WorldWideScience

Sample records for active optical sorting

  1. Microfluidic devices for analysis and active optical sorting of individual cells

    Czech Academy of Sciences Publication Activity Database

    Ježek, Jan; Pilát, Zdeněk; Šerý, Mojmír; Kaňka, Jan; Samek, Ota; Bernatová, Silvie; Zemánek, Pavel

    2013-01-01

    Roč. 58, č. 2 (2013), s. 55-59 ISSN 0447-6441 R&D Projects: GA MPO FR-TI1/433; GA MŠk ED0017/01/01; GA ČR GAP205/11/1687 Institutional support: RVO:68081731 Keywords : microfluidic * cell sorting * optical tweezers * Raman spectroscopy Subject RIV: EI - Biotechnology ; Bionics

  2. System for optical sorting of microscopic objects

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to a system for optical sorting of microscopic objects and corresponding method. An optical detection system (52) is capable of determining the positions of said first and/or said second objects. One or more force transfer units (200, 205, 210, 215) are placed...... in a first reservoir, the one or more force units being suitable for optical momentum transfer. An electromagnetic radiation source (42) yields a radiation beam (31, 32) capable of optically displacing the force transfer units from one position to another within the first reservoir (1R). The force transfer...... units are displaced from positions away from the first objects to positions close to the first objects, and then displacing the first objects via a contact force (300) between the first objects and the force transfer units facilitates an optical sorting of the first objects and the second objects....

  3. Optical cell sorting with multiple imaging modalities

    DEFF Research Database (Denmark)

    Banas, Andrew; Carrissemoux, Caro; Palima, Darwin

    2017-01-01

    healthy cells. With the richness of visual information, a lot of microscopy techniques have been developed and have been crucial in biological studies. To utilize their complementary advantages we adopt both fluorescence and brightfield imaging in our optical cell sorter. Brightfield imaging has...... the advantage of being non-invasive, thus maintaining cell viability. Fluorescence imaging, on the other hand, takes advantages of the chemical specificity of fluorescence markers and can validate machine vision results from brightfield images. Visually identified cells are sorted using optical manipulation...

  4. Integration through a Card-Sort Activity

    Science.gov (United States)

    Green, Kris; Ricca, Bernard P.

    2015-01-01

    Learning to compute integrals via the various techniques of integration (e.g., integration by parts, partial fractions, etc.) is difficult for many students. Here, we look at how students in a college level Calculus II course develop the ability to categorize integrals and the difficulties they encounter using a card sort-resort activity. Analysis…

  5. A Sort-Last Rendering System over an Optical Backplane

    Directory of Open Access Journals (Sweden)

    Yasuhiro Kirihata

    2005-06-01

    Full Text Available Sort-Last is a computer graphics technique for rendering extremely large data sets on clusters of computers. Sort-Last works by dividing the data set into even-sized chunks for parallel rendering and then composing the images to form the final result. Since sort-last rendering requires the movement of large amounts of image data among cluster nodes, the network interconnecting the nodes becomes a major bottleneck. In this paper, we describe a sort-last rendering system implemented on a cluster of computers whose nodes are connected by an all-optical switch. The rendering system introduces the notion of the Photonic Computing Engine, a computing system built dynamically by using the optical switch to create dedicated network connections among cluster nodes. The sort-last volume rendering algorithm was implemented on the Photonic Computing Engine, and its performance is evaluated. Prelimi- nary experiments show that performance is affected by the image composition time and average payload size. In an attempt to stabilize the performance of the system, we have designed a flow control mechanism that uses feedback messages to dynamically adjust the data flow rate within the computing engine.

  6. A monolithic glass chip for active single-cell sorting based on mechanical phenotyping.

    Science.gov (United States)

    Faigle, Christoph; Lautenschläger, Franziska; Whyte, Graeme; Homewood, Philip; Martín-Badosa, Estela; Guck, Jochen

    2015-03-07

    The mechanical properties of biological cells have long been considered as inherent markers of biological function and disease. However, the screening and active sorting of heterogeneous populations based on serial single-cell mechanical measurements has not been demonstrated. Here we present a novel monolithic glass chip for combined fluorescence detection and mechanical phenotyping using an optical stretcher. A new design and manufacturing process, involving the bonding of two asymmetrically etched glass plates, combines exact optical fiber alignment, low laser damage threshold and high imaging quality with the possibility of several microfluidic inlet and outlet channels. We show the utility of such a custom-built optical stretcher glass chip by measuring and sorting single cells in a heterogeneous population based on their different mechanical properties and verify sorting accuracy by simultaneous fluorescence detection. This offers new possibilities of exact characterization and sorting of small populations based on rheological properties for biological and biomedical applications.

  7. System of radwaste sorting out physical features and activities

    International Nuclear Information System (INIS)

    Batij, V.G.; Kuz'menko, V.A.; Bozhko, V.P.; Ganenko, V.B.; Olejnik, S.N.

    2000-01-01

    Classification of radioactive waste sources in Ukraine is provided. General technological sorting scheme of the RAW of chiefly. Chernobyl origin is offered. Some measures to treat short-lived and long-lived High-Level Waste, Intermediate-Active Waste and Low-Level Active Waste in the Center for waste treatment and disposal are offered. 4 refs., 2 tab., 8 figs

  8. Light at work: The use of optical forces for particle manipulation, sorting, and analysis

    Czech Academy of Sciences Publication Activity Database

    Jonáš, Alexandr; Zemánek, Pavel

    2008-01-01

    Roč. 29, č. 24 (2008), s. 4813-4851 ISSN 0173-0835 R&D Projects: GA MŠk(CZ) LC06007; GA MŠk OC08034 Institutional research plan: CEZ:AV0Z20650511 Keywords : microfluidics * optical chromatography and sorting * optical force and torque * optical tweezers and micro-manipulation / Optical tweezers and micro-manipulation / Raman microspectroscopy * Raman microspectroscopy Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.509, year: 2008

  9. Coupling Bacterial Activity Measurements with Cell Sorting by Flow Cytometry.

    Science.gov (United States)

    Servais; Courties; Lebaron; Troussellier

    1999-08-01

    > Abstract A new procedure to investigate the relationship between bacterial cell size and activity at the cellular level has been developed; it is based on the coupling of radioactive labeling of bacterial cells and cell sorting by flow cytometry after SYTO 13 staining. Before sorting, bacterial cells were incubated in the presence of tritiated leucine using a procedure similar to that used for measuring bacterial production by leucine incorporation and then stained with SYTO 13. Subpopulations of bacterial cells were sorted according to their average right-angle light scatter (RALS) and fluorescence. Average RALS was shown to be significantly related to the average biovolume. Experiments were performed on samples collected at different times in a Mediterranean seawater mesocosm enriched with nitrogen and phosphorus. At four sampling times, bacteria were sorted in two subpopulations (cells smaller and larger than 0.25 µm(3)). The results indicate that, at each sampling time, the growth rate of larger cells was higher than that of smaller cells. In order to confirm this tendency, cell sorting was performed on six subpopulations differing in average biovolume during the mesocosm follow-up. A clear increase of the bacterial growth rates was observed with increasing cell size for the conditions met in this enriched mesocosm.http://link.springer-ny.com/link/service/journals/00248/bibs/38n2p180.html

  10. Optical sorting and photo-transfection of mammalian cells

    CSIR Research Space (South Africa)

    Mthunzi, P

    2010-02-01

    Full Text Available and that the scattering force can enable sorting through axial guiding onto laminin coated glass coverslips upon which the selected cells adhere. Following this, I report on transient photo-transfection of mammalian cells including neuroblastomas (rat/mouse and human...

  11. Dielectrophoretic focusing integrated pulsed laser activated cell sorting

    Science.gov (United States)

    Zhu, Xiongfeng; Kung, Yu-Chun; Wu, Ting-Hsiang; Teitell, Michael A.; Chiou, Pei-Yu

    2017-08-01

    We present a pulsed laser activated cell sorter (PLACS) integrated with novel sheathless size-independent dielectrophoretic (DEP) focusing. Microfluidic fluorescence activated cell sorting (μFACS) systems aim to provide a fully enclosed environment for sterile cell sorting and integration with upstream and downstream microfluidic modules. Among them, PLACS has shown a great potential in achieving comparable performance to commercial aerosol-based FACS (>90% purity at 25,000 cells sec-1). However conventional sheath flow focusing method suffers a severe sample dilution issue. Here we demonstrate a novel dielectrophoresis-integrated pulsed laser activated cell sorter (DEP-PLACS). It consists of a microfluidic channel with 3D electrodes laid out to provide a tunnel-shaped electric field profile along a 4cmlong channel for sheathlessly focusing microparticles/cells into a single stream in high-speed microfluidic flows. All focused particles pass through the fluorescence detection zone along the same streamline regardless of their sizes and types. Upon detection of target fluorescent particles, a nanosecond laser pulse is triggered and focused in a neighboring channel to generate a rapidly expanding cavitation bubble for precise sorting. DEP-PLACS has achieved a sorting purity of 91% for polystyrene beads at a throughput of 1,500 particle/sec.

  12. CellSort: a support vector machine tool for optimizing fluorescence-activated cell sorting and reducing experimental effort.

    Science.gov (United States)

    Yu, Jessica S; Pertusi, Dante A; Adeniran, Adebola V; Tyo, Keith E J

    2017-03-15

    High throughput screening by fluorescence activated cell sorting (FACS) is a common task in protein engineering and directed evolution. It can also be a rate-limiting step if high false positive or negative rates necessitate multiple rounds of enrichment. Current FACS software requires the user to define sorting gates by intuition and is practically limited to two dimensions. In cases when multiple rounds of enrichment are required, the software cannot forecast the enrichment effort required. We have developed CellSort, a support vector machine (SVM) algorithm that identifies optimal sorting gates based on machine learning using positive and negative control populations. CellSort can take advantage of more than two dimensions to enhance the ability to distinguish between populations. We also present a Bayesian approach to predict the number of sorting rounds required to enrich a population from a given library size. This Bayesian approach allowed us to determine strategies for biasing the sorting gates in order to reduce the required number of enrichment rounds. This algorithm should be generally useful for improve sorting outcomes and reducing effort when using FACS. Source code available at http://tyolab.northwestern.edu/tools/ . k-tyo@northwestern.edu. Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  13. Buoyancy-activated cell sorting using targeted biotinylated albumin microbubbles.

    Directory of Open Access Journals (Sweden)

    Yu-Ren Liou

    Full Text Available Cell analysis often requires the isolation of certain cell types. Various isolation methods have been applied to cell sorting, including fluorescence-activated cell sorting and magnetic-activated cell sorting. However, these conventional approaches involve exerting mechanical forces on the cells, thus risking cell damage. In this study we applied a novel isolation method called buoyancy-activated cell sorting, which involves using biotinylated albumin microbubbles (biotin-MBs conjugated with antibodies (i.e., targeted biotin-MBs. Albumin MBs are widely used as contrast agents in ultrasound imaging due to their good biocompatibility and stability. For conjugating antibodies, biotin is conjugated onto the albumin MB shell via covalent bonds and the biotinylated antibodies are conjugated using an avidin-biotin system. The albumin microbubbles had a mean diameter of 2 μm with a polydispersity index of 0.16. For cell separation, the MDA-MB-231 cells are incubated with the targeted biotin-MBs conjugated with anti-CD44 for 10 min, centrifuged at 10 g for 1 min, and then allowed 1 hour at 4 °C for separation. The results indicate that targeted biotin-MBs conjugated with anti-CD44 antibodies can be used to separate MDA-MB-231 breast cancer cells; more than 90% of the cells were collected in the MB layer when the ratio of the MBs to cells was higher than 70:1. Furthermore, we found that the separating efficiency was higher for targeted biotin-MBs than for targeted avidin-incorporated albumin MBs (avidin-MBs, which is the most common way to make targeted albumin MBs. We also demonstrated that the recovery rate of targeted biotin-MBs was up to 88% and the sorting purity was higher than 84% for a a heterogenous cell population containing MDA-MB-231 cells (CD44(+ and MDA-MB-453 cells (CD44-, which are classified as basal-like breast cancer cells and luminal breast cancer cells, respectively. Knowing that the CD44(+ is a commonly used cancer

  14. Axon-Axon Interactions Regulate Topographic Optic Tract Sorting via CYFIP2-Dependent WAVE Complex Function.

    Science.gov (United States)

    Cioni, Jean-Michel; Wong, Hovy Ho-Wai; Bressan, Dario; Kodama, Lay; Harris, William A; Holt, Christine E

    2018-03-07

    The axons of retinal ganglion cells (RGCs) are topographically sorted before they arrive at the optic tectum. This pre-target sorting, typical of axon tracts throughout the brain, is poorly understood. Here, we show that cytoplasmic FMR1-interacting proteins (CYFIPs) fulfill non-redundant functions in RGCs, with CYFIP1 mediating axon growth and CYFIP2 specifically involved in axon sorting. We find that CYFIP2 mediates homotypic and heterotypic contact-triggered fasciculation and repulsion responses between dorsal and ventral axons. CYFIP2 associates with transporting ribonucleoprotein particles in axons and regulates translation. Axon-axon contact stimulates CYFIP2 to move into growth cones where it joins the actin nucleating WAVE regulatory complex (WRC) in the periphery and regulates actin remodeling and filopodial dynamics. CYFIP2's function in axon sorting is mediated by its binding to the WRC but not its translational regulation. Together, these findings uncover CYFIP2 as a key regulatory link between axon-axon interactions, filopodial dynamics, and optic tract sorting. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Spiral Transformation for High-Resolution and Efficient Sorting of Optical Vortex Modes

    Science.gov (United States)

    Wen, Yuanhui; Chremmos, Ioannis; Chen, Yujie; Zhu, Jiangbo; Zhang, Yanfeng; Yu, Siyuan

    2018-05-01

    Mode sorting is an essential function for optical multiplexing systems that exploit the orthogonality of the orbital angular momentum mode space. The familiar log-polar optical transformation provides a simple yet efficient approach whose resolution is, however, restricted by a considerable overlap between adjacent modes resulting from the limited excursion of the phase along a complete circle around the optical vortex axis. We propose and experimentally verify a new optical transformation that maps spirals (instead of concentric circles) to parallel lines. As the phase excursion along a spiral in the wave front of an optical vortex is theoretically unlimited, this new optical transformation can separate orbital angular momentum modes with superior resolution while maintaining unity efficiency.

  16. Spanish translation and validation of the Preschool Activity Card Sort.

    Science.gov (United States)

    Stoffel, Ashley; Berg, Christine

    2008-05-01

    Few standardized assessments exist for children living in the United States who are Hispanic/Latino. This study reports the Spanish translation process for the Preschool Activity Card Sort (PACS), which is a measure of participation in preschool children, and examines content, construct, and concurrent validity. Methods of verifying accuracy of translation included expert review and back translation and supported content validity of the Tarjetas de Actividades Preescolares (TAP). Subsequently, a sample of 37 parents of children between 3 and 6 years of age completed the PACS/TAP by structured interview. Twenty-six parents were Spanish speaking, and 11 were English speaking. A comparison of reported participation by Spanish- and English-speaking children provides initial construct validity of the TAP. Results indicate that the TAP differentiates among children of recent immigrants as compared to preschoolers who were born in the United States on domains of self-care, high and low demand leisure, and educational activities. Results emphasize the importance of considering sociocultural influences when assessing participation. PACS/TAP scores were moderately correlated with Pediatric Evaluation of Disability Inventory scores for the self-care domain, but did not correlate with the mobility or social function domains. The PACS/TAP appears to provide a useful means of understanding preschoolers' participation. Future research is needed to further establish the validity of this assessment.

  17. Binar Sort: A Linear Generalized Sorting Algorithm

    OpenAIRE

    Gilreath, William F.

    2008-01-01

    Sorting is a common and ubiquitous activity for computers. It is not surprising that there exist a plethora of sorting algorithms. For all the sorting algorithms, it is an accepted performance limit that sorting algorithms are linearithmic or O(N lg N). The linearithmic lower bound in performance stems from the fact that the sorting algorithms use the ordering property of the data. The sorting algorithm uses comparison by the ordering property to arrange the data elements from an initial perm...

  18. Noninvasive prenatal diagnosis. Use of density gradient centrifugation, magnetically activated cell sorting and in situ hybridization

    DEFF Research Database (Denmark)

    Campagnoli, C; Multhaupt, H A; Ludomirski, A

    1997-01-01

    OBJECTIVE: To develop a noninvasive method suitable for clinical prenatal diagnosis. STUDY DESIGN: Fetal nucleated erythrocytes were separated from peripheral blood of 17 healthy pregnant women using small magnetically activated cell sorting columns (MiniMACS) following density gradient centrifug...

  19. Optical force on diseased blood cells: Towards the optical sorting of biological matter

    KAUST Repository

    Gongora, J. S. Totero; Fratalocchi, Andrea

    2015-01-01

    By employing a series of massively parallel ab-initio simulations, we study how optical forces act on biological matter subject to morphological disease. As a representative case study, we here consider the case of Plasmodium falciparum on red blood

  20. Optical force on diseased blood cells: Towards the optical sorting of biological matter

    KAUST Repository

    Gongora, J. S. Totero

    2015-05-01

    By employing a series of massively parallel ab-initio simulations, we study how optical forces act on biological matter subject to morphological disease. As a representative case study, we here consider the case of Plasmodium falciparum on red blood cells (RBC) illuminated by a monochromatic plane wave. Realistic parameters for the geometry and the refractive index are then taken from published experiments. In our theoretical campaign, we study the dependence of the optical force on the disease stage for different incident wavelengths. We show that optical forces change significantly with the disease, with amplitude variation in the hundreds of pN range. Our results open up new avenues for the design of new optical systems for the treatment of human disease. © 2015 Elsevier Ltd.

  1. Sorting catalytically active polymersome nanoreactors by flow cytometry

    NARCIS (Netherlands)

    Nallani, M.; Woestenenk, R.; de Hoog, H.P.M.; van Dongen, S.F.M.; Boezeman, J.; Cornelissen, J.J.L.M.; Nolte, R.J.M.; van Hest, J.C.M.

    2009-01-01

    A strategy that involves a versatile one-step preparation procedure of enzyme filled porous and stable polymeric catalytically active nanoreactors (polymersomes) by flow cytometry was reported. A 1:1 mixture of the polymerase dispersions was analyzed in a Coulter Epics Elite Flow Cytometer, while

  2. Below Regulatory Concern Owners Group: An evaluation of dry active waste sorting: Final report

    International Nuclear Information System (INIS)

    Casey, S.M.

    1989-02-01

    The objective of this research was to determine the accuracy of manual inspection of Dry Active Waste (DAW). Three studies were conducted at two nuclear power plants in which unmodified DAW waste streams of roughly 10,000 items each were inspected by technicians using pancake probes. Sorting performance was measured unobtrusively by intercepting the ''outflow'' from inspection stations. Verification of sorting accuracy was performed with a prototype, semi-automated sorting table employing a matrix of fixed plastic scintillation detectors. More than 30,000 items of trash were examined, classified, counted, and verified, and the composition of the ''inflow'' to the inspection stations was determined by reconstructing the ''outflow'' components, as determined during verification procedures. The results showed that between 1 and 19% of all items in each of the three DAW waste streams were contaminated at levels ≥100 ccpm. Sixty-two percent of the ''contaminated'' items in Study I, 87% of the contaminated items in Study II, and 97% of the contaminated items in Study III were detected. One-half to one percent of all items classified as <100 ccpm by technicians were actually ≥100 ccpm. False positive rates were very high in all three studies. The production rates and accuracy obtained on the semi-automated plastic scintillation sorting table used during the verification stages of this project greatly exceeded the rates for manual sorting. 9 figs., 13 tabs

  3. Pulsed laser activated cell sorter (PLACS) for high-throughput fluorescent mammalian cell sorting

    Science.gov (United States)

    Chen, Yue; Wu, Ting-Hsiang; Chung, Aram; Kung, Yu-Chung; Teitell, Michael A.; Di Carlo, Dino; Chiou, Pei-Yu

    2014-09-01

    We present a Pulsed Laser Activated Cell Sorter (PLACS) realized by exciting laser induced cavitation bubbles in a PDMS microfluidic channel to create high speed liquid jets to deflect detected fluorescent samples for high speed sorting. Pulse laser triggered cavitation bubbles can expand in few microseconds and provide a pressure higher than tens of MPa for fluid perturbation near the focused spot. This ultrafast switching mechanism has a complete on-off cycle less than 20 μsec. Two approaches have been utilized to achieve 3D sample focusing in PLACS. One is relying on multilayer PDMS channels to provide 3D hydrodynamic sheath flows. It offers accurate timing control of fast (2 m sec-1) passing particles so that synchronization with laser bubble excitation is possible, an critically important factor for high purity and high throughput sorting. PLACS with 3D hydrodynamic focusing is capable of sorting at 11,000 cells/sec with >95% purity, and 45,000 cells/sec with 45% purity using a single channel in a single step. We have also demonstrated 3D focusing using inertial flows in PLACS. This sheathless focusing approach requires 10 times lower initial cell concentration than that in sheath-based focusing and avoids severe sample dilution from high volume sheath flows. Inertia PLACS is capable of sorting at 10,000 particles sec-1 with >90% sort purity.

  4. The Dutch Activity Card Sort institutional version was reproducible, but biased against women

    NARCIS (Netherlands)

    Jong, A. M.; van Nes, F. A.; Lindeboom, R.

    2012-01-01

    Purpose: To examine the reproducibility of the institutional version of the Dutch Activity Card Sort (ACS-NL) and the possible presence of gender bias. Methods: Older rehabilitation inpatients (N = 52) were included. Intra-and inter-rater agreement for the ACS-NL total and subscale scores was

  5. The Dutch Activity Card Sort institutional version was reproducible, but biased against women

    NARCIS (Netherlands)

    Jong, A. M.; van Nes, F. A.; Lindeboom, R.

    2012-01-01

    PURPOSE: To examine the reproducibility of the institutional version of the Dutch Activity Card Sort (ACS-NL) and the possible presence of gender bias. METHODS: Older rehabilitation inpatients (N = 52) were included. Intra- and inter-rater agreement for the ACS-NL total and subscale scores was

  6. Sorting Out Sorts

    OpenAIRE

    Jonathan B. Berk

    1998-01-01

    In this paper we analyze the theoretical implications of sorting data into groups and then running asset pricing tests within each group. We show that the way this procedure is implemented introduces a severe bias in favor of rejecting the model under consideration. By simply picking enough groups to sort into even the true asset pricing model can be shown to have no explanatory power within each group.

  7. Volume reduction of dry active waste by use of a waste sorting table at the Brunswick nuclear power plant

    International Nuclear Information System (INIS)

    Snead, P.B.

    1988-01-01

    Carolina Power and Light Company's Brunswick nuclear power plant has been using a National Nuclear Corporation Model WST-18 Waste Sorting Table to monitor and sort dry active waste for segregating uncontaminated material as a means of low-level waste volume reduction. The WST-18 features 18 large-area, solid scintillation detectors arranged in a 3 x 6 array underneath a sorting/monitoring surface that is shielded from background radiation. An 11-week study at Brunswick showed that the use of the waste sorting table resulted in dramatic improvements in both productivity (man-hours expended per cubic foot of waste processed) and monitoring quality over the previous hand-probe frisking method. Use of the sorting table since the study has confirmed its effectiveness in volume reduction. The waste sorting table paid for its operation in volume reduction savings alone, without accounting for the additional savings from recovering reusable items

  8. The development and implementation of a dry active waste (DAW) sorting program at Catawba Nuclear Station

    International Nuclear Information System (INIS)

    Schulte, J.H.; McNamara, P.N.

    1988-01-01

    Duke Power Company, like other nuclear utilities, bears a burdensome radwaste disposal cost that has rapidly escalated during recent years. Dry active waste (DAW) represents approximately 85% of the total radioactive waste volume shipped to low-level disposal facilities. Sorting waste with less than detectable radioactivity from waste with detectable radioactivity provides a volume reduction (VR) technique that can save significant radwaste disposal costs and conserve dwindling burial space. This paper presents the development and results of a project that was conducted at Catawba Nuclear Station to determine the volume reduction potential from sorting DAW. Guidelines are given so that other utilities can perform a VR potential study on a low cost basis. Based on the results of the DAW VR study, an overall DAW volume radiation program was initiated at Duke Power Company. This program includes personnel training, drumming techniques, bag tracking and equipment purchases for sorting. This program has been fully implemented at Duke Power Company since January 1, 1988 and preliminary results and savings are given

  9. Experimental demonstration of optical transport, sorting and self-arrangement using a “tractor beam"

    Czech Academy of Sciences Publication Activity Database

    Brzobohatý, Oto; Karásek, Vítězslav; Šiler, Martin; Chvátal, Lukáš; Čižmár, T.; Zemánek, Pavel

    2013-01-01

    Roč. 7, č. 2 (2013), s. 123-127 ISSN 1749-4885 R&D Projects: GA ČR GA202/09/0348; GA ČR GPP205/11/P294; GA MŠk LH12018; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : theoretical determination * radiation force * tweezers * binding Subject RIV: BH - Optics, Masers, Lasers Impact factor: 29.958, year: 2013

  10. Optical sorting of nonspherical and living microobjects in moving interference structures

    Czech Academy of Sciences Publication Activity Database

    Jákl, Petr; Arzola, A. V.; Šiler, Martin; Chvátal, Lukáš; Volke-Sepulveda, K.; Zemánek, Pavel

    2014-01-01

    Roč. 22, č. 24 (2014), s. 29746-29760 ISSN 1094-4087 R&D Projects: GA MŠk(CZ) LD14069; GA MŠk LH12018; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : standing-wave * forces * microparticles * tweezers * chromatography Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.488, year: 2014

  11. Purification of human induced pluripotent stem cell-derived neural precursors using magnetic activated cell sorting.

    Science.gov (United States)

    Rodrigues, Gonçalo M C; Fernandes, Tiago G; Rodrigues, Carlos A V; Cabral, Joaquim M S; Diogo, Maria Margarida

    2015-01-01

    Neural precursor (NP) cells derived from human induced pluripotent stem cells (hiPSCs), and their neuronal progeny, will play an important role in disease modeling, drug screening tests, central nervous system development studies, and may even become valuable for regenerative medicine treatments. Nonetheless, it is challenging to obtain homogeneous and synchronously differentiated NP populations from hiPSCs, and after neural commitment many pluripotent stem cells remain in the differentiated cultures. Here, we describe an efficient and simple protocol to differentiate hiPSC-derived NPs in 12 days, and we include a final purification stage where Tra-1-60+ pluripotent stem cells (PSCs) are removed using magnetic activated cell sorting (MACS), leaving the NP population nearly free of PSCs.

  12. Lipid phosphate phosphatase activity regulates dispersal and bilateral sorting of embryonic germ cells in Drosophila

    Science.gov (United States)

    Renault, Andrew D.; Kunwar, Prabhat S.; Lehmann, Ruth

    2010-01-01

    In Drosophila, germ cell survival and directionality of migration are controlled by two lipid phosphate phosphatases (LPP), wunen (wun) and wunen-2 (wun2). wun wun2 double mutant analysis reveals that the two genes, hereafter collectively called wunens, act redundantly in primordial germ cells. We find that wunens mediate germ cell-germ cell repulsion and that this repulsion is necessary for germ cell dispersal and proper transepithelial migration at the onset of migration and for the equal sorting of the germ cells between the two embryonic gonads during their migration. We propose that this dispersal function optimizes adult fecundity by assuring maximal germ cell occupancy of both gonads. Furthermore, we find that the requirement for wunens in germ cell survival can be eliminated by blocking germ cell migration. We suggest that this essential function of Wunen is needed to maintain cell integrity in actively migrating germ cells. PMID:20431117

  13. Reprocessing-recycling, or the application of the selective sorting and recycling policy to nuclear activities

    International Nuclear Information System (INIS)

    1998-12-01

    In France, the reprocessing of spent fuels is the solution that has been retained for the management of the end-of-cycle. The sorting of the different components of spent fuels allows the recycling of uranium and plutonium for the further production of enriched uranium and mixed oxide fuels. This paper presents Cogema's advances in this domain (facilities and plants), the transfer of Cogema's reprocessing and recycling technologies in other countries (Japan, USA, Russia), the economical and environmental advantages of the recycling of spent fuels, the economical resources provided by this activity, and the cooperation with foreign countries for the reprocessing of their spent fuels at Cogema-La Hague. (J.S.)

  14. A time-sorting pitfall trap and temperature datalogger for the sampling of surface-active arthropods

    OpenAIRE

    McMunn, Marshall S.

    2017-01-01

    Nearly all arthropods display consistent patterns of activity according to time of day. These patterns of activity often limit the extent of animal co-occurrence in space and time. Quantifying when particular species are active and how activity varies with environmental conditions is difficult without the use of automated devices due to the need for continuous monitoring. Time-sorting pitfall traps passively collect active arthropods into containers with known beginning and end sample times. ...

  15. Raman-Activated Droplet Sorting (RADS) for Label-Free High-Throughput Screening of Microalgal Single-Cells.

    Science.gov (United States)

    Wang, Xixian; Ren, Lihui; Su, Yetian; Ji, Yuetong; Liu, Yaoping; Li, Chunyu; Li, Xunrong; Zhang, Yi; Wang, Wei; Hu, Qiang; Han, Danxiang; Xu, Jian; Ma, Bo

    2017-11-21

    Raman-activated cell sorting (RACS) has attracted increasing interest, yet throughput remains one major factor limiting its broader application. Here we present an integrated Raman-activated droplet sorting (RADS) microfluidic system for functional screening of live cells in a label-free and high-throughput manner, by employing AXT-synthetic industrial microalga Haematococcus pluvialis (H. pluvialis) as a model. Raman microspectroscopy analysis of individual cells is carried out prior to their microdroplet encapsulation, which is then directly coupled to DEP-based droplet sorting. To validate the system, H. pluvialis cells containing different levels of AXT were mixed and underwent RADS. Those AXT-hyperproducing cells were sorted with an accuracy of 98.3%, an enrichment ratio of eight folds, and a throughput of ∼260 cells/min. Of the RADS-sorted cells, 92.7% remained alive and able to proliferate, which is equivalent to the unsorted cells. Thus, the RADS achieves a much higher throughput than existing RACS systems, preserves the vitality of cells, and facilitates seamless coupling with downstream manipulations such as single-cell sequencing and cultivation.

  16. Rapid isolation of antibody from a synthetic human antibody library by repeated fluorescence-activated cell sorting (FACS.

    Directory of Open Access Journals (Sweden)

    Sung Sun Yim

    Full Text Available Antibodies and their derivatives are the most important agents in therapeutics and diagnostics. Even after the significant progress in the technology for antibody screening from huge libraries, it takes a long time to isolate an antibody, which prevents a prompt action against the spread of a disease. Here, we report a new strategy for isolating desired antibodies from a combinatorial library in one day by repeated fluorescence-activated cell sorting (FACS. First, we constructed a library of synthetic human antibody in which single-chain variable fragment (scFv was expressed in the periplasm of Escherichia coli. After labeling the cells with fluorescent antigen probes, the highly fluorescent cells were sorted by using a high-speed cell sorter, and these cells were reused without regeneration in the next round of sorting. After repeating this sorting, the positive clones were completely enriched in several hours. Thus, we screened the library against three viral antigens, including the H1N1 influenza virus, Hepatitis B virus, and Foot-and-mouth disease virus. Finally, the potential antibody candidates, which show K(D values between 10 and 100 nM against the target antigens, could be successfully isolated even though the library was relatively small (∼ 10(6. These results show that repeated FACS screening without regeneration of the sorted cells can be a powerful method when a rapid response to a spreading disease is required.

  17. Tracking heavy water (D2O) incorporation for identifying and sorting active microbial cells

    DEFF Research Database (Denmark)

    Berry, David; Mader, Esther; Lee, Tae Kwon

    2015-01-01

    Microbial communities are essential to the function of virtually all ecosystems and eukaryotes, including humans. However, it is still a major challenge to identify microbial cells active under natural conditions in complex systems. In this study, we developed a new method to identify and sort ac...

  18. Natural killer (NK)-cell activity in sorted subsets of peripheral blood mononuclear cells from patients with severe combined immunodeficiency

    NARCIS (Netherlands)

    ten Berge, R. J.; Schellekens, P. T.; Budding-Koppenol, A.; Dooren, L. J.; Vossen, J. M.

    1987-01-01

    Natural killer-cell activity for K562 target cells was measured in 13 patients with severe combined immunodeficiency before bone marrow transplantation. Both unseparated peripheral blood mononuclear cells and sorted cell subsets (B73.1 positive, B73.1 negative, OKT3 positive, OKT3 negative) were

  19. Active Faraday optical frequency standard.

    Science.gov (United States)

    Zhuang, Wei; Chen, Jingbiao

    2014-11-01

    We propose the mechanism of an active Faraday optical clock, and experimentally demonstrate an active Faraday optical frequency standard based on narrow bandwidth Faraday atomic filter by the method of velocity-selective optical pumping of cesium vapor. The center frequency of the active Faraday optical frequency standard is determined by the cesium 6 (2)S(1/2) F=4 to 6 (2)P(3/2) F'=4 and 5 crossover transition line. The optical heterodyne beat between two similar independent setups shows that the frequency linewidth reaches 281(23) Hz, which is 1.9×10(4) times smaller than the natural linewidth of the cesium 852-nm transition line. The maximum emitted light power reaches 75 μW. The active Faraday optical frequency standard reported here has advantages of narrow linewidth and reduced cavity pulling, which can readily be extended to other atomic transition lines of alkali and alkaline-earth metal atoms trapped in optical lattices at magic wavelengths, making it useful for new generation of optical atomic clocks.

  20. A time-sorting pitfall trap and temperature datalogger for the sampling of surface-active arthropods

    Directory of Open Access Journals (Sweden)

    Marshall S. McMunn

    2017-04-01

    Full Text Available Nearly all arthropods display consistent patterns of activity according to time of day. These patterns of activity often limit the extent of animal co-occurrence in space and time. Quantifying when particular species are active and how activity varies with environmental conditions is difficult without the use of automated devices due to the need for continuous monitoring. Time-sorting pitfall traps passively collect active arthropods into containers with known beginning and end sample times. The trap described here, similar to previous designs, sorts arthropods by the time they fall into the trap using a rotating circular rack of vials. This trap represents a reduction in size, cost, and time of construction, while increasing the number of time windows sampled. The addition of temperature data collection extends functionality, while the use of store-bought components and inclusion of customizable software make the trap easy to reproduce and use.

  1. Ore sorting

    International Nuclear Information System (INIS)

    Hawkins, A.P.; Richards, A.W.

    1982-01-01

    In an ore sorting apparatus, ore particles are bombarded with neutrons in a chamber and sorted by detecting radiation emitted by isotopes of elements, such as gold, forming or contained in the particles, using detectors and selectively controlling fluid jets. The isotopes can be selectively recognised by their radiation characteristics. In an alternative embodiment, shorter life isotopes are formed by neutron bombardment and detection of radiation takes place immediately adjacent the region of bombardment

  2. Improved methods for reprogramming human dermal fibroblasts using fluorescence activated cell sorting.

    Directory of Open Access Journals (Sweden)

    David J Kahler

    Full Text Available Current methods to derive induced pluripotent stem cell (iPSC lines from human dermal fibroblasts by viral infection rely on expensive and lengthy protocols. One major factor contributing to the time required to derive lines is the ability of researchers to identify fully reprogrammed unique candidate clones from a mixed cell population containing transformed or partially reprogrammed cells and fibroblasts at an early time point post infection. Failure to select high quality colonies early in the derivation process results in cell lines that require increased maintenance and unreliable experimental outcomes. Here, we describe an improved method for the derivation of iPSC lines using fluorescence activated cell sorting (FACS to isolate single cells expressing the cell surface marker signature CD13(NEGSSEA4(POSTra-1-60(POS on day 7-10 after infection. This technique prospectively isolates fully reprogrammed iPSCs, and depletes both parental and "contaminating" partially reprogrammed fibroblasts, thereby substantially reducing the time and reagents required to generate iPSC lines without the use of defined small molecule cocktails. FACS derived iPSC lines express common markers of pluripotency, and possess spontaneous differentiation potential in vitro and in vivo. To demonstrate the suitability of FACS for high-throughput iPSC generation, we derived 228 individual iPSC lines using either integrating (retroviral or non- integrating (Sendai virus reprogramming vectors and performed extensive characterization on a subset of those lines. The iPSC lines used in this study were derived from 76 unique samples from a variety of tissue sources, including fresh or frozen fibroblasts generated from biopsies harvested from healthy or disease patients.

  3. Characterization of Rat Hair Follicle Stem Cells Selected by Vario Magnetic Activated Cell Sorting System

    International Nuclear Information System (INIS)

    Huang, Enyi; Lian, Xiaohua; Chen, Wei; Yang, Tian; Yang, Li

    2009-01-01

    Hair follicle stem cells (HfSCs) play crucial roles in hair follicle morphogenesis and hair cycling. These stem cells are self-renewable and have the multi-lineage potential to generate epidermis, sebaceous glands, and hair follicle. The separation and identification of hair follicle stem cells are important for further research in stem cell biology. In this study, we report on the successful enrichment of rat hair follicle stem cells through vario magnetic activated cell sorting (Vario MACS) and the biological characteristics of the stem cells. We chose the HfSCs positive surface markers CD34, α6-integrin and the negative marker CD71 to design four isolation strategies: positive selection with single marker of CD34, positive selection with single marker of α6-integrin, CD71 depletion followed by CD34 positive selection, and CD71 depletion followed by α6-integrin positive selection. The results of flow cytometry analysis showed that all four strategies had ideal effects. Specifically, we conducted a series of researches on HfSCs characterized by their high level of CD34, termed CD34 bri cells, and low to undetectable expression of CD34, termed CD34 dim cells. CD34 bri cells had greater proliferative potential and higher colony-forming ability than CD34 dim cells. Furthermore, CD34 bri cells had some typical characteristics as progenitor cells, such as large nucleus, obvious nucleolus, large nuclear:cytoplasmic ratio and few cytoplasmic organelles. Our findings clearly demonstrated that HfSCs with high purity and viability could be successfully enriched with Vario MACS

  4. Isolation of intact RNA from murine CD4+ T cells after intracellular cytokine staining and fluorescence-activated cell sorting.

    Science.gov (United States)

    Kunnath-Velayudhan, Shajo; Porcelli, Steven A

    2018-05-01

    Intracellular cytokine staining (ICS) is a powerful method for identifying functionally distinct lymphocyte subsets, and for isolating these by fluorescence activated cell sorting (FACS). Although transcriptomic analysis of cells sorted on the basis of ICS has many potential applications, this is rarely performed because of the difficulty in isolating intact RNA from cells processed using standard fixation and permeabilization buffers for ICS. To address this issue, we compared three buffers shown previously to preserve RNA in nonhematopoietic cells subjected to intracellular staining for their effects on RNA isolated from T lymphocytes processed for ICS. Our results showed that buffers containing the recombinant ribonuclease inhibitor RNasin or high molar concentrations of salt yielded intact RNA from fixed and permeabilized T cells. As proof of principle, we successfully used the buffer containing RNasin to isolate intact RNA from CD4 + T cells that were sorted by FACS on the basis of specific cytokine production, thus demonstrating the potential of this approach for coupling ICS with transcriptomic analysis. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Optically induced dielectropheresis sorting with automated medium exchange in an integrated optofluidic device resulting in higher cell viability.

    Science.gov (United States)

    Lee, Gwo-Bin; Wu, Huan-Chun; Yang, Po-Fu; Mai, John D

    2014-08-07

    We demonstrated the integration of a microfluidic device with an optically induced dielectrophoresis (ODEP) device such that the critical medium replacement process was performed automatically and the cells could be subsequently manipulated by using digitally projected optical images. ODEP has been demonstrated to generate sufficient forces for manipulating particles/cells by projecting a light pattern onto photoconductive materials which creates virtual electrodes. The production of the ODEP force usually requires a medium that has a suitable electrical conductivity and an appropriate dielectric constant. Therefore, a 0.2 M sucrose solution is commonly used. However, this requires a complicated medium replacement process before one is able to manipulate cells. Furthermore, the 0.2 M sucrose solution is not suitable for the long-term viability of cells. In comparison to conventional manual processes, our automated medium replacement process only took 25 minutes. Experimental data showed that there was up to a 96.2% recovery rate for the manipulated cells. More importantly, the survival rate of the cells was greatly enhanced due to this faster automated process. This newly developed microfluidic chip provided a promising platform for the rapid replacement of the cell medium and this was also the first time that an ODEP device was integrated with other active flow control components in a microfluidic device. By improving cell viability after cell manipulation, this design may contribute to the practical integration of ODEP modules into other lab-on-a-chip devices and biomedical applications in the future.

  6. Optical control of antibacterial activity

    Science.gov (United States)

    Velema, Willem A.; van der Berg, Jan Pieter; Hansen, Mickel J.; Szymanski, Wiktor; Driessen, Arnold J. M.; Feringa, Ben L.

    2013-11-01

    Bacterial resistance is a major problem in the modern world, stemming in part from the build-up of antibiotics in the environment. Novel molecular approaches that enable an externally triggered increase in antibiotic activity with high spatiotemporal resolution and auto-inactivation are highly desirable. Here we report a responsive, broad-spectrum, antibacterial agent that can be temporally activated with light, whereupon it auto-inactivates on the scale of hours. The use of such a ‘smart’ antibiotic might prevent the build-up of active antimicrobial material in the environment. Reversible optical control over active drug concentration enables us to obtain pharmacodynamic information. Precisely localized control of activity is achieved, allowing the growth of bacteria to be confined to defined patterns, which has potential for the development of treatments that avoid interference with the endogenous microbial population in other parts of the organism.

  7. Fluorescence-Activated Cell Sorting of EGFP-Labeled Neural Crest Cells From Murine Embryonic Craniofacial Tissue

    Directory of Open Access Journals (Sweden)

    Saurabh Singh

    2005-01-01

    Full Text Available During the early stages of embryogenesis, pluripotent neural crest cells (NCC are known to migrate from the neural folds to populate multiple target sites in the embryo where they differentiate into various derivatives, including cartilage, bone, connective tissue, melanocytes, glia, and neurons of the peripheral nervous system. The ability to obtain pure NCC populations is essential to enable molecular analyses of neural crest induction, migration, and/or differentiation. Crossing Wnt1-Cre and Z/EG transgenic mouse lines resulted in offspring in which the Wnt1-Cre transgene activated permanent EGFP expression only in NCC. The present report demonstrates a flow cytometric method to sort and isolate populations of EGFP-labeled NCC. The identity of the sorted neural crest cells was confirmed by assaying expression of known marker genes by TaqMan Quantitative Real-Time Polymerase Chain Reaction (QRT-PCR. The molecular strategy described in this report provides a means to extract intact RNA from a pure population of NCC thus enabling analysis of gene expression in a defined population of embryonic precursor cells critical to development.

  8. Apportioning bacterial carbon source utilization in soil using 14 C isotope analysis of FISH-targeted bacterial populations sorted by fluorescence activated cell sorting (FACS): 14 C-FISH-FACS.

    Science.gov (United States)

    Gougoulias, Christos; Meade, Andrew; Shaw, Liz J

    2018-02-19

    An unresolved need in microbial ecology is methodology to enable quantitative analysis of in situ microbial substrate carbon use at the population level. Here, we evaluated if a novel combination of radiocarbon-labelled substrate tracing, fluorescence in situ hybridisation (FISH) and fluorescence-activated cell sorting (FACS) to sort the FISH-targeted population for quantification of incorporated radioactivity ( 14 C-FISH-FACS) can address this need. Our test scenario used FISH probe PSE1284 targeting Pseudomonas spp. (and some Burkholderia spp.) and salicylic acid added to rhizosphere soil. We examined salicylic acid- 14 C fate (mineralized, cell-incorporated, extractable and non-extractable) and mass balance (0-24 h) and show that the PSE1284 population captured ∼ 50% of the Nycodenz extracted biomass 14 C. Analysis of the taxonomic distribution of the salicylic acid biodegradation trait suggested that PSE1284 population success was not due to conservation of this trait but due to competitiveness for the added carbon. Adding 50KBq of 14 C sample -1 enabled detection of 14 C in the sorted population at ∼ 60-600 times background; a sensitivity which demonstrates potential extension to analysis of rarer/less active populations. Given its sensitivity and compatibility with obtaining a C mass balance, 14 C-FISH-FACS allows quantitative dissection of C flow within the microbial biomass that has hitherto not been achieved. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

  9. Separation of active and inactive fractions from starved culture of Vibrio parahaemolyticus by density dependent cell sorting.

    Science.gov (United States)

    Nayak, Binaya Bhusan; Kamiya, Eriko; Nishino, Tomohiko; Wada, Minoru; Nishimura, Masahiko; Kogure, Kazuhiro

    2005-01-01

    The co-existence of physiologically different cells in bacterial cultures is a general phenomenon. We have examined the applicability of the density dependent cell sorting (DDCS) method to separate subpopulations from a long-term starvation culture of Vibrio parahaemolyticus. The cells were subjected to Percoll density gradient and separated into 12 fractions of different buoyant densities, followed by measuring the cell numbers, culturability, respiratory activity and leucine incorporation activity. While more than 78% of cells were in lighter fractions, about 95% of culturable cells were present in heavier fractions. The high-density subpopulations also had high proportion of cells capable of forming formazan granules. Although this was accompanied by the cell specific INT-reduction rate, both leucine incorporation rates and INT-reduction rates per cell had a peak at mid-density fraction. The present results indicated that DDCS could be used to separate subpopulations of different physiological conditions.

  10. Particle concentrating and sorting under a rotating electric field by direct optical-liquid heating in a microfluidics chip.

    Science.gov (United States)

    Chen, Yu-Liang; Jiang, Hong-Ren

    2017-05-01

    We demonstrate a functional rotating electrothermal technique for rapidly concentrating and sorting a large number of particles on a microchip by the combination of particle dielectrophoresis (DEP) and inward rotating electrothermal (RET) flows. Different kinds of particles can be attracted (positive DEP) to or repelled (negative DEP) from electrode edges, and then the n-DEP responsive particles are further concentrated in the heated region by RET flows. The RET flows arise from the spatial inhomogeneous electric properties of fluid caused by direct infrared laser (1470 nm) heating of solution in a rotating electric field. The direction of the RET flows is radially inward to the heated region with a co-field (the same as the rotating electric field) rotation. Moreover, the velocity of the RET flows is proportional to the laser power and the square of the electric field strength. The RET flows are significant over a frequency range from 200 kHz to 5 MHz. The RET flows are generated by the simultaneous application of the infrared laser and the rotating electric field. Therefore, the location of particle concentrating can be controlled within the rotating electric field depending on the position of the laser spot. This multi-field technique can be operated in salt solutions and at higher frequency without external flow pressure, and thus it can avoid electrokinetic phenomena at low frequency to improve the manipulation accuracy for lab-on-chip applications.

  11. Flow sorting in aquatic ecology

    Directory of Open Access Journals (Sweden)

    Marcus Reckermann

    2000-06-01

    Full Text Available Flow sorting can be a very helpful tool in revealing phytoplankton and bacterial community structure and elaborating specific physiological parameters of isolated species. Droplet sorting has been the most common technique. Despite the high optical and hydro-dynamic stress for the cells to be sorted, many species grow in culture subsequent to sorting. To date, flow sorting has been applied to post-incubation separation in natural water samples to account for group-specific physiological parameters (radiotracer-uptake rates, to the production of clonal or non-clonal cultures from mixtures, to the isolaton of cell groups from natural assemblages for molecular analyses, and for taxonomic identification of sorted cells by microscopy. The application of cell sorting from natural water samples from the Wadden Sea, including different cryptophytes, cyanobacteria and diatoms, is shown, as well as the establishment of laboratory cultures from field samples. The optional use of a red laser to account for phycocyanine-rich cells is also discussed.

  12. Activity of some nucleases of cotton sorts and species of various radiosensitivity

    International Nuclear Information System (INIS)

    Nazirov, N.N.; Arslanova, S.B.

    1979-01-01

    The activity of some nucleases under the effect of gamma rays was studied on cotton varieties and species differing in radiosensitivity. It was found that acid nuclease was more active in wild cotton forms as compared to the cultivated varieties, whereas with alkaline DNA-ase it was opposite. At the radiation dose of 30 kR the activity of alkaline DNA-ase activated in 26-chromosome wild cotton G. arboreum ssp. alfusifalium and 52-chromosome S.h.ssp.mexicanum, while the activity of acid DNA-ase somewhat decreased. Under irradiating AN-402 variety (produced from ssp. mexicanum by irradiation) the activity of alkaline DNA-ase increased noticeably when budding, whereas the activity of acid DNA-ase was at the level of control. The activity of the alkaline DNA-ase form normalized in the phase of blooming. In C-70-59 variety (G.arboreum) the activity of both DNA-ases increased after irradiation in the phase of blooming. The activity of acid DNA-ase and RNA-ase drastically activated in guza 183 (G. herbaceum) under gamma irradiation, whereas that of alkaline ones remained unchanged

  13. Verification of counting sort and radix sort

    NARCIS (Netherlands)

    C.P.T. de Gouw (Stijn); F.S. de Boer (Frank); J.C. Rot (Jurriaan)

    2016-01-01

    textabstractSorting is an important algorithmic task used in many applications. Two main aspects of sorting algorithms which have been studied extensively are complexity and correctness. [Foley and Hoare, 1971] published the first formal correctness proof of a sorting algorithm (Quicksort). While

  14. Sorting Nexin 2 (SNX2): a potential marker of active thyrocytes in normal and hyperfunctioning thyroid disorders.

    Science.gov (United States)

    Kanzawa, Maki; Hara, Shigeo; Semba, Shuho; Yokozaki, Hiroshi; Hirokawa, Mitsuyoshi; Itoh, Tomoo

    2014-04-01

    Sorting nexins (SNXs) are a large, diverse group of cytoplasmic and membrane-associated proteins that function in a variety of cellular processes, including endocytosis, protein trafficking, and the retrieval of transmembrane proteins. In this study, we demonstrated that SNX2 is expressed in columnar and active thyroid follicular cells but not in flattened inactive thyrocytes. Morphometric analysis revealed a significant correlation between SNX2 positivity and columnar cell morphology. Immunohistochemical staining of serial sections of the thyroid tissue indicated that SNX2 localization was similar to sortilin, a protein expressed by active thyrocytes. Expression of SNX2 in thyrocytes is particularly marked and extensive in most hyperstimulated thyroid disorders, including Graves disease (diffusely SNX2 positive in 73.3% patients) and functioning nodules (93.8% patients). SNX2 immunolocalization in hyperstimulated follicular epithelial cells was specific among the SNXs family members examined. These results support the utility of SNX2 as a novel marker of active thyrocytes and reflect the endosomal trafficking activity in these cells.

  15. Measurement of optical activity of honey bee

    Science.gov (United States)

    Ortiz-Gutiérrez, Mauricio; Olivares-Pérez, Arturo; Salgado-Verduzco, Marco Antonio; Ibarra-Torres, Juan Carlos

    2016-03-01

    Optical activity of some substances, such as chiral molecules, often exhibits circular birefringence. Circular birefringence causes rotation of the vibration plane of the plane polarized light as it passes through the substance. In this work we present optical characterization of honey as function of the optical activity when it is placed in a polariscope that consists of a light source and properly arranged polarizing elements.

  16. Word Sorts for General Music Classes

    Science.gov (United States)

    Cardany, Audrey Berger

    2015-01-01

    Word sorts are standard practice for aiding children in acquiring skills in English language arts. When included in the general music classroom, word sorts may aid students in acquiring a working knowledge of music vocabulary. The author shares a word sort activity drawn from vocabulary in John Lithgow's children's book "Never Play…

  17. A Card-Sorting Activity to Engage Students in the Academic Language of Biology.

    Science.gov (United States)

    Wallon, Robert C; Jasti, Chandana; Hug, Barbara

    2017-03-01

    The activity described in this article is designed to provide biology students with opportunities to engage in a range of academic language as they learn the discipline-specific meanings of the terms "drug," "poison," "toxicant," and "toxin." Although intended as part of an introductory lesson in a comprehensive unit for the high school level, this approach to teaching academic language can be adapted for use with older or younger students and can be modified to teach other terms.

  18. The ROCK inhibitor Y-27632 improves recovery of human embryonic stem cells after fluorescence-activated cell sorting with multiple cell surface markers.

    Directory of Open Access Journals (Sweden)

    Nil Emre

    Full Text Available BACKGROUND: Due to the inherent sensitivity of human embryonic stem cells (hESCs to manipulations, the recovery and survival of hESCs after fluorescence-activated cell sorting (FACS can be low. Additionally, a well characterized and robust methodology for performing FACS on hESCs using multiple-cell surface markers has not been described. The p160-Rho-associated coiled kinase (ROCK inhibitor, Y-27632, previously has been identified as enhancing survival of hESCs upon single-cell dissociation, as well as enhancing recovery from cryopreservation. Here we examined the application of Y-27632 to hESCs after FACS to improve survival in both feeder-dependent and feeder-independent growth conditions. METHODOLOGY/PRINCIPAL FINDINGS: HESCs were sorted using markers for SSEA-3, TRA-1-81, and SSEA-1. Cells were plated after sorting for 24 hours in either the presence or the absence of Y-27632. In both feeder-dependent and feeder-independent conditions, cell survival was greater when Y-27632 was applied to the hESCs after sort. Specifically, treatment of cells with Y-27632 improved post-sort recovery up to four fold. To determine the long-term effects of sorting with and without the application of Y-27632, hESCs were further analyzed. Specifically, hESCs sorted with and without the addition of Y-27632 retained normal morphology, expressed hESC-specific markers as measured by immunocytochemistry and flow cytometry, and maintained a stable karyotype. In addition, the hESCs could differentiate into three germ layers in vitro and in vivo in both feeder-dependent and feeder-independent growth conditions. CONCLUSIONS/SIGNIFICANCE: The application of Y-27632 to hESCs after cell sorting improves cell recovery with no observed effect on pluripotency, and enables the consistent recovery of hESCs by FACS using multiple surface markers. This improved methodology for cell sorting of hESCs will aid many applications such as removal of hESCs from secondary cell types

  19. Tunable 'optical activity' in electrorheological fluids

    International Nuclear Information System (INIS)

    Zhao, Q.; Zhao, X.P.

    2005-01-01

    The 'optical activity' of adjustable periodic structure material (SiO 2 and pentaerythrital electrorheological (ER) fluids) is firstly investigated using two kinds of setup. It is found that the rotation angles can be tuned by the external electric field and weight concentrations, and the sign of the rotation angle is negative, so, the used ER fluids are defined as the left-handed optically active substances under the application of electric field. The laser diffraction patterns are also observed in the ER fluids, which indicates the formation of alignment. It is thought that the symmetry breaking of structure induced by applied electric field is the origin of the 'optical activity' in the ER fluids. The electrically tunable 'optical activity' will find innovative applications in displays, optical devices and other fields

  20. Activity-Dependent Ubiquitination of GluA1 Mediates a Distinct AMPAR Endocytosis and Sorting Pathway

    Science.gov (United States)

    Schwarz, Lindsay A.; Hall, Benjamin J.; Patrick, Gentry N.

    2010-01-01

    The accurate trafficking of AMPA receptors (AMPARs) to and from the synapse is a critical component of learning and memory in the brain, while dysfunction of AMPAR trafficking is hypothesized to be an underlying mechanism of Alzheimer’s disease. Previous work has shown that ubiquitination of integral membrane proteins is a common post-translational modification used to mediate endocytosis and endocytic sorting of surface proteins in eukaryotic cells. Here we report that mammalian AMPARs become ubiquitinated in response to their activation. Using a mutant of GluA1 that is unable to be ubiquitinated at lysines on its carboxy-terminus, we demonstrate that ubiquitination is required for internalization of surface AMPARs and their trafficking to the lysosome in response to the AMPAR agonist AMPA, but not for internalization of AMPARs in response to the NMDA receptor (NMDAR) agonist NMDA. Through over-expression or RNAi-mediated knockdown, we identify that a specific E3 ligase, Nedd4-1, is necessary for this process. Finally, we show that ubiquitination of GluA1 by Nedd4-1 becomes more prevalent as neurons mature. Together, these data show that ubiquitination of GluA1-containing AMPARs by Nedd4-1 mediates their endocytosis and trafficking to the lysosome. Furthermore, these results provide insight into how hippocampal neurons regulate AMPAR trafficking and degradation with high specificity in response to differing neuronal signaling cues, and suggest that changes to this pathway may occur as neurons mature. PMID:21148011

  1. Optical limiting properties of optically active phthalocyanine derivatives

    Science.gov (United States)

    Wang, Peng; Zhang, Shuang; Wu, Peiji; Ye, Cheng; Liu, Hongwei; Xi, Fu

    2001-06-01

    The optical limiting properties of four optically active phthalocyanine derivatives in chloroform solutions and epoxy resin thin plates were measured at 532 nm with 10 ns pulses. The excited state absorption cross-section σex and refractive-index cross-section σr were determined with the Z-scan technique. These chromophores possess larger σex than the ground state absorption cross-section σ0, indicating that they are the potential materials for reverse saturable absorption (RSA). The negative σr values of these chromophores add to the thermal contribution, producing a larger defocusing effect, which may be helpful in further enhancing their optical limiting performance. The optical limiting responses of the thin plate samples are stronger than those of the chloroform solutions.

  2. Fiber optic strain measurements using an optically-active polymer

    Science.gov (United States)

    Buckley, Leonard J.; Neumeister, Gary C.

    1992-03-01

    A study encompassing the use of an optically-active polymer as the strain-sensing medium in an organic matrix composite was performed. Several compounds were synthesized for use as the inner cladding material for silica fiber-optic cores. These materials include a diacetylene containing polyamide. It is possible to dynamically modify the optical properties of these materials through changes in applied strain or temperature. By doing so the characteristic absorption in the visible is reversibly shifted to a higher energy state. The polymer-coated fiber-optic cores were initially studied in epoxy resin. Additionally, one of the polyamide/diacetylene polymers was studied in a spin-fiber form consisting of 15 micron filaments assembled in multifilament tows. The most promising configuration and materials were then investigated further by embedding in graphite/epoxy composite laminates. In each case the shift in the visible absorption peak was monitored as a function of applied mechanical strain.

  3. The LAM space active optics facility

    Science.gov (United States)

    Engel, C.; Ferrari, M.; Hugot, E.; Escolle, C.; Bonnefois, A.; Bernot, M.; Bret-Dibat, T.; Carlavan, M.; Falzon, F.; Fusco, T.; Laubier, D.; Liotard, A.; Michau, V.; Mugnier, L.

    2017-11-01

    The next generation of large lightweight space telescopes will require the use of active optics systems to enhance the performance and increase the spatial resolution. Since almost 10 years now, LAM, CNES, THALES and ONERA conjugate their experience and efforts for the development of space active optics through the validation of key technological building blocks: correcting devices, metrology components and control strategies. This article presents the work done so far on active correcting mirrors and wave front sensing, as well as all the facilities implemented. The last part of this paper focuses on the merging of the MADRAS and RASCASSE test-set up. This unique combination will provide to the active optics community an automated, flexible and versatile facility able to feed and characterise space active optics components.

  4. Responses of Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus to Simulated Food Processing Treatments, Determined Using Fluorescence-Activated Cell Sorting and Plate Counting▿

    Science.gov (United States)

    Kennedy, Deirdre; Cronin, Ultan P.; Wilkinson, Martin G.

    2011-01-01

    Three common food pathogenic microorganisms were exposed to treatments simulating those used in food processing. Treated cell suspensions were then analyzed for reduction in growth by plate counting. Flow cytometry (FCM) and fluorescence-activated cell sorting (FACS) were carried out on treated cells stained for membrane integrity (Syto 9/propidium iodide) or the presence of membrane potential [DiOC2(3)]. For each microbial species, representative cells from various subpopulations detected by FCM were sorted onto selective and nonselective agar and evaluated for growth and recovery rates. In general, treatments giving rise to the highest reductions in counts also had the greatest effects on cell membrane integrity and membrane potential. Overall, treatments that impacted cell membrane permeability did not necessarily have a comparable effect on membrane potential. In addition, some bacterial species with extensively damaged membranes, as detected by FCM, appeared to be able to replicate and grow after sorting. Growth of sorted cells from various subpopulations was not always reflected in plate counts, and in some cases the staining protocol may have rendered cells unculturable. Optimized FCM protocols generated a greater insight into the extent of the heterogeneous bacterial population responses to food control measures than did plate counts. This study underlined the requirement to use FACS to relate various cytometric profiles generated by various staining protocols with the ability of cells to grow on microbial agar plates. Such information is a prerequisite for more-widespread adoption of FCM as a routine microbiological analytical technique. PMID:21602370

  5. Activity-dependent ubiquitination of GluA1 mediates a distinct AMPA receptor endocytosis and sorting pathway.

    Science.gov (United States)

    Schwarz, Lindsay A; Hall, Benjamin J; Patrick, Gentry N

    2010-12-08

    The accurate trafficking of AMPA receptors (AMPARs) to and from the synapse is a critical component of learning and memory in the brain, whereas dysfunction of AMPAR trafficking is hypothesized to be an underlying mechanism of Alzheimer's disease. Previous work has shown that ubiquitination of integral membrane proteins is a common posttranslational modification used to mediate endocytosis and endocytic sorting of surface proteins in eukaryotic cells. Here we report that mammalian AMPARs become ubiquitinated in response to their activation. Using a mutant of GluA1 that is unable to be ubiquitinated at lysines on its C-terminus, we demonstrate that ubiquitination is required for internalization of surface AMPARs and their trafficking to the lysosome in response to the AMPAR agonist AMPA but not for internalization of AMPARs in response to the NMDA receptor agonist NMDA. Through overexpression or RNA interference-mediated knockdown, we identify that a specific E3 ligase, Nedd4-1 (neural-precursor cell-expressed developmentally downregulated gene 4-1), is necessary for this process. Finally, we show that ubiquitination of GluA1 by Nedd4-1 becomes more prevalent as neurons mature. Together, these data show that ubiquitination of GluA1-containing AMPARs by Nedd4-1 mediates their endocytosis and trafficking to the lysosome. Furthermore, these results provide insight into how hippocampal neurons regulate AMPAR trafficking and degradation with high specificity in response to differing neuronal signaling cues and suggest that changes to this pathway may occur as neurons mature.

  6. A multicenter study to standardize reporting and analyses of fluorescence-activated cell-sorted murine intestinal epithelial cells

    Science.gov (United States)

    Magness, Scott T.; Puthoff, Brent J.; Crissey, Mary Ann; Dunn, James; Henning, Susan J.; Houchen, Courtney; Kaddis, John S.; Kuo, Calvin J.; Li, Linheng; Lynch, John; Martin, Martin G.; May, Randal; Niland, Joyce C.; Olack, Barbara; Qian, Dajun; Stelzner, Matthias; Swain, John R.; Wang, Fengchao; Wang, Jiafang; Wang, Xinwei; Yan, Kelley; Yu, Jian

    2013-01-01

    Fluorescence-activated cell sorting (FACS) is an essential tool for studies requiring isolation of distinct intestinal epithelial cell populations. Inconsistent or lack of reporting of the critical parameters associated with FACS methodologies has complicated interpretation, comparison, and reproduction of important findings. To address this problem a comprehensive multicenter study was designed to develop guidelines that limit experimental and data reporting variability and provide a foundation for accurate comparison of data between studies. Common methodologies and data reporting protocols for tissue dissociation, cell yield, cell viability, FACS, and postsort purity were established. Seven centers tested the standardized methods by FACS-isolating a specific crypt-based epithelial population (EpCAM+/CD44+) from murine small intestine. Genetic biomarkers for stem/progenitor (Lgr5 and Atoh 1) and differentiated cell lineages (lysozyme, mucin2, chromogranin A, and sucrase isomaltase) were interrogated in target and control populations to assess intra- and intercenter variability. Wilcoxon's rank sum test on gene expression levels showed limited intracenter variability between biological replicates. Principal component analysis demonstrated significant intercenter reproducibility among four centers. Analysis of data collected by standardized cell isolation methods and data reporting requirements readily identified methodological problems, indicating that standard reporting parameters facilitate post hoc error identification. These results indicate that the complexity of FACS isolation of target intestinal epithelial populations can be highly reproducible between biological replicates and different institutions by adherence to common cell isolation methods and FACS gating strategies. This study can be considered a foundation for continued method development and a starting point for investigators that are developing cell isolation expertise to study physiology and

  7. Development and implementation of a visual card-sorting technique for assessing food and activity preferences and patterns in African American girls.

    Science.gov (United States)

    Sherwood, Nancy E; Story, Mary; Neumark-Sztainer, Dianne; Adkins, Sarah; Davis, Marsha

    2003-11-01

    Card-sorting tasks for assessing food and activity preferences and patterns among African American girls were developed. Associations among food preference and intake frequency, activity preference and frequency, and body mass index were examined. Participants completed newly developed card-sorting tasks assessing food and activity preferences and patterns. Height and weight were measured. Ninety-six 8- to 10-year-old African American girls from schools and community centers in Minneapolis-St. Paul. Preference and frequency data for 64 foods/beverages and 34 activities. Frequencies for food and activity preference and frequency categories were computed. Pearson correlations among food and activity preference, frequency, and body mass index were computed. High-sugar (eg, fruit drinks, soda) and/or high-fat (eg, ice cream, cookies) foods were among the most popular and frequently consumed. Ninety-six percent of girls liked fruit drinks, with 35% consuming them "almost every day." Less-structured activities such as biking, games, jump rope, and dance were most popular. Biking was preferred by 85% of girls, with 48% biking "almost every day." Food preference and frequency categories were moderately correlated (r=0.30 to 0.58), as were activity preference and frequency (r=0.37 to 0.49). The card-sorting tasks are useful tools for assessing food and activity preferences and patterns in girls. Obesity prevention programs for African American girls should include preferred activities such as dance, jump rope, and active play. Programs may also benefit from a focus on replacing high fat/high sugar snacks and sweetened beverages with low-fat, lower-calorie snacks and beverages (eg, fruit, vegetables, water).

  8. Parallel sorting algorithms

    CERN Document Server

    Akl, Selim G

    1985-01-01

    Parallel Sorting Algorithms explains how to use parallel algorithms to sort a sequence of items on a variety of parallel computers. The book reviews the sorting problem, the parallel models of computation, parallel algorithms, and the lower bounds on the parallel sorting problems. The text also presents twenty different algorithms, such as linear arrays, mesh-connected computers, cube-connected computers. Another example where algorithm can be applied is on the shared-memory SIMD (single instruction stream multiple data stream) computers in which the whole sequence to be sorted can fit in the

  9. Photovoltaic concentrator assembly with optically active cover

    Science.gov (United States)

    Plesniak, Adam P

    2014-01-21

    A photovoltaic concentrator assembly that includes a housing that defines an internal volume and includes a rim, wherein the rim defines an opening into the internal volume, a photovoltaic cell positioned in the internal volume, and an optical element that includes an optically active body and a flange extending outward from the body, wherein the flange is sealingly engaged with the rim of the housing to enclose the internal volume.

  10. Raman Optical Activity of Biological Molecules

    Science.gov (United States)

    Blanch, Ewan W.; Barron, Laurence D.

    Now an incisive probe of biomolecular structure, Raman optical activity (ROA) measures a small difference in Raman scattering from chiral molecules in right- and left-circularly polarized light. As ROA spectra measure vibrational optical activity, they contain highly informative band structures sensitive to the secondary and tertiary structures of proteins, nucleic acids, viruses and carbohydrates as well as the absolute configurations of small molecules. In this review we present a survey of recent studies on biomolecular structure and dynamics using ROA and also a discussion of future applications of this powerful new technique in biomedical research.

  11. 3D-printed optical active components

    Science.gov (United States)

    Suresh Nair, S.; Nuding, J.; Heinrich, A.

    2018-02-01

    Additive Manufacturing (AM) has the potential to become a powerful tool in the realization of complex optical components. The primary advantage that meets the eye, is that fabrication of geometrically complicated optical structures is made easier in AM as compared to the conventional fabrication methods (using molds for instance). But this is not the only degree of freedom that AM has to offer. With the multitude of materials suitable for AM in the market, it is possible to introduce functionality into the components one step before fabrication: by altering the raw material. A passive example would be to use materials with varying properties together, in a single manufacturing step, constructing samples with localized refractive indices for instance. An active approach is to blend in materials with distinct properties into the photopolymer resin and manufacturing with this composite material. Our research is currently focused in this direction, with the desired optical property to be introduced being Photoluminescence. Formation of nanocomposite mixtures to produce samples is the current approach. With this endeavor, new sensor systems can be realized, which may be used to measure the absorption spectra of biological samples. Thereby the sample compartment, the optics and the spectral light source (different quantum dots) are 3D-printed in one run. This component can be individually adapted to the biological sample with respect to wavelength, optical and mechanical properties. Here we would like to present our work on the additive manufacturing of an active optical component. Based on the stereolithography method, a monolithic optical component was 3D-printed, showing light emission at different defined wavelengths due to UV excited quantum dots inside the 3D-printed optics.

  12. PENERAPAN MODEL ACTIVE LEARNING PERMAINAN CARD SORT UNTUK MENINGKATKAN AKTIVITAS DAN HASIL BELAJAR MATEMATIKA SISWA KELAS IV SDN 05 METRO SELATAN

    Directory of Open Access Journals (Sweden)

    Muncarno Muncarno

    2015-12-01

    Full Text Available This research was motivated by the low activities and student learning outcomes on mathematics. The purpose of this research was to increase the activities and student learning outcomes on mathematics by applying the active learning model of card sort game. The method of this research was classroom action research that consist of planning, implementation, observation, and reflection. The instrument of data collection used was observation sheet and test questions. The technique of analysis data used were qualitative analysis and quantitative analysis. The results of this research showed that aplication of active learning model of card sort game on mathematics learning can increase the activities and student learning outcomes. It can be showed that students learning completeness reached 75%, the average activities of students in the first cycle were 59.80% and 78.39% in the second cycle with the increasing of 18.59%. The average student learning outcomes in the first cycle and the second cycle were 69.52 78.70, with an increase of 9.18.

  13. Sorting a distribution theory

    CERN Document Server

    Mahmoud, Hosam M

    2011-01-01

    A cutting-edge look at the emerging distributional theory of sorting Research on distributions associated with sorting algorithms has grown dramatically over the last few decades, spawning many exact and limiting distributions of complexity measures for many sorting algorithms. Yet much of this information has been scattered in disparate and highly specialized sources throughout the literature. In Sorting: A Distribution Theory, leading authority Hosam Mahmoud compiles, consolidates, and clarifies the large volume of available research, providing a much-needed, comprehensive treatment of the

  14. Active optical cable for intrasatellite communications

    Science.gov (United States)

    Blasco, J.; Cano, D.; Navasquillo, O.; Esteban, M. A.

    2017-11-01

    DAS Photonics and Airbus Defence and Space (Spain) have been working for more than six years in the concept of an Active Optical Cable (AOC) for copper cable substitution. The main advantages that AOC offers are significant mass and size saving, better flexibility and routing of the cable and immunity to EMI.

  15. Surface enhanced Raman optical activity (SEROA)

    DEFF Research Database (Denmark)

    Abdali, Salim; Blanch, E.W.

    2008-01-01

    Raman optical activity (ROA) directly monitors the stereochemistry of chiral molecules and is now an incisive probe of biomolecular structure. ROA spectra contain a wealth of information on tertiary folding, secondary structure and even the orientation of individual residues in proteins and nucleic...

  16. Sorting waves and associated eigenvalues

    Science.gov (United States)

    Carbonari, Costanza; Colombini, Marco; Solari, Luca

    2017-04-01

    The presence of mixed sediment always characterizes gravel bed rivers. Sorting processes take place during bed load transport of heterogeneous sediment mixtures. The two main elements necessary to the occurrence of sorting are the heterogeneous character of sediments and the presence of an active sediment transport. When these two key ingredients are simultaneously present, the segregation of bed material is consistently detected both in the field [7] and in laboratory [3] observations. In heterogeneous sediment transport, bed altimetric variations and sorting always coexist and both mechanisms are independently capable of driving the formation of morphological patterns. Indeed, consistent patterns of longitudinal and transverse sorting are identified almost ubiquitously. In some cases, such as bar formation [2] and channel bends [5], sorting acts as a stabilizing effect and therefore the dominant mechanism driving pattern formation is associated with bed altimetric variations. In other cases, such as longitudinal streaks, sorting enhances system instability and can therefore be considered the prevailing mechanism. Bedload sheets, first observed by Khunle and Southard [1], represent another classic example of a morphological pattern essentially triggered by sorting, as theoretical [4] and experimental [3] results suggested. These sorting waves cause strong spatial and temporal fluctuations of bedload transport rate typical observed in gravel bed rivers. The problem of bed load transport of a sediment mixture is formulated in the framework of a 1D linear stability analysis. The base state consists of a uniform flow in an infinitely wide channel with active bed load transport. The behaviour of the eigenvalues associated with fluid motion, bed evolution and sorting processes in the space of the significant flow and sediment parameters is analysed. A comparison is attempted with the results of the theoretical analysis of Seminara Colombini and Parker [4] and Stecca

  17. Magnethophoretic sorting of fluid catalytic cracking particles

    NARCIS (Netherlands)

    Solsona, Miguel; Nieuwelink, A. E.; Odijk, Mathieu; Meirer, Florian; Abelmann, Leon; Olthuis, Wouter; Weckhuysen, Bert M.; van den Berg, Albert; Lee, Abraham; DeVoe, Don

    2017-01-01

    We demonstrate an on-chip particle activity sorter, focused on iron concentration and based on magnetophoresis. This device was used for fast sorting of stepwise homogenously distributed [Fe]s. The preliminary results are very encouraging. We show that we can sort particles on magnetic moment, with

  18. Sorting out Downside Beta

    NARCIS (Netherlands)

    G.T. Post (Thierry); P. van Vliet (Pim); S.D. Lansdorp (Simon)

    2009-01-01

    textabstractDownside risk, when properly defined and estimated, helps to explain the cross-section of US stock returns. Sorting stocks by a proper estimate of downside market beta leads to a substantially larger cross-sectional spread in average returns than sorting on regular market beta. This

  19. Three Sorts of Naturalism

    DEFF Research Database (Denmark)

    Fink, Hans

    2006-01-01

    In "Two sorts of Naturalism" John McDowell is sketching his own sort of naturalism in ethics as an alternative to "bald naturalism". In this paper I distinguish materialist, idealist and absolute conceptions of nature and of naturalism in order to provide a framework for a clearer understanding...

  20. Identification of microbes from the surfaces of food-processing lines based on the flow cytometric evaluation of cellular metabolic activity combined with cell sorting.

    Science.gov (United States)

    Juzwa, W; Duber, A; Myszka, K; Białas, W; Czaczyk, K

    2016-09-01

    In this study the design of a flow cytometry-based procedure to facilitate the detection of adherent bacteria from food-processing surfaces was evaluated. The measurement of the cellular redox potential (CRP) of microbial cells was combined with cell sorting for the identification of microorganisms. The procedure enhanced live/dead cell discrimination owing to the measurement of the cell physiology. The microbial contamination of the surface of a stainless steel conveyor used to process button mushrooms was evaluated in three independent experiments. The flow cytometry procedure provided a step towards monitoring of contamination and enabled the assessment of microbial food safety hazards by the discrimination of active, mid-active and non-active bacterial sub-populations based on determination of their cellular vitality and subsequently single cell sorting to isolate microbial strains from discriminated sub-populations. There was a significant correlation (r = 0.97; p vitality and the identification of species from defined sub-populations, although the identified microbes were limited to culturable cells.

  1. Perbandingan Kecepatan Gabungan Algoritma Quick Sort dan Merge Sort dengan Insertion Sort, Bubble Sort dan Selection Sort

    OpenAIRE

    Al Rivan, Muhammad Ezar

    2017-01-01

    Ordering is one of the process done before doing data processing. The sorting algorithm has its own strengths and weaknesses. By taking strengths of each algorithm then combined can be a better algorithm. Quick Sort and Merge Sort are algorithms that divide the data into parts and each part divide again into sub-section until one element. Usually one element join with others and then sorted by. In this experiment data divide into parts that have size not more than threshold. This part then so...

  2. Active Star Architectures For Fiber Optics Ethernet

    Science.gov (United States)

    Linde, Yoseph L.

    1988-12-01

    Ethernet, and the closely related IEEE 802.3 CSMA/CD standard (Carrier Sense Multiple Access with Collision Detection), is probably the widest used method for high speed Local Area Networks (LANs). The original Ethernet medium was baseband coax but the wide acceptance of the system necessitated the ability to use Ethernet on a variety of media. So far the use of Ethernet on Thin Coax (CheaperNet), Twisted Pair (StarLan) and Broadband Coax has been standardized. Recently, an increased interest in Fiber Optic based LANs resulted in a formation of an IEEE group whose charter is to recommend approaches for Active and Passive Fiber Optic Ethernet systems. The various approaches which are being considered are described in this paper with an emphasis on Active Star based systems.

  3. Integration of active and passive polymer optics

    DEFF Research Database (Denmark)

    Christiansen, Mads Brøkner; Schøler, Mikkel; Kristensen, Anders

    2007-01-01

    We demonstrate a wafer scale fabrication process for integration of active and passive polymer optics: Polymer DFB lasers and waveguides. Polymer dye DFB lasers are fabricated by combined nanoimprint and photolithography (CNP). The CNP fabrication relies on an UV transparent stamp with nm sized...... wavelength from temperature and refractive index changes in the surroundings is investigated, pointing towards the use of the described fabrication method for on-chip polymer sensor systems....

  4. Surface acoustic wave actuated cell sorting (SAWACS).

    Science.gov (United States)

    Franke, T; Braunmüller, S; Schmid, L; Wixforth, A; Weitz, D A

    2010-03-21

    We describe a novel microfluidic cell sorter which operates in continuous flow at high sorting rates. The device is based on a surface acoustic wave cell-sorting scheme and combines many advantages of fluorescence activated cell sorting (FACS) and fluorescence activated droplet sorting (FADS) in microfluidic channels. It is fully integrated on a PDMS device, and allows fast electronic control of cell diversion. We direct cells by acoustic streaming excited by a surface acoustic wave which deflects the fluid independently of the contrast in material properties of deflected objects and the continuous phase; thus the device underlying principle works without additional enhancement of the sorting by prior labelling of the cells with responsive markers such as magnetic or polarizable beads. Single cells are sorted directly from bulk media at rates as fast as several kHz without prior encapsulation into liquid droplet compartments as in traditional FACS. We have successfully directed HaCaT cells (human keratinocytes), fibroblasts from mice and MV3 melanoma cells. The low shear forces of this sorting method ensure that cells survive after sorting.

  5. Sorting Out Seasonal Allergies

    Science.gov (United States)

    ... Close ‹ Back to Healthy Living Sorting Out Seasonal Allergies Sneezing, runny nose, nasal congestion. Symptoms of the ... How do I know if I have seasonal allergies? According to Dr. Georgeson, the best way to ...

  6. Wage Sorting Trends

    DEFF Research Database (Denmark)

    Bagger, Jesper; Vejlin, Rune Majlund; Sørensen, Kenneth Lykke

    Using a population-wide Danish Matched Employer-Employee panel from 1980-2006, we document a strong trend towards more positive assortative wage sorting. The correlation between worker and firm fixed effects estimated from a log wage regression increases from -0.07 in 1981 to .14 in 2001. The non......Using a population-wide Danish Matched Employer-Employee panel from 1980-2006, we document a strong trend towards more positive assortative wage sorting. The correlation between worker and firm fixed effects estimated from a log wage regression increases from -0.07 in 1981 to .14 in 2001....... The nonstationary wage sorting pattern is not due to compositional changes in the labor market, primarily occurs among high wage workers, and comprises 41 percent of the increase in the standard deviation of log real wages between 1980 and 2006. We show that the wage sorting trend is associated with worker...

  7. Seamless Combination of Fluorescence-Activated Cell Sorting and Hanging-Drop Networks for Individual Handling and Culturing of Stem Cells and Microtissue Spheroids.

    Science.gov (United States)

    Birchler, Axel; Berger, Mischa; Jäggin, Verena; Lopes, Telma; Etzrodt, Martin; Misun, Patrick Mark; Pena-Francesch, Maria; Schroeder, Timm; Hierlemann, Andreas; Frey, Olivier

    2016-01-19

    Open microfluidic cell culturing devices offer new possibilities to simplify loading, culturing, and harvesting of individual cells or microtissues due to the fact that liquids and cells/microtissues are directly accessible. We present a complete workflow for microfluidic handling and culturing of individual cells and microtissue spheroids, which is based on the hanging-drop network concept: The open microfluidic devices are seamlessly combined with fluorescence-activated cell sorting (FACS), so that individual cells, including stem cells, can be directly sorted into specified culturing compartments in a fully automated way and at high accuracy. Moreover, already assembled microtissue spheroids can be loaded into the microfluidic structures by using a conventional pipet. Cell and microtissue culturing is then performed in hanging drops under controlled perfusion. On-chip drop size control measures were applied to stabilize the system. Cells and microtissue spheroids can be retrieved from the chip by using a parallelized transfer method. The presented methodology holds great promise for combinatorial screening of stem-cell and multicellular-spheroid cultures.

  8. Anti-Hermitian photodetector facilitating efficient subwavelength photon sorting.

    Science.gov (United States)

    Kim, Soo Jin; Kang, Ju-Hyung; Mutlu, Mehmet; Park, Joonsuk; Park, Woosung; Goodson, Kenneth E; Sinclair, Robert; Fan, Shanhui; Kik, Pieter G; Brongersma, Mark L

    2018-01-22

    The ability to split an incident light beam into separate wavelength bands is central to a diverse set of optical applications, including imaging, biosensing, communication, photocatalysis, and photovoltaics. Entirely new opportunities are currently emerging with the recently demonstrated possibility to spectrally split light at a subwavelength scale with optical antennas. Unfortunately, such small structures offer limited spectral control and are hard to exploit in optoelectronic devices. Here, we overcome both challenges and demonstrate how within a single-layer metafilm one can laterally sort photons of different wavelengths below the free-space diffraction limit and extract a useful photocurrent. This chipscale demonstration of anti-Hermitian coupling between resonant photodetector elements also facilitates near-unity photon-sorting efficiencies, near-unity absorption, and a narrow spectral response (∼ 30 nm) for the different wavelength channels. This work opens up entirely new design paradigms for image sensors and energy harvesting systems in which the active elements both sort and detect photons.

  9. Bio-optofluidics and Bio-photonics: Programmable Phase Optics activities at DTU Fotonik

    DEFF Research Database (Denmark)

    Bañas, Andrew Rafael; Palima, Darwin; Pedersen, Finn

    We present ongoing research and development activities for constructing a compact next generation BioPhotonics Workstation and a Bio-optofluidic Cell Sorter (cell-BOCS) for all-optical micromanipulation platforms utilizing low numerical aperture beam geometries. Unlike conventional high NA optical...... tweezers, the BioPhotonics workstation is e.g. capable of long range 3D manipulation. This enables a variety of biological studies such as manipulation of intricate microfabricated assemblies or for automated and parallel optofluidic cell sorting. To further reduce its overhead, we propose ways of making...... the BioPhotonics Workstation platform more photon efficient by studying the 3D distribution of the counter propagating beams and utilizing the Generalized Phase Contrast (GPC) method for illuminating the applied spatial light modulators....

  10. What is a Sorting Function?

    DEFF Research Database (Denmark)

    Henglein, Fritz

    2009-01-01

    What is a sorting function—not a sorting function for a given ordering relation, but a sorting function with nothing given? Formulating four basic properties of sorting algorithms as defining requirements, we arrive at intrinsic notions of sorting and stable sorting: A function is a sorting...... are derivable without compromising data abstraction. Finally we point out that stable sorting functions as default representations of ordering relations have the advantage of permitting linear-time sorting algorithms; inequality tests forfeit this possibility....... function if and only it is an intrinsically parametric permutation function. It is a stable sorting function if and only if it is an intrinsically stable permutation function. We show that ordering relations can be represented isomorphically as inequality tests, comparators and stable sorting functions...

  11. Active learning in optics for girls

    Science.gov (United States)

    Ali, R.; Ashraf, I.

    2017-08-01

    Active learning in Optics (ALO) is a self-funded program under the umbrella of the Abdus Salam International Centre for Theoretical Physics (ICTP) and Quaid-i-Azam University (QAU) to bring physical sciences to traditionally underserved Girls high schools and colleges in Pakistan. There is a significant gender disparity in physical Sciences in Pakistan. In Department of Physics at QAU, approximately 10 to 20% of total students were used to be females from past many decades, but now this percentage is increasing. To keep it up at same pace, we started ALO in January 2016 as a way to provide girls an enriching science experiences, in a very friendly atmosphere. We have organized many one-day activities, to support and encourage girls' students of government high schools and colleges to pursue careers in sciences. In this presentation we will describe our experience and lesson learned in these activities.

  12. ViSAPy: a Python tool for biophysics-based generation of virtual spiking activity for evaluation of spike-sorting algorithms.

    Science.gov (United States)

    Hagen, Espen; Ness, Torbjørn V; Khosrowshahi, Amir; Sørensen, Christina; Fyhn, Marianne; Hafting, Torkel; Franke, Felix; Einevoll, Gaute T

    2015-04-30

    New, silicon-based multielectrodes comprising hundreds or more electrode contacts offer the possibility to record spike trains from thousands of neurons simultaneously. This potential cannot be realized unless accurate, reliable automated methods for spike sorting are developed, in turn requiring benchmarking data sets with known ground-truth spike times. We here present a general simulation tool for computing benchmarking data for evaluation of spike-sorting algorithms entitled ViSAPy (Virtual Spiking Activity in Python). The tool is based on a well-established biophysical forward-modeling scheme and is implemented as a Python package built on top of the neuronal simulator NEURON and the Python tool LFPy. ViSAPy allows for arbitrary combinations of multicompartmental neuron models and geometries of recording multielectrodes. Three example benchmarking data sets are generated, i.e., tetrode and polytrode data mimicking in vivo cortical recordings and microelectrode array (MEA) recordings of in vitro activity in salamander retinas. The synthesized example benchmarking data mimics salient features of typical experimental recordings, for example, spike waveforms depending on interspike interval. ViSAPy goes beyond existing methods as it includes biologically realistic model noise, synaptic activation by recurrent spiking networks, finite-sized electrode contacts, and allows for inhomogeneous electrical conductivities. ViSAPy is optimized to allow for generation of long time series of benchmarking data, spanning minutes of biological time, by parallel execution on multi-core computers. ViSAPy is an open-ended tool as it can be generalized to produce benchmarking data or arbitrary recording-electrode geometries and with various levels of complexity. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Vibrational optical activity principles and applications

    CERN Document Server

    Nafie, Laurence A

    2011-01-01

    This unique book stands as the only comprehensive introduction to vibrational optical activity (VOA) and is the first single book that serves as a complete reference for this relatively new, but increasingly important area of molecular spectroscopy. Key features:A single-source reference on this topic that introduces, describes the background and foundation of this area of spectroscopy.Serves as a guide on how to use it to carry out applications with relevant problem solving.Depth and breadth of the subject is presented in a logical, complete and progressive fashion. A

  14. LazySorted: A Lazily, Partially Sorted Python List

    Directory of Open Access Journals (Sweden)

    Naftali Harris

    2015-06-01

    Full Text Available LazySorted is a Python C extension implementing a partially and lazily sorted list data structure. It solves a common problem faced by programmers, in which they need just part of a sorted list, like its middle element (the median, but sort the entire list to get it. LazySorted presents them with the abstraction that they are working with a fully sorted list, while actually only sorting the list partially with quicksort partitions to return the requested sub-elements. This enables programmers to use naive "sort first" algorithms but nonetheless attain linear run-times when possible. LazySorted may serve as a drop-in replacement for the built-in sorted function in most cases, and can sometimes achieve run-times more than 7 times faster.

  15. Active Full-Shell Grazing-Incidence Optics

    Science.gov (United States)

    Davis, Jacqueline M.; Elsner, Ronald F.; Ramsey, Brian D.; O'Dell, Stephen L.; Kolodziejczak, Jeffery; Weisskopf, Martin C.; Gubarev, Mikhail V.

    2016-01-01

    MSFC has a long history of developing full-shell grazing-incidence x-ray optics for both narrow (pointed) and wide field (surveying) applications. The concept presented in this paper shows the potential to use active optics to switch between narrow and wide-field geometries, while maintaining large effective area and high angular resolution. In addition, active optics has the potential to reduce errors due to mounting and manufacturing lightweight optics. The design presented corrects low spatial frequency error and has significantly fewer actuators than other concepts presented thus far in the field of active x-ray optics. Using a finite element model, influence functions are calculated using active components on a full-shell grazing-incidence optic. Next, the ability of the active optic to effect a change of optical prescription and to correct for errors due to manufacturing and mounting is modeled.

  16. Ready, steady, SORT!

    CERN Document Server

    Laëtitia Pedroso

    2010-01-01

    The selective or ecological sorting of waste is already second nature to many of us and concerns us all. As the GS Department's new awareness-raising campaign reminds us, everything we do to sort waste contributes to preserving the environment.    Placemats printed on recycled paper using vegetable-based ink will soon be distributed in Restaurant No.1.   Environmental protection is never far from the headlines, and CERN has a responsibility to ensure that the 3000 tonnes and more of waste it produces every year are correctly and selectively sorted. Materials can be given a second life through recycling and re-use, thereby avoiding pollution from landfill sites and incineration plants and saving on processing costs. The GS Department is launching a new poster campaign designed to raise awareness of the importance of waste sorting and recycling. "After conducting a survey to find out whether members of the personnel were prepared to make an effort to sort a...

  17. Magnet sorting algorithms

    International Nuclear Information System (INIS)

    Dinev, D.

    1996-01-01

    Several new algorithms for sorting of dipole and/or quadrupole magnets in synchrotrons and storage rings are described. The algorithms make use of a combinatorial approach to the problem and belong to the class of random search algorithms. They use an appropriate metrization of the state space. The phase-space distortion (smear) is used as a goal function. Computational experiments for the case of the JINR-Dubna superconducting heavy ion synchrotron NUCLOTRON have shown a significant reduction of the phase-space distortion after the magnet sorting. (orig.)

  18. Sorting and sustaining cooperation

    DEFF Research Database (Denmark)

    Vikander, Nick

    2013-01-01

    This paper looks at cooperation in teams where some people are selfish and others are conditional cooperators, and where lay-offs will occur at a fixed future date. I show that the best way to sustain cooperation prior to the lay-offs is often in a sorting equilibrium, where conditional cooperators...... can identify and then work with one another. Changes to parameters that would seem to make cooperation more attractive, such as an increase in the discount factor or the fraction of conditional cooperators, can reduce equilibrium cooperation if they decrease a selfish player's incentive to sort....

  19. Three Sorts of Naturalism

    OpenAIRE

    Fink, Hans

    2006-01-01

    In "Two sorts of Naturalism" John McDowell is sketching his own sort of naturalism in ethics as an alternative to "bald naturalism". In this paper I distinguish materialist, idealist and absolute conceptions of nature and of naturalism in order to provide a framework for a clearer understanding of what McDowell's own naturalism amounts to. I argue that nothing short of an absolute naturalism will do for a number of McDowell's own purposes, but that it is far from obvious that this is his posi...

  20. Aharonov-Bohm effect in optical activity

    International Nuclear Information System (INIS)

    Tan, C Z

    2010-01-01

    Optically active media have the helical and dissymmetric crystal structure, which constrains the motions of the electrons to a helical path under the influence of the incident electric field. The charge flow along the helices induces a magnetic field in the direction of the axis of helices. The helical structure hence acts as natural micro-solenoids for the electromagnetic waves passing through them. Optical rotation is related to the difference in the accumulative Aharonov-Bohm (AB) phase between the right- and the left-circularly polarized waves. The AB phase is proportional to the angular momentum of an electron moving around the micro-solenoid. Originally the AB phase is shown to be a continuous function of the magnetic flux. However, quantization of the geometrical angular momentum leads to the quantized AB phase. The rotatory power and the Verdet constant are proportional to the refractive index of the medium. The quantized current in the micro-solenoid is proportional to the Bohr magneton and inversely proportional to the area of the helices.

  1. Vibrational Raman optical activity of ketose monosaccharides

    Science.gov (United States)

    Bell, Alasdair F.; Hecht, Lutz; Barron, Laurence D.

    1995-07-01

    The vibrational Raman optical activity (ROA) spectra of the four ketose sugars D-fructose, L-sorbose, D-tagatose and D-psicose in aqueous solution, which have been measured in backscattering in the range ≈250-1500 cm -1, are reported. These results are combined with those from a previous ROA study of aldose and pentose sugars in an attempt to establish new vibrational assignments and to verify old ones. The high information content of these spectra provides a new perspective on all the central features of monosaccharide stereochemistry including dominant anomeric configuration, ring conformation, exocyclic CH 2OH group conformation and relative disposition of the hydroxyl groups around the ring.

  2. Experiments of the origins of optical activity.

    Science.gov (United States)

    Bonner, W A; Flores, J J

    1975-01-01

    Two recent reports claim that (1) aqueous L-aspartic acid polymerizes faster than D-Asp in the presence of kaolin at 90 degrees, and (2) L-phenylalanine is adsorbed by kaolin more extensively than D-Phe at pH 4(the reverse being true at pH2). The novelty of these observations and their potential significance for the origin of optical activity has prompted us to duplicate these experiments using more sensitive methods. L- and D, L-Asp in 0.01 M solution were incubated with kaolin at 90 degrees for 8 days. Careful examination of the aqueous residues from such experiments failed to demonstrate any preferential polymerization of L-Asp over D-Asp, or indeed any significant gross polymerization of Asp at all. In other experiments 0.001 M solutions of D, L-Phe at pH 6 and pH 2 were stirred with large excesses of kaolin for 24 hr, and the aqueous extracts from these mixtures were examined for gross adsorption using the amino acid analyzer. No significant gross adsorption was noted. We then looked for asymmetric adsorption in the aqueous residues using optical rotatory dispersion, gas chromatography and thin layer chromatography. By none of these analytical criteria could we find any evidence whatsoever for the preferential adsorption of D- versus L-Phe from either pH 6 or pH 2 solutions. Finally, in experiments bearing on the origin of optical activity by parity violation during beta-decay, we have irradiated solid samples of D-, L- and D,L-leucine in a 61700 Ci Sr-90 source at Oak Ridge National Lab. for 1.34 yr (total dose: 4.2 x 10(8) rad). Gas chromatographic examination of the (appropriately derivitized) recovered samples showed that the L-Leu was 16.7% decomposed, the D-Leu 11.4% and theD,L-Leu 13.8% decomposed. The recovered D,L-Leu sample had a gas-chromatographically determined enantiomeric composition of 50.8% D-leu and 49.2% L-Leu. These data, though very close to experimental error, may indicate a slight preferential radiolysis of L-Leu compared to D-Leu by the

  3. SorLA controls neurotrophic activity by sorting of GDNF and its receptors GFRα1 and RET

    DEFF Research Database (Denmark)

    Glerup, Simon; Lume, Maria; Olsen, Ditte

    2013-01-01

    is targeted to lysosomes and degraded while GFRα1 recycles, creating an efficient GDNF clearance pathway. The SorLA/GFRα1 complex further targets RET for endocytosis but not for degradation, affecting GDNF-induced neurotrophic activities. SorLA-deficient mice display elevated GDNF levels, altered dopaminergic...

  4. Yeast carboxypeptidase Y requires glycosylation for efficient intracellular transport, but not for vacuolar sorting, in vivo stability, or activity

    DEFF Research Database (Denmark)

    Winther, Jakob R.; Stevens, T H; Kielland-Brandt, Morten

    1991-01-01

    Functions of the carbohydrate side chains of the yeast vacuolar enzyme carboxypeptidase Y (CPY) were investigated by removal, through site-directed mutagenesis, of the sequences which act as signals for N-linked glycosylation. The mutant forms of the enzyme were analysed with respect to activity...

  5. Adaptor Protein Complex-2 (AP-2) and Epsin-1 Mediate Protease-activated Receptor-1 Internalization via Phosphorylation- and Ubiquitination-dependent Sorting Signals*

    Science.gov (United States)

    Chen, Buxin; Dores, Michael R.; Grimsey, Neil; Canto, Isabel; Barker, Breann L.; Trejo, JoAnn

    2011-01-01

    Signaling by protease-activated receptor-1 (PAR1), a G protein-coupled receptor (GPCR) for thrombin, is regulated by desensitization and internalization. PAR1 desensitization is mediated by β-arrestins, like most classic GPCRs. In contrast, internalization of PAR1 occurs through a clathrin- and dynamin-dependent pathway independent of β-arrestins. PAR1 displays two modes of internalization. Constitutive internalization of unactivated PAR1 is mediated by the clathrin adaptor protein complex-2 (AP-2), where the μ2-adaptin subunit binds directly to a tyrosine-based motif localized within the receptor C-tail domain. However, AP-2 depletion only partially inhibits agonist-induced internalization of PAR1, suggesting a function for other clathrin adaptors in this process. Here, we now report that AP-2 and epsin-1 are both critical mediators of agonist-stimulated PAR1 internalization. We show that ubiquitination of PAR1 and the ubiquitin-interacting motifs of epsin-1 are required for epsin-1-dependent internalization of activated PAR1. In addition, activation of PAR1 promotes epsin-1 de-ubiquitination, which may increase its endocytic adaptor activity to facilitate receptor internalization. AP-2 also regulates activated PAR1 internalization via recognition of distal C-tail phosphorylation sites rather than the canonical tyrosine-based motif. Thus, AP-2 and epsin-1 are both required to promote efficient internalization of activated PAR1 and recognize discrete receptor sorting signals. This study defines a new pathway for internalization of mammalian GPCRs. PMID:21965661

  6. Event shape sorting

    International Nuclear Information System (INIS)

    Kopecna, Renata; Tomasik, Boris

    2016-01-01

    We propose a novel method for sorting events of multiparticle production according to the azimuthal anisotropy of their momentum distribution. Although the method is quite general, we advocate its use in analysis of ultra-relativistic heavy-ion collisions where a large number of hadrons is produced. The advantage of our method is that it can automatically sort out samples of events with histograms that indicate similar distributions of hadrons. It takes into account the whole measured histograms with all orders of anisotropy instead of a specific observable (e.g., v 2 , v 3 , q 2 ). It can be used for more exclusive experimental studies of flow anisotropies which are then more easily compared to theoretical calculations. It may also be useful in the construction of mixed-events background for correlation studies as it allows to select events with similar momentum distribution. (orig.)

  7. A Sequence of Sorting Strategies.

    Science.gov (United States)

    Duncan, David R.; Litwiller, Bonnie H.

    1984-01-01

    Describes eight increasingly sophisticated and efficient sorting algorithms including linear insertion, binary insertion, shellsort, bubble exchange, shakersort, quick sort, straight selection, and tree selection. Provides challenges for the reader and the student to program these efficiently. (JM)

  8. Chip-based droplet sorting

    Energy Technology Data Exchange (ETDEWEB)

    Beer, Neil Reginald; Lee, Abraham; Hatch, Andrew

    2017-11-21

    A non-contact system for sorting monodisperse water-in-oil emulsion droplets in a microfluidic device based on the droplet's contents and their interaction with an applied electromagnetic field or by identification and sorting.

  9. Polarization ray tracing in anisotropic optically active media. I. Algorithms

    International Nuclear Information System (INIS)

    McClain, S.C.; Hillman, L.W.; Chipman, R.A.

    1993-01-01

    Procedures for performing polarization ray tracing through birefringent media are presented in a form compatible with the standard methods of geometrical ray tracing. The birefringent materials treated include the following: anisotropic optically active materials such as quartz, non-optically active uniaxial materials such as calcite, and isotropic optically active materials such as mercury sulfide and organic liquids. Refraction and reflection algorithms are presented that compute both ray directions and wave directions. Methods for computing polarization modes, refractive indices, optical path lengths, and Fresnel transmission and reflection coefficients are also specified. A numerical example of these algorithms is given for analyzing the field of view of a quartz rotator. 37 refs., 3 figs

  10. Development of a fluorescence-activated cell sorting method coupled with whole genome amplification to analyze minority and trace Dehalococcoides genomes in microbial communities.

    Science.gov (United States)

    Lee, Patrick K H; Men, Yujie; Wang, Shanquan; He, Jianzhong; Alvarez-Cohen, Lisa

    2015-02-03

    Dehalococcoides mccartyi are functionally important bacteria that catalyze the reductive dechlorination of chlorinated ethenes. However, these anaerobic bacteria are fastidious to isolate, making downstream genomic characterization challenging. In order to facilitate genomic analysis, a fluorescence-activated cell sorting (FACS) method was developed in this study to separate D. mccartyi cells from a microbial community, and the DNA of the isolated cells was processed by whole genome amplification (WGA) and hybridized onto a D. mccartyi microarray for comparative genomics against four sequenced strains. First, FACS was successfully applied to a D. mccartyi isolate as positive control, and then microarray results verified that WGA from 10(6) cells or ∼1 ng of genomic DNA yielded high-quality coverage detecting nearly all genes across the genome. As expected, some inter- and intrasample variability in WGA was observed, but these biases were minimized by performing multiple parallel amplifications. Subsequent application of the FACS and WGA protocols to two enrichment cultures containing ∼10% and ∼1% D. mccartyi cells successfully enabled genomic analysis. As proof of concept, this study demonstrates that coupling FACS with WGA and microarrays is a promising tool to expedite genomic characterization of target strains in environmental communities where the relative concentrations are low.

  11. The catalystic asymmetric synthesis of optically active epoxy ketones

    NARCIS (Netherlands)

    Marsman, Bertha Gerda

    1981-01-01

    In this thesis the use of catalytic asymmetric synthesis to prepare optically active epoxy ketones is described. This means that the auxiliary chirality, necessary to obtain an optically active product, is added in a catalytic quantity . In principle this is a very efficient way to make opticlly

  12. Active Learning Environment with Lenses in Geometric Optics

    Science.gov (United States)

    Tural, Güner

    2015-01-01

    Geometric optics is one of the difficult topics for students within physics discipline. Students learn better via student-centered active learning environments than the teacher-centered learning environments. So this study aimed to present a guide for middle school teachers to teach lenses in geometric optics via active learning environment…

  13. NASA's current activities in free space optical communications

    Science.gov (United States)

    Edwards, Bernard L.

    2017-11-01

    NASA and other space agencies around the world are currently developing free space optical communication systems for both space-to-ground links and space-to-space links. This paper provides an overview of NASA's current activities in free space optical communications with a focus on Near Earth applications. Activities to be discussed include the Lunar Laser Communication Demonstration, the Laser Communications Relay Demonstration, and the commercialization of the underlying technology. The paper will also briefly discuss ongoing efforts and studies for Deep Space optical communications. Finally the paper will discuss the development of international optical communication standards within the Consultative Committee for Space Data Systems.

  14. Protein Sorting Prediction

    DEFF Research Database (Denmark)

    Nielsen, Henrik

    2017-01-01

    and drawbacks of each of these approaches is described through many examples of methods that predict secretion, integration into membranes, or subcellular locations in general. The aim of this chapter is to provide a user-level introduction to the field with a minimum of computational theory.......Many computational methods are available for predicting protein sorting in bacteria. When comparing them, it is important to know that they can be grouped into three fundamentally different approaches: signal-based, global-property-based and homology-based prediction. In this chapter, the strengths...

  15. Det sorte USA

    DEFF Research Database (Denmark)

    Brøndal, Jørn

    Bogen gennemgår det sorte USAs historie fra 1776 til 2016, idet grundtemaet er spændingsforholdet mellem USAs grundlæggelsesidealer og den racemæssige praksis, et spændingsforhold som Gunnar Myrdal kaldte "det amerikanske dilemma." Bogen, der er opbygget som politisk, social og racemæssig histori......, er opdelt i 13 kapitler og består af fire dele: Første del: Slaveriet; anden del: Jim Crow; tredje del. King-årene; fjerde del: Frem mod Obama....

  16. Gender Differences in Sorting

    DEFF Research Database (Denmark)

    Merlino, Luca Paolo; Parrotta, Pierpaolo; Pozzoli, Dario

    and causing the most productive female workers to seek better jobs in more female-friendly firms in which they can pursue small career advancements. Nonetheless, gender differences in promotion persist and are found to be similar in all firms when we focus on large career advancements. These results provide......In this paper, we investigate the sorting of workers in firms to understand gender gaps in labor market outcomes. Using Danish employer-employee matched data, we fiend strong evidence of glass ceilings in certain firms, especially after motherhood, preventing women from climbing the career ladder...

  17. Reduction of Aflatoxins in Apricot Kernels by Electronic and Manual Color Sorting

    OpenAIRE

    Zivoli, Rosanna; Gambacorta, Lucia; Piemontese, Luca; Solfrizzo, Michele

    2016-01-01

    The efficacy of color sorting on reducing aflatoxin levels in shelled apricot kernels was assessed. Naturally-contaminated kernels were submitted to an electronic optical sorter or blanched, peeled, and manually sorted to visually identify and sort discolored kernels (dark and spotted) from healthy ones. The samples obtained from the two sorting approaches were ground, homogenized, and analysed by HPLC-FLD for their aflatoxin content. A mass balance approach was used to measure the distributi...

  18. Selective sorting of waste

    CERN Multimedia

    2007-01-01

    Not much effort needed, just willpower In order to keep the cost of disposing of waste materials as low as possible, CERN provides two types of recipient at the entrance to each building: a green plastic one for paper/cardboard and a metal one for general refuse. For some time now we have noticed, to our great regret, a growing negligence as far as selective sorting is concerned, with, for example, the green recipients being filled with a mixture of cardboard boxes full of polystyrene or protective wrappers, plastic bottles, empty yogurts pots, etc. …We have been able to ascertain, after careful checking, that this haphazard mixing of waste cannot be attributed to the cleaning staff but rather to members of the personnel who unscrupulously throw away their rubbish in a completely random manner. Non-sorted waste entails heavy costs for CERN. For information, once a non-compliant item is found in a green recipient, the entire contents are sent off for incineration rather than recycling… We are all concerned...

  19. THE NATURE OF OPTICALLY DULL ACTIVE GALACTIC NUCLEI IN COSMOS

    International Nuclear Information System (INIS)

    Trump, Jonathan R.; Impey, Chris D.; Gabor, Jared M.; Taniguchi, Yoshi; Nagao, Tohru; Shioya, Yasuhiro; Brusa, Marcella; Civano, Francesca; Elvis, Martin; Kelly, Brandon C.; Huchra, John P.; Jahnke, Knud; Koekemoer, Anton M.; Salvato, Mara; Capak, Peter; Scoville, Nick Z.; Kartaltepe, Jeyhan S.; Lanzuisi, Giorgio; McCarthy, Patrick J.; Maineri, Vincenzo

    2009-01-01

    We present infrared, optical, and X-ray data of 48 X-ray bright, optically dull active galactic nuclei (AGNs) in the COSMOS field. These objects exhibit the X-ray luminosity of an AGN but lack broad and narrow emission lines in their optical spectrum. We show that despite the lack of optical emission lines, most of these optically dull AGNs are not well described by a typical passive red galaxy spectrum: instead they exhibit weak but significant blue emission like an unobscured AGN. Photometric observations over several years additionally show significant variability in the blue emission of four optically dull AGNs. The nature of the blue and infrared emission suggest that the optically inactive appearance of these AGNs cannot be caused by obscuration intrinsic to the AGNs. Instead, up to ∼70% of optically dull AGNs are diluted by their hosts, with bright or simply edge-on hosts lying preferentially within the spectroscopic aperture. The remaining ∼30% of optically dull AGNs have anomalously high f X /f O ratios and are intrinsically weak, not obscured, in the optical. These optically dull AGNs are best described as a weakly accreting AGN with a truncated accretion disk from a radiatively inefficient accretion flow.

  20. A two-channel detection method for autofluorescence correction and efficient on-bead screening of one-bead one-compound combinatorial libraries using the COPAS fluorescence activated bead sorting system

    International Nuclear Information System (INIS)

    Hintersteiner, Martin; Auer, Manfred

    2013-01-01

    One-bead one-compound combinatorial library beads exhibit varying levels of autofluorescence after solid phase combinatorial synthesis. Very often this causes significant problems for automated on-bead screening using TentaGel beads and fluorescently labeled target proteins. Herein, we present a method to overcome this limitation when fluorescence activated bead sorting is used as the screening method. We have equipped the COPAS bead sorting instrument with a high-speed profiling unit and developed a spectral autofluorescence correction method. The correction method is based on a simple algebraic operation using the fluorescence data from two detection channels and is applied on-the-fly in order to reliably identify hit beads by COPAS bead sorting. Our method provides a practical tool for the fast and efficient isolation of hit beads from one-bead one-compound library screens using either fluorescently labeled target proteins or biotinylated target proteins. This method makes hit bead identification easier and more reliable. It reduces false positives and eliminates the need for time-consuming pre-sorting of library beads in order to remove autofluorescent beads. (technical note)

  1. Simple sorting algorithm test based on CUDA

    OpenAIRE

    Meng, Hongyu; Guo, Fangjin

    2015-01-01

    With the development of computing technology, CUDA has become a very important tool. In computer programming, sorting algorithm is widely used. There are many simple sorting algorithms such as enumeration sort, bubble sort and merge sort. In this paper, we test some simple sorting algorithm based on CUDA and draw some useful conclusions.

  2. Optically active Babinet planar metamaterial film for terahertz polarization manipulation

    DEFF Research Database (Denmark)

    Zalkovskij, Maksim; Malureanu, Radu; Kremers, C.

    2013-01-01

    A planar Babinet-inverted dimer metamaterial possessing strong optical activity is proposed and characterized. An original fabrication method to produce large area (up to several cm2) freely suspended flexible metallic membranes is implemented to fabricate the metamaterial. Its optical properties...

  3. Teleoperated robotic sorting system

    Science.gov (United States)

    Roos, Charles E.; Sommer, Edward J.; Parrish, Robert H.; Russell, James R.

    2000-01-01

    A method and apparatus are disclosed for classifying materials utilizing a computerized touch sensitive screen or other computerized pointing device for operator identification and electronic marking of spatial coordinates of materials to be extracted. An operator positioned at a computerized touch sensitive screen views electronic images of the mixture of materials to be sorted as they are conveyed past a sensor array which transmits sequences of images of the mixture either directly or through a computer to the touch sensitive display screen. The operator manually "touches" objects displayed on the screen to be extracted from the mixture thereby registering the spatial coordinates of the objects within the computer. The computer then tracks the registered objects as they are conveyed and directs automated devices including mechanical means such as air jets, robotic arms, or other mechanical diverters to extract the registered objects.

  4. Track data sort program

    International Nuclear Information System (INIS)

    Abramov, N.A.; Matveev, V.A.; Fedotov, O.P.

    1977-01-01

    The description is given of the MASKA program, based on the principle of sorting points array at surface due to their belonging to the topologically connected regions with boundaries of locked broken lines. The algorithm is realized on the ES-1010 computer for automatic image processing from the bubble chambers by scanning measuring projector. The methods are considered for constructing the above mentioned regions for all the images according to the base points measured on the semiautomatic measuring table. The MASKA program is written in the ASSEMBLER-2 language and equals 3.5K words of the main memory. The average processing time for 10000 points according to one mask is 1 sec

  5. Optically Activated Exciplex Shutter/Attenuator.

    Science.gov (United States)

    radiation of a certain wavelength to excite a bi-molecular exciplex solution. The exciplex solution reacts to a range of radiation wavelengths whereas...optical elements prevent passage of radiation below and above the operative range of an exciplex solution such as anthracene and diethylaniline.

  6. Active Micro structured Optical Arrays of Grazing Incidence Reflectors

    International Nuclear Information System (INIS)

    Willingale, R.; Feldman, Ch.; Michette, A.; Hart, D.; McFaul, Ch; Morrison, G.R.; Pfauntsch, S.; Powell, A.K.; Sahraei, Sh.; Shand, M.T.; Button, T.; Rodriguez-Sanmartin, D.; Zhang, D.; Dunare, C.; Parkes, W.; Stevenson, T.; Folkard, M.; Vojnovic, B.; Vojnovic, B.

    2011-01-01

    The UK Smart X-Ray Optics (SXO) programme is developing active/adaptive optics for terrestrial applications. One of the technologies proposed is micro structured optical arrays (MOAs), which focus X-rays using grazing incidence reflection through consecutive aligned arrays of microscopic channels. Although such arrays are similar in concept to poly capillary and microchannel plate optics, they can be bent and adjusted using piezoelectric actuators providing control over the focusing and inherent aberrations. Custom configurations can be designed, using ray tracing and finite element analysis, for applications from sub-keV to several-keV X-rays, and the channels of appropriate aspect ratios can be made using deep silicon etching. An exemplar application will be in the micro probing of biological cells and tissue samples using Ti Ka radiation (4.5?keV) in studies related to radiation-induced cancers. This paper discusses the optical design, modelling, and manufacture of such optics

  7. Optical Switching for Dynamic Distribution of Wireless-Over-Fiber Signals in Active Optical Networks

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Rodes, Guillermo; Tafur Monroy, Idelfonso

    2012-01-01

    In this paper, we report on an experimental validation of dynamic distribution of wireless-over-fiber by employing optical switching using semiconductor optical amplifiers; we also provide a channel distribution scheme and a generic topology for such an optical switch. The experiment consists...... of a four wavelength-division-multiplexed channel system operating on a WiMax frequency band and employing an orthogonal-frequency-division-multiplexing modulation at 625 Mbits/s per channel, transmission of the data over 20 km of optical fiber, and active switching in a 1 × 16 active optical switch....... The results show a negligible power penalty on each channel for both the best and the worst case in terms of inter-channel crosstalk. The presented system is highly scalable both in terms of port count and throughput, a desirable feature in highly branched access networks, and is modulation- and frequency...

  8. Algorithm Sorts Groups Of Data

    Science.gov (United States)

    Evans, J. D.

    1987-01-01

    For efficient sorting, algorithm finds set containing minimum or maximum most significant data. Sets of data sorted as desired. Sorting process simplified by reduction of each multielement set of data to single representative number. First, each set of data expressed as polynomial with suitably chosen base, using elements of set as coefficients. Most significant element placed in term containing largest exponent. Base selected by examining range in value of data elements. Resulting series summed to yield single representative number. Numbers easily sorted, and each such number converted back to original set of data by successive division. Program written in BASIC.

  9. Dextran solution optical activity in Tb (III) ion presence

    International Nuclear Information System (INIS)

    Vasconcellos, Sandra S.; Rodrigues, J.F.; Faljoni-Alario, A.

    1984-01-01

    Optical activity studies of aqueous solutions of dextrana in presence of Tb (III) or without it shows the complex with the hidroxyl groups of C 2 and C 3 of monomeric unit participation is formed. (L.M.J.) [pt

  10. Synthesis and characterization of new optically active poly(amide ...

    African Journals Online (AJOL)

    Synthesis and characterization of new optically active poly(amide-imide)s based on N -trimellitimido- ... Bulletin of the Chemical Society of Ethiopia ... (DMAc), dimethyl sulfoxide (DMSO) and N-methyl-2-pyrrolidone (NMP) at room temperature.

  11. Ultrafast chiroptical spectroscopy: Monitoring optical activity in quick time

    Directory of Open Access Journals (Sweden)

    Hanju Rhee

    2011-12-01

    Full Text Available Optical activity spectroscopy provides rich structural information of biologically important molecules in condensed phases. However, a few intrinsic problems of conventional method based on electric field intensity measurement scheme prohibited its extension to time domain technique. We have recently developed new types of optical activity spectroscopic methods capable of measuring chiroptical signals with femtosecond pulses. It is believed that these novel approaches will be applied to a variety of ultrafast chiroptical studies.

  12. Microtechnology for cell manipulation and sorting

    CERN Document Server

    Tseng, Peter; Carlo, Dino

    2017-01-01

    This book delves into the recent developments in the microscale and microfluidic technologies that allow manipulation at the single and cell aggregate level. Expert authors review the dominant mechanisms that manipulate and sort biological structures, making this a state-of-the-art overview of conventional cell sorting techniques, the principles of microfluidics, and of microfluidic devices. All chapters highlight the benefits and drawbacks of each technique they discuss, which include magnetic, electrical, optical, acoustic, gravity/sedimentation, inertial, deformability, and aqueous two-phase systems as the dominant mechanisms utilized by microfluidic devices to handle biological samples. Each chapter explains the physics of the mechanism at work, and reviews common geometries and devices to help readers decide the type of style of device required for various applications. This book is appropriate for graduate-level biomedical engineering and analytical chemistry students, as well as engineers and scientist...

  13. German activities in optical space instrumentation

    Science.gov (United States)

    Hartmann, G.

    2018-04-01

    In the years of space exploration since the mid-sixties, a wide experience in optical space instrumentation has developed in Germany. This experience ranges from large telescopes in the 1 m and larger category with the accompanying focal plane detectors and spectrometers for all regimes of the electromagnetic spectrum (infrared, visible, ultraviolet, x-rays), to miniature cameras for cometary and planetary explorations. The technologies originally developed for space science. are now also utilized in the fields of earth observation and even optical telecommunication. The presentation will cover all these areas, with examples for specific technological or scientific highlights. Special emphasis will be given to the current state-of-the-art instrumentation technologies in scientific institutions and industry, and to the future perspective in approved and planned projects.

  14. Raman optical activity of proteins and glycoproteins

    International Nuclear Information System (INIS)

    Smyth, E.

    2000-03-01

    Raman optical activity (ROA), measured in this project as a small difference in the intensity of Raman scattering from chiral molecules in right- and left-circularly polarised incident laser light, offers the potential to provide more information about the structure of biological molecules in aqueous solution than conventional spectroscopic techniques. Chapter one contains a general discussion of the relative merits of different spectroscopic techniques for structure determination of biomolecules, as well as a brief introduction to ROA. In Chapter two a theoretical analysis of ROA is developed, which extends the discussion in chapter one. The spectrometer setup and sample preparation is then discussed in chapter three. Instrument and sample conditions are monitored to ensure that the best results are obtained. As with any experimental project problems occur, which may result in a degradation of the spectra obtained. The cause of these problems was explored and remedied whenever possible. Chapter four introduces a brief account of protein, glycoprotein and carbohydrate structure and function, with a particular emphasis on the structure of proteins. In the remaining chapters experimental ROA results on proteins and glycoproteins, with some carbohydrate samples, from a wide range of sources are examined. For example, in chapter five some β-sheet proteins are examined. Structural features in these proteins are examined in the extended amide III region of their ROA spectra, revealing that ROA is sensitive to the rigidity or flexibility inherent in proteins. Chapter six concentrates on a group of proteins (usually glycoproteins) known as the serine proteinase inhibitors (serpins). Medically, the serpins are one of the most important groups of proteins of current interest, with wide-ranging implications in conditions such as Down's syndrome, Alzheimer's disease, and emphysema with associated cirrhosis of the liver. With favourable samples and conditions ROA may offer the

  15. Resonance Raman Optical Activity and Surface Enhanced Resonance Raman Optical Activity analysis of Cytochrome C

    DEFF Research Database (Denmark)

    Johannessen, Christian; Abdali, Salim; White, Peter C.

    2007-01-01

    High quality Resonance Raman (RR) and resonance Raman Optical Activity (ROA) spectra of cytochrome c were obtained in order to perform full assignment of spectral features of the resonance ROA spectrum. The resonance ROA spectrum of cytochrome c revealed a distinct spectral signature pattern due...... to resonance enhanced skeletal porphyrin vibrations, more pronounced than any contribution from the protein back-bone. Combining the intrinsic resonance enhancement of cytochrome c with surface plasmon enhancement by colloidal silver particles, the Surface Enhanced Resonance Raman Scattering (SERRS) and Chiral...... Enhanced Raman Spectroscopy (ChERS) spectra of the protein were successfully obtained at very low concentration (as low as 1 µM). The assignment of spectral features was based on the information obtained from the RR and resonance ROA spectra. Excellent agreement between RR and SERRS spectra is reported...

  16. Perbandingan Bubble Sort dengan Insertion Sort pada Bahasa Pemrograman C dan Fortran

    OpenAIRE

    Reina, Reina; Gautama, Josef Bernadi

    2013-01-01

    Sorting is a basic algorithm studied by students of computer science major. Sorting algorithm is the basis of other algorithms such as searching algorithm, pattern matching algorithm. Bubble sort is a popular basic sorting algorithm due to its easiness to be implemented. Besides bubble sort, there is insertion sort. It is lesspopular than bubble sort because it has more difficult algorithm. This paper discusses about process time between insertion sort and bubble sort with two kinds of data. ...

  17. Comparative analysis of circulating endothelial progenitor cells in age-related macular degeneration patients using automated rare cell analysis (ARCA and fluorescence activated cell sorting (FACS.

    Directory of Open Access Journals (Sweden)

    Emil Anthony T Say

    Full Text Available BACKGROUND: Patients with age-related macular degeneration (ARMD begin with non-neovascular (NNV phenotypes usually associated with good vision. Approximately 20% of NNV-ARMD patients will convert to vision debilitating neovascular (NV ARMD, but precise timing of this event is unknown. Developing a clinical test predicting impending conversion to NV-ARMD is necessary to prevent vision loss. Endothelial progenitor cells (EPCs, defined as CD34(+VEGR2(+ using traditional fluorescence activated cell sorting (FACS, are rare cell populations known to be elevated in patients with NV-ARMD compared to NNV-ARMD. FACS has high inter-observer variability and subjectivity when measuring rare cell populations precluding development into a diagnostic test. We hypothesized that automated rare cell analysis (ARCA, a validated and FDA-approved technology for reproducible rare cell identification, can enumerate EPCs in ARMD patients more reliably. This pilot study serves as the first step in developing methods for reproducibly predicting ARMD phenotype conversion. METHODS: We obtained peripheral venous blood samples in 23 subjects with NNV-ARMD or treatment naïve NV-ARMD. Strict criteria were used to exclude subjects with known angiogenic diseases to minimize confounding results. Blood samples were analyzed in masked fashion in two separate laboratories. EPCs were independently enumerated using ARCA and FACS within 24 hours of blood sample collection, and p<0.2 was considered indicative of a trend for this proof of concept study, while statistical significance was established at 0.05. RESULTS: We measured levels of CD34(+VEGFR2(+ EPCs suggestive of a trend with higher values in patients with NV compared to NNV-ARMD (p = 0.17 using ARCA. Interestingly, CD34(+VEGR2(+ EPC analysis using FACS did not produce similar results (p = 0.94. CONCLUSIONS: CD34(+VEGR2(+ may have predictive value for EPC enumeration in future ARCA studies. EPC measurements in a small sample

  18. Comparative analysis of circulating endothelial progenitor cells in age-related macular degeneration patients using automated rare cell analysis (ARCA) and fluorescence activated cell sorting (FACS).

    Science.gov (United States)

    Say, Emil Anthony T; Melamud, Alex; Esserman, Denise Ann; Povsic, Thomas J; Chavala, Sai H

    2013-01-01

    Patients with age-related macular degeneration (ARMD) begin with non-neovascular (NNV) phenotypes usually associated with good vision. Approximately 20% of NNV-ARMD patients will convert to vision debilitating neovascular (NV) ARMD, but precise timing of this event is unknown. Developing a clinical test predicting impending conversion to NV-ARMD is necessary to prevent vision loss. Endothelial progenitor cells (EPCs), defined as CD34(+)VEGR2(+) using traditional fluorescence activated cell sorting (FACS), are rare cell populations known to be elevated in patients with NV-ARMD compared to NNV-ARMD. FACS has high inter-observer variability and subjectivity when measuring rare cell populations precluding development into a diagnostic test. We hypothesized that automated rare cell analysis (ARCA), a validated and FDA-approved technology for reproducible rare cell identification, can enumerate EPCs in ARMD patients more reliably. This pilot study serves as the first step in developing methods for reproducibly predicting ARMD phenotype conversion. We obtained peripheral venous blood samples in 23 subjects with NNV-ARMD or treatment naïve NV-ARMD. Strict criteria were used to exclude subjects with known angiogenic diseases to minimize confounding results. Blood samples were analyzed in masked fashion in two separate laboratories. EPCs were independently enumerated using ARCA and FACS within 24 hours of blood sample collection, and ptrend for this proof of concept study, while statistical significance was established at 0.05. We measured levels of CD34(+)VEGFR2(+) EPCs suggestive of a trend with higher values in patients with NV compared to NNV-ARMD (p = 0.17) using ARCA. Interestingly, CD34(+)VEGR2(+) EPC analysis using FACS did not produce similar results (p = 0.94). CD34(+)VEGR2(+) may have predictive value for EPC enumeration in future ARCA studies. EPC measurements in a small sample size were suggestive of a trend in ARMD using ARCA but not FACS. ARCA could be a

  19. Lipid vesicle-mediated affinity chromatography using magnetic activated cell sorting (LIMACS): a novel method to analyze protein-lipid interaction.

    Science.gov (United States)

    Bieberich, Erhard

    2011-04-26

    The analysis of lipid protein interaction is difficult because lipids are embedded in cell membranes and therefore, inaccessible to most purification procedures. As an alternative, lipids can be coated on flat surfaces as used for lipid ELISA and Plasmon resonance spectroscopy. However, surface coating lipids do not form microdomain structures, which may be important for the lipid binding properties. Further, these methods do not allow for the purification of larger amounts of proteins binding to their target lipids. To overcome these limitations of testing lipid protein interaction and to purify lipid binding proteins we developed a novel method termed lipid vesicle-mediated affinity chromatography using magnetic-activated cell sorting (LIMACS). In this method, lipid vesicles are prepared with the target lipid and phosphatidylserine as the anchor lipid for Annexin V MACS. Phosphatidylserine is a ubiquitous cell membrane phospholipid that shows high affinity to the protein Annexin V. Using magnetic beads conjugated to Annexin V the phosphatidylserine-containing lipid vesicles will bind to the magnetic beads. When the lipid vesicles are incubated with a cell lysate the protein binding to the target lipid will also be bound to the beads and can be co-purified using MACS. This method can also be used to test if recombinant proteins reconstitute a protein complex binding to the target lipid. We have used this method to show the interaction of atypical PKC (aPKC) with the sphingolipid ceramide and to co-purify prostate apoptosis response 4 (PAR-4), a protein binding to ceramide-associated aPKC. We have also used this method for the reconstitution of a ceramide-associated complex of recombinant aPKC with the cell polarity-related proteins Par6 and Cdc42. Since lipid vesicles can be prepared with a variety of sphingo- or phospholipids, LIMACS offers a versatile test for lipid-protein interaction in a lipid environment that resembles closely that of the cell membrane

  20. Modeling and analysis of laser active interference optical path

    Science.gov (United States)

    Shan, Cong-miao; Sun, Hua-yan; Zhao, Yan-zhong; Chen, Jian-biao; Ren, Jian-ying

    2017-10-01

    By using the geometrical optics and physical optics method, the models of wedge plate interference optical path, Michelson interferometer and Mach Zehnder interferometer thus three different active interference pattern are built. The optical path difference (OPD) launched by different interference patterns, fringe spacing and contrast expression have been derived. The results show that far field interference peak intensity of the wedge plate interference is small, so the detection distance is limited, Michelson interferometer with low contrast affects the performance of detection system, Mach Zehnder interferometer has greater advantages in peak intensity, the variable range of interference fringe spacing and contrast ratio. The results of this study are useful for the theoretical research and practical application of laser active interference detection.

  1. Near-simultaneous optical and infrared spectrophotometry of active galaxies

    International Nuclear Information System (INIS)

    Yates, M.G.; Garden, R.P.

    1989-01-01

    We present optical and infrared spectrophotometry for a sample of eight optically bright quasars, and the broad-line radio galaxy (BLRG) 3C 120. The optical and infrared spectrophotometry is separated by only five weeks, thus we have been able to minimize uncertainties due to variations in the objects. We compare our observed Paα/Hα and Hα/Hβ ratios with a large number of current photoionization models. We find that none of these models are able to reproduce our observed values of Paα/Hα in any of the active galaxies except the quasars 3C 273 and 0736+017. (author)

  2. Polarized electrons and the origin of optical activity

    International Nuclear Information System (INIS)

    Bonner, W.A.; Dort, M.A. Van; Yearian, M.R.; Zeman, H.D.; Li, G.C.; Stanford Univ., Calif.

    1976-01-01

    The history of experiments bearing on the origin of optical acitivity in nature by parity non-conservation during the β-decay of radioactive isotopes is briefly reviewed. Following this, we present a more detailed description of our recent published and unpublished data and calculations regarding the generation of optical activity in DL-leucine by means of artificially produced longitudinally polarized electrons from a linear accelerator

  3. Scalable Active Optical Access Network Using Variable High-Speed PLZT Optical Switch/Splitter

    Science.gov (United States)

    Ashizawa, Kunitaka; Sato, Takehiro; Tokuhashi, Kazumasa; Ishii, Daisuke; Okamoto, Satoru; Yamanaka, Naoaki; Oki, Eiji

    This paper proposes a scalable active optical access network using high-speed Plumbum Lanthanum Zirconate Titanate (PLZT) optical switch/splitter. The Active Optical Network, called ActiON, using PLZT switching technology has been presented to increase the number of subscribers and the maximum transmission distance, compared to the Passive Optical Network (PON). ActiON supports the multicast slot allocation realized by running the PLZT switch elements in the splitter mode, which forces the switch to behave as an optical splitter. However, the previous ActiON creates a tradeoff between the network scalability and the power loss experienced by the optical signal to each user. It does not use the optical power efficiently because the optical power is simply divided into 0.5 to 0.5 without considering transmission distance from OLT to each ONU. The proposed network adopts PLZT switch elements in the variable splitter mode, which controls the split ratio of the optical power considering the transmission distance from OLT to each ONU, in addition to PLZT switch elements in existing two modes, the switching mode and the splitter mode. The proposed network introduces the flexible multicast slot allocation according to the transmission distance from OLT to each user and the number of required users using three modes, while keeping the advantages of ActiON, which are to support scalable and secure access services. Numerical results show that the proposed network dramatically reduces the required number of slots and supports high bandwidth efficiency services and extends the coverage of access network, compared to the previous ActiON, and the required computation time for selecting multicast users is less than 30msec, which is acceptable for on-demand broadcast services.

  4. Active material, optical mode and cavity impact on nanoscale electro-optic modulation performance

    Science.gov (United States)

    Amin, Rubab; Suer, Can; Ma, Zhizhen; Sarpkaya, Ibrahim; Khurgin, Jacob B.; Agarwal, Ritesh; Sorger, Volker J.

    2017-10-01

    Electro-optic modulation is a key function in optical data communication and possible future optical compute engines. The performance of modulators intricately depends on the interaction between the actively modulated material and the propagating waveguide mode. While a variety of high-performance modulators have been demonstrated, no comprehensive picture of what factors are most responsible for high performance has emerged so far. Here we report the first systematic and comprehensive analytical and computational investigation for high-performance compact on-chip electro-optic modulators by considering emerging active materials, model considerations and cavity feedback at the nanoscale. We discover that the delicate interplay between the material characteristics and the optical mode properties plays a key role in defining the modulator performance. Based on physical tradeoffs between index modulation, loss, optical confinement factors and slow-light effects, we find that there exist combinations of bias, material and optical mode that yield efficient phase or amplitude modulation with acceptable insertion loss. Furthermore, we show how material properties in the epsilon near zero regime enable reduction of length by as much as by 15 times. Lastly, we introduce and apply a cavity-based electro-optic modulator figure of merit, Δλ/Δα, relating obtainable resonance tuning via phase shifting relative to the incurred losses due to the fundamental Kramers-Kronig relations suggesting optimized device operating regions with optimized modulation-to-loss tradeoffs. This work paves the way for a holistic design rule of electro-optic modulators for high-density on-chip integration.

  5. Active Learning Strategies for Introductory Light and Optics

    Science.gov (United States)

    Sokoloff, David R.

    2016-01-01

    There is considerable evidence that traditional approaches are ineffective in teaching physics concepts, including light and optics concepts. A major focus of the work of the Activity Based Physics Group has been on the development of active learning curricula like RealTime Physics (RTP) labs and Interactive Lecture Demonstrations (ILDs). Among…

  6. Low-frequency active surface plasmon optics on semiconductors

    NARCIS (Netherlands)

    Gómez Rivas, J.; Kuttge, M.; Kurz, H.; Haring Bolivar, P.; Sánchez-Gil, J.A.

    2006-01-01

    A major challenge in the development of surface plasmon optics or plasmonics is the active control of the propagation of surface plasmon polaritons (SPPs). Here, we demonstrate the feasibility of low-frequency active plasmonics using semiconductors. We show experimentally that the Bragg scattering

  7. Active x-ray optics for high resolution space telescopes

    Science.gov (United States)

    Doel, Peter; Atkins, Carolyn; Brooks, D.; Feldman, Charlotte; Willingale, Richard; Button, Tim; Rodriguez Sanmartin, Daniel; Meggs, Carl; James, Ady; Willis, Graham; Smith, Andy

    2017-11-01

    The Smart X-ray Optics (SXO) Basic Technology project started in April 2006 and will end in October 2010. The aim is to develop new technologies in the field of X-ray focusing, in particular the application of active and adaptive optics. While very major advances have been made in active/adaptive astronomical optics for visible light, little was previously achieved for X-ray optics where the technological challenges differ because of the much shorter wavelengths involved. The field of X-ray astronomy has been characterized by the development and launch of ever larger observatories with the culmination in the European Space Agency's XMM-Newton and NASA's Chandra missions which are currently operational. XMM-Newton uses a multi-nested structure to provide modest angular resolution ( 10 arcsec) but large effective area, while Chandra sacrifices effective area to achieve the optical stability necessary to provide sub-arc second resolution. Currently the European Space Agency (ESA) is engaged in studies of the next generation of X-ray space observatories, with the aim of producing telescopes with increased sensitivity and resolution. To achieve these aims several telescopes have been proposed, for example ESA and NASA's combined International X-ray Observatory (IXO), aimed at spectroscopy, and NASA's Generation-X. In the field of X-ray astronomy sub 0.2 arcsecond resolution with high efficiency would be very exciting. Such resolution is unlikely to be achieved by anything other than an active system. The benefits of a such a high resolution would be important for a range of astrophysics subjects, for example the potential angular resolution offered by active X-ray optics could provide unprecedented structural imaging detail of the Solar Wind bowshock interaction of comets, planets and similar objects and auroral phenomena throughout the Solar system using an observing platform in low Earth orbit. A major aim of the SXO project was to investigate the production of thin

  8. Fast incorporation of optical flow into active polygons.

    Science.gov (United States)

    Unal, Gozde; Krim, Hamid; Yezzi, Anthony

    2005-06-01

    In this paper, we first reconsider, in a different light, the addition of a prediction step to active contour-based visual tracking using an optical flow and clarify the local computation of the latter along the boundaries of continuous active contours with appropriate regularizers. We subsequently detail our contribution of computing an optical flow-based prediction step directly from the parameters of an active polygon, and of exploiting it in object tracking. This is in contrast to an explicitly separate computation of the optical flow and its ad hoc application. It also provides an inherent regularization effect resulting from integrating measurements along polygon edges. As a result, we completely avoid the need of adding ad hoc regularizing terms to the optical flow computations, and the inevitably arbitrary associated weighting parameters. This direct integration of optical flow into the active polygon framework distinguishes this technique from most previous contour-based approaches, where regularization terms are theoretically, as well as practically, essential. The greater robustness and speed due to a reduced number of parameters of this technique are additional and appealing features.

  9. Active polarization imaging system based on optical heterodyne balanced receiver

    Science.gov (United States)

    Xu, Qian; Sun, Jianfeng; Lu, Zhiyong; Zhou, Yu; Luan, Zhu; Hou, Peipei; Liu, liren

    2017-08-01

    Active polarization imaging technology has recently become the hot research field all over the world, which has great potential application value in the military and civil area. By introducing active light source, the Mueller matrix of the target can be calculated according to the incident light and the emitted or reflected light. Compared with conventional direct detection technology, optical heterodyne detection technology have higher receiving sensitivities, which can obtain the whole amplitude, frequency and phase information of the signal light. In this paper, an active polarization imaging system will be designed. Based on optical heterodyne balanced receiver, the system can acquire the horizontal and vertical polarization of reflected optical field simultaneously, which contain the polarization characteristic of the target. Besides, signal to noise ratio and imaging distance can be greatly improved.

  10. Major proteins in normal human lymphocyte subpopulations separated by fluorescence-activated cell sorting and analyzed by two-dimensional gel electrophoresis

    DEFF Research Database (Denmark)

    Madsen, P S; Hokland, M; Ellegaard, J

    1988-01-01

    markers were observed in all cell types. All the putative protein markers have been identified in the protein database of human peripheral blood mononuclear cells (PBMCs) (see accompanying article by Celis et al.). Comparison of the overall patterns of protein synthesis of the unsorted PBMCs with those...... of the four subpopulations showed that the synthesis of some major PBMC proteins decreased substantially in the sorted subsets. These proteins are most likely not of monocyte origin, as these cells constituted only about 15% of the total PBMCs. Also, the inhibition does not seem to be due to the addition...

  11. FTTA System Demo Using Optical Fiber-Coupled Active Antennas

    Directory of Open Access Journals (Sweden)

    Niels Neumann

    2014-08-01

    Full Text Available The convergence of optical and wireless systems such as Radio-over-Fiber (RoF networks is the key to coping with the increasing bandwidth demands due to the increasing popularity of video and other high data rate applications. A high level of integration of optical technologies enables simple base stations with a fiber-to-the-antenna (FTTA approach. In this paper, we present a complete full-duplex RoF–FTTA system consisting of integrated active fiber-coupled optical receiving and transmitting antennas that are directly connected to a standard single mode fiber optical link. Data rates up to 1 Gbit/s could be shown without advanced modulation formats on a 1.5 GHz carrier frequency. The antennas as well as the whole system are explained and the results of the system experiments are discussed.

  12. Activity of the C-terminal-dependent vacuolar sorting signal of horseradish peroxidase C1a is enhanced by its secondary structure.

    Science.gov (United States)

    Matsui, Takeshi; Tabayashi, Ayako; Iwano, Megumi; Shinmyo, Atsuhiko; Kato, Ko; Nakayama, Hideki

    2011-02-01

    Plant class III peroxidase (PRX) catalyzes the oxidation and oxidative polymerization of a variety of phenolic compounds while reducing hydrogen peroxide. PRX proteins are classified into apoplast type and vacuole type based on the absence or the presence of C-terminal propeptides, which probably function as vacuolar sorting signals (VSSs). In this study, in order to improve our understanding of vacuole-type PRX, we analyzed regulatory mechanisms of vacuolar sorting of a model vacuole-type PRX, the C1a isozyme of horseradish (Armoracia rusticana) (HRP C1a). Using cultured transgenic tobacco cells and protoplasts derived from horseradish leaves, we characterized HRP C1a's VSS, which is a 15 amino acid C-terminal propeptide (C15). We found that the C-terminal hexapeptide of C15 (C6), which is well conserved among vacuole-type PRX proteins, forms the core of the C-terminal-dependent VSS. We also found that the function of C6 is enhanced by the remaining N-terminal part of C15 which probably folds into an amphiphilic α-helix.

  13. A Novel and Simple Spike Sorting Implementation.

    Science.gov (United States)

    Petrantonakis, Panagiotis C; Poirazi, Panayiota

    2017-04-01

    Monitoring the activity of multiple, individual neurons that fire spikes in the vicinity of an electrode, namely perform a Spike Sorting (SS) procedure, comprises one of the most important tools for contemporary neuroscience in order to reverse-engineer the brain. As recording electrodes' technology rabidly evolves by integrating thousands of electrodes in a confined spatial setting, the algorithms that are used to monitor individual neurons from recorded signals have to become even more reliable and computationally efficient. In this work, we propose a novel framework of the SS approach in which a single-step processing of the raw (unfiltered) extracellular signal is sufficient for both the detection and sorting of the activity of individual neurons. Despite its simplicity, the proposed approach exhibits comparable performance with state-of-the-art approaches, especially for spike detection in noisy signals, and paves the way for a new family of SS algorithms with the potential for multi-recording, fast, on-chip implementations.

  14. Natural Selection Is a Sorting Process: What Does that Mean?

    Science.gov (United States)

    Price, Rebecca M.

    2013-01-01

    To learn why natural selection acts only on existing variation, students categorize processes as either creative or sorting. This activity helps students confront the misconception that adaptations evolve because species need them.

  15. Machine-vision based optofluidic cell sorting

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Bañas, Andrew

    the available light and creating 2D or 3D beam distributions aimed at the positions of the detected cells. Furthermore, the beam shaping freedom provided by GPC can allow optimizations in the beam’s propagation and its interaction with the laser catapulted and sorted cells....... machine vision1. This approach is gentler, less invasive and more economical compared to conventional FACS-systems. As cells are less responsive to plastic or glass objects commonly used in the optical manipulation literature2, and since laser safety would be an issue in clinical use, we develop efficient...... approaches in utilizing lasers and light modulation devices. The Generalized Phase Contrast (GPC) method3-9 that can be used for efficiently illuminating spatial light modulators10 or creating well-defined contiguous optical traps11 is supplemented by diffractive techniques capable of integrating...

  16. Optical Variability of Active Galactic Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Kozłowski, Szymon, E-mail: simkoz@astrouw.edu.pl [Astronomical Observatory, University of Warsaw, Warsaw (Poland)

    2017-09-21

    Variability studies of active galactic nuclei (AGNs) typically use either power spectral density (PSD) and structure function (SF) analyses or direct modeling of light curves with the damped random walk (DRW) and the continuous autoregressive moving average (CARMA) models. A fair fraction of research publications on the subject are flawed, and simply report incorrect results, because they lack a deep understanding of where these methods originate from and what their limitations are. For example, SF analyses typically lack or use a wrong noise subtraction procedure, leading to flat SFs. DRW, on the other hand, can only be used if the experiment length is sufficient, at least ten times the signal decorrelation time scale τ, and if the data show the power-law SF slope of γ ≡ 0.5.

  17. ALGORITHM FOR SORTING GROUPED DATA

    Science.gov (United States)

    Evans, J. D.

    1994-01-01

    It is often desirable to sort data sets in ascending or descending order. This becomes more difficult for grouped data, i.e., multiple sets of data, where each set of data involves several measurements or related elements. The sort becomes increasingly cumbersome when more than a few elements exist for each data set. In order to achieve an efficient sorting process, an algorithm has been devised in which the maximum most significant element is found, and then compared to each element in succession. The program was written to handle the daily temperature readings of the Voyager spacecraft, particularly those related to the special tracking requirements of Voyager 2. By reducing each data set to a single representative number, the sorting process becomes very easy. The first step in the process is to reduce the data set of width 'n' to a data set of width '1'. This is done by representing each data set by a polynomial of length 'n' based on the differences of the maximum and minimum elements. These single numbers are then sorted and converted back to obtain the original data sets. Required input data are the name of the data file to read and sort, and the starting and ending record numbers. The package includes a sample data file, containing 500 sets of data with 5 elements in each set. This program will perform a sort of the 500 data sets in 3 - 5 seconds on an IBM PC-AT with a hard disk; on a similarly equipped IBM PC-XT the time is under 10 seconds. This program is written in BASIC (specifically the Microsoft QuickBasic compiler) for interactive execution and has been implemented on the IBM PC computer series operating under PC-DOS with a central memory requirement of approximately 40K of 8 bit bytes. A hard disk is desirable for speed considerations, but is not required. This program was developed in 1986.

  18. Study towards diversity oriented synthesis of optically active ...

    Indian Academy of Sciences (India)

    oxidation procedures, all the reactions were carried out either in argon or nitrogen .... ring solution of alcohol 9a (300mg, 0.70mmol) dis- solved in 20 mL of DCM ..... In summary, diversity-oriented approach for the synthe- sis of optically active, ...

  19. Features of optical modeling in educational and scientific activity ...

    African Journals Online (AJOL)

    The article discusses the functionality of existing software for the modeling, analysis and optimization of lighting systems and optical elements, through which the stage of their design can be automated completely. The use of these programs is shown using the example of scientific work and the educational activity of ...

  20. Raman optical activity study on insulin amyloid- and prefibril intermediate

    Czech Academy of Sciences Publication Activity Database

    Yamamoto, Shigeki; Watarai, H.

    2012-01-01

    Roč. 24, č. 2 (2012), s. 97-103 ISSN 0899-0042 Institutional research plan: CEZ:AV0Z40550506 Keywords : raman optical activity * amyloid * fibril * intermediate * insulin Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.718, year: 2012

  1. Synthesis and characterization of new optically active poly(amide

    African Journals Online (AJOL)

    Preferred Customer

    Six new optically active poly(amide-imide)s (8a-f) were synthesized through the direct ... polyimides are widely used in the semiconductor and electronic packaging ... chiral polymers is of particular interest from the viewpoint of material science ...

  2. Optical storage media based on fluorite activated crystals

    International Nuclear Information System (INIS)

    Mokienko, I.Yu.; Poletimov, A.E.; Shcheulin, A.S.

    1991-01-01

    Earlier studied mechanisms of photo- and thermotransformations of defects in pure and activated additively coloured crystals with fluorite structure are considered to suggest several methods of reversible optical recording of images, characterized by high resistance to high-power laser radiation and mechanical deformation

  3. Active optics: off axis aspherics generation for high contrast imaging

    Science.gov (United States)

    Hugot, E.; Laslandes, M.; Ferrari, M.; Vives, S.; Moindrot, S.; El Hadi, K.; Dohlen, K.

    2017-11-01

    Active Optics methods, based on elasticity theory, allow the aspherisation of optical surfaces by stress polishing but also active aspherisation in situ. Researches in this field will impact the final performance and the final cost of any telescope or instrument. The stress polishing method is well suited for the superpolishing of aspheric components for astronomy. Its principle relies on spherical polishing with a full-sized tool of a warped substrate, which becomes aspherical once unwarped. The main advantage of this technique is the very high optical quality obtained either on form or on high spatial frequency errors. Furthermore, the roughness can be decreased down to a few angstroms, thanks the classical polishing with a large pitch tool, providing a substantial gain on the final scientific performance, for instance on the contrast on coronagraphic images, but also on the polishing time and cost. Stress polishing is based on elasticity theory, and requires an optimised deformation system able to provide the right aspherical form on the optical surface during polishing. The optical quality of the deformation is validated using extensive Finite Element Analysis, allowing an estimation of residuals and an optimisation of the warping harness. We describe here the work realised on stress polishing of toric mirrors for VLT-SPHERE and then our actual work on off axis aspherics (OAA) for the ASPIICS-Proba3 mission for solar coronagraphy. The ASPIICS optical design made by Vives et al is a three mirrors anastigmat including a concave off axis hyperboloid and a convex off axis parabola (OAP). We are developing a prototype in order to demonstrate the feasibility of this type of surface, using a multi-mode warping harness (Lemaitre et al). Furthermore, we present our work on variable OAP, meaning the possibility to adjust the shape of a simple OAP in situ with a minimal number of actuators, typically one actuator per optical mode (Focus, Coma and Astigmatism

  4. Layers in sorting practices: Sorting out patients with potential cancer

    DEFF Research Database (Denmark)

    Møller, Naja Holten; Bjørn, Pernille

    2011-01-01

    for a particular patient. Due to the limited resources within the Danish healthcare system, initiating cancer pathways for all patients with a remote suspicion of cancer would crash the system, as it would be impossible for healthcare professionals to commit to the prescribed schedules and times defined...... they show that sorting patients before initiating a standardized cancer pathway is not a simple process of deciding on a predefined category that will stipulate particular dates and times. Instead, these informal sorting mechanisms show that the process of sorting patients prior to diagnosis......In the last couple of years, widespread use of standardized cancer pathways has been seen across a range of countries, including Denmark, to improve prognosis of cancer patients. In Denmark, standardized cancer pathways take the form of guidelines prescribing well-defined sequences where steps...

  5. Optical Character Recognition Using Active Contour Segmentation

    Directory of Open Access Journals (Sweden)

    Nabeel Oudah

    2018-01-01

    Full Text Available Document analysis of images snapped by camera is a growing challenge. These photos are often poor-quality compound images, composed of various objects and text; this makes automatic analysis complicated. OCR is one of the image processing techniques which is used to perform automatic identification of texts. Existing image processing techniques need to manage many parameters in order to clearly recognize the text in such pictures. Segmentation is regarded one of these essential parameters. This paper discusses the accuracy of segmentation process and its effect over the recognition process. According to the proposed method, the images were firstly filtered using the wiener filter then the active contour algorithm could be applied in the segmentation process. The Tesseract OCR Engine was selected in order to evaluate the performance and identification accuracy of the proposed method. The results showed that a more accurate segmentation process shall lead to a more accurate recognition results. The rate of recognition accuracy was 0.95 for the proposed algorithm compared with 0.85 for the Tesseract OCR Engine.

  6. A Model Vision of Sorting System Application Using Robotic Manipulator

    Directory of Open Access Journals (Sweden)

    Maralo Sinaga

    2010-08-01

    Full Text Available Image processing in today’s world grabs massive attentions as it leads to possibilities of broaden application in many fields of high technology. The real challenge is how to improve existing sorting system in the Moduler Processing System (MPS laboratory which consists of four integrated stations of distribution, testing, processing and handling with a new image processing feature. Existing sorting method uses a set of inductive, capacitive and optical sensors do differentiate object color. This paper presents a mechatronics color sorting system solution with the application of image processing. Supported by OpenCV, image processing procedure senses the circular objects in an image captured in realtime by a webcam and then extracts color and position information out of it. This information is passed as a sequence of sorting commands to the manipulator (Mitsubishi Movemaster RV-M1 that does pick-and-place mechanism. Extensive testing proves that this color based object sorting system works 100% accurate under ideal condition in term of adequate illumination, circular objects’ shape and color. The circular objects tested for sorting are silver, red and black. For non-ideal condition, such as unspecified color the accuracy reduces to 80%.

  7. A Simple Deep Learning Method for Neuronal Spike Sorting

    Science.gov (United States)

    Yang, Kai; Wu, Haifeng; Zeng, Yu

    2017-10-01

    Spike sorting is one of key technique to understand brain activity. With the development of modern electrophysiology technology, some recent multi-electrode technologies have been able to record the activity of thousands of neuronal spikes simultaneously. The spike sorting in this case will increase the computational complexity of conventional sorting algorithms. In this paper, we will focus spike sorting on how to reduce the complexity, and introduce a deep learning algorithm, principal component analysis network (PCANet) to spike sorting. The introduced method starts from a conventional model and establish a Toeplitz matrix. Through the column vectors in the matrix, we trains a PCANet, where some eigenvalue vectors of spikes could be extracted. Finally, support vector machine (SVM) is used to sort spikes. In experiments, we choose two groups of simulated data from public databases availably and compare this introduced method with conventional methods. The results indicate that the introduced method indeed has lower complexity with the same sorting errors as the conventional methods.

  8. The USC-OSA-EPS section activities in optics

    Science.gov (United States)

    Aymerich, María.; Cambronero-López, Ferran; Aragón, Ángel L.; Delgado, Tamara; Blanco, Manuel; Gómez Varela, Ana I.; Gargallo, Ana; Williamson, Sandra; Amorín, Adán.; Sánchez-García, Ángel; Bao-Varela, Carmen; Flores-Arias, M. Teresa

    2017-08-01

    The USC-OSA Student Chapter and USC-EPS Young Minds Section is a group financed by The Optical Society (OSA) and the European Physical Society (EPS). It is formed by PhD and degree students from the Universidade de Santiago de Compostela (USC) and one supervisor of the Faculty of Physics. Its main goal is to promote and diffuse Optics in the society. For this purpose, the group carries out several activities in the academic and non-academic community. The group is also committed to the professional development of our members and motivates the exposition of our work into the scientific community.

  9. Optical activity in planar chiral metamaterials: Theoretical study

    International Nuclear Information System (INIS)

    Bai, Benfeng; Svirko, Yuri; Turunen, Jari; Vallius, Tuomas

    2007-01-01

    A thorough theoretical study of the optical activity in planar chiral metamaterial (PCM) structures, made of both dielectric and metallic media, is conducted by the analysis of gammadion-shaped nanoparticle arrays. The general polarization properties are first analyzed from an effective-medium perspective, by analogy with natural optical activity, and then verified by rigorous numerical simulation, some of which are corroborated by previous experimental results. The numerical analysis suggests that giant polarization rotation (tens of degrees) may be achieved in the PCM structures with a thickness of only hundreds of nanometers. The artificial optical activity arises from circular birefringence induced by the structural chirality and is enhanced by the guided-mode or surface-plasmon resonances taking place in the structures. There are two polarization conversion types in the dielectric PCMs, whereas only one type in the metallic ones. Many intriguing features of the polarization property of PCMs are also revealed and explained: the polarization effect is reciprocal and vanishes in the symmetrically layered structures; the effect occurs only in the transmitted field, but not in the reflected field; and the polarization spectra of two enantiomeric PCM structures are mirror symmetric to each other. These remarkable properties pave the way for the PCMs to be used as polarization elements in new-generation integrated optical systems

  10. Investigation on dispersion in the active optical waveguide resonator

    Science.gov (United States)

    Qiu, Zihan; Gao, Yining; Xie, Wei

    2018-03-01

    Introducing active gain in the optical waveguide resonator not only compensates the loss, but also can change the dispersion relationship in the ring resonator. It is demonstrated that the group delay time is negative when the resonator is in the undercoupled condition, which also means the resonator exhibits the fast light effect. Theoretical analysis indicates that fast light effect due to anomalous dispersion, would be manipulated by the gain coefficient controlled by the input pump light power and that fast light would enhance scale factor of the optical resonant gyroscope. Resonance optical gyroscope (ROG)'s scale factor for measuring rotation rate is enhanced by anomalous dispersion with superluminal light propagation. The sensitivity of ROG could be enhanced by anomalous dispersion by coupled resonators even considering the effect of anomalous dispersion and propagation gain on broadened linewidth, and this could result in at least two orders of magnitude enhancement in sensitivity.

  11. Sex-sorting sperm using flow cytometry/cell sorting.

    Science.gov (United States)

    Garner, Duane L; Evans, K Michael; Seidel, George E

    2013-01-01

    The sex of mammalian offspring can be predetermined by flow sorting relatively pure living populations of X- and Y-chromosome-bearing sperm. This method is based on precise staining of the DNA of sperm with the nucleic acid-specific fluorophore, Hoechst 33342, to differentiate between the subpopulations of X- and Y-sperm. The fluorescently stained sperm are then sex-sorted using a specialized high speed sorter, MoFlo(®) SX XDP, and collected into biologically supportive media prior to reconcentration and cryopreservation in numbers adequate for use with artificial insemination for some species or for in vitro fertilization. Sperm sorting can provide subpopulations of X- or Y-bearing bovine sperm at rates in the 8,000 sperm/s range while maintaining; a purity of 90% such that it has been applied to cattle on a commercial basis. The sex of offspring has been predetermined in a wide variety of mammalian species including cattle, swine, horses, sheep, goats, dogs, cats, deer, elk, dolphins, water buffalo as well as in humans using flow cytometric sorting of X- and Y-sperm.

  12. Learning banknote fitness for sorting

    NARCIS (Netherlands)

    Geusebroek, J.M.; Markus, P.; Balke, P.

    2011-01-01

    In this work, a machine learning method is proposed for banknote soiling determination. We apply proven techniques from computer vision to come up with a robust and effective method for automatic sorting of banknotes. The proposed method is evaluated with respect to various invariance classes. The

  13. Quantum lower bound for sorting

    OpenAIRE

    Shi, Yaoyun

    2000-01-01

    We prove that \\Omega(n log(n)) comparisons are necessary for any quantum algorithm that sorts n numbers with high success probability and uses only comparisons. If no error is allowed, at least 0.110nlog_2(n) - 0.067n + O(1) comparisons must be made. The previous known lower bound is \\Omega(n).

  14. Sorting out river channel patterns

    NARCIS (Netherlands)

    Kleinhans, M.G.

    2010-01-01

    Rivers self-organize their pattern/planform through feedbacks between bars, channels, floodplain and vegetation, which emerge as a result of the basic spatial sorting process of wash load sediment and bed sediment. The balance between floodplain formation and destruction determines the width and

  15. Raman Optical Activity and Raman Spectra of Amphetamine Species

    DEFF Research Database (Denmark)

    Berg, Rolf W.; Shim, Irene; White, Peter Cyril

    2012-01-01

    Theoretical calculations and preliminary measurements of vibrational Raman optical activity (ROA) spectra of different species of amphetamine (amphetamine and amphetamine-H+) are reported for the first time. The quantum chemical calculations were carried out as hybrid ab initio DFT-molecular orbi......Theoretical calculations and preliminary measurements of vibrational Raman optical activity (ROA) spectra of different species of amphetamine (amphetamine and amphetamine-H+) are reported for the first time. The quantum chemical calculations were carried out as hybrid ab initio DFT...... are employed for identification purposes. The DFT calculations show that the most stable conformations are those allowing for close contact between the aromatic ring and the amine hydrogen atoms. The internal rotational barrier within the same amphetamine enanti- omer has a considerable influence on the Raman...

  16. Diamagnetic Raman Optical Activity of Chlorine, Bromine, and Iodine Gases

    Czech Academy of Sciences Publication Activity Database

    Šebestík, Jaroslav; Kapitán, J.; Pačes, Ondřej; Bouř, Petr

    2016-01-01

    Roč. 55, č. 10 (2016), s. 3504-3508 ISSN 1433-7851 R&D Projects: GA ČR GA13-03978S; GA ČR(CZ) GA14-00431S; GA ČR(CZ) GA16-05935S Institutional support: RVO:61388963 Keywords : angular momentum theory * diamagnetic molecules * excited electronic states * magnetic field * Raman optical activity Subject RIV: CC - Organic Chemistry Impact factor: 11.994, year: 2016

  17. Explicit versus Implicit Solvent Modeling of Raman Optical Activity Spectra

    Czech Academy of Sciences Publication Activity Database

    Hopmann, K. H.; Ruud, K.; Pecul, M.; Kudelski, A.; Dračínský, Martin; Bouř, Petr

    2011-01-01

    Roč. 115, č. 14 (2011), s. 4128-4137 ISSN 1520-6106 R&D Projects: GA MŠk(CZ) LH11033; GA ČR GAP208/11/0105 Grant - others:AV ČR(CZ) M200550902 Institutional research plan: CEZ:AV0Z40550506 Keywords : raman optical activity * lactamide * solvent models Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.696, year: 2011

  18. Optical activity via Kerr nonlinearity in a spinning chiral medium

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Anwar Ali, E-mail: anwarali@uom.edu.pk [Department of Physics, University of Malakand at Chakdara Dir(L) (Pakistan); Bacha, Bakht Amin, E-mail: aminoptics@gmail.com [Department of Physics, University of Malakand at Chakdara Dir(L) (Pakistan); Khan, Rahmat Ali, E-mail: rahmat_alipk@yahoo.com [Department of Mathematics, University of Malakand (Pakistan)

    2016-11-11

    Optical activity is investigated in a chiral medium by employing the four level cascade atomic model, in which the optical responses of the atomic medium are studied with Kerr nonlinearity. Light entering into a chiral medium splits into circular birefringent beams. The angle of divergence between the circular birefringent beams and the polarization states of the two light beams is manipulated with Kerr nonlinearity. In the stationary chiral medium the angle of divergence between the circular birefringent beams is calculated to be 1.3 radian. Furthermore, circular birefringence is optically controlled in a spinning chiral medium, where the maximum rotary photon drag angle for left (right) circularly polarized beam is ±1.1 (±1.5) microradian. The change in the angle of divergence between circular birefringent beams by rotary photon drag is calculated to be 0.4 microradian. The numerical results may help to understand image designing, image coding, discovery of photonic crystals and optical sensing technology. - Highlights: • Coherent control of a circular birefringence in a chiral medium is studied. • Angle of divergence between birefringent beams is modified with Kerr nonlinearity. • Rotary photon drag is controlled for birefringent beams and enhanced with Kerr nonlinearity in a spinning medium. • Rotation of the angle of divergence is observed with mechanical rotation of the medium about an axis and modified with Kerr effect. • A change in the angle of divergence is calculated by about a microradian with rotary photon drag.

  19. Recent progress in multi-electrode spike sorting methods.

    Science.gov (United States)

    Lefebvre, Baptiste; Yger, Pierre; Marre, Olivier

    2016-11-01

    In recent years, arrays of extracellular electrodes have been developed and manufactured to record simultaneously from hundreds of electrodes packed with a high density. These recordings should allow neuroscientists to reconstruct the individual activity of the neurons spiking in the vicinity of these electrodes, with the help of signal processing algorithms. Algorithms need to solve a source separation problem, also known as spike sorting. However, these new devices challenge the classical way to do spike sorting. Here we review different methods that have been developed to sort spikes from these large-scale recordings. We describe the common properties of these algorithms, as well as their main differences. Finally, we outline the issues that remain to be solved by future spike sorting algorithms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Last results of MADRAS, a space active optics demonstrator

    Science.gov (United States)

    Laslandes, Marie; Hourtoule, Claire; Hugot, Emmanuel; Ferrari, Marc; Devilliers, Christophe; Liotard, Arnaud; Lopez, Céline; Chazallet, Frédéric

    2017-11-01

    The goal of the MADRAS project (Mirror Active, Deformable and Regulated for Applications in Space) is to highlight the interest of Active Optics for the next generation of space telescope and instrumentation. Wave-front errors in future space telescopes will mainly come from thermal dilatation and zero gravity, inducing large lightweight primary mirrors deformation. To compensate for these effects, a 24 actuators, 100 mm diameter deformable mirror has been designed to be inserted in a pupil relay. Within the project, such a system has been optimized, integrated and experimentally characterized. The system is designed considering wave-front errors expected in 3m-class primary mirrors, and taking into account space constraints such as compactness, low weight, low power consumption and mechanical strength. Finite Element Analysis allowed an optimization of the system in order to reach a precision of correction better than 10 nm rms. A dedicated test-bed has been designed to fully characterize the integrated mirror performance in representative conditions. The test set up is made of three main parts: a telescope aberrations generator, a correction loop with the MADRAS mirror and a Shack-Hartman wave-front sensor, and PSF imaging. In addition, Fizeau interferometry monitors the optical surface shape. We have developed and characterized an active optics system with a limited number of actuators and a design fitting space requirements. All the conducted tests tend to demonstrate the efficiency of such a system for a real-time, in situ wave-front. It would allow a significant improvement for future space telescopes optical performance while relaxing the specifications on the others components.

  1. Optical activities of steroid ketones - Elucidation of the octant rule.

    Science.gov (United States)

    Hatanaka, Masashi; Sayama, Daisuke; Miyasaka, Makoto

    2018-04-21

    Theoretical calculations of optical activities in steroid ketones are presented by using modern semi-empirical PM7 wavefunctions. Both circular dichroism (CD) and specific rotation, which is proportional to optical rotation dispersion (ORD), are well simulated, and signs of the Cotton effect at the most long-wavelength region are fully in accordance with the experimental results. The good accordance is related to the octant rule, which is deduced within the framework of the perturbation theory. Our treatment is promising to predict the signs of the Cotton effect of large molecules, and thus, the absolute configurations can also be grasped without demanding procedures. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Optical Assessment of Caries Lesion Structure and Activity

    Science.gov (United States)

    Lee, Robert Chulsung

    New, more sophisticated diagnostic tools are needed for the detection and characterization of caries lesions in the early stages of development. It is not sufficient to simply detect caries lesions, methods are needed to assess the activity of the lesion and determine if chemical or surgical intervention is needed. Previous studies have demonstrated that polarization sensitive optical coherence tomography (PS-OCT) can be used to nondestructively image the subsurface lesion structure and measure the thickness of the highly mineralized surface zone. Other studies have demonstrated that the rate of dehydration can be correlated with the lesion activity and that the rate can be measured using optical methods. The main objective of this work was to test the hypothesis that optical methods can be used to assess lesion activity on tooth coronal and root surfaces. Simulated caries models were used to develop and validate an algorithm for detecting and measuring the highly mineralized surface layer using PS-OCT. This work confirmed that the algorithm was capable of estimating the thickness of the highly mineralized surface layer with high accuracy. Near-infrared (NIR) reflectance and thermal imaging methods were used to assess activity of caries lesions by measuring the state of lesion hydration. NIR reflectance imaging performed the best for artificial enamel and natural coronal caries lesion samples, particularly at wavelengths coincident with the water absorption band at 1460-nm. However, thermal imaging performed the best for artificial dentin and natural root caries lesion samples. These novel optical methods outperformed the conventional methods (ICDAS II) in accurately assessing lesion activity of natural coronal and root caries lesions. Infrared-based imaging methods have shown potential for in-vivo applications to objectively assess caries lesion activity in a single examination. It is likely that if future clinical trials are a success, this novel imaging

  3. Sorting fluorescent nanocrystals with DNA

    Energy Technology Data Exchange (ETDEWEB)

    Gerion, Daniele; Parak, Wolfgang J.; Williams, Shara C.; Zanchet, Daniela; Micheel, Christine M.; Alivisatos, A. Paul

    2001-12-10

    Semiconductor nanocrystals with narrow and tunable fluorescence are covalently linked to oligonucleotides. These biocompounds retain the properties of both nanocrystals and DNA. Therefore, different sequences of DNA can be coded with nanocrystals and still preserve their ability to hybridize to their complements. We report the case where four different sequences of DNA are linked to four nanocrystal samples having different colors of emission in the range of 530-640 nm. When the DNA-nanocrystal conjugates are mixed together, it is possible to sort each type of nanoparticle using hybridization on a defined micrometer -size surface containing the complementary oligonucleotide. Detection of sorting requires only a single excitation source and an epifluorescence microscope. The possibility of directing fluorescent nanocrystals towards specific biological targets and detecting them, combined with their superior photo-stability compared to organic dyes, opens the way to improved biolabeling experiments, such as gene mapping on a nanometer scale or multicolor microarray analysis.

  4. Flow cytogenetics and chromosome sorting.

    Science.gov (United States)

    Cram, L S

    1990-06-01

    This review of flow cytogenetics and chromosome sorting provides an overview of general information in the field and describes recent developments in more detail. From the early developments of chromosome analysis involving single parameter or one color analysis to the latest developments in slit scanning of single chromosomes in a flow stream, the field has progressed rapidly and most importantly has served as an important enabling technology for the human genome project. Technological innovations that advanced flow cytogenetics are described and referenced. Applications in basic cell biology, molecular biology, and clinical investigations are presented. The necessary characteristics for large number chromosome sorting are highlighted. References to recent review articles are provided as a starting point for locating individual references that provide more detail. Specific references are provided for recent developments.

  5. School accountability Incentives or sorting?

    OpenAIRE

    Hege Marie Gjefsen; Trude Gunnes

    2015-01-01

    We exploit a nested school accountability reform to estimate the causal effect on teacher mobility, sorting, and student achievement. In 2003, lower-secondary schools in Oslo became accountable to the school district authority for student achievement. In 2005, information on school performance in lower secondary education also became public. Using a difference-in-difference-in-difference approach, we find a significant increase in teacher mobility and that almost all non-stayers leave the tea...

  6. External parallel sorting with multiprocessor computers

    International Nuclear Information System (INIS)

    Comanceau, S.I.

    1984-01-01

    This article describes methods of external sorting in which the entire main computer memory is used for the internal sorting of entries, forming out of them sorted segments of the greatest possible size, and outputting them to external memories. The obtained segments are merged into larger segments until all entries form one ordered segment. The described methods are suitable for sequential files stored on magnetic tape. The needs of the sorting algorithm can be met by using the relatively slow peripheral storage devices (e.g., tapes, disks, drums). The efficiency of the external sorting methods is determined by calculating the total sorting time as a function of the number of entries to be sorted and the number of parallel processors participating in the sorting process

  7. Sorting and selection in posets

    DEFF Research Database (Denmark)

    Daskalakis, Constantinos; Karp, Richard M.; Mossel, Elchanan

    2011-01-01

    from two decades ago by Faigle and Turán. In particular, we present the first algorithm that sorts a width-$w$ poset of size $n$ with query complexity $O(n(w+\\log n))$ and prove that this query complexity is asymptotically optimal. We also describe a variant of Mergesort with query complexity $O......(wn\\log\\frac{n}{w})$ and total complexity $O(w^{2}n\\log\\frac{n}{w})$; an algorithm with the same query complexity was given by Faigle and Turán, but no efficient implementation of that algorithm is known. Both our sorting algorithms can be applied with negligible overhead to the more general problem of reconstructing transitive......Classical problems of sorting and searching assume an underlying linear ordering of the objects being compared. In this paper, we study these problems in the context of partially ordered sets, in which some pairs of objects are incomparable. This generalization is interesting from a combinatorial...

  8. Perbandingan Bubble Sort dengan Insertion Sort pada Bahasa Pemrograman C dan Fortran

    Directory of Open Access Journals (Sweden)

    Reina Reina

    2013-12-01

    Full Text Available Sorting is a basic algorithm studied by students of computer science major. Sorting algorithm is the basis of other algorithms such as searching algorithm, pattern matching algorithm. Bubble sort is a popular basic sorting algorithm due to its easiness to be implemented. Besides bubble sort, there is insertion sort. It is lesspopular than bubble sort because it has more difficult algorithm. This paper discusses about process time between insertion sort and bubble sort with two kinds of data. First is randomized data, and the second is data of descending list. Comparison of process time has been done in two kinds of programming language that is C programming language and FORTRAN programming language. The result shows that bubble sort needs more time than insertion sort does.

  9. Calculation of optical second-harmonic susceptibilities and optical activity for crystals

    International Nuclear Information System (INIS)

    Levine, Z.H.

    1994-01-01

    A new generation of nearly first-principles calculations predicts both the linear and second-harmonic susceptibilities for a variety of insulating crystals, including GaAs, GaP, AlAs, AlP, Se, α-quartz, and c-urea. The results are typically in agreement with experimental measurements. The calculations have been extended to optical activity, with somewhat less success to date. The theory, based on a simple self-energy correction to the local density approximation, and results are reviewed herein

  10. Assembling optically active and nonactive metamaterials with chiral units

    Directory of Open Access Journals (Sweden)

    Xiang Xiong

    2012-12-01

    Full Text Available Metamaterials constructed with chiral units can be either optically active or nonactive depending on the spatial configuration of the building blocks. For a class of chiral units, their effective induced electric and magnetic dipoles, which originate from the induced surface electric current upon illumination of incident light, can be collinear at the resonant frequency. This feature provides significant advantage in designing metamaterials. In this paper we concentrate on several examples. In one scenario, chiral units with opposite chiralities are used to construct the optically nonactive metamaterial structure. It turns out that with linearly polarized incident light, the pure electric or magnetic resonance (and accordingly negative permittivity or negative permeability can be selectively realized by tuning the polarization of incident light for 90°. Alternatively, units with the same chirality can be assembled as a chiral metamaterial by taking the advantage of the collinear induced electric and magnetic dipoles. It follows that for the circularly polarized incident light, negative refractive index can be realized. These examples demonstrate the unique approach to achieve certain optical properties by assembling chiral building blocks, which could be enlightening in designing metamaterials.

  11. Optical manipulation and catalytic activity enhanced by surface plasmon effect

    Science.gov (United States)

    Zou, Ningmu; Min, Jiang; Jiao, Wenxiang; Wang, Guanghui

    2017-02-01

    For optical manipulation, a nano-optical conveyor belt consisting of an array of gold plasmonic non-concentric nano-rings (PNNRs) is demonstrated for the realization of trapping and unidirectional transportation of nanoparticles by polarization rotation of excitation beam. These hot spots of an asymmetric plasmonic nanostructure are polarization dependent, therefore, one can use the incident polarization state to manipulate the trapped targets. Trapped particles could be transferred between adjacent PNNRs in a given direction just by rotating the polarization of incident beam due to unbalanced potential. The angular dependent distribution of electric field around PNNR has been solved using the three- dimensional finite-difference time-domain (FDTD) technique. For optical enhanced catalytic activity, the spectral properties of dimers of Au nanorod-Au nanorod nanostructures under the excitation of 532nm photons have been investigated. With a super-resolution catalytic mapping technique, we identified the existence of "hot spot" in terms of catalytic reactivity at the gap region within the twined plasmonic nanostructure. Also, FDTD calculation has revealed an intrinsic correlation between hot electron transfer.

  12. (Bio)hybrid materials based on optically active particles

    Science.gov (United States)

    Reitzig, Manuela; Härtling, Thomas; Opitz, Jörg

    2014-03-01

    In this contribution we provide an overview of current investigations on optically active particles (nanodiamonds, upconversion phospors) for biohybrid and sensing applications. Due to their outstanding properties nanodiamonds gain attention in various application elds such as microelectronics, optical monitoring, medicine, and biotechnology. Beyond the typical diamond properties such as high thermal conductivity and extreme hardness, the carbon surface and its various functional groups enable diverse chemical and biological surface functionalization. At Fraunhofer IKTS-MD we develop a customization of material surfaces via integration of chemically modi ed nanodiamonds at variable surfaces, e.g bone implants and pipelines. For the rst purpose, nanodiamonds are covalently modi ed at their surface with amino or phosphate functionalities that are known to increase adhesion to bone or titanium alloys. The second type of surface is approached via mechanical implementation into coatings. Besides nanodiamonds, we also investigate the properties of upconversion phosphors. In our contribution we show how upconversion phosphors are used to verify sterilization processes via a change of optical properties due to sterilizing electron beam exposure.

  13. Zeno inhibition of polarization rotation in an optically active medium

    International Nuclear Information System (INIS)

    Gonzalo, Isabel; Luis, Alfredo; Porras, Miguel A

    2015-01-01

    We describe an experiment in which the rotation of the polarization of light propagating in an optically active water solution of D-fructose tends to be inhibited by frequent monitoring whether the polarization remains unchanged. This is an example of the Zeno effect that has remarkable pedagogical interest because of its conceptual simplicity, easy implementation, low cost, and because the same the Zeno effect holds at classical and quantum levels. An added value is the demonstration of the Zeno effect beyond typical idealized assumptions in a practical setting with real polarizers. (paper)

  14. Dispersion relations and sum rules for natural optical activity

    International Nuclear Information System (INIS)

    Thomaz, M.T.; Nussenzveig, H.M.

    1981-06-01

    Dispersion relations and sum rules are derived for the complex rotatory power of an arbitrary linear (nonmagnetic) isotropic medium showing natural optical activity. Both previously known dispersion relations and sum rules as well as new ones are obtained. It is shown that the Rosenfeld-Condon dispersion formula is inconsistent with the expected asymptotic behavior at high frequencies. A new dispersion formula based on quantum eletro-dynamics removes this inconsistency; however, it still requires modification in the low-frequency limit. (Author) [pt

  15. Transition polarizability model of induced resonance Raman optical activity

    Czech Academy of Sciences Publication Activity Database

    Yamamoto, S.; Bouř, Petr

    2013-01-01

    Roč. 34, č. 25 (2013), s. 2152-2158 ISSN 0192-8651 R&D Projects: GA ČR GAP208/11/0105; GA ČR GA13-03978S; GA MŠk(CZ) LH11033 Grant - others:AV ČR(CZ) M200551205 Institutional support: RVO:61388963 Keywords : induced resonance Raman optical activity * europium complexes * density functional computations * light scattering Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.601, year: 2013

  16. Molecular structures of viruses from Raman optical activity

    DEFF Research Database (Denmark)

    Blanch, Ewan W.; Hecht, Lutz; Syme, Christopher D.

    2002-01-01

    A vibrational Raman optical activity (ROA) study of a range of different structural types of virus exemplified by filamentous bacteriophage fd, tobacco mosaic virus, satellite tobacco mosaic virus, bacteriophage MS2 and cowpea mosaic virus has revealed that, on account of its sensitivity to chira......A vibrational Raman optical activity (ROA) study of a range of different structural types of virus exemplified by filamentous bacteriophage fd, tobacco mosaic virus, satellite tobacco mosaic virus, bacteriophage MS2 and cowpea mosaic virus has revealed that, on account of its sensitivity...... (top component) of cowpea mosaic virus from those of the intact middle and bottom-upper components separated by means of a caesium chloride density gradient, the ROA spectrum of the viral RNA was obtained, which revealed that the RNA takes up an A-type single-stranded helical conformation...... and that the RNA conformations in the middle and bottom-upper components are very similar. This information is not available from the X-ray crystal structure of cowpea mosaic virus since no nucleic acid is visible....

  17. Design of integrated optics all-optical label swappers for spectral amplitude code label swapping optical packet networks on active/passive InP technology

    NARCIS (Netherlands)

    Habib, C.; Munoz, P.; Leijtens, X.J.M.; Chen, Lawrence; Smit, M.K.; Capmany, J.

    2009-01-01

    In this paper the designs of optical label swapper devices, for spectral amplitude coded labels, monolithically integrated on InP active/passive technology are pre sented. The devices are based on cross-gain modulation in a semiconductor optical amplifier. Multi-wavelength operation is enabled by

  18. "A Shock of Electricity Just Sort of Goes through My Body": Physical Activity and Embodied Reflexive Practices in Young Female Ballet Dancers

    Science.gov (United States)

    Wellard, Ian; Pickard, Angela; Bailey, Richard

    2007-01-01

    Participation in physical activities, in and out of school, remains heavily influenced by social constructions of gendered behaviour. In addition, the body plays a significant part in the presentation of legitimate performances of physical practice and the construction of a physical "identity". The consequence is that in formalized…

  19. Optically active vibrational modes of PPV derivatives on textile substrate

    International Nuclear Information System (INIS)

    Silva, M.A.T. da; Dias, I.F.L.; Santos, E.P. dos; Martins, A.A.; Duarte, J.L.; Laureto, E.; Reis, G.A. dos; Guimarães, P.S.S.; Cury, L.A.

    2013-01-01

    In this work, MEH-PPV and BDMO-PPV films were deposited by spin-coating on “dirty” textile substrates of canvas, nylon, canvas with resin, jeans and on glass and the temperature dependence of the optical properties of them was studied by photoluminescence and Raman (300 K) techniques. The temperature dependence of the energy, of the half line width at half height of the purely electronic peak, of the integrated PL intensity and of the Huang-Rhys factor, S=I (01) /I (00) , were obtained directly from the PL spectrum. For an analysis of the vibrational modes involved, Raman measurements were performed on substrates with and without polymers deposited and the results compared with those found in the literature. The films of MEH-PPV and BDMO-PPV showed optical properties similar to those films deposited on other substrates such as glass, metals, etc. It was observed an inversion of the first vibrational band in relation to the purely electronic peak with increasing temperature in the films deposited on nylon and canvas. The vibrational modes obtained by Raman were used to compose the simulation of the PL line shape of BDMO-PPV films on canvas and nylon, using a model proposed by Lin [29]. - Highlights: ► MEH-PPV and BDMO-PPV films were deposited by spin-coating on dirty textile. ► Their properties were studied by photoluminescence and Raman techniques. ► We observed inversion of first vibrational band in relation to purely electronic peak. ► Optically active vibrational modes of PPV derivatives were studied.

  20. Discovery Channel Telescope active optics system early integration and test

    Science.gov (United States)

    Venetiou, Alexander J.; Bida, Thomas A.

    2012-09-01

    The Discovery Channel Telescope (DCT) is a 4.3-meter telescope with a thin meniscus primary mirror (M1) and a honeycomb secondary mirror (M2). The optical design is an f/6.1 Ritchey-Chrétien (RC) with an unvignetted 0.5° Field of View (FoV) at the Cassegrain focus. We describe the design, implementation and performance of the DCT active optics system (AOS). The DCT AOS maintains collimation and controls the figure of the mirror to provide seeing-limited images across the focal plane. To minimize observing overhead, rapid settling times are achieved using a combination of feed-forward and low-bandwidth feedback control using a wavefront sensing system. In 2011, we mounted a Shack-Hartmann wavefront sensor at the prime focus of M1, the Prime Focus Test Assembly (PFTA), to test the AOS with the wavefront sensor, and the feedback loop. The incoming wavefront is decomposed using Zernike polynomials, and the mirror figure is corrected with a set of bending modes. Components of the system that we tested and tuned included the Zernike to Bending Mode transformations. We also started open-loop feed-forward coefficients determination. In early 2012, the PFTA was replaced by M2, and the wavefront sensor moved to its normal location on the Cassegrain instrument assembly. We present early open loop wavefront test results with the full optical system and instrument cube, along with refinements to the overall control loop operating at RC Cassegrain focus.

  1. Energy efficient data sorting using standard sorting algorithms

    KAUST Repository

    Bunse, Christian; Hö pfner, Hagen; Roychoudhury, Suman; Mansour, Essam

    2011-01-01

    Protecting the environment by saving energy and thus reducing carbon dioxide emissions is one of todays hottest and most challenging topics. Although the perspective for reducing energy consumption, from ecological and business perspectives is clear, from a technological point of view, the realization especially for mobile systems still falls behind expectations. Novel strategies that allow (software) systems to dynamically adapt themselves at runtime can be effectively used to reduce energy consumption. This paper presents a case study that examines the impact of using an energy management component that dynamically selects and applies the "optimal" sorting algorithm, from an energy perspective, during multi-party mobile communication. Interestingly, the results indicate that algorithmic performance is not key and that dynamically switching algorithms at runtime does have a significant impact on energy consumption. © Springer-Verlag Berlin Heidelberg 2011.

  2. Spike sorting for polytrodes: a divide and conquer approach

    Directory of Open Access Journals (Sweden)

    Nicholas V. Swindale

    2014-02-01

    Full Text Available In order to determine patterns of neural activity, spike signals recorded by extracellular electrodes have to be clustered (sorted with the aim of ensuring that each cluster represents all the spikes generated by an individual neuron. Many methods for spike sorting have been proposed but few are easily applicable to recordings from polytrodes which may have 16 or more recording sites. As with tetrodes, these are spaced sufficiently closely that signals from single neurons will usually be recorded on several adjacent sites. Although this offers a better chance of distinguishing neurons with similarly shaped spikes, sorting is difficult in such cases because of the high dimensionality of the space in which the signals must be classified. This report details a method for spike sorting based on a divide and conquer approach. Clusters are initially formed by assigning each event to the channel on which it is largest. Each channel-based cluster is then sub-divided into as many distinct clusters as possible. These are then recombined on the basis of pairwise tests into a final set of clusters. Pairwise tests are also performed to establish how distinct each cluster is from the others. A modified gradient ascent clustering (GAC algorithm is used to do the clustering. The method can sort spikes with minimal user input in times comparable to real time for recordings lasting up to 45 minutes. Our results illustrate some of the difficulties inherent in spike sorting, including changes in spike shape over time. We show that some physiologically distinct units may have very similar spike shapes. We show that RMS measures of spike shape similarity are not sensitive enough to discriminate clusters that can otherwise be separated by principal components analysis. Hence spike sorting based on least-squares matching to templates may be unreliable. Our methods should be applicable to tetrodes and scaleable to larger multi-electrode arrays (MEAs.

  3. Changing University Students’ Alternative Conceptions of Optics by Active Learning

    Directory of Open Access Journals (Sweden)

    Zalkida Hadžibegović

    2013-01-01

    Full Text Available Active learning is individual and group participation in effective activities such as in-class observing, writing, experimenting, discussion, solving problems, and talking about to-be-learned topics. Some instructors believe that active learning is impossible, or at least extremely difficult to achieve in large lecture sessions. Nevertheless, the truly impressive implementation results of theSCALE-UP learning environment suggest that such beliefs are false (Beichner et al., 2000. In this study, we present a design of an active learning environment with positive effect on students. The design is based on the following elements: (1 helping students to learn from interactive lecture experiment; (2 guiding students to use justified explanation and prediction after observing and exploring a phenomenon; (3 developing a conceptual question sequencedesigned for use in an interactive lecture with students answering questions in worksheets by writing and drawing; (4 evaluating students’ conceptual change and gains by questions related to light reflection, refraction, and image formation in an exam held a week after the active learning session. Data were collected from 95 science freshmen with different secondary school backgrounds. They participated in geometrical optics classes organized for collecting research results during and after only one active learning session.The results have showed that around 60% of the students changed their initial alternative conceptions of vision and of image formation. It was also found that a large group of university students is likely to be engaged in active learning, shifting from a passive role they usually play during teacher’s lectures.

  4. Optical monitoring of Active Galactic Nuclei from ARIES

    Science.gov (United States)

    Gopal-Krishna; Wiita, Paul Joseph

    2018-04-01

    This overview provides a historical perspective highlighting the pioneering role which the fairly modest observational facilities of ARIES have played since the 1990s in systematically characterizing the optical variability on hour-like time scale (intra-night optical variability, or INOV) of several major types of high-luminosity Active Galactic Nuclei (AGN). Such information was previously available only for blazars. Similar studies have since been initiated in at least a dozen countries, giving a boost to AGN variability research. Our work has, in particular, provided strong indication that mild INOV occurs in radio-quiet QSOs (amplitude up to 3 – 5 % and duty cycle 10%) and, moreover, has demonstrated that similarly mild INOV is exhibited even by the vast majority of radio-loud quasars which possess powerful relativistic jets (even including many that are beamed towards us). The solitary outliers are blazars, the tiny strongly polarized subset of powerful AGN, which frequently exhibit a pronounced INOV. Among the blazars, BL Lac objects often show a bluer-when-brighter chromatic behavior, while the flat spectrum radio quasars seem not to. Quantifying any differences of INOV among the major subclasses of non-blazar type AGNs will require dedicated monitoring programs using 2 - 3 metre class telescopes.

  5. Optical spectral properties of active galactic nuclei and quasars

    International Nuclear Information System (INIS)

    Yee, H.K.C.

    1981-01-01

    Four separate investigations dealing with the properties of optical continuum and emission-lines of active galactic nuclei (AGN) and quasars are presented. Multichannel scans of 3CR radio galaxies are decomposed by using a two-component model-an elliptical galaxy and a power-law nonthermal component. It is found that there is a strong correlation between the luminosity of the power-law component and the strength of the Balmer emission-lines. In most cases, by extrapolating to the Lyman continuum, the power-law models derived provide enough ionizing radiation to account for the Balmer line strengths. Extending the study of radio galaxies to include Seyfert galaxies and quasars, it is found that there is a strong continuity between broad-line AGN's and quasars in terms of similarities in the correlations between line luminosities and nonthermal continuum luminosity. Next, a study of the variability of absolute optical energy distribution and emission-lines of the N-galaxies 3C382 and 3C390.3 is made. Lastly, a preliminary study of surface photometry of Markarian Seyfert galaxies are presented. It is found that the properties of the underlying galaxies such as scale-length and surface brightness of the disk, color, and total brightness, do not depart systematically from those of luminous normal spiral galaxies

  6. Resistance to inhibitors of cholinesterase (Ric-8A and Gαi contribute to cytokinesis abscission by controlling vacuolar protein-sorting (Vps34 activity.

    Directory of Open Access Journals (Sweden)

    Cedric Boularan

    Full Text Available Resistance to inhibitors of cholinesterase (Ric-8A is a guanine nucleotide exchange factor for Gαi, Gαq, and Gα12/13, which is implicated in cell signaling and as a molecular chaperone required for the initial association of nascent Gα subunits with cellular membranes. Ric-8A, Gαi subunits, and their regulators are localized at the midbody prior to abscission and linked to the final stages of cell division. Here, we identify a molecular mechanism by which Ric-8A affects cytokinesis and abscission by controlling Vps34 activity. We showed that Ric-8A protein expression is post-transcriptionally controlled during the cell cycle reaching its maximum levels at mitosis. A FRET biosensor created to measure conformational changes in Ric-8A by FLIM (Fluorescence Lifetime Imaging Microscopy revealed that Ric-8A was in a close-state during mitosis and particularly so at cytokinesis. Lowering Ric-8A expression delayed the abscission time of dividing cells, which correlated with increased intercellular bridge length and multinucleation. During cytokinesis, Ric-8A co-localized with Vps34 at the midbody along with Gαi and LGN, where these proteins functioned to regulate Vps34 phosphatidylinositol 3-kinase activity.

  7. Laser metrology and optic active control system for GAIA

    Science.gov (United States)

    D'Angelo, F.; Bonino, L.; Cesare, S.; Castorina, G.; Mottini, S.; Bertinetto, F.; Bisi, M.; Canuto, E.; Musso, F.

    2017-11-01

    The Laser Metrology and Optic Active Control (LM&OAC) program has been carried out under ESA contract with the purpose to design and validate a laser metrology system and an actuation mechanism to monitor and control at microarcsec level the stability of the Basic Angle (angle between the lines of sight of the two telescopes) of GAIA satellite. As part of the program, a breadboard (including some EQM elements) of the laser metrology and control system has been built and submitted to functional, performance and environmental tests. In the followings we describe the mission requirements, the system architecture, the breadboard design, and finally the performed validation tests. Conclusion and appraisals from this experience are also reported.

  8. Reverberation Mapping of Optical Emission Lines in Five Active Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Fausnaugh, M. M.; Denney, K. D.; Peterson, B. M.; Kochanek, C. S.; Pogge, R. W.; Brown, Jonathan S.; Coker, C. T. [Department of Astronomy, The Ohio State University, 140 W. 18th Avenue, Columbus, OH 43210 (United States); Grier, C. J.; Beatty, Thomas G. [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States); Bentz, M. C. [Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303 (United States); Rosa, G. De [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Adams, S. M. [Cahill Center for Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Barth, A. J. [Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697 (United States); Bhattacharjee, A.; Brotherton, M. S. [Department of Physics and Astronomy, University of Wyoming, 1000 E. University Avenue, Laramie, WY (United States); Borman, G. A. [Crimean Astrophysical Observatory, P/O Nauchny, Crimea 298409 (Russian Federation); Boroson, T. A. [Las Cumbres Global Telescope Network, 6740 Cortona Drive, Suite 102, Santa Barbara, CA 93117 (United States); Bottorff, M. C. [Fountainwood Observatory, Department of Physics FJS 149, Southwestern University, 1011 E. University Avenue, Georgetown, TX 78626 (United States); Brown, Jacob E. [Department of Physics and Astronomy, University of Missouri, Columbia (United States); Crawford, S. M. [South African Astronomical Observatory, P.O. Box 9, Observatory 7935, Cape Town (South Africa); and others

    2017-05-10

    We present the first results from an optical reverberation mapping campaign executed in 2014 targeting the active galactic nuclei (AGNs) MCG+08-11-011, NGC 2617, NGC 4051, 3C 382, and Mrk 374. Our targets have diverse and interesting observational properties, including a “changing look” AGN and a broad-line radio galaxy. Based on continuum-H β lags, we measure black hole masses for all five targets. We also obtain H γ and He ii λ 4686 lags for all objects except 3C 382. The He ii λ 4686 lags indicate radial stratification of the BLR, and the masses derived from different emission lines are in general agreement. The relative responsivities of these lines are also in qualitative agreement with photoionization models. These spectra have extremely high signal-to-noise ratios (100–300 per pixel) and there are excellent prospects for obtaining velocity-resolved reverberation signatures.

  9. Laser Polarimeter for Measurement of Optical Activity of Biological Objects

    Science.gov (United States)

    Protasov, E. A.; Protasov, D. E.; Ryzhkova, A. V.

    In this paper has been described the polarimetric device for measurement of optical activity of biological tissues, where the source of radiation is an infrared laser with a wave λ=0.808 micron. The polarizers used are polarizing prisms of Glan - Taylor. To obtain required angular resolution (0.180/cm) has been developed a device that converts the angle of rotation of the analyzer into electrical signal, which is fed to the appropriate scan digital oscilloscope. The passage of the polarized light through the fingers of the hand was established and the angles of rotation of the polarization vector of the transmitted radiation were measured, the values of which may be determined by the content of hemoglobin in the blood.

  10. Reverberation Mapping of Optical Emission Lines in Five Active Galaxies

    International Nuclear Information System (INIS)

    Fausnaugh, M. M.; Denney, K. D.; Peterson, B. M.; Kochanek, C. S.; Pogge, R. W.; Brown, Jonathan S.; Coker, C. T.; Grier, C. J.; Beatty, Thomas G.; Bentz, M. C.; Rosa, G. De; Adams, S. M.; Barth, A. J.; Bhattacharjee, A.; Brotherton, M. S.; Borman, G. A.; Boroson, T. A.; Bottorff, M. C.; Brown, Jacob E.; Crawford, S. M.

    2017-01-01

    We present the first results from an optical reverberation mapping campaign executed in 2014 targeting the active galactic nuclei (AGNs) MCG+08-11-011, NGC 2617, NGC 4051, 3C 382, and Mrk 374. Our targets have diverse and interesting observational properties, including a “changing look” AGN and a broad-line radio galaxy. Based on continuum-H β lags, we measure black hole masses for all five targets. We also obtain H γ and He ii λ 4686 lags for all objects except 3C 382. The He ii λ 4686 lags indicate radial stratification of the BLR, and the masses derived from different emission lines are in general agreement. The relative responsivities of these lines are also in qualitative agreement with photoionization models. These spectra have extremely high signal-to-noise ratios (100–300 per pixel) and there are excellent prospects for obtaining velocity-resolved reverberation signatures.

  11. Contamination control research activities for space optics in JAXA RANDD

    Science.gov (United States)

    Kimoto, Y.

    2017-11-01

    Contamination control research activities for space optics projects in JAXA R&D are described. More accurate contamination control techniques are requested because of intensified recent science mission requirements. One approach to control the contamination effects is analysis by software. JAXA has been developing a contamination analytical tool "J-SPICE" (Japanese Spacecraft Induced Contamination analysis software) as well as experiment facilities to improve the J-SPICE. A reflection model in J-SPICE has been experimentally verified and outgassing model data has been acquired by a facility. JAXA has developed a facility which could determine the influence of the contamination at a specific wavelength by combining a vacuum chamber with an I-R spectrometer and performed an experiment to inspect the effect of baking. Space material exposure experiment results reveal the actual thickness of the contamination layer in ISS orbit.

  12. Fixing the Sorting Algorithm for Android, Java and Python

    NARCIS (Netherlands)

    C.P.T. de Gouw (Stijn); F.S. de Boer (Frank)

    2015-01-01

    htmlabstractTim Peters developed the Timsort hybrid sorting algorithm in 2002. TimSort was first developed for Python, a popular programming language, but later ported to Java (where it appears as java.util.Collections.sort and java.util.Arrays.sort). TimSort is today used as the default sorting

  13. Learning sorting algorithms through visualization construction

    Science.gov (United States)

    Cetin, Ibrahim; Andrews-Larson, Christine

    2016-01-01

    Recent increased interest in computational thinking poses an important question to researchers: What are the best ways to teach fundamental computing concepts to students? Visualization is suggested as one way of supporting student learning. This mixed-method study aimed to (i) examine the effect of instruction in which students constructed visualizations on students' programming achievement and students' attitudes toward computer programming, and (ii) explore how this kind of instruction supports students' learning according to their self-reported experiences in the course. The study was conducted with 58 pre-service teachers who were enrolled in their second programming class. They expect to teach information technology and computing-related courses at the primary and secondary levels. An embedded experimental model was utilized as a research design. Students in the experimental group were given instruction that required students to construct visualizations related to sorting, whereas students in the control group viewed pre-made visualizations. After the instructional intervention, eight students from each group were selected for semi-structured interviews. The results showed that the intervention based on visualization construction resulted in significantly better acquisition of sorting concepts. However, there was no significant difference between the groups with respect to students' attitudes toward computer programming. Qualitative data analysis indicated that students in the experimental group constructed necessary abstractions through their engagement in visualization construction activities. The authors of this study argue that the students' active engagement in the visualization construction activities explains only one side of students' success. The other side can be explained through the instructional approach, constructionism in this case, used to design instruction. The conclusions and implications of this study can be used by researchers and

  14. Application of visible spectroscopy in waste sorting

    Science.gov (United States)

    Spiga, Philippe; Bourely, Antoine

    2011-10-01

    Today, waste recycling, (bottles, papers...), is a mechanical operation: the waste are crushed, fused and agglomerated in order to obtain new manufactured products (e.g. new bottles, clothes ...). The plastics recycling is the main application in the color sorting process. The colorless plastics recovered are more valuable than the colored plastics. Other emergent applications are in the paper sorting, where the main goal is to sort dyed paper from white papers. Up to now, Pellenc Selective Technologies has manufactured color sorting machines based on RGB cameras. Three dimensions (red, green and blue) are no longer sufficient to detect low quantities of dye in the considered waste. In order to increase the efficiency of the color detection, a new sorting machine, based on visible spectroscopy, has been developed. This paper presents the principles of the two approaches and their difference in terms of sorting performance, making visible spectroscopy a clear winner.

  15. Active fiber optic technologies used as tamper-indicating devices

    International Nuclear Information System (INIS)

    Horton, P.R.V.; Waddoups, I.G.

    1995-11-01

    The Sandia National Laboratories (SNL) Safeguards and Seals Evaluation Program is evaluating new fiber optic active seal technologies for use at Department of Energy (DOE) facilities. The goal of the program is to investigate active seal technologies that can monitor secured containers storing special nuclear materials (SNM) within DOE vaults. Specifically investigated were active seal technologies that can be used as tamper-indicating devices to monitor secured containers within vaults while personnel remain outside the vault area. Such a system would allow minimal access into vaults while ensuring container content accountability. The purpose of this report is to discuss tamper-indicating devices that were evaluated for possible DOE use. While previous seal evaluations (Phase I and II) considered overall facility applications, this discussion focuses specifically on their use in vault storage situations. The report will highlight general background information, specifications and requirements, and test procedures. Also discussed are the systems available from four manufacturers: Interactive Technologies, Inc., Fiber SenSys, Inc., Inovonics, Inc., and Valve Security Systems

  16. Rapid optical determination of β-lactamase and antibiotic activity

    Science.gov (United States)

    2014-01-01

    Background The absence of rapid tests evaluating antibiotic susceptibility results in the empirical prescription of antibiotics. This can lead to treatment failures due to escalating antibiotic resistance, and also furthers the emergence of drug-resistant bacteria. This study reports a rapid optical method to detect β-lactamase and thereby assess activity of β-lactam antibiotics, which could provide an approach for targeted prescription of antibiotics. The methodology is centred on a fluorescence quenching based probe (β-LEAF – β-Lactamase Enzyme Activated Fluorophore) that mimics the structure of β-lactam antibiotics. Results The β-LEAF assay was performed for rapid determination of β-lactamase production and activity of β-lactam antibiotic (cefazolin) on a panel of Staphylococcus aureus ATCC strains and clinical isolates. Four of the clinical isolates were determined to be lactamase producers, with the capacity to inactivate cefazolin, out of the twenty-five isolates tested. These results were compared against gold standard methods, nitrocefin disk test for β-lactamase detection and disk diffusion for antibiotic susceptibility, showing results to be largely consistent. Furthermore, in the sub-set of β-lactamase producers, it was demonstrated and validated that multiple antibiotics (cefazolin, cefoxitin, cefepime) could be assessed simultaneously to predict the antibiotic that would be most active for a given bacterial isolate. Conclusions The study establishes the rapid β-LEAF assay for β-lactamase detection and prediction of antibiotic activity using S. aureus clinical isolates. Although the focus in the current study is β-lactamase-based resistance, the overall approach represents a broad diagnostic platform. In the long-term, these studies form the basis for the development of assays utilizing a broader variety of targets, pathogens and drugs. PMID:24708478

  17. On the Construction of Sorted Reactive Systems

    DEFF Research Database (Denmark)

    Birkedal, Lars; Debois, Søren; Hildebrandt, Thomas

    2008-01-01

    We develop a theory of sorted bigraphical reactive systems. Every application of bigraphs in the literature has required an extension, a sorting, of pure bigraphs. In turn, every such application has required a redevelopment of the theory of pure bigraphical reactive systems for the sorting at hand...... bigraphs. Technically, we give our construction for ordinary reactive systems, then lift it to bigraphical reactive systems. As such, we give also a construction of sortings for ordinary reactive systems. This construction is an improvement over previous attempts in that it produces smaller and much more...

  18. Polarization ray tracing in anisotropic optically active media. II. Theory and physics

    International Nuclear Information System (INIS)

    McClain, S.C.; Hillman, L.W.; Chipman, R.A.

    1993-01-01

    Refraction, reflection, and amplitude relations are derived that apply to polarization ray tracing in anisotropic, optically active media such as quartz. The constitutive relations for quartz are discussed. The refractive indices and polarization states associated with the two modes of propagation are derived as a function of wave direction. A procedure for refracting at any uniaxial or optically active interface is derived that computes both the ray direction and the wave direction. A method for computing the optical path length is given, and Fresnel transmission and ref lection equations are derived from boundary conditions on the electromagnetic fields. These ray-tracing formulas apply to uniaxial, optically active media and therefore encompass uniaxial, non-optically active materials and isotropic, optically active materials

  19. Optics

    CERN Document Server

    Mathieu, Jean Paul

    1975-01-01

    Optics, Parts 1 and 2 covers electromagnetic optics and quantum optics. The first part of the book examines the various of the important properties common to all electromagnetic radiation. This part also studies electromagnetic waves; electromagnetic optics of transparent isotropic and anisotropic media; diffraction; and two-wave and multi-wave interference. The polarization states of light, the velocity of light, and the special theory of relativity are also examined in this part. The second part is devoted to quantum optics, specifically discussing the classical molecular theory of optical p

  20. Design and realization of sort manipulator of crystal-angle sort machine

    Science.gov (United States)

    Wang, Ming-shun; Chen, Shu-ping; Guan, Shou-ping; Zhang, Yao-wei

    2005-12-01

    It is a current tendency of development in automation technology to replace manpower with manipulators in working places where dangerous, harmful, heavy or repetitive work is involved. The sort manipulator is installed in a crystal-angle sort machine to take the place of manpower, and engaged in unloading and sorting work. It is the outcome of combing together mechanism, electric transmission, and pneumatic element and micro-controller control. The step motor makes the sort manipulator operate precisely. The pneumatic elements make the sort manipulator be cleverer. Micro-controller's software bestows some simple artificial intelligence on the sort manipulator, so that it can precisely repeat its unloading and sorting work. The combination of manipulator's zero position and step motor counting control puts an end to accumulating error in long time operation. A sort manipulator's design in the practice engineering has been proved to be correct and reliable.

  1. Enhancement of Selection, Bubble and Insertion Sorting Algorithm

    OpenAIRE

    Muhammad Farooq Umar; Ehsan Ullah Munir; Shafqat Ali Shad; Muhammad Wasif Nisar

    2014-01-01

    In everyday life there is a large amount of data to arrange because sorting removes any ambiguities and make the data analysis and data processing very easy, efficient and provides with cost less effort. In this study a set of improved sorting algorithms are proposed which gives better performance and design idea. In this study five new sorting algorithms (Bi-directional Selection Sort, Bi-directional bubble sort, MIDBiDirectional Selection Sort, MIDBidirectional bubble sort and linear insert...

  2. Algorithm 426 : Merge sort algorithm [M1

    NARCIS (Netherlands)

    Bron, C.

    1972-01-01

    Sorting by means of a two-way merge has a reputation of requiring a clerically complicated and cumbersome program. This ALGOL 60 procedure demonstrates that, using recursion, an elegant and efficient algorithm can be designed, the correctness of which is easily proved [2]. Sorting n objects gives

  3. Engineering a Cache-Oblivious Sorting Algorithm

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Fagerberg, Rolf; Vinther, Kristoffer

    2007-01-01

    This paper is an algorithmic engineering study of cache-oblivious sorting. We investigate by empirical methods a number of implementation issues and parameter choices for the cache-oblivious sorting algorithm Lazy Funnelsort, and compare the final algorithm with Quicksort, the established standard...

  4. Heuristic framework for parallel sorting computations | Nwanze ...

    African Journals Online (AJOL)

    Parallel sorting techniques have become of practical interest with the advent of new multiprocessor architectures. The decreasing cost of these processors will probably in the future, make the solutions that are derived thereof to be more appealing. Efficient algorithms for sorting scheme that are encountered in a number of ...

  5. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Ninth Edition Optics: Ninth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommen

  6. Data parallel sorting for particle simulation

    Science.gov (United States)

    Dagum, Leonardo

    1992-01-01

    Sorting on a parallel architecture is a communications intensive event which can incur a high penalty in applications where it is required. In the case of particle simulation, only integer sorting is necessary, and sequential implementations easily attain the minimum performance bound of O (N) for N particles. Parallel implementations, however, have to cope with the parallel sorting problem which, in addition to incurring a heavy communications cost, can make the minimun performance bound difficult to attain. This paper demonstrates how the sorting problem in a particle simulation can be reduced to a merging problem, and describes an efficient data parallel algorithm to solve this merging problem in a particle simulation. The new algorithm is shown to be optimal under conditions usual for particle simulation, and its fieldwise implementation on the Connection Machine is analyzed in detail. The new algorithm is about four times faster than a fieldwise implementation of radix sort on the Connection Machine.

  7. Data Sorting Using Graphics Processing Units

    Directory of Open Access Journals (Sweden)

    M. J. Mišić

    2012-06-01

    Full Text Available Graphics processing units (GPUs have been increasingly used for general-purpose computation in recent years. The GPU accelerated applications are found in both scientific and commercial domains. Sorting is considered as one of the very important operations in many applications, so its efficient implementation is essential for the overall application performance. This paper represents an effort to analyze and evaluate the implementations of the representative sorting algorithms on the graphics processing units. Three sorting algorithms (Quicksort, Merge sort, and Radix sort were evaluated on the Compute Unified Device Architecture (CUDA platform that is used to execute applications on NVIDIA graphics processing units. Algorithms were tested and evaluated using an automated test environment with input datasets of different characteristics. Finally, the results of this analysis are briefly discussed.

  8. Big Five Measurement via Q-Sort

    Directory of Open Access Journals (Sweden)

    Chris D. Fluckinger

    2014-08-01

    Full Text Available Socially desirable responding presents a difficult challenge in measuring personality. I tested whether a partially ipsative measure—a normatively scored Q-sort containing traditional Big Five items—would produce personality scores indicative of less socially desirable responding compared with Likert-based measures. Across both instructions to respond honestly and in the context of applying for a job, the Q-sort produced lower mean scores, lower intercorrelations between dimensions, and similar validity in predicting supervisor performance ratings to Likert. In addition, the Q-sort produced a more orthogonal structure (but not fully orthogonal when modeled at the latent level. These results indicate that the Q-sort method did constrain socially desirable responding. Researchers and practitioners should consider Big Five measurement via Q-sort for contexts in which high socially desirable responding is expected.

  9. Immunoliposome-mediated delivery of neomycin phosphotransferase for the lineage-specific selection of differentiated/committed stem cell progenies: potential advantages over transfection with marker genes, fluorescence-activated and magnetic affinity cell-sorting.

    Science.gov (United States)

    Heng, Boon Chin; Cao, Tong

    2005-01-01

    A major challenge in the therapeutic application of stem cells in regenerative medicine is the lineage-specific selection of their committed/differentiated progenies for transplantation. This is necessary to avoid engraftment of undesired lineages at the transplantation site, i.e. fibroblastic scar tissue, as well as to enhance the efficacy of transplantation therapy. Commonly used techniques for lineage-specific selection of committed/differentiated stem cell progenies include marker gene transfection, fluorescence-activated (FACS) and magnetic-affinity (MACS) cell-sorting. Nevertheless, these have their disadvantages for therapeutic applications. Marker gene transfection invariably leads to permanent genetic modification of stem cells, which in turn limits their use in human clinical therapy due to overwhelming ethical and safety concerns. FACS requires expensive instrumentation and highly-skilled personnel, and is unsuited for handling bulk quantities of cells that would almost certainly be required for transplantation therapy. MACS is a cheaper alternative, but the level of purity attained is also reduced. A possible novel approach that has yet to be investigated is immunoliposome-mediated delivery of neomycin phosphotranferase (NPT) for lineage-specific selection of stem cell progenies. This would avoid permanent genetic modification to the cell, unlike recombinant NPT expression linked to activation of specific promoter sequences. Moreover, it could potentially provide a much more practical and cost-effective alternative for handling bulk quantities of cells that would be required for transplantation therapy, as compared to FACS or MACS. As such, this alternative approach needs to be rigorously investigated, in view of its potentially useful applications in stem cell therapeutics.

  10. Optical Breath Gas Sensor for Extravehicular Activity Application

    Science.gov (United States)

    Wood, William R.; Casias, Miguel E.; Vakhtin, Andrei B.; Pilgrim, Jeffrey S.; Chullen, Cinda; Falconi, Eric A.; McMillin, Summer

    2013-01-01

    The function of the infrared gas transducer used during extravehicular activity in the current space suit is to measure and report the concentration of carbon dioxide (CO2) in the ventilation loop. The next generation portable life support system (PLSS) requires next generation CO2 sensing technology with performance beyond that presently in use on the Space Shuttle/International Space Station extravehicular mobility unit (EMU). Accommodation within space suits demands that optical sensors meet stringent size, weight, and power requirements. A laser diode spectrometer based on wavelength modulation spectroscopy is being developed for this purpose by Vista Photonics, Inc. Two prototype devices were delivered to NASA Johnson Space Center (JSC) in September 2011. The sensors incorporate a laser diode-based CO2 channel that also includes an incidental water vapor (humidity) measurement and a separate oxygen channel using a vertical cavity surface emitting laser. Both prototypes are controlled digitally with a field-programmable gate array/microcontroller architecture. The present development extends and upgrades the earlier hardware to the Advanced PLSS 2.0 test article being constructed and tested at JSC. Various improvements to the electronics and gas sampling are being advanced by this project. The combination of low power electronics with the performance of a long wavelength laser spectrometer enables multi-gas sensors with significantly increased performance over that presently offered in the EMU.

  11. Efficient sorting of Bessel beams

    CSIR Research Space (South Africa)

    Dudley, Angela L

    2013-01-01

    Full Text Available of both freeform optics. An initial radial spacing of ?kr will result in a vertical spread in the signal plane, ?u, given by ,2 r r kdu kpi ?? = (5) and thus the minimum resolvable feature, ?, constrains the resolvable wavevectors to 2 .r rk kd...

  12. The fiber-optic imaging and manipulation of neural activity during animal behavior.

    Science.gov (United States)

    Miyamoto, Daisuke; Murayama, Masanori

    2016-02-01

    Recent progress with optogenetic probes for imaging and manipulating neural activity has further increased the relevance of fiber-optic systems for neural circuitry research. Optical fibers, which bi-directionally transmit light between separate sites (even at a distance of several meters), can be used for either optical imaging or manipulating neural activity relevant to behavioral circuitry mechanisms. The method's flexibility and the specifications of the light structure are well suited for following the behavior of freely moving animals. Furthermore, thin optical fibers allow researchers to monitor neural activity from not only the cortical surface but also deep brain regions, including the hippocampus and amygdala. Such regions are difficult to target with two-photon microscopes. Optogenetic manipulation of neural activity with an optical fiber has the advantage of being selective for both cell-types and projections as compared to conventional electrophysiological brain tissue stimulation. It is difficult to extract any data regarding changes in neural activity solely from a fiber-optic manipulation device; however, the readout of data is made possible by combining manipulation with electrophysiological recording, or the simultaneous application of optical imaging and manipulation using a bundle-fiber. The present review introduces recent progress in fiber-optic imaging and manipulation methods, while also discussing fiber-optic system designs that are suitable for a given experimental protocol. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  13. IMPLEMENTATION OF SERIAL AND PARALLEL BUBBLE SORT ON FPGA

    Directory of Open Access Journals (Sweden)

    Dwi Marhaendro Jati Purnomo

    2016-06-01

    Full Text Available Sorting is common process in computational world. Its utilization are on many fields from research to industry. There are many sorting algorithm in nowadays. One of the simplest yet powerful is bubble sort. In this study, bubble sort is implemented on FPGA. The implementation was taken on serial and parallel approach. Serial and parallel bubble sort then compared by means of its memory, execution time, and utility which comprises slices and LUTs. The experiments show that serial bubble sort required smaller memory as well as utility compared to parallel bubble sort. Meanwhile, parallel bubble sort performed faster than serial bubble sort

  14. An Unsupervised Online Spike-Sorting Framework.

    Science.gov (United States)

    Knieling, Simeon; Sridharan, Kousik S; Belardinelli, Paolo; Naros, Georgios; Weiss, Daniel; Mormann, Florian; Gharabaghi, Alireza

    2016-08-01

    Extracellular neuronal microelectrode recordings can include action potentials from multiple neurons. To separate spikes from different neurons, they can be sorted according to their shape, a procedure referred to as spike-sorting. Several algorithms have been reported to solve this task. However, when clustering outcomes are unsatisfactory, most of them are difficult to adjust to achieve the desired results. We present an online spike-sorting framework that uses feature normalization and weighting to maximize the distinctiveness between different spike shapes. Furthermore, multiple criteria are applied to either facilitate or prevent cluster fusion, thereby enabling experimenters to fine-tune the sorting process. We compare our method to established unsupervised offline (Wave_Clus (WC)) and online (OSort (OS)) algorithms by examining their performance in sorting various test datasets using two different scoring systems (AMI and the Adamos metric). Furthermore, we evaluate sorting capabilities on intra-operative recordings using established quality metrics. Compared to WC and OS, our algorithm achieved comparable or higher scores on average and produced more convincing sorting results for intra-operative datasets. Thus, the presented framework is suitable for both online and offline analysis and could substantially improve the quality of microelectrode-based data evaluation for research and clinical application.

  15. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Eighth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommended for engineering st

  16. Experience and problems of the automated measuring and sorting of sealed radiation sources

    International Nuclear Information System (INIS)

    Shmidt, G.

    1979-01-01

    It has been shown that with the help of a serial device for samples changing and a mini-computer with a suitable software it is possible to organize the radioactivity measuring and sorting of sealed gamma-sources with activity in the microcuri region. Application of the computer permits to rise accuracy of the data on the radiation sources radioactivity, sorted according to the preset activity level groups and, in the casa of necessity, to perform the activity measurements with lower error. The method listed, gives the working-time economy of nearly 4 hours in measuring and sorting of some 500 sealed radiation sources [ru

  17. Optical Counterparts of Undetermined Type γ-Ray Active Galactic

    Indian Academy of Sciences (India)

    2015-09-30

    Sep 30, 2015 ... of this optical spectroscopic analysis is to identify the AGN class for the source asso- .... absorption lines of an old stellar population, typical of ellipticals. .... AGNs is a fundamental science case for instruments designed to ...

  18. Active composite waveguides with a suppressed competition of optical modes

    International Nuclear Information System (INIS)

    Vysotskii, D V; Elkin, N N; Napartovich, A P

    2008-01-01

    The possibilities of separating the fundamental optical mode in composite waveguides by selecting the structure of amplifying regions are analysed. Conditions are presented under which the fundamental mode preserves the highest gain at any saturation. (letters)

  19. Accurate measurement of the optical activity of alanine crystals and the determination of their absolute chirality

    Science.gov (United States)

    Ishikawa, Kazuhiko; Terasawa, Yukana; Tanaka, Masahito; Asahi, Toru

    2017-05-01

    Wavelength dependence measurements of the chiroptical properties in alanine crystals have so far been unsuccessful using conventional spectroscopic techniques. We describe our attempts to measure the wavelength dependence of the optical activity in L- and D-alanine crystals along each crystallographic axis, and to determine the absolute chirality of alanine crystals by correlating the absolute structure to the optical activity using an x-ray diffractometer and a generalized high accuracy universal polarimeter. We have succeeded in accurately measuring the optical rotatory dispersion in the direction, which shows that the optical rotation of the D-alanine crystal is dextrorotatory and that of the L-alanine crystal is laevorotatory, thereby determining the absolute chirality. Furthermore, comparison with the optical activity in solution shows that the optical activity in alanine crystals is different not only in value, but also in the sign. These results have led us to conclude that the optical rotatory power in the crystalline state should not be simply the summation of molecular optical rotatory power values. We propose the necessity of a theory, which contains the contribution of molecular interactions within the crystal, in order to calculate the optical rotatory power of the crystalline state.

  20. The Q sort theory and technique.

    Science.gov (United States)

    Nyatanga, L

    1989-10-01

    This paper is based on the author's experience of using the Q sort technique with BA Social Sciences (BASS) students, and the community psychiatric nursing (CPN, ENB No 811 course). The paper focuses on two main issues: 1. The theoretical assumptions underpinning the Q Sort technique. Carl Rogers' self theory and some of the values of humanistic psychology are summarised. 2. The actual technique procedure and meaning of results are highlighted. As the Q Sort technique is potentially useful in a variety of sittings some of which are listed in this paper, the emphasis has deliberately been placed in understanding the theoretical underpinning and the operationalisation (sensitive interpretation) of the theory to practice.

  1. Development of sorting system control using LABVIEW

    International Nuclear Information System (INIS)

    Azraf Azman; Mohd Arif Hamzah; Noriah Mod Ali; John Konsoh; Mohd Idris Taib; Maslina Mohd Ibrahim; Nor Arymaswati Abdullah; Abu Bakar Mhd Ghazali

    2005-01-01

    The development of the Personnel Dosimeter Sorting System, proposed by the Secondary Standard Dosimetry Laboratory (SSDL) is to enhance the system or work flow in preparing the personnel dosimeter. The main objective of the system is to reduce stamping error, time and cost. The Personnel Dosimeter Sorting System is a semi-automatic system with an interfacing method using the Advantec 32 bit PCI interface card of 64 digital input and output. The system is integrated with the Labview version 7.1 programming language to control the sorting system and operation. (Author)

  2. On Sorting Genomes with DCJ and Indels

    Science.gov (United States)

    Braga, Marília D. V.

    A previous work of Braga, Willing and Stoye compared two genomes with unequal content, but without duplications, and presented a new linear time algorithm to compute the genomic distance, considering double cut and join (DCJ) operations, insertions and deletions. Here we derive from this approach an algorithm to sort one genome into another one also using DCJ, insertions and deletions. The optimal sorting scenarios can have different compositions and we compare two types of sorting scenarios: one that maximizes and one that minimizes the number of DCJ operations with respect to the number of insertions and deletions.

  3. Towards understanding and managing the learning process in mail sorting.

    Science.gov (United States)

    Berglund, M; Karltun, A

    2012-01-01

    This paper was based on case study research at the Swedish Mail Service Division and it addresses learning time to sort mail at new districts and means to support the learning process on an individual as well as organizational level. The study population consisted of 46 postmen and one team leader in the Swedish Mail Service Division. Data were collected through measurements of time for mail sorting, interviews and a focus group. The study showed that learning to sort mail was a much more complex process and took more time than expected by management. Means to support the learning process included clarification of the relationship between sorting and the topology of the district, a good work environment, increased support from colleagues and management, and a thorough introduction for new postmen. The identified means to support the learning process require an integration of human, technological and organizational aspects. The study further showed that increased operations flexibility cannot be reinforced without a systems perspective and thorough knowledge about real work activities and that ergonomists can aid businesses to acquire this knowledge.

  4. Support for designing waste sorting systems: A mini review.

    Science.gov (United States)

    Rousta, Kamran; Ordoñez, Isabel; Bolton, Kim; Dahlén, Lisa

    2017-11-01

    This article presents a mini review of research aimed at understanding material recovery from municipal solid waste. It focuses on two areas, waste sorting behaviour and collection systems, so that research on the link between these areas could be identified and evaluated. The main results presented and the methods used in the articles are categorised and appraised. The mini review reveals that most of the work that offered design guidelines for waste management systems was based on optimising technical aspects only. In contrast, most of the work that focused on user involvement did not consider developing the technical aspects of the system, but was limited to studies of user behaviour. The only clear consensus among the articles that link user involvement with the technical system is that convenient waste collection infrastructure is crucial for supporting source separation. This mini review reveals that even though the connection between sorting behaviour and technical infrastructure has been explored and described in some articles, there is still a gap when using this knowledge to design waste sorting systems. Future research in this field would benefit from being multidisciplinary and from using complementary methods, so that holistic solutions for material recirculation can be identified. It would be beneficial to actively involve users when developing sorting infrastructures, to be sure to provide a waste management system that will be properly used by them.

  5. Pengembangan Algoritma Pengurutan SMS (Scan, Move, And Sort)

    OpenAIRE

    Lubis, Denni Aprilsyah

    2015-01-01

    Sorting has been a profound area for the algorithmic researchers. And many resources are invested to suggest a more working sorting algorithm. For this purpose many existing sorting algorithms were observed in terms of the efficiency of the algorithmic complexity. Efficient sorting is important to optimize the use of other algorithms that require sorted lists to work correctly. sorting has been considered as a fundamental problem in the study of algorithms that due to many reas...

  6. Implementation of Serial and Parallel Bubble Sort on Fpga

    OpenAIRE

    Purnomo, Dwi Marhaendro Jati; Arinaldi, Ahmad; Priyantini, Dwi Teguh; Wibisono, Ari; Febrian, Andreas

    2016-01-01

    Sorting is common process in computational world. Its utilization are on many fields from research to industry. There are many sorting algorithm in nowadays. One of the simplest yet powerful is bubble sort. In this study, bubble sort is implemented on FPGA. The implementation was taken on serial and parallel approach. Serial and parallel bubble sort then compared by means of its memory, execution time, and utility which comprises slices and LUTs. The experiments show that serial bubble sort r...

  7. Optical rectification, circular photogalvanic effect, and five-wave mixing in optically active liquids

    Science.gov (United States)

    Koroteev, Nikolai I.

    1996-05-01

    A phenomenological analysis is carried out of novel nonlinear optical processes taking place in macroscopically noncentrosymmetric isotropic solutions of chiral (lift-ring mirror asymmetric) macromolecules, which are the primary elements of living organisms and their metabolic products. Among the most interesting and potentially useful for spectroscopic purposes are: optical rectification/photogalvanic effects consisting in electrostatic field/direct electrical current generation in such liquids under irradiation with the intense circularly polarized laser beam and the five-wave mixing phase-matched process of BioCARS to selectively record, background-free, vibrational spectra of chiral molecules.

  8. NeatSort - A practical adaptive algorithm

    OpenAIRE

    La Rocca, Marcello; Cantone, Domenico

    2014-01-01

    We present a new adaptive sorting algorithm which is optimal for most disorder metrics and, more important, has a simple and quick implementation. On input $X$, our algorithm has a theoretical $\\Omega (|X|)$ lower bound and a $\\mathcal{O}(|X|\\log|X|)$ upper bound, exhibiting amazing adaptive properties which makes it run closer to its lower bound as disorder (computed on different metrics) diminishes. From a practical point of view, \\textit{NeatSort} has proven itself competitive with (and of...

  9. Automatic spike sorting using tuning information.

    Science.gov (United States)

    Ventura, Valérie

    2009-09-01

    Current spike sorting methods focus on clustering neurons' characteristic spike waveforms. The resulting spike-sorted data are typically used to estimate how covariates of interest modulate the firing rates of neurons. However, when these covariates do modulate the firing rates, they provide information about spikes' identities, which thus far have been ignored for the purpose of spike sorting. This letter describes a novel approach to spike sorting, which incorporates both waveform information and tuning information obtained from the modulation of firing rates. Because it efficiently uses all the available information, this spike sorter yields lower spike misclassification rates than traditional automatic spike sorters. This theoretical result is verified empirically on several examples. The proposed method does not require additional assumptions; only its implementation is different. It essentially consists of performing spike sorting and tuning estimation simultaneously rather than sequentially, as is currently done. We used an expectation-maximization maximum likelihood algorithm to implement the new spike sorter. We present the general form of this algorithm and provide a detailed implementable version under the assumptions that neurons are independent and spike according to Poisson processes. Finally, we uncover a systematic flaw of spike sorting based on waveform information only.

  10. The solution space of sorting by DCJ.

    Science.gov (United States)

    Braga, Marília D V; Stoye, Jens

    2010-09-01

    In genome rearrangements, the double cut and join (DCJ) operation, introduced by Yancopoulos et al. in 2005, allows one to represent most rearrangement events that could happen in multichromosomal genomes, such as inversions, translocations, fusions, and fissions. No restriction on the genome structure considering linear and circular chromosomes is imposed. An advantage of this general model is that it leads to considerable algorithmic simplifications compared to other genome rearrangement models. Recently, several works concerning the DCJ operation have been published, and in particular, an algorithm was proposed to find an optimal DCJ sequence for sorting one genome into another one. Here we study the solution space of this problem and give an easy-to-compute formula that corresponds to the exact number of optimal DCJ sorting sequences for a particular subset of instances of the problem. We also give an algorithm to count the number of optimal sorting sequences for any instance of the problem. Another interesting result is the demonstration of the possibility of obtaining one optimal sorting sequence by properly replacing any pair of consecutive operations in another optimal sequence. As a consequence, any optimal sorting sequence can be obtained from one other by applying such replacements successively, but the problem of finding the shortest number of replacements between two sorting sequences is still open.

  11. Optical gain of LaF3:Nd nanoparticle doped polymers for active integrated optical devices

    NARCIS (Netherlands)

    Stouwdam, J.W.; Klunder, D.J.W.; Borreman, A.; Diemeer, Mart; Worhoff, Kerstin; Driessen, A.; de Ridder, R.M.; de Ridder, R.M; Altena, G; Altena, G.; Geuzebroek, D.H.; Dekker, R; Dekker, R.

    2003-01-01

    We report on rare earth doped LaF3 nanoparticles dispersed in PMMA and SU-8 photosensitive polymers. We observed optical gain after we applied these materials for waveguides. Experimental results on various samples will be discussed. We theoretically discuss the improvements that can be obtained and

  12. Analysis technique for controlling system wavefront error with active/adaptive optics

    Science.gov (United States)

    Genberg, Victor L.; Michels, Gregory J.

    2017-08-01

    The ultimate goal of an active mirror system is to control system level wavefront error (WFE). In the past, the use of this technique was limited by the difficulty of obtaining a linear optics model. In this paper, an automated method for controlling system level WFE using a linear optics model is presented. An error estimate is included in the analysis output for both surface error disturbance fitting and actuator influence function fitting. To control adaptive optics, the technique has been extended to write system WFE in state space matrix form. The technique is demonstrated by example with SigFit, a commercially available tool integrating mechanical analysis with optical analysis.

  13. Nano-optical conveyor belt, part I: Theory.

    Science.gov (United States)

    Hansen, Paul; Zheng, Yuxin; Ryan, Jason; Hesselink, Lambertus

    2014-06-11

    We propose a method for peristaltic transport of nanoparticles using the optical force field over a nanostructured surface. Nanostructures may be designed to produce strong near-field hot spots when illuminated. The hot spots function as optical traps, separately addressable by their resonant wavelengths and polarizations. By activating closely packed traps sequentially, nanoparticles may be handed off between adjacent traps in a peristaltic fashion. A linear repeating structure of three separately addressable traps forms a "nano-optical conveyor belt"; a unit cell with four separately addressable traps permits controlled peristaltic transport in the plane. Using specifically designed activation sequences allows particle sorting.

  14. Recent optical activity of the blazar OT 355

    Science.gov (United States)

    Bachev, R.; Kurtenkov, A.; Nikolov, Y.; Spassov, B.; Boeva, S.; Latev, G.; Dimitrova, R. V. Munoz

    2017-06-01

    The Flat Spectrum Radio Quasar OT 355 (also known as 7C 173240.70+385949.00, z=0.975) was typically observed to be in the optical between 16th and 21th magnitude (CRTS, http://nesssi.cacr.caltech.edu/catalina/20011332/113321380764100137p.html).

  15. Active control of electromagnetic radiation through an enhanced thermo-optic effect

    Science.gov (United States)

    Sheng, Chong; Liu, Hui; Zhu, Shining; Genov, Dentcho A.

    2015-01-01

    The control of electromagnetic radiation in transformation optical metamaterials brings the development of vast variety of optical devices. Of a particular importance is the possibility to control the propagation of light with light. In this work, we use a structured planar cavity to enhance the thermo-optic effect in a transformation optical waveguide. In the process, a control laser produces apparent inhomogeneous refractive index change inside the waveguides. The trajectory of a second probe laser beam is then continuously tuned in the experiment. The experimental results agree well with the developed theory. The reported method can provide a new approach toward development of transformation optical devices where active all-optical control of the impinging light can be achieved. PMID:25746689

  16. Single Molecule Instrument for Surface Enhanced Raman Optical Activity of Biomolecules, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Stereochemistry is an essential element of our organic life. Only certain enantiomers are useful as drugs for the human body. Raman optical activity (ROA) provides...

  17. Single Molecule Instrument for Surface Enhanced Raman Optical Activity of Biomolecules, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Stereochemistry is an essential element of our organic life. Only certain enantiomers are useful as drugs for the human body. Raman Optical Activity (ROA) and...

  18. Strong Broadband Terahertz Optical Activity through Control of the Blaschke Phase with Chiral Metasurfaces

    Science.gov (United States)

    Cole, Michael A.; Chen, Wen-chen; Liu, Mingkai; Kruk, Sergey S.; Padilla, Willie J.; Shadrivov, Ilya V.; Powell, David A.

    2017-07-01

    We demonstrate terahertz chiral metamaterials that achieve resonant transmission and strong optical activity. This response is realized in a metasurface coupled to its Babinet complement, with additional twist. Uniquely, the optical activity achieved in this type of metamaterial is weakly dispersive around the resonant transmission maxima, but it can be highly dispersive around the transmission minima. It has recently been shown that this unique optical activity response is closely related to zeros in the transmission spectra of circular polarizations through the Kramers-Kronig relations and strong resonant features in the optical activity spectrum corresponding to the Blaschke phase terms. Here we demonstrate how modifying the meta-atom geometry greatly affects the location and magnitude of these Blaschke phase terms. We study three different meta-atoms, which are variations on the simple cross structure. Their responses are measured using terahertz time-domain spectroscopy and analyzed via numerical simulations.

  19. Coherent phonon optics in a chip with an electrically controlled active device.

    Science.gov (United States)

    Poyser, Caroline L; Akimov, Andrey V; Campion, Richard P; Kent, Anthony J

    2015-02-05

    Phonon optics concerns operations with high-frequency acoustic waves in solid media in a similar way to how traditional optics operates with the light beams (i.e. photons). Phonon optics experiments with coherent terahertz and sub-terahertz phonons promise a revolution in various technical applications related to high-frequency acoustics, imaging, and heat transport. Previously, phonon optics used passive methods for manipulations with propagating phonon beams that did not enable their external control. Here we fabricate a phononic chip, which includes a generator of coherent monochromatic phonons with frequency 378 GHz, a sensitive coherent phonon detector, and an active layer: a doped semiconductor superlattice, with electrical contacts, inserted into the phonon propagation path. In the experiments, we demonstrate the modulation of the coherent phonon flux by an external electrical bias applied to the active layer. Phonon optics using external control broadens the spectrum of prospective applications of phononics on the nanometer scale.

  20. Optical rotation and electron spin resonance of an electro-optically active polythiophene

    International Nuclear Information System (INIS)

    Goto, Hiromasa

    2010-01-01

    Graphical abstract: The electro-chiroptical polythiophene displays optical rotation at wavelengths corresponding to the doping band observable in the absorption spectra. The formation of polarons on the main-chain is confirmed by electron spin resonance measurements. - Abstract: A chiroptical polythiophene, is synthesized by electrolytic polymerization in a cholesteric liquid crystal electrolyte solution. The polymer displays a fingerprint texture similar to that of the cholesteric electrolyte solution. Upon electrochemical doping, the polymer displays optical rotation at wavelengths corresponding to the doping band observable in the absorption spectra. The formation of polarons on the main-chain is confirmed by electron spin resonance measurements. The results demonstrate the intermolecular chirality of polarons in this π-conjugated polymer, indicating continuum delocalized polarons are in a three-dimensional helical environment.

  1. Temperature dependent investigation on optically active process of higher-order bands in irradiated silicon

    International Nuclear Information System (INIS)

    Shi Yi; Nanjing Univ., JS; Wu Fengmei; Nanjing Univ., JS; Zheng Youdou; Nanjing Univ., JS; Suezawa, M.; Imai, M.; Sumino, K.

    1996-01-01

    Optically active processes of the higher-order bands (HOB) are investigated at different temperatures in fast neutron irradiated silicon using Fourier transform infrared absorption measurement. It is shown that the optically active process is nearly temperature independent below 80 K, the slow decay process remains up to a heating temperature of 180 K. The observations are analyzed in terms of the relaxation behavior of photoexcited carriers governed by fast neutron radiation induced defect clusters. (orig.)

  2. Integrated Active and Passive Polymer Optical Components with nm to mm Features

    DEFF Research Database (Denmark)

    Christiansen, Mads Brøkner; Schøler, Mikkel; Kristensen, Anders

    2007-01-01

    We present wafer-scale fabrication of integrated active and passive polymer optics with nm to mm features. First order DFB lasers, defined in dye doped SU-8 resist are integrated with SU-8 waveguides.......We present wafer-scale fabrication of integrated active and passive polymer optics with nm to mm features. First order DFB lasers, defined in dye doped SU-8 resist are integrated with SU-8 waveguides....

  3. Photo-induced optical activity in phase-change memory materials.

    Science.gov (United States)

    Borisenko, Konstantin B; Shanmugam, Janaki; Williams, Benjamin A O; Ewart, Paul; Gholipour, Behrad; Hewak, Daniel W; Hussain, Rohanah; Jávorfi, Tamás; Siligardi, Giuliano; Kirkland, Angus I

    2015-03-05

    We demonstrate that optical activity in amorphous isotropic thin films of pure Ge2Sb2Te5 and N-doped Ge2Sb2Te5N phase-change memory materials can be induced using rapid photo crystallisation with circularly polarised laser light. The new anisotropic phase transition has been confirmed by circular dichroism measurements. This opens up the possibility of controlled induction of optical activity at the nanosecond time scale for exploitation in a new generation of high-density optical memory, fast chiroptical switches and chiral metamaterials.

  4. Optical activity of oriented molecular systems in terms of the magnetoelectric tensor of gyrotropy

    International Nuclear Information System (INIS)

    Arteaga, Oriol

    2014-01-01

    The optical activity of oriented molecular systems is investigated using bianisotropic material constitutives for Maxwell's equations. It is shown that the circular birefringence and circular dichroism for an oriented system can be conveniently expressed in terms of the two components of the symmetric magnetoelectric tensor of gyrotropy that are perpendicular to this direction of light propagation. This description establishes a direct link between the optical activity measured at a certain direction and the tensors that describe the oscillating electric and magnetic dipole and electric quadrupole moments induced by the optical wave. (paper)

  5. Enzyme activity assays within microstructured optical fibers enabled by automated alignment.

    Science.gov (United States)

    Warren-Smith, Stephen C; Nie, Guiying; Schartner, Erik P; Salamonsen, Lois A; Monro, Tanya M

    2012-12-01

    A fluorescence-based enzyme activity assay has been demonstrated within a small-core microstructured optical fiber (MOF) for the first time. To achieve this, a reflection-based automated alignment system has been developed, which uses feedback and piezoelectric actuators to maintain optical alignment. The auto-alignment system provides optical stability for the time required to perform an activity assay. The chosen assay is based on the enzyme proprotein convertase 5/6 (PC6) and has important applications in women's health.

  6. Minimal-effort planning of active alignment processes for beam-shaping optics

    Science.gov (United States)

    Haag, Sebastian; Schranner, Matthias; Müller, Tobias; Zontar, Daniel; Schlette, Christian; Losch, Daniel; Brecher, Christian; Roßmann, Jürgen

    2015-03-01

    In science and industry, the alignment of beam-shaping optics is usually a manual procedure. Many industrial applications utilizing beam-shaping optical systems require more scalable production solutions and therefore effort has been invested in research regarding the automation of optics assembly. In previous works, the authors and other researchers have proven the feasibility of automated alignment of beam-shaping optics such as collimation lenses or homogenization optics. Nevertheless, the planning efforts as well as additional knowledge from the fields of automation and control required for such alignment processes are immense. This paper presents a novel approach of planning active alignment processes of beam-shaping optics with the focus of minimizing the planning efforts for active alignment. The approach utilizes optical simulation and the genetic programming paradigm from computer science for automatically extracting features from a simulated data basis with a high correlation coefficient regarding the individual degrees of freedom of alignment. The strategy is capable of finding active alignment strategies that can be executed by an automated assembly system. The paper presents a tool making the algorithm available to end-users and it discusses the results of planning the active alignment of the well-known assembly of a fast-axis collimator. The paper concludes with an outlook on the transferability to other use cases such as application specific intensity distributions which will benefit from reduced planning efforts.

  7. Nonlinear optical activity in Bridgman growth layered compounds

    Energy Technology Data Exchange (ETDEWEB)

    Miah, M.I., E-mail: m.miah@griffith.edu.au [Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, Brisbane, QLD 4111 (Australia); Biomolecular and Physical Sciences, Griffith University, Nathan, Brisbane, QLD 4111 (Australia); Department of Physics, University of Chittagong, Chittagong 4331 (Bangladesh)

    2010-02-15

    Layered semiconductor compound CdI{sub 2} has been grown with the Bridgman technique and studied by nonlinear transmittance spectroscopy. The optical absorption in CdI{sub 2} shows a nonlinear transmission of the incident laser power (P{sub 0}) within a lower power limit. The transmission, however, is found to saturate at high powers, giving a clamped output. The value of the incident power (P{sub 0C}) at which clamping starts is also found to depend on the crystal temperature (T{sub L}). The values of P{sub OC} ranges from 55 to 65 MW cm{sup -2} for T{sub L} = 4.2-180 K. The dynamic range (D{sub R}) as a function of T{sub L} is calculated and the values are found to range from D{sub R} = 2 to 1.6. The optical limiting mechanisms are discussed. The two-photon absorption (TPA) coefficient ({beta}) of the optical nonlinear process in CdI{sub 2} is estimated. The values are found to be within a range from {beta} = 47 to 25 cm GW{sup -1} and be decreasing with increasing T{sub L}. As expected for the TPA process, the experimental data within a certain range follows the linear relation: log (P{sub 0}/P{sub T}) = A{sub G} + {Omega}(P{sub 0} - P{sub T}), where P{sub T} is the transmitted power, A{sub G} is the absorbance of the ground state and {Omega} is a constant depending on the absorption cross-section and the relaxation time. The values of A{sub G} and {Omega} estimated from the fits to the measured data vary with T{sub L}. The findings resulting from this investigation might have potential applications in optical sensors protection.

  8. Optical Design of COATLI: A Diffraction-Limited Visible Imager with Fast Guiding and Active Optics Correction

    Science.gov (United States)

    Fuentes-Fernández, J.; Cuevas, S.; Watson, A. M.

    2018-04-01

    We present the optical design of COATLI, a two channel visible imager for a comercial 50 cm robotic telescope. COATLI will deliver diffraction-limited images (approximately 0.3 arcsec FWHM) in the riz bands, inside a 4.2 arcmin field, and seeing limited images (approximately 0.6 arcsec FWHM) in the B and g bands, inside a 5 arcmin field, by means of a tip-tilt mirror for fast guiding, and a deformable mirror for active optics, both located on two optically transferred pupil planes. The optical design is based on two collimator-camera systems plus a pupil transfer relay, using achromatic doublets of CaF2 and S-FTM16 and one triplet of N-BK7 and CaF2. We discuss the effciency, tolerancing, thermal behavior and ghosts. COATLI will be installed at the Observatorio Astronómico Nacional in Sierra San Pedro Mártir, Baja California, Mexico, in 2018.

  9. Comparison of spike-sorting algorithms for future hardware implementation.

    Science.gov (United States)

    Gibson, Sarah; Judy, Jack W; Markovic, Dejan

    2008-01-01

    Applications such as brain-machine interfaces require hardware spike sorting in order to (1) obtain single-unit activity and (2) perform data reduction for wireless transmission of data. Such systems must be low-power, low-area, high-accuracy, automatic, and able to operate in real time. Several detection and feature extraction algorithms for spike sorting are described briefly and evaluated in terms of accuracy versus computational complexity. The nonlinear energy operator method is chosen as the optimal spike detection algorithm, being most robust over noise and relatively simple. The discrete derivatives method [1] is chosen as the optimal feature extraction method, maintaining high accuracy across SNRs with a complexity orders of magnitude less than that of traditional methods such as PCA.

  10. A Success of Some Sort

    NARCIS (Netherlands)

    Venot, J.P.

    2016-01-01

    This paper explains the processes behind the framing of drip irrigation as a promising technology to address current poverty and environmental challenges in the developing world. I draw from critical development and science and technology studies and highlight that this imagery has been actively

  11. Sorting Potatoes for Miss Bonner.

    Science.gov (United States)

    Herreid, Clyde Freeman

    1998-01-01

    Discusses the basis of a classification scheme for types of case studies. Four major classification headings are identified: (1) individual assignment; (2) lecture; (3) discussion; and (4) small group activities. Describes each heading from the point of view of several teaching methods. (DDR)

  12. Fruit Sorting Using Fuzzy Logic Techniques

    Science.gov (United States)

    Elamvazuthi, Irraivan; Sinnadurai, Rajendran; Aftab Ahmed Khan, Mohamed Khan; Vasant, Pandian

    2009-08-01

    Fruit and vegetables market is getting highly selective, requiring their suppliers to distribute the goods according to very strict standards of quality and presentation. In the last years, a number of fruit sorting and grading systems have appeared to fulfill the needs of the fruit processing industry. However, most of them are overly complex and too costly for the small and medium scale industry (SMIs) in Malaysia. In order to address these shortcomings, a prototype machine was developed by integrating the fruit sorting, labeling and packing processes. To realise the prototype, many design issues were dealt with. Special attention is paid to the electronic weighing sub-system for measuring weight, and the opto-electronic sub-system for determining the height and width of the fruits. Specifically, this paper discusses the application of fuzzy logic techniques in the sorting process.

  13. Two optically active molybdenum disulfide quantum dots as tetracycline sensors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhuosen; Lin, Jintai [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Gao, Jinwei [Institute for Advanced Materials, Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006 (China); Wang, Qianming, E-mail: qmwang@scnu.edu.cn [Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Guangzhou Key Laboratory of Materials for Energy Conversion and Storage, 510006 (China)

    2016-08-01

    In this work, we use the hydrothermal method to develop two luminescent MoS{sub 2} quantum dots (QDs) from L-cysteine and glutathione as sulfur precursors. The special blue emissions give rise to an instantaneous determination of tetracycline (TC) through the quenching of its luminescence. The accessibility of the optical materials and recognition mechanism have been extensively studied. This strategy demonstrated that MoS{sub 2} could act as a new platform for anchoring bioactive species or particular functional moieties. - Highlights: • MoS{sub 2} nanostructures with water solubility have been fabricated. • Blue emission has been achieved. • It displays selective detection to tetracyclines in water.

  14. Actively stabilized optical fiber interferometry technique for online/in-process surface measurement

    International Nuclear Information System (INIS)

    Wang Kaiwei; Martin, Haydn; Jiang Xiangqian

    2008-01-01

    In this paper, we report the recent progress in optical-beam scanning fiber interferometry for potential online nanoscale surface measurement based on the previous research. It attempts to generate a robust and miniature measurement device for future development into a multiprobe array measurement system. In this research, both fiber-optic-interferometry and the wavelength-division-multiplexing techniques have been used, so that the optical probe and the optical interferometer are well spaced and fast surface scanning can be carried out, allowing flexibility for online measurement. In addition, this system provides a self-reference signal to stabilize the optical detection with high common-mode noise suppression by adopting an active phase tracking and stabilization technique. Low-frequency noise was significantly reduced compared with unstabilized result. The measurement of a sample surface shows an attained repeatability of 3.3 nm

  15. MODELING WORK OF SORTING STATION USING UML

    Directory of Open Access Journals (Sweden)

    O. V. Gorbova

    2014-12-01

    Full Text Available Purpose. The purpose of this paper is the construction of methods and models for the graphical representation process of sorting station, using the unified modeling language (UML. Methodology. Methods of graph theory, finite automata and the representation theory of queuing systems were used as the methods of investigation. A graphical representation of the process was implemented with using the Unified Modeling Language UML. The sorting station process representation is implemented as a state diagram and actions through a set of IBM Rational Rose. Graphs can show parallel operation of sorting station, the parallel existence and influence of objects process and the transition from one state to another. The IBM Rational Rose complex allows developing a diagram of work sequence of varying degrees of detailing. Findings. The study has developed a graphical representation method of the process of sorting station of different kind of complexity. All graphical representations are made using the UML. They are represented as a directed graph with the states. It is clear enough in the study of the subject area. Applying the methodology of the representation process, it allows becoming friendly with the work of any automation object very fast, and exploring the process during algorithms construction of sorting stations and other railway facilities. This model is implemented with using the Unified Modeling Language (UML using a combination of IBM Rational Rose. Originality. The representation process of sorting station was developed by means of the Unified Modeling Language (UML use. Methodology of representation process allows creating the directed graphs based on the order of execution of the works chain, objects and performers of these works. The UML allows visualizing, specifying, constructing and documenting, formalizing the representation process of sorting station and developing sequence diagrams of works of varying degrees of detail. Practical

  16. Software information sorting code 'PLUTO-R'

    International Nuclear Information System (INIS)

    Tsunematsu, Toshihide; Naraoka, Kenitsu; Adachi, Masao; Takeda, Tatsuoki

    1984-10-01

    A software information sorting code PLUTO-R is developed as one of the supporting codes of the TRITON system for the fusion plasma analysis. The objective of the PLUTO-R code is to sort reference materials of the codes in the TRITON code system. The easiness in the registration of information is especially pursued. As experience and skill in the data registration are not required, this code is usable for construction of general small-scale information system. This report gives an overall description and the user's manual of the PLUTO-R code. (author)

  17. Application of radix sorting in high energy physics experiment

    International Nuclear Information System (INIS)

    Chen Xuan; Gu Minhao; Zhu Kejun

    2012-01-01

    In the high energy physics experiments, there are always requirements to sort the large scale of experiment data. To meet the demand, this paper introduces one radix sorting algorithms, whose sub-sort is counting sorting and time complex is O (n), based on the characteristic of high energy physics experiment data that is marked by time stamp. This paper gives the description, analysis, implementation and experimental result of the sorting algorithms. (authors)

  18. Changing University Students' Alternative Conceptions of Optics by Active Learning

    Science.gov (United States)

    Hadžibegovic, Zalkida; Sliško, Josip

    2013-01-01

    Active learning is individual and group participation in effective activities such as in-class observing, writing, experimenting, discussion, solving problems, and talking about to-be-learned topics. Some instructors believe that active learning is impossible, or at least extremely difficult to achieve in large lecture sessions. Nevertheless, the…

  19. Monocular distance estimation from optic flow during active landing maneuvers

    International Nuclear Information System (INIS)

    Van Breugel, Floris; Morgansen, Kristi; Dickinson, Michael H

    2014-01-01

    Vision is arguably the most widely used sensor for position and velocity estimation in animals, and it is increasingly used in robotic systems as well. Many animals use stereopsis and object recognition in order to make a true estimate of distance. For a tiny insect such as a fruit fly or honeybee, however, these methods fall short. Instead, an insect must rely on calculations of optic flow, which can provide a measure of the ratio of velocity to distance, but not either parameter independently. Nevertheless, flies and other insects are adept at landing on a variety of substrates, a behavior that inherently requires some form of distance estimation in order to trigger distance-appropriate motor actions such as deceleration or leg extension. Previous studies have shown that these behaviors are indeed under visual control, raising the question: how does an insect estimate distance solely using optic flow? In this paper we use a nonlinear control theoretic approach to propose a solution for this problem. Our algorithm takes advantage of visually controlled landing trajectories that have been observed in flies and honeybees. Finally, we implement our algorithm, which we term dynamic peering, using a camera mounted to a linear stage to demonstrate its real-world feasibility. (paper)

  20. The in vivo activation of persistent nanophosphors for optical imaging of vascularization, tumours and grafted cells

    Science.gov (United States)

    Maldiney, Thomas; Bessière, Aurélie; Seguin, Johanne; Teston, Eliott; Sharma, Suchinder K.; Viana, Bruno; Bos, Adrie J. J.; Dorenbos, Pieter; Bessodes, Michel; Gourier, Didier; Scherman, Daniel; Richard, Cyrille

    2014-04-01

    Optical imaging for biological applications requires more sensitive tools. Near-infrared persistent luminescence nanoparticles enable highly sensitive in vivo optical detection and complete avoidance of tissue autofluorescence. However, the actual generation of persistent luminescence nanoparticles necessitates ex vivo activation before systemic administration, which prevents long-term imaging in living animals. Here, we introduce a new generation of optical nanoprobes, based on chromium-doped zinc gallate, whose persistent luminescence can be activated in vivo through living tissues using highly penetrating low-energy red photons. Surface functionalization of this photonic probe can be adjusted to favour multiple biomedical applications such as tumour targeting. Notably, we show that cells can endocytose these nanoparticles in vitro and that, after intravenous injection, we can track labelled cells in vivo and follow their biodistribution by a simple whole animal optical detection, opening new perspectives for cell therapy research and for a variety of diagnosis applications.

  1. Revisiting polarimetry near the isotropic point of an optically active, non-enantiomorphous, molecular crystal.

    Science.gov (United States)

    Martin, Alexander T; Tan, Melissa; Nichols, Shane M; Timothy, Emily; Kahr, Bart

    2018-07-01

    Accurate polarimetric measurements of the optical activity of crystals along low symmetry directions are facilitated by isotropic points, frequencies where dispersion curves of eigenrays cross and the linear birefringence disappears. We report here the optical properties and structure of achiral, uniaxial (point group D 2d ) potassium trihydrogen di-(cis-4-cyclohexene-1,2-dicarboxylate) dihydrate, whose isotropic point was previously detected (S. A. Kim, C. Grieswatch, H. Küppers, Zeit. Krist. 1993; 208:219-222) and exploited for a singular measurement of optical activity normal to the optic axis. The crystal structure associated with the aforementioned study was never published. We report it here, confirming the space group assignment I 4¯c2, along with the frequency dependence of the fundamental optical properties and the constitutive tensors by fitting optical dispersion relations to measured Mueller matrix spectra. k-Space maps of circular birefringence and of the Mueller matrix near the isotropic wavelength are measured and simulated. The signs of optical rotation are correlated with the absolute crystallographic directions. © 2018 Wiley Periodicals, Inc.

  2. Cathodoluminescence-activated nanoimaging: noninvasive near-field optical microscopy in an electron microscope.

    Science.gov (United States)

    Bischak, Connor G; Hetherington, Craig L; Wang, Zhe; Precht, Jake T; Kaz, David M; Schlom, Darrell G; Ginsberg, Naomi S

    2015-05-13

    We demonstrate a new nanoimaging platform in which optical excitations generated by a low-energy electron beam in an ultrathin scintillator are used as a noninvasive, near-field optical scanning probe of an underlying sample. We obtain optical images of Al nanostructures with 46 nm resolution and validate the noninvasiveness of this approach by imaging a conjugated polymer film otherwise incompatible with electron microscopy due to electron-induced damage. The high resolution, speed, and noninvasiveness of this "cathodoluminescence-activated" platform also show promise for super-resolution bioimaging.

  3. Research based activities in teacher professional development on optics

    International Nuclear Information System (INIS)

    Michelini, Marisa; Stefanel, Alberto

    2015-01-01

    The aim of this research is to understand how teachers take ownership of content given them in formative intervention modules and transform it into suggestions and materials for teaching. To this end a module on optics was designed for a group of kindergarten, primary and lower secondary school teachers which sought to integrate meta-cultural, experiential and situated approaches with various context specific factors. The study investigated how teachers deal with conceptual difficulties in the module and how they adapt it to their school situations with data being gathered through a variety of tools. It emerged that the most difficult concepts teachers encountered at the formative stage were those they most often incorporated into their materials. The steps taken in this process of appropriation were then reviewed via a collaborative discussion among the teachers themselves on the materials they had produced.

  4. TECHNICAL EQUIPMENT FOR SORTING APPLES BY SIZE

    Directory of Open Access Journals (Sweden)

    Vasilica Ştefan

    2012-01-01

    Full Text Available Need to increase the competitiveness of semi-subsistence farms, by valorisation of the fruits, led to research for designing of an equipment for sorting apples by size, in order to meet market requirement, pricing according to the size of the fruits.

  5. A note on sorting buffrs offline

    NARCIS (Netherlands)

    Chan, H.L.; Megow, N.; Sitters, R.A.; van Stee, R.

    2012-01-01

    We consider the offline sorting buffer problem. The input is a sequence of items of different types. All items must be processed one by one by a server. The server is equipped with a random-access buffer of limited capacity which can be used to rearrange items. The problem is to design a scheduling

  6. A cargo-sorting DNA robot.

    Science.gov (United States)

    Thubagere, Anupama J; Li, Wei; Johnson, Robert F; Chen, Zibo; Doroudi, Shayan; Lee, Yae Lim; Izatt, Gregory; Wittman, Sarah; Srinivas, Niranjan; Woods, Damien; Winfree, Erik; Qian, Lulu

    2017-09-15

    Two critical challenges in the design and synthesis of molecular robots are modularity and algorithm simplicity. We demonstrate three modular building blocks for a DNA robot that performs cargo sorting at the molecular level. A simple algorithm encoding recognition between cargos and their destinations allows for a simple robot design: a single-stranded DNA with one leg and two foot domains for walking, and one arm and one hand domain for picking up and dropping off cargos. The robot explores a two-dimensional testing ground on the surface of DNA origami, picks up multiple cargos of two types that are initially at unordered locations, and delivers them to specified destinations until all molecules are sorted into two distinct piles. The robot is designed to perform a random walk without any energy supply. Exploiting this feature, a single robot can repeatedly sort multiple cargos. Localization on DNA origami allows for distinct cargo-sorting tasks to take place simultaneously in one test tube or for multiple robots to collectively perform the same task. Copyright © 2017, American Association for the Advancement of Science.

  7. Smoothsort, an alternative for sorting in situ

    NARCIS (Netherlands)

    Dijkstra, E.W.

    1982-01-01

    Like heapsort - which inspired it - smoothsort is an algorithm for sorting in situ. It is of order N · log N in the worst case, but of order N in the best case, with a smooth transition between the two. (Hence its name.)

  8. Passive sorting of capsules by deformability

    Science.gov (United States)

    Haener, Edgar; Juel, Anne

    We study passive sorting according to deformability of liquid-filled ovalbumin-alginate capsules. We present results for two sorting geometries: a straight channel with a half-cylindrical obstruction and a pinched flow fractioning device (PFF) adapted for use with capsules. In the half-cylinder device, the capsules deform as they encounter the obstruction, and travel around the half-cylinder. The distance from the capsule's centre of mass to the surface of the half-cylinder depends on deformability, and separation between capsules of different deformability is amplified by diverging streamlines in the channel expansion downstream of the obstruction. We show experimentally that capsules can be sorted according to deformability with their downstream position depending on capillary number only, and we establish the sensitivity of the device to experimental variability. In the PFF device, particles are compressed against a wall using a strong pinching flow. We show that capsule deformation increases with the intensity of the pinching flow, but that the downstream capsule position is not set by deformation in the device. However, when using the PFF device like a T-Junction, we achieve improved sorting resolution compared to the half-cylinder device.

  9. 6. Algorithms for Sorting and Searching

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 3. Algorithms - Algorithms for Sorting and Searching. R K Shyamasundar. Series Article ... Author Affiliations. R K Shyamasundar1. Computer Science Group, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, India ...

  10. Conveyor for sorting radioactive waste

    International Nuclear Information System (INIS)

    Prisco, A.J.; Johnson, A.N.

    1987-01-01

    An apparatus is described for detecting radioactive components in dry active waste, the apparatus comprising: means for reducing the waste to pieces of substantially uniform size, first and second conveyors and a housing for the conveyors; means for conveying the pieces from the means for reducing the waste to the first and second conveyors; each of the first and second conveyors includes a receiving portion and a discharge portion; the discharge portion is spaced above and upstream from the receiving portion to disperse the pieces as they are transferred from the first conveyor to the second conveyor so that pieces which are in clusters are separated from each other to increase the likelihood of detecting radiation emanating means for detecting radioactive radiation emanating from the pieces, at least one of radiation detector means is located on each of the conveyors. Each is disposed in close overlying relation to its respective conveyor so that low levels of radiation emanating from the pieces can be detected; each of the conveyors includes means for flattening the pieces of waste before the pieces pass under the radiation detector means; and the means for flattening disposed between the receiving portion of each conveyor and the radiation detector means; the housing is generally closed; and means for providing a generally closed connection between the housing and the means for reducing the waste so that air that is in the housing and in the means for reducing the waste can be controlled

  11. Developments of a bonding technique for optical materials by a surface activation method

    International Nuclear Information System (INIS)

    Sugiyama, Akira; Oda, Tomohiro; Abe, Tomoyuki; Kusunoki, Isao

    2005-01-01

    We started developing the laser crystal bounding by the surface activation method which can splice crystals together without using hydrogen bonding. For the surface activation, neutral argon beams were used for irradiation of specimens. In the bonding trials with sapphire crystals, we recognized possibility of the bonding method for optical elements. (author)

  12. Design and construction of automatic sorting station with machine vision

    Directory of Open Access Journals (Sweden)

    Oscar D. Velasco-Delgado

    2014-01-01

    Full Text Available This article presents the design, construction and testing of an automatic product sorting system in belt conveyor with machine vision that integrates Free and Open Source Software technology and Allen Bradley commercial equipment. Requirements are defined to determine features such as: mechanics of manufacturing station, an app of product sorting with machine vision and for automation system. For the app of machine vision a library is used for optical digital image processing Open CV, for the mechanical design of the manufacturing station is used the CAD tool Solid Edge and for the design and implementation of automation ISA standards are used along with an automation engineering project methodology integrating a PLC, an inverter, a Panel View and a DeviceNet Network. Performance tests are shown by classifying bottles and PVC pieces in four established types, the behavior of the integrated system is checked so as the efficiency of the same. The processing time on machine vision is 0.290 s on average for a piece of PVC, a capacity of 206 accessories per minute, for bottles was obtained a processing time of 0.267 s, a capacity of 224 bottles per minute. A maximum mechanical performance is obtained with 32 products per minute (1920 products/hour with the conveyor to 22 cm/s and 40 cm of distance between products obtaining an average error of 0.8%.

  13. Optically-Induced Neuronal Activity Is Sufficient to Promote Functional Motor Axon Regeneration In Vivo.

    Directory of Open Access Journals (Sweden)

    Patricia J Ward

    Full Text Available Peripheral nerve injuries are common, and functional recovery is very poor. Beyond surgical repair of the nerve, there are currently no treatment options for these patients. In experimental models of nerve injury, interventions (such as exercise and electrical stimulation that increase neuronal activity of the injured neurons effectively enhance axon regeneration. Here, we utilized optogenetics to determine whether increased activity alone is sufficient to promote motor axon regeneration. In thy-1-ChR2/YFP transgenic mice in which a subset of motoneurons express the light-sensitive cation channel, channelrhodopsin (ChR2, we activated axons in the sciatic nerve using blue light immediately prior to transection and surgical repair of the sciatic nerve. At four weeks post-injury, direct muscle EMG responses evoked with both optical and electrical stimuli as well as the ratio of these optical/electrical evoked EMG responses were significantly greater in mice that received optical treatment. Thus, significantly more ChR2+ axons successfully re-innervated the gastrocnemius muscle in mice that received optical treatment. Sections of the gastrocnemius muscles were reacted with antibodies to Synaptic Vesicle Protein 2 (SV2 to quantify the number of re-occupied motor endplates. The number of SV2+ endplates was greater in mice that received optical treatment. The number of retrogradely-labeled motoneurons following intramuscular injection of cholera toxin subunit B (conjugated to Alexa Fluor 555 was greater in mice that received optical treatment. Thus, the acute (1 hour, one-time optical treatment resulted in robust, long-lasting effects compared to untreated animals as well as untreated axons (ChR2-. We conclude that neuronal activation is sufficient to promote motor axon regeneration, and this regenerative effect is specific to the activated neurons.

  14. Sorting method to extend the dynamic range of the Shack-Hartmann wave-front sensor

    International Nuclear Information System (INIS)

    Lee, Junwon; Shack, Roland V.; Descour, Michael R.

    2005-01-01

    We propose a simple and powerful algorithm to extend the dynamic range of a Shack-Hartmann wave-front sensor. In a conventional Shack-Hartmann wave-front sensor the dynamic range is limited by the f-number of a lenslet, because the focal spot is required to remain in the area confined by the single lenslet. The sorting method proposed here eliminates such a limitation and extends the dynamic range by tagging each spot in a special sequence. Since the sorting method is a simple algorithm that does not change the measurement configuration, there is no requirement for extra hardware, multiple measurements, or complicated algorithms. We not only present the theory and a calculation example of the sorting method but also actually implement measurement of a highly aberrated wave front from nonrotational symmetric optics

  15. Mimicking Faraday rotation to sort the orbital angular momentum of light.

    Science.gov (United States)

    Zhang, Wuhong; Qi, Qianqian; Zhou, Jie; Chen, Lixiang

    2014-04-18

    The efficient separation of the orbital angular momentum (OAM) is essential to both the classical and quantum applications with twisted photons. Here we devise and demonstrate experimentally an efficient method of mimicking the Faraday rotation to sort the OAM based on the OAM-to-polarization coupling effect induced by a modified Mach-Zehnder interferometer. Our device is capable of sorting the OAM of positive and negative numbers, as well as their mixtures. Furthermore, we report the first experimental demonstration to sort optical vortices of noninteger charges. The possibility of working at the photon-count level is also shown using an electron-multiplying CCD camera. Our scheme holds promise for quantum information applications with single-photon entanglement and for high-capacity communication systems with polarization and OAM multiplexing.

  16. Woody biomass comminution and sorting - a review of mechanical methods

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Gunnar [Swedish Univ. of Agricultural Sciences, Dept. of Forest Resource Management, Umeaa (Sweden)], e-mail: gunnar.eriksson@slu.se

    2012-11-01

    The increased demand for woody biomass for heat and electricity and biorefineries means that each bio component must be used efficiently. Any increase in raw material supply in the short term is likely to require the use of trees from early thinnings, logging residues and stumps, assortments of low value compared to stemwood. However, sorting of the novel materials into bio components may increase their value considerably. The challenge is to 1) maximise the overall values of the different raw material fractions for different users, 2) minimise costs for raw material extraction, processing, storage and transportation. Comminution of the raw material (e.g. to chips, chunks, flakes and powder) and sorting the bio components (e.g. separating bark from pulp chips and separating alkali-rich needles and shots for combustion and gasification applications) are crucial processes in this optimisation. The purpose of this study has been to make a literature review of principles for comminution and sorting, with an emphasis on mechanical methods suitable outside industries. More efficient comminution methods can be developed when the wood is to a larger extent cut along the fibre direction, and closer to the surface (with less pressure to the sides of the knife). By using coarse comminution (chunking) rather than fine comminution (chipping), productivity at landings can be increased and energy saved, the resulting product will have better storage and drying properties. At terminals, any further comminution (if necessary) could use larger-scale equipment of higher efficiency. Rolls and flails can be used to an increasing extent for removing foliage and twigs, possibly in the terrain (for instance fitted on grapples). Physical parameters used for sorting of the main components of trees include particle size, density and shape (aerodynamic drag and lift), optical and IR properties and X-ray fluorescence. Although methods developed for pulp chip production from whole trees may not

  17. Active locking and entanglement in type II optical parametric oscillators

    Science.gov (United States)

    Ruiz-Rivas, Joaquín; de Valcárcel, Germán J.; Navarrete-Benlloch, Carlos

    2018-02-01

    Type II optical parametric oscillators are amongst the highest-quality sources of quantum-correlated light. In particular, when pumped above threshold, such devices generate a pair of bright orthogonally-polarized beams with strong continuous-variable entanglement. However, these sources are of limited practical use, because the entangled beams emerge with different frequencies and a diffusing phase difference. It has been proven that the use of an internal wave-plate coupling the modes with orthogonal polarization is capable of locking the frequencies of the emerging beams to half the pump frequency, as well as reducing the phase-difference diffusion, at the expense of reducing the entanglement levels. In this work we characterize theoretically an alternative locking mechanism: the injection of a laser at half the pump frequency. Apart from being less invasive, this method should allow for an easier real-time experimental control. We show that such an injection is capable of generating the desired phase locking between the emerging beams, while still allowing for large levels of entanglement. Moreover, we find an additional region of the parameter space (at relatively large injections) where a mode with well defined polarization is in a highly amplitude-squeezed state.

  18. Passive radiation detection using optically active CMOS sensors

    Science.gov (United States)

    Dosiek, Luke; Schalk, Patrick D.

    2013-05-01

    Recently, there have been a number of small-scale and hobbyist successes in employing commodity CMOS-based camera sensors for radiation detection. For example, several smartphone applications initially developed for use in areas near the Fukushima nuclear disaster are capable of detecting radiation using a cell phone camera, provided opaque tape is placed over the lens. In all current useful implementations, it is required that the sensor not be exposed to visible light. We seek to build a system that does not have this restriction. While building such a system would require sophisticated signal processing, it would nevertheless provide great benefits. In addition to fulfilling their primary function of image capture, cameras would also be able to detect unknown radiation sources even when the danger is considered to be low or non-existent. By experimentally profiling the image artifacts generated by gamma ray and β particle impacts, algorithms are developed to identify the unique features of radiation exposure, while discarding optical interaction and thermal noise effects. Preliminary results focus on achieving this goal in a laboratory setting, without regard to integration time or computational complexity. However, future work will seek to address these additional issues.

  19. Stable aqueous dispersions of optically and electronically active phosphorene.

    Science.gov (United States)

    Kang, Joohoon; Wells, Spencer A; Wood, Joshua D; Lee, Jae-Hyeok; Liu, Xiaolong; Ryder, Christopher R; Zhu, Jian; Guest, Jeffrey R; Husko, Chad A; Hersam, Mark C

    2016-10-18

    Understanding and exploiting the remarkable optical and electronic properties of phosphorene require mass production methods that avoid chemical degradation. Although solution-based strategies have been developed for scalable exfoliation of black phosphorus, these techniques have thus far used anhydrous organic solvents in an effort to minimize exposure to known oxidants, but at the cost of limited exfoliation yield and flake size distribution. Here, we present an alternative phosphorene production method based on surfactant-assisted exfoliation and postprocessing of black phosphorus in deoxygenated water. From comprehensive microscopic and spectroscopic analysis, this approach is shown to yield phosphorene dispersions that are stable, highly concentrated, and comparable to micromechanically exfoliated phosphorene in structure and chemistry. Due to the high exfoliation efficiency of this process, the resulting phosphorene flakes are thinner than anhydrous organic solvent dispersions, thus allowing the observation of layer-dependent photoluminescence down to the monolayer limit. Furthermore, to demonstrate preservation of electronic properties following solution processing, the aqueous-exfoliated phosphorene flakes are used in field-effect transistors with high drive currents and current modulation ratios. Overall, this method enables the isolation and mass production of few-layer phosphorene, which will accelerate ongoing efforts to realize a diverse range of phosphorene-based applications.

  20. PhySortR: a fast, flexible tool for sorting phylogenetic trees in R.

    Science.gov (United States)

    Stephens, Timothy G; Bhattacharya, Debashish; Ragan, Mark A; Chan, Cheong Xin

    2016-01-01

    A frequent bottleneck in interpreting phylogenomic output is the need to screen often thousands of trees for features of interest, particularly robust clades of specific taxa, as evidence of monophyletic relationship and/or reticulated evolution. Here we present PhySortR, a fast, flexible R package for classifying phylogenetic trees. Unlike existing utilities, PhySortR allows for identification of both exclusive and non-exclusive clades uniting the target taxa based on tip labels (i.e., leaves) on a tree, with customisable options to assess clades within the context of the whole tree. Using simulated and empirical datasets, we demonstrate the potential and scalability of PhySortR in analysis of thousands of phylogenetic trees without a priori assumption of tree-rooting, and in yielding readily interpretable trees that unambiguously satisfy the query. PhySortR is a command-line tool that is freely available and easily automatable.

  1. ScanSort{sup SM} at Whiteshell Laboratories for sorting of experimental cesium pond soil

    Energy Technology Data Exchange (ETDEWEB)

    Downey, H., E-mail: heath.downey@amecfw.com [Amec Foster Wheeler, Portland, ME (United States)

    2015-07-01

    The ScanSort{sup SM} soil sorting system is a unique and efficient radiological instrument used for measuring and sorting bulk soils and volumetric materials. The system performs automatic radioassay and segregation of preconditioned material using a gamma spectroscopy system mounted above a conveyor belt. It was deployed to the Whiteshell Laboratories site to process the excavated soils generated during the decommissioning of the former Experimental Cesium Pond. The ScanSort{sup SM} system was utilized to segregate material with Cs-137 concentrations above the established site unrestricted release and restricted site reuse levels as well as demonstrated the ability to accurately determine the radioactivity concentrations of the radiologically-impacted material and to confidently segregate volumes of that material for appropriate final disposition. (author)

  2. Ratio Imaging of Enzyme Activity Using Dual Wavelength Optical Reporters

    Directory of Open Access Journals (Sweden)

    Moritz F. Kircher

    2002-04-01

    Full Text Available The design of near-infrared fluorescent (NIRF probes that are activated by specific proteases has, for the first time, allowed enzyme activity to be imaged in vivo. In the current study, we report on a method of imaging enzyme activity using two fluorescent probes that, together, provide improved quantitation of enzymatic activity. The method employs two chemically similar probes that differ in their degradability by cathepsin B. One probe consists of the NIRF dye Cy5.5 attached to a particulate carrier, a crosslinked iron oxide nanoparticle (CLIO, through cathepsin B cleavable l-arginyl peptides. A second probe consists of Cy3.5 attached to a CLIO through proteolytically resistant d-arginyl peptides. Using mixtures of the two probes, we have shown that the ratio of Cy5.5 to Cy3.5 fluorescence can be used to determine levels of cathepsin B in the environment of nanoparticles with macrophages in suspension. After intravenous injection, tissue fluorescence from the nondegradable Cy3.5–d-arginyl probe reflected nanoparticle accumulation, while fluorescence of the Cy5.5–l-arginyl probe was dependent on both accumulation and activation by cathepsin B. Dual wavelength ratio imaging can be used for the quantitative imaging of a variety of enzymes in clinically important settings, while the magnetic properties of the probes allow their detection by MR imaging.

  3. Identification and sorting of materials with portable LIBS before decommissioning

    International Nuclear Information System (INIS)

    Vors, Evelyne; Sirven, Jean-Baptiste; Dehayem-Massop, Alix; Gallou, Guillaume

    2016-01-01

    Laser Induced Breakdown Spectroscopy (LIBS) is a technique of elemental analysis. A laser beam is focused on the surface of the sample to be analyzed. A small quantity of matter is ablated and a plasma formed by the atomized compounds is created. The spectral lines of the light emitted by the plasma are detected by an optical spectrometer. LIBS is a fully optical, multi-elementary and fast analytical technique, requiring no or little sample preparation. These features make the LIBS technique particularly suited for in situ measurements, and portable instruments are currently developed. LIBS analysis can be applied to the identification of materials using chemometric statistical methods (multivariate analysis) connecting the spectrum to the nature of the sample. Such methods have been successfully applied in our laboratory to the determination of the geographical origin of yellow cakes and to the identification of alloys. We present here the work performed with a portable LIBS instrument to meet the needs of waste sorting in industrial domain and in nuclear domain (inventory before decommissioning). A data base of LIBS spectra was built with a commercial instrument (IVEA SAS Easylibs) with samples of four categories of interest for industrial waste sorting: alloys, plastics, concrete and glasses. Different correct identification rates are requested by categories. The alloy spectra contain characteristic spectral lines and sub-categories can be easily discriminated (for example, different steel classes can be identified). The components of the plastics (mainly C, H, O and N) give rise to less characteristic lines and the plastics identification requires a separate study. Supervised statistical models are built with the data base spectra and predictions are instantly calculated for the spectra of unknown materials to identify in order to direct them to the correct waste stream. (authors)

  4. Sorting signed permutations by short operations.

    Science.gov (United States)

    Galvão, Gustavo Rodrigues; Lee, Orlando; Dias, Zanoni

    2015-01-01

    During evolution, global mutations may alter the order and the orientation of the genes in a genome. Such mutations are referred to as rearrangement events, or simply operations. In unichromosomal genomes, the most common operations are reversals, which are responsible for reversing the order and orientation of a sequence of genes, and transpositions, which are responsible for switching the location of two contiguous portions of a genome. The problem of computing the minimum sequence of operations that transforms one genome into another - which is equivalent to the problem of sorting a permutation into the identity permutation - is a well-studied problem that finds application in comparative genomics. There are a number of works concerning this problem in the literature, but they generally do not take into account the length of the operations (i.e. the number of genes affected by the operations). Since it has been observed that short operations are prevalent in the evolution of some species, algorithms that efficiently solve this problem in the special case of short operations are of interest. In this paper, we investigate the problem of sorting a signed permutation by short operations. More precisely, we study four flavors of this problem: (i) the problem of sorting a signed permutation by reversals of length at most 2; (ii) the problem of sorting a signed permutation by reversals of length at most 3; (iii) the problem of sorting a signed permutation by reversals and transpositions of length at most 2; and (iv) the problem of sorting a signed permutation by reversals and transpositions of length at most 3. We present polynomial-time solutions for problems (i) and (iii), a 5-approximation for problem (ii), and a 3-approximation for problem (iv). Moreover, we show that the expected approximation ratio of the 5-approximation algorithm is not greater than 3 for random signed permutations with more than 12 elements. Finally, we present experimental results that show

  5. Solution structures of potato virus X and narcissus mosaic virus from Raman optical activity

    DEFF Research Database (Denmark)

    Blanch, Ewan W.; Robinson, David J.; Hecht, Lutz

    2002-01-01

    Potato virus X (PVX) and narcissus mosaic virus (NMV) were studied using vibrational Raman optical activity (ROA) in order to obtain new information on the structures of their coat protein subunits. The ROA spectra of the two intact virions are very similar to each other and similar to that of to......Potato virus X (PVX) and narcissus mosaic virus (NMV) were studied using vibrational Raman optical activity (ROA) in order to obtain new information on the structures of their coat protein subunits. The ROA spectra of the two intact virions are very similar to each other and similar...

  6. Chimeric microbial rhodopsins for optical activation of Gs-proteins

    Science.gov (United States)

    Yoshida, Kazuho; Yamashita, Takahiro; Sasaki, Kengo; Inoue, Keiichi; Shichida, Yoshinori; Kandori, Hideki

    2017-01-01

    We previously showed that the chimeric proteins of microbial rhodopsins, such as light-driven proton pump bacteriorhodopsin (BR) and Gloeobacter rhodopsin (GR) that contain cytoplasmic loops of bovine rhodopsin, are able to activate Gt protein upon light absorption. These facts suggest similar protein structural changes in both the light-driven proton pump and animal rhodopsin. Here we report two trials to engineer chimeric rhodopsins, one for the inserted loop, and another for the microbial rhodopsin template. For the former, we successfully activated Gs protein by light through the incorporation of the cytoplasmic loop of β2-adrenergic receptor (β2AR). For the latter, we did not observe any G-protein activation for the light-driven sodium pump from Indibacter alkaliphilus (IndiR2) or a light-driven chloride pump halorhodopsin from Natronomonas pharaonis (NpHR), whereas the light-driven proton pump GR showed light-dependent G-protein activation. This fact suggests that a helix opening motion is common to G protein coupled receptor (GPCR) and GR, but not to IndiR2 and NpHR. Light-induced difference FTIR spectroscopy revealed similar structural changes between WT and the third loop chimera for each light-driven pump. A helical structural perturbation, which was largest for GR, was further enhanced in the chimera. We conclude that similar structural dynamics that occur on the cytoplasmic side of GPCR are needed to design chimeric microbial rhodopsins. PMID:29362703

  7. A new technology for automatic identification and sorting of plastics for recycling.

    Science.gov (United States)

    Ahmad, S R

    2004-10-01

    A new technology for automatic sorting of plastics, based upon optical identification of fluorescence signatures of dyes, incorporated in such materials in trace concentrations prior to product manufacturing, is described. Three commercial tracers were selected primarily on the basis of their good absorbency in the 310-370 nm spectral band and their identifiable narrow-band fluorescence signatures in the visible band of the spectrum when present in binary combinations. This absorption band was selected because of the availability of strong emission lines in this band from a commercial Hg-arc lamp and high fluorescence quantum yields of the tracers at this excitation wavelength band. The plastics chosen for tracing and identification are HDPE, LDPE, PP, EVA, PVC and PET and the tracers were compatible and chemically non-reactive with the host matrices and did not affect the transparency of the plastics. The design of a monochromatic and collimated excitation source, the sensor system are described and their performances in identifying and sorting plastics doped with tracers at a few parts per million concentration levels are evaluated. In an industrial sorting system, the sensor was able to sort 300 mm long plastic bottles at a conveyor belt speed of 3.5 m.sec(-1) with a sorting purity of -95%. The limitation was imposed due to mechanical singulation irregularities at high speed and the limited processing speed of the computer used.

  8. Aldefluor protocol to sort keratinocytes stem cells from skin

    OpenAIRE

    Noronha, Samuel Marcos Ribeiro; Gragnani, Alfredo; Pereira, Thiago Antônio Calado; Correa, Silvana Aparecida Alves; Bonucci, Jessica; Ferreira, Lydia Masako

    2017-01-01

    Abstract Purpose: To investigate the use Aldefluor® and N, N - Dimethylaminobenzaldehyde (DEAB) to design a protocol to sort keratinocyte stem cells from cultured keratinocytes from burned patients. Methods: Activated Aldefluor® aliquots were prepared and maintained at temperature between 2 to 8°C, or stored at -20°C. Next, the cells were collected following the standard protocol of sample preparation. Results: Best results were obtained with Aldefluor® 1.5µl and DEAB 15 µl for 1 x 106 c...

  9. Reduced risk of compressive optic neuropathy using orbital radiotherapy in patients with active thyroid eye disease.

    Science.gov (United States)

    Shams, Pari N; Ma, Roy; Pickles, Tom; Rootman, Jack; Dolman, Peter J

    2014-06-01

    To compare the risk of developing compressive optic neuropathy in patients with active thyroid eye disease (TED) treated with corticosteroids with or without orbital radiotherapy. Retrospective single-center case-control study. The clinical charts of 351 patients with active TED who received corticosteroids with or without orbital radiotherapy between 1999 and 2010 were reviewed. Patients with compressive optic neuropathy at the time of presentation were excluded. Group 1 received corticosteroids only and Group 2 received corticosteroids as well as orbital radiotherapy. The primary outcome measure was the development of compressive optic neuropathy. Secondary outcome measures were changes in other parameters indicating the activity of TED, including soft tissue inflammation, diplopia, ocular motility restriction, and appearance. There were 144 cases in Group 1 and 105 in Group 2. Both groups were matched for age, sex, and stability of thyroid function. The 2 groups differed only in the modality of treatment for active TED. The main indication for treatment in both groups was soft tissue inflammation. Corticosteroids were initiated an average of 2.6 months following symptom onset in Group 1 and 2.5 months in Group 2. Group 2 received orbital radiotherapy on average 4.2 months following the initiation of corticosteroid therapy and 8% (9/105) were intolerant to corticosteroids. At an average of 3.2 years follow-up, compressive optic neuropathy had developed in 17% (25/144) of Group 1 and 0% of Group 2 (P optic neuropathy was significantly lower and improvement in ocular motility greater in patients receiving orbital radiotherapy in addition to corticosteroids. Patients with active TED appear to have an effective and sustained response to orbital radiotherapy combined with corticosteroids that is protective against disease progression and the development of compressive optic neuropathy. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. A mower detector to judge soil sorting

    International Nuclear Information System (INIS)

    Bramlitt, E.T.; Johnson, N.R.

    1995-01-01

    Thermo Nuclear Services (TNS) has developed a mower detector as an inexpensive and fast means for deciding potential value of soil sorting for cleanup. It is a shielded detector box on wheels pushed over the ground (as a person mows grass) at 30 ft/min with gamma-ray counts recorded every 0.25 sec. It mirror images detection by the TNS transportable sorter system which conveys soil at 30 ft/min and toggles a gate to send soil on separate paths based on counts. The mower detector shows if contamination is variable and suitable for sorting, and by unique calibration sources, it indicates detection sensitivity. The mower detector has been used to characterize some soil at Department of Energy sites in New Jersey and South Carolina

  11. Sorting processes with energy-constrained comparisons*

    Science.gov (United States)

    Geissmann, Barbara; Penna, Paolo

    2018-05-01

    We study very simple sorting algorithms based on a probabilistic comparator model. In this model, errors in comparing two elements are due to (1) the energy or effort put in the comparison and (2) the difference between the compared elements. Such algorithms repeatedly compare and swap pairs of randomly chosen elements, and they correspond to natural Markovian processes. The study of these Markov chains reveals an interesting phenomenon. Namely, in several cases, the algorithm that repeatedly compares only adjacent elements is better than the one making arbitrary comparisons: in the long-run, the former algorithm produces sequences that are "better sorted". The analysis of the underlying Markov chain poses interesting questions as the latter algorithm yields a nonreversible chain, and therefore its stationary distribution seems difficult to calculate explicitly. We nevertheless provide bounds on the stationary distributions and on the mixing time of these processes in several restrictions.

  12. Colour based sorting station with Matlab simulation

    Directory of Open Access Journals (Sweden)

    Constantin Victor

    2017-01-01

    Full Text Available The paper presents the design process and manufacturing elements of a colour-based sorting station. The system is comprised of a gravitational storage, which also contains the colour sensor. Parts are extracted using a linear pneumatic motor and are fed onto an electrically driven conveyor belt. Extraction of the parts is done at 4 points, using two pneumatic motors and a geared DC motor, while the 4th position is at the end of the belt. The mechanical parts of the system are manufactured using 3D printer technology, allowing for easy modification and adaption to the geometry of different parts. The paper shows all of the stages needed to design, optimize, test and implement the proposed solution. System optimization was performed using a graphical Matlab interface which also allows for sorting algorithm optimization.

  13. Efficient sorting using registers and caches

    DEFF Research Database (Denmark)

    Wickremesinghe, Rajiv; Arge, Lars Allan; Chase, Jeffrey S.

    2002-01-01

    . Inadequate models lead to poor algorithmic choices and an incomplete understanding of algorithm behavior on real machines.A key step toward developing better models is to quantify the performance effects of features not reflected in the models. This paper explores the effect of memory system features...... on sorting performance. We introduce a new cache-conscious sorting algorithm, R-MERGE, which achieves better performance in practice over algorithms that are superior in the theoretical models. R-MERGE is designed to minimize memory stall cycles rather than cache misses by considering features common to many......Modern computer systems have increasingly complex memory systems. Common machine models for algorithm analysis do not reflect many of the features of these systems, e.g., large register sets, lockup-free caches, cache hierarchies, associativity, cache line fetching, and streaming behavior...

  14. A mower detector to judge soil sorting

    Energy Technology Data Exchange (ETDEWEB)

    Bramlitt, E.T.; Johnson, N.R. [Thermo Nuclear Services, Inc., Albuquerque, NM (United States)

    1995-12-31

    Thermo Nuclear Services (TNS) has developed a mower detector as an inexpensive and fast means for deciding potential value of soil sorting for cleanup. It is a shielded detector box on wheels pushed over the ground (as a person mows grass) at 30 ft/min with gamma-ray counts recorded every 0.25 sec. It mirror images detection by the TNS transportable sorter system which conveys soil at 30 ft/min and toggles a gate to send soil on separate paths based on counts. The mower detector shows if contamination is variable and suitable for sorting, and by unique calibration sources, it indicates detection sensitivity. The mower detector has been used to characterize some soil at Department of Energy sites in New Jersey and South Carolina.

  15. Efficient Sorting on the Tilera Manycore Architecture

    Energy Technology Data Exchange (ETDEWEB)

    Morari, Alessandro; Tumeo, Antonino; Villa, Oreste; Secchi, Simone; Valero, Mateo

    2012-10-24

    e present an efficient implementation of the radix sort algo- rithm for the Tilera TILEPro64 processor. The TILEPro64 is one of the first successful commercial manycore processors. It is com- posed of 64 tiles interconnected through multiple fast Networks- on-chip and features a fully coherent, shared distributed cache. The architecture has a large degree of flexibility, and allows various optimization strategies. We describe how we mapped the algorithm to this architecture. We present an in-depth analysis of the optimizations for each phase of the algorithm with respect to the processor’s sustained performance. We discuss the overall throughput reached by our radix sort implementation (up to 132 MK/s) and show that it provides comparable or better performance-per-watt with respect to state-of-the art implemen- tations on x86 processors and graphic processing units.

  16. Quantum dynamics of spin qubits in optically active quantum dots

    International Nuclear Information System (INIS)

    Bechtold, Alexander

    2017-01-01

    The control of solid-state qubits for quantum information processing requires a detailed understanding of the mechanisms responsible for decoherence. During the past decade a considerable progress has been achieved for describing the qubit dynamics in relatively strong external magnetic fields. However, until now it has been impossible to experimentally test many theoretical predictions at very low magnetic fields and uncover mechanisms associated with reduced coherence times of spin qubits in solids. In particular, the role of the quadrupolar coupling of nuclear spins in this process is to date poorly understood. In the framework of this thesis, a spin memory device is utilized to optically prepare individual electron spin qubits in a single InGaAs quantum dot. After storages over timescales extending into the microsecond range the qubit��s state is read out to monitor the impact of the environment on it the spin dynamics. By performing such pump-probe experiments, the dominant electron spin decoherence mechanisms are identified in a wide range of external magnetic fields (0-5 T) and lattice temperatures of ∝10 K. The results presented in this thesis show that, without application of external magnetic fields the initially orientated electron spin rapidly loses its polarization due to precession around the fluctuating Overhauser field with a dispersion of 10.5 mT. The inhomogeneous dephasing time associated with these hyperfine mediated dynamics is of the order of T * 2 =2 ns. Over longer timescales, an unexpected stage of central spin relaxation is observed, namely the appearance of a second feature in the relaxation curve around T Q =750 ns. By comparison with theoretical simulations, this additional decoherence channel is shown to arise from coherent dynamics in the nuclear spin bath itself. Such coherent dynamics are induced by a quadrupolar coupling of the nuclear spins to the strain induced electric field gradients in the quantum dot. These processes

  17. Performance pay, sorting and social motivation

    OpenAIRE

    Eriksson, Tor; Villeval, Marie Claire

    2008-01-01

    International audience; Variable pay links pay and performance but may also help firms in attracting more productive employees. Our experiment investigates the impact of performance pay on both incentives and sorting and analyzes the influence of repeated interactions between firms and employees on these effects. We show that (i) the opportunity to switch from a fixed wage to variable pay scheme increases the average effort level and its variance; (ii) high skill employees concentrate under t...

  18. A sorting network in bounded arithmetic

    Czech Academy of Sciences Publication Activity Database

    Jeřábek, Emil

    2011-01-01

    Roč. 162, č. 4 (2011), s. 341-355 ISSN 0168-0072 R&D Projects: GA AV ČR IAA1019401; GA MŠk(CZ) 1M0545 Institutional research plan: CEZ:AV0Z10190503 Keywords : bounded arithmetic * sorting network * proof complexity * monotone sequent calculus Subject RIV: BA - General Mathematics Impact factor: 0.450, year: 2011 http://www.sciencedirect.com/science/article/pii/S0168007210001272

  19. Job Sorting in African Labor Markets

    OpenAIRE

    Marcel Fafchamps; Mans Soderbom; Najy Benhassine

    2006-01-01

    Using matched employer-employee data from eleven African countries, we investigate if there is a job sorting in African labor markets. We find that much of the wage gap correlated with education is driven by selection across occupations and firms. This is consistent with educated workers being more effective at complex tasks like labor management. In all countries the education wage gap widens rapidly at high low levels of education. Most of the education wage gap at low levels of education c...

  20. Raman tweezers in microfluidic systems for analysis and sorting of living cells

    Science.gov (United States)

    Pilát, Zdeněk.; Ježek, Jan; Kaňka, Jan; Zemánek, Pavel

    2014-12-01

    We have devised an analytical and sorting system combining optical trapping with Raman spectroscopy in microfluidic environment, dedicated to identification and sorting of biological objects, such as living cells of various unicellular organisms. Our main goal was to create a robust and universal platform for non-destructive and non-contact sorting of micro-objects based on their Raman spectral properties. This approach allowed us to collect spectra containing information about the chemical composition of the objects, such as the presence and composition of pigments, lipids, proteins, or nucleic acids, avoiding artificial chemical probes such as fluorescent markers. The non-destructive nature of this optical analysis and manipulation allowed us to separate individual living cells of our interest in a sterile environment and provided the possibility to cultivate the selected cells for further experiments. We used a mixture of polystyrene micro-particles and algal cells to test and demonstrate the function of our analytical and sorting system. The devised system could find its use in many medical, biotechnological, and biological applications.

  1. Novel silica surface charge density mediated control of the optical properties of embedded optically active materials and its application for fiber optic pH sensing at elevated temperatures.

    Science.gov (United States)

    Wang, Congjun; Ohodnicki, Paul R; Su, Xin; Keller, Murphy; Brown, Thomas D; Baltrus, John P

    2015-02-14

    Silica and silica incorporated nanocomposite materials have been extensively studied for a wide range of applications. Here we demonstrate an intriguing optical effect of silica that, depending on the solution pH, amplifies or attenuates the optical absorption of a variety of embedded optically active materials with very distinct properties, such as plasmonic Au nanoparticles, non-plasmonic Pt nanoparticles, and the organic dye rhodamine B (not a pH indicator), coated on an optical fiber. Interestingly, the observed optical response to varying pH appears to follow the surface charge density of the silica matrix for all the three different optically active materials. To the best of our knowledge, this optical effect has not been previously reported and it appears universal in that it is likely that any optically active material can be incorporated into the silica matrix to respond to solution pH or surface charge density variations. A direct application of this effect is for optical pH sensing which has very attractive features that can enable minimally invasive, remote, real time and continuous distributed pH monitoring. Particularly, as demonstrated here, using highly stable metal nanoparticles embedded in an inorganic silica matrix can significantly improve the capability of pH sensing in extremely harsh environments which is of increasing importance for applications in unconventional oil and gas resource recovery, carbon sequestration, water quality monitoring, etc. Our approach opens a pathway towards possible future development of robust optical pH sensors for the most demanding environmental conditions. The newly discovered optical effect of silica also offers the potential for control of the optical properties of optically active materials for a range of other potential applications such as electrochromic devices.

  2. Parallel integer sorting with medium and fine-scale parallelism

    Science.gov (United States)

    Dagum, Leonardo

    1993-01-01

    Two new parallel integer sorting algorithms, queue-sort and barrel-sort, are presented and analyzed in detail. These algorithms do not have optimal parallel complexity, yet they show very good performance in practice. Queue-sort designed for fine-scale parallel architectures which allow the queueing of multiple messages to the same destination. Barrel-sort is designed for medium-scale parallel architectures with a high message passing overhead. The performance results from the implementation of queue-sort on a Connection Machine CM-2 and barrel-sort on a 128 processor iPSC/860 are given. The two implementations are found to be comparable in performance but not as good as a fully vectorized bucket sort on the Cray YMP.

  3. Stochastic Model of Vesicular Sorting in Cellular Organelles

    Science.gov (United States)

    Vagne, Quentin; Sens, Pierre

    2018-02-01

    The proper sorting of membrane components by regulated exchange between cellular organelles is crucial to intracellular organization. This process relies on the budding and fusion of transport vesicles, and should be strongly influenced by stochastic fluctuations, considering the relatively small size of many organelles. We identify the perfect sorting of two membrane components initially mixed in a single compartment as a first passage process, and we show that the mean sorting time exhibits two distinct regimes as a function of the ratio of vesicle fusion to budding rates. Low ratio values lead to fast sorting but result in a broad size distribution of sorted compartments dominated by small entities. High ratio values result in two well-defined sorted compartments but sorting is exponentially slow. Our results suggest an optimal balance between vesicle budding and fusion for the rapid and efficient sorting of membrane components and highlight the importance of stochastic effects for the steady-state organization of intracellular compartments.

  4. Optics outreach activities with elementary school kids from public education in Mexico

    Science.gov (United States)

    Viera-González, P.; Sánchez-Guerrero, G.; Ruiz-Mendoza, J.; Cárdenas-Ortiz, G.; Ceballos-Herrera, D.; Selvas-Aguilar, R.

    2014-09-01

    This work shows the results obtained from the "O4K" Project supported by International Society for Optics and Photonis (SPIE) and the Universidad Autonoma de Nuevo Leon (UANL) through its SPIE Student Chapter and the Dr. Juan Carlos Ruiz-Mendoza, outreach coordinator of the Facultad de Ciencias Fisico Matematicas of the UANL. Undergraduate and graduate students designed Optics representative activities using easy-access materials that allow the interaction of children with optics over the exploration, observation and experimentation, taking as premise that the best way to learn Science is the interaction with it. Several activities were realized through the 2011-2013 events with 1,600 kids with ages from 10 to 12; the results were analyzed using surveys. One of the principal conclusions is that in most of the cases the children changed their opinions about Sciences in a positive way.

  5. The age of enlightenment: evolving opportunities in brain research through optical manipulation of neuronal activity

    Directory of Open Access Journals (Sweden)

    Jason eJerome

    2011-12-01

    Full Text Available Optical manipulation of neuronal activity has rapidly developed into the most powerful and widely used approach to study mechanisms related to neuronal connectivity over a range of scales. Since the early use of single site uncaging to map network connectivity, rapid technological development of light modulation techniques has added important new options, such as fast scanning photostimulation, massively parallel control of light stimuli, holographic uncaging and 2-photon stimulation techniques. Exciting new developments in optogenetics complement neurotransmitter uncaging techniques by providing cell-type specificity and in vivo usability, providing optical access to the neural substrates of behavior. Here we review the rapid evolution of methods for the optical manipulation of neuronal activity, emphasizing crucial recent developments.

  6. The age of enlightenment: evolving opportunities in brain research through optical manipulation of neuronal activity.

    Science.gov (United States)

    Jerome, Jason; Heck, Detlef H

    2011-01-01

    Optical manipulation of neuronal activity has rapidly developed into the most powerful and widely used approach to study mechanisms related to neuronal connectivity over a range of scales. Since the early use of single site uncaging to map network connectivity, rapid technological development of light modulation techniques has added important new options, such as fast scanning photostimulation, massively parallel control of light stimuli, holographic uncaging, and two-photon stimulation techniques. Exciting new developments in optogenetics complement neurotransmitter uncaging techniques by providing cell-type specificity and in vivo usability, providing optical access to the neural substrates of behavior. Here we review the rapid evolution of methods for the optical manipulation of neuronal activity, emphasizing crucial recent developments.

  7. Co-assembly of viral envelope glycoproteins regulates their polarized sorting in neurons.

    Directory of Open Access Journals (Sweden)

    Rafael Mattera

    2014-05-01

    Full Text Available Newly synthesized envelope glycoproteins of neuroinvasive viruses can be sorted in a polarized manner to the somatodendritic and/or axonal domains of neurons. Although critical for transneuronal spread of viruses, the molecular determinants and interregulation of this process are largely unknown. We studied the polarized sorting of the attachment (NiV-G and fusion (NiV-F glycoproteins of Nipah virus (NiV, a paramyxovirus that causes fatal human encephalitis, in rat hippocampal neurons. When expressed individually, NiV-G exhibited a non-polarized distribution, whereas NiV-F was specifically sorted to the somatodendritic domain. Polarized sorting of NiV-F was dependent on interaction of tyrosine-based signals in its cytosolic tail with the clathrin adaptor complex AP-1. Co-expression of NiV-G with NiV-F abolished somatodendritic sorting of NiV-F due to incorporation of NiV-G•NiV-F complexes into axonal transport carriers. We propose that faster biosynthetic transport of unassembled NiV-F allows for its proteolytic activation in the somatodendritic domain prior to association with NiV-G and axonal delivery of NiV-G•NiV-F complexes. Our study reveals how interactions of viral glycoproteins with the host's transport machinery and between themselves regulate their polarized sorting in neurons.

  8. The role of waste sorting in the South African gold-mining industry

    International Nuclear Information System (INIS)

    Freer, J.S.; Boehme, R.C.

    1985-01-01

    The absolute potential for sorting waste from run-of-mine Witwatersrand gold ores normally lies between 60 and 90 per cent by mass. At present, the practical potential lies between 40 and 50 per cent. Yet few mines achieve a waste rejection of even 30 per cent. The average waste rejection for industry, including underground sorting, fell from 19,6 per cent in 1959 to 10,1 per cent in 1983, as industry moved from labour-intensive, multistage comminution, incorporating washing, screening, and sorting, to single-stage run-of-mine milling. Most of the sorting is still being done by hand; yet photometric and radiometric sorting machines of high capacity are available. More recently, a sorter based on neutron activation and the subsequent isomeric radioactive decay of gold itself was designed. This paper examines the case for an increased role for sorting in the South African gold-mining industry brought about by the increasing cost of power for milling and the possibility of extracting gold from low-grade reject fractions by heap leaching

  9. Automatic Color Sorting of Hardwood Edge-Glued Panel Parts

    Science.gov (United States)

    D. Earl Kline; Richard Conners; Qiang Lu; Philip A. Araman

    1997-01-01

    This paper describes an automatic color sorting system for red oak edge-glued panel parts. The color sorting system simultaneously examines both faces of a panel part and then determines which face has the "best" color, and sorts the part into one of a number of color classes at plant production speeds. Initial test results show that the system generated over...

  10. Categorizing Variations of Student-Implemented Sorting Algorithms

    Science.gov (United States)

    Taherkhani, Ahmad; Korhonen, Ari; Malmi, Lauri

    2012-01-01

    In this study, we examined freshmen students' sorting algorithm implementations in data structures and algorithms' course in two phases: at the beginning of the course before the students received any instruction on sorting algorithms, and after taking a lecture on sorting algorithms. The analysis revealed that many students have insufficient…

  11. Order-sorted Algebraic Specifications with Higher-order Functions

    DEFF Research Database (Denmark)

    Haxthausen, Anne Elisabeth

    1995-01-01

    This paper gives a proposal for how order-sorted algebraic specification languages can be extended with higher-order functions. The approach taken is a generalisation to the order-sorted case of an approach given by Mller, Tarlecki and Wirsing for the many-sorted case. The main idea in the proposal...

  12. Gender Sorting across K-12 Schools in the United States

    Science.gov (United States)

    Long, Mark C.; Conger, Dylan

    2013-01-01

    This article documents evidence of nonrandom gender sorting across K-12 schools in the United States. The sorting exists among coed schools and at all grade levels, and it is highest in the secondary school grades. We observe some gender sorting across school sectors and types: for instance, males are slightly underrepresented in private schools…

  13. Transition dipole coupling modeling of optical activity enhancements in macromolecular protein systems

    Czech Academy of Sciences Publication Activity Database

    Průša, Jiří; Bouř, Petr

    2018-01-01

    Roč. 30, č. 1 (2018), s. 55-64 ISSN 0899-0042 R&D Projects: GA ČR GA15-09072S; GA MŠk(CZ) LTC17012 Institutional support: RVO:61388963 Keywords : optical activity * vibrational circular dichroism * protein fibrils Subject RIV: BO - Biophysics OBOR OECD: Biophysics Impact factor: 1.956, year: 2016

  14. Derivation of a regional active-optical reflectance sensor corn algorithm

    Science.gov (United States)

    Active-optical reflectance sensor (AORS) algorithms developed for in-season corn (Zea mays L.) N management have traditionally been derived using sub-regional scale information. However, studies have shown these previously developed AORS algorithms are not consistently accurate when used on a region...

  15. An optical tweezer-based study of antimicrobial activity of silver ...

    Indian Academy of Sciences (India)

    This is achieved by monitoring the fluctuations of an optically trapped polystyrene bead immersed in it. Examining the changes in the fluctuation pattern of the bead with time provides an accurate characterization of the reduction in the microbial activity. Here, we report on the effect of addition of silver nanoparticles on ...

  16. Synthesis and aggregation study of optically active tetra-β- [(S)-2 ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. The optically active tetra-β-[(S)-2-octanyloxy]-substituted copper and nickel phthalocyanines ... layer was washed by 100 mL water and dried with ... roform as mobile phase to give pure blue solid 4a: 2⋅26 g ... from the reaction mixtures by extraction with chlo- ... bonding with chiral carbon), 2⋅01–0⋅88 (H bonding.

  17. InP based lasers and optical amplifiers with wire-/dot-like active regions

    DEFF Research Database (Denmark)

    Reithmaier, J. P.; Somers, A.; Deubert, S.

    2005-01-01

    Long wavelength lasers and semiconductor optical amplifiers based on InAs quantum wire/dot-like active regions were developed on InP substrates dedicated to cover the extended telecommunication wavelength range between 1.4 - 1.65 mm. In a brief overview different technological approaches will be ...

  18. Monitoring of zwitterionic proline and alanine conformational space by raman optical activity

    Czech Academy of Sciences Publication Activity Database

    Kapitán, Josef; Bouř, Petr; Baumruk, V.

    2005-01-01

    Roč. 12, č. 1 (2005), s. 30 ISSN 1211-5894. [Meeting of Structural Biologists /4./. 10.03.2005-21.03.2005, Nové Hrady] Institutional research plan: CEZ:AV0Z40550506 Keywords : proline * Raman optical activity Subject RIV: CF - Physical ; Theoretical Chemistry

  19. Novel Chiroptical Analysis of Hemoglobin by Surface Enhanced Resonance Raman Optical Activity Spectroscopy

    DEFF Research Database (Denmark)

    Brazhe, Nadezda; Brazhe, Alexey; Sosnovtseva, Olga

    2010-01-01

    The metalloprotein hemoglobin (Hb) was studied using surface enhanced resonance Raman spectroscopy (SERRS) and surface enhanced resonance Raman optical activity (SERROA). The SERROA results are analyzed and compared with the SERRS, and the later to the resonance Raman (RRS) performed on Hb...

  20. Active Learning of Geometrical Optics in High School: The ALOP Approach

    Science.gov (United States)

    Alborch, Alejandra; Pandiella, Susana; Benegas, Julio

    2017-01-01

    A group comparison experiment of two high school classes with pre and post instruction testing has been carried out to study the suitability and advantages of using the active learning of optics and photonics (ALOP) curricula in high schools of developing countries. Two parallel, mixed gender, 12th grade classes of a high school run by the local…

  1. Nonplanar Tertiary Amides in Rigid Chiral Tricyclic Dilactams. Peptide Group Distortions and Vibrational Optical Activity

    Czech Academy of Sciences Publication Activity Database

    Pazderková, Markéta; Profant, V.; Hodačová, J.; Šebestík, Jaroslav; Pazderka, T.; Novotná, P.; Urbanová, M.; Šafařík, Martin; Buděšínský, Miloš; Tichý, Miloš; Bednárová, Lucie; Baumruk, V.; Maloň, Petr

    2013-01-01

    Roč. 117, č. 33 (2013), s. 9626-9642 ISSN 1520-6106 R&D Projects: GA ČR GAP205/10/1276 Institutional support: RVO:61388963 Keywords : spirodilactams * amide bond * vibrational circular dichroism * non-planarity * Raman optical activity Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.377, year: 2013

  2. Mosher Amides: Determining the Absolute Stereochemistry of Optically-Active Amines

    Science.gov (United States)

    Allen, Damian A.; Tomaso, Anthony E., Jr.; Priest, Owen P.; Hindson, David F.; Hurlburt, Jamie L.

    2008-01-01

    The use of chiral reagents for the derivatization of optically-active amines and alcohols for the purpose of determining their enantiomeric purity or absolute configuration is a tool used by many chemists. Among the techniques used, Mosher's amide and Mosher's ester analyses are among the most reliable and one of the most often used. Despite this,…

  3. Detection of Molecular Chirality by Induced Resonance Raman Optical Activity in Europium Complexes

    Czech Academy of Sciences Publication Activity Database

    Yamamoto, Shigeki; Bouř, Petr

    2012-01-01

    Roč. 51, č. 44 (2012), s. 11058-11061 ISSN 1433-7851 R&D Projects: GA MŠk(CZ) LH11033; GA ČR GAP208/11/0105 Institutional support: RVO:61388963 Keywords : europium * complexes * raman optical activity * resonance Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 13.734, year: 2012

  4. In situ beamline analysis and correction of active optics.

    Science.gov (United States)

    Sutter, John; Alcock, Simon; Sawhney, Kawal

    2012-11-01

    At the Diamond Light Source, pencil-beam measurements have enabled long-wavelength slope errors on X-ray mirror surfaces to be examined under ultra-high vacuum and beamline mounting without the need to remove the mirror from the beamline. For an active mirror an automated procedure has been implemented to calculate the actuator settings that optimize its figure. More recently, this in situ pencil-beam method has been applied to additional uses for which ex situ measurements would be inconvenient or simply impossible. First, it has been used to check the stability of the slope errors of several bimorph mirrors at intervals of several weeks or months. Then, it also proved useful for the adjustment of bender and sag compensation actuators on mechanically bent mirrors. Fits to the bending of ideal beams have been performed on the slope errors of a mechanically bent mirror in order to distinguish curvatures introduced by the bending actuators from gravitational distortion. Application of the optimization procedure to another mechanically bent mirror led to an improvement of its sag compensation mechanism.

  5. Developments of a bonding technique for optical materials by a surface activation method

    International Nuclear Information System (INIS)

    Sugiyama, Akira; Oda, Tomohiro; Abe, Tomoyuki; Kusunoki, Isao

    2007-01-01

    We have been developing a pair of sample holder used for optics in the surface activation bonding equipment. The holder can adjust the relative position of samples in the order of sub mm. To study the degree of dislocation appearing crystal surface activated by a fast atomic beam, irradiated sapphire crystals were examined by RBS, XPS, and AFM analysis. The heat treatment recovered the surface roughness of irradiated sapphire when the heating temperature reached at 1573 K. (author)

  6. Optically and biologically active mussel protein-coated double-walled carbon nanotubes.

    Science.gov (United States)

    Jung, Yong Chae; Muramatsu, Hiroyuki; Fujisawa, Kazunori; Kim, Jin Hee; Hayashi, Takuya; Kim, Yoong Ahm; Endo, Morinobu; Terrones, Mauricio; Dresselhaus, Mildred S

    2011-12-02

    A method of dispersing strongly bundled double-walled carbon nanotubes (DWNTs) via a homogeneous coating of mussel protein in an aqueous solution is presented. Optical activity, mechanical strength, as well as electrical conductivity coming from the nanotubes and the versatile biological activity from the mussel protein make mussel-coated DWNTs promising as a multifunctional scaffold and for anti-fouling materials. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Using pico-LCoS SLMs for high speed cell sorting

    DEFF Research Database (Denmark)

    Bañas, Andrew Rafael; Aabo, Thomas; Palima, Darwin

    2012-01-01

    We propose the use of consumer pico projectors as cost effective spatial light modulators in cell sorting applications. The matched filtering Generalized Phase Contrast (mGPC) beam shaping method is used to produce high intensity optical spots for trapping and catapulting cells. A pico projector......’s liquid crystal on silicon (LCoS) chip was used as a binary phase spatial light modulator (SLM) wherein correlation target patterns are addressed. Experiments using the binary LCoS phase SLM with a fabricated Pyrex matched filter demonstrate the generation of intense optical spots that can potentially...... be used for cell sorting. Numerical studies also show mGPC’s robustness to phase aberrations in the LCoS device, and its ability to outperform a top hat beam with the same power....

  8. Improved method and apparatus for electrostatically sorting biological cells. [DOE patent application

    Science.gov (United States)

    Merrill, J.T.

    An improved method of sorting biological cells in a conventional cell sorter apparatus includes generating a fluid jet containing cells to be sorted, measuring the distance between the centers of adjacent droplets in a zone thereof defined at the point where the fluid jet separates into descrete droplets, setting the distance between the center of a droplet in said separation zone and the position along said fluid jet at which the cell is optically sensed for specific characteristics to be an integral multiple of said center-to-center distance, and disabling a charger from electrically charging a specific droplet if a cell is detected by the optical sensor in a position wherein it will be in the neck area between droplets during droplet formation rather than within a predetermined distance from the droplet center.

  9. Optical Activation of Germanium Plasmonic Antennas in the Mid-Infrared

    Science.gov (United States)

    Fischer, Marco P.; Schmidt, Christian; Sakat, Emilie; Stock, Johannes; Samarelli, Antonio; Frigerio, Jacopo; Ortolani, Michele; Paul, Douglas J.; Isella, Giovanni; Leitenstorfer, Alfred; Biagioni, Paolo; Brida, Daniele

    2016-07-01

    Impulsive interband excitation with femtosecond near-infrared pulses establishes a plasma response in intrinsic germanium structures fabricated on a silicon substrate. This direct approach activates the plasmonic resonance of the Ge structures and enables their use as optical antennas up to the mid-infrared spectral range. The optical switching lasts for hundreds of picoseconds until charge recombination redshifts the plasma frequency. The full behavior of the structures is modeled by the electrodynamic response established by an electron-hole plasma in a regular array of antennas.

  10. Broadband Optical Active Waveguides Written by Femtosecond Laser Pulses in Lithium Fluoride

    International Nuclear Information System (INIS)

    Chiamenti, Ismael; Costa, Larissa N. da; Kalinowski, Hypolito J.; Bonfigli, Francesca; Montereali, Rosa Maria; Gomes Anderson, S. L.

    2014-01-01

    Broadband waveguiding through light-emitting strips directly written in a blank lithium fluoride crystal with a femtosecond laser is reported. Light guiding was observed at several optical wavelengths, from blue, 458 nm, to near-infrared, at 1550 nm. Visible photoluminescence spectra of the optically active F 2 and F 3 + color centers produced by the fs laser writing process were measured. The wavelength-dependent refractive index increase was estimated to be in the order of 10 −3 −10 −4 in the visible and near-infrared spectral intervals, which is consistent with the stable formation of point defects in LiF

  11. Broadband Optical Active Waveguides Written by Femtosecond Laser Pulses in Lithium Fluoride

    Science.gov (United States)

    Ismael, Chiamenti; Francesca, Bonfigli; Anderson, S. L. Gomes; Rosa, Maria Montereali; Larissa, N. da Costa; Hypolito, J. Kalinowski

    2014-01-01

    Broadband waveguiding through light-emitting strips directly written in a blank lithium fluoride crystal with a femtosecond laser is reported. Light guiding was observed at several optical wavelengths, from blue, 458 nm, to near-infrared, at 1550 nm. Visible photoluminescence spectra of the optically active F2 and F3+ color centers produced by the fs laser writing process were measured. The wavelength-dependent refractive index increase was estimated to be in the order of 10-3-10-4 in the visible and near-infrared spectral intervals, which is consistent with the stable formation of point defects in LiF.

  12. Active Figure Control Effects on Mounting Strategy for X-Ray Optics

    Science.gov (United States)

    Kolodziejczak, Jeffery J.; Atkins, Carolyn; Roche, Jacqueline M.; ODell, Stephen L.; Ramsey, Brian D.; Elsner, Ronald F.; Weisskopf, Martin C.; Gubarev, Mikhail V.

    2014-01-01

    As part of ongoing development efforts at MSFC, we have begun to investigate mounting strategies for highly nested xray optics in both full-shell and segmented configurations. The analytical infrastructure for this effort also lends itself to investigation of active strategies. We expect that a consequence of active figure control on relatively thin substrates is that errors are propagated to the edges, where they might affect the effective precision of the mounting points. Based upon modeling, we describe parametrically, the conditions under which active mounts are preferred over fixed ones, and the effect of active figure corrections on the required number, locations, and kinematic characteristics of mounting points.

  13. Damage recovery and optical activity in europium implanted wide gap oxides

    International Nuclear Information System (INIS)

    Alves, E.; Marques, C.; Franco, N.; Alves, L.C.; Peres, M.; Soares, M.J.; Monteiro, T.

    2010-01-01

    In this study we compare and discuss the defects and optical behaviour of sapphire and magnesium oxide single crystals implanted at room temperature with different fluences (1 x 10 15 -1 x 10 16 cm -2 ) of europium ions. Rutherford backscattering channelling shows that for fluences above 5 x 10 15 cm -2 the surface disorder level in the Al-sublattice reaches the random level. Implantation damage recovers fast for annealing in oxidizing atmosphere but even for the highest fluence we recover almost completely all the damage after annealing at 1300 o C, independently of the annealing environment (reducing or oxidizing). Annealing above 1000 o C promotes the formation of Eu 2 O 3 in the samples with higher concentration of Eu. The optical activation of the rare earth ions at room temperature was observed after annealing at 800 o C by photoluminescence and ionoluminescence. In Al 2 O 3 lattice the highest intensity line of the Eu 3+ ions corresponds to the forced electric dipole 5 D 0 → 7 F 2 transition that occurs ∼616 nm. For the MgO samples the Eu 3+ optical activation was also achieved after implantation with different fluences. Here, the lanthanide recombination is dominated by the magnetic dipole 5 D 0 → 7 F 1 transition near by 590 nm commonly observed for samples were Eu 3+ is placed in a high symmetry local site. The results clearly demonstrate the possibility to get Eu incorporated in optical active regular lattice sites in wide gap oxides.

  14. Isotope effect of optical activity measurements on L-α-alanine

    International Nuclear Information System (INIS)

    Darge, W.; Laczko, I.; Thiemann, W.

    1976-01-01

    If an optically active organic substance is labelled in the chirality center with another isotopic species (such as 15 N for 14 N) a pronounced variation of rotatory power is predicted. It was tried to varify this idea experimentally on L-α-alanine and found an isotope effect in ORD (optical rotatory dispersion). The magnitude of the rotation is mainly dependent on the pH of the solvent. The ratio of the optical activity alanine- 14 N/alanine- 15 N is about 1.02. It can be seen that the ratios of the molecular rotations are consistently lower than the corresponding ratios of the specific rotations. This is of course due to the fact that the molecular mass 15 M is larger than 14 M. This means tthat the mass difference is already taken into account so that the ratio of the molecular rotations could be defined as the ''net'' isotope effect in the ORDs of 15 N-substitued alanine. From the fact the ORD is different for the isotope-substitued alanine, one can reasonably assume that the absorption coefficient is also different. This leads to speculations about certain problems in the chemical evolution of the biosphere, such as the origin of optical activity. (T.G.)

  15. High-power fiber optic cable with integrated active sensors for live process monitoring

    Science.gov (United States)

    Blomster, Ola; Blomqvist, Mats; Bergstrand, Hans; Pålsson, Magnus

    2012-03-01

    In industrial applications using high-brilliance lasers at power levels up to and exceeding 20 kW and similarly direct diode lasers of 10 kW, there is an increasing demand to continuously monitor component status even in passive components such as fiber-optic cables. With fiber-optic cables designed according to the European Automotive Industry fiber standard interface there is room for integrating active sensors inside the connectors. In this paper we present the integrated active sensors in the new Optoskand QD fiber-optic cable designed to handle extreme levels of power losses, and how these sensors can be employed in industrial manufacturing. The sensors include photo diodes for detection of scattered light inside the fiber connector, absolute temperature of the fiber connector, difference in temperature of incoming and outgoing cooling water, and humidity measurement inside the fiber connector. All these sensors are connected to the fiber interlock system, where interlock break enable functions can be activated when measured signals are higher than threshold levels. It is a very fast interlock break system as the control of the signals is integrated in the electronics inside the fiber connector. Also, since all signals can be logged it is possible to evaluate what happened inside the connector before the interlock break instance. The communication to the fiber-optic connectors is via a CAN interface. Thus it is straightforward to develop the existing laser host control to also control the CAN-messages from the QD sensors.

  16. Cache-Aware and Cache-Oblivious Adaptive Sorting

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Fagerberg, Rolf; Moruz, Gabriel

    2005-01-01

    Two new adaptive sorting algorithms are introduced which perform an optimal number of comparisons with respect to the number of inversions in the input. The first algorithm is based on a new linear time reduction to (non-adaptive) sorting. The second algorithm is based on a new division protocol...... for the GenericSort algorithm by Estivill-Castro and Wood. From both algorithms we derive I/O-optimal cache-aware and cache-oblivious adaptive sorting algorithms. These are the first I/O-optimal adaptive sorting algorithms....

  17. Quantum computer based on activated dielectric nanoparticles selectively interacting with short optical pulses

    International Nuclear Information System (INIS)

    Gadomskii, Oleg N; Kharitonov, Yu Ya

    2004-01-01

    The operation principle of a quantum computer is proposed based on a system of dielectric nanoparticles activated with two-level atoms - cubits, in which electric dipole transitions are excited by short intense optical pulses. It is proved that the logical operation (logical operator) CNOT (controlled NOT) is performed by means of time-dependent transfer of quantum information over 'long' (of the order of 10 4 nm) distances between spherical nanoparticles owing to the delayed interaction between them in the optical radiation field. It is shown that one-cubit and two-cubit logical operators required for quantum calculations can be realised by selectively exciting dielectric particles with short optical pulses. (quantum calculations)

  18. Recent research activities on functional ceramics for insulator, breeder and optical sensing systems in fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, S., E-mail: nagata@imr.tohoku.ac.jp [Institute for Materials Research, Tohoku University, Sendai (Japan); Katsui, H.; Hoshi, K. [Institute for Materials Research, Tohoku University, Sendai (Japan); Tsuchiya, B. [Meijo University, Faculty of Science and Technology, Nagoya (Japan); Toh, K. [J-PARC Center Japan Atomic Energy Agency, Tokai (Japan); Zhao, M.; Shikama, T. [Institute for Materials Research, Tohoku University, Sendai (Japan); Hodgson, E.R. [Euratom/CIEMAT Fusion Association, Madrid (Spain)

    2013-11-15

    The paper presents a brief overview of current research activities on functional ceramic materials for insulating components, tritium breeder and optical sensing systems, mainly carried out at Institute for Materials Research (IMR), Tohoku University. Topics include recent experimental results related to the electrical degradation and optical changes in typical oxide ceramics (e.g. Al{sub 2}O{sub 3} and SiO{sub 2}) concerning radiolytic effects. Hydrogen effects on the electrical conductivity in the Perovskite-type oxide ceramics and the interaction between hydrogen and irradiation induced defects in ternary Li oxides used as breeder materials, were dynamically observed under the irradiation environment. Further attention is focused on several challenging qualifications required for an advanced sensing system using optical characteristics (e.g., thermoluminescence in SiO{sub 2} core fiber, neutron-induced long lasting emission from oxides doped with rare-earth elements, and gasochromic coloration phenomenon of WO{sub 3})

  19. Online sorting of recovered wood waste by automated XRF-technology: part II. Sorting efficiencies.

    Science.gov (United States)

    Hasan, A Rasem; Solo-Gabriele, Helena; Townsend, Timothy

    2011-04-01

    Sorting of waste wood is an important process practiced at recycling facilities in order to detect and divert contaminants from recycled wood products. Contaminants of concern include arsenic, chromium and copper found in chemically preserved wood. The objective of this research was to evaluate the sorting efficiencies of both treated and untreated parts of the wood waste stream, and metal (As, Cr and Cu) mass recoveries by the use of automated X-ray fluorescence (XRF) systems. A full-scale system was used for experimentation. This unit consisted of an XRF-detection chamber mounted on the top of a conveyor and a pneumatic slide-way diverter which sorted wood into presumed treated and presumed untreated piles. A randomized block design was used to evaluate the operational conveyance parameters of the system, including wood feed rate and conveyor belt speed. Results indicated that online sorting efficiencies of waste wood by XRF technology were high based on number and weight of pieces (70-87% and 75-92% for treated wood and 66-97% and 68-96% for untreated wood, respectively). These sorting efficiencies achieved mass recovery for metals of 81-99% for As, 75-95% for Cu and 82-99% of Cr. The incorrect sorting of wood was attributed almost equally to deficiencies in the detection and conveyance/diversion systems. Even with its deficiencies, the system was capable of producing a recyclable portion that met residential soil quality levels established for Florida, for an infeed that contained 5% of treated wood. Copyright © 2010 Elsevier Ltd. All rights reserved.

  20. CHARACTERIZING THE OPTICAL VARIABILITY OF BRIGHT BLAZARS: VARIABILITY-BASED SELECTION OF FERMI ACTIVE GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    Ruan, John J.; Anderson, Scott F.; MacLeod, Chelsea L.; Becker, Andrew C.; Davenport, James R. A.; Ivezić, Željko; Burnett, T. H.; Kochanek, Christopher S.; Plotkin, Richard M.; Sesar, Branimir; Stuart, J. Scott

    2012-01-01

    We investigate the use of optical photometric variability to select and identify blazars in large-scale time-domain surveys, in part to aid in the identification of blazar counterparts to the ∼30% of γ-ray sources in the Fermi 2FGL catalog still lacking reliable associations. Using data from the optical LINEAR asteroid survey, we characterize the optical variability of blazars by fitting a damped random walk model to individual light curves with two main model parameters, the characteristic timescales of variability τ, and driving amplitudes on short timescales σ-circumflex. Imposing cuts on minimum τ and σ-circumflex allows for blazar selection with high efficiency E and completeness C. To test the efficacy of this approach, we apply this method to optically variable LINEAR objects that fall within the several-arcminute error ellipses of γ-ray sources in the Fermi 2FGL catalog. Despite the extreme stellar contamination at the shallow depth of the LINEAR survey, we are able to recover previously associated optical counterparts to Fermi active galactic nuclei with E ≥ 88% and C = 88% in Fermi 95% confidence error ellipses having semimajor axis r < 8'. We find that the suggested radio counterpart to Fermi source 2FGL J1649.6+5238 has optical variability consistent with other γ-ray blazars and is likely to be the γ-ray source. Our results suggest that the variability of the non-thermal jet emission in blazars is stochastic in nature, with unique variability properties due to the effects of relativistic beaming. After correcting for beaming, we estimate that the characteristic timescale of blazar variability is ∼3 years in the rest frame of the jet, in contrast with the ∼320 day disk flux timescale observed in quasars. The variability-based selection method presented will be useful for blazar identification in time-domain optical surveys and is also a probe of jet physics.

  1. Ore sorting using natural gamma radiation

    International Nuclear Information System (INIS)

    Clark, G.J.; Dickson, B.L.; Gray, F.E.

    1980-01-01

    A method of sorting an ore which emits natural gamma radiation is described, comprising the steps of: (a) mining the ore, (b) placing, substantially at the mining location, the sampled or mined ore on to a moving conveyor belt, (c) measuring the natural gamma emission, water content and mass of the ore while the ore is on the conveyor belt, (d) using the gamma, water content and mass measurements to determine the ore grade, and (e) directing the ore to a location characteristic of its grade when it leaves the conveyor belt

  2. Simulating Sediment Sorting of Streambed Surfaces - It's the Supply, Stupid

    Science.gov (United States)

    Wilcock, P. R.

    2014-12-01

    The grain size of the streambed surface is an integral part of the transport system because it represents the grains immediately available for transport. If the rate and size of grains entrained from the bed surface differ from that delivered to the bed surface, the bed surface grain size will change. Although this balance is intuitively clear, its implications can surprise. The relative mobility of different sizes in a mixture change as transport rates increase. At small transport rates, smaller sizes are more mobile. As transport rate increases, the transport grain size approaches that of the bed. This presents a dilemma when using flumes to simulate surface sorting and transport. When sediment is fed into a flume, the same sediment is typically used regardless of feed rate. The transport grain size remains constant at all rates, which does not match the pattern observed in the field. This operational constraint means that sediment supply is coarser than transport capacity in feed flumes, increasingly so as transport rates diminish. This imbalance drives a coarsening of the stream bed as less mobile coarse grains concentrate on the surface as the system approaches steady-state. If sediment is recirculated in a flume, sediment supply and entrainment are perfectly matched. Surface coarsening is not imposed, but does occur via kinematic sieving. The coarsening of the transport (and supply) accommodates the rate-dependent change in mobility such that the bed surface grain size does not change with transport rate. Streambed armoring depends on both the rate and grain size of sediment supply - their implications do not seem to be fully appreciated. A coarsened bed surface does not indicate sorting of the bed surface during waning flows - it can persist with active sediment supply and transport. Neither sediment feed nor sediment recirculating flumes accurately mimic natural conditions but instead represent end members that bracket the dynamics of natural streams

  3. Reduction of Aflatoxins in Apricot Kernels by Electronic and Manual Color Sorting

    Directory of Open Access Journals (Sweden)

    Rosanna Zivoli

    2016-01-01

    Full Text Available The efficacy of color sorting on reducing aflatoxin levels in shelled apricot kernels was assessed. Naturally-contaminated kernels were submitted to an electronic optical sorter or blanched, peeled, and manually sorted to visually identify and sort discolored kernels (dark and spotted from healthy ones. The samples obtained from the two sorting approaches were ground, homogenized, and analysed by HPLC-FLD for their aflatoxin content. A mass balance approach was used to measure the distribution of aflatoxins in the collected fractions. Aflatoxin B1 and B2 were identified and quantitated in all collected fractions at levels ranging from 1.7 to 22,451.5 µg/kg of AFB1 + AFB2, whereas AFG1 and AFG2 were not detected. Excellent results were obtained by manual sorting of peeled kernels since the removal of discolored kernels (2.6%–19.9% of total peeled kernels removed 97.3%–99.5% of total aflatoxins. The combination of peeling and visual/manual separation of discolored kernels is a feasible strategy to remove 97%–99% of aflatoxins accumulated in naturally-contaminated samples. Electronic optical sorter gave highly variable results since the amount of AFB1 + AFB2 measured in rejected fractions (15%–18% of total kernels ranged from 13% to 59% of total aflatoxins. An improved immunoaffinity-based HPLC-FLD method having low limits of detection for the four aflatoxins (0.01–0.05 µg/kg was developed and used to monitor the occurrence of aflatoxins in 47 commercial products containing apricot kernels and/or almonds commercialized in Italy. Low aflatoxin levels were found in 38% of the tested samples and ranged from 0.06 to 1.50 μg/kg for AFB1 and from 0.06 to 1.79 μg/kg for total aflatoxins.

  4. Neural spike sorting using iterative ICA and a deflation-based approach.

    Science.gov (United States)

    Tiganj, Z; Mboup, M

    2012-12-01

    We propose a spike sorting method for multi-channel recordings. When applied in neural recordings, the performance of the independent component analysis (ICA) algorithm is known to be limited, since the number of recording sites is much lower than the number of neurons. The proposed method uses an iterative application of ICA and a deflation technique in two nested loops. In each iteration of the external loop, the spiking activity of one neuron is singled out and then deflated from the recordings. The internal loop implements a sequence of ICA and sorting for removing the noise and all the spikes that are not fired by the targeted neuron. Then a final step is appended to the two nested loops in order to separate simultaneously fired spikes. We solve this problem by taking all possible pairs of the sorted neurons and apply ICA only on the segments of the signal during which at least one of the neurons in a given pair was active. We validate the performance of the proposed method on simulated recordings, but also on a specific type of real recordings: simultaneous extracellular-intracellular. We quantify the sorting results on the extracellular recordings for the spikes that come from the neurons recorded intracellularly. The results suggest that the proposed solution significantly improves the performance of ICA in spike sorting.

  5. Distinct forms of mitochondrial TOM-TIM supercomplexes define signal-dependent states of preprotein sorting.

    Science.gov (United States)

    Chacinska, Agnieszka; van der Laan, Martin; Mehnert, Carola S; Guiard, Bernard; Mick, David U; Hutu, Dana P; Truscott, Kaye N; Wiedemann, Nils; Meisinger, Chris; Pfanner, Nikolaus; Rehling, Peter

    2010-01-01

    Mitochondrial import of cleavable preproteins occurs at translocation contact sites, where the translocase of the outer membrane (TOM) associates with the presequence translocase of the inner membrane (TIM23) in a supercomplex. Different views exist on the mechanism of how TIM23 mediates preprotein sorting to either the matrix or inner membrane. On the one hand, two TIM23 forms were proposed, a matrix transport form containing the presequence translocase-associated motor (PAM; TIM23-PAM) and a sorting form containing Tim21 (TIM23(SORT)). On the other hand, it was reported that TIM23 and PAM are permanently associated in a single-entity translocase. We have accumulated distinct transport intermediates of preproteins to analyze the translocases in their active, preprotein-carrying state. We identified two different forms of active TOM-TIM23 supercomplexes, TOM-TIM23(SORT) and TOM-TIM23-PAM. These two supercomplexes do not represent separate pathways but are in dynamic exchange during preprotein translocation and sorting. Depending on the signals of the preproteins, switches between the different forms of supercomplex and TIM23 are required for the completion of preprotein import.

  6. OPTICAL STUDIES OF PENICILLIN GROUP IN RELATION TO THEIR MEDICAL ACTIVITY

    Directory of Open Access Journals (Sweden)

    R. Jeevan Kumar

    2017-11-01

    Full Text Available The study of Medical activity of antibiotics is gaining momentum now a days owing to the importance of their curative values.  The Medical Activity correlated to molecular interactions,can be studied by various physical techniques, at present optical methods like Refractometry and Polarization are used to study the activity of a few antibiotics like Penicillin.  The Refractive Indices Mean Molecular Polarizability Diamagnetic Susceptibilities and Electron Ionisation Cross Section are interpreted in terms of dosages and the toxic effects if any due to over dosages are discussed critically.

  7. Performance evaluation of PCA-based spike sorting algorithms.

    Science.gov (United States)

    Adamos, Dimitrios A; Kosmidis, Efstratios K; Theophilidis, George

    2008-09-01

    Deciphering the electrical activity of individual neurons from multi-unit noisy recordings is critical for understanding complex neural systems. A widely used spike sorting algorithm is being evaluated for single-electrode nerve trunk recordings. The algorithm is based on principal component analysis (PCA) for spike feature extraction. In the neuroscience literature it is generally assumed that the use of the first two or most commonly three principal components is sufficient. We estimate the optimum PCA-based feature space by evaluating the algorithm's performance on simulated series of action potentials. A number of modifications are made to the open source nev2lkit software to enable systematic investigation of the parameter space. We introduce a new metric to define clustering error considering over-clustering more favorable than under-clustering as proposed by experimentalists for our data. Both the program patch and the metric are available online. Correlated and white Gaussian noise processes are superimposed to account for biological and artificial jitter in the recordings. We report that the employment of more than three principal components is in general beneficial for all noise cases considered. Finally, we apply our results to experimental data and verify that the sorting process with four principal components is in agreement with a panel of electrophysiology experts.

  8. Spike sorting based upon machine learning algorithms (SOMA).

    Science.gov (United States)

    Horton, P M; Nicol, A U; Kendrick, K M; Feng, J F

    2007-02-15

    We have developed a spike sorting method, using a combination of various machine learning algorithms, to analyse electrophysiological data and automatically determine the number of sampled neurons from an individual electrode, and discriminate their activities. We discuss extensions to a standard unsupervised learning algorithm (Kohonen), as using a simple application of this technique would only identify a known number of clusters. Our extra techniques automatically identify the number of clusters within the dataset, and their sizes, thereby reducing the chance of misclassification. We also discuss a new pre-processing technique, which transforms the data into a higher dimensional feature space revealing separable clusters. Using principal component analysis (PCA) alone may not achieve this. Our new approach appends the features acquired using PCA with features describing the geometric shapes that constitute a spike waveform. To validate our new spike sorting approach, we have applied it to multi-electrode array datasets acquired from the rat olfactory bulb, and from the sheep infero-temporal cortex, and using simulated data. The SOMA sofware is available at http://www.sussex.ac.uk/Users/pmh20/spikes.

  9. Sorting waste - A question of good will

    CERN Multimedia

    TS Department - FM Group

    2006-01-01

    In order to minimise waste-sorting costs, CERN provides two types of container at the entrance of buildings: a green plastic container for paper/cardboard and a metal container for household-type waste. We regret that recently there has been a significant decrease in the extent to which these types of waste are sorted, for example green containers have been found to hold assorted waste such as cardboard boxes filled with polystyrene, bubble-wrap or even plastic bottles, yoghurt pots, etc. Checks have shown that this 'non-compliant' waste does not come from the rubbish bins emptied by the cleaners but is deposited there directly by inconsiderate users. During the months of October and November alone, for example, only 15% of the waste from the paper/cardboard containers was recycled and the remaining 85% had to be incinerated, which entails a high cost for CERN. You should note that once an item of non-compliant waste is found in a green container its contents are immediately sent as waste to be incinerated ...

  10. Efficiency at Sorting Cards in Compressed Air

    Science.gov (United States)

    Poulton, E. C.; Catton, M. J.; Carpenter, A.

    1964-01-01

    At a site where compressed air was being used in the construction of a tunnel, 34 men sorted cards twice, once at normal atmospheric pressure and once at 3½, 2½, or 2 atmospheres absolute pressure. An additional six men sorted cards twice at normal atmospheric pressure. When the task was carried out for the first time, all the groups of men performing at raised pressure were found to yield a reliably greater proportion of very slow responses than the group of men performing at normal pressure. There was reliably more variability in timing at 3½ and 2½ atmospheres absolute than at normal pressure. At 3½ atmospheres absolute the average performance was also reliably slower. When the task was carried out for the second time, exposure to 3½ atmospheres absolute pressure had no reliable effect. Thus compressed air affected performance only while the task was being learnt; it had little effect after practice. No reliable differences were found related to age, to length of experience in compressed air, or to the duration of the exposure to compressed air, which was never less than 10 minutes at 3½ atmospheres absolute pressure. PMID:14180485

  11. PACMan to Help Sort Hubble Proposals

    Science.gov (United States)

    Kohler, Susanna

    2017-04-01

    Every year, astronomers submit over a thousand proposals requesting time on the Hubble Space Telescope (HST). Currently, humans must sort through each of these proposals by hand before sending them off for review. Could this burden be shifted to computers?A Problem of VolumeAstronomer Molly Peeples gathered stats on the HST submissions sent in last week for the upcoming HST Cycle 25 (the deadline was Friday night), relative to previous years. This years proposal round broke the record, with over 1200 proposals submitted in total for Cycle 25. [Molly Peeples]Each proposal cycle for HST time attracts on the order of 1100 proposals accounting for far more HST time than is available. The proposals are therefore carefully reviewed by around 150 international members of the astronomy community during a six-month process to select those with the highest scientific merit.Ideally, each proposal will be read by reviewers that have scientific expertise relevant to the proposal topic: if a proposal requests HST time to study star formation, for instance, then the reviewers assigned to it should have research expertise in star formation.How does this matching of proposals to reviewers occur? The current method relies on self-reported categorization of the submitted proposals. This is unreliable, however; proposals are often mis-categorized by submitters due to misunderstanding or ambiguous cases.As a result, the Science Policies Group at the Space Telescope Science Institute (STScI) which oversees the review of HST proposals must go through each of the proposals by hand and re-categorize them. The proposals are then matched to reviewers with self-declared expertise in the same category.With the number of HST proposals on the rise and the expectation that the upcoming James Webb Space Telescope (JWST) will elicit even more proposals for time than Hubble scientists at STScI and NASA are now asking: could the human hours necessary for this task be spared? Could a computer program

  12. Bacterial lipoproteins; biogenesis, sorting and quality control.

    Science.gov (United States)

    Narita, Shin-Ichiro; Tokuda, Hajime

    2017-11-01

    Bacterial lipoproteins are a subset of membrane proteins localized on either leaflet of the lipid bilayer. These proteins are anchored to membranes through their N-terminal lipid moiety attached to a conserved Cys. Since the protein moiety of most lipoproteins is hydrophilic, they are expected to play various roles in a hydrophilic environment outside the cytoplasmic membrane. Gram-negative bacteria such as Escherichia coli possess an outer membrane, to which most lipoproteins are sorted. The Lol pathway plays a central role in the sorting of lipoproteins to the outer membrane after lipoprotein precursors are processed to mature forms in the cytoplasmic membrane. Most lipoproteins are anchored to the inner leaflet of the outer membrane with their protein moiety in the periplasm. However, recent studies indicated that some lipoproteins further undergo topology change in the outer membrane, and play critical roles in the biogenesis and quality control of the outer membrane. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. PTP1B targets the endosomal sorting machinery

    DEFF Research Database (Denmark)

    Stuible, Matthew; Abella, Jasmine V; Feldhammer, Matthew

    2010-01-01

    Dephosphorylation and endocytic down-regulation are distinct processes that together control the signaling output of a variety of receptor tyrosine kinases (RTKs). PTP1B can directly dephosphorylate several RTKs, but it can also promote activation of downstream pathways through largely unknown...... mechanisms. These positive signaling functions likely contribute to the tumor-promoting effect of PTP1B in mouse cancer models. Here, we have identified STAM2, an endosomal protein involved in sorting activated RTKs for lysosomal degradation, as a substrate of PTP1B. PTP1B interacts with STAM2 at defined...... phosphotyrosine sites, and knockdown of PTP1B expression augments STAM2 phosphorylation. Intriguingly, manipulating the expression and phosphorylation state of STAM2 did not have a general effect on epidermal growth factor (EGF)-induced EGF receptor trafficking, degradation, or signaling. Instead, phosphorylated...

  14. Vertical sorting and the morphodynamics of bed form-dominated rivers : a sorting evolution model

    NARCIS (Netherlands)

    Blom, Astrid; Ribberink, Jan S.; Parker, Gary

    2008-01-01

    Existing sediment continuity models for nonuniform sediment suffer from a number of shortcomings, as they fail to describe vertical sorting fluxes other than through net aggradation or degradation of the bed and are based on a discrete representation of the bed material interacting with the flow. We

  15. Characterizing the Optical Variability of Bright Blazars: Variability-based Selection of Fermi Active Galactic Nuclei

    Science.gov (United States)

    Ruan, John J.; Anderson, Scott F.; MacLeod, Chelsea L.; Becker, Andrew C.; Burnett, T. H.; Davenport, James R. A.; Ivezić, Željko; Kochanek, Christopher S.; Plotkin, Richard M.; Sesar, Branimir; Stuart, J. Scott

    2012-11-01

    We investigate the use of optical photometric variability to select and identify blazars in large-scale time-domain surveys, in part to aid in the identification of blazar counterparts to the ~30% of γ-ray sources in the Fermi 2FGL catalog still lacking reliable associations. Using data from the optical LINEAR asteroid survey, we characterize the optical variability of blazars by fitting a damped random walk model to individual light curves with two main model parameters, the characteristic timescales of variability τ, and driving amplitudes on short timescales \\hat{\\sigma }. Imposing cuts on minimum τ and \\hat{\\sigma } allows for blazar selection with high efficiency E and completeness C. To test the efficacy of this approach, we apply this method to optically variable LINEAR objects that fall within the several-arcminute error ellipses of γ-ray sources in the Fermi 2FGL catalog. Despite the extreme stellar contamination at the shallow depth of the LINEAR survey, we are able to recover previously associated optical counterparts to Fermi active galactic nuclei with E >= 88% and C = 88% in Fermi 95% confidence error ellipses having semimajor axis r beaming. After correcting for beaming, we estimate that the characteristic timescale of blazar variability is ~3 years in the rest frame of the jet, in contrast with the ~320 day disk flux timescale observed in quasars. The variability-based selection method presented will be useful for blazar identification in time-domain optical surveys and is also a probe of jet physics.

  16. Optical filter finesses enhancement based on nested coupled cavities and active medium

    Science.gov (United States)

    Adib, George A.; Sabry, Yasser M.; Khalil, Diaa

    2016-04-01

    Optical filters with relatively large FSR and narrow linewidth are simultaneously needed for different applications. The ratio between the FSR and the 3-dB linewidth is given by finesse of the filter, which is solely determined by the different energy loss mechanisms limited by the technology advancement. In this work, we present a novel coupled-cavity configuration embedding an optical filter and a gain medium; allowing an overall finesse enhancement and simultaneous FSR and 3-dB linewidth engineering beyond the technological limits of the filter fabrication method. The configuration consists of two resonators. An active ring resonator comprises an optical gain medium and a passive resonator. In one configuration, the optical filter is the passive resonator itself. In a second configuration, the passive resonator is another ring resonator that embeds the optical filter. The presented configurations using a semiconductor optical amplifier are applied one time to a mechanically Fabry-Perot filter in the first presented configuration; and a second time to a fiber ring filter in the second presented configuration. The mechanical filter has an original 3-dB linewidth of 1nm and an FSR that is larger than 100nm while the enhanced linewidth is about 0.3nm. The fiber ring filter length is 4 m and directional coupler ratios of 90/10corresponding to a 3-dBlinewidth of about 4MHz and an FSR of 47 MHz. The enhanced 3- dBlinewidth of the overall filter configuration is 200kHz, demonstrating finesse enhancement up to20 times the original finesse of the filter.

  17. Classification of Active Microwave and Passive Optical Data Based on Bayesian Theory and Mrf

    Science.gov (United States)

    Yu, F.; Li, H. T.; Han, Y. S.; Gu, H. Y.

    2012-08-01

    A classifier based on Bayesian theory and Markov random field (MRF) is presented to classify the active microwave and passive optical remote sensing data, which have demonstrated their respective advantages in inversion of surface soil moisture content. In the method, the VV, VH polarization of ASAR and all the 7 TM bands are taken as the input of the classifier to get the class labels of each pixel of the images. And the model is validated for the necessities of integration of TM and ASAR, it shows that, the total precision of classification in this paper is 89.4%. Comparing with the classification with single TM, the accuracy increase 11.5%, illustrating that synthesis of active and passive optical remote sensing data is efficient and potential in classification.

  18. CLASSIFICATION OF ACTIVE MICROWAVE AND PASSIVE OPTICAL DATA BASED ON BAYESIAN THEORY AND MRF

    Directory of Open Access Journals (Sweden)

    F. Yu

    2012-08-01

    Full Text Available A classifier based on Bayesian theory and Markov random field (MRF is presented to classify the active microwave and passive optical remote sensing data, which have demonstrated their respective advantages in inversion of surface soil moisture content. In the method, the VV, VH polarization of ASAR and all the 7 TM bands are taken as the input of the classifier to get the class labels of each pixel of the images. And the model is validated for the necessities of integration of TM and ASAR, it shows that, the total precision of classification in this paper is 89.4%. Comparing with the classification with single TM, the accuracy increase 11.5%, illustrating that synthesis of active and passive optical remote sensing data is efficient and potential in classification.

  19. Vibrational spectroscopic and non-linear optical activity studies on nicotinanilide : A DFT approach

    Science.gov (United States)

    Premkumar, S.; Jawahar, A.; Mathavan, T.; Dhas, M. Kumara; Benial, A. Milton Franklin

    2015-06-01

    The molecular structure of nicotinanilide was optimized by the DFT/B3LYP method with cc-pVTZ basis set using Gaussian 09 program. The first order hyperpolarizability of the molecule was calculated, which exhibits the higher nonlinear optical activity. The natural bond orbital analysis confirms the presence of intramolecular charge transfer and the hydrogen bonding interaction, which leads to the higher nonlinear optical activity of the molecule. The Frontier molecular orbitals analysis of the molecule shows that the delocalization of electron density occurs within the molecule. The lower energy gap indicates that the hydrogen bond formation between the charged species. The vibrational frequencies were calculated and assigned on the basis of potential energy distribution calculation using the VEDA 4.0 program and the corresponding vibrational spectra were simulated. Hence, the nicotinanilide molecule can be a good candidate for second-order NLO material.

  20. Circularly polarized infrared and visible sum-frequency-generation spectroscopy: Vibrational optical activity measurement

    International Nuclear Information System (INIS)

    Cheon, Sangheon; Cho, Minhaeng

    2005-01-01

    Vibrational optical activity spectroscopies utilizing either circularly polarized ir or circularly polarized visible beams were theoretically investigated by considering the infrared and visible sum-frequency-generation (IV-SFG) schemes. In addition to the purely electric dipole-allowed chiral component of the IV-SFG susceptibility, the polarizability-electric quadrupole hyperpolarizability term also contributes to the vibrationally resonant IV-SFG susceptibility. The circular-intensity-difference signal is shown to be determined by the interferences between the all-electric dipole-allowed chiral component and the polarizability-electric-dipole or electric-dipole-electric-quadrupole Raman optical activity tensor components. The circularly polarized SFG methods are shown to be potentially useful coherent spectroscopic tools for determining absolute configurations of chiral molecules in condensed phases

  1. Ramachandran Plot for Alanine Dipeptide as Determined from Raman Optical Activity

    Czech Academy of Sciences Publication Activity Database

    Parchaňský, Václav; Kapitán, J.; Kaminský, Jakub; Šebestík, Jaroslav; Bouř, Petr

    2013-01-01

    Roč. 4, č. 16 (2013), s. 2763-2768 ISSN 1948-7185 R&D Projects: GA ČR GAP208/11/0105; GA MŠk(CZ) LH11033 Grant - others:AV ČR(CZ) M200551205; GA MŠk(CZ) LM2010005 Institutional support: RVO:61388963 Keywords : Raman optical activity * Ramachandran plot * molecular modelling Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 6.687, year: 2013

  2. The Age of Enlightenment: Evolving Opportunities in Brain Research Through Optical Manipulation of Neuronal Activity

    OpenAIRE

    Jerome, Jason; Heck, Detlef H.

    2011-01-01

    Optical manipulation of neuronal activity has rapidly developed into the most powerful and widely used approach to study mechanisms related to neuronal connectivity over a range of scales. Since the early use of single site uncaging to map network connectivity, rapid technological development of light modulation techniques has added important new options, such as fast scanning photostimulation, massively parallel control of light stimuli, holographic uncaging, and two-photon stimulation techn...

  3. Noncoherent Spectral Optical CDMA System Using 1D Active Weight Two-Code Keying Codes

    Directory of Open Access Journals (Sweden)

    Bih-Chyun Yeh

    2016-01-01

    Full Text Available We propose a new family of one-dimensional (1D active weight two-code keying (TCK in spectral amplitude coding (SAC optical code division multiple access (OCDMA networks. We use encoding and decoding transfer functions to operate the 1D active weight TCK. The proposed structure includes an optical line terminal (OLT and optical network units (ONUs to produce the encoding and decoding codes of the proposed OLT and ONUs, respectively. The proposed ONU uses the modified cross-correlation to remove interferences from other simultaneous users, that is, the multiuser interference (MUI. When the phase-induced intensity noise (PIIN is the most important noise, the modified cross-correlation suppresses the PIIN. In the numerical results, we find that the bit error rate (BER for the proposed system using the 1D active weight TCK codes outperforms that for two other systems using the 1D M-Seq codes and 1D balanced incomplete block design (BIBD codes. The effective source power for the proposed system can achieve −10 dBm, which has less power than that for the other systems.

  4. Space Active Optics: toward optimized correcting mirrors for future large spaceborne observatories

    Science.gov (United States)

    Laslandes, Marie; Hugot, Emmanuel; Ferrari, Marc; Lemaitre, Gérard; Liotard, Arnaud

    2011-10-01

    Wave-front correction in optical instruments is often needed, either to compensate Optical Path Differences, off-axis aberrations or mirrors deformations. Active optics techniques are developed to allow efficient corrections with deformable mirrors. In this paper, we will present the conception of particular deformation systems which could be used in space telescopes and instruments in order to improve their performances while allowing relaxing specifications on the global system stability. A first section will be dedicated to the design and performance analysis of an active mirror specifically designed to compensate for aberrations that might appear in future 3m-class space telescopes, due to lightweight primary mirrors, thermal variations or weightless conditions. A second section will be dedicated to a brand new design of active mirror, able to compensate for given combinations of aberrations with a single actuator. If the aberrations to be corrected in an instrument and their evolutions are known in advance, an optimal system geometry can be determined thanks to the elasticity theory and Finite Element Analysis.

  5. Semi-analytical Model for Estimating Absorption Coefficients of Optically Active Constituents in Coastal Waters

    Science.gov (United States)

    Wang, D.; Cui, Y.

    2015-12-01

    The objectives of this paper are to validate the applicability of a multi-band quasi-analytical algorithm (QAA) in retrieval absorption coefficients of optically active constituents in turbid coastal waters, and to further improve the model using a proposed semi-analytical model (SAA). The ap(531) and ag(531) semi-analytically derived using SAA model are quite different from the retrievals procedures of QAA model that ap(531) and ag(531) are semi-analytically derived from the empirical retrievals results of a(531) and a(551). The two models are calibrated and evaluated against datasets taken from 19 independent cruises in West Florida Shelf in 1999-2003, provided by SeaBASS. The results indicate that the SAA model produces a superior performance to QAA model in absorption retrieval. Using of the SAA model in retrieving absorption coefficients of optically active constituents from West Florida Shelf decreases the random uncertainty of estimation by >23.05% from the QAA model. This study demonstrates the potential of the SAA model in absorption coefficients of optically active constituents estimating even in turbid coastal waters. Keywords: Remote sensing; Coastal Water; Absorption Coefficient; Semi-analytical Model

  6. OPTICAL-ELECTRONIC SYSTEM FOR EXPRESS ANALYSIS OF ORE DRESSABILITY FOR MINERAL RAW MATERIALS BY OPTICAL METHOD

    Directory of Open Access Journals (Sweden)

    A. A. Alekhin

    2013-05-01

    Full Text Available The article deals with creation results of experimental prototype of optical-electronic complex, designed to assess ore dressability of mineral raw materials by optical sorting method.

  7. Achieving few-femtosecond time-sorting at hard X-ray free-electron lasers

    Science.gov (United States)

    Harmand, M.; Coffee, R.; Bionta, M. R.; Chollet, M.; French, D.; Zhu, D.; Fritz, D. M.; Lemke, H. T.; Medvedev, N.; Ziaja, B.; Toleikis, S.; Cammarata, M.

    2013-03-01

    Recently, few-femtosecond pulses have become available at hard X-ray free-electron lasers. Coupled with the available sub-10 fs optical pulses, investigations into few-femtosecond dynamics are not far off. However, achieving sufficient synchronization between optical lasers and X-ray pulses continues to be challenging. We report a `measure-and-sort' approach, which achieves sub-10 fs root-mean-squared (r.m.s.) error measurement at hard X-ray FELs, far beyond the 100-200 fs r.m.s. jitter limitations. This timing diagnostic, now routinely available at the Linac Coherent Light Source (LCLS), is based on ultrafast free-carrier generation in optically transparent materials. Correlation between two independent measurements enables unambiguous demonstration of ~6 fs r.m.s. error in reporting the optical/X-ray delay, with single shot error suggesting the possibility of reaching few-femtosecond resolution.

  8. Combined effects of nonparaxiality, optical activity, and walk-off on rogue wave propagation in optical fibers filled with chiral materials

    Science.gov (United States)

    Temgoua, D. D. Estelle; Tchokonte, M. B. Tchoula; Kofane, T. C.

    2018-04-01

    The generalized nonparaxial nonlinear Schrödinger (NLS) equation in optical fibers filled with chiral materials is reduced to the higher-order integrable Hirota equation. Based on the modified Darboux transformation method, the nonparaxial chiral optical rogue waves are constructed from the scalar model with modulated coefficients. We show that the parameters of nonparaxiality, third-order dispersion, and differential gain or loss term are the main keys to control the amplitude, linear, and nonlinear effects in the model. Moreover, the influence of nonparaxiality, optical activity, and walk-off effect are also evidenced under the defocusing and focusing regimes of the vector nonparaxial NLS equations with constant and modulated coefficients. Through an algorithm scheme of wider applicability on nonparaxial beam propagation methods, the most influential effect and the simultaneous controllability of combined effects are underlined, showing their properties and their potential applications in optical fibers and in a variety of complex dynamical systems.

  9. Particle Transport and Size Sorting in Bubble Microstreaming Flow

    Science.gov (United States)

    Thameem, Raqeeb; Rallabandi, Bhargav; Wang, Cheng; Hilgenfeldt, Sascha

    2014-11-01

    Ultrasonic driving of sessile semicylindrical bubbles results in powerful steady streaming flows that are robust over a wide range of driving frequencies. In a microchannel, this flow field pattern can be fine-tuned to achieve size-sensitive sorting and trapping of particles at scales much smaller than the bubble itself; the sorting mechanism has been successfully described based on simple geometrical considerations. We investigate the sorting process in more detail, both experimentally (using new parameter variations that allow greater control over the sorting) and theoretically (incorporating the device geometry as well as the superimposed channel flow into an asymptotic theory). This results in optimized criteria for size sorting and a theoretical description that closely matches the particle behavior close to the bubble, the crucial region for size sorting.

  10. On the Directly and Subdirectly Irreducible Many-Sorted Algebras

    Directory of Open Access Journals (Sweden)

    Climent Vidal J.

    2015-03-01

    Full Text Available A theorem of single-sorted universal algebra asserts that every finite algebra can be represented as a product of a finite family of finite directly irreducible algebras. In this article, we show that the many-sorted counterpart of the above theorem is also true, but under the condition of requiring, in the definition of directly reducible many-sorted algebra, that the supports of the factors should be included in the support of the many-sorted algebra. Moreover, we show that the theorem of Birkhoff, according to which every single-sorted algebra is isomorphic to a subdirect product of subdirectly irreducible algebras, is also true in the field of many-sorted algebras.

  11. Radiometric sorting of Rio Algom uranium ore

    International Nuclear Information System (INIS)

    Cristovici, M.A.

    1983-11-01

    An ore sample of about 0.2 percent uranium from Quirke Mine was subjected to radiometric sorting by Ore Sorters Limited. Approximately 60 percent of the sample weight fell within the sortable size range: -150 + 25 mm. Rejects of low uranium content ( 2 (2 counts/in 2 ) but only 7.6 percent of the ore, by weight, was discarded. At 0.8-0.9 counts/cm 2 (5-6 counts/in 2 ) a significant amount of rejects was removed (> 25 percent) but the uranium loss was unacceptably high (7.7 percent). Continuation of the testwork to improve the results is proposed by trying to extend the sortable size range and to reduce the amount of fines during crushing

  12. Using Design Sketch to Teach Bubble Sort in High School

    OpenAIRE

    Liu, Chih-Hao; Jiu, Yi-Wen; Chen, Jason Jen-Yen

    2009-01-01

    Bubble Sort is simple. Yet, it seems a bit difficult for high school students. This paper presents a pedagogical methodology: Using Design Sketch to visualize the concepts in Bubble Sort, and to evaluate how this approach assists students to understand the pseudo code of Bubble Sort. An experiment is conducted in Wu-Ling Senior High School with 250 students taking part. The statistical analysis of experimental results shows that, for relatively high abstraction concepts, such as iteration num...

  13. Nanoparticle sorting in silicon waveguide arrays

    Science.gov (United States)

    Zhao, H. T.; Zhang, Y.; Chin, L. K.; Yap, P. H.; Wang, K.; Ser, W.; Liu, A. Q.

    2017-08-01

    This paper presents the optical fractionation of nanoparticles in silicon waveguide arrays. The optical lattice is generated by evanescent coupling in silicon waveguide arrays. The hotspot size is tunable by changing the refractive index of surrounding liquids. In the experiment, 0.2-μm and 0.5-μm particles are separated with a recovery rate of 95.76%. This near-field approach is a promising candidate for manipulating nanoscale biomolecules and is anticipated to benefit the biomedical applications such as exosome purification, DNA optical mapping, cell-cell interaction, etc.

  14. Butt-joint integration of active optical components based on InP/AlInGaAsP alloys

    DEFF Research Database (Denmark)

    Kulkova, Irina; Kuznetsova, Nadezda; Semenova, Elizaveta

    2014-01-01

    We demonstrate all-active planar high quality butt-joint (BJ) integration of a QW Semiconductor Optical Amplifier (SOA) and MQW Electro-Absorption Modulator (EAM) based on an InP/AlInGaAsP platform. The degradation of the optical properties in the vicinity of ~1 μm to the BJ interface was determi...

  15. A Proposed Analytical Model for Integrated Pick-and-Sort Systems

    Directory of Open Access Journals (Sweden)

    Recep KIZILASLAN

    2013-11-01

    Full Text Available In this study we present an analytical approach for integration of order picking and sortation operations which are the most important, labour intensive and costly activity for warehouses. Main aim is to investigate order picking and sorting efficiencies under different design issues as a function of order wave size. Integrated analytical model is proposed to estimate the optimum order picking and order sortation efficiency. The model, which has been tested by simulations with different illustrative examples, calculates the optimum wave size that solves the trade-off between picking and sorting operations and makes the order picking and sortations efficiency maximum. Our model also allow system designer to predict the order picking and sorting capacity for different system configurations. This study presents an innovative approach for integrated warehouse operations.

  16. How to develop a Standard Operating Procedure for sorting unfixed cells

    Science.gov (United States)

    Schmid, Ingrid

    2012-01-01

    Written Standard Operating Procedures (SOPs) are an important tool to assure that recurring tasks in a laboratory are performed in a consistent manner. When the procedure covered in the SOP involves a high-risk activity such as sorting unfixed cells using a jet-in-air sorter, safety elements are critical components of the document. The details on sort sample handling, sorter set-up, validation, operation, troubleshooting, and maintenance, personal protective equipment (PPE), and operator training, outlined in the SOP are to be based on careful risk assessment of the procedure. This review provides background information on the hazards associated with sorting of unfixed cells and the process used to arrive at the appropriate combination of facility design, instrument placement, safety equipment, and practices to be followed. PMID:22381383

  17. How to develop a standard operating procedure for sorting unfixed cells.

    Science.gov (United States)

    Schmid, Ingrid

    2012-07-01

    Written standard operating procedures (SOPs) are an important tool to assure that recurring tasks in a laboratory are performed in a consistent manner. When the procedure covered in the SOP involves a high-risk activity such as sorting unfixed cells using a jet-in-air sorter, safety elements are critical components of the document. The details on sort sample handling, sorter set-up, validation, operation, troubleshooting, and maintenance, personal protective equipment (PPE), and operator training, outlined in the SOP are to be based on careful risk assessment of the procedure. This review provides background information on the hazards associated with sorting of unfixed cells and the process used to arrive at the appropriate combination of facility design, instrument placement, safety equipment, and practices to be followed. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. An empirical study on SAJQ (Sorting Algorithm for Join Queries

    Directory of Open Access Journals (Sweden)

    Hassan I. Mathkour

    2010-06-01

    Full Text Available Most queries that applied on database management systems (DBMS depend heavily on the performance of the used sorting algorithm. In addition to have an efficient sorting algorithm, as a primary feature, stability of such algorithms is a major feature that is needed in performing DBMS queries. In this paper, we study a new Sorting Algorithm for Join Queries (SAJQ that has both advantages of being efficient and stable. The proposed algorithm takes the advantage of using the m-way-merge algorithm in enhancing its time complexity. SAJQ performs the sorting operation in a time complexity of O(nlogm, where n is the length of the input array and m is number of sub-arrays used in sorting. An unsorted input array of length n is arranged into m sorted sub-arrays. The m-way-merge algorithm merges the sorted m sub-arrays into the final output sorted array. The proposed algorithm keeps the stability of the keys intact. An analytical proof has been conducted to prove that, in the worst case, the proposed algorithm has a complexity of O(nlogm. Also, a set of experiments has been performed to investigate the performance of the proposed algorithm. The experimental results have shown that the proposed algorithm outperforms other Stable–Sorting algorithms that are designed for join-based queries.

  19. A many-sorted calculus based on resolution and paramodulation

    CERN Document Server

    Walther, Christoph

    1987-01-01

    A Many-Sorted Calculus Based on Resolution and Paramodulation emphasizes the utilization of advantages and concepts of many-sorted logic for resolution and paramodulation based automated theorem proving.This book considers some first-order calculus that defines how theorems from given hypotheses by pure syntactic reasoning are obtained, shifting all the semantic and implicit argumentation to the syntactic and explicit level of formal first-order reasoning. This text discusses the efficiency of many-sorted reasoning, formal preliminaries for the RP- and ?RP-calculus, and many-sorted term rewrit

  20. Noticeable positive Doppler effect on optical bistability in an N-type active Raman gain atomic system

    International Nuclear Information System (INIS)

    Chang Zeng-Guang; Zhang Jing-Tao; Niu Yue-Ping; Gong Shang-Qing

    2012-01-01

    We theoretically investigate the Doppler effect on optical bistability in an N-type active Raman gain atomic system inside an optical ring cavity. It is shown that the Doppler effect can greatly enhance the dispersion and thus create the bistable behaviour or greatly increase the bistable region, which has been known as the positive Doppler effect on optical bistability. In addition, we find that a positive Doppler effect can change optical bistability from the hybrid dispersion-gain type to a dispersive type

  1. Effect of climate on morphology and development of sorted circles and polygons

    Czech Academy of Sciences Publication Activity Database

    Uxa, Tomáš; Mida, P.; Křížek, M.

    2017-01-01

    Roč. 28, č. 4 (2017), s. 663-674 ISSN 1045-6740 Institutional support: RVO:67985530 Keywords : patterned ground * sorted circles and polygons * morphology * active layer * Svalbard * high Arctic Subject RIV: DE - Earth Magnetism, Geodesy, Geography OBOR OECD: Physical geography Impact factor: 2.815, year: 2016

  2. A Low-Tech, Hands-On Approach To Teaching Sorting Algorithms to Working Students.

    Science.gov (United States)

    Dios, R.; Geller, J.

    1998-01-01

    Focuses on identifying the educational effects of "activity oriented" instructional techniques. Examines which instructional methods produce enhanced learning and comprehension. Discusses the problem of learning "sorting algorithms," a major topic in every Computer Science curriculum. Presents a low-tech, hands-on teaching method for sorting…

  3. Analysis of nearly simultaneous x-ray and optical observations of active galactic nuclei

    International Nuclear Information System (INIS)

    Webb, J.R.

    1988-01-01

    Rosemary Hill optical and EINSTEIN X-ray observations of a sample of 36 galactic nuclei (AGN) were reduced and analyzed. Seventy-two x-ray observations of these sources were reduced, nineteen of which yielded spectral information. Of these spectra observations, significant hydrogen column densities above the galactic value were required for nine of the active galactic nuclei. X-ray variability was detected in eight of the eleven sources which were observed more than once by EINSTEIN. Correlations between the x-ray and optical luminosities were investigated using the Jefferys method of least squares. This method allows for errors in both variables. The results indicate a strong correlation between the x-ray and optical luminosities for the entire sample. Division of the sample into groups with similar optical variability characteristics show that the less violently violent variable AGN are more highly correlated than the violently variable blazars. Infrared and radio observations were combined with the x-ray and optical observations of six AGN. These sources were modelled in terms of the synchrotron-self-Compton model. The turnover frequency falls between the infrared and radio data and reliable estimates of this parameter are difficult to estimate. Therefore the results were found as a function of the turnover frequency. Four sources required relativistic bulk motion or beaming. Multifrequency spectra made at different times for one individual source, 0235+164, required different amounts of beaming to satisfy the x-ray observations. Sizes of the emitting regions for the sources modelled ranged from 0.5 parsec to 1.0 parsec

  4. How to assess good candidate molecules for self-activated optical power limiting

    Science.gov (United States)

    Lundén, Hampus; Glimsdal, Eirik; Lindgren, Mikael; Lopes, Cesar

    2018-03-01

    Reverse saturable absorbers have shown great potential to attenuate laser radiation. Good candidate molecules and various particles have successfully been incorporated into different glass matrices, enabling the creation of self-activated filters against damaging laser radiation. Although the performance of such filters has been impressive, work is still ongoing to improve the performance in a wider range of wavelengths and pulse widths. The purpose of this tutorial is, from an optical engineering perspective, to give an understanding of the strengths and weaknesses of this class of smart materials, how relevant photophysical parameters are measured and influence system performance and comment on the pitfalls in experimental evaluation of materials. A numerical population model in combination with simple physical formulas is used to demonstrate system behavior from a performance standpoint. Geometrical reasoning shows the advantage of reverse saturable absorption over nonlinear scattering due to a fraction of scattered light being recollected by imaging system optics. The numerical population model illustrates the importance of the optical power limiting performance during the leading edge of a nanosecond pulse, which is most strongly influenced by changes in the two-photon absorption cross section and the triplet linear absorption cross section for a modeled Pt-acetylide. This tutorial not only targets optical engineers evaluating reverse saturable absorbing materials but also aims to assist researchers with a chemistry background working on optical power limiting materials. We also present photophysical data for a series of coumarins that can be useful for the determination of quantum yields and two-photon cross sections and show examples of characterization of molecules with excited triplet states.

  5. Polarized excitons and optical activity in single-wall carbon nanotubes

    Science.gov (United States)

    Chang, Yao-Wen; Jin, Bih-Yaw

    2018-05-01

    The polarized excitons and optical activity of single-wall carbon nanotubes (SWNTs) are studied theoretically by π -electron Hamiltonian and helical-rotational symmetry. By taking advantage of the symmetrization, the single-particle energy and properties of a SWNT are characterized with the corresponding helical band structure. The dipole-moment matrix elements, magnetic-moment matrix elements, and the selection rules can also be derived. Based on different selection rules, the optical transitions can be assigned as the parallel-polarized, left-handed circularly-polarized, and right-handed circularly-polarized transitions, where the combination of the last two gives the cross-polarized transition. The absorption and circular dichroism (CD) spectra are simulated by exciton calculation. The calculated results are well comparable with the reported measurements. Built on the foundation, magnetic-field effects on the polarized excitons and optical activity of SWNTs are studied. Dark-bright exciton splitting and interband Faraday effect in the CD spectrum of SWNTs under an axial magnetic field are predicted. The Faraday rotation dispersion can be analyzed according to the selection rules of circular polarizations and the helical band structure.

  6. Noise-robust unsupervised spike sorting based on discriminative subspace learning with outlier handling.

    Science.gov (United States)

    Keshtkaran, Mohammad Reza; Yang, Zhi

    2017-06-01

    Spike sorting is a fundamental preprocessing step for many neuroscience studies which rely on the analysis of spike trains. Most of the feature extraction and dimensionality reduction techniques that have been used for spike sorting give a projection subspace which is not necessarily the most discriminative one. Therefore, the clusters which appear inherently separable in some discriminative subspace may overlap if projected using conventional feature extraction approaches leading to a poor sorting accuracy especially when the noise level is high. In this paper, we propose a noise-robust and unsupervised spike sorting algorithm based on learning discriminative spike features for clustering. The proposed algorithm uses discriminative subspace learning to extract low dimensional and most discriminative features from the spike waveforms and perform clustering with automatic detection of the number of the clusters. The core part of the algorithm involves iterative subspace selection using linear discriminant analysis and clustering using Gaussian mixture model with outlier detection. A statistical test in the discriminative subspace is proposed to automatically detect the number of the clusters. Comparative results on publicly available simulated and real in vivo datasets demonstrate that our algorithm achieves substantially improved cluster distinction leading to higher sorting accuracy and more reliable detection of clusters which are highly overlapping and not detectable using conventional feature extraction techniques such as principal component analysis or wavelets. By providing more accurate information about the activity of more number of individual neurons with high robustness to neural noise and outliers, the proposed unsupervised spike sorting algorithm facilitates more detailed and accurate analysis of single- and multi-unit activities in neuroscience and brain machine interface studies.

  7. Noise-robust unsupervised spike sorting based on discriminative subspace learning with outlier handling

    Science.gov (United States)

    Keshtkaran, Mohammad Reza; Yang, Zhi

    2017-06-01

    Objective. Spike sorting is a fundamental preprocessing step for many neuroscience studies which rely on the analysis of spike trains. Most of the feature extraction and dimensionality reduction techniques that have been used for spike sorting give a projection subspace which is not necessarily the most discriminative one. Therefore, the clusters which appear inherently separable in some discriminative subspace may overlap if projected using conventional feature extraction approaches leading to a poor sorting accuracy especially when the noise level is high. In this paper, we propose a noise-robust and unsupervised spike sorting algorithm based on learning discriminative spike features for clustering. Approach. The proposed algorithm uses discriminative subspace learning to extract low dimensional and most discriminative features from the spike waveforms and perform clustering with automatic detection of the number of the clusters. The core part of the algorithm involves iterative subspace selection using linear discriminant analysis and clustering using Gaussian mixture model with outlier detection. A statistical test in the discriminative subspace is proposed to automatically detect the number of the clusters. Main results. Comparative results on publicly available simulated and real in vivo datasets demonstrate that our algorithm achieves substantially improved cluster distinction leading to higher sorting accuracy and more reliable detection of clusters which are highly overlapping and not detectable using conventional feature extraction techniques such as principal component analysis or wavelets. Significance. By providing more accurate information about the activity of more number of individual neurons with high robustness to neural noise and outliers, the proposed unsupervised spike sorting algorithm facilitates more detailed and accurate analysis of single- and multi-unit activities in neuroscience and brain machine interface studies.

  8. Active Ground Optical Remote Sensing for Improved Monitoring of Seedling Stress in Nurseries

    Directory of Open Access Journals (Sweden)

    Jan U. H. Eitel

    2010-03-01

    Full Text Available Active ground optical remote sensing (AGORS devices mounted on overhead irrigation booms could help to improve seedling quality by autonomously monitoring seedling stress. In contrast to traditionally used passive optical sensors, AGORS devices operate independently of ambient light conditions and do not require spectral reference readings. Besides measuring red (590–670 nm and near-infrared (>760 nm reflectance AGORS devices have recently become available that also measure red-edge (730 nm reflectance. We tested the hypothesis that the additional availability of red-edge reflectance information would improve AGORS of plant stress induced chlorophyll breakdown in Scots pine (Pinus sylvestris. Our results showed that the availability of red-edge reflectance information improved AGORS estimates of stress induced variation in chlorophyll concentration (r2 > 0.73, RMSE < 1.69 when compared to those without (r2 = 0.57, RMSE = 2.11.

  9. Purcell effect for active tuning of light scattering from semiconductor optical antennas.

    Science.gov (United States)

    Holsteen, Aaron L; Raza, Søren; Fan, Pengyu; Kik, Pieter G; Brongersma, Mark L

    2017-12-15

    Subwavelength, high-refractive index semiconductor nanostructures support optical resonances that endow them with valuable antenna functions. Control over the intrinsic properties, including their complex refractive index, size, and geometry, has been used to manipulate fundamental light absorption, scattering, and emission processes in nanostructured optoelectronic devices. In this study, we harness the electric and magnetic resonances of such antennas to achieve a very strong dependence of the optical properties on the external environment. Specifically, we illustrate how the resonant scattering wavelength of single silicon nanowires is tunable across the entire visible spectrum by simply moving the height of the nanowires above a metallic mirror. We apply this concept by using a nanoelectromechanical platform to demonstrate active tuning. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  10. Thermal Stability and Optical Activity of Erbium Doped Chalcogenide Glasses for Photonics

    Science.gov (United States)

    Tonchev, D.; Koughia, K.; Kasap, S. O.; Maeda, K.; Sakai, T.; Ikuta, J.; Ivanova, Z. G.

    The glass transition and crystallization temperatures (T g , T c ), heat capacity, thermal stability and glass uniformity of GeSGa, GeSeGa, Ge(SeTe)Ga chalcogenide glasses doped with Er3+ by the addition of Er2S3 have been investigated by conventional differential scanning calorimetry (DSC) and Temperature-Modulated DSC (TMDSC). While some of the glasses have two crystallization peaks, these glasses were nonetheless optically actively and uniform. Essential optical properties have been evaluated, such as the photoluminescence (PL) intensity and lifetime as a function of the glass composition. We present typical results to emphasize some of the important characteristics of these systems and discuss trends within a glass system; and also highlight differences between glass systems.

  11. Infrared-active optical phonons in LiFePO4 single crystals

    Science.gov (United States)

    Stanislavchuk, T. N.; Middlemiss, D. S.; Syzdek, J. S.; Janssen, Y.; Basistyy, R.; Sirenko, A. A.; Khalifah, P. G.; Grey, C. P.; Kostecki, R.

    2017-07-01

    Infrared-active optical phonons were studied in olivine LiFePO4 oriented single crystals by means of both rotating analyzer and rotating compensator spectroscopic ellipsometry in the spectral range between 50 and 1400 cm-1. The eigenfrequencies, oscillator strengths, and broadenings of the phonon modes were determined from fits of the anisotropic harmonic oscillator model to the data. Optical phonons in a heterosite FePO4 crystal were measured from the delithiated ab-surface of the LiFePO4 crystal and compared with the phonon modes of the latter. Good agreement was found between experimental data and the results of solid-state hybrid density functional theory calculations for the phonon modes in both LiFePO4 and FePO4.

  12. Separation and sorting of cells in microsystems using physical principles

    Science.gov (United States)

    Lee, Gi-Hun; Kim, Sung-Hwan; Ahn, Kihoon; Lee, Sang-Hoon; Park, Joong Yull

    2016-01-01

    In the last decade, microfabrication techniques have been combined with microfluidics and applied to cell biology. Utilizing such new techniques, various cell studies have been performed for the research of stem cells, immune cells, cancer, neurons, etc. Among the various biological applications of microtechnology-based platforms, cell separation technology has been highly regarded in biological and clinical fields for sorting different types of cells, finding circulating tumor cells (CTCs), and blood cell separation, amongst other things. Many cell separation methods have been created using various physical principles. Representatively, these include hydrodynamic, acoustic, dielectrophoretic, magnetic, optical, and filtering methods. In this review, each of these methods will be introduced, and their physical principles and sample applications described. Each physical principle has its own advantages and disadvantages. The engineers who design the systems and the biologists who use them should understand the pros and cons of each method or principle, to broaden the use of microsystems for cell separation. Continuous development of microsystems for cell separation will lead to new opportunities for diagnosing CTCs and cancer metastasis, as well as other elements in the bloodstream.

  13. Determining the Scattering Properties of Vertically-Structured Nepheloid Layers From the Fusion of Active and Passive Optical Sensors

    National Research Council Canada - National Science Library

    Bissett, W. P; Kohler, David D

    2006-01-01

    ... from the bottom back toward the surface. The net result is that these layers reduce the ability of active and passive optical instruments to retrieve estimates of bathymetry and bottom classification, as well as reduce the abilities...

  14. Fiber-optic transmission system information for the testing of active phased antenna arrays in an anechoic chamber.

    Science.gov (United States)

    Saveleiv, I. K.; Sharova, N. V.; Tarasenko, M. Yu; Yalunina, T. R.; Davydov, V. V.; Rud', V. Yu

    2017-11-01

    The results of the research of the developed fiber-optic transmission systems for analog high frequency signal are represented. On its basis, a new method to identify various structural defects in the active phased antenna arrays is elaborated.

  15. Macro optical projection tomography for large scale 3D imaging of plant structures and gene activity.

    Science.gov (United States)

    Lee, Karen J I; Calder, Grant M; Hindle, Christopher R; Newman, Jacob L; Robinson, Simon N; Avondo, Jerome J H Y; Coen, Enrico S

    2017-01-01

    Optical projection tomography (OPT) is a well-established method for visualising gene activity in plants and animals. However, a limitation of conventional OPT is that the specimen upper size limit precludes its application to larger structures. To address this problem we constructed a macro version called Macro OPT (M-OPT). We apply M-OPT to 3D live imaging of gene activity in growing whole plants and to visualise structural morphology in large optically cleared plant and insect specimens up to 60 mm tall and 45 mm deep. We also show how M-OPT can be used to image gene expression domains in 3D within fixed tissue and to visualise gene activity in 3D in clones of growing young whole Arabidopsis plants. A further application of M-OPT is to visualise plant-insect interactions. Thus M-OPT provides an effective 3D imaging platform that allows the study of gene activity, internal plant structures and plant-insect interactions at a macroscopic scale. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  16. The role of color sorting machine in reducing food safety risks

    Directory of Open Access Journals (Sweden)

    Eleonora Kecskes-Nagy

    2016-07-01

    Full Text Available It is the very difficult problem how we can decrease food safety risks in the product, which was polluted in process of cropping. According to professional literature almost the prevention is considered as an exclusive method to keep below safe level the content of DON toxin. The source of food safety in food chain is that the primary products suit the food safety requirements. It is a very difficult or sometimes it is not possible to correct food safety risk factors - which got into the products during cultivation - in the course of processing. Such factor is fusariotoxin in fodder and bread wheat. DON toxin is the most frequent toxin in cereals. The objective of the searching was to investigate, if it is possible to decrease DON toxin content of durum wheat and to minimize the food safety risk by application milling technology with good production practice and technological conditions. The samples were taken in the first phase of milling technology just before and after color sorting. According to measuring results Sortex Z+ optical sorting decreased DON toxin content of wheat. This mean that the food safety risks can be reduced by Sortex Z+ optical sorting machine. Our experiments proved if there is color sorting in the cleaning process preceding the milling of wheat then a part of the grain of wheat infected by Fusarium sp. can be selected. This improves the food safety parameters of given lot of wheat and decrease the toxin content. The flour made from contaminated grains of wheat can be a serious food safety risk. We would like to support scientifically the technical development of milling technology with our experimental data. Normal 0 21 false false false HU X-NONE X-NONE MicrosoftInternetExplorer4

  17. Sorting on the basis of deformability of single cells in a femtosecond laser fabricated optofluidic device

    Science.gov (United States)

    Bragheri, F.; Paiè, P.; Yang, T.; Nava, G.; Martınez Vázquez, R.; Di Tano, M.; Veglione, M.; Minzioni, P.; Mondello, C.; Cristiani, I.; Osellame, R.

    2015-03-01

    Optical stretching is a powerful technique for the mechanical phenotyping of single suspended cells that exploits cell deformability as an inherent functional marker. Dual-beam optical trapping and stretching of cells is a recognized tool to investigate their viscoelastic properties. The optical stretcher has the ability to deform cells through optical forces without physical contact or bead attachment. In addition, it is the only method that can be combined with microfluidic delivery, allowing for the serial, high-throughput measurement of the optical deformability and the selective sorting of single specific cells. Femtosecond laser micromachining can fabricate in the same chip both the microfluidic channel and the optical waveguides, producing a monolithic device with a very precise alignment between the components and very low sensitivity to external perturbations. Femtosecond laser irradiation in a fused silica chip followed by chemical etching in hydrofluoric acid has been used to fabricate the microfluidic channels where the cells move by pressure-driven flow. With the same femtosecond laser source two optical waveguides, orthogonal to the microfluidic channel and opposing each other, have been written inside the chip. Here we present an optimized writing process that provides improved wall roughness of the micro-channels allowing high-quality imaging. In addition, we will show results on cell sorting on the basis of mechanical properties in the same device: the different deformability exhibited by metastatic and tumorigenic cells has been exploited to obtain a metastasis-cells enriched sample. The enrichment is verified by exploiting, after cells collection, fluorescence microscopy.

  18. Looking for a Symphony: A Sort of Essay with a Perspective on Activity Theories and the Ontology of Psychology: Learning from Danish and Russian Experiences by Jens Mammen & Irina Mironenko.

    Science.gov (United States)

    Neumann, Asger

    2016-06-01

    As a perspective on Mammen and Miroenkos the article is reflecting on the possibility of Activity Theory being a foundation on which Psychology could be integrated. Mammen and Miroenkos point that directed activity not only is towards objects "defined as a sum of qualities, but by individual reference" is a starting point. As a specific example the phenomenon Love, as "significant object relations", is related to the concept "choice categories". It is stated that relations of affection and love can't be understood independent of history of common activity, and that this makes the concept "choice categories" central in a psychological understanding of what love is.

  19. Sediment sorting at a side channel bifurcation

    Science.gov (United States)

    van Denderen, Pepijn; Schielen, Ralph; Hulscher, Suzanne

    2017-04-01

    Side channels have been constructed to reduce the flood risk and to increase the ecological value of the river. In various Dutch side channels large aggradation in these channels occurred after construction. Measurements show that the grain size of the deposited sediment in the side channel is smaller than the grain size found on the bed of the main channel. This suggest that sorting occurs at the bifurcation of the side channel. The objective is to reproduce with a 2D morphological model the fining of the bed in the side channel and to study the effect of the sediment sorting on morphodynamic development of the side channel. We use a 2D Delft3D model with two sediment fractions. The first fraction corresponds with the grain size that can be found on the bed of the main channel and the second fraction corresponds with the grain size found in the side channel. With the numerical model we compute several side channel configurations in which we vary the length and the width of the side channel, and the curvature of the upstream channel. From these computations we can derive the equilibrium state and the time scale of the morphodynamic development of the side channel. Preliminary results show that even when a simple sediment transport relation is used, like Engelund & Hansen, more fine sediment enters the side channel than coarse sediment. This is as expected, and is probably related to the bed slope effects which are a function of the Shields parameter. It is expected that by adding a sill at the entrance of the side channel the slope effect increases. This might reduce the amount of coarse sediment which enters the side channel even more. It is unclear whether the model used is able to reproduce the effect of such a sill correctly as modelling a sill and reproducing the correct hydrodynamic and morphodynamic behaviour is not straightforward in a 2D model. Acknowledgements: This research is funded by STW, part of the Dutch Organization for Scientific Research under

  20. A Preliminary Study of MSD-First Radix-Sorting Methed

    OpenAIRE

    小田, 哲久

    1984-01-01

    Many kinds of sorting algorithms have been developed from the age of Punched Card System. Nowadays, any sorting algorithm can be called either (1) internal sorting methed or (2) external sorting method. Internal sorting method is used only when the number of records to be sorted (N) is not so large for the internal memory of the computer system. Larger memory space has become available with the aid of semiconductor technology. Therefore, it might be desired to develop a new internal sorting m...

  1. Magnetic Sorting of the Regolith on the Moon: Lunar Swirls

    Science.gov (United States)

    Pieters, C. M.; Garrick-Bethell, I.; Hemingway, D.

    2014-12-01

    All of the mysterious albedo features on the Moon called "lunar swirls" are associated with magnetic anomalies, but not all magnetic anomalies are associated with lunar swirls [1]. It is often hypothesized that the albedo markings are tied to immature regolith on the surface, perhaps due to magnetic shielding of the solar wind and prevention of normal space weathering of the soil. Although interaction of the solar wind with the surface at swirls is indeed affected by the local magnetic field [2], this does not appear to result in immature soils on the surface. Calibrated spectra from the Moon Mineralogy Mapper [M3] (in image format) demonstrate that the high albedo markings for swirls are simply not consistent with immature regolith as is now understood from detailed analyses of lunar samples [eg 3]. However, M3 data show that the high albedo features of swirls are distinct and quite different from normal soils (in both the highlands and the mare). They allexhibit a flatter continuum across the near-infrared, but the actual band strength of ferrous minerals shows little (if any) deviation [4]. Recent analyses of magnetic field direction at swirls [5] mimic the observed albedo patterns (horizontal surface fields in bright areas, vertical surface fields in dark lanes). When coupled with the optical properties of magnetic separates of lunar soils [6] and our knowledge that the magnetic component of the soil results from space weathering [3,6], we propose a new and very simple explanation for these enigmatic albedo markings: the lunar swirls result from magnetic sorting of a well developed regolith. With time, normal gardening of the soil over a magnetic anomaly causes some of the dark magnetic component of the soil to be gradually removed from regions (high albedo areas) and accumulated in others (dark lanes). We are modeling predicted sorting rates using realistic rates of dust production. If this mechanism is tenable, only the origin of these magnetic anomalies

  2. Transcriptional profiling of cells sorted by RNA abundance

    NARCIS (Netherlands)

    Klemm, Sandy; Semrau, Stefan; Wiebrands, Kay; Mooijman, Dylan; Faddah, Dina A; Jaenisch, Rudolf; van Oudenaarden, Alexander

    We have developed a quantitative technique for sorting cells on the basis of endogenous RNA abundance, with a molecular resolution of 10-20 transcripts. We demonstrate efficient and unbiased RNA extraction from transcriptionally sorted cells and report a high-fidelity transcriptome measurement of

  3. An introduction to three algorithms for sorting in situ

    NARCIS (Netherlands)

    Dijkstra, E.W.; Gasteren, van A.J.M.

    1982-01-01

    The purpose of this paper is to give a crisp introduction to three algorithms for sorting in situ, viz. insertion sort, heapsort and smoothsort. The more complicated the algorithm, the more elaborate the justification for the design decisions embodied by it. In passing we offer a style for the

  4. The PreferenSort: A Holistic Instrument for Career Counseling

    Science.gov (United States)

    Amit, Adi; Sagiv, Lilach

    2013-01-01

    We present the PreferenSort, a career counseling instrument that derives counselees' vocational interests from their preferences among occupational titles. The PreferenSort allows for a holistic decision process, while taking into account the full complexity of occupations and encouraging deliberation about one's preferences and acceptable…

  5. New age radiometric ore sorting - the elegant solution

    International Nuclear Information System (INIS)

    Gordon, H.P.; Heuer, T.

    2000-01-01

    Radiometric ore sorting technology and application are described in two parts. Part I reviews the history of radiometric sorting in the minerals industry and describes the latest developments in radiometric sorting technology. Part II describes the history, feasibility study and approach used in the application of the new technology at Rossing Uranium Limited. There has been little progress in the field of radiometric sorting since the late 1970s. This has changed with the development of a high capacity radiometric sorter designed to operate on low-grade ore in the +75mm / -300mm size fraction. This has been designed specifically for an application at Rossing. Rossing has a long history in radiometric sorting dating back to 1968 when initial tests were conducted on the Rossing prospect. Past feasibility studies concluded that radiometric sorting would not conclusively reduce the unit cost of production unless sorting was used to increase production levels. The current feasibility study shows that the application of new radiometric sorter technology makes sorting viable without increasing production, and significantly more attractive with increased production. A pilot approach to confirm sorter performance is described. (author)

  6. Magnetic fluid equipment for sorting of secondary polyolefins from waste

    NARCIS (Netherlands)

    Rem, P.C.; Di Maio, F.; Hu, B.; Houzeaux, G.; Baltes, L.; Tierean, M.

    2012-01-01

    The paper presents the researches made on the FP7 project „Magnetic Sorting and Ultrasound Sensor Technologies for Production of High Purity Secondary Polyolefins from Waste” in order to develop a magnetic fluid equipment for sorting of polypropylene (PP) and polyethylene (PE) from polymers mixed

  7. Decision trees with minimum average depth for sorting eight elements

    KAUST Repository

    AbouEisha, Hassan M.; Chikalov, Igor; Moshkov, Mikhail

    2015-01-01

    We prove that the minimum average depth of a decision tree for sorting 8 pairwise different elements is equal to 620160/8!. We show also that each decision tree for sorting 8 elements, which has minimum average depth (the number of such trees

  8. Multiple pathways for vacuolar sorting of yeast proteinase A

    DEFF Research Database (Denmark)

    Westphal, V; Marcusson, E G; Winther, Jakob R.

    1996-01-01

    The sorting of the yeast proteases proteinase A and carboxypeptidase Y to the vacuole is a saturable, receptor-mediated process. Information sufficient for vacuolar sorting of the normally secreted protein invertase has in fusion constructs previously been found to reside in the propeptide...

  9. Cell sorting using efficient light shaping approaches

    DEFF Research Database (Denmark)

    Banas, Andrew; Palima, Darwin; Villangca, Mark Jayson

    2016-01-01

    distributions aimed at the positions of the detected cells. Furthermore, the beam shaping freedom provided by GPC can allow optimizations in the beam’s propagation and its interaction with the catapulted cells. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading...... is gentler, less invasive and more economical compared to conventional FACS systems. As cells are less responsive to plastic or glass beads commonly used in the optical manipulation literature, and since laser safety would be an issue in clinical use, we develop efficient approaches in utilizing lasers...... and light modulation devices. The Generalized Phase Contrast (GPC) method that can be used for efficiently illuminating spatial light modulators or creating well-defined contiguous optical traps is supplemented by diffractive techniques capable of integrating the available light and creating 2D or 3D beam...

  10. Disease Activity and Conversion into Multiple Sclerosis after Optic Neuritis Is Treated with Erythropoietin

    Directory of Open Access Journals (Sweden)

    Kurt-Wolfram Sühs

    2016-09-01

    Full Text Available Changes in cerebral lesion load by magnetic resonance imaging (MRI in patients from a double-blind, placebo-controlled, phase II study on erythropoietin in clinically isolated optic neuritis (ClinicalTrials.gov, NCT00355095 were analyzed. Therefore, patients with acute optic neuritis were assigned to receive either 33,000 IU of recombinant human erythropoietin (IV daily for three days, or a placebo, as an add-on to methylprednisolone. Of 35 patients, we investigated changes in cerebral lesion load in MRIs obtained at baseline and at weeks 4, 8, and 16. In 5 of the 35 patients, we found conversion into multiple sclerosis (MS based on MRI progression only. These five patients had received the placebo. Another five patients showed MRI progression together with relapses. Three of these patients had received erythropoietin, and two the placebo. Yet, analyzing the change in absolute numbers of periventricular, juxtacortical, and infratentorial lesions including gadolinium-enhancing lesions, there were no significant differences between the groups. Although effective in terms of retinal nerve fiber layer protection, erythropoietin treatment of acute isolated optic neuritis did not influence further evolution of MRI lesions in the brain when comparing absolute numbers. However, early conversion from clinically isolated syndrome to MS assessed by MRI activity seemed to occur more frequently in the placebo-treated group.

  11. DUST IN ACTIVE GALACTIC NUCLEI: ANOMALOUS SILICATE TO OPTICAL EXTINCTION RATIOS?

    Energy Technology Data Exchange (ETDEWEB)

    Lyu, Jianwei; Hao, Lei [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China); Li, Aigen, E-mail: haol@shao.ac.cn [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States)

    2014-09-01

    Dust plays a central role in the unification theory of active galactic nuclei (AGNs). However, little is known about the nature (e.g., size, composition) of the dust that forms a torus around the AGN. In this Letter, we report a systematic exploration of the optical extinction (A{sub V} ) and the silicate absorption optical depth (Δτ{sub 9.7}) of 110 type 2 AGNs. We derive A{sub V} from the Balmer decrement based on the Sloan Digital Sky Survey data, and Δτ{sub 9.7} from the Spitzer/InfraRed Spectrograph data. We find that with a mean ratio of (A{sub V} /Δτ{sub 9.7}) ≲ 5.5, the optical-to-silicate extinction ratios of these AGNs are substantially lower than that of the Galactic diffuse interstellar medium (ISM) for which A{sub V} /Δτ{sub 9.7} ≈ 18.5. We argue that the anomalously low A{sub V} /Δτ{sub 9.7} ratio could be due to the predominance of larger grains in the AGN torus compared to that in the Galactic diffuse ISM.

  12. Structural control of side-chain chromophores to achieve highly efficient electro-optic activity.

    Science.gov (United States)

    Yang, Yuhui; Chen, Zhuo; Liu, Jialei; Xiao, Hongyan; Zhen, Zhen; Liu, Xinhou; Jiang, Guohua

    2017-05-10

    A series of chromophores J1-J4 have been synthesized based on julolidine donors modified with different rigid steric hindrance groups. Compared with the chromophore (J1) without the isolation group, chromophores J2, J3 and J4 show better stability. Structural analysis and photophysical property measurements were carried out to compare the molecular mobility and steric hindrance effect of the different donor-modified chromophores. All of these chromophores with isolation groups showed superb thermal stabilities with high thermal decomposition temperatures above 250 °C. Furthermore, with rigid steric hindrance, chromophores J3 and J4 showed more enhanced thermal stabilities with thermal decomposition temperatures of 269 °C and 275 °C, respectively. Density functional theory was used to calculate the hyperpolarizability (β), and the high molecular hyperpolarizability of these chromophores can be effectively translated into large electro-optic coefficients. The electro-optic coefficients of poled films containing 20 wt% of these new chromophores doped in amorphous polycarbonate were 127, 266 and 209 pm V -1 at 1310 nm for chromophores J1-J3, respectively, while the film containing chromophore J4 showed the largest r 33 value of only 97 pm V -1 at 25 wt%. These results indicated that the introduced isolation group can reduce intermolecular electrostatic interactions, thus enhancing the macroscopic electro-optic activity, while the size of the isolation group should be suitable.

  13. Application of Optical Biosensors in Small-Molecule Screening Activities

    Directory of Open Access Journals (Sweden)

    Wolfgang Knecht

    2012-03-01

    Full Text Available The last two decades have seen remarkable progress and improvements in optical biosensor systems such that those are currently seen as an important and value-adding component of modern drug screening activities. In particular the introduction of microplate-based biosensor systems holds the promise to match the required throughput without compromising on data quality thus representing a sought-after complement to traditional fluidic systems. This article aims to highlight the application of the two most prominent optical biosensor technologies, namely surface plasmon resonance (SPR and optical waveguide grating (OWG, in small-molecule screening and will present, review and discuss the advantages and disadvantages of different assay formats on these platforms. A particular focus will be on the specific advantages of the inhibition in solution assay (ISA format in contrast to traditional direct binding assays (DBA. Furthermore we will discuss different application areas for both fluidic as well as plate-based biosensor systems by considering the individual strength of the platforms.

  14. Thermally activated phase slips of one-dimensional Bose gases in shallow optical lattices

    Science.gov (United States)

    Kunimi, Masaya; Danshita, Ippei

    2017-03-01

    We study the decay of superflow via thermally activated phase slips in one-dimensional Bose gases in a shallow optical lattice. By using the Kramers formula, we numerically calculate the nucleation rate of a thermally activated phase slip for various values of the filling factor and flow velocity in the absence of a harmonic trapping potential. Within the local density approximation, we derive a formula connecting the phase-slip nucleation rate with the damping rate of a dipole oscillation of the Bose gas in the presence of a harmonic trap. We use the derived formula to directly compare our theory with the recent experiment done by the LENS group [L. Tanzi et al., Sci. Rep. 6, 25965 (2016), 10.1038/srep25965]. From the comparison, the observed damping of dipole oscillations in a weakly correlated and small velocity regime is attributed dominantly to thermally activated phase slips rather than quantum phase slips.

  15. Laser-based optical activity detection of amino acids and proteins

    Energy Technology Data Exchange (ETDEWEB)

    Reitsma, B.H.

    1987-08-01

    The optical activity detector (OAD) for HPLC is a selective detector for optically active substances including amino acids and proteins. Four free amino acids were resolved using cation-exchange chromatography followed by detection with refractive index detector (RI) for proline and threonine and the OAD to an ultraviolet absorbance detector (uv) for tyrosine and phenylalanine. Amino acid detection by refractive index is not sensitive and uv absorbance detects only three amino acids. Derivatization of amino acids to make them detectable by uv absorbance enhances the applicability of OA/uv for the determination of enantiomeric ratios. The separation of 16 dansyl-L-amino acids by RP-HPLC with detection by OA/uv is illustrated. Calculation of the specific rotation of 22 dansyl-L-amino acids shows that derivatization enhances the OA detectability of some amino acids but degrades that of others. RP-HPLC of proteins is a rapidly developing technique. Several researchers have reported the detection of multiple peaks when a pure protein is subjected to HPLC under certain conditions. These multiple peaks have been determined to be different conformations of the same protein. Since proteins are optically active, OA is a suitable detector. The RP-HPLC separation of conformers of soybean trypsin inhibitor is illustrated. Detection by OA/uv provides insights from the chromatogram unavailable from uv absorbance detection alone. In addition, identification of impurities is simplified with OA/uv. Specific rotations of the separated protein fractions show no significant change accompanying change in conformation. 163 refs., 13 figs., 9 tabs.

  16. Science and technology of kernels and TRISO coated particle sorting

    International Nuclear Information System (INIS)

    Nothnagel, G.

    2006-09-01

    The ~1mm diameter TRISO coated particles, which form the elemental units of PBMR nuclear fuel, has to be close to spherical in order to best survive damage during sphere pressing. Spherical silicon carbide layers further provide the strongest miniature pressure vessels for fission product retention. To make sure that the final product contains particles of acceptable shape, 100% of kernels and coated particles have to be sorted on a surface-ground sorting table. Broken particles, twins, irregular (odd) shapes and extreme ellipsoids have to be separated from the final kernel and coated particle batches. Proper sorting of particles is an extremely important step in quality fuel production as the final failure fraction depends sensitively on the quality of sorting. After sorting a statistically significant sample of the sorted product is analysed for sphericity, which is defined as the ratio of maximum to minimum diameter, as part of a standard QC test to ensure conformance to German specifications. In addition a burn-leach test is done on coated particles (before pressing) and fuel spheres (after pressing) to ensure adherence to failure specifications. Because of the extreme importance of particle sorting for assurance of fuel quality it is essential to have an in-depth understanding of the capabilities and limitations of particle sorting. In this report a systematic scientific rationale is developed, from fundamental principles, to provide a basis for understanding the relationship between product quality and sorting parameters. The principles and concepts, developed in this report, will be of importance when future sorting tables (or equivalents) are to be designed. A number of new concepts and methodologies are developed to assist with equivalence validation of any two sorting tables. This is aimed in particular towards quantitative assessment of equivalence between current QC tables (closely based on the original NUKEM parameters, except for the driving mechanism

  17. The photochemical reflectance index provides an optical indicator of spring photosynthetic activation in evergreen conifers.

    Science.gov (United States)

    Wong, Christopher Y S; Gamon, John A

    2015-04-01

    In evergreens, the seasonal down-regulation and reactivation of photosynthesis is largely invisible and difficult to assess with remote sensing. This invisible phenology may be changing as a result of climate change. To better understand the mechanism and timing of these hidden physiological transitions, we explored several assays and optical indicators of spring photosynthetic activation in conifers exposed to a boreal climate. The photochemical reflectance index (PRI), chlorophyll fluorescence, and leaf pigments for evergreen conifer seedlings were monitored over 1 yr of a boreal climate with the addition of gas exchange during the spring. PRI, electron transport rate, pigment levels, light-use efficiency and photosynthesis all exhibited striking seasonal changes, with varying kinetics and strengths of correlation, which were used to evaluate the mechanisms and timing of spring activation. PRI and pigment pools were closely timed with photosynthetic reactivation measured by gas exchange. The PRI provided a clear optical indicator of spring photosynthetic activation that was detectable at leaf and stand scales in conifers. We propose that PRI might provide a useful metric of effective growing season length amenable to remote sensing and could improve remote-sensing-driven models of carbon uptake in evergreen ecosystems. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  18. Motionless active depth from defocus system using smart optics for camera autofocus applications

    Science.gov (United States)

    Amin, M. Junaid; Riza, Nabeel A.

    2016-04-01

    This paper describes a motionless active Depth from Defocus (DFD) system design suited for long working range camera autofocus applications. The design consists of an active illumination module that projects a scene illuminating coherent conditioned optical radiation pattern which maintains its sharpness over multiple axial distances allowing an increased DFD working distance range. The imager module of the system responsible for the actual DFD operation deploys an electronically controlled variable focus lens (ECVFL) as a smart optic to enable a motionless imager design capable of effective DFD operation. An experimental demonstration is conducted in the laboratory which compares the effectiveness of the coherent conditioned radiation module versus a conventional incoherent active light source, and demonstrates the applicability of the presented motionless DFD imager design. The fast response and no-moving-parts features of the DFD imager design are especially suited for camera scenarios where mechanical motion of lenses to achieve autofocus action is challenging, for example, in the tiny camera housings in smartphones and tablets. Applications for the proposed system include autofocus in modern day digital cameras.

  19. Wide-field optical mapping of neural activity and brain haemodynamics: considerations and novel approaches

    Science.gov (United States)

    Ma, Ying; Shaik, Mohammed A.; Kozberg, Mariel G.; Thibodeaux, David N.; Zhao, Hanzhi T.; Yu, Hang

    2016-01-01

    Although modern techniques such as two-photon microscopy can now provide cellular-level three-dimensional imaging of the intact living brain, the speed and fields of view of these techniques remain limited. Conversely, two-dimensional wide-field optical mapping (WFOM), a simpler technique that uses a camera to observe large areas of the exposed cortex under visible light, can detect changes in both neural activity and haemodynamics at very high speeds. Although WFOM may not provide single-neuron or capillary-level resolution, it is an attractive and accessible approach to imaging large areas of the brain in awake, behaving mammals at speeds fast enough to observe widespread neural firing events, as well as their dynamic coupling to haemodynamics. Although such wide-field optical imaging techniques have a long history, the advent of genetically encoded fluorophores that can report neural activity with high sensitivity, as well as modern technologies such as light emitting diodes and sensitive and high-speed digital cameras have driven renewed interest in WFOM. To facilitate the wider adoption and standardization of WFOM approaches for neuroscience and neurovascular coupling research, we provide here an overview of the basic principles of WFOM, considerations for implementation of wide-field fluorescence imaging of neural activity, spectroscopic analysis and interpretation of results. This article is part of the themed issue ‘Interpreting BOLD: a dialogue between cognitive and cellular neuroscience’. PMID:27574312

  20. Wide-field optical mapping of neural activity and brain haemodynamics: considerations and novel approaches.

    Science.gov (United States)

    Ma, Ying; Shaik, Mohammed A; Kim, Sharon H; Kozberg, Mariel G; Thibodeaux, David N; Zhao, Hanzhi T; Yu, Hang; Hillman, Elizabeth M C

    2016-10-05

    Although modern techniques such as two-photon microscopy can now provide cellular-level three-dimensional imaging of the intact living brain, the speed and fields of view of these techniques remain limited. Conversely, two-dimensional wide-field optical mapping (WFOM), a simpler technique that uses a camera to observe large areas of the exposed cortex under visible light, can detect changes in both neural activity and haemodynamics at very high speeds. Although WFOM may not provide single-neuron or capillary-level resolution, it is an attractive and accessible approach to imaging large areas of the brain in awake, behaving mammals at speeds fast enough to observe widespread neural firing events, as well as their dynamic coupling to haemodynamics. Although such wide-field optical imaging techniques have a long history, the advent of genetically encoded fluorophores that can report neural activity with high sensitivity, as well as modern technologies such as light emitting diodes and sensitive and high-speed digital cameras have driven renewed interest in WFOM. To facilitate the wider adoption and standardization of WFOM approaches for neuroscience and neurovascular coupling research, we provide here an overview of the basic principles of WFOM, considerations for implementation of wide-field fluorescence imaging of neural activity, spectroscopic analysis and interpretation of results.This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'. © 2016 The Authors.

  1. A Fully Automated Approach to Spike Sorting.

    Science.gov (United States)

    Chung, Jason E; Magland, Jeremy F; Barnett, Alex H; Tolosa, Vanessa M; Tooker, Angela C; Lee, Kye Y; Shah, Kedar G; Felix, Sarah H; Frank, Loren M; Greengard, Leslie F

    2017-09-13

    Understanding the detailed dynamics of neuronal networks will require the simultaneous measurement of spike trains from hundreds of neurons (or more). Currently, approaches to extracting spike times and labels from raw data are time consuming, lack standardization, and involve manual intervention, making it difficult to maintain data provenance and assess the quality of scientific results. Here, we describe an automated clustering approach and associated software package that addresses these problems and provides novel cluster quality metrics. We show that our approach has accuracy comparable to or exceeding that achieved using manual or semi-manual techniques with desktop central processing unit (CPU) runtimes faster than acquisition time for up to hundreds of electrodes. Moreover, a single choice of parameters in the algorithm is effective for a variety of electrode geometries and across multiple brain regions. This algorithm has the potential to enable reproducible and automated spike sorting of larger scale recordings than is currently possible. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Particle sorting by Paramecium cilia arrays.

    Science.gov (United States)

    Mayne, Richard; Whiting, James G H; Wheway, Gabrielle; Melhuish, Chris; Adamatzky, Andrew

    Motile cilia are cell-surface organelles whose purposes, in ciliated protists and certain ciliated metazoan epithelia, include generating fluid flow, sensing and substance uptake. Certain properties of cilia arrays, such as beating synchronisation and manipulation of external proximate particulate matter, are considered emergent, but remain incompletely characterised despite these phenomena having being the subject of extensive modelling. This study constitutes a laboratory experimental characterisation of one of the emergent properties of motile cilia: manipulation of adjacent particulates. The work demonstrates through automated videomicrographic particle tracking that interactions between microparticles and somatic cilia arrays of the ciliated model organism Paramecium caudatum constitute a form of rudimentary 'sorting'. Small particles are drawn into the organism's proximity by cilia-induced fluid currents at all times, whereas larger particles may be held immobile at a distance from the cell margin when the cell generates characteristic feeding currents in the surrounding media. These findings can contribute to the design and fabrication of biomimetic cilia, with potential applications to the study of ciliopathies. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. A Parallel Modular Biomimetic Cilia Sorting Platform

    Directory of Open Access Journals (Sweden)

    James G. H. Whiting

    2018-03-01

    Full Text Available The aquatic unicellular organism Paramecium caudatum uses cilia to swim around its environment and to graze on food particles and bacteria. Paramecia use waves of ciliary beating for locomotion, intake of food particles and sensing. There is some evidence that Paramecia pre-sort food particles by discarding larger particles, but intake the particles matching their mouth cavity. Most prior attempts to mimic cilia-based manipulation merely mimicked the overall action rather than the beating of cilia. The majority of massive-parallel actuators are controlled by a central computer; however, a distributed control would be far more true-to-life. We propose and test a distributed parallel cilia platform where each actuating unit is autonomous, yet exchanging information with its closest neighboring units. The units are arranged in a hexagonal array. Each unit is a tileable circuit board, with a microprocessor, color-based object sensor and servo-actuated biomimetic cilia actuator. Localized synchronous communication between cilia allowed for the emergence of coordinated action, moving different colored objects together. The coordinated beating action was capable of moving objects up to 4 cm/s at its highest beating frequency; however, objects were moved at a speed proportional to the beat frequency. Using the local communication, we were able to detect the shape of objects and rotating an object using edge detection was performed; however, lateral manipulation using shape information was unsuccessful.

  4. Microfluidic-chip platform for cell sorting

    Science.gov (United States)

    Malik, Sarul; Balyan, Prerna; Akhtar, J.; Agarwal, Ajay

    2016-04-01

    Cell sorting and separation are considered to be very crucial preparatory steps for numerous clinical diagnostics and therapeutics applications in cell biology research arena. Label free cell separation techniques acceptance rate has been increased to multifold by various research groups. Size based cell separation method focuses on the intrinsic properties of the cell which not only avoids clogging issues associated with mechanical and centrifugation filtration methods but also reduces the overall cost for the process. Consequentially flow based cell separation method for continuous flow has attracted the attention of millions. Due to the realization of structures close to particle size in micro dimensions, the microfluidic devices offer precise and rapid particle manipulation which ultimately leads to an extraordinary cell separation results. The proposed microfluidic device is fabricated to separate polystyrene beads of size 1 µm, 5 µm, 10 µm and 20 µm. The actual dimensions of blood corpuscles were kept in mind while deciding the particle size of polystyrene beads which are used as a model particles for study.

  5. Nanoplasmonic lenses for bacteria sorting (Presentation Recording)

    Science.gov (United States)

    Zhu, Xiangchao; Yanik, Ahmet A.

    2015-08-01

    We demonstrate that patches of two dimensional arrays of circular plasmonic nanoholes patterned on gold-titanium thin film enables subwavelength focusing of visible light in far field region. Efficient coupling of the light with the excited surface plasmon at metal dielectric interface results in strong light transmission. As a result, surface plasmon plays an important role in the far field focusing behavior of the nanohole-aperture patches device. Furthermore, the focal length of the focused beam was found to be predominantly dependent on the overall size of the patch, which is in good agreement with that calculated by Rayleigh-Sommerfield integral formula. The focused light beam can be utilized to separate bio-particles in the dynamic range from 0.1 μm to 1 μm through mainly overcoming the drag force induced by fluid flow. In our proposed model, focused light generated by our plasmonic lenses will push the larger bio-particles in size back to the source of fluid flow and allow the smaller particles to move towards the central aperture of the patch. Such a new kind of plasmonic lenses open up possibility of sorting bacterium-like particles with plasmonic nanolenses, and also represent a promising tool in the field of virology.

  6. Help the planet by sorting your waste!

    CERN Multimedia

    2012-01-01

    Paper and cardboard waste comes in various forms, from newspapers to the toughest cardboard. Every year CERN dispatches about 200 tonnes of paper and cardboard to a recycling plant, but this is still too little when you take into consideration the tonnes of paper and cardboard that are still thrown out as part of ordinary rubbish or are incorrectly sorted into other rubbish skips.   Each office is equipped with a wastepaper bin, and a paper and cardboard container is available near every building. Cardboard boxes should be folded before they are placed in the containers in order to save space. Please note: Here are some sobering statistics: - 2 to 3 tonnes of wood pulp are required to manufacture 1 tonne of paper. - Each tonne of recycled paper means that we can save approximately 15 trees and substantial amounts of the water that is needed to extract cellulose (60 litres of water per kilo of paper). - A production of 100% recycled paper represents a 90% saving in water. - 5000 kWh of e...

  7. Tradeoffs Between Branch Mispredictions and Comparisons for Sorting Algorithms

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Moruz, Gabriel

    2005-01-01

    Branch mispredictions is an important factor affecting the running time in practice. In this paper we consider tradeoffs between the number of branch mispredictions and the number of comparisons for sorting algorithms in the comparison model. We prove that a sorting algorithm using O(dnlog n......) comparisons performs Omega(nlogd n) branch mispredictions. We show that Multiway MergeSort achieves this tradeoff by adopting a multiway merger with a low number of branch mispredictions. For adaptive sorting algorithms we similarly obtain that an algorithm performing O(dn(1+log (1+Inv/n))) comparisons must...... perform Omega(nlogd (1+Inv/n)) branch mispredictions, where Inv is the number of inversions in the input. This tradeoff can be achieved by GenericSort by Estivill-Castro and Wood by adopting a multiway division protocol and a multiway merging algorithm with a low number of branch mispredictions....

  8. Queue and stack sorting algorithm optimization and performance analysis

    Science.gov (United States)

    Qian, Mingzhu; Wang, Xiaobao

    2018-04-01

    Sorting algorithm is one of the basic operation of a variety of software development, in data structures course specializes in all kinds of sort algorithm. The performance of the sorting algorithm is directly related to the efficiency of the software. A lot of excellent scientific research queue is constantly optimizing algorithm, algorithm efficiency better as far as possible, the author here further research queue combined with stacks of sorting algorithms, the algorithm is mainly used for alternating operation queue and stack storage properties, Thus avoiding the need for a large number of exchange or mobile operations in the traditional sort. Before the existing basis to continue research, improvement and optimization, the focus on the optimization of the time complexity of the proposed optimization and improvement, The experimental results show that the improved effectively, at the same time and the time complexity and space complexity of the algorithm, the stability study corresponding research. The improvement and optimization algorithm, improves the practicability.

  9. Standard practice for cell sorting in a BSL-3 facility.

    Science.gov (United States)

    Perfetto, Stephen P; Ambrozak, David R; Nguyen, Richard; Roederer, Mario; Koup, Richard A; Holmes, Kevin L

    2011-01-01

    Over the past decade, there has been a rapid growth in the number of BSL-3 and BSL-4 laboratories in the USA and an increase in demand for infectious cell sorting in BSL-3 laboratories. In 2007, the International Society for Advancement of Cytometry (ISAC) Biosafety Committee published standards for the sorting of unfixed cells and is an important resource for biosafety procedures when performing infectious cell sorting. Following a careful risk assessment, if it is determined that a cell sorter must be located within a BSL-3 laboratory, there are a variety of factors to be considered prior to the establishment of the laboratory. This chapter outlines procedures for infectious cell sorting in a BSL-3 environment to facilitate the establishment and safe operation of a BSL-3 cell sorting laboratory. Subjects covered include containment verification, remote operation, disinfection, personal protective equipment (PPE), and instrument-specific modifications for enhanced aerosol evacuation.

  10. Development of a reactor thermalhydraulic experiment databank(SORTED1)

    International Nuclear Information System (INIS)

    Bang, Young Seck; Kim, Eun Kyoung; Kim, Hho Jung; Lee, Sang Yong

    1994-01-01

    The recent trend in thermalhydraulic safety analysis of nuclear power plant shows the best-estimate and probabilistic approaches, therefore, the verification of the best-estimate code based on the applicable experiment data has been required. The present study focused on developing a simple databank, SORTED1, to be effectively used for code verification. The development of SORTED1 includes a data collection from the various sources including ENCOUNTER, which is the reactor safety data bank of U.S. Nuclear Regulatory Commission, a reorganization of collected resources suitable for requirements of SORTED1 database management system (DBMS), and a development of a simple DBMS. The SORTED1 is designed in Unix environment with graphic user interface to improve a user convenience and has a capability to provide the test related information. The currently registered data in SORTED1 cover 759 thermalhydraulic tests including LOFT, Semiscale, etc

  11. A Comparison of Card-sorting Analysis Methods

    DEFF Research Database (Denmark)

    Nawaz, Ather

    2012-01-01

    This study investigates how the choice of analysis method for card sorting studies affects the suggested information structure for websites. In the card sorting technique, a variety of methods are used to analyse the resulting data. The analysis of card sorting data helps user experience (UX......) designers to discover the patterns in how users make classifications and thus to develop an optimal, user-centred website structure. During analysis, the recurrence of patterns of classification between users influences the resulting website structure. However, the algorithm used in the analysis influences...... the recurrent patterns found and thus has consequences for the resulting website design. This paper draws an attention to the choice of card sorting analysis and techniques and shows how it impacts the results. The research focuses on how the same data for card sorting can lead to different website structures...

  12. New insight into the solution structures of wheat gluten proteins from Raman optical activity

    DEFF Research Database (Denmark)

    Blanch, E.W.; Kasarda, D.D.; Hecht, L.

    2003-01-01

    Vibrational Raman optical activity (ROA) spectra of the wheat proteins a-gliadin (A-gliadin), omega-liadin, and a 30 kDa peptide called T-A-1 from the high molecular weight glutenin subunit (HMW-GS) Dx5 were measured to obtain new information about their solution structures. The spectral data show...... that, under the conditions investigated, A-gliadin contains a considerable amount of hydrated alpha-helix, most of which probably lies within a relatively structured C-terminal domain. Smaller quantities of beta-structure and poly(L-proline) II (PPII) helix were also identified. Addition of methanol...

  13. Side Chain and Flexibility Contributions to the Raman Optical Activity Spectra of a Model Cyclic Hexapeptide

    Czech Academy of Sciences Publication Activity Database

    Hudecová, J.; Kapitán, Josef; Baumruk, V.; Hammer, R. P.; Keiderling, T. A.; Bouř, Petr

    2010-01-01

    Roč. 114, č. 28 (2010), s. 7642-7651 ISSN 1089-5639 R&D Projects: GA ČR GA203/06/0420; GA ČR GA202/07/0732; GA AV ČR IAA400550702 Grant - others:GA UK(CZ) 126310 Institutional research plan: CEZ:AV0Z40550506 Keywords : Raman optical activity * ab initio * side chain * flexibility * peptide Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.732, year: 2010

  14. Correlation between stereochemistry and optical activity of chiral dimolybdenum tetracarboxylates and related compounds

    International Nuclear Information System (INIS)

    Klyagina, A.P.; Golovaneva, I.F.; Sadikova, G.G.

    1990-01-01

    Using one-electron model of optical activity sector rules for chiral tetracarboxylates of molybdenum and related compounds are derived. Correlation between the sign of the Cotton effect (CE) of δ-δ * -transition and stereochemistry of this type of binuclear clusters is expressed in the form of hexadecant rule, in which positive sign of CE corresponds to the negative sign of pseudoscalar function xyz(x 2 -y 2 ) of the cluster atoms. Negative sign of CE is predicted for δ-δ * -transition in cis-(L-isoleucine) 2 (NCS) 4 Mo 2

  15. Brain activation and connectivity of social cognition using diffuse optical imaging

    Science.gov (United States)

    Zhu, Banghe; Godavarty, Anuradha

    2009-02-01

    In the current research, diffuse optical imaging (DOI) is used for the first time towards studies related to sociocommunication impairments, which is a characteristic feature of autism. DOI studies were performed on normal adult volunteers to determine the differences in the brain activation (cognitive regions) in terms of the changes in the cerebral blood oxygenation levels in response to joint and non-joint attention based stimulus (i.e. socio-communicative paradigms shown as video clips). Functional connectivity models are employed to assess the extent of synchronization between the left and right pre-frontal regions of the brain in response to the above stimuli.

  16. A two-in-one Faraday rotator mirror exempt of active optical alignment.

    Science.gov (United States)

    Wan, Qiong; Wan, Zhujun; Liu, Hai; Liu, Deming

    2014-02-10

    A two-in-one Faraday rotator mirror was presented, which functions as two independent Faraday rotation mirrors with a single device. With the introduction of a reflection lens as substitution of the mirror in traditional structure, this device is characterized by exemption of active optical alignment for the designers and manufacturers of Faraday rotator mirrors. A sample was fabricated by passive mechanical assembly. The insertion loss was measured as 0.46 dB/0.50 dB for the two independent ports, respectively.

  17. Automatic online spike sorting with singular value decomposition and fuzzy C-mean clustering.

    Science.gov (United States)

    Oliynyk, Andriy; Bonifazzi, Claudio; Montani, Fernando; Fadiga, Luciano

    2012-08-08

    Understanding how neurons contribute to perception, motor functions and cognition requires the reliable detection of spiking activity of individual neurons during a number of different experimental conditions. An important problem in computational neuroscience is thus to develop algorithms to automatically detect and sort the spiking activity of individual neurons from extracellular recordings. While many algorithms for spike sorting exist, the problem of accurate and fast online sorting still remains a challenging issue. Here we present a novel software tool, called FSPS (Fuzzy SPike Sorting), which is designed to optimize: (i) fast and accurate detection, (ii) offline sorting and (iii) online classification of neuronal spikes with very limited or null human intervention. The method is based on a combination of Singular Value Decomposition for fast and highly accurate pre-processing of spike shapes, unsupervised Fuzzy C-mean, high-resolution alignment of extracted spike waveforms, optimal selection of the number of features to retain, automatic identification the number of clusters, and quantitative quality assessment of resulting clusters independent on their size. After being trained on a short testing data stream, the method can reliably perform supervised online classification and monitoring of single neuron activity. The generalized procedure has been implemented in our FSPS spike sorting software (available free for non-commercial academic applications at the address: http://www.spikesorting.com) using LabVIEW (National Instruments, USA). We evaluated the performance of our algorithm both on benchmark simulated datasets with different levels of background noise and on real extracellular recordings from premotor cortex of Macaque monkeys. The results of these tests showed an excellent accuracy in discriminating low-amplitude and overlapping spikes under strong background noise. The performance of our method is competitive with respect to other robust spike

  18. Automatic online spike sorting with singular value decomposition and fuzzy C-mean clustering

    Directory of Open Access Journals (Sweden)

    Oliynyk Andriy

    2012-08-01

    Full Text Available Abstract Background Understanding how neurons contribute to perception, motor functions and cognition requires the reliable detection of spiking activity of individual neurons during a number of different experimental conditions. An important problem in computational neuroscience is thus to develop algorithms to automatically detect and sort the spiking activity of individual neurons from extracellular recordings. While many algorithms for spike sorting exist, the problem of accurate and fast online sorting still remains a challenging issue. Results Here we present a novel software tool, called FSPS (Fuzzy SPike Sorting, which is designed to optimize: (i fast and accurate detection, (ii offline sorting and (iii online classification of neuronal spikes with very limited or null human intervention. The method is based on a combination of Singular Value Decomposition for fast and highly accurate pre-processing of spike shapes, unsupervised Fuzzy C-mean, high-resolution alignment of extracted spike waveforms, optimal selection of the number of features to retain, automatic identification the number of clusters, and quantitative quality assessment of resulting clusters independent on their size. After being trained on a short testing data stream, the method can reliably perform supervised online classification and monitoring of single neuron activity. The generalized procedure has been implemented in our FSPS spike sorting software (available free for non-commercial academic applications at the address: http://www.spikesorting.com using LabVIEW (National Instruments, USA. We evaluated the performance of our algorithm both on benchmark simulated datasets with different levels of background noise and on real extracellular recordings from premotor cortex of Macaque monkeys. The results of these tests showed an excellent accuracy in discriminating low-amplitude and overlapping spikes under strong background noise. The performance of our method is

  19. Card sorting to evaluate the robustness of the information architecture of a protocol website.

    Science.gov (United States)

    Wentzel, J; Müller, F; Beerlage-de Jong, N; van Gemert-Pijnen, J

    2016-02-01

    A website on Methicillin-Resistant Staphylococcus Aureus, MRSA-net, was developed for Health Care Workers (HCWs) and the general public, in German and in Dutch. The website's content was based on existing protocols and its structure was based on a card sort study. A Human Centered Design approach was applied to ensure a match between user and technology. In the current study we assess whether the website's structure still matches user needs, again via a card sort study. An open card sort study was conducted. Randomly drawn samples of 100 on-site search queries as they were entered on the MRSA-net website (during one year of use) were used as card input. In individual sessions, the cards were sorted by each participant (18 German and 10 Dutch HCWs, and 10 German and 10 Dutch members of the general public) into piles that were meaningful to them. Each participant provided a label for every pile of cards they created. Cluster analysis was performed on the resulting sorts, creating an overview of clusters of items placed together in one pile most frequently. In addition, pile labels were qualitatively analyzed to identify the participants' mental models. Cluster analysis confirmed existing categories and revealed new themes emerging from the search query samples, such as financial issues and consequences for the patient. Even though MRSA-net addresses these topics, they are not prominently covered in the menu structure. The label analysis shows that 7 of a total of 44 MRSA-net categories were not reproduced by the participants. Additional themes such as information on other pathogens and categories such as legal issues emerged. This study shows that the card sort performed to create MRSA-net resulted in overall long-lasting structure and categories. New categories were identified, indicating that additional information needs emerged. Therefore, evaluating website structure should be a recurrent activity. Card sorting with ecological data as input for the cards is

  20. Cellular and colloidal separation using optical forces

    Czech Academy of Sciences Publication Activity Database

    Dholakia, K.; MacDonald, M. P.; Zemánek, Pavel; Čižmár, Tomáš

    2007-01-01

    Roč. 82, - (2007), s. 467-495 ISSN 0091-679X R&D Projects: GA MŠk(CZ) LC06007 EU Projects: European Commission(XE) 508952 - ATOM3D Institutional research plan: CEZ:AV0Z20650511 Keywords : optical sorting * FACS * MACS * optical forces * dielectrophoresis * optical chromatography * optical manipulation Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.582, year: 2006

  1. Active learning of geometrical optics in high school: the ALOP approach

    Science.gov (United States)

    Alborch, Alejandra; Pandiella, Susana; Benegas, Julio

    2017-09-01

    A group comparison experiment of two high school classes with pre and post instruction testing has been carried out to study the suitability and advantages of using the active learning of optics and photonics (ALOP) curricula in high schools of developing countries. Two parallel, mixed gender, 12th grade classes of a high school run by the local university were chosen. One course was randomly selected to follow the experimental instruction, based on teacher and student activities contained in the ALOP Manual. The other course followed the traditional, teacher-centered, instruction previously practiced. Conceptual knowledge of the characteristics of image formation by plane mirrors and single convergent and divergent lenses was measured by applying, in both courses, the multiple-choice test, light and optics conceptual evaluation (LOCE). Measurement before instruction showed that initial knowledge was almost null, and therefore equivalent, in both courses. After instruction testing showed that the conceptual knowledge of students following the ALOP curricula more than doubled that achieved by students in the control course, a situation maintained throughout the six conceptual dimensions tested by the 34 questions of the LOCE test used in this experiment. Using a 60% performance level on the LOCE test as the threshold of satisfactory performance, most (about 90%) of the experimental group achieved this level—independent of initial knowledge, while no student following traditional instruction reached this level of understanding. Some considerations and recommendations for prospective users are also included.

  2. Optically active polyurethane@indium tin oxide nanocomposite: Preparation, characterization and study of infrared emissivity

    International Nuclear Information System (INIS)

    Yang, Yong; Zhou, Yuming; Ge, Jianhua; Yang, Xiaoming

    2012-01-01

    Highlights: ► Silane coupling agent of KH550 was used to connect the ITO and polyurethanes. ► Infrared emissivity values of the hybrids were compared and analyzed. ► Interfacial synergistic action and orderly secondary structure were the key factors. -- Abstract: Optically active polyurethane@indium tin oxide and racemic polyurethane@indium tin oxide nanocomposites (LPU@ITO and RPU@ITO) were prepared by grafting the organics onto the surfaces of modified ITO nanoparticles. LPU@ITO and RPU@ITO composites based on the chiral and racemic tyrosine were characterized by FT-IR, UV–vis spectroscopy, X-ray diffraction (XRD), SEM, TEM, and thermogravimetric analysis (TGA), and the infrared emissivity values (8–14 μm) were investigated in addition. The results indicated that the polyurethanes had been successfully grafted onto the surfaces of ITO without destroying the crystalline structure. Both composites possessed the lower infrared emissivity values than the bare ITO nanoparticles, which indicated that the interfacial interaction had great effect on the infrared emissivity. Furthermore, LPU@ITO based on the optically active polyurethane had the virtue of regular secondary structure and more interfacial synergistic actions between organics and inorganics, thus it exhibited lower infrared emissivity value than RPU@ITO based on the racemic polyurethane.

  3. Helical polyurethane-attapulgite nanocomposite: Preparation, characterization and study of optical activity

    International Nuclear Information System (INIS)

    Wang Zhiqiang; Zhou Yuming; Sun Yanqing; Fan Kai; Guo Xingxing; Jiang Xiaolei

    2009-01-01

    Helical polyurethane-attapulgite (BM-ATT) based on R-1,1'-binaphthyl-2',2-diol (R-BINOL) composite was prepared after the surface modification of attapulgite (ATT). BM-ATT was characterized by Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HTEM) and vibrational circular dichroism (VCD) spectroscopy. FT-IR and XRD analyses indicate that the helical polyurethane has been successfully grafted onto the surfaces of the modified ATT without destroying the original crystalline structure of ATT. BM-ATT exhibits the rod-like structure by SEM, TEM, and HTEM photographs. BM-ATT displays obvious Cotton effect for some absorbance in VCD spectrum, and its optical activity results from the singlehanded conformation of helical polyurethane. - Graphical Abstract: Helical polyurethane-attapulgite (BM-ATT) based on R-1,1'-binaphthyl-2',2-diol (R-BINOL) nanocomposite was prepared after surface modification of attapulgite (ATT). This rod-like composite is coated by the optically active polyurethane shell on the surfaces.

  4. Difference frequency generation spectroscopy as a vibrational optical activity measurement tool.

    Science.gov (United States)

    Cheon, Sangheon; Cho, Minhaeng

    2009-03-19

    Vibrational optical activity (VOA) of chiral molecules in condensed phases can be studied by using vibrational circular dichroism and Raman optical activity measurement techniques. Recently, IR-vis sum frequency generation has shown to be an alternative VOA measurement method. Such a three-wave-mixing method employing a polarization modulation technique can be a potentially useful VOA measurement tool. Here, a theoretical description of difference frequency generation (DFG) employing circularly polarized visible radiations is presented. Frequency scanning to obtain a VOA-DFG spectrum is achieved by controlling the difference between the two electronically nonresonant incident radiation frequencies. If the two incident beams are linearly polarized and their polarization directions are perpendicular to each other, one can selectively measure the all-electric-dipole-allowed chiral component of the DFG susceptibility. In addition, by using circularly polarized beams and taking the DFG difference intensity signal, which is defined as the difference between left and right circularly polarized DFG signals, additional chiral susceptibility components originating from the electric quadrupole transition can be measured. The DFG as a novel VOA measurement technique for solution samples containing chiral molecules will therefore be a useful coherent spectroscopic tool for determining absolute configuration of chiral molecules in condensed phases.

  5. Ring-shaped active mode-locked tunable laser using quantum-dot semiconductor optical amplifier

    Science.gov (United States)

    Zhang, Mingxiao; Wang, Yongjun; Liu, Xinyu

    2018-03-01

    In this paper, a lot of simulations has been done for ring-shaped active mode-locked lasers with quantum-dot semiconductor optical amplifier (QD-SOA). Based on the simulation model of QD-SOA, we discussed about the influence towards mode-locked waveform frequency and pulse caused by QD-SOA maximum mode peak gain, active layer loss coefficient, bias current, incident light pulse, fiber nonlinear coefficient. In the meantime, we also take the tunable performance of the laser into consideration. Results showed QD-SOA a better performance than original semiconductor optical amplifier (SOA) in recovery time, line width, and nonlinear coefficients, which makes it possible to output a locked-mode impulse that has a higher impulse power, narrower impulse width as well as the phase is more easily controlled. After a lot of simulations, this laser can realize a 20GHz better locked-mode output pulse after 200 loops, where the power is above 17.5mW, impulse width is less than 2.7ps, moreover, the tunable wavelength range is between 1540nm-1580nm.

  6. Laser-based optical activity detection of amino acids and proteins

    Energy Technology Data Exchange (ETDEWEB)

    Reitsma, B.H.

    1987-01-01

    The optical activity detector (OAD) for HPLC is a selective detector for optically active substances including amino acids and proteins. This study illustrates the use of the OAD in three related areas. Section I illustrates the separation of four free amino acids using cation-exchange chromatography. Detection by coupling the OAD to a refractive index detector (RI) for proline and threonine and the OAD to an ultraviolet absorbance detector (UV) for tyrosine and phenylalanine allows the calculation of enantiomeric (D/L) ratios of these amino acids without physical separation. Specific rotations of these four amino acids are also reported. Section II illustrates the separation of 16 dansyl-L-amino acids by RP-HPLC with detection by OA/UV. Section III illustrates the RP-HPLC separation of conformers of soybean trypsin inhibitor. Detection by OA/UV provides insights from the chromatogram unavailable for UV absorbance detection alone. In addition, identification of impurities is simplified with OA/UV. Specific rotations of the separated protein fractions show no significant change accompanying change in conformation.

  7. Development of Optically Active Nanostructures for Potential Applications in Sensing, Therapeutics and Imaging

    Science.gov (United States)

    Joshi, Padmanabh

    Materials at nanoscale are finding manifold applications in the various fields like sensing, plasmonics, therapeutics, to mention a few. Large amount of development has taken place regarding synthesis and exploring the novel applications of the various types of nanomaterials like organic, inorganic and hybrid of both. Yet, it is believed that the full potential of different nanomaterials is yet to be fully established stimulating researchers to explore more in the field of nanotechnology. Building on the same premise, in the following studies we have developed the nanomaterials in the class of optically active nanoparticles. First part of the study we have successfully designed, synthesized, and characterized Ag-Fe3O4 nanocomposite substrate for potential applications in quantitative Surface Enhanced Raman Scattering (SERS) measurements. Quantitative SERS-based detection of dopamine was performed successfully. In subsequent study, facile, single-step synthesis of polyethyleneimine (PEI) coated lanthanide based NaYF4 (Yb, Er) nanoparticles was developed and their application as potential photodynamic therapy agent was studied using excitations by light in near infra-red and visible region. In the following and last study, synthesis and characterization of the conjugated polymer nanoparticles was attempted successfully. Functionalization of the conjugated nanoparticles, which is a bottleneck for their potential applications, was successfully performed by encapsulating them in the silica nanoparticles, surface of which was then functionalized by amine group. Three types of optically active nanoparticles were developed for potential applications in sensing, therapeutics and imaging.

  8. Nonplanar tertiary amides in rigid chiral tricyclic dilactams. Peptide group distortions and vibrational optical activity.

    Science.gov (United States)

    Pazderková, Markéta; Profant, Václav; Hodačová, Jana; Sebestík, Jaroslav; Pazderka, Tomáš; Novotná, Pavlína; Urbanová, Marie; Safařík, Martin; Buděšínský, Miloš; Tichý, Miloš; Bednárová, Lucie; Baumruk, Vladimír; Maloň, Petr

    2013-08-22

    We investigate amide nonplanarity in vibrational optical activity (VOA) spectra of tricyclic spirodilactams 5,8-diazatricyclo[6,3,0,0(1,5)]undecan-4,9-dione (I) and its 6,6',7,7'-tetradeuterio derivative (II). These rigid molecules constrain amide groups to nonplanar geometries with twisted pyramidal arrangements of bonds to amide nitrogen atoms. We have collected a full range vibrational circular dichroism (VCD) and Raman optical activity (ROA) spectra including signals of C-H and C-D stretching vibrations. We report normal-mode analysis and a comparison of calculated to experimental VCD and ROA. The data provide band-to-band assignment and offer a possibility to evaluate roles of constrained nonplanar tertiary amide groups and rigid chiral skeletons. Nonplanarity shows as single-signed VCD and ROA amide I signals, prevailing the couplets expected to arise from the amide-amide interaction. Amide-amide coupling dominates amide II (mainly C'-N stretching, modified in tertiary amides by the absence of a N-H bond) transitions (strong couplet in VCD, no significant ROA) probably due to the close proximity of amide nitrogen atoms. At lower wavenumbers, ROA spectra exhibit another likely manifestation of amide nonplanarity, showing signals of amide V (δ(oop)(N-C) at ~570 cm(-1)) and amide VI (δ(oop)(C'═O) at ~700 cm(-1) and ~650 cm(-1)) vibrations.

  9. Identification of prefrontal cortex (BA10) activation while performing Stroop test using diffuse optical tomography

    Science.gov (United States)

    Khadka, Sabin; Chityala, Srujan R.; Tian, Fenghua; Liu, Hanli

    2011-03-01

    Stroop test is commonly used as a behavior-testing tool for psychological examinations that are related to attention and cognitive control of the human brain. Studies have shown activations in Broadmann area 10 (BA10) of prefrontal cortex (PFC) during attention and cognitive process. The use of diffuse optical tomography (DOT) for human brain mapping is becoming more prevalent. In this study we expect to find neural correlates between the performed cognitive tasks and hemodynamic signals detected by a DOT system. Our initial observation showed activation of oxy-hemoglobin concentration in BA 10, which is consistent with some results seen by positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). Our study demonstrates the possibility of combining DOT with Stroop test to quantitatively investigate cognitive functions of the human brain at the prefrontal cortex.

  10. Four-Wave Optical Parametric Amplification in a Raman-Active Gas

    Directory of Open Access Journals (Sweden)

    Yuichiro Kida

    2015-08-01

    Full Text Available Four-wave optical parametric amplification (FWOPA in a Raman-active medium is experimentally investigated by use of an air-filled hollow fiber. A femtosecond pump pulse shorter than the period of molecular motion excites the coherent molecular motion of the Raman-active molecules during the parametric amplification of a signal pulse. The excited coherent motion modulates the frequency of the signal pulse during the parametric amplification, and shifts it to lower frequencies. The magnitude of the frequency redshift depends on the pump intensity, resulting in intensity-dependent spectral characteristics that are different from those in the FWOPA induced in a noble-gas-filled hollow fiber.

  11. Impact of slow-light enhancement on optical propagation in active semiconductor photonic crystal waveguides

    DEFF Research Database (Denmark)

    Chen, Yaohui; de Lasson, Jakob Rosenkrantz; Gregersen, Niels

    2015-01-01

    We derive and validate a set of coupled Bloch wave equations for analyzing the reflection and transmission properties of active semiconductor photonic crystal waveguides. In such devices, slow-light propagation can be used to enhance the material gain per unit length, enabling, for example......, the realization of short optical amplifiers compatible with photonic integration. The coupled wave analysis is compared to numerical approaches based on the Fourier modal method and a frequency domain finite element technique. The presence of material gain leads to the build-up of a backscattered field, which...... is interpreted as distributed feedback effects or reflection at passive-active interfaces, depending on the approach taken. For very large material gain values, the band structure of the waveguide is perturbed, and deviations from the simple coupled Bloch wave model are found....

  12. The Container Problem in Bubble-Sort Graphs

    Science.gov (United States)

    Suzuki, Yasuto; Kaneko, Keiichi

    Bubble-sort graphs are variants of Cayley graphs. A bubble-sort graph is suitable as a topology for massively parallel systems because of its simple and regular structure. Therefore, in this study, we focus on n-bubble-sort graphs and propose an algorithm to obtain n-1 disjoint paths between two arbitrary nodes in time bounded by a polynomial in n, the degree of the graph plus one. We estimate the time complexity of the algorithm and the sum of the path lengths after proving the correctness of the algorithm. In addition, we report the results of computer experiments evaluating the average performance of the algorithm.

  13. Automorphism group of the modified bubble-sort graph

    OpenAIRE

    Ganesan, Ashwin

    2014-01-01

    The modified bubble-sort graph of dimension $n$ is the Cayley graph of $S_n$ generated by $n$ cyclically adjacent transpositions. In the present paper, it is shown that the automorphism group of the modified bubble sort graph of dimension $n$ is $S_n \\times D_{2n}$, for all $n \\ge 5$. Thus, a complete structural description of the automorphism group of the modified bubble-sort graph is obtained. A similar direct product decomposition is seen to hold for arbitrary normal Cayley graphs generate...

  14. Design and analysis on sorting blade for automated size-based sorting device

    Science.gov (United States)

    Razali, Zol Bahri; Kader, Mohamed Mydin M. Abdul; Samsudin, Yasser Suhaimi; Daud, Mohd Hisam

    2017-09-01

    Nowadays rubbish separating or recycling is a main problem of nation, where peoples dumped their rubbish into dumpsite without caring the value of the rubbish if it can be recycled and reused. Thus the author proposed an automated segregating device, purposely to teach people to separate their rubbish and value the rubbish that can be reused. The automated size-based mechanical segregating device provides significant improvements in terms of efficiency and consistency in this segregating process. This device is designed to make recycling easier, user friendly, in the hope that more people will take responsibility if it is less of an expense of time and effort. This paper discussed about redesign a blade for the sorting device which is to develop an efficient automated mechanical sorting device for the similar material but in different size. The machine is able to identify the size of waste and it depends to the coil inside the container to separate it out. The detail design and methodology is described in detail in this paper.

  15. A real time sorting algorithm to time sort any deterministic time disordered data stream

    Science.gov (United States)

    Saini, J.; Mandal, S.; Chakrabarti, A.; Chattopadhyay, S.

    2017-12-01

    In new generation high intensity high energy physics experiments, millions of free streaming high rate data sources are to be readout. Free streaming data with associated time-stamp can only be controlled by thresholds as there is no trigger information available for the readout. Therefore, these readouts are prone to collect large amount of noise and unwanted data. For this reason, these experiments can have output data rate of several orders of magnitude higher than the useful signal data rate. It is therefore necessary to perform online processing of the data to extract useful information from the full data set. Without trigger information, pre-processing on the free streaming data can only be done with time based correlation among the data set. Multiple data sources have different path delays and bandwidth utilizations and therefore the unsorted merged data requires significant computational efforts for real time manifestation of sorting before analysis. Present work reports a new high speed scalable data stream sorting algorithm with its architectural design, verified through Field programmable Gate Array (FPGA) based hardware simulation. Realistic time based simulated data likely to be collected in an high energy physics experiment have been used to study the performance of the algorithm. The proposed algorithm uses parallel read-write blocks with added memory management and zero suppression features to make it efficient for high rate data-streams. This algorithm is best suited for online data streams with deterministic time disorder/unsorting on FPGA like hardware.

  16. An extensible infrastructure for fully automated spike sorting during online experiments.

    Science.gov (United States)

    Santhanam, Gopal; Sahani, Maneesh; Ryu, Stephen; Shenoy, Krishna

    2004-01-01

    When recording extracellular neural activity, it is often necessary to distinguish action potentials arising from distinct cells near the electrode tip, a process commonly referred to as "spike sorting." In a number of experiments, notably those that involve direct neuroprosthetic control of an effector, this cell-by-cell classification of the incoming signal must be achieved in real time. Several commercial offerings are available for this task, but all of these require some manual supervision per electrode, making each scheme cumbersome with large electrode counts. We present a new infrastructure that leverages existing unsupervised algorithms to sort and subsequently implement the resulting signal classification rules for each electrode using a commercially available Cerebus neural signal processor. We demonstrate an implementation of this infrastructure to classify signals from a cortical electrode array, using a probabilistic clustering algorithm (described elsewhere). The data were collected from a rhesus monkey performing a delayed center-out reach task. We used both sorted and unsorted (thresholded) action potentials from an array implanted in pre-motor cortex to "predict" the reach target, a common decoding operation in neuroprosthetic research. The use of sorted spikes led to an improvement in decoding accuracy of between 3.6 and 6.4%.

  17. Application of Quality Function Deployment (QFD) method and kano model to redesign fresh fruit bunches sorting tool

    Science.gov (United States)

    Anizar; Siregar, I.; Yahya, I.; Yesika, N.

    2018-02-01

    The activity of lowering fresh fruit bunches (FFB) from truck to sorting floor is performed manually by workers using a sorting tool. Previously, the sorting tool used is a pointed iron bar with a T-shaped handle. Changes made to the sorting tool causes several complaints on worker and affect the time to lower the fruit. The purpose of this article is to obtain the design of an FFB sorting tool that suits the needs of these workers by applying the Quality Function Deployment (QFD) and Kano Model methods. Both of the two methods will be integrated to find the design that matches workers’ image and psychological feeling. The main parameters are to obtain the customer requirements of the palm fruit loading workers, to find the most important technical characteristics and critical part affecting the quality of the FFB sorting tool. The customer requirements of the palm loading workers are the following : the color of the coating paint is gray, the bar material is made of stainless pipe, the main grip coating material is made of grip, the tip material is made of the spring steel, the additional grip is made of rubber and the handle is of triangular shape.

  18. Let’s limit our waste production and let’s’ sort it!

    CERN Multimedia

    HSE Unit

    2013-01-01

    Let’s limit our waste production! – Why ? Preventing the production of waste is the best solution to avoid environmental issues, economic impacts and technical constraints. So, whenever you are involved in the design, manufacturing, distribution, use or dismantling of a product or an activity in general, always remember that the best waste is that which is not produced. The limitation of waste production being an HSE objective declared in 2013 by the CERN Director-General, we encourage everyone to help limit the amount of waste produced through CERN activities. Let’s sort it! – Why ? Since the 90s, CERN has implemented a policy to promote recovery of the waste* generated by its activities. Nowadays, CERN is committed to continuously improving its sorting and recovery and therefore various initiatives have been started by GS-IS to improve the recovery of waste (e.g. recovery of organic waste from restaurants; implementation of solar trash compactors - see Bulletin 27-...

  19. Active functional devices using parity-time symmetry optics (Conference Presentation)

    Science.gov (United States)

    Brac de la Perriere, Vincent; Benisty, Henri; Ramdane, Abderrahim; Lupu, Anatole

    2017-05-01

    The progress of nanotechnologies has triggered the emergence of many photonic artificial structures: photonic crystals, metamaterials, plasmonic resonators. Recently the intriguing class of PT-symmetric devices, referring to Parity-Time symmetry [1] has attracted much attention. The characteristic feature of PT-symmetry is that the structures' refractive index profile is complex-valued due to the presence of alternating gain and loss regions in the system. Apart from fundamental research motivations, the tremendous interest in these artificial systems is strongly driven by the practical outcomes expected to foster a new generation of tunable, reconfigurable and non-reciprocal devices. The principle of gain-loss modulation lying in the heart of PT-symmetry optics enables a range of innovative solutions in the field of integrated optics at 1.5μm [2-7]. By using PT-symmetric coupled waveguides and Bragg reflectors as fundamental building blocks, it is possible to build a wide variety of functional optical devices. The PT-symmetry principle provides an alternative way for the realization of active devices that could become functional in a new platform for integrated optics. For instance one major bottleneck of the III-V/Si hybrid integration approach is that each type of active devices (laser, modulator, etc) requires a specific composition of III-V semiconductor alloy, involving a variety of (re)growth challenges. The advantage of the PT-symmetry solution is that the fabrication of all these devices can be done with a single stack of III-V semiconductor alloys that greatly simplifies the technological process. The aim of the current contribution is to provide a survey of the most promising applications of PT-symmetry in photonics with a particular emphases on the transition from theoretical concepts to experimental devices. The intention is to draw attention to the risks and issues related to the practical implementation that are most often overlooked in the basic

  20. Emergence of Nonlinear Optical Activity by Incorporation of a Linker Carrying the p-Nitroaniline Motif in MIL-53 Frameworks

    NARCIS (Netherlands)

    Markey, Karen; Krüger, Martin; Seidler, Tomasz; Reinsch, Helge; Verbiest, Thierry; De Vos, Dirk E.; Champagne, Benoît; Stock, Norbert; van der Veen, M.A.

    2017-01-01

    p-Nitroaniline presents the typical motif of a second-order nonlinear optically (NLO) active molecule. However, because of its crystallization in an antiparallel and hence centrosymmetric structure, the NLO activity is lost. In this contribution, the p-nitroaniline motif was built successfully

  1. Active photonic sensor communication cable for field application of optical data and power transmission

    Science.gov (United States)

    Suthau, Eike; Rieske, Ralf; Zerna, Thomas

    2014-10-01

    Omitting electrically conducting wires for sensor communication and power supply promises protection for sensor systems and monitored structures against lightning or high voltages, prevention of explosion hazards, and reduction of susceptibility to tampering. The ability to photonically power remote systems opens up the full range of electrical sensors. Power-over-fiber is an attractive option in electromagnetically sensitive environments, particularly for longterm, maintenance-free applications. It can deliver uninterrupted power sufficient for elaborate sensors, data processing or even actuators alongside continuous high speed data communication for remote sensor application. This paper proposes an active photonic sensor communication system, which combines the advantages of optical data links in terms of immunity to electromagnetic interference (EMI), high bandwidth, hardiness against tampering or eavesdropping, and low cable weight with the robustness one has come to expect from industrial or military electrical connectors. An application specific integrated circuit (ASIC) is presented that implements a closed-loop regulation of the sensor power supply to guarantee continuous, reliable data communications while maintaining a highly efficient, adaptive sensor supply scheme. It is demonstrated that the resulting novel photonic sensor communication cable can handle sensors and actuators differing orders of magnitude with respect to power consumption. The miniaturization of the electro-optical converters and driving electronics is as important to the presented development as the energy efficiency of the detached, optically powered sensor node. For this reason, a novel photonic packaging technology based on wafer-level assembly of the laser power converters by means of passive alignment will be disclosed in this paper.

  2. Sleeping dendrites: fiber-optic measurements of dendritic calcium activity in freely moving and sleeping animals

    Directory of Open Access Journals (Sweden)

    Julie Seibt

    2014-03-01

    Full Text Available Dendrites are the post-synaptic sites of most excitatory and inhibitory synapses in the brain, making them the main location of cortical information processing and synaptic plasticity. Although current hypotheses suggest a central role for sleep in proper cognitive function and brain plasticity, virtually nothing is known about changes in dendritic activity across the sleep-wake cycle and how waking experience modifies this activity. To start addressing these questions, we developed a method that allows long-term recordings of EEGs/EMG combined with in vivo cortical calcium (Ca2+ activity in freely moving and sleeping rats. We measured Ca2+ activity from populations of dendrites of layer (L 5 pyramidal neurons (n = 13 rats that we compared with Ca2+ activity from populations of neurons in L2/3 (n = 11 rats. L5 and L2/3 neurons were labelled using bolus injection of OGB1-AM or GCaMP6 (1. Ca2+ signals were detected using a fiber-optic system (cannula diameter = 400µm, transmitting the changes in fluorescence to a photodiode. Ca2+ fluctuations could then be correlated with ongoing changes in brain oscillatory activity during 5 major brain states: active wake [AW], quiet wake [QW], NREM, REM and NREM-REM transition (or intermediate state, [IS]. Our Ca2+ recordings show large transients in L5 dendrites and L2/3 neurons that oscillate predominantly at frequencies In summary, we show that this technique is successful in monitoring fluctuations in ongoing dendritic Ca2+ activity during natural brain states and allows, in principle, to combine behavioral measurement with imaging from various brain regions (e.g. deep structures in freely behaving animals. Using this method, we show that Ca2+ transients from populations of L2/3 neurons and L5 dendrites are deferentially regulated across the sleep/wake cycle, with dendritic activity being the highest during the IS sleep. Our correlation analysis suggests that specific sleep EEG activity during NREM and IS

  3. Soil Water Measurement Using Actively Heated Fiber Optics at Field Scale.

    Science.gov (United States)

    Vidana Gamage, Duminda N; Biswas, Asim; Strachan, Ian B; Adamchuk, Viacheslav I

    2018-04-06

    Several studies have demonstrated the potential of actively heated fiber optics (AHFO) to measure soil water content (SWC) at high spatial and temporal resolutions. This study tested the feasibility of the AHFO technique to measure soil water in the surface soil of a crop grown field over a growing season using an in-situ calibration approach. Heat pulses of five minutes duration were applied at a rate of 7.28 W m -1 along eighteen fiber optic cable transects installed at three depths (0.05, 0.10 and 0.20 m) at six-hour intervals. Cumulative temperature increase (T cum ) during heat pulses was calculated at locations along the cable. While predicting commercial sensor measurements, the AHFO showed root mean square errors (RMSE) of 2.8, 3.7 and 3.7% for 0.05, 0.10 and 0.20 m depths, respectively. Further, the coefficients of determination (R²) for depth specific relationships were 0.87 (0.05 m depth), 0.46 (0.10 m depth), 0.86 (0.20 m depth) and 0.66 (all depths combined). This study showed a great potential of the AHFO technique to measure soil water at high spatial resolutions (<1 m) and to monitor soil water dynamics of surface soil in a crop grown field over a cropping season with a reasonable compromise between accuracy and practicality.

  4. Improvements in brain activation detection using time-resolved diffuse optical means

    Science.gov (United States)

    Montcel, Bruno; Chabrier, Renee; Poulet, Patrick

    2005-08-01

    An experimental method based on time-resolved absorbance difference is described. The absorbance difference is calculated over each temporal step of the optical signal with the time-resolved Beer-Lambert law. Finite element simulations show that each step corresponds to a different scanned zone and that cerebral contribution increases with the arrival time of photons. Experiments are conducted at 690 and 830 nm with a time-resolved system consisting of picosecond laser diodes, micro-channel plate photo-multiplier tube and photon counting modules. The hemodynamic response to a short finger tapping stimulus is measured over the motor cortex. Time-resolved absorbance difference maps show that variations in the optical signals are not localized in superficial regions of the head, which testify for their cerebral origin. Furthermore improvements in the detection of cerebral activation is achieved through the increase of variations in absorbance by a factor of almost 5 for time-resolved measurements as compared to non-time-resolved measurements.

  5. Development of a new catalase activity assay for biological samples using optical CUPRAC sensor.

    Science.gov (United States)

    Bekdeşer, Burcu; Özyürek, Mustafa; Güçlü, Kubilay; Alkan, Fulya Üstün; Apak, Reşat

    2014-11-11

    A novel catalase activity assay was developed for biological samples (liver and kidney tissue homogenates) using a rapid and low-cost optical sensor-based 'cupric reducing antioxidant capacity' (CUPRAC) method. The reagent, copper(II)-neocuproine (Cu(II)-Nc) complex, was immobilized onto a cation-exchanger film of Nafion, and the absorbance changes associated with the formation of the highly-colored Cu(I)-Nc chelate as a result of reaction with hydrogen peroxide (H2O2) was measured at 450 nm. When catalase was absent, H2O2 produced the CUPRAC chromophore, whereas catalase, being an effective H2O2 scavenger, completely annihilated the CUPRAC signal due to H2O2. Thus, the CUPRAC absorbance due to H2O2 oxidation concomitant with Cu(I)-Nc formation decreased proportionally with catalase. The developed sensor gave a linear response over a wide concentration range of H2O2 (0.68-78.6 μM). This optical sensor-based method applicable to tissue homogenates proved to be efficient for low hydrogen peroxide concentrations (physiological and nontoxic levels) to which the widely used UV method is not accurately responsive. Thus, conventional problems of the UV method arising from relatively low sensitivity and selectivity, and absorbance disturbance due to gaseous oxygen evolution were overcome. The catalase findings of the proposed method for tissue homogenates were statistically alike with those of HPLC. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Circular dichroism and Raman optical activity in antiferromagnetic transition metal fluorides

    International Nuclear Information System (INIS)

    Hoffman, K.R.; Lockwood, D.J.; Yen, W.M.

    2005-01-01

    The Raman optical activity (ROA) of magnons in rutile-structure antiferromagnetic FeF 2 (T N = 78 K) has been studied as a function of temperature and applied magnetic field. For exciting light incident along the c axis, ROA is observed for magnons but not for phonons. In zero field, a small splitting (0.09 cm -1 ) of the two acoustic-magnon branches is observed for the first time by inelastic light scattering. The splitting in applied magnetic field is found to reduce with increasing temperature in accordance with theory. No ROA was detected for two-magnon excitations. In optical absorption measurements performed over thirty years ago, a very small circular dichroism (CD) was observed in the magnon sidebands of other simple rutile antiferromagnetic fluorides (MnF 2 and CoF 2 ). The origin of this CD was not understood at the time. The Raman studies of the one-magnon Raman scattering in FeF 2 have demonstrated that in zero field the degeneracy of the antiferromagnetic magnon branches is lifted by a weak magnetic dipole-dipole interaction, as predicted by Pincus and Loudon and by White four decades ago. The source of the observed CD in the magnon sidebands can now be traced to this same magnetic-dipole induced splitting

  7. Isotope effect in heavy/light water suspensions of optically active gold nanoparticles

    Science.gov (United States)

    Kutsenko, V. Y.; Artykulnyi, O. P.; Petrenko, V. I.; Avdeev, M. V.; Marchenko, O. A.; Bulavin, L. A.; Snegir, S. V.

    2018-04-01

    Aqueous suspensions of optically active gold nanoparticles coated with trisodium citrate were synthesized in light (H2O) water and mixture of light and heavy (H2O/D2O) water using the modified Turkevich protocol. The objective of the paper was to verify sensitivity of neutron scattering methods (in particular, neutron reflectometry) to the potential isotope H/D substitution in the stabilizing organic shell around particles in colloidal solutions. First, the isotope effect was studied with respect to the changes in the structural properties of metal particles (size, shape, crystalline morphology) in solutions by electron microscopy including high-resolution transmission electron microscopy from dried systems. The structural factors determining the variation in the adsorption spectra in addition to the change in the optical properties of surrounding medium were discussed. Then, neutron reflectometry was applied to the layered nanoparticles anchored on a silicon wafer via 3-aminopropyltriethoxysilane molecules to reveal the presence of deuterated water molecules in the shell presumably formed by citrate molecules around the metallic core.

  8. Applied optics

    International Nuclear Information System (INIS)

    Orszag, A.; Antonetti, A.

    1988-01-01

    The 1988 progress report, of the Applied Optics laboratory, of the (Polytechnic School, France), is presented. The optical fiber activities are focused on the development of an optical gyrometer, containing a resonance cavity. The following domains are included, in the research program: the infrared laser physics, the laser sources, the semiconductor physics, the multiple-photon ionization and the nonlinear optics. Investigations on the biomedical, the biological and biophysical domains are carried out. The published papers and the congress communications are listed [fr

  9. Robot-assisted motor activation monitored by time-domain optical brain imaging

    Science.gov (United States)

    Steinkellner, O.; Wabnitz, H.; Schmid, S.; Steingräber, R.; Schmidt, H.; Krüger, J.; Macdonald, R.

    2011-07-01

    Robot-assisted motor rehabilitation proved to be an effective supplement to conventional hand-to-hand therapy in stroke patients. In order to analyze and understand motor learning and performance during rehabilitation it is desirable to develop a monitor to provide objective measures of the corresponding brain activity at the rehabilitation progress. We used a portable time-domain near-infrared reflectometer to monitor the hemodynamic brain response to distal upper extremity activities. Four healthy volunteers performed two different robot-assisted wrist/forearm movements, flexion-extension and pronation-supination in comparison with an unassisted squeeze ball exercise. A special headgear with four optical measurement positions to include parts of the pre- and postcentral gyrus provided a good overlap with the expected activation areas. Data analysis based on variance of time-of-flight distributions of photons through tissue was chosen to provide a suitable representation of intracerebral signals. In all subjects several of the four detection channels showed a response. In some cases indications were found of differences in localization of the activated areas for the various tasks.

  10. Efficient sorting of Bessel beams [Conference paper

    CSIR Research Space (South Africa)

    Mhlanga, T

    2013-02-01

    Full Text Available measured in entanglement and shown an increased spiral bandwidth17. Exploiting these properties of Bessel beams will make them very useful in the field of long-range, broad bandwidth communication systems. However, in order for these fields to be a... success in the area of optical communication, efficient techniques for extracting the information they carry (i.e. their azimuthal mode indices) need to exist. The ‘fork’ diffraction grating can be used to couple light of a particular OAM state into a...

  11. Acoustic bubble sorting for ultrasound contrast agent enrichment.

    Science.gov (United States)

    Segers, Tim; Versluis, Michel

    2014-05-21

    An ultrasound contrast agent (UCA) suspension contains encapsulated microbubbles with a wide size distribution, with radii ranging from 1 to 10 μm. Medical transducers typically operate at a single frequency, therefore only a small selection of bubbles will resonate to the driving ultrasound pulse. Thus, the sensitivity can be improved by narrowing down the size distribution. Here, we present a simple lab-on-a-chip method to sort the population of microbubbles on-chip using a traveling ultrasound wave. First, we explore the physical parameter space of acoustic bubble sorting using well-defined bubble sizes formed in a flow-focusing device, then we demonstrate successful acoustic sorting of a commercial UCA. This novel sorting strategy may lead to an overall improvement of the sensitivity of contrast ultrasound by more than 10 dB.

  12. Sorting on STAR. [CDC computer algorithm timing comparison

    Science.gov (United States)

    Stone, H. S.

    1978-01-01

    Timing comparisons are given for three sorting algorithms written for the CDC STAR computer. One algorithm is Hoare's (1962) Quicksort, which is the fastest or nearly the fastest sorting algorithm for most computers. A second algorithm is a vector version of Quicksort that takes advantage of the STAR's vector operations. The third algorithm is an adaptation of Batcher's (1968) sorting algorithm, which makes especially good use of vector operations but has a complexity of N(log N)-squared as compared with a complexity of N log N for the Quicksort algorithms. In spite of its worse complexity, Batcher's sorting algorithm is competitive with the serial version of Quicksort for vectors up to the largest that can be treated by STAR. Vector Quicksort outperforms the other two algorithms and is generally preferred. These results indicate that unusual instruction sets can introduce biases in program execution time that counter results predicted by worst-case asymptotic complexity analysis.

  13. Unsupervised spike sorting based on discriminative subspace learning.

    Science.gov (United States)

    Keshtkaran, Mohammad Reza; Yang, Zhi

    2014-01-01

    Spike sorting is a fundamental preprocessing step for many neuroscience studies which rely on the analysis of spike trains. In this paper, we present two unsupervised spike sorting algorithms based on discriminative subspace learning. The first algorithm simultaneously learns the discriminative feature subspace and performs clustering. It uses histogram of features in the most discriminative projection to detect the number of neurons. The second algorithm performs hierarchical divisive clustering that learns a discriminative 1-dimensional subspace for clustering in each level of the hierarchy until achieving almost unimodal distribution in the subspace. The algorithms are tested on synthetic and in-vivo data, and are compared against two widely used spike sorting methods. The comparative results demonstrate that our spike sorting methods can achieve substantially higher accuracy in lower dimensional feature space, and they are highly robust to noise. Moreover, they provide significantly better cluster separability in the learned subspace than in the subspace obtained by principal component analysis or wavelet transform.

  14. In-flight Sorting of BNNTs by Aspect Ratio

    Data.gov (United States)

    National Aeronautics and Space Administration — The key technical challenges are: (a) mechanical sorting is ineffective for nanoscale product, (b) BNNTs are non-conductive and the agglomeration tendency is strong,...

  15. Using Sorting Networks for Skill Building and Reasoning

    Science.gov (United States)

    Andre, Robert; Wiest, Lynda R.

    2007-01-01

    Sorting networks, used in graph theory, have instructional value as a skill- building tool as well as an interesting exploration in discrete mathematics. Students can practice mathematics facts and develop reasoning and logic skills with this topic. (Contains 4 figures.)

  16. Sorting and quantifying orbital angular momentum of laser beams

    CSIR Research Space (South Africa)

    Schulze, C

    2013-10-01

    Full Text Available We present a novel tool for sorting the orbital angular momentum and to determine the orbital angular momentum density of laser beams, which is based on the use of correlation filters....

  17. Embedded Active Fiber Optic Sensing Network for Structural Health Monitoring in Harsh Environments

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Anbo [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2016-09-30

    This report summarizes technical progress on the program “Embedded Active Fiber Optic Sensing Network for Structural Health Monitoring in Harsh Environments” funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed by the Center for Photonics Technology at Virginia Tech. The objective of this project is to develop a first-of-a-kind technology for remote fiber optic generation and detection of acoustic waves for structural health monitoring in harsh environments. During the project period, which is from April 1, 2013 to Septemeber 30, 2016, three different acoustic generation mechanisms were studied in detail for their applications in building a fiber optic acoustic generation unit (AGU), including laser induced plasma breakdown (LIP), Erbium-doped fiber laser absorption, and metal laser absorption. By comparing the performance of the AGUs designed based on these three mechanisms and analyzing the experimental results with simulations, the metal laser absorption method was selected to build a complete fiber optic structure health monitoring (FO-SHM) system for the proposed high temperature multi-parameter structure health monitoring application. Based on the simulation of elastic wave propagation and fiber Bragg grating acoustic pulse detection, an FO-SHM element together with a completed interrogation system were designed and built. This system was first tested on an aluminum piece in the low-temperature range and successfully demonstrated its capability of multi-parameter monitoring and multi-point sensing. In the later stages of the project, the research was focused on improving the surface attachment design and preparing the FO-SHM element for high temperature environment tests. After several upgrades to the surface attachment methods, the FO-SHM element was able to work reliably up to 600oC when attached to P91 pipes, which are the target material of this project. In the final stage of this project, this FO

  18. Spectral encoding method for measuring the relative arrival time between x-ray/optical pulses

    International Nuclear Information System (INIS)

    Bionta, M. R.; Hartmann, N.; Weaver, M.; French, D.; Glownia, J. M.; Bostedt, C.; Chollet, M.; Ding, Y.; Fritz, D. M.; Fry, A. R.; Krzywinski, J.; Lemke, H. T.; Messerschmidt, M.; Schorb, S.; Zhu, D.; White, W. E.; Nicholson, D. J.; Cryan, J. P.; Baker, K.; Kane, D. J.

    2014-01-01

    The advent of few femtosecond x-ray light sources brings promise of x-ray/optical pump-probe experiments that can measure chemical and structural changes in the 10–100 fs time regime. Widely distributed timing systems used at x-ray Free-Electron Laser facilities are typically limited to above 50 fs fwhm jitter in active x-ray/optical synchronization. The approach of single-shot timing measurements is used to sort results in the event processing stage. This has seen wide use to accommodate the insufficient precision of active stabilization schemes. In this article, we review the current technique for “measure-and-sort” at the Linac Coherent Light Source at the SLAC National Accelerator Laboratory. The relative arrival time between an x-ray pulse and an optical pulse is measured near the experimental interaction region as a spectrally encoded cross-correlation signal. The cross-correlation provides a time-stamp for filter-and-sort algorithms used for real-time sorting. Sub-10 fs rms resolution is common in this technique, placing timing precision at the same scale as the duration of the shortest achievable x-ray pulses

  19. Electrically and magnetically controlled optical spanner based on the transfer of spin angular momentum of light in an optically active medium

    International Nuclear Information System (INIS)

    Chen Lixiang; Zheng Guoliang; She Weilong

    2007-01-01

    An optical spanner is a light beam that can exert a torque on an object. It is demonstrated in this Rapid Communication that, with the aid of applied electric and magnetic fields, a light beam with initially linear polarization and initially zero total spin angular momentum can interact with an optically active medium, resulting in a change of the ratio of left-handed circularly polarized photons to right-handed ones. Thus the total spin angular momentum of the light is changed, which leads to a torque, creating an electrically and magnetically controlled optical spanner on the medium. For a linearly polarized 632.8 nm laser beam incident on a 100-μm-long Ce:Bi 12 TiO 20 whisker crystal with 5 μm radius, if the magnetic field is fixed at -1.8 T, both the left- (right-)handed circularly polarized photon number and the total spin angular momentum vary with the applied electric field in a sinusoidal way, which means the torque exerted by the optical spanner on the crystal also varies sinusoidally with the electric field. It is found that at 50 (or-50) kV/cm, 56% right- (left-)handed circularly polarized photons are translated into left- (right-)handed ones, which corresponds to a transfer of 0.56(ℎ/2π) spin angular momentum contributed by each photon

  20. The Sort on Radioactive Waste Type model: A method to sort single-shell tanks into characteristic groups. Revision 1

    International Nuclear Information System (INIS)

    Hill, J.G.; Simpson, B.C.

    1994-08-01

    The Sort on Radioactive Waste Type (SORWT) model presents a method to categorize Hanford Site single-shell tanks (SSTs) into groups of tanks expected to exhibit similar chemical and physical characteristics based on their major waste types and processing histories. This model has identified 29 different waste-type groups encompassing 135 of the 149 SSTs and 93% of the total waste volume in SSTs. The remaining 14 SSTs and associated wastes could not be grouped according to the established criteria and were placed in an ungrouped category. This letter report will detail the assumptions and methodologies used to develop the SORWT model and present the grouping results. Included with this report is a brief description and approximate compositions of the single-shell tank waste types. In the near future, the validity of the predicted groups will be statistically tested using analysis of variance of characterization data obtained from recent (post-1989) core sampling and analysis activities. In addition, the SORWT model will be used to project the nominal waste characteristics of entire waste type groups that have some recent characterization data available. These subsequent activities will be documented along with these initial results in a comprehensive, formal PNL report cleared for public release by September 1994