WorldWideScience

Sample records for cells improves visual

  1. Improving reading with visual processing training

    OpenAIRE

    Cvet, Mateja

    2013-01-01

    An apropriatly developed visual perception is an important element of success in reading. Visual dyslexia in children is connected with significant deficits in visual processing skills, and therefore has a strong impact on the reading ability as well as on the process of learning to read. Several studies have shown that regular training of visual skills can improve one’s reading ability and visual processing performance (Vidyasagar in Pammer, 2009) The purpose of this research project was...

  2. 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...

  3. 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

    an in 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...... 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...

  4. Magnocellular training improves visual word recognition

    Directory of Open Access Journals (Sweden)

    Tara eChouake

    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.

  5. 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

  6. Improved Electrophoresis Cell

    Science.gov (United States)

    Rhodes, P. H.; Snyder, R. S.

    1982-01-01

    Several proposed modifications are expected to improve performance of a continous-flow electrophoresis cell. Changes would allow better control of buffer flow and would increase resolution by suppressing thermal gradients. Improved electrophoresis device would have high resolution and be easy to operate. Improvements would allow better flow control and heat dissipation.

  7. Quantifying Improved Visual Performance Through Vision Training

    Science.gov (United States)

    1991-02-22

    either eye alone. Research suggests that spatial mechanisms may be differentially sensitive to inputs from the two eyes ( Arditi et al., 1981). If...importance of measuring contrast sensitivity in cases of visual disturbance. Br J Ophthalmol, 62, 198-209. Arditi , A.R., Anderson, P.A. and Movshon, J.A

  8. 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.

  9. Big data in medical informatics: improving education through visual analytics.

    Science.gov (United States)

    Vaitsis, Christos; Nilsson, Gunnar; Zary, Nabil

    2014-01-01

    A continuous effort to improve healthcare education today is currently driven from the need to create competent health professionals able to meet healthcare demands. Limited research reporting how educational data manipulation can help in healthcare education improvement. The emerging research field of visual analytics has the advantage to combine big data analysis and manipulation techniques, information and knowledge representation, and human cognitive strength to perceive and recognise visual patterns. The aim of this study was therefore to explore novel ways of representing curriculum and educational data using visual analytics. Three approaches of visualization and representation of educational data were presented. Five competencies at undergraduate medical program level addressed in courses were identified to inaccurately correspond to higher education board competencies. Different visual representations seem to have a potential in impacting on the ability to perceive entities and connections in the curriculum data.

  10. Visualizing T cell migration in-situ

    Directory of Open Access Journals (Sweden)

    Alexandre P Benechet

    2014-07-01

    Full Text Available Mounting a protective immune response is critically dependent on the orchestrated movement of cells within lymphoid tissues. The structure of secondary lymphoid organs regulates immune responses by promoting optimal cell-cell and cell-extracellular matrix interactions. Naïve T cells are initially activated by antigen presenting cells in secondary lymphoid organs. Following priming, effector T cells migrate to the site of infection to exert their functions. Majority of the effector cells die while a small population of antigen specific T cells persist as memory cells in distinct anatomical locations. The persistence and location of memory cells in lymphoid and non-lymphoid tissues is critical to protect the host from re-infection. The localization of memory T cells is carefully regulated by several factors including the highly organized secondary lymphoid structure, the cellular expression of chemokine receptors and compartmentalized secretion of their cognate ligands. This balance between the anatomy and the ordered expression of cell surface and soluble proteins regulates the subtle choreography of T cell migration. In recent years, our understanding of cellular dynamics of T cells has been advanced by the development of new imaging techniques allowing in-situ visualization of T cell responses. Here we review the past and more recent studies that have utilized sophisticated imaging technologies to investigate the migration dynamics of naive, effector and memory T cells.

  11. Visual Aids Improve Diagnostic Inferences and Metacognitive Judgment Calibration

    Directory of Open Access Journals (Sweden)

    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.

  12. 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…

  13. In vitro Spatial Compound Scanning for Improved Visualization of Atherosclerosis

    DEFF Research Database (Denmark)

    Jespersen, Søren Kragh; Wilhjelm, Jens E.; Sillesen, Henrik

    2000-01-01

    A new off-line multiangle ultrasound (US) compound scanner has been built with the purpose of investigating possible improvements in visualization of vascular structure. Images of two formalin-fixed human atherosclerotic plaques removed by carotid endarterectomy were recorded from seven insonific...

  14. 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.

  15. 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 biofeedback should be given in order to improve postural control (i.e., BF5 or BF10).

  16. Improved similarity trees and their application to visual data classification.

    Science.gov (United States)

    Paiva, Jose Gustavo S; Florian-Cruz, Laura; Pedrini, Helio; Telles, Guilherme P; Minghim, Rosane

    2011-12-01

    An alternative form to multidimensional projections for the visual analysis of data represented in multidimensional spaces is the deployment of similarity trees, such as Neighbor Joining trees. They organize data objects on the visual plane emphasizing their levels of similarity with high capability of detecting and separating groups and subgroups of objects. Besides this similarity-based hierarchical data organization, some of their advantages include the ability to decrease point clutter; high precision; and a consistent view of the data set during focusing, offering a very intuitive way to view the general structure of the data set as well as to drill down to groups and subgroups of interest. Disadvantages of similarity trees based on neighbor joining strategies include their computational cost and the presence of virtual nodes that utilize too much of the visual space. This paper presents a highly improved version of the similarity tree technique. The improvements in the technique are given by two procedures. The first is a strategy that replaces virtual nodes by promoting real leaf nodes to their place, saving large portions of space in the display and maintaining the expressiveness and precision of the technique. The second improvement is an implementation that significantly accelerates the algorithm, impacting its use for larger data sets. We also illustrate the applicability of the technique in visual data mining, showing its advantages to support visual classification of data sets, with special attention to the case of image classification. We demonstrate the capabilities of the tree for analysis and iterative manipulation and employ those capabilities to support evolving to a satisfactory data organization and classification.

  17. Improved curveball hitting through the enhancement of visual cues.

    OpenAIRE

    Osborne, K; Rudrud, E; Zezoney, F

    1990-01-01

    This study investigated the effectiveness of using visual cues to highlight the seams of baseballs to improve the hitting of curveballs. Five undergraduate varsity baseball team candidates served as subjects. Behavior change was assessed through an alternating treatments design involving unmarked balls and two treatment conditions that included baseballs with 1/4-in. and 1/8-in. orange stripes marking the seams of the baseballs. Results indicated that subjects hit a greater percentage of mark...

  18. 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.

  19. PromoSer: improvements to the algorithm, visualization and accessibility.

    Science.gov (United States)

    Halees, Anason S; Weng, Zhiping

    2004-07-01

    PromoSer is a web service that provides an easy and efficient approach to the batch retrieval of a large number of proximal promoters. Since its introduction last year, it has undergone continued development and expansion. At the core, there have been improvements in the filtering of the raw mRNA/EST sequences upon which all predictions are built, improvements in the alignments clustering and transcription start site prediction algorithms, and improvements in the backing database for increased performance. At the user interface level, improvements include enhanced functionality and user options, better integration with other resources on the web and a new visualization tool. PromoSer now also supports queries using a SOAP-based interface and XML-based responses. The service is publicly available at http://biowulf.bu.edu/zlab/PromoSer.

  20. Mirtazapine improves visual hallucinations in Parkinson's disease: a case report.

    Science.gov (United States)

    Tagai, Kenji; Nagata, Tomoyuki; Shinagawa, Shunichiro; Tsuno, Norifumi; Ozone, Motohiro; Nakayama, Kazuhiko

    2013-06-01

    Psychotic symptoms often occur as a complication in Parkinson's disease patients, and a set of criteria for Parkinson's disease with psychosis (PDPsy) has been established. Among these criteria, hallucinations are one of the specific symptoms, with visual hallucinations being the most common. While atypical antipsychotic agents are often used for the treatment of PDPsy, adverse effects, including extrapyramidal symptoms, often hinder its continuation or tolerance. There have been some reports and reviews indicating that antidepressants may be effective for PDPsy and other forms of dementia with psychosis. In this report, we present a patient with PDPsy who was treated with one of the new-generation antidepressants, mirtazapine. Mirtazapine improved the patient's refractory psychotic symptoms, especially her visual hallucinations, without worsening her motor symptoms.

  1. 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.

  2. Working memory training improves visual short-term memory capacity.

    Science.gov (United States)

    Schwarb, Hillary; Nail, Jayde; Schumacher, Eric H

    2016-01-01

    Since antiquity, philosophers, theologians, and scientists have been interested in human memory. However, researchers today are still working to understand the capabilities, boundaries, and architecture. While the storage capabilities of long-term memory are seemingly unlimited (Bahrick, J Exp Psychol 113:1-2, 1984), working memory, or the ability to maintain and manipulate information held in memory, seems to have stringent capacity limits (e.g., Cowan, Behav Brain Sci 24:87-185, 2001). Individual differences, however, do exist and these differences can often predict performance on a wide variety of tasks (cf. Engle What is working-memory capacity? 297-314, 2001). Recently, researchers have promoted the enticing possibility that simple behavioral training can expand the limits of working memory which indeed may also lead to improvements on other cognitive processes as well (cf. Morrison and Chein, Psychol Bull Rev 18:46-60 2011). However, initial investigations across a wide variety of cognitive functions have produced mixed results regarding the transferability of training-related improvements. Across two experiments, the present research focuses on the benefit of working memory training on visual short-term memory capacity-a cognitive process that has received little attention in the training literature. Data reveal training-related improvement of global measures of visual short-term memory as well as of measures of the independent sub-processes that contribute to capacity (Awh et al., Psychol Sci 18(7):622-628, 2007). These results suggest that the ability to inhibit irrelevant information within and between trials is enhanced via n-back training allowing for selective improvement on untrained tasks. Additionally, we highlight a potential limitation of the standard adaptive training procedure and propose a modified design to ensure variability in the training environment.

  3. Formal Art Observation Training Improves Medical Students’ Visual Diagnostic Skills

    Science.gov (United States)

    Naghshineh, Sheila; Hafler, Janet P.; Miller, Alexa R.; Blanco, Maria A.; Lipsitz, Stuart R.; Dubroff, Rachel P.; Khoshbin, Shahram

    2008-01-01

    Background Despite evidence of inadequate physical examination skills among medical students, teaching these skills has declined. One method of enhancing inspection skills is teaching “visual literacy,” the ability to reason physiology and pathophysiology from careful and unbiased observation. Objective To improve students’ visual acumen through structured observation of artworks, understanding of fine arts concepts and applying these skills to patient care. Design Prospective, partially randomized pre- vs. post-course evaluation using mixed-methods data analysis. Participants Twenty-four pre-clinical student participants were compared to 34 classmates at a similar stage of training. Intervention Training the Eye: Improving the Art of Physical Diagnosis consists of eight paired sessions of art observation exercises with didactics that integrate fine arts concepts with physical diagnosis topics and an elective life drawing session. Measurements The frequency of accurate observations on a 1-h visual skills examination was used to evaluate pre- vs. post-course descriptions of patient photographs and art imagery. Content analysis was used to identify thematic categories. All assessments were blinded to study group and pre- vs. post-course evaluation. Results Following the course, class participants increased their total mean number of observations compared to controls (5.41 ± 0.63 vs. 0.36 ± 0.53, p < 0.0001) and had increased sophistication in their descriptions of artistic and clinical imagery. A ‘dose-response’ was found for those who attended eight or more sessions, compared to participants who attended seven or fewer sessions (6.31 + 0.81 and 2.76 + 1.2, respectively, p = 0.03). Conclusions This interdisciplinary course improved participants’ capacity to make accurate observations of art and physical findings. Electronic supplementary material The online version of this article (doi:10.1007/s11606-008-0667-0) contains

  4. Atypical visual loss in giant cell arteritis

    DEFF Research Database (Denmark)

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

    1994-01-01

    in the 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......; in our experience this is unusual. In case No. 3 irreversible unilateral visual loss was typical for GCA, but the association with polyneuropathy unique. Neurological remission coincided with systemic corticosteroid therapy....

  5. 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

  6. Using Symmetrical Regions of Interest to Improve Visual SLAM

    NARCIS (Netherlands)

    Kootstra, Geert; Schomaker, Lambertus

    2009-01-01

    Simultaneous Localization and Mapping (SLAM) based on visual information is a challenging problem. One of the main problems with visual SLAM is to find good quality landmarks, that can be detected despite noise and small changes in viewpoint. Many approaches use SIFT interest points as visual landma

  7. [Visual hallucinations and giant cell arteritis: the Charles Bonnet syndrome].

    Science.gov (United States)

    Bloch, J; Morell-Dubois, S; Koch, E; Launay, D; Maillard-Lefebvre, H; Buchdahl, A-L; Hachulla, E; Rouland, J-F; Hatron, P-Y; Lambert, M

    2011-12-01

    In patients with visual hallucinations, diagnostic strategy is unclearly codified. In patients known to have giant cell arteritis, the main diagnostic assumption is disease relapse. Indeed, this should lead to rapid corticosteroid therapy. However, the Charles Bonnet syndrome, that is a poorly known etiology of visual hallucinations usually observed in elderly people, should be part of the differential diagnosis. We report a 87-year-old woman, with a 2-year history of giant cell arteritis who was admitted with an acute onset of visual hallucinations and who met all the criteria for Charles Bonnet syndrome.

  8. ROZA-XL, an improved FRET based biosensor with an increased dynamic range for visualizing zeta associated protein 70 kD (ZAP-70) tyrosine kinase activity in live T cells.

    Science.gov (United States)

    Cadra, Sophie; Gucciardi, Alexia; Valignat, Marie-Pierre; Theodoly, Olivier; Vacaflores, Aldo; Houtman, Jon C D; Lellouch, Annemarie C

    2015-04-10

    Genetically encoded FRET based biosensors allow one to visualize the spatial and temporal evolution of specific enzyme activities in live cells. We have previously reported the creation of a FRET based biosensor specific for Zeta-Associated Protein -70 kD (ZAP-70) (Randriamampita et al., 2008), a Syk family protein tyrosine kinase. ZAP-70 is essential for early T cell receptor (TCR) signaling events, T lymphocyte development and has also been implicated in integrin mediated T lymphocyte migration. In order to facilitate the study of ZAP-70 kinase activity during dynamic phenomena such as immunological synapse formation or cell migration, we have designed and prepared a second generation of ZAP-70 specific biosensors. Here we describe a novel biosensor named ROZA-XL, that displays a 3-4 times greater dynamic range than its predecessor and possesses a robust baseline FRET value when expressed in the Jurkat human T cell line. We demonstrate that the robust behavior of this biosensor allows for rapid analysis of TCR mediated of ZAP-70 kinase activity at a single cell level, as shown in a simple end point assay in which ROZA-XL expressing cells are allowed to interact with stimulatory anti-CD3epsilon coated coverslips.

  9. Visualization

    OpenAIRE

    Balon, Andreja

    1990-01-01

    The present thesis entails the field of visualization which is divided into visualization along traditional lines and visualization in computer science. As the psychological aspect of image is of vital importance for visualization, it is shortly described in the beginning. Visualization in computer science is divided into three main fields: scientific visualization, program visualization and visual programming. An explanation and examples of approach to applications are given for each field....

  10. Coupling Advanced Modeling and Visualization to Improve High-Impact Tropical Weather Prediction

    Science.gov (United States)

    Shen, Bo-Wen; Tao, Wei-Kuo; Green, Bryan

    2009-01-01

    To meet the goals of extreme weather event warning, this approach couples a modeling and visualization system that integrates existing NASA technologies and improves the modeling system's parallel scalability to take advantage of petascale supercomputers. It also streamlines the data flow for fast processing and 3D visualizations, and develops visualization modules to fuse NASA satellite data.

  11. Visual syntax does matter: improving the cognitive effectiveness of the i* visual notation

    NARCIS (Netherlands)

    Moody, Daniel L.; Heymans, Patrick; Matulevicius, Raimundas

    2010-01-01

    Goal-oriented modelling is one of the most important research developments in the requirements engineering (RE) field. This paper conducts a systematic analysis of the visual syntax of i*, one of the leading goal-oriented languages. Like most RE notations, i* is highly visual. Yet surprisingly, ther

  12. Improved Discrimination of Visual Stimuli Following Repetitive Transcranial Magnetic Stimulation

    OpenAIRE

    Waterston, Michael L.; Pack, Christopher C.

    2010-01-01

    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 t...

  13. 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

  14. 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

  15. 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

  16. Navigating through virtual environments: visual realism improves spatial cognition.

    Science.gov (United States)

    Meijer, Frank; Geudeke, Branko L; van den Broek, Egon L

    2009-10-01

    Recent advances in computer technology have significantly facilitated the use of virtual environments (VE) for small and medium enterprises (SME). However, achieving visual realism in such VE requires high investments in terms of time and effort, while its usefulness has not yet become apparent from research. Other qualities of VE, such as the use of large displays, proved its effectiveness in enhancing the individual user's spatial cognition. The current study assessed whether the same benefits apply for visual realism in VE. Thirty-two participants were divided into two groups, who explored either a photorealistic or a nonrealistic supermarket presented on a large screen. The participants were asked to navigate through the supermarket on a predetermined route. Subsequently, spatial learning was tested in four pen-and-paper tests that assessed how accurately they had memorized the route and the environment's spatial layout. The study revealed increased spatial learning from the photorealistic compared to the nonrealistic supermarket. Specifically, participants performed better on tests that involved egocentric spatial knowledge. The results suggest visual realism is useful because it increases the user's spatial knowledge in the VE. Therefore, the current study provides clear evidence that it is worthwhile for SME to invest in achieving visual realism in VE.

  17. Current techniques for visualizing RNA in cells

    Science.gov (United States)

    Mannack, Lilith V.J.C.; Eising, Sebastian; Rentmeister, Andrea

    2016-01-01

    Labeling RNA is of utmost interest, particularly in living cells, and thus RNA imaging is an emerging field. There are numerous methods relying on different concepts ranging from hybridization-based probes, over RNA-binding proteins to chemo-enzymatic modification of RNA. These methods have different benefits and limitations. This review aims to outline the current state-of-the-art techniques and point out their benefits and limitations. PMID:27158473

  18. Cognitive and psychological science insights to improve climate change data visualization

    Science.gov (United States)

    Harold, Jordan; Lorenzoni, Irene; Shipley, Thomas F.; Coventry, Kenny R.

    2016-12-01

    Visualization of climate data plays an integral role in the communication of climate change findings to both expert and non-expert audiences. The cognitive and psychological sciences can provide valuable insights into how to improve visualization of climate data based on knowledge of how the human brain processes visual and linguistic information. We review four key research areas to demonstrate their potential to make data more accessible to diverse audiences: directing visual attention, visual complexity, making inferences from visuals, and the mapping between visuals and language. We present evidence-informed guidelines to help climate scientists increase the accessibility of graphics to non-experts, and illustrate how the guidelines can work in practice in the context of Intergovernmental Panel on Climate Change graphics.

  19. Cell-fusion method to visualize interphase nuclear pore formation.

    Science.gov (United States)

    Maeshima, Kazuhiro; Funakoshi, Tomoko; Imamoto, Naoko

    2014-01-01

    In eukaryotic cells, the nucleus is a complex and sophisticated organelle that organizes genomic DNA to support essential cellular functions. The nuclear surface contains many nuclear pore complexes (NPCs), channels for macromolecular transport between the cytoplasm and nucleus. It is well known that the number of NPCs almost doubles during interphase in cycling cells. However, the mechanism of NPC formation is poorly understood, presumably because a practical system for analysis does not exist. The most difficult obstacle in the visualization of interphase NPC formation is that NPCs already exist after nuclear envelope formation, and these existing NPCs interfere with the observation of nascent NPCs. To overcome this obstacle, we developed a novel system using the cell-fusion technique (heterokaryon method), previously also used to analyze the shuttling of macromolecules between the cytoplasm and the nucleus, to visualize the newly synthesized interphase NPCs. In addition, we used a photobleaching approach that validated the cell-fusion method. We recently used these methods to demonstrate the role of cyclin-dependent protein kinases and of Pom121 in interphase NPC formation in cycling human cells. Here, we describe the details of the cell-fusion approach and compare the system with other NPC formation visualization methods.

  20. Visual outcome, ocular findings, and visual processing skills after allogeneic stem cell transplantation in children

    OpenAIRE

    Törnquist, Alba Lucia

    2010-01-01

    Background: Stem cell transplantation (SCT) offers a chance of cure in children with leukaemia and other life-threatening haematological, immunological, and metabolic diseases that do not respond to conventional treatment. Pre and post SCT, these children receive irradiation, and/or chemotherapy and immunosuppressive agents which like the primary disease may adversely affect the eye, the central nervous system as well as the posterior visual pathways and potentially threaten...

  1. 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.

  2. Improving Visual Survey Capabilities for Marine Mammal Studies

    Science.gov (United States)

    2015-09-30

    binoculars will be used to collect critical ground-truth visual observations from ship - and land-based platforms in proximity to autonomous ...breathing mammals, and they can be conducted from ships , aircraft, or land. For ship - and land-based surveys, powerful, pedestal-mounted, 25×150...classification, and reporting from autonomous platforms, a capability that has been developed with support from the ONR MMB program. The DURIP-funded big-eye

  3. 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…

  4. 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…

  5. 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.

  6. Improved visualization of delayed perfusion in lung MRI

    Energy Technology Data Exchange (ETDEWEB)

    Risse, Frank [Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg (Germany); Eichinger, Monika [Department of Radiology, German Cancer Research Center, Heidelberg (Germany); Kauczor, Hans-Ulrich [Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg (Germany); Semmler, Wolfhard [Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg (Germany); Puderbach, Michael, E-mail: m.puderbach@dkfz.de [Department of Radiology, German Cancer Research Center, Heidelberg (Germany)

    2011-01-15

    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 S{sub n,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 {tau} to visualize regions with delayed bolus onset; and (3) ratio R = S{sub n,max}/{tau} 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.

  7. Fourier-based automatic alignment for improved Visual Cryptography schemes.

    Science.gov (United States)

    Machizaud, Jacques; Chavel, Pierre; Fournel, Thierry

    2011-11-01

    In Visual Cryptography, several images, called "shadow images", that separately contain no information, are overlapped to reveal a shared secret message. We develop a method to digitally register one printed shadow image acquired by a camera with a purely digital shadow image, stored in memory. Using Fourier techniques derived from Fourier Optics concepts, the idea is to enhance and exploit the quasi periodicity of the shadow images, composed by a random distribution of black and white patterns on a periodic sampling grid. The advantage is to speed up the security control or the access time to the message, in particular in the cases of a small pixel size or of large numbers of pixels. Furthermore, the interest of visual cryptography can be increased by embedding the initial message in two shadow images that do not have identical mathematical supports, making manual registration impractical. Experimental results demonstrate the successful operation of the method, including the possibility to directly project the result onto the printed shadow image.

  8. In vivo cell biology of cancer cells visualized with fluorescent proteins.

    Science.gov (United States)

    Hoffman, Robert M

    2005-01-01

    This chapter describes a new cell biology where the behavior of individual cells can be visualized in the living animal. Previously it has been demonstrated that fluorescent proteins can be used for whole-body imaging of metastatic tumor growth, bacterial infection, and gene expression. An example of the new cell biology is dual-color fluorescence imaging using red fluorescent protein (RFP)-expressing tumors transplanted in green fluorescent protein (GFP)-expressing transgenic mice. These models show with great clarity the details of tumor-stroma interactions and especially tumor-induced angiogenesis, tumor-infiltrating lymphocytes, stromal fibroblasts, and macrophages. Another example is the color coding of cells with RFP or GFP such that both cell types can be simultaneously visualized in vivo. Stem cells can also be visualized and tracked in vivo. Mice in which the regulatory elements of the stem cell marker nestin drive GFP expression enable nascent vasculature to be visualized interacting with transplanted RFP-expressing cancer cells. Nestin-driven GFP expression can also be used to visualize hair follicle stem cells. Dual-color cells expressing GFP in the nucleus and RFP in the cytoplasm enable real-time visualization of nuclear-cytoplasm dynamics including cell cycle events and apoptosis. Highly elongated cancer cells in capillaries in living mice were observed within skin flaps. The migration velocities of the cancer cells in the capillaries were measured by capturing images of the dual-color fluorescent cells over time. The cells in the capillaries elongated to fit the width of these vessels. The use of the dual-color cancer cells differentially labeled in the cytoplasm and nucleus and associated fluorescent imaging provide a powerful tool to understand the mechanism of cancer cell migration and deformation in small vessels.

  9. Improving driving performance of persons with visual field defects : Results of a pilot study

    NARCIS (Netherlands)

    Coeckelbergh, TRM; Kooijman, AC; Brouwer, WH; Cornelissen, FW; Gale, AG

    1999-01-01

    Four subjects with peripheral field defects, one subject with central field defects and one subject with normal visual fields were trained to improve driving performance by means of improving their scanning behaviour. After training, overall driving performance did not improve. Viewing behaviour, ho

  10. IN-CELL visual examinations of K east fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Pitner, A.L.; Pyecha, T.D., Fluor Daniel Hanford

    1997-03-06

    Nine outer fuel elements were recovered from the K East Basin and transferred to a hot cell for examination. Extensive testing planned for these elements will support the process design for the Integrated Process Strategy (IPS), with emphasis on drying and conditioning behavior. Visual examinations of the fuel elements confirmed that they are appropriate to meet testing objectives to provide design guidance for IPS processing parameters.

  11. Nerve growth factor eye drops improve visual acuity and electrofunctional activity in age-related macular degeneration: a case report

    Directory of Open Access Journals (Sweden)

    Alessandro Lambiase

    2009-12-01

    Full Text Available Age-related macular degeneration (ARMD is a severe disease affecting visual function in the elderly. Currently available surgical and medical options do not guarantee a significant impact on the outcome of the disease. We describe the effects of nerve growth factor eye drop treatment in a 94 years old female with ARMD, whose visual acuity was progressively worsening in spite of previous surgical and medical treatments. NGF eye drops improved visual acuity and electrofunctional parameters as early as 3 months after initiation of treatment. These results are in line with previous reports on a neuroprotective effect of NGF on retinal cells and on NGF eye drops bioavailability in the retina and optic nerve. No side effects were observed after five years of follow-up, suggesting that topical NGF treatment may be a safe and effective therapy for ARMD.

  12. 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.

  13. Improving texture optimization with application to visualizing meat products

    DEFF Research Database (Denmark)

    Clemmensen, Line Katrine Harder; Laursen, Lasse Farnung

    2011-01-01

    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...

  14. Purification, Visualization, and Molecular Signature of Neural Stem Cells

    Science.gov (United States)

    Yu, Yuan Hong; Narayanan, Gunaseelan; Sankaran, Shvetha; Ramasamy, Srinivas; Chan, Shi Yu; Lin, Shuping; Chen, Jinmiao; Yang, Henry; Srivats, Hariharan

    2016-01-01

    Neural stem cells (NSCs) are isolated from primary brain tissue and propagated as a heterogeneous mix of cells, including neural progenitors. To date, NSCs have not been purified in vitro to allow study of their biology and utility in regenerative medicine. In this study, we identify C1qR1as a novel marker for NSCs and show that it can be used along with Lewis-X (LeX) to yield a highly purified population of NSCs. Using time-lapse microscopy, we are able to follow NSCs forming neurospheres, allowing their visualization. Finally, using single-cell polymerase chain reaction (PCR), we determine the molecular signature of NSCs. The single-cell PCR data suggest that along with the Notch and Shh pathways, the Hippo pathway plays an important role in NSC activity. PMID:26464067

  15. A Small Motor Cortex Lesion Abolished Ocular Dominance Plasticity in the Adult Mouse Primary Visual Cortex and Impaired Experience-Dependent Visual Improvements

    Science.gov (United States)

    Pielecka-Fortuna, Justyna; Kalogeraki, Evgenia; Greifzu, Franziska; Löwel, Siegrid

    2015-01-01

    It was previously shown that a small lesion in the primary somatosensory cortex (S1) prevented both cortical plasticity and sensory learning in the adult mouse visual system: While 3-month-old control mice continued to show ocular dominance (OD) plasticity in their primary visual cortex (V1) after monocular deprivation (MD), age-matched mice with a small photothrombotically induced (PT) stroke lesion in S1, positioned at least 1 mm anterior to the anterior border of V1, no longer expressed OD-plasticity. In addition, in the S1-lesioned mice, neither the experience-dependent increase of the spatial frequency threshold (“visual acuity”) nor of the contrast threshold (“contrast sensitivity”) of the optomotor reflex through the open eye was present. To assess whether these plasticity impairments can also occur if a lesion is placed more distant from V1, we tested the effect of a PT-lesion in the secondary motor cortex (M2). We observed that mice with a small M2-lesion restricted to the superficial cortical layers no longer expressed an OD-shift towards the open eye after 7 days of MD in V1 of the lesioned hemisphere. Consistent with previous findings about the consequences of an S1-lesion, OD-plasticity in V1 of the nonlesioned hemisphere of the M2-lesioned mice was still present. In addition, the experience-dependent improvements of both visual acuity and contrast sensitivity of the open eye were severely reduced. In contrast, sham-lesioned mice displayed both an OD-shift and improvements of visual capabilities of their open eye. To summarize, our data indicate that even a very small lesion restricted to the superficial cortical layers and more than 3mm anterior to the anterior border of V1 compromised V1-plasticity and impaired learning-induced visual improvements in adult mice. Thus both plasticity phenomena cannot only depend on modality-specific and local nerve cell networks but are clearly influenced by long-range interactions even from distant brain

  16. A Small Motor Cortex Lesion Abolished Ocular Dominance Plasticity in the Adult Mouse Primary Visual Cortex and Impaired Experience-Dependent Visual Improvements.

    Science.gov (United States)

    Pielecka-Fortuna, Justyna; Kalogeraki, Evgenia; Greifzu, Franziska; Löwel, Siegrid

    2015-01-01

    It was previously shown that a small lesion in the primary somatosensory cortex (S1) prevented both cortical plasticity and sensory learning in the adult mouse visual system: While 3-month-old control mice continued to show ocular dominance (OD) plasticity in their primary visual cortex (V1) after monocular deprivation (MD), age-matched mice with a small photothrombotically induced (PT) stroke lesion in S1, positioned at least 1 mm anterior to the anterior border of V1, no longer expressed OD-plasticity. In addition, in the S1-lesioned mice, neither the experience-dependent increase of the spatial frequency threshold ("visual acuity") nor of the contrast threshold ("contrast sensitivity") of the optomotor reflex through the open eye was present. To assess whether these plasticity impairments can also occur if a lesion is placed more distant from V1, we tested the effect of a PT-lesion in the secondary motor cortex (M2). We observed that mice with a small M2-lesion restricted to the superficial cortical layers no longer expressed an OD-shift towards the open eye after 7 days of MD in V1 of the lesioned hemisphere. Consistent with previous findings about the consequences of an S1-lesion, OD-plasticity in V1 of the nonlesioned hemisphere of the M2-lesioned mice was still present. In addition, the experience-dependent improvements of both visual acuity and contrast sensitivity of the open eye were severely reduced. In contrast, sham-lesioned mice displayed both an OD-shift and improvements of visual capabilities of their open eye. To summarize, our data indicate that even a very small lesion restricted to the superficial cortical layers and more than 3mm anterior to the anterior border of V1 compromised V1-plasticity and impaired learning-induced visual improvements in adult mice. Thus both plasticity phenomena cannot only depend on modality-specific and local nerve cell networks but are clearly influenced by long-range interactions even from distant brain regions.

  17. Rapid improvement in visual loss with cabergoline treatment in a giant prolactinoma case: 5 years survey.

    Science.gov (United States)

    Tasan, Ertugrul; Hanimoglu, Hakan; Turgut, Seda; Ilhan, Mahmut Muzaffer; Evran, Sevket; Kaynar, Mehmet Yasar

    2015-01-01

    Giant prolactinoma is a rare subset of macroadenomas. Limited studies demonstrated which therapy could be successfully used in the first-line therapy of giant prolactinoma. We presented a case with a 54 × 40 × 40 mm pituitary adenoma and optic chiasmatic compression with left sphenoid sinus invasion. The tumor caused a loss of visual field of the right side. Cabergoline treatment was started with dose of 1.5 mg/week. Fifteen days later, the clinical visual acuity examination showed a significant improvement in the patient with visual field defect. After the five years follow-up magnetic resonance imagining showed reduction of the adenoma size (17 × 12 mm) was significant. Our findings suggest that, cabergoline can be used as a first-line therapy in giant prolactinomas because tumoral shrinkage without a surgical procedure and rapid improvement in visual field defect is achieved with this medical treatment.

  18. Assistance to bone milling: a tool mounted visual display improves the efficiency of robotic guidance.

    Science.gov (United States)

    Francoise, Vincent; Sahbani, Anis; Roby-Brami, Agnes; Morel, Guillaume

    2013-01-01

    In this paper, a new kind of assistance for bone milling is disclosed. It combines a robotic comanipulator applying forces to guide the milling tool tip with a visual display mounted on the hand-held tool. This visual display is a LED bargraph providing to the user a geometric information that is mostly redundant with the forces exerted by the robot, thus constituting a multi-modal feedback. Although very basic and rather inexpensive, the additional visual display is experimentally shown to significantly improve the precision of the gesture.

  19. Weakly circadian cells improve resynchrony.

    Directory of Open Access Journals (Sweden)

    Alexis B Webb

    Full Text Available The mammalian suprachiasmatic nuclei (SCN contain thousands of neurons capable of generating near 24-h rhythms. When isolated from their network, SCN neurons exhibit a range of oscillatory phenotypes: sustained or damping oscillations, or arrhythmic patterns. The implications of this variability are unknown. Experimentally, we found that cells within SCN explants recover from pharmacologically-induced desynchrony by re-establishing rhythmicity and synchrony in waves, independent of their intrinsic circadian period We therefore hypothesized that a cell's location within the network may also critically determine its resynchronization. To test this, we employed a deterministic, mechanistic model of circadian oscillators where we could independently control cell-intrinsic and network-connectivity parameters. We found that small changes in key parameters produced the full range of oscillatory phenotypes seen in biological cells, including similar distributions of period, amplitude and ability to cycle. The model also predicted that weaker oscillators could adjust their phase more readily than stronger oscillators. Using these model cells we explored potential biological consequences of their number and placement within the network. We found that the population synchronized to a higher degree when weak oscillators were at highly connected nodes within the network. A mathematically independent phase-amplitude model reproduced these findings. Thus, small differences in cell-intrinsic parameters contribute to large changes in the oscillatory ability of a cell, but the location of weak oscillators within the network also critically shapes the degree of synchronization for the population.

  20. Direct Visualization of DNA Replication Dynamics in Zebrafish Cells.

    Science.gov (United States)

    Kuriya, Kenji; Higashiyama, Eriko; Avşar-Ban, Eriko; Tamaru, Yutaka; Ogata, Shin; Takebayashi, Shin-ichiro; Ogata, Masato; Okumura, Katsuzumi

    2015-12-01

    Spatiotemporal regulation of DNA replication in the S-phase nucleus has been extensively studied in mammalian cells because it is tightly coupled with the regulation of other nuclear processes such as transcription. However, little is known about the replication dynamics in nonmammalian cells. Here, we analyzed the DNA replication processes of zebrafish (Danio rerio) cells through the direct visualization of replicating DNA in the nucleus and on DNA fiber molecules isolated from the nucleus. We found that zebrafish chromosomal DNA at the nuclear interior was replicated first, followed by replication of DNA at the nuclear periphery, which is reminiscent of the spatiotemporal regulation of mammalian DNA replication. However, the relative duration of interior DNA replication in zebrafish cells was longer compared to mammalian cells, possibly reflecting zebrafish-specific genomic organization. The rate of replication fork progression and ori-to-ori distance measured by the DNA combing technique were ∼ 1.4 kb/min and 100 kb, respectively, which are comparable to those in mammalian cells. To our knowledge, this is a first report that measures replication dynamics in zebrafish cells.

  1. Improved premises for cell factory development

    DEFF Research Database (Denmark)

    Søgaard, Karina Marie

    is at the core of biotechnology and numerous molecular tools and bacterial strains have been developed over the past four decades for this purpose. Understanding of the genetic code and our ability to manipulate genetic material, paves the way for the microbial cell factory development that enables production...... of protein in a sustainable, costefficient manner. In this thesis I report the joined efforts of my colleagues and myself, to improve the premises for cell factory development by optimizing the cloning strategies, improving the awareness of unforeseen side-effects in complex bacterial expression systems...... have improved the premises for cell factory development in the future....

  2. Analysis of visual quality improvements provided by known tools for HDR content

    Science.gov (United States)

    Kim, Jaehwan; Alshina, Elena; Lee, JongSeok; Park, Youngo; Choi, Kwang Pyo

    2016-09-01

    In this paper, the visual quality of different solutions for high dynamic range (HDR) compression using MPEG test contents is analyzed. We also simulate the method for an efficient HDR compression which is based on statistical property of the signal. The method is compliant with HEVC specification and also easily compatible with other alternative methods which might require HEVC specification changes. It was subjectively tested on commercial TVs and compared with alternative solutions for HDR coding. Subjective visual quality tests were performed using SUHD TVs model which is SAMSUNG JS9500 with maximum luminance up to 1000nit in test. The solution that is based on statistical property shows not only improvement of objective performance but improvement of visual quality compared to other HDR solutions, while it is compatible with HEVC specification.

  3. Dynamic culture improves cell reprogramming efficiency.

    Science.gov (United States)

    Sia, Junren; Sun, Raymond; Chu, Julia; Li, Song

    2016-06-01

    Cell reprogramming to pluripotency is an inefficient process and various approaches have been devised to improve the yield of induced pluripotent stem cells. However, the effect of biophysical factors on cell reprogramming is not well understood. Here we showed that, for the first time, dynamic culture with orbital shaking significantly improved the reprogramming efficiency in adherent cells. Manipulating the viscosity of the culture medium suggested that the improved efficiency is mainly attributed to convective mixing rather than hydrodynamic shear stress. Temporal studies demonstrated that the enhancement of reprogramming efficiency required the dynamic culture in the middle but not early phase. In the early phase, fibroblasts had a high proliferation rate, but as the culture became over-confluent in the middle phase, expression of p57 was upregulated to inhibit cell proliferation and consequently, cell reprogramming. Subjecting the over confluent culture to orbital shaking prevented the upregulation of p57, thus improving reprogramming efficiency. Seeding cells at low densities to avoid over-confluency resulted in a lower efficiency, and optimal reprogramming efficiency was attained at a high seeding density with dynamic culture. Our findings provide insight into the underlying mechanisms of how dynamic culture condition regulate cell reprogramming, and will have broad impact on cell engineering for regenerative medicine and disease modeling.

  4. Improving the Visual Magnitudes of the Planets in The Astronomical Almanac. I. Mercury and Venus

    Science.gov (United States)

    2005-01-01

    2005 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Improving the Visual Magnitudes of the Planets in The Astronomical Almanac...1. Mercury and Venus 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK

  5. The Role of Visual Learning in Improving Students' High-Order Thinking Skills

    Science.gov (United States)

    Raiyn, Jamal

    2016-01-01

    Various concepts have been introduced to improve students' analytical thinking skills based on problem based learning (PBL). This paper introduces a new concept to increase student's analytical thinking skills based on a visual learning strategy. Such a strategy has three fundamental components: a teacher, a student, and a learning process. The…

  6. Improved Gas Seal for Electrolytic Cells

    Science.gov (United States)

    Richter, R.

    1984-01-01

    Breakage by differential thermal expansion reduced. Cells for hot electrolysis of gases improved by design that reduces vulnerability of gas seals to breakage at operating temperature of about 1000 degrees C.

  7. Helium Ion Microscopy Visualizes Lipid Nanodomains in Mammalian Cells.

    Science.gov (United States)

    Schürmann, Matthias; Frese, Natalie; Beyer, André; Heimann, Peter; Widera, Darius; Mönkemöller, Viola; Huser, Thomas; Kaltschmidt, Barbara; Kaltschmidt, Christian; Gölzhäuser, Armin

    2015-11-18

    Cell membranes are composed of 2D bilayers of amphipathic lipids, which allow a lateral movement of the respective membrane components. These components are arranged in an inhomogeneous manner as transient micro- and nanodomains, which are believed to be crucially involved in the regulation of signal transduction pathways in mammalian cells. Because of their small size (diameter 10-200 nm), membrane nanodomains cannot be directly imaged using conventional light microscopy. Here, direct visualization of cell membrane nanodomains by helium ion microscopy (HIM) is presented. It is shown that HIM is capable to image biological specimens without any conductive coating and that HIM images clearly allow the identification of nanodomains in the ultrastructure of membranes with 1.5 nm resolution. The shape of these nanodomains is preserved by fixation of the surrounding unsaturated fatty acids while saturated fatty acids inside the nanodomains are selectively removed. Atomic force microscopy, fluorescence microscopy, 3D structured illumination microscopy, and direct stochastic optical reconstruction microscopy provide additional evidence that the structures in the HIM images of cell membranes originate from membrane nanodomains. The nanodomains observed by HIM have an average diameter of 20 nm and are densely arranged with a minimal nearest neighbor distance of ≈ 15 nm.

  8. Noise improves visual motion discrimination via a stochastic resonance-like phenomenon

    Directory of Open Access Journals (Sweden)

    Mario Treviño

    2016-11-01

    Full Text Available The stochastic resonance (SR is a phenomenon in which adding a moderate amount of noise can improve the signal-to-noise ratio (SNR and performance of nonlinear systems. SR occurs in all sensory modalities including the visual system in which noise can enhance contrast detection sensitivity and the perception of ambiguous figures embedded in static scenes. Here, we explored how adding background white pixel-noise to a random dot motion (RDM stimulus produced changes in visual motion discrimination in healthy human adults. We found that, although the average reaction times remained constant, an intermediate level of noise improved the subjects' ability to discriminate motion direction in the RDM task. The psychophysical responses followed an inverted U-like function of the input noise, whereas the incorrect responses with short reaction times did not exhibit such modulation by external noise. Moreover, by applying stimulus and noisy signals to different eyes, we found that the SR phenomenon occurred presumably in the primary visual cortex, where these two signals first converge. Our results suggest that a stochastic resonance-like phenomenon mediates the improvement of visual motion perception in the RDM task.

  9. Noise Improves Visual Motion Discrimination via a Stochastic Resonance-Like Phenomenon

    Science.gov (United States)

    Treviño, Mario; De la Torre-Valdovinos, Braniff; Manjarrez, Elias

    2016-01-01

    The stochastic resonance (SR) is a phenomenon in which adding a moderate amount of noise can improve the signal-to-noise ratio and performance of non-linear systems. SR occurs in all sensory modalities including the visual system in which noise can enhance contrast detection sensitivity and the perception of ambiguous figures embedded in static scenes. Here, we explored how adding background white pixel-noise to a random dot motion (RDM) stimulus produced changes in visual motion discrimination in healthy human adults. We found that, although the average reaction times (RTs) remained constant, an intermediate level of noise improved the subjects’ ability to discriminate motion direction in the RDM task. The psychophysical responses followed an inverted U-like function of the input noise, whereas the incorrect responses with short RTs did not exhibit such modulation by external noise. Moreover, by applying stimulus and noisy signals to different eyes, we found that the SR phenomenon occurred presumably in the primary visual cortex, where these two signals first converge. Our results suggest that a SR-like phenomenon mediates the improvement of visual motion perception in the RDM task. PMID:27932960

  10. Music training improves verbal but not visual memory: cross-sectional and longitudinal explorations in children.

    Science.gov (United States)

    Ho, Yim-Chi; Cheung, Mei-Chun; Chan, Agnes S

    2003-07-01

    The hypothesis that music training can improve verbal memory was tested in children. The results showed that children with music training demonstrated better verbal but not visual memory than did their counterparts without such training. When these children were followed up after a year, those who had begun or continued music training demonstrated significant verbal memory improvement. Students who discontinued the training did not show any improvement. Contrary to the differences in verbal memory between the groups, their changes in visual memory were not significantly different. Consistent with previous findings for adults (A. S. Chan, Y. Ho, & M. Cheung, 1998), the results suggest that music training systematically affects memory processing in accordance with possible neuroanatomical modifications in the left temporal lobe.

  11. 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.

  12. Visual evoked potentials (VEP and visual acuity improvement after cytidine 52 -diphosphocholine (CDP-Choline therapy in amblyopic patient

    Directory of Open Access Journals (Sweden)

    Regina Halfeld Furtado de Mendonça

    2012-10-01

    Full Text Available Citicoline may be used in many neurological disorders. Combined treatment of citicoline with patching in amblyopia has previously been researched. The purpose of this paper is to illustrate the effect of citicoline in non-patching amblyopic patient. A 11-year-old amblyopic boy underwent complete ophthalmological examinations, including VEP with flash and pattern stimulus. Two averages of 100 sweep were performed for flash stimulus. Pattern reversal stimulus obtained with high contrast was performed with 60', 30' and 15' checks stimuli. The VEP was repeated 90 days later after a therapy with citicoline and vitamin and the results compared with the responses of the previous recording session. The visual acuity (VA was 0,7 in the RE and 1,0 in the LE. The VEP pattern amplitude was normal in both eyes. Delayed in latency was detected for all spatial frequency stimulus (SFS in the RE. Delay in latency was detected only for high SFS in the LE. After the treatment, the VA was 1,0 in both eyes. The latency was normalized with low SFS on the RE and with high SFS on the LE. The flash VEP was normal before and after the therapy. In conclusion, the citicoline demonstrated that it was effective in the treatment of amblyopic eye without patching. The VA and the VEP latency improvement demonstrated that the citicoline enhance the transmission of the electric impulse from retina to visual cortex. Further research is required to understand the immediate and long-term effect of coline treatment in amblyopic patients.

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

    Science.gov (United States)

    Schenk, Thomas; Milner, A David

    2006-09-01

    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. This possibility was examined in the present study. We have examined the visual form-discrimination performance of the form-agnosic patient D.F. with and without a concurrent visuomotor task, and found that her performance was significantly improved in the former condition. This suggests that the visuomotor behaviour provides cues that enhance her ability to recognize the form of the target object. In control experiments we have ruled out proprioceptive and efferent cues, and therefore propose that D.F. can, to a significant degree, access the object's visuomotor representation in the dorsal stream. Moreover, we show that the grasping-induced perceptual improvement disappears if the target objects only differ with respect to their shape but not their width. This suggests that shape information per se is not used for this grasping task.

  14. Microperimetric Biofeedback Training Improved Visual Acuity after Successful Macular Hole Surgery

    Directory of Open Access Journals (Sweden)

    Tomoko Ueda-Consolvo

    2015-01-01

    Full Text Available Purpose. To evaluate the efficacy of setting a preferred retinal locus relocation target (PRT and performing Macular Integrity Assessment (MAIA biofeedback training in patients showing insufficient recovery of best corrected visual acuity (BCVA despite successful closure of an idiopathic macular hole (MH. Methods. Retrospective interventional case series. Nine eyes of 9 consecutive patients with the decimal BCVA of less than 0.6 at more than 3 months after successful MH surgery were included. A PRT was chosen based on MAIA microperimetry and the patients underwent MAIA biofeedback training. BCVA, reading speed, fixation stability, and 63% bivariate contour ellipse area (BCEA were evaluated before and after the training. Statistical analysis was carried out using paired Student’s t-test. Results. PRT was chosen on the nasal side of the closed MH fovea in 8 patients. After the MAIA training, BCVA improved in all patients. The mean logMAR value of BCVA significantly improved from 0.33 to 0.12 (p=0.007. Reading speed improved in all patients (p=0.29, fixation stability improved in 5 patients (p=0.70, and 63% BCEA improved in 7 patients (p=0.21, although these improvements were not statistically significant. Conclusion. MAIA biofeedback training improved visual acuity in patients with insufficient recovery of BCVA after successful MH surgery.

  15. Sample to answer visualization pipeline for low-cost point-of-care blood cell counting

    Science.gov (United States)

    Smith, Suzanne; Naidoo, Thegaran; Davies, Emlyn; Fourie, Louis; Nxumalo, Zandile; Swart, Hein; Marais, Philip; Land, Kevin; Roux, Pieter

    2015-03-01

    We present a visualization pipeline from sample to answer for point-of-care blood cell counting applications. Effective and low-cost point-of-care medical diagnostic tests provide developing countries and rural communities with accessible healthcare solutions [1], and can be particularly beneficial for blood cell count tests, which are often the starting point in the process of diagnosing a patient [2]. The initial focus of this work is on total white and red blood cell counts, using a microfluidic cartridge [3] for sample processing. Analysis of the processed samples has been implemented by means of two main optical visualization systems developed in-house: 1) a fluidic operation analysis system using high speed video data to determine volumes, mixing efficiency and flow rates, and 2) a microscopy analysis system to investigate homogeneity and concentration of blood cells. Fluidic parameters were derived from the optical flow [4] as well as color-based segmentation of the different fluids using a hue-saturation-value (HSV) color space. Cell count estimates were obtained using automated microscopy analysis and were compared to a widely accepted manual method for cell counting using a hemocytometer [5]. The results using the first iteration microfluidic device [3] showed that the most simple - and thus low-cost - approach for microfluidic component implementation was not adequate as compared to techniques based on manual cell counting principles. An improved microfluidic design has been developed to incorporate enhanced mixing and metering components, which together with this work provides the foundation on which to successfully implement automated, rapid and low-cost blood cell counting tests.

  16. A visual targeting system for the microinjection of unstained adherent cells.

    Science.gov (United States)

    Becattini, Gabriele; Mattos, Leonardo S; Caldwell, Darwin G

    2013-02-01

    Automatic localization and targeting are critical steps in automating the process of microinjecting adherent cells. This process is currently performed manually by highly trained operators and is characterized as a laborious task with low success rate. Therefore, automation is desired to increase the efficiency and consistency of the operations. This research offers a contribution to this procedure through the development of a vision system for a robotic microinjection setup. Its goals are to automatically locate adherent cells in a culture dish and target them for a microinjection. Here the major concern was the achievement of an error-free targeting system to guarantee high consistency in microinjection experiments. To accomplish this, a novel visual targeting algorithm integrating different image processing techniques was proposed. This framework employed defocusing microscopy to highlight cell features and improve cell segmentation and targeting reliability. Three main image processing techniques, operating at three different focus levels in a bright field (BF) microscope, were used: an anisotropic contour completion (ACC) method, a local intensity variation background-foreground classifier, and a grayscale threshold-based segmentation. The proposed framework combined information gathered by each of these methods using a validation map and this was shown to provide reliable cell targeting results. Experiments conducted with sets of real images from two different cell lines (CHO-K1 and HEK), which contained a total of more than 650 cells, yielded flawless targeting results along with a cell detection ratio greater than 50%.

  17. Improving Target Detection in Visual Search Through the Augmenting Multi-Sensory Cues

    Science.gov (United States)

    2013-01-01

    target detection, visual search James Merlo , Joseph E. Mercado, Jan B.F. Van Erp, Peter A. Hancock University of Central Florida 12201 Research Parkway...cued control condition (e.g. Fisher et al. 1989; Fisher and Tan 1989; Hofer, Palen, and Possolo 1993; Merlo and Hancock 2011; Sklar and Sarter 1999...by the improvements encountered in bi-modal forms of presentation ( Merlo , Duley, and Hancock 2010) and thus the present extension into the exploration

  18. Elbow arthroscopy: a new setup to avoid visual paradox and improve triangulation.

    Science.gov (United States)

    Sinha, Apurv; Pydah, Satya Kanth V; Webb, Mark

    2013-05-01

    Elbow arthroscopy is a useful diagnostic and therapeutic tool for various conditions. Conventional arthroscopy with the patient in the prone or lateral position where the screen is placed on the opposite side makes it difficult to interpret the image, results in visual paradox, and is associated with difficult triangulation. We present a modified setup for the operating room to help eliminate these problems and improve triangulation.

  19. 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.

  20. 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.

  1. Nonvisual motor learning improves visual motion perception: evidence from violating the two-thirds power law.

    Science.gov (United States)

    Beets, I A M; Rösler, F; Fiehler, K

    2010-09-01

    Few studies have reported direct effects of motor learning on visual perception, especially when using novel movements for the motor system. Atypical motor behaviors that violate movement constraints provide an excellent opportunity to study action-to-perception transfer. In our study, we passively trained blindfolded participants on movements violating the 2/3 power law. Before and after motor training, participants performed a visual discrimination task in which they decided whether two consecutive movements were same or different. For motor training, we randomly assigned the participants to two motor training groups or a control group. The motor training group experienced either a weak or a strong elliptic velocity profile on a circular trajectory that matched one of the visual test stimuli. The control group was presented with linear trajectories unrelated to the viewed movements. After each training session, participants actively reproduced the movement to assess motor learning. The group trained on the strong elliptic velocity profile reproduced movements with increasing elliptic velocity profiles while circular geometry remained constant. Furthermore, both training groups improved in visual discrimination ability for the learned movement as well as for highly similar movements. Participants in the control group, however, did not show any improvements in the visual discrimination task nor did participants who did not acquire the trained movement. The present results provide evidence for a transfer from action to perception which generalizes to highly related movements and depends on the success of motor learning. Moreover, under specific conditions, it seems to be possible to acquire movements deviating from the 2/3 power law.

  2. 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.

  3. Significant improvement in dynamic visual acuity after cataract surgery: a promising potential parameter for functional vision.

    Directory of Open Access Journals (Sweden)

    Mingxin Ao

    Full Text Available PURPOSE: Dynamic visual acuity (DVA is a relatively independent parameter for evaluating the ability to distinguish details of a moving target. The present study has been designed to discuss the extent to which age-related cataract impacts DVA in elderly individuals and to determine whether it could be restored after bilateral phacoemulsification combined with intraocular lens implantation surgery. METHODS: Twenty-six elderly cataract patients scheduled for binocular cataract surgery and 30 elderly volunteers without cataract were enrolled in the study. DVA at 15, 30, 60 and 90 degree per second (dps was assessed, and velocity-dependent visual acuity decreases between consecutive speed levels were calculated. RESULTS: Compared with the control group, the patient group exhibited significantly worse DVA performance at all speed levels (p<0.001, and the decreases in velocity-dependent visual acuity were more serious in the patient group at the intervals of 0-15 dps (p<0.001, 15-30 dps (p = 0.007 and 30-60 dps (p = 0.008. Postoperatively, DVA performance at every speed level in the patient group clearly improved (p<0.001 and recovered to levels compatible to the control group. The decrease in visual acuity with increasing speed was less pronounced than during the preoperative phase (p0-15 dps = 0.001, p15-30 dps<0.001 and p30-60 dps = 0.001 and became similar to that of the control group. The postoperative visual benefit regarding DVA was more pronounced than the improvement in static visual acuity (p15 dps = 0.001 and p<0.001 at 30 dps, 60 dps and 90 dps. CONCLUSIONS: The impact of age-related cataract on DVA was more severe than its effects on static visual acuity. After cataract surgery, not only static vision of the patients was restored markedly, but also the dynamic vision. DVA could be an important adjunct to the current evaluation system of functional vision, thereby meriting additional attention in clinical assessment.

  4. Playing shooter and driving videogames improves top-down guidance in visual search.

    Science.gov (United States)

    Wu, Sijing; Spence, Ian

    2013-05-01

    Playing action videogames is known to improve visual spatial attention and related skills. Here, we showed that playing action videogames also improves classic visual search, as well as the ability to locate targets in a dual search that mimics certain aspects of an action videogame. In Experiment 1A, first-person shooter (FPS) videogame players were faster than nonplayers in both feature search and conjunction search, and in Experiment 1B, they were faster and more accurate in a peripheral search and identification task while simultaneously performing a central search. In Experiment 2, we showed that 10 h of play could improve the performance of nonplayers on each of these tasks. Three different genres of videogames were used for training: two action games and a 3-D puzzle game. Participants who played an action game (either an FPS or a driving game) achieved greater gains on all search tasks than did those who trained using the puzzle game. Feature searches were faster after playing an action videogame, suggesting that players developed a better target template to guide search in a top-down manner. The results of the dual search suggest that, in addition to enhancing the ability to divide attention, playing an action game improves the top-down guidance of attention to possible target locations. The results have practical implications for the development of training tools to improve perceptual and cognitive skills.

  5. Molten carbonate fuel cell technology improvement

    Energy Technology Data Exchange (ETDEWEB)

    1991-06-01

    This report summarizes the work performed under Department of Energy Contract DEAC21-87MC23270, Molten Carbonate Fuel Cell Technology Improvement.'' This work was conducted over a three year period and consisted of three major efforts. The first major effort was the power plant system study which reviewed the competitive requirements for a coal gasifier/molten carbonate fuel cell power plant, produced a conceptual design of a CG/MCFC, and defined the technology development requirements. This effort is discussed in Section 1 of the report. The second major effort involved the design and development of a new MCFC cell configuration which reduced the material content of the cell to a level competitive with competing power plants, simplified the cell configuration to make the components more manufacturable and adaptable to continuous low cost processing techniques, and introduced new-low-pressure drop flow fields for both reactant gases. The new flow fields permitted the incorporation of recirculation systems in both reactant gas systems, permitting simplified cooling techniques and the ability to operate on both natural gas and a wide variety of gasifier fuels. This cell technology improvement is discussed in Section 2. The third major effort involved the scaleup of the new cell configuration to the full-area, 8-sq-ft size and resulted in components used for a 25-kW, 20-cell stack verification test. The verification test was completed with a run of 2200 hours, exceeding the goal of 2000 hours and verifying the new cell design. TWs test, in turn, provided the confidence to proceed to a 100-kW demonstration which is the goal of the subsequent DOE program. The scaleup and stack verification tests are discussed in Sections 3, 4, 5, and 6 of this report.

  6. 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...

  7. 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

  8. 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.

  9. Improved Visualization of Alphitobius diaperinus (Panzer (Coleoptera: Tenebrionidae—Part II: Alimentary Canal Components and Measurements

    Directory of Open Access Journals (Sweden)

    Tawni L. Crippen

    2012-01-01

    Full Text Available Alphitobius diaperinus (Panzer (Coleoptera: Tenebrionidae is a pest of stored food products and problematic to every type of poultry production facility. Larvae and adults can ingest and harbor foodborne and poultry pathogens. Determining the efficiency of this insect’s capacity to transmit disease is critical to improving management of A. diaperinus on poultry facilities and providing a safe food supply for human consumption. However, a deficiency exists in the literature reporting measurements of the gut and its defined segments. Previous reports include line drawing depictions, which aid little in the determination of the pathogen reservoir potential of these insects. Advances in technology allowed more accurate visualization and precise measurement of gross anatomical features of the alimentary canal. A photographic depiction to aid the researcher in the visualization of anatomical features and accurate measurements of the alimentary canal for these insects is presented here.

  10. Cell exclusion in couette flow: evaluation through flow visualization and mechanical forces.

    Science.gov (United States)

    Leslie, Laura J; Marshall, Lindsay J; Devitt, Andrew; Hilton, Andrew; Tansley, Geoff D

    2013-03-01

    Cell exclusion is the phenomenon whereby the hematocrit and viscosity of blood decrease in areas of high stress. While this is well known in naturally occurring Poiseuille flow in the human body, it has never previously been shown in Couette flow, which occurs in implantable devices including blood pumps. The high-shear stresses that occur in the gap between the boundaries in Couette flow are known to cause hemolysis in erythrocytes. We propose to mitigate this damage by initiating cell exclusion through the use of a spiral-groove bearing (SGB) that will provide escape routes by which the cells may separate themselves from the plasma and the high stresses in the gap. The force between two bearings (one being the SGB) in Couette flow was measured. Stained erythrocytes, along with silver spheres of similar diameter to erythrocytes, were visualized across a transparent SGB at various gap heights. A reduction in the force across the bearing for human blood, compared with fluids of comparable viscosity, was found. This indicates a reduction in the viscosity of the fluid across the bearing due to a lowered hematocrit because of cell exclusion. The corresponding images clearly show both cells and spheres being excluded from the gap by entering the grooves. This is the first time the phenomenon of cell exclusion has been shown in Couette flow. It not only furthers our understanding of how blood responds to different flows but could also lead to improvements in the future design of medical devices.

  11. 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.

  12. Real-Time Visualization and Quantification of Contractile Ring Proteins in Single Living Cells

    Science.gov (United States)

    Davidson, Reshma; Liu, Yajun; Gerien, Kenneth S.; Wu, Jian-Qiu

    2017-01-01

    Single-cell microscopy provides a powerful tool to visualize cellular and subcellular processes in wild-type and mutant cells by observing fluorescently tagged proteins. Here, we describe three simple methods to visualize fission yeast cells: gelatin slides, coverslip-bottom dishes, and tetrad fluorescence microscopy. These imaging methods and data analysis using free software make it possible to quantify protein localization, dynamics, and concentration with high spatial and temporal resolution. In fission yeast, the actomyosin contractile ring is essential for cytokinesis. We use the visualization and quantification of contractile ring proteins as an example to demonstrate how to use these methods. PMID:26519302

  13. Real-Time Visualization and Quantification of Contractile Ring Proteins in Single Living Cells.

    Science.gov (United States)

    Davidson, Reshma; Liu, Yajun; Gerien, Kenneth S; Wu, Jian-Qiu

    2016-01-01

    Single-cell microscopy provides a powerful tool to visualize cellular and subcellular processes in wild-type and mutant cells by observing fluorescently tagged proteins. Here, we describe three simple methods to visualize fission yeast cells: gelatin slides, coverslip-bottom dishes, and tetrad fluorescence microscopy. These imaging methods and data analysis using free software make it possible to quantify protein localization, dynamics, and concentration with high spatial and temporal resolution. In fission yeast, the actomyosin contractile ring is essential for cytokinesis. We use the visualization and quantification of contractile ring proteins as an example to demonstrate how to use these methods.

  14. Enhanced stimulus strength improves visual cognition in aging and Alzheimer's disease.

    Science.gov (United States)

    Cronin-Golomb, Alice; Gilmore, Grover C; Neargarder, Sandy; Morrison, Sarah R; Laudate, Thomas M

    2007-10-01

    Deficits in visual cognition in Alzheimer's disease (AD) arise from neuropathological changes in higher-order association areas of the cortex and from defective input from lower-level visual processing areas. We investigated whether enhanced signal strength may lead to improvement of visual cognition in AD. We tested 35 individuals with probable AD, 35 age-matched elderly control (EC) and 58 young control (YC) adults on letter identification, word reading, picture naming, discrimination of unfamiliar faces, and pattern completion. The contrast sensitivity step-difference across an independent sample of AD and EC groups was used in calculating an image filter, from which we produced stimulus-strength conditions of low-degraded, medium-normal, and high-enhanced. Using this filter we created a hypothetical proximal-strength equivalence between AD at medium strength and EC at low strength, and between AD at high strength and EC at medium strength. For letter identification, word reading, picture naming, and face discrimination, medium strength elicited AD accuracy levels and reaction times that were similar to those of EC at low strength. On picture naming, increased strength reduced perceptual-type errors for EC and AD and random errors for AD. For word reading, high strength elicited AD accuracy levels and reaction times that were equivalent to those of EC at medium strength. We saw no effect of signal-strength manipulation on performance of pattern completion, possibly owing to the complex cognitive demands of that task or to the inadequacy of the filter for its images. The results indicate that putative AD-EC differences in cognition directly reflect contrast sensitivity differences between the groups. Enhancement of stimulus strength can ameliorate vision-based deficits and lead to improvement in some aspects of cognitive performance. These results suggest new non-pharmacological avenues to explore in the attempt to improve cognition in elderly adults and

  15. 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.)

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

    Science.gov (United States)

    Laurence, Stuart J.; Karl, Sebastian

    2010-06-01

    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 ˜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.

  17. 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...

  18. Improvement of visual debugging tool. Shortening the elapsed time for getting data and adding new functions to compare/combine a set of visualized data

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Katsuyuki; Takemiya, Hiroshi

    2001-03-01

    The visual debugging tool 'vdebug' has been improved, which was designed for the debugging of programs for scientific computing. Improved were the following two points; (1) shortening the elapsed time required for getting appropriate data to visualize; (2) adding new functions which enable to compare and/or combine a set of visualized data originated from two or more different programs. As for shortening elapsed time for getting data, with the improved version of 'vdebug', we could achieve the following results; over hundred times shortening the elapsed time with dbx, pdbx of SX-4 and over ten times with ndb of SR2201. As for the new functions to compare/combine visualized data, it was confirmed that we could easily checked the consistency between the computational results obtained in each calculational steps on two different computers: SP and ONYX. In this report, we illustrate how the tool 'vdebug' has been improved with an example. (author)

  19. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    Energy Technology Data Exchange (ETDEWEB)

    H.C. Maru; M. Farooque

    2003-03-01

    The program efforts are focused on technology and system optimization for cost reduction, commercial design development, and prototype system field trials. The program is designed to advance the carbonate fuel cell technology from full-size field test to the commercial design. FuelCell Energy, Inc. (FCE) is in the later stage of the multiyear program for development and verification of carbonate fuel cell based power plants supported by DOE/NETL with additional funding from DOD/DARPA and the FuelCell Energy team. FCE has scaled up the technology to full-size and developed DFC{reg_sign} stack and balance-of-plant (BOP) equipment technology to meet product requirements, and acquired high rate manufacturing capabilities to reduce cost. FCE has designed submegawatt (DFC300A) and megawatt (DFC1500 and DFC3000) class fuel cell products for commercialization of its DFC{reg_sign} technology. A significant progress was made during the reporting period. The reforming unit design was optimized using a three-dimensional stack simulation model. Thermal and flow uniformities of the oxidant-In flow in the stack module were improved using computational fluid dynamics based flow simulation model. The manufacturing capacity was increased. The submegawatt stack module overall cost was reduced by {approx}30% on a per kW basis. An integrated deoxidizer-prereformer design was tested successfully at submegawatt scale using fuels simulating digester gas, coal bed methane gas and peak shave (natural) gas.

  20. Visiting Richard Serra's "Promenade" sculpture improves postural control and judgment of subjective visual vertical.

    Science.gov (United States)

    Kapoula, Zoï; Lang, Alexandre; Lê, Thanh-Thuan; Adenis, Marie-Sarah; Yang, Qing; Lipede, Gabi; Vernet, Marine

    2014-01-01

    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 hypothesized to have stimulated the body's vertical and longitudinal axes as it showcased five monumental rectangular solids pitched at a 1.69(°) angle. Using computerized 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 canceling time (CT) of body sway] at the expense of medio-lateral stability (in terms of CT). Moreover, a medio-lateral instability associated with eye movement exploration before the promenade (in terms of body sway sensu stricto) was canceled after the promenade. Finally, the overall medio-lateral stability (in terms of spectral power) increased after the promenade. Fourteen additional visitors were asked to stand 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.

  1. 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.

  2. 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.

  3. 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.

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

    Science.gov (United States)

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

    2013-07-01

    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; all three intervention groups improved significantly more than no-contact controls. There was a lack of difference between the two game conditions, differing from findings with younger adults. Discussion considers whether games posing less challenge might still be effective interventions for elders, and whether optimal training dosages should be higher.

  5. Forging partnerships between optometrists and ergonomists to improve visual comfort and productivity in the workplace.

    Science.gov (United States)

    Long, Jennifer

    2014-01-01

    Ergonomists and optometrists often have mutual clients/patients with complex visual needs in the workplace but communication between the professionals is usually indirect through the client/patient. This paper describes a joint professional development meeting between optometrists and ergonomists in Canberra, Australia, which included a discussion to explore how to improve communication between the two professions. Optometrists and ergonomists reported they would prefer more information before conducting assessments and providing advice. Vision screening forms commonly in use for computer workers were viewed as inadequate to meet these needs. Communication between the two professions was hampered by absence of contact details of the optometrist/ergonomist, perceptions that the other profession is too busy to talk, privacy considerations in sharing information and funding issues for shared care arrangements. There are opportunities for increasing awareness of good vision in workplaces. Communication between optometrists and ergonomists can be improved by developing information-sharing documents relevant to modern workplaces.

  6. 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.

  7. Functional clustering drives encoding improvement in a developing brain network during awake visual learning.

    Directory of Open Access Journals (Sweden)

    Kaspar Podgorski

    2012-01-01

    Full Text Available Sensory experience drives dramatic structural and functional plasticity in developing neurons. However, for single-neuron plasticity to optimally improve whole-network encoding of sensory information, changes must be coordinated between neurons to ensure a full range of stimuli is efficiently represented. Using two-photon calcium imaging to monitor evoked activity in over 100 neurons simultaneously, we investigate network-level changes in the developing Xenopus laevis tectum during visual training with motion stimuli. Training causes stimulus-specific changes in neuronal responses and interactions, resulting in improved population encoding. This plasticity is spatially structured, increasing tuning curve similarity and interactions among nearby neurons, and decreasing interactions among distant neurons. Training does not improve encoding by single clusters of similarly responding neurons, but improves encoding across clusters, indicating coordinated plasticity across the network. NMDA receptor blockade prevents coordinated plasticity, reduces clustering, and abolishes whole-network encoding improvement. We conclude that NMDA receptors support experience-dependent network self-organization, allowing efficient population coding of a diverse range of stimuli.

  8. GFP-specific CD8 T cells enable targeted cell depletion and visualization of T-cell interactions.

    Science.gov (United States)

    Agudo, Judith; Ruzo, Albert; Park, Eun Sook; Sweeney, Robert; Kana, Veronika; Wu, Meng; Zhao, Yong; Egli, Dieter; Merad, Miriam; Brown, Brian D

    2015-12-01

    There are numerous cell types with scarcely understood functions, whose interactions with the immune system are not well characterized. To facilitate their study, we generated a mouse bearing enhanced green fluorescent protein (EGFP)-specific CD8(+) T cells. Transfer of the T cells into EGFP reporter animals can be used to kill EGFP-expressing cells, allowing selective depletion of desired cell types, or to interrogate T-cell interactions with specific populations. Using this system, we eliminate a rare EGFP-expressing cell type in the heart and demonstrate its role in cardiac function. We also show that naive T cells are recruited into the mouse brain by antigen-expressing microglia, providing evidence of an immune surveillance pathway in the central nervous system. The just EGFP death-inducing (Jedi) T cells enable visualization of a T-cell antigen. They also make it possible to utilize hundreds of existing EGFP-expressing mice, tumors, pathogens and other tools, to study T-cell interactions with many different cell types, to model disease states and to determine the functions of poorly characterized cell populations.

  9. Molten carbonate fuel cell product design improvement

    Energy Technology Data Exchange (ETDEWEB)

    P. Voyentzie; T. Leo; A. Kush; L. Christner; G. Carlson; C. Yuh

    1998-12-20

    Drawing on the manufacture, field test, and post-test experience of the sixteen Santa Clara Demonstration Project (SCDP) stacks, ERC is finalizing the next generation commercial entry product design. The second generation cells are 50% larger in area, 40% lighter on equal geometric area basis, and 30% thinner than the earlier design. These improvements have resulted in doubling of the full-height stack power. A low-cost and high-strength matrix has also been developed for improving product ruggedness. The low-cost advanced cell design incorporating these improvements has been refined through six short stack tests. Power production per cell of two times the SCDP maximum power operation, over ten thermal cycles, and overall operating flexibility with respect to load and thermal changes have been demonstrated in these short stack tests. An internally insulated stack enclosure has been designed and fabricated to eliminate the need for an inert gas environment during operation. ERC has acquired the capability for testing 400kW full-height direct fuel ceil (DFC) stack and balance-of-plant equipment. With the readiness of the power plant test facility, the cell package design, and the stack module, full-height stack testing has begun. The first full- height stack incorporating the post-SCDP second generation design was completed. The stack reached a power level of 253 kW, setting a world record for the highest power production from the advanced fuel cell system. Excellent performance uniformity at this power level affirmed manufacturing reproducibility of the components at the factory. This unoptimized small size test has achieved pipeline natural gas to DC electricity conversion efficiency of 47% (based on lower heating value - LHV) including the parasitic power consumed by the BOP equipment; that should translate to more than 50% efficiency in commercial operation, before employing cogeneration. The power plant system also operated smoothly. With the success of this

  10. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Bivins, Gerrick O' Ron [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    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, ~ 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Bivins, Gerrick O' Ron [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    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, ~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.

  13. 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

  14. Ontogenetic cell death and phagocytosis in the visual system of vertebrates.

    Science.gov (United States)

    Francisco-Morcillo, Javier; Bejarano-Escobar, Ruth; Rodríguez-León, Joaquín; Navascués, Julio; Martín-Partido, Gervasio

    2014-10-01

    Programmed cell death (PCD), together with cell proliferation, cell migration, and cell differentiation, is an essential process during development of the vertebrate nervous system. The visual system has been an excellent model on which to investigate the mechanisms involved in ontogenetic cell death. Several phases of PCD have been reported to occur during visual system ontogeny. During these phases, comparative analyses demonstrate that dying cells show similar but not identical spatiotemporally restricted patterns in different vertebrates. Additionally, the chronotopographical coincidence of PCD with the entry of specialized phagocytes in some regions of the developing vertebrate visual system suggests that factors released from degenerating cells are involved in the cell migration of macrophages and microglial cells. Contradicting this hypothesis however, in many cases the cell corpses generated during degeneration are rapidly phagocytosed by neighboring cells, such as neuroepithelial cells or Müller cells. In this review, we describe the occurrence and the sites of PCD during the morphogenesis and differentiation of the retina and optic pathways of different vertebrates, and discuss the possible relationship between PCD and phagocytes during ontogeny.

  15. 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.

  16. 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.

  17. Improved Visual Hook Capturing and Tracking for Precision Hoisting of Tower Crane

    Directory of Open Access Journals (Sweden)

    Yanming Li

    2013-01-01

    Full Text Available To maintain safe operation of the tower crane, it is important to monitor the activities of the hook system. Visual monitoring and image recognition are the optimum methods for crane hook tracking and precision hoisting. High real-time performance and low computation requirements are required for tower crane hook capturing and tracking system which is implemented on the embedded Advanced RISC Machines (ARM processor or Microcontrol Unit (MCU. Using the lift rope of a tower crane as the target object, a new high-performance hook tracking method suitble for ARM processor or MCU applications is presented. The features of the lifting process are analyzed, and an improved progressive probabilistic Hough transform (IPPHT algorithm is proposed which canreduce capturing time by up to 80%. Combining color histogram with a binary search algorithm, an adaptive zooming method for precise hoisting is presented. Using this method the optimum zoom scale can be achieved within a few iterations.

  18. Improved dimensionally-reduced visual cortical network using stochastic noise modeling.

    Science.gov (United States)

    Tao, Louis; Praissman, Jeremy; Sornborger, Andrew T

    2012-04-01

    In this paper, we extend our framework for constructing low-dimensional dynamical system models of large-scale neuronal networks of mammalian primary visual cortex. Our dimensional reduction procedure consists of performing a suitable linear change of variables and then systematically truncating the new set of equations. The extended framework includes modeling the effect of neglected modes as a stochastic process. By parametrizing and including stochasticity in one of two ways we show that we can improve the systems-level characterization of our dimensionally reduced neuronal network model. We examined orientation selectivity maps calculated from the firing rate distribution of large-scale simulations and stochastic dimensionally reduced models and found that by using stochastic processes to model the neglected modes, we were able to better reproduce the mean and variance of firing rates in the original large-scale simulations while still accurately predicting the orientation preference distribution.

  19. Visualizing stressful aspects of repetitive motion tasks and opportunities for ergonomic improvements using computer vision.

    Science.gov (United States)

    Greene, Runyu L; Azari, David P; Hu, Yu Hen; Radwin, Robert G

    2017-03-09

    Patterns of physical stress exposure are often difficult to measure, and the metrics of variation and techniques for identifying them is underdeveloped in the practice of occupational ergonomics. Computer vision has previously been used for evaluating repetitive motion tasks for hand activity level (HAL) utilizing conventional 2D videos. The approach was made practical by relaxing the need for high precision, and by adopting a semi-automatic approach for measuring spatiotemporal characteristics of the repetitive task. In this paper, a new method for visualizing task factors, using this computer vision approach, is demonstrated. After videos are made, the analyst selects a region of interest on the hand to track and the hand location and its associated kinematics are measured for every frame. The visualization method spatially deconstructs and displays the frequency, speed and duty cycle components of tasks that are part of the threshold limit value for hand activity for the purpose of identifying patterns of exposure associated with the specific job factors, as well as for suggesting task improvements. The localized variables are plotted as a heat map superimposed over the video, and displayed in the context of the task being performed. Based on the intensity of the specific variables used to calculate HAL, we can determine which task factors most contribute to HAL, and readily identify those work elements in the task that contribute more to increased risk for an injury. Work simulations and actual industrial examples are described. This method should help practitioners more readily measure and interpret temporal exposure patterns and identify potential task improvements.

  20. 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.

  1. Cell types, circuits, and receptive fields in the mouse visual cortex.

    Science.gov (United States)

    Niell, Cristopher M

    2015-07-08

    Over the past decade, the mouse has emerged as an important model system for studying cortical function, owing to the advent of powerful tools that can record and manipulate neural activity in intact neural circuits. This advance has been particularly prominent in the visual cortex, where studies in the mouse have begun to bridge the gap between cortical structure and function, allowing investigators to determine the circuits that underlie specific visual computations. This review describes the advances in our understanding of the mouse visual cortex, including neural coding, the role of different cell types, and links between vision and behavior, and discusses how recent findings and new approaches can guide future studies.

  2. 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...... population, namely, ESCs at an early stage of differentiation, and this revealed that the bivalent modification disappeared in a highly concerted manner, whereas phenotypic differentiation proceeded with large variations among cells. Also, using this method, we were able to visualize a combination...

  3. A visual tracking method based on improved online multiple instance learning

    Science.gov (United States)

    He, Xianhui; Wei, Yuxing

    2016-09-01

    Visual tracking is an active research topic in the field of computer vision and has been well studied in the last decades. The method based on multiple instance learning (MIL) was recently introduced into the tracking task, which can solve the problem that template drift well. However, MIL method has relatively poor performance in running efficiency and accuracy, due to its strong classifiers updating strategy is complicated, and the speed of the classifiers update is not always same with the change of the targets' appearance. In this paper, we present a novel online effective MIL (EMIL) tracker. A new update strategy for strong classifier was proposed to improve the running efficiency of MIL method. In addition, to improve the t racking accuracy and stability of the MIL method, a new dynamic mechanism for learning rate renewal of the classifier and variable search window were proposed. Experimental results show that our method performs good performance under the complex scenes, with strong stability and high efficiency.

  4. Improving the extent of malignant glioma resection by dual intraoperative visualization approach.

    Directory of Open Access Journals (Sweden)

    Ilker Y Eyüpoglu

    Full Text Available Despite continuing debates around cytoreductive surgery in malignant gliomas, there is broad consensus that increased extent of tumor reduction improves overall survival. However, maximization of the extent of tumor resection is hampered by difficulty in intraoperative discrimination between normal and pathological tissue. In this context, two established methods for tumor visualization, fluorescence guided surgery with 5-ALA and intraoperative MRI (iMRI with integrated functional neuronavigation were investigated as a dual intraoperative visualization (DIV approach. Thirty seven patients presumably suffering from malignant gliomas (WHO grade III or IV according to radiological appearance were included. Twenty-one experimental sequences showing complete resection according to the 5-ALA technique were confirmed by iMRI. Fourteen sequences showing complete resection according to the 5-ALA technique could not be confirmed by iMRI, which detected residual tumor. Further analysis revealed that these sequences could be classified as functional grade II tumors (adjacent to eloquent brain areas. The combination of fluorescence guided resection and intraoperative evaluation by high field MRI significantly increased the extent of tumor resection in this subgroup of malignant gliomas located adjacent to eloquent areas from 61.7% to 100%; 5-ALA alone proved to be insufficient in attaining gross total resection without the danger of incurring postoperative neurological deterioration. Furthermore, in the case of functional grade III gliomas, iMRI in combination with functional neuronavigation was significantly superior to the 5-ALA resection technique. The extent of resection could be increased from 57.1% to 71.2% without incurring postoperative neurological deficits.

  5. Indexing Large Visual Vocabulary by Randomized Dimensions Hashing for High Quantization Accuracy: Improving the Object Retrieval Quality

    Science.gov (United States)

    Yang, Heng; Wang, Qing; He, Zhoucan

    The bag-of-visual-words approach, inspired by text retrieval methods, has proven successful in achieving high performance in object retrieval on large-scale databases. A key step of these methods is the quantization stage which maps the high-dimensional image feature vectors to discriminatory visual words. In this paper, we consider the quantization step as the nearest neighbor search in large visual vocabulary, and thus proposed a randomized dimensions hashing (RDH) algorithm to efficiently index and search the large visual vocabulary. The experimental results have demonstrated that the proposed algorithm can effectively increase the quantization accuracy compared to the vocabulary tree based methods which represent the state-of-the-art. Consequently, the object retrieval performance can be significantly improved by our method in the large-scale database.

  6. Easy and Rapid Detection of Mumps Virus by Live Fluorescent Visualization of Virus-Infected Cells.

    Directory of Open Access Journals (Sweden)

    Tadanobu Takahashi

    Full Text Available Mumps viruses show diverse cytopathic effects (CPEs of infected cells and viral plaque formation (no CPE or no plaque formation in some cases depending on the viral strain, highlighting the difficulty in mumps laboratory studies. In our previous study, a new sialidase substrate, 2-(benzothiazol-2-yl-4-bromophenyl 5-acetamido-3,5-dideoxy-α-D-glycero-D-galacto-2-nonulopyranosidonic acid (BTP3-Neu5Ac, was developed for visualization of sialidase activity. BTP3-Neu5Ac can easily and rapidly perform histochemical fluorescent visualization of influenza viruses and virus-infected cells without an antiviral antibody and cell fixation. In the present study, the potential utility of BTP3-Neu5Ac for rapid detection of mumps virus was demonstrated. BTP3-Neu5Ac could visualize dot-blotted mumps virus, virus-infected cells, and plaques (plaques should be called focuses due to staining of infected cells in this study, even if a CPE was not observed. Furthermore, virus cultivation was possible by direct pick-up from a fluorescent focus. In conventional methods, visible appearance of the CPE and focuses often requires more than 6 days after infection, but the new method with BTP3-Neu5Ac clearly visualized infected cells after 2 days and focuses after 4 days. The BTP3-Neu5Ac assay is a precise, easy, and rapid assay for confirmation and titration of mumps virus.

  7. Retinal ganglion cell density of the black rhinoceros (Diceros bicornis): calculating visual resolution.

    Science.gov (United States)

    Pettigrew, John D; Manger, Paul R

    2008-01-01

    A single right retina from a black rhinoceros was whole mounted, stained and analyzed to determine the visual resolution of the rhinoceros, an animal with reputedly poor eyesight. A range of small (15-microm diameter) to large (100-microm diameter) ganglion cell types was seen across the retina. We observed two regions of high density of retinal ganglion cells at either end of a long, but thin, horizontal streak. The temporal specialization, which receives light from the anterior visual field, exhibited a ganglion cell density of approximately 2000/mm2, while the nasal specialization exhibited a density of approximately 1500/mm2. The retina exhibited a ganglion cell density bias toward the upper half, especially so, the upper temporal quadrant, indicating that the rhinoceros would be processing visual information from the visual field below the anterior horizon for the most part. Our calculations indicate that the rhinoceros has a visual resolution of 6 cycles/degree. While this resolution is one-tenth that of humans (60 cycles/deg) and less than that of the domestic cat (9 cycles/deg), it is comparable to that of the rabbit (6 cycles/deg), and exceeds that seen in a variety of other mammals including seals, dolphins, microbats, and rats. Thus, the reputation of the rhinoceros as a myopic, weakly visual animal is not supported by our observations of the retina. We calculate that the black rhinoceros could readily distinguish a 30 cm wide human at a distance of around 200 m given the appropriate visual background.

  8. Direct visualization of cell division using high-resolution imaging of M-phase of the cell cycle

    OpenAIRE

    Hesse, Michael; Raulf, Alexandra; Pilz, Gregor-Alexander; Haberlandt, Christian; Klein, Alexandra M; Jabs, Ronald; Zaehres, Holm; Fügemann, Christopher J.; Zimmermann, Katrin; Trebicka, Jonel; Welz, Armin; Pfeifer, Alexander; Röll, Wilhelm; Kotlikoff, Michael I.; Steinhäuser, Christian

    2012-01-01

    Current approaches to monitor and quantify cell division in live cells, and reliably distinguish between acytokinesis and endoreduplication, are limited and complicate determination of stem cell pool identities. Here we overcome these limitations by generating an in vivo reporter system using the scaffolding protein anillin fused to enhanced green fluorescent protein, to provide high spatiotemporal resolution of mitotic phase. This approach visualizes cytokinesis and midbody formation as hall...

  9. 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.

  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. 1Click1View: Interactive Visualization Methodology for RNAi Cell-Based Microscopic Screening

    Directory of Open Access Journals (Sweden)

    Lukasz Zwolinski

    2013-01-01

    Full Text Available Technological advancements are constantly increasing the size and complexity of data resulting from large-scale RNA interference screens. This fact has led biologists to ask complex questions, which the existing, fully automated analyses are often not adequate to answer. We present a concept of 1Click1View (1C1V as a methodology for interactive analytic software tools. 1C1V can be applied for two-dimensional visualization of image-based screening data sets from High Content Screening (HCS. Through an easy-to-use interface, one-click, one-view concept, and workflow based architecture, visualization method facilitates the linking of image data with numeric data. Such method utilizes state-of-the-art interactive visualization tools optimized for fast visualization of large scale image data sets. We demonstrate our method on an HCS dataset consisting of multiple cell features from two screening assays.

  12. Analysis and visualization of cell movement in the developing zebrafish brain.

    Science.gov (United States)

    Langenberg, Tobias; Dracz, Tadeusz; Oates, Andrew C; Heisenberg, Carl-Philip; Brand, Michael

    2006-04-01

    Detailed reconstruction of the spatiotemporal history of embryonic cells is key to understanding tissue formation processes but is often complicated by the large number of cells involved, particularly so in vertebrates. Through a combination of high-resolution time-lapse lineage tracing and antibody staining, we have analyzed the movement of mesencephalic and metencephalic cell populations in the early zebrafish embryo. To facilitate the analysis of our cell tracking data, we have created TracePilot, a software tool that allows interactive manipulation and visualization of tracking data. We demonstrate its utility by showing novel visualizations of cell movement in the developing zebrafish brain. TracePilot (http://www.mpi-cbg.de/tracepilot) is Java-based, available free of charge, and has a program structure that allows the incorporation of additional analysis tools.

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

    Directory of Open Access Journals (Sweden)

    Yang Zhou

    2016-01-01

    Full Text Available 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.

  14. Improving the visual field in coronary artery by with non-obstructive angioscopy: dual infusion method.

    Science.gov (United States)

    Komatsu, Sei; Ohara, Tomoki; Takahashi, Satoru; Takewa, Mitsuhiko; Yutani, Chikao; Kodama, Kazuhisa

    2017-02-07

    Non-obstructive angioscopy (NOA) is used to visualize the surface of the coronary artery, and a clear visual field is obtained by injecting transparent fluid into the gap between the probing catheter and the fiber. This study examines visual field expansion by a dual infusion method, which involves an infusion from the probing and guiding catheters, and the relationships between visual grade and vessel characteristics. Thirty-two patients and thirty patients performed coronary plaque analysis with NOA using the conventional method and the novel dual infusion method, respectively. Images were blindly analyzed retrospectively. Visual fields were assessed from image slices using a 5-point scale (0 = invisible, 1 = poor, 2 = adequate, 3 = good, 4 = excellent) at 5-s intervals. The relationships between visual grade and vessel characteristics were analyzed using multiple stepwise linear regression analysis. The mean visual grade, "excellent" ratio, and "adequate" ratio were significantly higher using the dual infusion method than those obtained using the conventional method (p = 0.003, p = 0.004, and p = 0.005 respectively). The "invisible" ratio was significantly lower using the dual infusion method than the conventional method (p = 0.027). The visual field was negatively associated with the conventional method (β  = -0.154, p visual field with NOA can be effectively expanded by the dual infusion method.

  15. The role of starburst amacrine cells in visual signal processing

    Science.gov (United States)

    TAYLOR, W.R.; SMITH, R.G.

    2012-01-01

    Starburst amacrine cells (SBACs) within the adult mammalian retina provide the critical inhibition that underlies the receptive field properties of direction-selective ganglion cells (DSGCs). The SBACs generate direction-selective output of GABA that differentially inhibits the DSGCs. We review the biophysical mechanisms that produce directional GABA release from SBACs and test a network model that predicts the effects of reciprocal inhibition between adjacent SBACs. The results of the model simulations suggest that reciprocal inhibitory connections between closely spaced SBACs should be spatially selective, while connections between more widely spaced cells could be indiscriminate. SBACs were initially identified as cholinergic neurons and were subsequently shown to contain release both acetylcholine and GABA. While the role of the GABAergic transmission is well established, the role of the cholinergic transmission remains unclear. PMID:22310373

  16. 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.

  17. IMPROVEMENT OF EDUCATIONAL COGNITIVE ACTIVITY STUDENTS IN THE PROFESSIONAL EDUCATIONAL ORGANIZATION ON THE BASIS OF VISUALIZATION TECHNOLOGY OF EDUCATIONAL INFORMATION

    Directory of Open Access Journals (Sweden)

    Liliya A. Kolmakova

    2015-01-01

    Full Text Available The aim of the study is to consider the problem of improving the quality of education in the professional educational organizations.Methods. The scientific and pedagogical analyses of the concepts forming a terminological field of a problem are used. The system, competence-based and personal approaches are used for development of models of cognitive visualization. Questioning of students was carried out to establish the level of development of their informative activity.Results. The constituent parts of the modern educational process and the need to create specific conditions for its implementation are identified and described. The author gives a generalized characteristic of visualization technology of educational information. The application of cognitive visualization models using information and communication technologies are proved. The results showing the evolution of motivational indicators of students’ activity before and after application of LSM and the «Metaplan» in the educational process are presented.Scientific novelty. The pedagogical conditions that allow using information and communication technologies as means of the trainees’ educational informative activity improvement in the professional educational organization are defined. Features of the directed application of methods of cognitive visualization of educational information, both for improvement of educational cognitive activity, and for formation of professional competences of students by profession «A chef, a confectioner» are noted.Practical importance. Use of methods of cognitive visualization in educational process on the example of studying of Chemistry and Biology in the professional educational organization is considered in details. The teaching package providing application of methods of cognitive visualization of educational information for the purpose of improvement of educational cognitive activity of students in the professional educational organization

  18. [Endothelial origin for hematopoietic stem cells: a visual proof].

    Science.gov (United States)

    Boisset, Jean-Charles; Robin, Catherine

    2011-10-01

    Hematopoietic stem cells (HSC) are the source of all blood cell types produced during the entire life of an organism. They appear during embryonic development, where they will transit through different successive hematopoietic organs, before to finally colonize the bone marrow. Nowadays, the precise origin of HSC remains a matter of controversy. Different HSC precursor candidates, located in different anatomical sites, have been proposed. Here, we summarize and discuss the different theories in light of the recent articles, especially those using in vivo confocal microscopy technology.

  19. Improving UGV teleoperation performance using novel visualization techniques and manual interfaces

    Science.gov (United States)

    Vozar, Steven; Tilbury, Dawn M.

    2012-06-01

    Unmanned ground vehicles (UGVs) are well-suited to a variety of tasks that are dangerous or repetitive for humans to perform. Despite recent advances, UGVs still suffer from reliability issues, and human operation failures have been identified as one root cause of UGV system failure. However, most literature relevant to UGV reliability does not address the effects of human errors or the user interface. Our previous work investigated the issue of user situational awareness and sense of presence in the robot workspace by implementing a Mixed Reality interface featuring a first-person video feed with an Augmented Reality overlay and a third-person Virtual Reality display. The interface was evaluated in a series of user tests in which users manually controlled a UGV with a manipulator arm using traditional input modalities including a computer mouse, keyboard and gamepad. In this study, we learned that users found it challenging to mentally map commands from the manual inputs to the robot arm behavior. Also, switching between control modalities seemed to add to the cognitive load during teleoperation tasks. A master-slave style manual controller can provide an intuitive one-to-one mapping from user input to robot pose, and has the potential to improve both operator situational awareness for teleoperation tasks and decrease mission completion time. This paper describes the design and implementation of a teleoperated UGV with a Mixed Reality visualization interface and a master-slave controller that is suitable for teleoperated mobile manipulation tasks.

  20. An Efficient Adaptive Window Size Selection Method for Improving Spectrogram Visualization

    Directory of Open Access Journals (Sweden)

    Shibli Nisar

    2016-01-01

    Full Text Available Short Time Fourier Transform (STFT is an important technique for the time-frequency analysis of a time varying signal. The basic approach behind it involves the application of a Fast Fourier Transform (FFT to a signal multiplied with an appropriate window function with fixed resolution. The selection of an appropriate window size is difficult when no background information about the input signal is known. In this paper, a novel empirical model is proposed that adaptively adjusts the window size for a narrow band-signal using spectrum sensing technique. For wide-band signals, where a fixed time-frequency resolution is undesirable, the approach adapts the constant Q transform (CQT. Unlike the STFT, the CQT provides a varying time-frequency resolution. This results in a high spectral resolution at low frequencies and high temporal resolution at high frequencies. In this paper, a simple but effective switching framework is provided between both STFT and CQT. The proposed method also allows for the dynamic construction of a filter bank according to user-defined parameters. This helps in reducing redundant entries in the filter bank. Results obtained from the proposed method not only improve the spectrogram visualization but also reduce the computation cost and achieves 87.71% of the appropriate window length selection.

  1. Robot tracking system improvements and visual calibration of orbiter position for radiator inspection

    Science.gov (United States)

    Tonkay, Gregory

    1990-01-01

    The following separate topics are addressed: (1) improving a robotic tracking system; and (2) providing insights into orbiter position calibration for radiator inspection. The objective of the tracking system project was to provide the capability to track moving targets more accurately by adjusting parameters in the control system and implementing a predictive algorithm. A computer model was developed to emulate the tracking system. Using this model as a test bed, a self-tuning algorithm was developed to tune the system gains. The model yielded important findings concerning factors that affect the gains. The self-tuning algorithms will provide the concepts to write a program to automatically tune the gains in the real system. The section concerning orbiter position calibration provides a comparison to previous work that had been performed for plant growth. It provided the conceptualized routines required to visually determine the orbiter position and orientation. Furthermore, it identified the types of information which are required to flow between the robot controller and the vision system.

  2. 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.

  3. Visualizing how cancer chromosome abnormalities form in living cells

    Science.gov (United States)

    For the first time, scientists have directly observed events that lead to the formation of a chromosome abnormality that is often found in cancer cells. The abnormality, called a translocation, occurs when part of a chromosome breaks off and becomes attac

  4. 3D visualization of membrane failures in fuel cells

    Science.gov (United States)

    Singh, Yadvinder; Orfino, Francesco P.; Dutta, Monica; Kjeang, Erik

    2017-03-01

    Durability issues in fuel cells, due to chemical and mechanical degradation, are potential impediments in their commercialization. Hydrogen leak development across degraded fuel cell membranes is deemed a lifetime-limiting failure mode and potential safety issue that requires thorough characterization for devising effective mitigation strategies. The scope and depth of failure analysis has, however, been limited by the 2D nature of conventional imaging. In the present work, X-ray computed tomography is introduced as a novel, non-destructive technique for 3D failure analysis. Its capability to acquire true 3D images of membrane damage is demonstrated for the very first time. This approach has enabled unique and in-depth analysis resulting in novel findings regarding the membrane degradation mechanism; these are: significant, exclusive membrane fracture development independent of catalyst layers, localized thinning at crack sites, and demonstration of the critical impact of cracks on fuel cell durability. Evidence of crack initiation within the membrane is demonstrated, and a possible new failure mode different from typical mechanical crack development is identified. X-ray computed tomography is hereby established as a breakthrough approach for comprehensive 3D characterization and reliable failure analysis of fuel cell membranes, and could readily be extended to electrolyzers and flow batteries having similar structure.

  5. Stem Cell Ophthalmology Treatment Study (SCOTS):improvement in serpiginous choroidopathy following autologous bone marrow derived stem cell treatment

    Institute of Scientific and Technical Information of China (English)

    Jeffrey N Weiss; Susan C Benes; Steven Levy

    2016-01-01

    We report results in a 77-year-old male patient with visual loss from long-standing serpiginous choroidop-athy treated with bone marrow derived stem cells (BMSC) within the Stem Cell Ophthalmology Treatment Study (SCOTS). SCOTS is an Institutional Review Board approved clinical trial and the largest ophthal-mology stem cell study registered at the National Institutes of Health to date (ClinicalTrials.gov Identiifer:NCT01920867). Eight months after treatment by a combination of retrobulbar, subtenon, intravitreal and intravenous injection of BMSC, the patient’s best corrected Snellen acuity improved from 20/80– to 20/60+1 in the right eye and from 20/50– to 20/20–3 in the left eye. The Early Treatment of Diabetic Retinopathy Study (ETDRS) visual acuity continued to improve over the succeeding 8 months and the optical coherence tomography macular volume increased. The increases in visual acuity and macular volume are encouraging and suggest that the use of BMSC as provided in SCOTS may be a viable approach to treating serpiginous choroidopathy.

  6. Dense codes at high speeds: varying stimulus properties to improve visual speller performance

    NARCIS (Netherlands)

    Geuze, J.; Farquhar, J.D.R.; Desain, P.W.M.

    2012-01-01

    This paper investigates the effect of varying different stimulus properties on performance of the visual speller. Each of the different stimulus properties has been tested in previous literature and has a known effect on visual speller performance. This paper investigates whether a combination of th

  7. 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…

  8. Noise-improved signal detection in cat primary visual cortex via a well-balanced stochastic resonance-like procedure.

    Science.gov (United States)

    Funke, Klaus; Kerscher, Nicolas J; Wörgötter, Florentin

    2007-09-01

    Adding noise to a weak signal can paradoxically improve signal detection, a process called 'stochastic resonance' (SR). In the visual system, noise might be introduced by the image jitter resulting from high-frequency eye movements, like eye microtremor and microsaccades. To test whether this kind of noise might be beneficial or detrimental for cortical signal detection, we performed single-unit recordings from area 17 of anaesthetized cats while jittering the visual stimulus in a frequency and amplitude range resembling the possible range of eye movements. We used weak, sub- and peri-threshold visual stimuli, on top of which we superimposed noise with variable jitter amplitude. In accordance with the typical SR effect, we found that small noise levels actually increased the signal-to-noise ratio (SNR) of previously weak cortical visual responses, while originally strong responses were little affected or even reduced. Above a certain noise level, the SNR dropped a little, but not as a result of increased background activity - as would be proposed by SR theory - but because of a lowered response to signal and noise. Therefore, it seems that the ascending visual pathway optimally utilizes signal detection improvement by a SR-like process, while at the same time preventing spurious noise-induced activity and keeping the SNR sufficiently high.

  9. CDy6, a photostable probe for long-term real-time visualization of mitosis and proliferating cells.

    Science.gov (United States)

    Jeong, Yun-Mi; Duanting, Zhai; Hennig, Holger; Samanta, Animesh; Agrawalla, Bikram Keshari; Bray, Mark-Anthony; Carpenter, Anne E; Chang, Young-Tae

    2015-02-19

    Long-term real-time visualization of lysosomal dynamics has been challenging at the onset of mitosis due to the lack of fluorescent probes enabling convenient imaging of dividing cells. We developed a long-term real-time photostable mitotic or proliferating marker, CDy6, a BODIPY-derived compound of designation yellow 6, which labels lysosome. In long-term real-time, CDy6 displayed a sharp increase in intensity and change in localization in mitosis, improved photostability, and decreased toxicity compared with other widely used lysosomal and DNA markers, and the ability to label cells in mouse xenograft models. Therefore, CDy6 may open new possibilities to target and trace lysosomal contents during mitosis and to monitor cell proliferation, which can further our knowledge of the basic underlying biological mechanisms in the management of cancer.

  10. Receptive Field Vectors of Genetically-Identified Retinal Ganglion Cells Reveal Cell-Type-Dependent Visual Functions.

    Directory of Open Access Journals (Sweden)

    Matthew L Katz

    Full Text Available Sensory stimuli are encoded by diverse kinds of neurons but the identities of the recorded neurons that are studied are often unknown. We explored in detail the firing patterns of eight previously defined genetically-identified retinal ganglion cell (RGC types from a single transgenic mouse line. We first introduce a new technique of deriving receptive field vectors (RFVs which utilises a modified form of mutual information ("Quadratic Mutual Information". We analysed the firing patterns of RGCs during presentation of short duration (~10 second complex visual scenes (natural movies. We probed the high dimensional space formed by the visual input for a much smaller dimensional subspace of RFVs that give the most information about the response of each cell. The new technique is very efficient and fast and the derivation of novel types of RFVs formed by the natural scene visual input was possible even with limited numbers of spikes per cell. This approach enabled us to estimate the 'visual memory' of each cell type and the corresponding receptive field area by calculating Mutual Information as a function of the number of frames and radius. Finally, we made predictions of biologically relevant functions based on the RFVs of each cell type. RGC class analysis was complemented with results for the cells' response to simple visual input in the form of black and white spot stimulation, and their classification on several key physiological metrics. Thus RFVs lead to predictions of biological roles based on limited data and facilitate analysis of sensory-evoked spiking data from defined cell types.

  11. Representation of the visual field in the primary visual area of the marmoset monkey: magnification factors, point-image size, and proportionality to retinal ganglion cell density.

    Science.gov (United States)

    Chaplin, Tristan A; Yu, Hsin-Hao; Rosa, Marcello G P

    2013-04-01

    The primary visual area (V1) forms a systematic map of the visual field, in which adjacent cell clusters represent adjacent points of visual space. A precise quantification of this map is key to understanding the anatomical relationships between neurons located in different stations of the visual pathway, as well as the neural bases of visual performance in different regions of the visual field. We used computational methods to quantify the visual topography of V1 in the marmoset (Callithrix jacchus), a small diurnal monkey. The receptive fields of neurons throughout V1 were mapped in two anesthetized animals using electrophysiological recordings. Following histological reconstruction, precise 3D reconstructions of the V1 surface and recording sites were generated. We found that the areal magnification factor (M(A) ) decreases with eccentricity following a function that has the same slope as that observed in larger diurnal primates, including macaque, squirrel, and capuchin monkeys, and humans. However, there was no systematic relationship between M(A) and polar angle. Despite individual variation in the shape of V1, the relationship between M(A) and eccentricity was preserved across cases. Comparison between V1 and the retinal ganglion cell density demonstrated preferential magnification of central space in the cortex. The size of the cortical compartment activated by a punctiform stimulus decreased from the foveal representation towards the peripheral representation. Nonetheless, the relationship between the receptive field sizes of V1 cells and the density of ganglion cells suggested that each V1 cell receives information from a similar number of retinal neurons, throughout the visual field.

  12. Subjective evaluation of two stereoscopic imaging systems exploiting visual attention to improve 3D quality of experience

    Science.gov (United States)

    Hanhart, Philippe; Ebrahimi, Touradj

    2014-03-01

    Crosstalk and vergence-accommodation rivalry negatively impact the quality of experience (QoE) provided by stereoscopic displays. However, exploiting visual attention and adapting the 3D rendering process on the fly can reduce these drawbacks. In this paper, we propose and evaluate two different approaches that exploit visual attention to improve 3D QoE on stereoscopic displays: an offline system, which uses a saliency map to predict gaze position, and an online system, which uses a remote eye tracking system to measure real time gaze positions. The gaze points were used in conjunction with the disparity map to extract the disparity of the object-of-interest. Horizontal image translation was performed to bring the fixated object on the screen plane. The user preference between standard 3D mode and the two proposed systems was evaluated through a subjective evaluation. Results show that exploiting visual attention significantly improves image quality and visual comfort, with a slight advantage for real time gaze determination. Depth quality is also improved, but the difference is not significant.

  13. 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.

  14. 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...

  15. 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.

  16. 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

  17. Visualization and 3D reconstruction of flame cells of Taenia solium (cestoda.

    Directory of Open Access Journals (Sweden)

    Laura E Valverde-Islas

    Full Text Available BACKGROUND: Flame cells are the terminal cells of protonephridial systems, which are part of the excretory systems of invertebrates. Although the knowledge of their biological role is incomplete, there is a consensus that these cells perform excretion/secretion activities. It has been suggested that the flame cells participate in the maintenance of the osmotic environment that the cestodes require to live inside their hosts. In live Platyhelminthes, by light microscopy, the cells appear beating their flames rapidly and, at the ultrastructural, the cells have a large body enclosing a tuft of cilia. Few studies have been performed to define the localization of the cytoskeletal proteins of these cells, and it is unclear how these proteins are involved in cell function. METHODOLOGY/PRINCIPAL FINDINGS: Parasites of two different developmental stages of T. solium were used: cysticerci recovered from naturally infected pigs and intestinal adults obtained from immunosuppressed and experimentally infected golden hamsters. Hamsters were fed viable cysticerci to recover adult parasites after one month of infection. In the present studies focusing on flame cells of cysticerci tissues was performed. Using several methods such as video, confocal and electron microscopy, in addition to computational analysis for reconstruction and modeling, we have provided a 3D visual rendition of the cytoskeletal architecture of Taenia solium flame cells. CONCLUSIONS/SIGNIFICANCE: We consider that visual representations of cells open a new way for understanding the role of these cells in the excretory systems of Platyhelminths. After reconstruction, the observation of high resolution 3D images allowed for virtual observation of the interior composition of cells. A combination of microscopic images, computational reconstructions and 3D modeling of cells appears to be useful for inferring the cellular dynamics of the flame cell cytoskeleton.

  18. 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

  19. Visualizing tropoelastin in a long-term human elastic fibre cell culture model.

    Science.gov (United States)

    Halm, M; Schenke-Layland, K; Jaspers, S; Wenck, H; Fischer, F

    2016-02-04

    Elastin is an essential protein found in a variety of tissues where resilience and flexibility are needed, such as the skin and the heart. When aiming to engineer suitable implants, elastic fibres are needed to allow adequate tissue renewal. However, the visualization of human elastogenesis remains in the dark. To date, the visualization of human tropoelastin (TE) production in a human cell context and its fibre assembly under live cell conditions has not been achieved. Here, we present a long-term cell culture model of human dermal fibroblasts expressing fluorescence-labelled human TE. We employed a lentiviral system to stably overexpress Citrine-labelled TE to build a fluorescent fibre network. Using immunofluorescence, we confirmed the functionality of the Citrine-tagged TE. Furthermore, we visualized the fibre assembly over the course of several days using confocal microscopy. Applying super resolution microscopy, we were able to investigate the inner structure of the elastin-fibrillin-1 fibre network. Future investigations will allow the tracking of TE produced under various conditions. In tissue engineering applications the fluorescent fibre network can be visualized under various conditions or it serves as a tool for investigating fibre degradation processes in disease-in-a-dish-models.

  20. Visualizing tropoelastin in a long-term human elastic fibre cell culture model

    Science.gov (United States)

    Halm, M.; Schenke-Layland, K.; Jaspers, S.; Wenck, H.; Fischer, F.

    2016-01-01

    Elastin is an essential protein found in a variety of tissues where resilience and flexibility are needed, such as the skin and the heart. When aiming to engineer suitable implants, elastic fibres are needed to allow adequate tissue renewal. However, the visualization of human elastogenesis remains in the dark. To date, the visualization of human tropoelastin (TE) production in a human cell context and its fibre assembly under live cell conditions has not been achieved. Here, we present a long-term cell culture model of human dermal fibroblasts expressing fluorescence-labelled human TE. We employed a lentiviral system to stably overexpress Citrine-labelled TE to build a fluorescent fibre network. Using immunofluorescence, we confirmed the functionality of the Citrine-tagged TE. Furthermore, we visualized the fibre assembly over the course of several days using confocal microscopy. Applying super resolution microscopy, we were able to investigate the inner structure of the elastin–fibrillin-1 fibre network. Future investigations will allow the tracking of TE produced under various conditions. In tissue engineering applications the fluorescent fibre network can be visualized under various conditions or it serves as a tool for investigating fibre degradation processes in disease-in-a-dish-models. PMID:26842906

  1. Globally visualizing the microtubule-dependent transport behaviors of influenza virus in live cells.

    Science.gov (United States)

    Liu, Shu-Lin; Zhang, Li-Juan; Wang, Zhi-Gang; Zhang, Zhi-Ling; Wu, Qiu-Mei; Sun, En-Ze; Shi, Yun-Bo; Pang, Dai-Wen

    2014-04-15

    Understanding the microtubule-dependent behaviors of viruses in live cells is very meaningful for revealing the mechanisms of virus infection and endocytosis. Herein, we used a quantum dots-based single-particle tracking technique to dynamically and globally visualize the microtubule-dependent transport behaviors of influenza virus in live cells. We found that the intersection configuration of microtubules can interfere with the transport behaviors of the virus in live cells, which lead to the changing and long-time pausing of the transport behavior of viruses. Our results revealed that most of the viruses moved along straight microtubules rapidly and unidirectionally from the cell periphery to the microtubule organizing center (MTOC) near the bottom of the cell, and the viruses were confined in the grid of microtubules near the top of the cell and at the MTOC near the bottom of the cell. These results provided deep insights into the influence of entire microtubule geometry on the virus infection.

  2. Real-time visualization of nanoparticles interacting with glioblastoma stem cells.

    Science.gov (United States)

    Pohlmann, Elliot S; Patel, Kaya; Guo, Sujuan; Dukes, Madeline J; Sheng, Zhi; Kelly, Deborah F

    2015-04-08

    Nanoparticle-based therapy represents a novel and promising approach to treat glioblastoma, the most common and lethal malignant brain cancer. Although similar therapies have achieved significant cytotoxicity in cultured glioblastoma or glioblastoma stem cells (GSCs), the lack of an appropriate approach to monitor interactions between cells and nanoparticle-based therapies impedes their further clinical application in human patients. To address this critical issue, we first obtained NOTCH1 positive GSCs from patient-derived primary cultures. We then developed a new imaging approach to directly observe the dynamic nature of nanoparticles at the molecular level using in situ transmission electron microscopy (TEM). Utilizing these tools we were able to visualize real-time movements of nanoparticles interacting with GSCs for the first time. Overall, we show strong proof-of-concept results that real-time visualization of nanoparticles in single cells can be achieved at the nanoscale using TEM, thereby providing a powerful platform for the development of nanotherapeutics.

  3. Improve T Cell Therapy in Neuroblastoma

    Science.gov (United States)

    2012-07-01

    Acquisition of full effector function in vitro paradoxically impairs the in vivo antitumor efficacy of adoptively transferred CD8+ T cells. J.Clin.Invest...function in vitro paradoxically impairs the in vivo antitumor efficacy of adoptively transferred CD8+ T cells. J. Clin. Invest. 115: 1616–1626. 14. Hinrichs...cells in non- obese diabetic/Shi-scid, IL-2 receptor gamma null mice. J Immunol. 2002;169(1):204–209. 27. Giassi LJ, et al. Expanded CD34+ human

  4. 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...

  5. Cell surgery and growth factors in dry age-related macular degeneration: visual prognosis and morphological study

    Science.gov (United States)

    Limoli, Paolo Giuseppe; Limoli, Celeste; Vingolo, Enzo Maria; Scalinci, Sergio Zaccaria; Nebbioso, Marcella

    2016-01-01

    Background The aim of this research was to study the overall restoration effect on residual retinal cells through surgically grafted autologous cells onto the surrounding tissue, choroid and retina in order to produce a constant secretion of growth factors (GFs) in dry age-related macular degeneration (AMD) patients. Results 6 months after surgery, several values were statistically significant in the group with higher RTA. Also patient compliance analysis (PCA) in relation to functional change perception appeared to be very good. Methods Thirty-six eyes of 25 patients (range 64-84 years of age) affected by dry AMD were included in study, and divided in two groups by spectral domain-optical coherence tomography (SD-OCT): group A with retinal thickness average (RTA) less than 250 microns (μm) and group B with RTA equal to or more than 250 μm. Adipocytes, adipose-derived stem cells from the stromal-vascular fraction, and platelets from platelet-rich plasma were implanted in the suprachoroidal space. Particularly, the following parameters were evaluated: best corrected visual acuity (BCVA) for far and near distance, retinal thickness maps, scotopic and photopic electroretinogram (ERG), and microperimetry (MY). All statistical analyses were performed with STATA 14.0 (Collage Station, Texas, USA). Conclusions The available set of GFs allowed biological retinal neuroenhancement. After 6 months it improved visual performance (VP), but the increase was better if RTA recorded by OCT was higher, probably in relation to the presence of areas with greater cellularity. PMID:27391437

  6. 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.

  7. 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

    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 cell walls of Arabidopsis root epidermal cells with confocal microscopy. The resolution limit of confocal...... as alternatives 3D-structured illumination microscopy (3D-SIM) and confocal microscopy, combined with image deconvolution. Both methods offer lower resolution than STORM, but enable 3D imaging. While 3D-SIM produced strong artifacts, deconvolution gave good results. The resolution was improved over conventional...... 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...

  8. 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.

  9. An improved method for the visualization of conductive vessels in Arabidopsis thaliana inflorescence stems

    Directory of Open Access Journals (Sweden)

    Radek eJupa

    2015-04-01

    Full Text Available Dye perfusion is commonly used for the identification of conductive elements important for the study of xylem development as well as precise hydraulic estimations. The tiny size of inflorescence stems, the small amount of vessels in close arrangement, and high hydraulic resistivity delimit the use of the method for quantification of the water conductivity of Arabidopsis thaliana, one of the recently most extensively used plant models. Here, we present an extensive adjustment to the method in order to reliably identify individual functional (conductive vessels. Segments of inflorescence stems were sealed in silicone tubes to prevent damage and perfused with a dye solution. Our results showed that dyes often used for staining functional xylem elements (safranin, fuchsine, toluidine blue failed with Arabidopsis. In contrast, Fluorescent Brightener 28 dye solution perfused through segments stained secondary cell walls of functional vessels, which were clearly distinguishable in native cross sections. When compared to identification based on the degree of development of secondary cell walls, identification with the help of dye perfusion revealed a significantly lower number of functional vessels and values of theoretical hydraulic conductivity. We found that lignified but not yet functional vessels form a substantial portion of the xylem in apical and basal segments of Arabidopsis and, thus, significantly affect the analyzed functional parameters of xylem. The presented methodology enables reliable identification of individual functional vessels, allowing thus estimations of hydraulic conductivities to be improved, size distributions and vessel diameters to be refined, and data variability generally to be reduced.

  10. 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.

  11. Visualizing spatiotemporal dynamics of multicellular cell-cycle progressions with fucci technology.

    Science.gov (United States)

    Sakaue-Sawano, Asako; Miyawaki, Atsushi

    2014-05-01

    The visualization of cell-cycle behavior of individual cells within complex tissues presents an irresistible challenge to biologists studying multicellular structures. However, the transition from G1 to S in the cell cycle is difficult to monitor despite the fact that the process involves the critical decision to initiate a new round of DNA replication. Here, we use ubiquitination oscillators that control cell-cycle transitions to develop genetically encoded fluorescent probes for cell-cycle progression. Fucci (fluorescent ubiquitination-based cell-cycle indicator) probes exploit the regulation of cell-cycle-dependent ubiquitination to effectively label individual nuclei in G1 phase red, and those in S/G2/M phases green. Cultured cells and transgenic mice constitutively expressing the probes have been generated, such that every cell nucleus shows either red or green fluorescence. This protocol details two experiments that use biological samples expressing Fucci probes. One experiment involves time-lapse imaging of cells stably expressing a Fucci derivative (Fucci2), which allows for the exploration of the spatiotemporal patterns of cell-cycle dynamics during structural and behavioral changes of cultured cells. The other experiment involves large-field, high-resolution imaging of fixed sections of Fucci transgenic mouse embryos, which provides maps that illustrate cell proliferation versus differentiation in various developing organs.

  12. 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...

  13. Comment on 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)

    Ahmet; Tas; Abdullah; Ilhan; Umit; Yolcu; Uzeyir; Erdem

    2015-01-01

    <正>Dear Editor,We congratulate Zeng et al[1]for their study entitled"Amniotic membrane covering promotes healing of cornea epithelium and improves visual acuity after debridement for fungal keratitis".The authors endeavored to present an alternative method for ophthalmologists in the treatment of a challenging case.We would like to express our reservations and ask for the attitudes of the authors about

  14. Method of constructing an improved electrochemical cell

    Science.gov (United States)

    Grimes, Patrick G.; Einstein, Harry

    1984-10-09

    An electrochemical cell construction features a novel co-extruded plastic electrode in an interleaved construction with a novel integral separator-spacer. Also featured is a leak and impact resistant construction for preventing the spill of corrosive materials in the event of rupture.

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

    Science.gov (United States)

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

    1984-03-01

    /he 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 (14)--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 (19). 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. In cats with intact labyrinths, D2O changed the optimal length of the light bar that was able to stimulate the cortical cell as well as the path on which it evoked the response of the cell. Both values, which constitute the receptive field of the cell, changed approximately proportionately. This effect usually lasts for less than 4.5 h. 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 (and the other cellular characteristics studied) did not change following D2O administration. In nonvisual cells from labyrinth-intact cats, the spontaneous activity demonstrated a slight but significant decrease

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Traditional Project Management and the Visual Workplace Environment to Improve Project Success

    Science.gov (United States)

    Fichera, Christopher E.

    2016-01-01

    A majority of large IT projects fail to meet scheduled deadlines, are over budget and do not satisfy the end user. Many projects fail in spite of utilizing traditional project management techniques. Research of project management has not identified the use of a visual workspace as a feature affecting or influencing the success of a project during…

  1. Pip and pop : Non-spatial auditory signals improve spatial visual search

    NARCIS (Netherlands)

    Burg, E. van der; Olivers, C.N.L.; Bronkhorst, A.W.; Theeuwes, J.

    2008-01-01

    Searching for an object within a cluttered, continuously changing environment can be a very time-consuming process. The authors show that a simple auditory pip drastically decreases search times for a synchronized visual object that is normally very difficult to find. This effect occurs even though

  2. Enhanced Visual-Attention Model for Perceptually Improved 3D Object Modeling in Virtual Environments

    Science.gov (United States)

    Chagnon-Forget, Maude; Rouhafzay, Ghazal; Cretu, Ana-Maria; Bouchard, Stéphane

    2016-12-01

    Three-dimensional object modeling and interactive virtual environment applications require accurate, but compact object models that ensure real-time rendering capabilities. In this context, the paper proposes a 3D modeling framework employing visual attention characteristics in order to obtain compact models that are more adapted to human visual capabilities. An enhanced computational visual attention model with additional saliency channels, such as curvature, symmetry, contrast and entropy, is initially employed to detect points of interest over the surface of a 3D object. The impact of the use of these supplementary channels is experimentally evaluated. The regions identified as salient by the visual attention model are preserved in a selectively-simplified model obtained using an adapted version of the QSlim algorithm. The resulting model is characterized by a higher density of points in the salient regions, therefore ensuring a higher perceived quality, while at the same time ensuring a less complex and more compact representation for the object. The quality of the resulting models is compared with the performance of other interest point detectors incorporated in a similar manner in the simplification algorithm. The proposed solution results overall in higher quality models, especially at lower resolutions. As an example of application, the selectively-densified models are included in a continuous multiple level of detail (LOD) modeling framework, in which an original neural-network solution selects the appropriate size and resolution of an object.

  3. 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...... it was incompatible. These results suggest that proprioception influences the allocation of attention in visual space....

  4. 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

    , without visual feedback, in the other week. In the heating season, two pairs of classrooms were monitored, one pair naturally and the other pair mechanically ventilated. In the cooling season, two pairs of naturally ventilated classrooms were monitored, one pair with split cooling in operation...

  5. Web-Based Interactive 3D Visualization as a Tool for Improved Anatomy Learning

    Science.gov (United States)

    Petersson, Helge; Sinkvist, David; Wang, Chunliang; Smedby, Orjan

    2009-01-01

    Despite a long tradition, conventional anatomy education based on dissection is declining. This study tested a new virtual reality (VR) technique for anatomy learning based on virtual contrast injection. The aim was to assess whether students value this new three-dimensional (3D) visualization method as a learning tool and what value they gain…

  6. Can walking motions improve visually induced rotational self-motion illusions in virtual reality?

    Science.gov (United States)

    Riecke, Bernhard E; Freiberg, Jacob B; Grechkin, Timofey Y

    2015-02-04

    Illusions of self-motion (vection) can provide compelling sensations of moving through virtual environments without the need for complex motion simulators or large tracked physical walking spaces. Here we explore the interaction between biomechanical cues (stepping along a rotating circular treadmill) and visual cues (viewing simulated self-rotation) for providing stationary users a compelling sensation of rotational self-motion (circular vection). When tested individually, biomechanical and visual cues were similarly effective in eliciting self-motion illusions. However, in combination they yielded significantly more intense self-motion illusions. These findings provide the first compelling evidence that walking motions can be used to significantly enhance visually induced rotational self-motion perception in virtual environments (and vice versa) without having to provide for physical self-motion or motion platforms. This is noteworthy, as linear treadmills have been found to actually impair visually induced translational self-motion perception (Ash, Palmisano, Apthorp, & Allison, 2013). Given the predominant focus on linear walking interfaces for virtual-reality locomotion, our findings suggest that investigating circular and curvilinear walking interfaces offers a promising direction for future research and development and can help to enhance self-motion illusions, presence and immersion in virtual-reality systems.

  7. Improving visual assessment documentation in patients with periorbital trauma through an eye assessment teaching session and a proforma sticker

    Science.gov (United States)

    Myuran, Tharsika

    2017-01-01

    Up to 30% of patients who have periorbital trauma will have ocular injury with devastating consequences if missed. All staff working with acutely injured Oral and Maxillofacial Surgery (OMFS) patients should be competent in a basic eye examination with documentation of visual acuity, gross visual fields, eye movements, diplopia, and pupillary responses at a minimum. As a standard we adapted guidance published by the Emergency Care Institute New South Wales to assess the documentation of the eye examination in OMFS patients at King's College Hospital with any periorbital injury. After initial assessment we presented the data in the departmental audit meeting, then gave a detailed teaching session to junior doctors and introduced an ‘eye exam’ proforma sticker designed to act as an aide memoir. At baseline, 38 eye assessments across all clinical environments and by all seniority of clinician were assessed at random. Of these, 41% of these had visual acuity documented, 5% visual fields, 47% pupils, and 83% movements. After presentation of data, reaudit showed progress to 81%, 0%, 94%, and 100% respectively. Following the teaching session reaudit showed final progression to 83%, 46%, 83%, and 100%. Teaching sessions and use of an eye sticker proforma has been shown to improve rates of documentation of the eye exam for those OMFS patients presenting with periorbital injuries.

  8. An improved self-calibration approach based on adaptive genetic algorithm for position-based visual servo

    Institute of Scientific and Technical Information of China (English)

    Ding LIU; Xiongjun WU; Yanxi YANG

    2008-01-01

    An improved self-calibrating algorithm for visual servo based on adaptive genetic algorithm is proposed in this paper.Our approach introduces an extension of Mendonca-Cipolla and G.Chesi's self-calibration for the positionbased visual servo technique which exploits the singular value property of the essential matrix.Specifically,a suitable dynamic online cost function is generated according to the property of the three singular values.The visual servo process is carried out simultaneous to the dynamic self-calibration,and then the cost function is minirmzed using the adaptive genetic algorithm instead of the gradient descent method in G.Chesi's approach.Moreover,this method overcomes the limitation that the initial parameters must be selected close to the true value,which is not constant in many cases.It is not necessary to know exactly the camera intrinsic parameters when using our approach,instead,coarse coding bounds ot the five parameters are enough for the algorithm,which can be done once and for all off-line.Besides,this algorithm does not require knowledge of the 3D model of the object.Simulation experiments are carried out and the results demonstrate that the proposed approach provides a fast convergence speed and robustness against unpredictable perturbalaons of camera parameters,and it is an effective and efficient visual scrvo algorithm.

  9. Using visual cues of contact to improve interactive manipulation of virtual objects in industrial assembly/maintenance simulations.

    Science.gov (United States)

    Sreng, Jean; Lécuyer, Anatole; Mégard, Christine; Andriot, Claude

    2006-01-01

    This paper describes a set of visual cues of contact designed to improve the interactive manipulation of virtual objects in industrial assembly/maintenance simulations. These visual cues display information of proximity, contact and effort between virtual objects when the user manipulates a part inside a digital mock-up. The set of visual cues encloses the apparition of glyphs (arrow, disk, or sphere) when the manipulated object is close or in contact with another part of the virtual environment. Light sources can also be added at the level of contact points. A filtering technique is proposed to decrease the number of glyphs displayed at the same time. Various effects--such as change in color, change in size, and deformation of shape- can be applied to the glyphs as a function of proximity with other objects or amplitude of the contact forces. A preliminary evaluation was conducted to gather the subjective preference of a group of participants during the simulation of an automotive assembly operation. The collected questionnaires showed that participants globally appreciated our visual cues of contact. The changes in color appeared to be preferred concerning the display of distances and proximity information. Size changes and deformation effects appeared to be preferred in terms of perception of contact forces between the parts. Last, light sources were selected to focus the attention of the user on the contact areas.

  10. In situ visualization of intracellular morphology of epidermal cells using stimulated Raman scattering microscopy

    Science.gov (United States)

    Egawa, Mariko; Tokunaga, Kyoya; Hosoi, Junichi; Iwanaga, Shinya; Ozeki, Yasuyuki

    2016-08-01

    Visualization of epidermal cells is important because the differentiation patterns of keratinocytes (KCs) are considered to be related to the functions and condition of skin. Optical microscopy has been widely used to investigate epidermal cells, but its applicability is still limited because of the need for sample fixation and staining. Here, we report our staining-free observation of epidermal cells in both tissue and culture by stimulated Raman scattering (SRS) microscopy that provides molecular vibrational contrast. SRS allowed us to observe a variety of cellular morphologies in skin tissue, including ladder-like structures in the spinous layer, enucleation of KCs in the granular layer, and three-dimensional cell column structures in the stratum corneum. We noticed that some cells in the spinous layer had a brighter signal in the cytoplasm than KCs. To examine the relevance of the observation of epidermal layers, we also observed cultured epidermal cells, including KCs at various differentiation stages, melanocytes, and Langerhans cell-like cells. Their SRS images also demonstrated various morphologies, suggesting that the morphological differences observed in tissue corresponded to the cell lineage. These results indicate the possible application of SRS microscopy to dermatological investigation of cell lineages and types in the epidermis by cellular-level analysis.

  11. 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...

  12. 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.

  13. Two Sudden Onsets Capture Attention but Do Not Improve Visual Short-Term Memory

    Directory of Open Access Journals (Sweden)

    Huang Chi-Hsiang

    2011-05-01

    Full Text Available Onset stimulus can capture attention and then transfer into visual short-term memory. It remains unknown whether two sudden onsets also capture attention and are stored in vSTM. We modified Belopolsky, Kramer, and Godijn's (2008 visual search paradigm to test this issue. Experiment 1 using one onset and replicated Belopolsky et al's results. Two onsets in Experiment 2 were found to capture attention; however, recognition performance for the onsets was only at chance level, showing poor memory. Experiment 3 used a retro-cue to test whether only one of these two onsets can be stored in vSTM. Experiment 4 tested whehter this poor recognition was caused by interference from meory probe. This study has important insights on how attention interacts with memory.

  14. Improving object segmentation by using EEG signals and rapid serial visual presentation

    OpenAIRE

    Mohedano, Eva; Healy, Graham; McGuinness, Kevin; Giró Nieto, Xavier; O'Connor, Noel; Smeaton, Alan F.

    2015-01-01

    This paper extends our previous work on the potential of EEG-based brain computer interfaces to segment salient objects in images. The proposed system analyzes the Event Related Potentials (ERP) generated by the rapid serial visual presentation of windows on the image. The detection of the P300 signal allows estimating a saliency map of the image, which is used to seed a semi-supervised object segmentation algorithm. Thanks to the new contributions presented in this work, the average Jaccard ...

  15. 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...... as 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 results presented show the simplicity of using 3D city models as a physical data input in air quality modelling and the 3D air quality will improve insight for visual impact analysis (i.e. analysing the immersion of are circulation zone). The results are advantageous for city planners, architects...

  16. A Technique of Improved Medial Meniscus Visualization by Anterior Cruciate Ligament Graft Placement in Chronic Anterior Cruciate Deficient Knees.

    Science.gov (United States)

    Vertullo, Christopher J; Wijenayake, Lahann; Grayson, Jane E

    2016-04-01

    It is customary to perform medial meniscus repair before anterior cruciate ligament (ACL) graft placement when undertaken as a combined procedure. However, in chronic ACL-deficient knees, intraoperative anterior tibiofemoral translation can cause the medial meniscus repair to be more technically challenging. Intraoperative anterior tibiofemoral translation can both reduce the visualization of the medial meniscus and make its reduction unstable. An operative sequence alteration of ACL graft placement and tensioning before medial meniscal repair improves medial meniscus visualization in chronically ACL-deficient knees by using the ACL graft's ability to prevent anterior tibiofemoral translation. The technique sequence is as follows: (a) the medial meniscus is reduced, (b) ACL reconstruction is undertaken using a hamstring graft without final tibia fixation,

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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

    visualization of this 2D-expression pattern can be created by developing a 3D-model of the culture, based on serial paraffin sections. Individual sections are stained using individual markers. Using 3D image processing software such as Mimics or 3D-Doctor, the actual 3D-rendering of an entire colony can...... be 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...

  2. 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, a...... 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....

  3. [Understanding of immune system by visualization of spatiotemporal regulation of immune cells in the entire body].

    Science.gov (United States)

    Tomura, Michio

    2013-01-01

    Immune system is high-dimensional integrated system distributed in the whole body. Many kinds of, total 10(11) of immune cells are regulated by receiving appropriate signals in appropriate places. We have been attempting to understand immune system by revealing spatiotemporal regulation of immune cells at the whole body level by "Visualization of immune response in vivo". Photoconvertible protein, "Kaede"-Tg mice allowed us to monitor cell-replacement and cell-movement in the whole body by marking cells with color of Kaede from green to red with exposure to violet light. It is applicable to small cell number populations in both lymphoid organs and also peripheral tissues under both normal and pathophysiological conditions. By using this system, we have demonstrated novel findings that "Naive CD4(+) T cell recirculation is an active process that they recirculate through lymphoid organs to seek limited niche for interacting with endogenous antigens and upregulate their function." and "Activated regulatory T cells emigrating from cutaneous immune response is responsible for termination of immune reponse." I will introduce these new tools of us and would like to discuss what is needed to understand immune system in the entire body.

  4. Improvement of human dendritic cell culture for immunotoxicological investigations.

    Science.gov (United States)

    Hymery, N; Sibiril, Y; Parent-Massin, D

    2006-07-01

    A toxic injury such as a decrease in the number of immature dendritic cells caused by a cytotoxic effect or a disturbance in their maturation process can be responsible for immunodepression. There is a need to improve in vitro assays on human dendritic cells used to detect and evaluate adverse effects of xenobiotics. Two aspects were explored in this work: cytotoxic effects of xenobiotics on immature dendritic cells, and the interference of xenobiotics with dendritic cell maturation. Dendritic cells of two different origins were tested. Dendritic cells obtained either from umbilical cord blood CD34(+) cells or, for the first time, from umbilical cord blood monocytes. The cytotoxicity assay on immature dendritic cells has been improved. For the study of the potential adverse effects of xenobiotics on the maturation process of dendritic cells, several parameters were selected such as expression of markers (CD86, CD83, HLA-DR), secretion of interleukins 10 and 12, and proliferation of autologous lymphocytes. The relevance and the efficiency of the protocol applied were tested using two mycotoxins, T-2 toxin and deoxynivalence, DON, which are known to be immunosuppressive, and one phycotoxin, domoic acid, which is known not to have any immunotoxic effect. Assays using umbilical cord monocyte dendritic cell cultures with the protocol defined in this work, which involves a cytotoxicity study followed by evaluation of several markers of adverse effects on the dendritic cell maturation process, revealed their usefulness for investigating xenobiotic immunotoxicity toward immune primary reactions.

  5. 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.

  6. 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.

  7. 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.

  8. Strategies to improve homing of mesenchymal stem cells for greater efficacy in stem cell therapy.

    Science.gov (United States)

    Naderi-Meshkin, Hojjat; Bahrami, Ahmad Reza; Bidkhori, Hamid Reza; Mirahmadi, Mahdi; Ahmadiankia, Naghmeh

    2015-01-01

    Stem/progenitor cell-based therapeutic approach in clinical practice has been an elusive dream in medical sciences, and improvement of stem cell homing is one of major challenges in cell therapy programs. Stem/progenitor cells have a homing response to injured tissues/organs, mediated by interactions of chemokine receptors expressed on the cells and chemokines secreted by the injured tissue. For improvement of directed homing of the cells, many techniques have been developed either to engineer stem/progenitor cells with higher amount of chemokine receptors (stem cell-based strategies) or to modulate the target tissues to release higher level of the corresponding chemokines (target tissue-based strategies). This review discusses both of these strategies involved in the improvement of stem cell homing focusing on mesenchymal stem cells as most frequent studied model in cellular therapies.

  9. 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

  10. VISUAL PERCEPTION BASED AUTOMATIC RECOGNITION OF CELL MOSAICS IN HUMAN CORNEAL ENDOTHELIUMMICROSCOPY IMAGES

    Directory of Open Access Journals (Sweden)

    Yann Gavet

    2011-05-01

    Full Text Available The human corneal endothelium can be observed with two types of microscopes: classical optical microscope for ex-vivo imaging, and specular optical microscope for in-vivo imaging. The quality of the cornea is correlated to the endothelial cell density and morphometry. Automatic methods to analyze the human corneal endothelium images are still not totally efficient. Image analysis methods that focus only on cell contours do not give good results in presence of noise and of bad conditions of acquisition. More elaborated methods introduce regional informations in order to performthe cell contours completion, thus implementing the duality contour-region. Their good performance can be explained by their connections with several basic principles of human visual perception (Gestalt Theory and Marr's computational theory.

  11. Alkyne-tag Raman imaging for visualization of mobile small molecules in live cells.

    Science.gov (United States)

    Yamakoshi, Hiroyuki; Dodo, Kosuke; Palonpon, Almar; Ando, Jun; Fujita, Katsumasa; Kawata, Satoshi; Sodeoka, Mikiko

    2012-12-26

    Alkyne has a unique Raman band that does not overlap with Raman scattering from any endogenous molecule in live cells. Here, we show that alkyne-tag Raman imaging (ATRI) is a promising approach for visualizing nonimmobilized small molecules in live cells. An examination of structure-Raman shift/intensity relationships revealed that alkynes conjugated to an aromatic ring and/or to a second alkyne (conjugated diynes) have strong Raman signals in the cellular silent region and can be excellent tags. Using these design guidelines, we synthesized and imaged a series of alkyne-tagged coenzyme Q (CoQ) analogues in live cells. Cellular concentrations of diyne-tagged CoQ analogues could be semiquantitatively estimated. Finally, simultaneous imaging of two small molecules, 5-ethynyl-2'-deoxyuridine (EdU) and a CoQ analogue, with distinct Raman tags was demonstrated.

  12. 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.

  13. Visualizing the effect of tumor microenvironments on radiation-induced cell kinetics in multicellular spheroids consisting of HeLa cells

    Energy Technology Data Exchange (ETDEWEB)

    Kaida, Atsushi; Miura, Masahiko, E-mail: masa.mdth@tmd.ac.jp

    2013-10-04

    Highlights: •We visualized radiation-induced cell kinetics in spheroids. •HeLa-Fucci cells were used for detection of cell-cycle changes. •Radiation-induced G2 arrest was prolonged in the spheroid. •The inner and outer cell fractions behaved differently. -- Abstract: In this study, we visualized the effect of tumor microenvironments on radiation-induced tumor cell kinetics. For this purpose, we utilized a multicellular spheroid model, with a diameter of ∼500 μm, consisting of HeLa cells expressing the fluorescent ubiquitination-based cell-cycle indicator (Fucci). In live spheroids, a confocal laser scanning microscope allowed us to clearly monitor cell kinetics at depths of up to 60 μm. Surprisingly, a remarkable prolongation of G2 arrest was observed in the outer region of the spheroid relative to monolayer-cultured cells. Scale, an aqueous reagent that renders tissues optically transparent, allowed visualization deeper inside spheroids. About 16 h after irradiation, a red fluorescent cell fraction, presumably a quiescent G0 cell fraction, became distinct from the outer fraction consisting of proliferating cells, most of which exhibited green fluorescence indicative of G2 arrest. Thereafter, the red cell fraction began to emit green fluorescence and remained in prolonged G2 arrest. Thus, for the first time, we visualized the prolongation of radiation-induced G2 arrest in spheroids and the differences in cell kinetics between the outer and inner fractions.

  14. Visualization of mitochondrial DNA replication in individual cells by EdU signal amplification.

    Science.gov (United States)

    Haines, Kristine M; Feldman, Eva L; Lentz, Stephen I

    2010-11-15

    Mitochondria are key regulators of cellular energy and mitochondrial biogenesis is an essential component of regulating mitochondria numbers in healthy cells. One approach for monitoring mitochondrial biogenesis is to measure the rate of mitochondrial DNA (mtDNA) replication. We developed a sensitive technique to label newly synthesized mtDNA in individual cells in order to study mtDNA biogenesis. The technique combines the incorporation of 5-ethynyl-2'-deoxyuridine (EdU) with a tyramide signal amplification (TSA) protocol to visualize mtDNA replication within subcellular compartments of neurons. EdU is superior to other thymidine analogs, such as 5-bromo-2-deoxyuridine (BrdU), because the initial click reaction to label EdU does not require the harsh acid treatments or enzyme digests that are required for exposing the BrdU epitope. The milder labeling of EdU allows for direct comparison of its incorporation with other cellular markers. The ability to visualize and quantify mtDNA biogenesis provides an essential tool for investigating the mechanisms used to regulate mitochondrial biogenesis and would provide insight into the pathogenesis associated with drug toxicity, aging, cancer and neurodegenerative diseases. Our technique is applicable to sensory neurons as well as other cell types. The use of this technique to measure mtDNA biogenesis has significant implications in furthering the understanding of both normal cellular physiology as well as impaired disease states.

  15. Focal electrical stimulation of major ganglion cell types in the primate retina for the design of visual prostheses.

    Science.gov (United States)

    Jepson, Lauren H; Hottowy, Pawel; Mathieson, Keith; Gunning, Deborah E; Dabrowski, Wladyslaw; Litke, Alan M; Chichilnisky, E J

    2013-04-24

    Electrical stimulation of retinal neurons with an advanced retinal prosthesis may eventually provide high-resolution artificial vision to the blind. However, the success of future prostheses depends on the ability to activate the major parallel visual pathways of the human visual system. Electrical stimulation of the five numerically dominant retinal ganglion cell types was investigated by simultaneous stimulation and recording in isolated peripheral primate (Macaca sp.) retina using multi-electrode arrays. ON and OFF midget, ON and OFF parasol, and small bistratified ganglion cells could all be activated directly to fire a single spike with submillisecond latency using brief pulses of current within established safety limits. Thresholds for electrical stimulation were similar in all five cell types. In many cases, a single cell could be specifically activated without activating neighboring cells of the same type or other types. These findings support the feasibility of direct electrical stimulation of the major visual pathways at or near their native spatial and temporal resolution.

  16. 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.

  17. 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.

  18. Tools for improving the characterization and visualization of changes in neuro-oncology patients.

    Science.gov (United States)

    Hsu, William; Taira, Ricky K

    2010-11-13

    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, we have created a mapping tool that assigns an observation of a problem to one of nine classes that describe change. The second tool utilizes iconic representations of the nine classes to generate a timeline interface, enabling users to pan, zoom, and filter the data. The result of this preliminary work is an automated approach for understanding and summarizing the evolution of a problem within the patient electronic medical record.

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

    Science.gov (United States)

    Kapoula, Zoï; Lang, Alexandre; Lê, Thanh-Thuan; Adenis, Marie-Sarah; Yang, Qing; Lipede, Gabi; Vernet, Marine

    2014-01-01

    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 hypothesized to have stimulated the body’s vertical and longitudinal axes as it showcased five monumental rectangular solids pitched at a 1.69° angle. Using computerized 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 canceling time (CT) of body sway] at the expense of medio-lateral stability (in terms of CT). Moreover, a medio-lateral instability associated with eye movement exploration before the promenade (in terms of body sway sensu stricto) was canceled after the promenade. Finally, the overall medio-lateral stability (in terms of spectral power) increased after the promenade. Fourteen additional visitors were asked to stand 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. PMID:25566107

  20. The Effect of a Computerized Visual Perception and Visual-Motor Integration Training Program on Improving Chinese Handwriting of Children with Handwriting Difficulties

    Science.gov (United States)

    Poon, K. W.; Li-Tsang, C. W .P.; Weiss, T. P. L.; Rosenblum, S.

    2010-01-01

    This study aimed to investigate the effect of a computerized visual perception and visual-motor integration training program to enhance Chinese handwriting performance among children with learning difficulties, particularly those with handwriting problems. Participants were 26 primary-one children who were assessed by educational psychologists and…

  1. Spatial phase sensitivity of complex cells in primary visual cortex depends on stimulus contrast.

    Science.gov (United States)

    Meffin, H; Hietanen, M A; Cloherty, S L; Ibbotson, M R

    2015-12-01

    Neurons in primary visual cortex are classified as simple, which are phase sensitive, or complex, which are significantly less phase sensitive. Previously, we have used drifting gratings to show that the phase sensitivity of complex cells increases at low contrast and after contrast adaptation while that of simple cells remains the same at all contrasts (Cloherty SL, Ibbotson MR. J Neurophysiol 113: 434-444, 2015; Crowder NA, van Kleef J, Dreher B, Ibbotson MR. J Neurophysiol 98: 1155-1166, 2007; van Kleef JP, Cloherty SL, Ibbotson MR. J Physiol 588: 3457-3470, 2010). However, drifting gratings confound the influence of spatial and temporal summation, so here we have stimulated complex cells with gratings that are spatially stationary but continuously reverse the polarity of the contrast over time (contrast-reversing gratings). By varying the spatial phase and contrast of the gratings we aimed to establish whether the contrast-dependent phase sensitivity of complex cells results from changes in spatial or temporal processing or both. We found that most of the increase in phase sensitivity at low contrasts could be attributed to changes in the spatial phase sensitivities of complex cells. However, at low contrasts the complex cells did not develop the spatiotemporal response characteristics of simple cells, in which paired response peaks occur 180° out of phase in time and space. Complex cells that increased their spatial phase sensitivity at low contrasts were significantly overrepresented in the supragranular layers of cortex. We conclude that complex cells in supragranular layers of cat cortex have dynamic spatial summation properties and that the mechanisms underlying complex cell receptive fields differ between cortical layers.

  2. Use of the Argus II retinal prosthesis to improve visual guidance of fine hand movements

    OpenAIRE

    2012-01-01

    We studied the capabilities of the Argus II retinal prosthesis for guiding fine hand movement, and demonstrated and quantified guidance improvement when using the device over when not using the device for progressively less predictable trajectories.

  3. Visualization of sialic acid produced on bacterial cell surfaces by lectin staining.

    Science.gov (United States)

    Kajiwara, Hitomi; Toda, Munetoyo; Mine, Toshiki; Nakada, Hiroshi; Wariishi, Hiroyuki; Yamamoto, Takeshi

    2010-01-01

    Oligosaccharides containing N-acetylneuraminic acid on the cell surface of some pathogenic bacteria are important for host-microbe interactions. N-acetylneuraminic acid (Neu5Ac) plays a major role in the pathogenicity of bacterial pathogens. For example, cell surface sialyloligosaccharide moieties of the human pathogen Haemophilus influenzae are involved in virulence and adhesion to host cells. In this study, we have established a method of visualizing Neu5Ac linked to a glycoconjugate on the bacterial cell surface based on lectin staining. Photobacterium damselae strain JT0160, known to produce a-2,6-sialyltransferase, was revealed to possess Neu5Ac by HPLC. Using the strain, a strong Sambucus sieboldiana lectin-binding signal was detected. The bacteria producing α-2,6-sialyltransferases could be divided into two groups: those with a lot of α-2,6-linked Neu5Ac on the cell surface and those with a little. In the present study, we developed a useful method for evaluating the relationship between Neu5Ac expression on the cell surface and the degree of virulence of marine bacteria.

  4. Dedifferentiation-reprogrammed mesenchymal stem cells with improved therapeutic potential.

    Science.gov (United States)

    Liu, Yang; Jiang, Xiaohua; Zhang, Xiaohu; Chen, Rui; Sun, Tingting; Fok, Kin Lam; Dong, Jianda; Tsang, Lai Ling; Yi, Shaoqiong; Ruan, Yechun; Guo, Jinghui; Yu, Mei Kuen; Tian, Yuemin; Chung, Yiu Wa; Yang, Mo; Xu, Wenming; Chung, Chin Man; Li, Tingyu; Chan, Hsiao Chang

    2011-12-01

    Stem cell transplantation has been shown to improve functional outcome in degenerative and ischemic disorders. However, low in vivo survival and differentiation potential of the transplanted cells limits their overall effectiveness and thus clinical usage. Here we show that, after in vitro induction of neuronal differentiation and dedifferentiation, on withdrawal of extrinsic factors, mesenchymal stem cells (MSCs) derived from bone marrow, which have already committed to neuronal lineage, revert to a primitive cell population (dedifferentiated MSCs) retaining stem cell characteristics but exhibiting a reprogrammed phenotype distinct from their original counterparts. Of therapeutic interest, the dedifferentiated MSCs exhibited enhanced cell survival and higher efficacy in neuronal differentiation compared to unmanipulated MSCs both in vitro and in vivo, with significantly improved cognition function in a neonatal hypoxic-ischemic brain damage rat model. Increased expression of bcl-2 family proteins and microRNA-34a appears to be the important mechanism giving rise to this previously undefined stem cell population that may provide a novel treatment strategy with improved therapeutic efficacy.

  5. Improved Computational Model of Grid Cells Based on Column Structure

    Institute of Scientific and Technical Information of China (English)

    Yang Zhou; Dewei Wu; Weilong Li; Jia Du

    2016-01-01

    To simulate the firing pattern of biological grid cells, this paper presents an improved computational model of grid cells based on column structure. In this model, the displacement along different directions is processed by modulus operation, and the obtained remainder is associated with firing rate of grid cell. Compared with the original model, the improved parts include that: the base of modulus operation is changed, and the firing rate in firing field is encoded by Gaussian⁃like function. Simulation validates that the firing pattern generated by the improved computational model is more consistent with biological characteristic than original model. Besides, the firing pattern is badly influenced by the cumulative positioning error, but the computational model can also generate the regularly hexagonal firing pattern when the real⁃time positioning results are modified.

  6. 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.

  7. Visualizing the Histotripsy Process: Bubble Cloud-Cancer Cell Interactions in a Tissue-Mimicking Environment.

    Science.gov (United States)

    Vlaisavljevich, Eli; Maxwell, Adam; Mancia, Lauren; Johnsen, Eric; Cain, Charles; Xu, Zhen

    2016-10-01

    Histotripsy is a non-invasive ultrasonic ablation method that uses cavitation to mechanically fractionate tissue into acellular debris. With a sufficient number of pulses, histotripsy can completely fractionate tissue into a liquid-appearing homogenate with no cellular structures. The location, shape and size of lesion formation closely match those of the cavitation cloud. Previous work has led to the hypothesis that the rapid expansion and collapse of histotripsy bubbles fractionate tissue by inducing large stress and strain on the tissue structures immediately adjacent to the bubbles. In the work described here, the histotripsy bulk tissue fractionation process is visualized at the cellular level for the first time using a custom-built 2-MHz transducer incorporated into a microscope stage. A layer of breast cancer cells were cultured within an optically transparent fibrin-based gel phantom to mimic cells inside a 3-D extracellular matrix. To test the hypothesis, the cellular response to single and multiple histotripsy pulses was investigated using high-speed optical imaging. Bubbles were always generated in the extracellular space, and significant cell displacement/deformation was observed for cells directly adjacent to the bubble during both bubble expansion and collapse. The largest displacements were observed during collapse for cells immediately adjacent to the bubble, with cells moving more than 150-300 μm in less than 100 μs. Cells often underwent multiple large deformations (>150% strain) over multiple pulses, resulting in the bisection of cells multiple times before complete removal. To provide theoretical support to the experimental observations, a numerical simulation was conducted using a single-bubble model, which indicated that histotripsy exerts the largest strains and cell displacements in the regions immediately adjacent to the bubble. The experimental and simulation results support our hypothesis, which helps to explain the formation of the

  8. Neural Correlates of Mirror Visual Feedback-Induced Performance Improvements: A Resting-State fMRI Study

    Science.gov (United States)

    Rjosk, Viola; Lepsien, Jöran; Kaminski, Elisabeth; Hoff, Maike; Sehm, Bernhard; Steele, Christopher J.; Villringer, Arno; Ragert, Patrick

    2017-01-01

    Mirror visual feedback (MVF) is a promising approach to enhance motor performance without training in healthy adults as well as in patients with focal brain lesions. There is preliminary evidence that a functional modulation within and between primary motor cortices as assessed with transcranial magnetic stimulation (TMS) might be one candidate mechanism mediating the observed behavioral effects. Recently, studies using task-based functional magnetic resonance imaging (fMRI) have indicated that MVF-induced functional changes might not be restricted to the primary motor cortex (M1) but also include higher order regions responsible for perceptual-motor coordination and visual attention. However, aside from these instantaneous task-induced brain changes, little is known about learning-related neuroplasticity induced by MVF. Thus, in the present study, we assessed MVF-induced functional network plasticity with resting-state fMRI (rs-fMRI). We performed rs-fMRI of 35 right-handed, healthy adults before and after performing a complex ball-rotation task. The primary outcome measure was the performance improvement of the untrained left hand (LH) before and after right hand (RH) training with MVF (mirror group [MG], n = 17) or without MVF (control group [CG], n = 18). Behaviorally, the MG showed superior performance improvements of the untrained LH. In resting-state functional connectivity (rs-FC), an interaction analysis between groups showed changes in left visual cortex (V1, V2) revealing an increase of centrality in the MG. Within group comparisons showed further functional alterations in bilateral primary sensorimotor cortex (SM1), left V4 and left anterior intraparietal sulcus (aIP) in the MG, only. Importantly, a correlation analysis revealed a linear positive relationship between MVF-induced improvements of the untrained LH and functional alterations in left SM1. Our results suggest that MVF-induced performance improvements are associated with functional learning

  9. Kinetic models in industrial biotechnology - Improving cell factory performance.

    Science.gov (United States)

    Almquist, Joachim; Cvijovic, Marija; Hatzimanikatis, Vassily; Nielsen, Jens; Jirstrand, Mats

    2014-07-01

    An increasing number of industrial bioprocesses capitalize on living cells by using them as cell factories that convert sugars into chemicals. These processes range from the production of bulk chemicals in yeasts and bacteria to the synthesis of therapeutic proteins in mammalian cell lines. One of the tools in the continuous search for improved performance of such production systems is the development and application of mathematical models. To be of value for industrial biotechnology, mathematical models should be able to assist in the rational design of cell factory properties or in the production processes in which they are utilized. Kinetic models are particularly suitable towards this end because they are capable of representing the complex biochemistry of cells in a more complete way compared to most other types of models. They can, at least in principle, be used to in detail understand, predict, and evaluate the effects of adding, removing, or modifying molecular components of a cell factory and for supporting the design of the bioreactor or fermentation process. However, several challenges still remain before kinetic modeling will reach the degree of maturity required for routine application in industry. Here we review the current status of kinetic cell factory modeling. Emphasis is on modeling methodology concepts, including model network structure, kinetic rate expressions, parameter estimation, optimization methods, identifiability analysis, model reduction, and model validation, but several applications of kinetic models for the improvement of cell factories are also discussed.

  10. Visualizing the endocytosis of phenylephrine in living cells by quantum dot-based tracking.

    Science.gov (United States)

    Ma, Jing; Wu, Lina; Hou, Zhun; Song, Yao; Wang, Lei; Jiang, Wei

    2014-08-01

    To study the intracellular receptor-drug transportation, a fluorescent probe consisting of phenylephrine-polyethylene glycol-quantum dots conjugate was employed to track endocytosis process of phenylephrine in living cells. This type of movement was studied by continuously filming fluorescent images in the same cell. We also calculated the movement parameters, and divided the endocytosis process into 6 stages. Furthermore, the movement parameters of this probe in different organelles were determined by co-localization of the probe fluorescent images and different cellular organelles. After comparing the parameters in cellular organelles with these in 6 stages, the whole endocytosis pathway was demonstrated. These results verified that this probe successfully tracked the whole intracellular dynamic endocytosis process of phenylephrine. Our method realized the visual tracking the whole receptor-mediated endocytosis, which is a new approach on investigating the molecular mechanisms and kinetic properties of intracellular receptor-drug transportation.

  11. 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.

  12. Using visual aids to improve communication of risks about health: a review.

    Science.gov (United States)

    Garcia-Retamero, Rocio; Okan, Yasmina; Cokely, Edward T

    2012-01-01

    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.

  13. 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.

  14. 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

  15. Solar cell nanotechnology for improved efficiency and radiation hardness

    Science.gov (United States)

    Fedoseyev, Alexander I.; Turowski, Marek; Shao, Qinghui; Balandin, Alexander A.

    2006-08-01

    Space electronic equipment, and NASA future exploration missions in particular, require improvements in solar cell efficiency and radiation hardness. Novel nano-engineered materials and quantum-dot array based photovoltaic devices promise to deliver more efficient, lightweight solar cells and arrays which will be of high value to long term space missions. In this paper, we describe issues related to the development of the quantum-dot based solar cells and comprehensive software tools for simulation of the nanostructure-based photovoltaic cells. Some experimental results used for the model validation are also reviewed. The novel modeling and simulation tools for the quantum-dot-based nanostructures help to better understand and predict behavior of the nano-devices and novel materials in space environment, assess technologies, devices, and materials for new electronic systems as well as to better evaluate the performance and radiation response of the devices at an early design stage. The overall objective is to investigate and design new photovoltaic structures based on quantum dots (QDs) with improved efficiency and radiation hardness. The inherently radiation tolerant quantum dots of variable sizes maximize absorption of different light wavelengths, i.e., create a "multicolor" cell, which improves photovoltaic efficiency and diminishes the radiation-induced degradation. The QD models described here are being integrated into the advanced photonic-electronic device simulator NanoTCAD, which can be useful for the optimization of QD superlattices as well as for the development and exploring of new solar cell designs.

  16. Pyramidal cells make specific connections onto smooth (GABAergic neurons in mouse visual cortex.

    Directory of Open Access Journals (Sweden)

    Rita Bopp

    2014-08-01

    Full Text Available One of the hallmarks of neocortical circuits is the predominance of recurrent excitation between pyramidal neurons, which is balanced by recurrent inhibition from smooth GABAergic neurons. It has been previously described that in layer 2/3 of primary visual cortex (V1 of cat and monkey, pyramidal cells filled with horseradish peroxidase connect approximately in proportion to the spiny (excitatory, 95% and 81%, respectively and smooth (GABAergic, 5% and 19%, respectively dendrites found in the neuropil. By contrast, a recent ultrastructural study of V1 in a single mouse found that smooth neurons formed 51% of the targets of the superficial layer pyramidal cells. This suggests that either the neuropil of this particular mouse V1 had a dramatically different composition to that of V1 in cat and monkey, or that smooth neurons were specifically targeted by the pyramidal cells in that mouse. We tested these hypotheses by examining similar cells filled with biocytin in a sample of five mice. We found that the average composition of the neuropil in V1 of these mice was similar to that described for cat and monkey V1, but that the superficial layer pyramidal cells do form proportionately more synapses with smooth dendrites than the equivalent neurons in cat or monkey. These distributions may underlie the distinct differences in functional architecture of V1 between rodent and higher mammals.

  17. Improved visualization of fat body conditions and abundance in the southern green stink bug (Hemiptera: Pentatomidae)

    Science.gov (United States)

    Fat bodies are a crucial source of energy for insect survival and reproduction. Differing types of fat body cells and amounts have been previously reported for southern green stink bug but clear supporting images are lacking. Further, in ongoing studies elucidating the ecology of southern green st...

  18. Evaluation of the potential of phase-contrast computed tomography for improved visualization of cancerous human liver tissue

    Energy Technology Data Exchange (ETDEWEB)

    Noel, Peter B.; Fingerle, Alexander A. [Technische Univ. Muenchen (Germany). Dept. of Radiology; Herzen, Julia [Technische Univ. Muenchen (Germany). Physics Dept. and Inst. of Medical Engineering] [and others

    2013-10-01

    Purpose: Phase-contrast X-ray computed tomography (PCCT) is currently investigated and developed as a potentially very interesting extension of conventional CT, and can offer several advantages for specific indications in diagnostic imaging. Current absorption-based computed tomography (CT) without the application of contrast material is limited in the detection of minor density differences in soft-tissue. The purpose of this study is to test whether PCCT can improve soft tissue contrast in healthy and tumorous human liver specimens. Materials and Methods: Two specimens of human liver (one healthy and one metastasized liver sample) were imaged with brilliant X-ray beam at the synchrotron radiation source ESRF in Grenoble, France. For correlation the same specimens were imaged with a magnetic resonance imaging system at 1.5 T. The histopathology confirmed our findings in the corresponding sections of the specimens. Results: In the phase-contrast CT images we observed a significantly enhanced soft-tissue contrast when compared to simultaneously recorded standard absorption CT measurements. Further, we found that the pathological and morphological information in the PCCT reconstructions show significant improvement when compared to those performed on MRI. Based on matching of prominent features, a good correlation between PCCT and the histological section is demonstrated; especially the tumor capsule and the surrounding vascular structures are visible in PCCT. In addition, our study revealed the ability of PCCT to visualize the blood vessels structure in the tumorous liver without the need of any contrast agents. Conclusion: Grating-based PCCT significantly improves the soft-tissue contrast in ex-vivo liver specimens and holds the potential to overcome the need of contrast materials for visualization of the tumor vascularization. (orig.)

  19. Mirror Visual Feedback Training Improves Intermanual Transfer in a Sport-Specific Task: A Comparison between Different Skill Levels

    Directory of Open Access Journals (Sweden)

    Fabian Steinberg

    2016-01-01

    Full Text Available Mirror training therapy is a promising tool to initiate neural plasticity and facilitate the recovery process of motor skills after diseases such as stroke or hemiparesis by improving the intermanual transfer of fine motor skills in healthy people as well as in patients. This study evaluated whether these augmented performance improvements by mirror visual feedback (MVF could be used for learning a sport-specific skill and if the effects are modulated by skill level. A sample of 39 young, healthy, and experienced basketball and handball players and 41 novices performed a stationary basketball dribble task at a mirror box in a standing position and received either MVF or direct feedback. After four training days using only the right hand, performance of both hands improved from pre- to posttest measurements. Only the left hand (untrained performance of the experienced participants receiving MVF was more pronounced than for the control group. This indicates that intermanual motor transfer can be improved by MVF in a sport-specific task. However, this effect cannot be generalized to motor learning per se since it is modulated by individuals’ skill level, a factor that might be considered in mirror therapy research.

  20. Mirror Visual Feedback Training Improves Intermanual Transfer in a Sport-Specific Task: A Comparison between Different Skill Levels

    Science.gov (United States)

    Pixa, Nils Henrik; Doppelmayr, Michael

    2016-01-01

    Mirror training therapy is a promising tool to initiate neural plasticity and facilitate the recovery process of motor skills after diseases such as stroke or hemiparesis by improving the intermanual transfer of fine motor skills in healthy people as well as in patients. This study evaluated whether these augmented performance improvements by mirror visual feedback (MVF) could be used for learning a sport-specific skill and if the effects are modulated by skill level. A sample of 39 young, healthy, and experienced basketball and handball players and 41 novices performed a stationary basketball dribble task at a mirror box in a standing position and received either MVF or direct feedback. After four training days using only the right hand, performance of both hands improved from pre- to posttest measurements. Only the left hand (untrained) performance of the experienced participants receiving MVF was more pronounced than for the control group. This indicates that intermanual motor transfer can be improved by MVF in a sport-specific task. However, this effect cannot be generalized to motor learning per se since it is modulated by individuals' skill level, a factor that might be considered in mirror therapy research. PMID:27642526

  1. Focal Electrical Stimulation of Major Ganglion Cell Types in the Primate Retina for the Design of Visual Prostheses

    OpenAIRE

    2013-01-01

    Electrical stimulation of retinal neurons with an advanced retinal prosthesis may eventually provide high-resolution artificial vision to the blind. However, the success of future prostheses depends on the ability to activate the major parallel visual pathways of the human visual system. Electrical stimulation of the five numerically dominant retinal ganglion cell types was investigated by simultaneous stimulation and recording in isolated peripheral primate (Macaca sp.) retina using multi-el...

  2. Distributed data discovery, access and visualization services to Improve Data Interoperability across different data holdings

    Science.gov (United States)

    Palanisamy, G.; Krassovski, M.; Devarakonda, R.; Santhana Vannan, S.

    2012-12-01

    The current climate debate is highlighting the importance of free, open, and authoritative sources of high quality climate data that are available for peer review and for collaborative purposes. It is increasingly important to allow various organizations around the world to share climate data in an open manner, and to enable them to perform dynamic processing of climate data. This advanced access to data can be enabled via Web-based services, using common "community agreed" standards without having to change their internal structure used to describe the data. The modern scientific community has become diverse and increasingly complex in nature. To meet the demands of such diverse user community, the modern data supplier has to provide data and other related information through searchable, data and process oriented tool. This can be accomplished by setting up on-line, Web-based system with a relational database as a back end. The following common features of the web data access/search systems will be outlined in the proposed presentation: - A flexible data discovery - Data in commonly used format (e.g., CSV, NetCDF) - Preparing metadata in standard formats (FGDC, ISO19115, EML, DIF etc.) - Data subseting capabilities and ability to narrow down to individual data elements - Standards based data access protocols and mechanisms (SOAP, REST, OpenDAP, OGC etc.) - Integration of services across different data systems (discovery to access, visualizations and subseting) This presentation will also include specific examples of integration of various data systems that are developed by Oak Ridge National Laboratory's - Climate Change Science Institute, their ability to communicate between each other to enable better data interoperability and data integration. References: [1] Devarakonda, Ranjeet, and Harold Shanafield. "Drupal: Collaborative framework for science research." Collaboration Technologies and Systems (CTS), 2011 International Conference on. IEEE, 2011. [2

  3. 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.

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

    Science.gov (United States)

    Nikouei Mahani, Mohammad-Ali; 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.

  5. 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.

  6. 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.

  7. 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...

  8. Improving Perovskite Solar Cells: Insights From a Validated Device Model

    NARCIS (Netherlands)

    Sherkar, Tejas S.; Momblona, Cristina; Gil-Escrig, Lidon; Bolink, Henk J.; Koster, L. Jan Anton

    2017-01-01

    To improve the efficiency of existing perovskite solar cells (PSCs), a detailed understanding of the underlying device physics during their operation is essential. Here, a device model has been developed and validated that describes the operation of PSCs and quantitatively explains the role of conta

  9. The Geology Robot: A Collaborative Effort for improving Outcrop Visualization and Analysis

    Science.gov (United States)

    Fredrick, K. C.; Valoski, M. P.; Rodi, A. F.

    2010-12-01

    Geologic mapping is one of the most important skills a geologist will attempt to master during their education and well into their career. Mapping requires the ability to identify rocks and minerals, an understanding of geologic principles of history, deformation, and tectonics, as well as the ability to access the geology in question. As a student, the first two items are cognitive, and generally gained through education and experience. However, the third involves external, especially physical factors, often outside of a student’s control. Mapping and outcrop analysis can be difficult in areas of especially varied terrain depending on one’s will and physical ability. In our area of southwestern Pennsylvania, steep terrain and dense vegetation dominate the landscape. Road cuts are often the only options for identifying local bedrock. Many outcrops are avoided based on their sheer size or integrity, which can pose risks of physical harm. In order to address some of these concerns, we have developed a robot, able to scale and image rocks in the vertical. The principle behind the robot’s capabilities is to reach steep or over-steep cliff faces to view and measure rock type and stratigraphic relationships. The robot carries a movable camera, allowing the operator a clear view of the rock face in an area that he or she wouldn’t normally be able to access. The robot is suspended from climbing rope over the cliff edge and connected to a power source and video monitor. The current prototype is operated with a handheld remote control including independent camera manipulation. Future development may include detachable wheel tracks for navigating less than vertical surfaces and a coring bit for sampling. Potential uses exist beyond visualization for classroom instruction, including detailed mapping, evaluating geological engineering challenges, viewing down-well conditions in large-bore wells, etc. We believe this robot will allow students (and possibly professionals

  10. Visualization of abscisic acid-perception sites on the plasma membrane of stomatal guard cells.

    Science.gov (United States)

    Yamazaki, Daiki; Yoshida, Shigeo; Asami, Tadao; Kuchitsu, Kazuyuki

    2003-07-01

    Abscisic acid (ABA) is a phytohormone that plays a key role as a stress signal, regulating water relations during drought conditions, by inducing stomatal closure. However, to date, no putative ABA receptor(s) has been reported at the protein sequence, gene family, or cellular localization levels. We used biotinylated ABA (bioABA) to characterize the ABA-perception sites in the stomatal guard cells of Vicia faba. Treatment with bioABA induced stomatal closure and shrinkage of guard cell protoplasts (GCPs). The ABA-perception sites were visualized by fluorescence microscopy and confocal laser scanning microscopy (CLSM), using bioABA and fluorescence-labeled avidin. Fluorescent particles were observed in patches on the surface of the GCPs. Fluorescence intensity was quantified by flow cytometry (FCM) as well as by CLSM. Binding of bioABA was inhibited by ABA in a dose-dependent manner. Pre-treatment of GCPs with proteinase K also blocked the binding of bioABA. Binding of bioABA was inhibited by RCA-7a, an ABA analog that induces stomatal closure, but not by RCA-16, which has no effect on stomatal aperture. Another ABA analog, PBI-51, inhibited ABA-induced stomatal closure. This ABA antagonist also inhibited binding of bioABA to the GCPs. These results suggest that ABA is perceived on the plasma membrane of stomatal guard cells, and that the present experimental methods constitute valuable tools for characterizing the nature of the ABA receptor(s) that perceives physiological ABA signals. These imaging studies allow us to demonstrate the spatial distribution of the ABA-perception sites. Visualization of the ABA-perception sites provides new insights into the nature of membrane-associated ABA receptor(s).

  11. 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.

  12. 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.

  13. 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.

  14. Molten carbonate fuel cell technology improvement. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1991-06-01

    This report summarizes the work performed under Department of Energy Contract DEAC21-87MC23270, ``Molten Carbonate Fuel Cell Technology Improvement.`` This work was conducted over a three year period and consisted of three major efforts. The first major effort was the power plant system study which reviewed the competitive requirements for a coal gasifier/molten carbonate fuel cell power plant, produced a conceptual design of a CG/MCFC, and defined the technology development requirements. This effort is discussed in Section 1 of the report. The second major effort involved the design and development of a new MCFC cell configuration which reduced the material content of the cell to a level competitive with competing power plants, simplified the cell configuration to make the components more manufacturable and adaptable to continuous low cost processing techniques, and introduced new-low-pressure drop flow fields for both reactant gases. The new flow fields permitted the incorporation of recirculation systems in both reactant gas systems, permitting simplified cooling techniques and the ability to operate on both natural gas and a wide variety of gasifier fuels. This cell technology improvement is discussed in Section 2. The third major effort involved the scaleup of the new cell configuration to the full-area, 8-sq-ft size and resulted in components used for a 25-kW, 20-cell stack verification test. The verification test was completed with a run of 2200 hours, exceeding the goal of 2000 hours and verifying the new cell design. TWs test, in turn, provided the confidence to proceed to a 100-kW demonstration which is the goal of the subsequent DOE program. The scaleup and stack verification tests are discussed in Sections 3, 4, 5, and 6 of this report.

  15. Visual input enhancement via essay coding results in deaf learners' long-term retention of improved English grammatical knowledge.

    Science.gov (United States)

    Berent, Gerald P; Kelly, Ronald R; Schmitz, Kathryn L; Kenney, Patricia

    2009-01-01

    This study explored the efficacy of visual input enhancement, specifically essay enhancement, for facilitating deaf college students' improvement in English grammatical knowledge. Results documented students' significant improvement immediately after a 10-week instructional intervention, a replication of recent research. Additionally, the results of delayed assessment documented students' significant retention of that improvement five and a half months beyond the instructional intervention period. Essay enhancement served to highlight, via a coding procedure, students' successful and unsuccessful production of discourse-required target grammatical structures. The procedure converted students' written communicative output into enhanced input for inducing noticing of grammatical form and, through essay revision, establishing form-meaning connections leading to acquisition. With its optimal design characteristics supported by theoretical and empirical research, essay enhancement is a highly effective methodology that can be easily implemented as primary or supplementary English instruction for deaf students. The results of this study hold great promise for facilitating deaf students' English language and literacy development and have broad implications for second-language research, teaching, and learning.

  16. Visualization of Mesenchymal Stromal Cells in 2Dand 3D-Cultures by Scanning Electron Microscopy with Lanthanide Contrasting.

    Science.gov (United States)

    Novikov, I A; Vakhrushev, I V; Antonov, E N; Yarygin, K N; Subbot, A M

    2017-02-01

    Mesenchymal stromal cells from deciduous teeth in 2D- and 3D-cultures on culture plastic, silicate glass, porous polystyrene, and experimental polylactoglycolide matrices were visualized by scanning electron microscopy with lanthanide contrasting. Supravital staining of cell cultures with a lanthanide-based dye (neodymium chloride) preserved normal cell morphology and allowed assessment of the matrix properties of the carriers. The developed approach can be used for the development of biomaterials for tissue engineering.

  17. Turtle Dorsal Cortex Pyramidal Neurons Comprise Two Distinct Cell Types with Indistinguishable Visual Responses.

    Directory of Open Access Journals (Sweden)

    Thomas Crockett

    Full Text Available A detailed inventory of the constituent pieces in cerebral cortex is considered essential to understand the principles underlying cortical signal processing. Specifically, the search for pyramidal neuron subtypes is partly motivated by the hypothesis that a subtype-specific division of labor could create a rich substrate for computation. On the other hand, the extreme integration of individual neurons into the collective cortical circuit promotes the hypothesis that cellular individuality represents a smaller computational role within the context of the larger network. These competing hypotheses raise the important question to what extent the computational function of a neuron is determined by its individual type or by its circuit connections. We created electrophysiological profiles from pyramidal neurons within the sole cellular layer of turtle visual cortex by measuring responses to current injection using whole-cell recordings. A blind clustering algorithm applied to these data revealed the presence of two principle types of pyramidal neurons. Brief diffuse light flashes triggered membrane potential fluctuations in those same cortical neurons. The apparently network driven variability of the visual responses concealed the existence of subtypes. In conclusion, our results support the notion that the importance of diverse intrinsic physiological properties is minimized when neurons are embedded in a synaptic recurrent network.

  18. Allogeneic Transplantation of Müller-Derived Retinal Ganglion Cells Improves Retinal Function in a Feline Model of Ganglion Cell Depletion.

    Science.gov (United States)

    Becker, Silke; Eastlake, Karen; Jayaram, Hari; Jones, Megan F; Brown, Robert A; McLellan, Gillian J; Charteris, David G; Khaw, Peng T; Limb, G Astrid

    2016-02-01

    Human Müller glia with stem cell characteristics (hMGSCs) have been shown to improve retinal function upon transplantation into rat models of retinal ganglion cell (RGC) depletion. However, their translational potential may depend upon successful engraftment and improvement of retinal function in experimental models with anatomical and functional features resembling those of the human eye. We investigated the effect of allogeneic transplantation of feline Müller glia with the ability to differentiate into cells expressing RGC markers, following ablation of RGCs by N-methyl-d-aspartate (NMDA). Unlike previous observations in the rat, transplantation of hMGSC-derived RGCs into the feline vitreous formed aggregates and elicited a severe inflammatory response without improving visual function. In contrast, allogeneic transplantation of feline MGSC (fMGSC)-derived RGCs into the vitrectomized eye improved the scotopic threshold response (STR) of the electroretinogram (ERG). Despite causing functional improvement, the cells did not attach onto the retina and formed aggregates on peripheral vitreous remnants, suggesting that vitreous may constitute a barrier for cell attachment onto the retina. This was confirmed by observations that cellular scaffolds of compressed collagen and enriched preparations of fMGSC-derived RGCs facilitated cell attachment. Although cells did not migrate into the RGC layer or the optic nerve, they significantly improved the STR and the photopic negative response of the ERG, indicative of increased RGC function. These results suggest that MGSCs have a neuroprotective ability that promotes partial recovery of impaired RGC function and indicate that cell attachment onto the retina may be necessary for transplanted cells to confer neuroprotection to the retina. Significance: Müller glia with stem cell characteristics are present in the adult human retina, but they do not have regenerative ability. These cells, however, have potential for

  19. Improving the photovoltaic performance of perovskite solar cells with acetate.

    Science.gov (United States)

    Zhao, Qian; Li, G R; Song, Jian; Zhao, Yulong; Qiang, Yinghuai; Gao, X P

    2016-12-09

    In an all-solid-state perovskite solar cell, methylammonium lead halide film is in charge of generating photo-excited electrons, thus its quality can directly influence the final photovoltaic performance of the solar cell. This paper accentuates a very simple chemical approach to improving the quality of a perovskite film with a suitable amount of acetic acid. With introduction of acetate ions, a homogeneous, continual and hole-free perovskite film comprised of high-crystallinity grains is obtained. UV-visible spectra, steady-state and time-resolved photoluminescence (PL) spectra reveal that the obtained perovskite film under the optimized conditions shows a higher light absorption, more efficient electron transport, and faster electron extraction to the adjoining electron transport layer. The features result in the optimized perovskite film can provide an improved short-circuit current. The corresponding solar cells with a planar configuration achieves an improved power conversion efficiency of 13.80%, and the highest power conversion efficiency in the photovoltaic measurements is up to 14.71%. The results not only provide a simple approach to optimizing perovskite films but also present a novel angle of view on fabricating high-performance perovskite solar cells.

  20. Improving the photovoltaic performance of perovskite solar cells with acetate

    Science.gov (United States)

    Zhao, Qian; Li, G. R.; Song, Jian; Zhao, Yulong; Qiang, Yinghuai; Gao, X. P.

    2016-12-01

    In an all-solid-state perovskite solar cell, methylammonium lead halide film is in charge of generating photo-excited electrons, thus its quality can directly influence the final photovoltaic performance of the solar cell. This paper accentuates a very simple chemical approach to improving the quality of a perovskite film with a suitable amount of acetic acid. With introduction of acetate ions, a homogeneous, continual and hole-free perovskite film comprised of high-crystallinity grains is obtained. UV-visible spectra, steady-state and time-resolved photoluminescence (PL) spectra reveal that the obtained perovskite film under the optimized conditions shows a higher light absorption, more efficient electron transport, and faster electron extraction to the adjoining electron transport layer. The features result in the optimized perovskite film can provide an improved short-circuit current. The corresponding solar cells with a planar configuration achieves an improved power conversion efficiency of 13.80%, and the highest power conversion efficiency in the photovoltaic measurements is up to 14.71%. The results not only provide a simple approach to optimizing perovskite films but also present a novel angle of view on fabricating high-performance perovskite solar cells.

  1. 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.

  2. Dynamic visualization the whole process of cytotoxic T lymphocytes killing the B16 tumor cells in vitro

    Science.gov (United States)

    Qi, Shuhong; Zhang, Zhihong

    2016-03-01

    Cytotoxic T lymphocytes (CTLs) played a key role in the immune system to destroy the tumor cells. Although some mechanisms of CTLs killing the tumor cells are revealed already, the dynamic information of CTLs interaction with tumor cells are still not known very clearly. Here we used confocal microscopy to visualize the whole process of CTLs killing the tumor cells in vitro. The imaging data showed that CTLs destroyed the target tumor cells rapidly and efficiently. Several CTLs surrounded one or some tumor cells and the average time for CTLs destroying one tumor cell is just a few minutes in vitro. The study displayed the temporal events of CTLs interacting with tumor cells at the beginning and finally killing them and directly presented the efficient tumor cell cytotoxicity of the CTLs. The results helped us to deeply understand the mechanism of the CTLs destroying the tumor cells and to develop the cancer immunotherapy.

  3. Direct visualization of both DNA and RNA quadruplexes in human cells via an uncommon spectroscopic method

    Science.gov (United States)

    Laguerre, Aurélien; Wong, Judy M. Y.; Monchaud, David

    2016-01-01

    Guanine-rich DNA or RNA sequences can fold into higher-order, four-stranded structures termed quadruplexes that are suspected to play pivotal roles in cellular mechanisms including the control of the genome integrity and gene expression. However, the biological relevance of quadruplexes is still a matter of debate owing to the paucity of unbiased evidences of their existence in cells. Recent reports on quadruplex-specific antibodies and small-molecule fluorescent probes help dispel reservations and accumulating evidences now pointing towards the cellular relevance of quadruplexes. To better assess and comprehend their biology, developing new versatile tools to detect both DNA and RNA quadruplexes in cells is essential. We report here a smart fluorescent probe that allows for the simple detection of quadruplexes thanks to an uncommon spectroscopic mechanism known as the red-edge effect (REE). We demonstrate that this effect could open avenues to greatly enhance the ability to visualize both DNA and RNA quadruplexes in human cells, using simple protocols and fluorescence detection facilities. PMID:27535322

  4. Advanced Non-Destructive Ocular Visualization Methods by Improved X-Ray Imaging Techniques

    Science.gov (United States)

    Scherer, Kai; Werner, Jens U.; Lang, Gerhard K.; Lang, Gabriele E.; Pfeiffer, Franz; Noël, Peter; Rummeny, Ernst; Herzen, Julia

    2017-01-01

    Due to limited X-ray contrast, the use of micro-CT in histology is so far not as widespread as predicted. While specific staining procedures—mostly using iodine—address this shortcoming, long diffusion times restrict its use in the often time-constrained daily routine. Recently, a novel staining protocol has been proposed using a biochemical preconditioning step, which increases the permeability of the cells for the staining agent. This could enable the imaging of entire organs of small mammals at a yet unmatched image quality with reasonable preparation and scan times. We here propose an adaptation of this technique for virtual ophthalmology and histology by volumetrically assessing both human and porcine eyes. Hereby, we demonstrate that (contrast-enhanced) micro-CT can outperform conventional histology in the assessment of tumor entities, as well as functioning as a supplementary tool for surgeons in the positioning of intraocular implants in-vitro and as a general assessment tool for ophthalmologic specimens. PMID:28129364

  5. Improved generalized cell mapping for global analysis of dynamical systems

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Three main parts of generalized cell mapping are improved for global analysis. A simple method, which is not based on the theory of digraphs, is presented to locate complete self-cycling sets that corre- spond to attractors and unstable invariant sets involving saddle, unstable periodic orbit and chaotic saddle. Refinement for complete self-cycling sets is developed to locate attractors and unstable in- variant sets with high degree of accuracy, which can start with a coarse cell structure. A nonuniformly interior-and-boundary sampling technique is used to make the refinement robust. For homeomorphic dissipative dynamical systems, a controlled boundary sampling technique is presented to make gen- eralized cell mapping method with refinement extremely accurate to obtain invariant sets. Recursive laws of group absorption probability and expected absorption time are introduced into generalized cell mapping, and then an optimal order for quantitative analysis of transient cells is established, which leads to the minimal computational work. The improved method is applied to four examples to show its effectiveness in global analysis of dynamical systems.

  6. Improved generalized cell mapping for global analysis of dynamical systems

    Institute of Scientific and Technical Information of China (English)

    ZOU HaiLin; XU JianXue

    2009-01-01

    Three main parts of generalized cell mapping are improved for global analysis. A simple method, whichis not based on the theory of digraphs, is presented to locate complete self-cycling sets that corre-spond to attractors and unstable invariant sets involving saddle, unstable periodic orbit and chaotic saddle. Refinement for complete self-cycling sets is developed to locate attractors and unstable in-variant sets with high degree of accuracy, which can start with a coarse cell structure. A nonuniformly interior-and-boundary sampling technique is used to make the refinement robust. For homeomorphic dissipative dynamical systems, a controlled boundary sampling technique is presented to make gen-eralized cell mapping method with refinement extremely accurate to obtain invariant sets. Recursive laws of group absorption probability and expected absorption time are introduced into generalized cell mapping, and then an optimal order for quantitative analysis of transient cells is established, which leads to the minimal computational work. The improved method is applied to four examples to show its effectiveness in global analysis of dynamical systems.

  7. RepeatsDB 2.0: improved annotation, classification, search and visualization of repeat protein structures

    Science.gov (United States)

    Paladin, Lisanna; Hirsh, Layla; Piovesan, Damiano; Andrade-Navarro, Miguel A.; Kajava, Andrey V.; Tosatto, Silvio C.E.

    2017-01-01

    RepeatsDB 2.0 (URL: http://repeatsdb.bio.unipd.it/) is an update of the database of annotated tandem repeat protein structures. Repeat proteins are a widespread class of non-globular proteins carrying heterogeneous functions involved in several diseases. Here we provide a new version of RepeatsDB with an improved classification schema including high quality annotations for ∼5400 protein structures. RepeatsDB 2.0 features information on start and end positions for the repeat regions and units for all entries. The extensive growth of repeat unit characterization was possible by applying the novel ReUPred annotation method over the entire Protein Data Bank, with data quality is guaranteed by an extensive manual validation for >60% of the entries. The updated web interface includes a new search engine for complex queries and a fully re-designed entry page for a better overview of structural data. It is now possible to compare unit positions, together with secondary structure, fold information and Pfam domains. Moreover, a new classification level has been introduced on top of the existing scheme as an independent layer for sequence similarity relationships at 40%, 60% and 90% identity. PMID:27899671

  8. Visually Improved Image Compression by using Embedded Zero-tree Wavelet Coding

    Directory of Open Access Journals (Sweden)

    Janaki R

    2011-03-01

    Full Text Available Image compression is very important for efficient transmission and storage of images. Embedded Zero- tree Wavelet (EZW algorithm is a simple yet powerful algorithm having the property that the bits in the stream are generated in the order of their importance. Image compression can improve the performance of the digital systems by reducing time and cost in image storage and transmission without significant reduction of the image quality. For image compression it is desirable that the selection of transform should reduce the size of resultant data set as compared to source data set. EZW is computationally very fast and among the best image compression algorithm known today. This paper proposes a technique for image compression which uses the Wavelet-based Image Coding. A large number of experimental results are shown that this method saves a lot of bits in transmission, further enhances the compression performance. This paper aims to determine the best threshold to compress the still image at a particular decomposition level by using Embedded Zero-tree Wavelet encoder. Compression Ratio (CR and Peak-Signal-to-Noise (PSNR is determined for different threshold values ranging from 6 to 60 for decomposition level 8.

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    Rui-ping Zhang

    2015-01-01

    Full Text Available 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 the lesion site. Prussian blue staining showed that more bone marrow mesenchymal stem cells reached the lesion site in these rats than in those without magnetic guidance or superparamagnetic iron oxide labeling, and immunofluorescence 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 guidance. Our data confirm that superparamagnetic iron oxide nanoparticles effectively label bone marrow mesenchymal stem cells and impart sufficient magnetism to respond to the external magnetic field guides. More importantly, superparamagnetic iron oxide-labeled bone marrow mesenchymal stem cells can be dynamically and non-invasively tracked in 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.

  11. 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.

  12. Differences in Visual-Spatial Input May Underlie Different Compression Properties of Firing Fields for Grid Cell Modules in Medial Entorhinal Cortex.

    Science.gov (United States)

    Raudies, Florian; Hasselmo, Michael E

    2015-11-01

    Firing fields of grid cells in medial entorhinal cortex show compression or expansion after manipulations of the location of environmental barriers. This compression or expansion could be selective for individual grid cell modules with particular properties of spatial scaling. We present a model for differences in the response of modules to barrier location that arise from different mechanisms for the influence of visual features on the computation of location that drives grid cell firing patterns. These differences could arise from differences in the position of visual features within the visual field. When location was computed from the movement of visual features on the ground plane (optic flow) in the ventral visual field, this resulted in grid cell spatial firing that was not sensitive to barrier location in modules modeled with small spacing between grid cell firing fields. In contrast, when location was computed from static visual features on walls of barriers, i.e. in the more dorsal visual field, this resulted in grid cell spatial firing that compressed or expanded based on the barrier locations in modules modeled with large spacing between grid cell firing fields. This indicates that different grid cell modules might have differential properties for computing location based on visual cues, or the spatial radius of sensitivity to visual cues might differ between modules.

  13. High frequency, cell type-specific visualization of fluorescent-tagged genomic sites in interphase and mitotic cells of living Arabidopsis plants

    Directory of Open Access Journals (Sweden)

    van der Winden Johannes

    2010-01-01

    on the promoter used to drive expression of the RP-FP fusion protein gene, the fluorescent tagged sites can be visualized at high frequency in different cell types. The ability to observe fluorescent dots on both interphase and mitotic chromosomes allows tagged sites to be tracked throughout the cell cycle. These improvements enhance the versatility of the fluorescent tagging technique for future studies of chromosome arrangement and dynamics in living plants.

  14. Long-Term Electrophysiological and Behavioral Analysis on the Improvement of Visual Working Memory Load, Training Gains, and Transfer Benefits.

    Science.gov (United States)

    Kuo, Ching-Chang; Zhang, Cheng; Rissman, Robert A; Chiu, Alan W L

    2014-05-01

    Recent evidence demonstrates that with training, one can enhance visual working memory (VWM) capacity and attention over time in the near transfer tasks. Not only do these studies reveal the characteristics of VWM load and the influences of training, they may also provide insights into developing effective rehabilitation for patients with VWM deficiencies. However, few studies have investigated VWM over extended periods of time and evaluated transfer benefits on non-trained tasks. Here, we combined behavioral and electroencephalographical approaches to investigate VWM load, training gains, and transfer benefits. Our results reveal that VWM capacity is directly correlated to the difference of event-related potential waveforms. In particular, the "magic number 4" can be observed through the contralateral delay amplitude and the average capacity is 3.25-item over 15 participants. Furthermore, our findings indicate that VWM capacity can be improved through training; and after training exercises, participants from the training group are able to dramatically improve their performance. Likewise, the training effects on non-trained tasks can also be observed at the 12th week after training. Therefore, we conclude that participants can benefit from training gains, and augmented VWM capacity sustained over long periods of time on specific variety of tasks.

  15. 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.

  16. Improvement of Dye Solar Cell Efficiency by Photoanode Posttreatment

    Directory of Open Access Journals (Sweden)

    Tanja Ivanovska

    2014-01-01

    Full Text Available The basic concept for efficiency improvement in dye-sensitized solar cells (DSSC is limiting the electron-hole recombination. One way to approach the problem is to improve the photogenerated charge carriers lifetime and consequently reduce their recombination probability. We are reporting on a facile posttreatment of the mesoporous photoanode by using a colloidal solution of TiO2 nanoparticles. We have investigated the outcome of the different sintering temperature of the posttreated photoanodes on their morphology as well as on the conversion efficiency of the DSSC. The DSSCs composed of posttreated photoanodes at 450°C showed an increase in JSC and consequently an increase in efficiency of 10%. Investigations were made to determine the electron recombination via the electrolyte by the OCVD technique. We found that the posttreatment has the effect of reducing the surface trap states and thus increases the electron lifetime, which is responsible for the increase of the overall cell efficiency.

  17. Use of fluorescent proteins and color-coded imaging to visualize cancer cells with different genetic properties.

    Science.gov (United States)

    Hoffman, Robert M

    2016-03-01

    Fluorescent proteins are very bright and available in spectrally-distinct colors, enable the imaging of color-coded cancer cells growing in vivo and therefore the distinction of cancer cells with different genetic properties. Non-invasive and intravital imaging of cancer cells with fluorescent proteins allows the visualization of distinct genetic variants of cancer cells down to the cellular level in vivo. Cancer cells with increased or decreased ability to metastasize can be distinguished in vivo. Gene exchange in vivo which enables low metastatic cancer cells to convert to high metastatic can be color-coded imaged in vivo. Cancer stem-like and non-stem cells can be distinguished in vivo by color-coded imaging. These properties also demonstrate the vast superiority of imaging cancer cells in vivo with fluorescent proteins over photon counting of luciferase-labeled cancer cells.

  18. 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.

  19. 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.

  20. 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...

  1. 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.

  2. Functional visual improvement after cataract surgery in eyes with age-related macular degeneration; Results of the Ophthalmic Surgical Outcomes Data (OSOD) Project.

    Science.gov (United States)

    Stock, Michael V; Vollman, David E; Baze, Elizabeth F; Chomsky, Amy S; Daly, Mary K; Lawrence, Mary

    2015-03-03

    Purpose: To determine if cataract surgery on eyes with age-related macular degeneration (AMD) confers as much functional visual improvement as on eyes without retinal pathology. Methods: This is a retrospective analysis of 4,924 cataract surgeries from the VA Ophthalmic Surgical Outcomes Data Project. We included cases of eyes with AMD which had both preoperative and postoperative NEI-VFQ-25 questionnaires submitted and compared their outcomes to controls without retinal pathology. We excluded patients with other retinal pathologies. The analyses compared changes in visual acuity and overall functional visual improvement and its subscales. Results: Preoperative and postoperative questionnaires were submitted by 58.3% of AMD and 63.8% of controls. Analysis of overall score showed that cataract surgery on eyes with AMD led to increased visual function (13.8± 2.4 NEI-VFQ units, PNEI-VFQ units, PAMD was predictive of postoperative visual function (r=-0.38, PAMD patients with vision of 20/40 or better had overall outcomes similar to controls (-2.2± 4.7 NEI-VFQ units, P=0.37). Conclusions: Cataract surgery on eyes with AMD offers an increase in functional visual improvement; however, the amount of benefit is associated with the eye's preBCVA. For eyes with preBCVA ≥20/40, the improvement is similar to that of patients without retinal pathology. However, if preBCVA is <20/40, the amount of improvement was shown to be significantly less and decreased with decreasing preBCVA.

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. Visualization of probiotic-mediated Ca2+ signaling in intestinal epithelial cells in vivo

    Directory of Open Access Journals (Sweden)

    Takahiro Adachi

    2016-12-01

    Full Text Available Probiotics, such as lactic acid bacteria (LAB and Bacillus subtilis var. natto, have been shown to modulate immune responses. It is important to understand how probiotic bacteria impact intestinal epithelial cells (IECs, because IECs are the first line of defense at the mucosal surface barrier and their activities substantially affect the gut microenvironment and immunity. However, to date, their precise mechanism remains unknown due to a lack of analytical systems available for live animal models. Recently, we generated a conditional Ca2+ biosensor Yellow Cameleon (YC3.60 transgenic mouse line and established 5D (x, y, z, time, and Ca2+ intravital imaging systems of lymphoid tissues including those in Peyer’s patches and bone marrow. In the present study, we further advance our intravital imaging system for intestinal tracts to visualize IEC responses against orally administrated food compounds in real time. Using this system, heat-killed Bacillus subtilis natto, a probiotic TTCC012 strain, is shown to directly induce Ca2+ signaling in IECs in mice housed under specific pathogen-free conditions. In contrast, this activation is not observed in the Lactococcus lactis strain C60; however, when we generate germ-free YC3.60 mice and observe the LAB stimulation of IECs in the absence of gut microbiota, C60 is capable of inducing Ca2+ signaling. This is the first study to successfully visualize the direct effect of probiotics on IECs in live animals. These data strongly suggest that probiotic strains stimulate IECs under physiological conditions, and that their activity is affected by the microenvironment of the small intestine, such as commensal bacteria.

  8. Visualization of Probiotic-Mediated Ca2+ Signaling in Intestinal Epithelial Cells In Vivo

    Science.gov (United States)

    Adachi, Takahiro; Kakuta, Shigeru; Aihara, Yoshiko; Kamiya, Tomonori; Watanabe, Yohei; Osakabe, Naomi; Hazato, Naoki; Miyawaki, Atsushi; Yoshikawa, Soichiro; Usami, Takako; Karasuyama, Hajime; Kimoto-Nira, Hiromi; Hirayama, Kazuhiro; Tsuji, Noriko M.

    2016-01-01

    Probiotics, such as lactic acid bacteria (LAB) and Bacillus subtilis var. natto, have been shown to modulate immune responses. It is important to understand how probiotic bacteria impact intestinal epithelial cells (IECs), because IECs are the first line of defense at the mucosal surface barrier and their activities substantially affect the gut microenvironment and immunity. However, to date, their precise mechanism remains unknown due to a lack of analytical systems available for live animal models. Recently, we generated a conditional Ca2+ biosensor Yellow Cameleon (YC3.60) transgenic mouse line and established 5D (x, y, z, time, and Ca2+) intravital imaging systems of lymphoid tissues including those in Peyer’s patches and bone marrow. In the present study, we further advance our intravital imaging system for intestinal tracts to visualize IEC responses against orally administrated food compounds in real time. Using this system, heat-killed B. subtilis natto, a probiotic TTCC012 strain, is shown to directly induce Ca2+ signaling in IECs in mice housed under specific pathogen-free conditions. In contrast, this activation is not observed in the Lactococcus lactis strain C60; however, when we generate germ-free YC3.60 mice and observe the LAB stimulation of IECs in the absence of gut microbiota, C60 is capable of inducing Ca2+ signaling. This is the first study to successfully visualize the direct effect of probiotics on IECs in live animals. These data strongly suggest that probiotic strains stimulate IECs under physiological conditions and that their activity is affected by the microenvironment of the small intestine, such as commensal bacteria. PMID:28018362

  9. Comparative study on direction selectivity and functional organization of the primary visual cortical cells in monkeys and cats

    Institute of Scientific and Technical Information of China (English)

    寿天德; 周逸峰; 俞洪波

    2000-01-01

    Although the directionally selective cells in many visual cortical areas are organized in columnar manner, the functional organization of direction selectivity of area VI in the monkey still remains unclear. We quantitatively studied the proportion of directionally selective cells, direction selectivity and the functional organization of the striate cortical cells in the monkey and compared those with the cat. The results show that the direction selectivity and directional organization of striate cortical cells in the monkey are significantly weaker than those in the cat, suggesting that the species difference between the two kinds of animal is related to their different anatomic pathways.

  10. Comparative study on direction selectivity and functional organization of the primary visual cortical cells in monkeys and cats

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Although the directionally selective cells in many visual cortical areas are organized in columnar manner, the functional organization of direction selectivity of area Vl in the monkey still remains unclear. We quantitatively studied the proportion of directionally selective cells, direction selectivity and the functional organization of the striate cortical cells in the monkey and compared those with the cat. The results show that the direction selectivity and directional organization of striate cortical cells in the monkey are significantly weaker than those in the cat, suggesting that the species difference between the two kinds of animal is related to their different anatomic pathways.

  11. [Persistence of orientation-selective cells of the primary visual cortex in kittens enucleated unilaterally at birth and reared in darkness].

    Science.gov (United States)

    Fregnac, Y; Buisseret, P; Bienenstock, E; Gary-Bobo, E; Imbert, M

    1978-07-17

    In kittens dark reared (6 weeks old) orientation selective cells are no longer recorded in the primary visual cortex, while in kittens of same age, enucleated at birth unilaterally and reared in identical conditions, 30% of visual cortical cells are shown to be orientation selective and in addition respond preferentially to horizontal and vertical orientations.

  12. Visualization of proteolytic activity associated with the apoptotic response in cancer cells

    Science.gov (United States)

    Tice, Brian George

    Caspases execute programmed cell death, where low levels of caspase activity are linked to cancer. Chemotherapies utilize induction of apoptosis as a key mechanism for cancer treatment, where caspase-3 is a major player involved in dismantling these aberrant cells. The ability to sensitively measure the initial caspase-3 cleavage events during apoptosis is important for understanding the initiation of this complex cellular process, however, current ensemble methods are not sensitive enough to measure single cleavage events in cells. By utilizing the optical properties of plasmon coupling, peptide-linked gold nanoparticles were developed to enable single molecule imaging of caspase-3 activity in two different cancer systems. Au crown nanoparticles were assembled in a multimeric fashion to overcome the high and heterogeneous background scattering of live cells. In a colon cancer (SW620) cell line challenged with tumor necrosis factor-alpha (TNF-alpha), single molecule trajectories show early stage caspase-3 activation within minutes, which was not detectable by ensemble assays until 23 hours. Variability in caspase-3 activation among the population of cells was identified and likely a result of each cell's specific resistance to death receptor-induced apoptosis. Following these studies, improvements by way of sensitivity and selectivity were tailored into an improved nanosensor construct. Au nanoshell dimers were prepared as a comparably bright construct with 1) reduced heterogeneity compared to the synthesis of the crown nanoparticles and 2) a peptide sequence highly selective for caspase-3. Chronic myeloid leukemia (CML) K562 cells were assessed for their early apoptotic response upon treatment with dasatinib, a clinically approved tyrosine kinase inhibitor that specifically targets BCR-ABL. It has been demonstrated that inhibition of BCR-ABL by dasatinib commits K562 cells to apoptosis. Single molecule experiments with Au nanoshell dimers show caspase-3 activation

  13. Current smoking is associated with a poor visual acuity improvement after intravitreal ranibizumab therapy in patients with exudative age-related macular degeneration.

    Science.gov (United States)

    Lee, Sangmoon; Song, Su Jeong; Yu, Hyeong Gon

    2013-05-01

    In this study, the risk factors that may influence visual improvement after intravitreal ranibizumab (IVR) treatment for exudative age-related macular degeneration (AMD) were examined. From 2008 to 2012, 420 patients (448 eyes) with exudative AMD were prospectively registered at Seoul National University Hospital. From this group of patients, 125 eyes were included in this study. All patients were treated with 3 consecutive IVR injections. The visual acuity (VA) was evaluated at baseline and 1 month after the third ranibizumab injection. To evaluate the risk factors associated with VA improvement after IVR, patient demographic data and systemic risk factors were analyzed. Patients were divided into a poor VA improvement group and a good VA improvement group, with reference to the median visual improvement in all eyes. Among 125 eyes, 66 eyes (52.8%) were included in the responder group and 59 eyes (47.2%) in the non-responder group. The median VA improvement after 3 monthly ranibizumab injections was -0.05 logMAR. Multivariate analyses revealed that current smoking (adjusted OR, 7.540; 95% CI, 1.732-32.823) was independently associated with poor VA improvement after IVR treatment for exudative AMD. In conclusion, cigarette smoking is an independent risk factor for lower VA gains with IVR treatment for exudative AMD.

  14. An Assessment of Gadonanotubes as Magnetic Nanolabels for Improved Stem Cell Detection and Retention in Cardiomyoplasty

    Science.gov (United States)

    Tran, Lesa A.

    In this work, gadolinium-based carbon nanocapsules are developed as a novel nanotechnology that addresses the shortcomings of current diagnostic and therapeutic methods of stem cell-based cardiomyoplasty. With cardiovascular disease (CVD) responsible for approximately 30% of deaths worldwide, the growing need for improved cardiomyoplasty has spurred efforts in nanomedicine to develop innovative techniques to enhance the therapeutic retention and diagnostic tracking of transplanted cells. Having previously been demonstrated as a high-performance T1-weighted magnetic resonance imaging (MRI) contrast agent, Gadonanotubes (GNTs) are shown for the first time to intracellularly label pig bone marrow-derived mesenchymal stem cells (MSCs). Without the use of a transfection agent, micromolar concentrations of GNTs deliver up to 109 Gd3+ ions per cell, allowing for MSCs to be visualized in a 1.5 T clinical MRI scanner. The cellular response to the intracellular incorporation of GNTs is also assessed, revealing that GNTs do not compromise the viability, differentiation potential, or phenotype characteristics of the MSCs. However, it is also found that GNT-labeled MSCs exhibit a decreased response to select cell adhesion proteins and experience a nonapoptotic, non-proliferative cell cycle arrest, from which the cells recover 48 h after GNT internalization. In tandem with developing GNTs as a new stem cell diagnostic agent, this current work also explores for the first time the therapeutic application of the magnetically-active GNTs as a magnetic facilitator to increase the retention of transplanted stem cells during cardiomyoplasty. In vitro flow chamber assays, ex vivo perfusion experiments, and in vivo porcine injection procedures all demonstrate the increased magnetic-assisted retention of GNT-labeled MSCs in the presence of an external magnetic field. These studies prove that GNTs are a powerful 'theranostic' agent that provides a novel platform to simultaneously monitor

  15. Improved survival of children and adolescents with sickle cell disease.

    Science.gov (United States)

    Quinn, Charles T; Rogers, Zora R; McCavit, Timothy L; Buchanan, George R

    2010-04-29

    The survival of young children with sickle cell disease (SCD) has improved, but less is known about older children and adolescents. We studied the Dallas Newborn Cohort (DNC) to estimate contemporary 18-year survival for newborns with SCD and document changes in the causes and ages of death over time. We also explored whether improvements in the quality of medical care were temporally associated with survival. The DNC now includes 940 subjects with 8857 patient-years of follow-up. Most children with sickle cell anemia (93.9%) and nearly all children with milder forms of SCD (98.4%) now live to become adults. The incidence of death and the pattern of mortality changed over the duration of the cohort. Sepsis is no longer the leading cause of death. All the recent deaths in the cohort occurred in patients 18 years or older, most shortly after the transition to adult care. Quality of care in the DNC has improved over time, with significantly more timely initial visits and preventive interventions for young children. In summary, most children with SCD now survive the childhood years, but young adults who transition to adult medical care are at high risk for early death.

  16. Ultrastructural visualization of the Mesenchymal-to-Epithelial Transition during reprogramming of human fibroblasts to induced pluripotent stem cells

    Directory of Open Access Journals (Sweden)

    M.K. Høffding

    2015-01-01

    Here, we integrate a panel of morphological approaches with gene expression analyses to visualize the dynamics of episomal reprogramming of human fibroblasts to iPSCs. We provide the first ultrastructural analysis of human fibroblasts at various stages of episomal iPSC reprogramming, as well as the first real-time live cell visualization of a MET occurring during reprogramming. The results indicate that the MET manifests itself approximately 6–12 days after electroporation, in synchrony with the upregulation of early pluripotency markers, and resembles a reversal of the Epithelial-to-Mesenchymal Transition (EMT which takes place during mammalian gastrulation.

  17. 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…

  18. Multisensory teamwork: using a tactile or an auditory display to exchange gaze information improves performance in joint visual search.

    Science.gov (United States)

    Wahn, Basil; Schwandt, Jessika; Krüger, Matti; Crafa, Daina; Nunnendorf, Vanessa; König, Peter

    2016-06-01

    In joint tasks, adjusting to the actions of others is critical for success. For joint visual search tasks, research has shown that when search partners visually receive information about each other's gaze, they use this information to adjust to each other's actions, resulting in faster search performance. The present study used a visual, a tactile and an auditory display, respectively, to provide search partners with information about each other's gaze. Results showed that search partners performed faster when the gaze information was received via a tactile or auditory display in comparison to receiving it via a visual display or receiving no gaze information. Findings demonstrate the effectiveness of tactile and auditory displays for receiving task-relevant information in joint tasks and are applicable to circumstances in which little or no visual information is available or the visual modality is already taxed with a demanding task such as air-traffic control. Practitioner Summary: The present study demonstrates that tactile and auditory displays are effective for receiving information about actions of others in joint tasks. Findings are either applicable to circumstances in which little or no visual information is available or when the visual modality is already taxed with a demanding task.

  19. Aptamer modification improves the adenoviral transduction of malignant glioma cells.

    Science.gov (United States)

    Chen, Hao; Zheng, Xiaojing; Di, BingYan; Wang, Dongyang; Zhang, Yaling; Xia, Haibin; Mao, Qinwen

    2013-12-01

    Adenovirus has shown increasing promise in the gene-viral therapy for glioblastoma, a treatment strategy that relies on the delivery of viruses or transgenes into tumor cells. However, targeting of adenovirus to human glioblastoma remains a challenge due to the low expression level of coxsackie and adenovirus receptor (CAR) in glioma cells. Aptamers are small and highly structured single-stranded oligonucleotides that bind at high affinity to a target molecule, and are good candidates for targeted imaging and therapy. In this study, to construct an aptamer-modified Ad5, we first genetically modified the HVR5 of Ad hexon by biotin acceptor peptide (BAP), which would be metabolically biotinylated during production in HEK293 cells, and then attached the biotin labeled aptamer to the modified Ad through avidin–biotin binding. The aptamers used in this study includes AS1411 and GBI-10. The former is a DNA aptamer that can bind to nucleolin, a nuclear matrix protein found on the surface of cancer cells. The latter is a DNA aptamer that can recognize the extracellular matrix protein tenascin-C on the surface of human glioblastoma cells. To examine if aptamer-modification of the hexon protein could improve the adenoviral transduction efficiency, a glioblastoma cell line, U251, was transduced with aptamer-modified Ads. The transduction efficiency of AS1411- or GBI-10-modified Ad was approximately 4.1-fold or 5.2-fold higher than that of the control. The data indicated that aptamer modified adenovirus would be a useful tool for cancer gene therapy.

  20. Improved Accelerated Stress Tests Based on Fuel Cell Vehicle Data

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, Timothy [Research Engineer; Motupally, Sathya [Research Engineer

    2012-06-01

    UTC will led a top-tier team of industry and national laboratory participants to update and improve DOE’s Accelerated Stress Tests (AST’s) for hydrogen fuel cells. This in-depth investigation will focused on critical fuel cell components (e.g. membrane electrode assemblies - MEA) whose durability represented barriers for widespread commercialization of hydrogen fuel cell technology. UTC had access to MEA materials that had accrued significant load time under real-world conditions in PureMotion® 120 power plant used in transit buses. These materials are referred to as end-of-life (EOL) components in the rest of this document. Advanced characterization techniques were used to evaluate degradation mode progress using these critical cell components extracted from both bus power plants and corresponding materials tested using the DOE AST’s. These techniques were applied to samples at beginning-of-life (BOL) to serve as a baseline. These comparisons advised the progress of the various failure modes that these critical components were subjected to, such as membrane degradation, catalyst support corrosion, platinum group metal dissolution, and others. Gaps in the existing ASTs predicted the degradation observed in the field in terms of these modes were outlined. Using the gaps, new AST’s were recommended and tested to better reflect the degradation modes seen in field operation. Also, BOL components were degraded in a test vehicle at UTC designed to accelerate the bus field operation.

  1. Improved fullerene nanofiber electrodes used in direct methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Q [Nano Craft Technologies Co., Ltd., Tsukuba (Japan); Zhang, Y [Nationals Institute of Advanced Industrial Science and Technology, Tsukuba (Japan); Miyazawa, K; Kato, R; Hotta, K; Wakahara, T [National Institute for Materials Science, Tsukuba (Japan)], E-mail: yi.zhang@aist.go.jp, E-mail: q.wang@aist.go.jp

    2009-04-01

    Platinum supported on fullerene nanofibers as possible electrodes for direct methanol fuel cells (DMFC) were studied. Fullerene nanofiber with 20 wt% Pt loading was mixed with 5 wt% Nafion solution. The mixture paste was coated on Nafion 117 membrane and sandwiched with silicon plates. To increase the surface reaction area of catalyst, nanoimprint was used to fabricate micro-patterns in the Nafion proton exchange membrane. Nanoimprint pattern consisted of dots of 500 nm-in-diameter, 140 nm-in-depth and 1 {mu}m-in-spacing. The nanoimprint of the treated proton exchange membrane (PEM) was carried out in a desktop thermal nanoimprint system (NI273, Nano Craft Tech. Corp., Japan) at the optimized conditions of 130 {sup 0}C and pressure of 3 MPa for 6 min. Then the Pt-coated PEM was sandwiched with micro-channelled silicon plates to form a micro-DMFC. With passively feeding of 1 M methanol solution and air at room temperature, the as-prepared cell had the open circuit voltage of 0.34 V and the maximum power density of 0.30 mW/cm{sup 2}. Compared with a fresh cell, the results shows that nanofibers used in nanoimprinted PEM have an improvement on the performance of micro fuel cells.

  2. [Efficacy of topical ketorolac for improving visual function after photocoagulation in diabetic patients with focal macular edema].

    Science.gov (United States)

    Razo Blanco-Hernández, Dulce Milagros; Lima-Gómez, Virgilio; Asbun-Bojalil, Juan

    2014-01-01

    Antecedentes: la fotocoagulación reduce la incidencia de pérdida visual en diabéticos con edema macular focal, aunque puede inducirla durante 6 semanas; la mejoría visual después del tratamiento es excepcional. El ketorolaco tópico puede limitar la inflamación causada por la fotocoagulación, y mejorar el desenlace visual. Objetivo: determinar la eficacia del ketorolaco tópico en la mejoría de la función visual después de la fotocoagulación, en diabéticos con edema macular focal. Material y métodos: estudio experimental, comparativo, prospectivo, longitudinal efectuado en diabéticos con edema macular focal, asignados al azar a dos grupos de tratamiento tópico durante 3 semanas después de la fotocoagulación (A: ketorolaco, B: placebo). En cada grupo se comparó la agudeza visual antes y después del tratamiento (t pareada) y entre grupos la proporción de ojos con mejoría visual (χ(2)). La evaluación se repitió con estratificación por agudeza visual inicial (≥ 0.5, cambio porcentual fue 22.3% en el grupo A y 3.5% en el B (p= 0.03). Hubo mejoría visual en 25 ojos del grupo A (54.3%) y 19 del B (32.2%, p= 0.019, RR 1.65); la diferencia persistió cuando la agudeza visual inicial era ≥ 0.5 (10 [40%], grupo A, 5 [14.7%], grupo B, p= 0.02, RR 2.72). Conclusiones: el ketorolaco fue más eficaz que el placebo para mejorar la agudeza visual en pacientes diabéticos con edema macular focal.

  3. Glycosaminoglycan mimetic improves enrichment and cell functions of human endothelial progenitor cell colonies.

    Science.gov (United States)

    Chevalier, Fabien; Lavergne, Mélanie; Negroni, Elisa; Ferratge, Ségolène; Carpentier, Gilles; Gilbert-Sirieix, Marie; Siñeriz, Fernando; Uzan, Georges; Albanese, Patricia

    2014-05-01

    Human circulating endothelial progenitor cells isolated from peripheral blood generate in culture cells with features of endothelial cells named late-outgrowth endothelial colony-forming cells (ECFC). In adult blood, ECFC display a constant quantitative and qualitative decline during life span. Even after expansion, it is difficult to reach the cell dose required for cell therapy of vascular diseases, thus limiting the clinical use of these cells. Glycosaminoglycans (GAG) are components from the extracellular matrix (ECM) that are able to interact and potentiate heparin binding growth factor (HBGF) activities. According to these relevant biological properties of GAG, we designed a GAG mimetic having the capacity to increase the yield of ECFC production from blood and to improve functionality of their endothelial outgrowth. We demonstrate that the addition of [OTR(4131)] mimetic during the isolation process of ECFC from Cord Blood induces a 3 fold increase in the number of colonies. Moreover, addition of [OTR(4131)] to cell culture media improves adhesion, proliferation, migration and self-renewal of ECFC. We provide evidence showing that GAG mimetics may have great interest for cell therapy applied to vascular regeneration therapy and represent an alternative to exogenous growth factor treatments to optimize potential therapeutic properties of ECFC.

  4. In vivo visualizing the dynamics of bone marrow stem cells in mouse retina and choroidal-retinal circulation

    Science.gov (United States)

    Wang, Heuy-Ching H.; Zwick, Harry; Edsall, Peter R.; Cheramie, Rachel D.; Lund, David J.; Stuck, Bruce

    2007-02-01

    It has recently been shown that bone marrow cells can differentiate into various lineage cells including neural cells in vitro and in vivo. Therefore it is an attractive therapeutic intervention to apply autologous bone marrow-derived stem cells that may offer neuroprotection to laser-induced retinal injuries. The purpose of this study is to develop a method with which to visualize bone marrow stem cells dynamics in mouse retinal circulation. We have used a physiological method, confocal scanning laser ophthalmoscope (SLO), to track the highly enriched stem/progenitor cells circulating in the retina. Stem cells were enriched by immunomagnetic depletion of cells committed to the T- and B lymphocytic, myeloid and erythorid lineages. CellTracker TM Green-labeled stem cells were injected into the tail veins of mice with laser-induced focal retinal injuries. Bone marrow stem cells labeled with CellTracker TM Green were visible in the retinal circulation for as long as 1 hour and 30 minutes. These studies suggest that stem cell-enriched bone marrow cells may have the ability to mobilize into laser-induced retinal injuries and possibly further proliferate, differentiate and functionally integrate into the retina.

  5. 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).

  6. 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.

  7. Intentional esophageal intubation to improve visualization during emergent endotracheal intubation in the context of massive vomiting: a case report.

    Science.gov (United States)

    Sorour, Khaled; Donovan, Lucas

    2015-03-01

    Impaired visualization during intubation due to vomitus of gastric contents is a potential cause of failed intubation. An 82-year-old woman was intubated emergently for respiratory distress secondary to aspiration of gastric contents. Her intubation was hindered by the presence of a massive amount of ongoing vomitus that impaired visualization and overwhelmed all suction capabilities. Intentional blind intubation of the esophagus with an endotracheal tube was performed with successful diversion of ongoing vomitus away from the airway. Thereafter, after brief suctioning, the larynx was quickly visualized and the patient was successfully intubated.

  8. Visualizing double-stranded RNA distribution and dynamics in living cells by dsRNA binding-dependent fluorescence complementation

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Xiaofei [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3 (Canada); College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang 310036 (China); Deng, Ping; Cui, Hongguang [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3 (Canada); Wang, Aiming, E-mail: aiming.wang@agr.gc.ca [Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario N5V 4T3 (Canada)

    2015-11-15

    Double-stranded RNA (dsRNA) is an important type of RNA that plays essential roles in diverse cellular processes in eukaryotic organisms and a hallmark in infections by positive-sense RNA viruses. Currently, no in vivo technology has been developed for visualizing dsRNA in living cells. Here, we report a dsRNA binding-dependent fluorescence complementation (dRBFC) assay that can be used to efficiently monitor dsRNA distribution and dynamics in vivo. The system consists of two dsRNA-binding proteins, which are fused to the N- and C-terminal halves of the yellow fluorescent protein (YFP). Binding of the two fusion proteins to a common dsRNA brings the split YFP halves in close proximity, leading to the reconstitution of the fluorescence-competent structure and restoration of fluorescence. Using this technique, we were able to visualize the distribution and trafficking of the replicative RNA intermediates of positive-sense RNA viruses in living cells. - Highlights: • A live-cell imaging system was developed for visualizing dsRNA in vivo. • It uses dsRNA binding proteins fused with two halves of a fluorescent protein. • Binding to a common dsRNA enables the reporter to become fluorescent. • The system can efficiently monitor viral RNA replication in living cells.

  9. Distinct representation and distribution of visual information by specific cell types in mouse superficial superior colliculus.

    Science.gov (United States)

    Gale, Samuel D; Murphy, Gabe J

    2014-10-01

    The superficial superior colliculus (sSC) occupies a critical node in the mammalian visual system; it is one of two major retinorecipient areas, receives visual cortical input, and innervates visual thalamocortical circuits. Nonetheless, the contribution of sSC neurons to downstream neural activity and visually guided behavior is unknown and frequently neglected. Here we identified the visual stimuli to which specific classes of sSC neurons respond, the downstream regions they target, and transgenic mice enabling class-specific manipulations. One class responds to small, slowly moving stimuli and projects exclusively to lateral posterior thalamus; another, comprising GABAergic neurons, responds to the sudden appearance or rapid movement of large stimuli and projects to multiple areas, including the lateral geniculate nucleus. A third class exhibits direction-selective responses and targets deeper SC layers. Together, our results show how specific sSC neurons represent and distribute diverse information and enable direct tests of their functional role.

  10. Uniform silica coated fluorescent nanoparticles: synthetic method, improved light stability and application to visualize lymph network tracer.

    Directory of Open Access Journals (Sweden)

    Liman Cong

    Full Text Available BACKGROUND: The sentinel lymph node biopsy (SLNB was developed as a new modality in the surgical diagnosis of lymph node metastases. Dye and radioisotope are major tracers for the detection of sentinel lymph nodes (SLN. Dye tends to excessively infiltrate into the interstitium due to their small size (less than several nanometers, resulting in difficulties in maintaining clear surgical fields. Radioisotopes are available in limited number of hospitals. Fluorescent nanoparticles are good candidates for SLN tracer to solve these problems, as we can choose suitable particle size and fluorescence wavelength of near-infrared. However, the use of nanoparticles faces safety issues, and many attempts have been performed by giving insulating coats on nanoparticles. In addition, the preparation of the uniform insulating layer is important to decrease variations in the quality as an SLN tracer. METHODOLOGY/PRINCIPAL FINDINGS: We herein succeeded in coating fluorescent polystyrene nanoparticles of 40 nm with uniform silica layer of 13 nm by the modified Stöber method. The light stability of silica coated nanoparticles was 1.3-fold greater than noncoated nanoparticles. The popliteal lymph node could be visualized by the silica coated nanoparticles with injection in the rat feet. CONCLUSIONS/SIGNIFICANCE: The silica coated nanoparticles in lymph nodes could be observed by transmission electron microscope, suggesting that our silica coating method is useful as a SLN tracer with highly precise distribution of nanoparticles in histological evaluation. We also demonstrated for the first time that a prolonged enhancement of SLN is caused by the phagocytosis of fluorescent nanoparticles by both macrophages and dendritic cells.

  11. Some know- how to improve properties of Visual FoxPro%改进Visual FoxPro性能的几个技巧

    Institute of Scientific and Technical Information of China (English)

    阴光琰

    2004-01-01

    高性能是Microsoft FoxPro数据库管理系统(特别是它的数据库引擎)的最大特点.Visual FoxPro关系型数据库引进了对象模型,提高了引擎的存取速度并增强了客户/服务器特性,因此整个管理系统的功能变得更加强大.但是,这些强大功能的代价是使管理系统变得更加复杂.因此,一方面,很容易开发出性能稳定、面向对象、使用远程数据的应用程序,另一方面,也很难避免出现低性能的应用程序.

  12. 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

    2014-05-05

    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

  13. A new visually improved and sensitive loop mediated isothermal amplification (LAMP) for diagnosis of symptomatic falciparum malaria.

    Science.gov (United States)

    Mohon, Abu Naser; Elahi, Rubayet; Khan, Wasif A; Haque, Rashidul; Sullivan, David J; Alam, Mohammad Shafiul

    2014-06-01

    Molecular diagnosis of malaria by nucleotide amplification requires sophisticated and expensive instruments, typically found only in well-established laboratories. Loop-mediated isothermal amplification (LAMP) has provided a new platform for an easily adaptable molecular technique for molecular diagnosis of malaria without the use of expensive instruments. A new primer set has been designed targeting the 18S rRNA gene for the detection of Plasmodium falciparum in whole blood samples. The efficacy of LAMP using the new primer set was assessed in this study in comparison to that of a previously described set of LAMP primers as well as with microscopy and real-time PCR as reference methods for detecting P. falciparum. Pre-addition of hydroxy napthol blue (HNB) in the LAMP reaction caused a distinct color change, thereby improving the visual detection system. The new LAMP assay was found to be 99.1% sensitive compared to microscopy and 98.1% when compared to real-time PCR. Meanwhile, its specificity was 99% and 100% in contrast to microscopy and real-time PCR, respectively. Moreover, the LAMP method was in very good agreement with microscopy and real-time PCR (0.94 and 0.98, respectively). This new LAMP method can detect at least 5parasites/μL of infected blood within 35min, while the other LAMP method tested in this study, could detect a minimum of 100parasites/μL of human blood after 60min of amplification. Thus, the new method is sensitive and specific, can be carried out in a very short time, and can substitute PCR in healthcare clinics and standard laboratories.

  14. Development of improved vaccine cell lines against rotavirus

    Science.gov (United States)

    Wu, Weilin; Orr-Burks, Nichole; Karpilow, Jon; Tripp, Ralph A.

    2017-01-01

    Rotavirus is a major cause of severe gastroenteritis among very young children. In developing countries, rotavirus is the major cause of mortality in children under five years old, causing up to 20% of all childhood deaths in countries with high diarrheal disease burden, with more than 90% of these deaths occurring in Africa and Asia. Rotavirus vaccination mimics the first infection without causing illness, thus inducing strong and broad heterotypic immunity against prospective rotavirus infections. Two live vaccines are available, Rotarix and RotaTeq, but vaccination efforts are hampered by high production costs. Here, we present a dataset containing a genome-wide RNA interference (RNAi) screen that identified silencing events that enhanced rotavirus replication. Evaluated against several rotavirus vaccine strains, hits were validated in a Vero vaccine cell line as well as CRISPR/Cas9 generated cells permanently and stably lacking the genes that affect RV replication. Knockout cells were dramatically more permissive to RV replication and permitted an increase in rotavirus replication. These data show a means to improve manufacturing of rotavirus vaccine. PMID:28248921

  15. Energy accumulation and improved performance in microbial fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Ieropoulos, Ioannis; Melhuish, Chris [Intelligent Autonomous Systems Laboratory, CEMS Faculty, University of the West of England, Frenchay Campus, Coldharbour Lane, Bristol BS16 1QY (United Kingdom); Greenman, John [Microbiology Research Laboratory, Applied Sciences Faculty, University of the West of England, Frenchay Campus, Coldharbour Lane, Bristol BS16 1QY (United Kingdom); Hart, John [School of Human and Analytical Sciences, Applied Sciences Faculty, University of the West of England, Frenchay Campus, Coldharbour Lane, Bristol BS16 1QY (United Kingdom)

    2005-08-18

    The mechanisms for electron transfer from the microorganisms found in anaerobic sludge to the anode electrode in microbial fuel cells (MFCs) have been investigated. In doing so, both the energy accumulation and improved performance were observed as a result of the addition of exogenous Na{sub 2}SO{sub 4}. Treatment of anaerobic sludge by centrifugation and washing can provide samples devoid of sulphide/sulphate. Addition of exogenous sulphate can give matched samples of S-deplete and S-replete suspensions. When these are compared in an experimental MFC, the power output of the S-deplete is only 20% that of the S-replete system. Moreover, repeat washing of the anodic chamber to remove suspended cells (leaving only cells attached to the electrode) and addition of buffer substrate gives MFC that produce an output between 10 and 20% that of control. We conclude that anaerobic sludge MFCs are a hybrid incorporating both natural mediator and anodophillic properties. We have also shown that disconnected MFC (open circuit) continue to produce sulphide and when reconnected gives an initial burst of power output demonstrating accumulator-type activity. (author)

  16. 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

    2008-05-21

    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.

  17. Novel proton exchange membrane fuel cell electrodes to improve performance of reversible fuel cell systems

    Science.gov (United States)

    Brown, Tim Matthew

    Proton exchange membrane (PEM) fuel cells react fuel and oxidant to directly and efficiently produce electrical power, without the need for combustion, heat engines, or motor-generators. Additionally, PEM fuel cell systems emit zero to virtually zero criteria pollutants and have the ability to reduce CO2 emissions due to their efficient operation, including the production or processing of fuel. A reversible fuel cell (RFC) is one particular application for a PEM fuel cell. In this application the fuel cell is coupled with an electrolyzer and a hydrogen storage tank to complete a system that can store and release electrical energy. These devices can be highly tailored to specific energy storage applications, potentially surpassing the performance of current and future secondary battery technology. Like all PEM applications, RFCs currently suffer from performance and cost limitations. One approach to address these limitations is to improve the cathode performance by engineering more optimal catalyst layer geometry as compared to the microscopically random structure traditionally used. Ideal configurations are examined and computer modeling shows promising performance improvements are possible. Several novel manufacturing methods are used to build and test small PEM fuel cells with novel electrodes. Additionally, a complete, dynamic model of an RFC system is constructed and the performance is simulated using both traditional and novel cathode structures. This work concludes that PEM fuel cell microstructures can be tailored to optimize performance based on design operating conditions. Computer modeling results indicate that novel electrode microstructures can improve fuel cell performance, while experimental results show similar performance gains that bolster the theoretical predictions. A dynamic system model predicts that novel PEM fuel cell electrode structures may enable RFC systems to be more competitive with traditional energy storage technology options.

  18. Documentation of high impact visualizations and improvement plans for utilization of VisIt for reactor simulation

    Energy Technology Data Exchange (ETDEWEB)

    R.Childs, H; Bremer, D J

    2008-10-03

    The primary goal of this milestone was to enable the visualization and analysis needs of the campaign's simulation codes. This goal was well accomplished. We have extended the VisIt visualization and analysis tool to be suitable for the Nek, UNIC, SAS, and DIABLO code teams. This represented a significant development effort, primarily in terms of tuning the processing of the very large data sets produced by the Nek code. As a result of our development, and of the support we provided, these groups have been able to successfully accomplish their visualization and analysis activities using VisIt. Visualization is an important part of the simulation process. It allows stakeholders to explore simulations and discover phenomena, to confirm assumptions, and to convey findings to a larger audience. Further, visualization software is complex and is an active research area, especially in the area of visualization of very large data sets, such as those produced by the Reactor campaign's Nek code. To meet the campaign's visualization and analysis needs, we chose to leverage the existing software tool, VisIt. VisIt is an open source, parallel visualization and analysis tool for interactively exploring scientific data. The tool represents approximately fifty man-years worth of effort, much of which was dedicated to techniques for processing large data and also to user interfaces. VisIt originated in the DOE's Advanced Simulation and Computing Initiative (ASCI) program, but is also actively developed by the Office of Science's Scientific Discovery through Advanced Computing (SciDAC) program, as well as by the at large open source community, including university partners. Our work for this effort consisted of both customizing VisIt to meet Reactor campaign needs and of providing support for stakeholders in the Reactor campaign to ensure they were successful using the tool.

  19. 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.

  20. Toehold-initiated rolling circle amplification for visualizing individual microRNAs in situ in single cells.

    Science.gov (United States)

    Deng, Ruijie; Tang, Longhua; Tian, Qianqian; Wang, Ying; Lin, Lei; Li, Jinghong

    2014-02-24

    The ability to quantitate and visualize microRNAs (miRNAs) in situ in single cells would greatly facilitate the elucidation of miRNA-mediated regulatory circuits and their disease associations. A toehold-initiated strand-displacement process was used to initiate rolling circle amplification of specific miRNAs, an approach that achieves both stringent recognition and in situ amplification of the target miRNA. This assay, termed toehold-initiated rolling circle amplification (TIRCA), can be utilized to identify miRNAs at physiological temperature with high specificity and to visualize individual miRNAs in situ in single cells within 3 h. TIRCA is a competitive candidate technique for in situ miRNA imaging and may help us to understand the role of miRNAs in cellular processes and human diseases in more detail.

  1. An improved protocol that induces human embryonic stem cells to differentiate into neural cells in vitro.

    Science.gov (United States)

    Zhou, Jun-Mei; Chu, Jian-Xin; Chen, Xue-Jin

    2008-01-01

    Human embryonic stem (ES) cells have the capacity for self-renewal and are able to differentiate into any cell type. However, obtaining high-efficient neural differentiation from human ES cells remains a challenge. This study describes an improved 4-stage protocol to induce a human ES cell line derived from a Chinese population to differentiate into neural cells. At the first stage, embryonic bodies (EBs) were formed in a chemically-defined neural inducing medium rather than in traditional serum or serum-replacement medium. At the second stage, rosette-like structures were formed. At the third stage, the rosette-like structures were manually selected rather than enzymatically digested to form floating neurospheres. At the fourth stage, the neurospheres were further differentiated into neurons. The results show that, at the second stage, the rate of the formation of rosette-like structures from EBs induced by noggin was 88+/-6.32%, higher than that of retinoic acid 55+/-5.27%. Immunocytochemistry staining was used to confirm the neural identity of the cells. These results show a major improvement in obtaining efficient neural differentiation of human ES cells.

  2. Targeted Application of Human Genetic Variation Can Improve Red Blood Cell Production from Stem Cells.

    Science.gov (United States)

    Giani, Felix C; Fiorini, Claudia; Wakabayashi, Aoi; Ludwig, Leif S; Salem, Rany M; Jobaliya, Chintan D; Regan, Stephanie N; Ulirsch, Jacob C; Liang, Ge; Steinberg-Shemer, Orna; Guo, Michael H; Esko, Tõnu; Tong, Wei; Brugnara, Carlo; Hirschhorn, Joel N; Weiss, Mitchell J; Zon, Leonard I; Chou, Stella T; French, Deborah L; Musunuru, Kiran; Sankaran, Vijay G

    2016-01-07

    Multipotent and pluripotent stem cells are potential sources for cell and tissue replacement therapies. For example, stem cell-derived red blood cells (RBCs) are a potential alternative to donated blood, but yield and quality remain a challenge. Here, we show that application of insight from human population genetic studies can enhance RBC production from stem cells. The SH2B3 gene encodes a negative regulator of cytokine signaling and naturally occurring loss-of-function variants in this gene increase RBC counts in vivo. Targeted suppression of SH2B3 in primary human hematopoietic stem and progenitor cells enhanced the maturation and overall yield of in-vitro-derived RBCs. Moreover, inactivation of SH2B3 by CRISPR/Cas9 genome editing in human pluripotent stem cells allowed enhanced erythroid cell expansion with preserved differentiation. Our findings therefore highlight the potential for combining human genome variation studies with genome editing approaches to improve cell and tissue production for regenerative medicine.

  3. PopulationProfiler: A Tool for Population Analysis and Visualization of Image-Based Cell Screening Data.

    Directory of Open Access Journals (Sweden)

    Damian J Matuszewski

    Full Text Available Image-based screening typically produces quantitative measurements of cell appearance. Large-scale screens involving tens of thousands of images, each containing hundreds of cells described by hundreds of measurements, result in overwhelming amounts of data. Reducing per-cell measurements to the averages across the image(s for each treatment leads to loss of potentially valuable information on population variability. We present PopulationProfiler-a new software tool that reduces per-cell measurements to population statistics. The software imports measurements from a simple text file, visualizes population distributions in a compact and comprehensive way, and can create gates for subpopulation classes based on control samples. We validate the tool by showing how PopulationProfiler can be used to analyze the effect of drugs that disturb the cell cycle, and compare the results to those obtained with flow cytometry.

  4. PopulationProfiler: A Tool for Population Analysis and Visualization of Image-Based Cell Screening Data.

    Science.gov (United States)

    Matuszewski, Damian J; Wählby, Carolina; Puigvert, Jordi Carreras; Sintorn, Ida-Maria

    2016-01-01

    Image-based screening typically produces quantitative measurements of cell appearance. Large-scale screens involving tens of thousands of images, each containing hundreds of cells described by hundreds of measurements, result in overwhelming amounts of data. Reducing per-cell measurements to the averages across the image(s) for each treatment leads to loss of potentially valuable information on population variability. We present PopulationProfiler-a new software tool that reduces per-cell measurements to population statistics. The software imports measurements from a simple text file, visualizes population distributions in a compact and comprehensive way, and can create gates for subpopulation classes based on control samples. We validate the tool by showing how PopulationProfiler can be used to analyze the effect of drugs that disturb the cell cycle, and compare the results to those obtained with flow cytometry.

  5. Improved cell-free RNA and protein synthesis system.

    Directory of Open Access Journals (Sweden)

    Jun Li

    Full Text Available Cell-free RNA and protein synthesis (CFPS is becoming increasingly used for protein production as yields increase and costs decrease. Advances in reconstituted CFPS systems such as the Protein synthesis Using Recombinant Elements (PURE system offer new opportunities to tailor the reactions for specialized applications including in vitro protein evolution, protein microarrays, isotopic labeling, and incorporating unnatural amino acids. In this study, using firefly luciferase synthesis as a reporter system, we improved PURE system productivity up to 5 fold by adding or adjusting a variety of factors that affect transcription and translation, including Elongation factors (EF-Ts, EF-Tu, EF-G, and EF4, ribosome recycling factor (RRF, release factors (RF1, RF2, RF3, chaperones (GroEL/ES, BSA and tRNAs. The work provides a more efficient defined in vitro transcription and translation system and a deeper understanding of the factors that limit the whole system efficiency.

  6. Organic photovoltaic cells: from performance improvement to manufacturing processes.

    Science.gov (United States)

    Youn, Hongseok; Park, Hui Joon; Guo, L Jay

    2015-05-20

    Organic photovoltaics (OPVs) have been pursued as a next generation power source due to their light weight, thin, flexible, and simple fabrication advantages. Improvements in OPV efficiency have attracted great attention in the past decade. Because the functional layers in OPVs can be dissolved in common solvents, they can be manufactured by eco-friendly and scalable printing or coating technologies. In this review article, the focus is on recent efforts to control nanomorphologies of photoactive layer and discussion of various solution-processed charge transport and extraction materials, to maximize the performance of OPV cells. Next, recent works on printing and coating technologies for OPVs to realize solution processing are reviewed. The review concludes with a discussion of recent advances in the development of non-traditional lamination and transfer method towards highly efficient and fully solution-processed OPV.

  7. In-situ visualization of N2 evolution in operating direct hydrazine hydrate fuel cell by soft X-ray radiography

    Science.gov (United States)

    Sakamoto, Tomokazu; Deevanhxay, Phengxay; Asazawa, Koichiro; Tsushima, Shohji; Hirai, Shuichiro; Tanaka, Hirohisa

    2014-04-01

    Soft X-ray radiography technique was firstly applied to operating direct hydrazine hydrate fuel cell (DHFCs) in order to visualize N2 gas behaviors with high spatial and temporal resolution. Two different cells for in-situ visualization of N2 gas in the DHFCs in in-plane and through-plane direction were designed and fabricated. The utilization of soft X-ray made the visualization of generated N2 behavior in the DHFC possible with the spatial resolution of 1.5 μm and the temporal resolution of 2.0 s frame-1. In the in-plane visualization, the inhomogeneous N2 gas distribution, suggesting non-uniform reaction distribution in the anode of DHFC, was observed. In the through-plane visualization, N2 gas accumulation under the rib of anode and discharge to the channel was clearly observed, which are related with cell performance instability.

  8. A Comparitive Analysis of Improved 6t Sram Cell With Different Sram Cell

    Directory of Open Access Journals (Sweden)

    Aastha Singh

    2015-04-01

    Full Text Available High speed and low power consumption have been the primary issue to design Static Random Access Memory (SRAM, but we are facing new challenges with the scaling of technology. The stability and speed of SRAM are important issues to improve efficiency and performance of the system. Stability of the SRAM depends on the static noise margin (SNM so the noise margin is also important parameter for the design of memory because the higher noise margin confirms the high speed of the SRAM cell. In this paper, the improved 6T SRAM cell shows maximum reduction in power consumption of 88%, maximum reduction in delay of 64% and maximum SNM of 17% increases compared with 7T SRAM cell.

  9. A Comparison of Pain Assessment Measures in Pediatric Sickle Cell Disease: Visual Analog Scale Versus Numeric Rating Scale.

    Science.gov (United States)

    Myrvik, Matthew P; Drendel, Amy L; Brandow, Amanda M; Yan, Ke; Hoffmann, Raymond G; Panepinto, Julie A

    2015-04-01

    Given the availability of various pain severity scales, greater understanding of the agreement between pain scales is warranted. We compared Visual Analog Scale (VAS) and Numeric Rating Scale (NRS) pain severity ratings in children with sickle cell disease (SCD) to identify the relationship and agreement between pain scale ratings. Twenty-eight patients (mean ± SD age, 14.65 ± 3.12 y, 50% female) receiving pain interventions within the emergency department completed serial VAS and NRS pain severity ratings every 30 minutes. Data were used to calculate the relationship (Spearman correlation) and agreement (Bland-Altman approach) between the VAS and NRS. One hundred twenty-eight paired VAS-NRS measurements were obtained. VAS and NRS ratings were significantly correlated for the initial assessment (rs = 0.88, P < 0.001) and all assessments (rs = 0.87, P < 0.001). Differences between VAS and NRS means were -0.52 (P = 0.006) for the initial assessment and -0.86 (P < 0.001) across all assessments. The difference between VAS and NRS ratings decreased as pain severity increased across all assessments (P = 0.027), but not the initial assessment. Within pediatric patients with SCD, VAS and NRS ratings were found to trend together; however, VAS scores were found to be significantly lower than NRS scores across assessments. The agreement between the 2 measures improved at increasing levels of pain severity. These findings demonstrate that the VAS and NRS are similar, but cannot be used interchangeably when assessing self-reported pain in SCD.

  10. 基于改进视觉字典模型的图像检索算法%Image retrieval algorithm based on improved visual dictionary model

    Institute of Scientific and Technical Information of China (English)

    李强; 左欣; 沈继锋; 徐云凯; 宋颖

    2014-01-01

    In the current research field of image searching, due to the good performance, visual vocabulary has currently become the mainstream method for creating visual dictionaries. The traditional method based on visual vocabulary has the disadvantages of low efficiency, high memory consumption and so on. Thus, the system in this paper utilizes the ROOTSift algorithm to extract feature points in images and adopts the efficient k-means cluster algorithm to create random visual vocabulary which can be expanded dynamically. While there are some open problems in current image searching system, such as the problems of ambiguity and synonymity in visual vocabulary, object positioning and detection performance with big data, this system creates the visual vocabulary histogram and index files with reverse order based on visual vocabulary and reallocates the weights to visual vocabulary to improve the hit ratio of detection. Finally, the similarity matching is achieved through Euclidean distance searching.The experiments show that this method can increase the success rate of image searching and improve the efficiency of the searching ,and it can achieve a nice retrieval quality of the image searching.%目前在图像检索领域,由于视觉字典其性能突出,已成为图像检索领域构建视觉词典的主流方法。但传统的视觉字典方法存在运行时间效率低、内存消耗大等缺点。因此本文采用ROOTSift算法提取图像的特征点并利用高效的K-means聚类算法建立支持动态扩充的随机视觉字典。该方法基于视觉字典构建视觉词汇直方图和倒排序索引文件,并对视觉词重新分配权重以提高检索命中率。最后利用欧氏距离法查询完成相似性匹配。试验结果表明该方法能提高图像检索的准确率,对大规模的图像检索能够达到很好的检索质量。

  11. Modeling solar cells: A method for improving their efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Morales-Acevedo, Arturo, E-mail: amorales@solar.cinvestav.mx [Centro de Investigacion y de Estudios Avanzados del IPN, Electrical Engineering Department, Avenida IPN No. 2508, 07360 Mexico, D.F. (Mexico); Hernandez-Como, Norberto; Casados-Cruz, Gaspar [Centro de Investigacion y de Estudios Avanzados del IPN, Electrical Engineering Department, Avenida IPN No. 2508, 07360 Mexico, D.F. (Mexico)

    2012-09-20

    After a brief discussion on the theoretical basis for simulating solar cells and the available programs for doing this we proceed to discuss two examples that show the importance of doing numerical simulation of solar cells. We shall concentrate in silicon Heterojunction Intrinsic Thin film aSi/cSi (HIT) and CdS/CuInGaSe{sub 2} (CIGS) solar cells. In the first case, we will show that numerical simulation indicates that there is an optimum transparent conducting oxide (TCO) to be used in contact with the p-type aSi:H emitter layer although many experimental researchers might think that the results can be similar without regard of the TCO film used. In this case, it is shown that high work function TCO materials such as ZnO:Al are much better than smaller work function films such as ITO. HIT solar cells made with small work function TCO layers (<4.8 eV) will never be able to reach the high efficiencies already reported experimentally. It will also be discussed that simulations of CIGS solar cells by different groups predict efficiencies around 18-19% or even less, i.e. below the record efficiency reported experimentally (20.3%). In addition, the experimental band-gap which is optimum in this case is around 1.2 eV while several theoretical results predict a higher optimum band-gap (1.4-1.5 eV). This means that there are other effects not included in most of the simulation models developed until today. One of them is the possible presence of an interfacial (inversion) layer between CdS and CIGS. It is shown that this inversion layer might explain the smaller observed optimum band-gap, but some efficiency is lost. It is discussed that another possible explanation for the higher experimental efficiency is the possible variation of Ga concentration in the CIGS film causing a gradual variation of the band-gap. This band-gap grading might help improve the open-circuit voltage and, if it is appropriately done, it can also cause the enhancement of the photo-current density.

  12. Haploinsufficiency of EHMT1 improves pattern separation and increases hippocampal cell proliferation

    Science.gov (United States)

    Benevento, Marco; Oomen, Charlotte A.; Horner, Alexa E.; Amiri, Houshang; Jacobs, Tessa; Pauwels, Charlotte; Frega, Monica; Kleefstra, Tjitske; Kopanitsa, Maksym V.; Grant, Seth G. N.; Bussey, Timothy J.; Saksida, Lisa M.; Van der Zee, Catharina E.E.M.; van Bokhoven, Hans; Glennon, Jeffrey C.; Kasri, Nael Nadif

    2017-01-01

    Heterozygous mutations or deletions of the human Euchromatin Histone Methyltransferase 1 (EHMT1) gene are the main causes of Kleefstra syndrome, a neurodevelopmental disorder that is characterized by impaired memory, autistic features and mostly severe intellectual disability. Previously, Ehmt1+/− heterozygous knockout mice were found to exhibit cranial abnormalities and decreased sociability, phenotypes similar to those observed in Kleefstra syndrome patients. In addition, Ehmt1+/− knockout mice were impaired at fear extinction and novel- and spatial object recognition. In this study, Ehmt1+/− and wild-type mice were tested on several cognitive tests in a touchscreen-equipped operant chamber to further investigate the nature of learning and memory changes. Performance of Ehmt1+/− mice in the Visual Discrimination & Reversal learning, object-location Paired-Associates learning- and Extinction learning tasks was found to be unimpaired. Remarkably, Ehmt1+/− mice showed enhanced performance on the Location Discrimination test of pattern separation. In line with improved Location Discrimination ability, an increase in BrdU-labelled cells in the subgranular zone of the dentate gyrus was observed. In conclusion, reduced levels of EHMT1 protein in Ehmt1+/− mice does not result in general learning deficits in a touchscreen-based battery, but leads to increased adult cell proliferation in the hippocampus and enhanced pattern separation ability. PMID:28071689

  13. Compact Flyeye concentrator with improved irradiance uniformity on solar cell

    Science.gov (United States)

    Zhuang, Zhenfeng; Yu, Feihong

    2013-08-01

    A Flyeye concentrator with improved irradiance distribution on the solar cell in a concentrator photovoltaic system is proposed. This Flyeye concentrator is composed of four surfaces: a refractive surface, mirror surface, freeform surface, and transmissive surface. Based on the principles of geometrical optics, the contours of the proposed Flyeye concentrator are calculated according to Fermat's principle, the edge-ray principle, and the ray reversibility principle without solving partial differential equations or using an optimization algorithm, therefore a slope angle control method is used to construct the freeform surface. The solid model is established by applying a symmetry of revolution around the optical axis. Additionally, the optical performance for the Flyeye concentrator is simulated and analyzed by Monte-Carlo method. Results show that the Flyeye concentrator optical efficiency of >96.2% is achievable with 1333× concentration ratio and ±1.3 deg acceptance angle, and 1.3 low aspect ratio (average thickness to entry aperture diameter ratio). Moreover, comparing the Flyeye concentrator specification to that of the Köhler concentrator and the traditional Fresnel-type concentrator, results indicate that this concentrator has the advantages of improved uniformity, reduced thickness, and increased tolerance to the incident sunlight.

  14. Cell Line Data Base: structure and recent improvements towards molecular authentication of human cell lines.

    Science.gov (United States)

    Romano, Paolo; Manniello, Assunta; Aresu, Ottavia; Armento, Massimiliano; Cesaro, Michela; Parodi, Barbara

    2009-01-01

    The Cell Line Data Base (CLDB) is a well-known reference information source on human and animal cell lines including information on more than 6000 cell lines. Main biological features are coded according to controlled vocabularies derived from international lists and taxonomies. HyperCLDB (http://bioinformatics.istge.it/hypercldb/) is a hypertext version of CLDB that improves data accessibility by also allowing information retrieval through web spiders. Access to HyperCLDB is provided through indexes of biological characteristics and navigation in the hypertext is granted by many internal links. HyperCLDB also includes links to external resources. Recently, an interest was raised for a reference nomenclature for cell lines and CLDB was seen as an authoritative system. Furthermore, to overcome the cell line misidentification problem, molecular authentication methods, such as fingerprinting, single-locus short tandem repeat (STR) profile and single nucleotide polymorphisms validation, were proposed. Since this data is distributed, a reference portal on authentication of human cell lines is needed. We present here the architecture and contents of CLDB, its recent enhancements and perspectives. We also present a new related database, the Cell Line Integrated Molecular Authentication (CLIMA) database (http://bioinformatics.istge.it/clima/), that allows to link authentication data to actual cell lines.

  15. Direct visualization of endogenous Salmonella-specific B cells reveals a marked delay in clonal expansion and germinal center development.

    Science.gov (United States)

    Nanton, Minelva R; Lee, Seung-Joo; Atif, Shaikh M; Nuccio, Sean-Paul; Taylor, Justin J; Bäumler, Andreas J; Way, Sing Sing; McSorley, Stephen J

    2015-02-01

    CD4(+) T cells and B cells are both essential for acquired immunity to Salmonella infection. It is well established that Salmonella inhibit host CD4(+) T-cell responses, but a corresponding inhibitory effect on B cells is less well defined. Here, we utilize an Ag tetramer and pull-down enrichment strategy to directly visualize OVA-specific B cells in mice, as they respond to infection with Salmonella-OVA. Surprisingly, OVA-specific B-cell expansion and germinal center formation was not detected until bacteria were cleared from the host. Furthermore, Salmonella infection also actively inhibited both B- and T-cell responses to the same coinjected Ag but this did not require the presence of iNOS. The Salmonella Pathogenicity Island 2 (SPI2) locus has been shown to be responsible for inhibition of Salmonella-specific CD4(+) T-cell responses, and an examination of SPI2-deficient bacteria demonstrated a recovery in B-cell expansion in infected mice. Together, these data suggest that Salmonella can simultaneously inhibit host B- and T-cell responses using SPI2-dependent mechanisms.

  16. 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 FISH can facilitate the study of a wide variety of extrachromosomal DNA in mammalian cells.

  17. 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, Paulo S. M.; Noltie, Douglas 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.

  18. 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)

  19. Direct visualization of secretion from single bovine adrenal chromaffin cells by laser-induced native fluorescence imaging microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tong, W.; Yeung, E.S. [Ames Laboratory---USDOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011 (United States)

    1998-03-01

    Direct visualization of the secretion process of individual bovine adrenal chromaffin cells was achieved with laser-induced native fluorescence imaging microscopy. By monitoring the native fluorescence of catecholamines excited by the 275 nm laser line with an intensified charge-coupled-device (CCD) camera, we obtained good temporal and spatial resolution simultaneously without using additional fluorescent probes. Large variations were found among individual cells in terms of the amounts of catecholamines secreted and the rates of secretion. Different regions of a cell also behave differently during the secretion process. However, the degree of this local heterogeneity is smaller than in neurons and neuralgia. The influence of deep-ultraviolet (UV) laser excitation on cells is also discussed. This quantitative imaging technique provides a useful noninvasive approach for the study of dynamic cellular changes and the understanding of the molecular mechanisms of secretory processes. {copyright} {ital 1998} {ital Society for Applied Spectroscopy}

  20. 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…

  1. Visualization of molecular composition and functionality of cancer cells using nanoparticle-augmented ultrasound-guided photoacoustics

    Science.gov (United States)

    Mallidi, Srivalleesha; Kim, Seungsoo; Karpiouk, Andrei; Joshi, Pratixa P.; Sokolov, Konstantin; Emelianov, Stanislav

    2015-01-01

    Assessment of molecular signatures of tumors in addition to their anatomy and morphology is desired for effective diagnostic and therapeutic procedures. Development of in vivo imaging techniques that can identify and monitor molecular composition of tumors remains an important challenge in pre-clinical research and medical practice. Here we present a molecular photoacoustic imaging technique that can visualize the presence and activity of an important cancer biomarker – epidermal growth factor receptor (EGFR), utilizing the effect of plasmon resonance coupling between molecular targeted gold nanoparticles. Specifically, spectral analysis of photoacoustic images revealed profound changes in the optical absorption of systemically delivered EGFR-targeted gold nanospheres due to their molecular interactions with tumor cells overexpressing EGFR. In contrast, no changes in optical properties and, therefore, photoacoustic signal, were observed after systemic delivery of non-targeted gold nanoparticles to the tumors. The results indicate that multi-wavelength photoacoustic imaging augmented with molecularly targeted gold nanoparticles has the ability to monitor molecular specific interactions between nanoparticles and cell-surface receptors, allowing visualization of the presence and functional activity of tumor cells. Furthermore, the approach can be used for other cancer cell-surface receptors such as human epidermal growth factor receptor 2 (HER2). Therefore, ultrasound-guided molecular photoacoustic imaging can potentially aid in tumor diagnosis, selection of customized patient-specific treatment, and monitor the therapeutic progression and outcome in vivo. PMID:25893171

  2. Visual selection and maintenance of the cell lines with high plant regeneration ability and low ploidy level in Dianthus acicularis by monitoring with flow cytometry analysis.

    Science.gov (United States)

    Shiba, Tomonori; Mii, Masahiro

    2005-12-01

    Efficient plant regeneration system from cell suspension cultures was established in D. acicularis (2n=90) by monitoring ploidy level and visual selection of the cultures. The ploidy level of the cell cultures closely related to the shoot regeneration ability. The cell lines comprising original ploidy levels (2C+4C cells corresponding to DNA contents of G1 and G2 cells of diploid plant, respectively) showed high regeneration ability, whereas those containing the cells with 8C or higher DNA C-values showed low or no regeneration ability. The highly regenerable cell lines thus selected consisted of compact cell clumps with yellowish color and relatively moderate growth, suggesting that it is possible to select visually the highly regenerable cell lines with the original ploidy level. All the regenerated plantlets from the highly regenerable cell cultures exhibited normal phenotypes and no variations in ploidy level were observed by flow cytometry (FCM) analysis.

  3. Three dimensional visualization and fractal analysis of mosaic patches in rat chimeras: cell assortment in liver, adrenal cortex and cornea.

    Science.gov (United States)

    Iannaccone, Stephen; Zhou, Yue; Walterhouse, David; Taborn, Greg; Landini, Gabriel; Iannaccone, Philip

    2012-01-01

    The production of organ parenchyma in a rapid and reproducible manner is critical to normal development. In chimeras produced by the combination of genetically distinguishable tissues, mosaic patterns of cells derived from the combined genotypes can be visualized. These patterns comprise patches of contiguously similar genotypes and are different in different organs but similar in a given organ from individual to individual. Thus, the processes that produce the patterns are regulated and conserved. We have previously established that mosaic patches in multiple tissues are fractal, consistent with an iterative, recursive growth model with simple stereotypical division rules. Fractal dimensions of various tissues are consistent with algorithmic models in which changing a single variable (e.g. daughter cell placement after division) switches the mosaic pattern from islands to stripes of cells. Here we show that the spiral pattern previously observed in mouse cornea can also be visualized in rat chimeras. While it is generally held that the pattern is induced by stem cell division dynamics, there is an unexplained discrepancy in the speed of cellular migration and the emergence of the pattern. We demonstrate in chimeric rat corneas both island and striped patterns exist depending on the age of the animal. The patches that comprise the pattern are fractal, and the fractal dimension changes with the age of the animal and indicates the constraint in patch complexity as the spiral pattern emerges. The spiral patterns are consistent with a loxodrome. Such data are likely to be relevant to growth and cell division in organ systems and will help in understanding how organ parenchyma are generated and maintained from multipotent stem cell populations located in specific topographical locations within the organ. Ultimately, understanding algorithmic growth is likely to be essential in achieving organ regeneration in vivo or in vitro from stem cell populations.

  4. Three dimensional visualization and fractal analysis of mosaic patches in rat chimeras: cell assortment in liver, adrenal cortex and cornea.

    Directory of Open Access Journals (Sweden)

    Stephen Iannaccone

    Full Text Available The production of organ parenchyma in a rapid and reproducible manner is critical to normal development. In chimeras produced by the combination of genetically distinguishable tissues, mosaic patterns of cells derived from the combined genotypes can be visualized. These patterns comprise patches of contiguously similar genotypes and are different in different organs but similar in a given organ from individual to individual. Thus, the processes that produce the patterns are regulated and conserved. We have previously established that mosaic patches in multiple tissues are fractal, consistent with an iterative, recursive growth model with simple stereotypical division rules. Fractal dimensions of various tissues are consistent with algorithmic models in which changing a single variable (e.g. daughter cell placement after division switches the mosaic pattern from islands to stripes of cells. Here we show that the spiral pattern previously observed in mouse cornea can also be visualized in rat chimeras. While it is generally held that the pattern is induced by stem cell division dynamics, there is an unexplained discrepancy in the speed of cellular migration and the emergence of the pattern. We demonstrate in chimeric rat corneas both island and striped patterns exist depending on the age of the animal. The patches that comprise the pattern are fractal, and the fractal dimension changes with the age of the animal and indicates the constraint in patch complexity as the spiral pattern emerges. The spiral patterns are consistent with a loxodrome. Such data are likely to be relevant to growth and cell division in organ systems and will help in understanding how organ parenchyma are generated and maintained from multipotent stem cell populations located in specific topographical locations within the organ. Ultimately, understanding algorithmic growth is likely to be essential in achieving organ regeneration in vivo or in vitro from stem cell populations.

  5. 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.

  6. An improved alkaline direct formate paper microfluidic fuel cell.

    Science.gov (United States)

    Galvan, Vicente; Domalaon, Kryls; Tang, Catherine; Sotez, Samantha; Mendez, Alex; Jalali-Heravi, Mehdi; Purohit, Krutarth; Pham, Linda; Haan, John; Gomez, Frank A

    2016-02-01

    Paper-based microfluidic fuel cells (MFCs) are a potential replacement for traditional FCs and batteries due to their low cost, portability, and simplicity to operate. In MFCs, separate solutions of fuel and oxidant migrate through paper due to capillary action and laminar flow and, upon contact with each other and catalyst, produce electricity. In the present work, we describe an improved microfluidic paper-based direct formate FC (DFFC) employing formate and hydrogen peroxide as the anode fuel and cathode oxidant, respectively. The dimensions of the lateral column, current collectors, and cathode were optimized. A maximum power density of 2.53 mW/cm(2) was achieved with a DFFC of surface area 3.0 cm(2) , steel mesh as current collector, 5% carbon to paint mass ratio for cathode electrode and, 30% hydrogen peroxide. The longevity of the MFC's detailed herein is greater than eight hours with continuous flow of streams. In a series configuration, the MFCs generate sufficient energy to power light-emitting diodes and a handheld calculator.

  7. Homing and migration of mesenchymal stromal cells: How to improve the efficacy of cell therapy?

    Institute of Scientific and Technical Information of China (English)

    Ann; De; Becker; Ivan; Van; Riet

    2016-01-01

    Mesenchymal stromal cells(MSCs) are currently being investigated for use in a wide variety of clinical applications. For most of these applications, systemic delivery of the cells is preferred. However, this requires the homing and migration of MSCs to a target tissue. Although MSC hominghas been described, this process does not appear to be highly efficacious because only a few cells reach the target tissue and remain there after systemic administration. This has been ascribed to low expression levels of homing molecules, the loss of expression of such molecules during expansion, and the heterogeneity of MSCs in cultures and MSC culture protocols. To overcome these limitations, different methods to improve the homing capacity of MSCs have been examined. Here, we review the current understanding of MSC homing, with a particular focus on homing to bone marrow. In addition, we summarize the strategies that have been developed to improve this process. A better understanding of MSC biology, MSC migration and homing mechanisms will allow us to prepare MSCs with optimal homing capacities. The efficacy of therapeutic applications is dependent on efficient delivery of the cells and can, therefore, only benefit from better insights into the homing mechanisms.

  8. In vivo visualization and monitoring of viable neural stem cells using noninvasive bioluminescence imaging in the 6-hydroxydopamine-induced mouse model of Parkinson disease.

    Science.gov (United States)

    Im, Hyung-Jun; Hwang, Do Won; Lee, Han Kyu; Jang, Jaeho; Lee, Song; Youn, Hyewon; Jin, Yeona; Kim, Seung U; Kim, E Edmund; Kim, Yong Sik; Lee, Dong Soo

    2013-06-01

    Transplantation of neural stem cells (NSCs) has been proposed as a treatment for Parkinson disease (PD). The aim of this study was to monitor the viability of transplanted NSCs expressing the enhanced luciferase gene in a mouse model of PD in vivo. The PD animal model was induced by unilateral injection of 6-hydroxydopamine (6-OHDA). The behavioral test using apomorphine-induced rotation and positron emission tomography with [18F]N-(3-fluoropropyl)-2'-carbomethoxy-3'-(4-iodophenyl)nortropane ([18F]FP-CIT) were conducted. HB1.F3 cells transduced with an enhanced firefly luciferase retroviral vector (F3-effLuc cells) were transplanted into the right striatum. In vivo bioluminescence imaging was repeated for 2 weeks. Four weeks after transplantation, [18F]FP-CIT PET and the rotation test were repeated. All 6-OHDA-injected mice showed markedly decreased [18F]FP-CIT uptake in the right striatum. Transplanted F3-effLuc cells were visualized on the right side of the brain in all mice by bioluminescence imaging. The bioluminescence intensity of the transplanted F3-effLuc cells gradually decreased until it was undetectable by 10 days. The behavioral test showed that stem cell transplantation attenuated the motor symptoms of PD. No significant change was found in [18F]FP-CIT imaging after cell transplantation. We successfully established an in vivo bioluminescence imaging system for the detection of transplanted NSCs in a mouse model of PD. NSC transplantation induced behavioral improvement in PD model mice.

  9. 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;

    2015-01-01

    ESC colony, and prepare 3-5 μm thick serial sections. Immunohistochemistry applied to individual sections produces a 2-dimensional survey of the developing hESC colony. Based on serial paraffin sections of the 2D-expression pattern, a new and useful 3D-visualization can be modeled. The actual 3D rendering......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 derivatives of the three germ layers show the differentiating potential. Studies suggest a certain microheterogeneity of the hESC colonies, in which not all cells in one colony of apparently undifferentiated cells express all the expected markers. We describe a technique to paraffin embed an entire h...

  10. Improvement of warehouse information management based on visual optimization%基于可视化的仓储信息管理系统优化探讨

    Institute of Scientific and Technical Information of China (English)

    陈汐

    2014-01-01

    利用各种可视化技术对仓储信息管理系统进行优化再造,提出信息管理系统效率化改善的工具和方法,在虚拟环境下实现实际作业的三维动画演示,构建直观化的智能仓储信息管理系统。%Use a variety of visualization technology to optimize warehouse management information system reengineering, information management system to improve efficiency of tools and methods, in the virtual environment to realize the actual operation of the three dimensional animation demo, build visualizations of intelligent warehouse management information system.

  11. Clathrin-mediated endocytosis in living host cells visualized through quantum dot labeling of infectious hematopoietic necrosis virus.

    Science.gov (United States)

    Liu, Haibin; Liu, Yi; Liu, Shulin; Pang, Dai-Wen; Xiao, Gengfu

    2011-07-01

    Infectious hematopoietic necrosis virus (IHNV) is an important fish pathogen that infects both wild and cultured salmonids. As a species of the genus Novirhabdovirus, IHNV is a valuable model system for exploring the host entry mechanisms of rhabdoviruses. In this study, quantum dots (QDs) were used as fluorescent labels for sensitive, long-term tracking of IHNV entry. Using live-cell fluorescence microscopy, we found that IHNV is internalized through clathrin-coated pits after the virus binds to host cell membranes. Pretreatment of host cells with chlorpromazine, a drug that blocks clathrin-mediated endocytosis, and clathrin light chain (LCa) depletion using RNA interference both resulted in a marked reduction in viral entry. We also visualized transport of the virus via the cytoskeleton (i.e., actin filaments and microtubules) in real time. Actin polymerization is involved in the transport of endocytic vesicles into the cytosol, whereas microtubules are required for the trafficking of clathrin-coated vesicles to early endosomes, late endosomes, and lysosomes. Disrupting the host cell cytoskeleton with cytochalasin D or nocodazole significantly impaired IHNV infectivity. Furthermore, infection was significantly affected by pretreating the host cells with bafilomycin A1, a compound that inhibits the acidification of endosomes and lysosomes. Strong colocalizations of IHNV with endosomes indicated that the virus is internalized into these membrane-bound compartments. This is the first report in which QD labeling is used to visualize the dynamic interactions between viruses and endocytic structures; the results presented demonstrate that IHNV enters host cells via clathrin-mediated endocytic, cytoskeleton-dependent, and low-pH-dependent pathways.

  12. Bioluminescence-based visualization of CD4 T cell dynamics using a T lineage-specific luciferase transgenic model1

    Directory of Open Access Journals (Sweden)

    Zinn Kurt R

    2009-08-01

    Full Text Available Abstract Background Rapid clonal expansion of T cells occurs in response to antigenic challenges. The kinetics of the T cell response has previously been described using tissue-based studies performed at defined time points. Luciferase bioluminescence has recently been utilized for non-invasive analysis of in vivo biologic processes in real-time. Results We have created a novel transgenic mouse model (T-Lux using a human CD2 mini-gene to direct luciferase expression specifically to the T cell compartment. T-Lux T cells demonstrated normal homing patterns within the intact mouse and following adoptive transfer. Bioluminescent signal correlated with T cell numbers in the whole body images as well as within specific organ regions of interest. Following transfer into lymphopenic (RAG2-/- recipients, homeostatic proliferation of T-Lux T cells was visualized using bioluminescent imaging. Real-time bioluminescent analysis of CD4+ T cell antigen-specific responses enabled real-time comparison of the kinetics and magnitude of clonal expansion and contraction in the inductive lymph node and tissue site of antigen injection. T cell expansion was dose-dependent despite the presence of supraphysiologic numbers of OVA-specific OT-II transgenic TCR T-Lux T cells. CD4+ T cells subsequently underwent a rapid (3–4 day contraction phase in the draining lymph node, with a delayed contraction in the antigen delivery site, with bioluminescent signal diminished below initial levels, representing TCR clonal frequency control. Conclusion The T-Lux mouse provides a novel, efficient model for tracking in vivo aspects of the CD4+ T cell response to antigen, providing an attractive approach for studies directed at immunotherapy or vaccine design.

  13. Coding for stimulus velocity by temporal patterning of spike discharges in visual cells of cat superior colliculus.

    Science.gov (United States)

    Mandl, G

    1993-07-01

    Statistical analyses, performed on extracellularly recorded spike trains generated by 69 single motion sensitive visual cells in the intermediate layers of superior colliculi of pretrigeminal cat preparations, revealed that--even in the unstimulated condition (38/69)--most neuronal spike discharge patterns tended to switch between two stochastically distinct states, in the form of rapidly alternating "bursting" (high frequency) and "resting" (low frequency) episodes. The numbers of consecutive interspike intervals within a given state were, as a rule, independent integer-valued random variables with discrete probability distributions, in essential agreement with the semi-Markov model proposed by Ekholm and Hyvärinen [(1970) Biophysical Journal, 10, 773-796]. The introduction of visual stimuli (47/69) moving with velocities of 2-160 deg/sec caused systematic and reproducible changes in the ratio of bursting to resting activities, decreases in overall discharge variability, and increases in signal transinformation flow. Moreover, with one group of stimulated cells (28/47), increasing stimulus velocity caused increasingly precise ("stimulus-forced") synchronization of bursting episodes with specific phases of stimulus movement; while for a smaller group (12/47), stimulus-related alternations between bursting and resting states assumed the form of semi-rhythmical burst discharges within the characteristic 60-80 Hz "gamma oscillation" range ("stimulus-induced" synchronization). For a minority of cells (7/47), switching between bursting and resting states--although characteristically modified by stimulus velocity--remained largely desynchronized with all phases of stimulus transit. It was argued that such temporal patterns of discharge may constitute elements of a candidate "distribution" code for movement detection by the cat visual system.

  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. How a (subcellular coincidence detection mechanism featuring layer-5 pyramidal cells may help produce various visual phenomena

    Directory of Open Access Journals (Sweden)

    Talis eBachmann

    2015-12-01

    Full Text Available Perceptual phenomena such as spatio-temporal illusions and masking are typically explained by psychological (cognitive processing theories or large-scale neural theories involving inter-areal connectivity and neural circuits comprising of hundreds or more interconnected single cells. Subcellular mechanisms are hardly used for such purpose. Here a mechanistic theoretical view is presented on how a subcellular brain mechanism of integration of presynaptic signals that arrive at different compartments of layer-5 pyramidal neurons could explain a couple of spatiotemporal visual-phenomenal effects unfolding along very brief time intervals within the range of sub-second temporal scale.

  16. Fuel cell elements with improved water handling capacity

    Science.gov (United States)

    Kindler, Andrew (Inventor); Lee, Albany (Inventor)

    2001-01-01

    New fuel cell components for use in liquid feed fuel cell systems are provided. The components include biplates and endplates, having a hydrophilic surface and allow high efficiency operation. Conductive elements and a wicking device also form a part of the fuel cell components of the invention.

  17. KSR-Based Medium Improves the Generation of High-Quality Mouse iPS Cells

    OpenAIRE

    2014-01-01

    Induced pluripotent stem (iPS) cells from somatic cells have great potential for regenerative medicine. The efficiency in generation of iPS cells has been significantly improved in recent years. However, the generation of high-quality iPS cells remains of high interest. Consistently, we demonstrate that knockout serum replacement (KSR)-based medium accelerates iPS cell induction and improves the quality of iPS cells, as confirmed by generation of chimeras and all iPS cell-derived offspring wi...

  18. Visual Impairment

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Visual Impairment KidsHealth > For Teens > Visual Impairment Print A ... with the brain, making vision impossible. What Is Visual Impairment? Many people have some type of visual ...

  19. Visual field

    Science.gov (United States)

    Perimetry; Tangent screen exam; Automated perimetry exam; Goldmann visual field exam; Humphrey visual field exam ... Confrontation visual field exam : This is a quick and basic check of the visual field. The health care provider ...

  20. Visual-motor coordination computerized training improves the visuo-spatial performance in a child affected by Cri-du-Chat syndrome.

    Science.gov (United States)

    Pizzamiglio, Maria Rosa; Nasti, Marianna; Piccardi, Laura; Vitturini, Claudio; Morelli, Daniela; Guariglia, Cecilia

    2008-06-01

    The present study reports on the effects of an experimental computerized training specifically conceived for improving visual-motor coordination in a child (L.D.J.) affected by Cri-du-Chat syndrome. The child was asked to touch a picture on the screen with a coordinated hand movement to obtain the appearance of a new picture. The training was organized into four levels of increasing difficulty, which were progressively administered in different sessions. Response times and number of errors were collected at each session. The child improved in performing computerized training, becoming faster and more accurate. Unlike control participants, she also improved in performing untrained tasks, which implied similar skills. Repercussions on L.D.J.'s autonomy and communication skills in daily life are described.

  1. 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.

  2. Review of physics underlying recent improvements in silicon solar-cell performance

    Science.gov (United States)

    Lindholm, F. A.; Fossum, J. G.

    1980-01-01

    This paper provides a unifying view of the physics of silicon solar cells, and uses it as a basis for explaining how recent improvements in the performance of these cells have been achieved. The unification is facilitated by a region-by-region analysis of the solar cell, which is also used to compare several recently proposed cell structures.

  3. 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.

  4. Minimal RED cell pairs markedly improve electrode kinetics and power production in microbial reverse electrodialysis cells.

    Science.gov (United States)

    Cusick, Roland D; Hatzell, Marta; Zhang, Fang; Logan, Bruce E

    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/m(2)), 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/m(2); WW: 1.9 W/m(2)). 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/m(2)-mem; WW: 1.7 W/m(2)) and 2-CP (Acetate: 1.3 W/m(2)-mem; WW: 0.6 W/m(2)) reactors were much higher than previous MRCs (0.3-0.5 W/m(2)-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.

  5. Efficiency improvement of silicon nanostructure-based solar cells.

    Science.gov (United States)

    Huang, Bohr-Ran; Yang, Ying-Kan; Yang, Wen-Luh

    2014-01-24

    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.

  6. 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.

  7. Study on Improvement Countermeasures for Visualized Logistics Information Platform%物流可视化信息平台问题及改进对策研究

    Institute of Scientific and Technical Information of China (English)

    唐雨薇

    2015-01-01

    探讨了可视化技术对物流信息平台的影响,对当前物流可视化信息平台存在的问题进行了详细介绍,并引入RFID技术对物流可视化信息平台进行改进,增强了物流可视化信息平台的透明度,使整个物流供应链体系都可以动态追踪与掌控物流配送过程,实现了可视化物流技术的协同管理.%In this paper, we discussed the influence of the visualization technology on the logistics information platform, introduced in detail the problems existing in the current visualized logistics information platform, and at the end introduced the RFID technology to improve it by enhancing the transparency of the platform and realizing the collaborative management of the logistics supply chain system using the visualization technologies.

  8. Matrigel improves functional properties of primary human salivary gland cells.

    Science.gov (United States)

    Maria, Ola M; Zeitouni, Anthony; Gologan, Olga; Tran, Simon D

    2011-05-01

    Currently, there is no effective treatment available to patients with irreversible loss of functional salivary acini caused by Sjogren's syndrome or after radiotherapy for head and neck cancer. A tissue-engineered artificial salivary gland would help these patients. The graft cells for this device must establish tight junctions in addition to being of fluid-secretory nature. This study analyzed a graft source from human salivary glands (huSG) cultured on Matrigel. Cells were obtained from parotid and submandibular glands, expanded in vitro, and then plated on either Matrigel-coated (2 mg/mL) or uncoated culture dish. Immunohistochemistry, transmission electron microscopy, quantitative real-time-polymerase chain reaction, Western blot, and transepithelial electrical resistance were employed. On Matrigel, huSG cells adopted an acinar phenotype by forming three-dimensional acinar-like units (within 24 h of plating) as well as a monolayer of cells. On uncoated surfaces (plastic), huSG cells only formed monolayers of ductal cells. Both types of culture conditions allowed huSG cells to express tight junction proteins (claudin-1, -2, -3, -4; occludin; JAM-A; and ZO-1) and adequate transepithelial electrical resistance. Importantly, 99% of huSG cells on Matrigel expressed α-amylase and the water channel protein Aquaporin-5, as compared to cells on plastic. Transmission electron microscopy confirmed an acinar phenotype with many secretory granules. Matrigel increased the secretion of α-amylase two to five folds into the media, downregulated certain salivary genes, and regulated the translation of acinar proteins. This three-dimensional in vitro serum-free cell culture method allows the organization and differentiation of huSG cells into salivary cells with an acinar phenotype.

  9. Appearance of actin microfilament 'twin peaks' in mitosis and their function in cell plate formation, as visualized in tobacco BY-2 cells expressing GFP-fimbrin.

    Science.gov (United States)

    Sano, Toshio; Higaki, Takumi; Oda, Yoshihisa; Hayashi, Tomomi; Hasezawa, Seiichiro

    2005-11-01

    The actin cytoskeleton of higher plants plays an essential role in plant morphogenesis and in maintaining various cellular activities. In this study we established a tobacco BY-2 cell line, stably transformed with a GFP-fimbrin actin-binding domain (ABD) 2 construct, that allows visualization of actin microfilaments (MFs) in living cells. Using this cell line, designated BY-GF11, we performed time-sequential observations of MF dynamics during cell-cycle progression. Detailed analyses revealed the appearance of a broad MF band in the late G2 phase that separated to form a structure corresponding to the so-called actin-depleted zone (ADZ) in mitosis. In BY-GF11, the MF structure at the cell cortex in mitosis appeared to form two bands rather than the ADZ. Measurements of fluorescent intensities of the cell cortex indicated an MF distribution that resembled two peaks, and we therefore named the structure MF 'twin peaks' (MFTP). The cell plate formed exactly within the valley between the MFTP at cytokinesis, and this cell-plate guidance was distorted by disruption of the MFTP by an inhibitor of actin polymerization. These results suggest that the MFTP originates from the broad MF band in the G2 phase and functions as a marker of cytokinesis.

  10. T Cell Receptor Activation of NF-κB in Effector T Cells: Visualizing Signaling Events Within and Beyond the Cytoplasmic Domain of the Immunological Synapse.

    Science.gov (United States)

    Traver, Maria K; Paul, Suman; Schaefer, Brian C

    2017-01-01

    The T cell receptor (TCR) to NF-κB signaling pathway plays a critical role in regulation of proliferation and effector T cell differentiation and function. In naïve T cells, data suggest that most or all key cytoplasmic NF-κB signaling occurs in a TCR-proximal manner at the immunological synapse (IS). However, the subcellular organization of cytoplasmic NF-κB-activating complexes in effector T cells is more complex, involving signaling molecules and regulatory mechanisms beyond those operative in naïve cells. Additionally, in effector T cells, much signaling occurs at cytoplasmic locations distant from the IS. Visualization of these cytoplasmic signaling complexes has provided key insights into the complex and dynamic regulation of NF-κB signal transduction in effector T cells. In this chapter, we provide in-depth protocols for activating and preparing effector T cells for fluorescence imaging, as well as a discussion of the effective application of distinct imaging methodologies, including confocal and super-resolution microscopy and imaging flow cytometry.

  11. Cell Factory Stability and Genetic Circuits for Improved Strain Development

    DEFF Research Database (Denmark)

    Rugbjerg, Peter

    Development of new chemical-­‐producing microbial cell factories is an iterative trial-­and-­error process, and to screen candidate cells at high throughput, genetic biosensor systems are appealing. Each biosensor has distinct biological parameters, making modular tuning networks attractive....... However, all synthetic gene systems -­ including the target metabolic pathways themselves -­ represent a possible fitness burden to the cell and thus constitute a threat to strain stability. In this thesis, several studies served to develop genetic systems for optimizing cell factory development...... factories in future....

  12. Mesenchymal Stem Cells Improve Healing of Diabetic Foot Ulcer

    Science.gov (United States)

    Sun, Chenglin

    2017-01-01

    Mesenchymal stem cells (MSCs), an ideal cell source for regenerative therapy with no ethical issues, play an important role in diabetic foot ulcer (DFU). Growing evidence has demonstrated that MSCs transplantation can accelerate wound closure, ameliorate clinical parameters, and avoid amputation. In this review, we clarify the mechanism of preclinical studies, as well as safety and efficacy of clinical trials in the treatment of DFU. Bone marrow-derived mesenchymal stem cells (BM-MSCs), compared with MSCs derived from other tissues, may be a suitable cell type that can provide easy, effective, and cost-efficient transplantation to treat DFU and protect patients from amputation. PMID:28386568

  13. Improving pattern discovery and visualization of SAGE data through poisson-based self-adaptive neural networks.

    Science.gov (United States)

    Zheng, Huiru; Wang, Haiying; Azuaje, Francisco

    2008-07-01

    Serial analysis of gene expression (SAGE) allows a detailed, simultaneous analysis of thousands of genes without the need for prior, complete gene sequence information. However, due to its inherent complexity and the lack of complete structural and function knowledge, mining vast collections of SAGE data to extract useful knowledge poses great challenges to traditional analytical techniques. Moreover, SAGE data are characterized by a specific statistical model that has not been incorporated into traditional data analysis techniques. The analysis of SAGE data requires advanced, intelligent computational techniques, which consider the underlying biology and the statistical nature of SAGE data. By addressing the statistical properties demonstrated by SAGE data, this paper presents a new self-adaptive neural network, Poisson-based growing self-organizing map (PGSOM), which implements novel weight adaptation and neuron growing strategies. An empirical study of key dynamic mechanisms of PGSOM is presented. It was tested on three datasets, including synthetic and experimental SAGE data. The results indicate that, in comparison to traditional techniques, the PGSOM offers significant advantages in the context of pattern discovery and visualization in SAGE data. The pattern discovery and visualization platform discussed in this paper can be applied to other problem domains where the data are better approximated by a Poisson distribution.

  14. Visualization-aided classification ensembles discriminate lung adenocarcinoma and squamous cell carcinoma samples using their gene expression profiles.

    Directory of Open Access Journals (Sweden)

    Ao Zhang

    Full Text Available INTRODUCTION: The widespread application of microarray experiments to cancer research is astounding including lung cancer, one of the most common fatal human tumors. Among non-small cell lung carcinoma (NSCLC, there are two major histological types of NSCLC, adenocarcinoma (AC and squamous cell carcinoma (SCC. RESULTS: In this paper, we proposed to integrate a visualization method called Radial Coordinate Visualization (Radviz with a suitable classifier, aiming at discriminating two NSCLC subtypes using patients' gene expression profiles. Our analyses on simulated data and a real microarray dataset show that combining with a classification method, Radviz may play a role in selecting relevant features and ameliorating parsimony, while the final model suffers no or least loss of accuracy. Most importantly, a graphic representation is more easily understandable and implementable for a clinician than statistical methods and/or mathematic equations. CONCLUSION: To conclude, using the NSCLC microarray data presented here as a benchmark, the comprehensive understanding of the underlying mechanism associated with NSCLC and of the mechanisms with its subtypes and respective stages will become reality in the near future.

  15. 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

  16. Improved classification, diagnosis and prognosis of canine round cell tumours

    NARCIS (Netherlands)

    Cangul, Taci

    2001-01-01

    As the name suggests, canine round cell tumour (RCTs) are composed of cells with a round morphology. There is some discrepancy amongst authors as to which tumours belong to this category, but most designate lymphomas, melanomas, plasmacytomas, transmissible venereal tumours (TVTs), histiocytomas, an

  17. 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.

  18. 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

  19. 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

    present the first super-resolution images of cellulose bundles in the plant cell wall produced by direct stochastic optical reconstruction microscopy (dSTORM) in combination with total internal reflection fluorescence (TIRF) microscopy. Since TIRF limits observation to the cell surface, we tested...... 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...... 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...

  20. Visualization of Cell Cycle Variations and Determination of Nucleation in Postnatal Cardiomyocytes.

    Science.gov (United States)

    Raulf, Alexandra; Voeltz, Nadine; Korzus, Daniel; Fleischmann, Bernd K; Hesse, Michael

    2017-02-24

    Cardiomyocytes are prone to variations of the cell cycle, such as endoreduplication (continuing rounds of DNA synthesis without karyokinesis and cytokinesis) and acytokinetic mitosis (karyokinesis but no cytokinesis). Such atypical cell cycle variations result in polyploid and multinucleated cells rather than in cell division. Therefore, to determine cardiac turnover and regeneration, it is of crucial importance to correctly identify cardiomyocyte nuclei, the number of nuclei per cell, and their cell cycle status. This is especially true for the use of nuclear markers for identifying cell cycle activity, such as thymidine analogues Ki-67, PCNA, or pHH3. Here, we present methods for recognizing cardiomyocytes and their nuclearity and for determining their cell cycle activity. We use two published transgenic systems: the Myh6-H2B-mCh transgenic mouse line, for the unequivocal identification of cardiomyocyte nuclei, and the CAG-eGFP-anillin mouse line, for distinguishing cell division from cell cycle variations. Combined together, these two systems ease the study of cardiac regeneration and plasticity.

  1. Transient maintenance in bioreactor improves health of neuronal cells.

    Science.gov (United States)

    Di Loreto, Silvia; Sebastiani, Pierluigi; Benedetti, Elisabetta; Zimmitti, Vincenzo; Caracciolo, Valentina; Amicarelli, Fernanda; Cimini, Annamaria; Adorno, Domenico

    2006-01-01

    To examine whether a neuronal cell suspension can be held in vitro for a relatively short period without compromising survival rates and functionality, we have set up an experimental protocol planning 24 h of suspension culture in a rotary wall vessel (RWV) bioreactor before plating in a conventional adherent system. Apoptosis measurement and activated caspase-8, -9, and -3 detection have demonstrated that survey of the cells was not affected. The activity of major antioxidant enzymes (AOE), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT), was significantly decreased in RWV-maintained cells. A significant decrease of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) is coupled with a level of activated nuclear factor-kappaB (NF-kappaB) protein significantly lower in RVW cells than in the control. On the contrary, the level of IL-6 expression did not change between the test and the control. A significant up-regulation of growth-associated protein-43 (GAP-43), peroxisome proliferator-activated receptor-beta/delta (PPARbeta/delta), and acyl-CoA synthetase 2 (ACS2) in RWV cells has been detected. We provide the evidence that primary neuronal cells, at an early stage of development, can be maintained in a suspension condition before adherent plating. This experimental environment does not induce detrimental effects but may have an activator role, leading cells to development and maturation in a tridimensional state.

  2. Improved immunoadsorption procedure with anion-exchange bacterial cell columns.

    Science.gov (United States)

    McKinney, R M; Thacker, L; Wong, M C; Hebert, G A

    1978-01-01

    Bacterial cell columns for immunoadsorption were prepared with Streptococcus cells and triethylaminoethyl cellulose (Cellex-T) matrix material as a model system. Good column flow properties and satisfactory retention of the cells were obtained with ratios as high as 2 ml of packed cells/3 g dry weight of cellulose. Anion-exchange fractionation of whole serum by the Cellex-T was prevented by using 0.25 M NaCl in the developing buffer. Antibodies were adsorbed directly from whole serum and recovered in high yield by desorption at pH 2.3. Pre-exposing bacterial cells to formalin and washing them with acetone was necessary to ensure that they remained on the columns. One strain of Streptococcus salivarius (SS 908) was satisfactorily retained on a column only after cells were labeled with fluorescein isothiocyanate and washed with acetone. The means by which Cellex-T retains bacterial cells appears to be a combination of electronic attraction and physical entrapment.

  3. Stem Cell Ophthalmology Treatment Study (SCOTS) for retinal and optic nerve diseases:a case report of improvement in relapsing auto-immune optic neuropathy

    Institute of Scientific and Technical Information of China (English)

    Jeffrey N Weiss; Steven Levy; Susan C Benes

    2015-01-01

    We present the results from a patient with relapsing optic neuropathy treated within the Stem Cell Ophthalmology Treatment Study (SCOTS). SCOTS is an Institutional Review Board ap-proved clinical trial and has become the largest ophthalmology stem cell study registered at the National Institutes of Health to date (www.clinicaltrials.gov Identiifer NCT 01920867). SCOTS utilizes autologous bone marrow-derived stem cells (BMSCs) for treatment of retinal and optic nerve diseases. Pre-treatment and post-treatment comprehensive eye exams of a 54 year old female patient were performed both at the Florida Study Center, USA and at The Eye Center of Columbus, USA. As a consequence of a relapsing optic neuritis, the patient’s previously normal visual acuity decreased to between 20/350 and 20/400 in the right eye and to 20/70 in the left eye. Signiifcant visual ifeld loss developed bilaterally. The patient underwent a right eye vitrectomy with injection of BMSCs into the optic nerve of the right eyeand retrobulbar, subtenon and in-travitreal injection of BMSCs in the left eye. At 15 months after SCOTS treatment, the patient’s visual acuity had improved to 20/150 in the right eye and 20/20 in the left eye. Bilateral visual fields improved markedly. Both macular thickness and fast retinal nerve fiber layer thickness were maximally improved at 3 and 6 months after SCOTS treatment. The patient also reduced her mycophenylate dose from 1,500 mg per day to 500 mg per day and required no steroid pulse therapy during the 15-month follow up.

  4. Intelligent Control for Improvements in PEM Fuel Cell Flow Performance

    Institute of Scientific and Technical Information of China (English)

    Jonathan G Williams; Guoping Liu; Senchun Chai; David Rees

    2008-01-01

    The performance of fuel cells and the vehicle applications they are embedded into depends on a delicate balance of the correct temperature, humidity, reactant pressure, purity and flow rate. This paper successfully investigates the problem related to flow control with implementation on a single cell membrane electrode assembly (MEA). This paper presents a systematic approach for performing system identification using recursive least squares identification to account for the non-linear parameters of the fuel cell. Then, it presents a fuzzy controller with a simplified rule base validated against real time results with the existing flow controller which calculates the flow required from the stoichiometry value.

  5. Stroma-conditioned media improve expansion of human primitive hematopoietic stem cells and progenitor cells.

    Science.gov (United States)

    Breems, D A; Blokland, E A; Ploemacher, R E

    1997-01-01

    It has been reported that stroma-dependent cultures support proliferation of hematopoietic stem cells (HSC). In order to investigate the effect of soluble stromal factors, we developed short-term serum-low liquid cultures in which the effect of stroma-conditioned media (SCM) from the murine FBMD-1, and human L87/4 and L88/5 cell lines was studied on the maintenance and expansion of various human HSC subsets in CD34-positive selected mobilized peripheral blood stem cells (PBSC) from autologous transplants of lymphoma and multiple myeloma patients. The human cobblestone area forming cell (CAFC) assay was employed to determine the frequencies of both the CAFC weeks 2 to 4 as tentative indicators of progenitor and transiently repopulating HSC, and the more primitive CAFC weeks 6 to 8 as indicators of long-term repopulating HSC. In 7-day liquid cultures containing interleukin-3 (IL-3), stem cell factor (SCF) and IL-6, we recovered 3.0-fold more colony-forming cells (CFC) and 1.7- to 1.9-fold more CAFC weeks 2 and 4. The absolute number of primitive CAFC weeks 6 and 8 were only maintained (1.1- to 1.4-fold) in these liquid cultures. This modest expansion was significantly improved by the addition of SCM from the FBMD-1, L87/4 or L88/5 cell lines. Output CFC numbers were 6.8-, 5.8- and 9.9-fold higher, respectively, than the input values, while absolute CAFC week 2 to 4 numbers were 4.5-, 10.2- and 10.2-fold expanded, respectively. The addition of SCM also improved expansion of the more primitive CAFC week 6 to 8 stem cell subsets by 2.2-, 4.5- and 4.9-fold, respectively. The addition of granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage-CSF (GM-CSF), IL-1beta, IL-11 or macrophage inflammatory protein-1alpha to cultures containing IL-3, SCF and IL-6 could not explain the SCM effect and in all these combinations SCM addition further increased the recovery of HSC subsets. Similarly, addition of anti-cytokine antibodies (ie alpha-G-CSF, alpha-GM-CSF, alpha

  6. Direct visualization of macrophage-assisted tumor cell intravasation in mammary tumors.

    Science.gov (United States)

    Wyckoff, Jeffrey B; Wang, Yarong; Lin, Elaine Y; Li, Jiu-feng; Goswami, Sumanta; Stanley, E Richard; Segall, Jeffrey E; Pollard, Jeffrey W; Condeelis, John

    2007-03-15

    Although the presence of macrophages in tumors has been correlated with poor prognosis, until now there was no direct observation of how macrophages are involved in hematogenous metastasis. In this study, we use multiphoton microscopy to show, for the first time, that tumor cell intravasation occurs in association with perivascular macrophages in mammary tumors. Furthermore, we show that perivascular macrophages of the mammary tumor are associated with tumor cell intravasation in the absence of local angiogenesis. These results show that the interaction between macrophages and tumor cells lying in close proximity defines a microenvironment that is directly involved in the intravasation of cancer cells in mammary tumors.

  7. Improving productivity and reducing operating costs with fuel cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Hoying, T. [Cellex Power Products Inc., Richmond, BC (Canada)

    2004-07-01

    This short corporate white paper addresses the advantages to fleet lift truck operators of converting to fuel cells from conventional electric battery technology. Conventional batteries are heavy for the energy they store. In addition, large operations require special equipment to change batteries, something that occurs at frequent intervals (4-8 hours). Some of the disadvantages of batteries include requirements such as an eye wash safety program, floor drainage for battery acid containment, and ventilation. The paper asserts that the larger the operation, the greater the problem of overall battery management. It cites the higher energy density of fuel cells as their prime advantage; fueling time is shorter than the time needed to change a battery, and times between refueling/changing is one and a half to two time greater for the fuel cell. In addition to the economic benefits of fuel cells, they do not produce harmful emissions.

  8. 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...

  9. Improved analytical current voltage characteristics of a solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Yli-Koski, M.; Tuominen, E.; Acerbis, M.; Sinkkonen, J.

    1997-12-31

    Application of the Green`s function method to the calculation of the current voltage characteristics of a pn-junction solar cell makes possible to extract more reliable and exact information about the behavior of the cell. With this method not only the minority carrier diffusion currents but also the drift currents in quasi- neutral regions of the solar cell can be taken into consideration. Furthermore, this approach is not limited to an exponentially decaying minority carrier generation function but is valid for any type of optical generation. In addition, the injection boundary condition is exploited with the result that not only the pn-diode current but also the current resulting from the optical generation depends on the voltage of the solar cell. Applying the method also gives the so called position dependent collection efficiency function which is defined as the probability that an electron-hole pair created at a certain point inside the solar cell will contribute to the current leaving the cell. (orig.) 15 refs.

  10. 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

    -negative derivatives of Pseudomonas putida IsoF and Serratia liquefaciens MG1, two strains that are capable of colonizing tomato roots. These AHL monitor strains were used to visualize communication between defined bacterial populations in the rhizosphere of axenically grown tomato plants. Furthermore, we integrated...... 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...

  11. 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.

  12. Design issues for improved environmental performance of dye-sensitized and organic nanoparticulate solar cells

    NARCIS (Netherlands)

    Reijnders, L.

    2010-01-01

    Though environmental improvement has been claimed for the application of nanotechnology to solar cells, several characteristics of the fullerene-based organic, and the dye-sensitized nanoparticulate, solar cell are not conducive to such improvement. These include relatively high energy and materials

  13. PLGA-encapsulated perfluorocarbon nanoparticles for simultaneous visualization of distinct cell populations by (19)F MRI

    NARCIS (Netherlands)

    Srinivas, M.; Tel, J.; Schreibelt, G.; Bonetto, F.J.; Cruz, L.J.; Amiri, H.; Heerschap, A.; Figdor, C.G.; Vries, I.J.M. de

    2015-01-01

    AIM: In vivo imaging using (19)F MRI is advantageous, due to its ability to quantify cell numbers, but is limited for a lack of suitable labels. Here, we formulate two stable and clinically applicable labels for tracking two populations of primary human dendritic cells (DCs) simultaneously. MATERIAL

  14. Visualization of the specific interaction of sulfonylurea-incorporated polymer with insulinoma cell line MIN6.

    Science.gov (United States)

    Park, Keun-Hong; Akaike, Toshihiro

    2004-02-01

    A derivative of sulfonylurea (SU) that mimics glibenclamide in chemical structure was synthesized and incorporated into a water-soluble polymeric backbone as a biospecific polymer for stimulating insulin secretion. In this study, a backbone polymer fluorescence-labeled with rodamine-B isothiocyanate was found to be strongly adsorbed onto MIN6 cells, probably due to its specific interaction mediated by SU receptors on the cell membrane. The intensity of fluorescence on the cells was significantly increased by increasing the incubation time and polymer concentration. To verify the specific interaction between the SU (K(+) channel closer)-incorporated copolymer and MIN6 cells, the cells were pretreated with diazoxide, an agonist of the ATP-sensitive K(+) channel (K(+) channel opener), before adding the polymer to the cell culture medium. This treatment suppressed the interaction between SU and MIN6 cells. A confocal laser microscopic study confirmed this effect. The results of this study provide evidence that SU-incorporated copolymer stimulates insulin secretion through the specific interactions of SU moieties in the polymer with MIN6 cells.

  15. 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.

  16. 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.

  17. Visually guided whole cell patch clamp of mouse supraoptic nucleus neurons in cultured and acute conditions.

    Science.gov (United States)

    Stachniak, Tevye J E; Bourque, Charles W

    2006-07-01

    Recent advances in neuronal culturing techniques have supplied a new set of tools for studying neural tissue, providing effective means to study molecular aspects of regulatory elements in the supraoptic nucleus of the hypothalamus (SON). To combine molecular biology techniques with electrophysiological recording, we modified an organotypic culture protocol to permit transfection and whole cell patch-clamp recordings from SON cells. Neonatal mouse brain coronal sections containing the SON were dissected out, placed on a filter insert in culture medium, and incubated for at least 4 days to allow attachment to the insert. The SON was identifiable using gross anatomical landmarks, which remained intact throughout the culturing period. Immunohistochemical staining identified both vasopressinergic and oxytocinergic cells present in the cultures, typically appearing in well-defined clusters. Whole cell recordings from these cultures demonstrated that certain properties of the neonatal mouse SON were comparable to adult mouse magnocellular neurons. SON neurons in both neonatal cultures and acute adult slices showed similar sustained outward rectification above -60 mV and action potential broadening during evoked activity. Membrane potential, input resistance, and rapidly inactivating potassium current density (IA) were reduced in the cultures, whereas whole cell capacitance and spontaneous synaptic excitation were increased, perhaps reflecting developmental changes in cell physiology that warrant further study. The use of the outlined organotypic culturing procedures will allow the study of such electrophysiological properties of mouse SON using whole cell patch-clamp, in addition to various molecular, techniques that require longer incubation times.

  18. Patterning processes in aggregates of Hydra cells visualized with the monoclonal antibody, TS19.

    Science.gov (United States)

    Sato, M; Bode, H R; Sawada, Y

    1990-10-01

    The monoclonal antibody, TS19, (Heimfeld et al., 1985), labels the apical surface of ectodermal epithelial cells of tentacles and lower peduncles in Hydra. To investigate the patterning process in a tissue whose original pattern was completely destroyed, the TS19 staining pattern was examined in developing aggregates of Hydra cells. Two types of aggregates were prepared. G-aggregates were made from tissue of the gastric portion of animals and RG-aggregates from gastric tissue allowed to regenerate for 24 hr before making aggregates. G-aggregates were initially TS19-negative, and later dim and uniformly TS19-positive. Thereafter, TS19 staining broke up into brightly stained and unstained regions. The brightly staining regions developed into head or foot structures. The TS19 pattern in RG-aggregates developed differently. Since the initial aggregates contained cells of regenerating tips, they started with TS19-positive cells as well as TS19-negative cells. The numbers of brightly staining TS19-positive cells increased with time. Some patches of these cells developed into head or foot structures, while others did not. These results and a simulation using a reaction-diffusion model suggest that the changes in activation levels affected the temporal changes in the pattern of TS19 staining, and that the de novo pattern formation in hydra can be explained in terms of a process involving activation and inhibition properties.

  19. Novel and improved yeast cell factories for biosustainable processes

    DEFF Research Database (Denmark)

    Workman, Mhairi

    2014-01-01

    utilizing traditionally applied cell factories are generally based on a limited range of substrates (mainly glucose). However, a wider diversity in substrate range is highly desirable in developing biorefinery scenarios where feed-stocks containing a number of carbon sources are typically employed....... In addition to plant biomass hydrolysates, glycerol is of interest here, being available in amounts relevant for industrial scale bioprocesses due to increased production of biodiesel. The well characterised cell factory Saccharomyces cerevisiae exhibits a clear preference for glucose as a carbon source...... 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...

  20. Comparison of Narrowband Imaging with Autofluorescence Imaging for Endoscopic Visualization of Superficial Squamous Cell Carcinoma Lesions of the Esophagus

    Directory of Open Access Journals (Sweden)

    Haruhisa Suzuki

    2012-01-01

    Full Text Available Aim. To compare narrowband imaging (NBI and autofluorescence imaging (AFI endoscopic visualization for identifying superficial esophageal squamous cell carcinoma (SCC. Methods. Twenty-four patients with superficial esophageal carcinomas diagnosed at previous hospitals were enrolled in this study. Lesions were initially detected using white-light endoscopy and then observed with both NBI and AFI. Endoscopic images documented each method, and three endoscopists experienced in esophageal imaging retrospectively reviewed respective images of histologically confirmed esophageal SCCs. Images were assessed for quality in identifying superficial SCCs and rated as excellent, fair, or poor by the three reviewers with interobserver agreement calculated using kappa (κ statistics. Results. Thirty-one lesions histologically confirmed as superficial esophageal SCCs were detected in 24 patients. NBI images of 27 lesions (87% were rated as excellent, three as fair, and one as poor compared to AFI images of 19 lesions (61% rated as excellent, 10 as fair and two as poor (P<0.05. Moderate interobserver agreement (κ=0.42, 95% CI 0.24–0.60 resulted in NBI while fair agreement (κ=0.35, 95% CI 0.18–0.51 was achieved using AFI. Conclusion. NBI may be more effective than AFI for visualization of esophageal SCC.

  1. Visual detection of Akt mRNA in living cell using gold nanoparticle beacon

    Science.gov (United States)

    Ma, Yi; Tian, Caiping; Li, Siwen; Wang, Zhaohui; Gu, Yueqing

    2014-09-01

    PI3K-Akt signaling pathway plays the key role in cell apoptosis and survival, and the components of PI3K /Akt signaling pathway are often abnormally expressed in human tumors. Therefore, determination of the Akt (protein kinase B, PKB) messenger ribonucleic acid (mRNA) expression is significantly important in understanding the mechanism of tumor progression. In this study, we designed a special hairpin deoxyribonucleic acid (DNA) functionalized with gold nanoparticles and fluorescein isothiocyanate(FITC) as a beacon for detecting human Akt mRNA. Spectrofluorometer was used to detect the fluorescence quenching and recovery of the beacons, and laser confocal scanning microscopy was adopted to image Akt mRNA in cells. The results showed that this beacon could sensitively and quantitatively measure the Akt mRNA in living cells . This strategy is potentially useful for the cellular imaging of RNA or protein expression in living cells.

  2. Visualization and identification of IL-7 producing cells in reporter mice.

    Directory of Open Access Journals (Sweden)

    Renata I Mazzucchelli

    Full Text Available Interleukin-7 (IL-7 is required for lymphocyte development and homeostasis although the actual sites of IL-7 production have never been clearly identified. We produced a bacterial artificial chromosome (BAC transgenic mouse expressing ECFP in the Il7 locus. The construct lacked a signal peptide and ECFP (enhanced cyan fluorescent protein accumulated inside IL-7-producing stromal cells in thoracic thymus, cervical thymus and bone marrow. In thymus, an extensive reticular network of IL-7-containing processes extended from cortical and medullary epithelial cells, closely contacting thymocytes. Central memory CD8 T cells, which require IL-7 and home to bone marrow, physically associated with IL-7-producing cells as we demonstrate by intravital imaging.

  3. Magnetically levitated nano-robots: an application to visualization of nerve cells injuries.

    Science.gov (United States)

    Lou, Mingji; Jonckheere, Edmond

    2007-01-01

    This paper proposes a swarm of magnetically levitated nano-robots with high sensitivity nano-sensors as a mean to detect chemical sources, specifically the chemical signals released by injured nervous cells. In the aftermath of the process, further observation by these nano-robots would be used to monitor the healing process and assess the amount of regeneration, if any, or even the repair, of the injured nervous cells.

  4. Construction of an electrochemical cell to visualize samples in situ in stereomicroscope

    OpenAIRE

    Mônica Alessandra Silva Alencar; Assis Vicente Benedetti; Cecílio Sadao Fugivara; Younès Messaddeq

    2010-01-01

    The electrochemical study of glass like tungsten oxide derivatives requires the construction of special electrodes due to the fact that these glasses are not conductive. Electrodes modified with WO3 change their color when submitted to some potential perturbation. The color change of the electrochromic materials was observed in situ by coupling an electrochemical cell to a stereomicroscope. The constructed cell is versatile and may represent a great contribution to the electrochemical studies...

  5. Mast Cell Inhibition Improves Pulmonary Vascular Remodeling in Pulmonary Hypertension

    NARCIS (Netherlands)

    Bartelds, Beatrijs; van Loon, Rosa Laura E.; Mohaupt, Saffloer; Wijnberg, Hans; Dickinson, Michael G.; Takens, Janny; van Albada, Mirjam; Berger, Rolf M. F.; Boersma, B.

    2012-01-01

    Background: Pulmonary arterial hypertension (PAH) is a progressive angioproliferative disease with high morbidity and mortality. Although the histopathology is well described, its pathogenesis is largely unknown. We previously identified the increased presence of mast cells and their markers in a ra

  6. Entropic and Near-Field Improvements of Thermoradiative Cells

    Science.gov (United States)

    Hsu, Wei-Chun; Tong, Jonathan K.; Liao, Bolin; Huang, Yi; Boriskina, Svetlana V.; Chen, Gang

    2016-10-01

    A p-n junction maintained at above ambient temperature can work as a heat engine, converting some of the supplied heat into electricity and rejecting entropy by interband emission. Such thermoradiative cells have potential to harvest low-grade heat into electricity. By analyzing the entropy content of different spectral components of thermal radiation, we identify an approach to increase the efficiency of thermoradiative cells via spectrally selecting long-wavelength photons for radiative exchange. Furthermore, we predict that the near-field photon extraction by coupling photons generated from interband electronic transition to phonon polariton modes on the surface of a heat sink can increase the conversion efficiency as well as the power generation density, providing more opportunities to efficiently utilize terrestrial emission for clean energy. An ideal InSb thermoradiative cell can achieve a maximum efficiency and power density up to 20.4% and 327 Wm‑2, respectively, between a hot source at 500 K and a cold sink at 300 K. However, sub-bandgap and non-radiative losses will significantly degrade the cell performance.

  7. Prose Learning in Children and Adults with Down Syndrome: The Use of Visual and Mental Image Strategies to Improve Recall

    Science.gov (United States)

    de la Iglesia, Carmen J. F.; Buceta, M. Jose; Campos, Alfredo

    2005-01-01

    Background: Research indicates that the use of mental imagery is a rich source of possibilities for improving learning in participants with learning disabilities and intellectual disability. Method: We undertook two experiments designed to assess the effectiveness of using imagery in prose learning for participants with Down syndrome (DS). The…

  8. Requirements for future control room and visualization features in the Web-of-Cells framework defined in the ELECTRA project

    DEFF Research Database (Denmark)

    Tornelli, Carlo; Zuelli, Roberto; Marinelli, Mattia

    2017-01-01

    This paper outlines an overview of the general requirements for the control rooms of the future power systems (2030+). The roles and activities in the future control centres will evolve with respect to the switching, dispatching and restoration functions currently active. The control centre...... operators will supervise on the power system and intervene - when necessary - thanks to the maturation and wide scale deployment of flexible controls. For the identification of control room requirements, general trends in power system evolution are considered and mainly the outcomes of the ELECTRA IRP...... project, that proposes a new Web-of-Cell (WoC) power system control architecture. Dedicated visualization features are proposed, aimed to support the control room operators activities in a WoC oriented approach. Furthermore, the work takes into account the point of view of network operators about future...

  9. Cell-Targeted Optogenetics and Electrical Microstimulation Reveal the Primate Koniocellular Projection to Supra-granular Visual Cortex.

    Science.gov (United States)

    Klein, Carsten; Evrard, Henry C; Shapcott, Katharine A; Haverkamp, Silke; Logothetis, Nikos K; Schmid, Michael C

    2016-04-01

    Electrical microstimulation and more recently optogenetics are widely used to map large-scale brain circuits. However, the neuronal specificity achieved with both methods is not well understood. Here we compare cell-targeted optogenetics and electrical microstimulation in the macaque monkey brain to functionally map the koniocellular lateral geniculate nucleus (LGN) projection to primary visual cortex (V1). Selective activation of the LGN konio neurons with CamK-specific optogenetics caused selective electrical current inflow in the supra-granular layers of V1. Electrical microstimulation targeted at LGN konio layers revealed the same supra-granular V1 activation pattern as the one elicited by optogenetics. Taken together, these findings establish a selective koniocellular LGN influence on V1 supra-granular layers, and they indicate comparable capacities of both stimulation methods to isolate thalamo-cortical circuits in the primate brain.

  10. 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.

  11. Giant lens, a gene involved in cell determination and axon guidance in the visual system of Drosophila melanogaster.

    Science.gov (United States)

    Kretzschmar, D; Brunner, A; Wiersdorff, V; Pflugfelder, G O; Heisenberg, M; Schneuwly, S

    1992-01-01

    Mutations in the Drosophila gene giant lens (gil) affect ommatidial development, photoreceptor axon guidance and optic lobe development. We have cloned the gene using an enhancer trap line. Molecular analysis of gil suggests that it encodes a secreted protein with an epidermal-growth-factor-like motif. We have generated mutations at the gil locus by imprecise excision of the enhancer trap P-element. In the absence of gil, additional photoreceptors develop at the expense of pigment cells, suggesting an involvement of gil in cell determination during eye development. In addition, gil mutants show drastic effects on photoreceptor axon guidance and optic lobe development. In wildtype flies, photoreceptor axons grow from the eye disc through the optic stalk into the larval brain hemisphere, where retinal innervation is required for the normal development of the lamina and distal medulla. The projection pattern of these axons in the developing lamina and medulla is highly regular and reproducible. In gil, photoreceptor axons enter the larval brain but fail to establish proper connections in the lamina or medulla. We propose that gil encodes a new type of signalling molecule involved in the process of axon pathfinding and cell determination in the visual system of Drosophila. Images PMID:1628618

  12. 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.

  13. Single cell visualization of transcription kinetics variance of highly mobile identical genes using 3D nanoimaging.

    Science.gov (United States)

    Annibale, Paolo; Gratton, Enrico

    2015-03-19

    Multi-cell biochemical assays and single cell fluorescence measurements revealed that the elongation rate of Polymerase II (PolII) in eukaryotes varies largely across different cell types and genes. However, there is not yet a consensus whether intrinsic factors such as the position, local mobility or the engagement by an active molecular mechanism of a genetic locus could be the determinants of the observed heterogeneity. Here by employing high-speed 3D fluorescence nanoimaging techniques we resolve and track at the single cell level multiple, distinct regions of mRNA synthesis within the model system of a large transgene array. We demonstrate that these regions are active transcription sites that release mRNA molecules in the nucleoplasm. Using fluctuation spectroscopy and the phasor analysis approach we were able to extract the local PolII elongation rate at each site as a function of time. We measured a four-fold variation in the average elongation between identical copies of the same gene measured simultaneously within the same cell, demonstrating a correlation between local transcription kinetics and the movement of the transcription site. Together these observations demonstrate that local factors, such as chromatin local mobility and the microenvironment of the transcription site, are an important source of transcription kinetics variability.

  14. Schwann cell coculture improves the therapeutic effect of bone marrow stromal cells on recovery in spinal cord-injured mice.

    Science.gov (United States)

    Xu, Xiaoyun; Geremia, Nicole; Bao, Feng; Pniak, Anna; Rossoni, Melissa; Brown, Arthur

    2011-01-01

    Studies of bone marrow stromal cells (MSCs) transplanted into the spinal cord-injured rat give mixed results: some groups report improved locomotor recovery while others only demonstrate improved histological appearance of the lesion. These studies show no clear correlation between neurological improvements and MSC survival. We examined whether MSC survival in the injured spinal cord could be enhanced by closely matching donor and recipient mice for genetic background and marker gene expression and whether exposure of MSCs to a neural environment (Schwann cells) prior to transplantation would improve their survival or therapeutic effects. Mice underwent a clip compression spinal cord injury at the fourth thoracic level and cell transplantation 7 days later. Despite genetic matching of donors and recipients, MSC survival in the injured spinal cord was very poor (∼1%). However, we noted improved locomotor recovery accompanied by improved histopathological appearance of the lesion in mice receiving MSC grafts. These mice had more white and gray matter sparing, laminin expression, Schwann cell infiltration, and preservation of neurofilament and 5-HT-positive fibers at and below the lesion. There was also decreased collagen and chondroitin sulphate proteoglycan deposition in the scar and macrophage activation in mice that received the MSC grafts. The Schwann cell cocultured MSCs had greater effects than untreated MSCs on all these indices of recovery. Analyses of chemokine and cytokine expression revealed that MSC/Schwann cell cocultures produced far less MCP-1 and IL-6 than MSCs or Schwann cells cultured alone. Thus, transplanted MSCs may improve recovery in spinal cord-injured mice through immunosuppressive effects that can be enhanced by a Schwann cell coculturing step. These results indicate that the temporary presence of MSCs in the injured cord is sufficient to alter the cascade of pathological events that normally occurs after spinal cord injury, generating a

  15. 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.

  16. Multiple Knudsen Cell Configuration Improved for Alloy Activity Studies

    Science.gov (United States)

    Copland, Evan H.; Jacobson, Nathan S.

    2003-01-01

    Knudsen effusion mass spectrometry (KEMS) allows the simultaneous determination of the identity and pressure of vapor species in equilibrium with a condensed phase as a function of temperature. This information can be used to determine the thermodynamic properties of materials. The partial pressure of species j in the cell is related to the measured intensity of the ion k formed from j, I(sup +) less than SABjk, and the absolute temperature T, where S(sub jk) is the sensitivity factor.

  17. Organic Semiconductors for Sprayable Solar Cells: Improving Stability and Efficiency

    Science.gov (United States)

    2008-03-25

    ITO surfaces Issues with poor charge collection from low- conductivity PEDOT/PSS Investigate methods to spray-deposit high performance anode...new, soluble, air-stable acceptors to match with polythiophene (specifically, P3HT) donors. The acceptor systems designed and synthesized by the...group also investigated improving the conductivity of the anode by spray-coating gold nanoparticles on top of the PEDOT-PSS layer. Again, for initial

  18. Deglycosylation of glucose oxidase to improve biosensors and biofuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Prevoteau, Antonin; Courjean, Olivier; Mano, Nicolas [Universite de Bordeaux, CNRS, Centre de Recherche Paul Pascal (CRPP), UPR 8641, Avenue Albert Schweitzer, 33600 Pessac (France)

    2010-02-15

    We demonstrate that a more efficient redox hydrogel structure can be achieved by engineering the size and the surface charge of the bioelectrocatalyst. Deglycosylated glucose oxidase (GOx) modified electrode exhibits higher current density than native GOx, for the same molar composition of the hydrogel. This improvement is very likely due to a more efficient hydrogel structure rather than a better intrinsic electron transfer between the FAD/FADH{sub 2} redox center and the redox mediator. (author)

  19. Visualization of Hierarchical Nanodomains in Polymer/Fullerene Bulk Heterojunction Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Jianguo; Miller, Dean J.; Chen, Wei; Xu, Tao; Yu, L; Darling, Seth B.; Zaluzec, Nestor J.

    2014-10-01

    raditional electron microscopy techniques such as bright-field imaging provide poor contrast for organic films and identification of structures in amorphous material can be problematic, particularly in high- performance organic solar cells. By combining energy-filtered corrected transmission electron microscopy, together with electron energy loss and X-ray energy-dispersive hyperspectral imaging, we have imaged PTB7/ PC61BM blended polymer optical photovoltaic films, and were able to identify domains ranging in size from several hundred nanometers to several nanometers in extent. This work verifies that microstructural domains exist in bulk heterojunctions in PTB7/PC61BM polymeric solar cells at multiple length scales and expands our understanding of optimal device performance providing insight for the design of even higher performance cells.

  20. 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.

  1. 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.

  2. 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 lining 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 100kPa.We discuss mechanical effects on the development of actin filament networks.

  3. 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.

  4. Modeling and visualization of the activation wavefront propagation to improve understanding the QRS complex changes indicating left ventricular hypertrophy.

    Science.gov (United States)

    Svehlikova, Jana; Zelinka, Jan; Bacharova, Ljuba; Tysler, Milan

    2016-01-01

    Activation wavefront propagation was computed and visualized in a geometrical heart model for pathological cases of reduced velocity of propagation, left ventricular hypertrophy and their combination. Selected parameters of a multiple dipole equivalent heart generator were computed and compared for three heart geometries and several degrees and extents of reduction of propagation velocity. First, the influence of geometrical changes modeling the left ventricular hypertrophy at reference propagation velocity was compared with reduction of the propagation velocity in the reference heart geometry. Reduced propagation velocity yielded similar or greater changes of the magnitude of the (electrical) heart vector representing the activation wavefront than the geometrical changes. Observations of the wavefront propagation with reduced velocity revealed longer presence of a large extent of the wavefront during depolarization which resulted in increased magnitude of the heart vector. The duration of depolarization was significantly prolonged only when the propagation velocity was decreased to 25% of its normal value. Changes of the direction of the maximal heart vector were dependent on the position of the region where the propagation velocity was reduced. Then the combination of the left ventricular hypertrophy and reduced propagation velocity was studied. Such combination enhanced the enlargement of the electrical heart vector and significantly prolonged the duration of depolarization. The influence of reduced activation velocity on the observed parameters was greater than the effect of the enlargement of the left ventricular mass. The presented study showed that intramyocardial conduction disturbances might cause increase of the actual surface area of propagation wavefront leading to changes of the amplitudes of ECG signals comparable with the changes resulting from the left ventricular hypertrophy. Intramyocardial conduction disturbances, as well as the modeled 50

  5. Improved electric energy production of solar cell using small silver nanoparticles

    Science.gov (United States)

    Wang, X. Y.; Li, H. F.; Shi, S.; Wang, J. L.

    2017-03-01

    The influence of small Ag nanoparticles (NPs) on the all-day electric energy production of solar cells has been investigated. The small Ag NPs were deposited on the cell surface by the magnetron sputtering system. The cell without NPs is used as a reference cell. The external quantum efficiency (EQE) curves indicate that the performance of cell with 8% nanoparticle coverage is better than that of other cells in the long wavelength band. The maximum power-angle curves indicate that the small Ag NPs can effectively improve the all-day electric energy production of solar cell. Comparing with the values of reference cell, the half peak height of maximum power for cell optimized increases by 65%, and the half peak breadth of maximum power for cell optimized broadens by 3%. The enhancements of optimum operating current and optimum operating voltage lead directly to the enhancement of maximum power.

  6. 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

  7. 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.

  8. MRI visualization of endogenous neural progenitor cell migration along the RMS in the adult mouse brain

    DEFF Research Database (Denmark)

    Vreys, Ruth; Vande Velde, Greetje; Krylychkina, Olga

    2010-01-01

    neurogenesis. Quantitative analysis of bromodeoxyuridine labeled cells revealed altered proliferation in the SVZ and NPC migration after in situ MPIO injection. From the labeling strategies presented in this report, intraventricular injection of a small number of MPIOs combined with the transfection agent poly...... the impact on adult neurogenesis when new in situ labeling strategies are developed....

  9. 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.

  10. Visualization of specific gene expression in individual Salmonella typhimurium cells by in situ PCR

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim; Holmstrøm, Kim; Molin, Søren

    1997-01-01

    reporter molecule-labeled primers, and subsequently, intracellular reporter molecules are detected microscopically at the individual-cell level by use of a horseradish peroxidase-conjugated antifluorescein antibody assay. In order to determine the sensitivity of the in situ PCR assay, the ability to detect...

  11. 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 desc...

  12. Three-dimensional visualization of virus-infected cells by serial sectioning: an electron microscopic study using resin embedded cells.

    Science.gov (United States)

    Schauflinger, Martin; Villinger, Clarissa; Walther, Paul

    2013-01-01

    In this paper we show how to obtain a three-dimensional model of virus-infected cells by serial sectioning of resin embedded samples and transmission electron microscopic imaging. The method bases on sample fixation by high pressure freezing and processing by freeze substitution with the goal to preserve the structures of interest close to the natural state, as previously described (Walther et al., High pressure freezing for scanning transmission electron tomography analysis of cellular organelles. In: Mossman BT, Taatjes DJ (eds) Cell imaging techniques, vol 931, Methods in molecular biology. Humana Press, Totowa, NJ, pp 525-535, 2013). Advantages of serial sectioning compared to that of other tomographic methods are as follows: No special and expensive additional equipment is required. Relatively large volumes, such as whole cells, can be three-dimensionally reconstructed in a reasonable amount of time. Serial sectioning is a non-destructive method; the sections can be stored, re-imaged, or processed for immunogold labeling when more specific data are requested or when new scientific questions are raised (e.g., higher magnifications, protein distributions). We have recently used this method to obtain a three-dimensional model of the complete assembly complex of an HCMV infected cell, which allowed a detailed insight into this virally induced compartment (Schauflinger et al., Cell Microbiol 15(2):305-314, 2013).

  13. 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.

  14. Simultaneous visualization of oxygen partial pressure, current density, and water droplets in serpentine fuel cell during power generation for understanding reaction distributions

    Science.gov (United States)

    Takanohashi, Kazuhiro; Suga, Takeo; Uchida, Makoto; Ueda, Toshihide; Nagumo, Yuzo; Inukai, Junji; Nishide, Hiroyuki; Watanabe, Masahiro

    2017-03-01

    Understanding the reaction distributions inside a polymer electrolyte fuel cell (PEFC) is essential for the higher performance and durability. We have developed a new see-through cell and visualized the distributions of oxygen partial pressure and current density inside a running PEFC at the temperature of 40 and 80 °C and the relative humidity of 53%. The oxygen utilization was changed from 0% to 80% by changing the current density. At higher oxygen utilizations, the current density was higher and therefore the water generation. Generated water droplets in the flow channel were also visualized, allowing for the simultaneous visualization of the distribution of the oxygen partial pressure, current density, and water droplets. By combining the observations of all three parameters, the reactions inside a membrane-electrode assembly were discussed.

  15. 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.

  16. 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

  17. Molten carbonate fuel cell cathodes. Improvement of the electrocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Escudero, M.J.; Daza, L. [Dpto. Energia, CIEMAT, Av. Complutense 22, 28040 Madrid (Spain); Rodrigo, T. [Instituto de Catalisis y Petroleoquimica, CSIC, Campus Cantoblanco, 28049 Madrid (Spain)

    2005-10-30

    The purpose of this work is to improve the electrocatalytic activity of Li-Ni mixed oxides by the addition of rare earth oxides (cerium or lanthanum). The influence of cerium and lanthanum on the electrocatalytic activity of these compounds was investigated by means of electrochemical impedance spectroscopy (EIS). The stability of these compounds was studied in a mixture of 62% lithium carbonate and 38% potassium carbonate at high temperature under an atmosphere rich in carbon dioxide to accelerate their dissolution. The morphology and the crystalline structure of the samples were not affected by the incorporation of cerium or lanthanum. The samples impregnated with CeO{sub 2} or La{sub 2}O{sub 3} showed lower resistance to charger-transfer processes than the sample without earth rare oxides. Both cerium and lanthanum improved the charger-transfer processes for oxygen reduction in an atmosphere rich in carbon dioxide. The reason may be due to cerium oxide acting as oxygen donor, and lanthanum oxide capturing CO{sub 2}, and the partial pressure of carbon dioxide on the surface of electrode.

  18. Emerging engineering principles for yield improvement in microbial cell design.

    Science.gov (United States)

    Comba, Santiago; Arabolaza, Ana; Gramajo, Hugo

    2012-01-01

    Metabolic Engineering has undertaken a rapid transformation in the last ten years making real progress towards the production of a wide range of molecules and fine chemicals using a designed cellular host. However, the maximization of product yields through pathway optimization is a constant and central challenge of this field. Traditional methods used to improve the production of target compounds from engineered biosynthetic pathways in non-native hosts include: codon usage optimization, elimination of the accumulation of toxic intermediates or byproducts, enhanced production of rate-limiting enzymes, selection of appropriate promoter and ribosome binding sites, application of directed evolution of enzymes, and chassis re-circuit. Overall, these approaches tend to be specific for each engineering project rather than a systematic practice based on a more generalizable strategy. In this mini-review, we highlight some novel and extensive approaches and tools intended to address the improvement of a target product formation, founded in sophisticated principles such as dynamic control, pathway genes modularization, and flux modeling.

  19. EMERGING ENGINEERING PRINCIPLES FOR YIELD IMPROVEMENT IN MICROBIAL CELL DESIGN

    Directory of Open Access Journals (Sweden)

    Santiago Comba

    2012-10-01

    Full Text Available Metabolic Engineering has undertaken a rapid transformation in the last ten years making real progress towards the production of a wide range of molecules and fine chemicals using a designed cellular host. However, the maximization of product yields through pathway optimization is a constant and central challenge of this field. Traditional methods used to improve the production of target compounds from engineered biosynthetic pathways in non-native hosts include: codon usage optimization, elimination of the accumulation of toxic intermediates or byproducts, enhanced production of rate-limiting enzymes, selection of appropriate promoter and ribosome binding sites, application of directed evolution of enzymes, and chassis re-circuit. Overall, these approaches tend to be specific for each engineering project rather than a systematic practice based on a more generalizable strategy. In this mini-review, we highlight some novel and extensive approaches and tools intended to address the improvement of a target product formation, founded in sophisticated principles such as dynamic control, pathway genes modularization, and flux modeling.

  20. 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

  1. Improving the efficiency of multisensory integration in older adults: audio-visual temporal discrimination training reduces susceptibility to the sound-induced flash illusion.

    Science.gov (United States)

    Setti, Annalisa; Stapleton, John; Leahy, Daniel; Walsh, Cathal; Kenny, Rose Anne; Newell, Fiona N

    2014-08-01

    From language to motor control, efficient integration of information from different sensory modalities is necessary for maintaining a coherent interaction with the environment. While a number of training studies have focused on training perceptual and cognitive function, only very few are specifically targeted at improving multisensory processing. Discrimination of temporal order or coincidence is a criterion used by the brain to determine whether cross-modal stimuli should be integrated or not. In this study we trained older adults to judge the temporal order of visual and auditory stimuli. We then tested whether the training had an effect in reducing susceptibility to a multisensory illusion, the sound induced flash illusion. Improvement in the temporal order judgement task was associated with a reduction in susceptibility to the illusion, particularly at longer Stimulus Onset Asynchronies, in line with a more efficient multisensory processing profile. The present findings set the ground for more broad training programs aimed at improving older adults׳ cognitive performance in domains in which efficient temporal integration across the senses is required.

  2. Modeling human retinal development with patient-specific induced pluripotent stem cells reveals multiple roles for visual system homeobox 2.

    Science.gov (United States)

    Phillips, M Joseph; Perez, Enio T; Martin, Jessica M; Reshel, Samantha T; Wallace, Kyle A; Capowski, Elizabeth E; Singh, Ruchira; Wright, Lynda S; Clark, Eric M; Barney, Patrick M; Stewart, Ron; Dickerson, Sarah J; Miller, Michael J; Percin, E Ferda; Thomson, James A; Gamm, David M

    2014-06-01

    Human induced pluripotent stem cells (hiPSCs) have been shown to differentiate along the retinal lineage in a manner that mimics normal mammalian development. Under certain culture conditions, hiPSCs form optic vesicle-like structures (OVs), which contain proliferating progenitors capable of yielding all neural retina (NR) cell types over time. Such observations imply conserved roles for regulators of retinogenesis in hiPSC-derived cultures and the developing embryo. However, whether and to what extent this assumption holds true has remained largely uninvestigated. We examined the role of a key NR transcription factor, visual system homeobox 2 (VSX2), using hiPSCs derived from a patient with microphthalmia caused by an R200Q mutation in the VSX2 homeodomain region. No differences were noted between (R200Q)VSX2 and sibling control hiPSCs prior to OV generation. Thereafter, (R200Q)VSX2 hiPSC-OVs displayed a significant growth deficit compared to control hiPSC-OVs, as well as increased production of retinal pigmented epithelium at the expense of NR cell derivatives. Furthermore, (R200Q)VSX2 hiPSC-OVs failed to produce bipolar cells, a distinctive feature previously observed in Vsx2 mutant mice. (R200Q)VSX2 hiPSC-OVs also demonstrated delayed photoreceptor maturation, which could be overcome via exogenous expression of wild-type VSX2 at early stages of retinal differentiation. Finally, RNAseq analysis on isolated hiPSC-OVs implicated key transcription factors and extracellular signaling pathways as potential downstream effectors of VSX2-mediated gene regulation. Our results establish hiPSC-OVs as versatile model systems to study retinal development at stages not previously accessible in humans and support the bona fide nature of hiPSC-OV-derived retinal progeny.

  3. Improvement of visualization efficiency for the nondestructive inspection image of internal defects in plate type nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seung Kyu; Park, Nak Kyu; Baik, Sung Hoon; Lee, Yoon Sang; Cheong, Yong Moo [KAERI, Daejeon (Korea, Republic of); Kang, Young June [Chonbuk National Univ., Chonju (Korea, Republic of)

    2012-10-15

    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.

  4. 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

    of the 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......High-definition OCT (HD-OCT) is an innovative technique based on the principle of conventional OCT. Our objective was to test the resolution and image quality of HD-OCT in comparison with reflectance confocal microscopy (RCM) of healthy skin. Firstly, images have been made of a ultra......-high-resolution line-pair phantome with both systems. Secondly, we investigated 21 healthy volunteers of different phototypes with HD-OCT and RCM on volar forearm and compared the generated images. HD-OCT displays also differences depending on the skin phototype and anatomical site. The 3-μm lateral resolution...

  5. 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

  6. Visual Servoing for Optimization of Anticancer Drug Uptake in Human Breast Cancer Cells

    Science.gov (United States)

    2000-09-01

    tumor cells. Cancer Research. 57:1590-1596. DeVita , V. T., Jr. 1997. Cancer: principles and practice of oncology . Lippincott-Raven, Philadelphia. Ethier...vitro assays to select chemotherapy regimens tailored to the tumor of the individual patient is not new ( DeVita , 1997). A summary of clinical correlations...pooled from several individual studies ( DeVita , 1997). These authors have suggested that these assays be referred to as drug-response assays, rather than

  7. 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.

  8. Current techniques for visualizing RNA in cells [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Lilith V.J.C. Mannack

    2016-04-01

    Full Text Available Labeling RNA is of utmost interest, particularly in living cells, and thus RNA imaging is an emerging field. There are numerous methods relying on different concepts ranging from hybridization-based probes, over RNA-binding proteins to chemo-enzymatic modification of RNA. These methods have different benefits and limitations. This review aims to outline the current state-of-the-art techniques and point out their benefits and limitations.

  9. Improved solid oxide fuel cell performance with nanostructured electrolytes.

    Science.gov (United States)

    Chao, Cheng-Chieh; Hsu, Ching-Mei; Cui, Yi; Prinz, Fritz B

    2011-07-26

    Considerable attention has been focused on solid oxide fuel cells (SOFCs) due to their potential for providing clean and reliable electric power. However, the high operating temperatures of current SOFCs limit their adoption in mobile applications. To lower the SOFC operating temperature, we fabricated a corrugated thin-film electrolyte membrane by nanosphere lithography and atomic layer deposition to reduce the polarization and ohmic losses at low temperatures. The resulting micro-SOFC electrolyte membrane showed a hexagonal-pyramid array nanostructure and achieved a power density of 1.34 W/cm(2) at 500 °C. In the future, arrays of micro-SOFCs with high power density may enable a range of mobile and portable power applications.

  10. Metal-sulfur type cell having improved positive electrode

    Science.gov (United States)

    Dejonghe, Lutgard C.; Visco, Steven J.; Mailhe, Catherine C.; Armand, Michel B.

    1988-03-01

    A novel metal-sulfur type cell operable at a temperature of 200 C or less with an energy density of 150 Whrs/Kg or better is disclosed characterized by an organo-sulfur cathode formed from an organic-sulfur compound having the general formula, in its charged state, of (R(S) sub y) n wherein y = 1 to 6; n = 2 to 20; and R is one or more different aliphatic or aromatic organic moieties having 1 to 20 carbon atoms, which may include one or more oxygen, sulfur, or nitrogen heteroatoms when R comprises one or more aromatic rings, or one or more oxygen, sulfur, nitrogen, or fluorine atoms associated with the chain when R comprises an aliphatic chain, wherein the aliphatic group may be linear or branched, saturated or unsaturated, and wherein either the aliphatic chain or the aromatic ring may have substituted groups thereon.

  11. Miniaturization of photoacoustic cell for smart endoscope to improve sensitivity.

    Science.gov (United States)

    Wadamori, Naoki

    2014-01-01

    Ultrathin endoscopes, such as transnasal endo-scopes, have been developed to alleviate discomfort during diagnosis and therapy. However, their application to optional diagnostics is limited since many optional diagnostic instruments are designed to fit through larger side channels. The aim of this study was to develop a smart endoscope that can obtain various diagnoses based on photoacoustic spectroscopy. The photoacoustic process comprises complex energy conversions involving optical, thermal, and elastic processes. This work focused on the scaling potential of photoacoustic sensors. Photoacoustic sensors with two different volumes were developed, and the amplitudes and frequency responses of the photoacoustic signals for silicone rubbers with six different Young's moduli were investigated. The results showed that photoacoustic signals can be enhanced by reducing the volumes of the sensors. Embedding a miniaturized photoacoustic sensor in an endoscope was confirmed to improve the sensitivity.

  12. [Lymph node preparation in colorectal cancer. Ex vivo methylene blue injection as a novel technique to improve lymph node visualization].

    Science.gov (United States)

    Märkl, B; Kerwel, T; Jähnig, H; Anthuber, M; Arnholdt, H

    2008-07-01

    The UICC requires investigation of a minimum of 12 lymph nodes for adequate lymph node staging in colorectal cancer. Despite that, many authors recommend investigation of a larger number, and different techniques, such as fat clearance, have therefore been developed. In this study we introduce a novel technique involving ex vivo lymph node staining with intraarterial methylene blue injection in colon cancer. We compared 14 cases in which methylene injection was used with 14 cases from our records in which conventional investigation techniques were applied. The lymph node harvest differed highly significantly (pmethylene blue group and the unstained group, respectively. The largest difference occurred in the size group 2-4 mm (191 vs 70 lymph nodes). In 6 cases in the unstained group additional embedding of fatty tissue was necessary to reach an adequate number of investigated lymph nodes. Methylene blue injection is a novel and highly effective method that will improve lymph node preparation in colorectal cancer.

  13. Valproic acid improves second-line regimen of small cell lung carcinoma in preclinical models

    Directory of Open Access Journals (Sweden)

    Roland Hubaux

    2015-10-01

    Full Text Available With 5-year survival rates below 5%, small cell lung carcinoma (SCLC has very poor prognosis and requires improved therapies. Despite an excellent overall response to first-line therapy, relapses are frequent and further treatments are disappointing. The goal of the study was to improve second-line therapy of SCLC. The effect of chemotherapeutic agents was evaluated in cell lines (apoptosis, reactive oxygen species, and RNA and protein expression and in mouse models (tumour development. We demonstrate here that valproic acid, a histone deacetylase inhibitor, improves the efficacy of a second-line regimen (vindesine, doxorubicin and cyclophosphamide in SCLC cells and in mouse models. Transcriptomic profiling integrating microRNA and mRNA data identifies key signalling pathways in the response of SCLC cells to valproic acid, opening new prospects for improved therapies.

  14. 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.

  15. Direct visualization of neo-vessel formation following peripheral injection of bone marrow derived CD34+ cells in experimental myocardial damage.

    Science.gov (United States)

    Ciulla, M M; Ferrero, S; Gianelli, U; Paliotti, R; Magrini, F; Braidotti, P

    2007-01-01

    The definitive fate of peripherally injected PKH26 labelled bone marrow mononuclear cells expressing the CD34+ antigen following experimental myocardial cryodamage in rats (n=10) has been examined by direct visualization on photoconverted light and electron microscopy images. One week after the injection in each rat of about 150,000 CD34+ cells early stage PKH26+ vascular structures were localized in the infarcted areas, suggesting that a potential benefit of this therapeutic approach consists in the regeneration of the vasculature.

  16. 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.

  17. Efficiency improvement of dye-sensitized tandem solar cell by increasing the photovoltage of the back sub-cell

    Energy Technology Data Exchange (ETDEWEB)

    Fan Shengqiang [Department of Advanced Materials Chemistry, Korea University, Jochiwon, Chungnam 339-700 (Korea, Republic of); Department of Applied Chemistry, School of Science, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Fang Baizeng, E-mail: shengqiang_fan@sohu.co [Department of Advanced Materials Chemistry, Korea University, Jochiwon, Chungnam 339-700 (Korea, Republic of); Choi, Hyunbong; Paik, Sanghyun; Kim, Chulwoo; Jeong, Ban-Seok; Kim, Jeum-Jong [Department of Advanced Materials Chemistry, Korea University, Jochiwon, Chungnam 339-700 (Korea, Republic of); Ko, Jaejung, E-mail: jko@korea.ac.k [Department of Advanced Materials Chemistry, Korea University, Jochiwon, Chungnam 339-700 (Korea, Republic of)

    2010-06-01

    In tandem-structured dye-sensitized solar cell (DSSC) composed of two parallel-connected sub-cells, the photovoltage (V{sub oc}) generated by the back sub-cell is usually rather low, resulting in low V{sub oc} and conversion efficiency (eta) of the tandem cell. To solve this issue, two simple but very efficient strategies, namely, the filling of Li{sup +}-absent electrolyte and/or coating Al{sub 2}O{sub 3} on TiO{sub 2} electrode surface in the back sub-cell, were explored to enhance the V{sub oc} of the back sub-cell and hence that of the tandem cell. The former strategy was expected to heighten the energy level of TiO{sub 2} conduction band, and the latter one to retard the charge recombination. The photovoltaic performance measurements reveal that in the both cases, although there was a slight decrease in the photocurrent (J{sub sc}), an obvious rise in the V{sub oc} was achieved for the tandem cells, leading to significant improvements in eta of the tandem cells. Compared to the individual organic dye-sensitized solar cell (the highest eta is 7.58%), the tandem cell with two organic dyes having complementary absorption spectra demonstrates an improved efficiency of up to 8.33% by a combinational application of Li{sup +}-absent electrolyte and Al{sub 2}O{sub 3} overcoat. The results presented in this study highlight that the efficiency of a parallel-connected tandem-structured DSSC can be improved significantly through enhancing the photovoltage of the back sub-cell, which is first time reported.

  18. Intermittent energy harvesting improves the performance of microbial fuel cells.

    Science.gov (United States)

    Dewan, Alim; Beyenal, Haluk; Lewandowski, Zbigniew

    2009-06-15

    In this study, we compare the efficiencies of harvesting energy from microbial fuel cells (MFC) using two modes of operation: (1) continuous-passing the current through an electrical load-and (2) intermittent-first accumulating the energy in a capacitor and then discharging it through the load. Each of these two modes of operation has advantages and disadvantages: the first mode of operation allows the continuous powering of low-power-consuming devices, and the second mode of operation allows the intermittent powering of high-power-consuming devices. We used a two-compartment MFC: in the anodic compartment, Shewanella oneidensis MR-1 was grown using lactate as an electron donor, whereas in the cathodic compartment we used an electrode made of manganese-based catalyzed carbon bonded to a current-collecting screen made of platinum mesh and oxygen as the electron acceptor. The maximum power generated by harvesting energy intermittently was 152 microW, which is 111% higher than the 72 microW generated by harvesting the energy continuously. We conclude that in the operation of MFCs it is beneficial to harvest the energy intermittently. This not only allows the powering of external devices of high power consumption but also allows generating power with greater energy efficiency than does harvesting the energy continuously.

  19. Improved polythiophene conductivity by thermal crosslinking for solar cell applications

    Science.gov (United States)

    Gearba, I. R.; Nam, C.-Y.; Pindak, R.; Black, C. T.

    2009-03-01

    Organic photovoltaic device power conversion efficiencies are limited in part by low charge mobility within the constituent active layer. For example, the p-type polythiophene polymers used in the highest efficiency organic photovoltaic devices have transverse hole mobilities of only 10-4-10-5 cm^2/V-s, despite showing significantly higher values (˜0.1 cm^2/V-s) in a lateral FET geometry. This mobility anisotropy is caused by poor overlap of π-π orbitals in the transverse direction, which impedes charge hopping between polymer chains. We have improved the transverse hole conductivity by as much as three times by incorporating the radical initiator di-tert-butyl peroxide into polythiophene thin films. The initiator promotes thermal crosslinking upon annealing at 170C. Crosslinked polythiophene films maintain a similar absorption spectrum to the uncrosslinked material. Grazing incidence X-ray measurements correlate film structural changes to the measured electronic properties, and reveal two possible mechanisms for increased π-π overlap in crosslinked films. We have increased the power conversion efficiency of planar photovoltaic devices composed of p-type polythiophene and n-type C60 by approx three times (from 0.09% to 0.27%) by crosslinking the polythiophene material. Moreover, crosslinked polythiophene films are rendered insoluble and thus amenable to the further material processing.

  20. Cell surface glycan engineering of neural stem cells augments neurotropism and improves recovery in a murine model of multiple sclerosis

    KAUST Repository

    Merzaban, Jasmeen S.

    2015-09-13

    Neural stem cell (NSC)-based therapies offer potential for neural repair in central nervous system (CNS) inflammatory and degenerative disorders. Typically, these conditions present with multifocal CNS lesions making it impractical to inject NSCs locally, thus mandating optimization of vascular delivery of the cells to involved sites. Here, we analyzed NSCs for expression of molecular effectors of cell migration and found that these cells are natively devoid of E-selectin ligands. Using glycosyltransferase-programmed stereosubstitution (GPS), we glycan engineered the cell surface of NSCs ("GPS-NSCs") with resultant enforced expression of the potent E-selectin ligand HCELL (hematopoietic cell E-/L-selectin ligand) and of an E-selectin-binding glycoform of neural cell adhesion molecule ("NCAM-E"). Following intravenous (i.v.) injection, short-term homing studies demonstrated that, compared with buffer-treated (control) NSCs, GPS-NSCs showed greater neurotropism. Administration of GPS-NSC significantly attenuated the clinical course of experimental autoimmune encephalomyelitis (EAE), with markedly decreased inflammation and improved oligodendroglial and axonal integrity, but without evidence of long-term stem cell engraftment. Notably, this effect of NSC is not a universal property of adult stem cells, as administration of GPS-engineered mouse hematopoietic stem/progenitor cells did not improve EAE clinical course. These findings highlight the utility of cell surface glycan engineering to boost stem cell delivery in neuroinflammatory conditions and indicate that, despite the use of a neural tissue-specific progenitor cell population, neural repair in EAE results from endogenous repair and not from direct, NSC-derived cell replacement.

  1. NF-Protocadherin Regulates Retinal Ganglion Cell Axon Behaviour in the Developing Visual System.

    Directory of Open Access Journals (Sweden)

    Louis C Leung

    Full Text Available Cell adhesion molecules play a central role in mediating axonal tract development within the nascent nervous system. NF-protocadherin (NFPC, a member of the non-clustered protocadherin family, has been shown to regulate retinal ganglion cell (RGC axon and dendrite initiation, as well as influencing axonal navigation within the mid-optic tract. However, whether NFPC mediates RGC axonal behaviour at other positions within the optic pathway remains unclear. Here we report that NFPC plays an important role in RGC axonogenesis, but not in intraretinal guidance. Moreover, axons with reduced NFPC levels exhibit insensitivity to Netrin-1, an attractive guidance cue expressed at the optic nerve head. Netrin-1 induces rapid turnover of NFPC localized to RGC growth cones, suggesting that the regulation of NFPC protein levels may underlie Netrin-1-mediated entry of RGC axons into the optic nerve head. At the tectum, we further reveal a function for NFPC in controlling RGC axonal entry into the final target area. Collectively, our results expand our understanding of the role of NFPC in RGC guidance and illustrate that this adhesion molecule contributes to axon behaviour at multiple points in the optic pathway.

  2. Dynamic Visualization of mTORC1 Activity in Living Cells

    Science.gov (United States)

    Zhou, Xin; Clister, Terri L.; Lowry, Pamela R.; Seldin, Marcus M.; Wong, G. William; Zhang, Jin

    2015-01-01

    Summary The mechanistic target of rapamycin complex 1 (mTORC1) senses diverse signals to regulate cell growth and metabolism. It has become increasingly clear that mTORC1 activity is regulated in time and space inside the cell, but direct interrogation of such spatiotemporal regulation is challenging. Here we describe a genetically encoded mTORC1 activity reporter (TORCAR) that exhibits a change in FRET in response to phosphorylation by mTORC1. Co-imaging mTORC1 activity and calcium dynamics revealed that a growth factor-induced calcium transient contributes to mTORC1 activity. Dynamic activity maps generated using subcellularly targeted TORCAR uncovered mTORC1 activity not only in cytosol and at the lysosome but also in nucleus and at the plasma membrane. Furthermore, a wide distribution of activities was observed upon growth factor stimulation, whereas leucine ester, an amino acid surrogate, induces more compartmentalized activities at the lysosome and in nucleus. Thus, mTORC1 activities are spatiotemporally regulated in a signal-specific manner. PMID:25772363

  3. Dynamic Visualization of mTORC1 Activity in Living Cells

    Directory of Open Access Journals (Sweden)

    Xin Zhou

    2015-03-01

    Full Text Available The mechanistic target of rapamycin complex 1 (mTORC1 senses diverse signals to regulate cell growth and metabolism. It has become increasingly clear that mTORC1 activity is regulated in time and space inside the cell, but direct interrogation of such spatiotemporal regulation is challenging. Here, we describe a genetically encoded mTORC1 activity reporter (TORCAR that exhibits a change in FRET in response to phosphorylation by mTORC1. Co-imaging mTORC1 activity and calcium dynamics revealed that a growth-factor-induced calcium transient contributes to mTORC1 activity. Dynamic activity maps generated with the use of subcellularly targeted TORCAR uncovered mTORC1 activity not only in cytosol and at the lysosome but also in the nucleus and at the plasma membrane. Furthermore, a wide distribution of activities was observed upon growth factor stimulation, whereas leucine ester, an amino acid surrogate, induces more compartmentalized activities at the lysosome and in the nucleus. Thus, mTORC1 activities are spatiotemporally regulated in a signal-specific manner.

  4. Live-Cell Visualization of Pre-mRNA Splicing with Single-Molecule Sensitivity

    Directory of Open Access Journals (Sweden)

    Robert M. Martin

    2013-09-01

    Full Text Available Removal of introns from pre-messenger RNAs (pre-mRNAs via splicing provides a versatile means of genetic regulation that is often disrupted in human diseases. To decipher how splicing occurs in real time, we directly examined with single-molecule sensitivity the kinetics of intron excision from pre-mRNA in the nucleus of living human cells. By using two different RNA labeling methods, MS2 and λN, we show that β-globin introns are transcribed and excised in 20–30 s. Furthermore, we show that replacing the weak polypyrimidine (Py tract in mouse immunoglobulin μ (IgM pre-mRNA by a U-rich Py decreases the intron lifetime, thus providing direct evidence that splice-site strength influences splicing kinetics. We also found that RNA polymerase II transcribes at elongation rates ranging between 3 and 6 kb min−1 and that transcription can be rate limiting for splicing. These results have important implications for a mechanistic understanding of cotranscriptional splicing regulation in the live-cell context.

  5. Improved Structure and Function in Autosomal Recessive Polycystic Rat Kidneys with Renal Tubular Cell Therapy.

    Science.gov (United States)

    Kelly, K J; Zhang, Jizhong; Han, Ling; Kamocka, Malgorzata; Miller, Caroline; Gattone, Vincent H; Dominguez, Jesus H

    2015-01-01

    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.

  6. 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.

  7. 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.

  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.

  9. Visual art and visual perception

    NARCIS (Netherlands)

    Koenderink, Jan J.

    2015-01-01

    Visual art and visual perception ‘Visual art’ has become a minor cul-de-sac orthogonal to THE ART of the museum directors and billionaire collectors. THE ART is conceptual, instead of visual. Among its cherished items are the tins of artist’s shit (Piero Manzoni, 1961, Merda d’Artista) “worth their

  10. In vivo targeting of antigens to maturing dendritic cells via the DEC-205 receptor improves T cell vaccination.

    Science.gov (United States)

    Bonifaz, Laura C; Bonnyay, David P; Charalambous, Anna; Darguste, Dara I; Fujii, Shin-Ichiro; Soares, Helena; Brimnes, Marie K; Moltedo, Bruno; Moran, Thomas M; Steinman, Ralph M

    2004-03-15

    The prevention and treatment of prevalent infectious diseases and tumors should benefit from improvements in the induction of antigen-specific T cell immunity. To assess the potential of antigen targeting to dendritic cells to improve immunity, we incorporated ovalbumin protein into a monoclonal antibody to the DEC-205 receptor, an endocytic receptor that is abundant on these cells in lymphoid tissues. Simultaneously, we injected agonistic alpha-CD40 antibody to mature the dendritic cells. We found that a single low dose of antibody-conjugated ovalbumin initiated immunity from the naive CD4+ and CD8+ T cell repertoire. Unexpectedly, the alphaDEC-205 antigen conjugates, given s.c., targeted to dendritic cells systemically and for long periods, and ovalbumin peptide was presented on MHC class I for 2 weeks. This was associated with stronger CD8+ T cell-mediated immunity relative to other forms of antigen delivery, even when the latter was given at a thousand times higher doses. In parallel, the mice showed enhanced resistance to an established rapidly growing tumor and to viral infection at a mucosal site. By better harnessing the immunizing functions of maturing dendritic cells, antibody-mediated antigen targeting via the DEC-205 receptor increases the efficiency of vaccination for T cell immunity, including systemic and mucosal resistance in disease models.

  11. 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.

  12. 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

  13. Combination therapy targeting both cancer stem-like cells and bulk tumor cells for improved efficacy of breast cancer treatment.

    Science.gov (United States)

    Wang, Tao; Narayanaswamy, Radhika; Ren, Huilan; Torchilin, Vladimir P

    2016-06-01

    Many types of tumors are organized in a hierarchy of heterogeneous cell populations. The cancer stem-like cells (CSCs) hypothesis suggests that tumor development and metastasis are driven by a minority population of cells, which are responsible for tumor initiation, growth and recurrences. The inability to efficiently eliminate CSCs during chemotherapy, together with CSCs being highly tumorigenic and invasive, may result in treatment failure due to cancer relapse and metastases. CSCs are emerging as a promising target for the development of translational cancer therapies. Ideal panacea for cancer would kill all malignant cells, including CSCs and bulk tumor cells. Since both chemotherapy and CSCs-specific therapy are insufficient to cure cancer, we propose combination therapy with CSCs-targeted agents and chemotherapeutics for improved breast cancer treatment. We generated in vitro mammosphere of 2 breast cancer cell lines, and demonstrated ability of mammospheres to grow and enrich cancer cells with stem-like properties, including self-renewal, multilineage differentiation and enrichment of cells expressing breast cancer stem-like cell biomarkers CD44(+)/CD24(-/low). The formation of mammospheres was significantly inhibited by salinomycin, validating its pharmacological role against the cancer stem-like cells. In contrast, paclitaxel showed a minimal effect on the proliferation and growth of breast cancer stem-like cells. While combination therapies of salinomycin with conventional chemotherapy (paclitaxel or lipodox) showed a potential to improve tumor cell killing, different subtypes of breast cancer cells showed different patterns in response to the combination therapies. While optimization of combination therapy is warranted, the design of combination therapy should consider phenotypic attributes of breast cancer types.

  14. 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...

  15. Efficiency Improvement of HIT Solar Cells on p-Type Si Wafers

    OpenAIRE

    Chun-You Wei; Chu-Hsuan Lin; Hao-Tse Hsiao; Po-Chuan Yang; Chih-Ming Wang; Yen-Chih Pan

    2013-01-01

    Single crystal silicon solar cells are still predominant in the market due to the abundance of silicon on earth and their acceptable efficiency. Different solar-cell structures of single crystalline Si have been investigated to boost efficiency; the heterojunction with intrinsic thin layer (HIT) structure is currently the leading technology. The record efficiency values of state-of-the art HIT solar cells have always been based on n-type single-crystalline Si wafers. Improving the efficiency ...

  16. KSR-based medium improves the generation of high-quality mouse iPS cells.

    Science.gov (United States)

    Liu, Kai; Wang, Fang; Ye, Xiaoying; Wang, Lingling; Yang, Jiao; Zhang, Jingzhuo; Liu, Lin

    2014-01-01

    Induced pluripotent stem (iPS) cells from somatic cells have great potential for regenerative medicine. The efficiency in generation of iPS cells has been significantly improved in recent years. However, the generation of high-quality iPS cells remains of high interest. Consistently, we demonstrate that knockout serum replacement (KSR)-based medium accelerates iPS cell induction and improves the quality of iPS cells, as confirmed by generation of chimeras and all iPS cell-derived offspring with germline transmission competency. Both alkaline phosphatase (AP) activity assay and expression of Nanog have been used to evaluate the efficiency of iPS cell induction and formation of ES/iPS cell colonies; however, appropriate expression of Nanog frequently indicates the quality of ES/iPS cells. Interestingly, whereas foetal bovine serum (FBS)-based media increase iPS cell colony formation, as revealed by AP activity, KSR-based media increase the frequency of iPS cell colony formation with Nanog expression. Furthermore, inhibition of MAPK/ERK by a specific inhibitor, PD0325901, in KSR- but not in FBS-based media significantly increases Nanog-GFP+ iPS cells. In contrast, addition of bFGF in KSR-based media decreases proportion of Nanog-GFP+ iPS cells. Remarkably, PD can rescue Nanog-GFP+ deficiency caused by bFGF. These data suggest that MAPK/ERK pathway influences high quality mouse iPS cells and that KSR- and PD-based media could enrich homogeneous authentic pluripotent stem cells.

  17. Adoptive T-cell therapy improves treatment of canine non–Hodgkin lymphoma post chemotherapy

    Science.gov (United States)

    O'Connor, Colleen M.; Sheppard, Sabina; Hartline, Cassie A.; Huls, Helen; Johnson, Mark; Palla, Shana L.; Maiti, Sourindra; Ma, Wencai; Davis, R. Eric; Craig, Suzanne; Lee, Dean A.; Champlin, Richard; Wilson, Heather; Cooper, Laurence J. N.

    2012-01-01

    Clinical observations reveal that an augmented pace of T-cell recovery after chemotherapy correlates with improved tumor-free survival, suggesting the add-back of T cells after chemotherapy may improve outcomes. To evaluate adoptive immunotherapy treatment for B-lineage non-Hodgkin lymphoma (NHL), we expanded T cells from client-owned canines diagnosed with NHL on artificial antigen presenting cells (aAPC) in the presence of human interleukin (IL)-2 and IL-21. Graded doses of autologous T cells were infused after CHOP chemotherapy and persisted for 49 days, homed to tumor, and significantly improved survival. Serum thymidine kinase changes predicted T-cell engraftment, while anti-tumor effects correlated with neutrophil-to-lymphocyte ratios and granzyme B expression in manufactured T cells. Therefore, chemotherapy can be used to modulate infused T-cell responses to enhance anti-tumor effects. The companion canine model has translational implications for human immunotherapy which can be readily exploited since clinical-grade canine and human T cells are propagated using identical approaches. PMID:22355761

  18. Improved Power Conversion Efficiency of Inverted Organic Solar Cells by Incorporating Au Nanorods into Active Layer.

    Science.gov (United States)

    He, Yeyuan; Liu, Chunyu; Li, Jinfeng; Zhang, Xinyuan; Li, Zhiqi; Shen, Liang; Guo, Wenbin; Ruan, Shengping

    2015-07-29

    This Research Article describes a cooperative plasmonic effect on improving the performance of organic solar cells. When Au nanorods(NRs) are incorporated into the active layers, the designed project shows superior enhanced light absorption behavior comparing with control devices, which leads to the realization of organic solar cell with power conversion efficiency of 6.83%, accounting for 18.9% improvement. Further investigations unravel the influence of plasmonic nanostructures on light trapping, exciton generation, dissociation, and charge recombination and transport inside the thin films devices. Moreover, the introduction of high-conductivity Au NRs improves electrical conductivity of the whole device, which contributes to the enhanced fill factor.

  19. Direct visualization of peptide/MHC complexes at the surface and in the intracellular compartments of cells infected in vivo by Leishmania major.

    Directory of Open Access Journals (Sweden)

    Eric Muraille

    Full Text Available Protozoa and bacteria infect various types of phagocytic cells including macrophages, monocytes, dendritic cells and eosinophils. However, it is not clear which of these cells process and present microbial antigens in vivo and in which cellular compartments parasite peptides are loaded onto Major Histocompatibility Complex molecules. To address these issues, we have infected susceptible BALB/c (H-2d mice with a recombinant Leishmania major parasite expressing a fluorescent tracer. To directly visualize the antigen presenting cells that present parasite-derived peptides to CD4+ T cells, we have generated a monoclonal antibody that reacts to an antigenic peptide derived from the parasite LACK antigen bound to I-Ad Major Histocompatibility Complex class II molecule. Immunogold electron microscopic analysis of in vivo infected cells showed that intracellular I-Ad/LACK complexes were present in the membrane of amastigote-containing phagosomes in dendritic cells, eosinophils and macrophages/monocytes. In both dendritic cells and macrophages, these complexes were also present in smaller vesicles that did not contain amastigote. The presence of I-Ad/LACK complexes at the surface of dendritic cells, but neither on the plasma membrane of macrophages nor eosinophils was independently confirmed by flow cytometry and by incubating sorted phagocytes with highly sensitive LACK-specific hybridomas. Altogether, our results suggest that peptides derived from Leishmania proteins are loaded onto Major Histocompatibility Complex class II molecules in the phagosomes of infected phagocytes. Although these complexes are transported to the cell surface in dendritic cells, therefore allowing the stimulation of parasite-specific CD4+ T cells, this does not occur in other phagocytic cells. To our knowledge, this is the first study in which Major Histocompatibility Complex class II molecules bound to peptides derived from a parasite protein have been visualized within and

  20. 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

  1. 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.

  2. Improved performance in GaInNAs solar cells by hydrogen passivation

    Science.gov (United States)

    Fukuda, M.; Whiteside, V. R.; Keay, J. C.; Meleco, A.; Sellers, I. R.; Hossain, K.; Golding, T. D.; Leroux, M.; Al Khalfioui, M.

    2015-04-01

    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.

  3. Withania somnifera improves semen quality by combating oxidative stress and cell death and improving essential metal concentrations.

    Science.gov (United States)

    Shukla, Kamla Kant; Mahdi, Abbas Ali; Mishra, Vivek; Rajender, Singh; Sankhwar, Satya Narain; Patel, Devender; Das, Mukul

    2011-05-01

    This study investigated the effect of a 3-month treatment with Withania somnifera on apoptosis and intracellular reactive oxygen species (ROS) concentration of spermatozoa and the metal ions copper, zinc, iron and gold in seminal plasma from infertile men (normozoospermic, n=25; oligozoospermic, n=25; and asthenozoospermic, n=25). The apoptotic and necrotic cell distribution were analysed by annexin-V binding and propidium iodide uptake using flow cytometry. ROS generation was measured by fluorescence intensity and metal ions were analysed by atomic absorption spectrophotometry. The results demonstrated that, prior to treatment, sperm apoptosis and intracellular ROS concentrations were significantly higher in all groups of infertile men compared with controls (PZn(2+), Fe(2+) and Au(2+) in seminal plasma were lower. Treatment with W. somnifera significantly reduced apoptosis in normozoospermic and oligozoospermic men and ROS concentrations in oligozoospermic and asthenozoospermic men (all Pspermatozoa from infertile men. Before and following treatment, sperm apoptosis and concentrations of intracellular ROS and the metal ions copper, zinc, iron, and gold in seminal plasma were measured. The apoptotic and necrotic cell distribution were analysed by annexin-V binding and propidium iodide uptake using flow cytometry. ROS generation was measured by fluorescence intensity and metal ions were analysed by atomic absorption spectrophotometry. The results demonstrated that prior, to treatment, apoptosis and intracellular ROS concentrations were significantly higher in all groups of infertile men compared with controls. Similarly, the concentrations of the essential metal ions Cu(2+), Zn(2+), Fe(2+) and Au(2+) in seminal plasma were lower. Treatment with W. somnifera significantly reduced apoptosis and ROS concentrations and improved metal ion concentrations in infertile subjects. It is concluded that W. somnifera improves semen quality by reducing oxidative stress and cell

  4. In Vivo Targeting of Antigens to Maturing Dendritic Cells via the DEC-205 Receptor Improves T Cell Vaccination

    Science.gov (United States)

    Bonifaz, Laura C.; Bonnyay, David P.; Charalambous, Anna; Darguste, Dara I.; Fujii, Shin-Ichiro; Soares, Helena; Brimnes, Marie K.; Moltedo, Bruno; Moran, Thomas M.; Steinman, Ralph M.

    2004-01-01

    The prevention and treatment of prevalent infectious diseases and tumors should benefit from improvements in the induction of antigen-specific T cell immunity. To assess the potential of antigen targeting to dendritic cells to improve immunity, we incorporated ovalbumin protein into a monoclonal antibody to the DEC-205 receptor, an endocytic receptor that is abundant on these cells in lymphoid tissues. Simultaneously, we injected agonistic α-CD40 antibody to mature the dendritic cells. We found that a single low dose of antibody-conjugated ovalbumin initiated immunity from the naive CD4+ and CD8+ T cell repertoire. Unexpectedly, the αDEC-205 antigen conjugates, given s.c., targeted to dendritic cells systemically and for long periods, and ovalbumin peptide was presented on MHC class I for 2 weeks. This was associated with stronger CD8+ T cell–mediated immunity relative to other forms of antigen delivery, even when the latter was given at a thousand times higher doses. In parallel, the mice showed enhanced resistance to an established rapidly growing tumor and to viral infection at a mucosal site. By better harnessing the immunizing functions of maturing dendritic cells, antibody-mediated antigen targeting via the DEC-205 receptor increases the efficiency of vaccination for T cell immunity, including systemic and mucosal resistance in disease models. PMID:15024047

  5. An improved method for culturing cerebellar Purkinje cells with differentiated dendrites under a mixed monolayer setting.

    Science.gov (United States)

    Furuya, S; Makino, A; Hirabayashi, Y

    1998-11-01

    We report here a novel cell culture protocol which facilitates in vitro survival and dendritic differentiation of cerebellar Purkinje cells in a monolayer, mixed culture setting. We found that the type of culture medium is a critical factor for the maintenance of these cells. Purkinje cells present in the single cell suspension of embryonic rat cerebellum were best maintained in a medium based on Dulbecco's modified Eagle's medium (DMEM)/F-12 without the addition of known neurotrophic factors. These cells maintained in DMEM/F-12-based media displayed an approximately 2.5-3.5-fold increase in survival compared with cells maintained in the widely used Basal Medium Eagle's (BME)-based serum-free culture medium with the same supplements. This novel protocol permits not only enhanced survival but also accelerated, improved dendritic differentiation of these cells. Purkinje cells developed highly branched spiny dendrites by 14-16 days in vitro, which matches the time course of the dendritic growth of these cells in vivo. The Purkinje cells expressed metabotropic glutamate receptor 1alpha in the cell bodies and branched dendrites, and the intradendritic calcium concentration increased when trans-ACPD, a selective agonist of this receptor, was applied. This novel protocol allows the development of functional branched dendrites and therefore is useful for electrophysiological and ion-imaging studies on dendrites of Purkinje cells grown in vitro.

  6. [Three photons quantum-cutting system on the rear surface of cells to improve the efficiencies of solar cells].

    Science.gov (United States)

    Yao, Wen-ting; Chen, Xiao-bo; Cheng, Huan-li; Zhou, Gu; Deng, Zhi-wei; Li, Yong-liang; Yan, Da-dong; Peng, Fang-lin

    2015-02-01

    The authors present a solar cell model with a three photons quantum-cutting system on the rear surface, then the method of calculation of limiting efficiencies was used to get the maximum efficiency 58.58% at the band gap Eg=0.9315 eV, and in contrast with two-photons quantum-cutting system, it is greatly improved. The result can prove that the three-photons quantum-cutting has a great sense to improve the efficiencies of solar cells. It is the exciting development for us to find out the useful luminescence materials to get the high efficiency.

  7. Improving poor fill factors for solar cells via light-induced plating

    Institute of Scientific and Technical Information of China (English)

    Xing Zhao; Jia Rui; Ding Wuchang; Meng Yanlong; Jin Zhi; Liu Xinyu

    2012-01-01

    Silicon solar cells are prepared following the conventional fabrication processes,except for the metallization firing process.The cells are divided into two groups with higher and lower fill factors,respectively.After light-induced plating (LIP),the fill factors of the solar cells in both groups with different initial values reach the same level.Scanning electron microscope (SEM) images are taken under the bulk silver electrodes,which prove that the improvement for cells with a poor factor after LIP should benefit from sufficient exploitation of the high density silver crystals formed during the firing process.Moreover,the application of LIP to cells with poor electrode contact performance,such as nanowire cells and radial junction solar cells,is proposed.

  8. A Transmit Beamforming and Nulling Approach with Distributed Scheduling to Improve Cell Edge Throughput

    Directory of Open Access Journals (Sweden)

    Wendy C. Wong

    2010-01-01

    Full Text Available We propose a transmit scheme for WiMAX systems, where multiple base stations (BSs employ downlink transmit beamforming and nulling for interference mitigation, with minimal coordination amongst BSs. This scheme improves system throughput and robustness, by increasing cell edge and overall cell throughputs by 68% and 19%, respectively, and by delivering improvement for mobile speed up to 60 km/h. First, cell edge users suffering from severe interferences are identified. Next, the RRM unit allocates resource to serving cell edge users only. BSs will schedule to serve their cell edge users independently using the allocated resources by the RRM. A special uplink sounding region is designed for BSs to learn the interference environment and form proper beams and nulls. The nulls formed towards users served by other BSs reduced interference from a BS towards these users and is the basic building block of our algorithm.

  9. Numerical simulations for the effiency improvement of hybrid dye-microcrystalline silicon pin-solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Burdorf, Sven; Bauer, Gottfried Heinrich; Brueggemann, Rudolf [Institut fuer Physik, Carl von Ossietzky Universitaet, Oldenburg (Germany)

    2011-07-01

    Hybrid solar cells consisting of dye sensitizers incorporated in the i-layer of microcrystalline silicon pin solar cell have been proposed and even recently processed. The dye sensitizer molecules are embedded in the matrix and enhance the overall absorption of the dye-matrix system due to their high absorption coefficient in the spectral range interesting for photovoltaic applications. However, the charge transport properties of dyes are quite poor. Microcrystalline silicon on the other hand has acceptable charge transport properties, while the absorption, given a layer thickness in the micron range, is relatively poor. This contribution investigates the effiency improvement of hybrid dye-microcrystalline solar cells compared to pure microcrystalline solar cells by simulation. The results indicate that, under optimal conditions, the effiency can be improved by more than 20 % compared to a pure microcrystalline silicon cell. The thickness reduction for the hybrid system can be as large as 50 % for the same effiency.

  10. Improved antibody production in Chinese hamster ovary cells by ATF4 overexpression.

    Science.gov (United States)

    Haredy, Ahmad M; Nishizawa, Akitoshi; Honda, Kohsuke; Ohya, Tomoshi; Ohtake, Hisao; Omasa, Takeshi

    2013-12-01

    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 cell line. Clone CHO-ATF4-16 did not show any change in growth rate compared with the parental cells or mock-transfected CHO-DP12-SF cells. The expression levels of mRNAs encoding both the antibody heavy and light chains in the CHO-ATF4-16 clone were analyzed. This analysis showed that ATF4 overexpression improved the total production and specific production rate of antibody without affecting the mRNA transcription level. These results indicate that ATF4 overexpression is a promising method for improving recombinant IgG production in CHO cells.

  11. Basic aspects for improving the energy conversion efficiency of hetero-junction organic photovoltaic cells.

    Science.gov (United States)

    Ryuzaki, Sou; Onoe, Jun

    2013-01-01

    Hetero-junction organic photovoltaic (OPV) cells consisting of donor (D) and acceptor (A) layers have been regarded as next-generation PV cells, because of their fascinating advantages, such as lightweight, low fabrication cost, resource free, and flexibility, when compared to those of conventional PV cells based on silicon and semiconductor compounds. However, the power conversion efficiency (η) of the OPV cells has been still around 8%, though more than 10% efficiency has been required for their practical use. To fully optimize these OPV cells, it is necessary that the low mobility of carriers/excitons in the OPV cells and the open circuit voltage (V OC), of which origin has not been understood well, should be improved. In this review, we address an improvement of the mobility of carriers/excitons by controlling the crystal structure of a donor layer and address how to increase the V OC for zinc octaethylporphyrin [Zn(OEP)]/C60 hetero-junction OPV cells [ITO/Zn(OEP)/C60/Al]. It was found that crystallization of Zn(OEP) films increases the number of inter-molecular charge transfer (IMCT) excitons and enlarges the mobility of carriers and IMCT excitons, thus significantly improving the external quantum efficiency (EQE) under illumination of the photoabsorption band due to the IMCT excitons. Conversely, charge accumulation of photo-generated carriers in the vicinity of the donor/acceptor (D/A) interface was found to play a key role in determining the V OC for the OPV cells.

  12. Basic aspects for improving the energy conversion efficiency of hetero-junction organic photovoltaic cells

    Directory of Open Access Journals (Sweden)

    Sou Ryuzaki

    2013-07-01

    Full Text Available Hetero-junction organic photovoltaic (OPV cells consisting of donor (D and acceptor (A layers have been regarded as next-generation PV cells, because of their fascinating advantages, such as lightweight, low fabrication cost, resource free, and flexibility, when compared to those of conventional PV cells based on silicon and semiconductor compounds. However, the power conversion efficiency (η of the OPV cells has been still around 8%, though more than 10% efficiency has been required for their practical use. To fully optimize these OPV cells, it is necessary that the low mobility of carriers/excitons in the OPV cells and the open circuit voltage (VOC, of which origin has not been understood well, should be improved. In this review, we address an improvement of the mobility of carriers/excitons by controlling the crystal structure of a donor layer and address how to increase the VOC for zinc octaethylporphyrin [Zn(OEP]/C60 hetero-junction OPV cells [ITO/Zn(OEP/C60/Al]. It was found that crystallization of Zn(OEP films increases the number of inter-molecular charge transfer (IMCT excitons and enlarges the mobility of carriers and IMCT excitons, thus significantly improving the external quantum efficiency (EQE under illumination of the photoabsorption band due to the IMCT excitons. Conversely, charge accumulation of photo-generated carriers in the vicinity of the donor/acceptor (D/A interface was found to play a key role in determining the VOC for the OPV cells.

  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. Improved antibody production in Chinese hamster ovary cells by ATF4 overexpression

    OpenAIRE

    Haredy, AM; Nishizawa, A.; Honda, K.; T. Ohya; Ohtake, H; Omasa, T

    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...

  15. Behavior of parasite-specific effector CD8+ T cells in the brain and visualization of a kinesis-associated system of reticular fibers.

    Science.gov (United States)

    Wilson, Emma H; Harris, Tajie H; Mrass, Paulus; John, Beena; Tait, Elia D; Wu, Gregory F; Pepper, Marion; Wherry, E John; Dzierzinski, Florence; Roos, David; Haydon, Philip G; Laufer, Terri M; Weninger, Wolfgang; Hunter, Christopher A

    2009-02-20

    To understand lymphocyte behavior in the brain, we used two-photon microscopy to visualize effector CD8(+) T cells during toxoplasmic encephalitis. These cells displayed multiple behaviors with two distinct populations of cells apparent: one with a constrained pattern of migration and one with a highly migratory subset. The proportion of these populations varied over time associated with changes in antigen availability as well as T cell expression of the inhibitory receptor PD1. Unexpectedly, the movement of infiltrating cells was closely associated with an infection-induced reticular system of fibers. This observation suggests that, whereas in other tissues pre-existing scaffolds exist that guide lymphocyte migration, in the brain specialized structures are induced by inflammation that guide migration of T cells in this immune-privileged environment.

  16. 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.

  17. Visual Servoing

    OpenAIRE

    Chaumette, Francois; Hutchinson, Seth; Corke, Peter

    2016-01-01

    International audience; This chapter introduces visual servo control, using computer vision data in the servo loop to control the motion of a robot. We first describe the basic techniques that are by now well established in the field. We give a general overview of the formulation of the visual servo control problem, and describe the two archetypal visual servo control schemes: image-based and pose-based visual servo control. We then discuss performance and stability issues that pertain to the...

  18. Improved quality of optical coherence tomography imaging of basal cell carcinomas using speckle reduction

    DEFF Research Database (Denmark)

    Mogensen, Mette; Jørgensen, Thomas Martini; Thrane, Lars;

    2010-01-01

    suggests a method for improving OCT image quality for skin cancer imaging. EXPERIMENTAL DESIGN: OCT is an optical imaging method analogous to ultrasound. Two basal cell carcinomas (BCC) were imaged using an OCT speckle reduction technique (SR-OCT) based on repeated scanning by altering the distance between...... the probe and the surface of the skin. RESULTS: SR-OCT resulted in improved visualisation and more accurate thickness measurements in BCC lesions. CONCLUSION: This OCT speckle reduction method led to improved visualisation and better defined delineations in two BCC lesions. Thus, OCT was improved...... to a clinically relevant level when imaging BCC lesions....