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Sample records for cells improves visual

  1. Oral messages improve visual search

    CERN Document Server

    Kieffer, Suzanne

    2007-01-01

    Input multimodality combining speech and hand gestures has motivated numerous usability studies. Contrastingly, issues relating to the design and ergonomic evaluation of multimodal output messages combining speech with visual modalities have not yet been addressed extensively. The experimental study presented here addresses one of these issues. Its aim is to assess the actual efficiency and usability of oral system messages including brief spatial information for helping users to locate objects on crowded displays rapidly. Target presentation mode, scene spatial structure and task difficulty were chosen as independent variables. Two conditions were defined: the visual target presentation mode (VP condition) and the multimodal target presentation mode (MP condition). Each participant carried out two blocks of visual search tasks (120 tasks per block, and one block per condition). Scene target presentation mode, scene structure and task difficulty were found to be significant factors. Multimodal target presenta...

  2. Color improves "visual" acuity via sound.

    Science.gov (United States)

    Levy-Tzedek, Shelly; Riemer, Dar; Amedi, Amir

    2014-01-01

    Visual-to-auditory sensory substitution devices (SSDs) convey visual information via sound, with the primary goal of making visual information accessible to blind and visually impaired individuals. We developed the EyeMusic SSD, which transforms shape, location, and color information into musical notes. We tested the "visual" acuity of 23 individuals (13 blind and 10 blindfolded sighted) on the Snellen tumbling-E test, with the EyeMusic. Participants were asked to determine the orientation of the letter "E." The test was repeated twice: in one test, the letter "E" was drawn with a single color (white), and in the other test, with two colors (red and white). In the latter case, the vertical line in the letter, when upright, was drawn in red, with the three horizontal lines drawn in white. We found no significant differences in performance between the blind and the sighted groups. We found a significant effect of the added color on the "visual" acuity. The highest acuity participants reached in the monochromatic test was 20/800, whereas with the added color, acuity doubled to 20/400. We conclude that color improves "visual" acuity via sound. PMID:25426015

  3. Magnocellular training improves visual word recognition.

    Science.gov (United States)

    Chouake, Tara; Levy, Tamar; Javitt, Daniel C; Lavidor, Michal

    2012-01-01

    Current research has shown that basic visual networks, such as the magnocellular system, may play a crucial role in reading deficits related to dyslexia. The current study explored the relationship between magnocellular activity and reading abilities; we examined the hypothesis that a repeated usage of the magnocellular stream may improve reading by strengthening crucial neural pathways. Visual training was conducted for five consecutive days using a motion detection task (magnocellular training) and a control task of pattern detection (parvocellular training). Reading abilities of skilled readers were measured before and after the training using a lexical decision task. It was found that low-grade visual training overall can improve speed of lexical decision, but there is some indication that magnocellular training may selectively relate to accuracy. This potential added benefit of accuracy is crucial, and indicates that magnocellular training may have an advantage to parvocellular or general visual training when it comes to reading. This result lends support to the role of basic visual systems in reading, and has potential implications for neurorehabilitation of reading-related deficits. PMID:22363277

  4. Improved visual cognition through stroboscopic training

    Directory of Open Access Journals (Sweden)

    Lawrence Gregory eAppelbaum

    2011-10-01

    Full Text Available Humans have a remarkable capacity to learn and adapt, but surprisingly little research has demonstrated generalized learning in which new skills and strategies can be used flexibly across a range of tasks and contexts. In the present work we examined whether generalized learning could result from visual-motor training under stroboscopic visual conditions. Individuals were assigned to either an experimental condition that trained with stroboscopic eyewear or to a control condition that underwent identical training with non-stroboscopic eyewear. The training consisted of multiple sessions of athletic activities during which participants performed simple drills such as throwing and catching. To determine if training led to generalized cognitive benefits, we used computerized measures to assess perceptual and cognitive abilities on a variety of tasks before and after training. Computer-based assessments included measures of visual sensitivity (central and peripheral motion coherence thresholds, transient spatial attention (a useful field of view – dual task paradigm, and sustained attention (multiple-object tracking. Results revealed that stroboscopic training led to significantly greater re-test improvement in central visual field motion sensitivity and transient attention abilities. No training benefits were observed for peripheral motion sensitivity or peripheral transient attention abilities, nor were benefits seen for sustained multiple-object tracking suggesting that stroboscopic training can effectively improve some, but not all aspects of visual perception and attention.

  5. Aged human bone marrow stromal cells maintaining bone forming capacity in vivo evaluated using an improved method of visualization

    DEFF Research Database (Denmark)

    Stenderup, Karin; Rosada, Cecilia; Justesen, J;

    2004-01-01

    weeks, the implants were removed and embedded un-decalcified in methyl methacrylate (MMA). Sections were stained histochemically with Goldner's Trichrome stain and immuno-histochemically using human-specific antibodies against known osteogenic markers. Implanted human marrow stromal cells (hMSC) were...... able to form bone in vivo. The donor origin of bone was verified using several human-specific antibodies. Dose-response experiments demonstrated that 5 x 10(5) hMSC per implant gave the maximal bone formation after 8 weeks. No difference in BFC was observed between cells obtained from young (24...... vivo assay for quantifying the bone forming capacity (BFC) and we compared the BFC of osteoblastic cells obtained from young and old donors. Osteoblasts were obtained from human bone marrow stromal cell cultures and implanted subcutaneously in immuno-deficient mice (NOD/LtSz- Prkdc(scid)). After 8...

  6. Improving Visualization Skills in Engineering Education

    OpenAIRE

    Contero, Manuel; Company, Pedro; José Luis SAORÍN PÉREZ; Naya, Ferran; Conesa, Julián

    2005-01-01

    This article analyzes the importance of visualization skills in engineering education. It proposes a dual approach based on computer graphics applications using both Web-based graphic applications and a sketch based modeling system. It addresses the importance of spatial abilities in the context of engineering education and the available techniques for evaluating these abilities from a psychological point of view. It then reviews some Web resources conceived to help students improve their spa...

  7. Magnocellular training improves visual word recognition

    Directory of Open Access Journals (Sweden)

    Tara Chouake

    2012-02-01

    Full Text Available Current research has shown that the magnocellular system may play a crucial role in reading deficits related to dyslexia. The current study explored the relationship between magnocellular activity and reading abilities; we examined the hypothesis that a repeated usage of the magnocellular stream may improve reading by strengthening crucial neural pathways. Visual training was conducted for five consecutive days using a motion detection task (magnocellular training and a control task of pattern detection (parvocellular training. Reading abilities of skilled readers were measured before and after the training using a lexical decision task. It was found that low grade visual training overall can improve speed of lexical decision, but only magnocellular training selectively improved accuracy. Improvement in the magnocellular training task predicted performance on adjacent anagram and word recognition after training. In contrast, in the control group (parvocellular training degree of improvement in training did not predict lexical decision performance after training. This result lends support to the role of the magnocellular system in reading, and has potential implications for neuro-rehabilitation of reading related deficits.

  8. Perceptual learning in children with visual impairment improves near visual acuity

    NARCIS (Netherlands)

    Huurneman, B.; Boonstra, F.N.; Cox, R.F.; Rens, G. van; Cillessen, A.H.

    2013-01-01

    PURPOSE: This study investigated whether visual perceptual learning can improve near visual acuity and reduce foveal crowding effects in four- to nine-year-old children with visual impairment. METHODS: Participants were 45 children with visual impairment and 29 children with normal vision. Children

  9. Perceptual Learning in Children With Visual Impairment Improves Near Visual Acuity

    NARCIS (Netherlands)

    Huurneman, Bianca; Boonstra, F. Nienke; Cox, Ralf F. A.; van Rens, Ger; Cillessen, Antonius H. N.

    2013-01-01

    PURPOSE. This study investigated whether visual perceptual learning can improve near visual acuity and reduce foveal crowding effects in four-to nine-year-old children with visual impairment. METHODS. Participants were 45 children with visual impairment and 29 children with normal vision. Children w

  10. Perceptual Learning in Children With Visual Impairment Improves Near Visual Acuity

    OpenAIRE

    Huurneman, B.; Boonstra, F.N.; Cox, R.F.A.; van Rens, G. H M B; Cillessen, A.H.N.

    2013-01-01

    PURPOSE. This study investigated whether visual perceptual learning can improve near visual acuity and reduce foveal crowding effects in four-to nine-year-old children with visual impairment. METHODS. Participants were 45 children with visual impairment and 29 children with normal vision. Children with visual impairment were divided into three groups: a magnifier group (n = 12), a crowded perceptual learning group (n = 18), and an uncrowded perceptual learning group (n = 15). Children with no...

  11. A New Visual Stimulation Program for Improving Visual Acuity in Children with Visual Impairment: A Pilot Study

    OpenAIRE

    Tsai, Li-Ting; Hsu, Jung-Lung; Wu, Chien-Te; Chen, Chia-Ching; Su, Yu-Chin

    2016-01-01

    The purpose of this study was to investigate the effectiveness of visual rehabilitation of a computer-based visual stimulation (VS) program combining checkerboard pattern reversal (passive stimulation) with oddball stimuli (attentional modulation) for improving the visual acuity (VA) of visually impaired (VI) children and children with amblyopia and additional developmental problems. Six children (three females, three males; mean age = 3.9 ± 2.3 years) with impaired VA caused by deficits alon...

  12. Successful Computer-based Visual Training Specifically Predicts Visual Memory Enhancement over Verbal Memory Improvement in Schizophrenia

    OpenAIRE

    Surti, Toral S.; Corbera, Silvia; Bella, Morris D.; Wexler, Bruce E.

    2011-01-01

    We investigated whether improved early visual processing on cognitive remediation (CR) exercises generalizes to visual and auditory learning and information manipulation in schizophrenia. Fourteen participants received neuropsychological testing before and after CR consisting of visual, auditory and cognitive control training. Achievement on visual training exercises was strongly and significantly correlated with improved visual learning, but not improved verbal learning or increased ability ...

  13. Visualizing cell state transition using Raman spectroscopy.

    Directory of Open Access Journals (Sweden)

    Taro Ichimura

    Full Text Available System level understanding of the cell requires detailed description of the cell state, which is often characterized by the expression levels of proteins. However, understanding the cell state requires comprehensive information of the cell, which is usually obtained from a large number of cells and their disruption. In this study, we used Raman spectroscopy, which can report changes in the cell state without introducing any label, as a non-invasive method with single cell capability. Significant differences in Raman spectra were observed at the levels of both the cytosol and nucleus in different cell-lines from mouse, indicating that Raman spectra reflect differences in the cell state. Difference in cell state was observed before and after the induction of differentiation in neuroblastoma and adipocytes, showing that Raman spectra can detect subtle changes in the cell state. Cell state transitions during embryonic stem cell (ESC differentiation were visualized when Raman spectroscopy was coupled with principal component analysis (PCA, which showed gradual transition in the cell states during differentiation. Detailed analysis showed that the diversity between cells are large in undifferentiated ESC and in mesenchymal stem cells compared with terminally differentiated cells, implying that the cell state in stem cells stochastically fluctuates during the self-renewal process. The present study strongly indicates that Raman spectral morphology, in combination with PCA, can be used to establish cells' fingerprints, which can be useful for distinguishing and identifying different cellular states.

  14. Improved discrimination of visual stimuli following repetitive transcranial magnetic stimulation.

    Directory of Open Access Journals (Sweden)

    Michael L Waterston

    Full Text Available BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS at certain frequencies increases thresholds for motor-evoked potentials and phosphenes following stimulation of cortex. Consequently rTMS is often assumed to introduce a "virtual lesion" in stimulated brain regions, with correspondingly diminished behavioral performance. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigated the effects of rTMS to visual cortex on subjects' ability to perform visual psychophysical tasks. Contrary to expectations of a visual deficit, we find that rTMS often improves the discrimination of visual features. For coarse orientation tasks, discrimination of a static stimulus improved consistently following theta-burst stimulation of the occipital lobe. Using a reaction-time task, we found that these improvements occurred throughout the visual field and lasted beyond one hour post-rTMS. Low-frequency (1 Hz stimulation yielded similar improvements. In contrast, we did not find consistent effects of rTMS on performance in a fine orientation discrimination task. CONCLUSIONS/SIGNIFICANCE: Overall our results suggest that rTMS generally improves or has no effect on visual acuity, with the nature of the effect depending on the type of stimulation and the task. We interpret our results in the context of an ideal-observer model of visual perception.

  15. Visualization of DNA damage in individual cells

    International Nuclear Information System (INIS)

    A simple technique of micro-agarose gel electrophoresis has been developed to permit an evaluation of DNA damage in individual cells. Cells are embeded in agarose gel on microscope slides, lysed by detergents and then electrophoresed for a short time. In damaged cells, DNA migrated from the nuclei toward the anode, displaying 'comets' visualized by staining with a DNA-specific fluorochrome, acridine orange. The technique was applicable to quantifying DNA damage in individual cells exposed to Gy level of reactor radiation. (author)

  16. Short-term visual deprivation improves the perception of harmonicity.

    Science.gov (United States)

    Landry, Simon P; Shiller, Douglas M; Champoux, François

    2013-12-01

    Neuroimaging studies have shown that the perception of auditory stimuli involves occipital cortical regions traditionally associated with visual processing, even in the absence of any overt visual component to the task. Analogous behavioral evidence of an interaction between visual and auditory processing during purely auditory tasks comes from studies of short-term visual deprivation on the perception of auditory cues, however, the results of such studies remain equivocal. Although some data have suggested that visual deprivation significantly increases loudness and pitch discrimination and reduces spatial localization inaccuracies, it is still unclear whether such improvement extends to the perception of spectrally complex cues, such as those involved in speech and music perception. We present data demonstrating that a 90-min period of visual deprivation causes a transient improvement in the perception of harmonicity: a spectrally complex cue that plays a key role in music and speech perception. The results provide clear behavioral evidence supporting a role for the visual system in the processing of complex auditory stimuli, even in the absence of any visual component to the task. PMID:23957309

  17. Qualitative visual trichotomous assessment improves the value of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in predicting the prognosis of diffuse large B-cell lymphoma

    Institute of Scientific and Technical Information of China (English)

    Xu Zhang; Wei Fan; Ying-Ying Hu; Zhi-Ming Li; Zhong-Jun Xia; Xiao-Ping Lin; Ya-Rui Zhang; Pei-Yan Liang; Yuan-Hua Li

    2015-01-01

    Introduction:Fluorine-18 fluorodeoxyglucose (18 F-FDG) positron emission tomography/computed tomography (PET/CT) is a powerful tool for monitoring the response of diffuse large B-cell lymphoma (DLBCL) to therapy, but the criteria to interpret PET/CT results remain under debate. We investigated the value of post-treatment PET/CT in predicting the prognosis of DLBCL patients when interpreted according to qualitative visual trichotomous assessment (QVTA) criteria compared with the Deauvil e criteria. Methods:In this retrospective study, final PET/CT scans of DLBCL patients treated with rituximab-based regimens between October 2005 and November 2010 were interpreted using the Deauvil e and QVTA criteria. Survival curves were estimated using Kaplan-Meier analysis and compared using the log-rank test. Results:A total of 253 patients were enrol ed. The interpretation according to the Deauvil e criteria revealed that 181 patients had negative PET/CT scan results and 72 had positive results. The 3 year overal survival (OS) rate was significantly higher in patients with negative scan results than in those with positive results (91.6%vs. 57.5%, P<0.001). The 72 patients with positive scan results according to the Deauville criteria were divided into two groups by the interpretation according to the QVTA criteria:29 had indeterminate results, and 43 had positive results. The 3 year OS rate was significantly higher in patients with indeterminate scan results than in those with positive results (91.2%vs. 33.5%, P<0.001) but was similar between patients with negative and indeterminate scan results (91.6%vs. 91.2%, P=0.921). Conclusions:Compared with the Deauvil e criteria, using the QVTA criteria for interpreting post-treatment PET/CT scans of DLBCL patients is likely to reduce the number of false positive results. The QVTA criteria are feasible for therapeutic outcome evaluation and can be used to guide risk-adapted therapy.

  18. Improved portable lighting for visual aircraft inspection

    Energy Technology Data Exchange (ETDEWEB)

    Shagam, R.N. [Sandia National Lab., Albuquerque, NM (United States); Lerner, J.; Shie, R. [Physical Optics Corp., Torrance, CA (United States)

    1995-04-01

    The most common tool used by aircraft inspectors is the personal flashlight. While it is compact and very portable, it is generally typified by poor beam quality which can interfere with the ability for an inspector to detect small defects and anomalies, such as cracks and corrosion sites, which may be indicators of major structural problems. A Light Shaping Diffuser{trademark} (LSD) installed in a stock flashlight as a replacement to the lens can improve the uniformity of an average flashlight and improve the quality of the inspection. Field trials at aircraft maintenance facilities have demonstrated general acceptance of the LSD by aircraft inspection and maintenance personnel.

  19. Improved portable lighting for visual aircraft inspection

    Science.gov (United States)

    Shagam, Richard N.; Lerner, Jeremy M.; Shie, Rick

    1995-07-01

    The most common tool used by aircraft inspectors is the personal flashlight. While it is compact and very portable, it is generally typified by poor beam quality which can interfere with the ability for an inspector to detect small defects and anomalies, such as cracks and corrosion sites, which may be indicators of major structural problems. A Light Shaping Diffuser TM (LSD) installed in a stock flashlight as a replacement to the lens can improve the uniformity of an average flashlight and improve the quality of the inspection. Field trials at aircraft maintenance facilities have demonstrated general acceptance of the LSD by aircraft inspection and maintenance personnel.

  20. Improved visualization of lung metastases at single cell resolution in mice by combined in-situ perfusion of lung tissue and X-Gal staining of lacZ-tagged tumor cells.

    Science.gov (United States)

    Arlt, Matthias J E; Born, Walter; Fuchs, Bruno

    2012-01-01

    Metastasis is the main cause of death in the majority of cancer types and consequently a main focus in cancer research. However, the detection of micrometastases by radiologic imaging and the success in their therapeutic eradication remain limited. While animal models have proven to be invaluable tools for cancer research, the monitoring/visualization of micrometastases remains a challenge and inaccurate evaluation of metastatic spread in preclinical studies potentially leads to disappointing results in clinical trials. Consequently, there is great interest in refining the methods to finally allow reproducible and reliable detection of metastases down to the single cell level in normal tissue. The main focus therefore is on techniques, which allow the detection of tumor cells in vivo, like micro-computer tomography (micro-CT), positron emission tomography (PET), bioluminescence or fluorescence imaging. We are currently optimizing these techniques for in vivo monitoring of primary tumor growth and metastasis in different osteosarcoma models. Some of these techniques can also be used for ex vivo analysis of metastasis beside classical methods like qPCR, FACS or different types of histological staining. As a benchmark, we have established in the present study the stable transfection or transduction of tumor cells with the lacZ gene encoding the bacterial enzyme β-galactosidase that metabolizes the chromogenic substrate 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal) to an insoluble indigo blue dye and allows highly sensitive and selective histochemical blue staining of tumor cells in mouse tissue ex vivo down to the single cell level as shown here. This is a low-cost and not equipment-intensive tool, which allows precise validation of metastasis in studies assessing new anticancer therapies. A limiting factor of X-gal staining is the low contrast to e.g. blood-related red staining of well vascularized tissues. In lung tissue this problem can be solved by

  1. Collaborative Graphic Rendering for Improving Visual Experience

    Science.gov (United States)

    Wu, Xiaoxin; Pei, Guodong

    Handheld devices such as UMPC, though convenient, bear weakness of size constraint for display. To mitigate such a problem and enhance user experience for owners of small devices, in this paper we design a collaborative rendering platform. When running game graphic applications at a handheld, the generated OpenGL graphic commands are intercepted and then delivered to a device with a larger display. The graphics are rendered and displayed at that device. The performance of the collaborative rendering platform is determined by graphic computing resources and network bandwidth. Analysis and simulation prove that other than providing a better display, the collaborative system can improve game experience also by increasing frame rates. In particular, at a low computing cost, a further collaboration between GPUs of collaborators can improve frame rate by eliminating the negative impact from network delay on applications that require GPU feedback.

  2. Non-linear image blending improves visualization of head and neck primary squamous cell carcinoma compared to linear blending in dual-energy CT

    International Nuclear Information System (INIS)

    Aim: To compare non-linear and linear image-blending post-processing techniques in dual-energy CT (DECT) of primary head and neck squamous cell carcinoma (SCC) regarding subjective and objective image quality. Materials and methods: Head and neck DECT studies from 69 patients (48 male, 21 female; mean age 62.3 years) were retrospectively evaluated. All tumour lesions were histologically confirmed SCC. Linearly blended 80/140 kVp images series with varying weighting factors of 0.3 (M0.3), 0.6 and 0.8 were compared with non-linearly blended images. Attenuation of tumour lesion, various soft-tissue structures, the internal jugular vein, and image noise were measured, tumour signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Overall image quality, delineation of tumour lesion, image sharpness, and noise level were rated individually by three radiologists using five-point Likert scales. Interobserver agreement was calculated using intraclass correlation coefficient (ICC). Results: Enhancement of tumour lesions (non-linear, 137.5 ± 20.1 HU; M0.3, 92.7 ± 14.4 HU; M0.6, 110 ± 15.4 HU; M0.8, 123 ± 18.2 HU), CNR (non-linear, 12 ± 8; M0.3, 4 ± 4.7; M0.6, 7.5 ± 5.5; M0.8, 8 ± 5.5), subjective overall image quality and tumour delineation were significantly increased (all p < 0.001) with the non-linear blending technique compared to all investigated linear blending weighting factors. Overall interobserver agreement was substantial (ICC 0.70; 95% CI: 0.66–0.73). Conclusion: Post-processing of DECT using a non-linear blending technique provides improved objective and subjective image quality of head and neck SCC compared to linearly blended images series. - Highlights: • Non-linearly blended and linearly blended images series of DECT were compared. • Non-linear blending provides superior tumor attenuation and contrast-to-noise ratio of head and neck squamous cell carcinoma. • Non-linear blending provides superior

  3. Visual Aids Improve Diagnostic Inferences and Metacognitive Judgment Calibration

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    Rocio eGarcia-Retamero

    2015-07-01

    Full Text Available Visual aids can improve comprehension of risks associated with medical treatments, screenings, and lifestyles. Do visual aids also help decision makers accurately assess their risk comprehension? That is, do visual aids help them become well calibrated? To address these questions, we investigated the benefits of visual aids displaying numerical information and measured accuracy of self-assessment of diagnostic inferences (i.e., metacognitive judgment calibration controlling for individual differences in numeracy. Participants included 108 patients who made diagnostic inferences about three medical tests on the basis of information about the sensitivity and false-positive rate of the tests and disease prevalence. Half of the patients received the information in numbers without a visual aid, while the other half received numbers along with a grid representing the numerical information. In the numerical condition, many patients --especially those with low numeracy-- misinterpreted the predictive value of the tests and profoundly overestimated the accuracy of their inferences. Metacognitive judgment calibration mediated the relationship between numeracy and accuracy of diagnostic inferences. In contrast, in the visual aid condition, patients at all levels of numeracy showed high-levels of inferential accuracy and metacognitive judgment calibration. Results indicate that accurate metacognitive assessment may explain the beneficial effects of visual aids and numeracy --a result that accords with theory suggesting that metacognition is an essential part of risk literacy. We conclude that well-designed risk communications can inform patients about health-relevant numerical information while helping them assess the quality of their own risk comprehension.

  4. Perceptual Training Strongly Improves Visual Motion Perception in Schizophrenia

    Science.gov (United States)

    Norton, Daniel J.; McBain, Ryan K.; Ongur, Dost; Chen, Yue

    2011-01-01

    Schizophrenia patients exhibit perceptual and cognitive deficits, including in visual motion processing. Given that cognitive systems depend upon perceptual inputs, improving patients' perceptual abilities may be an effective means of cognitive intervention. In healthy people, motion perception can be enhanced through perceptual learning, but it…

  5. A New Visual Stimulation Program for Improving Visual Acuity in Children with Visual Impairment: A Pilot Study

    Science.gov (United States)

    Tsai, Li-Ting; Hsu, Jung-Lung; Wu, Chien-Te; Chen, Chia-Ching; Su, Yu-Chin

    2016-01-01

    The purpose of this study was to investigate the effectiveness of visual rehabilitation of a computer-based visual stimulation (VS) program combining checkerboard pattern reversal (passive stimulation) with oddball stimuli (attentional modulation) for improving the visual acuity (VA) of visually impaired (VI) children and children with amblyopia and additional developmental problems. Six children (three females, three males; mean age = 3.9 ± 2.3 years) with impaired VA caused by deficits along the anterior and/or posterior visual pathways were recruited. Participants received eight rounds of VS training (two rounds per week) of at least eight sessions per round. Each session consisted of stimulation with 200 or 300 pattern reversals. Assessments of VA (assessed with the Lea symbol VA test or Teller VA cards), visual evoked potential (VEP), and functional vision (assessed with the Chinese-version Functional Vision Questionnaire, FVQ) were carried out before and after the VS program. Significant gains in VA were found after the VS training [VA = 1.05 logMAR ± 0.80 to 0.61 logMAR ± 0.53, Z = –2.20, asymptotic significance (2-tailed) = 0.028]. No significant changes were observed in the FVQ assessment [92.8 ± 12.6 to 100.8 ±SD = 15.4, Z = –1.46, asymptotic significance (2-tailed) = 0.144]. VEP measurement showed improvement in P100 latency and amplitude or integration of the waveform in two participants. Our results indicate that a computer-based VS program with passive checkerboard stimulation, oddball stimulus design, and interesting auditory feedback could be considered as a potential intervention option to improve the VA of a wide age range of VI children and children with impaired VA combined with other neurological disorders. PMID:27148014

  6. A new visual stimulation program for improving visual acuity in children with visual impairment: a pilot study

    Directory of Open Access Journals (Sweden)

    Li-Ting eTsai

    2016-04-01

    Full Text Available The purpose of this study was to investigate the effectiveness of visual rehabilitation of a computer-based visual stimulation (VS program combining checkerboard pattern reversal (passive stimulation with oddball stimuli (attentional modulation for improving the visual acuity (VA of visually impaired (VI children and children with amblyopia and additional developmental problems. Six children (3 females, 3 males; mean age = 3.9 ± 2.3 years with impaired VA caused by deficits along the anterior and/or posterior visual pathways were recruited. Participants received eight rounds of VS training (two rounds per week of at least 8 sessions per round. Each session consisted of stimulation with 200 or 300 pattern reversals. Assessments of VA (assessed with the Lea symbol VA test or Teller VA cards, visual evoked potential (VEP, and functional vision (assessed with the Chinese-version Functional Vision Questionnaire, FVQ were carried out before and after the VS program. Significant gains in VA were found after the VS training (VA=1.05 logMAR ± 0.80 to 0.61 logMAR ± 0.53, Z=-2.20, asymptotic significance (2-tailed =0.028. No significant changes were observed in the FVQ assessment (92.8 ± 12.6 to 100.8 ± SD=15.4, Z=-1.46, asymptotic significance (2-tailed = 0.144. VEP measurement showed improvement in P100 latency and amplitude or integration of the waveform in two participants. Our results indicate that a computer-based VS program with passive checkerboard stimulation, oddball stimulus design, and interesting auditory feedback could be considered as a potential intervention option to improve the VA of a wide age range of VI children and children with impaired VA combined with other neurological disorders.

  7. A New Visual Stimulation Program for Improving Visual Acuity in Children with Visual Impairment: A Pilot Study.

    Science.gov (United States)

    Tsai, Li-Ting; Hsu, Jung-Lung; Wu, Chien-Te; Chen, Chia-Ching; Su, Yu-Chin

    2016-01-01

    The purpose of this study was to investigate the effectiveness of visual rehabilitation of a computer-based visual stimulation (VS) program combining checkerboard pattern reversal (passive stimulation) with oddball stimuli (attentional modulation) for improving the visual acuity (VA) of visually impaired (VI) children and children with amblyopia and additional developmental problems. Six children (three females, three males; mean age = 3.9 ± 2.3 years) with impaired VA caused by deficits along the anterior and/or posterior visual pathways were recruited. Participants received eight rounds of VS training (two rounds per week) of at least eight sessions per round. Each session consisted of stimulation with 200 or 300 pattern reversals. Assessments of VA (assessed with the Lea symbol VA test or Teller VA cards), visual evoked potential (VEP), and functional vision (assessed with the Chinese-version Functional Vision Questionnaire, FVQ) were carried out before and after the VS program. Significant gains in VA were found after the VS training [VA = 1.05 logMAR ± 0.80 to 0.61 logMAR ± 0.53, Z = -2.20, asymptotic significance (2-tailed) = 0.028]. No significant changes were observed in the FVQ assessment [92.8 ± 12.6 to 100.8 ±SD = 15.4, Z = -1.46, asymptotic significance (2-tailed) = 0.144]. VEP measurement showed improvement in P100 latency and amplitude or integration of the waveform in two participants. Our results indicate that a computer-based VS program with passive checkerboard stimulation, oddball stimulus design, and interesting auditory feedback could be considered as a potential intervention option to improve the VA of a wide age range of VI children and children with impaired VA combined with other neurological disorders. PMID:27148014

  8. Development of an autonomous biological cell manipulator with single-cell electroporation and visual servoing capabilities.

    Science.gov (United States)

    Sakaki, Kelly; Dechev, Nikolai; Burke, Robert D; Park, Edward J

    2009-08-01

    Studies of single cells via microscopy and microinjection are a key component in research on gene functions, cancer, stem cells, and reproductive technology. As biomedical experiments become more complex, there is an urgent need to use robotic systems to improve cell manipulation and microinjection processes. Automation of these tasks using machine vision and visual servoing creates significant benefits for biomedical laboratories, including repeatability of experiments, higher throughput, and improved cell viability. This paper presents the development of a new 5-DOF robotic manipulator, designed for manipulating and microinjecting single cells. This biological cell manipulator (BCM) is capable of autonomous scanning of a cell culture followed by autonomous injection of cells using single-cell electroporation (SCE). SCE does not require piercing the cell membrane, thereby keeping the cell membrane fully intact. The BCM features high-precision 3-DOF translational and 2-DOF rotational motion, and a second z-axis allowing top-down placement of a micropipette tip onto the cell membrane for SCE. As a technical demonstration, the autonomous visual servoing and microinjection capabilities of the single-cell manipulator are experimentally shown using sea urchin eggs. PMID:19605307

  9. Improved Visualization of Cartilage Canals Using Quantitative Susceptibility Mapping.

    Directory of Open Access Journals (Sweden)

    Mikko J Nissi

    Full Text Available Cartilage canal vessels are critical to the normal function of epiphyseal (growth cartilage and damage to these vessels is demonstrated or suspected in several important developmental orthopaedic diseases. High-resolution, three-dimensional (3-D visualization of cartilage canals has recently been demonstrated using susceptibility weighted imaging (SWI. In the present study, a quantitative susceptibility mapping (QSM approach is evaluated for 3-D visualization of the cartilage canals. It is hypothesized that QSM post-processing improves visualization of the cartilage canals by resolving artifacts present in the standard SWI post-processing while retaining sensitivity to the cartilage canals.Ex vivo distal femoral specimens from 3- and 8-week-old piglets and a 1-month-old human cadaver were scanned at 9.4 T with a 3-D gradient recalled echo sequence suitable for SWI and QSM post-processing. The human specimen and the stifle joint of a live, 3-week-old piglet also were scanned at 7.0 T. Datasets were processed using the standard SWI method and truncated k-space division QSM approach. To compare the post-processing methods, minimum/maximum intensity projections and 3-D reconstructions of the processed datasets were generated and evaluated.Cartilage canals were successfully visualized using both SWI and QSM approaches. The artifactual splitting of the cartilage canals that occurs due to the dipolar phase, which was present in the SWI post-processed data, was eliminated by the QSM approach. Thus, orientation-independent visualization and better localization of the cartilage canals was achieved with the QSM approach. Combination of GRE with a mask based on QSM data further improved visualization.Improved and artifact-free 3-D visualization of the cartilage canals was demonstrated by QSM processing of the data, especially by utilizing susceptibility data as an enhancing mask. Utilizing tissue-inherent contrast, this method allows noninvasive assessment

  10. Seeing Cells: Teaching the Visual/Verbal Rhetoric of Biology

    Science.gov (United States)

    Dinolfo, John; Heifferon, Barbara; Temesvari, Lesly A.

    2007-01-01

    This pilot study obtained baseline information on verbal and visual rhetorics to teach microscopy techniques to college biology majors. We presented cell images to students in cell biology and biology writing classes and then asked them to identify textual, verbal, and visual cues that support microscopy learning. Survey responses suggest that…

  11. Visualizing Without Vision at the Microscale: Students With Visual Impairments Explore Cells With Touch

    Science.gov (United States)

    Jones, M. Gail; Minogue, James; Oppewal, Tom; Cook, Michelle P.; Broadwell, Bethany

    2006-12-01

    Science instruction is typically highly dependent on visual representations of scientific concepts that are communicated through textbooks, teacher presentations, and computer-based multimedia materials. Little is known about how students with visual impairments access and interpret these types of visually-dependent instructional materials. This study explored the efficacy of new haptic (simulated tactile feedback and kinesthetics) instructional technology for teaching cell morphology and function to middle and high school students with visual impairments. The study examined students' prior experiences learning about the cell and cell functions in classroom instruction, as well as how haptic feedback technology impacted students' awareness of the 3-D nature of an animal cell, the morphology and function of cell organelles, and students' interest in the haptic technology as an instructional tool. Twenty-one students with visual impairment participated in the study. Students explored a tactile model of the cell with a haptic point probe that allowed them to feel the cell and its organelles. Results showed that students made significant gains in their ability to identify cell organelles and found the technology to be highly interesting as an instructional tool. The need for additional adaptive technology for students with visual impairments is discussed.

  12. Magnifying the Scale of Visual Biofeedback Improves Posture.

    Science.gov (United States)

    Jehu, Deborah A; Thibault, Jérémie; Lajoie, Yves

    2016-06-01

    Biofeedback has been shown to minimize body sway during quiet standing. However, limited research has reported the optimal sensitivity parameters of visual biofeedback related to the center of pressure (COP) sway. Accordingly, 19 young adults (6 males; 13 females; aged 21.3 ± 2.5) stood with feet together and performed three visual biofeedback intensities [unmodified biofeedback (UMBF), BF magnified by 5 (BF5), BF magnified by 10 (BF10)], along with control trials with no biofeedback (NBF). The participants were instructed to stand as still as possible while minimizing the movements of the visual target. The findings revealed that UMBF produced significantly greater COP displacement in both the anterior-posterior (AP) and medial-lateral directions, as well as greater standard deviation of the COP in the AP direction (p postural sway. However, there were no significant differences on any of the COP measures between BF5 and BF10. This research provides insight with respect to the proper scale on which biofeedback should be given in order to improve postural control (i.e., BF5 or BF10). PMID:26678916

  13. From grid cells and visual place cells to multimodal place cell: a new robotic architecture.

    Science.gov (United States)

    Jauffret, Adrien; Cuperlier, Nicolas; Gaussier, Philippe

    2015-01-01

    In the present study, a new architecture for the generation of grid cells (GC) was implemented on a real robot. In order to test this model a simple place cell (PC) model merging visual PC activity and GC was developed. GC were first built from a simple "several to one" projection (similar to a modulo operation) performed on a neural field coding for path integration (PI). Robotics experiments raised several practical and theoretical issues. To limit the important angular drift of PI, head direction information was introduced in addition to the robot proprioceptive signal coming from the wheel rotation. Next, a simple associative learning between visual place cells and the neural field coding for the PI has been used to recalibrate the PI and to limit its drift. Finally, the parameters controlling the shape of the PC built from the GC have been studied. Increasing the number of GC obviously improves the shape of the resulting place field. Yet, other parameters such as the discretization factor of PI or the lateral interactions between GC can have an important impact on the place field quality and avoid the need of a very large number of GC. In conclusion, our results show our GC model based on the compression of PI is congruent with neurobiological studies made on rodent. GC firing patterns can be the result of a modulo transformation of PI information. We argue that such a transformation may be a general property of the connectivity from the cortex to the entorhinal cortex. Our model predicts that the effect of similar transformations on other kinds of sensory information (visual, tactile, auditory, etc…) in the entorhinal cortex should be observed. Consequently, a given EC cell should react to non-contiguous input configurations in non-spatial conditions according to the projection from its different inputs. PMID:25904862

  14. Improving Attack Graph Visualization through Data Reduction and Attack Grouping

    Energy Technology Data Exchange (ETDEWEB)

    John Homer; Ashok Varikuti; Xinming Ou; Miles A. McQueen

    2008-09-01

    Various tools exist to analyze enterprise network systems and to produce attack graphs detailing how attackers might penetrate into the system. These attack graphs, however, are often complex and difficult to comprehend fully, and a human user may find it problematic to reach appropriate configuration decisions. This paper presents methodologies that can 1) automatically identify portions of an attack graph that do not help a user to understand the core security problems and so can be trimmed, and 2) automatically group similar attack steps as virtual nodes in a model of the network topology, to immediately increase the understandability of the data. We believe both methods are important steps toward improving visualization of attack graphs to make them more useful in configuration management for large enterprise networks. We implemented our methods using one of the existing attack-graph toolkits. Initial experimentation shows that the proposed approaches can 1) significantly reduce the complexity of attack graphs by trimming a large portion of the graph that is not needed for a user to understand the security problem, and 2) significantly increase the accessibility and understandability of the data presented in the attack graph by clearly showing, within a generated visualization of the network topology, the number and type of potential attacks to which each host is exposed.

  15. Visualization of RNA-Quadruplexes in Live Cells.

    Science.gov (United States)

    Laguerre, Aurélien; Hukezalie, Kyle; Winckler, Pascale; Katranji, Fares; Chanteloup, Gaëtan; Pirrotta, Marc; Perrier-Cornet, Jean-Marie; Wong, Judy M Y; Monchaud, David

    2015-07-01

    Visualization of DNA and RNA quadruplex formation in human cells was demonstrated recently with different quadruplex-specific antibodies. Despite the significant interest in these immunodetection approaches, dynamic detection of quadruplex in live cells remains elusive. Here, we report on NaphthoTASQ (N-TASQ), a next-generation quadruplex ligand that acts as a multiphoton turn-on fluorescent probe. Single-step incubation of human and mouse cells with N-TASQ enables the direct detection of RNA-quadruplexes in untreated cells (no fixation, permeabilization or mounting steps), thus offering a unique, unbiased visualization of quadruplexes in live cells. PMID:26056849

  16. Improving the User Experience of Finding and Visualizing Oceanographic Data

    Science.gov (United States)

    Rauch, S.; Allison, M. D.; Groman, R. C.; Chandler, C. L.; Galvarino, C.; Gegg, S. R.; Kinkade, D.; Shepherd, A.; Wiebe, P. H.; Glover, D. M.

    2013-12-01

    Searching for and locating data of interest can be a challenge to researchers as increasing volumes of data are made available online through various data centers, repositories, and archives. The Biological and Chemical Oceanography Data Management Office (BCO-DMO) is keenly aware of this challenge and, as a result, has implemented features and technologies aimed at improving data discovery and enhancing the user experience. BCO-DMO was created in 2006 to manage and publish data from research projects funded by the Division of Ocean Sciences (OCE) Biological and Chemical Oceanography Sections and the Division of Polar Programs (PLR) Antarctic Sciences Organisms and Ecosystems Program (ANT) of the US National Science Foundation (NSF). The BCO-DMO text-based and geospatial-based data access systems provide users with tools to search, filter, and visualize data in order to efficiently find data of interest. The geospatial interface, developed using a suite of open-source software (including MapServer [1], OpenLayers [2], ExtJS [3], and MySQL [4]), allows users to search and filter/subset metadata based on program, project, or deployment, or by using a simple word search. The map responds based on user selections, presents options that allow the user to choose specific data parameters (e.g., a species or an individual drifter), and presents further options for visualizing those data on the map or in "quick-view" plots. The data managed and made available by BCO-DMO are very heterogeneous in nature, from in-situ biogeochemical, ecological, and physical data, to controlled laboratory experiments. Due to the heterogeneity of the data types, a 'one size fits all' approach to visualization cannot be applied. Datasets are visualized in a way that will best allow users to assess fitness for purpose. An advanced geospatial interface, which contains a semantically-enabled faceted search [5], is also available. These search facets are highly interactive and responsive, allowing

  17. Monterey Learning Systems: Improving Academic Achievement of Visually Impaired Learners

    Science.gov (United States)

    Daugherty, Kathryn M.

    1977-01-01

    Tested was the premise that the academic competencies of visually impaired learners could be enhanced by training procedures that combine auditory and visual skills in a project using the Monterey Learning Systems Reading and Mathematics Programs with 29 visually impaired print readers. (Author/MH)

  18. Atypical visual loss in giant cell arteritis

    DEFF Research Database (Denmark)

    Thystrup, Jan Deichmann; Knudsen, G M; Mogensen, A M;

    1994-01-01

    terminal stage of his disease due to bilateral occipital cortex infarctions, verified by CT-scan. Autopsy revealed involvement of several intracranial arteries. In case No. 2 there was severe unilateral visual loss and cotton-wool exudates in both eyes. Central vision recovered after corticosteroid therapy...

  19. Improved Visualization of Lung Metastases at Single Cell Resolution in Mice by Combined In-situ Perfusion of Lung Tissue and X-Gal Staining of lacZ-Tagged Tumor Cells

    OpenAIRE

    Matthias J E Arlt; Born, Walter; Fuchs, Bruno

    2012-01-01

    Metastasis is the main cause of death in the majority of cancer types and consequently a main focus in cancer research. However, the detection of micrometastases by radiologic imaging and the success in their therapeutic eradication remain limited. While animal models have proven to be invaluable tools for cancer research1, the monitoring/visualization of micrometastases remains a challenge and inaccurate evaluation of metastatic spread in preclinical studies potentially leads to disappointin...

  20. Improving teacher awareness through activity, badge and content visualizations

    OpenAIRE

    Charleer, Sven; Santos Odriozola, Jose Luis; Klerkx, Joris; Duval, Erik

    2014-01-01

    This paper introduces LARAe (Learning Analytics Reflection & Awareness environment), a teacher-oriented dashboard that visualizes learning traces from students, badges and course content. We also present an evaluation of the dashboard in a course on Human-Computer Interaction. The LARAe teacher dashboard provides a detailed overview of group and individual activities, achievements and course outcomes. To help visualize the abundance of traces, badges are used to abstract essential aspects of ...

  1. Visual cells remember earlier applied target: plasticity of orientation selectivity.

    Directory of Open Access Journals (Sweden)

    Narcis Ghisovan

    Full Text Available BACKGROUND: A canonical proposition states that, in mature brain, neurons responsive to sensory stimuli are tuned to specific properties installed shortly after birth. It is amply demonstrated that that neurons in adult visual cortex of cats are orientation-selective that is they respond with the highest firing rates to preferred oriented stimuli. METHODOLOGY/PRINCIPAL FINDINGS: In anesthetized cats, prepared in a conventional fashion for single cell recordings, the present investigation shows that presenting a stimulus uninterruptedly at a non-preferred orientation for twelve minutes induces changes in orientation preference. Across all conditions orientation tuning curves were investigated using a trial by trial method. Contrary to what has been previously reported with shorter adaptation duration, twelve minutes of adaptation induces mostly attractive shifts, i.e. toward the adapter. After a recovery period allowing neurons to restore their original orientation tuning curves, we carried out a second adaptation which produced three major results: (1 more frequent attractive shifts, (2 an increase of their magnitude, and (3 an additional enhancement of responses at the new or acquired preferred orientation. Additionally, we also show that the direction of shifts depends on the duration of the adaptation: shorter adaptation in most cases produces repulsive shifts, whereas adaptation exceeding nine minutes results in attractive shifts, in the same unit. Consequently, shifts in preferred orientation depend on the duration of adaptation. CONCLUSION/SIGNIFICANCE: The supplementary response improvements indicate that neurons in area 17 keep a memory trace of the previous stimulus properties, thereby upgrading cellular performance. It also highlights the dynamic nature of basic neuronal properties in adult cortex since repeated adaptations modified both the orientation tuning selectivity and the response strength to the preferred orientation. These

  2. IMPROVING THREE-DIMENSIONAL OBJECT VISUALIZATION USER INTERFACE WITH AUGMENTED REALITY TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Kravtsov �. M.

    2014-06-01

    Full Text Available The article describes hardware and software specific issues of implementing augmented reality for improving user interface of visualization of a virtual object. It also defines possible future improvements of the subject

  3. Audio-visual stimulation improves oculomotor patterns in patients with hemianopia.

    Science.gov (United States)

    Passamonti, Claudia; Bertini, Caterina; Làdavas, Elisabetta

    2009-01-01

    Patients with visual field disorders often exhibit impairments in visual exploration and a typical defective oculomotor scanning behaviour. Recent evidence [Bolognini, N., Rasi, F., Coccia, M., & Làdavas, E. (2005b). Visual search improvement in hemianopic patients after audio-visual stimulation. Brain, 128, 2830-2842] suggests that systematic audio-visual stimulation of the blind hemifield can improve accuracy and search times in visual exploration, probably due to the stimulation of Superior Colliculus (SC), an important multisensory structure involved in both the initiation and execution of saccades. The aim of the present study is to verify this hypothesis by studying the effects of multisensory training on oculomotor scanning behaviour. Oculomotor responses during a visual search task and a reading task were studied before and after visual (control) or audio-visual (experimental) training, in a group of 12 patients with chronic visual field defects and 12 controls subjects. Eye movements were recorded using an infra-red technique which measured a range of spatial and temporal variables. Prior to treatment, patients' performance was significantly different from that of controls in relation to fixations and saccade parameters; after Audio-Visual Training, all patients reported an improvement in ocular exploration characterized by fewer fixations and refixations, quicker and larger saccades, and reduced scanpath length. Overall, these improvements led to a reduction of total exploration time. Similarly, reading parameters were significantly affected by the training, with respect to specific impairments observed in both left- and right-hemianopia readers. Our findings provide evidence that Audio-Visual Training, by stimulating the SC, may induce a more organized pattern of visual exploration due to an implementation of efficient oculomotor strategies. Interestingly, the improvement was found to be stable at a 1 year follow-up control session, indicating a long

  4. Phase sensitivity of complex cells in primary visual cortex.

    Science.gov (United States)

    Hietanen, M A; Cloherty, S L; van Kleef, J P; Wang, C; Dreher, B; Ibbotson, M R

    2013-05-01

    Neurons in the primary visual cortex are often classified as either simple or complex based on the linearity (or otherwise) of their response to spatial luminance contrast. In practice, classification is typically based on Fourier analysis of a cell's response to an optimal drifting sine-wave grating. Simple cells are generally considered to be linear and produce responses modulated at the fundamental frequency of the stimulus grating. In contrast, complex cells exhibit significant nonlinearities that reduce the response at the fundamental frequency. Cells can therefore be easily and objectively classified based on the relative modulation of their responses - the ratio of the phase-sensitive response at the fundamental frequency of the stimulus (F₁) to the phase-invariant sustained response (F₀). Cells are classified as simple if F₁/F₀>1 and complex if F₁/F₀<1. This classification is broadly consistent with criteria based on the spatial organisation of cells' receptive fields and is accordingly presumed to reflect disparate functional roles of simple and complex cells in coding visual information. However, Fourier analysis of spiking responses is sensitive to the number of spikes available - F₁/F₀ increases as the number of spikes is reduced, even for phase-invariant complex cells. Moreover, many complex cells encountered in the laboratory exhibit some phase sensitivity, evident as modulation of their responses at the fundamental frequency. There currently exists no objective quantitative means of assessing the significance or otherwise of these modulations. Here we derive a statistical basis for objectively assessing whether the modulation of neuronal responses is reliable, thereby adding a level of statistical certainty to measures of phase sensitivity. We apply our statistical analysis to neuronal responses to moving sine-wave gratings recorded from 367 cells in cat primary visual cortex. We find that approximately 60% of complex cells exhibit

  5. Glial cell development and function in the Drosophila visual system

    OpenAIRE

    CHOTARD, CAROLE; Salecker, Iris

    2007-01-01

    In the developing nervous system, building a functional neuronal network relies on coordinating the formation, specification and survival to diverse neuronal and glial cell subtypes. The establishment of neuronal connections further depends on sequential neuron–neuron and neuron–glia interactions that regulate cell-migration patterns and axon guidance. The visual system of Drosophila has a highly regular, retinotopic organization into reiterated interconnected synaptic circuits. It is therefo...

  6. Improvement in the quality factors for photonic crystal nanocavities via visualization of the leaky components.

    Science.gov (United States)

    Nakamura, Tatsuya; Takahashi, Yasushi; Tanaka, Yoshinori; Asano, Takashi; Noda, Susumu

    2016-05-01

    A method that simply improves the quality (Q) factors of two-dimensional photonic crystal nanocavities using a three-dimensional finite-difference time domain calculation is described. The leaky area for a high-Q nanocavity mode is visualized in a real cavity structure by extracting the leaky components within a light cone in momentum space and by transferring them back into real space using an inverse Fourier transformation. The Q factor is remarkably improved by appropriately shifting the positions of air holes at the leaky area. We design three-missing-air-hole and zero-cell-defect nanocavities with Q factors of 5,000,000 and 1,700,000, respectively, for demonstration. PMID:27137567

  7. Improving user-friendliness by using visually supported speech recognition

    NARCIS (Netherlands)

    Waals, J.A.J.S.; Kooi, F.L.; Kriekaard, J.J.

    2002-01-01

    While speech recognition in principle may be one of the most natural interfaces, in practice it is not due to the lack of user-friendliness. Words are regularly interpreted wrong, and subjects tend to articulate in an exaggerated manner. We explored the potential of visually supported error correcti

  8. Visualization and targeted disruption of protein interactions in living cells

    OpenAIRE

    Herce, Henry D.; Deng, Wen; Helma, Jonas; Leonhardt, Heinrich; Cardoso, M. Cristina

    2013-01-01

    Protein–protein interactions are the basis of all processes in living cells, but most studies of these interactions rely on biochemical in vitro assays. Here we present a simple and versatile fluorescent-three-hybrid (F3H) strategy to visualize and target protein–protein interactions. A high-affinity nanobody anchors a GFP-fusion protein of interest at a defined cellular structure and the enrichment of red-labelled interacting proteins is measured at these sites. With this approach, we visual...

  9. Intuitive Source Code Visualization Tools for Improving Student Comprehension: BRICS

    CERN Document Server

    Pearson, Christopher; Coady, Yvonne

    2008-01-01

    Even relatively simple code analysis can be a daunting task for many first year students. Perceived complexity, coupled with foreign and harsh syntax, often outstrips the ability for students to take in what they are seeing in terms of their verbal memory. That is, first year students often lack the experience to encode critical building blocks in source code, and their interrelationships, into their own words. We believe this argues for the need for IDEs to provide additional support for representations that would appeal directly to visual memory. In this paper, we examine this need for intuitive source code visualization tools that are easily accessible to novice programmers, discuss the requirements for such a tool, and suggest a novel idea that takes advantage of human peripheral vision to achieve stronger overall code structure awareness.

  10. Sound can improve visual search in developmental dyslexia

    OpenAIRE

    de Boer-Schellekens, L.; Vroomen, J.

    2011-01-01

    We examined whether developmental dyslexic adults suffer from sluggish attentional shifting (SAS; Hari and Renvall in Trends Cogn Sci 5:525–532, 2001) by measuring their shifting of attention in a visual search task with dynamic cluttered displays (Van der Burg et al. in J Exp Psychol Human 34:1053–1065, 2008). Dyslexics were generally slower than normal readers in searching a horizontal or vertical target among oblique distracters. However, the addition of a click sound presented in synchron...

  11. Visual Tools and Narratives: New Ways to Improve Financial Literacy

    OpenAIRE

    Annamaria Lusardi; Anya Savikhin Samek; Arie Kapteyn; Lewis Glinert; Angela Hung; Aileen Heinberg

    2014-01-01

    We developed and experimentally evaluated four novel educational programs delivered online: an informational brochure, a visual interactive tool, a written narrative, and a video narrative. The programs were designed to inform people about risk diversification, an essential concept for financial decision- making. The effectiveness of these programs was evaluated using the RAND American Life Panel. Participants were exposed to one of the programs, and then asked to answer questions measuring f...

  12. Improving Empathy and Communication Skills of Visually Impaired Early Adolescents through a Psycho-Education Program

    Science.gov (United States)

    Yildiz, Mehmet Ali; Duy, Baki

    2013-01-01

    The purpose of this study was to investigate the effectiveness of an interpersonal communication skills psycho-education program to improve empathy and communication skills of visually impaired adolescents. Participants of the study were sixteen early adolescents schooling in an elementary school for visually impaired youth in Diyarbakir. The…

  13. Visual Working Memory in Deaf Children with Diverse Communication Modes: Improvement by Differential Outcomes

    Science.gov (United States)

    Lopez-Crespo, Ginesa; Daza, Maria Teresa; Mendez-Lopez, Magdalena

    2012-01-01

    Although visual functions have been proposed to be enhanced in deaf individuals, empirical studies have not yet established clear evidence on this issue. The present study aimed to determine whether deaf children with diverse communication modes had superior visual memory and whether their performance was improved by the use of differential…

  14. Visual Design Guidelines for Improving Learning from Dynamic and Interactive Digital Text

    Science.gov (United States)

    Jin, Sung-Hee

    2013-01-01

    Despite the dynamic and interactive features of digital text, the visual design guidelines for digital text are similar to those for printed text. The purpose of this study was to develop visual design guidelines for improving learning from dynamic and interactive digital text and to validate them by controlled testing. Two structure design…

  15. Intensive video gaming improves encoding speed to visual short-term memory in young male adults.

    Science.gov (United States)

    Wilms, Inge L; Petersen, Anders; Vangkilde, Signe

    2013-01-01

    The purpose of this study was to measure the effect of action video gaming on central elements of visual attention using Bundesen's (1990) Theory of Visual Attention. To examine the cognitive impact of action video gaming, we tested basic functions of visual attention in 42 young male adults. Participants were divided into three groups depending on the amount of time spent playing action video games: non-players (15h/month, N=20). All participants were tested in three tasks which tap central functions of visual attention and short-term memory: a test based on the Theory of Visual Attention (TVA), an enumeration test and finally the Attentional Network Test (ANT). The results show that action video gaming does not seem to impact the capacity of visual short-term memory. However, playing action video games does seem to improve the encoding speed of visual information into visual short-term memory and the improvement does seem to depend on the time devoted to gaming. This suggests that intense action video gaming improves basic attentional functioning and that this improvement generalizes into other activities. The implications of these findings for cognitive rehabilitation training are discussed. PMID:23261420

  16. Developmental changes in cytosolic coupling between epidermis cells as visualized by photoactivation of fluorescein

    DEFF Research Database (Denmark)

    Liu, Xiangdong; Martens, Helle; Schulz, Alexander

    Developmental changes in cytosolic coupling between epidermis cells as visualized by photoactivation of fluorescein.......Developmental changes in cytosolic coupling between epidermis cells as visualized by photoactivation of fluorescein....

  17. Improved visualization of delayed perfusion in lung MRI

    International Nuclear Information System (INIS)

    Introduction: The investigation of pulmonary perfusion by three-dimensional (3D) dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was proposed recently. Subtraction images are generated for clinical evaluation, but temporal information is lost and perfusion defects might therefore be masked in this process. The aim of this study is to demonstrate a simple analysis strategy and classification for 3D-DCE-MRI perfusion datasets in the lung without omitting the temporal information. Materials and methods: Pulmonary perfusion measurements were performed in patients with different lung diseases using a 1.5 T MR-scanner with a time-resolved 3D-GRE pulse sequence. 25 3D-volumes were acquired after iv-injection of 0.1 mmol/kg KG Gadolinium-DTPA. Three parameters were determined for each pixel: (1) peak enhancement Sn,max normalized to the arterial input function to detect regions of reduced perfusion; (2) time between arterial peak enhancement in the large pulmonary artery and tissue peak enhancement τ to visualize regions with delayed bolus onset; and (3) ratio R = Sn,max/τ was calculated to visualize impaired perfusion, irrespectively of whether related to reduced or delayed perfusion. Results: A manual selection of peak perfusion images is not required. Five different types of perfusion can be found: (1) normal perfusion; (2) delayed non-reduced perfusion; (3) reduced non-delayed perfusion; (4) reduced and delayed perfusion; and (5) no perfusion. Types II and IV could not be seen in subtraction images since the temporal information is necessary for this purpose. Conclusions: The analysis strategy in this study allows for a simple and observer-independent visualization and classification of impaired perfusion in dynamic contrast-enhanced pulmonary perfusion MRI by using the temporal information of the datasets.

  18. Action video game playing is associated with improved visual sensitivity, but not alterations in visual sensory memory.

    Science.gov (United States)

    Appelbaum, L Gregory; Cain, Matthew S; Darling, Elise F; Mitroff, Stephen R

    2013-08-01

    Action video game playing has been experimentally linked to a number of perceptual and cognitive improvements. These benefits are captured through a wide range of psychometric tasks and have led to the proposition that action video game experience may promote the ability to extract statistical evidence from sensory stimuli. Such an advantage could arise from a number of possible mechanisms: improvements in visual sensitivity, enhancements in the capacity or duration for which information is retained in visual memory, or higher-level strategic use of information for decision making. The present study measured the capacity and time course of visual sensory memory using a partial report performance task as a means to distinguish between these three possible mechanisms. Sensitivity measures and parameter estimates that describe sensory memory capacity and the rate of memory decay were compared between individuals who reported high evels and low levels of action video game experience. Our results revealed a uniform increase in partial report accuracy at all stimulus-to-cue delays for action video game players but no difference in the rate or time course of the memory decay. The present findings suggest that action video game playing may be related to enhancements in the initial sensitivity to visual stimuli, but not to a greater retention of information in iconic memory buffers. PMID:23709062

  19. Effect of Contrast on Visual Spatial Summation in Different Cell Categories in Cat Primary Visual Cortex.

    Directory of Open Access Journals (Sweden)

    Ke Chen

    Full Text Available Multiple cell classes have been found in the primary visual cortex, but the relationship between cell types and spatial summation has seldom been studied. Parvalbumin-expressing inhibitory interneurons can be distinguished from pyramidal neurons based on their briefer action potential durations. In this study, we classified V1 cells into fast-spiking units (FSUs and regular-spiking units (RSUs and then examined spatial summation at high and low contrast. Our results revealed that the excitatory classical receptive field and the suppressive non-classical receptive field expanded at low contrast for both FSUs and RSUs, but the expansion was more marked for the RSUs than for the FSUs. For most V1 neurons, surround suppression varied as the contrast changed from high to low. However, FSUs exhibited no significant difference in the strength of suppression between high and low contrast, although the overall suppression decreased significantly at low contrast for the RSUs. Our results suggest that the modulation of spatial summation by stimulus contrast differs across populations of neurons in the cat primary visual cortex.

  20. Brain polarization of parietal cortex augments training-induced improvement of visual exploratory and attentional skills.

    Science.gov (United States)

    Bolognini, Nadia; Fregni, Felipe; Casati, Carlotta; Olgiati, Elena; Vallar, Giuseppe

    2010-08-19

    Recent evidence suggests that behavioural gains induced by behavioural training are maximized when combined with techniques of cortical neuromodulation, such as transcranial Direct Current Stimulation (tDCS). Here we address the validity of this appealing approach by investigating the effect of coupling a multisensory visual field exploration training with tDCS of the posterior parietal cortex (PPC). The multisensory visual field exploration training consisted in the practice of visual search through the systematic audio-visual stimulation of the visual field. Neurologically unimpaired participants performed a bimodal exploration training for 30 min, while simultaneously receiving anodal-excitatory PPC tDCS or sham tDCS. In two different experiments, the left and the right hemisphere were stimulated. Outcome measures included visual exploration speed at different time intervals during the training, and the post-training effects on tests assessing visual scanning and visuo-spatial orienting. Results show that PPC tDCS applied to the right, but not to the left, hemisphere increases the training-induced behavioural improvement of visual exploration, as compared to sham tDCS. In addition, right PPC tDCS brings about an improvement of covert visual orienting, in a task different from the visual search practice. In an additional experiment, we confirm that right parietal tDCS by itself, even without the associated training, can lead to enhancement of visual search. Overall, anodal PPC tDCS is a promising technique to enhance visuo-spatial abilities, when combined to a visual field exploration training task. PMID:20599813

  1. Plasma Etching Improves Solar Cells

    Science.gov (United States)

    Bunyan, S. M.

    1982-01-01

    Etching front surfaces of screen-printed silicon photovoltaic cells with sulfur hexafluoride plasma found to increase cell performance while maintaining integrity of screen-printed silver contacts. Replacement of evaporated-metal contacts with screen-printed metal contacts proposed as one way to reduce cost of solar cells for terrestrial applications.

  2. An improved method to visualize eosinophils in eosinophilic esophagitis.

    Science.gov (United States)

    Rubio, C A; Glaessgen, A

    2006-01-01

    We previously found in Giemsa-stained colorectal sections from IBD patients that eosinophilic granulocytes turned fluorescent when excited with indirect fluorescent light, while other inflammatory cells were non-fluorescent. We now studied with that method, the frequency of eosinophilic granulocytes in sections from patients with eosinophilic esophagitis (EE). Cell counting was done in consecutive sections stained with Giemsa stain using indirect fluorescence light (G-IFL setting) and with hematoxylin-eosin using transmitted light (HE-TL setting) in 5 cases of EE and in 10 consecutive cases of reflux esophagitis (RE) grade 2. In EE 45.0 eosinophils/case (range 39-51) were recorded with the G-IFL setting but only 33.4 eosinophils/case (range 28-39) with the HE-TL setting (p cell counting is not necessary. PMID:17091778

  3. Visualization and targeted disruption of protein interactions in living cells.

    Science.gov (United States)

    Herce, Henry D; Deng, Wen; Helma, Jonas; Leonhardt, Heinrich; Cardoso, M Cristina

    2013-01-01

    Protein-protein interactions are the basis of all processes in living cells, but most studies of these interactions rely on biochemical in vitro assays. Here we present a simple and versatile fluorescent-three-hybrid (F3H) strategy to visualize and target protein-protein interactions. A high-affinity nanobody anchors a GFP-fusion protein of interest at a defined cellular structure and the enrichment of red-labelled interacting proteins is measured at these sites. With this approach, we visualize the p53-HDM2 interaction in living cells and directly monitor the disruption of this interaction by Nutlin 3, a drug developed to boost p53 activity in cancer therapy. We further use this approach to develop a cell-permeable vector that releases a highly specific peptide disrupting the p53 and HDM2 interaction. The availability of multiple anchor sites and the simple optical readout of this nanobody-based capture assay enable systematic and versatile analyses of protein-protein interactions in practically any cell type and species. PMID:24154492

  4. Frequency-Wavenumber Domain Filtering for Improved Damage Visualization

    International Nuclear Information System (INIS)

    This paper presents a technique for the analysis of full wavefield data in the wavenumber/frequency domain as an effective tool for damage detection, visualization and characterization. Full wavefield data contain a wealth of information regarding the space and time variation of propagating waves in damaged structural components. Such information can be used to evaluate the response spectrum in the frequency/wavenumber domain, which effectively separates incident waves from reflections caused by discontinuities encountered along the wave paths. This allows removing the injected wave from the overall response through simple filtering strategies, thus highlighting the presence of reflections associated to damage. The concept is first illustrated on analytical and numerically simulated data, and then tested on experimental results. In the experiments, full wavefield measurements are conveniently obtained using a Scanning Laser Doppler Vibrometer, which allows the detection of displacements and/or velocities over a user-defined grid, and it is able to provide the required spatial and time information in a timely manner. Tests performed on a simple aluminum plate with artificially seeded slits simulating longitudinal cracks, and on a disbonded tongue and groove joint show the effectiveness of the technique and its potential for application to the inspection of a variety of structural components

  5. Communicative interactions improve visual detection of biological motion.

    Directory of Open Access Journals (Sweden)

    Valeria Manera

    Full Text Available BACKGROUND: In the context of interacting activities requiring close-body contact such as fighting or dancing, the actions of one agent can be used to predict the actions of the second agent. In the present study, we investigated whether interpersonal predictive coding extends to interactive activities--such as communicative interactions--in which no physical contingency is implied between the movements of the interacting individuals. METHODOLOGY/PRINCIPAL FINDINGS: Participants observed point-light displays of two agents (A and B performing separate actions. In the communicative condition, the action performed by agent B responded to a communicative gesture performed by agent A. In the individual condition, agent A's communicative action was substituted with a non-communicative action. Using a simultaneous masking detection task, we demonstrate that observing the communicative gesture performed by agent A enhanced visual discrimination of agent B. CONCLUSIONS/SIGNIFICANCE: Our finding complements and extends previous evidence for interpersonal predictive coding, suggesting that the communicative gestures of one agent can serve as a predictor for the expected actions of the respondent, even if no physical contact between agents is implied.

  6. Visualization of Carbon Nanoparticles Within Cells and Implications for Toxicity

    Science.gov (United States)

    Porter, Alexandra; Gass, Mhairi

    Carbon nanostructures (CNS), such as C60, single-walled nanotubes (SWNTs) exhibit extraordinary properties and are one of the most commercially relevant class of NS. CNS have already found uses in high-performance sports equipment (nanotubes) and face cream (C60), whilst potential applications include optical and electronic materials and superconductors. Following the huge growth in these nanotechnology-related industries, significant concerns have arisen about their potential toxicity and impact on the environment. A lack in understanding of the interaction of such small structures with cellular material has resulted in concerns over their impact on human health. The potential toxicity of CNS and safety to human health requires an understanding of their interaction with cells and this in turn relies on the measurement of the pathways by which they enter the cell, their spatial distribution within and whether the CNS are transformed by the action of the cell; visualization of intracellular CNS is therefore imperative. However visualizing unlabelled CNS within cells is demanding because it is difficult to distinguish CNS from carbon-rich organelles given their similarity in composition and dimensions. In particular, the challenge lies in translating analytical imaging tools developed for inorganic systems to organic systems. This chapter describes how the state-of-the-art transmission electron microscopy (TEM) techniques, such as low-loss energy-filtered TEM (EFTEM) can be employed to differentiate between unlabelled C60, SWNTs and the cell. Further, we demonstrate how these techniques can be used to trace the uptake of CNS into the cell and to assess their localized effects on cell structure.

  7. Visual Servoed Three-Dimensional Cell Rotation System.

    Science.gov (United States)

    Wang, Zenan; Latt, Win Tun; Tan, Steven Yih Min; Ang, Wei Tech

    2015-10-01

    Three-dimensional (3-D) positioning and orientation of embryos/oocytes is necessary to facilitate micromanipulation tasks such as cell injection and cellular structural biopsy commonly performed under a microscope. Conventional cell orientation is performed manually by using a vacuum equipped micropipette to aspirate and release the cell, which is a trial-and-error approach. The conventional method relies heavily on the skill of the operator; it also suffers from low precision, low success rate and low controllability. These drawbacks illustrate the need for a systematic 3-D cell rotational system to automate the cell orientation process. In this paper, we present a noninvasive single cell rotation system that can automatically orientate a zebrafish embryo to a desired position when both the cytoplasm and the yolk are in the focal plane. A three-point-contact model for cell rotation that involves a custom-designed rotational stage is introduced to provide precise rotational position control. A vision recognition algorithm is also proposed to enable the visual servoing function of the system. Experimental results show that the proposed system can achieve high success rates of 92.5% (x-axis rotation with 40 trails) and 97.5% (about the z-axis with 80 trails). The system can also successfully complete 3-D cell orientation at an average speed of 31 s/cell with a high in-plane rotation accuracy of 0.3 (°) . As a high precise, high controllable and deterministic cell manipulating system, it provides a starting point for automated cell manipulation for intracytoplasmic sperm injection and embryo biopsy for preimplantation genetic diagnosis. PMID:25993702

  8. Using the Visual Phonics System to Improve Speech Skills: A Preliminary Study.

    Science.gov (United States)

    Wilson-Favors, Vanessa

    1987-01-01

    The "Visual Phonics" system, which uses 43 hand cues and corresponding written symbols to help deaf students improve their speech and reading skills, was evaluated with six deaf upper elementary grade students in a speech therapy program. Pre- and posttesting indicated substantially improved articulation both with and without hand cues. (DB)

  9. Improved microcalcification visualization using dual-energy digital mammography

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Chia-Jung [Dept. of Medical Imaging and Radiological Sciences, Chung Shan Medical Univ., Taichung (Taiwan, Province of China); Chen, Ran-Chou [Dept. of Biomedical Imaging and Radiological Sciences, National Yang-Ming Univ., Taipei (Taiwan, Province of China); Dept. of Radiology, Taipei City Hospital, Taipei (Taiwan, Province of China); Peng, Hui-Ling [Dept. of Diagnostic Radiology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei (Taiwan, Province of China); Hsu, Wen-Lin [School of Medicine, Tzu-Chi Univ., Hualien (Taiwan, Province of China); Dept. of Radiation Oncology, Buddhist Tzu-Chi General Hospital, Hualien (Taiwan, Province of China); Lee, Jason JS [Dept. of Biomedical Imaging and Radiological Sciences, National Yang-Ming Univ., Taipei (Taiwan, Province of China)], e-mail: jslee@ym.edu.tw, hwl@tzuchi.com.tw

    2013-07-15

    Background: Dual-energy digital mammography (DEDM), involving a combination of high-energy (HE) and low-energy (LE) images, has been investigated as offering a potential improvement in microcalcification detection obscured by overlapping tissue structures. Purpose: To explore the possibility to improve detection of microcalcifications using the DEDM technique. Material and Methods: Three DEDM protocols were performed by adjusting the effective tube current time product (mAs) of LE image at the same (100%), one half (50%), and one-quarter (25%) of that used in HE image acquisition, named DEDM{sub 100%}, DEDM{sub 50%}, and DEDM{sub 25%}, respectively. A single-energy digital mammography (SEDM) method was also used as a control. A total of 525 regions of interest (ROIs) were used to compare the performance of the DEDM to that of SEDM using free-response receiver-operating characteristic (FROC) and areas under the FROC curve (A{sub z}). Results: All DEDM protocols ranked significantly higher than the SEDM method (P < 0.001). The true-positive fraction was 0.90 for an average of 0.017 - 0.042 false-positive per image using the DEDM{sub 100%}, 0.017 - 0.114 using the DEDM{sub 50%}, 0.021 - 0.148 using the DEDM{sub 25%}, and 0.134 - 0.422 using the SEDM. The estimated A{sub z} values were 0.915 - 0.940, 0.867 - 0.935, 0.824 - 0.930, and 0.567 - 0.673, respectively. Conclusion: The DEDM{sub 50%} protocol provided a trade-off benefit between accurate microcalcification detectability and radiation dose for any tissue density. Therefore, the DEDM{sub 50%} has the potential to minimize excess radiation dose without a negative impact on image quality which could improve earlier diagnosis of breast cancer.

  10. Polyacrylamide gel miniaturization improves protein visualization and autoradiographic detection

    International Nuclear Information System (INIS)

    Polyacrylamide gels shrink to one-quarter of their original area when soaked in a 50% (w/v) solution of polyethylene glycol. Gel miniaturization improves the contrast of protein bands, with four valuable consequences. (i) A 5- to 10-fold increase in sensitivity for Coomassie blue is observed. (ii) Gels are more durable; i.e., they resist tearing when wet and they do not crack during drying under vacuum. (iii) Shrunken gels give sharper photographic images and provide better interlane protein band comparisons. (iv) Condensed protein bands lead to an increased sensitivity for detecting low-abundance, radioactively-labeled proteins by fluorography

  11. Direct Visualization of De novo Lipogenesis in Single Living Cells

    Science.gov (United States)

    Li, Junjie; Cheng, Ji-Xin

    2014-10-01

    Increased de novo lipogenesis is being increasingly recognized as a hallmark of cancer. Despite recent advances in fluorescence microscopy, autoradiography and mass spectrometry, direct observation of de novo lipogenesis in living systems remains to be challenging. Here, by coupling stimulated Raman scattering (SRS) microscopy with isotope labeled glucose, we were able to trace the dynamic metabolism of glucose in single living cells with high spatial-temporal resolution. As the first direct visualization, we observed that glucose was largely utilized for lipid synthesis in pancreatic cancer cells, which occurs at a much lower rate in immortalized normal pancreatic epithelial cells. By inhibition of glycolysis and fatty acid synthase (FAS), the key enzyme for fatty acid synthesis, we confirmed the deuterium labeled lipids in cancer cells were from de novo lipid synthesis. Interestingly, we also found that prostate cancer cells exhibit relatively lower level of de novo lipogenesis, but higher fatty acid uptake compared to pancreatic cancer cells. Together, our results demonstrate a valuable tool to study dynamic lipid metabolism in cancer and other disorders.

  12. Improved load-cell compensation

    Science.gov (United States)

    Egger, R. L.

    1977-01-01

    Improved bridge-compensation circuit saves considerable time in balancing bridge and wiring it for temperature compensation. Large bridge-balance compensation is made before temperature cycling and small adjustments are made with different type of wire.

  13. NMR structure improvement: A structural bioinformatics & visualization approach

    Science.gov (United States)

    Block, Jeremy N.

    The overall goal of this project is to enhance the physical accuracy of individual models in macromolecular NMR (Nuclear Magnetic Resonance) structures and the realism of variation within NMR ensembles of models, while improving agreement with the experimental data. A secondary overall goal is to combine synergistically the best aspects of NMR and crystallographic methodologies to better illuminate the underlying joint molecular reality. This is accomplished by using the powerful method of all-atom contact analysis (describing detailed sterics between atoms, including hydrogens); new graphical representations and interactive tools in 3D and virtual reality; and structural bioinformatics approaches to the expanded and enhanced data now available. The resulting better descriptions of macromolecular structure and its dynamic variation enhances the effectiveness of the many biomedical applications that depend on detailed molecular structure, such as mutational analysis, homology modeling, molecular simulations, protein design, and drug design.

  14. Improving texture optimization with application to visualizing meat products

    DEFF Research Database (Denmark)

    Clemmensen, Line Katrine Harder; Laursen, Lasse Farnung

    (such as color, translucency, reflective properties). One way of reintroducing this lost information back to the volume data is to synthesize an appropriate texture and apply this to the volume data. A recent method within the field of texture synthesis is called Texture Optimization presented by Kopf...... et al. in 2007. This method accepts a number of 2D input exemplars, from which it generates a solid texture volume. The volume is iteratively improved via an expectation maximization algorithm. The bottleneck of Texture Optimization occurs during a nearest neighbor search, between texture patches...... from the 2D input exemplars and the generated texture volume. We examine the current procedures for minimizing the bottleneck and present a novel approach which increases the speed of the synthesis algorithm while minimizing loss of quality. The nearest neighbor search is performed in a high...

  15. Visual appearance and CMT score of foremilk of individual quarters in relation to cell count of cows milked automatically.

    Science.gov (United States)

    Rasmussen, Morten D; Bjerring, Martin; Skjøth, Flemming

    2005-02-01

    The objectives of the study were: to evaluate the interaction between visual appearance and California mastitis test (CMT) score of the foremilk in relation to the cell count of the milk; to evaluate the consequences of sorting milk according to these criteria; and to explore whether visual appearance and CMT score of foremilk depended on the time interval between milkings. Measuring somatic cell count (SCC) in composite milk only and discarding milk above certain thresholds will not ensure that milk from all cows with visually abnormal foremilk is withheld from delivery. Low thresholds of SCC will reduce the frequency of cows with abnormal milk but increase the discarding of milk from cows with visually normal foremilk. CMT score of foremilk differentiated better between cows with high and low SCC in composite milk than visual inspection of foremilk. CMT scores of foremilk decreased with increasing interval between milkings within cow, whereas the visual appearance was independent of the interval. We propose that visual appearance of the foremilk should be kept as a criterion for sorting milk at time of milking. For test purposes, the use of visual appearance of foremilk for differentiation between normal and abnormal milk has to be done on multiple milkings. Additionally, CMT scoring of foremilk improves correct classification of normal and abnormal quarters and especially when including data from the previous milking. PMID:15747731

  16. Visualizing Improved Spin Coupling in Large Magnetic Molecules

    Science.gov (United States)

    Donner, Judith; Broschinski, Jan-Philipp; Feldscher, Bastian; Glaser, Thorsten; Khajetoorians, Alexander Ako; Wegner, Daniel

    In an attempt to combine a high spin ground state and a large magnetic anisotropy in one molecule, triplesalen-based complexes are promising building blocks for a new generation of single molecule magnets (SMMs). The spin coupling in these molecules is based on the spin polarization effect, which requires a delocalized aromatic π-system in the central carbon ring of the complex. Unfortunately, chemical analysis indicates that this ring can change its configuration to [6]radialene, therefore causing a loss of aromaticity and weakening the magnetic coupling. We have employed a combination of scanning tunneling microscopy (STM) and spectroscopy (STS) to investigate single Cu3-triplesalen and Cu3-triplesalalen molecules, the latter being designed to show an enhanced intramolecular spin coupling. The large molecules were deposited in situ using the unconventional techniques pulse injection and rapid heating. A thorough structural and spectroscopic analysis allows us to discuss the electronic properties of the two complexes, with a special focus on the state of the central carbon ring. We find that even small changes in the ligand structure have a drastic influence on the intramolecular spin coupling, which opens the way for an improved rational design of future SMMs.

  17. The Influence of the Instruction of Visual Design Principles on Improving Pre-Service Teachers' Visual Literacy

    Science.gov (United States)

    Yeh, Hsin-Te; Cheng, Yi-Chia

    2010-01-01

    This study investigated whether the instruction of visual design principles had an influence on pre-service teachers' perception and analysis (interpretation) of visual materials. In addition, the relationships between pre-service teachers' visual intelligence and their perception and analysis (interpretation) of visual materials were also…

  18. Visualizing dopamine released from living cells using a nanoplasmonic probe

    Science.gov (United States)

    Qin, W. W.; Wang, S. P.; Li, J.; Peng, T. H.; Xu, Y.; Wang, K.; Shi, J. Y.; Fan, C. H.; Li, D.

    2015-09-01

    We report the development of an ultrasensitive nanoplasmonic probe for discriminative detection and imaging of dopamine released from living cells. The sensing mechanism is based on the dopamine-induced seeded-growth of Au nanoparticles (Au NPs) that leads to the shift of the plasmon band. This platform allows for the detection of dopamine with a detection limit down to 0.25 pM within 1 min. This nanoplasmonic assay is further applied to visualize the release of dopamine from living rat pheochromocytoma (PC12) cells under ATP-stimulation with dark-field microscopy (DFM). The DFM results together with real time fluorescence imaging of PC12 cells stained with the Fluo calcium indicator, suggested that ATP stimulated-release of dopamine is concomitant with the Ca2+ influx, and the influx of Ca2+ is through ATP-activated channels instead of the voltage-gated Ca2+ channel (VGC).We report the development of an ultrasensitive nanoplasmonic probe for discriminative detection and imaging of dopamine released from living cells. The sensing mechanism is based on the dopamine-induced seeded-growth of Au nanoparticles (Au NPs) that leads to the shift of the plasmon band. This platform allows for the detection of dopamine with a detection limit down to 0.25 pM within 1 min. This nanoplasmonic assay is further applied to visualize the release of dopamine from living rat pheochromocytoma (PC12) cells under ATP-stimulation with dark-field microscopy (DFM). The DFM results together with real time fluorescence imaging of PC12 cells stained with the Fluo calcium indicator, suggested that ATP stimulated-release of dopamine is concomitant with the Ca2+ influx, and the influx of Ca2+ is through ATP-activated channels instead of the voltage-gated Ca2+ channel (VGC). Electronic supplementary information (ESI) available: Fig. S1-S4 and Table S1. See DOI: 10.1039/c5nr04433b

  19. Interactive Visualization Tools to Improve Learning and Teaching in Online Learning Environments

    Science.gov (United States)

    Kuosa, Kirsi; Distante, Damiano; Tervakari, Anne; Cerulo, Luigi; Fernández, Alejandro; Koro, Juho; Kailanto, Meri

    2016-01-01

    This paper presents two interactive visualization tools for learning management systems (LMS) in order to improve learning and teaching in online courses. The first tool was developed at the Intelligent Information Systems Laboratory (IISLab) at the Tampere University of Technology (TUT). The tool is used to analyse students' activity from…

  20. Engaging Direct Care Providers in Improving Infection Prevention and Control Practices Using Participatory Visual Methods.

    Science.gov (United States)

    Backman, Chantal; Bruce, Natalie; Marck, Patricia; Vanderloo, Saskia

    2016-01-01

    The purpose of this quality improvement project was to determine the feasibility of using provider-led participatory visual methods to scrutinize 4 hospital units' infection prevention and control practices. Methods included provider-led photo walkabouts, photo elicitation sessions, and postimprovement photo walkabouts. Nurses readily engaged in using the methods to examine and improve their units' practices and reorganize their work environment. PMID:26681499

  1. Improved Zirconia Oxygen-Separation Cell

    Science.gov (United States)

    Walsh, John V.; Zwissler, James G.

    1988-01-01

    Cell structure distributes feed gas more evenly for more efficent oxygen production. Multilayer cell structure containing passages, channels, tubes, and pores help distribute pressure evenly over zirconia electrolytic membrane. Resulting more uniform pressure distribution expected to improve efficiency of oxygen production.

  2. A Robot-Assisted Cell Manipulation System with an Adaptive Visual Servoing Method

    OpenAIRE

    Yu Xie; Feng Zeng; Wenming Xi; Yunlei Zhou; Houde Liu; Mingliang Chen

    2016-01-01

    Robot-assisted cell manipulation is gaining attention for its ability in providing high throughput and high precision cell manipulation for the biological industry. This paper presents a visual servo microrobotic system for cell microinjection. We investigated the automatic cell autofocus method that reduced the complexity of the system. Then, we produced an adaptive visual processing algorithm to detect the location of the cell and micropipette toward the uneven illumination problem. Fourtee...

  3. Improved biolistic transfection of hair cells.

    Directory of Open Access Journals (Sweden)

    Hongyu Zhao

    Full Text Available Transient transfection of hair cells has proven challenging. Here we describe modifications to the Bio-Rad Helios Gene Gun that, along with an optimized protocol, improve transfection of bullfrog, chick, and mouse hair cells. The increased penetrating power afforded by our method allowed us to transfect mouse hair cells from the basal side, through the basilar membrane; this configuration protects hair bundles from damage during the procedure. We characterized the efficiency of transfection of mouse hair cells with fluorescently-tagged actin fusion protein using both the optimized procedure and a published procedure; while the efficiency of the two methods was similar, the morphology of transfected hair cells was improved with the new procedure. In addition, using the improved method, we were able to transfect hair cells in the bullfrog sacculus and chick cochlea for the first time. We used fluorescent-protein fusions of harmonin b (USH1C and PMCA2 (ATP2B2; plasma-membrane Ca(2+-ATPase isoform 2 to examine protein distribution in hair cells. While PMCA2-EGFP localization was similar to endogenous PMCA2 detected with antibodies, high levels of harmonin-EGFP were found at stereocilia tapers in bullfrog and chick, but not mouse; by contrast, harmonin-EGFP was concentrated in stereocilia tips in mouse hair cells.

  4. Inducing attention not to blink: auditory entrainment improves conscious visual processing.

    Science.gov (United States)

    Ronconi, Luca; Pincham, Hannah L; Szűcs, Dénes; Facoetti, Andrea

    2016-09-01

    Our ability to allocate attention at different moments in time can sometimes fail to select stimuli occurring in close succession, preventing visual information from reaching awareness. This so-called attentional blink (AB) occurs when the second of two targets (T2) is presented closely after the first (T1) in a rapid serial visual presentation (RSVP). We hypothesized that entrainment to a rhythmic stream of stimuli-before visual targets appear-would reduce the AB. Experiment 1 tested the effect of auditory entrainment by presenting sounds with a regular or irregular interstimulus interval prior to a RSVP where T1 and T2 were separated by three possible lags (1, 3 and 8). Experiment 2 examined visual entrainment by presenting visual stimuli in place of auditory stimuli. Results revealed that irrespective of sensory modality, arrhythmic stimuli preceding the RSVP triggered an alerting effect that improved the T2 identification at lag 1, but impaired the recovery from the AB at lag 8. Importantly, only auditory rhythmic entrainment was effective in reducing the AB at lag 3. Our findings demonstrate that manipulating the pre-stimulus condition can reduce deficits in temporal attention characterizing the human cognitive architecture, suggesting innovative trainings for acquired and neurodevelopmental disorders. PMID:26215434

  5. Visual Fatigue Evaluation: Improvement of Reflected Glare on Touch Screen for Nuclear Power Plant

    International Nuclear Information System (INIS)

    The purpose of this research is to evaluate the visual fatigue of operators caused by glare problems in the main control room of nuclear power plant. Within the limitation in the main control room, reflectors were set under the light source which generates reflected glare on touch screens. Through avoiding the light directly shines on touch screens, reflected glare were eliminated. This research matched up the setting process of reflectors, evaluated the visual fatigue of operators, and collected user's opinions before reflector setting, after the first setting, and after the second setting. The design of reflectors could refer the result of evaluations and the collection of opinions. Nevertheless, the improvement of reflected glare on touch screens could be verified by this evaluations. The result showed that setting reflectors under the light source could eliminate reflected glare effectively, and the visual fatigue was reduced both on subject and object evaluations. However, the setting direction of reflectors has potential effect on operators' visual fatigue, so the real setting of reflectors still need to be evaluated completely. The near point accommodation could reflect the effect of visual fatigue caused by changes of lighting environment. Thus, the verification of new lighting environment according to the near point accommodation is suggested

  6. Improving the visualization and detection of tissue folds in whole slide images through color enhancement

    Directory of Open Access Journals (Sweden)

    Pinky A Bautista

    2010-01-01

    Full Text Available Objective : The objective of this paper is to improve the visualization and detection of tissue folds, which are prominent among tissue slides, from the pre-scan image of a whole slide image by introducing a color enhancement method that enables the differentiation between fold and non-fold image pixels. Method: The weighted difference between the color saturation and luminance of the image pixels is used as shifting factor to the original RGB color of the image. Results: Application of the enhancement method to hematoxylin and eosin (H&E stained images improves the visualization of tissue folds regardless of the colorimetric variations in the images. Detection of tissue folds after application of the enhancement also improves but the presence of nuclei, which are also stained dark like the folds, was found to sometimes affect the detection accuracy. Conclusion: The presence of tissue artifacts could affect the quality of whole slide images, especially that whole slide scanners select the focus points from the pre-scan image wherein the artifacts are indistinguishable from real tissue area. We have a presented in this paper an enhancement scheme that improves the visualization and detection of tissue folds from pre-scan images. Since the method works on the simulated pre-scan images its integration to the actual whole slide imaging process should also be possible.

  7. Endothelial cell-initiated extravasation of cancer cells visualized in zebrafish

    Directory of Open Access Journals (Sweden)

    Masamitsu Kanada

    2014-12-01

    Full Text Available The extravasation of cancer cells, a key step for distant metastasis, is thought to be initiated by disruption of the endothelial barrier by malignant cancer cells. An endothelial covering-type extravasation of cancer cells in addition to conventional cancer cell invasion-type extravasation was dynamically visualized in a zebrafish hematogenous metastasis model. The inhibition of VEGF-signaling impaired the invasion-type extravasation via inhibition of cancer cell polarization and motility. Paradoxically, the anti-angiogenic treatment showed the promotion, rather than the inhibition, of the endothelial covering-type extravasation of cancer cells, with structural changes in the endothelial walls. These findings may be a set of clues to the full understanding of the metastatic process as well as the metastatic acceleration by anti-angiogenic reagents observed in preclinical studies.

  8. Direct fuel cell product design improvement

    Energy Technology Data Exchange (ETDEWEB)

    Maru, H.C.; Farooque, M. [Energy Research Corp., Danbury, CT (United States)

    1996-12-31

    Significant milestones have been attained towards the technology development field testing and commercialization of direct fuel cell power plant since the 1994 Fuel Cell Seminar. Under a 5-year cooperative agreement with the Department of Energy signed in December 1994, Energy Research Corporation (ERC) has been developing the design for a MW-scale direct fuel cell power plant with input from previous technology efforts and the Santa Clara Demonstration Project. The effort encompasses product definition in consultation with the Fuel Cell Commercialization Group, potential customers, as well as extensive system design and packaging. Manufacturing process improvements, test facility construction, cell component scale up, performance and endurance improvements, stack engineering, and critical balance-of-plant development are also addressed. Major emphasis of this product design improvement project is on increased efficiency, compactness and cost reduction to establish a competitive place in the market. A 2.85 MW power plant with an efficiency of 58% and a footprint of 420 m{sup 2} has been designed. Component and subsystem testing is being conducted at various levels. Planning and preparation for verification of a full size prototype unit are in progress. This paper presents the results obtained since the last fuel cell seminar.

  9. Video game training to improve selective visual attention in older adults

    OpenAIRE

    Belchior, Patrícia; Marsiske, Michael; Sisco, Shannon M.; Yam, Anna; Bavelier, Daphne; Ball, Karlene; Mann, William C

    2013-01-01

    The current study investigated the effect of video game training on older adult’s useful field of view performance (the UFOV® test). Fifty-eight older adult participants were randomized to receive practice with the target action game (Medal of Honor), a placebo control arcade game (Tetris), a clinically validated UFOV training program, or into a no contact control group. Examining pretest–posttest change in selective visual attention, the UFOV improved significantly more than the game groups;...

  10. Visual Tracking Based on an Improved Online Multiple Instance Learning Algorithm

    OpenAIRE

    Li Jia Wang; Hua Zhang

    2016-01-01

    An improved online multiple instance learning (IMIL) for a visual tracking algorithm is proposed. In the IMIL algorithm, the importance of each instance contributing to a bag probability is with respect to their probabilities. A selection strategy based on an inner product is presented to choose weak classifier from a classifier pool, which avoids computing instance probabilities and bag probability M times. Furthermore, a feedback strategy is presented to update weak classifiers. In the feed...

  11. Improved micromorph tandem cell performance through enhanced top cell currents

    Energy Technology Data Exchange (ETDEWEB)

    Platz, R.; Vaucher, N.P.; Fischer, D.; Meier, J.; Shah, A. [Univ. de Neuchatel (Switzerland). Inst. de Microtechnique

    1997-12-31

    Two approaches to increasing the current in the amorphous silicon top cell of an amorphous silicon/microcrystalline silicon (a-Si:H/{micro}c-Si:H) tandem cell are presented. The goal is to raise the stabilized efficiency of such cells. The deposition of the amorphous top cell at higher than standard substrate temperature is shown to reduce the optical gap of the i-layer and to increase the current which is generated with a given i-layer thickness. Furthermore, a selectively reflecting ZnO interface layer between the component cells is presented as a viable tool for enhancing the current generation in the top cell by selective reflection of light. The authors present a micromorph tandem cell containing the amorphous top cell deposited at high substrate temperature, and additionally the ZnO mirror layer. A top cell thickness of 150 nm is shown to be sufficient to provide a current density of 13mA/cm{sup 2} in the top cell. Finally, the influence of such thin top cells on the stabilized efficiency of the tandem cell is investigated by experiment and by means of semi-empirical modeling. Model and experiment confirm that such reduced-gap top cells, together with current enhancement due to the mirror layer, have a high potential for improving the stabilized efficiency of micromorph tandem cells.

  12. Improved Gene Targeting through Cell Cycle Synchronization.

    Directory of Open Access Journals (Sweden)

    Vasiliki Tsakraklides

    Full Text Available Gene targeting is a challenge in organisms where non-homologous end-joining is the predominant form of recombination. We show that cell division cycle synchronization can be applied to significantly increase the rate of homologous recombination during transformation. Using hydroxyurea-mediated cell cycle arrest, we obtained improved gene targeting rates in Yarrowia lipolytica, Arxula adeninivorans, Saccharomyces cerevisiae, Kluyveromyces lactis and Pichia pastoris demonstrating the broad applicability of the method. Hydroxyurea treatment enriches for S-phase cells that are active in homologous recombination and enables previously unattainable genomic modifications.

  13. Audio-visual feedback improves the BCI performance in the navigational control of a humanoid robot.

    Science.gov (United States)

    Tidoni, Emmanuele; Gergondet, Pierre; Kheddar, Abderrahmane; Aglioti, Salvatore M

    2014-01-01

    Advancement in brain computer interfaces (BCI) technology allows people to actively interact in the world through surrogates. Controlling real humanoid robots using BCI as intuitively as we control our body represents a challenge for current research in robotics and neuroscience. In order to successfully interact with the environment the brain integrates multiple sensory cues to form a coherent representation of the world. Cognitive neuroscience studies demonstrate that multisensory integration may imply a gain with respect to a single modality and ultimately improve the overall sensorimotor performance. For example, reactivity to simultaneous visual and auditory stimuli may be higher than to the sum of the same stimuli delivered in isolation or in temporal sequence. Yet, knowledge about whether audio-visual integration may improve the control of a surrogate is meager. To explore this issue, we provided human footstep sounds as audio feedback to BCI users while controlling a humanoid robot. Participants were asked to steer their robot surrogate and perform a pick-and-place task through BCI-SSVEPs. We found that audio-visual synchrony between footsteps sound and actual humanoid's walk reduces the time required for steering the robot. Thus, auditory feedback congruent with the humanoid actions may improve motor decisions of the BCI's user and help in the feeling of control over it. Our results shed light on the possibility to increase robot's control through the combination of multisensory feedback to a BCI user. PMID:24987350

  14. Adapting the iSNOBAL model for improved visualization in a GIS environment

    Science.gov (United States)

    Johansen, W. J.; Delparte, D.

    2014-12-01

    Snowmelt is a primary means of crucial water resources in much of the western United States. Researchers are developing models that estimate snowmelt to aid in water resource management. One such model is the image snowcover energy and mass balance (iSNOBAL) model. It uses input climate grids to simulate the development and melting of snowpack in mountainous regions. This study looks at applying this model to the Reynolds Creek Experimental Watershed in southwestern Idaho, utilizing novel approaches incorporating geographic information systems (GIS). To improve visualization of the iSNOBAL model, we have adapted it to run in a GIS environment. This type of environment is suited to both the input grid creation and the visualization of results. The data used for input grid creation can be stored locally or on a web-server. Kriging interpolation embedded within Python scripts are used to create air temperature, soil temperature, humidity, and precipitation grids, while built-in GIS and existing tools are used to create solar radiation and wind grids. Additional Python scripting is then used to perform model calculations. The final product is a user-friendly and accessible version of the iSNOBAL model, including the ability to easily visualize and interact with model results, all within a web- or desktop-based GIS environment. This environment allows for interactive manipulation of model parameters and visualization of the resulting input grids for the model calculations. Future work is moving towards adapting the model further for use in a 3D gaming engine for improved visualization and interaction.

  15. Improved medical image modality classification using a combination of visual and textual features.

    Science.gov (United States)

    Dimitrovski, Ivica; Kocev, Dragi; Kitanovski, Ivan; Loskovska, Suzana; Džeroski, Sašo

    2015-01-01

    In this paper, we present the approach that we applied to the medical modality classification tasks at the ImageCLEF evaluation forum. More specifically, we used the modality classification databases from the ImageCLEF competitions in 2011, 2012 and 2013, described by four visual and one textual types of features, and combinations thereof. We used local binary patterns, color and edge directivity descriptors, fuzzy color and texture histogram and scale-invariant feature transform (and its variant opponentSIFT) as visual features and the standard bag-of-words textual representation coupled with TF-IDF weighting. The results from the extensive experimental evaluation identify the SIFT and opponentSIFT features as the best performing features for modality classification. Next, the low-level fusion of the visual features improves the predictive performance of the classifiers. This is because the different features are able to capture different aspects of an image, their combination offering a more complete representation of the visual content in an image. Moreover, adding textual features further increases the predictive performance. Finally, the results obtained with our approach are the best results reported on these databases so far. PMID:24997992

  16. A Robot-Assisted Cell Manipulation System with an Adaptive Visual Servoing Method

    Directory of Open Access Journals (Sweden)

    Yu Xie

    2016-06-01

    Full Text Available Robot-assisted cell manipulation is gaining attention for its ability in providing high throughput and high precision cell manipulation for the biological industry. This paper presents a visual servo microrobotic system for cell microinjection. We investigated the automatic cell autofocus method that reduced the complexity of the system. Then, we produced an adaptive visual processing algorithm to detect the location of the cell and micropipette toward the uneven illumination problem. Fourteen microinjection experiments were conducted with zebrafish embryos. A 100% success rate was achieved either in autofocus or embryo detection, which verified the robustness of the proposed automatic cell manipulation system.

  17. PEM fuel cells performance improvements by CFD

    International Nuclear Information System (INIS)

    , efficiency and accuracy will become one of the most cost effective ways of assisting in the development of new fuel cell technologies. Fuel cell technology presents huge economical and environmental potential in the next generation of power systems, from small portable fuel cells to large residential power plants. In the development of this new technology, detailed and accurate CFD modeling can effectively guide the improvements in fuel cell design so that optimal flow and energy management within fuel cells may be achieved. A comprehensive fuel cell modeling capability, which accounts for the detailed processes of the chemistry, electrochemistry, electric transport, heat generation and material stresses in the fuel cell, as well as the validated fuel cell modeling methodology, has not yet been fully established, so more work is required. (authors)

  18. Improvements in clinical and functional vision and perceived visual disability after first and second eye cataract surgery

    OpenAIRE

    Elliott, D; Patla, A.; Bullimore, M.

    1997-01-01

    AIMS—To determine the improvements in clinical and functional vision and perceived visual disability after first and second eye cataract surgery.
METHODS—Clinical vision (monocular and binocular high and low contrast visual acuity, contrast sensitivity, and disability glare), functional vision (face identity and expression recognition, reading speed, word acuity, and mobility orientation), and perceived visual disability (Activities of Daily Vision Scale) were measured in 25 subjects before a...

  19. Improving the spelling ability of Grade 3 learners through visual imaging teaching strategies

    Directory of Open Access Journals (Sweden)

    Annalene van Staden

    2011-08-01

    Full Text Available This paper discusses two key cognitive theories underlying spelling acquisition, i.e. the developmental stage theory and the overlapping waves theory. Within the developmental stage framework, learning to spell is viewed as a process of moving from spelling that represents sound to spelling that represents meaning, following a sequence of qualitatively distinct stages in a linear fashion. In contrast, proponents of the overlapping waves theory emphasise the use of different instructional approaches at any given time. This model is process-orientated and stresses the adaptation of strategies to meet the needs of the task. Other researchers maintain that spelling is a natural process and emphasise the importance of invented spelling practices and creative writing embedded in whole-language programmes. There is, however, a lack of research validating the efficacy of an exclusively naturalistic approach to spelling. In general, research findings support a combination of incidental learning and direct instruction as most beneficial for learners with spelling problems. Thus, this study was undertaken to develop a visual imagery programme for Grade 3 learners by compromising between direct instruction in specific spelling skills (i.e. visual imaging strategies whilst also immersing learners in meaningful authentic reading activities. It was hypothesised that the spelling abilities of Afrikaans-speaking Grade 3 learners can be improved significantly by exposing them to a spelling programme that focuses on visual imaging, immediate feedback and self-correcting strategies. Researchers opposed to visual teaching methods for spelling moreover postulate, among other things, that learners with auditory preferences will not benefit from a visual approach to the teaching of spelling. In this empirical study the possible relation between preferential learning styles and spelling performance was also investigated.

  20. Improving aviation safety with information visualization: Airflow hazard display for helicopter pilots

    Science.gov (United States)

    Aragon, Cecilia Rodriguez

    Many aircraft accidents each year are caused by encounters with airflow hazards near the ground, such as vortices or other turbulence. While such hazards frequently pose problems to fixed-wing aircraft, they are especially dangerous to helicopters, whose pilots often have to operate into confined areas or under operationally stressful conditions. Pilots are often unaware of these invisible hazards while simultaneously attending to other aspects of aircraft operation close to the ground. Recent advances in aviation sensor technology offer the potential for aircraft-based sensors that can gather large amounts of airflow velocity data in real time. This development is likely to lead to the production of onboard detection systems that can convey detailed, specific information about imminent airflow hazards to pilots. A user interface is required that can present extensive amounts of data to the pilot in a useful manner in real time, yet not distract from the pilot's primary task of flying the aircraft. In this dissertation, we address the question of how best to present safety-critical visual information to a cognitively overloaded user in real time. We designed an airflow hazard visualization system according to user-centered design principles, implemented the system in a high fidelity, aerodynamically realistic rotorcraft flight simulator, and evaluated it via usability studies with experienced military and civilian helicopter pilots. We gathered both subjective data from the pilots' evaluations of the visualizations, and objective data from the pilots' performance during the landing simulations. Our study demonstrated that information visualization of airflow hazards, when presented to helicopter pilots in the simulator, dramatically improved their ability to land safely under turbulent conditions. Although we focused on one particular aviation application, the results may be relevant to user interfaces and information visualization in other safety

  1. Experience of in-cell visual inspection using CCD camera in hot cell of Reprocessing Plant

    International Nuclear Information System (INIS)

    This paper describes the selection, customization and operating experience of the visual inspection system for the hot cell of a Reprocessing Plant. For process equipment such as fuel chopping machine, dissolver, centrifuge, centrifugal extractors etc., viewing of operations and maintenance using manipulators is required. For this, the service of in-cell camera is essential. The ambience of the hot cell of Compact facility for Reprocessing of Advanced fuels in Lead cell (CORAL) for the reprocessing of fast reactor spent fuel has high gamma radiation and acidic vapors. Black and white Charge Coupled Device (CCD) camera has been used in CORAL incorporating in-house modifications to suit the operating ambient conditions, thereby extending the operating life of the camera. (author)

  2. Spatially valid proprioceptive cues improve the detection of a visual stimulus

    DEFF Research Database (Denmark)

    Jackson, Carl P T; Miall, R Chris; Balslev, Daniela

    2010-01-01

    Vision and proprioception are the main sensory modalities that convey hand location and direction of movement. Fusion of these sensory signals into a single robust percept is now well documented. However, it is not known whether these modalities also interact in the spatial allocation of attention......, which has been demonstrated for other modality pairings. The aim of this study was to test whether proprioceptive signals can spatially cue a visual target to improve its detection. Participants were instructed to use a planar manipulandum in a forward reaching action and determine during this movement...... whether a near-threshold visual target appeared at either of two lateral positions. The target presentation was followed by a masking stimulus, which made its possible location unambiguous, but not its presence. Proprioceptive cues were given by applying a brief lateral force to the participant's arm...

  3. Retrospective cues based on object features improve visual working memory performance in older adults.

    Science.gov (United States)

    Gilchrist, Amanda L; Duarte, Audrey; Verhaeghen, Paul

    2016-01-01

    Research with younger adults has shown that retrospective cues can be used to orient top-down attention toward relevant items in working memory. We examined whether older adults could take advantage of these cues to improve memory performance. Younger and older adults were presented with visual arrays of five colored shapes; during maintenance, participants were presented either with an informative cue based on an object feature (here, object shape or color) that would be probed, or with an uninformative, neutral cue. Although older adults were less accurate overall, both age groups benefited from the presentation of an informative, feature-based cue relative to a neutral cue. Surprisingly, we also observed differences in the effectiveness of shape versus color cues and their effects upon post-cue memory load. These results suggest that older adults can use top-down attention to remove irrelevant items from visual working memory, provided that task-relevant features function as cues. PMID:26208404

  4. How Visual Management for Continuous Improvement Might Guide and Affect Hospital Staff: A Case Study.

    Science.gov (United States)

    Ulhassan, Waqar; von Thiele Schwarz, Ulrica; Westerlund, Hugo; Sandahl, Christer; Thor, Johan

    2015-01-01

    Visual management (VM) tools such as whiteboards, often employed in Lean thinking applications, are intended to be helpful in improving work processes in different industries including health care. It remains unclear, however, how VM is actually applied in health care Lean interventions and how it might influence the clinical staff. We therefore examined how Lean-inspired VM using whiteboards for continuous improvement efforts related to the hospital staff's work and collaboration. Within a case study design, we combined semistructured interviews, nonparticipant observations, and photography on 2 cardiology wards. The fate of VM differed between the 2 wards; in one, it was well received by the staff and enhanced continuous improvement efforts, whereas in the other ward, it was not perceived to fit in the work flow or to make enough sense in order to be sustained. Visual management may enable the staff and managers to allow communication across time and facilitate teamwork by enabling the inclusion of team members who are not present simultaneously; however, its adoption and value seem contingent on finding a good fit with the local context. A combination of continuous improvement and VM may be helpful in keeping the staff engaged in the change process in the long run. PMID:26426324

  5. Vascular Cell Induction Culture System Using Arabidopsis Leaves (VISUAL) Reveals the Sequential Differentiation of Sieve Element-Like Cells.

    Science.gov (United States)

    Kondo, Yuki; Nurani, Alif Meem; Saito, Chieko; Ichihashi, Yasunori; Saito, Masato; Yamazaki, Kyoko; Mitsuda, Nobutaka; Ohme-Takagi, Masaru; Fukuda, Hiroo

    2016-06-01

    Cell differentiation is a complex process involving multiple steps, from initial cell fate specification to final differentiation. Procambial/cambial cells, which act as vascular stem cells, differentiate into both xylem and phloem cells during vascular development. Recent studies have identified regulatory cascades for xylem differentiation. However, the molecular mechanism underlying phloem differentiation is largely unexplored due to technical challenges. Here, we established an ectopic induction system for phloem differentiation named Vascular Cell Induction Culture System Using Arabidopsis Leaves (VISUAL). Our results verified similarities between VISUAL-induced Arabidopsis thaliana phloem cells and in vivo sieve elements. We performed network analysis using transcriptome data with VISUAL to dissect the processes underlying phloem differentiation, eventually identifying a factor involved in the regulation of the master transcription factor gene APL Thus, our culture system opens up new avenues not only for genetic studies of phloem differentiation, but also for future investigations of multidirectional differentiation from vascular stem cells. PMID:27194709

  6. Treatment of one case of cerebral palsy combined with posterior visual pathway injury using autologous bone marrow mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Li Min

    2012-05-01

    Full Text Available Abstract Background Cerebral palsy is currently one of the major diseases that cause severe paralysis of the nervous system in children; approximately 9–30% of cerebral palsy patients are also visually impaired, for which no effective treatment is available. Bone marrow mesenchymal stem cells (BMSCs have very strong self-renewal, proliferation, and pluripotent differentiation potentials. Therefore, autologous BMSC transplantation has become a novel method for treating cerebral palsy. Methods An 11-year-old boy had a clear history of dystocia and asphyxia after birth; at the age of 6 months, the family members observed that his gaze roamed and noted that he displayed a lack of attention. A brain MRI examination at the age of 7 years showed that the child had cerebral palsy with visual impairment (i.e., posterior visual pathway injury. The patient was hospitalized for 20 days and was given four infusions of intravenous autologous BMSCs. Before transplantation and 1, 6, and 12 months after transplantation, a visual evoked potential test, an electrocardiogram, routine blood tests, and liver and kidney function tests were performed. Results The patient did not have any adverse reactions during hospitalization or postoperative follow-up. After discharge, the patient could walk more smoothly than he could before transplantation; furthermore, his vision significantly improved 6 months after transplantation, which was also supported by the electrophysiological examinations. Conclusions The clinical application of BMSCs is effective for improving vision in a patient with cerebral palsy combined with visual impairment.

  7. Multivariable manual control with simultaneous visual and auditory presentation of information. [for improved compensatory tracking performance of human operator

    Science.gov (United States)

    Uhlemann, H.; Geiser, G.

    1975-01-01

    Multivariable manual compensatory tracking experiments were carried out in order to determine typical strategies of the human operator and conditions for improvement of his performance if one of the visual displays of the tracking errors is supplemented by an auditory feedback. Because the tracking error of the system which is only visually displayed is found to decrease, but not in general that of the auditorally supported system, it was concluded that the auditory feedback unloads the visual system of the operator who can then concentrate on the remaining exclusively visual displays.

  8. An improved visualization-based force-measurement technique for short-duration hypersonic facilities

    Energy Technology Data Exchange (ETDEWEB)

    Laurence, Stuart J.; Karl, Sebastian [Institute of Aerodynamics and Flow Technology, Spacecraft Section, German Aerospace Center (DLR), Goettingen (Germany)

    2010-06-15

    This article is concerned with describing and exploring the limitations of an improved version of a recently proposed visualization-based technique for the measurement of forces and moments in short-duration hypersonic wind tunnels. The technique is based on tracking the motion of a free-flying body over a sequence of high-speed visualizations; while this idea is not new in itself, the use of high-speed digital cinematography combined with a highly accurate least-squares tracking algorithm allows improved results over what have been previously possible with such techniques. The technique precision is estimated through the analysis of artificially constructed and experimental test images, and the resulting error in acceleration measurements is characterized. For wind-tunnel scale models, position measurements to within a few microns are shown to be readily attainable. Image data from two previous experimental studies in the T5 hypervelocity shock tunnel are then reanalyzed with the improved technique: the uncertainty in the mean drag acceleration is shown to be reduced to the order of the flow unsteadiness, 2-3%, and time-resolved acceleration measurements are also shown to be possible. The response time of the technique for the configurations studied is estimated to be {proportional_to}0.5 ms. Comparisons with computations using the DLR TAU code also yield agreement to within the overall experimental uncertainty. Measurement of the pitching moment for blunt geometries still appears challenging, however. (orig.)

  9. Planetary rover navigation: improving visual odometry via additional images and multisensor fusion

    Science.gov (United States)

    Casalino, G.; Zereik, E.; Simetti, E.; Turetta, A.; Torelli, S.; Sperindé, A.

    2013-12-01

    Visual odometry (VO) is very important for a mobile robot, above all in a planetary scenario, to accurately estimate the rover occurred motion. The present work deals with the possibility to improve a previously developed VO technique by means of additional image processing, together with suitable mechanisms such as the classical Extended/Iterated Kalman Filtering and also Sequence Estimators. The possible employment of both techniques is then addressed and, consequently, a better behaving integration scheme is proposed. Moreover, the eventuality of exploiting other localization sensors is also investigated, leading to a final multisensor scheme.

  10. Improving visual functions in adult amblyopia with combined perceptual training and transcranial random noise stimulation (tRNS): a pilot study

    OpenAIRE

    Campana, Gianluca; Camilleri, Rebecca; Pavan, Andrea; Veronese, Antonella; Lo Giudice, Giuseppe

    2014-01-01

    Amblyopia is a visual disorder due to an abnormal pattern of functional connectivity of the visual cortex and characterized by several visual deficits of spatial vision including impairments of visual acuity (VA) and of the contrast sensitivity function (CSF). Despite being a developmental disorder caused by reduced visual stimulation during early life (critical period), several studies have shown that extensive visual perceptual training can improve VA and CSF in people with amblyopia even i...

  11. THE IMPROVEMENT OF AUDIO-VISUAL BASED DANCE APPRECIATION LEARNING AMONG PRIMARY TEACHER EDUCATION STUDENTS OF MAKASSAR STATE UNIVERSITY

    OpenAIRE

    Wahira

    2014-01-01

    This research aimed to improve the skill in appreciating dances owned by the students of Primary Teacher Education of Makassar State University, to improve the perception towards audio-visual based art appreciation, to increase the students’ interest in audio-visual based art education subject, and to increase the students’ responses to the subject. This research was classroom action research using the research design created by Kemmis & MC. Taggart, which was conducted to 42 students of Prim...

  12. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    Energy Technology Data Exchange (ETDEWEB)

    H.C. Maru; M. Farooque

    2004-08-01

    The ongoing program is designed to advance the carbonate fuel cell technology from full-size proof-of-concept field test to the commercial design. DOE has been funding Direct FuelCell{reg_sign} (DFC{reg_sign}) development at FuelCell Energy, Inc. (FCE) for stationary power plant applications. The program efforts are focused on technology and system optimization for cost reduction, leading to commercial design development and prototype system field trials. FCE, Danbury, CT, is a world-recognized leader for the development and commercialization of high efficiency fuel cells that can generate clean electricity at power stations, or at distributed locations near the customers such as hospitals, schools, universities, hotels and other commercial and industrial applications. FCE has designed three different fuel cell power plant models (DFC300A, DFC1500 and DFC3000). FCE's power plants are based on its patented DFC{reg_sign} technology, where the fuel is directly fed to the fuel cell and hydrogen is generated internally. These power plants offer significant advantages compared to the existing power generation technologies--higher fuel efficiency, significantly lower emissions, quieter operation, flexible siting and permitting requirements, scalability and potentially lower operating costs. Also, the exhaust heat by-product can be used for cogeneration applications such as high-pressure steam, district heating and air conditioning. Several FCE sub-megawatt power plants are currently operating in Europe, Japan and the US. Because hydrogen is generated directly within the fuel cell module from readily available fuels such as natural gas and waste water treatment gas, DFC power plants are ready today and do not require the creation of a hydrogen infrastructure. Product improvement progress made during the reporting period in the areas of technology, manufacturing processes, cost reduction and balance of plant equipment designs is discussed in this report.

  13. Circadian plasticity in photoreceptor cells controls visual coding efficiency in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Martin Barth

    Full Text Available In the fly Drosophila melanogaster, neuronal plasticity of synaptic terminals in the first optic neuropil, or lamina, depends on early visual experience within a critical period after eclosion. The current study revealed two additional and parallel mechanisms involved in this type of synaptic terminal plasticity. First, an endogenous circadian rhythm causes daily oscillations in the volume of photoreceptor cell terminals. Second, daily visual experience precisely modulates the circadian time course and amplitude of the volume oscillations that the photoreceptor-cell terminals undergo. Both mechanisms are separable in their molecular basis. We suggest that the described neuronal plasticity in Drosophila ensures continuous optimal performance of the visual system over the course of a 24 h-day. Moreover, the sensory system of Drosophila cannot only account for predictable, but also for acute, environmental changes. The volumetric changes in the synaptic terminals of photoreceptor cells are accompanied by circadian and light-induced changes of presynaptic ribbons as well as extensions of epithelial glial cells into the photoreceptor terminals, suggesting that the architecture of the lamina is altered by both visual exposure and the circadian clock. Clock-mutant analysis and the rescue of PER protein rhythmicity exclusively in all R1-6 cells revealed that photoreceptor-cell plasticity is autonomous and sufficient to control visual behavior. The strength of a visually guided behavior, the optomotor turning response, co-varies with synaptic-terminal volume oscillations of photoreceptor cells when elicited at low light levels. Our results show that behaviorally relevant adaptive processing of visual information is performed, in part, at the level of visual input level.

  14. Improving the discrimination of hand motor imagery via virtual reality based visual guidance.

    Science.gov (United States)

    Liang, Shuang; Choi, Kup-Sze; Qin, Jing; Pang, Wai-Man; Wang, Qiong; Heng, Pheng-Ann

    2016-08-01

    While research on the brain-computer interface (BCI) has been active in recent years, how to get high-quality electrical brain signals to accurately recognize human intentions for reliable communication and interaction is still a challenging task. The evidence has shown that visually guided motor imagery (MI) can modulate sensorimotor electroencephalographic (EEG) rhythms in humans, but how to design and implement efficient visual guidance during MI in order to produce better event-related desynchronization (ERD) patterns is still unclear. The aim of this paper is to investigate the effect of using object-oriented movements in a virtual environment as visual guidance on the modulation of sensorimotor EEG rhythms generated by hand MI. To improve the classification accuracy on MI, we further propose an algorithm to automatically extract subject-specific optimal frequency and time bands for the discrimination of ERD patterns produced by left and right hand MI. The experimental results show that the average classification accuracy of object-directed scenarios is much better than that of non-object-directed scenarios (76.87% vs. 69.66%). The result of the t-test measuring the difference between them is statistically significant (p = 0.0207). When compared to algorithms based on fixed frequency and time bands, contralateral dominant ERD patterns can be enhanced by using the subject-specific optimal frequency and the time bands obtained by our proposed algorithm. These findings have the potential to improve the efficacy and robustness of MI-based BCI applications. PMID:27282228

  15. Active training and driving-specific feedback improve older drivers' visual search prior to lane changes

    Directory of Open Access Journals (Sweden)

    Lavallière Martin

    2012-03-01

    Full Text Available Abstract Background Driving retraining classes may offer an opportunity to attenuate some effects of aging that may alter driving skills. Unfortunately, there is evidence that classroom programs (driving refresher courses do not improve the driving performance of older drivers. The aim of the current study was to evaluate if simulator training sessions with video-based feedback can modify visual search behaviors of older drivers while changing lanes in urban driving. Methods In order to evaluate the effectiveness of the video-based feedback training, 10 older drivers who received a driving refresher course and feedback about their driving performance were tested with an on-road standardized evaluation before and after participating to a simulator training program (Feedback group. Their results were compared to a Control group (12 older drivers who received the same refresher course and in-simulator active practice as the Feedback group without receiving driving-specific feedback. Results After attending the training program, the Control group showed no increase in the frequency of the visual inspection of three regions of interests (rear view and left side mirrors, and blind spot. In contrast, for the Feedback group, combining active training and driving-specific feedbacks increased the frequency of blind spot inspection by 100% (32.3 to 64.9% of verification before changing lanes. Conclusions These results suggest that simulator training combined with driving-specific feedbacks helped older drivers to improve their visual inspection strategies, and that in-simulator training transferred positively to on-road driving. In order to be effective, it is claimed that driving programs should include active practice sessions with driving-specific feedbacks. Simulators offer a unique environment for developing such programs adapted to older drivers' needs.

  16. Visiting Richard Serra’s Promenade sculpture improves postural control and judgment of subjective visual vertical.

    Directory of Open Access Journals (Sweden)

    Zoï eKapoula

    2014-12-01

    Full Text Available Body sway while maintaining an upright quiet stance reflects an active process of balance based on the integration of visual, vestibular, somatosensory and proprioceptive inputs. Richard Serra’s Promenade sculpture featured in the 2008 Monumenta exhibition at the Grand Palais in Paris, France is herein hypothesised to have stimulated the body’s vertical and longitudinal axes as it showcased 5 monumental rectangular solids pitched at a 1.69° angle.Using computerised dynamic posturography we measured the body sway of 23 visitors when fixating a cross, or when observing the artwork (fixating it or actively exploring it with eye movements before and after walking around and alongside the sculpture (i.e., before and after a promenade. A first fixation at the sculpture increased medio-lateral stability (in terms of spectral power of body sway. Eye movement exploration in the depth of the sculpture increased antero-posterior stability (in terms of spectral power and cancelling time of body sway at the expense of medio-lateral stability (in terms of cancelling time. Moreover, a medio-lateral instability associated with eye movement exploration before the promenade (in terms of body sway sensu stricto was cancelled after the promenade. Finally, the overall medio-lateral stability (in terms of spectral power increased after the promenade.Fourteen additional visitors were asked to sit in a dark room and adjust a luminous line to what they considered to be the earth-vertical axis. The promenade executed within the sculpted environment afforded by Serra’s monumental statuary works resulted in significantly improved performances on the subjective visual vertical test.We attribute these effects to the sculpted environment provided by the exhibition which may have acted as a kind of physiologic training ground thereby improving the visitors’ overall sense of visual perspective, equilibrium and gravity.

  17. Improved orbits and parallaxes for eight visual binaries with unrealistic previous masses using the Hipparcos parallax

    CERN Document Server

    Docobo, J A; Malkov, O Yu; Campo, P P; Chulkov, D A

    2016-01-01

    Improved orbits are presented for the visual binaries WDS 02366+1227, WDS 02434-6643, WDS 03244-1539, WDS 08507+1800, WDS 09128-6055, WDS 11532-1540, WDS 17375+2419, and WDS 22408-0333. The latest orbits for these binaries were demonstrating a great inconsistency between the systemic mass obtained through Kepler's Third Law and that calculated as a sum of their components' mass through standard mass-luminosity and mass-spectrum relationships. Our improvement allowed us to obtain consistent systemic masses for WDS 02434-6643 and WDS 09128-6055 without a need for changing the Hipparcos parallax. For the remaining 6 pairs, we suggest the use of their dynamical parallax as a reliable distance estimate unless more precise parallax is reported. Astrophysical and dynamical properties of individual objects are discussed.

  18. Improving patient safety through education: how visual recognition skills may reduce medication errors on surgical wards

    Directory of Open Access Journals (Sweden)

    Christopher R. Davis

    2011-12-01

    Full Text Available Medication errors compromise patient safety and cost £500m per annum in the UK. Patients who forget the name of their medication may describe the appearance to the doctor. Nurses use recognition skills to assist in safe administration of medications. This study quantifies healthcare professionals’ accuracy in visually identifying medications. Members of the multidisciplinary team were asked to identify five commonly prescribed medications. Mean recognition rate (MRR was defined as the percentage of correct responses. Dunn’s multiple comparison tests quantified inter-professional variation. Fifty-six participants completed the study (93% response rate. MRRs were: pharmacists 61%; nurses 35%; doctors 19%; physiotherapists 11%. Pharmacists’ MRR were significantly higher than both doctors and physiotherapists (P<0.001. Nurses’ MRR was statistically comparable to pharmacists (P>0.05. The majority of healthcare professionals cannot accurately identify commonly prescribed medications on direct visualization. By increasing access to medication identification resources and improving undergraduate education and postgraduate training for all healthcare professionals, errors may be reduced and patient safety improved.

  19. Improving visual functions in adult amblyopia with combined perceptual training and transcranial random noise stimulation (tRNS

    Directory of Open Access Journals (Sweden)

    Gianluca eCampana

    2014-12-01

    Full Text Available Amblyopia is a visual disorder due to an abnormal pattern of functional connectivity of the visual cortex and characterized by several visual deficits of spatial vision including impairments of visual acuity (VA and of the contrast sensitivity function (CSF. Despite being a developmental disorder caused by reduced visual stimulation during early life (critical period, several studies have shown that extensive visual perceptual training can improve VA and CSF in people with amblyopia even in adulthood. With the present study we assessed whether a much shorter perceptual training regime, in association with high-frequency transcranial electrical stimulation (hf-tRNS, was able to improve visual functions in a group of adult participants with amblyopia. Results show that, in comparison with previous studies where a large number sessions with a similar training regime were used (Polat, Ma-Naim, Belkin & Sagi, 2004, here just eight sessions of training in contrast detection under lateral masking conditions combined with hf-tRNS, were able to substantially improve VA and CSF in adults with amblyopia.

  20. Visualization and orchestration of the dynamic molecular society in cells

    Institute of Scientific and Technical Information of China (English)

    Xuebiao Yao; Guowei Fang

    2009-01-01

    @@ Visualization of specific molecules and their interactions in real space and time is essential to delineate how cellular plasticity and dynamics are achieved and orchestrated as perturbation of cellular plasticity and dynamics is detrimental to health. Elucidation of cellular dynamics requires molecular imaging at nanometer scale at millisecond resolution. The 1st International Conference on Cellular Dynamics and Chemical Biology held in Hefei, China (from 12 September to 15 September,2008) launched the quest by bringing synergism among photonics, chemistry and biology.

  1. Pineal photoreceptor cells are required for maintaining the circadian rhythms of behavioral visual sensitivity in zebrafish.

    Directory of Open Access Journals (Sweden)

    Xinle Li

    Full Text Available In non-mammalian vertebrates, the pineal gland functions as the central pacemaker that regulates the circadian rhythms of animal behavior and physiology. We generated a transgenic zebrafish line [Tg(Gnat2:gal4-VP16/UAS:nfsB-mCherry] in which the E. coli nitroreductase is expressed in pineal photoreceptor cells. In developing embryos and young adults, the transgene is expressed in both retinal and pineal photoreceptor cells. During aging, the expression of the transgene in retinal photoreceptor cells gradually diminishes. By 8 months of age, the Gnat2 promoter-driven nitroreductase is no longer expressed in retinal photoreceptor cells, but its expression in pineal photoreceptor cells persists. This provides a tool for selective ablation of pineal photoreceptor cells, i.e., by treatments with metronidazole. In the absence of pineal photoreceptor cells, the behavioral visual sensitivity of the fish remains unchanged; however, the circadian rhythms of rod and cone sensitivity are diminished. Brief light exposures restore the circadian rhythms of behavioral visual sensitivity. Together, the data suggest that retinal photoreceptor cells respond to environmental cues and are capable of entraining the circadian rhythms of visual sensitivity; however, they are insufficient for maintaining the rhythms. Cellular signals from the pineal photoreceptor cells may be required for maintaining the circadian rhythms of visual sensitivity.

  2. Visualizing and quantifying cell phenotype using soft X-ray tomography

    OpenAIRE

    McDermott, Gerry; Fox, Douglas M.; Epperly, Lindsay; Wetzler, Modi; Barron, Annelise E.; Le Gros, Mark A.; Larabell, Carolyn A.

    2012-01-01

    Soft X-ray tomography (SXT) is an imaging technique capable of characterizing and quantifying the structural phenotype of cells. In particular, SXT is used to visualize the internal architecture of fully hydrated, intact eukaryotic and prokaryotic cells at high spatial resolution (50 nm or better). Image contrast in SXT is derived from the biochemical composition of the cell, and obtained without the need to use potentially damaging contrast-enhancing agents, such as heavy metals. The cells a...

  3. Xenopus laevis retinal ganglion cell dendritic arbors develop independently of visual stimulation

    OpenAIRE

    Barbara Lom; Rebecca L. Rigel

    2004-01-01

    Newly formed neurons must locate their appropriate target cells and then form synaptic connections with these targets in order to establish a functional nervous system. In the vertebrate retina, retinal ganglion cell (RGC) dendrites extend from the cell body and form synapses with nearby amacrine and bipolar cells. RGC axons, however, exit the retina and synapse with the dendrites of midbrain neurons in the optic tectum. We examined how visual stimulation influenced Xenopus RGC dendritic arbo...

  4. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    Energy Technology Data Exchange (ETDEWEB)

    H.C. Maru; M. Farooque

    2005-03-01

    The program was designed to advance the carbonate fuel cell technology from full-size proof-of-concept field test to the commercial design. DOE has been funding Direct FuelCell{reg_sign} (DFC{reg_sign}) development at FuelCell Energy, Inc. (FCE, formerly Energy Research Corporation) from an early state of development for stationary power plant applications. The current program efforts were focused on technology and system development, and cost reduction, leading to commercial design development and prototype system field trials. FCE, in Danbury, CT, is a world-recognized leader for the development and commercialization of high efficiency fuel cells that can generate clean electricity at power stations, or at distributed locations near the customers such as hospitals, schools, universities, hotels and other commercial and industrial applications. FCE has designed three different fuel cell power plant models (DFC300A, DFC1500 and DFC3000). FCE's power plants are based on its patented DFC{reg_sign} technology, where a hydrocarbon fuel is directly fed to the fuel cell and hydrogen is generated internally. These power plants offer significant advantages compared to the existing power generation technologies--higher fuel efficiency, significantly lower emissions, quieter operation, flexible siting and permitting requirements, scalability and potentially lower operating costs. Also, the exhaust heat by-product can be used for cogeneration applications such as high-pressure steam, district heating and air conditioning. Several sub-MW power plants based on the DFC design are currently operating in Europe, Japan and the US. Several one-megawatt power plant design was verified by operation on natural gas at FCE. This plant is currently installed at a customer site in King County, WA under another US government program and is currently in operation. Because hydrogen is generated directly within the fuel cell module from readily available fuels such as natural gas and

  5. Performance improvements from imagery:evidence that internal visual imagery is superior to external visual imagery for slalom performance

    Directory of Open Access Journals (Sweden)

    Nichola eCallow

    2013-10-01

    Full Text Available We report three experiments investigating the hypothesis that use of internal visual imagery (IVI would be superior to external visual imagery (EVI for the performance of different slalom-based motor tasks. In Experiment 1, three groups of participants (IVI, EVI, and a control group performed a driving-simulation slalom task. The IVI group achieved significantly quicker lap times than EVI and the control group. In Experiment 2, participants performed a downhill running slalom task under both IVI and EVI conditions. Performance was again quickest in the IVI compared to EVI condition, with no differences in accuracy. Experiment 3 used the same group design as Experiment 1, but with participants performing a downhill ski-slalom task. Results revealed the IVI group to be significantly more accurate than the control group, with no significant differences in time taken to complete the task. These results support the beneficial effects of IVI for slalom-based tasks, and significantly advances our knowledge related to the differential effects of visual imagery perspectives on motor performance.

  6. A texture-based framework for improving CFD data visualization in a virtual environment

    Energy Technology Data Exchange (ETDEWEB)

    Gerrick O' Ron Bivins

    2005-05-05

    In the field of computational fluid dynamics (CFD) accurate representations of fluid phenomena can be simulated hut require large amounts of data to represent the flow domain. Most datasets generated from a CFD simulation can be coarse, {approx}10,000 nodes or cells, or very fine with node counts on the order of 1,000,000. A typical dataset solution can also contain multiple solutions for each node, pertaining to various properties of the flow at a particular node. Scalar properties such as density, temperature, pressure, and velocity magnitude are properties that are typically calculated and stored in a dataset solution. Solutions are not limited to just scalar properties. Vector quantities, such as velocity, are also often calculated and stored for a CFD simulation. Accessing all of this data efficiently during runtime is a key problem for visualization in an interactive application. Understanding simulation solutions requires a post-processing tool to convert the data into something more meaningful. Ideally, the application would present an interactive visual representation of the numerical data for any dataset that was simulated while maintaining the accuracy of the calculated solution. Most CFD applications currently sacrifice interactivity for accuracy, yielding highly detailed flow descriptions hut limiting interaction for investigating the field.

  7. A texture-based frameowrk for improving CFD data visualization in a virtual environment

    Energy Technology Data Exchange (ETDEWEB)

    Biveins, Gerrick O' Ron

    2005-05-01

    In the field of computational fluid dynamics (CFD) accurate representations of fluid phenomena can be simulated but require large amounts of data to represent the flow domain. Most datasets generated from a CFD simulation can be coarse, {approx} 10,000 nodes or cells, or very fine with node counts on the order of 1,000,000. A typical dataset solution can also contain multiple solutions for each node, pertaining to various properties of the flow at a particular node. Scalar properties such as density, temperature, pressure, and velocity magnitude are properties that are typically calculated and stored in a dataset solution. Solutions are not limited to just scalar properties. Vector quantities, such as velocity, are also often calculated and stored for a CFD simulation. Accessing all of this data efficiently during runtime is a key problem for visualization in an interactive application. Understanding simulation solutions requires a post-processing tool to convert the data into something more meaningful. Ideally, the application would present an interactive visual representation of the numerical data for any dataset that was simulated while maintaining the accuracy of the calculated solution. Most CFD applications currently sacrifice interactivity for accuracy, yielding highly detailed flow descriptions but limiting interaction for investigating the field.

  8. Improving scientists' interaction with complex computational-visualization environments based on a distributed grid infrastructure.

    Science.gov (United States)

    Kalawsky, R S; O'Brien, J; Coveney, P V

    2005-08-15

    The grid has the potential to transform collaborative scientific investigations through the use of closely coupled computational and visualization resources, which may be geographically distributed, in order to harness greater power than is available at a single site. Scientific applications to benefit from the grid include visualization, computational science, environmental modelling and medical imaging. Unfortunately, the diversity, scale and location of the required resources can present a dilemma for the scientific worker because of the complexity of the underlying technology. As the scale of the scientific problem under investigation increases so does the nature of the scientist's interaction with the supporting infrastructure. The increased distribution of people and resources within a grid-based environment can make resource sharing and collaborative interaction a critical factor to their success. Unless the technological barriers affecting user accessibility are reduced, there is a danger that the only scientists to benefit will be those with reasonably high levels of computer literacy. This paper examines a number of important human factors of user interaction with the grid and expresses this in the context of the science undertaken by RealityGrid, a project funded by the UK e-Science programme. Critical user interaction issues will also be highlighted by comparing grid computational steering with supervisory control systems for local and remote access to the scientific environment. Finally, implications for future grid developers will be discussed with a particular emphasis on how to improve the scientists' access to what will be an increasingly important resource. PMID:16099754

  9. Using Visualized Matrix Effects to Develop and Improve LC-MS/MS Bioanalytical Methods, Taking TRAM-34 as an Example.

    Directory of Open Access Journals (Sweden)

    Jia-Hung Ye

    Full Text Available Matrix effects (MEs continue to be an obstacle in the development of the LC-MS/MS method, with phospholipids being the major cause of MEs. Changing the mobile phase has been a common strategy to reduce MEs; however, the underlying mechanism is unclear. "In-source multiple-reaction monitoring" (IS-MRM for glycerophosphocholines (PCs has been commonly applied in many bioanalytical methods. "Visualized MEs" is a suitable term to describe the application of IS-MRM to visualize the elution pattern of phospholipids. We selected a real case to discuss the relationship of MEs and phospholipids in different mobile phases by quantitative, qualitative, and visualized MEs in LC-MS/MS bioanalysis. The application of visualized MEs not only predicts the ion-suppression zone but also helps in selecting an appropriate (1 mobile phase, (2 column, (3 needle wash solvent for the residue of analyte and phospholipids, and (4 evaluates the clean-up efficiency of sample preparation. The TRAM-34 LC-MS/MS method, improved by using visualized MEs, was shown to be a precise and accurate analytical method. All data indicated that the use of visualized MEs indeed provided useful information about the LC-MS/MS method development and improvement. In this study, an integrative approach for the qualitative, quantitative, and visualized MEs was used to decipher the complexity of MEs.

  10. A dedicated circuit linking direction selective retinal ganglion cells to primary visual cortex

    OpenAIRE

    Cruz-Martín, Alberto; El-Danaf, Rana N.; Osakada, Fumitaka; Sriram, Balaji; Dhande, Onkar S.; Nguyen, Phong L.; Callaway, Edward M.; Ghosh, Anirvan; Huberman, Andrew D.

    2014-01-01

    How specific features in the environment are represented within the brain is an important unanswered question in neuroscience. A subset of retinal neurons, called direction selective ganglion cells (DSGCs) are specialized for detecting motion along specific axes of the visual field 1 . Despite extensive study of the retinal circuitry that endows DSGCs with their unique tuning properties 2,3 , their downstream circuitry in the brain and thus their contribution to visual processing has remained...

  11. Visualization of multivalent histone modification in a single cell reveals highly concerted epigenetic changes on differentiation of embryonic stem cells

    DEFF Research Database (Denmark)

    Hattori, Naoko; Niwa, Tohru; Kimura, Kana;

    2013-01-01

    Combinations of histone modifications have significant biological roles, such as maintenance of pluripotency and cancer development, but cannot be analyzed at the single cell level. Here, we visualized a combination of histone modifications by applying the in situ proximity ligation assay, which....... Bivalent modification was clearly visualized by iChmo in wild-type embryonic stem cells (ESCs) known to have it, whereas rarely in Suz12 knockout ESCs and mouse embryonic fibroblasts known to have little of it. iChmo was applied to analysis of epigenetic and phenotypic changes of heterogeneous cell...

  12. Aversive reinforcement improves visual discrimination learning in free-flying honeybees.

    Directory of Open Access Journals (Sweden)

    Aurore Avarguès-Weber

    Full Text Available BACKGROUND: Learning and perception of visual stimuli by free-flying honeybees has been shown to vary dramatically depending on the way insects are trained. Fine color discrimination is achieved when both a target and a distractor are present during training (differential conditioning, whilst if the same target is learnt in isolation (absolute conditioning, discrimination is coarse and limited to perceptually dissimilar alternatives. Another way to potentially enhance discrimination is to increase the penalty associated with the distractor. Here we studied whether coupling the distractor with a highly concentrated quinine solution improves color discrimination of both similar and dissimilar colors by free-flying honeybees. As we assumed that quinine acts as an aversive stimulus, we analyzed whether aversion, if any, is based on an aversive sensory input at the gustatory level or on a post-ingestional malaise following quinine feeding. METHODOLOGY/PRINCIPAL FINDINGS: We show that the presence of a highly concentrated quinine solution (60 mM acts as an aversive reinforcer promoting rejection of the target associated with it, and improving discrimination of perceptually similar stimuli but not of dissimilar stimuli. Free-flying bees did not use remote cues to detect the presence of quinine solution; the aversive effect exerted by this substance was mediated via a gustatory input, i.e. via a distasteful sensory experience, rather than via a post-ingestional malaise. CONCLUSION: The present study supports the hypothesis that aversion conditioning is important for understanding how and what animals perceive and learn. By using this form of conditioning coupled with appetitive conditioning in the framework of a differential conditioning procedure, it is possible to uncover discrimination capabilities that may remain otherwise unsuspected. We show, therefore, that visual discrimination is not an absolute phenomenon but can be modulated by experience.

  13. Improving the Efficiency and Ease of Healthcare Analysis Through Use of Data Visualization Dashboards.

    Science.gov (United States)

    Stadler, Jennifer G; Donlon, Kipp; Siewert, Jordan D; Franken, Tessa; Lewis, Nathaniel E

    2016-06-01

    The digitization of a patient's health record has profoundly impacted medicine and healthcare. The compilation and accessibility of medical history has provided clinicians an unprecedented, holistic account of a patient's conditions, procedures, medications, family history, and social situation. In addition to the bedside benefits, this level of information has opened the door for population-level monitoring and research, the results of which can be used to guide initiatives that are aimed at improving quality of care. Cerner Corporation partners with health systems to help guide population management and quality improvement projects. With such an enormous and diverse client base-varying in geography, size, organizational structure, and analytic needs-discerning meaning in the data and how they fit with that particular hospital's goals is a slow, difficult task that requires clinical, statistical, and technical literacy. This article describes the development of dashboards for efficient data visualization at the healthcare facility level. Focusing on two areas with broad clinical importance, sepsis patient outcomes and 30-day hospital readmissions, dashboards were developed with the goal of aggregating data and providing meaningful summary statistics, highlighting critical performance metrics, and providing easily digestible visuals that can be understood by a wide range of personnel with varying levels of skill and areas of expertise. These internal-use dashboards have allowed associates in multiple roles to perform a quick and thorough assessment on a hospital of interest by providing the data to answer necessary questions and to identify important trends or opportunities. This automation of a previously manual process has greatly increased efficiency, saving hours of work time per hospital analyzed. Additionally, the dashboards have standardized the analysis process, ensuring use of the same metrics and processes so that overall themes can be compared across

  14. Developmental improvements in the resolution and capacity of visual working memory share a common source.

    Science.gov (United States)

    Simmering, Vanessa R; Miller, Hilary E

    2016-08-01

    The nature of visual working memory (VWM) representations is currently a source of debate between characterizations as slot-like versus a flexibly-divided pool of resources. Recently, a dynamic neural field model has been proposed as an alternative account that focuses more on the processes by which VWM representations are formed, maintained, and used in service of behavior. This dynamic model has explained developmental increases in VWM capacity and resolution through strengthening excitatory and inhibitory connections. Simulations of developmental improvements in VWM resolution suggest that one important change is the accuracy of comparisons between items held in memory and new inputs. Thus, the ability to detect changes is a critical component of developmental improvements in VWM performance across tasks, leading to the prediction that capacity and resolution should correlate during childhood. Comparing 5- to 8-year-old children's performance across color discrimination and change detection tasks revealed the predicted correlation between estimates of VWM capacity and resolution, supporting the hypothesis that increasing connectivity underlies improvements in VWM during childhood. These results demonstrate the importance of formalizing the processes that support the use of VWM, rather than focusing solely on the nature of representations. We conclude by considering our results in the broader context of VWM development. PMID:27329264

  15. Possible improvement of solar cell efficiency

    International Nuclear Information System (INIS)

    We present the development of a new solar cell prototype in order to improve photovoltaic efficiency. In this model we show that the material can have three successive incident ray absorptions instead of two currently, by varying the incidence angle, the aperture between the summits of two neighbouring pyramids and their height. This study concerns in particular the photovoltaic parameters such as the spectral response. This model was checked for angles varying between 54 and 60 deg and for pyramid heights between 5 and 10 μm. For these values of incidence angle, the apertures between the summits of two neighbouring pyramids varied respectively from 14.54 to 11.54 μm for a pyramid angle height of 10 μm

  16. 3D-dynamic visualization of complex molecular cell biology processes : 1-year university students' understanding of visualizations of signal transduction

    OpenAIRE

    Jacobsson, Johan Lars Henrik

    2008-01-01

    This study deals with the use of 3D-dynamic visualizations for teaching complex molecular cell biology concepts. The focus is on signal transduction, which is a concept that constitutes an important part of biological systems. 3D-dynamic visualizations (animations) were produced and shown for a total of 24 students attending a course in molecular cell biology at Karlstad University, Sweden. Data were collected by questionnaires and interviews which were structured around the understandability...

  17. Improvement of fine motor skills in children with visual impairment: an explorative study

    NARCIS (Netherlands)

    Reimer, A.M.; Cox, R.F.; Nijhuis-Van der Sanden, M.W.G.; Boonstra, F.N.

    2011-01-01

    In this study we analysed the potential spin-off of magnifier training on the fine-motor skills of visually impaired children. The fine-motor skills of 4- and 5-year-old visually impaired children were assessed using the manual skills test for children (6-12 years) with a visual impairment (ManuVis)

  18. Improvement of Fine Motor Skills in Children with Visual Impairment: An Explorative Study

    Science.gov (United States)

    Reimer, A. M.; Cox, R. F. A.; Nijhuis-Van der Sanden, M. W. G.; Boonstra, F. N.

    2011-01-01

    In this study we analysed the potential spin-off of magnifier training on the fine-motor skills of visually impaired children. The fine-motor skills of 4- and 5-year-old visually impaired children were assessed using the manual skills test for children (6-12 years) with a visual impairment (ManuVis) and movement assessment for children (Movement…

  19. Improvement of fine motor skills in children with visual impairment: An explorative study

    NARCIS (Netherlands)

    Reimer, A.M.; Cox, R.F.A.; Nijhuis-Van der Sanden, M.W.G.; Boonstra, F.N.

    2011-01-01

    In this study we analysed the potential spin-off of magnifier training on the fine-motor skills of visually impaired children. The fine-motor skills of 4- and 5-year-old visually impaired children were assessed using the manual skills test for children (6-12 years) with a visual impairment (ManuVis)

  20. Long-Term Impact of Improving Visualization Abilities of Minority Engineering and Technology Students: Preliminary Results

    Science.gov (United States)

    Study, Nancy E.

    2011-01-01

    Previous studies found that students enrolled in introductory engineering graphics courses at a historically black university (HBCU) had significantly lower than average test scores on the Purdue Spatial Visualization Test: Visualization of Rotations (PSVT) when it was administered during the first week of class. Since the ability to visualize is…

  1. Generation of Rho Zero Cells: Visualization and Quantification of the mtDNA Depletion Process

    OpenAIRE

    Susanna Schubert; Sandra Heller; Birgit Löffler; Ingo Schäfer; Martina Seibel; Gaetano Villani; Peter Seibel

    2015-01-01

    Human mitochondrial DNA (mtDNA) is located in discrete DNA-protein complexes, so called nucleoids. These structures can be easily visualized in living cells by utilizing the fluorescent stain PicoGreen®. In contrary, cells devoid of endogenous mitochondrial genomes (ρ0 cells) display no mitochondrial staining in the cytoplasm. A modified restriction enzyme can be targeted to mitochondria to cleave the mtDNA molecules in more than two fragments, thereby activating endogenous nucleases. By a...

  2. cellPACK: A Virtual Mesoscope to Model and Visualize Structural Systems Biology

    OpenAIRE

    Johnson, Graham T; Autin, Ludovic; Al-Alusi, Mostafa; Goodsell, David S.; Sanner, Michel F.; Olson, Arthur J.

    2014-01-01

    cellPACK assembles computational models of the biological mesoscale, an intermediate scale (10−7–10−8m) between molecular and cellular biology. cellPACK’s modular architecture unites existing and novel packing algorithms to generate, visualize and analyze comprehensive 3D models of complex biological environments that integrate data from multiple experimental systems biology and structural biology sources. cellPACK is currently available as open source code, with tools for validation of model...

  3. Visualization of mRNA translation in living cells

    OpenAIRE

    RODRIGUEZ, ALEXIS J.; Shenoy, Shailesh M; Singer, Robert H.; Condeelis, John

    2006-01-01

    The role of mRNA localization is presumably to effect cell asymmetry by synthesizing proteins in specific cellular compartments. However, protein synthesis has never been directly demonstrated at the sites of mRNA localization. To address this, we developed a live cell method for imaging translation of β-actin mRNA. Constructs coding for β-actin, containing tetracysteine motifs, were transfected into C2C12 cells, and sites of nascent polypeptide chains were detected using the biarsenial dyes ...

  4. Common transcriptional mechanisms for visual photoreceptor cell differentiation among Pancrustaceans.

    Directory of Open Access Journals (Sweden)

    Simpla Mahato

    2014-07-01

    Full Text Available A hallmark of visual rhabdomeric photoreceptors is the expression of a rhabdomeric opsin and uniquely associated phototransduction molecules, which are incorporated into a specialized expanded apical membrane, the rhabdomere. Given the extensive utilization of rhabdomeric photoreceptors in the eyes of protostomes, here we address whether a common transcriptional mechanism exists for the differentiation of rhabdomeric photoreceptors. In Drosophila, the transcription factors Pph13 and Orthodenticle (Otd direct both aspects of differentiation: rhabdomeric opsin transcription and rhabdomere morphogenesis. We demonstrate that the orthologs of both proteins are expressed in the visual systems of the distantly related arthropod species Tribolium castaneum and Daphnia magna and that their functional roles are similar in these species. In particular, we establish that the Pph13 homologs have the ability to bind a subset of Rhodopsin core sequence I sites and that these sites are present in key phototransduction genes of both Tribolium and Daphnia. Furthermore, Pph13 and Otd orthologs are capable of executing deeply conserved functions of photoreceptor differentiation as evidenced by the ability to rescue their respective Drosophila mutant phenotypes. Pph13 homologs are equivalent in their ability to direct both rhabdomere morphogenesis and opsin expression within Drosophila, whereas Otd paralogs demonstrate differential abilities to regulate photoreceptor differentiation. Finally, loss-of-function analyses in Tribolium confirm the conserved requirement of Pph13 and Otd in regulating both rhabdomeric opsin transcription and rhabdomere morphogenesis. Taken together, our data identify components of a regulatory framework for rhabdomeric photoreceptor differentiation in Pancrustaceans, providing a foundation for defining ancestral regulatory modules of rhabdomeric photoreceptor differentiation.

  5. Improving Bayesian Reasoning: The Effects of Phrasing, Visualization, and Spatial Ability.

    Science.gov (United States)

    Ottley, Alvitta; Peck, Evan M; Harrison, Lane T; Afergan, Daniel; Ziemkiewicz, Caroline; Taylor, Holly A; Han, Paul K J; Chang, Remco

    2016-01-01

    Decades of research have repeatedly shown that people perform poorly at estimating and understanding conditional probabilities that are inherent in Bayesian reasoning problems. Yet in the medical domain, both physicians and patients make daily, life-critical judgments based on conditional probability. Although there have been a number of attempts to develop more effective ways to facilitate Bayesian reasoning, reports of these findings tend to be inconsistent and sometimes even contradictory. For instance, the reported accuracies for individuals being able to correctly estimate conditional probability range from 6% to 62%. In this work, we show that problem representation can significantly affect accuracies. By controlling the amount of information presented to the user, we demonstrate how text and visualization designs can increase overall accuracies to as high as 77%. Additionally, we found that for users with high spatial ability, our designs can further improve their accuracies to as high as 100%. By and large, our findings provide explanations for the inconsistent reports on accuracy in Bayesian reasoning tasks and show a significant improvement over existing methods. We believe that these findings can have immediate impact on risk communication in health-related fields. PMID:26390491

  6. A Model of Generating Visual Place Cells Based on Environment Perception and Similar Measure

    Science.gov (United States)

    2016-01-01

    It is an important content to generate visual place cells (VPCs) in the field of bioinspired navigation. By analyzing the firing characteristic of biological place cells and the existing methods for generating VPCs, a model of generating visual place cells based on environment perception and similar measure is abstracted in this paper. VPCs' generation process is divided into three phases, including environment perception, similar measure, and recruiting of a new place cell. According to this process, a specific method for generating VPCs is presented. External reference landmarks are obtained based on local invariant characteristics of image and a similar measure function is designed based on Euclidean distance and Gaussian function. Simulation validates the proposed method is available. The firing characteristic of the generated VPCs is similar to that of biological place cells, and VPCs' firing fields can be adjusted flexibly by changing the adjustment factor of firing field (AFFF) and firing rate's threshold (FRT). PMID:27597859

  7. A Model of Generating Visual Place Cells Based on Environment Perception and Similar Measure.

    Science.gov (United States)

    Zhou, Yang; Wu, Dewei

    2016-01-01

    It is an important content to generate visual place cells (VPCs) in the field of bioinspired navigation. By analyzing the firing characteristic of biological place cells and the existing methods for generating VPCs, a model of generating visual place cells based on environment perception and similar measure is abstracted in this paper. VPCs' generation process is divided into three phases, including environment perception, similar measure, and recruiting of a new place cell. According to this process, a specific method for generating VPCs is presented. External reference landmarks are obtained based on local invariant characteristics of image and a similar measure function is designed based on Euclidean distance and Gaussian function. Simulation validates the proposed method is available. The firing characteristic of the generated VPCs is similar to that of biological place cells, and VPCs' firing fields can be adjusted flexibly by changing the adjustment factor of firing field (AFFF) and firing rate's threshold (FRT). PMID:27597859

  8. A Hyaluronan-Based Injectable Hydrogel Improves the Survival and Integration of Stem Cell Progeny following Transplantation

    Directory of Open Access Journals (Sweden)

    Brian G. Ballios

    2015-06-01

    Full Text Available The utility of stem cells and their progeny in adult transplantation models has been limited by poor survival and integration. We designed an injectable and bioresorbable hydrogel blend of hyaluronan and methylcellulose (HAMC and tested it with two cell types in two animal models, thereby gaining an understanding of its general applicability for enhanced cell distribution, survival, integration, and functional repair relative to conventional cell delivery in saline. HAMC improves cell survival and integration of retinal stem cell (RSC-derived rods in the retina. The pro-survival mechanism of HAMC is ascribed to the interaction of the CD44 receptor with HA. Transient disruption of the retinal outer limiting membrane, combined with HAMC delivery, results in significantly improved rod survival and visual function. HAMC also improves the distribution, viability, and functional repair of neural stem and progenitor cells (NSCs. The HAMC delivery system improves cell transplantation efficacy in two CNS models, suggesting broad applicability.

  9. MR urography. Improved visualization of the urinary collecting system using a negative oral contrast agent

    International Nuclear Information System (INIS)

    To evaluate the image quality of the urinary tract using oral administration of a combination of both water and a negative gastrointestinal contrast agent, Bothdel. The study was divided into two parts: the phantom study and the healthy volunteers study. The imaging sequences used were the rapid acquisition with relaxation enhancement (RARE) and the half-Fourier acquisition single-shot turbo spin-echo (HASTE) techniques. Magnetic resonance Urography (MRU) was performed in 13 healthy volunteers using the RARE imaging sequences. After collection of the pre-contrast images, post-contrast MRU was obtained 30 min and 60 min after the oral administration of the contrast agent. Image assessment was based on the contrast effect, the image effect, and the opacification score. Statistical analysis was performed using the Wilcoxon signed-rank test. The signal intensity using 100%-12.5% Bothdel was no different to the background noise using the RARE sequence. At concentrations below 12.5%, there were statistically significant improvements in the contrast, the image effect, and the opacification score between pre- and post-contrast images. No significant difference was observed between the 30 min and 60 min post-contrast images. In contrast, the effect and pre-contrast images were graded as poor in seven cases, whereas no post-contrast images were graded as poor. There was a particularly significant improvement in the opacification score with the distal ureter being the most difficult segment to opacify. Oral administration of both water and Bothdel effectively removed the bowel signal and improved visualization of the urinary tract. (author)

  10. Visual documentation process of historic building refurbishment "Improving energy efficiency by insulating wall cavity"

    Science.gov (United States)

    Bennadji, A.

    2013-07-01

    The North East of Scotland's construction method is similar to most popular building typologies in the UK. This typology can vary in term of external material (Granite, brick or stone) but with a secondary, usually timber sub frame with a lining on its interior. Insulation was seldom a consideration when such buildings were completed. Statistics shows that 80% of existing buildings in the UK will need to be upgraded. The lack of knowledge in dealing with old building fabric's manipulation has a negative impact on buildings' integrity. The documentation of such process seems to be an important step that buildings' actors should undertake to communicate a practical knowledge that is still at incubation stage. We wanted for this documentation to be visual, as descriptions might mislead none specialised and specialised in the field due to the innovative approach our method was conducted with. For the Scottish context this research/experiment will concentrate on existing granite wall buildings with plastered lath internal wall. It is unfortunate to see the commonly beautiful interiors of Scottish buildings disappearing, when the internal linings are removed. Skips are filled with old Plaster and Lath and new linings have to be supplied and fitted. Excessive waste is created in this change. This paper is based on a historic building energy improvement case study financed by the European commission and the Scottish Government. The pilot study consists of insulating an 18th century house using an innovative product and method. The project was a response to a call by the CIC start (Construction Innovation Club), aiming to establish a link between SMEs and the Universities. The project saw the day in collaboration with Icynene Canada, KDL Kishorn (see full list in the acknowledgment). This paper describes the process through which the team went through to improve the building envelope without damaging the buildings original features (Loveday et all). The energy efficiency

  11. Concurrent visuomotor behaviour improves form discrimination in a patient with visual form agnosia.

    OpenAIRE

    Schenk, T.; Milner, A D

    2006-01-01

    It is now well established that the visual brain is divided into two visual streams, the ventral and the dorsal stream. Milner and Goodale have suggested that the ventral stream is dedicated for processing vision for perception and the dorsal stream vision for action [A.D. Milner & M.A. Goodale (1995) The Visual Brain in Action, Oxford University Press, Oxford]. However, it is possible that ongoing processes in the visuomotor stream will nevertheless have an effect on perceptual processes. Th...

  12. Performance improvement of silicon solar cells by nanoporous silicon coating

    Directory of Open Access Journals (Sweden)

    Dzhafarov T. D.

    2012-04-01

    Full Text Available In the present paper the method is shown to improve the photovoltaic parameters of screen-printed silicon solar cells by nanoporous silicon film formation on the frontal surface of the cell using the electrochemical etching. The possible mechanisms responsible for observed improvement of silicon solar cell performance are discussed.

  13. THE IMPROVEMENT OF AUDIO-VISUAL BASED DANCE APPRECIATION LEARNING AMONG PRIMARY TEACHER EDUCATION STUDENTS OF MAKASSAR STATE UNIVERSITY

    Directory of Open Access Journals (Sweden)

    Wahira

    2014-06-01

    Full Text Available This research aimed to improve the skill in appreciating dances owned by the students of Primary Teacher Education of Makassar State University, to improve the perception towards audio-visual based art appreciation, to increase the students’ interest in audio-visual based art education subject, and to increase the students’ responses to the subject. This research was classroom action research using the research design created by Kemmis & MC. Taggart, which was conducted to 42 students of Primary Teacher Education of Makassar State University. The data collection was conducted using observation, questionnaire, and interview. The techniques of data analysis applied in this research were descriptive qualitative and quantitative. The results of this research were: (1 the students’ achievement in audio-visual based dance appreciation improved: precycle 33,33%, cycle I 42,85% and cycle II 83,33%, (2 the students’ perception towards the audio-visual based dance appreciation improved: cycle I 59,52%, and cycle II 71,42%. The students’ perception towards the subject obtained through structured interview in cycle I and II was 69,83% in a high category, (3 the interest of the students in the art education subject, especially audio-visual based dance appreciation, increased: cycle I 52,38% and cycle II 64,28%, and the students’ interest in the subject obtained through structured interview was 69,50 % in a high category. (3 the students’ response to audio-visual based dance appreciation increased: cycle I 54,76% and cycle II 69,04% in a good category.

  14. Xenopus laevis retinal ganglion cell dendritic arbors develop independently of visual stimulation

    Directory of Open Access Journals (Sweden)

    Rebecca L. Rigel

    2004-06-01

    Full Text Available Newly formed neurons must locate their appropriate target cells and then form synaptic connections with these targets in order to establish a functional nervous system. In the vertebrate retina, retinal ganglion cell (RGC dendrites extend from the cell body and form synapses with nearby amacrine and bipolar cells. RGC axons, however, exit the retina and synapse with the dendrites of midbrain neurons in the optic tectum. We examined how visual stimulation influenced Xenopus RGC dendritic arborization. Neuronal activity is known to be an important factor in shaping dendritic and axonal arborization. Thus, we reared tadpoles in dark and light environments then used rhodamine dextran retrograde labeling to identify RGCs in the retina. When we compared RGC dendritic arbors from tadpoles reared in dark and light environments, we found no morphological differences, suggesting that physiological visual activity did not contribute to the morphological development of Xenopus RGC dendritic arbors.

  15. Xenopus laevis Retinal Ganglion Cell Dendritic Arbors Develop Independently of Visual Stimulation

    Directory of Open Access Journals (Sweden)

    Barbara Lom

    2004-01-01

    Full Text Available Newly formed neurons must locate their appropriate target cells and then form synaptic connections with these targets in order to establish a functional nervous system. In the vertebrate retina, retinal ganglion cell (RGC dendrites extend from the cell body and form synapses with nearby amacrine and bipolar cells. RGC axons, however, exit the retina and synapse with the dendrites of midbrain neurons in the optic tectum. We examined how visual stimulation influenced Xenopus RGC dendritic arborization. Neuronal activity is known to be an important factor in shaping dendritic and axonal arborization. Thus, we reared tadpoles in dark and light environments then used rhodamine dextran retrograde labeling to identify RGCs in the retina. When we compared RGC dendritic arbors from tadpoles reared in dark and light environments, we found no morphological differences, suggesting that physiological visual activity did not contribute to the morphological development of Xenopus RGC dendritic arbors.

  16. Improved visual performance in letter perception through edge orientation encoding in a retinal prosthesis simulation

    Science.gov (United States)

    Isabell Kiral-Kornek, F.; OʼSullivan-Greene, Elma; Savage, Craig O.; McCarthy, Chris; Grayden, David B.; Burkitt, Anthony N.

    2014-12-01

    Objective. Stimulation strategies for retinal prostheses predominately seek to directly encode image brightness values rather than edge orientations. Recent work suggests that the generation of oriented elliptical phosphenes may be possible by controlling interactions between neighboring electrodes. Based on this, we propose a novel stimulation strategy for prosthetic vision that extracts edge orientation information from the intensity image and encodes it as oriented elliptical phosphenes. We test the hypothesis that encoding edge orientation via oriented elliptical phosphenes leads to better alphabetic letter recognition than standard intensity-based encoding. Approach. We conduct a psychophysical study with simulated phosphene vision with 12 normal-sighted volunteers. The two stimulation strategies were compared with variations of letter size, electrode drop-out and spatial offsets of phosphenes. Main results. Mean letter recognition accuracy was significantly better with the new proposed stimulation strategy (65%) compared to direct grayscale encoding (47%). All examined parameters—stimulus size, phosphene dropout, and location shift—were found to influence the performance, with significant two-way interactions between phosphene dropout and stimulus size as well as between phosphene dropout and phosphene location shift. The analysis delivers a model of perception performance. Significance. Displaying available directional information to an implant user may improve their visual performance. We present a model for designing a stimulation strategy under the constraints of existing retinal prostheses that can be exploited by retinal implant developers to strategically employ oriented phosphenes.

  17. IMPACT OF VISUAL AIDS IN IMPROVING WRITING SKILLS OF ESL LEARNERS

    Directory of Open Access Journals (Sweden)

    Kaushik Trivedi

    2015-06-01

    Full Text Available English language is the most effective language of the world which connects two nations, two cultural and two human beings of the world. Moreover it is important to note that knowing English generate opportunity for one in building career in this global world which is full of challenges as well as opportunities. Among all other communication skills in English, Writing Skills plays a vital role in professional field. But it has been noticed in rural areas of India both at the school and college level, where the medium of instruction is mother tongue, the basic standard of learners general in English and specific in English Writing is not up to the mark. With a view to this fact, the research paper discusses a study on impact of visual aids in improving writing skills of ESL learners at primary level. The research paper discusses about the review of related literature, needs, problems, hypothesis, limitations, research procedure, methodology, findings, scope and implications of the research.

  18. Using digital photo technology to improve visualization of gastric lumen CT images

    International Nuclear Information System (INIS)

    In order to evaluate the gastric lumen CT images better, a new method is being applied to images using an Image Processing software. During a 12-month period, 69 patients with various gastric symptoms and 20 normal (as far as it concerns the upper gastrointestinal system) volunteers underwent computed tomography of the upper gastrointestinal system. Just before the examination the patients and the normal volunteers underwent preparation with 40 ml soda water and 10 ml gastrografin. All the CT images were digitized with an Olympus 3.2 Mpixel digital camera and further processed with an Image Processing software. The administration per os of gastrografin and soda water resulted in the distension of the stomach and consequently better visualization of all the anatomic parts. By using an Image Processing software in a PC, all the pathological and normal images of the stomach were better diagnostically estimated. We believe that the photo digital technology improves the diagnostic capacity not only of the CT image but also in MRI and probably many other imaging methods

  19. Improved Neural Signal Classification in a Rapid Serial Visual Presentation Task Using Active Learning.

    Science.gov (United States)

    Marathe, Amar R; Lawhern, Vernon J; Wu, Dongrui; Slayback, David; Lance, Brent J

    2016-03-01

    The application space for brain-computer interface (BCI) technologies is rapidly expanding with improvements in technology. However, most real-time BCIs require extensive individualized calibration prior to use, and systems often have to be recalibrated to account for changes in the neural signals due to a variety of factors including changes in human state, the surrounding environment, and task conditions. Novel approaches to reduce calibration time or effort will dramatically improve the usability of BCI systems. Active Learning (AL) is an iterative semi-supervised learning technique for learning in situations in which data may be abundant, but labels for the data are difficult or expensive to obtain. In this paper, we apply AL to a simulated BCI system for target identification using data from a rapid serial visual presentation (RSVP) paradigm to minimize the amount of training samples needed to initially calibrate a neural classifier. Our results show AL can produce similar overall classification accuracy with significantly less labeled data (in some cases less than 20%) when compared to alternative calibration approaches. In fact, AL classification performance matches performance of 10-fold cross-validation (CV) in over 70% of subjects when training with less than 50% of the data. To our knowledge, this is the first work to demonstrate the use of AL for offline electroencephalography (EEG) calibration in a simulated BCI paradigm. While AL itself is not often amenable for use in real-time systems, this work opens the door to alternative AL-like systems that are more amenable for BCI applications and thus enables future efforts for developing highly adaptive BCI systems. PMID:26600162

  20. Drivers' Visual Behavior When Using Hand-Held and Hands-Free Cell Phones

    OpenAIRE

    Fitch, Gregory M.; Guo, Feng; Hanowski, Richard J.; Perez, M. P.

    2014-01-01

    This study investigated driver distraction and how the use of handheld (HH), portable hands-free (PHF), and integrated hands-free (IHF) cell phones affected the visual behavior of motor vehicle drivers. Method A naturalistic driving study recorded 204 participating drivers using video cameras and vehicle sensors for an average of 31 days. A total of 1564 cell phone calls made and 844 text messages sent while driving were sampled and underwent a video review. Baselines were established by reco...

  1. Teneurin-3 Specifies Morphological and Functional Connectivity of Retinal Ganglion Cells in the Vertebrate Visual System

    OpenAIRE

    Paride Antinucci; Nikolas Nikolaou; Martin P. Meyer; Robert Hindges

    2013-01-01

    Summary A striking feature of the CNS is the precise wiring of its neuronal connections. During vertebrate visual system development, different subtypes of retinal ganglion cells (RGCs) form specific connections with their corresponding synaptic partners. However, the underlying molecular mechanisms remain to be fully elucidated. Here, we report that the cell-adhesive transmembrane protein Teneurin-3 (Tenm3) is required by zebrafish RGCs for acquisition of their correct morphological and func...

  2. Both visual and idiothetic cues contribute to head direction cell stability during navigation along complex routes

    OpenAIRE

    Yoder, Ryan M.; Clark, Benjamin J.; Brown, Joel E.; Lamia, Mignon V.; Valerio, Stephane; Shinder, Michael E.; Taube, Jeffrey S.

    2011-01-01

    Successful navigation requires a constantly updated neural representation of directional heading, which is conveyed by head direction (HD) cells. The HD signal is predominantly controlled by visual landmarks, but when familiar landmarks are unavailable, self-motion cues are able to control the HD signal via path integration. Previous studies of the relationship between HD cell activity and path integration have been limited to two or more arenas located in the same room, a drawback for interp...

  3. NaviCell Web Service for network-based data visualization.

    Science.gov (United States)

    Bonnet, Eric; Viara, Eric; Kuperstein, Inna; Calzone, Laurence; Cohen, David P A; Barillot, Emmanuel; Zinovyev, Andrei

    2015-07-01

    Data visualization is an essential element of biological research, required for obtaining insights and formulating new hypotheses on mechanisms of health and disease. NaviCell Web Service is a tool for network-based visualization of 'omics' data which implements several data visual representation methods and utilities for combining them together. NaviCell Web Service uses Google Maps and semantic zooming to browse large biological network maps, represented in various formats, together with different types of the molecular data mapped on top of them. For achieving this, the tool provides standard heatmaps, barplots and glyphs as well as the novel map staining technique for grasping large-scale trends in numerical values (such as whole transcriptome) projected onto a pathway map. The web service provides a server mode, which allows automating visualization tasks and retrieving data from maps via RESTful (standard HTTP) calls. Bindings to different programming languages are provided (Python and R). We illustrate the purpose of the tool with several case studies using pathway maps created by different research groups, in which data visualization provides new insights into molecular mechanisms involved in systemic diseases such as cancer and neurodegenerative diseases. PMID:25958393

  4. Can Dynamic Visualizations Improve Middle School Students' Understanding of Energy in Photosynthesis?

    Science.gov (United States)

    Ryoo, Kihyun; Linn, Marcia C.

    2012-01-01

    Dynamic visualizations have the potential to make abstract scientific phenomena more accessible and visible to students, but they can also be confusing and difficult to comprehend. This research investigates how dynamic visualizations, compared to static illustrations, can support middle school students in developing an integrated understanding of…

  5. A dedicated circuit links direction-selective retinal ganglion cells to the primary visual cortex

    Science.gov (United States)

    Cruz-Martín, Alberto; El-Danaf, Rana N.; Osakada, Fumitaka; Sriram, Balaji; Dhande, Onkar S.; Nguyen, Phong L.; Callaway, Edward M.; Ghosh, Anirvan; Huberman, Andrew D.

    2014-03-01

    How specific features in the environment are represented within the brain is an important unanswered question in neuroscience. A subset of retinal neurons, called direction-selective ganglion cells (DSGCs), are specialized for detecting motion along specific axes of the visual field. Despite extensive study of the retinal circuitry that endows DSGCs with their unique tuning properties, their downstream circuitry in the brain and thus their contribution to visual processing has remained unclear. In mice, several different types of DSGCs connect to the dorsal lateral geniculate nucleus (dLGN), the visual thalamic structure that harbours cortical relay neurons. Whether direction-selective information computed at the level of the retina is routed to cortical circuits and integrated with other visual channels, however, is unknown. Here we show that there is a di-synaptic circuit linking DSGCs with the superficial layers of the primary visual cortex (V1) by using viral trans-synaptic circuit mapping and functional imaging of visually driven calcium signals in thalamocortical axons. This circuit pools information from several types of DSGCs, converges in a specialized subdivision of the dLGN, and delivers direction-tuned and orientation-tuned signals to superficial V1. Notably, this circuit is anatomically segregated from the retino-geniculo-cortical pathway carrying non-direction-tuned visual information to deeper layers of V1, such as layer 4. Thus, the mouse harbours several functionally specialized, parallel retino-geniculo-cortical pathways, one of which originates with retinal DSGCs and delivers direction- and orientation-tuned information specifically to the superficial layers of the primary visual cortex. These data provide evidence that direction and orientation selectivity of some V1 neurons may be influenced by the activation of DSGCs.

  6. Effects of deuterium oxide and galvanic vestibular stimulation on visual cortical cell function

    International Nuclear Information System (INIS)

    The spontaneous and evoked unit activities of complex visual cortical cells were recorded from Brodmann's area 18 in immobilized, unanesthetized cats before, during, and after stimulation of the vestibular system. The vestibular system was stimulated by intravenous injection of deuterium oxide (D2O)--a noted nystagmogenic agent--or by direct galvanic stimulation of the labyrinth. Measures of the receptive-field areas, poststimulus time histograms, directional preferences, and the optimal speed of the light bar stimulating the cell were obtained before and after the application of D2O. Directional preferences were determined in a novel manner, using a method derived from a hierarchical clustering technique. Data were collected and analyzed from a) visual cortical cells in cats with intact labyrinths, b) visual cortical cells in cats following bilateral labrinthectomies, and c) nonvisual cortical cells in cats with intact labyrinths. The other cellular characteristics were also altered by the D2O. Galvanic stimulation of the labyrinth resembles, in its effects, the injection of D2O. In labyrinth-intact cats, the time course of area 18 spontaneous activity dramatically increased 30 min or more after D2O was administered. It peaked 2-3 h later and still had not returned to preinjection levels even 7 h after the D2O administration. In bilaterally labyrinthectomized cats, the spontaneous activity of the visual cells did not change following D2O administration. In nonvisual cells from labyrinth-intact cats, the spontaneous activity demonstrated a slight but significant decrease over time after D2O injection. In pilot studies, the cats were injected with D2O. Within 8-10 min afterward, signs of positional nystagmus commenced; and within 30 min, problems in maintaining balance were noted. This continued for 7-8 h before disappearing. In the labyrinthectomized animals, such effects were not observed

  7. Effects of deuterium oxide and galvanic vestibular stimulation on visual cortical cell function

    Energy Technology Data Exchange (ETDEWEB)

    Reinis, S.; Landolt, J.P.; Weiss, D.S.; Money, K.E.

    1984-03-01

    The spontaneous and evoked unit activities of complex visual cortical cells were recorded from Brodmann's area 18 in immobilized, unanesthetized cats before, during, and after stimulation of the vestibular system. The vestibular system was stimulated by intravenous injection of deuterium oxide (D2O)--a noted nystagmogenic agent--or by direct galvanic stimulation of the labyrinth. Measures of the receptive-field areas, poststimulus time histograms, directional preferences, and the optimal speed of the light bar stimulating the cell were obtained before and after the application of D2O. Directional preferences were determined in a novel manner, using a method derived from a hierarchical clustering technique. Data were collected and analyzed from a) visual cortical cells in cats with intact labyrinths, b) visual cortical cells in cats following bilateral labrinthectomies, and c) nonvisual cortical cells in cats with intact labyrinths. The other cellular characteristics were also altered by the D2O. Galvanic stimulation of the labyrinth resembles, in its effects, the injection of D2O. In labyrinth-intact cats, the time course of area 18 spontaneous activity dramatically increased 30 min or more after D2O was administered. It peaked 2-3 h later and still had not returned to preinjection levels even 7 h after the D2O administration. In bilaterally labyrinthectomized cats, the spontaneous activity of the visual cells did not change following D2O administration. In nonvisual cells from labyrinth-intact cats, the spontaneous activity demonstrated a slight but significant decrease over time after D2O injection. In pilot studies, the cats were injected with D2O. Within 8-10 min afterward, signs of positional nystagmus commenced; and within 30 min, problems in maintaining balance were noted. This continued for 7-8 h before disappearing. In the labyrinthectomized animals, such effects were not observed.

  8. Functionalized Graphitic Supports for Improved Fuel Cell Catalyst Stability Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Physical Sciences Inc. (PSI) together with the University of Connecticut (UCONN) proposes to demonstrate the improved fuel cell catalyst support durability offered...

  9. Optimized labeling of bone marrow mesenchymal cells with superparamagnetic iron oxide nanoparticles and in vivo visualization by magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Spray David C

    2011-02-01

    Full Text Available Abstract Background Stem cell therapy has emerged as a promising addition to traditional treatments for a number of diseases. However, harnessing the therapeutic potential of stem cells requires an understanding of their fate in vivo. Non-invasive cell tracking can provide knowledge about mechanisms responsible for functional improvement of host tissue. Superparamagnetic iron oxide nanoparticles (SPIONs have been used to label and visualize various cell types with magnetic resonance imaging (MRI. In this study we performed experiments designed to investigate the biological properties, including proliferation, viability and differentiation capacity of mesenchymal cells (MSCs labeled with clinically approved SPIONs. Results Rat and mouse MSCs were isolated, cultured, and incubated with dextran-covered SPIONs (ferumoxide alone or with poly-L-lysine (PLL or protamine chlorhydrate for 4 or 24 hrs. Labeling efficiency was evaluated by dextran immunocytochemistry and MRI. Cell proliferation and viability were evaluated in vitro with Ki67 immunocytochemistry and live/dead assays. Ferumoxide-labeled MSCs could be induced to differentiate to adipocytes, osteocytes and chondrocytes. We analyzed ferumoxide retention in MSCs with or without mitomycin C pretreatment. Approximately 95% MSCs were labeled when incubated with ferumoxide for 4 or 24 hrs in the presence of PLL or protamine, whereas labeling of MSCs incubated with ferumoxide alone was poor. Proliferative capacity was maintained in MSCs incubated with ferumoxide and PLL for 4 hrs, however, after 24 hrs it was reduced. MSCs incubated with ferumoxide and protamine were efficiently visualized by MRI; they maintained proliferation and viability for up to 7 days and remained competent to differentiate. After 21 days MSCs pretreated with mitomycin C still showed a large number of ferumoxide-labeled cells. Conclusions The efficient and long lasting uptake and retention of SPIONs by MSCs using a protocol

  10. An improved hydrothermal diamond anvil cell

    Science.gov (United States)

    Li, Jiankang; Bassett, W. A.; Chou, I.-Ming; Ding, Xin; Li, Shenghu; Wang, Xinyan

    2016-05-01

    A new type of HDAC-V hydrothermal diamond anvil cell (HDAC-VT) has been designed to meet the demands of X-ray research including X-Ray Fluorescence, X-ray Absorption Spectroscopy, and small angle X-ray scattering. The earlier version of HDAC-V that offered a large rectangular solid angle used two posts and two driver screws on both sides of a rectangular body. The new version HDAC-VT in a triangular shape has two alternative guide systems, either three posts inserted into bushings suitable for small anvil faces or linear ball bearings suitable for large anvil faces. The HDAC-VT having three driver screws offers the advantage of greater control and stability even though it sacrifices some of the size of solid angle. The greater control allows better sealing of samples, while greater stability results in longer survival for anvils and ceramic parts. This improved design retains several beneficial features of the original HDAC-V as well. These include the small collar that surrounds the heater and sample chamber forming an Ar + H2 gas chamber to protect diamonds and their heating parts from being oxidized. Three linear ball bearings, when used, fit to the three posts prevent seizing that can result from deterioration of lubricant at high temperatures. Positioning the posts and bearings outside of the gas chamber as in HDAC-V also prevents seizing and possible deformation due to overheating. In order to control the heating rate precisely with computer software, we use Linkam T95 and have replaced the Linkam 1400XY heating stage with the HDAC-VT allowing the HDAC to be heated to 950 °C at a rate from 0.01 °C/min to 50 °C/min. We have used the HDAC-VT and Linkam T95 to observe in situ nucleation and growth of zabuyelite in aqueous fluid and to homogenize melt inclusions in quartz from three porphyry deposits in Shanxi, China.

  11. Visualization and cellular hierarchy inference of single-cell data using SPADE.

    Science.gov (United States)

    Anchang, Benedict; Hart, Tom D P; Bendall, Sean C; Qiu, Peng; Bjornson, Zach; Linderman, Michael; Nolan, Garry P; Plevritis, Sylvia K

    2016-07-01

    High-throughput single-cell technologies provide an unprecedented view into cellular heterogeneity, yet they pose new challenges in data analysis and interpretation. In this protocol, we describe the use of Spanning-tree Progression Analysis of Density-normalized Events (SPADE), a density-based algorithm for visualizing single-cell data and enabling cellular hierarchy inference among subpopulations of similar cells. It was initially developed for flow and mass cytometry single-cell data. We describe SPADE's implementation and application using an open-source R package that runs on Mac OS X, Linux and Windows systems. A typical SPADE analysis on a 2.27-GHz processor laptop takes ∼5 min. We demonstrate the applicability of SPADE to single-cell RNA-seq data. We compare SPADE with recently developed single-cell visualization approaches based on the t-distribution stochastic neighborhood embedding (t-SNE) algorithm. We contrast the implementation and outputs of these methods for normal and malignant hematopoietic cells analyzed by mass cytometry and provide recommendations for appropriate use. Finally, we provide an integrative strategy that combines the strengths of t-SNE and SPADE to infer cellular hierarchy from high-dimensional single-cell data. PMID:27310265

  12. Hydrologic-Process-Based Soil Texture Classifications for Improved Visualization of Landscape Function.

    Directory of Open Access Journals (Sweden)

    Derek G Groenendyk

    Full Text Available Soils lie at the interface between the atmosphere and the subsurface and are a key component that control ecosystem services, food production, and many other processes at the Earth's surface. There is a long-established convention for identifying and mapping soils by texture. These readily available, georeferenced soil maps and databases are used widely in environmental sciences. Here, we show that these traditional soil classifications can be inappropriate, contributing to bias and uncertainty in applications from slope stability to water resource management. We suggest a new approach to soil classification, with a detailed example from the science of hydrology. Hydrologic simulations based on common meteorological conditions were performed using HYDRUS-1D, spanning textures identified by the United States Department of Agriculture soil texture triangle. We consider these common conditions to be: drainage from saturation, infiltration onto a drained soil, and combined infiltration and drainage events. Using a k-means clustering algorithm, we created soil classifications based on the modeled hydrologic responses of these soils. The hydrologic-process-based classifications were compared to those based on soil texture and a single hydraulic property, Ks. Differences in classifications based on hydrologic response versus soil texture demonstrate that traditional soil texture classification is a poor predictor of hydrologic response. We then developed a QGIS plugin to construct soil maps combining a classification with georeferenced soil data from the Natural Resource Conservation Service. The spatial patterns of hydrologic response were more immediately informative, much simpler, and less ambiguous, for use in applications ranging from trafficability to irrigation management to flood control. The ease with which hydrologic-process-based classifications can be made, along with the improved quantitative predictions of soil responses and visualization

  13. Hydrologic-Process-Based Soil Texture Classifications for Improved Visualization of Landscape Function.

    Science.gov (United States)

    Groenendyk, Derek G; Ferré, Ty P A; Thorp, Kelly R; Rice, Amy K

    2015-01-01

    Soils lie at the interface between the atmosphere and the subsurface and are a key component that control ecosystem services, food production, and many other processes at the Earth's surface. There is a long-established convention for identifying and mapping soils by texture. These readily available, georeferenced soil maps and databases are used widely in environmental sciences. Here, we show that these traditional soil classifications can be inappropriate, contributing to bias and uncertainty in applications from slope stability to water resource management. We suggest a new approach to soil classification, with a detailed example from the science of hydrology. Hydrologic simulations based on common meteorological conditions were performed using HYDRUS-1D, spanning textures identified by the United States Department of Agriculture soil texture triangle. We consider these common conditions to be: drainage from saturation, infiltration onto a drained soil, and combined infiltration and drainage events. Using a k-means clustering algorithm, we created soil classifications based on the modeled hydrologic responses of these soils. The hydrologic-process-based classifications were compared to those based on soil texture and a single hydraulic property, Ks. Differences in classifications based on hydrologic response versus soil texture demonstrate that traditional soil texture classification is a poor predictor of hydrologic response. We then developed a QGIS plugin to construct soil maps combining a classification with georeferenced soil data from the Natural Resource Conservation Service. The spatial patterns of hydrologic response were more immediately informative, much simpler, and less ambiguous, for use in applications ranging from trafficability to irrigation management to flood control. The ease with which hydrologic-process-based classifications can be made, along with the improved quantitative predictions of soil responses and visualization of landscape

  14. No age deficits in the ability to use attention to improve visual working memory.

    Science.gov (United States)

    Souza, Alessandra S

    2016-08-01

    Maintenance of information in mind to the moment-to-moment cognition is accomplished by working memory (WM). WM capacity is reduced in old age, but the nature of this decline is yet not clear. The current study examined the hypothesis that the decline in visual WM performance with age is related to a reduced ability to use attention to control the contents of WM. Young (M = 26 years) and old (M = 71 years) adults performed a color reproduction task in which the precise color of a set of dots had to be maintained in mind over a brief interval and later reproduced using a continuous color wheel. Attention was manipulated by presenting a spatial cue before the onset of the memory array (a precue) or during the maintenance phase (retro-cue). The cue indicated with 100% certainty the item to be tested at the end of the trial. A precue allows the selective encoding of only the relevant item to WM, whereas a retro-cue allows WM contents to be updated by refreshing the relevant (cued) item and removing nonrelevant (noncued) items. Aging was associated with a lower capacity in the baseline (no-cue) condition. Precues and (to a smaller extent) retro-cues improved WM performance (in terms of probability of recall and memory precision). Critically, the benefits of cueing were of similar magnitude in young and older adults showing that the ability to use attention to selectively encode and update the contents of WM is preserved with aging. (PsycINFO Database Record PMID:27253868

  15. High-definition optical coherence tomography enables visualization of individual cells in healthy skin

    DEFF Research Database (Denmark)

    Boone, Marc; Jemec, Gregor B E; Del Marmol, Véronique

    2012-01-01

    HD-OCT could be confirmed by the phantom analysis. The identification of cells in the epidermis can be made by both techniques. RCM offers the best lateral resolution, and HD-OCT has the best penetration depth, providing images of individual cells deeper within the dermis. Eccrine ducts and hair...... shafts with pilosebaceous units can be observed depending on skin site. HD-OCT provides morphological imaging with sufficient resolution and penetration depth to permit visualization of individual cells at up to 570 μm in depth offering the possibility of additional structural information complementary...

  16. Visualization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Evaluates and improves the operational effectiveness of existing and emerging electronic warfare systems. By analyzing and visualizing simulation results...

  17. Simultaneous modeling of visual saliency and value computation improves predictions of economic choice

    OpenAIRE

    Towal, R. Blythe; Mormann, Milica; Koch, Christof

    2013-01-01

    Many decisions we make require visually identifying and evaluating numerous alternatives quickly. These usually vary in reward, or value, and in low-level visual properties, such as saliency. Both saliency and value influence the final decision. In particular, saliency affects fixation locations and durations, which are predictive of choices. However, it is unknown how saliency propagates to the final decision. Moreover, the relative influence of saliency and value is unclear. Here we address...

  18. Expert-Aware Approach: An Innovative Approach To Improve Network Data Visualization

    OpenAIRE

    Doris Hooi-Ten Wong; Kok-Soon Chai; Sureswaran Ramadass; Nicolas Vavasseur

    2010-01-01

    Computers have been infected by the computer anomalies. The availability of network data visualization tools greatly facilitate to perceive computer users from being affected by these anomalies. Many of the network data visualization tools are designed particularly for users with advanced network knowledge even though the tools are indispensable by diverse computer users. We proposed an expert-aware approach to designing a system which formulated with a large amount of network data and adapti...

  19. Multispectral fingerprinting for improved in vivo cell dynamics analysis

    Directory of Open Access Journals (Sweden)

    Cooper Cameron HJ

    2010-09-01

    Full Text Available Abstract Background Tracing cell dynamics in the embryo becomes tremendously difficult when cell trajectories cross in space and time and tissue density obscure individual cell borders. Here, we used the chick neural crest (NC as a model to test multicolor cell labeling and multispectral confocal imaging strategies to overcome these roadblocks. Results We found that multicolor nuclear cell labeling and multispectral imaging led to improved resolution of in vivo NC cell identification by providing a unique spectral identity for each cell. NC cell spectral identity allowed for more accurate cell tracking and was consistent during short term time-lapse imaging sessions. Computer model simulations predicted significantly better object counting for increasing cell densities in 3-color compared to 1-color nuclear cell labeling. To better resolve cell contacts, we show that a combination of 2-color membrane and 1-color nuclear cell labeling dramatically improved the semi-automated analysis of NC cell interactions, yet preserved the ability to track cell movements. We also found channel versus lambda scanning of multicolor labeled embryos significantly reduced the time and effort of image acquisition and analysis of large 3D volume data sets. Conclusions Our results reveal that multicolor cell labeling and multispectral imaging provide a cellular fingerprint that may uniquely determine a cell's position within the embryo. Together, these methods offer a spectral toolbox to resolve in vivo cell dynamics in unprecedented detail.

  20. A simple tool to improve pluripotent stem cell differentiation

    OpenAIRE

    Chetty, Sundari; Pagliuca, Felicia Walton; Honore, Christian; Kweudjeu, Anastasie; Rezania, Alireza; Melton, Douglas A.

    2013-01-01

    We develop a method to overcome previously documented restrictions on the differentiation propensities of pluripotent stem cells. Culturing pluripotent stem cells in dimethylsulfoxide (DMSO) activates the retinoblastoma protein, increases the proportion of cells in the early G1 phase of the cell cycle, and subsequently improves their competency for directed differentiation into multiple lineages in more than 25 stem cell lines. DMSO treatment also promotes terminal differentiation into functi...

  1. Didymium compound improves nickel-cadmium cell

    Science.gov (United States)

    1965-01-01

    Nickel electrodes impregnated with an additive solution of didymium hydrate and nitric acid mixed with nickel nitrate increases ampere-hour capacity of cells and does not affect the voltage characteristics.

  2. Training regimen involving cyclic induction of pupil constriction during far accommodation improves visual acuity in myopic children

    Directory of Open Access Journals (Sweden)

    Kenji Yuda

    2010-04-01

    Full Text Available Kenji Yuda1, Hiroshi Uozato2, Naoto Hara3, Wolfram Tetzlaff4, Satoru Hisahara5, Hiroko Horie6, Satomi Nakajima6, Hidenori Horie6,71Kikuna Yuda Eye Clinic, Yokohama, Japan; 2Department of Ophthalmology and Visual Science, Kitasato  University, Kanagawa, Japan; 3Department of Ophthalmology, Yokohama Dental and Medical Clinic, Kanagawa Dental College, Yokohama, Japan; 4ICORD, International Collaboration on Repair Discoveries, Univ. of British Columbia, Vancouver, BC, Canada; 5Panasonic Shikoku Electronics Co., Ltd., Yokohama, Japan; 6TechnoMaster Co., Ltd., Yokohama, Japan; 7Research Center of Brain and Oral Science, Kanagawa Dental College, Yokosuka, JapanPurpose: Myopia in school-age children has become increasingly prevalent in industrialized countries, especially in Asia. A large population of school-age children still suffers from low visual acuity. We have developed a novel, safe and noninvasive training method to activate a pupillary constriction response during far accommodation that results in improved visual acuity.Methods: Myopic children (n = 95 were treated for 3-minute sessions up to twice a week for 12–106 weeks. We stimulated quick cycles of near/far accommodation by displaying a visual object on a LCD screen and moving the screen in cycles from a near (25 cm to a far (70 cm point and back, while keeping the retinal projection size and brightness of the object constant. Results: Mechanistically, we noted pupillary constriction upon far accommodation in trained myopic children, which was not seen in normal subjects or in untrained myopic children. Eighty five percent (52/61 of trained myopic right eyes with two sessions weekly experienced improved visual acuity (VA by more than 0.1 logMAR units with an average improvement of 0.30 ± 0.03 standard error of mean (SEM logMAR units. With maintained training, most eyes’ improved VA stayed almost constant, for more than 50 weeks in the case of 12 long trained subjects

  3. Organic Solar Cells Performances Improvement Induced by Interface Buffer Layers

    OpenAIRE

    Bernède, J. C.; Godoy, A.; Cattin, L; Diaz, F. R.; MORSLI, M; Valle, M. A. del

    2010-01-01

    In the last 22 years that have elapsed since the pioneering work of Tang [Tang, Appl. Phys. Lett., 1986], significant improvement in the fundamental understanding and cells construction have led to efficiencies higher than 6%. The new concept of polymer:fullerene BHJ solar cells has allowed dramatic improvements in devices efficiency. It has induced a healthy competition with the multi-heterojunction devices base on small organic molecules, which induces significant progress in both cells fam...

  4. Calcium dynamics in root cells of Arabidopsis thaliana visualized with selective plane illumination microscopy.

    Directory of Open Access Journals (Sweden)

    Alex Costa

    Full Text Available Selective Plane Illumination Microscopy (SPIM is an imaging technique particularly suited for long term in-vivo analysis of transparent specimens, able to visualize small organs or entire organisms, at cellular and eventually even subcellular resolution. Here we report the application of SPIM in Calcium imaging based on Förster Resonance Energy Transfer (FRET. Transgenic Arabidopsis plants expressing the genetically encoded-FRET-based Ca(2+ probe Cameleon, in the cytosol or nucleus, were used to demonstrate that SPIM enables ratiometric fluorescence imaging at high spatial and temporal resolution, both at tissue and single cell level. The SPIM-FRET technique enabled us to follow nuclear and cytosolic Ca(2+ dynamics in Arabidopsis root tip cells, deep inside the organ, in response to different stimuli. A relevant physiological phenomenon, namely Ca(2+ signal percolation, predicted in previous studies, has been directly visualized.

  5. Stem Cell Imaging: Tools to Improve Cell Delivery and Viability

    Science.gov (United States)

    Wang, Junxin; Jokerst, Jesse V.

    2016-01-01

    Stem cell therapy (SCT) has shown very promising preclinical results in a variety of regenerative medicine applications. Nevertheless, the complete utility of this technology remains unrealized. Imaging is a potent tool used in multiple stages of SCT and this review describes the role that imaging plays in cell harvest, cell purification, and cell implantation, as well as a discussion of how imaging can be used to assess outcome in SCT. We close with some perspective on potential growth in the field. PMID:26880997

  6. Environmental enrichment preserved lifelong ocular dominance plasticity, but did not improve visual abilities.

    Science.gov (United States)

    Greifzu, Franziska; Kalogeraki, Evgenia; Löwel, Siegrid

    2016-05-01

    In standard cage (SC)-raised mice, ocular dominance (OD) plasticity of the primary visual cortex (V1) induced by monocular deprivation (MD) is maximal in juveniles, declines in adults, and is absent beyond postnatal day (PD) 110. Raising mice in an enriched environment (EE) preserved a juvenile-like OD plasticity after 7 days of MD until at least PD196, mediated by reductions of deprived eye responses in V1. Whether the sensitive phase for OD plasticity can be prolonged into older age and whether long-term EE modifies visual abilities was not yet known. Here, we demonstrate that EE raising enables lifelong OD plasticity. In contrast to PD200 EE-mice, the preserved OD shift in both >PD400 and >PD700 EE-mice was mediated by increases in open eye responses in V1 (adult OD plasticity). When SC-mice were transferred to EE after PD110, OD plasticity was restored until PD922. Moreover, visual abilities tested by both optomotry and the visual water task and interindividual variability were not different between PD700 SC- and EE-mice. Taken together, EE raising enabled a lifelong OD plasticity but did not affect basic visual performance. PMID:27103526

  7. Visual cues do not improve skin lesion ABC(D) grading

    Science.gov (United States)

    Zanotto, Matteo; Ballerini, Lucia; Aldridge, Ben; Fisher, Robert B.; Rees, Jonathan

    2011-03-01

    In this work evidence is presented supporting the hypothesis that observers tend to evaluate very differently the same properties of given skin-lesion images. Results from previous experiments have been compared to new ones obtained where we gave additional prototypical visual cues to the users during their evaluation trials. Each property (colour, colour uniformity, asymmetry, border regularity, roughness of texture) had to be evaluated on a 0-10 range, with both linguistic descriptors and visual references at each end and in the middle (e.g. light/medium/dark for colour). A set of 22 images covering different clinical diagnoses has been used in the comparison with previous results. Statistical testing showed that only for a few test images the inclusion of the visual anchors reduced the variability of the grading for some of the properties. Despite such reduction, though, the average variance of each property still remains high even after the inclusion of the visual anchors. When considering each property, the average variance significantly changed for the roughness of texture, where the visual references caused an increase in the variability. With these results we can conclude that the variance of the answers observed in the previous experiments was not due to the lack of a standard definition of the extrema of the scale, but rather to a high variability in the way observers perceive and understand skin-lesion images.

  8. The Emergence of Contrast-Invariant Orientation Tuning in Simple Cells of Cat Visual Cortex

    OpenAIRE

    Finn, Ian M.; Priebe, Nicholas J.; Ferster, David

    2007-01-01

    Simple cells in primary visual cortex exhibit contrast-invariant orientation tuning, in seeming contradiction to feed-forward models relying on lateral geniculate nucleus (LGN) input alone. Contrast invariance has therefore been thought to depend on the presence of intracortical lateral inhibition. In vivo intracellular recordings instead suggest that contrast invariance can be explained by three properties of the excitatory pathway. 1) Depolarizations evoked by orthogonal stimuli are determi...

  9. Quantitative o perando visualization of the energy band depth profile in solar cells

    OpenAIRE

    Chen, Qi; Mao, Lin; LI, YAOWEN; Kong, Tao; Wu, Na; Ma, Changqi; Bai, Sai; Jin, Yizheng; Wu, Dan; Lu, Wei; Wang, Bing; Chen, Liwei

    2015-01-01

    The energy band alignment in solar cell devices is critically important because it largely governs elementary photovoltaic processes, such as the generation, separation, transport, recombination and collection of charge carriers. Despite the expenditure of considerable effort, the measurement of energy band depth profiles across multiple layers has been extremely challenging, especially for operando devices. Here we present direct visualization of the surface potential depth profile over the ...

  10. Genetic visualization with an improved GCaMP calcium indicator reveals spatiotemporal activation of the spinal motor neurons in zebrafish

    OpenAIRE

    Muto, Akira; Ohkura, Masamichi; Kotani, Tomoya; Higashijima, Shin-ichi; Nakai, Junichi; Kawakami, Koichi

    2011-01-01

    Animal behaviors are generated by well-coordinated activation of neural circuits. In zebrafish, embryos start to show spontaneous muscle contractions at 17 to 19 h postfertilization. To visualize how motor circuits in the spinal cord are activated during this behavior, we developed GCaMP-HS (GCaMP-hyper sensitive), an improved version of the genetically encoded calcium indicator GCaMP, and created transgenic zebrafish carrying the GCaMP-HS gene downstream of the Gal4-recognition sequence, UAS...

  11. Real-time visualization of oxygen partial pressures in straight channels of running polymer electrolyte fuel cell with water plugging

    Science.gov (United States)

    Nagase, Katsuya; Suga, Takeo; Nagumo, Yuzo; Uchida, Makoto; Inukai, Junji; Nishide, Hiroyuki; Watanabe, Masahiro

    2015-01-01

    Visualization inside polymer electrolyte fuel cells (PEFCs) for elucidating the reaction distributions is expected to improve the performance, durability, and stability. An oxygen-sensitive film of a luminescent porphyrin was used to visualize the oxygen partial pressures in five straight gas-flow channels of a running PEFC with liquid-water blockages formed at the end of the channels. The blockage greatly lowered and unstabilized the cell voltage. The oxygen partial pressure decreased nearly to 0 kPa in the blocked channel. With a water blockage in a channel, the oxygen partial pressures in the adjacent channels were lowered due to an extra demand of oxygen consumption. When the number of the blocked channels increased, the oxygen partial pressure in the unblocked channels became much lowered. When the water blockages disappeared, the oxygen partial pressures quickly returned to the values before plugging. The influence of the cross flows of air through the gas diffusion layers in straight channels was much smaller than that in serpentine flow channels.

  12. A CAI System for Visually Impaired Children to Improve Abilities of Orientation and Mobility

    Science.gov (United States)

    Yoneda, Takahiro; Kudo, Hiroaki; Minagawa, Hiroki; Ohnishi, Noboru; Matsubara, Shizuya

    Some visually impaired children have difficulty in simple locomotion, and need orientation and mobility training. We developed a computer assisted instruction system which assists this training. A user realizes a task given by a tactile map and synthesized speech. The user walks around a room according to the task. The system gives the gap of walk path from its target path via both auditory and tactile feedback after the end of a task. Then the user can understand how well the user walked. We describe the detail of the proposed system and task, and the experimental result with three visually impaired children.

  13. An Improved Model of Producing Saliency Map for Visual Attention System

    Science.gov (United States)

    Huang, Jingang; Kong, Bin; Cheng, Erkang; Zheng, Fei

    The iLab Neuromorphic Vision Toolkit (iINVT), steadily kept up to date by the group around Laurent Itti, is one of the currently best known attention systems. Their model of bottom up or saliency-based visual attention as well as their implementation serves as a basis for many research groups. How to combine the feature maps finally into the saliency map is a key point for this kind of visual attention system. We modified the original model of Laurent Itti to make it more corresponding with our perception.

  14. Technological Improvements in the DARHT II Accelerator Cells

    CERN Document Server

    Prichard, Benjamin A; Bieniosek, Frank; Briggs, Richard J; Chow, Ken; Fawley, William M; Genoni, Thomas E; Henestroza, Enrique; Hughes, Thomas P; Kang, Mike; Nielsen, Kurt; Reginato, Lou; Waldron, William

    2005-01-01

    DARHT employs two perpendicular electron Linear Induction Accelerators to produce intense, bremsstrahlung x-ray pulses for flash radiography. The second axis, DARHT II, features an 18 MeV, 2-kA, 2-microsecond accelerator. DARHT II accelerator cells have undergone a series of test and modeling efforts to fully understand their sub par performance. These R&D efforts have led to a better understanding of Linear Induction Accelerator physics for the unique DARHT II design. Specific improvements have been identified and tested. Improvements in the cell oil region, the cell vacuum region, and the PFNs have been implemented in the prototype units that have doubled the cell's performance. A series of prototype acceptance test are underway on a number of prototype units to demonstrate that the required cell lifetime is met at the improved performance levels. Early acceptance tests indicate that the lifetime requirements are being exceeded. The shortcomings of the previous design are summarized. The improvements to...

  15. Spontaneous Resolution of Retinal Pigment Epithelial Detachments and Visual Improvement in Patient with MPGN II: A Case Report

    Directory of Open Access Journals (Sweden)

    T. Empeslidis

    2012-01-01

    Full Text Available A 31-year-old female suffering from membranoproliferative glomerulonephritis type II (MPGN II presented to the Eye Casualty Department reporting a history of blurred and distorted vision. The patient appeared to have drusenoid retinal epithelial detachments and minimal intraretinal fluid. The subretinal deposits, basal lamina drusen, and pigment epithelial detachment appeared to resemble a “stars in the sky” picture with no symmetry between the eyes. The retinal pigment epithelial detachments improved and flattened over 18 month. and the best corrected visual acuity improved in the most affected eye. There was no evidence of neovascularization, and the intraretinal fluid disappeared spontaneously.

  16. Visual bone marrow mesenchymal stem cell transplantation in the repair of spinal cord injury

    OpenAIRE

    Rui-ping Zhang; Cheng Xu; Yin Liu; Jian-ding Li; Jun Xie

    2015-01-01

    An important factor in improving functional recovery from spinal cord injury using stem cells is maximizing the number of transplanted cells at the lesion site. Here, we established a contusion model of spinal cord injury by dropping a weight onto the spinal cord at T 7-8 . Superparamagnetic iron oxide-labeled bone marrow mesenchymal stem cells were transplanted into the injured spinal cord via the subarachnoid space. An outer magnetic field was used to successfully guide the labeled cells to...

  17. Improving visual attention : the effect of Warning signs with different formats

    OpenAIRE

    Yao, Zheng; SUTO, Hidetsugu

    2015-01-01

    Designed warning signs were applied in this study to describe the performance of visual attention with different formats of stimulation. The dependent variables had be obtained from an eye movement experiment. A new proposal about how to sort experimental materials will be proposed.

  18. Rapid Resumption of Interrupted Search Is Independent of Age-Related Improvements in Visual Search

    Science.gov (United States)

    Lleras, Alejandro; Porporino, Mafalda; Burack, Jacob A.; Enns, James T.

    2011-01-01

    In this study, 7-19-year-olds performed an interrupted visual search task in two experiments. Our question was whether the tendency to respond within 500 ms after a second glimpse of a display (the "rapid resumption" effect ["Psychological Science", 16 (2005) 684-688]) would increase with age in the same way as overall search efficiency. The…

  19. Improving Synthetic Biology Communication: Recommended Practices for Visual Depiction and Digital Submission of Genetic Designs.

    Science.gov (United States)

    Hillson, Nathan J; Plahar, Hector A; Beal, Jacob; Prithviraj, Ranjini

    2016-06-17

    Research is communicated more effectively and reproducibly when articles depict genetic designs consistently and fully disclose the complete sequences of all reported constructs. ACS Synthetic Biology is now providing authors with updated guidance and piloting a new tool and publication workflow that facilitate compliance with these recommended practices and standards for visual representation and data exchange. PMID:27267452

  20. From Open Geographical Data to Tangible Maps: Improving the Accessibility of Maps for Visually Impaired People

    Science.gov (United States)

    Ducasse, J.; Macé, M.; Jouffrais, C.

    2015-08-01

    Visual maps must be transcribed into (interactive) raised-line maps to be accessible for visually impaired people. However, these tactile maps suffer from several shortcomings: they are long and expensive to produce, they cannot display a large amount of information, and they are not dynamically modifiable. A number of methods have been developed to automate the production of raised-line maps, but there is not yet any tactile map editor on the market. Tangible interactions proved to be an efficient way to help a visually impaired user manipulate spatial representations. Contrary to raised-line maps, tangible maps can be autonomously constructed and edited. In this paper, we present the scenarios and the main expected contributions of the AccessiMap project, which is based on the availability of many sources of open spatial data: 1/ facilitating the production of interactive tactile maps with the development of an open-source web-based editor; 2/ investigating the use of tangible interfaces for the autonomous construction and exploration of a map by a visually impaired user.

  1. Using Real-Time Visual Feedback to Improve Posture at Computer Workstations

    Science.gov (United States)

    Sigurdsson, Sigurdur O.; Austin, John

    2008-01-01

    The purpose of the current study was to examine the effects of a multicomponent intervention that included discrimination training, real-time visual feedback, and self-monitoring on postural behavior at a computer workstation in a simulated office environment. Using a nonconcurrent multiple baseline design across 8 participants, the study assessed…

  2. Machine-Part cell formation through visual decipherable clustering of Self Organizing Map

    CERN Document Server

    Chattopadhyay, Manojit; Dan, Pranab K; 10.1007/s00170-010-2802-4

    2011-01-01

    Machine-part cell formation is used in cellular manufacturing in order to process a large variety, quality, lower work in process levels, reducing manufacturing lead-time and customer response time while retaining flexibility for new products. This paper presents a new and novel approach for obtaining machine cells and part families. In the cellular manufacturing the fundamental problem is the formation of part families and machine cells. The present paper deals with the Self Organising Map (SOM) method an unsupervised learning algorithm in Artificial Intelligence, and has been used as a visually decipherable clustering tool of machine-part cell formation. The objective of the paper is to cluster the binary machine-part matrix through visually decipherable cluster of SOM color-coding and labelling via the SOM map nodes in such a way that the part families are processed in that machine cells. The Umatrix, component plane, principal component projection, scatter plot and histogram of SOM have been reported in t...

  3. A Visual Attention Based Improved Seam Carving For Content Aware Image Rescaling

    Directory of Open Access Journals (Sweden)

    Aparna P

    2015-04-01

    Full Text Available Content-aware image resizing is a kind of new and effective approach for image resizing, which preserves image content well and does not cause obvious distortion when changing the aspect ratio of images. Saliency detection plays important roles in many image processing applications, such as regions of interest extraction and image resizing. Effective resizing of images should not only use geometric constraints, but consider the image content as well. The basic idea beyond these algorithms is the removal of vertical and/or horizontal paths of pixels (i.e., seams containing low salient information. In The proposed system, present a method which exploits the gradient vector flow (GVF of the image to establish the paths to be considered during the resizing. The relevance of each GVF path is straightforward derived from an energy map related to the magnitude of the GVF associated to the image to be resized. To make more relevant, the visual content of the images during the content-aware resizing, also propose to select the generated GVF paths based on their visual saliency properties and a blending method in order to obtain better visual results in joining adjacent image regions after seams removal. The depth of the scene will be considered to make more visually consistent the resized images. In this way, visually important image regions are better preserved in the final resized image. The proposed technique has been tested, both qualitatively and quantitatively, by considering a representative data set of images labeled with corresponding salient objects (i.e., ground-truth maps. Experimental results demonstrate that our method preserves crucial salient regions better than other state-of-the-art algorithms.

  4. Optimizing autologous cell grafts to improve stem cell gene therapy.

    Science.gov (United States)

    Psatha, Nikoletta; Karponi, Garyfalia; Yannaki, Evangelia

    2016-07-01

    Over the past decade, stem cell gene therapy has achieved unprecedented curative outcomes for several genetic disorders. Despite the unequivocal success, clinical gene therapy still faces challenges. Genetically engineered hematopoietic stem cells are particularly vulnerable to attenuation of their repopulating capacity once exposed to culture conditions, ultimately leading to low engraftment levels posttransplant. This becomes of particular importance when transduction rates are low or/and competitive transplant conditions are generated by reduced-intensity conditioning in the absence of a selective advantage of the transduced over the unmodified cells. These limitations could partially be overcome by introducing megadoses of genetically modified CD34(+) cells into conditioned patients or by transplanting hematopoietic stem cells hematopoietic stem cells with high engrafting and repopulating potential. On the basis of the lessons gained from cord blood transplantation, we summarize the most promising approaches to date of increasing either the numbers of hematopoietic stem cells for transplantation or/and their engraftability, as a platform toward the optimization of engineered stem cell grafts. PMID:27106799

  5. A two- and three-dimensional approach for visualizing human embryonic stem cell differentiation

    DEFF Research Database (Denmark)

    Brøchner, Christian Beltoft; Vestentoft, Peter S; Lynnerup, Niels;

    2010-01-01

    Undifferentiated human embryonic stem cells are characterized by expression of specific cell markers like the transcription factors OCT4, SOX2, and NANOG, the stage-specific embryonic antigen SSEA4, and the tumor-related antigens TRA-1-60 and TRA-1-81 and by their ability to differentiate under...... accomplished. An extended version of this technique even allows for a high-magnification 3D-reconstruction of an area of interest (AOI), e.g., the developing hepatic stem cells. These techniques allow both a 2D and a 3D visualization of hESC colonies and lead to new insights into and information about the...... interaction of stem cells....

  6. Performance of the Sellick maneuver significantly improves when residents and trained nurses use a visually interactive guidance device in simulation

    International Nuclear Information System (INIS)

    We examined the proper performance of the Sellick maneuver, a maneuver used to reduce the risk of aspiration of stomach contents during induction of general anesthesia, using a novel device that measures and visualizes the force applied to the cricoid cartilage using thin-film force sensitive resistors in a form suitable for in vivo use. Performance was tested in three stages with twenty anaesthesiology residents and twenty trained operating room nurses. Firstly, subjects applied force to the cricoid cartilage as was customary to them. Secondly, subjects used the device to guide the application of that force. Thirdly, subjects were again asked to perform the manoeuvre without visual guidance. Each test lasted 1 min and the amount of force applied was measured throughout. Overall, the Sellick maneuver was often not applied properly, with large variance between individual subjects. Performance and inter-subject consistency improved to a very highly significant degree when subjects were able to use the device as a visual guide (p < 0.001). Subsequent significant improvements in performances during the last, unguided test demonstrated that the device initiated learning. (paper)

  7. Data visualization

    CERN Document Server

    Azzam, Tarek

    2013-01-01

    Do you communicate data and information to stakeholders? In Part 1, we introduce recent developments in the quantitative and qualitative data visualization field and provide a historical perspective on data visualization, its potential role in evaluation practice, and future directions. Part 2 delivers concrete suggestions for optimally using data visualization in evaluation, as well as suggestions for best practices in data visualization design. It focuses on specific quantitative and qualitative data visualization approaches that include data dashboards, graphic recording, and geographic information systems (GIS). Readers will get a step-by-step process for designing an effective data dashboard system for programs and organizations, and various suggestions to improve their utility.

  8. Melatonin improves spermatogonial stem cells transplantation efficiency in azoospermic mice

    Directory of Open Access Journals (Sweden)

    Mohammadreza Gholami

    2014-02-01

    Conclusion: Administration of melatonin (20 mg/kg simultaneously with transplantation of spermatogonial stem cells in azoospermia mouse testis increases the efficiency of transplantation and improves structural properties of the testes tissue.

  9. The role of cell adhesion molecules in visual circuit formation: From neurite outgrowth to maps and synaptic specificity

    OpenAIRE

    Missaire, Mégane; Hindges, Robert

    2015-01-01

    ABSTRACT The formation of visual circuitry is a multistep process that involves cell–cell interactions based on a range of molecular mechanisms. The correct implementation of individual events, including axon outgrowth and guidance, the formation of the topographic map, or the synaptic targeting of specific cellular subtypes, are prerequisites for a fully functional visual system that is able to appropriately process the information captured by the eyes. Cell adhesion molecules (CAMs) with th...

  10. Towards Improving the Mental Model of Software Developers through Cartographic Visualization

    CERN Document Server

    Kuhn, Adrian; Nierstrasz, Oscar

    2010-01-01

    Software is intangible and knowledge about software systems is typically tacit. The mental model of software developers is thus an important factor in software engineering. It is our vision that developers should be able to refer to code as being "up in the north", "over in the west", or "down-under in the south". We want to provide developers, and everyone else involved in software development, with a *shared*, spatial and stable mental model of their software project. We aim to reinforce this by embedding a cartographic visualization in the IDE (Integrated Development Environment). The visualization is always visible in the bottom-left, similar to the GPS navigation device for car drivers. For each development task, related information is displayed on the map. In this paper we present CODEMAP, an eclipse plug-in, and report on preliminary results from an ongoing user study with professional developers and students.

  11. Tools for Improving the Characterization and Visualization of Changes in Neuro-Oncology Patients

    OpenAIRE

    Hsu, William; Taira, Ricky K.

    2010-01-01

    Capturing how a patient’s medical problems change over time is important for understanding the progression of a disease, its effects, and response to treatment. We describe two prototype tools that are being developed as part of a data processing pipeline for standardizing, structuring, and visualizing problems and findings documented in clinical reports associated with neuro-oncology patients. Given a list of problems and findings identified using a natural language processing (NLP) system, ...

  12. Improved MOGA-tuning and visualization for a hybrid control system

    OpenAIRE

    Stirrup, R.; Chipperfield, A.J.

    2005-01-01

    A hybrid controller is developed for a solar-thermal power plant using a gain-scheduled controller with feedforward to control the more linear operating regimes and a fuzzy PI incremental controller for the highly nonlinear operating region of the plant. An enhanced method of MOGA-tuning is employed by first optimizing the number of input/output membership functions using neuro-fuzzy data clustering. Enhancements to the visualization properties of the MOGA's graphical user interface are evalu...

  13. Allium sativum L. Improves Visual Memory and Attention in Healthy Human Volunteers

    OpenAIRE

    Sara Tasnim; Parsa Sanjana Haque; Md. Sazzadul Bari; Md Monir Hossain; Sardar Mohd. Ashraful Islam; Mohammad Shahriar; Mohiuddin Ahmed Bhuiyan; Muhammad Shahdaat Bin Sayeed

    2015-01-01

    Studies have shown that Allium sativum L. (AS) protects amyloid-beta peptide-induced apoptosis, prevents oxidative insults to neurons and synapses, and thus prevent Alzheimer's disease progression in experimental animals. However, there is no experimental evidence in human regarding its putative role in memory and cognition. We have studied the effect of AS consumption by healthy human volunteers on visual memory, verbal memory, attention, and executive function in comparison to control subje...

  14. Verbal to visual code switching improves working memory in older adults: An fMRI study

    Directory of Open Access Journals (Sweden)

    Mariko eOsaka

    2012-02-01

    Full Text Available The effects of verbal to visual code switching training on working memory performance were investigated in the elderly. Twenty-five elderly people were introduced to a verbal to visual code switching strategy (training group while the other 25 were not (control group. During this strategy training period, participants in the training group practiced focusing their attention on a target word both by drawing the target’s figure and by forming mental images of the target. To explore the neural substrates underlying strategy effects, fMRI was used to measure brain activity of the elderly in both groups while they performed a working memory task (reading span test, RST, before and after the attention training period. RST recognition accuracy was enhanced only in the training group. fMRI data for this group showed increased activation in the anterior cingulate cortex (ACC, a region that typically shows activation in young adults performing the RST. Furthermore, activation was found both in the left and right inferior parietal lobule (IPL and right superior parietal lobule (SPL, while there was no activation in these areas for the control group. These findings suggest that using a strategy of verbal to visual code switching helped the elderly participants to maintain the words in working memory.

  15. Improved Cluster Identification and Visualization in High-Dimensional Data Using Self-Organizing Maps

    Science.gov (United States)

    Manukyan, N.; Eppstein, M. J.; Rizzo, D. M.

    2011-12-01

    A Kohonen self-organizing map (SOM) is a type of unsupervised artificial neural network that results in a self-organized projection of high-dimensional data onto a low-dimensional feature map, wherein vector similarity is implicitly translated into topological closeness, enabling clusters to be identified. In recently published work [1], 209 microbial variables from 22 monitoring wells around the leaking Schuyler Falls Landfill in Clinton, NY [2] were analyzed using a multi-stage non-parametric process to explore how microbial communities may act as indicators for the gradient of contamination in groundwater. The final stage of their analysis used a weighted SOM to identify microbial signatures in this high dimensionality data set that correspond to clean, fringe, and contaminated soils. Resulting clusters were visualized with the standard unified distance matrix (U-matrix). However, while the results of this analysis were very promising, visualized boundaries between clusters in the SOM were indistinct and required manual and somewhat arbitrary identification. In this contribution, we introduce (i) a new cluster reinforcement (CR) phase to be run subsequent to traditional SOM training for automatic sharpening of cluster boundaries, and (ii) a new boundary matrix (B-matrix) approach for visualization of the resulting cluster boundaries. The CR-phase differs from standard SOM training in several ways, most notably by using a feature-based neighborhood function rather than a topologically-based neighborhood function. In contrast to the U-matrix, the B-matrix can be directly superimposed on heat maps of the individual features (as output by the SOM) using grid lines whose thickness corresponds to inter-cluster distances. By thresholding the displayed lines, one obtains hierarchical control of the visual level of cluster resolution. We first illustrate the advantages of these methods on a small synthetic test case, and then apply them to the Schuyler Falls landfill

  16. Nanoscale dimples for improved absorption in organic solar cells

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jaroslaw; Rubahn, Horst-Günter; Madsen, Morten

    Organic solar cells (OSC’s) have attracted much attention in the past years due to their potential low-cost, light-weight and mechanical flexibility. A method for improving the power conversion efficiencies of the devices is by incorporating structured electrodes in the solar cell architecture...... ordered and discorded dimple arrangement and their contribution to light management is presented. Such dimples can later be employed to fabricate nanostructured electrodes in P3HT/PCBM organic solar cells....

  17. Teneurin-3 Specifies Morphological and Functional Connectivity of Retinal Ganglion Cells in the Vertebrate Visual System

    Directory of Open Access Journals (Sweden)

    Paride Antinucci

    2013-11-01

    Full Text Available A striking feature of the CNS is the precise wiring of its neuronal connections. During vertebrate visual system development, different subtypes of retinal ganglion cells (RGCs form specific connections with their corresponding synaptic partners. However, the underlying molecular mechanisms remain to be fully elucidated. Here, we report that the cell-adhesive transmembrane protein Teneurin-3 (Tenm3 is required by zebrafish RGCs for acquisition of their correct morphological and functional connectivity in vivo. Teneurin-3 is expressed by RGCs and their presynaptic amacrine and postsynaptic tectal cell targets. Knockdown of Teneurin-3 leads to RGC dendrite stratification defects within the inner plexiform layer, as well as mistargeting of dendritic processes into outer portions of the retina. Moreover, a subset of RGC axons exhibits tectal laminar arborization errors. Finally, functional analysis of RGCs targeting the tectum reveals a selective deficit in the development of orientation selectivity after Teneurin-3 knockdown. These results suggest that Teneurin-3 plays an instructive role in the functional wiring of the vertebrate visual system.

  18. Audio-Visual and Autogenic Relaxation Alter Amplitude of Alpha EEG Band, Causing Improvements in Mental Work Performance in Athletes.

    Science.gov (United States)

    Mikicin, Mirosław; Kowalczyk, Marek

    2015-09-01

    The aim of the present study was to investigate the effect of regular audio-visual relaxation combined with Schultz's autogenic training on: (1) the results of behavioral tests that evaluate work performance during burdensome cognitive tasks (Kraepelin test), (2) changes in classical EEG alpha frequency band, neocortex (frontal, temporal, occipital, parietal), hemisphere (left, right) versus condition (only relaxation 7-12 Hz). Both experimental (EG) and age-and skill-matched control group (CG) consisted of eighteen athletes (ten males and eight females). After 7-month training EG demonstrated changes in the amplitude of mean electrical activity of the EEG alpha bend at rest and an improvement was significantly changing and an improvement in almost all components of Kraepelin test. The same examined variables in CG were unchanged following the period without the intervention. Summing up, combining audio-visual relaxation with autogenic training significantly improves athlete's ability to perform a prolonged mental effort. These changes are accompanied by greater amplitude of waves in alpha band in the state of relax. The results suggest usefulness of relaxation techniques during performance of mentally difficult sports tasks (sports based on speed and stamina, sports games, combat sports) and during relax of athletes. PMID:26016588

  19. Demonstration of a visual cell-based assay for screening glucose transporter 4 translocation modulators in real time

    Indian Academy of Sciences (India)

    Maleppillil Vavachan Vijayakumar; Amrendra Kumar Ajay; Manoj Kumar Bhat

    2010-12-01

    Insulin-stimulated translocation of glucose transporter 4 (GLUT4) to cell membrane leading to glucose uptake is the rate-limiting step in diabetes. It is also a defined target of antidiabetic drug research. Existing GLUT4 translocation assays are based on time-consuming immunoassays and are hampered by assay variability and low sensitivity. We describe a real-time, visual, cell-based qualitative GLUT4 translocation assay using CHO-HIRc-myc-GLUT4eGFP cells that stably express myc- and eGFP-tagged GLUT4 in addition to human insulin receptor (HIRc). GLUT4 translocation is visualized by live cell imaging based on GFP fluorescence by employing a cooled charge-coupled device camera attached to a fluorescent microscope. This video imaging method and further quantitative analysis of GLUT4 on the cell membrane provide rapid and foolproof visual evidence that this method is suitable for screening GLUT4 translocation modulators.

  20. Ciprofloxacin Improves the Stemness of Human Dermal Papilla Cells

    Directory of Open Access Journals (Sweden)

    Chayanin Kiratipaiboon

    2016-01-01

    Full Text Available Improvement in the expansion method of adult stem cells may augment their use in regenerative therapy. Using human dermal papilla cell line as well as primary dermal papilla cells as model systems, the present study demonstrated that ciprofloxacin treatment could prevent the loss of stemness during culture. Clonogenicity and stem cell markers of dermal papilla cells were shown to gradually decrease in the culture in a time-dependent manner. Treatment of the cells with nontoxic concentrations of ciprofloxacin could maintain both stem cell morphology and clonogenicity, as well as all stem cells markers. We found that ciprofloxacin exerted its effect through ATP-dependent tyrosine kinase/glycogen synthase kinase3β dependent mechanism which in turn upregulated β-catenin. Besides, ciprofloxacin was shown to induce epithelial-mesenchymal transition in DPCs as the transcription factors ZEB1 and Snail were significantly increased. Furthermore, the self-renewal proteins of Wnt/β-catenin pathway, namely, Nanog and Oct-4 were significantly upregulated in the ciprofloxacin-treated cells. The effects of ciprofloxacin in preserving stem cell features were confirmed in the primary dermal papilla cells directly obtained from human hair follicles. Together, these results revealed a novel application of ciprofloxacin for stem cell maintenance and provided the underlying mechanisms that are responsible for the stemness in dermal papilla cells.

  1. Exercise and physical training improve physical function in older adults with visual impairments but their effect on falls is unclear: a systematic review

    Directory of Open Access Journals (Sweden)

    Michael Gleeson

    2014-09-01

    [Gleeson M, Sherrington C, Keay L (2014 Exercise and physical training improve physical function in older adults with visual impairments but their effect on falls is unclear: a systematic review. Journal of Physiotherapy 60: 130–135

  2. Visa: AN Automatic Aware and Visual Aids Mechanism for Improving the Correct Use of Geospatial Data

    Science.gov (United States)

    Hong, J. H.; Su, Y. T.

    2016-06-01

    With the fast growth of internet-based sharing mechanism and OpenGIS technology, users nowadays enjoy the luxury to quickly locate and access a variety of geospatial data for the tasks at hands. While this sharing innovation tremendously expand the possibility of application and reduce the development cost, users nevertheless have to deal with all kinds of "differences" implicitly hidden behind the acquired georesources. We argue the next generation of GIS-based environment, regardless internet-based or not, must have built-in knowledge to automatically and correctly assess the fitness of data use and present the analyzed results to users in an intuitive and meaningful way. The VISA approach proposed in this paper refer to four different types of visual aids that can be respectively used for addressing analyzed results, namely, virtual layer, informative window, symbol transformation and augmented TOC. The VISA-enabled interface works in an automatic-aware fashion, where the standardized metadata serve as the known facts about the selected geospatial resources, algorithms for analyzing the differences of temporality and quality of the geospatial resources were designed and the transformation of analyzed results into visual aids were automatically executed. It successfully presents a new way for bridging the communication gaps between systems and users. GIS has been long seen as a powerful integration tool, but its achievements would be highly restricted if it fails to provide a friendly and correct working platform.

  3. Improving exposure assessment in environmental epidemiology: Application of spatio-temporal visualization tools

    Science.gov (United States)

    Meliker, Jaymie R.; Slotnick, Melissa J.; Avruskin, Gillian A.; Kaufmann, Andrew; Jacquez, Geoffrey M.; Nriagu, Jerome O.

    2005-05-01

    A thorough assessment of human exposure to environmental agents should incorporate mobility patterns and temporal changes in human behaviors and concentrations of contaminants; yet the temporal dimension is often under-emphasized in exposure assessment endeavors, due in part to insufficient tools for visualizing and examining temporal datasets. Spatio-temporal visualization tools are valuable for integrating a temporal component, thus allowing for examination of continuous exposure histories in environmental epidemiologic investigations. An application of these tools to a bladder cancer case-control study in Michigan illustrates continuous exposure life-lines and maps that display smooth, continuous changes over time. Preliminary results suggest increased risk of bladder cancer from combined exposure to arsenic in drinking water (>25 μg/day) and heavy smoking (>30 cigarettes/day) in the 1970s and 1980s, and a possible cancer cluster around automotive, paint, and organic chemical industries in the early 1970s. These tools have broad application for examining spatially- and temporally-specific relationships between exposures to environmental risk factors and disease.

  4. Improving the visualization of electron-microscopy data through optical flow interpolation

    KAUST Repository

    Carata, Lucian

    2013-01-01

    Technical developments in neurobiology have reached a point where the acquisition of high resolution images representing individual neurons and synapses becomes possible. For this, the brain tissue samples are sliced using a diamond knife and imaged with electron-microscopy (EM). However, the technique achieves a low resolution in the cutting direction, due to limitations of the mechanical process, making a direct visualization of a dataset difficult. We aim to increase the depth resolution of the volume by adding new image slices interpolated from the existing ones, without requiring modifications to the EM image-capturing method. As classical interpolation methods do not provide satisfactory results on this type of data, the current paper proposes a re-framing of the problem in terms of motion volumes, considering the depth axis as a temporal axis. An optical flow method is adapted to estimate the motion vectors of pixels in the EM images, and this information is used to compute and insert multiple new images at certain depths in the volume. We evaluate the visualization results in comparison with interpolation methods currently used on EM data, transforming the highly anisotropic original dataset into a dataset with a larger depth resolution. The interpolation based on optical flow better reveals neurite structures with realistic undistorted shapes, and helps to easier map neuronal connections. © 2011 ACM.

  5. Inverting adherent cells for visualizing ECM interactions at the basal cell side

    International Nuclear Information System (INIS)

    Interactions with the extracellular matrix (ECM) govern a wide range of cellular functions, including survival, migration and invasion. However, in adherent cells these interactions occur primarily on the basal cell side, making them inaccessible to high-resolution, surface-scanning imaging techniques such as atomic force microscopy (AFM) or scanning electron microscopy (SEM). Here we describe a fast and reliable method for inverting adherent cells, exposing the basal cell membrane for direct analysis by AFM or SEM in combination with fluorescence microscopy. Cells including their matrix adhesion sites remain intact during the inversion process and are transferred together with the complete array of basally associated ECM proteins. Molecular features of ECM proteins, such as the characteristic 67 nm collagen D-periodicity, are well preserved after inversion. To demonstrate the versatility of the method, we compared basal interactions of fibroblasts with fibrillar collagen I and fibronectin matrices. While fibroblasts remodel the fibronectin layer exclusively from above, they actively invade even thin collagen layers by contacting individual collagen nanofibrils both basally and apically through a network of cellular extensions. Cell–matrix entanglement coincides with enhanced cell spreading and flattening, indicating that nanoscale ECM interactions govern macroscopic changes in cell morphology. The presented cell inversion technique can thus provide novel insight into nanoscale cell–matrix interactions at the basal cell side. - Highlights: ► We present a novel method for inverting adherent cells to expose the basal cell side. ► Basal cell sides can be imaged at high resolution by AFM and SEM. ► Cells can be inverted together with the underlying extracellular matrix. ► AFM images of inverted cells provide a nanoscale look at basal cell–ECM interactions

  6. A system and methodology for high-content visual screening of individual intact living cells in suspension

    Science.gov (United States)

    Renaud, Olivier; Heintzmann, Rainer; Sáez-Cirión, Asier; Schnelle, Thomas; Mueller, Torsten; Shorte, Spencer

    2007-02-01

    Three dimensional imaging provides high-content information from living intact biology, and can serve as a visual screening cue. In the case of single cell imaging the current state of the art uses so-called "axial through-stacking". However, three-dimensional axial through-stacking requires that the object (i.e. a living cell) be adherently stabilized on an optically transparent surface, usually glass; evidently precluding use of cells in suspension. Aiming to overcome this limitation we present here the utility of dielectric field trapping of single cells in three-dimensional electrode cages. Our approach allows gentle and precise spatial orientation and vectored rotation of living, non-adherent cells in fluid suspension. Using various modes of widefield, and confocal microscope imaging we show how so-called "microrotation" can provide a unique and powerful method for multiple point-of-view (three-dimensional) interrogation of intact living biological micro-objects (e.g. single-cells, cell aggregates, and embryos). Further, we show how visual screening by micro-rotation imaging can be combined with micro-fluidic sorting, allowing selection of rare phenotype targets from small populations of cells in suspension, and subsequent one-step single cell cloning (with high-viability). Our methodology combining high-content 3D visual screening with one-step single cell cloning, will impact diverse paradigms, for example cytological and cytogenetic analysis on haematopoietic stem cells, blood cells including lymphocytes, and cancer cells.

  7. Formation of nanofilms on cell surfaces to improve the insertion efficiency of a nanoneedle into cells

    Energy Technology Data Exchange (ETDEWEB)

    Amemiya, Yosuke [Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 4, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8562 (Japan); Kawano, Keiko [Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-26 Naka-cho, Koganei, Tokyo 184-8588 (Japan); Matsusaki, Michiya; Akashi, Mitsuru [Department of Applied Chemistry, Graduate School of Engineering Science, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Nakamura, Noriyuki [Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-26 Naka-cho, Koganei, Tokyo 184-8588 (Japan); Nakamura, Chikashi, E-mail: chikashi-nakamura@aist.go.jp [Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 4, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8562 (Japan); Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-26 Naka-cho, Koganei, Tokyo 184-8588 (Japan)

    2012-04-13

    Highlights: Black-Right-Pointing-Pointer We examined the insertion efficiency of nanoneedles into fibroblast and neural cells. Black-Right-Pointing-Pointer Nanofilms formed on cell surfaces improved the insertion efficiency of nanoneedles. Black-Right-Pointing-Pointer Nanofilms improved the insertion efficiency even in Y27632-treated cells. -- Abstract: A nanoneedle, an atomic force microscope (AFM) tip etched to 200 nm in diameter and 10 {mu}m in length, can be inserted into cells with the aid of an AFM and has been used to introduce functional molecules into cells and to analyze intracellular information with minimal cell damage. However, some cell lines have shown low insertion efficiency of the nanoneedle. Improvement in the insertion efficiency of a nanoneedle into such cells is a significant issue for nanoneedle-based cell manipulation and analysis. Here, we have formed nanofilms composed of extracellular matrix molecules on cell surfaces and found that the formation of the nanofilms improved insertion efficiency of a nanoneedle into fibroblast and neural cells. The nanofilms were shown to improve insertion efficiency even in cells in which the formation of actin stress fibers was inhibited by the ROCK inhibitor Y27632, suggesting that the nanofilms with the mesh structure directly contributed to the improved insertion efficiency of a nanoneedle.

  8. Visualization of N-acylhomoserine lactone-mediated cell-cell communication between bacteria colonizing the tomato rhizosphere

    DEFF Research Database (Denmark)

    Steidle, A.; Sigl, K.; Schuhegger, R.;

    2001-01-01

    developed and characterized novel Gfp-based monitor strains that allow in situ visualization of AHL-mediated communication between individual cells in the plant rhizosphere. For this purpose, three Gfp-based AHL sensor plasmids that respond to different spectra of AHL molecules were transferred into AHL...... into the chromosome of AHL-negative P. putida strain F117 an AHL sensor cassette that responds to the presence of long-chain AHLs with the expression of Gfp. This monitor strain was used to demonstrate that the indigenous bacterial community colonizing the roots of tomato plants growing in nonsterile soil produces...

  9. Specific visualization of glioma cells in living low-grade tumor tissue.

    Directory of Open Access Journals (Sweden)

    Sven R Kantelhardt

    Full Text Available BACKGROUND: The current therapy of malignant gliomas is based on surgical resection, radio-chemotherapy and chemotherapy. Recent retrospective case-series have highlighted the significance of the extent of resection as a prognostic factor predicting the course of the disease. Complete resection in low-grade gliomas that show no MRI-enhanced images are especially difficult. The aim in this study was to develop a robust, specific, new fluorescent probe for glioma cells that is easy to apply to live tumor biopsies and could identify tumor cells from normal brain cells at all levels of magnification. METHODOLOGY/PRINCIPAL FINDINGS: In this investigation we employed brightly fluorescent, photostable quantum dots (QDs to specifically target epidermal growth factor receptor (EGFR that is upregulated in many gliomas. Living glioma and normal cells or tissue biopsies were incubated with QDs coupled to EGF and/or monoclonal antibodies against EGFR for 30 minutes, washed and imaged. The data include results from cell-culture, animal model and ex vivo human tumor biopsies of both low-grade and high-grade gliomas and show high probe specificity. Tumor cells could be visualized from the macroscopic to single cell level with contrast ratios as high as 1000: 1 compared to normal brain tissue. CONCLUSIONS/SIGNIFICANCE: The ability of the targeted probes to clearly distinguish tumor cells in low-grade tumor biopsies, where no enhanced MRI image was obtained, demonstrates the great potential of the method. We propose that future application of specifically targeted fluorescent particles during surgery could allow intraoperative guidance for the removal of residual tumor cells from the resection cavity and thus increase patient survival.

  10. High baseline activity in inferior temporal cortex improves neural and behavioral discriminability during visual categorization

    Directory of Open Access Journals (Sweden)

    Nazli eEmadi

    2014-11-01

    Full Text Available Spontaneous firing is a ubiquitous property of neural activity in the brain. Recent literature suggests that this baseline activity plays a key role in perception. However, it is not known how the baseline activity contributes to neural coding and behavior. Here, by recording from the single neurons in the inferior temporal cortex of monkeys performing a visual categorization task, we thoroughly explored the relationship between baseline activity, the evoked response, and behavior. Specifically we found that a low-frequency (< 8 Hz oscillation in the spike train, prior and phase-locked to the stimulus onset, was correlated with increased gamma power and neuronal baseline activity. This enhancement of the baseline activity was then followed by an increase in the neural selectivity and the response reliability and eventually a higher behavioral performance.

  11. A method to improve visual similarity of breast masses for an interactive computer-aided diagnosis environment

    International Nuclear Information System (INIS)

    The purpose of this study was to develop and test a method for selecting 'visually similar' regions of interest depicting breast masses from a reference library to be used in an interactive computer-aided diagnosis (CAD) environment. A reference library including 1000 malignant mass regions and 2000 benign and CAD-generated false-positive regions was established. When a suspicious mass region is identified, the scheme segments the region and searches for similar regions from the reference library using a multifeature based k-nearest neighbor (KNN) algorithm. To improve selection of reference images, we added an interactive step. All actual masses in the reference library were subjectively rated on a scale from 1 to 9 as to their 'visual margins speculations'. When an observer identifies a suspected mass region during a case interpretation he/she first rates the margins and the computerized search is then limited only to regions rated as having similar levels of spiculation (within ±1 scale difference). In an observer preference study including 85 test regions, two sets of the six 'similar' reference regions selected by the KNN with and without the interactive step were displayed side by side with each test region. Four radiologists and five nonclinician observers selected the more appropriate ('similar') reference set in a two alternative forced choice preference experiment. All four radiologists and five nonclinician observers preferred the sets of regions selected by the interactive method with an average frequency of 76.8% and 74.6%, respectively. The overall preference for the interactive method was highly significant (p<0.001). The study demonstrated that a simple interactive approach that includes subjectively perceived ratings of one feature alone namely, a rating of margin 'spiculation', could substantially improve the selection of 'visually similar' reference images

  12. Live-cell visualization of excitation energy dynamics in chloroplast thylakoid structures.

    Science.gov (United States)

    Iwai, Masakazu; Yokono, Makio; Kurokawa, Kazuo; Ichihara, Akira; Nakano, Akihiko

    2016-01-01

    The intricate molecular processes underlying photosynthesis have long been studied using various analytic approaches. However, the three-dimensional (3D) dynamics of such photosynthetic processes remain unexplored due to technological limitations related to investigating intraorganellar mechanisms in vivo. By developing a system for high-speed 3D laser scanning confocal microscopy combined with high-sensitivity multiple-channel detection, we visualized excitation energy dynamics in thylakoid structures within chloroplasts of live Physcomitrella patens cells. Two distinct thylakoid structures in the chloroplast, namely the grana and stroma lamellae, were visualized three-dimensionally in live cells. The simultaneous detection of the shorter (than ~670 nm) and longer (than ~680 nm) wavelength regions of chlorophyll (Chl) fluorescence reveals different spatial characteristics-irregular and vertical structures, respectively. Spectroscopic analyses showed that the shorter and longer wavelength regions of Chl fluorescence are affected more by free light-harvesting antenna proteins and photosystem II supercomplexes, respectively. The high-speed 3D time-lapse imaging of the shorter and longer wavelength regions also reveals different structural dynamics-rapid and slow movements within 1.5 seconds, respectively. Such structural dynamics of the two wavelength regions of Chl fluorescence would indicate excitation energy dynamics between light-harvesting antenna proteins and photosystems, reflecting the energetically active nature of photosynthetic proteins in thylakoid membranes. PMID:27416900

  13. Improved Cell Culture Method for Growing Contracting Skeletal Muscle Models

    Science.gov (United States)

    Marquette, Michele L.; Sognier, Marguerite A.

    2013-01-01

    An improved method for culturing immature muscle cells (myoblasts) into a mature skeletal muscle overcomes some of the notable limitations of prior culture methods. The development of the method is a major advance in tissue engineering in that, for the first time, a cell-based model spontaneously fuses and differentiates into masses of highly aligned, contracting myotubes. This method enables (1) the construction of improved two-dimensional (monolayer) skeletal muscle test beds; (2) development of contracting three-dimensional tissue models; and (3) improved transplantable tissues for biomedical and regenerative medicine applications. With adaptation, this method also offers potential application for production of other tissue types (i.e., bone and cardiac) from corresponding precursor cells.

  14. Postnatal development of layer III pyramidal cells in the primary visual, inferior temporal, and prefrontal cortices of the marmoset

    OpenAIRE

    Hirosato eAoi; Tomofumi eOga; Tetsuya eSasaki; Ichiro eFujita; Noritaka eIchinohe

    2013-01-01

    Abnormalities in the processes of the generation and/or pruning of dendritic spines have been implicated in several mental disorders including autism and schizophrenia. We have chosen to examine the common marmoset (Callithrix jacchus) as a primate model to explore the processes. As a first step, we studied the postnatal development of basal dendritic trees and spines of layer-III pyramidal cells in the primary visual sensory cortex (V1), a visual association cortex (inferior temporal area, T...

  15. An improved simulated annealing algorithm for standard cell placement

    Science.gov (United States)

    Jones, Mark; Banerjee, Prithviraj

    1988-01-01

    Simulated annealing is a general purpose Monte Carlo optimization technique that was applied to the problem of placing standard logic cells in a VLSI ship so that the total interconnection wire length is minimized. An improved standard cell placement algorithm that takes advantage of the performance enhancements that appear to come from parallelizing the uniprocessor simulated annealing algorithm is presented. An outline of this algorithm is given.

  16. The Design and Development of a User-Controlled Visual Aid for Improving Students' Understanding in Introductory Statistics

    Science.gov (United States)

    Vaughn, Brandon K.; Wang, Pei-Yu

    2009-01-01

    The use of visual aids is expected to have a positive effect on students' learning. However, not all visual aids work equally well. A recent meta-analytic research which examined 42 studies has found that the use of animated visuals does not facilitate learning (Anglin, Vaez & Cunnincham, 2004). The failure of visual aids can be attributed to…

  17. Continued SOFC cell and stack technology and improved production methods

    Energy Technology Data Exchange (ETDEWEB)

    Wandel, M.; Brodersen, K.; Phair, J. (and others)

    2009-05-15

    Within this project significant results are obtained on a number of very diverse areas ranging from development of cell production, metallic creep in interconnect to assembling and test of stacks with foot print larger than 500 cm2. Out of 38 milestones 28 have been fulfilled and 10 have been partly fulfilled. This project has focused on three main areas: 1) The continued cell development and optimization of manufacturing processes aiming at production of large foot-print cells, improving cell performance and development environmentally more benign production methods. 2) Stack technology - especially stacks with large foot print and improving the stack design with respect to flow geometry and gas leakages. 3) Development of stack components with emphasis on sealing (for 2G as well as 3G), interconnect (coat, architecture and creep) and test development. Production of cells with a foot print larger than 500 cm2 is very difficult due to the brittleness of the cells and great effort has been put into this topic. Eight cells were successfully produced making it possible to assemble and test a real stack thereby giving valuable results on the prospects of stacks with large foot print. However, the yield rate is very low and a significant development to increase this yield lies ahead. Several lessons were learned on the stack level regarding 'large foot print' stacks. Modelling studies showed that the width of the cell primarily is limited by production and handling of the cell whereas the length (in the flow direction) is limited by e.g. pressure drop and necessary manifolding. The optimal cell size in the flow direction was calculated to be between approx20 cm and < 30 cm. From an economical point of view the production yield is crucial and stacks with large foot print cell area are only feasible if the cell production yield is significantly enhanced. Co-casting has been pursued as a production technique due to the possibilities in large scale production

  18. Improved Membrane Materials for PEM Fuel Cell Application

    Energy Technology Data Exchange (ETDEWEB)

    Kenneth A. Mauritz; Robert B. Moore

    2008-06-30

    The overall goal of this project is to collect and integrate critical structure/property information in order to develop methods that lead to significant improvements in the durability and performance of polymer electrolyte membrane fuel cell (PEMFC) materials. This project is focused on the fundamental improvement of PEMFC membrane materials with respect to chemical, mechanical and morphological durability as well as the development of new inorganically-modified membranes.

  19. Visualization of the Nucleolus in Living Cells with Cell-Penetrating Fluorescent Peptides.

    Science.gov (United States)

    Martin, Robert M; Herce, Henry D; Ludwig, Anne K; Cardoso, M Cristina

    2016-01-01

    The nucleolus is the hallmark of nuclear compartmentalization and has been shown to exert multiple roles in cellular metabolism besides its main function as the place of ribosomal RNA synthesis and assembly of ribosomes. The nucleolus plays also a major role in nuclear organization as the largest compartment within the nucleus. The prominent structure of the nucleolus can be detected using contrast light microscopy providing an approximate localization of the nucleolus, but this approach does not allow to determine accurately the three-dimensional structure of the nucleolus in cells and tissues. Immunofluorescence staining with antibodies specific to nucleolar proteins albeit very useful is time consuming, normally antibodies recognize their epitopes only within a small range of species and is applicable only in fixed cells. Here, we present a simple method to selectively and accurately label this ubiquitous subnuclear compartment in living cells of a large range of species using a fluorescently labeled cell-penetrating peptide. PMID:27576711

  20. Using Visual Aids to Improve Communication of Risks about Health: A Review

    Directory of Open Access Journals (Sweden)

    Rocio Garcia-Retamero

    2012-01-01

    Full Text Available Recent research has shown that patients frequently experience difficulties understanding health-relevant numerical concepts. A prominent example is denominator neglect, or the tendency to pay too much attention to numerators in ratios (e.g., number of treated patients who died with insufficient attention to denominators (e.g., overall number of treated patients. Denominator neglect can lead to inaccurate assessments of treatment risk reduction and thus can have important consequences for decisions about health. Here, we reviewed a series of studies investigating (1 different factors that can influence patients’ susceptibility to denominator neglect in medical decision making—including numerical or language-related abilities; (2 the extent to which denominator neglect can be attenuated by using visual aids; and (3 a factor that moderates the effectiveness of such aids (i.e., graph literacy. The review spans probabilistic national U.S. and German samples, as well as immigrant (i.e., Polish people living in the United Kingdom and undergraduate samples in Spain. Theoretical and prescriptive implications are discussed.

  1. Dynamic focus optical coherence tomography: feasibility for improved basal cell carcinoma investigation

    Science.gov (United States)

    Nasiri-Avanaki, M. R.; Aber, Ahmed; Hojjatoleslami, S. A.; Sira, Mano; Schofield, John B.; Jones, Carole; Podoleanu, A. Gh.

    2012-03-01

    Basal cell carcinoma (BCC) is the most common form of skin cancer. To improve the diagnostic accuracy, additional non-invasive methods of making a preliminary diagnosis have been sought. We have implemented an En-Face optical coherence tomography (OCT) for this study in which the dynamic focus was integrated into it. With the dynamic focus scheme, the coherence gate moves synchronously with the peak of confocal gate determined by the confocal interface optics. The transversal resolution is then conserved throughout the depth range and an enhanced signal is returned from all depths. The Basal Cell Carcinoma specimens were obtained from the eyelid a patient. The specimens under went analysis by DF-OCT imaging. We searched for remarkable features that were visualized by OCT and compared these findings with features presented in the histology slices.

  2. Targeting Human Dendritic Cell Subsets for Improved Vaccines

    Science.gov (United States)

    Ueno, Hideki; Klechevsky, Eynav; Schmitt, Nathalie; Ni, Ling; Flamar, Anne-Laure; Zurawski, Sandra; Zurawski, Gerard; Palucka, Karolina; Banchereau, Jacques; Oh, SangKon

    2011-01-01

    Summary Dendritic cells (DCs) were discovered in 1973 by Ralph Steinman as a previously undefined cell type in the mouse spleen and are now recognized as a group of related cell populations that induce and regulate adaptive immune responses. Studies of the past decade show that, both in mice and humans, DCs are composed of subsets that differ in their localization, phenotype, and functions. These progresses in our understanding of DC biology provide a new framework for improving human health. In this review, we discuss human DC subsets in the context of their medical applications, with a particular focus on DC targeting. PMID:21277223

  3. Can retinal ganglion cell dipoles seed iso-orientation domains in the visual cortex?

    Directory of Open Access Journals (Sweden)

    Manuel Schottdorf

    Full Text Available It has been argued that the emergence of roughly periodic orientation preference maps (OPMs in the primary visual cortex (V1 of carnivores and primates can be explained by a so-called statistical connectivity model. This model assumes that input to V1 neurons is dominated by feed-forward projections originating from a small set of retinal ganglion cells (RGCs. The typical spacing between adjacent cortical orientation columns preferring the same orientation then arises via Moiré-Interference between hexagonal ON/OFF RGC mosaics. While this Moiré-Interference critically depends on long-range hexagonal order within the RGC mosaics, a recent statistical analysis of RGC receptive field positions found no evidence for such long-range positional order. Hexagonal order may be only one of several ways to obtain spatially repetitive OPMs in the statistical connectivity model. Here, we investigate a more general requirement on the spatial structure of RGC mosaics that can seed the emergence of spatially repetitive cortical OPMs, namely that angular correlations between so-called RGC dipoles exhibit a spatial structure similar to that of OPM autocorrelation functions. Both in cat beta cell mosaics as well as primate parasol receptive field mosaics we find that RGC dipole angles are spatially uncorrelated. To help assess the level of these correlations, we introduce a novel point process that generates mosaics with realistic nearest neighbor statistics and a tunable degree of spatial correlations of dipole angles. Using this process, we show that given the size of available data sets, the presence of even weak angular correlations in the data is very unlikely. We conclude that the layout of ON/OFF ganglion cell mosaics lacks the spatial structure necessary to seed iso-orientation domains in the primary visual cortex.

  4. IMHEX fuel cell repeat component manufacturing continuous improvement accomplishments

    Energy Technology Data Exchange (ETDEWEB)

    Jakaitis, L.A.; Petraglia, V.J.; Bryson, E.S. [M-C Power Corp., Burr Ridge, IL (United States)] [and others

    1996-12-31

    M-C Power is taking a power generation technology that has been proven in the laboratory and is making it a commercially competitive product. There are many areas in which this technology required scale up and refinement to reach the market entry goals for the IMHEX{reg_sign} molten carbonate fuel cell power plant. One of the primary areas that needed to be addressed was the manufacturing of the fuel cell stack. Up to this point, the fuel cell stack and associated components were virtually hand made for each system to be tested. M-C Power has now continuously manufactured the repeat components for three 250 kW stacks. M-C Power`s manufacturing strategy integrated both evolutionary and revolutionary improvements into its comprehensive commercialization effort. M-C Power`s objectives were to analyze and continuously improve stack component manufacturing and assembly techniques consistent with established specifications and commercial scale production requirements. Evolutionary improvements are those which naturally occur as the production rates are increased and experience is gained. Examples of evolutionary (learning curve) improvements included reducing scrap rates and decreasing raw material costs by buying in large quantities. Revolutionary improvements result in significant design and process changes to meet cost and performance requirements of the market entry system. Revolutionary changes often involve identifying new methods and developing designs to accommodate the new process. Based upon our accomplishments, M-C Power was able to reduce the cost of continuously manufactured fuel cell repeat components from the first to third 250 kW stack by 63%. This paper documents the continuous improvement accomplishments realized by M-C Power during IMHEX{reg_sign} fuel cell repeat component manufacturing.

  5. Fluorescently labeled collagen binding proteins allow specific visualization of collagen in tissues and live cell culture.

    Science.gov (United States)

    Krahn, Katy Nash; Bouten, Carlijn V C; van Tuijl, Sjoerd; van Zandvoort, Marc A M J; Merkx, Maarten

    2006-03-15

    Visualization of the formation and orientation of collagen fibers in tissue engineering experiments is crucial for understanding the factors that determine the mechanical properties of tissues. In this study, collagen-specific fluorescent probes were developed using a new approach that takes advantage of the inherent specificity of collagen binding protein domains present in bacterial adhesion proteins (CNA35) and integrins (GST-alpha1I). Both collagen binding domains were obtained as fusion proteins from an Escherichia coli expression system and fluorescently labeled using either amine-reactive succinimide (CNA35) or cysteine-reactive maleimide (GST-alpha1I) dyes. Solid-phase binding assays showed that both protein-based probes are much more specific than dichlorotriazinyl aminofluorescein (DTAF), a fluorescent dye that is currently used to track collagen formation in tissue engineering experiments. The CNA35 probe showed a higher affinity for human collagen type I than did the GST-alpha1I probe (apparent K(d) values of 0.5 and 50 microM, respectively) and showed very little cross-reactivity with noncollagenous extracellular matrix proteins. The CNA35 probe was also superior to both GST-alpha1I and DTAF in visualizing the formation of collagen fibers around live human venous saphena cells. Immunohistological experiments on rat tissue showed colocalization of the CNA35 probe with collagen type I and type III antibodies. The fluorescent probes described here have important advantages over existing methods for visualization of collagen, in particular for monitoring the formation of collagen in live tissue cultures over prolonged time periods. PMID:16476406

  6. Combining [(11)C]-AnxA5 PET Imaging with Serum Biomarkers for Improved Detection in Live Mice of Modest Cell Death in Human Solid Tumor Xenografts

    OpenAIRE

    Q. Cheng; Lu, L; Grafström, J; Olofsson, MH; Thorell, JO; Samén, E; K. Johansson; Ahlzén, HS; Stone-Elander, S; Linder, S; Arnér, Elias S.J.

    2012-01-01

    BACKGROUND: In vivo imaging using Annexin A5-based radioligands is a powerful technique for visualizing massive cell death, but has been less successful in monitoring the modest cell death typically seen in solid tumors after chemotherapy. Here we combined dynamic positron emission tomography (PET) imaging using Annexin A5 with a serum-based apoptosis marker, for improved sensitivity and specificity in assessment of chemotherapy-induced cell death in a solid tumor model. METHODOLOGY/...

  7. Visualization of Polarized Membrane Type 1 Matrix Metalloproteinase Activity in Live Cells by Fluorescence Resonance Energy Transfer Imaging*S⃞

    OpenAIRE

    Ouyang, Mingxing; Lu, Shaoying; Li, Xiao-Yan; Xu, Jing; Seong, Jihye; Giepmans, Ben N. G.; Shyy, John Y.-J.; Weiss, Stephen J.; Wang, Yingxiao

    2008-01-01

    Membrane type 1 matrix metalloproteinase (MT1-MMP) plays a critical role in cancer cell biology by proteolytically remodeling the extracellular matrix. Utilizing fluorescence resonance energy transfer (FRET) imaging, we have developed a novel biosensor, with its sensing element anchoring at the extracellular surface of cell membrane, to visualize MT1-MMP activity dynamically in live cells with subcellular resolution. Epidermal growth factor (EGF) induced significant FR...

  8. Fabrication approaches for plasmon-improved photovoltaic cells

    DEFF Research Database (Denmark)

    Gritti, Claudia; Malureanu, Radu; Kardynal, B.;

    During this talk we will present various fabrication approaches to improve the performance of photovoltaic (PV) cells by using metallic nanoparticles in order to generate photocurrent below the bandgap. This effect is possible due to the generation of surface plasmon polaritons (SPPs) in optimized...

  9. Super-resolution imaging with Pontamine Fast Scarlet 4BS enables direct visualization of cellulose orientation and cell connection architecture in onion epidermis cells

    OpenAIRE

    Liesche, Johannes; Ziomkiewicz, Iwona; Schulz, Alexander

    2013-01-01

    BackgroundIn plants, a complex cell wall protects cells and defines their shape. Cellulose fibrils form a multilayered network inside the cell-wall matrix that plays a direct role in controlling cell expansion. Resolving the structure of this network will allow us to comprehend the relationship of cellulose fibril orientation and growth.The fluorescent dye Pontamine Fast Scarlet 4BS (PFS) was shown to stain cellulose with high specificity and could be used to visualize cellulose bundles in ce...

  10. Comparison of digital image analysis versus visual assessment to assess survivin expression as an independent predictor of survival for patients with clear cell renal cell carcinoma✩

    OpenAIRE

    Parker, Alexander S.; Lohse, Christine M.; Leibovich, Bradley C.; Cheville, John C; Sheinin, Yuri M.; Kwon, Eugene D.

    2008-01-01

    We previously used quantitative digital image analysis to report that high immunohistochemical tumor expression levels of survivin independently predict poor outcome among patients with clear cell renal cell carcinoma. However, given the cumbersome and costly nature of digital image analysis, we evaluated simple visual assessment as an alternative to digital image analysis for assessing survivin as a predictor of clear cell renal cell carcinoma patient outcomes. We identified 310 patients tre...

  11. Improvement of distension and mural visualization of bowel loops using neutral oral contrasts in abdominal computed tomography

    Institute of Scientific and Technical Information of China (English)

    Jahanbakhsh; Hashemi; Yasmin; Davoudi; Mina; Taghavi; Masoud; Pezeshki; Rad; Amien; Mahajeri; Moghadam

    2014-01-01

    AIM: To assess and compare the image quality of 4% sorbitol and diluted iodine 2%(positive oral contrast agent) in abdomino-pelvic multi-detector computed tomography.METHODS: Two-hundred patients, referred to the Radiology Department of a central educational hospital for multi-detector row abdominal-pelvic computed tomography, were randomly divided into two groups: the first group received 1500 m L of 4% sorbitol solution as a neutral contrast agent, while in the second group 1500 m L of meglumin solution as a positive contrast agent was administered in a one-way randomized prospective study. The results were independently reviewed by two radiologists. Luminal distension and mural thickness and mucosal enhancement were compared between the two groups. Statistical analysis of the results was performed by Statistical Package for the Social Sciences software version 16 and the Mann-Whitney test at a confidence level of 95%. RESULTS: Use of neutral oral contrast agent significantly improved visualization of the small bowel wall thickness and mural appearance in comparison with administration of positive contrast agent(P < 0.01). In patients who received sorbitol, the small bowel showed better distention compared with those who received iodine solution as a positive contrast agent(P < 0.05). CONCLUSION: The results of the study demonstrated that oral administration of sorbitol solution allows better luminal distention and visualization of mural features than iodine solution as a positive contrast agent.

  12. Attention Cueing and Activity Equally Reduce False Alarm Rate in Visual-Auditory Associative Learning through Improving Memory

    Science.gov (United States)

    Haghgoo, Hojjat Allah; Azizi, Solmaz; Nili Ahmadabadi, Majid

    2016-01-01

    In our daily life, we continually exploit already learned multisensory associations and form new ones when facing novel situations. Improving our associative learning results in higher cognitive capabilities. We experimentally and computationally studied the learning performance of healthy subjects in a visual-auditory sensory associative learning task across active learning, attention cueing learning, and passive learning modes. According to our results, the learning mode had no significant effect on learning association of congruent pairs. In addition, subjects’ performance in learning congruent samples was not correlated with their vigilance score. Nevertheless, vigilance score was significantly correlated with the learning performance of the non-congruent pairs. Moreover, in the last block of the passive learning mode, subjects significantly made more mistakes in taking non-congruent pairs as associated and consciously reported lower confidence. These results indicate that attention and activity equally enhanced visual-auditory associative learning for non-congruent pairs, while false alarm rate in the passive learning mode did not decrease after the second block. We investigated the cause of higher false alarm rate in the passive learning mode by using a computational model, composed of a reinforcement learning module and a memory-decay module. The results suggest that the higher rate of memory decay is the source of making more mistakes and reporting lower confidence in non-congruent pairs in the passive learning mode. PMID:27314235

  13. Improvement of Pyroelectric Cells for Thermal Energy Harvesting

    Directory of Open Access Journals (Sweden)

    Jing-Chih Ciou

    2012-01-01

    Full Text Available This study proposes trenching piezoelectric (PZT material in a thicker PZT pyroelectric cell to improve the temperature variation rate to enhance the efficiency of thermal energy-harvesting conversion by pyroelectricity. A thicker pyroelectric cell is beneficial in generating electricity pyroelectrically, but it hinders rapid temperature variations. Therefore, the PZT sheet was fabricated to produce deeper trenches to cause lateral temperature gradients induced by the trenched electrode, enhancing the temperature variation rate under homogeneous heat irradiation. When the trenched electrode type with an electrode width of 200 μm and a cutting depth of 150 μm was used to fabricate a PZT pyroelectric cell with a 200 μm thick PZT sheet, the temperature variation rate was improved by about 55%. Therefore, the trenched electrode design did indeed enhance the temperature variation rate and the efficiency of pyroelectric energy converters.

  14. Improvement of pyroelectric cells for thermal energy harvesting.

    Science.gov (United States)

    Hsiao, Chun-Ching; Siao, An-Shen; Ciou, Jing-Chih

    2012-01-01

    This study proposes trenching piezoelectric (PZT) material in a thicker PZT pyroelectric cell to improve the temperature variation rate to enhance the efficiency of thermal energy-harvesting conversion by pyroelectricity. A thicker pyroelectric cell is beneficial in generating electricity pyroelectrically, but it hinders rapid temperature variations. Therefore, the PZT sheet was fabricated to produce deeper trenches to cause lateral temperature gradients induced by the trenched electrode, enhancing the temperature variation rate under homogeneous heat irradiation. When the trenched electrode type with an electrode width of 200 μm and a cutting depth of 150 μm was used to fabricate a PZT pyroelectric cell with a 200 μm thick PZT sheet, the temperature variation rate was improved by about 55%. Therefore, the trenched electrode design did indeed enhance the temperature variation rate and the efficiency of pyroelectric energy converters. PMID:22368484

  15. Efficiency improvements in GaAs-on-Si solar cells

    Science.gov (United States)

    Vernon, S. M.; Tobin, S. P.; Haven, V. E.; Bajgar, C.; Dixon, T. M.

    The thermal cycle growth (TCG) method is shown to be effective in improving GaAs/Si photovoltaic performance. Transmission electron microscope studies revealed that dislocation densities were reduced by approximately an order of magnitude and minority-carrier lifetimes increased by more than a factor of two. The efficiency of GaAs-on-Si cells were increased from 11.2 percent to 17.6 percent (one-sun) and from 13.9 percent to 18.5 percent (concentrated light) by use of the TCG technique. Improvements in basic GaAs cell growth and processing technology were also responsible for a portion of these increases, as GaAs/GaAs control cell efficiencies climbed from 21.3 to 24.3 percent over the span of these experiments.

  16. Retinal ganglion cell projections to the hamster suprachiasmatic nucleus, intergeniculate leaflet, and visual midbrain: bifurcation and melanopsin immunoreactivity

    Science.gov (United States)

    Morin, Lawrence P.; Blanchard, Jane H.; Provencio, Ignacio

    2003-01-01

    The circadian clock in the suprachiasmatic nucleus (SCN) receives direct retinal input via the retinohypothalamic tract (RHT), and the retinal ganglion cells contributing to this projection may be specialized with respect to direct regulation of the circadian clock. However, some ganglion cells forming the RHT bifurcate, sending axon collaterals to the intergeniculate leaflet (IGL) through which light has secondary access to the circadian clock. The present studies provide a more extensive examination of ganglion cell bifurcation and evaluate whether ganglion cells projecting to several subcortical visual nuclei contain melanopsin, a putative ganglion cell photopigment. The results showed that retinal ganglion cells projecting to the SCN send collaterals to the IGL, olivary pretectal nucleus, and superior colliculus, among other places. Melanopsin-immunoreactive (IR) ganglion cells are present in the hamster retina, and some of these cells project to the SCN, IGL, olivary pretectal nucleus, or superior colliculus. Triple-label analysis showed that melanopsin-IR cells bifurcate and project bilaterally to each SCN, but not to the other visual nuclei evaluated. The melanopsin-IR cells have photoreceptive characteristics optimal for circadian rhythm regulation. However, the presence of moderately widespread bifurcation among ganglion cells projecting to the SCN, and projection by melanopsin-IR cells to locations distinct from the SCN and without known rhythm function, suggest that this ganglion cell type is generalized, rather than specialized, with respect to the conveyance of photic information to the brain. Copyright 2003 Wiley-Liss, Inc.

  17. Diode Laser 810 Nm as a Potential Treatment to Improve Visual Function in Nonarteritic Anterior Ischemic Optic Neuropathy (NAION

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Heidari

    2011-01-01

    Full Text Available Nonarteritic anterior ischemic optic neuropathy (NAION is one of the most widespread visually disabling diseases in the middle-aged and elderly population. The optic nerve damage appears to result from a perfusion insufficiency in the short posterior ciliary arteries leading to infarction of the retrolaminar portion of the optic disc. Induced Heat shock protein (Hsp is known to have neuroprotective effects against ischemic injury of the central nervous system in mammals. Transpupillary thermotherapy (TTT application to the optic nerve head induces Hsp70 expression. We hypothesize that Transpupillary thermotherapy (TTT could be a novel method for improving and preserving the function of the optic nerve fibers in the eye with NAION. An 810-nm diode laser beam is focused to the center of the optic nerve head to induce Hsp. Controlled prospective and randomized clinical trial is necessary to confirm conclusively the effectiveness of this method.

  18. Quantitative operando visualization of the energy band depth profile in solar cells.

    Science.gov (United States)

    Chen, Qi; Mao, Lin; Li, Yaowen; Kong, Tao; Wu, Na; Ma, Changqi; Bai, Sai; Jin, Yizheng; Wu, Dan; Lu, Wei; Wang, Bing; Chen, Liwei

    2015-01-01

    The energy band alignment in solar cell devices is critically important because it largely governs elementary photovoltaic processes, such as the generation, separation, transport, recombination and collection of charge carriers. Despite the expenditure of considerable effort, the measurement of energy band depth profiles across multiple layers has been extremely challenging, especially for operando devices. Here we present direct visualization of the surface potential depth profile over the cross-sections of operando organic photovoltaic devices using scanning Kelvin probe microscopy. The convolution effect due to finite tip size and cantilever beam crosstalk has previously prohibited quantitative interpretation of scanning Kelvin probe microscopy-measured surface potential depth profiles. We develop a bias voltage-compensation method to address this critical problem and obtain quantitatively accurate measurements of the open-circuit voltage, built-in potential and electrode potential difference. PMID:26166580

  19. Quantitative operando visualization of the energy band depth profile in solar cells

    Science.gov (United States)

    Chen, Qi; Mao, Lin; Li, Yaowen; Kong, Tao; Wu, Na; Ma, Changqi; Bai, Sai; Jin, Yizheng; Wu, Dan; Lu, Wei; Wang, Bing; Chen, Liwei

    2015-07-01

    The energy band alignment in solar cell devices is critically important because it largely governs elementary photovoltaic processes, such as the generation, separation, transport, recombination and collection of charge carriers. Despite the expenditure of considerable effort, the measurement of energy band depth profiles across multiple layers has been extremely challenging, especially for operando devices. Here we present direct visualization of the surface potential depth profile over the cross-sections of operando organic photovoltaic devices using scanning Kelvin probe microscopy. The convolution effect due to finite tip size and cantilever beam crosstalk has previously prohibited quantitative interpretation of scanning Kelvin probe microscopy-measured surface potential depth profiles. We develop a bias voltage-compensation method to address this critical problem and obtain quantitatively accurate measurements of the open-circuit voltage, built-in potential and electrode potential difference.

  20. Visualization of the Activity of Rac1 Small GTPase in a Cell

    International Nuclear Information System (INIS)

    Rho family G proteins including Rac regulate a variety of cellular functions, such as morphology, motility, and gene expression. Here we developed a fluorescence resonance energy transfer-based analysis in which we could monitor the activity of Rac1. To detect fluorescence resonance energy transfer, yellow fluorescent protein fused Rac1 and cyan fluorescent protein fused Cdc42-Rac1-interaction-binding domain of Pak1 protein were used as intermolecular probes of FRET. The fluorophores were separated with linear unmixing method. The fluorescence resonance energy transfer efficiency was measured by acceptor photobleaching assisted assay. With these methods, the Rac1 activity was visualized in a cell. The present findings indicate that this approach is sensitive enough to achieve results similar to those from ratiometric fluorescence resonance energy transfer analysis

  1. Contact lenses fitting teaching: learning improvement with monitor visualization of webcam video recordings

    Science.gov (United States)

    Gargallo, Ana; Arines, Justo

    2014-08-01

    We have adapted low cost webcams to the slit lamps objectives with the aim of improving contact lens fitting practice. With this solution we obtain good quality pictures and videos, we also recorded videos of eye examination, evaluation routines of contact lens fitting, and the final practice exam of our students. In addition, the video system increases the interactions between students because they could see what their colleagues are doing and take conscious of their mistakes, helping and correcting each others. We think that the proposed system is a low cost solution for supporting the training in contact lens fitting practice.

  2. Visualization of Assembly Intermediates and Budding Vacuoles of Singapore Grouper Iridovirus in Grouper Embryonic Cells

    Science.gov (United States)

    Liu, Yang; Tran, Bich Ngoc; Wang, Fan; Ounjai, Puey; Wu, Jinlu; Hew, Choy L.

    2016-01-01

    Iridovirid infection is associated with the catastrophic loss in aquaculture industry and the population decline of wild amphibians and reptiles, but none of the iridovirid life cycles have been well explored. Here, we report the detailed visualization of the life cycle of Singapore grouper iridovirus (SGIV) in grouper cells by cryo-electron microscopy (cryoEM) and tomography (ET). EM imaging revealed that SGIV viral particles have an outer capsid layer, and the interaction of this layer with cellular plasma membrane initiates viral entry. Subsequent viral replication leads to formation of a viral assembly site (VAS), where membranous structures emerge as precursors to recruit capsid proteins to form an intermediate, double-shell, crescent-shaped structure, which curves to form icosahedral capsids. Knockdown of the major capsid protein eliminates the formation of viral capsids. As capsid formation progresses, electron-dense materials known to be involved in DNA encapsidation accumulate within the capsid until it is fully occupied. Besides the well-known budding mechanism through the cell periphery, we demonstrate a novel budding process in which viral particles bud into a tubular-like structure within vacuoles. This budding process may denote a new strategy used by SGIV to disseminate viral particles into neighbor cells while evading host immune response. PMID:26727547

  3. visual bone marrow mesenchymal stem cell transplantation in the repair of spinal cord injury

    Institute of Scientific and Technical Information of China (English)

    Rui-ping Zhang; Cheng Xu; Yin Liu; Jian-ding Li; Jun Xie

    2015-01-01

    An important factor in improving functional recovery from spinal cord injury using stem cells is maximizing the number of transplanted cells at the lesion site. Here, we established a contusion model of spinal cord injury by dropping a weight onto the spinal cord at T7–8. Superparamagnet-ic iron oxide-labeled bone marrow mesenchymal stem cells were transplanted into the injured spinal cordvia the subarachnoid space. An outer magnetic ifeld was used to successfully guide the labeled cells to the lesion site. Prussian blue staining showed that more bone marrow mesen-chymal stem cells reached the lesion site in these rats than in those without magnetic guidance or superparamagnetic iron oxide labeling, and immunolfuorescence revealed a greater number of complete axons at the lesion site. Moreover, the Basso, Beattie and Bresnahan (BBB) locomotor rating scale scores were the highest in rats with superparamagnetic labeling and magnetic guid-ance. Our data conifrm that superparamagnetic iron oxide nanoparticles effectively label bone marrow mesenchymal stem cells and impart sufficient magnetism to respond to the external magnetic ifeld guides. More importantly, superparamagnetic iron oxide-labeled bone marrow mesenchymal stem cells can be dynamically and non-invasively trackedin vivo using magnetic resonance imaging. Superparamagnetic iron oxide labeling of bone marrow mesenchymal stem cells coupled with magnetic guidance offers a promising avenue for the clinical treatment of spinal cord injury.

  4. Visualizing Stable Features in Live Cell Nucleus for Evaluation of the Cell Global Motion Compensation

    Czech Academy of Sciences Publication Activity Database

    Sorokin, D.V.; Suchánková, Jana; Bártová, Eva; Matula, P.

    2014-01-01

    Roč. 60, č. 1 (2014), s. 45-49. ISSN 0015-5500 R&D Projects: GA ČR GBP302/12/G157; GA MŠk(CZ) EE2.3.30.0030 Institutional support: RVO:68081707 Keywords : cell global motion compensation * UV laser bleaching * image registration Subject RIV: BO - Biophysics Impact factor: 1.000, year: 2014

  5. Bradykinin preconditioning improves therapeutic potential of human endothelial progenitor cells in infarcted myocardium.

    Directory of Open Access Journals (Sweden)

    Zulong Sheng

    Full Text Available OBJECTIVES: Stem cell preconditioning (PC is a powerful approach in reducing cell death after transplantation. We hypothesized that PC human endothelial progenitor cells (hEPCs with bradykinin (BK enhance cell survival, inhibit apoptosis and repair the infarcted myocardium. METHODS: The hEPCs were preconditioned with or without BK. The hEPCs apoptosis induced by hypoxia along with serum deprivation was determined by annexin V-fluorescein isothiocyanate/ propidium iodide staining. Cleaved caspase-3, Akt and eNOS expressions were determined by Western blots. Caspase-3 activity and vascular endothelial growth factor (VEGF levels were assessed in hEPCs. For in vivo studies, the survival and cardiomyocytes apoptosis of transplanted hEPCs were assessed using 1,1'-dioctadecyl-3,3,3',3'-tetramethylindodi- carbocyanine,4-chlorobenzenesul-fonate salt labeled hEPCs and TUNEL staining. Infarct size and cardiac function were measured at 10 days after transplantation, and the survival of transplanted hEPCs were visualized using near-infrared optical imaging. RESULTS: In vitro data showed a marked suppression in cell apoptosis following BK PC. The PC reduced caspase-3 activation, increased the Akt, eNOS phosphorylation and VEGF levels. In vivo data in preconditioned group showed a robust cell anti-apoptosis, reduction in infarct size, and significant improvement in cardiac function. The effects of BK PC were abrogated by the B2 receptor antagonist HOE140, the Akt and eNOS antagonists LY294002 and L-NAME, respectively. CONCLUSIONS: The activation of B2 receptor-dependent PI3K/Akt/eNOS pathway by BK PC promotes VEGF secretion, hEPC survival and inhibits apoptosis, thereby improving cardiac function in vivo. The BK PC hEPC transplantation for stem cell-based therapies is a novel approach that has potential for clinical used.

  6. Restoration of visual function by expression of a light-gated mammalian ion channel in retinal ganglion cells or ON-bipolar cells

    OpenAIRE

    Gaub, Benjamin M.; Berry, Michael H.; Holt, Amy E.; Reiner, Andreas; Kienzler, Michael A; Dolgova, Natalia; Nikonov, Sergei; Aguirre, Gustavo D.; Beltran, William A.; Flannery, John G.; Isacoff, Ehud Y.

    2014-01-01

    We restored visual function to animal models of human blindness using a chemical compound that photosensitizes a mammalian ion channel. Virus-mediated expression of this light sensor in surviving retinal cells of blind mice restored light responses in vitro, reanimated innate light avoidance, and enabled learned visually guided behavior. The treatment also restored light responses to the retina of blind dogs. Patients that might benefit from this treatment would need to have intact ganglion c...

  7. Improved molecular toolkit for cAMP studies in live cells

    Directory of Open Access Journals (Sweden)

    Nicol Xavier

    2011-07-01

    Full Text Available Abstract Background cAMP is a ubiquitous second messenger involved in a wide spectrum of cellular processes including gene transcription, cell proliferation, and axonal pathfinding. Precise spatiotemporal manipulation and monitoring in live cells are crucial for investigation of cAMP-dependent pathways, but existing tools have several limitations. Findings We have improved the suitability of cAMP manipulating and monitoring tools for live cell imaging. We attached a red fluorescent tag to photoactivated adenylyl cyclase (PACα that enables reliable visualization of this optogenetic tool for cAMP manipulation in target cells independently of its photoactivation. We show that replacement of CFP/YFP FRET pair with GFP/mCherry in the Epac2-camps FRET probe reduces photobleaching and stabilizes the noise level during imaging experiments. Conclusions The modifications of PACα and Epac2-camps enhance these tools for in vitro cAMP studies in cultured living cells and in vivo studies in live animals in a wide range of experiments, and particularly for long term time-lapse imaging.

  8. Improvement of Method for Accessing Oracle Database Based on Visual Basic%基于Visual Basic访问Oracle数据库方法的改进

    Institute of Scientific and Technical Information of China (English)

    金艳; 徐涛

    2011-01-01

    针对Visual Basic在客户端远程访问Oracle数据库的问题,介绍了客户端无需安装Oracle客户端软件的连接方式,以简化Visual Basic客户端的复杂性,提高访问效率.重点介绍了ADO技术,设计了基于ADO技术建立VB和Oracle 数据库的连接方法.

  9. Radiation improves gene transfer into human ovarian carcinoma cells

    International Nuclear Information System (INIS)

    Purpose/Objective: Poor gene transfer is the major stumbling block to successful gene therapy today. We hypothesized that ionizing radiation might activate cellular recombination, and so improve stable gene transfer. During studies to quantitate radiation activated recombination, we also found that both plasmid and adenoviral vector transduction could be increased by irradiation. The studies presented here describe the effects of irradiation on gene transduction efficiency (both transient and stable transduction) in several human ovarian carcinoma lines, as a prelude to in vivo animal studies. Materials and Methods: The effect of irradiation on stable gene transfer efficiency was determined in human ovarian carcinoma cell lines (SKOV3, CAOV3 and PA1). Either irradiated or unirradiated cells were transfected with pRSVZ plasmid (containing a LacZ expression cassette) in either the supercoiled and linearized (XmnI) forms and β-galactosidase expression followed with time. Transfection efficiency was measured by flow cytometry following FDG staining at 0, 48, and 96 hours after irradiation. FDG is converted to a fluorescent metabolite by LacZ, and thus reflects the transfection efficiency of the LacZ containing vector. Vector quantitation was also performed by southern hybridization. Stable transduction efficiency was measured 14 -35 days after irradiation. Optimization of the time of irradiation with respect to transfection was performed. Since cells demonstrated increased stable recombination for as long as 96 hours after irradiation, continuous low dose rate and multiple radiation fractions were also tested. These experiments were repeated using the Ad5CMVlacZ. Dividing cells were exposed to Ad5CMVlacZ at an MOI of 0.1,1,5,10 and 100 to determine optimum transfection concentration. Transduction efficiency was again measured at various intervals to determine the radiation dose and interval post transfection which provides the maximum increase in transfection

  10. Contradiction Resolution of Competitive and Input Neurons to Improve Prediction and Visualization Performance

    Directory of Open Access Journals (Sweden)

    Ryotaro Kamimura

    2013-12-01

    Full Text Available In this paper, we propose a new type of informationtheoretic method to resolve the contradiction observed in competitive and input neurons. For competitive neurons, contradiction between self-evaluation (individuality and outer-evaluation (collectivity exists, which is reduced to realize the self-organizing maps. For input neurons, there exists contradiction between the use of many and few input neurons. We try to realize a situation where as many input neurons as possible are used, and at the same time, another where only a few input neurons are used. This contradictory situation can be resolved by viewing input neurons on different levels, namely, the individual and average level. We applied contradiction resolution to two data sets, namely, the Japanese short term economy survey (Tankan and Dollar-Yen exchange rates. In both data sets, we succeeded in improving the prediction performance. Many input neurons were used on average, but a few input neurons were only taken for each input pattern. In addition, connection weights were condensed into a small number of distinct groups for better prediction and interpretation performance.

  11. Three counting methods agree on cell and neuron number in chimpanzee primary visual cortex

    Directory of Open Access Journals (Sweden)

    Daniel James Miller

    2014-05-01

    Full Text Available Determining the cellular composition of specific brain regions is crucial to our understanding of the function of neurobiological systems. It is therefore useful to identify the extent to which different methods agree when estimating the same properties of brain circuitry. In this study, we estimated the number of neuronal and non-neuronal cells in the primary visual cortex (area 17 or V1 of both hemispheres from a single chimpanzee. Specifically, we processed samples distributed across V1 of the right hemisphere after cortex was flattened into a sheet using two variations of the isotropic fractionator cell and neuron counting method. We processed the left hemisphere as serial brain slices for stereological investigation. The goal of this study was to evaluate the agreement between these methods in the most direct manner possible by comparing estimates of cell density across one brain region of interest in a single individual. In our hands, these methods produced similar estimates of the total cellular population (approximately 1 billion as well as the number of neurons (approximately 675 million in chimpanzee V1, providing evidence that both techniques estimate the same parameters of interest. In addition, our results indicate the strengths of each distinct tissue preparation procedure, highlighting the importance of attention to anatomical detail. In summary, we found that the isotropic fractionator and the stereological optical fractionator produced concordant estimates of the cellular composition of V1, and that this result supports the conclusion that chimpanzees conform to the primate pattern of exceptionally high packing density in V1. Ultimately, our data suggest that investigators can optimize their experimental approach by using any of these counting methods to obtain reliable cell and neuron counts.

  12. Visualizing early splenic memory CD8+ T cells reactivation against intracellular bacteria in the mouse.

    Directory of Open Access Journals (Sweden)

    Marc Bajénoff

    Full Text Available Memory CD8(+ T cells represent an important effector arm of the immune response in maintaining long-lived protective immunity against viruses and some intracellular bacteria such as Listeria monocytogenes (L.m. Memory CD8(+ T cells are endowed with enhanced antimicrobial effector functions that perfectly tail them to rapidly eradicate invading pathogens. It is largely accepted that these functions are sufficient to explain how memory CD8(+ T cells can mediate rapid protection. However, it is important to point out that such improved functional features would be useless if memory cells were unable to rapidly find the pathogen loaded/infected cells within the infected organ. Growing evidences suggest that the anatomy of secondary lymphoid organs (SLOs fosters the cellular interactions required to initiate naive adaptive immune responses. However, very little is known on how the SLOs structures regulate memory immune responses. Using Listeria monocytogenes (L.m as a murine infection model and imaging techniques, we have investigated if and how the architecture of the spleen plays a role in the reactivation of memory CD8(+ T cells and the subsequent control of L.m growth. We observed that in the mouse, memory CD8(+ T cells start to control L.m burden 6 hours after the challenge infection. At this very early time point, L.m-specific and non-specific memory CD8(+ T cells localize in the splenic red pulp and form clusters around L.m infected cells while naïve CD8(+ T cells remain in the white pulp. Within these clusters that only last few hours, memory CD8(+ T produce inflammatory cytokines such as IFN-gamma and CCL3 nearby infected myeloid cells known to be crucial for L.m killing. Altogether, we describe how memory CD8(+ T cells trafficking properties and the splenic micro-anatomy conjugate to create a spatio-temporal window during which memory CD8(+ T cells provide a local response by secreting effector molecules around infected cells.

  13. Improved Single-Source Precursors for Solar-Cell Absorbers

    Science.gov (United States)

    Banger, Kulbinder K.; Harris, Jerry; Hepp, Aloysius

    2007-01-01

    Improved single-source precursor compounds have been invented for use in spray chemical vapor deposition (spray CVD) of chalcopyrite semiconductor absorber layers of thin-film cells. A "single-source precursor compound" is a single molecular compound that contains all the required elements, which when used under the spray CVD conditions, thermally decomposes to form CuIn(x)Ga(1-x)S(y)Se(2-y).

  14. Visualizing Nanoscale Distribution of Corrosion Cells by Open-Loop Electric Potential Microscopy.

    Science.gov (United States)

    Honbo, Kyoko; Ogata, Shoichiro; Kitagawa, Takuya; Okamoto, Takahiro; Kobayashi, Naritaka; Sugimoto, Itto; Shima, Shohei; Fukunaga, Akira; Takatoh, Chikako; Fukuma, Takeshi

    2016-02-23

    Corrosion is a traditional problem but still one of the most serious problems in industry. To reduce the huge economic loss caused by corrosion, tremendous effort has been made to understand, predict and prevent it. Corrosion phenomena are generally explained by the formation of corrosion cells at a metal-electrolyte interface. However, experimental verification of their nanoscale distribution has been a major challenge owing to the lack of a method able to visualize the local potential distribution in an electrolytic solution. In this study, we have investigated the nanoscale corrosion behavior of Cu fine wires and a duplex stainless steel by in situ imaging of local corrosion cells by open-loop electric potential microscopy (OL-EPM). For both materials, potential images obtained by OL-EPM show nanoscale contrasts, where areas of higher and lower potential correspond to anodic areas (i.e., corrosion sites) and cathodic areas, respectively. This imaging capability allows us to investigate the real-time transition of local corrosion sites even when surface structures show little change. This is particularly useful for investigating reactions under surface oxide layers or highly corrosion-resistant materials as demonstrated here. The proposed technique should be applicable to the study of other redox reactions on a battery electrode or a catalytic material. The results presented here open up such future applications of OL-EPM in nanoscale electrochemistry. PMID:26811989

  15. Visualization of NRAS RNA G-Quadruplex Structures in Cells with an Engineered Fluorogenic Hybridization Probe.

    Science.gov (United States)

    Chen, Shuo-Bin; Hu, Ming-Hao; Liu, Guo-Cai; Wang, Jin; Ou, Tian-Miao; Gu, Lian-Quan; Huang, Zhi-Shu; Tan, Jia-Heng

    2016-08-24

    The RNA G-quadruplex is an important secondary structure formed by guanine-rich RNA sequences. However, its folding studies have mainly been studied in vitro. Accurate identification of RNA G-quadruplex formation within a sequence of interest remains difficult in cells. Herein, and based on the guanine-rich sequence in the 5'-UTR of NRAS mRNA, we designed and synthesized the first G-quadruplex-triggered fluorogenic hybridization (GTFH) probe, ISCH-nras1, for the unique visualization of the G-quadruplexes that form in this region. ISCH-nras1 is made up of two parts: The first is a fluorescent light-up moiety specific to G-quadruplex structures, and the second is a DNA molecule that can hybridize with a sequence that is adjacent to the guanine-rich sequence in the NRAS mRNA 5'-UTR. Further evaluation studies indicated that ISCH-nras1 could directly and precisely detect the targeted NRAS RNA G-quadruplex structures, both in vitro and in cells. Thus, this GTFH probe was a useful tool for directly investigating the folding of G-quadruplex structures within an RNA of interest and represents a new direction for the design of smart RNA G-quadruplex probes. PMID:27508892

  16. Improved classification and visualization of healthy and pathological hard dental tissues by modeling specular reflections in NIR hyperspectral images

    Science.gov (United States)

    Usenik, Peter; Bürmen, Miran; Fidler, Aleš; Pernuš, Franjo; Likar, Boštjan

    2012-03-01

    Despite major improvements in dental healthcare and technology, dental caries remains one of the most prevalent chronic diseases of modern society. The initial stages of dental caries are characterized by demineralization of enamel crystals, commonly known as white spots, which are difficult to diagnose. Near-infrared (NIR) hyperspectral imaging is a new promising technique for early detection of demineralization which can classify healthy and pathological dental tissues. However, due to non-ideal illumination of the tooth surface the hyperspectral images can exhibit specular reflections, in particular around the edges and the ridges of the teeth. These reflections significantly affect the performance of automated classification and visualization methods. Cross polarized imaging setup can effectively remove the specular reflections, however is due to the complexity and other imaging setup limitations not always possible. In this paper, we propose an alternative approach based on modeling the specular reflections of hard dental tissues, which significantly improves the classification accuracy in the presence of specular reflections. The method was evaluated on five extracted human teeth with corresponding gold standard for 6 different healthy and pathological hard dental tissues including enamel, dentin, calculus, dentin caries, enamel caries and demineralized regions. Principal component analysis (PCA) was used for multivariate local modeling of healthy and pathological dental tissues. The classification was performed by employing multiple discriminant analysis. Based on the obtained results we believe the proposed method can be considered as an effective alternative to the complex cross polarized imaging setups.

  17. The role of cell adhesion molecules in visual circuit formation: from neurite outgrowth to maps and synaptic specificity.

    Science.gov (United States)

    Missaire, Mégane; Hindges, Robert

    2015-06-01

    The formation of visual circuitry is a multistep process that involves cell-cell interactions based on a range of molecular mechanisms. The correct implementation of individual events, including axon outgrowth and guidance, the formation of the topographic map, or the synaptic targeting of specific cellular subtypes, are prerequisites for a fully functional visual system that is able to appropriately process the information captured by the eyes. Cell adhesion molecules (CAMs) with their adhesive properties and their high functional diversity have been identified as key actors in several of these fundamental processes. Because of their growth-promoting properties, CAMs play an important role in neuritogenesis. Furthermore, they are necessary to control additional neurite development, regulating dendritic spacing and axon pathfinding. Finally, trans-synaptic interactions of CAMs ensure cell type-specific connectivity as a basis for the establishment of circuits processing distinct visual features. Recent discoveries implicating CAMs in novel mechanisms have led to a better general understanding of neural circuit formation, but also revealed an increasing complexity of their function. This review aims at describing the different levels of action for CAMs to shape neural connectivity, with a special focus on the visual system. PMID:25649254

  18. A "turn-on" silver nanocluster based fluorescent sensor for folate receptor detection and cancer cell imaging under visual analysis.

    Science.gov (United States)

    Jiang, Hong; Xu, Gang; Sun, Yimin; Zheng, Weiwei; Zhu, Xiangxiang; Wang, Baojuan; Zhang, Xiaojun; Wang, Guangfeng

    2015-07-28

    A novel terminal protection based label-free and "turn-on" fluorescent sensor for detection of folate receptors (FRs) and HeLa cells is developed by fluorescence resonance energy transfer (FRET) between single-walled carbon nanotubes (SWCNTs) and silver nanoclusters (AgNCs). Multilevel visual analysis (m(2)VA) was firstly proposed and applied in optimizing the experimental parameters. PMID:26108636

  19. Visualizing viral protein structures in cells using genetic probes for correlated light and electron microscopy.

    Science.gov (United States)

    Ou, Horng D; Deerinck, Thomas J; Bushong, Eric; Ellisman, Mark H; O'Shea, Clodagh C

    2015-11-15

    Structural studies of viral proteins most often use high-resolution techniques such as X-ray crystallography, nuclear magnetic resonance, single particle negative stain, or cryo-electron microscopy (EM) to reveal atomic interactions of soluble, homogeneous viral proteins or viral protein complexes. Once viral proteins or complexes are separated from their host's cellular environment, their natural in situ structure and details of how they interact with other cellular components may be lost. EM has been an invaluable tool in virology since its introduction in the late 1940's and subsequent application to cells in the 1950's. EM studies have expanded our knowledge of viral entry, viral replication, alteration of cellular components, and viral lysis. Most of these early studies were focused on conspicuous morphological cellular changes, because classic EM metal stains were designed to highlight classes of cellular structures rather than specific molecular structures. Much later, to identify viral proteins inducing specific structural configurations at the cellular level, immunostaining with a primary antibody followed by colloidal gold secondary antibody was employed to mark the location of specific viral proteins. This technique can suffer from artifacts in cellular ultrastructure due to compromises required to provide access to the immuno-reagents. Immunolocalization methods also require the generation of highly specific antibodies, which may not be available for every viral protein. Here we discuss new methods to visualize viral proteins and structures at high resolutions in situ using correlated light and electron microscopy (CLEM). We discuss the use of genetically encoded protein fusions that oxidize diaminobenzidine (DAB) into an osmiophilic polymer that can be visualized by EM. Detailed protocols for applying the genetically encoded photo-oxidizing protein MiniSOG to a viral protein, photo-oxidation of the fusion protein to yield DAB polymer staining, and

  20. Using surface imaging and visual coaching to improve the reproducibility and stability of deep-inspiration breath hold for left-breast-cancer radiotherapy

    International Nuclear Information System (INIS)

    Late cardiac complications may arise after left-breast radiation therapy. Deep-inspiration breath hold (DIBH) allows reduction of the irradiated heart volume at the same time as it reduces tumor bed motion and increases lung sparing. In the present study, we have evaluated the improvement in reproducibility and stability of the DIBH for left-breast-cancer treatment when visual coaching is provided with the aid of 3D video surface imaging and video goggles. Five left-breast-cancer patients and fifteen healthy volunteers were asked to perform a series of DIBHs without and with visual coaching. Reproducibility and stability of DIBH were measured for each individual with and without visual coaching. The average reproducibility and stability changed from 2.1 mm and 1.5 mm, respectively, without visual feedback to 0.5 mm and 0.7 mm with visual feedback, showing a significant statistical difference (p 2 mm) in reproducibility and stability were observed in 35% and 15% of the subjects, respectively. The average chest wall excursion of the DIBH with respect to the free breathing preceding the DIBH was found to be 11.3 mm. The reproducibility and stability of the DIBH improve significantly from the visual coaching provided to the patient, especially in those patients with poor reproducibility and stability.

  1. Using surface imaging and visual coaching to improve the reproducibility and stability of deep-inspiration breath hold for left-breast-cancer radiotherapy

    Science.gov (United States)

    Cerviño, Laura I.; Gupta, Sonia; Rose, Mary A.; Yashar, Catheryn; Jiang, Steve B.

    2009-11-01

    Late cardiac complications may arise after left-breast radiation therapy. Deep-inspiration breath hold (DIBH) allows reduction of the irradiated heart volume at the same time as it reduces tumor bed motion and increases lung sparing. In the present study, we have evaluated the improvement in reproducibility and stability of the DIBH for left-breast-cancer treatment when visual coaching is provided with the aid of 3D video surface imaging and video goggles. Five left-breast-cancer patients and fifteen healthy volunteers were asked to perform a series of DIBHs without and with visual coaching. Reproducibility and stability of DIBH were measured for each individual with and without visual coaching. The average reproducibility and stability changed from 2.1 mm and 1.5 mm, respectively, without visual feedback to 0.5 mm and 0.7 mm with visual feedback, showing a significant statistical difference (p 2 mm) in reproducibility and stability were observed in 35% and 15% of the subjects, respectively. The average chest wall excursion of the DIBH with respect to the free breathing preceding the DIBH was found to be 11.3 mm. The reproducibility and stability of the DIBH improve significantly from the visual coaching provided to the patient, especially in those patients with poor reproducibility and stability.

  2. Improved Electrodes and Electrolytes for Dye-Based Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Harry R. Allcock; Thomas E. Mallouk; Mark W. Horn

    2011-10-26

    The most important factor in limiting the stability of dye-sensitized solar cells is the use of volatile liquid solvents in the electrolytes, which causes leakage during extended operation especially at elevated temperatures. This, together with the necessary complex sealing of the cells, seriously hampers the industrial-scale manufacturing and commercialization feasibilities of DSSCs. The objective of this program was to bring about a significant improvement in the performance and longevity of dye-based solar cells leading to commercialization. This had been studied in two ways first through development of low volatility solid, gel or liquid electrolytes, second through design and fabrication of TiO2 sculptured thin film electrodes.

  3. Methods to Improve Adoptive T-Cell Therapy for Melanoma

    DEFF Research Database (Denmark)

    Donia, Marco; Hansen, Morten; Sendrup, Sarah L;

    2013-01-01

    Further development of adoptive T-cell therapy (ACT) with autologous tumor-infiltrating lymphocytes (TILs) has the potential to markedly change the long-term prognosis of patients with metastatic melanoma, and modifications of the original protocol that can improve its clinical efficacy are highly...... desirable. In this study, we demonstrated that a high in vitro tumor reactivity of infusion products was associated with clinical responses upon adoptive transfer. In addition, we systematically characterized the responses of a series of TIL products to relevant autologous short term-cultured melanoma cell...... lines from 12 patients. We provide evidence that antitumor reactivity of both CD8(+) and CD4(+) T cells could be enhanced in most TIL products by autologous melanoma sensitization by pretreatment with low-dose IFN-γ. IFN-γ selectively enhanced responses to tumor-associated antigens other than melanoma...

  4. Astaxanthin Improves Stem Cell Potency via an Increase in the Proliferation of Neural Progenitor Cells

    OpenAIRE

    Yung-Hyun Choi; Byung-Woo Kim; Woobong Choi; Jong-Hwan Lee; Wun-Jae Kim; Soo-Wan Nam; Jeong-Hwan Kim

    2010-01-01

    The present study was designed to investigate the question of whether or not astaxanthin improves stem cell potency via an increase in proliferation of neural progenitor cells (NPCs). Treatment with astaxanthin significantly increased proliferation and colony formation of NPCs. For identification of possible activated signaling molecules involved in active cell proliferation occurring after astaxanthin treatment, total protein levels of several proliferation-related proteins, and expression l...

  5. Cysteine modified polyaniline films improve biocompatibility for two cell lines

    International Nuclear Information System (INIS)

    This work focuses on one of the most exciting application areas of conjugated conducting polymers, which is cell culture and tissue engineering. To improve the biocompatibility of conducting polymers we present an easy method that involves the modification of the polymer backbone using L-cysteine. In this publication, we show the synthesis of polyaniline (PANI) films supported onto Polyethylene terephthalate (PET) films, and modified using cysteine (PANI-Cys) in order to generate a biocompatible substrate for cell culture. The PANI-Cys films are characterized by Fourier Transform infrared and UV–visible spectroscopy. The changes in the hydrophilicity of the polymer films after and before the modification were tested using contact angle measurements. After modification the contact angle changes from 86° ± 1 to 90° ± 1, suggesting a more hydrophylic surface. The adhesion properties of LM2 and HaCaT cell lines on the surface of PANI-Cys films in comparison with tissue culture plastic (TCP) are studied. The PANI-Cys film shows better biocompatibility than PANI film for both cell lines. The cell morphologies on the TCP and PANI-Cys film were examined by florescence and Atomic Force Microscopy (AFM). Microscopic observations show normal cellular behavior when PANI-Cys is used as a substrate of both cell lines (HaCaT and LM2) as when they are cultured on TCP. The ability of these PANI-Cys films to support cell attachment and growth indicates their potential use as biocompatible surfaces and in tissue engineering. - Highlights: • A new surface PANI-Cys was produced on films of polyethylene terephthalate. • The relationship between surface characteristics and biocompatibility is analyzed. • The PANI-Cys film presents good biocompatibility for two cell lines

  6. Cysteine modified polyaniline films improve biocompatibility for two cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Yslas, Edith I., E-mail: eyslas@exa.unrc.edu.ar [Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, Agencia Postal Nro3, X580BYA Río Cuarto (Argentina); Cavallo, Pablo; Acevedo, Diego F.; Barbero, César A. [Departamento de Química, Universidad Nacional de Río Cuarto, Agencia Postal Nro3, X580BYA Río Cuarto (Argentina); Rivarola, Viviana A. [Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, Agencia Postal Nro3, X580BYA Río Cuarto (Argentina)

    2015-06-01

    This work focuses on one of the most exciting application areas of conjugated conducting polymers, which is cell culture and tissue engineering. To improve the biocompatibility of conducting polymers we present an easy method that involves the modification of the polymer backbone using L-cysteine. In this publication, we show the synthesis of polyaniline (PANI) films supported onto Polyethylene terephthalate (PET) films, and modified using cysteine (PANI-Cys) in order to generate a biocompatible substrate for cell culture. The PANI-Cys films are characterized by Fourier Transform infrared and UV–visible spectroscopy. The changes in the hydrophilicity of the polymer films after and before the modification were tested using contact angle measurements. After modification the contact angle changes from 86° ± 1 to 90° ± 1, suggesting a more hydrophylic surface. The adhesion properties of LM2 and HaCaT cell lines on the surface of PANI-Cys films in comparison with tissue culture plastic (TCP) are studied. The PANI-Cys film shows better biocompatibility than PANI film for both cell lines. The cell morphologies on the TCP and PANI-Cys film were examined by florescence and Atomic Force Microscopy (AFM). Microscopic observations show normal cellular behavior when PANI-Cys is used as a substrate of both cell lines (HaCaT and LM2) as when they are cultured on TCP. The ability of these PANI-Cys films to support cell attachment and growth indicates their potential use as biocompatible surfaces and in tissue engineering. - Highlights: • A new surface PANI-Cys was produced on films of polyethylene terephthalate. • The relationship between surface characteristics and biocompatibility is analyzed. • The PANI-Cys film presents good biocompatibility for two cell lines.

  7. Improved Cathode Structure for a Direct Methanol Fuel Cell

    Science.gov (United States)

    Valdez, Thomas; Narayanan, Sekharipuram

    2005-01-01

    An improved cathode structure on a membrane/electrode assembly has been developed for a direct methanol fuel cell, in a continuing effort to realize practical power systems containing such fuel cells. This cathode structure is intended particularly to afford better cell performance at a low airflow rate. A membrane/electrode assembly of the type for which the improved cathode structure was developed (see Figure 1) is fabricated in a process that includes brush painting and spray coating of catalyst layers onto a polymer-electrolyte membrane and onto gas-diffusion backings that also act as current collectors. The aforementioned layers are then dried and hot-pressed together. When completed, the membrane/electrode assembly contains (1) an anode containing a fine metal black of Pt/Ru alloy, (2) a membrane made of Nafion 117 or equivalent (a perfluorosulfonic acid-based hydrophilic, proton-conducting ion-exchange polymer), (3) a cathode structure (in the present case, the improved cathode structure described below), and (4) the electrically conductive gas-diffusion backing layers, which are made of Toray 060(TradeMark)(or equivalent) carbon paper containing between 5 and 6 weight percent of poly(tetrafluoroethylene). The need for an improved cathode structure arises for the following reasons: In the design and operation of a fuel-cell power system, the airflow rate is a critical parameter that determines the overall efficiency, cell voltage, and power density. It is desirable to operate at a low airflow rate in order to obtain thermal and water balance and to minimize the size and mass of the system. The performances of membrane/electrode assemblies of prior design are limited at low airflow rates. Methanol crossover increases the required airflow rate. Hence, one way to reduce the required airflow rate is to reduce the effect of methanol crossover. Improvement of the cathode structure - in particular, addition of hydrophobic particles to the cathode - has been

  8. Microstructured Electrolyte Membranes to Improve Fuel Cell Performance

    Science.gov (United States)

    Wei, Xue

    Fuel cells, with the advantages of high efficiency, low greenhouse gas emission, and long lifetime are a promising technology for both portable power and stationary power sources. The development of efficient electrolyte membranes with high ionic conductivity, good mechanical durability and dense structure at low cost remains a challenge to the commercialization of fuel cells. This thesis focuses on exploring novel composite polymer membranes and ceramic electrolytes with the microstructure engineered to improve performance in direct methanol fuel cells (DMFCs) and solid oxide fuel cells (SOFCs), respectively. Polymer/particle composite membranes hold promise to meet the demands of DMFCs at lower cost. The structure of composite membranes was controlled by aligning proton conducting particles across the membrane thickness under an applied electric field. The field-induced structural changes caused the membranes to display an enhanced water uptake, proton conductivity, and methanol permeability in comparison to membranes prepared without an applied field. Although both methanol permeability and proton conductivity are enhanced by the applied field, the permeability increase is relatively lower than the proton conductivity improvement, which results in enhanced proton/methanol selectivity and improved DMFC performance. Apatite ceramics are a new class of fast ion conductors being studied as alternative SOFC electrolytes in the intermediate temperature range. An electrochemical/hydrothermal deposition method was developed to grow fully dense apatite membranes containing well-developed crystals with c-axis alignment to promote ion conductivity. Hydroxyapatite seed crystals were first deposited onto a metal substrate electrochemically. Subsequent ion substitution during the hydrothermal growth process promoted the formation of dense, fully crystalline films with microstructure optimal for ion transport. The deposition parameters were systematically investigated, such as

  9. Assessing the role of cell-surface molecules in central synaptogenesis in the Drosophila visual system.

    Directory of Open Access Journals (Sweden)

    Sandra Berger-Müller

    Full Text Available A hallmark of the central nervous system is its spatial and functional organization in synaptic layers. During neuronal development, axons form transient contacts with potential post-synaptic elements and establish synapses with appropriate partners at specific layers. These processes are regulated by synaptic cell-adhesion molecules. In the Drosophila visual system, R7 and R8 photoreceptor subtypes target distinct layers and form en passant pre-synaptic terminals at stereotypic loci of the axonal shaft. A leucine-rich repeat transmembrane protein, Capricious (Caps, is known to be selectively expressed in R8 axons and their recipient layer, which led to the attractive hypothesis that Caps mediates R8 synaptic specificity by homophilic adhesion. Contradicting this assumption, our results indicate that Caps does not have a prominent role in synaptic-layer targeting and synapse formation in Drosophila photoreceptors, and that the specific recognition of the R8 target layer does not involve Caps homophilic axon-target interactions. We generated flies that express a tagged synaptic marker to evaluate the presence and localization of synapses in R7 and R8 photoreceptors. These genetic tools were used to assess how the synaptic profile is affected when axons are forced to target abnormal layers by expressing axon guidance molecules. When R7 axons were mistargeted to the R8-recipient layer, R7s either maintained an R7-like synaptic profile or acquired a similar profile to r8s depending on the overexpressed protein. When R7 axons were redirected to a more superficial medulla layer, the number of presynaptic terminals was reduced. These results indicate that cell-surface molecules are able to dictate synapse loci by changing the axon terminal identity in a partially cell-autonomous manner, but that presynapse formation at specific sites also requires complex interactions between pre- and post-synaptic elements.

  10. Speaking through images: Implementing interaction through the visual language of The Economist. When the visual language becomes a useful tool to activate and improve communicative competence.

    OpenAIRE

    Leonzini, Luisella

    2012-01-01

    This paper will give examples of how the multi-semiotic visual language of “The Economist” provides a resourceful tool for triggering interaction and implementing learners’ spoken production. Images may activate various forms of communication by depicting metaphors as semantic shifts; the metaphorical semiotic code needs to be contextualised, with vehicle, topic and ground decoded first and then re-constructed as the final step. As a result the viewer will be involved in a process of interact...

  11. Visualization of Photoexcited Carrier Responses in a Solar Cell Using Optical Pump—Terahertz Emission Probe Technique

    Science.gov (United States)

    Nakanishi, Hidetoshi; Ito, Akira; Takayama, Kazuhisa; Kawayama, Iwao; Murakami, Hironaru; Tonouchi, Masayoshi

    2016-05-01

    We observed photoexcited carrier responses in solar cells excited by femtosecond laser pulses with spatial and temporal resolution using an optical pump-terahertz emission probe technique. We visualized the ultrafast local variation of the intensity of terahertz emission from a polycrystalline silicon solar cell using this technique and clearly observed the change in signals between a grain boundary and the inside of a grain in the solar cell. Further, the time evolution of the pump-probe signals of the polycrystalline and monocrystalline silicon solar cells was observed, and the relaxation times of photoexcited carriers in the emitter layers of crystalline silicon solar cells were estimated using this technique. The estimated relaxation time was consistent with the lifetime of the Auger recombination process that was dominant in heavily doped silicon used as an emitter layer for the silicon solar cells, which is difficult to obtain with photoluminescence method commonly used for the evaluation of solar cells.

  12. Parasol cell mosaics are unlikely to drive the formation of structured orientation maps in primary visual cortex.

    Science.gov (United States)

    Hore, Victoria R A; Troy, John B; Eglen, Stephen J

    2012-11-01

    The receptive fields of on- and off-center parasol cell mosaics independently tile the retina to ensure efficient sampling of visual space. A recent theoretical model represented the on- and off-center mosaics by noisy hexagonal lattices of slightly different density. When the two lattices are overlaid, long-range Moiré interference patterns are generated. These Moiré interference patterns have been suggested to drive the formation of highly structured orientation maps in visual cortex. Here, we show that noisy hexagonal lattices do not capture the spatial statistics of parasol cell mosaics. An alternative model based upon local exclusion zones, termed as the pairwise interaction point process (PIPP) model, generates patterns that are statistically indistinguishable from parasol cell mosaics. A key difference between the PIPP model and the hexagonal lattice model is that the PIPP model does not generate Moiré interference patterns, and hence stimulated orientation maps do not show any hexagonal structure. Finally, we estimate the spatial extent of spatial correlations in parasol cell mosaics to be only 200-350 μm, far less than that required to generate Moiré interference. We conclude that parasol cell mosaics are too disordered to drive the formation of highly structured orientation maps in visual cortex. PMID:23110776

  13. Ultrasonic radiation to enable improvement of direct methanol fuel cell.

    Science.gov (United States)

    Wu, Chaoqun; Wu, Jiang; Luo, Hao; Wang, Sanwu; Chen, Tao

    2016-03-01

    To improve DMFC (direct methanol fuel cell) performance, a new method using ultrasonic radiation is proposed and a novel DMFC structure is designed and fabricated in the present paper. Three ultrasonic transducers (piezoelectric transducer, PZT) are integrated in the flow field plate to form the ultrasonic field in the liquid fuel. Ultrasonic frequency, acoustic power, and methanol concentration have been considered as variables in the experiments. With the help of ultrasonic radiation, the maximum output power and limiting current of cell can be independently increased by 30.73% and 40.54%, respectively. The best performance of DMFC is obtained at the condition of ultrasonic radiation (30 kHz and 4 W) fed with 2M methanol solution, because both its limiting current and output power reach their maximum value simultaneously (222 mA and 33.6 mW, respectively) under this condition. These results conclude that ultrasonic can be an alternative choice for improving the cell performance, and can facilitate a guideline for the optimization of DMFC. PMID:26585016

  14. Improving translation success of cell-based therapies in orthopaedics.

    Science.gov (United States)

    Bara, Jennifer J; Herrmann, Marietta; Evans, Christopher H; Miclau, Theodore; Ratcliffe, Anthony; Richards, R Geoff

    2016-01-01

    There is a clear discrepancy between the growth of cell therapy and tissue engineering research in orthopaedics over the last two decades and the number of approved clinical therapies and products available to patients. At the 2015 annual meeting of the Orthopaedic Research Society, a workshop was held to highlight important considerations from the perspectives of an academic scientist, clinical researcher, and industry representative with the aim of helping researchers to successfully translate their ideas into clinical and commercial reality. Survey data acquired from workshop participants indicated an overall positive opinion on the future potential of cell-based therapies to make a significant contribution to orthopaedic medicine. The survey also indicated an agreement on areas requiring improvement in the development of new therapies, specifically; increased support for fundamental research and education and improved transparency of regulatory processes. This perspectives article summarises the content and conclusions of the workshop and puts forward suggestions on how translational success of cell-based therapies in orthopaedics may be achieved. PMID:26403666

  15. Blockade of pathological retinal ganglion cell hyperactivity improves optogenetically evoked light responses in rd1 mice

    Directory of Open Access Journals (Sweden)

    John Martin Barrett

    2015-08-01

    Full Text Available Retinitis pigmentosa (RP is a progressive retinal dystrophy that causes visual impairment and eventual blindness. Retinal prostheses are the best currently available vision-restoring treatment for RP, but only restore crude vision. One possible contributing factor to the poor quality of vision achieved with prosthetic devices is the pathological retinal ganglion cell (RGC hyperactivity that occurs in photoreceptor dystrophic disorders. Gap junction blockade with meclofenamic acid (MFA was recently shown to diminish RGC hyperactivity and improve the signal-to-noise ratio (SNR of RGC responses to light flashes and electrical stimulation in the rd10 mouse model of RP. We sought to extend these results to spatiotemporally patterned optogenetic stimulation in the faster-degenerating rd1 model and compare the effectiveness of a number of drugs known to disrupt rd1 hyperactivity.We crossed rd1 mice with a transgenic mouse line expressing the light-sensitive cation channel channelrhodopsin2 (ChR2 in RGCs, allowing them to be stimulated directly using high-intensity blue light. We used 60-channel ITO multielectrode arrays to record ChR2-mediated RGC responses from wholemount, ex-vivo retinas to full-field and patterned stimuli before and after application of MFA, 18-ß-glycyrrhetinic acid (18BGA, another gap junction blocker or flupirtine (Flu, a Kv7 potassium channel opener. All three drugs decreased spontaneous RGC firing, but 18BGA and Flu also decreased the sensitivity of RGCs to optogenetic stimulation. Nevertheless, all three drugs improved the SNR of ChR2-mediated responses. MFA also made it easier to discern motion direction of a moving bar from RGC population responses.Our results support the hypothesis that reduction of pathological RGC spontaneous activity characteristic in retinal degenerative disorders may improve the quality of visual responses in retinal prostheses and they provide insights into how best to achieve this for optogenetic

  16. Blockade of pathological retinal ganglion cell hyperactivity improves optogenetically evoked light responses in rd1 mice.

    Science.gov (United States)

    Barrett, John M; Degenaar, Patrick; Sernagor, Evelyne

    2015-01-01

    Retinitis pigmentosa (RP) is a progressive retinal dystrophy that causes visual impairment and eventual blindness. Retinal prostheses are the best currently available vision-restoring treatment for RP, but only restore crude vision. One possible contributing factor to the poor quality of vision achieved with prosthetic devices is the pathological retinal ganglion cell (RGC) hyperactivity that occurs in photoreceptor dystrophic disorders. Gap junction blockade with meclofenamic acid (MFA) was recently shown to diminish RGC hyperactivity and improve the signal-to-noise ratio (SNR) of RGC responses to light flashes and electrical stimulation in the rd10 mouse model of RP. We sought to extend these results to spatiotemporally patterned optogenetic stimulation in the faster-degenerating rd1 model and compare the effectiveness of a number of drugs known to disrupt rd1 hyperactivity. We crossed rd1 mice with a transgenic mouse line expressing the light-sensitive cation channel channelrhodopsin2 (ChR2) in RGCs, allowing them to be stimulated directly using high-intensity blue light. We used 60-channel ITO multielectrode arrays to record ChR2-mediated RGC responses from wholemount, ex-vivo retinas to full-field and patterned stimuli before and after application of MFA, 18-β-glycyrrhetinic acid (18BGA, another gap junction blocker) or flupirtine (Flu, a Kv7 potassium channel opener). All three drugs decreased spontaneous RGC firing, but 18BGA and Flu also decreased the sensitivity of RGCs to optogenetic stimulation. Nevertheless, all three drugs improved the SNR of ChR2-mediated responses. MFA also made it easier to discern motion direction of a moving bar from RGC population responses. Our results support the hypothesis that reduction of pathological RGC spontaneous activity characteristic in retinal degenerative disorders may improve the quality of visual responses in retinal prostheses and they provide insights into how best to achieve this for optogenetic prostheses

  17. ZnO nanopowder induced light scattering for improved visualization of emission sites in carbon nanotube films and arrays

    Science.gov (United States)

    Meško, Marcel; Ou, Qiongrong; Matsuda, Takafumi; Ishikawa, Tomokazu; Veis, Martin; Antoš, Roman; Ogino, Akihisa; Nagatsu, Masaaki

    2009-06-01

    We report on ZnO nanopowder induced light scattering for improved visualization of emission sites in carbon nanotube films and arrays. We observed a significant reduction of the internal multiple light scattering phenomena, which are characteristic for ZnO micropowders. The microsized grains of the commercially available ZnO:Zn (P 15) were reduced to the nanometre scale by pulsed laser ablation at an oxygen ambient pressure of 10 kPa. Our investigations show no crystalline change and no shift of the broad green emission peak at 500 nm for the ZnO nanopowder. For the application in field emission displays, we demonstrate the possibility of achieving cathodoluminescence with a fine pitch size of 100 µm of the patterned pixels without requiring additional electron beam focusing and without a black matrix. Moreover, the presented results show the feasibility of employing ZnO nanopowder as a detection material for the phosphorus screen method, which is able to localize emission sites of carbon nanotube films and arrays with an accuracy comparable to scanning anode field emission microscopy.

  18. ZnO nanopowder induced light scattering for improved visualization of emission sites in carbon nanotube films and arrays

    International Nuclear Information System (INIS)

    We report on ZnO nanopowder induced light scattering for improved visualization of emission sites in carbon nanotube films and arrays. We observed a significant reduction of the internal multiple light scattering phenomena, which are characteristic for ZnO micropowders. The microsized grains of the commercially available ZnO:Zn (P 15) were reduced to the nanometre scale by pulsed laser ablation at an oxygen ambient pressure of 10 kPa. Our investigations show no crystalline change and no shift of the broad green emission peak at 500 nm for the ZnO nanopowder. For the application in field emission displays, we demonstrate the possibility of achieving cathodoluminescence with a fine pitch size of 100 μm of the patterned pixels without requiring additional electron beam focusing and without a black matrix. Moreover, the presented results show the feasibility of employing ZnO nanopowder as a detection material for the phosphorus screen method, which is able to localize emission sites of carbon nanotube films and arrays with an accuracy comparable to scanning anode field emission microscopy.

  19. Software tools for simultaneous data visualization and T cell epitopes and disorder prediction in proteins.

    Science.gov (United States)

    Jandrlić, Davorka R; Lazić, Goran M; Mitić, Nenad S; Pavlović, Mirjana D

    2016-04-01

    We have developed EpDis and MassPred, extendable open source software tools that support bioinformatic research and enable parallel use of different methods for the prediction of T cell epitopes, disorder and disordered binding regions and hydropathy calculation. These tools offer a semi-automated installation of chosen sets of external predictors and an interface allowing for easy application of the prediction methods, which can be applied either to individual proteins or to datasets of a large number of proteins. In addition to access to prediction methods, the tools also provide visualization of the obtained results, calculation of consensus from results of different methods, as well as import of experimental data and their comparison with results obtained with different predictors. The tools also offer a graphical user interface and the possibility to store data and the results obtained using all of the integrated methods in the relational database or flat file for further analysis. The MassPred part enables a massive parallel application of all integrated predictors to the set of proteins. Both tools can be downloaded from http://bioinfo.matf.bg.ac.rs/home/downloads.wafl?cat=Software. Appendix A includes the technical description of the created tools and a list of supported predictors. PMID:26851400

  20. Kinetics of linear rouleaux formation studied by visual monitoring of red cell dynamic organization.

    Science.gov (United States)

    Barshtein, G; Wajnblum, D; Yedgar, S

    2000-05-01

    Red blood cells (RBCs) in the presence of plasma proteins or other macromolecules may form aggregates, normally in rouleaux formations, which are dispersed with increasing blood flow. Experimental observations have suggested that the spontaneous aggregation process involves the formation of linear rouleaux (FLR) followed by formation of branched rouleaux networks. Theoretical models for the spontaneous rouleaux formation were formulated, taking into consideration that FLR may involve both "polymerization," i.e., interaction between two single RBCs (e + e) and the addition of a single RBC to the end of an existing rouleau (e + r), as well as "condensation" between two rouleaux by end-to-end addition (r + r). The present study was undertaken to experimentally examine the theoretical models and their assumptions, by visual monitoring of the spontaneous FLR (from singly dispersed RBC) in plasma, in a narrow gap flow chamber. The results validate the theoretical model, showing that FLR involves both polymerization and condensation, and that the kinetic constants for the above three types of intercellular interactions are the same, i.e., k(ee) = k(er) = k(rr) = k, and for all tested hematocrits (0.625-6%) k < 0.13 +/- 0.03 s(-1). PMID:10777743

  1. Blue mode imaging may improve the detection and visualization of small-bowel lesions: A capsule endoscopy study

    Directory of Open Access Journals (Sweden)

    Usama M Abdelaal

    2015-01-01

    Full Text Available Background/Aims: Diagnostic miss rate and time consumption are the two challenging limitations of small-bowel capsule endoscopy (SBCE. In this study, we aimed to know whether using of the blue mode (BM combined with QuickView (QV at a high reviewing speed could influence SBCE interpretation and accuracy. Materials and Methods: Seventy CE procedures were totally reviewed in four different ways; (1 using the conventional white light, (2 using the BM, [on a viewing speed at 10 frames per second (fps], (3 using white light, and (4 using the BM (on a viewing speed at 20 fps. In study A, the results of (1 were compared with those of (2, and in study B, the results of (3 and (4 were separately compared with those of (1. Results: In study A, the total number of the vascular (P < 0.001 and the inflammatory lesions (P = 0.005 detected by BM was significantly higher than that detected by the white light. No lesion was found using the white light that was not detected by the BM. Moreover, the BM highly improved the image quality of all the vascular lesions and the erythematous ones from the nonvascular lesions. In study B, the total number of only the vascular lesions, detected by the BM on a rapid speed of viewing at 20 fps was significantly higher than that detected by the white light (P = 0.035. However, the true miss rate for the BM was 4%. Conclusion: BM imaging is a new method that improved the detection and visualization of the vascular and erythematous nonvascular lesions of SB as compared with the conventional white light imaging. Using of the BM at a slow viewing speed, markedly reduced the diagnostic miss rate of CE.

  2. A Simple, Visually Oriented Communication System to Improve Postoperative Care Following Microvascular Free Tissue Transfer: Development, Results, and Implications.

    Science.gov (United States)

    Henderson, Peter W; Landford, Wilmina; Gardenier, Jason; Otterburn, David M; Rohde, Christine H; Spector, Jason A

    2016-07-01

    Background Communication, particularly transmission of information between the surgical and nursing teams, has been identified as one of the most crucial determinants of patient outcomes. Nonetheless, transfer of information among and between the physician and nursing teams in the immediate postoperative period is often informal, verbal, and inconsistent. Methods An iterative process of multidisciplinary information gathering was undertaken to create a novel postoperative communication system (the "Pop-form"). Once developed, nurses were surveyed on multiple measures regarding the perceived likelihood that it would improve their ability to provide directed patient care. Data were quantified using a Likert scale (0-10), and statistically analyzed. Results The Pop-form records and transfers operative details, specific anatomic monitoring parameters, and senior physician contact information. Sixty-eight nurses completed surveys. The perceived usefulness of different components of the Pop-form system was as follows: 8.9 for the description of the procedure; 9.3 for the operative diagram; 9.4 for the monitoring details and parameters; and 9.4 for the direct contact information for the appropriate surgical team member. All respondents were in favor of widespread adoption of the Pop-form. Conclusion This uniform, visual communication system requires less than 1 minute to compose, yet formalizes and standardizes inter-team communication, and therefore shows promise for improving outcomes following microvascular free tissue transfer. We believe that this simple, innovative communication tool has the potential to be more broadly applied to many other health care settings. PMID:26872024

  3. Berkeley Lab Sheds Light on Improving Solar Cell Efficiency

    International Nuclear Information System (INIS)

    Typical manufacturing methods produce solar cells with an efficiency of 12-15%; and 14% efficiency is the bare minimum for achieving a profit. In work performed at the Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley, CA, 5 10-486-577 1)--a US Department of Energy national laboratory that conducts unclassified scientific research and is managed by the University of California--scientist Scott McHugo has obtained keen insights into the impaired performance of solar cells manufactured from polycrystalline silicon. The solar cell market is potentially vast, according to Berkeley Lab. Lightweight solar panels are highly beneficial for providing electrical power to remote locations in developing nations, since there is no need to build transmission lines or truck-in generator fuel. Moreover, industrial nations confronted with diminishing resources have active programs aimed at producing improved, less expensive solar cells. 'In a solar cell, there is a junction between p-type silicon and an n-type layer, such as diffused-in phosphorous', explained McHugo, who is now with Berkeley Lab's Accelerator and Fusion Research Division. 'When sunlight is absorbed, it frees electrons, which start migrating in a random-walk fashion toward that junction. If the electrons make it to the junction; they contribute to the cell's output of electric current. Often, however, before they reach the junction, they recombine at specific sites in the crystal' (and, therefore, cannot contribute to current output). McHugo scrutinized a map of a silicon wafer in which sites of high recombination appeared as dark regions. Previously, researchers had shown that such phenomena occurred not primarily at grain boundaries in the polycrystalline material, as might be expected, but more often at dislocations in the crystal. However, the dislocations themselves were not the problem. Using a unique heat treatment technique, McHugo performed electrical measurements to investigate the material

  4. Toward an Improved Haptic Zooming Algorithm for Graphical Information Accessed by Individuals Who Are Blind and Visually Impaired

    Science.gov (United States)

    Rastogi, Ravi; Pawluk, Dianne T. V.

    2013-01-01

    An increasing amount of information content used in school, work, and everyday living is presented in graphical form. Unfortunately, it is difficult for people who are blind or visually impaired to access this information, especially when many diagrams are needed. One problem is that details, even in relatively simple visual diagrams, can be very…

  5. Gaining a Better Understanding of Estuarine Circulation and Improving Data Visualization Skills Through a Hands-on Contouring Exercise

    Science.gov (United States)

    Mailloux, B. J.; Kenna, T. C.

    2008-12-01

    The creation and accurate interpretation of graphs is becoming a lost art among students. The availability of numerous graphing software programs makes the act of graphing data easy but does not necessarily aide students in interpreting complex visual data. This is especially true for contour maps; which have become a critical skill in the earth sciences and everyday life. In multiple classes, we have incorporated a large-scale, hands-on, contouring exercise of temperature, salinity, and density data collected in the Hudson River Estuary. The exercise allows students to learn first-hand how to plot, analyze, and present three dimensional data. As part of a day-long sampling expedition aboard an 80' research vessel, students deploy a water profiling instrument (Seabird CTD). Data are collected along a transect between the Verrazano and George Washington Bridges. The data are then processed and binned at 0.5 meter intervals. The processed data is then used during a later laboratory period for the contouring exercise. In class, students work in groups of 2 to 4 people and are provided with the data, a set of contouring instructions, a piece of large (3' x 3') graph paper, a ruler, and a set of colored markers. We then let the groups work together to determine the details of the graphs. Important steps along the way are talking to the students about X and Y scales, interpolation, and choices of contour intervals and colors. Frustration and bottlenecks are common at the beginning when students are unsure how to even begin with the raw data. At some point during the exercise, students start to understand the contour concept and each group usually produces a finished contour map in an hour or so. Interestingly, the groups take pride in the coloring portion of the contouring as it indicates successful interpretation of the data. The exercise concludes with each group presenting and discussing their contour plot. In almost every case, the hands-on graphing has improved the

  6. Visualization of radiation-induced cell cycle-associated events in tumor cells expressing the fusion protein of Azami Green and the destruction box of human Geminin

    International Nuclear Information System (INIS)

    Ionizing radiation (IR) influences cell cycle-associated events in tumor cells. We expressed the fusion protein of Azami Green (AG) and the destruction box plus nuclear localization signal of human Geminin, an inhibitor of DNA replication licensing factor, in oral tumor cells. This approach allowed us to visualize G2 arrest in living cells following irradiation. The combination of time-lapse imaging analysis allowed us to observe the nuclear envelope break down (NEBD) at early M phase, and disappearance of fluorescence (DF) at the end of M phase. The duration from NEBD to DF was not much affected in irradiated cells; however, most of daughter cells harbored double-strand breaks. Complete DF was also observed in cells exhibiting abnormal mitosis or cytokinesis. We conclude that the fluorescent Geminin probe could function as a stable cell cycle indicator irrespective of genome integrity.

  7. Novel technique for visualizing primordial germ cells in sturgeons (Acipenser ruthenus, A. gueldenstaedtii, A. baerii, and Huso huso).

    Science.gov (United States)

    Saito, Taiju; Psenicka, Martin

    2015-10-01

    Primordial germ cells (PGCs) are the origin of all germ cells in developing embryos. In the sturgeon embryo, PGCs develop from the vegetal hemisphere, which mainly acts as an extraembryonic source of nutrition. Current methods for studying sturgeon PGCs require either killing the fish or using costly and time-consuming histological procedures. Here, we demonstrate that visualization of sterlet (Acipenser ruthenus>) PGCs in vivo is feasible by simply labeling the vegetal hemisphere with fluorescein isothiocyanate (FITC)-dextran. We injected FITC-dextrans, with molecular weights varying between 10 000 and 2 000 000, into the vegetal pole of 1- to 4-cell stage embryos. At the neurula to tail-bud developmental stages, FITC-positive PGC-like cells appeared ventrally around the developing tail bud in the experimental group that received a high-molecular-weight FITC-dextran. The highest average number of FITC-positive PGC-like cells was observed in embryos injected with FITC-dextran having a molecular weight of 500 000 (FD-500). The pattern of migration of the labeled cells was identical to that of PGCs, clearly indicating that the FITC-positive PGC-like cells were PGCs. Labeled vegetal cells, except for the PGCs, were digested and excreted before the embryos starting feeding. FITC-labeled PGCs were observed in the developing gonads of fish for at least 3 mo after injection. We also found that FD-500 could be used to visualize PGCs in other sturgeon species. To the best of our knowledge, this report is the first to demonstrate in any animal species that PGCs can be visualized in vivo for a long period by the injection of a simple reagent. PMID:26134864

  8. Comparison between numerical simulation and visualization experiment on water behavior in single straight flow channel polymer electrolyte fuel cells

    Science.gov (United States)

    Masuda, Hiromitsu; Ito, Kohei; Oshima, Toshihiro; Sasaki, Kazunari

    A relationship between a flooding and a cell voltage drop for polymer electrolyte fuel cell was investigated experimentally and numerically. A visualization cell, which has single straight gas flow channel (GFC) and observation window, was fabricated to visualize the flooding in GFC. We ran the cell with changing operation condition, and measured the time evolution of cell voltage and took the images of cathode GFC. Considering the operation condition, we executed a developed numerical simulation, which is based on multiphase mixture model with a formulation on water transport through the surface of polymer electrolyte membrane and the interface of gas diffusion layer/GFC. As a result in experiment, we found that the cell voltage decreased with time and this decrease was accelerated by larger current and smaller air flow rate. Our simulation succeeded to demonstrate this trend of cell voltage. In experiment, we also found that the water flushing in GFC caused an immediate voltage change, resulting in voltage recovery or electricity generation stop. Although our simulation could not replicate this immediate voltage change, the supersaturated area obtained by our simulation well corresponded to fogging area appeared on the window surface in the GFC.

  9. Visualization rhetoric: framing effects in narrative visualization.

    Science.gov (United States)

    Hullman, Jessica; Diakopoulos, Nicholas

    2011-12-01

    Narrative visualizations combine conventions of communicative and exploratory information visualization to convey an intended story. We demonstrate visualization rhetoric as an analytical framework for understanding how design techniques that prioritize particular interpretations in visualizations that "tell a story" can significantly affect end-user interpretation. We draw a parallel between narrative visualization interpretation and evidence from framing studies in political messaging, decision-making, and literary studies. Devices for understanding the rhetorical nature of narrative information visualizations are presented, informed by the rigorous application of concepts from critical theory, semiotics, journalism, and political theory. We draw attention to how design tactics represent additions or omissions of information at various levels-the data, visual representation, textual annotations, and interactivity-and how visualizations denote and connote phenomena with reference to unstated viewing conventions and codes. Classes of rhetorical techniques identified via a systematic analysis of recent narrative visualizations are presented, and characterized according to their rhetorical contribution to the visualization. We describe how designers and researchers can benefit from the potentially positive aspects of visualization rhetoric in designing engaging, layered narrative visualizations and how our framework can shed light on how a visualization design prioritizes specific interpretations. We identify areas where future inquiry into visualization rhetoric can improve understanding of visualization interpretation. PMID:22034342

  10. Visualization and quantitative analysis of extrachromosomal telomere-repeat DNA in individual human cells by Halo-FISH.

    Science.gov (United States)

    Komosa, Martin; Root, Heather; Meyn, M Stephen

    2015-02-27

    Current methods for characterizing extrachromosomal nuclear DNA in mammalian cells do not permit single-cell analysis, are often semi-quantitative and frequently biased toward the detection of circular species. To overcome these limitations, we developed Halo-FISH to visualize and quantitatively analyze extrachromosomal DNA in single cells. We demonstrate Halo-FISH by using it to analyze extrachromosomal telomere-repeat (ECTR) in human cells that use the Alternative Lengthening of Telomeres (ALT) pathway(s) to maintain telomere lengths. We find that GM847 and VA13 ALT cells average ∼80 detectable G/C-strand ECTR DNA molecules/nucleus, while U2OS ALT cells average ∼18 molecules/nucleus. In comparison, human primary and telomerase-positive cells contain 300), range widely in length (200 kb) and are composed of primarily G- or C-strand telomere-repeat DNA. Halo-FISH enables, for the first time, the simultaneous analysis of ECTR DNA and chromosomal telomeres in a single cell. We find that ECTR DNA comprises ∼15% of telomere-repeat DNA in GM847 and VA13 cells, but <4% in U2OS cells. In addition to its use in ALT cell analysis, Halo-FISH can facilitate the study of a wide variety of extrachromosomal DNA in mammalian cells. PMID:25662602

  11. Alpha-bungarotoxin binding to target cell in a developing visual system by carboxylated nanodiamond

    Science.gov (United States)

    Liu, Kuang-Kai; Chen, Mei-Fang; Chen, Po-Yi; Lee, Tony J. F.; Cheng, Chia-Liang; Chang, Chia-Ching; Ho, Yen-Peng; Chao, Jui-I.

    2008-05-01

    Biological molecules conjugating with nanoparticles are valuable for applications including bio-imaging, bio-detection, and bio-sensing. Nanometer-sized diamond particles have excellent electronic and chemical properties for bio-conjugation. In this study, we manipulated the carboxyl group produced on the surface of nanodiamond (carboxylated nanodiamond, cND) for conjugating with alpha-bungarotoxin (α-BTX), a neurotoxin derived from Bungarus multicinctus with specific blockade of alpha7-nicotinic acetylcholine receptor (α7-nAChR). The electrostatic binding of cND-α-BTX was mediated by the negative charge of the cND and the positive charge of the α-BTX in physiological pH conditions. Sodium dodecyl sulfate-polyacrylamide gel analysis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI/TOF-MS) spectra displayed that α-BTX proteins were conjugated with cND particles via non-covalent bindings. The green fluorescence of the cND particles combining with the red fluorescence of tetramethylrhodamine-labeled α-BTX presented a yellow color at the same location, which indicated that α-BTX proteins were conjugated with cND particles. Xenopus laevis's oocytes expressed the human α7-nAChR proteins by microinjection with α7-nAChR mRNA. The cND-α-BTX complexes were bound to α7-nAChR locating on the cell membrane of oocytes and human lung A549 cancer cells analyzed by laser scanning confocal microscopy. The choline-evoked α7-nAChR-mediated inward currents of the oocytes were blocked by cND-α-BTX complexes in a concentration-dependent manner using two-electrode voltage-clamp recording. Furthermore, the fluorescence intensity of cND-α-BTX binding on A549 cells could be quantified by flow cytometry. These results indicate that cND-conjugated α-BTX still preserves its biological activity in blocking the function of α7-nAChR, and provide a visual system showing the binding of α-BTX to α7-nAChR.

  12. Alpha-bungarotoxin binding to target cell in a developing visual system by carboxylated nanodiamond

    International Nuclear Information System (INIS)

    Biological molecules conjugating with nanoparticles are valuable for applications including bio-imaging, bio-detection, and bio-sensing. Nanometer-sized diamond particles have excellent electronic and chemical properties for bio-conjugation. In this study, we manipulated the carboxyl group produced on the surface of nanodiamond (carboxylated nanodiamond, cND) for conjugating with alpha-bungarotoxin (α-BTX), a neurotoxin derived from Bungarus multicinctus with specific blockade of alpha7-nicotinic acetylcholine receptor (α7-nAChR). The electrostatic binding of cND-α-BTX was mediated by the negative charge of the cND and the positive charge of the α-BTX in physiological pH conditions. Sodium dodecyl sulfate-polyacrylamide gel analysis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI/TOF-MS) spectra displayed that α-BTX proteins were conjugated with cND particles via non-covalent bindings. The green fluorescence of the cND particles combining with the red fluorescence of tetramethylrhodamine-labeled α-BTX presented a yellow color at the same location, which indicated that α-BTX proteins were conjugated with cND particles. Xenopus laevis's oocytes expressed the human α7-nAChR proteins by microinjection with α7-nAChR mRNA. The cND-α-BTX complexes were bound to α7-nAChR locating on the cell membrane of oocytes and human lung A549 cancer cells analyzed by laser scanning confocal microscopy. The choline-evoked α7-nAChR-mediated inward currents of the oocytes were blocked by cND-α-BTX complexes in a concentration-dependent manner using two-electrode voltage-clamp recording. Furthermore, the fluorescence intensity of cND-α-BTX binding on A549 cells could be quantified by flow cytometry. These results indicate that cND-conjugated α-BTX still preserves its biological activity in blocking the function of α7-nAChR, and provide a visual system showing the binding of α-BTX to α7-nAChR

  13. Surface modification of semiconductor photoelectrode for improved solar cell performance

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, Mridula [Department of Chemistry, C.M.P. Degree College, University of Allahabad, Allahabad (India); Pandey, Kamlesh [National Centre of Experimental Mineralogy and Petrology, University of Allahabad, Allahabad (India); Kumar, Shiv Datt [Department of Mathematics, Motilal Nehru National Institute of Technology, Allahabad (India)

    2007-11-06

    The investigation is focused on the synthesis of nanostructured TiO{sub 2}-CuO admixed photoelectrode and its use as a photoelectrode of high-efficiency PEC solar cells for hydrogen production. TiO{sub 2}, in the nanostructured form, has been prepared by hydrolysis of titanium(IV) isopropoxide solution. An improvement in the nanostructured TiO{sub 2} photoelectrode carried out in the present work corresponds to admixing CuO to improve the spectral response. In the present study, photo-electrochemical (PEC) and hydrogen evolution characteristics of new types of ns-TiO{sub 2}-CuO admixed/Ti septum-based semiconductor septum photo-electrochemical (SC-SEP PEC) solar cell has been studied. The CuO admixed ns-TiO{sub 2} exhibited a high photocurrent and photovoltage of 18.6 mA/cm{sup 2} and 680 mV, respectively. The ns-TiO{sub 2}-CuO electrode exhibited a higher hydrogen gas evolution rate of 14.00 l/h m{sup 2}. (author)

  14. Improved Wide Operating Temperature Range of Li-Ion Cells

    Science.gov (United States)

    Smart, Marshall C.; Bugga, Ratnakumar V.

    2013-01-01

    Future NASA missions aimed at exploring the Moon, Mars, and the outer planets require rechargeable batteries that can operate over a wide temperature range (-60 to +60 C) to satisfy the requirements of various applications including landers, rovers, penetrators, CEV, CLV, etc. This work addresses the need for robust rechargeable batteries that can operate well over a wide temperature range. The Department of Energy (DoE) has identified a number of technical barriers associated with the development of Liion rechargeable batteries for PHEVs. For this reason, DoE has interest in the development of advanced electrolytes that will improve performance over a wide range of temperatures, and lead to long life characteristics (5,000 cycles over a 10-year life span). There is also interest in improving the high-voltage stability of these candidate electrolyte systems to enable the operation of up to 5 V with high specific energy cathode materials. Currently, the state-of-the-art lithium-ion system has been demonstrated to operate over a wide range of temperatures (-40 to +40 C); however, the rate capability at the lower temperatures is very poor. In addition, the low-temperature performance typically deteriorates rapidly upon being exposed to high temperatures. A number of electrolyte formulations were developed that incorporate the use of electrolyte additives to improve the high-temperature resilience, low-temperature power capability, and life characteristics of methyl propionate (MP)-based electrolyte solutions. These electrolyte additives include mono-fluoroethylene carbonate (FEC), lithium oxalate, vinylene carbonate (VC), and lithium bis(oxalate borate) (LiBOB), which have previously been shown to result in improved high-temperature resilience of all carbonate-based electrolytes. These MP-based electrolytes with additives have been shown to have improved performance in experiments with MCMB-LiNiCoAlO2 cells.

  15. Viral vector-based improvement of optic nerve regeneration: characterization of individual axons' growth patterns and synaptogenesis in a visual target.

    Science.gov (United States)

    Yungher, B J; Luo, X; Salgueiro, Y; Blackmore, M G; Park, K K

    2015-10-01

    Lack of axon growth ability in the central nervous system poses a major barrier to achieving functional connectivity after injury. Thus, a non-transgenic regenerative approach to reinnervating targets has important implications in clinical and research settings. Previous studies using knockout (KO) mice have demonstrated long-distance axon regeneration. Using an optic nerve injury model, here we evaluate the efficacy of viral, RNA interference (RNAi) and pharmacological approaches that target the phosphatase and tensin homolog (PTEN) and signal transducer and activator of transcription-3 pathways to improve long-distance axon regeneration in wild-type mice. Our data show that adeno-associated virus (AAV) expressing short hairpin RNA (shRNA) against PTEN (shPTEN) enhances retinal ganglion cell axon regeneration after crush injury. However, compared with the previous data in PTEN KO mice, AAV-shRNA results in a lesser degree of regeneration, likely due to incomplete gene silencing inherent to RNAi. In comparison, an extensive enhancement in regeneration is seen when AAV-shPTEN is coupled to AAV encoding ciliary neurotrophic factor (CNTF) and to a cyclic adenosine monophosphate (cAMP) analog, allowing axons to travel long distances and reach their target. We apply whole-tissue imaging that facilitates three-dimensional visualization of single regenerating axons and document heterogeneous terminal patterns in the targets. This shows that some axonal populations generate extensive arbors and make synapses with the target neurons. Collectively, we show a combinatorial viral RNAi and pharmacological strategy that improves long-distance regeneration in wild-type animals and provide single fiber projection data that indicates a degree of preservation of target recognition. PMID:26005861

  16. Improvement of Cell Survival During Human Pluripotent Stem Cell Definitive Endoderm Differentiation.

    Science.gov (United States)

    Wang, Han; Luo, Xie; Yao, Li; Lehman, Donna M; Wang, Pei

    2015-11-01

    Definitive endoderm (DE) is a vital precursor for internal organs such as liver and pancreas. Efficient protocol to differentiate human embryonic stem cells (hESCs) or induced pluripotent stem cells (iPSCs) to DE is essential for regenerative medicine and for modeling diseases; yet, poor cell survival during DE differentiation remains unsolved. In this study, our use of B27 supplement in modified differentiation protocols has led to a substantial improvement. We used an SOX17-enhanced green fluorescent protein (eGFP) reporter hESC line to compare and modify established DE differentiation protocols. Both total live cell numbers and the percentages of eGFP-positive cells were used to assess differentiation efficiency. Among tested protocols, three modified protocols with serum-free B27 supplement were developed to generate a high number of DE cells. Massive cell death was avoided during DE differentiation and the percentage of DE cells remained high. When the resulting DE cells were further differentiated toward the pancreatic lineage, the expression of pancreatic-specific markers was significantly increased. Similar high DE differentiation efficiency was observed in H1 hESCs and iPSCs through the modified protocols. In B27 components, bovine serum albumin was found to facilitate DE differentiation and cell survival. Using our modified DE differentiation protocols, satisfactory quantities of quality DE can be produced as primary material for further endoderm lineage differentiation. PMID:26132288

  17. Behavior of a metabolic cycling population at the single cell level as visualized by fluorescent gene expression reporters.

    Directory of Open Access Journals (Sweden)

    Sunil Laxman

    Full Text Available BACKGROUND: During continuous growth in specific chemostat cultures, budding yeast undergo robust oscillations in oxygen consumption that are accompanied by highly periodic changes in transcript abundance of a majority of genes, in a phenomenon called the Yeast Metabolic Cycle (YMC. This study uses fluorescent reporters of genes specific to different YMC phases in order to visualize this phenomenon and understand the temporal regulation of gene expression at the level of individual cells within the cycling population. METHODOLOGY: Fluorescent gene expression reporters for different phases of the YMC were constructed and stably integrated into the yeast genome. Subsequently, these reporter-expressing yeast were used to visualize YMC dynamics at the individual cell level in cultures grown in a chemostat or in a microfluidics platform under varying glucose concentrations, using fluorescence microscopy and quantitative Western blots. CONCLUSIONS: The behavior of single cells within a metabolic cycling population was visualized using phase-specific fluorescent reporters. The reporters largely recapitulated genome-specified mRNA expression profiles. A significant fraction of the cell population appeared to exhibit basal expression of the reporters, supporting the hypothesis that there are at least two distinct subpopulations of cells within the cycling population. Although approximately half of the cycling population initiated cell division in each permissive window of the YMC, metabolic synchrony of the population was maintained. Using a microfluidics platform we observed that low glucose concentrations appear to be necessary for metabolic cycling. Lastly, we propose that there is a temporal window in the oxidative growth phase of the YMC where the cycling population segregates into at least two subpopulations, one which will enter the cell cycle and one which does not.

  18. Efficient decellularization of whole porcine kidneys improves reseeded cell behavior.

    Science.gov (United States)

    Poornejad, Nafiseh; Momtahan, Nima; Salehi, Amin S M; Scott, Daniel R; Fronk, Cory A; Roeder, Beverly L; Reynolds, Paul R; Bundy, Bradley C; Cook, Alonzo D

    2016-01-01

    Combining patient-specific cells with the appropriate scaffold to create functional kidneys is a promising technology to provide immunocompatible kidneys for the 100 000+  patients on the organ waiting list. For proper recellularization to occur, the scaffold must possess the critical microstructure and an intact vascular network. Detergent perfusion through the vasculature of a kidney is the preferred method of decellularization; however, harsh detergents could be damaging to the microstructure of the renal tissue and may undesirably solubilize the endogenous growth and signaling factors. In this study, automated decellularization of whole porcine kidneys was performed using an improved method that combined physical and chemical steps to efficiently remove cellular materials while producing minimal damage to the collagenous extracellular matrix (ECM). Freezing/thawing, incremental increases in flow rate under constant pressure, applying osmotic shock to the cellular membranes, and low concentrations of the detergent sodium dodecyl sulfate (SDS) were factors used to decrease SDS exposure time during the decellularization process from 36 to 5 h, which preserved the microstructure while still removing 99% of the DNA. The well-preserved glycosaminoglycans (GAGs) and collagen fibers enhanced cell-ECM interactions. Human renal cortical tubular epithelium (RCTE) cells grew more rapidly when cultured on the ECM obtained from the improved decellularization process and also demonstrated more in vivo-like gene expression patterns. The optimized, automated process that resulted from this work is now used routinely in our laboratory to rapidly decellularize porcine kidneys and could be adapted to other large organs (e.g. heart, liver, and lung). PMID:26963774

  19. Targeting dendritic cells for improved HIV-1 vaccines.

    Science.gov (United States)

    Smed-Sörensen, Anna; Loré, Karin

    2013-01-01

    As dendritic cells (DCs) have the unique capacity to activate antigen-naive T cells they likely play a critical role in eliciting immune responses to vaccines. DCs are therefore being explored as attractive targets for vaccines, but understanding the interaction of DCs and clinically relevant vaccine antigens and adjuvants is a prerequisite. The HIV-1/AIDS epidemic continues to be a significant health problem, and despite intense research efforts over the past 30 years a protective vaccine has not yet been developed. A common challenge in vaccine design is to find a vaccine formulation that best shapes the immune response to protect against and/or control the given pathogen. Here, we discuss the importance of understanding the diversity, anatomical location and function of different human DC subsets in order to identify the optimal target cells for an HIV-1 vaccine. We review human DC interactions with some of the HIV-1 vaccine antigen delivery vehicles and adjuvants currently utilized in preclinical and clinical studies. Specifically, the effects of distinctly different vaccine adjuvants in terms of activation of DCs and improving DC function and vaccine efficacy are discussed. The susceptibility and responses of DCs to recombinant adenovirus vectors are reviewed, as well as the strategy of directly targeting DCs by using DC marker-specific monoclonal antibodies coupled to an antigen. PMID:22975879

  20. Improved detection suggests all Merkel cell carcinomas harbor Merkel polyomavirus.

    Science.gov (United States)

    Rodig, Scott J; Cheng, Jingwei; Wardzala, Jacek; DoRosario, Andrew; Scanlon, Jessica J; Laga, Alvaro C; Martinez-Fernandez, Alejandro; Barletta, Justine A; Bellizzi, Andrew M; Sadasivam, Subhashini; Holloway, Dustin T; Cooper, Dylan J; Kupper, Thomas S; Wang, Linda C; DeCaprio, James A

    2012-12-01

    A human polyomavirus was recently discovered in Merkel cell carcinoma (MCC) specimens. The Merkel cell polyomavirus (MCPyV) genome undergoes clonal integration into the host cell chromosomes of MCC tumors and expresses small T antigen and truncated large T antigen. Previous studies have consistently reported that MCPyV can be detected in approximately 80% of all MCC tumors. We sought to increase the sensitivity of detection of MCPyV in MCC by developing antibodies capable of detecting large T antigen by immunohistochemistry. In addition, we expanded the repertoire of quantitative PCR primers specific for MCPyV to improve the detection of viral DNA in MCC. Here we report that a novel monoclonal antibody detected MCPyV large T antigen expression in 56 of 58 (97%) unique MCC tumors. PCR analysis specifically detected viral DNA in all 60 unique MCC tumors tested. We also detected inactivating point substitution mutations of TP53 in the two MCC specimens that lacked large T antigen expression and in only 1 of 56 tumors positive for large T antigen. These results indicate that MCPyV is present in MCC tumors more frequently than previously reported and that mutations in TP53 tend to occur in MCC tumors that fail to express MCPyV large T antigen. PMID:23114601

  1. Improved detection suggests all Merkel cell carcinomas harbor Merkel polyomavirus

    Science.gov (United States)

    Rodig, Scott J.; Cheng, Jingwei; Wardzala, Jacek; DoRosario, Andrew; Scanlon, Jessica J.; Laga, Alvaro C.; Martinez-Fernandez, Alejandro; Barletta, Justine A.; Bellizzi, Andrew M.; Sadasivam, Subhashini; Holloway, Dustin T.; Cooper, Dylan J.; Kupper, Thomas S.; Wang, Linda C.; DeCaprio, James A.

    2012-01-01

    A human polyomavirus was recently discovered in Merkel cell carcinoma (MCC) specimens. The Merkel cell polyomavirus (MCPyV) genome undergoes clonal integration into the host cell chromosomes of MCC tumors and expresses small T antigen and truncated large T antigen. Previous studies have consistently reported that MCPyV can be detected in approximately 80% of all MCC tumors. We sought to increase the sensitivity of detection of MCPyV in MCC by developing antibodies capable of detecting large T antigen by immunohistochemistry. In addition, we expanded the repertoire of quantitative PCR primers specific for MCPyV to improve the detection of viral DNA in MCC. Here we report that a novel monoclonal antibody detected MCPyV large T antigen expression in 56 of 58 (97%) unique MCC tumors. PCR analysis specifically detected viral DNA in all 60 unique MCC tumors tested. We also detected inactivating point substitution mutations of TP53 in the two MCC specimens that lacked large T antigen expression and in only 1 of 56 tumors positive for large T antigen. These results indicate that MCPyV is present in MCC tumors more frequently than previously reported and that mutations in TP53 tend to occur in MCC tumors that fail to express MCPyV large T antigen. PMID:23114601

  2. Use of visual CO2 feedback as a retrofit solution for improving classroom air quality

    DEFF Research Database (Denmark)

    Wargocki, Pawel; Da Silva, Nuno Alexandre Faria

    2015-01-01

    Carbon dioxide (CO2) sensors that provide a visual indication were installed in classrooms during normal school operation. During 2-week periods, teachers and students were instructed to open the windows in response to the visual CO2 feedback in 1week and open them, as they would normally do...... other pair with no cooling. Classrooms were matched by grade. Providing visual CO2 feedback reduced CO2 levels, as more windows were opened in this condition. This increased energy use for heating and reduced the cooling requirement in summertime. Split cooling reduced the frequency of window opening...

  3. Development of improved cathodes for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, H.U.

    1991-03-01

    The University of Missouri-Rolla conducted a 17 month research program focused on the development and evaluation of improved cathode materials for solid oxide fuel cells (SOFC). The objectives of this program were: (1) the development of cathode materials of improved stability in reducing environments; and (2) the development of cathode materials with improved electrical conductivity. The program was successful in identifying some potential candidate materials: Air sinterable (La,Ca)(Cr,Co)O{sub 3} compositions were developed and found to be more stable than La{sub .8}Sr{sub .2}MnO{sub 3} towards reduction. Their conductivity at 1000{degrees}C ranged between 30 to 60 S/cm. Compositions within the (Y,Ca)(Cr,Co,Mn)O{sub 3} system were developed and found to have higher electrical conductivity than La{sub .8}Sr{sub .2}MnO{sub 3} and preliminary results suggest that their stability towards reduction is superior.

  4. Myelin repair by Schwann cells in the regenerating goldfish visual pathway: regional patterns revealed by X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nona, S.N.; Stafford, C.A.; Cronly-Dillon, J.R. (Manchester Univ. (United Kingdom). Inst. of Science and Technology); Duncan, A. (Guy' s Hospital, London (United Kingdom). Dept. of Anatomy); Scholes, J. (University Coll., London (United Kingdom))

    1994-07-01

    In the regenerating goldfish optic nerves, Schwann cells of unknown origin reliably infiltrate the lesion site forming a band of peripheral-type myelinating tissue by 1-2 months, sharply demarcated form the adjacent new CNS myelin. To investigate this effect, we have interfered with cell proliferation by locally X-irradiating the fish visual pathway 24 h after the lesion. As assayed by immunohistochemistry and EM, irradiation retards until 6 months formation of new myelin by Schwann cells at the lesion site, and virtually abolishes oligodendrocyte myelination distally, but has little or no effect on nerve fibre regrowth. Optic nerve astrocyte processes normally fail to re-infiltrate the lesion, but re-occupy it after irradiation, suggesting that they are normally excluded by early cell proliferation at this site. Moreover, scattered myelinating Schwann cells also appear in the oligodendrocyte-depleted distal optic nerve after irradiation, although only as far as the optic tract. (Author).

  5. Treatment of one case of cerebral palsy combined with posterior visual pathway injury using autologous bone marrow mesenchymal stem cells

    OpenAIRE

    Li Min; Yu Aixue; Zhang Fangfang; Dai GuangHui; Cheng Hongbin; Wang Xiaodong; An Yihua

    2012-01-01

    Abstract Background Cerebral palsy is currently one of the major diseases that cause severe paralysis of the nervous system in children; approximately 9–30% of cerebral palsy patients are also visually impaired, for which no effective treatment is available. Bone marrow mesenchymal stem cells (BMSCs) have very strong self-renewal, proliferation, and pluripotent differentiation potentials. Therefore, autologous BMSC transplantation has become a novel method for treating cerebral palsy. Methods...

  6. Visualization study of motion and deformation of red blood cells in a microchannel with straight, divergent and convergent sections

    OpenAIRE

    Chen, Bin; Guo, Fang; Xiang, Hao

    2011-01-01

    The size of red blood cells (RBC) is on the same order as the diameter of microvascular vessels. Therefore, blood should be regarded as a two-phase flow system of RBCs suspended in plasma rather than a continuous medium of microcirculation. It is of great physiological and pathological significance to investigate the effects of deformation and aggregation of RBCs on microcirculation. In this study, a visualization experiment was conducted to study the microcirculatory behavior of RBCs in susp...

  7. A double dissociation of the acuity and crowding limits to letter identification, and the promise of improved visual screening.

    Science.gov (United States)

    Song, Shuang; Levi, Dennis M; Pelli, Denis G

    2014-01-01

    Here, we systematically explore the size and spacing requirements for identifying a letter among other letters. We measure acuity for flanked and unflanked letters, centrally and peripherally, in normals and amblyopes. We find that acuity, overlap masking, and crowding each demand a minimum size or spacing for readable text. Just measuring flanked and unflanked acuity is enough for our proposed model to predict the observer's threshold size and spacing for letters at any eccentricity. We also find that amblyopia in adults retains the character of the childhood condition that caused it. Amblyopia is a developmental neural deficit that can occur as a result of either strabismus or anisometropia in childhood. Peripheral viewing during childhood due to strabismus results in amblyopia that is crowding limited, like peripheral vision. Optical blur of one eye during childhood due to anisometropia without strabismus results in amblyopia that is acuity limited, like blurred vision. Furthermore, we find that the spacing:acuity ratio of flanked and unflanked acuity can distinguish strabismic amblyopia from purely anisometropic amblyopia in nearly perfect agreement with lack of stereopsis. A scatter diagram of threshold spacing versus acuity, one point per patient, for several diagnostic groups, reveals the diagnostic power of flanked acuity testing. These results and two demonstrations indicate that the sensitivity of visual screening tests can be improved by using flankers that are more tightly spaced and letter like. Finally, in concert with Strappini, Pelli, Di Pace, and Martelli (submitted), we jointly report a double dissociation between acuity and crowding. Two clinical conditions-anisometropic amblyopia and apperceptive agnosia-each selectively impair either acuity A or the spacing:acuity ratio S/A, not both. Furthermore, when we specifically estimate crowding, we find a double dissociation between acuity and crowding. Models of human object recognition will need to

  8. Genetic visualization with an improved GCaMP calcium indicator reveals spatiotemporal activation of the spinal motor neurons in zebrafish.

    Science.gov (United States)

    Muto, Akira; Ohkura, Masamichi; Kotani, Tomoya; Higashijima, Shin-ichi; Nakai, Junichi; Kawakami, Koichi

    2011-03-29

    Animal behaviors are generated by well-coordinated activation of neural circuits. In zebrafish, embryos start to show spontaneous muscle contractions at 17 to 19 h postfertilization. To visualize how motor circuits in the spinal cord are activated during this behavior, we developed GCaMP-HS (GCaMP-hyper sensitive), an improved version of the genetically encoded calcium indicator GCaMP, and created transgenic zebrafish carrying the GCaMP-HS gene downstream of the Gal4-recognition sequence, UAS (upstream activation sequence). Then we performed a gene-trap screen and identified the SAIGFF213A transgenic fish that expressed Gal4FF, a modified version of Gal4, in a subset of spinal neurons including the caudal primary (CaP) motor neurons. We conducted calcium imaging using the SAIGFF213A; UAS:GCaMP-HS double transgenic embryos during the spontaneous contractions. We demonstrated periodic and synchronized activation of a set of ipsilateral motor neurons located on the right and left trunk in accordance with actual muscle movements. The synchronized activation of contralateral motor neurons occurred alternately with a regular interval. Furthermore, a detailed analysis revealed rostral-to-caudal propagation of activation of the ipsilateral motor neuron, which is similar to but much slower than the rostrocaudal delay observed during swimming in later stages. Our study thus demonstrated coordinated activities of the motor neurons during the first behavior in a vertebrate. We propose the GCaMP technology combined with the Gal4FF-UAS system is a powerful tool to study functional neural circuits in zebrafish. PMID:21383146

  9. Improved retroviral suicide gene transfer in colon cancer cell lines after cell synchronization with methotrexate

    Directory of Open Access Journals (Sweden)

    Nordlinger Bernard

    2011-10-01

    Full Text Available Abstract Background Cancer gene therapy by retroviral vectors is mainly limited by the level of transduction. Retroviral gene transfer requires target cell division. Cell synchronization, obtained by drugs inducing a reversible inhibition of DNA synthesis, could therefore be proposed to precondition target cells to retroviral gene transfer. We tested whether drug-mediated cell synchronization could enhance the transfer efficiency of a retroviral-mediated gene encoding herpes simplex virus thymidine kinase (HSV-tk in two colon cancer cell lines, DHDK12 and HT29. Methods Synchronization was induced by methotrexate (MTX, aracytin (ara-C or aphidicolin. Gene transfer efficiency was assessed by the level of HSV-TK expression. Transduced cells were driven by ganciclovir (GCV towards apoptosis that was assessed using annexin V labeling by quantitative flow cytometry. Results DHDK12 and HT29 cells were synchronized in S phase with MTX but not ara-C or aphidicolin. In synchronized DHDK12 and HT29 cells, the HSV-TK transduction rates were 2 and 1.5-fold higher than those obtained in control cells, respectively. Furthermore, the rate of apoptosis was increased two-fold in MTX-treated DHDK12 cells after treatment with GCV. Conclusions Our findings indicate that MTX-mediated synchronization of target cells allowed a significant improvement of retroviral HSV-tk gene transfer, resulting in an increased cell apoptosis in response to GCV. Pharmacological control of cell cycle may thus be a useful strategy to optimize the efficiency of retroviral-mediated cancer gene therapy.

  10. Dual-energy CT-cholangiography in potential donors for living-related liver transplantation: Improved biliary visualization by intravenous morphine co-medication

    International Nuclear Information System (INIS)

    Purpose: To prospectively evaluate whether intravenous morphine co-medication improves bile duct visualization of dual-energy CT-cholangiography. Materials and methods: Forty potential donors for living-related liver transplantation underwent CT-cholangiography with infusion of a hepatobiliary contrast agent over 40 min. Twenty minutes after the beginning of the contrast agent infusion, either normal saline (n = 20 patients; control group [CG]) or morphine sulfate (n = 20 patients; morphine group [MG]) was injected. Forty-five minutes after initiation of the contrast agent, a dual-energy CT acquisition of the liver was performed. Applying dual-energy post-processing, pure iodine images were generated. Primary study goals were determination of bile duct diameters and visualization scores (on a scale of 0 to 3: 0—not visualized; 3—excellent visualization). Results: Bile duct visualization scores for second-order and third-order branch ducts were significantly higher in the MG compared to the CG (2.9 ± 0.1 versus 2.6 ± 0.2 [P < 0.001] and 2.7 ± 0.3 versus 2.1 ± 0.6 [P < 0.01], respectively). Bile duct diameters for the common duct and main ducts were significantly higher in the MG compared to the CG (5.9 ± 1.3 mm versus 4.9 ± 1.3 mm [P < 0.05] and 3.7 ± 1.3 mm versus 2.6 ± 0.5 mm [P < 0.01], respectively). Conclusion: Intravenous morphine co-medication significantly improved biliary visualization on dual-energy CT-cholangiography in potential donors for living-related liver transplantation

  11. Dual-energy CT-cholangiography in potential donors for living-related liver transplantation: Improved biliary visualization by intravenous morphine co-medication

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, C.M., E-mail: christof.sommer@med.uni-heidelberg.de [Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg (Germany); Schwarzwaelder, C.B.; Stiller, W. [Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg (Germany); Schindera, S.T. [Department of Diagnostic, Interventional, and Pediatric Radiology, University Hospital and University of Berne, Berne (Switzerland); Heye, T.; Stampfl, U.; Bellemann, N.; Holzschuh, M. [Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg (Germany); Schmidt, J.; Weitz, J. [Department of General, Abdominal and Transplantation Surgery, University Hospital Heidelberg, Heidelberg (Germany); Grenacher, L.; Kauczor, H.U.; Radeleff, B.A. [Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg (Germany)

    2012-09-15

    Purpose: To prospectively evaluate whether intravenous morphine co-medication improves bile duct visualization of dual-energy CT-cholangiography. Materials and methods: Forty potential donors for living-related liver transplantation underwent CT-cholangiography with infusion of a hepatobiliary contrast agent over 40 min. Twenty minutes after the beginning of the contrast agent infusion, either normal saline (n = 20 patients; control group [CG]) or morphine sulfate (n = 20 patients; morphine group [MG]) was injected. Forty-five minutes after initiation of the contrast agent, a dual-energy CT acquisition of the liver was performed. Applying dual-energy post-processing, pure iodine images were generated. Primary study goals were determination of bile duct diameters and visualization scores (on a scale of 0 to 3: 0—not visualized; 3—excellent visualization). Results: Bile duct visualization scores for second-order and third-order branch ducts were significantly higher in the MG compared to the CG (2.9 ± 0.1 versus 2.6 ± 0.2 [P < 0.001] and 2.7 ± 0.3 versus 2.1 ± 0.6 [P < 0.01], respectively). Bile duct diameters for the common duct and main ducts were significantly higher in the MG compared to the CG (5.9 ± 1.3 mm versus 4.9 ± 1.3 mm [P < 0.05] and 3.7 ± 1.3 mm versus 2.6 ± 0.5 mm [P < 0.01], respectively). Conclusion: Intravenous morphine co-medication significantly improved biliary visualization on dual-energy CT-cholangiography in potential donors for living-related liver transplantation.

  12. An improved tissue-mimicking polyacrylamide hydrogel phantom for visualizing thermal lesions with high-intensity focused ultrasound.

    Science.gov (United States)

    Guntur, Sitaramanjaneya Reddy; Choi, Min Joo

    2014-11-01

    A recipe was created to improve the tissue-mimicking (TM) bovine serum albumin (BSA) polyacrylamide hydrogel (PAG) reported in our previous study (Choi MJ, Guntur SR, Lee KI, Paeng DG, Coleman AJ. Ultrasound Med Biol 2013; 29:439-448). In that work, the concentration of acrylamide in TM BSA PAG was increased to make its attenuation coefficient the same as that of a tissue. However, this increase made the PAG stiffer and less homogeneous. In addition, the increase in acrylamide caused a significant increase in temperature over the denaturation threshold of BSA during polymerization, which required forced cooling so that the PAG did not become opaque at room temperature after polymerization. To eliminate those shortcomings, we substituted the increased acrylamide with a viscous polysaccharide liquid (corn syrup). The concentration of corn syrup was optimized to 20% (w/v, tested in the volume of 50 mL), so that the acoustic properties of the PAG would be close to those of human liver. The improved TM (iTM) BSA PAG constructed in this study had a speed of sound of 1588 ± 9 m/s, an attenuation coefficient of 0.51 ± 0.06 dB cm(-1) at 1 MHz and a backscattering coefficient of 0.22 ± 0.09 × 10(-3) sr(-1) cm(-1) MHz(-1). The density and acoustic impedance were 1057 kg/m(3) and 1.68 MRayl, respectively, and the non-linear parameter (B/A) was 5.9 ± 0.3. The thermal, optical and mechanical properties were almost the same as those of the BSA PAG (Lafon et al.2005). Experimental verification indicated that the thermal lesions visualized in the proposed iTM BSA PAG by high-intensity focused ultrasound were highly reproducible. In conclusion, iTM BSA PAG was proven to eliminate TM BSA PAG shortcomings effectively and is expected to be a promising test phantom for clinical high-intensity focused ultrasound device. PMID:25220272

  13. Visual Contrast Sensitivity Improvement by Right Frontal High-Beta Activity Is Mediated by Contrast Gain Mechanisms and Influenced by Fronto-Parietal White Matter Microstructure.

    Science.gov (United States)

    Quentin, Romain; Elkin Frankston, Seth; Vernet, Marine; Toba, Monica N; Bartolomeo, Paolo; Chanes, Lorena; Valero-Cabré, Antoni

    2016-06-01

    Behavioral and electrophysiological studies in humans and non-human primates have correlated frontal high-beta activity with the orienting of endogenous attention and shown the ability of the latter function to modulate visual performance. We here combined rhythmic transcranial magnetic stimulation (TMS) and diffusion imaging to study the relation between frontal oscillatory activity and visual performance, and we associated these phenomena to a specific set of white matter pathways that in humans subtend attentional processes. High-beta rhythmic activity on the right frontal eye field (FEF) was induced with TMS and its causal effects on a contrast sensitivity function were recorded to explore its ability to improve visual detection performance across different stimulus contrast levels. Our results show that frequency-specific activity patterns engaged in the right FEF have the ability to induce a leftward shift of the psychometric function. This increase in visual performance across different levels of stimulus contrast is likely mediated by a contrast gain mechanism. Interestingly, microstructural measures of white matter connectivity suggest a strong implication of right fronto-parietal connectivity linking the FEF and the intraparietal sulcus in propagating high-beta rhythmic signals across brain networks and subtending top-down frontal influences on visual performance. PMID:25899709

  14. Does an increase in compression force really improve visual image quality in mammography? – An initial investigation

    International Nuclear Information System (INIS)

    Objective: Literature speculates that visual image quality (IQ) and compression force levels may be directly related. This small study investigates whether a relationship exists between compression force levels and visual IQ. Method: To investigate how visual IQ varies with different levels of compression force, 39 clients were selected over a 6 year screening period that had received markedly different amounts of compression force on each of their three sequential screens. Images for the 3 screening episodes for all women were scored visually using 3 different IQ scales. Results: Correlation coefficients between the 3 IQ scales were positive and high (0.82, 0.9 and 0.85). For the scales, the IQ scores their correlation does not vary significantly, even though different compression levels had been applied. Kappa IQ scale 1: 0.92, 0.89, 0.89. ANOVA IQ scale 2: p = 0.98, p = 0.55, p = 0.56. ICC IQ scale 3: 0.97, 0.93, 0.91. Conclusion: For the 39 clients there is no difference in visual IQ when different amounts of compression are applied. We believe that further work should be conducted into compression force and image quality as ‘higher levels’ of compression force may not be justified in the attainment of suitable visual image quality

  15. Visualization of Fuel Cell Water Transport and Performance Characterization under Freezing Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kandlikar, S.G.; Lu, Z.; Rao, N.; Sergi, J.; Rath, C.; Dade, C.; Trabold, T.; Owejan, J.; Gagliardo, J.; Allen, J.; Yassar, R.S.; Medici, E.; Herescu, A.

    2010-05-30

    mechanism. The breakdown and redevelopment of the water paths in GDLs lead to an intermittent water drainage behavior, which is characterized by dynamic capillary pressure and changing of breakthrough location. MPL was found to not only limit the number of water entry locations into the GDL (thus drastically reducing water saturation), but also stabilizes the water paths (or morphology). • Simultaneously visualized the water transport on cathode and anode channels of an operating fuel cell. It was found that under relatively dry hydrogen/air conditions at lower temperatures, the cathode channels display a similar flow pattern map to the ex-situ experiments under similar conditions. Liquid water on the anode side is more likely formed via condensation of water vapor which is transported through the anode GDL. • Investigated the water percolation through the GDL with pseudo-Hele-Shaw experiments and simulated the capillary-driven two-phase flow inside gas diffusion media, with the pore size distributions being modeled by using Weibull distribution functions. The effect of the inclusion of the microporous layer in the fuel cell assembly was explored numerically. • Developed and validated a simple, reliable computational tool for predicting liquid water transport in GDLs. • Developed a new method of determining the pore size distribution in GDL using scanning electron microscope (SEM) image processing, which allows for separate characterization of GDL wetting properties and pore size distribution. • Determined the effect of surface wettability and channel cross section and bend dihedral on liquid holdup in fuel cell flow channels. A major thrust of this research program has been the development of an optimal combination of materials, design features and cell operating conditions that achieve a water management strategy which facilitates fuel cell operation under freezing conditions. Based on our various findings, we have made the final recommendation relative to GDL

  16. Improvement of uncorrected visual acuity (UCVA and contrast sensitivity (UCCS with perceptual learning and transcranial random noise stimulation (tRNS in individuals with mild myopia

    Directory of Open Access Journals (Sweden)

    Rebecca Camilleri

    2014-10-01

    Full Text Available Perceptual learning has been shown to produce an improvement of visual acuity (VA and contrast sensitivity (CS both in subjects with amblyopia and refractive defects such as myopia or presbyopia. Transcranial random noise stimulation (tRNS has proven to be efficacious in accelerating neural plasticity and boosting perceptual learning in healthy participants. In this study we investigated whether a short behavioural training regime using a contrast detection task combined with online tRNS was as effective in improving visual functions in participants with mild myopia compared to a two-month behavioural training regime without tRNS (Camilleri et al., 2014. After two weeks of perceptual training in combination with tRNS, participants showed an improvement of 0.15 LogMAR in uncorrected VA (UCVA that was comparable with that obtained after eight weeks of training with no tRNS, and an improvement in uncorrected CS (UCCS at various spatial frequencies (whereas no UCCS improvement was seen after eight weeks of training with no tRNS. On the other hand, a control group that trained for two weeks without stimulation did not show any significant UCVA or UCCS improvement. These results suggest that the combination of behavioural and neuromodulatory techniques can be fast and efficacious in improving sight in individuals with mild myopia.

  17. Visualization of the solubilization process of the plasma membrane of a living cell by waveguide evanescent field fluorescence microscopy

    Science.gov (United States)

    Hassanzadeh, Abdollah; Ma, Heun Kan; Dixon, S. Jeffrey; Mittler, Silvia

    2012-07-01

    Waveguide evanescent field fluorescence microscopy (WEFF) is a novel microscopy technology that allows imaging of a cell's plasma membrane in the vicinity of a glass substrate with high axial resolution, low background and little photobleaching. Time-lapse imaging can be performed to investigate changes in cell morphology in the presence or absence of chemical agents. WEFF microscopy provides a method to investigate plasma membranes of living cells and allows a comparison to simplified model membranes immobilized on planar substrates. The interaction of the nonionic detergent Triton X-100 with plasma membranes of osteoblasts in an aqueous environment was investigated. Solubilization of the membranes very close to the waveguide surface was visualized and related to the three-stage solubilisation model proposed for liposomes and supported lipid bilayers. Findings for the plasma membranes of cells are in excellent agreement with results reported for these artificial model systems.

  18. Human Embryonic and Hepatic Stem Cell Differentiation Visualized in Two and Three Dimensions Based on Serial Sections

    DEFF Research Database (Denmark)

    Vestentoft, Peter S.; Brøchner, Christian B; Lynnerup, Niels;

    2016-01-01

    Pluripotent human embryonic stem cells (hESCs) are characterized by two defining properties, self-renewal and differentiation. Self-renewing hESCs express transcription factors OCT4, SOX2, and NANOG, and surface markers SSEA-4 and TRA-1-60 and TRA-1-81 and their ability to differentiate into...... an entire colony is accomplished using 3D image processing software such as Mimics(®) or Amira(®). An extended version of this technique even allows for a high-magnification 3D-reconstruction of, e.g., hepatic stem cells in developing liver. These techniques combined allow for both a 2- and a 3......-dimensional visualization of hESC colonies and stem cells in organs, which leads to new insights into and information about the interaction of stem cells with their surroundings....

  19. On the chemical identification and visualization of uranium species in biofilms and Euglena mutabilis cells

    International Nuclear Information System (INIS)

    removed from the solutions by the cells without any detectable influence of the background media. Regarding the using of these cells for possible treatment procedures of real contaminated acid mine water the high immobilization rate of uranium at acidic conditions is very attractive. Living, metabolically active Euglena cells are able to accumulate more uranium than dead biomass as the results in this study show. The results of this study contribute to obtain a profound knowledge on the processes regarding the interactions of uranium with biofilms and in particular with Euglena mutabilis cells. The obtained findings help to improve the estimation of risks arising from contaminated environments and to optimize the prediction of the migration behavior of uranium.

  20. Integration of interactive three-dimensional image post-processing software into undergraduate radiology education effectively improves diagnostic skills and visual-spatial ability

    Energy Technology Data Exchange (ETDEWEB)

    Rengier, Fabian, E-mail: fabian.rengier@web.de [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Häfner, Matthias F. [University Hospital Heidelberg, Department of Radiation Oncology, Im Neuenheimer Feld 400, 69120 Heidelberg (Germany); Unterhinninghofen, Roland [Karlsruhe Institute of Technology (KIT), Institute for Anthropomatics, Department of Informatics, Adenauerring 2, 76131 Karlsruhe (Germany); Nawrotzki, Ralph; Kirsch, Joachim [University of Heidelberg, Institute of Anatomy and Cell Biology, Im Neuenheimer Feld 307, 69120 Heidelberg (Germany); Kauczor, Hans-Ulrich [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Giesel, Frederik L. [University of Heidelberg, Institute of Anatomy and Cell Biology, Im Neuenheimer Feld 307, 69120 Heidelberg (Germany); University Hospital Heidelberg, Department of Nuclear Medicine, Im Neuenheimer Feld 400, 69120 Heidelberg (Germany)

    2013-08-15

    Purpose: Integrating interactive three-dimensional post-processing software into undergraduate radiology teaching might be a promising approach to synergistically improve both visual-spatial ability and radiological skills, thereby reducing students’ deficiencies in image interpretation. The purpose of this study was to test our hypothesis that a hands-on radiology course for medical students using interactive three-dimensional image post-processing software improves radiological knowledge, diagnostic skills and visual-spatial ability. Materials and methods: A hands-on radiology course was developed using interactive three-dimensional image post-processing software. The course consisted of seven seminars held on a weekly basis. The 25 participating fourth- and fifth-year medical students learnt to systematically analyse cross-sectional imaging data and correlated the two-dimensional images with three-dimensional reconstructions. They were instructed by experienced radiologists and collegiate tutors. The improvement in radiological knowledge, diagnostic skills and visual-spatial ability was assessed immediately before and after the course by multiple-choice tests comprising 64 questions each. Wilcoxon signed rank test for paired samples was applied. Results: The total number of correctly answered questions improved from 36.9 ± 4.8 to 49.5 ± 5.4 (p < 0.001) which corresponded to a mean improvement of 12.6 (95% confidence interval 9.9–15.3) or 19.8%. Radiological knowledge improved by 36.0% (p < 0.001), diagnostic skills for cross-sectional imaging by 38.7% (p < 0.001), diagnostic skills for other imaging modalities – which were not included in the course – by 14.0% (p = 0.001), and visual-spatial ability by 11.3% (p < 0.001). Conclusion: The integration of interactive three-dimensional image post-processing software into undergraduate radiology education effectively improves radiological reasoning, diagnostic skills and visual-spatial ability, and thereby

  1. Integration of interactive three-dimensional image post-processing software into undergraduate radiology education effectively improves diagnostic skills and visual-spatial ability

    International Nuclear Information System (INIS)

    Purpose: Integrating interactive three-dimensional post-processing software into undergraduate radiology teaching might be a promising approach to synergistically improve both visual-spatial ability and radiological skills, thereby reducing students’ deficiencies in image interpretation. The purpose of this study was to test our hypothesis that a hands-on radiology course for medical students using interactive three-dimensional image post-processing software improves radiological knowledge, diagnostic skills and visual-spatial ability. Materials and methods: A hands-on radiology course was developed using interactive three-dimensional image post-processing software. The course consisted of seven seminars held on a weekly basis. The 25 participating fourth- and fifth-year medical students learnt to systematically analyse cross-sectional imaging data and correlated the two-dimensional images with three-dimensional reconstructions. They were instructed by experienced radiologists and collegiate tutors. The improvement in radiological knowledge, diagnostic skills and visual-spatial ability was assessed immediately before and after the course by multiple-choice tests comprising 64 questions each. Wilcoxon signed rank test for paired samples was applied. Results: The total number of correctly answered questions improved from 36.9 ± 4.8 to 49.5 ± 5.4 (p < 0.001) which corresponded to a mean improvement of 12.6 (95% confidence interval 9.9–15.3) or 19.8%. Radiological knowledge improved by 36.0% (p < 0.001), diagnostic skills for cross-sectional imaging by 38.7% (p < 0.001), diagnostic skills for other imaging modalities – which were not included in the course – by 14.0% (p = 0.001), and visual-spatial ability by 11.3% (p < 0.001). Conclusion: The integration of interactive three-dimensional image post-processing software into undergraduate radiology education effectively improves radiological reasoning, diagnostic skills and visual-spatial ability, and thereby

  2. Ontogenetic improvement of visual function in the medaka Oryzias latipes based on an optomotor testing system for larval and adult fish

    Science.gov (United States)

    Carvalho, P.S.M.; Noltie, D.B.; Tillitt, D.E.

    2002-01-01

    We developed a system for evaluation of visual function in larval and adult fish. Both optomotor (swimming) and optokinetic (eye movement) responses were monitored and recorded using a system of rotating stripes. The system allowed manipulation of factors such as width of the stripes used, rotation speed of the striped drum, and light illuminance levels within both the scotopic and photopic ranges. Precise control of these factors allowed quantitative measurements of visual acuity and motion detection. Using this apparatus, we tested the hypothesis that significant posthatch ontogenetic improvements in visual function occur in the medaka Oryzias latipes, and also that this species shows significant in ovo neuronal development. Significant improvements in the acuity angle alpha (ability to discriminate detail) were observed from approximately 5 degrees at hatch to 1 degree in the oldest adult stages. In addition, we measured a significant improvement in flicker fusion thresholds (motion detection skills) between larval and adult life stages within both the scotopic and photopic ranges of light illuminance. Ranges of flicker fusion thresholds (X?? ?? SD) at log I=1.96 (photopic) varied from 37.2 ?? 1.6 cycles/s in young adults to 18.6 ?? 1.6 cycles/s in young larvae 10 days posthatch. At log I= - 2.54 (scotopic), flicker fusion thresholds varied from 5.8 ?? 0.7 cycles/s in young adults to 1.7 ?? 0.4 cycles/s in young larvae 10 days posthatch. Light sensitivity increased approximately 2.9 log units from early hatched larval stages to adults. The demonstrated ontogenetic improvements in visual function probably enable the fish to explore new resources, thereby enlarging their fundamental niche. ?? 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.

  3. Quantify and improve PEM fuel cell durability. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Grahl-Madsen, L.; Odgaard, M.; Munksgaard Nielsen, R. (IRD Fuel Cell A/S, Svendborg (Denmark)); Li, Q.; Jensen, Jens Oluf (Technical Univ. of Denmark, Dept. of Chemistry, Kgs. Lyngby (Denmark)); Andersen, Shuang Ma; Speder, J.; Skou, E. (Syddansk Univ. (SDU), Odense (Denmark))

    2010-07-01

    approx 4,000 hours of operation correspond to a loss of catalytic active area of 58% for the anode and 69% for the cathode respectively, and the MEA can be expected to perform equivalent to MEAs with less than half the catalyst loating. DMFC durability tests were carried out on both Nafion and Hydrocarbon membrane based MEAs using different electrode designs. Several single DMFC cells and stacks have been tested up to 3,000 hours. The degradation rates found for both single cells and stacks were in the range between 10-90 muV/hours per cell, depending on the MEA configuration. Certain performance losses incurred by the cell during the steady-state operation were recovered, fully or in part, after the regular OCV hold. Regeneration of the Pt-catalyst particles include electro-reduction of the surface PtO that gradually forms over time, surface electro-oxidation of adsorbed poisons (namely CO formed from methanol crossover), and chemical reduction of PtO and/or PtOH via crossover methanol. The HT PEM FC results indicate that a degradation rate of approx 5 muV/h for HT PEM FC can be expected under continuous operation with hydrogen and air at 150-160 C, corresponding to a lifetime of 12,000 hours before 10% performance loss. This lifetime is somewhat shorter than aimed at in the national Danish HT PEM Road map (2009: 20,000 h), but it is in this context important to remember the limited knowledge on HT PEM lifetime at the time of the roadmap definition in 2008. The accelerated durability test with potential cycling showed significant catalyst degradation, primarily due to the corrosion of carbon supports, which triggers the platinum sintering/agglomeration. Modified catalyst supports in form of graphite or carbon nanotubes improve the catalyst and therefore the PBI cell durability. (LN)

  4. Super-resolution imaging with Pontamine Fast Scarlet 4BS enables direct visualization of cellulose orientation and cell connection architecture in onion epidermis cells

    DEFF Research Database (Denmark)

    Liesche, Johannes; Ziomkiewicz, Iwona; Schulz, Alexander

    2013-01-01

    microscopy of some 200 nm in xy and 550 nm in z for green light, restricts the direct visualization of cellulose to relatively large bundles, whereas the structure of cellulose microfibrils with their diameter below 10 nm remains unresolved. Over the last decade, several so-called super-resolution microscopy...... approaches have been developed; in this paper we explore the potential of such approaches for the direct visualization of cellulose. Results To ensure optimal imaging we determined the spectral properties of PFS-stained tissue. PFS was found not to affect cell viability in the onion bulb scale epidermis. We...... confocal microscopy and the approach could be used to demonstrate differences in fibril orientation in different layers of the cell wall as well as particular cellulose fortifications around plasmodesmata. Conclusions Super-resolution light microscopy of PFS-stained cellulose fibrils is possible...

  5. Improving the performance of monocular visual simultaneous localisation and mapping through the use of a gimballed camera

    Science.gov (United States)

    Playle, Nicholas

    In this thesis modern vision based localisation methods are discussed and contrasted with existing satellite based approaches. Shortcomings are noted and potential solutions are highlighted. A novel method of using a gimballed camera to perform visual Simultaneous Localisation and Mapping (SLAM) is proposed, along with a control algorithm to point the camera toward feature dense regions. This method is then modularly coupled with existing visual SLAM techniques allowing seamless integration across different platforms. Ground tests are performed to verify operation of the gimbal controller and rotation inverser. Results from experimental flight tests are incorporated as a final means of obtaining information to verify gimbal operation.

  6. Massive MIMO and Small Cells: Improving Energy Efficiency by Optimal Soft-Cell Coordination

    OpenAIRE

    Bjornson, Emil; Kountouris, Marios; Debbah, Merouane

    2013-01-01

    To improve the cellular energy efficiency, without sacrificing quality-of-service (QoS) at the users, the network topology must be densified to enable higher spatial reuse. We analyze a combination of two densification approaches, namely "massive" multiple-input multiple-output (MIMO) base stations and small-cell access points. If the latter are operator-deployed, a spatial soft-cell approach can be taken where the multiple transmitters serve the users by joint non-coherent multiflow beamform...

  7. Effects of the concomitant activation of ON and OFF retinal ganglion cells on the visual thalamus: evidence for an enhanced recruitment of GABAergic cells

    Directory of Open Access Journals (Sweden)

    Giovanni Montesano

    2015-11-01

    Full Text Available A fundamental question in vision neuroscience is how parallel processing of Retinal Ganglion Cell (RGC signals is integrated at the level of the visual thalamus. It is well known that parallel ON-OFF pathways generate output signals from the retina that are conveyed to the dorsal lateral geniculate nucleus (dLGN. However, it is unclear how these signals distribute onto thalamic cells and how these two pathways interact. Here, by electrophysiological recordings and c-Fos expression analysis, we characterized the effects of pharmacological manipulations of the retinal circuit aimed at inducing either a selective activation of a single pathway, OFF RGCs (intravitreal L-(+-2-Amino-4-phosphonobutyric, L-AP4 or an unregulated activity of all classes of retinal ganglion cells (intravitreal 4-Aminopyridine, 4-AP. In in vivo experiments, the analysis of c-Fos expression in the dLGN showed that these two manipulations recruited active cells from the same area, the lateral edge of the dLGN. Despite this similarity, the unregulated co-activation of both ON and OFF pathways by 4-AP yielded a much stronger recruitment of GABAergic interneurons in the dLGN when compared to L-AP4 pure OFF activation. The increased activation of an inhibitory thalamic network by a high level of unregulated discharge of ON and OFF RGCs might suggest that cross-inhibitory pathways between opposing visual channels are presumably replicated at multiple levels in the visual pathway, thus increasing the filtering ability for non-informative or noisy visual signals.

  8. The Method of Improving Non-computer Major's Interest in Visual Basic%提高非计算机专业Visual Basic课程学习兴趣的方法

    Institute of Scientific and Technical Information of China (English)

    程传鹏

    2011-01-01

    Visual Basic language is based on Windows platform,object-oriented visual programming language,with its intuitive,easy to learn the characteristics.Therefore,many universities regard the VB as a non-computer professional to teach computer basic course.This paper analyzes the common problems of VB teaching in non computer science students.Combined with teaching practice,the corresponding improved method is put forward,and the good result is achieved in actual teaching.%Visual Basic语言是一种基于Windows平台的,面向对象的可视化编程语言,由于其具备了直观、简单易学的特性,因此,很多大学都把VB作为非计算机专业的计算机公共基础课来讲授。本文分析了VB教学在非计算机专业学生中所普遍存在的问题,结合教学实际,提出了相应的改进方法,这种方法在笔者的实际教学中取得了较好的效果。

  9. Practice Makes Improvement: How Adults with Autism Out-Perform Others in a Naturalistic Visual Search Task

    Science.gov (United States)

    Gonzalez, Cleotilde; Martin, Jolie M.; Minshew, Nancy J.; Behrmann, Marlene

    2013-01-01

    People with autism spectrum disorder (ASD) often exhibit superior performance in visual search compared to others. However, most studies demonstrating this advantage have employed simple, uncluttered images with fully visible targets. We compare the performance of high-functioning adults with ASD and matched controls on a naturalistic luggage…

  10. Incidental Learning Speeds Visual Search by Lowering Response Thresholds, Not by Improving Efficiency: Evidence from Eye Movements

    Science.gov (United States)

    Hout, Michael C.; Goldinger, Stephen D.

    2012-01-01

    When observers search for a target object, they incidentally learn the identities and locations of "background" objects in the same display. This learning can facilitate search performance, eliciting faster reaction times for repeated displays. Despite these findings, visual search has been successfully modeled using architectures that maintain no…

  11. Google Earth Mapping Exercises for Structural Geology Students--A Promising Intervention for Improving Penetrative Visualization Ability

    Science.gov (United States)

    Giorgis, Scott

    2015-01-01

    Three-dimensional thinking skills are extremely useful for geoscientists, and at the undergraduate level, these skills are often emphasized in structural geology courses. Google Earth is a powerful tool for visualizing the three-dimensional nature of data collected on the surface of Earth. The results of a 5 y pre- and posttest study of the…

  12. Electrochemical Cell with Improved Water or Gas Management

    Science.gov (United States)

    Smith, William F. (Inventor); McElroy, James F. (Inventor); LaGrange, Jay W. (Inventor)

    2015-01-01

    An electrochemical cell having a water/gas porous separator prepared from a polymeric material and one or more conductive cell components that pass through, or are located in close proximity to, the water/gas porous separator, is provided. The inventive cell provides a high level of in-cell electrical conductivity.

  13. Cell therapy strategies and improvements for muscular dystrophy

    OpenAIRE

    Quattrocelli, Mattia; Cassano, Marco; Crippa, Stefania; Perini, Ilaria; Sampaolesi, Maurilio

    2010-01-01

    Understanding stem cell commitment and differentiation is a critical step towards clinical translation of cell therapies. In past few years, several cell types have been characterized and transplanted in animal models for different diseased tissues, eligible for a cell-mediated regeneration. Skeletal muscle damage is a challenge for cell- and gene-based therapeutical approaches, given the unique architecture of the tissue and the clinical relevance of acute damages or dystrophies. In this rev...

  14. Adult stem cells in mice : visualization and characterization using genetic mouse models

    NARCIS (Netherlands)

    Snippert, H.J.G.

    2011-01-01

    The onset of each living organism starts with pluripotent stem cells that have the ability to differentiate into all the different cell types of an organism. However, during the earliest stages of development, the pluripotent stem cells will stepwise lose their developmental potential. The cells tha

  15. WT1-specific T cell receptor gene therapy: improving TCR function in transduced T cells.

    Science.gov (United States)

    Stauss, Hans J; Thomas, Sharyn; Cesco-Gaspere, Michela; Hart, Daniel P; Xue, Shao-An; Holler, Angelika; King, Judy; Wright, Graham; Perro, Mario; Pospori, Constantina; Morris, Emma

    2008-01-01

    Adoptive transfer of antigen-specific T lymphocytes is an attractive form of immunotherapy for haematological malignancies and cancer. The difficulty of isolating antigen-specific T lymphocytes for individual patients limits the more widespread use of adoptive T cell therapy. The demonstration that cloned T cell receptor (TCR) genes can be used to produce T lymphocyte populations of desired specificity offers new opportunities for antigen-specific T cell therapy. The first trial in humans demonstrated that TCR gene-modified T cells persisted for an extended time period and reduced tumor burden in some patients. The WT1 protein is an attractive target for immunotherapy of leukemia and solid cancer since elevated expression has been demonstrated in AML, CML, MDS and in breast, colon and ovarian cancer. In the past, we have isolated high avidity CTL specific for a WT1-derived peptide presented by HLA-A2 and cloned the TCR alpha and beta genes of a WT1-specific CTL line. The genes were inserted into retroviral vectors for transduction of human peripheral blood T lymphocytes of leukemia patients and normal donors. The treatment of leukemia-bearing NOD/SCID mice with T cells transduced with the WT1-specific TCR eliminated leukemia cells in the bone marrow of most mice, while treatment with T cells transduced with a TCR of irrelevant specificity did not diminish the leukemia burden. In order to improve the safety and efficacy of TCR gene therapy, we have developed lentiviral TCR gene transfer. In addition, we employed strategies to enhance TCR expression while avoiding TCR mis-pairing. It may be possible to generate dominant TCR constructs that can suppress the expression of the endogenous TCR on the surface of transduced T cells. The development of new TCR gene constructs holds great promise for the safe and effective delivery of TCR gene therapy for the treatment of malignancies. PMID:17855129

  16. A dual-mode turn-on fluorescent BODIPY-based probe for visualization of mercury ions in living cells.

    Science.gov (United States)

    Wang, Yue; Pan, Fuchao; Zhang, Yuanlin; Peng, Fangfang; Huang, Zhentao; Zhang, Weijuan; Zhao, Weili

    2016-08-01

    A novel turn-on fluorescent 8-amino BODIPY-based probe carrying a thiourea unit as the mercury ion recognition unit has been developed. Due to the cascade reaction processes, consecutive color changes reflecting the electronic absorption and emission responses were observed upon addition of increased concentrations of mercury(ii) ions. The likely sensing mechanism was proposed as mercury ion-promoted cyclization and subsequent hydrolysis. The probe displayed a selective response to mercury ions over other metal ions. Additionally, experiments with living Human Hepatoma SMMC-7721 cells to visualize intracellular mercury ions in biological systems were carried out with the probe. PMID:27251011

  17. Ocular morphology, topography of ganglion cell distribution and visual resolution of the pilot whale (Globicephala melas)

    OpenAIRE

    Mengual Molina, Rosa María; García Irles, Magdalena; Segovia Huertas, Yolanda; Pertusa, José Francisco

    2015-01-01

    The ocular morphology, morphological characteristics and topography of ganglion cell distribution were studied in four eyes of Globicephala melas to estimate the retinal resolution. The ganglion cell layer was composed of a single row of ganglion cells with a primarily round shape and a cell size which varied from 10 to 75 µm (mean 33.5 µm) in diameter. The typical feature was that 65 % of ganglion cells had a diameter larger than 25 µm, with a similar average size in all regions of the retin...

  18. Minimal RED Cell Pairs Markedly Improve Electrode Kinetics and Power Production in Microbial Reverse Electrodialysis Cells

    KAUST Repository

    Cusick, Roland D.

    2013-12-17

    Power production from microbial reverse electrodialysis cell (MRC) electrodes is substantially improved compared to microbial fuel cells (MFCs) by using ammonium bicarbonate (AmB) solutions in multiple RED cell pair stacks and the cathode chamber. Reducing the number of RED membranes pairs while maintaining enhanced electrode performance could help to reduce capital costs. We show here that using only a single RED cell pair (CP), created by operating the cathode in concentrated AmB, dramatically increased power production normalized to cathode area from both acetate (Acetate: from 0.9 to 3.1 W/m 2-cat) and wastewater (WW: 0.3 to 1.7 W/m2), by reducing solution and charge transfer resistances at the cathode. A second RED cell pair increased RED stack potential and reduced anode charge transfer resistance, further increasing power production (Acetate: 4.2 W/m2; WW: 1.9 W/m2). By maintaining near optimal electrode power production with fewer membranes, power densities normalized to total membrane area for the 1-CP (Acetate: 3.1 W/m2-mem; WW: 1.7 W/m2) and 2-CP (Acetate: 1.3 W/m2-mem; WW: 0.6 W/m2) reactors were much higher than previous MRCs (0.3-0.5 W/m2-mem with acetate). While operating at peak power, the rate of wastewater COD removal, normalized to reactor volume, was 30-50 times higher in 1-CP and 2-CP MRCs than that in a single chamber MFC. These findings show that even a single cell pair AmB RED stack can significantly enhance electrical power production and wastewater treatment. © 2013 American Chemical Society.

  19. Visualization of cell death in mice with focal cerebral ischemia using fluorescent annexin A5, propidium iodide, and TUNEL staining.

    Science.gov (United States)

    Bahmani, Peyman; Schellenberger, Eyk; Klohs, Jan; Steinbrink, Jens; Cordell, Ryan; Zille, Marietta; Müller, Jochen; Harhausen, Denise; Hofstra, Leo; Reutelingsperger, Chris; Farr, Tracy Deanne; Dirnagl, Ulrich; Wunder, Andreas

    2011-05-01

    To monitor stroke-induced brain damage and assess neuroprotective therapies, specific imaging of cell death after cerebral ischemia in a noninvasive manner is highly desirable. Annexin A5 has been suggested as a marker for imaging cell death under various disease conditions including stroke. In this study, C57BL6/N mice received middle cerebral artery occlusion (MCAO) and were injected intravenously with either active or inactive Cy5.5-annexin A5 48 hours after reperfusion. Some mice also received propidium iodide (PI), a cell integrity marker. Only in mice receiving active Cy5.5-annexin A5 were fluorescence intensities significantly higher over the hemisphere ipsilateral to MCAO than on the contralateral side. This was detected noninvasively and ex vivo 4 and 8 hours after injection. The majority of cells positive for fluorescent annexin A5 were also positive for PI and fragmented DNA as detected by terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate-biotin nick end labeling (TUNEL) staining. This study demonstrates the high specificity of annexin A5 for visualization of cell death in a mouse model of stroke. To our knowledge, this is the first study to compare the distribution of injected active and inactive annexin A5, PI, and TUNEL staining. It provides important information on the experimental and potential clinical applications of annexin A5-based imaging agents in stroke. PMID:21245871

  20. A visual cell for measuring the solubility of prograde soluble salts in water at high temperatures and pressures

    Energy Technology Data Exchange (ETDEWEB)

    Moore, R.C.; Simonson, J.M.; Mesmer, R.E.

    1994-10-01

    An apparatus has been constructed for measuring the solubility of prograde soluble salts in water at high temperatures and pressures. The apparatus consists of a visually accessible cell thermostated in a rocking furnace. The apparatus allows for rapid, accurate solubility measurements for temperatures over 650 K and pressures up to 170 bars. The cell was constructed of platinum with sapphire windows and gold seals for corrosion resistance. A 3x telescope is used to observe the phase change in the cell. A key feature of the cell is the ability to control the system pressure. A section of small bore platinum tubing is used to connect the cell to an external pressure source. The tubing can remain open to the pressure source or be sealed off during a measurement. To minimize equilibration times, the entire apparatus was mounted to a rocking frame which can operate in the horizontal or vertical position. The apparatus was tested by measuring the solubility of NaCl in water at temperatures between 345 and 516 K at saturation pressure. Results are in good agreement with existing literature values.

  1. Balsamic Vinegar Improves High Fat-Induced Beta Cell Dysfunction via Beta Cell ABCA1

    Directory of Open Access Journals (Sweden)

    Hannah Seok

    2012-08-01

    Full Text Available BackgroundThe aim of this study was to investigate the effects of balsamic vinegar on β-cell dysfunction.MethodsIn this study, 28-week-old Otsuka Long-Evans Tokushima Fatty (OLETF rats were fed a normal chow diet or a high-fat diet (HFD and were provided with tap water or dilute balsamic vinegar for 4 weeks. Oral glucose tolerance tests and histopathological analyses were performed thereafter.ResultsIn rats fed both the both chow diet and the HFD, the rats given balsamic vinegar showed increased insulin staining in islets compared with tap water administered rats. Balsamic vinegar administration also increased β-cell ATP-binding cassette transporter subfamily A member 1 (ABCA1 expression in islets and decreased cholesterol levels.ConclusionThese findings provide the first evidence for an anti-diabetic effect of balsamic vinegar through improvement of β-cell function via increasing β-cell ABCA1 expression.

  2. Audio-Visual Biofeedback Does Not Improve the Reliability of Target Delineation Using Maximum Intensity Projection in 4-Dimensional Computed Tomography Radiation Therapy Planning

    International Nuclear Information System (INIS)

    Purpose: To investigate whether coaching patients' breathing would improve the match between ITVMIP (internal target volume generated by contouring in the maximum intensity projection scan) and ITV10 (generated by combining the gross tumor volumes contoured in 10 phases of a 4-dimensional CT [4DCT] scan). Methods and Materials: Eight patients with a thoracic tumor and 5 patients with an abdominal tumor were included in an institutional review board-approved prospective study. Patients underwent 3 4DCT scans with: (1) free breathing (FB); (2) coaching using audio-visual (AV) biofeedback via the Real-Time Position Management system; and (3) coaching via a spirometer system (Active Breathing Coordinator or ABC). One physician contoured all scans to generate the ITV10 and ITVMIP. The match between ITVMIP and ITV10 was quantitatively assessed with volume ratio, centroid distance, root mean squared distance, and overlap/Dice coefficient. We investigated whether coaching (AV or ABC) or uniform expansions (1, 2, 3, or 5 mm) of ITVMIP improved the match. Results: Although both AV and ABC coaching techniques improved frequency reproducibility and ABC improved displacement regularity, neither improved the match between ITVMIP and ITV10 over FB. On average, ITVMIP underestimated ITV10 by 19%, 19%, and 21%, with centroid distance of 1.9, 2.3, and 1.7 mm and Dice coefficient of 0.87, 0.86, and 0.88 for FB, AV, and ABC, respectively. Separate analyses indicated a better match for lung cancers or tumors not adjacent to high-intensity tissues. Uniform expansions of ITVMIP did not correct for the mismatch between ITVMIP and ITV10. Conclusions: In this pilot study, audio-visual biofeedback did not improve the match between ITVMIP and ITV10. In general, ITVMIP should be limited to lung cancers, and modification of ITVMIP in each phase of the 4DCT data set is recommended

  3. Amniotic membrane covering promotes healing of cornea epithelium and improves visual acuity after debridement for fungal keratitis

    Institute of Scientific and Technical Information of China (English)

    Bo; Zeng; Ping; Wang; Ling-Juan; Xu; Xin-Yu; Li; Hong; Zhang; Gui-Gang; Li

    2014-01-01

    AIM:To investigate the effect of amniotic membrane covering(AMC) on the healing of cornea epithelium and visual acuity for fungal keratitis after debridement.METHODS:Twenty fungal keratitis patients were divided into two groups randomly, the AMC group and the control group, ten patients each group. Both debridement of the infected cornea tissue and standard anti-fungus drugs treatments were given to every patients, monolayer amniotic membrane were sutured to the surface of the entire cornea and bulbar conjunctiva with 10-0 nylon suture for patients in the AMC group.The diameter of the ulcer was determined with slit lamp microscope and the depth of the infiltration was determined with anterior segment optical coherence tomography. Uncorrected visual acuity(UCVA) was tested before surgery and three month after healing of the epithelial layer. The healing time of the cornea epithelium, visual acuity(VA) was compared between the two groups using t- test.RESULTS:There was no statistical difference of the diameter of the ulcer, depth of the infiltration, height of the hypopyon and VA between the two groups beforesurgery(P >0.05). The average healing time of the AMC group was 6.89 ±2.98 d, which was statistically shorter than that of the control group(10.23±2.78d)(P <0.05).The average UCVA of the AMC group was 0.138 ±0.083,which was statistically better than that of the control group(0.053±0.068)(P <0.05).CONCLUSION:AMC surgery could promote healing of cornea epithelium after debridement for fungal keratitis and lead to better VA outcome.

  4. Using Immersive Visualizations to Improve Decision Making and Enhancing Public Understanding of Earth Resource and Climate Issues

    Science.gov (United States)

    Yu, K. C.; Raynolds, R. G.; Dechesne, M.

    2008-12-01

    New visualization technologies, from ArcGIS to Google Earth, have allowed for the integration of complex, disparate data sets to produce visually rich and compelling three-dimensional models of sub-surface and surface resource distribution patterns. The rendering of these models allows the public to quickly understand complicated geospatial relationships that would otherwise take much longer to explain using traditional media. We have impacted the community through topical policy presentations at both state and city levels, adult education classes at the Denver Museum of Nature and Science (DMNS), and public lectures at DMNS. We have constructed three-dimensional models from well data and surface observations which allow policy makers to better understand the distribution of groundwater in sandstone aquifers of the Denver Basin. Our presentations to local governments in the Denver metro area have allowed resource managers to better project future ground water depletion patterns, and to encourage development of alternative sources. DMNS adult education classes on water resources, geography, and regional geology, as well as public lectures on global issues such as earthquakes, tsunamis, and resource depletion, have utilized the visualizations developed from these research models. In addition to presenting GIS models in traditional lectures, we have also made use of the immersive display capabilities of the digital "fulldome" Gates Planetarium at DMNS. The real-time Uniview visualization application installed at Gates was designed for teaching astronomy, but it can be re-purposed for displaying our model datasets in the context of the Earth's surface. The 17-meter diameter dome of the Gates Planetarium allows an audience to have an immersive experience---similar to virtual reality CAVEs employed by the oil exploration industry---that would otherwise not be available to the general public. Public lectures in the dome allow audiences of over 100 people to comprehend

  5. Improved detection suggests all Merkel cell carcinomas harbor Merkel polyomavirus

    OpenAIRE

    Scott J Rodig; Cheng, Jingwei; Wardzala, Jacek; Dorosario, Andrew; Scanlon, Jessica J.; Laga, Alvaro C.; Martinez-Fernandez, Alejandro; Barletta, Justine A.; Bellizzi, Andrew M.; Sadasivam, Subhashini; Holloway, Dustin T.; Cooper, Dylan J.; Kupper, Thomas S.; Wang, Linda C; DeCaprio, James A.

    2012-01-01

    A human polyomavirus was recently discovered in Merkel cell carcinoma (MCC) specimens. The Merkel cell polyomavirus (MCPyV) genome undergoes clonal integration into the host cell chromosomes of MCC tumors and expresses small T antigen and truncated large T antigen. Previous studies have consistently reported that MCPyV can be detected in approximately 80% of all MCC tumors. We sought to increase the sensitivity of detection of MCPyV in MCC by developing antibodies capable of detecting large T...

  6. QUALITY IMPROVEMENT OF CARS BY MEANS OF FUEL CELLS UTILIZATION

    OpenAIRE

    Мілованова, В.В.

    2015-01-01

    A review of the existing types of fuel cells, their advantages and disadvantages, as well as the prospects for their use in the automotive industry has been carried out in the paper. General problems that make it difficult to launch fuel cell vehicles in series production are analyzed, some suggestions for dealing with them are proposed. Examples of application of fuel cells in cars today and a forecast of development of these technologies in the future are given.

  7. Translaminar Inhibitory Cells Recruited by Layer 6 Cortico-Thalamic Neurons Suppress Visual Cortex

    OpenAIRE

    Bortone, Dante S.; Olsen, Shawn R.; Scanziani, Massimo

    2014-01-01

    In layer 6 (L6), a principal output layer of the mammalian cerebral cortex, a population of excitatory neurons defined by the NTSR1-Cre mouse line inhibit cortical responses to visual stimuli. Here we show that of the two major types of excitatory neurons existing in L6, the NTSR1-Cre line selectively targets those whose axon innervate both cortex and thalamus and not those whose axons remain within the cortex. These cortico-thalamic neurons mediate widespread inhibition across all cortical l...

  8. Dehydroepiandrosterone inhibits cell proliferation and improves viability by regulating S phase and mitochondrial permeability in primary rat Leydig cells

    Science.gov (United States)

    LIU, LIN; WANG, DIAN; LI, LONGLONG; DING, XIAO; MA, HAITIAN

    2016-01-01

    Dehydroepiandrosterone (DHEA) is widely used as a nutritional supplement and exhibits putative anti-aging properties. However, the molecular basis of the actions of DHEA, particularly on the biological characteristics of target cells, remain unclear. The aim of the current study was to investigate the effects of DHEA on cell viability, cell proliferation, cell cycle and mitochondrial function in primary rat Leydig cells. Adult Leydig cells were purified by Percoll gradient centrifugation, and cell proliferation was detected using a Click-iT® EdU Assay kit and cell cycle assessment performed using flow cytometry. Mitochondrial membrane potential was detected using JC-1 staining assay. The results of the current study demonstrate that DHEA decreased cell proliferation in a dose-dependent manner, whereas it improved cell viability in a time-dependent and dose-dependent manner. Flow cytometry analysis demonstrated that DHEA treatment increased the S phase cell population and decreased the G2/M cell population. Cyclin A and CDK2 mRNA levels were decreased in primary rat Leydig cells following DHEA treatment. DHEA treatment decreased the transmembrane electrical gradient in primary Leydig cells, whereas treatment significantly increased succinate dehydrogenase activity. These results indicated that DHEA inhibits primary rat Leydig cell proliferation by decreasing cyclin mRNA level, whereas it improves cells viability by modulating the permeability of the mitochondrial membrane and succinate dehydrogenase activity. These findings may demonstrate an important molecular mechanism by which DHEA activity is mediated. PMID:27220727

  9. Machine-Part cell formation through visual decipherable clustering of Self Organizing Map

    OpenAIRE

    Chattopadhyay, Manojit; Chattopadhyay, Surajit; Dan, Pranab K

    2011-01-01

    Machine-part cell formation is used in cellular manufacturing in order to process a large variety, quality, lower work in process levels, reducing manufacturing lead-time and customer response time while retaining flexibility for new products. This paper presents a new and novel approach for obtaining machine cells and part families. In the cellular manufacturing the fundamental problem is the formation of part families and machine cells. The present paper deals with the Self Organising Map (...

  10. An amalgamation of 3D city models in urban air quality modelling for improving visual impact analysis

    DEFF Research Database (Denmark)

    Ujang, U.; Anton, F.; Ariffin, A.;

    2015-01-01

    Geographical Information Systems (GISs) can be seen as a common tool to map and visualize the air quality index based on geographical locations. However, in urban areas, the area resolution for air quality models is less than 2 kilometres.Since the main emissions agent in urban areas is predomina......,engineers and policy makers to design the street geometry (building height and width, green areas, pedestrian walks, roads width, etc.).......Geographical Information Systems (GISs) can be seen as a common tool to map and visualize the air quality index based on geographical locations. However, in urban areas, the area resolution for air quality models is less than 2 kilometres.Since the main emissions agent in urban areas is...... physical data input. The Level of Details (LoD) in 3D city models (i.e. LoD1 and LoD2) ascertains the potentials of implementing air quality modelling for urban areas. Therefore, this research is focused towards investigating the integration of 3D city models in air quality modelling for urban areas. The...

  11. Exploiting human memory B cell heterogeneity for improved vaccine efficacy

    Directory of Open Access Journals (Sweden)

    Noel Thomas Pauli

    2011-12-01

    Full Text Available The major goal in vaccination is establishment of long-term, prophylactic humoral memory to a pathogen. Two major components to long-lived humoral memory are plasma cells for the production of specific immunoglobulin and memory B cells that survey for their specific antigen in the periphery for later affinity maturation, proliferation, and differentiation. The study of human B cell memory has been aided by the discovery of a general marker for B cell memory, expression of CD27; however, new data suggests the existence of CD27- memory B cells as well. These recently described non-canonical memory populations have increasingly pointed to the heterogeneity of the memory compartment. The novel B memory subsets in humans appear to have unique origins, localization, and functions compared to what was considered to be a classical memory B cell. In this article, we review the known B cell memory subsets, the establishment of B cell memory in vaccination and infection, and how understanding these newly described subsets can inform vaccine design and disease treatment.

  12. Topology optimization for improving the performance of solar cells

    NARCIS (Netherlands)

    Gupta, D.K.; Langelaar, M.; Keulen, F. van; Barink, M.

    2014-01-01

    This work introduces the application of Topology Optimization (TO) to design optimal front metallization patterns for solar cells and increase their power output. A challenging aspect of the solar cell electrode design problem is the strong nonlinear relation between the active layer current and the

  13. Improved genetic manipulation of human embryonic stem cells.

    NARCIS (Netherlands)

    Braam, S.R.; Denning, C.; van den Brink, S.; Kats, P.; Hochstenbach, R.; Passier, R.; Mummery, C.L.

    2008-01-01

    Low efficiency of transfection limits the ability to genetically manipulate human embryonic stem cells (hESCs), and differences in cell derivation and culture methods require optimization of transfection protocols. We transiently transferred multiple independent hESC lines with different growth requ

  14. Improved infiltration of stem cells on electrospun nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Shabani, Iman [Polymer Engineering Department, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran, Islamic Republic of); Department of Stem Cells and Tissue Engineering, Stem Cell Technology Co. Ltd., Tehran (Iran, Islamic Republic of); Haddadi-Asl, Vahid [Polymer Engineering Department, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran (Iran, Islamic Republic of); Seyedjafari, Ehsan [Department of Biotechnology, College of Science, University of Tehran, Tehran (Iran, Islamic Republic of); Department of Stem Cells and Tissue Engineering, Stem Cell Technology Co. Ltd., Tehran (Iran, Islamic Republic of); Babaeijandaghi, Farshad [Department of Stem Cells and Tissue Engineering, Stem Cell Technology Co. Ltd., Tehran (Iran, Islamic Republic of); Faculty of Medicine, Tehran University of Medical Science, Tehran (Iran, Islamic Republic of); Soleimani, Masoud, E-mail: soleim_m@modares.ac.ir [Hematology Department, Faculty of Medical Science, Tarbiat Modares University, P.O. Box 14115-111, Tehran (Iran, Islamic Republic of)

    2009-04-24

    Nanofibrous scaffolds have been recently used in the field of tissue engineering because of their nano-size structure which promotes cell attachment, function, proliferation and infiltration. In this study, nanofibrous polyethersulfone (PES) scaffolds was prepared via electrospinning. The scaffolds were surface modified by plasma treatment and collagen grafting. The surface changes then investigated by contact angle measurements and FTIR-ATR. The results proved grafting of the collagen on nanofibers surface and increased hydrophilicity after plasma treatment and collagen grafting. The cell interaction study was done using stem cells because of their ability to differentiate to different kinds of cell lines. The cells had normal morphology on nanofibers and showed very high infiltration through collagen grafted PES nanofibers. This infiltration capability is very useful and needed to make 3D scaffolds in tissue engineering.

  15. Improved infiltration of stem cells on electrospun nanofibers

    International Nuclear Information System (INIS)

    Nanofibrous scaffolds have been recently used in the field of tissue engineering because of their nano-size structure which promotes cell attachment, function, proliferation and infiltration. In this study, nanofibrous polyethersulfone (PES) scaffolds was prepared via electrospinning. The scaffolds were surface modified by plasma treatment and collagen grafting. The surface changes then investigated by contact angle measurements and FTIR-ATR. The results proved grafting of the collagen on nanofibers surface and increased hydrophilicity after plasma treatment and collagen grafting. The cell interaction study was done using stem cells because of their ability to differentiate to different kinds of cell lines. The cells had normal morphology on nanofibers and showed very high infiltration through collagen grafted PES nanofibers. This infiltration capability is very useful and needed to make 3D scaffolds in tissue engineering.

  16. Using Cell Phones to Improve Language Skills: The Hadeda Project

    Science.gov (United States)

    Butgereit, Laurie; Botha, Adele; van Niekerk, Daniel

    Language skills are essential for education and economic development. Many countries (especially in Africa) have more than one official language and even more unofficial languages. Being able to express oneself effectively in the written word is required for tertiary education. Unfortunately, cell phones are often blamed for the degradation of language skills. There have been many studies blaming cell phone usage and instant messaging as being responsible for the the lack of language skills of children, teenagers, and young adults. Hadeda is a facility where teachers and parents can create spelling lists for pupils and children using either a cell phone or an internet based workstation. Hadeda then generates a fun and enjoyable cell phone midlet (computer program) which pupils and children can download onto their personal cell phone. Hadeda pronounces the words with electronic voices and the pupils and children can then practice their spelling on a medium they enjoy.

  17. Visualization of immediate immune responses to pioneer metastatic cells in the lung.

    Science.gov (United States)

    Headley, Mark B; Bins, Adriaan; Nip, Alyssa; Roberts, Edward W; Looney, Mark R; Gerard, Audrey; Krummel, Matthew F

    2016-03-24

    Lung metastasis is the lethal determinant in many cancers and a number of lines of evidence point to monocytes and macrophages having key roles in its development. Yet little is known about the immediate fate of incoming tumour cells as they colonize this tissue, and even less known about how they make first contact with the immune system. Primary tumours liberate circulating tumour cells (CTCs) into the blood and we have developed a stable intravital two-photon lung imaging model in mice for direct observation of the arrival of CTCs and subsequent host interaction. Here we show dynamic generation of tumour microparticles in shear flow in the capillaries within minutes of CTC entry. Rather than dispersing under flow, many of these microparticles remain attached to the lung vasculature or independently migrate along the inner walls of vessels. Using fluorescent lineage reporters and flow cytometry, we observed 'waves' of distinct myeloid cell subsets that load differentially and sequentially with this CTC-derived material. Many of these tumour-ingesting myeloid cells collectively accumulated in the lung interstitium along with the successful metastatic cells and, as previously understood, promote the development of successful metastases from surviving tumour cells. Although the numbers of these cells rise globally in the lung with metastatic exposure and ingesting myeloid cells undergo phenotypic changes associated with microparticle ingestion, a consistently sparse population of resident conventional dendritic cells, among the last cells to interact with CTCs, confer anti-metastatic protection. This work reveals that CTC fragmentation generates immune-interacting intermediates, and defines a competitive relationship between phagocyte populations for tumour loading during metastatic cell seeding. PMID:26982733

  18. Fabrication of gold nanodot arrays on a transparent substrate as a nanobioplatform for label-free visualization of living cells

    International Nuclear Information System (INIS)

    Two-dimensional gold (Au) nanodot arrays on a transparent substrate were fabricated for imaging of living cells. A nanoporous alumina mask with large-area coverage capability was prepared by a two-step chemical wet etching process after a second anodization. Highly ordered Au nanodot arrays were formed on indium-tin-oxide (ITO) glass using very thin nanoporous alumina of approximately 200 nm thickness as an evaporation mask. The large-area Au nanodot arrays on ITO glass were modified with RGD peptide (arginine; glycine; aspartic acid) containing a cysteine (Cys) residue and then used to immobilize human cancer HeLa cells, the morphology of which was observed by confocal microscopy. The confocal micrographs of living HeLa cells on Au nanodot arrays revealed enhanced contrast and resolution, which enabled discernment of cytoplasmic organelles more clearly. These results suggest that two-dimensional Au nanodot arrays modified with RGD peptide on ITO glass have potential as a biocompatible nanobioplatform for the label-free visualization and adhesion of living cells.

  19. Radionuclide Diuretic Renogram: Can Visual Interpretation of the Renal Parenchymal Transit Time and Split Renal Function Improves the Interpretation?

    International Nuclear Information System (INIS)

    Introduction: Obstructive Uropathy is a common clinical and surgical problem in many countries. The decision to intervene surgically versus medical treatment has to be supported by radiological, ultrasound, radionuclide, and urodynamic studies. Measurements of urodynamics by Whitaker test is an invasive procedure that also has limitations and requires expertise. The radionuclide diuretic renogram has many limitations and drawbacks. Unreliable results from the currently widely used programs are related to calculation of split renal function, lack of confidence in quantitative analysis of renal function parameters especially when there is retention of activity in the renal pelvis, timing of injection of Lasix, percentage of remaining functioning renal tissue, output of urine on affected side, size of the dilated pelvis and duration of obstruction. Inaccurate reports that do not reflect the true urodynamics of the obstructed kidneys and dilated renal pelvis especially after previous surgical corrections resulted in loss of confidence of the surgeons. Transit time measurements of the cortical, tubular, parenchymal and pelvis had been tried before and found to increase the accuracy of the interpretation. However, it requires complex deconvaluation analysis programs that had been clinically verified. Few institutions have access to these deconvaluation analysis programs. An alternative is visual measurement of the cortical tubular and parenchymal transit time from the diuretic renograms images, which is the subject of this presentation and the aim of a retrospective analysis of the diuretic renograms performed at St. Vincent's Medical Center, Manhattan, New York from September 2005 through December 2008. This is part of an ongoing analysis. Materials and Methods: Radionuclide renogram studies of 204 patients who underwent 253 studies with suspected obstructive uropathy (OU) were reviewed. 49 patients had repeated studies, 19 had non-functioning kidneys that were excluded

  20. Visual Literacy and Basic Design Teaching in the Visual Arts Education

    OpenAIRE

    GEMALMAYAN, Reyhan Yüksel

    2014-01-01

    This paper examines the concept of visual literacy and its relation with visual arts education. Changing values as a result of visual culture-environment relations had impact on visual arts curriculum, visual literacy and basic design education. Discusses training of and artists and visual arts teachers from the visual literacy perspective. Role of a primary school Visual Arts Course (VAC) teacher is explained in improving visual literacy of the public, and the responsibilities are questioned...

  1. Interactions of multiwalled carbon nanotubes with algal cells: quantification of association, visualization of uptake, and measurement of alterations in the composition of cells.

    Science.gov (United States)

    Rhiem, Stefan; Riding, Matthew J; Baumgartner, Werner; Martin, Francis L; Semple, Kirk T; Jones, Kevin C; Schäffer, Andreas; Maes, Hanna M

    2015-01-01

    Carbon nanotubes (CNTs) are considered promising materials in nanotechnology. We quantified CNT accumulation by the alga Desmodesmus subspicatus. Cells were exposed to radiolabeled CNTs ((14)C-CNTs;1 mg/L) to determine uptake and association, as well as elimination and dissociation in clear media.Attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) was used to detect effects of CNTs on algae. CNT-cell interactions were visualized by electron microscopy and related to alterations in their cell composition. A concentration factor of 5000 L/kg dry weight was calculated. Most of the material agglomerated around the cells, but single tubes were detected in the cytoplasm. Computational analyses of the ATR-FTIR data showed that CNT treated algae differed from controls at all sampling times.CNT exposure changed the biochemical composition of cells. The fact that CNTs are bioavailable for algae and that they influence the cell composition is important with regard to environmental risk assessment of this nanomaterial. PMID:25467692

  2. Morphological image processing operators. Reduction of partial volume effects to improve 3D visualization based on CT data

    International Nuclear Information System (INIS)

    Aim: The quality of segmentation and three-dimensional reconstruction of anatomical structures in tomographic slices is often impaired by disturbances due to partial volume effects (PVE). The potential for artefact reduction by use of the morphological image processing operators (MO) erosion and dilation is investigated. Results: For all patients under review, the artefacts caused by PVE were significantly reduced by erosion (lung: Mean SBRpre=1.67, SBRpost=4.83; brain: SBRpre=1.06, SBRpost=1.29) even with only a small number of iterations. Region dilation was applied to integrate further structures (e.g. at tumor borders) into a configurable neighbourhood for segmentation and quantitative analysis. Conclusions: The MO represent an efficient approach for the reduction of PVE artefacts in 3D-CT reconstructions and allow optimised visualization of individual objects. (orig./AJ)

  3. Noninvasive CT to Iso-C3D registration for improved intraoperative visualization in computer assisted orthopedic surgery

    Science.gov (United States)

    Rudolph, Tobias; Ebert, Lars; Kowal, Jens

    2006-03-01

    Supporting surgeons in performing minimally invasive surgeries can be considered as one of the major goals of computer assisted surgery. Excellent intraoperative visualization is a prerequisite to achieve this aim. The Siremobil Iso-C 3D has become a widely used imaging device, which, in combination with a navigation system, enables the surgeon to directly navigate within the acquired 3D image volume without any extra registration steps. However, the image quality is rather low compared to a CT scan and the volume size (approx. 12 cm 3) limits its application. A regularly used alternative in computer assisted orthopedic surgery is to use of a preoperatively acquired CT scan to visualize the operating field. But, the additional registration step, necessary in order to use CT stacks for navigation is quite invasive. Therefore the objective of this work is to develop a noninvasive registration technique. In this article a solution is being proposed that registers a preoperatively acquired CT scan to the intraoperatively acquired Iso-C 3D image volume, thereby registering the CT to the tracked anatomy. The procedure aligns both image volumes by maximizing the mutual information, an algorithm that has already been applied to similar registration problems and demonstrated good results. Furthermore the accuracy of such a registration method was investigated in a clinical setup, integrating a navigated Iso-C 3D in combination with an tracking system. Initial tests based on cadaveric animal bone resulted in an accuracy ranging from 0.63mm to 1.55mm mean error.

  4. Improved Activation toward Primary Colorectal Cancer Cells by Antigen-Specific Targeting Autologous Cytokine-Induced Killer Cells

    Directory of Open Access Journals (Sweden)

    Claudia Schlimper

    2012-01-01

    Full Text Available Adoptive therapy of malignant diseases with cytokine-induced killer (CIK cells showed promise in a number of trials; the activation of CIK cells from cancer patients towards their autologous cancer cells still needs to be improved. Here, we generated CIK cells ex vivo from blood lymphocytes of colorectal cancer patients and engineered those cells with a chimeric antigen receptor (CAR with an antibody-defined specificity for carcinoembryonic antigen (CEA. CIK cells thereby gained a new specificity as defined by the CAR and showed increase in activation towards CEA+ colon carcinoma cells, but less in presence of CEA− cells, indicated by increased secretion of proinflammatory cytokines. Redirected CIK activation was superior by CAR-mediated CD28-CD3ζ than CD3ζ signaling only. CAR-engineered CIK cells from colon carcinoma patients showed improved activation against their autologous, primary carcinoma cells from biopsies resulting in more efficient tumour cell lysis. We assume that adoptive therapy with CAR-modified CIK cells shows improved selectivity in targeting autologous tumour lesions.

  5. Shear stress-induced improvement of red blood cell deformability

    OpenAIRE

    Meram, Ece; Yılmaz, Bahar D.; Bas, Ceren; Atac, Nazlı; Yalçın, Ö.; Başkurt, Oguz K.; Meiselman, Herbert J.

    2013-01-01

    Classically, it is known that red blood cell (RBC) deformability is determined by the geometric and material properties of these cells. Experimental evidence accumulated during the last decade has introduced the concept of active regulation of RBC deformability. This regulation is mainly related to altered associations between membrane skeletal proteins and integral proteins, with the latter serving to anchor the skeleton to the lipid matrix. It has been hypothesized that shear stress induces...

  6. Improvements of visual X-ray inspection with optimized digital detector technology. Faster and more reliable inspection with High Dynamic Radiology (HDR)

    International Nuclear Information System (INIS)

    Improvements in speed and contrast resolution of Digital Detector Arrays (DDA) and significant higher power of X-Ray tubes in combination with a small focal spot open the door to an improved visual inspection of castings for automotive and aerospace applications. The result is a film-like image quality of castings in a live view. For the new image quality the x-ray parameter have to be optimized in energy and the subject contrast has to be increased to avoid that flaws are covered by the noise in the image. HDR - high dynamic radiology - expands the local contrast in the image and transfers the grey values to the range the human inspector can separate. Due to the movement in the image the inspector gets a glas-like impression of the object and the flaws allowing him to do a decision about the 3D position of a flaw in the object. (orig.)

  7. Efficiency improvement of silicon nanostructure-based solar cells

    Science.gov (United States)

    Huang, Bohr-Ran; Yang, Ying-Kan; Yang, Wen-Luh

    2014-01-01

    Solar cells based on a high-efficiency silicon nanostructure (SNS) were developed using a two-step metal-assisted electroless etching (MAEE) technique, phosphorus silicate glass (PSG) doping and screen printing. This process was used to produce solar cells with a silver nitrate (AgNO3) etching solution in different concentrations. Compared to cells produced using the single MAEE technique, SNS-based solar cells produced with the two-step MAEE technique showed an increase in silicon surface coverage of ∼181.1% and a decrease in reflectivity of ∼144.3%. The performance of the SNS-based solar cells was found to be optimized (∼11.86%) in an SNS with a length of ∼300 nm, an aspect ratio of ∼5, surface coverage of ∼84.9% and a reflectivity of ∼6.1%. The ∼16.8% increase in power conversion efficiency (PCE) for the SNS-based solar cell indicates good potential for mass production.

  8. Efficiency improvement of silicon nanostructure-based solar cells

    International Nuclear Information System (INIS)

    Solar cells based on a high-efficiency silicon nanostructure (SNS) were developed using a two-step metal-assisted electroless etching (MAEE) technique, phosphorus silicate glass (PSG) doping and screen printing. This process was used to produce solar cells with a silver nitrate (AgNO3) etching solution in different concentrations. Compared to cells produced using the single MAEE technique, SNS-based solar cells produced with the two-step MAEE technique showed an increase in silicon surface coverage of ∼181.1% and a decrease in reflectivity of ∼144.3%. The performance of the SNS-based solar cells was found to be optimized (∼11.86%) in an SNS with a length of ∼300 nm, an aspect ratio of ∼5, surface coverage of ∼84.9% and a reflectivity of ∼6.1%. The ∼16.8% increase in power conversion efficiency (PCE) for the SNS-based solar cell indicates good potential for mass production. (paper)

  9. Surface Modification of Semiconductor Photo Electrochemical Solar Cell for Improved Solar Cell Performance

    International Nuclear Information System (INIS)

    In the present paper, photo-electro chemical and hydrogen evolution characteristics of a new type of TiO2(ns) and TiO2(ns) - WO3 admixed/Ti septum based semiconductor-septum photo electrochemical (SC-SEP, PEC) solar cell have been studied. The SC-SEP cell in the configuration of SCE/1M NaOH/TiO2(ns)/Ti/H2SO4 + K2SO4/PtCE, PtWE showed the photo voltage and photo-current of 0.72 V and 8.6 mA/cm2, whereas the SC-SEP cell employing WO3 admixed TiO2(ns) photoelectrode and having the configuration: SCE/1M NaOH/TiO2(ns) - WO3/Ti/H2HO4 + K2SO4/PtCE, PtWE, showed the photo-voltage and photo-current of 0.96V and 15.6 mA/cm2 respectively. The hydrogen gas evolution for the SC - SEP cell based on TiO2/Ti photoelectrode was found to be 8.2 l/h/m2, on the other hand the WO3 modified TiO2(ns) exhibited a higher hydrogen gas evolution rate of 13.8 l/h/m2. The better performance of the new photoelectrode is thought to be due to improved spectral response and catalytic activity of WO3 for the hydrogen gas evolution kinetics. (author)

  10. VISUALIZATION OF LIP AND BASAL-CELL SKIN CANCER IN HIGH-FREQUENCY ELECTRICAL FIELD

    OpenAIRE

    Zabunyan G. A.; Ovsiyenko P. G.

    2015-01-01

    In patients, there has been registered luminescence of skin sites affected by basal cell skin cancer at stage III in high-frequency electric field. The diagnosis was confirmed by histological analysis of excised cancer sites

  11. Fluorescent Lipids: Functional Parts of Fusogenic Liposomes and Tools for Cell Membrane Labeling and Visualization

    OpenAIRE

    Christian Kleusch; Bernd Hoffmann; Nils Hersch; Agnes Csiszár; Rudolf Merkel

    2012-01-01

    In this paper a rapid and highly efficient method for controlled incorporation of fluorescent lipids into living mammalian cells is introduced. Here, the fluorescent molecules have two consecutive functions: First, they trigger rapid membrane fusion between cellular plasma membranes and the lipid bilayers of their carrier particles, so called fusogenic liposomes, and second, after insertion into cellular membranes these molecules enable fluorescence imaging of cell membranes and membrane traf...

  12. Visualization and measurement of ATP levels in living cells replicating hepatitis C virus genome RNA.

    Directory of Open Access Journals (Sweden)

    Tomomi Ando

    Full Text Available Adenosine 5'-triphosphate (ATP is the primary energy currency of all living organisms and participates in a variety of cellular processes. Although ATP requirements during viral lifecycles have been examined in a number of studies, a method by which ATP production can be monitored in real-time, and by which ATP can be quantified in individual cells and subcellular compartments, is lacking, thereby hindering studies aimed at elucidating the precise mechanisms by which viral replication energized by ATP is controlled. In this study, we investigated the fluctuation and distribution of ATP in cells during RNA replication of the hepatitis C virus (HCV, a member of the Flaviviridae family. We demonstrated that cells involved in viral RNA replication actively consumed ATP, thereby reducing cytoplasmic ATP levels. Subsequently, a method to measure ATP levels at putative subcellular sites of HCV RNA replication in living cells was developed by introducing a recently-established Förster resonance energy transfer (FRET-based ATP indicator, called ATeam, into the NS5A coding region of the HCV replicon. Using this method, we were able to observe the formation of ATP-enriched dot-like structures, which co-localize with non-structural viral proteins, within the cytoplasm of HCV-replicating cells but not in non-replicating cells. The obtained FRET signals allowed us to estimate ATP concentrations within HCV replicating cells as ∼5 mM at possible replicating sites and ∼1 mM at peripheral sites that did not appear to be involved in HCV replication. In contrast, cytoplasmic ATP levels in non-replicating Huh-7 cells were estimated as ∼2 mM. To our knowledge, this is the first study to demonstrate changes in ATP concentration within cells during replication of the HCV genome and increased ATP levels at distinct sites within replicating cells. ATeam may be a powerful tool for the study of energy metabolism during replication of the viral genome.

  13. Improving the development of early bovine somatic-cell nuclear transfer embryos by treating adult donor cells with vitamin C.

    Science.gov (United States)

    Chen, Huanhuan; Zhang, Lei; Guo, Zekun; Wang, Yongsheng; He, Rongjun; Qin, Yumin; Quan, Fusheng; Zhang, Yong

    2015-11-01

    Vitamin C (Vc) has been widely studied in cell and embryo culture, and has recently been demonstrated to promote cellular reprogramming. The objective of this study was to identify a suitable Vc concentration that, when used to treat adult bovine fibroblasts serving as donor cells for nuclear transfer, improved donor-cell physiology and the developmental potential of the cloned embryos that the donor nuclei were used to create. A Vc concentration of 0.15 mM promoted cell proliferation and increased donor-cell 5-hydroxy methyl cytosine levels 2.73-fold (P DNA methylation levels in donor cells, and improves the developmental competence of bovine somatic-cell nuclear transfer embryos. PMID:26212732

  14. Visualization of the gas flow in fuel cell bipolar plates using molecular flow seeding and micro-particle image velocimetry

    Energy Technology Data Exchange (ETDEWEB)

    Hecht, Christian; Wlokas, Irenaeus; Schulz, Christof [University of Duisburg-Essen, IVG and CeNIDE, Duisburg (Germany); Schoot, Nadine van der; Lindken, Ralph [Center for Fuel Cell Technology ZBT GmbH, Duisburg (Germany); Kronemayer, Helmut [University of Duisburg-Essen, IVG and CeNIDE, Duisburg (Germany); BASF SE, Ludwigshafen (Germany)

    2012-03-15

    Main components of proton exchange membrane fuel cells are bipolar plates that electrically connect the electrodes and provide a gas flow to the membrane. We investigate the flow in the channel structures of bipolar plates. Flow seeding is used to visualize the propagating and mixing gas stream. It is shown that a part of the gas is transported perpendicularly to the channel structure. An analysis of the diffusion compared with the convection shows different transport behavior for both flow directions. Additionally, the convective flow field is investigated in detail near the channel wall using Micro-PIV in a Reynolds-number-scaled liquid fluid system. For a more exact comparison of the experimental setups, flow seeding in both gas and liquid systems is performed. (orig.)

  15. Blockade of pathological retinal ganglion cell hyperactivity improves optogenetically evoked light responses in rd1 mice

    OpenAIRE

    John Martin Barrett; Patrick Degenaar

    2015-01-01

    Retinitis pigmentosa (RP) is a progressive retinal dystrophy that causes visual impairment and eventual blindness. Retinal prostheses are the best currently available vision-restoring treatment for RP, but only restore crude vision. One possible contributing factor to the poor quality of vision achieved with prosthetic devices is the pathological retinal ganglion cell (RGC) hyperactivity that occurs in photoreceptor dystrophic disorders. Gap junction blockade with meclofenamic acid (MFA) was ...

  16. NADPH-diaphorase activity in area 17 of the squirrel monkey visual cortex: neuropil pattern, cell morphology and laminar distribution

    Directory of Open Access Journals (Sweden)

    Franca J.G.

    1997-01-01

    Full Text Available We studied the distribution of NADPH-diaphorase activity in the visual cortex of normal adult New World monkeys (Saimiri sciureus using the malic enzyme "indirect" method. NADPH-diaphorase neuropil activity had a heterogeneous distribution. In coronal sections, it had a clear laminar pattern that was coincident with Nissl-stained layers. In tangential sections, we observed blobs in supragranular layers of V1 and stripes throughout the entire V2. We quantified and compared the tangential distribution of NADPH-diaphorase and cytochrome oxidase blobs in adjacent sections of the supragranular layers of V1. Although their spatial distributions were rather similar, the two enzymes did not always overlap. The histochemical reaction also revealed two different types of stained cells: a slightly stained subpopulation and a subgroup of deeply stained neurons resembling a Golgi impregnation. These neurons were sparsely spined non-pyramidal cells. Their dendritic arbors were very well stained but their axons were not always evident. In the gray matter, heavily stained neurons showed different dendritic arbor morphologies. However, most of the strongly reactive cells lay in the subjacent white matter, where they presented a more homogenous morphology. Our results demonstrate that the pattern of NADPH-diaphorase activity is similar to that previously described in Old World monkeys

  17. Iron labeling and pre-clinical MRI visualization of therapeutic human neural stem cells in a murine glioma model.

    Directory of Open Access Journals (Sweden)

    Mya S Thu

    Full Text Available BACKGROUND: Treatment strategies for the highly invasive brain tumor, glioblastoma multiforme, require that cells which have invaded into the surrounding brain be specifically targeted. The inherent tumor-tropism of neural stem cells (NSCs to primary and invasive tumor foci can be exploited to deliver therapeutics to invasive brain tumor cells in humans. Use of the strategy of converting prodrug to drug via therapeutic transgenes delivered by immortalized therapeutic NSC lines have shown efficacy in animal models. Thus therapeutic NSCs are being proposed for use in human brain tumor clinical trials. In the context of NSC-based therapies, MRI can be used both to non-invasively follow dynamic spatio-temporal patterns of the NSC tumor targeting allowing for the optimization of treatment strategies and to assess efficacy of the therapy. Iron-labeling of cells allows their presence to be visualized and tracked by MRI. Thus we aimed to iron-label therapeutic NSCs without affecting their cellular physiology using a method likely to gain United States Federal Drug Administration (FDA approval. METHODOLOGY: For human use, the characteristics of therapeutic Neural Stem Cells must be clearly defined with any pertubation to the cell including iron labeling requiring reanalysis of cellular physiology. Here, we studied the effect of iron-loading of the therapeutic NSCs, with ferumoxide-protamine sulfate complex (FE-Pro on viability, proliferation, migratory properties and transgene expression, when compared to non-labeled cells. FE-Pro labeled NSCs were imaged by MRI at tumor sites, after intracranial administration into the hemisphere contralateral to the tumor, in an orthotopic human glioma xenograft mouse model. CONCLUSION: FE-Pro labeled NSCs retain their proliferative status, tumor tropism, and maintain stem cell character, while allowing in vivo cellular MRI tracking at 7 Tesla, to monitor their real-time migration and distribution at brain tumor sites

  18. Cell line profiling to improve monoclonal antibody production.

    Science.gov (United States)

    Kang, Sohye; Ren, Da; Xiao, Gang; Daris, Kristi; Buck, Lynette; Enyenihi, Atim A; Zubarev, Roman; Bondarenko, Pavel V; Deshpande, Rohini

    2014-04-01

    Mammalian cell culture performance is influenced by both intrinsic (genetic) and extrinsic (media and process) factors. In this study, intrinsic capacity of various monoclonal antibody-producing Chinese Hamster Ovary (CHO) cell lines was compared by exposing them to the same culture condition. Microarray-based transcriptomics and LC-MS/MS shotgun proteomics technologies were utilized to obtain expression landscape of different cell lines. Specific transcripts and proteins correlating with productivity, growth rate and cell size have been identified. The proteomics analysis results showed a strong correlation between the intracellular protein expression levels of the recombinant DHFR and productivity. In contrast, neither the light chain nor the heavy chain of the recombinant monoclonal antibody showed correlation to productivity. Other top ranked proteins which demonstrated positive correlation to productivity included the adaptor protein complex subunits AP3D1and AP2B2, DNA repair protein DDB1 and the ER translocation complex component, SRPR. The subunits of molecular chaperone T-complex protein 1 and the regulator of mitochondrial one-carbon metabolism MTHFD2 showed negative correlation to productivity. The transcriptomics analysis has identified the regulators of calcium signaling, Tmem20 and Rcan1, as the top ranked genes displaying positive and negative correlation to productivity, respectively. For the second part of the study, the principal component analysis (PCA) was generated to view the underlying global structure of the expression data. A clear division and expression polarity was observed between the two distinct clusters of cell lines, independent of link to productivity or any other traits examined. The primary component of the PCA generated from either transcriptomics or proteomics data displayed a strong correlation to cell size and doubling time, while none of the main principal components showed correlation to productivity. Our findings suggest

  19. Visualization of the chromosome scaffold and intermediates of loop domain compaction in extracted mitotic cells.

    Science.gov (United States)

    Sheval, Eugene V; Polyakov, Vladimir Y

    2006-12-01

    A novel extraction protocol for cells cultured on coverslips is described. Observations of the extraction process in a perfusion chamber reveal that cells of all mitotic stages are not detached from coverslips during extraction, and all stages can be recognized using phase contrast images. We studied the extracted cell morphology and distribution of a major scaffold component - topoisomerase IIalpha, in extracted metaphase and anaphase cells. An extraction using 2M NaCl leads to destruction of chromosomes at the light microscope level. Immunogold studies demonstrate that the only residual structure observed is an axial chromosome scaffold that contains topoisomerase IIalpha. In contrast, mitotic chromosomes are swelled only partially after an extraction using dextran sulphate and heparin, and it appears that this treatment does not lead to total destruction of loop domains. In this case, the chromosome scaffold and numerous structures resembling small rosettes are revealed inside extracted cells. The rosettes observed condense after addition of Mg2+-ions and do not contain topoisomerase IIalpha suggesting that these structures correspond to intermediates of loop domain compaction. We propose a model of chromosome structure in which the loop domains are condensed into highly regular structures with rosette organization. PMID:17029868

  20. Fluorescent Lipids: Functional Parts of Fusogenic Liposomes and Tools for Cell Membrane Labeling and Visualization

    Directory of Open Access Journals (Sweden)

    Christian Kleusch

    2012-01-01

    Full Text Available In this paper a rapid and highly efficient method for controlled incorporation of fluorescent lipids into living mammalian cells is introduced. Here, the fluorescent molecules have two consecutive functions: First, they trigger rapid membrane fusion between cellular plasma membranes and the lipid bilayers of their carrier particles, so called fusogenic liposomes, and second, after insertion into cellular membranes these molecules enable fluorescence imaging of cell membranes and membrane traffic processes. We tested the fluorescent derivatives of the following essential membrane lipids for membrane fusion: Ceramide, sphingomyelin, phosphocholine, phosphatidylinositol-bisphosphate, ganglioside, cholesterol, and cholesteryl ester. Our results show that all probed lipids could more efficiently be incorporated into the plasma membrane of living cells than by using other methods. Moreover, labeling occurred in a gentle manner under classical cell culture conditions reducing cellular stress responses. Staining procedures were monitored by fluorescence microscopy and it was observed that sphingolipids and cholesterol containing free hydroxyl groups exhibit a decreased distribution velocity as well as a longer persistence in the plasma membrane compared to lipids without hydroxyl groups like phospholipids or other artificial lipid analogs. After membrane staining, the fluorescent molecules were sorted into membranes of cell organelles according to their chemical properties and biological functions without any influence of the delivery system.

  1. An improved algorithm for the determination of the system parameters of a visual binary by least squares

    International Nuclear Information System (INIS)

    The problem of computing the orbit of a visual binary from a set of observed positions is reconsidered. It is a least squares adjustment problem, if the observational errors follow a bias-free multivariate Gaussian distribution and the covariance matrix of the observations is assumed to be known. The condition equations are constructed to satisfy both the conic section equation and the area theorem, which are nonlinear in both the observations and the adjustment parameters. The traditional least squares algorithm, which employs condition equations that are solved with respect to the uncorrelated observations and either linear in the adjustment parameters or linearized by developing them in Taylor series by first-order approximation, is inadequate in the orbit problem. Not long ago, a completely general solution was published by W. H. Jefferys, who proposed a rigorous adjustment algorithm for models in which the observations appear nonlinearly in the condition equations and may be correlated, and in which construction of the normal equations and the residual function involves no approximation. This method was successfully applied in this problem. The normal equations were first solved by Newton's scheme. Newton's method was modified to yield a definitive solution in the case the normal approach fails, by combination with the method of steepest descent and other sophisticated algorithms. Practical examples show that the modified Newton scheme can always lead to a final solution. The weighting of observations, the orthogonal parameters and the efficiency of a set of adjustment parameters are also considered

  2. Real-time visualization of prion transport in single live cells using quantum dots

    International Nuclear Information System (INIS)

    Prion diseases are fatal neurodegenerative disorders resulting from structural conversion of the cellular isoform of PrPC to the infectious scrapie isoform PrPSc. It is believed that such structural alteration may occur within the internalization pathway. However, there is no direct evidence to support this hypothesis. Employing quantum dots (QDs) as a probe, we have recorded a real-time movie demonstrating the process of prion internalization in a living cell for the first time. The entire internalization process can be divided into four discrete but connected stages. In addition, using methyl-beta-cyclodextrin to disrupt cell membrane cholesterol, we show that lipid rafts play an important role in locating cellular PrPC to the cell membrane and in initiating PrPC endocytosis.

  3. Visualization of Water Accumulation Process in Polymer Electrolyte Fuel Cell Using Neutron Radiography

    Science.gov (United States)

    Murakawa, Hideki; Sugimoto, Katsumi; Kitamura, Nobuki; Sawada, Masataka; Asano, Hitoshi; Takenaka, Nobuyuki; Saito, Yasushi

    In order to clarify the water-accumulation phenomena in an operating polymer electrolyte fuel cell (PEFC), the water distribution in a small fuel cell was measured in the through-plane direction by using neutron radiography. The fuel cell had nine parallel channels for classifying the water-accumulation process in the gas diffusion layer (GDL) under the lands and channels. The experimental results were compared with numerical results. The water accumulation in the GDL under the lands was larger than that under the channels during the period of early PEFC operation. The difference of the water accumulation in the GDL under the land and channel was related to the water vapor. Because of the land, the vapor fraction in the GDL under the land was also higher than that under the channel. As a result, condensation was easy to occur in the GDL under the land.

  4. Real-time visualization of prion transport in single live cells using quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Kan [State Key Laboratory of Virology and Modern Virology Research Centre, College of Life Sciences, Wuhan University, Wuhan 430072 (China); Li, Shu [AIDS Research Centre, Institute of Pathogen Biology, Chinese Academy of Medical Science, Beijing 100730 (China); Xie, Min [College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072 (China); Wu, Di; Wang, WenXi; Chen, Rui; Huang, Liqin; Huang, Tao [State Key Laboratory of Virology and Modern Virology Research Centre, College of Life Sciences, Wuhan University, Wuhan 430072 (China); Pang, Daiwen, E-mail: dwpang@whu.edu.cn [College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072 (China); Xiao, Gengfu, E-mail: xiaogf@wh.iov.cn [State Key Laboratory of Virology and Modern Virology Research Centre, College of Life Sciences, Wuhan University, Wuhan 430072 (China); Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071 (China)

    2010-04-09

    Prion diseases are fatal neurodegenerative disorders resulting from structural conversion of the cellular isoform of PrP{sup C} to the infectious scrapie isoform PrP{sup Sc}. It is believed that such structural alteration may occur within the internalization pathway. However, there is no direct evidence to support this hypothesis. Employing quantum dots (QDs) as a probe, we have recorded a real-time movie demonstrating the process of prion internalization in a living cell for the first time. The entire internalization process can be divided into four discrete but connected stages. In addition, using methyl-beta-cyclodextrin to disrupt cell membrane cholesterol, we show that lipid rafts play an important role in locating cellular PrP{sup C} to the cell membrane and in initiating PrP{sup C} endocytosis.

  5. VISUALIZATION OF DYNAMIC ORGANIZATION OF CYTOSKELETON GELS IN LIVING CELLS BY HYBRID-SPM

    Institute of Scientific and Technical Information of China (English)

    K.Kawabata; Y.Sado; M.Nagayama; T.Nitta; K.Nemoto; Y.Koyama; H.Haga

    2003-01-01

    We succeeded in performing of hybrid Scanning Probe Microscopy (hybrid-SPM) in which mechanical-SPM and fluorescence microscopy are combined. This technique is able to measure simultaneously mechanical properties and distribution of cytoskeletons of living cells by using green fluorescent protein. We measured evolution of both local elasticity and distributions of actin stress fibers in an identical fibroblast living in physiological conditions. The SPM experiments revealed that stiffer lines develop in living cells, which correspond to actin stress fibers. The elasticity of the actin stress fibers is as high as 100 kPa. We discuss mechanical effects on the development of actin filament networks.

  6. Novel and improved yeast cell factories for biosustainable processes

    DEFF Research Database (Denmark)

    Workman, Mhairi

    2014-01-01

    with relevant applications as cell factories (including Pichia spp. and Yarrowia lipolytica) and other less well characterized strains (e.g. Pachysolen tannophilus). This presentation will address how we evaluate cellular performance with a view to utilizing yeast species in industrial biotechnology...

  7. Cllmodulin in tip-growing plant cells, visualized by fluorescing calmodulin-binding phenothiazines.

    Science.gov (United States)

    Haußer, I; Herth, W; Reiss, H D

    1984-09-01

    Calmodulin (CaM) was visualized light-microscopically by the fluorescent CaM inhibitors fluphenazine and chlorpromazine, both phenothiazines, during polar tip growth of pollen tubes of Lilium longiflorum, root hairs of Lepidium sativum, moss caulonema of Funaria hygrometrica, fungal hyphae of Achlya spec. and in the alga Acetabularia mediterranea, as well as during multipolar tip growth in Micrasterias denticulata. Young pollen tubes and root hairs showed tip fluorescence; at later stages and in the growing parts of the other subjects the fluorescence was almost uniform. After treatment with cytochalasin B, punctuate fluorescence occurred in the clear zone adjacent to the tip of pollen tubes. The observations indicate that there is CaM in all our tested systems detectable with this method. It may play a key role in starting polar growth. As in pollen tubes, CaM might be in part associated with the microfilament network at the tip, and thus regulate vesicle transport and cytoplasmic streaming. PMID:24253945

  8. Modular Approach for Continuous Cell-Level Balancing to Improve Performance of Large Battery Packs: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Muneed ur Rehman, M.; Evzelman, M.; Hathaway, K.; Zane, R.; Plett, G. L.; Smith, K.; Wood, E.; Maksimovic, D.

    2014-10-01

    Energy storage systems require battery cell balancing circuits to avoid divergence of cell state of charge (SOC). A modular approach based on distributed continuous cell-level control is presented that extends the balancing function to higher level pack performance objectives such as improving power capability and increasing pack lifetime. This is achieved by adding DC-DC converters in parallel with cells and using state estimation and control to autonomously bias individual cell SOC and SOC range, forcing healthier cells to be cycled deeper than weaker cells. The result is a pack with improved degradation characteristics and extended lifetime. The modular architecture and control concepts are developed and hardware results are demonstrated for a 91.2-Wh battery pack consisting of four series Li-ion battery cells and four dual active bridge (DAB) bypass DC-DC converters.

  9. Fluorescent Probes for Nucleic Acid Visualization in Fixed and Live Cells

    Directory of Open Access Journals (Sweden)

    Alexandre S. Boutorine

    2013-12-01

    Full Text Available This review analyses the literature concerning non-fluorescent and fluorescent probes for nucleic acid imaging in fixed and living cells from the point of view of their suitability for imaging intracellular native RNA and DNA. Attention is mainly paid to fluorescent probes for fluorescence microscopy imaging. Requirements for the target-binding part and the fluorophore making up the probe are formulated. In the case of native double-stranded DNA, structure-specific and sequence-specific probes are discussed. Among the latest, three classes of dsDNA-targeting molecules are described: (i sequence-specific peptides and proteins; (ii triplex-forming oligonucleotides and (iii polyamide oligo(N-methylpyrrole/N-methylimidazole minor groove binders. Polyamides seem to be the most promising targeting agents for fluorescent probe design, however, some technical problems remain to be solved, such as the relatively low sequence specificity and the high background fluorescence inside the cells. Several examples of fluorescent probe applications for DNA imaging in fixed and living cells are cited. In the case of intracellular RNA, only modified oligonucleotides can provide such sequence-specific imaging. Several approaches for designing fluorescent probes are considered: linear fluorescent probes based on modified oligonucleotide analogs, molecular beacons, binary fluorescent probes and template-directed reactions with fluorescence probe formation, FRET donor-acceptor pairs, pyrene excimers, aptamers and others. The suitability of all these methods for living cell applications is discussed.

  10. Visualizing the molecular sociology at the HeLa cell nuclear periphery

    NARCIS (Netherlands)

    Mahamid, Julia; Pfeffer, Stefan; Schaffer, Miroslava; Villa, Elizabeth; Danev, Radostin; Cuellar, Luis Kuhn; Förster, Friedrich; Hyman, Anthony A; Plitzko, Jürgen M; Baumeister, Wolfgang

    2016-01-01

    The molecular organization of eukaryotic nuclear volumes remains largely unexplored. Here we combined recent developments in cryo-electron tomography (cryo-ET) to produce three-dimensional snapshots of the HeLa cell nuclear periphery. Subtomogram averaging and classification of ribosomes revealed th

  11. Visualizing pancreatic {beta}-cell mass with [{sup 11}C]DTBZ

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, Norman Ray [Department of Radiology, Columbia University Medical School, New York, NY 10032 (United States); Souza, Fabiola [Department of Surgery, Columbia University Medical School, New York, NY 10032 (United States); Witkowski, Piotr [Department of Medicine, Columbia University Medical School, New York, NY 10032 (United States); Maffei, Antonella [Institute of Genetics and Biophysics ' Adriano Buzzati-Traverso' , CNR, Naples 80131 (Italy); Raffo, Anthony [Department of Surgery, Columbia University Medical School, New York, NY 10032 (United States); Herron, Alan [Center for Comparative Medicine and The Department of Pathology, Baylor College of Medicine, Houston, TX 77030 (United States); Kilbourn, Michael [Department of Radiology, University of Michigan, Ann Arbor, MI 48109-0638 (United States); Jurewicz, Agata [Department of Radiology, Columbia University Medical School, New York, NY 10032 (United States); Herold, Kevan [Department of Surgery, Columbia University Medical School, New York, NY 10032 (United States); Liu, Eric [Diabetes Branch, NIDDK, National Institutes of Health, Bethesda, MD 20854 (United States); Hardy, Mark Adam [Department of Medicine, Columbia University Medical School, New York, NY 10032 (United States); Van Heertum, Ronald [Department of Radiology, Columbia University Medical School, New York, NY 10032 (United States); Harris, Paul Emerson [Department of Surgery, Columbia University Medical School, New York, NY 10032 (United States)]. E-mail: peh1@columbia.edu

    2006-10-15

    {beta}-Cell mass (BCM) influences the total amount of insulin secreted, varies by individual and by the degree of insulin resistance, and is affected by physiologic and pathologic conditions. The islets of Langerhans, however, appear to have a reserve capacity of insulin secretion and, overall, assessments of insulin and blood glucose levels remain poor measures of BCM, {beta}-cell function and progression of diabetes. Thus, novel noninvasive determinations of BCM are needed to provide a quantitative endpoint for novel therapies of diabetes, islet regeneration and transplantation. Built on previous gene expression studies, we tested the hypothesis that the targeting of vesicular monoamine transporter 2 (VMAT2), which is expressed by {beta} cells, with [{sup 11}C]dihydrotetrabenazine ([{sup 11}C]DTBZ), a radioligand specific for VMAT2, and the use of positron emission tomography (PET) can provide a measure of BCM. In this report, we demonstrate decreased radioligand uptake within the pancreas of Lewis rats with streptozotocin-induced diabetes relative to their euglycemic historical controls. These studies suggest that quantitation of VMAT2 expression in {beta} cells with the use of [{sup 11}C]DTBZ and PET represents a method for noninvasive longitudinal estimates of changes in BCM that may be useful in the study and treatment of diabetes.

  12. Solid-State NMR on bacterial cells: selective cell wall signal enhancement and resolution improvement using dynamic nuclear polarization

    International Nuclear Information System (INIS)

    Dynamic nuclear polarization (DNP) enhanced solid-state nuclear magnetic resonance (NMR) has recently emerged as a powerful technique for the study of material surfaces. In this study, we demonstrate its potential to investigate cell surface in intact cells. Using Bacillus subtilis bacterial cells as an example, it is shown that the polarizing agent 1-(TEMPO-4-oxy)-3-(TEMPO-4-amino)propan-2-ol (TOTAPOL) has a strong binding affinity to cell wall polymers (peptidoglycan). This particular interaction is thoroughly investigated with a systematic study on extracted cell wall materials, disrupted cells, and entire cells, which proved that TOTAPOL is mainly accumulating in the cell wall. This property is used on one hand to selectively enhance or suppress cell wall signals by controlling radical concentrations and on the other hand to improve spectral resolution by means of a difference spectrum. Comparing DNP-enhanced and conventional solid-state NMR, an absolute sensitivity ratio of 24 was obtained on the entire cell sample. This important increase in sensitivity together with the possibility of enhancing specifically cell wall signals and improving resolution really opens new avenues for the use of DNP-enhanced solid-state NMR as an on-cell investigation tool. (authors)

  13. Audio-Visual Biofeedback Does Not Improve the Reliability of Target Delineation Using Maximum Intensity Projection in 4-Dimensional Computed Tomography Radiation Therapy Planning

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wei, E-mail: wlu@umm.edu [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland (United States); Neuner, Geoffrey A.; George, Rohini; Wang, Zhendong; Sasor, Sarah [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland (United States); Huang, Xuan [Research and Development, Care Management Department, Johns Hopkins HealthCare LLC, Glen Burnie, Maryland (United States); Regine, William F.; Feigenberg, Steven J.; D' Souza, Warren D. [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland (United States)

    2014-01-01

    Purpose: To investigate whether coaching patients' breathing would improve the match between ITV{sub MIP} (internal target volume generated by contouring in the maximum intensity projection scan) and ITV{sub 10} (generated by combining the gross tumor volumes contoured in 10 phases of a 4-dimensional CT [4DCT] scan). Methods and Materials: Eight patients with a thoracic tumor and 5 patients with an abdominal tumor were included in an institutional review board-approved prospective study. Patients underwent 3 4DCT scans with: (1) free breathing (FB); (2) coaching using audio-visual (AV) biofeedback via the Real-Time Position Management system; and (3) coaching via a spirometer system (Active Breathing Coordinator or ABC). One physician contoured all scans to generate the ITV{sub 10} and ITV{sub MIP}. The match between ITV{sub MIP} and ITV{sub 10} was quantitatively assessed with volume ratio, centroid distance, root mean squared distance, and overlap/Dice coefficient. We investigated whether coaching (AV or ABC) or uniform expansions (1, 2, 3, or 5 mm) of ITV{sub MIP} improved the match. Results: Although both AV and ABC coaching techniques improved frequency reproducibility and ABC improved displacement regularity, neither improved the match between ITV{sub MIP} and ITV{sub 10} over FB. On average, ITV{sub MIP} underestimated ITV{sub 10} by 19%, 19%, and 21%, with centroid distance of 1.9, 2.3, and 1.7 mm and Dice coefficient of 0.87, 0.86, and 0.88 for FB, AV, and ABC, respectively. Separate analyses indicated a better match for lung cancers or tumors not adjacent to high-intensity tissues. Uniform expansions of ITV{sub MIP} did not correct for the mismatch between ITV{sub MIP} and ITV{sub 10}. Conclusions: In this pilot study, audio-visual biofeedback did not improve the match between ITV{sub MIP} and ITV{sub 10}. In general, ITV{sub MIP} should be limited to lung cancers, and modification of ITV{sub MIP} in each phase of the 4DCT data set is recommended.

  14. An Improved Ghost-cell Immersed Boundary Method for Compressible Inviscid Flow Simulations

    KAUST Repository

    Chi, Cheng

    2015-05-01

    This study presents an improved ghost-cell immersed boundary approach to represent a solid body in compressible flow simulations. In contrast to the commonly used approaches, in the present work ghost cells are mirrored through the boundary described using a level-set method to farther image points, incorporating a higher-order extra/interpolation scheme for the ghost cell values. In addition, a shock sensor is in- troduced to deal with image points near the discontinuities in the flow field. Adaptive mesh refinement (AMR) is used to improve the representation of the geometry efficiently. The improved ghost-cell method is validated against five test cases: (a) double Mach reflections on a ramp, (b) supersonic flows in a wind tunnel with a forward- facing step, (c) supersonic flows over a circular cylinder, (d) smooth Prandtl-Meyer expansion flows, and (e) steady shock-induced combustion over a wedge. It is demonstrated that the improved ghost-cell method can reach the accuracy of second order in L1 norm and higher than first order in L∞ norm. Direct comparisons against the cut-cell method demonstrate that the improved ghost-cell method is almost equally accurate with better efficiency for boundary representation in high-fidelity compressible flow simulations. Implementation of the improved ghost-cell method in reacting Euler flows further validates its general applicability for compressible flow simulations.

  15. Mesenchymal stem cells improve cardiac conduction by upregulation of connexin 43 through paracrine signaling

    OpenAIRE

    Mureli, Shwetha; Gans, Christopher P.; Bare, Dan J; Geenen, David L.; Kumar, Nalin M.; Banach, Kathrin

    2012-01-01

    Mesenchymal stem cells (MSCs) were shown to improve cell survival and alleviate cardiac arrhythmias when transplanted into cardiac tissue; however, little is known about the mechanism by which MSCs modify the electrophysiological properties of cardiac tissue. We aimed to distinguish the influence of cell-cell coupling between myocytes and MSCs from that of MSC-derived paracrine factors on the spontaneous activity and conduction velocity (θ) of multicellular cardiomyocyte preparations. HL-1 ce...

  16. Research on Analysis Method of Traffic Congestion Mechanism Based on Improved Cell Transmission Model

    OpenAIRE

    Hongzhao Dong; Shuai Ma; Mingfei Guo; Dongxu Liu

    2012-01-01

    To analyze the spreading regularity of the initial traffic congestion, the improved cell transmission model (CTM) is proposed to describe the evolution mechanism of traffic congestion in regional road grid. Ordinary cells and oriented cells are applied to render the crowd roads and their adjacent roads. Therefore the traffic flow could be simulated by these cells. Resorting to the proposed model, the duration of the initial traffic congestion could be predicted and the subsequent secondary co...

  17. Transplantation of mesenchymal stem cells improves type 1 diabetes mellitus.

    Science.gov (United States)

    Li, Lisha; Li, Furong; Gao, Feng; Yang, Yali; Liu, Yuanyuan; Guo, Pingping; Li, Yulin

    2016-05-01

    Bone-marrow-derived stem cells can regenerate pancreatic tissue in a model of type 1 diabetes mellitus. Mesenchymal stem cells (MSCs) form the main part of bone marrow. We show that the intrapancreatic transplantation of MSCs elevates serum insulin and C-peptide, while decreasing blood glucose. MSCs engrafted into the damaged rat pancreas become distributed into the blood vessels, acini, ducts, and islets. Renascent islets, islet-like clusters, and a small number of MSCs expressing insulin protein have been observed in the pancreas of diabetic rats. Intrapancreatic transplantation of MSCs triggers a series of molecular and cellular events, including differentiation towards the pancreas directly and the provision of a niche to start endogenous pancreatic regeneration, which ameliorates hypoinsulinemia and hyperglycemia caused by streptozotocin. These data establish the many roles of MSCs in the restoration of the function of an injured organ. PMID:26650464

  18. Stem Cell-Based Therapeutics to Improve Wound Healing

    OpenAIRE

    Hu, Michael S.; Tripp Leavitt; Samir Malhotra; Dominik Duscher; Pollhammer, Michael S.; Walmsley, Graham G.; Zeshaan N. Maan; Alexander T. M. Cheung; Manfred Schmidt; Georg M. Huemer; Longaker, Michael T.; Peter Lorenz, H.

    2015-01-01

    Issues surrounding wound healing have garnered deep scientific interest as well as booming financial markets invested in novel wound therapies. Much progress has been made in the field, but it is unsurprising to find that recent successes reveal new challenges to be addressed. With regard to wound healing, large tissue deficits, recalcitrant wounds, and pathological scar formation remain but a few of our most pressing challenges. Stem cell-based therapies have been heralded as a promising mea...

  19. Improved assay for surface hydrophobic avidity of Candida albicans cells.

    OpenAIRE

    Hazen, K C; LeMelle, W G

    1990-01-01

    A simple method that distinguishes among hydrophobic avidity levels of highly hydrophobic isolates of the pathogenic fungus Candida albicans is described. This method involves mixing polystyrene microspheres at different concentrations with a constant concentration of yeast cells and plotting the data in accordance with the Langmuir isotherm equation. A 10-fold difference between the C. albicans isolates with the lowest and highest avidity (KH) values was found. This method may also demonstra...

  20. Improving the performance of solid oxide fuel cell systems

    OpenAIRE

    Halinen, Matias

    2015-01-01

    Solid oxide fuel cell (SOFC) systems can provide power production at a high electrical efficiency and with very low emissions. Furthermore, they retain their high electrical efficiency over a wide range of output power and offer good fuel flexibility, which makes them well suited for a range of applications. Currently SOFC systems are under investigation by researchers as well as being developed by industrial manufacturers. The first commercial SOFC systems have been on the market for some...

  1. Stem cell transplantation improves aging-related diseases

    OpenAIRE

    Ikehara, Susumu; LI Ming

    2014-01-01

    Aging is a complex process of damage accumulation, and has been viewed as experimentally and medically intractable. The number of patients with age-associated diseases such as type 2 diabetes mellitus (T2DM), osteoporosis, Alzheimer's disease (AD), Parkinson's disease, atherosclerosis, and cancer has increased recently. Aging-related diseases are related to a deficiency of the immune system, which results from an aged thymus and bone marrow cells. Intra bone marrow-bone marrow transplantation...

  2. Improvement of fitting method of multiband parameters for cell calculations

    International Nuclear Information System (INIS)

    To accurately perform cell calculations of nuclear reactors, a new fitting procedure has been developed for calculating multiband parameters, which are necessary for effective cross section calculations. By using the new fitting procedure, the error of multiband parameters becomes always zero. Reactor cell calculations have been performed to compare the effective cross sections and the infinite multiplication factors etc. calculated using the multiband parameters obtained by the new and the conventional fitting procedures by using the cross section set based on the JENDL-3.1 library with 107 energy groups. It is found that there is a small difference of the calculational results between the two fitting procedures and it is found from burnup calculations that the difference of the infinite multiplication factors is not dependent on the burnup period up to about 30 GWd/t. The onion skin effect can be exactly treated by dividing a fuel pellet to multiple regions and by using the multiband method. Thus the difference of burnup properties between two fitting procedures are investigated for the divided and the undivided fueled cells. The total inventory of Pu, Am etc. at the divided case is almost the same to the undivided case at the end of the burnup period. However it is found that the radial distribution of atomic density is slightly different between the two fitting procedures. (author)

  3. Visualizing Single Cell Biology: Nanosims Studies of Carbon and Nitrogen Metabolism in Diazotrophic Cyanobacteria

    Science.gov (United States)

    Pett-Ridge, J.; Finzi, J. A.; Capone, D. G.; Popa, R.; Nealson, K. H.; Ng, W.; Spormann, A. M.; Hutcheon, I. D.; Weber, P. K.

    2007-12-01

    Filamentous nitrogen fixing (diazotrophic) cyanobacteria are key players in global nutrient cycling, but the relationship between CO2- and N2-fixation and intercellular exchange of these elements remains poorly understood in many genera. These bacteria are faced with the challenge of isolating regions of N-fixation (O2 inhibited) and photosynthetic (O2 producing) activity. We used isotope labeling in conjunction with a high-resolution isotope and elemental mapping technique (NanoSIMS) to quantitatively describe 13C and 15N uptake and transport in two aquatic cyanobacteria grown on NaH13CO3 and 15N2. The technical challenges of tracing isotopes within individual bacteria can be overcome with high resolution Secondary Ion Mass Spectrometry (NanoSIMS). In NanoSIMS analysis, samples are sputtered with an energetic primary beam (Cs+, O-) liberating secondary ions that are separated by the mass spectrometer and detected in a suite of electron multipliers. Five isotopic species may be analyzed concurrently with spatial resolution as fine as 50nm. A high sensitivity isotope ratio 'map' can then be generated for the analyzed area. Using sequentially harvested cyanobacteria in conjunction with enriched H13CO3 and 15N2 incubations, we measured temporal enrichment patterns that evolve over the course of a day's growth and suggest tightly regulated changes in fixation kinetics. With a combination of TEM, SEM and NanoSIMS analyses, we also mapped the distribution of C, N and Mo (a critical nitrogenase co-factor) isotopes in intact cells. Our results suggest that NanoSIMS mapping of metal enzyme co-factors may be a powerful method of identifying physiological and morphological characteristics within individual bacterial cells, and could be used to provide a 3-dimensional context for more traditional analyses such as immunogold labeling. Finally, we resolved patterns of isotope enrichment at multiple spatial scales: sub-cellular variation, cell-cell differences along filaments

  4. Approaches to Optimizing Animal Cell Culture Process: Substrate Metabolism Regulation and Protein Expression Improvement

    Science.gov (United States)

    Zhang, Yuanxing

    Some high value proteins and vaccines for medical and veterinary applications by animal cell culture have an increasing market in China. In order to meet the demands of large-scale productions of proteins and vaccines, animal cell culture technology has been widely developed. In general, an animal cell culture process can be divided into two stages in a batch culture. In cell growth stage a high specific growth rate is expected to achieve a high cell density. In production stage a high specific production rate is stressed for the expression and secretion of qualified protein or replication of virus. It is always critical to maintain high cell viability in fed-batch and perfusion cultures. More concern has been focused on two points by the researchers in China. First, the cell metabolism of substrates is analyzed and the accumulation of toxic by-products is decreased through regulating cell metabolism in the culture process. Second, some important factors effecting protein expression are understood at the molecular level and the production ability of protein is improved. In pace with the rapid development of large-scale cell culture for the production of vaccines, antibodies and other recombinant proteins in China, the medium design and process optimization based on cell metabolism regulation and protein expression improvement will play an important role. The chapter outlines the main advances in metabolic regulation of cell and expression improvement of protein in animal cell culture in recent years.

  5. Can lessons designed with Gestalt laws of visual perception improve students' understanding of the phases of the moon?

    Science.gov (United States)

    Wistisen, Michele

    There has been limited success teaching elementary students about the phases of the moon using diagrams, personal observations, and manipulatives. One possible reason for this is that instruction has failed to apply Gestalt principles of perceptual organization to the lesson materials. To see if fourth grade students' understanding could be improved, four lessons were designed and taught using the Gestalt laws of Figure-Ground, Symmetry, and Similarity. Students (n = 54) who were taught lessons applying the Gestalt principles scored 12% higher on an assessment than students (n = 51) who only were taught lessons using the traditional methods. Though scores showed significant improvement, it is recommended to follow the American Association for the Advancement of Science guidelines and wait until 9th grade to instruct students about the phases.

  6. Improving speech recognition on a mobile robot platform through the use of top-down visual queues

    OpenAIRE

    Ross, Robert; O'Donoghue, R. P. S.; O'Hare, G. M. P.

    2003-01-01

    In many real-world environments, Automatic Speech Recognition (ASR) technologies fail to provide adequate performance for applications such as human robot dialog. Despite substantial evidence that speech recognition in humans is performed in a top-down as well as bottom-up manner, ASR systems typically fail to capitalize on this, instead relying on a purely statistical, bottom up methodology. In this paper we advocate the use of a knowledge based approach to improving ASR in domains such as m...

  7. Immunohistochemical visualization of neurons and specific glial cells for stereological application in the porcine neocortex

    DEFF Research Database (Denmark)

    Lyck, Lise; Jelsing, Jacob; Jensen, Pia Søndergaard;

    2006-01-01

    The pig is becoming an increasingly used non-primate model in basic experimental studies of human neurological diseases. In spite of the widespread use of immunohistochemistry and cell type specific markers, the application of immunohistochemistry in the pig brain has not been systematically...... described. Therefore, to facilitate future stereological studies of the neuronal and glial cell populations in experimental neurological diseases in the pig, we established a battery of immunohistochemical protocols for staining of perfusion fixed porcine brain tissue processed as free floating cryostat......-, vibratome- or paraffin sections. Antibodies against NeuN, GFAP, S100-protein, MBP, CNPase, CD11b, CD68 (KP1), CD45 and Ki67 were evaluated, and all except CD68 and CD45 resulted in staining of high quality in either type of tissue. Each staining was evaluated with respect to specificity and sensitivity in...

  8. Visualization of Fuel Cell Water Transport and Performance Characterization under Freezing Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kandlikar, Satish G. [Rochester Inst. of Technology, Rochester, NY (United States); Lu, Zijie [Rochester Inst. of Technology, Rochester, NY (United States); Rao, Navalgund [Rochester Inst. of Technology, Rochester, NY (United States); Sergi, Jacqueline [Rochester Inst. of Technology, Rochester, NY (United States); Rath, Cody [Rochester Inst. of Technology, Rochester, NY (United States); McDade, Christopher [Rochester Inst. of Technology, Rochester, NY (United States); Trabold, Thomas [General Motors, Honeoye Falls, NY (United States); Owejan, Jon [General Motors, Honeoye Falls, NY (United States); Gagliardo, Jeffrey [General Motors, Honeoye Falls, NY (United States); Allen, Jeffrey [Michigan Technological Univ., Houghton, MI (United States); Yassar, Reza S. [Michigan Technological Univ., Houghton, MI (United States); Medici, Ezequiel [Michigan Technological Univ., Houghton, MI (United States); Herescu, Alexandru [Michigan Technological Univ., Houghton, MI (United States)

    2010-05-30

    In this program, Rochester Institute of Technology (RIT), General Motors (GM) and Michigan Technological University (MTU) have focused on fundamental studies that address water transport, accumulation and mitigation processes in the gas diffusion layer and flow field channels of the bipolar plate. These studies have been conducted with a particular emphasis on understanding the key transport phenomena which control fuel cell operation under freezing conditions.

  9. Kinetics of linear rouleaux formation studied by visual monitoring of red cell dynamic organization.

    OpenAIRE

    Barshtein, G; Wajnblum, D; Yedgar, S

    2000-01-01

    Red blood cells (RBCs) in the presence of plasma proteins or other macromolecules may form aggregates, normally in rouleaux formations, which are dispersed with increasing blood flow. Experimental observations have suggested that the spontaneous aggregation process involves the formation of linear rouleaux (FLR) followed by formation of branched rouleaux networks. Theoretical models for the spontaneous rouleaux formation were formulated, taking into consideration that FLR may involve both "po...

  10. Dynamic visualization of dendritic cell-antigen interactions in the skin following transcutaneous immunization.

    Directory of Open Access Journals (Sweden)

    Teerawan Rattanapak

    Full Text Available Delivery of vaccines into the skin provides many advantages over traditional parenteral vaccination and is a promising approach due to the abundance of antigen presenting cells (APC residing in the skin including Langerhans cells (LC and dermal dendritic cells (DDC. However, the main obstacle for transcutaneous immunization (TCI is the effective delivery of the vaccine through the stratum corneum (SC barrier to the APC in the deeper skin layers. This study therefore utilized microneedles (MN and a lipid-based colloidal delivery system (cubosomes as a synergistic approach for the delivery of vaccines to APC in the skin. The process of vaccine uptake and recruitment by specific types of skin APC was investigated in real-time over 4 hours in B6.Cg-Tg (Itgax-EYFP 1 Mnz/J mice by two-photon microscopy. Incorporation of the vaccine into a particulate delivery system and the use of MN preferentially increased vaccine antigen uptake by a highly motile subpopulation of skin APC known as CD207⁺ DC. No uptake of antigen or any response to immunisation by LC could be detected.

  11. Organelle interactions and possible degradation pathways visualized in high-pressure frozen algal cells.

    Science.gov (United States)

    Aichinger, N; Lütz-Meindl, U

    2005-08-01

    Summary Organelle interactions, although essential for both anabolic and catabolic pathways in plant cells have not been examined in detail so far. In the present study the structure of different organelle-organelle, organelle-vesicle and organelle-membrane interactions were investigated in growing and nongrowing cells of the green alga Micrasterias denticulata by use of high pressure freeze fixation and energy filtering transmission electron microscopy. It became clear that contacts between mitochondria always occur by formation of a cone-shaped protuberance of one of the mitochondria which penetrates into its fusion partner. In the same way, structural interactions between mitochondria and mucilage vesicles and between microbodies and mucilage vesicles are achieved. Lytic compartments contact mitochondria or mucilage vesicles again by forming protuberances and by extending their contents into the respective compartment. Detached portions of mitochondria are found inside lytic compartments as a consequence of such interactions. Mitochondria found in contact with the plasma membrane reveal structural disintegration. Our study shows that interactions of organelles and vesicles are frequent events in Micrasterias cells of different ages. The interactive contacts between lytic compartments and organelles or vesicles suggest a degradation pathway different from autophagy processes described in the literature. Both the interactions between vesicles and organelles and the degradation pathways occur independently from cytoskeleton function as demonstrated by use of cytochalasin D and the microtubule inhibitor amiprophos-methyl. PMID:16159344

  12. FLIM-FRET microscopy to visualize transcription factor interactions in the nucleus of the living cell

    Science.gov (United States)

    Day, Richard N.; Demarco, Ignacio A.; Voss, Ty C.; Chen, Ye; Periasamy, Ammasi

    2004-06-01

    Wide-field fluorescence microscopy was used to monitor the co-localization of the homeodomain (HD) transcription factor Pit-1 and the basic-leucine zipper protein CCAAT/enhancer binding protein alpha (C/EBPa), each labeled with fluorescent proteins (FP) in the living cell nucleus. Fluorescence resonance energy transfer (FRET) microscopy was used to resolve the angstrom-scale spatial relationships of these expressed proteins, and the effect of a Pit-1 point mutation on the interaction with C/EBPa was characterized. Two-photon excitation fluorescence lifetime imaging microscopy (2p-FLIM) was then used as an independent method to detect these protein interactions. The excited-state lifetime for the cyan FP (CFP) labeling C/EBPa was determined, and the measurements were repeated in cells co-expressing yellow FP (YFP) labeled-proteins. The CFP lifetime was decreased in the presence of the YFP acceptor, which is consistent with donor quenching by FRET. This was verified by acceptor photobleaching, which caused a shift in the donor lifetime to that similar to the donor alone. However, a significant limitation of this technique was demonstrated by the observation that high-energy 2p-excitation resulted in CFP photobleaching and a parallel decrease in its excited-state lifetime. The key question is whether the sensitivity of this imaging approach will be sufficient to acquire significant data from living cells expressing physiological levels of the labeled proteins.

  13. Development of in-situ visualization tool for PIC simulation

    International Nuclear Information System (INIS)

    As the capability of a supercomputer is improved, the sizes of simulation and its output data also become larger and larger. Visualization is usually carried out on a researcher's PC with interactive visualization software after performing the computer simulation. However, the data size is becoming too large to do it currently. A promising answer is in-situ visualization. For this case a simulation code is coupled with the visualization code and visualization is performed with the simulation on the same supercomputer. We developed an in-situ visualization tool for particle-in-cell (PIC) simulation and it is provided as a Fortran's module. We coupled it with a PIC simulation code and tested the coupled code on Plasma Simulator supercomputer, and ensured that it works. (author)

  14. Efficiency improvement of silicon solar cells enabled by ZnO nanowhisker array coating

    OpenAIRE

    Yu, Xuegong; Wang, Dong; Lei, Dong; Li, Genhu; Yang, Deren

    2012-01-01

    An efficient antireflection coating is critical for the improvement of silicon solar cell performance via increased light coupling. Here, we have grown well-aligned ZnO nanowhisker (NW) arrays on Czochralski silicon solar cells by a seeding-growth two-step process. It is found that the ZnO NWs have a great effect on the macroscopic antireflection effect and, therefore, improves the solar cell performance. The ZnO NW array-coated solar cells display a broadband reflection suppression from 500 ...

  15. A TP-FRET-based two-photon fluorescent probe for ratiometric visualization of endogenous sulfur dioxide derivatives in mitochondria of living cells and tissues.

    Science.gov (United States)

    Yang, Xiaoguang; Zhou, Yibo; Zhang, Xiufang; Yang, Sheng; Chen, Yun; Guo, Jingru; Li, Xiaoxuan; Qing, Zhihe; Yang, Ronghua

    2016-08-11

    A ratiometric two-photon fluorescent probe for SO2 derivatives was first proposed based on acedan-merocyanine dyads via a TP-FRET strategy. It was successfully applied to visualization of the fluctuations of enzymatically generated SO2 derivatives in the mitochondria of HepG2 cells and rat liver tissues using two-photon fluorescence microscopy imaging. PMID:27469474

  16. An improved tracking technique for visual measurements of ionic polymer–metal composites (IPMC) actuators using Compute Unified Device Architecture (CUDA)

    International Nuclear Information System (INIS)

    The implementation of a real-time measurement system based on visual measurements of displacement of an actuator–cantilever is presented in this paper. This work is aimed at accelerating image processing for the fast tracking of small actuators based on ionic polymer–metal composites using the graphics processing unit (GPU) approach. The proposed processing techniques for point tracking are based on the analysis of subsequent images of the moving item. The area-segmentation approach is used which combines region prediction, successive scanning, edge filtering and match processing. The overall implementation uses the CPU and GPU, while the results achieved indicate that the computation process speeds up by more than 40×. This is a quite useful improvement especially for real-time measurement and control applications of closed-loop systems based on IPMC materials

  17. Improving solid oxide fuel cell performance by a single-step co-firing process

    Science.gov (United States)

    Dai, Hailu; Chen, Han; He, Shoucheng; Cai, Guifan; Guo, Lucun

    2015-07-01

    Solid oxide fuel cells (SOFCs) with Sm0.2Ce0.8O2-δ (SDC) as the electrolyte are successfully prepared by a single-step co-firing process with the sintering temperature as low as 1100 °C. Different from the conventional SOFC preparation procedure that involves multistep firing processes, the single-step co-firing preparation procedure simplifies the fuel cell preparation procedure and additionally improves the fuel cell performance. The cell prepared by the single-step process exhibits the maximum power density of 289 mW cm-2 at 700 °C, while the cell prepared by the conventional method is only 211 mW cm-2, with an increase of 37% been achieved. The impedance analysis reveals that the single co-firing procedure not only improves the contact between the electrolyte and electrodes, but also lowers the cell polarization resistance, thus leading to a better fuel cell performance.

  18. Improving the performance of conventional and column froth flotation cells

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, B.J. [CQ Inc., Homer City, PA (United States)

    1995-11-01

    Many existing mining operations hover on the brink of producing competitively priced fuel with marginally acceptable sulfur levels. To remain competitive, these operations need to improve the yield of their coal processing facilities, lower the sulfur content of their clean coal, or lower the ash content of their clean coal. Fine coal cleaning processes offer the best opportunity for coal producers to increase their yield of high quality product. Over 200 coal processing plants in the U.S. already employ some type of conventional or column flotation device to clean fines. an increase in efficiency in these existing circuits could be the margin required to make these coal producers competitive.

  19. Improved Flow-Field Structures for Direct Methanol Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Gurau, Bogdan

    2013-05-31

    The direct methanol fuel cell (DMFC) is ideal if high energy-density liquid fuels are required. Liquid fuels have advantages over compressed hydrogen including higher energy density and ease of handling. Although state-of-the-art DMFCs exhibit manageable degradation rates, excessive fuel crossover diminishes system energy and power density. Although use of dilute methanol mitigates crossover, the concomitant lowering of the gross fuel energy density (GFED) demands a complex balance-of-plant (BOP) that includes higher flow rates, external exhaust recirculation, etc. An alternative approach is redesign of the fuel delivery system to accommodate concentrated methanol. NuVant Systems Inc. (NuVant) will maximize the GFED by design and assembly of a DMFC that uses near neat methanol. The approach is to tune the diffusion of highly concentrated methanol (to the anode catalytic layer) to the back-diffusion of water formed at the cathode (i.e. in situ generation of dilute methanol at the anode layer). Crossover will be minimized without compromising the GFED by innovative integration of the anode flow-field and the diffusion layer. The integrated flow-field-diffusion-layers (IFDLs) will widen the current and potential DMFC operating ranges and enable the use of cathodes optimized for hydrogen-air fuel cells.

  20. Neuron analysis of visual perception

    Science.gov (United States)

    Chow, K. L.

    1980-01-01

    The receptive fields of single cells in the visual system of cat and squirrel monkey were studied investigating the vestibular input affecting the cells, and the cell's responses during visual discrimination learning process. The receptive field characteristics of the rabbit visual system, its normal development, its abnormal development following visual deprivation, and on the structural and functional re-organization of the visual system following neo-natal and prenatal surgery were also studied. The results of each individual part of each investigation are detailed.

  1. Exploring interoperability: The advancements and challenges of improving data discovery, access, and visualization of scientific data through the NOAA Earth Information System (NEIS). (Invited)

    Science.gov (United States)

    Stewart, J.; Lynge, J.; Hackathorn, E.; MacDermaid, C.; Pierce, R.; Smith, J.

    2013-12-01

    Interoperability is a complex subject and often leads to different definitions in different environments. An interoperable framework of web services can improve the user experience by providing an interface for interaction with data regardless of it's format or physical location. This in itself improves accessibility to data, fosters data exploration and use, and provides a framework for new tools and applications. With an interoperable system you have: -- Data ready for action. Services model facilitates agile response to events. Services can be combined or reused quickly, upgraded or modified independently. -- Any data available through an interoperable framework can be operated on or combined with other data. Integrating standardized formats and access. -- New and existing systems have access to wide variety of data. Any new data added is easily incorporated with minimal changes required. The possibilities are limitless. The NOAA Earth Information System (NEIS) at the Earth System Research Laboratory (ESRL) is continuing research into an interoperable framework of layered services designed to facilitate the discovery, access, integration, visualization, and understanding of all NOAA (past, present, and future) data. An underlying philosophy of NEIS is to take advantage of existing off-the-shelf technologies and standards to minimize development of custom code allowing everyone to take advantage of the framework to meet these goals above. This framework, while built by NOAA are not limited to NOAA data or applications. Any other data available through similar services or applications that understand these standards can work interchangeably. Two major challenges are under active research at ESRL are data discoverability and fast access to big data. This presentation will provide an update on development of NEIS, including these challenges, the findings, and recommendations on what is needed for an interoperable system, as well as ongoing research activities

  2. Improving therapy of chronic lymphocytic leukemia with chimeric antigen receptor T cells.

    Science.gov (United States)

    Fraietta, Joseph A; Schwab, Robert D; Maus, Marcela V

    2016-04-01

    Adoptive cell immunotherapy for the treatment of chronic lymphocytic leukemia (CLL) has heralded a new era of synthetic biology. The infusion of genetically engineered, autologous chimeric antigen receptor (CAR) T cells directed against CD19 expressed by normal and malignant B cells represents a novel approach to cancer therapy. The results of recent clinical trials of CAR T cells in relapsed and refractory CLL have demonstrated long-term disease-free remissions, underscoring the power of harnessing and redirecting the immune system against cancer. This review will briefly summarize T-cell therapies in development for CLL disease. We discuss the role of T-cell function and phenotype, T-cell culture optimization, CAR design, and approaches to potentiate the survival and anti-tumor effects of infused lymphocytes. Future efforts will focus on improving the efficacy of CAR T cells for the treatment of CLL and incorporating adoptive cell immunotherapy into standard medical management of CLL. PMID:27040708

  3. Durable, Low-cost, Improved Fuel Cell Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Chris Roger; David Mountz; Wensheng He; Tao Zhang

    2011-03-17

    The development of low cost, durable membranes and membranes electrode assemblies (MEAs) that operate under reduced relative humidity (RH) conditions remain a critical challenge for the successful introduction of fuel cells into mass markets. It was the goal of the team lead by Arkema, Inc. to address these shortages. Thus, this project addresses the following technical barriers from the fuel cells section of the Hydrogen Fuel Cells and Infrastructure Technologies Program Multi-Year Research, Development and Demonstration Plan: (A) Durability (B) Cost Arkema’s approach consisted of using blends of polyvinylidenefluoride (PVDF) and proprietary sulfonated polyelectrolytes. In the traditional approach to polyelectrolytes for proton exchange membranes (PEM), all the required properties are “packaged” in one macromolecule. The properties of interest include proton conductivity, mechanical properties, durability, and water/gas transport. This is the case, for example, for perfluorosulfonic acid-containing (PFSA) membranes. However, the cost of these materials is high, largely due to the complexity and the number of steps involved in their synthesis. In addition, they suffer other shortcomings such as mediocre mechanical properties and insufficient durability for some applications. The strength and originality of Arkema’s approach lies in the decoupling of ion conductivity from the other requirements. Kynar® PVDF provides an exceptional combination of properties that make it ideally suited for a membrane matrix (Kynar® is a registered trademark of Arkema Inc.). It exhibits outstanding chemical resistance in highly oxidative and acidic environments. In work with a prior grant, a membrane known as M41 was developed by Arkema. M41 had many of the properties needed for a high performance PEM, but had a significant deficiency in conductivity at low RH. In the first phase of this work, the processing parameters of M41 were explored as a means to increase its proton

  4. Visual agnosia.

    Science.gov (United States)

    Álvarez, R; Masjuan, J

    2016-03-01

    Visual agnosia is defined as an impairment of object recognition, in the absence of visual acuity or cognitive dysfunction that would explain this impairment. This condition is caused by lesions in the visual association cortex, sparing primary visual cortex. There are 2 main pathways that process visual information: the ventral stream, tasked with object recognition, and the dorsal stream, in charge of locating objects in space. Visual agnosia can therefore be divided into 2 major groups depending on which of the two streams is damaged. The aim of this article is to conduct a narrative review of the various visual agnosia syndromes, including recent developments in a number of these syndromes. PMID:26358494

  5. Improvement of visualization efficiency for the nondestructive inspection image of internal defects in plate type nuclear fuel

    International Nuclear Information System (INIS)

    signal processing is almost instantaneous. As a disadvantage, LIT is more sensitive to mechanic vibrations. So, in order to properly detect internal defects, several inspection parameters, such as acquisition time, processing methods, external stimulation, vibration environment etc., must be optimized when the assessment procedure is developed. If a current inspection image showing the information of internal defects is displayed on the monitor in real time, it will be helpful for the practical field application of nondestructive evaluations. For this purpose, a real time visualization technique for the detection of internal defects was developed in this paper. An active laser speckle interferometer with periodic thermal power was adopted to detect the defects. The laser speckle interferometer is sensitive to very small displacement at a resolution of nanometers by superposing the speckle patterns of two different object states. Amplitude and phase differences in deformation among intact and defective areas have been widely used for the detection of internal defects in plate specimens

  6. Reducing macrophages to improve bone marrow stromal cell survival in the contused spinal cord.

    NARCIS (Netherlands)

    Ritfeld, G.J.; Nandoe Tewarie, R.D.S.; Rahiem, S.T.; Hurtado, A.; Roos, R.A.; Grotenhuis, A.; Oudega, M.

    2010-01-01

    We tested whether reducing macrophage infiltration would improve the survival of allogeneic bone marrow stromal cells (BMSC) transplanted in the contused adult rat thoracic spinal cord. Treatment with cyclosporine, minocycline, or methylprednisolone all resulted in a significant decrease in macropha

  7. IL-12 directs further maturation of ex vivo differentiated NK cells with improved therapeutic potential.

    Directory of Open Access Journals (Sweden)

    Dorit Lehmann

    Full Text Available The possibility to modulate ex vivo human NK cell differentiation towards specific phenotypes will contribute to a better understanding of NK cell differentiation and facilitate tailored production of NK cells for immunotherapy. In this study, we show that addition of a specific low dose of IL-12 to an ex vivo NK cell differentiation system from cord blood CD34(+ stem cells will result in significantly increased proportions of cells with expression of CD62L as well as KIRs and CD16 which are preferentially expressed on mature CD56(dim peripheral blood NK cells. In addition, the cells displayed decreased expression of receptors such as CCR6 and CXCR3, which are typically expressed to a lower extent by CD56(dim than CD56(bright peripheral blood NK cells. The increased number of CD62L and KIR positive cells prevailed in a population of CD33(+NKG2A(+ NK cells, supporting that maturation occurs via this subtype. Among a series of transcription factors tested we found Gata3 and TOX to be significantly downregulated, whereas ID3 was upregulated in the IL-12-modulated ex vivo NK cells, implicating these factors in the observed changes. Importantly, the cells differentiated in the presence of IL-12 showed enhanced cytokine production and cytolytic activity against MHC class I negative and positive targets. Moreover, in line with the enhanced CD16 expression, these cells exhibited improved antibody-dependent cellular cytotoxicity for B-cell leukemia target cells in the presence of the clinically applied antibody rituximab. Altogether, these data provide evidence that IL-12 directs human ex vivo NK cell differentiation towards more mature NK cells with improved properties for potential cancer therapies.

  8. Layer- and cell-type-specific subthreshold and suprathreshold effects of long-term monocular deprivation in rat visual cortex.

    Science.gov (United States)

    Medini, Paolo

    2011-11-23

    Connectivity and dendritic properties are determinants of plasticity that are layer and cell-type specific in the neocortex. However, the impact of experience-dependent plasticity at the level of synaptic inputs and spike outputs remains unclear along vertical cortical microcircuits. Here I compared subthreshold and suprathreshold sensitivity to prolonged monocular deprivation (MD) in rat binocular visual cortex in layer 4 and layer 2/3 pyramids (4Ps and 2/3Ps) and in thick-tufted and nontufted layer 5 pyramids (5TPs and 5NPs), which innervate different extracortical targets. In normal rats, 5TPs and 2/3Ps are the most binocular in terms of synaptic inputs, and 5NPs are the least. Spike responses of all 5TPs were highly binocular, whereas those of 2/3Ps were dominated by either the contralateral or ipsilateral eye. MD dramatically shifted the ocular preference of 2/3Ps and 4Ps, mostly by depressing deprived-eye inputs. Plasticity was profoundly different in layer 5. The subthreshold ocular preference shift was sevenfold smaller in 5TPs because of smaller depression of deprived inputs combined with a generalized loss of responsiveness, and was undetectable in 5NPs. Despite their modest ocular dominance change, spike responses of 5TPs consistently lost their typically high binocularity during MD. The comparison of MD effects on 2/3Ps and 5TPs, the main affected output cells of vertical microcircuits, indicated that subthreshold plasticity is not uniquely determined by the initial degree of input binocularity. The data raise the question of whether 5TPs are driven solely by 2/3Ps during MD. The different suprathreshold plasticity of the two cell populations could underlie distinct functional deficits in amblyopia. PMID:22114282

  9. The use of Electrolyte Additives to Improve the High Temperature Resilience of Li-Ion Cells

    Science.gov (United States)

    Smart, Marshall C.; Lucht, B. L.; Ratnakumar, Bugga V.

    2007-01-01

    This viewgraph presentation reviews the use of electrolyte additves to improve the resillience of Lithium ion cells. The objective of this work is to identify lithium-ion electrolytes, which will lead to Li-ion cells with a wide operational temperature range (+60 to -60 C), and to develop Li-ion electrolytes which result in cells that display improved high temperature resilience. Significant improvement in the high temperature resilience of Li-ion cells containing these additives was observed, with the most dramatic benefit being displayed by addition of DMAc. When the electrochemical properties of the individual electrodes were analyzed, the degradation of the anode kinetics was slowed most dramatically by the incorporation of DMAc into the electrolytes. Whereas, the greatest retention in the cathode kinetics was observed in the cell containing the electrolyte with VC added.

  10. Visualization and quantification of archaeal and bacterial metabolically active cells in soil using fluorescence in situ hybridization method

    Science.gov (United States)

    Semenov, Mikhail; Manucharova, Natalia; Stepanov, Alexey

    2015-04-01

    The method of in situ hybridization using fluorescent labeled 16S rRNA-targeted oligonucleotide probes (FISH - fluorescence in situ hybridization) combines identification and quantification of groups of microorganisms at different phylogenetic levels, from domain to species. The FISH method enables to study the soil microbial community in situ, avoiding plating on nutrient media, and allows to identify and quantify living, metabolically active cells of Bacteria and Archaea. The full procedure consists of the following steps: desorption of the cells from the soil particles, fixation of cells, coating a fixed sample on the glass slide, hybridization with the specific probes and, finally, microscopic observation and cell counting. For the FISH analysis of Bacteria and Archaea, the paraformaldehyde-fixed samples were hybridized with Cy3-labeled Archaea-specific probe(Arc915) and 6-carboxyfluorescein (FAM)-labeled Bacteria-specific probe(EUB338). When a molecular probe is incorporated into a cell, it can hybridize solely with a complementary rRNA sequence. The hybridization can be visualized under the fluorescent microscope and counted. The application of FISH will be demonstrated by the abundance of metabolically active cells of Archaea and Bacteria depending on soil properties, depth and land use. The research was carried out at field and natural ecosystems of European part of Russia. Samples were collected within the soil profiles (3-6 horizons) of Chernozem and Kastanozem with distinct land use. Quantification of metabolically active cells in virgin and arable Chernozem revealed that the abundance of Archaea in topsoil of virgin Chernozem was doubled as compared with arable soil, but it leveled off in the deeper horizons. Plowing of Chernozem decreased an amount of archaeal and bacterial active cells simultaneously, however, Bacteria were more resistant to agrogenic impact than Archaea. In Kastanozem, a significant change in the abundance of metabolically active

  11. Improved Structure and Function in Autosomal Recessive Polycystic Rat Kidneys with Renal Tubular Cell Therapy.

    Directory of Open Access Journals (Sweden)

    K J Kelly

    Full Text Available Autosomal recessive polycystic kidney disease is a truly catastrophic monogenetic disease, causing death and end stage renal disease in neonates and children. Using PCK female rats, an orthologous model of autosomal recessive polycystic kidney disease harboring mutant Pkhd1, we tested the hypothesis that intravenous renal cell transplantation with normal Sprague Dawley male kidney cells would improve the polycystic kidney disease phenotype. Cytotherapy with renal cells expressing wild type Pkhd1 and tubulogenic serum amyloid A1 had powerful and sustained beneficial effects on renal function and structure in the polycystic kidney disease model. Donor cell engraftment and both mutant and wild type Pkhd1 were found in treated but not control PCK kidneys 15 weeks after the final cell infusion. To examine the mechanisms of global protection with a small number of transplanted cells, we tested the hypothesis that exosomes derived from normal Sprague Dawley cells can limit the cystic phenotype of PCK recipient cells. We found that renal exosomes originating from normal Sprague Dawley cells carried and transferred wild type Pkhd1 mRNA to PCK cells in vivo and in vitro and restricted cyst formation by cultured PCK cells. The results indicate that transplantation with renal cells containing wild type Pkhd1 improves renal structure and function in autosomal recessive polycystic kidney disease and may provide an intra-renal supply of normal Pkhd1 mRNA.

  12. Combining Concentrated Autologous Bone Marrow Stem Cells Injection With Core Decompression Improves Outcome for Patients with Early-Stage Osteonecrosis of the Femoral Head: A Comparative Study.

    Science.gov (United States)

    Tabatabaee, Reza Mostafavi; Saberi, Sadegh; Parvizi, Javad; Mortazavi, Seyed Mohammad Javad; Farzan, Mahmoud

    2015-09-01

    The management of early-stage osteonecrosis of the femoral head (ONFH) remains challenging. This study aimed to evaluate the effects of core decompression and concentrated bone marrow implantation on ONFH. The study recruited 28 hips with early ONFH randomly assigned into two groups of core decompression with (group A) and without (group B) bone marrow injection. Patients were evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire, Visual Analogue Scale (VAS) pain index, and MRI. The mean WOMAC and VAS scores in all patients improved significantly (PBone marrow stem cell injection with core decompression can be effective in early ONFH. PMID:26143238

  13. An improved ghost-cell immersed boundary method for compressible flow simulations

    KAUST Repository

    Chi, Cheng

    2016-05-20

    This study presents an improved ghost-cell immersed boundary approach to represent a solid body in compressible flow simulations. In contrast to the commonly used approaches, in the present work ghost cells are mirrored through the boundary described using a level-set method to farther image points, incorporating a higher-order extra/interpolation scheme for the ghost cell values. A sensor is introduced to deal with image points near the discontinuities in the flow field. Adaptive mesh refinement (AMR) is used to improve the representation of the geometry efficiently in the Cartesian grid system. The improved ghost-cell method is validated against four test cases: (a) double Mach reflections on a ramp, (b) smooth Prandtl-Meyer expansion flows, (c) supersonic flows in a wind tunnel with a forward-facing step, and (d) supersonic flows over a circular cylinder. It is demonstrated that the improved ghost-cell method can reach the accuracy of second order in L1 norm and higher than first order in L∞ norm. Direct comparisons against the cut-cell method demonstrate that the improved ghost-cell method is almost equally accurate with better efficiency for boundary representation in high-fidelity compressible flow simulations. Copyright © 2016 John Wiley & Sons, Ltd.

  14. ERC product improvement activities for direct fuel cell power plants

    Energy Technology Data Exchange (ETDEWEB)

    Bentley, C.; Carlson, G.; Doyon, J. [and others

    1995-08-01

    This program is designed to advance the carbonate fuel cell technology from the current power plant demonstration status to the commercial design in an approximately five-year period. The specific objectives which will allow attainment of the overall program goal are: (1) Define market-responsive power plant requirements and specifications, (2) Establish the design for a multifuel, low-cost, modular, market-responsive power plant, (3) Resolve power plant manufacturing issues and define the design for the commercial manufacturing facility, (4) Define the stack and BOP equipment packaging arrangement and define module designs, (5) Acquire capability to support developmental testing of stacks and BOP equipment as required to prepare for commercial design, and (6) Resolve stack and BOP equipment technology issues and design, build, and field test a modular commercial prototype power plant to demonstrate readiness for commercial entry. A seven-task program, dedicated to attaining objective(s) in the areas noted above, was initiated in December 1994. Accomplishments of the first six months are discussed in this paper.

  15. Design of improved fuel cell controller for distributed generation systems

    Energy Technology Data Exchange (ETDEWEB)

    Olsen Berenguer, F.A. [Instituto de Energia Electrica, Universidad Nacional de San Juan, Av. Libertador San Martin Oeste, 1109, J5400ARL San Juan (Argentina); Molina, M.G. [CONICET, Instituto de Energia Electrica, Universidad Nacional de San Juan, Av. Libertador San Martin Oeste, 1109, J5400ARL San Juan (Argentina)

    2010-06-15

    The world has been undergoing a deregulation process which allowed competition in the electricity generation sector. This situation is bringing the opportunity for electricity users to generate power by using small-scale generation systems with emerging technologies, allowing the development of distributed generation (DG). A fuel cell power plant (FCPP) is a distributed generation technology with a rapid development because it has promising characteristics, such as low pollutant emissions, silent operation, high efficiency and long lifetime because of its small number of moving parts. The power conditioning system (PCS) is the interface that allows the effective connection to the electric power system. With the appropriate topology of the PCS and its control system design, the FCPP unit is capable of simultaneously performing both instantaneous active and reactive power flow control. This paper describes the design and implementation of a novel high performance PCS of an FCPP and its controller, for applications in distributed generation systems. A full detailed model of the FCPP is derived and a new three-level control scheme is designed. The dynamic performance of the proposed system is validated by digital simulation in SimPowerSystems (SPS) of MATLAB/Simulink. (author)

  16. Visualization of transverse diffusion paths across fiber cells of the ocular lens by small animal MRI

    International Nuclear Information System (INIS)

    The sense of vision requires that light penetrate through the ocular lens. Experiments, performed and published by many research groups, have suggested that the lens, which has no blood vessels, relies on internally directed ion and water fluxes for its circulation, survival and transparency. We investigated the internal diffusive pathways of the lens in order to better understand the constraints that may be operating on directional lens fluxes. Small animal magnetic resonance imaging, including T2-weighted and diffusion tensor imaging, was used to measure tissue properties and diffusivity throughout cultured bovine lenses. A range of concentric regions of signal intensity was distinguished inside the lens, by both T2-weighted signal and mean diffusivity. Diffusivity mapping of the lens revealed novel anisotropic polar and equatorial zones of pronounced diffusivity directed transverse to the fiber cells. In contrast, an inner zone including the lens nucleus showed isotropic and weak diffusivity. Our results lend support to models of internally directed lens micro-circulation, by placing non-structural diffusive constraints on global patterns of fluid circulation

  17. Direct visualization of vaults within intact cells by electron cryo-tomography.

    Science.gov (United States)

    Woodward, Cora L; Mendonça, Luiza M; Jensen, Grant J

    2015-09-01

    The vault complex is the largest cellular ribonucleoprotein complex ever characterized and is present across diverse Eukarya. Despite significant information regarding the structure, composition and evolutionary conservation of the vault, little is know about the complex's actual biological function. To determine if intracellular vaults are morphologically similar to previously studied purified and recombinant vaults, we have used electron cryo-tomography to characterize the vault complexes found in the thin edges of primary human cells growing in tissue culture. Our studies confirm that intracellular vaults are similar in overall size and shape to purified and recombinant vaults previously analyzed. Results from subtomogram averaging indicate that densities within the vault lumen are not ordered, but randomly distributed. We also observe that vaults located in the extreme periphery of the cytoplasm predominately associate with granule-like structures and actin. Our ultrastructure studies augment existing biochemical, structural and genetic information on the vault, and provide important intracellular context for the ongoing efforts to understand the biological function of the native cytoplasmic vault. PMID:25864047

  18. Targeting HIV-1 Envelope Glycoprotein Trimers to B Cells by Using APRIL Improves Antibody Responses

    OpenAIRE

    Melchers M; Bontjer I; Tong T; Chung NP; Klasse PJ; Eggink D; Montefiori DC; Gentile M; Cerutti A; Olson WC; Berkhout B; Binley JM; Moore JP; Sanders RW

    2012-01-01

    An HIV-1 vaccine remains elusive, in part because various factors limit the quantity and quality of the antibodies raised against the viral envelope glycoprotein complex (Env). We hypothesized that targeting Env vaccines directly to B cells, by fusing them to molecules that bind and activate these cells, would improve Env-specific antibody responses. Therefore, we fused trimeric Env gp140 to A PRoliferation-Inducing Ligand (APRIL), B-cell Activating Factor (BAFF), and CD40 Ligand (CD40L). The...

  19. Efficiency Improvement of Heterojunction Polymer Photovoltaic Cells through Controlling the Morphology of the Polymer Film

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Results Polymer photovoltaic cells, which provide clean and renewable energy sources, have gained more and more attention. Polymer photovoltaic cells have the advantage of low fabrication cost and high mechanical flexibility. Polymers can be processed through a solution process, so that a homogeneous polymer film could be readily prepared in a large area. Recently, the light-to-electricity conversion efficiency of the polymer photovoltaic cells was improved significantly[1-2]. Polymer donor and organi...

  20. Improved photobiological H2 production in engineered green algal cells.

    Science.gov (United States)

    Kruse, Olaf; Rupprecht, Jens; Bader, Klaus-Peter; Thomas-Hall, Skye; Schenk, Peer Martin; Finazzi, Giovanni; Hankamer, Ben

    2005-10-01

    Oxygenic photosynthetic organisms use solar energy to split water (H2O) into protons (H+), electrons (e-), and oxygen. A select group of photosynthetic microorganisms, including the green alga Chlamydomonas reinhardtii, has evolved the additional ability to redirect the derived H+ and e- to drive hydrogen (H2) production via the chloroplast hydrogenases HydA1 and A2 (H2 ase). This process occurs under anaerobic conditions and provides a biological basis for solar-driven H2 production. However, its relatively poor yield is a major limitation for the economic viability of this process. To improve H2 production in Chlamydomonas, we have developed a new approach to increase H+ and e- supply to the hydrogenases. In a first step, mutants blocked in the state 1 transition were selected. These mutants are inhibited in cyclic e- transfer around photosystem I, eliminating possible competition for e- with H2ase. Selected strains were further screened for increased H2 production rates, leading to the isolation of Stm6. This strain has a modified respiratory metabolism, providing it with two additional important properties as follows: large starch reserves (i.e. enhanced substrate availability), and a low dissolved O2 concentration (40% of the wild type (WT)), resulting in reduced inhibition of H2ase activation. The H2 production rates of Stm6 were 5-13 times that of the control WT strain over a range of conditions (light intensity, culture time, +/- uncoupler). Typically, approximately 540 ml of H2 liter(-1) culture (up to 98% pure) were produced over a 10-14-day period at a maximal rate of 4 ml h(-1) (efficiency = approximately 5 times the WT). Stm6 therefore represents an important step toward the development of future solar-powered H2 production systems. PMID:16100118

  1. Germanium-doped carbon dots as a new type of fluorescent probe for visualizing the dynamic invasions of mercury(ii) ions into cancer cells

    Science.gov (United States)

    Yuan, Yun Huan; Li, Rong Sheng; Wang, Qiang; Wu, Zhu Lian; Wang, Jian; Liu, Hui; Huang, Cheng Zhi

    2015-10-01

    Carbon dots doped with germanium (GeCDs) were firstly prepared by a new simple 15 min carbonation synthesis route, exhibiting excitation-independent photoluminescence (PL), which could avoid autofluorescence in bioimaging applications. The as-prepared GeCDs have low cell toxicity, good biocompatibility, high intracellular delivery efficiency, stability and could be applied for detection of mercury(ii) ions with excellent selectivity in complicated medium. It is to be noted that the as-prepared GeCDs used as a new type of probe for visualization of dynamic invasions of mercury(ii) ions into Hep-2 cells display greatly different properties from most of the previously reported CDs which are regularly responsive to iron ions. All the results suggest that the GeCDs can be employed for visualization and monitoring of the significant physiological changes of living cells induced by Hg2+.Carbon dots doped with germanium (GeCDs) were firstly prepared by a new simple 15 min carbonation synthesis route, exhibiting excitation-independent photoluminescence (PL), which could avoid autofluorescence in bioimaging applications. The as-prepared GeCDs have low cell toxicity, good biocompatibility, high intracellular delivery efficiency, stability and could be applied for detection of mercury(ii) ions with excellent selectivity in complicated medium. It is to be noted that the as-prepared GeCDs used as a new type of probe for visualization of dynamic invasions of mercury(ii) ions into Hep-2 cells display greatly different properties from most of the previously reported CDs which are regularly responsive to iron ions. All the results suggest that the GeCDs can be employed for visualization and monitoring of the significant physiological changes of living cells induced by Hg2+. Electronic supplementary information (ESI) available: Experimental section and additional figures (Fig. S1-15). See DOI: 10.1039/c5nr05326a

  2. 一种实时的单目视觉SLAM改进算法%An improved real-time monocular visual SLAM algorithm

    Institute of Scientific and Technical Information of China (English)

    李全科; 曾连荪

    2015-01-01

    针对目前 SLAM 算法实时性和鲁棒性的问题,提出了一种改进的实时单目视觉 SLAM算法。该算法采用一个摄像头作为外部传感器来提取机器人行进过程中周围环境的特征信息,用实时性良好的 FAST 提取环境特征点,结合逆深度参数化进行特征点非延时初始化,用压缩扩展卡尔曼滤波更新地图。实验研究表明,该方法提高了算法的鲁棒性和实时性。%Aiming at the problem of robust SLAM algorithm, an improved real-time monocular visual SLAM algorithm is proposed. Taking a camera as its external sensor, this algorithm can obtain the feature information of the surrounding. It obtains the feature points of environment by using FAST which has good real-time capability. With the combination of inverse depth parametrization, the feature points begin to initialize without delay. The map is updated by the CEKF. The experimental study shows that this method improves the robustness and real-time of the algorithm.

  3. SYNTHESIZABLE AND PROTOTYPIC VISUAL-TACTILE SYSTEM-IN FPGA: AN ALTERNATIVE TO ANALYSIS AND IMPROVEMENT OF THE VOICE QUALITY FOR THE HEARING IMPAIRED PEOPLE

    Directory of Open Access Journals (Sweden)

    Rodrigo Leone Alves

    2016-04-01

    Full Text Available Oral communication comprises one of the most important forms of social interaction. The process of learning the spoken language depends on the hearing, therefore, the total or partial loss of hearing sensitivity hinders such aspect. Digital signal processing techniques with non-invasive character are used for diagnosis, support and improvement of the voice quality of the deaf. Thus, the present study aims to propose and develop a system of analysis and correction of vocal disorders by means of visual and tactile feedback with module implemented in programmable device type FPGA (Field Programmable Gate Array. The results point to the potential of a proposed intervention as a helper for sensory substitution, being based on the monitoring and control of speech, in order to allow for the assessment and remediation by means of an electronic resource, allowing deaf individuals to obtain a support for learning the spoken language. The possibilities for improvements in communication skills observed in this study are dependent on the capability of the device together with the speech therapist, integrating therapies with the support of the family, the time and the motivation of the user, factors that cooperate for the success of this approach.

  4. Micro-PIV (micro particle image velocimetry) visualization of red blood cells (RBCs) sucked by a female mosquito

    International Nuclear Information System (INIS)

    A mosquito's pump is a highly effective system in the small suction domain. To understand a mosquito's blood suction mechanism, we analysed the characteristics of red blood cells (RBCs) in human blood during and after suction by a female mosquito. Focussing on the flow patterns of the RBCs in human blood being sucked by a mosquito, we visualized blood flow by using a micro-particle image velocimetry (μ-PIV) system, which combines an optical microscope and a PIV method. In an ex vivo experiment, a female mosquito was supplied diluted blood at the tip of the proboscis. We examined the blood flow around the tip of the proboscis and observed that RBCs were periodically sucked towards a hole around the tip. The sucked RBCs then homogeneously flowed parallel to the inner surface of the proboscis without adhering to the wall. Furthermore, using a bioelectric recording system, we directly measured electrical signals generated during suction by the pump muscles located in the mosquito's head. We found that the electrical signal power was synchronized with the acceleration of the RBCs in the sucking phase. A histological stain method was adapted for the observation of the form and internal structure of RBCs in the mosquito. Although the blood flow analysis revealed that the RBCs underwent shear stress during suction, RBCs in the mosquito's stomach maintained their original shape

  5. Visualization study of motion and deformation of red blood cells in a microchannel with straight, divergent and convergent sections.

    Science.gov (United States)

    Chen, Bin; Guo, Fang; Xiang, Hao

    2011-09-01

    The size of red blood cells (RBC) is on the same order as the diameter of microvascular vessels. Therefore, blood should be regarded as a two-phase flow system of RBCs suspended in plasma rather than a continuous medium of microcirculation. It is of great physiological and pathological significance to investigate the effects of deformation and aggregation of RBCs on microcirculation. In this study, a visualization experiment was conducted to study the microcirculatory behavior of RBCs in suspension. Motion and deformation of RBCs in a microfluidic chip with straight, divergent, and convergent microchannel sections have been captured by microscope and high-speed camera. Meanwhile, deformation and movement of RBCs were investigated under different viscosity, hematocrit, and flow rate in this system. For low velocity and viscosity, RBCs behaved in their normal biconcave disc shape and their motion was found as a flipping motion: they not only deformed their shapes along the flow direction, but also rolled and rotated themselves. RBCs were also found to aggregate, forming rouleaux at very low flow rate and viscosity. However, for high velocity and viscosity, RBCs deformed obviously under the shear stress. They elongated along the flow direction and performed a tank-treading motion. PMID:22942486

  6. Flow visualization

    CERN Document Server

    Merzkirch, Wolfgang

    1974-01-01

    Flow Visualization describes the most widely used methods for visualizing flows. Flow visualization evaluates certain properties of a flow field directly accessible to visual perception. Organized into five chapters, this book first presents the methods that create a visible flow pattern that could be investigated by visual inspection, such as simple dye and density-sensitive visualization methods. It then deals with the application of electron beams and streaming birefringence. Optical methods for compressible flows, hydraulic analogy, and high-speed photography are discussed in other cha

  7. Improved performance in GaInNAs solar cells by hydrogen passivation

    International Nuclear Information System (INIS)

    The effect of UV-activated hydrogenation on the performance of GaInNAs solar cells is presented. A proof-of-principle investigation was performed on non-optimum GaInNAs cells, which allowed a clearer investigation of the role of passivation on the intrinsic nitrogen-related defects in these materials. Upon optimized hydrogenation of GaInNAs, a significant reduction in the presence of defect and impurity based luminescence is observed as compared to that of unpassivated reference material. This improvement in the optical properties is directly transferred to an improved performance in solar cell operation, with a more than two-fold improvement in the external quantum efficiency and short circuit current density upon hydrogenation. Temperature dependent photovoltaic measurements indicate a strong contribution of carrier localization and detrapping processes, with non-radiative processes dominating in the reference materials, and evidence for additional strong radiative losses in the hydrogenated solar cells

  8. Improved performance in GaInNAs solar cells by hydrogen passivation

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, M.; Whiteside, V. R.; Keay, J. C.; Meleco, A.; Sellers, I. R. [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St., Norman, Oklahoma 73019 (United States); Hossain, K.; Golding, T. D. [Amethyst Research Inc., 123 Case Circle, Ardmore, Oklahoma 73401 (United States); Leroux, M.; Al Khalfioui, M. [CRHEA-CNRS, Rue Bernard Gregory, Valbonne 06560 (France)

    2015-04-06

    The effect of UV-activated hydrogenation on the performance of GaInNAs solar cells is presented. A proof-of-principle investigation was performed on non-optimum GaInNAs cells, which allowed a clearer investigation of the role of passivation on the intrinsic nitrogen-related defects in these materials. Upon optimized hydrogenation of GaInNAs, a significant reduction in the presence of defect and impurity based luminescence is observed as compared to that of unpassivated reference material. This improvement in the optical properties is directly transferred to an improved performance in solar cell operation, with a more than two-fold improvement in the external quantum efficiency and short circuit current density upon hydrogenation. Temperature dependent photovoltaic measurements indicate a strong contribution of carrier localization and detrapping processes, with non-radiative processes dominating in the reference materials, and evidence for additional strong radiative losses in the hydrogenated solar cells.

  9. TRAIL protein localization in human primary T cells by 3D microscopy using 3D interactive surface plot: a new method to visualize plasma membrane.

    Science.gov (United States)

    Gras, Christophe; Smith, Nikaïa; Sengmanivong, Lucie; Gandini, Mariana; Kubelka, Claire Fernandes; Herbeuval, Jean-Philippe

    2013-01-31

    The apoptotic ligand TNF-related apoptosis ligand (TRAIL) is expressed on the membrane of immune cells during HIV infection. The intracellular stockade of TRAIL in human primary CD4(+) T cells is not known. Here we investigated whether primary CD4(+) T cells expressed TRAIL in their intracellular compartment and whether TRAIL is relocalized on the plasma membrane under HIV activation. We found that TRAIL protein was stocked in intracellular compartment in non activated CD4(+) T cells and that the total level of TRAIL protein was not increased under HIV-1 stimulation. However, TRAIL was massively relocalized on plasma membrane when cells were cultured with HIV. Using three dimensional (3D) microscopy we localized TRAIL protein in human T cells and developed a new method to visualize plasma membrane without the need of a membrane marker. This method used the 3D interactive surface plot and bright light acquired images. PMID:23085529

  10. Roles of Treg/Th17 Cell Imbalance and Neuronal Damage in the Visual Dysfunction Observed in Experimental Autoimmune Optic Neuritis Chronologically.

    Science.gov (United States)

    Liu, Yuanyuan; You, Caiyun; Zhang, Zhuhong; Zhang, Jingkai; Yan, Hua

    2015-12-01

    Optic neuritis associated with multiple sclerosis and its animal model, experimental autoimmune optic neuritis (EAON), is characterized by inflammation, T cell activation, demyelination, and neuronal damage, which might induce permanent vision loss. Elucidating the chronological relationship among the features is critical for treatment of demyelinating optic neuritis. EAON was induced in C57BL/6 mice immunized with myelin oligodendrocyte glycoprotein subcutaneously, and visual function was assessed by flash-visual evoked potential (F-VEP) at days 7, 11, 14, 19, 23, 28 post-immunization. Retinal ganglion cell (RGC) apoptosis was measured by terminal-deoxynucleotidyl transferase-mediated nick-end labeling. Demyelination and axonal damage were verified with myelin basic protein (MBP) and β-amyloid precursor protein staining, respectively. Real-time polymerase chain reaction quantified IL-17, IL-1β, TGF-β, FoxP3, IL-6, and IL-10 mRNA expression in the optic nerve, as well as FoxP3 and IL-17 staining. Systemic changes of Th17 and Treg cells were tested by flow cytometry in spleen. F-VEP latency was prolonged at 11 days and peaked at 23 days commensurate with demyelination. However, F-VEP amplitude was reduced at 11 days, preceding axon damage, and was exacerbated at 23 days when a peak in RGC apoptosis was detected. Th17 cells up-regulated as early as 7 days and peaked at 11 days, while Treg cells down-regulated inversely compared to Th17 cells change as verified by IL-17 and FoxP3 expression; spleen cell samples were slightly different, demonstrating marked changed at 14 days. Treg/Th17 cell imbalance in the optic nerve precedes and may initiate neuronal damage of axons and RGCs. These changes are commensurate with the appearances of visual dysfunction reflected in F-VEP and hence may offer a novel therapeutic avenue for vision preservation. PMID:26318182

  11. Strategies for selecting recombinant CHO cell lines for cGMP manufacturing: improving the efficiency of cell line generation.

    Science.gov (United States)

    Porter, Alison J; Racher, Andrew J; Preziosi, Richard; Dickson, Alan J

    2010-01-01

    Transfectants with a wide range of cellular phenotypes are obtained during the process of cell line generation. For the successful manufacture of a therapeutic protein, a means is required to identify a cell line with desirable growth and productivity characteristics from this phenotypically wide-ranging transfectant population. This identification process is on the critical path for first-in-human studies. We have stringently examined a typical selection strategy used to isolate cell lines suitable for cGMP manufacturing. One-hundred and seventy-five transfectants were evaluated as they progressed through the different assessment stages of the selection strategy. High producing cell lines, suitable for cGMP manufacturing, were identified. However, our analyses showed that the frequency of isolation of the highest producing cell lines was low and that ranking positions were not consistent between each assessment stage, suggesting that there is potential to improve upon the strategy. Attempts to increase the frequency of isolation of the 10 highest producing cell lines, by in silico analysis of alternative selection strategies, were unsuccessful. We identified alternative strategies with similar predictive capabilities to the typical selection strategy. One alternate strategy required fewer cell lines to be progressed at the assessment stages but the stochastic nature of the models means that cell line numbers are likely to change between programs. In summary, our studies illuminate the potential for improvement to this and future selection strategies, based around use of assessments that are more informative or that reduce variance, paving the way to improved efficiency of generation of manufacturing cell lines. PMID:20623584

  12. Visualization of the African swine fever virus infection in living cells by incorporation into the virus particle of green fluorescent protein-p54 membrane protein chimera

    International Nuclear Information System (INIS)

    Many stages of African swine fever virus infection have not yet been studied in detail. To track the behavior of African swine fever virus (ASFV) in the infected cells in real time, we produced an infectious recombinant ASFV (B54GFP-2) that expresses and incorporates into the virus particle a chimera of the p54 envelope protein fused to the enhanced green fluorescent protein (EGFP). The incorporation of the fusion protein into the virus particle was confirmed immunologically and it was determined that p54-EGFP was fully functional by confirmation that the recombinant virus made normal-sized plaques and presented similar growth curves to the wild-type virus. The tagged virus was visualized as individual fluorescent particles during the first stages of infection and allowed to visualize the infection progression in living cells through the viral life cycle by confocal microscopy. In this work, diverse potential applications of B54GFP-2 to study different aspects of ASFV infection are shown. By using this recombinant virus it was possible to determine the trajectory and speed of intracellular virus movement. Additionally, we have been able to visualize for first time the ASFV factory formation dynamics and the cytophatic effect of the virus in live infected cells. Finally, we have analyzed virus progression along the infection cycle and infected cell death as time-lapse animations

  13. Improving the Quality of the Deteriorated Regions of Multicrystalline Silicon Ingots during General Solar Cell Processes

    Institute of Scientific and Technical Information of China (English)

    WU Shan-Shan; WANG Lei; YANG De-Ren

    2011-01-01

    @@ The behavior of wafers and solar cells from the border of a multicrystalline silicon(mc-Si)ingot, which contain deteriorated regions, is investigated.It is found that the diffusion length distribution of minority carriers in the cells is uniform, and high efficiency of the solar cells(about 16%)is achieved.It is considered that the quality of the deteriorated regions could be improved to be similar to that of adjacent regions.Moreover, it is indicated that during general solar cell fabrication, phosphorus gettering and hydrogen passivation could significantly improve the quality of deteriorated regions, while aluminum gettering by RTP could not.Therefore, it is suggested that the border of a me-Si ingot could be used to fabricate high efficiency solar cells, which will increase me-Si utilization effectively.%The behavior of wafers and solar cells from the border of a multicrystalline silicon (mc-Si) ingot, which contain deteriorated regions, is investigated. It is found that the diffusion length distribution of minority carriers in the cells is uniform, and high efficiency of the solar cells (about 16%) is achieved. It is considered that the quality of the deteriorated regions could be improved to be similar to that of adjacent regions. Moreover, it is indicated that during general solar cell fabrication, phosphorus gettering and hydrogen passivation could significantly improve the quality of deteriorated regions, while aluminum gettering by RTP could not. Therefore, it is suggested that the border of a mc-Si ingot could be used to fabricate high efficiency solar cells, which will increase mc-Si utilization effectively.

  14. Cell cycle is disturbed in mucopolysaccharidosis type II fibroblasts, and can be improved by genistein.

    Science.gov (United States)

    Moskot, Marta; Gabig-Cimińska, Magdalena; Jakóbkiewicz-Banecka, Joanna; Węsierska, Magdalena; Bocheńska, Katarzyna; Węgrzyn, Grzegorz

    2016-07-01

    Mucopolysaccharidoses (MPSs) are inherited metabolic diseases caused by mutations resulting in deficiency of one of enzymes involved in degradation of glycosaminoglycans (GAGs). These compounds accumulate in cells causing their dysfunctions. Genistein is a molecule previously found to both modify GAG metabolism and modulate cell cycle. Therefore, we investigated whether the cell cycle is affected in MPS cells and if genistein can influence this process. Fibroblasts derived from patients suffering from MPS types I, II, IIIA and IIIB, as well as normal human fibroblasts (the HDFa cell line) were investigated. MTT assay was used for determination of cell proliferation, and the cell cycle was analyzed by using the MUSE® Cell Analyzer. While effects of genistein on cell proliferation were similar in both normal and MPS fibroblasts, fractions of cells in the G0/G1 phase were higher, and number of cells entering the S and G2/M phases was considerably lower in MPS II fibroblasts relative to control cells. Somewhat similar tendency, though significantly less pronounced, could be noted in MPS I, but only at longer times of incubation. However, this was not observed in MPS IIIA and MPS IIIB fibroblasts. Genistein (5, 7-dihydroxy-3-(4-hydroxyphenyl)-4H-1-benzopyran-4-one) was found to be able to partially correct the disturbances in the MPS II cell cycle, and to some extent in MPS I, at higher concentrations of this compound. The tendency to increase the fractions of cells entering the S and G2/M phases was also observed in MPS IIIA and IIIB fibroblasts treated with genistein. In conclusion, this is the first report indicating that the cell cycle can be impaired in MPS cells. The finding that genistein can improve the MPS II (and to some extent also MPS I) cell cycle provides an input to our knowledge on the molecular mechanisms of action of this compound. PMID:27016302

  15. Improved antibody production in Chinese hamster ovary cells by ATF4 overexpression

    OpenAIRE

    Haredy, Ahmad M.; Nishizawa, Akitoshi; Honda, Kohsuke; Ohya, Tomoshi; Ohtake, Hisao; Omasa, Takeshi

    2013-01-01

    To improve antibody production in Chinese hamster ovary (CHO) cells, the humanized antibody-producing CHO DP-12-SF cell line was transfected with the gene encoding activating transcription factor 4 (ATF4), a central factor in the unfolded protein response. Overexpression of ATF4 significantly enhanced the production of antibody in the CHO DP-12-SF cell line. The specific IgG production rate of in the ATF4-overexpressing CHO-ATF4-16 cells was approximately 2.4 times that of the parental host c...

  16. Improving expression of recombinant human IGF-1 using IGF-1R knockout CHO cell lines.

    Science.gov (United States)

    Romand, Sandrine; Jostock, Thomas; Fornaro, Mara; Schmidt, Joerg; Ritter, Anett; Wilms, Burkhard; Laux, Holger

    2016-05-01

    Chinese Hamster Ovary (CHO) cells are widely used for the large-scale production of recombinant biopharmaceuticals. However, attempts to express IGF-1 (a mutated human Insulin-like growth factor 1 Ea peptide (hIGF-1Ea mut)) in CHO cells resulted in poor cell growth and low productivity (0.1-0.2 g/L). Human IGF-1 variants negatively impacted CHO cell growth via the IGF-1 receptor (IGF-1R). Therefore knockout (KO) of the IGF-1R gene in two different CHO cell lines as well as knockdown (KD) of IGF-1R in one CHO cell line were performed. These cell line engineering approaches decreased significantly the hIGF-1 mediated cell growth inhibition and increased productivity of both KO CHO cell lines as well as of the KD CHO cell line. A productivity increase of 10-fold at pool level and sevenfold at clone level was achieved, resulting in a titer of 1.3 g/L. This data illustrate that cell line engineering approaches are powerful tools to improve the yields of recombinant proteins which are difficult to produce in CHO cells. Biotechnol. Bioeng. 2016;113: 1094-1101. © 2015 Wiley Periodicals, Inc. PMID:26523469

  17. Restoration of visual function by expression of a light-gated mammalian ion channel in retinal ganglion cells or ON-bipolar cells.

    Science.gov (United States)

    Gaub, Benjamin M; Berry, Michael H; Holt, Amy E; Reiner, Andreas; Kienzler, Michael A; Dolgova, Natalia; Nikonov, Sergei; Aguirre, Gustavo D; Beltran, William A; Flannery, John G; Isacoff, Ehud Y

    2014-12-23

    Most inherited forms of blindness are caused by mutations that lead to photoreceptor cell death but spare second- and third-order retinal neurons. Expression of the light-gated excitatory mammalian ion channel light-gated ionotropic glutamate receptor (LiGluR) in retinal ganglion cells (RGCs) of the retina degeneration (rd1) mouse model of blindness was previously shown to restore some visual functions when stimulated by UV light. Here, we report restored retinal function in visible light in rodent and canine models of blindness through the use of a second-generation photoswitch for LiGluR, maleimide-azobenzene-glutamate 0 with peak efficiency at 460 nm (MAG0(460)). In the blind rd1 mouse, multielectrode array recordings of retinal explants revealed robust and uniform light-evoked firing when LiGluR-MAG0(460) was targeted to RGCs and robust but diverse activity patterns in RGCs when LiGluR-MAG0(460) was targeted to ON-bipolar cells (ON-BCs). LiGluR-MAG0(460) in either RGCs or ON-BCs of the rd1 mouse reinstated innate light-avoidance behavior and enabled mice to distinguish between different temporal patterns of light in an associative learning task. In the rod-cone dystrophy dog model of blindness, LiGluR-MAG0(460) in RGCs restored robust light responses to retinal explants and intravitreal delivery of LiGluR and MAG0(460) was well tolerated in vivo. The results in both large and small animal models of photoreceptor degeneration provide a path to clinical translation. PMID:25489083

  18. Enhanced Erbium-Doped Ceria Nanostructure Coating to Improve Solar Cell Performance

    Directory of Open Access Journals (Sweden)

    Nader Shehata

    2015-11-01

    Full Text Available This paper discusses the effect of adding reduced erbium-doped ceria nanoparticles (REDC NPs as a coating on silicon solar cells. Reduced ceria nanoparticles doped with erbium have the advantages of both improving conductivity and optical conversion of solar cells. Oxygen vacancies in ceria nanoparticles reduce Ce4+ to Ce3+ which follow the rule of improving conductivity of solar cells through the hopping mechanism. The existence of Ce3+ helps in the down-conversion from 430 nm excitation to 530 nm emission. The erbium dopant forms energy levels inside the low-phonon ceria host to up-convert the 780 nm excitations into green and red emissions. When coating reduced erbium-doped ceria nanoparticles on the back side of a solar cell, a promising improvement in the solar cell efficiency has been observed from 15% to 16.5% due to the mutual impact of improved electric conductivity and multi-optical conversions. Finally, the impact of the added coater on the electric field distribution inside the solar cell has been studied.

  19. THE IMPROVEMENT OF INFARCTED MYOCARDIAL CONTRACTILE FORCE AFTER AUTOLOGOUS SKELETAL MUSCLE SATELLITE CELL IMPLANTATION

    Institute of Scientific and Technical Information of China (English)

    钟竑; 朱洪生; 张臻

    2002-01-01

    Objective To study the improvement of infarcted myocardial contractile force after autologous skeletal muscle satellite cell implantation via intracoronary arterial perfusion. Methods Skeletal muscle cells were harvested from gluteus max of adult mongrel dogs and the cells were cultured and expanded before being labeled with DAPI (4, 6-diamidino-2-phenylindone). The labeled cells were then implanted into the acute myocardial infarct site via the ligated left anterior descending (LAD) coronary artery. Specimens were taken at 2nd, 4th, 8th week after myoblast implantation for histologic and contractile force evaluation, respectively. Results The satellite cells with fluorescence had been observed in the infarct site and also in papi-llary muscle with consistent oriented direction of host myocardium. A portion of the implanted cells had differen-tiated into muscle fibers. Two weeks after implantation, the myocardial contractile force showed no significant difference between the cell implant group and control group. At 4 and 8 week, the contractile force in the cell implant group was better than that in control group. Conclusion The skeletal muscle satellite cells, implanted into infarct myocardium by intracoronary arterial perfusion, could disseminate through the entire infarcted zone with myocardial regeneration and improve the contractile function of the infarcted myocardium.

  20. Liposomal Nanomedicine with Short Chain Sphingolipids Modulate Tumor Cell Membrane Permeability Modulate Tumor Cell Membrane Permeability and Improve Chemotherapy

    NARCIS (Netherlands)

    L.R.C. Pedrosa (Lília R. Cordeiro)

    2014-01-01

    markdownabstract__Abstract__ Chapter 6 discusses the significance of the results described in this thesis and future perspectives. The main goal of the thesis was the application of SCS enriched liposomes to improve chemotherapy outcome, by enhancing drug bioavailability in target tumor cells. De

  1. Hydrophobic Organic Hole Transporters for Improved Moisture Resistance in Metal Halide Perovskite Solar Cells.

    Science.gov (United States)

    Leijtens, Tomas; Giovenzana, Tommaso; Habisreutinger, Severin N; Tinkham, Jonathan S; Noel, Nakita K; Kamino, Brett A; Sadoughi, Golnaz; Sellinger, Alan; Snaith, Henry J

    2016-03-01

    Solar cells based on organic-inorganic perovskite semiconductor materials have recently made rapid improvements in performance, with the best cells performing at over 20% efficiency. With such rapid progress, questions such as cost and solar cell stability are becoming increasingly important to address if this new technology is to reach commercial deployment. The moisture sensitivity of commonly used organic-inorganic metal halide perovskites has especially raised concerns. Here, we demonstrate that the hygroscopic lithium salt commonly used as a dopant for the hole transport material in perovskite solar cells makes the top layer of the devices hydrophilic and causes the solar cells to rapidly degrade in the presence of moisture. By using novel, low cost, and hydrophobic hole transporters in conjunction with a doping method incorporating a preoxidized salt of the respective hole transporters, we are able to prepare efficient perovskite solar cells with greatly enhanced water resistance. PMID:26859777

  2. Improving clinical examination in acute tibial fractures by enhancing visual cues: the case for always 'cutting back' a tibial back-slab and marking the dorsalis pedis pulse.

    Science.gov (United States)

    Thomas, Alasdair; Kimber, Cheryl; Bramwell, Donald; Jaarsma, Ruurd

    2016-08-01

    Look, feel, move is a simple and widely taught sequence to be followed when undertaking a clinical examination in orthopaedics (Maher et al., 1994; McRae, 1999; Solomon et al., 2010). The splinting of an acute tibial fracture with a posterior back-slab is also common practice; with the most commonly taught design involving covering the dorsum of the foot with bandaging (Charnley, 1950; Maher et al., 1994; McRae, 1989). We investigated the effect of the visual cues provided by exposing the dorsum of the foot and marking the dorsalis pedis pulse. We used a clinical simulation in which we compared the quality of the recorded clinical examination undertaken by 30 nurses. The nurses were randomly assigned to assess a patient with either a traditional back-slab or one in which the dorsal bandaging had been cut back and the dorsalis pedis pulse marked. We found that the quality of the recorded clinical examination was significantly better in the cut-back group. Previous studies have shown that the cut-back would not alter the effectiveness of the back-slab as a splint (Zagorski et al., 1993). We conclude that all tibial back-slabs should have the bandaging on the dorsum of the foot cut back and the location of the dorsalis pedis pulse marked. This simple adaptation will improve the subsequent clinical examinations undertaken and recorded without reducing the back-slab's effectiveness as a splint. PMID:27236718

  3. D-amphetamine improves attention performance in adolescent Wistar, but not in SHR rats, in a two-choice visual discrimination task.

    Science.gov (United States)

    Bizot, Jean-Charles; Cogrel, Nicolas; Massé, Fabienne; Chauvin, Virgile; Brault, Léa; David, Sabrina; Trovero, Fabrice

    2015-09-01

    The validity of spontaneous hypertensive rat (SHR) as a model of attention deficit hyperactivity disorder (ADHD) has been explored by comparing SHR with Wistar rats in a test of attention, the two-choice visual discrimination task (2-CVDT). Animals were 4-5 weeks old during the training phase of the experiment and 6-7 weeks old during the testing phase in which they were tested with D-amphetamine, a stimulant drug used for the treatment of ADHD. As compared to Wistar, SHR showed a slightly better attention performance, a slightly lower impulsivity level, and a lower general activity during the training phase, but these differences disappeared or lessened thereafter, during the testing phase. D-amphetamine (0.5, 1 mg/kg) improved attention performance in Wistar, but not in SHR, and did not modify impulsivity and activity in the two strains. In conclusion, the present study did not demonstrate that SHR represents a valid model of ADHD, since it did not show face validity regarding the behavioral symptoms of ADHD and predictive validity regarding the effect of a compound used for the treatment of ADHD. On the other hand, this study showed that the 2-CVDT may represent a suitable tool for evaluating in adolescent Wistar rats the effect on attention of compounds intended for the treatment of ADHD. PMID:26037943

  4. Visual imagery without visual perception?

    OpenAIRE

    Helder Bértolo

    2005-01-01

    The question regarding visual imagery and visual perception remain an open issue. Many studies have tried to understand if the two processes share the same mechanisms or if they are independent, using different neural substrates. Most research has been directed towards the need of activation of primary visual areas during imagery. Here we review some of the works providing evidence for both claims. It seems that studying visual imagery in blind subjects can be us...

  5. A general method to improve fluorophores for live-cell and single-molecule microscopy.

    Science.gov (United States)

    Grimm, Jonathan B; English, Brian P; Chen, Jiji; Slaughter, Joel P; Zhang, Zhengjian; Revyakin, Andrey; Patel, Ronak; Macklin, John J; Normanno, Davide; Singer, Robert H; Lionnet, Timothée; Lavis, Luke D

    2015-03-01

    Specific labeling of biomolecules with bright fluorophores is the keystone of fluorescence microscopy. Genetically encoded self-labeling tag proteins can be coupled to synthetic dyes inside living cells, resulting in brighter reporters than fluorescent proteins. Intracellular labeling using these techniques requires cell-permeable fluorescent ligands, however, limiting utility to a small number of classic fluorophores. Here we describe a simple structural modification that improves the brightness and photostability of dyes while preserving spectral properties and cell permeability. Inspired by molecular modeling, we replaced the N,N-dimethylamino substituents in tetramethylrhodamine with four-membered azetidine rings. This addition of two carbon atoms doubles the quantum efficiency and improves the photon yield of the dye in applications ranging from in vitro single-molecule measurements to super-resolution imaging. The novel substitution is generalizable, yielding a palette of chemical dyes with improved quantum efficiencies that spans the UV and visible range. PMID:25599551

  6. Visual Language in Visual Communication

    OpenAIRE

    Jia Wang

    2009-01-01

    In visual communication the design information is mainly communicated by visual language, the correct use of which is the standard of evaluation of a graphic design composition. Therefore it is necessary to understand and percept visual language properly. It will be helpful for viewers to percept the desired information from the designer as well as the significance within the work.

  7. Improving the Response of a Load Cell by Using Optimal Filtering

    Directory of Open Access Journals (Sweden)

    Wilmar Hernandez

    2006-07-01

    Full Text Available Load cells are transducers used to measure force or weight. Despite the fact thatthere is a wide variety of load cells, most of these transducers that are used in the weighingindustry are based on strain gauges. In this paper, an s-beam load cell based on strain gaugeswas suitably assembled to the mechanical structure of several seats of a bus underperformance tests and used to measure the resistance of their mechanical structure to tensionforces applied horizontally to the seats being tested. The load cell was buried in a broad-band noise background where the unwanted information and the relevant signal sometimesshare a very similar frequency spectrum and its performance was improved by using arecursive least-squares (RLS lattice algorithm. The experimental results are satisfactoryand a significant improvement in the signal-to-noise ratio at the system output of 27 dB wasachieved, which is a good performance factor for judging the quality of the system.

  8. Versatile microscale screening platform for improving recombinant protein productivity in Chinese hamster ovary cells

    DEFF Research Database (Denmark)

    Hansen, Henning Gram; Nilsson, Claes Nymand; Lund, Anne Mathilde;

    2015-01-01

    Chinese hamster ovary (CHO) cells are widely used as cell factories for the production of biopharmaceuticals. In contrast to the highly optimized production processes for monoclonal antibody (mAb)-based biopharmaceuticals, improving productivity of non-mAb therapeutic glycoproteins is more likely...... consists of four techniques compatible with 96-well microplates: lipid-based transient transfection, cell cultivation in microplates, cell counting and antibody-independent product titer determination based on split-GFP complementation. We were able to demonstrate growth profiles and volumetric...... to reduce production costs significantly. The aim of this study was to establish a versatile target gene screening platform for improving productivity for primarily non-mAb glycoproteins with complete interchangeability of model proteins and target genes using transient expression. The platform...

  9. Improved cell activity on biodegradable photopolymer scaffolds using titanate nanotube coatings

    International Nuclear Information System (INIS)

    The development of bioactive materials is in the premise of tissue engineering. For several years, surface functionalization of scaffolds has been one of the most promising approaches to stimulate cellular activity and finally improve implant success. Herein, we describe the development of a bioactive composite scaffold composed of a biodegradable photopolymer scaffold and titanate nanotubes (TNTs). The biodegradable photopolymer scaffolds were fabricated by applying mask-projection excimer laser photocuring at 308 nm. TNTs were synthesized and then spin-coated on the porous scaffolds. Upon culturing fibroblast cells on scaffolds, we found that nanotubes coating affects cell viability and proliferation demonstrating that TNT coatings enhance cell growth on the scaffolds by further improving their surface topography. - Highlights: • Biodegradable scaffolds were produced by mask-assisted UV laser photocuring. • Titanate nanotube deposition was carried out without binding compounds or additives. • Titanate nanotube coatings enhanced cell viability and proliferation

  10. Improved cell activity on biodegradable photopolymer scaffolds using titanate nanotube coatings

    Energy Technology Data Exchange (ETDEWEB)

    Beke, S., E-mail: szabolcs.beke@iit.it [Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova (Italy); Barenghi, R. [IEIIT, National Research Council (CNR), Via De Marini 6, 16149 Genova (Italy); Farkas, B.; Romano, I. [Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova (Italy); Kőrösi, L. [Department of Biotechnology, Nanophage Therapy Center, Enviroinvest Corporation, Kertváros u. 2, H-7632 Pécs (Hungary); Scaglione, S. [IEIIT, National Research Council (CNR), Via De Marini 6, 16149 Genova (Italy); Brandi, F. [Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova (Italy); Istituto Nazionale di Ottica, CNR, Via G. Moruzzi 1, 56124-Pisa (Italy)

    2014-11-01

    The development of bioactive materials is in the premise of tissue engineering. For several years, surface functionalization of scaffolds has been one of the most promising approaches to stimulate cellular activity and finally improve implant success. Herein, we describe the development of a bioactive composite scaffold composed of a biodegradable photopolymer scaffold and titanate nanotubes (TNTs). The biodegradable photopolymer scaffolds were fabricated by applying mask-projection excimer laser photocuring at 308 nm. TNTs were synthesized and then spin-coated on the porous scaffolds. Upon culturing fibroblast cells on scaffolds, we found that nanotubes coating affects cell viability and proliferation demonstrating that TNT coatings enhance cell growth on the scaffolds by further improving their surface topography. - Highlights: • Biodegradable scaffolds were produced by mask-assisted UV laser photocuring. • Titanate nanotube deposition was carried out without binding compounds or additives. • Titanate nanotube coatings enhanced cell viability and proliferation.

  11. System for adding sulfur to a fuel cell stack system for improved fuel cell stability

    Science.gov (United States)

    Mukerjee, Subhasish; Haltiner, Jr., Karl J; Weissman, Jeffrey G

    2013-08-13

    A system for adding sulfur to a reformate stream feeding a fuel cell stack, having a sulfur source for providing sulfur to the reformate stream and a metering device in fluid connection with the sulfur source and the reformate stream. The metering device injects sulfur from the sulfur source to the reformate stream at a predetermined rate, thereby providing a conditioned reformate stream to the fuel cell stack. The system provides a conditioned reformate stream having a predetermined sulfur concentration that gives an acceptable balance of minimal drop in initial power with the desired maximum stability of operation over prolonged periods for the fuel cell stack.

  12. Immunomodulation of Selective Naive T Cell Functions by p110δ Inactivation Improves the Outcome of Mismatched Cell Transplantation

    Directory of Open Access Journals (Sweden)

    Jean-Marc Doisne

    2015-02-01

    Full Text Available Allogeneic hematopoietic stem cell transplantation (HSCT can treat certain hematologic malignancies due to the graft versus leukemia (GvL effect but is complicated by graft versus host disease (GvHD. Expression of the p110δ catalytic subunit of the phosphoinositide 3-kinase pathway is restricted to leukocytes, where it regulates proliferation, migration, and cytokine production. Here, in a mouse model of fully mismatched hematopoietic cell transplantation (HCT, we show that genetic inactivation of p110δ in T cells leads to milder GvHD, whereas GvL is preserved. Inactivation of p110δ in human lymphocytes reduced T cell allorecognition. We demonstrate that both allostimulation and granzyme B expression were dependent on p110δ in naive T cells, which are the main mediators of GvHD, whereas memory T cells were unaffected. Strikingly, p110δ is not mandatory for either naive or memory T cells to mediate GvL. Therefore, immunomodulation of selective naive T cell functions by p110δ inactivation improves the outcome of allogeneic HSCT.

  13. Manipulating Light to Understand and Improve Solar Cells (494th Brookhaven Lecture)

    Energy Technology Data Exchange (ETDEWEB)

    Eisaman, Matthew [BNL, Sustainable Energy Technologies Department

    2014-04-16

    Energy consumption around the world is projected to approximately triple by the end of the century, according to the 2005 Report from the U.S. Department of Energy's Basic Energy Sciences Workshop on Solar Energy Utilization. Much will change in those next 86 years, but for all the power the world needs—for everything from manufacturing and transportation to air conditioning and charging cell phone batteries—improved solar cells will be crucial to meet this future energy demand with renewable energy sources. At Brookhaven Lab, scientists are probing solar cells and exploring variations within the cells—variations that are so small they are measured in billionths of a meter—in order to make increasingly efficient solar cells and ultimately help reduce the overall costs of deploying solar power plants. Dr. Eisaman will discuss DOE's Sunshot Initiative, which aims to reduce the cost of solar cell-generated electricity by 2020. He will also discuss how he and collaborators at Brookhaven Lab are probing different material compositions within solar cells, measuring how efficiently they collect electrical charge, helping to develop a new class of solar cells, and improving solar-cell manufacturing processes.

  14. An improved method for isolation of epithelial and stromal cells from the human endometrium.

    Science.gov (United States)

    Masuda, Ayako; Katoh, Noriko; Nakabayashi, Kazuhiko; Kato, Kiyoko; Sonoda, Kenzo; Kitade, Mari; Takeda, Satoru; Hata, Kenichiro; Tomikawa, Junko

    2016-04-22

    We aimed to improve the efficiency of isolating endometrial epithelial and stromal cells (EMECs and EMSCs) from the human endometrium. We revealed by immunohistochemical staining that the large tissue fragments remaining after collagenase treatment, which are usually discarded after the first filtration in the conventional protocol, consisted of glandular epithelial and stromal cells. Therefore, we established protease treatment and cell suspension conditions to dissociate single cells from the tissue fragments and isolated epithelial (EPCAM-positive) and stromal (CD13-positive) cells by fluorescence-activated cell sorting. Four independent experiments showed that, on average, 1.2 × 10(6) of EMECs and 2.8 × 10(6) EMSCs were isolated from one hysterectomy specimen. We confirmed that the isolated cells presented transcriptomic features highly similar to those of epithelial and stromal cells obtained by the conventional method. Our improved protocol facilitates future studies to better understand the molecular mechanisms underlying the dynamic changes of the endometrium during the menstrual cycle. PMID:26853786

  15. Improvement of a Si solar cell efficiency using pure and Fe3+ doped PVA films

    Science.gov (United States)

    Khalifa, N.; Kaouach, H.; Chtourou, R.

    2015-07-01

    One of the most important key driving the economic viability of solar cells is the high efficiency. This research focuses on the enhancement of commercial Si solar cell performance by deposing a pure and Fe3+ doped polyvinyl alcohol (PVA) layer on the top of the Si wafer of the considered cells. The use of such polymer to improve solar cells efficiency is actually a first. The authors will rely on the optical characteristics of the pure and doped PVA films including absorption and emission properties to justify the effect on Si cells. Commercial monocrystalline silicon solar cells of 15 cm2 (0.49 V/460 mA) are used in this work. Films of almost 80 μm of the ferric polymer are deposed on the cells. Films with the same thickness are characterized by UV-Vis spectroscopy and photoluminescent emission of the films is then investigated. The electrical properties of the cells with and without the organometallic layer are evaluated. It will be deduced an important improvement of all electrical parameters, including short-circuit current, open-circuit voltage, fill factor and spatially the conversion efficiency by almost 3%.

  16. A neural network model on self-organizing emergence of simple-cell receptive field with orientation selectivity in visual cortex

    Institute of Scientific and Technical Information of China (English)

    YANG; Qian(

    2001-01-01

    [1]Hubel, D. H.. Wiesel. T. N., Receptive fields of single neuron in the cat striate cortex, Journal of Physiology, 1959, 148:574-591.[2]Hubel. D. H.. Wiesel, T. N., Functional architecture macaque monkey visual cortexm, Proc. Roy. Soc. B, 1977, 198: 1-59.[3]Shou. T. D., Brain Mechanisms of Visual Information Processing (in Chinese), Shanghai: Shanghai Science-Technology and Education Press, 1997, 188-197.[4]Ferster, D., Chung, S., Wheat, H., Orientation selectivity of thalamic input to simple cells of cat visual cortex, Nature,1996, 380: 249-252.[5]Vidyasagar. T. R., Pei, X., Volgushev, M., Multiple mechanisms underlying the orientation selectivity of visual cortical neurons. TINS, 1996, 19: 272-277.[6]Artun, O. B., Shouval, H. Z., Cooper, L. N., The effect of dynamic synapses on spatiotemporal receptive fields in visual cortex, Proc. Natl. Acad. Sci. USA, 1998, 95:11999-12003.[7]Rolls, E. T.. Tovee, M. J., Sparseness of the neuronal representation of stimuli in the primate temporal visual cortex, J.Neurophysiology, 1995,73: 713-726.[8]Olshausen. B. A.. Field, D. J., Sparse coding with an overcomplete basis set: A strategy employed by V 1 ? Vision Research,1997.37: 3311-3325.[9]Bell. A. J., Sejnoswski, T. J., The "Independent components" of natural scenes are edge filters, Vision Research, 1997, 37:3327-3338.[10]Dan, Y., Atick, J. J., Reid, R. C., Efficient coding of natural scenes in the lateral geniculate nucleus: experimental test of a computational theory, Journal of Neuroscience, 1996, 16:3351-3362.[11]Field. D. J., Relations between the statistics of natural images and the response properties of cortical cells, Journal of the Optical Society of America A, 1987, 4: 2379-2394.[12]DeAngelis, G. C., Ohzawa, I., Freeman, R. D., Receptive filed dynamics in the central visual pathway, TINS, 1995,18:451-458.[13]Wang, Y. J., Qi, X. L., Chen, Y. Z., Simulations of receptive fields dynamics, TINS, 1996, 19: 385-386.

  17. BINDING TO AND RETENTION BY MUCOSAL CELLS OF THE TAMARINDUS INDICA SEED POLYSACCHARIDE: VISUAL EVALUATION BY MEANS OF INORGANIC AND ORGANIC MARKERS

    Directory of Open Access Journals (Sweden)

    P.C. Braga*, M. Dal Sasso, M. Culici

    2012-06-01

    Full Text Available The aim of this study was to investigate the possibility of using inorganic and organic markers to visualize the ability of the transparent polysaccharide (TSP polymer isolated from the endosperm of the seed kernel of Tamarindus indica, a tree that mainly grows in India and South-East Asia, to bind to human mucosal cells. A layer of human buccal cells was prepared on slides and overlaid by 0.2 ml of 0.6, 0.3, 0.15 and 0.075 % TSP solutions in phosphate buffer and then colloidal carbon black particles were deposited on the slides. The unbound colloidal carbon black particles were cleared by thoroughly washing the slides. The slides were then examined by means of Nomarski interference contrast microscopy in order to visualize the degree of surface retention of the black particles by the buccal cells. The same procedure was followed using Escherichia coli as organic markers. The clearly visible binding of black carbon particles to the cells treated with polymer revealed the presence of a thin layer of TSP covering the cells (untreated cells had no black carbon particles binding. The presence of the TSP has also been confirmed by a significant reduction in bacterial adhesiveness. Both markers made it possible to visualize the binding of the thin transparent layer of TSP and its retention, which was proportional to the degree of dilution. Using Escherichia coli it has been observed the possibility of counteracting the lock-and-key mechanism of micro-organism adhesion using the bioadhesive properties of this polymer to prevent possible contact between microorganism adhesins and complementary receptors.

  18. Interlaced semi-ellipsoid nanostructures for improving light trapping of ultrathin crystalline silicon solar cells

    Science.gov (United States)

    Gao, Ge; Li, Juntao; Wang, Xuehua

    2015-10-01

    Ultrathin crystalline silicon (c-Si) solar cells, which are of several micrometers thick, have attracted much attention in recent years, since it can greatly save raw materials than the traditional ones. To enhance the absorption, as well as to improve the cell efficiency, of the ultrathin c-Si, light trapping nanostructures are used to increase the effective absorption length to close to the 4n2 of the materials thickness, which is determined by the Lambertian limit. Here, we propose a novel interlaced semi-ellipsoid nanostructures (ISENs) to improve the performance of ultrathin c-Si solar cells. In this structure, the large and small periods in x and y direction can improve the light trapping capability at long and short wavelengths respectively. Meanwhile, the graded refractive index of the surface can act as the antireflection coating. By optimizing the ISENs, the short circuit current density of 30.15mA/cm2 was achieved by simulations for a 2 μm thick c-Si solar cell with rx = 500 nm, ry = 200 nm, rz= 550 nm and without antireflection coating and metal back reflector. The absorption is close to 87% of the Lambertian limit with equivalent thickness. We expect this structure can be fabricated by low cost nanosphere lithography technology and used to improve the efficiency of the ultrathin c-Si solar cells.

  19. Low dose of corticosterone treatment with exercise increases hippocampal cell proliferation, and improves cognition

    Institute of Scientific and Technical Information of China (English)

    Suk-Yu Yau; Jada Chia-Di Lee; Benson Wui-Man Lau; Tatia M.C. Lee; Yick-Pang Ching; Siu-Wa Tang; Kwok-Fai So

    2011-01-01

    Intermediate level of stress is beneficial for brain functions, whereas extreme low level or high level of stress is deleterious. We have previously shown that chronic exposure to high doses of corticosterone (CORT) suppressed hippocampal plasticity and physical exercise in terms of running counteracted the detrimental effects of CORT treatment. We aimed to study whether a mild stress, that mimicked by a treatment with low CORT dose, improved hippocampal plasticity in terms of hippocampal cell proliferation and dendritic remodeling, and to examine whether running with CORT treatment showed an additive effect on improving hippocampal plasticity. The rats were treated with 20 mg/kg CORT for 14 days with or without running, followed by Morris water maze test or forced swim test. The hippocampal proliferating cells was labeled by intraperitoneal injection of 5-bromo-2'-deoxyuridine. The dendritic morphology was analyzed using Golgi staining method. Treatment with 20 mg/kg CORT alone yielded a higher number of hippocampal cell proliferation and significantly increased dendritic branching compared to vehicle-treated non-runners, but had no behavioral effects. In contrast, CORT treatment with running showed an additive increase in hippocampal cell proliferation and dendritic remodeling that was associated with improved spatial learning and decreased depression-like behavior; however, there was no additive improvement in behavior compared to vehicle-treated runners. These findings suggest that mild stress does not always cause detrimental effect on the brain, and combining mild stress with running could promote hippocampal plasticity via inducing cell proliferation and dendritic remodeling.

  20. Does adipose tissue-derived stem cell therapy improve graft quality in freshly grafted ovaries?

    OpenAIRE

    Damous, Luciana L.; Nakamuta, Juliana S.; Saturi de Carvalho, Ana ET; Carvalho, Katia Candido; Soares-Jr, José Maria; Simões, Manuel Jesus; Krieger, José Eduardo; Baracat, Edmund Chada

    2015-01-01

    Background A major concern in ovarian transplants is substantial follicle loss during the initial period of hypoxia. Adipose tissue-derived stem cells (ASCs) have been employed to improve angiogenesis when injected into ischemic tissue. This study evaluated the safety and efficacy of adipose tissue-derived stem cells (ASCs) therapy in the freshly grafted ovaries 30 days after injection. Methods Rat ASCs (rASCs) obtained from transgenic rats expressing green fluorescent protein (GFP)-(5 × 104 ...