Investigation of varying gray scale levels for remote manipulation

NASA Technical Reports Server (NTRS)

Bierschwale, John M.; Stuart, Mark A.; Sampaio, Carlos E.

1991-01-01

A study was conducted to investigate the effects of variant monitor gray scale levels and workplace illumination levels on operators' ability to discriminate between different colors on a monochrome monitor. It was determined that 8-gray scale viewing resulted in significantly worse discrimination performance compared to 16- and 32-gray scale viewing and that there was only a negligible difference found between 16 and 32 shades of gray. Therefore, it is recommended that monitors used while performing remote manipulation tasks have 16 or above shades of gray since this evaluation has found levels lower than this to be unacceptable for color discrimination task. There was no significant performance difference found between a high and a low workplace illumination condition. Further analysis was conducted to determine which specific combinations of colors can be used in conjunction with each other to ensure errorfree color coding/brightness discrimination performance while viewing a monochrome monitor. It was found that 92 three-color combination and 9 four-color combinations could be used with 100 percent accuracy. The results can help to determine which gray scale levels should be provided on monochrome monitors as well as which colors to use to ensure the maximal performance of remotely-viewed color discrimination/coding tasks.

Inventory of forest and rangeland and detection of forest stress

NASA Technical Reports Server (NTRS)

Heller, R. C.; Aldrich, R. C.; Weber, F. P.; Driscoll, R. S. (Principal Investigator)

1973-01-01

The author has identified the following significant results. At the Atlanta site (226B) it was found that bulk color composites for October 15, 1972, and April 13, 1973, can be interpreted together to disclose the location of the perennial Kudzu vine (Pyeraria lobata). Land managers concerned with Kudzu eradication could use ERTS-1 to inventory locations over 200 meters (660 feet) square. Microdensitometer data collected on ERTS-1 Bulk photographic products for the Manitou test site (226C) have shown that the 15-step gray-scale tablets are not of systematic equal values corresponding to 1/14 the maximum radiant energy incident on the MSS sensor. The gray-scale values present a third-order polynomial function rather than a direct linear relationship. Although data collected on step tablets for precision photographic products appear more discrete, the density variation within blocks in almost as great as variations between blocks. These system errors will cause problems when attempting to analyze radiometric variances among vegetation and land use classes.

Effect of scaling and root planing on alveolar bone as measured by subtraction radiography.

PubMed

Hwang, You-Jeong; Fien, Matthew Jonas; Lee, Sam-Sun; Kim, Tae-Il; Seol, Yang-Jo; Lee, Yong-Moo; Ku, Young; Rhyu, In-Chul; Chung, Chong-Pyoung; Han, Soo-Boo

2008-09-01

Scaling and root planing of diseased periodontal pockets is fundamental to the treatment of periodontal disease. Although various clinical parameters have been used to assess the efficacy of this therapy, radiographic analysis of changes in bone density following scaling and root planing has not been extensively researched. In this study, digital subtraction radiography was used to analyze changes that occurred in the periodontal hard tissues following scaling and root planing. Thirteen subjects with a total of 39 sites that presented with >3 mm of vertical bone loss were included in this study. Clinical examinations were performed and radiographs were taken prior to treatment and were repeated 6 months following scaling and root planing. Radiographic analysis was performed with computer-assisted radiographic evaluation software. Three regions of interest (ROI) were defined as the most coronal, middle, and apical portions of each defect. A fourth ROI was used for each site as a control region and was placed at a distant, untreated area. Statistical analysis was carried out to evaluate changes in the mean gray level at the coronal, middle, and apical region of each treated defect. Digital subtraction radiography revealed an increase in radiographic density in 101 of the 117 test regions (83.3%). A 256 gray level was used, and a value >128 was assumed to represent a density gain in the ROI. The average gray level increase was 18.65. Although the coronal, middle, and apical regions displayed increases in bone density throughout this study, the bone density of the apical ROI (gray level = 151.27 +/- 20.62) increased significantly more than the bone density of the coronal ROI (gray level = 139.19 +/- 21.78). A significant increase in bone density was seen in probing depths >5 mm compared to those <5 mm in depth. No significant difference was found with regard to bone-density changes surrounding single- versus multiple-rooted teeth. Scaling and root planing of diseased periodontal pockets can significantly increase radiographic alveolar bone density as demonstrated through the use of digital subtraction radiography.

8-Bit Gray Scale Images of Fingerprint Image Groups

National Institute of Standards and Technology Data Gateway

NIST 8-Bit Gray Scale Images of Fingerprint Image Groups (Web, free access)   The NIST database of fingerprint images contains 2000 8-bit gray scale fingerprint image pairs. A newer version of the compression/decompression software on the CDROM can be found at the website http://www.nist.gov/itl/iad/ig/nigos.cfm as part of the NBIS package.

The Role of Color and Morphologic Characteristics in Dermoscopic Diagnosis.

PubMed

Bajaj, Shirin; Marchetti, Michael A; Navarrete-Dechent, Cristian; Dusza, Stephen W; Kose, Kivanc; Marghoob, Ashfaq A

2016-06-01

Both colors and structures are considered important in the dermoscopic evaluation of skin lesions but their relative significance is unknown. To determine if diagnostic accuracy for common skin lesions differs between gray-scale and color dermoscopic images. A convenience sample of 40 skin lesions (8 nevi, 8 seborrheic keratoses, 7 basal cell carcinomas, 7 melanomas, 4 hemangiomas, 4 dermatofibromas, 2 squamous cell carcinomas [SCCs]) was selected and shown to attendees of a dermoscopy course (2014 Memorial Sloan Kettering Cancer Center dermoscopy course). Twenty lesions were shown only once, either in gray-scale (n = 10) or color (n = 10) (nonpaired). Twenty lesions were shown twice, once in gray-scale (n = 20) and once in color (n = 20) (paired). Participants provided their diagnosis and confidence level for each of the 60 images. Of the 261 attendees, 158 participated (60.5%) in the study. Most were attending physicians (n = 76 [48.1%]). Most participants were practicing or training in dermatology (n = 144 [91.1%]). The median (interquartile range) experience evaluating skin lesions and using dermoscopy of participants was 6 (13.5) and 2 (4.0) years, respectively. Diagnostic accuracy and confidence level of participants evaluating gray-scale and color images. Two separate analyses were performed: (1) an unpaired evaluation comparing gray-scale and color images shown either once or for the first time, and (2) a paired evaluation comparing pairs of gray-scale and color images of the same lesion. In univariate analysis of unpaired images, color images were less likely to be diagnosed correctly compared with gray-scale images (odds ratio [OR], 0.8; P < .001). Using gray-scale images as the reference, multivariate analyses of both unpaired and paired images found no association between correct lesion diagnosis and use of color images (OR, 1.0; P = .99, and OR, 1.2; P = .82, respectively). Stratified analysis of paired images using a color by diagnosis interaction term showed that participants were more likely to make a correct diagnosis of SCC and hemangioma in color (P < .001 for both comparisons) and dermatofibroma in gray-scale (P < .001). Morphologic characteristics (ie, structures and patterns), not color, provide the primary diagnostic clue in dermoscopy. Use of gray-scale images may improve teaching of dermoscopy to novices by emphasizing the evaluation of morphology.

Ultrasound analysis of gray-scale median value of carotid plaques is a useful reference index for cerebro-cardiovascular events in patients with type 2 diabetes.

PubMed

Ariyoshi, Kyoko; Okuya, Shigeru; Kunitsugu, Ichiro; Matsunaga, Kimie; Nagao, Yuko; Nomiyama, Ryuta; Takeda, Komei; Tanizawa, Yukio

2015-01-01

Measurements of plaque echogenicity, the gray-scale median (GSM), were shown to correlate inversely with risk factors for cerebro-cardiovascular disease (CVD). The eicosapentaenoic acid (EPA)/arachidonic acid (AA) ratio is a potential predictor of CVD risk. In the present study, we assessed the usefulness of carotid plaque GSM values and EPA/AA ratios in atherosclerotic diabetics. A total of 84 type 2 diabetics with carotid artery plaques were enrolled. On admission, platelet aggregation and lipid profiles, including EPA and AA, were examined. Using ultrasound, mean intima media thickness and plaque score were measured in carotid arteries. Plaque echogenicity was evaluated using computer-assisted quantification of GSM. The patients were then further observed for approximately 3 years. Gray-scale median was found to be a good marker of CVD events. On multivariate logistic regression analysis, GSM <32 and plaque score ≥5 were significantly associated with past history and onset of CVD during the follow-up period, the odds ratios being 7.730 (P = 0.014) and 4.601 (P = 0.046), respectively. EPA/AA showed a significant correlation with GSM (P = 0.012) and high-density lipoprotein cholesterol (P = 0.039), and an inverse correlation with platelet aggregation (P = 0.046) and triglyceride (P = 0.020). Although most patients with CVD had both low GSM and low EPA/AA values, an association of EPA/AA with CVD events could not be statistically confirmed. The present results suggest the GSM value to be useful as a reference index for CVD events in high-risk atherosclerotic diabetics. Associations of the EPA/AA ratio with known CVD risk factors warrant a larger and more extensive study to show the usefulness of this parameter.

Ultrasound analysis of gray-scale median value of carotid plaques is a useful reference index for cerebro-cardiovascular events in patients with type 2 diabetes

PubMed Central

Ariyoshi, Kyoko; Okuya, Shigeru; Kunitsugu, Ichiro; Matsunaga, Kimie; Nagao, Yuko; Nomiyama, Ryuta; Takeda, Komei; Tanizawa, Yukio

2015-01-01

Aims/Introduction Measurements of plaque echogenicity, the gray-scale median (GSM), were shown to correlate inversely with risk factors for cerebro-cardiovascular disease (CVD). The eicosapentaenoic acid (EPA)/arachidonic acid (AA) ratio is a potential predictor of CVD risk. In the present study, we assessed the usefulness of carotid plaque GSM values and EPA/AA ratios in atherosclerotic diabetics. Materials and Methods A total of 84 type 2 diabetics with carotid artery plaques were enrolled. On admission, platelet aggregation and lipid profiles, including EPA and AA, were examined. Using ultrasound, mean intima media thickness and plaque score were measured in carotid arteries. Plaque echogenicity was evaluated using computer-assisted quantification of GSM. The patients were then further observed for approximately 3 years. Results Gray-scale median was found to be a good marker of CVD events. On multivariate logistic regression analysis, GSM <32 and plaque score ≥5 were significantly associated with past history and onset of CVD during the follow-up period, the odds ratios being 7.730 (P = 0.014) and 4.601 (P = 0.046), respectively. EPA/AA showed a significant correlation with GSM (P = 0.012) and high-density lipoprotein cholesterol (P = 0.039), and an inverse correlation with platelet aggregation (P = 0.046) and triglyceride (P = 0.020). Although most patients with CVD had both low GSM and low EPA/AA values, an association of EPA/AA with CVD events could not be statistically confirmed. Conclusions The present results suggest the GSM value to be useful as a reference index for CVD events in high-risk atherosclerotic diabetics. Associations of the EPA/AA ratio with known CVD risk factors warrant a larger and more extensive study to show the usefulness of this parameter. PMID:25621138

Assessing the activity of perianal Crohn's disease: comparison of clinical indices and computer-assisted anal ultrasound.

PubMed

Losco, Alessandra; Viganò, Chiara; Conte, Dario; Cesana, Bruno Mario; Basilisco, Guido

2009-05-01

Assessing perianal disease activity is important for the treatment and prognosis of Crohn's disease (CD) patients, but the diagnostic accuracy of the activity indices has not yet been established. The aim of this study was to determine the accuracy and agreement of the Fistula Drainage Assessment (FDA), Perianal Disease Activity Index (PDAI), and computer-assisted anal ultrasound imaging (AUS). Sixty-two consecutive patients with CD and perianal fistulae underwent clinical, FDA, PDAI, and AUS evaluation. Perianal disease was considered active in the presence of visible fistula drainage and/or signs of local inflammation (induration and pain at digital compression) upon clinical examination. The AUS images were analyzed by calculating the mean gray-scale tone of the lesion. The PDAI and gray-scale tone values discriminating active and inactive perianal disease were defined using receiver operating characteristics statistics. Perianal disease was active in 46 patients. The accuracy of the FDA was 87% (confidence interval [CI]: 76%-94%). A PDAI of >4 and a mean gray-scale tone value of 117 maximized sensitivity and specificity; their diagnostic accuracy was, respectively, 87% (CI: 76%-94%) and 81% (CI: 69%-90%). The agreement of the 3 evaluations was fair to moderate. The addition of AUS to the PDAI or FDA increased their diagnostic accuracy to respectively 95% and 98%. The diagnostic accuracy of the FDA, PDAI, and computer-assisted AUS imaging was good in assessing perianal disease activity in patients with CD. The agreement between the techniques was fair to moderate. Overall accuracy can be increased by combining the FDA or PDAI with AUS.

Prospective evaluation of Doppler sonography to detect the twinkling artifact versus unenhanced computed tomography for identifying urinary tract calculi.

PubMed

Kielar, Ania Z; Shabana, Wael; Vakili, Maryam; Rubin, Jonathan

2012-10-01

The twinkling artifact is an emerging tool for identifying urinary tract calculi. The purpose of this prospective study was to evaluate the diagnostic accuracy of the twinkling artifact compared to unenhanced computed tomography in detecting urolithasis. After Research Ethics Board approval, 51 patients with flank pain from the emergency department were enrolled between November 2009 and September 2010. Patients received an unenhanced computed tomographic scan with 1.25-mm raw data and reformatted 5-mm axial and 2-mm coronal images. Blinded assessment of the urinary tract was performed with gray-scale and color Doppler interrogation. The number of calculi, location, size, kidney distance from the skin, body mass index of the patient, and sonographic image parameters were recorded. There were 35 right-sided and 38 left-sided renal calculi, 14 right-sided and 21 left-sided ureteric calculi, and 6 bladder calculi (total, 114 calculi). Thirteen patients had no calculi. The average calculus size was 2.6 mm (range, 1-9 mm). There were 6 false-positive and 22 false-negative instances of twinkling artifacts. On gray-scale evaluation looking for an echogenic focus with shadowing, there were 8 false-positive and 40 false-negative findings. The positive predictive value (PPV) of the twinkling artifact for identifying calculi was 94%, and the sensitivity was 83%. The PPV of gray-scale sonographic shadowing was only 64.9%, and the sensitivity was 80.2%. The twinkling artifact has a high PPV for detecting renal and urinary tract calculi. Evaluation for the twinkling artifact is a complementary technique to standard gray-scale shadowing of calculi and improves detection of urolithiasis on sonography.

Reliability of voxel gray values in cone beam computed tomography for preoperative implant planning assessment.

PubMed

Parsa, Azin; Ibrahim, Norliza; Hassan, Bassam; Motroni, Alessandro; van der Stelt, Paul; Wismeijer, Daniel

2012-01-01

To assess the reliability of cone beam computed tomography (CBCT) voxel gray value measurements using Hounsfield units (HU) derived from multislice computed tomography (MSCT) as a clinical reference (gold standard). Ten partially edentulous human mandibular cadavers were scanned by two types of computed tomography (CT) modalities: multislice CT and cone beam CT. On MSCT scans, eight regions of interest (ROI) designating the site for preoperative implant placement were selected in each mandible. The datasets from both CT systems were matched using a three-dimensional (3D) registration algorithm. The mean voxel gray values of the region around the implant sites were compared between MSCT and CBCT. Significant differences between the mean gray values obtained by CBCT and HU by MSCT were found. In all the selected ROIs, CBCT showed higher mean values than MSCT. A strong correlation (R=0.968) between mean voxel gray values of CBCT and mean HU of MSCT was determined. Voxel gray values from CBCT deviate from actual HU units. However, a strong linear correlation exists, which may permit deriving actual HU units from CBCT using linear regression models.

Quantification of dental prostheses on cone‐beam CT images by the Taguchi method

PubMed Central

Kuo, Rong‐Fu; Fang, Kwang‐Ming; TY, Wong

2016-01-01

The gray values accuracy of dental cone‐beam computed tomography (CBCT) is affected by dental metal prostheses. The distortion of dental CBCT gray values could lead to inaccuracies of orthodontic and implant treatment. The aim of this study was to quantify the effect of scanning parameters and dental metal prostheses on the accuracy of dental cone‐beam computed tomography (CBCT) gray values using the Taguchi method. Eight dental model casts of an upper jaw including prostheses, and a ninth prosthesis‐free dental model cast, were scanned by two dental CBCT devices. The mean gray value of the selected circular regions of interest (ROIs) were measured using dental CBCT images of eight dental model casts and were compared with those measured from CBCT images of the prosthesis‐free dental model cast. For each image set, four consecutive slices of gingiva were selected. The seven factors (CBCTs, occlusal plane canting, implant connection, prosthesis position, coping material, coping thickness, and types of dental restoration) were used to evaluate scanning parameter and dental prostheses effects. Statistical methods of signal to noise ratio (S/N) and analysis of variance (ANOVA) with 95% confidence were applied to quantify the effects of scanning parameters and dental prostheses on dental CBCT gray values accuracy. For ROIs surrounding dental prostheses, the accuracy of CBCT gray values were affected primarily by implant connection (42%), followed by type of restoration (29%), prostheses position (19%), coping material (4%), and coping thickness (4%). For a single crown prosthesis (without support of implants) placed in dental model casts, gray value differences for ROIs 1–9 were below 12% and gray value differences for ROIs 13–18 away from prostheses were below 10%. We found the gray value differences set to be between 7% and 8% for regions next to a single implant‐supported titanium prosthesis, and between 46% and 59% for regions between double implant‐supported, nickel‐chromium alloys (Ni‐Cr) prostheses. Quantification of the effect of prostheses and scanning parameters on dental CBCT gray values was assessed. PACS numbers: 87.59.bd, 87.57Q PMID:26894354

Automatic Brain Portion Segmentation From Magnetic Resonance Images of Head Scans Using Gray Scale Transformation and Morphological Operations.

PubMed

Somasundaram, Karuppanagounder; Ezhilarasan, Kamalanathan

2015-01-01

To develop an automatic skull stripping method for magnetic resonance imaging (MRI) of human head scans. The proposed method is based on gray scale transformation and morphological operations. The proposed method has been tested with 20 volumes of normal T1-weighted images taken from Internet Brain Segmentation Repository. Experimental results show that the proposed method gives better results than the popular skull stripping methods Brain Extraction Tool and Brain Surface Extractor. The average value of Jaccard and Dice coefficients are 0.93 and 0.962 respectively. In this article, we have proposed a novel skull stripping method using intensity transformation and morphological operations. This is a low computational complexity method but gives competitive or better results than that of the popular skull stripping methods Brain Surface Extractor and Brain Extraction Tool.

Histogram-based adaptive gray level scaling for texture feature classification of colorectal polyps

NASA Astrophysics Data System (ADS)

Pomeroy, Marc; Lu, Hongbing; Pickhardt, Perry J.; Liang, Zhengrong

2018-02-01

Texture features have played an ever increasing role in computer aided detection (CADe) and diagnosis (CADx) methods since their inception. Texture features are often used as a method of false positive reduction for CADe packages, especially for detecting colorectal polyps and distinguishing them from falsely tagged residual stool and healthy colon wall folds. While texture features have shown great success there, the performance of texture features for CADx have lagged behind primarily because of the more similar features among different polyps types. In this paper, we present an adaptive gray level scaling and compare it to the conventional equal-spacing of gray level bins. We use a dataset taken from computed tomography colonography patients, with 392 polyp regions of interest (ROIs) identified and have a confirmed diagnosis through pathology. Using the histogram information from the entire ROI dataset, we generate the gray level bins such that each bin contains roughly the same number of voxels Each image ROI is the scaled down to two different numbers of gray levels, using both an equal spacing of Hounsfield units for each bin, and our adaptive method. We compute a set of texture features from the scaled images including 30 gray level co-occurrence matrix (GLCM) features and 11 gray level run length matrix (GLRLM) features. Using a random forest classifier to distinguish between hyperplastic polyps and all others (adenomas and adenocarcinomas), we find that the adaptive gray level scaling can improve performance based on the area under the receiver operating characteristic curve by up to 4.6%.

Accuracy improvement in laser stripe extraction for large-scale triangulation scanning measurement system

NASA Astrophysics Data System (ADS)

Zhang, Yang; Liu, Wei; Li, Xiaodong; Yang, Fan; Gao, Peng; Jia, Zhenyuan

2015-10-01

Large-scale triangulation scanning measurement systems are widely used to measure the three-dimensional profile of large-scale components and parts. The accuracy and speed of the laser stripe center extraction are essential for guaranteeing the accuracy and efficiency of the measuring system. However, in the process of large-scale measurement, multiple factors can cause deviation of the laser stripe center, including the spatial light intensity distribution, material reflectivity characteristics, and spatial transmission characteristics. A center extraction method is proposed for improving the accuracy of the laser stripe center extraction based on image evaluation of Gaussian fitting structural similarity and analysis of the multiple source factors. First, according to the features of the gray distribution of the laser stripe, evaluation of the Gaussian fitting structural similarity is estimated to provide a threshold value for center compensation. Then using the relationships between the gray distribution of the laser stripe and the multiple source factors, a compensation method of center extraction is presented. Finally, measurement experiments for a large-scale aviation composite component are carried out. The experimental results for this specific implementation verify the feasibility of the proposed center extraction method and the improved accuracy for large-scale triangulation scanning measurements.

Prostate ultrasound--for urologists only?

PubMed

Frauscher, Ferdinand; Gradl, Johann; Pallwein, Leo

2005-11-23

The value of ultrasound (US) in the diagnosis of prostate cancer has dramatically increased in the past decade. This is mainly related to the increasing incidence of prostate cancer, the most common cancer in men and one of the most important causes of death from cancer in men. The value of conventional gray-scale US for prostate cancer detection has been extensively investigated, and has shown a low sensitivity and specificity. Therefore conventional gray-scale US is mainly used by urologists for guiding systematic prostate biopsies. With the development of new US techniques, such as color and power Doppler US, and the introduction of US contrast agents, the role of US for prostate cancer detection has dramatically changed. Advances in US techniques were introduced to further increase the value of US contrast agents. Although most of these developments in US techniques, which use the interaction of the contrast agent with the transmitted US waves, are very sensitive for the detection of microbubbles, they are mostly unexplored, in particular for prostate applications. Early reports of contrast-enhanced US investigations of blood flow of the prostate have shown that contrast-enhanced US adds important information to the conventional gray-scale US technique. Furthermore, elastography or 'strain imaging' seems to have great potential in prostate cancer detection. Since these new advances in US are very sophisticated and need a long learning curve, radiologists, who are overall better trained with these new US techniques, will play a more important role in prostate cancer diagnosis. Current trends show that these new US techniques may allow for targeted biopsies and therefore replace the current 'gold standard' for prostate cancer detection--the systematic biopsy. Consequently the use of these new US techniques for the detection and clinical staging of prostate cancer is promising. However, future clinical trials will be needed to determine if the promise of these new US advances of the prostate evolves into clinical application. International Cancer Imaging Society.

Efficacy of Strain Elastography in Diagnosis and Staging of Acute Appendicitis in Pediatric Patients.

PubMed

Arslan, Harun; Akdemir, Zülküf; Yavuz, Alpaslan; Gökçal, Fahri; Parlakgümüş, Cemal; İslamoglu, Necat; Akdeniz, Hüseyin

2018-02-11

BACKGROUND In the present study, the role and efficiency of strain elastography (SE) were evaluated in diagnosis and staging of acute appendicitis in pediatric patients. MATERIAL AND METHODS We enrolled 225 pediatric patients with suspected clinical and laboratory findings of acute appendicitis. Gray-scale sonographic findings were recorded and staging was made by the colorization method of SE imaging. Appendectomy was performed in all patients and the results of the surgical pathology were compared with the imaging findings. The sensitivity, specificity, and accuracy of SE imaging were determined in terms of evaluating the "acute appendicitis". RESULTS Sonographic evaluation revealed acute appendicitis in 100 patients. Regarding the SE analysis, cases with appendicitis were classified into 3 groups as: mild (n=17), moderate (n=39), and severe (n=44). The pathological evaluation revealed 95 different stages of appendicitis and normal appendix in 5 cases: acute focal (n=10), acute suppurative (n=46), phlegmonous (n=27), and perforated (n=12), regarding the results of surgical pathology. Five patients with pathologically proven "normal" appendix were noted as "mild stage appendicitis" based on gray scale and SE analysis. In total, when gray-scale and SE results were compared with pathology results regardless of the stage of appendicitis, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rates were 96%, 96%, 95%, 96.8%, and 96%, respectively. No statistically significant difference was detected between other groups (P<0.05). CONCLUSIONS In acute appendicitis, the use of SE imaging as a supportive method for the clinical approach can be useful in diagnosis, and its results are closely correlated with the histopathologic stage of appendix inflammation.

Real-time gray-scale photolithography for fabrication of continuous microstructure

NASA Astrophysics Data System (ADS)

Peng, Qinjun; Guo, Yongkang; Liu, Shijie; Cui, Zheng

2002-10-01

A novel real-time gray-scale photolithography technique for the fabrication of continuous microstructures that uses a LCD panel as a real-time gray-scale mask is presented. The principle of design of the technique is explained, and computer simulation results based on partially coherent imaging theory are given for the patterning of a microlens array and a zigzag grating. An experiment is set up, and a microlens array and a zigzag grating on panchromatic silver halide sensitized gelatin with trypsinase etching are obtained.

Evaluation of carotid plaque echogenicity based on the integral of the cumulative probability distribution using gray-scale ultrasound images.

PubMed

Huang, Xiaowei; Zhang, Yanling; Meng, Long; Abbott, Derek; Qian, Ming; Wong, Kelvin K L; Zheng, Rongqing; Zheng, Hairong; Niu, Lili

2017-01-01

Carotid plaque echogenicity is associated with the risk of cardiovascular events. Gray-scale median (GSM) of the ultrasound image of carotid plaques has been widely used as an objective method for evaluation of plaque echogenicity in patients with atherosclerosis. We proposed a computer-aided method to evaluate plaque echogenicity and compared its efficiency with GSM. One hundred and twenty-five carotid plaques (43 echo-rich, 35 intermediate, 47 echolucent) were collected from 72 patients in this study. The cumulative probability distribution curves were obtained based on statistics of the pixels in the gray-level images of plaques. The area under the cumulative probability distribution curve (AUCPDC) was calculated as its integral value to evaluate plaque echogenicity. The classification accuracy for three types of plaques is 78.4% (kappa value, κ = 0.673), when the AUCPDC is used for classifier training, whereas GSM is 64.8% (κ = 0.460). The receiver operating characteristic curves were produced to test the effectiveness of AUCPDC and GSM for the identification of echolucent plaques. The area under the curve (AUC) was 0.817 when AUCPDC was used for training the classifier, which is higher than that achieved using GSM (AUC = 0.746). Compared with GSM, the AUCPDC showed a borderline association with coronary heart disease (Spearman r = 0.234, p = 0.050). Our experimental results suggest that AUCPDC analysis is a promising method for evaluation of plaque echogenicity and predicting cardiovascular events in patients with plaques.

A Fixed-Pattern Noise Correction Method Based on Gray Value Compensation for TDI CMOS Image Sensor.

PubMed

Liu, Zhenwang; Xu, Jiangtao; Wang, Xinlei; Nie, Kaiming; Jin, Weimin

2015-09-16

In order to eliminate the fixed-pattern noise (FPN) in the output image of time-delay-integration CMOS image sensor (TDI-CIS), a FPN correction method based on gray value compensation is proposed. One hundred images are first captured under uniform illumination. Then, row FPN (RFPN) and column FPN (CFPN) are estimated based on the row-mean vector and column-mean vector of all collected images, respectively. Finally, RFPN are corrected by adding the estimated RFPN gray value to the original gray values of pixels in the corresponding row, and CFPN are corrected by subtracting the estimated CFPN gray value from the original gray values of pixels in the corresponding column. Experimental results based on a 128-stage TDI-CIS show that, after correcting the FPN in the image captured under uniform illumination with the proposed method, the standard-deviation of row-mean vector decreases from 5.6798 to 0.4214 LSB, and the standard-deviation of column-mean vector decreases from 15.2080 to 13.4623 LSB. Both kinds of FPN in the real images captured by TDI-CIS are eliminated effectively with the proposed method.

ENSO-Type Signals Recorded in the Late Cretaceous Laminated Sediments of Songliao Basin, Northeast China

NASA Astrophysics Data System (ADS)

Yu, E.; Wang, C.; Hinnov, L. A.; Wu, H.

2014-12-01

The quasi-periodic, ca. 2-7 year El Niño Southern Oscillation (ENSO) phenomenon globally influences the inter-annual variability of temperature and precipitation. Global warming may increase the frequency of extreme ENSO events. Although the Cretaceous plate tectonic configuration was different from today, the sedimentary record suggests that ENSO-type oscillations had existed at the time of Cretaceous greenhouse conditions. Cored Cretaceous lacustrine sediments from the Songliao Basin in Northeast China (SK-1 cores from the International Continental Drilling Program) potentially offer a partially varved record of Cretaceous paleoclimate. Fourteen polished thin sections from the depth interval 1096.12-1096.53 m with an age of 84.4 Ma were analyzed by optical and scanning electron microscopy (SEM). ImageJ software was applied to extract gray scale curves from optical images at pixel resolution. We tracked minimum values of the gray scale curves to estimate the thickness of each lamina. Five sedimentary structures were recognized: flaser bedding, wavy bedding, lenticular bedding, horizontal bedding, and massive layers. The mean layer thicknesses with different sedimentary structures range from 116 to 162mm, very close to the mean sedimentation rate estimated for this sampled interval, 135mm/year, indicating that the layers bounded by pure clay lamina with the minimum gray values are varves. SEM images indicate that a varve is composed, in succession, of one lamina rich in coarse silt, one lamina rich in fine silt, one clay-rich lamina with some silt, and one clay-rich lamina. This suggests that a Cretaceous year featured four distinct depositional seasons, two of which were rainy and the others were lacking precipitation. Spectral analysis of extended intervals of the tuned gray scale curve indicates the presence of inter-annual periodicities of 2.2-2.7 yr, 3.5-6.1 year, and 10.1-14.5 year consistent with those of modern ENSO cycles and solar cycles, as well as those recognized in the Cretaceous Arctic and Marca Shale of California.

Prostate: techniques, results, and potential applications of color Doppler US scanning.

PubMed

Rifkin, M D; Sudakoff, G S; Alexander, A A

1993-02-01

Color Doppler ultrasound (US) scanning and conventional endorectal gray-scale US of the prostate were performed in 619 patients. Pathologic correlation was available in all cases after US-guided transrectal biopsy. There were 132 cancers in 121 men, 13 foci of atypia in 10 men, 33 foci of inflammation in 31 men, and 469 benign lesions in 457 men. Two hundred seventy patients with abnormal areas of flow identified at color Doppler scanning also underwent spectral waveform analysis of the area of potential concern. No statistical difference in the mean resistive indexes was identified in any patient (P = .25; Scheffe F test, analysis of variance). All malignant lesions had abnormalities demonstrated at gray-scale US and/or focal or diffuse abnormal flow demonstrated at color Doppler scanning. Of the 132 cancers, 123 (93%) had corresponding gray-scale abnormalities and 114 (86%) demonstrated abnormal flow at color Doppler imaging. Nine of the 132 cancers (7%) had no obviously identifiable abnormality at gray-scale scanning but had distinctly abnormal flow at color Doppler scanning. Abnormal findings at color scanning without abnormal findings at gray-scale scanning occurred in eight of the 33 cases of inflammatory foci (24%) and in 24 of the 469 (5%) benign lesions.

Real-time monitoring of ultrasound imaging of clinical high intensity focused ultrasound (HIFU) exposures

NASA Astrophysics Data System (ADS)

Ter Haar, Gail; Kennedy, James; Leslie, Tom; Wu, Feng

2005-09-01

Currently, many clinical devices use the change in gray scale seen on a real-time ultrasound image for the assessment of the success of HIFU treatment. It has been shown previously that, for a single HIFU lesion, the presence of gray-scale change was indicative of successful ablation in 100% of cases for 1.6-MHz beams, and in 90% of cases for 0.8-MHz exposures. The absence of gray-scale change was a reliable indicator of lack of ablative damage only for 0.8-MHz exposures (80%) in 80% of exposures using 1.6-MHz beams there was a lesion even in the absence of gray-scale change. This study has been extended to more realistic clinical treatment protocols. The image appearance has been studied for the different volume ablation techniques that are used in the treatment of liver and kidney cancer. The results will be presented.

Investigating the scale-adaptivity of a shallow cumulus parameterization scheme with LES

NASA Astrophysics Data System (ADS)

Brast, Maren; Schemann, Vera; Neggers, Roel

2017-04-01

In this study we investigate the scale-adaptivity of a new parameterization scheme for shallow cumulus clouds in the gray zone. The Eddy-Diffusivity Multiple Mass-Flux (or ED(MF)n ) scheme is a bin-macrophysics scheme, in which subgrid transport is formulated in terms of discretized size densities. While scale-adaptivity in the ED-component is achieved using a pragmatic blending approach, the MF-component is filtered such that only the transport by plumes smaller than the grid size is maintained. For testing, ED(MF)n is implemented in a large-eddy simulation (LES) model, replacing the original subgrid-scheme for turbulent transport. LES thus plays the role of a non-hydrostatic testing ground, which can be run at different resolutions to study the behavior of the parameterization scheme in the boundary-layer gray zone. In this range convective cumulus clouds are partially resolved. We find that at high resolutions the clouds and the turbulent transport are predominantly resolved by the LES, and the transport represented by ED(MF)n is small. This partitioning changes towards coarser resolutions, with the representation of shallow cumulus clouds becoming exclusively carried by the ED(MF)n. The way the partitioning changes with grid-spacing matches the results of previous LES studies, suggesting some scale-adaptivity is captured. Sensitivity studies show that a scale-inadaptive ED component stays too active at high resolutions, and that the results are fairly insensitive to the number of transporting updrafts in the ED(MF)n scheme. Other assumptions in the scheme, such as the distribution of updrafts across sizes and the value of the area fraction covered by updrafts, are found to affect the location of the gray zone.

Gray matter and white matter abnormalities in online game addiction.

PubMed

Weng, Chuan-Bo; Qian, Ruo-Bing; Fu, Xian-Ming; Lin, Bin; Han, Xiao-Peng; Niu, Chao-Shi; Wang, Ye-Han

2013-08-01

Online game addiction (OGA) has attracted greater attention as a serious public mental health issue. However, there are only a few brain magnetic resonance imaging studies on brain structure about OGA. In the current study, we used voxel-based morphometry (VBM) analysis and tract-based spatial statistics (TBSS) to investigate the microstructural changes in OGA and assessed the relationship between these morphology changes and the Young's Internet Addiction Scale (YIAS) scores within the OGA group. Compared with healthy subjects, OGA individuals showed significant gray matter atrophy in the right orbitofrontal cortex, bilateral insula, and right supplementary motor area. According to TBSS analysis, OGA subjects had significantly reduced FA in the right genu of corpus callosum, bilateral frontal lobe white matter, and right external capsule. Gray matter volumes (GMV) of the right orbitofrontal cortex, bilateral insula and FA values of the right external capsule were significantly positively correlated with the YIAS scores in the OGA subjects. Our findings suggested that microstructure abnormalities of gray and white matter were present in OGA subjects. This finding may provide more insights into the understanding of the underlying neural mechanisms of OGA. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Skeletonization with hollow detection on gray image by gray weighted distance transform

NASA Astrophysics Data System (ADS)

Bhattacharya, Prabir; Qian, Kai; Cao, Siqi; Qian, Yi

1998-10-01

A skeletonization algorithm that could be used to process non-uniformly distributed gray-scale images with hollows was presented. This algorithm is based on the Gray Weighted Distance Transformation. The process includes a preliminary phase of investigation in the hollows in the gray-scale image, whether these hollows are considered as topological constraints for the skeleton structure depending on their statistically significant depth. We then extract the resulting skeleton that has certain meaningful information for understanding the object in the image. This improved algorithm can overcome the possible misinterpretation of some complicated images in the extracted skeleton, especially in images with asymmetric hollows and asymmetric features. This algorithm can be executed on a parallel machine as all the operations are executed in local. Some examples are discussed to illustrate the algorithm.

Correlation between white matter damage and gray matter lesions in multiple sclerosis patients.

PubMed

Han, Xue-Mei; Tian, Hong-Ji; Han, Zheng; Zhang, Ce; Liu, Ying; Gu, Jie-Bing; Bakshi, Rohit; Cao, Xia

2017-05-01

We observed the characteristics of white matter fibers and gray matter in multiple sclerosis patients, to identify changes in diffusion tensor imaging fractional anisotropy values following white matter fiber injury. We analyzed the correlation between fractional anisotropy values and changes in whole-brain gray matter volume. The participants included 20 patients with relapsing-remitting multiple sclerosis and 20 healthy volunteers as controls. All subjects underwent head magnetic resonance imaging and diffusion tensor imaging. Our results revealed that fractional anisotropy values decreased and gray matter volumes were reduced in the genu and splenium of corpus callosum, left anterior thalamic radiation, hippocampus, uncinate fasciculus, right corticospinal tract, bilateral cingulate gyri, and inferior longitudinal fasciculus in multiple sclerosis patients. Gray matter volumes were significantly different between the two groups in the right frontal lobe (superior frontal, middle frontal, precentral, and orbital gyri), right parietal lobe (postcentral and inferior parietal gyri), right temporal lobe (caudate nucleus), right occipital lobe (middle occipital gyrus), right insula, right parahippocampal gyrus, and left cingulate gyrus. The voxel sizes of atrophic gray matter positively correlated with fractional anisotropy values in white matter association fibers in the patient group. These findings suggest that white matter fiber bundles are extensively injured in multiple sclerosis patients. The main areas of gray matter atrophy in multiple sclerosis are the frontal lobe, parietal lobe, caudate nucleus, parahippocampal gyrus, and cingulate gyrus. Gray matter atrophy is strongly associated with white matter injury in multiple sclerosis patients, particularly with injury to association fibers.

Effect of color coding and subtraction on the accuracy of contrast echocardiography

NASA Technical Reports Server (NTRS)

Pasquet, A.; Greenberg, N.; Brunken, R.; Thomas, J. D.; Marwick, T. H.

1999-01-01

BACKGROUND: Contrast echocardiography may be used to assess myocardial perfusion. However, gray scale assessment of myocardial contrast echocardiography (MCE) is difficult because of variations in regional backscatter intensity, difficulties in distinguishing varying shades of gray, and artifacts or attenuation. We sought to determine whether the assessment of rest myocardial perfusion by MCE could be improved with subtraction and color coding. METHODS AND RESULTS: MCE was performed in 31 patients with previous myocardial infarction with a 2nd generation agent (NC100100, Nycomed AS), using harmonic triggered or continuous imaging and gain settings were kept constant throughout the study. Digitized images were post processed by subtraction of baseline from contrast data and colorized to reflect the intensity of myocardial contrast. Gray scale MCE alone, MCE images combined with baseline and subtracted colorized images were scored independently using a 16 segment model. The presence and severity of myocardial contrast abnormalities were compared with perfusion defined by rest MIBI-SPECT. Segments that were not visualized by continuous (17%) or triggered imaging (14%) after color processing were excluded from further analysis. The specificity of gray scale MCE alone (56%) or MCE combined with baseline 2D (47%) was significantly enhanced by subtraction and color coding (76%, p<0.001) of triggered images. The accuracy of the gray scale approaches (respectively 52% and 47%) was increased to 70% (p<0.001). Similarly, for continuous images, the specificity of gray scale MCE with and without baseline comparison was 23% and 42% respectively, compared with 60% after post processing (p<0.001). The accuracy of colorized images (59%) was also significantly greater than gray scale MCE (43% and 29%, p<0.001). The sensitivity of MCE for both acquisitions was not altered by subtraction. CONCLUSION: Post-processing with subtraction and color coding significantly improves the accuracy and specificity of MCE for detection of perfusion defects.

Effect of color visualization and display hardware on the visual assessment of pseudocolor medical images

PubMed Central

Zabala-Travers, Silvina; Choi, Mina; Cheng, Wei-Chung

2015-01-01

Purpose: Even though the use of color in the interpretation of medical images has increased significantly in recent years, the ad hoc manner in which color is handled and the lack of standard approaches have been associated with suboptimal and inconsistent diagnostic decisions with a negative impact on patient treatment and prognosis. The purpose of this study is to determine if the choice of color scale and display device hardware affects the visual assessment of patterns that have the characteristics of functional medical images. Methods: Perfusion magnetic resonance imaging (MRI) was the basis for designing and performing experiments. Synthetic images resembling brain dynamic-contrast enhanced MRI consisting of scaled mixtures of white, lumpy, and clustered backgrounds were used to assess the performance of a rainbow (“jet”), a heated black-body (“hot”), and a gray (“gray”) color scale with display devices of different quality on the detection of small changes in color intensity. The authors used a two-alternative, forced-choice design where readers were presented with 600 pairs of images. Each pair consisted of two images of the same pattern flipped along the vertical axis with a small difference in intensity. Readers were asked to select the image with the highest intensity. Three differences in intensity were tested on four display devices: a medical-grade three-million-pixel display, a consumer-grade monitor, a tablet device, and a phone. Results: The estimates of percent correct show that jet outperformed hot and gray in the high and low range of the color scales for all devices with a maximum difference in performance of 18% (confidence intervals: 6%, 30%). Performance with hot was different for high and low intensity, comparable to jet for the high range, and worse than gray for lower intensity values. Similar performance was seen between devices using jet and hot, while gray performance was better for handheld devices. Time of performance was shorter with jet. Conclusions: Our findings demonstrate that the choice of color scale and display hardware affects the visual comparative analysis of pseudocolor images. Follow-up studies in clinical settings are being considered to confirm the results with patient images. PMID:26127048

[Improved euler algorithm for trend forecast model and its application to oil spectrum analysis].

PubMed

Zheng, Chang-song; Ma, Biao

2009-04-01

The oil atomic spectrometric analysis technology is one of the most important methods for fault diagnosis and state monitoring of large machine equipment. The gray method is preponderant in the trend forecast at the same time. With the use of oil atomic spectrometric analysis result and combining the gray forecast theory, the present paper established a gray forecast model of the Fe/Cu concentration trend in the power-shift steering transmission. Aiming at the shortage of the gray method used in the trend forecast, the improved Euler algorithm was put forward for the first time to resolve the problem of the gray model and avoid the non-precision that the old gray model's forecast value depends on the first test value. This new method can make the forecast value more precision as shown in the example. Combined with the threshold value of the oil atomic spectrometric analysis, the new method was applied on the Fe/Cu concentration forecast and the premonition of fault information was obtained. So we can take steps to prevent the fault and this algorithm can be popularized to the state monitoring in the industry.

Conventional vs  invert-grayscale X-ray for diagnosis of pneumothorax in the emergency setting.

PubMed

Musalar, Ekrem; Ekinci, Salih; Ünek, Orkun; Arş, Eda; Eren, Hakan Şevki; Gürses, Bengi; Aktaş, Can

2017-09-01

Pneumothorax is a pathologic condition in which air is accumulated between the visceral and parietal pleura. After clinical suspicion, in order to diagnose the severity of the condition, imaging is necessary. By using the help of Picture Archiving and Communication Systems (PACS) direct conventional X-rays are converted to gray-scale and this has become a preferred method among many physicians. Our study design was a case-control study with cross-over design study. Posterior-anterior chest X-rays of patients were evaluated for pneumothorax by 10 expert physicians with at least 3years of experience and who have used inverted gray-scale posterior anterior chest X-ray for diagnosing pneumothorax. The study included posterior anterior chest X-ray images of 268 patients of which 106 were diagnosed with spontaneous pneumothorax and 162 patients used as a control group. The sensitivity of Digital-conventional X-rays was found to be higher than that of inverted gray-scale images (95% CI (2,08-5,04), p<0,01). There was no statistically significant difference between the gold standard and digital-conventional images (95% CI (0,45-2,17), p=0,20), while the evaluations of the gray-scale images were found to be less sensitive for diagnosis (95% CI (3,16-5,67) p<0,01). Inverted gray-scale imaging is not a superior imaging modality over digital-conventional X-ray for the diagnosis of pneumothorax. Prospective studies should be performed where diagnostic potency of inverted gray-scale radiograms is tested against gold standard chest CT. Further research should compare inverted grayscale to lung ultrasound to assess them as alternatives prior to CT. Copyright © 2017 Elsevier Inc. All rights reserved.

Image quality assessment metric for frame accumulated image

NASA Astrophysics Data System (ADS)

Yu, Jianping; Li, Gang; Wang, Shaohui; Lin, Ling

2018-01-01

The medical image quality determines the accuracy of diagnosis, and the gray-scale resolution is an important parameter to measure image quality. But current objective metrics are not very suitable for assessing medical images obtained by frame accumulation technology. Little attention was paid to the gray-scale resolution, basically based on spatial resolution and limited to the 256 level gray scale of the existing display device. Thus, this paper proposes a metric, "mean signal-to-noise ratio" (MSNR) based on signal-to-noise in order to be more reasonable to evaluate frame accumulated medical image quality. We demonstrate its potential application through a series of images under a constant illumination signal. Here, the mean image of enough images was regarded as the reference image. Several groups of images by different frame accumulation and their MSNR were calculated. The results of the experiment show that, compared with other quality assessment methods, the metric is simpler, more effective, and more suitable for assessing frame accumulated images that surpass the gray scale and precision of the original image.

Role of "the frame cycle time" in portal dose imaging using an aS500-II EPID.

PubMed

Al Kattar Elbalaa, Zeina; Foulquier, Jean Noel; Orthuon, Alexandre; Elbalaa, Hanna; Touboul, Emmanuel

2009-09-01

This paper evaluates the role of an acquisition parameter, the frame cycle time "FCT", in the performance of an aS500-II EPID. The work presented rests on the study of the Varian EPID aS500-II and the image acquisition system 3 (IAS3). We are interested in integrated acquisition using asynchronous mode. For better understanding the image acquisition operation, we investigated the influence of the "frame cycle time" on the speed of acquisition, the pixel value of the averaged gray-scale frame and the noise, using 6 and 15MV X-ray beams and dose rates of 1-6Gy/min on 2100 C/D Linacs. In the integrated mode not synchronized to beam pulses, only one parameter the frame cycle time "FCT" influences the pixel value. The pixel value of the averaged gray-scale frame is proportional to this parameter. When the FCT <55ms (speed of acquisition V(f/s)>18 frames/s), the speed of acquisition becomes unstable and leads to a fluctuation of the portal dose response. A timing instability and saturation are detected when the dose per frame exceeds 1.53MU/frame. Rules were deduced to avoid saturation and to optimize this dosimetric mode. The choice of the acquisition parameter is essential for the accurate portal dose imaging.

A New Quantum Gray-Scale Image Encoding Scheme

NASA Astrophysics Data System (ADS)

Naseri, Mosayeb; Abdolmaleky, Mona; Parandin, Fariborz; Fatahi, Negin; Farouk, Ahmed; Nazari, Reza

2018-02-01

In this paper, a new quantum images encoding scheme is proposed. The proposed scheme mainly consists of four different encoding algorithms. The idea behind of the scheme is a binary key generated randomly for each pixel of the original image. Afterwards, the employed encoding algorithm is selected corresponding to the qubit pair of the generated randomized binary key. The security analysis of the proposed scheme proved its enhancement through both randomization of the generated binary image key and altering the gray-scale value of the image pixels using the qubits of randomized binary key. The simulation of the proposed scheme assures that the final encoded image could not be recognized visually. Moreover, the histogram diagram of encoded image is flatter than the original one. The Shannon entropies of the final encoded images are significantly higher than the original one, which indicates that the attacker can not gain any information about the encoded images. Supported by Kermanshah Branch, Islamic Azad University, Kermanshah, IRAN

Image editing with Adobe Photoshop 6.0.

PubMed

Caruso, Ronald D; Postel, Gregory C

2002-01-01

The authors introduce Photoshop 6.0 for radiologists and demonstrate basic techniques of editing gray-scale cross-sectional images intended for publication and for incorporation into computerized presentations. For basic editing of gray-scale cross-sectional images, the Tools palette and the History/Actions palette pair should be displayed. The History palette may be used to undo a step or series of steps. The Actions palette is a menu of user-defined macros that save time by automating an action or series of actions. Converting an image to 8-bit gray scale is the first editing function. Cropping is the next action. Both decrease file size. Use of the smallest file size necessary for the purpose at hand is recommended. Final file size for gray-scale cross-sectional neuroradiologic images (8-bit, single-layer TIFF [tagged image file format] at 300 pixels per inch) intended for publication varies from about 700 Kbytes to 3 Mbytes. Final file size for incorporation into computerized presentations is about 10-100 Kbytes (8-bit, single-layer, gray-scale, high-quality JPEG [Joint Photographic Experts Group]), depending on source and intended use. Editing and annotating images before they are inserted into presentation software is highly recommended, both for convenience and flexibility. Radiologists should find that image editing can be carried out very rapidly once the basic steps are learned and automated. Copyright RSNA, 2002

DART: a practical reconstruction algorithm for discrete tomography.

PubMed

Batenburg, Kees Joost; Sijbers, Jan

2011-09-01

In this paper, we present an iterative reconstruction algorithm for discrete tomography, called discrete algebraic reconstruction technique (DART). DART can be applied if the scanned object is known to consist of only a few different compositions, each corresponding to a constant gray value in the reconstruction. Prior knowledge of the gray values for each of the compositions is exploited to steer the current reconstruction towards a reconstruction that contains only these gray values. Based on experiments with both simulated CT data and experimental μCT data, it is shown that DART is capable of computing more accurate reconstructions from a small number of projection images, or from a small angular range, than alternative methods. It is also shown that DART can deal effectively with noisy projection data and that the algorithm is robust with respect to errors in the estimation of the gray values.

Conventional multi-slice computed tomography (CT) and cone-beam CT (CBCT) for computer-assisted implant placement. Part I: relationship of radiographic gray density and implant stability.

PubMed

Arisan, Volkan; Karabuda, Zihni Cüneyt; Avsever, Hakan; Özdemir, Tayfun

2013-12-01

The relationship of conventional multi-slice computed tomography (CT)- and cone beam CT (CBCT)-based gray density values and the primary stability parameters of implants that were placed by stereolithographic surgical guides were analyzed in this study. Eighteen edentulous jaws were randomly scanned by a CT (CT group) or a CBCT scanner (CBCT group) and radiographic gray density was measured from the planned implants. A total of 108 implants were placed, and primary stability parameters were measured by insertion torque value (ITV) and resonance frequency analysis (RFA). Radiographic and subjective bone quality classification (BQC) was also classified. Results were analyzed by correlation tests and multiple regressions (p < .05). CBCT-based gray density values (765 ± 97.32 voxel value) outside the implants were significantly higher than those of CT-based values (668.4 ± 110 Hounsfield unit, p < .001). Significant relations were found among the gray density values outside the implants, ITV (adjusted r(2)  = 0.6142, p = .001 and adjusted r(2)  = 0.5166, p = .0021), and RFA (adjusted r(2)  = 0.5642, p = .0017 and adjusted r(2)  = 0.5423, p = .0031 for CT and CBCT groups, respectively). Data from radiographic and subjective BQC were also in agreement. Similar to the gray density values of CT, that of CBCT could also be predictive for the subjective BQC and primary implant stability. Results should be confirmed on different CBCT scanners. © 2012 Wiley Periodicals, Inc.

Efficiency of quantitative echogenicity for investigating supraspinatus tendinopathy by the gray-level histogram of two ultrasound devices.

PubMed

Hsu, Jiun-Cheng; Chen, Po-Han; Huang, Kuo-Chin; Tsai, Yao-Hung; Hsu, Wei-Hsiu

2017-10-01

The gray-level histogram of ultrasound is a promising tool for scanning the hypoechogenic appearance of supraspinatus tendinopathy, and the aim of this study was to test the hypothesis that the gray-level value of the supraspinatus tendon in the painful shoulder has a lower value on B-mode images even though in different ultrasound devices. Sixty-seven patients who had unilateral shoulder pain with rotator cuff tendinopathy underwent bilateral shoulder ultrasonography, and we compared the mean gray-level values of painful shoulders and contralateral shoulders without any pain in each patient using two ultrasound devices. The echogenicity ratio (symptomatic/asymptomatic side) of two ultrasound devices was compared. A significant difference existed between the symptomatic shoulder and contralateral asymptomatic shoulder (p < 0.001) on the mean gray-level value measurements of each device. The symptomatic-to-asymptomatic tendon echogenicity ratio of device A was 0.919 ± 0.090 in the transverse plane and 0.937 ± 0.081 in the longitudinal plane, and the echogenicity ratio of device B was 0.899 ± 0.113 in the transverse plane and 0.940 ± 0.113 in the longitudinal plane. The decline of the mean gray-level value and the echogenicity ratio of the supraspinatus tendon in the painful shoulder may be utilized as a useful sonographic reference of unilateral rotator cuff lesions. Diagnostic level III.

Recall of patterns using binary and gray-scale autoassociative morphological memories

NASA Astrophysics Data System (ADS)

Sussner, Peter

2005-08-01

Morphological associative memories (MAM's) belong to a class of artificial neural networks that perform the operations erosion or dilation of mathematical morphology at each node. Therefore we speak of morphological neural networks. Alternatively, the total input effect on a morphological neuron can be expressed in terms of lattice induced matrix operations in the mathematical theory of minimax algebra. Neural models of associative memories are usually concerned with the storage and the retrieval of binary or bipolar patterns. Thus far, the emphasis in research on morphological associative memory systems has been on binary models, although a number of notable features of autoassociative morphological memories (AMM's) such as optimal absolute storage capacity and one-step convergence have been shown to hold in the general, gray-scale setting. In previous papers, we gained valuable insight into the storage and recall phases of AMM's by analyzing their fixed points and basins of attraction. We have shown in particular that the fixed points of binary AMM's correspond to the lattice polynomials in the original patterns. This paper extends these results in the following ways. In the first place, we provide an exact characterization of the fixed points of gray-scale AMM's in terms of combinations of the original patterns. Secondly, we present an exact expression for the fixed point attractor that represents the output of either a binary or a gray-scale AMM upon presentation of a certain input. The results of this paper are confirmed in several experiments using binary patterns and gray-scale images.

The BMPix and PEAK Tools: New Methods for Automated Laminae Recognition and Counting - Application to Glacial Varves From Antarctic Marine Sediment

NASA Astrophysics Data System (ADS)

Weber, M. E.; Reichelt, L.; Kuhn, G.; Thurow, J. W.; Ricken, W.

2009-12-01

We present software-based tools for rapid and quantitative detection of sediment lamination. The BMPix tool extracts color and gray-scale curves from images at ultrahigh (pixel) resolution. The PEAK tool uses the gray-scale curve and performs, for the first time, fully automated counting of laminae based on three methods. The maximum count algorithm counts every bright peak of a couplet of two laminae (annual resolution) in a Gaussian smoothed gray-scale curve. The zero-crossing algorithm counts every positive and negative halfway-passage of the gray-scale curve through a wide moving average. Hence, the record is separated into bright and dark intervals (seasonal resolution). The same is true for the frequency truncation method, which uses Fourier transformation to decompose the gray-scale curve into its frequency components, before positive and negative passages are count. We applied the new methods successfully to tree rings and to well-dated and already manually counted marine varves from Saanich Inlet before we adopted the tools to rather complex marine laminae from the Antarctic continental margin. In combination with AMS14C dating, we found convincing evidence that the laminations from three Weddell Sea sites represent true varves that were deposited on sediment ridges over several millennia during the last glacial maximum (LGM). There are apparently two seasonal layers of terrigenous composition, a coarser-grained bright layer, and a finer-grained dark layer. The new tools offer several advantages over previous tools. The counting procedures are based on a moving average generated from gray-scale curves instead of manual counting. Hence, results are highly objective and rely on reproducible mathematical criteria. Since PEAK associates counts with a specific depth, the thickness of each year or each season is also measured which is an important prerequisite for later spectral analysis. Since all information required to conduct the analysis is displayed graphically, interactive optimization of the counting algorithms can be achieved quickly and conveniently.

The optimization of microalgal culturing in liquid digestate after struvite precipitation using gray relational analysis.

PubMed

Jiang, Yiqi; Wang, Hong; Wang, Wannan; Deng, Liangwei; Wang, Wenguo

2018-05-01

Liquid digestate (LD) is highly turbid and contains ammonium (NH 4 + -N), which negatively influences microalgal growth. Therefore, a method of reducing LD turbidity and NH 4 + -N content is proposed, using struvite precipitation. To obtain struvite precipitation supernatant with an ideal UV transmittance, NH 4 + -N concentration, and N/P ratio for microalgal growth, the effects of pH and the molar ratio of NH 4 + /Mg 2+ /PO 4 3- were studied. Results show that the optimal NH 4 + /Mg 2+ /PO 4 3- molar ratio was 1:1.5:1.5, with a pH value of 8.5, following NaOH addition. Gray relational analysis (GRA) was applied to obtain a relative gray scale for the evaluation of multiple outputs. Results show that Chlorella regularis FACHB-1068 was the optimal microalgae species to support growth in the struvite precipitation supernatant. Using struvite precipitation and treatment with cultured C. regularis FACHB-1068 for 7 days, the removal efficiencies of NH 4 + -N, PO 4 3- -P, and COD in LD were 96.52, 99.33, and 35.30%, respectively.

Emerging factors associated with the decline of a gray fox population and multi-scale land cover associations of mesopredators in the Chicago metropolitan area.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Willingham, Alison N.; /Ohio State U.

Statewide surveys of furbearers in Illinois indicate gray (Urocyon cinereoargenteus) and red (Vulpes vulpes) foxes have experienced substantial declines in relative abundance, whereas other species such as raccoons (Procyon lotor) and coyotes (Canis latrans) have exhibited dramatic increases during the same time period. The cause of the declines of gray and red foxes has not been identified, and the current status of gray foxes remains uncertain. Therefore, I conducted a large-scale predator survey and tracked radiocollared gray foxes from 2004 to 2007 in order to determine the distribution, survival, cause-specific mortality sources and land cover associations of gray foxes inmore » an urbanized region of northeastern Illinois, and examined the relationships between the occurrence of gray fox and the presence other species of mesopredators, specifically coyotes and raccoons. Although generalist mesopredators are common and can reach high densities in many urban areas their urban ecology is poorly understood due to their secretive nature and wariness of humans. Understanding how mesopredators utilize urbanized landscapes can be useful in the management and control of disease outbreaks, mitigation of nuisance wildlife issues, and gaining insight into how mesopredators shape wildlife communities in highly fragmented areas. I examined habitat associations of raccoons, opossums (Didelphis virginiana), domestic cats (Felis catus), coyotes, foxes (gray and red), and striped skunks (Mephitis mephitis) at multiple spatial scales in an urban environment. Gray fox occurrence was rare and widely dispersed, and survival estimates were similar to other studies. Gray fox occurrence was negatively associated with natural and semi-natural land cover types. Fox home range size increased with increasing urban development suggesting that foxes may be negatively influenced by urbanization. Gray fox occurrence was not associated with coyote or raccoon presence. However, spatial avoidance and mortality due to coyote predation was documented and disease was a major mortality source for foxes. The declining relative abundance of gray fox in Illinois is likely a result of a combination of factors. Assessment of habitat associations indicated that urban mesopredators, particularly coyotes and foxes, perceived the landscape as relatively homogeneous and that urban mesopredators interacted with the environment at scales larger than that accommodated by remnant habitat patches. Coyote and fox presence was found to be associated with a high degree of urban development at large and intermediate spatial scales. However, at a small spatial scale fox presence was associated with high density urban land cover whereas coyote presence was associated with urban development with increased forest cover. Urban habitats can offer a diversity of prey items and anthropogenic resources and natural land cover could offer coyotes daytime resting opportunities in urban areas where they may not be as tolerated as smaller foxes. Raccoons and opossums were found to utilize moderately developed landscapes with interspersed natural and semi-natural land covers at a large spatial scale, which may facilitate dispersal movements. At intermediate and small spatial scales, both species were found to utilize areas that were moderately developed and included forested land cover. These results indicated that raccoons and opossums used natural areas in proximity to anthropogenic resources. At a large spatial scale, skunk presence was associated with highly developed landscapes with interspersed natural and semi-natural land covers. This may indicate that skunks perceived the urban matrix as more homogeneous than raccoons or opossums. At an intermediate spatial scale skunks were associated with moderate levels of development and increased forest cover, which indicated that they might utilize natural land cover in proximity to human-dominated land cover. At the smallest spatial scale skunk presence was associated with forested land cover surrounded by a suburban matrix. Compared to raccoons and opossums, skunks may not be tolerated in close proximity to human development in urban areas. Domestic cat presence was positively associated with increasingly urbanized and less diverse landscapes with decreased amounts of forest and urban open space at the largest spatial scale. At an intermediate spatial scale, cat presence was associated with a moderate degree of urban development characterized by increased forest cover, and at a small spatial scale cat presence was associated with a high degree of urbanization. Free-ranging domestic cats are often associated with human-dominated landscapes and likely utilize remnant natural habitat patches for hunting purposes, which may have implications for native predator and prey species existing in fragmented habitat patches in proximity to human development.« less

Correlation among body height, intelligence, and brain gray matter volume in healthy children.

PubMed

Taki, Yasuyuki; Hashizume, Hiroshi; Sassa, Yuko; Takeuchi, Hikaru; Asano, Michiko; Asano, Kohei; Kotozaki, Yuka; Nouchi, Rui; Wu, Kai; Fukuda, Hiroshi; Kawashima, Ryuta

2012-01-16

A significant positive correlation between height and intelligence has been demonstrated in children. Additionally, intelligence has been associated with the volume of gray matter in the brains of children. Based on these correlations, we analyzed the correlation among height, full-scale intelligence quotient (IQ) and gray matter volume applying voxel-based morphometry using data from the brain magnetic resonance images of 160 healthy children aged 5-18 years of age. As a result, body height was significantly positively correlated with brain gray matter volume. Additionally, the regional gray matter volume of several regions such as the bilateral prefrontal cortices, temporoparietal region, and cerebellum was significantly positively correlated with body height and that the gray matter volume of several of these regions was also significantly positively correlated with full-scale intelligence quotient (IQ) scores after adjusting for age, sex, and socioeconomic status. Our results demonstrate that gray and white matter volume may mediate the correlation between body height and intelligence in healthy children. Additionally, the correlations among gray and white matter volume, height, and intelligence may be at least partially explained by the effect of insulin-like growth factor-1 and growth hormones. Given the importance of the effect of environmental factors, especially nutrition, on height, IQ, and gray matter volume, the present results stress the importance of nutrition during childhood for the healthy maturation of body and brain. Copyright © 2011 Elsevier Inc. All rights reserved.

TVR-DART: A More Robust Algorithm for Discrete Tomography From Limited Projection Data With Automated Gray Value Estimation.

PubMed

Xiaodong Zhuge; Palenstijn, Willem Jan; Batenburg, Kees Joost

2016-01-01

In this paper, we present a novel iterative reconstruction algorithm for discrete tomography (DT) named total variation regularized discrete algebraic reconstruction technique (TVR-DART) with automated gray value estimation. This algorithm is more robust and automated than the original DART algorithm, and is aimed at imaging of objects consisting of only a few different material compositions, each corresponding to a different gray value in the reconstruction. By exploiting two types of prior knowledge of the scanned object simultaneously, TVR-DART solves the discrete reconstruction problem within an optimization framework inspired by compressive sensing to steer the current reconstruction toward a solution with the specified number of discrete gray values. The gray values and the thresholds are estimated as the reconstruction improves through iterations. Extensive experiments from simulated data, experimental μCT, and electron tomography data sets show that TVR-DART is capable of providing more accurate reconstruction than existing algorithms under noisy conditions from a small number of projection images and/or from a small angular range. Furthermore, the new algorithm requires less effort on parameter tuning compared with the original DART algorithm. With TVR-DART, we aim to provide the tomography society with an easy-to-use and robust algorithm for DT.

Multi-sparse dictionary colorization algorithm based on the feature classification and detail enhancement

NASA Astrophysics Data System (ADS)

Yan, Dan; Bai, Lianfa; Zhang, Yi; Han, Jing

2018-02-01

For the problems of missing details and performance of the colorization based on sparse representation, we propose a conceptual model framework for colorizing gray-scale images, and then a multi-sparse dictionary colorization algorithm based on the feature classification and detail enhancement (CEMDC) is proposed based on this framework. The algorithm can achieve a natural colorized effect for a gray-scale image, and it is consistent with the human vision. First, the algorithm establishes a multi-sparse dictionary classification colorization model. Then, to improve the accuracy rate of the classification, the corresponding local constraint algorithm is proposed. Finally, we propose a detail enhancement based on Laplacian Pyramid, which is effective in solving the problem of missing details and improving the speed of image colorization. In addition, the algorithm not only realizes the colorization of the visual gray-scale image, but also can be applied to the other areas, such as color transfer between color images, colorizing gray fusion images, and infrared images.

SU-E-J-248: Comparative Study of Two Image Registration for Image-Guided Radiation Therapy in Esophageal Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shang, K; Wang, J; Liu, D

2014-06-01

Purpose: Image-guided radiation therapy (IGRT) is one of the major treatment of esophageal cancer. Gray value registration and bone registration are two kinds of image registration, the purpose of this work is to compare which one is more suitable for esophageal cancer patients. Methods: Twenty three esophageal patients were treated by Elekta Synergy, CBCT images were acquired and automatically registered to planning kilovoltage CT scans according to gray value or bone registration. The setup errors were measured in the X, Y and Z axis, respectively. Two kinds of setup errors were analysed by matching T test statistical method. Results: Fourmore » hundred and five groups of CBCT images were available and the systematic and random setup errors (cm) in X, Y, Z directions were 0.35, 0.63, 0.29 and 0.31, 0.53, 0.21 with gray value registration, while 0.37, 0.64, 0.26 and 0.32, 0.55, 0.20 with bone registration, respectively. Compared with bone registration and gray value registration, the setup errors in X and Z axis have significant differences. In Y axis, both measurement comparison results of T value is 0.256 (P value > 0.05); In X axis, the T value is 5.287(P value < 0.05); In Z axis, the T value is −5.138 (P value < 0.05). Conclusion: Gray value registration is recommended in image-guided radiotherapy for esophageal cancer and the other thoracic tumors. Manual registration could be applied when it is necessary. Bone registration is more suitable for the head tumor and pelvic tumor department where composed of redundant interconnected and immobile bone tissue.« less

Fast Recall for Complex-Valued Hopfield Neural Networks with Projection Rules.

PubMed

Kobayashi, Masaki

2017-01-01

Many models of neural networks have been extended to complex-valued neural networks. A complex-valued Hopfield neural network (CHNN) is a complex-valued version of a Hopfield neural network. Complex-valued neurons can represent multistates, and CHNNs are available for the storage of multilevel data, such as gray-scale images. The CHNNs are often trapped into the local minima, and their noise tolerance is low. Lee improved the noise tolerance of the CHNNs by detecting and exiting the local minima. In the present work, we propose a new recall algorithm that eliminates the local minima. We show that our proposed recall algorithm not only accelerated the recall but also improved the noise tolerance through computer simulations.

[Establishment of the background color to make discrimination of domestic ethical tablets sharper and more feasible based on the analysis of their color distribution].

PubMed

Ishizaki, Makiko; Maeda, Hatsuo; Okamoto, Ikuko

2012-01-01

In Japan, pharmacists as well as patients often have problems distinguishing one ethical tablet from another because they can be very similar in color. In an attempt to solve this problem, we hypothesized using a background sheet of dark gray identified by N3.5 on the Munsell color system (Munsell CS). The colors of 369 and 656 ethical tablets in Japan and the USA, respectively, were measured. On the Munsell CS, the Japanese tablets were localized mostly in the range of hues between 10R∼10Y with values ≧ 8 and chroma ≦ 4, while the colors of the American tablets were scattered over the hue spectrum with a variety of values and chroma. Based on these findings, we examined the effects of background colors on discrimination between 5 tablets classified into yellow, yellow red, red, or mixed groups that represented typical domestic Japanese tablets. Background colors of light, medium, and dark gray, purple, blue, and blue green were selected based on a general concept on color discrimination. The influence of white 10 mm-ruled squares on background sheets was examined as well. Under JIS Z8723 conditions, 42 volunteers used a 4-point scale to evaluate how clearly they could discriminate between each set of tablets on each of the background sheets. Variance analysis of the obtained data with SPSS demonstrated that with healthy vision, use of a dark gray background sheet with or without ruled squares enabled the sharpest and most feasible discrimination between all sets of tablets. A similar test with dark gray and white clearly demonstrated that the former works as a practical background color for discrimination among different domestic Japanese tablets.

Marine Stratocumulus Cloud Fields off the Coast of Southern California Observed Using LANDSAT Imagery. Part II: Textural Analysis.

NASA Astrophysics Data System (ADS)

Welch, R. M.; Sengupta, S. K.; Kuo, K. S.

1988-04-01

Statistical measures of the spatial distributions of gray levels (cloud reflectivities) are determined for LANDSAT Multispectral Scanner digital data. Textural properties for twelve stratocumulus cloud fields, seven cumulus fields, and two cirrus fields are examined using the Spatial Gray Level Co-Occurrence Matrix method. The co-occurrence statistics are computed for pixel separations ranging from 57 m to 29 km and at angles of 0°, 45°, 90° and 135°. Nine different textual measures are used to define the cloud field spatial relationships. However, the measures of contrast and correlation appear to be most useful in distinguishing cloud structure.Cloud field macrotexture describes general cloud field characteristics at distances greater than the size of typical cloud elements. It is determined from the spatial asymptotic values of the texture measures. The slope of the texture curves at small distances provides a measure of the microtexture of individual cloud cells. Cloud fields composed primarily of small cells have very steep slopes and reach their asymptotic values at short distances from the origin. As the cells composing the cloud field grow larger, the slope becomes more gradual and the asymptotic distance increases accordingly. Low asymptotic values of correlation show that stratocumulus cloud fields have no large scale organized structure.Besides the ability to distinguish cloud field structure, texture appears to be a potentially valuable tool in cloud classification. Stratocumulus clouds are characterized by low values of angular second moment and large values of entropy. Cirrus clouds appear to have extremely low values of contrast, low values of entropy, and very large values of correlation.Finally, we propose that sampled high spatial resolution satellite data be used in conjunction with coarser resolution operational satellite data to detect and identify cloud field structure and directionality and to locate regions of subresolution scale cloud contamination.

Gray-scale transform and evaluation for digital x-ray chest images on CRT monitor

NASA Astrophysics Data System (ADS)

Furukawa, Isao; Suzuki, Junji; Ono, Sadayasu; Kitamura, Masayuki; Ando, Yutaka

1997-04-01

In this paper, an experimental evaluation of a super high definition (SHD) imaging system for digital x-ray chest images is presented. The SHD imaging system is proposed as a platform for integrating conventional image media. We are involved in the use of SHD images in the total digitizing of medical records that include chest x-rays and pathological microscopic images, both which demand the highest level of quality among the various types of medical images. SHD images use progressive scanning and have a spatial resolution of 2000 by 2000 pixels or more and a temporal resolution (frame rate) of 60 frames/sec or more. For displaying medical x-ray images on a CRT, we derived gray scale transform characteristics based on radiologists' comments during the experiment, and elucidated the relationship between that gray scale transform and the linearization transform for maintaining the linear relationship with the luminance of film on a light box (luminance linear transform). We then carried out viewing experiments based on a five-stage evaluation. Nine radiologists participated in our experiment, and the ten cases evaluated included pulmonary fibrosis, lung cancer, and pneumonia. The experimental results indicated that conventional film images and those on super high definition CRT monitors have nearly the same quality. They also show that the gray scale transform for CRT images decided according to radiologists' comments agrees with the luminance linear transform in the high luminance region. And in the low luminance region, it was found that the gray scale transform had the characteristics of level expansion to increase the number of levels that can be expressed.

Automatic vehicle counting using background subtraction method on gray scale images and morphology operation

NASA Astrophysics Data System (ADS)

Adi, K.; Widodo, A. P.; Widodo, C. E.; Pamungkas, A.; Putranto, A. B.

2018-05-01

Traffic monitoring on road needs to be done, the counting of the number of vehicles passing the road is necessary. It is more emphasized for highway transportation management in order to prevent efforts. Therefore, it is necessary to develop a system that is able to counting the number of vehicles automatically. Video processing method is able to counting the number of vehicles automatically. This research has development a system of vehicle counting on toll road. This system includes processes of video acquisition, frame extraction, and image processing for each frame. Video acquisition is conducted in the morning, at noon, in the afternoon, and in the evening. This system employs of background subtraction and morphology methods on gray scale images for vehicle counting. The best vehicle counting results were obtained in the morning with a counting accuracy of 86.36 %, whereas the lowest accuracy was in the evening, at 21.43 %. Differences in morning and evening results are caused by different illumination in the morning and evening. This will cause the values in the image pixels to be different.

On 3-gauge transformations, 3-curvatures, and Gray-categories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Wei, E-mail: wwang@zju.edu.cn

In the 3-gauge theory, a 3-connection is given by a 1-form A valued in the Lie algebra g, a 2-form B valued in the Lie algebra h, and a 3-form C valued in the Lie algebra l, where (g,h,l) constitutes a differential 2-crossed module. We give the 3-gauge transformations from one 3-connection to another, and show the transformation formulae of the 1-curvature 2-form, the 2-curvature 3-form, and the 3-curvature 4-form. The gauge configurations can be interpreted as smooth Gray-functors between two Gray 3-groupoids: the path 3-groupoid P{sub 3}(X) and the 3-gauge group G{sup L} associated to the 2-crossed module L,more » whose differential is (g,h,l). The derivatives of Gray-functors are 3-connections, and the derivatives of lax-natural transformations between two such Gray-functors are 3-gauge transformations. We give the 3-dimensional holonomy, the lattice version of the 3-curvature, whose derivative gives the 3-curvature 4-form. The covariance of 3-curvatures easily follows from this construction. This Gray-categorical construction explains why 3-gauge transformations and 3-curvatures have the given forms. The interchanging 3-arrows are responsible for the appearance of terms with the Peiffer commutator (, )« less

Least-squares model-based halftoning

NASA Astrophysics Data System (ADS)

Pappas, Thrasyvoulos N.; Neuhoff, David L.

1992-08-01

A least-squares model-based approach to digital halftoning is proposed. It exploits both a printer model and a model for visual perception. It attempts to produce an 'optimal' halftoned reproduction, by minimizing the squared error between the response of the cascade of the printer and visual models to the binary image and the response of the visual model to the original gray-scale image. Conventional methods, such as clustered ordered dither, use the properties of the eye only implicitly, and resist printer distortions at the expense of spatial and gray-scale resolution. In previous work we showed that our printer model can be used to modify error diffusion to account for printer distortions. The modified error diffusion algorithm has better spatial and gray-scale resolution than conventional techniques, but produces some well known artifacts and asymmetries because it does not make use of an explicit eye model. Least-squares model-based halftoning uses explicit eye models and relies on printer models that predict distortions and exploit them to increase, rather than decrease, both spatial and gray-scale resolution. We have shown that the one-dimensional least-squares problem, in which each row or column of the image is halftoned independently, can be implemented with the Viterbi's algorithm. Unfortunately, no closed form solution can be found in two dimensions. The two-dimensional least squares solution is obtained by iterative techniques. Experiments show that least-squares model-based halftoning produces more gray levels and better spatial resolution than conventional techniques. We also show that the least- squares approach eliminates the problems associated with error diffusion. Model-based halftoning can be especially useful in transmission of high quality documents using high fidelity gray-scale image encoders. As we have shown, in such cases halftoning can be performed at the receiver, just before printing. Apart from coding efficiency, this approach permits the halftoner to be tuned to the individual printer, whose characteristics may vary considerably from those of other printers, for example, write-black vs. write-white laser printers.

The Research of Feature Extraction Method of Liver Pathological Image Based on Multispatial Mapping and Statistical Properties

PubMed Central

Liu, Huiling; Xia, Bingbing; Yi, Dehui

2016-01-01

We propose a new feature extraction method of liver pathological image based on multispatial mapping and statistical properties. For liver pathological images of Hematein Eosin staining, the image of R and B channels can reflect the sensitivity of liver pathological images better, while the entropy space and Local Binary Pattern (LBP) space can reflect the texture features of the image better. To obtain the more comprehensive information, we map liver pathological images to the entropy space, LBP space, R space, and B space. The traditional Higher Order Local Autocorrelation Coefficients (HLAC) cannot reflect the overall information of the image, so we propose an average correction HLAC feature. We calculate the statistical properties and the average gray value of pathological images and then update the current pixel value as the absolute value of the difference between the current pixel gray value and the average gray value, which can be more sensitive to the gray value changes of pathological images. Lastly the HLAC template is used to calculate the features of the updated image. The experiment results show that the improved features of the multispatial mapping have the better classification performance for the liver cancer. PMID:27022407

Ladar range image denoising by a nonlocal probability statistics algorithm

NASA Astrophysics Data System (ADS)

Xia, Zhi-Wei; Li, Qi; Xiong, Zhi-Peng; Wang, Qi

2013-01-01

According to the characteristic of range images of coherent ladar and the basis of nonlocal means (NLM), a nonlocal probability statistics (NLPS) algorithm is proposed in this paper. The difference is that NLM performs denoising using the mean of the conditional probability distribution function (PDF) while NLPS using the maximum of the marginal PDF. In the algorithm, similar blocks are found out by the operation of block matching and form a group. Pixels in the group are analyzed by probability statistics and the gray value with maximum probability is used as the estimated value of the current pixel. The simulated range images of coherent ladar with different carrier-to-noise ratio and real range image of coherent ladar with 8 gray-scales are denoised by this algorithm, and the results are compared with those of median filter, multitemplate order mean filter, NLM, median nonlocal mean filter and its incorporation of anatomical side information, and unsupervised information-theoretic adaptive filter. The range abnormality noise and Gaussian noise in range image of coherent ladar are effectively suppressed by NLPS.

[Digital processing and evaluation of ultrasound images].

PubMed

Borchers, J; Klews, P M

1993-10-01

With the help of workstations and PCs, on-site image processing has become possible. If the images are not available in digital form the video signal has to be A/D converted. In the case of colour images the colour channels R (red), G (green) and B (blue) have to be digitized separately. "Truecolour" imaging calls for an 8 bit resolution per channel, leading to 24 bits per pixel. Out of a pool of 2(24) possible values only the relevant 128 gray values and 64 shades of red and blue respectively needed for a colour-coded ultrasound image have to be isolated. Digital images can be changed and evaluated with the help of readily available image evaluation programmes. It is mandatory that during image manipulation the gray scale and colour pixels and LUTs (Look-Up-Table) must be worked on separately. Using relatively simple LUT manipulations astonishing image improvements are possible. Application of simple mathematical operations can lead to completely new clinical results. For example, by subtracting two consecutive colour flow images in time and special LUT operations, local acceleration of blood flow can be visualized (Colour Acceleration Imaging).

Adaptive Electronic Camouflage Using Texture Synthesis

DTIC Science & Technology

2012-04-01

algorithm begins by computing the GLCMs, GIN and GOUT , of the input image (e.g., image of local environment) and output image (randomly generated...respectively. The algorithm randomly selects a pixel from the output image and cycles its gray-level through all values. For each value, GOUT is updated...The value of the selected pixel is permanently changed to the gray-level value that minimizes the error between GIN and GOUT . Without selecting a

Evaluating Cultures: The Instrumentalism, Pluralist Perfectionism, and Particularism of John Gray

ERIC Educational Resources Information Center

Johnson, Matthew Thomas

2012-01-01

In this article, Matthew Johnson examines the possibility of using elements of John Gray's work to advance a means of evaluating cultures, in order to inform the development of pluralist perfectionist forms of public policy and, in particular, educational programs. Johnson engages critically with elements of Gray's value pluralism, such as his…

Migratory behavior of eastern North Pacific gray whales tracked using a hydrophone array

PubMed Central

Helble, Tyler A.; D’Spain, Gerald L.; Weller, David W.; Wiggins, Sean M.; Hildebrand, John A.

2017-01-01

Eastern North Pacific gray whales make one of the longest annual migrations of any mammal, traveling from their summer feeding areas in the Bering and Chukchi Seas to their wintering areas in the lagoons of Baja California, Mexico. Although a significant body of knowledge on gray whale biology and behavior exists, little is known about their vocal behavior while migrating. In this study, we used a sparse hydrophone array deployed offshore of central California to investigate how gray whales behave and use sound while migrating. We detected, localized, and tracked whales for one full migration season, a first for gray whales. We verified and localized 10,644 gray whale M3 calls and grouped them into 280 tracks. Results confirm that gray whales are acoustically active while migrating and their swimming and acoustic behavior changes on daily and seasonal time scales. The seasonal timing of the calls verifies the gray whale migration timing determined using other methods such as counts conducted by visual observers. The total number of calls and the percentage of calls that were part of a track changed significantly over both seasonal and daily time scales. An average calling rate of 5.7 calls/whale/day was observed, which is significantly greater than previously reported migration calling rates. We measured a mean speed of 1.6 m/s and quantified heading, direction, and water depth where tracks were located. Mean speed and water depth remained constant between night and day, but these quantities had greater variation at night. Gray whales produce M3 calls with a root mean square source level of 156.9 dB re 1 μPa at 1 m. Quantities describing call characteristics were variable and dependent on site-specific propagation characteristics. PMID:29084266

Migratory behavior of eastern North Pacific gray whales tracked using a hydrophone array.

PubMed

Guazzo, Regina A; Helble, Tyler A; D'Spain, Gerald L; Weller, David W; Wiggins, Sean M; Hildebrand, John A

2017-01-01

Eastern North Pacific gray whales make one of the longest annual migrations of any mammal, traveling from their summer feeding areas in the Bering and Chukchi Seas to their wintering areas in the lagoons of Baja California, Mexico. Although a significant body of knowledge on gray whale biology and behavior exists, little is known about their vocal behavior while migrating. In this study, we used a sparse hydrophone array deployed offshore of central California to investigate how gray whales behave and use sound while migrating. We detected, localized, and tracked whales for one full migration season, a first for gray whales. We verified and localized 10,644 gray whale M3 calls and grouped them into 280 tracks. Results confirm that gray whales are acoustically active while migrating and their swimming and acoustic behavior changes on daily and seasonal time scales. The seasonal timing of the calls verifies the gray whale migration timing determined using other methods such as counts conducted by visual observers. The total number of calls and the percentage of calls that were part of a track changed significantly over both seasonal and daily time scales. An average calling rate of 5.7 calls/whale/day was observed, which is significantly greater than previously reported migration calling rates. We measured a mean speed of 1.6 m/s and quantified heading, direction, and water depth where tracks were located. Mean speed and water depth remained constant between night and day, but these quantities had greater variation at night. Gray whales produce M3 calls with a root mean square source level of 156.9 dB re 1 μPa at 1 m. Quantities describing call characteristics were variable and dependent on site-specific propagation characteristics.

The greenhouse effect in a gray planetary atmosphere.

NASA Technical Reports Server (NTRS)

Wildt, R.

1966-01-01

Hopf analytical solution for values of ratio of gray absorption coefficients for insolating and escaping radiation /greenhouse parameter/ assumed constant at all depths, presenting temperature distribution graphs

Histogram contrast analysis and the visual segregation of IID textures.

PubMed

Chubb, C; Econopouly, J; Landy, M S

1994-09-01

A new psychophysical methodology is introduced, histogram contrast analysis, that allows one to measure stimulus transformations, f, used by the visual system to draw distinctions between different image regions. The method involves the discrimination of images constructed by selecting texture micropatterns randomly and independently (across locations) on the basis of a given micropattern histogram. Different components of f are measured by use of different component functions to modulate the micropattern histogram until the resulting textures are discriminable. When no discrimination threshold can be obtained for a given modulating component function, a second titration technique may be used to measure the contribution of that component to f. The method includes several strong tests of its own assumptions. An example is given of the method applied to visual textures composed of small, uniform squares with randomly chosen gray levels. In particular, for a fixed mean gray level mu and a fixed gray-level variance sigma 2, histogram contrast analysis is used to establish that the class S of all textures composed of small squares with jointly independent, identically distributed gray levels with mean mu and variance sigma 2 is perceptually elementary in the following sense: there exists a single, real-valued function f S of gray level, such that two textures I and J in S are discriminable only if the average value of f S applied to the gray levels in I is significantly different from the average value of f S applied to the gray levels in J. Finally, histogram contrast analysis is used to obtain a seventh-order polynomial approximation of f S.

Technical Note: Gray tracking in medical color displays-A report of Task Group 196.

PubMed

Badano, Aldo; Wang, Joel; Boynton, Paul; Le Callet, Patrick; Cheng, Wei-Chung; Deroo, Danny; Flynn, Michael J; Matsui, Takashi; Penczek, John; Revie, Craig; Samei, Ehsan; Steven, Peter M; Swiderski, Stan; Van Hoey, Gert; Yamaguchi, Matsuhiro; Hasegawa, Mikio; Nagy, Balázs Vince

2016-07-01

The authors discuss measurement methods and instrumentation useful for the characterization of the gray tracking performance of medical color monitors for diagnostic applications. The authors define gray tracking as the variability in the chromaticity of the gray levels in a color monitor. The authors present data regarding the capability of color measurement instruments with respect to their abilities to measure a target white point corresponding to the CIE Standard Illuminant D65 at different luminance values within the grayscale palette of a medical display. The authors then discuss evidence of significant differences in performance among color measurement instruments currently available for medical physicists to perform calibrations and image quality checks for the consistent representation of color in medical displays. In addition, the authors introduce two metrics for quantifying grayscale chromaticity consistency of gray tracking. The authors' findings show that there is an order of magnitude difference in the accuracy of field and reference instruments. The gray tracking metrics quantify how close the grayscale chromaticity is to the chromaticity of the full white point (equal amounts of red, green, and blue at maximum level) or to consecutive levels (equal values for red, green, and blue), with a lower value representing an improved grayscale tracking performance. An illustrative example of how to calculate and report the gray tracking performance according to the Task Group definitions is provided. The authors' proposed methodology for characterizing the grayscale degradation in chromaticity for color monitors that can be used to establish standards and procedures aiding in the quality control testing of color displays and color measurement instrumentation.

A 1500-year record of climatic and environmental change in Elk Lake, Minnesota I: Varve thickness and gray-scale density

USGS Publications Warehouse

Dean, W.; Anderson, R.; Platt, Bradbury J.; Anderson, D.

2002-01-01

The deepest part (29.5 m) of Elk Lake, Clearwater County, northwestern Minnesota, contains a complete Holocene section that is continuously varved. The varve components are predominantly autochthonous (CaCO3, organic matter, biogenic silica, and several iron and manganese minerals), but the varves do contain a minor detrital-clastic (aluminosilicate) component that is predominantly wind-borne (eolian) and provides an important record of atmospheric conditions. Singular spectrum analysis (SSA) and wavelet analysis of varve thickness recognized significant periodicities in the multicentennial and multidecadal bands that varied in power (i.e., variable significance) and position (i.e., variable period) within the periodic bands. Persistent periodicities of about 10, 22, 40, and 90 years, and, in particular, multicentennial periodicities in varve thickness and other proxy variables are similar to those in spectra of radiocarbon production, a proxy for past solar activity. This suggests that there may be a solar control, perhaps through geomagnetic effects on atmospheric circulation. Multicentennial and multidecadal periodicities also occur in wavelet spectra of relative gray-scale density. However, gray-scale density does not appear to correlate with any of the measured proxy variables, and at this point we do not know what controlled gray scale.

Gray scale enhances display readability of bitmapped documents

NASA Astrophysics Data System (ADS)

Ostberg, Olov; Disfors, Dennis; Feng, Yingduo

1994-05-01

Bitmapped images of high resolution, say 300 dpi rastered documents, stored in the memory of a PC are at best only borderline readable on the PC's display screen (say a 72 dpi VGA monitor). Results from a series of exploratory psycho-physical experiments, using the Adobe PhotoshopR software, show that the readability can be significantly enhanced by making use of the monitor's capability to display shades of gray. It is suggested that such a gray scale adaptation module should be bundled to all software products for electronic document management. In fact, fax modems are already available in which this principle is employed, hereby making it possible to read incoming fax documents directly on the screen.

How Do Statistical Detection Methods Compare to Entropy Measures

DTIC Science & Technology

2012-08-28

October 2001. It is known as RS attack or “Reliable Detection of LSB Steganography in Grayscale and color images ”. The algorithm they use is very...precise for the detection of pseudo-aleatory LSB steganography . Its precision varies with the image but, its referential value is a 0.005 bits by...Jessica Fridrich, Miroslav Goljan, Rui Du, "Detecting LSB Steganography in Color and Gray-Scale Images ," IEEE Multimedia, vol. 8, no. 4, pp. 22-28, Oct

Forum on Alternate Assessment and "Gray Area" Assessment: A Report on the Pre-Conference Session at the National Conference on Large Scale Assessment (Snowbird, Utah, June 11-12, 1999).

ERIC Educational Resources Information Center

National Center on Educational Outcomes, Minneapolis, MN.

This report discusses the outcomes of a June 11-12, 1999, forum that addressed alternative assessments and gray areas in large-scale assessments for students with disabilities. The forum included 161 representatives from 42 state departments of education, 3 large school districts, 1 territory, and the Department of Defense Dependent Schools. Five…

Quantum watermarking scheme through Arnold scrambling and LSB steganography

NASA Astrophysics Data System (ADS)

Zhou, Ri-Gui; Hu, Wenwen; Fan, Ping

2017-09-01

Based on the NEQR of quantum images, a new quantum gray-scale image watermarking scheme is proposed through Arnold scrambling and least significant bit (LSB) steganography. The sizes of the carrier image and the watermark image are assumed to be 2n× 2n and n× n, respectively. Firstly, a classical n× n sized watermark image with 8-bit gray scale is expanded to a 2n× 2n sized image with 2-bit gray scale. Secondly, through the module of PA-MOD N, the expanded watermark image is scrambled to a meaningless image by the Arnold transform. Then, the expanded scrambled image is embedded into the carrier image by the steganography method of LSB. Finally, the time complexity analysis is given. The simulation experiment results show that our quantum circuit has lower time complexity, and the proposed watermarking scheme is superior to others.

The effects of gypsy moth infestation on gray squirrel habitat and populations

Treesearch

David E. Samuel; Rob Silvester

1991-01-01

The overall objective of this project was to determine the effects of defoliation on gray squirrel habitat. We will evaluate the existing Habitat Suitability Index (HSI) Model for gray squirrels on the University Forest and determine the effects of thinning on HSI values computed for thinned and unthinned stands. Habitat variables used in the U. S. Fish and Wildlife...

Origins of R2∗ and white matter

PubMed Central

Rudko, David A.; Klassen, L. Martyn; de Chickera, Sonali N.; Gati, Joseph S.; Dekaban, Gregory A.; Menon, Ravi S.

2014-01-01

Estimates of the apparent transverse relaxation rate () can be used to quantify important properties of biological tissue. Surprisingly, the mechanism of dependence on tissue orientation is not well understood. The primary goal of this paper was to characterize orientation dependence of in gray and white matter and relate it to independent measurements of two other susceptibility based parameters: the local Larmor frequency shift (fL) and quantitative volume magnetic susceptibility (Δχ). Through this comparative analysis we calculated scaling relations quantifying (reversible contribution to the transverse relaxation rate from local field inhomogeneities) in a voxel given measurements of the local Larmor frequency shift. is a measure of both perturber geometry and density and is related to tissue microstructure. Additionally, two methods (the Generalized Lorentzian model and iterative dipole inversion) for calculating Δχ were compared in gray and white matter. The value of Δχ derived from fitting the Generalized Lorentzian model was then connected to the observed orientation dependence using image-registered optical density measurements from histochemical staining. Our results demonstrate that the and fL of white and cortical gray matter are well described by a sinusoidal dependence on the orientation of the tissue and a linear dependence on the volume fraction of myelin in the tissue. In deep brain gray matter structures, where there is no obvious symmetry axis, and fL have no orientation dependence but retain a linear dependence on tissue iron concentration and hence Δχ. PMID:24374633

Three-temperature plasma shock solutions with gray radiation diffusion

DOE PAGES

Johnson, Bryan M.; Klein, Richard I.

2016-04-19

Here we discuss the effects of radiation on the structure of shocks in a fully ionized plasma are investigated by solving the steady-state fluid equations for ions, electrons, and radiation. The electrons and ions are assumed to have the same bulk velocity but separate temperatures, and the radiation is modeled with the gray diffusion approximation. Both electron and ion conduction are included, as well as ion viscosity. When the material is optically thin, three-temperature behavior occurs. When the diffusive flux of radiation is important but radiation pressure is not, two-temperature behavior occurs, with the electrons strongly coupled to the radiation.more » Since the radiation heats the electrons on length scales that are much longer than the electron–ion Coulomb coupling length scale, these solutions resemble radiative shock solutions rather than plasma shock solutions that neglect radiation. When radiation pressure is important, all three components are strongly coupled. Results with constant values for the transport and coupling coefficients are compared to a full numerical simulation with a good match between the two, demonstrating that steady shock solutions constitute a straightforward and comprehensive verification test methodology for multi-physics numerical algorithms.« less

Descriptive statistics and spatial distributions of geochemical variables associated with manganese oxide-rich phases in the northern Pacific

USGS Publications Warehouse

Botbol, Joseph Moses; Evenden, Gerald Ian

1989-01-01

Tables, graphs, and maps are used to portray the frequency characteristics and spatial distribution of manganese oxide-rich phase geochemical data, to characterize the northern Pacific in terms of publicly available nodule geochemical data, and to develop data portrayal methods that will facilitate data analysis. Source data are a subset of the Scripps Institute of Oceanography's Sediment Data Bank. The study area is bounded by 0° N., 40° N., 120° E., and 100° W. and is arbitrarily subdivided into 14-20°x20° geographic subregions. Frequency distributions of trace metals characterized in the original raw data are graphed as ogives, and salient parameters are tabulated. All variables are transformed to enrichment values relative to median concentration within their host subregions. Scatter plots of all pairs of original variables and their enrichment transforms are provided as an aid to the interpretation of correlations between variables. Gridded spatial distributions of all variables are portrayed as gray-scale maps. The use of tables and graphs to portray frequency statistics and gray-scale maps to portray spatial distributions is an effective way to prepare for and facilitate multivariate data analysis.

Three-temperature plasma shock solutions with gray radiation diffusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Bryan M.; Klein, Richard I.

Here we discuss the effects of radiation on the structure of shocks in a fully ionized plasma are investigated by solving the steady-state fluid equations for ions, electrons, and radiation. The electrons and ions are assumed to have the same bulk velocity but separate temperatures, and the radiation is modeled with the gray diffusion approximation. Both electron and ion conduction are included, as well as ion viscosity. When the material is optically thin, three-temperature behavior occurs. When the diffusive flux of radiation is important but radiation pressure is not, two-temperature behavior occurs, with the electrons strongly coupled to the radiation.more » Since the radiation heats the electrons on length scales that are much longer than the electron–ion Coulomb coupling length scale, these solutions resemble radiative shock solutions rather than plasma shock solutions that neglect radiation. When radiation pressure is important, all three components are strongly coupled. Results with constant values for the transport and coupling coefficients are compared to a full numerical simulation with a good match between the two, demonstrating that steady shock solutions constitute a straightforward and comprehensive verification test methodology for multi-physics numerical algorithms.« less

Exact Thermal Transport Properties of Gray-Arsenic using Electon-Phonon Coupling

NASA Astrophysics Data System (ADS)

Kang, Seoung-Hun; Kwon, Young-Kyun

Using various theoretical methods, we investigate the thermoelectric property of gray arsenic. Thermoelectric devices that utilize the Seebeck effect convert heat flow into electrical energy. The conversion efficiency of such a device is determined by its figure of merit or ZT value, which is related to various transport coefficients, such as Seebeck coefficient and the ratio of its electrical conductivity to its thermal counterpart for given temperature. To calculate various transport coefficients and thus the ZT values of gray arsenic, we apply the Boltzmann transport theory to its electronic and phononic structures obtained by density functional theory and density functional perturbation theory together with maximally locallized Wannier functions. During this procedure, we evaluate its relaxation time accurately by explicitly considering electron-phonon coupling. Our result reveals that gray arsenic may be used for a good p-type thermoelectric devices.

Cognitive Implications of Deep Gray Matter Iron in Multiple Sclerosis.

PubMed

Fujiwara, E; Kmech, J A; Cobzas, D; Sun, H; Seres, P; Blevins, G; Wilman, A H

2017-05-01

Deep gray matter iron accumulation is increasingly recognized in association with multiple sclerosis and can be measured in vivo with MR imaging. The cognitive implications of this pathology are not well-understood, especially vis-à-vis deep gray matter atrophy. Our aim was to investigate the relationships between cognition and deep gray matter iron in MS by using 2 MR imaging-based iron-susceptibility measures. Forty patients with multiple sclerosis (relapsing-remitting, n = 16; progressive, n = 24) and 27 healthy controls were imaged at 4.7T by using the transverse relaxation rate and quantitative susceptibility mapping. The transverse relaxation rate and quantitative susceptibility mapping values and volumes (atrophy) of the caudate, putamen, globus pallidus, and thalamus were determined by multiatlas segmentation. Cognition was assessed with the Brief Repeatable Battery of Neuropsychological Tests. Relationships between cognition and deep gray matter iron were examined by hierarchic regressions. Compared with controls, patients showed reduced memory ( P < .001) and processing speed ( P = .02) and smaller putamen ( P < .001), globus pallidus ( P = .002), and thalamic volumes ( P < .001). Quantitative susceptibility mapping values were increased in patients compared with controls in the putamen ( P = .003) and globus pallidus ( P = .003). In patients only, thalamus ( P < .001) and putamen ( P = .04) volumes were related to cognitive performance. After we controlled for volume effects, quantitative susceptibility mapping values in the globus pallidus ( P = .03; trend for transverse relaxation rate, P = .10) were still related to cognition. Quantitative susceptibility mapping was more sensitive compared with the transverse relaxation rate in detecting deep gray matter iron accumulation in the current multiple sclerosis cohort. Atrophy and iron accumulation in deep gray matter both have negative but separable relationships to cognition in multiple sclerosis. © 2017 by American Journal of Neuroradiology.

Effect of Heating Time on Hardness Properties of Laser Clad Gray Cast Iron Surface

NASA Astrophysics Data System (ADS)

Norhafzan, B.; Aqida, S. N.; Mifthal, F.; Zulhishamuddin, A. R.; Ismail, I.

2018-03-01

This paper presents effect of heating time on cladded gray cast iron. In this study, the effect of heating time on cladded gray cast iron and melted gray cast iron were analysed. The gray cast iron sample were added with mixed Mo-Cr powder using laser cladding technique. The mixed Mo and Cr powder was pre-placed on gray cast iron surface. Modified layer were sectioned using diamond blade cutter and polish using SiC abrasive paper before heated. Sample was heated in furnace for 15, 30 and 45 minutes at 650 °C and cool down in room temperature. Metallographic study was conduct using inverted microscope while surface hardness properties were tested using Wilson hardness test with Vickers scale. Results for metallographic study showed graphite flakes within matrix of pearlite. The surface hardness for modified layer decreased when increased heating time process. These findings are significant to structure stability of laser cladded gray cast iron with different heating times.

Added value of high-b-value (b = 3000 s/mm2) diffusion-weighted imaging at 3 T in relation to fluid-attenuated inversion recovery images for the evaluation of cortical lesions in inflammatory brain diseases.

PubMed

Iwashita, Koya; Hirai, Toshinori; Kitajima, Mika; Shigematsu, Yoshinori; Uetani, Hiroyuki; Iryo, Yasuhiko; Azuma, Minako; Hayashida, Eri; Ando, Yukio; Murakami, Ryuji; Yamashita, Yasuyuki

2013-01-01

The purpose of this study was to determine how the gray-to-white matter contrast in healthy subjects changes on high-b-value diffusion-weighted imaging (DWI) acquired at 3 T and evaluate whether high-b-value DWI at 3 T is useful for the detection of cortical lesions in inflammatory brain diseases. Ten healthy volunteers underwent DWI at b = 1000, 2000, 3000, 4000, and 5000 s/mm(2) on a 3-T MRI unit. On DW images, 1 radiologist performed region-of-interest measurements of the signal intensity of 8 gray matter structures. The gray-to-white matter contrast ratio (GWCR) was calculated. Ten patients with inflammatory cortical lesions were also included. All patients underwent conventional MRI and DWI at b = 1000 and 3000 s/mm(2). Using a 4-point grading system, 2 radiologists independently assessed the presence of additional information on DW images compared with fluid-attenuated inversion recovery images. Interobserver agreement was assessed by κ statistics. In the healthy subjects, the b value increased as the GWCR decreased in all evaluated gray matter structures. On DW images acquired at b = 3000 s/mm(2), mean GWCR was less than 1.0 in 7 of 8 structures. For both reviewers, DWI at b = 3000 s/mm(2) yielded significantly more additional information than did DWI at b = 1000 s/mm(2) (P < 0.05). Interobserver agreement for DWI at b = 1000 s/mm(2) and b = 3000 s/mm(2) was fair (κ = 0.35) and excellent (κ = 1.0), respectively. At 3-T DWI, the gray-to-white matter contrast in most gray matter structures reverses at b = 3000 s/mm. In the evaluation of cortical lesions in patients with inflammatory brain diseases, 3-T DWI at b = 3000 s/mm was more useful than b = 1000 s/mm(2).

Histogram and gray level co-occurrence matrix on gray-scale ultrasound images for diagnosing lymphocytic thyroiditis.

PubMed

Shin, Young Gyung; Yoo, Jaeheung; Kwon, Hyeong Ju; Hong, Jung Hwa; Lee, Hye Sun; Yoon, Jung Hyun; Kim, Eun-Kyung; Moon, Hee Jung; Han, Kyunghwa; Kwak, Jin Young

2016-08-01

The objective of the study was to evaluate whether texture analysis using histogram and gray level co-occurrence matrix (GLCM) parameters can help clinicians diagnose lymphocytic thyroiditis (LT) and differentiate LT according to pathologic grade. The background thyroid pathology of 441 patients was classified into no evidence of LT, chronic LT (CLT), and Hashimoto's thyroiditis (HT). Histogram and GLCM parameters were extracted from the regions of interest on ultrasound. The diagnostic performances of the parameters for diagnosing and differentiating LT were calculated. Of the histogram and GLCM parameters, the mean on histogram had the highest Az (0.63) and VUS (0.303). As the degrees of LT increased, the mean decreased and the standard deviation and entropy increased. The mean on histogram from gray-scale ultrasound showed the best diagnostic performance as a single parameter in differentiating LT according to pathologic grade as well as in diagnosing LT. Copyright © 2016 Elsevier Ltd. All rights reserved.

Age Estimation Based on Appearance of Gray Hair in Different Body Sites of Sri Lankan Autopsy Cases.

PubMed

Senanayake, Harshana Mahendra Kumara; Wickramasinghe, Nuwan Darshana

2017-07-01

Owing to the scanty evidence on usefulness of information of appearance of gray hair for age estimation, this study was conducted to estimate age based on the appearance of gray hair on different body sites in a sample of autopsy cases in Sri Lanka. A descriptive cross-sectional study was conducted in Teaching Hospital-Kurunegala during 2011 to 2013. Based on the pattern of the presence of gray hair in different body sites, six stages of gray hair were computed. The analysis 1155 autopsy cases revealed strong, positive correlations between age and appearance of gray hair in head, mustache, beard, and pubic area among males and strong, positive correlations between age and the appearance of gray hair in head and pubic area among females (p < 0.01). Our findings demonstrate the value of information of appearance of gray hair for age estimation in the field of forensic science. © 2016 American Academy of Forensic Sciences.

Gray Matter Network Disruptions and Regional Amyloid Beta in Cognitively Normal Adults.

PubMed

Ten Kate, Mara; Visser, Pieter Jelle; Bakardjian, Hovagim; Barkhof, Frederik; Sikkes, Sietske A M; van der Flier, Wiesje M; Scheltens, Philip; Hampel, Harald; Habert, Marie-Odile; Dubois, Bruno; Tijms, Betty M

2018-01-01

The accumulation of amyloid plaques is one of the earliest pathological changes in Alzheimer's disease (AD) and may occur 20 years before the onset of symptoms. Examining associations between amyloid pathology and other early brain changes is critical for understanding the pathophysiological underpinnings of AD. Alterations in gray matter networks might already start at early preclinical stages of AD. In this study, we examined the regional relationship between amyloid aggregation measured with positron emission tomography (PET) and gray matter network measures in elderly subjects with subjective memory complaints. Single-subject gray matter networks were extracted from T1-weigthed structural MRI in cognitively normal subjects ( n = 318, mean age 76.1 ± 3.5, 64% female, 28% amyloid positive). Degree, clustering, path length and small world properties were computed. Global and regional amyloid load was determined using [ 18 F]-Florbetapir PET. Associations between standardized uptake value ratio (SUVr) values and network measures were examined using linear regression models. We found that higher global SUVr was associated with lower clustering ( β = -0.12, p < 0.05), and small world values ( β = -0.16, p < 0.01). Associations were most prominent in orbito- and dorsolateral frontal and parieto-occipital regions. Local SUVr values showed less anatomical variability and did not convey additional information beyond global amyloid burden. In conclusion, we found that in cognitively normal elderly subjects, increased global amyloid pathology is associated with alterations in gray matter networks that are indicative of incipient network breakdown towards AD dementia.

Three-dimensional contour edge detection algorithm

NASA Astrophysics Data System (ADS)

Wang, Yizhou; Ong, Sim Heng; Kassim, Ashraf A.; Foong, Kelvin W. C.

2000-06-01

This paper presents a novel algorithm for automatically extracting 3D contour edges, which are points of maximum surface curvature in a surface range image. The 3D image data are represented as a surface polygon mesh. The algorithm transforms the range data, obtained by scanning a dental plaster cast, into a 2D gray scale image by linearly converting the z-value of each vertex to a gray value. The Canny operator is applied to the median-filtered image to obtain the edge pixels and their orientations. A vertex in the 3D object corresponding to the detected edge pixel and its neighbors in the direction of the edge gradient are further analyzed with respect to their n-curvatures to extract the real 3D contour edges. This algorithm provides a fast method of reducing and sorting the unwieldy data inherent in the surface mesh representation. It employs powerful 2D algorithms to extract features from the transformed 3D models and refers to the 3D model for further analysis of selected data. This approach substantially reduces the computational burden without losing accuracy. It is also easily extended to detect 3D landmarks and other geometrical features, thus making it applicable to a wide range of applications.

Third Annual Foreign Acquisitions Workshop: Improving Access to Foreign Gray Literature

NASA Technical Reports Server (NTRS)

1993-01-01

The theme of the Third Annual Foreign Acquisitions Workshop was the acquisition of and access to foreign (non-U.S.) gray literature. Individual presentations addressed general topics related to the value and scope of gray literature, specialized and foreign gray-literature sources, intellectual property issues, and U.S. Federal Agency activities. Additional topics focused on electronic access and evaluation techniques and the current and potential uses of networking technology. The workshop papers are presented in their entirety or in abstract or outline form. Appendices include a listing of databases that include foreign gray literature, a bibliography, and a report on U.S.-Japan cooperation in the use of scientific and technical information.

CNNs flag recognition preprocessing scheme based on gray scale stretching and local binary pattern

NASA Astrophysics Data System (ADS)

Gong, Qian; Qu, Zhiyi; Hao, Kun

2017-07-01

Flag is a rather special recognition target in image recognition because of its non-rigid features with the location, scale and rotation characteristics. The location change can be handled well by the depth learning algorithm Convolutional Neural Networks (CNNs), but the scale and rotation changes are quite a challenge for CNNs. Since it has good rotation and gray scale invariance, the local binary pattern (LBP) is combined with grayscale stretching and CNNs to make LBP and grayscale stretching as CNNs pretreatment, which can not only significantly improve the efficiency of flag recognition, but can also evaluate the recognition effect through ROC, accuracy, MSE and quality factor.

Graphics-Printing Program For The HP Paintjet Printer

NASA Technical Reports Server (NTRS)

Atkins, Victor R.

1993-01-01

IMPRINT utility computer program developed to print graphics specified in raster files by use of Hewlett-Packard Paintjet(TM) color printer. Reads bit-mapped images from files on UNIX-based graphics workstation and prints out three different types of images: wire-frame images, solid-color images, and gray-scale images. Wire-frame images are in continuous tone or, in case of low resolution, in random gray scale. In case of color images, IMPRINT also prints by use of default palette of solid colors. Written in C language.

Changes in Fundus Autofluorescence after Anti-vascular Endothelial Growth Factor According to the Type of Choroidal Neovascularization in Age-related Macular Degeneration.

PubMed

Lee, Ji Young; Chung, Hyewon; Kim, Hyung Chan

2016-02-01

To describe the changes of fundus autofluorescence (FAF) in patients with age-related macular degeneration before and after intravitreal injection of anti-vascular endothelial growth factor according to the type of choroidal neovascularization (CNV) and to evaluate the correlation of FAF with spectral domain optical coherence tomography (SD-OCT) parameters and vision. This was a retrospective study. Twenty-one treatment-naïve patients with neovascular age-related macular degeneration were included. Study eyes were divided into two groups according to the type of CNV. Fourteen eyes were type 1 CNV and seven eyes were type 2 CNV. All eyes underwent a complete ophthalmologic examination, including an assessment of best-corrected visual acuity, SD-OCT, fluorescein angiography, and FAF imaging, before and 3 months after intravitreal anti-vascular endothelial growth factor injection. Gray scales of FAF image for CNV areas, delineated as in fluorescein angiography, were analyzed using the ImageJ program, which were adjusted by comparison with normal background areas. Correlation of changes in FAF with changes in SD-OCT parameters, including CNV thickness, photoreceptor inner and outer segment junction disruption length, external limiting membrane disruption length, central macular thickness, subretinal fluid, and intraretinal fluid were analyzed. Eyes with both type 1 and type 2 CNV showed reduced FAF before treatment. The mean gray scales (%) of type 1 and type 2 CNV were 52.20% and 42.55%, respectively. The background values were 106.72 and 96.86. After treatment, the mean gray scales (%) of type 1 CNV and type 2 CNV were changed to 57.61% (p = 0.005) and 57.93% (p = 0.008), respectively. After treatment, CNV thickness, central macular thickness, and inner and outer segment junction disruption length were decreased while FAF increased. FAF was noted to be reduced in eyes with newly diagnosed wet age-related macular degeneration, but increased after anti-vascular endothelial growth factor therapy regardless of CNV lesion type.

A New Approach for Deep Gray Matter Analysis Using Partial-Volume Estimation.

PubMed

Bonnier, Guillaume; Kober, Tobias; Schluep, Myriam; Du Pasquier, Renaud; Krueger, Gunnar; Meuli, Reto; Granziera, Cristina; Roche, Alexis

2016-01-01

The existence of partial volume effects in brain MR images makes it challenging to understand physio-pathological alterations underlying signal changes due to pathology across groups of healthy subjects and patients. In this study, we implement a new approach to disentangle gray and white matter alterations in the thalamus and the basal ganglia. The proposed method was applied to a cohort of early multiple sclerosis (MS) patients and healthy subjects to evaluate tissue-specific alterations related to diffuse inflammatory or neurodegenerative processes. Forty-three relapsing-remitting MS patients and nineteen healthy controls underwent 3T MRI including: (i) fluid-attenuated inversion recovery, double inversion recovery, magnetization-prepared gradient echo for lesion count, and (ii) T1 relaxometry. We applied a partial volume estimation algorithm to T1 relaxometry maps to gray and white matter local concentrations as well as T1 values characteristic of gray and white matter in the thalamus and the basal ganglia. Statistical tests were performed to compare groups in terms of both global T1 values, tissue characteristic T1 values, and tissue concentrations. Significant increases in global T1 values were observed in the thalamus (p = 0.038) and the putamen (p = 0.026) in RRMS patients compared to HC. In the Thalamus, the T1 increase was associated with a significant increase in gray matter characteristic T1 (p = 0.0016) with no significant effect in white matter. The presented methodology provides additional information to standard MR signal averaging approaches that holds promise to identify the presence and nature of diffuse pathology in neuro-inflammatory and neurodegenerative diseases.

Life-cycle Economic and Environmental Effects of Green, Gray and Hybrid Stormwater Infrastructure

NASA Astrophysics Data System (ADS)

Stokes-Draut, J. R.; Taptich, M. N.; Horvath, A.

2016-12-01

Cities throughout the U.S. are seeking efficient ways to manage stormwater for many reasons, including flood control, pollution management, water supply augmentation and to prepare for a changing climate. Traditionally, cities have relied primarily on gray infrastructure, namely sewers, storage and treatment facilities. In these systems, urban runoff, its volume increasing as impervious surfaces expand, is channeled to a wastewater plant where it is mixed with raw sewage prior to treatment or it is discharged, generally untreated, to local water bodies. These facilities are inflexible and expensive to build and maintain. Many systems are deteriorating and/or approaching, if not exceeding, their design capacity. Increasingly, more innovative approaches that integrate stormwater management into the natural environment and that make sense at both local and regional scales are sought. Identifying the best stormwater solution will require evaluating the life-cycle economic costs associated with these alternatives, including costs associated with construction, operation, and maintenance including regulatory and permitting costs, financing, as well as other indirect costs (e.g., avoided wastewater processing or system capacity expansion, increased property value) and non-economic co-benefits (i.e, aesthetics, habitat provision). Beyond conventional life-cycle costing, applying life-cycle assessment (LCA) will contribute to more holistic and sustainable decision-making. LCA can be used to quantitatively track energy use, greenhouse gas emissions, and other environmental effects associated with constructing, operating, and maintaining green and gray infrastructure, including supply chain contributions. We will present the current state of knowledge for implementing life-cycle costing and LCA into stormwater management decisions for green, gray and hybrid infrastructure.

Reproducibility of F18-FDG PET radiomic features for different cervical tumor segmentation methods, gray-level discretization, and reconstruction algorithms.

PubMed

Altazi, Baderaldeen A; Zhang, Geoffrey G; Fernandez, Daniel C; Montejo, Michael E; Hunt, Dylan; Werner, Joan; Biagioli, Matthew C; Moros, Eduardo G

2017-11-01

Site-specific investigations of the role of radiomics in cancer diagnosis and therapy are emerging. We evaluated the reproducibility of radiomic features extracted from 18 Flourine-fluorodeoxyglucose ( 18 F-FDG) PET images for three parameters: manual versus computer-aided segmentation methods, gray-level discretization, and PET image reconstruction algorithms. Our cohort consisted of pretreatment PET/CT scans from 88 cervical cancer patients. Two board-certified radiation oncologists manually segmented the metabolic tumor volume (MTV 1 and MTV 2 ) for each patient. For comparison, we used a graphical-based method to generate semiautomated segmented volumes (GBSV). To address any perturbations in radiomic feature values, we down-sampled the tumor volumes into three gray-levels: 32, 64, and 128 from the original gray-level of 256. Finally, we analyzed the effect on radiomic features on PET images of eight patients due to four PET 3D-reconstruction algorithms: maximum likelihood-ordered subset expectation maximization (OSEM) iterative reconstruction (IR) method, fourier rebinning-ML-OSEM (FOREIR), FORE-filtered back projection (FOREFBP), and 3D-Reprojection (3DRP) analytical method. We extracted 79 features from all segmentation method, gray-levels of down-sampled volumes, and PET reconstruction algorithms. The features were extracted using gray-level co-occurrence matrices (GLCM), gray-level size zone matrices (GLSZM), gray-level run-length matrices (GLRLM), neighborhood gray-tone difference matrices (NGTDM), shape-based features (SF), and intensity histogram features (IHF). We computed the Dice coefficient between each MTV and GBSV to measure segmentation accuracy. Coefficient values close to one indicate high agreement, and values close to zero indicate low agreement. We evaluated the effect on radiomic features by calculating the mean percentage differences (d¯) between feature values measured from each pair of parameter elements (i.e. segmentation methods: MTV 1 -MTV 2 , MTV 1 -GBSV, MTV 2 -GBSV; gray-levels: 64-32, 64-128, and 64-256; reconstruction algorithms: OSEM-FORE-OSEM, OSEM-FOREFBP, and OSEM-3DRP). We used |d¯| as a measure of radiomic feature reproducibility level, where any feature scored |d¯| ±SD ≤ |25|% ± 35% was considered reproducible. We used Bland-Altman analysis to evaluate the mean, standard deviation (SD), and upper/lower reproducibility limits (U/LRL) for radiomic features in response to variation in each testing parameter. Furthermore, we proposed U/LRL as a method to classify the level of reproducibility: High- ±1% ≤ U/LRL ≤ ±30%; Intermediate- ±30% < U/LRL ≤ ±45%; Low- ±45 < U/LRL ≤ ±50%. We considered any feature below the low level as nonreproducible (NR). Finally, we calculated the interclass correlation coefficient (ICC) to evaluate the reliability of radiomic feature measurements for each parameter. The segmented volumes of 65 patients (81.3%) scored Dice coefficient >0.75 for all three volumes. The result outcomes revealed a tendency of higher radiomic feature reproducibility among segmentation pair MTV 1 -GBSV than MTV 2 -GBSV, gray-level pairs of 64-32 and 64-128 than 64-256, and reconstruction algorithm pairs of OSEM-FOREIR and OSEM-FOREFBP than OSEM-3DRP. Although the choice of cervical tumor segmentation method, gray-level value, and reconstruction algorithm may affect radiomic features, some features were characterized by high reproducibility through all testing parameters. The number of radiomic features that showed insensitivity to variations in segmentation methods, gray-level discretization, and reconstruction algorithms was 10 (13%), 4 (5%), and 1 (1%), respectively. These results suggest that a careful analysis of the effects of these parameters is essential prior to any radiomics clinical application. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

White Matter Tract Injury is Associated with Deep Gray Matter Iron Deposition in Multiple Sclerosis.

PubMed

Bergsland, Niels; Tavazzi, Eleonora; Laganà, Maria Marcella; Baglio, Francesca; Cecconi, Pietro; Viotti, Stefano; Zivadinov, Robert; Baselli, Giuseppe; Rovaris, Marco

2017-01-01

With respect to healthy controls (HCs), increased iron concentrations in the deep gray matter (GM) and decreased white matter (WM) integrity are common findings in multiple sclerosis (MS) patients. The association between these features of the disease remains poorly understood. We investigated the relationship between deep iron deposition in the deep GM and WM injury in associated fiber tracts in MS patients. Sixty-six MS patients (mean age 50.0 years, median Expanded Disability Status Scale 5.25, mean disease duration 19.1 years) and 29 HCs, group matched for age and sex were imaged on a 1.5T scanner. Susceptibility-weighted imaging and diffusion tensor imaging (DTI) were used for assessing high-pass filtered phase values in the deep GM and normal appearing WM (NAWM) integrity in associated fiber tracts, respectively. Correlation analyses investigated the associations between filtered phase values (suggestive of iron content) and WM damage. Areas indicative of increased iron levels were found in the left and right caudates as well as in the left thalamus. MS patients presented with decreased DTI-derived measures of tissue integrity in the associated WM tracts. Greater mean, axial and radial diffusivities were associated with increased iron levels in all three GM areas (r values .393 to .514 with corresponding P values .003 to <.0001). Global NAWM diffusivity measures were not related to mean filtered phase values within the deep GM. Increased iron concentration in the deep GM is associated with decreased tissue integrity of the connected WM in MS patients. Copyright © 2016 by the American Society of Neuroimaging.

A century of guayule: Comprehensive genetic characterization of the US national guayule (Parthenium argentatum A. Gray) germplasm collection

USDA-ARS?s Scientific Manuscript database

The fragility of a single-source, geographically concentrated supply of natural rubber, a critical material of the modern economy, has brought guayule (Parthenium argentatum A. Gray) to the forefront as an alternative source of natural rubber. The improvement of guayule for commercial-scale producti...

Regional gray matter correlates of vocational interests

PubMed Central

2012-01-01

Background Previous studies have identified brain areas related to cognitive abilities and personality, respectively. In this exploratory study, we extend the application of modern neuroimaging techniques to another area of individual differences, vocational interests, and relate the results to an earlier study of cognitive abilities salient for vocations. Findings First, we examined the psychometric relationships between vocational interests and abilities in a large sample. The primary relationships between those domains were between Investigative (scientific) interests and general intelligence and between Realistic (“blue-collar”) interests and spatial ability. Then, using MRI and voxel-based morphometry, we investigated the relationships between regional gray matter volume and vocational interests. Specific clusters of gray matter were found to be correlated with Investigative and Realistic interests. Overlap analyses indicated some common brain areas between the correlates of Investigative interests and general intelligence and between the correlates of Realistic interests and spatial ability. Conclusions Two of six vocational-interest scales show substantial relationships with regional gray matter volume. The overlap between the brain correlates of these scales and cognitive-ability factors suggest there are relationships between individual differences in brain structure and vocations. PMID:22591829

Regional gray matter correlates of vocational interests.

PubMed

Schroeder, David H; Haier, Richard J; Tang, Cheuk Ying

2012-05-16

Previous studies have identified brain areas related to cognitive abilities and personality, respectively. In this exploratory study, we extend the application of modern neuroimaging techniques to another area of individual differences, vocational interests, and relate the results to an earlier study of cognitive abilities salient for vocations. First, we examined the psychometric relationships between vocational interests and abilities in a large sample. The primary relationships between those domains were between Investigative (scientific) interests and general intelligence and between Realistic ("blue-collar") interests and spatial ability. Then, using MRI and voxel-based morphometry, we investigated the relationships between regional gray matter volume and vocational interests. Specific clusters of gray matter were found to be correlated with Investigative and Realistic interests. Overlap analyses indicated some common brain areas between the correlates of Investigative interests and general intelligence and between the correlates of Realistic interests and spatial ability. Two of six vocational-interest scales show substantial relationships with regional gray matter volume. The overlap between the brain correlates of these scales and cognitive-ability factors suggest there are relationships between individual differences in brain structure and vocations.

Gray matter network measures are associated with cognitive decline in mild cognitive impairment.

PubMed

Dicks, Ellen; Tijms, Betty M; Ten Kate, Mara; Gouw, Alida A; Benedictus, Marije R; Teunissen, Charlotte E; Barkhof, Frederik; Scheltens, Philip; van der Flier, Wiesje M

2018-01-01

Gray matter networks are disrupted in Alzheimer's disease and related to cognitive impairment. However, it is still unclear whether these disruptions are associated with cognitive decline over time. Here, we studied this question in a large sample of patients with mild cognitive impairment with extensive longitudinal neuropsychological assessments. Gray matter networks were extracted from baseline structural magnetic resonance imaging, and we tested associations of network measures and cognitive decline in Mini-Mental State Examination and 5 cognitive domains (i.e., memory, attention, executive function, visuospatial, and language). Disrupted network properties were cross-sectionally related to worse cognitive impairment. Longitudinally, lower small-world coefficient values were associated with a steeper decline in almost all domains. Lower betweenness centrality values correlated with a faster decline in Mini-Mental State Examination and memory, and at a regional level, these associations were specific for the precuneus, medial frontal, and temporal cortex. Furthermore, network measures showed additive value over established biomarkers in predicting cognitive decline. Our results suggest that gray matter network measures might have use in identifying patients who will show fast disease progression. Copyright © 2017 Elsevier Inc. All rights reserved.

Characterization of Nanoporous as a Medium for Size-Selective Filtration, Preconcentration, and Detection of Biomolecules

DTIC Science & Technology

2016-07-04

dimensional patterning and morphological control of porous nanomaterials by gray -scale direct imprinting, Scientific Reports, (03 2013): 1502. doi: 10.1038...detection with the exception that a different DNA apatamer sequence was required:  5’-GAT CGG GTG TGG GTG GCG TAA AGG GAG CAT CGG ACA-3’. Figure 6b shows...nanomaterials by gray -scale direct imprinting," Sci Rep 3, 1502 (2013). 8J. D. Ryckman, M. Liscidini, J. E. Sipe, S. M. Weiss, "Porous silicon structures

Quantitative investigation of the effects of the scanning parameters in the digitization of EBT and EBT2 Gafchromic film dosimetry with flatbed scanners.

PubMed

Hu, Yida; Ahmad, Salahuddin; Ali, Imad

2012-01-01

With increasing popularity and complexity of intensity-modulated radiation therapy (IMRT) delivery modalities including regular and arc therapies, there is a growing challenge for validating the accuracy of dose distributions. Gafchromic films have superior characteristics for dose verification over other conventional dosimeters. In order to optimize the use of Gafchromic films in clinical IMRT quality assurance procedures, the scanning parameters of EBT and EBT2 films with a flatbed scanner were investigated. The effects of several parameters including scanning position, orientation, uniformity, film sensitivity and optical density (OD) growth after irradiation were quantified. The profiles of the EBT and EBT2 films had a noise level of 0.6% and 0.7%, respectively. Considerable orientation dependence was observed and the scanner value difference between landscape and portrait modes were about 12% and 10% for EBT and EBT2 films, respectively. The highest response sensitivity was observed using digitized red color images of the EBT2 film scanned with landscape mode. The total system non-uniformity composed of contributions from the film and the scanner was less than 1.7%. OD variations showed that EBT gray scale grew slower, however, reached higher growth values of 15% when compared with EBT2 gray scale which grew 12% after a long time (480 hours) post-irradiation. The EBT film using the red color channel showed the minimal growth where OD increased up to 3% within 3 days after irradiation, and took one week to stabilize.

Gray whale distribution relative to benthic invertebrate biomass and abundance: Northeastern Chukchi Sea 2009-2012

NASA Astrophysics Data System (ADS)

Brower, Amelia A.; Ferguson, Megan C.; Schonberg, Susan V.; Jewett, Stephen C.; Clarke, Janet T.

2017-10-01

The shallow continental shelf waters of the Bering and Chukchi seas are the northernmost foraging grounds of North Pacific gray whales (Eschrichtius robustus). Benthic amphipods are considered the primary prey of gray whales in these waters, although no comprehensive quantitative analysis has been performed to support this assumption. Gray whale relative abundance, distribution, and behavior in the northeastern Chukchi Sea (69°-72°N, 155-169°W) were documented during aerial surveys in June-October 2009-2012. Concurrently, vessel-based benthic infaunal sampling was conducted in the area in July-August 2009-10, September 2011, and August 2012. Gray whales were seen in the study area each month that surveys were conducted, with the majority of whales feeding. Statistical analyses confirm that the highest densities of feeding gray whales were associated with high benthic amphipod abundance, primarily within 70 km of shore from Point Barrow to Icy Cape, in water <50 m deep. Conversely, gray whales were not seen in 40-km×40-km cells containing benthic sampling stations with 85 m-2 or fewer amphipods. Continuing broad-scale aerial surveys in the Chukchi Sea and prey sampling near feeding gray whales will be an important means to monitor and document ongoing and predicted ecosystem changes.

3D measurement using combined Gray code and dual-frequency phase-shifting approach

NASA Astrophysics Data System (ADS)

Yu, Shuang; Zhang, Jing; Yu, Xiaoyang; Sun, Xiaoming; Wu, Haibin; Liu, Xin

2018-04-01

The combined Gray code and phase-shifting approach is a commonly used 3D measurement technique. In this technique, an error that equals integer multiples of the phase-shifted fringe period, i.e. period jump error, often exists in the absolute analog code, which can lead to gross measurement errors. To overcome this problem, the present paper proposes 3D measurement using a combined Gray code and dual-frequency phase-shifting approach. Based on 3D measurement using the combined Gray code and phase-shifting approach, one set of low-frequency phase-shifted fringe patterns with an odd-numbered multiple of the original phase-shifted fringe period is added. Thus, the absolute analog code measured value can be obtained by the combined Gray code and phase-shifting approach, and the low-frequency absolute analog code measured value can also be obtained by adding low-frequency phase-shifted fringe patterns. Then, the corrected absolute analog code measured value can be obtained by correcting the former by the latter, and the period jump errors can be eliminated, resulting in reliable analog code unwrapping. For the proposed approach, we established its measurement model, analyzed its measurement principle, expounded the mechanism of eliminating period jump errors by error analysis, and determined its applicable conditions. Theoretical analysis and experimental results show that the proposed approach can effectively eliminate period jump errors, reliably perform analog code unwrapping, and improve the measurement accuracy.

Doppler color imaging. Principles and instrumentation.

PubMed

Kremkau, F W

1992-01-01

DCI acquires Doppler-shifted echoes from a cross-section of tissue scanned by an ultrasound beam. These echoes are then presented in color and superimposed on the gray-scale anatomic image of non-Doppler-shifted echoes received during the scan. The flow echoes are assigned colors according to the color map chosen. Usually red, yellow, or white indicates positive Doppler shifts (approaching flow) and blue, cyan, or white indicates negative shifts (receding flow). Green is added to indicate variance (disturbed or turbulent flow). Several pulses (the number is called the ensemble length) are needed to generate a color scan line. Linear, convex, phased, and annular arrays are used to acquire the gray-scale and color-flow information. Doppler color-flow instruments are pulsed-Doppler instruments and are subject to the same limitations, such as Doppler angle dependence and aliasing, as other Doppler instruments. Color controls include gain, TGC, map selection, variance on/off, persistence, ensemble length, color/gray priority. Nyquist limit (PRF), baseline shift, wall filter, and color window angle, location, and size. Doppler color-flow instruments generally have output intensities intermediate between those of gray-scale imaging and pulsed-Doppler duplex instruments. Although there is no known risk with the use of color-flow instruments, prudent practice dictates that they be used for medical indications and with the minimum exposure time and instrument output required to obtain the needed diagnostic information.

Gray matter alterations in chronic pain: A network-oriented meta-analytic approach

PubMed Central

Cauda, Franco; Palermo, Sara; Costa, Tommaso; Torta, Riccardo; Duca, Sergio; Vercelli, Ugo; Geminiani, Giuliano; Torta, Diana M.E.

2014-01-01

Several studies have attempted to characterize morphological brain changes due to chronic pain. Although it has repeatedly been suggested that longstanding pain induces gray matter modifications, there is still some controversy surrounding the direction of the change (increase or decrease in gray matter) and the role of psychological and psychiatric comorbidities. In this study, we propose a novel, network-oriented, meta-analytic approach to characterize morphological changes in chronic pain. We used network decomposition to investigate whether different kinds of chronic pain are associated with a common or specific set of altered networks. Representational similarity techniques, network decomposition and model-based clustering were employed: i) to verify the presence of a core set of brain areas commonly modified by chronic pain; ii) to investigate the involvement of these areas in a large-scale network perspective; iii) to study the relationship between altered networks and; iv) to find out whether chronic pain targets clusters of areas. Our results showed that chronic pain causes both core and pathology-specific gray matter alterations in large-scale networks. Common alterations were observed in the prefrontal regions, in the anterior insula, cingulate cortex, basal ganglia, thalamus, periaqueductal gray, post- and pre-central gyri and inferior parietal lobule. We observed that the salience and attentional networks were targeted in a very similar way by different chronic pain pathologies. Conversely, alterations in the sensorimotor and attention circuits were differentially targeted by chronic pain pathologies. Moreover, model-based clustering revealed that chronic pain, in line with some neurodegenerative diseases, selectively targets some large-scale brain networks. Altogether these findings indicate that chronic pain can be better conceived and studied in a network perspective. PMID:24936419

[Surface electromyography signal classification using gray system theory].

PubMed

Xie, Hongbo; Ma, Congbin; Wang, Zhizhong; Huang, Hai

2004-12-01

A new method based on gray correlation was introduced to improve the identification rate in artificial limb. The electromyography (EMG) signal was first transformed into time-frequency domain by wavelet transform. Singular value decomposition (SVD) was then used to extract feature vector from the wavelet coefficient for pattern recognition. The decision was made according to the maximum gray correlation coefficient. Compared with neural network recognition, this robust method has an almost equivalent recognition rate but much lower computation costs and less training samples.

Radiopacity evaluation of Portland and MTA-based cements by digital radiographic system

PubMed Central

BORGES, Alvaro Henrique; PEDRO, Fabio Luiz Miranda; SEMANOFF-SEGUNDO, Alex; MIRANDA, Carlos Eduardo Saraiva; PÉCORA, Jesus Djalma; CRUZ FILHO, Antônio Miranda

2011-01-01

Objective The aim of the present study was to evaluate the radiopacity of Portland and MTA-based cements using the Digora TM digital radiographic system. Material and Methods The performed tests followed specification number 57 from the American National Standard Institute/American Dental Association (2000) for endodontic sealing materials. The materials were placed in 5 acrylic plates, especially designed for this experiment, along with a graduated aluminum stepwedge varying from 1 to 10 mm in thickness. The set was radiographed at a 30 cm focus-object distance and with 0.2 s exposure time. After the radiographs were taken, the optical laser readings of radiographs were performed by Digora TM system. Five radiographic density readings were performed for each studied material and for each step of the aluminum scale. Results White ProRoot MTA (155.99±8.04), gray ProRoot MTA (155.96±16.30) and MTA BIO (143.13±16.94) presented higher radiopacity values (p<0.05), while white non-structural Portland (119.76±22.34), gray Portland (109.71±4.90) and white structural Portland (99.59±12.88) presented lower radiopacity values (p<0.05). Conclusions It was concluded that MTA-based cements were the only materials presenting radiopacity within the ANSI/ADA specifications. PMID:21625738

Radiopacity evaluation of Portland and MTA-based cements by digital radiographic system.

PubMed

Borges, Alvaro Henrique; Pedro, Fabio Luiz Miranda; Semanoff-Segundo, Alex; Miranda, Carlos Eduardo Saraiva; Pécora, Jesus Djalma; Cruz Filho, Antônio Miranda

2011-01-01

The aim of the present study was to evaluate the radiopacity of Portland and MTA-based cements using the Digora TM digital radiographic system. The performed tests followed specification number 57 from the American National Standard Institute/American Dental Association (2000) for endodontic sealing materials. The materials were placed in 5 acrylic plates, especially designed for this experiment, along with a graduated aluminum stepwedge varying from 1 to 10 mm in thickness. The set was radiographed at a 30 cm focus-object distance and with 0.2 s exposure time. After the radiographs were taken, the optical laser readings of radiographs were performed by Digora TM system. Five radiographic density readings were performed for each studied material and for each step of the aluminum scale. White ProRoot MTA (155.99±8.04), gray ProRoot MTA (155.96±16.30) and MTA BIO (143.13±16.94) presented higher radiopacity values (p<0.05), while white non-structural Portland (119.76±22.34), gray Portland (109.71±4.90) and white structural Portland (99.59±12.88) presented lower radiopacity values (p<0.05). It was concluded that MTA-based cements were the only materials presenting radiopacity within the ANSI/ADA specifications.

An index of beam hardening artifact for two-dimensional cone-beam CT tomographic images: establishment and preliminary evaluation

NASA Astrophysics Data System (ADS)

Yuan, Fusong; Lv, Peijun; Yang, Huifang; Wang, Yong; Sun, Yuchun

2015-07-01

Objectives: Based on the pixel gray value measurements, establish a beam-hardening artifacts index of the cone-beam CT tomographic image, and preliminarily evaluate its applicability. Methods: The 5mm-diameter metal ball and resin ball were fixed on the light-cured resin base plate respectively, while four vitro molars were fixed above and below the ball, on the left and right respectively, which have 10mm distance with the metal ball. Then, cone beam CT was used to scan the fixed base plate twice. The same layer tomographic images were selected from the two data and imported into the Photoshop software. The circle boundary was built through the determination of the center and radius of the circle, according to the artifact-free images section. Grayscale measurement tools were used to measure the internal boundary gray value G0, gray value G1 and G2 of 1mm and 20mm artifacts outside the circular boundary, the length L1 of the arc with artifacts in the circular boundary, the circumference L2. Hardening artifacts index was set A = (G1 / G0) * 0.5 + (G2 / G1) * 0.4 + (L2 / L1) * 0.1. Then, the A values of metal and resin materials were calculated respectively. Results: The A value of cobalt-chromium alloy material is 1, and resin material is 0. Conclusion: The A value reflects comprehensively the three factors of hardening artifacts influencing normal oral tissue image sharpness of cone beam CT. The three factors include relative gray value, the decay rate and range of artifacts.

Image matching for digital close-range stereo photogrammetry based on constraints of Delaunay triangulated network and epipolar-line

NASA Astrophysics Data System (ADS)

Zhang, K.; Sheng, Y. H.; Li, Y. Q.; Han, B.; Liang, Ch.; Sha, W.

2006-10-01

In the field of digital photogrammetry and computer vision, the determination of conjugate points in a stereo image pair, referred to as "image matching," is the critical step to realize automatic surveying and recognition. Traditional matching methods encounter some problems in the digital close-range stereo photogrammetry, because the change of gray-scale or texture is not obvious in the close-range stereo images. The main shortcoming of traditional matching methods is that geometric information of matching points is not fully used, which will lead to wrong matching results in regions with poor texture. To fully use the geometry and gray-scale information, a new stereo image matching algorithm is proposed in this paper considering the characteristics of digital close-range photogrammetry. Compared with the traditional matching method, the new algorithm has three improvements on image matching. Firstly, shape factor, fuzzy maths and gray-scale projection are introduced into the design of synthetical matching measure. Secondly, the topology connecting relations of matching points in Delaunay triangulated network and epipolar-line are used to decide matching order and narrow the searching scope of conjugate point of the matching point. Lastly, the theory of parameter adjustment with constraint is introduced into least square image matching to carry out subpixel level matching under epipolar-line constraint. The new algorithm is applied to actual stereo images of a building taken by digital close-range photogrammetric system. The experimental result shows that the algorithm has a higher matching speed and matching accuracy than pyramid image matching algorithm based on gray-scale correlation.

Fast algorithm of low power image reformation for OLED display

NASA Astrophysics Data System (ADS)

Lee, Myungwoo; Kim, Taewhan

2014-04-01

We propose a fast algorithm of low-power image reformation for organic light-emitting diode (OLED) display. The proposed algorithm scales the image histogram in a way to reduce power consumption in OLED display by remapping the gray levels of the pixels in the image based on the fast analysis of the histogram of the input image while maintaining contrast of the image. The key idea is that a large number of gray levels are never used in the images and these gray levels can be effectively exploited to reduce power consumption. On the other hand, to maintain the image contrast the gray level remapping is performed by taking into account the object size in the image to which each gray level is applied, that is, reforming little for the gray levels in the objects of large size. Through experiments with 24 Kodak images, it is shown that our proposed algorithm is able to reduce the power consumption by 10% even with 9% contrast enhancement. Our algorithm runs in a linear time so that it can be applied to moving pictures with high resolution.

Brain volume change and cognitive trajectories in aging.

PubMed

Fletcher, Evan; Gavett, Brandon; Harvey, Danielle; Farias, Sarah Tomaszewski; Olichney, John; Beckett, Laurel; DeCarli, Charles; Mungas, Dan

2018-05-01

Examine how longitudinal cognitive trajectories relate to brain baseline measures and change in lobar volumes in a racially/ethnically and cognitively diverse sample of older adults. Participants were 460 older adults enrolled in a longitudinal aging study. Cognitive outcomes were measures of episodic memory, semantic memory, executive function, and spatial ability derived from the Spanish and English Neuropsychological Assessment Scales (SENAS). Latent variable multilevel modeling of the four cognitive outcomes as parallel longitudinal processes identified intercepts for each outcome and a second order global change factor explaining covariance among the highly correlated slopes. We examined how baseline brain volumes (lobar gray matter, hippocampus, and white matter hyperintensity) and change in brain volumes (lobar gray matter) were associated with cognitive intercepts and global cognitive change. Lobar volumes were dissociated into global and specific components using latent variable methods. Cognitive change was most strongly associated with brain gray matter volume change, with strong independent effects of global gray matter change and specific temporal lobe gray matter change. Baseline white matter hyperintensity and hippocampal volumes had significant incremental effects on cognitive decline beyond gray matter change. Baseline lobar gray matter was related to cognitive decline, but did not contribute beyond gray matter change. Cognitive decline was strongly influenced by gray matter volume change and, especially, temporal lobe change. The strong influence of temporal lobe gray matter change on cognitive decline may reflect involvement of temporal lobe structures that are critical for late life cognitive health but also are vulnerable to diseases of aging. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Gray matter network disruptions and amyloid beta in cognitively normal adults.

PubMed

Tijms, Betty M; Kate, Mara Ten; Wink, Alle Meije; Visser, Pieter Jelle; Ecay, Mirian; Clerigue, Montserrat; Estanga, Ainara; Garcia Sebastian, Maite; Izagirre, Andrea; Villanua, Jorge; Martinez Lage, Pablo; van der Flier, Wiesje M; Scheltens, Philip; Sanz Arigita, Ernesto; Barkhof, Frederik

2016-01-01

Gray matter networks are disrupted in Alzheimer's disease (AD). It is unclear when these disruptions start during the development of AD. Amyloid beta 1-42 (Aβ42) is among the earliest changes in AD. We studied, in cognitively healthy adults, the relationship between Aβ42 levels in cerebrospinal fluid (CSF) and single-subject cortical gray matter network measures. Single-subject gray matter networks were extracted from structural magnetic resonance imaging scans in a sample of cognitively healthy adults (N = 185; age range 39-79, mini-mental state examination >25, N = 12 showed abnormal Aβ42 < 550 pg/mL). Degree, clustering coefficient, and path length were computed at whole brain level and for 90 anatomical areas. Associations between continuous Aβ42 CSF levels and single-subject cortical gray matter network measures were tested. Smoothing splines were used to determine whether a linear or nonlinear relationship gave a better fit to the data. Lower Aβ42 CSF levels were linearly associated at whole brain level with lower connectivity density, and nonlinearly with lower clustering values and higher path length values, which is indicative of a less-efficient network organization. These relationships were specific to medial temporal areas, precuneus, and the middle frontal gyrus (all p < 0.05). These results suggest that mostly within the normal spectrum of amyloid, lower Aβ42 levels can be related to gray matter networks disruptions. Copyright © 2016 Elsevier Inc. All rights reserved.

Computed gray levels in multislice and cone-beam computed tomography.

PubMed

Azeredo, Fabiane; de Menezes, Luciane Macedo; Enciso, Reyes; Weissheimer, Andre; de Oliveira, Rogério Belle

2013-07-01

Gray level is the range of shades of gray in the pixels, representing the x-ray attenuation coefficient that allows for tissue density assessments in computed tomography (CT). An in-vitro study was performed to investigate the relationship between computed gray levels in 3 cone-beam CT (CBCT) scanners and 1 multislice spiral CT device using 5 software programs. Six materials (air, water, wax, acrylic, plaster, and gutta-percha) were scanned with the CBCT and CT scanners, and the computed gray levels for each material at predetermined points were measured with OsiriX Medical Imaging software (Geneva, Switzerland), OnDemand3D (CyberMed International, Seoul, Korea), E-Film (Merge Healthcare, Milwaukee, Wis), Dolphin Imaging (Dolphin Imaging & Management Solutions, Chatsworth, Calif), and InVivo Dental Software (Anatomage, San Jose, Calif). The repeatability of these measurements was calculated with intraclass correlation coefficients, and the gray levels were averaged to represent each material. Repeated analysis of variance tests were used to assess the differences in gray levels among scanners and materials. There were no differences in mean gray levels with the different software programs. There were significant differences in gray levels between scanners for each material evaluated (P <0.001). The software programs were reliable and had no influence on the CT and CBCT gray level measurements. However, the gray levels might have discrepancies when different CT and CBCT scanners are used. Therefore, caution is essential when interpreting or evaluating CBCT images because of the significant differences in gray levels between different CBCT scanners, and between CBCT and CT values. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Decreased gray matter volume in the left hippocampus and bilateral calcarine cortex in coal mine flood disaster survivors with recent onset PTSD.

PubMed

Zhang, Jian; Tan, Qingrong; Yin, Hong; Zhang, Xiaoliang; Huan, Yi; Tang, Lihua; Wang, Huaihai; Xu, Junqing; Li, Lingjiang

2011-05-31

Although limbic structure changes have been found in chronic and recent onset post-traumatic stress disorder (PTSD) patients, there are few studies about brain structure changes in recent onset PTSD patients after a single extreme and prolonged trauma. In the current study, 20 coal mine flood disaster survivors underwent magnetic resonance imaging (MRI). Voxel-based morphometry (VBM) and region of interest (ROI) techniques were used to detect the gray matter and white matter volume changes in 10 survivors with recent onset PTSD and 10 survivors without PTSD. The correlation between the Clinician-Administered PTSD Scale (CAPS) and gray matter density in the ROI was also studied. Compared with survivors without PTSD, survivors with PTSD had significantly decreased gray matter volume and density in left anterior hippocampus, left parahippocampal gyrus, and bilateral calcarine cortex. The CAPS score correlated negatively with the gray matter density in bilateral calcarine cortex and left hippocampus in coal mine disaster survivors. Our study suggests that the gray matter volume and density of limbic structure decreased in recent onset PTSD patients who were exposed to extreme trauma. PTSD symptom severity was associated with gray matter density in calcarine cortex and hippocampus. 2010 Elsevier Ireland Ltd. All rights reserved.

A Large Scale (N=400) Investigation of Gray Matter Differences in Schizophrenia Using Optimized Voxel-based Morphometry

PubMed Central

Meda, Shashwath A.; Giuliani, Nicole R.; Calhoun, Vince D.; Jagannathan, Kanchana; Schretlen, David J.; Pulver, Anne; Cascella, Nicola; Keshavan, Matcheri; Kates, Wendy; Buchanan, Robert; Sharma, Tonmoy; Pearlson, Godfrey D.

2008-01-01

Background Many studies have employed voxel-based morphometry (VBM) of MRI images as an automated method of investigating cortical gray matter differences in schizophrenia. However, results from these studies vary widely, likely due to different methodological or statistical approaches. Objective To use VBM to investigate gray matter differences in schizophrenia in a sample significantly larger than any published to date, and to increase statistical power sufficiently to reveal differences missed in smaller analyses. Methods Magnetic resonance whole brain images were acquired from four geographic sites, all using the same model 1.5T scanner and software version, and combined to form a sample of 200 patients with both first episode and chronic schizophrenia and 200 healthy controls, matched for age, gender and scanner location. Gray matter concentration was assessed and compared using optimized VBM. Results Compared to the healthy controls, schizophrenia patients showed significantly less gray matter concentration in multiple cortical and subcortical regions, some previously unreported. Overall, we found lower concentrations of gray matter in regions identified in prior studies, most of which reported only subsets of the affected areas. Conclusions Gray matter differences in schizophrenia are most comprehensively elucidated using a large, diverse and representative sample. PMID:18378428

[A voxel-based morphometric analysis of brain gray matter in online game addicts].

PubMed

Weng, Chuan-bo; Qian, Ruo-bing; Fu, Xian-ming; Lin, Bin; Ji, Xue-bing; Niu, Chao-shi; Wang, Ye-han

2012-12-04

To explore the possible brain mechanism of online game addiction (OGA) in terms of brain morphology through voxel-based morphometric (VBM) analysis. Seventeen subjects with OGA and 17 age- and gender-matched healthy controls (HC group) were recruited from Department of Psychology at our hospital during February-December 2011. The internet addiction scale (IAS) was used to measure the degree of OGA tendency. Magnetic resonance imaging (MRI) scans were performed to acquire 3-dimensional T1-weighted images. And FSL 4.1 software was employed to confirm regional gray matter volume changes. For the regions where OGA subjects showed significantly different gray matter volumes from the controls, the gray matter volumes of these areas were extracted, averaged and regressed against the scores of IAS. The OGA group had lower gray matter volume in left orbitofrontal cortex (OFC), left medial prefrontal cortex (mPFC), bilateral insula (INS), left posterior cingulate cortex (PCC) and left supplementary motor area (SMA). Gray matter volumes of left OFC and bilateral INS showed a negative correlation with the scores of IAS (r = -0.65, r = -0.78, P < 0.05). Gray matter volume changes are present in online game addicts and they may be correlated with the occurrence and maintenance of OGA.

Implementation of outcomes-driven and value-based mental health care in the UK.

PubMed

Wallang, Paul; Kamath, Sanjith; Parshall, Alice; Saridar, Tahani; Shah, Mahek

2018-06-02

Health-care companies around the world face an unprecedented challenge of rising health-care costs, increasing life expectancy and escalating demand. Although national health-care budgets have increased (as a percentage of gross domestic product) health care continues to impart significant upward pressure on national expenditure, particularly in the UK ( Licchetta and Stelmach, 2016 ). Additionally a substantial funding gap will continue to grow ( Gainsbury, 2016 ). In response to this challenge a 'value' based strategy has gained momentum over the last two decades. Several pioneers of this approach (Sir Muir Gray at Oxford University, Professor Michael Porter at Harvard University and Professor Elizabeth Teisberg at Dell Medical School) emphasize the importance of organizations focusing on 'value'. Porter and Teisberg (2006) highlight the 'value equation' as obtaining the very best patient outcomes for each unit of currency spent. Gray expands on this model, describing three types of value: allocative, technical and personal ( Gray, 2011 ). Although some global health-care organizations have embraced the value-based agenda to transform acute care facilities, mental health providers have been slow to consider the benefits of this approach. This article gives a broad overview of implementing a value-based model in mental health care, the significant development resources needed, organizational issues, and finally concludes with the benefits and a vision of value-based mental health care for the future.

Adult and Organizational Learning and Policy Development in Environments of Gray

ERIC Educational Resources Information Center

Fair-Szofran, Nancy C.

2010-01-01

Adult and Organizational Learning and Policy Development in Environments of Gray The purpose of this study was to describe, analyze and provide an understanding of the values that influence state legislators' decision-making as it relates to appropriations, tuition and fees, and financial aid for public postsecondary education in Idaho. The study…

Correcting for the echo-time effect after measuring the cerebral blood flow by arterial spin labeling.

PubMed

Foucher, Jack R; Roquet, Daniel; Marrer, Corinne; Pham, Bich-Thuy; Gounot, Daniel

2011-10-01

To take into account the echo time (TE) influence on arterial spin labeling (ASL) signal when converting it in regional cerebral blood flow (rCBF). Gray matter ASL signal decrease with increasing TE as a consequence of the difference in the apparent transverse relaxation rates between labeled water in capillaries and nonlabeled water in the tissue (δR 2*). We aimed to measure ASL/rCBF changes in different parts of the brain and correct them. Fifteen participants underwent ASL measurements at TEs of 9.7-30 ms. Decreases in ASL values were localized by statistical parametric mapping. The corrections assessed were a subject-per-subject adjustment, an average δR 2* value adjustment, and a two-compartment model adjustment. rCBF decreases associated with increasing TEs were found for gray matter and were corrected using an average δR 2* value of 20 s(-1) . Conversely, for white matter, rCBF values increased with increasing TEs (δR 2* = -23 s(-1)). Our correction was as good as using a two-compartment model. However, it must be done separately for the gray and white matter rCBF values because the capillary R 2* values are, respectively, larger and smaller than those of surrounding tissues. Copyright © 2011 Wiley-Liss, Inc.

[The experimental study of captopril and valsartan on the preventing and treatment of diabetic retinopathy in diabetic mice].

PubMed

Xie, Xi-Wei; Zhao, Ping

2004-11-01

To evaluate the action of Angiotensin II (AngII) on the occurrence and development of diabetic retinopathy and the effect of captopril and valsartan on preventing and treating diabetic retinopathy. Male C57BL/KsJ db/+ mice were obtained at 3 weeks of age and maintained on diets enriched animal fat for 4 weeks. After exposure to high-fat diet for 4 weeks, mice were injected intraperitoneally with streptozotocin (STZ) 100 mg/kg body weight. After 2 weeks, nonfasting plasma glucose concentration was measured by nipping the distal part of the tail. Mice whose plasma glucose concentrations were higher than 11.1 mmol/L were selected for the study as model groups. Starting from day 2, captopril 12.5 mg/kg or valsartan 40 mg/kg was given to treatment group via the oral route After treatment for 4, 8, 12 weeks, respectively, eyeballs of mice from each group were enucleated, embedded in paraffin to make tissue sections for immunohistochemistry analysis. The instrument for computer image-analysis was used to analyze the expression of AngII and VEGF in ganglion cell layer. The analyzed indices were mean gray scale value and area density value. With increased duration of diabetes, the mean gray scale values of AngII and VEGF decreased significantly. At the same time, area density values of AngII and VEGF increased significantly. The area density values of VEGF in captopril treated-group was significantly lower than that in valsartan-treated group for the same duration. Moreover, the area density values of VEGF at 4 weeks was significantly lower than that at 8 weeks or 12 weeks. The area density value in captopril treated-group had a significant negative correlation with diabetes duration. AngII had significant positive correlation with VEGF. AngII possibly participated directly and/or indirectly in the occurrence and development of diabetic retinopathy via the upregulation the expression of VEGF. Early treatment with angiotensin-converting enzyme inhibitors (ACEi) and angiotensin 1 type receptor (AT1R) antagonists could improve diabetic retinopathy to some degree and protect the retinas. The effect of treatment with ACEi was better than that with AT1R antagonists in short term situation.

Latest generation of flat detector CT as a peri-interventional diagnostic tool: a comparative study with multidetector CT.

PubMed

Leyhe, Johanna Rosemarie; Tsogkas, Ioannis; Hesse, Amélie Carolina; Behme, Daniel; Schregel, Katharina; Papageorgiou, Ismini; Liman, Jan; Knauth, Michael; Psychogios, Marios-Nikos

2017-12-01

Flat detector CT (FDCT) has been used as a peri-interventional diagnostic tool in numerous studies with mixed results regarding image quality and detection of intracranial lesions. We compared the diagnostic aspects of the latest generation FDCT with standard multidetector CT (MDCT). 102 patients were included in our retrospective study. All patients had undergone interventional procedures. FDCT was acquired peri-interventionally and compared with postinterventional MDCT regarding depiction of ventricular/subarachnoidal spaces, detection of intracranial hemorrhage, and delineation of ischemic lesions using an ordinal scale. Ischemic lesions were quantified with the Alberta Stroke Program Early CT Scale (ASPECTS) on both examinations. Two neuroradiologists with varying grades of experience and a medical student scored the anonymized images separately, blinded to the clinical history. The two methods were of equal diagnostic value regarding evaluation of the ventricular system and the subarachnoidal spaces. Subarachnoidal, intraventricular, and parenchymal hemorrhages were detected with a sensitivity of 95%, 97%, and 100% and specificity of 97%, 100%, and 99%, respectively, using FDCT. Gray-white differentiation was feasible in the majority of FDCT scans, and ischemic lesions were detected with a sensitivity of 71% on FDCT, compared with MDCT scans. The mean difference in ASPECTS values on FDCT and MDCT was 0.5 points (95% CI 0.12 to 0.88). The latest generation of FDCT is a reliable and accurate tool for the detection of intracranial hemorrhage. Gray-white differentiation is feasible in the supratentorial region. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Texture classification using non-Euclidean Minkowski dilation

NASA Astrophysics Data System (ADS)

Florindo, Joao B.; Bruno, Odemir M.

2018-03-01

This study presents a new method to extract meaningful descriptors of gray-scale texture images using Minkowski morphological dilation based on the Lp metric. The proposed approach is motivated by the success previously achieved by Bouligand-Minkowski fractal descriptors on texture classification. In essence, such descriptors are directly derived from the morphological dilation of a three-dimensional representation of the gray-level pixels using the classical Euclidean metric. In this way, we generalize the dilation for different values of p in the Lp metric (Euclidean is a particular case when p = 2) and obtain the descriptors from the cumulated distribution of the distance transform computed over the texture image. The proposed method is compared to other state-of-the-art approaches (such as local binary patterns and textons for example) in the classification of two benchmark data sets (UIUC and Outex). The proposed descriptors outperformed all the other approaches in terms of rate of images correctly classified. The interesting results suggest the potential of these descriptors in this type of task, with a wide range of possible applications to real-world problems.

A Simple Encryption Algorithm for Quantum Color Image

NASA Astrophysics Data System (ADS)

Li, Panchi; Zhao, Ya

2017-06-01

In this paper, a simple encryption scheme for quantum color image is proposed. Firstly, a color image is transformed into a quantum superposition state by employing NEQR (novel enhanced quantum representation), where the R,G,B values of every pixel in a 24-bit RGB true color image are represented by 24 single-qubit basic states, and each value has 8 qubits. Then, these 24 qubits are respectively transformed from a basic state into a balanced superposition state by employed the controlled rotation gates. At this time, the gray-scale values of R, G, B of every pixel are in a balanced superposition of 224 multi-qubits basic states. After measuring, the whole image is an uniform white noise, which does not provide any information. Decryption is the reverse process of encryption. The experimental results on the classical computer show that the proposed encryption scheme has better security.

Spinal Cord Gray Matter Atrophy in Amyotrophic Lateral Sclerosis.

PubMed

Paquin, M-Ê; El Mendili, M M; Gros, C; Dupont, S M; Cohen-Adad, J; Pradat, P-F

2018-01-01

There is an emerging need for biomarkers to better categorize clinical phenotypes and predict progression in amyotrophic lateral sclerosis. This study aimed to quantify cervical spinal gray matter atrophy in amyotrophic lateral sclerosis and investigate its association with clinical disability at baseline and after 1 year. Twenty-nine patients with amyotrophic lateral sclerosis and 22 healthy controls were scanned with 3T MR imaging. Standard functional scale was recorded at the time of MR imaging and after 1 year. MR imaging data were processed automatically to measure the spinal cord, gray matter, and white matter cross-sectional areas. A statistical analysis assessed the difference in cross-sectional areas between patients with amyotrophic lateral sclerosis and controls, correlations between spinal cord and gray matter atrophy to clinical disability at baseline and at 1 year, and prediction of clinical disability at 1 year. Gray matter atrophy was more sensitive to discriminate patients with amyotrophic lateral sclerosis from controls ( P = .004) compared with spinal cord atrophy ( P = .02). Gray matter and spinal cord cross-sectional areas showed good correlations with clinical scores at baseline ( R = 0.56 for gray matter and R = 0.55 for spinal cord; P < .01). Prediction at 1 year with clinical scores ( R 2 = 0.54) was improved when including a combination of gray matter and white matter cross-sectional areas ( R 2 = 0.74). Although improvements over spinal cord cross-sectional areas were modest, this study suggests the potential use of gray matter cross-sectional areas as an MR imaging structural biomarker to monitor the evolution of amyotrophic lateral sclerosis. © 2018 by American Journal of Neuroradiology.

Microbial activity in the profiles of gray forest soil and chernozems

NASA Astrophysics Data System (ADS)

Susyan, E. A.; Rybyanets, D. S.; Ananyeva, N. D.

2006-08-01

Soil samples were taken from the profiles of a gray forest soil (under a forest) and southern chernozems of different textures under meadow vegetation. The microbial biomass (MB) was determined by the method of substrate-induced respiration; the basal respiration (BR) and the population density of microorganisms on nutrient media of different composition were also determined in the samples. The microbial metabolic quotient ( qCO2 = BR/MB) and the portion of microbial carbon (C mic) in C org were calculated. The MB and BR values were shown to decrease down the soil profiles. About 57% of the total MB in the entire soil profile was concentrated in the layer of 0-24 cm of the gray forest soil. The MB in the C horizon of chernozems was approximately two times lower than the MB in the A horizon of these soils. The correlation was found between the MB and the C org ( r = 0.99) and between the MB and the clay content ( r = 0.89) in the profile of the gray forest soil. The C mic/C org ratio in the gray forest soil and in the chernozems comprised 2.3-6.6 and 1.2-9.6%, respectively. The qCO2 value increased with the depth. The microbial community in the lower layers of the gray forest soil was dominated (88-96%) by oligotrophic microorganisms (grown on soil agar); in the upper 5 cm, these microorganisms comprised only 50% of the total amount of microorganisms grown on three media.

Non-gray gas radiation effect on mixed convection in lid driven square cavity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cherifi, Mohammed, E-mail: production1998@yahoo.fr; Benbrik, Abderrahmane, E-mail: abenbrik@umbb.dz; Laouar-Meftah, Siham, E-mail: laouarmeftah@gmail.com

A numerical study is performed to investigate the effect of non-gray radiation on mixed convection in a vertical two sided lid driven square cavity filled with air-H{sub 2}O-CO{sub 2} gas mixture. The vertical moving walls of the enclosure are maintained at two different but uniform temperatures. The horizontal walls are thermally insulated and considered as adiabatic walls. The governing differential equations are solved by a finite-volume method and the SIMPLE algorithm was adopted to solve the pressure–velocity coupling. The radiative transfer equation (RTE) is solved by the discrete ordinates method (DOM). The spectral line weighted sum of gray gases modelmore » (SLW) is used to account for non-gray radiation properties. Simulations are performed in configurations where thermal and shear forces induce cooperating buoyancy forces. Streamlines, isotherms, and Nusselt number are analyzed for three different values of Richardson’s number (from 0.1 to 10) and by considering three different medium (transparent medium, gray medium using the Planck mean absorption coefficient, and non-gray medium assumption).« less

QR code based noise-free optical encryption and decryption of a gray scale image

NASA Astrophysics Data System (ADS)

Jiao, Shuming; Zou, Wenbin; Li, Xia

2017-03-01

In optical encryption systems, speckle noise is one major challenge in obtaining high quality decrypted images. This problem can be addressed by employing a QR code based noise-free scheme. Previous works have been conducted for optically encrypting a few characters or a short expression employing QR codes. This paper proposes a practical scheme for optically encrypting and decrypting a gray-scale image based on QR codes for the first time. The proposed scheme is compatible with common QR code generators and readers. Numerical simulation results reveal the proposed method can encrypt and decrypt an input image correctly.

The FBI wavelet/scalar quantization standard for gray-scale fingerprint image compression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bradley, J.N.; Brislawn, C.M.; Hopper, T.

1993-05-01

The FBI has recently adopted a standard for the compression of digitized 8-bit gray-scale fingerprint images. The standard is based on scalar quantization of a 64-subband discrete wavelet transform decomposition of the images, followed by Huffman coding. Novel features of the algorithm include the use of symmetric boundary conditions for transforming finite-length signals and a subband decomposition tailored for fingerprint images scanned at 500 dpi. The standard is intended for use in conjunction with ANSI/NBS-CLS 1-1993, American National Standard Data Format for the Interchange of Fingerprint Information, and the FBI`s Integrated Automated Fingerprint Identification System.

The FBI wavelet/scalar quantization standard for gray-scale fingerprint image compression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bradley, J.N.; Brislawn, C.M.; Hopper, T.

1993-01-01

The FBI has recently adopted a standard for the compression of digitized 8-bit gray-scale fingerprint images. The standard is based on scalar quantization of a 64-subband discrete wavelet transform decomposition of the images, followed by Huffman coding. Novel features of the algorithm include the use of symmetric boundary conditions for transforming finite-length signals and a subband decomposition tailored for fingerprint images scanned at 500 dpi. The standard is intended for use in conjunction with ANSI/NBS-CLS 1-1993, American National Standard Data Format for the Interchange of Fingerprint Information, and the FBI's Integrated Automated Fingerprint Identification System.

Neuroimaging correlates of parent ratings of working memory in typically developing children

PubMed Central

Mahone, E. Mark; Martin, Rebecca; Kates, Wendy R.; Hay, Trisha; Horská, Alena

2009-01-01

The purpose of the present study was to investigate construct validity of parent ratings of working memory in children, using a multi-trait/multi-method design including neuroimaging, rating scales, and performance-based measures. Thirty-five typically developing children completed performance-based tests of working memory and nonexecutive function (EF) skills, received volumetric MRI, and were rated by parents on both EF-specific and broad behavior rating scales. After controlling for total cerebral volume and age, parent ratings of working memory were significantly correlated with frontal gray, but not temporal, parietal, or occipital gray, or any lobar white matter volumes. Performance-based measures of working memory were also moderately correlated with frontal lobe gray matter volume; however, non-EF parent ratings and non-EF performance-based measures were not correlated with frontal lobe volumes. Results provide preliminary support for the convergent and discriminant validity of parent ratings of working memory, and emphasize their utility in exploring brain–behavior relationships in children. Rating scales that directly examine EF skills may potentially have ecological validity, not only for “everyday” function, but also as correlates of brain volume. PMID:19128526

Cellular automata rule characterization and classification using texture descriptors

NASA Astrophysics Data System (ADS)

Machicao, Jeaneth; Ribas, Lucas C.; Scabini, Leonardo F. S.; Bruno, Odermir M.

2018-05-01

The cellular automata (CA) spatio-temporal patterns have attracted the attention from many researchers since it can provide emergent behavior resulting from the dynamics of each individual cell. In this manuscript, we propose an approach of texture image analysis to characterize and classify CA rules. The proposed method converts the CA spatio-temporal patterns into a gray-scale image. The gray-scale is obtained by creating a binary number based on the 8-connected neighborhood of each dot of the CA spatio-temporal pattern. We demonstrate that this technique enhances the CA rule characterization and allow to use different texture image analysis algorithms. Thus, various texture descriptors were evaluated in a supervised training approach aiming to characterize the CA's global evolution. Our results show the efficiency of the proposed method for the classification of the elementary CA (ECAs), reaching a maximum of 99.57% of accuracy rate according to the Li-Packard scheme (6 classes) and 94.36% for the classification of the 88 rules scheme. Moreover, within the image analysis context, we found a better performance of the method by means of a transformation of the binary states to a gray-scale.

Wavelet Transforms in Parallel Image Processing

DTIC Science & Technology

1994-01-27

NUMBER OF PAGES Object Segmentation, Texture Segmentation, Image Compression, Image 137 Halftoning , Neural Network, Parallel Algorithms, 2D and 3D...Vector Quantization of Wavelet Transform Coefficients ........ ............................. 57 B.1.f Adaptive Image Halftoning based on Wavelet...application has been directed to the adaptive image halftoning . The gray information at a pixel, including its gray value and gradient, is represented by

Generalized image contrast enhancement technique based on Heinemann contrast discrimination model

NASA Astrophysics Data System (ADS)

Liu, Hong; Nodine, Calvin F.

1994-03-01

This paper presents a generalized image contrast enhancement technique which equalizes perceived brightness based on the Heinemann contrast discrimination model. This is a modified algorithm which presents an improvement over the previous study by Mokrane in its mathematically proven existence of a unique solution and in its easily tunable parameterization. The model uses a log-log representation of contrast luminosity between targets and the surround in a fixed luminosity background setting. The algorithm consists of two nonlinear gray-scale mapping functions which have seven parameters, two of which are adjustable Heinemann constants. Another parameter is the background gray level. The remaining four parameters are nonlinear functions of gray scale distribution of the image, and can be uniquely determined once the previous three are given. Tests have been carried out to examine the effectiveness of the algorithm for increasing the overall contrast of images. It can be demonstrated that the generalized algorithm provides better contrast enhancement than histogram equalization. In fact, the histogram equalization technique is a special case of the proposed mapping.

The Effect of Coloring and Compacting Pressure Paving Block by Adding 5 Wt.% Fly Ash in The Compressive Strength

NASA Astrophysics Data System (ADS)

Nurzal; Nursyuhada, Aries

2017-12-01

This research aims based on SNI 03-0691-1996 to investigate the effect of coloring and compacting pressure with the addition of 5 wt.% fly ash (Fa) on compressive strength. Fa derived from waste material coal-fired Sijantang Sawahlunto thermal power plant. The growing production of Fa caused negative environmental impact. So, one of the solutions to overcome that effects is to use the Fa as a raw material for paving block mixture that can reduce the cost of raw material and increase its strength. Paving blocks are gray and red with 0 wt.%, 5 wt.% Fa + Pb composition. Compaction pressure variations 55, 65, 75, 85 and 95 Kg/cm2. The drying time for 35 days. Specimens were produced in the form of rectangular bar (length, L = 20 cm, width, B = 10 cm, thickness, W = 6 cm). The test results showed that the addition of 5 wt% FA has a compressive strength value higher than 0 wt%. The red color has a compressive strength lower than the gray color paving block caused the red color (Iron Oxide) is less binding at the time of mixing the material. Gray and red Paving blocks both increase in each additional compaction pressure, because the higher the compaction pressure will increase the bond between the particles so porosity is reduced increased compressive strength. The overall data, the gray paving block with the composition of 5 wt% FA at compaction pressure 95 kg/cm2 with the optimal compressive strength value of 36.1 MPa and the lowest value is found in the red color paving block at 0 wt% FA at a pressure of 55 kg/cm2 with a value of 6.5 MPa. Gray and red Color paving blocks has a compressive strength quality based on SNI 03-0691-1996.

Complex-valued multistate associative memory with nonlinear multilevel functions for gray-level image reconstruction.

PubMed

Tanaka, Gouhei; Aihara, Kazuyuki

2009-09-01

A widely used complex-valued activation function for complex-valued multistate Hopfield networks is revealed to be essentially based on a multilevel step function. By replacing the multilevel step function with other multilevel characteristics, we present two alternative complex-valued activation functions. One is based on a multilevel sigmoid function, while the other on a characteristic of a multistate bifurcating neuron. Numerical experiments show that both modifications to the complex-valued activation function bring about improvements in network performance for a multistate associative memory. The advantage of the proposed networks over the complex-valued Hopfield networks with the multilevel step function is more outstanding when a complex-valued neuron represents a larger number of multivalued states. Further, the performance of the proposed networks in reconstructing noisy 256 gray-level images is demonstrated in comparison with other recent associative memories to clarify their advantages and disadvantages.

Significance of Intermediate Values of Fractional Flow Reserve in Patients With Coronary Artery Disease.

PubMed

Adjedj, Julien; De Bruyne, Bernard; Floré, Vincent; Di Gioia, Giuseppe; Ferrara, Angela; Pellicano, Mariano; Toth, Gabor G; Bartunek, Jozef; Vanderheyden, Marc; Heyndrickx, Guy R; Wijns, William; Barbato, Emanuele

2016-02-02

The fractional flow reserve (FFR) value of 0.75 has been validated against ischemic testing, whereas the FFR value of 0.80 has been widely accepted to guide clinical decision making. However, revascularization when FFR is 0.76 to 0.80, within the so-called gray zone, is still debatable. From February 1997 to June 2013, all patients with single-segment disease and an FFR value within the gray zone or within the 2 neighboring FFR strata (0.70-0.75 and 0.81-0.85) were included. Study end points consisted of major adverse cardiovascular events (death, myocardial infarction, and any revascularization) up to 5 years. Of 17 380 FFR measurements, 1459 patients were included. Of them, 449 patients were treated with revascularization and 1010 patients were treated with medical therapy. In the gray zone, the major adverse cardiovascular events rate was similar (37 [13.9%] versus 21 [11.2%], respectively; P=0.3) between medical therapy and revascularization, whereas a strong trend toward a higher rate of death or myocardial infarction (25 [9.4] versus 9 [4.8], P=0.06) and overall death (20 [7.5] versus 6 [3.2], P=0.059) was observed in the medical therapy group. Among medical therapy patients, a significant step-up increase in major adverse cardiovascular events rate was observed across the 3 FFR strata, especially with proximal lesion location. In revascularization patients, the major adverse cardiovascular events rate was not different across the 3 FFR strata. FFR in and around the gray zone bears a major prognostic value, especially in proximal lesions. These data confirm that FFR≤0.80 is valid to guide clinical decision making. © 2016 American Heart Association, Inc.

Colorization and Automated Segmentation of Human T2 MR Brain Images for Characterization of Soft Tissues

PubMed Central

Attique, Muhammad; Gilanie, Ghulam; Hafeez-Ullah; Mehmood, Malik S.; Naweed, Muhammad S.; Ikram, Masroor; Kamran, Javed A.; Vitkin, Alex

2012-01-01

Characterization of tissues like brain by using magnetic resonance (MR) images and colorization of the gray scale image has been reported in the literature, along with the advantages and drawbacks. Here, we present two independent methods; (i) a novel colorization method to underscore the variability in brain MR images, indicative of the underlying physical density of bio tissue, (ii) a segmentation method (both hard and soft segmentation) to characterize gray brain MR images. The segmented images are then transformed into color using the above-mentioned colorization method, yielding promising results for manual tracing. Our color transformation incorporates the voxel classification by matching the luminance of voxels of the source MR image and provided color image by measuring the distance between them. The segmentation method is based on single-phase clustering for 2D and 3D image segmentation with a new auto centroid selection method, which divides the image into three distinct regions (gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) using prior anatomical knowledge). Results have been successfully validated on human T2-weighted (T2) brain MR images. The proposed method can be potentially applied to gray-scale images from other imaging modalities, in bringing out additional diagnostic tissue information contained in the colorized image processing approach as described. PMID:22479421

Segmentation of white rat sperm image

NASA Astrophysics Data System (ADS)

Bai, Weiguo; Liu, Jianguo; Chen, Guoyuan

2011-11-01

The segmentation of sperm image exerts a profound influence in the analysis of sperm morphology, which plays a significant role in the research of animals' infertility and reproduction. To overcome the microscope image's properties of low contrast and highly polluted noise, and to get better segmentation results of sperm image, this paper presents a multi-scale gradient operator combined with a multi-structuring element for the micro-spermatozoa image of white rat, as the multi-scale gradient operator can smooth the noise of an image, while the multi-structuring element can retain more shape details of the sperms. Then, we use the Otsu method to segment the modified gradient image whose gray scale processed is strong in sperms and weak in the background, converting it into a binary sperm image. As the obtained binary image owns impurities that are not similar with sperms in the shape, we choose a form factor to filter those objects whose form factor value is larger than the select critical value, and retain those objects whose not. And then, we can get the final binary image of the segmented sperms. The experiment shows this method's great advantage in the segmentation of the micro-spermatozoa image.

Adaptive histogram equalization in digital radiography of destructive skeletal lesions.

PubMed

Braunstein, E M; Capek, P; Buckwalter, K; Bland, P; Meyer, C R

1988-03-01

Adaptive histogram equalization, an image-processing technique that distributes pixel values of an image uniformly throughout the gray scale, was applied to 28 plain radiographs of bone lesions, after they had been digitized. The non-equalized and equalized digital images were compared by two skeletal radiologists with respect to lesion margins, internal matrix, soft-tissue mass, cortical breakthrough, and periosteal reaction. Receiver operating characteristic (ROC) curves were constructed on the basis of the responses. Equalized images were superior to nonequalized images in determination of cortical breakthrough and presence or absence of periosteal reaction. ROC analysis showed no significant difference in determination of margins, matrix, or soft-tissue masses.

Temporal changes in the outcomes of HIV-exposed infants in Kinshasa, Democratic Republic of Congo during a period of rapidly evolving guidelines for care (2007–2013)

PubMed Central

Feinstein, Lydia; Edmonds, Andrew; Chalachala, Jean Lambert; Okitolonda, Vitus; Lusiama, Jean; Van Rie, Annelies; Chi, Benjamin H.; Cole, Stephen R.; Behets, Frieda

2015-01-01

Objective Guidelines for prevention of mother-to-child transmission of HIV have developed rapidly, yet little is known about how outcomes of HIV-exposed infants have changed over time. We describe HIV-exposed infant outcomes in Kinshasa, Democratic Republic of Congo, between 2007 and 2013. Design Cohort study of mother–infant pairs enrolled in family-centered comprehensive HIV care. Methods Accounting for competing risks, we estimated the cumulative incidences of early infant diagnosis, HIV transmission, death, loss to follow-up, and combination antiretroviral therapy (cART) initiation for infants enrolled in three periods (2007–2008, 2009–2010, and 2011–2012). Results 1707 HIV-exposed infants enrolled at a median age of 2.6 weeks. Among infants whose mothers had recently enrolled into HIV care (N = 1411), access to EID by age two months increased from 28% (95% confidence limits [CL]: 24,34%) among infants enrolled in 2007-2008 to 63% (95% CL: 59,68%) among infants enrolled in 2011–2012 (Gray's p-value <0.01). The 18-month cumulative incidence of HIV declined from 16% (95% CL: 11,22%) for infants enrolled in 2007–2008 to 11% (95% CL: 8,16%) for infants enrolled in 2011–2012 (Gray's p-value = 0.19). The 18-month cumulative incidence of death also declined, from 8% (95% CL: 5,12%) to 3% (95% CL: 2,5%) (Gray's p-value = 0.02). LTFU did not improve, with 18-month cumulative incidences of 19% (95% CL: 15,23%) for infants enrolled in 2007-2008 and 22% (95% CL: 18,26%) for infants enrolled in 2011–2012 (Gray's p-value = 0.06). Among HIV-infected infants, the 24-month cumulative incidence of cART increased from 61% (95% CL: 43,75%) to 97% (95% CL: 82,100%) (Gray's p-value < 0.01); the median age at cART decreased from 17.9 to 9.3 months. Outcomes were better for infants whose mothers enrolled before pregnancy. Conclusions We observed encouraging improvements, but continued efforts are needed. PMID:24991903

Profiling the Phenolic Compounds of the Four Major Seed Coat Types and Their Relation to Color Genes in Lentil.

PubMed

Mirali, Mahla; Purves, Randy W; Vandenberg, Albert

2017-05-26

Phenolic compounds can provide antioxidant health benefits for humans, and foods such as lentils can be valuable dietary sources of different subclasses of these secondary metabolites. This study used LC-MS analyses to compare the phenolic profiles of lentil genotypes with four seed coat background colors (green, gray, tan, and brown) and two cotyledon colors (red and yellow) grown at two locations. The mean area ratio per mg sample (MARS) values of various phenolic compounds in lentil seeds varied with the different seed coat colors conferred by specific genotypes. Seed coats of lentil genotypes with the homozygous recessive tgc allele (green and gray seed coats) had higher MARS values of flavan-3-ols, proanthocyanidins, and some flavonols. This suggests lentils featuring green and gray seed coats might be more promising as health-promoting foods.

Regional gray matter volume in the posterior precuneus is associated with general self-efficacy.

PubMed

Sugiura, Ayaka; Aoki, Ryuta; Murayama, Kou; Yomogida, Yukihito; Haji, Tomoki; Saito, Atsuko; Hasegawa, Toshikazu; Matsumoto, Kenji

2016-12-14

Motivation in doing a task is influenced not only by the expected outcome of the task but also by the belief that one has in successfully executing the task. Over time, individuals accumulate experiences that contribute toward a general belief in one's overall ability to successfully perform tasks, which is called general self-efficacy (GSE). We investigated the relationship between regional gray matter volume and individual differences in GSE. Brain anatomy was analyzed using magnetic resonance images obtained from 64 healthy right-handed participants who had completed Sherer's GSE scale. After controlling for other factors related to motivation, age, sex, and total gray matter volume of each participant, results showed that regional gray matter volume in the posterior part of the precuneus significantly and positively correlated with the GSE score. These results suggest that one's accumulated experiences of success and failure, which contribute toward GSE, also influence the anatomical characteristics of the precuneus.

A Hybrid Soft-computing Method for Image Analysis of Digital Plantar Scanners.

PubMed

Razjouyan, Javad; Khayat, Omid; Siahi, Mehdi; Mansouri, Ali Alizadeh

2013-01-01

Digital foot scanners have been developed in recent years to yield anthropometrists digital image of insole with pressure distribution and anthropometric information. In this paper, a hybrid algorithm containing gray level spatial correlation (GLSC) histogram and Shanbag entropy is presented for analysis of scanned foot images. An evolutionary algorithm is also employed to find the optimum parameters of GLSC and transform function of the membership values. Resulting binary images as the thresholded images are undergone anthropometric measurements taking in to account the scale factor of pixel size to metric scale. The proposed method is finally applied to plantar images obtained through scanning feet of randomly selected subjects by a foot scanner system as our experimental setup described in the paper. Running computation time and the effects of GLSC parameters are investigated in the simulation results.

Recognition of Roasted Coffee Bean Levels using Image Processing and Neural Network

NASA Astrophysics Data System (ADS)

Nasution, T. H.; Andayani, U.

2017-03-01

The coffee beans roast levels have some characteristics. However, some people cannot recognize the coffee beans roast level. In this research, we propose to design a method to recognize the coffee beans roast level of images digital by processing the image and classifying with backpropagation neural network. The steps consist of how to collect the images data with image acquisition, pre-processing, feature extraction using Gray Level Co-occurrence Matrix (GLCM) method and finally normalization of data extraction using decimal scaling features. The values of decimal scaling features become an input of classifying in backpropagation neural network. We use the method of backpropagation to recognize the coffee beans roast levels. The results showed that the proposed method is able to identify the coffee roasts beans level with an accuracy of 97.5%.

Climatic variation and the distribution of an amphibian polyploid complex

USGS Publications Warehouse

Otto, C.R.V.; Snodgrass, J.W.; Forester, D.C.; Mitchell, J.C.; Miller, R.W.

2007-01-01

1. The establishment of polyploid populations involves the persistence and growth of the polyploid in the presence of the progenitor species. Although there have been a number of animal polyploid species documented, relatively few inquiries have been made into the large-scale mechanisms of polyploid establishment in animal groups. Herein we investigate the influence of regional climatic conditions on the distributional patterns of a diploid-tetraploid species pair of gray treefrogs, Hyla chrysoscelis and H. versicolor (Anura: Hylidae) in the mid-Atlantic region of eastern North America. 2. Calling surveys at breeding sites were used to document the distribution of each species. Twelve climatic models and one elevation model were generated to predict climatic and elevation values for gray treefrog breeding sites. A canonical analysis of discriminants was used to describe relationships between climatic variables, elevation and the distribution of H. chrysoscelis and H. versicolor. 3. There was a strong correlation between several climatic variables, elevation and the distribution of the gray treefrog complex. Specifically, the tetraploid species almost exclusively occupied areas of higher elevation, where climatic conditions were relatively severe (colder, drier, greater annual variation). In contrast, the diploid species was restricted to lower elevations, where climatic conditions were warmer, wetter and exhibited less annual variation. 4. Clusters of syntopic sites were associated with areas of high variation in annual temperature and precipitation during the breeding season. 5. Our data suggest that large-scale climatic conditions have played a role in the establishment of the polyploid H. versicolor in at least some portions of its range. The occurrence of the polyploid and absence of the progenitor in colder, drier and more varied environments suggests the polyploid may posses a tolerance of severe environmental conditions that is not possessed by the diploid progenitor. 6. Our findings support the hypothesis that increased tolerance to severe environmental conditions is a plausible mechanism of polyploid establishment.

Gray-matter macrostructure in cognitively healthy older persons: Associations with age and cognition

PubMed Central

Fleischman, Debra A.; Leurgans, Sue; Arfanakis, Konstantinos; Arvanitakis, Zoe; Barnes, Lisa L.; Boyle, Patricia A.; Han, S. Duke; Bennett, David A.

2013-01-01

A deeper understanding of brain macrostructure and its associations with cognition in persons who are considered cognitively healthy is critical to the early detection of persons at risk of developing dementia. Few studies have examined the associations of all three gray-matter macrostructural brain indices (volume, thickness, surface area) with age and cognition, in the same persons who are over the age of 65 and do not have cognitive impairment. We performed automated morphometric reconstruction of total gray matter, cortical gray matter, subcortical gray matter and 84 individual regions in 186 participants (60% over the age of 80) without cognitive impairment. Morphometric measures were scaled and expressed as difference per decade of age and an adjusted score was created to identify those regions in which there was greater atrophy per decade of age compared to cortical or subcortical brain averages. The results showed that there is substantial total volume loss and cortical thinning in cognitively healthy older persons. Thinning was more widespread than volume loss, but volume loss, particularly in temporoparietal and hippocampal regions, was more strongly associated with cognition. PMID:23955313

Seed viability detection using computerized false-color radiographic image enhancement

NASA Technical Reports Server (NTRS)

Vozzo, J. A.; Marko, Michael

1994-01-01

Seed radiographs are divided into density zones which are related to seed germination. The seeds which germinate have densities relating to false-color red. In turn, a seed sorter may be designed which rejects those seeds not having sufficient red to activate a gate along a moving belt containing the seed source. This results in separating only seeds with the preselected densities representing biological viability lending to germination. These selected seeds demand a higher market value. Actual false-coloring isn't required for a computer to distinguish the significant gray-zone range. This range can be predetermined and screened without the necessity of red imaging. Applying false-color enhancement is a means of emphasizing differences in densities of gray within any subject from photographic, radiographic, or video imaging. Within the 0-255 range of gray levels, colors can be assigned to any single level or group of gray levels. Densitometric values then become easily recognized colors which relate to the image density. Choosing a color to identify any given density allows separation by morphology or composition (form or function). Additionally, relative areas of each color are readily available for determining distribution of that density by comparison with other densities within the image.

GrayStar: Web-based pedagogical stellar modeling

NASA Astrophysics Data System (ADS)

Short, C. Ian

2017-01-01

GrayStar is a web-based pedagogical stellar model. It approximates stellar atmospheric and spectral line modeling in JavaScript with visualization in HTML. It is suitable for a wide range of education and public outreach levels depending on which optional plots and print-outs are turned on. All plots and renderings are pure basic HTML and the plotting module contains original HTML procedures for automatically scaling and graduating x- and y-axes.

Externalizing personality traits, empathy, and gray matter volume in healthy young drinkers

PubMed Central

Charpentier, Judith; Dzemidzic, Mario; West, John; Oberlin, Brandon G.; Eiler, William J.A.; Saykin, Andrew J.; Kareken, David A.

2016-01-01

Externalizing psychopathology has been linked to prefrontal abnormalities. While clinically diagnosed subjects show altered frontal gray matter, it is unknown if similar deficits relate to externalizing traits in non-clinical populations. We used voxel-based morphometry (VBM) to retrospectively analyze the cerebral gray matter volume of 176 young adult social to heavy drinkers (mean age= 24.0 ± 2.9, male= 83.5%) from studies of alcoholism risk. We hypothesized that prefrontal gray matter volume and externalizing traits would be correlated. Externalizing personality trait components— Boredom Susceptibility-Impulsivity (BS/IMP) and Empathy/Low Antisocial Behaviors (EMP/LASB)— were tested for correlations with gray matter partial volume estimates (gmPVE). Significantly large clusters (pFWE < 0.05, family-wise whole-brain corrected) of gmPVE correlated with EMP/LASB in dorsolateral and medial prefrontal regions, and in occipital cortex. BS/IMP did not correlate with gmPVE, but one scale of impulsivity (Eysenck I7) correlated positively with bilateral inferior frontal/orbitofrontal, and anterior insula gmPVE. In this large sample of community-dwelling young adults, antisocial behavior/low empathy corresponded with reduced prefrontal and occipital gray matter, while impulsivity correlated with increased inferior frontal and anterior insula cortical volume. These findings add to a literature indicating that externalizing personality features involve altered frontal architecture. PMID:26778367

Morphometric brain characterization of refractory obsessive-compulsive disorder: diffeomorphic anatomic registration using exponentiated Lie algebra.

PubMed

Tang, Wanjie; Li, Bin; Huang, Xiaoqi; Jiang, Xiaoyu; Li, Fei; Wang, Lijuan; Chen, Taolin; Wang, Jinhui; Gong, Qiyong; Yang, Yanchun

2013-10-01

Few studies have used neuroimaging to characterize treatment-refractory obsessive-compulsive disorder (OCD). This study sought to explore gray matter structure in patients with treatment-refractory OCD and compare it with that of healthy controls. A total of 18 subjects with treatment-refractory OCD and 26 healthy volunteers were analyzed by MRI using a 3.0-T scanner and voxel-based morphometry (VBM). Diffeomorphic anatomical registration using exponentiated Lie algebra (DARTEL) was used to identify structural changes in gray matter associated with treatment-refractory OCD. A partial correlation model was used to analyze whether morphometric changes were associated with Yale-Brown Obsessive-Compulsive Scale scores and illness duration. Gray matter volume did not differ significantly between the two groups. Treatment-refractory OCD patients showed significantly lower gray matter density than healthy subjects in the left posterior cingulate cortex (PCC) and mediodorsal thalamus (MD) and significantly higher gray matter density in the left dorsal striatum (putamen). These changes did not correlate with symptom severity or illness duration. Our findings provide new evidence of deficits in gray matter density in treatment-refractory OCD patients. These patients may show characteristic density abnormalities in the left PCC, MD and dorsal striatum (putamen), which should be verified in longitudinal studies. © 2013. Published by Elsevier Inc. All rights reserved.

A survey of quality measures for gray-scale image compression

NASA Technical Reports Server (NTRS)

Eskicioglu, Ahmet M.; Fisher, Paul S.

1993-01-01

Although a variety of techniques are available today for gray-scale image compression, a complete evaluation of these techniques cannot be made as there is no single reliable objective criterion for measuring the error in compressed images. The traditional subjective criteria are burdensome, and usually inaccurate or inconsistent. On the other hand, being the most common objective criterion, the mean square error (MSE) does not have a good correlation with the viewer's response. It is now understood that in order to have a reliable quality measure, a representative model of the complex human visual system is required. In this paper, we survey and give a classification of the criteria for the evaluation of monochrome image quality.

Investigation of mindfulness meditation practitioners with voxel-based morphometry

PubMed Central

Hölzel, Britta K.; Ott, Ulrich; Gard, Tim; Hempel, Hannes; Weygandt, Martin; Morgen, Katrin; Vaitl, Dieter

2008-01-01

Mindfulness meditators practice the non-judgmental observation of the ongoing stream of internal experiences as they arise. Using voxel-based morphometry, this study investigated MRI brain images of 20 mindfulness (Vipassana) meditators (mean practice 8.6 years; 2 h daily) and compared the regional gray matter concentration to that of non-meditators matched for sex, age, education and handedness. Meditators were predicted to show greater gray matter concentration in regions that are typically activated during meditation. Results confirmed greater gray matter concentration for meditators in the right anterior insula, which is involved in interoceptive awareness. This group difference presumably reflects the training of bodily awareness during mindfulness meditation. Furthermore, meditators had greater gray matter concentration in the left inferior temporal gyrus and right hippocampus. Both regions have previously been found to be involved in meditation. The mean value of gray matter concentration in the left inferior temporal gyrus was predictable by the amount of meditation training, corroborating the assumption of a causal impact of meditation training on gray matter concentration in this region. Results suggest that meditation practice is associated with structural differences in regions that are typically activated during meditation and in regions that are relevant for the task of meditation. PMID:19015095

[Research on K-means clustering segmentation method for MRI brain image based on selecting multi-peaks in gray histogram].

PubMed

Chen, Zhaoxue; Yu, Haizhong; Chen, Hao

2013-12-01

To solve the problem of traditional K-means clustering in which initial clustering centers are selected randomly, we proposed a new K-means segmentation algorithm based on robustly selecting 'peaks' standing for White Matter, Gray Matter and Cerebrospinal Fluid in multi-peaks gray histogram of MRI brain image. The new algorithm takes gray value of selected histogram 'peaks' as the initial K-means clustering center and can segment the MRI brain image into three parts of tissue more effectively, accurately, steadily and successfully. Massive experiments have proved that the proposed algorithm can overcome many shortcomings caused by traditional K-means clustering method such as low efficiency, veracity, robustness and time consuming. The histogram 'peak' selecting idea of the proposed segmentootion method is of more universal availability.

Gray matter morphological anomalies in the cerebellar vermis in first-episode schizophrenia patients with cognitive deficits.

PubMed

Wang, Jingjuan; Zhou, Li; Cui, Chunlei; Liu, Zhening; Lu, Jie

2017-11-22

Cognitive deficits are a core feature of early schizophrenia. However, the pathological foundations underlying cognitive deficits are still unknown. The present study examined the association between gray matter density and cognitive deficits in first-episode schizophrenia. Structural magnetic resonance imaging of the brain was performed in 34 first-episode schizophrenia patients and 21 healthy controls. Patients were divided into two subgroups according to working memory task performance. The three groups were well matched for age, gender, and education, and the two patient groups were also further matched for diagnosis, duration of illness, and antipsychotic treatment. Voxel-based morphometric analysis was performed to estimate changes in gray matter density in first-episode schizophrenia patients with cognitive deficits. The relationships between gray matter density and clinical outcomes were explored. Patients with cognitive deficits were found to have reduced gray matter density in the vermis and tonsil of cerebellum compared with patients without cognitive deficits and healthy controls, decreased gray matter density in left supplementary motor area, bilateral precentral gyrus compared with patients without cognitive deficits. Classifier results showed GMD in cerebellar vermis tonsil cluster could differentiate SZ-CD from controls, left supplementary motor area cluster could differentiate SZ-CD from SZ-NCD. Gray matter density values of the cerebellar vermis cluster in patients groups were positively correlated with cognitive severity. Decreased gray matter density in the vermis and tonsil of cerebellum may underlie early psychosis and serve as a candidate biomarker for schizophrenia with cognitive deficits.

The Place of White in a World of Grays: A Double-Anchoring Theory of Lightness Perception

ERIC Educational Resources Information Center

Bressan, Paola

2006-01-01

The specific gray shades in a visual scene can be derived from relative luminance values only when an anchoring rule is followed. The double-anchoring theory I propose in this article, as a development of the anchoring theory of Gilchrist et al. (1999), assumes that any given region (a) belongs to one or more frameworks, created by Gestalt…

3D shape recovery from image focus using gray level co-occurrence matrix

NASA Astrophysics Data System (ADS)

Mahmood, Fahad; Munir, Umair; Mehmood, Fahad; Iqbal, Javaid

2018-04-01

Recovering a precise and accurate 3-D shape of the target object utilizing robust 3-D shape recovery algorithm is an ultimate objective of computer vision community. Focus measure algorithm plays an important role in this architecture which convert the color values of each pixel of the acquired 2-D image dataset into corresponding focus values. After convolving the focus measure filter with the input 2-D image dataset, a 3-D shape recovery approach is applied which will recover the depth map. In this document, we are concerned with proposing Gray Level Co-occurrence Matrix along with its statistical features for computing the focus information of the image dataset. The Gray Level Co-occurrence Matrix quantifies the texture present in the image using statistical features and then applies joint probability distributive function of the gray level pairs of the input image. Finally, we quantify the focus value of the input image using Gaussian Mixture Model. Due to its little computational complexity, sharp focus measure curve, robust to random noise sources and accuracy, it is considered as superior alternative to most of recently proposed 3-D shape recovery approaches. This algorithm is deeply investigated on real image sequences and synthetic image dataset. The efficiency of the proposed scheme is also compared with the state of art 3-D shape recovery approaches. Finally, by means of two global statistical measures, root mean square error and correlation, we claim that this approach -in spite of simplicity generates accurate results.

Cerebellum and cognition in multiple sclerosis: the fall status matters.

PubMed

Kalron, Alon; Allali, Gilles; Achiron, Anat

2018-04-01

Cerebellar volume has been linked with cognitive performances in MS; however, the association in terms of fall status has never been compared. Therefore, the objective of the current study was to compare cognitive performance with cerebellar volume between MS fallers and non-fallers. The cross-sectional study included 140 PwMS (96 women). MRI volumetric analysis was based on the FreeSurfer image analysis suite. Volumes of the cerebellar gray and white matter were identified as the region of interest. Cognitive function included scores obtained from a computerized cognitive battery of tests. The sample was divided into fallers and non-fallers. MS fallers demonstrated a lower global cognitive performance and reduced gray and white matter cerebellar volumes compared to non-fallers. A significant association was found between total gray and white matter cerebellar volume and visual spatial subdomain (P value = 0.044 and 0.032, respectively) in the non-fallers group. The association remained significant after controlling for the total cranial volume and neurological disability (P value = 0.026 and 0.047, respectively). A relationship was found between the visual spatial score and the left gray matter cerebellum volume; R 2  = 0.44, P value = 0.021. We believe that a unique relationship exists between the cerebellum structure and cognitive processing according to fall history in PwMS and should be considered when investigating the association between brain functioning and cognitive performances in MS.

The characteristics of phosphorus adsorption and desorption in gray desert soil of Xinjiang, China

NASA Astrophysics Data System (ADS)

Wang, B.; Sun, J. S.; Liu, H.; Ma, Y. B.

2017-07-01

The characteristics of phosphorus (P) adsorption and desorption in Xinjiang gray desert soil (0 - 200 mm) of China in the long-term fertilization condition is affected by the level of soil P content which studied through an isothermal adsorption and desorption experiments of P. The results stated that within the experimental concentration range, with the increase of the amount of outer-source phosphorus, P adsorption, desorption and desorption rate increased and adsorption rate decreased gradually in different Olsen-P levels of gray desert soil in Xinjiang, China. Olsen-P content is significantly correlated with the P adsorption saturation (DPS) of gray desert soil. The maximum adsorption capacity (Xm ) of the treatments followed an extremely significant decreasing order of CK>NPK≈NPKM>PK≈NPKS. The maximum buffer capacity (MBC) and adsorption constant (K) of the NPK treatment was much higher than NPKM, NPKS, PK and CK treatments. And, MBC value of CK treatment was extremely higher than NPKS and PK, however, the differences between NPKM and CK, NPKS and PK were not significant. The comparison between NPKM, NPKS, PK and CK treatments showed no significant difference in K value, but these four showed significantly lower than NPK treatments. The value of soil easy desorption P (RDP) of NPKS and NPKM was significantly higher than NPK and PK, and the chemical fertilizer with organic fertilizer was a best way to release the phosphorus for Xinjiang agricultural production, China.

Design of a 16 gray scales 320 × 240 pixels OLED-on-silicon driving circuit

NASA Astrophysics Data System (ADS)

Ran, Huang; Xiaohui, Wang; Wenbo, Wang; Huan, Du; Zhengsheng, Han

2009-01-01

A 320×240 pixel organic-light-emitting-diode-on-silicon (OLEDoS) driving circuit is implemented using the standard 0.5 μm CMOS process of CSMC. It gives 16 gray scales with integrated 4 bit D/A converters. A three-transistor voltage-programmed OLED pixel driver is proposed, which can realize the very small current driving required for the OLEDoS microdisplay. Both the D/A converter and the pixel driver are implemented with pMOS devices. The pass-transistor and capacitance in the OLED pixel driver can be used to sample the output of the D/A converter. An additional pMOS is added to OLED pixel driver, which is used to control the D/A converter operating only when one row is on. This can reduce the circuit's power consumption. This driving circuit can work properly in a frame frequency of 50 Hz, and the final layout of this circuit is given. The pixel area is 28.4 × 28.4 μm2 and the display area is 10.7 × 8.0 mm2 (the diagonal is about 13 mm). The measured pixel gray scale voltage shows that the function of the driver circuit is correct, and the power consumption of the chip is about 350 mW.

Video rate morphological processor based on a redundant number representation

NASA Astrophysics Data System (ADS)

Kuczborski, Wojciech; Attikiouzel, Yianni; Crebbin, Gregory A.

1992-03-01

This paper presents a video rate morphological processor for automated visual inspection of printed circuit boards, integrated circuit masks, and other complex objects. Inspection algorithms are based on gray-scale mathematical morphology. Hardware complexity of the known methods of real-time implementation of gray-scale morphology--the umbra transform and the threshold decomposition--has prompted us to propose a novel technique which applied an arithmetic system without carrying propagation. After considering several arithmetic systems, a redundant number representation has been selected for implementation. Two options are analyzed here. The first is a pure signed digit number representation (SDNR) with the base of 4. The second option is a combination of the base-2 SDNR (to represent gray levels of images) and the conventional twos complement code (to represent gray levels of structuring elements). Operation principle of the morphological processor is based on the concept of the digit level systolic array. Individual processing units and small memory elements create a pipeline. The memory elements store current image windows (kernels). All operation primitives of processing units apply a unified direction of digit processing: most significant digit first (MSDF). The implementation technology is based on the field programmable gate arrays by Xilinx. This paper justified the rationality of a new approach to logic design, which is the decomposition of Boolean functions instead of Boolean minimization.

Fabricating Blazed Diffraction Gratings by X-Ray Lithography

NASA Technical Reports Server (NTRS)

Mouroulis, Pantazis; Hartley, Frank; Wilson, Daniel

2004-01-01

Gray-scale x-ray lithography is undergoing development as a technique for fabricating blazed diffraction gratings. As such, gray-scale x-ray lithography now complements such other grating-fabrication techniques as mechanical ruling, holography, ion etching, laser ablation, laser writing, and electron-beam lithography. Each of these techniques offers advantages and disadvantages for implementing specific grating designs; no single one of these techniques can satisfy the design requirements for all applications. Gray-scale x-ray lithography is expected to be advantageous for making gratings on steeper substrates than those that can be made by electron-beam lithography. This technique is not limited to sawtooth groove profiles and flat substrates: various groove profiles can be generated on arbitrarily shaped (including highly curved) substrates with the same ease as sawtooth profiles can be generated on flat substrates. Moreover, the gratings fabricated by this technique can be made free of ghosts (spurious diffraction components attributable to small spurious periodicities in the locations of grooves). The first step in gray-scale x-ray lithography is to conformally coat a substrate with a suitable photoresist. An x-ray mask (see Figure 1) is generated, placed between the substrate and a source of collimated x-rays, and scanned over the substrate so as to create a spatial modulation in the exposure of the photoresist. Development of the exposed photoresist results in a surface corrugation that corresponds to the spatial modulation and that defines the grating surface. The grating pattern is generated by scanning an appropriately shaped x-ray area mask along the substrate. The mask example of Figure 1 would generate a blazed grating profile when scanned in the perpendicular direction at constant speed, assuming the photoresist responds linearly to incident radiation. If the resist response is nonlinear, then the mask shape can be modified to account for the nonlinearity and produce a desired groove profile. An example of grating grooves generated by this technique is shown in Figure 2. A maximum relative efficiency of 88 percent has been demonstrated.

Color line-scan technology in industrial applications

NASA Astrophysics Data System (ADS)

Lemstrom, Guy F.

1995-10-01

Color machine vision opens new possibilities for industrial on-line quality control applications. With color machine vision it's possible to detect different colors and shades, make color separation, spectroscopic applications and at the same time do measurements in the same way as with gray scale technology. These can be geometrical measurements such as dimensions, shape, texture etc. By combining these technologies in a color line scan camera, it brings the machine vision to new dimensions of realizing new applications and new areas in the machine vision business. Quality and process control requirements in the industry get more demanding every day. Color machine vision can be the solution for many simple tasks that haven't been realized with gray scale technology. The lack of detecting or measuring colors has been one reason why machine vision has not been used in quality control as much as it could have been. Color machine vision has shown a growing enthusiasm in the industrial machine vision applications. Potential areas of the industry include food, wood, mining and minerals, printing, paper, glass, plastic, recycling etc. Tasks are from simple measuring to total process and quality control. The color machine vision is not only for measuring colors. It can also be for contrast enhancement, object detection, background removing, structure detection and measuring. Color or spectral separation can be used in many different ways for working out machine vision application than before. It's only a question of how to use the benefits of having two or more data per measured pixel, instead of having only one as in case with traditional gray scale technology. There are plenty of potential applications already today that can be realized with color vision and it's going to give more performance to many traditional gray scale applications in the near future. But the most important feature is that color machine vision offers a new way of working out applications, where machine vision hasn't been applied before.

Early Head CT Findings Are Associated With Outcomes After Pediatric Out-of-Hospital Cardiac Arrest.

PubMed

Starling, Rebecca M; Shekdar, Karuna; Licht, Dan; Nadkarni, Vinay M; Berg, Robert A; Topjian, Alexis A

2015-07-01

Head CT after out-of-hospital cardiac arrest is often obtained to evaluate intracranial pathology. Among children admitted to the PICU following pediatric out-of-hospital cardiac arrest, we hypothesized that loss of gray-white matter differentiation and basilar cistern and sulcal effacement are associated with mortality and unfavorable neurologic outcome. Retrospective, cohort study. Single, tertiary-care center PICU. Seventy-eight patients less than 18 years old who survived out-of-hospital cardiac arrest to PICU admission and had a head CT within 24 hours of return of spontaneous circulation were evaluated from July 2005 through May 2012. None. Median time to head CT from return of spontaneous circulation was 3.3 hours (1.0, 6.0). Median patient age was 2.3 years (0.4, 9.5). Thirty-nine patients (50%) survived, of whom 29 (74%) had favorable neurologic outcome. Nonsurvivors were more likely than survivors to have 1) loss of gray-white matter differentiation (Hounsfield unit ratios, 0.96 [0.88, 1.07] vs 1.1 [1.07, 1.2]; p < 0.001), 2) basilar cistern effacement (93% vs 7%; p = 0.001; positive predictive value, 94%; negative predictive value, 59%), and 3) sulcal effacement (100% vs 0%; p ≤ 0.001; positive predictive value, 100%; negative predictive value, 68%). All patients with poor gray-white matter differentiation or sulcal effacement had unfavorable neurologic outcomes. Only one patient with basilar cistern effacement had favorable outcome. Loss of gray-white matter differentiation and basilar cistern effacement and sulcal effacement are associated with poor outcome after pediatric out-of-hospital cardiac arrest. Select patients may have favorable outcomes despite these findings.

Early Head CT Findings Are Associated With Outcomes After Pediatric Out-of-Hospital Cardiac Arrest

PubMed Central

Starling, Rebecca M.; Shekdar, Karuna; Licht, Dan; Nadkarni, Vinay M.; Berg, Robert A.; Topjian, Alexis A.

2015-01-01

Objectives Head CT after out-of-hospital cardiac arrest is often obtained to evaluate intracranial pathology. Among children admitted to the PICU following pediatric out-of-hospital cardiac arrest, we hypothesized that loss of gray-white matter differentiation and basilar cistern and sulcal effacement are associated with mortality and unfavorable neurologic outcome. Design Retrospective, cohort study. Setting Single, tertiary-care center PICU. Patients Seventy-eight patients less than 18 years old who survived out-of-hospital cardiac arrest to PICU admission and had a head CT within 24 hours of return of spontaneous circulation were evaluated from July 2005 through May 2012. Interventions None. Measurements and Main Results Median time to head CT from return of spontaneous circulation was 3.3 hours (1.0, 6.0). Median patient age was 2.3 years (0.4, 9.5). Thirty-nine patients (50%) survived, of whom 29 (74%) had favorable neurologic outcome. Nonsurvivors were more likely than survivors to have 1) loss of gray-white matter differentiation (Hounsfield unit ratios, 0.96 [0.88, 1.07] vs 1.1 [1.07, 1.2]; p < 0.001), 2) basilar cistern effacement (93% vs 7%; p = 0.001; positive predictive value, 94%; negative predictive value, 59%), and 3) sulcal effacement (100% vs 0%; p ≤ 0.001; positive predictive value, 100%; negative predictive value, 68%). All patients with poor gray-white matter differentiation or sulcal effacement had unfavorable neurologic outcomes. Only one patient with basilar cistern effacement had favorable outcome. Conclusions Loss of gray-white matter differentiation and basilar cistern effacement and sulcal effacement are associated with poor outcome after pediatric out-of-hospital cardiac arrest. Select patients may have favorable outcomes despite these findings. PMID:25844694

Contrast-enhanced color Doppler ultrasonography increases diagnostic accuracy for soft tissue tumors.

PubMed

Oebisu, Naoto; Hoshi, Manabu; Ieguchi, Makoto; Takada, Jun; Iwai, Tadashi; Ohsawa, Masahiko; Nakamura, Hiroaki

2014-10-01

Resolution of ultrasonography (US) has undergone marked development. Additionally, a new-generation contrast medium (Sonazoid) used for US is newly available. Contrast-enhanced US has been widely used for evaluating several types of cancer. In the present study, we evaluated the ability of color Doppler US (CDUS) and Sonazoid to differentiate between benign and malignant soft tissue tumors. A total of 180 patients (87 male, 93 female) were enrolled in the present study. The patient ages ranged from 1 to 91 years (mean 58.1±20.0 years). The maximum size, depth, tumor margins, shape, echogenicity and textural pattern were measured on gray-scale images. CDUS was used to evaluate the intratumoral blood flow with and without Sonazoid. Peak systolic flow velocity (Vp), mean flow velocity (Vm), resistivity index (RI) and pulsatility index (PI) of each detected intratumoral artery were automatically calculated with power Doppler US (PDUS). The present study included 118 benign and 62 malignant tumors. Statistical significances were found in size, depth, tumor margin and textural pattern but not in shape or echogenicity on gray-scale images. Before Sonazoid injection, CDUS findings showed 55% sensitivity, 77% specificity and 69% accuracy, whereas contrast-enhanced CDUS showed 87% sensitivity, 68% specificity and 74% accuracy. There were no statistically significant differences between malignant and benign tumors regarding the mean Vp, Vm, RI and PI values determined on PDUS. In conclusion, contrast-enhanced CDUS proved to be a reliable diagnostic tool for detecting malignant potential in soft tissue tumors.

Feasibility of dynamic models of the interaction of potential oil spills with bowhead and gray whales in the Bering, Chukchi, and Beaufort Seas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reed, M.; Bowles, A.E.; Anderson, E.L.

1984-08-01

Feasibility and design considerations for developing computer models of migratory bow-head and gray whales and linking such models to oil spill models for application in Alaskan Outer Continental Shelf areas were evaluated. A summary of all relevant bowhead and gray whale distributional and migration data were summarized and presented at monthly intervals. The data were, for the most part, deemed sufficient to prepare whale migration simulation models. A variety of whale migration conceptual models were devised and ranking was achieved by means of a scaling-weighted protocol. Existing oil spill trajectory and fate models, as well as conceptual models, were similarlymore » ranked.« less

Grays River Watershed and Biological Assessment Final Report 2006.

DOE Office of Scientific and Technical Information (OSTI.GOV)

May, Christopher W.; McGrath, Kathleen E.; Geist, David R.

2008-02-04

The Grays River Watershed and Biological Assessment was funded to address degradation and loss of spawning habitat for chum salmon (Onchorhynchus keta) and fall Chinook salmon (Onchoryhnchus tshawytscha). In 1999, the National Marine Fisheries Service listed lower Columbia River chum salmon as a threatened Evolutionarily Significant Unit (ESU) under the Endangered Species Act of 1973 (ESA). The Grays River watershed is one of two remaining significant chum salmon spawning locations in this ESU. Runs of Grays River chum and Chinook salmon have declined significantly during the past century, largely because of damage to spawning habitat associated with timber harvest andmore » agriculture in the watershed. In addition, approximately 20-25% of the then-remaining chum salmon spawning habitat was lost during a 1999 channel avulsion that destroyed an important artificial spawning channel operated by the Washington Department of Fish and Wildlife (WDFW). Although the lack of stable, high-quality spawning habitat is considered the primary physical limitation on Grays River chum salmon production today, few data are available to guide watershed management and channel restoration activities. The objectives of the Grays River Watershed and Biological Assessment project were to (1) perform a comprehensive watershed and biological analysis, including hydrologic, geomorphic, and ecological assessments; (2) develop a prioritized list of actions that protect and restore critical chum and Chinook salmon spawning habitat in the Grays River based on comprehensive geomorphic, hydrologic, and stream channel assessments; and (3) gain a better understanding of chum and Chinook salmon habitat requirements and survival within the lower Columbia River and the Grays River. The watershed-based approach to river ecosystem restoration relies on a conceptual framework that describes general relationships between natural landscape characteristics, watershed-scale habitat-forming processes, aquatic habitat conditions, and biological integrity. In addition, human land-use impacts are factored into the conceptual model because they can alter habitat quality and can disrupt natural habitat-forming processes. In this model (Figure S.1), aquatic habitat--both instream and riparian--is viewed as the link between watershed conditions and biologic responses. Based on this conceptual model, assessment of habitat loss and the resultant declines in salmonid populations can be conducted by relating current and historical (e.g., natural) habitat conditions to salmonid utilization, diversity, and abundance. In addition, assessing disrupted ecosystem functions and processes within the watershed can aid in identifying the causes of habitat change and the associated decline in biological integrity. In this same way, restoration, enhancement, and conservation projects can be identified and prioritized. A watershed assessment is primarily a landscape-scale evaluation of current watershed conditions and the associated hydrogeomorphic riverine processes. The watershed assessment conducted for this project focused on watershed processes that form and maintain salmonid habitat. Landscape metrics describing the level of human alteration of natural ecosystem attributes were used as indicators of water quality, hydrology, channel geomorphology, instream habitat, and biotic integrity. Ecological (watershed) processes are related to and can be predicted based on specific aspects of spatial pattern. This study evaluated the hydrologic regime, sediment delivery regime, and riparian condition of the sub-watersheds that comprise the upper Grays River watershed relative to their natural range of conditions. Analyses relied primarily on available geographic information system (GIS) data describing landscape characteristics such as climate, vegetation type and maturity, geology and soils, topography, land use, and road density. In addition to watershed-scale landscape characteristics, the study area was also evaluated on the riparian scale, with appropriate landscape variables analyzed within riparian buffers around each stream or river channel. Included in the overall watershed assessment are field habitat surveys and analyses of the physical and hydrological characteristics of primary chum and fall Chinook salmon spawning areas and spawning habitat availability and use. This assessment is a significant step in a comprehensive program to ensure the survival and recovery of Columbia River chum salmon in its most productive system and builds on existing recovery planning efforts for these ESA-listed salmonids within the Grays River and the lower Columbia River. This assessment also provides a basis for the recovery of other fish species in the Grays River, including coho salmon, winter steelhead, coastal cutthroat trout, and Pacific lamprey.« less

Grays River Watershed and Biological Assessment, 2006 Final Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

May, Christopher; Geist, David

2007-04-01

The Grays River Watershed and Biological Assessment was funded to address degradation and loss of spawning habitat for chum salmon (Onchorhynchus keta) and fall Chinook salmon (Onchoryhnchus tshawytscha). In 1999, the National Marine Fisheries Service listed lower Columbia River chum salmon as a threatened Evolutionarily Significant Unit (ESU) under the Endangered Species Act of 1973 (ESA). The Grays River watershed is one of two remaining significant chum salmon spawning locations in this ESU. Runs of Grays River chum and Chinook salmon have declined significantly during the past century, largely because of damage to spawning habitat associated with timber harvest andmore » agriculture in the watershed. In addition, approximately 20-25% of the then-remaining chum salmon spawning habitat was lost during a 1999 channel avulsion that destroyed an important artificial spawning channel operated by the Washington Department of Fish and Wildlife (WDFW). Although the lack of stable, high-quality spawning habitat is considered the primary physical limitation on Grays River chum salmon production today, few data are available to guide watershed management and channel restoration activities. The objectives of the Grays River Watershed and Biological Assessment project were to (1) perform a comprehensive watershed and biological analysis, including hydrologic, geomorphic, and ecological assessments; (2) develop a prioritized list of actions that protect and restore critical chum and Chinook salmon spawning habitat in the Grays River based on comprehensive geomorphic, hydrologic, and stream channel assessments; and (3) gain a better understanding of chum and Chinook salmon habitat requirements and survival within the lower Columbia River and the Grays River. The watershed-based approach to river ecosystem restoration relies on a conceptual framework that describes general relationships between natural landscape characteristics, watershed-scale habitat-forming processes, aquatic habitat conditions, and biological integrity. In addition, human land-use impacts are factored into the conceptual model because they can alter habitat quality and can disrupt natural habitat forming processes. In this model (Figure S.1), aquatic habitat--both instream and riparian--is viewed as the link between watershed conditions and biologic responses. Based on this conceptual model, assessment of habitat loss and the resultant declines in salmonid populations can be conducted by relating current and historical (e.g., natural) habitat conditions to salmonid utilization, diversity, and abundance. In addition, assessing disrupted ecosystem functions and processes within the watershed can aid in identifying the causes of habitat change and the associated decline in biological integrity. In this same way, restoration, enhancement, and conservation projects can be identified and prioritized. A watershed assessment is primarily a landscape-scale evaluation of current watershed conditions and the associated hydrogeomorphic riverine processes. The watershed assessment conducted for this project focused on watershed processes that form and maintain salmonid habitat. Landscape metrics describing the level of human alteration of natural ecosystem attributes were used as indicators of water quality, hydrology, channel geomorphology, instream habitat, and biotic integrity. Ecological (watershed) processes are related to and can be predicted based on specific aspects of spatial pattern. This study evaluated the hydrologic regime, sediment delivery regime, and riparian condition of the sub-watersheds that comprise the upper Grays River watershed relative to their natural range of conditions. Analyses relied primarily on available geographic information system (GIS) data describing landscape characteristics such as climate, vegetation type and maturity, geology and soils, topography, land use, and road density. In addition to watershed-scale landscape characteristics, the study area was also evaluated on the riparian scale, with appropriate landscape variables analyzed within riparian buffers around each stream or river channel. Included in the overall watershed assessment are field habitat surveys and analyses of the physical and hydrological characteristics of primary chum and fall Chinook salmon spawning areas and spawning habitat availability and use. This assessment is a significant step in a comprehensive program to ensure the survival and recovery of Columbia River chum salmon in its most productive system and builds on existing recovery planning efforts for these ESA-listed salmonids within the Grays River and the lower Columbia River. This assessment also provides a basis for the recovery of other fish species in the Grays River, including coho salmon, winter steelhead, coastal cutthroat trout, and Pacific lamprey.« less

Voxel-based morphometry and automated lobar volumetry: The trade-off between spatial scale and statistical correction

PubMed Central

Voormolen, Eduard H.J.; Wei, Corie; Chow, Eva W.C.; Bassett, Anne S.; Mikulis, David J.; Crawley, Adrian P.

2011-01-01

Voxel-based morphometry (VBM) and automated lobar region of interest (ROI) volumetry are comprehensive and fast methods to detect differences in overall brain anatomy on magnetic resonance images. However, VBM and automated lobar ROI volumetry have detected dissimilar gray matter differences within identical image sets in our own experience and in previous reports. To gain more insight into how diverging results arise and to attempt to establish whether one method is superior to the other, we investigated how differences in spatial scale and in the need to statistically correct for multiple spatial comparisons influence the relative sensitivity of either technique to group differences in gray matter volumes. We assessed the performance of both techniques on a small dataset containing simulated gray matter deficits and additionally on a dataset of 22q11-deletion syndrome patients with schizophrenia (22q11DS-SZ) vs. matched controls. VBM was more sensitive to simulated focal deficits compared to automated ROI volumetry, and could detect global cortical deficits equally well. Moreover, theoretical calculations of VBM and ROI detection sensitivities to focal deficits showed that at increasing ROI size, ROI volumetry suffers more from loss in sensitivity than VBM. Furthermore, VBM and automated ROI found corresponding GM deficits in 22q11DS-SZ patients, except in the parietal lobe. Here, automated lobar ROI volumetry found a significant deficit only after a smaller subregion of interest was employed. Thus, sensitivity to focal differences is impaired relatively more by averaging over larger volumes in automated ROI methods than by the correction for multiple comparisons in VBM. These findings indicate that VBM is to be preferred over automated lobar-scale ROI volumetry for assessing gray matter volume differences between groups. PMID:19619660

Overview of the physics of US.

PubMed

Goldstein, A

1993-05-01

In ultrasonography (US), high-frequency sound waves are transmitted through the body by a transducer. When a transmitted ultrasound pulse encounters a tissue target, some of its energy is deflected back to the transducer. The time of flight of this ultrasound echo is used to calculate depth of the target in the transducer beam. The pulse-echo parameters used in the formation of images include echo amplitude, target spatial position, and frequency shift between the transmitted pulse and the received echo. The first two are displayed in gray-scale images and all three in color flow images. In gray-scale US, echo amplitude is encoded into shades of gray, with the lighter shades representing higher amplitude echoes. In color flow US, velocity of moving blood is usually presented in blue for motion toward the transducer and in red for motion away from it. A Doppler spectrum depicts changing blood velocity as a function of time. US has become more clinically valuable due to its ability to demonstrate soft-tissue structures, real-time imaging capability, relative safety, portability, and cost-effectiveness.

The faintest speck of dirt: disgust enhances the detection of impurity.

PubMed

Sherman, Gary D; Haidt, Jonathan; Clore, Gerald L

2012-12-01

Purity is commonly regarded as being physically embodied in the color white, with even trivial deviations from whiteness indicating a loss of purity. In three studies, we explored the implications of this "white = pure" association for disgust, an emotion that motivates the detection and avoidance of impurities that threaten purity and cleanliness. We hypothesized that disgust tunes perception to prioritize the light end of the light-dark spectrum, which results in a relative hypersensitivity to changes in lightness in this range. In studies 1 and 2, greater sensitivity to disgusting stimuli was associated with greater ability to make subtle gray-scale discriminations (e.g., detecting a faint gray stimulus against a white background) at the light end of the spectrum relative to ability to make subtle gray-scale discriminations at the dark end of the spectrum. In study 3, after viewing disgusting images, disgust-sensitive individuals demonstrated a heightened ability to detect deviations from white. These findings suggest that disgust not only motivates people to avoid impurities, but actually makes them better able to see them.

SU-E-I-100: Heterogeneity Studying for Primary and Lymphoma Tumors by Using Multi-Scale Image Texture Analysis with PET-CT Images

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Dengwang; Wang, Qinfen; Li, H

Purpose: The purpose of this research is studying tumor heterogeneity of the primary and lymphoma by using multi-scale texture analysis with PET-CT images, where the tumor heterogeneity is expressed by texture features. Methods: Datasets were collected from 12 lung cancer patients, and both of primary and lymphoma tumors were detected with all these patients. All patients underwent whole-body 18F-FDG PET/CT scan before treatment.The regions of interest (ROI) of primary and lymphoma tumor were contoured by experienced clinical doctors. Then the ROI of primary and lymphoma tumor is extracted automatically by using Matlab software. According to the geometry size of contourmore » structure, the images of tumor are decomposed by multi-scale method.Wavelet transform was performed on ROI structures within images by L layers sampling, and then wavelet sub-bands which have the same size of the original image are obtained. The number of sub-bands is 3L+1.The gray level co-occurrence matrix (GLCM) is calculated within different sub-bands, thenenergy, inertia, correlation and gray in-homogeneity were extracted from GLCM.Finally, heterogeneity statistical analysis was studied for primary and lymphoma tumor using the texture features. Results: Energy, inertia, correlation and gray in-homogeneity are calculated with our experiments for heterogeneity statistical analysis.Energy for primary and lymphomatumor is equal with the same patient, while gray in-homogeneity and inertia of primaryare 2.59595±0.00855, 0.6439±0.0007 respectively. Gray in-homogeneity and inertia of lymphoma are 2.60115±0.00635, 0.64435±0.00055 respectively. The experiments showed that the volume of lymphoma is smaller than primary tumor, but thegray in-homogeneity and inertia were higher than primary tumor with the same patient, and the correlation with lymphoma tumors is zero, while the correlation with primary tumor isslightly strong. Conclusion: This studying showed that there were effective heterogeneity differences between primary and lymphoma tumor by multi-scale image texture analysis. This work is supported by National Natural Science Foundation of China (No. 61201441), Research Fund for Excellent Young and Middle-aged Scientists of Shandong Province (No. BS2012DX038), Project of Shandong Province Higher Educational Science and Technology Program (No. J12LN23), Jinan youth science and technology star (No.20120109)« less

A cross-sectional and follow-up voxel-based morphometric MRI study in adolescent anorexia nervosa.

PubMed

Castro-Fornieles, Josefina; Bargalló, Nuria; Lázaro, Luisa; Andrés, Susana; Falcon, Carles; Plana, Maria Teresa; Junqué, Carme

2009-01-01

The objective was to examine whether cerebral volumes are reduced, and in what regions, in adolescents with anorexia nervosa and to study changes after nutritional recovery. Twelve anorexia nervosa (DSM-IV) patients aged 11-17 consecutively admitted to an Eating Disorders Unit were assessed by means of psychopathological scales, neuropsychological battery and voxel-based morphometric (VBM) magnetic resonance imaging at admission and after 7 months' follow-up. Nine control subjects of similar age, gender and estimated intelligence level were also studied. The two groups showed differences in gray matter (F=22.2; p<0.001) and cerebrospinal fluid (CSF) (F=21.2; p<0.001) but not in white matter volumes. In anorexic patients, gray matter volume correlated negatively with the copy time from the Rey Complex Figure Test. In the regional VBM study several temporal and parietal gray matter regions were reduced. During follow-up there was a greater global increase in gray matter (F=10.7; p=0.004) and decrease in CSF (F=22.1; p=0.001) in anorexic patients. The increase in gray matter correlated with a decrease in cortisol (Spearman correlation=-0.73; p=0.017). At follow-up there were no differences in global gray matter (F=2.1; p=0.165), white matter (F=0.02, p=0.965) or CSF (F=1.8; p=0.113) volumes between both groups. There were still some smaller areas, in the right temporal and both supplementary motor area, showing differences between them in the regional VBM study. In conclusion, in adolescent anorexic patients gray matter is more affected than white matter and mainly involves the posterior regions of the brain. Overall gray matter alterations are reversible after nutritional recovery.

Sonoelastography in the Evaluation of Plantar Fasciitis Treatment: 3-Month Follow-Up After Collagen Injection.

PubMed

Kim, Minchul; Choi, Yun Sun; You, Myung-Won; Kim, Jin Su; Young, Ki Won

2016-12-01

The aim of this study was to investigate whether ultrasound elastography can demonstrate the outcome of the treatment in comparison with gray-scale imaging. Sixteen patients (mean age, 46.9 years) with plantar fasciitis were prospectively enrolled after unsuccessful conservative treatment. Individuals graded their heel pain on a 100-mm visual analogue scale (VAS) and underwent gray-scale ultrasonography and sonoelastography. Collagen was injected in the heels. Fascial thickness and hypoechogenicity, perifascial edema, and plantar fascial elasticity were evaluated. Follow-up sonoelastography and VAS grading were done 3 months after the injection. Statistical analyses were performed by the paired t test and the Fisher exact test. A P < 0.05 was considered statistically significant. Mean plantar fascial thickness showed insignificant decrease on follow-up (from 4.30 [1.37] to 4.23 [1.15] mm, P = 0.662). Fascial hypoechogenicity and perifascial edema did not change significantly after treatment. The mean strain ratio of the plantar fascia was significantly increased (from 0.71 [0.24] to 1.66 [0.72], P = 0.001). Softening of the plantar fascia decreased significantly after injection (from 12 to 3 ft, P = 0.004). Twelve (75%) of 16 patients showed significant VAS improvement at the follow-up. Sonoelastography revealed a hardening of the plantar fascia after collagen injection treatment and could aid in monitoring the improvement of the symptoms of plantar fasciitis, in cases where gray-scale imaging is inconclusive.

SU-F-R-36: Validating Quantitative Radiomic Texture Features for Oncologic PET: A Digital Phantom Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, F; Yang, Y; Young, L

Purpose: Radiomic texture features derived from the oncologic PET have recently been brought under intense investigation within the context of patient stratification and treatment outcome prediction in a variety of cancer types; however, their validity has not yet been examined. This work is aimed to validate radiomic PET texture metrics through the use of realistic simulations in the ground truth setting. Methods: Simulation of FDG-PET was conducted by applying the Zubal phantom as an attenuation map to the SimSET software package that employs Monte Carlo techniques to model the physical process of emission imaging. A total of 15 irregularly-shaped lesionsmore » featuring heterogeneous activity distribution were simulated. For each simulated lesion, 28 texture features in relation to the intensity histograms (GLIH), grey-level co-occurrence matrices (GLCOM), neighborhood difference matrices (GLNDM), and zone size matrices (GLZSM) were evaluated and compared with their respective values extracted from the ground truth activity map. Results: In reference to the values from the ground truth images, texture parameters appearing on the simulated data varied with a range of 0.73–3026.2% for GLIH-based, 0.02–100.1% for GLCOM-based, 1.11–173.8% for GLNDM-based, and 0.35–66.3% for GLZSM-based. For majority of the examined texture metrics (16/28), their values on the simulated data differed significantly from those from the ground truth images (P-value ranges from <0.0001 to 0.04). Features not exhibiting significant difference comprised of GLIH-based standard deviation, GLCO-based energy and entropy, GLND-based coarseness and contrast, and GLZS-based low gray-level zone emphasis, high gray-level zone emphasis, short zone low gray-level emphasis, long zone low gray-level emphasis, long zone high gray-level emphasis, and zone size nonuniformity. Conclusion: The extent to which PET imaging disturbs texture appearance is feature-dependent and could be substantial. It is thus advised that use of PET texture parameters for predictive and prognostic measurements in oncologic setting awaits further systematic and critical evaluation.« less

Changes in lactate dehydrogenase are associated with central gray matter lesions in newborns with hypoxic-ischemic encephalopathy.

PubMed

Yum, Sook Kyung; Moon, Cheong-Jun; Youn, Young-Ah; Sung, In Kyung

2017-05-01

Biomarkers may predict neurological prognosis in infants with hypoxic-ischemic encephalopathy (HIE). We evaluated the relationship between serum lactate dehydrogenase (LDH) and brain magnetic resonance imaging (MRI), which predicts neurodevelopmental outcomes, in order to assess whether LDH levels are similarly predictive. Medical records were reviewed for infants with HIE and LDH levels were assessed on the first (LDH 1 ) and third (LDH 3 ) days following birth. Receiver operating characteristic curves were obtained in relation to central gray matter hypoxic-ischemic lesions. Of 92 patients, 52 (56.5%) had hypoxic-ischemic lesions on brain MRI, and 21 of these infants (40.4%) had central gray matter lesions. LDH 1 and LDH 3 did not differ; however, the percentage change (ΔLDH%) was significantly higher in infants with central gray matter lesions (36.9% versus 6.6%, p = 0.006). With cutoffs of 187 (IU/L, ΔLDH) and 19.4 (%, ΔLDH%), the sensitivity, specificity, positive predictive value and negative predictive value were 71.4, 69.0, 40.5 and 89.1%, respectively. The relative risk was 5.57 (p = 0.001). Changes in serum LDH may be a useful biomarker for predicting future neurodevelopmental prognosis in infants with HIE.

Weighted sum of gray gases model optimization for numerical investigations of processes inside pulverized coal-fired furnaces

NASA Astrophysics Data System (ADS)

Crnomarkovic, Nenad; Belosevic, Srdjan; Tomanovic, Ivan; Milicevic, Aleksandar

2017-12-01

The effects of the number of significant figures (NSF) in the interpolation polynomial coefficients (IPCs) of the weighted sum of gray gases model (WSGM) on results of numerical investigations and WSGM optimization were investigated. The investigation was conducted using numerical simulations of the processes inside a pulverized coal-fired furnace. The radiative properties of the gas phase were determined using the simple gray gas model (SG), two-term WSGM (W2), and three-term WSGM (W3). Ten sets of the IPCs with the same NSF were formed for every weighting coefficient in both W2 and W3. The average and maximal relative difference values of the flame temperatures, wall temperatures, and wall heat fluxes were determined. The investigation showed that the results of numerical investigations were affected by the NSF unless it exceeded certain value. The increase in the NSF did not necessarily lead to WSGM optimization. The combination of the NSF (CNSF) was the necessary requirement for WSGM optimization.

[Accuracy of computer aided measurement for detecting dental proximal caries lesions in images of cone-beam computed tomography].

PubMed

Zhang, Z L; Li, J P; Li, G; Ma, X C

2017-02-09

Objective: To establish and validate a computer program used to aid the detection of dental proximal caries in the images cone beam computed tomography (CBCT) images. Methods: According to the characteristics of caries lesions in X-ray images, a computer aided detection program for proximal caries was established with Matlab and Visual C++. The whole process for caries lesion detection included image import and preprocessing, measuring average gray value of air area, choosing region of interest and calculating gray value, defining the caries areas. The program was used to examine 90 proximal surfaces from 45 extracted human teeth collected from Peking University School and Hospital of Stomatology. The teeth were then scanned with a CBCT scanner (Promax 3D). The proximal surfaces of the teeth were respectively detected by caries detection program and scored by human observer for the extent of lesions with 6-level-scale. With histologic examination serving as the reference standard, the caries detection program and the human observer performances were assessed with receiver operating characteristic (ROC) curves. Student t -test was used to analyze the areas under the ROC curves (AUC) for the differences between caries detection program and human observer. Spearman correlation coefficient was used to analyze the detection accuracy of caries depth. Results: For the diagnosis of proximal caries in CBCT images, the AUC values of human observers and caries detection program were 0.632 and 0.703, respectively. There was a statistically significant difference between the AUC values ( P= 0.023). The correlation between program performance and gold standard (correlation coefficient r (s)=0.525) was higher than that of observer performance and gold standard ( r (s)=0.457) and there was a statistically significant difference between the correlation coefficients ( P= 0.000). Conclusions: The program that automatically detects dental proximal caries lesions could improve the diagnostic value of CBCT images.

Gray scale operation of a multichannel optical convolver using the Semetex magnetooptic spatial light modulator

NASA Technical Reports Server (NTRS)

Davis, Jeffrey A.; Day, Timothy; Lilly, Roger A.; Taber, Donald B.; Liu, Hua-Kuang

1988-01-01

A new multichannel optical correlator/convolver architecture which uses an acoustooptic light modulator for the input channel and a Semetex magnetooptic spatial light modulator (MOSLM) for the set of parallel reference channels is presented. Details of the anamorphic optical system are discussed. Experimental results illustrate the use of the system as a convolver for performing digital multiplication by analog convolution (DMAC). A limited gray scale capability for data stored by the MOSLM is demonstrated by implementing this DMAC algorithm with trinary logic. Use of the MOSLM allows the number of parallel channels for the convolver to be increased significantly compared with previously reported techniques while retaining the capability for updating both channels at high speeds.

Gray Scale Operation Of A Multichannel Optical Convolver Using The Semetex Magnetooptic Spatial Light Modulator

NASA Astrophysics Data System (ADS)

Davis, Jeffrey A.; Day, Timothy; Lilly, Roger A.; Taber, Donald B.; Liu, Hua-Kuang; Davis, J. A.; Day, T.; Lilly, R. A.; Taber, D. B.; Liu, H.-K.

1988-02-01

We present a new multichannel optical correlator/convolver architecture which uses an acoustooptic light modulator (AOLM) for the input channel and a Semetex magnetooptic spatial light modulator (MOSLM) for the set of parallel reference channels. Details of the anamorphic optical system are discussed. Experimental results illustrate use of the system as a convolver for performing digital multiplication by analog convolution (DMAC). A limited gray scale capability for data stored by the MOSLM is demonstrated by implementing this DMAC algorithm with trinary logic. Use of the MOSLM allows the number of parallel channels for the convolver to be increased significantly compared with previously reported techniques while retaining the capability for updating both channels at high speeds.

Gray scale operation of a multichannel optical convolver using the Semetex magnetooptic spatial light modulator

NASA Astrophysics Data System (ADS)

Davis, Jeffrey A.; Day, Timothy; Lilly, Roger A.; Taber, Donald B.; Liu, Hua-Kuang

A new multichannel optical correlator/convolver architecture which uses an acoustooptic light modulator for the input channel and a Semetex magnetooptic spatial light modulator (MOSLM) for the set of parallel reference channels is presented. Details of the anamorphic optical system are discussed. Experimental results illustrate the use of the system as a convolver for performing digital multiplication by analog convolution (DMAC). A limited gray scale capability for data stored by the MOSLM is demonstrated by implementing this DMAC algorithm with trinary logic. Use of the MOSLM allows the number of parallel channels for the convolver to be increased significantly compared with previously reported techniques while retaining the capability for updating both channels at high speeds.

Comparison of gray matter volume and thickness for analysis of cortical changes in Alzheimer's disease

NASA Astrophysics Data System (ADS)

Liu, Jiachao; Li, Ziyi; Chen, Kewei; Yao, Li; Wang, Zhiqun; Li, Kunchen; Guo, Xiaojuan

2011-03-01

Gray matter volume and cortical thickness are two indices of concern in brain structure magnetic resonance imaging research. Gray matter volume reflects mixed-measurement information of cerebral cortex, while cortical thickness reflects only the information of distance between inner surface and outer surface of cerebral cortex. Using Scaled Subprofile Modeling based on Principal Component Analysis (SSM_PCA) and Pearson's Correlation Analysis, this study further provided quantitative comparisons and depicted both global relevance and local relevance to comprehensively investigate morphometrical abnormalities in cerebral cortex in Alzheimer's disease (AD). Thirteen patients with AD and thirteen age- and gender-matched healthy controls were included in this study. Results showed that factor scores from the first 8 principal components accounted for ~53.38% of the total variance for gray matter volume, and ~50.18% for cortical thickness. Factor scores from the fifth principal component showed significant correlation. In addition, gray matter voxel-based volume was closely related to cortical thickness alterations in most cortical cortex, especially, in some typical abnormal brain regions such as insula and the parahippocampal gyrus in AD. These findings suggest that these two measurements are effective indices for understanding the neuropathology in AD. Studies using both gray matter volume and cortical thickness can separate the causes of the discrepancy, provide complementary information and carry out a comprehensive description of the morphological changes of brain structure.

Accuracy of Liver Fat Quantification With Advanced CT, MRI, and Ultrasound Techniques: Prospective Comparison With MR Spectroscopy.

PubMed

Kramer, Harald; Pickhardt, Perry J; Kliewer, Mark A; Hernando, Diego; Chen, Guang-Hong; Zagzebski, James A; Reeder, Scott B

2017-01-01

The purpose of this study was to prospectively evaluate the accuracy of proton-density fat-fraction, single- and dual-energy CT (SECT and DECT), gray-scale ultrasound (US), and US shear-wave elastography (US-SWE) in the quantification of hepatic steatosis with MR spectroscopy (MRS) as the reference standard. Fifty adults who did not have symptoms (23 men, 27 women; mean age, 57 ± 5 years; body mass index, 27 ± 5) underwent liver imaging with un-enhanced SECT, DECT, gray-scale US, US-SWE, proton-density fat-fraction MRI, and MRS for this prospective trial. MRS voxels for the reference standard were colocalized with all other modalities under investigation. For SECT (120 kVp), attenuation values were recorded. For rapid-switching DECT (80/140 kVp), monochromatic images (70-140 keV) and fat density-derived material decomposition images were reconstructed. For proton-density fat fraction MRI, a quantitative chemical shift-encoded method was used. For US, echogenicity was evaluated on a qualitative 0-3 scale. Quantitative US shear-wave velocities were also recorded. Data were analyzed by linear regression for each technique compared with MRS. There was excellent correlation between MRS and both proton-density fat-fraction MRI (r 2 = 0.992; slope, 0.974; intercept, -0.943) and SECT (r 2 = 0.856; slope, -0.559; intercept, 35.418). DECT fat attenuation had moderate correlation with MRS measurements (r 2 = 0.423; slope, 0.034; intercept, 8.459). There was good correlation between qualitative US echogenicity and MRS measurements with a weighted kappa value of 0.82. US-SWE velocity did not have reliable correlation with MRS measurements (r 2 = 0.004; slope, 0.069; intercept, 6.168). Quantitative MRI proton-density fat fraction and SECT fat attenuation have excellent linear correlation with MRS measurements and can serve as accurate noninvasive biomarkers for quantifying steatosis. Material decomposition with DECT does not improve the accuracy of fat quantification over conventional SECT attenuation. US-SWE has poor accuracy for liver fat quantification.

Robust image watermarking using DWT and SVD for copyright protection

NASA Astrophysics Data System (ADS)

Harjito, Bambang; Suryani, Esti

2017-02-01

The Objective of this paper is proposed a robust combined Discrete Wavelet Transform (DWT) and Singular Value Decomposition (SVD). The RGB image is called a cover medium, and watermark image is converted into gray scale. Then, they are transformed using DWT so that they can be split into several subbands, namely sub-band LL2, LH2, HL2. The watermark image embeds into the cover medium on sub-band LL2. This scheme aims to obtain the higher robustness level than the previous method which performs of SVD matrix factorization image for copyright protection. The experiment results show that the proposed method has robustness against several image processing attacks such as Gaussian, Poisson and Salt and Pepper Noise. In these attacks, noise has average Normalized Correlation (NC) values of 0.574863 0.889784, 0.889782 respectively. The watermark image can be detected and extracted.

Regional gray matter atrophy in relapsing remitting multiple sclerosis: baseline analysis of multi-center data.

PubMed

Datta, Sushmita; Staewen, Terrell D; Cofield, Stacy S; Cutter, Gary R; Lublin, Fred D; Wolinsky, Jerry S; Narayana, Ponnada A

2015-03-01

Regional gray matter (GM) atrophy in multiple sclerosis (MS) at disease onset and its temporal variation can provide objective information regarding disease evolution. An automated pipeline for estimating atrophy of various GM structures was developed using tensor based morphometry (TBM) and implemented on a multi-center sub-cohort of 1008 relapsing remitting MS (RRMS) patients enrolled in a Phase 3 clinical trial. Four hundred age and gender matched healthy controls were used for comparison. Using the analysis of covariance, atrophy differences between MS patients and healthy controls were assessed on a voxel-by-voxel analysis. Regional GM atrophy was observed in a number of deep GM structures that included thalamus, caudate nucleus, putamen, and cortical GM regions. General linear regression analysis was performed to analyze the effects of age, gender, and scanner field strength, and imaging sequence on the regional atrophy. Correlations between regional GM volumes and expanded disability status scale (EDSS) scores, disease duration (DD), T2 lesion load (T2 LL), T1 lesion load (T1 LL), and normalized cerebrospinal fluid (nCSF) were analyzed using Pearson׳s correlation coefficient. Thalamic atrophy observed in MS patients compared to healthy controls remained consistent within subgroups based on gender and scanner field strength. Weak correlations between thalamic volume and EDSS (r=-0.133; p<0.001) and DD (r=-0.098; p=0.003) were observed. Of all the structures, thalamic volume moderately correlated with T2 LL (r=-0.492; P-value<0.001), T1 LL (r=-0.473; P-value<0.001) and nCSF (r=-0.367; P-value<0.001). Copyright © 2015 Elsevier B.V. All rights reserved.

Anterior cruciate ligament tears treated with percutaneous injection of autologous bone marrow nucleated cells: a case series

PubMed Central

Centeno, Christopher J; Pitts, John; Al-Sayegh, Hasan; Freeman, Michael D

2015-01-01

Introduction This was a prospective case series designed to investigate treatment for anterior cruciate ligament (ACL) tears using an injection of autologous bone marrow concentrate. Methods Consecutive adult patients presenting to a private outpatient interventional musculoskeletal and pain practice with knee pain, ACL laxity on exam, and magnetic resonance imaging (MRI) evidence of a grade 1, 2, or 3 ACL tears with less than 1 cm retraction were eligible for this study. Eligible patients were treated with an intraligamentous injection of autologous bone marrow concentrate, using fluoroscopic guidance. Pre- and postprocedural sagittal MRI images of the ACLs were analyzed using ImageJ software to objectively quantify changes between pre- and posttreatment scans. Five different types of measurement of ACL pixel intensity were examined as a proxy for ligament integrity. In addition pain visual analog scale (VAS) and Lower Extremity Functional Scale (LEFS) values were recorded at baseline and at 1 month, 3 months, 6 months, and annually postinjection. Objective outcomes measured were pre- to post-MRI measurement changes, as analyzed by the ImageJ software. Subjective outcomes measured were changes in the VAS and LEFS, and a self-rated percentage improvement. Results Seven of ten patients showed improvement in at least four of five objective measures of ACL integrity in their postprocedure MRIs. In the entire study group, the mean gray value, median, raw integrated density, and modal gray value all decreased toward low-signal ACLs (P=0.01, P=0.02, P=0.002, and P=0.08), indications of improved ligament integrity. Seven of ten patients responded to the self-rated metrics follow up. The mean VAS change was a decrease of 1.7 (P=0.25), the mean LEFS change was an increase of 23.3 (P=0.03), and mean reported improvement was 86.7%. Conclusion Based on this small case series, autologous bone marrow concentrate shows promise in the treatment of grade 1, 2, and possibly grade 3 ACL tears without retraction. Further investigation using a controlled study design is warranted. PMID:26261424

Alexithymia in Neurodegenerative Disease

PubMed Central

Sturm, Virginia E.; Levenson, Robert W.

2012-01-01

We investigated alexithymia, a deficit in the ability to identify and describe one’s emotions, in a sample that included patients with neurodegenerative disease and healthy controls. In addition, we investigated the relationship that alexithymia has with behavioral disturbance and with regional gray matter volumes. Alexithymia was examined with the Toronto Alexithymia Scale-20, behavioral disturbance was assessed with the Neuropsychiatric Inventory, and regional gray matter volumes were obtained from structural magnetic resonance images. Group analyses revealed higher levels of alexithymia in patients than controls. Alexithymia scores were positively correlated with behavioral disturbance (apathy and informant distress, in particular) and negatively correlated with the gray matter volume of the right pregenual anterior cingulate cortex, a region of the brain that is thought to play an important role in self and emotion processing. PMID:21432723

Geographical Influences of an Emerging Network of Gang Rivalries

DTIC Science & Technology

2011-03-17

Hollenbeck in the N × M environment grid. The semi-permeable boundaries encoded in the model are displayed in the center image. The shades of gray of...intensity. Light shades of gray correspond to high density values near one and dark shades correspond to low densities near zero. The boundary crossing...Threshold Graphs ( GTG ) For comparison to the networks produced by our simulations, we constructed an instance of a Geograph- ical Threshold Graph ( GTG

Opto-acoustic breast imaging with co-registered ultrasound

NASA Astrophysics Data System (ADS)

Zalev, Jason; Clingman, Bryan; Herzog, Don; Miller, Tom; Stavros, A. Thomas; Oraevsky, Alexander; Kist, Kenneth; Dornbluth, N. Carol; Otto, Pamela

2014-03-01

We present results from a recent study involving the ImagioTM breast imaging system, which produces fused real-time two-dimensional color-coded opto-acoustic (OA) images that are co-registered and temporally inter- leaved with real-time gray scale ultrasound using a specialized duplex handheld probe. The use of dual optical wavelengths provides functional blood map images of breast tissue and tumors displayed with high contrast based on total hemoglobin and oxygen saturation of the blood. This provides functional diagnostic information pertaining to tumor metabolism. OA also shows morphologic information about tumor neo-vascularity that is complementary to the morphological information obtained with conventional gray scale ultrasound. This fusion technology conveniently enables real-time analysis of the functional opto-acoustic features of lesions detected by readers familiar with anatomical gray scale ultrasound. We demonstrate co-registered opto-acoustic and ultrasonic images of malignant and benign tumors from a recent clinical study that provide new insight into the function of tumors in-vivo. Results from the Feasibility Study show preliminary evidence that the technology may have the capability to improve characterization of benign and malignant breast masses over conventional diagnostic breast ultrasound alone and to improve overall accuracy of breast mass diagnosis. In particular, OA improved speci city over that of conventional diagnostic ultrasound, which could potentially reduce the number of negative biopsies performed without missing cancers.

Mapping gray-scale image to 3D surface scanning data by ray tracing

NASA Astrophysics Data System (ADS)

Li, Peng; Jones, Peter R. M.

1997-03-01

The extraction and location of feature points from range imaging is an important but difficult task in machine vision based measurement systems. There exist some feature points which are not able to be detected from pure geometric characteristics, particularly in those measurement tasks related to the human body. The Loughborough Anthropometric Shadow Scanner (LASS) is a whole body surface scanner based on structured light technique. Certain applications of LASS require accurate location of anthropometric landmarks from the scanned data. This is sometimes impossible from existing raw data because some landmarks do not appear in the scanned data. Identification of these landmarks has to resort to surface texture of the scanned object. Modifications to LASS were made to allow gray-scale images to be captured before or after the object was scanned. Two-dimensional gray-scale image must be mapped to the scanned data to acquire the 3D coordinates of a landmark. The method to map 2D images to the scanned data is based on the colinearity conditions and ray-tracing method. If the camera center and image coordinates are known, the corresponding object point must lie on a ray starting from the camera center and connecting to the image coordinate. By intersecting the ray with the scanned surface of the object, the 3D coordinates of a point can be solved. Experimentation has demonstrated the feasibility of the method.

Dark and Bright Terrains of Pluto

NASA Image and Video Library

2015-07-10

These circular maps shows the distribution of Pluto's dark and bright terrains as revealed by NASA's New Horizons mission prior to July 4, 2015. Each map is an azimuthal equidistant projection centered on the north pole, with latitude and longitude indicated. Both a gray-scale and color version are shown. The gray-scale version is based on 7 days of panchromatic imaging from the Long Range Reconnaissance Imager (LORRI), whereas the color version uses the gray-scale base and incorporates lower-resolution color information from the Multi-spectral Visible Imaging Camera (MVIC), part of the Ralph instrument. The color version is also shown in a simple cylindrical projection in PIA19700. In these maps, the polar bright terrain is surrounded by a somewhat darker polar fringe, one whose latitudinal position varies strongly with longitude. Especially striking are the much darker regions along the equator. A broad dark swath ("the whale") stretches along the equator from approximately 20 to 160 degrees of longitude. Several dark patches appear in a regular sequence centered near 345 degrees of longitude. A spectacular bright region occupies Pluto's mid-latitudes near 180 degrees of longitude, and stretches southward over the equator. New Horizons' closest approach to Pluto will occur near this longitude, which will permit high-resolution visible imaging and compositional mapping of these various regions. http://photojournal.jpl.nasa.gov/catalog/PIA19706

Rain-shadow: An area harboring "Gray Ocean" clouds

NASA Astrophysics Data System (ADS)

Padmakumari, B.; Maheskumar, R. S.; Harikishan, G.; Morwal, S. B.; Kulkarni, J. R.

2018-06-01

The characteristics of monsoon convective clouds over the rain-shadow region of north peninsular India have been investigated using in situ aircraft cloud microphysical observations collected during Cloud Aerosol Interaction and Precipitation Enhancement EXperiment (CAIPEEX). The parameters considered for characterization are: liquid water content (LWC), cloud vertical motion (updraft, downdraft: w), cloud droplet number concentration (CDNC) and effective radius (Re). The results are based on 15 research flights which were conducted from the base station Hyderabad during summer monsoon season. The clouds studied were developing congestus. The clouds have low CDNC and low updraft values resembling the oceanic convective clouds. The super-saturation in clouds is found to be low (≤0.2%) due to low updrafts. The land surface behaves like ocean surface during monsoon as deduced from Bowen ratio. Microphysically the clouds showed oceanic characteristics. However, these clouds yield low rainfall due to their low efficiency (mean 14%). The cloud parameters showed a large variability; hence their characteristic values are reported in terms of median values. These values will serve the numerical models for rainfall simulations over the region and also will be useful as a scientific basis for cloud seeding operations to increase the rainfall efficiency. The study revealed that monsoon convective clouds over the rain-shadow region are of oceanic type over the gray land, and therefore we christen them as "Gray Ocean" clouds.

Entropy-Based Adaptive Nuclear Texture Features are Independent Prognostic Markers in a Total Population of Uterine Sarcomas

PubMed Central

Nielsen, Birgitte; Hveem, Tarjei Sveinsgjerd; Kildal, Wanja; Abeler, Vera M; Kristensen, Gunnar B; Albregtsen, Fritz; Danielsen, Håvard E; Rohde, Gustavo K

2015-01-01

Nuclear texture analysis measures the spatial arrangement of the pixel gray levels in a digitized microscopic nuclear image and is a promising quantitative tool for prognosis of cancer. The aim of this study was to evaluate the prognostic value of entropy-based adaptive nuclear texture features in a total population of 354 uterine sarcomas. Isolated nuclei (monolayers) were prepared from 50 µm tissue sections and stained with Feulgen-Schiff. Local gray level entropy was measured within small windows of each nuclear image and stored in gray level entropy matrices, and two superior adaptive texture features were calculated from each matrix. The 5-year crude survival was significantly higher (P < 0.001) for patients with high texture feature values (72%) than for patients with low feature values (36%). When combining DNA ploidy classification (diploid/nondiploid) and texture (high/low feature value), the patients could be stratified into three risk groups with 5-year crude survival of 77, 57, and 34% (Hazard Ratios (HR) of 1, 2.3, and 4.1, P < 0.001). Entropy-based adaptive nuclear texture was an independent prognostic marker for crude survival in multivariate analysis including relevant clinicopathological features (HR = 2.1, P = 0.001), and should therefore be considered as a potential prognostic marker in uterine sarcomas. © The Authors. Published 2014 International Society for Advancement of Cytometry PMID:25483227

Application of gray level mapping in computed tomographic colonography: a pilot study to compare with traditional surface rendering method for identification and differentiation of endoluminal lesions

PubMed Central

Chen, Lih-Shyang; Hsu, Ta-Wen; Chang, Shu-Han; Lin, Chih-Wen; Chen, Yu-Ruei; Hsieh, Chin-Chiang; Han, Shu-Chen; Chang, Ku-Yaw; Hou, Chun-Ju

2017-01-01

Objective: In traditional surface rendering (SR) computed tomographic endoscopy, only the shape of endoluminal lesion is depicted without gray-level information unless the volume rendering technique is used. However, volume rendering technique is relatively slow and complex in terms of computation time and parameter setting. We use computed tomographic colonography (CTC) images as examples and report a new visualization technique by three-dimensional gray level mapping (GM) to better identify and differentiate endoluminal lesions. Methods: There are 33 various endoluminal cases from 30 patients evaluated in this clinical study. These cases were segmented using gray-level threshold. The marching cube algorithm was used to detect isosurfaces in volumetric data sets. GM is applied using the surface gray level of CTC. Radiologists conducted the clinical evaluation of the SR and GM images. The Wilcoxon signed-rank test was used for data analysis. Results: Clinical evaluation confirms GM is significantly superior to SR in terms of gray-level pattern and spatial shape presentation of endoluminal cases (p < 0.01) and improves the confidence of identification and clinical classification of endoluminal lesions significantly (p < 0.01). The specificity and diagnostic accuracy of GM is significantly better than those of SR in diagnostic performance evaluation (p < 0.01). Conclusion: GM can reduce confusion in three-dimensional CTC and well correlate CTC with sectional images by the location as well as gray-level value. Hence, GM increases identification and differentiation of endoluminal lesions, and facilitates diagnostic process. Advances in knowledge: GM significantly improves the traditional SR method by providing reliable gray-level information for the surface points and is helpful in identification and differentiation of endoluminal lesions according to their shape and density. PMID:27925483

Multi-sensor image registration based on algebraic projective invariants.

PubMed

Li, Bin; Wang, Wei; Ye, Hao

2013-04-22

A new automatic feature-based registration algorithm is presented for multi-sensor images with projective deformation. Contours are firstly extracted from both reference and sensed images as basic features in the proposed method. Since it is difficult to design a projective-invariant descriptor from the contour information directly, a new feature named Five Sequential Corners (FSC) is constructed based on the corners detected from the extracted contours. By introducing algebraic projective invariants, we design a descriptor for each FSC that is ensured to be robust against projective deformation. Further, no gray scale related information is required in calculating the descriptor, thus it is also robust against the gray scale discrepancy between the multi-sensor image pairs. Experimental results utilizing real image pairs are presented to show the merits of the proposed registration method.

A psychophysical comparison of two methods for adaptive histogram equalization.

PubMed

Zimmerman, J B; Cousins, S B; Hartzell, K M; Frisse, M E; Kahn, M G

1989-05-01

Adaptive histogram equalization (AHE) is a method for adaptive contrast enhancement of digital images. It is an automatic, reproducible method for the simultaneous viewing of contrast within a digital image with a large dynamic range. Recent experiments have shown that in specific cases, there is no significant difference in the ability of AHE and linear intensity windowing to display gray-scale contrast. More recently, a variant of AHE which limits the allowed contrast enhancement of the image has been proposed. This contrast-limited adaptive histogram equalization (CLAHE) produces images in which the noise content of an image is not excessively enhanced, but in which sufficient contrast is provided for the visualization of structures within the image. Images processed with CLAHE have a more natural appearance and facilitate the comparison of different areas of an image. However, the reduced contrast enhancement of CLAHE may hinder the ability of an observer to detect the presence of some significant gray-scale contrast. In this report, a psychophysical observer experiment was performed to determine if there is a significant difference in the ability of AHE and CLAHE to depict gray-scale contrast. Observers were presented with computed tomography (CT) images of the chest processed with AHE and CLAHE. Subtle artificial lesions were introduced into some images. The observers were asked to rate their confidence regarding the presence of the lesions; this rating-scale data was analyzed using receiver operating characteristic (ROC) curve techniques. These ROC curves were compared for significant differences in the observers' performances. In this report, no difference was found in the abilities of AHE and CLAHE to depict contrast information.

Connectivity-driven white matter scaling and folding in primate cerebral cortex

PubMed Central

Herculano-Houzel, Suzana; Mota, Bruno; Kaas, Jon H.

2010-01-01

Larger brains have an increasingly folded cerebral cortex whose white matter scales up faster than the gray matter. Here we analyze the cellular composition of the subcortical white matter in 11 primate species, including humans, and one Scandentia, and show that the mass of the white matter scales linearly across species with its number of nonneuronal cells, which is expected to be proportional to the total length of myelinated axons in the white matter. This result implies that the average axonal cross-section area in the white matter, a, does not scale significantly with the number of neurons in the gray matter, N. The surface area of the white matter increases with N0.87, not N1.0. Because this surface can be defined as the product of N, a, and the fraction n of cortical neurons connected through the white matter, we deduce that connectivity decreases in larger cerebral cortices as a slowly diminishing fraction of neurons, which varies with N−0.16, sends myelinated axons into the white matter. Decreased connectivity is compatible with previous suggestions that neurons in the cerebral cortex are connected as a small-world network and should slow down the increase in global conduction delay in cortices with larger numbers of neurons. Further, a simple model shows that connectivity and cortical folding are directly related across species. We offer a white matter-based mechanism to account for increased cortical folding across species, which we propose to be driven by connectivity-related tension in the white matter, pulling down on the gray matter. PMID:20956290

Autographic theme extraction

USGS Publications Warehouse

Edson, D.; Colvocoresses, Alden P.

1973-01-01

Remote-sensor images, including aerial and space photographs, are generally recorded on film, where the differences in density create the image of the scene. With panchromatic and multiband systems the density differences are recorded in shades of gray. On color or color infrared film, with the emulsion containing dyes sensitive to different wavelengths, a color image is created by a combination of color densities. The colors, however, can be separated by filtering or other techniques, and the color image reduced to monochromatic images in which each of the separated bands is recorded as a function of the gray scale.

New MR imaging assessment tool to define brain abnormalities in very preterm infants at term.

PubMed

Kidokoro, H; Neil, J J; Inder, T E

2013-01-01

WM injury is the dominant form of injury in preterm infants. However, other cerebral structures, including the deep gray matter and the cerebellum, can also be affected by injury and/or impaired growth. Current MR imaging injury assessment scales are subjective and are challenging to apply. Thus, we developed a new assessment tool and applied it to MR imaging studies obtained from very preterm infants at term age. MR imaging scans from 97 very preterm infants (< 30 weeks' gestation) and 22 healthy term-born infants were evaluated retrospectively. The severity of brain injury (defined by signal abnormalities) and impaired brain growth (defined with biometrics) was scored in the WM, cortical gray matter, deep gray matter, and cerebellum. Perinatal variables for clinical risks were collected. In very preterm infants, brain injury was observed in the WM (n=23), deep GM (n=5), and cerebellum (n=23). Combining measures of injury and impaired growth showed moderate to severe abnormalities most commonly in the WM (n=38) and cerebellum (n=32) but still notable in the cortical gray matter (n=16) and deep gray matter (n=11). WM signal abnormalities were associated with a reduced deep gray matter area but not with cerebellar abnormality. Intraventricular and/or parenchymal hemorrhage was associated with cerebellar signal abnormality and volume reduction. Multiple clinical risk factors, including prolonged intubation, prolonged parenteral nutrition, postnatal corticosteroid use, and postnatal sepsis, were associated with increased global abnormality on MR imaging. Very preterm infants demonstrate a high prevalence of injury and growth impairment in both the WM and gray matter. This MR imaging scoring system provides a more comprehensive and objective classification of the nature and extent of abnormalities than existing measures.

Optical classification for quality and defect analysis of train brakes

NASA Astrophysics Data System (ADS)

Glock, Stefan; Hausmann, Stefan; Gerke, Sebastian; Warok, Alexander; Spiess, Peter; Witte, Stefan; Lohweg, Volker

2009-06-01

In this paper we present an optical measurement system approach for quality analysis of brakes which are used in high-speed trains. The brakes consist of the so called brake discs and pads. In a deceleration process the discs will be heated up to 500°C. The quality measure is based on the fact that the heated brake discs should not generate hot spots inside the brake material. Instead, the brake disc should be heated homogeneously by the deceleration. Therefore, it makes sense to analyze the number of hot spots and their relative gradients to create a quality measure for train brakes. In this contribution we present a new approach for a quality measurement system which is based on an image analysis and classification of infra-red based heat images. Brake images which are represented in pseudo-color are first transformed in a linear grayscale space by a hue-saturation-intensity (HSI) space. This transform is necessary for the following gradient analysis which is based on gray scale gradient filters. Furthermore, different features based on Haralick's measures are generated from the gray scale and gradient images. A following Fuzzy-Pattern-Classifier is used for the classification of good and bad brakes. It has to be pointed out that the classifier returns a score value for each brake which is between 0 and 100% good quality. This fact guarantees that not only good and bad bakes can be distinguished, but also their quality can be labeled. The results show that all critical thermal patterns of train brakes can be sensed and verified.

High-efficiency control of gray mold by the novel SDHI fungicide benzovindiflupyr combined with a reasonable application approach of dipping flower.

PubMed

He, Leiming; Cui, Kaidi; Song, Yufei; Mu, Wei; Liu, Feng

2018-06-11

ABSTRACT：In this study, a novel succinate dehydrogenase inhibitor (SDHI) fungicide benzovindiflupyr was found to have strong inhibitory activity against gray mold caused by Botrytis cinerea. The sensitivity of B. cinerea to benzovindiflupyr was determined by testing 103 pathogen isolates with mean values of 2.15 ± 0.19 mg liter-1 and 0.89 ± 0.14 mg liter-1 for mycelial growth and spore germination inhibition, respectively. Furthermore, benzovindiflupyr had excellent long-lasting protective activity. Unfortunately, there were positive correlations between benzovindiflupyr and boscalid (r=0.3, P=0.04) and between benzovindiflupyr and isopyrazam (r=0.31, P=0.04). In the field, cucumber flowers are susceptible to infection by B. cinerea. Benzovindiflupyr applied at 20 mg liter-1 by dipping flower could successfully control cucumber gray mold, with the benzovindiflupyr dose of dipping flower application less than 1% of that of spraying application. Benzovindiflupyr combined with dipping flower application showed significant control of gray mold.

Quantification technology study on flaws in steam-filled pipelines based on image processing

NASA Astrophysics Data System (ADS)

Sun, Lina; Yuan, Peixin

2009-07-01

Starting from exploiting the applied detection system of gas transmission pipeline, a set of X-ray image processing methods and pipeline flaw quantificational evaluation methods are proposed. Defective and non-defective strings and rows in gray image were extracted and oscillogram was obtained. We can distinguish defects in contrast with two gray images division. According to the gray value of defects with different thicknesses, the gray level depth curve is founded. Through exponential and polynomial fitting way to obtain the attenuation mathematical model which the beam penetrates pipeline, thus attain flaw deep dimension. This paper tests on the PPR pipe in the production of simulated holes flaw and cracks flaw, 135KV used the X-ray source on the testing. Test results show that X-ray image processing method, which meet the needs of high efficient flaw detection and provide quality safeguard for thick oil recovery, can be used successfully in detecting corrosion of insulated pipe.

Quantification technology study on flaws in steam-filled pipelines based on image processing

NASA Astrophysics Data System (ADS)

Yuan, Pei-xin; Cong, Jia-hui; Chen, Bo

2008-03-01

Starting from exploiting the applied detection system of gas transmission pipeline, a set of X-ray image processing methods and pipeline flaw quantificational evaluation methods are proposed. Defective and non-defective strings and rows in gray image were extracted and oscillogram was obtained. We can distinguish defects in contrast with two gray images division. According to the gray value of defects with different thicknesses, the gray level depth curve is founded. Through exponential and polynomial fitting way to obtain the attenuation mathematical model which the beam penetrates pipeline, thus attain flaw deep dimension. This paper tests on the PPR pipe in the production of simulated holes flaw and cracks flaw. The X-ray source tube voltage was selected as 130kv and valve current was 1.5mA.Test results show that X-ray image processing methods, which meet the needs of high efficient flaw detection and provide quality safeguard for thick oil recovery, can be used successfully in detecting corrosion of insulated pipe.

Generative complexity of Gray-Scott model

NASA Astrophysics Data System (ADS)

Adamatzky, Andrew

2018-03-01

In the Gray-Scott reaction-diffusion system one reactant is constantly fed in the system, another reactant is reproduced by consuming the supplied reactant and also converted to an inert product. The rate of feeding one reactant in the system and the rate of removing another reactant from the system determine configurations of concentration profiles: stripes, spots, waves. We calculate the generative complexity-a morphological complexity of concentration profiles grown from a point-wise perturbation of the medium-of the Gray-Scott system for a range of the feeding and removal rates. The morphological complexity is evaluated using Shannon entropy, Simpson diversity, approximation of Lempel-Ziv complexity, and expressivity (Shannon entropy divided by space-filling). We analyse behaviour of the systems with highest values of the generative morphological complexity and show that the Gray-Scott systems expressing highest levels of the complexity are composed of the wave-fragments (similar to wave-fragments in sub-excitable media) and travelling localisations (similar to quasi-dissipative solitons and gliders in Conway's Game of Life).

Simulation of speckle patterns with pre-defined correlation distributions.

PubMed

Song, Lipei; Zhou, Zhen; Wang, Xueyan; Zhao, Xing; Elson, Daniel S

2016-03-01

We put forward a method to easily generate a single or a sequence of fully developed speckle patterns with pre-defined correlation distribution by utilizing the principle of coherent imaging. The few-to-one mapping between the input correlation matrix and the correlation distribution between simulated speckle patterns is realized and there is a simple square relationship between the values of these two correlation coefficient sets. This method is demonstrated both theoretically and experimentally. The square relationship enables easy conversion from any desired correlation distribution. Since the input correlation distribution can be defined by a digital matrix or a gray-scale image acquired experimentally, this method provides a convenient way to simulate real speckle-related experiments and to evaluate data processing techniques.

[Research on non-rigid registration of multi-modal medical image based on Demons algorithm].

PubMed

Hao, Peibo; Chen, Zhen; Jiang, Shaofeng; Wang, Yang

2014-02-01

Non-rigid medical image registration is a popular subject in the research areas of the medical image and has an important clinical value. In this paper we put forward an improved algorithm of Demons, together with the conservation of gray model and local structure tensor conservation model, to construct a new energy function processing multi-modal registration problem. We then applied the L-BFGS algorithm to optimize the energy function and solve complex three-dimensional data optimization problem. And finally we used the multi-scale hierarchical refinement ideas to solve large deformation registration. The experimental results showed that the proposed algorithm for large de formation and multi-modal three-dimensional medical image registration had good effects.

Simulation of speckle patterns with pre-defined correlation distributions

PubMed Central

Song, Lipei; Zhou, Zhen; Wang, Xueyan; Zhao, Xing; Elson, Daniel S.

2016-01-01

We put forward a method to easily generate a single or a sequence of fully developed speckle patterns with pre-defined correlation distribution by utilizing the principle of coherent imaging. The few-to-one mapping between the input correlation matrix and the correlation distribution between simulated speckle patterns is realized and there is a simple square relationship between the values of these two correlation coefficient sets. This method is demonstrated both theoretically and experimentally. The square relationship enables easy conversion from any desired correlation distribution. Since the input correlation distribution can be defined by a digital matrix or a gray-scale image acquired experimentally, this method provides a convenient way to simulate real speckle-related experiments and to evaluate data processing techniques. PMID:27231589

Research and implementation of finger-vein recognition algorithm

NASA Astrophysics Data System (ADS)

Pang, Zengyao; Yang, Jie; Chen, Yilei; Liu, Yin

2017-06-01

In finger vein image preprocessing, finger angle correction and ROI extraction are important parts of the system. In this paper, we propose an angle correction algorithm based on the centroid of the vein image, and extract the ROI region according to the bidirectional gray projection method. Inspired by the fact that features in those vein areas have similar appearance as valleys, a novel method was proposed to extract center and width of palm vein based on multi-directional gradients, which is easy-computing, quick and stable. On this basis, an encoding method was designed to determine the gray value distribution of texture image. This algorithm could effectively overcome the edge of the texture extraction error. Finally, the system was equipped with higher robustness and recognition accuracy by utilizing fuzzy threshold determination and global gray value matching algorithm. Experimental results on pairs of matched palm images show that, the proposed method has a EER with 3.21% extracts features at the speed of 27ms per image. It can be concluded that the proposed algorithm has obvious advantages in grain extraction efficiency, matching accuracy and algorithm efficiency.

Serum biochemistry of captive and free-ranging gray wolves (Canis lupus)

USGS Publications Warehouse

Constable, Peter; Hinchcliff, Ken; Demma, Nick; Callahan, Margaret; Dale, B.W.; Fox, Kevin; Adams, Layne G.; Wack, Ray; Kramer, Lynn

1998-01-01

Normal serum biochemistry values are frequently obtained from studies of captive sedentary (zoo) or free-ranging (wild) animals. It is frequently assumed that values from these two populations are directly referable to each other. We tested this assumption using 20 captive gray wolves (Canis lupus) in Minnesota, USA, and 11 free-ranging gray wolves in Alaska, USA. Free-ranging wolves had significantly (P<0.05) lower sodium, chloride, and creatine concentrations and significantly higher potassium and blood urea nitrogen (BUN) concentrations; BUN to creatine ratios; and alanine aminotransferase, aspartate aminotransferase, and creatine kinase activities relative to captive wolves. Corticosteroid-induced alkaline phosphatase activity (a marker of stress in domestic dogs) was detected in 3 of 11 free-ranging wolves and in 0 of 20 captive wolves (P = 0.037). This study provides clear evidence that serum biochemical differences can exist between captive and free-ranging populations of one species. Accordingly, evaluation of the health status of an animal should incorporate an understanding of the potential confounding effect that nutrition, activity level, and environmental stress could have on the factor(s) being measured.

Relationship between brain R(2) and liver and serum iron concentrations in elderly men.

PubMed

House, Michael J; St Pierre, Timothy G; Milward, Elizabeth A; Bruce, David G; Olynyk, John K

2010-02-01

Studies of iron overload in humans and animals suggest that brain iron concentrations may be related in a regionally specific way to body iron status. However, few quantitative studies have investigated the associations between peripheral and regional brain iron in a normal elderly cohort. To examine these relationships, we used MRI to measure the proton transverse relaxation rate (R(2)) in 13 gray and white matter brain regions in 18 elderly men (average age, 75.5 years) with normal cognition. Brain R(2) values were compared with liver iron concentrations measured using the FerriScan MRI technique and serum iron indices. R(2) values in high-iron gray matter regions were significantly correlated (positively) with liver iron concentrations (globus pallidus, ventral pallidum) and serum transferrin saturation (caudate nucleus, globus pallidus, putamen) measured concurrently with brain R(2), and with serum iron concentrations (caudate nucleus, globus pallidus) measured three years before the current study. Our results suggest that iron levels in specific gray matter brain regions are influenced by systemic iron status in elderly men.

Fully-integrated framework for the segmentation and registration of the spinal cord white and gray matter.

PubMed

Dupont, Sara M; De Leener, Benjamin; Taso, Manuel; Le Troter, Arnaud; Nadeau, Sylvie; Stikov, Nikola; Callot, Virginie; Cohen-Adad, Julien

2017-04-15

The spinal cord white and gray matter can be affected by various pathologies such as multiple sclerosis, amyotrophic lateral sclerosis or trauma. Being able to precisely segment the white and gray matter could help with MR image analysis and hence be useful in further understanding these pathologies, and helping with diagnosis/prognosis and drug development. Up to date, white/gray matter segmentation has mostly been done manually, which is time consuming, induces a bias related to the rater and prevents large-scale multi-center studies. Recently, few methods have been proposed to automatically segment the spinal cord white and gray matter. However, no single method exists that combines the following criteria: (i) fully automatic, (ii) works on various MRI contrasts, (iii) robust towards pathology and (iv) freely available and open source. In this study we propose a multi-atlas based method for the segmentation of the spinal cord white and gray matter that addresses the previous limitations. Moreover, to study the spinal cord morphology, atlas-based approaches are increasingly used. These approaches rely on the registration of a spinal cord template to an MR image, however the registration usually doesn't take into account the spinal cord internal structure and thus lacks accuracy. In this study, we propose a new template registration framework that integrates the white and gray matter segmentation to account for the specific gray matter shape of each individual subject. Validation of segmentation was performed in 24 healthy subjects using T 2 * -weighted images, in 8 healthy subjects using diffusion weighted images (exhibiting inverted white-to-gray matter contrast compared to T 2 *-weighted), and in 5 patients with spinal cord injury. The template registration was validated in 24 subjects using T 2 *-weighted data. Results of automatic segmentation on T 2 *-weighted images was in close correspondence with the manual segmentation (Dice coefficient in the white/gray matter of 0.91/0.71 respectively). Similarly, good results were obtained in data with inverted contrast (diffusion-weighted image) and in patients. When compared to the classical template registration framework, the proposed framework that accounts for gray matter shape significantly improved the quality of the registration (comparing Dice coefficient in gray matter: p=9.5×10 -6 ). While further validation is needed to show the benefits of the new registration framework in large cohorts and in a variety of patients, this study provides a fully-integrated tool for quantitative assessment of white/gray matter morphometry and template-based analysis. All the proposed methods are implemented in the Spinal Cord Toolbox (SCT), an open-source software for processing spinal cord multi-parametric MRI data. Copyright © 2017 Elsevier Inc. All rights reserved.

Migrations of California gray whales tracked by oxygen-18 variations in their epizoic barnacles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Killingley, J.S.

1980-02-15

Barnacles attached to the California gray whale have oxygen isotope compositions that serve as a record of changing ocean temperatures as the whale migrates between arctic and subtropical waters. The isotopic values for the barnacles can be used to track whale migrations and to reconstruct the recent movements of beached whales. The method may be useful for tracing the movements of other animals, living or fossil, and for reconstructing the voyages of ancient ships.

Image Description with Local Patterns: An Application to Face Recognition

NASA Astrophysics Data System (ADS)

Zhou, Wei; Ahrary, Alireza; Kamata, Sei-Ichiro

In this paper, we propose a novel approach for presenting the local features of digital image using 1D Local Patterns by Multi-Scans (1DLPMS). We also consider the extentions and simplifications of the proposed approach into facial images analysis. The proposed approach consists of three steps. At the first step, the gray values of pixels in image are represented as a vector giving the local neighborhood intensity distrubutions of the pixels. Then, multi-scans are applied to capture different spatial information on the image with advantage of less computation than other traditional ways, such as Local Binary Patterns (LBP). The second step is encoding the local features based on different encoding rules using 1D local patterns. This transformation is expected to be less sensitive to illumination variations besides preserving the appearance of images embedded in the original gray scale. At the final step, Grouped 1D Local Patterns by Multi-Scans (G1DLPMS) is applied to make the proposed approach computationally simpler and easy to extend. Next, we further formulate boosted algorithm to extract the most discriminant local features. The evaluated results demonstrate that the proposed approach outperforms the conventional approaches in terms of accuracy in applications of face recognition, gender estimation and facial expression.

Relationship between aging and T1 relaxation time in deep gray matter: A voxel-based analysis.

PubMed

Okubo, Gosuke; Okada, Tomohisa; Yamamoto, Akira; Fushimi, Yasutaka; Okada, Tsutomu; Murata, Katsutoshi; Togashi, Kaori

2017-09-01

To investigate age-related changes in T 1 relaxation time in deep gray matter structures in healthy volunteers using magnetization-prepared 2 rapid acquisition gradient echoes (MP2RAGE). In all, 70 healthy volunteers (aged 20-76, mean age 42.6 years) were scanned at 3T magnetic resonance imaging (MRI). A MP2RAGE sequence was employed to quantify T 1 relaxation times. After the spatial normalization of T 1 maps with the diffeomorphic anatomical registration using the exponentiated Lie algebra algorithm, voxel-based regression analysis was conducted. In addition, linear and quadratic regression analyses of regions of interest (ROIs) were also performed. With aging, voxel-based analysis (VBA) revealed significant T 1 value decreases in the ventral-inferior putamen, nucleus accumbens, and amygdala, whereas T 1 values significantly increased in the thalamus and white matter as well (P < 0.05 at cluster level, false discovery rate). ROI analysis revealed that T 1 values in the nucleus accumbens linearly decreased with aging (P = 0.0016), supporting the VBA result. T 1 values in the thalamus (P < 0.0001), substantia nigra (P = 0.0003), and globus pallidus (P < 0.0001) had a best fit to quadratic curves, with the minimum T 1 values observed between 30 and 50 years of age. Age-related changes in T 1 relaxation time vary by location in deep gray matter. 2 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:724-731. © 2017 International Society for Magnetic Resonance in Medicine.

Effect of field-of-view size on gray values derived from cone-beam computed tomography compared with the Hounsfield unit values from multidetector computed tomography scans.

PubMed

Shokri, Abbas; Ramezani, Leila; Bidgoli, Mohsen; Akbarzadeh, Mahdi; Ghazikhanlu-Sani, Karim; Fallahi-Sichani, Hamed

2018-03-01

This study aimed to evaluate the effect of field-of-view (FOV) size on the gray values derived from conebeam computed tomography (CBCT) compared with the Hounsfield unit values from multidetector computed tomography (MDCT) scans as the gold standard. A radiographic phantom was designed with 4 acrylic cylinders. One cylinder was filled with distilled water, and the other 3 were filled with 3 types of bone substitute: namely, Nanobone, Cenobone, and Cerabone. The phantom was scanned with 2 CBCT systems using 2 different FOV sizes, and 1 MDCT system was used as the gold standard. The mean gray values (MGVs) of each cylinder were calculated in each imaging protocol. In both CBCT systems, significant differences were noted in the MGVs of all materials between the 2 FOV sizes ( P <.05) except for Cerabone in the Cranex3D system. Significant differences were found in the MGVs of each material compared with the others in both FOV sizes for each CBCT system. No significant difference was seen between the Cranex3D CBCT system and the MDCT system in the MGVs of bone substitutes on images obtained with a small FOV. The size of the FOV significantly changed the MGVs of all bone substitutes, except for Cerabone in the Cranex3D system. Both CBCT systems had the ability to distinguish the 3 types of bone substitutes based on a comparison of their MGVs. The Cranex3D CBCT system used with a small FOV had a significant correlation with MDCT results.

Dimensionless, Scale Invariant, Edge Weight Metric for the Study of Complex Structural Networks

PubMed Central

Colon-Perez, Luis M.; Spindler, Caitlin; Goicochea, Shelby; Triplett, William; Parekh, Mansi; Montie, Eric; Carney, Paul R.; Price, Catherine; Mareci, Thomas H.

2015-01-01

High spatial and angular resolution diffusion weighted imaging (DWI) with network analysis provides a unique framework for the study of brain structure in vivo. DWI-derived brain connectivity patterns are best characterized with graph theory using an edge weight to quantify the strength of white matter connections between gray matter nodes. Here a dimensionless, scale-invariant edge weight is introduced to measure node connectivity. This edge weight metric provides reasonable and consistent values over any size scale (e.g. rodents to humans) used to quantify the strength of connection. Firstly, simulations were used to assess the effects of tractography seed point density and random errors in the estimated fiber orientations; with sufficient signal-to-noise ratio (SNR), edge weight estimates improve as the seed density increases. Secondly to evaluate the application of the edge weight in the human brain, ten repeated measures of DWI in the same healthy human subject were analyzed. Mean edge weight values within the cingulum and corpus callosum were consistent and showed low variability. Thirdly, using excised rat brains to study the effects of spatial resolution, the weight of edges connecting major structures in the temporal lobe were used to characterize connectivity in this local network. The results indicate that with adequate resolution and SNR, connections between network nodes are characterized well by this edge weight metric. Therefore this new dimensionless, scale-invariant edge weight metric provides a robust measure of network connectivity that can be applied in any size regime. PMID:26173147

Dimensionless, Scale Invariant, Edge Weight Metric for the Study of Complex Structural Networks.

PubMed

Colon-Perez, Luis M; Spindler, Caitlin; Goicochea, Shelby; Triplett, William; Parekh, Mansi; Montie, Eric; Carney, Paul R; Price, Catherine; Mareci, Thomas H

2015-01-01

High spatial and angular resolution diffusion weighted imaging (DWI) with network analysis provides a unique framework for the study of brain structure in vivo. DWI-derived brain connectivity patterns are best characterized with graph theory using an edge weight to quantify the strength of white matter connections between gray matter nodes. Here a dimensionless, scale-invariant edge weight is introduced to measure node connectivity. This edge weight metric provides reasonable and consistent values over any size scale (e.g. rodents to humans) used to quantify the strength of connection. Firstly, simulations were used to assess the effects of tractography seed point density and random errors in the estimated fiber orientations; with sufficient signal-to-noise ratio (SNR), edge weight estimates improve as the seed density increases. Secondly to evaluate the application of the edge weight in the human brain, ten repeated measures of DWI in the same healthy human subject were analyzed. Mean edge weight values within the cingulum and corpus callosum were consistent and showed low variability. Thirdly, using excised rat brains to study the effects of spatial resolution, the weight of edges connecting major structures in the temporal lobe were used to characterize connectivity in this local network. The results indicate that with adequate resolution and SNR, connections between network nodes are characterized well by this edge weight metric. Therefore this new dimensionless, scale-invariant edge weight metric provides a robust measure of network connectivity that can be applied in any size regime.

Cerebral blood flow with [15O]water PET studies using an image-derived input function and MR-defined carotid centerlines

NASA Astrophysics Data System (ADS)

Fung, Edward K.; Carson, Richard E.

2013-03-01

Full quantitative analysis of brain PET data requires knowledge of the arterial input function into the brain. Such data are normally acquired by arterial sampling with corrections for delay and dispersion to account for the distant sampling site. Several attempts have been made to extract an image-derived input function (IDIF) directly from the internal carotid arteries that supply the brain and are often visible in brain PET images. We have devised a method of delineating the internal carotids in co-registered magnetic resonance (MR) images using the level-set method and applying the segmentations to PET images using a novel centerline approach. Centerlines of the segmented carotids were modeled as cubic splines and re-registered in PET images summed over the early portion of the scan. Using information from the anatomical center of the vessel should minimize partial volume and spillover effects. Centerline time-activity curves were taken as the mean of the values for points along the centerline interpolated from neighboring voxels. A scale factor correction was derived from calculation of cerebral blood flow (CBF) using gold standard arterial blood measurements. We have applied the method to human subject data from multiple injections of [15O]water on the HRRT. The method was assessed by calculating the area under the curve (AUC) of the IDIF and the CBF, and comparing these to values computed using the gold standard arterial input curve. The average ratio of IDIF to arterial AUC (apparent recovery coefficient: aRC) across 9 subjects with multiple (n = 69) injections was 0.49 ± 0.09 at 0-30 s post tracer arrival, 0.45 ± 0.09 at 30-60 s, and 0.46 ± 0.09 at 60-90 s. Gray and white matter CBF values were 61.4 ± 11.0 and 15.6 ± 3.0 mL/min/100 g tissue using sampled blood data. Using IDIF centerlines scaled by the average aRC over each subjects’ injections, gray and white matter CBF values were 61.3 ± 13.5 and 15.5 ± 3.4 mL/min/100 g tissue. Using global average aRC values, the means were unchanged, and intersubject variability was noticeably reduced. This MR-based centerline method with local re-registration to [15O]water PET yields a consistent IDIF over multiple injections in the same subject, thus permitting the absolute quantification of CBF without arterial input function measurements.

A new scoring model for characterization of adnexal masses based on two-dimensional gray-scale and colour Doppler sonographic features

PubMed Central

Abbas, A.M.; Zahran, K.M.; Nasr, A.; Kamel, H.S.

2014-01-01

Objective: To determine the most discriminating two-dimensional gray-scale and colour Doppler sonographic features that allow differentiation between malignant and benign adnexal masses, and to develop a scoring model that would enable more accurate diagnosis with those features. Methods: A cross sectional prospective study was conducted on patients scheduled for surgery due to presence of adnexal masses at Woman’s Health Center, Assiut University, Egypt between October 2012 and October 2013. All patients were evaluated by 2D ultrasound for morphological features of the masses combined with colour Doppler examination of their vessels. The final diagnosis, based on histopathological analysis, was used as a gold standard. Results: One hundred forty-six patients were recruited, 104 with benign masses, 42 with malignant masses. Features that allowed statistically significant discrimination of benignity from malignancy were; volume of mass, type of mass, presence and thickness of septae, presence and length of papillary projections, location of vessels at colour Doppler and colour score. A scoring model was formulated combining these features together; Assiut Scoring Model (ASM). The cut-off level with the highest accuracy in detection of malignancy, was ≥6, had a sensitivity of 93.5% and specificity of 92.2%. Conclusion: Our Scoring Model; a multiparameter scoring using four gray-scale ultrasound and two colour Doppler features, had shown a high sensitivity and specificity for prediction of malignancy in adnexal masses compared with previous scoring systems. PMID:25009729

Effect of resin infiltration on white spot lesions after debonding orthodontic brackets.

PubMed

Hammad, Shaza M; El Banna, Mai; El Zayat, Inas; Mohsen, Mohamed Abdel

2012-02-01

To evaluate the effect of application of a resin infiltration material on masking the white spot lesions (WSLs) after bracket removal. 18 patients participated in this study and were divided into two groups of nine patients each; by a visual score based on the extent of demineralization, according to the classification of the WSLs. Group 1: Visible WSLs without surface disruption and Group 2: WSLs showed a roughened surface but not requiring restoration. Three successive photographs were taken for every patient; immediately after bracket removal, 1 week after oral hygiene measures and after Icon material application. The JPEG images were imported into image analysis software (Image J version 1.33u for Windows XP, US National Institutes of Health) which presented the images into histograms of gray scale from (0 to 255). Initial and final images were compared for percentage of WSLs masking area. For both groups, a statistically significant difference at P<0.05 was obtained as follows; for WSLs in Group 1, the means at gray scale for the initial and the final photographs were 126.091 +/- 13.452 and 221.268 +/- 9.350 respectively and they revealed significance by Wilcoxon's signed rank test = 0.038, P<0.05. For WSLs in Group 2, the means at gray scale for the initial and the final photographs were 95.585 +/- 20.973 and 155.612 +/- 31.203 respectively and they revealed significance by Wilcoxon's signed rank test = 0.029, P<0.05.

Fabrication of 3D surface structures using grayscale lithography

NASA Astrophysics Data System (ADS)

Stilson, Christopher; Pal, Rajan; Coutu, Ronald A.

2014-03-01

The ability to design and develop 3D microstructures is important for microelectromechanical systems (MEMS) fabrication. Previous techniques used to create 3D devices included tedious steps in direct writing and aligning patterns onto a substrate followed by multiple photolithography steps using expensive, customized equipment. Additionally, these techniques restricted batch processing and placed limits on achievable shapes. Gray-scale lithography enables the fabrication of a variety of shapes using a single photolithography step followed by reactive ion etching (RIE). Micromachining 3D silicon structures for MEMS can be accomplished using gray-scale lithography along with dry anisotropic etching. In this study, we investigated: using MATLAB for mask designs; feasibility of using 1 μm Heidelberg mask maker to direct write patterns onto photoresist; using RIE processing to etch patterns into a silicon substrate; and the ability to tailor etch selectivity for precise fabrication. To determine etch rates and to obtain desired etch selectivity, parameters such as gas mixture, gas flow, and electrode power were studied. This process successfully demonstrates the ability to use gray-scale lithography and RIE for use in the study of micro-contacts. These results were used to produce a known engineered non-planer surface for testing micro-contacts. Surface structures are between 5 μm and 20 μm wide with varying depths and slopes based on mask design and etch rate selectivity. The engineered surfaces will provide more insight into contact geometries and failure modes of fixed-fixed micro-contacts.

Example-Based Image Colorization Using Locality Consistent Sparse Representation.

PubMed

Bo Li; Fuchen Zhao; Zhuo Su; Xiangguo Liang; Yu-Kun Lai; Rosin, Paul L

2017-11-01

Image colorization aims to produce a natural looking color image from a given gray-scale image, which remains a challenging problem. In this paper, we propose a novel example-based image colorization method exploiting a new locality consistent sparse representation. Given a single reference color image, our method automatically colorizes the target gray-scale image by sparse pursuit. For efficiency and robustness, our method operates at the superpixel level. We extract low-level intensity features, mid-level texture features, and high-level semantic features for each superpixel, which are then concatenated to form its descriptor. The collection of feature vectors for all the superpixels from the reference image composes the dictionary. We formulate colorization of target superpixels as a dictionary-based sparse reconstruction problem. Inspired by the observation that superpixels with similar spatial location and/or feature representation are likely to match spatially close regions from the reference image, we further introduce a locality promoting regularization term into the energy formulation, which substantially improves the matching consistency and subsequent colorization results. Target superpixels are colorized based on the chrominance information from the dominant reference superpixels. Finally, to further improve coherence while preserving sharpness, we develop a new edge-preserving filter for chrominance channels with the guidance from the target gray-scale image. To the best of our knowledge, this is the first work on sparse pursuit image colorization from single reference images. Experimental results demonstrate that our colorization method outperforms the state-of-the-art methods, both visually and quantitatively using a user study.

Is incest common in gray wolf packs?

USGS Publications Warehouse

Smith, Deborah E; Meier, Thomas J.; Geffen, Eli; Mech, L. David; Burch, John W.; Adams, Layne G.; Wayne, Robert K.

1997-01-01

Wolf packs generally consist of a breeding pair and their maturing offspring that help provision and protect pack young. Because the reproductive tenure in wolves is often short, reproductively mature offspring might replace their parents, resulting in sibling or parent-offspring matings. To determine the extent of incestuous pairings, we measured relatedness based on variability in 20 microsatellite loci of mated pairs, parent-offspring pairs, and siblings in two populations of gray wolves. Our 16 sampled mated pairs had values of relatedness not overlapping those of known parent-offspring or sibling dyads, which is consistent with their being unrelated or distantly related. These results suggest that full siblings or a parent and its offspring rarely mate and that incest avoidance is an important constraint on gray wolf behavioral ecology.

Chapter 1.1 Process Scale-Up of Cellulose Nanocrystal Production to 25 kg per Batch at the Forest Products Laboratory

Treesearch

Richard S. Reiner; Alan W. Rudie

2013-01-01

The Fiber and Chemical Sciences Research Work Unit at the Forest Products Laboratory began working out the preparation of cellulose nanocrystals in 2006, using the method of Dong, Revol, and Gray. Initial samples were provided to several scientists within the Forest Service. Continued requests for this material forced scale-up from the initial 20 g scale to kg...

Genome-Wide Association Study to Identify Susceptibility Loci That Modify Radiation-Related Risk for Breast Cancer After Childhood Cancer.

PubMed

Morton, Lindsay M; Sampson, Joshua N; Armstrong, Gregory T; Chen, Ting-Huei; Hudson, Melissa M; Karlins, Eric; Dagnall, Casey L; Li, Shengchao Alfred; Wilson, Carmen L; Srivastava, Deo Kumar; Liu, Wei; Kang, Guolian; Oeffinger, Kevin C; Henderson, Tara O; Moskowitz, Chaya S; Gibson, Todd M; Merino, Diana M; Wong, Jeannette R; Hammond, Sue; Neglia, Joseph P; Turcotte, Lucie M; Miller, Jeremy; Bowen, Laura; Wheeler, William A; Leisenring, Wendy M; Whitton, John A; Burdette, Laurie; Chung, Charles; Hicks, Belynda D; Jones, Kristine; Machiela, Mitchell J; Vogt, Aurelie; Wang, Zhaoming; Yeager, Meredith; Neale, Geoffrey; Lear, Matthew; Strong, Louise C; Yasui, Yutaka; Stovall, Marilyn; Weathers, Rita E; Smith, Susan A; Howell, Rebecca; Davies, Stella M; Radloff, Gretchen A; Onel, Kenan; Berrington de González, Amy; Inskip, Peter D; Rajaraman, Preetha; Fraumeni, Joseph F; Bhatia, Smita; Chanock, Stephen J; Tucker, Margaret A; Robison, Leslie L

2017-11-01

Childhood cancer survivors treated with chest-directed radiotherapy have substantially elevated risk for developing breast cancer. Although genetic susceptibility to breast cancer in the general population is well studied, large-scale evaluation of breast cancer susceptibility after chest-directed radiotherapy for childhood cancer is lacking. We conducted a genome-wide association study of breast cancer in female survivors of childhood cancer, pooling two cohorts with detailed treatment data and systematic, long-term follow-up: the Childhood Cancer Survivor Study and St. Jude Lifetime Cohort. The study population comprised 207 survivors who developed breast cancer and 2774 who had not developed any subsequent neoplasm as of last follow-up. Genotyping and subsequent imputation yielded 16 958 466 high-quality variants for analysis. We tested associations in the overall population and in subgroups stratified by receipt of lower than 10 and 10 or higher gray breast radiation exposure. We report P values and pooled per-allele risk estimates from Cox proportional hazards regression models. All statistical tests were two-sided. Among survivors who received 10 or higher gray breast radiation exposure, a locus on 1q41 was associated with subsequent breast cancer risk (rs4342822, nearest gene PROX1 , risk allele frequency in control subjects [RAF controls ] = 0.46, hazard ratio = 1.92, 95% confidence interval = 1.49 to 2.44, P = 7.09 × 10 -9 ). Two rare variants also showed potentially promising associations (breast radiation ≥10 gray: rs74949440, 11q23, TAGLN , RAF controls = 0.02, P = 5.84 × 10 -8 ; <10 gray: rs17020562, 1q32.3, RPS6KC1 , RAF controls = 0.0005, P = 6.68 × 10 -8 ). Associations were restricted to these dose subgroups, with consistent findings in the two survivor cohorts. Our study provides strong evidence that germline genetics outside high-risk syndromes could modify the effect of radiation exposure on breast cancer risk after childhood cancer. Published by Oxford University Press 2017. This work is written by US Government employees and is in the public domain in the US.

Gray whale sightings in the Canadian Beaufort Sea, September 2014

NASA Astrophysics Data System (ADS)

Iwahara, Yuka; Fujiwara, Amane; Ito, Keizo; Miyashita, Kazushi; Mitani, Yoko

2016-06-01

Gray whales (Eschrichtius robustus) are distributed within the productive neritic and estuarine waters of the North Pacific Ocean, the Bering Sea, and adjacent waters of the Arctic Ocean. They migrate to high-latitude feeding grounds each spring. Their main feeding grounds in the Arctic include the Chirikov Basin, the northeastern Chukchi Sea from Pt. Hope to Cape Lisburne and Pt. Lay to Pt. Barrow, and the northwestern Chukchi Sea along the Chukotka coast. Although sightings are rare in the Canadian Beaufort Sea, we observed three gray whales in two groups in this area in September 2014. A mud plume was observed near one of the whales, suggesting the animal had been feeding. In the Alaskan Beaufort Sea, large-scale monitoring of the distributions of marine mammals has been continuously conducted since 1979; however, there has been less monitoring in the Canadian Beaufort Sea. Therefore, it is necessary to record opportunistic sightings, such as those described here.

Exploring the role of testosterone in the cerebellum link to neuroticism: From adolescence to early adulthood.

PubMed

Schutter, Dennis J L G; Meuwese, Rosa; Bos, Marieke G N; Crone, Eveline A; Peper, Jiska S

2017-04-01

Previous research has found an association between a smaller cerebellar volume and higher levels of neuroticism. The steroid hormone testosterone reduces stress responses and the susceptibility to negative mood. Together with in vitro studies showing a positive effect of testosterone on cerebellar gray matter volumes, we set out to explore the role of testosterone in the relation between cerebellar gray matter and neuroticism. Structural magnetic resonance imaging scans were acquired, and indices of neurotic personality traits were assessed by administering the depression and anxiety scale of the revised NEO personality inventory and Gray's behavioural avoidance in one hundred and forty-nine healthy volunteers between 12 and 27 years of age. Results demonstrated an inverse relation between total brain corrected cerebellar volumes and neurotic personality traits in adolescents and young adults. In males, higher endogenous testosterone levels were associated with lower scores on neurotic personality traits and larger cerebellar gray matter volumes. No such relations were observed in the female participants. Analyses showed that testosterone significantly mediated the relation between male cerebellar gray matter and measures of neuroticism. Our findings on the interrelations between endogenous testosterone, neuroticism and cerebellar morphology provide a cerebellum-oriented framework for the susceptibility to experience negative emotions and mood in adolescence and early adulthood. Copyright © 2017 Elsevier Ltd. All rights reserved.

Longitudinal changes in gray matter regions after cranial radiation and comparative analysis with whole body radiation: a DTI study.

PubMed

Watve, Apurva; Gupta, Mamta; Khushu, Subash; Rana, Poonam

2018-06-01

Radiation-induced white matter changes are well known and vastly studied. However, radiation-induced gray matter alterations are still a research question. In the present study, these changes were assessed in a longitudinal manner using Diffusion Tensor Imaging (DTI) and further compared for cranial and whole body radiation exposure. Male mice (C57BL/6) were irradiated with cranial or whole body radiation followed by DTI study at 7T animal MRI system during predose, subacute and early delayed phases of radiation sickness. Fractional anisotropy (FA) and mean diffusivity (MD) values were obtained from brain's gray matter regions. Decreased FA with increased MD was observed prominently in animals exposed to cranial radiation showing most changes at 8 months post irradiation. However, whole body radiation induced FA changes were mostly observed at 1 month post irradiation as compared to controls. The differential response after whole body and cranial irradiation observed in the study depicts that radiation exposure of 5 Gy could induce permanent alterations in gray matter regions prominently as observed in Caudoputamen region at all the time points. Thus, our study has bolstered the role of DTI to probe microstructural changes in gray matter regions of brain after radiation exposure.

Automatic image equalization and contrast enhancement using Gaussian mixture modeling.

PubMed

Celik, Turgay; Tjahjadi, Tardi

2012-01-01

In this paper, we propose an adaptive image equalization algorithm that automatically enhances the contrast in an input image. The algorithm uses the Gaussian mixture model to model the image gray-level distribution, and the intersection points of the Gaussian components in the model are used to partition the dynamic range of the image into input gray-level intervals. The contrast equalized image is generated by transforming the pixels' gray levels in each input interval to the appropriate output gray-level interval according to the dominant Gaussian component and the cumulative distribution function of the input interval. To take account of the hypothesis that homogeneous regions in the image represent homogeneous silences (or set of Gaussian components) in the image histogram, the Gaussian components with small variances are weighted with smaller values than the Gaussian components with larger variances, and the gray-level distribution is also used to weight the components in the mapping of the input interval to the output interval. Experimental results show that the proposed algorithm produces better or comparable enhanced images than several state-of-the-art algorithms. Unlike the other algorithms, the proposed algorithm is free of parameter setting for a given dynamic range of the enhanced image and can be applied to a wide range of image types.

Lunar textural analysis based on WAC-derived kilometer-scale roughness and entropy maps

NASA Astrophysics Data System (ADS)

Li, Bo; Wang, XueQiang; Zhang, Jiang; Chen, Jian; Ling, Zongcheng

2016-06-01

In general, textures are thought to be some complicated repeated patterns formed by elements, or primitives which are sorted in certain rules. Lunar surfaces record the interactions between its outside environment and itself, thus, based on high-resolution DEM model or image data, there are some topographic features which have different roughness and entropy values or signatures on lunar surfaces. Textures of lunar surfaces can help us to concentrate on typical topographic and photometric variations and reveal the relationships between obvious features (craters, impact basins, sinuous rilles (SRs) and ridges) with resurfacing processes on the Moon. In this paper, the term surface roughness is an expression of the variability of a topographic or photometric surface at kilometer scale, and the term entropy can characterize the variability inherent in a geological and topographic unit and evaluate the uncertainty of predictions made by a given geological process. We use the statistical moments of gray-level histograms in different-sized neighborhoods (e.g., 3, 5, 10, 20, 40 and 80 pixels) to compute the kilometer-scale roughness and entropy values, using the mosaic image from 70°N to 70°S obtained by Lunar Reconnaissance Orbiter (LRO) Wide Angle Camera (WAC). Large roughness and entropy signatures were only found in the larger scale maps, while the smallest 3-pixel scale map had more disorderly and unsystematic textures. According to the entropy values in 10-pixel scale entropy map, we made a frequency curve and categorized lunar surfaces into three types, shadow effects, maria and highlands. A 2D scatter plot of entropy versus roughness values was produced and we found that there were two point clusters corresponding to the highlands and maria, respectively. In the last, we compared the topographic and photometric signatures derived from Lunar Orbiter Laser Altimeter (LOLA) data and WAC mosaic image. On the lunar surfaces, the ridges have obvious multilevel topographic textures which are sensitive to the topographic changes, while the ejecta deposits of fresh craters appear obvious photometric textures which are sensitive to the brightness variations.

3-Dimensional quantitative detection of nanoparticle content in biological tissue samples after local cancer treatment

NASA Astrophysics Data System (ADS)

Rahn, Helene; Alexiou, Christoph; Trahms, Lutz; Odenbach, Stefan

2014-06-01

X-ray computed tomography is nowadays used for a wide range of applications in medicine, science and technology. X-ray microcomputed tomography (XμCT) follows the same principles used for conventional medical CT scanners, but improves the spatial resolution to a few micrometers. We present an example of an application of X-ray microtomography, a study of 3-dimensional biodistribution, as along with the quantification of nanoparticle content in tumoral tissue after minimally invasive cancer therapy. One of these minimal invasive cancer treatments is magnetic drug targeting, where the magnetic nanoparticles are used as controllable drug carriers. The quantification is based on a calibration of the XμCT-equipment. The developed calibration procedure of the X-ray-μCT-equipment is based on a phantom system which allows the discrimination between the various gray values of the data set. These phantoms consist of a biological tissue substitute and magnetic nanoparticles. The phantoms have been studied with XμCT and have been examined magnetically. The obtained gray values and nanoparticle concentration lead to a calibration curve. This curve can be applied to tomographic data sets. Accordingly, this calibration enables a voxel-wise assignment of gray values in the digital tomographic data set to nanoparticle content. Thus, the calibration procedure enables a 3-dimensional study of nanoparticle distribution as well as concentration.

Gray matter responsiveness to adaptive working memory training: a surface-based morphometry study

PubMed Central

Román, Francisco J.; Lewis, Lindsay B.; Chen, Chi-Hua; Karama, Sherif; Burgaleta, Miguel; Martínez, Kenia; Lepage, Claude; Jaeggi, Susanne M.; Evans, Alan C.; Kremen, William S.

2016-01-01

Here we analyze gray matter indices before and after completing a challenging adaptive cognitive training program based on the n-back task. The considered gray matter indices were cortical thickness (CT) and cortical surface area (CSA). Twenty-eight young women (age range 17–22 years) completed 24 training sessions over the course of 3 months (12 weeks, 24 sessions), showing expected performance improvements. CT and CSA values for the training group were compared with those of a matched control group. Statistical analyses were computed using a ROI framework defined by brain areas distinguished by their genetic underpinning. The interaction between group and time was analyzed. Middle temporal, ventral frontal, inferior parietal cortices, and pars opercularis were the regions where the training group showed conservation of gray matter with respect to the control group. These regions support working memory, resistance to interference, and inhibition. Furthermore, an interaction with baseline intelligence differences showed that the expected decreasing trend at the biological level for individuals showing relatively low intelligence levels at baseline was attenuated by the completed training. PMID:26701168

Image smoothing and enhancement via min/max curvature flow

NASA Astrophysics Data System (ADS)

Malladi, Ravikanth; Sethian, James A.

1996-03-01

We present a class of PDE-based algorithms suitable for a wide range of image processing applications. The techniques are applicable to both salt-and-pepper gray-scale noise and full- image continuous noise present in black and white images, gray-scale images, texture images and color images. At the core, the techniques rely on a level set formulation of evolving curves and surfaces and the viscosity in profile evolution. Essentially, the method consists of moving the isointensity contours in an image under curvature dependent speed laws to achieve enhancement. Compared to existing techniques, our approach has several distinct advantages. First, it contains only one enhancement parameter, which in most cases is automatically chosen. Second, the scheme automatically stops smoothing at some optimal point; continued application of the scheme produces no further change. Third, the method is one of the fastest possible schemes based on a curvature-controlled approach.

Clinical feasibility study of combined opto-acoustic and ultrasonic imaging modality providing coregistered functional and anatomical maps of breast tumors

NASA Astrophysics Data System (ADS)

Zalev, Jason; Clingman, Bryan; Smith, Remie J.; Herzog, Don; Miller, Tom; Stavros, A. Thomas; Ermilov, Sergey; Conjusteau, André; Tsyboulski, Dmitri; Oraevsky, Alexander A.; Kist, Kenneth; Dornbluth, N. C.; Otto, Pamela

2013-03-01

We report on findings from the clinical feasibility study of the ImagioTM. Breast Imaging System, which acquires two-dimensional opto-acoustic (OA) images co-registered with conventional ultrasound using a specialized duplex hand-held probe. Dual-wavelength opto-acoustic technology is used to generate parametric maps based upon total hemoglobin and its oxygen saturation in breast tissues. This may provide functional diagnostic information pertaining to tumor metabolism and microvasculature, which is complementary to morphological information obtained with conventional gray-scale ultrasound. We present co-registered opto-acoustic and ultrasonic images of malignant and benign tumors from a recent clinical feasibility study. The clinical results illustrate that the technology may have the capability to improve the efficacy of breast tumor diagnosis. In doing so, it may have the potential to reduce biopsies and to characterize cancers that were not seen well with conventional gray-scale ultrasound alone.

Wavelet/scalar quantization compression standard for fingerprint images

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brislawn, C.M.

1996-06-12

US Federal Bureau of Investigation (FBI) has recently formulated a national standard for digitization and compression of gray-scale fingerprint images. Fingerprints are scanned at a spatial resolution of 500 dots per inch, with 8 bits of gray-scale resolution. The compression algorithm for the resulting digital images is based on adaptive uniform scalar quantization of a discrete wavelet transform subband decomposition (wavelet/scalar quantization method). The FBI standard produces archival-quality images at compression ratios of around 15 to 1 and will allow the current database of paper fingerprint cards to be replaced by digital imagery. The compression standard specifies a class ofmore » potential encoders and a universal decoder with sufficient generality to reconstruct compressed images produced by any compliant encoder, allowing flexibility for future improvements in encoder technology. A compliance testing program is also being implemented to ensure high standards of image quality and interchangeability of data between different implementations.« less

Information extraction from multivariate images

NASA Technical Reports Server (NTRS)

Park, S. K.; Kegley, K. A.; Schiess, J. R.

1986-01-01

An overview of several multivariate image processing techniques is presented, with emphasis on techniques based upon the principal component transformation (PCT). Multiimages in various formats have a multivariate pixel value, associated with each pixel location, which has been scaled and quantized into a gray level vector, and the bivariate of the extent to which two images are correlated. The PCT of a multiimage decorrelates the multiimage to reduce its dimensionality and reveal its intercomponent dependencies if some off-diagonal elements are not small, and for the purposes of display the principal component images must be postprocessed into multiimage format. The principal component analysis of a multiimage is a statistical analysis based upon the PCT whose primary application is to determine the intrinsic component dimensionality of the multiimage. Computational considerations are also discussed.

Real-time single image dehazing based on dark channel prior theory and guided filtering

NASA Astrophysics Data System (ADS)

Zhang, Zan

2017-10-01

Images and videos taken outside the foggy day are serious degraded. In order to restore degraded image taken in foggy day and overcome traditional Dark Channel prior algorithms problems of remnant fog in edge, we propose a new dehazing method.We first find the fog area in the dark primary color map to obtain the estimated value of the transmittance using quadratic tree. Then we regard the gray-scale image after guided filtering as atmospheric light map and remove haze based on it. Box processing and image down sampling technology are also used to improve the processing speed. Finally, the atmospheric light scattering model is used to restore the image. A plenty of experiments show that algorithm is effective, efficient and has a wide range of application.

Evaluating the scattered radiation intensity in CBCT

NASA Astrophysics Data System (ADS)

Gonçalves, O. D.; Boldt, S.; Nadaes, M.; Devito, K. L.

2018-03-01

In this work we calculate the ratio between scattered and transmitted photons (STRR) by a water cylinder reaching a detector matrix element (DME) in a flat array of detectors, similar to the used in cone beam tomography (CBCT), as a function of the field of view (FOV) and the irradiated volume of the scanned object. We perform the calculation by obtaining an equation to determine the scattered and transmitted radiation and building a computer code in order to calculate the contribution of all voxels of the sample. We compare calculated results with the shades of gray in a central slice of a tomography obtained from a cylindrical glass container filled with distilled water. The tomography was performed with an I-CAT tomograph (Imaging Science International), from the Department of Dental Clinic - Oral Radiology, Universidade Federal de Juiz de Fora. The shade of gray (voxel gray value - VGV) was obtained using the software provided with the I-CAT. The experimental results show a general behavior compatible with theoretical previsions attesting the validity of the method used to calculate the scattering contributions from simple scattering theories in cone beam tomography. The results also attest to the impossibility of obtaining Hounsfield values from a CBCT.

Effect of field-of-view size on gray values derived from cone-beam computed tomography compared with the Hounsfield unit values from multidetector computed tomography scans

PubMed Central

Shokri, Abbas; Bidgoli, Mohsen; Akbarzadeh, Mahdi; Ghazikhanlu-Sani, Karim; Fallahi-Sichani, Hamed

2018-01-01

Purpose This study aimed to evaluate the effect of field-of-view (FOV) size on the gray values derived from conebeam computed tomography (CBCT) compared with the Hounsfield unit values from multidetector computed tomography (MDCT) scans as the gold standard. Materials and Methods A radiographic phantom was designed with 4 acrylic cylinders. One cylinder was filled with distilled water, and the other 3 were filled with 3 types of bone substitute: namely, Nanobone, Cenobone, and Cerabone. The phantom was scanned with 2 CBCT systems using 2 different FOV sizes, and 1 MDCT system was used as the gold standard. The mean gray values (MGVs) of each cylinder were calculated in each imaging protocol. Results In both CBCT systems, significant differences were noted in the MGVs of all materials between the 2 FOV sizes (P<.05) except for Cerabone in the Cranex3D system. Significant differences were found in the MGVs of each material compared with the others in both FOV sizes for each CBCT system. No significant difference was seen between the Cranex3D CBCT system and the MDCT system in the MGVs of bone substitutes on images obtained with a small FOV. Conclusion The size of the FOV significantly changed the MGVs of all bone substitutes, except for Cerabone in the Cranex3D system. Both CBCT systems had the ability to distinguish the 3 types of bone substitutes based on a comparison of their MGVs. The Cranex3D CBCT system used with a small FOV had a significant correlation with MDCT results. PMID:29581947

An improved quantum watermarking scheme using small-scale quantum circuits and color scrambling

NASA Astrophysics Data System (ADS)

Li, Panchi; Zhao, Ya; Xiao, Hong; Cao, Maojun

2017-05-01

In order to solve the problem of embedding the watermark into the quantum color image, in this paper, an improved scheme of using small-scale quantum circuits and color scrambling is proposed. Both color carrier image and color watermark image are represented using novel enhanced quantum representation. The image sizes for carrier and watermark are assumed to be 2^{n+1}× 2^{n+2} and 2n× 2n, respectively. At first, the color of pixels in watermark image is scrambled using the controlled rotation gates, and then, the scrambled watermark with 2^n× 2^n image size and 24-qubit gray scale is expanded to an image with 2^{n+1}× 2^{n+2} image size and 3-qubit gray scale. Finally, the expanded watermark image is embedded into the carrier image by the controlled-NOT gates. The extraction of watermark is the reverse process of embedding it into carrier image, which is achieved by applying operations in the reverse order. Simulation-based experimental results show that the proposed scheme is superior to other similar algorithms in terms of three items, visual quality, scrambling effect of watermark image, and noise resistibility.

RATIO_TOOL - SOFTWARE FOR COMPUTING IMAGE RATIOS

NASA Technical Reports Server (NTRS)

Yates, G. L.

1994-01-01

Geological studies analyze spectral data in order to gain information on surface materials. RATIO_TOOL is an interactive program for viewing and analyzing large multispectral image data sets that have been created by an imaging spectrometer. While the standard approach to classification of multispectral data is to match the spectrum for each input pixel against a library of known mineral spectra, RATIO_TOOL uses ratios of spectral bands in order to spot significant areas of interest within a multispectral image. Each image band can be viewed iteratively, or a selected image band of the data set can be requested and displayed. When the image ratios are computed, the result is displayed as a gray scale image. At this point a histogram option helps in viewing the distribution of values. A thresholding option can then be used to segment the ratio image result into two to four classes. The segmented image is then color coded to indicate threshold classes and displayed alongside the gray scale image. RATIO_TOOL is written in C language for Sun series computers running SunOS 4.0 and later. It requires the XView toolkit and the OpenWindows window manager (version 2.0 or 3.0). The XView toolkit is distributed with Open Windows. A color monitor is also required. The standard distribution medium for RATIO_TOOL is a .25 inch streaming magnetic tape cartridge in UNIX tar format. An electronic copy of the documentation is included on the program media. RATIO_TOOL was developed in 1992 and is a copyrighted work with all copyright vested in NASA. Sun, SunOS, and OpenWindows are trademarks of Sun Microsystems, Inc. UNIX is a registered trademark of AT&T Bell Laboratories.

Fuzzy control system for a remote focusing microscope

NASA Astrophysics Data System (ADS)

Weiss, Jonathan J.; Tran, Luc P.

1992-01-01

Space Station Crew Health Care System procedures require the use of an on-board microscope whose slide images will be transmitted for analysis by ground-based microbiologists. Focusing of microscope slides is low on the list of crew priorities, so NASA is investigating the option of telerobotic focusing controlled by the microbiologist on the ground, using continuous video feedback. However, even at Space Station distances, the transmission time lag may disrupt the focusing process, severely limiting the number of slides that can be analyzed within a given bandwidth allocation. Substantial time could be saved if on-board automation could pre-focus each slide before transmission. The authors demonstrate the feasibility of on-board automatic focusing using a fuzzy logic ruled-based system to bring the slide image into focus. The original prototype system was produced in under two months and at low cost. Slide images are captured by a video camera, then digitized by gray-scale value. A software function calculates an index of 'sharpness' based on gray-scale contrasts. The fuzzy logic rule-based system uses feedback to set the microscope's focusing control in an attempt to maximize sharpness. The systems as currently implemented performs satisfactorily in focusing a variety of slide types at magnification levels ranging from 10 to 1000x. Although feasibility has been demonstrated, the system's performance and usability could be improved substantially in four ways: by upgrading the quality and resolution of the video imaging system (including the use of full color); by empirically defining and calibrating the index of image sharpness; by letting the overall focusing strategy vary depending on user-specified parameters; and by fine-tuning the fuzzy rules, set definitions, and procedures used.

Voxel-Based Morphometry and fMRI Revealed Differences in Brain Gray Matter in Breastfed and Milk Formula-Fed Children.

PubMed

Ou, X; Andres, A; Pivik, R T; Cleves, M A; Snow, J H; Ding, Z; Badger, T M

2016-04-01

Infant diets may have significant impact on brain development in children. The aim of this study was to evaluate brain gray matter structure and function in 8-year-old children who were predominantly breastfed or fed cow's milk formula as infants. Forty-two healthy children (breastfed: n = 22, 10 boys and 12 girls; cow's milk formula: n = 20, 10 boys and 10 girls) were studied by using structural MR imaging (3D T1-weighted imaging) and blood oxygen level-dependent fMRI (while performing tasks involving visual perception and language functions). They were also administered standardized tests evaluating intelligence (Reynolds Intellectual Assessment Scales) and language skills (Clinical Evaluation of Language Fundamentals). Total brain gray matter volume did not differ between the breastfed and cow's milk formula groups. However, breastfed children had significantly higher (P < .05, corrected) regional gray matter volume measured by voxel-based morphometry in the left inferior temporal lobe and left superior parietal lobe compared with cow's milk formula-fed children. Breastfed children showed significantly more brain activation in the right frontal and left/right temporal lobes on fMRI when processing the perception task and in the left temporal/occipital lobe when processing the visual language task than cow's milk formula-fed children. The imaging findings were associated with significantly better performance for breastfed than cow's milk formula-fed children on both tasks. Our findings indicated greater regional gray matter development and better regional gray matter function in breastfed than cow's milk formula-fed children at 8 years of age and suggested that infant diets may have long-term influences on brain development in children. © 2016 by American Journal of Neuroradiology.

Maps of averaged spectral deviations from soil lines and their comparison with traditional soil maps

NASA Astrophysics Data System (ADS)

Rukhovich, D. I.; Rukhovich, A. D.; Rukhovich, D. D.; Simakova, M. S.; Kulyanitsa, A. L.; Bryzzhev, A. V.; Koroleva, P. V.

2016-07-01

The analysis of 34 cloudless fragments of Landsat 5, 7, and 8 images (1985-2014) on the territory of Plavsk, Arsen'evsk, and Chern districts of Tula oblast has been performed. It is shown that bare soil surface on the RED-NIR plots derived from the images cannot be described in the form of a sector of spectral plane as it can be done for the NDVI values. The notion of spectral neighborhood of soil line (SNSL) is suggested. It is defined as the sum of points of the RED-NIR spectral space, which are characterized by spectral characteristics of the bare soil applied for constructing soil lines. The way of the SNSL separation along the line of the lowest concentration density of points on the RED-NIR spectral space is suggested. This line separates bare soil surface from vegetating plants. The SNSL has been applied to construct soil line (SL) for each of the 34 images and to delineate bare soil surface on them. Distances from the points with averaged RED-NIR coordinates to the SL have been calculated using the method of moving window. These distances can be referred to as averaged spectral deviations (ASDs). The calculations have been performed strictly for the SNSL areas. As a result, 34 maps of ASDs have been created. These maps contain ASD values for 6036 points of a grid used in the study. Then, the integral map of normalized ASD values has been built with due account for the number of points participating in the calculation (i.e., lying in the SNSL) within the moving window. The integral map of ASD values has been compared with four traditional soil maps on the studied territory. It is shown that this integral map can be interpreted in terms of soil taxa: the areas of seven soil subtypes (soddy moderately podzolic, soddy slightly podzolic, light gray forest. gray forest, dark gray forest, podzolized chernozems, and leached chernozems) belonging to three soil types (soddy-podzolic, gray forest, and chernozemic soils) can be delineated on it.

Ink-jet printout of radiographs on transparent film and glossy paper versus monitor display: an ROC analysis.

PubMed

Kühl, Sebastian; Krummenauer, Frank; Dagassan-Berndt, Dorothea; Lambrecht, Thomas J; d'Hoedt, Bernd; Schulze, Ralf Kurt Willy

2011-06-01

The aim of this study was to compare the depiction ability of small grayscale contrasts in ink-jet printouts of digital radiographs on different print media with CRT monitor. A CCD-based digital cephalometric image of a stepless aluminum wedge containing 50 bur holes of different depth was cut into 100 isometric images. Each image was printed on glossy paper and on transparent film by means of a high-resolution desktop inkjet printer at specific settings. The printed images were viewed under standardized conditions, and the perceptibility of the bur holes was evaluated and compared to the perceptibility on a 17-in CRT monitor. Thirty observers stated their blinded decision on a five-point confidence scale. Areas (Az) under receiver operating characteristics curves were calculated and compared using the pair wise sign tests. Overall agreement was estimated using Cohen's kappa device and observer bias using McNemar's test. Glossy paper prints and monitor display revealed significantly higher (P < 0.001) average Az values (0.83) compared to prints on transparent film (0.79), which was caused by higher sensitivity. Specificity was similar for all modalities. The sensitivity was dependent on the mean gray scale values for the transparent film.

Laboratory Characterization of Gray Masonry Concrete

DTIC Science & Technology

2007-08-01

Based on the appropriate values of posttest water content, wet density, and an assumed grain density of 2.61 Mg/m3, values of dry density, porosity...velocity measurements were performed on each specimen. The TXC tests exhibited a continuous increase in maximum principal stress difference with...14 Figure 3. Spring-arm lateral deformeter mounted on test

The use of a standardized gray reference card in dental photography to correct the effects of five commonly used diffusers on the color of 40 extracted human teeth.

PubMed

Hein, Sascha; Zangl, Michael

2016-01-01

The aim of this in vitro study was to investigate the color changes of human teeth caused by five different diffuser materials commonly used in dental photography, as well as software influence, and to confirm whether the use of a standardized gray reference card is effective in correcting these color changes during digital postproduction. Forty extracted human teeth were obtained from a specialized oral surgery practice in Cham, Germany. Five commonly used diffuser materials were chosen to be investigated, which included: polyethylene (PET), White Frost photographic paper, LumiQuest polyamide (nylon) material, 80 gsm white printing paper, and 3M linear polarizing filter sheet used for cross polarization. A digital single-lens reflex camera (Canon EOS 5D MKII) was used, together with a twin flash suitable for macrophotography (Canon MT-24EX Macro Twin Lite). Images were tethered into Adobe Lightroom CC using the RAW format. A standardized gray reference card (WhiBal, Michael Tapes Design) was used for exposure calibration and white balancing. Classic Color Me- ter software (Ricci Adams, version 1.6 (122)) was used to obtain CIE L*a*b* values of the specimens before and after white balancing and exposure correction. All diffusers caused visually perceivable color changes on the extracted teeth: White Frost (ΔE* 1.24; sd 0.47), 80 gsm printing paper (ΔE* 2.94; sd 0.35), LumiQuest polyamide (ΔE* 3.68; sd 0.54), PET (ΔE* 6.55; sd 0.41), and 3M linear polarizing filter sheet (ΔE* 7.58; sd 1.00). The use of a standardized gray reference card (WhiBal) could correct these values below the visually perceivable threshold: White Frost (ΔE* 0.58; sd 0.36), 80 gsm printing paper (ΔE* 0.93; sd 0.54), LumiQuest polyamide (ΔE* 0.66; sd 0.58), PET (ΔE* 0.59; sd 0.33), and 3M linear polarizing filter sheet (ΔE* 0.53; sd 0.42). The use of a standardized gray reference card with specified CIE L*a*b* values should be considered when diffusers are used in dental photography in order to reveal the color of preoperative situations (ie, shade documentation) and document postoperative results accurately.

Induction of resistance to gray mold with benzothiadiazole modifies amino acid profile and increases proanthocyanidins in grape: primary versus secondary metabolism.

PubMed

Iriti, Marcello; Rossoni, Mara; Borgo, Michele; Ferrara, Luigia; Faoro, Franco

2005-11-16

Field treatments of grapevine (cv. Merlot) with the plant activator benzothiadiazole (BTH, 0.3 mM) induced resistance against gray mold caused by Botrytis cinerea. Both incidence and severity of the disease were reduced. The resistance was associated with an increase of total polyphenols in berry skins, in particular, the proanthocyanidin fraction, that increased up to 36%. The amino acid profile of leaves was also modified by treatments, particularly lysine, that augmented 4-fold. Other amino acids involved in resistance mechanisms to either biotic or abiotic stress increased as well. These results indicate that BTH treatments can be used to control gray mold, thereby limiting an excessive use of fungicides, and could be exploited to increase the content of micronutrients of high nutritional value, arising from both primary and secondary metabolisms.

Prostate segmentation in MR images using discriminant boundary features.

PubMed

Yang, Meijuan; Li, Xuelong; Turkbey, Baris; Choyke, Peter L; Yan, Pingkun

2013-02-01

Segmentation of the prostate in magnetic resonance image has become more in need for its assistance to diagnosis and surgical planning of prostate carcinoma. Due to the natural variability of anatomical structures, statistical shape model has been widely applied in medical image segmentation. Robust and distinctive local features are critical for statistical shape model to achieve accurate segmentation results. The scale invariant feature transformation (SIFT) has been employed to capture the information of the local patch surrounding the boundary. However, when SIFT feature being used for segmentation, the scale and variance are not specified with the location of the point of interest. To deal with it, the discriminant analysis in machine learning is introduced to measure the distinctiveness of the learned SIFT features for each landmark directly and to make the scale and variance adaptive to the locations. As the gray values and gradients vary significantly over the boundary of the prostate, separate appearance descriptors are built for each landmark and then optimized. After that, a two stage coarse-to-fine segmentation approach is carried out by incorporating the local shape variations. Finally, the experiments on prostate segmentation from MR image are conducted to verify the efficiency of the proposed algorithms.

Rotation And Scale Invariant Object Recognition Using A Distributed Associative Memory

NASA Astrophysics Data System (ADS)

Wechsler, Harry; Zimmerman, George Lee

1988-04-01

This paper describes an approach to 2-dimensional object recognition. Complex-log conformal mapping is combined with a distributed associative memory to create a system which recognizes objects regardless of changes in rotation or scale. Recalled information from the memorized database is used to classify an object, reconstruct the memorized version of the object, and estimate the magnitude of changes in scale or rotation. The system response is resistant to moderate amounts of noise and occlusion. Several experiments, using real, gray scale images, are presented to show the feasibility of our approach.

Trojan Asteroid Shares Orbit with Earth Artist Animation

NASA Image and Video Library

2011-07-27

This artist concept illustrates the first known Earth Trojan asteroid, discovered by NEOWISE, the asteroid-hunting portion of NASA WISE mission. The asteroid is shown in gray and its extreme orbit is shown in green. Objects are not drawn to scale.

In vivo skin imaging for hydration and micro relief-measurement.

PubMed

Kardosova, Z; Hegyi, V

2013-01-01

We present the results of our work with device used for measurement of skin capacitance before and after application of moisturizing creams and results of experiment performed on cellulose filter papers soaked with different solvents. The measurements were performed by a device built on capacitance sensor, which provides an investigator with a capacitance image of the skin. The capacitance values are coded in a range of 256 gray levels then the skin hydration can be characterized using parameters derived from gray level histogram by specific software. The images obtained by device allow a highly precise observation of skin topography. Measuring of skin capacitance brings new, objective, reliable information about topographical, physical and chemical parameters of the skin. The study shows that there is a good correlation between the average grayscale values and skin hydration. In future works we need to complete more comparison studies, interpret the average grayscale values to skin hydration levels and use it for follow-up of dynamics of skin micro-relief and hydration changes (Fig. 6, Ref. 15).

[TSH anti-receptor antibodies in Graves' disease].

PubMed

Sérgio, M R; Godinho, C; Guerra, L; Agapito, A; Fonseca, F; Costa, C

1996-01-01

The purpose of this study was to evaluate the sensitivity, specificity and predictive value of thyrotropin receptor antibody (TRAb) in the diagnosis of Graves disease. TRAb was tested by an isotopic receptor assay-TRAK Henning-in 80 newly diagnosed, untreated Graves disease patients (group I), 63 with other thyroid diseases (group II) and 60 controls (group III). In group I, 11 patients were TRAb negative and 7 were considered in the gray area (TRAb between 9 and 14 U/L). In group II, only 2 patients had TRAb 9 U/l and all controls were TRAb negative. For statistical analysis patients with TRAb in gray area were excluded. Sensitivity and specificity for this assay were 84.5 and 100% respectively. Predictive value of 100% affords certainty that a hyperthyroid patient with a positive TRAb has Graves disease, not sequining a scintigram.

Patient dose, gray level and exposure index with a computed radiography system

NASA Astrophysics Data System (ADS)

Silva, T. R.; Yoshimura, E. M.

2014-02-01

Computed radiography (CR) is gradually replacing conventional screen-film system in Brazil. To assess image quality, manufactures provide the calculation of an exposure index through the acquisition software of the CR system. The objective of this study is to verify if the CR image can be used as an evaluator of patient absorbed dose too, through a relationship between the entrance skin dose and the exposure index or the gray level values obtained in the image. The CR system used for this study (Agfa model 30-X with NX acquisition software) calculates an exposure index called Log of the Median (lgM), related to the absorbed dose to the IP. The lgM value depends on the average gray level (called Scan Average Level (SAL)) of the segmented pixel value histogram of the whole image. A Rando male phantom was used to simulate a human body (chest and head), and was irradiated with an X-ray equipment, using usual radiologic techniques for chest exams. Thermoluminescent dosimeters (LiF, TLD100) were used to evaluate entrance skin dose and exit dose. The results showed a logarithm relation between entrance dose and SAL in the image center, regardless of the beam filtration. The exposure index varies linearly with the entrance dose, but the angular coefficient is beam quality dependent. We conclude that, with an adequate calibration, the CR system can be used to evaluate the patient absorbed dose.

Optimization and evaluation of metal injection molding by using X-ray tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Shidi; Zhang, Ruijie; Qu, Xuanhui, E-mail: quxh@ustb.edu.cn

2015-06-15

6061 aluminum alloy and 316L stainless steel green bodies were obtained by using different injection parameters (injection pressure, speed and temperature). After injection process, the green bodies were scanned by X-ray tomography. The projection and reconstruction images show the different kinds of defects obtained by the improper injection parameters. Then, 3D rendering of the Al alloy green bodies was used to demonstrate the spatial morphology characteristics of the serious defects. Based on the scanned and calculated results, it is convenient to obtain the proper injection parameters for the Al alloy. Then, reasons of the defect formation were discussed. During moldmore » filling, the serious defects mainly formed in the case of low injection temperature and high injection speed. According to the gray value distribution of projection image, a threshold gray value was obtained to evaluate whether the quality of green body can meet the desired standard. The proper injection parameters of 316L stainless steel can be obtained efficiently by using the method of analyzing the Al alloy injection. - Highlights: • Different types of defects in green bodies were scanned by using X-ray tomography. • Reasons of the defect formation were discussed. • Optimization of the injection parameters can be simplified greatly by the way of X-ray tomography. • Evaluation standard of the injection process can be obtained by using the gray value distribution of projection image.« less

Real-time detection of respiration rate with non-contact mode based on low-end imaging equipment

NASA Astrophysics Data System (ADS)

Jin, Xiaoli; Dong, Liquan; Zhao, Yuejin; Liu, Xiaohua; Liu, Ming; Yang, Lei; Liu, Weiyu; Zhao, Jingsheng; Xing, Jinhui

2013-09-01

Standard instrumentation for the assessment of respiration rate is large and based on invasive method, and not suitable for daily inspection. An optical, simple and non-contact measurement method to detect human respiration rate using lowend imaging equipment is discussed. This technology is based on the visible light absorption of blood, which contains many important physiological information of the cardiovascular system. The light absorption of facial area can be indirectly reflected to gray value of the corresponding area image. In this paper, we acquire the respiration rate through the video signal captured by low-end imaging equipment. Firstly, the color CCD captures the facial area below the eyes and every frame of the video can be separated into three RGB channels. The blue channel is extracted as the research object. Then, we calculate the mean gray value for each image and draw the mean gray curve along the time. Fourier transform can get the frequency spectrogram of the graph, which is filtered through the Fourier filter. The extreme point is the value of the respiratory rate. Finally, an available interface program is designed and we have some volunteers tested. The correlation coefficient between the experimental data and the data provided by a reference instrument is 0.98. The consistency of the experimental results is very well. This technology costs so low that it will be widely used in medical and daily respiration rate measurement.

An extensive analysis of various texture feature extractors to detect Diabetes Mellitus using facial specific regions.

PubMed

Shu, Ting; Zhang, Bob; Yan Tang, Yuan

2017-04-01

Researchers have recently discovered that Diabetes Mellitus can be detected through non-invasive computerized method. However, the focus has been on facial block color features. In this paper, we extensively study the effects of texture features extracted from facial specific regions at detecting Diabetes Mellitus using eight texture extractors. The eight methods are from four texture feature families: (1) statistical texture feature family: Image Gray-scale Histogram, Gray-level Co-occurance Matrix, and Local Binary Pattern, (2) structural texture feature family: Voronoi Tessellation, (3) signal processing based texture feature family: Gaussian, Steerable, and Gabor filters, and (4) model based texture feature family: Markov Random Field. In order to determine the most appropriate extractor with optimal parameter(s), various parameter(s) of each extractor are experimented. For each extractor, the same dataset (284 Diabetes Mellitus and 231 Healthy samples), classifiers (k-Nearest Neighbors and Support Vector Machines), and validation method (10-fold cross validation) are used. According to the experiments, the first and third families achieved a better outcome at detecting Diabetes Mellitus than the other two. The best texture feature extractor for Diabetes Mellitus detection is the Image Gray-scale Histogram with bin number=256, obtaining an accuracy of 99.02%, a sensitivity of 99.64%, and a specificity of 98.26% by using SVM. Copyright © 2017 Elsevier Ltd. All rights reserved.

Normal gray and white matter volume after weight restoration in adolescents with anorexia nervosa.

PubMed

Lázaro, Luisa; Andrés, Susana; Calvo, Anna; Cullell, Clàudia; Moreno, Elena; Plana, M Teresa; Falcón, Carles; Bargalló, Núria; Castro-Fornieles, Josefina

2013-12-01

The aim of this study was to determine whether treated, weight-stabilized adolescents with anorexia nervosa (AN) present brain volume differences in comparison with healthy controls. Thirty-five adolescents with weight-recovered AN and 17 healthy controls were assessed by means of psychopathology scales and magnetic resonance imaging. Axial three-dimensional T1-weighted images were obtained in a 1.5 Tesla scanner and analyzed using optimized voxel-based morphometry (VBM). There were no significant differences between controls and weight-stabilized AN patients with regard to global volumes of either gray or white brain matter, or in the regional VBM study. Differences were not significant between patients with psychopharmacological treatment and without, between those with amenorrhea and without, as well as between patients with restrictive versus purgative AN. The present findings reveal no global or regional gray or white matter abnormalities in this sample of adolescents following weight restoration. Copyright © 2013 Wiley Periodicals, Inc.

Hemisphere, gender and age-related effects on iron deposition in deep gray matter revealed by quantitative susceptibility mapping.

PubMed

Gong, Nan-Jie; Wong, Chun-Sing; Hui, Edward S; Chan, Chun-Chung; Leung, Lam-Ming

2015-10-01

The purpose of this work was to investigate the effects of hemispheric location, gender and age on susceptibility value, as well as the association between susceptibility value and diffusional metrics, in deep gray matter. Iron content was estimated in vivo using quantitative susceptibility mapping. Microstructure was probed using diffusional kurtosis imaging. Regional susceptibility and diffusional metrics were measured for the putamen, caudate nucleus, globus pallidus, thalamus, substantia nigra and red nucleus in 42 healthy adults (age range 25-78 years). Susceptibility value was significantly higher in the left than the right side of the caudate nucleus (P = 0.043) and substantia nigra (P < 0.001). Women exhibited lower susceptibility values than men in the thalamus (P < 0.001) and red nucleus (P = 0.032). Significant age-related increases of susceptibility were observed in the putamen (P < 0.001), red nucleus (P < 0.001), substantia nigra (P = 0.004), caudate nucleus (P < 0.001) and globus pallidus (P = 0.017). The putamen exhibited the highest rate of iron accumulation with aging (slope of linear regression = 0.73 × 10(-3) ppm/year), which was nearly twice those in substantia nigra (slope = 0.40 × 10(-3) ppm/year) and caudate nucleus (slope = 0.39 × 10(-3) ppm/year). Significant positive correlations between the susceptibility value and diffusion measurements were observed for fractional anisotropy (P = 0.045) and mean kurtosis (P = 0.048) in the putamen without controlling for age. Neither correlation was significant after controlling for age. Hemisphere, gender and age-related differences in iron measurements were observed in deep gray matter. Notably, the putamen exhibited the highest rate of increase in susceptibility with aging. Correlations between susceptibility value and microstructural measurements were inconclusive. These findings could provide new clues for unveiling mechanisms underlying iron-related neurodegenerative diseases. Copyright © 2015 John Wiley & Sons, Ltd.

Image Edge Extraction via Fuzzy Reasoning

NASA Technical Reports Server (NTRS)

Dominquez, Jesus A. (Inventor); Klinko, Steve (Inventor)

2008-01-01

A computer-based technique for detecting edges in gray level digital images employs fuzzy reasoning to analyze whether each pixel in an image is likely on an edge. The image is analyzed on a pixel-by-pixel basis by analyzing gradient levels of pixels in a square window surrounding the pixel being analyzed. An edge path passing through the pixel having the greatest intensity gradient is used as input to a fuzzy membership function, which employs fuzzy singletons and inference rules to assigns a new gray level value to the pixel that is related to the pixel's edginess degree.

Genetic variability and heritability on Kipas Putih soybean mutant lines using gamma rays irradiation (M3 generation)

NASA Astrophysics Data System (ADS)

Nilahayati; Rosmayati; Hanafiah, D. S.; Harahap, F.

2018-02-01

The objective of the research was to determine the selection criteria in Kipas Putih Soybean with gamma rays irradiation in M3 generation. In this study there are four populations namely population 0 Gray (control), 100 Gray, 200 Gray and 300 Gray. The results showed that high genotypic coefficient of variation (GCV) was obtained on the number of pods and seed weight per plant in population 200 Gy, number of branches on 100 Gy and 300 Gy, number of pods and seed weight per plants 100 and 200 Gy, moderate GCV in number of branches on 100 and 300 Gy while other characters such as plant height, numbers of branches on 200 Gy, flowering and harvest age have narrow GCV criteria. High heritability values are found in 300 Gy on plant height, number of branches 300 Gy, number of pods and seed weight per plant 200 Gy, days to flower 200 Gy and 300 Gy and days to harvest of all doses. Based on the genetic variabiliy and heritability, characters that can be used as selection criteria in this study is number of pods and seeds weight per plant, days to flower and days to harvest.

An Integrated Environmental Assessment of Green and Gray Infrastructure Strategies for Robust Decision Making.

PubMed

Casal-Campos, Arturo; Fu, Guangtao; Butler, David; Moore, Andrew

2015-07-21

The robustness of a range of watershed-scale "green" and "gray" drainage strategies in the future is explored through comprehensive modeling of a fully integrated urban wastewater system case. Four socio-economic future scenarios, defined by parameters affecting the environmental performance of the system, are proposed to account for the uncertain variability of conditions in the year 2050. A regret-based approach is applied to assess the relative performance of strategies in multiple impact categories (environmental, economic, and social) as well as to evaluate their robustness across future scenarios. The concept of regret proves useful in identifying performance trade-offs and recognizing states of the world most critical to decisions. The study highlights the robustness of green strategies (particularly rain gardens, resulting in half the regret of most options) over end-of-pipe gray alternatives (surface water separation or sewer and storage rehabilitation), which may be costly (on average, 25% of the total regret of these options) and tend to focus on sewer flooding and CSO alleviation while compromising on downstream system performance (this accounts for around 50% of their total regret). Trade-offs and scenario regrets observed in the analysis suggest that the combination of green and gray strategies may still offer further potential for robustness.

Evaluating Green/Gray Infrastructure for CSO/Stormwater Control

EPA Science Inventory

The NRMRL is conducting this project to evaluate the water quality and quantity benefits of a large-scale application of green infrastructure (low-impact development/best management practices) retrofits in an entire subcatchment. It will document ORD's effort to demonstrate the e...

Ecological risk assessment of aerial insectivores of the Clinch River/Poplar Creek system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baron, L.A.; Sample, B.E.

Risks to aerial insectivores (species that consume flying insects; rough-winged swallows, little brown bats, and endangered gray bats) were assessed for the CERCLA remedial investigation of the Clinch River/Poplar Creek system. Adult mayflies and sediment were collected from four locations and analyzed for contaminants. Sediment-to-mayfly contaminant transfer factors were generated from these data and used to estimate contaminant concentrations in mayflies from thirteen additional locations. Contaminants of potential concern (COPCs) were identified by comparing exposure estimates, generated using point estimates of parameter values, to NOAELS. COPCs included mercury, arsenic, and PCBs. Exposure to COPCs was re-estimated using Monte Carlo simulations.more » Adverse population effects were assumed likely if > 20% of the estimated exposure distribution was greater than the LOAEL. Exposure of swallows to mercury was a significant risk at two locations. Exposure of bats to mercury was a significant risk at only one location. While consideration of movement and foraging territory did not reduce estimated risks to swallows, when exposures for gray and little brown bats were re-estimated, population-level risks from mercury were no longer considered likely. As an endangered species however, protection is extended to individual gray bats. While less than 20% of the mercury exposure distribution for gray bats was > LOAEL, > 99% of the distribution was >NOAEL. Therefore, adverse effects may occur among maximally exposed individual gray bats. Available data indicate that contaminants in Poplar Creek are likely to present a risk to the swallow population, do not present a risk to the little brown bat population, and may present a risk to individual gray bats.« less

Disrupted subject-specific gray matter network properties and cognitive dysfunction in type 1 diabetes patients with and without proliferative retinopathy.

PubMed

van Duinkerken, Eelco; Ijzerman, Richard G; Klein, Martin; Moll, Annette C; Snoek, Frank J; Scheltens, Philip; Pouwels, Petra J W; Barkhof, Frederik; Diamant, Michaela; Tijms, Betty M

2016-03-01

Type 1 diabetes mellitus (T1DM) patients, especially with concomitant microvascular disease, such as proliferative retinopathy, have an increased risk of cognitive deficits. Local cortical gray matter volume reductions only partially explain these cognitive dysfunctions, possibly because volume reductions do not take into account the complex connectivity structure of the brain. This study aimed to identify gray matter network alterations in relation to cognition in T1DM. We investigated if subject-specific structural gray matter network properties, constructed from T1-weighted MRI scans, were different between T1DM patients with (n = 51) and without (n = 53) proliferative retinopathy versus controls (n = 49), and were associated to cognitive decrements and fractional anisotropy, as measured by voxel-based TBSS. Global normalized and local (45 bilateral anatomical regions) clustering coefficient and path length were assessed. These network properties measure how the organization of connections in a network differs from that of randomly connected networks. Global gray matter network topology was more randomly organized in both T1DM patient groups versus controls, with the largest effects seen in patients with proliferative retinopathy. Lower local path length values were widely distributed throughout the brain. Lower local clustering was observed in the middle frontal, postcentral, and occipital areas. Complex network topology explained up to 20% of the variance of cognitive decrements, beyond other predictors. Exploratory analyses showed that lower fractional anisotropy was associated with a more random gray matter network organization. T1DM and proliferative retinopathy affect cortical network organization that may consequently contribute to clinically relevant changes in cognitive functioning in these patients. © 2015 Wiley Periodicals, Inc.

Reference tissue normalization in longitudinal (18)F-florbetapir positron emission tomography of late mild cognitive impairment.

PubMed

Shokouhi, Sepideh; Mckay, John W; Baker, Suzanne L; Kang, Hakmook; Brill, Aaron B; Gwirtsman, Harry E; Riddle, William R; Claassen, Daniel O; Rogers, Baxter P

2016-01-15

Semiquantitative methods such as the standardized uptake value ratio (SUVR) require normalization of the radiotracer activity to a reference tissue to monitor changes in the accumulation of amyloid-β (Aβ) plaques measured with positron emission tomography (PET). The objective of this study was to evaluate the effect of reference tissue normalization in a test-retest (18)F-florbetapir SUVR study using cerebellar gray matter, white matter (two different segmentation masks), brainstem, and corpus callosum as reference regions. We calculated the correlation between (18)F-florbetapir PET and concurrent cerebrospinal fluid (CSF) Aβ1-42 levels in a late mild cognitive impairment cohort with longitudinal PET and CSF data over the course of 2 years. In addition to conventional SUVR analysis using mean and median values of normalized brain radiotracer activity, we investigated a new image analysis technique-the weighted two-point correlation function (wS2)-to capture potentially more subtle changes in Aβ-PET data. Compared with the SUVRs normalized to cerebellar gray matter, all cerebral-to-white matter normalization schemes resulted in a higher inverse correlation between PET and CSF Aβ1-42, while the brainstem normalization gave the best results (high and most stable correlation). Compared with the SUVR mean and median values, the wS2 values were associated with the lowest coefficient of variation and highest inverse correlation to CSF Aβ1-42 levels across all time points and reference regions, including the cerebellar gray matter. The selection of reference tissue for normalization and the choice of image analysis method can affect changes in cortical (18)F-florbetapir uptake in longitudinal studies.

Quantification of regional cerebral blood flow and volume with dynamic susceptibility contrast-enhanced MR imaging.

PubMed

Rempp, K A; Brix, G; Wenz, F; Becker, C R; Gückel, F; Lorenz, W J

1994-12-01

Quantification of regional cerebral blood flow (rCBF) and volume (rCBV) with dynamic magnetic resonance (MR) imaging. After bolus administration of a paramagnetic contrast medium, rapid T2*-weighted gradient-echo images of two sections were acquired for the simultaneous creation of concentration-time curves in the brain-feeding arteries and in brain tissue. Absolute rCBF and rCBV values were determined for gray and white brain matter in 12 subjects with use of principles of the indicator dilution theory. The mean rCBF value in gray matter was 69.7 mL/min +/- 29.7 per 100 g tissue and in white matter, 33.6 mL/min +/- 11.5 per 100 g tissue; the average rCBV was 8.0 mL +/- 3.1 per 100 g tissue and 4.2 mL +/- 1.0 per 100 g tissue, respectively. An age-related decrease in rCBF and rCBV for gray and white matter was observed. Preliminary data demonstrate that the proposed technique allows the quantification of rCBF and rCBV. Although the results are in good agreement with data from positron emission tomography studies, further evaluation is needed to establish the validity of method.

Texture Feature Analysis for Different Resolution Level of Kidney Ultrasound Images

NASA Astrophysics Data System (ADS)

Kairuddin, Wan Nur Hafsha Wan; Mahmud, Wan Mahani Hafizah Wan

2017-08-01

Image feature extraction is a technique to identify the characteristic of the image. The objective of this work is to discover the texture features that best describe a tissue characteristic of a healthy kidney from ultrasound (US) image. Three ultrasound machines that have different specifications are used in order to get a different quality (different resolution) of the image. Initially, the acquired images are pre-processed to de-noise the speckle to ensure the image preserve the pixels in a region of interest (ROI) for further extraction. Gaussian Low- pass Filter is chosen as the filtering method in this work. 150 of enhanced images then are segmented by creating a foreground and background of image where the mask is created to eliminate some unwanted intensity values. Statistical based texture features method is used namely Intensity Histogram (IH), Gray-Level Co-Occurance Matrix (GLCM) and Gray-level run-length matrix (GLRLM).This method is depends on the spatial distribution of intensity values or gray levels in the kidney region. By using One-Way ANOVA in SPSS, the result indicated that three features (Contrast, Difference Variance and Inverse Difference Moment Normalized) from GLCM are not statistically significant; this concludes that these three features describe a healthy kidney characteristics regardless of the ultrasound image quality.

BMPix and PEAK tools: New methods for automated laminae recognition and counting—Application to glacial varves from Antarctic marine sediment

NASA Astrophysics Data System (ADS)

Weber, M. E.; Reichelt, L.; Kuhn, G.; Pfeiffer, M.; Korff, B.; Thurow, J.; Ricken, W.

2010-03-01

We present tools for rapid and quantitative detection of sediment lamination. The BMPix tool extracts color and gray scale curves from images at pixel resolution. The PEAK tool uses the gray scale curve and performs, for the first time, fully automated counting of laminae based on three methods. The maximum count algorithm counts every bright peak of a couplet of two laminae (annual resolution) in a smoothed curve. The zero-crossing algorithm counts every positive and negative halfway passage of the curve through a wide moving average, separating the record into bright and dark intervals (seasonal resolution). The same is true for the frequency truncation method, which uses Fourier transformation to decompose the curve into its frequency components before counting positive and negative passages. The algorithms are available at doi:10.1594/PANGAEA.729700. We applied the new methods successfully to tree rings, to well-dated and already manually counted marine varves from Saanich Inlet, and to marine laminae from the Antarctic continental margin. In combination with AMS14C dating, we found convincing evidence that laminations in Weddell Sea sites represent varves, deposited continuously over several millennia during the last glacial maximum. The new tools offer several advantages over previous methods. The counting procedures are based on a moving average generated from gray scale curves instead of manual counting. Hence, results are highly objective and rely on reproducible mathematical criteria. Also, the PEAK tool measures the thickness of each year or season. Since all information required is displayed graphically, interactive optimization of the counting algorithms can be achieved quickly and conveniently.

Normalization of similarity-based individual brain networks from gray matter MRI and its association with neurodevelopment in infants with intrauterine growth restriction.

PubMed

Batalle, Dafnis; Muñoz-Moreno, Emma; Figueras, Francesc; Bargallo, Nuria; Eixarch, Elisenda; Gratacos, Eduard

2013-12-01

Obtaining individual biomarkers for the prediction of altered neurological outcome is a challenge of modern medicine and neuroscience. Connectomics based on magnetic resonance imaging (MRI) stands as a good candidate to exhaustively extract information from MRI by integrating the information obtained in a few network features that can be used as individual biomarkers of neurological outcome. However, this approach typically requires the use of diffusion and/or functional MRI to extract individual brain networks, which require high acquisition times and present an extreme sensitivity to motion artifacts, critical problems when scanning fetuses and infants. Extraction of individual networks based on morphological similarity from gray matter is a new approach that benefits from the power of graph theory analysis to describe gray matter morphology as a large-scale morphological network from a typical clinical anatomic acquisition such as T1-weighted MRI. In the present paper we propose a methodology to normalize these large-scale morphological networks to a brain network with standardized size based on a parcellation scheme. The proposed methodology was applied to reconstruct individual brain networks of 63 one-year-old infants, 41 infants with intrauterine growth restriction (IUGR) and 22 controls, showing altered network features in the IUGR group, and their association with neurodevelopmental outcome at two years of age by means of ordinal regression analysis of the network features obtained with Bayley Scale for Infant and Toddler Development, third edition. Although it must be more widely assessed, this methodology stands as a good candidate for the development of biomarkers for altered neurodevelopment in the pediatric population. © 2013 Elsevier Inc. All rights reserved.

At-risk and intervention thresholds of occupational stress using a visual analogue scale

PubMed Central

Pereira, Bruno; Moustafa, Farès; Naughton, Geraldine; Lesage, François-Xavier; Lambert, Céline

2017-01-01

Background The visual analogue scale (VAS) is widely used in clinical practice by occupational physicians to assess perceived stress in workers. However, a single cut-off (black-or-white decision) inadequately discriminates between workers with and without stress. We explored an innovative statistical approach to distinguish an at-risk population among stressed workers, and to establish a threshold over which an action is urgently required, via the use of two cut-offs. Methods Participants were recruited during annual work medical examinations by a random sample of workers from five occupational health centres. We previously proposed a single cut-off of VAS stress in comparison with the Perceived Stress Scale (PSS14). Similar methodology was used in the current study, along with a gray zone approach. The lower limit of the gray zone supports sensitivity (“at-risk” threshold; interpreted as requiring closer surveillance) and the upper limit supports specificity (i.e. “intervention” threshold–emergency action required). Results We included 500 workers (49.6% males), aged 40±11 years, with a PSS14 score of 3.8±1.4 and a VAS score of 4.0±2.4. Using a receiver operating characteristic curve and the PSS cut-off score of 7.2, the optimal VAS threshold was 6.8 (sensitivity = 0.89, specificity = 0.87). The lower and upper thresholds of the gray zone were 5 and 8.2, respectively. Conclusions We identified two clinically relevant cut-offs on the VAS of stress: a first cut-off of 5.0 for an at-risk population, and a second cut-off of 8.2 over which an action is urgently required. Future investigations into the relationships between this upper threshold and deleterious events are required. PMID:28586383

Digital shaded relief image of a carbonate platform (northern Great Bahama Bank): Scenery seen and unseen

NASA Astrophysics Data System (ADS)

Boss, Stephen K.

1996-11-01

A mosaic image of the northern Great Bahama Bank was created from separate gray-scale Landsat images using photo-editing and image analysis software that is commercially available for desktop computers. Measurements of pixel gray levels (relative scale from 0 to 255 referred to as digital number, DN) on the mosaic image were compared to bank-top bathymetry (determined from a network of single-channel, high-resolution seismic profiles), bottom type (coarse sand, sandy mud, barren rock, or reef determined from seismic profiles and diver observations), and vegetative cover (presence and/or absence and relative density of the marine angiosperm Thalassia testudinum determined from diver observations). Results of these analyses indicate that bank-top bathymetry is a primary control on observed pixel DN, bottom type is a secondary control on pixel DN, and vegetative cover is a tertiary influence on pixel DN. Consequently, processing of the gray-scale Landsat mosaic with a directional gradient edge-detection filter generated a physiographic shaded relief image resembling bank-top bathymetric patterns related to submerged physiographic features across the platform. The visibility of submerged karst landforms, Pleistocene eolianite ridges, islands, and possible paleo-drainage patterns created during sea-level lowstands is significantly enhanced on processed images relative to the original mosaic. Bank-margin ooid shoals, platform interior sand bodies, reef edifices, and bidirectional sand waves are features resulting from Holocene carbonate deposition that are also more clearly visible on the new physiographic images. Combined with observational data (single-channel, high-resolution seismic profiles, bottom observations by SCUBA divers, sediment and rock cores) across the northern Great Bahama Bank, these physiographic images facilitate comprehension of areal relations among antecedent platform topography, physical processes, and ensuing depositional patterns during sea-level rise.

Texture descriptions of lunar surface derived from LOLA data: Kilometer-scale roughness and entropy maps

NASA Astrophysics Data System (ADS)

Li, Bo; Ling, Zongcheng; Zhang, Jiang; Chen, Jian; Wu, Zhongchen; Ni, Yuheng; Zhao, Haowei

2015-11-01

The lunar global texture maps of roughness and entropy are derived at kilometer scales from Digital Elevation Models (DEMs) data obtained by Lunar Orbiter Laser Altimeter (LOLA) aboard on Lunar Reconnaissance Orbiter (LRO) spacecraft. We use statistical moments of a gray-level histogram of elevations in a neighborhood to compute the roughness and entropy value. Our texture descriptors measurements are shown in global maps at multi-sized square neighborhoods, whose length of side is 3, 5, 10, 20, 40 and 80 pixels, respectively. We found that large-scale topographical changes can only be displayed in maps with longer side of neighborhood, but the small scale global texture maps are more disorderly and unsystematic because of more complicated textures' details. Then, the frequency curves of texture maps are made out, whose shapes and distributions are changing as the spatial scales increases. Entropy frequency curve with minimum 3-pixel scale has large fluctuations and six peaks. According to this entropy curve we can classify lunar surface into maria, highlands, different parts of craters preliminarily. The most obvious textures in the middle-scale roughness and entropy maps are the two typical morphological units, smooth maria and rough highlands. For the impact crater, its roughness and entropy value are characterized by a multiple-ring structure obviously, and its different parts have different texture results. In the last, we made a 2D scatter plot between the two texture results of typical lunar maria and highlands. There are two clusters with largest dot density which are corresponded to the lunar highlands and maria separately. In the lunar mare regions (cluster A), there is a high correlation between roughness and entropy, but in the highlands (Cluster B), the entropy shows little change. This could be subjected to different geological processes of maria and highlands forming different landforms.

Ferroan dolomites in Miocene sediments of the Xisha Islands and their genetic model

NASA Astrophysics Data System (ADS)

Xu, Hong; Zhang, Weiwei; Wei, Kai; He, Qingkun; Jiang, Yunshui; Xu, Tingting; Jiang, Xuejun; Yan, Guijing; Song, Hongying; Wang, Jianghai

2018-01-01

Carbonate rocks are important reservoirs for global petroleum exploration. The largest oilfield in the South China Sea, Liuhua 11-1, is distributed in the massive carbonate reef area of the Zhujiang (Pearl) River Mouth Basin. Previous studies showed that one 802.17-m-long core from well Xichen-1 in the South China Sea mainly consisted of white and light gray-white organic reefs. Recently, a Miocene whole core (161.9 m long) of well Xiyong-2, near well Xichen-1, was found to contain six layers of yellowish brown, light yellowish gray, iron black, or light yellowish gray-white organic reefs. Scanning electron microscope images of these layers reveal a typical ferroan dolomite rich in Fe (up to 29%), with the high concentrations of Mn, Cu, W, Zn, Cr, Ni, and Co. Systematic X-ray powder diffraction analysis yields a 1.9-6.1 match in phase ratio with ankerite, 5.4-26.9 with dolomite, and zero with calcite, which indicate that the samples can be classified as ferroan dolomite. The iron and heavy metals are inferred to be originated from multiple volcanic eruptions of Gaojianshi Island in the Dongdao Atoll during the middle-late Miocene. These elements were dissolved in seawater, likely as a sol, and carried to Yongxing Island in the Xuande Atoll by sea currents and tides enhanced by prevailing winds, and deposited as a part of the sedimentation process in the study area. The ferroan dolomite has Sr content of (125-285)×10-6, which is lower than the accepted Sr boundary value of dolomite. This finding suggests that dolomitization occurred during large-scale global glacial regression in the late Miocene. The isolated Xisha carbonate platform, exposed to air, underwent freshwater leaching and dolomitization induced by mixed water, and caused the extensive Fe-Mg exchange along the organic reef profile to form ankerite and ferroan dolomite. These results may help to understand paleoceanographic environmental changes in the South China Sea during the Miocene.

Brain tumor classification and segmentation using sparse coding and dictionary learning.

PubMed

Salman Al-Shaikhli, Saif Dawood; Yang, Michael Ying; Rosenhahn, Bodo

2016-08-01

This paper presents a novel fully automatic framework for multi-class brain tumor classification and segmentation using a sparse coding and dictionary learning method. The proposed framework consists of two steps: classification and segmentation. The classification of the brain tumors is based on brain topology and texture. The segmentation is based on voxel values of the image data. Using K-SVD, two types of dictionaries are learned from the training data and their associated ground truth segmentation: feature dictionary and voxel-wise coupled dictionaries. The feature dictionary consists of global image features (topological and texture features). The coupled dictionaries consist of coupled information: gray scale voxel values of the training image data and their associated label voxel values of the ground truth segmentation of the training data. For quantitative evaluation, the proposed framework is evaluated using different metrics. The segmentation results of the brain tumor segmentation (MICCAI-BraTS-2013) database are evaluated using five different metric scores, which are computed using the online evaluation tool provided by the BraTS-2013 challenge organizers. Experimental results demonstrate that the proposed approach achieves an accurate brain tumor classification and segmentation and outperforms the state-of-the-art methods.

Patient exposure dose for chest and skull radiographies in Mazandaran hospitals.

PubMed

Etemadinezhad, Siavash; Rahimi, Seyed Ali

2010-01-01

Radiographic techniques are essential methods of diagnosis, and their use has been increased, especially with the development of the new technologies. Inappropriate administration of these techniques may put both the patients and personnel at unnecessary risks. The objective of this research was to measure the skin dose of chest and skull radiographies used in Mazandaran hospitals and to compare these doses with national and international standards. In this cross-sectional study, six X-ray generators at six hospitals affiliated to Mazandaran University of Medical Sciences were included. One hundred and twenty patients referred to the radiology wards for radiographic examinations of chest and skull with normal body mass index (BMI) were selected (20 patients for each radiography unit). The generators were matched for mAs, kvp, type of amplifier sheets, and technical conditions as much as possible. Calibrated thermo luminescence dosimeters (TLD-USA, Lif-100) were used to measure the skin dose by placing them on the patients' back and the absorbed doses by TLDs were read by a TLD reader (model: Harshuu, TLD3500, Japan). The mean values of the skin dose were 0.51 mGray for posteroanterior (PA), chest X-ray (CXR), 3.36 mGray for lateral CXR, 7.25 mGray for anterroposterior (AP) or PA skull X-rays, and 7.59 mGray for lateral skull X-rays. The measured values were higher than the national and international standards. The results of this research revealed that the conditions of the X-ray generators should be monitored and modified periodically. Modifying the X-ray generators plus improving technicians' skills would, to some extent, reduce the radiation exposure of the patients.

Parameter optimization of parenchymal texture analysis for prediction of false-positive recalls from screening mammography

NASA Astrophysics Data System (ADS)

Ray, Shonket; Keller, Brad M.; Chen, Jinbo; Conant, Emily F.; Kontos, Despina

2016-03-01

This work details a methodology to obtain optimal parameter values for a locally-adaptive texture analysis algorithm that extracts mammographic texture features representative of breast parenchymal complexity for predicting falsepositive (FP) recalls from breast cancer screening with digital mammography. The algorithm has two components: (1) adaptive selection of localized regions of interest (ROIs) and (2) Haralick texture feature extraction via Gray- Level Co-Occurrence Matrices (GLCM). The following parameters were systematically varied: mammographic views used, upper limit of the ROI window size used for adaptive ROI selection, GLCM distance offsets, and gray levels (binning) used for feature extraction. Each iteration per parameter set had logistic regression with stepwise feature selection performed on a clinical screening cohort of 474 non-recalled women and 68 FP recalled women; FP recall prediction was evaluated using area under the curve (AUC) of the receiver operating characteristic (ROC) and associations between the extracted features and FP recall were assessed via odds ratios (OR). A default instance of mediolateral (MLO) view, upper ROI size limit of 143.36 mm (2048 pixels2), GLCM distance offset combination range of 0.07 to 0.84 mm (1 to 12 pixels) and 16 GLCM gray levels was set. The highest ROC performance value of AUC=0.77 [95% confidence intervals: 0.71-0.83] was obtained at three specific instances: the default instance, upper ROI window equal to 17.92 mm (256 pixels2), and gray levels set to 128. The texture feature of sum average was chosen as a statistically significant (p<0.05) predictor and associated with higher odds of FP recall for 12 out of 14 total instances.

Detection of pre-symptomatic rose powdery-mildew and gray-mold diseases based on thermal vision

NASA Astrophysics Data System (ADS)

Jafari, M.; Minaei, S.; Safaie, N.

2017-09-01

Roses are the most important plants in ornamental horticulture. Roses are susceptible to a number of phytopathogenic diseases. Among the most serious diseases of rose, powdery mildew (Podosphaera pannosa var. rosae) and gray mold (Botrytis cinerea) are widespread which require considerable attention. In this study, the potential of implementing thermal imaging to detect the pre-symptomatic appearance of these fungal diseases was investigated. Effects of powdery mildew and gray mold diseases on rose plants (Rosa hybrida L.) were examined by two experiments conducted in a growth chamber. To classify the healthy and infected plants, feature selection was carried out and the best extracted thermal features with the largest linguistic hedge values were chosen. Two neuro-fuzzy classifiers were trained to distinguish between the healthy and infected plants. Best estimation rates of 92.55% and 92.3% were achieved in training and testing the classifier with 8 clusters in order to identify the leaves infected with powdery mildew. In addition, the best estimation rates of 97.5% and 92.59% were achieved in training and testing the classifier with 4 clusters to identify the gray mold disease on flowers. Performance of the designed neuro-fuzzy classifiers were evaluated with the thermal images captured using an automatic imaging setup. Best correct estimation rates of 69% and 80% were achieved (on the second day post-inoculation) for pre-symptomatic appearance detection of powdery mildew and gray mold diseases, respectively.

Early Mars may have had a methanol ocean

NASA Astrophysics Data System (ADS)

Tang, Yan; Chen, Qianwang; Huang, Yujie

2006-01-01

The detection of gray crystalline hematite deposits on Mars by Thermal Emission Spectrometer (TES) has been used to argue for the presence of liquid water on Mars in the distant past. By methanol-thermal treatment of anhydrous FeCl 3 at low temperatures (70-160 °C), crystalline gray hematite with layered structure was synthesized, based on this result an alternative explanation for the origin of martian hematite deposits is suggested. Methane could be abundant in the early martian atmosphere; process such as photochemical oxidation of methane could result in the formation of ocean or pool of organic compounds such as methanol, which provides an environment for the formation of large-scale hematite deposits on Mars.

Genomic diversity and phylogenetic relationships in the genus Parthenium (Asteraceae)

USDA-ARS?s Scientific Manuscript database

Guayule (Parthenium argentatum A. Gray) is a perennial hardwood shrub native to the North American Chihuahuan Desert that holds promise as a sustainable source of natural rubber and hypoallergenic latex. The improvement of guayule for commercial-scale production could be potentially accelerated thro...

High-dimensional free-space optical communications based on orbital angular momentum coding

NASA Astrophysics Data System (ADS)

Zou, Li; Gu, Xiaofan; Wang, Le

2018-03-01

In this paper, we propose a high-dimensional free-space optical communication scheme using orbital angular momentum (OAM) coding. In the scheme, the transmitter encodes N-bits information by using a spatial light modulator to convert a Gaussian beam to a superposition mode of N OAM modes and a Gaussian mode; The receiver decodes the information through an OAM mode analyser which consists of a MZ interferometer with a rotating Dove prism, a photoelectric detector and a computer carrying out the fast Fourier transform. The scheme could realize a high-dimensional free-space optical communication, and decodes the information much fast and accurately. We have verified the feasibility of the scheme by exploiting 8 (4) OAM modes and a Gaussian mode to implement a 256-ary (16-ary) coding free-space optical communication to transmit a 256-gray-scale (16-gray-scale) picture. The results show that a zero bit error rate performance has been achieved.

Emotions in "Black and White" or Shades of Gray? How We Think About Emotion Shapes Our Perception and Neural Representation of Emotion.

PubMed

Satpute, Ajay B; Nook, Erik C; Narayanan, Sandhya; Shu, Jocelyn; Weber, Jochen; Ochsner, Kevin N

2016-11-01

The demands of social life often require categorically judging whether someone's continuously varying facial movements express "calm" or "fear," or whether one's fluctuating internal states mean one feels "good" or "bad." In two studies, we asked whether this kind of categorical, "black and white," thinking can shape the perception and neural representation of emotion. Using psychometric and neuroimaging methods, we found that (a) across participants, judging emotions using a categorical, "black and white" scale relative to judging emotions using a continuous, "shades of gray," scale shifted subjective emotion perception thresholds; (b) these shifts corresponded with activity in brain regions previously associated with affective responding (i.e., the amygdala and ventral anterior insula); and (c) connectivity of these regions with the medial prefrontal cortex correlated with the magnitude of categorization-related shifts. These findings suggest that categorical thinking about emotions may actively shape the perception and neural representation of the emotions in question. © The Author(s) 2016.

A comparison of methods to evaluate gray scale response of tomosynthesis systems using a software breast phantom

NASA Astrophysics Data System (ADS)

Sousa, Maria A. Z.; Bakic, Predrag R.; Schiabel, Homero; Maidment, Andrew D. A.

2017-03-01

Digital breast tomosynthesis (DBT) has been shown to be an effective imaging tool for breast cancer diagnosis as it provides three-dimensional images of the breast with minimal tissue overlap. The quality of the reconstructed image depends on many factors that can be assessed using uniform or realistic phantoms. In this paper, we created four models of phantoms using an anthropomorphic software breast phantom and compared four methods to evaluate the gray scale response in terms of the contrast, noise and detectability of adipose and glandular tissues binarized according to phantom ground truth. For each method, circular regions of interest (ROIs) were selected with various sizes, quantity and positions inside a square area in the phantom. We also estimated the percent density of the simulated breast and the capability of distinguishing both tissues by receiver operating characteristic (ROC) analysis. Results shows a sensitivity of the methods to the ROI size, placement and to the slices considered.

Comparison between a new computer program and the reference software for gray-scale median analysis of atherosclerotic carotid plaques.

PubMed

Casella, Ivan Benaduce; Fukushima, Rodrigo Bono; Marques, Anita Battistini de Azevedo; Cury, Marcus Vinícius Martins; Presti, Calógero

2015-03-01

To compare a new dedicated software program and Adobe Photoshop for gray-scale median (GSM) analysis of B-mode images of carotid plaques. A series of 42 carotid plaques generating ≥50% diameter stenosis was evaluated by a single observer. The best segment for visualization of internal carotid artery plaque was identified on a single longitudinal view and images were recorded in JPEG format. Plaque analysis was performed by both programs. After normalization of image intensity (blood = 0, adventitial layer = 190), histograms were obtained after manual delineation of plaque. Results were compared with nonparametric Wilcoxon signed rank test and Kendall tau-b correlation analysis. GSM ranged from 00 to 100 with Adobe Photoshop and from 00 to 96 with IMTPC, with a high grade of similarity between image pairs, and a highly significant correlation (R = 0.94, p < .0001). IMTPC software appears suitable for the GSM analysis of carotid plaques. © 2014 Wiley Periodicals, Inc.

Morphological filtering and multiresolution fusion for mammographic microcalcification detection

NASA Astrophysics Data System (ADS)

Chen, Lulin; Chen, Chang W.; Parker, Kevin J.

1997-04-01

Mammographic images are often of relatively low contrast and poor sharpness with non-stationary background or clutter and are usually corrupted by noise. In this paper, we propose a new method for microcalcification detection using gray scale morphological filtering followed by multiresolution fusion and present a unified general filtering form called the local operating transformation for whitening filtering and adaptive thresholding. The gray scale morphological filters are used to remove all large areas that are considered as non-stationary background or clutter variations, i.e., to prewhiten images. The multiresolution fusion decision is based on matched filter theory. In addition to the normal matched filter, the Laplacian matched filter which is directly related through the wavelet transforms to multiresolution analysis is exploited for microcalcification feature detection. At the multiresolution fusion stage, the region growing techniques are used in each resolution level. The parent-child relations between resolution levels are adopted to make final detection decision. FROC is computed from test on the Nijmegen database.

The effects of adjunctive intranasal oxytocin in patients with schizophrenia.

PubMed

Ota, Miho; Yoshida, Sumiko; Nakata, Masanori; Yada, Toshihiko; Kunugi, Hiroshi

2018-01-01

Both human and animal studies have suggested that oxytocin may have therapeutic potential in the treatment of schizophrenia. We evaluated the effects of intranasal oxytocin on cognition and its predictive factors in Japanese patients with schizophrenia. Subjects were 16 chronic schizophrenia patients who underwent intranasal oxytocin treatment for 3 months and were assessed for changes in severity of clinical symptoms and cognitions. Fifteen of the 16 subjects underwent 3-Tesla magnetic resonance imaging. Oxytocin significantly reduced scores on the positive and negative syndrome scale, especially on the negative symptoms. As for cognition, there was an improvement of the verbal fluency. Furthermore, the change of the negative score in positive and negative syndrome scale showed a negative correlation with the gray matter volumes of the right insula and left cingulate cortex. Our results indicate that daily administration of intranasal oxytocin may be effective for ameliorating clinical symptoms and cognitive functions in chronic schizophrenia patients, and this improvement may be related to the gray matter volume of the right insula and left cingulate cortex.

Museum lighting: Why are some illuminants preferred?

NASA Astrophysics Data System (ADS)

Scuello, Michael; Abramov, Israel; Gordon, James; Weintraub, Steven

2004-02-01

We had shown earlier that viewers prefer to look at artworks under illuminants of ~3600 K. In the latest paper we tested the hypothesis that the preferred illuminant is one that appears neither warm nor cool and repeated the settings at each of four illuminances to test the stability of the findings. Observers looked at a neutral white reflectance standard hung on a matte-gray wall lit by overhead banks of lamps whose combined value could be adjusted continuously between 3000 and 4400 K while illuminance was kept constant. Illuminance ranged from 50 to 2000 lux. Observers adjusted color temperature until they were satisfied that the standard looked neither warm nor cool. The mean for a group of eight observers was approximately 3700, independent of intensity; this corresponds to a dominant wavelength of ~580 nm. In a separate study four observers scaled the apparent warmth or coolness of flashes of equiluminant monochromatic lights; the warm-cool transition was between 560 and 580 nm; warmness was completely predicted by the perceived redness of each light as derived from hue and saturation scaling functions from the same group.

The place of white in a world of grays: a double-anchoring theory of lightness perception.

PubMed

Bressan, Paola

2006-07-01

The specific gray shades in a visual scene can be derived from relative luminance values only when an anchoring rule is followed. The double-anchoring theory I propose in this article, as a development of the anchoring theory of Gilchrist et al. (1999), assumes that any given region (a) belongs to one or more frameworks, created by Gestalt grouping principles, and (b) is independently anchored, within each framework, to both the highest luminance and the surround luminance. The region's final lightness is a weighted average of the values computed, relative to both anchors, in all frameworks. The new model accounts not only for all lightness illusions that are qualitatively explained by the anchoring theory but also for a number of additional effects, and it does so quantitatively, with the support of mathematical simulations. ((c) 2006 APA, all rights reserved).

White-matter functional networks changes in patients with schizophrenia.

PubMed

Jiang, Yuchao; Luo, Cheng; Li, Xuan; Li, Yingjia; Yang, Hang; Li, Jianfu; Chang, Xin; Li, Hechun; Yang, Huanghao; Wang, Jijun; Duan, Mingjun; Yao, Dezhong

2018-04-13

Resting-state functional MRI (rsfMRI) is a useful technique for investigating the functional organization of human gray-matter in neuroscience and neuropsychiatry. Nevertheless, most studies have demonstrated the functional connectivity and/or task-related functional activity in the gray-matter. White-matter functional networks have been investigated in healthy subjects. Schizophrenia has been hypothesized to be a brain disorder involving insufficient or ineffective communication associated with white-matter abnormalities. However, previous studies have mainly examined the structural architecture of white-matter using MRI or diffusion tensor imaging and failed to uncover any dysfunctional connectivity within the white-matter on rsfMRI. The current study used rsfMRI to evaluate white-matter functional connectivity in a large cohort of ninety-seven schizophrenia patients and 126 healthy controls. Ten large-scale white-matter networks were identified by a cluster analysis of voxel-based white-matter functional connectivity and classified into superficial, middle and deep layers of networks. Evaluation of the spontaneous oscillation of white-matter networks and the functional connectivity between them showed that patients with schizophrenia had decreased amplitudes of low-frequency oscillation and increased functional connectivity in the superficial perception-motor networks. Additionally, we examined the interactions between white-matter and gray-matter networks. The superficial perception-motor white-matter network had decreased functional connectivity with the cortical perception-motor gray-matter networks. In contrast, the middle and deep white-matter networks had increased functional connectivity with the superficial perception-motor white-matter network and the cortical perception-motor gray-matter network. Thus, we presumed that the disrupted association between the gray-matter and white-matter networks in the perception-motor system may be compensated for through the middle-deep white-matter networks, which may be the foundation of the extensively disrupted connections in schizophrenia. Copyright © 2018 Elsevier Inc. All rights reserved.

Multiple cortical thickness sub-networks and cognitive impairments in first episode, drug naïve patients with late life depression: A graph theory analysis.

PubMed

Shin, Jeong-Hyeon; Um, Yu Hyun; Lee, Chang Uk; Lim, Hyun Kook; Seong, Joon-Kyung

2018-03-15

Coordinated and pattern-wise changes in large scale gray matter structural networks reflect neural circuitry dysfunction in late life depression (LLD), which in turn is associated with emotional dysregulation and cognitive impairments. However, due to methodological limitations, there have been few attempts made to identify individual-level structural network properties or sub-networks that are involved in important brain functions in LLD. In this study, we sought to construct individual-level gray matter structural networks using average cortical thicknesses of several brain areas to investigate the characteristics of the gray matter structural networks in normal controls and LLD patients. Additionally, we investigated the structural sub-networks correlated with several clinical measurements including cognitive impairment and depression severity. We observed that small worldness, clustering coefficients, global and local efficiency, and hub structures in the brains of LLD patients were significantly different from healthy controls. We further found that a sub-network including the anterior cingulate, dorsolateral prefrontal cortex and superior prefrontal cortex is significantly associated with attention control and executive function. The severity of depression was associated with the sub-networks comprising the salience network, including the anterior cingulate and insula. We investigated cortico-cortical connectivity, but omitted the subcortical structures such as the striatum and thalamus. We report differences in patterns between several clinical measurements and sub-networks from large-scale and individual-level cortical thickness networks in LLD. Copyright © 2018 Elsevier B.V. All rights reserved.

Associations between IQ, total and regional brain volumes, and demography in a large normative sample of healthy children and adolescents.

PubMed

Lange, Nicholas; Froimowitz, Michael P; Bigler, Erin D; Lainhart, Janet E

2010-01-01

In the course of efforts to establish quantitative norms for healthy brain development by magnetic resonance imaging (MRI) (Brain Development Cooperative Group, 2006), previously unreported associations of parental education and temporal and frontal lobe volumes with full scale IQ and its verbal and performance subscales were discovered. Our findings were derived from the largest, most representative MRI sample to date of healthy children and adolescents, ages 4 years 10 months to 18 years 4 months. We first find that parental education has a strong association with IQ in children that is not mediated by total or regional brain volumes. Second, we find that our observed correlations between temporal gray matter, temporal white matter and frontal white matter volumes with full scale IQ, between 0.14 to 0.27 in children and adolescents, are due in large part to their correlations with performance IQ and not verbal IQ. The volumes of other lobar gray and white matter, subcortical gray matter (thalamus, caudate nucleus, putamen, and globus pallidus), cerebellum, and brainstem do not contribute significantly to IQ variation. Third, we find that head circumference is an insufficient index of cerebral volume in typically developing older children and adolescents. The relations between total and regional brain volumes and IQ can best be discerned when additional variables known to be associated with IQ, especially parental education and other demographic measures, are considered concurrently.

VizieR Online Data Catalog: Radial velocities of δ Sagittae (Pugh+, 2015)

NASA Astrophysics Data System (ADS)

Pugh, T.; Gray, D. F.; Griffin, R. F.

2018-01-01

28 spectra were obtained by Gray and Pugh between 2008 July and 2010 October (MJD 2454674-2455479) with the high-resolution (R~100000) coude spectrograph of the Elginfield Observatory of Western University (Gray 2009ApJ...697.1032G). The signal-to-noise ratios in the continuum, estimated from the photon counts, ranged from 152 to 314 with a mean of 220. The spectrograph has a dispersion of ~0.013 Å/mm and can reach a radial-velocity precision of 25 m/s by reference to water vapour lines inside the spectrograph (Gray & Brown 2006PASP..118.1112G). In the current case our measurement errors (based on exposures taken within a few nights of one another) range from 27 to 160 m/s, with a mean value of 90 m/s. The radial velocities were determined by measuring the positions of the spectral lines at 85 per cent of the line depth for 15 neutral metal lines in the λ6250-Å region. (1 data file).

Einstein Observations of Galactic supernova remnants

NASA Technical Reports Server (NTRS)

Seward, Frederick D.

1990-01-01

This paper summarizes the observations of Galactic supernova remnants with the imaging detectors of the Einstein Observatory. X-ray surface brightness contours of 47 remnants are shown together with gray-scale pictures. Count rates for these remnants have been derived and are listed for the HRI, IPC, and MPC detectors.

A Glance at Microsatellite Motifs from 454 Sequencing Reads of Watermelon Genomic DNA

USDA-ARS?s Scientific Manuscript database

A single 454 (Life Sciences Sequencing Technology) run of Charleston Gray watermelon (Citrullus lanatus var. lanatus) genomic DNA was performed and sequence data were assembled. A large scale identification of simple sequence repeat (SSR) was performed and SSR sequence data were used for the develo...

Generalized image contrast enhancement technique based on the Heinemann contrast discrimination model

NASA Astrophysics Data System (ADS)

Liu, Hong; Nodine, Calvin F.

1996-07-01

This paper presents a generalized image contrast enhancement technique, which equalizes the perceived brightness distribution based on the Heinemann contrast discrimination model. It is based on the mathematically proven existence of a unique solution to a nonlinear equation, and is formulated with easily tunable parameters. The model uses a two-step log-log representation of luminance contrast between targets and surround in a luminous background setting. The algorithm consists of two nonlinear gray scale mapping functions that have seven parameters, two of which are adjustable Heinemann constants. Another parameter is the background gray level. The remaining four parameters are nonlinear functions of the gray-level distribution of the given image, and can be uniquely determined once the previous three are set. Tests have been carried out to demonstrate the effectiveness of the algorithm for increasing the overall contrast of radiology images. The traditional histogram equalization can be reinterpreted as an image enhancement technique based on the knowledge of human contrast perception. In fact, it is a special case of the proposed algorithm.

New algorithm for detecting smaller retinal blood vessels in fundus images

NASA Astrophysics Data System (ADS)

LeAnder, Robert; Bidari, Praveen I.; Mohammed, Tauseef A.; Das, Moumita; Umbaugh, Scott E.

2010-03-01

About 4.1 million Americans suffer from diabetic retinopathy. To help automatically diagnose various stages of the disease, a new blood-vessel-segmentation algorithm based on spatial high-pass filtering was developed to automatically segment blood vessels, including the smaller ones, with low noise. Methods: Image database: Forty, 584 x 565-pixel images were collected from the DRIVE image database. Preprocessing: Green-band extraction was used to obtain better contrast, which facilitated better visualization of retinal blood vessels. A spatial highpass filter of mask-size 11 was applied. A histogram stretch was performed to enhance contrast. A median filter was applied to mitigate noise. At this point, the gray-scale image was converted to a binary image using a binary thresholding operation. Then, a NOT operation was performed by gray-level value inversion between 0 and 255. Postprocessing: The resulting image was AND-ed with its corresponding ring mask to remove the outer-ring (lens-edge) artifact. At this point, the above algorithm steps had extracted most of the major and minor vessels, with some intersections and bifurcations missing. Vessel segments were reintegrated using the Hough transform. Results: After applying the Hough transform, both the average peak SNR and the RMS error improved by 10%. Pratt's Figure of Merit (PFM) was decreased by 6%. Those averages were better than [1] by 10-30%. Conclusions: The new algorithm successfully preserved the details of smaller blood vessels and should prove successful as a segmentation step for automatically identifying diseases that affect retinal blood vessels.

Effect of multiphase radiation on coal combustion in a pulverized coal jet flame

NASA Astrophysics Data System (ADS)

Wu, Bifen; Roy, Somesh P.; Zhao, Xinyu; Modest, Michael F.

2017-08-01

The accurate modeling of coal combustion requires detailed radiative heat transfer models for both gaseous combustion products and solid coal particles. A multiphase Monte Carlo ray tracing (MCRT) radiation solver is developed in this work to simulate a laboratory-scale pulverized coal flame. The MCRT solver considers radiative interactions between coal particles and three major combustion products (CO2, H2O, and CO). A line-by-line spectral database for the gas phase and a size-dependent nongray correlation for the solid phase are employed to account for the nongray effects. The flame structure is significantly altered by considering nongray radiation and the lift-off height of the flame increases by approximately 35%, compared to the simulation without radiation. Radiation is also found to affect the evolution of coal particles considerably as it takes over as the dominant mode of heat transfer for medium-to-large coal particles downstream of the flame. To investigate the respective effects of spectral models for the gas and solid phases, a Planck-mean-based gray gas model and a size-independent gray particle model are applied in a frozen-field analysis of a steady-state snapshot of the flame. The gray gas approximation considerably underestimates the radiative source terms for both the gas phase and the solid phase. The gray coal approximation also leads to under-prediction of the particle emission and absorption. However, the level of under-prediction is not as significant as that resulting from the employment of the gray gas model. Finally, the effect of the spectral property of ash on radiation is also investigated and found to be insignificant for the present target flame.

Blood Pressure Control in Aging Predicts Cerebral Atrophy Related to Small-Vessel White Matter Lesions.

PubMed

Kern, Kyle C; Wright, Clinton B; Bergfield, Kaitlin L; Fitzhugh, Megan C; Chen, Kewei; Moeller, James R; Nabizadeh, Nooshin; Elkind, Mitchell S V; Sacco, Ralph L; Stern, Yaakov; DeCarli, Charles S; Alexander, Gene E

2017-01-01

Cerebral small-vessel damage manifests as white matter hyperintensities and cerebral atrophy on brain MRI and is associated with aging, cognitive decline and dementia. We sought to examine the interrelationship of these imaging biomarkers and the influence of hypertension in older individuals. We used a multivariate spatial covariance neuroimaging technique to localize the effects of white matter lesion load on regional gray matter volume and assessed the role of blood pressure control, age and education on this relationship. Using a case-control design matching for age, gender, and educational attainment we selected 64 participants with normal blood pressure, controlled hypertension or uncontrolled hypertension from the Northern Manhattan Study cohort. We applied gray matter voxel-based morphometry with the scaled subprofile model to (1) identify regional covariance patterns of gray matter volume differences associated with white matter lesion load, (2) compare this relationship across blood pressure groups, and (3) relate it to cognitive performance. In this group of participants aged 60-86 years, we identified a pattern of reduced gray matter volume associated with white matter lesion load in bilateral temporal-parietal regions with relative preservation of volume in the basal forebrain, thalami and cingulate cortex. This pattern was expressed most in the uncontrolled hypertension group and least in the normotensives, but was also more evident in older and more educated individuals. Expression of this pattern was associated with worse performance in executive function and memory. In summary, white matter lesions from small-vessel disease are associated with a regional pattern of gray matter atrophy that is mitigated by blood pressure control, exacerbated by aging, and associated with cognitive performance.

Evaluation of cortical local field potential diffusion in stereotactic electro-encephalography recordings: A glimpse on white matter signal.

PubMed

Mercier, Manuel R; Bickel, Stephan; Megevand, Pierre; Groppe, David M; Schroeder, Charles E; Mehta, Ashesh D; Lado, Fred A

2017-02-15

While there is a strong interest in meso-scale field potential recording using intracranial electroencephalography with penetrating depth electrodes (i.e. stereotactic EEG or S-EEG) in humans, the signal recorded in the white matter remains ignored. White matter is generally considered electrically neutral and often included in the reference montage. Moreover, re-referencing electrophysiological data is a critical preprocessing choice that could drastically impact signal content and consequently the results of any given analysis. In the present stereotactic electroencephalography study, we first illustrate empirically the consequences of commonly used references (subdermal, white matter, global average, local montage) on inter-electrode signal correlation. Since most of these reference montages incorporate white matter signal, we next consider the difference between signals recorded in cortical gray matter and white matter. Our results reveal that electrode contacts located in the white matter record a mixture of activity, with part arising from the volume conduction (zero time delay) of activity from nearby gray matter. Furthermore, our analysis shows that white matter signal may be correlated with distant gray matter signal. While residual passive electrical spread from nearby matter may account for this relationship, our results suggest the possibility that this long distance correlation arises from the white matter fiber tracts themselves (i.e. activity from distant gray matter traveling along axonal fibers with time lag larger than zero); yet definitive conclusions about the origin of the white matter signal would require further experimental substantiation. By characterizing the properties of signals recorded in white matter and in gray matter, this study illustrates the importance of including anatomical prior knowledge when analyzing S-EEG data. Copyright © 2017 Elsevier Inc. All rights reserved.

Illumination normalization of face image based on illuminant direction estimation and improved Retinex.

PubMed

Yi, Jizheng; Mao, Xia; Chen, Lijiang; Xue, Yuli; Rovetta, Alberto; Caleanu, Catalin-Daniel

2015-01-01

Illumination normalization of face image for face recognition and facial expression recognition is one of the most frequent and difficult problems in image processing. In order to obtain a face image with normal illumination, our method firstly divides the input face image into sixteen local regions and calculates the edge level percentage in each of them. Secondly, three local regions, which meet the requirements of lower complexity and larger average gray value, are selected to calculate the final illuminant direction according to the error function between the measured intensity and the calculated intensity, and the constraint function for an infinite light source model. After knowing the final illuminant direction of the input face image, the Retinex algorithm is improved from two aspects: (1) we optimize the surround function; (2) we intercept the values in both ends of histogram of face image, determine the range of gray levels, and stretch the range of gray levels into the dynamic range of display device. Finally, we achieve illumination normalization and get the final face image. Unlike previous illumination normalization approaches, the method proposed in this paper does not require any training step or any knowledge of 3D face and reflective surface model. The experimental results using extended Yale face database B and CMU-PIE show that our method achieves better normalization effect comparing with the existing techniques.

Estimating melanin location in the pigmented skin lesions by hue-saturation-lightness color space values of dermoscopic images.

PubMed

Sakai, Hiroshi; Ando, Yoshimi; Ikinaga, Kuniko; Tanaka, Masaru

2017-05-01

The depth of melanin in the skin can be estimated roughly by observation of the color exhibited on dermoscopy. Currently, there are no objective methods to estimate it. The aim of the present study was to clarify the relationship between the depth of melanin in the skin and the color variation exhibited, and to objectively estimate the 3-D location of melanin in the pigmented skin lesions from dermoscopic images. Representative colors in dermoscopic images of acral compound nevus, Spitz nevus and blue nevus were evaluated by the subjectively perceived color on dermoscopy and objective values in hue-saturation-lightness color space values. Brown colors due to small quantities of superficial melanin in the skin had high saturation and low lightness values, whereas black colors due to large quantities of superficial melanin had low saturation and low lightness values. On the other hand, colors due to melanin in the dermis were perceived as blue-gray on dermoscopy, but extracted colors showed gray-brown hue and intermediate saturation and high lightness values. In all cases, extracted representative colors of pigmented skin lesions had similar hue values within the red-orange range. Objective estimation of the 3-D location of melanin in the pigmented skin lesions is possible by the saturation and lightness values of the colors extracted from dermoscopic images. Subjectively perceived colors of melanin, especially in the dermis, can be modified by the surrounding environment effect and blue color perception. © 2017 Japanese Dermatological Association.

Threshold secret sharing scheme based on phase-shifting interferometry.

PubMed

Deng, Xiaopeng; Shi, Zhengang; Wen, Wei

2016-11-01

We propose a new method for secret image sharing with the (3,N) threshold scheme based on phase-shifting interferometry. The secret image, which is multiplied with an encryption key in advance, is first encrypted by using Fourier transformation. Then, the encoded image is shared into N shadow images based on the recording principle of phase-shifting interferometry. Based on the reconstruction principle of phase-shifting interferometry, any three or more shadow images can retrieve the secret image, while any two or fewer shadow images cannot obtain any information of the secret image. Thus, a (3,N) threshold secret sharing scheme can be implemented. Compared with our previously reported method, the algorithm of this paper is suited for not only a binary image but also a gray-scale image. Moreover, the proposed algorithm can obtain a larger threshold value t. Simulation results are presented to demonstrate the feasibility of the proposed method.

Local gray level S-curve transformation - A generalized contrast enhancement technique for medical images.

PubMed

Gandhamal, Akash; Talbar, Sanjay; Gajre, Suhas; Hani, Ahmad Fadzil M; Kumar, Dileep

2017-04-01

Most medical images suffer from inadequate contrast and brightness, which leads to blurred or weak edges (low contrast) between adjacent tissues resulting in poor segmentation and errors in classification of tissues. Thus, contrast enhancement to improve visual information is extremely important in the development of computational approaches for obtaining quantitative measurements from medical images. In this research, a contrast enhancement algorithm that applies gray-level S-curve transformation technique locally in medical images obtained from various modalities is investigated. The S-curve transformation is an extended gray level transformation technique that results into a curve similar to a sigmoid function through a pixel to pixel transformation. This curve essentially increases the difference between minimum and maximum gray values and the image gradient, locally thereby, strengthening edges between adjacent tissues. The performance of the proposed technique is determined by measuring several parameters namely, edge content (improvement in image gradient), enhancement measure (degree of contrast enhancement), absolute mean brightness error (luminance distortion caused by the enhancement), and feature similarity index measure (preservation of the original image features). Based on medical image datasets comprising 1937 images from various modalities such as ultrasound, mammograms, fluorescent images, fundus, X-ray radiographs and MR images, it is found that the local gray-level S-curve transformation outperforms existing techniques in terms of improved contrast and brightness, resulting in clear and strong edges between adjacent tissues. The proposed technique can be used as a preprocessing tool for effective segmentation and classification of tissue structures in medical images. Copyright © 2017 Elsevier Ltd. All rights reserved.

How much water is required for coal power generation: An analysis of gray and blue water footprints.

PubMed

Ma, Xiaotian; Yang, Donglu; Shen, Xiaoxu; Zhai, Yijie; Zhang, Ruirui; Hong, Jinglan

2018-04-28

Although water resource shortage is closely connected with coal-based electricity generation, relevant water footprint analyses remain limited. This study aims to address this limitation by conducting a water footprint analysis of coal-based electricity generation in China for the first time to inform decision-makers about how freshwater consumption and wastewater discharge can be reduced. In China, 1 kWh of electricity supply obtained 1.78 × 10 -3  m 3 of gray water footprint in 2015, and the value is 1.3 times the blue water footprint score of 1.35 × 10 -3  m 3 /kWh. Although water footprint of 1 kWh of electricity supply decreased, the national total gray water footprint increased significantly from 2006 to 2015 with increase in power generating capacity. An opposite trend was observed for blue water footprint. Indirect processes dominated the influence of gray water footprint, whereas direct freshwater consumption contributed 63.6% to blue water footprint. Ameliorating key processes, including transportation, direct freshwater consumption, direct air emissions, and coal washing could thus bring substantial environmental benefits. Moreover, phosphorus, mercury, hexavalent chromium, arsenic, COD, and BOD 5 were key substances of gray water footprint. Results indicated that the combination of railway and water transportation should be prioritized. The targeted transition toward high coal washing rate and pithead power plant development provides a possibility to relieve environmental burdens, but constraints on water resources in coal production sites have to be considered. Copyright © 2018 Elsevier B.V. All rights reserved.

Influence of parameter settings in voxel-based morphometry 8. Using DARTEL and region-of-interest on reproducibility in gray matter volumetry.

PubMed

Goto, M; Abe, O; Aoki, S; Hayashi, N; Miyati, T; Takao, H; Matsuda, H; Yamashita, F; Iwatsubo, T; Mori, H; Kunimatsu, A; Ino, K; Yano, K; Ohtomo, K

2015-01-01

To investigate whether reproducibility of gray matter volumetry is influenced by parameter settings for VBM 8 using Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL) with region-of-interest (ROI) analyses. We prepared three-dimensional T1-weighted magnetic resonance images (3D-T1WIs) of 21 healthy subjects. All subjects were imaged with each of five MRI systems. Voxel-based morphometry 8 (VBM 8) and WFU PickAtlas software were used for gray matter volumetry. The bilateral ROI labels used were those provided as default settings with the software: Frontal Lobe, Hippocampus, Occipital Lobe, Orbital Gyrus, Parietal Lobe, Putamen, and Temporal Lobe. All 3D-T1WIs were segmented to gray matter with six parameters of VBM 8, with each parameter having between three and eight selectable levels. Reproducibility was evaluated as the standard deviation (mm³) of measured values for the five MRI systems. Reproducibility was influenced by 'Bias regularization (BiasR)', 'Bias FWHM', and 'De-noising filter' settings, but not by 'MRF weighting', 'Sampling distance', or 'Warping regularization' settings. Reproducibility in BiasR was influenced by ROI. Superior reproducibility was observed in Frontal Lobe with the BiasR1 setting, and in Hippocampus, Parietal Lobe, and Putamen with the BiasR3*, BiasR1, and BiasR5 settings, respectively. Reproducibility of gray matter volumetry was influenced by parameter settings in VBM 8 using DARTEL and ROI. In multi-center studies, the use of appropriate settings in VBM 8 with DARTEL results in reduced scanner effect.

Pamela Gray-Hann | NREL

Science.gov Websites

Pamela Gray-Hann Photo of Pamela Gray-Hann Pamela Gray-Hann Project Support Specialist Pamela.Gray.hann@nrel.gov | 303-275-4626 Pamela Gray-Hann is a member of the Geospatial Data Science team within Pam Gray-Hann

Maternal Dietary Choline Status Influences Brain Gray and White Matter Development in Young Pigs

PubMed Central

Mudd, Austin T; Getty, Caitlyn M; Dilger, Ryan N

2018-01-01

Abstract Background Choline is an essential nutrient that is pivotal to proper brain development. Research in animal models suggests that perinatal choline deficiency influences neuron development in the hippocampus and cortex, yet these observations require invasive techniques. Objective This study aimed to characterize the effects of perinatal choline deficiency on gray and white matter development with the use of noninvasive neuroimaging techniques in young pigs. Methods During the last 64 d of the 114-d gestation period Yorkshire sows were provided with a choline-sufficient (CS) or choline-deficient (CD) diet, analyzed to contain 1214 mg or 483 mg total choline/kg diet, respectively. Upon farrowing, pigs (Sus scrofa domesticus) were allowed colostrum consumption for ≤48 h, were further stratified into postnatal treatment groups, and were provided either CS or CD milk replacers, analyzed to contain 1591 or 518 mg total choline/kg diet, respectively, for 28 d. At 30 d of age, pigs were subjected to MRI procedures to assess brain development. Gray and white matter development was assessed through voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) to assess the effects of prenatal and postnatal dietary choline status. Results VBM analysis indicated that prenatally CS pigs exhibited increased (P < 0.01) gray matter in the left and right cortex compared with prenatally CD pigs. Analysis of white matter indicated that prenatally CS pigs exhibited increased (P < 0.01) white matter in the internal capsule, putamen–globus pallidus, and right cortex compared with prenatally CD pigs. No postnatal effects (P > 0.05) of choline status were noted for VBM analyses of gray and white matter. TBSS also showed no significant effects (P > 0.05) of prenatal or postnatal choline status for diffusion values along white matter tracts. Conclusions Observations from this study suggest that prenatal choline deficiency results in altered cortical gray matter and reduced white matter in the internal capsule and putamen of young pigs. With the use of noninvasive neuroimaging techniques, results from our study indicate that prenatal choline deficiency greatly alters gray and white matter development in pigs, thereby providing a translational assessment that may be used in clinical populations.

A new species of bent-toed gecko, genus Cyrtodactylus Gray, 1827 (Reptilia: Squamata: Gekkonidae), from Jawa Timur Province, Java, Indonesia, with taxonomic remarks on C. fumosus (Müller, 1895).

PubMed

Hartmann, Lukas; Mecke, Sven; Kieckbusch, Max; Mader, Felix; Kaiser, Hinrich

2016-01-26

A new species of the gekkonid lizard genus Cyrtodactylus Gray, 1827 is described from Klakah, Lumajang Regency, Jawa Timur Province, Java, Indonesia. Cyrtodactylus klakahensis sp. nov. can be distinguished from all other congeners by the presence of (1) a deep precloacal groove in males, (2) three rows of enlarged precloacofemoral scales, of which the third row bears 37-38 pores in males, (3) three or four rows of enlarged scales between the precloacofemoral scale rows and the cloaca, forming distinct chevrons, (4) raised and strongly keeled dorsal tubercles in 15-19 rows at midbody, (5) an indistinct lateral fold, (6) 17-20 subdigital lamellae under the 4^th toe, and (7) subcaudal scales which are not transversely enlarged. Cyrtodactylus klakahensis sp. nov. is only the third bent-toed gecko species described from Java, indicating that the diversity of this genus on this island has been neglected in the past. Furthermore, we confirm that C. fumosus (Müller, 1895) is a species that possesses a precloacal groove in males and is most likely restricted to northern Sulawesi. That species is defined by a single female holotype (NMB-REPT 2662). Specimens in museum collections catalogued as C. fumosus from localities elsewhere are misidentified and likely represent undescribed species.

Assessing urban forest effects and values, Scranton's urban forest

Treesearch

David J. Nowak; Robert E. III Hoehn; Daniel E. Crane; Jack C. Stevens; Vincent Cotrone

2010-01-01

An analysis of trees in the urbanized portion of Scranton, PA, reveals that this area has about 1.2 million trees with canopies that cover 22.0 percent of the area. The most common tree species are red maple, gray birch, black cherry, northern red oak, and quaking aspen. Scranton's urban forest currently store about 93,300 tons of carbon valued at $1.9 million. In...

Gray Matter Pathology in MS: Neuroimaging and Clinical Correlations

PubMed Central

Honce, Justin Morris

2013-01-01

It is abundantly clear that there is extensive gray matter pathology occurring in multiple sclerosis. While attention to gray matter pathology was initially limited to studies of autopsy specimens and biopsies, the development of new MRI techniques has allowed assessment of gray matter pathology in vivo. Current MRI techniques allow the direct visualization of gray matter demyelinating lesions, the quantification of diffuse damage to normal appearing gray matter, and the direct measurement of gray matter atrophy. Gray matter demyelination (both focal and diffuse) and gray matter atrophy are found in the very earliest stages of multiple sclerosis and are progressive over time. Accumulation of gray matter damage has substantial impact on the lives of multiple sclerosis patients; a growing body of the literature demonstrates correlations between gray matter pathology and various measures of both clinical disability and cognitive impairment. The effect of disease modifying therapies on the rate accumulation of gray matter pathology in MS has been investigated. This review focuses on the neuroimaging of gray matter pathology in MS, the effect of the accumulation of gray matter pathology on clinical and cognitive disability, and the effect of disease-modifying agents on various measures of gray matter damage. PMID:23878736

Soil biochemical properties in brown and gray mine soils with and without hydroseeding

NASA Astrophysics Data System (ADS)

Thomas, C.; Sexstone, A.; Skousen, J.

2015-09-01

Surface coal mining in the eastern USA disturbs hundreds of hectares of land every year and removes valuable and ecologically diverse eastern deciduous forests. Reclamation involves restoring the landscape to approximate original contour, replacing the topsoil, and revegetating the site with trees and herbaceous species to a designated post-mining land use. Re-establishing an ecosystem of ecological and economic value as well as restoring soil quality on disturbed sites are the goals of land reclamation, and microbial properties of mine soils can be indicators of restoration success. Reforestation plots were constructed in 2007 using weathered brown sandstone or unweathered gray sandstone as topsoil substitutes to evaluate tree growth and soil properties at Arch Coal's Birch River mine in West Virginia, USA. All plots were planted with 12 hardwood tree species and subplots were hydroseeded with a herbaceous seed mix and fertilizer. After 6 years, the average tree volume index was nearly 10 times greater for trees grown in brown (3853 cm3) compared to gray mine soils (407 cm3). Average pH of brown mine soils increased from 4.7 to 5.0, while gray mine soils declined from 7.9 to 7.0. Hydroseeding doubled tree volume index and ground cover on both mine soils. Hydroseeding doubled microbial biomass carbon (MBC) on brown mine soils (8.7 vs. 17.5 mg kg-1), but showed no effect on gray mine soils (13.3 vs. 12.8 mg kg-1). Hydroseeding also increased the ratio of MBC to soil organic C in both soils and more than tripled the ratio for potentially mineralizable nitrogen (PMN) to total N. Brown mine soils were a better growth medium than gray mine soils and hydroseeding was an important component of reclamation due to improved biochemical properties and microbial activity in mine soils.

Fate of a gray soliton in a quenched Bose-Einstein condensate

NASA Astrophysics Data System (ADS)

Gamayun, O.; Bezvershenko, Yu. V.; Cheianov, V.

2015-03-01

We investigate the destiny of a gray soliton in a repulsive one-dimensional Bose-Einstein condensate undergoing a sudden quench of the nonlinearity parameter. The outcome of the quench is found to depend dramatically on the ratio η of the final and initial values of the speed of sound. For integer η the soliton splits into exactly 2 η -1 solitons. For noninteger η the soliton decays into multiple solitons and Bogoliubov modes. The case of integer η is analyzed in detail. The parameters of solitons in the out state are found explicitly. Our approach exploits the inverse scattering method and can be easily used for similar quenches in any classical integrable system.

Quantitative evaluation methods of skin condition based on texture feature parameters.

PubMed

Pang, Hui; Chen, Tianhua; Wang, Xiaoyi; Chang, Zhineng; Shao, Siqi; Zhao, Jing

2017-03-01

In order to quantitatively evaluate the improvement of the skin condition after using skin care products and beauty, a quantitative evaluation method for skin surface state and texture is presented, which is convenient, fast and non-destructive. Human skin images were collected by image sensors. Firstly, the median filter of the 3 × 3 window is used and then the location of the hairy pixels on the skin is accurately detected according to the gray mean value and color information. The bilinear interpolation is used to modify the gray value of the hairy pixels in order to eliminate the negative effect of noise and tiny hairs on the texture. After the above pretreatment, the gray level co-occurrence matrix (GLCM) is calculated. On the basis of this, the four characteristic parameters, including the second moment, contrast, entropy and correlation, and their mean value are calculated at 45 ° intervals. The quantitative evaluation model of skin texture based on GLCM is established, which can calculate the comprehensive parameters of skin condition. Experiments show that using this method evaluates the skin condition, both based on biochemical indicators of skin evaluation methods in line, but also fully consistent with the human visual experience. This method overcomes the shortcomings of the biochemical evaluation method of skin damage and long waiting time, also the subjectivity and fuzziness of the visual evaluation, which achieves the non-destructive, rapid and quantitative evaluation of skin condition. It can be used for health assessment or classification of the skin condition, also can quantitatively evaluate the subtle improvement of skin condition after using skin care products or stage beauty.

Automated geographic registration and radiometric correction for UAV-based mosaics

NASA Astrophysics Data System (ADS)

Thomasson, J. Alex; Shi, Yeyin; Sima, Chao; Yang, Chenghai; Cope, Dale A.

2017-05-01

Texas A and M University has been operating a large-scale, UAV-based, agricultural remote-sensing research project since 2015. To use UAV-based images in agricultural production, many high-resolution images must be mosaicked together to create an image of an agricultural field. Two key difficulties to science-based utilization of such mosaics are geographic registration and radiometric calibration. In our current research project, image files are taken to the computer laboratory after the flight, and semi-manual pre-processing is implemented on the raw image data, including ortho-mosaicking and radiometric calibration. Ground control points (GCPs) are critical for high-quality geographic registration of images during mosaicking. Applications requiring accurate reflectance data also require radiometric-calibration references so that reflectance values of image objects can be calculated. We have developed a method for automated geographic registration and radiometric correction with targets that are installed semi-permanently at distributed locations around fields. The targets are a combination of black (≍5% reflectance), dark gray (≍20% reflectance), and light gray (≍40% reflectance) sections that provide for a transformation of pixel-value to reflectance in the dynamic range of crop fields. The exact spectral reflectance of each target is known, having been measured with a spectrophotometer. At the time of installation, each target is measured for position with a real-time kinematic GPS receiver to give its precise latitude and longitude. Automated location of the reference targets in the images is required for precise, automated, geographic registration; and automated calculation of the digital-number to reflectance transformation is required for automated radiometric calibration. To validate the system for radiometric calibration, a calibrated UAV-based image mosaic of a field was compared to a calibrated single image from a manned aircraft. Reflectance values in selected zones of each image were strongly linearly related, and the average error of UAV-mosaic reflectances was 3.4% in the red band, 1.9% in the green band, and 1.5% in the blue band. Based on these results, the proposed physical system and automated software for calibrating UAV mosaics show excellent promise.

Analysis of Interval Changes on Mammograms for Computer Aided Diagnosis

DTIC Science & Technology

2000-05-01

tizer was calibrated so that the gray values were linearly and erage pixel values in the template and ROI, respectively. The inversely proportional to the...earlier for linearly and inversely proportional to the OD within the alignment of the breast regions, except that the regions to be range 0-4 OD...results versely proportional to the radial distance r from the nipple. in a decrease in the value of (to 20 mm. This decrease helps For the data set

The Kain-Fritsch Scheme: Science Updates & Revisiting Gray-Scale Issues from the NWP & Regional Climatae Perspectives

EPA Science Inventory

It’s just a matter of time before we see global climate models increasing their spatial resolution to that now typical of regional models. This encroachment brings in an urgent need for making regional NWP and climate models applicable at certain finer resolutions. One of the hin...

Automatic counting and classification of bacterial colonies using hyperspectral imaging

USDA-ARS?s Scientific Manuscript database

Detection and counting of bacterial colonies on agar plates is a routine microbiology practice to get a rough estimate of the number of viable cells in a sample. There have been a variety of different automatic colony counting systems and software algorithms mainly based on color or gray-scale pictu...

The genome of black cottonwood, Populus trichocarpa (Torr. & Gray)

Treesearch

G.A. Tuskan; S. DiFazio; S. Jansson; J. Bohlmann; I. Grigoriev; U. Hellsten; N. Putnam; S. Ralph; S. Rombauts; A. Salamov; J. Schein; L. Sterck; A. Aerts; R.R. Bhalerao; R.P. Bhalerao; D. Blaudez; W. Boerjan; A. Brun; A. Brunner; V. Busov; M. Campbell; J. Carlson; M. Chalot; J. Chapman; G.-L. Chen; D. Cooper; P.M. Coutinho; J. Couturier; S. Covert; Q. Cronk; R. Cunningham; J. Davis; S. Degroeve; A. Dejardin; C. dePamphilis; J. Detter; B. Dirks; U. Dubchak; S. Duplessis; J. Ehlting; B. Ellis; K. Gendler; D. Goodstein; M. Gribskov; J. Grimwood; A. Groover; L. Gunter; B. Hamberger; B. Heinze; Y. Helariutta; B. Henrissat; D. Holligan; R. Holt; W. Huang; N. Islam-Faridi; S. Jones; M. Jones-Rhoades; R. Jorgensen; C. Joshi; J. Kangasjarvi; J. Karlsson; C. Kelleher; R. Kirkpatrick; M. Kirst; A. Kohler; U. Kalluri; F. Larimer; J. Leebens-Mack; J.-C. Leple; P. Locascio; Y. Lou; S. Lucas; F. Martin; B. Montanini; C. Napoli; D.R. Nelson; C. Nelson; K. Nieminen; O. Nilsson; V. Pereda; G. Peter; R. Philippe; G. Pilate; A. Poliakov; J. Razumovskaya; P. Richardson; C. Rinaldi; K. Ritland; P. Rouze; D. Ryaboy; J. Schumtz; J. Schrader; B. Segerman; H. Shin; A. Siddiqui; F. Sterky; A. Terry; C.-J. Tsai; E. Uberbacher; P. Unneberg; J. Vahala; K. Wall; S. Wessler; G. Yang; T. Yin; C. Douglas; M. Marra; G. Sandberg; Y. Van de Peer; D. Rokhsar

2006-01-01

We report the draft genome of the black cottonwood tree, Populus trichocarpa. Integration of shotgun sequence assembly with genetic mapping enabled chromosome-scale reconstruction of the genome. More than 45,000 putative protein-coding genes were identified. Analysis of the assembled genome revealed a whole-genome duplication event; about 8000 pairs...

Vatican Library Automates for the 21st Century.

ERIC Educational Resources Information Center

Carter, Thomas L.

1994-01-01

Because of space and staff constraints, the Vatican Library can issue only 2,000 reader cards a year. Describes IBM's Vatican Library Project: converting the library catalog records (prior to 1985) into machine readable form and digitally scanning 20,000 manuscript pages, print pages, and art works in gray scale and color, creating a database…

Adaptive Encoding for Numerical Data Compression.

ERIC Educational Resources Information Center

Yokoo, Hidetoshi

1994-01-01

Discusses the adaptive compression of computer files of numerical data whose statistical properties are not given in advance. A new lossless coding method for this purpose, which utilizes Adelson-Velskii and Landis (AVL) trees, is proposed. The method is effective to any word length. Its application to the lossless compression of gray-scale images…

Investigation of Large Scale Cortical Models on Clustered Multi-Core Processors

DTIC Science & Technology

2013-02-01

with the bias node ( gray ) denoted as ww and the weights associated with the remaining first layer nodes (black) denoted as W. In forming the overall...Implementation of RBF network on GPU Platform 3.5.1 The Cholesky decomposition algorithm We need to invert the matrix multiplication GTG to

A Genetic Analysis of Brain Volumes and IQ in Children

ERIC Educational Resources Information Center

van Leeuwen, Marieke; Peper, Jiska S.; van den Berg, Stephanie M.; Brouwer, Rachel M.; Hulshoff Pol, Hilleke E.; Kahn, Rene S.; Boomsma, Dorret I.

2009-01-01

In a population-based sample of 112 nine-year old twin pairs, we investigated the association among total brain volume, gray matter and white matter volume, intelligence as assessed by the Raven IQ test, verbal comprehension, perceptual organization and perceptual speed as assessed by the Wechsler Intelligence Scale for Children-III. Phenotypic…

Quantitative analysis of brain magnetic resonance imaging for hepatic encephalopathy

NASA Astrophysics Data System (ADS)

Syh, Hon-Wei; Chu, Wei-Kom; Ong, Chin-Sing

1992-06-01

High intensity lesions around ventricles have recently been observed in T1-weighted brain magnetic resonance images for patients suffering hepatic encephalopathy. The exact etiology that causes magnetic resonance imaging (MRI) gray scale changes has not been totally understood. The objective of our study was to investigate, through quantitative means, (1) the amount of changes to brain white matter due to the disease process, and (2) the extent and distribution of these high intensity lesions, since it is believed that the abnormality may not be entirely limited to the white matter only. Eleven patients with proven haptic encephalopathy and three normal persons without any evidence of liver abnormality constituted our current data base. Trans-axial, sagittal, and coronal brain MRI were obtained on a 1.5 Tesla scanner. All processing was carried out on a microcomputer-based image analysis system in an off-line manner. Histograms were decomposed into regular brain tissues and lesions. Gray scale ranges coded as lesion were then brought back to original images to identify distribution of abnormality. Our results indicated the disease process involved pallidus, mesencephalon, and subthalamic regions.

Automatic crack detection and classification method for subway tunnel safety monitoring.

PubMed

Zhang, Wenyu; Zhang, Zhenjiang; Qi, Dapeng; Liu, Yun

2014-10-16

Cracks are an important indicator reflecting the safety status of infrastructures. This paper presents an automatic crack detection and classification methodology for subway tunnel safety monitoring. With the application of high-speed complementary metal-oxide-semiconductor (CMOS) industrial cameras, the tunnel surface can be captured and stored in digital images. In a next step, the local dark regions with potential crack defects are segmented from the original gray-scale images by utilizing morphological image processing techniques and thresholding operations. In the feature extraction process, we present a distance histogram based shape descriptor that effectively describes the spatial shape difference between cracks and other irrelevant objects. Along with other features, the classification results successfully remove over 90% misidentified objects. Also, compared with the original gray-scale images, over 90% of the crack length is preserved in the last output binary images. The proposed approach was tested on the safety monitoring for Beijing Subway Line 1. The experimental results revealed the rules of parameter settings and also proved that the proposed approach is effective and efficient for automatic crack detection and classification.

The crack detection algorithm of pavement image based on edge information

NASA Astrophysics Data System (ADS)

Yang, Chunde; Geng, Mingyue

2018-05-01

As the images of pavement cracks are affected by a large amount of complicated noises, such as uneven illumination and water stains, the detected cracks are discontinuous and the main body information at the edge of the cracks is easily lost. In order to solve the problem, a crack detection algorithm in pavement image based on edge information is proposed. Firstly, the image is pre-processed by the nonlinear gray-scale transform function and reconstruction filter to enhance the linear characteristic of the crack. At the same time, an adaptive thresholding method is designed to coarsely extract the cracks edge according to the gray-scale gradient feature and obtain the crack gradient information map. Secondly, the candidate edge points are obtained according to the gradient information, and the edge is detected based on the single pixel percolation processing, which is improved by using the local difference between pixels in the fixed region. Finally, complete crack is obtained by filling the crack edge. Experimental results show that the proposed method can accurately detect pavement cracks and preserve edge information.

The correlation between emotional intelligence and gray matter volume in university students.

PubMed

Tan, Yafei; Zhang, Qinglin; Li, Wenfu; Wei, Dongtao; Qiao, Lei; Qiu, Jiang; Hitchman, Glenn; Liu, Yijun

2014-11-01

A number of recent studies have investigated the neurological substrates of emotional intelligence (EI), but none of them have considered the neural correlates of EI that are measured using the Schutte Self-Report Emotional Intelligence Scale (SSREIS). This scale was developed based on the EI model of Salovey and Mayer (1990). In the present study, SSREIS was adopted to estimate EI. Meanwhile, magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) were used to evaluate the gray matter volume (GMV) of 328 university students. Results found positive correlations between Monitor of Emotions and VBM measurements in the insula and orbitofrontal cortex. In addition, Utilization of Emotions was positively correlated with the GMV in the parahippocampal gyrus, but was negatively correlated with the VBM measurements in the fusiform gyrus and middle temporal gyrus. Furthermore, Social Ability had volume correlates in the vermis. These findings indicate that the neural correlates of the EI model, which primarily focuses on the abilities of individuals to appraise and express emotions, can also regulate and utilize emotions to solve problems. Copyright © 2014 Elsevier Inc. All rights reserved.

Brain gray matter alterations in Chinese patients with chronic knee osteoarthritis pain based on voxel-based morphometry

PubMed Central

Liao, Xia; Mao, Cuiping; Wang, Yuan; Zhang, Qingfeng; Cao, Dongyuan; Seminowicz, David A.; Zhang, Ming; Yang, Xiaoli

2018-01-01

Abstract Altered cerebral gray matter volume (GMV) is commonly found in patients with chronic pain. Chronic pain is the prominent characteristic of knee osteoarthritis (KOA), yet little is known about its morphological changes in the brain. Here an MRI study was performed to examine the structural brain abnormalities in 30 KOA patients with knee pain and age-matched healthy subjects. We detected that the patients exhibited significant almost 2-fold age-related decreases of GMV compared to healthy controls. Moreover, KOA patients also had significant loss of regional GMV including in the bilateral orbital frontal cortex (OFC), the right lateral prefrontal cortex (lPFC), and precentral and postcentral cortices. In addition, a high proportion of KOA patients exerted abnormal scores of Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Scale (HAMA), Mini Mental State examination (MMSE), and Montreal Cognitive Assessment (MoCA) compare to controls. Our results imply that chronic pain conditions which preferentially involve PFC might consider as a “cognitive state.” And emotion and cognitive function about chronic pain should be highly regarded. PMID:29561420

Automatic Crack Detection and Classification Method for Subway Tunnel Safety Monitoring

PubMed Central

Zhang, Wenyu; Zhang, Zhenjiang; Qi, Dapeng; Liu, Yun

2014-01-01

Cracks are an important indicator reflecting the safety status of infrastructures. This paper presents an automatic crack detection and classification methodology for subway tunnel safety monitoring. With the application of high-speed complementary metal-oxide-semiconductor (CMOS) industrial cameras, the tunnel surface can be captured and stored in digital images. In a next step, the local dark regions with potential crack defects are segmented from the original gray-scale images by utilizing morphological image processing techniques and thresholding operations. In the feature extraction process, we present a distance histogram based shape descriptor that effectively describes the spatial shape difference between cracks and other irrelevant objects. Along with other features, the classification results successfully remove over 90% misidentified objects. Also, compared with the original gray-scale images, over 90% of the crack length is preserved in the last output binary images. The proposed approach was tested on the safety monitoring for Beijing Subway Line 1. The experimental results revealed the rules of parameter settings and also proved that the proposed approach is effective and efficient for automatic crack detection and classification. PMID:25325337

Occulting focal plane masks for Terrestrial Planet Finder Coronagraph: design, fabrication, simulations and test results

NASA Technical Reports Server (NTRS)

Balasubramanian, Kunjithapatham; Hoppe, Daniel J.; Halverson, Peter G.; Wilson, Daniel W.; Echternach, Pierre M.; Shi, Fang; Lowman, Andrew E.; Niessner, Albert F.; Trauger, John T.; Shaklan, Stuart B.

2005-01-01

Occulting focal plane masks for the Terrestrial Planet Finder Coronagraph (TPF-C) could be designed with continuous gray scale profile of the occulting pattern such as 1-sinc2 on a suitable material or with micron-scale binary transparent and opaque structures of metallic pattern on glass. We have designed, fabricated and tested both kinds of masks. The fundamental characteristics of such masks and initial test results from the High Contrast Imaging Test bed (HCIT) at JPL are presented.

Significance of resistive index in color Doppler ultrasonogram: differentiation between benign and malignant breast masses.

PubMed

Choi, H Y; Kim, H Y; Baek, S Y; Kang, B C; Lee, S W

1999-01-01

The objective of this article is to evaluate the significance of resistive index in differentiation between benign and malignant breast lesions on duplex ultrasonographic examination. Resistive indices obtained in 106 breast lesions of 104 patients were included. Sixty-four were benign (mean age: 32.4 +/- 11.1 years), and 42 were malignant lesions (mean age: 47.8 +/- 11.4 years). The resistive index was classified as follows: below 0.49, from 0.5 to 0.59, 0.6 to 0.69, 0.7 to 0.79, and above 0.8. We analyzed and defined the optimal threshold value of RI between benign and malignant lesions. The mean values of the RI of benign and malignant lesions were 0.62 +/- 0.095 (range 0.44-0.86) and 0.74 +/- 0.097 (range, 0.50-0.92), respectively. The resistive index exceeded 0.7 in 80% of malignant lesions. The difference of the RI between malignant and benign lesions was statistically significant when the threshold value was 0.7 (P < 0.001). A resistive index over 0.7 may suggest malignant lesions. Due to the considerable overlap of the range of the RI, it may not be diagnostic in any single patient; however, it may be helpful in conjunct with gray-scale image.

Multi-image encryption based on synchronization of chaotic lasers and iris authentication

NASA Astrophysics Data System (ADS)

Banerjee, Santo; Mukhopadhyay, Sumona; Rondoni, Lamberto

2012-07-01

A new technique of transmitting encrypted combinations of gray scaled and chromatic images using chaotic lasers derived from Maxwell-Bloch's equations has been proposed. This novel scheme utilizes the general method of solution of a set of linear equations to transmit similar sized heterogeneous images which are a combination of monochrome and chromatic images. The chaos encrypted gray scaled images are concatenated along the three color planes resulting in color images. These are then transmitted over a secure channel along with a cover image which is an iris scan. The entire cryptology is augmented with an iris-based authentication scheme. The secret messages are retrieved once the authentication is successful. The objective of our work is briefly outlined as (a) the biometric information is the iris which is encrypted before transmission, (b) the iris is used for personal identification and verifying for message integrity, (c) the information is transmitted securely which are colored images resulting from a combination of gray images, (d) each of the images transmitted are encrypted through chaos based cryptography, (e) these encrypted multiple images are then coupled with the iris through linear combination of images before being communicated over the network. The several layers of encryption together with the ergodicity and randomness of chaos render enough confusion and diffusion properties which guarantee a fool-proof approach in achieving secure communication as demonstrated by exhaustive statistical methods. The result is vital from the perspective of opening a fundamental new dimension in multiplexing and simultaneous transmission of several monochromatic and chromatic images along with biometry based authentication and cryptography.

Tissue-Selective Salvage of the White Matter by Successful Endovascular Stroke Therapy.

PubMed

Kleine, Justus F; Kaesmacher, Mirjam; Wiestler, Benedikt; Kaesmacher, Johannes

2017-10-01

White matter (WM) is less vulnerable to ischemia than gray matter. In ischemic stroke caused by acute large-vessel occlusion, successful recanalization might therefore sometimes selectively salvage the WM, leading to infarct patterns confined to gray matter. This study examines occurrence, determinants, and clinical significance of such effects. Three hundred twenty-two patients with acute middle cerebral artery occlusion subjected to mechanical thrombectomy were included. Infarct patterns were categorized into WM - (sparing the WM) and WM + (involving WM). National Institutes of Health Stroke Scale-based measures of neurological outcome, including National Institutes of Health Stroke Scale improvement or National Institutes of Health Stroke Scale worsening, good functional midterm outcome (day 90-modified Rankin Scale score of ≤2), the occurrence of malignant swelling, and in-hospital mortality were predefined outcome measures. WM - infarcts occurred in 118 of 322 patients and were associated with successful recanalization and better collateral grades ( P <0.05). Shorter symptom-onset to recanalization times were also associated with WM - infarcts in univariate analysis, but not when adjusted for collateral grades. WM - infarcts were independently associated with good neurological outcome (adjusted odds ratio, 3.003; 95% confidence interval, 1.186-7.607; P =0.020) and good functional midterm outcome (adjusted odds ratio, 8.618; 95% confidence interval, 2.409-30.828; P =0.001) after correcting for potential confounders, including final infarct volume. Only 2.6% of WM - patients, but 20.5% of WM + patients exhibited neurological worsening, and none versus 12.8% developed malignant swelling ( P <0.001), contributing to lower mortality in this group (2.5% versus 10.3%; P =0.014). WM infarction commonly commences later than gray matter infarction after acute middle cerebral artery occlusion. Successful recanalization can therefore salvage completely the WM at risk in many patients even several hours after symptom onset. Preservation of the WM is associated with better neurological recovery, prevention of malignant swelling, and reduced mortality. This has important implications for neuroprotective strategies, and perfusion imaging-based patient selection, and provides a rationale for treating selected patients in extended time windows. © 2017 American Heart Association, Inc.

Graying America Presents Golden Opportunities for Camp Directors.

ERIC Educational Resources Information Center

Cosky, Alicia C.

1989-01-01

Discusses quality-of-life issues for ever-increasing population of American elderly, emphasizing value of recreation. Offers organized camping as way of exposing older adults to enjoyable physical activities. Cites evidence supporting beneficial effects of regular exercise for elderly, beginning at any age. (TES)

Homogeneity of GAFCHROMIC EBT2 film among different lot numbers

PubMed Central

Takahashi, Yutaka; Tanaka, Atsushi; Hirayama, Takamitsu; Yamaguchi, Tsuyoshi; Katou, Hiroaki; Takahara, Keiko; Okamoto, Yoshiaki; Teshima, Teruki

2012-01-01

EBT2 film is widely used for quality assurance in radiation therapy. The purpose of this study was to investigate the homogeneity of EBT2 film among various lots, and the dose dependence of heterogeneity. EBT2 film was positioned in the center of a flatbed scanner and scanned in transmission mode at 75 dpi. Homogeneity was investigated by evaluating gray value and net optical density (netOD) with the red color channel. The dose dependence of heterogeneity in a single sheet from five lots was investigated at 0.5, 2, and 3 Gy. Maximum coefficient of variation as evaluated by netOD in a single film was 3.0% in one lot, but no higher than 0.5% in other lots. Dose dependence of heterogeneity was observed on evaluation by gray value but not on evaluation by netOD. These results suggest that EBT2 should be examined in each lot number before clinical use, and that the dose calibration curve should be constructed using netOD. PACS number: 87 PMID:22766947

Growth response of Acacia koa trees to thinning, grass control, and phosphorus fertilization in a secondary forest in Hawai‘i

Treesearch

Paul G. Scowcroft; J.B. Friday; Travis Idol; Nicklos Dudley; Janis Haraguchi; Dean Meason

2007-01-01

Koa (Acacia koa A. Gray) is an endemic Hawaiian hardwood tree of high ecological, cultural and economic value. Despite its multiple values, research on the silviculture of koa has been minimal until recently because the preferred land-use was pasture for livestock, and logging was done mainly to facilitate and reduce the costs of conversion. This...

Stable Isotope (δ13C, δ15N, δ34S) Analysis and Satellite Telemetry Depict the Complexity of Gray Wolf (Canis lupus) Diets in Southwest Alaska

NASA Astrophysics Data System (ADS)

Stanek, A.; Watts, D. E.; Cohn, B. R.; Spencer, P.; Mangipane, B.; Welker, J. M.

2010-12-01

Throughout Alaska, gray wolves (Canis lupus) are a top predator of large ungulates. While they primarily rely on ungulates such as moose (Alces alces) and caribou (Rangifer tarandus) as food, they are opportunistic and use alternative resources. The variation and supplemental protein sources in wolf diet has not been studied extensively on live animals currently using the landscape. With large seasonal influxes of Pacific salmon (Oncorhynchus sp.) into Alaska, terrestrial carnivore use of marine species is of particular interest. Using stable isotope (δ13C, δ15N, δ34S) analysis of wolf guard hair and blood, this study aims to determine the proportion of marine derived nutrients (MDN) in the diet of wolf packs within and surrounding Lake Clark National Park and Preserve and Alaska Peninsula and Becharof National Wildlife Refuges in Southwest Alaska. Satellite telemetry from the animals sampled facilitates quantification of landscape use patterns in correspondence with isotopic traits. Wolf pack territories within and surrounding the Lake Clark region appear to vary in spatial extent and in availability of MDN, such as salmon. Initial analysis shows that two packs with smaller home ranges, centrally located around areas with greater salmon availability, have enriched δ15N values compared to packs that have larger home ranges not centralized around salmon spawning waters. This pattern of isotopic enrichment is found in red blood cells, blood serum and hair, representing diets over different time scales. The enrichment in both blood and hair indicates a sustained use of MDN over the previous six to nine months. In the Lake Clark region, simple mixing model estimates suggest that up to 30% of wolf pack diets may be from marine sources. In contrast, packs with larger home ranges and less access to salmon have stable isotope values representative of a terrestrial diet.

An adaptive enhancement algorithm for infrared video based on modified k-means clustering

NASA Astrophysics Data System (ADS)

Zhang, Linze; Wang, Jingqi; Wu, Wen

2016-09-01

In this paper, we have proposed a video enhancement algorithm to improve the output video of the infrared camera. Sometimes the video obtained by infrared camera is very dark since there is no clear target. In this case, infrared video should be divided into frame images by frame extraction, in order to carry out the image enhancement. For the first frame image, which can be divided into k sub images by using K-means clustering according to the gray interval it occupies before k sub images' histogram equalization according to the amount of information per sub image, we used a method to solve a problem that final cluster centers close to each other in some cases; and for the other frame images, their initial cluster centers can be determined by the final clustering centers of the previous ones, and the histogram equalization of each sub image will be carried out after image segmentation based on K-means clustering. The histogram equalization can make the gray value of the image to the whole gray level, and the gray level of each sub image is determined by the ratio of pixels to a frame image. Experimental results show that this algorithm can improve the contrast of infrared video where night target is not obvious which lead to a dim scene, and reduce the negative effect given by the overexposed pixels adaptively in a certain range.

Neurofilament light protein in blood predicts regional atrophy in Huntington disease

PubMed Central

Johnson, Eileanoir B.; Byrne, Lauren M.; Gregory, Sarah; Rodrigues, Filipe B.; Blennow, Kaj; Durr, Alexandra; Leavitt, Blair R.; Roos, Raymund A.; Zetterberg, Henrik; Tabrizi, Sarah J.; Scahill, Rachael I.

2018-01-01

Objective Neurofilament light (NfL) protein in blood plasma has been proposed as a prognostic biomarker of neurodegeneration in a number of conditions, including Huntington disease (HD). This study investigates the regional distribution of NfL-associated neural pathology in HD gene expansion carriers. Methods We examined associations between NfL measured in plasma and regionally specific atrophy in cross-sectional (n = 198) and longitudinal (n = 177) data in HD gene expansion carriers from the international multisite TRACK-HD study. Using voxel-based morphometry, we measured associations between baseline NfL levels and both baseline gray matter and white matter volume; and longitudinal change in gray matter and white matter over the subsequent 3 years in HD gene expansion carriers. Results After controlling for demographics, associations between increased NfL levels and reduced brain volume were seen in cortical and subcortical gray matter and within the white matter. After also controlling for known predictors of disease progression (age and CAG repeat length), associations were limited to the caudate and putamen. Longitudinally, NfL predicted subsequent occipital gray matter atrophy and widespread white matter reduction, both before and after correction for other predictors of disease progression. Conclusions These findings highlight the value of NfL as a dynamic marker of brain atrophy and, more generally, provide further evidence of the strong association between plasma NfL level, a candidate blood biomarker, and pathologic neuronal change. PMID:29367444

Negative-assortative mating for color in wolves.

PubMed

Hedrick, Philip W; Smith, Douglas W; Stahler, Daniel R

2016-04-01

There is strong negative-assortative mating for gray and black pelage color in the iconic wolves in Yellowstone National Park. This is the first documented case of significant negative-assortative mating in mammals and one of only a very few cases in vertebrates. Of 261 matings documented from 1995 to 2015, 63.6% were between gray and black wolves and the correlation between mates for color was -0.266. There was a similar excess of matings of both gray males × black females and black males × gray females. Using the observed frequency of negative-assortative mating in a model with both random and negative-assortative mating, the estimated proportion of negative-assortative mating was 0.430. The estimated frequency of black wolves in the population from 1996 to 2014 was 0.452 and these frequencies appear stable over this 19-year period. Using the estimated level of negative-assortative mating, the predicted equilibrium frequency of the dominant allele was 0.278, very close to the mean value of 0.253 observed. In addition, the patterns of genotype frequencies, that is, the observed proportion of black homozygotes and the observed excess of black heterozygotes, are consistent with negative-assortative mating. Importantly these results demonstrate that negative-assortative mating could be entirely responsible for the maintenance of this well-known color polymorphism. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Seroprevalence of Neospora caninum in gray wolves in Scandinavia.

PubMed

Björkman, C; Jakubek, E-B; Arnemo, J M; Malmsten, J

2010-10-11

Transmission of the protozoan parasite Neospora caninum between wild and domestic animals has gained some interest during recent years. Because of the close relationship between gray wolf (Canis lupus) and dog it has been suggested that gray wolf is a definitive host for the parasite. The aim of this study was to estimate the seroprevalence of N. caninum in Scandinavian gray wolves and to investigate any geographical patterns of the infection. The investigation was based on blood samples collected from 109 wolves between 1998 and 2009 within the Scandinavian wolf project Skandulv. They were analysed by N. caninum iscom ELISA and those with absorbance values exceeding 0.20 were also analysed by immunoblotting. Samples that were positive in both tests were deemed positive. Four (3.7%) wolves were positive at the first sampling. They were all sampled 2005 at different locations, and were both females and males. From one male wolf three samples were collected over a 7-year period. No antibodies were detected at the first sampling in 1998 when he was approximately 8 months old but when he was sampled again 5 and 7 years later the ELISA and immunoblotting were positive. The results indicate that N. caninum infection is present in Scandinavian wolves. It is unclear how the wolves acquired the infection. Copyright 2010 Elsevier B.V. All rights reserved.

Synergizing green and gray infrastructures to increase water supply resilience in the Brazos River basin in Texas

NASA Astrophysics Data System (ADS)

Gao, H.; Yamazaki, D.; Finley, T.; Bohn, T. J.; Low, G.; Sabo, J. L.

2017-12-01

Water infrastructure lies at the heart of the challenges and opportunities of Integrated Water Resource Management (IWRM). Green infrastructure (e.g., wetlands restoration) presents an alternative to its hard-path counterpart - gray infrastructure, which often has external, economic and unmeasured ecological costs. But the science framework to prioritize green infrastructure buildout is nascent. In this study, we addressed this gap in Brazos River basin in Texas, in the context of corporate decisions to secure water supplies for various water stewardship objectives. We developed a physically-based tool to quantify the potential for wetland restoration to restore desired flows (hydrology), and a financial framework for comparing its cost-benefit with heightening an existing dam (conservation finance). Our framework has three components. First, we harnessed a topographic index (HAND) to identify the potential wetlands sites. Second, we coupled a land surface model (VIC) with a hydrodynamic model (CaMa-Flood) to investigate the effects of wetland size, location, and vegetation on hydrology. Finally, we estimated the net present value, indirect rate of return and payback period for green (wetlands) vs. gray (reservoir expansion) infrastructure. We found wetlands have more substantial impact on peak flow than baseflow. Interestingly, wetlands can improve baseflow reliability but not directly except with the largest (>400 km2) projects. Peak flow reduction volumes of wetlands if used as credits towards reservoir flood-control storage provide adequate conservation storage to deliver guaranteed reliability of baseflow. Hence, the synergy of existing dams with newly created wetlands offers a promising natural solution to increase water supply resilience, while green projects also generate revenue compared to their gray counterparts. This study demonstrates the possibility of using innovative engineering design to synergize green and gray infrastructures to convert water conflict to opportunities.

Measuring surface topography with scanning electron microscopy. I. EZEImage: a program to obtain 3D surface data.

PubMed

Ponz, Ezequiel; Ladaga, Juan Luis; Bonetto, Rita Dominga

2006-04-01

Scanning electron microscopy (SEM) is widely used in the science of materials and different parameters were developed to characterize the surface roughness. In a previous work, we studied the surface topography with fractal dimension at low scale and two parameters at high scale by using the variogram, that is, variance vs. step log-log graph, of a SEM image. Those studies were carried out with the FERImage program, previously developed by us. To verify the previously accepted hypothesis by working with only an image, it is indispensable to have reliable three-dimensional (3D) surface data. In this work, a new program (EZEImage) to characterize 3D surface topography in SEM has been developed. It uses fast cross correlation and dynamic programming to obtain reliable dense height maps in a few seconds which can be displayed as an image where each gray level represents a height value. This image can be used for the FERImage program or any other software to obtain surface topography characteristics. EZEImage also generates anaglyph images as well as characterizes 3D surface topography by means of a parameter set to describe amplitude properties and three functional indices for characterizing bearing and fluid properties.

Is articular pain in rheumatoid arthritis correlated with ultrasound power Doppler findings?

PubMed

Pereira, Daniele Freitas; Gutierrez, Marwin; de Buosi, Ana Leticia Pirozzi; Ferreira, Fernando Bernardes Maia Diniz; Draghessi, Antonella; Grassi, Walter; Natour, Jamil; Furtado, Rita Nely Vilar

2015-11-01

The study is addressed to determine if there is a correlation between intra-articular power Doppler (PD) and pain symptoms in patients with rheumatoid arthritis (RA). A cross-sectional study of patients with established RA was rolled out. Seventy-two patients with chronic swelling at metacarpophalangeal (MCP) joints were consecutively enrolled in the study and divided into two groups (painful and painless). In the painful group, the inclusion criteria were pain in the visual analog scale (VAS), from 0 to 10 cm, of at least 4 cm and 0 in the painless group. All two to five MCP joints, bilaterally, were scanned by ultrasound (US) searching for intra-articular PD presence. Any value of p < 0.05 was considered significant. Patients in the painful group had longer morning stiffness, worse 28-joint disease activity score (DAS 28), and health assessment questionnaire (HAQ) indexes. There were no association between pain and gray scale (GS) synovitis, odds ratio (OR) = 0.9 (0.6-1.2), p = 0.485; and pain and intra-articular PD, OR = 0.8 (0.6-1.2), p = 0.244. Intra-articular PD was not correlated with pain symptom in this study.

Education, occupation, leisure activities, and brain reserve: a population-based study.

PubMed

Foubert-Samier, Alexandra; Catheline, Gwenaelle; Amieva, Hélène; Dilharreguy, Bixente; Helmer, Catherine; Allard, Michèle; Dartigues, Jean-François

2012-02-01

The influence of education, occupation, and leisure activities on the passive and active components of reserve capacity remains unclear. We used the voxel-based morphometry (VBM) technique in a population-based sample of 331 nondemented people in order to investigate the relationship between these factors and the cerebral volume (a marker of brain reserve). The results showed a positive and significant association between education, occupation, and leisure activities and the cognitive performances on Isaac's set test. Among these factors, only education was significantly associated with a cerebral volume including gray and white matter (p = 0.01). In voxel-based morphometry analyses, the difference in gray matter volume was located in the temporoparietal lobes and in the orbitofrontal lobes bilaterally (a p-value corrected <0.05 by false discovery rate [FDR]). Although smaller, the education-related difference in white matter volume appeared in areas connected to the education-related difference in gray matter volume. Education, occupation attainment, and leisure activities were found to contribute differently to reserve capacity. Education could play a role in the constitution of cerebral reserve capacity. Copyright © 2012 Elsevier Inc. All rights reserved.

Embedded 3D shape measurement system based on a novel spatio-temporal coding method

NASA Astrophysics Data System (ADS)

Xu, Bin; Tian, Jindong; Tian, Yong; Li, Dong

2016-11-01

Structured light measurement has been wildly used since 1970s in industrial component detection, reverse engineering, 3D molding, robot navigation, medical and many other fields. In order to satisfy the demand for high speed, high precision and high resolution 3-D measurement for embedded system, a new patterns combining binary and gray coding principle in space are designed and projected onto the object surface orderly. Each pixel corresponds to the designed sequence of gray values in time - domain, which is treated as a feature vector. The unique gray vector is then dimensionally reduced to a scalar which could be used as characteristic information for binocular matching. In this method, the number of projected structured light patterns is reduced, and the time-consuming phase unwrapping in traditional phase shift methods is avoided. This algorithm is eventually implemented on DM3730 embedded system for 3-D measuring, which consists of an ARM and a DSP core and has a strong capability of digital signal processing. Experimental results demonstrated the feasibility of the proposed method.

LSB-Based Steganography Using Reflected Gray Code

NASA Astrophysics Data System (ADS)

Chen, Chang-Chu; Chang, Chin-Chen

Steganography aims to hide secret data into an innocuous cover-medium for transmission and to make the attacker cannot recognize the presence of secret data easily. Even the stego-medium is captured by the eavesdropper, the slight distortion is hard to be detected. The LSB-based data hiding is one of the steganographic methods, used to embed the secret data into the least significant bits of the pixel values in a cover image. In this paper, we propose an LSB-based scheme using reflected-Gray code, which can be applied to determine the embedded bit from secret information. Following the transforming rule, the LSBs of stego-image are not always equal to the secret bits and the experiment shows that the differences are up to almost 50%. According to the mathematical deduction and experimental results, the proposed scheme has the same image quality and payload as the simple LSB substitution scheme. In fact, our proposed data hiding scheme in the case of G1 (one bit Gray code) system is equivalent to the simple LSB substitution scheme.

A Study for Texture Feature Extraction of High-Resolution Satellite Images Based on a Direction Measure and Gray Level Co-Occurrence Matrix Fusion Algorithm

PubMed Central

Zhang, Xin; Cui, Jintian; Wang, Weisheng; Lin, Chao

2017-01-01

To address the problem of image texture feature extraction, a direction measure statistic that is based on the directionality of image texture is constructed, and a new method of texture feature extraction, which is based on the direction measure and a gray level co-occurrence matrix (GLCM) fusion algorithm, is proposed in this paper. This method applies the GLCM to extract the texture feature value of an image and integrates the weight factor that is introduced by the direction measure to obtain the final texture feature of an image. A set of classification experiments for the high-resolution remote sensing images were performed by using support vector machine (SVM) classifier with the direction measure and gray level co-occurrence matrix fusion algorithm. Both qualitative and quantitative approaches were applied to assess the classification results. The experimental results demonstrated that texture feature extraction based on the fusion algorithm achieved a better image recognition, and the accuracy of classification based on this method has been significantly improved. PMID:28640181

BOWIEITE: A NEW RHODIUM-IRIDIUM-PLATINUM SULFIDE IN PLATINUM-ALLOY NUGGETS, GOODNEWS BAY, ALASKA.

USGS Publications Warehouse

Desborough, George A.; Criddle, Alan J.

1984-01-01

Bowieite (Rh,Ir,Pt)//2S//3, a new mineral species, is found in three nuggets of platinum from Goodnews Bay, Alaska. In linearly polarized reflected light, and compared to the host, higher reflecting white platinum-iridium alloy, bowieite is pale gray to pale gray-brown; neither bireflectance nor reflectance pleochroism is apparent. With polars crossed, its anisotropic rotation tints vary from gray to dark brown. Luminance values (relative to the CIE illuminant C) for R//1 and R//2, computed from full spectral data for the most bireflectant grain, are 45. 8% and 48. 2% in air, and 30. 5% and 33. 0% in oil, respectively. VHN//1//0//0 1288 (858 to 1635). Bowieite is orthorhombic, space group Pnca, with a 8. 454(7) -8. 473(8), b 5. 995(1)-6. 002(7), c 6. 143(1)-6. 121(8) A, Z equals 4. Some grains that are 2. 6 to 3. 8 atomic % metal-deficient occur as an optically coherent rim on bowieite; the rim and the bowieite grain are not optically continuous.

Integrated stratigraphy of a shallow marine Paleocene-Eocene boundary section, MCBR cores, Maryland (USA)

NASA Astrophysics Data System (ADS)

Self-Trail, J. M.; Robinson, M. M.; Edwards, L. E.; Powars, D. S.; Wandless, G. A.; Willard, D. A.

2013-12-01

An exceptional Paleocene-Eocene boundary section occurs in a cluster of six short (<15m) coreholes (MCBR 1 through 6) drilled near Mattawoman Creek in western Charles County, Maryland. The sediments consist of glauconite-rich sand of the upper Paleocene Aquia Formation and silty clay of the lower Eocene Marlboro Clay. Sediment samples were analyzed for carbon and oxygen isotopes, percent calcium carbonate, calcareous nannofossils, planktic and benthic foraminifera, dinoflagellates, pollen, and lithology. A well-defined carbon isotope excursion (CIE) documents a gradual negative shift in δ13C values that starts below the lithologic break between the Aquia Formation and the Marlboro Clay. A benthic foraminifer extinction event, reduction of calcareous nannofossil assemblages, and change in core color from gray to alternating gray and pink also occurs within the CIE transition. These alternating changes in color coincide with cyclic peaks in the carbon isotope and percent calcium carbonate curves, where gray color corresponds to a positive shift in carbon isotope values and to a corresponding increase in percent benthic and planktic foraminifera. The upper third of the Marlboro Clay is barren of all calcareous microfossil material, although the presence of foraminiferal molds and linings proves that deposition occurred in a marine environment. Co-occurrence of the dinoflagellates Apectodinium augustum and Phthanoperidinium crenulatum at the top of the Marlboro Clay suggests that the Marlboro Clay at Mattawoman Creek is truncated. This is corroborated by the absence in the Marlboro of specimens of the calcareous nannofossil Rhomboaster-Discoaster assemblage, which is restricted to early Eocene Zone NP9b. Based on planktic/benthic foraminifera ratios, deposition of sediments at Mattawoman Creek occurred predominantly in an inner neritic environment, at water depths between 25-50 m. Occasional deepening to approximately 75m (middle neritic environment) occurred in the early Eocene, as represented by the basal Marlboro Clay. The planktic/benthic ratio, however, could also be affected by surface productivity and/or river runoff. The gradual shift up-section in core color from gray to alternating gray and red, to dark red, coupled with dissolution of calcareous microfossil assemblages, is possibly secondary and may represent lysocline shoaling in a nearshore environment. This would suggest that lysocline shoaling continued after the CIE and well into the early Eocene.

Microstructure abnormalities in adolescents with internet addiction disorder.

PubMed

Yuan, Kai; Qin, Wei; Wang, Guihong; Zeng, Fang; Zhao, Liyan; Yang, Xuejuan; Liu, Peng; Liu, Jixin; Sun, Jinbo; von Deneen, Karen M; Gong, Qiyong; Liu, Yijun; Tian, Jie

2011-01-01

Recent studies suggest that internet addiction disorder (IAD) is associated with structural abnormalities in brain gray matter. However, few studies have investigated the effects of internet addiction on the microstructural integrity of major neuronal fiber pathways, and almost no studies have assessed the microstructural changes with the duration of internet addiction. We investigated the morphology of the brain in adolescents with IAD (N = 18) using an optimized voxel-based morphometry (VBM) technique, and studied the white matter fractional anisotropy (FA) changes using the diffusion tensor imaging (DTI) method, linking these brain structural measures to the duration of IAD. We provided evidences demonstrating the multiple structural changes of the brain in IAD subjects. VBM results indicated the decreased gray matter volume in the bilateral dorsolateral prefrontal cortex (DLPFC), the supplementary motor area (SMA), the orbitofrontal cortex (OFC), the cerebellum and the left rostral ACC (rACC). DTI analysis revealed the enhanced FA value of the left posterior limb of the internal capsule (PLIC) and reduced FA value in the white matter within the right parahippocampal gyrus (PHG). Gray matter volumes of the DLPFC, rACC, SMA, and white matter FA changes of the PLIC were significantly correlated with the duration of internet addiction in the adolescents with IAD. Our results suggested that long-term internet addiction would result in brain structural alterations, which probably contributed to chronic dysfunction in subjects with IAD. The current study may shed further light on the potential brain effects of IAD.

Perceived area and the luminosity threshold.

PubMed

Bonato, F; Gilchrist, A L

1999-07-01

Observers made forced-choice opaque/luminous responses to targets of varying luminance and varying size presented (1) on the wall of a laboratory, (2) as a disk within an annulus, and (3) embedded within a Mondrian array presented within a vision tunnel. Lightness matches were also made for nearby opaque surfaces. The results show that the threshold luminance value at which a target begins to appear self-luminous increases with its size, defined as perceived size, not retinal size. More generally, the larger the target, the more an increase in its luminance induces grayness/blackness into the surround and the less it induces luminosity into the target, and vice versa. Corresponding to this luminosity/grayness tradeoff, there appears to be an invariant: Across a wide variety of conditions, a target begins to appear luminous when its luminance is about 1.7 times that of a surface that would appear white in the same illumination. These results show that the luminosity threshold behaves like a surface lightness value--the maximum lightness value, in fact--and is subject to the same laws of anchoring (such as the area rule proposed by Li & Gilchrist, 1999) as surface lightness.

On the identification of Dragon Kings among extreme-valued outliers

NASA Astrophysics Data System (ADS)

Riva, M.; Neuman, S. P.; Guadagnini, A.

2013-07-01

Extreme values of earth, environmental, ecological, physical, biological, financial and other variables often form outliers to heavy tails of empirical frequency distributions. Quite commonly such tails are approximated by stretched exponential, log-normal or power functions. Recently there has been an interest in distinguishing between extreme-valued outliers that belong to the parent population of most data in a sample and those that do not. The first type, called Gray Swans by Nassim Nicholas Taleb (often confused in the literature with Taleb's totally unknowable Black Swans), is drawn from a known distribution of the tails which can thus be extrapolated beyond the range of sampled values. However, the magnitudes and/or space-time locations of unsampled Gray Swans cannot be foretold. The second type of extreme-valued outliers, termed Dragon Kings by Didier Sornette, may in his view be sometimes predicted based on how other data in the sample behave. This intriguing prospect has recently motivated some authors to propose statistical tests capable of identifying Dragon Kings in a given random sample. Here we apply three such tests to log air permeability data measured on the faces of a Berea sandstone block and to synthetic data generated in a manner statistically consistent with these measurements. We interpret the measurements to be, and generate synthetic data that are, samples from α-stable sub-Gaussian random fields subordinated to truncated fractional Gaussian noise (tfGn). All these data have frequency distributions characterized by power-law tails with extreme-valued outliers about the tail edges.

Biotechnology for improving hydroxy fatty acid production in lesquerella

USDA-ARS?s Scientific Manuscript database

P Lesquerella [Physaria fendleri (A. Gray)], formerly Lesquerella fendleri, (Brassicaceae), being developed as a new industrial oilseed crop in the southwestern region of the United States, is valued for its unusual hydroxy fatty acid (HFA) in seed. The majority of HFA in lesquerella is lesquerolic...

Effects of landscape-based green infrastructure on stormwater ...

EPA Pesticide Factsheets

The development of impervious surfaces in urban and suburban catchments affects their hydrological behavior by decreasing infiltration, increasing peak hydrograph response following rainfall events, and ultimately increasing the total volume of water and mass of pollutants reaching streams. These changes have deleterious effects on downstream surface waters. Consequently, strategies to mitigate these impacts are now components of contemporary urban development and stormwater management. This study evaluates the effectiveness of landscape green infrastructure (GI) in reducing stormwater runoff volumes and controlling peak flows in four subdivision-scale suburban catchments (1.88 – 12.97 acres) in Montgomery County, MD, USA. Stormwater flow rates during runoff events were measured in five minute intervals at each catchment outlet. One catchment was built with GI vegetated swales on all parcels with the goal of intercepting, conveying, and infiltrating stormwater before it enters the sewer network. The remaining catchments were constructed with traditional gray infrastructure and “end-of-pipe” best management practices (BMPs) that treat stormwater before entering streams. This study compared characteristics of rainfall-runoff events at the green and gray infrastructure sites to understand their effects on suburban hydrology. The landscape GI strategy generally reduced rainfall-runoff ratios compared to gray infrastructure because of increased infiltration, ul

Cyanobacteria/Foraminifera Association from Anoxic/Dysoxic Beds of the Agua Nueva Formation (Upper Cretaceous - Cenomanian/Turonian) at Xilitla, San Luis Potosi, Central Mexico

NASA Astrophysics Data System (ADS)

Blanco-Piñón, A.; Maurrasse, F. J.; Rojas-León, A.; Duque-Botero, F.

2008-05-01

The Agua Nueva Formation in the vicinity of Xilitla, State of San Luis Potosí, Central Mexico, consists of interbedded brown shale (Grayish orange 10YR 7/4 to Moderate yellowish brown 10YR 5/4) and dark-gray fossiliferous limestone (Bluish gray 5B 6/1 to Dark bluish gray 5B 4/1), varying between 10 and 20 cm in thickness. The sequence also includes 2 to 4 cm- thick intermittent bentonite layers (Moderate greenish yellow 10Y 7/4, to dark greenish yellow 10Y 6/6 and Light olive 10Y 5/4). At the field scale, shaly intervals show no apparent internal structures, whereas most limestone beds show primary lamination at the millimeter scale (1-2 mm), and intermittent layers of black chert of about 5 cm thick. Pyrite is present as disseminated crystals and as 2 cm-thick layers. Bioturbation or macrobenthic organisms other than inoceramids do not occur in the Agua Nueva Formation at Xilitla. Unusual macrofossils are present only in limestone strata, and consist of well- preserved diverse genera of fishes such as sharks, Ptychodus sp. and teleosteans, Rhynchodercetis sp., Tselfatia sp., Goulmimichthys sp., and scales of Ichtyodectiformes, as well as ammonites and inoceramids (Blanco et al., 2006). The presence of Inoceramus (Mytyloides) labiatus (Maldonado-Koederll, 1956) indicates an Early Turonian age for the sequence. Total carbonate content (CaCO3 = TIC) varies between 62 and 94% in the Limestone beds, which yield Total Organic Carbon (TOC) from 0.4% to 2.5%; the shale intervals contain TIC values consistently lower than 33% and TOC lower than 0.8% Microscopically the limestone beds vary from mudstone to packstone composed essentially of coccoid cyanobacteria similar to coeval deposits in northeastern Mexico, Coahuila State, at Parras de La Fuente (Duque- Botero 2006). Similarly, the microspheroids are spherical to sub-spherical, and occur as isolated elements or aggregates forming series of chains of parallel-packed light lamina 1-2 mm thick. Filamentous cyanobacteria (> 1 mm in length) are also present oriented parallel to stratification. In addition to filamentous and coccoid cyanobacteria, the limestone beds contain rare benthic foraminifera, common planktic foraminifera, heterohelicids, Rotalipora spp., Rotalipora cf cushmani, Whiteinella spp, W. praehelvetica, which indicate a time interval from the latest Cenomanian to the earliest Turonian. Lithological, paleontological and microfacies data thus indicate that the sediments accumulated in open-marine to semi-restricted platform environments, under low-energy conditions. Primary lamination, pyrite and excellent degree of preservation of fishes, suggest that low oxygen concentration lead to the formation of anoxic/dysoxic conditions during the accumulation of these exceptional deposits, which are coeval with the worldwide development of OAE-2. Planktonic foraminifera and fishes indicate oxygenated conditions in the photic zone, but dysoxic/anoxic conditions near the bottom, which is consistent with the presence of inoceramids and the absence of bioturbation in the sediment.

Interface control document between the NASA Goddard Space Flight Center (GSFC) and Department of Interior EROS Data Center (EDC) for LANDSAT-D. Thematic mapper high resolution 241 mm film

NASA Technical Reports Server (NTRS)

1982-01-01

The 241 mm photographic product produced by the Goddard Space Flight Center Data Management System for LANDSAT-D is described. Film type and format, image dimensions, frame ID, gray scale, resolution patterns, registration marks, etc. are addressed.

A modular approach to detection and identification of defects in rough lumber

Treesearch

Sang Mook Lee; A. Lynn Abbott; Daniel L. Schmoldt

2001-01-01

This paper describes a prototype scanning system that can automatically identify several important defects on rough hardwood lumber. The scanning system utilizes 3 laser sources and an embedded-processor camera to capture and analyze profile and gray-scale images. The modular approach combines the detection of wane (the curved sides of a board, possibly containing...

Reconnaissance mapping from aerial photographs

NASA Technical Reports Server (NTRS)

Weeden, H. A.; Bolling, N. B. (Principal Investigator)

1975-01-01

The author has identified the following significant results. Engineering soil and geology maps were successfully made from Pennsylvania aerial photographs taken at scales from 1:4,800 to 1:60,000. The procedure involved a detailed study of a stereoscopic model while evaluating landform, drainage, erosion, color or gray tones, tone and texture patterns, vegetation, and cultural or land use patterns.

Registration verification of SEA/AR fields. [Oregon, Texas, Montana, Nebraska, Washington, Colorado, Kansas, Oklahoma, and North Dakota

NASA Technical Reports Server (NTRS)

Austin, W. W.; Lautenschlager, L. (Principal Investigator)

1981-01-01

A method of field registration verification for 20 SEA/AR sites for the 1979 crop year is evaluated. Field delineations for the sites were entered into the data base, and their registration verified using single channel gray scale computer printout maps of LANDSAT data taken over the site.

The fate of a gray soliton in a quenched Bose-Einstein condensate

NASA Astrophysics Data System (ADS)

Gamayun, Oleksandr; Bezvershenko, Yulia; Cheianov, Vadim

2015-03-01

We investigate the destiny of a gray soliton in a repulsive one-dimensional Bose-Einstein condensate undergoing a sudden quench of the non-linearity parameter. The outcome of the quench is found to depend dramatically on the ratio η of the final and initial values of the speed of sound. For integer η the soliton splits into exactly 2 η - 1 solitons. For non-integer η the soliton decays into multiple solitons and Bogoliubov modes. The case of integer η is analyzed in detail. The parameters of solitons in the out-state are found explicitly. Our approach exploits the inverse scattering method and can be easily used for the similar quenches in any classical integrable system.

An improved gray lattice Boltzmann model for simulating fluid flow in multi-scale porous media

NASA Astrophysics Data System (ADS)

Zhu, Jiujiang; Ma, Jingsheng

2013-06-01

A lattice Boltzmann (LB) model is proposed for simulating fluid flow in porous media by allowing the aggregates of finer-scale pores and solids to be treated as 'equivalent media'. This model employs a partially bouncing-back scheme to mimic the resistance of each aggregate, represented as a gray node in the model, to the fluid flow. Like several other lattice Boltzmann models that take the same approach, which are collectively referred to as gray lattice Boltzmann (GLB) models in this paper, it introduces an extra model parameter, ns, which represents a volume fraction of fluid particles to be bounced back by the solid phase rather than the volume fraction of the solid phase at each gray node. The proposed model is shown to conserve the mass even for heterogeneous media, while this model and that model of Walsh et al. (2009) [1], referred to the WBS model thereafter, are shown analytically to recover Darcy-Brinkman's equations for homogenous and isotropic porous media where the effective viscosity and the permeability are related to ns and the relaxation parameter of LB model. The key differences between these two models along with others are analyzed while their implications are highlighted. An attempt is made to rectify the misconception about the model parameter ns being the volume fraction of the solid phase. Both models are then numerically verified against the analytical solutions for a set of homogenous porous models and compared each other for another two sets of heterogeneous porous models of practical importance. It is shown that the proposed model allows true no-slip boundary conditions to be incorporated with a significant effect on reducing errors that would otherwise heavily skew flow fields near solid walls. The proposed model is shown to be numerically more stable than the WBS model at solid walls and interfaces between two porous media. The causes to the instability in the latter case are examined. The link between these two GLB models and a generalized Navier-Stokes model [2] for heterogeneous but isotropic porous media are explored qualitatively. A procedure for estimating model parameter ns is proposed.

Ultrasonographic evaluation of equine tendons: a quantitative in vitro study of the effects of amplifier gain level, transducer-tilt, and transducer-displacement.

PubMed

van Schie, J T; Bakker, E M; van Weeren, P R

1999-01-01

The objective of the in vitro experiments described in this paper was to quantify the effects of some instrumental variables on the quantitative evaluation, by means of first-order gray-level statistics, of ultrasonographic images of equine tendons. The experiments were done on three isolated equine superficial digital flexor tendons that were mounted in a frame and submerged in a waterbath. Sections with either normal tendon tissue, an acute lesion, or a chronic scar, were selected. In these sections, the following experiments were done: 1) a gradual increase of total amplifier gain output subdivided in 12 equal steps; 2) a transducer tilt plus or minus 3 degrees from perpendicular, with steps of 1 degree; and 3) a transducer displacement along, and perpendicular to, the tendon long axis, with 16 steps of 0.25 mm each. Transverse ultrasonographic images were collected, and in the regions of interest (ROI) first-order gray-level statistics were calculated to quantify the effects of each experiment. Some important observations were: 1) the total amplifier gain output has a substantial influence on the ultrasonographic image; for example, in the case of an acute lesion, a low gain setting results in an almost completely black image; whereas, with higher gain settings, a marked "filling in" effect on the lesion can be observed; 2) the relative effects of the tilting of the transducer are substantial in normal tendon tissue (18%) and chronic scar (12%); whereas, in the event of an acute lesion, the effects on the mean gray level are dramatic (40%); and 3) the relative effects of displacement of the transducer are small in normal tendon tissue, but on the other hand, the mean gray-level changes 7% in chronic scar, and even 20% in an acute lesion. In general, slight variations in scanner settings and transducer handling can have considerable effects on the gray levels of the ultrasonographic image. Furthermore, there is a strong indication that this quantitative method, as far as based exclusively on the first-order gray-level statistics, may be not discriminative enough to accurately assess the integrity of the tendon. Therefore, the value of a quantitative evaluation of the first-order gray-level statistics for the assessment of the integrity of the equine tendon is questionable.

Integrated framework for developing search and discrimination metrics

NASA Astrophysics Data System (ADS)

Copeland, Anthony C.; Trivedi, Mohan M.

1997-06-01

This paper presents an experimental framework for evaluating target signature metrics as models of human visual search and discrimination. This framework is based on a prototype eye tracking testbed, the Integrated Testbed for Eye Movement Studies (ITEMS). ITEMS determines an observer's visual fixation point while he studies a displayed image scene, by processing video of the observer's eye. The utility of this framework is illustrated with an experiment using gray-scale images of outdoor scenes that contain randomly placed targets. Each target is a square region of a specific size containing pixel values from another image of an outdoor scene. The real-world analogy of this experiment is that of a military observer looking upon the sensed image of a static scene to find camouflaged enemy targets that are reported to be in the area. ITEMS provides the data necessary to compute various statistics for each target to describe how easily the observers located it, including the likelihood the target was fixated or identified and the time required to do so. The computed values of several target signature metrics are compared to these statistics, and a second-order metric based on a model of image texture was found to be the most highly correlated.

Automation of film densitometry for application in personal monitoring.

PubMed

Taheri, M; Movafeghi, A; Rastkhah, N

2011-03-01

In this research work, a semi-automatic densitometry system has been developed for large-scale monitoring services by use of film badge dosemeters. The system consists of a charge-coupled device (CCD)-based scanner that can scan optical densities (ODs) up to 4.2, a computer vision algorithm to improve the quality of digitised films and an analyser program to calculate the necessary information, e.g. the mean OD of region of interest and radiation doses. For calibration of the system, two reference films were used. The Microtek scanner International Color Consortium (ICC) profiler is applied for determining the colour attributes of the scanner accurately and a reference of the density step tablet, Bundesanstalt für Materialforschung und-prüfung (BAM) is used for calibrating the automatic conversion of gray-level values to OD values in the range of 0.2-4.0 OD. The system contributes to achieve more objectives and reliable results. So by applying this system, we can digitise a set of 20 films at once and calculate their relative doses less than about 4 min, and meanwhile it causes to avoid disadvantages of manual process and to enhance the accuracy of dosimetry.

Carbon nanoparticle doped micro-patternable nano-composites for wearable sensing applications (Conference Presentation)

NASA Astrophysics Data System (ADS)

Khosla, Ajit

2017-04-01

This talk focuses on preparation, characterization and micropatterning of electrically conducting KETJENBLACK carbon black nanoparticle (80 nm-diameter) doped Polydimethylsiloxane (PDMS) by employing extrusion mixing. Previously, we had reported fabrication of various micropatternable nanocomposites for wearable sensing applications vis solvent assisted ultrasonic mixing technique[1-16] . Extrusion mixing has an advantage as no organic solvents are used and homogenous dispersion of carbon nanoparticles is observed, which is confirmed by SEM analysis. The developed nanocomposite can be micropatterened using standard microfabrication techniques. It is also observed that percolation threshold occurs at 0.51 wt% of carbon nanoparticles in polymer matrix. Examples of developed nano-composites for wearable sensing applications for precision medicine will also be discussed. References: 1.http://summit.sfu.ca/item/12017 A. Khosla. Micropatternable multifunctional nanocomposite polymers for flexible soft MEMS applications. Diss. Applied Science: School of Engineering Science, 2011. 2. A. Khosla ; B. L. Gray; Fabrication of multiwalled carbon nanotube polydimethylsiloxne nanocomposite polymer flexible microelectrodes for microfluidics and MEMS. Proc. SPIE 7642, Electroactive Polymer Actuators and Devices (EAPAD) 2010, 76421V (April 09, 2010); doi:10.1117/12.847292. 3. Ang Li ; Ajit Khosla ; Connie Drewbrook ; Bonnie L. Gray; Fabrication and testing of thermally responsive hydrogel-based actuators using polymer heater elements for flexible microvalves. Proc. SPIE 7929, Microfluidics, BioMEMS, and Medical Microsystems IX, 79290G (February 14, 2011); doi:10.1117/12.873197. 4. Khosla, A. and Gray, B. L. (2010), Preparation, Micro-Patterning and Electrical Characterization of Functionalized Carbon-Nanotube Polydimethylsiloxane Nanocomposite Polymer. Macromol. Symp., 297: 210-218. doi:10.1002/masy.200900165 5. A. Khosla ; D. Hilbich ; C. Drewbrook ; D. Chung ; B. L. Gray; Large scale micropatterning of multi-walled carbon nanotube/polydimethylsiloxane nanocomposite polymer on highly flexible 12×24 inch substrates. Proc. SPIE 7926, Micromachining and Microfabrication Process Technology XVI, 79260L (February 15, 2011); doi:10.1117/12.876738. 6. A. Khosla, and Bonnie L. Gray. "(Invited) Micropatternable Multifunctional Nanocomposite Polymers for Flexible Soft NEMS and MEMS Applications." ECS Transactions 45.3 (2012): 477-494. doi: 10.1149/1.3700913 7. Khosla, Ajit. "Nanoparticle-doped electrically-conducting polymers for flexible nano-micro Systems." Electrochemical Society Interface 21.3-4 (2012): 67-70. 8. Ajit Khosla; Smart garments in chronic disease management: progress and challenges. Proc. SPIE 8548, Nanosystems in Engineering and Medicine, 85482O (October 24, 2012); doi:10.1117/12.979667. 9. D. Chung ; A. Khosla ; B. L. Gray; Screen printable flexible conductive nanocomposite polymer with applications to wearable sensors. Proc. SPIE 9060, Nanosensors, Biosensors, and Info-Tech Sensors and Systems 2014, 90600U (April 16, 2014); doi:10.1117/12.2046548. 10. Daehan Chung ; Sam Seyfollahi ; Ajit Khosla ; Bonnie Gray ; Ash Parameswaran ; Ramani Ramaseshan ; Kirpal Kohli; Initial experiments with flexible conductive electrodes for potential applications in cancer tissue screening. Proc. SPIE 7929, Microfluidics, BioMEMS, and Medical Microsystems IX, 79290Z (February 14, 2011); doi:10.1117/12.875563. 11. A. Khosla ; B. L. Gray; New technologies for large-scale micropatterning of functional nanocomposite polymers. Proc. SPIE 8344, Nanosensors, Biosensors, and Info-Tech Sensors and Systems 2012, 83440W (April 26, 2012); doi:10.1117/12.915178. 12. A. Khosla, B.L. Gray, Preparation, characterization and micromolding of multi-walled carbon nanotube polydimethylsiloxane conducting nanocomposite polymer, Materials Letters, Volume 63, Issues 13-14, 31 May 2009, Pages 1203-1206, ISSN 0167-577X, http://dx.doi.org/10.1016/j.matlet.2009.02.043. 13. Giassa, M., Khosla, A., Gray, B. et al. J Electron Test (2010) 26: 139. doi:10.1007/s10836-009-5125-3 14.Ozhikandathil, Jayan, Ajit Khosla, and Muthukumaran Packirisamy. "Electrically Conducting PDMS Nanocomposite Using In Situ Reduction of Gold Nanostructures and Mechanical Stimulation of Carbon Nanotubes and Silver Nanoparticles." ECS Journal of Solid State Science and Technology 4.10 (2015): S3048-S3052. doi:10.1149/2.0091510jss 15. Kassegne, Sam, Maria Vomero, Roberto Gavuglio, Mieko Hirabayashi, Emre Özyilmaz, Sebastien Nguyen, Jesus Rodriguez, Eda Özyilmaz, Pieter van Niekerk, and Ajit Khosla. "Electrical impedance, electrochemistry, mechanical stiffness, and hardness tunability in glassy carbon MEMS μECoG electrodes." Microelectronic Engineering 133 (2015): 36-44. 16. A. Khosla ; B. L. Gray; Fabrication and properties of conductive micromoldable thermosetting polymer for electronic routing in highly flexible microfluidic systems. Proc. SPIE 7593, Microfluidics, BioMEMS, and Medical Microsystems VIII, 759314 (February 17, 2010); doi:10.1117/12.840911.

Metabolic Engineering oil biosyntesis pathways in Lesquerella Fendleri(Abstract)

USDA-ARS?s Scientific Manuscript database

Lesquerella fendleri (A. Gray) S. Wats. (Brassicaceae), being developed as a new industrial oilseed crop in the southwestern region of the United States, is valued for its unusual hydroxy fatty acid (HFA) in seed. The majority of HFA in L. fendleri is lesquerolic acid (14-hydroxy-eicos-cis-11-enoic...

Estimating local scaling properties for the classification of interstitial lung disease patterns

NASA Astrophysics Data System (ADS)

Huber, Markus B.; Nagarajan, Mahesh B.; Leinsinger, Gerda; Ray, Lawrence A.; Wismueller, Axel

2011-03-01

Local scaling properties of texture regions were compared in their ability to classify morphological patterns known as 'honeycombing' that are considered indicative for the presence of fibrotic interstitial lung diseases in high-resolution computed tomography (HRCT) images. For 14 patients with known occurrence of honeycombing, a stack of 70 axial, lung kernel reconstructed images were acquired from HRCT chest exams. 241 regions of interest of both healthy and pathological (89) lung tissue were identified by an experienced radiologist. Texture features were extracted using six properties calculated from gray-level co-occurrence matrices (GLCM), Minkowski Dimensions (MDs), and the estimation of local scaling properties with Scaling Index Method (SIM). A k-nearest-neighbor (k-NN) classifier and a Multilayer Radial Basis Functions Network (RBFN) were optimized in a 10-fold cross-validation for each texture vector, and the classification accuracy was calculated on independent test sets as a quantitative measure of automated tissue characterization. A Wilcoxon signed-rank test was used to compare two accuracy distributions including the Bonferroni correction. The best classification results were obtained by the set of SIM features, which performed significantly better than all the standard GLCM and MD features (p < 0.005) for both classifiers with the highest accuracy (94.1%, 93.7%; for the k-NN and RBFN classifier, respectively). The best standard texture features were the GLCM features 'homogeneity' (91.8%, 87.2%) and 'absolute value' (90.2%, 88.5%). The results indicate that advanced texture features using local scaling properties can provide superior classification performance in computer-assisted diagnosis of interstitial lung diseases when compared to standard texture analysis methods.

50 CFR 32.34 - Iowa.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., bobwhite quail, gray partridge, rabbit (cottontail and jack), squirrel (fox and gray), groundhog, raccoon... pheasant, gray partridge, rabbit (cottontail and jack), squirrel (fox and gray), groundhog, raccoon... rabbit, gray and fox squirrel, and fall wild turkey (2 weeks within the season) on designated areas of...

Cerebral Perfusion and Gray Matter Changes Associated With Chemotherapy-Induced Peripheral Neuropathy.

PubMed

Nudelman, Kelly N H; McDonald, Brenna C; Wang, Yang; Smith, Dori J; West, John D; O'Neill, Darren P; Zanville, Noah R; Champion, Victoria L; Schneider, Bryan P; Saykin, Andrew J

2016-03-01

To investigate the longitudinal relationship between chemotherapy-induced peripheral neuropathy (CIPN) symptoms (sx) and brain perfusion changes in patients with breast cancer. Interaction of CIPN-sx perfusion effects with known chemotherapy-associated gray matter density decrease was also assessed to elucidate the relationship between CIPN and previously reported cancer treatment-related brain structural changes. Patients with breast cancer treated with (n = 24) or without (n = 23) chemotherapy underwent clinical examination and brain magnetic resonance imaging at the following three time points: before treatment (baseline), 1 month after treatment completion, and 1 year after the 1-month assessment. CIPN-sx were evaluated with the self-reported Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity four-item sensory-specific scale. Perfusion and gray matter density were assessed using voxel-based pulsed arterial spin labeling and morphometric analyses and tested for association with CIPN-sx in the patients who received chemotherapy. Patients who received chemotherapy reported significantly increased CIPN-sx from baseline to 1 month, with partial recovery by 1 year (P < .001). CIPN-sx increase from baseline to 1 month was significantly greater for patients who received chemotherapy compared with those who did not (P = .001). At 1 month, neuroimaging showed that for the group that received chemotherapy, CIPN-sx were positively associated with cerebral perfusion in the right superior frontal gyrus and cingulate gyrus, regions associated with pain processing (P < .001). Longitudinal magnetic resonance imaging analysis in the group receiving chemotherapy indicated that CIPN-sx and associated perfusion changes from baseline to 1 month were also positively correlated with gray matter density change (P < .005). Peripheral neuropathy symptoms after systemic chemotherapy for breast cancer are associated with changes in cerebral perfusion and gray matter. The specific mechanisms warrant further investigation given the potential diagnostic and therapeutic implications. © 2015 by American Society of Clinical Oncology.

Cerebral Perfusion and Gray Matter Changes Associated With Chemotherapy-Induced Peripheral Neuropathy

PubMed Central

Nudelman, Kelly N.H.; McDonald, Brenna C.; Wang, Yang; Smith, Dori J.; West, John D.; O'Neill, Darren P.; Zanville, Noah R.; Champion, Victoria L.; Schneider, Bryan P.

2016-01-01

Purpose To investigate the longitudinal relationship between chemotherapy-induced peripheral neuropathy (CIPN) symptoms (sx) and brain perfusion changes in patients with breast cancer. Interaction of CIPN-sx perfusion effects with known chemotherapy-associated gray matter density decrease was also assessed to elucidate the relationship between CIPN and previously reported cancer treatment–related brain structural changes. Methods Patients with breast cancer treated with (n = 24) or without (n = 23) chemotherapy underwent clinical examination and brain magnetic resonance imaging at the following three time points: before treatment (baseline), 1 month after treatment completion, and 1 year after the 1-month assessment. CIPN-sx were evaluated with the self-reported Functional Assessment of Cancer Therapy/Gynecologic Oncology Group–Neurotoxicity four-item sensory-specific scale. Perfusion and gray matter density were assessed using voxel-based pulsed arterial spin labeling and morphometric analyses and tested for association with CIPN-sx in the patients who received chemotherapy. Results Patients who received chemotherapy reported significantly increased CIPN-sx from baseline to 1 month, with partial recovery by 1 year (P < .001). CIPN-sx increase from baseline to 1 month was significantly greater for patients who received chemotherapy compared with those who did not (P = .001). At 1 month, neuroimaging showed that for the group that received chemotherapy, CIPN-sx were positively associated with cerebral perfusion in the right superior frontal gyrus and cingulate gyrus, regions associated with pain processing (P < .001). Longitudinal magnetic resonance imaging analysis in the group receiving chemotherapy indicated that CIPN-sx and associated perfusion changes from baseline to 1 month were also positively correlated with gray matter density change (P < .005). Conclusion Peripheral neuropathy symptoms after systemic chemotherapy for breast cancer are associated with changes in cerebral perfusion and gray matter. The specific mechanisms warrant further investigation given the potential diagnostic and therapeutic implications. PMID:26527786

Imaging Findings Associated with Cognitive Performance in Primary Lateral Sclerosis and Amyotrophic Lateral Sclerosis

PubMed Central

Meoded, Avner; Kwan, Justin Y.; Peters, Tracy L.; Huey, Edward D.; Danielian, Laura E.; Wiggs, Edythe; Morrissette, Arthur; Wu, Tianxia; Russell, James W.; Bayat, Elham; Grafman, Jordan; Floeter, Mary Kay

2013-01-01

Introduction Executive dysfunction occurs in many patients with amyotrophic lateral sclerosis (ALS), but it has not been well studied in primary lateral sclerosis (PLS). The aims of this study were to (1) compare cognitive function in PLS to that in ALS patients, (2) explore the relationship between performance on specific cognitive tests and diffusion tensor imaging (DTI) metrics of white matter tracts and gray matter volumes, and (3) compare DTI metrics in patients with and without cognitive and behavioral changes. Methods The Delis-Kaplan Executive Function System (D-KEFS), the Mattis Dementia Rating Scale (DRS-2), and other behavior and mood scales were administered to 25 ALS patients and 25 PLS patients. Seventeen of the PLS patients, 13 of the ALS patients, and 17 healthy controls underwent structural magnetic resonance imaging (MRI) and DTI. Atlas-based analysis using MRI Studio software was used to measure fractional anisotropy, and axial and radial diffusivity of selected white matter tracts. Voxel-based morphometry was used to assess gray matter volumes. The relationship between diffusion properties of selected association and commissural white matter and performance on executive function and memory tests was explored using a linear regression model. Results More ALS than PLS patients had abnormal scores on the DRS-2. DRS-2 and D-KEFS scores were related to DTI metrics in several long association tracts and the callosum. Reduced gray matter volumes in motor and perirolandic areas were not associated with cognitive scores. Conclusion The changes in diffusion metrics of white matter long association tracts suggest that the loss of integrity of the networks connecting fronto-temporal areas to parietal and occipital areas contributes to cognitive impairment. PMID:24052798

Cognitive dysfunctions in middle-aged type 2 diabetic patients and neuroimaging correlations: a cross-sectional study.

PubMed

García-Casares, Natalia; Jorge, Ricardo E; García-Arnés, Juan A; Acion, Laura; Berthier, Marcelo L; Gonzalez-Alegre, Pedro; Nabrozidis, Alejandro; Gutiérrez, Antonio; Ariza, María José; Rioja, Jose; González-Santos, Pedro

2014-01-01

The aim was to assess the neuropsychological performance of a group of middle-aged patients with well-controlled type 2 diabetes mellitus (T2DM) and to examine whether the neuropsychological deficits correlate with structural and functional brain alterations. We compared 25 subjects with T2DM aged 45-65 years with 25 control participants matched for age, gender, and educational level. The neuropsychological battery was designed to examine executive functions, attention, information processing speed, and verbal memory. Severity of depression was assessed using the Hamilton Depression Rating Scale and cardiovascular risk factors were assessed using the Framingham Cardiovascular Risk Profile Score. The presence of at least one APOEε4 allele was determined. Reduced gray matter density was analyzed using voxel-based morphometry and brain glucose metabolic changes were assessed by 18FDG-PET. T2DM subjects had significantly lower scores than subjects without T2DM in the Trail-making Test B (p < 0.004), Color-Word Stroop test (p < 0.005), Semantic Fluency (p < 0.006), Digit-Symbol modalities test (p < 0.02), Text Recall from the Wechsler Memory Scale (p < 0.0001), Rey-Osterrieth Complex Figure-copy (p < 0.004), and delayed reproduction (p < 0.03). Worse executive functions and memory functioning correlated predominantly with less gray matter density and reduced glucose metabolism in the orbital and prefrontal cortex, temporal (middle gyrus, parahippocampus and uncus), and cerebellum regions (p < 0.001). T2DM subjects presented cognitive dysfunctions compared with controls. Clinical-neuroimaging correlations corresponded to brain changes (reduced gray matter density and glucose metabolism) mainly in fronto-temporal areas.

Regional gray matter density associated with emotional intelligence: evidence from voxel-based morphometry.

PubMed

Takeuchi, Hikaru; Taki, Yasuyuki; Sassa, Yuko; Hashizume, Hiroshi; Sekiguchi, Atsushi; Fukushima, Ai; Kawashima, Ryuta

2011-09-01

Emotional Intelligence (EI) is the ability to monitor one's own and others' emotions and the ability to use the gathered information to guide one's thinking and action. EI is thought to be important for social life making it a popular subject of research. However, despite the existence of previous functional imaging studies on EI, the relationship between regional gray matter morphology and EI has never been investigated. We used voxel-based morphometry (VBM) and a questionnaire (Emotional Intelligence Scale) to measure EI to identify the gray matter correlates of each factor of individual EI (Intrapersonal factor, Interpersonal factor, Situation Management factor). We found significant negative relationships between the Intrapersonal factor and regional gray matter density (rGMD) (1-a) in an anatomical cluster that included the right anterior insula, (1-b) in the right cerebellum, (1-c) in an anatomical cluster that extends from the cuneus to the precuneus, (1-d) and in an anatomical cluster that extends from the medial prefrontal cortex to the left lateral fronto-polar cortex. We also found significant positive correlations between the Interpersonal factor and rGMD in the right superior temporal sulcus, and significant negative correlations between the Situation Management factor and rGMD in the ventromedial prefrontal cortex. These findings suggest that each factor of EI in healthy young people is related to the specific brain regions known to be involved in the networks of social cognition and self-related recognition, and in the somatic marker circuitry. Copyright © 2010 Wiley-Liss, Inc.

Do Consultation Psychiatrists, Forensic Psychiatrists, Psychiatry Trainees, and Health Care Lawyers Differ in Opinion on Gray Area Decision-Making Capacity Cases? A Vignette-Based Survey.

PubMed

Armontrout, James; Gitlin, David; Gutheil, Thomas

2016-01-01

Previous research in the area of medical decision-making capacity has demonstrated relatively poor agreement between experienced evaluators in "gray area" cases. We performed a survey to determine the level of agreement about gray area decision-making capacity case scenarios within and between individuals of different professional backgrounds. Participants received a survey consisting of 3 complicated decision-making capacity vignettes with an accompanying "yes/no" question regarding capacity and a certainty scale for each vignette. Participants were identified from mailing lists of professional organizations and local hospitals. We received responses from psychiatry trainees, consultation-liaison psychiatrists, forensic psychiatrists, and lawyers with experience in health care law. Results were analyzed using SPSS. Across the 3 vignettes, the percentage agreeing that the individual described had capacity to refuse medical treatment ranged between 35% and 40% for trainees, 33% and 67% for consult psychiatrists, 41% and 76% for forensic psychiatrists, and 40% and 83% for health care lawyers. Only question 2 reached significance between-group differences (Pearson χ(2) = 11.473, p < 0.01). Across vignettes, trainees were less likely to consider patients to have capacity for decision-making than were forensic psychiatrists and lawyers. As found in previous research, agreement among experienced evaluators appears generally low in gray area capacity cases. It is noteworthy that individuals of different professional backgrounds at times offer divergent between-group opinions on capacity. Copyright © 2016 The Academy of Psychosomatic Medicine. Published by Elsevier Inc. All rights reserved.

Brain changes in children and adolescents with obsessive-compulsive disorder before and after treatment: a voxel-based morphometric MRI study.

PubMed

Lázaro, Luisa; Bargalló, Nuria; Castro-Fornieles, Josefina; Falcón, Carles; Andrés, Susana; Calvo, Rosa; Junqué, Carme

2009-05-15

The aim of this study is to determine whether children and adolescents with treatment-naïve obsessive-compulsive disorder (OCD) present brain structure differences in comparison with healthy subjects, and to evaluate brain changes after treatment and clinical improvement. Initial and 6 months' follow-up evaluations were performed in 15 children and adolescents (age range=9-17 years, mean=13.7, S.D.=2.5; 8 male, 7 female) with DSM-IV OCD and 15 healthy subjects matched for age, sex and estimated intellectual level. An evaluation with psychopathological scales and magnetic resonance imaging (MRI) was carried out at admission and after 6 months' follow-up. Axial three-dimensional T1-weighted images were obtained in a 1.5 T scanner and analysed using optimized voxel-based morphometry (VBM) and longitudinal VBM approaches. Compared with controls, OCD patients presented significantly less gray matter volume bilaterally in right and left parietal lobes and right parietal white matter (P=0.001 FWE corrected) at baseline evaluation. After 6 months of treatment, and with a clear clinical improvement, the differences between OCD patients and controls in the parietal lobes in gray and white matter were no longer statistically significant. During follow-up in the longitudinal study, an increase in gray matter volume in the right striatum of OCD patients was observed, though the difference was not statistically significant. Children and adolescents with untreated OCD present gray and white matter decreases in lateral parietal cortices, but this abnormality is reversible after clinical improvement.

Importance of extended spatial coverage for quantitative susceptibility mapping of iron-rich deep gray matter.

PubMed

Elkady, Ahmed M; Sun, Hongfu; Wilman, Alan H

2016-05-01

Quantitative Susceptibility Mapping (QSM) is an emerging area of brain research with clear application to brain iron studies in deep gray matter. However, acquisition of standard whole brain QSM can be time-consuming. One means to reduce scan time is to use a focal acquisition restricted only to the regions of interest such as deep gray matter. However, the non-local dipole field necessary for QSM reconstruction extends far beyond the structure of interest. We demonstrate the practical implications of these non-local fields on the choice of brain volume for QSM. In an illustrative numerical simulation and then in human brain experiments, we examine the effect on QSM of volume reduction in each dimension. For the globus pallidus, as an example of iron-rich deep gray matter, we demonstrate that substantial errors can arise even when the field-of-view far exceeds the physical structural boundaries. Thus, QSM reconstruction requires a non-local field-of-view prescription to ensure minimal errors. An axial QSM acquisition, centered on the globus pallidus, should encompass at least 76mm in the superior-inferior direction to conserve susceptibility values from the globus pallidus. This dimension exceeds the physical coronal extent of this structure by at least five-fold. As QSM sees wider use in the neuroscience community, its unique requirement for an extended field-of-view needs to be considered. Copyright © 2016 Elsevier Inc. All rights reserved.

Neurofilament light protein in blood predicts regional atrophy in Huntington disease.

PubMed

Johnson, Eileanoir B; Byrne, Lauren M; Gregory, Sarah; Rodrigues, Filipe B; Blennow, Kaj; Durr, Alexandra; Leavitt, Blair R; Roos, Raymund A; Zetterberg, Henrik; Tabrizi, Sarah J; Scahill, Rachael I; Wild, Edward J

2018-02-20

Neurofilament light (NfL) protein in blood plasma has been proposed as a prognostic biomarker of neurodegeneration in a number of conditions, including Huntington disease (HD). This study investigates the regional distribution of NfL-associated neural pathology in HD gene expansion carriers. We examined associations between NfL measured in plasma and regionally specific atrophy in cross-sectional (n = 198) and longitudinal (n = 177) data in HD gene expansion carriers from the international multisite TRACK-HD study. Using voxel-based morphometry, we measured associations between baseline NfL levels and both baseline gray matter and white matter volume; and longitudinal change in gray matter and white matter over the subsequent 3 years in HD gene expansion carriers. After controlling for demographics, associations between increased NfL levels and reduced brain volume were seen in cortical and subcortical gray matter and within the white matter. After also controlling for known predictors of disease progression (age and CAG repeat length), associations were limited to the caudate and putamen. Longitudinally, NfL predicted subsequent occipital gray matter atrophy and widespread white matter reduction, both before and after correction for other predictors of disease progression. These findings highlight the value of NfL as a dynamic marker of brain atrophy and, more generally, provide further evidence of the strong association between plasma NfL level, a candidate blood biomarker, and pathologic neuronal change. © 2018 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.

Structural and behavioral correlates of abnormal encoding of money value in the sensorimotor striatum in cocaine addiction

PubMed Central

Konova, Anna B.; Moeller, Scott J.; Tomasi, Dardo; Parvaz, Muhammad A.; Alia-Klein, Nelly; Volkow, Nora D.; Goldstein, Rita Z.

2012-01-01

Abnormalities in frontostriatal systems are thought to be central to the pathophysiology of addiction, and may underlie maladaptive processing of the highly generalizable reinforcer, money. Although abnormal frontostriatal structure and function have been observed in individuals addicted to cocaine, it is less clear how individual variability in brain structure is associated with brain function to influence behavior. Our objective was to examine frontostriatal structure and neural processing of money value in chronic cocaine users and closely matched healthy controls. A reward task that manipulated different levels of money was used to isolate neural activity associated with money value. Gray matter volume measures were used to assess frontostriatal structure. Our results indicated that cocaine users had an abnormal money value signal in the sensorimotor striatum (right putamen/globus pallidus) which was negatively associated with accuracy adjustments to money and was more pronounced in individuals with more severe use. In parallel, group differences were also observed in both function and gray matter volume of the ventromedial prefrontal cortex; in the cocaine users, the former was directly associated with response to money in the striatum. These results provide strong evidence for abnormalities in the neural mechanisms of valuation in addiction and link these functional abnormalities with deficits in brain structure. In addition, as value signals represent acquired associations, their abnormal processing in the sensorimotor striatum, a region centrally implicated in habit formation, could signal disadvantageous associative learning in cocaine addiction. PMID:22775285

Intensity inhomogeneity correction for magnetic resonance imaging of human brain at 7T.

PubMed

Uwano, Ikuko; Kudo, Kohsuke; Yamashita, Fumio; Goodwin, Jonathan; Higuchi, Satomi; Ito, Kenji; Harada, Taisuke; Ogawa, Akira; Sasaki, Makoto

2014-02-01

To evaluate the performance and efficacy for intensity inhomogeneity correction of various sequences of the human brain in 7T MRI using the extended version of the unified segmentation algorithm. Ten healthy volunteers were scanned with four different sequences (2D spin echo [SE], 3D fast SE, 2D fast spoiled gradient echo, and 3D time-of-flight) by using a 7T MRI system. Intensity inhomogeneity correction was performed using the "New Segment" module in SPM8 with four different values (120, 90, 60, and 30 mm) of full width at half maximum (FWHM) in Gaussian smoothness. The uniformity in signals in the entire white matter was evaluated using the coefficient of variation (CV); mean signal intensities between the subcortical and deep white matter were compared, and contrast between subcortical white matter and gray matter was measured. The length of the lenticulostriate (LSA) was measured on maximum intensity projection (MIP) images in the original and corrected images. In all sequences, the CV decreased as the FWHM value decreased. The differences of mean signal intensities between subcortical and deep white matter also decreased with smaller FWHM values. The contrast between white and gray matter was maintained at all FWHM values. LSA length was significantly greater in corrected MIP than in the original MIP images. Intensity inhomogeneity in 7T MRI can be successfully corrected using SPM8 for various scan sequences.

Interactions of allele E of the MC1R gene with FM and mutations in the MLPH gene cause the five-gray phenotype in the Anyi tile-like gray chicken.

PubMed

Xu, J G; Xie, M G; Zou, S Y; Liu, X F; Li, X H; Xie, J F; Zhang, X Q

2016-04-26

The Anyi tile-like gray chicken is a Chinese indigenous breed with a gray dilution phenotype, having gray feathers, comb, skin, shanks, and beak, which is valuable for genetic research on pigmentation. However, the genetic basis of the gray dilution phenotype remains unknown. The objective of this study was to investigate the genetic basis of the gray dilution phenotype in the Anyi tile-like gray chicken. We found that all Anyi tile-like gray chickens tested in this study carried at least one E allele, which is responsible for the appearance of black feathers, and some of them carried the FM allele, which is responsible for the black skin phenotype. A single nucleotide polymorphism (C.1909A>G) was identified within the melanophilin (MLPH) gene and was significantly associated with the gray dilution phenotype. Our findings suggest that the E and FM alleles act together to cause the development of the "five-black" phenotype (black feather, comb, skin, shank, and beak), whereas the MLPH mutation results in defective melanosome transport, leading to the development of the "five-gray" phenotype.

Searls prairie clover (Dalea searlsiae) for rangeland revegetation: Phenotypic and genetic evaluations

Treesearch

Kishor Bhattarai; Shaun Bushman; Douglas A. Johnson; John G. Carman

2011-01-01

Few North American legumes are available for use in rangeland revegetation in the western USA, but Searls prairie clover [Dalea searlsiae (A. Gray) Barneby] is one that holds promise. Commercial-scale seed production of this species could address the issues of unreliable seed availability and high seed costs associated with its wildland seed collection. To evaluate its...

Exploring methods for prevention of oxidative stain in soft maple

Treesearch

Michael C. Wiemann; Richard D. Bergman; Mark Knaebe; Scott A. Bowe

2009-01-01

Interior gray enzymatic oxidative stain for white woods such as maple has plagued the wood industry for many years because methods that have been found to reduce stain are hard to scale up to industrial levels. We examined possible alternative treatments to eliminate stain in soft maple (Acer rubrum L.), and found that exposure to sulfur dioxide gas eliminates interior...

Oral Reading Fluency as a Predictor of Silent Reading Fluency at Secondary and Postsecondary Levels

ERIC Educational Resources Information Center

Seok, Soonhwa; DaCosta, Boaventura

2014-01-01

This research investigated oral reading fluency as a predictor of silent reading fluency at the secondary and postsecondary levels. Several measures were used, including the Gray Oral Reading Test, the Test of Silent Word Reading Fluency, the Test of Silent Contextual Reading Fluency, and the Reading Observation Scale. A total of 223 students…

Finding External Indicators of Load on a Web Server via Analysis of Black-Box Performance Measurements

ERIC Educational Resources Information Center

Chiarini, Marc A.

2010-01-01

Traditional methods for system performance analysis have long relied on a mix of queuing theory, detailed system knowledge, intuition, and trial-and-error. These approaches often require construction of incomplete gray-box models that can be costly to build and difficult to scale or generalize. In this thesis, we present a black-box analysis…

A prototype retinal prosthesis for visual stimulation.

PubMed

Abu-Faraj, Ziad O; Rjeily, Dany M Abou; Nasreddine, Rayan W; Andari, Majid A; Taok, Habib H

2007-01-01

Vision loss has severe impacts on its victims, carrying with it physiological, psychological, social, and economic consequences thereby degrading the quality of life and depriving the individual from performing many of the daily living activities. This article describes the design and development of a prototype retinal prosthesis for visual stimulation. The system consists of a webcam, a notebook computer, and a prototype excitatory circuit. The system is driven by a MATLAB-based custom-built software. Live webcam images are converted to an 8 x 8 mosaic of 256 gray scale shades. Subsequently, electrical impulses are generated by the excitatory circuit in real-time to topographically stimulate the corresponding epiretinal cells. Following their conversion to gray scale, recorded data from the central pixel of the mosaic yielded: 36.24 nC for black, 48.48 nC for red, 55.68 nC for green, 67.68 nC for blue, and 91.92 nC for white. These results correlate well with data reported in the literature. The hallmark of this work is in the potential of partial restoration of sight that would add quality to the life of individuals with vision loss.

Optimized lighting method of applying shaped-function signal for increasing the dynamic range of LED-multispectral imaging system

NASA Astrophysics Data System (ADS)

Yang, Xue; Hu, Yajia; Li, Gang; Lin, Ling

2018-02-01

This paper proposes an optimized lighting method of applying a shaped-function signal for increasing the dynamic range of light emitting diode (LED)-multispectral imaging system. The optimized lighting method is based on the linear response zone of the analog-to-digital conversion (ADC) and the spectral response of the camera. The auxiliary light at a higher sensitivity-camera area is introduced to increase the A/D quantization levels that are within the linear response zone of ADC and improve the signal-to-noise ratio. The active light is modulated by the shaped-function signal to improve the gray-scale resolution of the image. And the auxiliary light is modulated by the constant intensity signal, which is easy to acquire the images under the active light irradiation. The least square method is employed to precisely extract the desired images. One wavelength in multispectral imaging based on LED illumination was taken as an example. It has been proven by experiments that the gray-scale resolution and the accuracy of information of the images acquired by the proposed method were both significantly improved. The optimum method opens up avenues for the hyperspectral imaging of biological tissue.

Optimized lighting method of applying shaped-function signal for increasing the dynamic range of LED-multispectral imaging system.

PubMed

Yang, Xue; Hu, Yajia; Li, Gang; Lin, Ling

2018-02-01

This paper proposes an optimized lighting method of applying a shaped-function signal for increasing the dynamic range of light emitting diode (LED)-multispectral imaging system. The optimized lighting method is based on the linear response zone of the analog-to-digital conversion (ADC) and the spectral response of the camera. The auxiliary light at a higher sensitivity-camera area is introduced to increase the A/D quantization levels that are within the linear response zone of ADC and improve the signal-to-noise ratio. The active light is modulated by the shaped-function signal to improve the gray-scale resolution of the image. And the auxiliary light is modulated by the constant intensity signal, which is easy to acquire the images under the active light irradiation. The least square method is employed to precisely extract the desired images. One wavelength in multispectral imaging based on LED illumination was taken as an example. It has been proven by experiments that the gray-scale resolution and the accuracy of information of the images acquired by the proposed method were both significantly improved. The optimum method opens up avenues for the hyperspectral imaging of biological tissue.

Practice Guidelines for the Management of Multiligamentous Injuries of the Knee

PubMed Central

Goyal, Ankit; Tanwar, Milind; Joshi, Deepak; Chaudhary, Deepak

2017-01-01

Background: Multiligamentous injuries of knee remain a gray area as far as guidelines for management are concerned due to absence of large-scale, prospective controlled trials. This article reviews the recent evidence-based literature and trends in treatment of multiligamentous injuries and establishes the needful protocol, keeping in view the current concepts. Materials and Methods: Two reviewers individually assessed the available data indexed on PubMed and Medline and compiled data on incidence, surgical versus nonsurgical treatment, timing of surgery, and repair versus reconstruction of multiligamentous injury. Results: Evolving trends do not clearly describe treatment, but most studies have shown increasing inclination toward an early, staged/single surgical procedure for multiligamentous injuries involving cruciate and collateral ligaments. Medial complex injuries have shown better results with conservative treatment with surgical reconstruction of concomitant injuries. Conclusion: Multiligamentous injury still remains a gray area due to unavailability of a formal guideline to treatment in the absence of large-scale, blinded prospective controlled trials. Any in multiligamentous injuries any intervention needs to be individualized by the presence of any life- or limb-threatening complication. The risks and guarded prognosis with both surgical and non-surgical modalities of treatment should be explained to patient and relations. PMID:28966377

Pore-scale dynamics of salt transport and distribution in drying porous media

NASA Astrophysics Data System (ADS)

Shokri, Nima

2014-01-01

Understanding the physics of water evaporation from saline porous media is important in many natural and engineering applications such as durability of building materials and preservation of monuments, water quality, and mineral-fluid interactions. We applied synchrotron x-ray micro-tomography to investigate the pore-scale dynamics of dissolved salt distribution in a three dimensional drying saline porous media using a cylindrical plastic column (15 mm in height and 8 mm in diameter) packed with sand particles saturated with CaI2 solution (5% concentration by mass) with a spatial and temporal resolution of 12 μm and 30 min, respectively. Every time the drying sand column was set to be imaged, two different images were recorded using distinct synchrotron x-rays energies immediately above and below the K-edge value of Iodine. Taking the difference between pixel gray values enabled us to delineate the spatial and temporal distribution of CaI2 concentration at pore scale. Results indicate that during early stages of evaporation, air preferentially invades large pores at the surface while finer pores remain saturated and connected to the wet zone at bottom via capillary-induced liquid flow acting as evaporating spots. Consequently, the salt concentration increases preferentially in finer pores where evaporation occurs. Higher salt concentration was observed close to the evaporating surface indicating a convection-driven process. The obtained salt profiles were used to evaluate the numerical solution of the convection-diffusion equation (CDE). Results show that the macro-scale CDE could capture the overall trend of the measured salt profiles but fail to produce the exact slope of the profiles. Our results shed new insight on the physics of salt transport and its complex dynamics in drying porous media and establish synchrotron x-ray tomography as an effective tool to investigate the dynamics of salt transport in porous media at high spatial and temporal resolution.

Pore-scale dynamics of salt transport and distribution in drying porous media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shokri, Nima, E-mail: nima.shokri@manchester.ac.uk

2014-01-15

Understanding the physics of water evaporation from saline porous media is important in many natural and engineering applications such as durability of building materials and preservation of monuments, water quality, and mineral-fluid interactions. We applied synchrotron x-ray micro-tomography to investigate the pore-scale dynamics of dissolved salt distribution in a three dimensional drying saline porous media using a cylindrical plastic column (15 mm in height and 8 mm in diameter) packed with sand particles saturated with CaI{sub 2} solution (5% concentration by mass) with a spatial and temporal resolution of 12 μm and 30 min, respectively. Every time the drying sandmore » column was set to be imaged, two different images were recorded using distinct synchrotron x-rays energies immediately above and below the K-edge value of Iodine. Taking the difference between pixel gray values enabled us to delineate the spatial and temporal distribution of CaI{sub 2} concentration at pore scale. Results indicate that during early stages of evaporation, air preferentially invades large pores at the surface while finer pores remain saturated and connected to the wet zone at bottom via capillary-induced liquid flow acting as evaporating spots. Consequently, the salt concentration increases preferentially in finer pores where evaporation occurs. Higher salt concentration was observed close to the evaporating surface indicating a convection-driven process. The obtained salt profiles were used to evaluate the numerical solution of the convection-diffusion equation (CDE). Results show that the macro-scale CDE could capture the overall trend of the measured salt profiles but fail to produce the exact slope of the profiles. Our results shed new insight on the physics of salt transport and its complex dynamics in drying porous media and establish synchrotron x-ray tomography as an effective tool to investigate the dynamics of salt transport in porous media at high spatial and temporal resolution.« less

A Modified Tri-Exponential Model for Multi-b-value Diffusion-Weighted Imaging: A Method to Detect the Strictly Diffusion-Limited Compartment in Brain

PubMed Central

Zeng, Qiang; Shi, Feina; Zhang, Jianmin; Ling, Chenhan; Dong, Fei; Jiang, Biao

2018-01-01

Purpose: To present a new modified tri-exponential model for diffusion-weighted imaging (DWI) to detect the strictly diffusion-limited compartment, and to compare it with the conventional bi- and tri-exponential models. Methods: Multi-b-value diffusion-weighted imaging (DWI) with 17 b-values up to 8,000 s/mm2 were performed on six volunteers. The corrected Akaike information criterions (AICc) and squared predicted errors (SPE) were calculated to compare these three models. Results: The mean f0 values were ranging 11.9–18.7% in white matter ROIs and 1.2–2.7% in gray matter ROIs. In all white matter ROIs: the AICcs of the modified tri-exponential model were the lowest (p < 0.05 for five ROIs), indicating the new model has the best fit among these models; the SPEs of the bi-exponential model were the highest (p < 0.05), suggesting the bi-exponential model is unable to predict the signal intensity at ultra-high b-value. The mean ADCvery−slow values were extremely low in white matter (1–7 × 10−6 mm2/s), but not in gray matter (251–445 × 10−6 mm2/s), indicating that the conventional tri-exponential model fails to represent a special compartment. Conclusions: The strictly diffusion-limited compartment may be an important component in white matter. The new model fits better than the other two models, and may provide additional information. PMID:29535599

Tests of various colorants for application of a Fourier transform infrared imaging system to deciphering obliterated writings

NASA Astrophysics Data System (ADS)

Sugawara, Shigeru

2015-10-01

Obliterated writing is writing that has been obscured by different-colored materials. There are obliterated writings that cannot be detected by conventional methods. A method for deciphering such obliterated writings was developed in this study. Mid-infrared spectroscopic imaging in the wavelength range of 2.5-14 μm was used for deciphering because the infrared spectrum differs among different brands of colorants. Obliterated writings were made by pressing information protection stamps onto characters written by 4 kinds of colorants. The samples were tested for deciphering by the Fourier-transform infrared imaging system. Two peak areas of two specific wavenumber regions of each reflectance spectrum were calculated and the ratio of the two values is displayed as a unique gray scale in the spectroscopic image. As a result, the absorption peak at various wavenumbers could be used to decipher obliterated writings that could not be detected by the conventional methods. Ten different parameters for deciphering obliterated writing were found in this study.

Loss of corticospinal tract integrity in early MS disease stages

PubMed Central

Neumann, Jens; Kaufmann, Jörn; Heidel, Jan; Stadler, Erhard; Sweeney-Reed, Catherine; Sailer, Michael; Schreiber, Stefanie

2017-01-01

Objective: We investigated corticospinal tract (CST) integrity in the absence of white matter (WM) lesions using diffusion tensor imaging (DTI) in early MS disease stages. Methods: Our study comprised 19 patients with clinically isolated syndrome (CIS), 11 patients with relapsing-remitting MS (RRMS), and 32 age- and sex-matched healthy controls, for whom MRI measures of CST integrity (fractional anisotropy [FA], mean diffusivity [MD]), T1- and T2-based lesion load, and brain volumes were available. The mean (SD) disease duration was 3.5 (2.1) months, and disability score was low (median Expanded Disability Status Scale 1.5) at the time of the study. Results: Patients with CIS and RRMS had significantly lower CST FA and higher CST MD values compared with controls. These findings were present, irrespective of whether WM lesions affected the CST. However, no group differences in the overall gray or WM volume were identified. Conclusions: In early MS disease stages, CST integrity is already affected in the absence of WM lesions or brain atrophy. PMID:28959706

Onset of molar incisor hypomineralization (MIH).

PubMed

Fagrell, Tobias G; Salmon, Phil; Melin, Lisa; Norén, Jörgen G

2013-01-01

The etiological factors and timing of the onset of molar incisor hypomineralization (MIH) are still not clear. The aim of this study was to examine ground radial and sagittal sections from teeth diagnosed with MIH using light microscopy, polarized light microscopy and X-ray micro-computed tomography (XMCT) and to estimate the onset and timing of the MIH and to relate the hypomineralized enamel to the incremental lines. Thirteen extracted permanent first molars diagnosed MIH, were analyzed with light microscopy and XMCT. The hypomineralized areas were mainly located in the mesio-buccal cusps, starting at the enamel-dentin-junction and continuing towards the enamel surface. In a relative gray scale analysis the values decreased from the EDJ towards the enamel surface. The findings indicate that the ameloblasts in the hypomineralized enamel are capable of forming an enamel of normal thickness, but with a substantial reduction of their capacity for maturation of enamel. Chronologically, it is estimated that the timing of the disturbance is at a period during the first 6-7 months of age.

Optimization of OT-MACH Filter Generation for Target Recognition

NASA Technical Reports Server (NTRS)

Johnson, Oliver C.; Edens, Weston; Lu, Thomas T.; Chao, Tien-Hsin

2009-01-01

An automatic Optimum Trade-off Maximum Average Correlation Height (OT-MACH) filter generator for use in a gray-scale optical correlator (GOC) has been developed for improved target detection at JPL. While the OT-MACH filter has been shown to be an optimal filter for target detection, actually solving for the optimum is too computationally intensive for multiple targets. Instead, an adaptive step gradient descent method was tested to iteratively optimize the three OT-MACH parameters, alpha, beta, and gamma. The feedback for the gradient descent method was a composite of the performance measures, correlation peak height and peak to side lobe ratio. The automated method generated and tested multiple filters in order to approach the optimal filter quicker and more reliably than the current manual method. Initial usage and testing has shown preliminary success at finding an approximation of the optimal filter, in terms of alpha, beta, gamma values. This corresponded to a substantial improvement in detection performance where the true positive rate increased for the same average false positives per image.

Improved Seam-Line Searching Algorithm for UAV Image Mosaic with Optical Flow.

PubMed

Zhang, Weilong; Guo, Bingxuan; Li, Ming; Liao, Xuan; Li, Wenzhuo

2018-04-16

Ghosting and seams are two major challenges in creating unmanned aerial vehicle (UAV) image mosaic. In response to these problems, this paper proposes an improved method for UAV image seam-line searching. First, an image matching algorithm is used to extract and match the features of adjacent images, so that they can be transformed into the same coordinate system. Then, the gray scale difference, the gradient minimum, and the optical flow value of pixels in adjacent image overlapped area in a neighborhood are calculated, which can be applied to creating an energy function for seam-line searching. Based on that, an improved dynamic programming algorithm is proposed to search the optimal seam-lines to complete the UAV image mosaic. This algorithm adopts a more adaptive energy aggregation and traversal strategy, which can find a more ideal splicing path for adjacent UAV images and avoid the ground objects better. The experimental results show that the proposed method can effectively solve the problems of ghosting and seams in the panoramic UAV images.

Improved method to fully compensate the spatial phase nonuniformity of LCoS devices with a Fizeau interferometer.

PubMed

Lu, Qiang; Sheng, Lei; Zeng, Fei; Gao, Shijie; Qiao, Yanfeng

2016-10-01

Liquid crystal on silicon (LCoS) devices usually show spatial phase nonuniformity (SPNU) in applications of phase modulation, which comprises the phase retardance nonuniformity (PRNU) as a function of the applied voltage and inherent wavefront distortion (WFD) introduced by the device itself. We propose a multipoint calibration method utilizing a Fizeau interferometer to compensate SPNU of the device. Calibration of PRNU is realized by defining a grid of 3×6 cells onto the aperture and then calculating phase retardance of each cell versus a gradient gray pattern. With designing an adjusted gray pattern calculated by the calibrated multipoint phase retardance function, compensation of inherent WFD is achieved. The peak-to-valley (PV) value of the residual WFD compensated by the multipoint calibration method is significantly reduced from 2.5λ to 0.140λ, while the PV value of the residual WFD after global calibration is reduced to 0.364λ. Experimental results of the generated finite-energy 2D Airy beams in Fourier space demonstrate the effectiveness of this multipoint calibration method.

MToS: A Tree of Shapes for Multivariate Images.

PubMed

Carlinet, Edwin; Géraud, Thierry

2015-12-01

The topographic map of a gray-level image, also called tree of shapes, provides a high-level hierarchical representation of the image contents. This representation, invariant to contrast changes and to contrast inversion, has been proved very useful to achieve many image processing and pattern recognition tasks. Its definition relies on the total ordering of pixel values, so this representation does not exist for color images, or more generally, multivariate images. Common workarounds, such as marginal processing, or imposing a total order on data, are not satisfactory and yield many problems. This paper presents a method to build a tree-based representation of multivariate images, which features marginally the same properties of the gray-level tree of shapes. Briefly put, we do not impose an arbitrary ordering on values, but we only rely on the inclusion relationship between shapes in the image definition domain. The interest of having a contrast invariant and self-dual representation of multivariate image is illustrated through several applications (filtering, segmentation, and object recognition) on different types of data: color natural images, document images, satellite hyperspectral imaging, multimodal medical imaging, and videos.

Group-focused morality is associated with limited conflict detection and resolution capacity: Neuroanatomical evidence.

PubMed

Nash, Kyle; Baumgartner, Thomas; Knoch, Daria

2017-02-01

Group-focused moral foundations (GMFs) - moral values that help protect the group's welfare - sharply divide conservatives from liberals and religiously devout from non-believers. However, there is little evidence about what drives this divide. Moral foundations theory and the model of motivated social cognition both associate group-focused moral foundations with differences in conflict detection and resolution capacity, but in opposing directions. Individual differences in conflict detection and resolution implicate specific neuroanatomical differences. Examining neuroanatomy thus affords an objective and non-biased opportunity to contrast these influential theories. Here, we report that increased adherence to group-focused moral foundations was strongly associated (whole-brain corrected) with reduced gray matter volume in key regions of the conflict detection and resolution system (anterior cingulate cortex and lateral prefrontal cortex). Because reduced gray matter is reliably associated with reduced neural and cognitive capacity, these findings support the idea outlined in the model of motivated social cognition that belief in group-focused moral values is associated with reduced conflict detection and resolution capacity. Copyright © 2017 Elsevier B.V. All rights reserved.

A novel interpolation approach for the generation of 3D-geometric digital bone models from image stacks

PubMed Central

Mittag, U.; Kriechbaumer, A.; Rittweger, J.

2017-01-01

The authors propose a new 3D interpolation algorithm for the generation of digital geometric 3D-models of bones from existing image stacks obtained by peripheral Quantitative Computed Tomography (pQCT) or Magnetic Resonance Imaging (MRI). The technique is based on the interpolation of radial gray value profiles of the pQCT cross sections. The method has been validated by using an ex-vivo human tibia and by comparing interpolated pQCT images with images from scans taken at the same position. A diversity index of <0.4 (1 meaning maximal diversity) even for the structurally complex region of the epiphysis, along with the good agreement of mineral-density-weighted cross-sectional moment of inertia (CSMI), demonstrate the high quality of our interpolation approach. Thus the authors demonstrate that this interpolation scheme can substantially improve the generation of 3D models from sparse scan sets, not only with respect to the outer shape but also with respect to the internal gray-value derived material property distribution. PMID:28574415

GRAY: a program to calculate gray-body radiation heat-transfer view factors from black-body view factors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wong, R. L.

1976-06-14

Program GRAY is written to perform the matrix manipulations necessary to convert black-body radiation heat-transfer view factors to gray-body view factors as required by thermal analyzer codes. The black-body view factors contain only geometric relationships. Program GRAY allows the effects of multiple gray-body reflections to be included. The resulting effective gray-body factors can then be used with the corresponding fourth-power temperature differences to obtain the net radiative heat flux. The program is written to accept a matrix input or the card image output generated by the black-body view factor program CNVUFAC. The resulting card image output generated by GRAY ismore » in a form usable by the TRUMP thermal analyzer.« less

MQ-1C Gray Eagle Unmanned Aircraft System (MQ-1C Gray Eagle)

DTIC Science & Technology

2015-12-01

Selected Acquisition Report ( SAR ) RCS: DD-A&T(Q&A)823-420 MQ-1C Gray Eagle Unmanned Aircraft System (MQ-1C Gray Eagle) As of FY 2017 President’s...Budget Defense Acquisition Management Information Retrieval (DAMIR) March 21, 2016 17:33:19 UNCLASSIFIED MQ-1C Gray Eagle December 2015 SAR March 21...Gray Eagle December 2015 SAR March 21, 2016 17:33:19 UNCLASSIFIED 3 PB - President’s Budget PE - Program Element PEO - Program Executive Officer PM

Effect of Contrasting Trophic Conditions on the Priming Effect in Gray Forest Soils

NASA Astrophysics Data System (ADS)

Zhuravleva, A. I.; Alifanov, V. M.; Blagodatskaya, E. V.

2018-02-01

Priming effects initiated by the addition of 14C glucose have been compared for humus horizons of soils existing under continuous input of fresh organic substrates and for buried soil horizons, in which entering of organic matter has been essentially limited. The effect of microrelief on the manifestation of priming effect in the humus horizons of gray forest soil on microhigh and in microlow has been estimated. Humus horizon in soils on microhigh, not activated by glucose, produced two times more CO2 in comparison with soils of microlow. However, the introduction of glucose canceled the effect of microrelief on CO2 emission. The intensity of absolute priming effect correlated with the Corg pool, initial microbial biomass, and enzyme activity, decreasing from humus horizons to the buried ones, and did not depend on microrelief. The effect of microrelief was observed, when assessing the priming effect relative to control (soil not activated by glucose): the value of relative priming effect was 1.5 times greater in A horizon of gray forest soil in microlow in comparison with that on microhigh being the result of increasing activity of enzymes.

Sensitivity of U.S. summer precipitation to model resolution and convective parameterizations across gray zone resolutions

NASA Astrophysics Data System (ADS)

Gao, Yang; Leung, L. Ruby; Zhao, Chun; Hagos, Samson

2017-03-01

Simulating summer precipitation is a significant challenge for climate models that rely on cumulus parameterizations to represent moist convection processes. Motivated by recent advances in computing that support very high-resolution modeling, this study aims to systematically evaluate the effects of model resolution and convective parameterizations across the gray zone resolutions. Simulations using the Weather Research and Forecasting model were conducted at grid spacings of 36 km, 12 km, and 4 km for two summers over the conterminous U.S. The convection-permitting simulations at 4 km grid spacing are most skillful in reproducing the observed precipitation spatial distributions and diurnal variability. Notable differences are found between simulations with the traditional Kain-Fritsch (KF) and the scale-aware Grell-Freitas (GF) convection schemes, with the latter more skillful in capturing the nocturnal timing in the Great Plains and North American monsoon regions. The GF scheme also simulates a smoother transition from convective to large-scale precipitation as resolution increases, resulting in reduced sensitivity to model resolution compared to the KF scheme. Nonhydrostatic dynamics has a positive impact on precipitation over complex terrain even at 12 km and 36 km grid spacings. With nudging of the winds toward observations, we show that the conspicuous warm biases in the Southern Great Plains are related to precipitation biases induced by large-scale circulation biases, which are insensitive to model resolution. Overall, notable improvements in simulating summer rainfall and its diurnal variability through convection-permitting modeling and scale-aware parameterizations suggest promising venues for improving climate simulations of water cycle processes.

An investigation of the use of transmission ultrasound to measure acoustic attenuation changes in thermal therapy.

PubMed

Parmar, Neeta; Kolios, Michael C

2006-07-01

The potential of using a commercial ultrasound transmission imaging system to quantitatively monitor tissue attenuation changes after thermal therapy was investigated. The ultrasound transmission imaging system used, the AcoustoCam (Imperium Inc., MD) allows ultrasonic images to be captured using principles similar to that of a CCD-type camera that collects light. Ultrasound energy is focused onto a piezoelectric array by an acoustic lens system, creating a gray scale acoustic image. In this work, the pixel values from the acoustic images were assigned acoustic attenuation values by imaging polyacrylamide phantoms of varying known attenuation. After the calibration procedure, data from heated polyacrylamide/bovine serum albumin (BSA) based tissue-mimicking (TM) phantoms and porcine livers were acquired. Samples were heated in water at temperatures of 35, 45, 55, 65, and 75 degrees C for 1 h. Regions of interest were chosen in the images and acoustic attenuation values before and after heating were compared. An increase in ultrasound attenuation was found in phantoms containing BSA and in porcine liver. In the presence of BSA, attenuation in the TM phantom increased by a factor of 1.5, while without BSA no significant changes were observed. The attenuation of the porcine liver increased by up to a factor of 2.4, consistent with previously reported studies. The study demonstrates the feasibility of using a quantitative ultrasound transmission imaging system for monitoring thermal therapy.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paulus, Wilfred; Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor; Rahman, Irman Abdul

Lead-free solders are important material in nano and microelectronic surface mounting technology for various applications in bio medicine, environmental monitoring, spacecraft and satellite instrumentation. Nevertheless solder joint in radiation environment needs higher reliability and resistance to any damage caused by ionizing radiations. In this study a lead-free 99.0Sn0.3Ag0.7Cu wt.% (SAC) solder joint was developed and subjected to various doses of gamma radiation to investigate the effects of the ionizing radiation to micromechanical hardness of the solder. Averaged hardness of the SAC joint was obtained from nanoindentation test. The results show a relationship between hardness values of indentations and the incrementmore » of radiation dose. Highest mean hardness, 0.2290 ± 0.0270 GPa was calculated on solder joint which was exposed to 5 Gray dose of gamma radiation. This value indicates possible radiation hardening effect on irradiated solder. The hardness gradually decreased to 0.1933 ± 0.0210 GPa and 0.1631 ± 0.0173 GPa when exposed to doses 50 and 500 gray respectively. These values are also lower than the hardness of non irradiated sample which was calculated as 0.2084 ± 0.0.3633 GPa indicating possible radiation damage and needs further related atomic dislocation study.« less

Intensity ratio to improve black hole assessment in multiple sclerosis.

PubMed

Adusumilli, Gautam; Trinkaus, Kathryn; Sun, Peng; Lancia, Samantha; Viox, Jeffrey D; Wen, Jie; Naismith, Robert T; Cross, Anne H

2018-01-01

Improved imaging methods are critical to assess neurodegeneration and remyelination in multiple sclerosis. Chronic hypointensities observed on T1-weighted brain MRI, "persistent black holes," reflect severe focal tissue damage. Present measures consist of determining persistent black holes numbers and volumes, but do not quantitate severity of individual lesions. Develop a method to differentiate black and gray holes and estimate the severity of individual multiple sclerosis lesions using standard magnetic resonance imaging. 38 multiple sclerosis patients contributed images. Intensities of lesions on T1-weighted scans were assessed relative to cerebrospinal fluid intensity using commercial software. Magnetization transfer imaging, diffusion tensor imaging and clinical testing were performed to assess associations with T1w intensity-based measures. Intensity-based assessments of T1w hypointensities were reproducible and achieved > 90% concordance with expert rater determinations of "black" and "gray" holes. Intensity ratio values correlated with magnetization transfer ratios (R = 0.473) and diffusion tensor imaging metrics (R values ranging from 0.283 to -0.531) that have been associated with demyelination and axon loss. Intensity ratio values incorporated into T1w hypointensity volumes correlated with clinical measures of cognition. This method of determining the degree of hypointensity within multiple sclerosis lesions can add information to conventional imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of photodynamic therapy on short-wavelength fundus autofluorescence in eyes with acute central serous chorioretinopathy.

PubMed

Hagen, Stefan; Ansari-Shahrezaei, Siamak; Smretschnig, Eva; Glittenberg, Carl; Krebs, Ilse; Steiner, Irene; Binder, Susanne

2015-02-01

To evaluate short-wavelength FAF as a parameter of retinal pigment epithelium function in eyes with acute symptomatic central serous chorioretinopathy after indocyanine green angiography-guided verteporfin photodynamic therapy with half-fluence rate. A retrospective review over a period of 1 year of short-wavelength FAF images of 15 consecutive patients treated with half-fluence rate (25 J/cm) indocyanine green angiography-guided verteporfin photodynamic therapy due to acute symptomatic central serous chorioretinopathy was performed. Short-wavelength (488 nm) FAF gray values were evaluated with a confocal scanning laser ophthalmoscope at a 350-μm diameter and a 1,200-μm diameter circle centered on the fovea. The change in short-wavelength (488 nm) FAF gray values for the 2 circles was evaluated by calculating the differences of respective values between the first month after treatment and the 3, 6, 9, and 12 months follow-up. Mean differences (95% confidence interval) in short-wavelength (488 nm) FAF gray values of the 350-μm and 1,200-μm diameter circle between the 1-month and the 3-month (n = 15) follow-up were -0.03 (-0.11 to 0.05) (P = 0.46) and -0.03 (-0.17 to 0.10) (P = 0.6). Respective differences between the 1 month and the 6 (n = 15), 9 (n = 14), and 12 months (n = 13) of follow-up were -0.03 (-0.11 to 0.05) (P = 0.42) and -0.04 (-0.16 to 0.08) (P = 0.5); -0.05 (-0.12 to 0.03) (P = 0.23) and -0.06 (-0.18 to 0.07) (P = 0.33); -0.03 (-0.12 to 0.07) (P = 0.57) and -0.07 (-0.20 to 0.05) (P = 0.22). Half-fluence rate (25 J/cm) indocyanine green angiography-guided verteporfin photodynamic therapy did not significantly affect short-wavelength FAF at a 350-μm diameter and a 1,200-μm diameter circle in eyes with resolved acute symptomatic central serous chorioretinopathy throughout 12 months of follow-up.

Reproducibility of sonographic measurement of thickness and echogenicity of the plantar fascia.

PubMed

Cheng, Ju-Wen; Tsai, Wen-Chung; Yu, Tung-Yang; Huang, Kuo-Yao

2012-01-01

To evaluate the intra- and interrater reliability of ultrasonographic measurements of the thickness and echogenicity of the plantar fascia. Eleven patients (20 feet), who complained of inferior heel pain, and 26 volunteers (52 feet) were enrolled. Two sonographers independently imaged the plantar fascia in both longitudinal and transverse planes. Volunteers were assessed twice to evaluate intrarater reliability. Quantitative evaluation of the echogenicity of the plantar fascia was performed by measuring the mean gray level of the region of interest using Digital Imaging and Communications in Medicine viewer software. Sonographic evaluation of the thickness of the plantar fascia showed high reliability. Sonographic evaluations of the presence or absence of hypoechoic change in the plantar fascia showed surprisingly low agreement. The reliability of gray-scale evaluations appears to be much better than subjective judgments in the evaluation of echogenicity. Transverse scanning did not show any advantage in sonographic evaluation of the plantar fascia. The reliability of sonographic examination of the thickness of the plantar fascia is high. Mean gray-level analysis of quantitative sonography can be used for the evaluation of echogenicity, which could reduce discrepancies in the interpretation of echogenicity by different sonographers. Longitudinal instead of transverse scanning is recommended for imaging the plantar fascia. Copyright © 2011 Wiley Periodicals, Inc.

Rethinking people’s conceptions of mental life

PubMed Central

Weisman, Kara; Dweck, Carol S.; Markman, Ellen M.

2017-01-01

How do people make sense of the emotions, sensations, and cognitive abilities that make up mental life? Pioneering work on the dimensions of mind perception has been interpreted as evidence that people consider mental life to have two core components—experience (e.g., hunger, joy) and agency (e.g., planning, self-control) [Gray HM, et al. (2007) Science 315:619]. We argue that this conclusion is premature: The experience–agency framework may capture people’s understanding of the differences among different beings (e.g., dogs, humans, robots, God) but not how people parse mental life itself. Inspired by Gray et al.’s bottom-up approach, we conducted four large-scale studies designed to assess people’s conceptions of mental life more directly. This led to the discovery of an organization that differs strikingly from the experience–agency framework: Instead of a broad distinction between experience and agency, our studies consistently revealed three fundamental components of mental life—suites of capacities related to the body, the heart, and the mind—with each component encompassing related aspects of both experience and agency. This body–heart–mind framework distinguishes itself from Gray et al.’s experience–agency framework by its clear and importantly different implications for dehumanization, moral reasoning, and other important social phenomena. PMID:29073059

Automated brain tumor segmentation in magnetic resonance imaging based on sliding-window technique and symmetry analysis.

PubMed

Lian, Yanyun; Song, Zhijian

2014-01-01

Brain tumor segmentation from magnetic resonance imaging (MRI) is an important step toward surgical planning, treatment planning, monitoring of therapy. However, manual tumor segmentation commonly used in clinic is time-consuming and challenging, and none of the existed automated methods are highly robust, reliable and efficient in clinic application. An accurate and automated tumor segmentation method has been developed for brain tumor segmentation that will provide reproducible and objective results close to manual segmentation results. Based on the symmetry of human brain, we employed sliding-window technique and correlation coefficient to locate the tumor position. At first, the image to be segmented was normalized, rotated, denoised, and bisected. Subsequently, through vertical and horizontal sliding-windows technique in turn, that is, two windows in the left and the right part of brain image moving simultaneously pixel by pixel in two parts of brain image, along with calculating of correlation coefficient of two windows, two windows with minimal correlation coefficient were obtained, and the window with bigger average gray value is the location of tumor and the pixel with biggest gray value is the locating point of tumor. At last, the segmentation threshold was decided by the average gray value of the pixels in the square with center at the locating point and 10 pixels of side length, and threshold segmentation and morphological operations were used to acquire the final tumor region. The method was evaluated on 3D FSPGR brain MR images of 10 patients. As a result, the average ratio of correct location was 93.4% for 575 slices containing tumor, the average Dice similarity coefficient was 0.77 for one scan, and the average time spent on one scan was 40 seconds. An fully automated, simple and efficient segmentation method for brain tumor is proposed and promising for future clinic use. Correlation coefficient is a new and effective feature for tumor location.

a Novel Ihs-Ga Fusion Method Based on Enhancement Vegetated Area

NASA Astrophysics Data System (ADS)

Niazi, S.; Mokhtarzade, M.; Saeedzadeh, F.

2015-12-01

Pan sharpening methods aim to produce a more informative image containing the positive aspects of both source images. However, the pan sharpening process usually introduces some spectral and spatial distortions in the resulting fused image. The amount of these distortions varies highly depending on the pan sharpening technique as well as the type of data. Among the existing pan sharpening methods, the Intensity-Hue-Saturation (IHS) technique is the most widely used for its efficiency and high spatial resolution. When the IHS method is used for IKONOS or QuickBird imagery, there is a significant color distortion which is mainly due to the wavelengths range of the panchromatic image. Regarding the fact that in the green vegetated regions panchromatic gray values are much larger than the gray values of intensity image. A novel method is proposed which spatially adjusts the intensity image in vegetated areas. To do so the normalized difference vegetation index (NDVI) is used to identify vegetation areas where the green band is enhanced according to the red and NIR bands. In this way an intensity image is obtained in which the gray values are comparable to the panchromatic image. Beside the genetic optimization algorithm is used to find the optimum weight parameters in order to gain the best intensity image. Visual and statistical analysis proved the efficiency of the proposed method as it significantly improved the fusion quality in comparison to conventional IHS technique. The accuracy of the proposed pan sharpening technique was also evaluated in terms of different spatial and spectral metrics. In this study, 7 metrics (Correlation Coefficient, ERGAS, RASE, RMSE, SAM, SID and Spatial Coefficient) have been used in order to determine the quality of the pan-sharpened images. Experiments were conducted on two different data sets obtained by two different imaging sensors, IKONOS and QuickBird. The result of this showed that the evaluation metrics are more promising for our fused image in comparison to other pan sharpening methods.

Intraocular pressure in the smallest primate aging model: the gray mouse lemur.

PubMed

Dubicanac, Marko; Joly, Marine; Strüve, Julia; Nolte, Ingo; Mestre-Francés, Nadine; Verdier, Jean-Michel; Zimmermann, Elke

2018-05-01

The aim of this study was to assess the practicability of common tonometers used in veterinary medicine for rapid intraocular pressure (IOP) screening, to calibrate IOP values gained by the tonometers, and to define a reference IOP value for the healthy eye in a new primate model for aging research, the gray mouse lemur. TonoVet ® and the TonoPen ™ measurements were calibrated manometrically in healthy enucleated eyes of mouse lemurs euthanized for veterinary reasons. For comparison of the practicability of both tonometers as a rapid IOP assessment tool for living mouse lemurs, the IOP of 24 eyes of 12 animals held in the hand was measured. To define a standard reference value for IOP in mouse lemurs, 258 healthy animals were measured using the TonoVet ® . Intraocular pressure measurements for the TonoVet ® can be corrected using the formula: y = 0.981 + (1.962*TonoVet ® value), and those for the TonoPen ™ using that of y = 5.38 + (1.426*TonoPen ™ value). The calibrated IOP for a healthy mouse lemur eye was 20.3 ± 2.8 mmHg. The TonoVet ® showed advantages in practicability, for example, small corneal contact area, short and painless corneal contact, shortened total time spent on investigation, as well as the more accurate measured values. IOP measurements of healthy mouse lemur eyes were not affected by age, sex, eye side, or colony. Tonometry using TonoVet ® is the more practicable assessment tool for IOP measurement of the tiny eyes of living mouse lemurs. Pathological deviations can be identified based on the described reference value. © 2016 American College of Veterinary Ophthalmologists.

Image Understanding. Proceedings of a Workshop (11th) Held at College Park, Maryland, April 30, 1980

DTIC Science & Technology

1980-04-30

space nearest connected pairs. The new change in disparity is evaluated, and tested to see whether it lies in the |^ - ff, i? + o\\ inter - val. When no...property values such as gray level and " busyness ". Figure 3a shows a house picture containing five principal types of regions—sky, grass, bushes...pixe1 based on those of its neighbors; see Figure 3c Similar Improvement is obtained when the busyness values are Iteratively smoothed, e.g. by

The Reduction of Ventrolateral Prefrontal Cortex Gray Matter Volume Correlates with Loss of Economic Rationality in Aging.

PubMed

Chung, Hui-Kuan; Tymula, Agnieszka; Glimcher, Paul

2017-12-06

The population of people above 65 years old continues to grow, and there is mounting evidence that as humans age they are more likely to make errors. However, the specific effect of neuroanatomical aging on the efficiency of economic decision-making is poorly understood. We used whole-brain voxel-based morphometry analysis to determine where reduction of gray matter volume in healthy female and male adults over the age of 65 years correlates with a classic measure of economic irrationality: violations of the Generalized Axiom of Revealed Preference. All participants were functionally normal with Mini-Mental State Examination scores ranging between 26 and 30. While our elders showed the previously reported decline in rationality compared with younger subjects, chronological age per se did not correlate with rationality measures within our population of elders. Instead, reduction of gray matter density in ventrolateral prefrontal cortex correlates tightly with irrational behavior. Interestingly, using a large fMRI sample and meta-analytic tool with Neurosynth, we found that this brain area shows strong coactivation patterns with nearly all of the value-associated regions identified in previous studies. These findings point toward a neuroanatomic locus for economic rationality in the aging brain and highlight the importance of understanding both anatomy and function in the study of aging, cognition, and decision-making. SIGNIFICANCE STATEMENT Age is a crucial factor in decision-making, with older individuals making more errors in choices. Using whole-brain voxel-based morphometry analysis, we found that reduction of gray matter density in ventrolateral prefrontal cortex correlates with economic irrationality: reduced gray matter volume in this area correlates with the frequency and severity of violations of the Generalized Axiom of Revealed Preference. Furthermore, this brain area strongly coactivates with other reward-associated regions identified with Neurosynth. These findings point toward a role for neuroscientific discoveries in shaping long-standing economic views of decision-making. Copyright © 2017 the authors 0270-6474/17/3712068-10$15.00/0.

The Reduction of Ventrolateral Prefrontal Cortex Gray Matter Volume Correlates with Loss of Economic Rationality in Aging

PubMed Central

Tymula, Agnieszka

2017-01-01

The population of people above 65 years old continues to grow, and there is mounting evidence that as humans age they are more likely to make errors. However, the specific effect of neuroanatomical aging on the efficiency of economic decision-making is poorly understood. We used whole-brain voxel-based morphometry analysis to determine where reduction of gray matter volume in healthy female and male adults over the age of 65 years correlates with a classic measure of economic irrationality: violations of the Generalized Axiom of Revealed Preference. All participants were functionally normal with Mini-Mental State Examination scores ranging between 26 and 30. While our elders showed the previously reported decline in rationality compared with younger subjects, chronological age per se did not correlate with rationality measures within our population of elders. Instead, reduction of gray matter density in ventrolateral prefrontal cortex correlates tightly with irrational behavior. Interestingly, using a large fMRI sample and meta-analytic tool with Neurosynth, we found that this brain area shows strong coactivation patterns with nearly all of the value-associated regions identified in previous studies. These findings point toward a neuroanatomic locus for economic rationality in the aging brain and highlight the importance of understanding both anatomy and function in the study of aging, cognition, and decision-making. SIGNIFICANCE STATEMENT Age is a crucial factor in decision-making, with older individuals making more errors in choices. Using whole-brain voxel-based morphometry analysis, we found that reduction of gray matter density in ventrolateral prefrontal cortex correlates with economic irrationality: reduced gray matter volume in this area correlates with the frequency and severity of violations of the Generalized Axiom of Revealed Preference. Furthermore, this brain area strongly coactivates with other reward-associated regions identified with Neurosynth. These findings point toward a role for neuroscientific discoveries in shaping long-standing economic views of decision-making. PMID:28982708

Behavioral Response of Reef Fish and Green Sea Turtles to Midfrequency Sonar.

PubMed

Watwood, Stephanie L; Iafrate, Joseph D; Reyier, Eric A; Redfoot, William E

2016-01-01

There is growing concern over the potential effects of high-intensity sonar on wild fish populations and commercial fisheries. Acoustic telemetry was employed to measure the movements of free-ranging reef fish and sea turtles in Port Canaveral, FL, in response to routine submarine sonar testing. Twenty-five sheepshead (Archosargus probatocephalus), 28 gray snapper (Lutjanus griseus), and 29 green sea turtles (Chelonia mydas) were tagged, with movements monitored for a period of up to 4 months using an array of passive acoustic receivers. Baseline residency was examined for fish and sea turtles before, during, and after the test event. No mortality of tagged fish or sea turtles was evident from the sonar test event. There was a significant increase in the daily residency index for both sheepshead and gray snapper at the testing wharf subsequent to the event. No broad-scale movement from the study site was observed during or immediately after the test.

Assessing app quality through expert peer review: a case study from the gray matters study.

PubMed

Hartin, Phillip J; Cleland, Ian; Nugent, Chris D; McClean, Sally I; Tschanz, JoAnn; Clark, Christine; Norton, Maria C

2016-08-01

Health apps focused on inciting behavior change are becoming increasingly popular. Nevertheless, many lack underlying evidence base, scientific credibility and have limited clinical effectiveness. It is therefore important that apps are well-informed, scientifically credible, peer reviewed and evidence based. This paper presents the use of the Mobile App Rating Scale (MARS) to assess the quality of the Grey Matters app, a cross platform app to deliver health education material and track behavior change across multi-domains with the aim of reducing the risk of developing Alzheimer's disease. The Gray Matters app shows promising results following reviews from 5 Expert raters, achieving a mean overall MARS score of 4.45 ± 0.14. Future work will involve undertaking of a detailed content analysis of behavior change apps to identify common themes and features which may lead to the successful facilitation of sustained behavior change.

Gray Matter Increase in Motor Cortex in Pediatric ADHD: A Voxel-Based Morphometry Study.

PubMed

Sutcubasi Kaya, Bernis; Metin, Baris; Tas, Zeynep Cubukcuoglu; Buyukaslan, Ayse; Soysal, Aysegul; Hatiloglu, Deniz; Tarhan, Nevzat

2018-05-01

Several studies report that ADHD is associated with reduced gray matter (GM), whereas others report no differences in GM volume between ADHD patients and controls, and some even report more GM volume in individuals with ADHD. These conflicting findings suggest that reduced GM is not a universal finding in ADHD, and that more research is needed to delineate with greater accuracy the range of GM alterations. The present study aimed to identify GM alterations in ADHD using pediatric templates. 19 drug-naïve ADHD patients and 18 controls, all aged 7 to 14 years, were scanned using magnetic resonance imaging. Relative to the controls, the ADHD patients had more GM, predominantly in the precentral and supplementary motor areas. Moreover, there were positive correlations between GM volume in these areas and ADHD scale scores. The clinical and pathophysiological significance of increased GM in the motor areas remains to be elucidated by additional research.

Correlations among Brain Gray Matter Volumes, Age, Gender, and Hemisphere in Healthy Individuals

PubMed Central

Taki, Yasuyuki; Thyreau, Benjamin; Kinomura, Shigeo; Sato, Kazunori; Goto, Ryoi; Kawashima, Ryuta; Fukuda, Hiroshi

2011-01-01

To determine the relationship between age and gray matter structure and how interactions between gender and hemisphere impact this relationship, we examined correlations between global or regional gray matter volume and age, including interactions of gender and hemisphere, using a general linear model with voxel-based and region-of-interest analyses. Brain magnetic resonance images were collected from 1460 healthy individuals aged 20–69 years; the images were linearly normalized and segmented and restored to native space for analysis of global gray matter volume. Linearly normalized images were then non-linearly normalized and smoothed for analysis of regional gray matter volume. Analysis of global gray matter volume revealed a significant negative correlation between gray matter ratio (gray matter volume divided by intracranial volume) and age in both genders, and a significant interaction effect of age × gender on the gray matter ratio. In analyzing regional gray matter volume, the gray matter volume of all regions showed significant main effects of age, and most regions, with the exception of several including the inferior parietal lobule, showed a significant age × gender interaction. Additionally, the inferior temporal gyrus showed a significant age × gender × hemisphere interaction. No regional volumes showed significant age × hemisphere interactions. Our study may contribute to clarifying the mechanism(s) of normal brain aging in each brain region. PMID:21818377

Three-Component Integrated Ultrathin Organic Photosensors for Plastic Optoelectronics.

PubMed

Wang, Hanlin; Liu, Hongtao; Zhao, Qiang; Cheng, Cheng; Hu, Wenping; Liu, Yunqi

2016-01-27

By three-component integration, an integrated organic photosensor is presented using common organic dyes as building blocks. Gray-scale photosensing and signal amplification are achieved in the device within a wide range of light intensities. Moreover, with ultrathin film techniques, 470 nm thick devices are realized and continue to work when harshly bent. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multiport Multiplex Program

DTIC Science & Technology

1975-02-01

UNCLASSIFIED AD NUMBER LIMITATION CHANGES TO: FROM: AUTHORITY THIS PAGE IS UNCLASSIFIED ADB013811 Approved for public release; distribution is...of Changing Sampling Frequency and Bits/Sample 13 Image Coding Methods 63 Basic Dual-Mode Coder Code Assignment 73 Oversampled Dual...results from the threshold at which a 1 bit will oe trans- mitted. The threshold corresponds to a finite change on the gray scale or resolution of the

Manufacturing considerations for AMLCD cockpit displays

NASA Astrophysics Data System (ADS)

Luo, Fang-Chen

1995-06-01

AMLCD cockpit displays need to meet more stringent requirements compared with AMLCD commercial displays in areas such as environmental conditions, optical performance and device reliability. Special considerations are required for the manufacturing of AMLCD cockpit displays in each process step to address these issues. Some examples are: UV stable polarizers, wide-temperature LC material, strong LC glue seal, ESS test system, gray scale voltage EEPROM, etc.

Evaluation of factors affecting resolution of shallow water bottom features

NASA Technical Reports Server (NTRS)

Mason, C. C.; Norris, D. R.; Browne, I. D.

1972-01-01

To ensure good aerial photography, the effects that factors such as submergence depth, sun angle, film and filter type, exposure, aircraft altitude, and polarization have on the photographic resolution of an underwater object must be determined. Various subjects were photographed, such as the deck of a small submersible, colored and gray scale panels, and natural bottom features. No underwater resolution target was used.

The Effect of Climate Variability on Gray Whales (Eschrichtius robustus) within Their Wintering Areas

PubMed Central

Salvadeo, Christian J.; Gómez-Gallardo U., Alejandro; Nájera-Caballero, Mauricio; Urbán-Ramirez, Jorge; Lluch-Belda, Daniel

2015-01-01

The environmental conditions of the breeding and feeding grounds of the gray whale (Eschrichtius robustus) fluctuates at inter-annual scales in response to regional and basin climate patterns. Thus, the goals of this study were to assess if there are any relationships between summer sea ice on their feeding ground and counts of gray whale mother-calf (MC) pairs at Ojo de Liebre Lagoon (OLL); and if El Niño Southern Oscillation (ENSO) influences the winter distribution of gray whales MC pairs in the three primary breeding lagoons of OLL, San Ignacio Lagoon (SIL) and Santo Domingo Channel north of Bahia Magdalena (SDCh). Maximum February counts of MC pairs were compared with the length of the open-water season at the Bering Sea during the previous year. Then, an ENSO index and sea surface temperature anomalies outside the primary lagoons was compared with the maximum February counts of MC pairs at these lagoons. Results showed that maximum counts of MC pairs in OLL correlates with sea ice conditions in their feeding grounds from the previous feeding season, and this relationship can be attributed to changes in nutritive condition of females. ENSO-related variability influences distribution of MC pairs in the southern area of SDCh during the warm 1998 El Niño and cold 1999 La Niña. This supports the hypothesis that changes in the whales’ distribution related to sea temperature occurs to reduce thermal-stress and optimize energy utilization for newborn whales. Although this last conclusion should be considered in view of the limited data available from all the whales’ wintering locations in all the years considered. PMID:26309028

Evidence for West Nile virus spillover into the squirrel population in Atlanta, Georgia.

PubMed

Bisanzio, Donal; McMillan, Joseph R; Barreto, Josafá Gonçalves; Blitvich, Bradley J; Mead, Daniel G; O'Connor, Josh; Kitron, Uriel

2015-05-01

In the United States, spillover of West Nile virus (WNV) into wild mammal populations has been reported since the introduction of the virus into the New World in 1999. Eastern gray squirrels (Sciurus carolinensis) exhibit a high seroprevalence for WNV in urban settings where high virus circulation and human spillover have been reported. In Atlanta, Georgia, human cases of WNV are uncommon despite high infection rates in birds and mosquitoes. In this study, we evaluated WNV exposure of eastern gray squirrels in a WNV hot spot in Atlanta. Gray squirrels were live-trapped in Grant Park, Atlanta, during July-October, 2012, and a census was conducted to estimate squirrel density in the study site. Sera from trapped animals were tested for circulating virus-by-virus isolation in cell culture and for WNV-specific antibodies by enzyme-linked immunosorbent assay and plaque reduction neutralization test. Mosquitoes were collected at the same location and tested for virus isolation. Among the 69 collected squirrels, 25 (36.2%) tested positive for WNV antibodies, although none were viremic. Seroprevalence was lower in juveniles (18.8%) than in adults (37.5%), but this difference was not statistically significant. Gender and squirrel density had no effect on seroprevalence. Seasonality of squirrel seroprevalence and of mosquito infection were significantly associated, both peaking in August. No difference in squirrel exposure was detected across the collection sites. We report a high degree of WNV exposure in squirrels in Grant Park that was correlated with seasonality of mosquito infection. The detection of antibodies in juveniles suggests that circulation of WNV in the surveyed population is ongoing. Eastern gray squirrels may be suitable indicators for virus amplification and for risk of human spillover on a local scale in urban settings.

The Effect of Climate Variability on Gray Whales (Eschrichtius robustus) within Their Wintering Areas.

PubMed

Salvadeo, Christian J; Gómez-Gallardo U, Alejandro; Nájera-Caballero, Mauricio; Urbán-Ramirez, Jorge; Lluch-Belda, Daniel

2015-01-01

The environmental conditions of the breeding and feeding grounds of the gray whale (Eschrichtius robustus) fluctuates at inter-annual scales in response to regional and basin climate patterns. Thus, the goals of this study were to assess if there are any relationships between summer sea ice on their feeding ground and counts of gray whale mother-calf (MC) pairs at Ojo de Liebre Lagoon (OLL); and if El Niño Southern Oscillation (ENSO) influences the winter distribution of gray whales MC pairs in the three primary breeding lagoons of OLL, San Ignacio Lagoon (SIL) and Santo Domingo Channel north of Bahia Magdalena (SDCh). Maximum February counts of MC pairs were compared with the length of the open-water season at the Bering Sea during the previous year. Then, an ENSO index and sea surface temperature anomalies outside the primary lagoons was compared with the maximum February counts of MC pairs at these lagoons. Results showed that maximum counts of MC pairs in OLL correlates with sea ice conditions in their feeding grounds from the previous feeding season, and this relationship can be attributed to changes in nutritive condition of females. ENSO-related variability influences distribution of MC pairs in the southern area of SDCh during the warm 1998 El Niño and cold 1999 La Niña. This supports the hypothesis that changes in the whales' distribution related to sea temperature occurs to reduce thermal-stress and optimize energy utilization for newborn whales. Although this last conclusion should be considered in view of the limited data available from all the whales' wintering locations in all the years considered.

Gray-Box Approach for Thermal Modelling of Buildings for Applications in District Heating and Cooling Networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saurav, Kumar; Chandan, Vikas

District-heating-and-cooling (DHC) systems are a proven energy solution that has been deployed for many years in a growing number of urban areas worldwide. They comprise a variety of technologies that seek to develop synergies between the production and supply of heat, cooling, domestic hot water and electricity. Although the benefits of DHC systems are significant and have been widely acclaimed, yet the full potential of modern DHC systems remains largely untapped. There are several opportunities for development of energy efficient DHC systems, which will enable the effective exploitation of alternative renewable resources, waste heat recovery, etc., in order to increasemore » the overall efficiency and facilitate the transition towards the next generation of DHC systems. This motivated the need for modelling these complex systems. Large-scale modelling of DHC-networks is challenging, as it has several components such as buildings, pipes, valves, heating source, etc., interacting with each other. In this paper, we focus on building modelling. In particular, we present a gray-box methodology for thermal modelling of buildings. Gray-box modelling is a hybrid of data driven and physics based models where, coefficients of the equations from physics based models are learned using data. This approach allows us to capture the dynamics of the buildings more effectively as compared to pure data driven approach. Additionally, this approach results in a simpler models as compared to pure physics based models. We first develop the individual components of the building such as temperature evolution, flow controller, etc. These individual models are then integrated in to the complete gray-box model for the building. The model is validated using data collected from one of the buildings at Lule{\\aa}, a city on the coast of northern Sweden.« less

A novel method for retinal optic disc detection using bat meta-heuristic algorithm.

PubMed

Abdullah, Ahmad S; Özok, Yasa Ekşioğlu; Rahebi, Javad

2018-05-09

Normally, the optic disc detection of retinal images is useful during the treatment of glaucoma and diabetic retinopathy. In this paper, the novel preprocessing of a retinal image with a bat algorithm (BA) optimization is proposed to detect the optic disc of the retinal image. As the optic disk is a bright area and the vessels that emerge from it are dark, these facts lead to the selected segments being regions with a great diversity of intensity, which does not usually happen in pathological regions. First, in the preprocessing stage, the image is fully converted into a gray image using a gray scale conversion, and then morphological operations are implemented in order to remove dark elements such as blood vessels, from the images. In the next stage, a bat algorithm (BA) is used to find the optimum threshold value for the optic disc location. In order to improve the accuracy and to obtain the best result for the segmented optic disc, the ellipse fitting approach was used in the last stage to enhance and smooth the segmented optic disc boundary region. The ellipse fitting is carried out using the least square distance approach. The efficiency of the proposed method was tested on six publicly available datasets, MESSIDOR, DRIVE, DIARETDB1, DIARETDB0, STARE, and DRIONS-DB. The optic disc segmentation average overlaps and accuracy was in the range of 78.5-88.2% and 96.6-99.91% in these six databases. The optic disk of the retinal images was segmented in less than 2.1 s per image. The use of the proposed method improved the optic disc segmentation results for healthy and pathological retinal images in a low computation time. Graphical abstract ᅟ.

Quantitative Susceptibility Mapping in Parkinson's Disease.

PubMed

Langkammer, Christian; Pirpamer, Lukas; Seiler, Stephan; Deistung, Andreas; Schweser, Ferdinand; Franthal, Sebastian; Homayoon, Nina; Katschnig-Winter, Petra; Koegl-Wallner, Mariella; Pendl, Tamara; Stoegerer, Eva Maria; Wenzel, Karoline; Fazekas, Franz; Ropele, Stefan; Reichenbach, Jürgen Rainer; Schmidt, Reinhold; Schwingenschuh, Petra

2016-01-01

Quantitative susceptibility mapping (QSM) and R2* relaxation rate mapping have demonstrated increased iron deposition in the substantia nigra of patients with idiopathic Parkinson's disease (PD). However, the findings in other subcortical deep gray matter nuclei are converse and the sensitivity of QSM and R2* for morphological changes and their relation to clinical measures of disease severity has so far been investigated only sparsely. The local ethics committee approved this study and all subjects gave written informed consent. 66 patients with idiopathic Parkinson's disease and 58 control subjects underwent quantitative MRI at 3T. Susceptibility and R2* maps were reconstructed from a spoiled multi-echo 3D gradient echo sequence. Mean susceptibilities and R2* rates were measured in subcortical deep gray matter nuclei and compared between patients with PD and controls as well as related to clinical variables. Compared to control subjects, patients with PD had increased R2* values in the substantia nigra. QSM also showed higher susceptibilities in patients with PD in substantia nigra, in the nucleus ruber, thalamus, and globus pallidus. Magnetic susceptibility of several of these structures was correlated with the levodopa-equivalent daily dose (LEDD) and clinical markers of motor and non-motor disease severity (total MDS-UPDRS, MDS-UPDRS-I and II). Disease severity as assessed by the Hoehn & Yahr scale was correlated with magnetic susceptibility in the substantia nigra. The established finding of higher R2* rates in the substantia nigra was extended by QSM showing superior sensitivity for PD-related tissue changes in nigrostriatal dopaminergic pathways. QSM additionally reflected the levodopa-dosage and disease severity. These results suggest a more widespread pathologic involvement and QSM as a novel means for its investigation, more sensitive than current MRI techniques.

Characterization of the europium tetracycline complex as a biomarker for atherosclerosis

NASA Astrophysics Data System (ADS)

Courrol, Lilia C.; da Silva, Mônica N.; Sicchieri, Leticia B.

2016-04-01

Atherosclerosis is a narrowing of the arteries caused by an increase of atheromatous plaque: material formed by macrophage cells containing cholesterol and fatty acids, calcium and a variable amount of fibrous connective tissue. The elation between vulnerable plaques and cardiovascular events can be determined using plaque biomarkers. In this work, atherosclerotic plaques stained with different molar ratios of europium, in a potential plaque biomarker, europium tetracycline complex, were studied by fluorescence microscopy. The tetracycline antibiotic used was chlortetracycline. The growth of atherosclerotic plaque was followed during 60 days in New Zealand rabbits divided in two groups: an experimental group (EG), with nine animals and a control group (CG) with three animals. The animals in the EG received a diet with 1% of cholesterol and the animals of GC received a normal diet. The aortic arch of the animals with 60 days were cut in the vertical plane in 6 μm thick slices, which were mounted on glass slides and stained with hematoxylin an eosin and europium chlortetracycline complex (EuCTc). The fluorescence images were obtained exciting the EuCTc absorption band with a filter cube D (BP 355 - 425) and the emission was collected with a LP 470 suppression filter. Light intensity, detector gain and acquisition time were fixed for comparisons. The 20× magnified images were collected with 12 bit (or 4096 gray tones) resolution. The mean value of gray scale for each molar ratio of EuCTc was different, indicating that the complex interacts with the components of atherosclerotic plaque and the best molar ratio was 1.5 EuCTc. These results indicate the potential use of the EuCTc biomarker for atherosclerotic plaque characterization.

Using Correlative Properties of Neighboring Pixels to Enhance Contrast-to-Noise Ratio of Abnormal Hippocampus in Patients With Intractable Epilepsy and Mesial Temporal Sclerosis.

PubMed

Parsons, Matthew S; Sharma, Aseem; Hildebolt, Charles

2018-06-12

To test whether an image-processing algorithm can aid in visualization of mesial temporal sclerosis on magnetic resonance imaging by selectively increasing contrast-to-noise ratio (CNR) between abnormal hippocampus and normal brain. In this Institutional Review Board-approved and Health Insurance Portability and Accountability Act-compliant study, baseline coronal fluid-attenuated inversion recovery images of 18 adults (10 females, eight males; mean age 41.2 years) with proven mesial temporal sclerosis were processed using a custom algorithm to produce corresponding enhanced images. Average (Hmean) and maximum (Hmax) CNR for abnormal hippocampus were calculated relative to normal ipsilateral white matter. CNR values for normal gray matter (GM) were similarly calculated using ipsilateral cingulate gyrus as the internal control. To evaluate effect of image processing on visual conspicuity of hippocampal signal alteration, a neuroradiologist masked to the side of hippocampal abnormality rated signal intensity (SI) of hippocampi on baseline and enhanced images using a five-point scale (definitely abnormal to definitely normal). Differences in Hmean, Hmax, GM, and SI ratings for abnormal hippocampi on baseline and enhanced images were assessed for statistical significance. Both Hmean and Hmax were significantly higher in enhanced images as compared to baseline images (p < 0.0001 for both). There was no significant difference in the GM between baseline and enhanced images (p = 0.9375). SI ratings showed a more confident identification of abnormality on enhanced images (p = 0.0001). Image-processing resulted in increased CNR of abnormal hippocampus without affecting the CNR of normal gray matter. This selective increase in conspicuity of abnormal hippocampus was associated with more confident identification of hippocampal signal alteration. Copyright © 2018 Academic Radiology. Published by Elsevier Inc. All rights reserved.

SedCT: MATLAB™ tools for standardized and quantitative processing of sediment core computed tomography (CT) data collected using a medical CT scanner

NASA Astrophysics Data System (ADS)

Reilly, B. T.; Stoner, J. S.; Wiest, J.

2017-08-01

Computed tomography (CT) of sediment cores allows for high-resolution images, three-dimensional volumes, and down core profiles. These quantitative data are generated through the attenuation of X-rays, which are sensitive to sediment density and atomic number, and are stored in pixels as relative gray scale values or Hounsfield units (HU). We present a suite of MATLAB™ tools specifically designed for routine sediment core analysis as a means to standardize and better quantify the products of CT data collected on medical CT scanners. SedCT uses a graphical interface to process Digital Imaging and Communications in Medicine (DICOM) files, stitch overlapping scanned intervals, and create down core HU profiles in a manner robust to normal coring imperfections. Utilizing a random sampling technique, SedCT reduces data size and allows for quick processing on typical laptop computers. SedCTimage uses a graphical interface to create quality tiff files of CT slices that are scaled to a user-defined HU range, preserving the quantitative nature of CT images and easily allowing for comparison between sediment cores with different HU means and variance. These tools are presented along with examples from lacustrine and marine sediment cores to highlight the robustness and quantitative nature of this method.

78 FR 44965 - Notice of Proposed Withdrawal Extension and Opportunity for Public Meeting for the Grays Lake...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-25

... National Wildlife Refuge Headquarters capital investments and will cover the same area currently withdrawn... constrain nondiscretionary uses which could result in permanent loss of significant values and capital investments. A water right with a priority date of 1969 is in place for stock water, domestic, fire protection...

Nutritional composition and cooking characteristics of tepary bean (Phaseolus acutifolius Gray) in comparison with common bean (Phaseolus vulgaris L.)

USDA-ARS?s Scientific Manuscript database

Tepary bean is a highly abiotic stress tolerant orphan crop, however, there has been limited research on its nutritional value and cooking characteristics, key aspects when considering the potential for broader adoption globally. The goal of this study was to evaluate a large set of seed composition...

Cognitive performance is associated with gray matter decline in first-episode psychosis.

PubMed

Dempster, Kara; Norman, Ross; Théberge, Jean; Densmore, Maria; Schaefer, Betsy; Williamson, Peter

2017-06-30

Progressive loss of gray matter has been demonstrated over the early course of schizophrenia. Identification of an association between cognition and gray matter may lead to development of early interventions directed at preserving gray matter volume and cognitive ability. The present study evaluated the association between gray matter using voxel-based morphometry (VBM) and cognitive testing in a sample of 16 patients with first-episode psychosis. A simple regression was applied to investigate the association between gray matter at baseline and 80 months and cognitive tests at baseline. Performance on the Wisconsin Card Sorting Task (WCST) at baseline was positively associated with gray matter volume in several brain regions. There was an association between decreased gray matter at baseline in the nucleus accumbens and Trails B errors. Performing worse on Trails B and making more WCST perseverative errors at baseline was associated with gray matter decline over 80 months in the right globus pallidus, left inferior parietal lobe, Brodmann's area (BA) 40, and left superior parietal lobule and BA 7 respectively. All significant findings were cluster corrected. The results support a relationship between aspects of cognitive impairment and gray matter abnormalities in first-episode psychosis. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Structural and behavioral correlates of abnormal encoding of money value in the sensorimotor striatum in cocaine addiction.

PubMed

Konova, Anna B; Moeller, Scott J; Tomasi, Dardo; Parvaz, Muhammad A; Alia-Klein, Nelly; Volkow, Nora D; Goldstein, Rita Z

2012-10-01

Abnormalities in frontostriatal systems are thought to be central to the pathophysiology of addiction, and may underlie the maladaptive processing of the highly generalizable reinforcer, money. Although abnormal frontostriatal structure and function have been observed in individuals addicted to cocaine, it is less clear how individual variability in brain structure is associated with brain function to influence behavior. Our objective was to examine frontostriatal structure and neural processing of money value in chronic cocaine users and closely matched healthy controls. A reward task that manipulated different levels of money was used to isolate neural activity associated with money value. Gray matter volume measures were used to assess frontostriatal structure. Our results indicated that cocaine users had an abnormal money value signal in the sensorimotor striatum (right putamen/globus pallidus) that was negatively associated with accuracy adjustments to money and was more pronounced in individuals with more severe use. In parallel, group differences were also observed in both the function and gray matter volume of the ventromedial prefrontal cortex; in the cocaine users, the former was directly associated with response to money in the striatum. These results provide strong evidence for abnormalities in the neural mechanisms of valuation in addiction and link these functional abnormalities with deficits in brain structure. In addition, as value signals represent acquired associations, their abnormal processing in the sensorimotor striatum, a region centrally implicated in habit formation, could signal disadvantageous associative learning in cocaine addiction. © 2012 Published 2012. This article is a US Government work and is in the public domain in the USA.

Optimization of parameter values for complex pulse sequences by simulated annealing: application to 3D MP-RAGE imaging of the brain.

PubMed

Epstein, F H; Mugler, J P; Brookeman, J R

1994-02-01

A number of pulse sequence techniques, including magnetization-prepared gradient echo (MP-GRE), segmented GRE, and hybrid RARE, employ a relatively large number of variable pulse sequence parameters and acquire the image data during a transient signal evolution. These sequences have recently been proposed and/or used for clinical applications in the brain, spine, liver, and coronary arteries. Thus, the need for a method of deriving optimal pulse sequence parameter values for this class of sequences now exists. Due to the complexity of these sequences, conventional optimization approaches, such as applying differential calculus to signal difference equations, are inadequate. We have developed a general framework for adapting the simulated annealing algorithm to pulse sequence parameter value optimization, and applied this framework to the specific case of optimizing the white matter-gray matter signal difference for a T1-weighted variable flip angle 3D MP-RAGE sequence. Using our algorithm, the values of 35 sequence parameters, including the magnetization-preparation RF pulse flip angle and delay time, 32 flip angles in the variable flip angle gradient-echo acquisition sequence, and the magnetization recovery time, were derived. Optimized 3D MP-RAGE achieved up to a 130% increase in white matter-gray matter signal difference compared with optimized 3D RF-spoiled FLASH with the same total acquisition time. The simulated annealing approach was effective at deriving optimal parameter values for a specific 3D MP-RAGE imaging objective, and may be useful for other imaging objectives and sequences in this general class.

Infrared and visible image fusion with the target marked based on multi-resolution visual attention mechanisms

NASA Astrophysics Data System (ADS)

Huang, Yadong; Gao, Kun; Gong, Chen; Han, Lu; Guo, Yue

2016-03-01

During traditional multi-resolution infrared and visible image fusion processing, the low contrast ratio target may be weakened and become inconspicuous because of the opposite DN values in the source images. So a novel target pseudo-color enhanced image fusion algorithm based on the modified attention model and fast discrete curvelet transformation is proposed. The interesting target regions are extracted from source images by introducing the motion features gained from the modified attention model, and source images are performed the gray fusion via the rules based on physical characteristics of sensors in curvelet domain. The final fusion image is obtained by mapping extracted targets into the gray result with the proper pseudo-color instead. The experiments show that the algorithm can highlight dim targets effectively and improve SNR of fusion image.

Representation of aversive prediction errors in the human periaqueductal gray

PubMed Central

Roy, Mathieu; Shohamy, Daphna; Daw, Nathaniel; Jepma, Marieke; Wimmer, Elliott; Wager, Tor D.

2014-01-01

Pain is a primary driver of learning and motivated action. It is also a target of learning, as nociceptive brain responses are shaped by learning processes. We combined an instrumental pain avoidance task with an axiomatic approach to assessing fMRI signals related to prediction errors (PEs), which drive reinforcement-based learning. We found that pain PEs were encoded in the periaqueductal gray (PAG), an important structure for pain control and learning in animal models. Axiomatic tests combined with dynamic causal modeling suggested that ventromedial prefrontal cortex, supported by putamen, provides an expected value-related input to the PAG, which then conveys PE signals to prefrontal regions important for behavioral regulation, including orbitofrontal, anterior mid-cingulate, and dorsomedial prefrontal cortices. Thus, pain-related learning involves distinct neural circuitry, with implications for behavior and pain dynamics. PMID:25282614

Experimentally constrained ( p , γ ) Y 89 and ( n , γ ) Y 89 reaction rates relevant to p -process nucleosynthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Larsen, A. C.; Guttormsen, M.; Schwengner, R.

The nuclear level density and the g-ray strength function have been extracted for 89Y, using the Oslo Method on 89Y(p,p'γ) 89Y coincidence data. The g-ray strength function displays a low-energy enhancement consistent with previous observations in this mass region ( 93-98Mo). Shell-model calculations give support that the observed enhancement is due to strong, low-energy M1 transitions at high excitation energies. The data were further used as input for calculations of the 88Sr(p,γ) 89Y and 88Y(n,γ) 89Y cross sections with the TALYS reaction code. Lastly, comparison with cross-section data, where available, as well as with values from the BRUSLIB library, showsmore » a satisfying agreement.« less

Experimentally constrained ( p , γ ) Y 89 and ( n , γ ) Y 89 reaction rates relevant to p -process nucleosynthesis

DOE PAGES

Larsen, A. C.; Guttormsen, M.; Schwengner, R.; ...

2016-04-21

The nuclear level density and the g-ray strength function have been extracted for 89Y, using the Oslo Method on 89Y(p,p'γ) 89Y coincidence data. The g-ray strength function displays a low-energy enhancement consistent with previous observations in this mass region ( 93-98Mo). Shell-model calculations give support that the observed enhancement is due to strong, low-energy M1 transitions at high excitation energies. The data were further used as input for calculations of the 88Sr(p,γ) 89Y and 88Y(n,γ) 89Y cross sections with the TALYS reaction code. Lastly, comparison with cross-section data, where available, as well as with values from the BRUSLIB library, showsmore » a satisfying agreement.« less

Erratum: ``Structure and Colors of Diffuse Emission in the Spitzer Galactic First Look Survey'' (ApJS, 154, 281 [2004])

NASA Astrophysics Data System (ADS)

Ingalls, James G.; Miville-Deschênes, M.-A.; Reach, William T.; Noriega-Crespo, A.; Carey, Sean J.; Boulanger, F.; Stolovy, S. R.; Padgett, Deborah L.; Burgdorf, M. J.; Fajardo-Acosta, S. B.; Glaccum, W. J.; Helou, G.; Hoard, D. W.; Karr, J.; O'Linger, J.; Rebull, L. M.; Rho, J.; Stauffer, J. R.; Wachter, S.

2006-05-01

We have discovered an error in the scaling of our IRAC 8 μm and MIPS 70 μm data, which affected the caption for Figure 1 and the vertical axis scales for Figure 2. The original units in the images displayed in Figure 1 were MJy sr-1 for 8 μm and μJy arcsec-2 for MIPS 24 and 70 μm. We incorrectly multiplied our IRAC data by 0.0425 (the conversion from μJy arcsec-2 to MJy sr-1), but neglected to multiply our MIPS 70 μm data by that factor. (MIPS 24 μm data were scaled correctly.) Thus, contrary to the caption of Figure 1, the gray levels for panels (a) and (b) actually range from 6.7 to 7.8 MJy sr-1, and the gray levels for panels (e) and (f) actually range from 0.85 to 20.8 MJy sr-1. The power spectra in Figure 2 should have been normalized such that the integral over the spectrum equals the mean square image surface brightness. In the original paper, however, the IRAC power spectrum was incorrectly multiplied by (0.0425)2, whereas the MIPS 70 μm spectrum should have been multiplied by this factor but was not. We correct this in a revised version of Figure 2 included here. We thank Rick Arendt for calling our attention to this error.

Outer Continental Shelf environmental assessment program. Final reports of principal investigators. Volume 43

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1986-06-01

Contents include: Assessment of gray whale feeding grounds and sea floor interaction in the northeastern Bering Sea; Feeding ecology of the gray whale in the northern Bering Sea; Feeding ecology of the gray whale in the Chirikof Basin, summer 1982; Project rationale, design, summary; Distribution, production, and ecology of gray whale prey species; Distribution and abundance of gray whales in the Chirikof Basin, summer 1982; Assessment of gray whale feeding grounds and sea floor interaction in the northeastern Bering Sea; Feeding ecology of gray whales in the Chirikof Basin; Investigations of belukha whales in coastal waters of western and northernmore » Alaska, 1982-1983: marking and tracking of whales in Bristol Bay; Belukha whale responses to industrial noise in Nushagak Bay, Alaska.« less

Osteoporosis prediction from the mandible using cone-beam computed tomography

PubMed Central

Al Haffar, Iyad; Khattab, Razan

2014-01-01

Purpose This study aimed to evaluate the use of dental cone-beam computed tomography (CBCT) in the diagnosis of osteoporosis among menopausal and postmenopausal women by using only a CBCT viewer program. Materials and Methods Thirty-eight menopausal and postmenopausal women who underwent dual-energy X-ray absorptiometry (DXA) examination for hip and lumbar vertebrae were scanned using CBCT (field of view: 13 cm×15 cm; voxel size: 0.25 mm). Slices from the body of the mandible as well as the ramus were selected and some CBCT-derived variables, such as radiographic density (RD) as gray values, were calculated as gray values. Pearson's correlation, one-way analysis of variance (ANOVA), and accuracy (sensitivity and specificity) evaluation based on linear and logistic regression were performed to choose the variable that best correlated with the lumbar and femoral neck T-scores. Results RD of the whole bone area of the mandible was the variable that best correlated with and predicted both the femoral neck and the lumbar vertebrae T-scores; further, Pearson's correlation coefficients were 0.5/0.6 (p value=0.037/0.009). The sensitivity, specificity, and accuracy based on the logistic regression were 50%, 88.9%, and 78.4%, respectively, for the femoral neck, and 46.2%, 91.3%, and 75%, respectively, for the lumbar vertebrae. Conclusion Lumbar vertebrae and femoral neck osteoporosis can be predicted with high accuracy from the RD value of the body of the mandible by using a CBCT viewer program. PMID:25473633

Modulation on brain gray matter activity and white matter integrity by APOE ε4 risk gene in cognitively intact elderly: A multimodal neuroimaging study.

PubMed

Cai, Suping; Jiang, Yuanyuan; Wang, Yubo; Wu, Xiaoming; Ren, Junchan; Lee, Min Seob; Lee, Sunghoon; Huang, Liyu

2017-03-30

Apolipoprotein E (APOE) ε4 allele is the genetic risk factor with the most established evidence for sporadic Alzheimer's disease. Previous neuroimaging studies have demonstrated insufficiently consistent functional and structural changes among healthy APOE ε4 carriers when compared to non-carriers. Here, in a cognitively intact elderly group (a total of 110: 45 APOE ε4 carriers, 65 non-carriers), we aimed to investigate the potential role of APOE ε4 in the modulation of grey matter activity, white matter integrity, and brain morphology before the development of clinically significant symptoms and signs, by methods of: amplitude of low frequency fluctuations and regional homogeneity analysis based on resting state fMRI, and fiber tractography approach based on diffusion tensor imaging. Our results revealed that compared to non-carriers, APOE ε4 carriers showed: (1) an inconsistent pattern of activity change in the default mode network, including increased gray matter activity in anterior cingulate cortex and medial prefrontal cortex and decreased activity in precuneus; (2) lower mean diffusivity (MD) in fibers of corona radiata and corpus callosum, and lower axial diffusivity in genu of corpus callosum; and (3) significant positive correlation between the MD value of the right superior corona radiate and gross white matter volume; significant negative correlation between the MD value of the right superior corona radiate and Mini-Mental State Examination (MMSE) score. Our results suggested that APOE ε4 gene can modulate gray matter activity and white matter integrity in cognitive and memory related regions, even before any clinical or neuropsychic symtoms or signs of imminent disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Strong Evidence of Variable Micro-meteor Flux from Apollo 17 Samples Obtained at Shorty Crater and on the Light Mantle Avalanche at Taurus-Littrow

NASA Astrophysics Data System (ADS)

Schmitt, H. H.; Petro, N. E.

2017-12-01

Light-gray regolith overlying the orange and black pyroclastic ash (Schmitt, 2017) at Shorty Crater protected the ash from incorporation into surrounding basaltic regolith for 3.5 billion years (Tera and Wasserburg, 1976; Saito and Alexander, 1979). Inspection of LROC images indicate this regolith probably came from a 350 m diameter, degraded impact crater (Fitzgibbon Crater), about 1 km NNE of Shorty. This regolith was derived largely from basalt and spread over the ash deposit about 24 Myr (Eugster, et al., 1979, corrected for post-Shorty exposure) after the last ash eruption. Maturity indexes for light gray regolith samples 74441 and 74461 are about 8 (Morris, 1978) and agglutinate concentrations are 8% and 7.7% (Heiken and McKay, 1974), respectively. These values are inconsistent with the exposure and cycling of the light-gray regolith during 3.5 billion years in the lunar surface impact environment (i.e., the time between ash deposition and the light mantle avalanche). If agglutinate content and Is/FeO indexes largely reflect the cumulative effect of micro-meteor impacts, as generally concluded, the light-gray regolith formed in an environment with significantly less micro-meteor flux than that which has prevailed more recently. 14-18% of fragile, ropy glass in the light-gray regolith, as compared with <1% in presently exposed Taurus-Littrow regoliths, also is consistent with low micro-meteor flux during development. The high recent micro-meteor flux appears to have existed for at least for the last 75 million years (Schmitt, et al., 2017), the estimated time using LROC-based crater frequency analysis (van der Bogert, et al., 2012) since the light mantle avalanche of South Massif regolith covered the light-gray regolith. New regolith on the light mantle appears to be developing a higher concentration of agglutinates and a higher maturity index relative to regolith in deeper portions of the unit. Light mantle avalanche samples 73141 (subsurface) and 73121 (near surface), have agglutinates at 32% and 42% and Is/FeO indexes of 48 and 78, respectively. This difference further supports the hypothesis of a highly variable micro-meteor flux throughout lunar history, with its current flux being significantly higher than for some period both prior to and subsequent to 3.5 Ga.

Line fitting based feature extraction for object recognition

NASA Astrophysics Data System (ADS)

Li, Bing

2014-06-01

Image feature extraction plays a significant role in image based pattern applications. In this paper, we propose a new approach to generate hierarchical features. This new approach applies line fitting to adaptively divide regions based upon the amount of information and creates line fitting features for each subsequent region. It overcomes the feature wasting drawback of the wavelet based approach and demonstrates high performance in real applications. For gray scale images, we propose a diffusion equation approach to map information-rich pixels (pixels near edges and ridge pixels) into high values, and pixels in homogeneous regions into small values near zero that form energy map images. After the energy map images are generated, we propose a line fitting approach to divide regions recursively and create features for each region simultaneously. This new feature extraction approach is similar to wavelet based hierarchical feature extraction in which high layer features represent global characteristics and low layer features represent local characteristics. However, the new approach uses line fitting to adaptively focus on information-rich regions so that we avoid the feature waste problems of the wavelet approach in homogeneous regions. Finally, the experiments for handwriting word recognition show that the new method provides higher performance than the regular handwriting word recognition approach.

Analysis of the convective timescale during the major floods in the NE Iberian Peninsula since 1871

NASA Astrophysics Data System (ADS)

Pino, David; Reynés, Artur; Mazon, Jordi; Carles Balasch, Josep; Lluis Ruiz-Bellet, Josep; Tuset, Jordi; Barriendos, Mariano; Castelltort, Xavier

2016-04-01

Floods are the most severe natural hazard in the western Mediterranean basin. They cause most of the damages and most of the victims. Some of the selected floods caused more than one hundred casualties each and a large quantity of damages in infrastructures. In a previous work (Balasch, et al., 2015), using the PREDIFLOOD database (Barriendos et al., 2014) we studied the atmospheric conditions that occurred during some of the most important floods occurred in the north-east of the Iberian Peninsula in the last centuries: 1874, 1875, 1894, 1897, 1898, 1901, 1907, 1913, 1919, 1932, 1937, 1940, 1962, 1963, 1977, 1994, 1996, and 2000. We analyzed the atmospheric synoptic situations at the time of each flood from the data provided by NOAA 20th Century Reanalysis and we compared it to the rainfall spatial distributions obtained with the hydrological modeling. In this work we enlarge the previous investigation by analyzing the evolution of a convective index proposed by Done et al. (2006) and modified by Molini et al. (2011). This index, called convective time scale, is obtained from the evolution of CAPE and is used to separate equilibrium and non-equilibrium convection. In the former, CAPE generated by large-scale processes is balanced by the consumption due to convection. In the second case, CAPE is created by large-scale processes over a long time and is rapidly consumed during outbreaks of convection. Both situations produced a totally different evolution of CAPE with low and approximately constant values in the first case and large and variable values in the second. Additionally, from this index it can be estimated the rainfall rate. We use data provided by NOAA 20th Century Reanalysis, to calculate the convective time scale and to analyze its evolution and horizontal distribution. We study the correspondence between the convective timescale, the season when the flood occurred, duration of the rainfall, and the specific peak flow rate of the flood. Finally, for the most recent episodes rainfall rate estimation from the convective timescale is compared with the observations. Balasch, J. C., Ruiz-Bellet, J. L., Tuset, J., Barriendos, M., Mazón, J., Pino, D. and Castelltort, X.: Transdisciplinary and multiscale reconstruction of the major flash floods in NE Iberian Peninsula. EGU General Assembly, 2015. Barriendos, M., Ruiz--Bellet, J. L., Tuset, J., Mazon, J., Balasch, J. C., Pino, D., Ayala, J. L.: The "Prediflood" database of historical floods in Catalonia (NE Iberian Peninsula) AD 1035--2013, and its potential applications in flood analysis, Hydrol. Earth Syst. Sci., 18, 4807-4823, 2014. Done, J. M., Craig, G. C., Gray, S. L., Clark, P. A., and Gray, M. E. B.: Mesoscale simulations of organized convection: Importance of convective equilibrium, Q. J. Roy. Meteor. Soc., 132, 737-756, 2006. Molini, L., Parodi, A., Rebora, N. and Craig, G. C.: Classifying severe rainfall events over Italy by hydrometeorological and dynamical criteria, Q. J. Roy. Meteor. Soc., 137, 148-154, 2011.

Nonlinear defect localized modes and composite gray and anti-gray solitons in one-dimensional waveguide arrays with dual-flip defects

NASA Astrophysics Data System (ADS)

Liu, Yan; Guan, Yefeng; Li, Hai; Luo, Zhihuan; Mai, Zhijie

2017-08-01

We study families of stationary nonlinear localized modes and composite gray and anti-gray solitons in a one-dimensional linear waveguide array with dual phase-flip nonlinear point defects. Unstaggered fundamental and dipole bright modes are studied when the defect nonlinearity is self-focusing. For the fundamental modes, symmetric and asymmetric nonlinear modes are found. Their stable areas are studied using different defect coefficients and their total power. For the nonlinear dipole modes, the stability conditions of this type of mode are also identified by different defect coefficients and the total power. When the defect nonlinearity is replaced by the self-defocusing one, staggered fundamental and dipole bright modes are created. Finally, if we replace the linear waveguide with a full nonlinear waveguide, a new type of gray and anti-gray solitons, which are constructed by a kink and anti-kink pair, can be supported by such dual phase-flip defects. In contrast to the usual gray and anti-gray solitons formed by a single kink, their backgrounds on either side of the gray hole or bright hump have the same phase.

Histological Underpinnings of Grey Matter Changes in Fibromyalgia Investigated Using Multimodal Brain Imaging.

PubMed

Pomares, Florence B; Funck, Thomas; Feier, Natasha A; Roy, Steven; Daigle-Martel, Alexandre; Ceko, Marta; Narayanan, Sridar; Araujo, David; Thiel, Alexander; Stikov, Nikola; Fitzcharles, Mary-Ann; Schweinhardt, Petra

2017-02-01

Chronic pain patients present with cortical gray matter alterations, observed with anatomical magnetic resonance (MR) imaging. Reduced regional gray matter volumes are often interpreted to reflect neurodegeneration, but studies investigating the cellular origin of gray matter changes are lacking. We used multimodal imaging to compare 26 postmenopausal women with fibromyalgia with 25 healthy controls (age range: 50-75 years) to test whether regional gray matter volume decreases in chronic pain are associated with compromised neuronal integrity. Regional gray matter decreases were largely explained by T1 relaxation times in gray matter, a surrogate measure of water content, and not to any substantial degree by GABA A receptor concentration, an indirect marker of neuronal integrity measured with [ 18 F] flumazenil PET. In addition, the MR spectroscopy marker of neuronal viability, N-acetylaspartate, did not differ between patients and controls. These findings suggest that decreased gray matter volumes are not explained by compromised neuronal integrity. Alternatively, a decrease in neuronal matter could be compensated for by an upregulation of GABA A receptors. The relation between regional gray matter and T1 relaxation times suggests decreased tissue water content underlying regional gray matter decreases. In contrast, regional gray matter increases were explained by GABA A receptor concentration in addition to T1 relaxation times, indicating perhaps increased neuronal matter or GABA A receptor upregulation and inflammatory edema. By providing information on the histological origins of cerebral gray matter alterations in fibromyalgia, this study advances the understanding of the neurobiology of chronic widespread pain. Regional gray matter alterations in chronic pain, as detected with voxel-based morphometry of anatomical magnetic resonance images, are commonly interpreted to reflect neurodegeneration, but this assumption has not been tested. We found decreased gray matter in fibromyalgia to be associated with T1 relaxation times, a surrogate marker of water content, but not with GABA A receptor concentration, a surrogate of neuronal integrity. In contrast, regional gray matter increases were partly explained by GABA A receptor concentration, indicating some form of neuronal plasticity. The study emphasizes that voxel-based morphometry is an exploratory measure, demonstrating the need to investigate the histological origin of gray matter alterations for every distinct clinical entity, and advances the understanding of the neurobiology of chronic (widespread) pain. Copyright © 2017 the authors 0270-6474/17/371091-12$15.00/0.

Episodic vein formation in Gale crater, Mars: evidence for an extended history of liquid water

NASA Astrophysics Data System (ADS)

Kronyak, R. E.; Fedo, C.; Banham, S.; Edgett, K. S.; Newsom, H. E.; Nachon, M.; Kah, L. C.

2017-12-01

The sedimentary rock record of Gale crater is consistent with deposition in an ancient lake basin. These strata represent aqueous and potentially habitable past conditions that existed over a relatively small part of Mars' geologic history. Post-depositional fluid migration is recorded by the presence of veins, which have been prevalent features throughout Curiosity's mission. These veins record later episodes of fluid flow and represent an extended history of liquid water stability, and perhaps habitability. White Ca-sulfate veins are observed in the Bradbury (Yellowknife Bay), Mount Sharp (Murray formation), and Siccar Point (Stimson formation) groups across a range of lithologies. At Yellowknife Bay and in the Stimson, Ca-sulfate veins characteristically exhibit mm-scale thicknesses. In the Pahrump Hills (PH) area, 62% of measured veins in the Murray formation are <3 mm thick. However, PH also contains a population of veins that range from 1-5 cm thick that commonly contain gray inclusions and are crosscut by thinner white veins. Similar gray material occurs along the interface between wall rock and Ca-sulfate and is interpreted as a precursor vein fill. Gray veins at PH are more erosionally resistant relative to Ca-sulfate and average 1 mm in width. Additionally, gray veins exhibit elevated Mg and depleted Ca, distinguishing them compositionally from Ca-sulfate veins. Veins continue locally throughout the stratigraphic section. The lowermost Stimson sandstones at the Missoula outcrop contain white clasts and elevated Ca-sulfate, suggesting the formation of Murray veins prior to the deposition of the Stimson formation. Near the Old Soaker outcrop, bedding-parallel sulfate may represent syndepositional gypsum precipitation. In the context of time, the multiple vein systems identified in the Gale crater sedimentary fill shed light on the sequence and evolution of fluids responsible for their deposition. It is envisioned that sulfates first precipitated contemporaneously with the deposition of the Murray formation, followed by burial, lithification, and fracturing to form the earliest gray and sulfate veins. The Murray was then exhumed and eroded, followed by deposition and lithification of the Stimson formation, fracturing, and precipitation of the latest sulfate veins.

Gray Infrastructure Tool | EPA Center for Exposure ...

EPA Pesticide Factsheets

2016-03-07

Natural channel with flood plain panel added Default depth increment of 0.5 is used for Natural Channel with FP Units option added – SI or US units. Default option is US units Conversion options added wherever necessary Additional options added to FTABLE such as clear FTABLE Significant digits for FTABLE calculations is changed to 4 Previously a default Cd value is used for calculations (under-drain and riser) but now a user defined value is used Default values of Cd for riser orifice and under-drain textboxes is changed to 0.6 Previously a default increment value of 0.1 is used for all the channel panels but now user can specify the increment

Why Does Hair Turn Gray?

MedlinePlus

... Videos for Educators Search English Español Why Does Hair Turn Gray? KidsHealth / For Kids / Why Does Hair Turn Gray? Print en español ¿Por qué se ... ever watched someone try to cover up gray hair by dyeing it? Or maybe you wonder why ...

Geo-diversity and geo-materials in the region of Rabat-Salé-Zemmour-Zaer: Characterization and Rationalization of Utilization

NASA Astrophysics Data System (ADS)

Belhaj, Siham; Bahi, Lahcen; Akhssas, Ahmed

2016-04-01

The Rabat-Salé-Zemmour-Zaer (RSZZ) is distinguished by a rich geology is varied. Outcrops are found in both the Paleozoic basement, especially along the major wadis in the area and a fairly extensive coverage postpaléozoïque and locally very thick. It offers a wide variety of petrographic facies some of which the construction of geomaterials value (GMC), very solicited by the construction sector and public works (BTP). Among the most important GMC furniture and beds of RSZZ: - The sands. They are a fundamental component for the preparation of mortar and hydraulic concrete. They also enter into the composition of adobe and are used for the foundation of shoes. -The Clays. They are mainly used by ceramists (industrial units manufacturing tiles). The red clay of Triassic age are most represented in the Region in deposits whose thickness can reach several tens of meters. -The Calcarenite. : It is the most used local stone in building the cities of Rabat and Salé, where she is well known as the Stone of Salé. The same stone is used in the manufacture of lime through calcination. Geologically, it is a calcareous sandstone, of Pliocene-Quaternary age that is in the form of a dune system that runs parallel to the Atlantic coast. -The Limestones: These massive limestones and more or less metamorphosed dolomitized Devonian. These limestone outcrop along major wadis of the region (Akrech, Ykem, ...) as layers sometimes quite thick and more or less tectonized. According to localities, these limestones show a wide range of colors (white, gray, black pink) and a wide variety of structures (colorful, beaded, veined, textured) - The quartzites. They correspond to Ordovician bars that appear quite often emerged in relation to other surrounding formations because of their high resistance to erosion. The rock is generally brownish gray and shows a very high hardness related to its siliceous. Local and temporary holdings allow blocks extraction for various public works (foundation, basement, filling). - Granites. The granitic pluton hercynien of Zaer, of Upper Carboniferous age, outcrops over an area of over 700 km2. It offers two main granitic facies: an internal facies biotite-muscovite, light gray color and grainy equigranular structure; and an external facies of biotite only bluish gray color and grained porphyritic texture. With this geological diversity, the region of RSZZ could always ensure its supply and self-sufficiency in GMC. However, large construction sites launched in recent years (from 200,000 housing schemes, construction of satellite towns, the development plan of the valley of Bouregreg ...) made the demand on those regional GMC has become very strong. Thus the pace of operations has been accelerated to meet this demand increasingly growing; the consequence is a serious harm to the environment. The purpose of this communication is to raise awareness among operators (local authorities, elected representatives, operators, investors, public authorities ...) on the need to double vigilance on the management of the geological heritage. Indeed, these non-renewable resources on a human scale to be exploited in a rational way and in the context of Sustainable Development. Furthermore, we recall that in the Region of RSZZ exist geomaterials outcrops of great scientific and educational value that must be protected and prohibited from exploitation as well to preserve geological heritage.

Treatment of Simulated Shipboard Gray Water in a Lab-Scale Membrane Bioreactor

DTIC Science & Technology

2005-12-01

bioreactors ( MBRs ). MBRs with submerged membrane modules are considered a promising wastewater technology for use aboard ships since significant treatment...system, which consisted of an equalization tank, an MBR with submerged hollow fiber membranes, and a UV disinfection system. The reactor was...1999) optimized removal of TN in an intermittently aerated MBR with submerged hollow fiber membranes. They achieved an average TN removal of 83

Endoscopic ultrasound for the characterization and staging of rectal cancer. Current state of the method. Technological advances and perspectives.

PubMed

Gersak, Mariana M; Badea, Radu; Graur, Florin; Hajja, Nadim Al; Furcea, Luminita; Dudea, Sorin M

2015-06-01

Endoscopic ultrasound is the most accurate type of examination for the assessment of rectal tumors. Over the years, the method has advanced from gray-scale examination to intravenous contrast media administration and to different types of elastography. The multimodal approach of tumors (transrectal, transvaginal) is adapted to each case. 3D ultrasound is useful for spatial representation and precise measurement of tumor formations, using CT/MR image reconstruction; color elastography is useful for tumor characterization and staging; endoscopic ultrasound using intravenous contrast agents can help study the amount of contrast agent targeted at the level of the tumor formations and contrast wash-in/wash-out time, based on the curves displayed on the device. The transvaginal approach often allows better visualization of the tumor than the transrectal approach. Performing the procedure with the rectal ampulla distended with contrast agent may be seen as an optimization of the examination methodology. All these aspects are additional methods for gray-scale endoscopic ultrasound, capable of increasing diagnostic accuracy. This paper aims at reviewing the progress of transrectal and transvaginal ultrasound, generically called endoscopic ultrasound, for rectal tumor diagnosis and staging, with emphasis on the current state of the method and its development trends.

Reduced gray matter volume is correlated with frontal cognitive and behavioral impairments in Parkinson's disease.

PubMed

Terada, Tatsuhiro; Miyata, Jun; Obi, Tomokazu; Kubota, Manabu; Yoshizumi, Miho; Murai, Toshiya

2018-07-15

To identify the brain-volume reductions associated with frontal cognitive and behavioral impairments in Parkinson's disease (PD). Forty PD patients without dementia or amnesia (Hoehn and Yahr stage 3) and 10 age-matched controls underwent brain magnetic resonance imaging. Cognitive and behavioral impairments were assessed by using the Frontal Assessment Battery (FAB) and Frontal Systems Behavioral Scale (FrSBe), respectively. We applied voxel-based morphometry to investigate the correlations of regional gray matter volume with FAB, FrSBe, and physical disability. FAB was significantly lower in PD than in controls. FrSBe was significantly higher after PD onset than before, notably in the apathy subscale. FAB and FrSBe were significantly intercorrelated. In PD patients, left inferior frontal volume was positively correlated with FAB, whereas right precentral volume was negatively correlated with FrSBe total score. The brain volumes in both of these regions were not correlated with the Unified PD Rating Scale III. Behavioral impairments in PD tended to coexist with progression of frontal cognitive impairment. Regional atrophy within the frontal lobe was associated with both frontal cognitive and behavioral impairments. However, the specific region responsible for behavioral impairment differed from that for frontal cognitive impairment. These associations were independent of physical disability. Copyright © 2018 Elsevier B.V. All rights reserved.

Document image binarization using "multi-scale" predefined filters

NASA Astrophysics Data System (ADS)

Saabni, Raid M.

2018-04-01

Reading text or searching for key words within a historical document is a very challenging task. one of the first steps of the complete task is binarization, where we separate foreground such as text, figures and drawings from the background. Successful results of this important step in many cases can determine next steps to success or failure, therefore it is very vital to the success of the complete task of reading and analyzing the content of a document image. Generally, historical documents images are of poor quality due to their storage condition and degradation over time, which mostly cause to varying contrasts, stains, dirt and seeping ink from reverse side. In this paper, we use banks of anisotropic predefined filters in different scales and orientations to develop a binarization method for degraded documents and manuscripts. Using the fact, that handwritten strokes may follow different scales and orientations, we use predefined sets of filter banks having various scales, weights, and orientations to seek a compact set of filters and weights in order to generate diffrent layers of foregrounds and background. Results of convolving these fiters on the gray level image locally, weighted and accumulated to enhance the original image. Based on the different layers, seeds of components in the gray level image and a learning process, we present an improved binarization algorithm to separate the background from layers of foreground. Different layers of foreground which may be caused by seeping ink, degradation or other factors are also separated from the real foreground in a second phase. Promising experimental results were obtained on the DIBCO2011 , DIBCO2013 and H-DIBCO2016 data sets and a collection of images taken from real historical documents.

Comment on "An improved gray Lattice Boltzmann model for simulating fluid flow in multi-scale porous media": Intrinsic links between LBE Brinkman schemes

NASA Astrophysics Data System (ADS)

Ginzburg, Irina

2016-02-01

In this Comment on the recent work (Zhu and Ma, 2013) [11] by Zhu and Ma (ZM) we first show that all three local gray Lattice Boltzmann (GLB) schemes in the form (Zhu and Ma, 2013) [11]: GS (Chen and Zhu, 2008; Gao and Sharma, 1994) [1,4], WBS (Walsh et al., 2009) [12] and ZM, fail to get constant Darcy's velocity in series of porous blocks. This inconsistency is because of their incorrect definition of the macroscopic velocity in the presence of the heterogeneous momentum exchange, while the original WBS model (Walsh et al., 2009) [12] does this properly. We improve the GS and ZM schemes for this and other related deficiencies. Second, we show that the ;discontinuous velocity; they recover on the stratified interfaces with their WBS scheme is inherent, in different degrees, to all LBE Brinkman schemes, including ZM scheme. None of them guarantees the stress and the velocity continuity by their implicit interface conditions, even in the frame of the two-relaxation-times (TRT) collision operator where these two properties are assured in stratified Stokes flow, Ginzburg (2007) [5]. Third, the GLB schemes are presented in work (Zhu and Ma, 2013) [11] as the alternative ones to direct, Brinkman-force based (BF) schemes (Freed, 1998; Nie and Martys, 2007) [3,8]. Yet, we show that the BF-TRT scheme (Ginzburg, 2008) [6] gets the solutions of any of the improved GLB schemes for specific, viscosity-dependent choice of its one or two local relaxation rates. This provides the principal difference between the GLB and BF: while the BF may respect the linearity of the Stokes-Brinkman equation rigorously, the GLB-TRT cannot, unless it reduces to the BF via the inverse transform of the relaxation rates. Furthermore, we show that, in limited parameter space, ;gray; schemes may run one another. From the practical point of view, permeability values obtained with the GLB are viscosity-dependent, unlike with the BF. Finally, the GLB shares with the BF a so-called anisotropy (Ginzburg, 2008; Nie and Martys, 2007) [6,8], that is, flow-direction-dependency in their effective viscosity corrections, related to the discretized spatial variation of the resistance forcing.

Research on Humpback and Blue Whales off California, Oregon and Washington in 2000

DTIC Science & Technology

2001-06-01

between 15 March and 15 November 2000. These included surveys of coastal waters (incl. Puget Sound ) for seasonal resident gray whales and surveys of...northern Puget Sound , two surveys on 22 May and 21 June in Grays Harbor. There were also seven days of effort making shore-observations of gray whales ...regularly in Northern Puget Sound From March to May and in Grays Harbor from March to July. Occasional sightings of gray whales were made in southern and

Time-efficient high-resolution whole-brain three-dimensional macromolecular proton fraction mapping

PubMed Central

Yarnykh, Vasily L.

2015-01-01

Purpose Macromolecular proton fraction (MPF) mapping is a quantitative MRI method that reconstructs parametric maps of a relative amount of macromolecular protons causing the magnetization transfer (MT) effect and provides a biomarker of myelination in neural tissues. This study aimed to develop a high-resolution whole-brain MPF mapping technique utilizing a minimal possible number of source images for scan time reduction. Methods The described technique is based on replacement of an actually acquired reference image without MT saturation by a synthetic one reconstructed from R1 and proton density maps, thus requiring only three source images. This approach enabled whole-brain three-dimensional MPF mapping with isotropic 1.25×1.25×1.25 mm3 voxel size and scan time of 20 minutes. The synthetic reference method was validated against standard MPF mapping with acquired reference images based on data from 8 healthy subjects. Results Mean MPF values in segmented white and gray matter appeared in close agreement with no significant bias and small within-subject coefficients of variation (<2%). High-resolution MPF maps demonstrated sharp white-gray matter contrast and clear visualization of anatomical details including gray matter structures with high iron content. Conclusions Synthetic reference method improves resolution of MPF mapping and combines accurate MPF measurements with unique neuroanatomical contrast features. PMID:26102097

Gamma-ray transfer and energy deposition in supernovae

NASA Technical Reports Server (NTRS)

Swartz, Douglas A.; Sutherland, Peter G.; Harkness, Robert P.

1995-01-01

Solutions to the energy-independent (gray) radiative transfer equations are compared to results of Monte Carlo simulations of the Ni-56 and Co-56 decay gamma-ray energy deposition in supernovae. The comparison shows that an effective, purely absorptive, gray opacity, kappa(sub gamma) approximately (0. 06 +/- 0.01)Y(sub e) sq cm/g, where Y is the total number of electrons per baryon, accurately describes the interaction of gamma-rays with the cool supernova gas and the local gamma-ray energy deposition within the gas. The nature of the gamma-ray interaction process (dominated by Compton scattering in the relativistic regime) creates a weak dependence of kappa(sub gamma) on the optical thickness of the (spherically symmetric) supernova atmosphere: The maximum value of kappa(sub gamma) applies during optically thick conditions when individual gamma-rays undergo multiple scattering encounters and the lower bound is reached at the phase characterized by a total Thomson optical depth to the center of the atmosphere tau(sub e) approximately less than 1. Gamma-ray deposition for Type Ia supernova models to within 10% for the epoch from maximum light to t = 1200 days. Our results quantitatively confirm that the quick and efficient solution to the gray transfer problem provides an accurate representation of gamma-ray energy deposition for a broad range of supernova conditions.

Target productions in forward and backward hemispheres in the interactions of 28Si-EM at 14.6A GeV

NASA Astrophysics Data System (ADS)

Abdelsalam, A.; El-Nagdy, M. S.; Abdalla, A. M.; Saber, A.

2015-11-01

This paper search for the results and properties of slow particle productions, appear as a gray and black tracks in nuclear emulsions, producing secondary charged particles which are emitted from 28Si interactions with emulsion nuclei at 14.6A GeV. The forward particles emission of interactions, (θlab<90∘) as well as the backward ones (θlab≥90∘), have been investigated. It includes the effect of both projectile mass number and energy on the production and multiplicities of these particles. The results compared with other experiments for the same target but with different projectiles and energies. The experimental data show that there are two different mechanisms responsible for the production of gray particles for the chosen channels of emission angles and each are energy dependence. This dependence is weakly on the projectile mass number. The same investigations are applied for black tracks producing particles. The experimental results show the production of these particles is purely target fragments independent on both projectile mass number and its energy. The anisotropy ratio of angular distribution (F/B) is applied for both kinds of particles which are found the value for gray particle production depends on the direction of emissions while it is unchanged for black particles.

Regional reliability of quantitative signal targeting with alternating radiofrequency (STAR) labeling of arterial regions (QUASAR).

PubMed

Tatewaki, Yasuko; Higano, Shuichi; Taki, Yasuyuki; Thyreau, Benjamin; Murata, Takaki; Mugikura, Shunji; Ito, Daisuke; Takase, Kei; Takahashi, Shoki

2014-01-01

Quantitative signal targeting with alternating radiofrequency labeling of arterial regions (QUASAR) is a recent spin labeling technique that could improve the reliability of brain perfusion measurements. Although it is considered reliable for measuring gray matter as a whole, it has never been evaluated regionally. Here we assessed this regional reliability. Using a 3-Tesla Philips Achieva whole-body system, we scanned four times 10 healthy volunteers, in two sessions 2 weeks apart, to obtain QUASAR images. We computed perfusion images and ran a voxel-based analysis within all brain structures. We also calculated mean regional cerebral blood flow (rCBF) within regions of interest configured for each arterial territory distribution. The mean CBF over whole gray matter was 37.74 with intraclass correlation coefficient (ICC) of .70. In white matter, it was 13.94 with an ICC of .30. Voxel-wise ICC and coefficient-of-variation maps showed relatively lower reliability in watershed areas and white matter especially in deeper white matter. The absolute mean rCBF values were consistent with the ones reported from PET, as was the relatively low variability in different feeding arteries. Thus, QUASAR reliability for regional perfusion is high within gray matter, but uncertain within white matter. © 2014 The Authors. Journal of Neuroimaging published by the American Society of Neuroimaging.

Regional Reliability of Quantitative Signal Targeting with Alternating Radiofrequency (STAR) Labeling of Arterial Regions (QUASAR)

PubMed Central

Tatewaki, Yasuko; Higano, Shuichi; Taki, Yasuyuki; Thyreau, Benjamin; Murata, Takaki; Mugikura, Shunji; Ito, Daisuke; Takase, Kei; Takahashi, Shoki

2014-01-01

BACKGROUND AND PURPOSE Quantitative signal targeting with alternating radiofrequency labeling of arterial regions (QUASAR) is a recent spin labeling technique that could improve the reliability of brain perfusion measurements. Although it is considered reliable for measuring gray matter as a whole, it has never been evaluated regionally. Here we assessed this regional reliability. METHODS Using a 3-Tesla Philips Achieva whole-body system, we scanned four times 10 healthy volunteers, in two sessions 2 weeks apart, to obtain QUASAR images. We computed perfusion images and ran a voxel-based analysis within all brain structures. We also calculated mean regional cerebral blood flow (rCBF) within regions of interest configured for each arterial territory distribution. RESULTS The mean CBF over whole gray matter was 37.74 with intraclass correlation coefficient (ICC) of .70. In white matter, it was 13.94 with an ICC of .30. Voxel-wise ICC and coefficient-of-variation maps showed relatively lower reliability in watershed areas and white matter especially in deeper white matter. The absolute mean rCBF values were consistent with the ones reported from PET, as was the relatively low variability in different feeding arteries. CONCLUSIONS Thus, QUASAR reliability for regional perfusion is high within gray matter, but uncertain within white matter. PMID:25370338

[Histomorphological analyse of accelerating the fibrocartilage layer repair of patella-patellar tendon junction in rabbits by low intensity pulsed ultrasound stimulation].

PubMed

Zhang, Baoliang; Lü, Hongbin; Hu, Jianzhong; Xu, Daqi; Zhou, Jingyong; Wang, Ye

2013-08-01

To analyse the effect of low intensity pulsed ultrasound stimulation (LIPUS) on accelerating the fibrocartilage layer repair of patella-patellar tendon junction. A total of 60 mature female New Zealand white rabbits undergoing standard partial patellectomy were divided into 2 groups randomly. The control group was given comfort treatment and the treatment group was given LIPUS treatment starting from day 3 to the end of week 6 postoperatively. The scheduled time points of animal euthanization would be at week 6, week 12 and week 18 postoperatively. The patella-patellar tendon (PPT) complex would be harvested and cut into sections after decalcification for H&E staining, Safranine o/fast green staining. The thickness and gray value of fibrocartilage layer were analyzed by SANO Microscope Partner image analyzer. At week 6, week 12 and week 18 postoperatively, the fibrocartilage layer in the treatment group was significantly thicker than that in the control group (P<0.01), and the gray value of fibrocartilage layer was significantly smaller than that in the control group (P<0.01). LIPUS helps to accelerate the fibrocartilage layer repair of patella-patellar tendon junction in rabbit models.

Experimental analysis of multivariate female choice in gray treefrogs (Hyla versicolor): evidence for directional and stabilizing selection.

PubMed

Gerhardt, H Carl; Brooks, Robert

2009-10-01

Even simple biological signals vary in several measurable dimensions. Understanding their evolution requires, therefore, a multivariate understanding of selection, including how different properties interact to determine the effectiveness of the signal. We combined experimental manipulation with multivariate selection analysis to assess female mate choice on the simple trilled calls of male gray treefrogs. We independently and randomly varied five behaviorally relevant acoustic properties in 154 synthetic calls. We compared response times of each of 154 females to one of these calls with its response to a standard call that had mean values of the five properties. We found directional and quadratic selection on two properties indicative of the amount of signaling, pulse number, and call rate. Canonical rotation of the fitness surface showed that these properties, along with pulse rate, contributed heavily to a major axis of stabilizing selection, a result consistent with univariate studies showing diminishing effects of increasing pulse number well beyond the mean. Spectral properties contributed to a second major axis of stabilizing selection. The single major axis of disruptive selection suggested that a combination of two temporal and two spectral properties with values differing from the mean should be especially attractive.

Nonlinear histogram binning for quantitative analysis of lung tissue fibrosis in high-resolution CT data

NASA Astrophysics Data System (ADS)

Zavaletta, Vanessa A.; Bartholmai, Brian J.; Robb, Richard A.

2007-03-01

Diffuse lung diseases, such as idiopathic pulmonary fibrosis (IPF), can be characterized and quantified by analysis of volumetric high resolution CT scans of the lungs. These data sets typically have dimensions of 512 x 512 x 400. It is too subjective and labor intensive for a radiologist to analyze each slice and quantify regional abnormalities manually. Thus, computer aided techniques are necessary, particularly texture analysis techniques which classify various lung tissue types. Second and higher order statistics which relate the spatial variation of the intensity values are good discriminatory features for various textures. The intensity values in lung CT scans range between [-1024, 1024]. Calculation of second order statistics on this range is too computationally intensive so the data is typically binned between 16 or 32 gray levels. There are more effective ways of binning the gray level range to improve classification. An optimal and very efficient way to nonlinearly bin the histogram is to use a dynamic programming algorithm. The objective of this paper is to show that nonlinear binning using dynamic programming is computationally efficient and improves the discriminatory power of the second and higher order statistics for more accurate quantification of diffuse lung disease.

Correction for partial volume effect in PET blood flow images

NASA Astrophysics Data System (ADS)

Gage, Howard D.; Fahey, Fredrick H.; Santago, Peter, II; Harkness, Beth A.; Keyes, J. W.

1996-04-01

Current positron emission tomography techniques for the measurement of cerebral blood flow assume that voxels represent pure material regions. In this work, a method is presented which utilizes anatomical information from a high resolution modality such as MRI in conjunction with a multicompartment extension of the Kety model to obtain intravoxel, tissue specific blood flow values. In order to evaluate the proposed method, noisy time activity curves (TACs) were simulated representing different combinations of gray matter, white matter and CSF, and ratios of gray to white matter blood flow. In all experiments it was assumed that registered MR data supplied the number of materials and the fraction of each present. For each TAC, three experiments were run. In the first it was assumed that the fraction of each material determined by MRI was correct, and, in the second two, that the value was either too high or too low. Using the tree annealing method, material flows were determined which gave the best fit of the model to the simulated TAC data. The results indicate that the accuracy of the method is approximately linearly related to the error in material fraction estimated for a voxel.

Shear velocity estimates on the inner shelf off Grays Harbor, Washington, USA

USGS Publications Warehouse

Sherwood, C.R.; Lacy, J.R.; Voulgaris, G.

2006-01-01

Shear velocity was estimated from current measurements near the bottom off Grays Harbor, Washington between May 4 and June 6, 2001 under mostly wave-dominated conditions. A downward-looking pulse-coherent acoustic Doppler profiler (PCADP) and two acoustic-Doppler velocimeters (field version; ADVFs) were deployed on a tripod at 9-m water depth. Measurements from these instruments were used to estimate shear velocity with (1) a modified eddy-correlation (EC) technique, (2) the log-profile (LP) method, and (3) a dissipation-rate method. Although values produced by the three methods agreed reasonably well (within their broad ranges of uncertainty), there were important systematic differences. Estimates from the EC method were generally lowest, followed by those from the inertial-dissipation method. The LP method produced the highest values and the greatest scatter. We show that these results are consistent with boundary-layer theory when sediment-induced stratification is present. The EC method provides the most fundamental estimate of kinematic stress near the bottom, and stratification causes the LP method to overestimate bottom stress. These results remind us that the methods are not equivalent and that comparison among sites and with models should be made carefully. ?? 2006 Elsevier Ltd. All rights reserved.

A scalable method to improve gray matter segmentation at ultra high field MRI.

PubMed

Gulban, Omer Faruk; Schneider, Marian; Marquardt, Ingo; Haast, Roy A M; De Martino, Federico

2018-01-01

High-resolution (functional) magnetic resonance imaging (MRI) at ultra high magnetic fields (7 Tesla and above) enables researchers to study how anatomical and functional properties change within the cortical ribbon, along surfaces and across cortical depths. These studies require an accurate delineation of the gray matter ribbon, which often suffers from inclusion of blood vessels, dura mater and other non-brain tissue. Residual segmentation errors are commonly corrected by browsing the data slice-by-slice and manually changing labels. This task becomes increasingly laborious and prone to error at higher resolutions since both work and error scale with the number of voxels. Here we show that many mislabeled, non-brain voxels can be corrected more efficiently and semi-automatically by representing three-dimensional anatomical images using two-dimensional histograms. We propose both a uni-modal (based on first spatial derivative) and multi-modal (based on compositional data analysis) approach to this representation and quantify the benefits in 7 Tesla MRI data of nine volunteers. We present an openly accessible Python implementation of these approaches and demonstrate that editing cortical segmentations using two-dimensional histogram representations as an additional post-processing step aids existing algorithms and yields improved gray matter borders. By making our data and corresponding expert (ground truth) segmentations openly available, we facilitate future efforts to develop and test segmentation algorithms on this challenging type of data.

A scalable method to improve gray matter segmentation at ultra high field MRI

PubMed Central

De Martino, Federico

2018-01-01

High-resolution (functional) magnetic resonance imaging (MRI) at ultra high magnetic fields (7 Tesla and above) enables researchers to study how anatomical and functional properties change within the cortical ribbon, along surfaces and across cortical depths. These studies require an accurate delineation of the gray matter ribbon, which often suffers from inclusion of blood vessels, dura mater and other non-brain tissue. Residual segmentation errors are commonly corrected by browsing the data slice-by-slice and manually changing labels. This task becomes increasingly laborious and prone to error at higher resolutions since both work and error scale with the number of voxels. Here we show that many mislabeled, non-brain voxels can be corrected more efficiently and semi-automatically by representing three-dimensional anatomical images using two-dimensional histograms. We propose both a uni-modal (based on first spatial derivative) and multi-modal (based on compositional data analysis) approach to this representation and quantify the benefits in 7 Tesla MRI data of nine volunteers. We present an openly accessible Python implementation of these approaches and demonstrate that editing cortical segmentations using two-dimensional histogram representations as an additional post-processing step aids existing algorithms and yields improved gray matter borders. By making our data and corresponding expert (ground truth) segmentations openly available, we facilitate future efforts to develop and test segmentation algorithms on this challenging type of data. PMID:29874295

78 FR 10122 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-13

... recreational sector's annual catch limits (ACLs) and annual catch targets (ACTs) for gray triggerfish; revise the recreational sector accountability measures (AMs) for gray triggerfish; revise the gray triggerfish recreational bag limit; establish a commercial trip limit for gray triggerfish; and establish a...

Cost Comparison of Conventional Gray Combined Sewer Overflow Control Infrastructure versus a Green/Gray Combination

EPA Science Inventory

This paper outlines a life-cycle cost analysis comparing a green (rain gardens) and gray (tunnels) infrastructure combination to a gray-only option to control combined sewer overflow in the Turkey Creek Combined Sewer Overflow Basin, in Kansas City, MO. The plan area of this Bas...

Gray Matter Features of Reading Disability: A Combined Meta-Analytic and Direct Analysis Approach1234

PubMed Central

Berninger, Virginia W.; Gebregziabher, Mulugeta; Tsu, Loretta

2016-01-01

Abstract Meta-analysis of voxel-based morphometry dyslexia studies and direct analysis of 293 reading disability and control cases from six different research sites were performed to characterize defining gray matter features of reading disability. These analyses demonstrated consistently lower gray matter volume in left posterior superior temporal sulcus/middle temporal gyrus regions and left orbitofrontal gyrus/pars orbitalis regions. Gray matter volume within both of these regions significantly predicted individual variation in reading comprehension after correcting for multiple comparisons. These regional gray matter differences were observed across published studies and in the multisite dataset after controlling for potential age and gender effects, and despite increased anatomical variance in the reading disability group, but were not significant after controlling for total gray matter volume. Thus, the orbitofrontal and posterior superior temporal sulcus gray matter findings are relatively reliable effects that appear to be dependent on cases with low total gray matter volume. The results are considered in the context of genetics studies linking orbitofrontal and superior temporal sulcus regions to alleles that confer risk for reading disability. PMID:26835509

Gray matter alterations and correlation of nutritional intake with the gray matter volume in prediabetes

PubMed Central

Hou, Yi-Cheng; Lai, Chien-Han; Wu, Yu-Te; Yang, Shwu-Huey

2016-01-01

Abstract The neurophysiology of prediabetes plays an important role in preventive medicine. The dysregulation of glucose metabolism is likely linked to changes in neuron-related gray matter. Therefore, we designed this study to investigate gray matter alterations in medication-naive prediabetic patients. We expected to find alterations in the gray matter of prediabetic patients. A total of 64 prediabetic patients and 54 controls were enrolled. All subjects received T1 scans using a 3-T magnetic resonance imaging machine. Subjects also completed nutritional intake records at the 24-hour and 3-day time points to determine their carbohydrate, protein, fat, and total calorie intake. We utilized optimized voxel-based morphometry to estimate the gray matter differences between the patients and controls. In addition, the preprandial serum glucose level and the carbohydrate, protein, fat, and total calorie intake levels were tested to determine whether these parameters were correlated with the gray matter volume. Prediabetic patients had lower gray matter volumes than controls in the right anterior cingulate gyrus, right posterior cingulate gyrus, left insula, left super temporal gyrus, and left middle temporal gyrus (corrected P < 0.05; voxel threshold: 33). Gray matter volume in the right anterior cingulate was also negatively correlated with the preprandial serum glucose level gyrus in a voxel-dependent manner (r = –0.501; 2-tailed P = 0.001). The cingulo-temporal and insula gray matter alterations may be associated with the glucose dysregulation in prediabetic patients. PMID:27336893

Differences in quantitative assessment of myocardial scar and gray zone by LGE-CMR imaging using established gray zone protocols.

PubMed

Mesubi, Olurotimi; Ego-Osuala, Kelechi; Jeudy, Jean; Purtilo, James; Synowski, Stephen; Abutaleb, Ameer; Niekoop, Michelle; Abdulghani, Mohammed; Asoglu, Ramazan; See, Vincent; Saliaris, Anastasios; Shorofsky, Stephen; Dickfeld, Timm

2015-02-01

Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging is the gold standard for myocardial scar evaluation. Heterogeneous areas of scar ('gray zone'), may serve as arrhythmogenic substrate. Various gray zone protocols have been correlated to clinical outcomes and ventricular tachycardia channels. This study assessed the quantitative differences in gray zone and scar core sizes as defined by previously validated signal intensity (SI) threshold algorithms. High quality LGE-CMR images performed in 41 cardiomyopathy patients [ischemic (33) or non-ischemic (8)] were analyzed using previously validated SI threshold methods [Full Width at Half Maximum (FWHM), n-standard deviation (NSD) and modified-FWHM]. Myocardial scar was defined as scar core and gray zone using SI thresholds based on these methods. Scar core, gray zone and total scar sizes were then computed and compared among these models. The median gray zone mass was 2-3 times larger with FWHM (15 g, IQR: 8-26 g) compared to NSD or modified-FWHM (5 g, IQR: 3-9 g; and 8 g. IQR: 6-12 g respectively, p < 0.001). Conversely, infarct core mass was 2.3 times larger with NSD (30 g, IQR: 17-53 g) versus FWHM and modified-FWHM (13 g, IQR: 7-23 g, p < 0.001). The gray zone extent (percentage of total scar that was gray zone) also varied significantly among the three methods, 51 % (IQR: 42-61 %), 17 % (IQR: 11-21 %) versus 38 % (IQR: 33-43 %) for FWHM, NSD and modified-FWHM respectively (p < 0.001). Considerable variability exists among the current methods for MRI defined gray zone and scar core. Infarct core and total myocardial scar mass also differ using these methods. Further evaluation of the most accurate quantification method is needed.

Synergistic Effects of Age on Patterns of White and Gray Matter Volume across Childhood and Adolescence1,2,3

PubMed Central

Krongold, Mark; Cooper, Cassandra; Lebel, Catherine

2015-01-01

Abstract The human brain develops with a nonlinear contraction of gray matter across late childhood and adolescence with a concomitant increase in white matter volume. Across the adult population, properties of cortical gray matter covary within networks that may represent organizational units for development and degeneration. Although gray matter covariance may be strongest within structurally connected networks, the relationship to volume changes in white matter remains poorly characterized. In the present study we examined age-related trends in white and gray matter volume using T1-weighted MR images from 360 human participants from the NIH MRI study of Normal Brain Development. Images were processed through a voxel-based morphometry pipeline. Linear effects of age on white and gray matter volume were modeled within four age bins, spanning 4-18 years, each including 90 participants (45 male). White and gray matter age-slope maps were separately entered into k-means clustering to identify regions with similar age-related variability across the four age bins. Four white matter clusters were identified, each with a dominant direction of underlying fibers: anterior–posterior, left–right, and two clusters with superior–inferior directions. Corresponding, spatially proximal, gray matter clusters encompassed largely cerebellar, fronto-insular, posterior, and sensorimotor regions, respectively. Pairs of gray and white matter clusters followed parallel slope trajectories, with white matter changes generally positive from 8 years onward (indicating volume increases) and gray matter negative (decreases). As developmental disorders likely target networks rather than individual regions, characterizing typical coordination of white and gray matter development can provide a normative benchmark for understanding atypical development. PMID:26464999

A western gray whale mitigation and monitoring program for a 3-D seismic survey, Sakhalin Island, Russia.

PubMed

Johnson, S R; Richardson, W J; Yazvenko, S B; Blokhin, S A; Gailey, G; Jenkerson, M R; Meier, S K; Melton, H R; Newcomer, M W; Perlov, A S; Rutenko, S A; Würsig, B; Martin, C R; Egging, D E

2007-11-01

The introduction of anthropogenic sounds into the marine environment can impact some marine mammals. Impacts can be greatly reduced if appropriate mitigation measures and monitoring are implemented. This paper concerns such measures undertaken by Exxon Neftegas Limited, as operator of the Sakhalin-1 Consortium, during the Odoptu 3-D seismic survey conducted during 17 August-9 September 2001. The key environmental issue was protection of the critically endangered western gray whale (Eschrichtius robustus), which feeds in summer and fall primarily in the Piltun feeding area off northeast Sakhalin Island. Existing mitigation and monitoring practices for seismic surveys in other jurisdictions were evaluated to identify best practices for reducing impacts on feeding activity by western gray whales. Two buffer zones were established to protect whales from physical injury or undue disturbance during feeding. A 1 km buffer protected all whales from exposure to levels of sound energy potentially capable of producing physical injury. A 4-5 km buffer was established to avoid displacing western gray whales from feeding areas. Trained Marine Mammal Observers (MMOs) on the seismic ship Nordic Explorer had the authority to shut down the air guns if whales were sighted within these buffers. Additional mitigation measures were also incorporated: Temporal mitigation was provided by rescheduling the program from June-August to August-September to avoid interference with spring arrival of migrating gray whales. The survey area was reduced by 19% to avoid certain waters <20 m deep where feeding whales concentrated and where seismic acquisition was a lower priority. The number of air guns and total volume of the air guns were reduced by about half (from 28 to 14 air guns and from 3,390 in(3) to 1,640 in(3)) relative to initial plans. "Ramp-up" (="soft-start") procedures were implemented. Monitoring activities were conducted as needed to implement some mitigation measures, and to assess residual impacts. Aerial and vessel-based surveys determined the distribution of whales before, during and after the seismic survey. Daily aerial reconnaissance helped verify whale-free areas and select the sequence of seismic lines to be surveyed. A scout vessel with MMOs aboard was positioned 4 km shoreward of the active seismic vessel to provide better visual coverage of the 4-5 km buffer and to help define the inshore edge of the 4-5 km buffer. A second scout vessel remained near the seismic vessel. Shore-based observers determined whale numbers, distribution, and behavior during and after the seismic survey. Acoustic monitoring documented received sound levels near and in the main whale feeding area. Statistical analyses of aerial survey data indicated that about 5-10 gray whales moved away from waters near (inshore of) the seismic survey during seismic operations. They shifted into the core gray whale feeding area farther south, and the proportion of gray whales observed feeding did not change over the study period. Five shutdowns of the air guns were invoked for gray whales seen within or near the buffer. A previously unknown gray whale feeding area (the Offshore feeding area) was discovered south and offshore from the nearshore Piltun feeding area. The Offshore area has subsequently been shown to be used by feeding gray whales during several years when no anthropogenic activity occurred near the Piltun feeding area.Shore-based counts indicated that whales continued to feed inshore of the Odoptu block throughout the seismic survey, with no significant correlation between gray whale abundance and seismic activity. Average values of most behavioral parameters were similar to those without seismic surveys. Univariate analysis showed no correlation between seismic sound levels and any behavioral parameter. Multiple regression analyses indicated that, after allowance for environmental covariates, 5 of 11 behavioral parameters were statistically correlated with estimated seismic survey-related variables; 6 of 11 behavioral parameters were not statistically correlated with seismic survey-related variables. Behavioral parameters that were correlated with seismic variables were transient and within the range of variation attributable to environmental effects. Acoustic monitoring determined that the 4-5 km buffer zone, in conjunction with reduction of the air gun array to 14 guns and 1,640 in(3), was effective in limiting sound exposure. Within the Piltun feeding area, these mitigation measures were designed to insure that western gray whales were not exposed to received levels exceeding the 163 dB re 1 microPa (rms) threshold. This was among the most complex and intensive mitigation programs ever conducted for any marine mammal. It provided valuable new information about underwater sounds and gray whale responses during a nearshore seismic program that will be useful in planning future work. Overall, the efforts in 2001 were successful in reducing impacts to levels tolerable by western gray whales. Research in 2002-2005 suggested no biologically significant or population-level impacts of the 2001 seismic survey.

Division within the North American boreal forest: Ecological niche divergence between the Bicknell's Thrush (Catharus bicknelli) and Gray-cheeked Thrush (C. minimus).

PubMed

FitzGerald, Alyssa M

2017-07-01

Sister species that diverged in allopatry in similar environments are expected to exhibit niche conservatism. Using ecological niche modeling and a multivariate analysis of climate and habitat data, I test the hypothesis that the Bicknell's Thrush ( Catharus bicknelli ) and Gray-cheeked Thrush ( C. mimimus ), sister species that breed in the North American boreal forest, show niche conservatism. Three tree species that are important components of breeding territories of both thrush species were combined with climatic variables to create niche models consisting of abiotic and biotic components. Abiotic-only, abiotic+biotic, and biotic-only models were evaluated using the area under the curve (AUC) criterion. Abiotic+biotic models had higher AUC scores and did not over-project thrush distributions compared to abiotic-only or biotic-only models. From the abiotic+biotic models, I tested for niche conservatism or divergence by accounting for the differences in the availability of niche components by calculating (1) niche overlap from ecological niche models and (2) mean niche differences of environmental values at occurrence points. Niche background similarity tests revealed significant niche divergence in 10 of 12 comparisons, and multivariate tests revealed niche divergence along 2 of 3 niche axes. The Bicknell's Thrush breeds in warmer and wetter regions with a high abundance of balsam fir ( Abies balsamea ), whereas Gray-cheeked Thrush often co-occurs with black spruce ( Picea mariana ). Niche divergence, rather than conservatism, was the predominant pattern for these species, suggesting that ecological divergence has played a role in the speciation of the Bicknell's Thrush and Gray-cheeked Thrush. Furthermore, because niche models were improved by the incorporation of biotic variables, this study validates the inclusion of relevant biotic factors in ecological niche modeling to increase model accuracy.

Pennation angle does not influence the age-related differences in echo intensity of the medial gastrocnemius.

PubMed

Ryan, Eric D; Rosenberg, Joseph G; Scharville, Michael J; Sobolewski, Eric J; Tweedell, Andrew J; Kleinberg, Craig R

2015-02-01

The reflection of an ultrasound (US) wave is strongest when the propagation direction of the wave is perpendicular to muscle fascicles. Thus, it is possible that muscle echo intensity (EI), a gray-scale US measure of muscle quality, may be influenced by the angulation of muscle fascicles. Therefore, the purpose of this study was to determine if age-related differences in muscle EI values are influenced by differences in pennation angle (PA). Medial gastrocnemius EI and PA were examined using panoramic US imaging in 24 young (19.8 ± 1.7 y) and 21 older (69.3 ± 3.3 y) men. The young men had lower EI values (young = 74.1 ± 6.3 a.u., older = 89.1 ± 8.8 a.u.) and a greater PA (young = 20.0 ± 2.9°; older = 17.2 ± 2.5°) compared with the older men (p < 0.01). In addition, there was a negative relationship (r = -0.473, p < 0.01) between PA and EI with both groups combined, but no significant relationship when the young (r = -0.334, p = 0.111) and older (r = -0.147, p = 0.525) men were examined separately. An analysis of covariance revealed that muscle EI values remained different (p < 0.01) between age groups after adjustment for differences in PA. Thus, after statistically adjusting the mean EI values for the differences in PA, there were still significant age-related differences in EI. These findings may provide further support that the age-related changes in muscle EI values reflect changes in tissue composition (i.e., increase in intramuscular fat and/or connective tissue) commonly reported in older adults. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Estimating stellar effective temperatures and detected angular parameters using stochastic particle swarm optimization

NASA Astrophysics Data System (ADS)

Zhang, Chuan-Xin; Yuan, Yuan; Zhang, Hao-Wei; Shuai, Yong; Tan, He-Ping

2016-09-01

Considering features of stellar spectral radiation and sky surveys, we established a computational model for stellar effective temperatures, detected angular parameters and gray rates. Using known stellar flux data in some bands, we estimated stellar effective temperatures and detected angular parameters using stochastic particle swarm optimization (SPSO). We first verified the reliability of SPSO, and then determined reasonable parameters that produced highly accurate estimates under certain gray deviation levels. Finally, we calculated 177 860 stellar effective temperatures and detected angular parameters using data from the Midcourse Space Experiment (MSX) catalog. These derived stellar effective temperatures were accurate when we compared them to known values from literatures. This research makes full use of catalog data and presents an original technique for studying stellar characteristics. It proposes a novel method for calculating stellar effective temperatures and detecting angular parameters, and provides theoretical and practical data for finding information about radiation in any band.

Video shot boundary detection using region-growing-based watershed method

NASA Astrophysics Data System (ADS)

Wang, Jinsong; Patel, Nilesh; Grosky, William

2004-10-01

In this paper, a novel shot boundary detection approach is presented, based on the popular region growing segmentation method - Watershed segmentation. In image processing, gray-scale pictures could be considered as topographic reliefs, in which the numerical value of each pixel of a given image represents the elevation at that point. Watershed method segments images by filling up basins with water starting at local minima, and at points where water coming from different basins meet, dams are built. In our method, each frame in the video sequences is first transformed from the feature space into the topographic space based on a density function. Low-level features are extracted from frame to frame. Each frame is then treated as a point in the feature space. The density of each point is defined as the sum of the influence functions of all neighboring data points. The height function that is originally used in Watershed segmentation is then replaced by inverting the density at the point. Thus, all the highest density values are transformed into local minima. Subsequently, Watershed segmentation is performed in the topographic space. The intuitive idea under our method is that frames within a shot are highly agglomerative in the feature space and have higher possibilities to be merged together, while those frames between shots representing the shot changes are not, hence they have less density values and are less likely to be clustered by carefully extracting the markers and choosing the stopping criterion.

The Effect of Changing Scan Mode on Trabecular Bone Score Using Lunar Prodigy.

PubMed

Chen, Weiwen; Slattery, Anthony; Center, Jacqueline; Pocock, Nicholas

2016-10-01

Trabecular bone score (TBS) is a measure of gray scale homogeneity that correlates with trabecular microarchitecture and is an independent predictor of fracture risk. TBS is being increasingly used in the assessment of patients at risk of osteoporosis and has recently been incorporated into FRAX ® . GE Lunar machines acquire spine scans using 1 of 3 acquisition modes depending on abdominal tissue thickness (thin, standard, and thick). From a database review, 30 patients (mean body mass index: 30.8, range 26.2-34.1) were identified who had undergone lumbar spine DXA scans (GE Lunar Prodigy, software 14.10; Lunar Radiation Corporation, Madison, WI) in both standard mode and thick mode, on the same day with no repositioning. Lumbar spine bone mineral density (L1-L4) and TBS were derived from the 30 paired spine scans. There was no significant difference in lumbar spine bone mineral density between the 2 scanning modes. There were, however, significant higher TBS values from the spine scans acquired in thick mode compared to the TBS values derived from spine acquisitions in standard mode (mean TBS difference: 0.24 [20%], standard deviation ±0.10). In conclusion, these preliminary data suggest that TBS values acquired in the GE Lunar Prodigy are dependent on the scanning mode used. Further evaluation is required to confirm the cause and develop appropriate protocols. Copyright © 2016 International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Building Consensus toward a Shared Purpose: A Profile of President David Gray

ERIC Educational Resources Information Center

Dessoff, Alan

2011-01-01

The author presents a profile of APPA president David Gray. One might say that David Gray's path into higher education facilities management was anything but traditional. Today, Gray is the assistant vice president of facilities services at Middle Tennessee State University. His professional career, however, actually began in banking. In 1993 he…