sixty-five healthy subjects were divided into young (n=40, age50years old, mean age 57±5years old) groups and scanned at 3T using an axial high-resolution T2*-weighted sequence. Inhomogeneity correction and affine intensity normalization of the SC and cerebrospinal fluid (CSF) signal intensities across slices were performed prior to both construction of the AMU40 template and WM/GM template-based segmentation. The segmentation was achieved using non-linear spatial normalization of T2*-w MR images to the AMU40 template. Validation of WM/GM segmentations was performed with a leave-one-out procedure by calculating DICE similarity coefficients between manual and automated WM/GM masks. SC morphological differences between young and elderly healthy volunteers were assessed using the same non-linear spatial normalization of the subjects' MRI to a common template, derivation of the Jacobian determinant maps from the warping fields, and a TBM analysis. Results demonstrated robust WM/GM automated segmentation, with mean DICE values greater than 0.8. Concerning the TBM analysis, an anterior GM atrophy was highlighted in elderly volunteers, demonstrating thereby, for the first time, the feasibility of studying local structural alterations in the SC using tensor-based morphometry. This holds great promise for studies of morphological impairment occurring in several central nervous system

  19. Whole brain analysis of postmortem density changes of grey and white matter on computed tomography by statistical parametric mapping

    Energy Technology Data Exchange (ETDEWEB)

    Nishiyama, Yuichi; Mori, Hiroshi; Katsube, Takashi; Kitagaki, Hajime [Shimane University Faculty of Medicine, Department of Radiology, Izumo-shi, Shimane (Japan); Kanayama, Hidekazu; Tada, Keiji; Yamamoto, Yasushi [Shimane University Hospital, Department of Radiology, Izumo-shi, Shimane (Japan); Takeshita, Haruo [Shimane University Faculty of Medicine, Department of Legal Medicine, Izumo-shi, Shimane (Japan); Kawakami, Kazunori [Fujifilm RI Pharma, Co., Ltd., Tokyo (Japan)

    2017-06-15

    This study examined the usefulness of statistical parametric mapping (SPM) for investigating postmortem changes on brain computed tomography (CT). This retrospective study included 128 patients (23 - 100 years old) without cerebral abnormalities who underwent unenhanced brain CT before and after death. The antemortem CT (AMCT) scans and postmortem CT (PMCT) scans were spatially normalized using our original brain CT template, and postmortem changes of CT values (in Hounsfield units; HU) were analysed by the SPM technique. Compared with AMCT scans, 58.6 % and 98.4 % of PMCT scans showed loss of the cerebral sulci and an unclear grey matter (GM)-white matter (WM) interface, respectively. SPM analysis revealed a significant decrease in cortical GM density within 70 min after death on PMCT scans, suggesting cytotoxic brain oedema. Furthermore, there was a significant increase in the density of the WM, lenticular nucleus and thalamus more than 120 min after death. The SPM technique demonstrated typical postmortem changes on brain CT scans, and revealed that the unclear GM-WM interface on early PMCT scans is caused by a rapid decrease in cortical GM density combined with a delayed increase in WM density. SPM may be useful for assessment of whole brain postmortem changes. (orig.)

  20. Whole brain analysis of postmortem density changes of grey and white matter on computed tomography by statistical parametric mapping

    International Nuclear Information System (INIS)

    Nishiyama, Yuichi; Mori, Hiroshi; Katsube, Takashi; Kitagaki, Hajime; Kanayama, Hidekazu; Tada, Keiji; Yamamoto, Yasushi; Takeshita, Haruo; Kawakami, Kazunori

    2017-01-01

    This study examined the usefulness of statistical parametric mapping (SPM) for investigating postmortem changes on brain computed tomography (CT). This retrospective study included 128 patients (23 - 100 years old) without cerebral abnormalities who underwent unenhanced brain CT before and after death. The antemortem CT (AMCT) scans and postmortem CT (PMCT) scans were spatially normalized using our original brain CT template, and postmortem changes of CT values (in Hounsfield units; HU) were analysed by the SPM technique. Compared with AMCT scans, 58.6 % and 98.4 % of PMCT scans showed loss of the cerebral sulci and an unclear grey matter (GM)-white matter (WM) interface, respectively. SPM analysis revealed a significant decrease in cortical GM density within 70 min after death on PMCT scans, suggesting cytotoxic brain oedema. Furthermore, there was a significant increase in the density of the WM, lenticular nucleus and thalamus more than 120 min after death. The SPM technique demonstrated typical postmortem changes on brain CT scans, and revealed that the unclear GM-WM interface on early PMCT scans is caused by a rapid decrease in cortical GM density combined with a delayed increase in WM density. SPM may be useful for assessment of whole brain postmortem changes. (orig.)

  1. Normalization of white matter intensity on T1-weighted images of patients with acquired central nervous system demyelination.

    Science.gov (United States)

    Ghassemi, Rezwan; Brown, Robert; Narayanan, Sridar; Banwell, Brenda; Nakamura, Kunio; Arnold, Douglas L

    2015-01-01

    Intensity variation between magnetic resonance images (MRI) hinders comparison of tissue intensity distributions in multicenter MRI studies of brain diseases. The available intensity normalization techniques generally work well in healthy subjects but not in the presence of pathologies that affect tissue intensity. One such disease is multiple sclerosis (MS), which is associated with lesions that prominently affect white matter (WM). To develop a T1-weighted (T1w) image intensity normalization method that is independent of WM intensity, and to quantitatively evaluate its performance. We calculated median intensity of grey matter and intraconal orbital fat on T1w images. Using these two reference tissue intensities we calculated a linear normalization function and applied this to the T1w images to produce normalized T1w (NT1) images. We assessed performance of our normalization method for interscanner, interprotocol, and longitudinal normalization variability, and calculated the utility of the normalization method for lesion analyses in clinical trials. Statistical modeling showed marked decreases in T1w intensity differences after normalization (P < .0001). We developed a WM-independent T1w MRI normalization method and tested its performance. This method is suitable for longitudinal multicenter clinical studies for the assessment of the recovery or progression of disease affecting WM. Copyright © 2014 by the American Society of Neuroimaging.

  2. Patient-specific 3D FLAIR for enhanced visualization of brain white matter lesions in multiple sclerosis.

    Science.gov (United States)

    Gabr, Refaat E; Pednekar, Amol S; Govindarajan, Koushik A; Sun, Xiaojun; Riascos, Roy F; Ramírez, María G; Hasan, Khader M; Lincoln, John A; Nelson, Flavia; Wolinsky, Jerry S; Narayana, Ponnada A

    2017-08-01

    To improve the conspicuity of white matter lesions (WMLs) in multiple sclerosis (MS) using patient-specific optimization of single-slab 3D fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI). Sixteen MS patients were enrolled in a prospective 3.0T MRI study. FLAIR inversion time and echo time were automatically optimized for each patient during the same scan session based on measurements of the relative proton density and relaxation times of the brain tissues. The optimization criterion was to maximize the contrast between gray matter (GM) and white matter (WM), while suppressing cerebrospinal fluid. This criterion also helps increase the contrast between WMLs and WM. The performance of the patient-specific 3D FLAIR protocol relative to the fixed-parameter protocol was assessed both qualitatively and quantitatively. Patient-specific optimization achieved a statistically significant 41% increase in the GM-WM contrast ratio (P < 0.05) and 32% increase in the WML-WM contrast ratio (P < 0.01) compared with fixed-parameter FLAIR. The increase in WML-WM contrast ratio correlated strongly with echo time (P < 10 -11 ). Two experienced neuroradiologists indicated substantially higher lesion conspicuity on the patient-specific FLAIR images over conventional FLAIR in 3-4 cases (intrarater correlation coefficient ICC = 0.72). In no case was the image quality of patient-specific FLAIR considered inferior to conventional FLAIR by any of the raters (ICC = 0.32). Changes in proton density and relaxation times render fixed-parameter FLAIR suboptimal in terms of lesion contrast. Patient-specific optimization of 3D FLAIR increases lesion conspicuity without scan time penalty, and has potential to enhance the detection of subtle and small lesions in MS. 1 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:557-564. © 2016 International Society for Magnetic Resonance in Medicine.

  3. Executive Functions in Healthy Older Adults Are Differentially Related to Macro- and Microstructural White Matter Characteristics of the Cerebral Lobes

    Directory of Open Access Journals (Sweden)

    Sarah Hirsiger

    2017-11-01

    Full Text Available Aging is associated with microstructural white matter (WM changes. WM microstructural characteristics, measured with diffusion tensor imaging (DTI, are different in normal appearing white matter (NAWM and WM hyperintensities (WMH. It is largely unknown how the microstructural properties of WMH are associated with cognition and if there are regional effects for specific cognitive domains. We therefore examined within 200 healthy older participants (a differences in microstructural characteristics of NAWM and WMH per cerebral lobe; and (b the association of macrostructural (WMH volume and microstructural characteristics (within NAWM and WMH separately of each lobe with measures of executive function and processing speed. Multi-modal imaging (i.e., T1, DTI, and FLAIR was used to assess WM properties. The Stroop and the Trail Making Test were used to measure inhibition, task-switching (both components of executive function, and processing speed. We observed that age was associated with deterioration of white matter microstructure of the NAWM, most notably in the frontal lobe. Older participants had larger WMH volumes and lowest fractional anisotropy values within WMH were found in the frontal lobe. Task-switching was associated with cerebral NAWM volume and NAWM volume of all lobes. Processing speed was associated with total NAWM volume, and microstructural properties of parietal NAWM, the parietal WMH, and the temporal NAWM. Task-switching was related to microstructural properties of WMH of the frontal lobe and WMH volume of the parietal lobe. Our results confirm that executive functioning and processing speed are uniquely associated with macro- and microstructural properties of NAWM and WMH. We further demonstrate for the first time that these relationships differ by lobar region. This warrants the consideration of these distinct WM indices when investigating cognitive function.

  4. Dark Matter

    International Nuclear Information System (INIS)

    Audouze, J.; Tran Thanh Van, J.

    1988-01-01

    The book begins with the papers devoted to the experimental search of signatures of the dark matter which governs the evolution of the Universe as a whole. A series of contributions describe the presently considered experimental techniques (cryogenic detectors, supraconducting detectors...). A real dialogue concerning these techniques has been instaured between particle physicists and astrophysicists. After the progress report of the particle physicists, the book provides the reader with an updated situation concerning the research in cosmology. The second part of the book is devoted to the analysis of the backgrounds at different energies such as the possible role of the cooling flows in the constitution of massive galactic halos. Any search of dark matter implies necessarily the analysis of the spatial distributions of the large scale structures of the Universe. This report is followed by a series of statistical analyses of these distributions. These analyses concern mainly universes filled up with cold dark matter. The last paper of this third part concerns the search of clustering in the spatial distribution of QSOs. The presence of dark matter should affect the solar neighborhood and related to the existence of galactic haloes. The contributions are devoted to the search of such local dark matter. Primordial nucleosynthesis provides a very powerful tool to set up quite constraining limitations on the overall baryonic density. Even if on takes into account the inhomogeneities in density possibly induced by the Quark-Hadron transition, this baryonic density should be much lower than the overall density deduced from the dynamical models of Universe or the inflationary theories

  5. Disposal Of Waste Matter

    International Nuclear Information System (INIS)

    Kim, Jeong Hyeon; Lee, Seung Mu

    1989-02-01

    This book deals with disposal of waste matter management of soiled waste matter in city with introduction, definition of waste matter, meaning of management of waste matter, management system of waste matter, current condition in the country, collect and transportation of waste matter disposal liquid waste matter, industrial waste matter like plastic, waste gas sludge, pulp and sulfuric acid, recycling technology of waste matter such as recycling system of Black clawson, Monroe and Rome.

  6. How Diversity Matters in the US Science and Engineering Workforce: A Critical Review Considering Integration in Teams, Fields, and Organizational Contexts

    Directory of Open Access Journals (Sweden)

    Laurel Smith-Doerr

    2017-04-01

    Full Text Available How the race and gender diversity of team members is related to innovative science and technology outcomes is debated in the scholarly literature. Some studies find diversity is linked to creativity and productivity, other studies find that diversity has no effect or even negative effects on team outcomes. Based on a critical review of the literature, this paper explains the seemingly contradictory findings through careful attention to the organizational contexts of team diversity. We distinguish between representational diversity and full integration of minority scientists. Representational diversity, where organizations have workforces that match the pool of degree recipients in relevant fields, is a necessary but not sufficient condition for diversity to yield benefits. Full integration of minority scientists (i.e., including women and people of color in an interaction context that allows for more level information exchange, unimpeded by the asymmetrical power relationships that are common across many scientific organizations, is when the full potential for diversity to have innovative outcomes is realized. Under conditions of equitable and integrated work environments, diversity leads to creativity, innovation, productivity, and positive reputational (status effects. Thus, effective policies for diversity in science and engineering must also address integration in the organizational contexts in which diverse teams are embedded.

  7. Exploring the Dynamic Relationship between the Accelerative Integrated Method (AIM) and the Core French Teachers Who Use It: Why Agency and Experience Matter

    Science.gov (United States)

    Arnott, Stephanie

    2011-01-01

    Over the last decade, almost 4,000 Canadian schools have moved to using the Accelerative Integrated Method (AIM) for core French (CF) instruction. Following researchers' recommendations (Brumfit, 1984; Lapkin, Mady, & Arnott, 2009; Larsen-Freeman, 1996, 2000; Prahbu, 1990), I am shifting the focus in this case study from product to process. In…

  8. Quark matter

    International Nuclear Information System (INIS)

    Csernai, L.; Kampert, K.H.

    1994-01-01

    Precisely one decade ago the GSI (Darmstadt)/LBL (Berkeley) Collaboration at the Berkeley Bevalac reported clear evidence for collective sidewards flow in high energy heavy ion collisions. This milestone observation clearly displayed the compression and heating up of nuclear matter, providing new insights into how the behaviour of nuclear matter changes under very different conditions. This year, evidence for azimuthally asymmetric transverse flow at ten times higher projectile energy (11 GeV per nucleon gold on gold collisions) was presented by the Brookhaven E877 collaboration at the recent European Research Conference on ''Physics of High Energy Heavy Ion Collisions'', held in Helsinki from 17-22 June

  9. Reduced binding of Pittsburgh Compound-B in areas of white matter hyperintensities

    Directory of Open Access Journals (Sweden)

    A.E. Goodheart

    2015-01-01

    Full Text Available The amyloid imaging agent, Pittsburgh Compound-B, binds with high affinity to β-amyloid (Aβ in the brain, and it is well established that PiB also shows non-specific retention in white matter (WM. However, little is known about retention of PiB in areas of white matter hyperintensities (WMH, abnormalities commonly seen in older adults. Further, it is hypothesized that WMH are related to both cognitive dysfunction and Aβ deposition. The goal of the present study was to explore PiB retention in both normal-appearing WM (NAWM and WMH in a group of elderly, cognitively normal individuals. In a group of cognitively normal elderly (n = 64; 86.5 ± 2.6 years two analyses were applied: (1 ROIs were placed over periventricular areas in which WMH caps are commonly seen on all subjects, regardless of WMH burden or size. (2 Subject-specific maps of NAWM and WMH were co-registered with the PiB-PET images and mean SUVR values were calculated in these NAWM and WMH maps. PiB retention was significantly reduced in the ROIs of subjects with high WMH compared to subjects with low WMH. Additionally, in subjects with high WMH, there was significantly lower PiB retention in subject-specific maps of WMH compared to NAWM, which was not observed in subjects with low WMH, likely because of the small size of WMH maps in this group. These data suggest that WM in areas of WMH binds PiB less effectively than does normal WM. Further exploration of this phenomenon may lead to insights about the molecular basis of the non-specific retention of amyloid tracers in white matter.

  10. Comorbidities, confounders, and the white matter transcriptome in chronic alcoholism.

    Science.gov (United States)

    Sutherland, Greg T; Sheedy, Donna; Sheahan, Pam J; Kaplan, Warren; Kril, Jillian J

    2014-04-01

    Alcohol abuse is the world's third leading cause of disease and disability, and one potential sequel of chronic abuse is alcohol-related brain damage (ARBD). This clinically manifests as cognitive dysfunction and pathologically as atrophy of white matter (WM) in particular. The mechanism linking chronic alcohol intoxication with ARBD remains largely unknown but it is also complicated by common comorbidities such as liver damage and nutritional deficiencies. Liver cirrhosis, in particular, often leads to hepatic encephalopathy (HE), a primary glial disease. In a novel transcriptomic study, we targeted the WM only of chronic alcoholics in an attempt to tease apart the pathogenesis of ARBD. Specifically, in alcoholics with and without HE, we explored both the prefrontal and primary motor cortices, 2 regions that experience differential levels of neuronal loss. Our results suggest that HE, along with 2 confounders, gray matter contamination, and low RNA quality are major drivers of gene expression in ARBD. All 3 exceeded the effects of alcohol itself. In particular, low-quality RNA samples were characterized by an up-regulation of translation machinery, while HE was associated with a down-regulation of mitochondrial energy metabolism pathways. The findings in HE alcoholics are consistent with the metabolic acidosis seen in this condition. In contrast non-HE alcoholics had widespread but only subtle changes in gene expression in their WM. Notwithstanding the latter result, this study demonstrates that significant confounders in transcriptomic studies of human postmortem brain tissue can be identified, quantified, and "removed" to reveal disease-specific signals. Copyright © 2014 by the Research Society on Alcoholism.

  11. Synchronous changes of cortical thickness and corresponding white matter microstructure during brain development accessed by diffusion MRI tractography from parcellated cortex

    Directory of Open Access Journals (Sweden)

    Tina eJeon

    2015-12-01

    Full Text Available Cortical thickness (CT changes during normal brain development is associated with complicated cellular and molecular processes including synaptic pruning and apoptosis. In parallel, the microstructural enhancement of developmental white matter (WM axons with their neuronal bodies in the cerebral cortex has been widely reported with measurements of metrics derived from diffusion tensor imaging (DTI, especially fractional anisotropy (FA. We hypothesized that the changes of CT and microstructural enhancement of corresponding axons are highly interacted during development. DTI and T1-weighted images of 50 healthy children and adolescents between the ages of 7 to 25 years were acquired. With the parcellated cortical gyri transformed from T1-weighted images to DTI space as the tractography seeds, probabilistic tracking was performed to delineate the WM fibers traced from specific parcellated cortical regions. CT was measured at certain cortical regions and FA was measured from the WM fibers traced from same cortical regions. The CT of all frontal cortical gyri, includeing Brodmann areas 4, 6, 8, 9, 10, 11, 44, 45, 46 and 47, decreased significantly and heterogeneously; concurrently, significant and heterogeneous increases of FA of WM traced from corresponding regions were found. We further revealed significant correlation between the slopes of the CT decrease and the slopes of corresponding WM FA increase in all frontal cortical gyri, suggesting coherent cortical pruning and corresponding WM microstructural enhancement. Such correlation was not found in cortical regions other than frontal cortex. The molecular and cellular mechanisms of these synchronous changes may be associated with overlapping signaling pathways of axonal guidance, synaptic pruning, neuronal apoptosis and more prevalent interstitial neurons in the prefrontal cortex. Revealing the coherence of cortical and WM structural changes during development may open a new window for

  12. Pathological Assessment of Brain White Matter in Relapsing-Remitting MS Patients using Quantitative Magnetization Transfer Imaging

    Directory of Open Access Journals (Sweden)

    Khodarahm Pahlevan

    2011-09-01

    Full Text Available Introduction: Multiple sclerosis (MS is characterized by lesions in the white matter (WM of the central nervous system. Magnetic resonance imaging is the most specific and sensitive method for diagnosis of multiple sclerosis. However, the ability of conventional MRI to show histopathologic heterogeneity of MS lesions is insufficient. Quantitative magnetization transfer imaging (qMTI is a relatively new method to investigate pathologic processes of the brain tissue occurring in MS patients. Material and Methods: Voxel-based analyses allow regional comparisons between groups to be made for the whole brain in a single analysis. This is done by coregistering data from all individual subjects to a reference brain, generally referred to as the "standard space", and then comparing them on a voxel-by-voxel basis. This study aimed to analyze whole-brain quantitative T1 maps, not to find global changes or changes in selected regions, but specifically to investigate the spatial distribution throughout the brain of T1 increases in MS WM with respect to control WM. In this study, 11 healthy controls, 10 relapsing-remitting (RR MS patients and 13 CIS patients were studied using MT-MRI imaging. MT parameters, including magnetization transfer ratio (MTR, magnetization transfer rate between free protons and restricted macromolecular protons, Ksat and longitudinal relaxation times (with and without MT saturation pulse, T1sat and T1free values were evaluated. Results: The results showed that, at a group level, there is widespread involvement of WM throughout the brain in CIS MS and especially in RRMS, where a significant T1 increase was found in 15.58% of WM voxels (normals < RR. Discussion and Conclusion: This study demonstrates that WM in large parts of the brain is susceptible to disease processes in RR and CIS MS

  13. Enlightening Students about Dark Matter

    Science.gov (United States)

    Hamilton, Kathleen; Barr, Alex; Eidelman, Dave

    2018-01-01

    Dark matter pervades the universe. While it is invisible to us, we can detect its influence on matter we can see. To illuminate this concept, we have created an interactive javascript program illustrating predictions made by six different models for dark matter distributions in galaxies. Students are able to match the predicted data with actual experimental results, drawn from several astronomy papers discussing dark matter’s impact on galactic rotation curves. Programming each new model requires integration of density equations with parameters determined by nonlinear curve-fitting using MATLAB scripts we developed. Using our javascript simulation, students can determine the most plausible dark matter models as well as the average percentage of dark matter lurking in galaxies, areas where the scientific community is still continuing to research. In that light, we strive to use the most up-to-date and accepted concepts: two of our dark matter models are the pseudo-isothermal halo and Navarro-Frenk-White, and we integrate out to each galaxy’s virial radius. Currently, our simulation includes NGC3198, NGC2403, and our own Milky Way.

  14. White matter microstructural changes in adolescent anorexia nervosa including an exploratory longitudinal study

    Science.gov (United States)

    Vogel, Katja; Timmers, Inge; Kumar, Vinod; Nickl-Jockschat, Thomas; Bastiani, Matteo; Roebroek, Alard; Herpertz-Dahlmann, Beate; Konrad, Kerstin; Goebel, Rainer; Seitz, Jochen

    2016-01-01

    Background Anorexia nervosa (AN) often begins in adolescence, however, the understanding of the underlying pathophysiology at this developmentally important age is scarce, impeding early interventions. We used diffusion tensor imaging (DTI) to investigate microstructural white matter (WM) brain changes including an experimental longitudinal follow-up. Methods We acquired whole brain diffusion-weighted brain scans of 22 adolescent female hospitalized patients with AN at admission and nine patients longitudinally at discharge after weight rehabilitation. Patients (10–18 years) were compared to 21 typically developing controls (TD). Tract-based spatial statistics (TBSS) were applied to compare fractional anisotropy (FA) across groups and time points. Associations between average FA values of the global WM skeleton and weight as well as illness duration parameters were analyzed by multiple linear regression. Results We observed increased FA in bilateral frontal, parietal and temporal areas in AN patients at admission compared to TD. Higher FA of the global WM skeleton at admission was associated with faster weight loss prior to admission. Exploratory longitudinal analysis showed this FA increase to be partially normalized after weight rehabilitation. Conclusions Our findings reveal a markedly different pattern of WM microstructural changes in adolescent AN compared to most previous results in adult AN. This could signify a different susceptibility and reaction to semi-starvation in the still developing brain of adolescents or a time-dependent pathomechanism differing with extend of chronicity. Higher FA at admission in adolescents with AN could point to WM fibers being packed together more closely. PMID:27182488

  15. White matter microstructural abnormalities in the frontal lobe of adults with antisocial personality disorder.

    Science.gov (United States)

    Sundram, Frederick; Deeley, Quinton; Sarkar, Sagari; Daly, Eileen; Latham, Richard; Craig, Michael; Raczek, Malgorzata; Fahy, Tom; Picchioni, Marco; Barker, Gareth J; Murphy, Declan G M

    2012-02-01

    Antisocial personality disorder (ASPD) and psychopathy involve significant interpersonal and behavioural impairments. However, little is known about their underlying neurobiology and in particular, abnormalities in white matter (WM) microstructure. A preliminary diffusion tensor magnetic resonance imaging (DT-MRI) study of adult psychopaths employing tractography revealed abnormalities in the right uncinate fasciculus (UF) (Craig et al., 2009), indicating fronto-limbic disconnectivity. However, it is not clear whether WM abnormalities are restricted to this tract or are or more widespread, including other tracts which are involved in connectivity with the frontal lobe. We performed whole brain voxel-based analyses on WM fractional anisotropy (FA) and mean diffusivity (MD) maps acquired with DT-MRI to compare 15 adults with ASPD and healthy age, handedness and IQ-matched controls. Also, within ASPD subjects we related differences in FA and MD to measures of psychopathy. Significant WM FA reduction and MD increases were found respectively in ASPD subjects relative to controls. FA was bilaterally reduced in the genu of corpus callosum while in the right frontal lobe FA reduction was found in the UF, inferior fronto-occipital fasciculus (IFOF), anterior corona radiata and anterior limb and genu of the internal capsule. These differences negatively correlated with measures of psychopathy. Also in the right frontal lobe, increased MD was found in the IFOF and UF, and the corpus callosum and anterior corona radiata. There was a significant positive correlation between MD and psychopathy scores. The present study confirms a previous report of reduced FA in the UF. Additionally, we report for the first time, FA deficits in tracts involved in interhemispheric as well as frontal lobe connectivity in conjunction with MD increases in the frontal lobe. Hence, we provide evidence of significant WM microstructural abnormalities in frontal brain regions in ASPD and psychopathy

  16. The effects of mild germinal matrix-intraventricular haemorrhage on the developmental white matter microstructure of preterm neonates. A DTI study

    International Nuclear Information System (INIS)

    Tortora, Domenico; Martinetti, Carola; Severino, Mariasavina; Morana, Giovanni; Rossi, Andrea; Uccella, Sara; Brera, Fabia; Malova, Mariya; Parodi, Alessandro; Ramenghi, Luca Antonio

    2018-01-01

    To evaluate white matter (WM) microstructural changes in preterm neonates (PN) with mild germinal matrix-intraventricular haemorrhage (mGMH-IVH) (grades I and II) and no other associated MRI abnormalities, and correlate them with gestational age (GA) and neurodevelopmental outcome. Tract-based spatial-statistics (TBSS) was performed on DTI of 103 patients studied at term-equivalent age, to compare diffusional parameters (fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD)) between mGMH-IVH neonates (24/103) and controls matched by GA at birth and sex. The relationship between DTI abnormalities, GA and neurodevelopmental outcome assessed with Griffiths' Developmental Scale-Revised:0-2 was explored using TBSS and Spearman-correlation analysis (p <.05). Affected neonates had lower FA, higher RD and MD of the corpus callosum, limbic pathways and cerebellar tracts. Extremely preterm neonates (GA < 29 weeks) presented more severe microstructural impairment (higher RD and MD) in periventricular regions. Neonates of GA ≥ 29 weeks had milder WM alterations (lower FA), also in subcortical WM. DTI abnormalities were associated with poorer locomotor, eye-hand coordination and performance outcomes at 24 months. WM microstructural changes occur in PN with mGMH-IVH with a GA-dependent selective vulnerability of WM regions, and correlate with adverse neurodevelopmental outcome at 24 months. (orig.)

  17. The effects of mild germinal matrix-intraventricular haemorrhage on the developmental white matter microstructure of preterm neonates. A DTI study

    Energy Technology Data Exchange (ETDEWEB)

    Tortora, Domenico; Martinetti, Carola; Severino, Mariasavina; Morana, Giovanni; Rossi, Andrea [Istituto Giannina Gaslini, Neuroradiology Unit, Genoa (Italy); Uccella, Sara; Brera, Fabia [Istituto Giannina Gaslini, Neuropsychiatry Unit, Genoa (Italy); Malova, Mariya; Parodi, Alessandro; Ramenghi, Luca Antonio [Istituto Giannina Gaslini, Neonatal Intensive Care Unit, Genoa (Italy)

    2018-03-15

    To evaluate white matter (WM) microstructural changes in preterm neonates (PN) with mild germinal matrix-intraventricular haemorrhage (mGMH-IVH) (grades I and II) and no other associated MRI abnormalities, and correlate them with gestational age (GA) and neurodevelopmental outcome. Tract-based spatial-statistics (TBSS) was performed on DTI of 103 patients studied at term-equivalent age, to compare diffusional parameters (fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD)) between mGMH-IVH neonates (24/103) and controls matched by GA at birth and sex. The relationship between DTI abnormalities, GA and neurodevelopmental outcome assessed with Griffiths' Developmental Scale-Revised:0-2 was explored using TBSS and Spearman-correlation analysis (p <.05). Affected neonates had lower FA, higher RD and MD of the corpus callosum, limbic pathways and cerebellar tracts. Extremely preterm neonates (GA < 29 weeks) presented more severe microstructural impairment (higher RD and MD) in periventricular regions. Neonates of GA ≥ 29 weeks had milder WM alterations (lower FA), also in subcortical WM. DTI abnormalities were associated with poorer locomotor, eye-hand coordination and performance outcomes at 24 months. WM microstructural changes occur in PN with mGMH-IVH with a GA-dependent selective vulnerability of WM regions, and correlate with adverse neurodevelopmental outcome at 24 months. (orig.)

  18. Play Matters

    DEFF Research Database (Denmark)

    Sicart (Vila), Miguel Angel

    ? In Play Matters, Miguel Sicart argues that to play is to be in the world; playing is a form of understanding what surrounds us and a way of engaging with others. Play goes beyond games; it is a mode of being human. We play games, but we also play with toys, on playgrounds, with technologies and design......, but not necessarily fun. Play can be dangerous, addictive, and destructive. Along the way, Sicart considers playfulness, the capacity to use play outside the context of play; toys, the materialization of play--instruments but also play pals; playgrounds, play spaces that enable all kinds of play; beauty...

  19. Span of control matters.

    Science.gov (United States)

    Cathcart, Deb; Jeska, Susan; Karnas, Joan; Miller, Sue E; Pechacek, Judy; Rheault, Lolita

    2004-09-01

    Prompted by manager concerns about span of control, a large, integrated health system set out to determine if span of control really mattered. Was there something to it, or was it just an excuse for poor performance? A team of middle managers studied the problem and ultimately demonstrated a strong relationship between span of control and employee engagement. Consequently, it was decided to add 4 management positions to note the effect. One year later, positive changes were observed in employee engagement scores in all 4 areas. This study suggests careful review of manager spans of control to address the untoward effects of large spans of control on employee engagement.

  20. Diffuse periventricular leukomalacia in preterm children: assessment of grey matter changes by MRI

    International Nuclear Information System (INIS)

    Tzarouchi, L.C.; Xydis, V.; Zikou, A.K.; Papastefanaki, M.; Argyropoulou, Maria I.; Drougia, A.; Andronikou, S.; Astrakas, L.G.

    2011-01-01

    Preterm children may have cognitive deficits and behavioural disorders suggestive of grey matter (GM) injury. The prevalence is higher in preterm children with diffuse periventricular leukomalacia (dPVL). Evaluate changes in the volume of 116 GM areas in preterm children with dPVL. Eleven preterm children with dPVL, gestational age 32.8 ± 2.6 weeks, examined at corrected age 22.0 ± 18.2 months and 33 matched preterm controls with normal brain MRI were studied. Volumes of 116 individual GM areas, and white matter/cerebrospinal fluid (WM/CSF) ratio were calculated on T1-weighted high-resolution images after segmentation. Relative to controls, children with dPVL had decreased GM volume of the hippocampus, amygdala, and frontal lobes and temporal middle gyrus (P < 0.05); increased GM volume of the putamen, thalamus, globus pallidum, superior temporal gyrus and of the parietal and occipital lobes (P < 0.05) and lower WM volume/higher CSF volume (P < 0.05). WM/CSF ratios also differed (P < 0.05). Preterm children with dPVL have increased regional GM volume in some areas probably related with a process of brain plasticity-regeneration and reduced GM volume in areas associated with cognition and memory. (orig.)

  1. Diffuse periventricular leukomalacia in preterm children: assessment of grey matter changes by MRI

    Energy Technology Data Exchange (ETDEWEB)

    Tzarouchi, L.C.; Xydis, V.; Zikou, A.K.; Papastefanaki, M.; Argyropoulou, Maria I. [University of Ioannina, Department of Radiology, Medical School, Ioannina (Greece); Drougia, A.; Andronikou, S. [University of Ioannina, Neonatal Intensive Care Unit, Child Health Department, Medical School, Ioannina (Greece); Astrakas, L.G. [University of Ioannina, Department of Medical Physics, Medical School, Ioannina (Greece)

    2011-12-15

    Preterm children may have cognitive deficits and behavioural disorders suggestive of grey matter (GM) injury. The prevalence is higher in preterm children with diffuse periventricular leukomalacia (dPVL). Evaluate changes in the volume of 116 GM areas in preterm children with dPVL. Eleven preterm children with dPVL, gestational age 32.8 {+-} 2.6 weeks, examined at corrected age 22.0 {+-} 18.2 months and 33 matched preterm controls with normal brain MRI were studied. Volumes of 116 individual GM areas, and white matter/cerebrospinal fluid (WM/CSF) ratio were calculated on T1-weighted high-resolution images after segmentation. Relative to controls, children with dPVL had decreased GM volume of the hippocampus, amygdala, and frontal lobes and temporal middle gyrus (P < 0.05); increased GM volume of the putamen, thalamus, globus pallidum, superior temporal gyrus and of the parietal and occipital lobes (P < 0.05) and lower WM volume/higher CSF volume (P < 0.05). WM/CSF ratios also differed (P < 0.05). Preterm children with dPVL have increased regional GM volume in some areas probably related with a process of brain plasticity-regeneration and reduced GM volume in areas associated with cognition and memory. (orig.)

  2. Cre-expressing neurons in the cortical white matter of Ntsr1-Cre GN220 mice.

    Science.gov (United States)

    Sundberg, Sofie C; Granseth, Björn

    2018-03-23

    Genetically modified mouse strains that express Cre-recombinase in specific neuronal sub-populations have become widely used tools for investigating neuronal function. The Ntsr1-Cre GN220 mouse expresses this enzyme in corticothalamic neurons in layer 6 of cerebral cortex. We observed that about 7% of Cre-expressing cells in the primary visual cortex are found within the white matter bordering layer 6. By using the immunohistochemical marker for layer 6 neurons, Forkhead box protein 2 (FoxP2), and fluorescently conjugated latex beads injected into the dorsal lateral geniculate nucleus, we show that about half of these cells are similar to and could belong to the layer 6 corticothalamic neuron population. The other half seems to be a distinct white matter (WM) neuron sub-population that we estimate to constitute 2-4% of the total cortical Cre-expressing population. Staining for the neuronal marker Neuronal nuclei (NeuN) revealed that about 15-40% of WM neurons are Cre-expressing. Thus, the potential contribution from WM neurons needs to be considered when interpreting the results from experiments using the Ntsr1-Cre GN220 mouse for investigating corticothalamic neuronal function. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Mobile air quality studies (MAQS in inner cities: particulate matter PM10 levels related to different vehicle driving modes and integration of data into a geographical information program

    Directory of Open Access Journals (Sweden)

    Uibel Stefanie

    2012-10-01

    Full Text Available Abstract Background Particulate matter (PM is assumed to exert a major burden on public health. Most studies that address levels of PM use stationary measure systems. By contrast, only few studies measure PM concentrations under mobile conditions to analyze individual exposure situations. Methods By combining spatial-temporal analysis with a novel vehicle-mounted sensor system, the present Mobile Air Quality Study (MAQS aimed to analyse effects of different driving conditions in a convertible vehicle. PM10 was continuously monitored in a convertible car, driven with roof open, roof closed, but windows open, or windows closed. Results PM10 values inside the car were nearly always higher with open roof than with roof and windows closed, whereas no difference was seen with open or closed windows. During the day PM10 values varied with high values before noon, and occasional high median values or standard deviation values due to individual factors. Vehicle speed in itself did not influence the mean value of PM10; however, at traffic speed (10 – 50 km/h the standard deviation was large. No systematic difference was seen between PM10 values in stationary and mobile cars, nor was any PM10 difference observed between driving within or outside an environmental (low emission zone. Conclusions The present study has shown the feasibility of mobile PM analysis in vehicles. Individual exposure of the occupants varies depending on factors like time of day as well as ventilation of the car; other specific factors are clearly identifiably and may relate to specific PM10 sources. This system may be used to monitor individual exposure ranges and provide recommendations for preventive measurements. Although differences in PM10 levels were found under certain ventilation conditions, these differences are likely not of concern for the safety and health of passengers.

  4. Detection of monohydroxylated polycyclic aromatic hydrocarbons in urine and particulate matter using LC separations coupled with integrated SPE and fluorescence detection or coupled with high-resolution time-of-flight mass spectrometry.

    Science.gov (United States)

    Lintelmann, Jutta; Wu, Xiao; Kuhn, Evelyn; Ritter, Sebastian; Schmidt, Claudia; Zimmermann, Ralf

    2018-05-01

    A high-performance liquid chromatographic (HPLC) method with integrated solid-phase extraction for the determination of 1-hydroxypyrene and 1-, 2-, 3-, 4- and 9-hydroxyphenanthrene in urine was developed and validated. After enzymatic treatment and centrifugation of 500 μL urine, 100 μL of the sample was directly injected into the HPLC system. Integrated solid-phase extraction was performed on a selective, copper phthalocyanine modified packing material. Subsequent chromatographic separation was achieved on a pentafluorophenyl core-shell column using a methanol gradient. For quantification, time-programmed fluorescence detection was used. Matrix-dependent recoveries were between 94.8 and 102.4%, repeatability and reproducibility ranged from 2.2 to 17.9% and detection limits lay between 2.6 and 13.6 ng/L urine. A set of 16 samples from normally exposed adults was analyzed using this HPLC-fluorescence detection method. Results were comparable with those reported in other studies. The chromatographic separation of the method was transferred to an ultra-high-performance liquid chromatography pentafluorophenyl core-shell column and coupled to a high-resolution time-of-flight mass spectrometer (HR-TOF-MS). The resulting method was used to demonstrate the applicability of LC-HR-TOF-MS for simultaneous target and suspect screening of monohydroxylated polycyclic aromatic hydrocarbons in extracts of urine and particulate matter. Copyright © 2018 John Wiley & Sons, Ltd.

  5. Abnormalities in gray and white matter volumes associated with explicit memory dysfunction in patients with generalized anxiety disorder.

    Science.gov (United States)

    Moon, Chung-Man; Jeong, Gwang-Woo

    2017-03-01

    Background The neuroanatomical abnormalities associated with behavioral dysfunction on explicit memory in patients generalized anxiety disorder (GAD) have not yet been clearly identified. Purpose To investigate the regional gray matter (GM) and white matter (WM) volume alterations over the whole brain in patients with GAD, as well as the correlation between the brain structural abnormality and explicit memory dysfunction. Material and Methods Twenty patients with GAD and 20 healthy controls matched for age, sex, and education level underwent high-resolution T1-weighted magnetic resonance imaging (MRI). The participants performed the explicit memory tasks with the neutral and anxiety-inducing words. Results Patients with GAD showed significantly reduced GM volumes in the midbrain (MB), thalamus, hippocampus (Hip), insula, and superior temporal gyrus (STG); and reduced WM volumes in the MB, anterior limb of the internal capsule (ALIC), dorsolateral prefrontal cortex (DLPFC), and precentral gyrus (PrG). It is important to note that the GM volume of the Hip and the WM volume of the DLPFC were positively correlated with the recognition accuracy (%) in the explicit memory tasks with neutral and anxiety-inducing words, respectively. On the other hand, the WM volume of the PrG was negatively correlated with the reaction time in the same memory tasks. Conclusion This study demonstrated the regional volume changes on whole-brain GM and WM and the correlation between the brain structural alteration and explicit memory dysfunction in GAD patients. These findings would be helpful to understand the association between the brain structure abnormality and the functional deficit in the explicit memory in GAD.

  6. Diffusion tractography and graph theory analysis reveal the disrupted rich-club organization of white matter structural networks in early Tourette Syndrome children

    Science.gov (United States)

    Wen, Hongwei; Liu, Yue; Wang, Shengpei; Zhang, Jishui; Peng, Yun; He, Huiguang

    2017-03-01

    Tourette syndrome (TS) is a childhood-onset neurobehavioral disorder. At present, the topological disruptions of the whole brain white matter (WM) structural networks remain poorly understood in TS children. Considering the unique position of the topologically central role of densely interconnected brain hubs, namely the rich club regions, therefore, we aimed to investigate whether the rich club regions and their related connections would be particularly vulnerable in early TS children. In our study, we used diffusion tractography and graph theoretical analyses to explore the rich club structures in 44 TS children and 48 healthy children. The structural networks of TS children exhibited significantly increased normalized rich club coefficient, suggesting that TS is characterized by increased structural integrity of this centrally embedded rich club backbone, potentially resulting in increased global communication capacity. In addition, TS children showed a reorganization of rich club regions, as well as significantly increased density and decreased number in feeder connections. Furthermore, the increased rich club coefficients and feeder connections density of TS children were significantly positively correlated to tic severity, indicating that TS may be characterized by a selective alteration of the structural connectivity of the rich club regions, tending to have higher bridging with non-rich club regions, which may increase the integration among tic-related brain circuits with more excitability but less inhibition for information exchanges between highly centered brain regions and peripheral areas. In all, our results suggest the disrupted rich club organization in early TS children and provide structural insights into the brain networks.

  7. Hanford site ER and WM needs

    International Nuclear Information System (INIS)

    Hunter, J.R.

    1993-01-01

    This paper provides an overview of the environmental restoration and waste management needs of the Hanford site. Since 1944, waste has been put into cribs, tanks, or various kinds of burial grounds. The waste volume produced per ton of processed material has dramatically decreased over this time period, but the amount of waste is still very large. Initially high-level processing wastes were stored in 149 single-shell tanks (SSTs), with a single carbon steel shell, backed by concrete. By the late 1950's some of these tanks were leaking, and the supernate was removed from the tanks, leaving salt cake material. Double shell tanks, holding roughly 1 million gallons each, have replaced the single shell tanks (28 in total). Cribs were used early, as the soil column was found to be perfect for retaining certain radionuclides. Solid wastes include retrievably stored transuranic wastes, and wastes generated since 1970. Wastes and fuel assemblies from EBR-2 and FFTF are included. Some TRU wastes were packaged in 55 gal drums, and dumped. A number of sites and reactors are being decontaminated, including canyon type facilities, processing facilities, the B Plant, the REDOX, D Plant, C Plant, and PUREX Plant, not all of which were even flushed before being shut down

  8. Marginal Matter

    Science.gov (United States)

    van Hecke, Martin

    2013-03-01

    All around us, things are falling apart. The foam on our cappuccinos appears solid, but gentle stirring irreversibly changes its shape. Skin, a biological fiber network, is firm when you pinch it, but soft under light touch. Sand mimics a solid when we walk on the beach but a liquid when we pour it out of our shoes. Crucially, a marginal point separates the rigid or jammed state from the mechanical vacuum (freely flowing) state - at their marginal points, soft materials are neither solid nor liquid. Here I will show how the marginal point gives birth to a third sector of soft matter physics: intrinsically nonlinear mechanics. I will illustrate this with shock waves in weakly compressed granular media, the nonlinear rheology of foams, and the nonlinear mechanics of weakly connected elastic networks.

  9. Exploring the dynamic relationship between the Accelerative Integrated Method (AIM and the core French teachers who use it: Why agency and experience matter.

    Directory of Open Access Journals (Sweden)

    Stephanie Arnott

    2011-12-01

    Full Text Available Abstract Over the last decade, almost 4,000 Canadian schools have moved to using the Accelerative Integrated Method (AIM for core French (CF instruction. Following researchers’ recommendations (Brumfit, 1984; Lapkin, Mady, & Arnott, 2009; Larsen-Freeman, 1996, 2000; Prahbu, 1990, I am shifting the focus in this case study from product to process. In other words, investigating how AIM teachers use and shape the method during implementation instead of comparing AIM and non-AIM student outcomes (Bourdages & Vignola, 2009; Carr, 2001; Mady, Arnott, & Lapkin, 2009; Maxwell, 2001; Michels, 2008;. Four interviews and observation sessions were conducted with eight elementary-level CF teachers. Findings showed that while some AIM routines and strategies were used by all, teachers exercised their agency in supplementing recommended AIM activities and materials, especially those with more AIM and CF teaching experience. Establishing that using AIM engaged teachers’ senses of plausibility (Prahbu, 1990 also exposed important implications for future AIM research and board-level policy. Résumé Depuis les années 2000, plus de 4000 écoles canadiennes ont decidé d’utiliser une forme d’enseignement qui s’appelle AIM (Accelerative Integrated Method pour leurs programmes de français de base (Core French. Selon les recommandations des chercheurs suivants (Brumfit, 1984; Lapkin, Mady, & Arnott, 2009; Larsen-Freeman, 1996, 2000; Prahbu, 1990, au lieu d’étudier les résultats, l’objectif de cette étude de cas était d’examiner la mise en œuvre de AIM. Huit enseignants de français de base ont passé quatre entrevues individuelles. Ils ont eu quatre sessions d’observation de pratique de AIM . Selon les résultats, quoiqu’ils aient employé des stratégies et routines de AIM de la même façon, tous les enseignants ont aussi décidé d’ajouter leurs propres activités et ressources à AIM, surtout ceux experts dans l’enseignement du fran

  10. White and Gray Matter Abnormalities After Cranial Radiation in Children and Mice

    Energy Technology Data Exchange (ETDEWEB)

    Nieman, Brian J., E-mail: brian.nieman@utoronto.ca [Department of Physiology & Experimental Medicine, Hospital for Sick Children, Toronto, Ontario (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario (Canada); Ontario Institute for Cancer Research, Toronto, Ontario (Canada); Guzman, A. Elizabeth de [Department of Physiology & Experimental Medicine, Hospital for Sick Children, Toronto, Ontario (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario (Canada); Gazdzinski, Lisa M. [Department of Physiology & Experimental Medicine, Hospital for Sick Children, Toronto, Ontario (Canada); Lerch, Jason P. [Department of Neurosciences & Mental Health, Hospital for Sick Children, Toronto, Ontario (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario (Canada); Chakravarty, M. Mallar [Cerebral Imaging Centre, Douglas Mental Health University Institute, Montreal, Quebec (Canada); Departments of Psychiatry and Biomedical Engineering, McGill University, Montreal, Quebec (Canada); Pipitone, Jon [Kimel Family Translational Imaging Genetics Research Laboratory, Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario (Canada); Strother, Douglas [Alberta Children' s Hospital, Calgary, Alberta (Canada); Departments of Oncology and Pediatrics, University of Calgary, Calgary, Alberta (Canada); Fryer, Chris [Division of Oncology/Hematology/BMT British Columbia Children' s Hospital and British Columbia Women' s Hospital and Health Centre, Vancouver, British Columbia (Canada); Department of Pediatrics, University of British Columbia, Vancouver, British Columbia (Canada); Bouffet, Eric [Department of Physiology & Experimental Medicine, Hospital for Sick Children, Toronto, Ontario (Canada); Department of Paediatrics, University of Toronto, Toronto, Ontario (Canada); and others

    2015-11-15

    Purpose: Pediatric patients treated with cranial radiation are at high risk of developing lasting cognitive impairments. We sought to identify anatomical changes in both gray matter (GM) and white matter (WM) in radiation-treated patients and in mice, in which the effect of radiation can be isolated from other factors, the time course of anatomical change can be established, and the effect of treatment age can be more fully characterized. Anatomical results were compared between species. Methods and Materials: Patients were imaged with T{sub 1}-weighted magnetic resonance imaging (MRI) after radiation treatment. Nineteen radiation-treated patients were divided into groups of 7 years of age and younger (7−) and 8 years and older (8+) and were compared to 41 controls. C57BL6 mice were treated with radiation (n=52) or sham treated (n=52) between postnatal days 16 and 36 and then assessed with in vivo and/or ex vivo MRI. In both cases, measurements of WM and GM volume, cortical thickness, area and volume, and hippocampal volume were compared between groups. Results: WM volume was significantly decreased following treatment in 7− and 8+ treatment groups. GM volume was unchanged overall, but cortical thickness was slightly increased in the 7− group. Results in mice mostly mirrored these changes and provided a time course of change, showing early volume loss and normal growth. Hippocampal volume showed a decreasing trend with age in patients, an effect not observed in the mouse hippocampus but present in the olfactory bulb. Conclusions: Changes in mice treated with cranial radiation are similar to those in humans, including significant WM and GM alterations. Because mice did not receive any other treatment, the similarity across species supports the expectation that radiation is causative and suggests mice provide a representative model for studying impaired brain development after cranial radiation and testing novel treatments.

  11. White and Gray Matter Abnormalities After Cranial Radiation in Children and Mice

    International Nuclear Information System (INIS)

    Nieman, Brian J.; Guzman, A. Elizabeth de; Gazdzinski, Lisa M.; Lerch, Jason P.; Chakravarty, M. Mallar; Pipitone, Jon; Strother, Douglas; Fryer, Chris; Bouffet, Eric

    2015-01-01

    Purpose: Pediatric patients treated with cranial radiation are at high risk of developing lasting cognitive impairments. We sought to identify anatomical changes in both gray matter (GM) and white matter (WM) in radiation-treated patients and in mice, in which the effect of radiation can be isolated from other factors, the time course of anatomical change can be established, and the effect of treatment age can be more fully characterized. Anatomical results were compared between species. Methods and Materials: Patients were imaged with T_1-weighted magnetic resonance imaging (MRI) after radiation treatment. Nineteen radiation-treated patients were divided into groups of 7 years of age and younger (7−) and 8 years and older (8+) and were compared to 41 controls. C57BL6 mice were treated with radiation (n=52) or sham treated (n=52) between postnatal days 16 and 36 and then assessed with in vivo and/or ex vivo MRI. In both cases, measurements of WM and GM volume, cortical thickness, area and volume, and hippocampal volume were compared between groups. Results: WM volume was significantly decreased following treatment in 7− and 8+ treatment groups. GM volume was unchanged overall, but cortical thickness was slightly increased in the 7− group. Results in mice mostly mirrored these changes and provided a time course of change, showing early volume loss and normal growth. Hippocampal volume showed a decreasing trend with age in patients, an effect not observed in the mouse hippocampus but present in the olfactory bulb. Conclusions: Changes in mice treated with cranial radiation are similar to those in humans, including significant WM and GM alterations. Because mice did not receive any other treatment, the similarity across species supports the expectation that radiation is causative and suggests mice provide a representative model for studying impaired brain development after cranial radiation and testing novel treatments.

  12. Alterations in white matter volume and its correlation with clinical characteristics in patients with generalized anxiety disorder

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Chung-Man [Chonnam National University Hospital, Research Institute for Medical Imaging, Gwangju (Korea, Republic of); Jeong, Gwang-Woo [Chonnam National University Hospital, Research Institute for Medical Imaging, Gwangju (Korea, Republic of); Chonnam National University Medical School, Department of Radiology, Chonnam National University Hospital, Gwangju (Korea, Republic of)

    2015-11-15

    Only a few morphological studies have focused on changes in white matter (WM) volume in patients with generalized anxiety disorder (GAD). We evaluated alterations in WM volume and its correlation with symptom severity and duration of illness in adults with GAD. The 44 subjects were comprised of 22 patients with GAD (13 males and nine females) diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) and 22 age-matched healthy controls (13 males and nine females). High-resolution magnetic resonance imaging (MRI) data were processed by voxel-based morphometry (VBM) analysis based on diffeomorphic anatomical registration using the exponentiated Lie algebra (DARTEL) algorithm in SPM8. Patients with GAD showed significantly reduced WM volume, particularly in the dorsolateral prefrontal cortex (DLPFC), anterior limb of the internal capsule (ALIC), and midbrain. In addition, DLPFC volume was negatively correlated with GAD-7 score and illness duration. ALIC volume was negatively correlated with GAD-7 score. Female patients had significantly less orbitofrontal cortex volume compared to that in male patients. The findings demonstrate localized changes in WM volume associated with cognitive and emotional dysfunction in patients with GAD. The finding will be helpful for understanding the neuropathology in patients with GAD. (orig.)

  13. Alterations in white matter volume and its correlation with clinical characteristics in patients with generalized anxiety disorder

    International Nuclear Information System (INIS)

    Moon, Chung-Man; Jeong, Gwang-Woo

    2015-01-01

    Only a few morphological studies have focused on changes in white matter (WM) volume in patients with generalized anxiety disorder (GAD). We evaluated alterations in WM volume and its correlation with symptom severity and duration of illness in adults with GAD. The 44 subjects were comprised of 22 patients with GAD (13 males and nine females) diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) and 22 age-matched healthy controls (13 males and nine females). High-resolution magnetic resonance imaging (MRI) data were processed by voxel-based morphometry (VBM) analysis based on diffeomorphic anatomical registration using the exponentiated Lie algebra (DARTEL) algorithm in SPM8. Patients with GAD showed significantly reduced WM volume, particularly in the dorsolateral prefrontal cortex (DLPFC), anterior limb of the internal capsule (ALIC), and midbrain. In addition, DLPFC volume was negatively correlated with GAD-7 score and illness duration. ALIC volume was negatively correlated with GAD-7 score. Female patients had significantly less orbitofrontal cortex volume compared to that in male patients. The findings demonstrate localized changes in WM volume associated with cognitive and emotional dysfunction in patients with GAD. The finding will be helpful for understanding the neuropathology in patients with GAD. (orig.)

  14. Diffusion Tensor Imaging Tractography Reveals Disrupted White Matter Structural Connectivity Network in Healthy Adults with Insomnia Symptoms

    Directory of Open Access Journals (Sweden)

    Feng-Mei Lu

    2017-11-01

    Full Text Available Neuroimaging studies have revealed that insomnia is characterized by aberrant neuronal connectivity in specific brain regions, but the topological disruptions in the white matter (WM structural connectivity networks remain largely unknown in insomnia. The current study uses diffusion tensor imaging (DTI tractography to construct the WM structural networks and graph theory analysis to detect alterations of the brain structural networks. The study participants comprised 30 healthy subjects with insomnia symptoms (IS and 62 healthy subjects without IS. Both the two groups showed small-world properties regarding their WM structural connectivity networks. By contrast, increased local efficiency and decreased global efficiency were identified in the IS group, indicating an insomnia-related shift in topology away from regular networks. In addition, the IS group exhibited disrupted nodal topological characteristics in regions involving the fronto-limbic and the default-mode systems. To our knowledge, this is the first study to explore the topological organization of WM structural network connectivity in insomnia. More importantly, the dysfunctions of large-scale brain systems including the fronto-limbic pathways, salience network and default-mode network in insomnia were identified, which provides new insights into the insomnia connectome. Topology-based brain network analysis thus could be a potential biomarker for IS.

  15. Web-based modelling of energy, water and matter fluxes to support decision making in mesoscale catchments??the integrative perspective of GLOWA-Danube

    Science.gov (United States)

    Ludwig, R.; Mauser, W.; Niemeyer, S.; Colgan, A.; Stolz, R.; Escher-Vetter, H.; Kuhn, M.; Reichstein, M.; Tenhunen, J.; Kraus, A.; Ludwig, M.; Barth, M.; Hennicker, R.

    The GLOWA-initiative (Global Change of the water cycle), funded by the German Ministry of Research and Education (BMBF), has been established to address the manifold consequences of Global Change on regional water resources in a variety of catchment areas with different natural and cultural characteristics. Within this framework, the GLOWA-Danube project is dealing with the Upper Danube watershed as a representative mesoscale test site (∼75.000 km 2) for mountain-foreland regions in the temperate mid-latitudes. The principle objective is to identify, examine and develop new techniques of coupled distributed modelling for the integration of natural and socio-economic sciences. The transdisciplinary research in GLOWA-Danube develops an integrated decision support system, called DANUBIA, to investigate the sustainability of future water use. GLOWA-Danube, which is scheduled for a total run-time of eight years to operationally implement and establish DANUBIA, comprises a university-based network of experts with water-related competence in the fields of engineering, natural and social sciences. Co-operation with a network of stakeholders in water resources management of the Upper Danube catchment ensures that practical issues and future problems in the water sector of the region can be addressed. In order to synthesize a common understanding between the project partners, a standardized notation of parameters and functions and a platform-independent structure of computational methods and interfaces has been established, by making use of the unified modelling language, an industry standard for the structuring and co-ordination of large projects in software development [Booch et al., The Unified Modelling Language User Guide, Addison-Wesley, Reading, 1999]. DANUBIA is object-oriented, spatially distributed and raster-based at its core. It applies the concept of “proxels” (process pixels) as its basic objects, which have different dimensions depending on the viewing

  16. A 3D high resolution ex vivo white matter atlas of the common squirrel monkey (Saimiri sciureus) based on diffusion tensor imaging.

    Science.gov (United States)

    Gao, Yurui; Parvathaneni, Prasanna; Schilling, Kurt G; Wang, Feng; Stepniewska, Iwona; Xu, Zhoubing; Choe, Ann S; Ding, Zhaohua; Gore, John C; Chen, Li Min; Landman, Bennett A; Anderson, Adam W

    2016-02-27

    Modern magnetic resonance imaging (MRI) brain atlases are high quality 3-D volumes with specific structures labeled in the volume. Atlases are essential in providing a common space for interpretation of results across studies, for anatomical education, and providing quantitative image-based navigation. Extensive work has been devoted to atlas construction for humans, macaque, and several non-primate species (e.g., rat). One notable gap in the literature is the common squirrel monkey - for which the primary published atlases date from the 1960's. The common squirrel monkey has been used extensively as surrogate for humans in biomedical studies, given its anatomical neuro-system similarities and practical considerations. This work describes the continued development of a multi-modal MRI atlas for the common squirrel monkey, for which a structural imaging space and gray matter parcels have been previously constructed. This study adds white matter tracts to the atlas. The new atlas includes 49 white matter (WM) tracts, defined using diffusion tensor imaging (DTI) in three animals and combines these data to define the anatomical locations of these tracks in a standardized coordinate system compatible with previous development. An anatomist reviewed the resulting tracts and the inter-animal reproducibility (i.e., the Dice index of each WM parcel across animals in common space) was assessed. The Dice indices range from 0.05 to 0.80 due to differences of local registration quality and the variation of WM tract position across individuals. However, the combined WM labels from the 3 animals represent the general locations of WM parcels, adding basic connectivity information to the atlas.

  17. A 3D high resolution ex vivo white matter atlas of the common squirrel monkey (saimiri sciureus) based on diffusion tensor imaging

    Science.gov (United States)

    Gao, Yurui; Parvathaneni, Prasanna; Schilling, Kurt G.; Wang, Feng; Stepniewska, Iwona; Xu, Zhoubing; Choe, Ann S.; Ding, Zhaohua; Gore, John C.; Chen, Li min; Landman, Bennett A.; Anderson, Adam W.

    2016-03-01

    Modern magnetic resonance imaging (MRI) brain atlases are high quality 3-D volumes with specific structures labeled in the volume. Atlases are essential in providing a common space for interpretation of results across studies, for anatomical education, and providing quantitative image-based navigation. Extensive work has been devoted to atlas construction for humans, macaque, and several non-primate species (e.g., rat). One notable gap in the literature is the common squirrel monkey - for which the primary published atlases date from the 1960's. The common squirrel monkey has been used extensively as surrogate for humans in biomedical studies, given its anatomical neuro-system similarities and practical considerations. This work describes the continued development of a multi-modal MRI atlas for the common squirrel monkey, for which a structural imaging space and gray matter parcels have been previously constructed. This study adds white matter tracts to the atlas. The new atlas includes 49 white matter (WM) tracts, defined using diffusion tensor imaging (DTI) in three animals and combines these data to define the anatomical locations of these tracks in a standardized coordinate system compatible with previous development. An anatomist reviewed the resulting tracts and the inter-animal reproducibility (i.e., the Dice index of each WM parcel across animals in common space) was assessed. The Dice indices range from 0.05 to 0.80 due to differences of local registration quality and the variation of WM tract position across individuals. However, the combined WM labels from the 3 animals represent the general locations of WM parcels, adding basic connectivity information to the atlas.

  18. Light and heavy dark matter particles

    International Nuclear Information System (INIS)

    Boehm, C.; Fayet, P.; Silk, J.

    2004-01-01

    It has recently been pointed out that the 511 keV emission line detected by integral/SPI from the bulge of our galaxy could be explained by annihilations of light dark matter particles into e + e - . If such a signature is confirmed, then one might expect a conflict with the interpretation of very high energy gamma rays if they also turn out to be due to dark matter annihilations. Here, we propose a way to accommodate the existence of both signals being produced by dark matter annihilations through the existence of two stable (neutral) dark matter particles, as is possible in theories inspired from N=2 supersymmetry

  19. Baryonic matter and beyond

    OpenAIRE

    Fukushima, Kenji

    2014-01-01

    We summarize recent developments in identifying the ground state of dense baryonic matter and beyond. The topics include deconfinement from baryonic matter to quark matter, a diquark mixture, topological effect coupled with chirality and density, and inhomogeneous chiral condensates.

  20. Front Matter

    Directory of Open Access Journals (Sweden)

    HLRC Editor

    2016-08-01

    Full Text Available Higher Learning Research Communications (HLRC, ISSN: 2157-6254 [Online] is published collaboratively by Walden University (USA, Universidad Andrés Bello (Chile, Universidad Europea de Madrid (Spain and Istanbul Bilgi University (Turkey. Written communication to HLRC should be addressed to the office of the Executive Director at Laureate Education, Inc. 701 Brickell Ave Ste. 1700, Miami, FL 33131, USA. HLRC is designed for open access and online distribution through www.hlrcjournal.com. The views and statements expressed in this journal do not necessarily reflect the views of Laureate Education, Inc. or any of its affiliates (collectively “Laureate”. Laureate does not warrant the accuracy, reliability, currency or completeness of those views or statements and does not accept any legal liability arising from any reliance on the views, statements and subject matter of the journal. Acknowledgements The Guest Editors gratefully acknowledge the substantial contribution of the readers for the blind peer review of essays submitted for this special issue as exemplars of individuals from around the world who have come together in a collective endeavor for the common good: Robert Bringle (Indiana University Purdue University Indianapolis, US, Linda Buckley (University of the Pacific, US, Guillermo Calleja (Universidad Rey Juan Carlos, Spain, Eva Egron-Polak (International Association of Universities, France, Heather Friesen (Abu Dhabi University, UAE, Saran Gill (National University of Malaysia, Malaysia, Chester Haskell (higher education consultant, US, Kanokkarn Kaewnuch (National Institute for Development Administration, Thailand, Gil Latz (Indiana University Purdue University Indianapolis, US, Molly Lee (higher education consultant, Malaysia, Deane Neubauer (East-West Center at University of Hawaii, US, Susan Sutton (Bryn Mawr College, US, Francis Wambalaba (United States International University, Kenya, and Richard Winn (higher education

  1. Scale matters

    Science.gov (United States)

    Margolin, L. G.

    2018-04-01

    The applicability of Navier-Stokes equations is limited to near-equilibrium flows in which the gradients of density, velocity and energy are small. Here I propose an extension of the Chapman-Enskog approximation in which the velocity probability distribution function (PDF) is averaged in the coordinate phase space as well as the velocity phase space. I derive a PDF that depends on the gradients and represents a first-order generalization of local thermodynamic equilibrium. I then integrate this PDF to derive a hydrodynamic model. I discuss the properties of that model and its relation to the discrete equations of computational fluid dynamics. This article is part of the theme issue `Hilbert's sixth problem'.

  2. White matter disease correlates with lexical retrieval deficits in primary progressive aphasia.

    Science.gov (United States)

    Powers, John P; McMillan, Corey T; Brun, Caroline C; Yushkevich, Paul A; Zhang, Hui; Gee, James C; Grossman, Murray

    2013-01-01

    To relate fractional anisotropy (FA) changes associated with the semantic and logopenic variants of primary progressive aphasia (PPA) to measures of lexical retrieval. We collected neuropsychological testing, volumetric magnetic resonance imaging, and diffusion-weighted imaging on semantic variant PPA (svPPA) (n = 11) and logopenic variant PPA (lvPPA) (n = 13) patients diagnosed using published criteria. We also acquired neuroimaging data on a group of demographically comparable healthy seniors (n = 34). FA was calculated and analyzed using a white matter (WM) tract-specific analysis approach. This approach utilizes anatomically guided data reduction to increase sensitivity and localizes results within canonically defined tracts. We used non-parametric, cluster-based statistical analysis to relate language performance to FA and determine regions of reduced FA in patients. We found widespread FA reductions in WM for both variants of PPA. FA was related to both confrontation naming and category naming fluency performance in left uncinate fasciculus and corpus callosum in svPPA and left superior and inferior longitudinal fasciculi in lvPPA. SvPPA and lvPPA are associated with distinct disruptions of a large-scale network implicated in lexical retrieval, and the WM disease in each phenotype may contribute to language impairments including lexical retrieval.

  3. Intra- and interhemispheric variations of diffusivity in subcortical white matter in normal human brain

    International Nuclear Information System (INIS)

    Yoshiura, Takashi; Noguchi, Tomoyuki; Hiwatashi, Akio; Togao, Osamu; Yamashita, Koji; Nagao, Eiki; Kamano, Hironori; Honda, Hiroshi

    2010-01-01

    Our purpose was to reveal potential regional variations in water molecular diffusivity within each cerebral hemisphere and across the right and left hemispheres. Diffusion-weighted images of 44 healthy right-handed adult male subjects were obtained using a diffusion tensor imaging sequence. Mean diffusivity (MD) values in subcortical white matter (WM) within 39 regions in each hemisphere were measured using an automated method. Intrahemispheric comparisons of MDs in subcortical WM were performed among six brain regions (frontal, parietal, occipital and temporal lobes and pre- and postcentral gyri). Interhemispheric comparisons of MDs were performed between the right and left counterparts of the 39 regions. In both hemispheres, diffusivity in the precentral gyrus was lower than those in other regions, while diffusivity in the parietal lobe was higher than others. MD asymmetry in which the left was lower than the right was found in the parietal lobe, middle occipital gyrus, and medial and orbital aspects of the frontal lobe. The converse asymmetry was revealed in the frontal operculum, supplementary motor cortex, temporal lobe, limbic cortices, precuneus and cuneus. Our results revealed significant intra- and interhemispheric regional variations in MD in subcortical WM, which may be related to different densities of axons and myelin sheaths. (orig.)

  4. Intra- and interhemispheric variations of diffusivity in subcortical white matter in normal human brain

    Energy Technology Data Exchange (ETDEWEB)

    Yoshiura, Takashi; Noguchi, Tomoyuki; Hiwatashi, Akio; Togao, Osamu; Yamashita, Koji; Nagao, Eiki; Kamano, Hironori; Honda, Hiroshi [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences, Fukuoka (Japan)

    2010-01-15

    Our purpose was to reveal potential regional variations in water molecular diffusivity within each cerebral hemisphere and across the right and left hemispheres. Diffusion-weighted images of 44 healthy right-handed adult male subjects were obtained using a diffusion tensor imaging sequence. Mean diffusivity (MD) values in subcortical white matter (WM) within 39 regions in each hemisphere were measured using an automated method. Intrahemispheric comparisons of MDs in subcortical WM were performed among six brain regions (frontal, parietal, occipital and temporal lobes and pre- and postcentral gyri). Interhemispheric comparisons of MDs were performed between the right and left counterparts of the 39 regions. In both hemispheres, diffusivity in the precentral gyrus was lower than those in other regions, while diffusivity in the parietal lobe was higher than others. MD asymmetry in which the left was lower than the right was found in the parietal lobe, middle occipital gyrus, and medial and orbital aspects of the frontal lobe. The converse asymmetry was revealed in the frontal operculum, supplementary motor cortex, temporal lobe, limbic cortices, precuneus and cuneus. Our results revealed significant intra- and interhemispheric regional variations in MD in subcortical WM, which may be related to different densities of axons and myelin sheaths. (orig.)

  5. Conducting compositions of matter

    Science.gov (United States)

    Viswanathan, Tito (Inventor)

    2000-01-01

    The invention provides conductive compositions of matter, as well as methods for the preparation of the conductive compositions of matter, solutions comprising the conductive compositions of matter, and methods of preparing fibers or fabrics having improved anti-static properties employing the conductive compositions of matter.

  6. Dark fermentation, anaerobic digestion and microbial fuel cells: An integrated system to valorize swine manure and rice bran.

    Science.gov (United States)

    Schievano, Andrea; Sciarria, Tommy Pepè; Gao, Yong Chang; Scaglia, Barbara; Salati, Silvia; Zanardo, Marina; Quiao, Wei; Dong, Renjie; Adani, Fabrizio

    2016-10-01

    This work describes how dark fermentation (DF), anaerobic digestion (AD) and microbial fuel cells (MFC) and solid-liquid separation can be integrated to co-produce valuable biochemicals (hydrogen and methane), bioelectricity and biofertilizers. Two integrated systems (System 1: AD+MFC, and System 2: DF+AD+MFC) are described and compared to a traditional one-stage AD system in converting a mixture (COD=124±8.1gO2kg(-1)Fresh Matter) of swine manure and rice bran. System 1 gave a biomethane yield of 182 LCH4kg(-1)COD-added, while System 2 gave L yields of bio-hydrogen and bio-methane of 27.3±7.2LH2kg(-1)COD-added and 154±14LCH4kg(-1)COD-added, respectively. A solid-liquid separation (SLS) step was applied to the digested slurry, giving solid and liquid fractions. The liquid fraction was treated via the MFC-steps, showing power densities of 12-13Wm(-3) (500Ω) and average bioelectricity yields of 39.8Whkg(-1)COD to 54.2Whkg(-1)COD. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Condensed elementary particle matter

    International Nuclear Information System (INIS)

    Kajantie, K.

    1996-01-01

    Quark matter is a special case of condensed elementary particle matter, matter governed by the laws of particle physics. The talk discusses how far one can get in the study of particle matter by reducing the problem to computations based on the action. As an example the computation of the phase diagram of electroweak matter is presented. It is quite possible that ultimately an antireductionist attitude will prevail: experiments will reveal unpredicted phenomena not obviously reducible to the study of the action. (orig.)

  8. Microstructural white matter alterations and hippocampal volumes are associated with cognitive deficits in craniopharyngioma.

    Science.gov (United States)

    Fjalldal, S; Follin, C; Svärd, D; Rylander, L; Gabery, S; Petersén, Å; van Westen, D; Sundgren, P C; Björkman-Burtscher, I M; Lätt, J; Ekman, B; Johanson, A; Erfurth, E M

    2018-06-01

    Patients with craniopharyngioma (CP) and hypothalamic lesions (HL) have cognitive deficits. Which neural pathways are affected is unknown. To determine whether there is a relationship between microstructural white matter (WM) alterations detected with diffusion tensor imaging (DTI) and cognition in adults with childhood-onset CP. A cross-sectional study with a median follow-up time of 22 (6-49) years after operation. The South Medical Region of Sweden (2.5 million inhabitants). Included were 41 patients (24 women, ≥17 years) surgically treated for childhood-onset CP between 1958-2010 and 32 controls with similar age and gender distributions. HL was found in 23 patients. Subjects performed cognitive tests and magnetic resonance imaging, and images were analyzed using DTI of uncinate fasciculus, fornix, cingulum, hippocampus and hypothalamus as well as hippocampal volumetry. Right uncinate fasciculus was significantly altered ( P  ≤ 0.01). Microstructural WM alterations in left ventral cingulum were significantly associated with worse performance in visual episodic memory, explaining approximately 50% of the variation. Alterations in dorsal cingulum were associated with worse performance in immediate, delayed recall and recognition, explaining 26-38% of the variation, and with visuospatial ability and executive function, explaining 19-29%. Patients who had smaller hippocampal volume had worse general knowledge ( P  = 0.028), and microstructural WM alterations in hippocampus were associated with a decline in general knowledge and episodic visual memory. A structure to function relationship is suggested between microstructural WM alterations in cingulum and in hippocampus with cognitive deficits in CP. © 2018 The authors.

  9. Graph Theoretical Analysis of Developmental Patterns of the White Matter Network

    Directory of Open Access Journals (Sweden)

    Zhang eChen

    2013-11-01

    Full Text Available Understanding the development of human brain organization is critical for gaining insight into how the enhancement of cognitive processes is related to the fine-tuning of the brain network. However, the developmental trajectory of the large-scale white matter (WM network is not fully understood. Here, using graph theory, we examine developmental changes in the organization of WM networks in 180 typically-developing participants. WM networks were constructed using whole brain tractography and 78 cortical regions of interest were extracted from each participant. The subjects were first divided into 5 equal sample size (n=36 groups (early childhood: 6.0-9.7 years; late childhood: 9.8-12.7 years; adolescence: 12.9-17.5 years; young adult: 17.6-21.8 years; adult: 21.9-29.6 years. Most prominent changes in the topological properties of developing brain networks occur at late childhood and adolescence. During late childhood period, the structural brain network showed significant increase in the global efficiency but decrease in modularity, suggesting a shift of topological organization toward a more randomized configuration. However, while preserving most topological features, there was a significant increase in the local efficiency at adolescence, suggesting the dynamic process of rewiring and rebalancing brain connections at different growth stages. In addition, several pivotal hubs were identified that are vital for the global coordination of information flow over the whole brain network across all age groups. Significant increases of nodal efficiency were present in several regions such as precuneus at late childhood. Finally, a stable and functionally/anatomically related modular organization was identified throughout the development of the WM network. This study used network analysis to elucidate the topological changes in brain maturation, paving the way for developing novel methods for analyzing disrupted brain connectivity in

  10. White matter atlas of the human spinal cord with estimation of partial volume effect.

    Science.gov (United States)

    Lévy, S; Benhamou, M; Naaman, C; Rainville, P; Callot, V; Cohen-Adad, J

    2015-10-01

    Template-based analysis has proven to be an efficient, objective and reproducible way of extracting relevant information from multi-parametric MRI data. Using common atlases, it is possible to quantify MRI metrics within specific regions without the need for manual segmentation. This method is therefore free from user-bias and amenable to group studies. While template-based analysis is common procedure for the brain, there is currently no atlas of the white matter (WM) spinal pathways. The goals of this study were: (i) to create an atlas of the white matter tracts compatible with the MNI-Poly-AMU template and (ii) to propose methods to quantify metrics within the atlas that account for partial volume effect. The WM atlas was generated by: (i) digitalizing an existing WM atlas from a well-known source (Gray's Anatomy), (ii) registering this atlas to the MNI-Poly-AMU template at the corresponding slice (C4 vertebral level), (iii) propagating the atlas throughout all slices of the template (C1 to T6) using regularized diffeomorphic transformations and (iv) computing partial volume values for each voxel and each tract. Several approaches were implemented and validated to quantify metrics within the atlas, including weighted-average and Gaussian mixture models. Proof-of-concept application was done in five subjects for quantifying magnetization transfer ratio (MTR) in each tract of the atlas. The resulting WM atlas showed consistent topological organization and smooth transitions along the rostro-caudal axis. The median MTR across tracts was 26.2. Significant differences were detected across tracts, vertebral levels and subjects, but not across laterality (right-left). Among the different tested approaches to extract metrics, the maximum a posteriori showed highest performance with respect to noise, inter-tract variability, tract size and partial volume effect. This new WM atlas of the human spinal cord overcomes the biases associated with manual delineation and partial

  11. Tract-specific fractional anisotropy predicts cognitive outcome in a community sample of middle-aged participants with white matter lesions.

    Science.gov (United States)

    Soriano-Raya, Juan José; Miralbell, Júlia; López-Cancio, Elena; Bargalló, Núria; Arenillas, Juan Francisco; Barrios, Maite; Cáceres, Cynthia; Toran, Pere; Alzamora, Maite; Dávalos, Antoni; Mataró, Maria

    2014-05-01

    Cerebral white matter lesions (WMLs) have been consistently related to cognitive dysfunction but the role of white matter (WM) damage in cognitive impairment is not fully determined. Diffusion tensor imaging is a promising tool to explain impaired cognition related to WMLs. We investigated the separate association of high-grade periventricular hyperintensities (PVHs) and deep white matter hyperintensities (DWMHs) with fractional anisotropy (FA) in middle-aged individuals. We also assessed the predictive value to cognition of FA within specific WM tracts associated with high-grade WMLs. One hundred participants from the Barcelona-AsIA Neuropsychology Study were divided into groups based on low- and high-grade WMLs. Voxel-by-voxel FA were compared between groups, with separate analyses for high-grade PVHs and DWMHs. The mean FA within areas showing differences between groups was extracted in each tract for linear regression analyses. Participants with high-grade PVHs and participants with high-grade DWMHs showed lower FA in different areas of specific tracts. Areas showing decreased FA in high-grade DWMHs predicted lower cognition, whereas areas with decreased FA in high-grade PVHs did not. The predictive value to cognition of specific WM tracts supports the involvement of cortico-subcortical circuits in cognitive deficits only in DWMHs.

  12. Improved longitudinal gray and white matter atrophy assessment via application of a 4-dimensional hidden Markov random field model.

    Science.gov (United States)

    Dwyer, Michael G; Bergsland, Niels; Zivadinov, Robert

    2014-04-15

    SIENA and similar techniques have demonstrated the utility of performing "direct" measurements as opposed to post-hoc comparison of cross-sectional data for the measurement of whole brain (WB) atrophy over time. However, gray matter (GM) and white matter (WM) atrophy are now widely recognized as important components of neurological disease progression, and are being actively evaluated as secondary endpoints in clinical trials. Direct measures of GM/WM change with advantages similar to SIENA have been lacking. We created a robust and easily-implemented method for direct longitudinal analysis of GM/WM atrophy, SIENAX multi-time-point (SIENAX-MTP). We built on the basic halfway-registration and mask composition components of SIENA to improve the raw output of FMRIB's FAST tissue segmentation tool. In addition, we created LFAST, a modified version of FAST incorporating a 4th dimension in its hidden Markov random field model in order to directly represent time. The method was validated by scan-rescan, simulation, comparison with SIENA, and two clinical effect size comparisons. All validation approaches demonstrated improved longitudinal precision with the proposed SIENAX-MTP method compared to SIENAX. For GM, simulation showed better correlation with experimental volume changes (r=0.992 vs. 0.941), scan-rescan showed lower standard deviations (3.8% vs. 8.4%), correlation with SIENA was more robust (r=0.70 vs. 0.53), and effect sizes were improved by up to 68%. Statistical power estimates indicated a potential drop of 55% in the number of subjects required to detect the same treatment effect with SIENAX-MTP vs. SIENAX. The proposed direct GM/WM method significantly improves on the standard SIENAX technique by trading a small amount of bias for a large reduction in variance, and may provide more precise data and additional statistical power in longitudinal studies. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Hydrodynamics of soft active matter

    Science.gov (United States)

    Marchetti, M. C.; Joanny, J. F.; Ramaswamy, S.; Liverpool, T. B.; Prost, J.; Rao, Madan; Simha, R. Aditi

    2013-07-01

    This review summarizes theoretical progress in the field of active matter, placing it in the context of recent experiments. This approach offers a unified framework for the mechanical and statistical properties of living matter: biofilaments and molecular motors in vitro or in vivo, collections of motile microorganisms, animal flocks, and chemical or mechanical imitations. A major goal of this review is to integrate several approaches proposed in the literature, from semimicroscopic to phenomenological. In particular, first considered are “dry” systems, defined as those where momentum is not conserved due to friction with a substrate or an embedding porous medium. The differences and similarities between two types of orientationally ordered states, the nematic and the polar, are clarified. Next, the active hydrodynamics of suspensions or “wet” systems is discussed and the relation with and difference from the dry case, as well as various large-scale instabilities of these nonequilibrium states of matter, are highlighted. Further highlighted are various large-scale instabilities of these nonequilibrium states of matter. Various semimicroscopic derivations of the continuum theory are discussed and connected, highlighting the unifying and generic nature of the continuum model. Throughout the review, the experimental relevance of these theories for describing bacterial swarms and suspensions, the cytoskeleton of living cells, and vibrated granular material is discussed. Promising extensions toward greater realism in specific contexts from cell biology to animal behavior are suggested, and remarks are given on some exotic active-matter analogs. Last, the outlook for a quantitative understanding of active matter, through the interplay of detailed theory with controlled experiments on simplified systems, with living or artificial constituents, is summarized.

  14. Soil organic matter studies

    International Nuclear Information System (INIS)

    1977-01-01

    A total of 77 papers were presented and discussed during this symposium, 37 are included in this Volume II. The topics covered in this volume include: biochemical transformation of organic matter in soils; bitumens in soil organic matter; characterization of humic acids; carbon dating of organic matter in soils; use of modern techniques in soil organic matter research; use of municipal sludge with special reference to heavy metals constituents, soil nitrogen, and physical and chemical properties of soils; relationship of soil organic matter and plant metabolism; interaction between agrochemicals and organic matter; and peat. Separate entries have been prepared for those 20 papers which discuss the use of nuclear techniques in these studies

  15. An integrated brain-behavior model for working memory.

    Science.gov (United States)

    Moser, D A; Doucet, G E; Ing, A; Dima, D; Schumann, G; Bilder, R M; Frangou, S

    2017-12-05

    Working memory (WM) is a central construct in cognitive neuroscience because it comprises mechanisms of active information maintenance and cognitive control that underpin most complex cognitive behavior. Individual variation in WM has been associated with multiple behavioral and health features including demographic characteristics, cognitive and physical traits and lifestyle choices. In this context, we used sparse canonical correlation analyses (sCCAs) to determine the covariation between brain imaging metrics of WM-network activation and connectivity and nonimaging measures relating to sensorimotor processing, affective and nonaffective cognition, mental health and personality, physical health and lifestyle choices derived from 823 healthy participants derived from the Human Connectome Project. We conducted sCCAs at two levels: a global level, testing the overall association between the entire imaging and behavioral-health data sets; and a modular level, testing associations between subsets of the two data sets. The behavioral-health and neuroimaging data sets showed significant interdependency. Variables with positive correlation to the neuroimaging variate represented higher physical endurance and fluid intelligence as well as better function in multiple higher-order cognitive domains. Negatively correlated variables represented indicators of suboptimal cardiovascular and metabolic control and lifestyle choices such as alcohol and nicotine use. These results underscore the importance of accounting for behavioral-health factors in neuroimaging studies of WM and provide a neuroscience-informed framework for personalized and public health interventions to promote and maintain the integrity of the WM network.Molecular Psychiatry advance online publication, 5 December 2017; doi:10.1038/mp.2017.247.

  16. Baryonic Dark Matter

    OpenAIRE

    Silk, Joseph

    1994-01-01

    In the first two of these lectures, I present the evidence for baryonic dark matter and describe possible forms that it may take. The final lecture discusses formation of baryonic dark matter, and sets the cosmological context.

  17. Grammar of the matter

    International Nuclear Information System (INIS)

    Jacob, M.

    1992-01-01

    In this paper, the author describes the structure of the matter and presents the families of elementary particles (fermions) and the interaction messengers (bosons) with their properties. He presents the actual status and future trends of research on nuclear matter

  18. Dark matter detectors

    International Nuclear Information System (INIS)

    Forster, G.

    1995-01-01

    A fundamental question of astrophysics and cosmology is the nature of dark matter. Astrophysical observations show clearly the existence of some kind of dark matter, though they cannot yet reveal its nature. Dark matter can consist of baryonic particles, or of other (known or unknown) elementary particles. Baryonic dark matter probably exists in the form of dust, gas, or small stars. Other elementary particles constituting the dark matter can possibly be measured in terrestrial experiments. Possibilities for dark matter particles are neutrinos, axions and weakly interacting massive particles (WIMPs). While a direct detection of relic neutrinos seems at the moment impossible, there are experiments looking for baryonic dark matter in the form of Massive Compact Halo Objects, and for particle dark matter in the form of axions and WIMPS. (orig.)

  19. Dence Cold Matter

    Directory of Open Access Journals (Sweden)

    Stavinskiy Alexey

    2014-04-01

    Full Text Available Possible way to create dense cold baryonic matter in the laboratory is discussed. The density of this matter is comparable or even larger than the density of neutron star core. The properties of this matter can be controlled by trigger conditions. Experimental program for the study of properties of dense cold matter for light and heavy ion collisions at initial energy range √sNN~2-3GeV is proposed..

  20. Dark Matter Effective Theory

    DEFF Research Database (Denmark)

    Del Nobile, Eugenio; Sannino, Francesco

    2012-01-01

    We organize the effective (self)interaction terms for complex scalar dark matter candidates which are either an isosinglet, isodoublet or an isotriplet with respect to the weak interactions. The classification has been performed ordering the operators in inverse powers of the dark matter cutoff...... scale. We assume Lorentz invariance, color and charge neutrality. We also introduce potentially interesting dark matter induced flavor-changing operators. Our general framework allows for model independent investigations of dark matter properties....

  1. Nonthermal Supermassive Dark Matter

    Science.gov (United States)

    Chung, Daniel J. H.; Kolb, Edward W.; Riotto, Antonio

    1999-01-01

    We discuss several cosmological production mechanisms for nonthermal supermassive dark matter and argue that dark matter may he elementary particles of mass much greater than the weak scale. Searches for dark matter should ma be limited to weakly interacting particles with mass of the order of the weak scale, but should extend into the supermassive range as well.