Health Instruction Packages: Specific Nursing Skills.

ERIC Educational Resources Information Center

Bates, Clarice; And Others

Text, illustrations, and exercises are utilized in a set of five learning modules designed to instruct nursing students in a variety of clinical skills. The first module, "Down the Tube: Insertion of a Nasogastric Tube" by Clarice Bates, describes materials and procedures used to insert a nasogastric tube through the nose and esophagus…

Hadfield prepares to insert biological samples in the MELFI-1

NASA Image and Video Library

2013-01-07

View of Canadian Space Agency (CSA) Chris Hadfield,Expedition 34 Flight Engineer (FE),preparing to insert biological samples in the Minus Eighty Laboratory Freezer for International Space Station (ISS) - (MELFI-1),in the Japanese Experiment Module (JEM) Pressurized Module (JPM). Photo was taken during Expedition 34.

Optical modulation in silicon-vanadium dioxide photonic structures

NASA Astrophysics Data System (ADS)

Miller, Kevin J.; Hallman, Kent A.; Haglund, Richard F.; Weiss, Sharon M.

2017-08-01

All-optical modulators are likely to play an important role in future chip-scale information processing systems. In this work, through simulations, we investigate the potential of a recently reported vanadium dioxide (VO2) embedded silicon waveguide structure for ultrafast all-optical signal modulation. With a VO2 length of only 200 nm, finite-differencetime- domain simulations suggest broadband (200 nm) operation with a modulation greater than 12 dB and an insertion loss of less than 3 dB. Predicted performance metrics, including modulation speed, modulation depth, optical bandwidth, insertion loss, device footprint, and energy consumption of the proposed Si-VO2 all-optical modulator are benchmarked against those of current state-of-the-art all-optical modulators with in-plane optical excitation.

NASA/First Materials Science Research Rack (MSRR-1) Module Inserts Development for the International Space Station

NASA Technical Reports Server (NTRS)

Crouch, Myscha; Carswell, Bill; Farmer, Jeff; Rose, Fred; Tidwell, Paul

1999-01-01

The Material Science Research Rack 1 (MSRR-1) of the Material Science Research Facility (MSRF) contains an Experiment Module (EM) being developed collaboratively by NASA and the European Space Agency (ESA). This NASA/ESA EM will accommodate several different removable and replaceable Module Inserts (MIs) which are installed on orbit. Two of the NASA MIs being developed for specific material science investigations are described herein.

Materials Science Research Rack-1 (MSRR-1)

NASA Technical Reports Server (NTRS)

2001-01-01

This computer-generated image depicts the Materials Science Research Rack-1 (MSRR-1) being developed by NASA's Marshall Space Flight Center and the European Space Agency (ESA) for placement in the Destiny laboratory module aboard the International Space Station. The rack is part of the plarned Materials Science Research Facility (MSRF) and is expected to include two furnace module inserts, a Quench Module Insert (being developed by NASA's Marshall Space Flight Center) to study directional solidification in rapidly cooled alloys and a Diffusion Module Insert (being developed by the European Space Agency) to study crystal growth, and a transparent furnace (being developed by NASA's Space Product Development program). Multi-user equipment in the rack is being developed under the auspices of NASA's Office of Biological and Physical Research (OBPR) and ESA. Key elements are labeled in other images (0101754, 0101829, 0101830, and TBD).

Materials Science Research Rack-1 (MSRR-1)

NASA Technical Reports Server (NTRS)

2001-01-01

This computer-generated image depicts the Materials Science Research Rack-1 (MSRR-1) being developed by NASA's Marshall Space Flight Center and the European Space Agency (ESA) for placement in the Destiny laboratory module aboard the International Space Station. The rack is part of the plarned Materials Science Research Facility (MSRF) and is expected to include two furnace module inserts, a Quench Module Insert (being developed by NASA's Marshall Space Flight Center) to study directional solidification in rapidly cooled alloys and a Diffusion Module Insert (being developed by the European Space Agency) to study crystal growth, and a transparent furnace (being developed by NASA's Space Product Development program). Multi-user equipment in the rack is being developed under the auspices of NASA's Office of Biological and Physical Research (OBPR) and ESA. A larger image is available without labels (No. 0101755).

Materials Science Research Rack-1 (MSRR-1)

NASA Technical Reports Server (NTRS)

2001-01-01

This computer-generated image depicts the Materials Science Research Rack-1 (MSRR-1) being developed by NASA's Marshall Space Flight Center and the European Space Agency (ESA) for placement in the Destiny laboratory module aboard the International Space Station. The rack is part of the plarned Materials Science Research Facility (MSRF) and is expected to include two furnace module inserts, a Quench Module Insert (being developed by NASA's Marshall Space Flight Center) to study directional solidification in rapidly cooled alloys and a Diffusion Module Insert (being developed by the European Space Agency) to study crystal growth, and a transparent furnace (being developed by NASA's Space Product Development program). Multi-user equipment in the rack is being developed under the auspices of NASA's Office of Biological and Physical Research (OBPR) and ESA. Key elements are labeled in other images (0101754, 0101830, and TBD).

Materials Science Research Rack-1 (MSRR-1)

NASA Technical Reports Server (NTRS)

2001-01-01

This scale model depicts the Materials Science Research Rack-1 (MSRR-1) being developed by NASA's Marshall Space Flight Center and the European Space Agency (ESA) for placement in the Destiny laboratory module aboard the International Space Station. The rack is part of the plarned Materials Science Research Facility (MSRF) and is expected to include two furnace module inserts, a Quench Module Insert (being developed by NASA's Marshall Space Flight Center) to study directional solidification in rapidly cooled alloys and a Diffusion Module Insert (being developed by the European Space Agency) to study crystal growth, and a transparent furnace (being developed by NASA's Space Product Development program). Multi-user equipment in the rack is being developed under the auspices of NASA's Office of Biological and Physical Research (OBPR) and ESA. Key elements are labeled in other images (0101754, 0101829, 0101830, and TBD).

Materials Science Research Rack-1 (MSRR-1)

NASA Technical Reports Server (NTRS)

2001-01-01

This computer-generated image depicts the Materials Science Research Rack-1 (MSRR-1) being developed by NASA's Marshall Space Flight Center and the European Space Agency (ESA) for placement in the Destiny laboratory module aboard the International Space Station. The rack is part of the plarned Materials Science Research Facility (MSRF) and is expected to include two furnace module inserts, a Quench Module Insert (being developed by NASA's Marshall Space Flight Center) to study directional solidification in rapidly cooled alloys and a Diffusion Module Insert (being developed by the European Space Agency) to study crystal growth, and a transparent furnace (being developed by NASA's Space Product Development program). Multi-user equipment in the rack is being developed under the auspices of NASA's Office of Biological and Physical Research (OBPR) and ESA. Key elements are labeled in other images (0101754, 0101829, 0101830).

Microgravity

NASA Image and Video Library

2001-06-05

This scale model depicts the Materials Science Research Rack-1 (MSRR-1) being developed by NASA's Marshall Space Flight Center and the European Space Agency (ESA) for placement in the Destiny laboratory module aboard the International Space Station. The rack is part of the plarned Materials Science Research Facility (MSRF) and is expected to include two furnace module inserts, a Quench Module Insert (being developed by NASA's Marshall Space Flight Center) to study directional solidification in rapidly cooled alloys and a Diffusion Module Insert (being developed by the European Space Agency) to study crystal growth, and a transparent furnace (being developed by NASA's Space Product Development program). Multi-user equipment in the rack is being developed under the auspices of NASA's Office of Biological and Physical Research (OBPR) and ESA. Here the transparent furnace is extracted for servicing. Key elements are labeled in other images (0101754, 0101829, 0101830, and TBD).

Phenotypic modulation of auto-reactive cells by insertion of tolerogenic molecules via MSC-derived exosomes.

PubMed

Mokarizadeh, Aram; Delirezh, Nowruz; Morshedi, Ahhmad; Mosayebi, Ghasem; Farshid, Amir-Abbas; Dalir-Naghadeh, Bahram

2012-01-01

Auto-reactive cells-mediated immune responses are responsible for the current tissue damages during autoimmunity. Accordingly, functional modulation of auto-reactive cells has been a pivotal aim in many of recent studies. In the current study, we investigated the possibility for insertion of regulatory molecules onto auto-reactive cells through exosomal nano-shuttles as a novel approach for phenotype modification of auto-reactive cells. The exosomes were isolated from supernatant of mesenchymal stem cells culture. Resultant exosomes co-cultured with lymphocytes were harvested from established EAE mice in the presence of antigenic MOG35-55 peptide. After 24 hr, insertion of exosomal tolerogenic molecules (PD-L1, TGF-β, galectin-1) onto auto-reactive cells were explored through flow cytometry. The potency of exosomal inserted membrane molecules to modulate phenotype of auto-reactive lymphocytes was assessed upon ELISA test for their-derived cytokines IFN-γ and IL-17. Incorporation of exosomal molecules into lymohocytes' membrane was confirmed by flow cytometric analyses for surface levels of mentioned molecules. Additionally, the decreased secretion of IFN-γ and IL-17 were detected in exosome pre-treated lymphocytes upon stimulation with MOG peptide. Mesenchymal stem cells -derived exosomes showed to be efficient organelles for insertion of bioactive tolerogenic molecules onto auto-reactive cells and modulation of their phenotypes.

First Materials Science Research Facility Rack Capabilities and Design Features

NASA Technical Reports Server (NTRS)

Cobb, S.; Higgins, D.; Kitchens, L.; Curreri, Peter (Technical Monitor)

2002-01-01

The first Materials Science Research Rack (MSRR-1) is the primary facility for U.S. sponsored materials science research on the International Space Station. MSRR-1 is contained in an International Standard Payload Rack (ISPR) equipped with the Active Rack Isolation System (ARIS) for the best possible microgravity environment. MSRR-1 will accommodate dual Experiment Modules and provide simultaneous on-orbit processing operations capability. The first Experiment Module for the MSRR-1, the Materials Science Laboratory (MSL), is an international cooperative activity between NASA's Marshall Space Flight Center (MSFC) and the European Space Agency's (ESA) European Space Research and Technology Center (ESTEC). The MSL Experiment Module will accommodate several on-orbit exchangeable experiment-specific Module Inserts which provide distinct thermal processing capabilities. Module Inserts currently planned for the MSL are a Quench Module Insert, Low Gradient Furnace, and a Solidification with Quench Furnace. The second Experiment Module for the MSRR-1 configuration is a commercial device supplied by MSFC's Space Products Development (SPD) Group. Transparent furnace assemblies include capabilities for vapor transport processes and annealing of glass fiber preforms. This Experiment Module is replaceable on-orbit. This paper will describe facility capabilities, schedule to flight and research opportunities.

Mediators of sexual functioning and marital quality in chronically depressed adults with and without a history of childhood sexual abuse.

PubMed

Dunlop, Boadie W; Hill, Eric; Johnson, Benjamin N; Klein, Daniel N; Gelenberg, Alan J; Rothbaum, Barbara O; Thase, Michael E; Kocsis, James H

2015-03-01

Sexual dysfunction is common among depressed adults. Childhood sexual abuse (CSA) and depressive symptomology are among the risk factors for sexual dysfunction, and these factors may interact to predict adult relationship functioning. Several models have been developed postulating interactions between these variables. We tested models of the effects of CSA and elucidate the associations between CSA, sexual dysfunction, depression severity, anxiety, and relationship quality in chronically depressed adults. Baseline data from 808 chronically depressed outpatients enrolled in the Research Evaluating the Value of Augmenting Medication with Psychotherapy study were evaluated using structural equation modeling. The Inventory of Depressive Symptomology, self-report version (IDS-SR) assessed depression severity, and the Mood and Anxiety Symptom Questionnaire Anxious Arousal subscale assessed anxiety. Sexual function was assessed with the Arizona Sexual Experiences Scale (ASEX), and the Quality of Marriage Index (QMI) assessed relationship quality for patients in stable relationships. CSA scores predicted depression severity on the IDS-SR, as well as lower relationship quality and sexual satisfaction. ASEX scores were significantly associated with depression severity but were not correlated with the QMI. Two models were evaluated to elucidate these associations, revealing that (i) depression severity and anxious arousal mediated the relationship between CSA and adult sexual function, (ii) anxious arousal and sexual functioning mediated the association between CSA and depression symptoms, and (iii) when these models were combined, anxious arousal emerged as the most important mediator of CSA on depression which, in turn, mediated associations with adult sexual satisfaction and relationship quality. Although CSA predicts lower relationship and sexual satisfaction among depressed adults, the long-term effects of CSA appear to be mediated by depressive and anxious symptoms. It is important to address depression and anxiety symptoms when treating patients with CSA who present with sexual dysfunction or marital concerns. © 2014 International Society for Sexual Medicine.

Materials Science Research Rack-1 (MSRR-1)

NASA Technical Reports Server (NTRS)

2001-01-01

This scale model depicts the Materials Science Research Rack-1 (MSRR-1) being developed by NASA's Marshall Space Flight Center and the European Space Agency (ESA) for placement in the Destiny laboratory module aboard the International Space Station. The rack is part of the plarned Materials Science Research Facility (MSRF) and is expected to include two furnace module inserts, a Quench Module Insert (being developed by NASA's Marshall Space Flight Center) to study directional solidification in rapidly cooled alloys and a Diffusion Module Insert (being developed by the European Space Agency) to study crystal growth, and a transparent furnace (being developed by NASA's Space Product Development program). Multi-user equipment in the rack is being developed under the auspices of NASA's Office of Biological and Physical Research (OBPR) and ESA. Key elements are labeled in other images (0101754, 0101829, 0101830, and TBD). This image is from a digital still camera; higher resolution is not available.

Microgravity

NASA Image and Video Library

2001-06-05

This scale model depicts the Materials Science Research Rack-1 (MSRR-1) being developed by NASA's Marshall Space Flight Center and the European Space Agency (ESA) for placement in the Destiny laboratory module aboard the International Space Station. The rack is part of the plarned Materials Science Research Facility (MSRF) and is expected to include two furnace module inserts, a Quench Module Insert (being developed by NASA's Marshall Space Flight Center) to study directional solidification in rapidly cooled alloys and a Diffusion Module Insert (being developed by the European Space Agency) to study crystal growth, and a transparent furnace (being developed by NASA's Space Product Development program). Multi-user equipment in the rack is being developed under the auspices of NASA's Office of Biological and Physical Research (OBPR) and ESA. Key elements are labeled in other images (0101754, 0101829, and TBD). This composite is from a digital still camera; higher resolution is not available.

Materials Science Research Rack-1 (MSRR-1)

NASA Technical Reports Server (NTRS)

2001-01-01

This scale model depicts the Materials Science Research Rack-1 (MSRR-1) being developed by NASA's Marshall Space Flight Center and the European Space Agency (ESA) for placement in the Destiny laboratory module aboard the International Space Station. The rack is part of the plarned Materials Science Research Facility (MSRF) and is expected to include two furnace module inserts, a Quench Module Insert (being developed by NASA's Marshall Space Flight Center) to study directional solidification in rapidly cooled alloys and a Diffusion Module Insert (being developed by the European Space Agency) to study crystal growth, and a transparent furnace (being developed by NASA's Space Product Development program). Multi-user equipment in the rack is being developed under the auspices of NASA's Office of Biological and Physical Research (OBPR) and ESA. Here the transparent furnace is extracted for servicing. Key elements are labeled in other images (0101754, 0101829, 0101830, and TBD).

Microgravity

NASA Image and Video Library

2001-06-05

This scale model depicts the Materials Science Research Rack-1 (MSRR-1) being developed by NASA's Marshall Space Flight Center and the European Space Agency (ESA) for placement in the Destiny laboratory module aboard the International Space Station. The rack is part of the plarned Materials Science Research Facility (MSRF) and is expected to include two furnace module inserts, a Quench Module Insert (being developed by NASA's Marshall Space Flight Center) to study directional solidification in rapidly cooled alloys and a Diffusion Module Insert (being developed by the European Space Agency) to study crystal growth, and a transparent furnace (being developed by NASA's Space Product Development program). Multi-user equipment in the rack is being developed under the auspices of NASA's Office of Biological and Physical Research (OBPR) and ESA. Key elements are labeled in other images (0101754, 0101829, 0101830, and TBD). This image is from a digital still camera; higher resolution is not available.

Materials Science Research Rack-1 (MSRR-1)

NASA Technical Reports Server (NTRS)

2001-01-01

This scale model depicts the Materials Science Research Rack-1 (MSRR-1) being developed by NASA's Marshall Space Flight Center and the European Space Agency (ESA) for placement in the Destiny laboratory module aboard the International Space Station. The rack is part of the plarned Materials Science Research Facility (MSRF) and is expected to include two furnace module inserts, a Quench Module Insert (being developed by NASA's Marshall Space Flight Center) to study directional solidification in rapidly cooled alloys and a Diffusion Module Insert (being developed by the European Space Agency) to study crystal growth, and a transparent furnace (being developed by NASA's Space Product Development program). Multi-user equipment in the rack is being developed under the auspices of NASA's Office of Biological and Physical Research (OBPR) and ESA. Key elements are labeled in other images (0101754, 0101829, and TBD). This composite is from a digital still camera; higher resolution is not available.

Using Comprehensive Video-Module Instruction as an Alternative Approach for Teaching IUD Insertion.

PubMed

Garcia-Rodriguez, Juan Antonio; Donnon, Tyrone

2016-01-01

Family medicine clinicians and residents have increasing educational and work demands that have made it difficult to provide and access training on specific procedures such as IUD insertion. The purpose of this study was to determine whether the use of video-module instruction could provide residents with the necessary knowledge and skills to perform an IUD insertion correctly when compared with the traditional form of instruction, which is a lecture-demonstration session provided by an academic gynecologist. Thirty-nine family medicine residents participated in the study during the induction period at the beginning of their residency program in July 2012 at the University of Calgary. A randomized, two group pretest/posttest experimental research design was used to compare the procedural knowledge and skills performance (posttest only) of residents trained using an alternative instructional intervention (video-module teaching) with the traditional lecture-demonstration approach to teaching IUD insertion. Both teaching methods were effective in providing procedural knowledge instruction, and the paired-samples t tests results were almost identical: t (37)=1.35. On the other hand, performance scores were significantly higher in the video-module group: t (37)=2.37, 95% CI (0.61, 8.00), with a mean difference in performance of 4.31. There were no significant differences in residents' satisfaction scores, and there was no correlation between the different scores and sex or age or between performance and level of satisfaction. This video-module instruction is an effective method to provide comprehensive IUD insertion training, and the psychomotor skills gain (performance component) was significantly higher than the traditional method of instruction.

A multimodality imaging-compatible insertion robot with a respiratory motion calibration module designed for ablation of liver tumors: a preclinical study.

PubMed

Li, Dongrui; Cheng, Zhigang; Chen, Gang; Liu, Fangyi; Wu, Wenbo; Yu, Jie; Gu, Ying; Liu, Fengyong; Ren, Chao; Liang, Ping

2018-04-03

To test the accuracy and efficacy of the multimodality imaging-compatible insertion robot with a respiratory motion calibration module designed for ablation of liver tumors in phantom and animal models. To evaluate and compare the influences of intervention experience on robot-assisted and ultrasound-controlled ablation procedures. Accuracy tests on rigid body/phantom model with a respiratory movement simulation device and microwave ablation tests on porcine liver tumor/rabbit liver cancer were performed with the robot we designed or with the traditional ultrasound-guidance by physicians with or without intervention experience. In the accuracy tests performed by the physicians without intervention experience, the insertion accuracy and efficiency of robot-assisted group was higher than those of ultrasound-guided group with statistically significant differences. In the microwave ablation tests performed by the physicians without intervention experience, better complete ablation rate was achieved when applying the robot. In the microwave ablation tests performed by the physicians with intervention experience, there was no statistically significant difference of the insertion number and total ablation time between the robot-assisted group and the ultrasound-controlled group. The evaluation by the NASA-TLX suggested that the robot-assisted insertion and microwave ablation process performed by physicians with or without experience were more comfortable. The multimodality imaging-compatible insertion robot with a respiratory motion calibration module designed for ablation of liver tumors could increase the insertion accuracy and ablation efficacy, and minimize the influence of the physicians' experience. The ablation procedure could be more comfortable with less stress with the application of the robot.

Design of Multi-core Fiber Patch Panel for Space Division Multiplexing Implementations

NASA Astrophysics Data System (ADS)

González, Luz E.; Morales, Alvaro; Rommel, Simon; Jørgensen, Bo F.; Porras-Montenegro, N.; Tafur Monroy, Idelfonso

2018-03-01

A multi-core fiber (MCF) patch panel was designed, allowing easy coupling of individual signals to and from a 7-core MCF. The device was characterized, measuring insertion loss and cross talk, finding highest insertion loss and lowest crosstalk at 1300 nm with values of 9.7 dB and -36.5 dB respectively, while at 1600 nm insertion loss drops to 4.8 dB and crosstalk increases to -24.1 dB. Two MCF splices between the fan-in module, the MCF, and the fan-out module are included in the characterization, and splicing parameters are discussed.

Rack Insertion End Effector (RIEE) guidance

NASA Technical Reports Server (NTRS)

Malladi, Narasimha S.

1994-01-01

NASA-KSC has developed a mechanism to handle and insert Racks into the Space Station Logistic Modules. This mechanism consists of a Base with 3 motorized degrees of freedom, a 3 section motorized Boom that goes from 15 to 44 feet in length, and a Rack Insertion End Effector (RIEE) with 5 hand wheels for precise alignment. During the 1993 NASA-ASEE Summer Faculty Fellowship Program at KSC, I designed an Active Vision (Camera) Arrangement and developed an algorithm to determine (1) the displacements required by the Room for its initial positioning and (2) the rotations required at the five hand-wheels of the RIEE, for the insertion of the Rack, using the centroids fo the Camera Images of the Location Targets in the Logistic Module. Presently, during the summer of '94, I completed the preliminary design of an easily portable measuring instrument using encoders to obtain the 3-Dimensional Coordinates of Location Targets in the Logistics Module relative to the RIEE mechanism frame. The algorithm developed in '93 can use the output of this instrument also. Simplification of the '93 work and suggestions for the future work are discussed.

Atomic force microscopy captures length phenotypes in single proteins

PubMed Central

Carrion-Vazquez, Mariano; Marszalek, Piotr E.; Oberhauser, Andres F.; Fernandez, Julio M.

1999-01-01

We use single-protein atomic force microscopy techniques to detect length phenotypes in an Ig module. To gain amino acid resolution, we amplify the mechanical features of a single module by engineering polyproteins composed of up to 12 identical repeats. We show that on mechanical unfolding, mutant polyproteins containing five extra glycine residues added to the folded core of the module extend 20 Å per module farther than the wild-type polyproteins. By contrast, similar insertions near the N or C termini have no effect. Hence, our atomic force microscopy measurements readily discriminate the location of the insert and measure its size with a resolution similar to that of NMR and x-ray crystallography. PMID:10500169

Experimental evaluation of neural probe’s insertion induced injury based on digital image correlation method

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

Zhang, Wenguang, E-mail: zhwg@sjtu.edu.cn; Ma, Yakun; Li, Zhengwei

Purpose: The application of neural probes in clinic has been challenged by probes’ short lifetime when implanted into brain tissue. The primary goal is to develop an evaluation system for testing brain tissue injury induced by neural probe’s insertion using microscope based digital image correlation method. Methods: A brain tissue phantom made of silicone rubber with speckle pattern on its surface was fabricated. To obtain the optimal speckle pattern, mean intensity gradient parameter was used for quality assessment. The designed testing system consists of three modules: (a) load module for simulating neural electrode implantation process; (b) data acquisition module tomore » capture micrographs of speckle pattern and to obtain reactive forces during the insertion of the probe; (c) postprocessing module for extracting tissue deformation information from the captured speckle patterns. On the basis of the evaluation system, the effects of probe wedge angle, insertion speed, and probe streamline on insertion induced tissue injury were investigated. Results: The optimal quality speckle pattern can be attained by the following fabrication parameters: spin coating rate—1000 r/min, silicone rubber component A: silicone rubber component B: softener: graphite = 5 ml: 5 ml: 2 ml: 0.6 g. The probe wedge angle has a significant effect on tissue injury. Compared to wedge angle 40° and 20°, maximum principal strain of 60° wedge angle was increased by 40.3% and 87.5%, respectively; compared with a relatively higher speed (500 μm/s), the maximum principle strain within the tissue induced by slow insertion speed (100 μm/s) was increased by 14.3%; insertion force required by probe with convex streamline was smaller than the force of traditional probe. Based on the experimental results, a novel neural probe that has a rounded tip covered by a biodegradable silk protein coating with convex streamline was proposed, which has both lower insertion and micromotion induced tissue injury. Conclusions: The established evaluation system has provided a simulation environment for testing brain tissue injury produced by various insertion conditions. At the same time, it eliminates the adverse effect of biological factors on tissue deformation during the experiment, improving the repeatability of measurement results. As a result, the evaluation system will provide support on novel neural probe design that can reduce the acute tissue injury during the implantation of the probe.« less

Method and apparatus for assembling solid oxide fuel cells

DOEpatents

Szreders, Bernard E.; Campanella, Nicholas

1989-01-01

A plurality of jet air tubes are supported and maintained in a spaced matrix array by a positioning/insertion assembly for insertion in respective tubes of a solid oxide fuel cell (SOFC) in the assembly of an SOFC module. The positioning/insertion assembly includes a plurality of generally planar, elongated, linear vanes which are pivotally mounted at each end thereof to a support frame. The vanes, which each include a plurality of spaced slots along the facing edges thereof, may be pivotally displaced from a generally vertical orientation, wherein each jet air tube is positioned within and engaged by the aligned slots of a plurality of paired upper and lower vanes to facilitate their insertion in respective aligned SOFC tubes arranged in a matrix array, to an inclined orientation, wherein the jet air tubes may be removed from the positioning/insertion assembly after being inserted in the SOFC tubes. A rectangular compression assembly of adjustable size is adapted to receive and squeeze a matrix of SOFC tubes so as to compress the inter-tube nickel felt conductive pads which provide series/parallel electrical connection between adjacent SOFCs, with a series of increasingly larger retainer frames used to maintain larger matrices of SOFC tubes in position. Expansion of the SOFC module housing at the high operating temperatures of the SOFC is accommodated by conductive, flexible, resilient expansion, connector bars which provide support and electrical coupling at the top and bottom of the SOFC module housing.

Cryogenic test of the 4 K / 2 K insert for the ARIEL e-Linac cryomodule

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

Laxdal, R. E.; Ma, Y.; Harmer, P.

2014-01-29

The ARIEL project at TRIUMF requires a 50 MeV superconducting electron linac consisting of five nine cell 1.3 GHz cavities divided into three cryomodules with one, two and two cavities in each module respectively. LHe is distributed in parallel to each module at 4 K and at ∼1.2 bar. Each module has a cryogenic insert on board that receives the 4 K liquid and produces 2 K into a cavity phase separator. The module combines a 4 K phase separator, a plate and fin heat exchanger from DATE and a J-T valve expanding into the 2 K phase separator. Themore » unit also supplies 4 K liquid to thermal intercepts in the module in siphon loops that return the vaporized liquid to the 4 K reservoir. For testing purposes the unit is outfitted with a dummy 2 K phase separator and thermal intercepts with variable heaters that mimic the final heat loads in order to test the cryogenic performance. The design of the 4 K / 2 K insert, the results of the cold tests and a summary of the test infrastructure including cryogenics services will be presented.« less

Method and apparatus for assembling solid oxide fuel cells

DOEpatents

Szreders, B.E.; Campanella, N.

1988-05-11

This invention relates generally to solid oxide fuel power generators and is particularly directed to improvements in the assembly and coupling of solid oxide fuel cell modules. A plurality of jet air tubes are supported and maintained in a spaced matrix array by a positioning/insertion assembly for insertion in respective tubes of a solid oxide fuel cell (SOFC) in the assembly of an SOFC module. The positioning/insertion assembly includes a plurality of generally planar, elongated, linear vanes which are pivotally mounted at each end thereof to a support frame. A rectangular compression assembly of adjustable size is adapted to receive and squeeze a matrix of SOFC tubes so as to compress the inter-tube nickel felt conductive pads which provide series/parallel electrical connection between adjacent SOFCs, with a series of increasingly larger retainer frames used to maintain larger matrices of SOFC tubes in position. Expansion of the SOFC module housing at the high operating temperatures of the SOFC is accommodated by conductive, flexible, resilient expansion, connector bars which provide support and electrical coupling at the top and bottom of the SOFC module housing. 17 figs.

Rack Insertion End Effector (RIEE) automation

NASA Technical Reports Server (NTRS)

Malladi, Narasimha

1993-01-01

NASA is developing a mechanism to manipulate and insert Racks into the Space Station Logistic modules. The mechanism consists of the following: a base with three motorized degrees of freedom, a 3 section motorized boom that goes from 15 to 44 feet in length, and a Rack Insertion End Effector (RIEE) with 5 hand wheels for precise alignment. The robotics section was tasked with the automation of the RIEE unit. In this report, for the automation of the RIEE unit, application of the Perceptics Vision System was conceptually developed to determine the position and orientation of the RIEE relative to the logistic module, and a MathCad program is written to display the needed displacements for precise alignment and final insertion of the Rack. The uniqueness of this report is that the whole report is in fact a MathCad program including text, derivations, and executable equations with example inputs and outputs.

Terahertz modulation based on surface plasmon resonance by self-gated graphene

NASA Astrophysics Data System (ADS)

Qian, Zhenhai; Yang, Dongxiao; Wang, Wei

2018-05-01

We theoretically and numerically investigate the extraordinary optical transmission through a terahertz metamaterial composed of metallic ring aperture arrays. The physical mechanism of different transmission peaks is elucidated to be magnetic polaritons or propagation surface plasmons with the help of surface current and electromagnetic field distributions at respective resonance frequencies. Then, we propose a high performance terahertz modulator based on the unique PSP resonance and combined with the metallic ring aperture arrays and a self-gated parallel-plate graphene capacitor. Because, to date, few researches have exhibited gate-controlled graphene modulation in terahertz region with low insertion losses, high modulation depth and low control voltage at room temperature. Here, we propose a 96% amplitude modulation with 0.7 dB insertion losses and ∼5.5 V gate voltage. Besides, we further study the absorption spectra of the modulator. When the transmission of modulator is very low, a 91% absorption can be achieved for avoiding damaging the source devices.

Family of pH-Low-Insertion-Peptides (pHLIPs)

NASA Astrophysics Data System (ADS)

Weerakkody, Dhammika; Moshnikova, Anna; Moshnikova, Valentina; Thakur, Mak; Rossi, Bethany; Engelman, Donald; Andreev, Oleg; Reshetnyak, Yana

2012-02-01

pHLIP (pH (Low) Insertion Peptide) is a novel delivery system for targeting of acidic diseased tissue such as solid tumors, sites of inflammation, arthritis and other pathological states. The molecular mechanism of pHLIP action is based on pH-dependent insertion and folding of pHLIP in membrane. We performed sequence variation and investigated 16 pHLIP variants with main goals of understanding the main principles of peptide-lipid interactions and tune delivery capability of pHLIP. The biophysical studies including thermodynamics and kinetics of the peptides interaction with a lipid bilayer of liposomes and cellular membranes were carried out. We found that peptides association to membrane at neutral and low pH could be modulated by 3-4 times. The apparent pK of transition from surface bound to membrane-inserted state could be tuned from 6.5 to 4.5. The rate of peptide's insertion across a bilayer could be enhanced 100 times compared to parent pHLIP. As a result, blood clearance and tumor targeting were modulated in a significant degree. The work is supported by NIH grants CA133890 to OAA, DME, YRK.

All optical coherent receiver for self-homodyne detection of digitally phase modulated optical signals

NASA Astrophysics Data System (ADS)

Kiasaleh, Kamran

1994-02-01

A novel optical phase-locked loop (OPLL) system for the self-homodyne detection of digitally phase modulated optical signals is introduced. A Mach-Zehnder type interferometer is used to self-homodyne binary phase-modulated optical signals with an external phase modulator inserted in the control arm of the interferometer.

Novel modes of RNA editing in mitochondria

PubMed Central

Moreira, Sandrine; Valach, Matus; Aoulad-Aissa, Mohamed; Otto, Christian; Burger, Gertraud

2016-01-01

Abstract Gene structure and expression in diplonemid mitochondria are unparalleled. Genes are fragmented in pieces (modules) that are separately transcribed, followed by the joining of module transcripts to contiguous RNAs. Some instances of unique uridine insertion RNA editing at module boundaries were noted, but the extent and potential occurrence of other editing types remained unknown. Comparative analysis of deep transcriptome and genome data from Diplonema papillatum mitochondria reveals ∼220 post-transcriptional insertions of uridines, but no insertions of other nucleotides nor deletions. In addition, we detect in total 114 substitutions of cytosine by uridine and adenosine by inosine, amassed into unusually compact clusters. Inosines in transcripts were confirmed experimentally. This is the first report of adenosine-to-inosine editing of mRNAs and ribosomal RNAs in mitochondria. In mRNAs, editing causes mostly amino-acid additions and non-synonymous substitutions; in ribosomal RNAs, it permits formation of canonical secondary structures. Two extensively edited transcripts were compared across four diplonemids. The pattern of uridine-insertion editing is strictly conserved, whereas substitution editing has diverged dramatically, but still rendering diplonemid proteins more similar to other eukaryotic orthologs. We posit that RNA editing not only compensates but also sustains, or even accelerates, ultra-rapid evolution of genome structure and sequence in diplonemid mitochondria. PMID:27001515

Design and analysis of a low-loss linear analog phase modulator for deep space spacecraft X-band transponder applications

NASA Technical Reports Server (NTRS)

Mysoor, N. R.; Mueller, R. O.

1991-01-01

This article summarizes the design concepts, analyses, and development of an X-band (8145 MHz) transponder low-loss linear phase modulator for deep space spacecraft applications. A single-section breadboard circulator-coupled reflection phase modulator has been analyzed, fabricated, and evaluated. A linear phase deviation of 92 deg with a linearity tolerance of +/- 8 percent was measured for this modulator from 8257 MHz to 8634 MHz over the temperature range -20 to 75 C. The measured insertion loss and the static delay variation with temperature were 2 +/- 0.3 dB and 0.16 psec/ C, respectively. Based on this design, cascaded sections have been modeled, and simulations were performed to provide an X-band deep space transponder (DST) phase modulator with +/- 2.5 radians (+/- 143 deg) of peak phase deviation to accommodate downlink signal modulation with composite telemetry data and ranging, with a deviation linearity tolerance of +/- 8 percent and insertion loss of less than 10 +/- 0.5 dB. A two-section phase modulator using constant gamma hyperabrupt varactors and an efficient modulator driver circuit was breadboarded. The measured results satisfy the DST phase-modulator requirements and show excellent agreement with the predicted results.

MR-compatibility of a high-resolution small animal PET insert operating inside a 7 T MRI.

PubMed

Thiessen, J D; Shams, E; Stortz, G; Schellenberg, G; Bishop, D; Khan, M S; Kozlowski, P; Retière, F; Sossi, V; Thompson, C J; Goertzen, A L

2016-11-21

A full-ring PET insert consisting of 16 PET detector modules was designed and constructed to fit within the 114 mm diameter gradient bore of a Bruker 7 T MRI. The individual detector modules contain two silicon photomultiplier (SiPM) arrays, dual-layer offset LYSO crystal arrays, and high-definition multimedia interface (HDMI) cables for both signal and power transmission. Several different RF shielding configurations were assessed prior to construction of a fully assembled PET insert using a combination of carbon fibre and copper foil for RF shielding. MR-compatibility measurements included field mapping of the static magnetic field (B 0 ) and the time-varying excitation field (B 1 ) as well as acquisitions with multiple pulse sequences: spin echo (SE), rapid imaging with refocused echoes (RARE), fast low angle shot (FLASH) gradient echo, and echo planar imaging (EPI). B 0 field maps revealed a small degradation in the mean homogeneity (+0.1 ppm) when the PET insert was installed and operating. No significant change was observed in the B 1 field maps or the image homogeneity of various MR images, with a 9% decrease in the signal-to-noise ratio (SNR) observed only in EPI images acquired with the PET insert installed and operating. PET detector flood histograms, photopeak amplitudes, and energy resolutions were unchanged in individual PET detector modules when acquired during MRI operation. There was a small baseline shift on the PET detector signals due to the switching amplifiers used to power MRI gradient pulses. This baseline shift was observable when measured with an oscilloscope and varied as a function of the gradient duty cycle, but had no noticeable effect on the performance of the PET detector modules. Compact front-end electronics and effective RF shielding led to minimal cross-interference between the PET and MRI systems. Both PET detector and MRI performance was excellent, whether operating as a standalone system or a hybrid PET/MRI.

MR-compatibility of a high-resolution small animal PET insert operating inside a 7 T MRI

NASA Astrophysics Data System (ADS)

Thiessen, J. D.; Shams, E.; Stortz, G.; Schellenberg, G.; Bishop, D.; Khan, M. S.; Kozlowski, P.; Retière, F.; Sossi, V.; Thompson, C. J.; Goertzen, A. L.

2016-11-01

A full-ring PET insert consisting of 16 PET detector modules was designed and constructed to fit within the 114 mm diameter gradient bore of a Bruker 7 T MRI. The individual detector modules contain two silicon photomultiplier (SiPM) arrays, dual-layer offset LYSO crystal arrays, and high-definition multimedia interface (HDMI) cables for both signal and power transmission. Several different RF shielding configurations were assessed prior to construction of a fully assembled PET insert using a combination of carbon fibre and copper foil for RF shielding. MR-compatibility measurements included field mapping of the static magnetic field (B 0) and the time-varying excitation field (B 1) as well as acquisitions with multiple pulse sequences: spin echo (SE), rapid imaging with refocused echoes (RARE), fast low angle shot (FLASH) gradient echo, and echo planar imaging (EPI). B 0 field maps revealed a small degradation in the mean homogeneity (+0.1 ppm) when the PET insert was installed and operating. No significant change was observed in the B 1 field maps or the image homogeneity of various MR images, with a 9% decrease in the signal-to-noise ratio (SNR) observed only in EPI images acquired with the PET insert installed and operating. PET detector flood histograms, photopeak amplitudes, and energy resolutions were unchanged in individual PET detector modules when acquired during MRI operation. There was a small baseline shift on the PET detector signals due to the switching amplifiers used to power MRI gradient pulses. This baseline shift was observable when measured with an oscilloscope and varied as a function of the gradient duty cycle, but had no noticeable effect on the performance of the PET detector modules. Compact front-end electronics and effective RF shielding led to minimal cross-interference between the PET and MRI systems. Both PET detector and MRI performance was excellent, whether operating as a standalone system or a hybrid PET/MRI.

Validation of an Acoustic Head Simulator for the Evaluation of Personal Hearing Protection Devices

DTIC Science & Technology

2004-11-01

et recouvert de peau artificielle. Les cavités de chaque côté permettent l’insertion de modules d’oreilles qui reproduisent les mécanismes des ...aux spécifications publiées. Ces différences n’ont pas influé sur la perte d’insertion. Après correction pour tenir compte des effets de la...un simulateur de tête époxy chargé d’aluminium et recouvert de peau artificielle. La tête est soutenue par un module de cou souple rattaché à un

Ultra-high-speed graphene optical modulator design based on tight field confinement in a slot waveguide

NASA Astrophysics Data System (ADS)

Kovacevic, Goran; Phare, Christopher; Set, Sze Y.; Lipson, Michal; Yamashita, Shinji

2018-06-01

We present a design of an ultra-fast in-line graphene optical modulator on a silicon waveguide with a bandwidth exceeding 100 GHz, very small power consumption below 15 fJ/bit, and insertion loss of 1.5 dB. This is achieved by utilizing the transverse-electric-mode silicon slot to tailor the overlap of graphene electrodes, thus significantly reducing the capacitance of the device while maintaining a low insertion loss and using conservative estimates of the graphene resistance. Our design is substantiated by comprehensive finite-element-method simulations and RC circuit characterization, as well as fabrication feasibility discussion.

A linear 180 nm SOI CMOS antenna switch module using integrated passive device filters for cellular applications

NASA Astrophysics Data System (ADS)

Jie, Cui; Lei, Chen; Peng, Zhao; Xu, Niu; Yi, Liu

2014-06-01

A broadband monolithic linear single pole, eight throw (SP8T) switch has been fabricated in 180 nm thin film silicon-on-insulator (SOI) CMOS technology with a quad-band GSM harmonic filter in integrated passive devices (IPD) technology, which is developed for cellular applications. The antenna switch module (ASM) features 1.2 dB insertion loss with filter on 2G bands and 0.4 dB insertion loss in 3G bands, less than -45 dB isolation and maximum -103 dB intermodulation distortion for mobile front ends by applying distributed architecture and adaptive supply voltage generator.

Scatter correction for x-ray conebeam CT using one-dimensional primary modulation

NASA Astrophysics Data System (ADS)

Zhu, Lei; Gao, Hewei; Bennett, N. Robert; Xing, Lei; Fahrig, Rebecca

2009-02-01

Recently, we developed an efficient scatter correction method for x-ray imaging using primary modulation. A two-dimensional (2D) primary modulator with spatially variant attenuating materials is inserted between the x-ray source and the object to separate primary and scatter signals in the Fourier domain. Due to the high modulation frequency in both directions, the 2D primary modulator has a strong scatter correction capability for objects with arbitrary geometries. However, signal processing on the modulated projection data requires knowledge of the modulator position and attenuation. In practical systems, mainly due to system gantry vibration, beam hardening effects and the ramp-filtering in the reconstruction, the insertion of the 2D primary modulator results in artifacts such as rings in the CT images, if no post-processing is applied. In this work, we eliminate the source of artifacts in the primary modulation method by using a one-dimensional (1D) modulator. The modulator is aligned parallel to the ramp-filtering direction to avoid error magnification, while sufficient primary modulation is still achieved for scatter correction on a quasicylindrical object, such as a human body. The scatter correction algorithm is also greatly simplified for the convenience and stability in practical implementations. The method is evaluated on a clinical CBCT system using the Catphan© 600 phantom. The result shows effective scatter suppression without introducing additional artifacts. In the selected regions of interest, the reconstruction error is reduced from 187.2HU to 10.0HU if the proposed method is used.

Optical mixing of microwave signals in a nonlinear semiconductor laser amplifier modulator.

PubMed

Capmany, José; Sales, Salvador; Pastor, Daniel; Ortega, Beatriz

2002-02-11

In this paper we propose and evaluate the optical mixing of RF signals by means of exploiting the nonlinearity of a SLA modulator. The results show the potential for devices with low conversion losses (and even gain) and polarization insensitivity and reduced insertion losses.

Apollo 8 Mission Report

NASA Technical Reports Server (NTRS)

1969-01-01

Postflight analysis of Apollo 8 mission. Apollo 8 was the second manned flight in the program and the first manned lunar orbit mission. The crew were Frank Borman, Commander; James A. Lovell, Command Module Pilot; and William A. Anders, Lunar Module Pilot. The Apollo 8 space vehicle was launched on time from Kennedy Space Center, Florida, at 7:51:00 AM, EST, on December 21, 1968. Following a nominal boost phase, the spacecraft and S-IVB combination was inserted - into a parking orbit of 98 by 103 nautical miles. After a post-insertion checkout of spacecraft systems, the 319-second translunar injection maneuver was initiated at 2:50:37 by reignition of the S-IVB engine.

Design of an electro-optic-polymer-based Mach-Zehnder modulator

NASA Astrophysics Data System (ADS)

Haugen, Chris J.; DeCorby, Ray G.; McMullin, James N.; Pulikkaseril, C.

2000-12-01

A novel structure for an electro-optic (e-o) polymer based Mach-Zehnder modulator is proposed and its anticipated device performance is detailed. The modulator is designed using commercially available materials and makes usc of wellcharacterized electrical and optical structures. The modulator is designed to be competitive with the pertrmance of LiNbO based modulators. The results of the analysis predict a bandwidth of 20 GHz, V of 8-10 V, optical insertion loss of S d13, and a contrast ratio of approximately 13 dB.

Thermal-hydraulic analysis of the coil test facility for CFETR.

PubMed

Ren, Yong; Liu, Xiaogang; Li, Junjun; Wang, Zhaoliang; Qiu, Lilong; Du, Shijun; Li, Guoqiang; Gao, Xiang

2016-01-01

Performance test of the China Fusion Engineering Test Reactor (CFETR) central solenoid (CS) and toroidal field (TF) insert coils is of great importance to evaluate the CFETR magnet performance in relevant operation conditions. The superconducting magnet of the coil test facility for CFETR is being designed with the aim of providing a background magnetic field to test the CFETR CS insert and TF insert coils. The superconducting magnet consists of the inner module with Nb 3 Sn coil and the outer module with NbTi coil. The superconducting magnet is designed to have a maximum magnetic field of 12.59 T and a stored energy of 436.6 MJ. An active quench protection circuit and the positive temperature coefficient dump resistor were adopted to transfer the stored magnetic energy. The temperature margin behavior of the test facility for CFETR satisfies the design criteria. The quench analysis of the test facility shows that the cable temperature and the helium pressure inside the jacket are within the design criteria.

Critical technology experiment results for lightweight space heat receiver

NASA Technical Reports Server (NTRS)

Schneider, Michael G.; Brege, Mark A.; Heidenreich, Gary R.

1991-01-01

Critical technology experiments have been performed on thermal energy storage modules in support of the NASA Advanced Solar Dynamic Brayton Heat Receiver Program. The modules, wedge-shaped canisters containing lithium fluoride (LiF), were designed to minimize the mechanical stresses that occur during the phase change of the LiF. Nickel foam inserts were placed in two of the test canisters to provide thermal conductivity enhancement and to distribute the void volume throughout the canister. A procedure was developed for reducing the nickel oxides on the nickel foam to enhance the wicking ability of the foam. The canisters were filled with LiF and closure-welded at the NASA Lewis Research Center. Two canisters, one with a nickel foam insert, the other without an insert, were thermally cycled in various orientations in a fluidized bed furnace. Computer-aided tomography was successfully used to nondestructively determine void locations in the canisters. Finally, canister dimensional stability was measured after thermal cycling with an inspection fixture.

Effect of graphene tunnel barrier on Schottky barrier height of Heusler alloy Co2MnSi/graphene/n-Ge junction

NASA Astrophysics Data System (ADS)

Gui-fang, Li; Jing, Hu; Hui, Lv; Zhijun, Cui; Xiaowei, Hou; Shibin, Liu; Yongqian, Du

2016-02-01

We demonstrate that the insertion of a graphene tunnel barrier between Heusler alloy Co2MnSi and the germanium (Ge) channel modulates the Schottky barrier height and the resistance-area product of the spin diode. We confirm that the Fermi level is depinned and a reduction in the electron Schottky barrier height (SBH) occurs following the insertion of the graphene layer between Co2MnSi and Ge. The electron SBH is modulated in the 0.34 eV-0.61 eV range. Furthermore, the transport mechanism changes from rectifying to symmetric tunneling following the insertion. This behavior provides a pathway for highly efficient spin injection from a Heusler alloy into a Ge channel with high electron and hole mobility. Project supported by the National Natural Science Foundation of China (Grant No. 61504107) and the Fundamental Research Funds for the Central Universities, China (Grant Nos. 3102014JCQ01059 and 3102015ZY043).

Evaluation of App-Based Serious Gaming as a Training Method in Teaching Chest Tube Insertion to Medical Students: Randomized Controlled Trial

PubMed Central

Ober, Julian; Walker, Tilman; Bergdolt, Christian; Friedrich, Mirco; Müller-Stich, Beat Peter; Forchheim, Franziska; Fischer, Christian; Schmidmaier, Gerhard; Tanner, Michael C

2018-01-01

Background The insertion of a chest tube should be as quick and accurate as possible to maximize the benefit and minimize possible complications for the patient. Therefore, comprehensive training and assessment before an emergency situation are essential for proficiency in chest tube insertion. Serious games have become more prevalent in surgical training because they enable students to study and train a procedure independently, and errors made have no effect on patients. However, up-to-date evidence regarding the effect of serious games on performance in procedures in emergency medicine remains scarce. Objective The aim of this study was to investigate the serious gaming approach in teaching medical students an emergency procedure (chest tube insertion) using the app Touch Surgery and a modified objective structural assessment of technical skills (OSATS). Methods In a prospective, rater-blinded, randomized controlled trial, medical students were randomized into two groups: intervention group or control group. Touch Surgery has been established as an innovative and cost-free app for mobile devices. The fully automatic software enables users to train medical procedures and afterwards self-assess their training effort. The module chest tube insertion teaches each key step in the insertion of a chest tube and enables users the meticulous application of a chest tube. In contrast, the module “Thoracocentesis” discusses a basic thoracocentesis. All students attended a lecture regarding chest tube insertion (regular curriculum) and afterwards received a Touch Surgery training lesson: intervention group used the module chest tube insertion and the control group used Thoracocentesis as control training. Participants’ performance in chest tube insertion on a porcine model was rated on-site via blinded face-to-face rating and via video recordings using a modified OSATS tool. Afterwards, every participant received an individual questionnaire for self-evaluation. Here, trainees gave information about their individual training level, as well as previous experiences, gender, and hobbies. Primary end point was operative performance during chest tube insertion by direct observance. Results A total of 183 students enrolled, 116 students participated (63.4%), and 21 were excluded because of previous experiences in chest tube insertion. Students were randomized to the intervention group (49/95, 52%) and control group (46/95, 48%). The intervention group performed significantly better than the control group (Intervention group: 38.0 [I50=7.0] points; control group: 30.5 [I50=8.0] points; P<.001). The intervention group showed significantly improved economy of time and motion (P=.004), needed significantly less help (P<.001), and was more confident in handling of instruments (P<.001) than the control group. Conclusions The results from this study show that serious games are a valid and effective tool in education of operative performance in chest tube insertion. We believe that serious games should be implemented in the surgical curriculum, as well as residency programs, in addition to traditional learning methods. Trial Registration German Clinical Trials Register (DRKS) DRKS00009994; https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00009994 (Archived by Webcite at http://www.webcitation.org/6ytWF1CWg) PMID:29784634

Mexico and California: 1900-1920. Project Mexico.

ERIC Educational Resources Information Center

White, Peter

This document is an outline for a module which can be inserted, in whole or in part, in community college courses on California and/or Southwest United States history, Mexican-American or Chicano history, Mexican history, and United States history. The module examines the close ties--political, economic, and social--between Mexico and California…

Standard Hardware Acquisition and Reliability Program's (SHARP's) efforts in incorporating fiber optic interconnects into standard electronic module (SEM) connectors

NASA Astrophysics Data System (ADS)

Riggs, William R.

1994-05-01

SHARP is a Navy wide logistics technology development effort aimed at reducing the acquisition costs, support costs, and risks of military electronic weapon systems while increasing the performance capability, reliability, maintainability, and readiness of these systems. Lower life cycle costs for electronic hardware are achieved through technology transition, standardization, and reliability enhancement to improve system affordability and availability as well as enhancing fleet modernization. Advanced technology is transferred into the fleet through hardware specifications for weapon system building blocks of standard electronic modules, standard power systems, and standard electronic systems. The product lines are all defined with respect to their size, weight, I/O, environmental performance, and operational performance. This method of defining the standard is very conducive to inserting new technologies into systems using the standard hardware. This is the approach taken thus far in inserting photonic technologies into SHARP hardware. All of the efforts have been related to module packaging; i.e. interconnects, component packaging, and module developments. Fiber optic interconnects are discussed in this paper.

Modulation of Crystal Surface and Lattice by Doping: Achieving Ultrafast Metal-Ion Insertion in Anatase TiO2.

PubMed

Wang, Hsin-Yi; Chen, Han-Yi; Hsu, Ying-Ya; Stimming, Ulrich; Chen, Hao Ming; Liu, Bin

2016-10-26

We report that an ultrafast kinetics of reversible metal-ion insertion can be realized in anatase titanium dioxide (TiO 2 ). Niobium ions (Nb 5+ ) were carefully chosen to dope and drive anatase TiO 2 into very thin nanosheets standing perpendicularly onto transparent conductive electrode (TCE) and simultaneously construct TiO 2 with an ion-conducting surface together with expanded ion diffusion channels, which enabled ultrafast metal ions to diffuse across the electrolyte/solid interface and into the bulk of TiO 2 . To demonstrate the superior metal-ion insertion rate, the electrochromic features induced by ion intercalation were examined, which exhibited the best color switching speed of 4.82 s for coloration and 0.91 s for bleaching among all reported nanosized TiO 2 devices. When performed as the anode for the secondary battery, the modified TiO 2 was capable to deliver a highly reversible capacity of 61.2 mAh/g at an ultrahigh specific current rate of 60 C (10.2 A/g). This fast metal-ion insertion behavior was systematically investigated by the well-controlled electrochemical approaches, which quantitatively revealed both the enhanced surface kinetics and bulk ion diffusion rate. Our study could provide a facile methodology to modulate the ion diffusion kinetics for metal oxides.

Prototype positron emission tomography insert with electro-optical signal transmission for simultaneous operation with MRI.

PubMed

Olcott, Peter; Kim, Ealgoo; Hong, Keyjo; Lee, Brian J; Grant, Alexander M; Chang, Chen-Ming; Glover, Gary; Levin, Craig S

2015-05-07

The simultaneous acquisition of PET and MRI data shows promise to provide powerful capabilities to study disease processes in human subjects, guide the development of novel treatments, and monitor therapy response and disease progression. A brain-size PET detector ring insert for an MRI system is being developed that, if successful, can be inserted into any existing MRI system to enable simultaneous PET and MRI images of the brain to be acquired without mutual interference. The PET insert uses electro-optical coupling to relay all the signals from the PET detectors out of the MRI system using analog modulated lasers coupled to fiber optics. Because the fibers use light instead of electrical signals, the PET detector can be electrically decoupled from the MRI making it partially transmissive to the RF field of the MRI. The SiPM devices and low power lasers were powered using non-magnetic MRI compatible batteries. Also, the number of laser-fiber channels in the system was reduced using techniques adapted from the field of compressed sensing. Using the fact that incoming PET data is sparse in time and space, electronic circuits implementing constant weight codes uniquely encode the detector signals in order to reduce the number of electro-optical readout channels by 8-fold. Two out of a total of sixteen electro-optical detector modules have been built and tested with the entire RF-shielded detector gantry for the PET ring insert. The two detectors have been tested outside and inside of a 3T MRI system to study mutual interference effects and simultaneous performance with MRI. Preliminary results show that the PET insert is feasible for high resolution simultaneous PET/MRI imaging for applications in the brain.

Prototype positron emission tomography insert with electro-optical signal transmission for simultaneous operation with MRI

NASA Astrophysics Data System (ADS)

Olcott, Peter; Kim, Ealgoo; Hong, Keyjo; Lee, Brian J.; Grant, Alexander M.; Chang, Chen-Ming; Glover, Gary; Levin, Craig S.

2015-05-01

The simultaneous acquisition of PET and MRI data shows promise to provide powerful capabilities to study disease processes in human subjects, guide the development of novel treatments, and monitor therapy response and disease progression. A brain-size PET detector ring insert for an MRI system is being developed that, if successful, can be inserted into any existing MRI system to enable simultaneous PET and MRI images of the brain to be acquired without mutual interference. The PET insert uses electro-optical coupling to relay all the signals from the PET detectors out of the MRI system using analog modulated lasers coupled to fiber optics. Because the fibers use light instead of electrical signals, the PET detector can be electrically decoupled from the MRI making it partially transmissive to the RF field of the MRI. The SiPM devices and low power lasers were powered using non-magnetic MRI compatible batteries. Also, the number of laser-fiber channels in the system was reduced using techniques adapted from the field of compressed sensing. Using the fact that incoming PET data is sparse in time and space, electronic circuits implementing constant weight codes uniquely encode the detector signals in order to reduce the number of electro-optical readout channels by 8-fold. Two out of a total of sixteen electro-optical detector modules have been built and tested with the entire RF-shielded detector gantry for the PET ring insert. The two detectors have been tested outside and inside of a 3T MRI system to study mutual interference effects and simultaneous performance with MRI. Preliminary results show that the PET insert is feasible for high resolution simultaneous PET/MRI imaging for applications in the brain.

Startup of RAPID-L Lunar Base Reactor by Lithium Release Module

NASA Astrophysics Data System (ADS)

Kambe, Mitsuru

The 200 kWe uranium-nitride fueled lithium cooled fast reactor concept RAPID-L to be combined with thermoelectric power conversion system for lunar base power system is demonstrated. Unique challenges in reactivity control systems design have been attempted in RAPID-L concept. The reactor involves the following innovative reactivity control systems: Lithium Expansion Modules (LEM) for inherent reactivity feedback, Lithium Injection Modules (LIM) for inherent ultimate shutdown, and Lithium Release Modules (LRM) for automated reactor startup. All these systems adopt lithium-6 as a liquid poison instead of conventional B4C rods or Be reflectors. These systems are effective independent of the magnitude and direction of the gravity force. In 2006, however, the following design amendment has been made. 1) B4C poison rods were added to ensure criticality safety in unintended positive reactivity insertion by LRMs due to fire in the launch phase accident; because LRM freeze seal melts at 800°C which result in positive reactivity insertion. 2) Lower hot standby temperature of 200°C was adopted instead of conventional 800°C to reduce the external power at the startup. In this paper, development of the LRM orifice which dominates the startup transient of RAPID-L is discussed. An attention was focused how to achieve sufficiently small flow rate of 6Li in the orifice because it enables moderate positive reactivity insertion rate. The LRM orifice performance has been confirmed using 0.5 mm diameter SUS316 orifice/lithium flow test setup in the glove box.

Spin dependent transport properties of Mn-Ga/MgO/Mn-Ga magnetic tunnel junctions with metal(Mg, Co, Cr) insertion layer

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

Liang, S. H.; Tao, L. L.; Liu, D. P., E-mail: dpliu@iphy.ac.cn

We report a first principles theoretical investigation of spin polarized quantum transport in Mn{sub 2}Ga/MgO/Mn{sub 2}Ga and Mn{sub 3}Ga/MgO/Mn{sub 3}Ga magnetic tunneling junctions (MTJs) with the consideration of metal(Mg, Co, Cr) insertion layer effect. By changing the concentration of Mn, our calculation shows a considerable disparity in transport properties: A tunneling magnetoresistance (TMR) ratio of 852% was obtained for Mn{sub 2}Ga-based MTJs, however, only a 5% TMR ratio for Mn{sub 3}Ga-based MTJs. In addition, the influence of insertion layer has been considered in our calculation. We found the Co insertion layer can increase the TMR of Mn{sub 2}Ga-based MTJ tomore » 904%; however, the Cr insertion layer can decrease the TMR by 668%; A negative TMR ratio can be obtained with Mg insertion layer. Our work gives a comprehensive understanding of the influence of different insertion layer in Mn-Ga based MTJs. It is proved that, due to the transmission can be modulated by the interfacial electronic structure of insertion, the magnetoresistance ratio of Mn{sub 2}Ga/MgO/Mn{sub 2}Ga MTJ can be improved by inserting Co layer.« less

Nuclear Engineering Computer Modules: Reactor Dynamics, RD-1 and RD-2.

ERIC Educational Resources Information Center

Onega, Ronald J.

The objective of the Reactor Dynamics Module, RD-1, is to obtain the kinetics equation without feedback and solve the kinetics equations numerically for one to six delayed neutron groups for time varying reactivity insertions. The computer code FUMOKI (Fundamental Mode Kinetics) will calculate the power as a function of time for either uranium or…

Evaluation of App-Based Serious Gaming as a Training Method in Teaching Chest Tube Insertion to Medical Students: Randomized Controlled Trial.

PubMed

Haubruck, Patrick; Nickel, Felix; Ober, Julian; Walker, Tilman; Bergdolt, Christian; Friedrich, Mirco; Müller-Stich, Beat Peter; Forchheim, Franziska; Fischer, Christian; Schmidmaier, Gerhard; Tanner, Michael C

2018-05-21

The insertion of a chest tube should be as quick and accurate as possible to maximize the benefit and minimize possible complications for the patient. Therefore, comprehensive training and assessment before an emergency situation are essential for proficiency in chest tube insertion. Serious games have become more prevalent in surgical training because they enable students to study and train a procedure independently, and errors made have no effect on patients. However, up-to-date evidence regarding the effect of serious games on performance in procedures in emergency medicine remains scarce. The aim of this study was to investigate the serious gaming approach in teaching medical students an emergency procedure (chest tube insertion) using the app Touch Surgery and a modified objective structural assessment of technical skills (OSATS). In a prospective, rater-blinded, randomized controlled trial, medical students were randomized into two groups: intervention group or control group. Touch Surgery has been established as an innovative and cost-free app for mobile devices. The fully automatic software enables users to train medical procedures and afterwards self-assess their training effort. The module chest tube insertion teaches each key step in the insertion of a chest tube and enables users the meticulous application of a chest tube. In contrast, the module "Thoracocentesis" discusses a basic thoracocentesis. All students attended a lecture regarding chest tube insertion (regular curriculum) and afterwards received a Touch Surgery training lesson: intervention group used the module chest tube insertion and the control group used Thoracocentesis as control training. Participants' performance in chest tube insertion on a porcine model was rated on-site via blinded face-to-face rating and via video recordings using a modified OSATS tool. Afterwards, every participant received an individual questionnaire for self-evaluation. Here, trainees gave information about their individual training level, as well as previous experiences, gender, and hobbies. Primary end point was operative performance during chest tube insertion by direct observance. A total of 183 students enrolled, 116 students participated (63.4%), and 21 were excluded because of previous experiences in chest tube insertion. Students were randomized to the intervention group (49/95, 52%) and control group (46/95, 48%). The intervention group performed significantly better than the control group (Intervention group: 38.0 [I 50 =7.0] points; control group: 30.5 [I 50 =8.0] points; P<.001). The intervention group showed significantly improved economy of time and motion (P=.004), needed significantly less help (P<.001), and was more confident in handling of instruments (P<.001) than the control group. The results from this study show that serious games are a valid and effective tool in education of operative performance in chest tube insertion. We believe that serious games should be implemented in the surgical curriculum, as well as residency programs, in addition to traditional learning methods. German Clinical Trials Register (DRKS) DRKS00009994; https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00009994 (Archived by Webcite at http://www.webcitation.org/6ytWF1CWg). ©Patrick Haubruck, Felix Nickel, Julian Ober, Tilman Walker, Christian Bergdolt, Mirco Friedrich, Beat Peter Müller-Stich, Franziska Forchheim, Christian Fischer, Gerhard Schmidmaier, Michael C Tanner. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 21.05.2018.

Space Station racks weight and CG measurement using the rack insertion end-effector

NASA Technical Reports Server (NTRS)

Brewer, William V.

1994-01-01

The objective was to design a method to measure weight and center of gravity (C.G.) location for Space Station Modules by adding sensors to the existing Rack Insertion End Effector (RIEE). Accomplishments included alternative sensor placement schemes organized into categories. Vendors were queried for suitable sensor equipment recommendations. Inverse mathematical models for each category determine expected maximum sensor loads. Sensors are selected using these computations, yielding cost and accuracy data. Accuracy data for individual sensors are inserted into forward mathematical models to estimate the accuracy of an overall sensor scheme. Cost of the schemes can be estimated. Ease of implementation and operation are discussed.

Sensitivity Analysis of Digital I&C Modules in Protection and Safety Systems

NASA Astrophysics Data System (ADS)

Khalil Ur, Rahman; Zubair, M.; Heo, G.

2013-12-01

This research is performed to examine the sensitivity of digital Instrumentation and Control (I&C) components and modules used in regulating and protection systems architectures of nuclear industry. Fault Tree Analysis (FTA) was performed for four configurations of RPS channel architecture. The channel unavailability has been calculated by using AIMS-PSA, which comes out 4.517E-03, 2.551E-03, 2.246E-03 and 2.7613-04 for architecture configuration I, II, III and IV respectively. It is observed that unavailability decreases by 43.5 % & 50.4% by inserting partial redundancy whereas maximum reduction of 93.9 % in unavailability happens when double redundancy is inserted in architecture. Coincidence module output failure and bi-stable output failures are identified as sensitive failures by Risk Reduction Worth (RRW) and Fussell-Vesely (FV) importance. RRW highlights that risk from coincidence processor output failure can reduced by 48.83 folds and FV indicates that BP output is sensitive by 0.9796 (on a scale of 1).

An abstract model of rogue code insertion into radio frequency wireless networks. The effects of computer viruses on the Program Management Office

NASA Astrophysics Data System (ADS)

Feudo, Christopher V.

1994-04-01

This dissertation demonstrates that inadequately protected wireless LANs are more vulnerable to rogue program attack than traditional LANs. Wireless LANs not only run the same risks as traditional LANs, but they also run additional risks associated with an open transmission medium. Intruders can scan radio waves and, given enough time and resources, intercept, analyze, decipher, and reinsert data into the transmission medium. This dissertation describes the development and instantiation of an abstract model of the rogue code insertion process into a DOS-based wireless communications system using radio frequency (RF) atmospheric signal transmission. The model is general enough to be applied to widely used target environments such as UNIX, Macintosh, and DOS operating systems. The methodology and three modules, the prober, activator, and trigger modules, to generate rogue code and insert it into a wireless LAN were developed to illustrate the efficacy of the model. Also incorporated into the model are defense measures against remotely introduced rogue programs and a cost-benefit analysis that determined that such defenses for a specific environment were cost-justified.

Nonreciprocal Gain in Non-Hermitian Time-Floquet Systems

NASA Astrophysics Data System (ADS)

Koutserimpas, Theodoros T.; Fleury, Romain

2018-02-01

We explore the unconventional wave scattering properties of non-Hermitian systems in which amplification or damping are induced by time-periodic modulation. These non-Hermitian time-Floquet systems are capable of nonreciprocal operations in the frequency domain, which can be exploited to induce novel physical phenomena such as unidirectional wave amplification and perfect nonreciprocal response with zero or even negative insertion losses. This unique behavior is obtained by imparting a specific low-frequency time-periodic modulation to the complex coupling between lossless resonators, promoting only upward frequency conversion, and leading to nonreciprocal parametric gain. We provide a full-wave demonstration of our findings in a one-way microwave amplifier, and establish the potential of non-Hermitian time-Floquet devices for insertion-loss free microwave isolation and unidirectional parametric amplification.

Photovoltaic panel clamp

DOEpatents

Mittan, Margaret Birmingham [Oakland, CA; Miros, Robert H. J. [Fairfax, CA; Brown, Malcolm P [San Francisco, CA; Stancel, Robert [Loss Altos Hills, CA

2012-06-05

A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

Photovoltaic panel clamp

DOEpatents

Brown, Malcolm P.; Mittan, Margaret Birmingham; Miros, Robert H. J.; Stancel, Robert

2013-03-19

A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

Hybrid plasmonic electro-optical absorption modulator based on epsilon-near-zero characteristics of ITO

NASA Astrophysics Data System (ADS)

Abdelatty, M. Y.; Badr, M. M.; Swillam, M. A.

2018-03-01

Using transparent conducting oxides (TCOs), like indium-tin-oxide (ITO), for optical modulation attracted research interest because of their epsilon-near-zero (ENZ) characteristics at telecom wavelengths. Utilizing indium-tin-oxide (ITO) in multilayer structure modulators, optical absorption of the active ITO layer can be electrically modulated over a large spectrum range. Although they show advances over common silicon electro-optical modulators (EOMs), they suffer from high insertion losses. To reduce insertion losses and device footprints without sacrificing bandwidth and modulation strength, slot waveguides are promising options because of their high optical confinement. In this paper, we present the study and the design of an electro-optical absorption modulator based on electrically tuning ITO carrier density inside a MOS structure. The device structure is based on dielectric slot waveguide with an ITO plasmonic waveguide modulation section. By changing the dimensions, the effective refractive indices for the slot mode and the off-sate mode of the plasmonic section can be matched. When applying electric field to the plasmonic section (on-state), carriers are generated at the ITO-dielectric interface that result in changing the layer where the electric field is confined from a transparent layer into a lossy layer. A finite difference time domain method with perfect matching layer (PML) absorbing boundary conditions is taken up to simulate and analyze this design. An extinction ratio of 2.3 dB is achieved for a 1-μm-short modulation section, at the telecommunications wavelength (1.55 μm). This EOM has advantages of simple design, easy fabrication, compact size, compatibility with existing silicon photonics platforms, as well as broadband performance.

Solar Cell Modules With Improved Backskin

DOEpatents

Chevrefils, Andre; Grigore, Daniel Gheorghe

2001-01-23

The present invention relates to gas turbines and more particularly to a device for controlling the flow of cooling air through a flowpath in a turbine blade. The device can be inserted in the inlet opening of the blade flowpath and be retained therein. The device comprises a plug member for adjusting the flow of cooling air through the flowpath. The plug member comprises a retaining portion for retaining the plug member at the inlet opening of the flowpath and a blocking portion inserted within the flowpath for reducing the cross-sectional area of the inlet opening. Such a device is inexpensive and can be easily inserted in the inlet opening of a blade flowpath and retained therein.

Easily-wired toggle switch

NASA Technical Reports Server (NTRS)

Dean, W. T.; Stringer, E. J.

1979-01-01

Crimp-type connectors reduce assembly and disassembly time. With design, no switch preparation is necessary and socket contracts are crimped to wires inserted in module attached to back of toggle switch engaging pins inside module to make electrical connections. Wires are easily removed with standard detachment tool. Design can accommodate wires of any gage and as many terminals can be placed on switch as wire gage and switch dimensions will allow.

Research on Shore-Ship Photonic Link Performance for Two- Frequency-Band Signals

NASA Astrophysics Data System (ADS)

Zuo, Yanqin; Cong, Bo

2016-02-01

Ka and Ku bands links for shore-ship communications suffer limited bandwidth and high loss. In this paper, photonics-based links are proposed and modeled. The principle of phase modulation (PM) is elaborated and analyzed. It is showed that PM can effectively suppress high-order inter-modulation distortion (IMD), reduce the insert loss and improve the reliability of the system.

A Predictive Model of Intein Insertion Site for Use in the Engineering of Molecular Switches

PubMed Central

Apgar, James; Ross, Mary; Zuo, Xiao; Dohle, Sarah; Sturtevant, Derek; Shen, Binzhang; de la Vega, Humberto; Lessard, Philip; Lazar, Gabor; Raab, R. Michael

2012-01-01

Inteins are intervening protein domains with self-splicing ability that can be used as molecular switches to control activity of their host protein. Successfully engineering an intein into a host protein requires identifying an insertion site that permits intein insertion and splicing while allowing for proper folding of the mature protein post-splicing. By analyzing sequence and structure based properties of native intein insertion sites we have identified four features that showed significant correlation with the location of the intein insertion sites, and therefore may be useful in predicting insertion sites in other proteins that provide native-like intein function. Three of these properties, the distance to the active site and dimer interface site, the SVM score of the splice site cassette, and the sequence conservation of the site showed statistically significant correlation and strong predictive power, with area under the curve (AUC) values of 0.79, 0.76, and 0.73 respectively, while the distance to secondary structure/loop junction showed significance but with less predictive power (AUC of 0.54). In a case study of 20 insertion sites in the XynB xylanase, two features of native insertion sites showed correlation with the splice sites and demonstrated predictive value in selecting non-native splice sites. Structural modeling of intein insertions at two sites highlighted the role that the insertion site location could play on the ability of the intein to modulate activity of the host protein. These findings can be used to enrich the selection of insertion sites capable of supporting intein splicing and hosting an intein switch. PMID:22649521

Word and frame synchronization with verification for PPM optical communications

NASA Technical Reports Server (NTRS)

Marshall, William K.

1986-01-01

A method for obtaining word and frame synchronization in pulse position modulated optical communication systems is described. The method uses a short sync sequence inserted at the beginning of each data frame and a verification procedure to distinguish between inserted and randomly occurring sequences at the receiver. This results in an easy to implement sync system which provides reliable synchronization even at high symbol error rates. Results are given for the application of this approach to a highly energy efficient 256-ary PPM test system.

Ligand interaction scan: a general method for engineering ligand-sensitive protein alleles.

PubMed

Erster, Oran; Eisenstein, Miriam; Liscovitch, Mordechai

2007-05-01

The ligand interaction scan (LIScan) method is a general procedure for engineering small molecule ligand-regulated forms of a protein that is complementary to other 'reverse' genetic and chemical-genetic methods for drug-target validation. It involves insertional mutagenesis by a chemical-genetic 'switch', comprising a genetically encoded peptide module that binds with high affinity to a small-molecule ligand. We demonstrated the method with TEM-1 beta-lactamase, using a tetracysteine hexapeptide insert and a biarsenical fluorescein ligand (FlAsH).

Online Assessment of Voltage Stability in Power Systems with PMUs

NASA Astrophysics Data System (ADS)

Chitare, Prasad Bhagwat; Murthy Balijepalli, V. S. K.; Khaparde, S. A.

2013-05-01

Abstract: For the assessment of voltage instability which comprises the detection of voltage instability and identification of critical buses, two indices namely, system wide Qtax, and bus-specific qtax, are proposed. The Qtax, based on the sensitivity of the reactive power injections to the loading in the system provides early detection of impending voltage instability. The computed qtax indices identify the critcal buses among the load buses in the system. The identified critical buses provided optimal lacations for the corrective control actions for averting voltage instability. Additionally, for voltage stability monitoring, determining the poing of exhaustion of the reactive reserves in system is also crucial. This is addressed by proposed Q-Monitoring Index (QMI), which is the ratio of the reactive component of the source current to the sink current that flows through the adjacent transmission line. These proposed indices together can provide early indication to impending voltage instability. This has been illustrated on IEEE-39 bus system. The reactive support on identified critical buses results in maximum increase in the loadability of the system.

Strongly-guided indium phosphide/indium gallium arsenic phosphide Mach-Zehnder modulator for optical communications

NASA Astrophysics Data System (ADS)

Betty, Ian Brian

2006-12-01

The development of strongly-guided InP/In1-x GaxAsyP 1-y based Mach-Zehnder optical modulators for 10Gb/s telecommunications is detailed. The modulators have insertion losses including coupling as low as 4.5dB, due to the incorporation of monolithically integrated optical mode spot-size converters (SSC's). The modulators are optimized to produce system performance that is independent of optical coupling alignment and for wavelength operation between 1525nm and 1565nm. A negatively chirped Mach-Zehnder modulator design is demonstrated, giving optimal dispersion-limited reach for 10Gb/s ON/OFF-keying modulation. It is shown that the optical system performance for this design can be determined from purely DC based optical measurements. A Mach-Zehnder modulator design invoking nearly no transient frequency shifts under intensity modulation is also presented, for the first time, using phase-shifter implementations based on the Quantum-Confined-Stark-Effect (QCSE). The performance impact on the modulator from the higher-order vertical and lateral waveguide modes found in strongly-guided waveguides has been determined. The impact of these higher-order modes has been minimized using the design of the waveguide bends, MMI structures, and doping profiles. The fabrication process and optical design for the spot-size mode converters are also thoroughly explored. The SSC structures are based on butt-joined vertically tapered passive waveguide cores within laterally flared strongly-guided ridges, making them compatible with any strong-guiding waveguide structure. The flexibility of the SSC process is demonstrated by the superior performance it has also enabled in a 40Gb/s electro-absorption modulator. The presented electro-absorption modulator has 3.6dB fiber-to-fiber insertion loss, polarization dependent loss (PDL) of only 0.3dB over 15dB extinction, and low absolute chirp (|alpha H| < 0.6) over the full dynamic range.

Low-noise magnetometer based on inductance modulation in high-critical-temperature superconductor coil

NASA Astrophysics Data System (ADS)

Enpuku, Keiji; Matsuo, Masaaki; Yoshida, Yujiro; Yamashita, Shigeya; Sasayama, Teruyoshi; Yoshida, Takashi

2018-06-01

We developed a magnetometer based on inductance modulation of a coil made from a high-critical-temperature superconducting material. The coil inductance was modulated over time via a modulation current applied to a magnetic wire that was inserted into the coil. The magnetic field was then converted into a signal voltage using this time-dependent inductance. The relationship between magnetometer performance and the modulation current conditions was studied. Under appropriate conditions, the magnetometer had responsivity of 885 V/T. The magnetic field noise was 1.3 pT/Hz1/2 in the white noise region and 5.6 pT/Hz1/2 at f = 1 Hz.

Impact of the LHC beam abort kicker prefire on high luminosity insertion and CMS detector performance

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

A.I. Drozhdin, N.V. Mokhov and M. Huhtinen

1999-04-13

The effect of possible accidental beam loss in LHC on the IP5 insertion elements and CMS detector is studied via realistic Monte Carlo simulations. Such beam loss could be the consequence of an unsynchronized abort or in worst case an accidental prefire of one of the abort kicker modules. Simulations with the STRUCT code show that this beam losses would take place in the IP5 inner and outer triplets. MARS simulations of the hadronic and electro-magnetic cascades induced in such an event indicate severe heating of the inner triplet quadrupoles. In order to protect the IP5 elements, two methods aremore » proposed: a set of shadow collimators in the outer triplet and a prefired module compensation using a special module charged with an opposite voltage (antikicker). The remnants of the accidental beam loss entering the experimental hall have been used as input for FLUKA simulations in the CMS detector. It is shown that it is vital to take measures to reliably protect the expensive CMS tracker components.« less

Design and analysis of low-loss linear analog phase modulator for deep space spacecraft X-band transponder (DST) application

NASA Technical Reports Server (NTRS)

Mysoor, Narayan R.; Mueller, Robert O.

1991-01-01

This paper summarizes the design concepts, analyses, and the development of an X-band transponder low-loss linear phase modulator for deep space spacecraft applications. A single section breadboard circulator-coupled reflection phase modulator has been analyzed, fabricated, and evaluated. Two- and three-cascaded sections have been modeled and simulations performed to provide an X-band DST phase modulator with +/- 2.5 radians of peak phase deviation to accommodate down-link signal modulation with composite telemetry data and ranging with a deviation linearity tolerance +/- 8 percent and insertion loss of less than 10 +/- 0.5 dB. A two-section phase modulator using constant gamma hyperabrupt varactors and an efficient modulator driver circuit was breadboarded. The measured results satisfy the DST phase modulator requirements, and excellent agreement with the predicted results.

Religion and psychosis: a common evolutionary trajectory?

PubMed

Dein, Simon; Littlewood, Roland

2011-07-01

In this article we propose that schizophrenia and religious cognition engage cognate mental modules in the over-attribution of agency and the overextension of theory of mind. We argue similarities and differences between assumptions of ultrahuman agents with omniscient minds and certain ''pathological'' forms of thinking in schizophrenia: thought insertion, withdrawal and broadcasting, and delusions of reference. In everyday religious cognition agency detection and theory of mind modules function ''normally,'' whereas in schizophrenia both modules are impaired. It is suggested that religion and schizophrenia have perhaps had a related evolutionary trajectory.

Monolithic device for modelocking and stabilization of frequency combs.

PubMed

Lee, C-C; Hayashi, Y; Silverman, K L; Feldman, A; Harvey, T; Mirin, R P; Schibli, T R

2015-12-28

We demonstrate a device that integrates a III-V semiconductor saturable absorber mirror with a graphene electro-optic modulator, which provides a monolithic solution to modelocking and noise suppression in a frequency comb. The device offers a pure loss modulation bandwidth exceeding 5 MHz and only requires a low voltage driver. This hybrid device provides not only compactness and simplicity in laser cavity design, but also small insertion loss, compared to the previous metallic-mirror-based modulators. We believe this work paves the way to portable and fieldable phase-coherent frequency combs.

Influence of Screw Length and Bone Thickness on the Stability of Temporary Implants

PubMed Central

Fernandes, Daniel Jogaib; Elias, Carlos Nelson; Ruellas, Antônio Carlos de Oliveira

2015-01-01

The purpose of this work was to study the influence of screw length and bone thickness on the stability of temporary implants. A total of 96 self-drilling temporary screws with two different lengths were inserted into polyurethane blocks (n = 66), bovine femurs (n = 18) and rabbit tibia (n = 12) with different cortical thicknesses (1 to 8 mm). Screws insertion in polyurethane blocks was assisted by a universal testing machine, torque peaks were collected by a digital torquemeter and bone thickness was monitored by micro-CT. The results showed that the insertion torque was significantly increased with the thickness of cortical bone from polyurethane (p < 0.0001), bovine (p = 0.0035) and rabbit (p < 0.05) sources. Cancellous bone improved significantly the mechanical implant stability. Insertion torque and insertion strength was successfully moduled by equations, based on the cortical/cancellous bone behavior. Based on the results, insertion torque and bone strength can be estimate in order to prevent failure of the cortical layer during temporary screw placement. The stability provided by a cortical thickness of 2 or 1 mm coupled to cancellous bone was deemed sufficient for temporary implants stability. PMID:28793582

The FE-I4 Pixel Readout Chip and the IBL Module

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

Barbero, Marlon; Arutinov, David; Backhaus, Malte

2012-05-01

FE-I4 is the new ATLAS pixel readout chip for the upgraded ATLAS pixel detector. Designed in a CMOS 130 nm feature size process, the IC is able to withstand higher radiation levels compared to the present generation of ATLAS pixel Front-End FE-I3, and can also cope with higher hit rate. It is thus suitable for intermediate radii pixel detector layers in the High Luminosity LHC environment, but also for the inserted layer at 3.3 cm known as the 'Insertable B-Layer' project (IBL), at a shorter timescale. In this paper, an introduction to the FE-I4 will be given, focusing on testmore » results from the first full size FE-I4A prototype which has been available since fall 2010. The IBL project will be introduced, with particular emphasis on the FE-I4-based module concept.« less

Dispersed solar thermal generation employing parabolic dish-electric transport with field modulated generator systems

NASA Technical Reports Server (NTRS)

Ramakumar, R.; Bahrami, K.

1981-01-01

This paper discusses the application of field modulated generator systems (FMGS) to dispersed solar-thermal-electric generation from a parabolic dish field with electric transport. Each solar generation unit is rated at 15 kWe and the power generated by an array of such units is electrically collected for insertion into an existing utility grid. Such an approach appears to be most suitable when the heat engine rotational speeds are high (greater than 6000 r/min) and, in particular, if they are operated in the variable speed mode and if utility-grade a.c. is required for direct insertion into the grid without an intermediate electric energy storage and reconversion system. Predictions of overall efficiencies based on conservative efficiency figures for the FMGS are in the range of 25 per cent and should be encouraging to those involved in the development of cost-effective dispersed solar thermal power systems.

Fluorescence Spectroscopy in Thermodynamic and Kinetic Analysis of pH-Dependent Membrane Protein Insertion

PubMed Central

Ladokhin, Alexey S.

2016-01-01

Experimental determination of the free energy stabilizing the structure of membrane proteins in their native lipid environment is undermined by a lack of appropriate methods and suitable model systems. Here, we demonstrate how fluorescence correlation spectroscopy can be used to characterize thermodynamics of pH-triggered bilayer insertion of nonconstitutive membrane proteins (e.g., bacterial toxins, colicins). The experimental design is guided by the appropriate thermodynamic scheme which considers two independent processes: pH-dependent formation of a membrane-competent form and its insertion into the lipid bilayer. Measurements of a model protein annexin B12 under conditions of lipid saturation demonstrate that protonation leading to the formation of the membrane-competent state occurs near membrane interface. Lipid titration experiments demonstrate that the free energy of transfer to the intermediate interfacial state is especially favorable, while the free energy of final insertion is modulated by interplay of hydrophobic and electrostatic interactions on the bilayer interface. The general principles of kinetic measurements along the insertion pathway containing interfacial intermediate are discussed and practical examples emphasizing appropriate fitting and normalization procedures are presented. PMID:21609856

Development and testing of the rack insertion device

NASA Technical Reports Server (NTRS)

Strickland, G. Scott

1995-01-01

Installing and removing experiment racks in a Space Station Logistics Module will become a repetitive operation at Kennedy Space Center (KSC) in the near future. A Rack Insertion Device (RID) consisting of an Extendible Boom, End Effector, and Positioning Base is being developed for the task. This paper discusses the key elements of the RlD's function and design. Prototype test results for the RlD's Extendible Boom and End Effector are presented. Also discussed are future end effectors that will further enhance the RlD's Space Station processing capability.

Tests with beam setup of the TileCal phase-II upgrade electronics

NASA Astrophysics Data System (ADS)

Reward Hlaluku, Dingane

2017-09-01

The LHC has planned a series of upgrades culminating in the High Luminosity LHC which will have an average luminosity 5-7 times larger than the nominal Run-2 value. The ATLAS Tile calorimeter plans to introduce a new readout architecture by completely replacing the back-end and front-end electronics for the High Luminosity LHC. The photomultiplier signals will be fully digitized and transferred for every bunch crossing to the off-detector Tile PreProcessor. The Tile PreProcessor will further provide preprocessed digital data to the first level of trigger with improved spatial granularity and energy resolution in contrast to the current analog trigger signals. A single super-drawer module commissioned with the phase-II upgrade electronics is to be inserted into the real detector to evaluate and qualify the new readout and trigger concepts in the overall ATLAS data acquisition system. This new super-drawer, so-called hybrid Demonstrator, must provide analog trigger signals for backward compatibility with the current system. This Demonstrator drawer has been inserted into a Tile calorimeter module prototype to evaluate the performance in the lab. In parallel, one more module has been instrumented with two other front-end electronics options based on custom ASICs (QIE and FATALIC) which are under evaluation. These two modules together with three other modules composed of the current system electronics were exposed to different particles and energies in three test-beam campaigns during 2015 and 2016.

Minor displacements in the insertion site provoke major differences in the induction of antibody responses by chimeric parvovirus-like particles.

PubMed

Rueda, P; Hurtado, A; del Barrio, M; Martínez-Torrecuadrada, J L; Kamstrup, S; Leclerc, C; Casal, J I

1999-10-10

An antigen-delivery system based on hybrid virus-like particles (VLPs) formed by the self-assembly of the capsid VP2 protein of canine parvovirus (CPV) and expressing foreign peptides was investigated. In this report, we have studied the effects of inserting the poliovirus C3:B epitope in the four loops and the C terminus of the CPV VP2 on the particle structure and immunogenicity. Epitope insertions in the four loops allowed the recovery of capsids in all of the mutants. However, only insertions of the C3:B epitope in VP2 residue 225 of the loop 2 were able to elicit a significant anti-peptide antibody response, but not poliovirus-neutralizing antibodies, probably because residue 225 is located in an small depression of the surface. To fine modulate the insertion site in loop 2, a cassette-mutagenesis was carried out to insert the epitope in adjacent positions 226, 227, and 228. The epitope C3:B inserted into these positions was well recognized by the specific monoclonal antibody C3 by immunoelectron microscopy. BALB/c mice immunized with these chimeric C3:B CPV:VLPs were able to elicit an strong neutralizing antibody response (>3 log(10) units) against poliovirus type 1 (Mahoney strain). Therefore, minor displacements in the insertion place cause dramatic changes in the accessibility of the epitope and the induction of antibody responses. Copyright 1999 Academic Press.

128×128 three-dimensional MEMS optical switch module with simultaneous optical path connection for optical cross-connect systems.

PubMed

Mizukami, Masato; Yamaguchi, Joji; Nemoto, Naru; Kawajiri, Yuko; Hirata, Hirooki; Uchiyama, Shingo; Makihara, Mitsuhiro; Sakata, Tomomi; Shimoyama, Nobuhiro; Oda, Kazuhiro

2011-07-20

A 128×128 three-dimensional MEMS optical switch module and a switching-control algorithm for high-speed connection and optical power stabilization are described. A prototype switch module enables the simultaneous switching of all optical paths. The insertion loss is less than 4.6 dB and is 2.3 dB on average. The switching time is less than 38 ms and is 8 ms on average. We confirmed that the maximum optical power can be obtained and optical power stabilization control is possible. The results confirm that the module is suitable for practical use in optical cross-connect systems. © 2011 Optical Society of America

Analysis, design, and experimental results for lightweight space heat receiver canisters, phase 1

NASA Technical Reports Server (NTRS)

Schneider, Michael G.; Brege, Mark A.; Heidenreich, Gary R.

1991-01-01

Critical technology experiments have been performed on thermal energy storage modules in support of the Brayton Advanced Heat Receiver program. The modules are wedge-shaped canisters designed to minimize the mechanical stresses that occur during the phase change of the lithium fluoride phase change material. Nickel foam inserts were used in some of the canisters to provide thermal conductivity enhancement and to distribute the void volume. Two canisters, one with a nickel foam insert, and one without, were thermally cycled in various orientations in a fluidized bed furnace. The only measurable impact of the nickel foam was seen when the back and short sides of the canister were insulated to simulate operation in the advanced receiver design. In tests with insulation, the furnace to back side delta T was larger in the canister with the nickel foam insert, probably due to the radiant absorptivity of the nickel. However, the differences in the temperature profiles of the two canisters were small, and in many cases the profiles matched fairly well. Computed Tomography (CT) was successfully used to nondestructively demarcate void locations in the canisters. Finally, canister dimensional stability, which was measured throughout the thermal cycling test program with an inspection fixture was satisfactory with a maximum change of 0.635 mm (0.025 in.).

Flow monitoring and control system for injection wells

DOEpatents

Corey, John C.

1993-01-01

A system for monitoring and controlling the injection rate of fluid by an injection well of an in-situ remediation system for treating a contaminated groundwater plume. The well is fitted with a gated insert, substantially coaxial with the injection well. A plurality of openings, some or all of which are equipped with fluid flow sensors and gates, are spaced along the insert. The gates and sensors are connected to a surface controller. The insert may extend throughout part of, or substantially the entire length of the injection well. Alternatively, the insert may comprise one or more movable modules which can be positioned wherever desired along the well. The gates are opened part-way at the start of treatment. The sensors monitor and display the flow rate of fluid passing through each opening on a controller. As treatment continues, the gates are opened to increase flow in regions of lesser flow, and closed to decrease flow in regions of greater flow, thereby approximately equalizing the amount of fluid reaching each part of the plume.

Flow monitoring and control system for injection wells

DOEpatents

Corey, J.C.

1993-02-16

A system for monitoring and controlling the injection rate of fluid by an injection well of an in-situ remediation system for treating a contaminated groundwater plume. The well is fitted with a gated insert, substantially coaxial with the injection well. A plurality of openings, some or all of which are equipped with fluid flow sensors and gates, are spaced along the insert. The gates and sensors are connected to a surface controller. The insert may extend throughout part of, or substantially the entire length of the injection well. Alternatively, the insert may comprise one or more movable modules which can be positioned wherever desired along the well. The gates are opened part-way at the start of treatment. The sensors monitor and display the flow rate of fluid passing through each opening on a controller. As treatment continues, the gates are opened to increase flow in regions of lesser flow, and closed to decrease flow in regions of greater flow, thereby approximately equalizing the amount of fluid reaching each part of the plume.

Horizontal modular dry irradiated fuel storage system

DOEpatents

Fischer, Larry E.; McInnes, Ian D.; Massey, John V.

1988-01-01

A horizontal, modular, dry, irradiated fuel storage system (10) includes a thin-walled canister (12) for containing irradiated fuel assemblies (20), which canister (12) can be positioned in a transfer cask (14) and transported in a horizontal manner from a fuel storage pool (18), to an intermediate-term storage facility. The storage system (10) includes a plurality of dry storage modules (26) which accept the canister (12) from the transfer cask (14) and provide for appropriate shielding about the canister (12). Each module (26) also provides for air cooling of the canister (12) to remove the decay heat of the irradiated fuel assemblies (20). The modules (26) can be interlocked so that each module (26) gains additional shielding from the next adjacent module (26). Hydraulic rams (30) are provided for inserting and removing the canisters (12) from the modules (26).

30/20 GHz spacecraft GaAs FET solid state transmitter for trunking and customer-premise-service application

NASA Technical Reports Server (NTRS)

Saunier, P.; Nelson, S.

1983-01-01

Sixteen 30 dB 0.5 W amplifier modules were combined to satisfy the requirement for a graceful degradation. If one module fails, the output power drops by only 0.43 dB. Also, by incorporating all the gain stages within the combiner the overall combining efficiency is maximized. A 16 way waveguide divider combiner was developed to minimize the insertion loss associated with such a large corporate feed structure. Tests showed that the 16 way insertion loss was less than 0.5 dB. To minimize loss, a direct transition from waveguide to microstrip, using a finline on duroid substrate, was developed. The FETs fabricated on MBE grown material, demonstrated superior performances. For example, a 600 micrometer device was capable of 320 mW output power with 5 dB gain and 26.6% efficiency at 21 GHz. The 16 module amplifier gave 8.95 W saturated output power with 30 dB gain. The overall efficiency was 9%. The 3 dB bandwidth was 2.5 GHz. At 17.7 GHz the amplifier had 5 W output power and at 20.2 GHz it still had 4.4 W.

Design and analysis of a tendon-based computed tomography-compatible robot with remote center of motion for lung biopsy.

PubMed

Yang, Yunpeng; Jiang, Shan; Yang, Zhiyong; Yuan, Wei; Dou, Huaisu; Wang, Wei; Zhang, Daguang; Bian, Yuan

2017-04-01

Nowadays, biopsy is a decisive method of lung cancer diagnosis, whereas lung biopsy is time-consuming, complex and inaccurate. So a computed tomography-compatible robot for rapid and precise lung biopsy is developed in this article. According to the actual operation process, the robot is divided into two modules: 4-degree-of-freedom position module for location of puncture point is appropriate for patient's almost all positions and 3-degree-of-freedom tendon-based orientation module with remote center of motion is compact and computed tomography-compatible to orientate and insert needle automatically inside computed tomography bore. The workspace of the robot surrounds patient's thorax, and the needle tip forms a cone under patient's skin. A new error model of the robot based on screw theory is proposed in view of structure error and actuation error, which are regarded as screw motions. Simulation is carried out to verify the precision of the error model contrasted with compensation via inverse kinematics. The results of insertion experiment on specific phantom prove the feasibility of the robot with mean error of 1.373 mm in laboratory environment, which is accurate enough to replace manual operation.

Toward a low-cost, low-power, low-complexity DAC-based multilevel (M-ary QAM) coherent transmitter using compact linear optical field modulator

NASA Astrophysics Data System (ADS)

Dingel, Benjamin

2017-01-01

In this invited paper, we summarize the current developments in linear optical field modulators (LOFMs) for coherent multilevel optical transmitters. Our focus is the presentation of a new, novel LOFM design that provides beneficial and necessary features such as lowest hardware component counts, lowered insertion loss, smaller RF power consumption, smaller footprint, simple structure, and lowered cost. We refer to this modulator as called Double-Pass LOFM (DP-LOFM) that becomes the building block for high-performance, linear Dual-Polarization, In-Phase- Quadrature-Phase (DP-IQ) modulator. We analyze its performance in term of slope linearity, and present one of its unique feature -- a built-in compensation functionality that no other linear modulators possessed till now.

CRISPR-Cas and Contact-Dependent Secretion Systems Present on Excisable Pathogenicity Islands with Conserved Recombination Modules.

PubMed

Carpenter, Megan R; Kalburge, Sai S; Borowski, Joseph D; Peters, Molly C; Colwell, Rita R; Boyd, E Fidelma

2017-05-15

Pathogenicity islands (PAIs) are mobile integrated genetic elements that contain a diverse range of virulence factors. PAIs integrate into the host chromosome at a tRNA locus that contains their specific bacterial attachment site, attB , via integrase-mediated site-specific recombination generating attL and attR sites. We identified conserved recombination modules (integrases and att sites) previously described in choleragenic Vibrio cholerae PAIs but with novel cargo genes. Clustered regularly interspaced short palindromic repeat (CRISPR)-associated proteins (Cas proteins) and a type VI secretion system (T6SS) gene cluster were identified at the Vibrio pathogenicity island 1 (VPI-1) insertion site in 19 V. cholerae strains and contained the same recombination module. Two divergent type I-F CRISPR-Cas systems were identified, which differed in Cas protein homology and content. The CRISPR repeat sequence was identical among all V. cholerae strains, but the CRISPR spacer sequences and the number of spacers varied. In silico analysis suggests that the CRISPR-Cas systems were active against phages and plasmids. A type III secretion system (T3SS) was present in 12 V. cholerae strains on a 68-kb island inserted at the same tRNA-serine insertion site as VPI-2 and contained the same recombination module. Bioinformatics analysis showed that two divergent T3SSs exist among the strains examined. Both the CRISPR and T3SS islands excised site specifically from the bacterial chromosome as complete units, and the cognate integrases were essential for this excision. These data demonstrated that identical recombination modules that catalyze integration and excision from the chromosome can acquire diverse cargo genes, signifying a novel method of acquisition for both CRISPR-Cas systems and T3SSs. IMPORTANCE This work demonstrated the presence of CRISPR-Cas systems and T3SSs on PAIs. Our work showed that similar recombination modules can associate with different cargo genes and catalyze their incorporation into bacterial chromosomes, which could convert a strain into a pathogen with very different disease pathologies. Each island had the ability to excise from the chromosome as distinct, complete units for possible transfer. Evolutionary analysis of these regions indicates that they were acquired by horizontal transfer and that PAIs are the units of transfer. Similar to the case for phage evolution, PAIs have a modular structure where different functional regions are acquired by identical recombination modules. Copyright © 2017 American Society for Microbiology.

Solid state electrochromic light modulator

DOEpatents

Cogan, Stuart F.; Rauh, R. David

1993-01-01

An all solid-state variable transmission electrochromic device has a source of charge compensating ions. An inorganic oxide counterelectrode film which on reduction with the accompanying insertion of the charge compensating ions increases its transmission of light of predetermined wavelength is separated from a primary electrochromic film which on reduction with the accompanying insertion of the charge compensating ions decreases its transmission of light of predetermined wavelength by an insulating electrolyte film that transports the charge compensating ions. First and second electrodes are contiguous with the inorganic oxide counter electrode film and the primary electrochromic film, respectively, and separated by the three films.

Solid state electrochromic light modulator

DOEpatents

Cogan, Stuart F.; Rauh, R. David

1993-12-07

An all solid-state variable transmission electrochromic device has a source of charge compensating ions. An inorganic oxide counterelectrode film which on reduction with the accompanying insertion of the charge compensating ions increases its transmission of light of predetermined wavelength is separated from a primary electrochromic film which on reduction with the accompanying insertion of the charge compensating ions decreases its transmission of light of predetermined wavelength by an insulating electrolyte film that transports the charge compensating ions. First and second electrodes are contiguous with the inorganic oxide counter electrode film and the primary electrochromic film, respectively, and separated by the three films.

Solid state electrochromic light modulator

DOEpatents

Cogan, Stuart F.; Rauh, R. David

1990-01-01

An all solid-state variable transmission electrochromic device has a source of charge compensating ions. An inorganic oxide counterelectrode film which on reduction with the accompanying insertion of the charge compensating ions increases its transmission of light of predetermined wavelength is separated from a primary electrochromic film which on reduction with the accompanying insertion of the charge compensating ions decreases its transmission of light of predetermined wavelength by an insulating electrolyte film that transports the charge compensating ions. First and second electrodes are contiguous with the inorganic oxide counter electrode film and the primary electrochromic film, respectively, and separated by the three films.

Solid state electrochromic light modulator

DOEpatents

Cogan, S.F.; Rauh, R.D.

1990-07-03

An all solid-state variable transmission electrochromic device has a source of charge compensating ions. An inorganic oxide counter electrode film which on reduction with the accompanying insertion of the charge compensating ions increases its transmission of light of predetermined wavelength is separated from a primary electrochromic film which on reduction with the accompanying insertion of the charge compensating ions decreases its transmission of light of predetermined wavelength by an insulating electrolyte film that transports the charge compensating ions. First and second electrodes are contiguous with the inorganic oxide counter electrode film and the primary electrochromic film, respectively, and separated by the three films. 4 figs.

FEL (free-electron lasers) undulator technology and synchrotron radiation source requirements

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

Robinson, K.; Quimby, D.; Slater, J.

This paper describes design and construction considerations of the THUNDER undulator, for use in free-electron laser experiments at visible wavelengths. For the parameters of these experiments, an unusually high degree of optimization of the electron-photon interaction is required and, as a result, THUNDER is built to especially high mechanical and magnetic precision. Except for its narrow magnet gap, the 5-meter THUNDER undulator is quite similar to insertion devices under consideration for the proposed 6-GeV storage ring. The engineering and physics approach adopted for this FEL modulator design is directly applicable to insertion device development. The tolerance limits to THUNDER, establishedmore » by modeling and design and achieved through careful control of mechanical and magnetic errors, are essential to the next generation of insertion devices.« less

Highly Sensitive Electro-Optic Modulators

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

DeVore, Peter S

2015-10-26

There are very important diagnostic and communication applications that receive faint electrical signals to be transmitted over long distances for capture. Optical links reduce bandwidth and distance restrictions of metal transmission lines; however, such signals are only weakly imprinted onto the optical carrier, resulting in low fidelity transmission. Increasing signal fidelity often necessitates insertion of radio-frequency (RF) amplifiers before the electro-optic modulator, but (especially at high frequencies) RF amplification results in large irreversible distortions. We have investigated the feasibility of a Sensitive and Linear Modulation by Optical Nonlinearity (SALMON) modulator to supersede RF-amplified modulators. SALMON uses cross-phase modulation, a manifestationmore » of the Kerr effect, to enhance the modulation depth of an RF-modulated optical wave. This ultrafast process has the potential to result in less irreversible distortions as compared to a RF-amplified modulator due to the broadband nature of the Kerr effect. Here, we prove that a SALMON modulator is a feasible alternative to an RFamplified modulator, by demonstrating a sensitivity enhancement factor greater than 20 and significantly reduced distortion.« less

Performance tradeoff between lateral and interdigitated doping patterns for high speed carrier-depletion based silicon modulators.

PubMed

Yu, Hui; Pantouvaki, Marianna; Van Campenhout, Joris; Korn, Dietmar; Komorowska, Katarzyna; Dumon, Pieter; Li, Yanlu; Verheyen, Peter; Absil, Philippe; Alloatti, Luca; Hillerkuss, David; Leuthold, Juerg; Baets, Roel; Bogaerts, Wim

2012-06-04

Carrier-depletion based silicon modulators with lateral and interdigitated PN junctions are compared systematically on the same fabrication platform. The interdigitated diode is shown to outperform the lateral diode in achieving a low VπLπ of 0.62 V∙cm with comparable propagation loss at the expense of a higher depletion capacitance. The low VπLπ of the interdigitated PN junction is employed to demonstrate 10 Gbit/s modulation with 7.5 dB extinction ration from a 500 µm long device whose static insertion loss is 2.8 dB. In addition, up to 40 Gbit/s modulation is demonstrated for a 3 mm long device comprising a lateral diode and a co-designed traveling wave electrode.

View of Africa and Madagascar from the Apollo 17 spacecraft

NASA Image and Video Library

1972-12-09

AS17-148-22717 (7 Dec. 1972) --- This view of a portion of Earth was taken from the Apollo 17 spacecraft following trans-lunar insertion during the final lunar landing mission in NASA's Apollo Program. The visible land mass is the southern two-thirds of the African continent, with Madagascar at right. A portion of Antarctica is visible at bottom frame. Onboard the Apollo 17 spacecraft were astronauts Eugene A. Cernan, commander; Ronald E. Evans, command module pilot; and Harrison H. Schmitt, lunar module pilot. While astronauts Cernan and Schmitt descended in the Lunar Module (LM) "Challenger" to explore the Hadley-Apennine region of the moon, astronaut Evans remained with the Command and Service Modules (CSM) "America" in lunar orbit.

LED module with high index lens

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

Bierhuizen, Serge J.; Wang, Nanze Patrick; Eng, Gregory W.

2016-07-05

An array of housings with housing bodies and lenses is molded, or an array of housing bodies is molded and bonded with lenses to form an array of housings with housing bodies and lenses. Light-emitting diodes (LEDs) are attached to the housings in the array. An array of metal pads may be bonded to the back of the array or insert molded with the housing array to form bond pads on the back of the housings. The array is singulated to form individual LED modules.

Skylab 2 Farewell View from the Departing Skylab Command/Service Module

NASA Image and Video Library

1973-06-22

SL2-07-667 (22 June 1973) --- This overhead view of the Skylab Space Station was taken from the Departing Skylab Command/Service Module during the Skylab 2's final fly-around inspection. The single solar panel is quite evident as well as the parasol solar shield, rigged to replace the missing micrometeoroid shield. Both the second solar panel and the micrometeoroid shield were torn away during a mishap in the original Skylab 1 liftoff and orbital insertion. Photo credit: NASA

Skylab 2 Farewell View from the Departing Skylab Command/Service Module

NASA Image and Video Library

1973-06-22

SL2-07-651 (22 June 1973) --- This overhead view of the Skylab Space Station was taken from the Departing Skylab Command/Service Module during the Skylab 2's final fly-around inspection. The single solar panel is quite evident as well as the parasol solar shield, rigged to replace the missing micrometeoroid shield. Both the second solar panel and the micrometeoroid shield were torn away during a mishap in the original Skylab 1 liftoff and orbital insertion. Photo credit: NASA

Environmental Containment Property Estimation Using QSARs in an Expert System

DTIC Science & Technology

1993-01-15

2 megabytes of memory (RAM), with 1000 kBytes of memory allocated for HyperCard. PEP overview The PEP system currently consists of four HyperCard...BCF Universel I ’ mI Figure 6. TSA module card from PEP The TSA module is also designed to accept files generated by other hardware/software... allocated to 1500 MB. * Installation of PEP PEP is typically shipped on one 3.5 inch 1.44 Megabyte floppy disk. To install PEP: 1. Insert the PEP disk into

SKYLAB (SL)-2 - LAUNCH - KSC

NASA Image and Video Library

1973-05-31

S73-27095 (25 May 1973) --- The Skylab 2 crew, consisting of astronauts Charles Conrad Jr., Joseph P. Kerwin and Paul J. Weitz, inside the command module atop a Saturn IB launch vehicle, heads toward the Skylab space station in Earth orbit. The command module was inserted into Earth orbit approximately 10 minutes after liftoff. The three represent the first of three crews who will spend record-setting durations for human beings in space, while performing a variety of experiments. Photo credit: NASA

SKYLAB (SL)-2 - LAUNCH - KSC

NASA Image and Video Library

1973-05-31

S73-27096 (25 May 1973) --- The Skylab 2 crew, consisting of astronauts Charles Conrad Jr., Joseph P. Kerwin and Paul J. Weitz, inside the command module atop a Saturn IB launch vehicle, heads toward the Skylab space station in Earth orbit. The command module was inserted into Earth orbit approximately 10 minutes after liftoff. The three represent the first of three crews who will spend record-setting durations for human beings in space, while performing a variety of experiments. Photo credit: NASA

Concept design of robotic modules for needlescopic surgery.

PubMed

Sen, Shin; Harada, Kanako; Hewitt, Zackary; Susilo, Ekawahyu; Kobayashi, Etsuko; Sakuma, Ichiro

2017-08-01

Many minimally invasive surgical procedures and assisting robotic systems have been developed to further minimize the number and size of incisions in the body surface. This paper presents a new idea combining the advantages of modular robotic surgery, single incision laparoscopic surgery and needlescopic surgery. In the proposed concept, modules carrying therapeutic or diagnostic tools are inserted in the abdominal cavity from the navel as in single incision laparoscopic surgery and assembled to 3-mm needle shafts penetrating the abdominal wall. A three degree-of-freedom robotic module measuring 16 mm in diameter and 51 mm in length was designed and prototyped. The performance of the three connected robotic modules was evaluated. A new idea of modular robotic surgery was proposed, and demonstrated by prototyping a 3-DOF robotic module. The performance of the connected robotic modules was evaluated, and the challenges and future work were summarized.

High Speed Terahertz Modulator on the Chip Based on Tunable Terahertz Slot Waveguide

PubMed Central

Singh, P. K.; Sonkusale, S.

2017-01-01

This paper presents an on-chip device that can perform gigahertz-rate amplitude modulation and switching of broadband terahertz electromagnetic waves. The operation of the device is based on the interaction of confined THz waves in a novel slot waveguide with an electronically tunable two dimensional electron gas (2DEG) that controls the loss of the THz wave propagating through this waveguide. A prototype device is fabricated which shows THz intensity modulation of 96% at 0.25 THz carrier frequency with low insertion loss and device length as small as 100 microns. The demonstrated modulation cutoff frequency exceeds 14 GHz indicating potential for the high-speed modulation of terahertz waves. The entire device operates at room temperature with low drive voltage (<2 V) and zero DC power consumption. The device architecture has potential for realization of the next generation of on-chip modulators and switches at THz frequencies. PMID:28102306

No-warp potted circuits

NASA Technical Reports Server (NTRS)

Robinson, W. W.

1979-01-01

Sponge inserts compensate for potting-compound expansion and relieve thermal stresses on circuit boards. Technique quality of production runs on PC boards intended for applications in environments less severe than those for aerospace equipment. Pads reduce weight of modules because they weigh far less than potting compound they displace.

Optimum Code Rates for Noncoherent MFSK with Errors and Erasures Decoding over Rayleigh Fading Channels

NASA Technical Reports Server (NTRS)

Ritcey, Adina Matache James A.

1997-01-01

In this paper, we analyze the performance of a communication system employing M-ary frequency shift keying (FSK) modulation with errors-and-erasures decoding using Viterbi ratio threshold technique for erasure insertion, in Rayleigh fading and AWGN channels.

Hydrophobic Residues near the Bilin Chromophore-Binding Pocket Modulate Spectral Tuning of Insert-Cys Subfamily Cyanobacteriochromes

PubMed Central

Cho, Sung Mi; Jeoung, Sae Chae; Song, Ji-Young; Song, Ji-Joon; Park, Youn-Il

2017-01-01

Cyanobacteriochromes (CBCRs) are a subfamily of phytochrome photoreceptors found exclusively in photosynthetic cyanobacteria. Four CBCRs containing a second Cys in the insert region (insert-Cys) have been identified from the nonheterocystous cyanobacterium Microcoleus B353 (Mbr3854g4 and Mbl3738g2) and the nitrogen fixing, heterocystous cyanobacterium Nostoc punctiforme (NpF2164g3 and NpR1597g2). These insert-Cys CBCRs can sense light in the near-UV to orange range, but key residues responsible for tuning their colour sensitivity have not been reported. In the present study, near-UV/Green (UG) photosensors Mbr3854g4 (UG1) and Mbl3738g2 (UG2) were chosen for further spectroscopic analysis of their spectral sensitivity and tuning. Consistent with most dual-Cys CBCRs, both UGs formed a second thioether linkage to the phycocyanobilin (PCB) chromophore via the insert-Cys. This bond is subject to breakage and relinkage during forward and reverse photoconversions. Variations in residues equivalent to Phe that are in close contact with the PCB chromophore D-ring in canonical red/green CBCRs are responsible for tuning the light absorption peaks of both dark and photoproducts. This is the first time these key residues that govern light absorption in insert-Cys family CBCRs have been identified and characterised. PMID:28094296

Uncovering the polymerase-induced cytotoxicity of an oxidized nucleotide

DOE PAGES

Freudenthal, Bret D.; Beard, William A.; Perera, Lalith; ...

2014-11-17

Oxidative stress promotes genomic instability and human diseases. A common oxidized nucleoside is 8-oxo-7,8-dihydro-2’-deoxyguanosine found both in DNA (8-oxo-G) and as a free nucleotide (8-oxo-dGTP). Nucleotide pools are especially vulnerable to oxidative damage. Therefore cells encode an enzyme (MutT/MTH1) that removes free oxidized nucleotides. This cleansing function is required for cancer cell survival and to modulate E. coli antibiotic sensitivity in a DNA polymerase (pol)-dependent manner. How polymerase discriminates between damaged and non-damaged nucleotides is not well understood. This analysis is essential given the role of oxidized nucleotides in mutagenesis, cancer therapeutics, and bacterial antibiotics. Even with cellular sanitizing activities,more » nucleotide pools contain enough 8-oxo-dGTP to promote mutagenesis. This arises from the dual coding potential where 8-oxo-dGTP(anti) base pairs with cytosine (Cy) and 8-oxodGTP(syn) utilizes its Hoogsteen edge to base pair with adenine (Ad). Here in this paper we utilized time-lapse crystallography to follow 8-oxo-dGTP insertion opposite Ad or Cy with human DNA pol β, to reveal that insertion is accommodated in either the syn- or anti-conformation, respectively. For 8-oxo-dGTP(anti) insertion, a novel divalent metal relieves repulsive interactions between the adducted guanine base and the triphosphate of the oxidized nucleotide. With either templating base, hydrogen bonding interactions between the bases are lost as the enzyme reopens after catalysis, leading to a cytotoxic nicked DNA repair intermediate. Combining structural snapshots with kinetic and computational analysis reveals how 8-oxodGTP utilizes charge modulation during insertion that can lead to a blocked DNA repair intermediate.« less

Uncovering the polymerase-induced cytotoxicity of an oxidized nucleotide

NASA Astrophysics Data System (ADS)

Freudenthal, Bret D.; Beard, William A.; Perera, Lalith; Shock, David D.; Kim, Taejin; Schlick, Tamar; Wilson, Samuel H.

2015-01-01

Oxidative stress promotes genomic instability and human diseases. A common oxidized nucleoside is 8-oxo-7,8-dihydro-2'-deoxyguanosine, which is found both in DNA (8-oxo-G) and as a free nucleotide (8-oxo-dGTP). Nucleotide pools are especially vulnerable to oxidative damage. Therefore cells encode an enzyme (MutT/MTH1) that removes free oxidized nucleotides. This cleansing function is required for cancer cell survival and to modulate Escherichia coli antibiotic sensitivity in a DNA polymerase (pol)-dependent manner. How polymerases discriminate between damaged and non-damaged nucleotides is not well understood. This analysis is essential given the role of oxidized nucleotides in mutagenesis, cancer therapeutics, and bacterial antibiotics. Even with cellular sanitizing activities, nucleotide pools contain enough 8-oxo-dGTP to promote mutagenesis. This arises from the dual coding potential where 8-oxo-dGTP(anti) base pairs with cytosine and 8-oxo-dGTP(syn) uses its Hoogsteen edge to base pair with adenine. Here we use time-lapse crystallography to follow 8-oxo-dGTP insertion opposite adenine or cytosine with human pol β, to reveal that insertion is accommodated in either the syn- or anti-conformation, respectively. For 8-oxo-dGTP(anti) insertion, a novel divalent metal relieves repulsive interactions between the adducted guanine base and the triphosphate of the oxidized nucleotide. With either templating base, hydrogen-bonding interactions between the bases are lost as the enzyme reopens after catalysis, leading to a cytotoxic nicked DNA repair intermediate. Combining structural snapshots with kinetic and computational analysis reveals how 8-oxo-dGTP uses charge modulation during insertion that can lead to a blocked DNA repair intermediate.

SU-F-J-205: Effect of Cone Beam Factor On Cone Beam CT Number Accuracy

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

Yao, W; Hua, C; Farr, J

Purpose: To examine the suitability of a Catphan™ 700 phantom for image quality QA of a cone beam computed tomography (CBCT) system deployed for proton therapy. Methods: Catphan phantoms, particularly Catphan™ 504, are commonly used in image quality QA for CBCT. As a newer product, Catphan™ 700 offers more tissue equivalent inserts which may be useful for generating the electron density – CT number curve for CBCT based treatment planning. The sensitometry-and-geometry module used in Catphan™ 700 is located at the end of the phantom and after the resolution line pair module. In Catphan™ 504 the line pair module ismore » located at the end of the phantom and after the sensitometry-and-geometry module. To investigate the effect of difference in location on CT number accuracy due to the cone beam factor, we scanned the Catphan™ 700 with the central plane of CBCT at the center of the phantom, line pair and sensitometry-andgeometry modules of the phantom, respectively. The protocol head and thorax scan modes were used. For each position, scans were repeated 4 times. Results: For the head scan mode, the standard deviation (SD) of the CT numbers of each insert under 4 repeated scans was up to 20 HU, 11 HU, and 11 HU, respectively, for the central plane of CBCT located at the center of the phantom, line pair, and sensitometry-and-geometry modules of the phantom. The mean of the SD was 9.9 HU, 5.7 HU, and 5.9 HU, respectively. For the thorax mode, the mean of the SD was 4.5 HU, 4.4 HU, and 4.4 HU, respectively. The assessment of image quality based on resolution and spatial linearity was not affected by imaging location changes. Conclusion: When the Catphan™ 700 was aligned to the center of imaging region, the CT number accuracy test may not meet expectations. We recommend reconfiguration of the modules.« less

Fluorophore Labeled Kinase Detects Ligands That Bind within the MAPK Insert of p38α Kinase

PubMed Central

Termathe, Martin; Grütter, Christian; Rabiller, Matthias; van Otterlo, Willem A. L.; Rauh, Daniel

2012-01-01

The vast majority of small molecules known to modulate kinase activity, target the highly conserved ATP-pocket. Consequently, such ligands are often less specific and in case of inhibitors, this leads to the inhibition of multiple kinases. Thus, selective modulation of kinase function remains a major hurdle. One of the next great challenges in kinase research is the identification of ligands which bind to less conserved sites and target the non-catalytic functions of protein kinases. However, approaches that allow for the unambiguous identification of molecules that bind to these less conserved sites are few in number. We have previously reported the use of fluorescent labels in kinases (FLiK) to develop direct kinase binding assays that exclusively detect ligands which stabilize inactive (DFG-out) kinase conformations. Here, we present the successful application of the FLiK approach to develop a high-throughput binding assay capable of directly monitoring ligand binding to a remote site within the MAPK insert of p38α mitogen-activated protein kinase (MAPK). Guided by the crystal structure of an initially identified hit molecule in complex with p38α, we developed a tight binding ligand which may serve as an ideal starting point for further investigations of the biological function of the MAPK insert in regulating the p38α signaling pathway. PMID:22768308

Optical modulation from an electro-optic polymer based hybrid Fabry-Perot etalon using transparent conducting oxides

NASA Astrophysics Data System (ADS)

Gan, Haiyong; Zhang, Hongxi; DeRose, Christopher T.; Norwood, Robert A.; Fallahi, Mahmoud; Luo, Jingdong; Jen, Alex K.-Y.; Liu, Boyang; Ho, Seng-Tiong; Peyghambarian, Nasser

2007-02-01

Fabry-Perot etalons using electro-optic (EO) organic materials can be used for devices such as tunable filters and spatial light modulators (SLM's) for wavelength division multiplexing (WDM) communication systems 1-5 and ultrafast imaging systems. For these applications the SLM's need to have: (i) low insertion loss, (ii) high speed operation, and (iii) large modulation depth with low drive voltage. Recently, there have been three developments which together can enhance the SLM performance to a higher level. First, low loss distributed Bragg reflector (DBR) mirrors are now used in SLM's to replace thin metal mirrors, resulting in reduced transmission loss, high reflectivity (>99%) and high finesse. Second, EO polymer materials have shown excellent properties for wide bandwidth optical modulation for information technology due to their fabrication flexibility, compatibility with high speed operation, and large EO coefficients at telecommunication wavelengths. For instance, the EO polymer AJL8/APC (AJL8: nonlinear optical chromophore, and APC: amorphous polycarbonate has recently been incorporated into waveguide modulators and achieved good performance for optical modulation. Finally, very low loss transparent conducting oxide (TCO) electrodes have drawn increasing attention for applications in optoelectronic devices. Here we will address how the low loss indium oxide (In IIO 3) electrodes with an absorption coefficient ~1000/cm and conductivity ~204 S/cm can help improve the modulation performance of EO polymer Fabry-Pérot étalons using the advanced electro-optic (EO) polymer material (AJL8/APC). A hybrid etalon structure with one highly conductive indium tin oxide (ITO) electrode outside the etalon cavity and one low-absorption In IIO 3 electrode inside etalon cavity has been demonstrated. High finesse (~234), improved effective applied voltage ratio (~0.25), and low insertion loss (~4 dB) have been obtained. A 10 dB isolation ratio and ~10% modulation depth at 200 kHz with only 5 V applied voltage have been achieved. These results indicate that such etalons are very promising candidates for ultrafast spatial light modulation in information technology.

Surface plasmons based terahertz modulator consisting of silicon-air-metal-dielectric-metal layers

NASA Astrophysics Data System (ADS)

Wang, Wei; Yang, Dongxiao; Qian, Zhenhai

2018-05-01

An optically controlled modulator of the terahertz wave, which is composed of a metal-dielectric-metal structure etched with circular loop arrays on both the metal layers and a photoexcited silicon wafer separated by an air layer, is proposed. Simulation results based on experimentally measured complex permittivities predict that modification of complex permittivity of the silicon wafer through excitation laser leads to a significant tuning of transmission characteristics of the modulator, forming the modulation depths of 59.62% and 96.64% based on localized surface plasmon peak and propagating surface plasmon peak, respectively. The influences of the complex permittivity of the silicon wafer and the thicknesses of both the air layer and the silicon wafer are numerically studied for better understanding the modulation mechanism. This study proposes a feasible methodology to design an optically controlled terahertz modulator with large modulation depth, high speed and suitable insertion loss, which is useful for terahertz applications in the future.

Functional cis-regulatory modules encoded by mouse-specific endogenous retrovirus

PubMed Central

Sundaram, Vasavi; Choudhary, Mayank N. K.; Pehrsson, Erica; Xing, Xiaoyun; Fiore, Christopher; Pandey, Manishi; Maricque, Brett; Udawatta, Methma; Ngo, Duc; Chen, Yujie; Paguntalan, Asia; Ray, Tammy; Hughes, Ava; Cohen, Barak A.; Wang, Ting

2017-01-01

Cis-regulatory modules contain multiple transcription factor (TF)-binding sites and integrate the effects of each TF to control gene expression in specific cellular contexts. Transposable elements (TEs) are uniquely equipped to deposit their regulatory sequences across a genome, which could also contain cis-regulatory modules that coordinate the control of multiple genes with the same regulatory logic. We provide the first evidence of mouse-specific TEs that encode a module of TF-binding sites in mouse embryonic stem cells (ESCs). The majority (77%) of the individual TEs tested exhibited enhancer activity in mouse ESCs. By mutating individual TF-binding sites within the TE, we identified a module of TF-binding motifs that cooperatively enhanced gene expression. Interestingly, we also observed the same motif module in the in silico constructed ancestral TE that also acted cooperatively to enhance gene expression. Our results suggest that ancestral TE insertions might have brought in cis-regulatory modules into the mouse genome. PMID:28348391

Improving Robotic Operator Performance Using Augmented Reality

NASA Technical Reports Server (NTRS)

Maida, James C.; Bowen, Charles K.; Pace, John W.

2007-01-01

The Special Purpose Dexterous Manipulator (SPDM) is a two-armed robot that functions as an extension to the end effector of the Space Station Robotics Manipulator System (SSRMS), currently in use on the International Space Station (ISS). Crew training for the SPDM is accomplished using a robotic hardware simulator, which performs most of SPDM functions under normal static Earth gravitational forces. Both the simulator and SPDM are controlled from a standard robotic workstation using a laptop for the user interface and three monitors for camera views. Most operations anticipated for the SPDM involve the manipulation, insertion, and removal of any of several types of Orbital Replaceable Unit (ORU), modules which control various ISS functions. Alignment tolerances for insertion of the ORU into its receptacle are 0.25 inch and 0.5 degree from nominal values. The pre-insertion alignment task must be performed within these tolerances by using available video camera views of the intrinsic features of the ORU and receptacle, without special registration markings. Since optimum camera views may not be available, and dynamic orbital lighting conditions may limit periods of viewing, a successful ORU insertion operation may require an extended period of time. This study explored the feasibility of using augmented reality (AR) to assist SPDM operations. Geometric graphical symbols were overlaid on one of the workstation monitors to afford cues to assist the operator in attaining adequate pre-insertion ORU alignment. Twelve skilled subjects performed eight ORU insertion tasks using the simulator with and without the AR symbols in a repeated measures experimental design. Results indicated that using the AR symbols reduced pre-insertion alignment error for all subjects and reduced the time to complete pre-insertion alignment for most subjects.

Reliability Technology to Achieve Insertion of Advanced Packaging (RELTECH) program

NASA Astrophysics Data System (ADS)

Fayette, Daniel F.; Speicher, Patricia; Stoklosa, Mark J.; Evans, Jillian V.; Evans, John W.; Gentile, Mike; Pagel, Chuck A.; Hakim, Edward

1993-08-01

A joint military-commercial effort to evaluate multichip module (MCM) structures is discussed. The program, Reliability Technology to Achieve Insertion of Advanced Packaging (RELTECH), has been designed to identify the failure mechanisms that are possible in MCM structures. The RELTECH test vehicles, technical assessment task, product evaluation plan, reliability modeling task, accelerated and environmental testing, and post-test physical analysis and failure analysis are described. The information obtained through RELTECH can be used to address standardization issues, through development of cost effective qualification and appropriate screening criteria, for inclusion into a commercial specification and the MIL-H-38534 general specification for hybrid microcircuits.

Reliability Technology to Achieve Insertion of Advanced Packaging (RELTECH) program

NASA Technical Reports Server (NTRS)

Fayette, Daniel F.; Speicher, Patricia; Stoklosa, Mark J.; Evans, Jillian V.; Evans, John W.; Gentile, Mike; Pagel, Chuck A.; Hakim, Edward

1993-01-01

A joint military-commercial effort to evaluate multichip module (MCM) structures is discussed. The program, Reliability Technology to Achieve Insertion of Advanced Packaging (RELTECH), has been designed to identify the failure mechanisms that are possible in MCM structures. The RELTECH test vehicles, technical assessment task, product evaluation plan, reliability modeling task, accelerated and environmental testing, and post-test physical analysis and failure analysis are described. The information obtained through RELTECH can be used to address standardization issues, through development of cost effective qualification and appropriate screening criteria, for inclusion into a commercial specification and the MIL-H-38534 general specification for hybrid microcircuits.

An improved nuclear magnetic resonance spectrometer

NASA Technical Reports Server (NTRS)

Elleman, D. D.; Manatt, S. L.

1967-01-01

Cylindrical sample container provides a high degree of nuclear stabilization to a nuclear magnetic resonance /nmr/ spectrometer. It is placed coaxially about the nmr insert and contains reference sample that gives a signal suitable for locking the field and frequency of an nmr spectrometer with a simple audio modulation system.

Development of PET/MRI with insertable PET for simultaneous PET and MR imaging of human brain.

PubMed

Jung, Jin Ho; Choi, Yong; Jung, Jiwoong; Kim, Sangsu; Lim, Hyun Keong; Im, Ki Chun; Oh, Chang Hyun; Park, Hyun-wook; Kim, Kyung Min; Kim, Jong Guk

2015-05-01

The purpose of this study was to develop a dual-modality positron emission tomography (PET)/magnetic resonance imaging (MRI) with insertable PET for simultaneous PET and MR imaging of the human brain. The PET detector block was composed of a 4 × 4 matrix of detector modules, each consisting of a 4 × 4 array LYSO coupled to a 4 × 4 Geiger-mode avalanche photodiode (GAPD) array. The PET insert consisted of 18 detector blocks, circularly mounted on a custom-made plastic base to form a ring with an inner diameter of 390 mm and axial length of 60 mm. The PET gantry was shielded with gold-plated conductive fabric tapes with a thickness of 0.1 mm. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuit. The flat cables were shielded with a mesh-type aluminum sheet with a thickness of 0.24 mm. The position decoder circuit and field programmable gate array-embedded DAQ modules were enclosed in an aluminum box with a thickness of 10 mm and located at the rear of the MR bore inside the MRI room. A 3-T human MRI system with a Larmor frequency of 123.7 MHz and inner bore diameter of 60 cm was used as the PET/MRI hybrid system. A custom-made radio frequency (RF) coil with an inner diameter of 25 cm was fabricated. The PET was positioned between gradient and the RF coils. PET performance was measured outside and inside the MRI scanner using echo planar imaging, spin echo, turbo spin echo, and gradient echo sequences. MRI performance was also evaluated with and without the PET insert. The stability of the newly developed PET insert was evaluated and simultaneous PET and MR images of a brain phantom were acquired. No significant degradation of the PET performance caused by MR was observed when the PET was operated using various MR imaging sequences. The signal-to-noise ratio of MR images was slightly degraded due to the PET insert installed inside the MR bore while the homogeneity was maintained. The change of gain of the 256 GAPD/scintillator elements of a detector block was <3% for 60 min, and simultaneous PET and MR images of a brain phantom were successfully acquired. Experimental results indicate that a compact and lightweight PET insert for hybrid PET/MRI can be developed using GAPD arrays and charge signal transmission method proposed in this study without significant interference.

Liquid Lens module with wide field-of-view and variable focal length

NASA Astrophysics Data System (ADS)

Seo, Sang Won; Han, Seungoh; Seo, Jun Ho; Choi, Woo Bum; Sung, Man Young

2010-12-01

A novel wide angle and variable-focus imaging module based on a miniaturized liquid lens is presented for capsule endoscopy applications. For these applications, it is desirable to have features such as a wide field of view (FOV), variable focus, small size, and low power consumption, thereby taking full advantage of the miniaturized liquid lens. The proposed imaging module has three aspheric plastic lenses for a wide FOV, and one liquid lens that can change the focal length by as much as 24.5 cm with a bias voltage difference of 23 Vrms for variable focusing. The assembled lens module has an overall length of 8.4 mm and a FOV of 120.5°. The realized imaging module including the proposed lenses is small enough to be inserted into a capsule endoscope, and it is expected to improve the diagnostic capability of capsule endoscopes.

A wideband software reconfigurable modem

NASA Astrophysics Data System (ADS)

Turner, J. H., Jr.; Vickers, H.

A wideband modem is described which provides signal processing capability for four Lx-band signals employing QPSK, MSK and PPM waveforms and employs a software reconfigurable architecture for maximum system flexibility and graceful degradation. The current processor uses a 2901 and two 8086 microprocessors per channel and performs acquisition, tracking, and data demodulation for JITDS, GPS, IFF and TACAN systems. The next generation processor will be implemented using a VHSIC chip set employing a programmable complex array vector processor module, a GP computer module, customized gate array modules, and a digital array correlator. This integrated processor has application to a wide number of diverse system waveforms, and will bring the benefits of VHSIC technology insertion into avionic antijam communications systems.

Laboratory racks are installed in the MPLM Leonardo

NASA Technical Reports Server (NTRS)

2000-01-01

In the Space Station Processing Facility, the Rack Insertion Unit lifts another laboratory rack to the Multi-Purpose Logistics Module Leonardo, in the background. The MPLM is the first of three such pressurized modules that will serve as the International Space Station's '''moving vans,''' carrying laboratory racks filled with equipment, experiments and supplies to and from the International Space Station aboard the Space Shuttle. Leonardo will be launched for the first time March 1, 2001, on Shuttle mission STS-102. On that flight, Leonardo will be filled with equipment and supplies to outfit the U.S. laboratory module, being carried to the ISS on the Jan. 19, 2001, launch of STS-98.

Novel insertion sequence- and transposon-mediated genetic rearrangements in genomic island SGI1 of Salmonella enterica serovar Kentucky.

PubMed

Doublet, Benoît; Praud, Karine; Bertrand, Sophie; Collard, Jean-Marc; Weill, François-Xavier; Cloeckaert, Axel

2008-10-01

Salmonella genomic island 1 (SGI1) is an integrative mobilizable element that harbors a multidrug resistance (MDR) gene cluster. Since its identification in epidemic Salmonella enterica serovar Typhimurium DT104 strains, variant SGI1 MDR gene clusters conferring different MDR phenotypes have been identified in several S. enterica serovars and classified as SGI1-A to -O. A study was undertaken to characterize SGI1 from serovar Kentucky strains isolated from travelers returning from Africa. Several strains tested were found to contain the partially characterized variant SGI1-K, recently described in a serovar Kentucky strain isolated in Australia. This variant contained only one cassette array, aac(3)-Id-aadA7, and an adjacent mercury resistance module. Here, the uncharacterized part of SGI1-K was sequenced. Downstream of the mer module similar to that found in Tn21, a mosaic genetic structure was found, comprising (i) part of Tn1721 containing the tetracycline resistance genes tetR and tet(A); (ii) part of Tn5393 containing the streptomycin resistance genes strAB, IS1133, and a truncated tnpR gene; and (iii) a Tn3-like region containing the tnpR gene and the beta-lactamase bla(TEM-1) gene flanked by two IS26 elements in opposite orientations. The rightmost IS26 element was shown to be inserted into the S044 open reading frame of the SGI1 backbone. This variant MDR region was named SGI1-K1 according to the previously described variant SGI1-K. Other SGI1-K MDR regions due to different IS26 locations, inversion, and partial deletions were characterized and named SGI1-K2 to -K5. Two new SGI1 variants named SGI1-P1 and -P2 contained only the Tn3-like region comprising the beta-lactamase bla(TEM-1) gene flanked by the two IS26 elements inserted into the SGI1 backbone. Three other new variants harbored only one IS26 element inserted in place of the MDR region of SGI1 and were named SGI1-Q1 to -Q3. Thus, in serovar Kentucky, the SGI1 MDR region undergoes recombinational and insertional events of transposon and insertion sequences, resulting in a higher diversity of MDR gene clusters than previously reported and consequently a higher diversity of MDR phenotypes.

Apollo experience report: Development of guidance targeting techniques for the command module and launch vehicle

NASA Technical Reports Server (NTRS)

Yencharis, J. D.; Wiley, R. F.; Davis, R. S.; Holmes, Q. A.; Zeiler, K. T.

1972-01-01

The development of the guidance targeting techniques for the Apollo command module and launch vehicle is discussed for four types of maneuvers: (1) translunar injection, (2) translunar midcourse, (3) lunar orbit insertion, and (4) return to earth. The development of real-time targeting programs for these maneuvers and the targeting procedures represented are discussed. The material is intended to convey historically the development of the targeting techniques required to meet the defined target objectives and to illustrate the solutions to problems encountered during that development.

Contributions to the UK Microwave Landing System Research and Development Programme 1974 to 1978. Volume 1.

DTIC Science & Technology

1979-05-01

the final element feed four-way modules. The typical insertion loss of a switch module is shown in Fig 3.18, this includes strip line and connector... losses . Isolation as a function of frequency is shown in Fig 3.19. C𔃾 uI CD Transmi r ter Jetai s The transmitter was housed in a trailer which was...VRPS). Theoretically this gives a lossless system. Practical imperfections introduced some loss , but this technique gave a much higher efficiency than

Gigascale Silicon Photonic Transmitters Integrating HBT-based Carrier-injection Electroabsorption Modulator Structures

NASA Astrophysics Data System (ADS)

Fu, Enjin

Demand for more bandwidth is rapidly increasing, which is driven by data intensive applications such as high-definition (HD) video streaming, cloud storage, and terascale computing applications. Next-generation high-performance computing systems require power efficient chip-to-chip and intra-chip interconnect yielding densities on the order of 1Tbps/cm2. The performance requirements of such system are the driving force behind the development of silicon integrated optical interconnect, providing a cost-effective solution for fully integrated optical interconnect systems on a single substrate. Compared to conventional electrical interconnect, optical interconnects have several advantages, including frequency independent insertion loss resulting in ultra wide bandwidth and link latency reduction. For high-speed optical transmitter modules, the optical modulator is a key component of the optical I/O channel. This thesis presents a silicon integrated optical transmitter module design based on a novel silicon HBT-based carrier injection electroabsorption modulator (EAM), which has the merits of wide optical bandwidth, high speed, low power, low drive voltage, small footprint, and high modulation efficiency. The structure, mechanism, and fabrication of the modulator structure will be discussed which is followed by the electrical modeling of the post-processed modulator device. The design and realization of a 10Gbps monolithic optical transmitter module integrating the driver circuit architecture and the HBT-based EAM device in a 130nm BiCMOS process is discussed. For high power efficiency, a 6Gbps ultra-low power driver IC implemented in a 130nm BiCMOS process is presented. The driver IC incorporates an integrated 27-1 pseudo-random bit sequence (PRBS) generator for reliable high-speed testing, and a driver circuit featuring digitally-tuned pre-emphasis signal strength. With outstanding drive capability, the driver module can be applied to a wide range of carrier injection modulators and light-emitting diodes (LED) with drive voltage requirements below 1.5V. Measurement results show an optical link based on a 70MHz red LED work well at 300Mbps by using the pre-emphasis driver module. A traveling wave electrode (TWE) modulator structure is presented, including a novel design methodology to address process limitations imposed by a commercial silicon fabrication technology. Results from 3D full wave EM simulation demonstrate the application of the design methodology to achieve specifications, including phase velocity matching, insertion loss, and impedance matching. Results show the HBT-based TWE-EAM system has the bandwidth higher than 60GHz.

Structural basis for the ATP-independent proteolytic activity of LonB proteases and reclassification of their AAA+ modules.

PubMed

An, Young Jun; Na, Jung-Hyun; Kim, Myung-Il; Cha, Sun-Shin

2015-10-01

Lon proteases degrade defective or denature proteins as well as some folded proteins for the control of cellular protein quality. There are two types of Lon proteases, LonA and LonB. Each consists of two functional components: a protease component and an ATPase associated with various cellular activities (AAA+ module). Here, we report the 2.03 -resolution crystal structure of the isolated AAA+ module (iAAA+ module) of LonB from Thermococcus onnurineus NA1 (TonLonB). The iAAA+ module, having no bound nucleotide, adopts a conformation virtually identical to the ADP-bound conformation of AAA+ modules in the hexameric structure of TonLonB; this provides insights into the ATP-independent proteolytic activity observed in a LonB protease. Structural comparison of AAA+ modules between LonA and LonB revealed that the AAA+ modules of Lon proteases are separated into two distinct clades depending on their structural features. The AAA+ module of LonB belongs to the -H2 & Ins1 insert clade (HINS clade)- defined for the first time in this study, while the AAA+ module of LonA is a member of the HCLR clade.

Apollo-Soyuz test project. Operations handbook command/service/docking modules (CSM 119/DM 1): Operational procedures reference issue

NASA Technical Reports Server (NTRS)

1974-01-01

Operational and configuration checks for the Apollo-Soyuz Test Project are presented. The checks include: backup crew prelaunch, prime crew prelaunch, boost and insertion, G and C reference data, G and N reference modes, rendezvous, navigation, Apollo-Soyuz operations, abort procedures, and emergency procedures.

Insertion of a pentacene layer into the gold/poly(methyl methacrylate)/heavily doped p-type Si/indium device leading to the modulation of resistive switching characteristics

NASA Astrophysics Data System (ADS)

Hung, Cheng-Chun; Lin, Yow-Jon

2018-01-01

In order to get a physical insight into the pentacene interlayer-modulated resistive switching (RS) characteristics, the Au/pentacene/poly(methyl methacrylate) (PMMA)/heavily doped p-type Si (p+-Si)/In and Au/PMMA/p+-Si/In devices are fabricated and the device performance is provided. The Au/pentacene/PMMA/p+-Si/In device shows RS behavior, whereas the Au/PMMA/p+-Si/In device exhibits the set/reset-free hysteresis current-voltage characteristics. The insertion of a pentacene layer is a noticeable contribution to the RS characteristic. This is because of the occurrence of carrier accumulation/depletion in the pentacene interlayer. The transition from carrier depletion to carrier accumulation (carrier accumulation to carrier depletion) in pentacene occurring under negative (positive) voltage induces the process of set (reset). The switching conduction mechanism is primarily described as space charge limited conduction according to the electrical transport properties measurement. The concept of a pentacene/PMMA heterostructure opens a promising direction for organic memory devices.

A panoramic view of the Space Station Processing Facility with Unity connecting module

NASA Technical Reports Server (NTRS)

1998-01-01

In this panoramic view of the Space Station Processing Facility (SSPF) can be seen (left to right) Unity connecting module, the Rack Insertion Device and the first Multi-Purpose Launch Module, the Leonardo. Windows at the right above Leonardo allow visitors on tour to watch the activities in the SSPF. The Unity, scheduled to be launched on STS-88 in December 1998, will be mated to the Russian-built Zarya control module which will already be in orbit. STS-88 will be the first Space Shuttle launch for the International Space Station. The Italian-built MPLM, scheduled to be launched on STS-100 on Dec. 2, 1999, will be carried in the payload bay of the Shuttle orbiter, and will provide storage and additional work space for up to two astronauts when docked to the International Space Station.

Method and apparatus for active control of combustion rate through modulation of heat transfer from the combustion chamber wall

DOEpatents

Roberts, Jr., Charles E.; Chadwell, Christopher J.

2004-09-21

The flame propagation rate resulting from a combustion event in the combustion chamber of an internal combustion engine is controlled by modulation of the heat transfer from the combustion flame to the combustion chamber walls. In one embodiment, heat transfer from the combustion flame to the combustion chamber walls is mechanically modulated by a movable member that is inserted into, or withdrawn from, the combustion chamber thereby changing the shape of the combustion chamber and the combustion chamber wall surface area. In another embodiment, heat transfer from the combustion flame to the combustion chamber walls is modulated by cooling the surface of a portion of the combustion chamber wall that is in close proximity to the area of the combustion chamber where flame speed control is desired.

Non-metallic dopant modulation of conductivity in substoichiometric tantalum pentoxide: A first-principles study

NASA Astrophysics Data System (ADS)

Bondi, Robert J.; Fox, Brian P.; Marinella, Matthew J.

2017-06-01

We apply density-functional theory calculations to predict dopant modulation of electrical conductivity (σo) for seven dopants (C, Si, Ge, H, F, N, and B) sampled at 18 quantum molecular dynamics configurations of five independent insertion sites into two (high/low) baseline references of σo in amorphous Ta2O5, where each reference contains a single, neutral O vacancy center (VO0). From this statistical population (n = 1260), we analyze defect levels, physical structure, and valence charge distributions to characterize nanoscale modification of the atomistic structure in local dopant neighborhoods. C is the most effective dopant at lowering Ta2Ox σo, while also exhibiting an amphoteric doping behavior by either donating or accepting charge depending on the host oxide matrix. Both B and F robustly increase Ta2Ox σo, although F does so through elimination of Ta high charge outliers, while B insertion conversely creates high charge O outliers through favorable BO3 group formation, especially in the low σo reference. While N applications to dope and passivate oxides are prevalent, we found that N exacerbates the stochasticity of σo we sought to mitigate; sensitivity to the N insertion site and some propensity to form N-O bond chemistries appear responsible. We use direct first-principles predictions of σo to explore feasible Ta2O5 dopants to engineer improved oxides with lower variance and greater repeatability to advance the manufacturability of resistive memory technologies.

ITER CS Model Coil and CS Insert Test Results

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

Martovetsky, N; Michael, P; Minervina, J

2000-09-07

The Inner and Outer modules of the Central Solenoid Model Coil (CSMC) were built by US and Japanese home teams in collaboration with European and Russian teams to demonstrate the feasibility of a superconducting Central Solenoid for ITER and other large tokamak reactors. The CSMC mass is about 120 t, OD is about 3.6 m and the stored energy is 640 MJ at 46 kA and peak field of 13 T. Testing of the CSMC and the CS Insert took place at Japan Atomic Energy Research Institute (JAERI) from mid March until mid August 2000. This paper presents the mainmore » results of the tests performed.« less

Streamlining recombination-mediated genetic engineering by validating three neutral integration sites in Synechococcus sp. PCC 7002.

PubMed

Vogel, Anne Ilse Maria; Lale, Rahmi; Hohmann-Marriott, Martin Frank

2017-01-01

Synechococcus sp. PCC 7002 (henceforth Synechococcus ) is developing into a powerful synthetic biology chassis. In order to streamline the integration of genes into the Synechococcus chromosome, validation of neutral integration sites with optimization of the DNA transformation protocol parameters is necessary. Availability of BioBrick-compatible integration modules is desirable to further simplifying chromosomal integrations. We designed three BioBrick-compatible genetic modules, each targeting a separate neutral integration site, A2842, A0935, and A0159, with varying length of homologous region, spanning from 100 to 800 nt. The performance of the different modules for achieving DNA integration were tested. Our results demonstrate that 100 nt homologous regions are sufficient for inserting a 1 kb DNA fragment into the Synechococcus chromosome. By adapting a transformation protocol from a related cyanobacterium, we shortened the transformation procedure for Synechococcus significantly. The optimized transformation protocol reported in this study provides an efficient way to perform genetic engineering in Synechococcus . We demonstrated that homologous regions of 100 nt are sufficient for inserting a 1 kb DNA fragment into the three tested neutral integration sites. Integration at A2842, A0935 and A0159 results in only a minimal fitness cost for the chassis. This study contributes to developing Synechococcus as the prominent chassis for future synthetic biology applications.

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

Plautz, Tia E.; Johnson, R. P.; Sadrozinski, H. F.-W.

Purpose: To characterize the modulation transfer function (MTF) of the pre-clinical (phase II) head scanner developed for proton computed tomography (pCT) by the pCT collaboration. To evaluate the spatial resolution achievable by this system. Methods: Our phase II proton CT scanner prototype consists of two silicon telescopes that track individual protons upstream and downstream from a phantom, and a 5-stage scintillation detector that measures a combination of the residual energy and range of the proton. Residual energy is converted to water equivalent path length (WEPL) of the protons in the scanned object. The set of WEPL values and associated pathsmore » of protons passing through the object over a 360° angular scan is processed by an iterative parallelizable reconstruction algorithm that runs on GP-GPU hardware. A custom edge phantom composed of water-equivalent polymer and tissue-equivalent material inserts was constructed. The phantom was first simulated in Geant4 and then built to perform experimental beam tests with 200 MeV protons at the Northwestern Medicine Chicago Proton Center. The oversampling method was used to construct radial and azimuthal edge spread functions and modulation transfer functions. The spatial resolution was defined by the 10% point of the modulation transfer function in units of lp/cm. Results: The spatial resolution of the image was found to be strongly correlated with the radial position of the insert but independent of the relative stopping power of the insert. The spatial resolution varies between roughly 4 and 6 lp/cm in both the the radial and azimuthal directions depending on the radial displacement of the edge. Conclusion: The amount of image degradation due to our detector system is small compared with the effects of multiple Coulomb scattering, pixelation of the image and the reconstruction algorithm. Improvements in reconstruction will be made in order to achieve the theoretical limits of spatial resolution.« less

A compact high resolution flat panel PET detector based on the new 4-side buttable MPPC for biomedical applications.

PubMed

Wang, Qiang; Wen, Jie; Ravindranath, Bosky; O'Sullivan, Andrew W; Catherall, David; Li, Ke; Wei, Shouyi; Komarov, Sergey; Tai, Yuan-Chuan

2015-09-11

Compact high-resolution panel detectors using virtual pinhole (VP) PET geometry can be inserted into existing clinical or pre-clinical PET systems to improve regional spatial resolution and sensitivity. Here we describe a compact panel PET detector built using the new Though Silicon Via (TSV) multi-pixel photon counters (MPPC) detector. This insert provides high spatial resolution and good timing performance for multiple bio-medical applications. Because the TSV MPPC design eliminates wire bonding and has a package dimension which is very close to the MPPC's active area, it is 4-side buttable. The custom designed MPPC array (based on Hamamatsu S12641-PA-50(x)) used in the prototype is composed of 4 × 4 TSV-MPPC cells with a 4.46 mm pitch in both directions. The detector module has 16 × 16 lutetium yttrium oxyorthosilicate (LYSO) crystal array, with each crystal measuring 0.92 × 0.92 × 3 mm 3 with 1.0 mm pitch. The outer diameter of the detector block is 16.8 × 16.8 mm 2 . Thirty-two such blocks will be arranged in a 4 × 8 array with 1 mm gaps to form a panel detector with detection area around 7 cm × 14 cm in the full-size detector. The flood histogram acquired with Ge-68 source showed excellent crystal separation capability with all 256 crystals clearly resolved. The detector module's mean, standard deviation, minimum (best) and maximum (worst) energy resolution were 10.19%, +/-0.68%, 8.36% and 13.45% FWHM, respectively. The measured coincidence time resolution between the block detector and a fast reference detector (around 200 ps single photon timing resolution) was 0.95 ns. When tested with Siemens Cardinal electronics the performance of the detector blocks remain consistent. These results demonstrate that the TSV-MPPC is a promising photon sensor for use in a flat panel PET insert composed of many high resolution compact detector modules.

Quick-release connector module

NASA Technical Reports Server (NTRS)

Sedig, Albert R. (Inventor)

1995-01-01

A multi-bay electrical connector is described, of the type that has a frame (12, FIG. 2 ) with cavities (14) that each holds a separate module 20, which enables quick withdrawal of a single module from the frame and its quick replacement. A lock arm (42) is slidable along a first side (50) of a first cavity, and has at least one lock lug (80). A first module has a barrier part (70) that lies inward of the lock lug, which prevents outward movement of the first module out of the frame cavity. The lock arm can be moved to an unlocked position wherein the barrier part on the module lies inward of a gap (84) in the lock arm to permit the module to be pulled out of the frame cavity and later inserted therein. A latch (54) is slidable on the frame in directions (A, B) perpendicular to the sliding movement of the lock arm, and has an abutment (112, FIG. 5 ) that abuts a shoulder (114) on the lock arm to keep the lock arm in its unlocked position until the latch is released.

MMIC linear-phase and digital modulators for deep space spacecraft X-band transponder applications

NASA Technical Reports Server (NTRS)

Mysoor, Narayan R.; Ali, Fazal

1991-01-01

The design concepts, analyses, and development of GaAs monolithic microwave integrated circuit (MMIC) linear-phase and digital modulators for the next generation of space-borne communications systems are summarized. The design approach uses a compact lumped element quadrature hybrid and Metal Semiconductor Field Effect Transistors (MESFET)-varactors to provide low loss and well-controlled phase performance for deep space transponder (DST) applications. The measured results of the MESFET-diode show a capacitance range of 2:1 under reverse bias, and a Q of 38 at 10 GHz. Three cascaded sections of hybrid-coupled reflection phase shifters were modeled and simulations performed to provide an X-band (8415 +/- 50 MHz) DST phase modulator with +/- 2.5 radians of peak phase deviation. The modulator will accommodate downlink signal modulation with composite telemetry and ranging data, with a deviation linearity tolerance of +/- 8 percent and insertion loss of less than 8 +/- 0.5 dB. The MMIC digital modulator is designed to provide greater than 10 Mb/s of bi-phase modulation at X-band.

Synchronization for Optical PPM with Inter-Symbol Guard Times

NASA Astrophysics Data System (ADS)

Rogalin, R.; Srinivasan, M.

2017-05-01

Deep space optical communications promises orders of magnitude growth in communication capacity, supporting high data rate applications such as video streaming and high-bandwidth science instruments. Pulse position modulation is the modulation format of choice for deep space applications, and by inserting inter-symbol guard times between the symbols, the signal carries the timing information needed by the demodulator. Accurately extracting this timing information is crucial to demodulating and decoding this signal. In this article, we propose a number of timing and frequency estimation schemes for this modulation format, and in particular highlight a low complexity maximum likelihood timing estimator that significantly outperforms the prior art in this domain. This method does not require an explicit synchronization sequence, freeing up channel resources for data transmission.

Silicon photonics plasma-modulators with advanced transmission line design.

PubMed

Merget, Florian; Azadeh, Saeed Sharif; Mueller, Juliana; Shen, Bin; Nezhad, Maziar P; Hauck, Johannes; Witzens, Jeremy

2013-08-26

We have investigated two novel concepts for the design of transmission lines in travelling wave Mach-Zehnder interferometer based Silicon Photonics depletion modulators overcoming the analog bandwidth limitations arising from cross-talk between signal lines in push-pull modulators and reducing the linear losses of the transmission lines. We experimentally validate the concepts and demonstrate an E/O -3 dBe bandwidth of 16 GHz with a 4V drive voltage (in dual drive configuration) and 8.8 dB on-chip insertion losses. Significant bandwidth improvements result from suppression of cross-talk. An additional bandwidth enhancement of ~11% results from a reduction of resistive transmission line losses. Frequency dependent loss models for loaded transmission lines and E/O bandwidth modeling are fully verified.

Design of a compact high-speed optical modulator based on a hybrid plasmonic nanobeam cavity

NASA Astrophysics Data System (ADS)

Javid, Mohammad Reza; Miri, Mehdi; Zarifkar, Abbas

2018-03-01

A hybrid plasmonic electro-optic modulator based on a polymer-filled one dimensional photonic crystal nanobeam (1D PhCNB) cavity is proposed here. In the proposed structure the optical intensity modulation is realized by shifting the resonant wavelength of the cavity through electrically tuning the refractive index of the electro-optic polymer in the hybrid plasmonic waveguide. As a result of the subwavelength light confinement in the hybrid plasmonic waveguide and the compact footprint of the 1D PhCNB cavity, the designed modulator has the small overall footprint of 3 . 6 μm2 and the required wavelength shift can be achieved by applying very small actuating power. Three dimensional finite-difference time-domain (3D-FDTD) simulations show that the modulation depth of 10.9 dB, and insertion loss of 1.14 dB, along with very high modulation speed of 224 GHz can be achieved in the proposed modulator with very low modulation energy of 0.75 fJ/bit. A comparison between the performance parameters of the proposed modulator and those of previously reported PhCNB based modulators reveals the superior performance of the proposed structure in terms of modulation speed, energy consumption and overall footprint.

Development of an 83.2 MHz, 3.2 kW solid-state RF amplifier using Wilkinson power divider and combiner for a 10 MeV cyclotron

NASA Astrophysics Data System (ADS)

Song, Ho Seung; Ghergherehchi, Mitra; Oh, Seyoung; Chai, Jong Seo

2017-03-01

We design a stripline-type Wilkinson power divider and combiner for a 3.2 kW solid-state radio frequency (RF) amplifier module and optimize this setup. A Teflon-based printed circuit board is used in the power combiner to transmit high RF power efficiently in the limited space. The reflection coefficient (S11) and insertion loss (S21) related to impedance matching are characterized to determine the optimization process. The resulting two-way divider reflection coefficient and insertion loss were -48.00 dB and -3.22 dB, respectively. The two-way power combiner reflection coefficient and insertion loss were -20 dB and -3.3 dB, respectively. Moreover, the 3.2 kW solid-state RF power test results demonstrate that the proposed power divider and combiner exhibit a maximum efficiency value of 71.3% (combiner loss 5%) at 48 V supply voltage.

Endogenous Retrovirus EAV-HP Linked to Blue Egg Phenotype in Mapuche Fowl

PubMed Central

Alcalde, José A.; Wang, Chen; Han, Jian-Lin; Gongora, Jaime; Gourichon, David; Tixier-Boichard, Michèle; Hanotte, Olivier

2013-01-01

Oocyan or blue/green eggshell colour is an autosomal dominant trait found in native chickens (Mapuche fowl) of Chile and in some of their descendants in European and North American modern breeds. We report here the identification of an endogenous avian retroviral (EAV-HP) insertion in oocyan Mapuche fowl and European breeds. Sequencing data reveals 100% retroviral identity between the Mapuche and European insertions. Quantitative real-time PCR analysis of European oocyan chicken indicates over-expression of the SLCO1B3 gene (P<0.05) in the shell gland and oviduct. Predicted transcription factor binding sites in the long terminal repeats (LTR) indicate AhR/Ar, a modulator of oestrogen, as a possible promoter/enhancer leading to reproductive tissue-specific over-expression of the SLCO1B3 gene. Analysis of all jungle fowl species Gallus sp. supports the retroviral insertion to be a post-domestication event, while identical LTR sequences within domestic chickens are in agreement with a recent de novo mutation. PMID:23990950

Endogenous retrovirus EAV-HP linked to blue egg phenotype in Mapuche fowl.

PubMed

Wragg, David; Mwacharo, Joram M; Alcalde, José A; Wang, Chen; Han, Jian-Lin; Gongora, Jaime; Gourichon, David; Tixier-Boichard, Michèle; Hanotte, Olivier

2013-01-01

Oocyan or blue/green eggshell colour is an autosomal dominant trait found in native chickens (Mapuche fowl) of Chile and in some of their descendants in European and North American modern breeds. We report here the identification of an endogenous avian retroviral (EAV-HP) insertion in oocyan Mapuche fowl and European breeds. Sequencing data reveals 100% retroviral identity between the Mapuche and European insertions. Quantitative real-time PCR analysis of European oocyan chicken indicates over-expression of the SLCO1B3 gene (P<0.05) in the shell gland and oviduct. Predicted transcription factor binding sites in the long terminal repeats (LTR) indicate AhR/Ar, a modulator of oestrogen, as a possible promoter/enhancer leading to reproductive tissue-specific over-expression of the SLCO1B3 gene. Analysis of all jungle fowl species Gallus sp. supports the retroviral insertion to be a post-domestication event, while identical LTR sequences within domestic chickens are in agreement with a recent de novo mutation.

Chitosan/alginate complexes for vaginal delivery of chlorhexidine digluconate.

PubMed

Abruzzo, A; Bigucci, F; Cerchiara, T; Saladini, B; Gallucci, M C; Cruciani, F; Vitali, B; Luppi, B

2013-01-16

Chitosan/alginate complexes were prepared at different polycation/polyanion molar ratios and freeze-dried vaginal inserts were obtained for chlorhexidine digluconate local delivery in genital infections. Complex yield, FT-IR spectra, and TGA thermograms were studied to confirm the interaction between the two polyions. The influence of different complexes on physical handling, morphology, and drug distribution in the samples were evaluated by friability test, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS), respectively. In vitro water-uptake, mucoadhesion and release tests were performed as well as microbiological tests toward pathogenic vaginal microorganisms. The results showed that the selection of suitable chitosan/alginate molar ratio and drug loading allowed modulate insert ability to hydrate, adhere to the mucosa, and release chlorhexidine digluconate. The insert containing an excess of alginate was found to be the best performing formulation and showed good antimicrobial activity toward the pathogens Candida albicans and Escherichia coli. Copyright © 2012 Elsevier Ltd. All rights reserved.

The change of radial power factor distribution due to RCCA insertion at the first cycle core of AP1000

NASA Astrophysics Data System (ADS)

Susilo, J.; Suparlina, L.; Deswandri; Sunaryo, G. R.

2018-02-01

The using of a computer program for the PWR type core neutronic design parameters analysis has been carried out in some previous studies. These studies included a computer code validation on the neutronic parameters data values resulted from measurements and benchmarking calculation. In this study, the AP1000 first cycle core radial power peaking factor validation and analysis were performed using CITATION module of the SRAC2006 computer code. The computer code has been also validated with a good result to the criticality values of VERA benchmark core. The AP1000 core power distribution calculation has been done in two-dimensional X-Y geometry through ¼ section modeling. The purpose of this research is to determine the accuracy of the SRAC2006 code, and also the safety performance of the AP1000 core first cycle operating. The core calculations were carried out with the several conditions, those are without Rod Cluster Control Assembly (RCCA), by insertion of a single RCCA (AO, M1, M2, MA, MB, MC, MD) and multiple insertion RCCA (MA + MB, MA + MB + MC, MA + MB + MC + MD, and MA + MB + MC + MD + M1). The maximum power factor of the fuel rods value in the fuel assembly assumedapproximately 1.406. The calculation results analysis showed that the 2-dimensional CITATION module of SRAC2006 code is accurate in AP1000 power distribution calculation without RCCA and with MA+MB RCCA insertion.The power peaking factor on the first operating cycle of the AP1000 core without RCCA, as well as with single and multiple RCCA are still below in the safety limit values (less then about 1.798). So in terms of thermal power generated by the fuel assembly, then it can be considered that the AP100 core at the first operating cycle is safe.

Development of PET/MRI with insertable PET for simultaneous PET and MR imaging of human brain

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

Jung, Jin Ho; Choi, Yong, E-mail: ychoi.image@gmail.com; Jung, Jiwoong

2015-05-15

Purpose: The purpose of this study was to develop a dual-modality positron emission tomography (PET)/magnetic resonance imaging (MRI) with insertable PET for simultaneous PET and MR imaging of the human brain. Methods: The PET detector block was composed of a 4 × 4 matrix of detector modules, each consisting of a 4 × 4 array LYSO coupled to a 4 × 4 Geiger-mode avalanche photodiode (GAPD) array. The PET insert consisted of 18 detector blocks, circularly mounted on a custom-made plastic base to form a ring with an inner diameter of 390 mm and axial length of 60 mm. Themore » PET gantry was shielded with gold-plated conductive fabric tapes with a thickness of 0.1 mm. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuit. The flat cables were shielded with a mesh-type aluminum sheet with a thickness of 0.24 mm. The position decoder circuit and field programmable gate array-embedded DAQ modules were enclosed in an aluminum box with a thickness of 10 mm and located at the rear of the MR bore inside the MRI room. A 3-T human MRI system with a Larmor frequency of 123.7 MHz and inner bore diameter of 60 cm was used as the PET/MRI hybrid system. A custom-made radio frequency (RF) coil with an inner diameter of 25 cm was fabricated. The PET was positioned between gradient and the RF coils. PET performance was measured outside and inside the MRI scanner using echo planar imaging, spin echo, turbo spin echo, and gradient echo sequences. MRI performance was also evaluated with and without the PET insert. The stability of the newly developed PET insert was evaluated and simultaneous PET and MR images of a brain phantom were acquired. Results: No significant degradation of the PET performance caused by MR was observed when the PET was operated using various MR imaging sequences. The signal-to-noise ratio of MR images was slightly degraded due to the PET insert installed inside the MR bore while the homogeneity was maintained. The change of gain of the 256 GAPD/scintillator elements of a detector block was <3% for 60 min, and simultaneous PET and MR images of a brain phantom were successfully acquired. Conclusions: Experimental results indicate that a compact and lightweight PET insert for hybrid PET/MRI can be developed using GAPD arrays and charge signal transmission method proposed in this study without significant interference.« less

Advanced Plant Experiment, APEX-4

NASA Image and Video Library

2017-03-10

Advanced Plant Experiment, APEX-4, support in the Telescience Support Center at NASA Glenn. APEX-4 continues a highly successful investigation into the effects of microgravity on the development of roots and cells on plant seedlings. After four days of growth, the petri plate will be inserted into the Fluids Integrated Rack (FIR) Light Microscopy Module (LMM) facility for detailed imaging.

Phase modulation in horizontal metal-insulator-silicon-insulator-metal plasmonic waveguides.

PubMed

Zhu, Shiyang; Lo, G Q; Kwong, D L

2013-04-08

An extremely compact Si phase modulator is proposed and validated, which relies on effective modulation of the real part of modal index of horizontal metal-insulator-Si-insulator-metal plasmonic waveguides by a voltage applied between the metal cover and the Si core. Proof-of-concept devices are fabricated on silicon-on-insulator substrates using standard complementary metal-oxide-semiconductor technology using copper as the metal and thermal silicon dioxide as the insulator. A modulator with a 1-μm-long phase shifter inserted in an asymmetric Si Mach-Zehnder interferometer exhibits 9-dB extinction ratio under a 6-V/10-kHz voltage swing. Numerical simulations suggest that high speed and low driving voltage could be achieved by shortening the distance between the Si core and the n(+)-contact and by using a high-κ dielectric as the insulator, respectively.

Flip-chip integrated silicon Mach-Zehnder modulator with a 28nm fully depleted silicon-on-insulator CMOS driver.

PubMed

Yong, Zheng; Shopov, Stefan; Mikkelsen, Jared C; Mallard, Robert; Mak, Jason C C; Voinigescu, Sorin P; Poon, Joyce K S

2017-03-20

We present a silicon electro-optic transmitter consisting of a 28nm ultra-thin body and buried oxide fully depleted silicon-on-insulator (UTBB FD-SOI) CMOS driver flip-chip integrated onto a Mach-Zehnder modulator. The Mach-Zehnder silicon optical modulator was optimized to have a 3dB bandwidth of around 25 GHz at -1V bias and a 50 Ω impedance. The UTBB FD-SOI CMOS driver provided a large output voltage swing around 5 V_pp to enable a high dynamic extinction ratio and a low device insertion loss. At 44 Gbps, the transmitter achieved a high extinction ratio of 6.4 dB at the modulator quadrature operation point. This result shows open eye diagrams at the highest bit rates and with the largest extinction ratios for silicon electro-optic transmitter using a CMOS driver.

Ring modulators with enhanced efficiency based on standing-wave operation on a field-matched, interdigitated p-n junction.

PubMed

Pavanello, Fabio; Zeng, Xiaoge; Wade, Mark T; Popović, Miloš A

2016-11-28

We propose ring modulators based on interdigitated p-n junctions that exploit standing rather than traveling-wave resonant modes to improve modulation efficiency, insertion loss and speed. Matching the longitudinal nodes and antinodes of a standing-wave mode with high (contacts) and low (depletion regions) carrier density regions, respectively, simultaneously lowers loss and increases sensitivity significantly. This approach permits further to relax optical constraints on contacts placement and can lead to lower device capacitance. Such structures are well-matched to fabrication in advanced microelectronics CMOS processes. Device architectures that exploit this concept are presented along with their benefits and drawbacks. A temporal coupled mode theory model is used to investigate the static and dynamic response. We show that modulation efficiencies or loss Q factors up to 2 times higher than in previous traveling-wave geometries can be achieved leading to much larger extinction ratios. Finally, we discuss more complex doping geometries that can improve carrier dynamics for higher modulation speeds in this context.

NOTE: An innovative phantom for quantitative and qualitative investigation of advanced x-ray imaging technologies

NASA Astrophysics Data System (ADS)

Chiarot, C. B.; Siewerdsen, J. H.; Haycocks, T.; Moseley, D. J.; Jaffray, D. A.

2005-11-01

Development, characterization, and quality assurance of advanced x-ray imaging technologies require phantoms that are quantitative and well suited to such modalities. This note reports on the design, construction, and use of an innovative phantom developed for advanced imaging technologies (e.g., multi-detector CT and the numerous applications of flat-panel detectors in dual-energy imaging, tomosynthesis, and cone-beam CT) in diagnostic and image-guided procedures. The design addresses shortcomings of existing phantoms by incorporating criteria satisfied by no other single phantom: (1) inserts are fully 3D—spherically symmetric rather than cylindrical; (2) modules are quantitative, presenting objects of known size and contrast for quality assurance and image quality investigation; (3) features are incorporated in ideal and semi-realistic (anthropomorphic) contexts; and (4) the phantom allows devices to be inserted and manipulated in an accessible module (right lung). The phantom consists of five primary modules: (1) head, featuring contrast-detail spheres approximate to brain lesions; (2) left lung, featuring contrast-detail spheres approximate to lung modules; (3) right lung, an accessible hull in which devices may be placed and manipulated; (4) liver, featuring conrast-detail spheres approximate to metastases; and (5) abdomen/pelvis, featuring simulated kidneys, colon, rectum, bladder, and prostate. The phantom represents a two-fold evolution in design philosophy—from 2D (cylindrically symmetric) to fully 3D, and from exclusively qualitative or quantitative to a design accommodating quantitative study within an anatomical context. It has proven a valuable tool in investigations throughout our institution, including low-dose CT, dual-energy radiography, and cone-beam CT for image-guided radiation therapy and surgery.

Non-metallic dopant modulation of conductivity in substoichiometric tantalum pentoxide: A first-principles study

DOE PAGES

Bondi, Robert J.; Fox, Brian P.; Marinella, Matthew J.

2017-06-01

Here, we apply density-functional theory calculations to predict dopant modulation of electrical conductivity (σ o) for seven dopants (C, Si, Ge, H, F, N, and B) sampled at 18 quantum molecular dynamics configurations of five independent insertion sites into two (high/low) baseline references of σo in amorphous Ta 2O 5, where each reference contains a single, neutral O vacancy center (V O 0). From this statistical population (n = 1260), we analyze defect levels, physical structure, and valence charge distributions to characterize nanoscale modification of the atomistic structure in local dopant neighborhoods. C is the most effective dopant at loweringmore » Ta 2O x σ o, while also exhibiting an amphoteric doping behavior by either donating or accepting charge depending on the host oxide matrix. Both B and F robustly increase Ta 2O x σ o, although F does so through elimination of Ta high charge outliers, while B insertion conversely creates high charge O outliers through favorable BO 3 group formation, especially in the low σ o reference. While N applications to dope and passivate oxides are prevalent, we also found that N exacerbates the stochasticity of σ o we sought to mitigate; sensitivity to the N insertion site and some propensity to form N-O bond chemistries appear responsible. Finally, we use direct first-principles predictions of σ o to explore feasible Ta 2O 5 dopants to engineer improved oxides with lower variance and greater repeatability to advance the manufacturability of resistive memory technologies.« less

New Insights into the Classification and Integration Specificity of Streptococcus Integrative Conjugative Elements through Extensive Genome Exploration

PubMed Central

Ambroset, Chloé; Coluzzi, Charles; Guédon, Gérard; Devignes, Marie-Dominique; Loux, Valentin; Lacroix, Thomas; Payot, Sophie; Leblond-Bourget, Nathalie

2016-01-01

Recent genome analyses suggest that integrative and conjugative elements (ICEs) are widespread in bacterial genomes and therefore play an essential role in horizontal transfer. However, only a few of these elements are precisely characterized and correctly delineated within sequenced bacterial genomes. Even though previous analysis showed the presence of ICEs in some species of Streptococci, the global prevalence and diversity of ICEs was not analyzed in this genus. In this study, we searched for ICEs in the completely sequenced genomes of 124 strains belonging to 27 streptococcal species. These exhaustive analyses revealed 105 putative ICEs and 26 slightly decayed elements whose limits were assessed and whose insertion site was identified. These ICEs were grouped in seven distinct unrelated or distantly related families, according to their conjugation modules. Integration of these streptococcal ICEs is catalyzed either by a site-specific tyrosine integrase, a low-specificity tyrosine integrase, a site-specific single serine integrase, a triplet of site-specific serine integrases or a DDE transposase. Analysis of their integration site led to the detection of 18 target-genes for streptococcal ICE insertion including eight that had not been identified previously (ftsK, guaA, lysS, mutT, rpmG, rpsI, traG, and ebfC). It also suggests that all specificities have evolved to minimize the impact of the insertion on the host. This overall analysis of streptococcal ICEs emphasizes their prevalence and diversity and demonstrates that exchanges or acquisitions of conjugation and recombination modules are frequent. PMID:26779141

New Insights into the Classification and Integration Specificity of Streptococcus Integrative Conjugative Elements through Extensive Genome Exploration.

PubMed

Ambroset, Chloé; Coluzzi, Charles; Guédon, Gérard; Devignes, Marie-Dominique; Loux, Valentin; Lacroix, Thomas; Payot, Sophie; Leblond-Bourget, Nathalie

2015-01-01

Recent genome analyses suggest that integrative and conjugative elements (ICEs) are widespread in bacterial genomes and therefore play an essential role in horizontal transfer. However, only a few of these elements are precisely characterized and correctly delineated within sequenced bacterial genomes. Even though previous analysis showed the presence of ICEs in some species of Streptococci, the global prevalence and diversity of ICEs was not analyzed in this genus. In this study, we searched for ICEs in the completely sequenced genomes of 124 strains belonging to 27 streptococcal species. These exhaustive analyses revealed 105 putative ICEs and 26 slightly decayed elements whose limits were assessed and whose insertion site was identified. These ICEs were grouped in seven distinct unrelated or distantly related families, according to their conjugation modules. Integration of these streptococcal ICEs is catalyzed either by a site-specific tyrosine integrase, a low-specificity tyrosine integrase, a site-specific single serine integrase, a triplet of site-specific serine integrases or a DDE transposase. Analysis of their integration site led to the detection of 18 target-genes for streptococcal ICE insertion including eight that had not been identified previously (ftsK, guaA, lysS, mutT, rpmG, rpsI, traG, and ebfC). It also suggests that all specificities have evolved to minimize the impact of the insertion on the host. This overall analysis of streptococcal ICEs emphasizes their prevalence and diversity and demonstrates that exchanges or acquisitions of conjugation and recombination modules are frequent.

Three-dimensional radiochromic film dosimetry for volumetric modulated arc therapy using a spiral water phantom.

PubMed

Tanooka, Masao; Doi, Hiroshi; Miura, Hideharu; Inoue, Hiroyuki; Niwa, Yasue; Takada, Yasuhiro; Fujiwara, Masayuki; Sakai, Toshiyuki; Sakamoto, Kiyoshi; Kamikonya, Norihiko; Hirota, Shozo

2013-11-01

We validated 3D radiochromic film dosimetry for volumetric modulated arc therapy (VMAT) using a newly developed spiral water phantom. The phantom consists of a main body and an insert box, each of which has an acrylic wall thickness of 3 mm and is filled with water. The insert box includes a spiral film box used for dose-distribution measurement, and a film holder for positioning a radiochromic film. The film holder has two parallel walls whose facing inner surfaces are equipped with spiral grooves in a mirrored configuration. The film is inserted into the spiral grooves by its side edges and runs along them to be positioned on a spiral plane. Dose calculation was performed by applying clinical VMAT plans to the spiral water phantom using a commercial Monte Carlo-based treatment-planning system, Monaco, whereas dose was measured by delivering the VMAT beams to the phantom. The calculated dose distributions were resampled on the spiral plane, and the dose distributions recorded on the film were scanned. Comparisons between the calculated and measured dose distributions yielded an average gamma-index pass rate of 87.0% (range, 91.2-84.6%) in nine prostate VMAT plans under 3 mm/3% criteria with a dose-calculation grid size of 2 mm. The pass rates were increased beyond 90% (average, 91.1%; range, 90.1-92.0%) when the dose-calculation grid size was decreased to 1 mm. We have confirmed that 3D radiochromic film dosimetry using the spiral water phantom is a simple and cost-effective approach to VMAT dose verification.

Battery with modular air cathode and anode cage

DOEpatents

Niksa, Marilyn J.; Pohto, Gerald R.; Lakatos, Leslie K.; Wheeler, Douglas J.; Niksa, Andrew J.; Schue, Thomas J.

1987-01-01

A battery assembly of the consumable metal anode type has now been constructed for ready assembly as well as disassembly. In a non-conductive and at least substantially inert cell body, space is provided for receiving an open-structured, non-consumable anode cage. The cage has an open top for facilitating insertion of an anode. A modular cathode is used, comprising a peripheral current conductor frame clamped about a grid reinforced air cathode in sheet form. The air cathode may be double gridded. The cathode frame can be sealed, during assembly, with electrolyte-resistant-sealant as well as with adhesive. The resulting cathode module can be assembled outside the cell body and readily inserted therein, or can later be easily removed therefrom.

Battery with modular air cathode and anode cage

DOEpatents

Niksa, Marilyn J.; Pohto, Gerald R.; Lakatos, Leslie K.; Wheeler, Douglas J.; Niksa, Andrew J.; Schue, Thomas J.; Turk, Thomas R.

1988-01-01

A battery assembly of the consumable metal anode type has now been constructed for ready assembly as well as disassembly. In a non-conductive and at least substantially inert cell body, space is provided for receiving an open-structured, non-consumable anode cage. The cage has an open top for facilitating insertion of an anode. A modular cathode is used, comprising a peripheral current conductor frame clamped about a grid reinforced air cathode in sheet form. The air cathode may be double gridded. The cathode frame can be sealed, during assembly, with electrolyte-resistant-sealant as well as with adhesive. The resulting cathode module can be assembled outside the cell body and readily inserted therein, or can later be easily removed therefrom.

Earth recovery mode analysis for a Martian sample return mission

NASA Technical Reports Server (NTRS)

Green, J. P.

1978-01-01

The analysis has concerned itself with evaluating alternative methods of recovering a sample module from a trans-earth trajectory originating in the vicinity of Mars. The major modes evaluated are: (1) direct atmospheric entry from trans-earth trajectory; (2) earth orbit insertion by retropropulsion; and (3) atmospheric braking to a capture orbit. In addition, the question of guided vs. unguided entry vehicles was considered, as well as alternative methods of recovery after orbit insertion for modes (2) and (3). A summary of results and conclusions is presented. Analytical results for aerodynamic and propulsive maneuvering vehicles are discussed. System performance requirements and alternatives for inertial systems implementation are also discussed. Orbital recovery operations and further studies required to resolve the recovery mode issue are described.

Method of making a unitized electrode assembly

DOEpatents

Niksa, Marilyn J.; Pohto, Gerald R.; Lakatos, Leslie K.; Wheeler, Douglas J.; Solomon, Frank; Niksa, Andrew J.; Schue, Thomas J.; Genodman, Yury; Turk, Thomas R.; Hagel, Daniel P.

1988-01-01

A battery assembly of the consumable metal anode type has now been constructed for ready assembly as well as disassembly. In a non-conductive and at least substantially inert cell body, space is provided for receiving an open-structured, non-consumable anode cage. The cage has an open top for facilitating insertion of an anode. A modular cathode is used, comprising a peripheral current conductor frame clamped about a grid reinforced air cathode in sheet form. The air cathode may be double gridded. The cathode frame can be sealed, during assembly, with electrolyte-resistant-sealant as well as with adhesive. The resulting cathode module can be assembled outside the cell body and readily inserted therein, or can later be easily removed therefrom.

Method of making a unitized electrode assembly

DOEpatents

Niksa, M.J.; Pohto, G.R.; Lakatos, L.K.; Wheeler, D.J.; Solomon, F.; Niksa, A.J.; Schue, T.J.; Genodman, Y.; Turk, T.R.; Hagel, D.P.

1988-12-06

A battery assembly of the consumable metal anode type has now been constructed for ready assembly as well as disassembly. In a non-conductive and at least substantially inert cell body, space is provided for receiving an open-structured, non-consumable anode cage. The cage has an open top for facilitating insertion of an anode. A modular cathode is used, comprising a peripheral current conductor frame clamped about a grid reinforced air cathode in sheet form. The air cathode may be double gridded. The cathode frame can be sealed, during assembly, with electrolyte-resistant-sealant as well as with adhesive. The resulting cathode module can be assembled outside the cell body and readily inserted therein, or can later be easily removed therefrom. 6 figs.

Effect of High-speed Milling tool path strategies on the surface roughness of Stavax ESR mold insert machining

NASA Astrophysics Data System (ADS)

Mebrahitom, A.; Rizuan, D.; Azmir, M.; Nassif, M.

2016-02-01

High speed milling is one of the recent technologies used to produce mould inserts due to the need for high surface finish. It is a faster machining process where it uses a small side step and a small down step combined with very high spindle speed and feed rate. In order to effectively use the HSM capabilities, optimizing the tool path strategies and machining parameters is an important issue. In this paper, six different tool path strategies have been investigated on the surface finish and machining time of a rectangular cavities of ESR Stavax material. CAD/CAM application of CATIA V5 machining module for pocket milling of the cavities was used for process planning.

Hands-on work fine-tunes X-band PIN-diode duplexer

NASA Astrophysics Data System (ADS)

Schneider, P.

1985-06-01

Computer-aided design (CAD) programs for fabricating PIN-diode duplexers are useful in avoiding time-consuming cut-and-try techniques. Nevertheless, to attain minimum insertion loss, only experimentation yields the optimum microstrip circuitry. A PIN-diode duplexer, consisting of two SPST PIN-diode switches and a pair of 3-dB Lange microstrip couplers, designed for an X-band transmit/receive module exemplifies what is possible when computer-derived designs and experimentation are used together. Differences between the measured and computer-generated figures for insertion loss can be attributed to several factors not included in the CAD program - for example, radiation and connector losses. Mechanical tolerances of the microstrip PC board and variations in the SMA connector-to-microstrip transition contribute to the discrepancy.

Investigations of Q-switching and mode locking in diode-pumped Nd:YVO4 laser with passive saturable absorbers

NASA Astrophysics Data System (ADS)

Kwiatkowski, Jacek; Jabczynski, Jan K.; Zendzian, Waldemar

2005-03-01

The saturable absorbers (Cr4+:YAG, GaAs and LiF crystals for 1064-nm wavelength, V3+:YAG crystals for 1340-nm respectively) were examined as passive Mode Lockers and Q-switches in diode pumped Nd:YVO4 lasers in the Z-type resonators. In each case, partially modulated long trains of QML pulses were observed. As a rule, envelopes with about 1 μs duration and more than 50% depth of modulation were observed. For stabilization of the mode locking trains nonlinear crystals (KTP or LBO) as negative feedback elements were inserted. The fully modulated QML trains for intracavity II harmonic conversion at 670-nm wavelength in V3+:YAG Q-switched Nd:YVO4 laser with LBO crystal were demonstrated.

Differential effects of simple repeating DNA sequences on gene expression from the SV40 early promoter.

PubMed

Amirhaeri, S; Wohlrab, F; Wells, R D

1995-02-17

The influence of simple repeat sequences, cloned into different positions relative to the SV40 early promoter/enhancer, on the transient expression of the chloramphenicol acetyltransferase (CAT) gene was investigated. Insertion of (G)29.(C)29 in either orientation into the 5'-untranslated region of the CAT gene reduced expression in CV-1 cells 50-100 fold when compared with controls with random sequence inserts. Analysis of CAT-specific mRNA levels demonstrated that the effect was due to a reduction of CAT mRNA production rather than to posttranscriptional events. In contrast, insertion of the same insert in either orientation upstream of the promoter-enhancer or downstream of the gene stimulated gene expression 2-3-fold. These effects could be reversed by cotransfection of a competitor plasmid carrying (G)25.(C)25 sequences. The results suggest that a G.C-binding transcription factor modulates gene expression in this system and that promoter strength can be regulated by providing protein-binding sites in trans. Although constructs containing longer tracts of alternating (C-G), (T-G), or (A-T) sequences inhibited CAT expression when inserted in the 5'-untranslated region of the CAT gene, the amount of CAT mRNA was unaffected. Hence, these inhibitions must be due to posttranscriptional events, presumably at the level of translation. These effects of microsatellite sequences on gene expression are discussed with respect to recent data on related simple repeat sequences which cause several human genetic diseases.

Abscisic acid has a key role in modulating diverse plant-pathogen interactions

Treesearch

Jun Fan; Lionel Hill; Casey Crooks; Peter Doerner; Chris Lamb

2009-01-01

We isolated an activation-tagged Arabidopsis (Arabidopsis thaliana) line, constitutive disease susceptibility2-1D (cds2-1D), that showed enhanced bacterial growth when challenged with various Pseudomonas syringae strains. Systemic acquired resistance and systemic PATHOGENESIS-RELATED GENE1 induction were also compromised in cds2-1D. The T-DNA insertion adjacent to NINE...

Microgravity

NASA Image and Video Library

2004-04-15

Structure Of Flame Balls At Low Lewis-numbers (SOFBALL) Experiment Mounting Structure (EMS) was used to conduct the SOFBALL experiment on Combustion Module-1. The EMS was inserted into the CM-1 combustion chamber. The chamber was filled with a lean fuel/oxidizer mixture and a spark igniter on the EMS ignited the gas. Very small, weak flames, in the shape of spheres, were formed and studied.

Teaching symmetry in the introductory physics curriculum

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

Hill, C. T.; Lederman, L. M.

Modern physics is largely defined by fundamental symmetry principles and Noether's Theorem. Yet these are not taught, or rarely mentioned, to beginning students, thus missing an opportunity to reveal that the subject of physics is as lively and contemporary as molecular biology, and as beautiful as the arts. We prescribe a symmetry module to insert into the curriculum, of a week's length.

Enhanced all-optical modulation in a graphene-coated fibre with low insertion loss

PubMed Central

Zhang, Haojie; Healy, Noel; Shen, Li; Huang, Chung Che; Hewak, Daniel W.; Peacock, Anna C.

2016-01-01

Graphene is a highly versatile two-dimensional material platform that offers exceptional optical and electrical properties. Of these, its dynamic conductivity and low effective carrier mass are of particular interest for optoelectronic applications as they underpin the material’s broadband nonlinear optical absorption and ultra-fast carrier mobility, respectively. In this paper, we utilize these phenomena to demonstrate a high-speed, in-fibre optical modulator developed on a side-polished optical fibre platform. An especially low insertion loss (<1 dB) was achieved by polishing the fibre to a near atomically smooth surface (<1 nm RMS), which minimized scattering and ensured excellent contact between the graphene film and the fibre. In order to enhance the light-matter interaction, the graphene film is coated with a high index polyvinyl butyral layer, which has the added advantage of acting as a barrier to the surrounding environment. Using this innovative approach, we have fabricated a robust and stable all-fibre device with an extinction ratio as high as 9 dB and operation bandwidth of 0.5 THz. These results represent a key step towards the integration of low-dimensional materials within standard telecoms networks. PMID:27001353

Synchronized conductivity modulation to realize broadband lossless magnetic-free non-reciprocity.

PubMed

Dinc, Tolga; Tymchenko, Mykhailo; Nagulu, Aravind; Sounas, Dimitrios; Alu, Andrea; Krishnaswamy, Harish

2017-10-06

Recent research has explored the spatiotemporal modulation of permittivity to break Lorentz reciprocity in a manner compatible with integrated-circuit fabrication. However, permittivity modulation is inherently weak and accompanied by loss due to carrier injection, particularly at higher frequencies, resulting in large insertion loss, size, and/or narrow operation bandwidths. Here, we show that the presence of absorption in an integrated electronic circuit may be counter-intuitively used to our advantage to realize a new generation of magnet-free non-reciprocal components. We exploit the fact that conductivity in semiconductors provides a modulation index several orders of magnitude larger than permittivity. While directly associated with loss in static systems, we show that properly synchronized conductivity modulation enables loss-free, compact and extremely broadband non-reciprocity. We apply these concepts to obtain a wide range of responses, from isolation to gyration and circulation, and verify our findings by realizing a millimeter-wave (25 GHz) circulator fully integrated in complementary metal-oxide-semiconductor technology.Optical non-reciprocity achieved through refractive index modulation can have its challenges and limitations. Here, Dinc et al. introduce the concept of non-reciprocity based on synchronized spatio-temporal modulation of conductivity to achieve different types of non-reciprocal functionality.

Structural basis for highly effective HIV-1 neutralization by CD4-mimetic miniproteins revealed by 1.5 Å co-crystal structure of gp120 and M48U1

PubMed Central

Acharya, Priyamvada; Luongo, Timothy; Louder, Mark K.; McKee, Krisha; Yang, Yongping; Kwon, Young Do; Mascola, John R.; Kessler, Pascal; Martin, Loïc; Kwong, Peter D.

2014-01-01

The interface between HIV-1 gp120 envelope glycoprotein and CD4 receptor contains an unusual interfacial cavity, the “Phe43 cavity”, which miniprotein mimetics of CD4 with non-natural extensions can potentially utilize to enhance their neutralization of HIV-1. Here we report co-crystal structures of HIV-1 gp120 with miniproteins M48U1 and M48U7, which insert cyclohexylmethoxy and 5-hydroxypentylmethoxy extensions, respectively, into the Phe43 cavity. Both inserts displayed flexibility and hydrophobic interactions, but the M48U1 insert showed better shape complementarity with the Phe43 cavity than the M48U7 insert. Subtle alteration in gp120 conformation played a substantial role in optimizing fit. With M48U1, these translated into a YU2-gp120 affinity of 0.015 nM and neutralization of all 180-circulating HIV-1 strains tested, except clade-A/E isolates with non-canonical Phe43 cavities. Ligand chemistry, shape complementary, surface burial, and gp120 conformation act in concert to modulate binding of ligands to the gp120-Phe43 cavity and, when optimized, can effect near pan-neutralization of HIV-1. PMID:23707685

Direct 3D cell-printing of human skin with functional transwell system.

PubMed

Kim, Byoung Soo; Lee, Jung-Seob; Gao, Ge; Cho, Dong-Woo

2017-06-06

Three-dimensional (3D) cell-printing has been emerging as a promising technology with which to build up human skin models by enabling rapid and versatile design. Despite the technological advances, challenges remain in the development of fully functional models that recapitulate complexities in the native tissue. Moreover, although several approaches have been explored for the development of biomimetic human skin models, the present skin models based on multistep fabrication methods using polydimethylsiloxane chips and commercial transwell inserts could be tackled by leveraging 3D cell-printing technology. In this paper, we present a new 3D cell-printing strategy for engineering a 3D human skin model with a functional transwell system in a single-step process. A hybrid 3D cell-printing system was developed, allowing for the use of extrusion and inkjet modules at the same time. We began by revealing the significance of each module in engineering human skin models; by using the extrusion-dispensing module, we engineered a collagen-based construct with polycaprolactone (PCL) mesh that prevented the contraction of collagen during tissue maturation; the inkjet-based dispensing module was used to uniformly distribute keratinocytes. Taking these features together, we engineered a human skin model with a functional transwell system; the transwell system and fibroblast-populated dermis were consecutively fabricated by using the extrusion modules. Following this process, keratinocytes were uniformly distributed onto the engineered dermis by the inkjet module. Our transwell system indicates a supportive 3D construct composed of PCL, enabling the maturation of a skin model without the aid of commercial transwell inserts. This skin model revealed favorable biological characteristics that included a stabilized fibroblast-stretched dermis and stratified epidermis layers after 14 days. It was also observed that a 50 times reduction in cost was achieved and 10 times less medium was used than in a conventional culture. Collectively, because this single-step process opens up chances for versatile designs, we envision that our cell-printing strategy could provide an attractive platform in engineering various human skin models.

Polymer planar lightwave circuit based hybrid-integrated coherent receiver for advanced modulation signals

NASA Astrophysics Data System (ADS)

Wang, Jin; Han, Yang; Liang, Zhongcheng; Chen, Yongjin

2012-11-01

Applying coherent detection technique to advanced modulation formats makes it possible to electronically compensate the signal impairments. A key issue for a successful deployment of coherent detection technique is the availability of cost-efficient and compact integrated receivers, which are composed of an optical 90° hybrid mixer and four photodiodes (PDs). In this work, three different types of optical hybrids are fabricated with polymer planar lightwave circuit (PLC), and hybridly integrated with four vertical backside illuminated III-V PDs. Their performances, such as the insertion loss, the transmission imbalance, the polarization dependence and the phase deviation of 90° hybrid will be discussed.

Demodulator for binary-phase modulated signals having a variable clock rate

NASA Technical Reports Server (NTRS)

Wu, Ta Tzu (Inventor)

1976-01-01

Method and apparatus for demodulating binary-phase modulated signals recorded on a magnetic stripe on a card as the card is manually inserted into a card reader. Magnetic transitions are sensed as the card is read and the time interval between immediately preceeding basic transitions determines the duration of a data sampling pulse which detects the presence or absence of an intermediate transition pulse indicative of two respective logic states. The duration of the data sampling pulse is approximately 75 percent of the preceeding interval between basic transitions to permit tracking succeeding time differences in basic transition intervals of up to approximately 25 percent.

Space-multiplexed optical scanner.

PubMed

Riza, Nabeel A; Yaqoob, Zahid

2004-05-01

A low-loss two-dimensional optical beam scanner that is capable of delivering large (e.g., > 10 degrees) angular scans along the elevation as well as the azimuthal direction is presented. The proposed scanner is based on a space-switched parallel-serial architecture that employs a coarse-scanner module and a fine-scanner module that produce an ultrahigh scan space-fill factor, e.g., 900 x 900 distinguishable beams in a 10 degrees (elevation) x 10 degrees (azimuth) scan space. The experimentally demonstrated one-dimensional version of the proposed scanner has a supercontinuous scan, 100 distinguishable beam spots in a 2.29 degrees total scan range, and 1.5-dB optical insertion loss.

Laboratory racks are installed in the MPLM Leonardo

NASA Technical Reports Server (NTRS)

2000-01-01

In the Space Station Processing Facility, another laboratory rack is placed on the arm of the Rack Insertion Unit to lift it to the workstand height of the Multi-Purpose Logistics Module Leonardo (not seen). The MPLM will transport laboratory racks filled with equipment, experiments and supplies to and from the International Space Station aboard the Space Shuttle. Leonardo will be launched for the first time March 1, 2001, on Shuttle mission STS-102. On that flight, Leonardo will be filled with equipment and supplies to outfit the U.S. laboratory module, being carried to the ISS on the Jan. 19, 2001, launch of STS-98.

Simultaneous PET/MR imaging with a radio frequency-penetrable PET insert

PubMed Central

Grant, Alexander M.; Lee, Brian J.; Chang, Chen-Ming; Levin, Craig S.

2017-01-01

Purpose A brain sized radio-frequency (RF)-penetrable PET insert has been designed for simultaneous operation with MRI systems. This system takes advantage of electro-optical coupling and battery power to electrically float the PET insert relative to the MRI ground, permitting RF signals to be transmitted through small gaps between the modules that form the PET ring. This design facilitates the use of the built-in body coil for RF transmission, and thus could be inserted into any existing MR site wishing to achieve simultaneous PET/MR imaging. The PET detectors employ non-magnetic silicon photomultipliers in conjunction with a compressed sensing signal multiplexing scheme, and optical fibers to transmit analog PET detector signals out of the MRI room for decoding, processing, and image reconstruction. Methods The PET insert was first constructed and tested in a laboratory benchtop setting, where tomographic images of a custom resolution phantom were successfully acquired. The PET insert was then placed within a 3T body MRI system, and tomographic resolution/contrast phantom images were acquired both with only the B0 field present, and under continuous pulsing from different MR imaging sequences. Results The resulting PET images have comparable contrast-to-noise ratios (CNR) under all MR pulsing conditions: the maximum percent CNR relative difference for each rod type among all four PET images acquired in the MRI system has a mean of 14.0±7.7%. MR images were successfully acquired through the RF-penetrable PET shielding using only the built-in MR body coil, suggesting that simultaneous imaging is possible without significant mutual interference. Conclusions These results show promise for this technology as an alternative to costly integrated PET/MR scanners; a PET insert that is compatible with any existing clinical MRI system could greatly increase the availability, accessibility, and dissemination of PET/MR. PMID:28102949

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

NASA Astrophysics Data System (ADS)

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.

Microwave fiber optics delay line

NASA Astrophysics Data System (ADS)

Slayman, C.; Yen, H. W.

1980-01-01

A microwave delay line is one of the devices used in EW systems for preserving the frequency and phase contents of RF signals. For such applications, delay lines are required to have large dynamic range, wide bandwidth, low insertion loss, and a linear response. The basic components of a fiber-optics delay line are: an optical source, a wideband optical modulator, a spool of single-mode fiber with appropriate length to provide a given microwave signal delay, and a high-speed photodetector with an RF amplifier. This contract program is to study the feasibility of such a fiber-optic delay line in the frequency range of 4.0 to 6.5 GHz. The modulation scheme studied is the direct modulation of injection lasers. The most important issue identified is the frequency response of the injection laser and the photodetector.

Low-chirp high-extinction-ratio modulator based on graphene-silicon waveguide.

PubMed

Yang, Longzhi; Hu, Ting; Hao, Ran; Qiu, Chen; Xu, Chao; Yu, Hui; Xu, Yang; Jiang, Xiaoqing; Li, Yubo; Yang, Jianyi

2013-07-15

We present a hybrid graphene-silicon waveguide, which consists of a lateral slot waveguide with three layers of graphene flakes inside. Through a theoretical analysis, an effective index variation for about 0.05 is found in the waveguide by applying a voltage on the graphene. We designed a Mach-Zehnder modulator based on this waveguide and demonstrated it can process signals nearly chirp-free. The calculation shows that the driving voltage is only 1 V even if the length of the arm is shortened to be 43.54 μm. An extinction up to 34.7 dB and a minimum chirp parameter of -0.006 are obtained. Its insertion loss is roughly -1.37 dB. This modulator consumes low power and has a small footprint. It can potentially be ultrafast as well as CMOS compatible.

Quantum hacking of two-way continuous-variable quantum key distribution using Trojan-horse attack

NASA Astrophysics Data System (ADS)

Ma, Hong-Xin; Bao, Wan-Su; Li, Hong-Wei; Chou, Chun

2016-08-01

We present a Trojan-horse attack on the practical two-way continuous-variable quantum key distribution system. Our attack mainly focuses on the imperfection of the practical system that the modulator has a redundancy of modulation pulse-width, which leaves a loophole for the eavesdropper inserting a Trojan-horse pulse. Utilizing the unique characteristics of two-way continuous-variable quantum key distribution that Alice only takes modulation operation on the received mode without any measurement, this attack allows the eavesdropper to render all of the final keys shared between the legitimate parties insecure without being detected. After analyzing the feasibility of the attack, the corresponding countermeasures are put forward. Project supported by the National Basic Research Program of China (Grant No. 2013CB338002) and the National Natural Science Foundation of China (Grant Nos. 11304397 and 61505261).

MO detector (MOD): a dual-function optical modulator-detector for on-chip communication

NASA Astrophysics Data System (ADS)

Sun, Shuai; Zhang, Ruoyu; Peng, Jiaxin; Narayana, Vikram K.; Dalir, Hamed; El-Ghazawi, Tarek; Sorger, Volker J.

2018-04-01

Physical challenges at the device and interconnect level limit both network and computing energy efficiency. While photonics is being considered to address interconnect bottlenecks, optical routing is still limited by electronic circuitry, requiring substantial overhead for optical-electrical-optical conversion. Here we show a novel design of an integrated broadband photonic-plasmonic hybrid device termed MODetector featuring dual light modulation and detection function to act as an optical transceiver in the photonic network-on-chip. With over 10 dB extinction ratio and 0.8 dB insertion loss at the modulation state, this MODetector provides 0.7 W/A responsivity in the detection state with 36 ps response time. This multi-functional device: (i) eliminates OEO conversion, (ii) reduces optical losses from photodetectors when not needed, and (iii) enables cognitive routing strategies for network-on-chips.

Canonical translation-modulating OFF-riboswitches with a single aptamer binding to a small molecule that function in a higher eukaryotic cell-free expression system.

PubMed

Ogawa, Atsushi; Murashige, Yuta; Takahashi, Hajime

2018-06-19

We have found that OFF-riboswitches that ligand-dependently downregulate the canonical translation in a higher eukaryotic expression system (wheat germ extract) can be easily created by inserting a single aptamer into the 5' untranslated region (UTR) of mRNA, even if its ligand is as small as theophylline. The key is the position of the inserted aptamer: the 5' end (+0 position) is much better than other positions for inhibiting canonical translation with the aptamer-ligand complex. The data showed that ribosome loading is suppressed by a rigid structure in the 5' end, and this suppression is dependent on the structure's stability but not on its size. Although this preference of aptamer insertion point contradicts the results in a lower eukaryote, it accords with the fact that the 5'-end structural hindrance is more effective for blocking the ribosome in higher eukaryotes. Therefore, the present type of OFF-riboswitch would function in various higher eukaryotic expression systems. Copyright © 2018 Elsevier Ltd. All rights reserved.

Placing three-dimensional isoparametric elements into NASTRAN. [alterations in matrix assembly to simplify generation of higher order elements

NASA Technical Reports Server (NTRS)

Newman, M. B.; Filstrup, A. W.

1973-01-01

Linear (8 node), parabolic (20 node), cubic (32 node) and mixed (some edges linear, some parabolic and some cubic) have been inserted into NASTRAN, level 15.1. First the dummy element feature was used to check out the stiffness matrix generation routines for the linear element in NASTRAN. Then, the necessary modules of NASTRAN were modified to include the new family of elements. The matrix assembly was changed so that the stiffness matrix of each isoparametric element is only generated once as the time to generate these higher order elements tends to be much longer than the other elements in NASTRAN. This paper presents some of the experiences and difficulties of inserting a new element or family of elements into NASTRAN.

Modeling of 3D Structure of Chimeric Constructs Based on Hemagglutinin of Influenza Virus and Immunogenic Epitopes of Streptococcus Agalactiae.

PubMed

Fedorova, E A; Smolonogina, T A; Isakova-Sivak, I N; Koren'kov, D A; Kotomina, T S; Leont'eva, G F; Suvorov, A N; Rudenko, L G

2018-04-01

A project of an experimental recombinant vector vaccine for prevention of diseases caused by pathogenic streptococci based on ScaAB lipoprotein of Streptococcus agalactiae and a coldadapted strain of live influenza vaccine as a vector was developed. The sequence of ScaAB lipoprotein was analyzed and fragments forming immunodominant epitopes were determined. Chimeric molecules of influenza virus hemagglutinin H7 carrying insertions of bacterial origin were constructed. Based on the results of simulation, the most promising variants were selected; they represented fragments of lipoprotein ScaAB lacking N-terminal domain bound to hemagglutinin via a flexible linker. These insertions should minimally modulate the properties of the influenza strain, while retaining potential immunogenicity to a wide group of pathogenic streptococci.

SU-G-IeP2-15: Virtual Insertion of Digital Kidney Stones Into Dual-Source, Dual- Energy CT Projection Data

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

Ferrero, A; Chen, B; Huang, A

Purpose: In order to investigate novel methods to more accurately estimate the mineral composition of kidney stones using dual energy CT, it is desirable to be able to combine digital stones of known composition with actual phantom and patient scan data. In this work, we developed and validated a method to insert digital kidney stones into projection data acquired on a dual-source, dual-energy CT system. Methods: Attenuation properties of stones of different mineral composition were computed using tabulated mass attenuation coefficients, the chemical formula for each stone type, and the effective beam energy at each evaluated tube potential. A previouslymore » developed method to insert lesions into x-ray CT projection data was extended to include simultaneous dual-energy CT projections acquired on a dual-source gantry (Siemens Somatom Flash). Digital stones were forward projected onto both detectors and the resulting projections added to the physically acquired sinogram data. To validate the accuracy of the technique, digital stones were inserted into different locations in the ACR CT accreditation phantom; low and high contrast resolution, CT number accuracy and noise properties were compared before and after stone insertion. The procedure was repeated for two dual-energy tube potential pairs in clinical use on the scanner, 80/Sn140 kV and 100/Sn140 kV, respectively. Results: The images reconstructed after the insertion of digital kidney stones were consistent with the images reconstructed from the scanner. The largest average CT number difference for the 4 insert in the CT number accuracy module of the phantom was 3 HU. Conclusion: A framework was developed and validated for the creation of digital kidney stones of known mineral composition, and their projection-domain insertion into commercial dual-source, dual-energy CT projection data. This will allow a systematic investigation of the impact of scan and reconstruction parameters on stone attenuation and dual-energy behavior under rigorously controlled conditions. Dr. McCollough receives research support from Siemens Healthcare.« less

Polymer electro-optic waveguide devices: Low-loss etchless fabrication techniques and passive-to-active integration

NASA Astrophysics Data System (ADS)

Geary, Kevin

The development of high-frequency polymer electro-optic modulators has seen steady and significant progress in recent years, yet applications of these promising materials to more complicated integrated optic structures and arrays of devices have been limited primarily due to high optical waveguide loss characteristics. This is unfortunate since a major advantage of polymers as photonic materials is their compatibility with photolithographic processing of large components. In this Dissertation, etchless waveguide writing techniques are presented in order to improve the overall optical insertion loss of electro-optic polymer waveguide devices. These techniques include poling-induced writing, stress-induced waveguide writing, and photobleaching. Using these waveguide writing mechanisms, we have demonstrated straight waveguides, phase modulators, Mach-Zehnder intensity modulators, variable optical attenuators, and multimode interference (MMI) power splitters, all with improved loss characteristics over their etched rib waveguide counterparts. Ultimately, the insertion loss of an integrated optic device is limited by the actual material loss of the core waveguide material. In this Dissertation, passive-to-active polymer waveguide transitions are proposed to circumvent this problem. These transitions are compact, in-plane, self-aligned, and require no tapering of any physical dimensions of the waveguides. By utilizing both the time-dependent and intensity-dependent photobleaching characteristics of electro-optic polymer materials, adiabatic refractive index tapers can be seamlessly coupled to in-plane butt couple transitions, resulting in losses as low as 0.1 dB per interface. By integrating passive polymer planar lightwave circuits with the high-speed phase shifting capability of electro-optic polymers, active wideband photonic devices of increased size and complexity can be realized. Optical fiber-to-device coupling can also result in significant contributions to the overall insertion loss of an integrated electro-optic polymer device. In this Dissertation, we leverage the photobleached refractive index taper component of our proposed passive-to-active polymer waveguide transitions in order to realize a two-dimensional optical mode transformer for improved overall fiber-to-device coupling of electro-optic polymer waveguide devices.

The MINDView brain PET detector, feasibility study based on SiPM arrays

NASA Astrophysics Data System (ADS)

González, Antonio J.; Majewski, Stan; Sánchez, Filomeno; Aussenhofer, Sebastian; Aguilar, Albert; Conde, Pablo; Hernández, Liczandro; Vidal, Luis F.; Pani, Roberto; Bettiol, Marco; Fabbri, Andrea; Bert, Julien; Visvikis, Dimitris; Jackson, Carl; Murphy, John; O'Neill, Kevin; Benlloch, Jose M.

2016-05-01

The Multimodal Imaging of Neurological Disorders (MINDView) project aims to develop a dedicated brain Positron Emission Tomography (PET) scanner with sufficient resolution and sensitivity to visualize neurotransmitter pathways and their disruptions in mental disorders for diagnosis and follow-up treatment. The PET system should be compact and fully compatible with a Magnetic Resonance Imaging (MRI) device in order to allow its operation as a PET brain insert in a hybrid imaging setup with most MRI scanners. The proposed design will enable the currently-installed MRI base to be easily upgraded to PET/MRI systems. The current design for the PET insert consists of a 3-ring configuration with 20 modules per ring and an axial field of view of ~15 cm and a geometrical aperture of ~33 cm in diameter. When coupled to the new head Radio Frequency (RF) coil, the inner usable diameter of the complete PET-RF coil insert is reduced to 26 cm. Two scintillator configurations have been tested, namely a 3-layer staggered array of LYSO with 1.5 mm pixel size, with 35×35 elements (6 mm thickness each) and a black-painted monolithic LYSO block also covering about 50×50 mm2 active area with 20 mm thickness. Laboratory test results associated with the current MINDView PET module concept are presented in terms of key parameters' optimization, such as spatial and energy resolution, sensitivity and Depth of Interaction (DOI) capability. It was possible to resolve all pixel elements from the three scintillator layers with energy resolutions as good as 10%. The monolithic scintillator showed average detector resolutions varying from 3.5 mm in the entrance layer to better than 1.5 mm near the photosensor, with average energy resolutions of about 17%.

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

Zhang, R; Jee, K; Sharp, G

Purpose: Proton radiography, which images the patients with the same type of particles that they are to be treated with, is a promising approach for image guidance and range uncertainties reduction. This study aimed to realize quality proton radiography by measuring dose rate functions (DRF) in time domain using a single flat panel and retrieve water equivalent path length (WEPL) from them. Methods: An amorphous silicon flat panel (PaxScan™ 4030CB, Varian Medical Systems, Inc., Palo Alto, CA) was placed behind phantoms to measure DRFs from a proton beam modulated by the modulator wheel. To retrieve WEPL and RSP, calibration modelsmore » based on the intensity of DRFs only, root mean square (RMS) of DRFs only and the intensity weighted RMS were tested. The quality of obtained WEPL images (in terms of spatial resolution and level of details) and the accuracy of WEPL were compared. Results: RSPs for most of the Gammex phantom inserts were retrieved within ± 1% errors by calibration models based on the RMS and intensity weighted RMS. The mean percentage error for all inserts was reduced from 1.08% to 0.75% by matching intensity in the calibration model. In specific cases such as the insert with a titanium rod, the calibration model based on RMS only fails while the that based on intensity weighted RMS is still valid. The quality of retrieved WEPL images were significantly improved for calibration models including intensity matching. Conclusion: For the first time, a flat panel, which is readily available in the beamline for image guidance, was tested to acquire quality proton radiography with WEPL accurately retrieved from it. This technique is promising to be applied for image-guided proton therapy as well as patient specific RSP determination to reduce uncertainties of beam ranges.« less

Three-dimensional radiochromic film dosimetry for volumetric modulated arc therapy using a spiral water phantom

PubMed Central

Tanooka, Masao; Doi, Hiroshi; Miura, Hideharu; Inoue, Hiroyuki; Niwa, Yasue; Takada, Yasuhiro; Fujiwara, Masayuki; Sakai, Toshiyuki; Sakamoto, Kiyoshi; Kamikonya, Norihiko; Hirota, Shozo

2013-01-01

We validated 3D radiochromic film dosimetry for volumetric modulated arc therapy (VMAT) using a newly developed spiral water phantom. The phantom consists of a main body and an insert box, each of which has an acrylic wall thickness of 3 mm and is filled with water. The insert box includes a spiral film box used for dose-distribution measurement, and a film holder for positioning a radiochromic film. The film holder has two parallel walls whose facing inner surfaces are equipped with spiral grooves in a mirrored configuration. The film is inserted into the spiral grooves by its side edges and runs along them to be positioned on a spiral plane. Dose calculation was performed by applying clinical VMAT plans to the spiral water phantom using a commercial Monte Carlo-based treatment-planning system, Monaco, whereas dose was measured by delivering the VMAT beams to the phantom. The calculated dose distributions were resampled on the spiral plane, and the dose distributions recorded on the film were scanned. Comparisons between the calculated and measured dose distributions yielded an average gamma-index pass rate of 87.0% (range, 91.2–84.6%) in nine prostate VMAT plans under 3 mm/3% criteria with a dose-calculation grid size of 2 mm. The pass rates were increased beyond 90% (average, 91.1%; range, 90.1–92.0%) when the dose-calculation grid size was decreased to 1 mm. We have confirmed that 3D radiochromic film dosimetry using the spiral water phantom is a simple and cost-effective approach to VMAT dose verification. PMID:23685667

Robot-assisted real-time magnetic resonance image-guided transcatheter aortic valve replacement.

PubMed

Miller, Justin G; Li, Ming; Mazilu, Dumitru; Hunt, Tim; Horvath, Keith A

2016-05-01

Real-time magnetic resonance imaging (rtMRI)-guided transcatheter aortic valve replacement (TAVR) offers improved visualization, real-time imaging, and pinpoint accuracy with device delivery. Unfortunately, performing a TAVR in a MRI scanner can be a difficult task owing to limited space and an awkward working environment. Our solution was to design a MRI-compatible robot-assisted device to insert and deploy a self-expanding valve from a remote computer console. We present our preliminary results in a swine model. We used an MRI-compatible robotic arm and developed a valve delivery module. A 12-mm trocar was inserted in the apex of the heart via a subxiphoid incision. The delivery device and nitinol stented prosthesis were mounted on the robot. Two continuous real-time imaging planes provided a virtual real-time 3-dimensional reconstruction. The valve was deployed remotely by the surgeon via a graphic user interface. In this acute nonsurvival study, 8 swine underwent robot-assisted rtMRI TAVR for evaluation of feasibility. Device deployment took a mean of 61 ± 5 seconds. Postdeployment necropsy was performed to confirm correlations between imaging and actual valve positions. These results demonstrate the feasibility of robotic-assisted TAVR using rtMRI guidance. This approach may eliminate some of the challenges of performing a procedure while working inside of an MRI scanner, and may improve the success of TAVR. It provides superior visualization during the insertion process, pinpoint accuracy of deployment, and, potentially, communication between the imaging device and the robotic module to prevent incorrect or misaligned deployment. Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

30GHz Ge electro-absorption modulator integrated with 3 μm silicon-on-insulator waveguide.

PubMed

Feng, Ning-Ning; Feng, Dazeng; Liao, Shirong; Wang, Xin; Dong, Po; Liang, Hong; Kung, Cheng-Chih; Qian, Wei; Fong, Joan; Shafiiha, Roshanak; Luo, Ying; Cunningham, Jack; Krishnamoorthy, Ashok V; Asghari, Mehdi

2011-04-11

We demonstrate a compact waveguide-based high-speed Ge electro-absorption (EA) modulator integrated with a single mode 3 µm silicon-on-isolator (SOI) waveguide. The Ge EA modulator is based on a horizontally-oriented p-i-n structure butt-coupled with a deep-etched silicon waveguide, which transitions adiabatically to a shallow-etched single mode large core SOI waveguide. The demonstrated device has a compact active region of 1.0 × 45 µm(2), a total insertion loss of 2.5-5 dB and an extinction ratio of 4-7.5 dB over a wavelength range of 1610-1640 nm with -4V(pp) bias. The estimated Δα/α value is in the range of 2-3.3. The 3 dB bandwidth measurements show that the device is capable of operating at more than 30 GHz. Clear eye-diagram openings at 12.5 Gbps demonstrates large signal modulation at high transmission rate. © 2011 Optical Society of America

80-Channel Multiplexer-Demultiplexer Module for DWDM Communications using Hybrid AWG -- Interleaver Technology

NASA Astrophysics Data System (ADS)

Rablau, Corneliu; Bredthauer, Lance

2007-10-01

Aside from the more traditional data, voice and e-mail communications, new bandwidth intensive applications in the larger consumer markets, such as music, digital pictures and movies, have led to an explosive increase in the demand for transmission capacity for optical communications networks. This has resulted in a widespread deployment of Dense Wavelength Division Multiplexing (DWDM) as a means of increasing the communications capacity by multiplexing and transmitting signals of different wavelengths (establishing multiple communication channels) through a single strand of fiber. We report on the design, assembly and characterization of a 50-GHz, 80-channel Mux-Demux module for DWDM systems. The module has been assembled from two commercially available 100 GHz, 40-channel Array Waveguide Grating (AWG) modules and a 50-GHz to 100-GHz interleaver. Relevant performance parameters such as insertion loss, channel uniformity, next-channel isolation (crosstalk) and integrated cross-talk are presented and discussed in contrast with the performance of other competing technologies such as Thin-Film-Filter-based Mux-Demux devices.

Quantum hacking on a practical continuous-variable quantum cryptosystem by inserting an external light

NASA Astrophysics Data System (ADS)

Qin, Hao; Kumar, Rupesh; Alleaume, Romain

2015-10-01

We report here a new side channel attack on a practical continuous-variable (CV) quantum key distribution (QKD) system. Inspired by blinding attack in discrete-variable QKD, we formalize an attack strategy by inserting an external light into a CV QKD system implemented Gaussian-modulated coherent state protocol and show that our attack can compromise its practical security. In this attack, we concern imperfections of a balanced homodyne detector used in CV QKD. According to our analysis, if one inserts an external light into Bob's signal port, due to the imperfect subtraction from the homodyne detector, the leakage of the external light contributes a displacement on the homodyne signal which causes detector electronics saturation. In consequence, Bob's quadrature measurement is not linear with the quadrature sent by Alice. By considering such vulnerability, a potential Eve can launch a full intercept-resend attack meanwhile she inserts an external light into Bob's signal port. By selecting proper properties of the external light, Eve actively controls the induced displacement value from the inserted light which results saturation of homodyne detection. In consequence, Eve can bias the excess noise due to the intercept-resend attack and the external light, such that Alice and Bob believe their excess noise estimation is below the null key threshold and they can still share a secret key. Our attack shows that the detector loopholes also exist in CV QKD, and it seems influence all the CV QKD systems using homodyne detection, since all the practical detectors have finite detection range.

Understanding the effect of locked nucleic acid and 2'-O-methyl modification on the hybridization thermodynamics of a miRNA-mRNA pair in the presence and absence of AfPiwi protein.

PubMed

Kumar, Santosh; Mapa, Koyeli; Maiti, Souvik

2014-03-18

miRNAs are some of the key epigenetic regulators of gene expression. They act through hybridization with their target mRNA and modulate the level of respective proteins via different mechanisms. Various cancer conditions are known to be associated with up- and downregulation of the oncogenic and tumor suppressor miRNAs, respectively. The levels of aberrantly expressed oncogenic miRNAs can be downregulated in different ways. Similarly, restoration of tumor suppressor miRNAs to their normal levels can be achieved using miRNA mimics. However, the use of miRNA mimics is limited by their reduced biostability and function. We have studied the hybridization thermodynamics of the miRNA 26a (11-mer, including the seed sequence) guide strand with the mRNA (11-mer) target strand in the absence and presence of AfPiwi protein. We have also inserted locked nucleic acids (LNAs) and 2'-O-methyl-modified nucleotides into the guide strand, in a walk-through manner, to assess their effect on the binding efficiency between guide and target RNA. Insertion of LNA and 2'-O-methyl-modified nucleotides into the guide strand helped to strengthen the binding affinity irrespective of the position of insertion. However, in the presence of AfPiwi protein, these modifications reduced the binding affinity to different extents depending on the position of insertion. Insertion of a modification leads to an increase in the enthalpic contribution with an increased unfavorable entropic contribution, which negatively compensates for the higher favorable enthalpy.

Electric-acoustic pitch comparisons in single-sided-deaf cochlear implant users: frequency-place functions and rate pitch.

PubMed

Schatzer, Reinhold; Vermeire, Katrien; Visser, Daniel; Krenmayr, Andreas; Kals, Mathias; Voormolen, Maurits; Van de Heyning, Paul; Zierhofer, Clemens

2014-03-01

Eight cochlear implant users with near-normal hearing in their non-implanted ear compared pitch percepts for pulsatile electric and acoustic pure-tone stimuli presented to the two ears. Six subjects were implanted with a 31-mm MED-EL FLEX(SOFT) electrode, and two with a 24-mm medium (M) electrode, with insertion angles of the most apical contacts ranging from 565° to 758°. In the first experiment, frequency-place functions were derived from pure-tone matches to 1500-pps unmodulated pulse trains presented to individual electrodes and compared to Greenwood's frequency position map along the organ of Corti. While the overall median downward shift of the obtained frequency-place functions (-0.16 octaves re. Greenwood) and the mean shifts in the basal (<240°; -0.33 octaves) and middle (-0.35 octaves) regions were statistically significant, the shift in the apical region (>480°; 0.26 octaves) was not. Standard deviations of frequency-place functions were approximately half an octave at electrode insertion angles below 480°, increasing to an octave at higher angular locations while individual functions were gradually leveling off. In a second experiment, subjects matched the rates of unmodulated pulse trains presented to individual electrodes in the apical half of the array to low-frequency pure tones between 100 Hz and 450 Hz. The aim was to investigate the influence of electrode place on the salience of temporal pitch cues, for coding strategies that present temporal fine structure information via rate modulations on select apical channels. Most subjects achieved reliable matches to tone frequencies from 100 Hz to 300 Hz only on electrodes at angular insertion depths beyond 360°, while rate-matches to 450-Hz tones were primarily achieved on electrodes at shallower insertion angles. Only for electrodes in the second turn the average slopes of rate-pitch functions did not differ significantly from the pure-tone references, suggesting their use for the encoding of within-channel fine frequency information via rate modulations in temporal fine structure stimulation strategies. Copyright © 2013 Elsevier B.V. All rights reserved.

KSC-98pc1038

NASA Image and Video Library

1998-09-04

Workers watch as the Hubble Space Telescope Orbiting Systems Test (HOST)is lowered onto a workstand in the Space Shuttle Processing Facility. To the right can be seen the Rack Insertion Device and Leonardo, a Multi-Purpose Logistics Module. The HOST platform, one of the payloads on the STS-95 mission, is carrying four experiments to validate components planned for installation during the third Hubble Space Telescope servicing mission and to evaluate new technologies in an earth orbiting environment. The STS-95 mission is scheduled to launch Oct. 29. It will carry three other payloads: the Spartan solar-observing deployable spacecraft, the International Extreme Ultraviolet Hitchhiker, and the SPACEHAB single module with experiments on space flight and the aging process

Orthoscopic real-image display of digital holograms.

PubMed

Makowski, P L; Kozacki, T; Zaperty, W

2017-10-01

We present a practical solution for the long-standing problem of depth inversion in real-image holographic display of digital holograms. It relies on a field lens inserted in front of the spatial light modulator device addressed by a properly processed hologram. The processing algorithm accounts for pixel size and wavelength mismatch between capture and display devices in a way that prevents image deformation. Complete images of large dimensions are observable from one position with a naked eye. We demonstrate the method experimentally on a 10-cm-long 3D object using a single full-HD spatial light modulator, but it can supplement most holographic displays designed to form a real image, including circular wide angle configurations.

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

Fakir, H.; Gaede, S.; Mulligan, M.

Purpose: To design a versatile, nonhomogeneous insert for the dose verification phantom ArcCHECK{sup Trade-Mark-Sign} (Sun Nuclear Corp., FL) and to demonstrate its usefulness for the verification of dose distributions in inhomogeneous media. As an example, we demonstrate it can be used clinically for routine quality assurance of two volumetric modulated arc therapy (VMAT) systems for lung stereotactic body radiation therapy (SBRT): SmartArc{sup Registered-Sign} (Pinnacle{sup 3}, Philips Radiation Oncology Systems, Fitchburg, WI) and RapidArc{sup Registered-Sign} (Eclipse{sup Trade-Mark-Sign }, Varian Medical Systems, Palo Alto, CA). Methods: The cylindrical detector array ArcCHECK{sup Trade-Mark-Sign} has a retractable homogeneous acrylic insert. In this work, wemore » designed and manufactured a customized heterogeneous insert with densities that simulate soft tissue, lung, bone, and air. The insert offers several possible heterogeneity configurations and multiple locations for point dose measurements. SmartArc{sup Registered-Sign} and RapidArc{sup Registered-Sign} plans for lung SBRT were generated and copied to ArcCHECK{sup Trade-Mark-Sign} for each inhomogeneity configuration. Dose delivery was done on a Varian 2100 ix linac. The evaluation of dose distributions was based on gamma analysis of the diode measurements and point doses measurements at different positions near the inhomogeneities. Results: The insert was successfully manufactured and tested with different measurements of VMAT plans. Dose distributions measured with the homogeneous insert showed gamma passing rates similar to our clinical results ({approx}99%) for both treatment-planning systems. Using nonhomogeneous inserts decreased the passing rates by up to 3.6% in the examples studied. Overall, SmartArc{sup Registered-Sign} plans showed better gamma passing rates for nonhomogeneous measurements. The discrepancy between calculated and measured point doses was increased up to 6.5% for the nonhomogeneous insert depending on the inhomogeneity configuration and measurement location. SmartArc{sup Registered-Sign} and RapidArc{sup Registered-Sign} plans had similar plan quality but RapidArc{sup Registered-Sign} plans had significantly higher monitor units (up to 70%). Conclusions: A versatile, nonhomogeneous insert was developed for ArcCHECK{sup Trade-Mark-Sign} for an easy and quick evaluation of dose calculations with nonhomogeneous media and for comparison of different treatment planning systems. The device was tested for SmartArc{sup Registered-Sign} and RapidArc{sup Registered-Sign} plans for lung SBRT, showing the uncertainties of dose calculations with inhomogeneities. The new insert combines the convenience of the ArcCHECK{sup Trade-Mark-Sign} and the possibility of assessing dose distributions in inhomogeneous media.« less

Antimultipath communication by injecting tone into null in signal spectrum

NASA Technical Reports Server (NTRS)

Davarian, Faramaz (Inventor)

1987-01-01

A transmitter for digital radio communication creates a null by balanced encoding of data modulated on an RF carrier, and inserts a calibration tone within the null. This is accomplished by having the calibration tone coincide in phase and frequency with the transmitted radio frequency output, for coherent demodulation of data at the receiver where the tone calibration signal is extracted and used for multipath fading compensation.

Membrane and Protein Interactions of the Pleckstrin Homology Domain Superfamily

PubMed Central

Lenoir, Marc; Kufareva, Irina; Abagyan, Ruben; Overduin, Michael

2015-01-01

The human genome encodes about 285 proteins that contain at least one annotated pleckstrin homology (PH) domain. As the first phosphoinositide binding module domain to be discovered, the PH domain recruits diverse protein architectures to cellular membranes. PH domains constitute one of the largest protein superfamilies, and have diverged to regulate many different signaling proteins and modules such as Dbl homology (DH) and Tec homology (TH) domains. The ligands of approximately 70 PH domains have been validated by binding assays and complexed structures, allowing meaningful extrapolation across the entire superfamily. Here the Membrane Optimal Docking Area (MODA) program is used at a genome-wide level to identify all membrane docking PH structures and map their lipid-binding determinants. In addition to the linear sequence motifs which are employed for phosphoinositide recognition, the three dimensional structural features that allow peripheral membrane domains to approach and insert into the bilayer are pinpointed and can be predicted ab initio. The analysis shows that conserved structural surfaces distinguish which PH domains associate with membrane from those that do not. Moreover, the results indicate that lipid-binding PH domains can be classified into different functional subgroups based on the type of membrane insertion elements they project towards the bilayer. PMID:26512702

Space Station and Shuttle Payloads: Rack Insertion Device Pneumatic Assembly Setup and Test

NASA Technical Reports Server (NTRS)

Conde, Nathan

2007-01-01

As part of my KSC summer internship, I was given the very cool task of writing a test preparation sheet (TPS). A TPS is a set of instructions for certain procedures or tasks, and serves as the documentation for the tasks. TPSs guide task leaders and technicians throughout the work procedures, safely, informing them of what steps will be hazardous, what precautions must be taken, and what to do in the case of an accident or emergency. I was placed in Boeing's Resupply & Return Division (R&R). R&R is responsible for sending up food and supplies to the International Space Station (ISS) with the use of three Italian Multi Purpose Logistics Modules - Leonardo, Donatello, and Raffaello. The supplies are loaded into Resupply Stowage Racks (RSRs) or Resupply Stowage Platforms (RSPs) (though, both are usually referred to as racks), depending on their size and shape. These racks are loaded into the modules with the help of a specialized crane known as the Rack Insertion Device (RID). The RID rests on four pneumatic air jacks, these allow for an operator to raise or lower the RID. The pneumatic air system supplies the air jacks with the necessary air pressure required to lift the RID.

Source characteristics and design consideration for an iron-free variable-period/polarizing undulator for the UV/VUV range on SPEAR (abstract)

NASA Astrophysics Data System (ADS)

Tatchyn, Roman

1992-01-01

Insertion devices that are tuned by electrical period variation are particularly suited for the design of flexible polarized-light sources [R. Tatchyn, J. Appl. Phys. 65, 4107 (1989); R. Tatchyn and T. Cremer, IEEE Trans. Mag. 26, 3102 (1990)]. Important advantages vis-a-vis mechanical or hybrid variable field designs include: (1) significantly more rapid modulation of both polarization and energy, (2) an inherently larger set of polarization modulation capabilities and (3) polarization/energy modulation at continuously optimized values of K. In this paper we outline some of the general considerations that enter into the design of hysteresis-free variable-period/polarizing undulator structures and present the parameters of a recently-completed prototype design capable of generating intense levels of UV/VUV photon flux on SPEAR running at 3 GeV.

Large size self-assembled quantum rings: quantum size effect and modulation on the surface diffusion.

PubMed

Tong, Cunzhu; Yoon, Soon Fatt; Wang, Lijun

2012-09-24

We demonstrate experimentally the submicron size self-assembled (SA) GaAs quantum rings (QRs) by quantum size effect (QSE). An ultrathin In0.1 Ga0.9As layer with different thickness is deposited on the GaAs to modulate the surface nucleus diffusion barrier, and then the SA QRs are grown. It is found that the density of QRs is affected significantly by the thickness of inserted In0.1 Ga0.9As, and the diffusion barrier modulation reflects mainly on the first five monolayer . The physical mechanism behind is discussed. The further analysis shows that about 160 meV decrease in diffusion barrier can be achieved, which allows the SA QRs with density of as low as one QR per 6 μm2. Finally, the QRs with diameters of 438 nm and outer diameters of 736 nm are fabricated using QSE.

High-efficiency W-band hybrid integrated photoreceiver module using UTC-PD and pHEMT amplifier

NASA Astrophysics Data System (ADS)

Umezawa, T.; Katshima, K.; Kanno, A.; Akahane, K.; Matsumoto, A.; Yamamoto, N.; Kawanishi, T.

2016-02-01

A 100-GHz narrowband photoreceiver module integrated with a zero-bias operational uni-traveling-carrier photodiode (UTC-PD) and a GaAs-based pseudomorphic high-electron-mobility transistor (pHEMT) amplifier was fabricated and characterized. Both devices exhibited flat frequency response and outstanding overall performance. The UTC-PD showed a 3-dB bandwidth beyond 110 GHz while the pHEMT amplifier featured low power consumption and a gain of 24 dB over the 85-100 GHz range. A butterfly metal package equipped with a 1.0 mm (W) coaxial connector and a microstrip-coplanar waveguide conversion substrate was designed for low insertion loss and low return loss. The fabricated photoreceiver module demonstrated high conversion gain, a maximum output power of +9.5 dBm at 96 GHz, and DC-power consumption of 0.21 W.

Artist concept illustrating key events on day by day basis during Apollo 9

NASA Technical Reports Server (NTRS)

1969-01-01

Artist concept illustrating key events on day by day basis during Apollo 9 mission. First photograph illustrates activities on the first day of the mission, including flight crew preparation, orbital insertion, 103 north mile orbit, separations, docking and docked Service Propulsion System Burn (19792); Second day events include landmark tracking, pitch maneuver, yaw-roll maneuver, and high apogee orbits (19793); Third day events include crew transfer and Lunar Module system evaluation (19794); Fourth day events include use of camera, day-night extravehicular activity, use of golden slippers, and television over Texas and Louisiana (19795); Fifth day events include vehicles undocked, Lunar Module burns for rendezvous, maximum separation, ascent propulsion system burn, formation flying and docking, and Lunar Module jettison ascent burn (19796); Sixth thru ninth day events include service propulsion system burns and landmark sightings, photograph special tests (19797); Tenth day events i

Non-reciprocal optical mirrors based on spatio-temporal acousto-optic modulation

NASA Astrophysics Data System (ADS)

Fleury, R.; Sounas, D. L.; Alù, A.

2018-03-01

Here, we investigate a scheme to realize free-space isolators and highly non-reciprocal mirrors with weak modulation imparted by an acoustic wave. We propose a strategy to dramatically break time-reversal symmetry by exploiting resonant interactions between a travelling acoustic wave and highly resonant Fabry-Pérot modes, inducing total reflection of an optical beam at a given angle, and no reflection at the negative angle. Different from conventional acousto-optic isolators, which are based on non-resonant frequency conversion and filtering, our proposal operates at the frequency of the optical signal by tailoring the resonant properties of the structure as well as the acoustic wave frequency and intensity, enabling 50 dB isolation with modest modulation requirements. Operation in the reflection mode allows for close-to-zero insertion loss, enabling disruptive opportunities in our ability to control and manipulate photons.

High resolution PET breast imager with improved detection efficiency

DOEpatents

Majewski, Stanislaw

2010-06-08

A highly efficient PET breast imager for detecting lesions in the entire breast including those located close to the patient's chest wall. The breast imager includes a ring of imaging modules surrounding the imaged breast. Each imaging module includes a slant imaging light guide inserted between a gamma radiation sensor and a photodetector. The slant light guide permits the gamma radiation sensors to be placed in close proximity to the skin of the chest wall thereby extending the sensitive region of the imager to the base of the breast. Several types of photodetectors are proposed for use in the detector modules, with compact silicon photomultipliers as the preferred choice, due to its high compactness. The geometry of the detector heads and the arrangement of the detector ring significantly reduce dead regions thereby improving detection efficiency for lesions located close to the chest wall.

3D silicon neural probe with integrated optical fibers for optogenetic modulation.

PubMed

Kim, Eric G R; Tu, Hongen; Luo, Hao; Liu, Bin; Bao, Shaowen; Zhang, Jinsheng; Xu, Yong

2015-07-21

Optogenetics is a powerful modality for neural modulation that can be useful for a wide array of biomedical studies. Penetrating microelectrode arrays provide a means of recording neural signals with high spatial resolution. It is highly desirable to integrate optics with neural probes to allow for functional study of neural tissue by optogenetics. In this paper, we report the development of a novel 3D neural probe coupled simply and robustly to optical fibers using a hollow parylene tube structure. The device shanks are hollow tubes with rigid silicon tips, allowing the insertion and encasement of optical fibers within the shanks. The position of the fiber tip can be precisely controlled relative to the electrodes on the shank by inherent design features. Preliminary in vivo rat studies indicate that these devices are capable of optogenetic modulation simultaneously with 3D neural signal recording.

Biomedical Wireless Ambulatory Crew Monitor

NASA Technical Reports Server (NTRS)

Chmiel, Alan; Humphreys, Brad

2009-01-01

A compact, ambulatory biometric data acquisition system has been developed for space and commercial terrestrial use. BioWATCH (Bio medical Wireless and Ambulatory Telemetry for Crew Health) acquires signals from biomedical sensors using acquisition modules attached to a common data and power bus. Several slots allow the user to configure the unit by inserting sensor-specific modules. The data are then sent real-time from the unit over any commercially implemented wireless network including 802.11b/g, WCDMA, 3G. This system has a distributed computing hierarchy and has a common data controller on each sensor module. This allows for the modularity of the device along with the tailored ability to control the cards using a relatively small master processor. The distributed nature of this system affords the modularity, size, and power consumption that betters the current state of the art in medical ambulatory data acquisition. A new company was created to market this technology.

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

Sberro, Hila; Leavitt, Azita; Kiro, Ruth

Toxin-antitoxin (TA) modules, composed of a toxic protein and a counteracting antitoxin, play important roles in bacterial physiology. We examined the experimental insertion of 1.5 million genes from 388 microbial genomes into an Escherichia coli host using over 8.5 million random clones. This revealed hundreds of genes (toxins) that could only be cloned when the neighboring gene (antitoxin) was present on the same clone. Clustering of these genes revealed TA families widespread in bacterial genomes, some of which deviate from the classical characteristics previously described for such modules. Introduction of these genes into E. coli validated that the toxin toxicitymore » is mitigated by the antitoxin. Infection experiments with T7 phage showed that two of the new modules can provide resistance against phage. Moreover, our experiments revealed an 'anti-defense' protein in phage T7 that neutralizes phage resistance. Our results expose active fronts in the arms race between bacteria and phage.« less

Novel mutants of Erwinia carotovora subsp. carotovora defective in the production of plant cell wall degrading enzymes generated by Mu transpososome-mediated insertion mutagenesis.

PubMed

Laasik, Eve; Ojarand, Merli; Pajunen, Maria; Savilahti, Harri; Mäe, Andres

2005-02-01

As in Erwinia carotovora subsp. carotovora the regulation details of the main virulence factors, encoding extracellular enzymes that degrade the plant cell wall, is only rudimentally understood, we performed a genetic screen to identify novel candidate genes involved in the process. Initially, we used Mu transpososome-mediated mutagenesis approach to generate a comprehensive transposon insertion mutant library of ca. 10000 clones and screened the clones for the loss of extracellular enzyme production. Extracellular enzymes production was abolished by mutations in the chromosomal helEcc, trkAEcc yheLEcc, glsEcc, igaAEcc and cysQEcc genes. The findings reported here demonstrate that we have isolated six new representatives that belong to the pool of genes modulating the production of virulence factors in E. carotovora.

Role of Transmembrane Potential and Defects on the Permeabilization of Lipid Bilayers by Alamethicin, an Ion-Channel-Forming Peptide.

PubMed

Su, ZhangFei; Shodiev, Muzaffar; Leitch, J Jay; Abbasi, Fatemeh; Lipkowski, Jacek

2018-05-29

The insertion and ion-conducting channel properties of alamethicin reconstituted into a 1,2-di- O-phytanyl- sn-glycero-3-phosphocholine bilayer floating on the surface of a gold (111) electrode modified with a 1-thio-β-d-glucose (β-Tg) self-assembled monolayer were investigated using a combination of electrochemical impedance spectroscopy (EIS) and polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS). The hydrophilic β-Tg monolayer separated the bilayer from the gold substrate and created a water-rich spacer region, which better represents natural cell membranes. The EIS measurements acquired information about the membrane resistivity (a measure of membrane porosity), and the PM-IRRAS experiments provided insight into the conformation and orientation of the membrane constituents as a function of the transmembrane potential. The results showed that the presence of alamethicin had a small effect on the conformation and orientation of phospholipid molecules within the bilayer for all studied potentials. In contrast, the alamethicin peptides assumed a surface state, where the helical axes adopted a large tilt angle with respect to the surface normal, at small transmembrane potentials, and inserted into the bilayer at sufficiently negative transmembrane potentials forming pores, which behaved as barrel-stave ion channels for ionic transport across the membrane. The results indicated that insertion of alamethincin peptides into the bilayer was driven by the dipole-field interactions and that the transitions between the inserted and surface states were electrochemically reversible. Additionally, the EIS measurements performed on phospholipid bilayers without alamethicin also showed that the application of negative transmembrane potentials introduces defects into the bilayer. The membrane resistances measured in both the absence and presence of alamethicin show similar dependencies on the electrode potential, suggesting that the insertion of the peptide may also be assisted by the electroporation of the membrane. The findings in this study provide new insights into the mechanism of alamethicin insertion into phospholipid bilayers.

Gigahertz speed operation of epsilon-near-zero silicon photonic modulators

DOE PAGES

Wood, Michael G.; Campione, Salvatore; Parameswaran, S.; ...

2018-02-21

Opmore » tical communication systems increasingly require electro-optical modulators that deliver high modulation speeds across a large optical bandwidth with a small device footprint and a CMOS-compatible fabrication process. Although silicon photonic modulators based on transparent conducting oxides (TCOs) have shown promise for delivering on these requirements, modulation speeds to date have been limited. Here, we describe the design, fabrication, and performance of a fast, compact electroabsorption modulator based on TCOs. The modulator works by using bias voltage to increase the carrier density in the conducting oxide, which changes the permittivity and hence optical attenuation by almost 10 dB. Under bias, light is tightly confined to the conducting oxide layer through nonresonant epsilon-near-zero (ENZ) effects, which enable modulation over a broad range of wavelengths in the telecommunications band. Our approach features simple integration with passive silicon waveguides, the use of stable inorganic materials, and the ability to modulate both transverse electric and magnetic polarizations with the same device design. Using a 4-μm-long modulator and a drive voltage of 2 V p p , we demonstrate digital modulation at rates of 2.5 Gb/s. We report broadband operation with a 6.5 dB extinction ratio across the 1530–1590 nm band and a 10 dB insertion loss. This work verifies that high-speed ENZ devices can be created using conducting oxide materials and paves the way for additional technology development that could have a broad impact on future optical communications systems.« less

Gigahertz speed operation of epsilon-near-zero silicon photonic modulators

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

Wood, Michael G.; Campione, Salvatore; Parameswaran, S.

Opmore » tical communication systems increasingly require electro-optical modulators that deliver high modulation speeds across a large optical bandwidth with a small device footprint and a CMOS-compatible fabrication process. Although silicon photonic modulators based on transparent conducting oxides (TCOs) have shown promise for delivering on these requirements, modulation speeds to date have been limited. Here, we describe the design, fabrication, and performance of a fast, compact electroabsorption modulator based on TCOs. The modulator works by using bias voltage to increase the carrier density in the conducting oxide, which changes the permittivity and hence optical attenuation by almost 10 dB. Under bias, light is tightly confined to the conducting oxide layer through nonresonant epsilon-near-zero (ENZ) effects, which enable modulation over a broad range of wavelengths in the telecommunications band. Our approach features simple integration with passive silicon waveguides, the use of stable inorganic materials, and the ability to modulate both transverse electric and magnetic polarizations with the same device design. Using a 4-μm-long modulator and a drive voltage of 2 V p p , we demonstrate digital modulation at rates of 2.5 Gb/s. We report broadband operation with a 6.5 dB extinction ratio across the 1530–1590 nm band and a 10 dB insertion loss. This work verifies that high-speed ENZ devices can be created using conducting oxide materials and paves the way for additional technology development that could have a broad impact on future optical communications systems.« less

Characterization of real objects by an active electrolocation sensor

NASA Astrophysics Data System (ADS)

Metzen, Michael G.; Al Ghouz, Imène; Krueger, Sandra; Bousack, Herbert; von der Emde, Gerhard

2012-04-01

Weakly electric fish use a process called 'active electrolocation' to orientate in their environment and to localize objects based on their electrical properties. To do so, the fish discharge an electric organ which emits brief electrical current pulses (electric organ discharge, EOD) and in return sense the generated electric field which builds up surrounding the animal. Caused by the electrical properties of nearby objects, fish measure characteristic signal modulations with an array of electroreceptors in their skin. The fish are able to gain important information about the geometrical properties of an object as well as its complex impedance and its distance. Thus, active electrolocation is an interesting feature to be used in biomimetic approaches. We used this sensory principle to identify different insertions in the walls of Plexiglas tubes. The insertions tested were composed of aluminum, brass and graphite in sizes between 3 and 20 mm. A carrier signal was emitted and perceived with the poles of a commercial catheter for medical diagnostics. Measurements were performed with the poles separated by 6.3 to 55.3 mm. Depending on the length of the insertion in relation to the sender-receiver distance, we observed up to three peaks in the measured electric images. The first peak was affected by the material of the insertion, while the distance between the second and third peak strongly correlated with the length of the insertion. In a second experiment we tested whether various materials could be detected by using signals of different frequency compositions. Based on their electric images we were able to discriminate between objects having different resistive properties, but not between objects of complex impedances.

Megagauss Fields during Milliseconds

NASA Astrophysics Data System (ADS)

Campbell, L. J.; Embury, D.; Han, K.; Parkin, D. M.; Baca, A. G.; Kihara, K. H.; Sims, J. R.; Boebinger, G.; Eyssa, Y.; Lesch, B.; Li, L.; Schillig, J.; Schneider-Muntau, H.; Walsh, R.

2004-11-01

A non-destructive, one megagauss magnet is now being designed in cooperation between the Los Alamos National Laboratory and the National High Magnetic Field Laboratory (NHMFL) through joint funding by the US Department of Energy and the US National Science Foundation. The design combines two types of pulsed magnet now in use at the NHMFL: a capacitor-driven `insert' magnet with a total pulse width of order 10 ms and a much larger `outsert' magnet with a total pulse width of order 2 seconds that is driven by a controlled power source. The insert and outsert produce approximately 1/2 megagauss each. Although the design uses CuAg as the principal conductor, further design efforts and materials development involve exploring CuNb and stainless steel-clad copper as possible future alternatives. A crucial innovation employed wound steel strip (sheet) as reinforcement in both insert and outsert coils. This gives extra strength due to the higher degree of cold-work possible in strip materials. A key role is played by materials development for this leading edge magnet. A major component, the 7-module, 560 MVA controlled dc power supply required for the outsert has been installed and commissioned.

The Influence of the Inner Topology of Cooling Units on the Performance of Automotive Exhaust-Based Thermoelectric Generators

NASA Astrophysics Data System (ADS)

Zhu, D. C.; Su, C. Q.; Deng, Y. D.; Wang, Y. P.; Liu, X.

2017-11-01

Automotive exhaust-based thermoelectric generators are currently a hot topic in energy recovery. The waste heat of automotive exhaust gas can be converted into electricity by means of thermoelectric modules. Generally, inserting fins into the cooling unit contributes to enhancing the heat transfer for a higher power output. However, the introduction of fins will result in a pressure drop in the cooling system. In current research, in order to enhance the heat transfer and avoid a large pressure drop, a cooling unit with cylindrical grooves on the interior surface was proposed. To evaluate the performance of the cylindrical grooves, different inner topologies, including a smooth interior surface,a smooth interior surface with inserted fins and an interior surface with cylindrical grooves, were compared. The results revealed that compared with the smooth interior surface, the smooth interior surface with inserted fins and the interior surface with cylindrical grooves both enhanced the heat transfer, but the interior surface with cylindrical grooves obtained a lower pressure drop. To improve the performance of the cylindrical grooves, different groove-depth ratios were tried, and the results showed that a groove-depth ratio of 0.081 could provide the best overall performance.

Image reconstruction and system modeling techniques for virtual-pinhole PET insert systems

PubMed Central

Keesing, Daniel B; Mathews, Aswin; Komarov, Sergey; Wu, Heyu; Song, Tae Yong; O'Sullivan, Joseph A; Tai, Yuan-Chuan

2012-01-01

Virtual-pinhole PET (VP-PET) imaging is a new technology in which one or more high-resolution detector modules are integrated into a conventional PET scanner with lower-resolution detectors. It can locally enhance the spatial resolution and contrast recovery near the add-on detectors, and depending on the configuration, may also increase the sensitivity of the system. This novel scanner geometry makes the reconstruction problem more challenging compared to the reconstruction of data from a standalone PET scanner, as new techniques are needed to model and account for the non-standard acquisition. In this paper, we present a general framework for fully 3D modeling of an arbitrary VP-PET insert system. The model components are incorporated into a statistical reconstruction algorithm to estimate an image from the multi-resolution data. For validation, we apply the proposed model and reconstruction approach to one of our custom-built VP-PET systems – a half-ring insert device integrated into a clinical PET/CT scanner. Details regarding the most important implementation issues are provided. We show that the proposed data model is consistent with the measured data, and that our approach can lead to reconstructions with improved spatial resolution and lesion detectability. PMID:22490983

The Influence of the Inner Topology of Cooling Units on the Performance of Automotive Exhaust-Based Thermoelectric Generators

NASA Astrophysics Data System (ADS)

Zhu, D. C.; Su, C. Q.; Deng, Y. D.; Wang, Y. P.; Liu, X.

2018-06-01

Automotive exhaust-based thermoelectric generators are currently a hot topic in energy recovery. The waste heat of automotive exhaust gas can be converted into electricity by means of thermoelectric modules. Generally, inserting fins into the cooling unit contributes to enhancing the heat transfer for a higher power output. However, the introduction of fins will result in a pressure drop in the cooling system. In current research, in order to enhance the heat transfer and avoid a large pressure drop, a cooling unit with cylindrical grooves on the interior surface was proposed. To evaluate the performance of the cylindrical grooves, different inner topologies, including a smooth interior surface,a smooth interior surface with inserted fins and an interior surface with cylindrical grooves, were compared. The results revealed that compared with the smooth interior surface, the smooth interior surface with inserted fins and the interior surface with cylindrical grooves both enhanced the heat transfer, but the interior surface with cylindrical grooves obtained a lower pressure drop. To improve the performance of the cylindrical grooves, different groove-depth ratios were tried, and the results showed that a groove-depth ratio of 0.081 could provide the best overall performance.

NMR investigations of molecular dynamics

NASA Astrophysics Data System (ADS)

Palmer, Arthur

2011-03-01

NMR spectroscopy is a powerful experimental approach for characterizing protein conformational dynamics on multiple time scales. The insights obtained from NMR studies are complemented and by molecular dynamics (MD) simulations, which provide full atomistic details of protein dynamics. Homologous mesophilic (E. coli) and thermophilic (T. thermophilus) ribonuclease H (RNase H) enzymes serve to illustrate how changes in protein sequence and structure that affect conformational dynamic processes can be monitored and characterized by joint analysis of NMR spectroscopy and MD simulations. A Gly residue inserted within a putative hinge between helices B and C is conserved among thermophilic RNases H, but absent in mesophilic RNases H. Experimental spin relaxation measurements show that the dynamic properties of T. thermophilus RNase H are recapitulated in E. coli RNase H by insertion of a Gly residue between helices B and C. Additional specific intramolecular interactions that modulate backbone and sidechain dynamical properties of the Gly-rich loop and of the conserved Trp residue flanking the Gly insertion site have been identified using MD simulations and subsequently confirmed by NMR spin relaxation measurements. These results emphasize the importance of hydrogen bonds and local steric interactions in restricting conformational fluctuations, and the absence of such interactions in allowing conformational adaptation to substrate binding.

Electro-optic modulation at 1.4 GHz using single-crystal film of DAST

NASA Astrophysics Data System (ADS)

Ahyi, Ayayi; Titus, Jitto; Thakur, Mrinal

2002-03-01

Electro-optic modulation at 4 kHz using single-crystal film of DAST has been recently reported.^1 The measurement was made in the transverse configuration with the light beam propagating perpendicular to the film while electric field was applied in the plane of the film - along the dipole axis. In this presentation, we will discuss results of electro-optic modulation in DAST single-crystal films at significantly higher speed (0.1 - 1.4 GHz). Single-crystal films of DAST with excellent optical quality were prepared by modified shear method. The electro-optic modulation was measured using the technique of field-induced birefringence and the signal was recorded by a spectrum analyzer. Light (λ = 750 nm) propagated perpendicular to the film (thickness ~ 3 μm). We have observed excellent signal-to-noise ratio at these high frequencies, along with a low insertion loss. The voltage we applied is only ~ 1 volt across a gap of 15 μm and the observed signal-to-noise ratio is comparable to that of guided-wave electro-optic modulators. 1. M. Thakur, J. Xu, A. Bhowmik and M. Thakur, Appl. Phys. Lett., 74 635

Space Launch System Co-Manifested Payload Options for Habitation

NASA Technical Reports Server (NTRS)

Smitherman, David

2015-01-01

The Space Launch System (SLS) has a co-manifested payload capability that will grow over time as the launch vehicle matures and planned upgrades are implemented. The final configuration is planned to be capable of inserting a payload greater than 10 metric tons (mt) into a trans-lunar injection trajectory along with the crew in the Orion capsule and its service module. The co-manifested payload is located below the Orion and its service module in a 10 m high fairing similar to the way the Saturn launch vehicle carried the lunar lander below the Apollo command and service modules. Various approaches that utilize this comanifested payload capability to build up infrastructure in deep space have been explored in support of future asteroid, lunar, and Mars mission scenarios. This paper reports on the findings of the Advanced Concepts Office study team at NASA Marshall Space Flight Center (MSFC) working with the Advanced Exploration Systems Program on the Exploration Augmentation Module Project. It includes some of the possible options for habitation in the co-manifested payload volume of the SLS. Findings include a set of module designs that can be developed in 10 mt increments to support these co-manifested payload missions along with a comparison of this approach to a large-module payload flight configuration for the SLS.

Laterally modulated excitation microscopy: improvement of resolution by using a diffraction grating

NASA Astrophysics Data System (ADS)

Heintzmann, Rainer; Cremer, Christoph G.

1999-01-01

High spatial frequencies in the illuminating light of microscopes lead to a shift of the object spatial frequencies detectable through the objective lens. If a suitable procedure is found for evaluation of the measured data, a microscopic image with a higher resolution than under flat illumination can be obtained. A simple method for generation of a laterally modulated illumination pattern is discussed here. A specially constructed diffraction grating was inserted in the illumination beam path at the conjugate object plane (position of the adjustable aperture) and projected through the objective into the object. Microscopic beads were imaged with this method and evaluated with an algorithm based on the structure of the Fourier space. The results indicate an improvement of resolution.

HOST payload for STS-95 being moved into SSPF

NASA Technical Reports Server (NTRS)

1998-01-01

Workers watch as the Hubble Space Telescope Orbiting Systems Test (HOST)is lowered onto a workstand in the Space Shuttle Processing Facility. To the right can be seen the Rack Insertion Device and Leonardo, a Multi-Purpose Logistics Module. The HOST platform, one of the payloads on the STS-95 mission, is carrying four experiments to validate components planned for installation during the third Hubble Space Telescope servicing mission and to evaluate new technologies in an earth orbiting environment. The STS-95 mission is scheduled to launch Oct. 29. It will carry three other payloads: the Spartan solar-observing deployable spacecraft, the International Extreme Ultraviolet Hitchhiker, and the SPACEHAB single module with experiments on space flight and the aging process.

A compact 10 kW solid-state RF power amplifier at 352 MHz

NASA Astrophysics Data System (ADS)

Dancila, Dragos; Hoang Duc, Long; Jobs, Magnus; Holmberg, Måns; Hjort, Adam; Rydberg, Anders; Ruber, Roger

2017-07-01

A compact 10 kW RF power amplifier at 352 MHz was developed at FREIA for the European Spallation Source, ESS. The specifications of ESS for the conception of amplifiers are related to its pulsed operation: 3.5 ms pulse length and a duty cycle of 5%. The realized amplifier is composed of eight kilowatt level modules, combined using a planar Gysel 8-way combiner. The combiner has a low insertion loss of only 0.2 dB, measured at 10 kW peak power. Each module is built around a commercially available LDMOS transistor in a singleended architecture. During the final tests, a total output peak power of 10.5 kW was measured.

Extending Single-Molecule Microscopy Using Optical Fourier Processing

PubMed Central

2015-01-01

This article surveys the recent application of optical Fourier processing to the long-established but still expanding field of single-molecule imaging and microscopy. A variety of single-molecule studies can benefit from the additional image information that can be obtained by modulating the Fourier, or pupil, plane of a widefield microscope. After briefly reviewing several current applications, we present a comprehensive and computationally efficient theoretical model for simulating single-molecule fluorescence as it propagates through an imaging system. Furthermore, we describe how phase/amplitude-modulating optics inserted in the imaging pathway may be modeled, especially at the Fourier plane. Finally, we discuss selected recent applications of Fourier processing methods to measure the orientation, depth, and rotational mobility of single fluorescent molecules. PMID:24745862

Development of 873 nm Raman Seed Pulse for Raman-seeded Laser Wakefield Acceleration

NASA Astrophysics Data System (ADS)

Grigsby, F.; Peng, D.; Downer, M. C.

2004-12-01

By using a Raman-shifted seed pulse coincident with a main driving pulse, laser wakefields can be generated with sub-relativistic intensity, coherent control and high repetition rate in the self-modulated regime. Experimentally, the generation of a chirped Stokes laser pulse by inserting a solid state Raman shifter, Ba(NO3)2, into a CPA system before the compressor (to suppress self-phase modulation) will be described. We will also report on design, modeling and experimental demonstration of a novel compressor for the Stokes pulse that uses a mismatched grating pair to achieve a near transform-limited seed pulse. Finally, we will describe the design, simulation and current status of Raman-seeded LWFA experiments that use this novel source.

Extending single-molecule microscopy using optical Fourier processing.

PubMed

Backer, Adam S; Moerner, W E

2014-07-17

This article surveys the recent application of optical Fourier processing to the long-established but still expanding field of single-molecule imaging and microscopy. A variety of single-molecule studies can benefit from the additional image information that can be obtained by modulating the Fourier, or pupil, plane of a widefield microscope. After briefly reviewing several current applications, we present a comprehensive and computationally efficient theoretical model for simulating single-molecule fluorescence as it propagates through an imaging system. Furthermore, we describe how phase/amplitude-modulating optics inserted in the imaging pathway may be modeled, especially at the Fourier plane. Finally, we discuss selected recent applications of Fourier processing methods to measure the orientation, depth, and rotational mobility of single fluorescent molecules.

Extravehicular Activity (EVA) 101: Constellation EVA Systems

NASA Technical Reports Server (NTRS)

Jordan, Nicole C.

2007-01-01

A viewgraph presentation on Extravehicular Activity (EVA) Systems is shown. The topics include: 1) Why do we need space suits? 2) Protection From the Environment; 3) Primary Life Support System (PLSS); 4) Thermal Control; 5) Communications; 6) Helmet and Extravehicular Visor Assy; 7) Hard Upper Torso (HUT) and Arm Assy; 8) Display and Controls Module (DCM); 9) Gloves; 10) Lower Torso Assembly (LTA); 11) What Size Do You Need?; 12) Boot and Sizing Insert; 13) Boot Heel Clip and Foot Restraint; 14) Advanced and Crew Escape Suit; 15) Nominal & Off-Nominal Landing; 16) Gemini Program (mid-1960s); 17) Apollo EVA on Service Module; 18) A Bold Vision for Space Exploration, Authorized by Congress; 19) EVA System Missions; 20) Configurations; 21) Reduced Gravity Program; and 22) Other Opportunities.

Impact of tube current modulation on lesion conspicuity index in hi-resolution chest computed tomography

NASA Astrophysics Data System (ADS)

Szczepura, Katy; Tomkinson, David; Manning, David

2017-03-01

Tube current modulation is a method employed in the use of CT in an attempt to optimize radiation dose to the patient. The acceptable noise (noise index) can be varied, based on the level of optimization required; higher accepted noise reduces the patient dose. Recent research [1] suggests that measuring the conspicuity index (C.I.) of focal lesions within an image is more reflective of a clinical reader's ability to perceive focal lesions than traditional physical measures such as contrast to noise (CNR) and signal to noise ratio (SNR). Software has been developed and validated to calculate the C.I. in DICOM images. The aim of this work is assess the impact of tube current modulation on conspicuity index and CTDIvol, to indicate the benefits and limitations of tube current modulation on lesion detectability. Method An anthropomorphic chest phantom was used "Lungman" with inserted lesions of varying size and HU (see table below) a range of Hounsfield units and sizes were used to represent the variation in lesion Hounsfield units found. This meant some lesions had negative Hounsfield unit values.

Ka-Band MMIC Subarray Technology Program (Ka-Mist)

NASA Technical Reports Server (NTRS)

Pottinger, W.

1995-01-01

Ka-band monolithic microwave integrated circuit (MMIC) arrays have been considered as having high potential for increasing the capability of space, aircraft, and land mobile communication systems in terms of scan performance, data rate, link margin, and flexibility while offering a significant reduction in size, weight, and power consumption. Insertion of MMIC technology into antenna systems, particularly at millimeter wave frequencies using low power and low noise amplifiers in closed proximity to the radiating elements, offers a significant improvement in the array transmit efficiency, receive system noise figure, and overall array reliability. Application of active array technology also leads to the use of advanced beamforming techniques that can improve beam agility, diversity, and adaptivity to complex signal environments. The objective of this program was to demonstrate the technical feasibility of the 'tile' array packaging architecture at EHF via the insertion of 1990 MMIC technology into a functional tile array or subarray module. The means test of this objective was to demonstrate and deliver to NASA a minimum of two 4 x 4 (16 radiating element) subarray modules operating in a transmit mode at 29.6 GHz. Available (1990) MMIC technology was chosen to focus the program effort on the novel interconnect schemes and packaging requirements rather than focusing on MMIC development. Major technical achievements of this program include the successful integration of two 4 x 4 subarray modules into a single antenna array. This 32 element array demonstrates a transmit EIRP of over 300 watts yielding an effective directive power gain in excess of 55 dB at 29.63 GHz. The array has been actively used as the transmit link in airborne/terrestrial mobile communication experiments accomplished via the ACTS satellite launched in August 1993.

Silicon optical modulators for optical digital and analog communications (Conference Presentation)

NASA Astrophysics Data System (ADS)

Yang, Lin; Ding, Jianfeng; Zhang, Lei; Shao, Sizu

2017-02-01

Silicon photonics is considered as a promising technology to overcome the difficulties of the existing digital and analog optical communication systems, such as low integration, high cost, and high power consumption. Silicon optical modulator, as a component to transfer data from electronic domain to optical one, has attracted extensive attentions in the past decade. In this paper, we review the statuses of the silicon optical modulators for digital and analog optical communications and introduce our efforts on these topics. We analyze the relationship between the performance and the structural parameters of the silicon optical modulator and present how to optimize its performance including electro-optical bandwidth, modulation efficiency, optical bandwidth and insertion loss. The fabricated silicon optical modulator has an electro-optical bandwidth of 30 GHz. Its extinction ratios are 14.0 dB, 11.2 dB and 9.0 dB at the speeds of 40 Gbps, 50 Gbps and 64 Gbps for OOK modulation. The high extinction ratio of the silicon optical modulator at the high speed makes it very appropriate for the application of optical coherent modulation, such as QPSK and 16-QAM. The fabricated silicon optical modulator also can be utilized for analog optical communication. With respect to a noise floor of -165 dBc, the dynamic ranges for the second-order harmonic and the third-order intermodulation distortion are 90.8 dB and 110.5 dB respectively. By adopting a differential driving structure, the dynamic range for the second-order harmonic can be further improved to 100.0 dB while the third-order intermodulation distortion remains the same level.

Lunar Orbit Insertion Targeting and Associated Outbound Mission Design for Lunar Sortie Missions

NASA Technical Reports Server (NTRS)

Condon, Gerald L.

2007-01-01

This report details the Lunar Orbit Insertion (LOI) arrival targeting and associated mission design philosophy for Lunar sortie missions with up to a 7-day surface stay and with global Lunar landing site access. It also documents the assumptions, methodology, and requirements validated by TDS-04-013, Integrated Transit Nominal and Abort Characterization and Sensitivity Study. This report examines the generation of the Lunar arrival parking orbit inclination and Longitude of the Ascending Node (LAN) targets supporting surface missions with global Lunar landing site access. These targets support the Constellation Program requirement for anytime abort (early return) by providing for a minimized worst-case wedge angle [and an associated minimum plane change delta-velocity (V) cost] between the Crew Exploration Vehicle (CEV) and the Lunar Surface Access Module (LSAM) for an LSAM launch anytime during the Lunar surface stay.

Modular jet impingement assemblies with passive and active flow control for electronics cooling

DOEpatents

Zhou, Feng; Dede, Ercan Mehmet; Joshi, Shailesh

2016-09-13

Power electronics modules having modular jet impingement assembly utilized to cool heat generating devices are disclosed. The modular jet impingement assemblies include a modular manifold having a distribution recess, one or more angled inlet connection tubes positioned at an inlet end of the modular manifold that fluidly couple the inlet tube to the distribution recess and one or more outlet connection tubes positioned at an outlet end of the modular manifold that fluidly coupling the outlet tube to the distribution recess. The modular jet impingement assemblies include a manifold insert removably positioned within the distribution recess and include one or more inlet branch channels each including an impinging slot and one or more outlet branch channels each including a collecting slot. Further a heat transfer plate coupled to the modular manifold, the heat transfer plate comprising an impingement surface including an array of fins that extend toward the manifold insert.

High efficiency and enhanced ESD properties of UV LEDs by inserting p-GaN/p-AlGaN superlattice

NASA Astrophysics Data System (ADS)

Huang, Yong; Li, PeiXian; Yang, Zhuo; Hao, Yue; Wang, XiaoBo

2014-05-01

Significantly improved electrostatic discharge (ESD) properties of InGaN/GaN-based UV light-emitting diode (LED) with inserting p-GaN/p-AlGaN superlattice (p-SLs) layers (instead of p-AlGaN single layer) between multiple quantum wells and Mg-doped GaN layer are reported. The pass yield of the LEDs increased from 73.53% to 93.81% under negative 2000 V ESD pulses. In addition, the light output power (LOP) and efficiency droop at high injection current were also improved. The mechanism of the enhanced ESD properties was then investigated. After excluding the effect of capacitance modulation, high-resolution X-ray diffraction (XRD) and atomic force microscope (AFM) measurements demonstrated that the dominant mechanism of the enhanced ESD properties is the material quality improved by p-SLs, which indicated less leakage paths, rather than the current spreading improved by p-SLs.

A new FPGA architecture suitable for DSP applications

NASA Astrophysics Data System (ADS)

Liyun, Wang; Jinmei, Lai; Jiarong, Tong; Pushan, Tang; Xing, Chen; Xueyan, Duan; Liguang, Chen; Jian, Wang; Yuan, Wang

2011-05-01

A new FPGA architecture suitable for digital signal processing applications is presented. DSP modules can be inserted into FPGA conveniently with the proposed architecture, which is much faster when used in the field of digital signal processing compared with traditional FPGAs. An advanced 2-level MUX (multiplexer) is also proposed. With the added SLEEP MODE PASS to traditional 2-level MUX, static leakage is reduced. Furthermore, buffers are inserted at early returns of long lines. With this kind of buffer, the delay of the long line is improved by 9.8% while the area increases by 4.37%. The layout of this architecture has been taped out in standard 0.13 μm CMOS technology successfully. The die size is 6.3 × 4.5 mm2 with the QFP208 package. Test results show that performances of presented classical DSP cases are improved by 28.6%-302% compared with traditional FPGAs.

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

Bierhuizen, Serge J.; Wang, Nanze Patrick; Eng, Gregory W.

An array of housings with housing bodies and lenses is molded, or an array of housing bodies is molded and bonded with lenses to form an array of housings with housing bodies and lenses. Light-emitting diodes (LEDs) are attached to the housings in the array. An array of metal pads may be bonded to the back of the array or insert molded with the housing array to form bond pads on the back of the housings. The array is singulated to form individual LED modules.

An allele of the crm gene blocks cyanobacterial circadian rhythms.

PubMed

Boyd, Joseph S; Bordowitz, Juliana R; Bree, Anna C; Golden, Susan S

2013-08-20

The SasA-RpaA two-component system constitutes a key output pathway of the cyanobacterial Kai circadian oscillator. To date, rhythm of phycobilisome associated (rpaA) is the only gene other than kaiA, kaiB, and kaiC, which encode the oscillator itself, whose mutation causes completely arrhythmic gene expression. Here we report a unique transposon insertion allele in a small ORF located immediately upstream of rpaA in Synechococcus elongatus PCC 7942 termed crm (for circadian rhythmicity modulator), which results in arrhythmic promoter activity but does not affect steady-state levels of RpaA. The crm ORF complements the defect when expressed in trans, but only if it can be translated, suggesting that crm encodes a small protein. The crm1 insertion allele phenotypes are distinct from those of an rpaA null; crm1 mutants are able to grow in a light:dark cycle and have no detectable oscillations of KaiC phosphorylation, whereas low-amplitude KaiC phosphorylation rhythms persist in the absence of RpaA. Levels of phosphorylated RpaA in vivo measured over time are significantly altered compared with WT in the crm1 mutant as well as in the absence of KaiC. Taken together, these results are consistent with the hypothesis that the Crm polypeptide modulates a circadian-specific activity of RpaA.

Modulation of the functional association between the HIV-1 intasome and the nucleosome by histone amino-terminal tails.

PubMed

Benleulmi, Mohamed S; Matysiak, Julien; Robert, Xavier; Miskey, Csaba; Mauro, Eric; Lapaillerie, Delphine; Lesbats, Paul; Chaignepain, Stéphane; Henriquez, Daniel R; Calmels, Christina; Oladosu, Oyindamola; Thierry, Eloïse; Leon, Oscar; Lavigne, Marc; Andreola, Marie-Line; Delelis, Olivier; Ivics, Zoltán; Ruff, Marc; Gouet, Patrice; Parissi, Vincent

2017-11-28

Stable insertion of the retroviral DNA genome into host chromatin requires the functional association between the intasome (integrase·viral DNA complex) and the nucleosome. The data from the literature suggest that direct protein-protein contacts between integrase and histones may be involved in anchoring the intasome to the nucleosome. Since histone tails are candidates for interactions with the incoming intasomes we have investigated whether they could participate in modulating the nucleosomal integration process. We show here that histone tails are required for an optimal association between HIV-1 integrase (IN) and the nucleosome for efficient integration. We also demonstrate direct interactions between IN and the amino-terminal tail of human histone H4 in vitro. Structure/function studies enabled us to identify amino acids in the carboxy-terminal domain of IN that are important for this interaction. Analysis of the nucleosome-binding properties of catalytically active mutated INs confirmed that their ability to engage the nucleosome for integration in vitro was affected. Pseudovirus particles bearing mutations that affect the IN/H4 association also showed impaired replication capacity due to altered integration and re-targeting of their insertion sites toward dynamic regions of the chromatin with lower nucleosome occupancy. Collectively, our data support a functional association between HIV-1 IN and histone tails that promotes anchoring of the intasome to nucleosomes and optimal integration into chromatin.

Finite T spectral function of a single carrier injected into an Ising chain: a comparison of 3 different models

NASA Astrophysics Data System (ADS)

Moeller, Mirko; Berciu, Mona

2015-03-01

When studying the properties of complex, magnetic materials it is often necessary to work with effective Hamiltonians. In many cases the effective Hamiltonian is obtained by mapping the full, multiband Hamiltonian onto a simpler, single band model. A prominent example is the use of Zhang-Rice singlets to map the multiband Emery model for cuprates onto the single band t - J -model. Such mappings are usually done at zero temperature (T) and it is implicitly assumed that they are justified at finite T, as well. We present results on 3 different models of a single charge carrier (electron or hole) injected into a ferromagnetic Ising chain. Model I is a two band, two sublattice model, Model II is a two band, single sublattice model, and Model III is a single band model, the so called t -Jz -model. Due to the absence of spin-flip terms, a numerically exact solution of all 3 Models is possible, even at finite T. At zero T a mapping between all 3 models results in the same low energy physics. However, this is no longer true at finite T. Here the low energy behavior of Model III is significantly different from that of Models I and II. The reasons for this discrepancy and its implications for more realistic models (higher dimension, inclusion of spin-flip terms) are discussed. This work was supported by NSERC, QMI and the UBC 4YF (M.M.).

Tuning the Seebeck effect in C60-based hybrid thermoelectric devices through temperature-dependent surface polarization and thermally-modulated interface dipoles.

PubMed

Liu, Yuchun; Xu, Ling; Zhao, Chen; Shao, Ming; Hu, Bin

2017-06-07

Fullerene (C 60 ) is an important n-type organic semiconductor with high electron mobility and low thermal conductivity. In this work, we report the experimental results on the tunable Seebeck effect of C 60 hybrid thin-film devices by adopting different oxide layers. After inserting n-type high-dielectric constant titanium oxide (TiO x ) and zinc oxide (ZnO) layers, we observed a significantly enhanced n-type Seebeck effect in oxide/C 60 hybrid devices with Seebeck coefficients of -5.8 mV K -1 for TiO x /C 60 and -2.08 mV K -1 for ZnO/C 60 devices at 100 °C, compared with the value of -400 μV K -1 for the pristine C 60 device. However, when a p-type nickel oxide (NiO) layer is inserted, the C 60 hybrid devices show a p-type to n-type Seebeck effect transition when the temperature increases. The remarkable Seebeck effect and change in Seebeck coefficient in different oxide/C 60 hybrid devices can be attributed to two reasons: the temperature-dependent surface polarization difference and thermally-dependent interface dipoles. Firstly, the surface polarization difference due to temperature-dependent electron-phonon coupling can be enhanced by inserting an oxide layer and functions as an additional driving force for the Seebeck effect development. Secondly, thermally-dependent interface dipoles formed at the electrode/oxide interface play an important role in modifying the density of interface states and affecting the charge diffusion in hybrid devices. The surface polarization difference and interface dipoles function in the same direction in hybrid devices with TiO x and ZnO dielectric layers, leading to enhanced n-type Seebeck effect, while the surface polarization difference and interface dipoles generate the opposite impact on electron diffusion in ITO/NiO/C 60 /Al, leading to a p-type to n-type transition in the Seebeck effect. Therefore, inserting different oxide layers could effectively modulate the Seebeck effect of C 60 -based hybrid devices through the surface polarization difference and thermally-dependent interface dipoles, which represents an effective approach to tune the vertical Seebeck effect in organic functional devices.

Thermal control system. [removing waste heat from industrial process spacecraft

NASA Technical Reports Server (NTRS)

Hewitt, D. R. (Inventor)

1983-01-01

The temperature of an exothermic process plant carried aboard an Earth orbiting spacecraft is regulated using a number of curved radiator panels accurately positioned in a circular arrangement to form an open receptacle. A module containing the process is insertable into the receptacle. Heat exchangers having broad exterior surfaces extending axially above the circumference of the module fit within arcuate spacings between adjacent radiator panels. Banks of variable conductance heat pipes partially embedded within and thermally coupled to the radiator panels extend across the spacings and are thermally coupled to broad exterior surfaces of the heat exchangers by flanges. Temperature sensors monitor the temperature of process fluid flowing from the module through the heat exchanges. Thermal conduction between the heat exchangers and the radiator panels is regulated by heating a control fluid within the heat pipes to vary the effective thermal length of the heat pipes in inverse proportion to changes in the temperature of the process fluid.

Characterization of Ether-à-go-go Channels Present in Photoreceptors Reveals Similarity to IKx, a K+ Current in Rod Inner Segments

PubMed Central

Frings, Stephan; Brüll, Nicole; Dzeja, Claudia; Angele, Albert; Hagen, Volker; Kaupp, U. Benjamin; Baumann, Arnd

1998-01-01

In this study, we describe two splice variants of an ether-à-go-go (EAG) K+ channel cloned from bovine retina: bEAG1 and bEAG2. The bEAG2 polypeptide contains an additional insertion of 27 amino acids in the extracellular linker between transmembrane segments S3 and S4. The heterologously expressed splice variants differ in their activation kinetics and are differently modulated by extracellular Mg2+. Cooperativity of modulation by Mg2+ suggests that each subunit of the putative tetrameric channel binds a Mg2+ ion. The channels are neither permeable to Ca2+ ions nor modulated by cyclic nucleotides. In situ hybridization localizes channel transcripts to photoreceptors and retinal ganglion cells. Comparison of EAG currents with IKx, a noninactivating K+ current in the inner segment of rod photoreceptors, reveals an intriguing similarity, suggesting that EAG polypeptides are involved in the formation of Kx channels. PMID:9524140

Demonstration of Compact and Low-Loss Athermal Arrayed-Waveguide Grating Module Based on 2.5%-Δ Silica-Based Waveguides

NASA Astrophysics Data System (ADS)

Maru, Koichi; Abe, Yukio; Uetsuka, Hisato

2008-10-01

We demonstrated a compact and low-loss athermal arrayed-waveguide grating (AWG) module utilizing silica-based planar lightwave circuit (PLC) technology. Spot-size converters based on a vertical ridge-waveguide taper were integrated with a 2.5%-Δ athermal AWG to reduce the loss at chip-to-fiber interface. Spot-size converters based on a segmented core were formed around resin-filled trenches for athermalization formed in the slab to reduce the diffraction loss at the trenches. A 16-channel athermal AWG module with 100-GHz channel spacing was fabricated. The use of a 2.5%-Δ athermal chip with a single-side fiber array enabled a compact package of the size of 41.6×16.6×4.5 mm3. Athermal characteristics and a small insertion loss of 3.5-3.8 dB were obtained by virtue of low fiber-to-chip coupling loss and athermalization with low excess loss.

Electrical capacitance clearanceometer

NASA Technical Reports Server (NTRS)

Hester, Norbert J. (Inventor); Hornbeck, Charles E. (Inventor); Young, Joseph C. (Inventor)

1992-01-01

A hot gas turbine engine capacitive probe clearanceometer is employed to measure the clearance gap or distance between blade tips on a rotor wheel and its confining casing under operating conditions. A braze sealed tip of the probe carries a capacitor electrode which is electrically connected to an electrical inductor within the probe which is inserted into a turbine casing to position its electrode at the inner surface of the casing. Electrical power is supplied through a voltage controlled variable frequency oscillator having a tuned circuit in which the probe is a component. The oscillator signal is modulated by a change in electrical capacitance between the probe electrode and a passing blade tip surface while an automatic feedback correction circuit corrects oscillator signal drift. A change in distance between a blade tip and the probe electrode is a change in capacitance therebetween which frequency modulates the oscillator signal. The modulated oscillator signal which is then processed through a phase detector and related circuitry to provide an electrical signal is proportional to the clearance gap.

Strain modulation-enhanced Mg acceptor activation efficiency of Al0.14Ga0.86N/GaN superlattices with AlN interlayer

NASA Astrophysics Data System (ADS)

Wang, Lei; Li, Rui; Li, Ding; Liu, Ningyang; Liu, Lei; Chen, Weihua; Wang, Cunda; Yang, Zhijian; Hu, Xiaodong

2010-02-01

AlN layer was grown as interlayer between undoped GaN and Mg doped Al0.14Ga0.86N/GaN superlattices (SLs) epilayer to modulate the strain distribution between Al0.14Ga0.86N barrier and GaN well layers in SLs sample. Strain relaxation was observed in the SLs sample with AlN interlayer by x-ray diffraction reciprocal space mapping method. The measured hole concentration of SLs sample with AlN interlayer at room temperature was over 1.6×1018 cm-3 but that was only 6.6×1016 cm-3 obtained in SLs sample without AlN interlayer. Variable temperature Hall-effect measurement showed that the acceptor activation energy decreased from 150 to 70 meV after inserting the AlN layer, which indicated that the strain modulation of SLs induced by AlN interlayer was beneficial to the Mg acceptor activation and hole concentration enhancement.

Development of parametric material, energy, and emission inventories for wafer fabrication in the semiconductor industry.

PubMed

Murphy, Cynthia F; Kenig, George A; Allen, David T; Laurent, Jean-Philippe; Dyer, David E

2003-12-01

Currently available data suggest that most of the energy and material consumption related to the production of an integrated circuit is due to the wafer fabrication process. The complexity of wafer manufacturing, requiring hundreds of steps that vary from product to product and from facility to facility and which change every few years, has discouraged the development of material, energy, and emission inventory modules for the purpose of insertion into life cycle assessments. To address this difficulty, a flexible, process-based system for estimating material requirements, energy requirements, and emissions in wafer fabrication has been developed. The method accounts for mass and energy use atthe unit operation level. Parametric unit operation modules have been developed that can be used to predict changes in inventory as the result of changes in product design, equipment selection, or process flow. A case study of the application of the modules is given for energy consumption, but a similar methodology can be used for materials, individually or aggregated.

The enhancement of the Transtage for the commercial Titan launch vehicle

NASA Astrophysics Data System (ADS)

Gunter, D.; Gizinski, S.

1987-06-01

The configuration of the Transtage upper stage and its application to the Titan III launch vehicle are examined. The Transtage consists of a control and a propulsion module, and is about 10 feet in diameter and 14.75 feet in length. The elements of the control and propulsion modules and their functions are described. The Transtage/Titan III combination allows for the insertion of a payload into geostationary transfer orbit and eliminates the requirement for a perigee kick motor system. It is observed that the addition of the Transtage upper stage to the Titan III launch vehicle provides a geosynchronous transfer orbit capability of 9500 lbs, flexible mission tailoring, and reliability exceeding 96 percent. Diagrams of the Titan III and the Transtage and its components are provided.

Scalability analysis methodology for passive optical interconnects in data center networks using PAM

NASA Astrophysics Data System (ADS)

Lin, R.; Szczerba, Krzysztof; Agrell, Erik; Wosinska, Lena; Tang, M.; Liu, D.; Chen, J.

2017-11-01

A framework is developed for modeling the fundamental impairments in optical datacenter interconnects, i.e., the power loss and the receiver noises. This framework makes it possible, to analyze the trade-offs between data rates, modulation order, and number of ports that can be supported in optical interconnect architectures, while guaranteeing that the required signal-to-noise ratios are satisfied. To the best of our knowledge, this important assessment methodology is not yet available. As a case study, the trade-offs are investigated for three coupler-based top-of-rack interconnect architectures, which suffer from serious insertion loss. The results show that using single-port transceivers with 10 GHz bandwidth, avalanche photodiode detectors, and quadratical pulse amplitude modulation, more than 500 ports can be supported.

Apollo 17 prime crew portrait

NASA Image and Video Library

1971-09-30

S72-50438 (September 1972) --- These three astronauts are the prime crew members of the Apollo 17 lunar landing mission. They are Eugene A. Cernan (seated), commander; Ronald E. Evans (standing on right), command module pilot; and Harrison H. Schmitt, lunar module pilot. They are photographed with a Lunar Roving Vehicle (LRV) trainer. Cernan and Schmitt will use an LRV during their exploration of the Taurus-Littrow landing site. The Apollo 17 Saturn V space vehicle is in the background. This picture was taken at Pad A, Launch Complex 39, Kennedy Space Center (KSC), Florida. The Apollo 17 insignia is in the photo insert at upper left. The insignia, designed by artist Robert T. McCall in collaboration with the crewmen, is dominated by the image of Apollo, the Greek sun god.

Apollo-Lunar Orbital Rendezvous Technique

NASA Technical Reports Server (NTRS)

1963-01-01

The film shows artists rendition of the spacecrafts, boosters, and flight of the Apollo lunar missions. The Apollo spacecraft will consist of three modules: the manned Command Module; the Service Module, which contains propulsion systems; and the Lunar Excursion Module (LEM) to carry astronauts to the moon and back to the Command and Service Modules. The spacecraft will be launched via a three-stage Saturn booster. The first stage will provide 7.5 million pounds of thrust from five F-1 engines for liftoff and initial powered flight. The second stage will develop 1 million pounds of thrust from five J-2 engines to boost the spacecraft almost into Earth orbit. Immediately after ignition of the second stage, the Launch Escape System will be jettisoned. A single J-2 engine in the S4B stage will provide 200,000 pounds of thrust to place the spacecraft in an earth parking orbit. It also will be used to propel the spacecraft into a translunar trajectory, then it will separate from the Apollo Modules. Onboard propulsion systems will be used to insert the spacecraft into lunar orbit. Two astronauts will enter the LEM, which will separate from the command and service modules. The LEM will go into elliptical orbit and prepare for landing. The LEM will lift off of the Moon's surface to return to the Command and Service Modules, and most likely be left in lunar orbit. After leaving the Moon's orbit, and shortly before entering Earth's orbit, the Service Module will be ejected. The Command Module will be oriented for reentry into the Earth's atmosphere. A drogue parachute will deploy at approximately 50,000 feet, followed by the main parachute system for touchdown.

Modulation of innate immune responses by Yersinia type III secretion system translocators and effectors.

PubMed

Bliska, James B; Wang, Xiaoying; Viboud, Gloria I; Brodsky, Igor E

2013-10-01

The innate immune system of mammals responds to microbial infection through detection of conserved molecular determinants called 'pathogen-associated molecular patterns' (PAMPs). Pathogens use virulence factors to counteract PAMP-directed responses. The innate immune system can in turn recognize signals generated by virulence factors, allowing for a heightened response to dangerous pathogens. Many Gram-negative bacterial pathogens encode type III secretion systems (T3SSs) that translocate effector proteins, subvert PAMP-directed responses and are critical for infection. A plasmid-encoded T3SS in the human-pathogenic Yersinia species translocates seven effectors into infected host cells. Delivery of effectors by the T3SS requires plasma membrane insertion of two translocators, which are thought to form a channel called a translocon. Studies of the Yersinia T3SS have provided key advances in our understanding of how innate immune responses are generated by perturbations in plasma membrane and other signals that result from translocon insertion. Additionally, studies in this system revealed that effectors function to inhibit innateimmune responses resulting from insertion of translocons into plasma membrane. Here, we review these advances with the goal of providing insight into how a T3SS can activate and inhibit innate immune responses, allowing a virulent pathogen to bypass host defences. © 2013 John Wiley & Sons Ltd.

Cytocompatibility testing of cell culture modules fabricated from specific candidate biomaterials using injection molding.

PubMed

Hiebl, Bernhard; Lützow, Karola; Lange, Maik; Jung, Friedrich; Seifert, Barbara; Klein, Frank; Weigel, Thomas; Kratz, Karl; Lendlein, Andreas

2010-07-01

Most polymers used in clinical applications today are materials that have been developed originally for application areas other than biomedicine. Testing the cell- and tissue-compatibility of novel materials in vitro and in vivo is of key importance for the approval of medical devices and is regulated according to the Council Directive 93/42/EEC of the European communities concerning medical devices. In the standardized testing methods the testing sample is placed in commercially available cell culture plates, which are often made from polystyrene. Thus not only the testing sample itself influences cell behavior but also the culture vessel material. In order to exclude this influence, a new system for cell testing will be presented allowing a more precise and systematic investigation by preparing tailored inserts which are made of the testing material. Inserts prepared from polystyrene, polycarbonate and poly(ether imide) were tested for their cytotoxity and cell adherence. Furthermore a proof of principle concerning the preparation of inserts with a membrane-like surface structure and its surface modification was established. Physicochemical investigations revealed a similar morphology and showed to be very similar to the findings to analogous preparations and modifications of flat-sheet membranes. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Development of a smart IUD launcher for prevention of uterine perforation.

PubMed

Al-Ashwal, Rania Hussein; Aziz, Noor Afatin Che; Nooh, Syed Mohd

2016-10-01

Intrauterine contraception is a widely used, highly effective and reversible means of birth control. One potential disadvantage with the use of intrauterine devices (IUDs) is the risk of uterine perforation. During the process of IUD insertion, there is a possibility to perforate the wall of the uterus during which health workers might injure the fundus of the uterus, due to inadequate knowledge or insufficient training. This paper discusses the development of a smart IUD launcher insertion system that would be used to prevent perforation of the uterine wall by detecting a specific distance to the wall for the safe release of the IUD using a sensor. Several launcher prototypes were developed prior to the final version of the IUD launcher. The results from testing experiments, that have been conducted to evaluate the performance of the proposed device, show that the sensor is able to detect a distance up to 5 mm and is also capable of detecting the distance to the target even in high viscosity liquid. The developed prototype promises a solution for more accurate IUD insertion that could be used as a training module for health care providers, helping remove fear from using this long-lasting contraceptive method and promote an affordable modern contraceptive method to society.

The Design of an Experimental Apparatus to Measure the Motions of a Towed Submersible Environmental Sensor Vehicle.

DTIC Science & Technology

1983-06-01

obtained by the vertical excitation apparatus, keeping the horizontal excitation apparatus .4 at zero frequ ncy. The model c.g. moves in a sinusoidal...point between the support plates and the rail module, foam rubber pads were inserted.. These pads increased the coefficient of friction and reduced the...involved the CADIG 4051 Tektronix computer data SI acquistion and graphic display system. The Tektronix 4050 series computers can be used as stand alone

Fissile material detector

DOEpatents

Ivanov, Alexander I.; Lushchikov, Vladislav I.; Shabalin, Eugeny P.; Maznyy, Nikita G.; Khvastunov, Michael M.; Rowland, Mark

2002-01-01

A detector for fissile materials which provides for integrity monitoring of fissile materials and can be used for nondestructive assay to confirm the presence of a stable content of fissile material in items. The detector has a sample cavity large enough to enable assay of large items of arbitrary configuration, utilizes neutron sources fabricated in spatially extended shapes mounted on the endcaps of the sample cavity, incorporates a thermal neutron filter insert with reflector properties, and the electronics module includes a neutron multiplicity coincidence counter.

Vibrio cholerae InV117, a Class 1 Integron Harboring aac(6′)-Ib and blaCTX-M-2, Is Linked to Transposition Genes

PubMed Central

Soler Bistué, Alfonso J. C.; Martín, Fernando A.; Petroni, Alejandro; Faccone, Diego; Galas, Marcelo; Tolmasky, Marcelo E.; Zorreguieta, Angeles

2006-01-01

A ca. 150-kbp Vibrio cholerae O1 biotype El Tor plasmid includes blaCTX-M-2 and a variant of aac(6′)-Ib within InV117, an orf513-bearing class 1 integron. InV117 is linked to a tnp1696 module in which IRl carries an insertion of IS4321R. The complete structure could be a potential mobile element. PMID:16641475

Mobile Manipulation and Mobility as Manipulation: Design and Algorithms of RoboSimian

DTIC Science & Technology

2014-05-01

feature was left out for the competition hands. The hand has three under-actuated fingers, each with a braided Dyneema R© tendon wrapped around pulleys at...models of objects (e.g. valves, ladders, hoses , etc.) into the world manually so that RoboSimian could interact with objects for manipulation. The remote...with a single button press (e.g. “rotate-valve”, “insert- hose ”, “push-open-door”), depending on the task. Note that since the plan module was run on

On-chip tunable dispersion in a ring laser gyroscope for enhanced rotation sensing

NASA Astrophysics Data System (ADS)

Zhang, Hao; Liu, Jiaming; Lin, Jian; Li, Wenxiu; Xue, Xia; Huang, Anping; Xiao, Zhisong

2016-05-01

A gyroscope structure with tailored local dispersion profile to enhance sensitivity is proposed, which uses lithium niobate (LiNbO3) thin film as the on-chip material of gyroscope's resonator. A Mach-Zehnder interferometer (MZI) structure as a coupler, which induces a different reference phase shift in each arm, is inserted into the position between ring resonator and output bus waveguide. Through modulating reference phase shift in MZI, theoretical rotation sensitivity enhancement as large as one order of magnitude is presented.

Automated 3D bioassembly of micro-tissues for biofabrication of hybrid tissue engineered constructs.

PubMed

Mekhileri, N V; Lim, K S; Brown, G C J; Mutreja, I; Schon, B S; Hooper, G J; Woodfield, T B F

2018-01-12

Bottom-up biofabrication approaches combining micro-tissue fabrication techniques with extrusion-based 3D printing of thermoplastic polymer scaffolds are emerging strategies in tissue engineering. These biofabrication strategies support native self-assembly mechanisms observed in developmental stages of tissue or organoid growth as well as promoting cell-cell interactions and cell differentiation capacity. Few technologies have been developed to automate the precise assembly of micro-tissues or tissue modules into structural scaffolds. We describe an automated 3D bioassembly platform capable of fabricating simple hybrid constructs via a two-step bottom-up bioassembly strategy, as well as complex hybrid hierarchical constructs via a multistep bottom-up bioassembly strategy. The bioassembly system consisted of a fluidic-based singularisation and injection module incorporated into a commercial 3D bioprinter. The singularisation module delivers individual micro-tissues to an injection module, for insertion into precise locations within a 3D plotted scaffold. To demonstrate applicability for cartilage tissue engineering, human chondrocytes were isolated and micro-tissues of 1 mm diameter were generated utilising a high throughput 96-well plate format. Micro-tissues were singularised with an efficiency of 96.0 ± 5.1%. There was no significant difference in size, shape or viability of micro-tissues before and after automated singularisation and injection. A layer-by-layer approach or aforementioned bottom-up bioassembly strategy was employed to fabricate a bilayered construct by alternatively 3D plotting a thermoplastic (PEGT/PBT) polymer scaffold and inserting pre-differentiated chondrogenic micro-tissues or cell-laden gelatin-based (GelMA) hydrogel micro-spheres, both formed via high-throughput fabrication techniques. No significant difference in viability between the construct assembled utilising the automated bioassembly system and manually assembled construct was observed. Bioassembly of pre-differentiated micro-tissues as well as chondrocyte-laden hydrogel micro-spheres demonstrated the flexibility of the platform while supporting tissue fusion, long-term cell viability, and deposition of cartilage-specific extracellular matrix proteins. This technology provides an automated and scalable pathway for bioassembly of both simple and complex 3D tissue constructs of clinically relevant shape and size, with demonstrated capability to facilitate direct spatial organisation and hierarchical 3D assembly of micro-tissue modules, ranging from biomaterial free cell pellets to cell-laden hydrogel formulations.

Simulation improves procedural protocol adherence during central venous catheter placement: a randomized-controlled trial

PubMed Central

Peltan, Ithan D.; Shiga, Takashi; Gordon, James A.; Currier, Paul F.

2015-01-01

Background Simulation training may improve proficiency at and reduces complications from central venous catheter (CVC) placement, but the scope of simulation’s effect remains unclear. This randomized controlled trial evaluated the effects of a pragmatic CVC simulation program on procedural protocol adherence, technical skill, and patient outcomes. Methods Internal medicine interns were randomized to standard training for CVC insertion or standard training plus simulation-based mastery training. Standard training involved a lecture, a video-based online module, and instruction by the supervising physician during actual CVC insertions. Intervention-group subjects additionally underwent supervised training on a venous access simulator until they demonstrated procedural competence. Raters evaluated interns’ performance during internal jugular CVC placement on actual patients in the medical intensive care unit. Generalized estimating equations were used to account for outcome clustering within trainees. Results We observed 52 interns place 87 CVCs. Simulation-trained interns exhibited better adherence to prescribed procedural technique than interns who received only standard training (p=0.024). There were no significant differences detected in first-attempt or overall cannulation success rates, mean needle passes, global assessment scores or complication rates. Conclusions Simulation training added to standard training improved protocol adherence during CVC insertion by novice practitioners. This study may have been too small to detect meaningful differences in venous cannulation proficiency and other clinical outcomes, highlighting the difficulty of patient-centered simulation research in settings where poor outcomes are rare. For high-performing systems, where protocol deviations may provide an important proxy for rare procedural complications, simulation may improve CVC insertion quality and safety. PMID:26154250

Tail-anchored Protein Insertion in Mammals

PubMed Central

Cardani, Silvia; Maroli, Annalisa; Vitiello, Adriana; Soffientini, Paolo; Crespi, Arianna; Bram, Richard F.

2016-01-01

The GET (guided entry of tail-anchored proteins)/TRC (transmembrane recognition complex) pathway for tail-anchored protein targeting to the endoplasmic reticulum (ER) has been characterized in detail in yeast and is thought to function similarly in mammals, where the orthologue of the central ATPase, Get3, is known as TRC40 or Asna1. Get3/TRC40 function requires an ER receptor, which in yeast consists of the Get1/Get2 heterotetramer and in mammals of the WRB protein (tryptophan-rich basic protein), homologous to yeast Get1, in combination with CAML (calcium-modulating cyclophilin ligand), which is not homologous to Get2. To better characterize the mammalian receptor, we investigated the role of endogenous WRB and CAML in tail-anchored protein insertion as well as their association, concentration, and stoichiometry in rat liver microsomes and cultured cells. Functional proteoliposomes, reconstituted from a microsomal detergent extract, lost their activity when made with an extract depleted of TRC40-associated proteins or of CAML itself, whereas in vitro synthesized CAML and WRB together were sufficient to confer insertion competence to liposomes. CAML was found to be in ∼5-fold excess over WRB, and alteration of this ratio did not inhibit insertion. Depletion of each subunit affected the levels of the other one; in the case of CAML silencing, this effect was attributable to destabilization of the WRB transcript and not of WRB protein itself. These results reveal unanticipated complexity in the mutual regulation of the TRC40 receptor subunits and raise the question as to the role of the excess CAML in the mammalian ER. PMID:27226539

Design of multi-mission chemical propulsion modules for planetary orbiters. Volume 1: Summary report

NASA Technical Reports Server (NTRS)

1975-01-01

Results are presented of a conceptual design and feasibility study of chemical propulsion stages that can serve as modular propulsion units, with little or no modification, on a variety of planetary orbit missions, including orbiters of Mercury, Saturn, and Uranus. Planetary spacecraft of existing design or currently under development, viz., spacecraft of the Pioneer and Mariner families, are assumed as payload vehicles. Thus, operating requirements of spin-stabilized and 3-axis stabilized spacecraft have to be met by the respective propulsion module designs. As launch vehicle for these missions the Shuttle orbiter and interplanetary injection stage, or Tug, plus solid-propellant kick motor was assumed. Accommodation constraints and interfaces involving the payloads and the launch vehicle are considered in the propulsion module design. The applicability and performance advantages were evaluated of the space-storable high-energy bipropellants. The incentive for using this advanced propulsion technology on planetary missions is the much greater performance potential when orbit insertion velocities in excess of 4 km/sec are required, as in the Mercury orbiter. Design analyses and performance tradeoffs regarding earth-storable versus space-storable propulsion systems are included. Cost and development schedules of multi-mission versus custom-designed propulsion modules are examined.

Scatter correction using a primary modulator on a clinical angiography C-arm CT system.

PubMed

Bier, Bastian; Berger, Martin; Maier, Andreas; Kachelrieß, Marc; Ritschl, Ludwig; Müller, Kerstin; Choi, Jang-Hwan; Fahrig, Rebecca

2017-09-01

Cone beam computed tomography (CBCT) suffers from a large amount of scatter, resulting in severe scatter artifacts in the reconstructions. Recently, a new scatter correction approach, called improved primary modulator scatter estimation (iPMSE), was introduced. That approach utilizes a primary modulator that is inserted between the X-ray source and the object. This modulation enables estimation of the scatter in the projection domain by optimizing an objective function with respect to the scatter estimate. Up to now the approach has not been implemented on a clinical angiography C-arm CT system. In our work, the iPMSE method is transferred to a clinical C-arm CBCT. Additional processing steps are added in order to compensate for the C-arm scanner motion and the automatic X-ray tube current modulation. These challenges were overcome by establishing a reference modulator database and a block-matching algorithm. Experiments with phantom and experimental in vivo data were performed to evaluate the method. We show that scatter correction using primary modulation is possible on a clinical C-arm CBCT. Scatter artifacts in the reconstructions are reduced with the newly extended method. Compared to a scan with a narrow collimation, our approach showed superior results with an improvement of the contrast and the contrast-to-noise ratio for the phantom experiments. In vivo data are evaluated by comparing the results with a scan with a narrow collimation and with a constant scatter correction approach. Scatter correction using primary modulation is possible on a clinical CBCT by compensating for the scanner motion and the tube current modulation. Scatter artifacts could be reduced in the reconstructions of phantom scans and in experimental in vivo data. © 2017 American Association of Physicists in Medicine.

Allelic imbalance modulates surface expression of the tolerance-inducing HLA-G molecule on primary trophoblast cells.

PubMed

Djurisic, S; Teiblum, S; Tolstrup, C K; Christiansen, O B; Hviid, T V F

2015-03-01

The HLA-G molecule is expressed on trophoblast cells at the feto-maternal interface, where it interacts with local immune cells, and upholds tolerance against the semi-allogeneic fetus. Aberrant HLA-G expression in the placenta and reduced soluble HLA-G levels are observed in pregnancy complications, partly explained by HLA-G polymorphisms which are associated with differences in the alternative splicing pattern and of the stability of HLA-G mRNA. Of special importance is a 14 bp insertion/deletion polymorphism located in the 3'-untranslated region of the HLA-G gene. In the current study, we present novel evidence for allelic imbalance of the 14 bp insertion/deletion polymorphism, using a very accurate and sensitive Digital droplet PCR technique. Allelic imbalance in heterozygous samples was observed as differential expression levels of 14 bp insertion/deletion allele-specific mRNA transcripts, which was further associated with low levels of HLA-G surface expression on primary trophoblast cells. Full gene sequencing of HLA-G allowed us to study correlations between HLA-G extended haplotypes and single-nucleotide polymorphisms and HLA-G surface expression. We found that a 1:1 expression (allelic balance) of the 14 bp insertion/deletion mRNA alleles was associated with high surface expression of HLA-G and with a specific HLA-G extended haplotype. The 14 bp del/del genotype was associated with a significantly lower abundance of the G1 mRNA isoform, and a higher abundance of the G3 mRNA isoform. Overall, the present study provides original evidence for allelic imbalance of the 14 bp insertion/deletion polymorphism, which influences HLA-G surface expression on primary trophoblast cells, considered to be important in the pathogenesis of pre-eclampsia and other pregnancy complications. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Immediate versus delayed insertion of an etonogestrel releasing implant at medical abortion-a randomized controlled equivalence trial.

PubMed

Hognert, Helena; Kopp Kallner, Helena; Cameron, Sharon; Nyrelli, Christina; Jawad, Izabella; Heller, Rebecca; Aronsson, Annette; Lindh, Ingela; Benson, Lina; Gemzell-Danielsson, Kristina

2016-11-01

Does a progestin releasing subdermal contraceptive implant affect the efficacy of medical abortion if inserted at the same visit as the progesterone receptor modulator, mifepristone, at medical abortion? A etonogestrel releasing subdermal implant inserted on the day of mifepristone did not impair the efficacy of the medical abortion compared with routine insertion at 2-4 weeks after the abortion. The etonogestrel releasing subdermal implant is one of the most effective long acting reversible contraceptive methods. The effect of timing of placement on the efficacy of mifepristone and impact on prevention of subsequent unintended pregnancy is not known. This multicentre, randomized controlled, equivalence trial with recruitment between 13 October 2013 and 17 October 2015 included a total of 551 women with pregnancies below 64 days gestation opting for the etonogestrel releasing subdermal implant as postabortion contraception. Women were randomized to either insertion at 1 hour after mifepristone intake (immediate) or at follow-up 2-4 weeks later (delayed insertion). An equivalence design was used due to advantages for women such as fewer visits to the clinic with immediate insertion. The primary outcome was the percentage of women with complete abortion not requiring surgical intervention within 1 month. Secondary outcomes included insertion rates, pregnancy and repeat abortion rates during 6 months follow-up. Analysis was per protocol and by intention to treat. Women aged 18 years and older who had requested medical termination of a pregnancy up to 63 days of gestation and opted for an etonogestrel releasing contraceptive implant were recruited in outpatient family planning clinics in six hospitals in Sweden and Scotland. Efficacy of medical abortion was 259/275 (94.2%) in the immediate insertion group and 239/249 (96%) in the routine insertion group with a risk difference of 1.8% (95% CI -0.4 to 4.1%), which was within the ±5% margin of equivalence. The insertion rate was 275/277 (98.9%) in the immediate group compared to 187/261 (71.6%) women in the routine group (P < 0.001). At 6 months of follow-up significantly fewer women in the immediate group had become pregnant again (2/277, 0.8%) compared to the routine group (10/261, 3.8%) P = 0.018. For the main outcome loss to follow-up data was minimized through access to patient records. Efforts were made to reduce loss to follow-up also for secondary outcomes. The results of the sensitivity analysis did not differ from the intention to treat or per protocol analysis. Guidelines on postabortion contraception should be amended to include insertion of the etonogestrel releasing implant at the time of mifepristone intake for medical abortion up to and including a gestation of 63 days. This study was funded by the Swedish Research Council (2012-2844), Stockholm City County and Karolinska Institutet (ALF). The contraceptive implants were provided by Merck and supplied by MSD Sweden. HKK and KGD have received honorariums for giving lectures for MSD/Merck and have participated in the national (HKK and KGD) and international (KGD) medical advisory boards for MSD/Merck. The other authors have nothing to declare. ClinicalTrials number NCT01920022. 06 August 2013. 13 October 2013. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The DEAD-box helicase eIF4A: paradigm or the odd one out?

PubMed

Andreou, Alexandra Z; Klostermeier, Dagmar

2013-01-01

DEAD-box helicases catalyze the ATP-dependent unwinding of RNA duplexes. They share a helicase core formed by two RecA-like domains that carries a set of conserved motifs contributing to ATP binding and hydrolysis, RNA binding and duplex unwinding. The translation initiation factor eIF4A is the founding member of the DEAD-box protein family, and one of the few examples of DEAD-box proteins that consist of a helicase core only. It is an RNA-stimulated ATPase and a non-processive helicase that unwinds short RNA duplexes. In the catalytic cycle, a series of conformational changes couples the nucleotide cycle to RNA unwinding. eIF4A has been considered a paradigm for DEAD-box proteins, and studies of its function have revealed the governing principles underlying the DEAD-box helicase mechanism. However, as an isolated helicase core, eIF4A is rather the exception, not the rule. Most helicase modules in other DEAD-box proteins are modified, some by insertions into the RecA-like domains, and the majority by N- and C-terminal appendages. While the basic catalytic function resides within the helicase core, its modulation by insertions, additional domains or a network of interaction partners generates the diversity of DEAD-box protein functions in the cell. This review summarizes the current knowledge on eIF4A and its regulation, and discusses to what extent eIF4A serves as a model DEAD-box protein.

The integrase of the long terminal repeat-retrotransposon tf1 has a chromodomain that modulates integrase activities.

PubMed

Hizi, Amnon; Levin, Henry L

2005-11-25

Chromodomains in a variety of proteins mediate the formation of heterochromatin by interacting directly with histone H3, DNA, or RNA. A diverse family of long terminal repeat (LTR)-retrotransposons possesses chromodomains in their integrases (IN), suggesting that the chromodomains may control integration. The LTR-retrotransposon Tf1 of Schizosaccharomyces pombe is highly active and possesses a chromodomain in the COOH terminus of its IN. To test this chromodomain for a role in integration, recombinant INs with and without the chromodomain were assayed for activity in in vitro reactions. The full-length IN had integration activity with oligonucleotide substrates that modeled both the insertion reaction and a reverse reaction known as disintegration. The INs of retroviruses possess an additional activity termed 3' processing that must remove 2-3 nucleotides from the 3' ends of the viral cDNA before insertion can occur. These additional nucleotides are added during reverse transcription because of the position of the minus strand primer downstream of the LTR. The position of the primer for Tf1 suggests no nucleotides are added 3' of the LTR. It was therefore surprising that Tf1 IN was capable of 3' cleavage. The most unexpected result reported here was that the IN lacking the chromodomain had significantly higher activity and substantially reduced substrate specificity. These results reveal that both the activity and specificity of enzymes can be modulated by their chromodomains.

Band edge engineering of oxide photoanodes for photoelectrochemical water splitting: Integration of subsurface dipoles with atomic-scale control

DOE PAGES

Hikita, Yasuyuki; Nishio, Kazunori; Seitz, Linsey C.; ...

2016-01-22

One of the crucial parameters dictating the efficiency of photoelectrochemical water-splitting is the semiconductor band edge alignment with respect to hydrogen and oxygen redox potentials. Despite the importance of metal oxides in their use as photoelectrodes, studies to control the band edge alignment in aqueous solution have been limited predominantly to compound semiconductors with modulation ranges limited to a few hundred mV. The ability to modulate the flat band potential of oxide photoanodes by as much as 1.3 V, using the insertion of subsurface electrostatic dipoles near a Nb-doped SrTiO 3/aqueous electrolyte interface is reported. Lastly, the tunable range achievedmore » far exceeds previous reports in any semiconductor/aqueous electrolyte system and suggests a general design strategy for highly efficient oxide photoelectrodes.« less

Hybrid Integration of III-V Solar Microcells for High Efficiency Concentrated Photovoltaic Modules

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

Tauke-Pedretti, Anna; Cederberg, Jeffery; Cruz-Campa, Jose Luis

The design, fabrication and performance of InGaAs and InGaP/GaAs microcells are presented. These cells are integrated with a Si wafer providing a path for insertion in hybrid concentrated photovoltaic modules. Comparisons are made between bonded cells and cells fabricated on their native wafer. The bonded cells showed no evidence of degradation in spite of the integration process which involved significant processing including the removal of the III-V substrate. Results from a number of hybrid cell configurations were reported. These cells employed integration techniques including wafer level bonding of processed cells and solder bonding of the cells. Lastly, the cells themselvesmore » showed evidence of degradation in spite of the integration process, which involved significant processing including the removal of the III-V substrate.« less

Effects of annealing on performances of 1.3-μm InAs-InGaAs-GaAs quantum dot electroabsorption modulators

PubMed Central

2013-01-01

In this work, we investigated the effects of quantum dot (QD) annealing (as-grown, 600°C-annealed, and 750°C-annealed) on the preliminary performances of 1.3-μm InAs-InGaAs-GaAs quantum dot electroabsorption modulators (QD-EAMs). Both extinction ratio and insertion loss were found to vary inversely with the annealing temperature. Most importantly, the 3-dB response of the 750°C-annealed lumped-element QD-EAM was found to be 1.6 GHz at zero reverse bias voltage - the lowest reverse bias voltage reported. We believe that this work will be beneficial to researchers working on on-chip integration of QD-EAMs with other devices since energy consumption will be an important consideration. PMID:23388169

Hybrid Integration of III-V Solar Microcells for High Efficiency Concentrated Photovoltaic Modules

DOE PAGES

Tauke-Pedretti, Anna; Cederberg, Jeffery; Cruz-Campa, Jose Luis; ...

2018-03-09

The design, fabrication and performance of InGaAs and InGaP/GaAs microcells are presented. These cells are integrated with a Si wafer providing a path for insertion in hybrid concentrated photovoltaic modules. Comparisons are made between bonded cells and cells fabricated on their native wafer. The bonded cells showed no evidence of degradation in spite of the integration process which involved significant processing including the removal of the III-V substrate. Results from a number of hybrid cell configurations were reported. These cells employed integration techniques including wafer level bonding of processed cells and solder bonding of the cells. Lastly, the cells themselvesmore » showed evidence of degradation in spite of the integration process, which involved significant processing including the removal of the III-V substrate.« less

Genome Editing-Enabled HTS Assays Expand Drug Target Pathways for Charcot–Marie–Tooth Disease

PubMed Central

2015-01-01

Copy number variation resulting in excess PMP22 protein causes the peripheral neuropathy Charcot–Marie–Tooth disease, type 1A. To broadly interrogate chemically sensitive transcriptional pathways controlling PMP22 protein levels, we used the targeting precision of TALEN-mediated genome editing to embed reporters within the genetic locus harboring the Peripheral Myelin Protein 22 (Pmp22) gene. Using a Schwann cell line with constitutively high endogenous levels of Pmp22, we obtained allelic insertion of secreted bioluminescent reporters with sufficient signal to enable a 1536-well assay. Our findings from the quantitative high-throughput screening (qHTS) of several thousand drugs and clinically investigated compounds using this assay design both overlapped and expanded results from a previous assay using a randomly inserted reporter gene controlled by a single regulatory element of the Pmp22 gene. A key difference was the identification of a kinase-controlled inhibitory pathway of Pmp22 transcription revealed by the activity of the Protein kinase C (PKC)-modulator bryostatin. PMID:25188731

Insertion of scFv into the hinge domain of full-length IgG1 monoclonal antibody results in tetravalent bispecific molecule with robust properties.

PubMed

Bezabeh, Binyam; Fleming, Ryan; Fazenbaker, Christine; Zhong, Haihong; Coffman, Karen; Yu, Xiang-Qing; Leow, Ching Ching; Gibson, Nerea; Wilson, Susan; Stover, C Kendall; Wu, Herren; Gao, Changshou; Dimasi, Nazzareno

By simultaneous binding two disease mediators, bispecific antibodies offer the opportunity to broaden the utility of antibody-based therapies. Herein, we describe the design and characterization of Bs4Ab, an innovative and generic bispecific tetravalent antibody platform. The Bs4Ab format comprises a full-length IgG1 monoclonal antibody with a scFv inserted into the hinge domain. The Bs4Ab design demonstrates robust manufacturability as evidenced by MEDI3902, which is currently in clinical development. To further demonstrate the applicability of the Bs4Ab technology, we describe the molecular engineering, biochemical, biophysical, and in vivo characterization of a bispecific tetravalent Bs4Ab that, by simultaneously binding vascular endothelial growth factor and angiopoietin-2, inhibits their function. We also demonstrate that the Bs4Ab platform allows Fc-engineering similar to that achieved with IgG1 antibodies, such as mutations to extend half-life or modulate effector functions.

Multi-operational tuneable Q-switched mode-locking Er fibre laser

NASA Astrophysics Data System (ADS)

Qamar, F. Z.

2018-01-01

A wavelength-spacing tuneable, Q-switched mode-locking (QML) erbium-doped fibre laser based on non-linear polarization rotation controlled by four waveplates and a cube polarizer is proposed. A mode-locked pulse train using two quarter-wave plates and a half-wave plate (HWP) is obtained first, and then an extra HWP is inserted into the cavity to produce different operation regimes. The evolutions of temporal and spectral dynamics with different orientation angles of the extra HWP are investigated. A fully modulated stable QML pulse train is observed experimentally. This is, to the author’s best knowledge, the first experimental work reporting QML operation without adding an extra saturable absorber inside the laser cavity. Multi-wavelength pulse laser operation, multi-pulse train continuous-wave mode-locking operation and pulse-splitting operations are also reported at certain HWP angles. The observed operational dynamics are interpreted as a mutual interaction of dispersion, non-linear effect and insertion loss. This work provides a new mechanism for fabricating cheap tuneable multi-wavelength lasers with QML pulses.

Small molecules enhance CRISPR genome editing in pluripotent stem cells.

PubMed

Yu, Chen; Liu, Yanxia; Ma, Tianhua; Liu, Kai; Xu, Shaohua; Zhang, Yu; Liu, Honglei; La Russa, Marie; Xie, Min; Ding, Sheng; Qi, Lei S

2015-02-05

The bacterial CRISPR-Cas9 system has emerged as an effective tool for sequence-specific gene knockout through non-homologous end joining (NHEJ), but it remains inefficient for precise editing of genome sequences. Here we develop a reporter-based screening approach for high-throughput identification of chemical compounds that can modulate precise genome editing through homology-directed repair (HDR). Using our screening method, we have identified small molecules that can enhance CRISPR-mediated HDR efficiency, 3-fold for large fragment insertions and 9-fold for point mutations. Interestingly, we have also observed that a small molecule that inhibits HDR can enhance frame shift insertion and deletion (indel) mutations mediated by NHEJ. The identified small molecules function robustly in diverse cell types with minimal toxicity. The use of small molecules provides a simple and effective strategy to enhance precise genome engineering applications and facilitates the study of DNA repair mechanisms in mammalian cells. Copyright © 2015 Elsevier Inc. All rights reserved.

Overview of the ATLAS Insertable B-Layer (IBL) Project

NASA Astrophysics Data System (ADS)

Kagan, M. A.

2014-06-01

The first upgrade for the Pixel Detector will be a new pixel layer which is currently under construction and will be installed during the first shutdown of the LHC machine, in 2013-14. The new detector, called the Insertable B-layer (IBL), will be installed between the existing Pixel Detector and a new, smaller radius beam-pipe. Two different silicon sensor technologies, planar n-in-n and 3D, will be used, connected with the new generation 130nm IBM CMOS FE-I4 readout chip via solder bump-bonds. A production quality control test bench was set up in the ATLAS inner detector assembly clean room to verify and rate the performance of the detector elements before integration around the beam-pipe. An overview of the IBL project, of the module design, the qualification for these sensor technologies, the integration quality control setups and recent results in the construction of this full scale new concept detector is discussed.

Efficient generation and characterization of spectrally factorable biphotons.

PubMed

Chen, Changchen; Bo, Cao; Niu, Murphy Yuezhen; Xu, Feihu; Zhang, Zheshen; Shapiro, Jeffrey H; Wong, Franco N C

2017-04-03

Spectrally unentangled biphotons with high single-spatiotemporal-mode purity are highly desirable for many quantum information processing tasks. We generate biphotons with an inferred heralded-state spectral purity of 99%, the highest to date without any spectral filtering, by pulsed spontaneous parametric downconversion in a custom-fabricated periodically-poled KTiOPO₄ crystal under extended Gaussian phase-matching conditions. To efficiently characterize the joint spectral intensity of the generated biphotons at high spectral resolution, we employ a commercially available dispersion compensation module (DCM) with a dispersion equivalent to 100 km of standard optical fiber and with an insertion loss of only 2.8 dB. Compared with the typical method of using two temperature-stabilized equal-length fibers that incurs an insertion loss of 20 dB per fiber, the DCM approach achieves high spectral resolution in a much shorter measurement time. Because the dispersion amount and center wavelengths of DCMs can be easily customized, spectral characterization in a wide range of quantum photonic applications should benefit significantly from this technique.

A 6-amino acid insertion/deletion polymorphism in the mucin domain of TIM-1 confers protections against HIV-1 infection.

PubMed

Biasin, Mara; Sironi, Manuela; Saulle, Irma; Pontremoli, Chiara; Garziano, Micaela; Cagliani, Rachele; Trabattoni, Daria; Lo Caputo, Sergio; Vichi, Francesca; Mazzotta, Francesco; Forni, Diego; Riva, Stefania; Aguilar-Jimenez, Wbeimar; Cedeño, Samandhy; Sanchez, Jorge; Brander, Christian; Zapata, Wildeman; Rugeles, Maria Teresa; Clerici, Mario

2017-01-01

We investigated whether a 6-amino acid insertion/deletion polymorphism in the mucin domain of TIM-1 (T-cell immunoglobulin and mucin domain 1), modulates susceptibility to HIV-1 infection. The polymorphism was genotyped in three case/control cohorts of HIV-1 exposed seronegative individuals (HESN) and HIV-1 infected subjects from Italy, Peru, and Colombia; data from a Thai population were retrieved from the literature. Across all cohorts, homozygosity for the short TIM-1 allele was more common in HESNs than in HIV-1 infected subjects. A meta-analysis of the four association analyses yielded a p value of 0.005. In vitro infection assays of CD4+ T lymphocytes indicated that homozygosity for the short allele is associated with lower rate of HIV-1 replication. These results suggest that the deletion allele protects from HIV-1 infection with a recessive effect. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Nursing faculty teaching a module in clinical skills to medical students: a Lebanese experience.

PubMed

Abdallah, Bahia; Irani, Jihad; Sailian, Silva Dakessian; Gebran, Vicky George; Rizk, Ursula

2014-01-01

Nursing faculty teaching medical students a module in clinical skills is a relatively new trend. Collaboration in education among medical and nursing professions can improve students' performance in clinical skills and consequently positively impact the quality of care delivery. In 2011, the Faculty of Medicine in collaboration with the Faculty of Health Sciences at the University of Balamand, Beirut, Lebanon, launched a module in clinical skills as part of clinical skills teaching to first-year medical students. The module is prepared and delivered by nursing faculty in a laboratory setting. It consists of informative lectures as well as hands-on clinical practice. The clinical competencies taught are hand-washing, medication administration, intravenous initiation and removal, and nasogastric tube insertion and removal. Around sixty-five medical students attend this module every year. A Likert scale-based questionnaire is used to evaluate their experience. Medical students agree that the module provides adequate opportunities to enhance clinical skills and knowledge and favor cross-professional education between nursing and medical disciplines. Most of the respondents report that this experience prepares them better for clinical rotations while increasing their confidence and decreasing anxiety level. Medical students highly appreciate the nursing faculties' expertise and perceive them as knowledgeable and resourceful. Nursing faculty participating in medical students' skills teaching is well perceived, has a positive impact, and shows nurses are proficient teachers to medical students. Cross professional education is an attractive model when it comes to teaching clinical skills in medical school.

Design of a graphene-based dual-slot hybrid plasmonic electro-absorption modulator with high-modulation efficiency and broad optical bandwidth for on-chip communication.

PubMed

Wu, Zhongwei; Xu, Yin

2018-04-20

The hybrid plasmonic effect with lower loss and comparable light confinement than surface plasmon polariton opens new avenues for strengthening light-matter interactions with low loss. Here, we propose and numerically analyze a graphene-based electro-absorption modulator (EAM) with high-modulation efficiency and broad optical bandwidth using a dual-slot hybrid plasmonic waveguide (HPW), which consists of a central dual-slot HPW connected with two taper transitions and two additional dual-slot HPWs for coupling it with the input and output silicon nanowires, where graphene layers are located at the bottom and top side of the whole dual-slot HPW region. By combining the huge light enhancement effect of the dual-slot HPW and graphene's tunable conductivity, we obtain a high-modulation efficiency (ME) of 1.76 dB/μm for the graphene-based dual-slot HPW (higher ME of 2.19 dB/μm can also be obtained). Based upon this promising result, we further design a graphene-based hybrid plasmonic EAM, achieving a modulation depth (MD) of 15.95 dB and insertion loss of 1.89 dB @1.55 μm, respectively, in a total length of only 10 μm, where its bandwidth can reach over 500 nm for keeping MD>15  dB; MD can also be improved by slightly increasing the device length or shrinking the waveguide thickness, showing strong advantages for applying it into on-chip high-performance silicon modulators.

Task-discriminative space-by-time factorization of muscle activity

PubMed Central

Delis, Ioannis; Panzeri, Stefano; Pozzo, Thierry; Berret, Bastien

2015-01-01

Movement generation has been hypothesized to rely on a modular organization of muscle activity. Crucial to this hypothesis is the ability to perform reliably a variety of motor tasks by recruiting a limited set of modules and combining them in a task-dependent manner. Thus far, existing algorithms that extract putative modules of muscle activations, such as Non-negative Matrix Factorization (NMF), identify modular decompositions that maximize the reconstruction of the recorded EMG data. Typically, the functional role of the decompositions, i.e., task accomplishment, is only assessed a posteriori. However, as motor actions are defined in task space, we suggest that motor modules should be computed in task space too. In this study, we propose a new module extraction algorithm, named DsNM3F, that uses task information during the module identification process. DsNM3F extends our previous space-by-time decomposition method (the so-called sNM3F algorithm, which could assess task performance only after having computed modules) to identify modules gauging between two complementary objectives: reconstruction of the original data and reliable discrimination of the performed tasks. We show that DsNM3F recovers the task dependence of module activations more accurately than sNM3F. We also apply it to electromyographic signals recorded during performance of a variety of arm pointing tasks and identify spatial and temporal modules of muscle activity that are highly consistent with previous studies. DsNM3F achieves perfect task categorization without significant loss in data approximation when task information is available and generalizes as well as sNM3F when applied to new data. These findings suggest that the space-by-time decomposition of muscle activity finds robust task-discriminating modular representations of muscle activity and that the insertion of task discrimination objectives is useful for describing the task modulation of module recruitment. PMID:26217213

Task-discriminative space-by-time factorization of muscle activity.

PubMed

Delis, Ioannis; Panzeri, Stefano; Pozzo, Thierry; Berret, Bastien

2015-01-01

Movement generation has been hypothesized to rely on a modular organization of muscle activity. Crucial to this hypothesis is the ability to perform reliably a variety of motor tasks by recruiting a limited set of modules and combining them in a task-dependent manner. Thus far, existing algorithms that extract putative modules of muscle activations, such as Non-negative Matrix Factorization (NMF), identify modular decompositions that maximize the reconstruction of the recorded EMG data. Typically, the functional role of the decompositions, i.e., task accomplishment, is only assessed a posteriori. However, as motor actions are defined in task space, we suggest that motor modules should be computed in task space too. In this study, we propose a new module extraction algorithm, named DsNM3F, that uses task information during the module identification process. DsNM3F extends our previous space-by-time decomposition method (the so-called sNM3F algorithm, which could assess task performance only after having computed modules) to identify modules gauging between two complementary objectives: reconstruction of the original data and reliable discrimination of the performed tasks. We show that DsNM3F recovers the task dependence of module activations more accurately than sNM3F. We also apply it to electromyographic signals recorded during performance of a variety of arm pointing tasks and identify spatial and temporal modules of muscle activity that are highly consistent with previous studies. DsNM3F achieves perfect task categorization without significant loss in data approximation when task information is available and generalizes as well as sNM3F when applied to new data. These findings suggest that the space-by-time decomposition of muscle activity finds robust task-discriminating modular representations of muscle activity and that the insertion of task discrimination objectives is useful for describing the task modulation of module recruitment.

Intracisternal A-Particle Element Transposition into the Murine β-Glucuronidase Gene Correlates with Loss of Enzyme Activity: a New Model for β-Glucuronidase Deficiency in the C3H Mouse†

PubMed Central

Gwynn, Babette; Lueders, Kira; Sands, Mark S.; Birkenmeier, Edward H.

1998-01-01

The severity of human mucopolysaccharidosis type VII (MPS VII), or Sly syndrome, depends on the relative activity of the enzyme β-glucuronidase. Loss of β-glucuronidase activity can cause hydrops fetalis, with in utero or postnatal death of the patient. In this report, we show that β-glucuronidase activity is not detectable by a standard fluorometric assay in C3H/HeOuJ (C3H) mice homozygous for a new mutation, gusmps2J. These gusmps2J/gusmps2J mice are born and survive much longer than the previously characterized β-glucuronidase-null B6.C-H-2bm1/ByBir-gusmps (gusmps/gusmps) mice. Northern blot analysis of liver from gusmps2J/gusmps2J mice demonstrates a 750-bp reduction in size of β-glucuronidase mRNA. A 5.4-kb insertion in the Gus-sh nucleotide sequence from these mice was localized by Southern blot analysis to intron 8. The ends of the inserted sequences were cloned by inverse PCR and revealed an intracisternal A-particle (IAP) element inserted near the 3′ end of the intron. The sequence of the long terminal repeat (LTR) regions of the IAP most closely matches that of a composite LTR found in transposed IAPs previously identified in the C3H strain. The inserted IAP may contribute to diminished β-glucuronidase activity either by interfering with transcription or by destabilizing the message. The resulting phenotype is much less severe than that previously described in the gusmps/gusmps mouse and provides an opportunity to study MPS VII on a genetic background that clearly modulates disease severity. PMID:9774663

Altered Viral Replication and Cell Responses by Inserting MicroRNA Recognition Element into PB1 in Pandemic Influenza A Virus (H1N1) 2009

PubMed Central

Shen, Xiaoyue; Sun, Wenkui; Shi, Yi; Xing, Zheng; Su, Xin

2015-01-01

Objective. MicroRNAs (miRNAs) are endogenous noncoding RNAs that spatiotemporally modulate mRNAs in a posttranscriptional manner. Engineering mutant viruses by inserting cell-specific miRNA recognition element (MRE) into viral genome may alter viral infectivity and host responses in vital tissues and organs infected with pandemic influenza A virus (H1N1) 2009 (H1N1pdm). Methods. In this study, we employed reverse genetics approach to generate a recombinant H1N1pdm with a cell-specific miRNA target sequence inserted into its PB1 genomic segment to investigate whether miRNAs are able to suppress H1N1pdm replication. We inserted an MRE of microRNA-let-7b (miR-let-7b) into the open reading frame of PB1 to test the feasibility of creating a cell-restricted H1N1pdm virus since let-7b is abundant in human bronchial epithelial cells. Results. miR-let-7b is rich in human bronchial epithelial cells (HBE). Incorporation of the miR-let-7b-MRE confers upon the recombinant H1N1pdm virus susceptibility to miR-let-7b targeting, suggesting that the H1N1pdm and influenza A viruses can be engineered to exert the desired replication restrictive effect and decrease infectivity in vital tissues and organs. Conclusions. This approach provides an additional layer of biosafety and thus has great potential for the application in the rational development of safer and more effective influenza viral vaccines. PMID:25788763

Modulation of serpin reaction through stabilization of transient intermediate by ligands bound to alpha-helix F.

PubMed

Komissarov, Andrey A; Zhou, Aiwu; Declerck, Paul J

2007-09-07

Mechanism-based inhibition of proteinases by serpins involves enzyme acylation and fast insertion of the reactive center loop (RCL) into the central beta-sheet of the serpin, resulting in mechanical inactivation of the proteinase. We examined the effects of ligands specific to alpha-helix F (alphaHF) of plasminogen activator inhibitor-1 (PAI-1) on the stoichiometry of inhibition (SI) and limiting rate constant (k(lim)) of RCL insertion for reactions with beta-trypsin, tissue-type plasminogen activator (tPA), and urokinase. The somatomedin B domain of vitronectin (SMBD) did not affect SI for any proteinase or k(lim) for tPA but decreased the k(lim) for beta-trypsin. In contrast to SMBD, monoclonal antibodies MA-55F4C12 and MA-33H1F7, the epitopes of which are located at the opposite side of alphaHF, decreased k(lim) and increased SI for every enzyme. These effects were enhanced in the presence of SMBD. RCL insertion for beta-trypsin and tPA is limited by different subsequent steps of PAI-1 mechanism as follows: enzyme acylation and formation of a loop-displaced acyl complex (LDA), respectively. Stabilization of LDA through the disruption of the exosite interactions between PAI-1 and tPA induced an increase in the k(lim) but did not affect the SI. Thus it is unlikely that LDA contributes significantly to the outcome of the serpin reaction. These results demonstrate that the rate of RCL insertion is not necessarily correlated with SI and indicate that an intermediate, different from LDA, which forms during the late steps of PAI-1 mechanism, and could be stabilized by ligands specific to alphaHF, controls bifurcation between the inhibitory and the substrate pathways.

Optimization-based scatter estimation using primary modulation for computed tomography

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

Chen, Yi; Ma, Jingchen; Zhao, Jun, E-mail: junzhao

Purpose: Scatter reduces the image quality in computed tomography (CT), but scatter correction remains a challenge. A previously proposed primary modulation method simultaneously obtains the primary and scatter in a single scan. However, separating the scatter and primary in primary modulation is challenging because it is an underdetermined problem. In this study, an optimization-based scatter estimation (OSE) algorithm is proposed to estimate and correct scatter. Methods: In the concept of primary modulation, the primary is modulated, but the scatter remains smooth by inserting a modulator between the x-ray source and the object. In the proposed algorithm, an objective function ismore » designed for separating the scatter and primary. Prior knowledge is incorporated in the optimization-based framework to improve the accuracy of the estimation: (1) the primary is always positive; (2) the primary is locally smooth and the scatter is smooth; (3) the location of penumbra can be determined; and (4) the scatter-contaminated data provide knowledge about which part is smooth. Results: The simulation study shows that the edge-preserving weighting in OSE improves the estimation accuracy near the object boundary. Simulation study also demonstrates that OSE outperforms the two existing primary modulation algorithms for most regions of interest in terms of the CT number accuracy and noise. The proposed method was tested on a clinical cone beam CT, demonstrating that OSE corrects the scatter even when the modulator is not accurately registered. Conclusions: The proposed OSE algorithm improves the robustness and accuracy in scatter estimation and correction. This method is promising for scatter correction of various kinds of x-ray imaging modalities, such as x-ray radiography, cone beam CT, and the fourth-generation CT.« less

Space Launch System Co-Manifested Payload Options for Habitation

NASA Technical Reports Server (NTRS)

Smitherman, David

2015-01-01

The Space Launch System (SLS) has a co-manifested payload capability that will grow over time as the rocket matures and planned upgrades are implemented. The final configuration is planned to be capable of inserting a payload greater than 10 metric tons (mt) into a trans-lunar injection trajectory along with the crew in the Orion capsule and the service module. The co-manifested payload is located below the Orion and its service module in a 10-meter high fairing similar to the way the Saturn launch vehicle carried the lunar lander below the Apollo command and service modules. A variety of approaches have been explored that utilizes this co-manifested payload capability to build up infrastructure in deep space in support of future asteroid, lunar, and Mars mission scenarios. This paper is a report on the findings from the Advanced Concepts Office study team at the NASA Marshall Space Flight Center, working with the Advanced Exploration Systems Program on the Exploration Augmentation Module Project. It includes some of the possible options for habitation in the co-manifested payload volume on SLS. Findings include module designs that can be developed in 10mt increments to support these missions, including overall conceptual layouts, mass properties, and approaches for integration into various scenarios for near-term support of deep space habitat research and technology development, support to asteroid exploration, and long range support for Mars transfer flights.

Chimeric cellulase matrix for investigating intramolecular synergism between non-hydrolytic disruptive functions of carbohydrate-binding modules and catalytic hydrolysis.

PubMed

Wang, Yuguo; Tang, Rentao; Tao, Jin; Wang, Xiaonan; Zheng, Baisong; Feng, Yan

2012-08-24

The conversion of renewable cellulosic biomass is of considerable interest for the production of biofuels and materials. The bottleneck in the efficient conversion is the compactness and resistance of crystalline cellulose. Carbohydrate-binding modules (CBMs), which disrupt crystalline cellulose via non-hydrolytic mechanisms, are expected to overcome this bottleneck. However, the lack of convenient methods for quantitative analysis of the disruptive functions of CBMs have hindered systematic studies and molecular modifications. Here we established a practical and systematic platform for quantifying and comparing the non-hydrolytic disruptive activities of CBMs via the synergism of CBMs and a catalytic module within designed chimeric cellulase molecules. Bioinformatics and computational biology were also used to provide a deeper understanding. A convenient vector was constructed to serve as a cellulase matrix into which heterologous CBM sequences can be easily inserted. The resulting chimeric cellulases were suitable for studying disruptive functions, and their activities quantitatively reflected the disruptive functions of CBMs on crystalline cellulose. In addition, this cellulase matrix can be used to construct novel chimeric cellulases with high hydrolytic activities toward crystalline cellulose.

Extreme mobility enhancement of two-dimensional electron gases at oxide interfaces by charge-transfer-induced modulation doping

NASA Astrophysics Data System (ADS)

Chen, Y. Z.; Trier, F.; Wijnands, T.; Green, R. J.; Gauquelin, N.; Egoavil, R.; Christensen, D. V.; Koster, G.; Huijben, M.; Bovet, N.; Macke, S.; He, F.; Sutarto, R.; Andersen, N. H.; Sulpizio, J. A.; Honig, M.; Prawiroatmodjo, G. E. D. K.; Jespersen, T. S.; Linderoth, S.; Ilani, S.; Verbeeck, J.; van Tendeloo, G.; Rijnders, G.; Sawatzky, G. A.; Pryds, N.

2015-08-01

Two-dimensional electron gases (2DEGs) formed at the interface of insulating complex oxides promise the development of all-oxide electronic devices. These 2DEGs involve many-body interactions that give rise to a variety of physical phenomena such as superconductivity, magnetism, tunable metal-insulator transitions and phase separation. Increasing the mobility of the 2DEG, however, remains a major challenge. Here, we show that the electron mobility is enhanced by more than two orders of magnitude by inserting a single-unit-cell insulating layer of polar La1-xSrxMnO3 (x = 0, 1/8, and 1/3) at the interface between disordered LaAlO3 and crystalline SrTiO3 produced at room temperature. Resonant X-ray spectroscopy and transmission electron microscopy show that the manganite layer undergoes unambiguous electronic reconstruction, leading to modulation doping of such atomically engineered complex oxide heterointerfaces. At low temperatures, the modulation-doped 2DEG exhibits Shubnikov-de Haas oscillations and fingerprints of the quantum Hall effect, demonstrating unprecedented high mobility and low electron density.

LINE dancing in the human genome: transposable elements and disease.

PubMed

Belancio, Victoria P; Deininger, Prescott L; Roy-Engel, Astrid M

2009-10-27

Transposable elements (TEs) have been consistently underestimated in their contribution to genetic instability and human disease. TEs can cause human disease by creating insertional mutations in genes, and also contributing to genetic instability through non-allelic homologous recombination and introduction of sequences that evolve into various cis-acting signals that alter gene expression. Other outcomes of TE activity, such as their potential to cause DNA double-strand breaks or to modulate the epigenetic state of chromosomes, are less fully characterized. The currently active human transposable elements are members of the non-LTR retroelement families, LINE-1, Alu (SINE), and SVA. The impact of germline insertional mutagenesis by TEs is well established, whereas the rate of post-insertional TE-mediated germline mutations and all forms of somatic mutations remain less well quantified. The number of human diseases discovered to be associated with non-allelic homologous recombination between TEs, and particularly between Alu elements, is growing at an unprecedented rate. Improvement in the technology for detection of such events, as well as the mounting interest in the research and medical communities in resolving the underlying causes of the human diseases with unknown etiology, explain this increase. Here, we focus on the most recent advances in understanding of the impact of the active human TEs on the stability of the human genome and its relevance to human disease.

Insertion of targeting domains into the envelope glycoprotein of Moloney murine leukemia virus (MoMLV)-based vectors modulates the route of mCAT-1-mediated viral entry.

PubMed

Viejo-Borbolla, A; Pizzato, M; Blair, E D; Schulz, T F

2005-03-01

Several groups have inserted targeting domains into the envelope glycoprotein (Env) of Moloney murine leukemia virus (MoMLV) in an attempt to produce targeted retroviral vectors for human gene therapy. While binding of these modified Envs to the target molecule expressed on the surface of human cells was observed, specific high-titer infection of human cells expressing the target molecule was not achieved. Here we investigate the initial steps in the entry process of targeted MoMLV vectors both in murine and human cells expressing the MoMLV receptor, the mouse cationic amino acid transporter-1 (mCAT-1). We show that insertion of a small ligand targeted to E-selectin and of a single chain antibody (scFv) targeted to folate-binding protein (FBP) into the N-terminus of MoMLV Env results in the reduction of the infectivity and the kinetics of entry of the MoMLV vectors. The use of soluble receptor-binding domain (sRBD), bafilomycin A1 (BafA1) and methyl-beta-cyclodextrin (MbetaC) increase the infectivity of the MoMLV vectors targeted to FBP (MoMLV-FBP) suggesting that the scFv targeted to FBP increases the threshold for fusion and might re-route entry of the targeted MoMLV-FBP vector towards an endocytic, non-productive pathway.

Characterization of the Heat Extraction Capability of a Compliant, Sliding, Thermal Interface for Use in a High Temperature, Vacuum, Microgravity Furnace

NASA Technical Reports Server (NTRS)

Bellomy-Ezell, Jenny; Farmer, Jeff; Breeding, Shawn; Spivey, Reggie

2001-01-01

A compliant, thermal interface material is tested to evaluate its thermal behavior at elevated temperatures, in vacuum conditions, and under varying levels of compression. Preliminary results indicate that the thermal performance of this polymer fiber-based, felt-like material is sufficient to meet thermal extraction requirements for the Quench Module Insert, a Bridgman furnace for microgravity material science investigation. This paper discusses testing and modeling approaches employed, gives of a status of characterization activities and provides preliminary test results.

A Survey of Power Electronics Applications in Aerospace Technologies

NASA Technical Reports Server (NTRS)

Kankam, M. David; Elbuluk, Malik E.

2001-01-01

The insertion of power electronics in aerospace technologies is becoming widespread. The application of semiconductor devices and electronic converters, as summarized in this paper, includes the International Space Station, satellite power system, and motor drives in 'more electric' technology applied to aircraft, starter/generators and reusable launch vehicles. Flywheels, servo systems embodying electromechanical actuation, and spacecraft on-board electric propulsion are discussed. Continued inroad by power electronics depends on resolving incompatibility of using variable frequency for 400 Hz-operated aircraft equipment. Dual-use electronic modules should reduce system development cost.

Evaluation of the Use of Optical Fiber Thermometers for Thermal Control of the Quench Module Insert

NASA Technical Reports Server (NTRS)

Jones, Matthew R.; Farmer, Jeffrey T.; Breeding, Shawn P.

2001-01-01

Issues regarding the use of optical fiber thermometers to control heater settings in a microgravity vacuum furnace are addressed. It is desirable to use these probes in environments such as the International Space Station, because they can be operated without re-calibration for extended periods. However, the analysis presented in this paper shows that temperature readings obtained using optical fiber thermometers can be corrupted by emissions from the fiber when extended portions of the probe are exposed to elevated temperatures.

Evaluation of the Use of Optical Fiber Thermometers for Thermal Control of the Quench Module Insert

NASA Technical Reports Server (NTRS)

Jones, Matthew R.; Farmer, Jeffrey T.; Breeding, Shawn P.

1999-01-01

Issues regarding the use of optical fiber thermometers to control heater settings in a microgravity vacuum furnace are addressed. It is desirable to use these probes in environments such as the International Space Station, because they can be operated without re-calibration for extended periods. However, the analysis presented in this paper shows that temperature readings obtained using optical fiber thermometers are corrupted due to emissions from the fiber when extended portions of the probe are exposed to elevated temperatures.

A prototype MR insertable brain PET using tileable GAPD arrays.

PubMed

Hong, Key Jo; Choi, Yong; Jung, Jin Ho; Kang, Jihoon; Hu, Wei; Lim, Hyun Keong; Huh, Yoonsuk; Kim, Sangsu; Jung, Ji Woong; Kim, Kyu Bom; Song, Myung Sung; Park, Hyun-Wook

2013-04-01

The aim of this study was to develop a prototype magnetic resonance (MR)-compatible positron emission tomography (PET) that can be inserted into a MR imager and that allows simultaneous PET and MR imaging of the human brain. This paper reports the initial results of the authors' prototype brain PET system operating within a 3-T magnetic resonance imaging (MRI) system using newly developed Geiger-mode avalanche photodiode (GAPD)-based PET detectors, long flexible flat cables, position decoder circuit with high multiplexing ratio, and digital signal processing with field programmable gate array-based analog to digital converter boards. A brain PET with 72 detector modules arranged in a ring was constructed and mounted in a 3-T MRI. Each PET module was composed of cerium-doped lutetium yttrium orthosilicate (LYSO) crystals coupled to a tileable GAPD. The GAPD output charge signals were transferred to preamplifiers using 3 m long flat cables. The LYSO and GAPD were located inside the MR bore and all electronics were positioned outside the MR bore. The PET detector performance was investigated both outside and inside the MRI, and MR image quality was evaluated with and without the PET system. The performance of the PET detector when operated inside the MRI during MR image acquisition showed no significant change in energy resolution and count rates, except for a slight degradation in timing resolution with an increase from 4.2 to 4.6 ns. Simultaneous PET/MR images of a hot-rod and Hoffman brain phantom were acquired in a 3-T MRI. Rods down to a diameter of 3.5 mm were resolved in the hot-rod PET image. The activity distribution patterns between the white and gray matter in the Hoffman brain phantom were well imaged. The hot-rod and Hoffman brain phantoms on the simultaneously acquired MR images obtained with standard sequences were observed without any noticeable artifacts, although MR image quality requires some improvement. These results demonstrate that the simultaneous acquisition of PET and MR images is feasible using the MR insertable PET developed in this study.

SU-E-J-104: Single Photon Image From PET with Insertable SPECT Collimator for Boron Neutron Capture Therapy: A Feasibility Study

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

Jung, J; Yoon, D; Suh, T

2014-06-01

Purpose: The aim of our proposed system is to confirm the feasibility of extraction of two types of images from one positron emission tomography (PET) module with an insertable collimator for brain tumor treatment during the BNCT. Methods: Data from the PET module, neutron source, and collimator was entered in the Monte Carlo n-particle extended (MCNPX) source code. The coincidence events were first compiled on the PET detector, and then, the events of the prompt gamma ray were collected after neutron emission by using a single photon emission computed tomography (SPECT) collimator on the PET. The obtaining of full widthmore » at half maximum (FWHM) values from the energy spectrum was performed to collect effective events for reconstructed image. In order to evaluate the images easily, five boron regions in a brain phantom were used. The image profiles were extracted from the region of interest (ROI) of a phantom. The image was reconstructed using the ordered subsets expectation maximization (OSEM) reconstruction algorithm. The image profiles and the receiver operating characteristic (ROC) curve were compiled for quantitative analysis from the two kinds of reconstructed image. Results: The prompt gamma ray energy peak of 478 keV appeared in the energy spectrum with a FWHM of 41 keV (6.4%). On the basis of the ROC curve in Region A to Region E, the differences in the area under the curve (AUC) of the PET and SPECT images were found to be 10.2%, 11.7%, 8.2% (center, Region C), 12.6%, and 10.5%, respectively. Conclusion: We attempted to acquire the PET and SPECT images simultaneously using only PET without an additional isotope. Single photon images were acquired using an insertable collimator on a PET detector. This research was supported by the Leading Foreign Research Institute Recruitment Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, Information and Communication Technologies (ICT) and Future Planning (MSIP)(Grant No.2009 00420) and the Radiation Technology R and D program (Grant No.2013M2A2A7043498), Republic of Korea.« less

A compact high resolution flat panel PET detector based on the new 4-side buttable MPPC for biomedical applications

PubMed Central

Wang, Qiang; Wen, Jie; Ravindranath, Bosky; O’Sullivan, Andrew W.; Catherall, David; Li, Ke; Wei, Shouyi; Komarov, Sergey; Tai, Yuan-Chuan

2015-01-01

Compact high-resolution panel detectors using virtual pinhole (VP) PET geometry can be inserted into existing clinical or pre-clinical PET systems to improve regional spatial resolution and sensitivity. Here we describe a compact panel PET detector built using the new Though Silicon Via (TSV) multi-pixel photon counters (MPPC) detector. This insert provides high spatial resolution and good timing performance for multiple bio-medical applications. Because the TSV MPPC design eliminates wire bonding and has a package dimension which is very close to the MPPC’s active area, it is 4-side buttable. The custom designed MPPC array (based on Hamamatsu S12641-PA-50(x)) used in the prototype is composed of 4 × 4 TSV-MPPC cells with a 4.46 mm pitch in both directions. The detector module has 16 × 16 lutetium yttrium oxyorthosilicate (LYSO) crystal array, with each crystal measuring 0.92 × 0.92 × 3 mm3 with 1.0 mm pitch. The outer diameter of the detector block is 16.8 × 16.8 mm2. Thirty-two such blocks will be arranged in a 4 × 8 array with 1 mm gaps to form a panel detector with detection area around 7 cm × 14 cm in the full-size detector. The flood histogram acquired with Ge-68 source showed excellent crystal separation capability with all 256 crystals clearly resolved. The detector module’s mean, standard deviation, minimum (best) and maximum (worst) energy resolution were 10.19%, +/−0.68%, 8.36% and 13.45% FWHM, respectively. The measured coincidence time resolution between the block detector and a fast reference detector (around 200 ps single photon timing resolution) was 0.95 ns. When tested with Siemens Cardinal electronics the performance of the detector blocks remain consistent. These results demonstrate that the TSV-MPPC is a promising photon sensor for use in a flat panel PET insert composed of many high resolution compact detector modules. PMID:26085702

Imperfect duplicate insertions type of mutations in plasmepsin V modulates binding properties of PEXEL motifs of export proteins in Indian Plasmodium vivax.

PubMed

Rawat, Manmeet; Vijay, Sonam; Gupta, Yash; Tiwari, Pramod Kumar; Sharma, Arun

2013-01-01

Plasmepsin V (PM-V) have functionally conserved orthologues across the Plasmodium genus who's binding and antigenic processing at the PEXEL motifs for export about 200-300 essential proteins is important for the virulence and viability of the causative Plasmodium species. This study was undertaken to determine P. vivax plasmepsin V Ind (PvPM-V-Ind) PEXEL motif export pathway for pathogenicity-related proteins/antigens export thereby altering plasmodium exportome during erythrocytic stages. We identify and characterize Plasmodium vivax plasmepsin-V-Ind (mutant) gene by cloning, sequence analysis, in silico bioinformatic protocols and structural modeling predictions based on docking studies on binding capacity with PEXEL motifs processing in terms of binding and accessibility of export proteins. Cloning and sequence analysis for genetic diversity demonstrates PvPM-V-Ind (mutant) gene is highly conserved among all isolates from different geographical regions of India. Imperfect duplicate insertion types of mutations (SVSE from 246-249 AA and SLSE from 266-269 AA) were identified among all Indian isolates in comparison to P.vivax Sal-1 (PvPM-V-Sal 1) isolate. In silico bioinformatics interaction studies of PEXEL peptide and active enzyme reveal that PvPM-V-Ind (mutant) is only active in endoplasmic reticulum lumen and membrane embedding is essential for activation of plasmepsin V. Structural modeling predictions based on docking studies with PEXEL motif show significant variation in substrate protein binding of these imperfect mutations with data mined PEXEL sequences. The predicted variation in the docking score and interacting amino acids of PvPM-V-Ind (mutant) proteins with PEXEL and lopinavir suggests a modulation in the activity of PvPM-V in terms of binding and accessibility at these sites. Our functional modeled validation of PvPM-V-Ind (mutant) imperfect duplicate insertions with data mined PEXEL sequences leading to altered binding and substrate accessibility of the enzyme makes it a plausible target to investigate export mechanisms for in silico virtual screening and novel pharmacophore designing.

Imperfect Duplicate Insertions Type of Mutations in Plasmepsin V Modulates Binding Properties of PEXEL Motifs of Export Proteins in Indian Plasmodium vivax

PubMed Central

Rawat, Manmeet; Vijay, Sonam; Gupta, Yash; Tiwari, Pramod Kumar; Sharma, Arun

2013-01-01

Introduction Plasmepsin V (PM-V) have functionally conserved orthologues across the Plasmodium genus who's binding and antigenic processing at the PEXEL motifs for export about 200–300 essential proteins is important for the virulence and viability of the causative Plasmodium species. This study was undertaken to determine P. vivax plasmepsin V Ind (PvPM-V-Ind) PEXEL motif export pathway for pathogenicity-related proteins/antigens export thereby altering plasmodium exportome during erythrocytic stages. Method We identify and characterize Plasmodium vivax plasmepsin-V-Ind (mutant) gene by cloning, sequence analysis, in silico bioinformatic protocols and structural modeling predictions based on docking studies on binding capacity with PEXEL motifs processing in terms of binding and accessibility of export proteins. Results Cloning and sequence analysis for genetic diversity demonstrates PvPM-V-Ind (mutant) gene is highly conserved among all isolates from different geographical regions of India. Imperfect duplicate insertion types of mutations (SVSE from 246–249 AA and SLSE from 266–269 AA) were identified among all Indian isolates in comparison to P.vivax Sal-1 (PvPM-V-Sal 1) isolate. In silico bioinformatics interaction studies of PEXEL peptide and active enzyme reveal that PvPM-V-Ind (mutant) is only active in endoplasmic reticulum lumen and membrane embedding is essential for activation of plasmepsin V. Structural modeling predictions based on docking studies with PEXEL motif show significant variation in substrate protein binding of these imperfect mutations with data mined PEXEL sequences. The predicted variation in the docking score and interacting amino acids of PvPM-V-Ind (mutant) proteins with PEXEL and lopinavir suggests a modulation in the activity of PvPM-V in terms of binding and accessibility at these sites. Conclusion/Significance Our functional modeled validation of PvPM-V-Ind (mutant) imperfect duplicate insertions with data mined PEXEL sequences leading to altered binding and substrate accessibility of the enzyme makes it a plausible target to investigate export mechanisms for in silico virtual screening and novel pharmacophore designing. PMID:23555891

Can unaided non-linguistic measures predict cochlear implant candidacy?

PubMed Central

Shim, Hyun Joon; Won, Jong Ho; Moon, Il Joon; Anderson, Elizabeth S.; Drennan, Ward R.; McIntosh, Nancy E.; Weaver, Edward M.; Rubinstein, Jay T.

2014-01-01

Objective To determine if unaided, non-linguistic psychoacoustic measures can be effective in evaluating cochlear implant (CI) candidacy. Study Design Prospective split-cohort study including predictor development subgroup and independent predictor validation subgroup. Setting Tertiary referral center. Subjects Fifteen subjects (28 ears) with hearing loss were recruited from patients visiting the University of Washington Medical Center for CI evaluation. Methods Spectral-ripple discrimination (using a 13-dB modulation depth) and temporal modulation detection using 10- and 100-Hz modulation frequencies were assessed with stimuli presented through insert earphones. Correlations between performance for psychoacoustic tasks and speech perception tasks were assessed. Receiver operating characteristic (ROC) curve analysis was performed to estimate the optimal psychoacoustic score for CI candidacy evaluation in the development subgroup and then tested in an independent sample. Results Strong correlations were observed between spectral-ripple thresholds and both aided sentence recognition and unaided word recognition. Weaker relationships were found between temporal modulation detection and speech tests. ROC curve analysis demonstrated that the unaided spectral ripple discrimination shows a good sensitivity, specificity, positive predictive value, and negative predictive value compared to the current gold standard, aided sentence recognition. Conclusions Results demonstrated that the unaided spectral-ripple discrimination test could be a promising tool for evaluating CI candidacy. PMID:24901669

Technology transfer of military space microprocessor developments

NASA Astrophysics Data System (ADS)

Gorden, C.; King, D.; Byington, L.; Lanza, D.

1999-01-01

Over the past 13 years the Air Force Research Laboratory (AFRL) has led the development of microprocessors and computers for USAF space and strategic missile applications. As a result of these Air Force development programs, advanced computer technology is available for use by civil and commercial space customers as well. The Generic VHSIC Spaceborne Computer (GVSC) program began in 1985 at AFRL to fulfill a deficiency in the availability of space-qualified data and control processors. GVSC developed a radiation hardened multi-chip version of the 16-bit, Mil-Std 1750A microprocessor. The follow-on to GVSC, the Advanced Spaceborne Computer Module (ASCM) program, was initiated by AFRL to establish two industrial sources for complete, radiation-hardened 16-bit and 32-bit computers and microelectronic components. Development of the Control Processor Module (CPM), the first of two ASCM contract phases, concluded in 1994 with the availability of two sources for space-qualified, 16-bit Mil-Std-1750A computers, cards, multi-chip modules, and integrated circuits. The second phase of the program, the Advanced Technology Insertion Module (ATIM), was completed in December 1997. ATIM developed two single board computers based on 32-bit reduced instruction set computer (RISC) processors. GVSC, CPM, and ATIM technologies are flying or baselined into the majority of today's DoD, NASA, and commercial satellite systems.

Insights from neuroenergetics into the interpretation of functional neuroimaging: an alternative empirical model for studying the brain's support of behavior

PubMed Central

Shulman, Robert G; Hyder, Fahmeed; Rothman, Douglas L

2014-01-01

Functional neuroimaging measures quantitative changes in neurophysiological parameters coupled to neuronal activity during observable behavior. These results have usually been interpreted by assuming that mental causation of behavior arises from the simultaneous actions of distinct psychological mechanisms or modules. However, reproducible localization of these modules in the brain using functional magnetic resonance imaging (MRI) and positron emission tomography (PET) imaging has been elusive other than for sensory systems. In this paper, we show that neuroenergetic studies using PET, calibrated functional magnetic resonance imaging (fMRI), 13C magnetic resonance spectroscopy, and electrical recordings do not support the standard approach, which identifies the location of mental modules from changes in brain activity. Of importance in reaching this conclusion is that changes in neuronal activities underlying the fMRI signal are many times smaller than the high ubiquitous, baseline neuronal activity, or energy in resting, awake humans. Furthermore, the incremental signal depends on the baseline activity contradicting theoretical assumptions about linearity and insertion of mental modules. To avoid these problems, while making use of these valuable results, we propose that neuroimaging should be used to identify observable brain activities that are necessary for a person's observable behavior rather than being used to seek hypothesized mental processes. PMID:25160670

Modulation doping at BaSnO3LaInO3

NASA Astrophysics Data System (ADS)

Char, Kookrin; Shin, Juyeon; Kim, Young Mo; Kim, Youjung

We recently reported on the conductance enhancement at the interface between two band insulators: LaInO3 (LIO) and BaSnO3 (BSO). These two-dimensional electron gas-like (2DEG) states at the LIO/Ba1-xLaxSnO3 (BLSO) polar interface display the stability, the controllability of the local carrier concentration, and the high electron mobility of BLSO. Search for the origin of enhanced conductance at the interface has been carried out, and one of the findings is that the doping level of BSO is a critical parameter for the polar charge contribution . We have also investigated a new modulated heterostructure by inserting an undoped BSO spacer layer at the LIO/BLSO interface. As increasing the thickness of the spacer layer, the carrier concentration and the mobility continually decreased. We attribute the results to the modified band bending as the thickness of the spacer layer varies and to the dislocation-limited transport. However, when we controlled the band bending by field effect, improved mobility was observed in these modulated heterostructures. This new modulated heterostructures of the LIO/BSO polar interface look promising not only for higher electron mobility devices but also for elucidating the mechanism of the 2DEG-like behavior. Samsung science and technology foundation.

Controlling allosteric networks in proteins

NASA Astrophysics Data System (ADS)

Dokholyan, Nikolay

2013-03-01

We present a novel methodology based on graph theory and discrete molecular dynamics simulations for delineating allosteric pathways in proteins. We use this methodology to uncover the structural mechanisms responsible for coupling of distal sites on proteins and utilize it for allosteric modulation of proteins. We will present examples where inference of allosteric networks and its rewiring allows us to ``rescue'' cystic fibrosis transmembrane conductance regulator (CFTR), a protein associated with fatal genetic disease cystic fibrosis. We also use our methodology to control protein function allosterically. We design a novel protein domain that can be inserted into identified allosteric site of target protein. Using a drug that binds to our domain, we alter the function of the target protein. We successfully tested this methodology in vitro, in living cells and in zebrafish. We further demonstrate transferability of our allosteric modulation methodology to other systems and extend it to become ligh-activatable.

Tuning emission color of electroluminescence from two organic interfacial exciplexes by modulating the thickness of middle gadolinium complex layer

NASA Astrophysics Data System (ADS)

Li, Mingtao; Li, Wenlian; Chen, Lili; Kong, Zhiguo; Chu, Bei; Li, Bin; Hu, Zhizhi; Zhang, Zhiqiang

2006-02-01

Electroluminescent colors of organic light-emitting diodes (OLEDs) can be tuned by modulating the thickness of gadolinium (Gd) complex layer sandwiched between an electron-transporting layer (ETL) and a hole-transporting layer (HTL). The emission colors, which originate from the two interfacial exciplexes simultaneously, can be tuned from green to orange by increasing the thickness of the Gd-complex layer. The atom force microscope images have proved that there are many gaps in the thinner Gd-complex layers. Therefore, besides the exciplex formation between Gd complex and HTL, the exciplex between ETL and HTL is also formed. The results demonstrate that a simple way of color tuning can be realized by inserting a thin layer of color tuning material between HTL with lower ionization potentials and ETL with higher electron affinities. Moreover, photovoltaic device and white OLED based on the two exciplexes are also discussed.

Improving a Synechocystis-based photoautotrophic chassis through systematic genome mapping and validation of neutral sites

PubMed Central

Pinto, Filipe; Pacheco, Catarina C.; Oliveira, Paulo; Montagud, Arnau; Landels, Andrew; Couto, Narciso; Wright, Phillip C.; Urchueguía, Javier F.; Tamagnini, Paula

2015-01-01

The use of microorganisms as cell factories frequently requires extensive molecular manipulation. Therefore, the identification of genomic neutral sites for the stable integration of ectopic DNA is required to ensure a successful outcome. Here we describe the genome mapping and validation of five neutral sites in the chromosome of Synechocystis sp. PCC 6803, foreseeing the use of this cyanobacterium as a photoautotrophic chassis. To evaluate the neutrality of these loci, insertion/deletion mutants were produced, and to assess their functionality, a synthetic green fluorescent reporter module was introduced. The constructed integrative vectors include a BioBrick-compatible multiple cloning site insulated by transcription terminators, constituting robust cloning interfaces for synthetic biology approaches. Moreover, Synechocystis mutants (chassis) ready to receive purpose-built synthetic modules/circuits are also available. This work presents a systematic approach to map and validate chromosomal neutral sites in cyanobacteria, and that can be extended to other organisms. PMID:26490728

Reversible unidirectional reflection and absorption of PT-symmetry structure under electro-optical modulation

NASA Astrophysics Data System (ADS)

Fang, Yun-tuan; Zhang, Yi-chi; Xia, Jing

2018-06-01

In order to obtain tunable unidirectional device, we assumed an ideal periodic layered Parity-Time (PT) symmetry structure inserted by doped LiNbO3 (LN) interlayers. LN is a typical electro-optical material of which the refractive index depends on the external electric field. In our work, we theoretically investigate the modulation effect of the external electric field on the transmittance and reflectance of the structure through numerical method. Through selected structural parameters, the one-way enhanced reflection and high absorption (above 0.9) behaviors are found. Within a special frequency band (not a single frequency), our theoretical model performs enhanced reflection in one incidence direction and high absorption in the other direction. Furthermore, the directions of enhanced reflection and absorption can be reversed through reversing the direction of applied electric field. Such structure with reversible properties has the potential in designing new optical devices.

Eliminating degradation and uncovering ion-trapping dynamics in electrochromic WO3 thin films

PubMed Central

Wen, Rui-Tao; Granqvist, Claes G.; Niklasson, Gunnar A.

2015-01-01

Amorphous WO3 thin films are of keen interest as cathodic electrodes in transmittance-modulating electrochromic devices. However, these films suffer from ion-trapping-induced degradation of optical modulation and reversibility upon extended Li+-ion exchange. Here, we demonstrate that ion-trapping-induced degradation, which is commonly believed to be irreversible, can be successfully eliminated by constant-current-driven de-trapping, i.e., WO3 films can be rejuvenated and regain their initial highly reversible electrochromic performance. Pronounced ion-trapping occurs when x exceeds ~0.65 in LixWO3 during ion insertion. We find two main kinds of Li+-ion trapping sites (intermediate and deep) in WO3, where the intermediate ones are most prevalent. Li+-ions can be completely removed from intermediate traps but are irreversibly bound in deep traps. Our results provide a general framework for developing and designing superior electrochromic materials and devices. PMID:26259104

Experimental Evaluation of a SiPM-Based Scintillation Detector for MR-Compatible SPECT Systems

NASA Astrophysics Data System (ADS)

Busca, Paolo; Occhipinti, Michele; Trigilio, Paolo; Cozzi, Giulia; Fiorini, Carlo; Piemonte, Claudio; Ferri, Alessandro; Gola, Alberto; Nagy, Kálmán; Bükki, Tamás; Rieger, Jan

2015-10-01

In the present work we briefly describe the architecture of a photo-detection module, designed in the framework of the INSERT (INtegrated SPECT/MRI for Enhanced Stratification in Radio-chemoTherapy) project, supported by the European Community. We focus on two main elements of the module: the SiPM photo-detector unit and the multi-channel ASIC. These two components have been investigated with dedicated and independent setups to assess preliminary performance of INSERT architecture. In details, we designed a 25.30 mm ×25.85 mm tile, comprising 9 pixels, each one with an 8 mm ×8 mm active area. We developed an Anger camera to characterize the tile coupled to a CsI:Tl scintillator (6 mm thick). We measured an average spatial resolution (FWHM) of 2 mm in the central region of the Field of View and a 15.3% energy resolution using a 57Co source (122 keV), when the tile is cooled down to 0 ° C to reduce the impact of the dark count rate. Furthermore, we developed ANGUS, a 36-channels 0.35 μm CMOS technology ASIC designed to cope with input capacitance up to 5 nF, typical of large area SiPM pixels. The spectroscopic capability of single readout channels were evaluated by coupling an 8 mm ×8 mm pixel with a cylindrical CsI:Tl scintillator (8 mm diameter, 10 mm thickness). Energy resolution at room temperature provided values between 13% and 13.5% (FWHM) at the 122 keV line for the nine pixels.

Can a peri-rectal hydrogel spaceOAR programme for prostate cancer intensity-modulated radiotherapy be successfully implemented in a regional setting?

PubMed

Te Velde, Bridget L; Westhuyzen, Justin; Awad, Nader; Wood, Maree; Shakespeare, Thomas P

2017-08-01

The aim of this study was to investigate whether the implementation of a hydrogel spacer (SpaceOAR) programme for patients treated with 81 Gy prostate intensity-modulated radiotherapy (IMRT) in a regional setting can reduce rectal doses and toxicity. In this retrospective study, 125 patients with localised prostate cancer treated between April 2014 (programme commencement) and June 2015 were compared: 65 with SpaceOAR (inserted by five different urologists) and 60 patients treated over the same time period without SpaceOAR. Patients were treated with 81 Gy in 45Fx of IMRT over 9 weeks. Planning aims included restricting rectal doses to V40 Gy < 35%, V65 Gy < 17%, V75 Gy < 10%. Acute toxicity was assessed weekly during radiotherapy and at 12 weeks. Rectal volume parameters were all significantly lower in the SpaceOAR group, with an associated reduction in acute diarrhoea (13.8% vs 31.7%). There were no significant differences in the very low rates of acute and late faecal incontinence or proctitis, however, there was a trend towards increased haemorrhoid rate in the SpaceOAR group (11.7% vs 3.1%, P = 0.09). A SpaceOAR programme in a regional setting with urologists performing low volumes of insertions (<1 per month on average) is of clinical benefit, and was associated with significantly lower radiation doses to the rectum and lower rates of acute diarrhoea. © 2017 The Royal Australian and New Zealand College of Radiologists.

Mitigation of nonlinear fiber distortion using optical phase conjugation for mode-division multiplexed transmission

NASA Astrophysics Data System (ADS)

Zhang, Kai; Gao, Guanjun; Zhang, Jie; Fei, Aimei; Cvijetic, Milorad

2018-07-01

We have investigated and proposed the use of optical phase conjugation (OPC) technique to mitigate the impact of fiber nonlinearities in mode-division multiplexed transmission systems. Numerical simulations are performed for three wavelengths, each loaded with 200 Gb/s dual-polarization 16-level quadrature amplitude modulation (DP-16QAM) format, in weakly guided two-mode fiber. It is known that differential mode group delay (DMGD) in mode-division multiplexed (MDM) transmission systems could be beneficial for system performance of MDM system with MIMO compensation in place. On the other side, for MDM system with OPC in place, the presence of DMGD may limit the overall benefits since signal power evolution per spatial modes should be symmetrical at the system midpoint in order to realize an effective compensation of the nonlinear effects. Our simulation results show that in the reference case (in the absence of DMGD), the employment of OPC module would lead to an average Q-factor improvement of approximately 10 dB. At the same time, in the presence of DMGD, an average Q-factor improvement would be ∼2.8 dB for WDM case. In addition, due to asymmetrical signal power map, the penalties induced by a periodic amplification process cannot be ideally compensated by the midpoint insertion of OPC. However, by accounting the impacts of both DMGD and asymmetrical signal power map, the insertion of the OPC system will still lead to an average Q-factor improvement of ∼1 dB for WDM channel arrangement.

Numerical investigations of self- and cross-phase modulation effects in high-power fiber amplifiers (Conference Presentation)

NASA Astrophysics Data System (ADS)

Zunoubi, Mohammad R.; Anderson, Brian; Naderi, Shadi A.; Madden, Timothy J.; Dajani, Iyad

2017-03-01

The development of high-power fiber lasers is of great interest due to the advantages they offer relative to other laser technologies. Currently, the maximum power from a reportedly single-mode fiber amplifier stands at 10 kW. Though impressive, this power level was achieved at the cost of a large spectral linewidth, making the laser unsuitable for coherent or spectral beam combination techniques required to reach power levels necessary for airborne tactical applications. An effective approach in limiting the SBS effect is to insert an electro-optic phase modulator at the low-power end of a master oscillator power amplifier (MOPA) system. As a result, the optical power is spread among spectral sidebands; thus raising the overall SBS threshold of the amplifier. It is the purpose of this work to present a comprehensive numerical scheme that is based on the extended nonlinear Schrodinger equations that allows for accurate analysis of phase modulated fiber amplifier systems in relation to the group velocity dispersion and Kerr nonlinearities and their effect on the coherent beam combining efficiency. As such, we have simulated a high-power MOPA system modulated via filtered pseudo-random bit sequence format for different clock rates and power levels. We show that at clock rates of ≥30 GHz, the combination of GVD and self-phase modulation may lead to a drastic drop in beam combining efficiency at the multi-kW level. Furthermore, we extend our work to study the effect of cross-phase modulation where an amplifier is seeded with two laser sources.

The conformational flexibility of the carboxy terminal residues 105–114 is a key modulator of the catalytic activity and stability of Macrophage Migration Inhibitory Factor (MIF)†

PubMed Central

El-Turk, Farah; Cascella, Michele; Ouertatani-Sakouhi, Hajer; Narayanan, Raghavendran Lakshmi; Leng, Lin; Bucala, Richard; Hweckstetter, Markus; Rothlisberger, Ursula; Lashuel, Hilal A.

2013-01-01

Macrophage migration inhibitory factor (MIF) is a multifunctional protein and a major mediator of innate immunity. Although X-ray crystallography revealed that MIF exists as a homotrimer, its oligomerization state in vivo as well as the factors governing its oligomerization and stability remain poorly understood. The C-terminal region of MIF is highly conserved and participates in several intramolecular interactions that suggest a role in modulating the stability and biochemical activity of MIF. To determine the importance of these interactions, point mutations (A48P, L46A), insertions (P107) at the monomer-monomer interfaces, and C-terminal deletion (Δ110-114NSTFA and Δ105–114NVGWNNSTFA) variants were designed and their structural properties, thermodynamic stability, oligomerization state, catalytic activity and receptor binding were characterized using a battery of biophysical methods. The C-terminal deletion mutants ΔC5 huMIF1-109 and ΔC10 huMIF1-104 were enzymatically inactive and thermodynamically less stable than wild type MIF. Analytical ultracentrifugation studies demonstrate that both C-terminal mutants sediment as trimers and exhibit similar binding to CD74 as the wild type protein. Disrupting the conformation of the C-terminal region 105–114 and increasing its conformational flexibility through the insertion of a proline residue at position 107 was sufficient to reproduce the structural, biochemical and thermodynamic properties of the deletion mutants. P107 MIF forms an enzymatically inactive trimer and exhibits reduced thermodynamic stability relative to the wild type protein. To provide a rationale for the changes induced by these mutations at the molecular level, we also performed molecular dynamics simulations on these mutants in comparison to the wild type MIF. Together, our studies demonstrate that inter-subunit interactions involving the C-terminal region 105–114, including a salt-bridge interaction between Arg73 of one monomer and the carboxy terminus of a neighbouring monomer, play critical roles in modulating tertiary structure stabilization, enzymatic activity, and thermodynamic stability of MIF, but not its oligomerization state and receptor binding properties. Our results suggest that targeting the C-terminal region could provide new strategies for allosteric modulation of MIF enzymatic activity and the development of novel inhibitors of MIF tautomerase activity. PMID:18795803

LAnd surface remote sensing Products VAlidation System (LAPVAS) and its preliminary application

NASA Astrophysics Data System (ADS)

Lin, Xingwen; Wen, Jianguang; Tang, Yong; Ma, Mingguo; Dou, Baocheng; Wu, Xiaodan; Meng, Lumin

2014-11-01

The long term record of remote sensing product shows the land surface parameters with spatial and temporal change to support regional and global scientific research widely. Remote sensing product with different sensors and different algorithms is necessary to be validated to ensure the high quality remote sensing product. Investigation about the remote sensing product validation shows that it is a complex processing both the quality of in-situ data requirement and method of precision assessment. A comprehensive validation should be needed with long time series and multiple land surface types. So a system named as land surface remote sensing product is designed in this paper to assess the uncertainty information of the remote sensing products based on a amount of in situ data and the validation techniques. The designed validation system platform consists of three parts: Validation databases Precision analysis subsystem, Inter-external interface of system. These three parts are built by some essential service modules, such as Data-Read service modules, Data-Insert service modules, Data-Associated service modules, Precision-Analysis service modules, Scale-Change service modules and so on. To run the validation system platform, users could order these service modules and choreograph them by the user interactive and then compete the validation tasks of remote sensing products (such as LAI ,ALBEDO ,VI etc.) . Taking SOA-based architecture as the framework of this system. The benefit of this architecture is the good service modules which could be independent of any development environment by standards such as the Web-Service Description Language(WSDL). The standard language: C++ and java will used as the primary programming language to create service modules. One of the key land surface parameter, albedo, is selected as an example of the system application. It is illustrated that the LAPVAS has a good performance to implement the land surface remote sensing product validation.

WE-EF-207-09: Single-Scan Dual-Energy CT Using Primary Modulation

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

Petrongolo, M; Zhu, L

Purpose: Compared with conventional CT, dual energy CT (DECT) provides better material differentiation but requires projection data with two different effective x-ray spectra. Current DECT scanners use either a two-scan setting or costly imaging components, which are not feasible or available on open-gantry cone-beam CT systems. We propose a hardware-based method which utilizes primary modulation to enable single-scan DECT on a conventional CT scanner. The CT imaging geometry of primary modulation is identical to that used in our previous method for scatter removal, making it possible for future combination with effective scatter correction on the same CT scanner. Methods: Wemore » insert an attenuation sheet with a spatially-varying pattern - primary modulator-between the x-ray source and the imaged object. During the CT scan, the modulator selectively hardens the x-ray beam at specific detector locations. Thus, the proposed method simultaneously acquires high and low energy data. High and low energy CT images are then reconstructed from projections with missing data via an iterative CT reconstruction algorithm with gradient weighting. Proof-of-concept studies are performed using a copper modulator on a cone-beam CT system. Results: Our preliminary results on the Catphan(c) 600 phantom indicate that the proposed method for single-scan DECT is able to successfully generate high-quality high and low energy CT images and distinguish different materials through basis material decomposition. By applying correction algorithms and using all of the acquired projection data, we can reconstruct a single CT image of comparable image quality to conventional CT images, i.e., without primary modulation. Conclusion: This work shows great promise in using a primary modulator to perform high-quality single-scan DECT imaging. Future studies will test method performance on anthropomorphic phantoms and perform quantitative analyses on image qualities and DECT decomposition accuracy. We will use simulations to optimize the modulator material and geometry parameters.« less

Board-to-board optical interconnection using novel optical plug and slot

NASA Astrophysics Data System (ADS)

Cho, In K.; Yoon, Keun Byoung; Ahn, Seong H.; Kim, Jin Tae; Lee, Woo Jin; Shin, Kyoung Up; Heo, Young Un; Park, Hyo Hoon

2004-10-01

A novel optical PCB with transmitter/receiver system boards and optical bakcplane was prepared, which is board-to-board interconnection by optical plug and slot. We report an 8Gb/s PRBS NRZ data transmission between transmitter system board and optical backplane embedded multimode polymeric waveguide arrays. The basic concept of ETRI's optical PCB is as follows; 1) Metal optical bench is integrated with optoelectronic devices, driver and receiver circuits, polymeric waveguide and access line PCB module. 2) Multimode polymeric waveguide inside an optical backplane, which is embedded into PCB. 3) Optical slot and plug for high-density(channel pitch : 500um) board-to-board interconnection. The polymeric waveguide technology can be used for transmission of data on transmitter/ receiver system boards and for backplane interconnections. The main components are low-loss tapered polymeric waveguides and a novel optical plug and slot for board-to-board interconnections, respectively. The optical PCB is characteristic of low coupling loss, easy insertion/extraction of the boards and, especially, reliable optical coupling unaffected from external environment after board insertion.

Feed-Back Moisture Sensor Control for the Delivery of Water to Plants Cultivated in Space

NASA Technical Reports Server (NTRS)

Levine, Howard G.; Prenger, Jessica J.; Rouzan, Donna T.; Spinale, April C.; Murdoch, Trevor; Burtness, Kevin A.

2005-01-01

The development of a spaceflight-rated Porous Tube Insert Module (PTIM) nutrient delivery tray has facilitated a series of studies evaluating various aspects of water and nutrient delivery to plants as they would be cultivated in space. We report here on our first experiment using the PTIM with a software-driven feedback moisture sensor control strategy for maintaining root zone wetness level set-points. One-day-old wheat seedlings (Tritium aestivum cv Apogee; N=15) were inserted into each of three Substrate Compartments (SCs) pre-packed with 0.25-1 . mm Profile(TradeMark) substrate and maintained at root zone relative water content levels of 70, 80 and 90%. The SCs contained a bottom-situated porous tube around which a capillary mat was wrapped. Three Porous Tubes. were planted using similar protocols (but without the substrate) and also maintained at these three moisture level set-points. Half-strength modified Hoagland's nutrient solution was used to supply water and nutrients. Results on hardware performance, water usage rates and wheat developmental differences between the different experimental treatments are presented.

Genome-wide screening identifies a KCNIP1 copy number variant as a genetic predictor for atrial fibrillation

PubMed Central

Tsai, Chia-Ti; Hsieh, Chia-Shan; Chang, Sheng-Nan; Chuang, Eric Y.; Ueng, Kwo-Chang; Tsai, Chin-Feng; Lin, Tsung-Hsien; Wu, Cho-Kai; Lee, Jen-Kuang; Lin, Lian-Yu; Wang, Yi-Chih; Yu, Chih-Chieh; Lai, Ling-Ping; Tseng, Chuen-Den; Hwang, Juey-Jen; Chiang, Fu-Tien; Lin, Jiunn-Lee

2016-01-01

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Previous genome-wide association studies had identified single-nucleotide polymorphisms in several genomic regions to be associated with AF. In human genome, copy number variations (CNVs) are known to contribute to disease susceptibility. Using a genome-wide multistage approach to identify AF susceptibility CNVs, we here show a common 4,470-bp diallelic CNV in the first intron of potassium interacting channel 1 gene (KCNIP1) is strongly associated with AF in Taiwanese populations (odds ratio=2.27 for insertion allele; P=6.23 × 10−24). KCNIP1 insertion is associated with higher KCNIP1 mRNA expression. KCNIP1-encoded protein potassium interacting channel 1 (KCHIP1) is physically associated with potassium Kv channels and modulates atrial transient outward current in cardiac myocytes. Overexpression of KCNIP1 results in inducible AF in zebrafish. In conclusions, a common CNV in KCNIP1 gene is a genetic predictor of AF risk possibly pointing to a functional pathway. PMID:26831368

Physiological impact of transposable elements encoding DDE transposases in the environmental adaptation of Streptococcus agalactiae.

PubMed

Fléchard, Maud; Gilot, Philippe

2014-07-01

We have referenced and described Streptococcus agalactiae transposable elements encoding DDE transposases. These elements belonged to nine families of insertion sequences (ISs) and to a family of conjugative transposons (TnGBSs). An overview of the physiological impact of the insertion of all these elements is provided. DDE-transposable elements affect S. agalactiae in a number of aspects of its capability to adapt to various environments and modulate the expression of several virulence genes, the scpB-lmB genomic region and the genes involved in capsule expression and haemolysin transport being the targets of several different mobile elements. The referenced mobile elements modify S. agalactiae behaviour by transferring new gene(s) to its genome, by modifying the expression of neighbouring genes at the integration site or by promoting genomic rearrangements. Transposition of some of these elements occurs in vivo, suggesting that by dynamically regulating some adaptation and/or virulence genes, they improve the ability of S. agalactiae to reach different niches within its host and ensure the 'success' of the infectious process. © 2014 The Authors.

Infectious Bovine Viral Diarrhea Virus (Strain NADL) RNA from Stable cDNA Clones: a Cellular Insert Determines NS3 Production and Viral Cytopathogenicity

PubMed Central

Mendez, Ernesto; Ruggli, Nicolas; Collett, Marc S.; Rice, Charles M.

1998-01-01

Bovine viral diarrhea virus (BVDV), strain NADL, was originally isolated from an animal with fatal mucosal disease. This isolate is cytopathic in cell culture and produces two forms of NS3-containing proteins: uncleaved NS2-3 and mature NS3. For BVDV NADL, the production of NS3, a characteristic of cytopathic BVDV strains, is believed to be a consequence of an in-frame insertion of a 270-nucleotide cellular mRNA sequence (called cIns) in the NS2 coding region. In this study, we constructed a stable full-length cDNA copy of BVDV NADL in a low-copy-number plasmid vector. As assayed by transfection of MDBK cells, uncapped RNAs transcribed from this template were highly infectious (>105 PFU/μg). The recovered virus was similar in plaque morphology, growth properties, polyprotein processing, and cytopathogenicity to the BVDV NADL parent. Deletion of cIns abolished processing at the NS2/NS3 site and produced a virus that was no longer cytopathic for MDBK cells. This deletion did not affect the efficiency of infectious virus production or viral protein production, but it reduced the level of virus-specific RNA synthesis and accumulation. Thus, cIns not only modulates NS3 production but also upregulates RNA replication relative to an isogenic noncytopathic derivative lacking the insert. These results raise the possibility of a linkage between enhanced BVDV NADL RNA replication and virus-induced cytopathogenicity. PMID:9573238

High Piezoelectric Conversion Properties of Axial InGaN/GaN Nanowires.

PubMed

Jegenyes, Nikoletta; Morassi, Martina; Chrétien, Pascal; Travers, Laurent; Lu, Lu; Julien, Francois H; Tchernycheva, Maria; Houzé, Frédéric; Gogneau, Noelle

2018-05-25

We demonstrate for the first time the efficient mechanical-electrical conversion properties of InGaN/GaN nanowires (NWs). Using an atomic force microscope equipped with a modified Resiscope module, we analyse the piezoelectric energy generation of GaN NWs and demonstrate an important enhancement when integrating in their volume a thick In-rich InGaN insertion. The piezoelectric response of InGaN/GaN NWs can be tuned as a function of the InGaN insertion thickness and position in the NW volume. The energy harvesting is favoured by the presence of a PtSi/GaN Schottky diode which allows to efficiently collect the piezo-charges generated by InGaN/GaN NWs. Average output voltages up to 330 ± 70 mV and a maximum value of 470 mV per NW has been measured for nanostructures integrating 70 nm-thick InGaN insertion capped with a thin GaN top layer. This latter value establishes an increase of about 35% of the piezo-conversion capacity in comparison with binary p-doped GaN NWs. Based on the measured output signals, we estimate that one layer of dense InGaN/GaN-based NW can generate a maximum output power density of about 3.3 W/cm². These results settle the new state-of-the-art for piezo-generation from GaN-based NWs and offer a promising perspective for extending the performances of the piezoelectric sources.

Elaboration and Evaluation of Contents about Hearing Health Inserted in Cybertutor.

PubMed

Corrêa, Camila de Castro; Silva, Ricelly Avila da; Blasca, Wanderléia Quinhoneiro

2014-04-01

Introduction Cybertutor (electronic tutor) is a type of information and communication technology to disseminate knowledge about hearing, aiming at the prevention of hearing alterations and, when needed, early treatment, in addition to social inclusion of the hearing impaired. However, it is important to evaluate the level of language used in the content and the subjective perception of the target public regarding improvements of the tool. Objective To improve content about hearing health inserted in a cybertutor and to evaluate the level of legibility and the quality of the content and material made available. Method For the construction of the content, text and audiovisual resources were used, based on scientific publications, and were evaluated objectively with Flesch Reading Ease test and subjectively with a questionnaire created by the authors and answered by 10 ninth-year pupils. Results Two modules on hearing health were created, "Hearing Health" and "Intervention and Rehabilitation," which received Flesch scores of 50.8 and 51.4%, respectively, making it necessary to have a sixth- to ninth-year education to understand the material. The students' evaluation in reference to language and material showed that 55.5% considered the contents excellent; 38.2% classified the contents as satisfactory; 6.3% considered them reasonable; and 0% classified them as unsatisfactory. Conclusion The contents inserted in the cybertutor about hearing health presented a language level considered easy for the age group of the target population, in addition to receiving good subjective evaluation from the pupils, facilitating access to the information.

Stand-alone development system using a KIM-1 microcomputer module

NASA Technical Reports Server (NTRS)

Nickum, J. D.

1978-01-01

A small microprocessor-based system designed to: contain all or most of the interface hardware, designed to be easy to access and modify the hardware, to be capable of being strapped to the seat of a small general aviation aircraft, and to be independent of the aircraft power system is described. The system is used to develop a low cost Loran C sensor processor, but is designed such that the Loran interface boards may be removed and other hardware interfaces inserted into the same connectors. This flexibility is achieved through memory-mapping techniques into the microprocessor.

Breathing of Graphite Particles in a Lithium-Ion Battery

NASA Astrophysics Data System (ADS)

Takata, Keiji; Okuda, Mitsuhiro; Yura, Nobuki; Tamura, Ryota

2012-04-01

We imaged changes in volume of graphite particles in a Li-ion battery due to the insertion and extraction of Li ions using scanning probe microscopy. When Li ions were extracted from the graphite particles, the particles were contracted, while expansion was induced in the interspaces between the particles. Variations of the images of volume changes depending on modulation frequencies clearly showed lithium intercalation. A linear relationship between the amplitudes of volume changes and the products of the diffusion elements and the reciprocals of the frequencies has been proven. Thus, the detected signals quantitatively well corresponded to the lithium ion movements.

Solar Mesosphere Explorer

NASA Technical Reports Server (NTRS)

1981-01-01

Five experiments and the instruments packages designed for use in studying reactions between sunlight, ozone, and other chemicals in the atmosphere as well as for determining how ozone concentrations are transported in the mesosphere are described. The spin-stabilized satellite carrying the experiments consists of an observatory module and a spacecraft bus. Powered by a solar array which charges the nickel-cadmium batteries, the satellite is to be inserted into a sun synchronous orbit by a two stage Delta 2310 launch vehicle. The mission objectives, spacecraft configurations, and various subsystems are described as well as the ground support and prelaunch operations.

Electro-Optic Effect in Thin Films of a Dielectric and a Ferroelectric with Subwavelength Aluminum Grating

NASA Astrophysics Data System (ADS)

Blinov, L. M.; Lazarev, V. V.; Yudin, S. G.; Artemov, V. V.; Palto, S. P.; Gorkunov, M. V.

2018-01-01

The electro-optic effect in three nanoscale heterostructures, in each of which a thin layer of dielectric or ferroelectric material is inserted between two planar metal electrodes, has been studied. Each structure has one aluminum layer, containing a subwavelength grating with a period of 400 nm, contacting with either the glass substrate or air. The light transmission spectra of structures with subwavelength grating contain characteristic plasmon dips. Short external-voltage pulses affect the change in the refractive index of the corresponding active layer. Significant values of these changes may be useful for designing optical modulators.

ITER Central Solenoid Module Fabrication

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

Smith, John

The fabrication of the modules for the ITER Central Solenoid (CS) has started in a dedicated production facility located in Poway, California, USA. The necessary tools have been designed, built, installed, and tested in the facility to enable the start of production. The current schedule has first module fabrication completed in 2017, followed by testing and subsequent shipment to ITER. The Central Solenoid is a key component of the ITER tokamak providing the inductive voltage to initiate and sustain the plasma current and to position and shape the plasma. The design of the CS has been a collaborative effort betweenmore » the US ITER Project Office (US ITER), the international ITER Organization (IO) and General Atomics (GA). GA’s responsibility includes: completing the fabrication design, developing and qualifying the fabrication processes and tools, and then completing the fabrication of the seven 110 tonne CS modules. The modules will be shipped separately to the ITER site, and then stacked and aligned in the Assembly Hall prior to insertion in the core of the ITER tokamak. A dedicated facility in Poway, California, USA has been established by GA to complete the fabrication of the seven modules. Infrastructure improvements included thick reinforced concrete floors, a diesel generator for backup power, along with, cranes for moving the tooling within the facility. The fabrication process for a single module requires approximately 22 months followed by five months of testing, which includes preliminary electrical testing followed by high current (48.5 kA) tests at 4.7K. The production of the seven modules is completed in a parallel fashion through ten process stations. The process stations have been designed and built with most stations having completed testing and qualification for carrying out the required fabrication processes. The final qualification step for each process station is achieved by the successful production of a prototype coil. Fabrication of the first ITER module is in progress. The seven modules will be individually shipped to Cadarache, France upon their completion. This paper describes the processes and status of the fabrication of the CS Modules for ITER.« less

Collimator design for a multipinhole brain SPECT insert for MRI

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

Van Audenhaege, Karen; Van Holen, Roel; Vanhove, Christian

Purpose: Brain single photon emission computed tomography (SPECT) imaging is an important clinical tool, with unique tracers for studying neurological diseases. Nowadays, most commercial SPECT systems are combined with x-ray computed tomography (CT) in so-called SPECT/CT systems to obtain an anatomical background for the functional information. However, while CT images have a high spatial resolution, they have a low soft-tissue contrast, which is an important disadvantage for brain imaging. Magnetic resonance imaging (MRI), on the other hand, has a very high soft-tissue contrast and does not involve extra ionizing radiation. Therefore, the authors designed a brain SPECT insert that canmore » operate inside a clinical MRI. Methods: The authors designed and simulated a compact stationary multipinhole SPECT insert based on digital silicon photomultiplier detector modules, which have shown to be MR-compatible and have an excellent intrinsic resolution (0.5 mm) when combined with a monolithic 2 mm thick LYSO crystal. First, the authors optimized the different parameters of the SPECT system to maximize sensitivity for a given target resolution of 7.2 mm in the center of the field-of-view, given the spatial constraints of the MR system. Second, the authors performed noiseless simulations of two multipinhole configurations to evaluate sampling and reconstructed resolution. Finally, the authors performed Monte Carlo simulations and compared the SPECT insert with a clinical system with ultrahigh-resolution (UHR) fan beam collimators, based on contrast-to-noise ratio and a visual comparison of a Hoffman phantom with a 9 mm cold lesion. Results: The optimization resulted in a stationary multipinhole system with a collimator radius of 150.2 mm and a detector radius of 172.67 mm, which corresponds to four rings of 34 diSPM detector modules. This allows the authors to include eight rings of 24 pinholes, which results in a system volume sensitivity of 395 cps/MBq. Noiseless simulations show sufficient axial sampling (in a Defrise phantom) and a reconstructed resolution of 5.0 mm (in a cold-rod phantom). The authors compared the 24-pinhole setup with a 34-pinhole system (with the same detector radius but a collimator radius of 156.63 mm) and found that 34 pinholes result in better uniformity but a worse reconstruction of the cold-rod phantom. The authors also compared the 24-pinhole system with a clinical triple-head UHR fan beam system based on contrast-to-noise ratio and found that the 24-pinhole setup performs better for the 6 mm hot and the 16 mm cold lesions and worse for the 8 and 10 mm hot lesions. Finally, the authors reconstructed noisy projection data of a Hoffman phantom with a 9 mm cold lesion and found that the lesion was slightly better visible on the multipinhole image compared to the fan beam image. Conclusions: The authors have optimized a stationary multipinhole SPECT insert for MRI and showed the feasibility of doing brain SPECT imaging inside a MRI with an image quality similar to the best clinical SPECT systems available.« less

Ultra-large optical modulation of electrochromic porous WO3 film and the local monitoring of redox activity† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c5sc03727a

PubMed Central

Cai, Guofa; Cui, Mengqi; Kumar, Vipin; Darmawan, Peter; Wang, Jiangxin; Wang, Xu; Lee-Sie Eh, Alice; Qian, Kai

2016-01-01

Porous WO3 films with ultra-high transmittance modulation were successfully fabricated on different substrates by a novel, facile and economical pulsed electrochemical deposited method with 1.1 s interval time between each pulse. The near ideal optical modulation (97.7% at 633 nm), fast switching speed (6 and 2.7 s), high coloration efficiency (118.3 cm2 C–1), and excellent cycling stability are achieved by the porous WO3 on ITO-coated glass. The outstanding electrochromic performances of the porous WO3 film were mainly attributed to the porous structure, which facilitates the charge-transfer, promotes the electrolyte infiltration and alleviates the expansion of the WO3 during H+ insertion compared to that of the compact structure. In addition, the relationships between the structural and electrochemical activity of the electrochromic WO3 films were further explored by the scanning electrochemical microscopy. These results testify that the porous structure can promote the infiltration of electrolyte and reduce the diffusion path, which consequently enhance the electrochemical activity. PMID:29910894

Utility of coupling nonlinear optimization methods with numerical modeling software

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

Murphy, M.J.

1996-08-05

Results of using GLO (Global Local Optimizer), a general purpose nonlinear optimization software package for investigating multi-parameter problems in science and engineering is discussed. The package consists of the modular optimization control system (GLO), a graphical user interface (GLO-GUI), a pre-processor (GLO-PUT), a post-processor (GLO-GET), and nonlinear optimization software modules, GLOBAL & LOCAL. GLO is designed for controlling and easy coupling to any scientific software application. GLO runs the optimization module and scientific software application in an iterative loop. At each iteration, the optimization module defines new values for the set of parameters being optimized. GLO-PUT inserts the new parametermore » values into the input file of the scientific application. GLO runs the application with the new parameter values. GLO-GET determines the value of the objective function by extracting the results of the analysis and comparing to the desired result. GLO continues to run the scientific application over and over until it finds the ``best`` set of parameters by minimizing (or maximizing) the objective function. An example problem showing the optimization of material model is presented (Taylor cylinder impact test).« less

Backplane photonic interconnect modules with optical jumpers

NASA Astrophysics Data System (ADS)

Glebov, Alexei L.; Lee, Michael G.; Yokouchi, Kishio

2005-03-01

Prototypes of optical interconnect (OI) modules for backplane applications are presented. The transceivers attached to the linecards E/O convert the signals that are passed to and from the backplane by optical jumpers terminated with MTP-type connectors. The connectors plug into adaptors attached to the backplane and the microlens arrays mounted in the adaptors couple the light between the fibers and waveguides. Planar polymer channel waveguides with 30-50 μm cross-sections route the optical signals across the board with propagation losses as low as 0.05 dB/cm @ 850 nm. The 45¦-tapered integrated micromirrors reflect the light in and out of the waveguide plane with the loss of 0.8 dB per mirror. The connector displacement measurements indicate that the adaptor lateral assembly accuracy can be at least +/-10 μm for the excess loss not exceeding 1 dB. Insertion losses of the test modules with integrated waveguides, 45¦ mirrors, and pluggable optical jumper connectors are about 5 dB. Eye diagrams at 10.7 Gb/s have typical width and height of 70 ps and 400 mV, respectively, and jitter of about 20 ps.

Urethra sparing - potential of combined Nickel-Titanium stent and intensity modulated radiation therapy in prostate cancer.

PubMed

Thomsen, Jakob Borup; Arp, Dennis Tideman; Carl, Jesper

2012-05-01

To investigate a novel method for sparing urethra in external beam radiotherapy of prostate cancer and to evaluate the efficacy of such a treatment in terms of tumour control using a mathematical model. This theoretical study includes 20 patients previously treated for prostate cancer using external beam radiotherapy. All patients had a Nickel-Titanium (Ni-Ti) stent inserted into the prostate part of urethra. The stent has been used during the treatment course as an internal marker for patient positioning prior to treatment. In this study the stent is used for delineating urethra while intensity modulated radiotherapy was used for lowering dose to urethra. Evaluation of the dose plans were performed using a tumour control probability model based on the concept of uniform equivalent dose. The feasibility of the urethra dose reduction method is validated and a reduction of about 17% is shown to be possible. Calculations suggest a nearly preserved tumour control probability. A new concept for urethra dose reduction is presented. The method relies on the use of a Ni-Ti stent as a fiducial marker combined with intensity modulated radiotherapy. Theoretical calculations suggest preserved tumour control. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Terahertz Modulator based on Metamaterials integrated with Metal-Semiconductor-Metal Varactors

PubMed Central

Nouman, Muhammad Tayyab; Kim, Hyun-Woong; Woo, Jeong Min; Hwang, Ji Hyun; Kim, Dongju; Jang, Jae-Hyung

2016-01-01

The terahertz (THz) band of the electromagnetic spectrum, with frequencies ranging from 300 GHz to 3 THz, has attracted wide interest in recent years owing to its potential applications in numerous areas. Significant progress has been made toward the development of devices capable of actively controlling terahertz waves; nonetheless, further advances in device functionality are necessary for employment of these devices in practical terahertz systems. Here, we demonstrate a low voltage, sharp switching terahertz modulator device based on metamaterials integrated with metal semiconductor metal (MSM) varactors, fabricated on an AlGaAs/InGaAs based heterostructure. By varying the applied voltage to the MSM-varactor located at the center of split ring resonator (SRR), the resonance frequency of the SRR-based metamaterial is altered. Upon varying the bias voltage from 0 V to 3 V, the resonance frequency exhibits a transition from 0.52 THz to 0.56 THz, resulting in a modulation depth of 45 percent with an insertion loss of 4.3 dB at 0.58 THz. This work demonstrates a new approach for realizing active terahertz devices with improved functionalities. PMID:27194128

Chimeric Cellulase Matrix for Investigating Intramolecular Synergism between Non-hydrolytic Disruptive Functions of Carbohydrate-binding Modules and Catalytic Hydrolysis*

PubMed Central

Wang, Yuguo; Tang, Rentao; Tao, Jin; Wang, Xiaonan; Zheng, Baisong; Feng, Yan

2012-01-01

The conversion of renewable cellulosic biomass is of considerable interest for the production of biofuels and materials. The bottleneck in the efficient conversion is the compactness and resistance of crystalline cellulose. Carbohydrate-binding modules (CBMs), which disrupt crystalline cellulose via non-hydrolytic mechanisms, are expected to overcome this bottleneck. However, the lack of convenient methods for quantitative analysis of the disruptive functions of CBMs have hindered systematic studies and molecular modifications. Here we established a practical and systematic platform for quantifying and comparing the non-hydrolytic disruptive activities of CBMs via the synergism of CBMs and a catalytic module within designed chimeric cellulase molecules. Bioinformatics and computational biology were also used to provide a deeper understanding. A convenient vector was constructed to serve as a cellulase matrix into which heterologous CBM sequences can be easily inserted. The resulting chimeric cellulases were suitable for studying disruptive functions, and their activities quantitatively reflected the disruptive functions of CBMs on crystalline cellulose. In addition, this cellulase matrix can be used to construct novel chimeric cellulases with high hydrolytic activities toward crystalline cellulose. PMID:22778256

Research of beam smoothing technology on the technical integration line

NASA Astrophysics Data System (ADS)

Zhang, Rui; Su, Jingqin; Li, Ping; Zhang, Ying; Wang, Jianjun; Dong, Jun; Yang, Dong; Jing, Feng; Xu, Lixin; Ming, Hai

2013-05-01

This paper is focused on the research of SSD and CPP carried out on TIL. A bulk phase modulator with 9.2-GHz modulation frequency is adopted in SSD. The output spectrum of the phase modulator is stable and the residual amplitude modulation is small. FM-to-AM effect caused by free-space propagation after using smoothing by spectral dispersion is theoretically and experimentally studied. Results indicate inserting a dispersion grating in places with larger beam aperture alleviates the FM-to-AM effect, suggesting minimizing free-space propagation and adopting image relay. Experiments indicate when the number of color cycles (Nc) adopts 1, imposing of SSD with 4.26 times diffraction limit (TDL) did not lead to pinhole closure in the spatial filters of the preamplifier with 20 TDL and main amplifier with 26 TDL. Experimental results also indicate SSD didn't influence the load capacity of the laser facility. The contrast of the 440-μm diameter focal spot with 95% energy included using SSD and CPP drops to 0.47, comparing to 1.71 not using SSD and CPP. When the pulse width of the third harmonic wave is 1 ns and the energy is 1115 J, no damage is found in CPP and other final optics. The experiments solves some key technical problems using SSD and CPP on high-power laser facilities, and provides a flexible platform for the laser-plasma interaction experiments.

Evidence for Induction of Integron-Based Antibiotic Resistance by the SOS Response in a Clinical Setting

PubMed Central

Hocquet, Didier; Llanes, Catherine; Thouverez, Michelle; Kulasekara, Hemantha D.; Bertrand, Xavier; Plésiat, Patrick; Mazel, Didier; Miller, Samuel I.

2012-01-01

Bacterial resistance to β-lactams may rely on acquired β-lactamases encoded by class 1 integron-borne genes. Rearrangement of integron cassette arrays is mediated by the integrase IntI1. It has been previously established that integrase expression can be activated by the SOS response in vitro, leading to speculation that this is an important clinical mechanism of acquiring resistance. Here we report the first in vivo evidence of the impact of SOS response activated by the antibiotic treatment given to a patient and its output in terms of resistance development. We identified a new mechanism of modulation of antibiotic resistance in integrons, based on the insertion of a genetic element, the gcuF1 cassette, upstream of the integron-borne cassette bla OXA-28 encoding an extended spectrum β-lactamase. This insertion creates the fused protein GCUF1-OXA-28 and modulates the transcription, the translation, and the secretion of the β-lactamase in a Pseudomonas aeruginosa isolate (S-Pae) susceptible to the third generation cephalosporin ceftazidime. We found that the metronidazole, not an anti-pseudomonal antibiotic given to the first patient infected with S-Pae, triggered the SOS response that subsequently activated the integrase IntI1 expression. This resulted in the rearrangement of the integron gene cassette array, through excision of the gcuF1 cassette, and the full expression the β-lactamase in an isolate (R-Pae) highly resistant to ceftazidime, which further spread to other patients within our hospital. Our results demonstrate that in human hosts, the antibiotic-induced SOS response in pathogens could play a pivotal role in adaptation process of the bacteria. PMID:22719259

Centrally administered verapamil prevents the autonomic reaction to visceral pain in sheep.

PubMed

Kania, B F; Brytan, M; Tomaszewska, D

2009-02-01

The significant role of voltage gated calcium channels (VGCC) L-type antagonists used concomitantly with opioids in attenuation of clinical pain has been confirmed. The aim of this study was to evaluate the effect of centrally administered verapamil on behavior and biochemical parameters in sheep that have undergone experimental duodenal distension (DD) and to determine whether verapamil exerts any anti-nociceptive effects under these conditions. The study was carried out using 24 mature crossbred ewes, each weighing 38-43 kg. Verapamil, a VGCC blocker, was administered through an intracerebroventricular cannula at the following doses: 0.25, 0.5, 1.0 and 2.0mg in toto. Ten minutes later experimental DD was conducted by insertion and the distension of rubber balloon (containing 40 ml of warm water) inserted into sheep duodenum. After 5 min of mechanical DD the following reactions were then observed: the significant increase in behavioral pain responses, i.e. tachycardia, hyperventilation, inhibition of reticulo-ruminal contractions (70% approximately, during 15 min), an increase of plasma catecholamine concentration (over 7-fold increase of epinephrine during 2h following DD, 2-times norepinephrine and +/-80% increase of dopamine). Verapamil infusion administered 10 min prior to DD decreased intensity of visceral pain responses, such as: behavioral changes, tachycardia, hyperventilation, inhibition of the reticulo-rumen motility and efficiently prevented the appearance of catecholamine release. These data demonstrated that the development and persistence of duodenal hyperalgesia depends on the activation of Ca(2+) ion flux leading to neurotransmitters release and modulation of membrane excitability. The observed antinociceptive action of VGCCs type-L blockers suggests that these channels play a crucial role in the modulation of acute visceral hyperalgesia in sheep.

Modulation of epithelial sodium channel trafficking and function by sodium 4-phenylbutyrate in human nasal epithelial cells.

PubMed

Prulière-Escabasse, Virginie; Planès, Carole; Escudier, Estelle; Fanen, Pascale; Coste, André; Clerici, Christine

2007-11-23

Sodium 4-phenylbutyrate (4-PBA) has been shown to correct the cellular trafficking of several mutant or nonmutant plasma membrane proteins such as cystic fibrosis transmembrane conductance regulator through the expression of 70-kDa heat shock proteins. The objective of the study was to determine whether 4-PBA may influence the functional expression of epithelial sodium channels (ENaC) in human nasal epithelial cells (HNEC). Using primary cultures of HNEC, we demonstrate that 4-PBA (5 mm for 6 h) markedly stimulated amiloride-sensitive sodium channel activity and that this was related to an increased abundance of alpha-, beta-, and gamma-ENaC subunits in the apical membrane. The increase in ENaC cell surface expression (i) was due to insertion of newly ENaC subunits as determined by brefeldin A experiments and (ii) was not associated with cell surface retention of ENaC subunits because endocytosis of ENaC subunits was unchanged. In addition, we find that ENaC co-immunoprecipitated with the heat shock protein constitutively expressed Hsc70, that has been reported to modulate ENaC trafficking, and that 4-PBA decreased Hsc70 protein level. Finally, we report that in cystic fibrosis HNEC obtained from two cystic fibrosis patients, 4-PBA increased functional expression of ENaC as demonstrated by the increase in amiloride-sensitive sodium transport and in alpha-, beta-, and gamma-ENaC subunit expression in the apical membrane. Our results suggest that in HNEC, 4-PBA increases the functional expression of ENaC through the insertion of new alpha-, beta-, and gamma-ENaC subunits into the apical membrane and also suggest that 4-PBA could modify ENaC trafficking by reducing Hsc70 protein expression.

Co-expression network analysis of duplicate genes in maize (Zea mays L.) reveals no subgenome bias.

PubMed

Li, Lin; Briskine, Roman; Schaefer, Robert; Schnable, Patrick S; Myers, Chad L; Flagel, Lex E; Springer, Nathan M; Muehlbauer, Gary J

2016-11-04

Gene duplication is prevalent in many species and can result in coding and regulatory divergence. Gene duplications can be classified as whole genome duplication (WGD), tandem and inserted (non-syntenic). In maize, WGD resulted in the subgenomes maize1 and maize2, of which maize1 is considered the dominant subgenome. However, the landscape of co-expression network divergence of duplicate genes in maize is still largely uncharacterized. To address the consequence of gene duplication on co-expression network divergence, we developed a gene co-expression network from RNA-seq data derived from 64 different tissues/stages of the maize reference inbred-B73. WGD, tandem and inserted gene duplications exhibited distinct regulatory divergence. Inserted duplicate genes were more likely to be singletons in the co-expression networks, while WGD duplicate genes were likely to be co-expressed with other genes. Tandem duplicate genes were enriched in the co-expression pattern where co-expressed genes were nearly identical for the duplicates in the network. Older gene duplications exhibit more extensive co-expression variation than younger duplications. Overall, non-syntenic genes primarily from inserted duplications show more co-expression divergence. Also, such enlarged co-expression divergence is significantly related to duplication age. Moreover, subgenome dominance was not observed in the co-expression networks - maize1 and maize2 exhibit similar levels of intra subgenome correlations. Intriguingly, the level of inter subgenome co-expression was similar to the level of intra subgenome correlations, and genes from specific subgenomes were not likely to be the enriched in co-expression network modules and the hub genes were not predominantly from any specific subgenomes in maize. Our work provides a comprehensive analysis of maize co-expression network divergence for three different types of gene duplications and identifies potential relationships between duplication types, duplication ages and co-expression consequences.

Evolution and Diversity of the Antimicrobial Resistance Associated Mobilome in Streptococcus suis: A Probable Mobile Genetic Elements Reservoir for Other Streptococci.

PubMed

Huang, Jinhu; Ma, Jiale; Shang, Kexin; Hu, Xiao; Liang, Yuan; Li, Daiwei; Wu, Zuowei; Dai, Lei; Chen, Li; Wang, Liping

2016-01-01

Streptococcus suis is a previously neglected, newly emerging multidrug-resistant zoonotic pathogen. Mobile genetic elements (MGEs) play a key role in intra- and interspecies horizontal transfer of antimicrobial resistance (AMR) determinants. Although, previous studies showed the presence of several MGEs, a comprehensive analysis of AMR-associated mobilome as well as their interaction and evolution has not been performed. In this study, we presented the AMR-associated mobilome and their insertion hotspots in S. suis . Integrative conjugative elements (ICEs), prophages and tandem MGEs were located at different insertion sites, while 86% of the AMR-associated MGEs were inserted at rplL and rum loci. Comprehensive analysis of insertions at rplL and rum loci among four pathogenic Streptococcus species ( Streptococcus agalactiae, Streptococcus pneumoniae, Streptococcus pyogenes , and S. suis ) revealed the existence of different groups of MGEs, including Tn5252, ICE Sp 1108, and TnGBS2 groups ICEs, Φm46.1 group prophage, ICE_ICE and ICE_prophage tandem MGEs. Comparative ICE genomics of ICE Sa 2603 family revealed that module exchange and acquisition/deletion were the main mechanisms in MGEs' expansion and evolution. Furthermore, the observation of tandem MGEs reflected a novel mechanism for MGE diversity. Moreover, an in vitro competition assay showed no visible fitness cost was observed between different MGE-carrying isolates and a conjugation assay revealed the transferability of ICE Sa 2603 family of ICEs. Our statistics further indicated that the prevalence and diversity of MGEs in S. suis is much greater than in other three species which prompted our hypothesis that S. suis is probably a MGEs reservoir for other streptococci. In conclusion, our results showed that acquisition of MGEs confers S. suis not only its capability as a multidrug resistance pathogen, but also represents a paradigm to study the modular evolution and matryoshkas of MGEs.

Evolution and Diversity of the Antimicrobial Resistance Associated Mobilome in Streptococcus suis: A Probable Mobile Genetic Elements Reservoir for Other Streptococci

PubMed Central

Huang, Jinhu; Ma, Jiale; Shang, Kexin; Hu, Xiao; Liang, Yuan; Li, Daiwei; Wu, Zuowei; Dai, Lei; Chen, Li; Wang, Liping

2016-01-01

Streptococcus suis is a previously neglected, newly emerging multidrug-resistant zoonotic pathogen. Mobile genetic elements (MGEs) play a key role in intra- and interspecies horizontal transfer of antimicrobial resistance (AMR) determinants. Although, previous studies showed the presence of several MGEs, a comprehensive analysis of AMR-associated mobilome as well as their interaction and evolution has not been performed. In this study, we presented the AMR-associated mobilome and their insertion hotspots in S. suis. Integrative conjugative elements (ICEs), prophages and tandem MGEs were located at different insertion sites, while 86% of the AMR-associated MGEs were inserted at rplL and rum loci. Comprehensive analysis of insertions at rplL and rum loci among four pathogenic Streptococcus species (Streptococcus agalactiae, Streptococcus pneumoniae, Streptococcus pyogenes, and S. suis) revealed the existence of different groups of MGEs, including Tn5252, ICESp1108, and TnGBS2 groups ICEs, Φm46.1 group prophage, ICE_ICE and ICE_prophage tandem MGEs. Comparative ICE genomics of ICESa2603 family revealed that module exchange and acquisition/deletion were the main mechanisms in MGEs' expansion and evolution. Furthermore, the observation of tandem MGEs reflected a novel mechanism for MGE diversity. Moreover, an in vitro competition assay showed no visible fitness cost was observed between different MGE-carrying isolates and a conjugation assay revealed the transferability of ICESa2603 family of ICEs. Our statistics further indicated that the prevalence and diversity of MGEs in S. suis is much greater than in other three species which prompted our hypothesis that S. suis is probably a MGEs reservoir for other streptococci. In conclusion, our results showed that acquisition of MGEs confers S. suis not only its capability as a multidrug resistance pathogen, but also represents a paradigm to study the modular evolution and matryoshkas of MGEs. PMID:27774436

Validation of measurement‐guided 3D VMAT dose reconstruction on a heterogeneous anthropomorphic phantom

PubMed Central

Opp, Daniel; Nelms, Benjamin E.; Zhang, Geoffrey; Stevens, Craig

2013-01-01

3DVH software (Sun Nuclear Corp., Melbourne, FL) is capable of generating a volumetric patient VMAT dose by applying a volumetric perturbation algorithm based on comparing measurement‐guided dose reconstruction and TPS‐calculated dose to a cylindrical phantom. The primary purpose of this paper is to validate this dose reconstruction on an anthropomorphic heterogeneous thoracic phantom by direct comparison to independent measurements. The dosimetric insert to the phantom is novel, and thus the secondary goal is to demonstrate how it can be used for the hidden target end‐to‐end testing of VMAT treatments in lung. A dosimetric insert contains a 4 cm diameter unit‐density spherical target located inside the right lung (0.21g/cm3 density). It has 26 slots arranged in two orthogonal directions, milled to hold optically stimulated luminescent dosimeters (OSLDs). Dose profiles in three cardinal orthogonal directions were obtained for five VMAT plans with varying degrees of modulation. After appropriate OSLD corrections were applied, 3DVH measurement‐guided VMAT dose reconstruction agreed 100% with the measurements in the unit density target sphere at 3%/3 mm level (composite analysis) for all profile points for the four less‐modulated VMAT plans, and for 96% of the points in the highly modulated C‐shape plan (from TG‐119). For this latter plan, while 3DVH shows acceptable agreement with independent measurements in the unit density target, in the lung disagreement with experiment is relatively high for both the TPS calculation and 3DVH reconstruction. For the four plans excluding the C‐shape, 3%/3mm overall composite analysis passing rates for 3DVH against independent measurement ranged from 93% to 100%. The C‐shape plan was deliberately chosen as a stress test of the algorithm. The dosimetric spatial alignment hidden target test demonstrated the average distance to agreement between the measured and TPS profiles in the steep dose gradient area at the edge of the 2 cm target to be 1.0±0.7,0.3±0.3, and 0.3±0.3mm for the IEC X, Y, and Z directions, respectively. PACS number: 87.55Qr PMID:23835381

Metal-capped silicon organic micro-ring electro-optical modulator (Conference Presentation)

NASA Astrophysics Data System (ADS)

Zaki, Aya O.; Kirah, Khaled A.; Swillam, Mohamed A.

2017-02-01

An ultra-compact hybrid plasmonic waveguide ring electro-optical modulator is designed to be easily fabricated on silicon on insulator (SOI) substrates using standard silicon photonics technology. The proposed waveguide is based on a buried standard silicon waveguide of height 220 nm topped with polymer and metal. The key advantage of this novel design is that only the silicon layer of the waveguide is structured as a coupled ring resonator. Then, the device is covered with electro-optical polymer and metal in post processes with no need for lithography or accurate mask alignment techniques. The simple fabrication method imposes many design challenges to obtain a resonator of reasonable loaded quality factor and high extinction ratio. Here, the performance of the resonator is optimized in the telecom wavelength range around 1550 nm using 3D FDTD simulations. The design of the coupling junction between the access waveguide and the tightly bent ring is thoroughly studied. The extension of the metal over the coupling region is exploited to make the critical dimension of the design geometry at least 2.5 times larger than conventional plasmonic resonators and the design is thus more robust. In this paper, we demonstrate an electro-optical modulator that offers an insertion loss < 1 dB, a modulation depth of 12 dB for an applied peak to peak voltage of only 2 V and energy consumption of 1.74 fJ/bit. The performance is superior to previously reported hybrid plasmonic ring resonator based modulators while the design shows robustness and low fabrication cost.

Effects of nanomaterial saturable absorption on gain-guide soliton in a positive group-dispersion fiber laser: Simulations and experiments

NASA Astrophysics Data System (ADS)

Du, Tuanjie; Wan, Xiaojiao; Yang, Runhua; Li, Weiwei; Ruan, Qiujun; Chen, Nan; Luo, Zhengqian

2018-01-01

In recent years, several kinds of nanomaterials have been discovered, and successfully used as saturable absorbers (SAs) for passively mode-locked fiber lasers. However, it is found that most of nanomaterials-based SAs cannot stably generate gain-guide solitons in positive group-dispersion fiber lasers, which is urgently expected to fully understand the inherent reasons. In this paper, we numerically and experimentally investigate the effects of nanomaterial saturable absorption (e.g. modulation depth and saturation optical power) on gain-guide soliton in positive group-dispersion Er3+-doped fiber laser (PGD-EDFL). By numerically solving the Ginzburg-Landau equation, the evolutions of both the mode-locked optical spectrum and pulse duration as a function of modulation depth and saturation optical power are analyzed, respectively. In experiment, we firstly prepare five nanomaterial SAs with the similar insertion loss, which have the different modulation depth from 1.80% to 23.36%, and the different saturation optical power from 8.8 to 536 W. We then perform the experimental comparison by incorporating the five SAs in a same PGD-EDFL cavity, respectively. The experimental results are in good agreement with the numerical ones. Our result reveals that: (1) a low modulation depth cannot support the formation of gain-guide soliton, (2) as the modulation depth increases, the spectral bandwidth of gain-guide soliton increases, the pulse duration decreases and the pulse chirp becomes large, (3) the saturation optical power has the weak influences on the gain-guide soliton performances.

Remote down-hole well telemetry

DOEpatents

Briles, Scott D [Los Alamos, NM; Neagley, Daniel L [Albuquerque, NM; Coates, Don M [Santa Fe, NM; Freund, Samuel M [Los Alamos, NM

2004-07-20

The present invention includes an apparatus and method for telemetry communication with oil-well monitoring and recording instruments located in the vicinity of the bottom of gas or oil recovery pipes. Such instruments are currently monitored using electrical cabling that is inserted into the pipes; cabling has a short life in this environment, and requires periodic replacement with the concomitant, costly shutdown of the well. Modulated reflectance, a wireless communication method that does not require signal transmission power from the telemetry package will provide a long-lived and reliable way to monitor down-hole conditions. Normal wireless technology is not practical since batteries and capacitors have to frequently be replaced or recharged, again with the well being removed from service. RF energy generated above ground can also be received, converted and stored down-hole without the use of wires, for actuating down-hole valves, as one example. Although modulated reflectance reduces or eliminates the loss of energy at the sensor package because energy is not consumed, during the transmission process, additional stored extra energy down-hole is needed.

SAP97-mediated ADAM10 trafficking from Golgi outposts depends on PKC phosphorylation

PubMed Central

Saraceno, C; Marcello, E; Di Marino, D; Borroni, B; Claeysen, S; Perroy, J; Padovani, A; Tramontano, A; Gardoni, F; Di Luca, M

2014-01-01

A disintegrin and metalloproteinase 10 (ADAM10) is the major α-secretase that catalyzes the amyloid precursor protein (APP) ectodomain shedding in the brain and prevents amyloid formation. Its activity depends on correct intracellular trafficking and on synaptic membrane insertion. Here, we describe that in hippocampal neurons the synapse-associated protein-97 (SAP97), an excitatory synapse scaffolding element, governs ADAM10 trafficking from dendritic Golgi outposts to synaptic membranes. This process is mediated by a previously uncharacterized protein kinase C phosphosite in SAP97 SRC homology 3 domain that modulates SAP97 association with ADAM10. Such mechanism is essential for ADAM10 trafficking from the Golgi outposts to the synapse, but does not affect ADAM10 transport from the endoplasmic reticulum. Notably, this process is altered in Alzheimer's disease brains. These results help in understanding the mechanism responsible for the modulation of ADAM10 intracellular path, and can constitute an innovative therapeutic strategy to finely tune ADAM10 shedding activity towards APP. PMID:25429624

Glycoengineering of CHO Cells to Improve Product Quality.

PubMed

Wang, Qiong; Yin, Bojiao; Chung, Cheng-Yu; Betenbaugh, Michael J

2017-01-01

Chinese hamster ovary (CHO) cells represent the predominant platform in biopharmaceutical industry for the production of recombinant biotherapeutic proteins, especially glycoproteins. These glycoproteins include oligosaccharide or glycan attachments that represent one of the principal components dictating product quality. Especially important are the N-glycan attachments present on many recombinant glycoproteins of commercial interest. Furthermore, altering the glycan composition can be used to modulate the production quality of a recombinant biotherapeutic from CHO and other mammalian hosts. This review first describes the glycosylation network in mammalian cells and compares the glycosylation patterns between CHO and human cells. Next genetic strategies used in CHO cells to modulate the sialylation patterns through overexpression of sialyltransfereases and other glycosyltransferases are summarized. In addition, other approaches to alter sialylation including manipulation of sialic acid biosynthetic pathways and inhibition of sialidases are described. Finally, this review also covers other strategies such as the glycosylation site insertion and manipulation of glycan heterogeneity to produce desired glycoforms for diverse biotechnology applications.

Improving a Synechocystis-based photoautotrophic chassis through systematic genome mapping and validation of neutral sites.

PubMed

Pinto, Filipe; Pacheco, Catarina C; Oliveira, Paulo; Montagud, Arnau; Landels, Andrew; Couto, Narciso; Wright, Phillip C; Urchueguía, Javier F; Tamagnini, Paula

2015-12-01

The use of microorganisms as cell factories frequently requires extensive molecular manipulation. Therefore, the identification of genomic neutral sites for the stable integration of ectopic DNA is required to ensure a successful outcome. Here we describe the genome mapping and validation of five neutral sites in the chromosome of Synechocystis sp. PCC 6803, foreseeing the use of this cyanobacterium as a photoautotrophic chassis. To evaluate the neutrality of these loci, insertion/deletion mutants were produced, and to assess their functionality, a synthetic green fluorescent reporter module was introduced. The constructed integrative vectors include a BioBrick-compatible multiple cloning site insulated by transcription terminators, constituting robust cloning interfaces for synthetic biology approaches. Moreover, Synechocystis mutants (chassis) ready to receive purpose-built synthetic modules/circuits are also available. This work presents a systematic approach to map and validate chromosomal neutral sites in cyanobacteria, and that can be extended to other organisms. © The Author 2015. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

Using NIR spatial illumination for detection and mapping chromophore changes during cerebral edema

NASA Astrophysics Data System (ADS)

Abookasis, David; Mathews, Marlon S.; Owen, Christopher M.; Binder, Devin K.; Linskey, Mark E.; Frostig, Ron D.; Tromberg, Bruce J.

2008-02-01

We used spatially modulated near-infrared (NIR) light to detect and map chromophore changes during cerebral edema in the rat neocortex. Cerebral edema was induced by intraperitoneal injections of free water (35% of body weight). Intracranial pressure (ICP) was measured with an optical fiber based Fabry-Perot interferometer sensor inserted into the parenchyma of the right frontal lobe during water administration. Increase in ICP from a baseline value of 10 cm-water to 145 cm-water was observed. Following induction of cerebral edema, there was a 26+/-1.7% increase in tissue concentration of deoxyhemoglobin and a 47+/-4.7%, 17+/-3% and 37+/-3.7% decrease in oxyhemoglobin, total hemoglobin concentration and cerebral tissue oxygen saturation levels, respectively. To the best of our knowledge, this is the first report describing the use of NIR spatial modulation of light for detecting and mapping changes in tissue concentrations of physiologic chromophores over time in response to cerebral edema.

Design for pressure regulating components

NASA Technical Reports Server (NTRS)

Wichmann, H.

1973-01-01

The design development for Pressure Regulating Components included a regulator component trade-off study with analog computer performance verification to arrive at a final optimized regulator configuration for the Space Storable Propulsion Module, under development for a Jupiter Orbiter mission. This application requires the pressure regulator to be capable of long-term fluorine exposure. In addition, individual but basically identical (for purposes of commonality) units are required for separate oxidizer and fuel pressurization. The need for dual units requires improvement in the regulation accuracy over present designs. An advanced regulator concept was prepared featuring redundant bellows, all metallic/ceramic construction, friction-free guidance of moving parts, gas damping, and the elimination of coil springs normally used for reference forces. The activities included testing of actual size seat/poppet components to determine actual discharge coefficients and flow forces. The resulting data was inserted into the computer model of the regulator. Computer simulation of the propulsion module performance over two mission profiles indicated satisfactory minimization of propellant residual requirements imposed by regulator performance uncertainties.

Monolithically integrated quantum dot optical modulator with Semiconductor optical amplifier for short-range optical communications

NASA Astrophysics Data System (ADS)

Yamamoto, Naokatsu; Akahane, Kouichi; Umezawa, Toshimasa; Kawanishi, Tetsuya

2015-04-01

A monolithically integrated quantum dot (QD) optical gain modulator (OGM) with a QD semiconductor optical amplifier (SOA) was successfully developed. Broadband QD optical gain material was used to achieve Gbps-order high-speed optical data transmission, and an optical gain change as high as approximately 6-7 dB was obtained with a low OGM voltage of 2.0 V. Loss of optical power due to insertion of the device was also effectively compensated for by the SOA section. Furthermore, it was confirmed that the QD-OGM/SOA device helped achieve 6.0-Gbps error-free optical data transmission over a 2.0-km-long photonic crystal fiber. We also successfully demonstrated generation of Gbps-order, high-speed, and error-free optical signals in the >5.5-THz broadband optical frequency bandwidth larger than the C-band. These results suggest that the developed monolithically integrated QD-OGM/SOA device will be an advantageous and compact means of increasing the usable optical frequency channels for short-reach communications.

The Role of Linkers in the Excited-State Dynamic Planarization Processes of Macrocyclic Oligothiophene 12-Mers.

PubMed

Kim, Woojae; Sung, Jooyoung; Park, Kyu Hyung; Shimizu, Hideyuki; Imamura, Mika; Han, Minwoo; Sim, Eunji; Iyoda, Masahiko; Kim, Dongho

2015-11-05

Linkers adjoining chromophores play an important role in modulating the structure of conjugated systems, which is bound up with their photophysical properties. However, to date, the focus of works dealing with linker effects was limited only to linear π-conjugated materials, and there have been no detailed studies on cyclic counterparts. Herein we report the linker effects on the dynamic planarization processes of π-conjugated macrocyclic oligothiophene 12-mers, where the different ratio between ethynylene and vinylene linkers was chosen to control the backbone rigidity. By analyzing transient fluorescence spectra, we demonstrate that the connecting linkers play a crucial role in the excited-state dynamics of cyclic conjugated systems. Faster dynamic planarization, longer exciton delocalization length, and higher degree of planarity were observed in vinylene inserted cyclic oligothiophenes. Molecular dynamics simulations and density functional theory calculations also stress the importance of the role of linkers in modulating the structure of cyclic oligothiophenes.

Magnetic-free non-reciprocity based on staggered commutation

PubMed Central

Reiskarimian, Negar; Krishnaswamy, Harish

2016-01-01

Lorentz reciprocity is a fundamental characteristic of the vast majority of electronic and photonic structures. However, non-reciprocal components such as isolators, circulators and gyrators enable new applications ranging from radio frequencies to optical frequencies, including full-duplex wireless communication and on-chip all-optical information processing. Such components today dominantly rely on the phenomenon of Faraday rotation in magneto-optic materials. However, they are typically bulky, expensive and not suitable for insertion in a conventional integrated circuit. Here we demonstrate magnetic-free linear passive non-reciprocity based on the concept of staggered commutation. Commutation is a form of parametric modulation with very high modulation ratio. We observe that staggered commutation enables time-reversal symmetry breaking within very small dimensions (λ/1,250 × λ/1,250 in our device), resulting in a miniature radio-frequency circulator that exhibits reduced implementation complexity, very low loss, strong non-reciprocity, significantly enhanced linearity and real-time reconfigurability, and is integrated in a conventional complementary metal–oxide–semiconductor integrated circuit for the first time. PMID:27079524

RHETT/EPDM Flight Hollow Cathode

NASA Technical Reports Server (NTRS)

Manzella, David; Patterson, Michael; Pastel, Michael

1997-01-01

Under the sponsorship of the BMDO Russian Hall Electric Thruster Technology program two xenon hollow cathodes, a flight unit and a flight spare were fabricated, acceptance tested and delivered to the Naval Research Laboratory for use on the Electric Propulsion Demonstration Module. These hollow cathodes, based on the International Space Station plasma contactor design, were fabricated at the NASA Lewis Research Center for use with a D-55 anode layer thruster in the first on-orbit operational application of this technology. The 2.2 Ampere nominal emission current of this device was obtained with a xenon flow rate of 0.6 mg/s. Ignition of the cathode discharge was accomplished through preheating the active electron emitter with a resistive heating element before application of a 650 volt ignition pulse between the emitter and an external starting electrode. The successful acceptance testing of the Electric Propulsion Demonstration Module utilizing these cathodes demonstrated the suitability of cathodes based on barium impregnated inserts in an enclosed keeper configuration for use with Hall thruster propulsion systems.

A Ka-Band Wide-Bandgap Solid-State Power Amplifier: Architecture Performance Estimates

NASA Technical Reports Server (NTRS)

Epp, L.; Khan, P.; Silva, A.

2005-01-01

Motivated by recent advances in wide-bandgap (WBG) gallium nitride (GaN) semiconductor technology, there is considerable interest in developing efficient solidstate power amplifiers (SSPAs) as an alternative to the traveling-wave tube amplifier (TWTA) for space applications. This article documents the results of a study to investigate power-combining technology and SSPA architectures that can enable a 120-W, 40 percent power-added efficiency (PAE) SSPA. Results of the study indicate that architectures based on at least three power combiner designs are likely to enable the target SSPA. The proposed architectures can power combine 16 to 32 individual monolithic microwave integrated circuits (MMICs) with >80 percent combining efficiency. This corresponds to MMIC requirements of 5- to 10-W output power and >48 percent PAE. For the three proposed architectures [1], detailed analysis and design of the power combiner are presented. The first architecture studied is based on a 16-way septum combiner that offers low loss and high isolation over the design band of 31 to 36 GHz. Analysis of a 2-way prototype septum combiner had an input match >25 dB, output match >30 dB, insertion loss <0.02 dB, and isolation >30 dB over the design band. A 16-way design, based on cascading this combiner in a binary fashion, is documented. The second architecture is based on a 24-way waveguide radial combiner. A prototype 24-way radial base was analyzed to have an input match >30 dB (under equal excitation of all input ports). The match of the mode transducer that forms the output of a radial combiner was found to be >27 dB. The functional bandwidth of the radial base and mode transducer, which together will form a radial combiner/divider, exceeded the design band. The third architecture employs a 32-way, parallel-plate radial combiner. Simulation results indicated an input match >24 dB, output match >22 dB, insertion loss <0.23 dB, and adjacent port isolation >20 dB over the design band. All three architectures utilize a low-loss MMIC amplifier module based on commercial MMIC packaging and a custom microstrip-to-rectangular-waveguide transition. The insertion loss of the module is expected to be 0.45 dB over the design band.

How Lipid Membranes Affect Pore Forming Toxin Activity.

PubMed

Rojko, Nejc; Anderluh, Gregor

2015-12-15

Pore forming toxins (PFTs) evolved to permeate the plasma membrane of target cells. This is achieved in a multistep mechanism that usually involves binding of soluble protein monomer to the lipid membrane, oligomerization at the plane of the membrane, and insertion of part of the polypeptide chain across the lipid membrane to form a conductive channel. Introduced pores allow uncontrolled transport of solutes across the membrane, inflicting damage to the target cell. PFTs are usually studied from the perspective of structure-function relationships, often neglecting the important role of the bulk membrane properties on the PFT mechanism of action. In this Account, we discuss how membrane lateral heterogeneity, thickness, and fluidity influence the pore forming process of PFTs. In general, lipid molecules are more accessible for binding in fluid membranes due to steric reasons. When PFT specifically binds ordered domains, it usually recognizes a specific lipid distribution pattern, like sphingomyelin (SM) clusters or SM/cholesterol complexes, and not individual lipid species. Lipid domains were also suggested to act as an additional concentration platform facilitating PFT oligomerization, but this is yet to be shown. The last stage in PFT action is the insertion of the transmembrane segment across the membranes to build the transmembrane pore walls. Conformational changes are a spontaneous process, and sufficient free energy has to be available for efficient membrane penetration. Therefore, fluid bilayers are permeabilized more readily in comparison to highly ordered and thicker liquid ordered lipid phase (Lo). Energetically more costly insertion into the Lo phase can be driven by the hydrophobic mismatch between the thinner liquid disordered phase (Ld) and large protein complexes, which are unable to tilt like single transmembrane segments. In the case of proteolipid pores, membrane properties can directly modulate pore size, stability, and even selectivity. Finally, events associated with pore formation can modulate properties of the lipid membrane and affect its organization. Model membranes do not necessarily reproduce the physicochemical properties of the native cellular membrane, and caution is needed when transferring results from model to native lipid membranes. In this context, the utilization of novel approaches that enable studying PFTs on living cells at a single molecule level should reveal complex protein-lipid membrane interactions in greater detail.

Elaboration and Evaluation of Contents about Hearing Health Inserted in Cybertutor

PubMed Central

Corrêa, Camila de Castro; Silva, Ricelly Avila da; Blasca, Wanderléia Quinhoneiro

2014-01-01

Introduction Cybertutor (electronic tutor) is a type of information and communication technology to disseminate knowledge about hearing, aiming at the prevention of hearing alterations and, when needed, early treatment, in addition to social inclusion of the hearing impaired. However, it is important to evaluate the level of language used in the content and the subjective perception of the target public regarding improvements of the tool. Objective To improve content about hearing health inserted in a cybertutor and to evaluate the level of legibility and the quality of the content and material made available. Method For the construction of the content, text and audiovisual resources were used, based on scientific publications, and were evaluated objectively with Flesch Reading Ease test and subjectively with a questionnaire created by the authors and answered by 10 ninth-year pupils. Results Two modules on hearing health were created, “Hearing Health” and “Intervention and Rehabilitation,” which received Flesch scores of 50.8 and 51.4%, respectively, making it necessary to have a sixth- to ninth-year education to understand the material. The students' evaluation in reference to language and material showed that 55.5% considered the contents excellent; 38.2% classified the contents as satisfactory; 6.3% considered them reasonable; and 0% classified them as unsatisfactory. Conclusion The contents inserted in the cybertutor about hearing health presented a language level considered easy for the age group of the target population, in addition to receiving good subjective evaluation from the pupils, facilitating access to the information. PMID:25992075

Response of Escherichia coli growth rate to osmotic shock.

PubMed

Rojas, Enrique; Theriot, Julie A; Huang, Kerwyn Casey

2014-05-27

It has long been proposed that turgor pressure plays an essential role during bacterial growth by driving mechanical expansion of the cell wall. This hypothesis is based on analogy to plant cells, for which this mechanism has been established, and on experiments in which the growth rate of bacterial cultures was observed to decrease as the osmolarity of the growth medium was increased. To distinguish the effect of turgor pressure from pressure-independent effects that osmolarity might have on cell growth, we monitored the elongation of single Escherichia coli cells while rapidly changing the osmolarity of their media. By plasmolyzing cells, we found that cell-wall elastic strain did not scale with growth rate, suggesting that pressure does not drive cell-wall expansion. Furthermore, in response to hyper- and hypoosmotic shock, E. coli cells resumed their preshock growth rate and relaxed to their steady-state rate after several minutes, demonstrating that osmolarity modulates growth rate slowly, independently of pressure. Oscillatory hyperosmotic shock revealed that although plasmolysis slowed cell elongation, the cells nevertheless "stored" growth such that once turgor was reestablished the cells elongated to the length that they would have attained had they never been plasmolyzed. Finally, MreB dynamics were unaffected by osmotic shock. These results reveal the simple nature of E. coli cell-wall expansion: that the rate of expansion is determined by the rate of peptidoglycan insertion and insertion is not directly dependent on turgor pressure, but that pressure does play a basic role whereby it enables full extension of recently inserted peptidoglycan.

Response of Escherichia coli growth rate to osmotic shock

PubMed Central

Rojas, Enrique; Theriot, Julie A.; Huang, Kerwyn Casey

2014-01-01

It has long been proposed that turgor pressure plays an essential role during bacterial growth by driving mechanical expansion of the cell wall. This hypothesis is based on analogy to plant cells, for which this mechanism has been established, and on experiments in which the growth rate of bacterial cultures was observed to decrease as the osmolarity of the growth medium was increased. To distinguish the effect of turgor pressure from pressure-independent effects that osmolarity might have on cell growth, we monitored the elongation of single Escherichia coli cells while rapidly changing the osmolarity of their media. By plasmolyzing cells, we found that cell-wall elastic strain did not scale with growth rate, suggesting that pressure does not drive cell-wall expansion. Furthermore, in response to hyper- and hypoosmotic shock, E. coli cells resumed their preshock growth rate and relaxed to their steady-state rate after several minutes, demonstrating that osmolarity modulates growth rate slowly, independently of pressure. Oscillatory hyperosmotic shock revealed that although plasmolysis slowed cell elongation, the cells nevertheless “stored” growth such that once turgor was reestablished the cells elongated to the length that they would have attained had they never been plasmolyzed. Finally, MreB dynamics were unaffected by osmotic shock. These results reveal the simple nature of E. coli cell-wall expansion: that the rate of expansion is determined by the rate of peptidoglycan insertion and insertion is not directly dependent on turgor pressure, but that pressure does play a basic role whereby it enables full extension of recently inserted peptidoglycan. PMID:24821776

BamA POTRA Domain Interacts with a Native Lipid Membrane Surface.

PubMed

Fleming, Patrick J; Patel, Dhilon S; Wu, Emilia L; Qi, Yifei; Yeom, Min Sun; Sousa, Marcelo Carlos; Fleming, Karen G; Im, Wonpil

2016-06-21

The outer membrane of Gram-negative bacteria is an asymmetric membrane with lipopolysaccharides on the external leaflet and phospholipids on the periplasmic leaflet. This outer membrane contains mainly β-barrel transmembrane proteins and lipidated periplasmic proteins (lipoproteins). The multisubunit protein β-barrel assembly machine (BAM) catalyzes the insertion and folding of the β-barrel proteins into this membrane. In Escherichia coli, the BAM complex consists of five subunits, a core transmembrane β-barrel with a long periplasmic domain (BamA) and four lipoproteins (BamB/C/D/E). The BamA periplasmic domain is composed of five globular subdomains in tandem called POTRA motifs that are key to BAM complex formation and interaction with the substrate β-barrel proteins. The BAM complex is believed to undergo conformational cycling while facilitating insertion of client proteins into the outer membrane. Reports describing variable conformations and dynamics of the periplasmic POTRA domain have been published. Therefore, elucidation of the conformational dynamics of the POTRA domain in full-length BamA is important to understand the function of this molecular complex. Using molecular dynamics simulations, we present evidence that the conformational flexibility of the POTRA domain is modulated by binding to the periplasmic surface of a native lipid membrane. Furthermore, membrane binding of the POTRA domain is compatible with both BamB and BamD binding, suggesting that conformational selection of different POTRA domain conformations may be involved in the mechanism of BAM-facilitated insertion of outer membrane β-barrel proteins. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

The Werner syndrome protein limits the error-prone 8-oxo-dG lesion bypass activity of human DNA polymerase kappa

PubMed Central

Maddukuri, Leena; Ketkar, Amit; Eddy, Sarah; Zafar, Maroof K.; Eoff, Robert L.

2014-01-01

Human DNA polymerase kappa (hpol κ) is the only Y-family member to preferentially insert dAMP opposite 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-oxo-dG) during translesion DNA synthesis. We have studied the mechanism of action by which hpol κ activity is modulated by the Werner syndrome protein (WRN), a RecQ helicase known to influence repair of 8-oxo-dG. Here we show that WRN stimulates the 8-oxo-dG bypass activity of hpol κ in vitro by enhancing the correct base insertion opposite the lesion, as well as extension from dC:8-oxo-dG base pairs. Steady-state kinetic analysis reveals that WRN improves hpol κ-catalyzed dCMP insertion opposite 8-oxo-dG ∼10-fold and extension from dC:8-oxo-dG by 2.4-fold. Stimulation is primarily due to an increase in the rate constant for polymerization (kpol), as assessed by pre-steady-state kinetics, and it requires the RecQ C-terminal (RQC) domain. In support of the functional data, recombinant WRN and hpol κ were found to physically interact through the exo and RQC domains of WRN, and co-localization of WRN and hpol κ was observed in human cells treated with hydrogen peroxide. Thus, WRN limits the error-prone bypass of 8-oxo-dG by hpol κ, which could influence the sensitivity to oxidative damage that has previously been observed for Werner's syndrome cells. PMID:25294835

Radio-frequency Bloch-transistor electrometer.

PubMed

Zorin, A B

2001-04-09

A quantum electrometer is proposed which is based on charge modulation of the Josephson supercurrent in the Bloch transistor inserted in a superconducting ring. As this ring is inductively coupled to a high- Q resonance tank circuit, the variations of the charge on the transistor island are converted into variations of amplitude and phase of oscillations in the tank. These variations are amplified and then detected. At sufficiently low temperature of the tank the device sensitivity is determined by the energy resolution of the amplifier, that can be reduced down to the standard quantum limit of 1 / 2Planck's over 2pi. A "back-action-evading" scheme of subquantum limit measurements is proposed.

Wavelength-tunable Q-switched Raman fiber laser

NASA Astrophysics Data System (ADS)

Ye, Jun; Xu, Jiangming; Zhang, Hanwei; Wu, Jian; Zhou, Pu

2018-03-01

In this presentation, a wavelength-tunable Q-switched Raman fiber laser is presented for the first time, which has a backward pumped configuration, including a section of 3 km passive fiber, a homemade tunable pump source and a highly reflective fiber loop mirror. The output wavelength of the Raman fiber laser can be tuned continuously with ~44 nm range via adjusting the pump wavelength. By inserting an acoustic-optical modulator, the Q-value of the cavity can be switched between high and low level. As a result, pulsed output with a repetition rate of 500 kHz and duration time of 60-80 ns is achieved.

Dosimetric impact of a change in breathing period on VMAT stereotactic ablative body radiotherapy

NASA Astrophysics Data System (ADS)

Olding, T.; Alexander, KM

2017-05-01

The dosimetric impact of a change in breathing period during treatment was assessed for a volumetric modulated arc therapy (VMAT) stereotactic ablative radiotherapy (SABR) lung plan optimized according to our centre’s planning protocol. Plan delivery was evaluated at three breathing rates ranging from 7 to 23 breaths-per-minute (BPM) against the planning anatomy (15 BPM) calculated dose. Dynamic ion chamber, EBT3 film and Fricke-xylenol orange-gelatin (FXG) gel measurements were acquired using a motion phantom with appropriate inserts for each dosimeter. The results show good agreement between measured and calculated plan dose within the internal gross tumour volume (IGTV) target.

Solid-State Lighting Module (SSLM)

NASA Technical Reports Server (NTRS)

2008-01-01

The project's goal was to build a light-emitting-diode (LED)-based light fixture that is identical in fit, form, and function to the existing International Space Station (ISS) General Luminaire Assembly (GLA) light fixture and fly it on the ISS in early FY 2008 as a Station Detailed Test Objective (SDTO). Our design offers the following strengths: proven component hardware: Our design uses components flown in other KSC-developed hardware; heat path thermal pad: LED array heat is transferred from the circuit board by silicon pad, negating the need for a cooling fan; variable colorimetry: The output light color can be changed by inserting different LED combinations.

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

Anderson, Mark A.; Bigelow, Matthew; Gilkey, Jeff C.

The Super Strypi Navigation, Guidance & Control Software is a real-time implementation of the navigation, guidance and control algorithms designed to deliver a payload to a desired orbit for the rail launched Super Strypi launch vehicle. The software contains all flight control algorithms required from pre-launch until orbital insertion. The flight sequencer module calls the NG&C functions at the appropriate times of flight. Additional functionality includes all the low level drivers and I/O for communicating to other systems within the launch vehicle and to the ground support equipment. The software is designed such that changes to the launch location andmore » desired orbit can be changed without recompiling the code.« less

Crew Exploration Vehicle Service Module Ascent Abort Coverage

NASA Technical Reports Server (NTRS)

Tedesco, Mark B.; Evans, Bryan M.; Merritt, Deborah S.; Falck, Robert D.

2007-01-01

The Crew Exploration Vehicle (CEV) is required to maintain continuous abort capability from lift off through destination arrival. This requirement is driven by the desire to provide the capability to safely return the crew to Earth after failure scenarios during the various phases of the mission. This paper addresses abort trajectory design considerations, concept of operations and guidance algorithm prototypes for the portion of the ascent trajectory following nominal jettison of the Launch Abort System (LAS) until safe orbit insertion. Factors such as abort system performance, crew load limits, natural environments, crew recovery, and vehicle element disposal were investigated to determine how to achieve continuous vehicle abort capability.

A study of high density bit transition requirements versus the effects on BCH error correcting coding

NASA Technical Reports Server (NTRS)

Ingels, F.; Schoggen, W. O.

1981-01-01

Several methods for increasing bit transition densities in a data stream are summarized, discussed in detail, and compared against constraints imposed by the 2 MHz data link of the space shuttle high rate multiplexer unit. These methods include use of alternate pulse code modulation waveforms, data stream modification by insertion, alternate bit inversion, differential encoding, error encoding, and use of bit scramblers. The psuedo-random cover sequence generator was chosen for application to the 2 MHz data link of the space shuttle high rate multiplexer unit. This method is fully analyzed and a design implementation proposed.

Atto-Joule, high-speed, low-loss plasmonic modulator based on adiabatic coupled waveguides

NASA Astrophysics Data System (ADS)

Dalir, Hamed; Mokhtari-Koushyar, Farzad; Zand, Iman; Heidari, Elham; Xu, Xiaochuan; Pan, Zeyu; Sun, Shuai; Amin, Rubab; Sorger, Volker J.; Chen, Ray T.

2018-05-01

In atomic multi-level systems, adiabatic elimination (AE) is a method used to minimize complicity of the system by eliminating irrelevant and strongly coupled levels by detuning them from one another. Such a three-level system, for instance, can be mapped onto physically in the form of a three-waveguide system. Actively detuning the coupling strength between the respective waveguide modes allows modulating light to propagate through the device, as proposed here. The outer waveguides act as an effective two-photonic-mode system similar to ground and excited states of a three-level atomic system, while the center waveguide is partially plasmonic. In AE regime, the amplitude of the middle waveguide oscillates much faster when compared to the outer waveguides leading to a vanishing field build up. As a result, the plasmonic intermediate waveguide becomes a "dark state," hence nearly zero decibel insertion loss is expected with modulation depth (extinction ratio) exceeding 25 dB. Here, the modulation mechanism relies on switching this waveguide system from a critical coupling regime to AE condition via electrostatically tuning the free-carrier concentration and hence the optical index of a thin indium thin oxide (ITO) layer resides in the plasmonic center waveguide. This alters the effective coupling length and the phase mismatching condition thus modulating in each of its outer waveguides. Our results also promise a power consumption as low as 49.74aJ/bit. Besides, we expected a modulation speed of 160 GHz reaching to millimeter wave range applications. Such anticipated performance is a direct result of both the unity-strong tunability of the plasmonic optical mode in conjunction with utilizing ultra-sensitive modal coupling between the critically coupled and the AE regimes. When taken together, this new class of modulators paves the way for next generation both for energy and speed conscience optical short-reach communication such as those found in interconnects.

Thermal management improvement of an air-cooled high-power lithium-ion battery by embedding metal foam

NASA Astrophysics Data System (ADS)

Mohammadian, Shahabeddin K.; Rassoulinejad-Mousavi, Seyed Moein; Zhang, Yuwen

2015-11-01

Effect of embedding aluminum porous metal foam inside the flow channels of an air-cooled Li-ion battery module was studied to improve its thermal management. Four different cases of metal foam insert were examined using three-dimensional transient numerical simulations. The effects of permeability and porosity of the porous medium as well as state of charge were investigated on the standard deviation of the temperature field and maximum temperature inside the battery in all four cases. Compared to the case of no porous insert, embedding aluminum metal foam in the air flow channel significantly improved the thermal management of Li-ion battery cell. The results also indicated that, decreasing the porosity of the porous structure decreases both standard deviation of the temperature field and maximum temperature inside the battery. Moreover, increasing the permeability of the metal foam drops the maximum temperature inside the battery while decreasing this property leads to improving the temperature uniformity. Our results suggested that, among the all studied cases, desirable temperature uniformity and maximum temperature were achieved when two-third and the entire air flow channel is filled with aluminum metal foam, respectively.

A putative regulatory genetic locus modulates virulence in the pathogen Leptospira interrogans.

PubMed

Eshghi, Azad; Becam, Jérôme; Lambert, Ambroise; Sismeiro, Odile; Dillies, Marie-Agnès; Jagla, Bernd; Wunder, Elsio A; Ko, Albert I; Coppee, Jean-Yves; Goarant, Cyrille; Picardeau, Mathieu

2014-06-01

Limited research has been conducted on the role of transcriptional regulators in relation to virulence in Leptospira interrogans, the etiological agent of leptospirosis. Here, we identify an L. interrogans locus that encodes a sensor protein, an anti-sigma factor antagonist, and two genes encoding proteins of unknown function. Transposon insertion into the gene encoding the sensor protein led to dampened transcription of the other 3 genes in this locus. This lb139 insertion mutant (the lb139(-) mutant) displayed attenuated virulence in the hamster model of infection and reduced motility in vitro. Whole-transcriptome analyses using RNA sequencing revealed the downregulation of 115 genes and the upregulation of 28 genes, with an overrepresentation of gene products functioning in motility and signal transduction and numerous gene products with unknown functions, predicted to be localized to the extracellular space. Another significant finding encompassed suppressed expression of the majority of the genes previously demonstrated to be upregulated at physiological osmolarity, including the sphingomyelinase C precursor Sph2 and LigB. We provide insight into a possible requirement for transcriptional regulation as it relates to leptospiral virulence and suggest various biological processes that are affected due to the loss of native expression of this genetic locus.

Iodine insertion and dispersion of refractive index in organic single crystal semiconductor.

PubMed

Kwon, Seonho; Bae, Junwan; Lee, I J

2018-02-20

Insertion of halogens such as bromine or iodine affects the electronic polarizability of ions and the local field inside the medium, and thus modifies the refractive index. Acquiring precise knowledge of the dispersion of refractive index and ultimately tailoring conventional semiconductors for wide-range refractive index control have been a vital issue to resolve before realizing advanced organic optoelectronic devices. In this report, dispersions of the refractive index of a single crystal tetramethyltetraselenafulvalene [C 10 H 12 Se 4 ] (TMTSF) are thoroughly studied from broadband interference modulations of photoluminescence (PL) spectra at various temperatures and doping levels. A large enhancement of the refractive index, more than 20% of the intrinsic value, is achieved with inclusion of a small composition of iodide ions, while the structural and optical properties remain mostly intact. Nearly temperature independent dispersion of the refractive index suggests that, unlike most polymers in which the thermal expansion coefficient dominates over the change of polarizability with temperature, the latter enhances significantly and may become more or less comparable to the thermal expansion coefficient given by 1.71 × 10 -4 /K, when single crystal TMTSF is doped by iodine.

PubMed Central

DE LOS ANGELES BEYTÍA, MARIA; VRY, JULIA; KIRSCHNER, JANBERND

2012-01-01

Duchenne muscular dystrophy (DMD) is a disease linked to the X-chromosome which affects 1 in 3,600-6,000 newborn males. It is manifested by the absence of the dystrophin protein in muscle fibres, which causes progressive damage leading to death in the third decade of life. The only medication so far shown to be effective in delaying the progression of this illness are corticosteroids, which have been shown to increase muscle strength in randomised controlled studies; long-term studies have demonstrated that they prolong walking time and retard the progression of respiratory dysfunction, dilated cardiomyopathy and scoliosis. Several potential drugs are now being investigated. Genetic therapy, involving the insertion of a dystrophin gene through a vector, has proven effective in animals but not humans. Currently under clinical study is Ataluren, a molecule that binds with ribosomes and may allow the insertion of an aminoacid in the premature termination codon, and exon-skipping, which binds with RNA and excludes specific sites of RNA splicing, producing a dystrophin that is smaller but functional. There are also studies attempting to modulate other muscular proteins, such as myostatin and utrophin, to reduce symptoms. This paper does not address cardiomyopathy treatment in DMD patients. PMID:22655510

Fiber sensor assisted in-vivo needle guidance for minimally invasive procedures (Conference Presentation)

NASA Astrophysics Data System (ADS)

Baghdadchi, Saharnaz; Chao, Cherng; Esener, Sadik; Mattrey, Robert F.; Eghtedari, Mohammad A.

2017-02-01

Image-guided procedures are performed frequently by radiologists to insert a catheter within a target vessel or lumen or to perform biopsy of a lesion. For instance, an interventional radiologist uses fluoroscopy during percutaneous biliary drainage procedure (a procedure during which a catheter is inserted through the skin to drain the bile from liver) to identify the location of the needle tip within liver parenchyma, hepatic blood vessel or bile duct. However, the identification of the target organ under fluoroscopy exposes the patient to x-ray irradiation, which may be significant if the time of procedure is prolonged. We have designed a fiber core needle system that may help the radiologist identify the location of the needle tip in real time without exposing the patient to x-ray. Our needle system transmits a low power modulated light into the tissue through a fiber cable embedded in the needle and detects the backscattered light using another fiber inside the needle. We were able to successfully distinguish the location of our prototype needle tip inside a cow liver phantom to identify if the needle tip was within liver parenchyma, liver vessels, or in the bile duct based on the recorded backscattered light.

Efficient Exploration of Membrane-Associated Phenomena at Atomic Resolution.

PubMed

Vermaas, Josh V; Baylon, Javier L; Arcario, Mark J; Muller, Melanie P; Wu, Zhe; Pogorelov, Taras V; Tajkhorshid, Emad

2015-06-01

Biological membranes constitute a critical component in all living cells. In addition to providing a conducive environment to a wide range of cellular processes, including transport and signaling, mounting evidence has established active participation of specific lipids in modulating membrane protein function through various mechanisms. Understanding lipid-protein interactions underlying these mechanisms at a sufficiently high resolution has proven extremely challenging, partly due to the semi-fluid nature of the membrane. In order to address this challenge computationally, multiple methods have been developed, including an alternative membrane representation termed highly mobile membrane mimetic (HMMM) in which lateral lipid diffusion has been significantly enhanced without compromising atomic details. The model allows for efficient sampling of lipid-protein interactions at atomic resolution, thereby significantly enhancing the effectiveness of molecular dynamics simulations in capturing membrane-associated phenomena. In this review, after providing an overview of HMMM model development, we will describe briefly successful application of the model to study a variety of membrane processes, including lipid-dependent binding and insertion of peripheral proteins, the mechanism of phospholipid insertion into lipid bilayers, and characterization of optimal tilt angle of transmembrane helices. We conclude with practical recommendations for proper usage of the model in simulation studies of membrane processes.

Effects of lesions of the amygdala central nucleus on autoshaped lever pressing

PubMed Central

Chang, Stephen E.; Wheeler, Daniel S.; Holland, Peter C.

2012-01-01

Neutral cues paired with rewards often appear to acquire motivational significance, as if the incentive motivational value of the reward is transferred to the cue. Such cues have been reported to modulate the performance of instrumental action (Pavlovian-instrumental transfer, PIT), serve as conditioned reinforcers in the establishment of new learning, and be the targets of approach and other cue-directed behaviors. Here we examined the effects of lesions of the amygdala central nucleus (CeA) on the acquisition of discriminative autoshaped lever-pressing. Insertion of one lever into the experimental chamber was reinforced by sucrose delivery, but insertion of another lever was not reinforced. Although sucrose delivery was not contingent on lever pressing, both CeA- and sham-lesioned rats rapidly came to press the reinforced but not the nonreinforced lever. Despite their showing little evidence of impairments in autoshaped lever pressing, these same CeA-lesioned rats showed significant deficits in the expression of PIT in a subsequent phase of the experiment. The lack of impaired autoshaping in CeA-lesioned rats contrasts with effects previously reported for conditioned orienting responses (ORs) and for other putative measures of incentive learning including PIT and conditioned approach to visual cues. PMID:22386516

A conserved genetic module that encodes the major virion components in both the coliphage T4 and the marine cyanophage S-PM2

PubMed Central

Hambly, Emma; Tétart, Francoise; Desplats, Carine; Wilson, William H.; Krisch, Henry M.; Mann, Nicholas H.

2001-01-01

Sequence analysis of a 10-kb region of the genome of the marine cyanomyovirus S-PM2 reveals a homology to coliphage T4 that extends as a contiguous block from gene (g)18 to g23. The order of the S-PM2 genes in this region is similar to that of T4, but there are insertions and deletions of small ORFs of unknown function. In T4, g18 codes for the tail sheath, g19, the tail tube, g20, the head portal protein, g21, the prohead core protein, g22, a scaffolding protein, and g23, the major capsid protein. Thus, the entire module that determines the structural components of the phage head and contractile tail is conserved between T4 and this cyanophage. The significant differences in the morphology of these phages must reflect the considerable divergence of the amino acid sequence of their homologous virion proteins, which uniformly exceeds 50%. We suggest that their enormous diversity in the sea could be a result of genetic shuffling between disparate phages mediated by such commonly shared modules. These conserved sequences could facilitate genetic exchange by providing partially homologous substrates for recombination between otherwise divergent phage genomes. Such a mechanism would thus expand the pool of phage genes accessible by recombination to all those phages that share common modules. PMID:11553768

Simultaneous backward data transmission and power harvesting in an ultrasonic transcutaneous energy transfer link employing acoustically dependent electric impedance modulation.

PubMed

Ozeri, Shaul; Shmilovitz, Doron

2014-09-01

The advancement and miniaturization of body implanted medical devices pose several challenges to Ultrasonic Transcutaneous Energy Transfer (UTET), such as the need to reduce the size of the piezoelectric resonator, and the need to maximize the UTET link power-transfer efficiency. Accordingly, the same piezoelectric resonator that is used for energy harvesting at the body implant, may also be used for ultrasonic backward data transfer, for instance, through impedance modulation. This paper presents physical considerations and design guidelines of the body implanted transducer of a UTET link with impedance modulation for a backward data transfer. The acoustic matching design procedure was based on the 2×2 transfer matrix chain analysis, in addition to the Krimholtz Leedom and Matthaei KLM transmission line model. The UTET power transfer was carried out at a frequency of 765 kHz, continuous wave (CW) mode. The backward data transfer was attained by inserting a 9% load resistance variation around its matched value (550 Ohm), resulting in a 12% increase in the acoustic reflection coefficient. A backward data transmission rate of 1200 bits/s was experimentally demonstrated using amplitude shift keying, simultaneously with an acoustic power transfer of 20 mW to the implant. Copyright © 2014 Elsevier B.V. All rights reserved.

Development of versatile non-homologous end joining-based knock-in module for genome editing.

PubMed

Sawatsubashi, Shun; Joko, Yudai; Fukumoto, Seiji; Matsumoto, Toshio; Sugano, Shigeo S

2018-01-12

CRISPR/Cas9-based genome editing has dramatically accelerated genome engineering. An important aspect of genome engineering is efficient knock-in technology. For improved knock-in efficiency, the non-homologous end joining (NHEJ) repair pathway has been used over the homology-dependent repair pathway, but there remains a need to reduce the complexity of the preparation of donor vectors. We developed the versatile NHEJ-based knock-in module for genome editing (VIKING). Using the consensus sequence of the time-honored pUC vector to cut donor vectors, any vector with a pUC backbone could be used as the donor vector without customization. Conditions required to minimize random integration rates of the donor vector were also investigated. We attempted to isolate null lines of the VDR gene in human HaCaT keratinocytes using knock-in/knock-out with a selection marker cassette, and found 75% of clones isolated were successfully knocked-in. Although HaCaT cells have hypotetraploid genome composition, the results suggest multiple clones have VDR null phenotypes. VIKING modules enabled highly efficient knock-in of any vectors harboring pUC vectors. Users now can insert various existing vectors into an arbitrary locus in the genome. VIKING will contribute to low-cost genome engineering.

MYC2 Differentially Modulates Diverse Jasmonate-Dependent Functions in Arabidopsis[W

PubMed Central

Dombrecht, Bruno; Xue, Gang Ping; Sprague, Susan J.; Kirkegaard, John A.; Ross, John J.; Reid, James B.; Fitt, Gary P.; Sewelam, Nasser; Schenk, Peer M.; Manners, John M.; Kazan, Kemal

2007-01-01

The Arabidopsis thaliana basic helix-loop-helix Leu zipper transcription factor (TF) MYC2/JIN1 differentially regulates jasmonate (JA)-responsive pathogen defense (e.g., PDF1.2) and wound response (e.g., VSP) genes. In this study, genome-wide transcriptional profiling of wild type and mutant myc2/jin1 plants followed by functional analyses has revealed new roles for MYC2 in the modulation of diverse JA functions. We found that MYC2 negatively regulates Trp and Trp-derived secondary metabolism such as indole glucosinolate biosynthesis during JA signaling. Furthermore, MYC2 positively regulates JA-mediated resistance to insect pests, such as Helicoverpa armigera, and tolerance to oxidative stress, possibly via enhanced ascorbate redox cycling and flavonoid biosynthesis. Analyses of MYC2 cis binding elements and expression of MYC2-regulated genes in T-DNA insertion lines of a subset of MYC2–regulated TFs suggested that MYC2 might modulate JA responses via differential regulation of an intermediate spectrum of TFs with activating or repressing roles in JA signaling. MYC2 also negatively regulates its own expression, and this may be one of the mechanisms used in fine-tuning JA signaling. Overall, these results provide new insights into the function of MYC2 and the transcriptional coordination of the JA signaling pathway. PMID:17616737

Fluorescence diffuse tomography of small animals with DsRed2 fluorescent protein

NASA Astrophysics Data System (ADS)

Turchin, I. V.; Plehanov, V. I.; Orlova, A. G.; Kamenskiy, V. A.; Kleshnin, M. S.; Shirmanova, M. V.; Shakhova, N. M.; Balalaeva, I. V.; Savitskiy, A. P.

2006-05-01

Fluorescent compounds are used as markers to diagnose oncological diseases, to study molecular processes typical for carcinogenesis, and to investigate metastasis formation and tumor regress under the influence of therapeutics. Different types of tomography, such as continuous wave (CW), frequency-domain (FD), and time-domain (TD) tomography, allow fluorescence imaging of tumors located deep in human or animal tissue. In this work, preliminary results of the frequency domain fluorescent diffuse tomography (FDT) method in application to DsRed2 protein as a fluorescent agent are presented. For the first step of our experiments, we utilized low-frequency amplitude modulation (1 kHz) of second harmonic of Nd: YAG (532 nm). The transilluminative configuration was used in the setup. The results of post mortem experiments with capsules containing DsRed2 inserted inside the esophagus of a 3-day-old hairless rat to simulate tumor are shown. An algorithm of processing fluorescent images based on calculating the zero of maximum curvature has been applied to detect fluorescent inclusion boundaries in the image. This work demonstrates the potential capability of the FDT method for imaging deep fluorescent tumors in human tissue or animal models of human cancer. Improvement of the setup can be accomplished by using high-frequency modulation (using a 110-MHz acoustooptical modulator).

γTools: A modular multifunction phantom for quality assurance in GammaKnife treatments.

PubMed

Calusi, Silvia; Noferini, Linhsia; Marrazzo, Livia; Casati, Marta; Arilli, Chiara; Compagnucci, Antonella; Talamonti, Cinzia; Scoccianti, Silvia; Greto, Daniela; Bordi, Lorenzo; Livi, Lorenzo; Pallotta, Stefania

2017-11-01

We present the γTools, a new phantom designed to assess geometric and dosimetric accuracy in Gamma Knife treatments, together with first tests and results of applications. The phantom is composed of two modules: the imaging module, a regular grid of 1660 control points to evaluate image distortions and image registration result and the dosimetry module for delivered dose distribution measurements. The phantom is accompanied by a MatLab routine for image distortions quantification. Dose measurement are performed with Gafchromic films fixed between two inserts and placed in various positions and orientations inside the dosimetry module thus covering a volume comparable to the full volume of a head. Tests performed to assess the accuracy and precision of the imaging module demonstrated sub-millimetric values. As an example of possible applications, the phantom was employed to measure image distortions of two MRI scanners and to perform dosimetric studies of single shots delivered to homogeneous and heterogeneous materials. Due to the phantom material, the measured absolute dose do not correspond to the planned dose; doses comparisons are thus carried out between normalized dose distributions. Finally, an end-to-end test was carried out in the treatment of a neuroma-like target which resulted in a 100% gamma passing rate (2% local, 2 mm) and a distance between the real target perimeter and the prescription isodose centroids of about 1 mm. The tests demonstrate that the proposed phantom is suitable to assess both the geometrical and relative dosimetric accuracy of Gamma Knife radiosurgery treatments. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

The Nuclear Energy Advanced Modeling and Simulation Safeguards and Separations Reprocessing Plant Toolkit

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

McCaskey, Alex; Billings, Jay Jay; de Almeida, Valmor F

2011-08-01

This report details the progress made in the development of the Reprocessing Plant Toolkit (RPTk) for the DOE Nuclear Energy Advanced Modeling and Simulation (NEAMS) program. RPTk is an ongoing development effort intended to provide users with an extensible, integrated, and scalable software framework for the modeling and simulation of spent nuclear fuel reprocessing plants by enabling the insertion and coupling of user-developed physicochemical modules of variable fidelity. The NEAMS Safeguards and Separations IPSC (SafeSeps) and the Enabling Computational Technologies (ECT) supporting program element have partnered to release an initial version of the RPTk with a focus on software usabilitymore » and utility. RPTk implements a data flow architecture that is the source of the system's extensibility and scalability. Data flows through physicochemical modules sequentially, with each module importing data, evolving it, and exporting the updated data to the next downstream module. This is accomplished through various architectural abstractions designed to give RPTk true plug-and-play capabilities. A simple application of this architecture, as well as RPTk data flow and evolution, is demonstrated in Section 6 with an application consisting of two coupled physicochemical modules. The remaining sections describe this ongoing work in full, from system vision and design inception to full implementation. Section 3 describes the relevant software development processes used by the RPTk development team. These processes allow the team to manage system complexity and ensure stakeholder satisfaction. This section also details the work done on the RPTk ``black box'' and ``white box'' models, with a special focus on the separation of concerns between the RPTk user interface and application runtime. Section 4 and 5 discuss that application runtime component in more detail, and describe the dependencies, behavior, and rigorous testing of its constituent components.« less

Functional conservation between rodents and chicken of regulatory sequences driving skeletal muscle gene expression in transgenic chickens

PubMed Central

2010-01-01

Background Regulatory elements that control expression of specific genes during development have been shown in many cases to contain functionally-conserved modules that can be transferred between species and direct gene expression in a comparable developmental pattern. An example of such a module has been identified at the rat myosin light chain (MLC) 1/3 locus, which has been well characterised in transgenic mouse studies. This locus contains two promoters encoding two alternatively spliced isoforms of alkali myosin light chain. These promoters are differentially regulated during development through the activity of two enhancer elements. The MLC3 promoter alone has been shown to confer expression of a reporter gene in skeletal and cardiac muscle in transgenic mice and the addition of the downstream MLC enhancer increased expression levels in skeletal muscle. We asked whether this regulatory module, sufficient for striated muscle gene expression in the mouse, would drive expression in similar domains in the chicken. Results We have observed that a conserved downstream MLC enhancer is present in the chicken MLC locus. We found that the rat MLC1/3 regulatory elements were transcriptionally active in chick skeletal muscle primary cultures. We observed that a single copy lentiviral insert containing this regulatory cassette was able to drive expression of a lacZ reporter gene in the fast-fibres of skeletal muscle in chicken in three independent transgenic chicken lines in a pattern similar to the endogenous MLC locus. Reporter gene expression in cardiac muscle tissues was not observed for any of these lines. Conclusions From these results we conclude that skeletal expression from this regulatory module is conserved in a genomic context between rodents and chickens. This transgenic module will be useful in future investigations of muscle development in avian species. PMID:20184756

Assembly of the Arp5 (Actin-related Protein) Subunit Involved in Distinct INO80 Chromatin Remodeling Activities*

PubMed Central

Yao, Wei; Beckwith, Sean L.; Zheng, Tina; Young, Thomas; Dinh, Van T.; Ranjan, Anand; Morrison, Ashby J.

2015-01-01

ATP-dependent chromatin remodeling, which repositions and restructures nucleosomes, is essential to all DNA-templated processes. The INO80 chromatin remodeling complex is an evolutionarily conserved complex involved in diverse cellular processes, including transcription, DNA repair, and replication. The functional diversity of the INO80 complex can, in part, be attributed to specialized activities of distinct subunits that compose the complex. Furthermore, structural analyses have identified biochemically discrete subunit modules that assemble along the Ino80 ATPase scaffold. Of particular interest is the Saccharomyces cerevisiae Arp5-Ies6 module located proximal to the Ino80 ATPase and the Rvb1-Rvb2 helicase module needed for INO80-mediated in vitro activity. In this study we demonstrate that the previously uncharacterized Ies2 subunit is required for Arp5-Ies6 association with the catalytic components of the INO80 complex. In addition, Arp5-Ies6 module assembly with the INO80 complex is dependent on distinct conserved domains within Arp5, Ies6, and Ino80, including the spacer region within the Ino80 ATPase domain. Arp5-Ies6 interacts with chromatin via assembly with the INO80 complex, as IES2 and INO80 deletion results in loss of Arp5-Ies6 chromatin association. Interestingly, ectopic addition of the wild-type Arp5-Ies6 module stimulates INO80-mediated ATP hydrolysis and nucleosome sliding in vitro. However, the addition of mutant Arp5 lacking unique insertion domains facilitates ATP hydrolysis in the absence of nucleosome sliding. Collectively, these results define the requirements of Arp5-Ies6 assembly, which are needed to couple ATP hydrolysis to productive nucleosome movement. PMID:26306040

Motor unit recruitment in human genioglossus muscle in response to hypercapnia.

PubMed

Nicholas, Christian L; Bei, Bei; Worsnop, Christopher; Malhotra, Atul; Jordan, Amy S; Saboisky, Julian P; Chan, Julia K M; Duckworth, Ella; White, David P; Trinder, John

2010-11-01

single motor unit recordings of the genioglossus (GG) muscle indicate that GG motor units have a variety of discharge patterns, including units that have higher discharge rates during inspiration (inspiratory phasic and inspiratory tonic), or expiration (expiratory phasic and expiratory tonic), or do not modify their rate with respiration (tonic). Previous studies have shown that an increase in GG muscle activity is a consequence of increased activity in inspiratory units. However, there are differences between studies as to whether this increase is primarily due to recruitment of new motor units (motor unit recruitment) or to increased discharge rate of already active units (rate coding). Sleep-wake state studies in humans have suggested the former, while hypercapnia experiments in rats have suggested the latter. In this study, we investigated the effect of hypercapnia on GG motor unit activity in humans during wakefulness. sleep research laboratory. sixteen healthy men. each participant was administered at least 6 trials with P(et)CO(2) being elevated 8.4 (SD = 1.96) mm Hg over 2 min following a 30-s baseline. Subjects were instrumented for GG EMG and respiratory measurements with 4 fine wire electrodes inserted subcutaneously into the muscle. One hundred forty-one motor units were identified during the baseline: 47% were inspiratory modulated, 29% expiratory modulated, and 24% showed no respiratory related modulation. Sixty-two new units were recruited during hypercapnia. The distribution of recruited units was significantly different from the baseline distribution, with 84% being inspiratory modulated (P < 0.001). Neither units active during baseline, nor new units recruited during hypercapnia, increased their discharge rate as P(et)CO(2) increased (P > 0.05 for all comparisons). increased GG muscle activity in humans occurs because of recruitment of previously inactive inspiratory modulated units.

Software-implemented fault insertion: An FTMP example

NASA Technical Reports Server (NTRS)

Czeck, Edward W.; Siewiorek, Daniel P.; Segall, Zary Z.

1987-01-01

This report presents a model for fault insertion through software; describes its implementation on a fault-tolerant computer, FTMP; presents a summary of fault detection, identification, and reconfiguration data collected with software-implemented fault insertion; and compares the results to hardware fault insertion data. Experimental results show detection time to be a function of time of insertion and system workload. For the fault detection time, there is no correlation between software-inserted faults and hardware-inserted faults; this is because hardware-inserted faults must manifest as errors before detection, whereas software-inserted faults immediately exercise the error detection mechanisms. In summary, the software-implemented fault insertion is able to be used as an evaluation technique for the fault-handling capabilities of a system in fault detection, identification and recovery. Although the software-inserted faults do not map directly to hardware-inserted faults, experiments show software-implemented fault insertion is capable of emulating hardware fault insertion, with greater ease and automation.

Intravenous cannulation of adolescents does not affect the modulation of autonomic tone assessed by heart rate and blood pressure variability.

PubMed

Stewart, J M

2000-02-01

Invasive arterial monitoring alters autonomic tone. The effects of intravenous (i.v.) insertion are less clear. The author assessed the effects of i.v. insertion on autonomic activity in patients aged 11 to 19 years prior to head-up tilt by measuring heart rate, blood pressure, heart rate variability, blood pressure variability, and baroreceptor gain before and after i.v. insertion with continuous electrocardiography and arterial tonometry in patients with orthostatic tachycardia syndrome (OTS, N = 21), in patients who experienced simple fainting (N = 14), and in normal control subjects (N = 6). Five-minute samples were collected after 30 minutes supine. Fifteen minutes after i.v. insertion, data were collected again. These 5-minute samples were also collected in a separate control population without i.v. insertion after 30 minutes supine and again 30 minutes later. This population included 12 patients with OTS, 13 patients who experienced simple fainting, and 6 normal control subjects. Heart rate variability included the mean RR, the standard deviation of the RR interval (SDNN), and the root mean square of successive RR differences (RMSSD). Autoregressive spectral modeling was used. Low-frequency power (LFP, 0.04-0.15 Hz), high-frequency power (HFP, 0.15-0.40 Hz), and total power (TP, 0.01-0.40 Hz) were compared. Blood pressure variability included standard deviation of systolic blood pressure, LFP, and HFP. Baroreceptor gain at low frequency and high frequency was calculated from cross-spectral transfer function magnitudes when coherence was greater than 0.5. In patients with OTS, RR (790 +/- 50 msec), SDNN (54 +/- 6 msec), RMSSD (55 +/- 5 msec), LFP (422 +/- 200 ms2/Hz), HFP (846 +/- 400 ms2/Hz), and TP (1550 +/- 320 ms2/Hz) were less than in patients who experienced simple fainting (RR, 940 +/- 50 msec; SDNN, 84 +/- 10 msec; RMSSD, 91 +/- 7 msec; LFP, 880 +/- 342 ms2/Hz; HFP, 1720 +/- 210 ms2/Hz; and TP, 3228 +/- 490 ms2/Hz) or normal control subjects (RR, 920 +/- 30 msec; SDNN, 110 +/- 29 msec; RMSSD, 120 +/- 16 msec; LFP, 1600 +/- 331 ms2/Hz; HFP, 2700 +/- 526 ms2/Hz; and TP, 5400 +/- 1017 ms2/Hz). Blood pressure and blood pressure variability were not different in any group. Standard deviation, LFP, and HFP were, respectively, 5.24 +/- 0.8 mm Hg, 1.2 +/- 0.2, and 1.5 +/- 0.3 for patients with OTS; 4.6 +/- 0.4 mm Hg, 1.2 +/- 0.2, and 1.4 +/- 0.3 for patients who experienced simple fainting; and 5.55 +/- 1.0 mm Hg, 1.4 +/- 0.2, and 1.6 +/- 0.3 for normal control subjects. Baroreceptor gain at low frequency and high frequency in patients with OTS (16 +/- 4 msec/mm Hg, 17 +/- 5) was comparable to that in patients who experienced simple fainting (33 +/- 4, 32 +/- 3) and that in normal control subjects (31 +/- 8, 37 +/- 9). Heart rate variability differed between patients with OTS and patients who experienced simple fainting or normal control subjects, and blood pressure and blood pressure variability were not different, but no parameter changed after i.v. insertion. There were no differences from the groups that did not receive i.v. insertions. Data suggest, at most, a limited effect of i.v. insertion on autonomic function in adolescents.

Effects on Subtalar Joint Stress Distribution After Cannulated Screw Insertion at Different Positions and Directions.

PubMed

Yuan, Cheng-song; Chen, Wan; Chen, Chen; Yang, Guang-hua; Hu, Chao; Tang, Kang-lai

2015-01-01

We investigated the effects on subtalar joint stress distribution after cannulated screw insertion at different positions and directions. After establishing a 3-dimensional geometric model of a normal subtalar joint, we analyzed the most ideal cannulated screw insertion position and approach for subtalar joint stress distribution and compared the differences in loading stress, antirotary strength, and anti-inversion/eversion strength among lateral-medial antiparallel screw insertion, traditional screw insertion, and ideal cannulated screw insertion. The screw insertion approach allowing the most uniform subtalar joint loading stress distribution was lateral screw insertion near the border of the talar neck plus medial screw insertion close to the ankle joint. For stress distribution uniformity, antirotary strength, and anti-inversion/eversion strength, lateral-medial antiparallel screw insertion was superior to traditional double-screw insertion. Compared with ideal cannulated screw insertion, slightly poorer stress distribution uniformity and better antirotary strength and anti-inversion/eversion strength were observed for lateral-medial antiparallel screw insertion. Traditional single-screw insertion was better than double-screw insertion for stress distribution uniformity but worse for anti-rotary strength and anti-inversion/eversion strength. Lateral-medial antiparallel screw insertion was slightly worse for stress distribution uniformity than was ideal cannulated screw insertion but superior to traditional screw insertion. It was better than both ideal cannulated screw insertion and traditional screw insertion for anti-rotary strength and anti-inversion/eversion strength. Lateral-medial antiparallel screw insertion is an approach with simple localization, convenient operation, and good safety. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Visible CWDM system design for Multi-Gbit/s transmission over SI-POF

NASA Astrophysics Data System (ADS)

Vázquez, Carmen; Pinzón, Plinio Jesús; Pérez, Isabel

2015-01-01

In order to increase the data rates of Multi-Gbit/s links based on large core step index (SI) plastic optical fibers (POF), different modulation scenes have been proposed. Another option is to use multiple optical carriers for parallel transmission of communication channels over the same fiber. Some designs to reach data rates of 14.77 Gb/s in 50 m, with 4 channels have been developed by off line processing. In this work, designs to test the potential of real Multi- Gbit/s transmission systems using commercial products are reported. Special care in designing low insertion loss multiplexers and demultiplexers is carried out to allow for greener solutions in terms of power consumption.

Rotation and neoclassical ripple transport in ITER

DOE PAGES

Paul, Elizabeth Joy; Landreman, Matt; Poli, Francesca M.; ...

2017-07-13

Neoclassical transport in the presence of non-axisymmetric magnetic fields causes a toroidal torque known as neoclassical toroidal viscosity (NTV). The toroidal symmetry of ITER will be broken by the finite number of toroidal field coils and by test blanket modules (TBMs). The addition of ferritic inserts (FIs) will decrease the magnitude of the toroidal field ripple. 3D magnetic equilibria in the presence of toroidal field ripple and ferromagnetic structures are calculated for an ITER steady-state scenario using the Variational Moments Equilibrium Code (VMEC). Furthermore, neoclassical transport quantities in the presence of these error fields are calculated using the Stellarator Fokker-Planckmore » Iterative Neoclassical Conservative Solver (SFINCS).« less

Thermal Design, Analysis, and Testing of the Quench Module Insert Bread Board

NASA Technical Reports Server (NTRS)

Breeding Shawn; Khodabandeh, Julia; Turner, Larry D. (Technical Monitor)

2001-01-01

The science requirements for materials processing is to provide the desired PI requirements of thermal gradient, solid/liquid interface front velocity for a given processing temperature desired by the PI. Processing is performed by translating the furnace with the sample in a stationary position to minimize any disturbances to the solid/liquid interface front during steady state processing. Typical sample materials for this metals and alloys furnace are lead-tin alloys, lead-antimony alloys, and aluminum alloys. Samples must be safe to process and therefore typically are contained with hermetically sealed cartridge tubes (gas tight) with inner ceramic liners (liquid tight) to prevent contamination and/or reaction of the sample material with the cartridge tube.

Inserting ex vivo fluorescence confocal microscopy perioperatively in Mohs micrographic surgery expedites bedside assessment of excision margins in recurrent basal cell carcinoma.

PubMed

Longo, Caterina; Ragazzi, Moira; Castagnetti, Fabio; Gardini, Stefano; Palmieri, Tamara; Lallas, Aimilios; Moscarella, Elvira; Piana, Simonetta; Pellacani, Giovanni; Zalaudek, Iris; Argenziano, Giuseppe

2013-01-01

Mohs micrographic surgery can be employed in recurrent basal cell carcinoma, although it is a time-consuming technique. Recently, ex vivo fluorescence confocal microscopy (FCM) has been employed to obtain a fast assessment of tumor margins at the bedside. In our case we successfully employed ex vivo FCM to assess the tumor margins and we treated the persistent tumor with intensity-modulated radiation therapy. Our case demonstrates that a multidisciplinary approach is very efficient in managing complex and recurrent tumors and highlights the benefits of FCM as a new technique that can be used in the surgical theater to speed up the entire procedure.

A fractional approach to the Fermi-Pasta-Ulam problem

NASA Astrophysics Data System (ADS)

Machado, J. A. T.

2013-09-01

This paper studies the Fermi-Pasta-Ulam problem having in mind the generalization provided by Fractional Calculus (FC). The study starts by addressing the classical formulation, based on the standard integer order differential calculus and evaluates the time and frequency responses. A first generalization to be investigated consists in the direct replacement of the springs by fractional elements of the dissipative type. It is observed that the responses settle rapidly and no relevant phenomena occur. A second approach consists of replacing the springs by a blend of energy extracting and energy inserting elements of symmetrical fractional order with amplitude modulated by quadratic terms. The numerical results reveal a response close to chaotic behaviour.

Three-Dimensional Large Screen Display Using Polymer-Dispersed Liquid-Crystal Light Valves and a Schlieren Optical System: Proposal and Basic Experiments

NASA Astrophysics Data System (ADS)

Takizawa, Kuniharu

A novel three-dimensional (3-D) projection display used with polarized eyeglasses is proposed. It consists of polymer-dispersed liquid crystal-light valves that modulate the illuminated light based on light scattering, a polarization beam splitter, and a Schlieren projection system. The features of the proposed display include a 3-D image display with a single projector, half size and half power consumption compared with a conventional 3-D projector with polarized glasses. Measured electro-optic characteristics of a polymer-dispersed liquid-crystal cell inserted between crossed polarizers suggests that the proposed display achieves small cross talk and high-extinction ratio.

A practical topological insulator saturable absorber for mode-locked fiber laser

PubMed Central

Yan, Peiguang; Lin, Rongyong; Ruan, Shuangchen; Liu, Aijiang; Chen, Hao; Zheng, Yuequn; Chen, Sifan; Guo, Chunyu; Hu, Juguang

2015-01-01

A novel saturable absorber (SA) was fabricated by coating the topological insulator (TI) film on microfiber using pulsed laser deposition (PLD) method. The TISA device had an insertion loss of ~1.25 dB, a saturable intensity of 26.7 MW/cm2, a modulation depth of ~5.7%, and a nonsaturable loss of 20.5%. Upon employing this SA device, we established a passively mode-locked EDFL and achieved nearly free-chirped soliton pulse with 286 fs of pulse duration and >73 dB of signal to noise ratio (SNR). This result clearly evidences that the PLD is an effective scheme for practical SA device fabrication. PMID:25732598

Rotation and neoclassical ripple transport in ITER

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

Paul, Elizabeth Joy; Landreman, Matt; Poli, Francesca M.

Neoclassical transport in the presence of non-axisymmetric magnetic fields causes a toroidal torque known as neoclassical toroidal viscosity (NTV). The toroidal symmetry of ITER will be broken by the finite number of toroidal field coils and by test blanket modules (TBMs). The addition of ferritic inserts (FIs) will decrease the magnitude of the toroidal field ripple. 3D magnetic equilibria in the presence of toroidal field ripple and ferromagnetic structures are calculated for an ITER steady-state scenario using the Variational Moments Equilibrium Code (VMEC). Furthermore, neoclassical transport quantities in the presence of these error fields are calculated using the Stellarator Fokker-Planckmore » Iterative Neoclassical Conservative Solver (SFINCS).« less

[The future of telepathology. An Internet "distributed system" with "open standards"].

PubMed

Brauchli, K; Helfrich, M; Christen, H; Jundt, G; Haroske, G; Mihatsch, M; Oberli, H; Oberholzer, M

2002-05-01

With the availability of Internet, the interest in the possibilities of telepathology has increased considerably. In the foreground is thereby the need of the non-expert to bring in the opinions of experts on morphological findings by means of a fast and simple procedure. The new telepathology system iPath is in compliance with these needs. The system is based on small, but when possible independently working modules. This concept allows a simple adaptation of the system to the individual environment of the user (e.g. for different cameras, frame-grabbers, microscope steering tables etc.) and for individual needs. iPath has been in use for 6 months with various working groups. In telepathology a distinction is made between "passive" and "active" consultations but for both forms a non-expert brings in the opinion of an expert. In an active consultation both are in direct connection with each other (orally or via a chat-function), this is however not the case with a passive consultation. An active consultation can include the interactive discussion of the expert with the non-expert on images in an image database or the direct interpretation of images from a microscope by the expert. Four software modules are available for a free and as fast as possible application: (1) the module "Microscope control", (2) the module "Connector" (insertion of images directly from the microscope without a motorized microscope), (3) the module "Client-application" via the web-browser and (4) the module "Server" with a database. The server is placed in the internet and not behind a firewall. The server permanently receives information from the periphery and returns the information to the periphery on request. The only thing which the expert, the non-expert and the microscope have to know is how contact can made with the server.

Electrophysiological and structural determinants of electrotonic modulation of repolarization by the activation sequence

PubMed Central

Walton, Richard D.; Benson, Alan P.; Hardy, Matthew E. L.; White, Ed; Bernus, Olivier

2013-01-01

Spatial dispersion of repolarization is known to play an important role in arrhythmogenesis. Electrotonic modulation of repolarization by the activation sequence has been observed in some species and tissue preparations, but to varying extents. Our study sought to determine the mechanisms underlying species- and tissue-dependent electrotonic modulation of repolarization in ventricles. Epi-fluorescence optical imaging of whole rat hearts and pig left ventricular wedges were used to assess epicardial spatial activation and repolarization characteristics. Experiments were supported by computer simulations using realistic geometries. Tight coupling between activation times (AT) and action potential duration (APD) were observed in rat experiments but not in pig. Linear correlation analysis found slopes of −1.03 ± 0.59 and −0.26 ± 0.13 for rat and pig, respectively (p < 0.0001). In rat, maximal dispersion of APD was 11.0 ± 3.1 ms but dispersion of repolarization time (RT) was relatively homogeneous (8.2 ± 2.7, p < 0.0001). However, in pig no such difference was observed between the dispersion of APD and RT (17.8 ± 6.1 vs. 17.7 ± 6.5, respectively). Localized elevations of APD (12.9 ± 8.3%) were identified at ventricular insertion sites of rat hearts both in experiments and simulations. Tissue geometry and action potential (AP) morphology contributed significantly to determining influence of electrotonic modulation. Simulations of a rat AP in a pig geometry decreased the slope of AT and APD relationships by 70.6% whereas slopes were increased by 75.0% when implementing a pig AP in a rat geometry. A modified pig AP, shortened to match the rat APD, showed little coupling between AT and APD with greatly reduced slope compared to the rat AP. Electrotonic modulation of repolarization by the activation sequence is especially pronounced in small hearts with murine-like APs. Tissue architecture and AP morphology play an important role in electrotonic modulation of repolarization. PMID:24115934

Two potential calmodulin-binding sequences in the ryanodine receptor contribute to a mobile, intra-subunit calmodulin-binding domain

PubMed Central

Huang, Xiaojun; Liu, Ying; Wang, Ruiwu; Zhong, Xiaowei; Liu, Yingjie; Koop, Andrea; Chen, S. R. Wayne; Wagenknecht, Terence; Liu, Zheng

2013-01-01

Summary Calmodulin (CaM), a 16 kDa ubiquitous calcium-sensing protein, is known to bind tightly to the calcium release channel/ryanodine receptor (RyR), and modulate RyR function. CaM binding studies using RyR fragments or synthetic peptides have revealed the presence of multiple, potential CaM-binding regions in the primary sequence of RyR. In the present study, we inserted GFP into two of these proposed CaM-binding sequences and mapped them onto the three-dimensional structure of intact cardiac RyR2 by cryo-electron microscopy. Interestingly, we found that the two potential CaM-binding regions encompassing, Arg3595 and Lys4269, respectively, are in close proximity and are adjacent to the previously mapped CaM-binding sites. To monitor the conformational dynamics of these CaM-binding regions, we generated a fluorescence resonance energy transfer (FRET) pair, a dual CFP- and YFP-labeled RyR2 (RyR2R3595-CFP/K4269-YFP) with CFP inserted after Arg3595 and YFP inserted after Lys4269. We transfected HEK293 cells with the RyR2R3595-CFP/K4269-YFP cDNA, and examined their FRET signal in live cells. We detected significant FRET signals in transfected cells that are sensitive to the channel activator caffeine, suggesting that caffeine is able to induce conformational changes in these CaM-binding regions. Importantly, no significant FRET signals were detected in cells co-transfected with cDNAs encoding the single CFP (RyR2R3595-CFP) and single YFP (RyR2K4269-YFP) insertions, indicating that the FRET signal stemmed from the interaction between R3595–CFP and K4269–YFP that are in the same RyR subunit. These observations suggest that multiple regions in the RyR2 sequence may contribute to an intra-subunit CaM-binding pocket that undergoes conformational changes during channel gating. PMID:23868982

Athermalization of infrared dual field optical system based on wavefront coding

NASA Astrophysics Data System (ADS)

Jiang, Kai; Jiang, Bo; Liu, Kai; Yan, Peipei; Duan, Jing; Shan, Qiu-sha

2017-02-01

Wavefront coding is a technology which combination of the optical design and digital image processing. By inserting a phase mask closed to the pupil plane of the optical system the wavefront of the system is re-modulated. And the depth of focus is extended consequently. In reality the idea is same as the athermalization theory of infrared optical system. In this paper, an uncooled infrared dual field optical system with effective focal as 38mm/19mm, F number as 1.2 of both focal length, operating wavelength varying from 8μm to 12μm was designed. A cubic phase mask was used at the pupil plane to re-modulate the wavefront. Then the performance of the infrared system was simulated with CODEV as the environment temperature varying from -40° to 60°. MTF curve of the optical system with phase mask are compared with the outcome before using phase mask. The result show that wavefront coding technology can make the system not sensitive to thermal defocus, and then realize the athermal design of the infrared optical system.

3D active edge silicon sensors: Device processing, yield and QA for the ATLAS-IBL production

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

Da Vià, Cinzia; Boscardil, Maurizio; Dalla Betta, GianFranco

2013-01-01

3D silicon sensors, where plasma micromachining is used to etch deep narrow apertures in the silicon substrate to form electrodes of PIN junctions, were successfully manufactured in facilities in Europe and USA. In 2011 the technology underwent a qualification process to establish its maturity for a medium scale production for the construction of a pixel layer for vertex detection, the Insertable B-Layer (IBL) at the CERN-LHC ATLAS experiment. The IBL collaboration, following that recommendation from the review panel, decided to complete the production of planar and 3D sensors and endorsed the proposal to build enough modules for a mixed IBLmore » sensor scenario where 25% of 3D modules populate the forward and backward part of each stave. The production of planar sensors will also allow coverage of 100% of the IBL, in case that option was required. This paper will describe the processing strategy which allowed successful 3D sensor production, some of the Quality Assurance (QA) tests performed during the pre-production phase and the production yield to date.« less

Genetic and nutrient modulation of acetyl-CoA levels in Synechocystis for n-butanol production.

PubMed

Anfelt, Josefine; Kaczmarzyk, Danuta; Shabestary, Kiyan; Renberg, Björn; Rockberg, Johan; Nielsen, Jens; Uhlén, Mathias; Hudson, Elton P

2015-10-16

There is a strong interest in using photosynthetic cyanobacteria as production hosts for biofuels and chemicals. Recent work has shown the benefit of pathway engineering, enzyme tolerance, and co-factor usage for improving yields of fermentation products. An n-butanol pathway was inserted into a Synechocystis mutant deficient in polyhydroxybutyrate synthesis. We found that nitrogen starvation increased specific butanol productivity up to threefold, but cessation of cell growth limited total n-butanol titers. Metabolite profiling showed that acetyl-CoA increased twofold during nitrogen starvation. Introduction of a phosphoketolase increased acetyl-CoA levels sixfold at nitrogen replete conditions and increased butanol titers from 22 to 37 mg/L at day 8. Flux balance analysis of photoautotrophic metabolism showed that a Calvin-Benson-Bassham-Phosphoketolase pathway had higher theoretical butanol productivity than CBB-Embden-Meyerhof-Parnas and a reduced butanol ATP demand. These results demonstrate that phosphoketolase overexpression and modulation of nitrogen levels are two attractive routes toward increased production of acetyl-CoA derived products in cyanobacteria and could be implemented with complementary metabolic engineering strategies.

High-resolution mapping, characterization, and optimization of autonomously replicating sequences in yeast

PubMed Central

Liachko, Ivan; Youngblood, Rachel A.; Keich, Uri; Dunham, Maitreya J.

2013-01-01

DNA replication origins are necessary for the duplication of genomes. In addition, plasmid-based expression systems require DNA replication origins to maintain plasmids efficiently. The yeast autonomously replicating sequence (ARS) assay has been a valuable tool in dissecting replication origin structure and function. However, the dearth of information on origins in diverse yeasts limits the availability of efficient replication origin modules to only a handful of species and restricts our understanding of origin function and evolution. To enable rapid study of origins, we have developed a sequencing-based suite of methods for comprehensively mapping and characterizing ARSs within a yeast genome. Our approach finely maps genomic inserts capable of supporting plasmid replication and uses massively parallel deep mutational scanning to define molecular determinants of ARS function with single-nucleotide resolution. In addition to providing unprecedented detail into origin structure, our data have allowed us to design short, synthetic DNA sequences that retain maximal ARS function. These methods can be readily applied to understand and modulate ARS function in diverse systems. PMID:23241746

Conditional genomic rearrangement by designed meiotic recombination using VDE (PI-SceI) in yeast.

PubMed

Fukuda, Tomoyuki; Ohya, Yoshikazu; Ohta, Kunihiro

2007-10-01

Meiotic recombination plays critical roles in the acquisition of genetic diversity and has been utilized for conventional breeding of livestock and crops. The frequency of meiotic recombination is normally low, and is extremely low in regions called "recombination cold domains". Here, we describe a new and highly efficient method to modulate yeast meiotic gene rearrangements using VDE (PI-SceI), an intein-encoded endonuclease that causes an efficient unidirectional meiotic gene conversion at its recognition sequence (VRS). We designed universal targeting vectors, by use of which the strain that inserts the VRS at a desired site is acquired. Meiotic induction of the strains provided unidirectional gene conversions and frequent genetic rearrangements of flanking genes with little impact on cell viability. This system thus opens the way for the designed modulation of meiotic gene rearrangements, regardless of recombinational activity of chromosomal domains. Finally, the VDE-VRS system enabled us to conduct meiosis-specific conditional knockout of genes where VDE-initiated gene conversion disrupts the target gene during meiosis, serving as a novel approach to examine the functions of genes during germination of resultant spores.

Monolithically integrated quantum dot optical modulator with semiconductor optical amplifier for thousand and original band optical communication

NASA Astrophysics Data System (ADS)

Yamamoto, Naokatsu; Akahane, Kouichi; Umezawa, Toshimasa; Matsumoto, Atsushi; Kawanishi, Tetsuya

2016-04-01

A monolithically integrated quantum dot (QD) optical gain modulator (OGM) with a QD semiconductor optical amplifier (SOA) was successfully developed with T-band (1.0 µm waveband) and O-band (1.3 µm waveband) QD optical gain materials for Gbps-order, high-speed optical data generation. The insertion loss due to coupling between the device and the optical fiber was effectively compensated for by the SOA section. It was also confirmed that the monolithic QD-OGM/SOA device enabled >4.8 Gbps optical data generation with a clear eye opening in the T-band. Furthermore, we successfully demonstrated error-free 4.8 Gbps optical data transmissions in each of the six wavelength channels over a 10-km-long photonic crystal fiber using the monolithic QD-OGM/SOA device in multiple O-band wavelength channels, which were generated by the single QD gain chip. These results suggest that the monolithic QD-OGM/SOA device will be advantageous in ultra-broadband optical frequency systems that utilize the T+O-band for short- and medium-range optical communications.

Design and Lessons Learned on the Development of a Cryogenic Pupil Select Mechanism used in the Testing and Calibration of the Integrated Science Instrument Module (ISIM) on the James Webb Space Telescope (JWST)

NASA Technical Reports Server (NTRS)

Mitchell, Alissa; Capon, Thomas; Guzek, Jeffrey; Hakun, Claef; Haney, Paul; Koca, Corina

2014-01-01

Calibration and testing of the instruments on the Integrated Science Instrument Module (ISIM) of the James Webb Space Telescope (JWST) is being performed by the use of a cryogenic, full-field, optical simulator that was constructed for this purpose. The Pupil Select Mechanism (PSM) assembly is one of several mechanisms and optical elements that compose the Optical Telescope Element SIMulator, or OSIM. The PSM allows for several optical elements to be inserted into the optical plane of OSIM, introducing a variety of aberrations, distortions, obscurations, and other calibration states into the pupil plane. The following discussion focuses on the details of the design evolution, analysis, build, and test of this mechanism along with the challenges associated with creating a sub arc-minute positioning mechanism operating in an extreme cryogenic environment. In addition, difficult challenges in the control system design will be discussed including the incorporation of closed-loop feedback control into a system that was designed to operate in an open-loop fashion.

Design and Lessons Learned on the Development of a Cryogenic Pupil Select Mechanism Used in the Testing and Calibration of the Integrated Science Instrument Module (ISIM) on the James Webb Space Telescope (JWST)

NASA Technical Reports Server (NTRS)

Mitchell, Alissa; Capon, Thomas; Guzek, Jeffrey; Hakun, Claef; Haney, Paul; Koca, Corina

2014-01-01

Calibration and testing of the instruments on the Integrated Science Instrument Module (ISIM) of the James Webb Space Telescope (JWST) is being performed by the use of a cryogenic, full-field, optical simulator that was constructed for this purpose. The Pupil Select Mechanism (PSM) assembly is one of several mechanisms and optical elements that compose the Optical Telescope Element SIMulator, or OSIM. The PSM allows for several optical elements to be inserted into the optical plane of OSIM, introducing a variety of aberrations, distortions, obscurations, and other calibration states into the pupil plane. The following discussion focuses on the details of the design evolution, analysis, build, and test of this mechanism along with the challenges associated with creating a sub arc-minute positioning mechanism operating in an extreme cryogenic environment. In addition, difficult challenges in the control system design will be discussed including the incorporation of closed-loop feedback control into a system that was designed to operate in an open-loop fashion.

A LAMMPS implementation of volume-temperature replica exchange molecular dynamics

NASA Astrophysics Data System (ADS)

Liu, Liang-Chun; Kuo, Jer-Lai

2015-04-01

A driver module for executing volume-temperature replica exchange molecular dynamics (VTREMD) was developed for the LAMMPS package. As a patch code, the VTREMD module performs classical molecular dynamics (MD) with Monte Carlo (MC) decisions between MD runs. The goal of inserting the MC step was to increase the breadth of sampled configurational space. In this method, states receive better sampling by making temperature or density swaps with their neighboring states. As an accelerated sampling method, VTREMD is particularly useful to explore states at low temperatures, where systems are easily trapped in local potential wells. As functional examples, TIP4P/Ew and TIP4P/2005 water models were analyzed using VTREMD. The phase diagram in this study covered the deeply supercooled regime, and this test served as a suitable demonstration of the usefulness of VTREMD in overcoming the slow dynamics problem. To facilitate using the current code, attention was also paid on how to optimize the exchange efficiency by using grid allocation. VTREMD was useful for studying systems with rough energy landscapes, such as those with numerous local minima or multiple characteristic time scales.

[Accuracy of Modulation Transfer Function for Target Size and Field of View in a Circular Edge Strategy Using the CT Image Measurement Program].

PubMed

Fukunaga, Masaaki; Onishi, Hideo; Matsutomo, Norikazu; Yamamoto, Hiroyuki

2016-06-01

The purpose of this study was to evaluate the effects of target diameter and display-field of view (D-FOV) in modulation transfer function (MTF) by circular edge strategy using the computed tomography (CT) image measurement program "CTmeasure". We calculated the MTF (MTF(edge)) using the circular edge strategy applied to cylindrical phantom (200 mmφ) that inserted with cylinders have 10, 20, 30, and 40 mm diameters. The phantom images were reconstructed using filtered back projection method varied with D-FOV (240, 320, 400, and 500 mm). The study compared both MTF(edge) and MTF(wire) at MTF50% and MTF(10%) for target diameter and D-FOV, respectively. The MTF(edge) by the different of target diameter indicated in rough compatibility. However, MTF(edge) of D-FOV diameters (320, 400, and 500 mm) decreased in the high frequency range. The circular edge strategy for MTF depended on the D-FOV, however, it was little dependent on target diameter using the CT image measurement program "CTmeasure".

Independent Orbiter Assessment (IOA): Analysis of the reaction control system, volume 1

NASA Technical Reports Server (NTRS)

Burkemper, V. J.; Haufler, W. A.; Odonnell, R. A.; Paul, D. J.

1987-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results for the Reaction Control System (RCS). The purpose of the RCS is to provide thrust in and about the X, Y, Z axes for External Tank (ET) separation; orbit insertion maneuvers; orbit translation maneuvers; on-orbit attitude control; rendezvous; proximity operations (payload deploy and capture); deorbit maneuvers; and abort attitude control. The RCS is situated in three independent modules, one forward in the orbiter nose and one in each OMS/RCS pod. Each RCS module consists of the following subsystems: Helium Pressurization Subsystem; Propellant Storage and Distribution Subsystem; Thruster Subsystem; and Electrical Power Distribution and Control Subsystem. Of the failure modes analyzed, 307 could potentially result in a loss of life and/or loss of vehicle.

Atomic clocks based on extened-cavity diode laser in multimode operation

NASA Astrophysics Data System (ADS)

Yim, Sin; Cho, D.

2011-05-01

We demonstrated the possibilities to develope an atomic clock based on coherent population trapping (CPT) without using a local oscillator and a modulator. Instead of using a modulator, we use two modes from a single extended-cavity diode laser in multimode operation. Two different types of feedback system are applied to stabilize a difference frequency between the two modes and eliminate the need for an extra frequency modulation. In the first type, we employ an electronic feedback using dispersion of the CPT resonance as an error signal. The two modes are phase locked with reference to a dispersion signal from a CPT resonance of 85Rb at 3.036 GHz ground hyperfine splitting. We use D1 transition at 794.8 nm with lin ⊥lin polarizations to obtain large-contrast CPT signal. Allan deviation of the beat frequency between the two modes is 1 ×10-10 at 200-s integration time. In the second type, we employ optoelectronic feedback to construct an opto-electronic oscillator (OEO). In an OEO, the beating signal between two modes is recovered by a fast photodiode, and its output is amplified and fed back to the laser diode by using a direct modulation of an injection current. When the OEO loop is closed, oscillation frequency depends on variations of the loop length. In order to stabilize an OEO loop length and thereby its oscillation frequency, CPT cell is inserted to play a role of microwave band pass filter. Allan deviation of the CPT-stabilized OEO is 2 ×10-10 at 100-s integration time.

Sleep/wake firing patterns of human genioglossus motor units.

PubMed

Bailey, E Fiona; Fridel, Keith W; Rice, Amber D

2007-12-01

Although studies of the principal tongue protrudor muscle genioglossus (GG) suggest that whole muscle GG electromyographic (EMG) activities are preserved in nonrapid eye movement (NREM) sleep, it is unclear what influence sleep exerts on individual GG motor unit (MU) activities. We characterized the firing patterns of human GG MUs in wakefulness and NREM sleep with the aim of determining 1) whether the range of MU discharge patterns evident in wakefulness is preserved in sleep and 2) what effect the removal of the "wakefulness" input has on the magnitude of the respiratory modulation of MU activities. Microelectrodes inserted into the extrinsic tongue protrudor muscle, the genioglossus, were used to follow the discharge of single MUs. We categorized MU activities on the basis of the temporal relationship between the spike train and the respiration cycle and quantified the magnitude of the respiratory modulation of each MU using the eta (eta(2)) index, in wakefulness and sleep. The majority of MUs exhibited subtle increases or decreases in respiratory modulation but were otherwise unaffected by NREM sleep. In contrast, 30% of MUs exhibited marked sleep-associated changes in discharge frequency and respiratory modulation. We suggest that GG MUs should not be considered exclusively tonic or phasic; rather, the discharge pattern appears to be a flexible feature of GG activities in healthy young adults. Whether such flexibility is important in the response to changes in the chemical and/or mechanical environment and whether it is preserved as a function of aging or in individuals with obstructive sleep apnea are critical questions for future research.

A Natural Chimeric Pseudomonas Bacteriocin with Novel Pore-Forming Activity Parasitizes the Ferrichrome Transporter

PubMed Central

Kemland, Lieselore; Anoz-Carbonell, Ernesto; Buchanan, Susan K.; De Mot, René

2017-01-01

ABSTRACT Modular bacteriocins represent a major group of secreted protein toxins with a narrow spectrum of activity, involved in interference competition between Gram-negative bacteria. These antibacterial proteins include a domain for binding to the target cell and a toxin module at the carboxy terminus. Self-inhibition of producers is provided by coexpression of linked immunity genes that transiently inhibit the toxin’s activity through formation of bacteriocin-immunity complexes or by insertion in the inner membrane, depending on the type of toxin module. We demonstrate strain-specific inhibitory activity for PmnH, a Pseudomonas bacteriocin with an unprecedented dual-toxin architecture, hosting both a colicin M domain, potentially interfering with peptidoglycan synthesis, and a novel colicin N-type domain, a pore-forming module distinct from the colicin Ia-type domain in Pseudomonas aeruginosa pyocin S5. A downstream-linked gene product confers PmnH immunity upon susceptible strains. This protein, ImnH, has a transmembrane topology similar to that of Pseudomonas colicin M-like and pore-forming immunity proteins, although homology with either of these is essentially absent. The enhanced killing activity of PmnH under iron-limited growth conditions reflects parasitism of the ferrichrome-type transporter for entry into target cells, a strategy shown here to be used as well by monodomain colicin M-like bacteriocins from pseudomonads. The integration of a second type of toxin module in a bacteriocin gene could offer a competitive advantage against bacteria displaying immunity against only one of both toxic activities. PMID:28223456

Early Strains of Multidrug-Resistant Salmonella enterica Serovar Kentucky Sequence Type 198 from Southeast Asia Harbor Salmonella Genomic Island 1-J Variants with a Novel Insertion Sequence

PubMed Central

Le Hello, Simon; Weill, François-Xavier; Guibert, Véronique; Praud, Karine; Cloeckaert, Axel

2012-01-01

Salmonella genomic island 1 (SGI1) is a 43-kb integrative mobilizable element that harbors a great diversity of multidrug resistance gene clusters described in numerous Salmonella enterica serovars and also in Proteus mirabilis. The majority of SGI1 variants contain an In104-derivative complex class 1 integron inserted between resolvase gene res and open reading frame (ORF) S044 in SGI1. Recently, the international spread of ciprofloxacin-resistant S. enterica serovar Kentucky sequence type 198 (ST198) containing SGI1-K variants has been reported. A retrospective study was undertaken to characterize ST198 S. Kentucky strains isolated before the spread of the epidemic ST198-SGI1-K population in Africa and the Middle East. Here, we characterized 12 ST198 S. Kentucky strains isolated between 1969 and 1999, mainly from humans returning from Southeast Asia (n = 10 strains) or Israel (n = 1 strain) or from meat in Egypt (n = 1 strain). All these ST198 S. Kentucky strains did not belong to the XbaI pulsotype X1 associated with the African epidemic clone but to pulsotype X2. SGI1-J subgroup variants containing different complex integrons with a partial transposition module and inserted within ORF S023 of SGI1 were detected in six strains. The SGI1-J4 variant containing a partially deleted class 1 integron and thus showing a narrow resistance phenotype to sulfonamides was identified in two epidemiologically unrelated strains from Indonesia. The four remaining strains harbored a novel SGI1-J variant, named SGI1-J6, which contained aadA2, floR2, tetR(G)-tetA(G), and sul1 resistance genes within its complex integron. Moreover, in all these S. Kentucky isolates, a novel insertion sequence related to the IS630 family and named ISSen5 was found inserted upstream of the SGI1 complex integron in ORF S023. Thus, two subpopulations of S. Kentucky ST198 independently and exclusively acquired the SGI1 during the 1980s and 1990s. Unlike the ST198-X1 African epidemic subpopulation, the ST198-X2 subpopulation mainly from Asia harbors variants of the SGI1-J subgroup that are encountered mainly in the Far East, as previously described for S. enterica serovars Emek and Virchow. PMID:22802251

Early strains of multidrug-resistant Salmonella enterica serovar Kentucky sequence type 198 from Southeast Asia harbor Salmonella genomic island 1-J variants with a novel insertion sequence.

PubMed

Le Hello, Simon; Weill, François-Xavier; Guibert, Véronique; Praud, Karine; Cloeckaert, Axel; Doublet, Benoît

2012-10-01

Salmonella genomic island 1 (SGI1) is a 43-kb integrative mobilizable element that harbors a great diversity of multidrug resistance gene clusters described in numerous Salmonella enterica serovars and also in Proteus mirabilis. The majority of SGI1 variants contain an In104-derivative complex class 1 integron inserted between resolvase gene res and open reading frame (ORF) S044 in SGI1. Recently, the international spread of ciprofloxacin-resistant S. enterica serovar Kentucky sequence type 198 (ST198) containing SGI1-K variants has been reported. A retrospective study was undertaken to characterize ST198 S. Kentucky strains isolated before the spread of the epidemic ST198-SGI1-K population in Africa and the Middle East. Here, we characterized 12 ST198 S. Kentucky strains isolated between 1969 and 1999, mainly from humans returning from Southeast Asia (n = 10 strains) or Israel (n = 1 strain) or from meat in Egypt (n = 1 strain). All these ST198 S. Kentucky strains did not belong to the XbaI pulsotype X1 associated with the African epidemic clone but to pulsotype X2. SGI1-J subgroup variants containing different complex integrons with a partial transposition module and inserted within ORF S023 of SGI1 were detected in six strains. The SGI1-J4 variant containing a partially deleted class 1 integron and thus showing a narrow resistance phenotype to sulfonamides was identified in two epidemiologically unrelated strains from Indonesia. The four remaining strains harbored a novel SGI1-J variant, named SGI1-J6, which contained aadA2, floR2, tetR(G)-tetA(G), and sul1 resistance genes within its complex integron. Moreover, in all these S. Kentucky isolates, a novel insertion sequence related to the IS630 family and named ISSen5 was found inserted upstream of the SGI1 complex integron in ORF S023. Thus, two subpopulations of S. Kentucky ST198 independently and exclusively acquired the SGI1 during the 1980s and 1990s. Unlike the ST198-X1 African epidemic subpopulation, the ST198-X2 subpopulation mainly from Asia harbors variants of the SGI1-J subgroup that are encountered mainly in the Far East, as previously described for S. enterica serovars Emek and Virchow.

The NH2 terminus regulates voltage-dependent gating of CALHM ion channels.

PubMed

Tanis, Jessica E; Ma, Zhongming; Foskett, J Kevin

2017-08-01

Calcium homeostasis modulator protein-1 (CALHM1) and its Caenorhabditis elegans (ce) homolog, CLHM-1, belong to a new family of physiologically important ion channels that are regulated by voltage and extracellular Ca 2+ (Ca 2+ o ) but lack a canonical voltage-sensing domain. Consequently, the intrinsic voltage-dependent gating mechanisms for CALHM channels are unknown. Here, we performed voltage-clamp experiments on ceCLHM-1 chimeric, deletion, insertion, and point mutants to assess the role of the NH 2 terminus (NT) in CALHM channel gating. Analyses of chimeric channels in which the ceCLHM-1 and human (h)CALHM1 NH 2 termini were interchanged showed that the hCALHM1 NT destabilized channel-closed states, whereas the ceCLHM-1 NT had a stabilizing effect. In the absence of Ca 2+ o , deletion of up to eight amino acids from the ceCLHM-1 NT caused a hyperpolarizing shift in the conductance-voltage relationship with little effect on voltage-dependent slope. However, deletion of nine or more amino acids decreased voltage dependence and induced a residual conductance at hyperpolarized voltages. Insertion of amino acids into the NH 2 -terminal helix also decreased voltage dependence but did not prevent channel closure. Mutation of ceCLHM-1 valine 9 and glutamine 13 altered half-maximal activation and voltage dependence, respectively, in 0 Ca 2+ In 2 mM Ca 2+ o , ceCLHM-1 NH 2 -terminal deletion and point mutant channels closed completely at hyperpolarized voltages with apparent affinity for Ca 2+ o indistinguishable from wild-type ceCLHM-1, although the ceCLHM-1 valine 9 mutant exhibited an altered conductance-voltage relationship and kinetics. We conclude that the NT plays critical roles modulating voltage dependence and stabilizing the closed states of CALHM channels. Copyright © 2017 the American Physiological Society.

Novel Burkholderia mallei Virulence Factors Linked to Specific Host-Pathogen Protein Interactions*

PubMed Central

Memišević, Vesna; Zavaljevski, Nela; Pieper, Rembert; Rajagopala, Seesandra V.; Kwon, Keehwan; Townsend, Katherine; Yu, Chenggang; Yu, Xueping; DeShazer, David; Reifman, Jaques; Wallqvist, Anders

2013-01-01

Burkholderia mallei is an infectious intracellular pathogen whose virulence and resistance to antibiotics makes it a potential bioterrorism agent. Given its genetic origin as a commensal soil organism, it is equipped with an extensive and varied set of adapted mechanisms to cope with and modulate host-cell environments. One essential virulence mechanism constitutes the specialized secretion systems that are designed to penetrate host-cell membranes and insert pathogen proteins directly into the host cell's cytosol. However, the secretion systems' proteins and, in particular, their host targets are largely uncharacterized. Here, we used a combined in silico, in vitro, and in vivo approach to identify B. mallei proteins required for pathogenicity. We used bioinformatics tools, including orthology detection and ab initio predictions of secretion system proteins, as well as published experimental Burkholderia data to initially select a small number of proteins as putative virulence factors. We then used yeast two-hybrid assays against normalized whole human and whole murine proteome libraries to detect and identify interactions among each of these bacterial proteins and host proteins. Analysis of such interactions provided both verification of known virulence factors and identification of three new putative virulence proteins. We successfully created insertion mutants for each of these three proteins using the virulent B. mallei ATCC 23344 strain. We exposed BALB/c mice to mutant strains and the wild-type strain in an aerosol challenge model using lethal B. mallei doses. In each set of experiments, mice exposed to mutant strains survived for the 21-day duration of the experiment, whereas mice exposed to the wild-type strain rapidly died. Given their in vivo role in pathogenicity, and based on the yeast two-hybrid interaction data, these results point to the importance of these pathogen proteins in modulating host ubiquitination pathways, phagosomal escape, and actin-cytoskeleton rearrangement processes. PMID:23800426

Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 with improved proof-reading enhances homology-directed repair.

PubMed

Kato-Inui, Tomoko; Takahashi, Gou; Hsu, Szuyin; Miyaoka, Yuichiro

2018-05-18

Genome editing using clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) predominantly induces non-homologous end joining (NHEJ), which generates random insertions or deletions, whereas homology-directed repair (HDR), which generates precise recombination products, is useful for wider applications. However, the factors that determine the ratio of HDR to NHEJ products after CRISPR/Cas9 editing remain unclear, and methods by which the proportion of HDR products can be increased have not yet been fully established. We systematically analyzed the HDR and NHEJ products after genome editing using various modified guide RNAs (gRNAs) and Cas9 variants with an enhanced conformational checkpoint to improve the fidelity at endogenous gene loci in HEK293T cells and HeLa cells. We found that these modified gRNAs and Cas9 variants were able to enhance HDR in both single-nucleotide substitutions and a multi-kb DNA fragment insertion. Our results suggest that the original CRISPR/Cas9 system from the bacterial immune system is not necessarily the best option for the induction of HDR in genome editing and indicate that the modulation of the kinetics of conformational checkpoints of Cas9 can optimize the HDR/NHEJ ratio.

Genes on a Wire: The Nucleoid-Associated Protein HU Insulates Transcription Units in Escherichia coli

PubMed Central

Berger, Michael; Gerganova, Veneta; Berger, Petya; Rapiteanu, Radu; Lisicovas, Viktoras; Dobrindt, Ulrich

2016-01-01

The extent to which chromosomal gene position in prokaryotes affects local gene expression remains an open question. Several studies have shown that chromosomal re-positioning of bacterial transcription units does not alter their expression pattern, except for a general decrease in gene expression levels from chromosomal origin to terminus proximal positions, which is believed to result from gene dosage effects. Surprisingly, the question as to whether this chromosomal context independence is a cis encoded property of a bacterial transcription unit, or if position independence is a property conferred by factors acting in trans, has not been addressed so far. For this purpose, we established a genetic test system assessing the chromosomal positioning effects by means of identical promoter-fluorescent reporter gene fusions inserted equidistantly from OriC into both chromosomal replichores of Escherichia coli K-12. Our investigations of the reporter activities in mutant cells lacking the conserved nucleoid associated protein HU uncovered various drastic chromosomal positional effects on gene transcription. In addition we present evidence that these positional effects are caused by transcriptional activity nearby the insertion site of our reporter modules. We therefore suggest that the nucleoid-associated protein HU is functionally insulating transcription units, most likely by constraining transcription induced DNA supercoiling. PMID:27545593

The OsPS1-F gene regulates growth and development in rice by modulating photosynthetic electron transport rate.

PubMed

Ramamoorthy, Rengasamy; Vishal, Bhushan; Ramachandran, Srinivasan; Kumar, Prakash P

2018-02-01

Ds insertion in rice OsPS1-F gene results in semi-dwarf plants with reduced tiller number and grain yield, while genetic complementation with OsPS1-F rescued the mutant phenotype. Photosynthetic electron transport is regulated in the chloroplast thylakoid membrane by multi-protein complexes. Studies about photosynthetic machinery and its subunits in crop plants are necessary, because they could be crucial for yield enhancement in the long term. Here, we report the characterization of OsPS1-F (encoding Oryza sativa PHOTOSYSTEM 1-F subunit) using a single copy Ds insertion rice mutant line. The homozygous mutant (osps1-f) showed striking difference in growth and development compared to the wild type (WT), including, reduction in plant height, tiller number, grain yield as well as pale yellow leaf coloration. Chlorophyll concentration and electron transport rate were significantly reduced in the mutant compared to the WT. OsPS1-F gene was highly expressed in rice leaves compared to other tissues at different developmental stages tested. Upon complementation of the mutant with proUBI::OsPS1-F, the observed mutant phenotypes were rescued. Our results illustrate that OsPS1-F plays an important role in regulating proper growth and development of rice plants.

Energy-resolved CT imaging with a photon-counting silicon-strip detector

NASA Astrophysics Data System (ADS)

Persson, Mats; Huber, Ben; Karlsson, Staffan; Liu, Xuejin; Chen, Han; Xu, Cheng; Yveborg, Moa; Bornefalk, Hans; Danielsson, Mats

2014-03-01

Photon-counting detectors are promising candidates for use in the next generation of x-ray CT scanners. Among the foreseen benefits are higher spatial resolution, better trade-off between noise and dose, and energy discriminating capabilities. Silicon is an attractive detector material because of its low cost, mature manufacturing process and high hole mobility. However, it is sometimes claimed to be unsuitable for use in computed tomography because of its low absorption efficiency and high fraction of Compton scatter. The purpose of this work is to demonstrate that high-quality energy-resolved CT images can nonetheless be acquired with clinically realistic exposure parameters using a photon-counting silicon-strip detector with eight energy thresholds developed in our group. We use a single detector module, consisting of a linear array of 50 0.5 × 0.4 mm detector elements, to image a phantom in a table-top lab setup. The phantom consists of a plastic cylinder with circular inserts containing water, fat and aqueous solutions of calcium, iodine and gadolinium, in different concentrations. We use basis material decomposition to obtain water, calcium, iodine and gadolinium basis images and demonstrate that these basis images can be used to separate the different materials in the inserts. We also show results showing that the detector has potential for quantitative measurements of substance concentrations.

Functional materials for breeding blankets—status and developments

NASA Astrophysics Data System (ADS)

Konishi, S.; Enoeda, M.; Nakamichi, M.; Hoshino, T.; Ying, A.; Sharafat, S.; Smolentsev, S.

2017-09-01

The development of tritium breeder, neutron multiplier and flow channel insert materials for the breeding blanket of the DEMO reactor is reviewed. Present emphasis is on the ITER test blanket module (TBM); lithium metatitanate (Li2TiO3) and lithium orthosilicate (Li4SiO4) pebbles have been developed by leading TBM parties. Beryllium pebbles have been selected as the neutron multiplier. Good progress has been made in their fabrication; however, verification of the design by experiments is in the planning stage. Irradiation data are also limited, but the decrease in thermal conductivity of beryllium due to irradiation followed by swelling is a concern. Tests at ITER are regarded as a major milestone. For the DEMO reactor, improvement of the breeder has been attempted to obtain a higher lithium content, and Be12Ti and other beryllide intermetallic compounds that have superior chemical stability have been studied. LiPb eutectic has been considered as a DEMO blanket in the liquid breeder option and is used as a coolant to achieve a higher outlet temperature; a SiC flow channel insert is used to prevent magnetohydrodynamic pressure drop and corrosion. A significant technical gap between ITER TBM and DEMO is recognized, and the world fusion community is working on ITER TBM and DEMO blanket development in parallel.

Modulatory Action by the Serotonergic System: Behavior and Neurophysiology in Drosophila melanogaster

PubMed Central

Majeed, Zana R.; Abdeljaber, Esraa; Soveland, Robin; Cornwell, Kristin; Bankemper, Aubrey; Koch, Felicitas; Cooper, Robin L.

2016-01-01

Serotonin modulates various physiological processes and behaviors. This study investigates the role of 5-HT in locomotion and feeding behaviors as well as in modulation of sensory-motor circuits. The 5-HT biosynthesis was dysregulated by feeding Drosophila larvae 5-HT, a 5-HT precursor, or an inhibitor of tryptophan hydroxylase during early stages of development. The effects of feeding fluoxetine, a selective serotonin reuptake inhibitor, during early second instars were also examined. 5-HT receptor subtypes were manipulated using RNA interference mediated knockdown and 5-HT receptor insertional mutations. Moreover, synaptic transmission at 5-HT neurons was blocked or enhanced in both larvae and adult flies. The results demonstrate that disruption of components within the 5-HT system significantly impairs locomotion and feeding behaviors in larvae. Acute activation of 5-HT neurons disrupts normal locomotion activity in adult flies. To determine which 5-HT receptor subtype modulates the evoked sensory-motor activity, pharmacological agents were used. In addition, the activity of 5-HT neurons was enhanced by expressing and activating TrpA1 channels or channelrhodopsin-2 while recording the evoked excitatory postsynaptic potentials (EPSPs) in muscle fibers. 5-HT2 receptor activation mediates a modulatory role in a sensory-motor circuit, and the activation of 5-HT neurons can suppress the neural circuit activity, while fluoxetine can significantly decrease the sensory-motor activity. PMID:26989517

The effect of thread pattern upon implant osseointegration.

PubMed

Abuhussein, Heba; Pagni, Giorgio; Rebaudi, Alberto; Wang, Hom-Lay

2010-02-01

Implant design features such as macro- and micro-design may influence overall implant success. Limited information is currently available. Therefore, it is the purpose of this paper to examine these factors such as thread pitch, thread geometry, helix angle, thread depth and width as well as implant crestal module may affect implant stability. A literature search was conducted using MEDLINE to identify studies, from simulated laboratory models, animal, to human, related to this topic using the keywords of implant thread, implant macrodesign, thread pitch, thread geometry, helix angle, thread depth, thread width and implant crestal module. The results showed how thread geometry affects the distribution of stress forces around the implant. A decreased thread pitch may positively influence implant stability. Excess helix angles in spite of a faster insertion may jeopardize the ability of implants to sustain axial load. Deeper threads seem to have an important effect on the stabilization in poorer bone quality situations. The addition of threads or microthreads up to the crestal module of an implant might provide a potential positive contribution on bone-to to-implant contact as well as on the preservation of marginal bone; nonetheless this remains to be determined. Appraising the current literature on this subject and combining existing data to verify the presence of any association between the selected characteristics may be critical in the achievement of overall implant success.

Space evaluation of optical modulators for microwave photonic on-board applications

NASA Astrophysics Data System (ADS)

Le Kernec, A.; Sotom, M.; Bénazet, B.; Barbero, J.; Peñate, L.; Maignan, M.; Esquivias, I.; Lopez, F.; Karafolas, N.

2017-11-01

Since several years, perspectives and assets offered by photonic technologies compared with their traditional RF counterparts (mass and volume reduction, transparency to RF frequency, RF isolation), make them particularly attractive for space applications [1] and, in particular, telecommunication satellites [2]. However, the development of photonic payload concepts have concurrently risen and made the problem of the ability of optoelectronic components to withstand space environment more and more pressing. Indeed, photonic components used in such photonic payloads architectures come from terrestrial networks applications in order to benefit from research and development in this field. This paper presents some results obtained in the frame of an ESA-funded project, carried out by Thales Alenia Space France, as prime contractor, and Alter Technology Group Spain (ATG) and Universidad Politecnica de Madrid (UPM), as subcontractors, one objective of which was to assess commercial high frequency optical intensity modulators for space use through a functional and environmental test campaign. Their potential applications in microwave photonic sub-systems of telecom satellite payloads are identified and related requirements are presented. Optical modulator technologies are reviewed and compared through, but not limited to, a specific figure of merit, taking into account two key features of these components : optical insertion loss and RF half-wave voltage. Some conclusions on these different technologies are given, on the basis of the test results, and their suitability for the targeted applications and environment is highlighted.

Experimental prototype of an electric elevator

NASA Astrophysics Data System (ADS)

Gaiceanu, M.; Epure, S.; Ciuta, S.

2016-08-01

The main objective is to achieve an elevator prototype powered by a three-phase voltage system via a bidirectional static power converter ac-ac with regenerating capability. In order to diminish the power size of the electric motor up to 1/3 of rated power, the elevator contains two carriages of the same weight, one serving as the payload, and the other as counterweight. Before proper operation of the static power converter, the capacitor must be charged at rated voltage via a precharge circuit. At the moment of stabilizing the DC voltage at nominal value, the AC-AC power converter can operates in the proper limits. The functions of the control structure are: the load control task, speed and torque controls. System includes transducers for current measuring, voltage sensors and encoder. As reserve power sources the hybrid battery-photovoltaic panels are used. The control voltage is modulated by implementing four types of pulse width modulations: sinusoidal, with reduced commutation, third order harmonic insertion, and the space vector modulation. Therefore, the prototype could operates with an increased efficiency, in spite of the existing ones. The experimental results confirm the well design of the chosen solution. The control solution assures bidirectional power flow control, precharge control, and load control and it is implemented on a digital signal processor. The elevator capacity is between 300-450 kg, and it is driven by using a 1.5 kW three-phase asynchronous machine.

A scintillator geometry suitable for very small PET gantries

NASA Astrophysics Data System (ADS)

Gonzalez, A. J.; Gonzalez-Montoro, A.; Aguilar, A.; Cañizares, G.; Martí, R.; Iranzo, S.; Lamprou, E.; Sanchez, S.; Sanchez, F.; Benlloch, J. M.

2017-12-01

In this work we are describing a novel approach to the scintillator crystal configuration as used in nuclear medicine imaging. Our design is related to the coupling in one PET module of the two separate crystal configurations used so far there: monolithic and crystal arrays. The particular design we have studied is based on a two-layer scintillator approach (hybrid) composed of a monolithic LYSO crystal (5-6 mm thickness) and a LYSO crystal array with 4-5 mm height (0.8 and 1 mm pixels). We show here the detector block performance, in terms of spatial, energy and DOI information, to be used as a module in the design of PET scanners. The design we propose allows one to achieve accurate three-dimensional spatial resolution (including DOI information) while assuring high detection efficiency at reasonable cost. Moreover, the proposed design improves the spatial response uniformity across the whole detector module, and especially at the edge region. The crystal arrays are mounted in the front and were well resolved. The monolithic crystal inserted between crystal array and the photosensor, provided measured FWHM resolution as good as 1.5-1.7 mm including the 1 mm source size. The monolithic block achieved a DOI resolution (FWHM) nearing 3 mm. We compared these results with an approach in which we use a single monolithic block with total volume equals to the hybrid approach. In general, comparable performances were obtained.

Tool Removes Coil-Spring Thread Inserts

NASA Technical Reports Server (NTRS)

Collins, Gerald J., Jr.; Swenson, Gary J.; Mcclellan, J. Scott

1991-01-01

Tool removes coil-spring thread inserts from threaded holes. Threads into hole, pries insert loose, grips insert, then pulls insert to thread it out of hole. Effects essentially reverse of insertion process to ease removal and avoid further damage to threaded inner surface of hole.

Method of joining a vane cavity insert to a nozzle segment of a gas turbine

DOEpatents

Burdgick, Steven Sebastian

2002-01-01

An insert containing apertures for impingement cooling a nozzle vane of a nozzle segment in a gas turbine is inserted into one end of the vane. The leading end of the insert is positioned slightly past a rib adjacent the opposite end of the vane through which the insert is inserted. The end of the insert is formed or swaged into conformance with the inner margin of the rib. The insert is then brazed or welded to the rib.

Concealed Accessory Pathways with a Single Ventricular and Two Discrete Atrial Insertion Sites.

PubMed

Kipp, Ryan T; Abu Sham'a, Raed; Hiroyuki, Ito; Han, Frederick T; Refaat, Marwan; Hsu, Jonathan C; Field, Michael E; Kopp, Douglas E; Marcus, Gregory M; Scheinman, Melvin M; Hoffmayer, Kurt S

2017-03-01

Atrioventricular reciprocating tachycardia (AVRT) utilizing a concealed accessory pathway is common. It is well appreciated that some patients may have multiple accessory pathways with separate atrial and ventricular insertion sites. We present three cases of AVRT utilizing concealed pathways with evidence that each utilizing a single ventricular insertion and two discrete atrial insertion sites. In case one, two discrete atrial insertion sites were mapped in two separate procedures, and only during the second ablation was the Kent potential identified. Ablation of the Kent potential at this site remote from the two atrial insertion sites resulted in the termination of the retrograde conduction in both pathways. Case two presented with supraventricular tachycardia (SVT) with alternating eccentric atrial activation patterns without alteration in the tachycardia cycle length. The two distinct atrial insertion sites during orthodromic AVRT and ventricular pacing were targeted and each of the two atrial insertion sites were successfully mapped and ablated. In case three, retrograde decremental conduction utilizing both atrial insertion sites was identified prior to ablation. After mapping and ablation of the first discrete atrial insertion site, tachycardia persisted utilizing the second atrial insertion site. Only after ablation of the second atrial insertion site was SVT noninducible, and VA conduction was no longer present. Concealed retrograde accessory pathways with discrete atrial insertion sites may have a common ventricular insertion site. Identification and ablation of the ventricular insertion site or the separate discrete atrial insertion sites result in successful treatment. © 2017 Wiley Periodicals, Inc.

Peripheral Intravenous Catheterisation in Obstetric Patients in the Hand or Forearm Vein: A Randomised Trial

PubMed Central

Tan, Peng Chiong; Mackeen, Anjana; Khong, Su Yen; Omar, Siti Zawiah; Azmi, M. A. Noor

2016-01-01

A peripheral intravenous catheter is often inserted as part of care during labour. The catheter is inserted into the back of the hand or lower forearm vein in usual practice. There is no trial data to guide the care provider on which is the better insertion site in any clinical setting. 307 women admitted to the labour ward who required insertion of intravenous catheter were randomised to back of hand or lower forearm vein catheter insertion. Catheter insertion is by junior to mid-grade providers. We evaluated insertion success at the first attempt, pain during insertion and catheter replacement due to malfunction as main outcomes. After catheter removal, we recorded patient satisfaction with site, future site preference and insertion site swelling, bruising, tenderness, vein thrombosis and pain. Insertion of a catheter into back of hand vein is more likely to be successful at the first attempt. Insertion pain score, catheter replacement rate, patient satisfaction, patient fidelity to site in a future insertion and insertion site complications rate are not different between trial arms. In conclusion, both insertion sites are suitable; the back of the hand vein maybe easier to cannulate and seems to be preferred by our frontline providers. PMID:26987593

Controlling the electronic and geometric structures of 2D insertions to realize high performance metal/insertion-MoS2 sandwich interfaces.

PubMed

Su, Jie; Feng, Liping; Zeng, Wei; Liu, Zhengtang

2017-06-08

Metal/insertion-MoS 2 sandwich interfaces are designed to reduce the Schottky barriers at metal-MoS 2 interfaces. The effects of geometric and electronic structures of two-dimensional (2D) insertion materials on the contact properties of metal/insertion-MoS 2 interfaces are comparatively studied by first-principles calculations. Regardless of the geometric and electronic structures of 2D insertion materials, Fermi level pinning effects and charge scattering at the metal/insertion-MoS 2 interface are weakened due to weak interactions between the insertion and MoS 2 layers, no gap states and negligible structural deformations for MoS 2 layers. The Schottky barriers at metal/insertion-MoS 2 interfaces are induced by three interface dipoles and four potential steps that are determined by the charge transfers and structural deformations of 2D insertion materials. The lower the electron affinities of 2D insertion materials, the more are the electrons lost from the Sc surface, resulting in lower n-type Schottky barriers at Sc/insertion-MoS 2 interfaces. The larger the ionization potentials and the thinner the thicknesses of 2D insertion materials, the fewer are the electrons that accumulate at the Pt surface, leading to lower p-type Schottky barriers at Pt/insertion-MoS 2 interfaces. All Sc/insertion-MoS 2 interfaces exhibited ohmic characters. The Pt/BN-MoS 2 interface exhibits the lowest p-type Schottky barrier of 0.52 eV due to the largest ionization potential (∼6.88 eV) and the thinnest thickness (single atomic layer thickness) of BN. These results in this work are beneficial to understand and design high performance metal/insertion-MoS 2 interfaces through 2D insertion materials.

PDB file parser and structure class implemented in Python.

PubMed

Hamelryck, Thomas; Manderick, Bernard

2003-11-22

The biopython project provides a set of bioinformatics tools implemented in Python. Recently, biopython was extended with a set of modules that deal with macromolecular structure. Biopython now contains a parser for PDB files that makes the atomic information available in an easy-to-use but powerful data structure. The parser and data structure deal with features that are often left out or handled inadequately by other packages, e.g. atom and residue disorder (if point mutants are present in the crystal), anisotropic B factors, multiple models and insertion codes. In addition, the parser performs some sanity checking to detect obvious errors. The Biopython distribution (including source code and documentation) is freely available (under the Biopython license) from http://www.biopython.org

Noise estimation of beam position monitors at RHIC

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

Shen, X.; Bai, M.; Lee, S. Y.

2014-02-10

Beam position monitors (BPM) are used to record the average orbits and transverse turn-by-turn displacements of the beam centroid motion. The Relativistic Hadron Ion Collider (RHIC) has 160 BPMs for each plane in each of the Blue and Yellow rings: 72 dual-plane BPMs in the insertion regions (IR) and 176 single-plane modules in the arcs. Each BPM is able to acquire 1024 or 4096 consecutive turn-by-turn beam positions. Inevitably, there are broadband noisy signals in the turn-by-turn data due to BPM electronics as well as other sources. A detailed study of the BPM noise performance is critical for reliable opticsmore » measurement and beam dynamics analysis based on turn-by-turn data.« less

Method and Pd/V2 O5 device for H2 detection

DOEpatents

Liu, Ping [San Diego, CA; Tracy, C Edwin [Golden, CO; Pitts, J Roland [Lakewood, CO; Smith, II, R. Davis; Lee, Se-Hee [Lakewood, CO

2011-12-27

Methods and Pd/V.sub.2O.sub.5 devices for hydrogen detection are disclosed. An exemplary method of preparing an improved sensor for chemochromic detection of hydrogen gas over a wide response range exhibits stability during repeated coloring/bleaching cycles upon exposure and removal of hydrogen gas. The method may include providing a substrate. The method may also include depositing a V.sub.20.sub.5 layer that functions as a H.sub.2 insertion host in a Pd/V.sub.20.sub.5 hydrogen sensor to be formed on said substrate. The method may also include depositing a Pd layer onto said V.sub.20.sub.5 layer; said Pd layer functioning as an optical modulator.

Design and Photovoltaic Properties of Graphene/Silicon Solar Cell

NASA Astrophysics Data System (ADS)

Xu, Dikai; Yu, Xuegong; Yang, Lifei; Yang, Deren

2018-04-01

Graphene/silicon (Gr/Si) Schottky junction solar cells have attracted widespread attention for the fabrication of high-efficiency and low-cost solar cells. However, their performance is still limited by the working principles of Schottky junctions. Modulating the working mechanism of the solar cells into a quasi p-n junction has advantages, including higher open-circuit voltage (V OC) and less carrier recombination. In this study, Gr/Si quasi p-n junction solar cells were formed by inserting a tunneling Al2O3 interlayer in-between graphene and silicon, which led to obtain the PCE up to 8.48% without antireflection or chemical doping techniques. Our findings could pave a new way for the development of Gr/Si solar cells.

Parallel multiplex laser feedback interferometry

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

Zhang, Song; Tan, Yidong; Zhang, Shulian, E-mail: zsl-dpi@mail.tsinghua.edu.cn

2013-12-15

We present a parallel multiplex laser feedback interferometer based on spatial multiplexing which avoids the signal crosstalk in the former feedback interferometer. The interferometer outputs two close parallel laser beams, whose frequencies are shifted by two acousto-optic modulators by 2Ω simultaneously. A static reference mirror is inserted into one of the optical paths as the reference optical path. The other beam impinges on the target as the measurement optical path. Phase variations of the two feedback laser beams are simultaneously measured through heterodyne demodulation with two different detectors. Their subtraction accurately reflects the target displacement. Under typical room conditions, experimentalmore » results show a resolution of 1.6 nm and accuracy of 7.8 nm within the range of 100 μm.« less

J-PET: A New Technology for the Whole-body PET Imaging

NASA Astrophysics Data System (ADS)

Niedźwiecki, S.; Białas, P.; Curceanu, C.; Czerwiński, E.; Dulski, K.; Gajos, A.; Głowacz, B.; Gorgol, M.; Hiesmayr, B. C.; Jasińska, B.; Kapłon, Ł.; Kisielewska-Kamińska, D.; Korcyl, G.; Kowalski, P.; Kozik, T.; Krawczyk, N.; Krzemień, W.; Kubicz, E.; Mohammed, M.; Pawlik-Niedźwiecka, M.; Pałka, M.; Raczyński, L.; Rudy, Z.; Sharma, N. G.; Sharma, S.; Shopa, R. Y.; Silarski, M.; Skurzok, M.; Wieczorek, A.; Wiślicki, W.; Zgardzińska, B.; Zieliński, M.; Moskal, P.

The Jagiellonian Positron Emission Tomograph (J-PET) is the first PET built from plastic scintillators. J-PET prototype consists of 192 detection modules arranged axially in three layers forming a cylindrical diagnostic chamber with the inner diameter of 85 cm and the axial field-of-view of 50 cm. An axial arrangement of long strips of plastic scintillators, their small light attenuation, superior timing properties, and relative ease of the increase of the axial field-of-view opens promising perspectives for the cost effective construction of the whole-body PET scanner, as well as construction of MR and CT compatible PET inserts. Present status of the development of the J-PET tomograph will be presented and discussed.

Macromolecular crystal growing system

NASA Technical Reports Server (NTRS)

Snyder, Robert S. (Inventor); Herren, Blair J. (Inventor); Carter, Daniel C. (Inventor); Yost, Vaughn H. (Inventor); Bugg, Charles E. (Inventor); Delucas, Lawrence J. (Inventor); Suddath, Fred L. (Inventor)

1991-01-01

A macromolecular crystal growing system especially designed for growing crystals in the low gravity of space as well as the gravity of earth includes at least one tray assembly, a carrier assembly which receives the tray, and a refrigeration-incubation module in which the carrier assembly is received. The tray assembly includes a plurality of sealed chambers with a plastic syringe and a plug means for the double tip of the syringe provided therein. Ganging mechanisms operate the syringes and plugs simultaneously in a precise and smooth operation. Preferably, the tray assemblies are mounted on ball bearing slides for smooth operation in inserting and removing the tray assemblies into the carrier assembly. The plugging mechanism also includes a loading control mechanism. A mechanism for leaving a syringe unplugged is also provided.

A powerful enhancement to the DMAP alter capability

NASA Technical Reports Server (NTRS)

Pamidi, P. R.

1989-01-01

A powerful enhancement to the DMAP alter capability was developed and is available on all RPK-supported versions of COSMIC/NASTRAN. This enhancement involves the addition of two alter control cards, called INSERT and DELETE, to the Executive Control Deck. These cards allow for DMAP alters to be made by referencing DMAP statements by their module names rather than by their statement numbers in the rigid format DMAP sequence. This allows for increased user convenience and flexibility and makes alters more meaningful to the user. In addition, DMAP alter packages employing the alter control cards will be much less susceptible to future changes in rigid format DMAPs than alter packages employing the standard ALTER control cards. The usage of the cards is illustrated by examples.

[Current status and future prospects of research on Fukuyama muscular dystrophy].

PubMed

Toda, Tatsushi

2015-08-01

Fukuyama congenital muscular dystrophy(FCMD) is a second common childhood muscular dystrophy in Japan. All FCMD patients have ancestral insertion of the SVA retrotransposal element into fukutin. We show that aberrant mRNA splicing induced by SVA exon-trapping caused FCMD. Introduction of 3 cocktailed antisense oligonucleotides(AONs) targeting around these splice sites prevented pathogenic splicing in FCMD patient cells and model mice, and normalized protein production and functions of Fukutin as well as O-glycosylation of α-dystroglycan. We show the promise of splicing modulation therapy as the first radical clinical treatment for FCMD in the near future. We also show that fukutin is prerequisite to ameliorate muscular dystrophic phenotype by myofiber-selective LARGE expression. Recent advances in FCMD are discussed.

Environmental Stress Induces Trinucleotide Repeat Mutagenesis in Human Cells by Alt-Nonhomologous End Joining Repair.

PubMed

Chatterjee, Nimrat; Lin, Yunfu; Yotnda, Patricia; Wilson, John H

2016-07-31

Multiple pathways modulate the dynamic mutability of trinucleotide repeats (TNRs), which are implicated in neurodegenerative disease and evolution. Recently, we reported that environmental stresses induce TNR mutagenesis via stress responses and rereplication, with more than 50% of mutants carrying deletions or insertions-molecular signatures of DNA double-strand break repair. We now show that knockdown of alt-nonhomologous end joining (alt-NHEJ) components-XRCC1, LIG3, and PARP1-suppresses stress-induced TNR mutagenesis, in contrast to the components of homologous recombination and NHEJ, which have no effect. Thus, alt-NHEJ, which contributes to genetic mutability in cancer cells, also plays a novel role in environmental stress-induced TNR mutagenesis. Published by Elsevier Ltd.

Proteomic analysis of protein phosphatase Z1 from Candida albicans

PubMed Central

Pfliegler, Walter P.; Petrényi, Katalin; Boros, Enikő; Pócsi, István; Tőzsér, József; Dombrádi, Viktor

2017-01-01

Protein phosphatase Z is a “novel type” fungus specific serine/threonine protein phosphatase. Previously our research group identified the CaPPZ1 gene in the opportunistic pathogen Candida albicans and reported that the gene deletion had several important physiological consequences. In order to reveal the protein targets and the associated mechanisms behind the functions of the phosphatase a proteomic method was adopted for the comparison of the cappz1 deletion mutant and the genetically matching QMY23 control strain. Proteins extracted from the control and deletion mutant strains were separated by two-dimensional gel electrophoresis and the protein spots were stained with RuBPS and Pro-Q Diamond in order to visualize the total proteome and the phosphoproteome, respectively. The alterations in spot intensities were determined by densitometry and were analysed with the Delta2D (Decodon) software. Spots showing significantly different intensities between the mutant and control strains were excised from the gels and were digested with trypsin. The resulting peptides were identified by LC-MS/MS mass spectrometry. As many as 15 protein spots were found that exhibited significant changes in their intensity upon the deletion of the phosphatase and 20 phosphoproteins were identified in which the level of phosphorylation was modified significantly in the mutant. In agreement with previous findings we found that the affected proteins function in protein synthesis, oxidative stress response, regulation of morphology and metabolism. Among these proteins we identified two potential CaPpz1 substrates (Eft2 and Rpp0) that may regulate the elongation step of translation. RT-qPCR experiments revealed that the expression of the genes coding for the affected proteins was not altered significantly. Thus, the absence of CaPpz1 exerted its effects via protein synthesis/degradation and phosphorylation/dephosphorylation. In addition, our proteomics data strongly suggested a role for CaPpz1 in biofilm formation, was confirmed experimentally. Thus our unbiased proteomic approach lead to the discovery of a novel function for this phosphatase in C. albicans. PMID:28837603

Method and design for externally applied laser welding of internal connections in a high power electrochemical cell

DOEpatents

Martin, Charles E; Fontaine, Lucien; Gardner, William H

2014-01-21

An electrochemical cell includes components that are welded from an external source after the components are assembled in a cell canister. The cell canister houses electrode tabs and a core insert. An end cap insert is disposed opposite the core insert. An external weld source, such as a laser beam, is applied to the end cap insert, such that the end cap insert, the electrode tabs, and the core insert are electrically coupled by a weld which extends from the end cap insert to the core insert.

Effects of P Element Insertions on Quantitative Traits in Drosophila Melanogaster

PubMed Central

Mackay, TFC.; Lyman, R. F.; Jackson, M. S.

1992-01-01

P element mutagenesis was used to construct 94 third chromosome lines of Drosophila melanogaster which contained on average 3.1 stable P element inserts, in an inbred host strain background previously free of P elements. The homozygous and heterozygous effects of the inserts on viability and abdominal and sternopleural bristle number were ascertained by comparing the chromosome lines with inserts to insert-free control lines of the inbred host strain. P elements reduced average homozygous viability by 12.2% per insert and average heterozygous viability by 5.5% per insert, and induced recessive lethal mutations at a rate of 3.8% per insert. Mutational variation for the bristle traits averaged over both sexes was 0.03V(e) per homozygous P insert and 0.003V(e) per heterozygous P insert, where V(e) is the environmental variance. Mutational variation was greater for the sexes considered separately because inserts had large pleiotropic effects on sex dimorphism of bristle characters. The distributions of homozygous effects of inserts on the bristle traits were asymmetrical, with the largest effects in the direction of reducing bristle number; and highly leptokurtic, with most of the increase in variance contributed by a few lines with large effects. The inserts had partially recessive effects on the bristle traits. Insert lines with extreme bristle effects had on average greatly reduced viability. PMID:1311697

Validation of a Projection-domain Insertion of Liver Lesions into CT Images

PubMed Central

Chen, Baiyu; Ma, Chi; Leng, Shuai; Fidler, Jeff L.; Sheedy, Shannon P.; McCollough, Cynthia H.; Fletcher, Joel G.; Yu, Lifeng

2016-01-01

Rationale and Objectives The aim of this study was to validate a projection-domain lesion-insertion method with observer studies. Materials and Methods A total of 51 proven liver lesions were segmented from computed tomography images, forward projected, and inserted into patient projection data. The images containing inserted and real lesions were then reconstructed and examined in consensus by two radiologists. First, 102 lesions (51 original, 51 inserted) were viewed in a randomized, blinded fashion and scored from 1 (absolutely inserted) to 10 (absolutely real). Statistical tests were performed to compare the scores for inserted and real lesions. Subsequently, a two-alternative-forced-choice test was conducted, with lesions viewed in pairs (real vs. inserted) in a blinded fashion. The radiologists selected the inserted lesion and provided a confidence level of 1 (no confidence) to 5 (completely certain). The number of lesion pairs that were incorrectly classified was calculated. Results The scores for inserted and proven lesions had the same median (8) and similar interquartile ranges (inserted, 5.5–8; real, 6.5–8). The means scores were not significantly different between real and inserted lesions (P value = 0.17). The receiver operating characteristic curve was nearly diagonal, with an area under the curve of 0.58 ± 0.06. For the two-alternative-forced-choice study, the inserted lesions were incorrectly identified in 49% (25 out of 51) of pairs; radiologists were incorrect in 38% (3 out of 8) of pairs even when they felt very confident in identifying the inserted lesion (confidence level ≥4). Conclusions Radiologists could not distinguish between inserted and real lesions, thereby validating the lesion-insertion technique, which may be useful for conducting virtual clinical trials to optimize image quality and radiation dose. PMID:27432267

Descemet's Stripping Automated Endothelial Keratoplasty Tissue Insertion Devices

PubMed Central

Khan, Salman Nasir; Shiakolas, Panos S.; Mootha, Venkateswara Vinod

2015-01-01

This review study provides information regarding the construction, design, and use of six commercially available endothelial allograft insertion devices applied for Descemet's stripping automated endothelial keratoplasty (DSAEK). We also highlight issues being faced in DSAEK and discuss the methods through which medical devices such as corneal inserters may alleviate these issues. Inserter selection is of high importance in the DSAEK procedure since overcoming the learning curve associated with the use of an insertion device is a time and energy consuming process. In the present review, allograft insertion devices were compared in terms of design, construction material, insertion technique, dimensions, incision requirements and endothelial cell loss to show their relative merits and capabilities based on available data in the literature. Moreover, the advantages/disadvantages of various insertion devices used for allograft insertion in DSAEK are reviewed and compared. The information presented in this review can be utilized for better selection of an insertion device for DSAEK. PMID:27051492

Converging flow joint insert system at an intersection between adjacent transitions extending between a combustor and a turbine assembly in a gas turbine engine

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

Wiebe, David J.; Carlson, Andrew; Stoker, Kyle C.

A transition duct system for routing a gas flow in a combustion turbine engine is provided. The transition duct system includes one or more converging flow joint inserts forming a trailing edge at an intersection between adjacent transition ducts. The converging flow joint insert may be contained within a converging flow joint insert receiver and may be disconnected from the transition duct bodies by which the converging flow joint insert is positioned. Being disconnected eliminates stress formation within the converging flow joint insert, thereby enhancing the life of the insert. The converging flow joint insert may be removable such thatmore » the insert can be replaced once worn beyond design limits.« less

Valve

DOEpatents

Cho, Nakwon

1980-01-01

A positive acting valve suitable for operation in a corrosive environment is provided. The valve includes a hollow valve body defining an open-ended bore for receiving two, axially aligned, spaced-apart, cylindrical inserts. One insert, designated the seat insert, terminates inside the valve body in an annular face which lies within plane normal to the axis of the two inserts. An elastomeric O-ring seal is disposed in a groove extending about the annular face. The other insert, designated the wedge insert, terminates inside the valve body in at least two surfaces oppositely inclined with respect to each other and with respect to a plane normal to the axis of the two inserts. An elongated reciprocable gate, movable between the two inserts along a path normal to the axis of the two inserts, has a first flat face portion disposed adjacent and parallel to the annular face of the seat insert. The gate has a second face portion opposite to the first face portion provided with at least two oppositely inclined surfaces for mating with respective inclined surfaces of the wedge insert. An opening is provided through the gate which registers with a flow passage through the two inserts when the valve is open. Interaction of the respective inclined surfaces of the gate and wedge insert act to force the first flat face portion of the gate against the O-ring seal in the seat insert at the limits of gate displacement where it reaches its respective fully open and fully closed positions.

Coordination of intrinsic and extrinsic hand muscle activity as a function of wrist joint angle during two-digit grasping.

PubMed

Johnston, Jamie A; Bobich, Lisa R; Santello, Marco

2010-04-26

Fingertip forces result from the activation of muscles that cross the wrist and muscles whose origins and insertions reside within the hand (extrinsic and intrinsic hand muscles, respectively). Thus, tasks that involve changes in wrist angle affect the moment arm and length, hence the force-producing capabilities, of extrinsic muscles only. If a grasping task requires the exertion of constant fingertip forces, the Central Nervous System (CNS) may respond to changes in wrist angle by modulating the neural drive to extrinsic or intrinsic muscles only or by co-activating both sets of muscles. To distinguish between these scenarios, we recorded electromyographic (EMG) activity of intrinsic and extrinsic muscles of the thumb and index finger as a function of wrist angle during a two-digit object hold task. We hypothesized that changes in wrist angle would elicit EMG amplitude modulation of the extrinsic and intrinsic hand muscles. In one experimental condition we asked subjects to exert the same digit forces at each wrist angle, whereas in a second condition subjects could choose digit forces for holding the object. EMG activity was significantly modulated in both extrinsic and intrinsic muscles as a function of wrist angle (both p<0.05) but only for the constant force condition. Furthermore, EMG modulation resulted from uniform scaling of EMG amplitude across all muscles. We conclude that the CNS controlled both extrinsic and intrinsic muscles as a muscle synergy. These findings are discussed within the theoretical frameworks of synergies and common neural input across motor nuclei of hand muscles. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

SMRT: A new, modular snow microwave radiative transfer model

NASA Astrophysics Data System (ADS)

Picard, Ghislain; Sandells, Melody; Löwe, Henning; Dumont, Marie; Essery, Richard; Floury, Nicolas; Kontu, Anna; Lemmetyinen, Juha; Maslanka, William; Mätzler, Christian; Morin, Samuel; Wiesmann, Andreas

2017-04-01

Forward models of radiative transfer processes are needed to interpret remote sensing data and derive measurements of snow properties such as snow mass. A key requirement and challenge for microwave emission and scattering models is an accurate description of the snow microstructure. The snow microwave radiative transfer model (SMRT) was designed to cater for potential future active and/or passive satellite missions and developed to improve understanding of how to parameterize snow microstructure. SMRT is implemented in Python and is modular to allow easy intercomparison of different theoretical approaches. Separate modules are included for the snow microstructure model, electromagnetic module, radiative transfer solver, substrate, interface reflectivities, atmosphere and permittivities. An object-oriented approach is used with carefully specified exchanges between modules to allow future extensibility i.e. without constraining the parameter list requirements. This presentation illustrates the capabilities of SMRT. At present, five different snow microstructure models have been implemented, and direct insertion of the autocorrelation function from microtomography data is also foreseen with SMRT. Three electromagnetic modules are currently available. While DMRT-QCA and Rayleigh models need specific microstructure models, the Improved Born Approximation may be used with any microstructure representation. A discrete ordinates approach with stream connection is used to solve the radiative transfer equations, although future inclusion of 6-flux and 2-flux solvers are envisioned. Wrappers have been included to allow existing microwave emission models (MEMLS, HUT, DMRT-QMS) to be run with the same inputs and minimal extra code (2 lines). Comparisons between theoretical approaches will be shown, and evaluation against field experiments in the frequency range 5-150 GHz. SMRT is simple and elegant to use whilst providing a framework for future development within the community.

The 20 GHz GaAs monolithic power amplifier module development

NASA Technical Reports Server (NTRS)

1984-01-01

The development of a 20 GHz GaAs FET monlithic power amplifier module for advanced communication applications is described. Four-way power combing of four 0.6 W amplifier modules is used as the baseline approach. For this purpose, a monolithic four-way traveling-wave power divider/combiner was developed. Over a 20 GHz bandwidth (10 to 30 GHz), an insertion loss of no more than 1.2 dB was measured for a pair of back-to-back connected divider/combiners. Isolation between output ports is better than 20 dB, and VSWRs are better than 21:1. A distributed amplifier with six 300 micron gate width FETs and gate and drain transmission line tapers has been designed, fabricated, and evaluated for use as an 0.6 W module. This amplifier has achieved state-of-the-art results of 0.5 W output power with at least 4 dB gain across the entire 2 to 21 GHz frequency range. An output power of 2 W was achieved at a measurement frequency of 18 GHz when four distributed amplifiers were power-combined using a pair of traveling-wave divider/combiners. Another approach is the direct common-source cascading of three power FET stages. An output power of up to 2W with 12 dB gain and 20% power-added efficiency has been achieved with this approach (at 17 GHz). The linear gain was 14 dB at 1 W output. The first two stages of the three-stage amplifier have achieved an output power of 1.6 W with 9 dB gain and 26% power-added efficiency at 16 GHz.

Monolithically integrated quantum dot optical gain modulator with semiconductor optical amplifier for 10-Gb/s photonic transmission

NASA Astrophysics Data System (ADS)

Yamamoto, Naokatsu; Akahane, Kouichi; Umezawa, Toshimasa; Kawanishi, Tetsuya

2015-03-01

Short-range interconnection and/or data center networks require high capacity and a large number of channels in order to support numerous connections. Solutions employed to meet these requirements involve the use of alternative wavebands to increase the usable optical frequency range. We recently proposed the use of the T- and O-bands (Thousand band: 1000-1260 nm, Original band: 1260-1360 nm) as alternative wavebands because large optical frequency resources (>60 THz) can be easily employed. In addition, a simple and compact Gb/s-order high-speed optical modulator is a critical photonic device for short-range communications. Therefore, to develop an optical modulator that acts as a highfunctional photonic device, we focused on the use of self-assembled quantum dots (QDs) as a three-dimensional (3D) confined structure because QD structures are highly suitable for realizing broadband optical gain media in the T+O bands. In this study, we use the high-quality broadband QD optical gain to develop a monolithically integrated QD optical gain modulator (QD-OGM) device that has a semiconductor optical amplifier (QD-SOA) for Gb/s-order highspeed optical data generation in the 1.3-μm waveband. The insertion loss of the device can be compensated through the SOA, and we obtained an optical gain change of up to ~7 dB in the OGM section. Further, we successfully demonstrate a 10-Gb/s clear eye opening using the QD-OGM/SOA device with a clock-data recovery sequence at the receiver end. These results suggest that the monolithic QD-EOM/SOA is suitable for increasing the number of wavelength channels for smart short-range communications.

Design of a multimodal (1H/23Na MR/CT) anthropomorphic thorax phantom.

PubMed

Neumann, Wiebke; Lietzmann, Florian; Schad, Lothar R; Zöllner, Frank G

2017-06-01

This work proposes a modular, anthropomorphic MR and CT thorax phantom that enables the comparison of experimental studies for quantitative evaluation of deformable, multimodal image registration algorithms and realistic multi-nuclear MR imaging techniques. A human thorax phantom was developed with insertable modules representing lung, liver, ribs and additional tracking spheres. The quality of human tissue mimicking characteristics was evaluated for 1 H and 23 Na MR as well as CT imaging. The position of landmarks in the lung lobes was tracked during CT image acquisition at several positions during breathing cycles. 1 H MR measurements of the liver were repeated after seven months to determine long term stability. The modules possess HU, T 1 and T 2 values comparable to human tissues (lung module: -756±148HU, artificial ribs: 218±56HU (low CaCO 3 concentration) and 339±121 (high CaCO 3 concentration), liver module: T 1 =790±28ms, T 2 =65±1ms). Motion analysis showed that the landmarks in the lung lobes follow a 3D trajectory similar to human breathing motion. The tracking spheres are well detectable in both CT and MRI. The parameters of the tracking spheres can be adjusted in the following ranges to result in a distinct signal: HU values from 150 to 900HU, T 1 relaxation time from 550ms to 2000ms, T 2 relaxation time from 40ms to 200ms. The presented anthropomorphic multimodal thorax phantom fulfills the demands of a simple, inexpensive system with interchangeable components. In future, the modular design allows for complementing the present set up with additional modules focusing on specific research targets such as perfusion studies, 23 Na MR quantification experiments and an increasing level of complexity for motion studies. Copyright © 2016. Published by Elsevier GmbH.

Recurrence, submicroscopic complexity, and potential clinical relevance of copy gains detected by array CGH that are shown to be unbalanced insertions by FISH.

PubMed

Neill, Nicholas J; Ballif, Blake C; Lamb, Allen N; Parikh, Sumit; Ravnan, J Britt; Schultz, Roger A; Torchia, Beth S; Rosenfeld, Jill A; Shaffer, Lisa G

2011-04-01

Insertions occur when a segment of one chromosome is translocated and inserted into a new region of the same chromosome or a non-homologous chromosome. We report 71 cases with unbalanced insertions identified using array CGH and FISH in 4909 cases referred to our laboratory for array CGH and found to have copy-number abnormalities. Although the majority of insertions were non-recurrent, several recurrent unbalanced insertions were detected, including three der(Y)ins(Y;18)(q?11.2;p11.32p11.32)pat inherited from parents carrying an unbalanced insertion. The clinical significance of these recurrent rearrangements is unclear, although the small size, limited gene content, and inheritance pattern of each suggests that the phenotypic consequences may be benign. Cryptic, submicroscopic duplications were observed at or near the insertion sites in two patients, further confounding the clinical interpretation of these insertions. Using FISH, linear amplification, and array CGH, we identified a 126-kb duplicated region from 19p13.3 inserted into MECP2 at Xq28 in a patient with symptoms of Rett syndrome. Our results demonstrate that although the interpretation of most non-recurrent insertions is unclear without high-resolution insertion site characterization, the potential for an otherwise benign duplication to result in a clinically relevant outcome through the disruption of a gene necessitates the use of FISH to determine whether copy-number gains detected by array CGH represent tandem duplications or unbalanced insertions. Further follow-up testing using techniques such as linear amplification or sequencing should be used to determine gene involvement at the insertion site after FISH has identified the presence of an insertion.

Technical Note: Computer-Manufactured Inserts for Prosthetic Sockets

PubMed Central

Sanders, Joan E.; McLean, Jake B.; Cagle, John C.; Gardner, David W.; Allyn, Katheryn J.

2016-01-01

The objective of this research was to use computer-aided design software and a tabletop 3-D additive manufacturing system to design and fabricate custom plastic inserts for trans-tibial prosthesis users. Shape quality of inserts was tested right after they were inserted into participant’s test sockets and again after four weeks of wear. Inserts remained properly positioned and intact throughout testing. Right after insertion the inserts caused the socket to be slightly under-sized, by a mean of 0.11 mm, approximately 55% of the thickness of a nylon sheath. After four weeks of wear the under-sizing was less, averaging 0.03 mm, approximately 15% of the thickness of a nylon sheath. Thus the inserts settled into the sockets over time. If existing prosthetic design software packages were enhanced to conduct insert design and to automatically generate fabrication files for manufacturing, then computer manufactured inserts may offer advantages over traditional methods in terms of speed of fabrication, ease of design, modification, and record keeping. PMID:27212209

Teleoperated master-slave needle insertion.

PubMed

Abolhassani, Niki; Patel, Rajni V

2009-12-01

Accuracy of needle tip placement and needle tracking in soft tissue are of particular importance in many medical procedures. In recent years, developing autonomous and teleoperated systems for needle insertion has become an active area of research. In this study, needle insertion was performed using a master-slave set-up with multi-degrees of freedom. The effect of force feedback on the accuracy of needle insertion was investigated. In addition, this study compared autonomous, teleoperated and semi-autonomous needle insertion. The results of this study show that incorporation of force feedback can improve teleoperated needle insertion. However, autonomous and semi-autonomous needle insertions, which use feedback from a deflection model, provide significantly better performance. Development of a haptic master-slave needle insertion system, which is capable of performing some autonomous tasks based on feedback from tissue deformation and needle deflection models, can improve the performance of autonomous robotics-based insertions as well as non-autonomous teleoperated manual insertions. Copyright (c) 2009 John Wiley & Sons, Ltd.

Effect of vibration frequency on biopsy needle insertion force.

PubMed

Tan, Lei; Qin, Xuemei; Zhang, Qinhe; Zhang, Hongcai; Dong, Hongjian; Guo, Tuodang; Liu, Guowei

2017-05-01

Needle insertion is critical in many clinical medicine procedures, such as biopsy, brachytherapy, and injection therapy. A platform with two degrees of freedom was set up to study the effect of vibration frequency on needle insertion force. The gel phantom deformation at the needle cutting edge and the Voigt model are utilized to develop a dynamic model to explain the relationship between the insertion force and needle-tip velocity. The accuracy of this model was verified by performing needle insertions into phantom gel. The effect of vibration on insertion force can be explained as the vibration increasing the needle-tip velocity and subsequently increasing the insertion force. In a series of needle insertion experiments with different vibration frequencies, the peak forces were selected for comparison to explore the effect of vibration frequency on needle insertion force. The experimental results indicate that the insertion force at 500Hz increases up to 17.9% compared with the force at 50Hz. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Development of an algorithm for improving quality and information processing capacity of MathSpeak synthetic speech renderings.

PubMed

Isaacson, M D; Srinivasan, S; Lloyd, L L

2010-01-01

MathSpeak is a set of rules for non speaking of mathematical expressions. These rules have been incorporated into a computerised module that translates printed mathematics into the non-ambiguous MathSpeak form for synthetic speech rendering. Differences between individual utterances produced with the translator module are difficult to discern because of insufficient pausing between utterances; hence, the purpose of this study was to develop an algorithm for improving the synthetic speech rendering of MathSpeak. To improve synthetic speech renderings, an algorithm for inserting pauses was developed based upon recordings of middle and high school math teachers speaking mathematic expressions. Efficacy testing of this algorithm was conducted with college students without disabilities and high school/college students with visual impairments. Parameters measured included reception accuracy, short-term memory retention, MathSpeak processing capacity and various rankings concerning the quality of synthetic speech renderings. All parameters measured showed statistically significant improvements when the algorithm was used. The algorithm improves the quality and information processing capacity of synthetic speech renderings of MathSpeak. This increases the capacity of individuals with print disabilities to perform mathematical activities and to successfully fulfill science, technology, engineering and mathematics academic and career objectives.

Use of astronomy filters in fluorescence microscopy.

PubMed

Piper, Jörg

2012-02-01

Monochrome astronomy filters are well suited for use as excitation or suppression filters in fluorescence microscopy. Because of their particular optical design, such filters can be combined with standard halogen light sources for excitation in many fluorescent probes. In this "low energy excitation," photobleaching (fading) or other irritations of native specimens are avoided. Photomicrographs can be taken from living motile fluorescent specimens also with a flash so that fluorescence images can be created free from indistinctness caused by movement. Special filter cubes or dichroic mirrors are not needed for our method. By use of suitable astronomy filters, fluorescence microscopy can be carried out with standard laboratory microscopes equipped with condensers for bright-field (BF) and dark-field (DF) illumination in transmitted light. In BF excitation, the background brightness can be modulated in tiny steps up to dark or black. Moreover, standard industry microscopes fitted with a vertical illuminator for examinations of opaque probes in DF or BF illumination based on incident light (wafer inspections, for instance) can also be used for excitation in epi-illumination when adequate astronomy filters are inserted as excitatory and suppression filters in the illuminating and imaging light path. In all variants, transmission bands can be modulated by transmission shift.

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

Fabbricatore, P.; Ambrosio, G.; Cheban, S.

The Mu2e Transport Solenoid consists of 52 coils arranged in 27 coil modules that form the S-shaped cold mass. Each coil is wound from Al-stabilized NbTi superconductor. The coils are supported by an external structural aluminum shell machined from a forged billet. Most of the coil modules house two coils, with the axis of each coil oriented at an angle of approximately 5° with respect to each other. The coils are indirectly cooled with LHe circulating in tubes welded on the shell. In order to enhance the cooling capacity, pure aluminum sheets connect the inner bore of the coils tomore » the cooling tubes. The coils are placed inside the shell by the means of a shrink-fit procedure. A full-size prototype, with all the features of the full assembly, was successfully manufactured in a collaboration between INFN Genova and Fermilab. In order to ensure an optimal mechanical prestress at the coil-shell interface, the coils are inserted into the shell through a shrink-fitting process. We present the details of the prototype with the design choices as validated by the structural analysis. In conclusion, the fabrication steps are described as well.« less

Mu2e transport solenoid prototype design and manufacturing

DOE PAGES

Fabbricatore, P.; Ambrosio, G.; Cheban, S.; ...

2016-02-08

The Mu2e Transport Solenoid consists of 52 coils arranged in 27 coil modules that form the S-shaped cold mass. Each coil is wound from Al-stabilized NbTi superconductor. The coils are supported by an external structural aluminum shell machined from a forged billet. Most of the coil modules house two coils, with the axis of each coil oriented at an angle of approximately 5° with respect to each other. The coils are indirectly cooled with LHe circulating in tubes welded on the shell. In order to enhance the cooling capacity, pure aluminum sheets connect the inner bore of the coils tomore » the cooling tubes. The coils are placed inside the shell by the means of a shrink-fit procedure. A full-size prototype, with all the features of the full assembly, was successfully manufactured in a collaboration between INFN Genova and Fermilab. In order to ensure an optimal mechanical prestress at the coil-shell interface, the coils are inserted into the shell through a shrink-fitting process. We present the details of the prototype with the design choices as validated by the structural analysis. In conclusion, the fabrication steps are described as well.« less

Modulation of risk of squamous cell carcinoma head and neck in North Indian population with polymorphisms in xeroderma pigmentosum complementation Group C gene.

PubMed

Yadav, Suresh Kumar; Singh, Sudhir; Gupta, Shalini; Brahma Bhatt, Madan Lal; Mishra, Durga P; Roy, D; Sanyal, Somali

2018-01-01

Genetic variations in nucleotide excision repair genes can alter the risk of squamous cell carcinoma of head and neck (SCCHN). The present study has genotyped 334 subjects from North Indian population for xeroderma pigmentosum complementation Group C (XPC) rs2228001A>C, XPC rs77907221 polyadenylate (PAT) deletion/insertion (D/I), xeroderma pigmentosum complementation Group D - rs13181A>C, and xeroderma pigmentosum complementation Type G rs17655 G>C polymorphisms with polymerase chain reaction (PCR)-restriction-fragment length polymorphism or allele-specific PCR methods. Compared to D allele, I allele for XPC PAT D/I polymorphism was associated with significantly decreased the risk of SCCHN (odds ratios = 0.67, 95% confidence interval [CI] =0.48-0.94, P = 0.03). Haplotype CI constituted from XPC polymorphisms was also associated with decreased risk of SCCHN (P = 0.004). In contrast, haplotype Crohn's disease significantly increased the risk for SCCHN (P < 0.00). A significant early onset of SCCHN was observed in individuals with CC genotype for XPC A>C polymorphism (P = 0.004). Our results suggest a possible risk modulation for SCCHN with XPC polymorphisms in North Indian population.

A Western blot-based investigation of the yeast secretory pathway designed for an intermediate-level undergraduate cell biology laboratory.

PubMed

Hood-Degrenier, Jennifer K

2008-01-01

The movement of newly synthesized proteins through the endomembrane system of eukaryotic cells, often referred to generally as the secretory pathway, is a topic covered in most intermediate-level undergraduate cell biology courses. An article previously published in this journal described a laboratory exercise in which yeast mutants defective in two distinct steps of protein secretion were differentiated using a genetic reporter designed specifically to identify defects in the first step of the pathway, the insertion of proteins into the endoplasmic reticulum (Vallen, 2002). We have developed two versions of a Western blotting assay that serves as a second way of distinguishing the two secretory mutants, which we pair with the genetic assay in a 3-wk laboratory module. A quiz administered before and after students participated in the lab activities revealed significant postlab gains in their understanding of the secretory pathway and experimental techniques used to study it. A second survey administered at the end of the lab module assessed student perceptions of the efficacy of the lab activities; the results of this survey indicated that the experiments were successful in meeting a set of educational goals defined by the instructor.

Life Support Systems for a New Lunar Lander

NASA Technical Reports Server (NTRS)

Anderson, Molly; Rotter, Henry; Stambaugh, Imelda; Yagoda, Evan

2012-01-01

A life support system concept has been developed for a new NASA lunar lander concept. The ground rules and assumptions driving the design of this vehicle are different from the Constellation Altair vehicle, and have led to a different design solution. For example, this concept assumes that the lander vehicle arrives in lunar orbit independently of the crew. It loiters in lunar orbit for months before rendezvousing with the Orion Multi-Purpose Crew Vehicle (MPCV), resulting in the use of solar power for this new lander, rather than fuel cells that provided product water to the life support system in the Altair vehicle. Without the need to perform a single Lunar Orbit Insertion burn for both the lander and the MPCV, the modules do not have to be centered in the same way, so the new lander has a smaller ascent module than Altair and a large habitat rather than a small airlock. This new lander utilizes suitport technology to perform EVAs from the habitat, which leads to significantly different requirements for the pressure control system. This paper describes the major trades and resulting concept design for the life support system of a new lunar lander concept. I

Life Support Systems for a New Lunar Lander

NASA Technical Reports Server (NTRS)

Anderson, Molly; Rotter, Henry; Stambaugh, Imelda; Yagoda, Evan

2011-01-01

A life support system concept has been developed for a new NASA lunar lander concept. The ground rules and assumptions driving the design of this vehicle are different from the Constellation Altair vehicle, and have led to a different design solution. For example, this concept assumes that the lander vehicle arrives in lunar orbit independently of the crew. It loiters in lunar orbit for months before rendezvousing with the Orion Multi-Purpose Crew Vehicle (MPCV), resulting in the use of solar power for this new lander, rather than fuel cells that provided product water to the life support system in the Altair vehicle. Without the need to perform a single Lunar Orbit Insertion burn for both the lander and the MPCV, the modules do not have to be centered in the same way, so the new lander has a smaller ascent module than Altair and a large habitat rather than a small airlock. This new lander utilizes suitport technology to perform EVAs from the habitat, which leads to significantly different requirements for the pressure control system. This paper describes the major trades and resulting concept design for the life support system of a new lunar lander concept.

Progress on ITER Diagnostic Integration

NASA Astrophysics Data System (ADS)

Johnson, David; Feder, Russ; Klabacha, Jonathan; Loesser, Doug; Messineo, Mike; Stratton, Brentley; Wood, Rick; Zhai, Yuhu; Andrew, Phillip; Barnsley, Robin; Bertschinger, Guenter; Debock, Maarten; Reichle, Roger; Udintsev, Victor; Vayakis, George; Watts, Christopher; Walsh, Michael

2013-10-01

On ITER, front-end components must operate reliably in a hostile environment. Many will be housed in massive port plugs, which also shield the machine from radiation. Multiple diagnostics reside in a single plug, presenting new challenges for developers. Front-end components must tolerate thermally-induced stresses, disruption-induced mechanical loads, stray ECH radiation, displacement damage, and degradation due to plasma-induced coatings. The impact of failures is amplified due to the difficulty in performing robotic maintenance on these large structures. Motivated by needs to minimize disruption loads on the plugs, standardize the handling of shield modules, and decouple the parallel efforts of the many parties, the packaging strategy for diagnostics has recently focused on the use of 3 vertical shield modules inserted from the plasma side into each equatorial plug structure. At the front of each is a detachable first wall element with customized apertures. Progress on US equatorial and upper plugs will be used as examples, including the layout of components in the interspace and port cell regions. Supported by PPPL under contract DE-AC02-09CH11466 and UT-Battelle, LLC under contract DE-AC05-00OR22725 with the U.S. DOE.

The iFlow modelling framework v2.4: a modular idealized process-based model for flow and transport in estuaries

NASA Astrophysics Data System (ADS)

Dijkstra, Yoeri M.; Brouwer, Ronald L.; Schuttelaars, Henk M.; Schramkowski, George P.

2017-07-01

The iFlow modelling framework is a width-averaged model for the systematic analysis of the water motion and sediment transport processes in estuaries and tidal rivers. The distinctive solution method, a mathematical perturbation method, used in the model allows for identification of the effect of individual physical processes on the water motion and sediment transport and study of the sensitivity of these processes to model parameters. This distinction between processes provides a unique tool for interpreting and explaining hydrodynamic interactions and sediment trapping. iFlow also includes a large number of options to configure the model geometry and multiple choices of turbulence and salinity models. Additionally, the model contains auxiliary components, including one that facilitates easy and fast sensitivity studies. iFlow has a modular structure, which makes it easy to include, exclude or change individual model components, called modules. Depending on the required functionality for the application at hand, modules can be selected to construct anything from very simple quasi-linear models to rather complex models involving multiple non-linear interactions. This way, the model complexity can be adjusted to the application. Once the modules containing the required functionality are selected, the underlying model structure automatically ensures modules are called in the correct order. The model inserts iteration loops over groups of modules that are mutually dependent. iFlow also ensures a smooth coupling of modules using analytical and numerical solution methods. This way the model combines the speed and accuracy of analytical solutions with the versatility of numerical solution methods. In this paper we present the modular structure, solution method and two examples of the use of iFlow. In the examples we present two case studies, of the Yangtze and Scheldt rivers, demonstrating how iFlow facilitates the analysis of model results, the understanding of the underlying physics and the testing of parameter sensitivity. A comparison of the model results to measurements shows a good qualitative agreement. iFlow is written in Python and is available as open source code under the LGPL license.

21 CFR 886.5420 - Contact lens inserter/remover.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Contact lens inserter/remover. 886.5420 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5420 Contact lens inserter/remover. (a) Identification. A contact lens inserter/remover is a handheld device intended to insert or remove...

21 CFR 310.515 - Patient package inserts for estrogens.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 5 2011-04-01 2011-04-01 false Patient package inserts for estrogens. 310.515... package inserts for estrogens. (a) Requirement for a patient package insert. FDA concludes that the safe... patient package insert containing information concerning the drug's benefits and risks. An estrogen drug...

Turbine vane segment and impingement insert configuration for fail-safe impingement insert retention

DOEpatents

Burdgick, Steven Sebastian; Kellock, Iain Robertson

2003-05-13

An impingement insert sleeve is provided that is adapted to be disposed in a coolant cavity defined through a stator vane. The insert has a generally open inlet end and first and second pairs of diametrically opposed side walls, and at least one fail-safe tab defined at a longitudinal end of the insert for limiting radial displacement of the insert with respect to the stator vane.

Screw-Thread Inserts As Temporary Flow Restrictors

NASA Technical Reports Server (NTRS)

Trimarchi, Paul

1992-01-01

Coil-spring screw-thread inserts found useful as temporary flow restrictors. Inserts placed in holes through which flow restricted, effectively reducing cross sections available for flow. Friction alone holds inserts against moderate upstream pressures. Use of coil-spring thread inserts as flow restrictors conceived as inexpensive solution to problem of adjusting flow of oxygen through orifices in faceplate into hydrogen/oxygen combustion chamber. Installation and removal of threaded inserts gentle enough not to deform orifice tubes.

Electron-Beam Vapor Deposition of Mold Inserts Final Report CRADA No. TSB-777-94

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

Shepp, T.; Feeley, T.

Lawrence Livermore National Laboratory and H.G.G. Laser Fare, Inc. studied the application of electron-beam vapor deposition technology to the production of mold inserts for use in an injection molding machine by Laser Fare. Laser Fare provided LLNL with the requirements of the mold inserts as well as sample inserts. LLNL replicated the mold insert(s) to Laser Fare for testing by Laser Fare.