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Sample records for 3he-mri study lacunarity

  1. Progression of emphysema in a 12-month hyperpolarized 3He-MRI study: lacunarity analysis provided a more sensitive measure than standard ADC analysis.

    Science.gov (United States)

    Diaz, Sandra; Casselbrant, Ingrid; Piitulainen, Eeva; Magnusson, Peter; Peterson, Barry; Pickering, Evelyn; Tuthill, Theresa; Ekberg, Olle; Akeson, Per

    2009-06-01

    Inhaled hyperpolarized (3)He magnetic resonance (MR) imaging has been used to measure alveolar size in patients with emphysema. The aim of this study was to test the hypothesis that (3)He MR images could be used to develop a biomarker of emphysema progression. Twelve healthy controls and 18 patients with emphysema (eight current smokers, 10 ex-smokers) were imaged at baseline and 6 and 12 months. An additional nine subjects with alpha-1 antitrypsin deficiency (four with emphysema, six without symptoms) were also imaged at baseline and at 6 months. Each subject was imaged at two lung volumes: functional residual capacity (FRC) and FRC plus 15% of total lung capacity. Means and standard deviations of apparent diffusion coefficients (ADCs) were calculated from coronal images of the entire lung and correlated with pulmonary function test results. The lacunarity hypothesis was tested and calculated from the data using a range of 2 x 2 x 2 to 6 x 6 x 6 voxels, and the average was calculated. There was no change in the mean ADC at either lung volume in any subject over the 6- or 12-month period. FRC and residual volume increased over the 12 months, suggesting air trapping. The lacunarity of images collected at FRC increased at 6 and 12 months in smokers only (P = .063 and P = .023, respectively). The mean ADC calculated from MR images of the lungs with helium was not sufficiently sensitive to detect changes over a 12-month period. However, lacunarity captured more of the spatial information in the images and detected emphysema progress in the smokers.

  2. Progression of emphysema in a 12-month hyperpolarized 3He-MRI study: lacunarity analysis provided a more sensitive measure than standard ADC analysis

    DEFF Research Database (Denmark)

    Diaz, Sandra; Casselbrant, Ingrid; Piitulainen, Eeva

    2009-01-01

    subject was imaged at two lung volumes: functional residual capacity (FRC) and FRC plus 15% of total lung capacity. Means and standard deviations of apparent diffusion coefficients (ADCs) were calculated from coronal images of the entire lung and correlated with pulmonary function test results......, suggesting air trapping. The lacunarity of images collected at FRC increased at 6 and 12 months in smokers only (P = .063 and P = .023, respectively). CONCLUSIONS: The mean ADC calculated from MR images of the lungs with helium was not sufficiently sensitive to detect changes over a 12-month period. However...

  3. {sup 3}He-MRI in follow-up of lung transplant recipients

    Energy Technology Data Exchange (ETDEWEB)

    Gast, Klaus Kurt; Zaporozhan, Julia; Ley, Sebastian; Biedermann, Alexander; Knitz, Frank; Eberle, Balthasar; Schmiedeskamp, Joerg; Heussel, Claus-Peter; Mayer, Eckhard; Schreiber, Wolfgang Guenter; Thelen, Manfred; Kauczor, Hans-Ulrich [Department of Radiology, Johannes Gutenberg University Hospital, Langenbeckstrasse 1, 55131, Mainz (Germany)

    2004-01-01

    The aim of this study was to evaluate the possible contribution of {sup 3}He-MRI to detect obliterative bronchiolitis (OB) in the follow-up of lung transplant recipients. Nine single- and double-lung transplanted patients were studied by an initial and a follow-up {sup 3}He-MRI study. Images were evaluated subjectively by estimation of ventilation defect area and quantitatively by individually adapted threshold segmentation and subsequent calculation of ventilated lung volume. Bronchiolitis obliterans syndrome (BOS) was diagnosed using pulmonary function tests. At {sup 3}He-MRI, OB was suspected if ventilated lung volume had decreased by 10% or more at the follow-up MRI study compared with the initial study. General accordance between pulmonary function testing and {sup 3}He-MRI was good, although subjective evaluation of {sup 3}He-MRI underestimated improvement in ventilation as obtained by pulmonary function tests. The {sup 3}He-MRI indicated OB in 6 cases. According to pulmonary function tests, BOS was diagnosed in 5 cases. All diagnoses of BOS were also detected by {sup 3}He-MRI. In 2 of these 5 cases, {sup 3}He-MRI indicated OB earlier than pulmonary function tests. The results support the hypothesis that {sup 3}He-MRI may be sensitive for early detection of OB and emphasize the need for larger prospective follow-up studies. (orig.)

  4. Oxygen-sensitive {sup 3}He-MRI in bronchiolitis obliterans after lung transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Gast, Klaus K. [Klinikum der Johannes Gutenberg-Universitaet, Klinik und Poliklinik fuer diagnostische und interventionelle Radiologie, Mainz (Germany); Biedermann, Alexander [Klinikum der Johannes Gutenberg-Universitaet, 3. Medizinische Klinik, Pulmonologie, Mainz (Germany); Herweling, Annette [Klinikum der Johannes Gutenberg-Universitaet, Klinik fuer Anaesthesiologie, Mainz (Germany); Schreiber, Wolfgang G. [Klinikum der Johannes Gutenberg-Universitaet, Klinik und Poliklinik fuer diagnostische und interventionelle Radiologie, MR-Physik, Mainz (Germany); Schmiedeskamp, Joerg [Max-Planck-Institut fuer Polymerforschung, Mainz (Germany); Mayer, Eckhard [Klinikum der Johannes Gutenberg-Universitaet, Klinik fuer Herz-, Thorax- und Gefaesschirurgie, Mainz (Germany); Heussel, Claus P. [Abteilung fuer Radiologie, Thoraxklinik Heidelberg, Heidelberg (Germany); Markstaller, Klaus; Eberle, Balthasar [Inselspital/Universitaetsspital, Klinik fuer Anaesthesiologie, Bern (Switzerland); Kauczor, Hans-Ulrich [Radiologie, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany)

    2008-03-15

    Oxygen-sensitive {sup 3}He-MRI was studied for the detection of differences in intrapulmonary oxygen partial pressure (pO{sub 2}) between patients with normal lung transplants and those with bronchiolitis obliterans syndrome (BOS). Using software developed in-house, oxygen-sensitive {sup 3}He-MRI datasets from patients with normal lung grafts (n = 8) and with BOS (n = 6) were evaluated quantitatively. Datasets were acquired on a 1.5-T system using a spoiled gradient echo pulse sequence. Underlying diseases were pulmonary emphysema (n = 10 datasets) and fibrosis (n = 4). BOS status was verified by pulmonary function tests. Additionally, {sup 3}He-MRI was assessed blindedly for ventilation defects. Median intrapulmonary pO{sub 2} in patients with normal lung grafts was 146 mbar compared with 108 mbar in patients with BOS. Homogeneity of pO2 distribution was greater in normal grafts (standard deviation pO2 34 versus 43 mbar). Median oxygen decrease rate during breath hold was higher in unaffected patients (-1.75 mbar/s versus -0.38 mbar/s). Normal grafts showed fewer ventilation defects (5% versus 28%, medians). Oxygen-sensitive {sup 3}He-MRI appears capable of demonstrating differences of intrapulmonary pO2 between normal lung grafts and grafts affected by BOS. Oxygen-sensitive {sup 3}He-MRI may add helpful regional information to other diagnostic techniques for the assessment and follow-up of lung transplant recipients. (orig.)

  5. Linking Ventilation Heterogeneity Quantified via Hyperpolarized 3He MRI to Dynamic Lung Mechanics and Airway Hyperresponsiveness.

    Science.gov (United States)

    Lui, Justin K; Parameswaran, Harikrishnan; Albert, Mitchell S; Lutchen, Kenneth R

    2015-01-01

    Advancements in hyperpolarized helium-3 MRI (HP 3He-MRI) have introduced the ability to render and quantify ventilation patterns throughout the anatomic regions of the lung. The goal of this study was to establish how ventilation heterogeneity relates to the dynamic changes in mechanical lung function and airway hyperresponsiveness in asthmatic subjects. In four healthy and nine mild-to-moderate asthmatic subjects, we measured dynamic lung resistance and lung elastance from 0.1 to 8 Hz via a broadband ventilation waveform technique. We quantified ventilation heterogeneity using a recently developed coefficient of variation method from HP 3He-MRI imaging. Dynamic lung mechanics and imaging were performed at baseline, post-challenge, and after a series of five deep inspirations. AHR was measured via the concentration of agonist that elicits a 20% decrease in the subject's forced expiratory volume in one second compared to baseline (PC20) dose. The ventilation coefficient of variation was correlated to low-frequency lung resistance (R = 0.647, P ventilation heterogeneity. Also, the degree of AHR appears to be dependent on the degree to which baseline airway constriction creates baseline ventilation heterogeneity. HP 3He-MRI imaging may be a powerful predictor of the degree of AHR and in tracking the efficacy of therapy.

  6. Hyperpolarized 3He MRI and 81mKr SPECT in chronic obstructive pulmonary disease

    DEFF Research Database (Denmark)

    Stavngaard, Trine; Søgaard, Lise; Mortensen, J

    2005-01-01

    was to compare ventilation imaging methods in 26 patients with chronic obstructive pulmonary disease (COPD) and nine lung healthy volunteers. METHODS: HP 3He MRI, 81mKr single-photon emission computed tomography (SPECT), high-resolution computed tomography (HRCT) and pulmonary function tests were performed...... visual defect score (r=0.80, ptest and HRCT). The defect scores were largest on 81mKr SPECT (the score on HP 3He MRI...... was one-third less than that on 81mKr SPECT), but the difference was reduced after normalisation for different breathing depths (HP 3He MRI at total lung capacity; 81mKr SPECT at tidal breathing at functional residual capacity). CONCLUSION: HP 3He MRI provides detailed ventilation distribution images...

  7. Quantitative analysis of regional airways obstruction using dynamic hyperpolarized 3He MRI-preliminary results in children with cystic fibrosis.

    Science.gov (United States)

    Koumellis, Panos; van Beek, Edwin J R; Woodhouse, Neil; Fichele, Stan; Swift, Andrew J; Paley, Martyn N J; Hill, Catherine; Taylor, Chris J; Wild, Jim M

    2005-09-01

    To investigate regional airways obstruction in patients with cystic fibrosis (CF) with quantitative analysis of dynamic hyperpolarized (HP) (3)He MRI. Dynamic radial projection MRI of HP (3)He gas was used to study respiratory dynamics in a group of eight children with CF. Signal kinetics in a total of seven regions of interest (ROIs; three in each lung, and one in the trachea) were compared with the results of spirometric pulmonary function tests (PFTs). The tracheal signal intensity was used as a form of "input function" to normalize for input flow effects. A pattern of low flow rate in the upper lobes was observed. When the flow measurements from the peripheral ROIs were averaged to obtain an index of flow in the peripheral lung, a good correlation was found (P = 3.74 x 10(-5)) with the forced expired volume in one second (FEV1). These results suggest that a quantitative measurement of localized airways obstruction in the early stages of CF may be obtained from dynamic (3)He MRI by using the slope of the signal rise as a measure of air flow into the peripheral lung. This study also demonstrates that children can cooperate well with the (3)He MRI technique. (c) 2005 Wiley-Liss, Inc.

  8. (3)He MRI in healthy volunteers: preliminary correlation with smoking history and lung volumes.

    Science.gov (United States)

    Guenther, D; Eberle, B; Hast, J; Lill, J; Markstaller, K; Puderbach, M; Schreiber, W G; Hanisch, G; Heussel, C P; Surkau, R; Grossmann, T; Weiler, N; Thelen, M; Kauczor, H U

    2000-06-01

    MRI with hyperpolarized helium-3 ((3)He) provides high-resolution imaging of ventilated airspaces. The first aim of this (3)He-study was to compare observations of localized signal defects in healthy smokers and non-smokers. A second aim was to describe relationships between parameters of lung function, volume of inspired (3)He and signal-to-noise ratio. With Ethics Committee approval and informed consent, 12 healthy volunteers (seven smokers and five non-smokers) were studied. Imaging was performed in a 1.5 T scanner using a two-dimensional FLASH sequence at 30V transmitter amplitude (TR/TE/alpha = 11 ms/4.2 ms/microprocessor-controlled delivery device and imaged during single breath-holds. Images were evaluated visually, and scored using a prospectively defined 'defect-index'. Signal-to-noise ratio of the images were correlated with localization, (3)He volumes and static lung volumes. Due to poor image quality studies of two smokers were not eligible for the evaluation. Smokers differed from non-smokers in total number and size of defects: the 'defect-index' of smokers ranged between 0.8 and 6.0 (median = 1.1), that of non-smokers between 0.1 and 0.8 (median = 0.4). Intraindividually, an anteroposterior gradient of signal-to-noise ratio was apparent. Signal-to-noise ratio correlated with the estimated amount of hyperpolarization administered (r = 0. 77), but not with static lung volumes. We conclude that (3)He MRI is a sensitive measure to detect regional abnormalities in the distribution of ventilation in clinically healthy persons with normal pulmonary function tests.

  9. Dynamic ventilation 3He MRI for the quantification of disease in the rat lung.

    Science.gov (United States)

    Kyriazis, Angelos; Rodriguez, I; Nin, N; Izquierdo-Garcia, J L; Lorente, J A; Perez-Sanchez, J M; Pesic, J; Olsson, L E; Ruiz-Cabello, J

    2012-03-01

    Pulmonary diseases are known to be largely inhomogeneous. To evaluate such inhomogeneities, we are testing an image-based method to measure gas flow in the lung regionally. Dynamic, spin-density-weighted hyperpolarized (3)He MR images performed during slow inhalation of this gas were analyzed to quantify regional inflation rate. This parameter was measured in regions of interest (ROIs) that were defined by a rectangular grid that covered the entire rat lung and grew dynamically with it during its inflation. We used regional inflation rate to quantify elastase-induced emphysema and to differentiate healthy (n = 8) from elastase-treated (n = 9) rat lungs as well as healthy from elastase-treated areas of one rat unilaterally treated with elastase in the left lung. Emphysema was also assessed by gold standard morphological and well-established hyperpolarized (3)He MRI diffusion measurements. Mean values of regional inflation rates were significantly different for healthy and elastase-treated animals and correlated well with the apparent diffusion coefficient of (3)He and morphological measurements. The image-based biomarker inflation rate may be useful for the assessment of regional lung ventilation.

  10. Lacunar versus non-lacunar syndromes.

    Science.gov (United States)

    Micheli, Sara; Corea, Francesco

    2012-01-01

    Small-vessel disease is the accepted most frequent cause of lacunar stroke. The main clinical features seen with lacunar infarcts are motor and/or sensitive deficit, ataxic sign, without cortical involvement. A lacunar syndrome is generally the result of a small deep infarct within the territory of a single perforating artery with the maximum diameter on imaging of 15 mm. Recent studies have demonstrated alternative causes of lacunar stroke other than small-vessel disease (e.g. cardio embolism, atherosclerosis or other causes), especially in large lacunae, with a potential relevance on functional outcome. These findings suggest that lacunar stroke is not always a benign disease. Moreover, clinical features may be significant in terms of disability in lacunae in close proximity to crucial anatomical site. The following chapter reports the classical lacunar syndrome and discusses the debated etiology of lacunar stroke.

  11. A robust protocol for regional evaluation of methacholine challenge in mouse models of allergic asthma using hyperpolarized 3He MRI.

    Science.gov (United States)

    Thomas, Abraham C; Potts, Erin N; Chen, Ben T; Slipetz, Deborah M; Foster, W Michael; Driehuys, Bastiaan

    2009-06-01

    Hyperpolarized (HP) (3)He magnetic resonance imaging has been recently used to produce high-resolution images of pulmonary ventilation after methacholine (MCh) challenge in mouse models of allergic inflammation. This capability presents an opportunity to gain new insights about these models and to more sensitively evaluate new drug treatments in the pre-clinical setting. In the current study, we present our initial experience using two-dimensional (2D), time-resolved (3)He MRI of MCh challenge-induced airways hyperreactivity (AHR) to compare ovalbumin-sensitized and challenged (N = 8) mice to controls (N = 8). Imaging demonstrated that ovalbumin-sensitized and challenged animals exhibited many large ventilation defects even prior to MCh challenge (four out of eight) compared to no defects in the control animals. Additionally, the ovalbumin-sensitized and challenged animals experienced a greater number of ventilation defects (4.5 +/- 0.4) following MCh infusion than did controls (3.3 +/- 0.6). However, due to variability in MCh delivery that was specific to the small animal MRI environment, the difference in mean defect number was not statistically significant. These findings are reviewed in detail and a comprehensive solution to the variability problem is presented that has greatly enhanced the magnitude and reproducibility of the MCh response. This has permitted us to develop a new imaging protocol consisting of a baseline 3D image, a time-resolved 2D series during MCh challenge, and a post-MCh 3D image that reveals persistent ventilation defects.

  12. Validity of apparent diffusion coefficient hyperpolarized 3He-MRI using MSCT and pulmonary function tests as references

    DEFF Research Database (Denmark)

    Diaz, Sandra; Casselbrant, Ingrid; Piitulainen, Eeva

    2008-01-01

    from MSCT. Both mean ADC and MSCT data were compared to PFT, especially percent of predicted diffusing capacity of carbon monoxide (%predicted DLCO), using Pearson's correlation test. RESULTS: Mean ADC and standard deviation values were 0.392+/-0.119 cm(2)/s for the established emphysema group and 0....... Correlations between mean ADC and EI and 15th percentile were both r=0.90 and for MLD r=0.59. There was higher correlation between mean ADC and %predicted DLCO (r=0.90) than between EI and %predicted DLCO (r=0.76). CONCLUSION: HP (3)He-MRI correlates well with density measurements from MSCT and agrees better...

  13. Clinical predictors of lacunar syndrome not due to lacunar infarction

    Directory of Open Access Journals (Sweden)

    Comes Emili

    2010-05-01

    Full Text Available Background Lacunar syndrome not due to lacunar infarct is poorly characterised. This single centre, retrospective study was conducted to describe the clinical characteristics of patients with lacunar syndrome not due to lacunar infarct and to identify clinical predictors of this variant of lacunar stroke. Methods A total of 146 patients with lacunar syndrome not due to lacunar infarction were included in the "Sagrat Cor Hospital of Barcelona Stroke Registry" during a period of 19 years (1986-2004. Data from stroke patients are entered in the stroke registry following a standardized protocol with 161 items regarding demographics, risk factors, clinical features, laboratory and neuroimaging data, complications and outcome. The characteristics of these 146 patients with lacunar syndrome not due to lacunar infarct were compared with those of the 733 patients with lacunar infarction. Results Lacunar syndrome not due to lacunar infarct accounted for 16.6% (146/879 of all cases of lacunar stroke. Subtypes of lacunar syndromes included pure motor stroke in 63 patients, sensorimotor stroke in 51, pure sensory stroke in 14, atypical lacunar syndrome in 9, ataxic hemiparesis in 5 and dysarthria-clumsy hand in 4. Valvular heart disease, atrial fibrillation, sudden onset, limb weakness and sensory symptoms were significantly more frequent among patients with lacunar syndrome not due to lacunar infarct than in those with lacunar infarction, whereas diabetes was less frequent. In the multivariate analysis, atrial fibrillation (OR = 4.62, sensorimotor stroke (OR = 4.05, limb weakness (OR = 2.09, sudden onset (OR = 2.06 and age (OR = 0.96 were independent predictors of lacunar syndrome not due to lacunar infarct. Conclusions Although lacunar syndromes are highly suggestive of small deep cerebral infarctions, lacunar syndromes not due to lacunar infarcts are found in 16.6% of cases. The presence of sensorimotor stroke, limb weakness and sudden onset in a patient

  14. Branch Atheromatous Plaque: A Major Cause of Lacunar Infarction (High-Resolution MRI Study

    Directory of Open Access Journals (Sweden)

    Jong-Won Chung

    2012-07-01

    Full Text Available Background: Lacunar infarctions account for up to 25% of all ischemic strokes and, thus, constitute a numerically important subgroup. It is important that the two pathogeneses of lacunar infarction, that is, small-vessel occlusion and branch atheromatous disease, be differentiated because prognoses and treatment strategies differ. The authors evaluated the presence of branch atheromatous plaque in parent arteries that supply lacunar infarcts by high-resolution magnetic resonance imaging (HR-MRI. Methods: HR-MRI was performed in 15 patients with (1 a clinical presentation consistent with classical lacunar syndromes; (2 an acute lacunar infarction by diffusion-weighted imaging, measuring ≤20 mm in maximal diameter; (3 a magnetic resonance angiography showing a normal middle cerebral artery or basilar artery supplying the ischemic lesion, and (4 no other obvious etiology for small-vessel distribution ischemic stroke. Results: The median time of vessel wall imaging after index events was 4 days (range, 2–15 days. Six of the 15 patients had a lacunar infarction in the middle cerebral artery territory, and 9 had a lesion in the basilar artery territory. HR-MRI detected underlying atheromatous plaques in 9 patients (60% with a lacunar infarction. In these 9 patients, asymptomatic intracranial atherosclerotic stenosis was more frequent compared to patients without branch atheromatous plaque (55.6 vs. 16.7%. In pontine infarctions, ischemic lesions that extended to the pial base of the pons were more frequent in patients with branch atheromatous plaques (83.3 vs. 33.3%, and all the ischemic lesions and atheromatous plaques were on the same side (right, n = 2; left, n = 4. All plaques responsible for acute symptomatic lacunar infarction were enhanced in contrast-enhanced T1-weighted HR-MR images. Conclusions: HR-MRI results enabled underlying symptomatic branch atheromatous disease to be detected in lacunar infarction patients. The experience gained

  15. Analysis of acute ischemic stroke presenting classic lacunar syndrome. A study by diffusion-weighted MRI

    Energy Technology Data Exchange (ETDEWEB)

    Terai, Satoshi; Ota, Kazuki; Tamaki, Kinya [Hakujyuji Hospital, Fukuoka (Japan)

    2002-03-01

    We retrospectively assessed the pathophysiological features of acute ischemic stroke presenting ''classic'' lacunar syndrome by using diffusion-weighted imaging (DWI). Subjects were 16 patients who were admitted to our hospital within 24 hours of stroke onset and underwent DWI examination on admission. These were divided into three categorical groups; pure motor hemiplegia (PMH) in 8, sensorimotor stroke (SMS) in 7, and dysarthria-clumsy hand syndrome (DCHS) in 1. The fresh responsible lesions were identified by DWI in the perforating territory in 7 patients with PMH and 7 with SMS. Four (one had two possible response lesions; pons and corona radiata) and five patients in the respective groups were diagnosed as lacunar infarction on admission (the largest dimension of the lesion measuring smaller than 15 mm). On the contralateral side to the neurological symptoms, DWI revealed high intensities in cortex, subcortical white matter, and anterior and posterior border zones in the remaining one patient with PMH and in the precentral arterial region in one with DCHS. They were diagnosed as atherothrombotic infarction resulting from the occlusion of the internal carotid artery and cerebral embolism due to atrial fibrillation, respectively. Three patients with PMH showed progressive deterioration after admission and follow-up DWI study in an acute stage revealed enlargement of heir ischemic lesions. The present study suggests that DWI is a useful imaging technique for diagnosis of clinical categories and observation for pathophsiological alteration in the acute ischemic stroke patients with ''classic'' lacunar syndrome. Our results also indicate a necessity to be aware that various types of fresh ischemic lesions other than a single lacune might possibly be developing in cases with this syndrome. (author)

  16. A suggested generalization for the lacunarity index

    Science.gov (United States)

    Vernon-Carter, J.; Lobato-Calleros, C.; Escarela-Perez, R.; Rodriguez, E.; Alvarez-Ramirez, J.

    2009-10-01

    Nowadays, lacunarity is a well-accepted concept to complement fractality studies of complex sets. Lacunarity features are used to assess the largeness of gaps or holes of complex signals and images. As it stands, the lacunarity analysis used is an index averaging the behavior of small- and large-size structures in a given set. The aim of this work is to propose a generalized lacunarity concept on the basis of generalized moments. In this form, the lacunarity index, depending on a discrimination parameter, is oriented to quantify lacunarity associated with objects of different size. Textbook and real images are used to illustrate the ability of the generalized lacunarity index for displaying interesting features of real complex sets.

  17. Study of Local Mineralized Intensity Using Rescaled Range Analysis and Lacunarity Analysis

    Directory of Open Access Journals (Sweden)

    Li Wan

    2013-07-01

    Full Text Available In this paper, the gold grade series along drifts have been analyzed using two methods, rescaled range analysis and lacunarity analysis which are commonly used in nonlinear systems analysis. The aim of this study is to better understand the ore-forming processes and identify the local mineralized intensity and interactions that influence the spatial structure of gold element grade distribution, in the Dayingezhuang fault-controlled, disseminated-veinlet gold deposit in the Jiaodong gold province, eastern China. The result shows that the efficiency of two methods, in distinguishing between weakly mineralized, moderately mineralized and intensely mineralized of ore-forming area. It is obvious that the two parameters of both Hurst and lacunarity index in the weakly mineralized drifts are distinguished from those in the mineralized drifts, and the lower the index is, the more homogeneously distributed of the elements and the mineral intensity is relatively smaller. The methods used in this paper provide a relatively comprehensive description for local mineral intensity, offering an evidence for the identification of mineralization intensity and providing a guidance for further determination to the extent of deposit concentration and delineation of target mineralization zone.

  18. Clinical study on magnetic resonance imaging of lacunar infarcts and cerebrovascular high-risk group

    Energy Technology Data Exchange (ETDEWEB)

    Hironaka, Masatoshi (Hiroshima Univ. (Japan). School of Medicine)

    1990-04-01

    Magnetic resonance imaging (MRI) study was performed in 32 patients with recent lacunar stroke. T2-weighted images showed ischemic lesions more clearly than T1-weighted images. Sixty-six percent of 32 patients had periventricular lesions. Eighty-four percent had subcortical white matter lesions. Sixty-nine percent had lesions in basal ganglia. Twenty-eight percent had lesions in brainstem. Periventricular lesions were revealed symmetrically. On the other hand, lesions in other areas were not detected symmetrically. Severe periventricular lesions on MRI were similar to those of Binswanger's disease. Patients with severe periventricular lesions had often hypertension. Moreover, two of them had dementia. Twenty-three patients with transient ischemic attack had less remarkable lesions than patients with lacunar stroke. Thirty-seven patients with a history of cerebrovascular risk factors (hypertension, diabetes mellitus) had severer lesions compared with normal controls. Sixty-one percent of controls, who had no cerebrovascular symptoms and signs, had MRI lesions. These results suggest that MRI is useful for detection of cerebral ischemic lesions with no associated clinical symptoms or signs. (author).

  19. Cosmic lacunarity.

    Science.gov (United States)

    Provenzale, A.; Spiegel, E. A.; Thieberger, R.

    1997-03-01

    The present distribution of galaxies in space is a remnant of their formation and interaction. On a large enough scale, we may represent the galaxies as a set of points and quantify the structures in this set by its generalized dimensions [Beck and Schlogl, Thermodynamics of Chaotic Systems (Cambridge University Press, Cambridge, 1986); Paladin and Vulpiani, Phys. Rep. 156, 147 (1987)]. The results of such evaluation are often taken to be evidence of a fractal (or multifractal) distribution of galaxies. However, those results, for some scales, may also reveal the presence of singularities formed in the gravitational processes that produce structure in the galaxy distribution. To try to make some decision about this issue, we look for the more subtle galactic lacunarity. We believe that this quantity is discernible in the currently available data and that it provides important evidence on the galaxy formation process. (c) 1997 American Institute of Physics.

  20. Osteocyte lacunar properties in rat cortical bone

    DEFF Research Database (Denmark)

    Bach-Gansmo, Fiona Linnea; Weaver, James C.; Jensen, Mads Hartmann

    2015-01-01

    to osteocyte function, osteocyte lacunar properties such as volume, shape, orientation, and density are now frequently reported in studies investigating osteocyte activity. Despite this increasing interest in lacunar morphometrics, many studies show a large spread in such values, suggesting a large inter......-species but also inter-site variation in lacunar properties. Here, osteocyte lacunae in rat cortical bone have been studied using synchrotron radiation micro computed tomography (SR μCT) and backscattered electron (BE) microscopy. Quantitative lacunar geometric characteristics are reported based on the synchrotron...... radiation data, differentiating between circumferential lamellar bone and a central, more disordered bone type. From these studies, no significant differences were found in lacunar volumes between lamellar and central bone, whereas significant differences in lacunar orientation, shape and density values...

  1. Development and application of methods to quantify spatial and temporal hyperpolarized 3He MRI ventilation dynamics: preliminary results in chronic obstructive pulmonary disease

    Science.gov (United States)

    Kirby, Miranda; Wheatley, Andrew; McCormack, David G.; Parraga, Grace

    2010-03-01

    Hyperpolarized helium-3 (3He) magnetic resonance imaging (MRI) has emerged as a non-invasive research method for quantifying lung structural and functional changes, enabling direct visualization in vivo at high spatial and temporal resolution. Here we described the development of methods for quantifying ventilation dynamics in response to salbutamol in Chronic Obstructive Pulmonary Disease (COPD). Whole body 3.0 Tesla Excite 12.0 MRI system was used to obtain multi-slice coronal images acquired immediately after subjects inhaled hyperpolarized 3He gas. Ventilated volume (VV), ventilation defect volume (VDV) and thoracic cavity volume (TCV) were recorded following segmentation of 3He and 1H images respectively, and used to calculate percent ventilated volume (PVV) and ventilation defect percent (VDP). Manual segmentation and Otsu thresholding were significantly correlated for VV (r=.82, p=.001), VDV (r=.87 p=.0002), PVV (r=.85, p=.0005), and VDP (r=.85, p=.0005). The level of agreement between these segmentation methods was also evaluated using Bland-Altman analysis and this showed that manual segmentation was consistently higher for VV (Mean=.22 L, SD=.05) and consistently lower for VDV (Mean=-.13, SD=.05) measurements than Otsu thresholding. To automate the quantification of newly ventilated pixels (NVp) post-bronchodilator, we used translation, rotation, and scaling transformations to register pre-and post-salbutamol images. There was a significant correlation between NVp and VDV (r=-.94 p=.005) and between percent newly ventilated pixels (PNVp) and VDP (r=- .89, p=.02), but not for VV or PVV. Evaluation of 3He MRI ventilation dynamics using Otsu thresholding and landmark-based image registration provides a way to regionally quantify functional changes in COPD subjects after treatment with beta-agonist bronchodilators, a common COPD and asthma therapy.

  2. Higher ambulatory blood pressure relates to new cerebral microbleeds: 2-year follow-up study in lacunar stroke patients.

    Science.gov (United States)

    Klarenbeek, Pim; van Oostenbrugge, Robert J; Rouhl, Rob P W; Knottnerus, Iris L H; Staals, Julie

    2013-04-01

    Elevated blood pressure (BP) is associated with the presence of cerebral microbleeds (CMBs) in cross-sectional studies. However, longitudinal studies did not show a convincing relationship. We aimed to determine the association between elevated BP levels and the occurrence of new CMBs after a 2-year follow-up in first-ever lacunar stroke patients using ambulatory BP monitoring. Ninety-six first-ever lacunar stroke patients underwent brain MRI and ambulatory BP monitoring at baseline and after 2-year follow-up. We used logistic regression analyses to assess the association of BP levels with new CMBs. We found new CMBs in 17 patients (18%). Higher 24-hour, day and night systolic BP (odds ratio, 2.69; 95% confidence interval, 1.40-5.21 per SD increase for 24-hour BP) and diastolic BP (odds ratio, 2.13; 95% confidence interval, 1.15-3.90 per SD increase for 24-hour BP) at baseline were associated with the development of new CMBs independent of age and sex. BP levels decreased during follow-up in both patients with and without new CMBs. Unlike BP levels at baseline, there was no difference in BP levels at follow-up between patients with and without new CMBs. Both higher systolic and diastolic BP levels were associated with the development of new CMBs in a population of lacunar stroke patients. Decrease of BP levels during follow-up did not halt progression of CMBs; however, it remains to be determined whether (early) intervention with antihypertensive drugs can slow down progression of CMBs.

  3. Multifractal modelling and 3D lacunarity analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hanen, Akkari, E-mail: bettaieb.hanen@topnet.t [Laboratoire de biophysique, TIM, Faculte de Medecine (Tunisia); Imen, Bhouri, E-mail: bhouri_imen@yahoo.f [Unite de recherche ondelettes et multifractals, Faculte des sciences (Tunisia); Asma, Ben Abdallah, E-mail: asma.babdallah@cristal.rnu.t [Laboratoire de biophysique, TIM, Faculte de Medecine (Tunisia); Patrick, Dubois, E-mail: pdubois@chru-lille.f [INSERM, U 703, Lille (France); Hedi, Bedoui Mohamed, E-mail: medhedi.bedoui@fmm.rnu.t [Laboratoire de biophysique, TIM, Faculte de Medecine (Tunisia)

    2009-09-28

    This study presents a comparative evaluation of lacunarity of 3D grey level models with different types of inhomogeneity. A new method based on the 'Relative Differential Box Counting' was developed to estimate the lacunarity features of grey level volumes. To validate our method, we generated a set of 3D grey level multifractal models with random, anisotropic and hierarchical properties. Our method gives a lacunarity measurement correlated with the theoretical one and allows a better model classification compared with a classical approach.

  4. Multifractal modelling and 3D lacunarity analysis

    Science.gov (United States)

    Hanen, Akkari; Imen, Bhouri; Asma, Ben Abdallah; Patrick, Dubois; Hédi, Bedoui Mohamed

    2009-09-01

    This study presents a comparative evaluation of lacunarity of 3D grey level models with different types of inhomogeneity. A new method based on the “Relative Differential Box Counting” was developed to estimate the lacunarity features of grey level volumes. To validate our method, we generated a set of 3D grey level multifractal models with random, anisotropic and hierarchical properties. Our method gives a lacunarity measurement correlated with the theoretical one and allows a better model classification compared with a classical approach.

  5. Physical and structural studies of chemical Vapor deposited lacunar neodymium manganite thin films

    Directory of Open Access Journals (Sweden)

    Oumezzine M.

    2012-06-01

    Full Text Available Lacunar Nd1-xMnO3-δ thin films were successfully deposited by a liquid source metal-organic MOCVD technique on (001 SrTiO3 (STO, LaAlO3 (LAO and Si substrates. Optimal growth conditions are reported. TEM and X-ray diffraction characterisations reveal that the thin films grown on STO and LAO substrates are single crystalline layers epitaxially grown on the top of the substrates. The relationship between the crystallographic orientation of the films and those of the substrates were determined. Magnetic transition temperatures (Tc of the as-grown STO films, deduced from Squid Magnetometer measurements, are compared to the corresponding bulk values (typically 100K. Our magnetic measurements also suggest a complicated magnetic behavior close to the one observed in bulk samples: magnetization curves obtained under different applied magnetic fields indicate a possible reverse of the magnetization sign at low temperatures.

  6. Fractal dimension and lacunarity analysis of mammographic patterns in assessing breast cancer risk related to HRT treated population: a longitudinal and cross-sectional study

    Science.gov (United States)

    Karemore, Gopal; Nielsen, Mads

    2009-02-01

    Structural texture measures are used to address the aspect of breast cancer risk assessment in screening mammograms. The current study investigates whether texture properties characterized by local Fractal Dimension (FD) and Lacunarity contribute to asses breast cancer risk. FD represents the complexity while the Lacunarity characterize the gappiness of a fractal. Our cross-sectional case-control study includes mammograms of 50 patients diagnosed with breast cancer in the subsequent 2-4 years and 50 matched controls. The longitudinal double blind placebo controlled HRT study includes 39 placebo and 36 HRT treated volunteers for two years. ROIs with same dimension (250*150 pixels) were created behind the nipple region on these radiographs. Box counting method was used to calculate the fractal dimension (FD) and the Lacunarity. Paired t-test and Pearson correlation coefficient were calculated. It was found that there were no differences between cancer and control group for FD (P=0.8) and Lacunarity (P=0.8) in crosssectional study whereas earlier published heterogeneity examination of radiographs (BC-HER) breast cancer risk score separated groups (p=0.002). In the longitudinal study, FD decreased significantly (PBIRADS (-0.34, P<0.001) and Percentage Density (-0.41, P<0.001). FD is invariant to the mammographic texture change from control to cancer population but marginally varying in HRT treated population. This study yields no evidence that lacunarity or FD are suitable surrogate markers of mammographic heterogeneity as they neither pick up breast cancer risk, nor show good sensitivity to HRT.

  7. Lacunarity as a texture measure for a tropical forest landscape

    Energy Technology Data Exchange (ETDEWEB)

    Su, Haiping; Krummel, J.

    1996-01-01

    Fragmentation and loss of tropical forest cover alters terrestrial plant and animal population dynamics, reduces biodiversity and carbon storage capacity, and, as a global phenomenon could affect regional and global climate patterns. Lacunarity as a texture measure can offer a simple solution to characterize the texture of tropical forest landscape and determine spatial patterns associated with ecological processes. Lacunarity quantifies the deviation from translational invariance by describing the distribution of gaps within a binary image at multiple scales. As lacunarity increases, the spatial arrangement of tropical forest gaps will also increase. In this study, we used the Spatial Modeler in Imagine as a graphic programming tool to calculate lacunarity indices for a tropical forest landscape in Southern Mexico and Northern Guatemala. Lacunarity indices were derived from classified Landsat MSS images acquired in 1974 and 1984. Random-generated binary images were also used to derive lacunarity indices and compared with the lacunarity of forest patterns derived from the classified MSS images. Tropical forest area declined about 17%, with most of the forest areas converted into pasture/grassland for grazing. During this period, lacunarity increased about 25%. Results of this study suggest that tropical forest fragmentation could be quantified with lacunarity measures. The study also demonstrated that the Spatial Modeler can be useful as a programming tool to quantify spatial patterns of tropical forest landscape by using remotely sensed data.

  8. Correlative factors of cognitive impairment in patients with lacunar infarcts

    Institute of Scientific and Technical Information of China (English)

    Zhang Qiujuan; Yao Xiaoxin; Guo Youmin; Zhang Gejuan; Yang Junle

    2007-01-01

    Objective To study the relationships between cognitive impairment in patients with lacunar infarcts and quantitative CT measures and to determine the independent correlative factors of cognitive impairment. Methods Neuropsychological examination was conducted for 128 patients with acute lacunar infarct. Number, location, and volume of infarcts, cerebral atrophy index and severity of white matter lesions (WMLs) were measured and recorded. Results The number of lacunar infarcts in cognitive impairment (CI) group was significantly larger than that in cognitive normal (CN) group. Mean width of sulcus and sylvian fissure, index of frontal horn and ventricular-brain ratio (VBR) were significantly different in both groups. There were more patients with 3 grades or 4 grades WMLs in CI group (62%) than those in CN group (22%). The total volume of lacunar infarcts showed no statistically significant difference. Logistic regression analysis indicated that the number of lacunar infarcts in frontal subcortex and thalamus, the volume of infarcts in anterior periventricular white matter, width of cerebral sulcus and sylvian fissure were correlated with cognitive impairment respectively. Additionally, age and education were correlative factors of cognitive impairment in patients with lacunar infarct. Conclusion Correlative factors of cognitive impairment in patients with lacunar infarct are not merely one feature, but a combination of infarct features (number, location, and volume), cortical atrophy and host factors (age and education).

  9. Enlarged perivascular spaces and lacunar infarction Cerebral magnetic resonance evaluation

    Institute of Scientific and Technical Information of China (English)

    Weihong Yan; Jing Fang; Cuijuan Zhou

    2008-01-01

    BACKGROUND:Previous studies have demonstrated that enlarged perivascular spaces(EPVS)arg a result of microvaseular disease.To date,there age few reports about the relationship between EPVS and lacunar infarction.OBJECTIVE:To investigate whether EPVS is associated with lacunar infarction on the basis of cerebral magnetic resonance(MR)examination,clinical symptoms and signs,and past medical history of patients.DESIGN,TIME AND SETTING:Case contrast analysis was performed at the Department of Neurology,Shanghai Ninth People's Hospital from January 2007 to January 2008.PARTICIPANTS:Sixty-eight patients with lacunar infarction were admired to the Department of Neurology of Shanghai Ninth People's Hospital,including 37 cases with first-ever infarction,and 31 with infarction recurrence.In addition,53 healthy people were selected as controls.METHODS:All participants underwent past medical history investigation,nervous system examination.and cranial MR.The subjects were assessed using the JMW rating scale to identify the EPVS grade.MAIN OUTCOME MEASURES:EPVS scores of patients and controls;risk factors for cerebral vascular disease in patients with first-ever or recurrence of lacunar infarction.RESULTS:The EPVS grade from lacunar infarction patients was significantly higher than of the control group(P<0.05).The EPVS grade in patients with recurring lacunar infarction was significantly higher than in patients with first-ever infarction(P<0.05).In addition,hypertension incidence in patients with recurring lacunar infarction was significantly higher than in patients wim first-ever infarction (P<0.05).CONCLUSION:Results indicate that EPVS is related to the incidence of lacunar infarction.Earlier screening of EPVS.and the evaluation of EPVS severity,is of great importance to control the risk factors for cerebral vascular disease and to prevent lacunar infarction.

  10. Accumulation of MRI markers of cerebral small vessel disease is associated with decreased cognitive function. A study in first-ever lacunar stroke and hypertensive patients.

    Directory of Open Access Journals (Sweden)

    Marjolein eHuijts

    2013-11-01

    Full Text Available Background – White matter lesions (WMLs, asymptomatic lacunar infarcts, brain microbleeds (BMBs and enlarged perivascular spaces (EPVS have been identified as silent lesions due to cerebral small vessel disease (cSVD. All these markers have been individually linked to cognitive functioning, but are also strongly correlated with each other. The combined effect of these markers on cognitive function has never been studied and would possibly provide more useful information on the effect on cognitive function. Methods – Brain MRI and extensive neuropsychological assessment were performed in 189 patients at risk for cSVD (112 hypertensive patients and 77 first-ever lacunar stroke patients. We rated the presence of any asymptomatic lacunar infarct, extensive WMLs, any deep BMB, and moderate to extensive EPVS in the basal ganglia. The presence of each marker was summed to an ordinal score between 0 and 4. Associations with domains of cognitive function (memory, executive function, information processing speed and overall cognition were analyzed with correlation analyses. Results – Correlation analyses revealed significant associations between accumulating cSVD burden and decreased performance on all cognitive domains (all p≤.001. Results remained significant for information processing speed (r=-.181, p=.013 and overall cognition (r=-.178, p=.017, after correction for age and sex. Testing of trend using linear regression analyses revealed the same results. Discussion – We tested a new approach to capture total brain damage resulting from cSVD and found that accumulation of MRI burden of cSVD is associated with decreased performance on tests of information processing speed and overall cognition, implying that accumulating brain damage is accompanied by worse cognitive functioning.

  11. Comparison of carotid artery intima - media thickness and risk factors of atherosclerosis in lacunar versus non-lacunar cerebral infarcts

    Directory of Open Access Journals (Sweden)

    Seyed Ali Mousavi

    2007-07-01

    Full Text Available

    BACKGROUND: Increases in the thickness of the intima-media of the carotid artery have been associated with an increased risk of myocardial infarction and stroke in subjects without a history of cardiovascular disease. Lacunar infarcts, one of the most common subtypes of ischemic stroke, show unique pathological and clinicoradiological characteristics. The present study examined the relationship between the vascular risk factors, including carotid artery intimamedia thickness (IMT, and lacunar versus non-lacunar infarcts.
    METHODS: We collected data from patients admitted to hospital with acute ischemic stroke. 195 Patients and 96 control subjects underwent B-mode ultrasonographic measurements of IMT of the common carotid artery. We examined the association of lacunar and non-lacunar infarcts with age, sex, and potential vascular risk factors.
    RESULTS: Of 195 adult patients with acute ischemic stroke, 87 were considered lacunar and 108 were considered nonlacunar strokes. Between these two groups of patients, we did not find a significantly different percentage of diabetes,
    smoking, hypertension, dyslipidemia, myocardial infarction, or previous history of ischemic stroke, alcohol, obesity,
    atherogen diet, exercise, and IMT. However, patients with lacunar infarct, diabetes mellitus (P = 0.02, and hypertension
    (P = 0.02 had a significantly higher percentage of history of prior CVA (P = 0.03 and a significantly higher percentage
    of non-lacunar infarct.
    CONCLUSIONS: The present results indicated that diabetes mellitus and hypertension are more common in patients with lacunar infarcts, and history of CVA is more common in patients with non–lacunar infarcts. We further concluded that IMT cannot differentiate subtypes of ischemic stroke. Because risk factors and clinical presentation of ischemic stroke differ among races, more national studies

  12. Characterization of lacunar defects by positrons annihilation

    CERN Document Server

    Barthe, M F; Blondiaux, G

    2003-01-01

    Among the nondestructive methods for the study of matter, the positrons annihilation method allows to sound the electronic structure of materials by measuring the annihilation characteristics. These characteristics depend on the electronic density as seen by the positon, and on the electron momentums distribution which annihilate with the positon. The positon is sensible to the coulombian potential variations inside a material and sounds preferentially the regions away from nuclei which represent potential wells. The lacunar-type defects (lack of nuclei) represent deep potential wells which can trap the positon up to temperatures close to the melting. This article describes the principles of this method and its application to the characterization of lacunar defects: 1 - positrons: matter probes (annihilation of electron-positon pairs, annihilation characteristics, positrons sources); 2 - positrons interactions in solids (implantation profiles, annihilation states, diffusion and trapping, positon lifetime spec...

  13. Influence of image resolution and evaluation algorithm on estimates of the lacunarity of porous media.

    Science.gov (United States)

    Pendleton, D E; Dathe, A; Baveye, P

    2005-10-01

    In recent years, experience has demonstrated that the classical fractal dimensions are not sufficient to describe uniquely the interstitial geometry of porous media. At least one additional index or dimension is necessary. Lacunarity, a measure of the degree to which a data set is translationally invariant, is a possible candidate. Unfortunately, several approaches exist to evaluate it on the basis of binary images of the object under study, and it is unclear to what extent the lacunarity estimates that these methods produce are dependent on the resolution of the images used. In the present work, the gliding-box algorithm of Allain and Cloitre [Phys. Rev. A 44, 3552 (1991)] and two variants of the sandbox algorithm of Chappard et al. [J. Pathol. 195, 515 (2001)], along with three additional algorithms, are used to evaluate the lacunarity of images of a textbook fractal, the Sierpinski carpet, of scanning electron micrographs of a thin section of a European soil, and of light transmission photographs of a Togolese soil. The results suggest that lacunarity estimates, as well as the ranking of the three tested systems according to their lacunarity, are affected strongly by the algorithm used, by the resolution of the images to which these algorithms are applied, and, at least for three of the algorithms (producing scale-dependent lacunarity estimates), by the scale at which the images are observed. Depending on the conditions under which the estimation of the lacunarity is carried out, lacunarity values range from 1.02 to 2.14 for the three systems tested, and all three of the systems used can be viewed alternatively as the most or the least "lacunar." Some of this indeterminacy and dependence on image resolution is alleviated in the averaged lacunarity estimates yielded by Chappard et al.'s algorithm. Further research will be needed to determine if these lacunarity estimates allow an improved, unique characterization of porous media.

  14. Villus packing density and lacunarity: Markers of placental efficiency?

    Science.gov (United States)

    Shah, R G; Salafia, C M; Girardi, T; Merz, G S

    2016-12-01

    We evaluate, in routine H&E histology slides, villus quantity in a given area (villous packing density, VPD) and the pattern or "gappiness" of villous distribution (lacunarity), and test for correlations with a proxy for fetoplacental metabolic rate, β calculated as (ln (placental weight)/ln (birthweight)) from Kleiber's law [1]. Three ∼4.3 mm(2) images each were obtained from 88 term placentas. Ranges of VPD and lacunarity were each correlated with β (r = 0.31, p = 0.003, r = 0.23, p = 0.03 and respectively). The relationship between β and within-placenta variation in VPD and lacunarity highlights the need to study not merely the mean but the variance of villous geometries and spatial distributions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Fractal zone plates with variable lacunarity.

    Science.gov (United States)

    Monsoriu, Juan; Saavedra, Genaro; Furlan, Walter

    2004-09-06

    Fractal zone plates (FZPs), i.e., zone plates with fractal structure, have been recently introduced in optics. These zone plates are distinguished by the fractal focusing structure they provide along the optical axis. In this paper we study the effects on this axial response of an important descriptor of fractals: the lacunarity. It is shown that this parameter drastically affects the profile of the irradiance response along the optical axis. In spite of this fact, the axial behavior always has the self-similarity characteristics of the FZP itself.

  16. Lacunar strokes: a single institutional experience

    Directory of Open Access Journals (Sweden)

    Osama Shukir Muhammed Amin

    2013-08-01

    Full Text Available Abstract: Objective: Lacunar ischemic strokes comprise approximately 25% of all ischemic strokes. We compared the risk factors and clinical pattern of this type of stroke between males and females. Methods: This observational study involved 50 consecutive patients with their first-ever lacunar stroke and was conducted at the department of neurology of Sulaimaniya general teaching hospital, Iraq from December 1, 2010 to March 1, 2013. Patients’ risk factors, clinical presentation, and strokes’ patterns were noted and a comparison was made between males and females. Results: Males (64% outnumbered females (36% with a male to female ration of 1.7. The mean age of males was 63 years while it was 61 years in females. Although hypertension was more common in females than in males, diabetes and smoking were more common in the latter group; however, there were no statistically significant differences between the 2 genders in terms of hypertension (P-value <0.3 and diabetes (P-value < 0.07 while smoking was strongly associated with male gender (P-value<0.0001. Pure motor hemiparesis, ataxic hemiparesis, pure sensory stroke, and dysarthria-clumsy hand syndrome were more common in males; only senori-motor stroke revealed a statistically significant difference in favor males (P-value<0.0001; 95% CI -1.7 to 19.2. There was no statistically significant difference in terms of which side of the brain was infarcted between males and females (P-value<0.4. Conclusion: Males around the age of 63 years were the main target for these lacunar strokes. Cigarette smoking and sensorimotor strokes were significantly associated with male gender. [Cukurova Med J 2013; 38(4.000: 659-666

  17. Association of Notch3 single-nucleotide polymorphisms and lacunar infarctions in patients

    Science.gov (United States)

    LI, YING; LIU, NAN; CHEN, HUI; HUANG, YONGHUA; ZHANG, WEIWEI

    2016-01-01

    Cerebrovascular disease is a leading cause of morbidity and mortality worldwide, which is influenced by genetic and environmental factors. The aim of the present study was to examine the association between single-nucleotide polymorphisms (SNPs) in Notch3 exons 3–6 and lacunar infarction by comparing SNPs between control subjects and those with lacunar infarction. A single-center case-control study was conducted to investigate the association between Notch3 SNPs and risk of stroke. A total of 140 patients were included in the study, 30 of whom had no infarction (control) and 110 had lacunar infarction. Lacunar patients were divided into the ‘pure lacunar’ and ‘lacunar + leukoarasis’ groups based on brain imaging. All the patients were of Chinese Han ethnicity, and the male to female ratio was 84:56. Patient clinical histories included hypertension, diabetes mellitus (DM), hyperlipidemia, and heart disease were recorded. The Notch3 sequence was obtained from the National Centser for Biotechnology Information database. Notch3 was amplified by polymerase chain reaction from whole blood samples, and exons 3–6 were sequenced to identify SNPs. The result showed that there was no significant difference in the prevalence of hypertension, DM, hyperlipidemia, and heart disease between the control and lacunar infarction patients. Notabley, the age of the lacunar + leukoarasis patients was significantly higher than that of the control and pure lacunar patients (P<0.05). Eight SNPs were detected at low frequencies, and only rs3815388 and rs1043994 exhibited slightly higher frequencies. A χ2 test indicated that Notch3 SNPs, particularly rs1043994, were associated with lacunar infarction (P<0.05). In conclusion, the result of the present study have shown that Notch3 SNPs, particularly rs1043994, are associated with lacunar infarction. PMID:26889213

  18. Lacunarity analysis of spaceborne radar image texture for rock unit discrimination

    Science.gov (United States)

    Dong, Pinliang

    Fractal geometry has led to new understanding of many natural objects and phenomena. As a scale-dependent measure, lacunarity can be used to discriminate different textures that may not be differentiated by fractal dimension. Based on a differential box counting method and a gliding-box algorithm, a new lacunarity estimation method is developed for texture analysis of digital images, and a "Lacunarity Analysis" extension built for ArcView (ESRI) geographical information system software. To reveal the directional properties of textures, the directionality of lacunarity is also defined. The new lacunarity measure is evaluated through quantitative comparison with the Voss lacunarity, the binary lacunarity, the grey level cooccurrence matrix (GLCM) based texture measures (homogeneity, contrast, dissimilarity, entropy), the fractal dimension, and the min-max operator using Brodatz textures. The results from Brodatz textures suggest that the new lacunarity estimation method for grey-scale images provides more accurate texture measurements than the above-mentioned fractal-based and statistical texture measures. In comparison with the Voss lacunarity, the fractal dimension, and the GLCM-based texture measures, the new lacunarity measure is then applied to dual-band (L and C) and dual-polarization (HH and HV) Shuttle Imaging Radar (SIR-C), and C-band HH polarization Radarsat images of two imaging modes for rock unit discrimination in a study area between California and Arizona, USA. Using textural analysis of 36 SIR-C and Radarsat sub-images and classification accuracy assessment of the combined Landsat Thematic Mapper (TM) images and spaceborne radar textural feature images, it has been demonstrated that the new lacunarity measure outperformed other texture measures in comparison, and the L-band HH polarization SIR-C image provides more textural information of the rock units compared with the Radarsat and other SIR-C radar images used in this study. The study shows that

  19. The correlation between cognitive function and cerebral white matter lesions/insulin resistance in patients with lacunar infarction:a clinical study of 184 cases

    Institute of Scientific and Technical Information of China (English)

    张琼予

    2013-01-01

    Objective To investigate the correlation between cognitive function and cerebral white matter lesions(WML)/insulin resistance(IR) in patients with stroke.Methods Between May 2011 and October 2011,the clin-ical data of 184 in-patients with lacunar infarction were

  20. Lacunar infarction:a hemodynamic analysis of 102 cases

    Institute of Scientific and Technical Information of China (English)

    张春玲

    2006-01-01

    Objective To study cerebrovascular lesion and lacunar infarction (LI) and to explore the pathogenesis of LI based on neuroradiological imaging. Methods Brain MRI,CT angiography (CTA) and CT perfusion (CTP) were performed in all 102 patients with LI. Results MRI showed single LI in 3 cases, multiple LI in 99 cases. CTA showed severe stenosis or occlusion of internal

  1. Alterations of mass density and 3D osteocyte lacunar properties in bisphosphonate-related osteonecrotic human jaw bone, a synchrotron µCT study.

    Directory of Open Access Journals (Sweden)

    Bernhard Hesse

    Full Text Available Osteonecrosis of the jaw, in association with bisphosphonates (BRONJ used for treating osteoporosis or cancer, is a severe and most often irreversible side effect whose underlying pathophysiological mechanisms remain largely unknown. Osteocytes are involved in bone remodeling and mineralization where they orchestrate the delicate equilibrium between osteoclast and osteoblast activity and through the active process called osteocytic osteolysis. Here, we hypothesized that (i changes of the mineralized tissue matrix play a substantial role in the pathogenesis of BRONJ, and (ii the osteocyte lacunar morphology is altered in BRONJ. Synchrotron µCT with phase contrast is an appropriate tool for assessing both the 3D morphology of the osteocyte lacunae and the bone matrix mass density. Here, we used this technique to investigate the mass density distribution and 3D osteocyte lacunar properties at the sub-micrometer scale in human bone samples from the jaw, femur and tibia. First, we compared healthy human jaw bone to human tibia and femur in order to assess the specific differences and address potential explanations of why the jaw bone is exclusively targeted by the necrosis as a side effect of BP treatment. Second, we investigated the differences between BRONJ and control jaw bone samples to detect potential differences which could aid an improved understanding of the course of BRONJ. We found that the apparent mass density of jaw bone was significantly smaller compared to that of tibia, consistent with a higher bone turnover in the jaw bone. The variance of the lacunar volume distribution was significantly different depending on the anatomical site. The comparison between BRONJ and control jaw specimens revealed no significant increase in mineralization after BP. We found a significant decrease in osteocyte-lacunar density in the BRONJ group compared to the control jaw. Interestingly, the osteocyte-lacunar volume distribution was not altered after

  2. Multifractal and lacunarity analysis of microvascular morphology and remodeling.

    Science.gov (United States)

    Gould, Daniel J; Vadakkan, Tegy J; Poché, Ross A; Dickinson, Mary E

    2011-02-01

    Classical measures of vessel morphology, including diameter and density, are employed to study microvasculature in endothelial membrane labeled mice. These measurements prove sufficient for some studies; however, they are less well suited for quantifying changes in microcirculatory networks lacking hierarchical structure. We demonstrate that automated multifractal analysis and lacunarity may be used with classical methods to quantify microvascular morphology. Using multifractal analysis and lacunarity, we present an automated extraction tool with a processing pipeline to characterize 2D representations of 3D microvasculature. We apply our analysis on four tissues and the hyaloid vasculature during remodeling. We found that the vessel networks analyzed have multifractal geometries and that kidney microvasculature has the largest fractal dimension and the lowest lacunarity compared to microvasculature networks in the cortex, skin, and thigh muscle. Also, we found that, during hyaloid remodeling, there were differences in multifractal spectra reflecting the functional transition from a space filling vasculature which nurtures the lens to a less dense vasculature as it regresses, permitting unobstructed vision. Multifractal analysis and lacunarity are valuable additions to classical measures of vascular morphology and will have utility in future studies of normal, developing, and pathological tissues. © 2011 John Wiley & Sons Ltd.

  3. Fractal dimension and lacunarity analysis of dental radiographs.

    Science.gov (United States)

    Yasar, F; Akgünlü, F

    2005-09-01

    As the occlusal forces transmitted to the jaw bones during mastication might be different in dentate and edentulous regions, there might be different radiographical trabecular bone texture in these regions. Image analysis procedures are promising techniques which are used to detect structural changes of bone texture on radiographs. In this study, the differences of fractal dimension (FD) and lacunarity measurements of radiographical trabecular bone between dentate and edentulous regions were investigated. Direct digital radiographs of premolar-molar region were taken from 51 patients who were included in our study. Two rectangular regions of interest (ROIs) with the same dimensions (37x119 pixels) were created on these radiographs; one in the edentulous region and the other one in the dentate region. The ROIs were segmented as black and white areas. Box-counting fractal dimension and lacunarity of these regions were calculated. Paired samples t-test and Pearson correlation coefficients were calculated. It was found that there were differences between dentate and edentulous regions for FD and lacunarity (P=0.000). There is a negative correlation between FD and lacunarity (-0.643, Placunarity and dentate and edentulous regions (-0.541, Placunarity can reveal these alterations quantitatively.

  4. Lacunarity and intermittency in fluid turbulence

    Science.gov (United States)

    Smith, L. A.; Fournier, J.-D.; Spiegel, E. A.

    1986-01-01

    It is shown that oscillations in the high-order moments of turbulent velocity fields are inherent to the fractal character of intermittent turbulence and are a feature of the lacunarity of fractal sets. Oscillations in simple Cantor sets are described, and a single parameter to measure lacunarity is identified. The connection between oscillations in fractals and in the turbulent velocity correlations is discussed using the phenomenological beta model of intermittent turbulence (Frisch et al., 1978).

  5. Polyadic Cantor superlattices with variable lacunarity.

    Science.gov (United States)

    Jaggard, D L; Jaggard, A D

    1997-02-01

    Reflection and transmission properties of polyadic fractal superlattices are formulated, solved analytically, and characterized for variations in stage of growth, fractal dimension, and lacunarity. This is the first time to our knowledge that the effect of lacunarity on wave interactions with such structures has been considered. The results are summarized by families of reflection data that we denote twist plots. A new doubly recursive computational technique efficiently provides the reflection and transmission coefficients for a large class of Cantor superlattices with numerous interfaces.

  6. Risk Factors for Silent Lacunar Infarction in Patients with Transient Ischemic Attack

    Science.gov (United States)

    Li, Ying; Liu, Nan; Huang, Yonghua; Wei, Wei; Chen, Fei; Zhang, Weiwei

    2016-01-01

    Background Lacunar infarctions represent 25% of ischemic strokes. Lacunar stroke and transient ischemic attack (TIA) share a number of symptoms. This study aimed to assess the potential risk factors for lacunar infarction in patients with TIA. Material/Methods This was a retrospective study performed at the Beijing Military General Hospital in patients with TIA admitted between March 2010 and December 2011. Patients were grouped according to lacunar vs. no lacunar infarction. All patients were diagnosed using diffusion-weighted imaging (DWI) on brain magnetic resonance imaging (MRI). Brain angiography (computed tomography and MRI) was used to measure intracranial stenosis. Carotid artery stenosis was measured by ultrasound. Results Patients with TIA and lacunar infarction (n=298) were older than those without lacunar infarction (n=157) (69.4±10.0 vs. 58.9±9.0 years, P<0.001) and showed a higher frequency of males (51.7% vs. 41.4%, P=0.037), hypertension (75.3% vs. 45.9%, P<0.001), diabetes (32.6% vs. 21.0%, P=0.010), hyperlipidemia (53.4% vs. 29.3%, P<0.001), carotid stenosis (73.2% vs. 40.1%, P<0.001), and intracranial stenosis (55.6% vs. 31.9%, P<0.001), but a lower frequency of alcohol drinking (8.1% vs. 14.0%, P=0.045). Lacunar infarction mostly involved the anterior circulation (62.8%). Multivariate analysis showed that age (odds ratio (OR)=1.085, 95% confidence interval (95%CI): 1.054–1.117, P<0.001), hypertension (OR=1.738, 95%CI: 1.041–2.903, P=0.035), hyperlipidemia (OR=2.169, 95%CI: 1.307–3.601, P=0.003), and carotid stenosis (OR=1.878, 95%CI: 1.099–3.206, P=0.021) were independently associated with lacunar infarction. Conclusions Age, hypertension, hyperlipidemia, and carotid stenosis were independently associated with silent lacunar infarction in patients with TIA. PMID:26864634

  7. The use of susceptibility-weighted imaging to detect cerebral microbleeds after lacunar infarction.

    Science.gov (United States)

    Shao, L; Wang, M; Ge, X-H; Huang, H-D; Gao, L; Qin, J-C

    2017-07-01

    To study the value of susceptibility-weighted imaging (SWI) technology to detect cerebral microbleeds (CMBs) in senile cerebral lacunar infarction patients; and to evaluate the complicated cerebral hemorrhage risk after patients with CMBs took aspirin, an antiplatelet medication or received anticoagulant therapy. MRI scanning, using GRE-T2*WI, SWI and FSE sequences (T1WI, T2WI, and T2FLAIR), was performed on the three groups: (1) a cerebral lacunar infarction group; (2) cerebral lacunar infarction with cerebral microbleeds (CMBs) group; and (3) a healthy elderly group. A total of 60 cases were in each group (180 total patients). In addition, the lacunar infarction group and lacunar infarction with CMBs groups were both treated with formal antiplatelet or anticoagulant therapy, according to medical guidelines. Patients were followed for 12 months, during which time their cerebral hemorrhages and post-event effects were observed. The relativity of CMBs, antiplatelet therapy, anticoagulant therapy and cerebral hemorrhage transformation was analyzed and defined. The two groups of research patients with lacunar infarctions were scanned with relevant sequences. The SWI scanning sequence showed the highest positive rate of CMBs, followed by GRE-T2*WI and other conventional scanning sequences. T1WI, T2WI and T2FLAIR showed a relatively lower positive rate of CMBs. In the cerebral lacunar infarction group and healthy elderly group, 34 cases in the SWI sequence showed 84 positive sites; 18 cases in the GRE-T2*WI sequence showed 40 positive sites; 2 cases in the T1WI sequence showed 4 positive sites; and 6 cases in the T2WI sequence showed 11 positive sites. After a chi-squared test, the differences between the sequences were statistically significant (p CMBs. The normal control group only showed mild hemorrhaging. The degree of lacunar infarction was significantly related to the severity of CMBs (p CMBs had received formal antiplatelet therapy and anticoagulation therapy

  8. Fractal analysis: fractal dimension and lacunarity from MR images for differentiating the grades of glioma.

    Science.gov (United States)

    Smitha, K A; Gupta, A K; Jayasree, R S

    2015-09-07

    Glioma, the heterogeneous tumors originating from glial cells, generally exhibit varied grades and are difficult to differentiate using conventional MR imaging techniques. When this differentiation is crucial in the disease prognosis and treatment, even the advanced MR imaging techniques fail to provide a higher discriminative power for the differentiation of malignant tumor from benign ones. A powerful image processing technique applied to the imaging techniques is expected to provide a better differentiation. The present study focuses on the fractal analysis of fluid attenuation inversion recovery MR images, for the differentiation of glioma. For this, we have considered the most important parameters of fractal analysis, fractal dimension and lacunarity. While fractal analysis assesses the malignancy and complexity of a fractal object, lacunarity gives an indication on the empty space and the degree of inhomogeneity in the fractal objects. Box counting method with the preprocessing steps namely binarization, dilation and outlining was used to obtain the fractal dimension and lacunarity in glioma. Statistical analysis such as one-way analysis of variance and receiver operating characteristic (ROC) curve analysis helped to compare the mean and to find discriminative sensitivity of the results. It was found that the lacunarity of low and high grade gliomas vary significantly. ROC curve analysis between low and high grade glioma for fractal dimension and lacunarity yielded 70.3% sensitivity and 66.7% specificity and 70.3% sensitivity and 88.9% specificity, respectively. The study observes that fractal dimension and lacunarity increases with an increase in the grade of glioma and lacunarity is helpful in identifying most malignant grades.

  9. Tunneling in quantum superlattices with variable lacunarity

    Energy Technology Data Exchange (ETDEWEB)

    Villatoro, Francisco R. [Departamento de Lenguajes y Ciencias de la Computacion, Universidad de Malaga, E-29071 Malaga (Spain); Monsoriu, Juan A. [Departamento de Fisica Aplicada, Universidad Politecnica de Valencia, E-46022 Valencia (Spain)], E-mail: jmonsori@fis.upv.es

    2008-05-19

    Fractal superlattices are composite, aperiodic structures comprised of alternating layers of two semiconductors following the rules of a fractal set. The scattering properties of polyadic Cantor fractal superlattices with variable lacunarity are determined. The reflection coefficient as a function of the particle energy and the lacunarity parameter present tunneling curves, which may be classified as vertical, arc, and striation nulls. Approximate analytical formulae for such curves are derived using the transfer matrix method. Comparison with numerical results shows good accuracy. The new results may be useful in the development of band-pass energy filters for electrons, semiconductor solar cells, and solid-state radiation sources up to THz frequencies.

  10. Tug-of-war lacunarity-A novel approach for estimating lacunarity.

    Science.gov (United States)

    Reiss, Martin A; Lemmerer, Birgit; Hanslmeier, Arnold; Ahammer, Helmut

    2016-11-01

    Modern instrumentation provides us with massive repositories of digital images that will likely only increase in the future. Therefore, it has become increasingly important to automatize the analysis of digital images, e.g., with methods from pattern recognition. These methods aim to quantify the visual appearance of captured textures with quantitative measures. As such, lacunarity is a useful multi-scale measure of texture's heterogeneity but demands high computational efforts. Here we investigate a novel approach based on the tug-of-war algorithm, which estimates lacunarity in a single pass over the image. We computed lacunarity for theoretical and real world sample images, and found that the investigated approach is able to estimate lacunarity with low uncertainties. We conclude that the proposed method combines low computational efforts with high accuracy, and that its application may have utility in the analysis of high-resolution images.

  11. Multifractal spectrum and lacunarity as measures of complexity of osseointegration.

    Science.gov (United States)

    de Souza Santos, Daniel; Dos Santos, Leonardo Cavalcanti Bezerra; de Albuquerque Tavares Carvalho, Alessandra; Leão, Jair Carneiro; Delrieux, Claudio; Stosic, Tatijana; Stosic, Borko

    2016-07-01

    The goal of this study is to contribute to a better quantitative description of the early stages of osseointegration, by application of fractal, multifractal, and lacunarity analysis. Fractal, multifractal, and lacunarity analysis are performed on scanning electron microscopy (SEM) images of titanium implants that were first subjected to different treatment combinations of i) sand blasting, ii) acid etching, and iii) exposition to calcium phosphate, and were then submersed in a simulated body fluid (SBF) for 30 days. All the three numerical techniques are applied to the implant SEM images before and after SBF immersion, in order to provide a comprehensive set of common quantitative descriptors. It is found that implants subjected to different physicochemical treatments before submersion in SBF exhibit a rather similar level of complexity, while the great variety of crystal forms after SBF submersion reveals rather different quantitative measures (reflecting complexity), for different treatments. In particular, it is found that acid treatment, in most combinations with the other considered treatments, leads to a higher fractal dimension (more uniform distribution of crystals), lower lacunarity (lesser variation in gap sizes), and narrowing of the multifractal spectrum (smaller fluctuations on different scales). The current quantitative description has shown the capacity to capture the main features of complex images of implant surfaces, for several different treatments. Such quantitative description should provide a fundamental tool for future large scale systematic studies, considering the large variety of possible implant treatments and their combinations. Quantitative description of early stages of osseointegration on titanium implants with different treatments should help develop a better understanding of this phenomenon, in general, and provide basis for further systematic experimental studies. Clinical practice should benefit from such studies in the long

  12. Clinical predictors of hemorrhagic transformation in non lacunar ischemic stroke

    Directory of Open Access Journals (Sweden)

    Natalia R. Balian

    2017-04-01

    Full Text Available Hemorrhagic transformation is a complex phenomenon where brain tissue bleeds, which could be associated or not to an increase in the neurological deficit after the acute ischemic stroke. The aim of our study was to evaluate clinical predictors of hemorrhagic transformation in patients with non-lacunar ischemic stroke. We performed a prospective analysis of the clinical records and images of patients with non-lacunar ischemic stroke. Demographics, vascular risk factors, previous medications and the information of the event in patients with and without hemorrhagic transformation were here compared. We included in this study 747 patients with non-lacunar stroke, the mean age was 77 ± 11 years and 61% were females. In the univariate analysis, the age, a history of hypertension, atrial fibrillation, chronic kidney disease and the previous use of oral anticoagulation resulted statistically significant. In the multivariate analysis of logistic regression adjusted by age and vascular risk factors: the age > 80 years (OR 3.6, CI 95% 1.8-7.6, the pulse pressure > 60 mmHg at admission (OR 5.3, CI 95% 3.2-9.1, the chronic kidney disease (OR 3, CI 95% 2.5-3.8 and the presence of previous atrial fibrillation (OR 3.5, CI 95% 2.1-6.1 were associated with and increased risk of hemorrhagic transformation. The predictors of hemorrhagic transformation in our cohort showed a relationship with severe vascular illness. The identification of these patients could influence therapeutic decisions that could increase the risk of hemorrhagic transformation

  13. Levy dusts, Mittag-Leffler statistics, mass fractal lacunarity, and perceived dimension

    Energy Technology Data Exchange (ETDEWEB)

    Blumenfeld, R. [Theoretical Division and CNLS, Mail Stop B262, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Mandelbrot, B.B. [Mathematics Department, Yale University, New Haven, Connecticut 06520-8283 (United States)

    1997-07-01

    We study the Levy dusts on the line on two accounts: the fluctuations around the average power law that characterizes the mass-radius relation for self-similar fractals, and the statistics of the intervals between strides along the logarithmic axis (their tail distribution is related to the dust`s fractal dimension). The Levy dusts are suggested as a yardstick of neutral lacunarity, against which non-neutral lacunarity can be measured objectively. A notion of perceived dimension is introduced. We conclude with an application of the Mittag-Leffler statistics to a nonlinear electrical network. {copyright} {ital 1997} {ital The American Physical Society}

  14. Fibrous Dysplasia Characterization Using Lacunarity Analysis.

    Science.gov (United States)

    Cordeiro, Mirna S; Backes, André R; Júnior, Antônio F Durighetto; Gonçalves, Elmar H G; de Oliveira, Jefferson X

    2016-02-01

    Fibrous dysplasia (FD) is a developmental anomaly in which the normal medullary space of the affected bone is replaced by fibro-osseous tissue. This condition is typically encountered in adolescents and young adults. It affects the maxillofacial region and it can often cause severe deformity and asymmetry. Therefore, accurate diagnosis is critical to determine the appropriate treatment of each case. In this sense, computed tomography (CT) is a relevant resource among the imaging techniques for correct diagnosis of this condition. Thus, in this paper, we propose to analyze fibrous dysplasia through its texture pattern. To accomplish this task, we propose to use lacunarity analysis, a multiscale method for describing patterns of spatial dispersion. Results indicated lower lacunarity values for fibrous dysplasia in comparison to normal bone samples, an indication that their texture images are more homogeneous, and a high separability between the classes when using principal component analysis (PCA) and decision trees for statistical analysis.

  15. Lacunarity Definition For Ramified Data Sets Based On Optimal Cover

    Energy Technology Data Exchange (ETDEWEB)

    Tolle, Charles Robert; Rohrbaugh, David Thomas; Timothy R. McJunkin

    2003-05-01

    Lacunarity is a measure of how data fills space. It complements fractal dimension, which measures how much space is filled. This paper discusses the limitations of the standard gliding box algorithm for calculating lacunarity, which leads to a re-examination of what lacunarity is meant to describe. Two new lacunarity measures for ramified data sets are then presented that more directly measure the gaps in a ramified data set. These measures are rigorously defined. An algorithm for estimating the new lacunarity measure, using Fuzzy-C means clustering algorithm, is developed. The lacunarity estimation algorithm is used to analyze two- and three-dimensional Cantor dusts. Applications for these measures include biological modeling and target detection within ramified data sets.

  16. Self-referred approach to lacunarity.

    Science.gov (United States)

    Rodrigues, Erbe P; Barbosa, Marconi S; Costa, Luciano da F

    2005-07-01

    This paper describes an approach to lacunarity which adopts the pattern under analysis as the reference for the sliding window procedure. The superiority of such a scheme with respect to more traditional methodologies, especially when dealing with finite-size objects, is established and illustrated through applications to diffusion limited aggregation pattern characterization. It is also shown that, given the enhanced accuracy and sensitivity of this scheme, the shape of the window becomes an important parameter, with advantage for circular windows.

  17. Correlation Study of Lacunar Infarction with Leukoaraiosis and Diabetes%伴腔隙性脑梗死的脑白质疏松症与糖尿病的相关性

    Institute of Scientific and Technical Information of China (English)

    陈瑾; 王丽娟; 刘欣; 王红霞

    2016-01-01

    Objective:To investigate the correlation study of lacunar infarction with leukoaraiosis and diabetes.Method:A total of 200 patients who admitted in the Department of Neurology,our hospital form August 2013 to August 2015 were divided into leukoaraiosis with diabetes group(the experiment group,n=100) and leukoaraiosis with-no diabetes group(the control group,n=100) according to their cerebral MRI findings and glucose levels.Result:The severity levels of leukoaraiosis in the experiment group more exceed than that of the control group(P<0.001).The grade of leukoaraiosis by Fazekas had a positive correlation with high blood sugar levels in diabtes patients.Conclusion:Leukoaraiosis is associated with diabets inpatients with lacunar infarction.%目的:研究伴腔隙性脑梗死患者脑白质疏松症的严重程度与糖尿病的相关性。方法:选择2013年8月-2015年8月在本院神经内科住院患者,经头颅核磁确诊为腔隙性脑梗死合并脑白质疏松患者200例为研究对象,伴腔隙性脑梗死的脑白质疏松症合并糖尿病患者为试验组,伴腔隙性脑梗死的脑白质疏松症非糖尿病患者为对照组,研究两组脑白质疏松的严重程度与糖尿病的相关性。结果:试验组的白质疏松严重程度明显高于对照组,差异有统计学意义(P<0.001)。脑白质疏松Fazekas评分分值与糖尿病患者血糖升高呈正相关。结论:伴腔隙性脑梗死的脑白质疏松的发生与糖尿病有一定相关性。

  18. Lacunarity and multifractal analysis of the large DLA mass distribution

    Science.gov (United States)

    Rodriguez-Romo, Suemi; Sosa-Herrera, Antonio

    2013-08-01

    We show the methodology used to analyze fractal and mass-multifractal properties of very large Diffusion-Limited Aggregation (DLA) clusters with a maximum of 109 particles for 2D aggregates and 108 particles for 3D clusters, to support our main result; the scaling behavior obtained by our experimental results corresponds to the expected performance of monofractal objects. In order to estimate lacunarity measures for large DLA clusters, we develop a variant of the gliding-box algorithm which reduces the computer time needed to obtain experimental results. We show how our mass multifractal data have a tendency to present monofractal behavior for the mass distribution of the cases presented in this paper in the limit of very large clusters. Lacunarity analysis shows, provided we study small clusters mass distributions, data which might be interpreted as two different values of fractal dimensions while the cluster grows; however, this effect tends to vanish when the cluster size increases further, in such a way that monofractality is achieved. The outcomes of this paper lead us to conclude that the previously reported mass multifractality behavior (Vicsek et al., 1990 [13]) detected for DLA clusters is a consequence of finite size effects and floating point precision limitations and not an intrinsic feature of the phenomena, since the scaling behavior of our DLA clusters space corresponds to monofractal objects, being this situation remarkably noticeable in the limit of very large clusters.

  19. On the Relation Between Lacunarity and Fractal Dimension

    Science.gov (United States)

    Borys, P.

    2009-05-01

    I discuss the relation between fractal dimension and lacunarity. Commenting the known results, I propose a method for estimation of the scaling constant in the power law dependency. Additionally, I provide a simple new derivation of a known experimental relation for lacunarity and fractal dimension.

  20. Lacunarity analysis of spatial pattern in CT images of vertebral trabecular bone for assessing osteoporosis.

    Science.gov (United States)

    Dougherty, Geoffrey; Henebry, Geoffrey M

    2002-03-01

    The structural integrity of vertebral trabecular bone is determined by the continuity of its trabecular network and the size of the holes comprising its marrow space, both of which determine the apparent size of the marrow spaces in a transaxial CT image. A model-independent assessment of the trabeculation pattern was determined from the lacunarity of thresholded CT images. Using test images of lumbar vertebrae from human cadavers, acquired at different slice thicknesses, we determined that both median thresholding and local adaptive thresholding (using a 7 x 7 window) successfully segmented the grey-scale images. Lacunarity analysis indicated a multifractal nature to the images, and a range of marrow space sizes with significant structure around 14-18 mm(2). Preliminary studies of in vivo images from a clinical CT scanner indicate that lacunarity analysis can follow the pattern of bone loss in osteoporosis by monitoring the homogeneity of the marrow spaces, which is related to the connectivity of the trabecular bone network and the marrow space sizes. Although the patient sample was small, derived parameters such as the maximum deviation of the lacunarity from a neutral (fractal) model, and the maximum derivative of this deviation, seem to be sufficiently sensitive to distinguish a range of bone conditions. Our results suggest that these parameters, used with bone mineral density values, may have diagnostic value in characterizing osteoporosis and predicting fracture risk.

  1. An interactive mapping tool for visualizing lacunarity of laser scanned point clouds

    Science.gov (United States)

    Kania, Adam; Székely, Balázs

    2016-04-01

    Lacunarity, a measure of the spatial distribution of the empty space in a certain model or real space over large spatial scales, is found to be a useful descriptive quantity in many fields using imagery, including, among others, geology, dentistry, neurology. Its application in ecology was suggested more than 20 years ago. The main problem of its application was the lack of appropriate high resolution data. Nowadays, full-waveform laser scanning, also known as FWF LiDAR, provides the tool for mapping the vegetation in unprecedented details and accuracy. Consequently, the lacunarity concept can be revitalized, in order to study the structure of the vegetation in this sense as well. Calculation of lacunarity, even if it is done in two dimensions (2D), is still has its problems: on one hand it is a number-crunching procedure, on the other hand, it produces 4D results: at each 3D point it returns a set of data that are function of scale. These data sets are difficult to visualize, to evaluate, and to compare. In order to solve this problem, an interactive mapping tool has been conceptualized that is designed to manipulate and visualize the data, lets the user set parameters for best visualization or comparison results. The system is able to load large amounts of data, visualize them as lacunarity curves, or map view as horizontal slices or in 3D point clouds coloured according to the user's choice. Lacunarity maps are presented as a series of (usually) horizontal profiles, e.g. rasters, which cells contain color-mapped values of selected lacunarity of the point cloud. As lacunarity is usually analysed in a series of successive windows sizes, the tool can show a series of rasters with sequentially animated lacunarity maps calculated for various window sizes. A very fast switching of colour schemes is possible to facilitate rapid visual feedback to better understand underlying data patterns exposed by lacunarity functions. In the comparison mode, two sites (or two areas

  2. An Efficient Implementation of the Gliding Box Lacunarity Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Charles R. Tolle,; Timothy R. McJunkin; David J. Gorsich

    2008-03-01

    Lacunarity is a measure of how data fills space. It complements fractal dimension, which measures how much space is filled. Currently, many researchers use the gliding box algorithm for calculating lacunarity. This paper introduces a fast algorithm for making this calculation. The algorithm presented is akin to fast box counting algorithms used by some researchers in estimating fractal dimension. A simplified gliding box measure equation along with key pseudo code implementations for the algorithm are presented. Applications for the gliding box lacunarity measure have included subjects that range from biological community modeling to target detection.

  3. A lacunarity-based approach to evaluate Martian surfaces

    Science.gov (United States)

    Székely, Balázs; Kania, Adam; Magyar, Zoltán

    2016-04-01

    Terrestrial planets show great variety in terms of geomorphological patterns: the surface is shaped on one hand by the various phases of asteroid bombardment, on the other hand internal and external processes create or have created landform elements at various scales. This richness in forms have already been considered in terms of fractal or multifractal analyses, resulting in various considerations. However, so far the counterpart of the fractal analysis, the lacunarity analysis has been seldom carried out. Lacunarity, a measure of the spatial distribution of the empty space in a certain model or real space over large spatial scales, is found to be a useful descriptive quantity in many fields using imagery. Lacunarity can be calculated in various dimensions; in most of the cases 2D calculation is performed. Our project also aims at calculating 2D lacunarity curves, however, we also use digital terrain models (DTMs) of the planet Mars, introducing partly the third dimension into the calculation. DTMs are converted to horizontal slices of the topography and these slices are then treated as images. The lacunarity analysis is performed on these stacks of images resulting in large amount of lacunarity curves. These curves can be compared locally or regionally, and the set of curves can be used for more global comparisons. Our preliminary results show that characteristic differences can be detected between various Martian surface types, i.e. the lacunarity results, similar to fractal dimensions, have a certain descriptive power. As this type of lacunarity analysis provide larger amount of descriptors (multiple lacunarity functions) than the fractal dimension values and the scale of analysis (area of interest taken into account in the computing) can be selected according to the needs, it seems to be possible to create lacunarity libraries for general use. In this preliminary phase of the project tools and techniques are tested to compare effectively the resulting

  4. Correlative factors of cognitive impairment in patients with lacunar infarcts

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Patients with lacunar infarcts are thought tohave an increased risk of cognitive i mpair ment anddementia[1].Cognitive i mpair ment is a predictor ofpoor functional outcome in stroke survivors[2].However,in patients with lacunar infarcts,thepathway leading to cognitive i mpair ment is notclear.According to the lacunar hypothesis,cogni-tive i mpair ment results fromincreased number andvolume of lacunes,especially whenlocated strategi-cally within frontal subcortical loops[3];while Feinet al[4]found that cogn...

  5. Fractal Dimension and Lacunarity analysis of mammographic patterns in assessing breast cancer risk related to HRT treated population

    DEFF Research Database (Denmark)

    Karemore, Gopal Raghunath; Nielsen, Mads

    2009-01-01

      Structural texture measures are used to address the aspect of breast cancer risk assessment in screening mammograms. The current study investigates whether texture properties characterized by local Fractal Dimension (FD) and Lacunarity contribute to asses breast cancer risk. FD represents...... the complexity while the Lacunarity characterize the gappiness of a fractal. Our cross-sectional case-control study includes mammograms of 50 patients diagnosed with breast cancer in the subsequent 2-4 years and 50 matched controls. The longitudinal double blind placebo controlled HRT study includes 39 placebo...... and 36 HRT treated volunteers for two years. ROIs with same dimension (250*150 pixels) were created behind the nipple region on these radiographs. Box counting method was used to calculate the fractal dimension (FD) and the Lacunarity. Paired t-test and Pearson correlation coefficient were calculated...

  6. Prospective study of disturbance of intelligence of patients with lacunar stroke%腔隙性脑梗死患者智能障碍的前瞻性研究

    Institute of Scientific and Technical Information of China (English)

    陈湛愔; 陈逢俭; 梁秀竹

    2003-01-01

    Aim To find the regularity of disturbance of intelligence through prospective study of patients with lacunar stroke.Methods 186 patients with lacunar stroke recruited in Department of Neurology of Affiliated Central Hospital of Guangdong Medical College entered this study,51 cases were combined with slight aphemia and most of them achieved obvious improvement within one week after hopitalization,and aphasis was not seen in others.The symptoms of limb paralysis of all the patients were slight and the muscular strengths were all above grade IV,which were improved obviously within one week.Then all the 186 cases were measured with adult intelligence table and multiple correlation analysis was done according to sex,age,job and education extent of patients and image characteristics.Results The intelligence of 130 patients with lacunar stroke was lower than normal and accounted for 70% of 186 cases.51 cases belonged to severe disturbance of intelligence(VIQ< 69) and accounted for 27.4% .The relationship between education extent and disturbance of intelligence presented significant negative correlation(r=-0.6307,P=0.001).The cerebral infarction in left - side basal ganglion,area of corona radiata and left - side temporal lobe could easily cause disturbance of intelligence(r=-0.217,P=0.003) than right side.Binswanger syndrome was the important reason leading to disturbance of intelligence(r=-0.2677,P< 0.001).Conclusion Different lesion locus often leads to obviously different extent of disturbance of intelligence.Left hemisphere lesion could easily cause disturbance of intelligence,especially left basal ganglion and temporal lobe.The disturbance of intelligence of patients with multiple locus is severer than that with single locus.In addition,single infracortical cava stroke can cause obvious disturbance of intelligence.The disturbance of intelligence caused by sex,age and job has no correlation with that caused by infracortical cava stroke,but it presents negative

  7. Lacunarity as a novel measure of cancer cells behavior.

    Science.gov (United States)

    Borys, Przemyslaw; Krasowska, Monika; Grzywna, Zbigniew J; Djamgoz, Mustafa B A; Mycielska, Maria E

    2008-12-01

    An important goal in many branches of science, especially in molecular biology and medicine is the quantitative analysis of the structures and their morphology. The morphology can be analyzed in many ways, in particular by the fractal analysis. Apart from the fractal dimension, an important part of the fractal analysis is the lacunarity measurement which, roughly speaking, characterizes the distribution of gaps in the fractal: a fractal with high lacunarity has large gaps. In this paper, we present an extension of the lacunarity measure to objects with nonregular shapes that enables us to provide a successful discrimination of cancer cell lines. The cell lines differ in the shape of vacuole (the gaps in their body) which is perfectly suited for the lacunarity analysis.

  8. Multifractal Scaling of Grayscale Patterns: Lacunarity and Correlation Dimension

    Science.gov (United States)

    Roy, A.; Perfect, E.

    2012-12-01

    While fractal models can characterize self-similarity in binary fields, comprised solely of 0's and 1's, the concept of multifractals is needed to quantify scaling behavior in non-binary grayscale fields made up of fractional values. Multifractals are characterized by a spectrum of non-integer dimensions, Dq (-∞ lacunarity, L, which characterizes the distribution of gaps or spaces in patterns, fractals, multifractals or otherwise, as a function of scale (or box-size, x). In the case of 2-dimensional multifractal fields, L has been shown to be theoretically related to the correlation dimension, D2, by dlog(L)/dlog(x) = D2 - 2. Therefore, it is hypothesized that lacunarity analysis can help in delineating multifractal behavior in grayscale patterns. In testing this hypothesis, a set of 2-dimensional multifractal grayscale patterns was generated with known D2 values, and then analyzed for lacunarity by employing the gliding-box algorithm. The D2 values computed using this analysis gave a 1:1 relationship with the known D2 values, thus empirically validating the theoretical relationship between L and D2. Lacunarity analysis was further used to evaluate the multifractal nature of natural grayscale images in the form of soil thin sections that had been previously classified as multifractals based on the standard box counting method. The results indicated that lacunarity analysis is a more sensitive indicator of multifractal behavior in natural grayscale patterns than the box counting approach. A weighted mean of the log-transformed lacunarity values at different scales was employed for differentiating between grayscale patterns with various degrees of scale dependent clustering attributes. This new measure, which expresses lacunarity as a single number, should prove useful to researchers who want to explore the correlative influence of texture on, for instance, flow and transport parameters. The advantage of using lacunarity instead of D2 in this context is that it can

  9. Lacunarity Measures of Potential Fields in Covered Lithology Identification

    Science.gov (United States)

    Gettings, M. E.

    2013-12-01

    Measure distributions, both multifractal and other kinds, are not unique, so spatial patterns with the same measure may have different appearances. Lacunarity analysis is a method of description of dispersion in spatial patterns across a range of scales, and is one way of descriminating clustering of similar values. Lacunarity of an image was calculated using a moving window across a range of scales as the ratio of the second moment divided by the square of the first moment for values within the window. This gives a curve of lacunarity versus resolution (scale); the curve is concave for highly clustered data, pseudolinear or convex for data with clusters at many scales such as multifractal simulations, and constant for uniformly spaced data. Breaks in slope of the curve indicate scales that are important in the structure of the spatial pattern. Gravity and magnetic field anomaly data are well known to be multifractal and thus calculated lacunarities of gridded datasets have been investigated to determine if the resulting curves are a useful measure of texture of the potential field data and helpful in identifying likely lithologies at depth beneath cover. Lacunarity is often calculated on binary data, but it can also be calculated using quantitative data. The quantitative data case lacunarity measure was computed for grids using a 25 by 25 km window moving over the grid, each window overlapping the previous one by 12.5 km. The data were the aeromagnetic and isostatic gravity anomaly grids for the state of Arizona at 0.5 km grid-interval, resulting in a lacunarity curves for gravity and aeromagnetic anomaly for each of approximately 2500 windows. The open-source software R was used for plotting a map of window center locations and lacunarity curves, and the map was loaded into Google Earth, together with maps of the gravity and magnetic field anomaly, porphyry copper deposit locations, and the geological map of Arizona. Windows were selected to compare lacunarity

  10. Efficacy of antiplatelet therapy in secondary prevention following lacunar stroke: pooled analysis of randomized trials.

    Science.gov (United States)

    Kwok, Chun Shing; Shoamanesh, Ashkan; Copley, Hannah Charlotte; Myint, Phyo Kyaw; Loke, Yoon K; Benavente, Oscar R

    2015-04-01

    Lacunar stroke accounts for ≈25% of ischemic stroke, but optimal antiplatelet regimen to prevent stroke recurrence remains unclear. We aimed to evaluate the efficacy of antiplatelet agents in secondary stroke prevention after a lacunar stroke. We searched MEDLINE, Embase, and the Cochrane library for randomized controlled trials that reported risk of recurrent stroke or death with antiplatelet therapy in patients with lacunar stroke. We used random effects meta-analysis and evaluated heterogeneity with I(2). We included 17 trials with 42,234 participants (mean age 64.4 years, 65% male) and follow up ranging from 4 weeks to 3.5 years. Compared with placebo, any single antiplatelet agent was associated with a significant reduction in recurrence of any stroke (risk ratio [RR] 0.77, 0.62-0.97, 2 studies) and ischemic stroke (RR 0.48, 0.30-0.78, 2 studies), but not for the composite outcome of any stroke, myocardial infarction, or death (RR 0.89, 0.75-1.05, 2 studies). When other antiplatelet agents (ticlodipine, cilostazol, and dipyridamole) were compared with aspirin, there was no consistent reduction in stroke recurrence (RR 0.91, 0.75-1.10, 3 studies). Dual antiplatelet therapy did not confer clear benefit over monotherapy (any stroke RR 0.83, 0.68-1.00, 3 studies; ischemic stroke RR 0.80, 0.62-1.02, 3 studies; composite outcome RR 0.90, 0.80-1.02, 3 studies). Our results suggest that any of the single antiplatelet agents compared with placebo in the included trials is adequate for secondary stroke prevention after lacunar stroke. Dual antiplatelet therapy should not be used for long-term stroke prevention in this stroke subtype. © 2015 American Heart Association, Inc.

  11. MRI findings in patients with multiple lacunar infarcts manifesting hyperactive-type delirium

    Energy Technology Data Exchange (ETDEWEB)

    Arahata, Yutaka; Motegi, Yoshimasa; Furuse, Masahiro (Nakatsugawa Municipal General Hospital, Gifu (Japan)); Watanabe, Masaki; Takahashi, Akira

    1994-04-01

    MRI studies were carried out on 69 patients with multiple lacunar infarcts: 32 had hyperactive-type delirium and the other 37 were non-delirious controls. Between the two groups, there were no statistically significant differences in mean age and sex distribution. In the corona radiata and basal ganglia, the number of infarcts did not differ between the two groups. However, the extent of thalamic infarcts and periventricular hyperintensity (PVH), the maximal width of the third ventricle and Evans' ratio among the delirious patients were significantly larger than those in the controls. In conclusion, thalamic lesions and diffuse advanced PVH may have an intimate correlation in the development of hyperactive-type delirium in patients with multiple lacunar infarcts. (author).

  12. Biomaterial porosity determined by fractal dimensions, succolarity and lacunarity on microcomputed tomographic images

    Energy Technology Data Exchange (ETDEWEB)

    N' Diaye, Mambaye [LUNAM Université, GEROM Groupe Etudes Remodelage Osseux et bioMatériaux-LHEA, IRIS-IBS Institut de Biologie en Santé, CHU d' Angers, 49933 ANGERS Cedex (France); Degeratu, Cristinel [LUNAM Université, GEROM Groupe Etudes Remodelage Osseux et bioMatériaux-LHEA, IRIS-IBS Institut de Biologie en Santé, CHU d' Angers, 49933 ANGERS Cedex (France); University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Department of Bioresources and Polymer Science, Calea Victoriei 149, 010072, Sector 1, Bucharest (Romania); Bouler, Jean-Michel [Inserm UMR 791, LIOAD, University of Nantes, 44000 Nantes (France); Chappard, Daniel, E-mail: daniel.chappard@univ-angers.fr [LUNAM Université, GEROM Groupe Etudes Remodelage Osseux et bioMatériaux-LHEA, IRIS-IBS Institut de Biologie en Santé, CHU d' Angers, 49933 ANGERS Cedex (France)

    2013-05-01

    Porous structures are becoming more and more important in biology and material science because they help in reducing the density of the grafted material. For biomaterials, porosity also increases the accessibility of cells and vessels inside the grafted area. However, descriptors of porosity are scanty. We have used a series of biomaterials with different types of porosity (created by various porogens: fibers, beads …). Blocks were studied by microcomputed tomography for the measurement of 3D porosity. 2D sections were re-sliced to analyze the microarchitecture of the pores and were transferred to image analysis programs: star volumes, interconnectivity index, Minkowski–Bouligand and Kolmogorov fractal dimensions were determined. Lacunarity and succolarity, two recently described fractal dimensions, were also computed. These parameters provided a precise description of porosity and pores' characteristics. Non-linear relationships were found between several descriptors e.g. succolarity and star volume of the material. A linear correlation was found between lacunarity and succolarity. These techniques appear suitable in the study of biomaterials usable as bone substitutes. Highlights: ► Interconnected porosity is important in the development of bone substitutes. ► Porosity was evaluated by 2D and 3D morphometry on microCT images. ► Euclidean and fractal descriptors measure interconnectivity on 2D microCT images. ► Lacunarity and succolarity were evaluated on a series of porous biomaterials.

  13. 维生素B12与腔隙性梗死后抑郁的相关性分析%Study on the association of Vitamin B12 and depression secondary to lacunar cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    唐劭年; 任兰振; 胡宗继; 刘立雄

    2014-01-01

    目的:对维生素B12与腔隙性梗死后抑郁存在的相关性进行探讨。方法将我院2011-01-2013-01收治的腔隙性梗死患者798例分为对照组708例与观察组90例,对照组无抑郁症,观察组存在抑郁症(根据汉密尔顿抑郁量表判定),对比并分析2组患者的维生素B12水平。结果对照组血清维生素B12平均浓度为(178.6±20.7)pmol/L ,维生素B12缺乏197例(27.9%),观察组,血清维生素 B12平均浓度(141.7±19.7)pmol/L ,维生素 B12缺乏60例(66.7%),2组比较差异均有统计学意义( P<0.05)。结论维生素B12缺乏与腔隙性梗死后抑郁存在着相关性,腔隙性梗死并抑郁患者的维生素B12水平较普通腔隙性梗死患者更低,维生素B12缺乏情况较为明显,在治疗过程中适当补充维生素B12可以让患者的抑郁症状得到缓解,并可提升腔隙性梗死的治疗效果,促进患者恢复。%Objective To investigate the relevance between vitamin B12 and depression after lacunar cerebral infarc-tion.Methods Seventy hundred and ninety-eight patients with lacunar cerebral infarction admitted to our hospital from January 2011 to January 2011 were divided into control group(708 cases) and observation group (90 cases) ,no depression in control group patients ,the observation group patients had depression (judged according to the Hamilton depression rating scale ) ,vita-min B12 levels of patients in the two groups were analyzed and compared.Results The mean concentration of serum vitamin B12 of the control group was(178.6 ± 20.7)pmol/L ,the number of patients with vitamin B12 deficiency was 197 ,the ratio of which was 27.9% ;In the observation group ,the mean concentration of serum vitamin B12 was(141.7 ± 19.7)pmol/L ,the number of patients with vitamin B12 deficiency was 60 ,the ratio of which was 66.7%.The difference between the two groups had statisti-cal significance (P<0.05). Conclusion There is

  14. Location of lacunar infarcts correlates with cognition in a sample of non-disabled subjects with age-related white-matter changes: the LADIS study

    DEFF Research Database (Denmark)

    Benisty, S; Gouw, A A; Porcher, R

    2009-01-01

    OBJECTIVES: In cerebral small vessel disease, white-matter hyperintensities (WMH) and lacunes are both related to cognition. Still, their respective contribution in older people remains unclear. The purpose of this study is to assess the topographic distribution of lacunes and determine whether i...... and caudate nucleus. CONCLUSION: In non-disabled elderly subjects with leucoaraisosis, the location of lacunes within subcortical grey matter is a determinant of cognitive impairment, independently of the extent of WMH.......OBJECTIVES: In cerebral small vessel disease, white-matter hyperintensities (WMH) and lacunes are both related to cognition. Still, their respective contribution in older people remains unclear. The purpose of this study is to assess the topographic distribution of lacunes and determine whether...... it has an impact on cognitive functions in a sample of non-disabled patients with age-related white-matter changes. METHODS: Data were drawn from the baseline evaluation of the LADIS (Leucoaraioisis and Disability study) cohort of non-disabled subjects beyond 65 years of age. The neuropsychological...

  15. Effects of specific surface area and porosity on cube counting fractal dimension, lacunarity, configurational entropy, and permeability of model porous networks: Random packing simulations and NMR micro-imaging study

    Science.gov (United States)

    Lee, Bum Han; Lee, Sung Keun

    2013-07-01

    Despite the importance of understanding and quantifying the microstructure of porous networks in diverse geologic settings, the effects of the specific surface area and porosity on the key structural parameters of the networks have not been fully understood. We performed cube-counting fractal dimension (Dcc) and lacunarity analyses of 3D porous networks of model sands and configurational entropy analysis of 2D cross sections of model sands using random packing simulations and nuclear magnetic resonance (NMR) micro-imaging. We established relationships among porosity, specific surface area, structural parameters (Dcc and lacunarity), and the corresponding macroscopic properties (configurational entropy and permeability). The Dcc of the 3D porous networks increases with increasing specific surface area at a constant porosity and with increasing porosity at a constant specific surface area. Predictive relationships correlating Dcc, specific surface area, and porosity were also obtained. The lacunarity at the minimum box size decreases with increasing porosity, and that at the intermediate box size (∼0.469 mm in the current model sands) was reproduced well with specific surface area. The maximum configurational entropy increases with increasing porosity, and the entropy length of the pores decreases with increasing specific surface area and was used to calculate the average connectivity among the pores. The correlation among porosity, specific surface area, and permeability is consistent with the prediction from the Kozeny-Carman equation. From the relationship between the permeability and the Dcc of pores, the permeability can be expressed as a function of the Dcc of pores and porosity. The current methods and these newly identified correlations among structural parameters and properties provide improved insights into the nature of porous media and have useful geophysical and hydrological implications for elasticity and shear viscosity of complex composites of rock

  16. Changes in fractal dimension and lacunarity as early markers of UV-induced apoptosis.

    Science.gov (United States)

    Pantic, Igor; Harhaji-Trajkovic, Ljubica; Pantovic, Aleksandar; Milosevic, Nebojsa T; Trajkovic, Vladimir

    2012-06-21

    The aim of our study was to employ fractal analysis for evaluation of ultrastructural changes during early stages of apoptosis. Apoptosis was induced in U251 human glioma cell line by exposure to UVB light. The cells were visualized by optical phase-contrast microscopy and photographed before the UV treatment, immediately after the treatment, as well as at 30 min intervals during 5h observation period. For each of the 32 cells analyzed, cellular and nuclear fractal dimension, as well as nuclear lacunarity, were determined at each time point. Our data demonstrate that cellular ultrastructural complexity determined by fractal dimension and lacunarity significantly decreases after the UV irradiation, with the nuclear lacunarity being a particularly sensitive parameter in detecting early apoptosis. Importantly, fractal analysis was able to detect cellular apoptotic changes earlier than conventional flow cytometric analysis of phosphatidylserine exposure, DNA fragmentation and cell membrane permeabilization. These results indicate that fractal analysis might be a powerful and affordable method for non-invasive early identification of apoptosis in cell cultures. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Lacunarity analysis of fracture networks: Evidence for scale-dependent clustering

    Science.gov (United States)

    Roy, Ankur; Perfect, Edmund; Dunne, William M.; Odling, Noelle; Kim, Jung-Woo

    2010-10-01

    Previous studies on fracture networks have shown that fractures contained within distinct mechanical units ("stratabound") are regularly spaced while those that terminate within the rock mass are clustered ("non-stratabound"). Lacunarity is a parameter which can quantify the distribution of spaces between rock fractures. When normalized to account for differences in fracture abundance, lacunarity characterizes the distribution of spaces as the degree of clustering in the fracture network. Normalized lacunarity curves, L∗( r), computed using the gliding-box algorithm and plotted as a function of box-size, r, were constructed for natural fracture patterns from Telpyn Point, Wales and the Hornelen basin, Norway. The results from analysis of the Telpyn Point fractures indicate that such curves are sensitive to differences in the clustering of different fracture sets at the same scale. For fracture networks mapped at different scales from the Hornelen basin, our analysis shows that clustering increases with decreasing spatial scale. This trend is attributed to the transition from a "stratabound" system at the scale of sedimentary cycles (100-200 m) that act as distinct mechanical units to a "non-stratabound" fracture system geometry at the finer 10's of meters thick bedding scale.

  18. Preliminary analysis of osteocyte lacunar density in long bones of tetrapods: all measures are bigger in sauropod dinosaurs.

    Science.gov (United States)

    Stein, Koen W H; Werner, Jan

    2013-01-01

    Osteocytes harbour much potential for paleobiological studies. Synchrotron radiation and spectroscopic analyses are providing fascinating data on osteocyte density, size and orientation in fossil taxa. However, such studies may be costly and time consuming. Here we describe an uncomplicated and inexpensive method to measure osteocyte lacunar densities in bone thin sections. We report on cell lacunar densities in the long bones of various extant and extinct tetrapods, with a focus on sauropodomorph dinosaurs, and how lacunar densities can help us understand bone formation rates in the iconic sauropod dinosaurs. Ordinary least square and phylogenetic generalized least square regressions suggest that sauropodomorphs have lacunar densities higher than scaled up or comparably sized mammals. We also found normal mammalian-like osteocyte densities for the extinct bovid Myotragus, questioning its crocodilian-like physiology. When accounting for body mass effects and phylogeny, growth rates are a main factor determining the density of the lacunocanalicular network. However, functional aspects most likely play an important role as well. Observed differences in cell strategies between mammals and dinosaurs likely illustrate the convergent nature of fast growing bone tissues in these groups.

  19. Preliminary analysis of osteocyte lacunar density in long bones of tetrapods: all measures are bigger in sauropod dinosaurs.

    Directory of Open Access Journals (Sweden)

    Koen W H Stein

    Full Text Available Osteocytes harbour much potential for paleobiological studies. Synchrotron radiation and spectroscopic analyses are providing fascinating data on osteocyte density, size and orientation in fossil taxa. However, such studies may be costly and time consuming. Here we describe an uncomplicated and inexpensive method to measure osteocyte lacunar densities in bone thin sections. We report on cell lacunar densities in the long bones of various extant and extinct tetrapods, with a focus on sauropodomorph dinosaurs, and how lacunar densities can help us understand bone formation rates in the iconic sauropod dinosaurs. Ordinary least square and phylogenetic generalized least square regressions suggest that sauropodomorphs have lacunar densities higher than scaled up or comparably sized mammals. We also found normal mammalian-like osteocyte densities for the extinct bovid Myotragus, questioning its crocodilian-like physiology. When accounting for body mass effects and phylogeny, growth rates are a main factor determining the density of the lacunocanalicular network. However, functional aspects most likely play an important role as well. Observed differences in cell strategies between mammals and dinosaurs likely illustrate the convergent nature of fast growing bone tissues in these groups.

  20. Lacunarity Analyses of Multifractal and Natural Grayscale Patterns

    Science.gov (United States)

    Roy, Ankur; Perfect, Edmund

    2014-09-01

    Lacunarity (L) is a scale (r)-dependent parameter that was developed for quantifying clustering in fractals and has subsequently been employed to characterize various natural patterns. For multifractals it can be shown analytically that L is related to the correlation dimension, D2, by: dlog(L)/dlog(r) = D2 - 2. We empirically tested this equation using two-dimensional multifractal grayscale patterns with known correlation dimensions. These patterns were analyzed for their lacunarity using the gliding-box algorithm. D2 values computed from the dlog(L)/dlog(r) analysis gave a 1:1 relationship with the known D2 values. Lacunarity analysis was also employed in discriminating between multifractal grayscale patterns with the same D2 values, but different degrees of scale-dependent clustering. For this purpose, a new lacunarity parameter, , was formulated based on the weighted mean of the log-transformed lacunarity values at different scales. This approach was further used to evaluate scale-dependent clustering in soil thin section grayscale images that had previously been classified as multifractals based on standard method of moments box-counting. Our results indicate that lacunarity analysis may be a more sensitive indicator of multifractal behavior in natural grayscale patterns than the standard approach. Thus, multifractal behavior can be checked without having to compute the whole spectrum of non-integer dimensions, Dq(-∞ parameter should be useful to researchers who want to explore the correlative influence of clustering on flow and transport in grayscale representations of soil aggregates and heterogeneous aquifers.

  1. Relationship between necrotic patterns in glioblastoma and patient survival: fractal dimension and lacunarity analyses using magnetic resonance imaging.

    Science.gov (United States)

    Liu, Shuai; Wang, Yinyan; Xu, Kaibin; Wang, Zheng; Fan, Xing; Zhang, Chuanbao; Li, Shaowu; Qiu, Xiaoguang; Jiang, Tao

    2017-08-16

    Necrosis is a hallmark feature of glioblastoma (GBM). This study investigated the prognostic role of necrotic patterns in GBM using fractal dimension (FD) and lacunarity analyses of magnetic resonance imaging (MRI) data and evaluated the role of lacunarity in the biological processes leading to necrosis. We retrospectively reviewed clinical and MRI data of 95 patients with GBM. FD and lacunarity of the necrosis on MRI were calculated by fractal analysis and subjected to survival analysis. We also performed gene ontology analysis in 32 patients with available RNA-seq data. Univariate analysis revealed that FD lacunarity > 0.46 significantly correlated with poor progression-free survival (p = 0.006 and p = 0.012, respectively) and overall survival (p = 0.008 and p = 0.005, respectively). Multivariate analysis revealed that both parameters were independent factors for unfavorable progression-free survival (p = 0.001 and p = 0.015, respectively) and overall survival (p = 0.002 and p = 0.007, respectively). Gene ontology analysis revealed that genes positively correlated with lacunarity were involved in the suppression of apoptosis and necrosis-associated biological processes. We demonstrate that the fractal parameters of necrosis in GBM can predict patient survival and are associated with the biological processes of tumor necrosis.

  2. The usefulness of fractional anisotropy maps in localization of lacunar infractions in striatum, internal capsule and thalamus

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, H.K.; Lee, S.K.; Kim, D.I. [Dept. of Radiology and Research, Yonsei University Coll. of Medicine, Seoul (Korea); JHeo, J.H. [Dept. of Neurology, Yonsei University Coll. of Medicine, Seoul (Korea)

    2005-04-01

    We aimed in this study to assess the clinical usefulness of fractional anisotropy (FA) maps in the evaluation of lacunar infractions in striatum, internal capsule and thalamus. We retrospectively reviewed 28 patients (18 mean, 10 women; mean age 63 years) who had acute lacunar infraction in striatum, internal capsule and thalamus on diffusion weighted MR imaging (DWI). Fractional anisotropy (FA) maps were generated in addition to conventional T2 weigthed images (T2WI) and trace masp of DWI. Two radiologists reviewed the location of infraction was determined by FA maps. i.e. on the white band of internal capsule. Accuracy and inter-observer agreement on determination of the location of interfraction was evaluated. Accuracy of infract localization by T2WI-DWI only was varied from 72 to 91% according to the observers. Inter-observer agreement value was moderate (Kappa=0.446), when images were interpreted by T2WI-DWI only. Clinical manifestation of each lesions wre varied, but sensory motor stroke was mainly observed in thalamic lesion (50%) while pure motor hemiparesis was predominant in the case of infract involving internal capsule, corona radiata (91%) and basal ganglia (83%). The FA maps is useful in the evaluation of lacunar lesions in striatum, internal capsule and thalamus. Clinical presentation varies according to the exact location of lacunar infractions, and more accurate diagnosis can be made by FA maps as well as conventional T2-weighted image and DWI.

  3. Towards biologically relevant indicators of forest structure using lacunarity approach based on voxelized LiDAR data

    Science.gov (United States)

    Székely, Balázs; Kania, Adam; Standovár, Tibor; Heilmeier, Hermann

    2014-05-01

    Considering the forest as a porous material that consists of the trees and other vegetation (representing the grains or aggregated grain groups) and the empty space between the plants (as the porous space in the analogy) this geometrical model provides a new approach to study the structure of the vegetation. Lacunarity, defined by Mandelbrot (1982), is a straightforward measure of structured empty space divided by the vegetation. This approach may allow the application of various concepts developed for porous media like tortuosity, percolation, directed percolation, anisotropic behaviour etc. The original LiDAR point cloud is voxelized using a voxel size determined by the point density. Our approach considers 2D and 3D lacunarities derived from the voxels; in 2D approach the topography-parallel and topography-perpendicular cross-sections are considered. In the latter case anisotropic behaviour can also be analysed. The lacunarity curves are evaluated in order to quantify the structural diversity that is positively related to species diversity. The relationship of vertical profile structural diversity to the richness of bird community has been widely shown in a wide range of forest types. The proposed method is able to characterize the structural differences that later can be related to the recognized relationships. Lacunarity curves can be further analysed to focus on both fine-scale (Mandelbrot, B. (1982): The fractal geometry of nature. Freeman, San Francisco.

  4. Angular structure of lacunarity, and the renormalization group

    Science.gov (United States)

    Ball; Caldarelli; Flammini

    2000-12-11

    We formulate the angular structure of lacunarity in fractals, in terms of a symmetry reduction of the three point correlation function. This provides a rich probe of universality, and first measurements yield new evidence in support of the equivalence between self-avoiding walks (SAW's) and percolation perimeters in two dimensions. We argue that the lacunarity reveals much of the renormalization group in real space. This is supported by exact calculations for random walks and measured data for percolation clusters and SAW's. Relationships follow between exponents governing inward and outward propagating perturbations, and we also find a very general test for the contribution of long-range interactions.

  5. Parameterized approximation of lacunarity functions derived from airborne laser scanning point clouds of forested areas

    Science.gov (United States)

    Székely, Balázs; Kania, Adam; Varga, Katalin; Heilmeier, Hermann

    2017-04-01

    Lacunarity, a measure of the spatial distribution of the empty space is found to be a useful descriptive quantity of the forest structure. Its calculation, based on laser-scanned point clouds, results in a four-dimensional data set. The evaluation of results needs sophisticated tools and visualization techniques. To simplify the evaluation, it is straightforward to use approximation functions fitted to the results. The lacunarity function L(r), being a measure of scale-independent structural properties, has a power-law character. Previous studies showed that log(log(L(r))) transformation is suitable for analysis of spatial patterns. Accordingly, transformed lacunarity functions can be approximated by appropriate functions either in the original or in the transformed domain. As input data we have used a number of laser-scanned point clouds of various forests. The lacunarity distribution has been calculated along a regular horizontal grid at various (relative) elevations. The lacunarity data cube then has been logarithm-transformed and the resulting values became the input of parameter estimation at each point (point of interest, POI). This way at each POI a parameter set is generated that is suitable for spatial analysis. The expectation is that the horizontal variation and vertical layering of the vegetation can be characterized by this procedure. The results show that the transformed L(r) functions can be typically approximated by exponentials individually, and the residual values remain low in most cases. However, (1) in most cases the residuals may vary considerably, and (2) neighbouring POIs often give rather differing estimates both in horizontal and in vertical directions, of them the vertical variation seems to be more characteristic. In the vertical sense, the distribution of estimates shows abrupt changes at places, presumably related to the vertical structure of the forest. In low relief areas horizontal similarity is more typical, in higher relief areas

  6. Hemodynamic factors may play a critical role in neurological deterioration occurring within 72 hrs after lacunar stroke.

    Directory of Open Access Journals (Sweden)

    Yen-Chu Huang

    Full Text Available BACKGROUND: Whether a perfusion defect exists in lacunar infarct and whether it is related to early neurological deterioration (END is still under debate. The aim of this study was to evaluate whether END in lacunar infarct is related to a perfusion defect using diffusion-weighted imaging (DWI, diffusion tensor imaging (DTI and perfusion MR imaging. METHODS: One hundred and forty-one consecutive patients had an MRI scan within 30 hours after onset of symptoms and 43 patients with acute lacunar infarct and classic lacunar syndrome were recruited. The MRI sequences included DWI, DTI and cerebral blood flow (CBF maps to respectively represent the topographic locations of acute infarcts, the corticospinal tract and perfusion defects. The END was defined in reference to the National Institute of Health Stroke Scale (NIHSS as an increase ≧2 within 72 hours. Cohen's Kappa coefficient was used to examine the reliability between the 2 image readers. A multivariate logistic regression model was constructed adjusting for baseline variables. RESULTS: Ten out of the 43 patients had END. Patients having END was significantly associated with lower chances of favorable and good outcomes at 3 months (p = 0.01 and p = 0.002, respectively. END was predicted when the non-core hypoperfused area overlapped on the corticospinal tract, which is defined as the expected END profile. Cohen's Kappa coefficient between the 2 image readers to define images of expected END profiles was 0.74. In 15 patients with expected END profile, 9 had END clinically, whereas 28 patients had no expected END profile, and only 1 patient had END (p<0.0001. After adjusting for sex, the expected END profile was still associated with END (odds ratio, 42.2; p = 0.002. CONCLUSION: Our study demonstrated that the END in acute lacunar stroke is likely related to the transformation of non-core hypoperfused area into infarction in the anatomy of corticospinal tracts.

  7. 17q25 Locus is associated with white matter hyperintensity volume in ischemic stroke, but not with lacunar stroke status.

    Science.gov (United States)

    Adib-Samii, Poneh; Rost, Natalia; Traylor, Matthew; Devan, William; Biffi, Alessandro; Lanfranconi, Silvia; Fitzpatrick, Kaitlin; Bevan, Steve; Kanakis, Allison; Valant, Valerie; Gschwendtner, Andreas; Malik, Rainer; Richie, Alexa; Gamble, Dale; Segal, Helen; Parati, Eugenio A; Ciusani, Emilio; Holliday, Elizabeth G; Maguire, Jane; Wardlaw, Joanna; Worrall, Bradford; Bis, Joshua; Wiggins, Kerri L; Longstreth, Will; Kittner, Steve J; Cheng, Yu-Ching; Mosley, Thomas; Falcone, Guido J; Furie, Karen L; Leiva-Salinas, Carlos; Lau, Benison C; Saleem Khan, Muhammed; Sharma, Pankaj; Fornage, Myriam; Mitchell, Braxton D; Psaty, Bruce M; Sudlow, Cathie; Levi, Christopher; Boncoraglio, Giorgio B; Rothwell, Peter M; Meschia, James; Dichgans, Martin; Rosand, Jonathan; Markus, Hugh S

    2013-06-01

    Recently, a novel locus at 17q25 was associated with white matter hyperintensities (WMH) on MRI in stroke-free individuals. We aimed to replicate the association with WMH volume (WMHV) in patients with ischemic stroke. If the association acts by promoting a small vessel arteriopathy, it might be expected to also associate with lacunar stroke. We quantified WMH on MRI in the stroke-free hemisphere of 2588 ischemic stroke cases. Association between WMHV and 6 single-nucleotide polymorphisms at chromosome 17q25 was assessed by linear regression. These single-nucleotide polymorphisms were also investigated for association with lacunar stroke in 1854 cases and 51 939 stroke-free controls from METASTROKE. Meta-analyses with previous reports and a genetic risk score approach were applied to identify other novel WMHV risk variants and uncover shared genetic contributions to WMHV in community participants without stroke and ischemic stroke. Single-nucleotide polymorphisms at 17q25 were associated with WMHV in ischemic stroke, the most significant being rs9894383 (P=0.0006). In contrast, there was no association between any single-nucleotide polymorphism and lacunar stroke. A genetic risk score analysis revealed further genetic components to WMHV shared between community participants without stroke and ischemic stroke. This study provides support for an association between the 17q25 locus and WMH. In contrast, it is not associated with lacunar stroke, suggesting that the association does not act by promoting small-vessel arteriopathy or the same arteriopathy responsible for lacunar infarction.

  8. 腔隙性脑梗死患者脑微出血与血清同型半胱氨酸的相关性研究%The Study of Cerebral Microbleeds and Homocysteine in Lacunar Infarction

    Institute of Scientific and Technical Information of China (English)

    张金; 郝冬琳; 何国平

    2014-01-01

    目的:分析腔隙性脑梗死患者脑微出血(CMB)与血清同型半胱氨酸(Hcy)的关系。方法选择急性腔隙性脑梗死患者85例,行MR SWI序列检查,根据CMB的数量,分为轻度(1个CMB)、中度(4个CMB)、重度CMB(10个以上CMB)组。记录患者临床特点,检测患者血清Hcy水平,分析Hcy与CMB的关系。结果85例急性腔隙性脑梗死患者中,有CMB 35例(41.2%),其中轻度CMB组5例、中度CMB组10例、重度CMB组20例。血清同型半胱氨酸:CMB轻度组(14.2±3.1)μmol·L-1,中度组(17.5±2.6)μmol·L-1,重度组(19.0±3.8)μmol·L-1,方差分析发现,组间比较差异有统计学意义(F=4.579,P=0.019);CMB重度组血清Hcy水平高于轻度及中度组(P<0.05);Spearm相关分析发现CMB病变程度与血清Hcy水平呈正相关(r=0.768,P<0.001)。结论血清Hcy与腔隙性脑梗死患者的CMB有关,Hcy是CMB可能的危险因素;Hcy可以作为脑小血管病损伤的标志物之一,对CMB诊断和治疗有重要意义。%Aim To investigate the associations between the presence of cerebral microbleeds (CMB) and homocysteine (Hcy) in lacunar infarction. Methods Eighty five lacunar infarction patients were enrolled. All patients received cranial magnetic resonance imaging included susceptibility-weighted imaging at the ifrst week. The serum levels of Hcy were detected in patients. Results Among a total of 85 patients, 35(41.2%) patients were detected with CMB. The Hcy levels were (14.2±3.1) μmol·L-1 in mild CMB group, (17.5±2.6)μmol·L-1 in moderate CMB group, (19.0±3.8)μmol·L-1 in severe CMB group, and there were signiifcant differences by analysis of variance (F=4.579,P=0.019). The Hcy levels in severe CMB group were higher than that of mild and moderate CMB group (P<0.05). Spearm analysis indicated that the severity of CMB was positively related with Hcy levels (r=0.768, P<0.001). Conclusion CMB have a relatively high prevalence in lacunar infarction. Hcy is

  9. Lacunarity of geophysical well logs in the Cantarell oil field, Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Arizabalo, Ruben Dario [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Oleschko, Klavdia [Centro de Geociencias, Universidad Nacional Autonoma de Mexico, Juriquilla, Queretaro (Mexico); Korvin, Gabor [King Fahd University, Dhahran (Saudi Arabia); Lozada, Manuel [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Castrejon, Ricardo [Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico); Ronquillo, Gerardo [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico)

    2006-04-15

    Lacunarity and fractal variations in geophysical well logs are associated with stratigraphic and petrophysical properties of the naturally fractured Cantarell field in the Gulf of Mexico. Neutron porosity (NPHI), density (RHOB, DRHO, PEF), resistivity (LLD, LLS, MSFL), natural radioactivity (GR, CGR, URAN, POTA, THOR) and caliper (CALI) logs are studied. The resistivity logs yielded remarkably high lacunarity values, especially in the hydrocarbon source- and reservoir rocks. Lacunarity {delta} was found to depend on the resolution and radial depth of penetration of the logging method. It systematically increased in the following order: {delta}(RHOB) < {delta}(CALI) < {delta}(PEF) < {delta}(URAN) < {delta}(GR) < {delta}(NPHI) < {delta}(POTA) < {delta}(CGR) < {delta}(THOR) < {delta}(MSFL) < {delta}(DRHO) < {delta}(LLS) < {delta}(LLD). [Spanish] En este trabajo fueron analizadas las variaciones fractales y de lagunaridad de los registros geofisicos de pozo, con el fin de asociarlos con las propiedades estratigraficas y petrofisicas del yacimiento naturalmente fracturado de Cantarell, en el Golfo de Mexico. Los registros considerados fueron: porosidad neutron (NPHI), densidad (RHOB, DRHO, PEF), resistividad (LLD, LLS, MSFL), radiactividad natural (GR, CGR, URAN, POTA, THOR) y caliper (CALI). Los registros de resistividad produjeron valores de lagunaridad notablemente altos, especialmente en las rocas generadoras y almacenadoras, a diferencia de los demas registros, cuya homogeneidad de traza implico una baja lagunaridad. Los resultados indican que la lagunaridad observada depende de la resolucion y profundidad radial de penetracion del metodo geofisico estudiado y aumenta sistematicamente en el siguiente orden: {delta}(RHOB) < {delta}(CALI) < {delta}(PEF) < {delta}(URAN) < {delta}(GR) < {delta}(NPHI) < {delta}(POTA) < {delta}(CGR) < {delta}(THOR) < {delta}(MSFL) < {delta}(DRHO) < {delta}(LLS) < {delta}(LLD).

  10. Lacunarity Elimination in the Translation of Nonequivalent Juridical Terms

    Directory of Open Access Journals (Sweden)

    Vladimir A. Lazarev

    2017-06-01

    Full Text Available In the article the authors refer to the problem of lacunarity elimination in legal texts reflecting national specific features in the legal sphere. Various ways of filling gaps when translating from English into Russian are suggested using legal-dogmatic theoretical texts as an example. Different variants of the lacunae elimination are proposed, which take into account the peculiarities of this type of text and can assist in the work of a legal translator.

  11. Biomaterial porosity determined by fractal dimensions, succolarity and lacunarity on microcomputed tomographic images.

    Science.gov (United States)

    N'Diaye, Mambaye; Degeratu, Cristinel; Bouler, Jean-Michel; Chappard, Daniel

    2013-05-01

    Porous structures are becoming more and more important in biology and material science because they help in reducing the density of the grafted material. For biomaterials, porosity also increases the accessibility of cells and vessels inside the grafted area. However, descriptors of porosity are scanty. We have used a series of biomaterials with different types of porosity (created by various porogens: fibers, beads …). Blocks were studied by microcomputed tomography for the measurement of 3D porosity. 2D sections were re-sliced to analyze the microarchitecture of the pores and were transferred to image analysis programs: star volumes, interconnectivity index, Minkowski-Bouligand and Kolmogorov fractal dimensions were determined. Lacunarity and succolarity, two recently described fractal dimensions, were also computed. These parameters provided a precise description of porosity and pores' characteristics. Non-linear relationships were found between several descriptors e.g. succolarity and star volume of the material. A linear correlation was found between lacunarity and succolarity. These techniques appear suitable in the study of biomaterials usable as bone substitutes. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Parsimonious classification of binary lacunarity data computed from food surface images using kernel principal component analysis and artificial neural networks.

    Science.gov (United States)

    Iqbal, Abdullah; Valous, Nektarios A; Sun, Da-Wen; Allen, Paul

    2011-02-01

    Lacunarity is about quantifying the degree of spatial heterogeneity in the visual texture of imagery through the identification of the relationships between patterns and their spatial configurations in a two-dimensional setting. The computed lacunarity data can designate a mathematical index of spatial heterogeneity, therefore the corresponding feature vectors should possess the necessary inter-class statistical properties that would enable them to be used for pattern recognition purposes. The objectives of this study is to construct a supervised parsimonious classification model of binary lacunarity data-computed by Valous et al. (2009)-from pork ham slice surface images, with the aid of kernel principal component analysis (KPCA) and artificial neural networks (ANNs), using a portion of informative salient features. At first, the dimension of the initial space (510 features) was reduced by 90% in order to avoid any noise effects in the subsequent classification. Then, using KPCA, the first nineteen kernel principal components (99.04% of total variance) were extracted from the reduced feature space, and were used as input in the ANN. An adaptive feedforward multilayer perceptron (MLP) classifier was employed to obtain a suitable mapping from the input dataset. The correct classification percentages for the training, test and validation sets were 86.7%, 86.7%, and 85.0%, respectively. The results confirm that the classification performance was satisfactory. The binary lacunarity spatial metric captured relevant information that provided a good level of differentiation among pork ham slice images. Copyright © 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.

  13. Multifractal dimension and lacunarity of yolk sac vasculature after exposure to magnetic field.

    Science.gov (United States)

    Costa, Edbhergue Ventura Lola; Nogueira, Romildo de Albuquerque

    2015-05-01

    Several studies have reported about the effects of magnetic fields (MFs) on vascular tissue. Extremely low frequency magnetic fields (ELF-MFs) can promote either inhibition or stimulation of vasculogenesis and angiogenesis, depending upon the intensity and time of exposure to the MF. To investigate the possible effects of ELF-MF on vascular processes, it is necessary to employ methods that allow parameterization of the vascular network. Vascular network is a structure with fractal geometry; therefore, fractal methods have been used to evaluate its morphometric complexity. Here, we used the lacunarity parameter (complementary method of fractal analysis) and multifractal analyses to investigate angiogenesis and vasculogenesis in the embryonic yolk sac membrane (YSM) of Japanese quails (Coturnix japonica) with and without exposure to an external MF of 1 mT and 60 Hz. Lacunarity results showed that the vascular density was lower for the group exposed to the magnetic field for 9 h/day. In addition, multifractal analysis showed reduced vascularization in the experimental groups (6 h/day and 9 h/day of exposure to MF). Furthermore, multifractal analysis showed difference between the groups exposed for 12 and 24 h/day. Using multifractal methods (generalized dimensions and singularity spectrum), it was possible to characterize the vascular network of the quail embryo YSM as a multifractal object, therefore proving this method to be a more appropriate application than the traditional monofractal methods. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Moderate hyperglycaemia is associated with favourable outcome in acute lacunar stroke

    NARCIS (Netherlands)

    Uyttenboogaart, Maarten; Koch, Marcus W; Stewart, Roy E; Vroomen, Patrick C; Luijckx, Gert-Jan; De Keyser, Jacques

    Hyperglycaemia in acute ischaemic stroke is traditionally associated with a worsened outcome. However, it is unclear whether the impact of hyperglycaemia on stroke outcome is similar in lacunar and non-lacunar infarctions. The relation between serum glucose measured within 6 h after stroke onset and

  15. The cast imaging of the osteon lacunar-canalicular system and the implications with functional models of intracanalicular flow.

    Science.gov (United States)

    Pazzaglia, Ugo E; Congiu, Terenzio

    2013-02-01

    A casting technique with methyl-methacrylate (MMA) was applied to the study of the osteon lacunar-canalicular network of human and rabbit cortical bone. The MMA monomer infiltration inside the vascular canals and from these into the lacunar-canalicular system was driven by capillarity, helped by evaporation and the resulting negative pressure in a system of small pipes. There was uniform, centrifugal penetration of the resin inside some osteons, but this was limited to a depth of four to five layers of lacunae. Moreover, not all of the osteon population was infiltrated. This failure can be the result of one of two factors: the incomplete removal of organic debris from the canal and canalicular systems, and lack of drainage at the osteon external border. These data suggest that each secondary osteon is a closed system with a peripheral barrier (represented by the reversal line). As the resin advances into the osteon, the air contained inside the canalicula is compressed and its pressure increases until infiltration is stopped. The casts gave a reliable visualization of the lacunar shape, position and connections between the lacunae without the need for manipulations such as cutting or sawing. Two systems of canalicula could be distinguished, the equatorial, which connected the lacunae (therefore the osteocytes) lying on the same concentric level, and the radial, which established connections between different levels. The equatorial canalicula radiated from the lacunar border forming ramifications on a planar surface around the lacuna, whereas the radial canalicula had a predominantly straight direction perpendicular to the equatorial plane. The mean length of the radial canalicula was 40.12 ± 10.26 μm in rabbits and 38.4 ± 7.35 μm in human osteons; their mean diameter was 174.4 ± 71.12 nm and 195.7 ± 79.58 nm, respectively. The mean equatorial canalicula diameter was 237 ± 66.04 nm in rabbit and 249.7 ± 73.78 nm in human bones, both significantly larger (P

  16. Spatial distribution of lacunarity of voxelized airborne LiDAR point clouds in various forest assemblages

    Science.gov (United States)

    Székely, Balázs; Kania, Adam; Standovár, Tibor; Heilmeier, Hermann

    2015-04-01

    Forest ecosystems have characteristic structure of features defined by various structural elements of different scales and vertical positions: shrub layers, understory vegetation, tree trunks, and branches. Furthermore in most of the cases there are superimposed structures in distributions (mosaic or island patterns) due to topography, soil variability, or even anthropogenic factors like past/present forest management activity. This multifaceted spatial context of the forests is relevant for many ecological issues, especially for maintaining forest biodiversity. Our aim in this study is twofold: (1) to quantify this structural variability laterally and vertically using lacunarity, and (2) to relate these results to relevant ecological features, i.e quantitatively described forest properties. Airborne LiDAR data of various quality and point density have been used for our study including a number of forested sites in Central and East Europe (partly Natura 2000 sites). The point clouds have been converted to voxel format and then converted to horizontal layers as images. These images were processed further for the lacunarity calculation. Areas of interest (AOIs) have been selected based on evaluation of the forested areas and auxiliary field information. The calculation has been performed for the AOIs for all available vertical data slices. The lacunarity function referring to a certain point and given vicinity varies horizontally and vertically, depending on the vegetation structure. Furthermore, the topography may also influence this property as the growth of plants, especially spacing and size of trees are influenced by the local topography and relief (e.g., slope, aspect). The comparisons of the flatland and hilly settings show interesting differences and the spatial patterns also vary differently. Because of the large amount of data resulting from these calculations, sophisticated methods are required to analyse the results. The large data amount then has been

  17. MR imaging and osteoporosis: fractal lacunarity analysis of trabecular bone.

    Science.gov (United States)

    Zaia, Annamaria; Eleonori, Roberta; Maponi, Pierluigi; Rossi, Roberto; Murri, Roberto

    2006-07-01

    We develop a method of magnetic resonance (MR) image analysis able to provide parameter(s) sensitive to bone microarchitecture changes in aging, and to osteoporosis onset and progression. The method has been built taking into account fractal properties of many anatomic and physiologic structures. Fractal lacunarity analysis has been used to determine relevant parameter(s) to differentiate among three types of trabecular bone structure (healthy young, healthy perimenopausal, and osteoporotic patients) from lumbar vertebra MR images. In particular, we propose to approximate the lacunarity function by a hyperbola model function that depends on three coefficients, alpha, beta, and gamma, and to compute these coefficients as the solution of a least squares problem. This triplet of coefficients provides a model function that better represents the variation of mass density of pixels in the image considered. Clinical application of this preliminary version of our method suggests that one of the three coefficients, beta, may represent a standard for the evaluation of trabecular bone architecture and a potentially useful parametric index for the early diagnosis of osteoporosis.

  18. Organ and tissue level properties are more sensitive to age than osteocyte lacunar characteristics in rat cortical bone

    DEFF Research Database (Denmark)

    Wittig, Nina; Bach-Gansmo, Fiona Linnea; Birkbak, Mie Elholm

    2016-01-01

    lacunar properties in rat cortical bone. Femora of 14 to 42-week-old female Wistar rats were investigated using multiple complementary techniques including X-ray micro-computed tomography and biomechanical testing. The body weight, femoral length, aBMD, load to fracture, tissue volume, bone volume......, and tissue density were found to increase rapidly with age at 14–30 weeks. At the age of 30–42 weeks, the growth rate appeared to decrease. However, no accompanying changes were found in osteocyte lacunar properties such as lacunar volume, ellipsoidal radii, lacunar stretch, lacunar oblateness, or lacunar...... orientation with animal age. Hence, the evolution of organ and tissue level properties with age in rat cortical bone is not accompanied by related changes in osteocyte lacunar properties. This suggests that bone microstructure and bone matrix material properties and not the geometric properties...

  19. Lacunarity analysis of raster datasets and 1D, 2D, and 3D point patterns

    Science.gov (United States)

    Dong, Pinliang

    2009-10-01

    Spatial scale plays an important role in many fields. As a scale-dependent measure for spatial heterogeneity, lacunarity describes the distribution of gaps within a set at multiple scales. In Earth science, environmental science, and ecology, lacunarity has been increasingly used for multiscale modeling of spatial patterns. This paper presents the development and implementation of a geographic information system (GIS) software extension for lacunarity analysis of raster datasets and 1D, 2D, and 3D point patterns. Depending on the application requirement, lacunarity analysis can be performed in two modes: global mode or local mode. The extension works for: (1) binary (1-bit) and grey-scale datasets in any raster format supported by ArcGIS and (2) 1D, 2D, and 3D point datasets as shapefiles or geodatabase feature classes. For more effective measurement of lacunarity for different patterns or processes in raster datasets, the extension allows users to define an area of interest (AOI) in four different ways, including using a polygon in an existing feature layer. Additionally, directionality can be taken into account when grey-scale datasets are used for local lacunarity analysis. The methodology and graphical user interface (GUI) are described. The application of the extension is demonstrated using both simulated and real datasets, including Brodatz texture images, a Spaceborne Imaging Radar (SIR-C) image, simulated 1D points on a drainage network, and 3D random and clustered point patterns. The options of lacunarity analysis and the effects of polyline arrangement on lacunarity of 1D points are also discussed. Results from sample data suggest that the lacunarity analysis extension can be used for efficient modeling of spatial patterns at multiple scales.

  20. Airborne pollutants and lacunar stroke: a case cross-over analysis on stroke unit admissions.

    Science.gov (United States)

    Corea, Francesco; Silvestrelli, Giorgio; Baccarelli, Andrea; Giua, Alessandra; Previdi, Paolo; Siliprandi, Giorgio; Murgia, Nicola

    2012-06-14

    Particulate air pollution is known to be associated with cardiovascular disease. The relation of particulate air pollution with cerebrovascular disease (CVD) has not been extensively studied, particularly in relation to different subtypes of stroke. A time-series study was conducted to evaluate the association between daily air pollution and acute stroke unit hospitalizations in Mantua, Italy. We analyzed 781 CVD consecutive patients living in Mantua county admitted between 2006-08. Data on stroke types, demographic variables, risk factors were available from the Lombardia Stroke Registry. Daily mean value of particulate matter with a diameter <10 µm (PM(10)), carbon monoxide, nitric oxide, nitrogen dioxide, sulphur dioxide, benzene and ozone were used in the analysis. The association between CVD, ischemic strokes subtypes and pollutants was investigated with a case-crossover design, using conditional logistic regression analysis, adjusting for temperature, humidity, barometric pressure and holidays. Among the 781 subjects admitted 75.7% had ischemic stroke, 11.7% haemorrhagic stroke 12.6% transient ischemic attack. In men admission for stroke was associated with PM(10) [odds ratio (OR) 1.01, 95%; confidence interval (CI) 1.00-1.02; P<0.05]. According to the clinical classification, lacunar anterior circulation syndrome stroke type was related to PM(10) level registered on the day of admission for both genders (OR: 1.01, 95%; CI: 1.00-1.02; P<0.05) while for total anterior circulation syndrome stroke only in men (OR: 1.04, 95%; CI 1.01-1.07; P<0.05).In conclusion, our study confirms that air pollution peaks may contribute to increase the risk of hospitalization for stroke and particulate matter seems to be a significant risk factor, especially for lacunar stroke.

  1. Lacunar stroke in a teenager after minor head trauma: case report and literature review.

    Science.gov (United States)

    Zwank, Michael D; Dummer, Benjamin W; Danielson, Levi T; Haake, Bret C

    2014-09-01

    Ischemic strokes in children and young adults are fortunately rare. Contrasted with adult ischemic strokes, pediatric stroke etiologies vary greatly and are often unknown. Childhood lacunar strokes and trauma-induced strokes represent particularly uncommon subsets and have been reported infrequently in the literature. It is unique to find a combination of the 2-a lacunar stroke induced by trauma. Underreporting of these trauma-induced ischemic strokes could be responsible for perpetuating the lack of recognition. Here we present a lacunar stroke in a young woman associated with a water sport accident and explore relevant literature encircling deep brain ischemia coinciding with trauma.

  2. Increased inter-hemispheric resting-state functional connectivity in acute lacunar stroke patients with aphasia.

    Science.gov (United States)

    Yang, Haiqing; Bai, Lin; Zhou, Yi; Kang, Shan; Liang, Panpan; Wang, Lihua; Zhu, Yifei

    2017-03-01

    Aphasia is a devastating neurological condition affecting a person's ability to communicate and reintegrate into the society. It may occur in 20% or more of patients after stroke. The recovery of language function is accompanied by brain reorganization, and identifying the inter-hemispheric interaction post-stroke will conduce to more targeted treatments. Previous studies suggested that robust homotopic resting-state functional connectivity is a key characteristic of the brain's intrinsic functional architecture, and communication between the left and right cerebral hemispheres is important for language processing. In this study, voxel-mirrored homotopic connectivity (VMHC) was used to examine the inter-hemispheric resting-state functional connectivity (RSFC) differences between 37 patients with acute lacunar stroke in the left hemisphere and 28 healthy controls. Besides, correlation analyses were carried out to investigate the relationship between VMHC values of brain regions showing abnormal inter-hemispheric RSFC and clinical variables [i.e., aphasia quotient (AQ) scores, National Institutes of Health Stroke Scale (NIHSS) and Mini-Mental State Examination of patients]. Compared with healthy controls, patients showed significantly increased VMHC in the pars orbitalis of the inferior frontal gyrus, anterior part of the superior temporal gyrus (STG) and lingual gyrus. No brain region showed decreased VMHC in the patient group than in the healthy control group. The AQ scores were negatively correlated with VMHC values in the STG. NIHSS scores were positively correlated with VMHC values in the lingual gyrus. We hope these results could shed new insights into the pathology of aphasia in patients with acute lacunar stroke.

  3. Correlation between cerebral microbleeds and S100B/RAGE in acute lacunar stroke patients.

    Science.gov (United States)

    Xiao, Lulu; Sun, Wen; Lan, Wenya; Xiong, Yunyun; Duan, Zuowei; Zhang, Zongjun; Fan, Wenping; Xu, Lili; Xie, Xia; Ma, Nan; Ye, Ruidong; Xu, Gelin; Liu, Xinfeng; Zhu, Wusheng

    2014-05-15

    S100B and its scavenger, soluble receptor for advanced glycation end products (sRAGE), participate in various acute and chronic brain disorders. However, their impact on hemorrhage-prone small vessel disease represented by cerebral microbleeds (CMBs) is unclear. The purpose of this study was to investigate the relationship of CMBs with plasma S100B and sRAGE. A cohort of 147 consecutive patients with first-ever acute lacunar stroke was prospectively enrolled. We collected demographic, clinical, and laboratory data, including plasma levels of S100B and sRAGE, and presence and number of CMBs using susceptibility-weighted imaging (SWI). Associations between plasma S100B, sRAGE levels and the presence, number, and location of CMBs were determined. CMBs were present in 58 patients (39.5%). Each 1SD-increase in S100B and sRAGE levels was significantly associated with presence of CMBs (adjusted odds ratio [OR], 3.06; 95% confidence interval [CI], 1.81-5.17 and adjusted OR, 0.29; 95% CI, 0.16-0.53; respectively) and number of CMBs (adjusted relative risk [RR], 4.07; 95% CI, 3.60-5.65 for S100B and RR 0.34; 95% CI, 0.25-0.46 for sRAGE). When stratified by location, plasma S100B and sRAGE levels were similarly associated with presence of deep CMBs (adjusted OR, 3.65; 95% CI, 1.99-6.69 and adjusted OR, 0.23; 95% CI, 0.12-0.46; respectively), but not with strictly lobar CMBs. Higher levels of S100B and lower levels of sRAGE are independently associated with presence and number of CMBs in patients with first-ever acute lacunar stroke, particularly in those with deep CMBs. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Neuropsychological correlates of a right unilateral lacunar thalamic infarction

    Science.gov (United States)

    Werf, Y; Weerts, J; Jolles, J; Witter, M; Lindeboom, J; Scheltens, P.

    1999-01-01

    OBJECTIVES—To report on a patient with a lacunar infarction in the right intralaminar nuclei of the thalamus. The role of the thalamic intralaminar nuclei in cognitive function is as yet insufficiently known. The patient described has shown signs of apathy and loss of initiative, in combination with cognitive deficits, which have persisted essentially unaltered up to the present day since an abrupt onset 17 years ago.
METHODS—High resolution MRI was performed to show the extent of the lesion; a combination of published and experimental neuropsychological techniques was administered to show the nature of the cognitive defects; Single photon emission computed tomography (SPECT) was employed to obtain a measure of cortical perfusion.
RESULTS—Brain MRI disclosed an isolated lacunar infarction in the dorsal caudal intralaminar nuclei of the thalamus. Neuropsychological evaluation indicated problems with attention and concentration, executive disturbances, and memory deficits both in the visual and verbal domains. The memory deficits could not be attributed to problems in the early stages of information processing, and are hence regarded as resulting from a failure of retrieval rather than encoding or storage. Brain SPECT disclosed a hypoperfusion of the right frontal cortex.
CONCLUSION—The data indicate that the cognitive profile is the result of a dysfunction of executive functions. This is corroborated by the finding of decreased blood flow in the right frontal cortex, and by evidence from the neuroanatomical literature. Thus the dysexecutive symptoms are thought to be caused by disconnection of the prefrontal cortex from the brainstem activating nuclei through the strategic localisation of the right thalamic infarction.

 PMID:9886448

  5. Tug-of-war lacunarity—A novel approach for estimating lacunarity

    Science.gov (United States)

    Reiss, Martin A.; Lemmerer, Birgit; Hanslmeier, Arnold; Ahammer, Helmut

    2016-11-01

    Modern instrumentation provides us with massive repositories of digital images that will likely only increase in the future. Therefore, it has become increasingly important to automatize the analysis of digital images, e.g., with methods from pattern recognition. These methods aim to quantify the visual appearance of captured textures with quantitative measures. As such, lacunarity is a useful multi-scale measure of texture's heterogeneity but demands high computational efforts. Here we investigate a novel approach based on the tug-of-war algorithm, which estimates lacunarity in a single pass over the image. We computed lacunarity for theoretical and real world sample images, and found that the investigated approach is able to estimate lacunarity with low uncertainties. We conclude that the proposed method combines low computational efforts with high accuracy, and that its application may have utility in the analysis of high-resolution images.

  6. EVALUATION OF VERTICAL LACUNARITY PROFILES IN FORESTED AREAS USING AIRBORNE LASER SCANNING POINT CLOUDS

    Directory of Open Access Journals (Sweden)

    B. Székely

    2016-06-01

    Logarithms of lacunarity functions show canopy-related variations, we analysed these variations along transects. The spatial variation can be related to forest properties and ecology-specific aspects.

  7. Urban Textural Analysis from Remote Sensor Data: Lacunarity Measurements Based on the Differential Box Counting Method

    National Research Council Canada - National Science Library

    Myint, Soe W; Mesev, Victor; Lam, Nina

    2006-01-01

    ...‐cover classes from satellite sensor data. Our methodology focuses on two different gliding box methods to compute lacunarity values and demonstrate a mirror extension approach for a local moving window...

  8. Millennium Simulation Dark Matter Haloes: Multi-fractal and Lacunarity Analysis with Homogeneity Transition

    CERN Document Server

    Chacón-Cardona, César A

    2012-01-01

    We investigate from the fractal viewpoint the way in which the dark matter is grouped at z = 0 in the Millennium dark matter cosmological simulation. The determination of the cross to homogeneity in the Millennium Simulation data is described from the behaviour of the fractal dimension and the lacunarity. We use the sliding window technique to calculate the fractal mass-radius dimension, the pre-factor F and the lacunarity of this fractal relation. Besides, we determinate the multi-fractal dimension and the lacunarity spectrum, including their dependence with radial distance. This calculations show a radial distance dependency of all the fractal quantities, with heterogeneity clustering of dark matter haloes up to depths of 100 Mpc/h. The dark matter haloes clustering in the Millennium Simulation shows a radial distance dependency, with two regions clearly defined. The lacunarity spectrum for values of the structure parameter q >= 1 shows regions with relative maxima, revealing the formation of clusters and v...

  9. Impaired anticipatory control of fingertip forces in patients with a pure motor or sensorimotor lacunar syndrome

    National Research Council Canada - National Science Library

    Raghavan, Preeti; Krakauer, John W; Gordon, Andrew M

    2006-01-01

    We examined planning and execution of precision grasp in eight right-handed patients with a right pure motor or sensorimotor lacunar syndrome after a subcortical stroke and eight age-matched controls...

  10. Lacunarity analysis: A general technique for the analysis of spatial patterns

    Energy Technology Data Exchange (ETDEWEB)

    Plotnick, R.E. [Department of Geological Sciences, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607-7059 (United States); Gardner, R.H. [University of Maryland, Appalachian Environmental Laboratory, Frostburg, Maryland 21532 (United States); Hargrove, W.W. [Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6038 (United States); Prestegaard, K. [Department of Geology, University of Maryland, College Park, Maryland 20742 (United States); Perlmutter, M. [Energy Systems Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States)

    1996-05-01

    Lacunarity analysis is a multiscaled method for describing patterns of spatial dispersion. It can be used with both binary and quantitative data in one, two, and three dimensions. Although originally developed for fractal objects, the method is more general and can be readily used to describe nonfractal and multifractal patterns. Lacunarity analysis is broadly applicable to many data sets used in the natural sciences; we illustrate its application to both geological and ecological data. {copyright} {ital 1996 The American Physical Society.}

  11. Neural differentiation of transplanted neural stem cells in a rat model of striatal lacunar infarction: light and electron microscopic observations

    Science.gov (United States)

    Muñetón-Gómez, Vilma C.; Doncel-Pérez, Ernesto; Fernandez, Ana P.; Serrano, Julia; Pozo-Rodrigálvarez, Andrea; Vellosillo-Huerta, Lara; Taylor, Julian S.; Cardona-Gómez, Gloria P.; Nieto-Sampedro, Manuel; Martínez-Murillo, Ricardo

    2012-01-01

    The increased risk and prevalence of lacunar stroke and Parkinson's disease (PD) makes the search for better experimental models an important requirement for translational research. In this study we assess ischemic damage of the nigrostriatal pathway in a model of lacunar stroke evoked by damaging the perforating arteries in the territory of the substantia nigra (SN) of the rat after stereotaxic administration of endothelin-1 (ET-1), a potent vasoconstrictor peptide. We hypothesized that transplantation of neural stem cells (NSCs) with the capacity of differentiating into diverse cell types such as neurons and glia, but with limited proliferation potential, would constitute an alternative and/or adjuvant therapy for lacunar stroke. These cells showed neuritogenic activity in vitro and a high potential for neural differentiation. Light and electron microscopy immunocytochemistry was used to characterize GFP-positive neurons derived from the transplants. 48 h after ET-1 injection, we characterized an area of selective degeneration of dopaminergic neurons within the nigrostriatal pathway characterized with tissue necrosis and glial scar formation, with subsequent behavioral signs of Parkinsonism. Light microscopy showed that grafted cells within the striatal infarction zone differentiated with a high yield into mature glial cells (GFAP-positive) and neuron types present in the normal striatum. Electron microscopy revealed that NSCs-derived neurons integrated into the host circuitry establishing synaptic contacts, mostly of the asymmetric type. Astrocytes were closely associated with normal small-sized blood vessels in the area of infarct, suggesting a possible role in the regulation of the blood brain barrier and angiogenesis. Our results encourage the use of NSCs as a cell-replacement therapy for the treatment of human vascular Parkinsonism. PMID:22876219

  12. Neural differentiation of transplanted neural stem cells in a rat model of striatal lacunar infarction: light and electron microscopic observations

    Directory of Open Access Journals (Sweden)

    Vilma Consuelo Muñeton-Gomez

    2012-08-01

    Full Text Available The increased risk and prevalence of lacunar stroke and Parkinson's disease makes the search for better experimental models an important requirement for translational research. In this study we assess ischemic damage of the nigrostriatal pathway in a model of lacunar stroke evoked by damaging the perforating arteries in the territory of the substantia nigra of the rat after stereotaxic administration of endothelin-1, a potent vasoconstrictor peptide. We hypothesized that transplantation of neural stem cells (NSCs with the capacity of differentiating into diverse cell types such as neurons and glia, but with limited proliferation potential, would constitute an alternative and/or adjuvant therapy for lacunar stroke. These cells showed neuritogenic activity in vitro and a high potential for neural differentiation. Light and electron microscopy immunocytochemistry was used to characterize green fluorescent-derived neurons. 48h after endothelin-1 injection, we characterized an area of selective degeneration of dopaminergic neurons within the nigrostriatal pathway characterised with tissue necrosis and glial scar formation, with subsequent behavioral signs of Parkinsonism. Light microscopy showed that grafted cells within the striatal infarction zone differentiated with a high yield into mature glial cells (GFAP-positive and into neurons of diverse neurotransmitter-striatal subtypes, suggesting that they were functional. Electron microscopy revealed that NSCs-derived neurons integrated into the host circuitry establishing synaptic contacts, mostly of the asymmetric type. Astrocytes were closely associated with normal small-sized blood vessels in the area of infarct, suggesting their implication in angiogenesis during recovery from stroke. Our results encourage the use of NSCs as a cell-replacement therapy for the treatment of human vascular Parkinsonism.

  13. Genetic Associations With White Matter Hyperintensities Confer Risk of Lacunar Stroke.

    Science.gov (United States)

    Traylor, Matthew; Rutten-Jacobs, Loes C A; Thijs, Vincent; Holliday, Elizabeth G; Levi, Chris; Bevan, Steve; Malik, Rainer; Boncoraglio, Giorgio; Sudlow, Cathie; Rothwell, Peter M; Dichgans, Martin; Markus, Hugh S

    2016-05-01

    White matter hyperintensities (WMH) are increased in patients with lacunar stroke. Whether this is because of shared pathogenesis remains unknown. Using genetic data, we evaluated whether WMH-associated genetic susceptibility factors confer risk of lacunar stroke, and therefore whether they share pathogenesis. We used a genetic risk score approach to test whether single nucleotide polymorphisms associated with WMH in community populations were associated with magnetic resonance imaging-confirmed lacunar stroke (n=1,373), as well as cardioembolic (n=1,331) and large vessel (n=1,472) Trial of Org 10172 in Acute Stroke Treatment subtypes, against 9,053 controls. Second, we separated lacunar strokes into those with WMH (n=568) and those without (n=787) and tested for association with the risk score in these 2 groups. In addition, we evaluated whether WMH-associated single nucleotide polymorphisms are associated with lacunar stroke, or in the 2 groups. The WMH genetic risk score was associated with lacunar stroke (odds ratio [OR; 95% confidence interval [CI

  14. The relation between prognosis and nocturnal blood pressure variation in hypertensive patients with lacunar infarct%夜间血液变化与高血压腔隙性脑梗死发后及预后的相关性分析

    Institute of Scientific and Technical Information of China (English)

    张微微; 黄勇华; 李娟; 冯军

    2001-01-01

    Objective We conducted a study using MRI and ambulatory blood pressure monitoring(ABPM) to determine whether an inapporpriately low nocturnal blood pressure,or an excess fall in nocturnal blood pressure,might be responsible for lacunar infarct.Method ABPM and Casul blood pressure(CBP) were examined in 35 hypertentives with lacunar infarct( LI) and 33 hypertentives without lacunar infarct as control group.Results There is no significant difference of CBP between two groups.But the mean nighttime systolic blood pressure(nSBP) and diastolic blood pressure(nDBP) in patients with lacunar infarct were significantly smaller than in patients without lacunar infarct.The ratio of nSBP/dSBP and nDBP/dDBP in SI were smaller than in control group respectively.Conclusions The results indicate that an inappropriately low nocturnal blood pressure,or an excessive fall in nocturnal blood pressure,is associated with lacunar infarct.It is necessary not only to controlhigh blood pressure but also to pay attention to circadian changes of blood pressure during the course of anti-hypertensive treatment.

  15. Identifying mangrove species and their surrounding land use and land cover classes using object-oriented approach with a lacunarity spatial measure

    Science.gov (United States)

    Myint, S.W.; Giri, C.P.; Wang, L.; Zhu, Z.; Gillete, S.C.

    2008-01-01

    Accurate and reliable information on the spatial distribution of mangrove species is needed for a wide variety of applications, including sustainable management of mangrove forests, conservation and reserve planning, ecological and biogeographical studies, and invasive species management. Remotely sensed data have been used for such purposes with mixed results. Our study employed an object-oriented approach with the use of a lacunarity technique to identify different mangrove species and their surrounding land use and land cover classes in a tsunami-affected area of Thailand using Landsat satellite data. Our results showed that the object-oriented approach with lacunarity-transformed bands is more accurate (over-all accuracy 94.2%; kappa coefficient = 0.91) than traditional per-pixel classifiers (overall accuracy 62.8%; and kappa coefficient = 0.57). Copyright ?? 2008 by Bellwether Publishing, Ltd. All rights reserved.

  16. Identifying mangrove species and their surrounding land use and land cover classes using object-oriented approach with a lacunarity spatial measure

    Science.gov (United States)

    Myint, S.W.; Giri, C.P.; Wang, L.; Zhu, Z.; Gillete, S.C.

    2008-01-01

    Accurate and reliable information on the spatial distribution of mangrove species is needed for a wide variety of applications, including sustainable management of mangrove forests, conservation and reserve planning, ecological and biogeographical studies, and invasive species management. Remotely sensed data have been used for such purposes with mixed results. Our study employed an object-oriented approach with the use of a lacunarity technique to identify different mangrove species and their surrounding land use and land cover classes in a tsunami-affected area of Thailand using Landsat satellite data. Our results showed that the object-oriented approach with lacunarity-transformed bands is more accurate (over-all accuracy 94.2%; kappa coefficient = 0.91) than traditional per-pixel classifiers (overall accuracy 62.8%; and kappa coefficient = 0.57). Copyright ?? 2008 by Bellwether Publishing, Ltd. All rights reserved.

  17. The usefulness of diffusion-weighted/fluid-attenuated inversion recovery imaging in the diagnostics and timing of lacunar and nonlacunar stroke

    Energy Technology Data Exchange (ETDEWEB)

    Witkowski, Grzegorz; Sienkiewicz-Jarosz, Halina [Institute of Psychiatry and Neurology, 1st Department of Neurology, Warsaw (Poland); Piliszek, Agnieszka; Ryglewicz, Danuta [Central Clinical Hospital of the Ministry of Interior, Department of Radiology, Warsaw (Poland); Skierczynska, Agnieszka; Poniatowska, Renata [Institute of Psychiatry and Neurology, Department of Radiology, Warsaw (Poland); Dorobek, Malgorzata; Filipek-Gliszczynska, Anna [Central Clinical Hospital of the Ministry of Interior, Department of Neurology, Warsaw (Poland); Walecki, Jerzy [Polish Academy of Science, Mossakowski Medical Research Centre, Warsaw (Poland)

    2014-10-15

    The DWI/FLAIR mismatch is a potential radiological marker for the timing of stroke onset. The aim of the study was to assess if the DWI/FLAIR mismatch can help to identify patients with both lacunar and nonlacunar acute ischemic stroke within 4.5 h of onset. A retrospective study was performed in which the authors analysed data from 86 ischemic lacunar and nonlacunar stroke patients with a known time of symptom onset, imaged within the first 24 h from stroke onset (36 patients <4.5 h, 14 patients 4.5-6 h, 15 patients 6-12 h, and 21 patients 12-24 h). Patients underwent the admission CT and MR scan. The presence of lesions was assessed in correlation with the duration of the stroke. The time from stroke onset to neuroimaging was significantly shorter in patients with an ischemic lesion visible only in the DWI (mean 2.78 h, n = 24) as compared to patients with signs of ischemia also in other modalities (mean 8.6 h, n = 62) (p = 0.0001, Kruskal-Wallis ANOVA). The DWI/FLAIR mismatch was characterised by a global sensitivity of 58 %, specificity 94 %, PPV 87.5 %, and NPV 76 % in identifying patients in the 4.5 h thrombolysis time window. For lacunar strokes (n = 20), these parameters were as follows: sensitivity 50 %, specificity 92.8 %, PPV 75 %, and NPV 81.2 %. The presence of acute ischemic lesions only in DWI can help to identify both lacunar and nonlacunar stroke patients who are in the 4.5 h time window for intravenous thrombolysis with high specificity. (orig.)

  18. Lacunar infarcts in childhood. Clinical and computed tomographic correlations

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Chizuko; Eda, Isematsu; Takashima, Sachio; Takeshita, Kenzo (Tottori Univ., Yonago (Japan). School of Medicine); Kanetoh, Yasuko

    1984-09-01

    Nine cases, ranging in age from 6 months to 9 years, were diagnosed as lacunar infarcts on computed tomography (CT). Hemiplegia developed rapidly or gradually in 8 cases. Three of 8 cases had transient ischemic attacks of hemiplegia. Other neurological deficits were dysarthria, aphasia, confusion and coarse tremor. One case was asymptomatic. Each of 8 cases had single lacuna and one case two lacunae on CT. These lacunae were localized in the internal capsule, the putamen or the caudate nucleus. Lacunae involving the internal capsule were associated with contralateral hemiplegia, whereas asymptomatic lacunae did not involve it. Severity of hemiplegia in the acute stage did not correlate with localization or size of lacunae. Moderate neurological sequelae were noticed in 3 cases, mild sequelae in two and none in three. The sequelae were related to the lacunae which involved the lateral lenticulostriate branch zone of the middle cerebral artery or larger areas. Prognosis did not correlate with the mode of onset or the severity of neurological signs in the acute stage. There were 2 cases with the occlusion of the left internal carotid artery or congenital heart disease, but the etiology of lacunae was unknown in the other cases.

  19. Correlation between transcranial Doppler blood flow parameters and degree of nerve injury, degree of inflammation as well as Hcy metabolism in patients with lacunar infarction

    Institute of Scientific and Technical Information of China (English)

    Li Liang; Jin-Hua Su; Hai-Yan Kou

    2016-01-01

    Objective:To study the correlation between transcranial Doppler blood flow parameters and the degree of nerve injury, the degree of inflammation as well as Hcy metabolism in patients with lacunar infarction.Methods:A total of 88 patients diagnosed with lacunar infarction (LI) in our hospital between May 2013 and December 2015 were selected as LI group and 100 healthy volunteers receiving physical examination during the same period were selected as control group. Transcranial Doppler was used to measure the blood flow parameters of middle cerebral artery and basilar artery, and serum was collected to determine nerve injury molecules, inflammation indexes and Hcy metabolism indexes.Results:Middle cerebral artery MFV and PI as well as basal artery MFV and PI of LI group were significantly higher than those of control group; serum NSE, S100B, UCH-L1, ox-LDL, MMP-9, sCD40L, IL-18 and Hcy content of LI group were significantly higher than those of control group and positively correlated with middle cerebral artery and basilar artery MFV and PI while folic acid and vitamin B12 content were significantly lower than those of control group and negatively correlated with middle cerebral artery and basilar artery MFV and PI.Conclusions:Middle cerebral artery and basilar artery flow is accelerated and the pulsatility is enhanced in patients with lacunar infarction, and the changes of intracranial artery flow parameters are closely related to the degree of nerve injury, the degree of inflammation and Hcy metabolism.

  20. Millennium simulation dark matter haloes: multifractal and lacunarity analysis and the transition to homogeneity

    Science.gov (United States)

    Chacón-Cardona, C. A.; Casas-Miranda, R. A.

    2012-12-01

    We investigate from a fractal viewpoint the way in which dark matter is grouped at z = 0 in the Millennium dark matter cosmological simulation. Determination of the crossing point to homogeneity in the Millennium Simulation data is described with regard to the behaviour of the fractal dimension and lacunarity. We use the sliding-window technique to calculate the fractal mass-radius dimension, the pre-factor F and the lacunarity of this fractal relation. Additionally, we determine the multifractal dimension and the lacunarity spectrum, including their dependence on radial distance. The calculations show a radial distance dependence of all fractal quantities, with heterogeneous clustering of dark matter haloes up to depths of 100 Mpc h-1. Dark matter halo clustering in the Millennium Simulation shows a radial distance dependence, with two regions clearly defined. The lacunarity spectrum for values of the structure parameter q ≥ 1 shows regions with relative maxima, revealing the formation of clusters and voids in the dark matter halo distribution. With use of the multifractal dimension and the lacunarity spectrum, the transition to homogeneity at depths between 100 Mpc h-1 and 120 Mpc h-1 for Millennium Simulation dark matter haloes is detected.

  1. Efficacy of antiplatelet therapy for treating lacunar infarct: Meta-analysis

    Directory of Open Access Journals (Sweden)

    Da XU

    2017-03-01

    Full Text Available   Objective To evaluate the efficacy of antiplatelet agents in secondary prevention of patients with lacunar infarct (LACI. Methods Retrieve relevant randomized controlled trials (RCTs that reported antiplatelet therapy in patients with LACI from online databases (January 1, 1980-November 20, 2016 in PubMed, EMBASE/SCOPUS and Cochrane Online Library with key words: stroke, lacunar infarction, platelet aggregation inhibitors, antiplatelet, randomized controlled trial. Quality of studies was evaluated by using Jadad Scale and Cochrane Handbook for Systematic Reviews of Interventions. All data were pooled by RevMan 5.3 software for Meta-analysis. A network Meta-analysis was done by R software Gemtc and JAGS software. Results A total of 4068 articles were enrolled and 12 high - quality RCTs (Jadad ≥ 4 scores with 24 969 eligible participants were finally included after excluding duplicates and those not meeting the inclusion criteria. Meta-analysis showed single antiplatelet therapy was more effective than placebo in reducing ischemic stroke recurrence rate (RR = 0.480, 95%CI: 0.300-0.780; P = 0.003 and any stroke recurrence rate (RR = 0.780, 95%CI: 0.630-0.970; P = 0.030. The efficacy of single antiplatelet therapy was not significantly different from that of dual antiplatelet therapy (ischemic stroke recurrence rate: RR = 0.900, 95%CI: 0.760-1.050, P = 0.170; any stroke recurrence rate: RR = 0.910, 95%CI: 0.820-1.010, P = 0.070. Network Meta-analysis (four interventions including aspirin, placebo, cilostazol and ticlopidine showed that cilostazol was associated with a significant reduction in recurrence of any stroke compared with aspirin (OR = 0.341, 95% CrI: 0.011-0.673 and placebo (OR = 0.615, 95% CrI: 0.191-1.042. Conclusions Single antiplatelet therapy could significantly reduce the recurrence of any stroke, especially ischemic stroke in patients with LACI. There is no evidence showing that dual antiplatelet therapy is probably better

  2. Combination of fractional Brownian random field and lacunarity for iris recognition

    Science.gov (United States)

    Liu, Kai; Zhou, Weidong; Wang, Yu

    2011-10-01

    Feature extraction plays a vital role in iris recognition, affecting the performance of iris recognition algorithm strongly. In this paper, we present an individual recognition algorithm using fractal dimension based on fractional Brownian random field and lacunarity in feature extraction. Making use of the fractal feature of iris, such as self-similarity and random patterns, fractal dimension can extract texture information effectively. Lacunarity overcomes the limitation of fractal dimension that fractal sets with different textures may share the same fractal dimension value. The combination of fractal dimension and lacunarity makes the feature extraction more comprehensive and distinguishable. The experimental results show that this recognition algorithm can obtain great performance on CASIA 1.0 iris database

  3. Lacunar Infarction Associated with Anabolic Steroids and Polycythemia: A Case Report

    Directory of Open Access Journals (Sweden)

    George W.J. Harston

    2014-02-01

    Full Text Available Lacunar infarction is traditionally ascribed to lipohyalinosis or microatheroma. We report the case of 40-year-old man, without traditional risk factors for ischemic stroke, who presented to the Emergency Department with recurrent episodes of transient right-sided weakness and paresthesia. Lacunar infarction was confirmed on diffusion-weighted MRI and blood tests showed a marked polycythemia. Quantitative magnetic resonance perfusion imaging demonstrated dramatically abnormal perfusion throughout both cerebral hemispheres, and transcranial Doppler revealed reduced cerebral artery velocities, both consistent with the proposed mechanism of hyperviscosity. His symptoms settled with treatment of the polycythemia and workup did not find another cause of ischemic stroke. We propose that hyperviscosity secondary to steroid-induced polycythemia caused ischemia in this case and not lipohyalinosis or microatheroma, to which lacunar disease is commonly attributed.

  4. Acute lacunar infarcts in CLIPPERS: is the chronic infiltrative lymphocytic perivascular disease process to blame?

    Science.gov (United States)

    Saigal, Gaurav; Quencer, Robert

    2013-12-01

    CLIPPERS (chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids) is a recently described chronic inflammatory disorder involving the brainstem with characteristic imaging findings. Since it was originally described in 2002, only a handful of cases have been reported in the literature. We describe two additional cases of CLIPPERS with characteristic clinical and radiological findings. Besides the previously described MR findings, one of the cases also demonstrated multiple basal ganglia lacunar infarcts, a finding which has not been previously reported. We hypothesize that the lacunar infarcts are caused by this chronic infiltrative perivascular disease process.

  5. Plasma tPA-Activity and Progression of Cerebral White Matter Hyperintensities in Lacunar Stroke Patients

    Science.gov (United States)

    van Overbeek, Ellen C.; Staals, Julie; Knottnerus, Iris L. H.; ten Cate, Hugo; van Oostenbrugge, Robert J.

    2016-01-01

    Introduction Tissue plasminogen activator (tPA)-activity and plasminogen activator inhibitor type 1 (PAI-1) antigen are considered to be haemostasis-related markers of endothelial activation and relate to presence of cerebral white matter hyperintensities (WMH) as was earlier shown in a cross-sectional study. We investigated whether tPA-activity and PAI-1 levels are associated with WMH progression in a longitudinal study. Methods In 127 first-ever lacunar stroke patients in whom baseline brain MRI and plasma levels of tPA-activity and PAI-1-antigen were available, we obtained a 2-year follow-up MRI. We assessed WMH progression by a visual WMH change scale. We determined the relationship between levels of tPA-activity and PAI-1 and WMH progression, by logistic regression analysis. Results Plasma tPA-activity was associated with periventricular WMH progression (OR 2.36, 95% CI 1.01–5.49, with correction for age and sex and baseline presence of WMH), but not with deep or any (periventricular and/or deep) WMH progression. PAI-1 levels were lower in patients with WMH progression, but these results were not significant. Conclusion We found a relationship between plasma tPA-activity and progression of periventricular WMH. More research is needed to determine whether there is a (direct) role of tPA in the development and progression of WMH. PMID:26942412

  6. Plasma tPA-Activity and Progression of Cerebral White Matter Hyperintensities in Lacunar Stroke Patients.

    Directory of Open Access Journals (Sweden)

    Ellen C van Overbeek

    Full Text Available Tissue plasminogen activator (tPA-activity and plasminogen activator inhibitor type 1 (PAI-1 antigen are considered to be haemostasis-related markers of endothelial activation and relate to presence of cerebral white matter hyperintensities (WMH as was earlier shown in a cross-sectional study. We investigated whether tPA-activity and PAI-1 levels are associated with WMH progression in a longitudinal study.In 127 first-ever lacunar stroke patients in whom baseline brain MRI and plasma levels of tPA-activity and PAI-1-antigen were available, we obtained a 2-year follow-up MRI. We assessed WMH progression by a visual WMH change scale. We determined the relationship between levels of tPA-activity and PAI-1 and WMH progression, by logistic regression analysis.Plasma tPA-activity was associated with periventricular WMH progression (OR 2.36, 95% CI 1.01-5.49, with correction for age and sex and baseline presence of WMH, but not with deep or any (periventricular and/or deep WMH progression. PAI-1 levels were lower in patients with WMH progression, but these results were not significant.We found a relationship between plasma tPA-activity and progression of periventricular WMH. More research is needed to determine whether there is a (direct role of tPA in the development and progression of WMH.

  7. A morphological analysis on the osteocytic lacunar canalicular system in bone surrounding dental implants.

    Science.gov (United States)

    Haga, Maiko; Nozawa-Inoue, Kayoko; Li, Minqi; Oda, Kimimitsu; Yoshie, Sumio; Amizuka, Norio; Maeda, Takeyasu

    2011-06-01

    Osseointegration is the most preferable interface of dental implants and newly formed bone. However, the cavity preparation for dental implants often gives rise to empty lacunae or pyknotic osteocytes in bone surrounding the dental implant. This study aimed to examine the chronological alternation of osteocytes in the bone surrounding the titanium implants using a rat model. The distribution of the osteocytic lacunar canalicular system (OLCS) in bone around the titanium implants was examined by silver impregnation according to Bodian's staining. We also performed double staining for alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP), as well as immunohistochemistry for fibroblast growth factor (FGF) 23--a regulator for the serum concentration of phosphorus--and sclerostin, which has been shown to inhibit osteoblastic activities. Newly formed bone and the injured bone at the early stage exhibited an irregularly distributed OLCS and a few osteocytes positive for sclerostin or FGF23, therefore indicating immature bone. Osteocytes in the surrounding bone from Day 20 to Month 2 came to reveal an intense immunoreactivity for sclerostin. Later on, the physiological bone remodeling gradually replaced such immature bone into a compact profile bearing a regularly arranged OLCS. As the bone was remodeled, FGF23 immunoreactivity became more intense, but sclerostin became less so in the well-arranged OLCS. In summary, it seems likely that OLCS in the bone surrounding the dental implants is damaged by cavity formation, but later gradually recovers as bone remodeling takes place, ultimately inducing mature bone. Copyright © 2011 Wiley-Liss, Inc.

  8. Lacunarity analysis: a promising method for the automated assessment of melanocytic naevi and melanoma.

    Science.gov (United States)

    Gilmore, Stephen; Hofmann-Wellenhof, Rainer; Muir, Jim; Soyer, H Peter

    2009-10-13

    The early diagnosis of melanoma is critical to achieving reduced mortality and increased survival. Although clinical examination is currently the method of choice for melanocytic lesion assessment, there is a growing interest among clinicians regarding the potential diagnostic utility of computerised image analysis. Recognising that there exist significant shortcomings in currently available algorithms, we are motivated to investigate the utility of lacunarity, a simple statistical measure previously used in geology and other fields for the analysis of fractal and multi-scaled images, in the automated assessment of melanocytic naevi and melanoma. Digitised dermoscopic images of 111 benign melanocytic naevi, 99 dysplastic naevi and 102 melanomas were obtained over the period 2003 to 2008, and subject to lacunarity analysis. We found the lacunarity algorithm could accurately distinguish melanoma from benign melanocytic naevi or non-melanoma without introducing many of the limitations associated with other previously reported diagnostic algorithms. Lacunarity analysis suggests an ordering of irregularity in melanocytic lesions, and we suggest the clinical application of this ordering may have utility in the naked-eye dermoscopic diagnosis of early melanoma.

  9. Lacunarity analysis: a promising method for the automated assessment of melanocytic naevi and melanoma.

    Directory of Open Access Journals (Sweden)

    Stephen Gilmore

    Full Text Available The early diagnosis of melanoma is critical to achieving reduced mortality and increased survival. Although clinical examination is currently the method of choice for melanocytic lesion assessment, there is a growing interest among clinicians regarding the potential diagnostic utility of computerised image analysis. Recognising that there exist significant shortcomings in currently available algorithms, we are motivated to investigate the utility of lacunarity, a simple statistical measure previously used in geology and other fields for the analysis of fractal and multi-scaled images, in the automated assessment of melanocytic naevi and melanoma. Digitised dermoscopic images of 111 benign melanocytic naevi, 99 dysplastic naevi and 102 melanomas were obtained over the period 2003 to 2008, and subject to lacunarity analysis. We found the lacunarity algorithm could accurately distinguish melanoma from benign melanocytic naevi or non-melanoma without introducing many of the limitations associated with other previously reported diagnostic algorithms. Lacunarity analysis suggests an ordering of irregularity in melanocytic lesions, and we suggest the clinical application of this ordering may have utility in the naked-eye dermoscopic diagnosis of early melanoma.

  10. Fractal dimension and lacunarity of tumor microscopic images as prognostic indicators of clinical outcome in early breast cancer.

    Science.gov (United States)

    Pribic, Jelena; Vasiljevic, Jelena; Kanjer, Ksenija; Konstantinovic, Zora Neskovic; Milosevic, Nebojsa T; Vukosavljevic, Dragica Nikolic; Radulovic, Marko

    2015-01-01

    Research in the field of breast cancer outcome prognosis has been focused on molecular biomarkers, while neglecting the discovery of novel tumor histology structural clues. We thus aimed to improve breast cancer prognosis by fractal analysis of tumor histomorphology. This retrospective study included 92 breast cancer patients without systemic treatment. Fractal dimension and lacunarity of the breast tumor microscopic histology possess prognostic value comparable to the major clinicopathological prognostic parameters. Fractal analysis was performed for the first time on routinely produced archived pan-tissue stained primary breast tumor sections, indicating its potential for clinical use as a simple and cost-effective prognostic indicator of distant metastasis risk to complement the molecular approaches for cancer risk prognosis.

  11. Prognostic Relationships between Microbleed, Lacunar Infarction, White Matter Lesion, and Renal Dysfunction in Acute Ischemic Stroke Survivors.

    Science.gov (United States)

    Jeon, Jae Woong; Jeong, Hye Seon; Choi, Dae Eun; Ham, Young Rok; Na, Ki Ryang; Lee, Kang Wook; Shin, Jong Wook; Kim, Jei

    2017-02-01

    It is well known that renal dysfunction and cerebral small-vessel disease (SVD), including microbleed, lacunar infarction, and white matter lesion (WML), are associated with poor prognosis after ischemic stroke. However, the prognostic relationship between renal dysfunction and SVD has not been well evaluated in acute ischemic stroke survivors. Therefore, in this study, we evaluated the prognostic relationships between estimated glomerular filtration rate (eGFR) and cerebral SVD after acute ischemic stroke. We retrospectively reviewed the clinical and radiological data of acute ischemic stroke survivors with decreased eGFR (acute ischemic stroke survivors. Both renal impairment and the presence of SVD were predictors of poor poststroke survival. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  12. Evaluation of Vertical Lacunarity Profiles in Forested Areas Using Airborne Laser Scanning Point Clouds

    Science.gov (United States)

    Székely, B.; Kania, A.; Standovár, T.; Heilmeier, H.

    2016-06-01

    The horizontal variation and vertical layering of the vegetation are important properties of the canopy structure determining the habitat; three-dimensional (3D) distribution of objects (shrub layers, understory vegetation, etc.) is related to the environmental factors (e.g., illumination, visibility). It has been shown that gaps in forests, mosaic-like structures are essential to biodiversity; various methods have been introduced to quantify this property. As the distribution of gaps in the vegetation is a multi-scale phenomenon, in order to capture it in its entirety, scale-independent methods are preferred; one of these is the calculation of lacunarity. We used Airborne Laser Scanning point clouds measured over a forest plantation situated in a former floodplain. The flat topographic relief ensured that the tree growth is independent of the topographic effects. The tree pattern in the plantation crops provided various quasi-regular and irregular patterns, as well as various ages of the stands. The point clouds were voxelized and layers of voxels were considered as images for two-dimensional input. These images calculated for a certain vicinity of reference points were taken as images for the computation of lacunarity curves, providing a stack of lacunarity curves for each reference points. These sets of curves have been compared to reveal spatial changes of this property. As the dynamic range of the lacunarity values is very large, the natural logarithms of the values were considered. Logarithms of lacunarity functions show canopy-related variations, we analysed these variations along transects. The spatial variation can be related to forest properties and ecology-specific aspects.

  13. Airborne pollutants and lacunar stroke. A case cross-over analysis on stroke unit admissions

    Directory of Open Access Journals (Sweden)

    Nicola Murgia

    2012-06-01

    Full Text Available Particulate air pollution is known to be associated with cardiovascular disease. The relation of particulate air pollution with cerebrovascular disease (CVD has not been extensively studied, particularly in relation to different subtypes of stroke. A time-series study was conducted to evaluate the association between daily air pollution and acute stroke unit hospitalizations in Mantua county (Italy. We analyzed 781 CVD consecutive patients living in Mantua county admitted between 2006-08. Data on stroke types, demographic variables, risk factors were available from the Lombardia Stroke Registry. Daily mean value of particulate matter with a diameter < 10 μm (PM10, carbon monoxide, nitric oxide, nitrogen dioxide, sulphur dioxide, benzene and ozone were used in the analysis. The association between CVD, ischemic strokes subtypes and pollutants was investigated with a casecrossover design, using conditional logistic regression analysis, adjusting for temperature, humidity, barometric pressure and holidays. Among the 781 subjects admitted 75.7% had ischemic stroke, 11.7% haemorrhagic stroke 12.6% transient ischemic attack. In men admission for stroke was associated with PM10 (OR 1.01, 95% CI 1.00-1.02, p<0.05 . According to the clinical classification, LACI stroke type was related to PM10 level registered on the day of admission for both genders (OR 1.01, 95% CI 1.00-1.02, p<0.05 while for TACI stroke only in men (OR: 1.04, 95% CI 1.01-1.07, p<0.05. Our study confirms that air pollution peaks may contribute to increase the risk of hospitalization for stroke and particulate matter seems to be a significant risk factor, especially for lacunar stroke.

  14. Validity of apparent diffusion coefficient hyperpolarized 3He-MRI using MSCT and pulmonary function tests as references

    DEFF Research Database (Denmark)

    Diaz, Sandra; Casselbrant, Ingrid; Piitulainen, Eeva;

    2008-01-01

    PURPOSE: To compare apparent diffusion coefficient (ADC) measurements from hyperpolarized (HP) helium ((3)He)-magnetic resonance imaging (MRI) with quantitative data from multislice Computed Tomography (CT) (MSCT) of the whole lungs and pulmonary function tests (PFT). MATERIALS AND METHODS: Twenty...... from MSCT. Both mean ADC and MSCT data were compared to PFT, especially percent of predicted diffusing capacity of carbon monoxide (%predicted DLCO), using Pearson's correlation test. RESULTS: Mean ADC and standard deviation values were 0.392+/-0.119 cm(2)/s for the established emphysema group and 0...

  15. Local connected fractal dimensions and lacunarity analyses of 60 degrees fluorescein angiograms.

    Science.gov (United States)

    Landini, G; Murray, P I; Misson, G P

    1995-12-01

    The retinal vascular tree exhibits fractal characteristics. These findings relate to the mechanisms involved in the vascularization process and to the objective morphologic characterization of retinal vessels using fractal analysis. Although normal retinas show uniform patterns of blood vessels, in pathologic retinas with central vein or artery occlusions, the patterns are irregular. Because the generalized box fractal dimension fails to differentiate successfully between normal and abnormal retinal vessels in 60 degrees fluorescein angiograms, the authors have further investigated this problem using the local connected fractal dimension (alpha). The authors studied 24 digitized 60 degrees fluorescein angiograms of patients with normal retinas and 5 angiograms of patients with central retinal vein or artery occlusion. The pointwise method estimated the local complexity of the angiogram within a finite window centered on those pixels that belong to the retinal vessels. Color-coded dimensional images of the angiograms were constructed by plotting the pixels forming the object with a color that corresponded to specific values of alpha +/- delta alpha. The color-coded representation allowed recognition of areas with increased or decreased local angiogram complexity. The alpha distributions showed differences between normal and pathologic retinas, which overcomes problems encountered when using the methods of calculating the generalized fractal dimensions. A multivariate linear discriminant function using parameters from the alpha distribution and a further fractal parameter--lacunarity--reclassified 23 of the 24 normal and 4 of the 5 pathologic angiograms in their original groups (total: 92.1% correct). This methodology may be used for automatic detection and objective characterization of local retinal vessel abnormalities.

  16. Perfusion-weighted imaging and dynamic 4D angiograms for the estimation of collateral blood flow in lacunar infarction.

    Science.gov (United States)

    Förster, Alex; Mürle, Bettina; Böhme, Johannes; Al-Zghloul, Mansour; Kerl, Hans U; Wenz, Holger; Groden, Christoph

    2016-10-01

    Although lacunar infarction accounts for approximately 25% of ischemic strokes, collateral blood flow through anastomoses is not well evaluated in lacunar infarction. In 111 lacunar infarction patients, we analyzed diffusion-weighted images, perfusion-weighted images, and blood flow on dynamic four-dimensional angiograms generated by use of Signal Processing In NMR-Software. Blood flow was classified as absent (type 1), from periphery to center (type 2), from center to periphery (type 3), and combination of type 2 and 3 (type 4). On diffusion-weighted images, lacunar infarction was found in the basal ganglia (11.7%), internal capsule (24.3%), corona radiata (30.6%), thalamus (24.3%), and brainstem (9.0%). In 58 (52.2%) patients, perfusion-weighted image showed a circumscribed hypoperfusion, in one (0.9%) a circumscribed hyperperfusion, whereas the remainder was normal. In 36 (62.1%) patients, a larger perfusion deficit (>7 mm) was observed. In these, blood flow was classified type 1 in four (11.1%), 2 in 17 (47.2%), 3 in 9 (25.0%), and 4 in six (16.7%) patients. Patients with lacunar infarction in the posterior circulation more often demonstrated blood flow type 2 and less often type 3 (p = 0.01). Detailed examination and graduation of blood flow in lacunar infarction by use of dynamic four-dimensional angiograms is feasible and may serve for a better characterization of this stroke subtype.

  17. Lacunarity analysis of atomic configurations: Application to ethanol-water mixtures

    Science.gov (United States)

    Gereben, Orsolya

    2015-09-01

    Lacunarity analysis is a scale-dependent method quantifying the translational invariance in patterns. In this work it is used to characterize the distribution of several subsets of atoms in molecular systems. Binary clusters and one-component (ethanol or water) hydrogen-bonded clusters of ethanol-water mixtures with 0 -100 mol % ethanol content were analyzed. Molecular dynamics simulations created the configurations, and all were in good agreement with the respective experimental x-ray diffraction data. Lacunarity analysis revealed that the placement of the one-component clusters at low concentration can be described by a multifractal distribution, especially in the case of ethanol. Most of the cases these clusters are not isolated entities, but form islands in binary clusters.

  18. Epileptic Seizure Detection Using Lacunarity and Bayesian Linear Discriminant Analysis in Intracranial EEG.

    Science.gov (United States)

    Zhou, Weidong; Liu, Yinxia; Yuan, Qi; Li, Xueli

    2013-12-01

    Automatic seizure detection plays an important role in long-term epilepsy monitoring, and seizure detection algorithms have been intensively investigated over the years. This paper proposes an algorithm for seizure detection using lacunarity and Bayesian linear discriminant analysis (BLDA) in long-term intracranial EEG. Lacunarity is a measure of heterogeneity for a fractal. The proposed method first conducts wavelet decomposition on EEGs with five scales, and selects the wavelet coefficients at scale 3, 4, and 5 for subsequent processing. Effective features including lacunarity and fluctuation index are extracted from the selected three scales, and then sent into the BLDA for training and classification. Finally, postprocessing which includes smoothing, threshold judgment, multichannels integration, and collar technique is applied to obtain high sensitivity and low false detection rate. The proposed algorithm is evaluated on 289.14 h intracranial EEG data from 21-patient Freiburg dataset and yields a sensitivity of 96.25% and a false detection rate of 0.13/h with a mean delay time of 13.8 s.

  19. Surface Deformation Analysis by Means of Fractal Dimension and Lacunarity Approaches

    Science.gov (United States)

    Mahmood, S.; Shahzad, F.; Glaouguen, R.

    2009-05-01

    Fractals and scaling laws such as river networks and runoff series are abundant in nature, and geometry of river networks and basins is a superb example of this. The unrelenting competition between tectonics, surface uplift and erosional processes on the earth has resulted in a variety of drainage patterns by linearizing the normal flow patterns of river networks. These patterns are fractals and their variable spatial distribution can be used to examine the vulnerability of surface deformation. At first we extract the drainage network from Shuttle Radar Topographic Mission's digital elevation data (SRTM-90m) using D8 algorithm. We convert the drainage network into a binary image where the area of interests (AOIs) i.e. drainage are represented with pixels value of 1. The fractal dimension (D) analysis using Box Counting method is used to identify the anomalous drainage patterns of vulnerable sites. We prepare a D distribution map using a moving window of 1 arc sec. by 1 arc sec. on the binary image of river network. The space occupied by AOIs reveals variable distribution of D and lower values suggest that the drainage pattern has become linearized due to the influence of tectonics and surface processes. We use lacunarity analysis using Gliding Box method to see the relative vulnerability as two AOIs can have similar D values. The AOIs with a high lacunarity of drainage pattern are more vulnerable than AOIs with lower lacunarity values. Three AOIs i.e. Vanch and Yazgulem Basin (VYB) in northwestern Pamir, Tirch Mir Fault Zone (TMFZ) in Hindukush region, and Central Badakhshan (CB) with high vulnerability and three sites i.e. Central Pamir, Shiveh Lake Region in Afghanistan and Darvaz Fault Zone with medium vulnerability were identified using fractal dimension. The lacunarity analysis was used to diferentiate between the relative vulnerability of these AOIs. Results from Pyanj river network and adjacent areas show that VYB, TMFZ, and CB have relatively high

  20. A texture-based classification of crackles and squawks using lacunarity.

    Science.gov (United States)

    Hadjileontiadis, Leontios J

    2009-03-01

    An automatic classification method to efficiently discriminate the types of discontinuous breath sounds (DBSs), i.e., fine crackles (FCs), coarse crackles (CC), and squawks (SQ), is presented in this paper. Using the lacunarity of the acquired DBS, the proposed classification method, namely LAC, introduces a texture-based approach that captures the differences in the distribution of FC, CC, and SQ across the breathing cycle, which may lead to more accurate characterization of the pulmonary acoustical changes due to the related pathology. Prior to the lacunarity analysis, wavelet-based denoising of DBS is employed to eliminate effects of the vesicular sound (background noise) to DBS oscillatory pattern. LAC analysis builds its classification power both upon the use of lacunarity at an optimum scale and the approximation of its trajectory across an optimum range of scales using a three-parameter hyperbola model. LAC is applied to 363 DBS corresponding to 25 cases included in four lung sound databases. Results show that LAC efficiently classifies the three DBS categories in the comparison groups of FC-CC, FC-SQ (both with mean accuracy of 100%), CC-SQ (mean accuracy of 99.62%-100%), and FC-CC-SQ (mean accuracy of 99.75%-100%). When compared to other classification tools, LAC seems quite attractive, since, without employing high computational complexity, it results in high classification accuracy. Moreover, LAC introduces a "texture" concept in the analysis of breath sounds, something that strongly relates to the perception of the bioacoustic signals by the physician. Due to its simplicity, LAC could be implemented in a real-time context and be used in clinical medicine as a module of an integrated intelligent patient evaluation system.

  1. Xueshuantong improves cerebral blood perfusion in elderly patients with lacunar infarction

    Institute of Scientific and Technical Information of China (English)

    Qifeng Gui; Yunmei Yang; Shihong Ying; Minming Zhang

    2013-01-01

    A total of 64 patients with acute lacunar infarction were enrolled within 24 hours of onset. The patients received conventional therapy (antiplatelet drugs and hypolipidemic drugs) alone or conventional therapy plus 450 mg Xueshuantong once a day. The main ingredient of the Xueshuantong lyophilized powder used for injection was Panax notoginseng saponins. Assessments were made at admission and at discharge using the National Institutes of Health Stroke Scale, the Activity of Daily Living and the Mini-Mental State Examination. Additionally, the relative cerebral blood flow, relative cerebral blood volume and relative mean transit time in the region of interest were calculated within 24 hours after the onset of lacunar infarction, using dynamic susceptibility contrast magnetic resonance perfusion imaging technology. Patients underwent a follow-up MRI scan after 4 weeks of treatment. There was an improvement in the Activity of Daily Living scores and a greater reduction in the scores on the National Institutes of Health Stroke Scale in the treatment group than in the control group. However, the Mini-Mental State Examination scores showed no significant differences after 4 weeks of treatment. Compared with the control group, the relative cerebral blood flow at discharge had increased and showed a greater improvement in the treatment group. Furthermore, there was a reduction in the relative mean transit time at discharge and the value was lower in the treatment group than in the control group. The experimental findings indicate that Xueshuantong treatment improves neurological deficits in elderly patients with lacunar infarction, and the mechanism may be related to increased cerebral perfusion.

  2. SISTEM VERIFIKASI BIOMETRIKA TELAPAK TANGAN DENGAN METODE DIMENSI FRAKTAL DAN LACUNARITY

    Directory of Open Access Journals (Sweden)

    Ketut Gede Darma Putra

    2009-12-01

    Full Text Available Sistem pengenalan diri secara otomatis dengan telapak tangan merupakan teknologi biometrika yang masih relatif baru. Permasalahan utama dalam sistem pengenalan dengan telapak tangan adalah bagaimana memperoleh ciri telapak tangan tersebut. Penelitian ini memperkenalkan pendekatan baru untuk menghasilkan ciri telapak tangan yaitu dimensi fraktal dan derajat kekosongan fraktal (lacunarity. Skor pencocokan dua telapak tangan dihitung dengan metrika korelasi. Sistem diuji menggunakan sekitar 1250 telapak tangan milik 250 responden. Hasil percobaan menunjukkan sistem mampu menghasilkan tingkat keberhasilan sekitar 98%  atau FAR = 1.9139 %, FRR = 1.9139%, T = 0.2364.

  3. Lacunarity, predictability and predictive instability of the daily pluviometric regime in the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    M. D. Martínez

    2007-01-01

    Full Text Available The complexity of the daily pluviometric regime of the Iberian Peninsula is analysed from the point of view of its lacunarity, predictability and predictive instability. The database consists of daily pluviometric records obtained from 43 rain gauges in Spain and Portugal for the period 1950–1990. Five different series are generated for every rain gauge. The first series is constituted by the consecutive daily amounts. The other four consist of dry spell lengths with respect to daily amount thresholds of 0.1, 1.0, 5.0 and 10.0 mm/day. A dry spell length is defined as the number of consecutive days with rainfall amounts below one of these thresholds. The empirical lacunarity for every rain gauge is well reproduced by two power laws, the exponents varying notably from one gauge to another. The spatial distribution of the lacunarity is characterised by a north to south or southeast gradient, thus suggesting that this parameter can be a useful tool to distinguish between different pluviometric regimes. The predictability of the five series is quantified by means of the rescaled analysis and the interpretation of the Hurst exponent. Its patterns reveal that most part of the Iberian Peninsula shows signs of persistence for the daily rainfall and the dry spell series, although persistence is only clearly manifested in some small domains. The instability of possible predictive algorithms is analysed through the Lyapunov exponents. They are only computed for the series of daily amounts and for dry lengths respect to the threshold level of 0.1 mm/day due to the short number of dry spells for larger threshold levels. The series of daily amounts depict the highest instability along the Mediterranean coast. The series of dry spells show an increasing instability from NE to SW Spain, with a relevant nucleus of high Lyapunov values in the south-western Atlantic coast. As a summary, lacunarity and Hurst and Lyapunov exponents depict a relevant spatial

  4. Capsular warning syndrome and crescendo lacunar strokes after atherosclerotic stenosis of the recurrent artery of Heubner.

    Science.gov (United States)

    Cohen, José E; Rabinstein, Alejandro; Gomori, John M; Leker, Ronen R

    2012-12-01

    The stereotype of repetitive transient cerebral ischemia causing unilateral motor, sensory, or sensorimotor deficits that simultaneously affect the face, arm, and leg, clinically localized to the internal capsule, fits with the description of capsular warning syndrome (CWS). A high proportion of individuals with these symptoms develop subsequent capsular stroke, despite various proposed preventative measures. It has been postulated that the mechanism for such strokes is that of small-vessel single-penetrator disease. We present a patient with repetitive CWS intermingled with crescendo capsular strokes secondary to recurrent artery of Heubner disease. This report causally links CWS-crescendo lacunar strokes and Heubner artery atherosclerotic disease (intracranial branch atheromatous disease).

  5. Changes in the fractal dimension, feret diameter, and lacunarity of mandibular alveolar bone during initial healing of dental implants.

    Science.gov (United States)

    Önem, Erinç; Baksı, B Güniz; Sogur, Elif

    2012-01-01

    To evaluate the combination of fractal dimension (FD), lacunarity, and Feret diameter (FeD) to quantitatively characterize structural changes of mandibular alveolar bone around dental implants during initial healing. Three standard-sized regions of interest (ROIs) (mesial and distal crest and apical area) around implants and three ROIs of the same size in the alveolar bone on the contralateral side were analyzed on digital panoramic images. FD was calculated using the box-counting method, and lacunarity was calculated using the FracLac plugin of Image J software. FeD was measured in the same ROIs. Comparisons of the groups were done with the Dunnett test. Forty-two implants in the posterior mandibles of 21 patients were used for FD measurements. A total of 189 ROIs was segmented into binary images. Mean FD values for mesial, distal, and apical ROIs around implants were 1.26, 1.36, and 1.4, respectively. The mean FD of alveolar bone around premolars/molars was 1.39 for all ROIs. The mean FeD for mesial, distal, and apical ROIs around implants was 7.63, 7.86, and 8.02, respectively, whereas it ranged between 7.88 and 8.13 for premolar teeth. Mean lacunarity values for mesial, distal, and apical ROIs around implants were 0.53, 0.51, and 0.48, respectively. Lacunarity values for ROIs around premolars ranged between 0.45 and 0.50. No significant differences were observed in FD, FeD, or lacunarity measurements between ROIs around implants and around teeth. The satisfactory healing of bone following implant placement may be monitored by calculating FD, lacunarity, and FeD using digital panoramic images. Although preliminary, these values may alert the practitioner to any implants with loss of stability.

  6. Effects of Lacunar Infarctions on Cognitive Impairment in Patients with Cerebral Autosomal-Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy

    Science.gov (United States)

    Choi, Jay Chol; Kang, Sa-Yoon; Kang, Ji-Hoon; Na, Hae Ri; Park, Ji-Kang

    2011-01-01

    Background and Purpose Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited microangiopathy caused by mutations in the Notch3 gene. Although previous studies have shown an association between lacunar infarction and cognitive impairment, the relationship between MRI parameters and cognition remains unclear. In this study we investigated the influence of MRI parameters on cognitive impairment in CADASIL. Methods We applied a prospective protocol to 40 patients. MRI analysis included the normalized volume of white-matter hyperintensities (nWMHs), number of lacunes, and number of cerebral microbleeds. Cognition was assessed with the aid of psychometric tests [Mini-Mental State Examination (MMSE), Alzheimer's Disease Assessment Scale-cognition (ADAS-cog), Trail-Making Test, and Stroop interference (Stroop IF)]. Results A multivariate regression analysis revealed that the total number of lacunes influenced the performance in the MMSE, ADAS-cog, and Stroop IF, while nWMHs had a strong univariate association with ADAS-cog and Stroop IF scores. However, this association disappeared in the multivariate analysis. Conclusions These findings demonstrate that the number of lacunes is the main predictive factor of cognitive impairment in CADASIL. PMID:22259617

  7. Multifractal analysis and lacunarity spectrum of the galaxies of the ninth Sloan Digital Sky Survey (SDSS) data release

    CERN Document Server

    Chacón-Cardona, César A

    2012-01-01

    In this work, we develop a statistical analysis of the large-scale clustering of matter in the Universe from the fractal point of view using galaxies from the Ninth Sloan Digital Sky Survey (SDSS) Data Release (DR9). From the total set of galaxies, a magnitude-limited sample of galaxies with redshifts in the range 0 < z < 0.15 was created. The sample covers the largest completely connected area of the celestial sphere within the catalogue, with limits in right ascension from 120 to 240 degrees and declination from 0 to 60 degrees, which is a region that includes the largest galactic samples that have been studied from the fractal viewpoint to date. The sample contains 164,168 galaxies. Using the sliding-window technique, the multifractal dimension spectrum and its dependence on radial distance are determined. This generalisation of the concept of fractal dimension is used to analyse large-scale clustering of matter in complex systems. Likewise, the lacunarity spectrum, which is a quantity that complemen...

  8. Human Muse Cells Reconstruct Neuronal Circuitry in Subacute Lacunar Stroke Model.

    Science.gov (United States)

    Uchida, Hiroki; Niizuma, Kuniyasu; Kushida, Yoshihiro; Wakao, Shohei; Tominaga, Teiji; Borlongan, Cesario V; Dezawa, Mari

    2017-02-01

    Multilineage-differentiating stress-enduring (muse) cells are endogenous nontumorigenic stem cells with pluripotency harvestable as pluripotent marker SSEA-3(+) cells from the bone marrow from cultured bone marrow-mesenchymal stem cells. After transplantation into neurological disease models, muse cells exert repair effects, but the exact mechanism remains inconclusive. We conducted mechanism-based experiments by transplanting serum/xeno-free cultured-human bone marrow-muse cells into the perilesion brain at 2 weeks after lacunar infarction in immunodeficient mice. Approximately 28% of initially transplanted muse cells remained in the host brain at 8 weeks, spontaneously differentiated into cells expressing NeuN (≈62%), MAP2 (≈30%), and GST-pi (≈12%). Dextran tracing revealed connections between host neurons and muse cells at the lesioned motor cortex and the anterior horn. Muse cells extended neurites through the ipsilateral pyramidal tract, crossed to contralateral side, and reached to the pyramidal tract in the dorsal funiculus of spinal cord. Muse-transplanted stroke mice displayed significant recovery in cylinder tests, which was reverted by the human-selective diphtheria toxin. At 10 months post-transplantation, human-specific Alu sequence was detected only in the brain but not in other organs, with no evidence of tumor formation. Transplantation at the delayed subacute phase showed muse cells differentiated into neural cells, facilitated neural reconstruction, improved functions, and displayed solid safety outcomes over prolonged graft maturation period, indicating their therapeutic potential for lacunar stroke. © 2016 The Authors.

  9. 腔隙性卒中后疲劳与认知障碍和抑郁的相关性:回顾性病例系列研究%Correlation between fatigue and cognitive impairment and depression in patients with lacunar stroke: a retrospective case series study

    Institute of Scientific and Technical Information of China (English)

    王明红; 艾清龙

    2012-01-01

    目的 探讨腔隙性卒中后疲劳与认知障碍和抑郁的相关性.方法 纳入2009年9月至2010年11月期间住院的103例腔隙性卒中患者,采用疲劳量表-14(Fatigue Scale,FS-14)、疲劳严重程度量表(Fatigue Severity Scale,FSS-9)评价卒中后疲劳,简易精神状态检查量表(Mini-Mental State Examinat ion,MMSE)和蒙特利尔认知评估量表(Montreal Cognitive Assessment,MoCA)评价认知功能,抑郁自评量表(Self-Rating Depression Scale,SDS)和汉密尔顿抑郁量表(Hamilton Depression Scale,HAMD)评价抑郁情况.结果 通过不同量表评定,分别有34例(33.01%) (FSS-9)和45例(43.69%)(FS-14)存在疲劳.在根据FSS-9评分确定的34例疲劳患者中,有20例存在认知损害,26例存在抑郁,16例同时存在认知损害和抑郁.Pearson相关分析显示,FS-14评分与MMSE评分(r=-0.307,P =0.002)和MoCA评分(r=-0.457,P=0.000)呈显著负相关,而与SDS评分(r=0.368,P=0.000)和HAMD评分(r=0.526,P=0.000)呈显著正相关;FSS-9评分亦与MMSE评分(r=-0.292,P=0.003)和MoCA评分(r=-0.340,P=0.000)呈显著负相关,而与SDS评分(r=0.403,P=0.000)和HAMD评分(r=0.564,P=0.000)呈显著正相关.结论 腔隙性卒中患者的疲劳、认知损害和抑郁发生率均较高,疲劳与认知损害和抑郁之间存在一定的相关性.%Objective To investigate the correlation between fatigue and cognitive impairment and depression after lacunar stroke.Methods A total of 103 patients with lacunar infarction admitted from September 2009 to November 2010 were enrolled.Post-stroke fatigue was evaluated with the Fatigue Scale (FS-14) and the Fatigue Severity Scale (FSS-9); cognitive function was evaluated with the mini-mental state examination (MMSE) and the Montreal cognitive assessment (MoCA); and depression was evaluated with the self-rating depression scale (SDS) and the Hamilton Depression Rating Scale (HAMD).Results There were 34 patients (33.01%) (FSS-9) and 45 patients (43.69%) (FS-14) had fatigue

  10. A discrimination technique for extensive air showers based on multiscale, lacunarity and neural network analysis

    Science.gov (United States)

    Pagliaro, Antonio; D'Alí Staiti, G.; D'Anna, F.

    2011-03-01

    We present a new method for the identification of extensive air showers initiated by different primaries. The method uses the multiscale concept and is based on the analysis of multifractal behaviour and lacunarity of secondary particle distributions together with a properly designed and trained artificial neural network. In the present work the method is discussed and applied to a set of fully simulated vertical showers, in the experimental framework of ARGO-YBJ, to obtain hadron to gamma primary separation. We show that the presented approach gives very good results, leading, in the 1-10 TeV energy range, to a clear improvement of the discrimination power with respect to the existing figures for extended shower detectors.

  11. Fractal methods and results in cellular morphology--dimensions, lacunarity and multifractals.

    Science.gov (United States)

    Smith, T G; Lange, G D; Marks, W B

    1996-11-01

    This paper discusses the concepts of fractal geometry in a cellular biological context. It defines the concept of the fractal dimension. D, as a measure of complexity and illustrates the two different general ways of quantitatively measuring D by length-related and mass-related methods. Then, these several Ds are compared and contrasted. A goal of the paper is to find methods other than length-related measures that can distinguish between two objects that have the same D but are structurally different. The mass-related D is shown potentially to be such a measure. The concept of lacunarity, L, is defined and methods of measuring L are illustrated. L is also shown to be a potentially distinguishing measure. Finally, the notion of multifracticality is defined and illustrated to exist in certain individual nerve and glial cells.

  12. A discrimination technique for extensive air showers based on multiscale, lacunarity and neural network analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pagliaro, Antonio, E-mail: pagliaro@ifc.inaf.it [Istituto di Astrofisica Spaziale e Fisica Cosmica di Palermo - Istituto Nazionale di Astrofisica, Via Ugo La Malfa 153, 90146 Palermo (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Viale A. Doria 6, 95125 Catania (Italy); D' Ali Staiti, G. [Universita degli Studi di Palermo, Dipartimento di Fisica e Tecnologie Relative, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Viale A. Doria 6, 95125 Catania (Italy); D' Anna, F. [Istituto di Astrofisica Spaziale e Fisica Cosmica di Palermo - Istituto Nazionale di Astrofisica, Via Ugo La Malfa 153, 90146 Palermo (Italy)

    2011-03-15

    We present a new method for the identification of extensive air showers initiated by different primaries. The method uses the multiscale concept and is based on the analysis of multifractal behaviour and lacunarity of secondary particle distributions together with a properly designed and trained artificial neural network. In the present work the method is discussed and applied to a set of fully simulated vertical showers, in the experimental framework of ARGO-YBJ, to obtain hadron to gamma primary separation. We show that the presented approach gives very good results, leading, in the 1-10 TeV energy range, to a clear improvement of the discrimination power with respect to the existing figures for extended shower detectors.

  13. a Multiscale, Lacunarity and Neural Network Method for γ/h Discrimination in Extensive Air Showers

    Science.gov (United States)

    Pagliaro, A.; D'Anna, F.; D'Alí Staiti, G.

    2012-12-01

    This paper presents a new method for the identification of extensive air showers initiated by different primaries. The method uses the multiscale concept and is based on the analysis of multifractal behaviour and lacunarity of secondary particle distributions together with a properly designed and trained artificial neural network. The separation technique is particularly suited for being applied when the topology of the particle distribution in the shower front is as largely detailed as possible. In the present work the method is discussed and applied in the experimental framework of ARGO-YBJ, to obtain hadron to gamma primary separation. We show that the presented approach gives very good results, leading, in the 1 - 10 Tev energy range, to a clear improvement of the discrimination power with respect to the existing figures for extended shower detectors.

  14. Deterioration of pre-existing hemiparesis brought about by subsequent ipsilateral lacunar infarction.

    Science.gov (United States)

    Ago, T; Kitazono, T; Ooboshi, H; Takada, J; Yoshiura, T; Mihara, F; Ibayashi, S; Iida, M

    2003-08-01

    Mechanisms of post-stroke recovery are still poorly understood. Recent evidence suggests that cortical reorganisation in the unaffected hemisphere plays an important role. A 59 year old man developed a small lacunar infarct in the left corona radiata, which then caused marked deterioration in a pre-existing left hemiparesis that had resulted from an earlier right putaminal haemorrhage. Functional magnetic resonance imaging showed that the paretic left hand grip activated the ipsilateral left motor areas, but not the right hemispheric motor areas. This suggests that partial recovery of the left hemiparesis had been brought about by cortical reorganisation of the left hemisphere and intensification of the uncrossed corticospinal tract. The subsequent small infarct may have damaged the uncrossed tract, thereby causing the pre-existing hemiparesis to deteriorate even further.

  15. Carbonic anhydrase levels and internal lacunar CO/sub 2/ concentrations in aquatic macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, C.I.

    1979-01-01

    Carbonic anhydrase levels were examined in a variety of aquatic macrophytes from different habitats. In general, carbonic anhydrase levels increased across the habitat gradient such that activities were low in submersed aquatic macrophytes and high in emergent macrophytes with floating-leaved and free-floating plants exhibiting intermediate activities. Internal lacunar CO/sub 2/ concentrations were analyzed in relation to carbonic anhydrase activities. There was no correlation between these two parameters. Internal CO/sub 2/ concentrations ranged from low to high in submersed macrophytes, but were low in floating-leaved and emergent macrophytes. The observed internal CO/sub 2/ concentrations are discussed in relation to the individual morphologies of the plants and the environments in which they occurred.

  16. Treatment of Lacunar Cerebral Infarction with Huo Xue Tong Luo Tang

    Institute of Scientific and Technical Information of China (English)

    侯安会; 王亚威; 郑一

    2001-01-01

    @@Based on our clinical experience,we formulated Huo Xue Tong Luo Tang(活血通络汤HXTL Decoction),a prescription for treatment of lacunar cerebral infarction.Most of the ingredients are those in the prescriptions of Di Dang Tang(抵当汤)and Gui Gan Long Mu Tang(桂甘龙牡汤)described in the book Treatise of Febrile Diseases(伤寒论)in accordance with the compatible theory of principal,assistant,adjuvant and guiding drugs for improving blood circulation,removing stasis,dispelling endogenous wind and phlegm,inducing resuscitation,removing obstruction in the channels,and balancing the yin and yang.

  17. Cerebrovascular reserve in cerebral small vessel disease patients with lacunar infarction: a transcranial Doppler study%表现为腔隙性梗死的脑小血管病患者的脑血管储备:经颅多普勒研究

    Institute of Scientific and Technical Information of China (English)

    张伟劲; 高庆春; 杨容坤; 陈秀梅; 樊静; 杨继党; 王文君; 张波; 傅贤

    2014-01-01

    目的 探讨表现为腔隙性脑梗死(lacunar infarction,LI)的脑小血管病(cerebral small vessel disease,SVD)患者的脑血管储备(cerebrovascular reserve,CVR)变化.方法 纳入表现为LI的连续SVD患者(SVD组)和影像学检查正常的对照者(对照组).采用(transcranial Doppler,TCD)检测双侧大脑中动脉(middle cerebral artery,MCA)供血区CVR.比较SVD组与对照组人口统计学、临床资料、TCD参数和CVR,并采用多变量logistic回归分析确定CVR与SVD的相关性.结果 共纳入97例表现为LI的SVD患者和40名对照者.SVD组LI分级:1级34例,2级23例,3级40例.40名健康对照者均无LI病灶.SVD组高血压(58.8%对27.5%;x2=3.315,P=0.001)和男性患者(76.3%对50.0% 2=3.004,P=0.003)的构成比以及年龄[(64.5±10.0)岁对(59.5±8.0)岁;t=2.667,P=0.008]和体质指数(body mass index,BMI)[(24.47±3.16)kg/m2对(21.52 ±2.15) kg/m2;=5.409,P<0.001]均显著性高于对照组.MCA平均血流速度在正常范围,但SVD组右侧MCA搏动指数(pulsatility index,PI)显著性高于对照组(0.90±0.15对0.83±0.11;=2.286,P=0.024),SVD组左侧[(4.56±1.12)%/mm Hg对(7.42±0.62) %/mm Hg,1 mmHg=0.133kPa;t 18.93,P<0.000]和右侧[(4.62±1.00)%/mmHg对(7.43±0.59)%/mm Hg;t =20.45,P<0.001] CVR显著性低于对照组.多变量logistic回归分析显示,高血压[优势比(odds ratio,OR)3.757,95%可信区间(confidence interval,CI)1.683 ~8.388;P <0.001]、年龄较大(OR1.061,95% CI1.016~1.109;P=0.007)和BMI较高(OR1.428,1.224 ~ 1.667;P<0.001)为SVD的独立危险因素,男性(OR0.311,0.143 ~0.676;P =0.003)以及左侧(OR 0.025,95% CI0.005 ~0.116;P<0.001)和右侧(OR0.001,95% CI0.000~0.049;P<0.001)CVR较高为SVD的独立保护性因素.结论 表现为LI的SVD患者脑血流动力学主要表现为CVR降低,存在高血压、年龄较大、BMI较高是SVD的独立危险因素,丽男性和CVR较高是SVD的独立保护因素.%Objective To investigate the changes of

  18. The Quantitative Criteria Based on the Fractal Dimensions, Entropy, and Lacunarity for the Spatial Distribution of Cancer Cell Nuclei Enable Identification of Low or High Aggressive Prostate Carcinomas

    National Research Council Canada - National Science Library

    Waliszewski, Przemyslaw

    2016-01-01

    ...) and the local connected fractal dimension (LCFD), Shannon entropy H and lacunarity λ were measured using computer algorithms in digitalized images of both the reference set (n = 60) and the test set (n = 208...

  19. 腔隙性脑梗死在原发性高血压患者危险分层中的意义%The significance of lacunar infarction in the risk stratification of essential hyertension

    Institute of Scientific and Technical Information of China (English)

    姚保明

    2011-01-01

    Objective: To study the significance of lacunar infarction in the risk stratification of essential hypertension. Methods: 214 patients with essential hypertension were divided into CLI group (lacunar infarction group), ACC group (related clinical conditions group) and TOD group (target organ damage group), then the damage degree of heart, renal and fundus of the three groups were compared. Results: The damage degree of heart, renal and fundus between CLI group and ACC group showed significant difference (ρ<0.01), the damage degree of heart, renal and fundus between CLI group and TOD group showed no significant difference (ρ>0.05). Conclusion: The lacunar infarction is index of risk stratification of essential hypertension, it shows the damage of heart, renal and fundus, the degree is similar to TOD, and should be the classification of TOD.%目的:探讨腔隙性脑梗死在原发性高血压危险分层中的意义.方法:241例原发性高血压患者被分为CLI组(腔隙性脑梗死组)、ACC组(相关临床情况组)和TOD组(靶器官损害组),比较三组间心、肾、眼底损害程度.结果:CLI组与ACC组间的心、肾及眼底损害程度比较,差异有统计学意义(P<0.01),CLI组与TOD组比较,差异无统计学意义(P>0.05).结论:腔隙性脑梗死作为原发性高血压危险分层中的指标,提示患者出现心、肾、眼底损害,其程度与TOD组相似,宜归为TOD组.

  20. Maximum entropy, fractal dimension and lacunarity in quantification of cellular rejection in myocardial biopsy of patients submitted to heart transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Neves, L A [Universidade Estadual Paulista, IGCE, DEMAC, Rio Claro, SP (Brazil); Oliveira, F R; Peres, F A [Faculdade de Tecnologia de Sao Jose do Rio Preto, Sao Jose do Rio Preto, SP (Brazil); Moreira, R D; Moriel, A R; De Godoy, M F [Faculdade de Medicina de Sao Jose do Rio Preto, FAMERP, Sao Jose do Rio Preto, SP (Brazil); Murta Junior, L O, E-mail: laneves@rc.unesp.br [Universidade de Sao Paulo, FFCLRP, Depto Computacao e Matematica, Ribeirao Preto (Brazil)

    2011-03-01

    This paper presents a method for the quantification of cellular rejection in endomyocardial biopsies of patients submitted to heart transplant. The model is based on automatic multilevel thresholding, which employs histogram quantification techniques, histogram slope percentage analysis and the calculation of maximum entropy. The structures were quantified with the aid of the multi-scale fractal dimension and lacunarity for the identification of behavior patterns in myocardial cellular rejection in order to determine the most adequate treatment for each case.

  1. Maximum entropy, fractal dimension and lacunarity in quantification of cellular rejection in myocardial biopsy of patients submitted to heart transplantation

    Science.gov (United States)

    Neves, L. A.; Oliveira, F. R.; Peres, F. A.; Moreira, R. D.; Moriel, A. R.; de Godoy, M. F.; Murta Junior, L. O.

    2011-03-01

    This paper presents a method for the quantification of cellular rejection in endomyocardial biopsies of patients submitted to heart transplant. The model is based on automatic multilevel thresholding, which employs histogram quantification techniques, histogram slope percentage analysis and the calculation of maximum entropy. The structures were quantified with the aid of the multi-scale fractal dimension and lacunarity for the identification of behavior patterns in myocardial cellular rejection in order to determine the most adequate treatment for each case.

  2. Spatial dispersion and clustering of soil structure through lacunarity of X-ray CT images of soil macropore volumes

    Science.gov (United States)

    San José Martínez, Fernando; Caniego, Javier; García-Gutiérrez, Carlos

    2016-04-01

    Lacunarity can be seen as a scale dependent measure of heterogeneity or texture ―in terms of image analysis― that was first introduced to quantify different patterns of dispersion and clustering that display geometrical objects with the same fractal dimension. Notwithstanding, lacunarity functions have been revealed as means to measure the deviation of object's geometrical structure from translational invariance beyond self-similarity and fractal geometry. In this work, we will explore how lacunarity quantifies different patterns of dispersion and clustering of different geometrical structures of soil macropore volumes imaged by X-ray computed tomography. Samples extracted from columns were collected at the experimental farm "Finca La Grajera" in La Rioja (Spain), property of La Rioja Regional Government (northern Spain). The vineyard selected was established in 1996. During the 1996 to 2004 period, the soil management was conventional tillage. Before the vineyard was established in 1996, a pasture-legume-cereal rotation was used. In 2004 an experiment was established with different types of soil cover management in between. On December 2010 columns were extracted vertically by percussion drilling between rows of the vineyard.

  3. Fractal lacunarity of trabecular bone and magnetic resonance imaging: New perspectives for osteoporotic fracture risk assessment.

    Science.gov (United States)

    Zaia, Annamaria

    2015-03-18

    fractal analysis as a promising approach to quantify morpho-functional changes in both aging and pathology. In this particular context, fractal lacunarity seems to be the proper tool to characterize TBA texture as it is able to describe both discontinuity of bone network and sizes of bone marrow spaces, whose changes are an index of bone fracture risk. In this paper, an original method of MRI texture analysis, based on TBA fractal lacunarity is described and discussed in the light of new perspectives for early diagnosis of osteoporotic fractures.

  4. Enhanced Classification of Interstitial Lung Disease Patterns in HRCT Images Using Differential Lacunarity

    Directory of Open Access Journals (Sweden)

    Verónica Vasconcelos

    2015-01-01

    Full Text Available The analysis and interpretation of high-resolution computed tomography (HRCT images of the chest in the presence of interstitial lung disease (ILD is a time-consuming task which requires experience. In this paper, a computer-aided diagnosis (CAD scheme is proposed to assist radiologists in the differentiation of lung patterns associated with ILD and healthy lung parenchyma. Regions of interest were described by a set of texture attributes extracted using differential lacunarity (DLac and classical methods of statistical texture analysis. The proposed strategy to compute DLac allowed a multiscale texture analysis, while maintaining sensitivity to small details. Support Vector Machines were employed to distinguish between lung patterns. Training and model selection were performed over a stratified 10-fold cross-validation (CV. Dimensional reduction was made based on stepwise regression (F-test, p value < 0.01 during CV. An accuracy of 95.8 ± 2.2% in the differentiation of normal lung pattern from ILD patterns and an overall accuracy of 94.5 ± 2.1% in a multiclass scenario revealed the potential of the proposed CAD in clinical practice. Experimental results showed that the performance of the CAD was improved by combining multiscale DLac with classical statistical texture analysis.

  5. Enhanced Classification of Interstitial Lung Disease Patterns in HRCT Images Using Differential Lacunarity.

    Science.gov (United States)

    Vasconcelos, Verónica; Barroso, João; Marques, Luis; Silva, José Silvestre

    2015-01-01

    The analysis and interpretation of high-resolution computed tomography (HRCT) images of the chest in the presence of interstitial lung disease (ILD) is a time-consuming task which requires experience. In this paper, a computer-aided diagnosis (CAD) scheme is proposed to assist radiologists in the differentiation of lung patterns associated with ILD and healthy lung parenchyma. Regions of interest were described by a set of texture attributes extracted using differential lacunarity (DLac) and classical methods of statistical texture analysis. The proposed strategy to compute DLac allowed a multiscale texture analysis, while maintaining sensitivity to small details. Support Vector Machines were employed to distinguish between lung patterns. Training and model selection were performed over a stratified 10-fold cross-validation (CV). Dimensional reduction was made based on stepwise regression (F-test, p value < 0.01) during CV. An accuracy of 95.8 ± 2.2% in the differentiation of normal lung pattern from ILD patterns and an overall accuracy of 94.5 ± 2.1% in a multiclass scenario revealed the potential of the proposed CAD in clinical practice. Experimental results showed that the performance of the CAD was improved by combining multiscale DLac with classical statistical texture analysis.

  6. The mechanism of ipsilateral ataxia in lacunar hemiparesis: SPECT perfusion imaging.

    Science.gov (United States)

    Yamamoto, Ryoo; Johkura, Ken; Nakae, Yoshiharu; Tanaka, Fumiaki

    2015-01-01

    Although ataxic hemiparesis is a common lacunar syndrome, the precise mechanism underlying hemiataxia is not clear. We attempted to identify ataxia-related, cerebral blood flow changes in patients presenting with ataxic hemiparesis after acute capsular infarct. We used 99mTc-ECD brain perfusion single-photon emission computed tomography to evaluate regional cerebral blood flow in 12 patients with ataxic hemiparesis caused by capsular infarct, and we compared the regional blood flow of these patients with that of 11 patients with pure motor hemiparesis caused by similar lesions. The ipsilateral red nucleus blood flow was significantly decreased in the ataxic hemiparesis patients, whereas the ipsilateral red nucleus blood flow was increased in the pure motor hemiparesis patients. Crossed cerebellar diaschisis (decreased contralateral cerebellar blood flow) was seen in ataxic hemiparesis patients; similarly, it was seen in pure motor hemiparesis patients. Our findings suggest that ataxia in hemiparetic patients with capsular infarct can be caused by ipsilateral red nucleus dysfunction secondary to cortico-rubral pathway disruption at the internal capsule.

  7. Association and differences in genetic polymorphisms in PCSK9 gene in subjects with lacunar infarction in the Han and Uygur populations of Xinjiang Uygur Autonomous Region of China

    Directory of Open Access Journals (Sweden)

    Deng-feng Han

    2017-01-01

    Full Text Available Polymorphisms in the proprotein convertase subtilisin/kexin type 9 (PCSK9 gene are associated with severe hypercholesterolemia and stroke. Here, we investigated the relationship between single nucleotide polymorphisms in PCSK9 and stroke in 237 patients with lacunar infarction in the Uygur and Han populations in Xinjiang Uygur Autonomous Region of China. Using the SNaPshot single-base terminal extension method, four PCSK9 gene polymorphisms were analyzed. We found a significantly strong relationship between the PCSK9 rs17111503 (G > A polymorphism and increased susceptibility to lacunar infarction by variant homozygote comparison, and using the dominant and recessive models in the Han population but not in the Uygur population. Low triglyceride levels were found in AA carriers (rs17111503, G > A in the Han population but not in the Uygur population. Association analysis revealed that the rs17111503 (G > A polymorphism was not significantly associated with smoking, alcohol drinking, history of hypertension or diabetes in the Han or Uygur lacunar infarction patients. rs11583680, rs483462 and rs505151 were not associated with risk of lacunar infarction in the Han or Uygur populations. Our findings suggest that the PCSK9 rs17111503 (G > A polymorphism is associated with susceptibility to lacunar infarction in the Han population but not in the Uygur population.

  8. Deep Cerebral Microbleeds and Renal Dysfunction in Patients with Acute Lacunar Infarcts.

    Science.gov (United States)

    Saji, Naoki; Kimura, Kazumi; Yagita, Yoshiki; Uemura, Junichi; Aoki, Junya; Sato, Takahiro; Sakurai, Takashi

    2015-11-01

    Cerebral small-vessel disease (SVD) is associated with renal dysfunction such as chronic kidney disease. Although cerebral microbleeds (CMBs) are common in patients with acute lacunar infarcts (ALI), the association between renal dysfunction and CMBs in such patients remains unclear. Between April 2007 and March 2013, we evaluated consecutive first-ever ALI patients, who were admitted to our hospital within 24 hours of stroke onset. CMBs were defined as focal areas of signal loss in brain parenchyma less than 5 mm on T2(∗)-weighted gradient-echo imaging. Renal dysfunction was defined as an estimated glomerular filtration rate less than 60 mL/minute/1.73 m(2) on admission. Correlations between renal dysfunction and the presence (model 1) and location of CMBs (model 2; any deep or infratentorial CMBs) were determined by multivariable logistic regression analyses. Among 152 patients (33.6% men; mean age, 67.6 years), 53 had CMBs. Patients with CMBs were older (69.9 versus 66.3 years, P = .03) and had a higher frequency of white matter hyperintensity (WMH; 62.3% versus 25.3%, P CMBs. On multivariable analyses, renal dysfunction (odds ratio, 95% confidence interval; model 1: 2.38, 1.02-5.66; model 2: 2.78, 1.16-6.81), WMH (3.87, 1.76-8.80; 3.72, 1.64-8.71), SLI (3.85, 1.71-9.14; 4.20, 1.77-10.8), and diabetes mellitus (.26, .09-.63; .24, .08-.63) were independently associated with CMBs. In patients with ALI, renal dysfunction was positively associated with CMBs independent of cerebral SVD. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  9. Fractal signature and lacunarity in the measurement of the texture of trabecular bone in clinical CT images.

    Science.gov (United States)

    Dougherty, G; Henebry, G M

    2001-07-01

    Fractal analysis is a method of characterizing complex shapes such as the trabecular structure of bone. Numerous algorithms for estimating fractal dimension have been described, but the Fourier power spectrum method is particularly applicable to self-affine fractals, and facilitates corrections for the effects of noise and blurring in an image. We found that it provided accurate estimates of fractal dimension for synthesized fractal images. For natural texture images fractality is limited to a range of scales, and the fractal dimension as a function of spatial frequency presents as a fractal signature. We found that the fractal signature was more successful at discriminating between these textures than either the global fractal dimension or other metrics such as the mean width and root-mean-square width of the spectral density plots. Different natural textures were also readily distinguishable using lacunarity plots, which explicitly characterize the average size and spatial organization of structural sub-units within an image. The fractal signatures of small regions of interest (32x32 pixels), computed in the frequency domain after corrections for imaging system noise and MTF, were able to characterize the texture of vertebral trabecular bone in CT images. Even small differences in texture due to acquisition slice thickness resulted in measurably different fractal signatures. These differences were also readily apparent in lacunarity plots, which indicated that a slice thickness of 1 mm or less is necessary if essential architectural information is not to be lost. Since lacunarity measures gap size and is not predicated on fractality, it may be particularly useful for characterizing the texture of trabecular bone.

  10. The use of fractal dimension and lacunarity in the characterization of mast cell degranulation in rainbow trout (Onchorhynchus mykiss).

    Science.gov (United States)

    Manera, M; Dezfuli, B S; Borreca, C; Giari, L

    2014-11-01

    Fractal analysis is a reliable method for describing, summarizing object complexity and heterogeneity and has been widely used in biology and medicine to deal with scale, size and shape management problems. The aim of present survey was to use fractal analysis as a complexity measure to characterize mast cells (MCs) degranulation in a rainbow trout ex vivo model (isolated organ bath). Compound 48/80, a condensation product of N-methyl-p-methoxyphenethylamine with formaldehyde, was adopted as MCs degranulation agent in trout intestinal strips. Fractal dimension (D), as a measure of complexity, 'roughness' and lacunarity (λ), as a measure of rotational and translational invariance, heterogeneity, in other words, of the texture, were compared in MCs images taken from intestinal strips before and after compound 48/80 addition to evaluate if and how they were affected by degranulation. Such measures were also adopted to evaluate their discrimination efficacy between compound 48/80 degranulated group and not degranulated group and the results were compared with previously reported data obtained with conventional texture analysis (image histogram, run-length matrix, co-occurrence matrix, autoregressive model, wavelet transform) on the same experimental material. Outlines, skeletons and original greyscale images were fractal analysed to evaluate possible significant differences in the measures values according to the analysed feature. In particular, and considering outline and skeleton as analysed features, fractal dimensions from compound 48/80 treated intestinal strips were significantly higher than the corresponding untreated ones (paired t and Wilcoxon test, p lacunarity values were significantly lower (paired Wilcoxon test, p lacunarity (image heterogeneity) reduction is consistent with the biological informative content decrease, due to granule content depletion. In spite of the significant differences in fractal dimension and lacunarity values registered according

  11. Histomorphometric, fractal and lacunarity comparative analysis of sheep (Ovis aries), goat (Capra hircus) and roe deer (Capreolus capreolus) compact bone samples.

    Science.gov (United States)

    Gudea, A I; Stefan, A C

    2013-08-01

    Quantitative and qualitative studies dealing with histomorphometry of the bone tissue play a new role in modern legal medicine/forensic medicine and archaeozoology nowadays. This study deals with the differences found in case of humerus and metapodial bones of recent sheep (Ovis aries), goat (Capra hircus) and roedeer (Capreolus capreolus) specimens, both from a qualitative point of view, but mainly from a quantitative perspective. A novel perspective given by the fractal analysis performed on the digital histological images is approached. This study shows that the qualitative assessment may not be a reliable one due to the close resemblance of the structures. From the quantitative perspective (several measurements performed on osteonal units and statistical processing of data),some of the elements measured show significant differences among 3 species(the primary osteonal diameter, etc.). The fractal analysis and the lacunarity of the images show a great deal of potential, proving that this type of analysis can be of great help in the separation of the material from this perspective.

  12. Cerebral Microbleeds and Lacunar Infarcts Are Associated with Walking Speed Independent of Cognitive Performance in Middle-Aged to Older Adults.

    Science.gov (United States)

    Stijntjes, Marjon; de Craen, Anton J M; van der Grond, Jeroen; Meskers, Carel G M; Slagboom, P Eline; Maier, Andrea B

    2016-01-01

    The positive relationship between cognitive and physical performance has been widely established. The influence of brain structure on both domains has been shown as well. We studied whether the relationship between brain structure and physical performance is independent of cognitive performance. This was a cross-sectional analysis of 297 middle-aged to older adults (mean age ± SD 65.4 ± 6.8 years). Memory function, executive function and physical performance measured by the Tandem Stance Test, Chair Stand Test, 4-meter walk and 25-meter walk were assessed. Magnetic resonance imaging was available in 237 participants and used to determine the (sub)cortical gray matter, white matter, hippocampal and basal ganglia volumes and the presence of cerebral small-vessel disease, i.e. white matter hyperintensities, cerebral microbleeds (CMBs) and lacunar infarcts (LIs). Regression analysis was used adjusting for age, gender, education and whole-brain volume. A Bonferroni correction was applied considering p values cognitive performance. The presence of CMBs and LIs was associated with a slower 25-meter walking speed (p cognitive performance. In middle-aged to older adults, CMBs and LIs are associated with walking speed independent of cognitive performance. This emphasizes the clinical relevance of identifying each of the possible underlying mechanisms of physical performance, which is required for the development of timely and targeted therapies. © 2016 The Author(s) Published by S. Karger AG, Basel.

  13. The correlation of the thalamic lesions on MRI with cerebral cortical blood flow in patients with lacunar infarction

    Energy Technology Data Exchange (ETDEWEB)

    Nabatame, Hidehiko; Nakamura, Kazuo; Matsuda, Minoru; Fujimoto, Naoki [Shiga Medical Center, Moriyama (Japan); Fukuyama, Hidenao

    1995-07-01

    We performed MRI and measured cerebral blood flow (CBF) using {sup 123}I-IMP SPECT microsphere model in twenty three right-handed patients with lacunar infarction. Twelve of 23 patients showed chronic deterioration of dysarthria and gait disturbance. The mental function of the patients was evaluated by the Mini-Mental State (MMS) examination. The area of high intensity on T2-weighted images was quantitatively analyzed in the cerebral white matter (WM), lenticular nucleus (LN) and thalamus (THA). The score of MMS was positively correlated with the local CBF in the bilateral frontal, parietal, temporal and occipital cortices (p<0.05). Also, the area of high intensity in the left THA showed a significant negative correlation with local CBF of the bilateral frontal, parietal, temporal and occipital cortices (p<0.001). The high intensity areas of the bilateral LN, right WM and right THA had a significant but weaker negative correlation with local CBF of some cortices. These findings suggest that thalamic lesions on the dominant side play an important role in the reduction of cortical blood flow and the deterioration of mental functions in patients with lacunar infarction. (author).

  14. Hypermineralization and High Osteocyte Lacunar Density in Osteogenesis Imperfecta Type V Bone Indicate Exuberant Primary Bone Formation.

    Science.gov (United States)

    Blouin, Stéphane; Fratzl-Zelman, Nadja; Glorieux, Francis H; Roschger, Paul; Klaushofer, Klaus; Marini, Joan C; Rauch, Frank

    2017-09-01

    In contrast to "classical" forms of osteogenesis imperfecta (OI) types I to IV, caused by a mutation in COL1A1/A2, OI type V is due to a gain-of-function mutation in the IFITM5 gene, encoding the interferon-induced transmembrane protein 5, or bone-restricted interferon-inducible transmembrane (IFITM)-like protein (BRIL). Its phenotype distinctly differs from OI types I to IV by absence of blue sclerae and dentinogenesis imperfecta, by the occurrence of ossification disorders such as hyperplastic callus and forearm interosseous membrane ossification. Little is known about the impact of the mutation on bone tissue/material level in untreated and bisphosphonate-treated patients. Therefore, investigations of transiliac bone biopsy samples from a cohort of OI type V children (n = 15, 8.7 ± 4 years old) untreated at baseline and a subset (n = 8) after pamidronate treatment (2.6 years in average) were performed. Quantitative backscattered electron imaging (qBEI) was used to determine bone mineralization density distribution (BMDD) as well as osteocyte lacunar density. The BMDD of type V OI bone was distinctly shifted toward a higher degree of mineralization. The most frequently occurring calcium concentration (CaPeak) in cortical (Ct) and cancellous (Cn) bone was markedly increased (+11.5%, +10.4%, respectively, p V Ct and Cn bone (+171%, p V patients is hypermineralized, similar to other forms of OI. The elevated osteocyte lacunar density in connection with lack of regular bone lamellation points to an exuberant primary bone formation and an alteration of the bone remodeling process in OI type V. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.

  15. A comparison of the texture of computed tomography and projection radiography images of vertebral trabecular bone using fractal signature and lacunarity.

    Science.gov (United States)

    Dougherty, G

    2001-06-01

    The structural integrity of trabecular bone is an important factor characterizing the biomechanical strength of the vertebra, and is determined by the connectivity of the bone network and the trabeculation pattern. These can be assessed using texture measures such as the fractal signature and lacunarity from a high resolution projection radiograph. Using central sections of lumbar vertebrae we compared the results obtained from high-resolution transverse projection images with those obtained from spatially registered low-resolution images from a conventional clinical CT scanner to determine whether clinical CT data can provide useful structural information. Provided the power spectra of the CT images are corrected for image system blurring, the resulting fractal signature is similar for both modalities. Although the CT images are blurred relative to the projection images, with a consequent reduction in lacunarity, the estimated trabecular separation obtained from the lacunarity plots is similar for both modalities. This suggests that these texture measures contain essential information on trabecular microarchitecture, which is present even in low resolution CT images. Such quantitative texture measurements from CT or MRI images are potentially useful in monitoring bone strength and predicting future fracture risk.

  16. The Quantitative Criteria Based on the Fractal Dimensions, Entropy and Lacunarity for the Spatial Distribution of Cancer Cell Nuclei Enable Identification of Low or High Aggressive Prostate Carcinomas

    Directory of Open Access Journals (Sweden)

    Przemyslaw eWaliszewski

    2016-02-01

    Full Text Available Background: Tumor grading, PSA concentration, and stage determine a risk of prostate cancer patients with accuracy of about 70%. An approach based on the fractal geometrical model was proposed to eliminate subjectivity from the evaluation of tumor aggressiveness and to improve the prediction. This study was undertaken to validate classes of equivalence for the spatial distribution of cancer cell nuclei in a larger, independent set of prostate carcinomas.Methods: The global fractal capacity D0, information D1 and correlation D2 dimension, the local fractal dimension (LFD and the local connected fractal dimension (LCFD, Shannon entropy H and lacunarity were measured using computer algorithms in digitalized images of both the reference set (n = 60 and the test set (n = 208 of prostate carcinomas.Results: Prostate carcinomas were re-stratified into seven classes of equivalence. The cut-off D0 values 1.5450, 1.5820, 1.6270, 1.6490, 1.6980, 1.7640 defined the classes from C1 to C7, respectively. The other measures but the D1 failed to define the same classes of equivalence. The pairs (D0, LFD, (D0, H, (D0, , (D1, LFD, (D1, H, (D1,  characterized the spatial distribution of cancer cell nuclei in each class. The co-application of those measures enabled the subordination of prostate carcinomas to one out of three clusters associated with different tumor aggressiveness. For D0 0.8, the class C1 or C2 contains low complexity low aggressive carcinomas exclusively. For D0 > 1.6980, LFD > 1.7644, LCFD > 1.7051, H > 0.9, and < 0.7, the class C6 or C7 contains high complexity high aggressive carcinomas. Conclusions: The cut-off D0 values defining the classes of equivalence were validated in this study. The cluster analysis suggested that the number of the subjective Gleason grades and the number of the objective classes of equivalence could be decreased from seven to three without a loss of clinically relevant information. Two novel quantitative

  17. The Quantitative Criteria Based on the Fractal Dimensions, Entropy, and Lacunarity for the Spatial Distribution of Cancer Cell Nuclei Enable Identification of Low or High Aggressive Prostate Carcinomas.

    Science.gov (United States)

    Waliszewski, Przemyslaw

    2016-01-01

    Tumor grading, PSA concentration, and stage determine a risk of prostate cancer patients with accuracy of about 70%. An approach based on the fractal geometrical model was proposed to eliminate subjectivity from the evaluation of tumor aggressiveness and to improve the prediction. This study was undertaken to validate classes of equivalence for the spatial distribution of cancer cell nuclei in a larger, independent set of prostate carcinomas. The global fractal capacity D 0, information D 1 and correlation D 2 dimension, the local fractal dimension (LFD) and the local connected fractal dimension (LCFD), Shannon entropy H and lacunarity λ were measured using computer algorithms in digitalized images of both the reference set (n = 60) and the test set (n = 208) of prostate carcinomas. Prostate carcinomas were re-stratified into seven classes of equivalence. The cut-off D 0-values 1.5450, 1.5820, 1.6270, 1.6490, 1.6980, 1.7640 defined the classes from C1 to C7, respectively. The other measures but the D 1 failed to define the same classes of equivalence. The pairs (D 0, LFD), (D 0, H), (D 0, λ), (D 1, LFD), (D 1, H), (D 1, λ) characterized the spatial distribution of cancer cell nuclei in each class. The co-application of those measures enabled the subordination of prostate carcinomas to one out of three clusters associated with different tumor aggressiveness. For D 0 1.5, H 0.8, the class C1 or C2 contains low complexity low aggressive carcinomas exclusively. For D 0 > 1.6980, LFD > 1.7644, LCFD > 1.7051, H > 0.9, and λ < 0.7, the class C6 or C7 contains high complexity high aggressive carcinomas. The cut-off D 0-values defining the classes of equivalence were validated in this study. The cluster analysis suggested that the number of the subjective Gleason grades and the number of the objective classes of equivalence could be decreased from seven to three without a loss of clinically relevant information. Two novel quantitative criteria based on the complexity

  18. MRI and CT for diagnosis of early lacunar infarction%MRI和CT两种不同影像学检查方法对早期腔隙性脑梗塞的临床诊断价值分析

    Institute of Scientific and Technical Information of China (English)

    张艳平

    2016-01-01

    Objective To investigate the clinical diagnostic value of MRI and CT in early lacunar infarction.Methods Clinical data of 326 cases of early lacunar infarction underwent CT,MRI examination in our hospital from March 2012 to June 2015 was retrospectively analyzed.Analyzed the diagnosis of all patients by CT and MRI,compared lesion detection rate of two methods,satisfaction on examination time and cost.Results The study reviewed 326 cases of early lacunar infarction,excluding 7 cases on whose image views of experts were not consistent.In other 319 cases,268 lesions were found after plain CT scan,with lesion size about 0.5-1 cm;472 lesions were found after MRI examination,whose size were mostly less than 0.5 cm;there was statistically significant difference between two examination methods (P<0.05).In 319 cases,231 cases were quite satisfied with MRI,with the satisfaction degree of 72.4%;235 cases were quite satisfied with CT,with the satisfaction degree of 73.7%;there was no statistically significant difference between two examination methods (P>0.05).Conclusions In clinical diagnosis of early lacunar infarction patients,MRI is more sensitive than CT,without radiation,with a higher safety factor.But the satisfaction degree on CT of 319 cases is slightly higher than that on MRI,in addition to MRI taking more than ten minutes,some heart and lung failure patients can not tolerate MRI,the main factor is that cost of MRI is much higher than that of CT,showing low-cost and high detection rate account for a large proportion in the heart of patients.Enhancing the sensitivity of CT and reducing the cost of MRI are the next focus of our work.%目的 探讨MRI和CT两种不同影像学对早期腔隙性脑梗塞的临床诊断价值.方法 回顾分析我院2012年3月至2015年6月收治已确诊早期腔隙性脑梗塞并均已经行CT、MRI检查的患者共326例,分析所有患者CT及MRI的诊断结果,对比两种检查方式的病灶检出率,比较患者

  19. Coherence, space non-locality and lacunarity in a cascade model of turbulence

    CERN Document Server

    Olla, P; Olla, Piero; Paradisi, Paolo

    1998-01-01

    We use multiscale-multispace correlations and Fourier transform techniques, to study some intermittent random field properties, which escape analysis by structure function scaling. These properties are parametrized in terms of a set of scale ratios, giving the typical interaction distances in space and scale of the random field fluctuations, and the characteristic lengths over which these fluctuations act coherently to generate intermittency. The relevance of these techniques in turbulence theory is discussed.

  20. Effect of observational holes and borders on lacunarity and fractality measurements in a galaxy catalogue

    CERN Document Server

    García-Farieta, Jorge E

    2016-01-01

    Cosmological observations reveal that the Universe contains a hierarchy of galaxy clustering with a transition to homogeneity on large scales according to the $\\Lambda$CDM model. Some observational estimates suggest that the Universe behaves as a multifractal object, where galactic clustering is based on generalisation of the dimension in metric spaces. From this point of view, we study the spatial distribution of points by simulating galaxies on large scales in the Universe with samples from the Sloan Digital Sky Survey (SDSS), including observational holes in the masks. We build homogeneous samples following the radial selection function using the "shuffle" method for a main sample of $3,273,548$ points limited to the redshift range $0.0020$ and percentages of holes near $40\\%$, $r_H$ is displaced on scales on the order of $120~Mpc/h$. Hole percentages between $10\\%$ and $30\\%$ show an $r_H$ of $70-90~Mpc/h$, and for percentages below $10\\%$, $r_H$ decreases to become equal to the $r_H$ value of the SDSS-BO...

  1. Free radical scavenger, edaravone, reduces the lesion size of lacunar infarction in human brain ischemic stroke

    Science.gov (United States)

    2011-01-01

    Background Although free radicals have been reported to play a role in the expansion of ischemic brain lesions, the effect of free radical scavengers is still under debate. In this study, the temporal profile of ischemic stroke lesion sizes was assessed for more than one year to evaluate the effect of edaravone which might reduce ischemic damage. Methods We sequentially enrolled acute ischemic stroke patients, who admitted between April 2003 and March 2004, into the edaravone(-) group (n = 83) and, who admitted between April 2004 and March 2005, into the edaravone(+) group (n = 93). Because, edaravone has been used as the standard treatment after April 2004 in our hospital. To assess the temporal profile of the stroke lesion size, the ratio of the area [T2-weighted magnetic resonance images (T2WI)/iffusion-weighted magnetic resonance images (DWI)] were calculated. Observations on T2WI were continued beyond one year, and observational times were classified into subacute (1-2 months after the onset), early chronic (3-6 month), late chronic (7-12 months) and old (≥13 months) stages. Neurological deficits were assessed by the National Institutes of Health Stroke Scale upon admission and at discharge and by the modified Rankin Scale at 1 year following stroke onset. Results Stroke lesion size was significantly attenuated in the edaravone(+) group compared with the edaravone(-) group in the period of early and late chronic observational stages. However, this reduction in lesion size was significant within a year and only for the small-vessel occlusion stroke patients treated with edaravone. Moreover, patients with small-vessel occlusion strokes that were treated with edaravone showed significant neurological improvement during their hospital stay, although there were no significant differences in outcome one year after the stroke. Conclusion Edaravone treatment reduced the volume of the infarct and improved neurological deficits during the subacute period, especially

  2. 老年人执行功能障碍与腔隙性脑梗死的关系%Relations between Executive Dysfunction and Lacunar Infarction in Senior Patients

    Institute of Scientific and Technical Information of China (English)

    王玲; 吴楠; 王健; 王中平; 焦清海

    2011-01-01

    目的 探讨老年腔隙性脑梗死患者执行功能损害状况以及二者关系.方法 对39例老年志愿者进行头颅MRI、CT检查,按照有无腔隙性脑梗死分为梗死组14例和无梗死组25例,运用神经心理学测试方法评估两组执行功能损害状况,分析腔隙性脑梗死灶的数量和执行功能损害的关系.结果 腔隙性梗死组执行功能测验中额叶功能评定量表(FAB)(8.73±3.47)分,执行性画钟作业(CLOX)(8.73±3.47)分,词语流畅性测验(RVR)(29.75±12.17)分,均低于无梗死组的(11.66±2.37)分、(12.15±2.36)分及(38.24±8.93)分(P<0.05).单因素回归分析显示,腔隙性脑梗死灶的数目和3项执行功能测验均呈明显的负性关系,FAB评分r2=0.9420,P<0.05;CLOX评分r2=0.8715,P<0.05;RVR评分r2=0.9231,P<0.05.结论 老年腔隙性脑梗死会对执行功能产生影响,腔隙性脑梗死灶的数量与执行功能的下降显著相关.%Objective To investigate the situation of executive function in patients with lacunar infarction and the relations between the executive dysfunction and lacunar infarctions. Methods 39 senior volunteers were divided into lacunar infarction group (n = 14) and non- lacunar infarction group (n =25) after undergoing head CT and MRI examination. The executive function in the two groups was compared by neuropsychological tests, and the relations between the number of lacunar infarction and the damage of executive function were analyzed. Results The scores of executive function tests in lacunar infarction group were 8.73 ±3.47 ( frontal assessment battery, FAB ), 8. 73 ± 3.47 ( executive clock-drawing task, CLOX) and 29.75 ± 12. 17 ( vocabulary test, RV R) respectively, but in non-lacunar infarction group they were 11.66 ± 2.37,12.15 ± 2.36,and 38.24 ± 8.93 respectively, and the differences were significant (P < 0. 05). The one-factor regressive analysis showed that the number of lacunar infarction was negatively related to the three

  3. Correlation analysis between the carotid artery ather osclerosis severity of patients with lacunar infarct and the level of serum uric acid, high-sensitivity C-reactive protein

    Directory of Open Access Journals (Sweden)

    WANG Shu

    2013-01-01

    Full Text Available Background Nowadays, clinical practice shows that the number of patients with cerebral infarction increases year by year in young and middle-aged adults with unclear causes. This paper aims to investigate the correlation between the level of serum uric acid (UA, high-sensitivity C-reactive protein (hsCRP and the degree of carotid atherosclerosis by detecting the level of UA, hsCRP and carotid intima-media thickness (IMT in young and middle-aged patients with lacunar infarct. Methods By using Holland Philips HT-11 color Doppler ultrasonic diagnostic apparatus with linear type probe and 7.50MHz frequency, IMT of end-diastolic distal and bifurcation of arteria carotis communis and proximal internal carotid artery were measured respectively on 186 patients with definitely diagnosed lacunar infarct. As a result, average values were taken as the IMT values. IMT < 1.00 mm was regarded as negative result and 1.00 mm ≤IMT < 1.20 mm was thickening of carotid artery intima. Carotid artery plaque formation was regarded with echo structure existing in the lumen or abnormal blood flow deficits into the lumen, or local IMT ≥1.20 mm at vertical and horizontal scan. At the same time, the levels of UA and hsCRP were detected, and correlation analysis was made between them and IMT. Results The values of UA, hsCRP and IMT in the case group were higher than that in the control group (P = 0.000. The differences among the case subgroups including IMT thickening group, plaque formation group and IMT normal group were statistically significant (P < 0.01, for all. There was linear correlation between the levels of UA, hsCRP and IMT ( r = 0.923, P = 0.000; r = 0.955, P = 0.008. Conclusion UA and hsCRP involve in the formation of atherosclerosis plaque and play an important role in the first-onset lacunar infarct patients without hypertension and other risk factors.

  4. Lacunarity for compact groups.

    Science.gov (United States)

    Edwards, R E; Hewitt, E; Ross, K A

    1971-01-01

    Let G be a compact Abelian group with character group X. A subset Delta of X is called a [unk](q) set (1 < q < infinity) if for all trigonometric polynomials f = [unk](k=1) (n) alpha(k)chi(k) (chi(1),...,chi(n) [unk] Delta) an inequality parallelf parallel(q) [unk] [unk] parallelf parallel(1) obtains, where [unk] is a positive constant depending only on Delta. The subset Delta is called a Sidon set if every bounded function on Delta can be matched by a Fourier-Stieltjes transform. It is known that every Sidon set is a [unk](q) set for all q. For G = T, X = Z, Rudin (J. Math. Mech., 9, 203 (1960)) has found a set that is [unk](q) for all q but not Sidon. We extend this result to all infinite compact Abelian groups G: the character group X contains a subset Delta that is [unk](q) for all q, 1 < q < infinity, but Delta is not a Sidon set.

  5. Hyperpolarized {sup 3}helium magnetic resonance ventilation imaging of the lung in cystic fibrosis: comparison with high resolution CT and spirometry

    Energy Technology Data Exchange (ETDEWEB)

    McMahon, Colm J.; Dodd, Jonathan D.; Skehan, Stephen J.; Masterson, James B. [St. Vincent' s University Hospital, Department of Radiology, Dublin (Ireland); Hill, Catherine; Woodhouse, Neil; Wild, Jim M.; Fichele, Stan [Royal Hallamshire Hospital, The Unit of Academic Radiology, University of Sheffield, Sheffield (United Kingdom); Gallagher, Charles G. [St. Vincent' s University Hospital, Department of National Referral Centre for Adult Cystic Fibrosis, Dublin (Ireland); Beek, Edwin J.R. van [Royal Hallamshire Hospital, The Unit of Academic Radiology, University of Sheffield, Sheffield (United Kingdom); University of Iowa, Department of Radiology, Carver College of Medicine, Iowa City, IA (United States)

    2006-11-15

    The purpose of this study was to compare hyperpolarized {sup 3}helium magnetic resonance imaging ({sup 3}He MRI) of the lungs in adults with cystic fibrosis (CF) with high-resolution computed tomography (HRCT) and spirometry. Eight patients with stable CF prospectively underwent {sup 3}He MRI, HRCT, and spirometry within 1 week. Three-dimensional (3D) gradient-echo sequence was used during an 18-s breath-hold following inhalation of hyperpolarized {sup 3}He. Each lung was divided into six zones; {sup 3}He MRI was scored as percentage ventilation per lung zone. HRCT was scored using a modified Bhalla scoring system. Univariate (Spearman rank) and multivariate correlations were performed between {sup 3}He MRI, HRCT, and spirometry. Results are expressed as mean{+-}SD (range). Spirometry is expressed as percent predicted. There were four men and four women, mean age=31.9{+-}9 (20-46). Mean forced expiratory volume in 1 s (FEV){sub 1}=52%{+-}29 (27-93). Mean {sup 3}He MRI score=74%{+-}25 (55-100). Mean HRCT score=48.8{+-}24 (13.5-83). The correlation between {sup 3}He MRI and HRCT was strong (R={+-}0.89, p<0.001). Bronchiectasis was the only independent predictor of {sup 3}He MRI; {sup 3}He MRI correlated better with FEV{sub 1} and forced vital capacity (FVC) (R=0.86 and 0.93, p<0.01, respectively) than HRCT (R={+-}0.72 and {+-}0.81, p<0.05, respectively). This study showed that {sup 3}He MRI correlates strongly with structural HRCT abnormalities and is a stronger correlate of spirometry than HRCT in CF. (orig.)

  6. Mapas Lacunares Activación cartográfi ca del espacio vacío

    Directory of Open Access Journals (Sweden)

    Roger Pàez i Blanch

    2015-05-01

    Full Text Available ResumenEl mapa se ha venido utilizado habitualmente como documento que  representa la realidad de manera objetiva y pretendidamente neutra. Sin embargo, el mapa no sólo representa, sino que construye la realidad de manera concreta, a partir de una selección limitada de parámetros que hacen posible orientar una cierta mirada sobre el mundo. Esta orientación específi ca de la realidad que el mapa lleva a cabo, abre posibilidades de transformación de la misma sobre las que la arquitectura, entre otrasdisciplinas, puede trabajar. Llamamos cartografía operativa la producción y el uso de mapas para ampliar la concepción de la realidad y promover su transformación. El presente artículo trata de la activación cartográfica del espacio vacío. A través de una serie de ejemplos, acota algunas de las maneras en las cuales las prácticas cartográficas informan nuestra comprensión del espacio vacío. Los ejemplos, que están presentados bajo cinco tipologías de mapas lacunares, representan distintos modos de  cartografiar el vacío que articulan una actitud crítica respecto los propios procesos cartográfi cos y los usos a los cuales pueden ser sometidos. Estos mapas pretenden mostrar como ciertas cartografías construyen la realidad de manera concreta e orientada a partir de la activación del vacío, enriqueciendo el diálogo permanente entre realidad y representación, en aras de abrir nuevos campos de transformación de lo real.AbstractMaps have generally been used as documents that represent reality in an objective and allegedly neutral way. Maps do not just represent reality, however, they also construct it in a specific way. They activate a limited selection of parameters which allow for orienting a particular perspective on the world. This orientation of reality that is characteristic of maps opens up possibilities for the transformation of reality, which can be brought into play by architecture or other disciplines. We use the

  7. 血管紧张素转换酶基因多态性与高血压病早期腔隙性脑梗死的关系%Relationships between angiotensin-converting enzyme gene polymorphism and lacunar infarction in early stage of essential hypertension

    Institute of Scientific and Technical Information of China (English)

    徐岩; 毛建华

    2003-01-01

    AIM:To investigate the relationships between angiotensin converting enzyme gene polymorphism and lacunar infarction in patients with essential hypertension.METHODS:Polymerase chain reaction(PCR) was used to determine the genotypes for an insertion/deletion polymorphism of 287 pb fragment of ACE gene in 50 healthy persons,50 patients with simple essential hypertension and 30 patients with essential hypertension and lacunar infarction.RESULTS:There was no significant difference of genotype and allele between healthy persons and patients with simple essential hypertension;but there was significant difference of D allele and DD genotype of ACE gene between esential hypertensive patients with lacunar infarction and patients with simple essential hypertension and healthy persons.CONCLUSION:There is a significant relation between ACE gene polymorphism and essential hypertensive patients with lacunar infarction.

  8. Correlation between lacunar infarction and glomeruar filtration rate in elderly patients%老年患者腔隙性脑梗死与肾小球滤过率的关系

    Institute of Scientific and Technical Information of China (English)

    李娜; 李辉; 胡新国; 程玲; 吴卫平; 管维平

    2012-01-01

    [Objective To study the correlation between lacunar infarction(LI) and glomeruar filtration rate(GFR) in elderly patients. Methods One hundred and twenty-seven MRI-confirmed male LI patients aged ≥80 years were divided into single lesion group(n = 35) and multiple lesion group(w = 92) according to the number of lesions. Following clinical data were collected,including 24 hdynamic blood pressure,age,BMI,and history of smoking,alcohol dinking,hypertension,diabetes mellitus,heart disease,and serum creatinine(SCr) and blood-lipid levels. GFR was estimated according to the Cockcroft-Gault equation. Correlation between GFR and LI level was analyzed by multiple logistic regression analysis. Results The SCr level was significantly higher while the GFR was significantly lower in multiple lesion group with its GFR <60 ml/(min ? 1. 73 m2) than in single lesion group(P<0. 05). Logistic regression analysis showed that the low GFR was closely correlated with the LI level, and the lower the GFR was, the higher the incidence of LI was (OR = 2. 14,P = 0. Oil). Conclusion Low GFR is an important risk factor for LI in elderly patients and can thus be used as a warning factor for LI.%目的 探讨老年(≥80岁)患者腔隙性脑梗死(lacunar infarction,LI)与肾小球滤过率(glomeruar filtration rate,GFR)的相关性.方法 选择经头颅MRI证实的老年男性LI患者127例,根据病灶数目分为单发组35例和多发组92例.采集患者的24 h动态血压、年龄、体重指数、吸烟、饮酒、血清肌酐、高血压、血脂、糖尿病、心脏病等临床资料,采用Cockcroft-Gault公式估算GFR.采用多因素logistic回归分析LI与GFR的相关性.结果 与单发组比较,多发组患者血清肌酐、GFR<60 ml/(min·1.73 m2)明显升高(P<0.01),GFR明显降低(P<0.05).logistic回归分析显示,GFR降低与LI的发生密切相关(P<0.05),GFR降低越严重,LI发生率越高(OR=2.14,P=0.011).结论 GFR降低可能为老年LI的重要危险因素,或可成为LI的预警因素.

  9. A hybrid multibreath wash-in wash-out lung function quantification scheme in human subjects using hyperpolarized (3) He MRI for simultaneous assessment of specific ventilation, alveolar oxygen tension, oxygen uptake, and air trapping.

    Science.gov (United States)

    Hamedani, Hooman; Kadlecek, Stephen; Xin, Yi; Siddiqui, Sarmad; Gatens, Heather; Naji, Joseph; Ishii, Masaru; Cereda, Maurizio; Rossman, Milton; Rizi, Rahim

    2017-08-01

    To present a method for simultaneous acquisition of alveolar oxygen tension (PA O2 ), specific ventilation (SV), and apparent diffusion coefficient (ADC) of hyperpolarized (HP) gas in the human lung, allowing reinterpretation of the PA O2 and SV maps to produce a map of oxygen uptake (R). An imaging scheme was designed with a series of identical normoxic HP gas wash-in breaths to measure ADC, SV, PA O2 , and R in less than 2 min. Signal dynamics were fit to an iterative recursive model that regionally solved for these parameters. This measurement was successfully performed in 12 subjects classified in three healthy, smoker, and chronic obstructive pulmonary disease (COPD) cohorts. The overall whole lung ADC, SV, PA O2 , and R in healthy, smoker, and COPD subjects was 0.20 ± 0.03 cm(2) /s, 0.39 ± 0.06,113 ± 2 Torr, and 1.55 ± 0.35 Torr/s, respectively, in healthy subjects; 0.21 ± 0.03 cm(2) /s, 0.33 ± 0.06, 115.9 ± 4 Torr, and 0.97 ± 0.2 Torr/s, respectively, in smokers; and 0.25 ± 0.06 cm(2) /s, 0.23 ± 0.08, 114.8 ± 6.0Torr, and 0.94 ± 0.12 Torr/s, respectively, in subjects with COPD. Hetrogeneity of SV, PA O2 , and R were indicators of both smoking-related changes and disease, and the severity of the disease correlated with the degree of this heterogeneity. Subjects with symptoms showed reduced oxygen uptake and specific ventilation. High-resolution, nearly coregistered and quantitative measures of lung function and structure were obtained with less than 1 L of HP gas. This hybrid multibreath technique produced measures of lung function that revealed clear differences among the cohorts and subjects and were confirmed by correlations with global lung measurements. Magn Reson Med 78:611-624, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  10. Iris Feature Extraction Algorithm Using Vertically Expanded Blanket Dimension and Lacunarity%基于毯子维和缺项的虹膜特征提取算法

    Institute of Scientific and Technical Information of China (English)

    刘凯; 周卫东; 王玉

    2011-01-01

    Iris feature extraction is important in iris recognition. An iris feature extraction algorithm is proposed by using combination of blanket dimension and lacunarity. Because Human iris texture is characterized by fractal geometry due to its rich self-similarity and abundant variation, vertically expanded blanket dimension is employed to represent iris texture variation and radial pattern at different resolution levels. Lacunarity is introduced to extract iris features that have different texture and fractal patterns but have same fractal dimension value. The combination of blanket dimension and lacunarity in iris feature extraction can embody the minute change of texture information comprehensively, and improve the capacity of iris classification. The experimental results on the CASIA-IrisV3-Interval iris database show that the combination of blanket dimension and lacunarity can extract iris textural features accurately and effectively, and high performance for iris recognition is achieved by using those features.%虹膜特征提取是虹膜识别的一个关键环节.文中提出一种毯子维和缺项相结合的虹膜特征提取算法.利用虹膜纹理的自相似和丰富的变化细节所具有的分形几何特性,采用纵向扩展毯子维表达不同分辨能力下虹膜纹理的变化及其辐射排列特点.通过引入缺项进一步提取不同纹理和分形表现却具有相同分形维数的虹膜特征.两者的结合能够更加全面地反映虹膜纹理的细腻变化.将归一化虹膜图像灰度值的毯子维及缺项用于虹膜分类,提高对虹膜的分类能力.针对CASIA-IrisV3-Interval数据库的仿真结果表明,纵向扩展毯子维结合缺项能够有效、快速提取虹膜的纹理信息,所获得的特征具有高的虹膜识别性能.

  11. Contribution to the determination of the double angular and energy differential neutron albedo. Application to the propagation in lacunar medium; Contribution a la determination de l'albedo doublement differentiel en angle et en energie des neutrons. Application a la propagation dans les milieux lacunaires

    Energy Technology Data Exchange (ETDEWEB)

    Litaize, O

    2000-07-01

    The goal of this thesis is to study the neutron propagation by reflection from lacunar medium interfaces. The most efficient method to calculate this type of propagation is to use the concept of albedo. Actual version of NARCISSE code uses a simple formulation of angular differential albedos and so, can only treat single reflections. Multiple reflections treatment needs the knowledge of neutron spectrum after reflection. This energetic information is contained in double angular and energy differential albedos. The first step of this study consists to generate these albedos for various materials. Several methods have been tested and the Monte Carlo method was retained. A new estimator has been developed and validated in the Mote Carlo transport code TRIPOLI-4. It computes, during the simulation of the neutron history, the angular and energy reflection probability at each collision site. The second step consists to generate an interpolation scheme and albedo libraries for various materials. A new version of NARCISSE was developed to use these libraries and the interpolation module. Spectrum and dose rates comparisons were made between codes to validate these albedos. The neutron propagation by multiple reflections can be studied now, by using this new version of Narcisse. (author)

  12. CT对腔隙性脑梗死患者近期预后风险的评估%The Risk of Short-term Prognosis Evaluation Values of CT for the Patients with Lacunar Infarction

    Institute of Scientific and Technical Information of China (English)

    刘东顺; 张敏丽; 李翠乔; 司翠权

    2015-01-01

    目的:探讨CT对腔隙性脑梗死患者近期预后风险的评估价值.方法:选取2011年6月-2014年8月笔者所在医院收治的腔隙性脑梗死患者80例,都进行CT检测,同时选择PRR比率和NIHSS评分进行近期预后风险评估.结果:腔隙性脑梗死患者的CT主要表现为形态卵圆形,病灶内部密度大,伴随有豆状核钙化;同时梗死区的CBF和CBV值都明显少于缺血半暗带区,而MTT值明显高于缺血半暗带区(P<0.05).80例患者的PRR比率为(67.33±2.19)%,NIHSS评分为(34.09±12.44)分,Pearson分析显示CBF和CBV值与PRR比率和NIHSS评分存在明显负相关(P<0.05),而MTT值与PRR比率和NIHSS评分存在明显正相关(P<0.05).结论:腔隙性脑梗死在CT灌注参数上有很好的特异性表现,同时对于近期预后风险有很好的指导判定作用,值得推广应用.%Objective:To investigate the risk of short-term prognosis evaluation values of CT for the patients with lacunar infarction. Method:80 lacunar infarction patients which were admitted to our hospital from June 2011 to August 2014 were selected,all the patients were performed CT detection,and the PRR rates and NIHSS scores for the short-term prognosis risk assessment were choosed.Result:CT attenuation mainly for patients with lacunar infarction were showed oval shape,large lesions internal density,accompanied lenticular nucleus calcification;and the CBF and CBV values in the infarct zone were significantly less than the ischemic penumbra,and MTT were significantly higher than the ischemic penumbra(P<0.05).80 patients of the PRR ratios were (67.33±2.19)%,NIHSS scores were 34.09±12.44 points,Pearson analysis showed that CBF and CBV values were negative correlated to the PRR ratio and NIHSS scores(P<0.05),while the values of MTT values were significant positive correlated to the PRR ratio and NIHSS scores(P<0.05).Conclusion:Lacunar infarction on CT perfusion parameters has good specific performance,while has risk of short

  13. Strategic Role of Frontal White Matter Tracts in Vascular Cognitive Impairment: A Voxel-Based Lesion-Symptom Mapping Study in CADASIL

    Science.gov (United States)

    Duering, Marco; Zieren, Nikola; Herve, Dominique; Jouvent, Eric; Reyes, Sonia; Peters, Nils; Pachai, Chahin; Opherk, Christian; Chabriat, Hugues; Dichgans, Martin

    2011-01-01

    Cerebral small vessel disease is the most common cause of vascular cognitive impairment. It typically manifests with lacunar infarcts and ischaemic white matter lesions. However, little is known about how these lesions relate to the cognitive symptoms. Previous studies have found a poor correlation between the burden of ischaemic lesions and…

  14. Cerebral Small Vessel Disease and Motoric Cognitive Risk Syndrome: Results from the Kerala-Einstein Study

    Science.gov (United States)

    Wang, Nan; Allali, Gilles; Kesavadas, Chandrasekharan; Noone, Mohan L.; Pradeep, Vayyattu G.; Blumen, Helena M.; Verghese, Joe

    2017-01-01

    Background The contribution of cerebral small vessel disease to cognitive decline, especially in non-Caucasian populations, is not well established. Objective We examined the relationship between cerebral small vessel disease and motoric cognitive risk syndrome (MCR), a recently described pre-dementia syndrome, in Indian seniors. Methods 139 participants (mean age 66.6 ± 5.4 y, 33.1% female) participating in the Kerala-Einstein study in Southern India were examined in a cross-sectional study. The presence of cerebral small vessel disease (lacunar infarcts and cerebral microbleeds (CMB)) and white matter hyperintensities on MRI was ascertained by raters blinded to clinical information. MCR was defined by the presence of cognitive complaints and slow gait in older adults without dementia or mobility disability. Results Thirty-eight (27.3%) participants met MCR criteria. The overall prevalence of lacunar infarcts and CMB was 49.6% and 9.4%, respectively. Lacunar infarcts in the frontal lobe, but no other brain regions, were associated with MCR even after adjusting for vascular risk factors and presence of white matter hyperintensities (adjusted Odds Ratio (aOR): 4.67, 95% CI: 1.69–12.94). Frontal lacunar infarcts were associated with slow gait (aOR: 3.98, 95% CI: 1.46–10.79) and poor performance on memory test (β: −1.24, 95% CI: −2.42 to −0.05), but not with cognitive complaints or non-memory tests. No association of CMB was found with MCR, individual MCR criterion or cognitive tests. Conclusions Frontal lacunar infarcts are associated with MCR in Indian seniors, perhaps, by contributing to slow gait and poor memory function. PMID:26757037

  15. Mechanisms of cognitive impairment in cerebral small vessel disease: multimodal MRI results from the St George's cognition and neuroimaging in stroke (SCANS study.

    Directory of Open Access Journals (Sweden)

    Andrew J Lawrence

    Full Text Available Cerebral small vessel disease (SVD is a common cause of vascular cognitive impairment. A number of disease features can be assessed on MRI including lacunar infarcts, T2 lesion volume, brain atrophy, and cerebral microbleeds. In addition, diffusion tensor imaging (DTI is sensitive to disruption of white matter ultrastructure, and recently it has been suggested that additional information on the pattern of damage may be obtained from axial diffusivity, a proposed marker of axonal damage, and radial diffusivity, an indicator of demyelination. We determined the contribution of these whole brain MRI markers to cognitive impairment in SVD. Consecutive patients with lacunar stroke and confluent leukoaraiosis were recruited into the ongoing SCANS study of cognitive impairment in SVD (n = 115, and underwent neuropsychological assessment and multimodal MRI. SVD subjects displayed poor performance on tests of executive function and processing speed. In the SVD group brain volume was lower, white matter hyperintensity volume higher and all diffusion characteristics differed significantly from control subjects (n = 50. On multi-predictor analysis independent predictors of executive function in SVD were lacunar infarct count and diffusivity of normal appearing white matter on DTI. Independent predictors of processing speed were lacunar infarct count and brain atrophy. Radial diffusivity was a stronger DTI predictor than axial diffusivity, suggesting ischaemic demyelination, seen neuropathologically in SVD, may be an important predictor of cognitive impairment in SVD. Our study provides information on the mechanism of cognitive impairment in SVD.

  16. 伴基底节钙化的婴幼儿外伤后腔隙性脑梗塞%Pusttraumatic cerebral lacunar infarction in infants with basal ganglia calcifications

    Institute of Scientific and Technical Information of China (English)

    金惠明; 孙莲萍; 鲍南

    2001-01-01

    Objective To explore the pathologic mechanism and treatment of posttraumatic cerebral lacunar infarction in infants with basal ganglia calcifications. Methods The symptoms, radiation demonstrations, treatments and prognosis in 20 infants undergoing cerebral infarction following minor cerebral trauma were reviewed retrospectively. Results Posttraumatic cerebral infarctions all occurred in only one side of basal ganglia. It leads to acute hemiplegia in the patients, but no changes of consciousness and no signs of intracranial hypertension were noted. CT scan showed punctate calcification in bilateral basal ganglia and lacunar infarction just beside them. After treatment the infants recovered well within 3months. Conclusions The occurrence of posttraumatic cerebral lacunar infarction is closely associated with basal ganglia calcification, but its mechanism is not clear. It needs to be differentiated from cerebral toxoplasmosis and cytomegalic inclusion disease.%目的探讨伴有基底节钙化的婴幼儿外伤后腔隙性脑梗塞的发病机理和治疗效果。方法总结20例婴幼儿较轻微头颅外伤后发生脑梗塞的症状、影像学表现、治疗效果及预后。结果婴幼儿外伤后脑梗塞均发生于一侧基底节区。l临床表现为不同程度的一侧急性偏瘫、无意识改变及颅内高压症状。CT扫描发现双侧基底节区存在细小点状钙化,腔隙性脑梗塞灶毗邻钙化点。经治疗预后好,随访3个月全部康复。结论婴幼儿外伤后腔隙性脑梗塞的发生与基底节钙化关系密切。但发病机理及基底节钙化的生理过程尚有待探究。本病诊断需与脑弓形虫病及巨细胞包涵体病等相鉴别。

  17. Analysis of the intracranial lesions, cerebrovascular conditions and lacunar infarction in patients with migraine%偏头痛与脑血管发育异常、脑白质变性、脑腔梗关系分析

    Institute of Scientific and Technical Information of China (English)

    赵轶; 席刚明

    2014-01-01

    目的:观察偏头痛患者脑血管情况及颅内病变情况。方法:以住院偏头痛患者为研究对象、同一时期无偏头痛患者为对照,进行神经影像学比较。结果:58例偏头痛患者中,有脑腔梗病灶19例(32.76%),有脑白质变性17例(29.31%),有脑血管异常37例(63.79%)。61例对照组中有脑腔梗病灶9例(14.75%),有脑白质变性5例(8.20%),有脑血管异常13例(21.31%)。2组比较差异均有统计学意义(P<0.05)。结论:偏头痛与脑白质病变、脑腔梗有关,血管因素可能参与偏头痛的发作。%Objective:To obtain the intracranial lesions and cerebrovascular conditions in patients with migraine.Methods:Patient with migraine collected from the hospitalized were compared with patients with non-migraine in their neurimaging findings.Results:Among 58 patients with migraine, 19 had a or more lacunar infarctions;17 had white matter lesions and 37 had cerebrovascular abnormalities, while 61 patients with non-migraine had 9 lacunar infarctions, 5 white matter lesions and 13 cerebrovascular abnormalities. They were all signiifcantly different(P<0.05).Conclusion:Migraine was associated with the white matter lesions and lacunar infarction, while vascular factors may be involved in the migraine.

  18. Lacunarity term as a basis of multiscale quantification of structural components distribution inhomogeneity of multiphase materials; Der Begriff der Lakunaritaet als Grundlage fuer eine Multiskalenquantifizierung der Inhomogenitaet der Verteilung von Strukturkomponenten in Mehrphasenmaterialien

    Energy Technology Data Exchange (ETDEWEB)

    Chmiela, Jerzy [Silesian Univ., Sosnowiec (Poland). Dept. of Materials Science; Slota, Damian [Silesian Univ. of Technology, Gliwice (Poland). Inst. of Mathematics; Szala, Janusz [Silesian Univ. of Technology, Katowice (Poland). Dept. of Materials Science

    2013-08-01

    The paper presents the quantification results of the inhomogeneity of phase distribution in intermetallic alloys from the Mg-Al-Sr system after die-casting and gravity casting, the quantification results of phase {beta} of alloy Ti-6-4 after hydrogen treatment and cyclic heat treatment, and of intragranular regions of diverse crystallographic orientation in the copper microstructure in a state of strain and in a recrystallized state. The quantification of the distribution inhomogeneity, based on the concept of directional lacunarity, is effective and precisely detects the size of inhomogeneity and the degree of its intensity, irrespective of the morphology of microstructural components. An analytical description of inhomogeneity allows comparing the results of quantification, regardless of the size of the sets analyzed. (orig.)

  19. 维生素B12与腔隙性脑梗塞后抑郁的关联研究%Association of Vitamin B12 with Depression after Lacunar Stroke

    Institute of Scientific and Technical Information of China (English)

    李中春; 呙登俊; 江霞

    2013-01-01

    OBJECTIVE To explore the association of serum vitamin B12 with depression after lacunar stroke.METHODS Between June 2009 and June 2012,829 patients with lacunar stroke,according to Hamilton depression scale score,were divided into two groups:group with depression and group without depression.The concentration of serum vitamin B 12 and the ratio of vitamin B12 deficiency were compared.The relationship between Hamilton depression scale score and the concentration of serum vitamin B 12 in the group with depression was analyzed by the curve-fitting method.RESULTS The group without depression contained 750 cases and the mean concentration of serum vitamin B12 of this group was (172.5±20.4)pmol·L-1.There were 212 cases in the group without depression which were considered as vitamin B 12 deficiency.The group with depression contained 79 cases and the mean concentration of serum vitamin B12 of this group was (139.1±18.2)pmol·L-1.There were 53 cases in the group with depression which were considered as vitamin B12 deficiency.There were significant differences in the concentration of serum vitamin B 12 and the ratio of vitamin B 12 deficiency(P<0.000 1).Inverse curve reflected the relationship between Hamilton depression scale score and the concentration of serum vitamin B 12 in the group with depression.CONCLUSION Depression after lacunar stroke is related to vitamin B12 deficiency.%目的 探讨血清维生素B12与腔隙性脑梗塞后抑郁之间关系.方法 2009年6月—2012年6月腔隙性脑梗塞患者共829例,使用汉密尔顿抑郁量表将患者分为两组:无抑郁组和抑郁组,比较两组间血清维生素B12浓度和维生素B12缺乏者的比例.在抑郁组内对汉密尔顿抑郁量表评分和血清维生素B12浓度进行曲线拟合.结果 无抑郁组患者750例,血清维生素B12平均浓度为(172.5±20.4)pmol·L-1,其中维生素B12缺乏者212例.抑郁组79例,血清维生素B12平均浓度为(139.1± 18.2)pmol·L-1,

  20. 长春西汀联合依达拉奉治疗急性腔隙性脑梗死临床观察%Clinical observation of vinpocetine combined with edaravone in the treatment of acute lacunar infarction

    Institute of Scientific and Technical Information of China (English)

    廖纪华; 郑乃清; 唐锦程; 吴新爱

    2015-01-01

    目的:观察长春西汀注射液联合依达拉奉治疗急性腔隙性脑梗死的临床疗效。方法96例急性腔隙性脑梗死患者随机分为观察组和对照组,各48例,两组在治疗相应基础病和常规抗凝、抗血小板聚集治疗基础上,观察组加用长春西汀注射液及依达拉奉进行治疗,对照组加用倍他司汀注射液及血塞通注射液进行治疗,疗程2周。观察两组治疗效果、记录不良反应、评估安全性。治疗前和治疗2周后进行欧洲脑卒中评分(ESS),用积分评判疗效。结果观察组总有效率为93.8%,优于对照组81.3%,差异具有统计学意义(P<0.05)。两组药物无明显不良反应。结论相比使用倍他司汀+血塞通,长春西汀联合依达拉奉治疗急性腔隙性脑梗死疗效确切,安全性好,值得临床推广应用。%Objective To investigate the clinical effect of vinpocetine combined with edaravone in the treatment of acute lacunar infarction.Methods A total of 96 acute lacunar infarction patients were randomly divided into observation group and control group, with 48 cases in each group. On the basis of treatment for background disease, conventional anticoagulation, and anti-platelet aggregation, the observation group received vinpocetine injection combined with edaravone for treatment, and the control group received betahistine injection and Xuesaitong injection for treatment. Treatment lasted for 2 weeks. Curative effects of the two groups were observed, their adverse reactions were recorded and safety was evaluated. The European stroke scale (ESS) was applied before treatment and in 2 weeks after treatment, and their scores were used for effects evaluation.ResultsTotal effective rate of the observation group was 93.8%, which was much better than 81.3% of the control group. The difference had statistical significance (P<0.05). Both groups had no obvious adverse reactions.Conclusion Compared with betahistine + Xuesaitong

  1. Short-Lived Human Umbilical Cord-Blood-Derived Neural Stem Cells Influence the Endogenous Secretome and Increase the Number of Endogenous Neural Progenitors in a Rat Model of Lacunar Stroke.

    Science.gov (United States)

    Jablonska, Anna; Drela, Katarzyna; Wojcik-Stanaszek, Luiza; Janowski, Miroslaw; Zalewska, Teresa; Lukomska, Barbara

    2016-11-01

    Stroke is the leading cause of severe disability, and lacunar stroke is related to cognitive decline and hemiparesis. There is no effective treatment for the majority of patients with stroke. Thus, stem cell-based regenerative medicine has drawn a growing body of attention due to the capabilities for trophic factor expression and neurogenesis enhancement. Moreover, it was shown in an experimental autoimmune encephalomyelitis (EAE) model that even short-lived stem cells can be therapeutic, and we have previously observed that phenomenon indirectly. Here, in a rat model of lacunar stroke, we investigated the molecular mechanisms underlying the positive therapeutic effects of short-lived human umbilical cord-blood-derived neural stem cells (HUCB-NSCs) through the distinct measurement of exogenous human and endogenous rat trophic factors. We have also evaluated neurogenesis and metalloproteinase activity as cellular components of therapeutic activity. As expected, we observed an increased proliferation and migration of progenitors, as well as metalloproteinase activity up to 14 days post transplantation. These changes were most prominent at the 7-day time point when we observed 30 % increases in the number of bromodeoxyuridine (BrdU)-positive cells in HUCB-NSC transplanted animals. The expression of human trophic factors was present until 7 days post transplantation, which correlated well with the survival of the human graft. For these 7 days, the level of messenger RNA (mRNA) in the analyzed trophic factors was from 300-fold for CNTF to 10,000-fold for IGF, much higher compared to constitutive expression in HUCB-NSCs in vitro. What is interesting is that there was no increase in the expression of rat trophic factors during the human graft survival, compared to that in non-transplanted animals. However, there was a prolongation of a period of increased trophic expression until 14 days post transplantation, while, in non-transplanted animals, there was a

  2. P选择素在原发性高血压伴腔隙性脑梗死患者发病机制中的作用%Effect of P-selectin in primary hypertension associated with lacunar infarction

    Institute of Scientific and Technical Information of China (English)

    龚艳春; 郭冀珍; 史桂英; 石学耕; 龚兰生

    2003-01-01

    目的 观察血小板活化的标志-- P-选择素在原发性高血压伴腔隙性脑梗死患者发病机制中的作用. 方法利用 FITC标记的抗 CD42a单抗(鼠 IgG1) ,PE标记的抗 CD62P单抗(鼠 IgG1) ,CY标记的抗 CD45单抗(鼠 IgG1) ,FITC标记的鼠 IgG1同种型对照免疫球蛋白 ,PE标记的鼠 IgG1同种型对照免疫球蛋白,上述单抗分别标记全血中血小板及白细胞的相关抗原;同时利用流式细胞仪,采取全血三色法流式细胞术方法,检测全血血小板上 P-选择素阳性表达:全血标本中分别加入 3种荧光标记的单克隆抗体 FITC -CD42a, PE-62P及 CY- CD45,室温避光反应 20 min, 10g/L多聚甲醛固定 10 min,用 PBS洗 2次,上机分析. 结果原发性高血压伴腔隙性脑梗死患者血小板 P-选择素阳性表达 [( 23.0± 4.0)% ]明显高于原发性高血压无腔隙性脑梗死患者 [( 16.9± 1.8%) ]及正常人组 [(5.2± 0.7)% ],三者之间相比差异有显著性意义( t=137.4,28.4, P< 0.05). 结论 P-选择素在原发性高血压伴腔隙性脑梗死发病中起重要作用, P-选择素与血管渐进损伤有关.%AIM:To detect the effect of P-selectin,the marker of platelet activation in primary hypertension associated with lacunar infarction. METHODS:FITC-labeled antiCD42a monoclonal antibody(mice IgG1),PE labeled antiCD62P monoclonal antibody(mice IgG1),CY labeled antiCD45 monoclonal antibody(mice IgG1),FITC labeled mice IgG1 isotype matched immune globulin,PE labeled mice IgG contrast immunoglobulin were used to label corresponding antigens of platelets and leukocytes in whole blood.At the same time, P-selectin on the platelet was detected by the method of three-color cytometery in whole blood;Three monoclonal antibodies with fluorescence labeled, FITC-CD42a, PE -62P and CY-CD45 were added in whole blood specimen and incubated for 20 min without light and under room temperature,over night.Then specimen was fixed with citromint for 10 min and washed with PBS

  3. Histological analysis of the alterations on cortical bone channels network after radiotherapy: A rabbit study.

    Science.gov (United States)

    Rabelo, Gustavo Davi; Beletti, Marcelo Emílio; Dechichi, Paula

    2010-10-01

    The aim of this study was to evaluate the effects of radiotherapy in cortical bone channels network. Fourteen rabbits were divided in two groups and test group received single dose of 15 Gy cobalt-60 radiation in tibia, bilaterally. The animals were sacrificed and a segment of tibia was removed and histologically processed. Histological images were taken and had their bone channels segmented and called regions of interest (ROI). Images were analyzed through developed algorithms using the SCILAB mathematical environment, getting percentage of bone matrix, ROI areas, ROI perimeters, their standard deviations and Lacunarity. The osteocytes and empty lacunae were also counted. Data were evaluated using Kolmogorov-Smirnov, Mann Whitney, and Student's t test (P lacunarity were found between groups. In conclusion, the radiotherapy causes reduction of bone matrix and modifies the morphology of bone channels network. © 2010 Wiley-Liss, Inc.

  4. Evaluation about Montreal cognitive assessment scale in patients with lacunar infarction%蒙特利尔认知评估量表在腔隙性脑梗死患者中的临床应用观察

    Institute of Scientific and Technical Information of China (English)

    徐心; 吴杨; 胡晓蕾

    2013-01-01

    害的认知领域不同.%Objective To evaluate the application value of Montreal Cognitive Assessment (MoCA)in patients with lacunar infarction (LI),and to explore the relevance of cognitive impairment in different areas and imaging of lesion site in patients with LI.Methods 159 cases were divided into three groups according to the MoCA and MMSE score,the control group with normal cognitive function (MMSE score above the demarcation line and MoCA score ≥ 26 points),the observation group (MMSE score above the demarcation line and the MoCA < 26points),the cognitive dysfunction group(MMSE score below the demarcation line and MoCA < 26 points).The demographic data of all patients,the LI lesion site in head MRI and the MoCA and MMSE score were recorded,the relation between the LI lesion site in head MRI and the MoCA and MMSE score were analysed.The results were calculated with SPSS 17.0.Results (1) The isolation rate of MMSE and MoCA of abnormal cognitive function in patients with LI were 38.36% and 83.01%.The MoCA scores of patients with abnormal MMSE score were also abnormal.In patients with normal MMSE score (accounting for 61.63% of the sample),the MoCA scores were abnormal which accounting for 44.65 % of total study population.(2)The head MRI findings showed that the lesion site of patients with LI occured multiply in frontal lobe,parietal lobe,basal ganglia,the most common,then the thalamus,brain stem and periventricular white matter.(3)The different infarct lesion sites were related to the different field of cognitive impairment(P < 0.05).The damage of the frontal lobe lesions were related to the damage of executive function,visuospatial ability,attention and calculation power,language,abstract force and memory.The damage of parietal lobe lesions were related to the damage of executive function,visuospatial ability damage.The harm of basal ganglia lesions were related to the damage of executive function,memory,calculation and attention damage.The injure of hypothalamic lesions were

  5. CT 与 MRI 对腔隙性梗死的诊断价值分析%Analysis of compared CT with MRI in diagnosis value of lacunar infarction

    Institute of Scientific and Technical Information of China (English)

    严补生

    2015-01-01

    目的:比较C T与M RI对腔隙性梗死的诊断价值。方法选择腔隙性梗死患者40例为研究对象,均于入院3 h内行急诊螺旋CT及MRI检查。以临床诊断为准,观察CT 与MRI对腔隙性梗死病灶数量及部位诊断情况。比较CT 与MRI对发病<24 h、24~72 h、>72 h患者脑内病灶及径线<5 mm、5~10 mm和>10~15 mm病灶检出情况。结果(1)脑梗死病灶分布于额叶6例,顶叶6例,颞叶6例,枕叶4例,基底节区8例,丘脑3例,脑干3例,小脑4例。40例患者中,C T共显示21例患者存在脑梗死病灶,共显示病灶45处。M RI共显示38例患者存在脑梗死病灶,共显示病灶79处。M RI对脑梗死病灶检出率显著高于C T ,差异具有统计学意义( P<0.05)。(2)M RI对<24 h、24~72 h脑梗死病灶的检出率显著高于CT ,差异具有统计学意义(P<0.05)。两者在>72 h病灶的检出中,差异无统计学意义(P>0.05)。(3)其中MRI对径线<5 mm及5~10 mm腔隙性梗死病灶检出率显著高于CT ,差异具有统计学意义(P<0.05)。在病灶径线10~15 mm病灶的检出中,MRI及CT比较差异无统计学意义(P>0.05)。结论在腔隙性梗死的诊断中,MRI较CT更具有优势。%Objective To compare the value of CT and MRI in diagnosis of lacunar infarction.Methods 40 cases with la‐cunar cerebral infarction as the objects ,which were detected by spiral CT and MRI examination within 3 h admitted to our hos‐pital. Lesion number and site of cerebral lacunar infarction by CT and MRI were observed.The onset of cerebral infarction within 24 h ,between 24 h and 72 h ,more than 72 h;and diameter less than 5 mm ,between 5 mm and 10 mm ,between >10 and 15 mm detected by CT and MRI were compared.Results 6 cases of cerebral infarction lesions located in frontal lobe ,6 ca‐ses in parietal lobe ,6 cases in temporal lobe ,4 cases in occipital lobe ,8 cases in basal ganglia

  6. 皮层下动脉硬化性脑病100例临床CT分析%CT and MRI T2WI, and FLAIR and DWI in diagnostic value of cerebral lacunar infarction and its prognosis analysis

    Institute of Scientific and Technical Information of China (English)

    罗青毅; 邹习忠; 冉强; 董志鹏

    2014-01-01

    目的:探讨皮层下动脉硬化性脑病颅脑ct诊断的意义和价值。方法结合我院临床诊断为皮层下动脉硬化性脑病, ct表现为侧脑室周围脑白质脱髓鞘改变的100例病例,按Goto分类法,将侧脑室前角周围脑白质脱髓鞘改变程度不同分为三型的标准,进行临床和影像综合分析。结果按Goto分类法Ⅰ型和Ⅱ型63例,临床表现轻,Ⅲ型37例,症状重,常偏瘫和言语不清,ct表现伴有脑萎缩(96例),腔隙性脑梗死(74例),伴大面积脑梗死(8例)、脑出血(7例)、脑积水和蛛网膜下腔积液(12例)。结论 ct检查对皮层下动脉硬化性脑病的诊断具有重要的价值,对于临床在预防、诊断和治疗皮层下动脉硬化性脑病方面具有重要意义。%Objectiveto explore the value of ct in diagnosis of subcortical arteriosclerotic encephalopathy (sae). Methods100 patients were deifnitely diagnosed as SAE by clinic. CT showed low density of surrounding bilateral ventricle. Demyelinating encephalopathy of frontal horn of bilateral ventricle were divided into three types according to the classiifcation of Goto.Results clinical presentations showed mild in typesⅠ andⅡ in 63 patients, severe symptoms were found in 37 patients, including hemiplegia, and barylalia. ct appeared cerebral atrophy in 96 patients; cerebral lacunar infarction in 74; diffuse cerebral infarction in 8; hemorrhage in 7; and hydrocephalus and hydrops of subarachnoid space in 12.Conclusion ct was very valuable on diagnosis and evaluation of subcortical arteriosclerotic encephalopathy.

  7. Hyperpolarized (3)He magnetic resonance imaging: comparison with four-dimensional x-ray computed tomography imaging in lung cancer.

    Science.gov (United States)

    Mathew, Lindsay; Wheatley, Andrew; Castillo, Richard; Castillo, Edward; Rodrigues, George; Guerrero, Thomas; Parraga, Grace

    2012-12-01

    Pulmonary functional imaging using four-dimensional x-ray computed tomographic (4DCT) imaging and hyperpolarized (3)He magnetic resonance imaging (MRI) provides regional lung function estimates in patients with lung cancer in whom pulmonary function measurements are typically dominated by tumor burden. The aim of this study was to evaluate the quantitative spatial relationship between 4DCT and hyperpolarized (3)He MRI ventilation maps. Eleven patients with lung cancer provided written informed consent to 4DCT imaging and MRI performed within 11 ± 14 days. Hyperpolarized (3)He MRI was acquired in breath-hold after inhalation from functional residual capacity of 1 L hyperpolarized (3)He, whereas 4DCT imaging was acquired over a single tidal breath of room air. For hyperpolarized (3)He MRI, the percentage ventilated volume was generated using semiautomated segmentation; for 4DCT imaging, pulmonary function maps were generated using the correspondence between identical tissue elements at inspiratory and expiratory phases to generate percentage ventilated volume. After accounting for differences in image acquisition lung volumes ((3)He MRI: 1.9 ± 0.5 L ipsilateral, 2.3 ± 0.7 L contralateral; 4DCT imaging: 1.2 ± 0.3 L ipsilateral, 1.3 ± 0.4 L contralateral), there was no significant difference in percentage ventilated volume between hyperpolarized (3)He MRI (72 ± 11% ipsilateral, 79 ± 12% contralateral) and 4DCT imaging (74 ± 3% ipsilateral, 75 ± 4% contralateral). Spatial correspondence between 4DCT and (3)He MRI ventilation was evaluated using the Dice similarity coefficient index (ipsilateral, 86 ± 12%; contralateral, 88 ± 12%). Despite rather large differences in image acquisition breathing maneuvers, good spatial and significant quantitative agreement was observed for ventilation maps on hyperpolarized (3)He MRI and 4DCT imaging, suggesting that pulmonary regions with good lung function are similar between modalities in this small group of patients with

  8. Musical hallucinations associated with pontine lacunar lesions.

    Science.gov (United States)

    Serby, Michael J; Hagiwara, Mari; O'Connor, Lisa; Lalwani, Anil K

    2013-01-01

    Three elderly patients experienced musical hallucinations (MH) in the context of hearing loss. In at least two of the cases, the onset was sudden. All three patients had pontine T2/FLAIR hyperintense foci on MR scan after the onset of the MH.

  9. 腔隙性梗死和脑白质病变患者的认知损害%Cognitive impairment in patient with lacunar infarct and white matter lesion

    Institute of Scientific and Technical Information of China (English)

    张永红; 王海峰; 王新; 张莉; 邢成名

    2014-01-01

    目的 探讨腔隙性梗死(lacunar infarct,LI)和脑白质病变(white matter lesion,WML)患者认知损害的特征及其危险因素.方法 纳入年龄65 ~ 75岁的LI和WML住院患者,收集其人口统计学和临床资料.LI和WML通过MRI确诊.采用蒙特利尔认知评估量表(Montreal Cognitive Assessment,MoCA)评价认知功能.采用抑郁自评量表和汉密尔顿焦虑量表排除抑郁和焦虑患者.根据MoCA总分将患者分为认知损害组和认知功能正常组,比较两组人口统计学和临床资料.采用多变量logistic回归分析确定认知损害的独立危险因素.对LI和WML的认知损害特征进行比较.结果 共纳入130例LI或WML患者.其中,92例存在认知损害,38例认知功能正常;85例存在LI,45例存在WML;男性53例,女性77例.单变量分析显示,认知损害组受教育年限[(7.54±4.65)年对(11.29±3.17)年;t=4.286,P=0.001]显著性低于认知正常组,而高血压(54.6%对16.2%;x2=4.477,P=0.018)、高脂血症(53.1%对16.2%;x2=5.263,P =0.044)、糖尿病(46.9%对10.8%;x2=3.827,P=0.017)以及LI(43.8%对21.5%;x2=3.928,P=0.015)和WML(26.9%对7.7%;x2=4.072,P=0.009)的构成比显著性高于认知正常组.多变量logistic回归分析显示,受教育年限[优势比(odds ratio,OR)1.305,95%可信区间(confidence interval,CI)1.104 ~7.975;P=0.001]、糖尿病(OR 1.328,95% CI 1.292~3.422;P=0.015)、高血压(OR1.978,95%CI1.034~5.443;P=0.028)、LI(OR 1.224,95% CI1.004 ~2.007;P=0.013)和WML(OR 1.489,95% CI 1.202~3.778;P=0.010)是认知损害的独立危险因素.WML组MoCA总分[(21.61±5.33)分对(19.19±7.07)分;t=1.841,P=0.038]以及立方体复制[(0.43±0.50)分对(0.31 ±0.47)分;t=1.104,P=0.010]、画钟实验[(2.53 ±0.89)分对(2.04±1.22)分;t=2.229,P=0.008]、字母辨别[(0.85±0.36)分对(0.62±0.50)分;t=2.585 P=0.000]和100连续减7[(2.62±0.79)分对(2.19±1.17)分;=2.113;P=0.001]得分均显著性低于LI组.结论 LI和WML患者均常伴

  10. The correlation of hs-CRP and homocystine level with ESRS in the patents with lacunar infarction%腔隙性脑梗死患者超敏C反应蛋白及同型半胱氨酸水平与ESRS的关系

    Institute of Scientific and Technical Information of China (English)

    石义永; 林传鸿; 余宏; 强锴

    2012-01-01

    目的 探讨腔隙性脑梗死患者超敏C反应蛋白(Hs-CRP)及同型半胱氨酸(Hcy)水平与ESSEN卒中危险评分的关系.方法 125例急性期腔隙性脑梗死患者按ESSEN卒中危险评分将腔隙性脑梗死患者分为低危组(38例)、高危组(71例)、极高危组(16例),进行血浆Hs-CRP和Hcy水平的测定,比较三组间的Hs-CRP和Hcy水平变化及与ESSEN卒中危险评分的关系.结果 ①Hs-CRP水平极高危组显著高于高危组和低危组,(5.00±2.83) ug·ml-1 VS(1.03±1.03)ug·ml-1(P<0.01);(5.00±2.83)ug·ml-1 VS (0.46±0.38) ug·ml-1(P<0.01),高危组显著高于低危组,(1.03±1.03)ug·ml-1 VS (0.46±0.38) ug·ml-1(P<0.05),随着危险因素增加有上升趋势,且Hs-CRP水平同Essen评分呈显著正相关关系(r=0.652,P=0.000).②血浆Hcy水平极高危组与低危、高危组比较差异有统计学意义(P<0.05);且血浆Hcy水平同Essen评分呈正相关关系(r=0.198,p=0.027).③三组年龄、糖尿病患病率、吸烟率、LDL、HDL有统计学意义(P<0.05或<0.01);三组高血压患病率、TC、TG和BMI比较无统计学意义(P>0.05).结论 腔隙性脑梗死患者的Hs-CRP和血浆Hcy水平变化在一定程度上反映患者的危险程度,同Essen评分有良好的相关性.%Objective To investigate the correlation of hs-CRP and homocystine( Hcy )level with Essen Stroke Risk Score( ESRS )in patients with lacunar infarction. Methods According to the ESRS, 125 patients with lacunar infarction were divided into three groups: ow risk group( n = 38 ) ; high risk group ( n =71 ) and very high risk group ( n = 16 ) , plasma Hs -CRP and Hcy levels were measured, the changes of hs-CRP and Hey levels as well as the relationship of hs-CRP and Hcy levels with ESRS were oberved. Results ①)Hs-CRP level in the very high risk group was significantly higher than that in the high risk group and low risk group,( 5. 00 ± 2. 83 ) ug/mL VS (1.03 ± 1.03) ug/mL (P 0. 05 ). Conclusion Hs-CRP and Hcy leves

  11. Location and progression of cerebral small-vessel disease and atrophy, and depressive symptom profiles: the Second Manifestations of ARTerial disease (SMART)-Medea study.

    Science.gov (United States)

    Grool, A M; van der Graaf, Y; Mali, W P Th M; Witkamp, Th D; Vincken, K L; Geerlings, M I

    2012-02-01

    The 'vascular depression' hypothesis states that brain changes located in frontal-subcortical pathways increase vulnerability for specific depressive symptom profiles, but studies examining locations of small-vessel and degenerative changes with individual symptoms are scarce. We examined whether location and progression of white-matter lesions (WMLs), lacunar infarcts and atrophy were associated with motivational and mood symptoms in patients with symptomatic atherosclerotic disease. In 578 patients [63 (s.d.=8) years] of the Second Manifestations of ARTerial disease (SMART)-Medea study, volumes of WMLs and atrophy and visually rated infarcts were obtained with 1.5 T magnetic resonance imaging at baseline and after 3.9 (s.d.=0.4) years' follow-up. Depressive symptoms were assessed with Patient Health Questionnaire-9 at follow-up and categorized into motivational and mood symptoms. Regression analyses adjusted for age, gender, education, Mini-Mental State Examination, physical functioning, antidepressant use and vascular risk factors showed that location in mainly deep white-matter tracts and progression of WMLs were associated with symptoms of anhedonia, concentration problems, psychomotor retardation and appetite disturbance. Lacunar infarcts in deep white matter were associated with greater motivational [Incidence rate ratio (IRR) 1.7, 95% confidence interval (CI) 1.2-2.4] and mood (IRR 1.7, 95% CI 1.1-2.6) sumscores, and with symptoms of psychomotor retardation, energy loss and depressed mood; lacunar infarcts in the thalamus were associated with psychomotor retardation only. Cortical atrophy was associated with symptoms of anhedonia and appetite disturbance. Excluding patients with major depression did not materially change the results. Our findings suggest that disruption of frontal-subcortical pathways by small-vessel lesions leads to a symptom profile that is mainly characteristic of motivational problems, also in the absence of major depression.

  12. Frequency and topography of small cerebrovascular lesions in vascular and in mixed dementia: a post-mortem 7-tesla magnetic resonance imaging study with neuropathological correlates.

    Science.gov (United States)

    De Reuck, Jacques; Auger, Florent; Durieux, Nicolas; Deramecourt, Vincent; Maurage, Claude-Alain; Cordonnier, Charlotte; Pasquier, Florence; Leys, Didier; Bordet, Regis

    2017-01-01

    Introduction: Mixed dementia (MixD) refers to a combination of definite Alzheimer's disease (AD) and vascular encephalopathy. The existence of a "pure" type of vascular dementia (VaD) is controversial. There is a need to find magnetic resonance imaging (MRI) characteristics allowing the distinction between VaD and MixD. The present post-mortem 7.0-tesla MRI compares the frequency or severity and the topography of the small cerebrovascular lesions in brains of patients with VaD and with MixD. Material and methods: Based on neuropathological criteria, 14 brains were classified as VaD, 24 as MixD and 11 as controls. Three coronal sections of a cerebral hemisphere and a horizontal section of a cerebellar hemisphere underwent T2 and T2* 7.0-tesla MRI examination. The mean values and topographic distribution of white matter changes (WMCs), lacunar infarcts (LIs), cortical microbleeds (CoMBs) and cortical microinfarcts (CoMIs) were determined and compared between the different groups. Results: Compared to the controls, both VaD and MixD brains had significantly more severe WMCs and increased numbers of CoMBs and CoMIs. Lacunar infarcts predominated only in the VaD cases. On mutual comparison of VaD and MixD brains, CoMBs and CoMIs predominated in the frontal lobe and the cerebellum of VaD, while were mainly present in the occipital lobe of MixD. White matter changes predominated in the temporal lobe of MixD cases. Lacunar infarcts were significantly increased in the corona radiata and putamen of VaD patients. Conclusions: The present post-mortem MRI study shows clear differences in the distribution and the types of cerebrovascular lesions on high-field MRI, confirming that VaD and MixD are different diseases. .

  13. The Use of Tomosynthesis in the Global Study of Knee Subchondral Insufficiency Fractures.

    Science.gov (United States)

    Nelson, Fred; Bokhari, Omaima; Oravec, Daniel; Kim, Woong; Flynn, Michael; Lumley, Catherine; McPhilamy, Austin; Yeni, Yener N

    2017-02-01

    Subchondral insufficiency fractures (SIF), previously termed spontaneous osteonecrosis of the knee, are marked by a sudden onset of severe pain. Other than the size of the lesion, prediction for progression to joint replacement is difficult. The objective was to determine if quantitative analysis of bone texture using digital tomosynthesis imaging would be useful in predicting more rapid progression to joint replacement. Tomosynthesis studies of 30 knees with documented SIF were quantified by fractal, mean intercept length (MIL), and line fraction deviation analyses. Fractal dimension, lacunarity, MIL, and line fraction deviation variables measured from these analyses were then correlated to short interval progression to joint replacement surgery. Higher odds for joint replacement were related to higher values of the standard deviation of slope lacunarity and to morphometric measures (eg, MIL). Using digital tomosynthesis images for bone texture assessment may help distinguish condylar bone response in SIF, potentially acting as a clinically relevant predictive tool. In the future, contrasting SIF to the more gradual long-term process of osteoarthritis, there may be a better understanding of the different mechanisms for the two conditions. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  14. Hyperpolarized {sup 3}He magnetic resonance imaging: Preliminary evaluation of phenotyping potential in chronic obstructive pulmonary disease

    Energy Technology Data Exchange (ETDEWEB)

    Mathew, Lindsay, E-mail: lmathew@imaging.robarts.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); Department of Medical Biophysics, University of Western Ontario, London (Canada); Kirby, Miranda, E-mail: mkirby@imaging.robarts.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); Department of Medical Biophysics, University of Western Ontario, London (Canada); Etemad-Rezai, Roya, E-mail: Roya.EtemadRezai@lhsc.on.ca [Department of Medical Imaging, University of Western Ontario (Canada); Wheatley, Andrew, E-mail: awheat@imaging.robarts.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); McCormack, David G., E-mail: David.McCormack@lhsc.on.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); Division of Respirology, Department of Medicine, University of Western Ontario, London (Canada); Lawson Health Research Institute, London (Canada); Parraga, Grace, E-mail: gep@imaging.robarts.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); Department of Medical Biophysics, University of Western Ontario, London (Canada); Department of Medical Imaging, University of Western Ontario (Canada); Lawson Health Research Institute, London (Canada)

    2011-07-15

    Rationale and objectives: Emphysema and small airway obstruction are the pathological hallmarks of chronic obstructive pulmonary disease (COPD). The aim of this pilot study in a small group of chronic obstructive pulmonary disease (COPD) patients was to quantify hyperpolarized helium-3 ({sup 3}He) magnetic resonance imaging (MRI) functional and structural measurements and to explore the potential role for {sup 3}He MRI in detecting the lung structural and functional COPD phenotypes. Materials and methods: We evaluated 20 ex-smokers with stage I (n = 1), stage II (n = 9) and stage III COPD (n = 10). All subjects underwent same-day plethysmography, spirometry, {sup 1}H MRI and hyperpolarized {sup 3}He MRI at 3.0 T. {sup 3}He ventilation defect percent (VDP) was generated from {sup 3}He static ventilation images and {sup 1}H thoracic images and the {sup 3}He apparent diffusion coefficient (ADC) was derived from diffusion-weighted MRI. Results: Based on the relative contribution of normalized ADC and VDP, there was evidence of a predominant {sup 3}He MRI measurement in seven patients (n = 3 mainly ventilation defects or VDP dominant (VD), n = 4 mainly increased ADC or ADC dominant (AD)). Analysis of variance (ANOVA) showed significantly lower ADC for subjects with predominantly elevated VDP (p = 0.02 compared to subjects with predominantly elevated ADC; p = 0.008 compared to mixed group) and significantly decreased VDP for subjects with predominantly elevated ADC (p = 0.003, compared to mixed group). Conclusion: In this small pilot study, a preliminary analysis shows the potential for {sup 3}He MRI to categorize or phenotype COPD ex-smokers, providing good evidence of feasibility for larger prospective studies.

  15. 伴颈动脉狭窄的腔隙性脑梗死患者介入治疗术后的认知变化%Cognitive changes in patients with lacunar cerebral infarction and carotid stenosis after artery intervention therapy

    Institute of Scientific and Technical Information of China (English)

    赵雄飞; 赵志茹; 徐家萍; 张芮娟; 霍秀利; 王玉; 宋霄; 王拥军

    2016-01-01

    Objective To analyze the cognitive changes and influencing factors in patients with lacunar cerebral infarction after carotid artery intervention therapy. Methods Sixty lacunar cerebral infarction combined with carotid stenosis patients treated with artery intervention therapy (intervention therapy group) and 68 lacunar cerebral infarction without carotid stenosis patients treated with drug therapy (drug therapy group) were selected. The neuropsychological test was completed at entry and 1, 6, 12 months after entry, and the results were compared with 60 healthy controls (control group). The cognitive changes were observed. The neuropsychological test included mini mental state examination (MMSE), Montreal cognitive assessment scale (MoCA) and cognitive field test. Results There were statistical differences in other scores except the Stroop test C section and Wechsler adult intelligence scale (WAIS-RC) picture arrangement subtest at entry in intervention therapy group and drug therapy group compared with control group (P0.05). In intervention therapy group, the MMSE scores, MoCA total score, Rey-Osterrieth complex figure test (ROCFT), auditory verb learning test (AVLT), and the WAIS-RC picture arrangement subtest, verbal fluency test, WAIS-RC digit span backwards subtest of performing function 12 months after entry were significantly better than those at entry, and there were statistical differences (P0.05);the MMSE score, MoCA total score, ROCFT, the immediate recall, long-time delayed recall and short delayed recall of AVLT, WAIS-RC picture arrangement subtest, verbal fluency test, WAIS-RC digit span backwards subtest of performing function and digit span backwards subtest of WAIS-RC 12 months after entry were significantly better than those at entry, and there were statistical differences (P0.05). In patients intervention therapy group, Logistic regression analysis showed that the MoCA score was related with age, hypertension and low education level (P0

  16. Correlation analysis between the carotid artery atherosclerosis severity of patientswith lacunar infarct and the level of serum uric acid, high - sensitivity C - reactiveprotein%血清尿酸、超敏C-反应蛋白与腔隙性脑梗死患者颈动脉粥样硬化程度的相关分析

    Institute of Scientific and Technical Information of China (English)

    王姝

    2013-01-01

    Background Nowadays, clinical practice shows that the number of patients with cerebral infarction increases year by year in young and middle-aged adults with unclear causes. This paper aims to investigate the correlation between the level of serum uric acid (UA), high - sensitivity C-reactive protein (hsCRP) and the degree of carotid atherosclerosis by detecting the level of UA, hsCRP and carotid intima-media thickness (IMT) in young and middle-aged patients with lacunar infarct. Methods By using Holland Philips HT-11 color Doppler ultrasonic diagnostic apparatus with linear type probe and 7.50 MHz frequency, IMT of end - diastolic distal and bifurcation of arteria carotis communis and proximal internal carotid artery were measured respectively on 186 patients with definitely diagnosed lacunar infarct. As a result, average values were taken as the IMT values. IMT < 1.00 mm was regarded as negative result and 1.00 mm ≤ IMT < 1.20 mm was thickening of carotid artery intima. Carotid artery plaque formation was regarded with echo structure existing in the lumen or abnormal blood flow deficits into the lumen, or local IMT ≥ 1.20 mm at vertical and horizontal scan. At the same time, the levels of UA and hsCRP were detected, and correlation analysis was made between them and IMT. Results The values of UA, hsCRP and IMT in the case group were higher than that in the control group (P = 0.000). The differences among the case subgroups including IMT thickening group, plaque formation group and IMT normal group were statistically significant (P<0.01, for all). There was linear correlation between the levels of UA, hsCRP and IMT (r = 0.923, P = 0.000; r = 0.955, P = 0.008). Conclusion UA and hsCRP involve in the formation of atherosclerosis plaque and play an important role in the first - onset lacunar infarct patients without hypertension and other risk factors.%研究背景 中青年脑梗死患者呈逐年增加趋势,病因尚不明确.通过对中青年腔隙性脑梗

  17. 吡拉西坦联合丁苯酞软胶囊治疗腔隙性脑梗死合并血管性认知功能障碍观察%Clinical Observation of Piracetam Combined with Butylphthalide Soft Capsules in the Treatment of Patients with Lacunar Infarction Complicated with Vascular Cognitive Impairment

    Institute of Scientific and Technical Information of China (English)

    周幼峰

    2016-01-01

    Objective:To observe the clinical efficacy and safety of piracetam tablets combined with butylphthalide soft capsules in the treatment of patients with lacunar infarction(LI) complicated with vascular cognitive impairment(VCI). Methods:Totally 87 cases of patients with LI and VCI were selected and randomly divided into the control group(44 cases)and the treatment group(43 cases). The control group was only treated with piracetam tablets(1. 2 g,tid),while the treatment group was treated with piracetam tablets(1. 2 g,tid)and butylphthalide soft capsules(0. 2 g,qid),and the treatment course was 30 days. The changes of MMSE score,serum of SOD level and adverse drug reactions were observed and compared in the two groups. Results:Compared with those before the treatment,the mini-mental state examination(MMSE)score and serum level of SOD of the two groups were increased(P < 0. 01)after the treatment,and the increase in the treatment group was more notable than that in the control group(P < 0. 01and P < 0. 05). The effective rate of the treatment group was 86. 05% ,which was higher than that of the control group(75. 00% ,P < 0. 05). Conclusion:Piracetam combined with butylphthalide soft capsules can effectively improve the cognitive impairment of the patients with LI and VCI,and the effect may be related with increasing the level of SOD.%目的:观察吡啦西坦片联合丁苯酞软胶囊治疗腔隙性脑梗死(LI)合并血管性认知功能障碍(VCI)的临床疗效及安全性。方法:87例 LI 合并 VCI 患者随机分为对照组(44例)和观察组(43例)。对照组单用吡拉西坦片(1.2 g tid),观察组联用吡拉西坦片(1.2 g tid)和丁苯酞软胶囊(0.2 g qid),疗程均为30 d。观察两组患者 MMSE 积分、SOD 含量变化,比较两组疗效和药品不良反应。结果:两组患者治疗后 MMSE 积分、血清 SOD 水平均较前升高(P <0.01),且观察组优于对照组(P <0.05和 P

  18. 比较简易精神状态量表与蒙特利尔认知评估量表在腔隙性脑梗死认知障碍患者中的应用价值%Comparison of the Application Value of Mini-mental State Examination and Montreal Cognitive Assessment in Lacunar Infarction Patients with Cognitive Impairment

    Institute of Scientific and Technical Information of China (English)

    肖桂荣; 孙新芳; 章燕幸; 赵宏军; 桂小红

    2012-01-01

    Objective To compare the application value of mini-mental state examination (MMSE) and Montreal cognitive assessment (MoCA) in detecting cognitive impairment in lacunar infarction (LI) patients. Methods The LI patients were first screened by MMSE,and those having a normal education-adjusted score were further assessed by MoCA (26 as the cut-off score). The patients with MoCA score less than 26 were selected into cognitive impaired Ii-CI group and the patients with more than 26 were classified as normal control LJ-NC group. Fifty healthy individuals were recruited in the healthy control group (NC group). The total score and the score of each cognitive field of MoCA among three groups was compared and analyzed. Results 53% (50/94) LI patients with normal MMSE had MoCA < 26. There was a statistical significant difference (P < 0.01) of the cognitive function between these cases and patients with MoCA = 26. The MoCA score of LI-CI group was less than li-NC group in visuospatial, executive, naming, delayed recall, abstraction and so on. The differences were statistical significant (P < 0.05). Conclusion The cognitive impairment of those patients with normal MMSE score but abnormal MoCA score were mainly in visuospatial, executive, naming, delayed recall, abstraction and so on. MoCA is more sensitive than MMSE in cognitive impairment screening in LI patients.%目的 比较简易精神状态(MMSE)量表与蒙特利尔认知评估(MoCA)量表(中文版)在腔隙性脑梗死患者认知障碍评估中的应用价值.方法 首先采用中文版MMSE量表对确诊为腔隙性脑梗死的患者进行筛选,然后对经过受教育程度矫正后MMSE得分正常的患者采用中文版MoCA量表进行评分.MoCA<26分者纳入腔隙性脑梗死认知功能障碍(LI-CI)组,MoCA≥26分者纳入腔隙性脑梗死认知功能正常( LI-NC)组,另选50例健康体检者作为对照(NC)组.比较3组患者MoCA总分及各个认知领域的得分情况.结果 MMSE

  19. Application Value of Montreal Cognitive Assessment in Lacunar Infarction Patients with Cognitive Impairment%蒙特利尔认知评估量表对腔隙性脑梗死患者认知功能障碍的评估价值研究

    Institute of Scientific and Technical Information of China (English)

    肖桂荣; 孙新芳; 章燕幸; 赵宏军; 桂小红

    2012-01-01

    目的 探讨蒙特利尔认知评估量表(Montreal Cognitive Assessment,MoCA)(中文版)在腔隙性脑梗死患者认知功能障碍评估中的应用价值.方法 首先采用中文版简易智能状态量表(Mini-Mental State Examination,MMSE)对确诊为腔隙性脑梗死患者进行筛选,然后对经过受教育程度矫正后MMSE得分正常的患者采用中文版MoCA进行评分,使用26分作为分界值.MoCA<26分者纳入腔隙性脑梗死认知功能障碍组(LI-CI组),MoCA≥26分者纳入腔隙性脑梗死认知功能正常组(LI-NC组).比较两组患者MoCA评分、MMSE评分及MoCA各个认知领域得分情况.结果 MMSE得分正常的患者有53%(50/94)MoCA评分<26分,这些患者的认知功能与MoCA评分≥26分的患者比较,差异有统计学意义﹙P<0.01﹚;LI-CI组在视空间功能与执行功能、命名、抽象、延迟回忆认知领域方面得分低于LI-NC组,差异均有统计学意义(P<0.05).结论 MoCA在筛查腔隙性脑梗死患者认知障碍方面可能比MMSE更为敏感,对于MMSE评分正常MoCA评测异常的患者认知损害主要表现在视空间与执行功能、命名、延迟记忆以及抽象等方面.%Objective To analyze the application value of Montreal Cognitive Assessment (MoCA) ( Chinese version ) in detecting cognitive impairment in patients with lacunar infarction (LI). Methods The patients confirmed with LI were first screened by Mini - Mental State Examination ( MMSE) , and patients having normal MMSE score were further assessed by MoCA after education adjustment (26 as the cut - off score). The patients with MoCA score less than 26 were selected as cognitive im-paired LI - CI group and the patients with more than 26 were selected as normal control LI - NC group. MoCA score, MMSE score and scores of each cognitive field of MoCA were compared between the two groups. Results 53% (50/94) Li patients with nor-mal MMSE score had MoCA socre < 26, and these patients' cognitive function

  20. Effects of Alpha-lipoic Acid on Congnitive Function in Lacunar Infarction Patients with Diabetes Mellitu%α-硫辛酸对腔隙性脑梗死伴糖尿病患者认知功能的影响

    Institute of Scientific and Technical Information of China (English)

    丛文东; 吴达荣; 曾佳; 高展

    2013-01-01

      目的:观察腔隙性脑梗死伴糖尿病患者的认知功能损害特点,并探讨α‐硫辛酸对其认知功能的影响。方法:伴有糖尿病的腔隙性脑梗死患者60例,随机分配在 A 组(30例,每天静脉使用α‐硫辛酸)和B组(30例,一般治疗)中,对照组(30例)选用健康体检人群。使用蒙特利尔认知评估量表(MOCA)分别对两组患者在发病后3天、3个月进行认知功能评估,并分别与正常对照组进行比较。结果:在脑梗死发病后3天,两组患者均出现视空间与执行功能、命名、延迟记忆、注意力和计算能力、语言、定向功能障碍,总分与对照组相比差异有显著性。在发病后3个月,使用硫辛酸组各项评分较一般治疗组高,总分及注意力、视空间与执行功能、定向力差异有统计学意义。结论:在伴有糖尿病的腔隙性脑梗死患者急性期认知损害广泛,α‐硫辛酸对认知功能具有保护作用。%  Objective:To explore the characters of cognitive dysfunction for lacunar infarction (L I) with diabetes mellitus and the protective effects of alpha‐lipoic acid .Methods :A total of 64 LI patients with dia‐betes mellitus randomly divided into 2 groups .Patients of group 1 (n=30) were treated with alpha ‐lipoic acid .Patients of group 2(n=30) were assigned conventional therapy .The cognitive function of patients were evaluated with Montreal Cognitive Assessment (MOCA) at 3days and 3months after attack .An additional control group consisted of age‐matched healthy (n=30) .Results:Compared with controls ,significant differ‐ence was found on the memory ,name ,language ,orientation ,attention ,executive function ,visuospatial and visuo‐constructive function at 3 days .Most cognitive domains were improved at 3 months of group 1 ,scores of general MoCA ,attention ,visuospatial and visuo‐constructive function and orientation were higher than those of

  1. Color Doppler Ultrasound Study of Glomuvenous Malformations with its Clinical and Histologic Correlations.

    Science.gov (United States)

    Wortsman, X; Millard, F; Aranibar, L

    2017-07-03

    Glomuvenous malformations are hamartomatous lesions characterized by the presence of glomus cells in the vascular smooth muscle. We present the clinical and color Doppler ultrasound features of a series of 13 cases of histologically confirmed glomuvenous malformations. In all cases, the ultrasound study revealed moderately delimited superficial dermal and hypodermal pseudonodular structures of mixed echogenicity, with hypoechoic and heterogeneous areas and anechoic, pseudocystic tubular and lacunar zones. Arterial and venous vessels, mainly with a low flow (≤ 15cm/s) were observed in 85% of patients, but no arteriovenous shunts were present. Deeper structures were not affected and no phleboliths were detected. The clinical and ultrasound findings could facilitate diagnosis, surgical planning, and noninvasive follow-up in these tumors. Copyright © 2017 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. The relationship between the level of plasma fibrinogen and carotid/lower limb atherosclerosis in patients with transient ischemic attack and single/multiple lacunar cerebral infarction%短暂性脑缺血发作、单/多发腔隙性脑梗死患者血纤维蛋白原水平与颈动脉及下肢动脉粥样硬化的相关性研究

    Institute of Scientific and Technical Information of China (English)

    季芳; 罗美芳; 李蕾

    2011-01-01

    目的 探讨短暂性脑缺血发作(transient ischemic attack,TIA)、单/多发腔隙性脑梗死患者颈动脉及下肢动脉粥样硬化情况,明确血纤维蛋白原水平对颈动脉及下肢动脉粥样硬化的影响.方法 对178例短暂性脑缺血发作、单/多发腔隙性脑梗死患者进行颈动脉及下肢动脉彩色多普勒超声检查,记录颈动脉及下肢动脉粥样硬化斑块的部位、大小、数目、回声、动脉分叉处内膜中层厚度(intima-media thickness,IMT)及血管内径,并测量血压及纤维蛋白原测定.结果 颈动脉粥样硬化斑块位于颈总动脉分叉处最多(占58.3%).IMT≥1.2 mm组血纤维蛋白原水平显著高于IMT<1.2 mm组(P<0.05).下肢动脉粥样硬化位于股动脉最多(占49.6%),IMT≥1.2 mm组血纤维蛋白原水平显著高于IMT<1.2 mm组(P<0.05).高水平纤维蛋白原组(≥3.0 g/L)易损斑块数量明显增多(P≤0.05).颈动脉IMT与患者收缩压、舒张压以及纤维蛋白原水平呈正相关(r=4.89、5.37、6.47,P均<0.05),下肢动脉IMT与血糖及纤维蛋白原水平呈正相关(r=4.83、5.38、6.68,P均<0.05).结论 血纤维蛋白原水平与短暂性脑缺血发作、单/多发腔隙性脑梗死患者颈动脉及下肢动脉粥样硬化程度呈正相关.%Objective To analyzes carotid/lower limb atheromatous plaque in patients with transient ischemic attack(TIA)、single/multiple lacunar cerebral infarction and explore the relationship between carotid/lower limb atherosclerosis and the levels of plasma fibrinogen.Methods In one hundred and seventy-eight cases of TIA or single/multiple lacunar cerebral infarction, the location, size, number, nature of carotid/lower limb atheromatous plaque, diameter of artety and intima-media thickness (IMT)of bifurcation of common carotid artery were assessed by Doppler ultrasonography, and other related indexes, such as blood pressure and the level of plasma fibirinogen were also evaluated.Results The carotid

  3. Reconstruction of the limbal vasculature after limbal-conjunctival autograft transplantation in pterygium surgery: an angiography study.

    Science.gov (United States)

    Kim, Yong Joon; Yoo, Seung Hoon; Chung, Jin Kwon

    2014-11-18

    We evaluated the angiographic features of the affected limbus in patients with pterygia and assessed limbal reconstruction outcomes after limbal-conjunctival autograft (LCA) transplantation in terms of vascular remodeling. We studied prospectively 31 eyes of 31 patients who underwent pterygium excision and LCA transplantation; 28 eyes of 28 normal participants served as controls. Anterior segment indocyanine green angiography (ICGA) was performed for each participant preoperatively and at 1 week, and 1 and 3 months postoperatively. The perioperative angiographic features of the pterygium were compared to those in normal eyes. The structural changes of the marginal corneal vascular arcades (MCAs) and LCA were quantitatively assessed postoperatively in terms of vascular density and lacunarity. Deteriorated MCAs that extended beyond the pterygium head were observed in the pterygium group. The pterygium had a dual blood supply from the conjunctival and episcleral circulations. In terms of limbal reconstruction, the engorged reperfusion vessels arose from the adjacent episcleral vessels along the limbus at 1 week postoperatively. The reconstructed MCAs had begun to appear at 1 month postoperatively and became apparent 3 months postoperatively in 26 (83.9%) of 31 eyes of the pterygium group, resulting in a successful clinical outcome. Higher vascular density and lower lacunarity were measured in the limbus and the graft at 3 months than at 1 month (P < 0.001 for all), which indicated fine reorganization of the reconstructed vessels. The pterygium had a dual blood supply, and the remodeling of the affected limbus and LCA continued up to 3 months postoperatively. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  4. Dietary intake of saturated fatty acids and incident stroke and coronary heart disease in Japanese communities: the JPHC Study.

    Science.gov (United States)

    Yamagishi, Kazumasa; Iso, Hiroyasu; Kokubo, Yoshihiro; Saito, Isao; Yatsuya, Hiroshi; Ishihara, Junko; Inoue, Manami; Tsugane, Shoichiro

    2013-04-01

    Aims Although dietary saturated fatty acids (SFA) are considered atherogenic, associations between SFAs intake and stroke and coronary heart disease are still debated. We sought to test the hypothesis that SFA intake is associated inversely with risk of stroke and its subtypes and positively with coronary heart disease among Japanese, whose average SFA intake is lower than that of Westerners. Methods and results The Japan Public Health Center-based prospective Study involves two subcohorts: Cohort I, aged 45-64 in 1995 and followed-up through 2009, and Cohort II, aged 45-74 in 1998 and followed-up through 2007. A total of 38 084 men and 43 847 women were included in this report. Hazards ratios for incident total stroke, ischaemic stroke, intraparhenchymal haemorrhage, subarachnoid haemorrhage, myocardial infarction, and sudden cardiac death across quintiles of dietary SFAs were examined. We found inverse associations between SFA intake and total stroke [multivariable hazard ratio (95% confidence interval) for the highest vs. lowest quintiles = 0.77 (0.65-0.93), trend P = 0.002], intraparenchymal haemorrhage [0.61 (0.43-0.86), P for trend = 0.005], and ischaemic stroke [0.84 (0.67-1.06), trend P = 0.08], primarily for deep intraparenchymal haemorrhage [0.67 (0.45-0.99), P for trend = 0.04] and lacunar infarction [0.75 (0.53, 1.07), trend P = 0.02]. We also observed a positive association between SFAs intake and myocardial infarction [1.39 (0.93-2.08), trend P = 0.046] primarily among men. No associations were observed between SFAs intake and incidence of subarachnoid haemorrhage or sudden cardiac death. Conclusions In this Japanese population, SFAs intake was inversely associated with deep intraparenchymal haemorrhage and lacunar infarction and positively associated with myocardial infarction.

  5. Using Fractal Analysis in Modeling the Dynamics of Forest Areas and Economic Impact Assessment: Maramureș County, Romania, as a Case Study

    National Research Council Canada - National Science Library

    Pintilii, Radu-Daniel; Andronache, Ion; Diaconu, Daniel; Dobrea, Răzvan; Zeleňáková, Martina; Fensholt, Rasmus; Peptenatu, Daniel; Drăghici, Cristian-Constantin; Ciobotaru, Ana-Maria

    2017-01-01

    .... The Fractal Fragmentation Index (FFI) and Fixed Grid 2D Lacunarity (FG2DL) were used to quantify the degree of fragmentation and dispersion of the forested areas, and thereby the extent to which a forest area is affected...

  6. The contribution of twins to the study of cognitive ageing and dementia: the Older Australian Twins Study.

    Science.gov (United States)

    Sachdev, Perminder S; Lee, Teresa; Wen, Wei; Ames, David; Batouli, Amir H; Bowden, Jocelyn; Brodaty, Henry; Chong, Elizabeth; Crawford, John; Kang, Kristan; Mather, Karen; Lammel, Andrea; Slavin, Melissa J; Thalamuthu, Anbupalam; Trollor, Julian; Wright, Margie J

    2013-12-01

    The Older Australian Twins Study (OATS) is a major longitudinal study of twins, aged ≥ 65 years, to investigate genetic and environmental factors and their interactions in healthy brain ageing and neurocognitive disorders. The study collects psychiatric, neuropsychological, cardiovascular, metabolic, biochemical, neuroimaging, genomic and proteomic data, with two-yearly assessments, and is currently in its third wave. The initial cohort comprises 623 individuals (161 monozygotic and 124 dizygotic twin pairs; 1 MZ triplets; 27 single twins and 23 non-twin siblings), of whom 426 have had wave 2 assessment. A number of salient findings have emerged thus far which assist in the understanding of genetic contributions to cognitive functions such as processing speed, executive ability and episodic memory, and which support the brain reserve hypothesis. The heritability of brain structures, both cortical and subcortical, brain spectroscopic metabolites and markers of small vessel disease, such as lacunar infarction and white matter hyperintensities, have been examined and can inform future genetic investigations. Work on amyloid imaging and functional magnetic resonance imaging is proceeding and epigenetic studies are progressing. This internationally important study has the potential to inform research into cognitive ageing in the future, and offers an excellent resource for collaborative work.

  7. Stroke in Kuwait: a three-year prospective study.

    Science.gov (United States)

    Abdul-Ghaffar, N U; el-Sonbaty, M R; el-Din Abdul-Baky, M S; Marafie, A A; al-Said, A M

    1997-01-01

    To study the pattern of stroke in Kuwait, prospective data were collected from all patients admitted with first-ever stroke to our hospital over 3 years: 1989, 1992 and 1993. The primary-care registry over the same period was examined to ascertain that all cases of stroke seen by the primary-care doctors were referred to a hospital. Death certificates issued for people who died outside the hospital were also examined. The study included: clinical evaluation, computed tomography, electrocardiography, blood laboratories, serum chemistry and other investigations as required. The overall annual crude incidence rate was 27.6/100,000 population. The age-adjusted annual crude incidence rate was 145.6/100,000 population. No seasonal variation in the stroke incidence was observed in our study. Carotid-territory large infarction represented 46.5% of all strokes followed by intracerebral haemorrhage in 19.9%, lacunar infarction in 17%, basilar infarction in 8.3% and subarachnoid haemorrhage in 1.7%. The overall case fatality rate was 10%. Mortality increased with age and when loss of consciousness was present. The study demonstrated that stroke incidence in Kuwait is very low due to the young average age of the Kuwaiti population.

  8. Pattern of hospitalized-stroke patients in ASEAN countries an ASNA stroke epidemiological study

    Directory of Open Access Journals (Sweden)

    Jusuf Misbach

    2001-03-01

    Full Text Available To better understanding the demographic characteristics, admission time, clinical pattern, risk factors, stroke type, length of stay, and discharge outcome of hospitalized acute stroke patients in ASEAN member countries, ASEAN   Neurological Association (ASNA formed a Standing Commiltee for Stroke in 1996 and this is the first ASNA Stroke Epidemiological Study using the same stroke protocol. This prospective hospital based study was conducted in seven ASEAN countries (Brunei, Indonesia, Malaysia, Philippines, Singapore, Thailand, and Vietnam by participating neurologists from October 1996 to March 1997. Of the 3723 consecutive hospitalized stroke patients (2030 males and 1660 females from 44 participating hospitals in this study ie Brunei (n=53, Indonesia (n=2065, Malaysia (n=300,Philippines (n=545,Singapore (n=232, Thailand (n=244 and Vietnam (n=284, the mean age was 59.0 ± 13,8 years 16% of patients were younger than 45 years and 37% of patients were older than 65 years. There were no significant differences in age at onset among stroke subjects except in Vietnam (younger and Singapore (older. The sex distribution showed a slight higher prevalence of women in Singapore and in the age group > 64 years. The mean adrnission time was 41.5 ± 87.0 hours, 19% of patients were admitted within 3 hours, 29% within 6 hours and 66% more than 6 hours (delayed admission especially in Malaysia and Singapore (80% and 77% respectively. Motor disability was the most prevalent clinical feature in all countries and carotid bruit was the rarest (1%. Hypertension was the most common risk factor (68% in all countries, followed by TIA (35%, smoking, diabetes mellitus, ischnemic heart disease and hypercholesterolemia. CT scan was performed on 76% of subjects. The diagnostic classification was non lacunar anterior circulation (32%, lacunar infarction (14%, hemorrhagic stroke (26%, SAH (4%. Mean length of stay was 11.4 ± 11.8 days. Most of the patients

  9. In-hospital cerebrovascular complications following orthotopic liver transplantation: A retrospective study

    Directory of Open Access Journals (Sweden)

    Liang Zhijian

    2008-12-01

    Full Text Available Abstract Background Cerebrovascular complications are severe events following orthotopic liver transplantation (OLT. This study aimed to observe the clinical and neuroimaging features and possible risk factors of in-hospital cerebrovascular complications in the patients who underwent OLT. Patients and methods We retrospectively reviewed 337 consecutive patients who underwent 358 OLTs. Cerebrovascular complications were determined by clinical and neuroimaging manifestations, and the possible risk factors were analyzed in the patients with intracranial hemorrhage. Results Ten of 337 (3.0% patients developed in-hospital cerebrovascular complications (8 cases experienced intracranial hemorrhage and 2 cases had cerebral infarction, and 6 of them died. The clinical presentations were similar to common stroke, but with rapid deterioration at early stage. The hematomas on brain CT scan were massive, irregular, multifocal and diffuse, and most of them were located at brain lobes and might enlarge or rebleed. Infarcts presented lacunar and multifocal lesions in basal gangliar but with possible hemorrhagic transformation. The patients with intracranial hemorrhage had older age and a more frequency of systemic infection than non-intracranial hemorrhage patients. (P = 0.011 and 0.029, respectively. Conclusion Posttransplant cerebrovascular complications have severe impact on outcome of the patients who received OLT. Older age and systemic infection may be the possible risk factors of in-hospital intracranial hemorrhage following OLT.

  10. [Cerebral vasoreactivity and functional response in stroke: a study with functional MR].

    Science.gov (United States)

    Piñeiro, R; Matthews, P M

    Lacunar infarcts are usually associated with anatomical and possibly functional changes in the walls of small blood vessels (penetrating arteries). The functional effect varies and is accompanied by cerebral adaptive/reorganizational changes. BOLD contrast, originated in the microvasculature (especially with ultra high magnetic fields) depends, in the end, on haemodynamic changes and is useful for exploring patterns of cerebral activation using fMR. To compare the temporal behaviour of the BOLD signal and the distribution of activation between a group of patients with no functional sequelae following a stroke and a control group, by using fMR at 3T. The stroke group showed a smaller number of voxels activated, but this was not statistically significant. The patterns of activation, size of the sensor motor area (SM or ASM) and index of laterality were similar in both groups. In SM the BOLD response was 85% slower (pstroke group, which were insufficient to produce reorganizational/adaptive changes or by the great variety of responses. The temporal response of the BOLD response was different in the stroke group, probably as a result of the alteration in the haemodynamic response in relation to the underlying processes which damage the functional properties of the vascular wall. This difference in the BOLD response should be interpreted with caution, and borne in mind when interpreting activation in persons with vascular pathology. Further studies are necessary for better understanding of its significance.

  11. Studying neutral hydrogen structures during the epoch of reionization using fractal dimensions

    CERN Document Server

    Bandyopadhyay, Bidisha; Seshadri, T R

    2016-01-01

    Fractal dimensions can be used to characterize the clustering and lacunarities in density distributions. We use generalized fractal dimensions to study the neutral hydrogen distribution (HI) during the epoch of reionization. Using a semi-numeric model of ionized bubbles to generate the HI field, we calculate the fractal dimensions for length scales $\\sim 10 h^{-1}$ cMpc. We find that the HI field displays significant multifractal behaviour and is not consistent with homogeneity at these scales when the mass averaged neutral fraction $\\bar{x}_{\\rm HI}^M \\gtrsim 0.5$. This multifractal nature is driven entirely by the shapes and distribution of the ionized regions. The sensitivity of the fractal dimension to the neutral fraction implies that it can be used for constraining reionization history. We find that the fractal dimension is relatively less sensitive to the value of the minimum mass of ionizing haloes when it is in the range $\\sim 10^9 - 10^{10} h^{-1} M_{\\odot}$. Interestingly, the fractal dimension is ...

  12. [A prospective study for systemic inflammatory response syndrome (SIRS) after cerebral infarction].

    Science.gov (United States)

    Xue, Yuan-yuan; Xu, Xiao-yun; Li, Gang; Wang, Yue

    2008-12-01

    To investigate whether systemic inflammatory response syndrome (SIRS) after cerebral infarction is associated with poor outcome and its associated clinical factors. We prospectively studied 500 patients with cerebral infarction, recorded the associated clinical factors on presentation and calculated the mortality at 21st day. There are 85 SIRS patients in 500 patients with cerebral infarction, 31 with total anterior cerebral infarction (TACI), 34 with partial anterior cerebral infarction (PACI), 15 with posterior cerebral infarction (POCI) and 5 with lacunar cerebral infarction (LACI). The frequency of SIRS was positively correlated with mortality rate according to Oxfordshire Community Stroke Project (OCSP) subtypes in cerebral infarction patients with fever (Spearman correlation coefficient = 1.0; P SIRS and mortality of cerebral infarction were as follows: age, infection, 48 h Chinese Stroke Scale score, 48 h Glasgow score, OCSP subtypes and dysphagia. Diabetes was the risk factor for SIRS, but had no effect on mortality. On Cox regression, 48 h Glasgow score was the sole independent risk factor of outcome. However, if SIRS was included in the formula, P > 0.05. SIRS is the predictor of poor outcome after acute cerebral infarction. It is important to prevent SIRS especially in TACI and POCI. Diabetes is the risk factor for SIRS, but has no effect on mortality.

  13. The 'silence' of silent brain infarctions may be related to chronic ischemic preconditioning and nonstrategic locations rather than to a small infarction size.

    Science.gov (United States)

    Feng, Chao; Bai, Xue; Xu, Yu; Hua, Ting; Liu, Xue-Yuan

    2013-01-01

    Silent brain infarctions are the silent cerebrovascular events that are distinguished from symptomatic lacunar infarctions by their 'silence'; the origin of these infarctions is still unclear. This study analyzed the characteristics of silent and symptomatic lacunar infarctions and sought to explore the mechanism of this 'silence'. In total, 156 patients with only silent brain infarctions, 90 with only symptomatic lacunar infarctions, 160 with both silent and symptomatic lacunar infarctions, and 115 without any infarctions were recruited. Vascular risk factors, leukoaraiosis, and vascular assessment results were compared. The National Institutes of Health Stroke Scale scores were compared between patients with only symptomatic lacunar infarctions and patients with two types of infarctions. The locations of all of the infarctions were evaluated. The evolution of the two types of infarctions was retrospectively studied by comparing the infarcts on the magnetic resonance images of 63 patients obtained at different times. The main risk factors for silent brain infarctions were hypertension, age, and advanced leukoaraiosis; the main factors for symptomatic lacunar infarctions were hypertension, atrial fibrillation, and atherosclerosis of relevant arteries. The neurological deficits of patients with only symptomatic lacunar infarctions were more severe than those of patients with both types of infarctions. More silent brain infarctions were located in the corona radiata and basal ganglia; these locations were different from those of the symptomatic lacunar infarctions. The initial sizes of the symptomatic lacunar infarctions were larger than the silent brain infarctions, whereas the final sizes were almost equal between the two groups. Chronic ischemic preconditioning and nonstrategic locations may be the main reasons for the 'silence' of silent brain infarctions.

  14. The 'silence' of silent brain infarctions may be related to chronic ischemic preconditioning and nonstrategic locations rather than to a small infarction size

    Directory of Open Access Journals (Sweden)

    Chao Feng

    2013-01-01

    Full Text Available OBJECTIVE: Silent brain infarctions are the silent cerebrovascular events that are distinguished from symptomatic lacunar infarctions by their 'silence'; the origin of these infarctions is still unclear. This study analyzed the characteristics of silent and symptomatic lacunar infarctions and sought to explore the mechanism of this 'silence'. METHODS: In total, 156 patients with only silent brain infarctions, 90 with only symptomatic lacunar infarctions, 160 with both silent and symptomatic lacunar infarctions, and 115 without any infarctions were recruited. Vascular risk factors, leukoaraiosis, and vascular assessment results were compared. The National Institutes of Health Stroke Scale scores were compared between patients with only symptomatic lacunar infarctions and patients with two types of infarctions. The locations of all of the infarctions were evaluated. The evolution of the two types of infarctions was retrospectively studied by comparing the infarcts on the magnetic resonance images of 63 patients obtained at different times. RESULTS: The main risk factors for silent brain infarctions were hypertension, age, and advanced leukoaraiosis; the main factors for symptomatic lacunar infarctions were hypertension, atrial fibrillation, and atherosclerosis of relevant arteries. The neurological deficits of patients with only symptomatic lacunar infarctions were more severe than those of patients with both types of infarctions. More silent brain infarctions were located in the corona radiata and basal ganglia; these locations were different from those of the symptomatic lacunar infarctions. The initial sizes of the symptomatic lacunar infarctions were larger than the silent brain infarctions, whereas the final sizes were almost equal between the two groups. CONCLUSIONS: Chronic ischemic preconditioning and nonstrategic locations may be the main reasons for the 'silence' of silent brain infarctions.

  15. SEMIAUTOMATED QUANTITATIVE APPROACH TO CHARACTERIZE TREATMENT RESPONSE IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION: A Real-World Study.

    Science.gov (United States)

    Roberts, Philipp K; Nesper, Peter L; Gill, Manjot K; Fawzi, Amani A

    2017-08-01

    To perform a quantitative study of the vascular microstructure in actively treated choroidal neovascularization by optical coherence tomographic angiography. Patients undergoing individualized anti-vascular endothelial growth factor therapy of minimum 12 months duration were included in this cross-sectional observational study and imaged using optical coherence tomographic angiography. En face optical coherence tomographic angiography images were analyzed for quantitative features, such as junction density, vessel length, and lacunarity using validated software (Angiotool). Patients were divided into 2 groups depending on their individualized treatment interval: "good responders, treated less frequently than 6 weeks" versus "poor responders, treated every 6 weeks or more frequently." Nonparametric testing was used to assess differences between these groups. Twenty-five eyes of 23 consecutive patients with a median 58-month history of choroidal neovascularization, treated by median of 34 anti-vascular endothelial growth factor injections, were included in the analysis. There was no significant difference between any of the microvascular choroidal neovascularization features between the 2 groups (P > 0.05). The semiautomated vessel segmentation software provides an objective and quantitative approach for choroidal neovascularization characterization. The consistently nonsignificant outcomes between the groups may provide evidence to support the "normalization hypothesis." This would suggest that regardless of treatment interval, individualized therapy in these eyes established vessel stability.

  16. Characteristics of alveolar bone associated with physiological movement of molar in mice: a histological and histochemical study.

    Science.gov (United States)

    Matsuda, Kie; Haga-Tsujimura, Maiko; Yoshie, Sumio; Shimomura-Kuroki, Junko

    2014-01-01

    Mouse molars undergo distal movement, during which new bone is formed at the mesial side of the tooth root whereas the preexisting bone is resorbed at the distal side of the root. However, there is little detailed information available regarding which of the bones that surround the tooth root are involved in physiological tooth movement. In the present study, we therefore aimed to investigate the precise morphological differences of the alveolar bone between the bone formation side of the tooth root, using routine histological procedures including silver impregnation, as well as by immunohistochemical analysis of alkaline phosphatase and tartrate-resistant acid phosphatase activity, and immunohistochemical analysis of the expression of the osteocyte markers dentin matrix protein 1, sclerostin, and fibroblast growth factor 23. Histochemical analysis indicated that bone formation by osteoblasts and bone resorption by osteoclasts occurred at the bone formation side and the bone resorption side, respectively. Osteocyte marker immunoreactivity of osteocytes at the surface of the bone close to the periodontal ligament differed at the bone formation and bone resorption sides. We also showed different specific features of osteocytic lacunar canalicular systems at the bone formation and bone resorption sides by using silver staining. This study suggests that the alveolar bone is different in the osteocyte nature between the bone formation side and the bone resorption side due to physiological distal movement of the mouse molar.

  17. Application of Diffusion Tensor Imaging Parameters to Detect Change in Longitudinal Studies in Cerebral Small Vessel Disease.

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    Eva Anna Zeestraten

    Full Text Available Cerebral small vessel disease (SVD is the major cause of vascular cognitive impairment, resulting in significant disability and reduced quality of life. Cognitive tests have been shown to be insensitive to change in longitudinal studies and, therefore, sensitive surrogate markers are needed to monitor disease progression and assess treatment effects in clinical trials. Diffusion tensor imaging (DTI is thought to offer great potential in this regard. Sensitivity of the various parameters that can be derived from DTI is however unknown. We aimed to evaluate the differential sensitivity of DTI markers to detect SVD progression, and to estimate sample sizes required to assess therapeutic interventions aimed at halting decline based on DTI data. We investigated 99 patients with symptomatic SVD, defined as clinical lacunar syndrome with MRI confirmation of a corresponding infarct as well as confluent white matter hyperintensities over a 3 year follow-up period. We evaluated change in DTI histogram parameters using linear mixed effect models and calculated sample size estimates. Over a three-year follow-up period we observed a decline in fractional anisotropy and increase in diffusivity in white matter tissue and most parameters changed significantly. Mean diffusivity peak height was the most sensitive marker for SVD progression as it had the smallest sample size estimate. This suggests disease progression can be monitored sensitively using DTI histogram analysis and confirms DTI's potential as surrogate marker for SVD.

  18. Causes of cerebral small vessel disease : a prospective population-based MRI study

    NARCIS (Netherlands)

    E.J. van Dijk (Ewoud)

    2004-01-01

    markdownabstract__Abstract__ In the 1970s, the introduction of computed tomography (CT) and magnetic resonance imaging (MRI) in medicine, made it possible to image the living brain. These images showed that cerebral white matter lesions and asymptomatic lacunar brain infarcts are extremely common i

  19. Significance of Haemodynamic and Haemostatic Factors in the Course of Different Manifestations of Cerebral Small Vessel Disease: The SHEF-CSVD Study—Study Rationale and Protocol

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    Jacek Staszewski

    2013-01-01

    Full Text Available Rationale. This paper describes the rationale and design of the SHEF-CSVD Study, which aims to determine the long-term clinical and radiological course of cerebral small vessel disease (CSVD and to evaluate haemostatic and haemodynamic prognostic factors of the condition. Design. This single-centre, prospective, non-interventional cohort study will follow 150 consecutive patients with different clinical manifestations of CSVD (lacunar ischaemic stroke, vascular dementia, vascular parkinsonism or spontaneous deep, intracerebral haemorrhage and 50 age- and sex-matched controls over a period of 24 months. The clinical and radiological course will be evaluated basing on a detailed neurological, neuropsychological and MRI examinations. Haemodynamic (cerebral vasoreactivity, 24 h blood pressure control and haemostatic factors (markers of endothelial and platelet dysfunction, brachial artery flow-mediated dilatation test will be determined. Discussion. The scheduled study will specifically address the issue of haemodynamic and haemostatic prognostic factors and their course over time in various clinical manifestations of CSVD. The findings may aid the development of prophylactic strategies and individualised treatment plans, which are critical during the early stages of the disease.

  20. LACUNAR CONSTRUCTIONS “NOUN+ARTICLE” IN PUBLICIST-ORAL SPEECH OF ENGLISH AND GREEK

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    Fomenko L. N.

    2015-04-01

    Full Text Available This article describes some interesting facts of Modern English and Greek Grammar and pay our attention to extension of constructions “noun + article” without article in publicist-oral speech, where it should be. Our observations show some phenomena of evolution of system “noun + article”. This article is due to some cases of using articles, which we can’t often find in traditional native and foreign normal grammars. In English Grammar the ellipsis of article meets stylistic and syntax’s requirements. But there isn’t such limitation in Greek Grammar, that’s why on the one hand, we qualify the ellipsis of article as a realization of category determinacyindeterminacy, and on the other hand, we can see the generalization of the meaning of article. Illustrative materials are newspapers’ articles of classical British dialectical English and Dimotiki (oral New Greek.There are not only main rules of articles in periodical and oral speech, but also the meaning of nouns, which we can understand from surrounding context and geographical position, also as a style of periodical publications

  1. Modelling Applicability of Fractal Analysis to Efficiency of Soil Exploration by Roots

    OpenAIRE

    Walk, Thomas C.; van Erp, Erik; Lynch, Jonathan P.

    2004-01-01

    • Background and Aims Fractal analysis allows calculation of fractal dimension, fractal abundance and lacunarity. Fractal analysis of plant roots has revealed correlations of fractal dimension with age, topology or genotypic variation, while fractal abundance has been associated with root length. Lacunarity is associated with heterogeneity of distribution, and has yet to be utilized in analysis of roots. In this study, fractal analysis was applied to the study of root architecture and acquisi...

  2. Association of Apolipoprotein E Polymorphism with Ischemic Stroke Subtypes in Taiwan

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    Chiou-Lian Lai

    2007-10-01

    Full Text Available The aim of this study was to clarify whether the apolipoprotein E gene (APOE is related to ischemic stroke subtypes in Taiwan's Chinese population. Using the classification of Cerebrovascular Diseases III, 143 patients with lacunar infarction, 114 patients with atherothrombotic infarction, and 112 healthy controls were enrolled. APOE genotype was determined using polymerase chain reaction. Regarding the distribution of APOE genotypes, the frequency of ϵ3/ϵ4 genotypes in lacunar patients was significantly different from that in control subjects, by logistic regression, using ϵ3/ϵ3 as a reference group. There was no significant difference between atherothrombotic patients and the control group in the distribution of APOE genotypes or alleles. The present finding suggests that there is a probable association between ϵ3/ϵ4 genotype and lacunar infarcts, but not atherothrombotic infarcts. This indicates that genetic factors may play a role, at least partially, in lacunar infarction in Taiwan's Chinese population.

  3. Using DTI to assess white matter microstructure in cerebral small vessel disease (SVD) in multicentre studies.

    Science.gov (United States)

    Croall, Iain D; Lohner, Valerie; Moynihan, Barry; Khan, Usman; Hassan, Ahamad; O'Brien, John T; Morris, Robin G; Tozer, Daniel J; Cambridge, Victoria C; Harkness, Kirsty; Werring, David J; Blamire, Andrew M; Ford, Gary A; Barrick, Thomas R; Markus, Hugh S

    2017-06-01

    Diffusion tensor imaging (DTI) metrics such as fractional anisotropy (FA) and mean diffusivity (MD) have been proposed as clinical trial markers of cerebral small vessel disease (SVD) due to their associations with outcomes such as cognition. However, studies investigating this have been predominantly single-centre. As clinical trials are likely to be multisite, further studies are required to determine whether associations with cognition of similar strengths can be detected in a multicentre setting. One hundred and nine patients (mean age =68 years) with symptomatic lacunar infarction and confluent white matter hyperintensities (WMH) on MRI was recruited across six sites as part of the PRESERVE DTI substudy. After handling missing data, 3T-MRI scanning was available from five sites on five scanner models (Siemens and Philips), alongside neuropsychological and quality of life (QoL) assessments. FA median and MD peak height were extracted from DTI histogram analysis. Multiple linear regressions were performed, including normalized brain volume, WMH lesion load, and n° lacunes as covariates, to investigate the association of FA and MD with cognition and QoL. DTI metrics from all white matter were significantly associated with global cognition (standardized β =0.268), mental flexibility (β =0.306), verbal fluency (β =0.376), and Montreal Cognitive Assessment (MoCA) (β =0.273). The magnitudes of these associations were comparable with those previously reported from single-centre studies found in a systematic literature review. In this multicentre study, we confirmed associations between DTI parameters and cognition, which were similar in strength to those found in previous single-centre studies. The present study supports the use of DTI metrics as biomarkers of disease progression in multicentre studies. © 2017 The Author(s).

  4. Using Fractal Analysis in Modeling the Dynamics of Forest Areas and Economic Impact Assessment: Maramureș County, Romania, as a Case Study

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    Radu-Daniel Pintilii

    2017-01-01

    Full Text Available This study uses fractal analysis to quantify the spatial changes of forest resources caused by an increase of deforested areas. The method introduced contributes to the evaluation of forest resources being under significant pressure from anthropogenic activities. The pressure on the forest resources has been analyzed for Maramureș County, one of the most deforested counties in Romania. In order to evaluate this, the deforested areas were calculated for the period of 2001–2014, by using the Global Forest Change 2000–2014 database. The Fractal Fragmentation Index (FFI and Fixed Grid 2D Lacunarity (FG2DL were used to quantify the degree of fragmentation and dispersion of the forested areas, and thereby the extent to which a forest area is affected by deforestation. The process of quantifying the pressure on forested areas included the creation of a database for the period of 2000–2014 containing economic activities (turnover related to woody recourses, important indicators of forest exploitation. Taken together, the results obtained indicate a dramatic increase in deforested areas (over 19,122 ha in total for the period of analysis, in Maramureș County.

  5. Vascular care in patients with Alzheimer disease with cerebrovascular lesions slows progression of white matter lesions on MRI: the evaluation of vascular care in Alzheimer's disease (EVA) study.

    Science.gov (United States)

    Richard, Edo; Gouw, Alida A; Scheltens, Philip; van Gool, Willem A

    2010-03-01

    White matter lesions (WMLs) and cerebral infarcts are common findings in Alzheimer disease and may contribute to dementia severity. WMLs and lacunar infarcts may provide a potential target for intervention strategies. This study assessed whether multicomponent vascular care in patients with Alzheimer disease with cerebrovascular lesions slows progression of WMLs and prevents occurrence of new infarcts. A randomized controlled clinical trial, including 123 subjects, compared vascular care with standard care in patients with Alzheimer disease with cerebrovascular lesions on MRI. Progression of WMLs, lacunes, medial temporal lobe atrophy, and global cortical atrophy were semiquantitatively scored after 2-year follow-up. Sixty-five subjects (36 vascular care, 29 standard care) had a baseline and a follow-up MRI and in 58 subjects, a follow-up scan could not be obtained due to advanced dementia or death. Subjects in the vascular care group had less progression of WMLs as measured with the WML change score (1.4 versus 2.3, P=0.03). There was no difference in the number of new lacunes or change in global cortical atrophy or medial temporal lobe atrophy between the 2 groups. Vascular care in patients with Alzheimer disease with cerebrovascular lesions slows progression of WMLs. Treatment aimed at vascular risk factors in patients with early Alzheimer disease may be beneficial, possibly in an even earlier stage of the disease.

  6. Diabetes and hypertension markedly increased the risk of ischemic stroke associated with high serum resistin concentration in a general Japanese population: the Hisayama Study

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    Kawamura Ryoichi

    2009-11-01

    Full Text Available Abstract Background Resistin, secreted from adipocytes, causes insulin resistance in mice. The relationship between resistin and coronary artery disease is highly controversial, and the information regarding resistin and ischemic stroke is limited. In the present study, the association between serum resistin concentration and cardiovascular disease (CVD was investigated in a general Japanese population. Methods A total of 3,201 community-dwelling individuals aged 40 years or older (1,382 men and 1,819 women were divided into quintiles of serum resistin, and the association between resistin and CVD was examined cross-sectionally. The combined effect of either diabetes or hypertension and high serum resistin was also assessed. Serum resistin was measured using ELISA. Results Compared to those without CVD, age- and sex-adjusted mean serum resistin concentrations were greater in subjects with CVD (p = 0.002 or ischemic stroke (p Conclusion Elevated serum resistin concentration appears to be an independent risk factor for ischemic stroke, especially lacunar and atherothrombotic infarction in the general Japanese population. The combination of high resistin and the presence of either diabetes or hypertension increased the risk of ischemic stroke.

  7. A CLINICAL STUDY OF STROKE IN YOUNG

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    Kumbha Thulasi Ram

    2015-02-01

    Full Text Available NTRIDUCTION : Stroke is one of the important causes of morbidity and mortality all over the world. Incidence of stroke steadily increases with age. Experts are concerned of the emerging stroke epidemic in India. Stroke affecting the young has potentially devastating consequence son the individual and his family. Certain risk factors are unique to the young. I t needs more studies for identification and modification of risk factors. The study aims to evaluate clinical features, risk factors, etiology and mortality of stroke in young patients. METHODS : 74 young patients satisfying the inclusion criteria were included in this study. A detailed history was taken from young stroke patients, systemic examination and required investigations were done. Data was collected in standardized proforma and analysed. RESULTS: Stroke in young accounts for 7.95% of stroke cases of all age groups. The mean age of the patients was 34.66 ± 7.48 years. Among 74 patients, 47(63.51% were male and 27(36.49% were female. Seizures, decreased consciousness, speech involvement and motor deficit were observed in 33.78%, 44.59%, 22.97% and 100% of cases respectively. 82.43% patients had ischemic and 17.57% patients had hemorrhagic stroke. Among ischemic stroke, large artery atherosclerosis was 16.21%, tuberculous meningoencephalitis with vasculitis was 16.21%, lacunar stroke was 10.81%, CVT was 10.81% and cardio embolic stroke was 6.76%. Smoking (59.45%, alcoholism (58.10%, hypertension (43.24%, coronary artery disease (8.10%, diabetes mellitus (10.81%, elevated total cholesterol (25.67%, elevated low density lipo proteins (22.97%, elevated triglycerides (27.02% and low HDL (22.97% were important risk factors. Carotid doppler was abnormal in 9.45% of patients. 6.76% patients had mitral stenosis in echocardiogram. Low protein C and protein S were found in 1.35% of patients. Eight (10.81% patients died during the hospital stay. INTERPRETATION AND CONCLUSIONS: The major risk

  8. Posture-Dependent Human 3He Lung Imaging in an Open Access MRI System: Initial Results

    CERN Document Server

    Tsai, L L; Li, C -H; Rosen, M S; Patz, S; Walsworth, R L

    2007-01-01

    The human lung and its functions are extremely sensitive to orientation and posture, and debate continues as to the role of gravity and the surrounding anatomy in determining lung function and heterogeneity of perfusion and ventilation. However, study of these effects is difficult. The conventional high-field magnets used for most hyperpolarized 3He MRI of the human lung, and most other common radiological imaging modalities including PET and CT, restrict subjects to lying horizontally, minimizing most gravitational effects. In this paper, we briefly review the motivation for posture-dependent studies of human lung function, and present initial imaging results of human lungs in the supine and vertical body orientations using inhaled hyperpolarized 3He gas and an open-access MRI instrument. The open geometry of this MRI system features a "walk-in" capability that permits subjects to be imaged in vertical and horizontal positions, and potentially allows for complete rotation of the orientation of the imaging su...

  9. Ischemic stroke subtypes and migraine with visual aura in the ARIC study.

    Science.gov (United States)

    Androulakis, X Michelle; Kodumuri, Nishanth; Giamberardino, Lauren D; Rosamond, Wayne D; Gottesman, Rebecca F; Yim, Eunsil; Sen, Souvik

    2016-12-13

    To investigate the association among migraine, ischemic stroke, and stroke subtypes in the Atherosclerosis Risk in Communities (ARIC) study. In this ongoing, prospective, longitudinal community-based cohort study, participants were given an interview ascertaining migraine history in 1993-1995, and were followed for all vascular events, including stroke. All stroke events over the subsequent 20 years were adjudicated and classified into stroke subtypes by standard definitions. Cox proportional hazards models adjusted for stroke risk factors were used to study the relationship between migraine and ischemic stroke, overall, as well as stroke subtypes (cardioembolic, lacunar, or thrombotic). We identified 1,622 migraineurs among 12,758 participants. Mean age of the study population at the 3rd clinical visit was 59 years. When compared to nonheadache participants, there was a significant association between migraine with visual aura and ischemic stroke (hazard ratio [HR] 1.7, 95% confidence interval [CI] 1.2-2.6, p = 0.008). Migraine without visual aura was not significantly associated with ischemic stroke (HR 1.2, CI 1.0-1.8, p = 0.28) when compared to nonheadache participants. Among the 3 subtypes of ischemic stroke evaluated, migraine with visual aura was significantly associated only with cardioembolic stroke (HR 3.7, 95% CI 1.6-8.7, p = 0.003). In participants with migraine with visual aura in late middle age, increased risk of cardioembolic stroke was observed. Migraine with visual aura was linked to increased stroke risk, while migraine without visual aura was not, over the period of 20 years. These results are specific to older migraineurs. © 2016 American Academy of Neurology.

  10. A quantitative approach to scar analysis.

    Science.gov (United States)

    Khorasani, Hooman; Zheng, Zhong; Nguyen, Calvin; Zara, Janette; Zhang, Xinli; Wang, Joyce; Ting, Kang; Soo, Chia

    2011-02-01

    Analysis of collagen architecture is essential to wound healing research. However, to date no consistent methodologies exist for quantitatively assessing dermal collagen architecture in scars. In this study, we developed a standardized approach for quantitative analysis of scar collagen morphology by confocal microscopy using fractal dimension and lacunarity analysis. Full-thickness wounds were created on adult mice, closed by primary intention, and harvested at 14 days after wounding for morphometrics and standard Fourier transform-based scar analysis as well as fractal dimension and lacunarity analysis. In addition, transmission electron microscopy was used to evaluate collagen ultrastructure. We demonstrated that fractal dimension and lacunarity analysis were superior to Fourier transform analysis in discriminating scar versus unwounded tissue in a wild-type mouse model. To fully test the robustness of this scar analysis approach, a fibromodulin-null mouse model that heals with increased scar was also used. Fractal dimension and lacunarity analysis effectively discriminated unwounded fibromodulin-null versus wild-type skin as well as healing fibromodulin-null versus wild-type wounds, whereas Fourier transform analysis failed to do so. Furthermore, fractal dimension and lacunarity data also correlated well with transmission electron microscopy collagen ultrastructure analysis, adding to their validity. These results demonstrate that fractal dimension and lacunarity are more sensitive than Fourier transform analysis for quantification of scar morphology. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  11. Study

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    Susan Grandy

    2012-01-01

    Full Text Available Purpose. This study examined the association between self-reported weight change and quality of life, and exercise and weight management behaviors among individuals with type 2 diabetes mellitus (T2DM. Methods. In the US SHIELD study, respondents reported whether they had lost or gained weight compared with 1 year earlier and completed the SHIELD-WQ-9 quality of life questionnaire as well as provided information on their exercise and weight management behaviors in the past 12 months. Results. Sixteen percent of the respondents reported gaining weight (n=460, and 30% reported losing weight (n=895. More respondents who reported losing weight exercised regularly, limited calorie and fat intake, and increased fiber, fruit, and vegetable intake compared with respondents who reported gaining weight (P<0.01. For all nine aspects of daily life, a significantly greater proportion of respondents who reported losing weight reported improved well-being (12%–44% compared with respondents who reported gaining weight (P<0.0001. Conclusions. Self-reported weight loss was associated with improved well-being, better exercise, and weight management behaviors among individuals with T2DM.

  12. Assessment of lung disease in children with cystic fibrosis using hyperpolarized 3-Helium MRI: comparison with Shwachman score, Chrispin-Norman score and spirometry

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    Beek, Edwin J.R. van [University of Sheffield, Unit of Academic Radiology, Sheffield (United Kingdom); University of Iowa, Department of Radiology, Carver College of Medicine, Iowa City (United States); University of Iowa, Department of Radiology, Iowa City, IA (United States); Hill, Catherine; Woodhouse, Neil; Fichele, Stanislao; Fleming, Sally; Wild, Jim M. [University of Sheffield, Unit of Academic Radiology, Sheffield (United Kingdom); Howe, Bridget; Bott, Sandra; Taylor, Christopher J. [University of Sheffield, Academic Unit of Child Health, Sheffield (United Kingdom)

    2007-04-15

    This study assesses the feasibility of hyperpolarized 3-Helium MRI in children with cystic fibrosis (CF) and correlates the findings with standard clinical parameters based on chest radiograph (CXR) and pulmonary function tests (PFT). An uncontrolled, observational study in eighteen children with cystic fibrosis aged 5 - 17 years (median 12.1 years), with different severity of disease was carried out. All subjects underwent routine clinical assessment including PFT and standard auxology; CXR was obtained and Shwachman and Chrispin-Norman scores calculated. Hyperpolarized 3-He magnetic resonance imaging (MRI) was carried out using a spin-exchange polarizer and a whole body 1.5 T scanner. Ventilation distribution images were obtained during a 21-second breath-hold and scored according to previously defined criteria. Spearman's non-parametric correlations test was performed to assess for statistical significance at the p<0.05 level. The children tolerated the procedure well. No desaturation events were observed during 3-He MRI. A significant, albeit moderate, correlation was found between MRI score and FEV1% predicted (r=-0.41; p=0.047) and FVC% predicted (r=-0.42; p=0.04), while there were trends of correlations between Shwachman score and MRI score (r=-0.38; p=0.06) and Shwachman score and FEV1% predicted (r=0.39; p=0.055). The feasibility of hyperpolarized 3-He MRI in children with CF was demonstrated. MRI appears to be able to demonstrate functional lung changes, although correlations with routine clinical tests are only moderate to poor. This non-ionising radiation technique could be useful for monitoring lung disease and assessing therapy in this patient population. (orig.)

  13. Novel computer vision algorithm for the reliable analysis of organelle morphology in whole cell 3D images--A pilot study for the quantitative evaluation of mitochondrial fragmentation in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Lautenschläger, Janin; Lautenschläger, Christian; Tadic, Vedrana; Süße, Herbert; Ortmann, Wolfgang; Denzler, Joachim; Stallmach, Andreas; Witte, Otto W; Grosskreutz, Julian

    2015-11-01

    The function of intact organelles, whether mitochondria, Golgi apparatus or endoplasmic reticulum (ER), relies on their proper morphological organization. It is recognized that disturbances of organelle morphology are early events in disease manifestation, but reliable and quantitative detection of organelle morphology is difficult and time-consuming. Here we present a novel computer vision algorithm for the assessment of organelle morphology in whole cell 3D images. The algorithm allows the numerical and quantitative description of organelle structures, including total number and length of segments, cell and nucleus area/volume as well as novel texture parameters like lacunarity and fractal dimension. Applying the algorithm we performed a pilot study in cultured motor neurons from transgenic G93A hSOD1 mice, a model of human familial amyotrophic lateral sclerosis. In the presence of the mutated SOD1 and upon excitotoxic treatment with kainate we demonstrate a clear fragmentation of the mitochondrial network, with an increase in the number of mitochondrial segments and a reduction in the length of mitochondria. Histogram analyses show a reduced number of tubular mitochondria and an increased number of small mitochondrial segments. The computer vision algorithm for the evaluation of organelle morphology allows an objective assessment of disease-related organelle phenotypes with greatly reduced examiner bias and will aid the evaluation of novel therapeutic strategies on a cellular level.

  14. Pattern and Rate of Cognitive Decline in Cerebral Small Vessel Disease: A Prospective Study.

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    Andrew J Lawrence

    Full Text Available Cognitive impairment, predominantly affecting processing speed and executive function, is an important consequence of cerebral small vessel disease (SVD. To date, few longitudinal studies of cognition in SVD have been conducted. We determined the pattern and rate of cognitive decline in SVD and used the results to determine sample size calculations for clinical trials of interventions reducing cognitive decline.121 patients with MRI confirmed lacunar stroke and leukoaraiosis were enrolled into the prospective St George's Cognition And Neuroimaging in Stroke (SCANS study. Patients attended one baseline and three annual cognitive assessments providing 36 month follow-up data. Neuropsychological assessment comprised a battery of tests assessing working memory, long-term (episodic memory, processing speed and executive function. We calculated annualized change in cognition for the 98 patients who completed at least two time-points.Task performance was heterogeneous, but significant cognitive decline was found for the executive function index (p<0.007. Working memory and processing speed decreased numerically, but not significantly. The executive function composite score would require the smallest samples sizes for a treatment trial with an aim of halting decline, but this would still require over 2,000 patients per arm to detect a 30% difference with power of 0.8 over a three year follow-up.The pattern of cognitive decline seen in SVD over three years is consistent with the pattern of impairments at baseline. Rates of decline were slow and sample sizes would need to be large for clinical trials aimed at halting decline beyond initial diagnosis using cognitive scores as an outcome measure. This emphasizes the importance of more sensitive surrogate markers in this disease.

  15. Study

    Directory of Open Access Journals (Sweden)

    Erum Zahir

    2017-05-01

    Full Text Available Physicochemical properties like density, viscosity, boiling point, saponification value (SV, iodine value (IV,and peroxide value (PV of Corn and Mustard oils were studied to evaluate the compositional quality of oils and also to investigate the effect on the use of same oil for repeated frying as it ultimately changes the physicochemical, nutritional and sensory properties of the oil. FT-IR spectroscopy was used to evaluate the degree of oxidation after heating and frying processes. Results revealed that due to the temperature change in the oil there is a notable difference in the spectral band which showed that the proportions of the fatty acids were changed. The spectra of Corn oil at the boiling point and at multiple frying times with a piece of potato showed frequencies in range of 2852.7–2926.0 cm−1 while in Mustard oil an additional peak was observed at 3633.8 cm−1 which exhibits the secondary oxidized product formation.

  16. Quantitative {sup 1}H and hyperpolarized {sup 3}He magnetic resonance imaging: Comparison in chronic obstructive pulmonary disease and healthy never-smokers

    Energy Technology Data Exchange (ETDEWEB)

    Owrangi, Amir M., E-mail: aowrangi@robats.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); Graduate Program in Biomedical Engineering, The University of Western Ontario, London (Canada); Wang, Jian X., E-mail: jxwang@robats.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); Applied Science Laboratories, General Electric Healthcare (Canada); Wheatley, Andrew, E-mail: awheat@imaging.robarts.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); McCormack, David G., E-mail: David.Mccormack@lhsc.on.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); Division of Respirology, Department of Medicine, The University of Western Ontario, London (Canada); Parraga, Grace, E-mail: gparraga@robats.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); Graduate Program in Biomedical Engineering, The University of Western Ontario, London (Canada); Department of Medical Imaging, The University of Western Ontario, London (Canada); Department of Medical Biophysics, The University of Western Ontario, London (Canada)

    2014-01-15

    Objective: The aim of this study was to quantitatively evaluate the relationship between short echo time pulmonary {sup 1}H magnetic resonance imaging (MRI) signal intensity (SI) and {sup 3}He MRI apparent diffusion coefficients (ADC), high-resolution computed tomography (CT) measurements of emphysema, and pulmonary function measurements. Materials and methods: Nine healthy never-smokers and 11 COPD subjects underwent same-day plethysmography, spirometry, short echo time ((TE) = 1.2 ms) {sup 1}H and diffusion-weighted hyperpolarized {sup 3}He MRI (b = 1.6 s/cm{sup 2}) at 3.0 T. In addition, for COPD subjects only, CT densitometry was also performed. Results: Mean {sup 1}H SI was significantly greater for never-smokers (12.1 ± 1.1 arbitrary units (AU)) compared to COPD subjects (10.9 ± 1.3 AU, p = 0.04). The {sup 1}H SI AP-gradient was also significantly greater for never-smokers (0.40 AU/cm, R{sup 2} = 0.94) compared to COPD subjects (0.29 AU/cm, R{sup 2} = 0.968, p = 0.05). There was a significant correlation between {sup 1}H SI and {sup 3}He ADC (r = −0.58, p = 0.008) and significant correlations between {sup 1}H MR SI and CT measurements of emphysema (RA{sub 950}, r = −0.69, p = 0.02 and HU{sub 15}, r = 0.66, p = 0.03). Conclusions: The significant and moderately strong relationship between {sup 1}H SI and {sup 3}He ADC, as well as between {sup 1}H SI and CT measurements of emphysema suggests that these imaging methods and measurements may be quantifying similar tissue changes in COPD and that pulmonary {sup 1}H SI may be used to monitor emphysema as a complement to CT and noble gas MRI.

  17. Exhaled Aerosol Pattern Discloses Lung Structural Abnormality: A Sensitivity Study Using Computational Modeling and Fractal Analysis

    Science.gov (United States)

    Xi, Jinxiang; Si, Xiuhua A.; Kim, JongWon; Mckee, Edward; Lin, En-Bing

    2014-01-01

    Background Exhaled aerosol patterns, also called aerosol fingerprints, provide clues to the health of the lung and can be used to detect disease-modified airway structures. The key is how to decode the exhaled aerosol fingerprints and retrieve the lung structural information for a non-invasive identification of respiratory diseases. Objective and Methods In this study, a CFD-fractal analysis method was developed to quantify exhaled aerosol fingerprints and applied it to one benign and three malign conditions: a tracheal carina tumor, a bronchial tumor, and asthma. Respirations of tracer aerosols of 1 µm at a flow rate of 30 L/min were simulated, with exhaled distributions recorded at the mouth. Large eddy simulations and a Lagrangian tracking approach were used to simulate respiratory airflows and aerosol dynamics. Aerosol morphometric measures such as concentration disparity, spatial distributions, and fractal analysis were applied to distinguish various exhaled aerosol patterns. Findings Utilizing physiology-based modeling, we demonstrated substantial differences in exhaled aerosol distributions among normal and pathological airways, which were suggestive of the disease location and extent. With fractal analysis, we also demonstrated that exhaled aerosol patterns exhibited fractal behavior in both the entire image and selected regions of interest. Each exhaled aerosol fingerprint exhibited distinct pattern parameters such as spatial probability, fractal dimension, lacunarity, and multifractal spectrum. Furthermore, a correlation of the diseased location and exhaled aerosol spatial distribution was established for asthma. Conclusion Aerosol-fingerprint-based breath tests disclose clues about the site and severity of lung diseases and appear to be sensitive enough to be a practical tool for diagnosis and prognosis of respiratory diseases with structural abnormalities. PMID:25105680

  18. Hospital arrival time and functional outcome after acute ischaemic stroke: results from the PREMIER study.

    Science.gov (United States)

    León-Jiménez, C; Ruiz-Sandoval, J L; Chiquete, E; Vega-Arroyo, M; Arauz, A; Murillo-Bonilla, L M; Ochoa-Guzmán, A; Carrillo-Loza, K; Ramos-Moreno, A; Barinagarrementeria, F; Cantú-Brito, C

    2014-05-01

    Information regarding hospital arrival times after acute ischaemic stroke (AIS) has mainly been gathered from countries with specialised stroke units. Little data from emerging nations is available. We aim to identify factors associated with achieving hospital arrival times of less than 1, 3, and 6 hours, and analyse how arrival times are related to functional outcomes after AIS. We analysed data from patients with AIS included in the PREMIER study (Primer Registro Mexicano de Isquemia Cerebral) which defined time from symptom onset to hospital arrival. The functional prognosis at 30 days and at 3, 6, and 12 months was evaluated using the modified Rankin Scale. Among 1096 patients with AIS, 61 (6%) arrived in <1 hour, 250 (23%) in <3 hours, and 464 (42%) in <6 hours. The factors associated with very early (<1 hour) arrival were family history of ischemic heart disease and personal history of migraines; in <3 hours: age 40-69 years, family history of hypertension, personal history of dyslipidaemia and ischaemic heart disease, and care in a private hospital; in <6 hours: migraine, previous stroke, ischaemic heart disease, care in a private hospital, and family history of hypertension. Delayed hospital arrival was associated with lacunar stroke and alcoholism. Only 2.4% of patients underwent thrombolysis. Regardless of whether or not thrombolysis was performed, arrival time in <3 hours was associated with lower mortality at 3 and 6 months, and with fewer in-hospital complications. A high percentage of patients had short hospital arrival times; however, less than 3% underwent thrombolysis. Although many factors were associated with early hospital arrival, it is a priority to identify in-hospital barriers to performing thrombolysis. Copyright © 2013 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

  19. Study on the Prevalence and Corelation of Carotid Atherosclerosis in Stroke Patients

    Institute of Scientific and Technical Information of China (English)

    Wei Hua; Wang Yongjun; Yah Zhenying

    2000-01-01

    Objective To assess the prevalence and severity of carotid atherosclerosis in stroke patients and the risk factors of carotid atherosclerosis. Methods Two hundred fifty-one ischemic stroke patients,46 ccrcbral hemorrhagc patients and 96 control subjects were entercd into this study. Sonographic assessment of the extracranial carotid arteries was performed in all patients. Diametcr. IMT, plaques and percentage ratio of lumen stenosis were observcd. Results (1)The prevalence of carotid plaqucs was prominent in stroke patients than the control subjects(63.0%vs 36.5%). (2)The prevalencc of lumen stenosis>50% in ischemic stroke patients was higher than the cerebral hemorrhage patients and control subjects (15.6% vs 4.3%. 2.1%).(3) The prevalence of severe carotid artery stcnosis(>75%) was promincnt in aged 61~70 years old patients.(4)Our data revealed 30% of the cortical infarction subgroup, 17.5%of the subcortical infarction subgroup, 17% of the lacunar infarction subgroup,8% of the vcrtibral-basilar artery infarction subgroup.2.8% of thc CT normal subgroup possessed carotid stcnosis >50%. (5)Age, diabetes mellitus and ApoAl(inversely) were independent predictors of the extracranial carotid atherosclcrosis. Discusssion (Ⅰ)There is close relation between extracraniai carotid atherosclerosis and ischemic cerebrovascular disease.(2)The extent of serious carotid artery stcnosis in aged patients was lower.(3)Thc severity of extracranial carotid artery atherosclerosis was prominent in patients with conical infarction. Conclusion There is a high prevalence of extracranial carotid atherosclerosis in Chinese stroke patients.

  20. Exhaled aerosol pattern discloses lung structural abnormality: a sensitivity study using computational modeling and fractal analysis.

    Directory of Open Access Journals (Sweden)

    Jinxiang Xi

    Full Text Available Exhaled aerosol patterns, also called aerosol fingerprints, provide clues to the health of the lung and can be used to detect disease-modified airway structures. The key is how to decode the exhaled aerosol fingerprints and retrieve the lung structural information for a non-invasive identification of respiratory diseases.In this study, a CFD-fractal analysis method was developed to quantify exhaled aerosol fingerprints and applied it to one benign and three malign conditions: a tracheal carina tumor, a bronchial tumor, and asthma. Respirations of tracer aerosols of 1 µm at a flow rate of 30 L/min were simulated, with exhaled distributions recorded at the mouth. Large eddy simulations and a Lagrangian tracking approach were used to simulate respiratory airflows and aerosol dynamics. Aerosol morphometric measures such as concentration disparity, spatial distributions, and fractal analysis were applied to distinguish various exhaled aerosol patterns.Utilizing physiology-based modeling, we demonstrated substantial differences in exhaled aerosol distributions among normal and pathological airways, which were suggestive of the disease location and extent. With fractal analysis, we also demonstrated that exhaled aerosol patterns exhibited fractal behavior in both the entire image and selected regions of interest. Each exhaled aerosol fingerprint exhibited distinct pattern parameters such as spatial probability, fractal dimension, lacunarity, and multifractal spectrum. Furthermore, a correlation of the diseased location and exhaled aerosol spatial distribution was established for asthma.Aerosol-fingerprint-based breath tests disclose clues about the site and severity of lung diseases and appear to be sensitive enough to be a practical tool for diagnosis and prognosis of respiratory diseases with structural abnormalities.

  1. Application of Texture Analysis to Study Small Vessel Disease and Blood–Brain Barrier Integrity

    Directory of Open Access Journals (Sweden)

    Maria del C. Valdés Hernández

    2017-07-01

    Full Text Available ObjectivesWe evaluate the alternative use of texture analysis for evaluating the role of blood–brain barrier (BBB in small vessel disease (SVD.MethodsWe used brain magnetic resonance imaging from 204 stroke patients, acquired before and 20 min after intravenous gadolinium administration. We segmented tissues, white matter hyperintensities (WMH and applied validated visual scores. We measured textural features in all tissues pre- and post-contrast and used ANCOVA to evaluate the effect of SVD indicators on the pre-/post-contrast change, Kruskal–Wallis for significance between patient groups and linear mixed models for pre-/post-contrast variations in cerebrospinal fluid (CSF with Fazekas scores.ResultsTextural “homogeneity” increase in normal tissues with higher presence of SVD indicators was consistently more overt than in abnormal tissues. Textural “homogeneity” increased with age, basal ganglia perivascular spaces scores (p < 0.01 and SVD scores (p < 0.05 and was significantly higher in hypertensive patients (p < 0.002 and lacunar stroke (p = 0.04. Hypertension (74% patients, WMH load (median = 1.5 ± 1.6% of intracranial volume, and age (mean = 65.6 years, SD = 11.3 predicted the pre/post-contrast change in normal white matter, WMH, and index stroke lesion. CSF signal increased with increasing SVD post-contrast.ConclusionA consistent general pattern of increasing textural “homogeneity” with increasing SVD and post-contrast change in CSF with increasing WMH suggest that texture analysis may be useful for the study of BBB integrity.

  2. Achieved Blood Pressures in the Secondary Prevention of Small Subcortical Strokes (SPS3) Study: Challenges and Lessons Learned

    Science.gov (United States)

    Pergola, Pablo E.; Szychowski, Jeff M.; Talbert, Robert; del Brutto, Oscar; Castellanos, Mar; Graves, John W.; Matamala, Gonzalo; Pretell, Edwin Javier; Yee, Jerry; Rebello, Rosario; Zhang, Yu; Benavente, Oscar R.

    2014-01-01

    BACKGROUND Lowering blood pressure (BP) after stroke remains a challenge, even in the context of clinical trials. The Secondary Prevention of Small Subcortical Strokes (SPS3) BP protocol, BP management during the study, and achieved BPs are described here. METHODS Patients with recent symptomatic lacunar stroke were randomized to 1 of 2 levels of systolic BP (SBP) targets: lower: <130mm Hg, or higher: 130–149mm Hg. SBP management over the course of the trial was examined by race/ethnicity and other baseline conditions. RESULTS Mean SBP decreased for both groups from baseline to the last follow-up, from 142.4 to 126.7mm Hg for the lower SBP target group and from 143.6 to 137.4mm Hg for the higher SBP target group. At baseline, participants in both groups used an average of 1.7±1.2 antihypertensive medications, which increased to a mean of 2.4±1.4 (lower group) and 1.8±1.4 (higher group) by the end-study visit. It took an average of 6 months for patients to reach their SBP target, sustained to the last follow-up. Black participants had the highest proportion of SBP ≥150mm Hg at both study entry (40%) and end-study visit (17%), as compared with whites (9%) and Hispanics (11%). CONCLUSIONS These results show that it is possible to safely lower BP even to a SBP goal <130mm Hg in a variety of patients and settings, including private and academic centers in multiple countries. This provides further support for protocol-driven care in lowering BP and consequently reducing the burden of stroke. PMID:24610884

  3. Troponin T, NT-pro BNP, and Incidence of Stroke: The Atherosclerosis Risk in Communities (ARIC) Study

    Science.gov (United States)

    Folsom, Aaron R.; Nambi, Vijay; Bell, Elizabeth J.; Oluleye, Oludamilola W.; Gottesman, Rebecca F.; Lutsey, Pamela L.; Huxley, Rachel R.; Ballantyne, Christie M.

    2013-01-01

    Background and Purpose Increased levels of plasma troponins and natriuretic peptides are associated with increased risk of cardiovascular disease, but only limited information exists on these biomarkers and stroke occurrence. In a prospective epidemiological study, we tested the hypothesis that high-sensitivity troponin T (TnT) and N-terminal pro B-type natriuretic peptide (NT-proBNP) are associated positively with incidence of stroke. Methods The Atherosclerosis Risk in Communities (ARIC) Study measured plasma TnT and NT-proBNP in 10,902 men or women initially free of stroke and followed them for a mean of 11.3 years for stroke occurrence (n=507). Results Both biomarkers were associated positively with total stroke, nonlacunar ischemic, and especially, cardioembolic stroke, but not with lacunar or hemorrhagic stroke. For example, after adjustment for prevalent risk factors and cardiac diseases, the hazard ratios (95% confidence intervals) for jointly high values of TnT and NT-proBNP (versus neither biomarker high) were 2.70 (1.92, 3.79) for total stroke and 6.26 (3.40, 11.5) for cardioembolic stroke. Associations with stroke appeared somewhat stronger for NT-proBNP than TnT. Strikingly, approximately 58% of cardioembolic strokes occurred in the highest quintile of pre-stroke NT-proBNP, and 32% of cardioembolic strokes occurred in participants who had both NT-proBNP in the highest quintile and were known by ARIC to have atrial fibrillation sometime before their cardioembolic stroke occurrence. Conclusions In the general population, elevated plasma TnT and NT-proBNP concentrations are associated with increased risk of cardioembolic and other nonlacunar ischemic strokes. PMID:23471272

  4. Cerebral Small Vessel Disease and Risk of Death, Ischemic Stroke, and Cardiac Complications in Patients With Atherosclerotic Disease The Second Manifestations of ARTerial disease-Magnetic Resonance (SMART-MR) Study

    NARCIS (Netherlands)

    M.M.A. Conijn; R.P. Kloppenborg; A. Algra; W.P.T.M. Mali; L.J. Kappelle; K.L. Vincken; Y. van der Graaf; M.I. Geerlings

    2011-01-01

    Background and Purpose-Cerebral small vessel disease may be related to vascular and nonvascular pathology. We assessed whether lacunar infarcts and white matter lesions on MRI increased the risk of vascular and nonvascular death and future vascular events in patients with atherosclerotic disease. Me

  5. Cortical changes in cerebral small vessel diseases: a 3D MRI study of cortical morphology in CADASIL

    Energy Technology Data Exchange (ETDEWEB)

    Jouvent, E.; Bousser, M.G.; Chabriat, H. [CHU Lariboisiere, AP HP, INSERM, UMR 740, Dept Neurol, Lariboisiere (France); Jouvent, E.; Bousser, M.G.; Chabriat, H. [Univ Paris 07, F-75221 Paris 05 (France); Porcher, R. [Hop St Louis, AP-HP, Dept Biostat, St Louis (France); Viswanathan, A. [Massachusetts Gen Hosp, Dept Neurol, Boston, MA 02114 (United States); Viswanathan, A. [Massachusetts Gen Hosp, Clin Trials Unit, Boston, MA 02114 (United States); Viswanathan, A. [Harvard Univ, Sch Med, Boston, MA (United States); O' Sullivan, M.; Dichgans, M. [Univ Munich, Klinikum Grosshadern, Dept Neurol, D-81377 Munich (Germany); Guichard, J.P. [CHU Lariboisiere, AP-HP, Dept Neuroradiol, Lariboisiere (France)

    2008-07-01

    Brain atrophy represents a key marker of disease progression in cerebrovascular disorders. The 3D changes of cortex morphology occurring during the course of small vessel diseases of the brain (SVDB) remain poorly understood. The objective of this study was to assess the changes affecting depth and surface area of cortical sulci and their clinical and radiological correlates in a cohort of patients with cerebral autosomal dominant arteriolopathy with subcortical infarcts and leukoencephalopathy (CADASIL), a genetic SVDB. Data were obtained from a series of 69 CADASIL patients. Validated methods were used to determine depth and surface area of four cortical sulci. The ratio of brain to intracranial cavity volumes (brain parenchymal fraction-BPF), volume of lacunar lesions (LL) and of white matter hyper-intensities, number of cerebral micro-haemorrhages, and mean apparent diffusion coefficient were also measured. Association between depth and surface area of the cortical sulci and BPF, clinical status and subcortical MRI lesions were tested. Depth and surface area of cortical sulci obtained in 54 patients were strongly correlated with both cognitive score and disability scales. Depth was related to the extent of subcortical lesions, surface area was related only to age. In additional analyses, the depth of the cingular sulcus was independently associated with the volume of LL (P 0.001), and that of the superior frontal sulcus with the mean apparent diffusion coefficient (P 0.003). In CADASIL, important morphological changes of cortical sulci occur in association with clinical worsening,extension of subcortical tissue damage and progression of global cerebral atrophy. These results suggest that the examination of cortical morphology may be of high clinical relevance in SVDB. (authors)

  6. Location of cerebrovascular and degenerative changes, depressive symptoms and cognitive functioning in later life: the SMART-Medea study.

    Science.gov (United States)

    Grool, Anne M; van der Graaf, Yolanda; Mali, Willem P T M; Geerlings, Mirjam I

    2011-10-01

    Depression and cognitive impairment are highly prevalent in later life and frequently co-occur. Structural changes in critical brain regions may underlie both conditions. The authors examined associations of infarcts, white-matter lesions (WML) and atrophy at different locations with depressive symptoms and cognitive functioning. Within the Second Manifestations of Arterial Disease-Memory, Depression and Aging (SMART-Medea) study, cross-sectional analyses were performed in 585 non-demented patients aged ≥50 years with symptomatic atherosclerotic disease. Volumetric measures of WML and atrophy were obtained with 1.5 T MRI; infarcts were rated visually. Depressive symptoms were assessed with the Patient Health Questionnaire-9 (score ≥6). z Scores of executive functioning, memory and processing speed were calculated. Analyses were adjusted for age, sex, education, intelligence, vascular disease, physical functioning and co-occurring brain changes. Depressive symptoms were present in 102 (17%) patients and were associated with poorer memory (B=-0.26, 95% CI -0.47 to -0.06). Large subcortical infarcts and lacunar infarcts in deep white-matter tracts were both associated with depressive symptoms (RR=2.66, 95% CI 1.28 to 5.54; RR=2.02, 95% CI 1.14 to 3.59) and poorer executive functioning and memory. Periventricular WML volume was associated with poorer executive functioning; cortical infarcts in the left hemisphere and media flow region, ventricular volume and cortical atrophy were associated with a slower processing speed. In this sample of non-demented older persons, subcortical infarcts contributed to an increased risk of depressive symptoms as well as cognitive impairment. This depended on location in projecting white-matter tracts, and not on infarct size.

  7. Studies on intracranial collateral circulation with multi-slice CT angiography in patients with symptomatic cerebral artery stenosis

    Directory of Open Access Journals (Sweden)

    Shu-qing ZHOU

    2011-06-01

    Full Text Available Objective To explore the features of intracranial collateral circulation in patients with symptomatic cerebral artery stenosis.Method Ninety-four patients with ischemic cerebrovascular disease admitted from Apr.2004 to Jun.2009 were involved in present study.All the patients were examined with cerebral multi-slice CT angiography,and the features of cerebral artery stenosis and intracranial collateral circulation were evaluated using maximum intensity projection(MIP and volume rendering(VR images of CT angiography.Result Of the 94 patients involved,48 were diagnosed as cerebral artery stenosis,including 29 cases of cerebral infarction,18 of transient ischemic attack(TIA and 1 of moyamoya disease(MMD.Among the 14 cases of severe cerebral artery stenosis or occlusion,cerebral infarction was found in 6 cases with lesser intracranial collateral vessels(including massive cerebral infarction in 4 cases and watershed infarction in 2 cases,and focal infarction of central semi-ovale in 1 case and TIA in 7 cases were found with abundant intracranial collateral vessels.Multiple lacunar infarction was found in 22 cases of mild or moderate cerebral artery stenosis,but there was no significant correlation between the stenosed arteries and infarction sites.Abundant intracranial collateral vessels were found in one patient with Moyamoya disease but no infarction was observed.Conclusions Intracranial collateral circulation plays an important role of compensation in patients with severe cerebral artery stenosis or occlusion.Cerebral angiography with multi-slice CT is of great significance in evaluation of cerebral artery stenosis and intracranial collateral circulation.

  8. Five-year prognosis after mild to moderate ischemic stroke by stroke subtype: a multi-clinic registry study.

    Directory of Open Access Journals (Sweden)

    Yumei Lv

    Full Text Available BACKGROUND AND PURPOSE: Mild to moderate ischemic stroke is a common presentation in the outpatient setting. Among the various subtypes of stroke, lacunar infarction (LI is generally very common. Currently, little is known about the long-term prognosis and factors associated with the prognosis between LI and non-LI. This study aims to compare the risk of death and acute cardiovascular events between patients with LI and non-LI, and identify potential risk factors associated with these outcomes. METHODS: A total of 710 first-ever ischemic stroke patients (LI: 474, non-LI: 263 from 18 clinics were recruited consecutively from 2003 to 2004. They were prospectively followed-up until the end of 2008. Hazard ratios and 95% confidence intervals were calculated using multivariable Cox proportional hazards regression. RESULTS: After a 5-year follow up, 54 deaths and 96 acute cardiovascular events occurred. Recurrent stroke was the most common cause of death (19 cases, 35.18% and new acute cardiovascular events (75 cases, 78.13%. There were no significant differences between patients with LI and non-LI in their risks of death, new cardiovascular events, and recurrent stroke after adjusting for age, sex, hypertension, diabetes, cardiac diseases, body mass index, dyslipidemia, smoking, alcohol consumption, ADL dependence, and depressive symptoms. Among the modifiable risk factors, diabetes, hypertension, ADL dependency, and symptoms of depression were independent predictors of poor outcomes in patients with LI. In non-LI patients, however, no modifiable risk factors were detected for poor outcomes. CONCLUSION: Long-term outcomes did not differ significantly between LI and non-LI patients. Detecting and managing vascular risk factors and depression as well as functional rehabilitation may improve the prognoses of LI patients.

  9. Impact of cerebral white matter changes on functionality in older adults: An overview of the LADIS Study results and future directions.

    Science.gov (United States)

    Pantoni, Leonardo; Fierini, Fabio; Poggesi, Anna

    2015-12-01

    The evidence on the clinical significance of cerebral white matter changes (WMC) has mounted over the past few decades. WMC are recognized as one of the neuroimaging features of cerebral small vessel disease, and are associated with various disturbances and a poor prognosis. The Leukoaraiosis and Disability (LADIS) Study has contributed substantially to this body of knowledge. LADIS is a European multicenter collaboration aimed at assessing the role of WMC as an independent predictor of the transition to disability in initially non-disabled patients aged 65-84 years. Besides the demonstration that severe WMC cause a more than double risk of transition from an autonomous to a dependent status after 3 years of follow-up, the LADIS Study has also provided evidence on the role of WMC in relation to the decline of cognitive and motor performances, depressive symptoms associated with aging and cerebrovascular diseases, the presence of urinary disturbances, and various neurological abnormalities. The possible role of other lesions (lacunar infarcts, cerebral atrophy, corpus callosum morphology) and microstructural abnormalities (diffusion-weighted imaging changes in normal appearing brain tissue and in WMC) has also been investigated. In the present article, we review the main results of the LADIS Study and offer some considerations for future developments in the field, paying attention to the potential use of WMC progression as a surrogate marker in intervention trials in cerebral small vessel diseases. We also discuss some therapeutic perspectives regarding the beneficial impact of physical activity on the risk of vascular cognitive impairment in patients with WMC.

  10. 3D Porous Architecture of Stacks of β-TCP Granules Compared with That of Trabecular Bone: A microCT, Vector Analysis, and Compression Study.

    Science.gov (United States)

    Chappard, Daniel; Terranova, Lisa; Mallet, Romain; Mercier, Philippe

    2015-01-01

    The 3D arrangement of porous granular biomaterials usable to fill bone defects has received little study. Granular biomaterials occupy 3D space when packed together in a manner that creates a porosity suitable for the invasion of vascular and bone cells. Granules of beta-tricalcium phosphate (β-TCP) were prepared with either 12.5 or 25 g of β-TCP powder in the same volume of slurry. When the granules were placed in a test tube, this produced 3D stacks with a high (HP) or low porosity (LP), respectively. Stacks of granules mimic the filling of a bone defect by a surgeon. The aim of this study was to compare the porosity of stacks of β-TCP granules with that of cores of trabecular bone. Biomechanical compression tests were done on the granules stacks. Bone cylinders were prepared from calf tibia plateau, constituted high-density (HD) blocks. Low-density (LD) blocks were harvested from aged cadaver tibias. Microcomputed tomography was used on the β-TCP granule stacks and the trabecular bone cores to determine porosity and specific surface. A vector-projection algorithm was used to image porosity employing a frontal plane image, which was constructed line by line from all images of a microCT stack. Stacks of HP granules had porosity (75.3 ± 0.4%) and fractal lacunarity (0.043 ± 0.007) intermediate between that of HD (respectively 69.1 ± 6.4%, p TCP granules than bone trabecule. Stacks of HP granules represent a scaffold that resembles trabecular bone in its porous microarchitecture.

  11. Multiscale study on the spatial heterogeneity of remotely-sensed evapotranspiration in the typical Oasis of Tarim Basin

    Science.gov (United States)

    Liu, Chuansheng; Zhang, Wanchang

    2010-11-01

    Time series of regional evapotranspiration (ET) of the typical oasis in the Tarim Basin were investigated and calculated by integrating remotely sensed surface parameters into the improved Surface Energy Balance Algorithm for Land (SEBAL) model. The distributed average and maximum daily actual ET was calculated based on the instantaneous ET, corresponding to oasis vegetation types for investigating the relationships between spatial difference of actual ET and land cover types in arid environment. Different land cover types and surface water conditions in the Keriya Oasis can be distinguished obviously in NDVI-LST feature space and characterized by the Temperature Vegetation Dryness Index (TVDI). Lacunarity index was employed to determine heterogeneity and spatial patterns of ET landscape in the Keriya Oasis by using RS and GIS techniques. Spatially distributed scale-dependent regularities of land cover types across a range of patch sizes were revealed by changes of lacunarity curves. It is explicitly suggested that lacunarity index is quite effective to quantify the scale-dependent ET spatial heterogeneity and useful to figure out the water use pattern of oasis-desert landscape.

  12. Association of MTHFR C677T Genotype With Ischemic Stroke Is Confined to Cerebral Small Vessel Disease Subtype.

    Science.gov (United States)

    Rutten-Jacobs, Loes C A; Traylor, Matthew; Adib-Samii, Poneh; Thijs, Vincent; Sudlow, Cathie; Rothwell, Peter M; Boncoraglio, Giorgio; Dichgans, Martin; Meschia, James; Maguire, Jane; Levi, Christopher; Rost, Natalia S; Rosand, Jonathan; Hassan, Ahamad; Bevan, Steve; Markus, Hugh S

    2016-03-01

    Elevated plasma homocysteine levels are associated with stroke. However, this might be a reflection of bias or confounding because trials have failed to demonstrate an effect from homocysteine lowering in stroke patients, although a possible benefit has been suggested in lacunar stroke. Genetic studies could potentially overcome these issues because genetic variants are inherited randomly and are fixed at conception. Therefore, we tested the homocysteine levels-associated genetic variant MTHFR C677T for association with magnetic resonance imaging-confirmed lacunar stroke and compared this with associations with large artery and cardioembolic stroke subtypes. We included 1359 magnetic resonance imaging-confirmed lacunar stroke cases, 1824 large artery stroke cases, 1970 cardioembolic stroke cases, and 14 448 controls, all of European ancestry. Furthermore, we studied 3670 ischemic stroke patients in whom white matter hyperintensities volume was measured. We tested MTHFR C677T for association with stroke subtypes and white matter hyperintensities volume. Because of the established association of homocysteine with hypertension, we additionally stratified for hypertension status. MTHFR C677T was associated with lacunar stroke (P=0.0003) and white matter hyperintensity volume (P=0.04), but not with the other stroke subtypes. Stratifying the lacunar stroke cases for hypertension status confirmed this association in hypertensive individuals (P=0.0002), but not in normotensive individuals (P=0.30). MTHFR C677T was associated with magnetic resonance imaging-confirmed lacunar stroke, but not large artery or cardioembolic stroke. The association may act through increased susceptibility to, or interaction with, high blood pressure. This heterogeneity of association might explain the lack of effect of lowering homocysteine in secondary prevention trials which included all strokes. © 2016 The Authors.

  13. Depressive symptoms as a predictor of quality of life in cerebral small vessel disease, acting independently of disability; a study in both sporadic SVD and CADASIL

    Science.gov (United States)

    Brookes, Rebecca L; Willis, Thomas A; Patel, Bhavini; Morris, Robin G; Markus, Hugh S

    2013-01-01

    Background Cerebral small vessel disease (SVD) causes lacunar stroke, and more recently has been implicated as a cause of depression. Factors causing reduced quality of life (QoL) in SVD, including the relative contributions of disability and depressive symptoms, remain uncertain. Hypothesis Depressive symptoms are a major predictor of reduced QoL in SVD, acting independently of disability. Methods The Stroke-Specific QoL scale was completed by 100 patients with SVD (lacunar stroke with MRI lacunar infarct) and 55 controls. We repeated the protocol in 40 patients with the young onset genetic form of SVD, CADASIL, and 35 controls. Disability (modified Rankin Scale), [instrumental] activities of daily living (IADL, ADL), cognition (Mini Mental State Examination) and depressive symptoms (Geriatric Depression Scale, Montgomery-Åsberg Depression Rating Scale) were measured. Results QoL was significantly lower in SVD than controls: mean (SD), 196.8 (35.2) versus 226.8(15.3), pSVD. They account for greater reduction than disability, and the association is independent of disability. This relationship may reflect the proposed causal association between white matter disease and depression. Treatment of depressive symptoms might significantly improve QoL in SVD. PMID:22364606

  14. Impact of field number and beam angle on functional image-guided lung cancer radiotherapy planning

    Science.gov (United States)

    Tahir, Bilal A.; Bragg, Chris M.; Wild, Jim M.; Swinscoe, James A.; Lawless, Sarah E.; Hart, Kerry A.; Hatton, Matthew Q.; Ireland, Rob H.

    2017-09-01

    To investigate the effect of beam angles and field number on functionally-guided intensity modulated radiotherapy (IMRT) normal lung avoidance treatment plans that incorporate hyperpolarised helium-3 magnetic resonance imaging (3He MRI) ventilation data. Eight non-small cell lung cancer patients had pre-treatment 3He MRI that was registered to inspiration breath-hold radiotherapy planning computed tomography. IMRT plans that minimised the volume of total lung receiving  ⩾20 Gy (V20) were compared with plans that minimised 3He MRI defined functional lung receiving  ⩾20 Gy (fV20). Coplanar IMRT plans using 5-field manually optimised beam angles and 9-field equidistant plans were also evaluated. For each pair of plans, the Wilcoxon signed ranks test was used to compare fV20 and the percentage of planning target volume (PTV) receiving 90% of the prescription dose (PTV90). Incorporation of 3He MRI led to median reductions in fV20 of 1.3% (range: 0.2-9.3% p  =  0.04) and 0.2% (range: 0 to 4.1%; p  =  0.012) for 5- and 9-field arrangements, respectively. There was no clinically significant difference in target coverage. Functionally-guided IMRT plans incorporating hyperpolarised 3He MRI information can reduce the dose received by ventilated lung without comprising PTV coverage. The effect was greater for optimised beam angles rather than uniformly spaced fields.

  15. 2001-2011

    DEFF Research Database (Denmark)

    Poggesi, Anna; Pantoni, Leonardo; Inzitari, Domenico

    2011-01-01

    study has also contributed more focused substudies assessing the possible role of WMC in the decline of cognitive and motor performances, depressive symptoms associated with aging and cerebrovascular diseases, urinary disturbances, and also the role of other brain lesions (lacunar infarcts, cerebral...

  16. Texture analysis and classification of SAR images of urban areas

    NARCIS (Netherlands)

    Dekker, R.J.

    2003-01-01

    In SAR image classification texture holds useful information. In a study after the ability of texture to discriminate urban land-cover, a set of measures was investigated. Among them were histogram measures, wavelet energy, fractal dimension, lacunarity and semivariograms. The latter were chosen as

  17. Cerebral Microbleeds and White Matter Hyperintensities in Cognitively Healthy Elderly: A Cross-Sectional Cohort Study Evaluating the Effect of Arterial Stiffness

    Directory of Open Access Journals (Sweden)

    Anna-Märta Gustavsson

    2015-05-01

    Full Text Available Background: Arterial stiffness reflects the ageing processes in the vascular system, and studies have shown an association between reduced cognitive function and cerebral small vessel disease. Small vessel disease can be visualized as white matter hyperintensities (WMH and lacunar infarcts but also as cerebral microbleeds on brain magnetic resonance imaging (MRI. We aimed to investigate if arterial stiffness influences the presence of microbleeds, WMH and cognitive function in a population of cognitively healthy elderly. Methods: The study population is part of the Swedish BioFinder study and consisted of 208 individuals without any symptoms of cognitive impairment, who scored >27 points on the Mini-Mental State Examination. The participants (mean age, 72 years; 59% women underwent MRI of the brain with visual rating of microbleeds and WMH. Arterial stiffness was measured with carotid-femoral pulse wave velocity (cfPWV. Eight cognitive tests covering different cognitive domains were performed. Results: Microbleeds were detected in 12% and WMH in 31% of the participants. Mean (±standard deviation, SD cfPWV was 10.0 (±2.0 m/s. There was no association between the presence of microbleeds and arterial stiffness. There was a positive association between arterial stiffness and WMH independent of age or sex (odds ratio, 1.58; 95% confidence interval, 1.04-2.40, p 0.05. Cognitive performance was not associated with microbleeds, but individuals with WMH performed slightly worse than those without WMH on the Symbol Digit Modalities Test (mean ± SD, 35 ± 7.8 vs. 39 ± 8.1, p Conclusions: Arterial stiffness was not associated with the presence of cerebral microbleeds or cognitive function in cognitively healthy elderly. However, arterial stiffness was related to the presence of WMH, but the association was attenuated when multiple adjustments were made. There was a weak negative association between WMH and performance in one specific test of attention

  18. Change over time in brain computed tomographic and magnetic resonance imaging findings in healthy elderly persons. A 10 year prospective study

    Energy Technology Data Exchange (ETDEWEB)

    Kasahara, Hiroo [Jikei Univ., Tokyo (Japan). School of Medicine

    1998-09-01

    Early detection, treatment and prevention of dementia have become increasingly important as the population ages. I have performed a follow-up study of changes in the brains of healthy elderly persons with computed tomography (CT) and magnetic resonance imaging (MRI) since 1982. One hundred thirty-three healthy elderly volunteers were first examined in 1982 with CT or MRI, electroencephalography, the Benton Visual Retention Test (BVRT), blood pressure measurement, and interview. Subsequent examinations were done in 1986, 1989, and 1992. On CT, microinfarctions were found in 15.0% of subjects in 1982 and in 13.0% in 1986, and periventricular lucency (PVL) was found in 6.0% and 8.3%. The most frequent findings were vascular changes, which were observed in six persons (5.6%), followed by PVL, which was found in four persons (3.7%). Thus, vascular changes became more pronounced during the follow-up period. Lesions with high signal intensity on T{sub 2}-weighted images (T{sub 2}HSI) were found in 69.5% of subjects and increased in prevalence with age in the 1989 study. Such T{sub 2}HSI lesions were found most frequently in the basal ganglia (61.9%), followed by the thalamus (39.0%), parietal lobe (37.0%), temporal lobe (12.7%), and the pons (8.5%). Of these lesions, lacunar infarctions showed low signal intensity on T{sub 1}-weighted images and were found in 24.6% of subjects; their prevalence also increased with age. Results of BVRT were closely correlated with T{sub 2}HSI lesions, suggesting that T{sub 2}HSIs lesions may affect cognitive function. By 1992, 10 years after the start of the study, 34 (25.6%) of subjects had died and 19 (14.3%) had become demented. Subjects were divided into surviving and dead groups and dementia and non-dementia groups. Findings on CT and BVRT in this study have provided clear clinical indices of death and dementia, especially maximal width of third ventricule in impairment of the diagnosis of dementia. (author)

  19. Land-Use and Land-Cover Mapping Using a Gradable Classification Method

    Directory of Open Access Journals (Sweden)

    Keigo Kitada

    2012-05-01

    Full Text Available Conventional spectral-based classification methods have significant limitations in the digital classification of urban land-use and land-cover classes from high-resolution remotely sensed data because of the lack of consideration given to the spatial properties of images. To recognize the complex distribution of urban features in high-resolution image data, texture information consisting of a group of pixels should be considered. Lacunarity is an index used to characterize different texture appearances. It is often reported that the land-use and land-cover in urban areas can be effectively classified using the lacunarity index with high-resolution images. However, the applicability of the maximum-likelihood approach for hybrid analysis has not been reported. A more effective approach that employs the original spectral data and lacunarity index can be expected to improve the accuracy of the classification. A new classification procedure referred to as “gradable classification method” is proposed in this study. This method improves the classification accuracy in incremental steps. The proposed classification approach integrates several classification maps created from original images and lacunarity maps, which consist of lacnarity values, to create a new classification map. The results of this study confirm the suitability of the gradable classification approach, which produced a higher overall accuracy (68% and kappa coefficient (0.64 than those (65% and 0.60, respectively obtained with the maximum-likelihood approach.

  20. 3D porous architecture of stacks of β-TCP granules compared with that of trabecular bone: a microCT, vector analysis and compression study

    Directory of Open Access Journals (Sweden)

    Daniel eCHAPPARD

    2015-10-01

    Full Text Available The 3D arrangement of porous granular biomaterials usable to fill bone defects has received little study. Granular biomaterials occupy 3D space when packed together in a manner that creates a porosity suitable for the invasion of vascular and bone cells. Granules of β-TCP were prepared with either 12.5 or 25g of β-TCP powder in the same volume of slurry. When the granules were placed in a test tube, this produced 3D stacks with a high (HP or low porosity (LP, respectively. Stacks of granules mimic the filling of a bone defect by a surgeon. The aim of this study was to compare the porosity of stacks of β-TCP granules with that of cores of trabecular bone. Biomechanical compression tests were done on the granules stacks. Bone cylinders were prepared from calf tibia plateau, constituted high density (HD blocks. Low density (LD blocks were harvested from aged cadaver tibias. Microcomputed tomography was used on the β-TCP granule stacks and the trabecular bone cores to determine porosity and specific surface. A vector projection algorithm was used to image porosity employing a frontal plane image which was constructed line by line from all images of a microCT stack. Stacks of HP granules had porosity (75.3 ± 0.4% and fractal lacunarity (0.043 ± 0.007 intermediate between that of HD (resp. 69.1 ± 6.4%, p<0.05 and 0.087 ± 0.045, p<0.05 and LD bones (resp. 88.8 ± 1.57% and 0.037 ± 0.014 but exhibited a higher surface density (5.56 ± 0.11 mm2/mm3 vs. 2.06 ± 0.26 for LD, p<0.05. LP granular arrangements created large pores coexisting with dense areas of material. Frontal plane analysis evidenced a more regular arrangement of β-TCP granules than bone trabeculae. Stacks of HP granules represent a scaffold that resembles trabecular bone in its porous microarchitecture.

  1. 3D Porous Architecture of Stacks of β-TCP Granules Compared with That of Trabecular Bone: A microCT, Vector Analysis, and Compression Study

    Science.gov (United States)

    Chappard, Daniel; Terranova, Lisa; Mallet, Romain; Mercier, Philippe

    2015-01-01

    The 3D arrangement of porous granular biomaterials usable to fill bone defects has received little study. Granular biomaterials occupy 3D space when packed together in a manner that creates a porosity suitable for the invasion of vascular and bone cells. Granules of beta-tricalcium phosphate (β-TCP) were prepared with either 12.5 or 25 g of β-TCP powder in the same volume of slurry. When the granules were placed in a test tube, this produced 3D stacks with a high (HP) or low porosity (LP), respectively. Stacks of granules mimic the filling of a bone defect by a surgeon. The aim of this study was to compare the porosity of stacks of β-TCP granules with that of cores of trabecular bone. Biomechanical compression tests were done on the granules stacks. Bone cylinders were prepared from calf tibia plateau, constituted high-density (HD) blocks. Low-density (LD) blocks were harvested from aged cadaver tibias. Microcomputed tomography was used on the β-TCP granule stacks and the trabecular bone cores to determine porosity and specific surface. A vector-projection algorithm was used to image porosity employing a frontal plane image, which was constructed line by line from all images of a microCT stack. Stacks of HP granules had porosity (75.3 ± 0.4%) and fractal lacunarity (0.043 ± 0.007) intermediate between that of HD (respectively 69.1 ± 6.4%, p < 0.05 and 0.087 ± 0.045, p < 0.05) and LD bones (respectively 88.8 ± 1.57% and 0.037 ± 0.014), but exhibited a higher surface density (5.56 ± 0.11 mm2/mm3 vs. 2.06 ± 0.26 for LD, p < 0.05). LP granular arrangements created large pores coexisting with dense areas of material. Frontal plane analysis evidenced a more regular arrangement of β-TCP granules than bone trabecule. Stacks of HP granules represent a scaffold that resembles trabecular bone in its porous microarchitecture. PMID:26528240

  2. Relation of cerebral small-vessel disease and brain atrophy to mild Parkinsonism in the elderly.

    Science.gov (United States)

    Reitz, Christiane; Trenkwalder, Claudia; Kretzschmar, Konrad; Roesler, Andreas; V Eckardstein, Arnold; Berger, Klaus

    2006-11-01

    The association between cerebral small-vessel disease, brain atrophy, and the risk and severity of mild parkinsonian signs (MPS) remains unclear. The objective of this study is to examine the effect of lacunar brain infarcts, cerebral white matter lesions (WMLs), and cortical atrophy on the risk and severity of MPS. This study is a cross-sectional community-based cohort study comprising 268 subjects, 65 to 83 years of age, residing in the Augsburg region of southern Germany, and without contraindications for magnetic resonance imaging (MRI) of the brain. Main outcome measures. Subcortical and periventricular WMLs, lacunar brain infarcts, and cortical atrophy determined using a standardized MRI protocol developed for the Rotterdam Scan Study and an established rating scale. MPS, assessed in a standardized neurological examination and based on the Unified Parkinson's Disease Rating Scale motor scale. Lacunar brain infarcts and large subcortical white matter lesions were associated with an elevated risk of resting tremor. More severe cortical atrophy was related to an increased risk of rigidity and bradykinesia. In a linear regression analysis relating each individual MRI measurement with the severity of MPS, the number of lacunar brain infarcts and the degree of brain atrophy were correlated with the severity of resting tremor, whereas the size of subcortical and periventricular WMLs was correlated with the severity of rigidity. A higher degree of brain atrophy was associated with increased severity of either cardinal sign. In our study, presence and volume of lacunar brain infarcts, cerebral WMLs, and cortical atrophy were associated with the risk as well as severity of MPS. Determining the presence of these brain changes using brain imaging might contribute to identify persons at risk for MPS.

  3. Impact of Non-Invasively Induced Motor Deficits on Tibial Cortical Properties in Mutant Lurcher Mice.

    Directory of Open Access Journals (Sweden)

    Alena Jindrová

    Full Text Available It has been shown that Lurcher mutant mice have significantly altered motor abilities, regarding their motor coordination and muscular strength because of olivorecebellar degeneration. We assessed the response of the cross-sectional geometry and lacuno-canalicular network properties of the tibial mid-diaphyseal cortical bone to motor differences between Lurcher and wild-type (WT male mice from the B6CBA strain. The first data set used in the cross-sectional geometry analysis consists of 16 mice of 4 months of age and 32 mice of 9 months of age. The second data set used in the lacunar-canalicular network analysis consists of 10 mice of 4 months of age. We compared two cross-sectional geometry and four lacunar-canalicular properties by I-region using the maximum and minimum second moment of area and anatomical orientation as well as H-regions using histological differences within a cross section. We identified inconsistent differences in the studied cross-sectional geometry properties between Lurcher and WT mice. The biggest significant difference between Lurcher and WT mice is found in the number of canaliculi, whereas in the other studied properties are only limited. Lurcher mice exhibit an increased number of canaliculi (p < 0.01 in all studied regions compared with the WT controls. The number of canaliculi is also negatively correlated with the distance from the centroid in the Lurcher and positively correlated in the WT mice. When the Lurcher and WT sample is pooled, the number of canaliculi and lacunar volume is increased in the posterior Imax region, and in addition, midcortical H-region exhibit lower number of canaliculi, lacuna to lacuna distance and increased lacunar volume. Our results indicate, that the importance of precise sample selection within cross sections in future studies is highlighted because of the histological heterogeneity of lacunar-canalicular network properties within the I-region and H-region in the mouse cortical

  4. Biocomplexity and Fractality in the Search of Biomarkers of Aging and Pathology: Focus on Mitochondrial DNA and Alzheimer’s Disease

    Science.gov (United States)

    Zaia, Annamaria; Maponi, Pierluigi; Di Stefano, Giuseppina; Casoli, Tiziana

    2017-01-01

    Alzheimer’s disease (AD) represents one major health concern for our growing elderly population. It accounts for increasing impairment of cognitive capacity followed by loss of executive function in late stage. AD pathogenesis is multifaceted and difficult to pinpoint, and understanding AD etiology will be critical to effectively diagnose and treat the disease. An interesting hypothesis concerning AD development postulates a cause-effect relationship between accumulation of mitochondrial DNA (mtDNA) mutations and neurodegenerative changes associated with this pathology. Here we propose a computerized method for an easy and fast mtDNA mutations-based characterization of AD. The method has been built taking into account the complexity of living being and fractal properties of many anatomic and physiologic structures, including mtDNA. Dealing with mtDNA mutations as gaps in the nucleotide sequence, fractal lacunarity appears a suitable tool to differentiate between aging and AD. Therefore, Chaos Game Representation method has been used to display DNA fractal properties after adapting the algorithm to visualize also heteroplasmic mutations. Parameter β from our fractal lacunarity method, based on hyperbola model function, has been measured to quantitatively characterize AD on the basis of mtDNA mutations. Results from this pilot study to develop the method show that fractal lacunarity parameter β of mtDNA is statistically different in AD patients when compared to age-matched controls. Fractal lacunarity analysis represents a useful tool to analyze mtDNA mutations. Lacunarity parameter β is able to characterize individual mutation profile of mitochondrial genome and appears a promising index to discriminate between AD and aging. PMID:28197358

  5. Biocomplexity and Fractality in the Search of Biomarkers of Aging and Pathology: Focus on Mitochondrial DNA and Alzheimer's Disease.

    Science.gov (United States)

    Zaia, Annamaria; Maponi, Pierluigi; Di Stefano, Giuseppina; Casoli, Tiziana

    2017-02-01

    Alzheimer's disease (AD) represents one major health concern for our growing elderly population. It accounts for increasing impairment of cognitive capacity followed by loss of executive function in late stage. AD pathogenesis is multifaceted and difficult to pinpoint, and understanding AD etiology will be critical to effectively diagnose and treat the disease. An interesting hypothesis concerning AD development postulates a cause-effect relationship between accumulation of mitochondrial DNA (mtDNA) mutations and neurodegenerative changes associated with this pathology. Here we propose a computerized method for an easy and fast mtDNA mutations-based characterization of AD. The method has been built taking into account the complexity of living being and fractal properties of many anatomic and physiologic structures, including mtDNA. Dealing with mtDNA mutations as gaps in the nucleotide sequence, fractal lacunarity appears a suitable tool to differentiate between aging and AD. Therefore, Chaos Game Representation method has been used to display DNA fractal properties after adapting the algorithm to visualize also heteroplasmic mutations. Parameter β from our fractal lacunarity method, based on hyperbola model function, has been measured to quantitatively characterize AD on the basis of mtDNA mutations. Results from this pilot study to develop the method show that fractal lacunarity parameter β of mtDNA is statistically different in AD patients when compared to age-matched controls. Fractal lacunarity analysis represents a useful tool to analyze mtDNA mutations. Lacunarity parameter β is able to characterize individual mutation profile of mitochondrial genome and appears a promising index to discriminate between AD and aging.

  6. Marked pericardial inhomogeneity of specific ventilation at total lung capacity and beyond

    DEFF Research Database (Denmark)

    Sun, Yanping; Butler, James P; Lindholm, Peter

    2009-01-01

    We measured regional ventilation at 1l above functional residual capacity (FRC+1L) and total lung capacity (TLC) in three normal subjects and four elite breath-hold divers, and above TLC after glossopharyngeal insufflation (TLC+GI) in the divers. Hyperpolarized (3)He MRI was used to map the local...

  7. Cognitive Function and Emotional Status of Middle-aged Chinese Hypertensive Patients Without Detectable White Matter Brain Lesions or Lacunar Infarctions

    Science.gov (United States)

    2006-01-01

    According to Baron & Kenny (1986), a significant interaction term signals a moderator of the relationship between EH and the specific cognitive ability...implications for cognition. J Cardiovasc Pharmacol, 16(2), 234-238. Baron , R. M., & Kenny , D. A. (1986). The moderator-mediator variable...The present results may not be generalizable beyond Chinese living in China with hypertension. In addition, self-report questionnaires were used

  8. Cognitive Function and Emotional Status of Middle-aged Chinese Hypertensive Patients Without Detectable White Matter Brain Lesions or Lacunar Infarctions

    Science.gov (United States)

    2006-08-30

    improved nor worsened cognitive function. Although there were no initial changes in cognitive function after beta-blocker administration, propranolol ...function (Barnes et al., 1990). Angiotensin-I metabolism may then be activated by alternate pathways, which would increase the synthesis of

  9. 285例腔隙性脑梗死临床病因分析%Analysis on Clinical Causa Morbi of Lacunar Cerebral Infarction

    Institute of Scientific and Technical Information of China (English)

    葛萱; 葛敦钧

    2006-01-01

    [目的]探讨腔隙性脑梗死的发病原因及治疗.[方法]对285例腔隙性脑梗死患者给予胞二磷胆碱、葛根素治疗,对合并基础疾病的患者同时给予对症治疗.[结果]显效206例,好转79例,无1例死亡.[结论]积极治疗基础疾病可以有效预防和减少脑血管疾病的危险因素,避免腔隙性脑梗死的发生和再发生.

  10. Characterization and classification of tumor lesions using computerized fractal-based texture analysis and support vector machines in digital mammograms.

    Science.gov (United States)

    Guo, Qi; Shao, Jiaqing; Ruiz, Virginie F

    2009-01-01

    This paper presents a detailed study of fractal-based methods for texture characterization of mammographic mass lesions and architectural distortion. The purpose of this study is to explore the use of fractal and lacunarity analysis for the characterization and classification of both tumor lesions and normal breast parenchyma in mammography. We conducted comparative evaluations of five popular fractal dimension estimation methods for the characterization of the texture of mass lesions and architectural distortion. We applied the concept of lacunarity to the description of the spatial distribution of the pixel intensities in mammographic images. These methods were tested with a set of 57 breast masses and 60 normal breast parenchyma (dataset1), and with another set of 19 architectural distortions and 41 normal breast parenchyma (dataset2). Support vector machines (SVM) were used as a pattern classification method for tumor classification. Experimental results showed that the fractal dimension of region of interest (ROIs) depicting mass lesions and architectural distortion was statistically significantly lower than that of normal breast parenchyma for all five methods. Receiver operating characteristic (ROC) analysis showed that fractional Brownian motion (FBM) method generated the highest area under ROC curve (A ( z ) = 0.839 for dataset1, 0.828 for dataset2, respectively) among five methods for both datasets. Lacunarity analysis showed that the ROIs depicting mass lesions and architectural distortion had higher lacunarities than those of ROIs depicting normal breast parenchyma. The combination of FBM fractal dimension and lacunarity yielded the highest A ( z ) value (0.903 and 0.875, respectively) than those based on single feature alone for both given datasets. The application of the SVM improved the performance of the fractal-based features in differentiating tumor lesions from normal breast parenchyma by generating higher A ( z ) value. FBM texture model is the

  11. Determining Scale-dependent Patterns in Spatial and Temporal Datasets

    Science.gov (United States)

    Roy, A.; Perfect, E.; Mukerji, T.; Sylvester, L.

    2016-12-01

    Spatial and temporal datasets of interest to Earth scientists often contain plots of one variable against another, e.g., rainfall magnitude vs. time or fracture aperture vs. spacing. Such data, comprised of distributions of events along a transect / timeline along with their magnitudes, can display persistent or antipersistent trends, as well as random behavior, that may contain signatures of underlying physical processes. Lacunarity is a technique that was originally developed for multiscale analysis of data. In a recent study we showed that lacunarity can be used for revealing changes in scale-dependent patterns in fracture spacing data. Here we present a further improvement in our technique, with lacunarity applied to various non-binary datasets comprised of event spacings and magnitudes. We test our technique on a set of four synthetic datasets, three of which are based on an autoregressive model and have magnitudes at every point along the "timeline" thus representing antipersistent, persistent, and random trends. The fourth dataset is made up of five clusters of events, each containing a set of random magnitudes. The concept of lacunarity ratio, LR, is introduced; this is the lacunarity of a given dataset normalized to the lacunarity of its random counterpart. It is demonstrated that LR can successfully delineate scale-dependent changes in terms of antipersistence and persistence in the synthetic datasets. This technique is then applied to three different types of data: a hundred-year rainfall record from Knoxville, TN, USA, a set of varved sediments from Marca Shale, and a set of fracture aperture and spacing data from NE Mexico. While the rainfall data and varved sediments both appear to be persistent at small scales, at larger scales they both become random. On the other hand, the fracture data shows antipersistence at small scale (within cluster) and random behavior at large scales. Such differences in behavior with respect to scale-dependent changes in

  12. Cerebral microbleeds in patients with mild cognitive impairment and small vessel disease: The Vascular Mild Cognitive Impairment (VMCI)-Tuscany study.

    Science.gov (United States)

    Valenti, Raffaella; Del Bene, Alessandra; Poggesi, Anna; Ginestroni, Andrea; Salvadori, Emilia; Pracucci, Giovanni; Ciolli, Laura; Marini, Sandro; Nannucci, Serena; Pasi, Marco; Pescini, Francesca; Diciotti, Stefano; Orlandi, Giovanni; Cosottini, Mirco; Chiti, Alberto; Mascalchi, Mario; Bonuccelli, Ubaldo; Inzitari, Domenico; Pantoni, Leonardo

    2016-09-15

    Cerebral microbleeds (CMBs) are a neuroimaging expression of small vessel disease (SVD). We investigated in a cohort of SVD patients with mild cognitive impairment (MCI): 1) the reliability of the Microbleed Anatomical Rating Scale (MARS); 2) the burden and location of CMBs and their association with cognitive performances, independent of other clinical and neuroimaging features. Patients underwent clinical, neuropsychological (4 cognitive domains), and MRI assessments. CMBs were assessed by three raters. Out of the 152 patients (57.2% males; mean age±SD: 75.5±6.7years) with gradient-echo (GRE) sequences, 41 (27%) had at least one CMB. Inter-rater agreement for number and location of CMBs ranged from good to very good [multi-rater Fleiss kappa (95%CI): 0.70-0.95]. Lacunar infarcts and some clinical variables (e.g., hypertension and physical activity) were associated with CMBs in specific regions. Total number of CMBs and of those in deep and lobar regions were associated with attention/executive and fluency domains. MARS is a reliable instrument to assess CMBs in SVD patients with MCI. Nearly one third of these patients had at least one CMB. Total CMBs burden was associated with attention/executive functions and fluency domains impairment, lacunar infarcts, and with some potentially modifiable risk factors. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Leaf anatomy of Gaillardia cabrerae (Asteraceae: Basic plan and comparative study of two contrasting habitat populations Anatomía foliar de Gaillardia cabrerae (Asteraceae: plan básico y estudio comparativo de dos poblaciones de hábitats contrastantes

    Directory of Open Access Journals (Sweden)

    Laura Beinticinco

    2011-06-01

    Full Text Available This study evaluates the leaf anatomy pattern of Gaillardia cabrerae Covas, an exclusive endemic camephyte from the Lihué Calel National Park, province of La Pampa, Argentina. Leaf cross sections and peelings of plants growing in two different populations were used to determine the basic leaf anatomy patterns and to estimate the influence of growth conditions in the two microhabitats. The analysis showed differences in epidermal cells area, stomata density and main diameter, lacunar parenchyma cells and central vascular bundle diameter and palisade parenchyma cells dimensions. These aspects might be reflecting environmental conditions of the populations, especially sun exposure and soil moisture. The results provide information on the relationship of the species to its environment, which could be used in the establishment of conservation policies.Gaillardia cabrerae Covas es un caméfito endémico del Parque Nacional Lihué Calel. En este estudio se evalúan características anatómicas de individuos de dos poblaciones provenientes de diferentes microhábitats de las Sierras de Lihué Calel. La información proporcionada es importante para entender las condiciones de vida de la especie y provee información inherente para establecer planes de conservación. Mediante cortes transversales y la técnica de peeling fue posible determinar el plan básico de la anatomía foliar y también verificar diferencias significativas en el área de células epidérmicas, densidad estomática, diámetro mayor de los estomas, diámetro de células del parénquima lagunar y del haz vascular central y en las dimensiones de las células del parénquima en empalizada. Las condiciones ambientales a las cuales estas poblaciones están sometidas, especialmente la exposición solar y la humedad del suelo son posibles factores que podrían explicar las diferencias detectadas en la anatomía foliar para ambas poblaciones.

  14. Automatic Method to Classify Images Based on Multiscale Fractal Descriptors and Paraconsistent Logic

    Science.gov (United States)

    Pavarino, E.; Neves, L. A.; Nascimento, M. Z.; Godoy, M. F.; Arruda, P. F.; Neto, D. S.

    2015-01-01

    In this study is presented an automatic method to classify images from fractal descriptors as decision rules, such as multiscale fractal dimension and lacunarity. The proposed methodology was divided in three steps: quantification of the regions of interest with fractal dimension and lacunarity, techniques under a multiscale approach; definition of reference patterns, which are the limits of each studied group; and, classification of each group, considering the combination of the reference patterns with signals maximization (an approach commonly considered in paraconsistent logic). The proposed method was used to classify histological prostatic images, aiming the diagnostic of prostate cancer. The accuracy levels were important, overcoming those obtained with Support Vector Machine (SVM) and Best- first Decicion Tree (BFTree) classifiers. The proposed approach allows recognize and classify patterns, offering the advantage of giving comprehensive results to the specialists.

  15. Brain CT-scan in acute stroke patients: silent infarcts and relation to outcome.

    Science.gov (United States)

    Corea, Francesco; Tambasco, Nicola; Luccioli, Roberto; Ciorba, Ettore; Parnetti, Lucilla; Gallai, Virgilio

    2002-01-01

    Silent infarcts (SIs) are common findings in stroke patients, but their clinical significance remains controversial. Aim of this study was to evaluate the prevalence of SI in consecutive stroke patients, characteristics, associated factors, and influence on in-hospital mortality. The population consisted of 191 patients, consecutively admitted for an acute stroke. Of 191 patients, 74 had SI on CT-scan. Silent infarcts were often multiple, right sided, lacunar. We found SI more frequently in older patients, smokers, with an ischemic stroke having small vessel disease as presumed cause. In our study SI were associated with ageing, smoke habit and lacunar stroke. Silent infarcts size influenced the rate of in-hospital mortality.

  16. Clinical and imaging features associated with an increased risk of early and late stroke in patients with symptomatic carotid disease

    DEFF Research Database (Denmark)

    Naylor, A R; Sillesen, H; Schroeder, T V

    2015-01-01

    OBJECTIVE: The aim of this review was to identify clinical and/or imaging parameters that are associated with an increased (decreased) risk of early/late stroke in patients with symptomatic carotid disease. IN THE FIRST 14 DAYS: Natural history studies suggest that 8-15% of patients with 50-99% s...... (i) female gender, especially those with 50-99% stenoses; (ii) ocular symptoms/lacunar stroke; (iii) smooth stenoses; and (iv) chronic subocclusion....

  17. Subtypes of ischemic cerebral circulation disorders at young age: diagnosis and treatment

    OpenAIRE

    Natalia Vyacheslavovna Pizova

    2012-01-01

    The paper shows that it is urgent to study stroke in young patients aged 15—45 years. In accordance with the TOAST classification, the author presents the major pathogenetic subtypes of ischemic stroke (IS): atherothromboembolic, cardioembolic, lacunar, that of other known and unknown etiology. The clinical picture and diagnostic principles of IS at young age are considered. Particular emphasis is laid on therapy for IS. It is pointed out that the leading therapy option in these patients is t...

  18. Microstructure and compressive mechanical properties of cortical bone in children with osteogenesis imperfecta treated with bisphosphonates compared with healthy children.

    Science.gov (United States)

    Imbert, Laurianne; Aurégan, Jean-Charles; Pernelle, Kélig; Hoc, Thierry

    2015-06-01

    Osteogenesis imperfecta (OI) is a genetic disorder characterized by a change in bone tissue quality, but little data are available to describe the factors involved at the macroscopic scale. To better understand the effect of microstructure alterations on the mechanical properties at the sample scale, we studied the structural and mechanical properties of six cortical bone samples from children with OI treated with bisphosphonates and compared them to the properties of three controls. Scanning electron microscopy, high resolution computed tomography and compression testing were used to assess these properties. More resorption cavities and a higher osteocyte lacunar density were observed in OI bone compared with controls. Moreover, a higher porosity was measured for OI bones along with lower macroscopic Young's modulus, yield stress and ultimate stress. The microstructure was impaired in OI bones; the higher porosity and osteocyte lacunar density negatively impacted the mechanical properties and made the bone more prone to fracture.

  19. Bipolar Disorder after Stroke in an Elderly Patient

    Directory of Open Access Journals (Sweden)

    Raquel Calvão de Melo

    2014-01-01

    Full Text Available The onset of bipolar disorder (BD secondary to a stroke event is a rare clinical entity. Although it may be related to specific regions of the brain, several other factors have been linked to its expression such as subcortical atrophy or chronic vascular burden. While precise locations and cerebral circuits involved in the bipolarity expression after stroke still need to be determined, their investigation represents an opportunity to study brain function and BD etiopathogenesis. We present a BD secondary to multiple subcortical biparietal lacunar infarctions, a lacunar infarction in left putamen and an ischemic lesion at the cerebral trunk evolving the right median portion, in a 65-year-old male patient who experienced manic, hypomanic, and depressive episodes, after 6, 10, and 16 months, respectively, of the cerebrovascular events.

  20. Evaluation of geometric features as biomarkers of diabetic retinopathy for characterizing the retinal vascular changes during the progression of diabetes.

    Science.gov (United States)

    Leontidis, Georgios; Al-Diri, Bashir; Wigdahl, Jeffrey; Hunter, Andrew

    2015-01-01

    Diabetic retinopathy (DR) has been widely studied and characterized. However, until now, it is unclear how different features, extracted from the retinal vasculature, can be associated with the progression of diabetes and therefore become biomarkers of DR. In this study, a comprehensive analysis is presented, in which four groups were created, using eighty fundus images from twenty patients, who have progressed to DR and they had no history of any other diseases (e.g. hypertension or glaucoma). The significance of the following features was evaluated: widths, angles, branching coefficient (BC), angle-to-BC ratio, standard deviations, means and medians of widths and angles, fractal dimension (FD), lacunarity and FD-to-lacunarity ratio, using a mixed model analysis of variance (ANOVA) design. All the features were measured from the same junctions of each patient, using an automated tool. The discriminative power of these features was evaluated, using decision trees and random forests classifiers. Cross validation and out-of-bag error were used to evaluate the classifiers' performance, calculating the area under the ROC curve (AUC) and the classification error. Widths, FD and FD-to-Lacunarity ratio were found to differ significantly. Random forests had a superior performance of 0.768 and 0.737 in the AUC for the two cases of classification, namely three-years-pre-DR/post-DR and two-years-pre-DR/post-DR respectively.

  1. Relationships between personality traits, medial temporal lobe atrophy and white matter lesion in subjects suffering from mild cognitive impairment

    Directory of Open Access Journals (Sweden)

    Emmanuelle eDuron

    2014-07-01

    Full Text Available Mild Cognitive Impairment (MCI is a heterogeneous cognitive status that can be a prodromal stage of Alzheimer‘s disease (AD. It is particularly relevant to focus on prodromal stages of AD such as MCI, because pathophysiological abnormalities of AD start years before the dementia stage. Medial temporal lobe atrophy (MTL resulting from AD lesions and cerebrovascular lesions (i.e. white matter lesions (WML, lacunar strokes and strokes are often revealed concurrently on Magnetic Resonance Imaging (MRI in MCI subjects. Personality changes have been reported to be associated with MCI status and early AD. More specifically, an increase in neuroticism and a decrease in conscientiousness have been reported, suggesting that higher and lower scores, respectively in neuroticism and conscientiousness are associated with an increased risk of developing the disease. However, personality changes have not been studied concomitantly with pathological structural brain alterations detected on MRI in patients suffering from MCI. Therefore, the objective of the present study was to assess the relationship between MTL atrophy, WML, lacunar strokes and personality traits in such patients. The severity of WML was strongly associated with lower levels of conscientiousness and higher levels of neuroticism. Conversely, no association was detected between personality traits and the presence of lacunar strokes or MTL atrophy. Altogether, these results strongly suggest that personality changes occurring in a MCI population, at high risk of AD, are associated with WML, which can induce executive dysfunctions, rather than with MTL atrophy.

  2. Immunolocalization of loricrin in the maturing α-layer of normal and regenerating epidermis of the lizard Anolis carolinensis.

    Science.gov (United States)

    Alibardi, Lorenzo; Strasser, Bettina; Eckhart, Leopold

    2015-03-01

    Numerous corneous proteins are produced during the differentiation of the complex lizard epidermis, comprising hard β-layers and softer α-layers. In the present ultrastructural and immunocytochemical study, we have localized a homolog of the mammalian skin barrier protein loricrin in the skin of the green anole lizard (Anolis carolinensis). We used an antibody specific to the carboxyterminus of loricrin 1, a gene of the epidermal differentiation complex (EDC) of A. carolinensis. Lizard loricrin is present in the maturing α-layer (lacunar cells) of normal scale epidermis and in the accumulating corneocytes of the wound epidermis (lacunar cells) of the regenerating epidermis. The protein appears as a component of the α-layer but not of the β-layer. Lizard loricrin is diffused in the cytoplasm of pre-corneous α-keratinocytes but eventually concentrates in the packing corneous material of the maturing corneocytes of the α-layer (lacunar) in normal epidermis or in the wound epidermis of regenerating epidermis. The protein likely contributes to the composition and pliability of the corneous material but is not specifically accumulated on the corneous cell envelope (marginal layer) that is scarcely differentiated in these cells. The study contributes to the knowledge on the distribution of specific corneous proteins that give rise to the different material properties of α-layers versus β-layers in lizard epidermis.

  3. Relationships between Personality Traits, Medial Temporal Lobe Atrophy, and White Matter Lesion in Subjects Suffering from Mild Cognitive Impairment

    Science.gov (United States)

    Duron, Emmanuelle; Vidal, Jean-Sébastien; Bounatiro, Samira; Ben Ahmed, Sana; Seux, Marie-Laure; Rigaud, Anne-Sophie; Hanon, Olivier; Viollet, Cécile; Epelbaum, Jacques; Martel, Guillaume

    2014-01-01

    Mild cognitive impairment (MCI) is a heterogeneous cognitive status that can be a prodromal stage of Alzheimer’s disease (AD). It is particularly relevant to focus on prodromal stages of AD such as MCI, because patho-physiological abnormalities of AD start years before the dementia stage. Medial temporal lobe (MTL) atrophy resulting from AD lesions and cerebrovascular lesions [i.e., white matter lesions (WML), lacunar strokes, and strokes] are often revealed concurrently on magnetic resonance imaging (MRI) in MCI subjects. Personality changes have been reported to be associated with MCI status and early AD. More specifically, an increase in neuroticism and a decrease in conscientiousness have been reported, suggesting that higher and lower scores, respectively, in neuroticism and conscientiousness are associated with an increased risk of developing the disease. However, personality changes have not been studied concomitantly with pathological structural brain alterations detected on MRI in patients suffering from MCI. Therefore, the objective of the present study was to assess the relationship between MTL atrophy, WML, lacunar strokes, and personality traits in such patients. The severity of WML was strongly associated with lower levels of conscientiousness and higher levels of neuroticism. Conversely, no association was detected between personality traits and the presence of lacunar strokes or MTL atrophy. Altogether, these results strongly suggest that personality changes occurring in a MCI population, at high risk of AD, are associated with WML, which can induce executive dysfunctions, rather than with MTL atrophy. PMID:25120483

  4. A technique for revealing scale-dependent patterns in fracture spacing data

    Science.gov (United States)

    Roy, Ankur; Perfect, Edmund; Dunne, William M.; McKay, Larry D.

    2014-07-01

    Data on fracture spacing along scan lines have been widely analyzed for the purposes of characterization. Most of these studies, however, either consider the cumulative frequency of spacing data without regard to the actual sequence of the spacing values or compute an average spacing that may not work for clustered fractures. The coefficient of variation parameter is often used to differentiate between clustered, random, and anticlustered fractures in a scan line but does not address the issue of scale-dependent variations in spacing. Lacunarity is a parameter that has been previously used for delineating scale-dependent clustering in fracture networks with similar fractal dimensions. This technique has the further capability of identifying scales at which different patterns emerge within the same data set. Lacunarity can also delineate possible fractal behavior. This paper tests the ability of lacunarity to find patterns (fractal/uniform/random) within synthetic and natural fracture clusters. A set of four model scan lines (uniformly spaced fractures, periodically spaced fracture clusters, fractal fracture clusters, and random fractures) was considered. The first derivative of the lacunarity curves of these models was used to find the intercluster distance and organization of fractures within the clusters. The same technique was then applied to a set of two natural fracture scan line data, one with fracture clusters with fractal organization within and the other with randomly spaced fractures. It was found that the proposed technique could discriminate between the random and clustered patterns, find the intercluster distance, and identify the type of spatial organization within the clusters.

  5. Cerebral microbleeds are associated with worse cognitive function in the nondemented elderly with small vessel disease.

    Science.gov (United States)

    Yamashiro, Kazuo; Tanaka, Ryota; Okuma, Yasuyuki; Shimura, Hideki; Ueno, Yuji; Miyamoto, Nobukazu; Urabe, Takao; Hattori, Nobutaka

    2014-01-01

    Cerebral small vessel disease (SVD) is a leading cause of cognitive decline in the elderly. Cerebral microbleeds (CMBs) have emerged as an important manifestation of cerebral SVD, in addition to lacunar infarcts and white matter lesions (WMLs). We investigated whether the presence and location of CMBs in elderly subjects were associated with cognitive function, independent of lacunar infarcts and WMLs. One hundred and forty-eight nondemented elderly with SVD, defined as the presence of lacunar infarcts and/or WMLs on magnetic resonance imaging (MRI), were studied. Executive function and global cognition were assessed by the Frontal Assessment Battery (FAB) and Mini-Mental State Examination (MMSE), respectively. The differences in the scores for the FAB and MMSE between CMB-positive and CMB-negative subjects were calculated after adjusting for possible confounders. The mean age of the subjects was 72.4 ± 8.6 years. CMBs were detected in 48 subjects (32%), with a mean number of CMBs per subject of 1.6 (range 0-31). Among CMB-positive subjects, 42 (87.5%) had CMBs in deep or infratentorial regions with or without lobar CMBs, and 6 (12.5%) had CMBs in strictly lobar regions. The presence of CMBs was significantly associated with FAB and MMSE scores after adjustment for age, years of education, brain volume and the presence of lacunar infarcts (for the FAB) or severe WMLs (for the MMSE). The presence of CMBs in the basal ganglia, in the thalamus or in the lobar regions was associated with FAB scores, while that in the lobar regions was associated with MMSE scores. However, there was no association between CMBs in the infratentorial regions and cognitive parameters. In nondemented elderly with SVD on MRI, the presence of CMBs was independently associated with worse executive and global cognitive functions. CMBs seemed to reflect hypertensive microangiopathy in this population, and CMBs in specific areas may play an important role in cognitive function.

  6. Fractal analysis of the structural complexity of the connective tissue in human carotid bodies.

    Science.gov (United States)

    Guidolin, Diego; Porzionato, Andrea; Tortorella, Cinzia; Macchi, Veronica; De Caro, Raffaele

    2014-01-01

    The carotid body (CB) may undergo different structural changes during perinatal development, aging, or in response to environmental stimuli. In the previous literature, morphometric approaches to evaluate these changes have considered quantitative first order parameters, such as volumes or densities, while changes in spatial disposition and/or complexity of structural components have not yet been considered. In the present study, different strategies for addressing morphological complexity of CB, apart from the overall amount of each tissue component, were evaluated and compared. In particular, we considered the spatial distribution of connective tissue in the carotid bodies of young control subjects, young opiate-related deaths and aged subjects, through analysis of dispersion (Morisita's index), gray level co-occurrence matrix (entropy, angular second moment, variance, correlation), and fractal analysis (fractal dimension, lacunarity). Opiate-related deaths and aged subjects showed a comparable increase in connective tissue with respect to young controls. However, the Morisita's index (p lacunarity (p lacunarity, with areas under the ROC curve of 0.9651 (excellent accuracy) and 0.8835 (good accuracy), respectively, showed the highest discriminatory power. They evidenced higher level of structural complexity in the carotid bodies of opiate-related deaths than old controls, due to more complex branching of intralobular connective tissue. Further analyses will have to consider the suitability of these approaches to address other morphological features of the CB, such as different cell populations, vascularization, and innervation.

  7. Multifractal geometry in analysis and processing of digital retinal photographs for early diagnosis of human diabetic macular edema.

    Science.gov (United States)

    Tălu, Stefan

    2013-07-01

    The purpose of this paper is to determine a quantitative assessment of the human retinal vascular network architecture for patients with diabetic macular edema (DME). Multifractal geometry and lacunarity parameters are used in this study. A set of 10 segmented and skeletonized human retinal images, corresponding to both normal (five images) and DME states of the retina (five images), from the DRIVE database was analyzed using the Image J software. Statistical analyses were performed using Microsoft Office Excel 2003 and GraphPad InStat software. The human retinal vascular network architecture has a multifractal geometry. The average of generalized dimensions (Dq) for q = 0, 1, 2 of the normal images (segmented versions), is similar to the DME cases (segmented versions). The average of generalized dimensions (Dq) for q = 0, 1 of the normal images (skeletonized versions), is slightly greater than the DME cases (skeletonized versions). However, the average of D2 for the normal images (skeletonized versions) is similar to the DME images. The average of lacunarity parameter, Λ, for the normal images (segmented and skeletonized versions) is slightly lower than the corresponding values for DME images (segmented and skeletonized versions). The multifractal and lacunarity analysis provides a non-invasive predictive complementary tool for an early diagnosis of patients with DME.

  8. The canalicular system and the osteoblast domain in human secondary osteons.

    Science.gov (United States)

    Pazzaglia, U E; Congiu, T; Marchese, M; Zarattini, G; Dell'Orbo, C

    2012-12-01

    The lacunar-canalicular system in human secondary osteons was examined by two complementary techniques: light microscopy analysis of undecalcified thick sections and the SEM cortex-fractured surface technique. Unlike the earlier definitions of 'osteoblastic domain' presented as the matrix volume produced by osteoblasts in the process of osteon infilling, this study measured the domain by the length of osteoblast dendritic processes. The domain extension was defined along radial vectors advancing from the reversal line towards the central canal. According to their lengths, domains were divided into three classes: peripheral, intermediate and internal. The mean length of peripheral domains was significantly shorter than those of the intermediate and internal domains. This suggests that the infilling process is modulated by an initial preparatory phase characterised by osteoblast adhesion to the wall of the cutting cone, and a limited matrix synthesis, followed by a regular matrix volume apposition organised in concentric layers. In addition to the radial canaliculae arranged along converging vectors in planes perpendicular to the central canal, we distinguished a further class of canaliculae, the equatorial canaliculae originating from the major perimeter of the lacuna and spreading out radially in the plane of the same lacuna (therefore, perpendicularly to the radial canaliculae). The whole lacunar-canalicular network was structured as a closed system around the vascular axis of the central canal with very few canaliculae crossing the reversal line and connecting the neighbouring osteons. These anatomical observations contribute to our knowledge of lacunar-canalicular system development. © 2012 Blackwell Verlag GmbH.

  9. Evaluating differential nuclear DNA yield rates and osteocyte numbers among human bone tissue types: A synchrotron radiation micro-CT approach.

    Science.gov (United States)

    Andronowski, Janna M; Mundorff, Amy Z; Pratt, Isaac V; Davoren, Jon M; Cooper, David M L

    2017-05-01

    Molecular human identification has conventionally focused on DNA sampling from dense, weight-bearing cortical bone tissue, typically from femora or tibiae. A comparison of skeletal elements from three contemporary individuals demonstrated that elements with high quantities of cancellous bone yielded nuclear DNA at the highest rates, suggesting that preferentially sampling cortical bone may be suboptimal (Mundorff & Davoren, 2014). Despite these findings, the reason for the differential DNA yields between cortical and cancellous bone tissues remains unknown. The primary goal of this work is to ascertain whether differences in bone microstructure can be used to explain differential nuclear DNA yield among bone tissue types observed by Mundorff and Davoren (2014), with a focus on osteocytes and the three-dimensional (3D) quantification of their associated lacunae. Osteocytes and other bone cells are recognized to house DNA in bone tissue, thus examining the density of their lacunae may explain why nuclear DNA yield rates differ among bone tissue types. Lacunae were visualized and quantified using synchrotron radiation-based micro-Computed Tomographic imaging (SR micro-CT). Volumes of interest (VOIs) from cortical and cancellous bone tissues (n=129) were comparatively analyzed from the three skeletons sampled for Mundorff and Davoren's (2014) study. Analyses tested the primary hypothesis that the abundance and density of osteocytes (inferred from their lacunar spaces) vary between cortical and cancellous bone tissue types. Results demonstrated that osteocyte lacunar abundance and density vary between cortical and cancellous bone tissue types, with cortical bone VOIs containing a higher lacunar abundance and density. We found that the osteocyte lacunar density values are independent of nuclear DNA yield, suggesting an alternative explanation for the higher nuclear DNA yields from bones with greater quantities of cancellous bone tissue. The use of SR micro-CT allowed for

  10. Qualitative studies

    National Research Council Canada - National Science Library

    Qualitative Studies (QS) aims to become a central forum for discussions of qualitative research in psychology, education, communication, cultural studies, health sciences and social sciences in general...

  11. Biofeasibility Study.

    Science.gov (United States)

    Chaparian, Michael

    1995-01-01

    Discusses the use of bioremediation as a method for disposing of contaminants by exploiting natural biodegradation processes. The process of conducting a biofeasibility study and a case study are reviewed. (LZ)

  12. Studying Genes

    Science.gov (United States)

    ... NIGMS NIGMS Home > Science Education > Studying Genes Studying Genes Tagline (Optional) Middle/Main Content Area Other Fact Sheets What are genes? Genes are segments of DNA that contain instructions ...

  13. Study Drugs

    Science.gov (United States)

    ... study drugs: amphetamines like Adderall, Dexedrine, or Vyvanse methylphenidates like Ritalin or Concerta Most people get study ... How Much Sleep Do I Need? Prescription Drug Abuse How to Make Homework Less Work Organizing Schoolwork & ...

  14. Studying Zooarchaeology

    Science.gov (United States)

    Moore, Molly; Wolf, Deborah; Butler, Virginia L.

    2012-01-01

    Children often associate the study of bones with dinosaurs or crime scenes. This unit introduces students to "zooarchaeology," the study of animal remains from archaeological sites. Students in grades 3-5 engage in hands-on activities examining bones, shells, and other "hard parts" of animals. They use their observations as a starting point for…

  15. A controlled observation on depression and P300 potentials in 60 patients with lacunar infarct%腔隙性脑梗死60例抑郁情绪及P300电位的对照观察

    Institute of Scientific and Technical Information of China (English)

    张朝辉; 宋景贵; 王夏红; 穆俊林

    2006-01-01

    目的探讨腔隙性脑梗死(LI)患者的抑郁情绪和P300电位变化及其临床价值.方法对60例LI患者和59例健康者分别进行了P300电位测定和抑郁量表评定,并将2组结果加以比较.结果与对照组相比,LI组P300电位成分中N2、P3波潜伏期延长和P3波幅降低,其差异具有显著性(P<0.05或P<0.01).抑郁量表评定各因子分2组相比存在显著性差异(P<0.01).结论部分LI患者存在抑郁情绪和认知功能障碍,P300电位可作为评价其认知功能的指标应用于临床.

  16. 腔隙性脑梗死患者脑微出血与循环内皮微粒的相关性研究%Correlation between cerebral microbleeds and circulating endothelial microparticles in lacunar stroke patients

    Institute of Scientific and Technical Information of China (English)

    孔德燕

    2015-01-01

    目的 探讨腔隙性脑梗死患者脑微出血(CMB)与血浆内皮微粒(EMP)的关系.方法 选择首次发病3个月后的腔隙性脑梗死患者84例,根据磁敏感检测结果分为CMB组33例和无CMB组51例,收集2组患者的临床基线资料,并通过流式细胞仪检测其血浆CD31+/CD42-EMP水平.结果 CMB组EMP水平明显高于无CMB组[(451.93±94.46)×106/Lvs (310.93±55.47)×106/L,P=0.000].CMB严重程度与EMP呈正相关(r=0.817,P=0.000).二分类logistic回归分析显示,在控制了年龄、高血压、纤维蛋白原等混杂因素影响后,EMP升高仍是影响CMB发病的危险因素.结论血浆EMP升高是影响CMB发病的独立危险因素,EMP检测可作为临床预测脑梗死患者是否合并CMB的指标.

  17. Analysis on the correlation of cerebral microbleeds and post-stroke depression in lacunar stroke%脑微出血与腔隙性脑梗死患者卒中后抑郁的相关性分析

    Institute of Scientific and Technical Information of China (English)

    牛晓波; 缑元冲; 郭旭亮

    2015-01-01

    目的 探讨脑微出血(CMB)与腔隙性脑梗死(LI)患者卒中后抑郁的相关性.方法 选择腔隙性脑梗死患者216例,进行老年抑郁量表(GDS)评测,≥5分为存在抑郁,分为抑郁组和无抑郁组.记录两组CMB总数量及脑叶CMB、深部CMB、幕下CMB及左右半球CMB数量,分析两组CMB数量与部位、人口学资料、临床资料及影像学资料的关系.结果 两组在脑叶CMB及左半球CMB、女性、美国国立卫生研究院卒中量表(NIHSS)评分、脑白质病变(WML)、深部LI及左半球LI等方面比较差异有统计学意义(P<0.05).多因素分析提示脑叶CMB是卒中后抑郁(PSD)的独立危险因素(OR=5.843,P=0.040).结论 脑叶CMB及左半球CMB为PSD危险因素,其他危险因素包括女性、较严重的神经功能缺损、脑白质病变、LI特别是深部及左半球LI.

  18. Initial Study

    DEFF Research Database (Denmark)

    Torp, Kristian

    2009-01-01

    Congestion is a major problem in most cities and the problem is growing (Quiroga, 2000) (Faghri & Hamad, 2002). When the congestion level is increased the drivers notice this as delays in the traffic (Taylor, Woolley, & Zito, 2000), i.e., the travel time for the individual driver is simply...... increased. In the initial study presented here, the time it takes to pass an intersection is studied in details. Two major signal-controlled four-way intersections in the center of the city Aalborg are studied in details to estimate the congestion levels in these intersections, based on the time it takes...

  19. Floodplain Study

    Data.gov (United States)

    Montgomery County of Maryland — The purpose of a floodplain study is to establish the 100-year floodplain limits within or near a development in order to preserve the natural resources within the...

  20. Actuarial Studies

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Office of the Actuary in the Centers for Medicare and Medicaid Services (CMS) from time to time conducts studies on various aspects of the Medicare and Medicaid...

  1. Studying Sideways

    DEFF Research Database (Denmark)

    Plesner, Ursula

    2011-01-01

    One strand of the qualitative interview literature has been concerned with the normative or otherwise problematic implications of studying down or studying up (i.e., interviewing “disadvantaged” people or elites). This interview literature is part of a tradition of taking up the problem of power ......, we must cultivate interview methods which cause confrontation and disagreement—not to acknowledge asymmetry but to enhance the quality of research....

  2. Study of nanosensor systems for hypertension associated cerebrovascular and cardiovascular disorders

    Science.gov (United States)

    Ramasamy, Mouli; Varadan, Vijay K.

    2015-04-01

    Hypertension and hypertension associated cerebrovascular and cardiovascular diseases are on a rise. At-least 970 million people in the world and Seventy percent of the American adults are affected by high blood pressure, also known as hypertension. Even though blood pressure monitoring systems are readily available, the number of people being affected has been increasing. Most of the blood pressure monitoring systems require cumbersome approaches. Even the noninvasive techniques have not lowered the number of people affected nor did at-least increase the user base of these systems. Uncontrolled or untreated hypertension may lead to various cerebrovascular disorders including stroke, hypertensive crisis, lacunar infarcts intracerebral damage, microaneurysm, and cardiovascular disorders including heart failure, myocardial infraction, and ischemic heart disease. Hypertension is rated as the one of the most important causes of premature death in spite of the technical advances in biomedical technology. This paper briefs a review of the widely adopted blood pressure monitoring methods, research techniques, and finally, proposes a concept of implementing nanosensors and wireless communication for real time non-invasive blood pressure monitoring.

  3. Study Strategies

    DEFF Research Database (Denmark)

    Nielsen, Camilla Kirketerp; Noer, Vibeke Røn

    ID: 1277 / 22 SES 06 B: 2 22. Research in Higher Education Format of Presentation: Paper Alternative EERA Network: 19. Ethnography Topics: NW 22: Teaching, learning and assessment in higher education Keywords: Profession-oriented learning, study strategies, professionalisation processes...... and the close-up analysis of different learning situations in different contexts aim to expand empirical knowledge on the actual teaching practices and student´s learning processes and to provide important perspectives on student´s study-strategies and their possible consequences in relation to both `life...... module”. The projects differ in terms of both starting point and main focus of research (an alternative educational model and profession-orientated Game-based learning). However, in the on-going process of research, an empirical ´harmony´ on common recurrent themes related to students `study strategies...

  4. Writing Study and Grammar Study

    Institute of Scientific and Technical Information of China (English)

    马青

    2013-01-01

    This study is undertaken to describe,classify and analyze the problems in Chinese college students’ writing of CET-4 through contrastive analysis,statistical analysis and error analysis.The main problems appearing in CET-4 writing are the wrong usage of words,sentence structures and the lack of coherence.Meanwhile it proves grammar study plays an important and basic role in CET-4 writing.

  5. Studying CO

    NARCIS (Netherlands)

    Boullenger, B.; Verdel, A.; Paap, B.; Thorbecke, J.; Draganov, D.

    2014-01-01

    Seismic interferometry applied to ambient-noise measurements allows the retrieval of the seismic response between pairs of receivers. We studied ambient-noise seismic interferometry (ANSI) to retrieve time-lapse reflection responses from a reservoir during CO2 geologic sequestration, usin

  6. [Efficacy of Ingavirin in the combined treatment of ARVI complicated by tonsillitis].

    Science.gov (United States)

    2011-01-01

    This paper was designed to report the results of an open randomized comparative study of therapeutic efficacy of Ingavirin used for the treatment of adult patients with acute respiratory viral infections (ARVI) complicated by lacunar tonsillitis. The study has demonstrated that the combined application of an antibacterial agent and Ingavirin showing antiviral and anti-inflammatory properties produces a significantly more pronounced therapeutic effect compared with the standard treatment of the disease in question. This finding gives reason to recommend Ingavirin for the wide clinical application as an agent for combined therapy of acute respiratory viral infections.

  7. Study protocol

    DEFF Research Database (Denmark)

    Thorsteinsson, Troels; Helms, Anne Sofie; Adamsen, Lis

    2013-01-01

    (n = 120). RESPECT includes Danish-speaking children diagnosed with cancer and treated at pediatric oncology units in Denmark. Primary endpoints are the level of educational achievement one year after the cessation of first-line cancer therapy, and the value of VO2max one year after the cessation......Background During cancer treatment children have reduced contact with their social network of friends, and have limited participation in education, sports, and leisure activities. During and following cancer treatment, children describe school related problems, reduced physical fitness......, and problems related to interaction with peers. Methods/design The RESPECT study is a nationwide population-based prospective, controlled, mixed-methods intervention study looking at children aged 6-18 years newly diagnosed with cancer in eastern Denmark (n = 120) and a matched control group in western Denmark...

  8. Study protocol

    DEFF Research Database (Denmark)

    Thorsteinsson, Troels; Helms, Anne Sofie; Adamsen, Lis;

    2013-01-01

    in the intervention program. The physical and social intervention examines the effect of early, structured, individualized, and continuous physical activity from diagnosis throughout the treatment period. The patients are tested at diagnosis, at 3 and 6 months after diagnosis, and one year after the cessation...... to interaction with peers.Methods/design: The RESPECT study is a nationwide population-based prospective, controlled, mixed-methods intervention study looking at children aged 6-18 years newly diagnosed with cancer in eastern Denmark (n = 120) and a matched control group in western Denmark (n = 120). RESPECT....... Secondary endpoints are quality of life measured by validated questionnaires and interviews, and physical performance. RESPECT includes a multimodal intervention program, including ambassador-facilitated educational, physical, and social interventions. The educational intervention includes an educational...

  9. Invisibility Studies

    DEFF Research Database (Denmark)

    Invisibility Studies explores current changes in the relationship between what we consider visible and what invisible in different areas of contemporary culture. Contributions trace how these changes make their marks on various cultural fields and investigate the cultural significance of these de...... this conversation by bringing together scholars across the fields of architectural history and theory, art, film and literature, philosophy, cultural theory and contemporary anthropology as well as featuring work by a collective of artists.......Invisibility Studies explores current changes in the relationship between what we consider visible and what invisible in different areas of contemporary culture. Contributions trace how these changes make their marks on various cultural fields and investigate the cultural significance...

  10. Clinical symptoms and risk factors in cerebral microangiopathy patients.

    Directory of Open Access Journals (Sweden)

    Sandra Okroglic

    Full Text Available OBJECTIVE: Although the clinical manifestation and risk factors of cerebral microangiopathy (CM remain unclear, the number of diagnoses is increasing. Hence, patterns of association among lesion topography and severity, clinical symptoms and demographic and disease risk factors were investigated retrospectively in a cohort of CM patients. METHODS: Patients treated at the Department of Neurology, University of Bonn for CM (n = 223; 98m, 125f; aged 77.32±9.09 from 2005 to 2010 were retrospectively enrolled. Clinical symptoms, blood chemistry, potential risk factors, demographic data and ratings of vascular pathology in the brain based on the Wahlund scale were analyzed using Pearson's chi square test and one-way ANOVA. RESULTS: Progressive cognitive decline (38.1%, gait apraxia (27.8%, stroke-related symptoms and seizures (24.2%, TIA-symptoms (22% and vertigo (17% were frequent symptoms within the study population. Frontal lobe WMLs/lacunar infarcts led to more frequent presentation of progressive cognitive decline, seizures, gait apraxia, stroke-related symptoms, TIA, vertigo and incontinence. Parietooccipital WMLs/lacunar infarcts were related to higher frequencies of TIA, seizures and incontinence. Basal ganglia WMLs/lacunar infarcts were seen in patients with more complaints of gait apraxia, vertigo and incontinence. Age (p = .012, arterial hypertension (p<.000, obesity (p<.000 and cerebral macroangiopathy (p = .018 were positively related to cerebral lesion load. For increased glucose level, homocysteine, CRP and D-Dimers there was no association. CONCLUSION: This underlines the association of CM with neurological symptoms upon admission in a topographical manner. Seizures and vertigo are symptoms of CM which may have been missed in previous studies. In addition to confirming known risk factors such as aging and arterial hypertension, obesity appears to increase the risk as well. Since the incidence of CM is increasing, future

  11. Security Studies

    OpenAIRE

    ,

    2005-01-01

    Security Studies has firmly established itself as a leading journal on international security issues. The journal publishes theoretical, historical and policy-oriented articles on the causes and consequences of war, and the sources and conditions of peace. The journal has published articles on balancing vs. bandwagoning, deterrence in enduring rivalries, the Domino theory, nuclear weapons proliferation, civil-military relations, political reforms in China, strategic culture in Asia and the P...

  12. A study

    Directory of Open Access Journals (Sweden)

    V.M. Abbasov

    2013-12-01

    Full Text Available The influence of the concentration of novel surfactants based on corn oil on the corrosion behavior of carbon steel in CO2 saturated solution at different temperatures was studied. The investigation involved weight loss, LPR corrosion rate and extrapolation of cathodic and anodic Tafel lines method. Results obtained show that the surfactants studied are efficient corrosion inhibitors for carbon steel in CO2 saturated brine. The inhibition efficiency (IE% increases with an increase in the concentration of the studied surfactant. The inhibition process was attributed to the formation of the adsorbed film on the metal surface that protects the surface against the corrosive agent. The data exhibited that the inhibition efficiency slightly increases with increasing temperature. The surface activity of the synthesized surfactant solutions was determined using surface tension measurements at 25 °C. Adsorption of inhibitors was found to obey the Langmuir isotherm. The standard enthalpy, ΔHads.°, entropy, ΔSads.° and free energy changes of adsorption were evaluated; the calculated values of ΔHads.° and ΔGads° were negative while those for ΔSads.° were positive. Mainly, all the above results are suggestive of chemisorption of the surfactant molecules on the metal surface. Scanning electron microscopy (SEM and Energy dispersive X-ray fluorescence (EDRF observations of the electrode surface confirmed the existence of such an adsorbed film.

  13. Study protocol

    DEFF Research Database (Denmark)

    Madsen, Helle Østergaard; Dam, Ole Henrik; Hageman, Ida

    2012-01-01

    and demographically matched control respondents will be contacted in a similar manner the subsequent winter season. The Seasonal Pattern Assessment Questionnaire rates seasonal variation within the six items: sleep, appetite, social activity, mood, energy and body weight. The Seasonal Pattern Assessment Questionnaire......INTRODUCTION: People with seasonal affective disorder (SAD) experience recurrent seasonal fluctuations in energy, mood and appetite. Retinal light exposure is suggested to play an important role in the pathogenesis and treatment of SAD. The aim of the study is to determine the prevalence of SAD...

  14. Effect of Repetition Rate on Femtosecond Laser-Induced Homogenous Microstructures

    Directory of Open Access Journals (Sweden)

    Sanchari Biswas

    2016-12-01

    Full Text Available We report on the effect of repetition rate on the formation and surface texture of the laser induced homogenous microstructures. Different microstructures were micromachined on copper (Cu and titanium (Ti using femtosecond pulses at 1 and 10 kHz. We studied the effect of the repetition rate on structure formation by comparing the threshold accumulated pulse ( F Σ p u l s e values and the effect on the surface texture through lacunarity analysis. Machining both metals at low F Σ p u l s e resulted in microstructures with higher lacunarity at 10 kHz compared to 1 kHz. On increasing F Σ p u l s e , the microstructures showed higher lacunarity at 1 kHz. The effect of the repetition rate on the threshold F Σ p u l s e values were, however, considerably different on the two metals. With an increase in repetition rate, we observed a decrease in the threshold F Σ p u l s e on Cu, while on Ti we observed an increase. These differences were successfully allied to the respective material characteristics and the resulting melt dynamics. While machining Ti at 10 kHz, the melt layer induced by one laser pulse persists until the next pulse arrives, acting as a dielectric for the subsequent pulse, thereby increasing F Σ p u l s e . However, on Cu, the melt layer quickly resolidifies and no such dielectric like phase is observed. Our study contributes to the current knowledge on the effect of the repetition rate as an irradiation parameter.

  15. Regulation of valve endothelial cell vasculogenic network architectures with ROCK and Rac inhibitors.

    Science.gov (United States)

    Arevalos, C Alexander; Walborn, Amanda T; Rupert, Amanda A; Berg, Jonathan M; Godfrey, Elizabeth L; Nguyen, Jacqueline M V; Grande-Allen, K Jane

    2015-03-01

    The age- and disease-dependent presence of microvessels within heart valves is an understudied characteristic of these tissues. Neovascularization involves endothelial cell (EC) migration and cytoskeletal reorientation, which are heavily regulated by the Rho family of GTPases. Given that valve ECs demonstrate unique mesenchymal transdifferentiation and cytoskeletal mechanoresponsiveness, compared to vascular ECs, this study quantified the effect of inhibiting two members of the Rho family on vasculogenic network formation by valve ECs. A tubule-like structure vasculogenesis assay (assessing lacunarity, junction density, and vessel density) was performed with porcine aortic valve ECs treated with small molecule inhibitors of Rho-associated serine-threonine protein kinase (ROCK), Y-27632, or the Rac1 inhibitor, NSC-23766. Actin coordination, cell number, and cell migration were assessed through immunocytochemistry, MTT assay, and scratch wound healing assay. ROCK inhibition reduced network lacunarity and interrupted proper cell-cell adhesion and actin coordination. Rac1 inhibition increased lacunarity and delayed actin-mediated network formation. ROCK inhibition alone significantly inhibited migration, whereas both ROCK and Rac1 inhibition significantly reduced cell number over time compared to controls. Compared to a vascular EC line, the valve ECs generated a network with larger total vessel length, but a less smooth appearance. Both ROCK and Rac1 inhibition interfered with key processes in vascular network formation by valve ECs. This is the first report of manipulation of valve EC vasculogenic organization in response to small molecule inhibitors. Further study is warranted to comprehend this facet of valvular cell biology and pathology and how it differs from vascular biology. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Effect of Repetition Rate on Femtosecond Laser-Induced Homogenous Microstructures.

    Science.gov (United States)

    Biswas, Sanchari; Karthikeyan, Adya; Kietzig, Anne-Marie

    2016-12-19

    We report on the effect of repetition rate on the formation and surface texture of the laser induced homogenous microstructures. Different microstructures were micromachined on copper (Cu) and titanium (Ti) using femtosecond pulses at 1 and 10 kHz. We studied the effect of the repetition rate on structure formation by comparing the threshold accumulated pulse ( F Σ p u l s e ) values and the effect on the surface texture through lacunarity analysis. Machining both metals at low F Σ p u l s e resulted in microstructures with higher lacunarity at 10 kHz compared to 1 kHz. On increasing F Σ p u l s e , the microstructures showed higher lacunarity at 1 kHz. The effect of the repetition rate on the threshold F Σ p u l s e values were, however, considerably different on the two metals. With an increase in repetition rate, we observed a decrease in the threshold F Σ p u l s e on Cu, while on Ti we observed an increase. These differences were successfully allied to the respective material characteristics and the resulting melt dynamics. While machining Ti at 10 kHz, the melt layer induced by one laser pulse persists until the next pulse arrives, acting as a dielectric for the subsequent pulse, thereby increasing F Σ p u l s e . However, on Cu, the melt layer quickly resolidifies and no such dielectric like phase is observed. Our study contributes to the current knowledge on the effect of the repetition rate as an irradiation parameter.

  17. Nonlinear analysis of drainage systems to examine surface deformation: an example from Potwar Plateau (Northern Pakistan)

    Science.gov (United States)

    Shahzad, F.; Mahmood, S. A.; Gloaguen, R.

    2010-03-01

    We devise a procedure in order to characterize the relative vulnerability of the Earth's surface to tectonic deformation using the geometrical characteristics of drainage systems. The present study focuses on the nonlinear analysis of drainage networks extracted from Digital Elevation Models in order to localize areas strongly influenced by tectonics. We test this approach on the Potwar Plateau in northern Pakistan. This area is regularly affected by damaging earthquakes. Conventional studies cannot pinpoint the zones at risk, as the whole region is characterized by a sparse and diffuse seismicity. Our approach is based on the fact that rivers tend to linearize under tectonic forcing. Thus, the low fractal dimensions of the Swan, Indus and Jehlum Rivers are attributed to neotectonic activity. A detailed textural analysis is carried out to investigate the linearization, heterogeneity and connectivity of the drainage patterns. These textural aspects are quantified using the fractal dimension, as well as lacunarity and succolarity analysis. These three methods are complimentary in nature, i.e. objects with similar fractal dimensions can be distinguished further with lacunarity and/or succolarity analysis. We generate maps of fractal dimensions, lacunarity and succolarity values using a sliding window of 2.5 arc minutes by 2.5 arc minutes (2.5'×2.5'). These maps are then interpreted in terms of land surface vulnerability to tectonics. This approach allowed us to localize several zones where the drainage system is highly structurally controlled on the Potwar Plateau. The region located between Muree and Muzaffarabad is found to be prone to destructive events whereas the area westward from the Indus seems relatively unaffected. We conclude that a nonlinear analysis of the drainage system is an efficient additional tool to locate areas likely to be affected by massive destructing events affecting the Earth's surface and therefore threaten human activities.

  18. Nonlinear analysis of drainage systems to examine surface deformation: an example from Potwar Plateau (Northern Pakistan

    Directory of Open Access Journals (Sweden)

    F. Shahzad

    2010-03-01

    Full Text Available We devise a procedure in order to characterize the relative vulnerability of the Earth's surface to tectonic deformation using the geometrical characteristics of drainage systems. The present study focuses on the nonlinear analysis of drainage networks extracted from Digital Elevation Models in order to localize areas strongly influenced by tectonics. We test this approach on the Potwar Plateau in northern Pakistan. This area is regularly affected by damaging earthquakes. Conventional studies cannot pinpoint the zones at risk, as the whole region is characterized by a sparse and diffuse seismicity. Our approach is based on the fact that rivers tend to linearize under tectonic forcing. Thus, the low fractal dimensions of the Swan, Indus and Jehlum Rivers are attributed to neotectonic activity. A detailed textural analysis is carried out to investigate the linearization, heterogeneity and connectivity of the drainage patterns. These textural aspects are quantified using the fractal dimension, as well as lacunarity and succolarity analysis. These three methods are complimentary in nature, i.e. objects with similar fractal dimensions can be distinguished further with lacunarity and/or succolarity analysis. We generate maps of fractal dimensions, lacunarity and succolarity values using a sliding window of 2.5 arc minutes by 2.5 arc minutes (2.5'×2.5'. These maps are then interpreted in terms of land surface vulnerability to tectonics. This approach allowed us to localize several zones where the drainage system is highly structurally controlled on the Potwar Plateau. The region located between Muree and Muzaffarabad is found to be prone to destructive events whereas the area westward from the Indus seems relatively unaffected. We conclude that a nonlinear analysis of the drainage system is an efficient additional tool to locate areas likely to be affected by massive destructing events affecting the Earth's surface and therefore threaten human

  19. Complementary Study

    Science.gov (United States)

    Yamada, H.

    2009-02-01

    In this lecture, it is emphasized that sufficient resolution of scientific issues for a fusion energy reactor can be given by complementary studies. Key scientific issues for a fusion energy reactor and ITER addressed by a complementary study in the Large Helical Device (LHD) are discussed. It should be noted that ITER is definitely a necessary condition but not a sufficient condition. Helical systems including stellarators and heliotrons are defined as alternative concepts. These approaches also aim at a fusion energy reactor based on their own concept and simultaneously benefit progress in tokamaks, more specifically ITER itself. The exact science to manage a 3-D geometry has been being developed in helical systems. A physical model with much accuracy and breadth will demonstrate its applicability to ITER. Topics to validate "complementary" approaches such as 3-D equilibrium, interchange MHD mode, control of radial electric field & structure formation, dynamics of a magnetic island, density limit and edge plasmas are discussed. Complementary is not Supplementary. ITER is complementary to development of a helical fusion energy reactor as well. Complementary approaches transcend existing disciplinary horizons and enable big challenges.

  20. Signature of fractionally charged projectile fragments in /sup 24/Mg-emulsion interaction

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, D.; Roy, J.; Mukherjee, A.; Ghosh, A.

    1987-07-01

    From the measurement of charge of the projectile fragments produced in /sup 24/Mg-emulsion nuclei at 4.5 (GeV/c)/N, an indication of the existence of charges Z = 8/3 and 5/3 among the projectile fragments was obtained. The measurement was based on the lacunarity study of the linear structure of the ionizing track, and the percentage abundance of Z = 8/3 and 5/3 has found to be consistent with the relative abundance of anomalons.

  1. A comparison of multifractal behavior in galaxy samples from SDSS

    Science.gov (United States)

    García-Farieta, J. E.; Casas-Miranda, R. A.

    2017-07-01

    We studied the spatial distribution of galaxies with samples from the Sloan Digital Sky Survey (SDSS) including observational holes in the masks. From a multifractal formalism and using the sliding window technique for each sample, we have determined the fractal dimension and the lacunarity spectrum. Aditionally, the scale of homogeneity was determined for each struture parameter. Our results show that the galaxy clustering exhibits a behavior that depends on the radial distance, revealing that the hierarchical distribution is not a fractal at large-scales, with a transition to homogeneity on large scales below 130 Mpc/h.

  2. Subtypes of ischemic cerebral circulation disorders at young age: diagnosis and treatment

    Directory of Open Access Journals (Sweden)

    Natalia Vyacheslavovna Pizova

    2012-01-01

    Full Text Available The paper shows that it is urgent to study stroke in young patients aged 15—45 years. In accordance with the TOAST classification, the author presents the major pathogenetic subtypes of ischemic stroke (IS: atherothromboembolic, cardioembolic, lacunar, that of other known and unknown etiology. The clinical picture and diagnostic principles of IS at young age are considered. Particular emphasis is laid on therapy for IS. It is pointed out that the leading therapy option in these patients is thrombolysis; intravenous recombinant tissue plasminogen activator is more frequently used; oral anticoagulants and antiplatelet agents are certain to prescribe.

  3. Conceptual study

    Energy Technology Data Exchange (ETDEWEB)

    Harty, H.

    1978-09-01

    This appendix is a compendium of topical reports prepared for the Hanford Nuclear Energy Center: Status Report: Conceptual Fuel Cycle Studies for the Hanford Nuclear Energy Center; Selection of Heat Disposal Methods for a Hanford Nuclear Energy Center; Station Service Power Supply for a Hanford Nuclear Energy Center (HNEC); Impact of a Hanford Nuclear Energy Center on Ground Level Fog and Humidity; A Review of Potential Technology for the Seismic Characterization of Nuclear Energy Centers; Reliability of Generation at a Hanford Nuclear Energy Center (HNEC); Meteorological Evaluation of Multiple Reactor Contamination Probabilities for a Hanford Nuclear Energy Center; Electric Power Transmission for a Hanford Nuclear Energy Center (HNEC); The Impact of a Hanford Nuclear Energy Center on Cloudiness and Insolation; and A Licensing Review for an HNEC.

  4. Clinical Studies

    DEFF Research Database (Denmark)

    Pallesen, Ulla

    and repair? Have new materials improved longevity? Are there still clinical and material problems to be solved? And what has the highest impact on longevity of posterior resin restorations – the material, the dentist, the patient or the tooth? These matters will be discussed on the basis of the literature......Within the last 25 years composite resin materials have in many countries successively replaced amalgam as a restorative for posterior teeth. Resin materials and bonding systems are continuously being improved by the manufactures, adhesive procedures are now included in the curriculum of most...... universities and practicing dentists restore millions of teeth throughout the World with composite resin materials. Do we know enough about the clinical performance of these restorations over time? Numerous in vitro studies are being published on resin materials and adhesion, some of them attempting to imitate...

  5. Nutritional studies

    Science.gov (United States)

    Rambaut, P. C.; Smith, M. C., Jr.; Wheeler, H. O.

    1975-01-01

    Detailed metabolic studies were conducted of the Apollo 16 and Apollo 17 flight crews, and the results are presented in tabular form. Intake and absorption data are also included. Apollo nutrient intakes were found to be characteristically hypocaloric. Estimates of body composition changes from metabolic balance data, from preflight and postflight weights and volumes, and from total body water and potassium provide no evidence for diminished caloric requirements during a flight. As observed during the Gemini Program and during periods of bed rest, measurements of bone density and metabolic balance confirm a tendency toward loss of skeletal tissue in weightlessness. No evidence exists that any inflight metabolic anomaly, including hypokalemia, was induced by marginal or deficient nutrient intakes. In general, the Apollo crewmen were well nourished and exhibited normal gastroenterological functions, although appetite was somewhat diminished and the organoleptic response to food was somewhat modified during flight.

  6. SOCIOLOGICAL STUDIES

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    PAPER Post-Sociology: Exploration and Reflection Xie Lizhong Abstract: "Post-Sociology" refers to a new perspective which is different from tradi- tional perspectives of social studies. "Post-Social History" and "Pluralistic Discourse Analysis" could be seen as its two specific examples. "Discourse Constructivism" and "Pluralism" are the two core concepts of "Post-Sociology". That encouraging people to realize that all "social reality" including our experiences, thoughts and speech are just a "discoursive reality" constructed by social actors under the guidance and constraints of certain discourse system, is the major significance of "PostSociology". Some critics on "Post-Sociology" are misunderstandings, while others couldn't stand to strict analysis.

  7. Systems Studies

    Energy Technology Data Exchange (ETDEWEB)

    Graham, R.L.

    1998-03-17

    The Systems Studies Activity had two objectives: (1) to investigate nontechnical barriers to the deployment of biomass production and supply systems and (2) to enhance and extend existing systems models of bioenergy supply and use. For the first objective, the Activity focused on existing bioenergy markets. Four projects were undertaken: a comparative analysis of bioenergy in Sweden and Austria; a one-day workshop on nontechnical barriers jointly supported by the Production Systems Activity; the development and testing of a framework for analyzing barriers and drivers to bioenergy markets; and surveys of wood pellet users in Sweden, Austria and the US. For the second objective, two projects were undertaken. First, the Activity worked with the Integrated BioEnergy Systems (TBS) Activity of TEA Bioenergy Task XIII to enhance the BioEnergy Assessment Model (BEAM). This model is documented in the final report of the IBS Activity. The Systems Studies Activity contributed to enhancing the feedstock portion of the model by developing a coherent set of willow, poplar, and switchgrass production modules relevant to both the US and the UK. The Activity also developed a pretreatment module for switchgrass. Second, the Activity sponsored a three-day workshop on modeling bioenergy systems with the objectives of providing an overview of the types of models used to evaluate bioenergy and promoting communication among bioenergy modelers. There were nine guest speakers addressing different types of models used to evaluate different aspects of bioenergy, ranging from technoeconomic models based on the ASPEN software to linear programming models to develop feedstock supply curves for the US. The papers from this workshop have been submitted to Biomass and Bioenergy and are under editorial review.

  8. On the fractal morphology of combustion-generated soot aggregates

    Energy Technology Data Exchange (ETDEWEB)

    Koylu, U.O. [Yale Univ., New Haven, CT (United States)

    1995-12-31

    The fractal properties of soot aggregates were investigated using ex-situ and in-situ experimental methods as well as computer simulations. Ex-situ experiments involved thermophoretic sampling and analysis by transmission electron microscopy (TEM), while in-situ measurements employed angular static light scattering and data inversion based on Rayleigh-Debye-Gans (RDG) approximation. Computer simulations used a sequential algorithm which mimics mass fractal-like structures. So from a variety of hydrocarbon-fueled laminar and turbulent nonpremixed flame environments were considered in the present study. The TEM analysis of projected soot images sampled from fuel-rich conditions of buoyant and weakly-buoyant laminar flames indicated that the fractal dimension of soot was relatively independent of position in flames, fuel type and flame condition. These measurements yielded an average fractal dimension of 1.8, although other structure parameters such as the primary particle diameters and number of primary particles in aggregates had wide range of values. Fractal prefactor (lacunarity) was also measured for soot sampled from the fuel-lean conditions of turbulent flames, considering the actual morphology by tilting the samples during TEM analysis. These measurements yielded a fractal dimension of 1.65 and a lacunarity of 8.5, with experimental uncertainties (95% confidence) of 0.08 and 0.5, respectively. Relationships between the actual and projected structure properties of soot were also developed by combining TEM observations with numerical simulations. Practical approximate formulae were suggested to find radius of gyration of an aggregate from its maximum dimension, and number of primary particles in an aggregate from projected area. Finally, the fractal dimension and lacunarity of soot were obtained using light scattering for the same conditions of the above TEM measurements.

  9. Fractal analysis of the structural complexity of the connective tissue in human carotid bodies

    Directory of Open Access Journals (Sweden)

    Diego eGuidolin

    2014-11-01

    Full Text Available The carotid body may undergo different structural changes during perinatal development, aging, or in response to environmental stimuli. In the previous literature, morphometric approaches to evaluate these changes have considered quantitative first order parameters, such as volumes or densities, while changes in spatial disposition and/or complexity of structural components have not yet been considered. In the present study, different strategies for addressing morphological complexity of carotid body, apart from the overall amount of each tissue component, were evaluated and compared. In particular, we considered the spatial distribution of connective tissue in the carotid bodies of young control subjects, young opiate-related deaths and aged subjects, through analysis of dispersion (Morisita’s index, gray level co-occurrence matrix (entropy, angular second moment, variance, correlation, and fractal analysis (fractal dimension, lacunarity. Opiate-related deaths and aged subjects showed a comparable increase in connective tissue with respect to young controls. However, the Morisita’s index (p<0.05, angular second moment (p<0.05, fractal dimension (p<0.01 and lacunarity (p<0.01 permitted to identify significant differences in the disposition of the connective tissue between these two series. A receiver operating characteristic (ROC curve was also calculated to evaluate the efficiency of each parameter. The fractal dimension and lacunarity, with areas under the ROC curve of 0.9651 (excellent accuracy and 0.8835 (good accuracy, respectively, showed the highest discriminatory power. They evidenced higher level of structural complexity in the carotid bodies of opiate-related deaths than old controls, due to more complex branching of intralobular connective tissue. Further analyses will have to consider the suitability of these approaches to address other morphological features of the carotid body, such as different cell populations

  10. Relation between cardiovascular disease risk markers and brain infarcts detected by magnetic resonance imaging in an elderly population.

    Science.gov (United States)

    Nylander, Ruta; Lind, Lars; Wikström, Johan; Lindahl, Bertil; Venge, Per; Larsson, Anders; Ärnlöv, Johan; Berglund, Lars; Ahlström, Håkan; Johansson, Lars; Larsson, Elna-Marie

    2015-02-01

    Established cardiovascular risk markers, such as hypertension, are associated with increased risk of brain infarcts. The newer markers N-terminal pro-brain natriuretic peptide, troponin I, C-reactive protein, and cystatin C may affect the risk of cardiovascular events and potentially, thereby, also stroke. We investigated the association between established and new risk markers for cardiovascular disease and brain infarcts detected by magnetic resonance imaging (MRI) at age 75. Four hundred six randomly selected subjects from the Prospective Investigation of the Vasculature in Uppsala Seniors study were examined with MRI of the brain at age 75. Blood samples, measurements, and dedicated questionnaires at age 70 were used for analysis of risk markers. A history of diseases had been obtained at age 70 and 75. MRI was evaluated regarding lacunar and cortical infarcts. Univariate associations between outcomes and risk markers were assessed with logistic regression models. One or more infarcts were seen in 23% of the subjects (20% had only lacunar infarcts, 1% had only cortical infarcts, and 2% had both). Hypertension (odds ratio [OR] 2.6, 95% confidence interval [CI] 1.4, 4.7) and obesity (OR 1.3; CI 1.0, 1.8) were significantly associated with increased risk of brain infarction. The newer risk markers were not significantly associated with the brain infarcts. The new markers were not associated with the predominantly lacunar infarcts in our 75-year-old population, why troponin I and NT-proBNP may be associated mainly with cardioembolic infarcts as shown recently. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  11. Study on

    Directory of Open Access Journals (Sweden)

    Razieh Pourdarbani

    2015-01-01

    Full Text Available In the present study, a machine vision based, online sorting system was developed, the aim being to sort Date fruits (Berhee CV. based at different stages of maturity, namely Khalal, Rotab and Tamar to meet consumers’ demands. The system comprises a conveying unit, illumination and capturing unit, and sorting unit. Physical and mechanical features were extracted from the samples provided, and the detection algorithm was designed accordingly. An index based on color features was defined to detect Date samples. Date fruits were fed on a conveyor belt in a row. When they were at the center of the camera’s field of view, a snapshot was taken, the image was processed immediately and the maturity stage of the Date was determined. When the Date passed the sensor, positioned at the end of the conveyor belt, a signal was sent to the interface circuit and an appropriate actuator, driven by a step motor, was actuated, leading the Date toward an appropriate port. For validation of proposed system performance, entire samples were again sorted by experts visually. Detection rate of the system for Tamar and Khalal was satisfactory. Although the detection rate was insufficient for the Rotab stage, there was no a significant difference between system accuracy and that obtained by the experts. The speed of image processing system was 0.34 s. System capacity was 15.45 kg/h.

  12. Scale-dependent Patterns in One-dimensional Fracture Spacing and Aperture Data

    Science.gov (United States)

    Roy, A.; Perfect, E.

    2013-12-01

    One-dimensional scanline data about fracture spacing and size attributes such as aperture or length are mostly considered in separate studies that compute the cumulative frequency of these attributes without regard to their actual spatial sequence. In a previous study, we showed that spacing data can be analyzed using lacunarity to identify whether fractures occur in clusters. However, to determine if such clusters also contain the largest fractures in terms of a size attribute such as aperture, it is imperative that data about the size attribute be integrated with information about fracture spacing. While for example, some researchers have considered aperture in conjunction with spacing, their analyses were either applicable only to a specific type of data (e.g. multifractal) or failed to characterize the data at different scales. Lacunarity is a technique for analyzing multi-scale non-binary data and is ideally-suited for characterizing scanline data with spacing and aperture values. We present a technique that can statistically delineate the relationship between size attributes and spatial clustering. We begin by building a model scanline that has complete partitioning of fractures with small and large apertures between the intercluster regions and clusters. We demonstrate that the ratio of lacunarity for this model to that of its counterpart for a completely randomized sequence of apertures can be used to determine whether large-aperture fractures preferentially occur next to each other. The technique is then applied to two natural fracture scanline datasets, one with most of the large apertures occurring in fracture clusters, and the other with more randomly-spaced fractures, without any specific ordering of aperture values. The lacunarity ratio clearly discriminates between these two datasets and, in the case of the first example, it is also able to identify the range of scales over which the widest fractures are clustered. The technique thus developed for

  13. Cerebral Microbleeds Are Associated with Worse Cognitive Function in the Nondemented Elderly with Small Vessel Disease

    Directory of Open Access Journals (Sweden)

    Kazuo Yamashiro

    2014-12-01

    Full Text Available Background: Cerebral small vessel disease (SVD is a leading cause of cognitive decline in the elderly. Cerebral microbleeds (CMBs have emerged as an important manifestation of cerebral SVD, in addition to lacunar infarcts and white matter lesions (WMLs. We investigated whether the presence and location of CMBs in elderly subjects were associated with cognitive function, independent of lacunar infarcts and WMLs. Methods: One hundred and forty-eight nondemented elderly with SVD, defined as the presence of lacunar infarcts and/or WMLs on magnetic resonance imaging (MRI, were studied. Executive function and global cognition were assessed by the Frontal Assessment Battery (FAB and Mini-Mental State Examination (MMSE, respectively. The differences in the scores for the FAB and MMSE between CMB-positive and CMB-negative subjects were calculated after adjusting for possible confounders. Results: The mean age of the subjects was 72.4 w 8.6 years. CMBs were detected in 48 subjects (32%, with a mean number of CMBs per subject of 1.6 (range 0-31. Among CMB-positive subjects, 42 (87.5% had CMBs in deep or infratentorial regions with or without lobar CMBs, and 6 (12.5% had CMBs in strictly lobar regions. The presence of CMBs was significantly associated with FAB and MMSE scores after adjustment for age, years of education, brain volume and the presence of lacunar infarcts (for the FAB or severe WMLs (for the MMSE. The presence of CMBs in the basal ganglia, in the thalamus or in the lobar regions was associated with FAB scores, while that in the lobar regions was associated with MMSE scores. However, there was no association between CMBs in the infratentorial regions and cognitive parameters. Conclusions: In nondemented elderly with SVD on MRI, the presence of CMBs was independently associated with worse executive and global cognitive functions. CMBs seemed to reflect hypertensive microangiopathy in this population, and CMBs in specific areas may play an

  14. Vascular organization of the hystricomorph placenta: a comparative study in the agouti, capybara, guinea pig, paca and rock cavy.

    Science.gov (United States)

    Miglino, M A; Carter, A M; Ambrosio, C E; Bonatelli, M; De Oliveira, M F; Dos Santos Ferraz, R H; Rodrigues, R F; Santos, T C

    2004-05-01

    The placental vasculature of five hystricomorph rodents was examined by latex injection of the blood vessels, immunohistochemistry and scanning electron microscopy of vessel casts. The pattern of branching of the vessels is described at the level of fine structure. The placenta is divided into lobes separated by interlobular trophoblast. Fetal arteries course through the interlobular areas and give rise to capillaries from which blood drains into veins at the centre of the lobes. Maternal blood reaches the placenta through spiral arteries that pass around the perimeter of the subplacenta. They supply large maternal blood sinuses, lined by trophoblast, which run through the interlobular areas and into the centre of the lobes. Here they supply fine channels that run parallel to the fetal capillaries, so that maternal blood flows from the centre of the lobe to the periphery. This arrangement provides the morphological basis for countercurrent exchange. The maternal channels of the labyrinth drain into spaces formed by the latticework of the interlobular trophoblast and thence through venous lacunae to a basal venous lacunar ring. The subplacenta is supplied by a single fetal artery. The vessels within the subplacenta pursue a tortuous course with dilatations and constrictions as in an endocrine gland.

  15. Oscillatory Positive Expiratory Pressure in Chronic Obstructive Pulmonary Disease.

    Science.gov (United States)

    Svenningsen, Sarah; Paulin, Gregory A; Sheikh, Khadija; Guo, Fumin; Hasany, Aasim; Kirby, Miranda; Rezai, Roya Etemad; McCormack, David G; Parraga, Grace

    2016-01-01

    Evidence-based guidance for the use of airway clearance techniques (ACT) in chronic obstructive pulmonary disease (COPD) is lacking in-part because well-established measurements of pulmonary function such as the forced expiratory volume in 1s (FEV1) are relatively insensitive to ACT. The objective of this crossover study was to evaluate daily use of an oscillatory positive expiratory pressure (oPEP) device for 21-28 days in COPD patients who were self-identified as sputum-producers or non-sputum-producers. COPD volunteers provided written informed consent to daily oPEP use in a randomized crossover fashion. Participants completed baseline, crossover and study-end pulmonary function tests, St. George's Respiratory Questionnaire (SGRQ), Patient Evaluation Questionnaire (PEQ), Six-Minute Walk Test and (3)He magnetic resonance imaging (MRI) for the measurement of ventilation abnormalities using the ventilation defect percent (VDP). Fourteen COPD patients, self-identified as sputum-producers and 13 COPD-non-sputum-producers completed the study. Post-oPEP, the PEQ-ease-bringing-up-sputum was improved for sputum-producers (p = 0.005) and non-sputum-producers (p = 0.04), the magnitude of which was greater for sputum-producers (p = 0.03). There were significant post-oPEP improvements for sputum-producers only for FVC (p = 0.01), 6MWD (p = 0.04), SGRQ total score (p = 0.01) as well as PEQ-patient-global-assessment (p = 0.02). Clinically relevant post-oPEP improvements for PEQ-ease-bringing-up-sputum/PEQ-patient-global-assessment/SGRQ/VDP were observed in 8/7/9/6 of 14 sputum-producers and 2/0/3/3 of 13 non-sputum-producers. The post-oPEP change in (3)He MRI VDP was related to the change in PEQ-ease-bringing-up-sputum (r = 0.65, p = 0.0004) and FEV1 (r = -0.50, p = 0.009). In COPD patients with chronic sputum production, PEQ and SGRQ scores, FVC and 6MWD improved post-oPEP. FEV1 and PEQ-ease-bringing-up-sputum improvements were related to improved ventilation providing

  16. Analysis of the XRCC1 gene as a modifier of the cerebral response in ischemic stroke

    Directory of Open Access Journals (Sweden)

    Juo Suh-Hang H

    2006-11-01

    Full Text Available Abstract Background Although there have been studies of the genetic risk factors in the development of stroke, there have been few investigations of role of genes in the cerebral response to ischemia. The brain responds to ischemia in a series of reactions that ultimately influence the volume of a stroke that, in general, correlates with disability. We hypothesize that polymorphisms in genes encoding proteins involved in these reactions could act as modifiers of this response and impact stroke volume. One of the pathways participating in the cerebral ischemic response involves reactive oxygen species which can cause oxidative damage to nucleic acids. DNA repair mechanisms are in place to protect against such damage and imply a role for DNA repair genes in the response of the brain to ischemia and are potential candidate genes for further investigation. Methods We studied two common polymorphisms in the DNA repair gene, XRCC1, C26304T and G28152A, in 134 well characterized patients with non lacunar ischemic strokes. We also performed a case control association study with 113 control patients to assess whether these variants represent risk factors in the development of ischemic stroke. Results Independent of etiology, the "T" allele of the C26304T polymorphism is significantly associated with larger stroke volumes (T-test analysis, p Conclusion Our study suggests a major gene effect of the "T" allele of the C26304T polymorphism modulating the cerebral response to ischemia in non lacunar ischemic stroke.

  17. Research and Development of a Chaotic Signal Synchronization Error Dynamics-Based Ball Bearing Fault Diagnostor

    Directory of Open Access Journals (Sweden)

    Ying-Che Kuo

    2014-10-01

    Full Text Available This paper describes the fault diagnosis in the operation of industrial ball bearings. In order to cluster the very small differential signals of the four classic fault types of the ball bearing system, the chaos synchronization (CS concept is used in this study as the chaos system is very sensitive to a system’s variation such as initial conditions or system parameters. In this study, the Chen-Lee chaotic system was used to load the normal and fault signals of the bearings into the chaos synchronization error dynamics system. The fractal theory was applied to determine the fractal dimension and lacunarity from the CS error dynamics. Extenics theory was then applied to distinguish the state of the bearing faults. This study also compared the proposed method with discrete Fourier transform and wavelet packet analysis. According to the results, it is shown that the proposed chaos synchronization method combined with extenics theory can separate the characteristics (fractal dimension vs. lacunarity completely. Therefore, it has a better fault diagnosis rate than the two traditional signal processing methods, i.e., Fourier transform and wavelet packet analysis combined with extenics theory.

  18. Effects of ghrelin on the structural complexity of exocrine pancreas tissue architecture.

    Science.gov (United States)

    Pantic, Igor; Nesic, Dejan; Stevanovic, Darko; Starcevic, Vesna; Pantic, Senka; Trajkovic, Vladimir

    2013-06-01

    Recent studies have shown that ghrelin increases pancreatic exocrine secretion. However, the potential effects of ghrelin on the morphology of exocrine pancreas (EP) remain unknown. In this work, using fractal analysis, we demonstrate that centrally administered ghrelin increases structural complexity and tissue disorder in rat EP. The study was carried out on a total of 40 male Wistar rats divided into four groups (n = 10): ghrelin-treated animals (average age, 1.5 months), ghrelin-treated animals (8.5 months), and controls (1.5 and 8.5 months). The pancreas tissue sections were stained with hematoxylin/eosin and visualized by light microscopy. For each animal, the average values of tissue fractal dimension, lacunarity, as well as parameters of co-occurrence matrix texture, were determined using tissue digital micrographs. The results indicate that ghrelin administration increases EP fractal dimension and textural entropy, and decreases lacunarity, regardless of the age. To our knowledge, this is the first study to investigate the effects of ghrelin on the morphological properties of pancreatic tissue, and also the first to apply fractal and textural analysis methods in quantification of EP tissue architecture.

  19. A case of thalamic hemorrhage-induced diaschisis

    Institute of Scientific and Technical Information of China (English)

    Gang Yao; Yuhong Man; Xijing Mao; Tingmin Yu

    2011-01-01

    Diaschisis refers to a disturbance (inhibition or facilitation) of function in an area remote from the site of a primary brain lesion. Previous studies have confirmed that regional cerebral blood flow and metabolism are noticeably decreased in an infarct region. Transient excessive perfusion appears in the ischemic penumbra, and diaschisis occurs in an area remote from the lesion site, showing decreased regional cerebral blood flow and metabolism. Mirror diaschisis refers to a decrease in oxygen metabolism and blood flow in the "mirror image area" to the infarct regions in the contralateral hemisphere. In this study, a patient with right thalamic hemorrhage was affected with right arm and leg numbness. At 4 months before onset, magnetic resonance imaging of the head demonstrated lacunar infarcts in the left thalamus; therefore the right arm and leg numbness was not associated with lacunar infarcts in the left thalamus. At 8 days following onset, magnetic resonance imaging reexamination did not reveal the focus that could induce right arm and leg numbness and weakness. Thus, it is suggested in this study that the onset of this disease can be explained by mirror diaschisis. That is, right thalamic hemorrhage leads to decreased blood flow and metabolic disturbance in the contralateral thalamus, resulting in right arm and leg numbness.

  20. Principal component analysis of the CT density histogram to generate parametric response maps of COPD

    Science.gov (United States)

    Zha, N.; Capaldi, D. P. I.; Pike, D.; McCormack, D. G.; Cunningham, I. A.; Parraga, G.

    2015-03-01

    Pulmonary x-ray computed tomography (CT) may be used to characterize emphysema and airways disease in patients with chronic obstructive pulmonary disease (COPD). One analysis approach - parametric response mapping (PMR) utilizes registered inspiratory and expiratory CT image volumes and CT-density-histogram thresholds, but there is no consensus regarding the threshold values used, or their clinical meaning. Principal-component-analysis (PCA) of the CT density histogram can be exploited to quantify emphysema using data-driven CT-density-histogram thresholds. Thus, the objective of this proof-of-concept demonstration was to develop a PRM approach using PCA-derived thresholds in COPD patients and ex-smokers without airflow limitation. Methods: Fifteen COPD ex-smokers and 5 normal ex-smokers were evaluated. Thoracic CT images were also acquired at full inspiration and full expiration and these images were non-rigidly co-registered. PCA was performed for the CT density histograms, from which the components with the highest eigenvalues greater than one were summed. Since the values of the principal component curve correlate directly with the variability in the sample, the maximum and minimum points on the curve were used as threshold values for the PCA-adjusted PRM technique. Results: A significant correlation was determined between conventional and PCA-adjusted PRM with 3He MRI apparent diffusion coefficient (p<0.001), with CT RA950 (p<0.0001), as well as with 3He MRI ventilation defect percent, a measurement of both small airways disease (p=0.049 and p=0.06, respectively) and emphysema (p=0.02). Conclusions: PRM generated using PCA thresholds of the CT density histogram showed significant correlations with CT and 3He MRI measurements of emphysema, but not airways disease.

  1. Skin graft vascular maturation and remodeling: a multifractal approach to morphological quantification.

    Science.gov (United States)

    Gould, Daniel J; Reece, Gregory P

    2012-10-01

    One important contributor to tissue graft viability is angiogenic maturation of the graft tissue bed. This study uses scale-invariant microvascular morphological quantification to track vessel maturation and remodeling in a split-thickness skin-grafting model over 21 days, comparing the results to classical techniques. Images from a previous study of split-thickness skin grafting in rats were analyzed. Microvascular morphology (fractal and multifractal dimensions, lacunarity, and vessel density) within fibrin interfaces of samples over time was quantified using classical semi-automated methods and automated multifractal and lacunarity analyses. Microvessel morphology increased in density and complexity, from three to seven days after engraftment and then regressed by 21 days. Vessel density increased from 0.07 on day 3 to 0.20 on day 7 and then decreased to 0.06 on day 21. A similar trend was seen for the fractal dimension that increased from 1.56 at three days to 1.77 at seven days then decreased to 1.57 by 21 days. Vessel diameters did not change whereas complexity and density did, signaling remodeling. This new automated analysis identified design parameters for tissue engraftment and could be used in other models of graft vessel biology to track proliferation and pruning of complex vessel beds. © 2012 John Wiley & Sons Ltd.

  2. Age-related reduction of chromatin fractal dimension in toluidine blue - stained hepatocytes.

    Science.gov (United States)

    Pantic, Igor; Petrovic, Danica; Paunovic, Jovana; Vucevic, Danijela; Radosavljevic, Tatjana; Pantic, Senka

    2016-07-01

    In this study, we proposed a hypothesis that chromatin of mouse hepatocytes exhibits age-related reduction of fractal dimension. This hypothesis was based on previously published works demonstrating that complexity of biological systems such as tissues, decreases during the process of physiological aging. Liver tissue was obtained from 24 male mice divided into 3 age groups: 10-days-old (young, juvenile), 210-days-old (adult) and 390-days-old. The tissue was stained using a modification of toluidine blue (nucleic acid - specific) staining method. A total of 480 chromatin structures (20 for each animal) were analyzed. For each structure, the values of fractal dimension, lacunarity, textural angular second moment and inverse difference moment were calculated using ImageJ software and its plugins. The results indicated the age-related reduction in fractal dimension and increase in lacunarity (p<0.01). Fractal dimension is a potentially good indicator of age associated changes in chromatin structure. To our knowledge, this is the first study to show that fractal complexity of hepatocyte chromatin decreases during the process of physiological aging. Fractal analysis as a method could be useful in detection of small age-related changes in chromatin distribution not otherwise visible with naked eye on conventional tissue micrographs. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. Fostering Effective Studying and Study Planning with Study Questions

    Science.gov (United States)

    Wilhelm, Pascal; Pieters, Jules M.

    2007-01-01

    In a course on biological psychology and neuropsychology, study questions were provided that also appeared as test questions in the course exam. This method was introduced to support students in active processing and reproduction of the study texts, and study planning. Data were gathered to test the hypothesis that study question use would be…

  4. Case Study: Testing with Case Studies

    Science.gov (United States)

    Herreid, Clyde Freeman

    2015-01-01

    This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue discusses using case studies to test for knowledge or lessons learned.

  5. Case Study: Testing with Case Studies

    Science.gov (United States)

    Herreid, Clyde Freeman

    2015-01-01

    This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue discusses using case studies to test for knowledge or lessons learned.

  6. On the fractal geometry of DNA by the binary image analysis.

    Science.gov (United States)

    Cattani, Carlo; Pierro, Gaetano

    2013-09-01

    The multifractal analysis of binary images of DNA is studied in order to define a methodological approach to the classification of DNA sequences. This method is based on the computation of some multifractality parameters on a suitable binary image of DNA, which takes into account the nucleotide distribution. The binary image of DNA is obtained by a dot-plot (recurrence plot) of the indicator matrix. The fractal geometry of these images is characterized by fractal dimension (FD), lacunarity, and succolarity. These parameters are compared with some other coefficients such as complexity and Shannon information entropy. It will be shown that the complexity parameters are more or less equivalent to FD, while the parameters of multifractality have different values in the sense that sequences with higher FD might have lower lacunarity and/or succolarity. In particular, the genome of Drosophila melanogaster has been considered by focusing on the chromosome 3r, which shows the highest fractality with a corresponding higher level of complexity. We will single out some results on the nucleotide distribution in 3r with respect to complexity and fractality. In particular, we will show that sequences with higher FD also have a higher frequency distribution of guanine, while low FD is characterized by the higher presence of adenine.

  7. Spatial heterogeneity analysis of brain activation in fMRI.

    Science.gov (United States)

    Gupta, Lalit; Besseling, René M H; Overvliet, Geke M; Hofman, Paul A M; de Louw, Anton; Vaessen, Maarten J; Aldenkamp, Albert P; Ulman, Shrutin; Jansen, Jacobus F A; Backes, Walter H

    2014-01-01

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

  8. Assessment of the spatial pattern of colorectal tumour perfusion estimated at perfusion CT using two-dimensional fractal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Goh, Vicky; Sanghera, Bal [Mount Vernon Hospital, Paul Strickland Scanner Centre, Northwood, Middlesex (United Kingdom); Wellsted, David M.; Sundin, Josefin [University of Hertfordshire, Research and Development Support Unit, Hatfield (United Kingdom); Halligan, Steve [University College Hospital, Department of Academic Radiology, London (United Kingdom)

    2009-06-15

    The aim was to evaluate the feasibility of fractal analysis for assessing the spatial pattern of colorectal tumour perfusion at dynamic contrast-enhanced CT (perfusion CT). Twenty patients with colorectal adenocarcinoma underwent a 65-s perfusion CT study from which a perfusion parametric map was generated using validated commercial software. The tumour was identified by an experienced radiologist, segmented via thresholding and fractal analysis applied using in-house software: fractal dimension, abundance and lacunarity were assessed for the entire outlined tumour and for selected representative areas within the tumour of low and high perfusion. Comparison was made with ten patients with normal colons, processed in a similar manner, using two-way mixed analysis of variance with statistical significance at the 5% level. Fractal values were higher in cancer than normal colon (p {<=} 0.001): mean (SD) 1.71 (0.07) versus 1.61 (0.07) for fractal dimension and 7.82 (0.62) and 6.89 (0.47) for fractal abundance. Fractal values were lower in 'high' than 'low' perfusion areas. Lacunarity curves were shifted to the right for cancer compared with normal colon. In conclusion, colorectal cancer mapped by perfusion CT demonstrates fractal properties. Fractal analysis is feasible, potentially providing a quantitative measure of the spatial pattern of tumour perfusion. (orig.)

  9. Iron oxide nanoparticles decrease nuclear fractal dimension of buccal epithelial cells in a time-dependent manner.

    Science.gov (United States)

    Nikolovski, D; Dugalic, S; Pantic, I

    2017-05-23

    In this paper, we present results that iron oxide nanoparticles (IONPs) induce time-dependent structural changes in nuclei of buccal epithelial cells. The cells were treated with magnetite, Fe3 O4 nanoparticles (spherical shape, diameter 80-100 nanometres). The digital micrographs of the nuclei were made in 3 different time points: 15, 30 and 60 min after the treatment with IONPs, as well as in the control cells. A total of 120 nuclear structures (30 per sample) were analysed. Fractal analysis of nuclei was done in ImageJ software of the National Institutes of Health, (Bethesda, MD, USA). For each nuclear structure, the values of fractal dimension and lacunarity were calculated. There was a time-dependent reduction of nuclear fractal dimension in buccal epithelial cells after exposure to magnetite iron oxide nanoparticles. Negative trend was observed (p lacunarity, as another fractal parameter was shown to increase, also in a time-dependent manner, after the treatment with IONPs. To our knowledge, this is the first study to investigate effects of magnetite nanomaterial on nuclear fractal complexity, and also the first to apply fractal analysis method in testing of the interaction between nanoparticles and cell nucleus in this experimental setting. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  10. Fractal analysis and Gray level co-occurrence matrix method for evaluation of reperfusion injury in kidney medulla.

    Science.gov (United States)

    Pantic, Igor; Nesic, Zorica; Paunovic Pantic, Jovana; Radojević-Škodrić, Sanja; Cetkovic, Mila; Basta Jovanovic, Gordana

    2016-05-21

    Fractal analysis and Gray level co-occurrence matrix method represent two novel mathematical algorithms commonly used in medical sciences as potential parts of computer-aided diagnostic systems. In this study, we tested the ability of these methods to discriminate the kidney medullar tissue suffering from reperfusion injury, from normal tissue. A total of 320 digital micrographs of Periodic acid-Schiff (PAS) - stained kidney medulla from 16 Wistar albino mice (20 per animal), were analyzed using National Institutes of Health ImageJ software (NIH, Bethesda, MD) and its plugins. 160 micrographs were obtained from the experimental group with induced reperfusion injury, and another 160 were obtained from the controls. For each micrograph we calculated the values of fractal dimension, lacunarity, as well as five GLCM features: angular second moment, entropy, inverse difference moment, GLCM contrast, and GLCM correlation. Discriminatory value of the parameters was tested using receiver operating characteristic (ROC) analysis, by measuring the area below ROC curve. The results indicate that certain features of GLCM algorithm have excellent discriminatory ability in evaluation of damaged kidney tissue. Fractal dimension and lacunarity as parameters of fractal analysis also had a relatively good discriminatory value in differentiation of injured from the normal tissue. Both methods have potentially promising application in future design of novel techniques applicable in cell physiology, histology and pathology. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Mechanical stability of end-linked polymer gel

    Energy Technology Data Exchange (ETDEWEB)

    Roy Majumder, Shashwati [Theoretical Chemistry Section, Radiation Chemistry and Chemical Dynamics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Bandyopadhyay, Tusar [Theoretical Chemistry Section, Radiation Chemistry and Chemical Dynamics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)]. E-mail: btusar@barc.ernet.in; Ghosh, Swapan K. [Theoretical Chemistry Section, Radiation Chemistry and Chemical Dynamics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2005-11-01

    The mechanical stability of end-linked polymer network (gel) at large deformation has been studied with the aid of a simplified model. The model consists of square network of end-linked Hookean spring, each representing an ideal polymer chain. To mimic the structure prevailing at the gel point, the square network of springs was self-similarly repeated to generate a deterministic fractal structure having fractal dimensions, d{sub f}=1.56-1.8. For any given d{sub f}, the distribution of pores (measured by lacunarity of the network) in the structure also serves as an important parameter that characterizes the morphology of the network. Our preliminary results show that the present minimalist model qualitatively reproduces the non-monotonous structure-stability relationship, as observed in radiation-induced cross-linked polymer networks. Structures with highest lacunarity for a given fractal network have also been found to exhibit highest mechanical stability against an external deforming force before it is finally crumpled and found to form a wrinkled network.

  12. An analysis of Methylenetetrahydrofolate reductase and Glutathione S-transferase omega-1 genes as modifiers of the cerebral response to ischemia

    Directory of Open Access Journals (Sweden)

    Sen Souvik

    2009-07-01

    Full Text Available Abstract Background Cerebral ischemia involves a series of reactions which ultimately influence the final volume of a brain infarction. We hypothesize that polymorphisms in genes encoding proteins involved in these reactions could act as modifiers of the cerebral response to ischemia and impact the resultant stroke volume. The final volume of a cerebral infarct is important as it correlates with the morbidity and mortality associated with non-lacunar ischemic strokes. Methods The proteins encoded by the methylenetetrahydrofolate reductase (MTHFR and glutathione S-transferase omega-1 (GSTO-1 genes are, through oxidative mechanisms, key participants in the cerebral response to ischemia. On the basis of these biological activities, they were selected as candidate genes for further investigation. We analyzed the C677T polymorphism in the MTHFR gene and the C419A polymorphism in the GSTO-1 gene in 128 patients with non-lacunar ischemic strokes. Results We found no significant association of either the MTHFR (p = 0.72 or GSTO-1 (p = 0.58 polymorphisms with cerebral infarct volume. Conclusion Our study shows no major gene effect of either the MTHFR or GSTO-1 genes as a modifier of ischemic stroke volume. However, given the relatively small sample size, a minor gene effect is not excluded by this investigation.

  13. On the fractal distribution of primes and prime-indexed primes by the binary image analysis

    Science.gov (United States)

    Cattani, Carlo; Ciancio, Armando

    2016-10-01

    In this paper, the distribution of primes and prime-indexed primes (PIPs) is studied by mapping primes into a binary image which visualizes the distribution of primes. These images show that the distribution of primes (and PIPs) is similar to a Cantor dust, moreover the self-similarity with respect to the order of PIPs (already proven in Batchko (2014)) can be seen as an invariance of the binary images. The index of primes plays the same role of the scale for fractals, so that with respect to the index the distribution of prime-indexed primes is characterized by the self-similarity alike any other fractal. In particular, in order to single out the scale dependence, the PIPs fractal distribution will be evaluated by limiting to two parameters, fractal dimension (δ) and lacunarity (λ), that are usually used to measure the fractal nature. Because of the invariance of the corresponding binary plots, the fractal dimension and lacunarity of primes distribution are invariant with respect to the index of PIPs.

  14. An Inflammatory Polymorphisms Risk Scoring System for the Differentiation of Ischemic Stroke Subtypes

    Science.gov (United States)

    Muiño, Elena; Krupinski, Jurek; Carrera, Caty; Gallego-Fabrega, Cristina; Montaner, Joan; Fernández-Cadenas, Israel

    2015-01-01

    Inflammation has been associated with atherothrombotic stroke and recently with cardioembolic stroke. Different genetic risk factors have been specifically associated with the subtypes of ischemic stroke (cardioembolic, atherothrombotic, and lacunar). However, there are no studies that have generated genetic risk scores for the different subtypes of ischemic stroke using polymorphisms associated with inflammation. Methods. We have analyzed 68 polymorphisms of 30 inflammatory mediator genes in 2,685 subjects: 1,987 stroke cases and 698 controls. We generated a genetic scoring system with the most significant polymorphisms weighted by the odds ratio of every polymorphism and taken into consideration the stroke subtype. Results. Three polymorphisms, rs1205 (CRP gene), rs1800779, and rs2257073 (NOS3 gene), were associated with cardioembolic stroke (p value stroke subtype (p value: 0.001) and was replicated in an independent cohort (p value: 0.017). The subjects with the highest score presented a cardioembolic stroke in 92.2% of the cases (p value: 0.002). Conclusion. The genetics of inflammatory markers is more closely associated with cardioembolic strokes than with atherothrombotic or lacunar strokes. The genetic risk scoring system could be useful in the prediction and differentiation of ischemic stroke; however, it might be specific to particular ischemic stroke subtypes. PMID:26355258

  15. Ovariectomy Enhances Mechanical Load-Induced Solute Transport around Osteocytes in Rat Cancellous Bone

    Science.gov (United States)

    Ciani, Cesare; Sharma, Divya; Doty, Stephen B.; Fritton, Susannah P.

    2014-01-01

    To test if osteoporosis alters mechanical load-induced interstitial fluid flow in bone, this study examined the combined effect of estrogen deficiency and external loading on solute transport around osteocytes. An in vivo tracer, FITC-labeled bovine serum albumin, was injected into anaesthetized ovariectomized and control female Sprague Dawley rats before the right tibia was subjected to a controlled, physiological, non-invasive sinusoidal load to mimic walking. Tracer movement through the lacunar-canalicular system surrounding osteocytes was quantified in cortical and cancellous bone from the proximal tibia using confocal microscopy, with the non-loaded tibia serving as internal control. Overall, the application of mechanical loading increased the percentage of osteocyte lacunae labeled with injected tracer, and ovariectomy further enhanced movement of tracer. An analysis of separate regions demonstrated that ovariectomy enhanced in vivo transport of the injected tracer in the cancellous bone of the tibial epiphysis and metaphysis but not in the cortical bone of the metaphysis. These findings show that bone changes due to reduced estrogen levels alter convectional transport around osteocytes in cancellous bone and demonstrate a functional difference of interstitial fluid flow around osteocytes in estrogen-deficient rats undergoing the same physical activity as controls. The altered interstitial fluid flow around osteocytes is likely related to nanostructural matrix-mineral level differences recently demonstrated at the lacunar-canalicular surface of estrogen-deficient rats, which could affect the transmission of mechanical loads to the osteocyte. PMID:24316418

  16. Impaired executive function following ischemic stroke in the rat medial prefrontal cortex.

    Science.gov (United States)

    Cordova, Chris A; Jackson, Danielle; Langdon, Kristopher D; Hewlett, Krista A; Corbett, Dale

    2014-01-01

    Small (lacunar) infarcts frequently arise in frontal and midline thalamic regions in the absence of major stroke. Damage to these areas often leads to impairment of executive function likely as a result of interrupting connections of the prefrontal cortex. Thus, patients experience frontal-like symptoms such as impaired ability to shift ongoing behavior and attention. In contrast, executive dysfunction has not been demonstrated in rodent models of stroke, thereby limiting the development of potential therapies for human executive dysfunction. Male Sprague-Dawley rats (n=40) underwent either sham surgery or bilateral endothelin-1 injections in the mediodorsal nucleus of the thalamus or in the medial prefrontal cortex. Executive function was assessed using a rodent attention set shifting test that requires animals to shift attention to stimuli in different stimulus dimensions. Medial prefrontal cortex ischemia impaired attention shift performance between different stimulus dimensions while sparing stimulus discrimination and attention shifts within a stimulus dimension, indicating a selective attention set-shift deficit. Rats with mediodorsal thalamic lacunar damage did not exhibit a cognitive impairment relative to sham controls. The selective attention set shift impairment observed in this study is consistent with clinical data demonstrating selective executive disorders following stroke within specific sub-regions of frontal cortex. These data contribute to the development and validation of a preclinical animal model of executive dysfunction, that can be employed to identify potential therapies for ameliorating cognitive deficits following stroke.

  17. Cerebral hemodynamic dysfunction in parkinsonian patients

    Directory of Open Access Journals (Sweden)

    Mirjana Vladetić

    2009-02-01

    Full Text Available Aim The purpose of this investigation was to determine the cerebral hemodynamics in patients withparkinsonism and the influence of hemodynamic dysfunction in developing the lacunar infarcts.Methods Fifty patients with the signs of parkinsonism were included in this study. The patients weredevided into two subgroups depending on whether they had vascular parkinsonism (VP (N-22 or idiopathicParkinson disease (N-28. The control group consisted of 30 patients who had ischemic stroke.The conventional transcranial dopler sonography was performed to evaluate the cerebral blood flow.To evaluate the cognitive impairment we performed the mini mental state examination to patients withparkinsonism.Results Patients with vascular parkinsonism have greater cognitive disturbances than patients withParkinson disease. In most of the parkinsonian patients the cerebral blood flow was decreased and themicroangiopathy was present.Conclusion In most patients with parkinsonism, the cerebral blood flow was decreased as a consequenceof microangiopathy. In our opinion, this led to lacunar infarction in VP patients, but can also bea risk factor for developing the same changes in patients with idiopathic Parkinson disease.

  18. Aortic stiffness is associated with cardiac function and cerebral small vessel disease in patients with type 1 diabetes mellitus: assessment by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Elderen, Saskia G.C. van; Brandts, A.; Westenberg, J.J.M.; Grond, J. van der; Buchem, M.A. van; Kroft, L.J.M.; Roos, A. de [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Tamsma, J.T.; Romijn, J.A.; Smit, J.W.A. [Leiden University Medical Center, Department of Endocrinology, Leiden (Netherlands)

    2010-05-15

    To evaluate, with the use of magnetic resonance imaging (MRI), whether aortic pulse wave velocity (PWV) is associated with cardiac left ventricular (LV) function and mass as well as with cerebral small vessel disease in patients with type 1 diabetes mellitus (DM). We included 86 consecutive type 1 DM patients (49 male, mean age 46.9 {+-} 11.7 years) in a prospective, cross-sectional study. Exclusion criteria included aortic/heart disease and general MRI contra-indications. MRI of the aorta, heart and brain was performed for assessment of aortic PWV, as a marker of aortic stiffness, systolic LV function and mass, as well as for the presence of cerebral white matter hyperintensities (WMHs), microbleeds and lacunar infarcts. Multivariate linear or logistic regression was performed to analyse the association between aortic PWV and outcome parameters, with covariates defined as age, gender, mean arterial pressure, heart rate, BMI, smoking, DM duration and hypertension. Mean aortic PWV was 7.1 {+-} 2.5 m/s. Aortic PWV was independently associated with LV ejection fraction (ss= -0.406, P = 0.006), LV stroke volume (ss=-0.407, P = 0.001), LV cardiac output (ss= -0.458, P = 0.001), and with cerebral WMHs (P < 0.05). There were no independent associations between aortic stiffness and LV mass, cerebral microbleeds or lacunar infarcts. Aortic stiffness is independently associated with systolic LV function and cerebral WMHs in patients with type 1 DM. (orig.)

  19. The role of calcium and nicotinic acid adenine dinucleotide phosphate (NAADP) in human osteoclast formation and resorption.

    Science.gov (United States)

    Cheng, X; Hookway, E S; Kashima, T; Oppermann, U; Galione, A; Athanasou, N A

    2015-01-01

    Osteoclasts are specialised bone resorbing cells which form by fusion of circulating mononuclear phagocyte precursors. Bone resorption results in the release of large amounts of calcium into the extracellular fluid (ECF), but it is not certain whether changes in extracellular calcium concentration [Ca(2+)]e influence osteoclast formation and resorption. In this study, we sought to determine the effect of [Ca(2+)]e and NAADP, a potent calcium mobilising messenger that induces calcium uptake, on human osteoclast formation and resorption. CD14+ human monocytes were cultured with M-CSF and RANKL in the presence of different concentrations of calcium and NAADP and the effect on osteoclast formation and resorption evaluated. We found that the number of TRAP+ multinucleated cells and the extent of lacunar resorption were reduced when there was an increase in extracellular calcium and NAADP. This was associated with a decrease in RANK mRNA expression by CD14+ cells. At high concentrations (20 mM) of [Ca(2+)]e mature osteoclast resorption activity remained unaltered relative to control cultures. Our findings indicate that osteoclast formation is inhibited by a rise in [Ca(2+)]e and that RANK expression by mononuclear phagocyte osteoclast precursors is also [Ca(2+)]e dependent. Changes in NAADP also influence osteoclast formation, suggesting a role for this molecule in calcium handling. Osteoclasts remained capable of lacunar resorption, even at high ECF [Ca(2+)]e, in keeping with their role in physiological and pathological bone resorption.

  20. Spatial heterogeneity analysis of brain activation in fMRI

    Directory of Open Access Journals (Sweden)

    Lalit Gupta

    2014-01-01

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

  1. An Inflammatory Polymorphisms Risk Scoring System for the Differentiation of Ischemic Stroke Subtypes

    Directory of Open Access Journals (Sweden)

    Elena Muiño

    2015-01-01

    Full Text Available Inflammation has been associated with atherothrombotic stroke and recently with cardioembolic stroke. Different genetic risk factors have been specifically associated with the subtypes of ischemic stroke (cardioembolic, atherothrombotic, and lacunar. However, there are no studies that have generated genetic risk scores for the different subtypes of ischemic stroke using polymorphisms associated with inflammation. Methods. We have analyzed 68 polymorphisms of 30 inflammatory mediator genes in 2,685 subjects: 1,987 stroke cases and 698 controls. We generated a genetic scoring system with the most significant polymorphisms weighted by the odds ratio of every polymorphism and taken into consideration the stroke subtype. Results. Three polymorphisms, rs1205 (CRP gene, rs1800779, and rs2257073 (NOS3 gene, were associated with cardioembolic stroke (p value <0.05. The score generated was only associated with the cardioembolic stroke subtype (p value: 0.001 and was replicated in an independent cohort (p value: 0.017. The subjects with the highest score presented a cardioembolic stroke in 92.2% of the cases (p value: 0.002. Conclusion. The genetics of inflammatory markers is more closely associated with cardioembolic strokes than with atherothrombotic or lacunar strokes. The genetic risk scoring system could be useful in the prediction and differentiation of ischemic stroke; however, it might be specific to particular ischemic stroke subtypes.

  2. Case Study: Writing a Journal Case Study

    Science.gov (United States)

    Prud'homme-Genereux, Annie

    2016-01-01

    This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue describes incorporating a journal article into the classroom by first converting it into a case study.

  3. Case Study: Writing a Journal Case Study

    Science.gov (United States)

    Prud'homme-Genereux, Annie

    2016-01-01

    This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue describes incorporating a journal article into the classroom by first converting it into a case study.

  4. Paraguayan Education Study: A Pilot Study.

    Science.gov (United States)

    Garcia, Patricia

    A qualitative pilot study, guided by an ecological framework, illustrates the complexities involved in studying the unique linguistic situation in Paraguay between Spanish and the indigenous language of Guarani, and its relationship with education. The pilot study interviewing eight kindergarten children. Seventy five children have been…

  5. Islands, Island Studies, Island Studies Journal

    Directory of Open Access Journals (Sweden)

    Godfrey Baldacchino

    2006-05-01

    Full Text Available Islands are sites of innovative conceptualizations, whether of nature or human enterprise, whether virtual or real. The study of islands on their own terms today enjoys a growing and wide-ranging recognition. This paper celebrates the launch of Island Studies Journal in the context of a long and thrilling tradition of island studies scholarship.

  6. Feasibibility study - cases

    DEFF Research Database (Denmark)

    2004-01-01

    The chapter presents two case studies to show the tools of feasibiliy studies within the context of technological innovation.......The chapter presents two case studies to show the tools of feasibiliy studies within the context of technological innovation....

  7. German Studies in America. German Studies Notes.

    Science.gov (United States)

    Sander, Volkmar; Osterle, Heinz D.

    This volume contains two papers, "German Studies in America," by Volkmar Sander, and "Historicism, Marxism, Structuralism: Ideas for German Culture Courses," by Heinz D. Osterle. The first paper discusses the position of German studies in the United States today. The greatest challenge comes from low enrollments; therefore,…

  8. German Studies in America. German Studies Notes.

    Science.gov (United States)

    Sander, Volkmar; Osterle, Heinz D.

    This volume contains two papers, "German Studies in America," by Volkmar Sander, and "Historicism, Marxism, Structuralism: Ideas for German Culture Courses," by Heinz D. Osterle. The first paper discusses the position of German studies in the United States today. The greatest challenge comes from low enrollments; therefore,…

  9. Humanities, Digital Humanities, Media studies, Internet studies

    DEFF Research Database (Denmark)

    Brügger, Niels

    the interplay between four areas which until now to a certain extent have been separated: Traditional Hu- manities, Digital Humanities, Media studies, and Internet studies. The vision is followed by an outline of how it can be unfolded in concrete activities, in the form of research projects, research...

  10. Study of lip prints: A forensic study

    Directory of Open Access Journals (Sweden)

    Vikash Ranjan

    2014-01-01

    Full Text Available Background: Although several studies have been done on lip prints for human identification in forensic science, there is a doubt about their use in gender determination. Aims: The present study was designed to study the lip groove patterns in all the quadrants of both male and female subjects to identify the sex, based on the patterns of the grooves of the lip prints. Study Design: 300 lip prints were collected from volunteers of D. J. College of Dental Sciences and Research, Modinagar (UP. Materials and Methods: Lip prints were recorded with lip stick and transferred on to a glass slide. Statistical Analysis: Pearson chi-square test was adopted for statistical analysis and probability value (P value was calculated. Conclusion: In our study, none of the lip prints were identical, thus confirming the role of lip prints in individual identification. According to Suzuki′s classification, Type I, II, III and IV patterns were significant in gender determination.

  11. Humanities, Digital Humanities, Media studies, Internet studies

    DEFF Research Database (Denmark)

    Brügger, Niels

    the interplay between four areas which until now to a certain extent have been separated: Traditional Hu- manities, Digital Humanities, Media studies, and Internet studies. The vision is followed by an outline of how it can be unfolded in concrete activities, in the form of research projects, research......Todays expanding digital landscape constitutes an important research object as well as the research environment for the Humanities at the beginning of the 21st century. Taking this state of affairs as a starting point this inaugural lecture presents a vision for how the digital affects...

  12. Physics studies in Europe; a comparative study

    NARCIS (Netherlands)

    Steenstrup, S; dalle Rose, LFD; Jones, WG; Tugulea, L; van Steenwijk, FJ

    What are the differences and similarities between physics studies at different universities across Europe (here the definition of Europe is broad)? How much does a student have to work to obtain a degree in physics? Questions like those prompted EUPEN (European Physics Education Network) to make a

  13. Case study research.

    Science.gov (United States)

    Taylor, Ruth; Thomas-Gregory, Annette

    2015-06-10

    This article describes case study research for nursing and healthcare practice. Case study research offers the researcher an approach by which a phenomenon can be investigated from multiple perspectives within a bounded context, allowing the researcher to provide a 'thick' description of the phenomenon. Although case study research is a flexible approach for the investigation of complex nursing and healthcare issues, it has methodological challenges, often associated with the multiple methods used in individual studies. These are explored through examples of case study research carried out in practice and education settings. An overview of what constitutes 'good' case study research is proposed.

  14. Case Study Teaching

    Science.gov (United States)

    Herreid, Clyde Freeman

    2011-01-01

    This chapter describes the history of case study teaching, types of cases, and experimental data supporting their effectiveness. It also describes a model for comparing the efficacy of the various case study methods. (Contains 1 figure.)

  15. Case Study Teaching

    Science.gov (United States)

    Herreid, Clyde Freeman

    2011-01-01

    This chapter describes the history of case study teaching, types of cases, and experimental data supporting their effectiveness. It also describes a model for comparing the efficacy of the various case study methods. (Contains 1 figure.)

  16. Chemical Industry Bandwidth Study

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2006-12-01

    The Chemical Bandwidth Study provides a snapshot of potentially recoverable energy losses during chemical manufacturing. The advantage of this study is the use of "exergy" analysis as a tool for pinpointing inefficiencies.

  17. FEMA DFIRM Study Info

    Data.gov (United States)

    Minnesota Department of Natural Resources — This table contains details about the study such as the study name, datum, projection, etc. There is normally only one record in this table for each Flood Insurance...

  18. 522 Postmarket Surveillance Studies

    Data.gov (United States)

    U.S. Department of Health & Human Services — The 522 Postmarket Surveillance Studies Program encompasses design, tracking, oversight, and review responsibilities for studies mandated under section 522 of the...

  19. Future Circular Collider Study

    CERN Document Server

    Benedikt, Michael

    2014-01-01

    This presentation has been given during the 1st EuCARD-2 annual meeting. It contains: • Motivation & scope • Parameters & design challenges • Study organization, study time line • Preparing global FCC collaboration • Summary

  20. The People Study

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The authors of this study are participants in a National Science Foundation ( NSF) supported grant entitled "Mathematical Studies in Modeling at Mount St. Mary's...

  1. Post-Approval Studies

    Data.gov (United States)

    U.S. Department of Health & Human Services — The CDRH Post-Approval Studies Program encompasses design, tracking, oversight, and review responsibilities for studies mandated as a condition of approval of a...

  2. Modoc wetlands study plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Study plan for Modoc Wetlands Study: An assessment of the probable responses of selected wildlife to wetlands management on the Modoc National Forest.

  3. 522 Postmarket Surveillance Studies

    Data.gov (United States)

    U.S. Department of Health & Human Services — The 522 Postmarket Surveillance Studies Program encompasses design, tracking, oversight, and review responsibilities for studies mandated under section 522 of the...

  4. Air Manganese Study

    Science.gov (United States)

    In November 2011 US EPA researchers conducted a health study of airborne manganese exposure in East Liverpool, Ohio. This Web site discusses preliminary results of the study and provides background and other related information.

  5. Cerebrovascular risk factors and clinical classification of strokes.

    Science.gov (United States)

    Pinto, Antonio; Tuttolomondo, Antonino; Di Raimondo, Domenico; Fernandez, Paola; Licata, Giuseppe

    2004-08-01

    Cerebrovascular risk represents a progressive and evolving concept owing to the particular distribution of risk factors in patients with ischemic stroke and in light of the newest stroke subtype classifications that account for pathophysiological, instrumental, and clinical criteria. Age represents the strongest nonmodifiable risk factor associated with ischemic stroke, while hypertension constitutes the most important modifiable cerebrovascular risk factor, confirmed by a host of epidemiological data and by more recent intervention trials of primary (HOT, Syst-Eur, LIFE) and secondary (PROGRESS) prevention of stroke in hypertensive patients. To be sure, a curious relationship exists between stroke and diabetes. Although the Framingham Study, The Honolulu Heart Program, and a series of Finnish studies reported a linear relationship between improved glucose metabolism and cerebral ischemia, the clinical and prognostic profile of diabetic patients with ischemic stroke remains to be fully understood. Our group, on the basis of TOAST classification--a diagnostic classification of ischemic stroke developed in 1993 that distinguishes five different clinical subtypes of ischemic stroke: large-artery atherosclerosis (LAAS), cardioembolic infarct (CEI), lacunar infarct (LAC), stroke of other determined origin (ODE), and stroke of undetermined origin (UDE), and now extensively used in clinical and scientific context--analysed the prevalence of cerebrovascular risk factors and the distribution of TOAST subtypes in more 300 patients with acute ischemic stroke in two consecutives studies that reported the significant association between diabetes and the lacunar subtype and a better clinical outcome for diabetic patients, most likely related to the higher prevalence of the lacunar subtype. Well-confirmed are the roles of cigarette smoking, atrial fibrillation, and asymptomatic carotid stenosis as cerebrovascular risk factors. Particularly interesting seems to be the function of

  6. Mechanisms of osteocyte stimulation in osteoporosis.

    Science.gov (United States)

    Verbruggen, Stefaan W; Vaughan, Ted J; McNamara, Laoise M

    2016-09-01

    Experimental studies have shown that primary osteoporosis caused by oestrogen-deficiency results in localised alterations in bone tissue properties and mineral composition. Additionally, changes to the lacunar-canalicular architecture surrounding the mechanosensitive osteocyte have been observed in animal models of the disease. Recently, it has also been demonstrated that the mechanical stimulation sensed by osteocytes changes significantly during osteoporosis. Specifically, it was shown that osteoporotic bone cells experience higher maximum strains than healthy bone cells after short durations of oestrogen deficiency. However, in long-term oestrogen deficiency there was no significant difference between bone cells in healthy and normal bone. The mechanisms by which these changes arise are unknown. In this study, we test the hypothesis that complex changes in tissue composition and lacunar-canalicular architecture during osteoporosis alter the mechanical stimulation of the osteocyte. The objective of this research is to employ computational methods to investigate the relationship between changes in bone tissue composition and microstructure and the mechanical stimulation of osteocytes during osteoporosis. By simulating physiological loading, it was observed that an initial decrease in tissue stiffness (of 0.425GPa) and mineral content (of 0.66wt% Ca) relative to controls could explain the mechanical stimulation observed at the early stages of oestrogen deficiency (5 weeks post-OVX) during in situ bone cell loading in an oestrogen-deficient rat model of post-menopausal osteoporosis (Verbruggen et al., 2015). Moreover, it was found that a later increase in stiffness (of 1.175GPa) and mineral content (of 1.64wt% Ca) during long-term osteoporosis (34 weeks post-OVX), could explain the mechanical stimuli previously observed at a later time point due to the progression of osteoporosis. Furthermore, changes in canalicular tortuosity arising during osteoporosis were shown

  7. CISSP study guide

    CERN Document Server

    Conrad, Eric; Feldman, Joshua; Riggins, Kevin

    2011-01-01

    "The Eleventh Hour CISSP Study Guide" is keyed to the latest CISSP exam. This book is streamlined to include only core certification information and is presented for ease of last-minute studying. Main objectives of the exam are covered concisely with key concepts highlighted. This is the only guide you need for last-minute studying. This title answers the toughest questions and highlights core topics. This title can be paired with any other study guide so you are completely prepared.

  8. Pyridostigmine Synergistic Toxicity Study.

    Science.gov (United States)

    1995-05-31

    AND DEET IN THE LABORATORY RAT 1. Executive Sum m ary .............................................................................................. 2 2...TOXICOLOGICAL STUDY 75-48-2665 ACUTE ORAL TOXICITY STUDY OF PYRIDOSTIGMINE BROMIDE. PERMETHRIN. AND DEET IN THE LABORATORY RAT 1. REFERENCES: See Appendix A... LABORATORY RAT 1. PURPOSE: The purpose of this study was to determine potential toxic interactions when pyridostigmine bromide. permethrin. and DEET are given

  9. national Case study

    African Journals Online (AJOL)

    from this, the national case study begins to conceptualise a new approach to ... teacher education environments and a piloting of a 'Train the Trainers' or .... Study) and TIMMS (Trends in International Mathematics and Science Study) ..... Objective 7: Publish the materials in an open learning system format and integrate the.

  10. STUDYING ON THE INTERNET

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    正Nowadays the Internet is more and more popular.I think it is a good way of learning. First,the Intemet enables people to study whenever and wherever it is convenient. They can also choose to study whatever they are interested in.However,a traditional school doesn't provide such great freedom.Students have to study given sub-

  11. Social Psychoanalytic Disability Studies

    Science.gov (United States)

    Goodley, Dan

    2011-01-01

    This paper explores connections and tensions between psychoanalysis and disability studies. The first part of the paper considers contemporaneous engagements with the psyche by a number of disability studies writers. These scholars have remained accountable to a politicised disability studies but have pushed for critical encounters with the…

  12. Study deep geothermal energy; Studie dypgeotermisk energi

    Energy Technology Data Exchange (ETDEWEB)

    Havellen, Vidar; Eri, Lars Sigurd; Andersen, Andreas; Tuttle, Kevin J.; Ruden, Dorottya Bartucz; Ruden, Fridtjof; Rigler, Balazs; Pascal, Christophe; Larsen, Bjoern Tore

    2012-07-01

    The study aims to analyze the potential energy with current technology, challenges, issues and opportunities for deep geothermal energy using quantitative analysis. It should especially be made to identify and investigate critical connections between geothermal potential, the size of the heating requirements and technical solutions. Examples of critical relationships may be acceptable cost of technology in relation to heating, local geothermal gradient / drilling depth / temperature levels and profitability. (eb)

  13. Studying Engineering Practice

    DEFF Research Database (Denmark)

    Buch, Anders

    2015-01-01

    The study of engineering practices has been the focus of Engineering Studies over the last three decades. Theses studies have used ethnographic and grounded methods in order to investigate engineering practices as they unfold in natural settings - in workplaces and engineering education. However......, engineering studies have not given much attention to conceptually clarifying what should be understood by 'engineering practices' and more precisely account for the composition and organization of the entities and phenomena that make up the practices. This chapter investigates and discusses how a 'practice...... will draw out some methodological consequences and discuss the ramifications of a practice theoretical approach for Engineering Studies....

  14. Studying Engineering Practice

    DEFF Research Database (Denmark)

    Buch, Anders

    2015-01-01

    The study of engineering practices has been the focus of Engineering Studies over the last three decades. Theses studies have used ethnographic and grounded methods in order to investigate engineering practices as they unfold in natural settings - in workplaces and engineering education. However......, engineering studies have not given much attention to conceptually clarifying what should be understood by 'engineering practices' and more precisely account for the composition and organization of the entities and phenomena that make up the practices. This chapter investigates and discusses how a 'practice...... will draw out some methodological consequences and discuss the ramifications of a practice theoretical approach for Engineering Studies....

  15. Event studies in Turkey

    Directory of Open Access Journals (Sweden)

    Ulkem Basdas

    2014-09-01

    Full Text Available The primary goal of this paper is to review the event studies conducted for Turkey to in order to identify the common components in their designs. This paper contributes to the existing literature by reviewing all event studies for Turkey for the first time, but more importantly; this review leads to the upcoming event studies on Turkey by highlighting main components of a proper design. Based on the review of 75 studies, it is observed that event studies generally choose BIST-100 (formerly, ISE-100 market index and market adjusted returns with the parametric tests. In general, the studies prefer to rely on one type of model to calculate abnormal returns without discussing the selection of the underlying model. Especially for the event studies focusing on the impact of political events or macroeconomic announcements in Turkey, there is a risk of clustering due to the application of same event date for all observations.

  16. Time-lapsed assessment of microcrack initiation and propagation in murine cortical bone at submicrometer resolution.

    Science.gov (United States)

    Voide, R; Schneider, P; Stauber, M; Wyss, P; Stampanoni, M; Sennhauser, U; van Lenthe, G H; Müller, R

    2009-08-01

    The strength of bone tissue is not only determined by its mass, but also by other properties usually referred to as bone quality, such as microarchitecture, distribution of bone cells, or microcracks and damage. It has been hypothesized that the bone ultrastructure affects microcrack initiation and propagation. Due to its high resolution, bone assessment by means of synchrotron radiation (SR)-based computed tomography (CT) allows unprecedented three-dimensional (3D) and non-invasive insights into ultrastructural bone phenotypes, such as the canal network and the osteocyte lacunar system. The aims of this study were to describe the initiation and propagation of microcracks and their relation with these ultrastructural phenotypes. To this end, femora from the two genetically distinct inbred mouse strains C3H/He (C3H) and C57BL/6 (B6) were loaded axially under compression, from 0% strain to failure, with 1% strain steps. Between each step, a high-resolution 3D image (700 nm nominal resolution) was acquired at the mid-diaphysis using SR CT for characterization and quantitative analysis of the intracortical porosity, namely the bone canal network, the osteocyte lacunar system and the emerging microcracks. For C3H mice, the canal, lacunar, and microcrack volume densities accounted typically for 1.91%, 2.11%, and 0.27% of the cortical total volume at 2% apparent strain, respectively. Due to its 3D nature, SR CT allowed to visualize and quantify also the volumetric extent of microcracks. At 2% apparent strain, the average microcrack thickness for both mouse strains was 2.0 microm for example. Microcracks initiated at canal and at bone surfaces, whereas osteocyte lacunae provided guidance to the microcracks. Moreover, we observed that microcracks could appear as linear cracks in one plane, but as diffuse cracks in a perpendicular plane. Finally, SR CT images permitted visualization of uncracked ligament bridging, which is thought to be of importance in bone toughening

  17. Advanced Clothing Studies

    Science.gov (United States)

    Orndoff, Evelyne; Poritz, Darwin

    2014-01-01

    All human space missions require significant logistical mass and volume that add an unprecedented burden on longduration missions beyond low-Earth orbit. For these missions with limited cleaning resources, a new wardrobe must be developed to reduce this logistical burden by reducing clothing mass and extending clothing wear. The present studies have been undertaken, for the first time, to measure length of wear and to assess the acceptance of such extended wear. Garments in these studies are commercially available exercise T-shirts and shorts, routine-wear T-shirts, and longsleeved pullover shirts. Fabric composition (cotton, polyester, light-weight, superfine Merino wool, modacrylic, cotton/rayon, polyester/Cocona, modacrylic/Xstatic, modacrylic/rayon, modacrylic/lyocell/aramid), construction (open knit, tight knit, open weave, tight weave), and finishing treatment (none, quaternary ammonium salt) are the independent variables. Eleven studies are reported here: five studies of exercise T-shirts, three of exercise shorts, two of routine wear Tshirts, and one of shirts used as sleep-wear. All studies are conducted in a climate-controlled environment, similar to a space vehicle's. For exercise clothing, study participants wear the garments during aerobic exercise. For routine wear clothing, study participants wear the T-shirts daily in an office or laboratory. Daily questionnaires collected data on ordinal preferences of nine sensory elements and on reason for retiring a used garment. Study 1 compares knitted cotton, polyester, and Merino exercise T-shirts (61 participants), study 2, knitted polyester, modacrylic, and polyester/Cocona exercise T-shirts (40 participants), study 3, cotton and polyester exercise shorts, knitted and woven (70 participants), all three using factorial experimental designs with and without a finishing treatment, conducted at the Johnson Space Center, sharing study participants. Study 4 compares knitted polyester and ZQ Merino exercise T

  18. Translation Studies: an overview

    Directory of Open Access Journals (Sweden)

    Cristina García de Toro

    2008-04-01

    Full Text Available The article briefly outlines the main schools and approaches that make up the current landscape of Translation Studies. The purpose of this paper is to offer an introduction to translation theory for those who are beginning their studies in this field or whose knowledge of Translation Studies is tangential. The article starts with a few preliminary matters, such as the question of what Translation Studies is and how the discipline has been mapped out. Then it moves on to examine the theoretical considerations that have been developed since the second half of the 20th century, with special attention being paid to the most recent decades. In this section, which is devoted to theoretical considerations, I will review some of the fundamental issues from a theories of equivalence and comparisons between languages; b functionalist theories; c discursive approaches; d polysystem theory, descriptive studies and norms; e cultural studies; f philosophical theories; g latest contributions to the field of Translation Studies; and h interdisciplinary and integrating approaches. Keywords: translation studies, contemporary theories, linguistic approaches, descriptive studies, cultural studies.

  19. New insights into mechanisms of small vessel disease stroke from genetics.

    Science.gov (United States)

    Tan, Rhea; Traylor, Matthew; Rutten-Jacobs, Loes; Markus, Hugh

    2017-04-01

    Cerebral small vessel disease (SVD) is a common cause of lacunar strokes, vascular cognitive impairment (VCI) and vascular dementia. SVD is thought to result in reduced cerebral blood flow, impaired cerebral autoregulation and increased blood-brain barrier (BBB) permeability. However, the molecular mechanisms underlying SVD are incompletely understood. Recent studies in monogenic forms of SVD, such as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), and 'sporadic' SVD have shed light on possible disease mechanisms in SVD. Proteomic and biochemical studies in post-mortem monogenic SVD patients, as well as in animal models of monogenic disease have suggested that disease pathways are shared between different types of monogenic disease, often involving the impairment of extracellular matrix (ECM) function. In addition, genetic studies in 'sporadic' SVD have also shown that the disease is highly heritable, particularly among young-onset stroke patients, and that common variants in monogenic disease genes may contribute to disease processes in some SVD subtypes. Genetic studies in sporadic lacunar stroke patients have also suggested distinct genetic mechanisms between subtypes of SVD. Genome-wide association studies (GWAS) have also shed light on other potential disease mechanisms that may be shared with other diseases involving the white matter, or with pathways implicated in monogenic disease. This review brings together recent data from studies in monogenic SVD and genetic studies in 'sporadic' SVD. It aims to show how these provide new insights into the pathogenesis of SVD, and highlights the possible convergence of disease mechanisms in monogenic and sporadic SVD. © 2017 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

  20. Safety Study in Aviation

    Directory of Open Access Journals (Sweden)

    Marek Štumper

    2016-07-01

    Full Text Available The objective of this article is to provide a brief look at safety studies, which are a necessary part of every change of system or a new system in aviation. The main focus is put on the area of air traffic management, because it affects most of the aviation stakeholders. The article begins with a description of safety and safety assessment of changes in systems. Then it discusses analysis of processes, hazard identification and risk assessment. Main part focuses on Safety studies and briefly describes the elements of the study. At the end, possible ways of safety study evaluation are mentioned.

  1. Studies on seismic waves

    Institute of Scientific and Technical Information of China (English)

    张海明; 陈晓非

    2003-01-01

    The development of seismic wave study in China in the past four years is reviewed. The discussion is divided into several aspects, including seismic wave propagation in laterally homogeneous media, laterally heterogeneous media, anisotropic and porous media, surface wave and seismic wave inversion, and seismic wave study in prospecting and logging problems. Important projects in the current studies on seismic wave is suggested as the development of high efficient numerical methods, and applying them to the studies of excitation and propagation of seismic waves in complex media and strong ground motion, which will form a foundation for refined earthquake hazard analysis and prediction.

  2. Information society studies

    CERN Document Server

    Duff, Alistair S

    2013-01-01

    We are often told that we are ""living in an information society"" or that we are ""information workers."" But what exactly do these claims mean, and how might they be verified? In this important methodological study, Alistair S. Duff cuts through the rhetoric to get to the bottom of the ""information society thesis."" Wide-ranging in coverage, this study will be of interest to scholars in information science, communication and media studies and social theory. It is a key text for the newly-unified specialism of information society studies, and an indispensable guide to the future of this disc

  3. Project management case studies

    CERN Document Server

    Kerzner, Harold R

    2013-01-01

    A new edition of the most popular book of project management case studies, expanded to include more than 100 cases plus a ""super case"" on the Iridium Project Case studies are an important part of project management education and training. This Fourth Edition of Harold Kerzner''s Project Management Case Studies features a number of new cases covering value measurement in project management. Also included is the well-received ""super case,"" which covers all aspects of project management and may be used as a capstone for a course. This new edition:Contains 100-plus case studies drawn from re

  4. Why Study in Australia?

    Institute of Scientific and Technical Information of China (English)

    丁丽丽

    2014-01-01

    Going overseas to pursue further studies is even more generalized in recent years. Students are open to a variety of op-tions to decide which country to go and which university to choose. Why wouldn’t you want to study with some of the best minds in the world? Australia is a leading global education power, with world’s best educators and facilities. It also provides both local and international students with a variety of quality study options. This essay presents some of the important reasons why in-ternational students should study in Australia in regard to education quality, affordable fees, government support, multiple cultures and immigration policies.

  5. Contemporary American Chinese Studies

    Institute of Scientific and Technical Information of China (English)

    Qiu Huafei

    2008-01-01

    The rise of modern American scholarship on China was largely attributed to the establishment of the American Joint Committee on Contemporary China (JCCC) in 1959 which sponsored all kinds of activities to promote Chinese studies, ranging from institutional support and financial resources to training courses. Since then, American study of China has entered into a period of sustainability that features academic and group-oriented research. It has become a mainstream discipline in American social science studies.1 There are some distinctive differences between early sinology and modern Chinese Studies: the latter is much more concentrated on the study of issues, comparative historical studies, and contemporary Chinese society. American Chinese studies stresses empirical research, textual data, and the application of theory to practice.Shanghai. He was a Fulbright visiting professor at State University of New York at Geneseo from 2006-2007. This treatise is one of a series of studies for China's National Research Foundation of Philosophy and Social Science (05BGJ012), "American Chinese Studies."

  6. Rainfall Climatology of the US Based on a Multifractal Storm Model

    Science.gov (United States)

    Lepore, C.; Molini, A.; Veneziano, D.; Yoon, S.

    2012-12-01

    Whether the multifractal properties of rainfall are impacted by climatology and therefore deviate from universality is a vexing question in both hydrology and the climate sciences and a crucial issue for rainfall downscaling applications. In a recent paper, Veneziano and Lepore (The Scaling of Temporal Rainfall, WRR, 2012) suggested a rainfall model with alternating storms and dry inter-storm periods and beta-lognormal multifractal rainfall intensity inside the storms. The parameters of the model are the rate of storm arrivals λ , the mean value mD and coefficient of variation VD of storm duration, the mean rainfall intensity inside the storms mI, and the multifractal parameters Cβ (lacunarity), CLN (intermittency), and dmax (outer limit of the scaling range). We use this model and 200 hourly rainfall records from NOAA to describe the variability of intense rainfall over the continental US. The records are selected based on length (at least 25 years) and data quality (quantization, fraction of unavailable values, periods when rainfall is reported as aggregated total depth…). We conclude that CLN and dmax display large systematic variations in space and with season. In particular, CLN decreases as latitude increases, from 0.20-0.25 along the Gulf of Mexico to about 0.12 in New England and 0.08 in the Northwest. This spatial variation is captured in approximation by partitioning the continental US into 11 climatic regions. Seasonal analysis shows that in most regions CLN is highest in the summer and lowest in the winter, following similar variations in the frequency and intensity of convective rainfall. An exception is the Northwest region, where CLN is almost constant throughout the year. The outer scale dmax is negatively correlated with CLN and follows opposite trends. The lacunarity parameter Cβ is lowest (around 0.04) in the Northeast and highest (around 0.07) in Florida and the Midwestern region. Lacunarity tends to be higher in the spring and summer

  7. Cross-cultural studies using a modified mini mental test for healthy subjects and patients with various forms of vascular dementia.

    Science.gov (United States)

    Thajeb, Peterus; Thajeb, Teguh; Dai, Daofu

    2007-03-01

    Existing neuropsychological tests are often complex and time-consuming. We designed a modified Mini Mental Test (MMT) battery for clinical assessment of the global and regional higher cortical functions of the brain. We tested its applicability in healthy subjects with different ethnic, cultural and educational backgrounds. The usefulness of our MMT as a tool for the clinical evaluation of patients with various forms of vascular dementia was determined. The MMT comprises five subtests, including clinical evaluations of: (A) orientation (6 points); (B) attention, right-left discrimination, speech, and calculation (20); (C) immediate recall, and recent and remote memory retrieval (10); (D) praxis (10); and (E) visuospatial orientation, agnosia, hemianopsia, and visual hemineglect (14). The MMT was administered to 100 healthy subjects from two different ethnic backgrounds (Indonesian and Chinese/Taiwanese) and diverse cultural and educational backgrounds, and to 61 patients with various forms of vascular dementia. MMT scores were significantly lower in healthy subjects with a low level of education regardless of their ethnic background (p<0.001). Patients with vascular dementia had much lower MMT scores than did the comparable age-adjusted normal controls (p<0.001). Of the patients with vascular dementia, those with Binswanger's disease had the lowest MMT scores (25.5+/-28.9), followed by those with large cerebral infarcts (48.0+/-7.1), cerebral haemorrhage (49.0+/-8.5), and multiple lacunar infarctions (55.0+/-0.5) (P<0.001). With a cut-off point of 33/55 (partial score/total score), the sensitivity and positive predictive value of the MMT were 0.98 and 0.94, respectively. The MMT is a simple and useful tool for clinical assessment of the cognitive functions of healthy subjects and patients with or without vascular dementia. It can be used for individuals with different ethnic, cultural and educational backgrounds.

  8. Agro-waste biosorbents: Effect of physico-chemical properties on atrazine and imidacloprid sorption.

    Science.gov (United States)

    Mandal, Abhishek; Singh, Neera; Nain, Lata

    2017-07-05

    Low cost agro-waste biosorbents namely eucalyptus bark (EB), corn cob (CC), bamboo chips (BC), rice straw (RS) and rice husk (RH) were characterized and used to study atrazine and imidacloprid sorption. Adsorption studies suggested that biosorbents greatly varied in their pesticide sorption behaviour. The EB was the best biosorbent to sorb both atrazine and imidacloprid with KF values of 169.9 and 85.71, respectively. The adsorption isotherm were nonlinear in nature with slope (1/n) values lacunarity and relative C-O band intensity parameters of biosorbents. Probably, both physisorption and electrostatic interactions were responsible for the pesticide sorption. The eucalyptus bark can be exploited as low cost adsorbent for the removal of these pesticides as well as a component of on-farm biopurification systems.

  9. Secondary Stroke Prevention in Cryptogenic Stroke and Embolic Stroke of Undetermined Source (ESUS).

    Science.gov (United States)

    Diener, Hans-Christoph; Bernstein, Richard; Hart, Robert

    2017-09-01

    The purpose of the study was to review the literature on cryptogenic stroke and embolic stroke of undetermined stroke (ESUS). Cryptogenic stroke according to TOAST criteria is a stroke which is not due to cardiogenic embolism, small vessel disease with lacunes or large vessel disease of brain supplying arteries. In the context of secondary stroke prevention studies, cryptogenic stroke is not operationally defined. The new concept of "embolic stroke of undetermined source" (ESUS) provides an operational definition. ESUS is diagnosed as a non-lacunar stroke on cerebral imaging and exclusion of large vessel atherosclerosis by CTA, MRA or ultrasound. Cardiogenic embolism is made less likely by ECG monitoring and echocardiography. At present, aspirin is used for secondary stroke prevention in patients with cryptogenic stroke. Based on the construct that ESUS might be caused by undetected atrial fibrillation or other embolic mechanisms, ongoing randomised secondary stroke prevention trials are comparing non-vitamin K oral anticoagulants (NOACs) with aspirin.

  10. [Epidemiology of stroke in Japan and comparison with the world].

    Science.gov (United States)

    Furuta, Yoshihiko; Ninomiya, Toshiharu

    2016-04-01

    Stroke was the leading cause of death in Japan until 1980s. The results from the Hisayama study, which is a population-based study in Japan, showed that incidence and mortality of stroke decreased with time owing to the improved management of hypertension. Although the incidence of hemorrhagic stroke decreased markedly, the proportion of hemorrhagic stroke among the incident cases of stroke in Japan is higher than in European countries. Among the incident cases of ischemic stroke, the proportion of lacunar infarction decreased significantly, whereas the proportion of atherothrombotic and cardioembolic stroke increased. These changes may be caused by elevating prevalence of metabolic disorders-namely, diabetes and hypercholesterolemia. Effective prevention and management of the metabolic disorder are necessary for further prevention of stroke.

  11. Intersection of the Sierpinski carpet with its rational translate

    Energy Technology Data Exchange (ETDEWEB)

    Dai Meifeng [Nonlinear Scientific Research Center, Faculty of Science, Jiangsu University, Zhenjiang, Jiangsu 212013 (China)]. E-mail: daimf@ujs.edu.cn; Tian Lixin [Nonlinear Scientific Research Center, Faculty of Science, Jiangsu University, Zhenjiang, Jiangsu 212013 (China)]. E-mail: tianlx@ujs.edu.cn

    2007-01-15

    Motivated by Mandelbrot's idea of referring to lacunarity of Cantor sets in terms of departure from translation invariance, Nekka and Li studied the properties of these translation sets and showed how they can be used for a classification purpose. In this paper, we pursue this study on the Sierpinski carpet with its rational translate. We also get the fractal structure of intersection I(x, y) of the Sierpinski carpet with its translate. We find that the packing measure of these sets forms a discrete spectrum whose non-zero values come only from shifting numbers with a finite triadic expansion. Concretely, when x and y have a finite triadic expansion, a very brief calculation formula of the measure is given.

  12. Some properties for the intersection of Moran sets with their translates

    Energy Technology Data Exchange (ETDEWEB)

    Dai Meifeng [Nonlinear Scientific Research Center, Faculty of Science, Jiangsu University, Zhenjiang 212013 (China)]. E-mail: daimf@ujs.edu.cn; Tian Lixin [Nonlinear Scientific Research Center, Faculty of Science, Jiangsu University, Zhenjiang 212013 (China)]. E-mail: tianlx@ujs.edu.cn

    2007-02-15

    Motivated by Mandelbrot's idea of referring to lacunarity of Cantor sets in terms of departure from translation invariance, Nekka and Li studied the properties of these translation sets and showed how they can be used for the classification purpose. In this paper, we pursue this study on a class of Moran sets with their rational translates. We also get the fractal structure of intersection I(x, y) of a class of Moran sets with their rational translates, and the formula of the box-counting dimension. We find that the Hausdorff measures of these sets form a discrete spectrum whose non-zero values come only from shifting vector with the expansion in fraction of (x, y). Concretely, when (x, y) has a finite expansion in fraction, a very brief calculation formula of the measure is given.

  13. Studies of Personality Disorders

    DEFF Research Database (Denmark)

    Ronningstam, Elsa; Simonsen, Erik; Oldham, John M

    2014-01-01

    The past 25 years have shown major advances in the studies of personality disorders. This collaborative article by the presidents, past and present, of ISSPD reflects on the progress within several significant areas of studies, i.e., assessment, neuroscience, treatment, prevention, advocacy...

  14. Study Groups in Denmark

    DEFF Research Database (Denmark)

    Hjorth, Poul G.

    2007-01-01

    Since 1998 European Study Groups have been held in Denmark, and Danish companies from LEGO and NOVO to very small high-tech firms have participated. I briefly describe the history, the organisation and the format of the Danish Study Groups, and highlight a few problem solutions....

  15. Prolactinomas : clinical studies

    NARCIS (Netherlands)

    Kars, Marleen

    2008-01-01

    Prolactinoma are treated with dopamine agonists, which are effective in reducing prolactin and tumor size. Studies reporting clinical and radiological outcome are scarce. The study described in chapter 2, assesses long-term outcome in patients treated with dopamine agonists for macroprolactinoma. An

  16. American Studies in Transition

    DEFF Research Database (Denmark)

    Nye, David

    Papers first given at a conference the previous year in Fåborg, Denmark, with a dual focus on 20th century America and new methods in American Studies.......Papers first given at a conference the previous year in Fåborg, Denmark, with a dual focus on 20th century America and new methods in American Studies....

  17. Pacific Studies: Quo Vadis?

    Directory of Open Access Journals (Sweden)

    Anne Holden Rønning

    2014-02-01

    Full Text Available Looking back to the past this paper discusses why Pacific studies and in particular Australasian studies became an area of interest in tertiary education in Europe. What subject areas initiated these studies, and how do past legacies shape the present? With cutbacks in higher education over the past two decades the future of interdisciplinary studies and the humanities looks bleak. At the same time due to global business and increased political communication across borders there is a vibrant interest in and need for such studies among businesses and students. For most Europeans the literature of settler countries, with their European legacy, makes access to ways of thought and culture easier than studies of countries with other mythological backgrounds. In today’s multicultural environment such studies can provide knowledge for an understanding of other cultures and increase tolerance of the ‘other’. Area studies have relevance to our situation in Europe with increased migrancy, not least as a result of Schengen and EU regulations.

  18. Simulation in International Studies

    Science.gov (United States)

    Boyer, Mark A.

    2011-01-01

    Social scientists have long worked to replicate real-world phenomena in their research and teaching environments. Unlike our biophysical science colleagues, we are faced with an area of study that is not governed by the laws of physics and other more predictable relationships. As a result, social scientists, and international studies scholars more…

  19. Prolactinomas : clinical studies

    NARCIS (Netherlands)

    Kars, Marleen

    2008-01-01

    Prolactinoma are treated with dopamine agonists, which are effective in reducing prolactin and tumor size. Studies reporting clinical and radiological outcome are scarce. The study described in chapter 2, assesses long-term outcome in patients treated with dopamine agonists for macroprolactinoma. An

  20. MY ENGLISH STUDY

    Institute of Scientific and Technical Information of China (English)

    孙岩; Roxanne; Lees

    2003-01-01

    I am a student of Yanshan University, majoring in English. I have studied English for a long time, which is full of (and have encountered some) special experiences (in my studies). After graduation from (a) junior (middle) school, I did not go to senior (middle) school for

  1. Asterisk Grade Study Report.

    Science.gov (United States)

    Kokorsky, Eileen A.

    A study was conducted at Passaic County Community College (PCCC) to investigate the operation of a grading system which utilized an asterisk (*) grade to indicate progress in a course until a letter grade was assigned. The study sought to determine the persistence of students receiving the "*" grade, the incidence of cases of students receiving…

  2. Designing satisfaction studies

    DEFF Research Database (Denmark)

    Kristensen, Kai; Eskildsen, Jacob Kjær

    2007-01-01

    In the effect sampling method, presentation of researcher, the intro text, the order of questions in the questionnaire along with the number of categories in the rating scale is tested in relation to the design of satisfaction studies. Based on the analyses specific recommendations for designing...... satisfaction studies are given....

  3. Get Oriented: Study Japan.

    Science.gov (United States)

    Parramore, Barbara M.

    1981-01-01

    Recommends that students in social studies classes be exposed to a study of Japan because of the wide array of contrasts possible between Japan and the United States. Information is presented on Japan's modernization, global status, language, decision-making processes, and ancient traditions. (DB)

  4. Single Policy Study

    DEFF Research Database (Denmark)

    Kronsell, Annica; Manners, Ian James

    2015-01-01

    the relevance of single policy studies in EU research and give examples of how such research can be designed and carried out. The chapter reviews three examples of single policy studies using different methods based on EU environmental policy, the EU biofuels directive, and the EU Common Security and Defence...... Policy (CSDP). The examples are illustrative of how single policy studies can be designed to use different approaches in the analysis: multiple streams approach to policy-making; a comparative hypothesis testing; and feminist institutional theory.......Single policy studies are the most common form of European Union (EU) research. Single policy studies are widely used to understand the role of the EU in a wide variety of sectors, together with their development over time, and often offer public policy prescriptions. This chapter discusses...

  5. Critical Digital Tourism Studies

    DEFF Research Database (Denmark)

    Gyimóthy, Szilvia; Munar, Ana María

    2013-01-01

    ) are approached mostly from a business administration perspective and informed by conceptual frameworks developed in management and marketing. IT studies in tourism are still at a stage similar to the first advocacy phase of tourism research in general (Jafari, 1990) and are seldom inspired by relevant......This paper advocates the need for a critical and cross-disciplinary research agenda on the field of digital technologies and tourism. The changing virtual landscape of tourism has received increased attention by tourism scholars. However, contemporary studies on information technologies (IT...... to studying digital socio-technical systems and virtual mediation in tourism. Critical Digital Tourism Studies opens a new cross-disciplinary field where the sociality of virtual tourism interactions is examined (entailing the study of structures, social rules, ideologies, power relations, sustainability...

  6. Entrepreneurship and Process Studies

    DEFF Research Database (Denmark)

    Hjorth, Daniel; Holt, Robin; Steyaert, Chris

    2015-01-01

    Process studies put movement, change and flow first; to study processually is to consider the world as restless, something underway, becoming and perishing, without end. To understand firms processually is to accept but also – and this is harder perhaps – to absorb this fluidity, to treat...... a variable as just that, a variable. The resonance with entrepreneurship studies is obvious. If any field is alive to, and fully resonant with, a processual understanding of, for example, the creation of firms, it is entrepreneurship studies. This special issue is an attempt to consider the promise...... and potential of processual approaches to studying, researching and practising entrepreneurship. The articles in the issue attest to an increasing sensitivity to processual thinking. We argue that appreciating entrepreneurial phenomena processually opens up the field to an understanding of entrepreneurship...

  7. Critical Digital Tourism Studies

    DEFF Research Database (Denmark)

    Gyimóthy, Szilvia; Munar, Ana María

    2013-01-01

    ) are approached mostly from a business administration perspective and informed by conceptual frameworks developed in management and marketing. IT studies in tourism are still at a stage similar to the first advocacy phase of tourism research in general (Jafari, 1990) and are seldom inspired by relevant......This paper advocates the need for a critical and cross-disciplinary research agenda on the field of digital technologies and tourism. The changing virtual landscape of tourism has received increased attention by tourism scholars. However, contemporary studies on information technologies (IT...... to studying digital socio-technical systems and virtual mediation in tourism. Critical Digital Tourism Studies opens a new cross-disciplinary field where the sociality of virtual tourism interactions is examined (entailing the study of structures, social rules, ideologies, power relations, sustainability...

  8. Electromagnetic induction studies

    Science.gov (United States)

    Hermance, J. F.

    1983-04-01

    Recent developments in electromagnetic induction studies of the lithosphere and the asthenosphere are reviewed. Attention is given to geoelectrical studies of active tectonic areas in terms of the major zones of crustal extension, the basin and range province along western regions of North America, and the Rio Grande rift. Studies have also been performed of tectonic activity around Iceland, the Salton Trough and Cerro Prieto, and the subduction zones of the Cascade Mountains volcanic belt, where magnetotelluric and geomagnetic variation studies have been done. Geomagnetic variations experiments have been reported in the Central Appalachians, and submarine electromagnetic studies along the Juan de Fuca ridge. Controlled source electromagnetic and dc resistivity investigations have been carried out in Nevada, Hawaii, and in the Adirondacks Mountains. Laboratory examinations on the conductivity of representative materials over a broad range of temperature, pressure, and chemistry are described.

  9. Evaluating mandibular cortical index quantitatively.

    Science.gov (United States)

    Yasar, Fusun; Akgunlu, Faruk

    2008-10-01

    The aim was to assess whether Fractal Dimension and Lacunarity analysis can discriminate patients having different mandibular cortical shape. Panoramic radiographs of 52 patients were evaluated for mandibular cortical index. Weighted Kappa between the observations were varying between 0.718-0.805. These radiographs were scanned and converted to binary images. Fractal Dimension and Lacunarity were calculated from the regions where best represents the cortical morphology. It was found that there were statistically significant difference between the Fractal Dimension and Lacunarity of radiographs which were classified as having Cl 1 and Cl 2 (Fractal Dimension P:0.000; Lacunarity P:0.003); and Cl 1 and Cl 3 cortical morphology (Fractal Dimension P:0.008; Lacunarity P:0.001); but there was no statistically significant difference between Fractal Dimension and Lacunarity of radiographs which were classified as having Cl 2 and Cl 3 cortical morphology (Fractal Dimension P:1.000; Lacunarity P:0.758). FD and L can differentiate Cl 1 mandibular cortical shape from both Cl 2 and Cl 3 mandibular cortical shape but cannot differentiate Cl 2 from Cl 3 mandibular cortical shape on panoramic radiographs.

  10. Neuroimaging of young adults with stroke in Ilorin Nigeria.

    Science.gov (United States)

    Oyinloye, Olalekan; Nzeh, Donald; Adesiyun, Olusola; Ibrahim, Mohammed; Akande, Halimat; Sanya, Emmanuel

    2015-01-01

    Stroke in young adults is relatively uncommon. Computed tomography (CT) and magnetic resonance imaging (MRI) are the most valuable tools for the diagnosis of stroke. Recent data on stroke in young adults in Nigeria is sparse. The aim of this study is to document the imaging pattern in young patients aged 15-45 years with suspected cerebrovascular accidents (CVA) in the Nigerian environment. This was a retrospective study of 69 patients aged 15-45 years, with clinical diagnosis of stroke, referred for neuro-imaging, from October 2008 to November 2013. All patients with the clinical diagnosis of stroke within this age group were recruited into the study. Images were obtained from a four slice channel general electric CT machine and a 0.2 Tesla Siemens Magnetom Concerto MRI scanner. A total of 69 patients (44 males and 25 females) were studied. Sixty out of 69 (87.0%) patients were accurately diagnosed with CVA, with 9 (13.0) cases of misdiagnoses. A total of 21 (35%) out of the 60 cases confirmed on imaging had intracerebral hemorrhage (ICH), 10 (16.7%) had subarachnoid hemorrhage (SAH) and 29 (48.3%) had cerebral infarct (CI). Hypertension was the common risk factor for all stroke subtypes. The most common location for ICH, was the basal ganglia in 8 (38.8%), while the commonest pattern for CI, was lacunar infarct in the basal ganglia (51.7%). The incidence of hemorrhagic CVA (ICH and SAH combined) was slightly higher than ischemic CVA in this study. Lacunar infarcts in the basal ganglia and also ICH in the basal ganglia were the most common patterns, both are strongly linked to hypertension. A diagnostic protocol of stroke in young adults, to include neuroimaging and other ancillary investigations is advocated for stroke in young adults as some of the etiologies are treatable.

  11. The study of early recurrence factors of cerebral watershed infarction%分水岭脑梗死患者复发的危险因素分析

    Institute of Scientific and Technical Information of China (English)

    殷萍; 魏亚芬

    2013-01-01

    目的 分析分水岭脑梗死(WSI)的临床特点,探讨引起WSI早期复发的危险因素.方法 选取2010年1月至2012年12月黑龙江省医院神经内科收治的前循环脑梗死患者283例,收集所有患者年龄、性别、卒中危险因素及血管狭窄程度,283例患者包括腔隙性脑梗死组83例、大面积脑梗死组60例、WSI组140例.随访半年,观察各组患者复发情况.收集WSI患者复发前后美国国立卫生研究院卒中量表(NIHSS)评分并进行比较.比较复发与未复发组WSI患者各项卒中危险因素有无差异.结果 (1) WSI组、大面积脑梗死组、腔隙性脑梗死组患者半年复发率分别为40.0%(56/140)、30.0%(18/60)、9.6%(8/83),复发率与腔隙性脑梗死组比较差异均有统计学意义(x2=23.5、x2=9.7,P均<0.01),以WSI组复发率最高.(2)WSI患者初次卒中后临床症状相对较轻,NIHSS评分0~4分者为75.7%(106/140),5~9分为22.9% (32/140),≥10分患者仅为1.4%(2/140).复发WSI患者临床症状较前明显加重,其中NIHSS评分≥10分患者比例为28.6%(16/56).(3)WSI患者复发组与未复发组各危险因素比较,不稳定斑块、基线收缩压、狭窄程度≥70%方面差异有统计学意义(P均<0.05).结论 WSI较其他类型脑梗死更易复发.WSI首次发病一般症状较轻,但复发后临床症状重、预后差.不稳定斑块、基线收缩压、狭窄程度≥70%是脑梗死复发的独立危险因素.%Objective To investigate clinical features and the early recurrence factors of watershed infarction(WSI).Methods Two hundred and eighty-three patients with acute anterior circulation vascular infraction confirmed by CT or MRI were collected in Heilongjiang Province Hospital from January 2010 to December 2012.Patients' information including gender,sex,risk factors for stroke and vascular stenosis was colleced.Patients were divided into the lacunar infarction group (n =83),large infarction group(n =60) and the WSI

  12. Effective Physics Study Habits

    Science.gov (United States)

    Zettili, Nouredine

    2011-04-01

    We discuss the methods of efficient study habits and how they can be used by students to help them improve learning physics. In particular, we deal with ideas pertaining to the most effective techniques needed to help students improve their physics study skills. These ideas were developed as part of Project IMPACTSEED (IMproving Physics And Chemistry Teaching in SEcondary Education), an outreach grant funded by the Alabama Commission on Higher Education. This project is motivated by a major pressing local need: A large number of high school physics teachers teach out of field. In the presentation, focus on topics such as the skills of how to develop long term memory, how to improve concentration power, how to take class notes, how to prepare for and take exams, how to study scientific subjects such as physics. We argue that the student who conscientiously uses the methods of efficient study habits will be able to achieve higher results than the student who does not; moreover, a student equipped with the proper study skills will spend much less time to learn a subject than a student who has no good study habits. The underlying issue here is not the quantity of time allocated to the study efforts by the student, but the efficiency and quality of actions. This work is supported by the Alabama Commission on Higher Education as part of IMPACTSEED grant.

  13. China's India Studies

    Institute of Scientific and Technical Information of China (English)

    Liu Qian

    2008-01-01

    Over the past 50 years, with the improvement of relationship between India and China, the scope of India studies in China's IR research has been broadened and the new areas of studies are being explored. The research agenda of India studies has already extended to the areas like economy, society, culture, security, national strategy and their impact on both bilateral and international relations. In this situation, the focuses of India studies in China's IR research can be mainly identified as follows: reviews on India's social, political and economic systems; analysis on the national strategy and foreign policy; Sino-Indian relations; India's relations with some international organizations. However, even though many fresh progresses have been made in India studies, the India studies in China's IR research still lag far behind the study of other important countries like the U.S., UK, Russia and Japan, and more problems and challenges will face in the coming future. The paper believes that a fuller understanding of India probably will not make China and India close friends, but it definitely will help to prevent them from becoming fierce enemies.

  14. [International cohort studies].

    Science.gov (United States)

    Ahrens, W; Pigeot, I

    2012-06-01

    Among observational studies, cohort studies, i.e. longitudinal observations of selected population groups, provide the highest possible evidence of a causal association between specific risk factors (exposure) and the occurrence of disease in populations. Besides the fact that many exposures cannot be investigated in experimental designs, cohort studies have the advantage over randomized clinical trials that they are conducted in free living populations and not in restrictive, clinical settings. In this paper we describe the aims and features of international cohorts that have been selected because of their impact, their size or their endpoints. We do not only present the study designs and survey instruments used but we also highlight some of the most important results gained by these studies. Most of these prospective studies investigated common chronic diseases in the elderly, such as cancer, diabetes, cardiovascular or neurodegenerative diseases, osteoporosis and ophthalmologic disorders. Newer cohorts and recent reassessments of existing cohorts almost always include the collection and storage of biological samples. In recent years technological developments allowed the implementation of cutting edge measurement procedures, such as imaging techniques for phenotyping. Finally, we discuss on the one hand whether these designs can be transferred to the German situation and on the other hand to what degree the results obtained from foreign cohorts can be generalized for the German population. We conclude with recommendations for future cohort studies.

  15. Single Policy Study

    DEFF Research Database (Denmark)

    Kronsell, Annica; Manners, Ian James

    2015-01-01

    Single policy studies are the most common form of European Union (EU) research. Single policy studies are widely used to understand the role of the EU in a wide variety of sectors, together with their development over time, and often offer public policy prescriptions. This chapter discusses the r...... Policy (CSDP). The examples are illustrative of how single policy studies can be designed to use different approaches in the analysis: multiple streams approach to policy-making; a comparative hypothesis testing; and feminist institutional theory.......Single policy studies are the most common form of European Union (EU) research. Single policy studies are widely used to understand the role of the EU in a wide variety of sectors, together with their development over time, and often offer public policy prescriptions. This chapter discusses...... the relevance of single policy studies in EU research and give examples of how such research can be designed and carried out. The chapter reviews three examples of single policy studies using different methods based on EU environmental policy, the EU biofuels directive, and the EU Common Security and Defence...

  16. American Studies in Romania

    Directory of Open Access Journals (Sweden)

    Ioana Luca

    2006-01-01

    Full Text Available American Studies at the University of BucharestThe idea of teaching American Studies and founding a program in American Studies was first voiced in the long meetings of faculty and students held at the University of Bucharest soon after the collapse of the communist regime. The proposal was one of many that reflected the spirit of reform and hope for radical changes at the outset of Romania’s transition to democracy. The absence of institutional structures other than English departments and t...

  17. Lead Time Study,

    Science.gov (United States)

    1982-05-01

    AD-A128 318 LEAD TIME STUDY (U) ARMY ARMAMENT RESEARCH AND DEVELOPMENT CDMMAND DOVER NJ SYSTEMS ANALYSIS DIV dI-T~~ CHU MAY 82 ARRAA 82- 3/ /l N...EhhEEE--E 1111.0 U 1 - I 1120 1.25I1,,-. 11.6 MICROCOPY RESOLUTION TESI CHARI NATIONAL BUREAU 01 STANDARDt 19t,3 A co LEAD TIME STUDY c*A JULIE CHU MAY...188 D I.-f . . .... .. - r - .. " ’- -~ L - - _ _ __ ARRAA 82-3 LEAD TIME STUDY Prepared by:_ JL CHU Reviewed by:Li t’ ( LAWRENCE J. QWUNI Chief, Sys

  18. Border region studies

    DEFF Research Database (Denmark)

    Makkonen, Teemu; Williams, Allan

    2016-01-01

    The contemporary conditions of academic capitalism exert pressures on researchers to avoid ‘peripheral’ journals and ‘unfashionable’ topics. Here an attempt is made to shed light onto the structure of one such ‘offbeat’ field, namely ‘border region studies’, by discussing its geographical...... distribution, key themes, significance and impact. The review suggests that border region studies can be considered a significant and important ‘branch’ of regional studies, which accounts for a small but increasing proportion of regional studies research particularly in Europe and North America. Four main...

  19. Studying Voltage Transformer Ferroresonance

    Directory of Open Access Journals (Sweden)

    Hamid Radmanesh

    2012-09-01

    Full Text Available This study studies the effect of Circuit Breaker Shunt Resistance (CBSR, Metal Oxide Vaistor (MOV and Neutral earth Resistance (NR on the control of ferroresonance in the voltage transformer. It is expected that NR can controlled ferroresonance better than MOV and CBSR. Study has been done on a one phase voltage transformer rated 100 VA, 275 kV. The simulation results reveal that considering the CBSR and MOV exhibits a great mitigating effect on ferroresonance overvoltages, but these resistances cannot control these phenomena for all range of parameters. By applying NR to the system structure, ferroresonance has been controlled and its amplitude has been damped for all parameters values.

  20. Building Transdisciplinary Environmental Studies

    DEFF Research Database (Denmark)

    Holm, Jesper

    We will in this paper approach the challenge of building integrated environmental studies by presenting a crude frame of analysis which take into account both the physical aspects and the social-discursive articulations of environmental problems. This framework partly mirrors the approach of our...... department (Dept. of Environment, Technology and Social Studies, Roskilde University), and has originally in another version been presented in the book “Miljøregulering - tværvidenskabelige studier (Environmental Regulation. Interdisciplinary Studies)” (Holm, Kjærgård & Pedersen eds. 1997, in Danish) written...

  1. Reproducibility of 2D and 3D fractal analysis techniques for the assessment of spatial heterogeneity of regional blood flow in rectal cancer.

    Science.gov (United States)

    Sanghera, Bal; Banerjee, Debasish; Khan, Aftab; Simcock, Ian; Stirling, J James; Glynne-Jones, Rob; Goh, Vicky

    2012-06-01

    To characterize the two-dimensional (2D) and three-dimensional (3D) fractal properties of rectal cancer regional blood flow assessed by using volumetric helical perfusion computed tomography (CT) and to determine its reproducibility. Institutional review board approval and informed consent were obtained. Ten prospective patients (eight men, two women; mean age, 72.3 years) with rectal adenocarcinoma underwent two repeated volumetric helical perfusion CT studies (four-dimensional adaptive spiral mode, 11.4-cm z-axis coverage) without intervening treatment within 24 hours, with regional blood flow derived by using deconvolution analysis. Two-dimensional and 3D fractal analyses of the rectal tumor were performed, after segmentation from surrounding structures by using thresholding, to derive fractal dimension and fractal abundance. Reproducibility was quantitatively assessed by using Bland-Altman statistics. Two-dimensional and 3D lacunarity plots were also generated, allowing qualitative assessment of reproducibility. Statistical significance was at 5%. Mean blood flow was 63.50 mL/min/100 mL ± 8.95 (standard deviation). Good agreement was noted between the repeated studies for fractal dimension; mean difference was -0.024 (95% limits of agreement: -0.212, 0.372) for 2D fractal analysis and -0.024 (95% limits of agreement: -0.307, 0.355) for 3D fractal analysis. Mean difference for fractal abundance was -0.355 (95% limits of agreement: -0.869, 1.579) for 2D fractal analysis and -0.043 (95% limits of agreement: -1.154, 1.239) for 3D fractal analysis. The 95% limits of agreement were narrower for 3D than 2D analysis. Lacunarity plots also visually confirmed close agreement between repeat studies. Regional blood flow in rectal cancer exhibits fractal properties. Good reproducibility was achieved between repeated studies with 2D and 3D fractal analysis.

  2. Nodular sclerosis classical Hodgkin lymphoma grade 2: A diagnostic challenge to the cytopathologists.

    Science.gov (United States)

    Sharma, Sudha; Dey, Pranab; Mitra, Suvradeep; Rajwanshi, Arvind; Nijhawan, Raje; Srinivasan, Radhika; Gupta, Nalini; Das, Ashim

    2017-02-01

    Grade 2 nodular sclerosis classical Hodgkin lymphoma (NSCHL) is less common than grade 1 lymphoma and has a worse overall prognosis. To the best of the authors' knowledge, no study of a large series of cases has been performed until now. The objective of this study was to assess the diagnostic efficacy of cytology for grade 2 NSCHL versus grade 1 NSCHL and study the morphological features of grade 2 NSCHL in fine-needle aspiration cytology (FNAC). Fifteen of 51 histopathology-proven cases of NSCHL (18 FNAC procedures) were grade 2, and 36 were grade 1. The efficacy of FNAC for detecting grade 1 and 2 NSCHL was assessed, and the frequency of misdiagnosis was compared. The clinical details and cytomorphological features of grade 2 NSCHL were studied in detail. Among the grade 1 NSCHL patients, 58.4% were diagnosed with Hodgkin lymphoma (HL) or had findings suggestive of HL, whereas 20% of the grade 2 patients were diagnosed HL or suggestive of HL. Two cases of grade 2 NSCHL were misdiagnosed as anaplastic large cell lymphoma, and 4 were misdiagnosed as malignant neoplasms. Grade 2 NSCHL cases showed clusters and sheets of mononuclear, multinucleated, and bizarre cells, with some cases showing a suppurative background. However, extensive searching showed occasional Reed-Sternberg (RS) cells in most of the cases, and lacunar cells were seen in 12 cases. The diagnostic efficacy of FNAC is much lower for grade 2 NSCHL versus grade 1 NSCHL. The search for an occasional RS cell and the identification of lacunar cells can provide a clue for the diagnosis. Cancer Cytopathol 2017;125:104-113. © 2016 American Cancer Society. © 2016 American Cancer Society.

  3. Pavement Subgrade Performance Study

    DEFF Research Database (Denmark)

    Zhang, Wei; Ullidtz, Per; Macdonald, Robin

    1998-01-01

    The report describes the second test in the Danish Road Testing Machine (RTM) under the International Pavement Subgrade Performance Study. Pavement response was measured in different layers, and compared to different theroretical values. Performance in terms of plastic strains, rutting...

  4. Upper Kenai Corridor Study

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Upper Kenai Corridor study describes and evaluates the Upper Kenai River and the land which embraces it. It also places the river corridor in its regional...

  5. Esophagram (Barium Swallow Study)

    Science.gov (United States)

    ... Test Performing Spirometry Test Pressure Volume Study Routine Test Spirometry Testing ... © 2017 National Jewish Health 1400 Jackson Street Denver, Colorado 80206 1.877.225.5654 Policies & Guidelines | ...

  6. Tailored Barium Swallow Study

    Science.gov (United States)

    ... Test Performing Spirometry Test Pressure Volume Study Routine Test Spirometry Testing ... © 2017 National Jewish Health 1400 Jackson Street Denver, Colorado 80206 1.877.225.5654 Policies & Guidelines | ...

  7. Epidemiological studies on syncope

    DEFF Research Database (Denmark)

    Ruwald, Martin Huth

    2013-01-01

    of the patients play an essential role. In epidemiology these factors have major impact on the outcome of the patients. Until recently, even the definition of syncope differed from one study to another which has made literature reviews difficult. Traditionally the data on epidemiology of syncope has been taken...... from smaller studies from different clinical settings with wide differences in patient morbidity. Through the extensive Danish registries we examined the characteristics and prognosis of the patients hospitalized due to syncope in a nationwide study. The aims of the present thesis were to investigate......, prevalence and cardiovascular factors associated with the risk of syncope, 4) the prognosis in healthy individuals discharged after syncope, and 5) the prognosis of patients after syncope and evaluation of the CHADS2 score as a tool for short- and long-term risk prediction. The first studies of the present...

  8. PPB | Study Team

    Science.gov (United States)

    The Pleuropulmonary Blastoma (PPB) DICER1 Syndrome Study team is made up of researchers from the National Cancer Institute, Children¹s National Medical Center, the International Pleuropulmonary Blastoma Registry, and Washington University in St. Louis.

  9. Chamberino Floodplain Management Study

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The Dona Ana County Flood Commission requested the United States Department of Agriculture's Natural Resources Conservation Service to conduct a study of the...

  10. Marketing study: sealskin products

    National Research Council Canada - National Science Library

    1985-01-01

    This is a draft report prepared for the Canadian Sealers Association incorporating findings of a three phase study conducted to determine the potential for the Newfoundland and Labrador sealskin craft industry...

  11. Learn about Clinical Studies

    Science.gov (United States)

    ... is to make sure that the study is ethical and that the rights and welfare of participants ... trials provide the basis for the development and marketing of new drugs, biological products, and medical devices. ...

  12. The Study of Matter.

    Science.gov (United States)

    Campbell, Peter

    2000-01-01

    Reviews the booklet "The Study of Matter" produced by the Institute of Physics as part of their Shaping the Future series. This booklet is designed for teachers of chemistry, physics, design and technology, and biology. (Author/CCM)

  13. Dismal Swamp Study

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A study of Union Camp properties in Dismal Swamp to evaluate the effects of a proposed commercial farming project involving approximately 32,000 acres lying north of...

  14. Schoolground Soil Studies.

    Science.gov (United States)

    Doyle, Charles

    1978-01-01

    Outlined are simple activities for studying soil, which can be conducted in the schoolyard. Concepts include soil profiles, topsoil, soil sizes, making soil, erosion, slope, and water absorption. (SJL)

  15. Esophagram (Barium Swallow Study)

    Science.gov (United States)

    ... Allergy Prick Skin Testing Cardiac Tests Ambulatory Blood Pressure Monitoring Cardiac Catheterization Cardiac MRI Cardiac Stress Test Using ... Test Exercise-Induced Bronchoconstriction (EIB) Gas Exchange Tests Arterial Blood ... Washout Performing Pressure Volume Study Performing Routine ...

  16. Tailored Barium Swallow Study

    Science.gov (United States)

    ... Allergy Prick Skin Testing Cardiac Tests Ambulatory Blood Pressure Monitoring Cardiac Catheterization Cardiac MRI Cardiac Stress Test Using ... Test Exercise-Induced Bronchoconstriction (EIB) Gas Exchange Tests Arterial Blood ... Washout Performing Pressure Volume Study Performing Routine ...

  17. Willow ptarmigan study

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Willow ptarmigan (Lagopus lagopus; see Appendix I for scientific names of birds observed during this study) are a species of management interest because they are...

  18. Comparative Packaging Study

    Science.gov (United States)

    Perchonok, Michele; Antonini, David

    2008-01-01

    This viewgraph presentation describes a comparative packaging study for use on long duration space missions. The topics include: 1) Purpose; 2) Deliverables; 3) Food Sample Selection; 4) Experimental Design Matrix; 5) Permeation Rate Comparison; and 6) Packaging Material Information.

  19. Nature Study Tips. Spiders.

    Science.gov (United States)

    Mulaik, Stanley B.

    1990-01-01

    Different types of spiders, their ranges and habits are discussed. Activities associated with the study of spiders are suggested. Four references are listed which may be of interest to beginners. (CW)

  20. Exploratory studies, 1988

    Energy Technology Data Exchange (ETDEWEB)

    1989-05-01

    This report discusses the following topics: accelerator physics for the ALS; SSC support; machine investigations; mathematical techniques in particle dynamics; APIARY: B-factory studies; and two-beam accelerators and bright electron sources.

  1. PET studies in epilepsy

    OpenAIRE

    Sarikaya, Ismet

    2015-01-01

    Various PET studies, such as measurements of glucose, serotonin and oxygen metabolism, cerebral blood flow and receptor bindings are availabe for epilepsy. 18Fluoro-2-deoxyglucose (18F-FDG) PET imaging of brain glucose metabolism is a well established and widely available technique. Studies have demonstrated that the sensitivity of interictal FDG-PET is higher than interictal SPECT and similar to ictal SPECT for the lateralization and localization of epileptogenic foci in presurgical patients...

  2. CHAROITE. EXPERIMENTAL STUDIES

    OpenAIRE

    MARCHUK MARINA V.; MEDVEDEV VLADIMIR YA.; IVANOVA LARISA A.; SOKOLOVA TATYANA S.; DANILOV BORIS S.; GLADKOCHUB DMITRY P.

    2016-01-01

    The article provides an overview of experimental studies of charoite and charoite-containing rock formation hypotheses. The authors conducted experiments to clarify charoite and host rocks interaction and study charoite transformation processes at high temperatures. A series of experiments was aimed at improving the substandard charoite samples. The experiments show the formation of polymineral reaction zones due to the contact interaction between charoite and microcline-arfvedsonite lamproph...

  3. Pregnancy: a demographic study

    OpenAIRE

    Laufer, Linda

    1987-01-01

    A retrospective study of 126 pregnant females, presenting to a chiropractor’s office was made. The average age of the patient was 29.8 years. Their backgrounds were career oriented and for the majority, it was their first pregnancy. The most frequent complaint was lower back pain. The study outlines the necessity for further data on the role of the chiropractic management of the pregnant patient.

  4. Study on Military Professionalism

    Science.gov (United States)

    1970-06-30

    Education Study. Washington: July 1966. 88. United States vs Yamashita, Action of Confirming Authority. I 7 February 1946. 89. Vroom , Victor H . Work and...I’ H N. PART II -METHODOLOGY A. MISSION. The mission assigned for this study was to assess the existing climate of professionalism in today’s Army...factors to such a degree that they were truly consequential in this assessment of the H professional climate. One can draw this conclusion from three

  5. Tanzania country study

    Energy Technology Data Exchange (ETDEWEB)

    Meena, H.E. [Centre for Energy, Environment, Science and Technology, Dar es Salaam (Tanzania, United Republic of)

    1998-10-01

    An objective of this study is to analyse the role of the land use sectors of Tanzania (especially forestry) on mitigation of greenhouse gases. Specific emphasis is placed on the relationship between forestry and energy supply from biomass. This is a follow up study on an earlier effort which worked on mitigation options in the country without an in-depth analysis of the forestry and land use sectors. (au)

  6. Workshop I: Gender Studies

    Science.gov (United States)

    Hennessey, Eden; Kurup, Anitha; Meza-Montes, Lilia; Shastri, Prajval; Ghose, Shohini

    2015-12-01

    Participants in the Gender Studies workshop of the 5th IUPAP International Conference on Women in Physics discussed the gender question in science practice from a policy perspective, informed by investigations from the social science disciplines. The workshop's three sessions—"Equity and Education: Examining Gender Stigma in Science," "A Comparative Study of Women Scientists and Engineers: Experiences in India and the US," and "Toward Gender Equity Through Policy: Characterizing the Social Impact of Interventions—are summarized, and the resulting recommendations presented.

  7. Zambia country study

    Energy Technology Data Exchange (ETDEWEB)

    1999-09-01

    The Zambia Country Study, which was part of the Danida-funded project Climate Change Mitigation in Southern Africa: Phase 2, aimed at methodological development, national mitigation analysis and institutional capacity building in Zambia. The study comprised the following five elements: Comprehensive evaluation of national social and economic development framework for climate change; Baseline scenario(s) projection(s); Mitigation scenario(s) projection(s); Macro-economic assessment; Implementation Issues. (au) 17 refs.

  8. Future ATLAS Higgs Studies

    CERN Document Server

    Smart, Ben; The ATLAS collaboration

    2017-01-01

    The High-Luminosity LHC will prove a challenging environment to work in, with for example $=200$ expected. It will however also provide great opportunities for advancing studies of the Higgs boson. The ATLAS detector will be upgraded, and Higgs prospects analyses have been performed to assess the reach of ATLAS Higgs studies in the HL-LHC era. These analyses are presented, as are Run-2 ATLAS di-Higgs analyses for comparison.

  9. Blast Overpressure Studies.

    Science.gov (United States)

    1998-05-01

    USAARL Contract Report No. CR-98-Ö3 Blast Overpressure Studies By Daniel L. Johnson EG&G Management Systems, Inc. Albuquerque, New Mexico May...Both studies were done at the Blast Overpressure-Kirtland Test Site (BOP-KTS) in New Mexico . Under a contract conducted for the USAMRMC, EG&G was... TDH -4 9 elements mounted in a David Clark 9AN/2 ear muff for added noise isolation. The calibration of the earphones was accomplished using a Bruel

  10. Colombian cracker feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-06

    Colombia`s Promotora de Olefinas Aromaticos del Caribe will soon select a consulting group to develop a $500,000 feasibility study for an olefins plant at Mamonal, Cartagena. The project will involve investments of $1.2 billion and will be based on natural gas from the Cusiana field, being developed by Ecopetrol and BP. Several groups are competing for the study; SRI International, Japan Consulting Institute, Muse, Stancil, Chem Systems, and KBC Advanced Technologies.

  11. [Qualitative case study].

    Science.gov (United States)

    Debout, Christophe

    2016-06-01

    The qualitative case study is a research method which enables a complex phenomenon to be explored through the identification of different factors interacting with each other. The case observed is a real situation. In the field of nursing science, it may be a clinical decision-making process. The study thereby enables the patient or health professional experience to be conceptualised. Copyright © 2016. Published by Elsevier Masson SAS.

  12. Marine Resiliency Study II

    Science.gov (United States)

    2016-07-06

    1S. SUBJECT TERMS Stress, Post Trawna t ic Stress Disorder , Biomarker , Suicide , Combat 16. SECURITY CLASSIFICATION OF: 17. LIMITATION 18. NUMBER...Project 2a ( Neuro -cognition Study) deploying Marines from 1/7 were assessed during the allotted 2012 timeframe. In total 570 Marines were available...Project 2 ( Neuro -cognition Study) remain current, as necessary for the data collection as noted above. Task 3: In coordination with HQMC, NIMH

  13. Definition Study PHARUS

    Science.gov (United States)

    1991-11-01

    definitie studie zijn gebruikt in het voorontwerp van het PHARUS systeem . TNO report STUDelft Page 6 ABSTRACT 3 SAMENVAlTING 4 CONTENTS 6 1 INTRODUCTION 9...University of Technology, Laboratory for Telecommunication and Remote Sensing Technology. FEL-TNO had tke lead and was responsible for the project management ...Aerospace Programs in Delft was responsible for the program management . The definition study PHARUS was started in the first half of 1988 and ended

  14. Representativity of TMA studies.

    Science.gov (United States)

    Sauter, Guido

    2010-01-01

    The smaller the portion of a tumor sample that is analyzed becomes, the higher is the risk of missing important histological or molecular features that might be present only in a subset of tumor cells. Many researchers have, therefore, suggested using larger tissue cores or multiple cores from the same donor tissue to enhance the representativity of TMA studies. However, numerous studies comparing the results of TMA studies with the findings from conventional large sections have shown that all well-established associations between molecular markers and tumor phenotype or patient prognosis can be reproduced with TMAs even if only one single 0.6 mm tissue spot is analyzed. Moreover, the TMA technology has proven to be superior to large section analysis in finding new clinically relevant associations. The high number of samples that are typically included in TMA studies, and the unprecedented degree of standardization during TMA experiments and analysis often give TMA studies an edge over traditional large-section studies.

  15. Networked Microgrids Scoping Study

    Energy Technology Data Exchange (ETDEWEB)

    Backhaus, Scott N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dobriansky, Larisa [General MicroGrids, San Diego, CA (United States); Glover, Steve [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Liu, Chen-Ching [Washington State Univ., Pullman, WA (United States); Looney, Patrick [Brookhaven National Lab. (BNL), Upton, NY (United States); Mashayekh, Salman [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Pratt, Annabelle [National Renewable Energy Lab. (NREL), Golden, CO (United States); Schneider, Kevin [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stadler, Michael [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Starke, Michael [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wang, Jianhui [Argonne National Lab. (ANL), Argonne, IL (United States); Yue, Meng [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-12-05

    Much like individual microgrids, the range of opportunities and potential architectures of networked microgrids is very diverse. The goals of this scoping study are to provide an early assessment of research and development needs by examining the benefits of, risks created by, and risks to networked microgrids. At this time there are very few, if any, examples of deployed microgrid networks. In addition, there are very few tools to simulate or otherwise analyze the behavior of networked microgrids. In this setting, it is very difficult to evaluate networked microgrids systematically or quantitatively. At this early stage, this study is relying on inputs, estimations, and literature reviews by subject matter experts who are engaged in individual microgrid research and development projects, i.e., the authors of this study The initial step of the study gathered input about the potential opportunities provided by networked microgrids from these subject matter experts. These opportunities were divided between the subject matter experts for further review. Part 2 of this study is comprised of these reviews. Part 1 of this study is a summary of the benefits and risks identified in the reviews in Part 2 and synthesis of the research needs required to enable networked microgrids.

  16. Image-Based Three-Dimensional Analysis to Characterize the Texture of Porous Scaffolds

    Directory of Open Access Journals (Sweden)

    Diana Massai

    2014-01-01

    Full Text Available The aim of the present study is to characterize the microstructure of composite scaffolds for bone tissue regeneration containing different ratios of chitosan/gelatin blend and bioactive glasses. Starting from realistic 3D models of the scaffolds reconstructed from micro-CT images, the level of heterogeneity of scaffold architecture is evaluated performing a lacunarity analysis. The results demonstrate that the presence of the bioactive glass component affects not only macroscopic features such as porosity, but mainly scaffold microarchitecture giving rise to structural heterogeneity, which could have an impact on the local cell-scaffold interaction and scaffold performances. The adopted approach allows to investigate the scale-dependent pore distribution within the scaffold and the related structural heterogeneity features, providing a comprehensive characterization of the scaffold texture.

  17. Image-Based Three-Dimensional Analysis to Characterize the Texture of Porous Scaffolds

    Science.gov (United States)

    Pennella, Francesco; Gallo, Diego; Ciardelli, Gianluca; Bignardi, Cristina; Audenino, Alberto; Morbiducci, Umberto

    2014-01-01

    The aim of the present study is to characterize the microstructure of composite scaffolds for bone tissue regeneration containing different ratios of chitosan/gelatin blend and bioactive glasses. Starting from realistic 3D models of the scaffolds reconstructed from micro-CT images, the level of heterogeneity of scaffold architecture is evaluated performing a lacunarity analysis. The results demonstrate that the presence of the bioactive glass component affects not only macroscopic features such as porosity, but mainly scaffold microarchitecture giving rise to structural heterogeneity, which could have an impact on the local cell-scaffold interaction and scaffold performances. The adopted approach allows to investigate the scale-dependent pore distribution within the scaffold and the related structural heterogeneity features, providing a comprehensive characterization of the scaffold texture. PMID:24995272

  18. Obtaining the borders of urban areas

    CERN Document Server

    Comin, Cesar Henrique; Costa, Luciano da Fontoura

    2015-01-01

    The access to an ever increasing amount of information in the modern world gave rise to the development of many quantitative indicators about urban regions in the globe. Therefore, there is a growing need for a precise definition of how to delimit urban regions, so as to allow proper respective characterization and modeling. Here we present a straightforward methodology to automatically detect urban region borders. The method is based on the density of street crossings around a single seed point associated to the urban area of interest. We exemplify the potential of the methodology by characterizing the geometry and topology of 21 urban regions obtained from 8 distinct countries. The geometry is studied by employing the lacunarity measurement, which is associated to the regularity of holes contained in a pattern. The topology is analyzed by associating the betweenness centrality of the streets with their respective class, such as motorway or residential, obtained from a database.

  19. Lacunary Fourier Series for Compact Quantum Groups

    Science.gov (United States)

    Wang, Simeng

    2016-05-01

    This paper is devoted to the study of Sidon sets, {Λ(p)} -sets and some related notions for compact quantum groups. We establish several different characterizations of Sidon sets, and in particular prove that any Sidon set in a discrete group is a strong Sidon set in the sense of Picardello. We give several relations between Sidon sets, {Λ(p)} -sets and lacunarities for L p -Fourier multipliers, generalizing a previous work by Blendek and Michalic̆ek. We also prove the existence of {Λ(p)} -sets for orthogonal systems in noncommutative L p -spaces, and deduce the corresponding properties for compact quantum groups. Central Sidon sets are also discussed, and it turns out that the compact quantum groups with the same fusion rules and the same dimension functions have identical central Sidon sets. Several examples are also included.

  20. Lipid Transport through the Fetoplacental Barrier by the Fatty Acid-Binding Proteins in Pregnant Women with Herpes Virus Infection in the third Trimester

    Directory of Open Access Journals (Sweden)

    Michael T. Lucenko, PhD, ScD

    2012-12-01

    Full Text Available In this study, the transport of the long chain polyunsaturated fatty acids (LCPUFAs from the lacunar blood through the syncytiotrophoblast of the placental villi to the fetal cord blood via a saturable protein-mediated mechanism by the heart-type fatty acid-binding proteins (H-FABPs has been examined. Exacerbation of the herpes simplex viruses (HSV-1 in the third trimester of gestation reduces the delivery of the fatty acid-binding proteins to the syncytiotrophoblast. During exacerbation of the HSV-1 infection, the selective transfer of the LCPUFAs across the syncytiotrophoblast basal plasma membrane into the fetal cord blood was observed. The supply of anti-inflammatory ω-3 PUFAs was reduced; however, the inflow of inflammatory arachidonic acid and other ω-6 PUFAs into the fetal blood was increased.