Datasets depicting mobility retardation of NCS proteins observed upon incubation with calcium, but not with magnesium, barium or strontium.

PubMed

Viviano, Jeffrey; Krishnan, Anuradha; Scully, Jenna; Wu, Hao; Venkataraman, Venkat

2016-06-01

In this data article we show the specificity of the Ca(2+)-induced mobility shift in three proteins that belong to the neuronal calcium sensor (NCS) protein family: Hippocalcin, GCAP1 and GCAP2. These proteins did not display a shift in mobility in native gels when incubated with divalent cations other than Ca(2+) - such as Mg(2+), Ba(2+), and Sr(2+), even at 10× concentrations. The data is similar to that obtained with another NCS protein, neurocalcin delta (Viviano et al., 2016, "Electrophoretic Mobility Shift in Native Gels Indicates Calcium-dependent Structural Changes of Neuronal Calcium Sensor Proteins", [1]).

Optical Coherence Tomography Scan Circle Location and Mean Retinal Nerve Fiber Layer Measurement Variability

PubMed Central

Gabriele, Michelle L.; Ishikawa, Hiroshi; Wollstein, Gadi; Bilonick, Richard A.; Townsend, Kelly A.; Kagemann, Larry; Wojtkowski, Maciej; Srinivasan, Vivek J.; Fujimoto, James G.; Duker, Jay S.; Schuman, Joel S.

2009-01-01

PURPOSE To investigate the effect on optical coherence tomography (OCT) retinal nerve fiber layer (RNFL) thickness measurements of varying the standard 3.4-mm-diameter circle location. METHODS The optic nerve head (ONH) region of 17 eyes of 17 healthy subjects was imaged with high-speed, ultrahigh-resolution OCT (hsUHR-OCT; 501 × 180 axial scans covering a 6 × 6-mm area; scan time, 3.84 seconds) for a comprehensive sampling. This method allows for systematic simulation of the variable circle placement effect. RNFL thickness was measured on this three-dimensional dataset by using a custom-designed software program. RNFL thickness was resampled along a 3.4-mm-diameter circle centered on the ONH, then along 3.4-mm circles shifted horizontally (x-shift), vertically (y-shift) and diagonally up to ±500 µm (at 100-µm intervals). Linear mixed-effects models were used to determine RNFL thickness as a function of the scan circle shift. A model for the distance between the two thickest measurements along the RNFL thickness circular profile (peak distance) was also calculated. RESULTS RNFL thickness tended to decrease with both positive and negative x- and y-shifts. The range of shifts that caused a decrease greater than the variability inherent to the commercial device was greater in both nasal and temporal quadrants than in the superior and inferior ones. The model for peak distance demonstrated that as the scan moves nasally, the RNFL peak distance increases, and as the circle moves temporally, the distance decreases. Vertical shifts had a minimal effect on peak distance. CONCLUSIONS The location of the OCT scan circle affects RNFL thickness measurements. Accurate registration of OCT scans is essential for measurement reproducibility and longitudinal examination (ClinicalTrials.gov number, NCT00286637). PMID:18515577

P-channel thin film transistors using reduced graphene oxide

NASA Astrophysics Data System (ADS)

Chakraborty, S.; Resmi, A. N.; Renuka Devi, P.; Jinesh, K. B.

2017-04-01

Chemically reduced graphene oxide (rGO) samples with various degrees of reduction were prepared using hydrazine hydrate as the reducing agent. Scanning tunnelling microscope imaging shows that rGO contains rows of randomly distributed patches of epoxy groups. The local density of states of the rGO samples were mapped with scanning tunnelling spectroscopy, which shows that the bandgap in rGO originates from the epoxide regions itself. The Fermi level of the epoxide regions is shifted towards the valence band, making rGO locally p-type and a range of bandgaps from 0-2.2 eV was observed in these regions. Thin film transistors were fabricated using rGO as the channel layer. The devices show excellent output characteristics with clear saturation and gate dependence. The transfer characteristics show that rGO behaves as a p-type semiconductor; the devices exhibit an on/off ratio of 104, with a low-bias hole mobility of 3.9 cm2 V-1 s-1.

Multiplatform Mobile Laser Scanning: Usability and Performance

PubMed Central

Kukko, Antero; Kaartinen, Harri; Hyyppä, Juha; Chen, Yuwei

2012-01-01

Mobile laser scanning is an emerging technology capable of capturing three-dimensional data from surrounding objects. With state-of-the-art sensors, the achieved point clouds capture object details with good accuracy and precision. Many of the applications involve civil engineering in urban areas, as well as traffic and other urban planning, all of which serve to make 3D city modeling probably the fastest growing market segment in this field. This article outlines multiplatform mobile laser scanning solutions such as vehicle- and trolley-operated urban area data acquisition, and boat-mounted equipment for fluvial environments. Moreover, we introduce a novel backpack version of mobile laser scanning equipment for surveying applications in the field of natural sciences where the requirements include precision and mobility in variable terrain conditions. In addition to presenting a technical description of the systems, we discuss the performance of the solutions in the light of various applications in the fields of urban mapping and modeling, fluvial geomorphology, snow-cover characterization, precision agriculture, and in monitoring the effects of climate change on permafrost landforms. The data performance of the mobile laser scanning approach is described by the results of an evaluation of the ROAMER on a permanent MLS test field. Furthermore, an in situ accuracy assessment using a field of spherical 3D targets for the newly-introduced Akhka backpack system is conducted and reported on.

Carrier recovery techniques on satellite mobile channels

NASA Technical Reports Server (NTRS)

Vucetic, B.; Du, J.

1990-01-01

An analytical method and a stored channel model were used to evaluate error performance of uncoded quadrature phase shift keying (QPSK) and M-ary phase shift keying (MPSK) trellis coded modulation (TCM) over shadowed satellite mobile channels in the presence of phase jitter for various carrier recovery techniques.

Application of Mobile Laser Scanning for Lean and Rapid Highway Maintenance and Construction

DOT National Transportation Integrated Search

2015-08-28

Mobile Terrestrial Laser Scanning (MTLS) is an emerging technology that combines the use of a laser scanner(s), the Global Navigation Satellite System (GNSS), and an Inertial Measurement Unit (IMU) on a vehicle to collect geo-spatial data. The overal...

Pole-Like Road Furniture Detection in Sparse and Unevenly Distributed Mobile Laser Scanning Data

NASA Astrophysics Data System (ADS)

Li, F.; Lehtomäki, M.; Oude Elberink, S.; Vosselman, G.; Puttonen, E.; Kukko, A.; Hyyppä, J.

2018-05-01

Pole-like road furniture detection received much attention due to its traffic functionality in recent years. In this paper, we develop a framework to detect pole-like road furniture from sparse mobile laser scanning data. The framework is carried out in four steps. The unorganised point cloud is first partitioned. Then above ground points are clustered and roughly classified after removing ground points. A slicing check in combination with cylinder masking is proposed to extract pole-like road furniture candidates. Pole-like road furniture are obtained after occlusion analysis in the last stage. The average completeness and correctness of pole-like road furniture in sparse and unevenly distributed mobile laser scanning data was above 0.83. It is comparable to the state of art in the field of pole-like road furniture detection in mobile laser scanning data of good quality and is potentially of practical use in the processing of point clouds collected by autonomous driving platforms.

An efficient scan diagnosis methodology according to scan failure mode for yield enhancement

NASA Astrophysics Data System (ADS)

Kim, Jung-Tae; Seo, Nam-Sik; Oh, Ghil-Geun; Kim, Dae-Gue; Lee, Kyu-Taek; Choi, Chi-Young; Kim, InSoo; Min, Hyoung Bok

2008-12-01

Yield has always been a driving consideration during fabrication of modern semiconductor industry. Statistically, the largest portion of wafer yield loss is defective scan failure. This paper presents efficient failure analysis methods for initial yield ramp up and ongoing product with scan diagnosis. Result of our analysis shows that more than 60% of the scan failure dies fall into the category of shift mode in the very deep submicron (VDSM) devices. However, localization of scan shift mode failure is very difficult in comparison to capture mode failure because it is caused by the malfunction of scan chain. Addressing the biggest challenge, we propose the most suitable analysis method according to scan failure mode (capture / shift) for yield enhancement. In the event of capture failure mode, this paper describes the method that integrates scan diagnosis flow and backside probing technology to obtain more accurate candidates. We also describe several unique techniques, such as bulk back-grinding solution, efficient backside probing and signal analysis method. Lastly, we introduce blocked chain analysis algorithm for efficient analysis of shift failure mode. In this paper, we contribute to enhancement of the yield as a result of the combination of two methods. We confirm the failure candidates with physical failure analysis (PFA) method. The direct feedback of the defective visualization is useful to mass-produce devices in a shorter time. The experimental data on mass products show that our method produces average reduction by 13.7% in defective SCAN & SRAM-BIST failure rates and by 18.2% in wafer yield rates.

Airport Analyses Informing New Mobility Shifts: Opportunities to Adapt Energy-Efficient Mobility Services and Infrastructure: Preprint

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

Henao, Alejandro; Sperling, Joshua; Young, Stanley E

An airport is one of the most important assets for a region's economic development and connectivity with the rest of the nation and world. Key aspects for investigation of energy efficient mobility at airports is ground transportation including factors ranging from the infrastructure, mobility services, and associated revenues. Data is critical to understand the maturity of new mobility services that can inform both cities and airports on how to respond, approach, manage, and adapt to the challenges, opportunities, and uncertainties associated with shifts in new mobility that influence human behavior, energy-efficiency and sustainability strategies. One key question identified in thismore » article is how quickly we are adapting to new mobility options - such as app-based ride-hailing and 'pooling' services - that may provide an opportunity to influence energy efficiency of ground transportation to and from airports. By starting with airports in the regions of four smart city finalists in the U.S. DOT Smart City Challenge, this paper focuses on key observability aspects of new modes and the rate of shifts in mobility patterns across San Francisco, Portland, Denver, and Kansas City. With the emerging megatrend of rising urbanization and rising air travel demand (a predicted doubling in demand by 2035), airports are expected to increasingly be on the front lines of adaptation to new transportation technology and services in terms of infrastructure investments, policies, and revenues. As airports have demonstrated the most potential and capability of any public institution to implement fees for new ride-hailing services, they are also a prime resource for collecting important data to help understand smart mobility transitions. Results focused on the shifts in revenues for ground transportation at airports offer one vantage point into the pace of transitions and adaptations in the new emerging mobility landscape, and present an opportunity to analyze how future adaptations could support more energy-efficient scenarios.« less

Effect of passage number on electrophoretic mobility distributions of cultured human embryonic kidney cells

NASA Technical Reports Server (NTRS)

Kunze, M. E.

1985-01-01

A systematic investigation was undertaken to characterize population shifts that occur in cultured human embryonic kidney cells as a function of passage number in vitro after original explantation. This approach to cell population shift analysis follows the suggestion of Mehreshi, Klein and Revesz that perturbed cell populations can be characterized by electrophoretic mobility distributions if they contain subpopulations with different electrophoretic mobilities. It was shown that this is the case with early passage cultured human embryo cells.

Brain Imaging Using Mobile CT: Current Status and Future Prospects.

PubMed

John, Seby; Stock, Sarah; Cerejo, Russell; Uchino, Ken; Winners, Stacey; Russman, Andrew; Masaryk, Thomas; Rasmussen, Peter; Hussain, Muhammad S

2016-01-01

Computed tomography (CT) is an invaluable tool in the diagnosis of many clinical conditions. Several advancements in biomedical engineering have achieved increase in speed, improvements in low-contrast detectability and image quality, and lower radiation. Portable or mobile CT constituted one such important advancement. It is especially useful in evaluating critically ill, intensive care unit patients by scanning them at bedside. A paradigm shift in utilization of mobile CT was its installation in ambulances for the management of acute stroke. Given the time sensitive nature of acute ischemic stroke, Mobile stroke units (MSU) were developed in Germany consisting of an ambulance equipped with a CT scanner, point of care laboratory system, along with teleradiological support. In a radical reconfiguration of stroke care, the MSU would bring the CT scanner to the stroke patient, without waiting for the patient at the emergency room. Two separate MSU projects in Saarland and Berlin demonstrated the safety and feasibility of this concept for prehospital stroke care, showing increased rate of intravenous thrombolysis and significant reduction in time to treatment compared to conventional care. MSU also improved the triage of patients to appropriate and specialized hospitals. Although multiple issues remain yet unanswered with the MSU concept including clinical outcome and cost-effectiveness, the MSU venture is visionary and enables delivery of life-saving and enhancing treatment for ischemic and hemorrhagic stroke. In this review, we discuss the development of mobile CT and its applications, with specific focus on its use in MSUs along with our institution's MSU experience. Copyright © 2015 by the American Society of Neuroimaging.

Spray deposition of highly transparent fluorine doped cadmium oxide thin films

NASA Astrophysics Data System (ADS)

Deokate, R. J.; Pawar, S. M.; Moholkar, A. V.; Sawant, V. S.; Pawar, C. A.; Bhosale, C. H.; Rajpure, K. Y.

2008-01-01

The cadmium oxide (CdO) and F:CdO films have been deposited by spray pyrolysis method using cadmium acetate and ammonium fluoride as precursors for Cd and F ions, respectively. The effect of temperature and F doping on the structural, morphological, optical and Hall effect properties of sprayed CdO thin films was investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), optical absorption and electrical measurement techniques. TGA and DTA studies, indicates the formation of CdO by decomposition of cadmium acetate after 250 °C. XRD patterns reveal that samples are polycrystalline with cubic structure and exhibits (2 0 0) preferential orientation. Considerable broading of (2 0 0) peak, simultaneous shifting of corresponding Bragg's angle have been observed with respect to F doping level. SEM and AFM show the heterogeneous distribution of cubical grains all over the substrate, which are randomly distributed. F doping shifts the optical gap along with the increase in the transparency of CdO films. The Hall effect measurement indicates that the resistivity and mobility decrease up to 4% F doping.

A comparison of mobile scanning to a total station survey at the I-35 and IA 92 interchange in Warren County, Iowa.

DOT National Transportation Integrated Search

2012-08-01

The purpose of this project was to investigate the potential for collecting and using data from mobile terrestrial laser scanning (MTLS) technology that would reduce the need for traditional survey methods for the development of highway improvement p...

77 FR 40637 - Honeywell International, Scanning and Mobility Division, Formerly Known as Hand Held Products...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-10

..., Scanning and Mobility Division, Formerly Known as Hand Held Products, Inc., Including On-Site Leased Workers From Manpower, Skaneatelles Falls, NY; Amended Certification Regarding Eligibility To Apply for...''), 19 U.S.C. 2273, the Department of Labor issued a Certification of Eligibility to Apply for Worker...

Barn owls maximize head rotations by a combination of yawing and rolling in functionally diverse regions of the neck.

PubMed

Krings, Markus; Nyakatura, John A; Boumans, Mark L L M; Fischer, Martin S; Wagner, Hermann

2017-07-01

Owls are known for their outstanding neck mobility: these birds can rotate their heads more than 270°. The anatomical basis of this extraordinary neck rotation ability is not well understood. We used X-ray fluoroscopy of living owls as well as forced neck rotations in dead specimens and computer tomographic (CT) reconstructions to study how the individual cervical joints contribute to head rotation in barn owls (Tyto furcata pratincola). The X-ray data showed the natural posture of the neck, and the reconstructions of the CT-scans provided the shapes of the individual vertebrae. Joint mobility was analyzed in a spherical coordinate system. The rotational capability was described as rotation about the yaw and roll axes. The analyses suggest a functional division of the cervical spine into several regions. Most importantly, an upper region shows high rolling and yawing capabilities. The mobility of the lower, more horizontally oriented joints of the cervical spine is restricted mainly to the roll axis. These rolling movements lead to lateral bending, effectively resulting in a side shift of the head compared with the trunk during large rotations. The joints in the middle of the cervical spine proved to contribute less to head rotation. The analysis of joint mobility demonstrated how owls might maximize horizontal head rotation by a specific and variable combination of yawing and rolling in functionally diverse regions of the neck. © 2017 Anatomical Society.

Dedicated mobile volumetric cone-beam computed tomography for human brain imaging: A phantom study.

PubMed

Ryu, Jong-Hyun; Kim, Tae-Hoon; Jeong, Chang-Won; Jun, Hong-Young; Heo, Dong-Woon; Lee, Jinseok; Kim, Kyong-Woo; Yoon, Kwon-Ha

2015-01-01

Mobile computed tomography (CT) with a cone-beam source is increasingly used in the clinical field. Mobile cone-beam CT (CBCT) has great merits; however, its clinical utility for brain imaging has been limited due to problems including scan time and image quality. The aim of this study was to develop a dedicated mobile volumetric CBCT for obtaining brain images, and to optimize the imaging protocol using a brain phantom. The mobile volumetric CBCT system was evaluated with regards to scan time and image quality, measured as signal-to-noise-ratio (SNR), contrast-to-noise-ratio (CNR), spatial resolution (10% MTF), and effective dose. Brain images were obtained using a CT phantom. The CT scan took 5.14 s at 360 projection views. SNR and CNR were 5.67 and 14.5 at 120 kV/10 mA. SNR and CNR values showed slight improvement as the x-ray voltage and current increased (p < 0.001). Effective dose and 10% MTF were 0.92 mSv and 360 μ m at 120 kV/10 mA. Various intracranial structures were clearly visible in the brain phantom images. Using this CBCT under optimal imaging acquisition conditions, it is possible to obtain human brain images with low radiation dose, reproducible image quality, and fast scan time.

Direct measurement of the Goos-Hänchen shift using a scanning quadrant detector and a polarization maintaining fiber.

PubMed

Yallapragada, Venkata Jayasurya; Mulay, Gajendra L; Rao, Ch N; Ravishankar, Ajith P; Achanta, Venu Gopal

2016-10-01

High precision measurements of optical beam shifts are important in various fields including sensing, atomic force microscopy, and measuring beam shifts at interfaces. Sub-micron shifts are generally measured by indirect techniques such as weak measurements. We demonstrate a straightforward and robust measurement scheme for the shift, based on a scanning quadrant photodiode (QPD) that is biased using a low noise electronic circuit. The shift is measured with respect to a reference beam that is co-propagating with the signal beam. Thus, the shift of the signal beam is readout directly as the difference between the x-intercepts of the QPD scan plot of the signal and reference beams versus the position of the detector. To measure the beam shift, we use polarization multiplexing scheme where the p-polarized signal and s-polarized reference beams are modulated at two different frequencies and co-launched into a polarization-maintaining fiber. Both the signal and reference beam positions are readout by two lock-in amplifiers simultaneously. In order to demonstrate the utility of this method, we perform a direct measurement of Goos-Hänchen shift of a beam that is reflected from a plane gold surface. Accuracy of 150 nm is achieved using this technique.

Direct measurement of the Goos-Hänchen shift using a scanning quadrant detector and a polarization maintaining fiber

NASA Astrophysics Data System (ADS)

Yallapragada, Venkata Jayasurya; Mulay, Gajendra L.; Rao, Ch. N.; Ravishankar, Ajith P.; Achanta, Venu Gopal

2016-10-01

High precision measurements of optical beam shifts are important in various fields including sensing, atomic force microscopy, and measuring beam shifts at interfaces. Sub-micron shifts are generally measured by indirect techniques such as weak measurements. We demonstrate a straightforward and robust measurement scheme for the shift, based on a scanning quadrant photodiode (QPD) that is biased using a low noise electronic circuit. The shift is measured with respect to a reference beam that is co-propagating with the signal beam. Thus, the shift of the signal beam is readout directly as the difference between the x-intercepts of the QPD scan plot of the signal and reference beams versus the position of the detector. To measure the beam shift, we use polarization multiplexing scheme where the p-polarized signal and s-polarized reference beams are modulated at two different frequencies and co-launched into a polarization-maintaining fiber. Both the signal and reference beam positions are readout by two lock-in amplifiers simultaneously. In order to demonstrate the utility of this method, we perform a direct measurement of Goos-Hänchen shift of a beam that is reflected from a plane gold surface. Accuracy of 150 nm is achieved using this technique.

Using Electrophoretic Mobility Shift Assays to Measure Equilibrium Dissociation Constants: GAL4-p53 Binding DNA as a Model System

ERIC Educational Resources Information Center

Heffler, Michael A.; Walters, Ryan D.; Kugel, Jennifer F.

2012-01-01

An undergraduate biochemistry laboratory experiment is described that will teach students the practical and theoretical considerations for measuring the equilibrium dissociation constant (K[subscript D]) for a protein/DNA interaction using electrophoretic mobility shift assays (EMSAs). An EMSA monitors the migration of DNA through a native gel;…

Retrieval Algorithms for Road Surface Modelling Using Laser-Based Mobile Mapping.

PubMed

Jaakkola, Anttoni; Hyyppä, Juha; Hyyppä, Hannu; Kukko, Antero

2008-09-01

Automated processing of the data provided by a laser-based mobile mapping system will be a necessity due to the huge amount of data produced. In the future, vehiclebased laser scanning, here called mobile mapping, should see considerable use for road environment modelling. Since the geometry of the scanning and point density is different from airborne laser scanning, new algorithms are needed for information extraction. In this paper, we propose automatic methods for classifying the road marking and kerbstone points and modelling the road surface as a triangulated irregular network. On the basis of experimental tests, the mean classification accuracies obtained using automatic method for lines, zebra crossings and kerbstones were 80.6%, 92.3% and 79.7%, respectively.

Modems for emerging digital cellular-mobile radio system

NASA Technical Reports Server (NTRS)

Feher, Kamilo

1991-01-01

Digital modem techniques for emerging digital cellular telecommunications-mobile radio system applications are described and analyzed. In particular, theoretical performance, experimental results, principles of operation, and various architectures of pi/4-QPSK (pi/4-shifted coherent or differential QPSK) modems for second-generation US digital cellular radio system applications are presented. The spectral/power efficiency and performance of the pi/4-QPSK modems (American and Japanese digital cellular emerging standards) are studied and briefly compared to GMSK (Gaussian minimum-shift keying) modems (proposed for European DECT and GSM cellular standards). Improved filtering strategies and digital pilot-aided (digital channel sounding) techniques are also considered for pi/4-QPSK and other digital modems. These techniques could significantly improve the performance of digital cellular and other digital land mobile and satellite mobile radio systems. More spectrally efficient modem trends for future cellular/mobile (land mobile) and satellite communication systems applications are also highlighted.

Shifting Patterns of Student Mobility in Asia

ERIC Educational Resources Information Center

Chan, Sheng-Ju

2012-01-01

During the past decade, Asia--traditionally one of the largest exporters of mobile students--has experienced major changes in student mobility within higher education. As the worldwide competition for international students has escalated, many Asian countries have adopted a wide range of mechanisms and strategies in facilitating student mobility.…

Boresight alignment method for mobile laser scanning systems

NASA Astrophysics Data System (ADS)

Rieger, P.; Studnicka, N.; Pfennigbauer, M.; Zach, G.

2010-06-01

Mobile laser scanning (MLS) is the latest approach towards fast and cost-efficient acquisition of 3-dimensional spatial data. Accurately evaluating the boresight alignment in MLS systems is an obvious necessity. However, recent systems available on the market may lack of suitable and efficient practical workflows on how to perform this calibration. This paper discusses an innovative method for accurately determining the boresight alignment of MLS systems by employing 3D laser scanners. Scanning objects using a 3D laser scanner operating in a 2D line-scan mode from various different runs and scan directions provides valuable scan data for determining the angular alignment between inertial measurement unit and laser scanner. Field data is presented demonstrating the final accuracy of the calibration and the high quality of the point cloud acquired during an MLS campaign.

Omni-Directional Scanning Localization Method of a Mobile Robot Based on Ultrasonic Sensors.

PubMed

Mu, Wei-Yi; Zhang, Guang-Peng; Huang, Yu-Mei; Yang, Xin-Gang; Liu, Hong-Yan; Yan, Wen

2016-12-20

Improved ranging accuracy is obtained by the development of a novel ultrasonic sensor ranging algorithm, unlike the conventional ranging algorithm, which considers the divergence angle and the incidence angle of the ultrasonic sensor synchronously. An ultrasonic sensor scanning method is developed based on this algorithm for the recognition of an inclined plate and to obtain the localization of the ultrasonic sensor relative to the inclined plate reference frame. The ultrasonic sensor scanning method is then leveraged for the omni-directional localization of a mobile robot, where the ultrasonic sensors are installed on a mobile robot and follow the spin of the robot, the inclined plate is recognized and the position and posture of the robot are acquired with respect to the coordinate system of the inclined plate, realizing the localization of the robot. Finally, the localization method is implemented into an omni-directional scanning localization experiment with the independently researched and developed mobile robot. Localization accuracies of up to ±3.33 mm for the front, up to ±6.21 for the lateral and up to ±0.20° for the posture are obtained, verifying the correctness and effectiveness of the proposed localization method.

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

Tournadre, Grégoire de, E-mail: gregoire.de-tournadre@univ-reims.fr; Reisdorffer, Frédéric; Simonetti, Olivier

A scanning surface potential measurement technique suited for thin-film devices operating under high voltages is reported. A commercial atomic force microscope has been customized to enable a feedback-controlled and secure surface potential measurement based on phase-shift detection under ambient conditions. Measurements of the local potential profile along the channel of bottom-gate organic thin-film transistors (TFTs) are shown to be useful to disentangle the contributions from the channel and contacts to the device performance. Intrinsic contact current-voltage characteristics have been measured on bottom-gate, top-contact (staggered) TFTs based on the small-molecule semiconductor dinaphtho[2,3-b:2′,3-f]thieno[3,2-b]thiophene (DNTT) and on bottom-gate, bottom-contact (coplanar) TFTs based onmore » the semiconducting polymer polytriarylamine (PTAA). Injection has been found to be linear in the staggered DNTT TFTs and nonlinear in the coplanar PTAA TFTs. In both types of TFT, the injection efficiency has been found to improve with increasing gate bias in the accumulation regime. Contact resistances as low as 130 Ω cm have been measured in the DNTT TFTs. A method that eliminates the influence of bias-stress-induced threshold-voltage shifts when measuring the local charge-carrier mobility in the channel is also introduced, and intrinsic channel mobilities of 1.5 cm{sup 2} V{sup −1} s{sup −1} and 1.1 × 10{sup −3} cm{sup 2} V{sup −1} s{sup −1} have been determined for DNTT and PTAA. In both semiconductors, the mobility has been found to be constant with respect to the gate bias. Despite its simplicity, the Kelvin probe force microscopy method reported here provides robust and accurate surface potential measurements on thin-film devices under operation and thus paves the way towards more extensive studies of particular interest in emerging fields of solid-state electronics.« less

SU-F-J-188: Clinical Implementation of in Room Mobile CT for Image Guided Proton Therapy

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

Li, H; Wu, R; Poenisch, F

Purpose: To implement soft-tissue image-guided proton therapy using inroom mobile CT. Methods: Anthropomorphic phantom was first used to determine the setup accuracy using in- room mobile CT. Laser and bbs were used for the initial setup (marked isocenter). CT data was then acquired with in-room mobile CT (daily CT). The shift between the marked isocenter and the planned isocenter (final isocenter) was determined from the daily CT using in-house Computer Assisted Targeting (CAT) software. Orthogonal DRRs of the day was also generated from the daily CT. The phantom was then transferred on the treatment couch top to the treatment machinemore » using a transportation system, and again aligned to the marked isocenter. Couch shifts were made to align the phantom to the final isocenter using the shifts as determined using the CAT software, and verified using orthogonal X-ray images with the daily DRRs. Results: Phantom data suggests that following the setup procedure as described above, targeting accuracy could be within 1 mm. Patient data are being acquired and analyzed. Conclusion: In-room mobile CT is capable of providing soft-tissue image-guided proton therapy.« less

Using advertisement light-panel and CMOS image sensor with frequency-shift-keying for visible light communication.

PubMed

Chow, Chi-Wai; Shiu, Ruei-Jie; Liu, Yen-Chun; Liao, Xin-Lan; Lin, Kun-Hsien; Wang, Yi-Chang; Chen, Yi-Yuan

2018-05-14

A frequency-shift-keying (FSK) visible light communication (VLC) system is proposed and demonstrated using advertisement light-panel as transmitter and mobile-phone image sensor as receiver. The developed application program (APP) in mobile-phone can retrieve the rolling shutter effect (RSE) pattern produced by the FSK VLC signal effectively. Here, we also define noise-ratio value (NRV) to evaluate the contrast of different advertisements displayed on the light-panel. Both mobile-phones under test can achieve success rate > 96% even when the transmission distance is up to 200 cm and the NRVs are low.

A Critical Review of 13 Years of Mobile Game-Based Learning

ERIC Educational Resources Information Center

Giannakas, Filippos; Kambourakis, Georgios; Papasalouros, Andreas; Gritzalis, Stefanos

2018-01-01

With the increasing popularity of smartphones and tablets, game-based learning (GBL) is undergoing a rapid shift to mobile platforms. This transformation is driven by mobility, wireless interfaces, and built-in sensors that these smart devices offer in order to enable blended and context-sensitive mobile learning (m-Learning) activities. Thus,…

An Introduction to Current Trends and Benefits of Mobile Wireless Technology Use in Higher Education

ERIC Educational Resources Information Center

Kim, Sang Hyun; Mims, Clif; Holmes, Kerry P.

2006-01-01

The development of mobile wireless technologies has generated a considerable amount of excitement among practitioners and academics because it results in shifting the academic environment from traditional settings to mobile learning (m-learning) settings. Increasing numbers of institutions of higher education offer courses using mobile wireless…

UV damage-specific DNA-binding protein in xeroderma pigmentosum complementation group E

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

Kataoka, H.; Fujiwara, Y.

1991-03-29

The gel mobility shift assay method revealed a specifically ultraviolet (UV) damage recognizing, DNA-binding protein in nuclear extracts of normal human cells. The resulted DNA/protein complexes caused the two retarded mobility shifts. Four xeroderma pigmentosum complementation group E (XPE) fibroblast strains derived from unrelated Japanese families were not deficient in such a DNA damage recognition/binding protein because of the normal complex formation and gel mobility shifts, although we confirmed the reported lack of the protein in the European XPE (XP2RO and XP3RO) cells. Thus, the absence of this binding protein is not always commonly observed in all the XPE strains,more » and the partially repair-deficient and intermediately UV-hypersensitive phenotype of XPE cells are much similar whether or not they lack the protein.« less

Local 2D-2D tunneling in high mobility electron systems

NASA Astrophysics Data System (ADS)

Pelliccione, Matthew; Sciambi, Adam; Bartel, John; Goldhaber-Gordon, David; Pfeiffer, Loren; West, Ken; Lilly, Michael; Bank, Seth; Gossard, Arthur

2012-02-01

Many scanning probe techniques have been utilized in recent years to measure local properties of high mobility two-dimensional (2D) electron systems in GaAs. However, most techniques lack the ability to tunnel into the buried 2D system and measure local spectroscopic information. We report scanning gate measurements on a bilayer GaAs/AlGaAs heterostructure that allows for a local modulation of tunneling between two 2D electron layers. We call this technique Virtual Scanning Tunneling Microscopy (VSTM) [1,2] as the influence of the scanning gate is analogous to an STM tip, except at a GaAs/AlGaAs interface instead of a surface. We will discuss the spectroscopic capabilities of the technique, and show preliminary results of measurements on a high mobility 2D electron system.[1] A. Sciambi, M. Pelliccione et al., Appl. Phys. Lett. 97, 132103 (2010).[2] A. Sciambi, M. Pelliccione et al., Phys. Rev. B 84, 085301 (2011).

Radial microstrip slotline feed network for circular mobile communications array

NASA Technical Reports Server (NTRS)

Simons, Rainee N.; Kelly, Eron S.; Lee, Richard Q.; Taub, Susan R.

1994-01-01

In mobile and satellite communications there is a need for low cost and low profile antennas which have a toroidal pattern. Antennas that have been developed for mobile communications include a L-Band electronically steered stripline phased array, a Ka-Band mechanically steered elliptical reflector antenna and a Ka-Band printed dipole. In addition, a L-Band mechanically steered microstrip array, a L-Band microstrip phased array tracking antenna for mounting on a car roof and an X-Band radial line slotted waveguide antenna have been demonstrated. In the above electronically scanned printed arrays, the individual element radiates normally to the plane of the array and hence require a phase shifter to scan the beam towards the horizon. Scanning in the azimuth is by mechanical or electronic steering. An alternate approach is to mount microstrip patch radiators on the surface of a cone to achieve the required elevation angle. The array then scans in the azimuth by beam switching.

Effect of UV/ozone treatment on polystyrene dielectric and its application on organic field-effect transistors

PubMed Central

2014-01-01

The influence of UV/ozone treatment on the property of polystyrene (PS) dielectric surface was investigated, and pentacene organic field-effect transistors (OFETs) based on the treated dielectric was fabricated. The dielectric and pentacene active layers were characterized by atomic force microscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. The results showed that, at short UVO exposure time (<10 s), the chemical composition of PS dielectric surface remained the same. While at long UVO exposure time (>60 s), new chemical groups, including alcohol/ether, carbonyl, and carboxyl/ester groups, were formed. By adjusting the UVO exposure time to 5 s, the hole mobility of the OFETs increased to 0.52 cm2/Vs, and the threshold voltage was positively shifted to -12 V. While the time of UVO treatment exceeded 30 s, the mobility started to shrink, and the off-current was enlarged. These results indicate that, as a simple surface treatment method, UVO treatment could quantitatively modulate the property of PS dielectric surface by controlling the exposure time, and thus, pioneered a new way to modulate the characteristics of organic electronic devices. PMID:25258603

Land-Based Mobile Laser Scanning Systems: a Review

NASA Astrophysics Data System (ADS)

Puente, I.; González-Jorge, H.; Arias, P.; Armesto, J.

2011-09-01

Mobile mapping has been using various photogrammetric techniques for many years. In recent years, there has been an increase in the number of mobile mapping systems using laser scanners available in the market, partially because of the improvement in GNSS/INS performance for direct georeferencing. In this article, some of the most important land-based mobile laser scanning (MLS) systems are reviewed. Firstly, the main characteristics of MLS systems vs. airborne (ALS) and terrestrial laser scanning (TLS) systems are compared. Secondly, a short overview of the mobile mapping technology is also provided so that the reader can fully grasp the complexity and operation of these devices. As we put forward in this paper, a comparison of different systems is briefly carried out regarding specifications provided by the manufacturers. Focuses on the current research are also addressed with emphasis on the practical applications of these systems. Most of them have been utilized for data collection on road infrastructures or building façades. This article shows that MLS technology is nowadays well established and proven, since the demand has grown to the point that there are several systems suppliers offering their products to satisfy this particular market.

Semantic Labelling of Road Furniture in Mobile Laser Scanning Data

NASA Astrophysics Data System (ADS)

Li, F.; Oude Elberink, S.; Vosselman, G.

2017-09-01

Road furniture semantic labelling is vital for large scale mapping and autonomous driving systems. Much research has been investigated on road furniture interpretation in both 2D images and 3D point clouds. Precise interpretation of road furniture in mobile laser scanning data still remains unexplored. In this paper, a novel method is proposed to interpret road furniture based on their logical relations and functionalities. Our work represents the most detailed interpretation of road furniture in mobile laser scanning data. 93.3 % of poles are correctly extracted and all of them are correctly recognised. 94.3 % of street light heads are detected and 76.9 % of them are correctly identified. Despite errors arising from the recognition of other components, our framework provides a promising solution to automatically map road furniture at a detailed level in urban environments.

Mating patterns and pollinator mobility are critical traits in forest fragmentation genetics

PubMed Central

Breed, M F; Ottewell, K M; Gardner, M G; Marklund, M H K; Dormontt, E E; Lowe, A J

2015-01-01

Most woody plants are animal-pollinated, but the global problem of habitat fragmentation is changing the pollination dynamics. Consequently, the genetic diversity and fitness of the progeny of animal-pollinated woody plants sired in fragmented landscapes tend to decline due to shifts in plant-mating patterns (for example, reduced outcrossing rate, pollen diversity). However, the magnitude of this mating-pattern shift should theoretically be a function of pollinator mobility. We first test this hypothesis by exploring the mating patterns of three ecologically divergent eucalypts sampled across a habitat fragmentation gradient in southern Australia. We demonstrate increased selfing and decreased pollen diversity with increased fragmentation for two small-insect-pollinated eucalypts, but no such relationship for the mobile-bird-pollinated eucalypt. In a meta-analysis, we then show that fragmentation generally does increase selfing rates and decrease pollen diversity, and that more mobile pollinators tended to dampen these mating-pattern shifts. Together, our findings support the premise that variation in pollinator form contributes to the diversity of mating-pattern responses to habitat fragmentation. PMID:24002239

Automatic 3D relief acquisition and georeferencing of road sides by low-cost on-motion SfM

NASA Astrophysics Data System (ADS)

Voumard, Jérémie; Bornemann, Perrick; Malet, Jean-Philippe; Derron, Marc-Henri; Jaboyedoff, Michel

2017-04-01

3D terrain relief acquisition is important for a large part of geosciences. Several methods have been developed to digitize terrains, such as total station, LiDAR, GNSS or photogrammetry. To digitize road (or rail tracks) sides on long sections, mobile spatial imaging system or UAV are commonly used. In this project, we compare a still fairly new method -the SfM on-motion technics- with some traditional technics of terrain digitizing (terrestrial laser scanning, traditional SfM, UAS imaging solutions, GNSS surveying systems and total stations). The SfM on-motion technics generates 3D spatial data by photogrammetric processing of images taken from a moving vehicle. Our mobile system consists of six action cameras placed on a vehicle. Four fisheye cameras mounted on a mast on the vehicle roof are placed at 3.2 meters above the ground. Three of them have a GNNS chip providing geotagged images. Two pictures were acquired every second by each camera. 4K resolution fisheye videos were also used to extract 8.3M not geotagged pictures. All these pictures are then processed with the Agisoft PhotoScan Professional software. Results from the SfM on-motion technics are compared with results from classical SfM photogrammetry on a 500 meters long alpine track. They were also compared with mobile laser scanning data on the same road section. First results seem to indicate that slope structures are well observable up to decimetric accuracy. For the georeferencing, the planimetric (XY) accuracy of few meters is much better than the altimetric (Z) accuracy. There is indeed a Z coordinate shift of few tens of meters between GoPro cameras and Garmin camera. This makes necessary to give a greater freedom to altimetric coordinates in the processing software. Benefits of this low-cost SfM on-motion method are: 1) a simple setup to use in the field (easy to switch between vehicle types as car, train, bike, etc.), 2) a low cost and 3) an automatic georeferencing of 3D points clouds. Main disadvantages are: 1) results are less accurate than those from LiDAR system, 2) a heavy images processing and 3) a short distance of acquisition.

A portable intra-oral scanner based on sinusoidal pattern of fast phase-shifting

NASA Astrophysics Data System (ADS)

Jan, Chia-Ming; Lin, Ying-Chieh

2016-03-01

This paper presented our current research about the intra-oral scanner made by MIRDC. Utilizing the sinusoidal pattern for fast phase-shifting technique to deal with 3D digitalization of human dental surface profile, the development of pseudo-phase shifting digital projection can easily achieve one type of full-field scanning instead of the common technique of the laser line scanning. Based on traditional Moiré method, we adopt projecting fringes and retrieve phase reconstruction to forward phase unwrapping. The phase difference between the plane and object can be exactly calculated from the desired fringe images, and the surface profile of object was probably reconstructed by using the phase differences information directly. According to our algorithm of space mapping between projections and capturing orientation exchange of our intra-oral scanning configuration, the system we made certainly can be proved to achieve the required accuracy of +/-10μm to deal with intra-oral scanning on the basis of utilizing active triangulation method. The final purpose aimed to the scanning of object surface profile with its size about 10x10x10mm3.

An evaluation of transport mode shift policies on transport-related physical activity through simulations based on random forests.

PubMed

Brondeel, Ruben; Kestens, Yan; Chaix, Basile

2017-10-23

Physical inactivity is widely recognized as one of the leading causes of mortality, and transport accounts for a large part of people's daily physical activity. This study develops a simulation approach to evaluate the impact of the Ile-de-France Urban Mobility Plan (2010-2020) on physical activity, under the hypothesis that the intended transport mode shifts are realized. Based on the Global Transport Survey (2010, n = 21,332) and on the RECORD GPS Study (2012-2013, n = 229) from the French capital region of Paris (Ile-de-France), a simulation method was designed and tested. The simulation method used accelerometer data and random forest models to predict the impact of the transport mode shifts anticipated in the Mobility Plan on transport-related moderate-to-vigorous physical activity (T-MVPA). The transport mode shifts include less private motorized trips in favor of more public transport, walking, and biking trips. The simulation model indicated a mean predicted increase of 2 min per day of T-MVPA, in case the intended transport mode shifts in the Ile-de-France Urban Mobility Plan were realized. The positive effect of the transport mode shifts on T-MVPA would, however, be larger for people with a higher level of education. This heterogeneity in the positive effect would further increase the existing inequality in transport-related physical activity by educational level. The method presented in this paper showed a significant increase in transport-related physical activity in case the intended mode shifts in the Ile-de-France Urban Mobility Plan were realized. This simulation method could be applied on other important health outcomes, such as exposure to noise or air pollution, making it a useful tool to anticipate the health impact of transport interventions or policies.

Science Projects | Akron-Summit County Public Library

Science.gov Websites

Resources Suggest a Purchase Hours & Locations Main Library Mobile Services Ellet Fairlawn-Bath Training Print/Scan/Fax/Copy Assistive Services Borrower Services Library Computers Meeting Rooms Mobile ; Notable Student Resources Suggest a Purchase Hours & Locations Main Library Mobile Services Ellet

Miniaturized NIR scanning grating spectrometer for use in mobile phones

NASA Astrophysics Data System (ADS)

Knobbe, Jens; Pügner, Tino; Grüger, Heinrich

2016-05-01

An extremely miniaturized scanning grating spectrometer at the size of a sugar cube has been developed at Fraunhofer IPMS. To meet the requirements for the integration into a mobile phone a new system approach has been pursued. The key component within the system is a silicon-based deflectable diffraction grating with an integrated driving mechanism. A first sample of the new spectrometer was built and characterized. It was found to have a spectral range from 950 nm to 1900 nm at a resolution of 10 nm. The results show that the performance of the new MEMS spectrometer is in good agreement with the requirements for mobile phone integration.

[Optimal scan parameters for a method of k-space trajectory (radial scan method) in evaluation of carotid plaque characteristics].

PubMed

Nakamura, Manami; Makabe, Takeshi; Tezuka, Hideomi; Miura, Takahiro; Umemura, Takuma; Sugimori, Hiroyuki; Sakata, Motomichi

2013-04-01

The purpose of this study was to optimize scan parameters for evaluation of carotid plaque characteristics by k-space trajectory (radial scan method), using a custom-made carotid plaque phantom. The phantom was composed of simulated sternocleidomastoid muscle and four types of carotid plaque. The effect of chemical shift artifact was compared using T1 weighted images (T1WI) of the phantom obtained with and without fat suppression, and using two types of k-space trajectory (the radial scan method and the Cartesian method). The ratio of signal intensity of simulated sternocleidomastoid muscle to the signal intensity of hematoma, blood (including heparin), lard, and mayonnaise was compared among various repetition times (TR) using T1WI and T2 weighted imaging (T2WI). In terms of chemical shift artifacts, image quality was improved using fat suppression for both the radial scan and Cartesian methods. In terms of signal ratio, the highest values were obtained for the radial scan method with TR of 500 ms for T1WI, and TR of 3000 ms for T2WI. For evaluation of carotid plaque characteristics using the radial scan method, chemical shift artifacts were reduced with fat suppression. Signal ratio was improved by optimizing the TR settings for T1WI and T2WI. These results suggest the potential for using magnetic resonance imaging for detailed evaluation of carotid plaque.

Extended investigation into continuous laser scanning of underground mine workings by means of Landis inertial navigation system

NASA Astrophysics Data System (ADS)

Belyaev, E. N.

2017-10-01

The paper investigates the method of applying mobile scanning systems (MSSs) with inertial navigators in the underground conditions for carrying out the surveying tasks. The available mobile laser scanning systems cannot be used in the underground environment since Global Positioning System (GPS) signals cannot be received in mines. This signal not only is necessary for space positioning, but also operates as the main corrective signal for the primary navigation system - the inertial navigation system. The idea of the method described in this paper consists in using MSSs with a different correction of the inertial system than GPS is.

Insertion and deletion mutations in the dinucleotide repeat region of the Norrie disease gene in patients with advanced retinopathy of prematurity.

PubMed

Hiraoka, M; Berinstein, D M; Trese, M T; Shastry, B S

2001-01-01

Retinopathy of prematurity (ROP) is a leading cause of blindness in premature children. It is a multifactorial disorder which causes fibrovascular tissue changes that affect the retina in low birth-weight and short gestational age infants. To determine the prevalence of Norrie disease (ND) gene mutations, clinical examination and molecular genetic analyses were performed in 100 pre-term babies of different ethnic backgrounds who developed advanced ROP. The leukocyte DNA was extracted, amplified by the polymerase chain reaction (PCR), and analyzed by single-strand conformation polymorphism (SSCP), G/T and C/A scanning, and by DNA sequencing. All three exons, including splice sites and the 3'-untranslated region, were screened. Of the 100 patients analyzed, 2 patients with advanced ROP showed a mobility shift in the DNA. In 1 patient, this mobility shift was caused by the insertion of an additional 12-bp CT repeat in exon 1, and in the second patient, there was a 14-bp deletion in the same exon of the ND gene, as evidenced by direct sequencing of the amplified products. Similar analyses of exons 2 and 3 and the 3'-untranslated region failed to detect additional mutations in the gene. None of the 130 normal, unrelated controls revealed similar changes. Taking into account the above results, as well as those of other studies, it appears that the ND gene mutations can account for 3% of cases of advanced ROP. Although the ND gene is not frequently involved in advanced ROP, the present large-scale study further supports the hypothesis that genetic influences may play an important role in the development of severe ROP in some premature infants.

Russian Snap Military Exercise in March of 2015; What Implications did this Exercise Have

DTIC Science & Technology

2017-06-09

Russia can mobilize rapidly the nation for war, shift substantial forces in its interior to meet any threat, and that Russia is willing to use military...Further, it demonstrates to any observer that Russia can mobilize rapidly the nation for war, shift substantial forces in its interior to meet any...the steps of qualitative research method in a class on Advanced Research Methods, September 12, 2016. 65 Robert K. Yin, Case Study Research: Design

Demonstrating Interactions of Transcription Factors with DNA by Electrophoretic Mobility Shift Assay.

PubMed

Yousaf, Nasim; Gould, David

2017-01-01

Confirming the binding of a transcription factor with a particular DNA sequence may be important in characterizing interactions with a synthetic promoter. Electrophoretic mobility shift assay is a powerful approach to demonstrate the specific DNA sequence that is bound by a transcription factor and also to confirm the specific transcription factor involved in the interaction. In this chapter we describe a method we have successfully used to demonstrate interactions of endogenous transcription factors with sequences derived from endogenous and synthetic promoters.

Exploiting chromatic aberration to spectrally encode depth in reflectance confocal microscopy

NASA Astrophysics Data System (ADS)

Carrasco-Zevallos, Oscar; Shelton, Ryan L.; Olsovsky, Cory; Saldua, Meagan; Applegate, Brian E.; Maitland, Kristen C.

2011-06-01

We present chromatic confocal microscopy as a technique to axially scan the sample by spectrally encoding depth information to avoid mechanical scanning of the lens or sample. We have achieved an 800 μm focal shift over a range of 680-1080 nm using a hyperchromat lens as the imaging lens. A more complex system that incorporates a water immersion objective to improve axial resolution was built and tested. We determined that increasing objective magnification decreases chromatic shift while improving axial resolution. Furthermore, collimating after the hyperchromat at longer wavelengths yields an increase in focal shift.

Harmonisation of nanoparticle concentration measurements using GRIMM and TSI scanning mobility particle sizers

NASA Astrophysics Data System (ADS)

Joshi, Manish; Sapra, B. K.; Khan, Arshad; Tripathi, S. N.; Shamjad, P. M.; Gupta, Tarun; Mayya, Y. S.

2012-12-01

Regional studies focusing on the role of atmospheric nanoparticles in climate change have gained impetus in the last decade. Several multi-institutional studies involving measurement of nanoparticles with several kinds of instruments are on the rise. It is important to harmonize these measurements as the instruments may work on different techniques or principles and are developed by different manufacturers. Scanning mobility particle sizers (SMPS) are often used to measure size distribution of nanoparticles in the airborne phase. Two such commercially available instruments namely, GRIMM and TSI-SMPS have been compared for ambient and laboratory generated conditions. A stand-alone condensation particle counter (CPC) of TSI make was used as a reference for particle concentration measurements. The consistency of the results in terms of mean size and geometric standard deviation was seen to be excellent for both the SMPSs, with GRIMM always showing slightly (approximately 10 %) lower mean size. The integrated number concentration from GRIMM-SMPS was seen to be closer to stand-alone reference CPC compared to TSI-SMPS, for an ambient overnight comparison. However, a concentration-dependent response, i.e. the variations between the two instruments increasing with the concentration, was observed and possible reasons for this have been suggested. A separate experiment was performed for studying the modifying effect of diffusion dryer and sheath air dryer on the measured aerosol size spectra. A significant hygroscopic growth was noted when diffusion dryer was attached to one of the SMPS. The introduction of sheath air dryer in GRIMM-SMPS produced a significant shift towards lower mean size. These results have been compared and discussed with the recent inter-comparison results to strengthen and harmonize the measurement protocols.

Fluorescence correlation spectroscopy: novel variations of an established technique.

PubMed

Haustein, Elke; Schwille, Petra

2007-01-01

Fluorescence correlation spectroscopy (FCS) is one of the major biophysical techniques used for unraveling molecular interactions in vitro and in vivo. It allows minimally invasive study of dynamic processes in biological specimens with extremely high temporal and spatial resolution. By recording and correlating the fluorescence fluctuations of single labeled molecules through the exciting laser beam, FCS gives information on molecular mobility and photophysical and photochemical reactions. By using dual-color fluorescence cross-correlation, highly specific binding studies can be performed. These have been extended to four reaction partners accessible by multicolor applications. Alternative detection schemes shift accessible time frames to slower processes (e.g., scanning FCS) or higher concentrations (e.g., TIR-FCS). Despite its long tradition, FCS is by no means dated. Rather, it has proven to be a highly versatile technique that can easily be adapted to solve specific biological questions, and it continues to find exciting applications in biology and medicine.

Potassium and water coadsorption on TiO 2(110): OH-induced anchoring of potassium and the generation of single-site catalysts

DOE PAGES

Grinter, David C.; R. Remesal, Elena; Luo, Si; ...

2016-09-15

Potassium deposition on TiO 2(110) results in reduction of the substrate and formation of loosely bound potassium species that can move easily on the oxide surface to promote catalytic activity. The results of density functional calculations predict a large adsorption energy (~3.2 eV) with a small barrier (~0.25 eV) for diffusion on the oxide surface. In scanning tunneling microscopy images, the adsorbed alkali atoms lose their mobility when in contact with surface OH groups. Furthermore, K adatoms facilitate the dissociation of water on the titania surface. Lastly, the K–(OH) species generated are good sites for the binding of gold clustersmore » on the TiO 2(110) surface, producing Au/K/TiO 2(110) systems with high activity for the water–gas shift.« less

High-speed optical coherence tomography using fiberoptic acousto-optic phase modulation

NASA Astrophysics Data System (ADS)

Xie, Tuqiang; Wang, Zhenguo; Pan, Yingtian

2003-12-01

We report a new rapid-scanning optical delay device suitable for high-speed optical coherence tomography (OCT) in which an acousto-optic modulator (AOM) is used to independently modulate the Doppler frequency shift of the reference light beam for optical heterodyne detection. Experimental results show that the fluctuation of the measured Doppler frequency shift is less than +/-0.2% over 95% duty cycle of OCT imaging, thus allowing for enhanced signal-to-noise ratio of optical heterodyne detection. The increased Doppler frequency shift by AOM also permits complete envelop demodulation without the compromise of reducing axial resolution; if used with a resonant rapid-scanning optical delay, it will permit high-performance real-time OCT imaging. Potentially, this new rapid-scanning optical delay device will improve the performance of high-speed Doppler OCT techniques.

The Research Imagination in a World on the Move

ERIC Educational Resources Information Center

Kenway, Jane; Fahey, Johannah

2006-01-01

This paper focuses on the shifting terrain of mobile researchers beginning with an overview of research and research policy on "brain mobility", and then discussing what we call their optical illusions/delusions. Subsequently, our main purpose is to elaborate on a line of inquiry that offers richer notions of researcher mobility, connectivity and…

Z-scan theory for nonlocal nonlinear media with simultaneous nonlinear refraction and nonlinear absorption.

PubMed

Rashidian Vaziri, Mohammad Reza

2013-07-10

In this paper, the Z-scan theory for nonlocal nonlinear media has been further developed when nonlinear absorption and nonlinear refraction appear simultaneously. To this end, the nonlinear photoinduced phase shift between the impinging and outgoing Gaussian beams from a nonlocal nonlinear sample has been generalized. It is shown that this kind of phase shift will reduce correctly to its known counterpart for the case of pure refractive nonlinearity. Using this generalized form of phase shift, the basic formulas for closed- and open-aperture beam transmittances in the far field have been provided, and a simple procedure for interpreting the Z-scan results has been proposed. In this procedure, by separately performing open- and closed-aperture Z-scan experiments and using the represented relations for the far-field transmittances, one can measure the nonlinear absorption coefficient and nonlinear index of refraction as well as the order of nonlocality. Theoretically, it is shown that when the absorptive nonlinearity is present in addition to the refractive nonlinearity, the sample nonlocal response can noticeably suppress the peak and enhance the valley of the Z-scan closed-aperture transmittance curves, which is due to the nonlocal action's ability to change the beam transverse dimensions.

Epitaxial Growth and Electronic Structure of Half Heuslers Co1-xNixTiSb (001), Ni1-xCoxTiSn, and PtLuSb

DTIC Science & Technology

2016-01-09

studied in detail using scanning tunneling microscopy and angle resolved photoemission. For the doping levels achieved in cobalt titanium antimony, the...angle resolved photoemission. For the doping levels achieved in cobalt titanium antimony, the electron mobility at room temperature was comparable...scanning tunneling microscopy and angle resolved photoemission. For the doping levels achieved in cobalt titanium antimony, the electron mobility at room

Assessing Mobile Health Capacity and Task Shifting Strategies to Improve Hypertension Among Ghanaian Stroke Survivors.

PubMed

Nichols, Michelle; Sarfo, Fred Stephen; Singh, Arti; Qanungo, Suparna; Treiber, Frank; Ovbiagele, Bruce; Saulson, Raelle; Patel, Sachin; Jenkins, Carolyn

2017-12-01

There has been a tremendous surge in stroke prevalence in sub-Saharan Africa. Hypertension (HTN), the most potent, modifiable risk factor for stroke, is a particular challenge in sub-Saharan Africa. Culturally sensitive, efficacious HTN control programs that are timely and sustainable are needed, especially among stroke survivors. Mobile health (mHealth) technology and task-shifting offer promising approaches to address this need. Using a concurrent triangulation design, we collected data from stroke survivors, caregivers, community leaders, clinicians and hospital personnel to explore the barriers, facilitators and perceptions toward mHealth related to HTN management among poststroke survivors in Ghana. Exploration included perceptions of a nurse-led navigational model to facilitate care delivery and willingness of stroke survivors and caregivers to use mHealth technology. Two hundred stroke survivors completed study surveys while focus groups (n = 4) were conducted with stroke survivors, caregivers and community leaders (n = 28). Key informant interviews were completed with clinicians and hospital personnel (n = 10). A total of 93% of survey respondents had HTN (60% uncontrolled). Findings support mHealth strategies for poststroke care delivery and HTN management and for task-shifting through a nurse-led model. Of survey and focus group participants, 76% and 78.6%, respectively, have access to mobile phones and 90% express comfort in using mobile phones and conveyed assurance that task-shifting through a nurse-led model could facilitate management of HTN. Findings also identified barriers to care delivery and medication adherence across all levels of the social ecological model. Participants strongly supported enhanced care delivery through mobile health and were receptive toward a nurse-led navigational model. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

Design and verification of the miniature optical system for small object surface profile fast scanning

NASA Astrophysics Data System (ADS)

Chi, Sheng; Lee, Shu-Sheng; Huang, Jen, Jen-Yu; Lai, Ti-Yu; Jan, Chia-Ming; Hu, Po-Chi

2016-04-01

As the progress of optical technologies, different commercial 3D surface contour scanners are on the market nowadays. Most of them are used for reconstructing the surface profile of mold or mechanical objects which are larger than 50 mm×50 mm× 50 mm, and the scanning system size is about 300 mm×300 mm×100 mm. There are seldom optical systems commercialized for surface profile fast scanning for small object size less than 10 mm×10 mm×10 mm. Therefore, a miniature optical system has been designed and developed in this research work for this purpose. Since the most used scanning method of such system is line scan technology, we have developed pseudo-phase shifting digital projection technology by adopting projecting fringes and phase reconstruction method. A projector was used to project a digital fringe patterns on the object, and the fringes intensity images of the reference plane and of the sample object were recorded by a CMOS camera. The phase difference between the plane and object can be calculated from the fringes images, and the surface profile of the object was reconstructed by using the phase differences. The traditional phase shifting method was accomplished by using PZT actuator or precisely controlled motor to adjust the light source or grating and this is one of the limitations for high speed scanning. Compared with the traditional optical setup, we utilized a micro projector to project the digital fringe patterns on the sample. This diminished the phase shifting processing time and the controlled phase differences between the shifted phases become more precise. Besides, the optical path design based on a portable device scanning system was used to minimize the size and reduce the number of the system components. A screwdriver section about 7mm×5mm×5mm has been scanned and its surface profile was successfully restored. The experimental results showed that the measurement area of our system can be smaller than 10mm×10mm, the precision reached to +/-10μm, and the scanning time for each surface of an object was less than 15 seconds. This has proved that our system own the potential to be a fast scanning scanner for small object surface profile scanning.

3D Digital Smile Design With a Mobile Phone and Intraoral Optical Scanner.

PubMed

Daher, René; Ardu, Stefano; Vjero, Osela; Krejci, Ivo

2018-06-01

Extraoral facial scanning using a mobile phone has emerged as a viable, cost-effective option for certain applications not requiring high precision, such as patient education and 3-dimensional (3D) digital smile design. This technological development is particularly promising for general practitioners (GPs) who may not be able to invest in expensive,complex digital impressioning devices. This article describes and illustrates a relatively simple and accessible workflow that avails digital 3D facial scanning benefits to GPs.

What Have We Learnt about Mobile LifeLong Learning (mLLL)?

ERIC Educational Resources Information Center

Seta, Luciano; Kukulska-Hulme, Agnes; Arrigo, Marco

2014-01-01

Mobile technologies are becoming ubiquitous in education, yet the wider implications of this phenomenon are not well understood. The paper discusses how mobile lifelong learning (mLLL) may be defined, and the challenges of forging a suitable definition in an ever-shifting technological and socio-economic landscape. mLLL appears as a ubiquitous…

Mobile Devices and Mobile Learning: Shifting the Mindset of Teachers and Learners

ERIC Educational Resources Information Center

Smith, Philippa K.; Grant, Lynn; Conway, Clare; Narayan, Vickel

2016-01-01

Incorporating new media technologies that enable mobile learning to be part of educational practice poses challenges to those used to teaching in a traditional classroom environment. In this article three lecturers and a learning advisor from a New Zealand university reflect on their experiences in the progressive redesign of a Bachelor of Arts…

Access-in-turn test architecture for low-power test application

NASA Astrophysics Data System (ADS)

Wang, Weizheng; Wang, JinCheng; Wang, Zengyun; Xiang, Lingyun

2017-03-01

This paper presents a novel access-in-turn test architecture (AIT-TA) for testing of very large scale integrated (VLSI) designs. In the proposed scheme, each scan cell in a chain receives test data from shift-in line in turn while pushing its test response to the shift-out line. It solves the power problem of conventional scan architecture to a great extent and suppresses significantly the switching activity during shift and capture operation with acceptable hardware overhead. Thus, it can help to implement the test at much higher operation frequencies resulting shorter test application time. The proposed test approach enhances the architecture of conventional scan flip-flops and backward compatible with existing test pattern generation and simulation techniques. Experimental results obtained for some larger ISCAS'89 and ITC'99 benchmark circuits illustrate effectiveness of the proposed low-power test application scheme.

Measuring and imaging diffusion with multiple scan speed image correlation spectroscopy.

PubMed

Gröner, Nadine; Capoulade, Jérémie; Cremer, Christoph; Wachsmuth, Malte

2010-09-27

The intracellular mobility of biomolecules is determined by transport and diffusion as well as molecular interactions and is crucial for many processes in living cells. Methods of fluorescence microscopy like confocal laser scanning microscopy (CLSM) can be used to characterize the intracellular distribution of fluorescently labeled biomolecules. Fluorescence correlation spectroscopy (FCS) is used to describe diffusion, transport and photo-physical processes quantitatively. As an alternative to FCS, spatially resolved measurements of mobilities can be implemented using a CLSM by utilizing the spatio-temporal information inscribed into the image by the scan process, referred to as raster image correlation spectroscopy (RICS). Here we present and discuss an extended approach, multiple scan speed image correlation spectroscopy (msICS), which benefits from the advantages of RICS, i.e. the use of widely available instrumentation and the extraction of spatially resolved mobility information, without the need of a priori knowledge of diffusion properties. In addition, msICS covers a broad dynamic range, generates correlation data comparable to FCS measurements, and allows to derive two-dimensional maps of diffusion coefficients. We show the applicability of msICS to fluorophores in solution and to free EGFP in living cells.

Investigation of AlGaN/GaN high electron mobility transistor structures on 200-mm silicon (111) substrates employing different buffer layer configurations.

PubMed

Lee, H-P; Perozek, J; Rosario, L D; Bayram, C

2016-11-21

AlGaN/GaN high electron mobility transistor (HEMT) structures are grown on 200-mm diameter Si(111) substrates by using three different buffer layer configurations: (a) Thick-GaN/3 × {Al x Ga 1-x N}/AlN, (b) Thin-GaN/3 × {Al x Ga 1-x N}/AlN, and (c) Thin-GaN/AlN, so as to have crack-free and low-bow (<50 μm) wafer. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, high resolution-cross section transmission electron microscopy, optical microscopy, atomic-force microscopy, cathodoluminescence, Raman spectroscopy, X-ray diffraction (ω/2θ scan and symmetric/asymmetric ω scan (rocking curve scan), reciprocal space mapping) and Hall effect measurements are employed to study the structural, optical, and electrical properties of these AlGaN/GaN HEMT structures. The effects of buffer layer stacks (i.e. thickness and content) on defectivity, stress, and two-dimensional electron gas (2DEG) mobility and 2DEG concentration are reported. It is shown that 2DEG characteristics are heavily affected by the employed buffer layers between AlGaN/GaN HEMT structures and Si(111) substrates. Particularly, we report that in-plane stress in the GaN layer affects the 2DEG mobility and 2DEG carrier concentration significantly. Buffer layer engineering is shown to be essential for achieving high 2DEG mobility (>1800 cm 2 /V∙s) and 2DEG carrier concentration (>1.0 × 10 13  cm -2 ) on Si(111) substrates.

Investigation of AlGaN/GaN high electron mobility transistor structures on 200-mm silicon (111) substrates employing different buffer layer configurations

PubMed Central

Lee, H.-P.; Perozek, J.; Rosario, L. D.; Bayram, C.

2016-01-01

AlGaN/GaN high electron mobility transistor (HEMT) structures are grown on 200-mm diameter Si(111) substrates by using three different buffer layer configurations: (a) Thick-GaN/3 × {AlxGa1−xN}/AlN, (b) Thin-GaN/3 × {AlxGa1−xN}/AlN, and (c) Thin-GaN/AlN, so as to have crack-free and low-bow (<50 μm) wafer. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, high resolution-cross section transmission electron microscopy, optical microscopy, atomic-force microscopy, cathodoluminescence, Raman spectroscopy, X-ray diffraction (ω/2θ scan and symmetric/asymmetric ω scan (rocking curve scan), reciprocal space mapping) and Hall effect measurements are employed to study the structural, optical, and electrical properties of these AlGaN/GaN HEMT structures. The effects of buffer layer stacks (i.e. thickness and content) on defectivity, stress, and two-dimensional electron gas (2DEG) mobility and 2DEG concentration are reported. It is shown that 2DEG characteristics are heavily affected by the employed buffer layers between AlGaN/GaN HEMT structures and Si(111) substrates. Particularly, we report that in-plane stress in the GaN layer affects the 2DEG mobility and 2DEG carrier concentration significantly. Buffer layer engineering is shown to be essential for achieving high 2DEG mobility (>1800 cm2/V∙s) and 2DEG carrier concentration (>1.0 × 1013 cm−2) on Si(111) substrates. PMID:27869222

Benchmarking the Performance of Mobile Laser Scanning Systems Using a Permanent Test Field

PubMed Central

Kaartinen, Harri; Hyyppä, Juha; Kukko, Antero; Jaakkola, Anttoni; Hyyppä, Hannu

2012-01-01

The performance of various mobile laser scanning systems was tested on an established urban test field. The test was connected to the European Spatial Data Research (EuroSDR) project “Mobile Mapping—Road Environment Mapping Using Mobile Laser Scanning”. Several commercial and research systems collected laser point cloud data on the same test field. The system comparisons focused on planimetric and elevation errors using a filtered digital elevation model, poles, and building corners as the reference objects. The results revealed the high quality of the point clouds generated by all of the tested systems under good GNSS conditions. With all professional systems properly calibrated, the elevation accuracy was better than 3.5 cm up to a range of 35 m. The best system achieved a planimetric accuracy of 2.5 cm over a range of 45 m. The planimetric errors increased as a function of range, but moderately so if the system was properly calibrated. The main focus on mobile laser scanning development in the near future should be on the improvement of the trajectory solution, especially under non-ideal conditions, using both improvements in hardware and software. Test fields are relatively easy to implement in built environments and they are feasible for verifying and comparing the performance of different systems and also for improving system calibration to achieve optimum quality.

Continuous scanning of the mobility and size distribution of charged clusters and nanometer particles in atmospheric air and the Balanced Scanning Mobility Analyzer BSMA

NASA Astrophysics Data System (ADS)

Tammet, H.

2006-12-01

Measuring of charged nanometer particles in atmospheric air is a routine task in research on atmospheric electricity, where these particles are called the atmospheric ions. An aspiration condenser is the most popular instrument for measuring atmospheric ions. Continuous scanning of a mobility distribution is possible when the aspiration condenser is connected as an arm of a balanced bridge. Transfer function of an aspiration condenser is calculated according to the measurements of geometric dimensions, air flow rate, driving voltage, and electric current. The most complicated phase of the calibration is the estimation of the inlet loss of ions due to the Brownian deposition. The available models of ion deposition on the protective inlet screen and the inlet control electrofilter have the uncertainty of about 20%. To keep the uncertainty of measurements low the adsorption should not exceed a few tens of percent. The online conversion of the mobility distribution to the size distribution and a correct reduction of inlet losses are possible when air temperature and pressure are measured simultaneously with the mobility distribution. Two instruments called the Balanced Scanning Mobility Analyzers (BSMA) were manufactured and tested in routine atmospheric measurements. The concentration of atmospheric ions of the size of about a few nanometers is very low and a high air flow rate is required to collect enough of ion current. The air flow of 52 l/s exceeds the air flow in usual aerosol instruments by 2-3 orders of magnitude. The high flow rate reduces the time of ion passage to 60 ms and the heating of air in an analyzer to 0.2 K, which suppresses a possible transformation of ions inside the instrument. The mobility range of the BSMA of 0.032-3.2 cm 2 V - 1 s - 1 is logarithmically uniformly divided into 16 fractions. The size distribution is presented by 12 fractions in the diameter range of 0.4-7.5 nm. The measurement noise of a fraction concentration is typically about 5 cm - 3 and the time resolution is about 10 min when measuring simultaneously both positive and negative ions in atmospheric air.

To Move Forward, We Must Be Mobile: Practical Uses of Mobile Technology in Literacy Education Courses

ERIC Educational Resources Information Center

Husbye, Nicholas E.; Elsener, Anne A.

2013-01-01

Technology continues to shift the definition of what it means to be literate. As literacy educators in teacher preparation programs, we must consider how emerging and mobile technology may be used within coursework to not only create multiple ways to conceptualize teaching 21st century literacy, but also as a professional imperative. This article…

Performance Comparison of Field Portable Instruments to the Scanning Mobility Particle Sizer Using Monodispersed and Polydispersed Sodium Chloride Aerosols.

PubMed

Vo, Evanly; Horvatin, Matthew; Zhuang, Ziqing

2018-05-21

This study compared the performance of the following field portable aerosol instrument sets to performance of the reference Scanning Mobility Particle Sizer (SMPS): the handheld CPC-3007, the portable aerosol mobility spectrometer (PAMS), the NanoScan scanning mobility particle sizer (NanoScan SMPS) combined with an optical particle sizer (OPS). Tests were conducted with monodispersed and polydispersed aerosols. Monodispersed aerosols were controlled at the approximate concentration of 1 × 105 particles cm-3 and four monodispersed particle sizes of 30, 60, 100, and 300 nm were selected and classified for the monodispersed aerosol test, while three different steady-state concentration levels (low, medium, and high: ~8 × 103, 5 × 104, and 1 × 105 particles cm-3, respectively) were selected for the polydispersed aerosol test. For all four monodispersed aerosol sizes, particle concentrations measured with the NanoScan SMPS were within 13% of those measured with the reference SMPS. Particle concentrations measured with the PAMS were within 25% of those measured with the reference SMPS. Concentrations measured with the handheld condensation particle counter were within 30% of those measured with the reference SMPS. For the polydispersed aerosols, the particle sizes and concentrations measured with the NanoScan-OPS compared most favorably with those measured with the reference SMPS for three different concentration levels of low, medium, and high (concentration deviations ≤10% for all three concentration levels; deviations of particle size ≤4%). Although the particle-size comparability between the PAMS and the reference SMPS was quite reasonable with the deviations within 10%, the polydispersed particle concentrations measured with the PAMS were within 36% of those measured with the reference SMPS. The results of this evaluation will be useful for selecting a suitable portable device for our next workplace study phase of respiratory protection assessment. This study also provided the advantages and limitations of each individual portable instrument and therefore results from this study can be used by industrial hygienists and safety professionals, with appropriate caution, when selecting a suitable portable instrument for aerosol particle measurement in nanotechnology workplaces.

An intelligent detection method for high-field asymmetric waveform ion mobility spectrometry.

PubMed

Li, Yue; Yu, Jianwen; Ruan, Zhiming; Chen, Chilai; Chen, Ran; Wang, Han; Liu, Youjiang; Wang, Xiaozhi; Li, Shan

2018-04-01

In conventional high-field asymmetric waveform ion mobility spectrometry signal acquisition, multi-cycle detection is time consuming and limits somewhat the technique's scope for rapid field detection. In this study, a novel intelligent detection approach has been developed in which a threshold was set on the relative error of α parameters, which can eliminate unnecessary time spent on detection. In this method, two full-spectrum scans were made in advance to obtain the estimated compensation voltage at different dispersion voltages, resulting in a narrowing down of the whole scan area to just the peak area(s) of interest. This intelligent detection method can reduce the detection time to 5-10% of that of the original full-spectrum scan in a single cycle.

[The Effects of Mobile Social Networking Service-Based Cognitive Behavior Therapy on Insomnia in Nurses].

PubMed

Kim, Ji Eun; Kim, Suk Sun

2017-08-01

This study aimed to examine the effects of cognitive behavior therapy for insomnia (CBT-I) based on the mobile social networking service (SNS) on dysfunctional beliefs and attitudes about sleep, sleep quality, daytime sleepiness, depression, and quality of life among rotating-shift nurses in a hospital in Korea. A nonequivalent control group pre-post test design was used. The participants included 55 nurses with rotating three-shift work (25 in the experimental group and 30 in the control group). For the experimental group, CBT-I using mobile SNS was provided once a week for 60 minutes over six weeks. Data were analyzed using descriptive statistics, χ²-test, independent samples t-test, and Mann-whitney U test with the SPSS 21.0 program. In the homogeneity test of the general characteristics and study variables, there were no significant differences between the two groups. Nurses in the experimental group had significantly lower scores on dysfunctional beliefs and attitudes regarding sleep and sleepiness than nurses in the control group. Nurses in the experimental group had significantly higher scores on sleep quality and quality of life than nurses in the control group. These findings indicate that using the mobile SNS-based CBT-I is feasible and has significant and positive treatment-related effects on rotating-shift nurses' irrational thoughts and beliefs in association with sleep, sleep quality, daytime sleepiness, and quality of life. These contribute to expanding our knowledge of rotating-shift nurses' sleep issues and their preferences for intervention. © 2017 Korean Society of Nursing Science

Quantifying attention shifts in augmented reality image-guided neurosurgery

PubMed Central

Drouin, Simon; Collins, D. Louis; Popa, Tiberiu; Kersten-Oertel, Marta

2017-01-01

Image-guided surgery (IGS) has allowed for more minimally invasive procedures, leading to better patient outcomes, reduced risk of infection, less pain, shorter hospital stays and faster recoveries. One drawback that has emerged with IGS is that the surgeon must shift their attention from the patient to the monitor for guidance. Yet both cognitive and motor tasks are negatively affected with attention shifts. Augmented reality (AR), which merges the realworld surgical scene with preoperative virtual patient images and plans, has been proposed as a solution to this drawback. In this work, we studied the impact of two different types of AR IGS set-ups (mobile AR and desktop AR) and traditional navigation on attention shifts for the specific task of craniotomy planning. We found a significant difference in terms of the time taken to perform the task and attention shifts between traditional navigation, but no significant difference between the different AR set-ups. With mobile AR, however, users felt that the system was easier to use and that their performance was better. These results suggest that regardless of where the AR visualisation is shown to the surgeon, AR may reduce attention shifts, leading to more streamlined and focused procedures. PMID:29184663

Quantifying attention shifts in augmented reality image-guided neurosurgery.

PubMed

Léger, Étienne; Drouin, Simon; Collins, D Louis; Popa, Tiberiu; Kersten-Oertel, Marta

2017-10-01

Image-guided surgery (IGS) has allowed for more minimally invasive procedures, leading to better patient outcomes, reduced risk of infection, less pain, shorter hospital stays and faster recoveries. One drawback that has emerged with IGS is that the surgeon must shift their attention from the patient to the monitor for guidance. Yet both cognitive and motor tasks are negatively affected with attention shifts. Augmented reality (AR), which merges the realworld surgical scene with preoperative virtual patient images and plans, has been proposed as a solution to this drawback. In this work, we studied the impact of two different types of AR IGS set-ups (mobile AR and desktop AR) and traditional navigation on attention shifts for the specific task of craniotomy planning. We found a significant difference in terms of the time taken to perform the task and attention shifts between traditional navigation, but no significant difference between the different AR set-ups. With mobile AR, however, users felt that the system was easier to use and that their performance was better. These results suggest that regardless of where the AR visualisation is shown to the surgeon, AR may reduce attention shifts, leading to more streamlined and focused procedures.

Domestic scan tour report : land use and transportation coordination : lessons learned from domestic scan tour

DOT National Transportation Integrated Search

2003-03-01

Designing transportation systems that enhance mobility, economic opportunity, and community livability is a major challenge for many communities across the country. In the United States, political leaders, planning professionals, and private citizens...

Scan Line Based Road Marking Extraction from Mobile LiDAR Point Clouds.

PubMed

Yan, Li; Liu, Hua; Tan, Junxiang; Li, Zan; Xie, Hong; Chen, Changjun

2016-06-17

Mobile Mapping Technology (MMT) is one of the most important 3D spatial data acquisition technologies. The state-of-the-art mobile mapping systems, equipped with laser scanners and named Mobile LiDAR Scanning (MLS) systems, have been widely used in a variety of areas, especially in road mapping and road inventory. With the commercialization of Advanced Driving Assistance Systems (ADASs) and self-driving technology, there will be a great demand for lane-level detailed 3D maps, and MLS is the most promising technology to generate such lane-level detailed 3D maps. Road markings and road edges are necessary information in creating such lane-level detailed 3D maps. This paper proposes a scan line based method to extract road markings from mobile LiDAR point clouds in three steps: (1) preprocessing; (2) road points extraction; (3) road markings extraction and refinement. In preprocessing step, the isolated LiDAR points in the air are removed from the LiDAR point clouds and the point clouds are organized into scan lines. In the road points extraction step, seed road points are first extracted by Height Difference (HD) between trajectory data and road surface, then full road points are extracted from the point clouds by moving least squares line fitting. In the road markings extraction and refinement step, the intensity values of road points in a scan line are first smoothed by a dynamic window median filter to suppress intensity noises, then road markings are extracted by Edge Detection and Edge Constraint (EDEC) method, and the Fake Road Marking Points (FRMPs) are eliminated from the detected road markings by segment and dimensionality feature-based refinement. The performance of the proposed method is evaluated by three data samples and the experiment results indicate that road points are well extracted from MLS data and road markings are well extracted from road points by the applied method. A quantitative study shows that the proposed method achieves an average completeness, correctness, and F-measure of 0.96, 0.93, and 0.94, respectively. The time complexity analysis shows that the scan line based road markings extraction method proposed in this paper provides a promising alternative for offline road markings extraction from MLS data.

Scan Line Based Road Marking Extraction from Mobile LiDAR Point Clouds†

PubMed Central

Yan, Li; Liu, Hua; Tan, Junxiang; Li, Zan; Xie, Hong; Chen, Changjun

2016-01-01

Mobile Mapping Technology (MMT) is one of the most important 3D spatial data acquisition technologies. The state-of-the-art mobile mapping systems, equipped with laser scanners and named Mobile LiDAR Scanning (MLS) systems, have been widely used in a variety of areas, especially in road mapping and road inventory. With the commercialization of Advanced Driving Assistance Systems (ADASs) and self-driving technology, there will be a great demand for lane-level detailed 3D maps, and MLS is the most promising technology to generate such lane-level detailed 3D maps. Road markings and road edges are necessary information in creating such lane-level detailed 3D maps. This paper proposes a scan line based method to extract road markings from mobile LiDAR point clouds in three steps: (1) preprocessing; (2) road points extraction; (3) road markings extraction and refinement. In preprocessing step, the isolated LiDAR points in the air are removed from the LiDAR point clouds and the point clouds are organized into scan lines. In the road points extraction step, seed road points are first extracted by Height Difference (HD) between trajectory data and road surface, then full road points are extracted from the point clouds by moving least squares line fitting. In the road markings extraction and refinement step, the intensity values of road points in a scan line are first smoothed by a dynamic window median filter to suppress intensity noises, then road markings are extracted by Edge Detection and Edge Constraint (EDEC) method, and the Fake Road Marking Points (FRMPs) are eliminated from the detected road markings by segment and dimensionality feature-based refinement. The performance of the proposed method is evaluated by three data samples and the experiment results indicate that road points are well extracted from MLS data and road markings are well extracted from road points by the applied method. A quantitative study shows that the proposed method achieves an average completeness, correctness, and F-measure of 0.96, 0.93, and 0.94, respectively. The time complexity analysis shows that the scan line based road markings extraction method proposed in this paper provides a promising alternative for offline road markings extraction from MLS data. PMID:27322279

Mobile Communication and Civil Society: Linking Patterns and Places of Use to Engagement with Others in Public

ERIC Educational Resources Information Center

Campbell, Scott W.; Kwak, Nojin

2011-01-01

This study examined whether and how mobile communication influences the extent to which one engages with new people in public settings. Contrary to our expectation, general use of the technology in public did not detract from conversing with strangers. Shifting focus from "where" one uses the mobile phone to "how" it is used, we found that uses…

A Greedy Scanning Data Collection Strategy for Large-Scale Wireless Sensor Networks with a Mobile Sink.

PubMed

Zhu, Chuan; Zhang, Sai; Han, Guangjie; Jiang, Jinfang; Rodrigues, Joel J P C

2016-09-06

Mobile sink is widely used for data collection in wireless sensor networks. It can avoid 'hot spot' problems but energy consumption caused by multihop transmission is still inefficient in real-time application scenarios. In this paper, a greedy scanning data collection strategy (GSDCS) is proposed, and we focus on how to reduce routing energy consumption by shortening total length of routing paths. We propose that the mobile sink adjusts its trajectory dynamically according to the changes of network, instead of predetermined trajectory or random walk. Next, the mobile sink determines which area has more source nodes, then it moves toward this area. The benefit of GSDCS is that most source nodes are no longer needed to upload sensory data for long distances. Especially in event-driven application scenarios, when event area changes, the mobile sink could arrive at the new event area where most source nodes are located currently. Hence energy can be saved. Analytical and simulation results show that compared with existing work, our GSDCS has a better performance in specific application scenarios.

A Greedy Scanning Data Collection Strategy for Large-Scale Wireless Sensor Networks with a Mobile Sink

PubMed Central

Zhu, Chuan; Zhang, Sai; Han, Guangjie; Jiang, Jinfang; Rodrigues, Joel J. P. C.

2016-01-01

Mobile sink is widely used for data collection in wireless sensor networks. It can avoid ‘hot spot’ problems but energy consumption caused by multihop transmission is still inefficient in real-time application scenarios. In this paper, a greedy scanning data collection strategy (GSDCS) is proposed, and we focus on how to reduce routing energy consumption by shortening total length of routing paths. We propose that the mobile sink adjusts its trajectory dynamically according to the changes of network, instead of predetermined trajectory or random walk. Next, the mobile sink determines which area has more source nodes, then it moves toward this area. The benefit of GSDCS is that most source nodes are no longer needed to upload sensory data for long distances. Especially in event-driven application scenarios, when event area changes, the mobile sink could arrive at the new event area where most source nodes are located currently. Hence energy can be saved. Analytical and simulation results show that compared with existing work, our GSDCS has a better performance in specific application scenarios. PMID:27608022

A walk by the river: three-dimensional reconstruction of surface sedimentology and topography using wearable laser scanning

NASA Astrophysics Data System (ADS)

Williams, R.; Lamy, M. L.; Stott, E.; Maniatis, G.

2017-12-01

In the last two decades, quantification of fluvial topography has been transformed by a number of geomatics technologies that have enabled the acquisition of data with unprecedented spatial resolution. Hyperscale surveys with spatial extents of <1 km2 have been widely demonstrated, by means of Terrestrial Laser Scanning (TLS) and Structure-from-Motion (SfM) photogrammetry. Recent advances in the development and integration of GNSS, IMU, lightweight laser scanning and SLAM technologies are now resulting in the emergence of wearable, mobile laser scanning systems that have the potential to increase data acquisition and processing rates by 1-2 orders of magnitude compared to TLS/SfM, and thus challenge the recent dominance of these two geomatics technologies. In this study we describe the methods and results of a comparison between a wearable laser scanning survey, using a Leica Pegasus Backpack, and a multi-station static TLS survey, using a Riegl VZ-1000 scanner. The evaluation is undertaken on a 600 m long reach of the braided River Feshie, Scotland, using data acquired in June 2017. Comparison between the DEMs produced from static and mobile laser scanning, across non-vegetated areas, revealed a Mean Error (ME) of -0.002 m and a Standard Deviation Error (SDE) of 0.109 m. Comparison to 100 independent check point resulted in a similar ME and SDE for static (ME = 0.061m; SDE = 0.030 m) and mobile (ME = 0.044 m; SDE = 0.029 m) laser scanning. Empirical relationships between sub-metre topographic variability and median sediment grain size (10-100 mm), across 14 grid-by-number samples, were similar and demonstrate that surface roughness from wearable laser scanning can be used to derive reach-scale maps of median grain size. These results demonstrate that wearable laser scanning generates hyperscale topographic models that are comparable in quality to more time-consuming multi-station TLS setups. Wearable laser scanning is likely to be commonly adopted for fluvial topographic surveys and will become established as a versatile survey technology.

Doppler color imaging. Principles and instrumentation.

PubMed

Kremkau, F W

1992-01-01

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

Robustness of the Voluntary Breath-Hold Approach for the Treatment of Peripheral Lung Tumors Using Hypofractionated Pencil Beam Scanning Proton Therapy

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

Dueck, Jenny, E-mail: jenny.dueck@psi.ch; Center for Proton Therapy, Paul Scherrer Institut, Villigen PSI; Niels Bohr Institute, University of Copenhagen, Copenhagen

Purpose: The safe clinical implementation of pencil beam scanning (PBS) proton therapy for lung tumors is complicated by the delivery uncertainties caused by breathing motion. The purpose of this feasibility study was to investigate whether a voluntary breath-hold technique could limit the delivery uncertainties resulting from interfractional motion. Methods and Materials: Data from 15 patients with peripheral lung tumors previously treated with stereotactic radiation therapy were included in this study. The patients had 1 computed tomographic (CT) scan in voluntary breath-hold acquired before treatment and 3 scans during the treatment course. PBS proton treatment plans with 2 fields (2F) andmore » 3 fields (3F), respectively, were calculated based on the planning CT scan and subsequently recalculated on the 3 repeated CT scans. Recalculated plans were considered robust if the V{sub 95%} (volume receiving ≥95% of the prescribed dose) of the gross target volume (GTV) was within 5% of what was expected from the planning CT data throughout the simulated treatment. Results: A total of 14/15 simulated treatments for both 2F and 3F met the robustness criteria. Reduced V{sub 95%} was associated with baseline shifts (2F, P=.056; 3F, P=.008) and tumor size (2F, P=.025; 3F, P=.025). Smaller tumors with large baseline shifts were also at risk for reduced V{sub 95%} (interaction term baseline/size: 2F, P=.005; 3F, P=.002). Conclusions: The breath-hold approach is a realistic clinical option for treating lung tumors with PBS proton therapy. Potential risk factors for reduced V{sub 95%} are small targets in combination with large baseline shifts. On the basis of these results, the baseline shift of the tumor should be monitored (eg, through image guided therapy), and appropriate measures should be taken accordingly. The intrafractional motion needs to be investigated to confirm that the breath-hold approach is robust.« less

Changes in brain glioma incidence and laterality correlates with use of mobile phones--a nationwide population based study in Israel.

PubMed

Barchana, Micha; Margaliot, Menahem; Liphshitz, Irena

2012-01-01

Mobile phones are in extensive use worldwide and concerns regarding their role in tumor formation were raised. Over the years multiple studies were published in order to investigate this issue using several approaches. The current study looks at secular trends of brain gliomas (low and high grade) incidence and changes in tumor's laterality over 30 years in a population extensively using this technology with a possible correlation to the spread of use of mobile phones. All brain gliomas that were diagnosed from 1980-2009 were included and subdivided into two groups--low and high grade. Secular and periodic time trend analyses of incidence rates and changes in laterality were performed. Preferred side of head using mobile phones was assessed with a questionnaire in a sample of adult individuals. A decrease in incidence of low grade giomas (LGG) that correlated with introduction of mobile technology was found from 2.57, 2.34 and 2.79 for every 100,000 in the period 1980 to the end of 1994 to 1.72, 1.82 and 1.57, respectively, over the last three 5-years periods (1995-2009). High-grade glioma incidences increased significantly from 1980-2009 but in the period after mobile phones were introduced (1994-2009) a lower, non significant, rate of increase was observed in males and a lower one (significant) in females. A shift towards left sided tumor location for all adult gliomas combined and separately for LGG and HGG was noted from 1995 onward. The shift was more marked for those who were diagnosed in ages 20-49 (p=0.03). We found a statistically significant decrease in LGG's over 30-years period that correlates with introducing of mobile phones technology and a shift in laterality towards left-sided tumors, the latter occurred in both low and high-grade gliomas.

Investigating the Use of Text Messages in Mobile Learning

ERIC Educational Resources Information Center

Geng, Gretchen

2013-01-01

Nowadays, teaching and learning have been shifted from traditional classrooms to technology-supported learning environment. By offering a convenient, efficient and financially affordable information technology learning environment, mobile learning is a topic that is of considerable interest for education audiences owing to the pervasive nature of…

Differential detection of Gaussian MSK in a mobile radio environment

NASA Technical Reports Server (NTRS)

Simon, M. K.; Wang, C. C.

1984-01-01

Minimum shift keying with Gaussian shaped transmit pulses is a strong candidate for a modulation technique that satisfies the stringent out-of-band radiated power requirements of the mobil radio application. Numerous studies and field experiments have been conducted by the Japanese on urban and suburban mobile radio channels with systems employing Gaussian minimum-shift keying (GMSK) transmission and differentially coherent reception. A comprehensive analytical treatment is presented of the performance of such systems emphasizing the important trade-offs among the various system design parameters such as transmit and receiver filter bandwidths and detection threshold level. It is shown that two-bit differential detection of GMSK is capable of offering far superior performance to the more conventional one-bit detection method both in the presence of an additive Gaussian noise background and Rician fading.

Differential detection of Gaussian MSK in a mobile radio environment

NASA Astrophysics Data System (ADS)

Simon, M. K.; Wang, C. C.

1984-11-01

Minimum shift keying with Gaussian shaped transmit pulses is a strong candidate for a modulation technique that satisfies the stringent out-of-band radiated power requirements of the mobil radio application. Numerous studies and field experiments have been conducted by the Japanese on urban and suburban mobile radio channels with systems employing Gaussian minimum-shift keying (GMSK) transmission and differentially coherent reception. A comprehensive analytical treatment is presented of the performance of such systems emphasizing the important trade-offs among the various system design parameters such as transmit and receiver filter bandwidths and detection threshold level. It is shown that two-bit differential detection of GMSK is capable of offering far superior performance to the more conventional one-bit detection method both in the presence of an additive Gaussian noise background and Rician fading.

Stop-and-Go Mode: Sensor Manipulation as Essential as Sensor Development in Terrestrial Laser Scanning

PubMed Central

Lin, Yi; Hyyppä, Juha; Kukko, Antero

2013-01-01

This study was dedicated to illustrating the significance of sensor manipulation in the case of terrestrial laser scanning, which is a field now in quick development. In fact, this quickness was mainly rooted in the emergence of new sensors with better performance, while the implications of sensor manipulation have not been fully recognized by the whole community. For this technical gap, the stop-and-go mapping mode can be reckoned as one of the potential solution plans. Stop-and-go was first proposed to handle the low efficiency of traditional static terrestrial laser scanning, and then, it was re-emphasized to improve the stability of sample collections for the state-of-the-art technology of mobile laser scanning. This work reviewed the previous efforts of trying the stop-and-go mode for improving the performance of static and mobile terrestrial laser scanning and generalized their principles respectively. This work also analyzed its advantages compared to the fully-static and fully-kinematic terrestrial laser scanning, and suggested the plans with more automatic measures for raising the efficacy of terrestrial laser scanning. Overall, this literature review indicated that the stop-and-go mapping mode as a case with generic sense can verify the presumption of sensor manipulation as essential as sensor development. PMID:23799493

Rapid and Simple Detection of Hot Spot Point Mutations of Epidermal Growth Factor Receptor, BRAF, and NRAS in Cancers Using the Loop-Hybrid Mobility Shift Assay

PubMed Central

Matsukuma, Shoichi; Yoshihara, Mitsuyo; Kasai, Fumio; Kato, Akinori; Yoshida, Akira; Akaike, Makoto; Kobayashi, Osamu; Nakayama, Haruhiko; Sakuma, Yuji; Yoshida, Tsutomu; Kameda, Yoichi; Tsuchiya, Eiju; Miyagi, Yohei

2006-01-01

A simple and rapid method to detect the epidermal growth factor receptor hot spot mutation L858R in lung adenocarcinoma was developed based on principles similar to the universal heteroduplex generator technology. A single-stranded oligonucleotide with an internal deletion was used to generate heteroduplexes (loop-hybrids) bearing a loop in the complementary strand derived from the polymerase chain reaction product of the normal or mutant allele. By placing deletion in the oligonucleotide adjacent to the mutational site, difference in electrophoretic mobility between loop-hybrids with normal and mutated DNA was distinguishable in a native polyacrylamide gel. The method was also modified to detect in-frame deletion mutations of epidermal growth factor receptor in lung adenocarcinomas. In addition, the method was adapted to detect hot spot mutations in the B-type Raf kinase (BRAF) at V600 and in a Ras-oncogene (NRAS) at Q61, the mutations commonly found in thyroid carcinomas. Our mutation detection system, designated the loop-hybrid mobility shift assay was sensitive enough to detect mutant DNA comprising 7.5% of the total DNA. As a simple and straightforward mutation detection technique, loop-hybrid mobility shift assay may be useful for the molecular diagnosis of certain types of clinical cancers. Other applications are also discussed. PMID:16931592

Continuous wave dye-laser technique for simultaneous, spatially resolved measurements of temperature, pressure, and velocity of NO in an underexpanded free jet

NASA Technical Reports Server (NTRS)

Di Rosa, Michael D.; Chang, Albert Y.; Hanson, Ronald K.

1993-01-01

Gas dynamic quantities within an underexpanded nitrogen free jet, seeded with 0.5 percent NO, were measured nonintrusively by using an intracavity-doubled, rapid-tuning, CW ring dye laser. The UV beam passed obliquely through the jet axis, and its frequency repetitively scanned across adjacent rotational lines in the NO gamma band near 225 nm at a rate of 4 kHz. Spatially resolved excitation scans were obtained by monitoring the induced broadband fluoresence. Modeling the Doppler-shifted excitation scans with Voigt profiles permitted simultaneous determinations of NO velocity, rotational temperature, and pressure. Zero Doppler shift was referenced to an absorption trace obtained across a static cell and recorded concurrently with the excitation scan. Typically, the measured and predicted axial distributions agreed within 10 percent. At high Mach numbers there was evidence of rotational freezing of NO.

THE MASS ACCOMMODATION COEFFICIENT OF AMMONIUM NITRATE AEROSOL. (R823514)

EPA Science Inventory

The mass transfer rate of pure ammonium nitrate between the aerosol and gas phases was
quantified experimentally by the use of the tandem differential mobility analyzer/scanning mobility
particle sizer (TDMA/SMPS) technique. Ammonium nitrate particles 80-220 nm in diameter<...

Column-by-column observation of dislocation motion in CdTe: Dynamic scanning transmission electron microscopy

NASA Astrophysics Data System (ADS)

Li, Chen; Zhang, Yu-Yang; Pennycook, Timothy J.; Wu, Yelong; Lupini, Andrew R.; Paudel, Naba; Pantelides, Sokrates T.; Yan, Yanfa; Pennycook, Stephen J.

2016-10-01

The dynamics of partial dislocations in CdTe have been observed at the atomic scale using aberration-corrected scanning transmission electron microscopy (STEM), allowing the mobility of different dislocations to be directly compared: Cd-core Shockley partial dislocations are more mobile than Te-core partials, and dislocation cores with unpaired columns have higher mobility than those without unpaired columns. The dynamic imaging also provides insight into the process by which the dislocations glide. Dislocations with dangling bonds on unpaired columns are found to be more mobile because the dangling bonds mediate the bond exchanges required for the dislocations to move. Furthermore, a screw dislocation has been resolved to dissociate into a Shockley partial-dislocation pair along two different directions, revealing a way for the screw dislocation to glide in the material. The results show that dynamic STEM imaging has the potential to uncover the details of dislocation motion not easily accessible by other means.

An introduction to QR Codes: linking libraries and mobile patrons.

PubMed

Hoy, Matthew B

2011-01-01

QR codes, or "Quick Response" codes, are two-dimensional barcodes that can be scanned by mobile smartphone cameras. These codes can be used to provide fast access to URLs, telephone numbers, and short passages of text. With the rapid adoption of smartphones, librarians are able to use QR codes to promote services and help library users find materials quickly and independently. This article will explain what QR codes are, discuss how they can be used in the library, and describe issues surrounding their use. A list of resources for generating and scanning QR codes is also provided.

30 CFR 56.14100 - Safety defects; examination, correction and records.

Code of Federal Regulations, 2010 CFR

2010-07-01

... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14100 Safety defects; examination, correction and records. (a) Self-propelled mobile equipment to be used during a shift shall be... defective items including self-propelled mobile equipment shall be taken out of service and placed in a...

Internationalizing Higher Education in Malaysia: Government Policies and University's Response

ERIC Educational Resources Information Center

Tham, Siew Yean

2013-01-01

The intensity of internationalization has increased with an escalation in internationalization activities, leading to increasing student, program, and institutional mobility. In Malaysia, the internationalization of higher education in terms of student mobility has changed tremendously in the last two decades as the country has shifted from a…

Mobility and Hierarchy in the Age of Near-Universal Access

ERIC Educational Resources Information Center

Parry, Gareth

2011-01-01

With the shift toward near-universal access, the movement of students within and between systems of higher education has assumed a new importance, especially for policies aimed at widening participation and social equity. Globalization has given rise to increasing levels of student mobility across national boundaries, with participation in…

Sensitivity and daily quality control of a mobile PET/CT scanner operating in 3-dimensional mode.

PubMed

Belakhlef, Abdelfatihe; Church, Clifford; Fraser, Ron; Lakhanpal, Suresh

2007-12-01

This study investigated the stability of the sensitivity of a mobile PET/CT scanner and tested a phantom experiment to improve on the daily quality control recommendations of the manufacturer. Unlike in-house scanners, mobile PET/CT devices are subjected to a harsher, continuously changing environment that can alter their performance. The parameter of sensitivity was investigated because it reflects directly on standardized uptake value, a key factor in cancer evaluation. A (68)Ge phantom of known activity concentration was scanned 6 times a month for 11 consecutive months using a mobile PET/CT scanner that operates in 3-dimensional mode only. The scans were acquired as 2 contiguous bed positions, with raw data obtained and reconstructed using parameters identical to those used for oncology patients, including CT-extracted attenuation coefficients and decay, scatter, geometry, and randoms corrections. After visual inspection of all reconstructed images, identical regions of interest were drawn on each image to obtain the activity concentration of individual slices. The original activity concentration was then decay-corrected to the scanning day, and the percentage sensitivity of the slice was calculated and graphed. The daily average sensitivity of the scanner, over 11 consecutive months, was also obtained and used to evaluate the stability of sensitivity. Our particular scanner showed a daily average sensitivity ranging from -8.6% to 6.5% except for one instance, when the sensitivity dropped by an unacceptable degree, 34.8%. Our 11-mo follow-up of a mobile PET/CT scanner demonstrated that its sensitivity remained within acceptable clinical limits except for one instance, when the scanner had to be serviced before patients could be imaged. To enhance our confidence in the uniformity of sensitivity across slices, we added a phantom scan to the daily quality control recommendations of the manufacturer.

Polyvinyl Alcohol Microspheres Reinforced Thermoplastic Starch Composites

PubMed Central

Zha, Dongdong; Li, Bengang; Yin, Peng; Li, Panxin

2018-01-01

We reported a new method to prepare polyvinyl alcohol (PVA)/thermoplastic starch (TPS) composites by using polyvinyl alcohol microspheres (PVAMS). The PVAMS/TPS composites were characterized using tensile test, scanning electron microscopy (SEM), dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). The results exhibited that adding small amounts of PVAMSs can effectively improve the mechanical strength and toughness of the composites, especially for the 1 wt %PVAMS in TPS matrix, with a tensile strength of 3.5 MPa, an elongation at break at 71.73% and an impact strength of 33.4 kJ/m2. Furthermore, the SEM and shift in the tan δ peak (Tα and Tβ) at the maximum value of 69.87 and −36.52 °C indicates that the PVAMS decreased the mobility of the amorphous starch molecules due to the strong intermolecular hydrogen bonds between PVAMS and TPS. The peak temperature of maximum decomposition rate (Tp) of 1 wt % PVAMS/TPS composites increased about 5 °C compared with TPS in TGA curves. PMID:29690506

Sleep pattern and decision-making in physicians from mobile emergency care service with 12-h work schedules.

PubMed

Castro, Eleni de Araújo Sales; de Almondes, Katie Moraes

2018-06-01

Shift work schedules are biological standpoint worse because compel the body to anticipate periods of wakefulness and sleep and thus eventually cause a disruption of biological rhythms. The objective of this study is to evaluate the sleep pattern and decision-making in physicians working in mobile units of emergency attention undergoing day shift and rotating shift. The study included 26 physicians. The instruments utilized were a sociodemographic questionnaire, the Pittsburgh Sleep Quality Index, the Sleep Habits Questionnaire, the Epworth Sleepiness Scale and Chronotype Identification Questionnaire of Horne-Ostberg, the Iowa Gambling Task (IGT) and hypothetical scenarios of decision-making created according to the Policy-Capturing Technique. For inclusion and exclusion criteria, the participants answered the Chalder Fatigue Scale, the Beck Anxiety Inventory, the Beck Depression Inventory and the Inventory of Stress Symptoms for adults of Lipp. It was found good sleep quality for physicians on day shift schedule and bad sleep quality for physicians on rotating shift schedule. The IGT measure showed no impairment in decision-making, but the hypothetical scenarios revealed impairment decision-making during the shift for both schedules. Good sleep quality was related to a better performance in decision-making. Good sleep quality seems to influence a better performance in decision-making.

Mobile Gaming and Student Interactions in a Science Center: The Future of Gaming in Science Education

ERIC Educational Resources Information Center

Atwood-Blaine, Dana; Huffman, Douglas

2017-01-01

This article explores the impact of an augmented reality iPad-based mobile game, called The Great STEM Caper, on students' interaction at a science center. An open-source, location-based game platform called ARIS (i.e. Augmented Reality and Interactive Storytelling) was used to create an iPad-based mobile game. The game used QR scan codes and a…

Agarose and Polyacrylamide Gel Electrophoresis Methods for Molecular Mass Analysis of 5–500 kDa Hyaluronan

PubMed Central

Bhilocha, Shardul; Amin, Ripal; Pandya, Monika; Yuan, Han; Tank, Mihir; LoBello, Jaclyn; Shytuhina, Anastasia; Wang, Wenlan; Wisniewski, Hans-Georg; de la Motte, Carol; Cowman, Mary K.

2011-01-01

Agarose and polyacrylamide gel electrophoresis systems for the molecular mass-dependent separation of hyaluronan (HA) in the size range of approximately 5–500 kDa have been investigated. For agarose-based systems, the suitability of different agarose types, agarose concentrations, and buffers systems were determined. Using chemoenzymatically synthesized HA standards of low polydispersity, the molecular mass range was determined for each gel composition, over which the relationship between HA mobility and logarithm of the molecular mass was linear. Excellent linear calibration was obtained for HA molecular mass as low as approximately 9 kDa in agarose gels. For higher resolution separation, and for extension to molecular masses as low as approximately 5 kDa, gradient polyacrylamide gels were superior. Densitometric scanning of stained gels allowed analysis of the range of molecular masses present in a sample, and calculation of weight-average and number-average values. The methods were validated for polydisperse HA samples with viscosity-average molecular masses of 112, 59, 37, and 22 kDa, at sample loads of 0.5 µg (for polyacrylamide) to 2.5 µg (for agarose). Use of the methods for electrophoretic mobility shift assays was demonstrated for binding of the HA-binding region of aggrecan (recombinant human aggrecan G1-IGD-G2 domains) to a 150 kDa HA standard. PMID:21684248

MobileFusion: real-time volumetric surface reconstruction and dense tracking on mobile phones.

PubMed

Ondrúška, Peter; Kohli, Pushmeet; Izadi, Shahram

2015-11-01

We present the first pipeline for real-time volumetric surface reconstruction and dense 6DoF camera tracking running purely on standard, off-the-shelf mobile phones. Using only the embedded RGB camera, our system allows users to scan objects of varying shape, size, and appearance in seconds, with real-time feedback during the capture process. Unlike existing state of the art methods, which produce only point-based 3D models on the phone, or require cloud-based processing, our hybrid GPU/CPU pipeline is unique in that it creates a connected 3D surface model directly on the device at 25Hz. In each frame, we perform dense 6DoF tracking, which continuously registers the RGB input to the incrementally built 3D model, minimizing a noise aware photoconsistency error metric. This is followed by efficient key-frame selection, and dense per-frame stereo matching. These depth maps are fused volumetrically using a method akin to KinectFusion, producing compelling surface models. For each frame, the implicit surface is extracted for live user feedback and pose estimation. We demonstrate scans of a variety of objects, and compare to a Kinect-based baseline, showing on average ∼ 1.5cm error. We qualitatively compare to a state of the art point-based mobile phone method, demonstrating an order of magnitude faster scanning times, and fully connected surface models.

ViRPET--combination of virtual reality and PET brain imaging

DOEpatents

Majewski, Stanislaw; Brefczynski-Lewis, Julie

2017-05-23

Various methods, systems and apparatus are provided for brain imaging during virtual reality stimulation. In one example, among others, a system for virtual ambulatory environment brain imaging includes a mobile brain imager configured to obtain positron emission tomography (PET) scans of a subject in motion, and a virtual reality (VR) system configured to provide one or more stimuli to the subject during the PET scans. In another example, a method for virtual ambulatory environment brain imaging includes providing stimulation to a subject through a virtual reality (VR) system; and obtaining a positron emission tomography (PET) scan of the subject while moving in response to the stimulation from the VR system. The mobile brain imager can be positioned on the subject with an array of imaging photodetector modules distributed about the head of the subject.

Electrophoretic Mobility Shift Assay (EMSA) for Detecting Protein-Nucleic Acid Interactions

PubMed Central

Hellman, Lance M.; Fried, Michael G.

2009-01-01

The gel electrophoresis mobility shift assay (EMSA) is used to detect protein complexes with nucleic acids. It is the core technology underlying a wide range of qualitative and quantitative analyses for the characterization of interacting systems. In the classical assay, solutions of protein and nucleic acid are combined and the resulting mixtures are subjected to electrophoresis under native conditions through polyacrylamide or agarose gel. After electrophoresis, the distribution of species containing nucleic acid is determined, usually by autoradiography of 32P-labeled nucleic acid. In general, protein-nucleic acid complexes migrate more slowly than the corresponding free nucleic acid. In this article, we identify the most important factors that determine the stabilities and electrophoretic mobilities of complexes under assay conditions. A representative protocol is provided and commonly used variants are discussed. Expected outcomes are briefly described. References to extensions of the method and a troubleshooting guide are provided. PMID:17703195

Unusual scintigraphic appearances of a mobile accessory lobe of the liver. [/sup 67/Ga; /sup 99m/Tc-sulfur colloid; /sup 99m/Tc-dihydrothioctic acid

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

Bingham, J.B.; Maisey, M.N.

1978-11-01

Accessory hepatic lobules are an uncommon occurrence. In a gallium scan, a highly mobile, asymptomatic liver lobule gave rise to diagnostic confusion. It was resolved by the use of multiple radiopharmaceuticals.

DMSK: A practical 2400-bps receiver for the mobile satellite service: An MSAT-X Report

NASA Technical Reports Server (NTRS)

Davarian, F.; Simon, M. K.; Sumida, J.

1985-01-01

The partical aspects of a 2400-bps differential detection minimum-shift-keying (DMSK) receiver are investigated. Fundamental issues relating to hardware precision, Doppler shift, fading, and frequency offset are examined, and it is concluded that the receiver's implementation at baseband is more advantageous both in cost and simplicity than its IF implementation. The DMSK receiver has been fabricated and tested under simulated mobile satellite environment conditions. The measured receiver performance in the presence of anomalies pertinent to the link is presented in this report. Furthermore, the receiver behavior in a band-limited channel (GMSK) is also investigated. The DMSK receiver performs substantially better than a coherent minimum-shift-keying (MSK) receiver in a heavily fading environment. The DMSK radio is simple and robust, and results in a lower error floor than its coherent counterpart. Moreover, this receiver is suitable for burst-type signals, and its recovery from deep fades is fast.

Shifting Patterns of Transnational Academic Mobility: A Comparative and Historical Approach

ERIC Educational Resources Information Center

Kim, Terri

2009-01-01

This article is an initial attempt to illustrate how patterns of academic mobility in the history of universities have been framed by the international politics of particular time periods. The article briefly looks at "the medieval period" and then at the emergent colonial and nationalist periods, including the ways that institutions as…

Systematising the Field of Mobile Assisted Language Learning

ERIC Educational Resources Information Center

Viberg, Olga; Grönlund, Åke

2013-01-01

This study provides a systematic review of mobile assisted language (MALL) research within the specific area of second language acquisition (SLA) during the period of 2005-2012 in terms of research approaches, theories and methods, technology, and the linguistic knowledge and skills' results. The findings show a shift from the prevailing SMS-based…

Mobile medical computing driven by the complexity of neurologic diagnosis.

PubMed

Segal, Michael M

2006-07-01

Medical computing has been split between palm-sized computers optimized for mobility and desktop computers optimized for capability. This split was due to technology too immature to deliver both mobility and capability in the same computer and the lack of medical software that demanded both mobility and capability. Advances in hardware and software are ushering in an era in which fully capable computers will be available ubiquitously. As a result, medical practice, education and publishing will change. Medical practice will be improved by the use of software that not only assists with diagnosis but can do so at the bedside, where the doctor can act immediately upon suggestions such as useful findings to check. Medical education will shift away from a focus on details of unusual diseases and toward a focus on skills of physical examination and using computerized tools. Medical publishing, in contrast, will shift toward greater detail: it will be increasingly important to quantitate the frequency of findings in diseases and their time course since such information can have a major impact clinically when added to decision support software.

Recent developments in spectroscopic imaging techniques for historical paintings - A review

NASA Astrophysics Data System (ADS)

Alfeld, M.; de Viguerie, L.

2017-10-01

This paper provides an overview over the application of scanning macro-XRF with mobile instruments for the investigation of historical paintings. The method is compared to synchrotron based macro-XRF imaging and Neutron Activation Auto-Radiography. Full-Field XRF imaging instruments, a potential future alternative to scanning macro-XRF, and confocal XRF, providing complementary depth profiles and developing into a 3D imaging technique itself, are described with the focus on investigations of historical paintings. Recent developments of X-ray radiography are presented and the investigation of cultural heritage objects other than paintings by MA-XRF is summarized. In parallel to XRF, hyperspectral imaging in the visible and range has developed into a technique with comparable capabilities, providing insight in chemical compounds, where XRF imaging identifies the distribution of elements. Due to the complementary nature of these techniques the latter is summarized. Further, progress and state of the art in data evaluation for spectroscopic imaging is discussed. In general it could be observed that technical capabilities in MA-XRF and hyperspectral imaging have reached a plateau and that with the availability of commercial instruments the focus of recent studies has shifted from the development of methods to applications of the instruments. Further, that while simple instruments are easily available with medium budgets only few groups have high-end instrumentation available, bought or in-house built.

The human insulin receptor mRNA contains a functional internal ribosome entry segment

PubMed Central

Spriggs, Keith A.; Cobbold, Laura C.; Ridley, Simon H.; Coldwell, Mark; Bottley, Andrew; Bushell, Martin; Willis, Anne E.; Siddle, Kenneth

2009-01-01

Regulation of mRNA translation is an important mechanism determining the level of expression of proteins in eukaryotic cells. Translation is most commonly initiated by cap-dependent scanning, but many eukaryotic mRNAs contain internal ribosome entry segments (IRESs), providing an alternative means of initiation capable of independent regulation. Here, we show by using dicistronic luciferase reporter vectors that the 5′-UTR of the mRNA encoding human insulin receptor (hIR) contains a functional IRES. RNAi-mediated knockdown showed that the protein PTB was required for maximum IRES activity. Electrophoretic mobility shift assays confirmed that PTB1, PTB2 and nPTB, but not unr or PTB4, bound to hIR mRNA, and deletion mapping implicated a CCU motif 448 nt upstream of the initiator AUG in PTB binding. The IR-IRES was functional in a number of cell lines, and most active in cells of neuronal origin, as assessed by luciferase reporter assays. The IRES was more active in confluent than sub-confluent cells, but activity did not change during differentiation of 3T3-L1 fibroblasts to adipocytes. IRES activity was stimulated by insulin in sub-confluent cells. The IRES may function to maintain expression of IR protein in tissues such as the brain where mRNA translation by cap-dependent scanning is less effective. PMID:19654240

Mobility Effect on Poroelastic Seismic Signatures in Partially Saturated Rocks With Applications in Time-Lapse Monitoring of a Heavy Oil Reservoir

NASA Astrophysics Data System (ADS)

Zhao, Luanxiao; Yuan, Hemin; Yang, Jingkang; Han, De-hua; Geng, Jianhua; Zhou, Rui; Li, Hui; Yao, Qiuliang

2017-11-01

Conventional seismic analysis in partially saturated rocks normally lays emphasis on estimating pore fluid content and saturation, typically ignoring the effect of mobility, which decides the ability of fluids moving in the porous rocks. Deformation resulting from a seismic wave in heterogeneous partially saturated media can cause pore fluid pressure relaxation at mesoscopic scale, thereby making the fluid mobility inherently associated with poroelastic reflectivity. For two typical gas-brine reservoir models, with the given rock and fluid properties, the numerical analysis suggests that variations of patchy fluid saturation, fluid compressibility contrast, and acoustic stiffness of rock frame collectively affect the seismic reflection dependence on mobility. In particular, the realistic compressibility contrast of fluid patches in shallow and deep reservoir environments plays an important role in determining the reflection sensitivity to mobility. We also use a time-lapse seismic data set from a Steam-Assisted Gravity Drainage producing heavy oil reservoir to demonstrate that mobility change coupled with patchy saturation possibly leads to seismic spectral energy shifting from the baseline to monitor line. Our workflow starts from performing seismic spectral analysis on the targeted reflectivity interface. Then, on the basis of mesoscopic fluid pressure diffusion between patches of steam and heavy oil, poroelastic reflectivity modeling is conducted to understand the shift of the central frequency toward low frequencies after the steam injection. The presented results open the possibility of monitoring mobility change of a partially saturated geological formation from dissipation-related seismic attributes.

Combined frequency modulated atomic force microscopy and scanning tunneling microscopy detection for multi-tip scanning probe microscopy applications

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

Morawski, Ireneusz; Institute of Experimental Physics, University of Wrocław, pl. M. Borna 9, 50-204 Wrocław; Spiegelberg, Richard

A method which allows scanning tunneling microscopy (STM) tip biasing independent of the sample bias during frequency modulated atomic force microscopy (AFM) operation is presented. The AFM sensor is supplied by an electronic circuit combining both a frequency shift signal and a tunneling current signal by means of an inductive coupling. This solution enables a control of the tip potential independent of the sample potential. Individual tip biasing is specifically important in order to implement multi-tip STM/AFM applications. An extensional quartz sensor (needle sensor) with a conductive tip is applied to record simultaneously topography and conductivity of the sample. Themore » high resonance frequency of the needle sensor (1 MHz) allows scanning of a large area of the surface being investigated in a reasonably short time. A recipe for the amplitude calibration which is based only on the frequency shift signal and does not require the tip being in contact is presented. Additionally, we show spectral measurements of the mechanical vibration noise of the scanning system used in the investigations.« less

Reaction monitoring using hyperpolarized NMR with scaling of heteronuclear couplings by optimal tracking

NASA Astrophysics Data System (ADS)

Zhang, Guannan; Schilling, Franz; Glaser, Steffen J.; Hilty, Christian

2016-11-01

Off-resonance decoupling using the method of Scaling of Heteronuclear Couplings by Optimal Tracking (SHOT) enables determination of heteronuclear correlations of chemical shifts in single scan NMR spectra. Through modulation of J-coupling evolution by shaped radio frequency pulses, off resonance decoupling using SHOT pulses causes a user-defined dependence of the observed J-splitting, such as the splitting of 13C peaks, on the chemical shift offset of coupled nuclei, such as 1H. Because a decoupling experiment requires only a single scan, this method is suitable for characterizing on-going chemical reactions using hyperpolarization by dissolution dynamic nuclear polarization (D-DNP). We demonstrate the calculation of [13C, 1H] chemical shift correlations of the carbanionic active sites from hyperpolarized styrene polymerized using sodium naphthalene as an initiator. While off resonance decoupling by SHOT pulses does not enhance the resolution in the same way as a 2D NMR spectrum would, the ability to obtain the correlations in single scans makes this method ideal for determination of chemical shifts in on-going reactions on the second time scale. In addition, we present a novel SHOT pulse that allows to scale J-splittings 50% larger than the respective J-coupling constant. This feature can be used to enhance the resolution of the indirectly detected chemical shift and reduce peak overlap, as demonstrated in a model reaction between p-anisaldehyde and isobutylamine. For both pulses, the accuracy is evaluated under changing signal-to-noise ratios (SNR) of the peaks from reactants and reaction products, with an overall standard deviation of chemical shift differences compared to reference spectra of 0.02 ppm when measured on a 400 MHz NMR spectrometer. Notably, the appearance of decoupling side-bands, which scale with peak intensity, appears to be of secondary importance.

Sound Change and Mobility in Los Angeles

ERIC Educational Resources Information Center

Johnson, Lawrence

1975-01-01

Deals with the shift of the low-back vowel as in 'caught' to a low-central vowel as in 'cot' thereby merging such pairs as caught/cot, dawn/Don, and stalk/stock. The causes and the sociolinguistic implications of this shift are discussed. The majority of the informants were from West Los Angeles. (TL)

Robust multiperson detection and tracking for mobile service and social robots.

PubMed

Li, Liyuan; Yan, Shuicheng; Yu, Xinguo; Tan, Yeow Kee; Li, Haizhou

2012-10-01

This paper proposes an efficient system which integrates multiple vision models for robust multiperson detection and tracking for mobile service and social robots in public environments. The core technique is a novel maximum likelihood (ML)-based algorithm which combines the multimodel detections in mean-shift tracking. First, a likelihood probability which integrates detections and similarity to local appearance is defined. Then, an expectation-maximization (EM)-like mean-shift algorithm is derived under the ML framework. In each iteration, the E-step estimates the associations to the detections, and the M-step locates the new position according to the ML criterion. To be robust to the complex crowded scenarios for multiperson tracking, an improved sequential strategy to perform the mean-shift tracking is proposed. Under this strategy, human objects are tracked sequentially according to their priority order. To balance the efficiency and robustness for real-time performance, at each stage, the first two objects from the list of the priority order are tested, and the one with the higher score is selected. The proposed method has been successfully implemented on real-world service and social robots. The vision system integrates stereo-based and histograms-of-oriented-gradients-based human detections, occlusion reasoning, and sequential mean-shift tracking. Various examples to show the advantages and robustness of the proposed system for multiperson tracking from mobile robots are presented. Quantitative evaluations on the performance of multiperson tracking are also performed. Experimental results indicate that significant improvements have been achieved by using the proposed method.

Policy 2.0 Platform for Mobile Sensing and Incentivized Targeted Shifts in Mobility Behavior

PubMed Central

Semanjski, Ivana; Lopez Aguirre, Angel Javier; De Mol, Johan; Gautama, Sidharta

2016-01-01

Sustainable mobility and smart mobility management play important roles in achieving smart cities’ goals. In this context we investigate the role of smartphones as mobility behavior sensors and evaluate the responsivity of different attitudinal profiles towards personalized route suggestion incentives delivered via mobile phones. The empirical results are based on mobile sensed data collected from more than 3400 people’s real life over a period of six months. The findings show which user profiles are most likely to accept such incentives and how likely they are to result in more sustainable mode choices. In addition we provide insights into tendencies towards accepting more sustainable route options for different trip purposes and illustrate smart city platform potential (for collection of mobility behavior data and delivery of incentives) as a tool for development of personalized mobility management campaigns and policies. PMID:27399700

Time-resolved coherent Raman spectroscopy by high-speed pump-probe delay scanning.

PubMed

Domingue, S R; Winters, D G; Bartels, R A

2014-07-15

Using a spinning window pump-probe delay scanner, we demonstrate a means of acquiring time-resolved vibrational spectra at rates up to 700 Hz. The time-dependent phase shift accumulated by the probe pulse in the presence of a coherently vibrating sample gives rise to a Raman-induced frequency shifting readily detectable in a balanced detector. This rapid delay scanning system represents a 23-fold increase in averaging speed and is >10× faster than state-of-the-art voice coil delay lines. These advancements make pump-probe spectroscopy a more practical means of imaging complex media.

Interpretation of Brain CT Scans in the Field by Critical Care Physicians in a Mobile Stroke Unit

PubMed Central

Zakariassen, Erik; Lindner, Thomas; Nome, Terje; Bache, Kristi G.; Røislien, Jo; Gleditsch, Jostein; Solyga, Volker; Russell, David; Lund, Christian G.

2017-01-01

ABSTRACT BACKGROUND AND PURPOSE In acute stroke, thromboembolism or spontaneous hemorrhage abruptly reduces blood flow to a part of the brain. To limit necrosis, rapid radiological identification of the pathological mechanism must be conducted to allow the initiation of targeted treatment. The aim of the Norwegian Acute Stroke Prehospital Project is to determine if anesthesiologists, trained in prehospital critical care, may accurately assess cerebral computed tomography (CT) scans in a mobile stroke unit (MSU). METHODS In this pilot study, 13 anesthesiologists assessed unselected acute stroke patients with a cerebral CT scan in an MSU. The scans were simultaneously available by teleradiology at the receiving hospital and the on‐call radiologist. CT scan interpretation was focused on the radiological diagnosis of acute stroke and contraindications for thrombolysis. The aim of this study was to find inter‐rater agreement between the pre‐ and in‐hospital radiological assessments. A neuroradiologist evaluated all CT scans retrospectively. Statistical analysis of inter‐rater agreement was analyzed with Cohen's kappa. RESULTS Fifty‐one cerebral CT scans from the MSU were included. Inter‐rater agreement between prehospital anesthesiologists and the in‐hospital on‐call radiologists was excellent in finding radiological selection for thrombolysis (kappa .87). Prehospital CT scans were conducted in median 10 minutes (7 and 14 minutes) in the MSU, and median 39 minutes (31 and 48 minutes) before arrival at the receiving hospital. CONCLUSION This pilot study shows that anesthesiologists trained in prehospital critical care may effectively assess cerebral CT scans in an MSU, and determine if there are radiological contraindications for thrombolysis. PMID:28766306

Gel shift analysis of the empA promoter region in Vibrio anguillarum.

PubMed

Denkin, Steven M; Sekaric, Pedja; Nelson, David R

2004-10-29

The induction of metalloprotease encoded by empA in Vibrio anguillarum occurs at high cell density in salmon intestinal mucus. Previously we have shown that there are significant differences in empA expression in two strains of V. anguillarum, M93Sm and NB10. It is hypothesized that differences in empA regulation are due to differences in binding of regulatory elements. Two strains of V. anguillarum, M93Sm and NB10, were examined and compared for the presence of DNA regulatory proteins that bind to and control the empA promoter region. Gel mobility shift assays, using a digoxigenin (DIG)-labeled oligomer containing a lux box-like element and the promoter for empA, were done to demonstrate the presence of a DNA-binding protein. Protein extracts from NB10 cells incubated in Luria Bertani broth + 2% NaCl (LB20), nine salts solution + 200 microg/ml mucus (NSSM), 3M (marine minimal medium), or NSS resulted in a gel mobility shift. No gel mobility shift was seen when protein extracts from either LB20- or NSSM-grown M93Sm cells were mixed with the DIG-labeled empA oligomer. The azocasein assay detected protease activity in all incubation conditions for NB10 culture supernatants. In contrast, protease activity was detected in M93Sm culture supernatants only when incubated in NSSM. Since the luxR homologue in V. anguillarum, vanT, has been cloned, sequenced, and shown to be required for protease activity, we wanted to determine if vanT mutants of NB10 exhibit the same gel shift observed in the wild-type. Site-directed mutagenesis was used to create vanT mutants in V. anguillarum M93Sm and NB10 to test whether VanT is involved with the gel mobility shift. Both vanT mutants, M02 and NB02, did not produce protease activity in any conditions. However, protein extracts from NB02 incubated in each condition still exhibited a gel shift when mixed with the DIG-labeled empA oligomer. The data demonstrate that protein extracts of V. anguillarum NB10 cells contain a protein that binds to a 50 bp oligomer containing the empA promoter-lux box-like region. NB10 cells express empA during stationary phase in all growth conditions. The DNA binding protein is not present in M93Sm extracts. M93Sm cells express protease activity only when incubated at high cell density in fish gastrointestinal mucus. The gel shift observed with NB10 cells is not due to VanT binding. The data also suggest that the DNA binding protein is responsible for the less restrictive expression of empA in NB10 compared to M93Sm.

Intrapetrous Internal Carotid Artery: Evaluation of Exposure, Mobilization and Surgical Maneuvers Feasibility from a Retrosigmoid Approach in a Cadaveric Model.

PubMed

Scerrati, Alba; Ercan, Serdar; Wu, Pengfei; Zhang, Jun; Ammirati, Mario

2016-07-01

To provide a quantification of the exposure of the vertical and horizontal segments of the intrapetrous carotid artery (IPCA) and to evaluate the possibilities of its mobilization and of performing surgical maneuvers on it using the retrosigmoid approach. Twelve surgical dissections were performed bilaterally on 6 fresh cadavers. Predissection computed tomography (CT) scans with bone fiducials for intraoperative navigation were acquired. A retrosigmoid craniectomy was performed. The inframeatal space was drilled, the horizontal (HoIPCA) and vertical (VeIPCA) segments of the IPCA were exposed, and their measurements were recorded. The carotid canal was enlarged, the artery was carefully detached from the bone, and a vessel loop was inserted in order to mobilize its horizontal segment. Afterwards we performed different surgical maneuvers: We inflated a 5-French Fogarty balloon to compress the IPCA and repaired a 7-mm arteriotomy with a running suture. Specimens underwent a new CT scan to evaluate the amount of bone removal and the integrity of the inner ear structures. The HoIPCA and VeIPCA were exposed and anatomically preserved in all specimens without injuring the surrounding neurovascular structures. The HoIPCA presented an average length of 24.89 mm (range: 19.41-31.47 mm), and the VeIPCA presented an average length of 10.07 mm (range: 8.92-11.58 mm). The possibility of IPCA mobilization and the feasibility of performing surgical maneuvers were demonstrated. Postdissection CT scan showed the preservation of inner ear structures. Exposure and mobilization of the IPCA using a retrosigmoid approach are feasible and could represent a viable option for the possibility of reaching a total resection of selected skull base tumors, even when involvement of the carotid canal is present. Published by Elsevier Inc.

A Seamless Learning Design for Mobile Assisted Language Learning: An Iranian Context

ERIC Educational Resources Information Center

Foomani, Elham Mohammadi; Hedayati, Mohsen

2016-01-01

Recent developments in information communication technology (ICT) have resulted in a paradigm shift in e-Learning and there is a growing interest in developing design-based research (DBR) focusing on learners and their involvement in knowledge sharing in a contextualized mode. The present study reports a mobile-assisted language learning (MALL)…

Color intensity projections: A rapid approach for evaluating four-dimensional CT scans in treatment planning

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

Cover, Keith S.; Lagerwaard, Frank J.; Senan, Suresh

2006-03-01

Purpose: Four-dimensional computerized tomography scans (4DCT) enable intrafractional motion to be determined. Because more than 1500 images can be generated with each 4DCT study, tools for efficient data visualization and evaluation are needed. We describe the use of color intensity projections (CIP) for visualizing mobility. Methods: Four-dimensional computerized tomography images of each patient slice were combined into a CIP composite image. Pixels largely unchanged over the component images appear unchanged in the CIP image. However, pixels whose intensity changes over the phases of the 4DCT appear in the CIP image as colored pixels, and the hue encodes the percentage ofmore » time the tissue was in each location. CIPs of 18 patients were used to study tumor and surrogate markers, namely the diaphragm and an abdominal marker block. Results: Color intensity projections permitted mobility of high-contrast features to be quickly visualized and measured. In three selected expiratory phases ('gating phases') that were reviewed in the sagittal plane, gating would have reduced mean tumor mobility from 6.3 {+-} 2.0 mm to 1.4 {+-} 0.5 mm. Residual tumor mobility in gating phases better correlated with residual mobility of the marker block than that of the diaphragm. Conclusion: CIPs permit immediate visualization of mobility in 4DCT images and simplify the selection of appropriate surrogates for gated radiotherapy.« less

From teaching to learning in a mobile, wireless world.

PubMed

Billings, Diane M

2005-08-01

What research evidence justifies this shift from teaching to learning in the mobile, wireless world? We do not need evidence to answer questions such as, "Will the mobile, wireless device technology support teaching and learning?" (we already know it will), or "Will distance learning with mobile, wireless devices be as effective as that in the classroom?" (abundant evidence indicates there will be no significant differences). However, we do need to know, "How can we use these learning technologies to improve student learning and the outcomes of our academic programs?" Answers to this question will ultimately help educators prepare students to deliver safe and competent patient care in the mobile, wireless world.

Comparison of High-Flexion Fixed-Bearing and High-Flexion Mobile-Bearing Total Knee Arthroplasties-A Prospective Randomized Study.

PubMed

Kim, Young-Hoo; Park, Jang-Won; Kim, Jun-Shik

2018-01-01

There is none, to our knowledge, about comparison of high-flexion fixed-bearing and high-flexion mobile-bearing total knee arthroplasties (TKAs) in the same patients. The purpose of this study was to determine whether clinical results; radiographic and computed tomographic scan results; and the survival rate of a high-flexion mobile-bearing TKA is better than that of a high-flexion fixed-bearing TKA. The present study consisted of 92 patients (184 knees) who underwent same-day bilateral TKA. Of those, 17 were men and 75 were women. The mean age at the time of index arthroplasty was 61.5 ± 8.3 years (range 52-65 years). The mean body mass index was 26.2 ± 3.3 kg/m 2 (range 23-34 kg/m 2 ). The mean follow-up was 11.2 years (range 10-12 years). The Knee Society knee scores (93 vs 92 points; P = .531) and function scores (80 vs 80 points; P = 1.000), WOMAC scores (14 vs 15 points; P = .972), and UCLA activity scores (6 vs 6 points; P = 1.000) were not different between the 2 groups at 12 years follow-up. There were no differences in any radiographic and CT scan parameters between the 2 groups. Kaplan-Meier survivorship of the TKA component was 98% (95% confidence interval, 93-100) in the high-flexion fixed-bearing TKA group and 99% (95% confidence interval, 94-100) in the high-flexion mobile-bearing TKA group 12 years after the operation. We found no benefit to mobile-bearing TKA in terms of pain, function, radiographic and CT scan results, and survivorship. Longer-term follow-up is necessary to prove the benefit of the high-flexion mobile-bearing TKA over the high-flexion fixed-bearing TKA. Copyright © 2017 Elsevier Inc. All rights reserved.

Mobile Infrared Thermographic Surveys Of Buildings Within A Community

NASA Astrophysics Data System (ADS)

Allen, Sharon

1988-01-01

Over the years, constant developments and improvements have been made in the portability of infrared equipment. The ability to move around and travel from job to job easily greatly enhances the effectiveness of most in-field infrared thermographic surveys. Many vehicles have been modified to offer mobile infrared thermographic services. This paper describes one approach, and the results, to mobile infrared thermography. It covers the various stages in adapting a vehicle for mobile infrared thermography (IR) and problems encountered along the way. Originally designed for scanning electrical distribution lines, the "IR Van" also serves as a mobile unit for building diagnostics. The paper addresses building diagnostic applications for mobile IR and some of the findings recorded during an initial community investigation.

Determination of smoke plume and layer heights using scanning lidar data

Treesearch

Vladimir A. Kovalev; Alexander Petkov; Cyle Wold; Shawn Urbanski; Wei Min Hao

2009-01-01

The methodology of using mobile scanning lidar data for investigation of smoke plume rise and high-resolution smoke dispersion is considered. The methodology is based on the lidar-signal transformation proposed recently [Appl. Opt. 48, 2559 (2009)]. In this study, similar methodology is used to create the atmospheric heterogeneity height indicator (HHI...

Phase-contrast scanning transmission electron microscopy.

PubMed

Minoda, Hiroki; Tamai, Takayuki; Iijima, Hirofumi; Hosokawa, Fumio; Kondo, Yukihito

2015-06-01

This report introduces the first results obtained using phase-contrast scanning transmission electron microscopy (P-STEM). A carbon-film phase plate (PP) with a small center hole is placed in the condenser aperture plane so that a phase shift is introduced in the incident electron waves except those passing through the center hole. A cosine-type phase-contrast transfer function emerges when the phase-shifted scattered waves interfere with the non-phase-shifted unscattered waves, which passed through the center hole before incidence onto the specimen. The phase contrast resulting in P-STEM is optically identical to that in phase-contrast transmission electron microscopy that is used to provide high contrast for weak phase objects. Therefore, the use of PPs can enhance the phase contrast of the STEM images of specimens in principle. The phase shift resulting from the PP, whose thickness corresponds to a phase shift of π, has been confirmed using interference fringes displayed in the Ronchigram of a silicon single crystal specimen. The interference fringes were found to abruptly shift at the edge of the PP hole by π. © The Author 2015. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Comparisons of lesion detectability in ultrasound images acquired using time-shift compensation and spatial compounding.

PubMed

Lacefield, James C; Pilkington, Wayne C; Waag, Robert C

2004-12-01

The effects of aberration, time-shift compensation, and spatial compounding on the discrimination of positive-contrast lesions in ultrasound b-scan images are investigated using a two-dimensional (2-D) array system and tissue-mimicking phantoms. Images were acquired within an 8.8 x 12-mm2 field of view centered on one of four statistically similar 4-mm diameter spherical lesions. Each lesion was imaged in four planes offset by successive 45 degree rotations about the central scan line. Images of the lesions were acquired using conventional geometric focusing through a water path, geometric focusing through a 35-mm thick distributed aberration phantom, and time-shift compensated transmit and receive focusing through the aberration phantom. The views of each lesion were averaged to form sets of water path, aberrated, and time-shift compensated 4:1 compound images and 16:1 compound images. The contrast ratio and detectability index of each image were computed to assess lesion differentiation. In the presence of aberration representative of breast or abdominal wall tissue, time-shift compensation provided statistically significant improvements of contrast ratio but did not consistently affect the detectability index, and spatial compounding significantly increased the detectability index but did not alter the contrast ratio. Time-shift compensation and spatial compounding thus provide complementary benefits to lesion detection.

Implications of Shifting Technology in Education

ERIC Educational Resources Information Center

Holland, Janet; Holland, John

2014-01-01

This article examines the implications of shifting technology trends by looking at what we've lost or are losing, where we are, and where we need to go for making the needed transitions in knowledge and skills. Areas of growth within new media and the tech industry are good indicators of our growing interests in mobility, improved quality,…

Elevational range shifts in four mountain ungulate species from the Swiss Alps

Treesearch

Ulf Büntgen; Lucie Greuter; Kurt Bollmann; Hannes Jenny; Andrew Liebhold; J. Diego Galván; Nils C. Stenseth; Carrie Andrew; Atle Mysterud

2017-01-01

Warming-induced range shifts along elevational and latitudinal gradients have been observed in several species from various taxa. The mobility and behavioral plasticity of large endothermic mammals, however, complicate the detection of climatic effects on their spatial distributions. Here, we analyzed 230,565 hunting locations of the four most abundant ungulate species...

Exercise leads to faster postural reflexes, improved balance and mobility, and fewer falls in older persons with chronic stroke.

PubMed

Marigold, Daniel S; Eng, Janice J; Dawson, Andrew S; Inglis, J Timothy; Harris, Jocelyn E; Gylfadóttir, Sif

2005-03-01

To determine the effect of two different community-based group exercise programs on functional balance, mobility, postural reflexes, and falls in older adults with chronic stroke. A randomized, clinical trial. Community center. Sixty-one community-dwelling older adults with chronic stroke. Participants were randomly assigned to an agility (n=30) or stretching/weight-shifting (n=31) exercise group. Both groups exercised three times a week for 10 weeks. Participants were assessed before, immediately after, and 1 month after the intervention for Berg Balance, Timed Up and Go, step reaction time, Activities-specific Balance Confidence, and Nottingham Health Profile. Testing of standing postural reflexes and induced falls evoked by a translating platform was also performed. In addition, falls in the community were tracked for 1 year from the start of the interventions. Although exercise led to improvements in all clinical outcome measures for both groups, the agility group demonstrated greater improvement in step reaction time and paretic rectus femoris postural reflex onset latency than the stretching/weight-shifting group. In addition, the agility group experienced fewer induced falls on the platform. Group exercise programs that include agility or stretching/weight shifting exercises improve postural reflexes, functional balance, and mobility and may lead to a reduction of falls in older adults with stroke.

RAPID IDENTIFICATION OF MICROORGANISMS BY CONTINUOUS PARTICLE ELECTROPHORESIS.

DTIC Science & Technology

MICROORGANISMS, IDENTIFICATION), (*ELECTROPHORESIS, MICROORGANISMS), MOBILITY, PH FACTOR, OPTICAL SCANNING, ESCHERICHIA COLI, SHIGELLA FLEXNERI, BACILLUS CEREUS, SERRATIA MARCESCENS , BACILLUS SUBTILIS

Multimedia Messaging Service teleradiology in the provision of emergency neurosurgery services.

PubMed

Ng, Wai Hoe; Wang, Ernest; Ng, Ivan

2007-04-01

Neurosurgical emergencies constitute a significant proportion of workload of a tertiary neurosurgical service. Prompt diagnosis and emergent institution of definitive treatment are critical to reduce neurological mortality and morbidity. Diagnosis is highly dependent on accurate interpretation of scans by experienced clinicians. This expertise may not be readily available especially after office hours because many neurosurgical units are manned by middle-level neurosurgical staff with varying levels of experience in scan interpretation. Multimedia Messaging Service mobile phone technology offers a simple, cheap, quick, and effective solution to the problem of scan interpretation. An MMS takes only a few minutes to send and receive and allows senior doctors to view important images and make important clinical decisions to enhance patient management in an emergency situation. A mobile phone (with VGA camera and MMS capabilities) was provided to the neurosurgery registrar on call. The on-call mobile phone is passed on to the corresponding registrar on-call the next day. All consultants had personal mobile phones that are MMS-enabled. Relevant representative CT/MRI images can be taken directly from the mobile phone from the PACS off the computer screen. When only hard copies are available, the images can be taken off the light box. After a 12-month trial period, a questionnaire was given to all staff involved in the project to ascertain the usefulness of the MMS teleradiology service. The survey on the use of the MMS service in a tertiary neurosurgical service demonstrated that the technology significantly improved the level of confidence of the senior-level staff in emergent clinical decision making. Significantly, the MMS images were of sufficient quality and resolution to obviate the need to view the actual scans. The impact of MMS is less pronounced in the middle-level staff, but there was a trend that most of the junior staff found the service more useful. The MMS technology is demonstrated to be a useful media for the transmission of high-quality images to assist in the diagnostic process and implementation of emergent clinical therapy. It is already in widespread use and can be seamlessly and rapidly implemented in the clinical arena to improve the quality of patient care.

Exploring mobility & workplace choice in a flexible office through post-occupancy evaluation.

PubMed

Göçer, Özgür; Göçer, Kenan; Ergöz Karahan, Ebru; İlhan Oygür, Işıl

2018-02-01

Developments in information and communication systems, organisational structure and the nature of work have contributed to the restructuring of work environments. In these new types of work environments, employees do not have assigned workplaces. This arrangement helps organisations to minimise rent costs and increase employee interaction and knowledge exchange through mobility. This post-occupancy evaluation (POE) study focuses on a flexible office in a Gold Leadership in Energy and Environmental Design-certified building in Istanbul. An integrated qualitative and quantitative POE technique with occupancy tracking via barcode scanning and instant surveying has been introduced. Using this unique approach, we examined the directives/drivers in workplace choice and mobility from different perspectives. The aggregated data was used to discern work-related consequences such as flexibility, workplace choice, work and indoor environment satisfaction, place attachment and identity. The results show that employees who have a conventional working culture develop a new working style: 'fixed-flexible working'. Practitioner Summary: This paper introduces a new POE approach for flexible offices based on occupancy tracking through barcode scanning to explore workplace choice and mobility. More than half (52.1%) of the participants have tended to choose the same desk every day. However, the satisfaction level of the 'mobile' employees was higher than that of the 'fixed flexible' employees.

Scanning dimensional measurement using laser-trapped microsphere with optical standing-wave scale

NASA Astrophysics Data System (ADS)

Michihata, Masaki; Ueda, Shin-ichi; Takahashi, Satoru; Takamasu, Kiyoshi; Takaya, Yasuhiro

2017-06-01

We propose a laser trapping-based scanning dimensional measurement method for free-form surfaces. We previously developed a laser trapping-based microprobe for three-dimensional coordinate metrology. This probe performs two types of measurements: a tactile coordinate and a scanning measurement in the same coordinate system. The proposed scanning measurement exploits optical interference. A standing-wave field is generated between the laser-trapped microsphere and the measured surface because of the interference from the retroreflected light. The standing-wave field produces an effective length scale, and the trapped microsphere acts as a sensor to read this scale. A horizontal scan of the trapped microsphere produces a phase shift of the standing wave according to the surface topography. This shift can be measured from the change in the microsphere position. The dynamics of the trapped microsphere within the standing-wave field was estimated using a harmonic model, from which the measured surface can be reconstructed. A spherical lens was measured experimentally, yielding a radius of curvature of 2.59 mm, in agreement with the nominal specification (2.60 mm). The difference between the measured points and a spherical fitted curve was 96 nm, which demonstrates the scanning function of the laser trapping-based microprobe for free-form surfaces.

Minimization of spurious strains by using a Si bent-perfect-crystal monochromator: neutron surface strain scanning of a shot-peened sample

NASA Astrophysics Data System (ADS)

Rebelo Kornmeier, Joana; Gibmeier, Jens; Hofmann, Michael

2011-06-01

Neutron strain measurements are critical at the surface. When scanning close to a sample surface, aberration peak shifts arise due to geometrical and divergence effects. These aberration peak shifts can be of the same order as the peak shifts related to residual strains. In this study it will be demonstrated that by optimizing the horizontal bending radius of a Si (4 0 0) monochromator, the aberration peak shifts from surface effects can be strongly reduced. A stress-free sample of fine-grained construction steel, S690QL, was used to find the optimal instrumental conditions to minimize aberration peak shifts. The optimized Si (4 0 0) monochromator and instrument settings were then applied to measure the residual stress depth gradient of a shot-peened SAE 4140 steel sample to validate the effectiveness of the approach. The residual stress depth profile is in good agreement with results obtained by x-ray diffraction measurements from an international round robin test (BRITE-EURAM-project ENSPED). The results open very promising possibilities to bridge the gap between x-ray diffraction and conventional neutron diffraction for non-destructive residual stress analysis close to surfaces.

VirtoScan - a mobile, low-cost photogrammetry setup for fast post-mortem 3D full-body documentations in x-ray computed tomography and autopsy suites.

PubMed

Kottner, Sören; Ebert, Lars C; Ampanozi, Garyfalia; Braun, Marcel; Thali, Michael J; Gascho, Dominic

2017-03-01

Injuries such as bite marks or boot prints can leave distinct patterns on the body's surface and can be used for 3D reconstructions. Although various systems for 3D surface imaging have been introduced in the forensic field, most techniques are both cost-intensive and time-consuming. In this article, we present the VirtoScan, a mobile, multi-camera rig based on close-range photogrammetry. The system can be integrated into automated PMCT scanning procedures or used manually together with lifting carts, autopsy tables and examination couch. The VirtoScan is based on a moveable frame that carries 7 digital single-lens reflex cameras. A remote control is attached to each camera and allows the simultaneous triggering of the shutter release of all cameras. Data acquisition in combination with the PMCT scanning procedures took 3:34 min for the 3D surface documentation of one side of the body compared to 20:20 min of acquisition time when using our in-house standard. A surface model comparison between the high resolution output from our in-house standard and a high resolution model from the multi-camera rig showed a mean surface deviation of 0.36 mm for the whole body scan and 0.13 mm for a second comparison of a detailed section of the scan. The use of the multi-camera rig reduces the acquisition time for whole-body surface documentations in medico-legal examinations and provides a low-cost 3D surface scanning alternative for forensic investigations.

Role of microRNA in Aggressive Prostate Cancer

DTIC Science & Technology

2015-09-01

j.issn.2223-4683.2013.08.01 Scan to your mobile device or view this article at: http://www.amepc.org/tau/article/view/2550/3635 229Translational Andrology...of Ezh2, accompanied with diminished clonogenic ability and sphere formation in PCa cells (45). Another let-7 target gene is High- mobility group AT...2013;32:4139-47. 89. Motoyama K, Inoue H, Nakamura Y, et al. Clinical significance of high mobility group A2 in human gastric cancer and its

Chairs!: A Mobile Game for Organic Chemistry Students to Learn the Ring Flip of Cyclohexane

ERIC Educational Resources Information Center

Winter, Julia; Wentzel, Michael; Ahluwalia, Sonia

2016-01-01

The hallmark of game-based learning is that students discover concepts through trial and error as they play. With the digital landscape in higher education shifting to mobile-first, new tools for learning chemistry are both possible and needed. Interactive games for chemistry bring intuitive content directly to students through their devices. The…

E-bike trials’ potential to promote sustained changes in car owners mobility habits

NASA Astrophysics Data System (ADS)

Moser, Corinne; Blumer, Yann; Lena Hille, Stefanie

2018-04-01

Modal shifts hold considerable potential to mitigate carbon emissions. Electric bikes (e-bikes) represent a promising energy- and carbon-efficient alternative to cars. However, as mobility behaviour is highly habitual, convincing people to switch from cars to e-bikes is challenging. One strategy to accomplish this is the disruption of existing habits—a key idea behind an annual e-bike promotion programme in Switzerland, in which car owners can try out an e-bike for free over a two-week period in exchange for their car keys. By means of a longitudinal survey, we measured the long-term effects of this trial on mobility-related habitual associations. After one year, participants’ habitual association with car use had weakened significantly. This finding was valid both for participants who bought an e-bike after the trial and those who did not. Our findings contrast the results of other studies who find that the effect of interventions to induce modal shifts wears off over time. We conclude that an e-bike trial has the potential to break mobility habits and motivate car owners to use more sustainable means of transport.

Significance of the gate voltage-dependent mobility in the electrical characterization of organic field effect transistors

NASA Astrophysics Data System (ADS)

Kim, Jong Beom; Lee, Dong Ryeol

2018-04-01

We studied the effect of the addition of free hole- and electron-rich organic molecules to organic semiconductors (OSCs) in organic field effect transistors (OFETs) on the gate voltage-dependent mobility. The drain current versus gate voltage characteristics were quantitatively analyzed using an OFET mobility model of power law behavior based on hopping transport in an OSC. This analysis distinguished the threshold voltage shifts, depending on the materials and structures of the OFET device, and properly estimated the hopping transport of the charge carriers induced by the gate bias within the OSC from the power law exponent parameter. The addition of pentacene or C60 molecules to a one-monolayer pentacene-based OFET shifted the threshold voltages negatively or positively, respectively, due to the structural changes that occurred in the OFET device. On the other hand, the power law parameters revealed that the addition of charge carriers of the same or opposite polarity enhanced or hindered hopping transport, respectively. This study revealed the need for a quantitative analysis of the gate voltage-dependent mobility while distinguishing this effect from the threshold voltage effect in order to understand OSC hopping transport in OFETs.

Relationship Between the Elevated Muscle FDG Uptake in the Distal Upper Extremities on PET/CT Scan and Prescan Utilization of Mobile Devices in Young Patients.

PubMed

Bai, Xia; Wang, Xuemei; Zhuang, Hongming

2018-03-01

It is common to notice increased FDG activity in the muscles of the forearms or hands on PET/CT images. The purpose of this study was to determine relationship between the prevalence of increased FDG activity in the forearms or hands and using mobile devices prior to the FDG PET/CT study. A total of 443 young patients with ages between 5 and 19 years who underwent FDG PET/CT scan were included in this retrospective analysis. All patients had FDG PET/CT with their arms within the field of views. The images were reviewed for elevated activity in the muscles of the distal upper extremities (DUEs), which include forearms and hands. The preimaging questionnaire/interview records regarding using mobile devices prior to FDG PET/CT were also reviewed and compared with the imaging findings. Most patients (72.0% [319/443]) used mobile devices more than 60 minutes in the period of 24 hours prior to the FDG PET/CT study. Elevated uptake in the muscles in the DUEs was observed in 38.6% (123/319) of these patients. In contrast, among 124 patients who did not use the mobile devices or used the mobile device minimally prior to the study, only 6.5% (8/124) of them had elevated FDG activity in the DUEs. The difference persisted following stratification analysis for sex, age, and serum glucose level in our patient population. Increased FDG uptake in the muscles of the DUEs in young patients is commonly seen in those who used mobile devices prior to PET/CT study. Recommendation should be considered to reduce using mobile devices prior to FDG PET/CT study in young patient population.

Investigation of Defect Distributions in SiO2/AlGaN/GaN High-Electron-Mobility Transistors by Using Capacitance-Voltage Measurement with Resonant Optical Excitation

NASA Astrophysics Data System (ADS)

Kim, Tae-Soo; Lim, Seung-Young; Park, Yong-Keun; Jung, Gunwoo; Song, Jung-Hoon; Cha, Ho-Young; Han, Sang-Woo

2018-06-01

We investigated the distributions and the energy levels of defects in SiO2/AlGaN/GaN highelectron-mobility transistors (HEMTs) by using frequency-dependent ( F- D) capacitance-voltage ( C- V) measurements with resonant optical excitation. A Schottky barrier (SB) and a metal-oxidesemiconductor (MOS) HEMT were prepared to compare the effects of defects in their respective layers. We also investigated the effects of those layers on the threshold voltage ( V th ). A drastic voltage shift in the C- V curve at higher frequencies was caused by the large number of defect levels in the SiO2/GaN interface. A significant shift in V th with additional light illumination was observed due to a charging of the defect states in the SiO2/GaN interface. The voltage shifts were attributed to the detrapping of defect states at the SiO2/GaN interface.

Persistent ecological shifts in marine molluscan assemblages across the end-Cretaceous mass extinction.

PubMed

Aberhan, Martin; Kiessling, Wolfgang

2015-06-09

Contemporary biodiversity loss and population declines threaten to push the biosphere toward a tipping point with irreversible effects on ecosystem composition and function. As a potential example of a global-scale regime shift in the geological past, we assessed ecological changes across the end-Cretaceous mass extinction based on molluscan assemblages at four well-studied sites. By contrasting preextinction and postextinction rank abundance and numerical abundance in 19 molluscan modes of life--each defined as a unique combination of mobility level, feeding mode, and position relative to the substrate--we find distinct shifts in ecospace utilization, which significantly exceed predictions from null models. The magnitude of change in functional traits relative to normal temporal fluctuations at far-flung sites indicates that molluscan assemblages shifted to differently structured systems and faunal response was global. The strengths of temporal ecological shifts, however, are mostly within the range of preextinction site-to-site variability, demonstrating that local ecological turnover was similar to geographic variation over a broad latitudinal range. In conjunction with varied site-specific temporal patterns of individual modes of life, these spatial and temporal heterogeneities argue against a concerted phase shift of molluscan assemblages from one well-defined regime to another. At a broader ecological level, by contrast, congruent tendencies emerge and suggest deterministic processes. These patterns comprise the well-known increase of deposit-feeding mollusks in postextinction assemblages and increases in predators and predator-resistant modes of life, i.e., those characterized by elevated mobility and infaunal life habits.

Utilization of a Terrestrial Laser Scanner for the Calibration of Mobile Mapping Systems

PubMed Central

Hong, Seunghwan; Park, Ilsuk; Lee, Jisang; Lim, Kwangyong; Choi, Yoonjo; Sohn, Hong-Gyoo

2017-01-01

This paper proposes a practical calibration solution for estimating the boresight and lever-arm parameters of the sensors mounted on a Mobile Mapping System (MMS). On our MMS devised for conducting the calibration experiment, three network video cameras, one mobile laser scanner, and one Global Navigation Satellite System (GNSS)/Inertial Navigation System (INS) were mounted. The geometric relationships between three sensors were solved by the proposed calibration, considering the GNSS/INS as one unit sensor. Our solution basically uses the point cloud generated by a 3-dimensional (3D) terrestrial laser scanner rather than using conventionally obtained 3D ground control features. With the terrestrial laser scanner, accurate and precise reference data could be produced and the plane features corresponding with the sparse mobile laser scanning data could be determined with high precision. Furthermore, corresponding point features could be extracted from the dense terrestrial laser scanning data and the images captured by the video cameras. The parameters of the boresight and the lever-arm were calculated based on the least squares approach and the precision of the boresight and lever-arm could be achieved by 0.1 degrees and 10 mm, respectively. PMID:28264457

Gel shift analysis of the empA promoter region in Vibrio anguillarum

PubMed Central

Denkin, Steven M; Sekaric, Pedja; Nelson, David R

2004-01-01

Background The induction of metalloprotease encoded by empA in Vibrio anguillarum occurs at high cell density in salmon intestinal mucus. Previously we have shown that there are significant differences in empA expression in two strains of V. anguillarum, M93Sm and NB10. It is hypothesized that differences in empA regulation are due to differences in binding of regulatory elements. Results Two strains of V. anguillarum, M93Sm and NB10, were examined and compared for the presence of DNA regulatory proteins that bind to and control the empA promoter region. Gel mobility shift assays, using a digoxigenin (DIG)-labeled oligomer containing a lux box-like element and the promoter for empA, were done to demonstrate the presence of a DNA-binding protein. Protein extracts from NB10 cells incubated in Luria Bertani broth + 2% NaCl (LB20), nine salts solution + 200 μg/ml mucus (NSSM), 3M (marine minimal medium), or NSS resulted in a gel mobility shift. No gel mobility shift was seen when protein extracts from either LB20- or NSSM-grown M93Sm cells were mixed with the DIG-labeled empA oligomer. The azocasein assay detected protease activity in all incubation conditions for NB10 culture supernatants. In contrast, protease activity was detected in M93Sm culture supernatants only when incubated in NSSM. Since the luxR homologue in V. anguillarum, vanT, has been cloned, sequenced, and shown to be required for protease activity, we wanted to determine if vanT mutants of NB10 exhibit the same gel shift observed in the wild-type. Site-directed mutagenesis was used to create vanT mutants in V. anguillarum M93Sm and NB10 to test whether VanT is involved with the gel mobility shift. Both vanT mutants, M02 and NB02, did not produce protease activity in any conditions. However, protein extracts from NB02 incubated in each condition still exhibited a gel shift when mixed with the DIG-labeled empA oligomer. Conclusions The data demonstrate that protein extracts of V. anguillarum NB10 cells contain a protein that binds to a 50 bp oligomer containing the empA promoter-lux box-like region. NB10 cells express empA during stationary phase in all growth conditions. The DNA binding protein is not present in M93Sm extracts. M93Sm cells express protease activity only when incubated at high cell density in fish gastrointestinal mucus. The gel shift observed with NB10 cells is not due to VanT binding. The data also suggest that the DNA binding protein is responsible for the less restrictive expression of empA in NB10 compared to M93Sm. PMID:15516264

NARSTO EPA SS PITTSBURGH GAS PM PROPERTY DATA

Atmospheric Science Data Center

2018-04-09

... Sizer Nephelometer Aerosol Collector SMPS - Scanning Mobility Particle Sizer Fluorescence Spectroscopy ... Get Google Earth Related Data:  Environmental Protection Agency Supersites Pittsburgh, Pennsylvania ...

a Man-Portable Imu-Free Mobile Mapping System

NASA Astrophysics Data System (ADS)

Nüchter, A.; Borrmann, D.; Koch, P.; Kühn, M.; May, S.

2015-08-01

Mobile mapping systems are commonly mounted on cars, ships and robots. The data is directly geo-referenced using GPS data and expensive IMU (inertial measurement systems). Driven by the need for flexible, indoor mapping systems we present an inexpensive mobile mapping solution that can be mounted on a backpack. It combines a horizontally mounted 2D profiler with a constantly spinning 3D laser scanner. The initial system featuring a low-cost MEMS IMU was revealed and demonstrated at MoLaS: Technology Workshop Mobile Laser Scanning at Fraunhofer IPM in Freiburg in November 2014. In this paper, we present an IMU-free solution.

Electrical and structural studies of polymer electrolyte based on chitosan/methyl cellulose blend doped with BMIMTFSI

NASA Astrophysics Data System (ADS)

Misenan, M. S. M.; Isa, M. I. N.; Khiar, A. S. A.

2018-05-01

In this study, blended polymer electrolyte of methylcellulose (MC)/chitosan (CS) was prepared with different weight percentage of 1-butyl-3-methylimidazolium bis(trifluoromethyl sulfonyl) imide (BMIMTFSI) which acts as ion donor. This polymer blend was prepared by solution casting technique. The micro structure was observed by Field Emission Scanning Electron Microscopy (FESEM) where the multilayer could possibly be ascribed to the limited chain mobility. Sample having 60 wt% CS: 40 wt% MC was determined to have the most amorphous morphology extracted using deconvoluted data from x-ray Diffractography (XRD). Fourier Transform Infrared Spectroscopy (FTIR) peaks analysis shows the significant shift indicates complexation between ionic liquid and polymer backbone. The film was also characterized by impedance spectroscopy to measure its ionic conductivity. Samples with 45% of BMITFSI exhibit the highest conductivity of (1.51 ± 0.13) × 10‑6 S cm‑1 at ambient. Conductivity at elevated temperature was also studied, and the electrolytes obeys the Arrhenius behaviour. The conduction mechanism was best presented by small polaron hopping model.

Structural and optical properties of the ZnS/GaSe heterojunctions

NASA Astrophysics Data System (ADS)

Alharbi, S. R.; Abdallaha, Maisam M. A.; Qasrawi, A. F.

2017-11-01

In the current work, the ZnS/GaSe thin film heterojunction interfaces are experimentally designed and characterized by means of x-ray diffraction, scanning electron microscopy, energy dispersion spectroscopy and optical spectroscopy techniques. The heterojunction is observed to exhibit physical nature of formation with an induced crystallization of GaSe by the ZnS substrate. For this heterojunction, the hot probe technique suggested the formation of a p-ZnS/n-GaSe interface. In addition, the designed energy band diagram of the heterojunction which was actualized with the help of the optical spectrophotometric data analysis revealed a respective conduction and valence band offsets of 0.67 and 0.73 eV. On the other hand, the dielectric dispersion analysis and modeling which was studied in the frequency range of 270-1000 THz, have shown that the interfacing of the ZnS with GaSe strongly affects the properties of ZnS as it reduces the number of free carriers, shifts down the plasmon frequency, increases the charge carrier scattering time and results in higher values of drift mobility at Terahertz frequencies.

A homeodomain transcription factor gene, PfMSX, activates expression of Pif gene in the pearl oyster Pinctada fucata.

PubMed

Zhao, Mi; He, Maoxian; Huang, Xiande; Wang, Qi

2014-01-01

We reported pearl oyster Pinctada fucata cDNA and genomic characterization of a new homeobox-containing protein, PfMSX. The PfMSX gene encodes a transcription factor that was localized to the nucleus. Analyses of PfMSX mRNA in tissues and developmental stages showed high expressions in mantle or D-shaped larvae. In electrophoretic mobility shift assays (EMSAs) PfMSX binded to MSX consensus binding sites in the 5' flanking region of the Pif promoter. In co-transfection experiment PfMSX transactivated reporter constructs containing Pif promoter sequences, and mutation of the MSX-binding sites attenuated transactivation. A knockdown experiment using PfMSX dsRNA showed decreased Pif mRNA and unregular crystallization of the nacreous layer using scanning electron microscopy. Our results suggested that PfMSX was a conserved homeodomain transcription factor gene, which can activate Pif gene expression through MSX binding site, and was then involved in the mineralization process in pearl oyster Pinctada fucata. Our data provided important clues about mechanisms regulating biomineralization in pearl oyster.

A Homeodomain Transcription Factor Gene, PfMSX, Activates Expression of Pif Gene in the Pearl Oyster Pinctada fucata

PubMed Central

Zhao, Mi; He, Maoxian; Huang, Xiande; Wang, Qi

2014-01-01

We reported pearl oyster Pinctada fucata cDNA and genomic characterization of a new homeobox-containing protein, PfMSX. The PfMSX gene encodes a transcription factor that was localized to the nucleus. Analyses of PfMSX mRNA in tissues and developmental stages showed high expressions in mantle or D-shaped larvae. In electrophoretic mobility shift assays (EMSAs) PfMSX binded to MSX consensus binding sites in the 5′ flanking region of the Pif promoter. In co-transfection experiment PfMSX transactivated reporter constructs containing Pif promoter sequences, and mutation of the MSX-binding sites attenuated transactivation. A knockdown experiment using PfMSX dsRNA showed decreased Pif mRNA and unregular crystallization of the nacreous layer using scanning electron microscopy. Our results suggested that PfMSX was a conserved homeodomain transcription factor gene, which can activate Pif gene expression through MSX binding site, and was then involved in the mineralization process in pearl oyster Pinctada fucata. Our data provided important clues about mechanisms regulating biomineralization in pearl oyster. PMID:25099698

Gasoline from coal in the state of Illinois: feasibility study. Volume I. Design. [KBW gasification process, ICI low-pressure methanol process and Mobil M-gasoline process

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

Not Available

1980-01-01

Volume 1 describes the proposed plant: KBW gasification process, ICI low-pressure methanol process and Mobil M-gasoline process, and also with ancillary processes, such as oxygen plant, shift process, RECTISOL purification process, sulfur recovery equipment and pollution control equipment. Numerous engineering diagrams are included. (LTN)

Short-Term Study Tours as a Driver for Increasing Domestic Student Mobility in Order to Generate Global Work-Ready Students and Cultural Exchange in Asia Pacific

ERIC Educational Resources Information Center

Scharoun, Lisa

2016-01-01

Recent federal government programmes in Australia have seen a shift in focus from the international student towards increasing the possibilities for domestic mobility through short- and long-term exchange opportunities. The current New Colombo Plan funding scheme encourages Australian students, who have traditionally undertaken semester-long…

A Multi-Case Study of Research Using Mobile Imaging, Sensing and Tracking Technologies to Objectively Measure Behavior: Ethical Issues and Insights to Guide Responsible Research Practice

ERIC Educational Resources Information Center

Nebeker, Camille; Linares-Orozco, Rubi; Crist, Katie

2015-01-01

Introduction: The increased availability of mobile sensing technologies is creating a paradigm shift for health research by creating new opportunities for measuring and monitoring behavior. For example, researchers can now collect objective information about a participant's daily activity using wearable devices that have: 1- Global Positioning…

Use of Mobile Clinical Decision Support Software by Junior Doctors at a UK Teaching Hospital: Identification and Evaluation of Barriers to Engagement.

PubMed

Patel, Rakesh; Green, William; Shahzad, Muhammad Waseem; Larkin, Chris

2015-08-13

Clinical decision support (CDS) tools improve clinical diagnostic decision making and patient safety. The availability of CDS to health care professionals has grown in line with the increased prevalence of apps and smart mobile devices. Despite these benefits, patients may have safety concerns about the use of mobile devices around medical equipment. This research explored the engagement of junior doctors (JDs) with CDS and the perceptions of patients about their use. There were three objectives for this research: (1) to measure the actual usage of CDS tools on mobile devices (mCDS) by JDs, (2) to explore the perceptions of JDs about the drivers and barriers to using mCDS, and (3) to explore the perceptions of patients about the use of mCDS. This study used a mixed-methods approach to study the engagement of JDs with CDS accessed through mobile devices. Usage data were collected on the number of interactions by JDs with mCDS. The perceived drivers and barriers for JDs to using CDS were then explored by interviews. Finally, these findings were contrasted with the perception of patients about the use of mCDS by JDs. Nine of the 16 JDs made a total of 142 recorded interactions with the mCDS over a 4-month period. Only 27 of the 114 interactions (24%) that could be categorized as on-shift or off-shift occurred on-shift. Eight individual, institutional, and cultural barriers to engagement emerged from interviews with the user group. In contrast to reported cautions and concerns about the impact of clinicians' use of mobile phone on patient health and safety, patients had positive perceptions about the use of mCDS. Patients reported positive perceptions toward mCDS. The usage of mCDS to support clinical decision making was considered to be positive as part of everyday clinical practice. The degree of engagement was found to be limited due to a number of individual, institutional, and cultural barriers. The majority of mCDS engagement occurred outside of the workplace. Further research is required to verify these findings and assess their implications for future policy and practice.

Reaction monitoring using hyperpolarized NMR with scaling of heteronuclear couplings by optimal tracking.

PubMed

Zhang, Guannan; Schilling, Franz; Glaser, Steffen J; Hilty, Christian

2016-11-01

Off-resonance decoupling using the method of Scaling of Heteronuclear Couplings by Optimal Tracking (SHOT) enables determination of heteronuclear correlations of chemical shifts in single scan NMR spectra. Through modulation of J-coupling evolution by shaped radio frequency pulses, off resonance decoupling using SHOT pulses causes a user-defined dependence of the observed J-splitting, such as the splitting of 13 C peaks, on the chemical shift offset of coupled nuclei, such as 1 H. Because a decoupling experiment requires only a single scan, this method is suitable for characterizing on-going chemical reactions using hyperpolarization by dissolution dynamic nuclear polarization (D-DNP). We demonstrate the calculation of [ 13 C, 1 H] chemical shift correlations of the carbanionic active sites from hyperpolarized styrene polymerized using sodium naphthalene as an initiator. While off resonance decoupling by SHOT pulses does not enhance the resolution in the same way as a 2D NMR spectrum would, the ability to obtain the correlations in single scans makes this method ideal for determination of chemical shifts in on-going reactions on the second time scale. In addition, we present a novel SHOT pulse that allows to scale J-splittings 50% larger than the respective J-coupling constant. This feature can be used to enhance the resolution of the indirectly detected chemical shift and reduce peak overlap, as demonstrated in a model reaction between p-anisaldehyde and isobutylamine. For both pulses, the accuracy is evaluated under changing signal-to-noise ratios (SNR) of the peaks from reactants and reaction products, with an overall standard deviation of chemical shift differences compared to reference spectra of 0.02ppm when measured on a 400MHz NMR spectrometer. Notably, the appearance of decoupling side-bands, which scale with peak intensity, appears to be of secondary importance. Copyright © 2016 Elsevier Inc. All rights reserved.

Analysis of the 3D structure og agglutinated erythrocyte using CellScan and confocal microscopy: characterization by FLIM-FRET

NASA Astrophysics Data System (ADS)

Riquelme, Bibiana D.; Dumas, Dominique; Valverde de Rasia, Juana; Rasia, Rodolfo J.; Stoltz, Jean Francois

2003-10-01

We report the adhesion of human erythrocyte membranes mediated by monoclonal antibodies anti-glycophorin. The distribution of the linked antibodies on membrane was identified with selective fluorescence labels. To analyze the antibody distribution on interfacial region between two cells agglutinated and on its surface, three types of fluorescence marked strategy were evaluated. The 3D images were obtained in a CellScan and Confocal Laser Scanning Microscopy CLSM. We considered the FRET signal to characterize the agglutination of Red Blood Cells (RBC) by specific monoclonal antibodies (anti-glycophorin A or B). The fluorescence labeling demonstrated that distribution of antibody on erythrocyte membranes is not homogeneous. The fluorescence intensity on contact region in the agglutinated is bigger than the intensity on exterior surface. Tentatively, we interpreted these intensity differences in terms of the mobility of antibody linked to the glycocalix on cell surface. Such mobility has a large consequence in the morphology of cellular agglutinated.

Development, Calibration and Evaluation of a Portable and Direct Georeferenced Laser Scanning System for Kinematic 3D Mapping

NASA Astrophysics Data System (ADS)

Heinz, Erik; Eling, Christian; Wieland, Markus; Klingbeil, Lasse; Kuhlmann, Heiner

2015-12-01

In recent years, kinematic laser scanning has become increasingly popular because it offers many benefits compared to static laser scanning. The advantages include both saving of time in the georeferencing and a more favorable scanning geometry. Often mobile laser scanning systems are installed on wheeled platforms, which may not reach all parts of the object. Hence, there is an interest in the development of portable systems, which remain operational even in inaccessible areas. The development of such a portable laser scanning system is presented in this paper. It consists of a lightweight direct georeferencing unit for the position and attitude determination and a small low-cost 2D laser scanner. This setup provides advantages over existing portable systems that employ heavy and expensive 3D laser scanners in a profiling mode. A special emphasis is placed on the system calibration, i. e. the determination of the transformation between the coordinate frames of the direct georeferencing unit and the 2D laser scanner. To this end, a calibration field is used, which consists of differently orientated georeferenced planar surfaces, leading to estimates for the lever arms and boresight angles with an accuracy of mm and one-tenth of a degree. Finally, point clouds of the mobile laser scanning system are compared with georeferenced point clouds of a high-precision 3D laser scanner. Accordingly, the accuracy of the system is in the order of cm to dm. This is in good agreement with the expected accuracy, which has been derived from the error propagation of previously estimated variance components.

A microfluidics-based mobility shift assay to identify new inhibitors of β-secretase for Alzheimer's disease.

PubMed

Liu, Rongfeng; Liu, Yu-Chih; Meng, Junwei; Zhu, Haiyan; Zhang, Xuehong

2017-11-01

The β-secretase (BACE1) initiates the generation of toxic amyloid-β peptide (Aβ) from amyloid-β precursor protein (APP), which was widely considered to play a key role in the pathogenesis of Alzheimer's disease (AD). Here, a novel microfluidics-based mobility shift assay (MMSA) was developed, validated, and applied for the screening of BACE1 inhibitors for AD. First, the BACE1 activity assay was established with a new fluorescent peptide substrate (FAM-EVNLDAEF) derived from the Swedish mutant APP, and high-quality ratiometric data were generated in both endpoint and kinetic modes by electrophoretic separation of peptide substrate from the BACE1 cleaved product (FAM-EVNL) before fluorescence quantification. To validate the assay, the inhibition and kinetic parameter values of two known inhibitors (AZD3839 and AZD3293) were evaluated, and the results were in good agreement with those reported by other methods. Finally, the assay was applied to screen for new inhibitors from a 900-compound library in a 384-well format, and one novel hit (IC 50 = 26.5 ± 1.5 μM) was identified. Compared with the common fluorescence-based assays, the primary advantage of the direct MMSA was to discover novel BACE1 inhibitors with lower auto-fluorescence interference, and its superb capability for kinetic study. Graphical abstract Microfluidics-based mobility shift assay for BACE1.

Modulation and coding for fast fading mobile satellite communication channels

NASA Technical Reports Server (NTRS)

Mclane, P. J.; Wittke, P. H.; Smith, W. S.; Lee, A.; Ho, P. K. M.; Loo, C.

1988-01-01

The performance of Gaussian baseband filtered minimum shift keying (GMSK) using differential detection in fast Rician fading, with a novel treatment of the inherent intersymbol interference (ISI) leading to an exact solution is discussed. Trellis-coded differentially coded phase shift keying (DPSK) with a convolutional interleaver is considered. The channel is the Rician Channel with the line-of-sight component subject to a lognormal transformation.

Method for imaging liquid and dielectric materials with scanning polarization force microscopy

DOEpatents

Hu, Jun; Ogletree, D. Frank; Salmeron, Miguel; Xiao, Xudong

1999-01-01

The invention images dielectric polarization forces on surfaces induced by a charged scanning force microscope (SFM) probe tip. On insulators, the major contribution to the surface polarizability at low frequencies is from surface ions. The mobility of these ions depends strongly on the humidity. Using the inventive SFM, liquid films, droplets, and other weakly adsorbed materials have been imaged.

Apparatus for imaging liquid and dielectric materials with scanning polarization force microscopy

DOEpatents

Hu, Jun; Ogletree, D. Frank; Salmeron, Miguel; Xiao, Xudong

1998-01-01

The invention images dielectric polarization forces on surfaces induced by a charged scanning force microscope (SFM) probe tip. On insulators, the major contribution to the surface polarizability at low frequencies is from surface ions. The mobility of these ions depends strongly on the humidity. Using the inventive SFM, liquid films, droplets, and other weakly adsorbed materials have been imaged.

Soft x-ray spectromicroscopy using compact scanning transmission x-ray microscope at the photon factory

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

Takeichi, Yasuo, E-mail: yasuo.takeichi@kek.jp; Inami, Nobuhito; Ono, Kanta

We report the stability and recent performances of a new type of scanning transmission X-ray microscopy. The optics and compact design of the microscope realized mobility and robust performance. Detailed consideration to the vibration control will be described. The insertion device upgraded to elliptical polarization undulator enabled linear dichroism and circular dichroism experiments.

Transformation optics with windows

NASA Astrophysics Data System (ADS)

Oxburgh, Stephen; White, Chris D.; Antoniou, Georgios; Orife, Ejovbokoghene; Courtial, Johannes

2014-09-01

Identity certification in the cyberworld has always been troublesome if critical information and financial transaction must be processed. Biometric identification is the most effective measure to circumvent the identity issues in mobile devices. Due to bulky and pricy optical design, conventional optical fingerprint readers have been discarded for mobile applications. In this paper, a digital variable-focus liquid lens was adopted for capture of a floating finger via fast focusplane scanning. Only putting a finger in front of a camera could fulfill the fingerprint ID process. This prototyped fingerprint reader scans multiple focal planes from 30 mm to 15 mm in 0.2 second. Through multiple images at various focuses, one of the images is chosen for extraction of fingerprint minutiae used for identity certification. In the optical design, a digital liquid lens atop a webcam with a fixed-focus lens module is to fast-scan a floating finger at preset focus planes. The distance, rolling angle and pitching angle of the finger are stored for crucial parameters during the match process of fingerprint minutiae. This innovative compact touchless fingerprint reader could be packed into a minute size of 9.8*9.8*5 (mm) after the optical design and multiple focus-plane scan function are optimized.

Morphology and Mobility of the Reconstructed Basilar Joint of the Pollicized Index Finger.

PubMed

Strugarek-Lecoanet, Clotilde; Chevrollier, Jérémie; Pauchard, Nicolas; Blum, Alain; Dap, François; Dautel, Gilles

2016-09-01

To evaluate outcome and function of the reconstructed basilar thumb joint after index finger pollicization in patients presenting congenital thumb deficiency. Plain radiographs and 4-dimensional dynamic volume computed tomography scan were used to evaluate the outcome of 23 pollicizations performed on 14 children between 1996 and 2009. The mean follow-up was 8 years. Patients performed continuous movements of thumb opposition during the imaging studies. Four-dimensional scan images made it possible to visualize mobility within the reconstructed joint. In 14 cases, union occurred in the metacarpal head/metacarpal base interface. In the 9 other cases, there was a nonunion at this interface. The reconstructed joint was mobile in 20 cases, including 3 in which there was also mobility at the site of the nonunion. In 3 cases in our series, mobility was present only at the site of the nonunion, between the base and the head of the second metacarpal. Remodeling and flattening out of the metacarpal head occurred in 16 of 23 cases. The transposed metacarpal head remained spherical in 7 cases. The reconstructed joint adapts, both morphologically and functionally, allowing movement on all 3 spatial planes. Existing mechanical constraints on the reconstructed joint may explain its remodeled appearance. Therapeutic IV. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

X-ray and neutron interrogation of air cargo for mobile applications

NASA Astrophysics Data System (ADS)

Van Liew, Seth

2015-06-01

A system for scanning break-bulk cargo for mobile applications is presented. This combines a 140 kV multi-view, multi-energy X-ray system with 2.5 MeV neutrons. The system uses dual energy X-ray radiography with neutron radiography. The X-ray and neutron systems were designed to be collocated in a mobile environment. Various materials were interrogated with the intent of distinguishing threat materials such as explosives from similar benign materials. In particular, the identification of threats and bengins with nearly identical effective atomic numbers has been demonstrated.

[Mobile CT: technical aspects of prehospital stroke imaging before intravenous thrombolysis].

PubMed

Gierhake, D; Weber, J E; Villringer, K; Ebinger, M; Audebert, H J; Fiebach, J B

2013-01-01

To reduce the time from symptom onset to treatment with tissue plasminogen activator (tPA) in ischemic stroke, an ambulance was equipped with a CT scanner. We analyzed process and image quality of CT scanning during the pilot study regarding image quality and safety issues. The pilot study of a stroke emergency mobile unit (STEMO) ran over a period of 12 weeks on 5 weekdays from 7a.m. to 6:30 p.m. A teleradiological service for the justifying indication and reporting was established. The radiographer was responsible for the performance of the CT scan on the ambulance. 64 cranial CT scans and 1 intracranial CT angiography were performed. We compared times from ambulance alarm to treatment decision (time of last brain scan) with a cohort of 50 consecutive tPA treatments before implementation of STEMO. 62 (95%) of the 65 scans performed had sufficient quality for reading. Technical quality was not optimal in 45 cases (69%) mainly caused by suboptimal positioning of patient or eye lens protection. Motion artefacts were observed in 8 exams (12%). No safety issues occurred for team or patients. 23 patients were treated with thrombolysis. Time from alarm to last CT scan was 18 minutes shorter than in the tPA cohort before STEMO implementation. A teleradiological support for primary stroke imaging by CT on-site is feasible, quality-wise of diagnostic value and has not raised safety issues. © Georg Thieme Verlag KG Stuttgart · New York.

Ultrasonic inspection and deployment apparatus

DOEpatents

Michaels, Jennifer E.; Michaels, Thomas E.; Mech, Jr., Stephen J.

1984-01-01

An ultrasonic inspection apparatus for the inspection of metal structures, especially installed pipes. The apparatus combines a specimen inspection element, an acoustical velocity sensing element, and a surface profiling element, all in one scanning head. A scanning head bellows contains a volume of oil above the pipe surface, serving as acoustical couplant between the scanning head and the pipe. The scanning head is mounted on a scanning truck which is mobile around a circular track surrounding the pipe. The scanning truck has sufficient motors, gears, and position encoders to allow the scanning head six degrees of motion freedom. A computer system continually monitors acoustical velocity, and uses that parameter to process surface profiling and inspection data. The profiling data is used to automatically control scanning head position and alignment and to define a coordinate system used to identify and interpret inspection data. The apparatus is suitable for highly automated, remote application in hostile environments, particularly high temperature and radiation areas.

NARSTO EPA SS LOS ANGELES SMPS DATA

Atmospheric Science Data Center

2018-04-09

... Ground Station Instrument:  SMPS - Scanning Mobility Particle Sizer Location:  Los Angeles, ... Get Google Earth Related Data:  Environmental Protection Agency Supersites Los Angeles, California ...

The mobile hospital technology industry: focus on the computerized tomography scanner.

PubMed

Hartley, D; Moscovice, I

1996-01-01

This study of firms offering mobile hospital technology to rural hospitals in eight northwestern states found that several permanently parked computerized tomography (CT) units were found where mobile routes had atrophied due to the purchase of fixed units by former mobile CT hospital clients. Based on a criterion of 140 scans per month per unit as a threshold of profitable production, units owned by larger firms (those that operate five or more units) were more likely to be profitable than units owned by smaller firms (71% versus 20%, P = 0.03). A substantial number of rural hospitals lose money on mobile CT due to low Medicare reimbursement. In some areas, mobile hospital technology is a highly competitive industry. Evidence was found that several firms compete in some geographic areas and that some firms have lost hospital clients to competing vendors.

A method for modelling peak signal statistics on a mobile satellite transponder

NASA Technical Reports Server (NTRS)

Bilodeau, Andre; Lecours, Michel; Pelletier, Marcel; Delisle, Gilles Y.

1990-01-01

A simulation method is proposed. The simulation was developed to model the peak duration and energy content of signal peaks in a mobile communication satellite operating in a Frequency Division Multiple Access (FDMA) mode and presents an estimate of those power peaks for a system where the channels are modeled as band limited Gaussian noise, which is taken as a reasonable representation for Amplitude Commanded Single Sideband (ACSSB), Minimum Shift Keying (MSK), or Phase Shift Keying (PSK) modulated signals. The simulation results show that, under this hypothesis, the level of the signal power peaks for 10 percent, 1 percent, and 0.1 percent of the time are well described by a Rayleigh law and that their duration is extremely short and inversely proportional to the total FDM system bandwidth.

Accuracy assessment of a mobile terrestrial lidar survey at Padre Island National Seashore

USGS Publications Warehouse

Lim, Samsung; Thatcher, Cindy A.; Brock, John C.; Kimbrow, Dustin R.; Danielson, Jeffrey J.; Reynolds, B.J.

2013-01-01

The higher point density and mobility of terrestrial laser scanning (light detection and ranging (lidar)) is desired when extremely detailed elevation data are needed for mapping vertically orientated complex features such as levees, dunes, and cliffs, or when highly accurate data are needed for monitoring geomorphic changes. Mobile terrestrial lidar scanners have the capability for rapid data collection on a larger spatial scale compared with tripod-based terrestrial lidar, but few studies have examined the accuracy of this relatively new mapping technology. For this reason, we conducted a field test at Padre Island National Seashore of a mobile lidar scanner mounted on a sport utility vehicle and integrated with a position and orientation system. The purpose of the study was to assess the vertical and horizontal accuracy of data collected by the mobile terrestrial lidar system, which is georeferenced to the Universal Transverse Mercator coordinate system and the North American Vertical Datum of 1988. To accomplish the study objectives, independent elevation data were collected by conducting a high-accuracy global positioning system survey to establish the coordinates and elevations of 12 targets spaced throughout the 12 km transect. These independent ground control data were compared to the lidar scanner-derived elevations to quantify the accuracy of the mobile lidar system. The performance of the mobile lidar system was also tested at various vehicle speeds and scan density settings (e.g. field of view and linear point spacing) to estimate the optimal parameters for desired point density. After adjustment of the lever arm parameters, the final point cloud accuracy was 0.060 m (east), 0.095 m (north), and 0.053 m (height). The very high density of the resulting point cloud was sufficient to map fine-scale topographic features, such as the complex shape of the sand dunes.

Role of IKK-alpha in the EGFR Signaling Regulation

DTIC Science & Technology

2014-09-01

Rho family GTPase (VAV2), and Phospholipase C (PLC) (4). These signaling activities regulate cell proliferation, mobility , and differentiation in...correlation coefficient r=0.63, pɘ.05) was found, suggesting that high IKK promotes EGFR phosphorylation in breast cancer cells (Fig. 3G ...phosphorylation (Figure 2E). Since protein phosphorylation sometimes results in a mobility shift in SDS-PAGE, we used a phospho-tag to capture phospho

Federated Ground Station Network Model and Interface Specification

DTIC Science & Technology

2014-12-01

interface definition language JSON JavaScript Object Notation LEO low Earth orbit LNA low-noise amplifier MC3 Mobile CubeSat Command and Control...Naval Research Laboratory OQPSK offset quadrature phase-shift keying xviii P2P peer-to-peer PKI public key infrastructure REST Representational...enhanced our work being performed on the Mobile CubeSat Command and Control (MC3) ground station network. You also provided crucial guidance from

"MXing it up": how African adolescents may affect social change through mobile phone use.

PubMed

Napolitano, Christopher M

2010-01-01

This chapter outlines mobile phone use among African (particularly South African) adolescents. With an estimated 350 million active mobile phone subscriptions, improving network infrastructure, low-cost Internet-ready handsets, innovative programs and applications, mobiles in Africa, and their increasingly younger, increasingly poorer, and increasingly savvy users have the potential to act as conduits for local and regional socially just change. This broad-based connectedness not only provides access to information, but also, and crucially, connects individuals and their social, intellectual, and financial capital. It may represent a powerful, transformative shift in a region where access to similar technologies was historically limited to a privileged few. In order to best leverage these developments and opportunities to promote socially just change, I argue that future mobile-based programs or initiatives in the region should be based in both contemporary developmental systems theory as well as current, popular mobile applications and services.

State of the cart.

PubMed

Bernstein, C; Weiss, S; Lorenzini, B

1994-03-15

Food on wheels: it's here, there and everywhere. But while some operations rev up cart expansion plans, others have shifted into low gear. Here's an update on that '90s phenomenon: mobile merchandising.

Photographic measurement of head and cervical posture when viewing mobile phone: a pilot study.

PubMed

Guan, Xiaofei; Fan, Guoxin; Wu, Xinbo; Zeng, Ying; Su, Hang; Gu, Guangfei; Zhou, Qi; Gu, Xin; Zhang, Hailong; He, Shisheng

2015-12-01

With the dramatic growth of mobile phone usage, concerns have been raised with regard to the adverse health effects of mobile phone on spinal posture. The aim of this study was to determine the head and cervical postures by photogrammetry when viewing the mobile phone screen, compared with those in neutral standing posture. A total of 186 subjects (81 females and 105 males) aged from 17 to 31 years old participated in this study. Subjects were instructed to stand neutrally and using mobile phone as in daily life. Using a photographic method, the sagittal head and cervical postures were assessed by head tilt angle, neck tilt angle, forward head shift and gaze angle. The photographic method showed a high intra-rater and inter-rater reliability in measuring the sagittal posture of cervical spine and gaze angle (ICCs ranged from 0.80 to 0.99). When looking at mobile phone, the head tilt angle significantly increased (from 74.55° to 95.22°, p = 0.000) and the neck angle decreased (from 54.68° to 38.77°, p = 0.000). The forward head posture was also confirmed by the significantly increased head shift (from 10.90 to 13.85 cm, p = 0.000). The posture assumed in mobile phone use was significantly correlated with neutral posture (p < 0.05). Males displayed a more forward head posture than females (p < 0.05). The head tilt angle was positively correlated with the gaze angle (r = 0.616, p = 0.000), while the neck tilt angle was negatively correlated with the gaze angle (r = -0.628, p = 0.000). Photogrammetry is a reliable, quantitative method to evaluate the head and cervical posture during mobile phone use. Compared to neutral standing, subjects display a more forward head posture when viewing the mobile phone screen, which is correlated with neutral posture, gaze angle and gender. Future studies will be needed to investigate a dose-response relationship between mobile phone use and assumed posture.

Rapid measurement of sub-micrometer aerosol size distribution using a fast integrated mobility spectrometer

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

Wang, Yang; Pinterich, Tamara; Wang, Jian

We present rapid measurement of submicron particle size distributions enables the characterization of aerosols with fast changing properties, and is often necessary for measurements onboard mobile platforms (e.g., research aircraft). Aerosol mobility size distribution is commonly measured by a scanning mobility particle sizer (SMPS), which relies on voltage scanning or stepping to classify particles of different sizes, and may take up to several minutes to obtain a complete size spectrum of aerosol particles. The recently developed fast integrated mobility spectrometer (FIMS) with enhanced dynamic size range classifies and detects particles from 10 to ~600 nm simultaneously, allowing submicron aerosol mobilitymore » size distributions to be captured at a time resolution of 1 second. In this study, we present a detailed data inversion routine for deriving aerosol size distribution from FIMS measurements. The inversion routine takes into consideration the FIMS transfer function, particle penetration efficiency in the FIMS, and multiple charging of aerosols. The accuracy of the FIMS measurement is demonstrated by comparing parallel FIMS and SMPS measurements of stable aerosols with a wide range of size spectrum shapes, including ambient aerosols and aerosols classified by a differential mobility analyzer (DMA). The FIMS and SMPS-derived size distributions show excellent agreements for all aerosols tested. In addition, total number concentrations of ambient aerosols were integrated from 1 Hz FIMS size distributions, and compared with those directly measured by a condensation particle counter (CPC) operated in parallel. Finally, the integrated and measured total particle concentrations agree well within 5%.« less

Rapid measurement of sub-micrometer aerosol size distribution using a fast integrated mobility spectrometer

DOE PAGES

Wang, Yang; Pinterich, Tamara; Wang, Jian

2018-03-30

We present rapid measurement of submicron particle size distributions enables the characterization of aerosols with fast changing properties, and is often necessary for measurements onboard mobile platforms (e.g., research aircraft). Aerosol mobility size distribution is commonly measured by a scanning mobility particle sizer (SMPS), which relies on voltage scanning or stepping to classify particles of different sizes, and may take up to several minutes to obtain a complete size spectrum of aerosol particles. The recently developed fast integrated mobility spectrometer (FIMS) with enhanced dynamic size range classifies and detects particles from 10 to ~600 nm simultaneously, allowing submicron aerosol mobilitymore » size distributions to be captured at a time resolution of 1 second. In this study, we present a detailed data inversion routine for deriving aerosol size distribution from FIMS measurements. The inversion routine takes into consideration the FIMS transfer function, particle penetration efficiency in the FIMS, and multiple charging of aerosols. The accuracy of the FIMS measurement is demonstrated by comparing parallel FIMS and SMPS measurements of stable aerosols with a wide range of size spectrum shapes, including ambient aerosols and aerosols classified by a differential mobility analyzer (DMA). The FIMS and SMPS-derived size distributions show excellent agreements for all aerosols tested. In addition, total number concentrations of ambient aerosols were integrated from 1 Hz FIMS size distributions, and compared with those directly measured by a condensation particle counter (CPC) operated in parallel. Finally, the integrated and measured total particle concentrations agree well within 5%.« less

Structured Light Based 3d Scanning for Specular Surface by the Combination of Gray Code and Phase Shifting

NASA Astrophysics Data System (ADS)

Zhang, Yujia; Yilmaz, Alper

2016-06-01

Surface reconstruction using coded structured light is considered one of the most reliable techniques for high-quality 3D scanning. With a calibrated projector-camera stereo system, a light pattern is projected onto the scene and imaged by the camera. Correspondences between projected and recovered patterns are computed in the decoding process, which is used to generate 3D point cloud of the surface. However, the indirect illumination effects on the surface, such as subsurface scattering and interreflections, will raise the difficulties in reconstruction. In this paper, we apply maximum min-SW gray code to reduce the indirect illumination effects of the specular surface. We also analysis the errors when comparing the maximum min-SW gray code and the conventional gray code, which justifies that the maximum min-SW gray code has significant superiority to reduce the indirect illumination effects. To achieve sub-pixel accuracy, we project high frequency sinusoidal patterns onto the scene simultaneously. But for specular surface, the high frequency patterns are susceptible to decoding errors. Incorrect decoding of high frequency patterns will result in a loss of depth resolution. Our method to resolve this problem is combining the low frequency maximum min-SW gray code and the high frequency phase shifting code, which achieves dense 3D reconstruction for specular surface. Our contributions include: (i) A complete setup of the structured light based 3D scanning system; (ii) A novel combination technique of the maximum min-SW gray code and phase shifting code. First, phase shifting decoding with sub-pixel accuracy. Then, the maximum min-SW gray code is used to resolve the ambiguity resolution. According to the experimental results and data analysis, our structured light based 3D scanning system enables high quality dense reconstruction of scenes with a small number of images. Qualitative and quantitative comparisons are performed to extract the advantages of our new combined coding method.

Social Properties of Mobile Video

NASA Astrophysics Data System (ADS)

Mitchell, April Slayden; O'Hara, Kenton; Vorbau, Alex

Mobile video is now an everyday possibility with a wide array of commercially available devices, services, and content. These new technologies have created dramatic shifts in the way video-based media can be produced, consumed, and delivered by people beyond the familiar behaviors associated with fixed TV and video technologies. Such technology revolutions change the way users behave and change their expectations in regards to their mobile video experiences. Building upon earlier studies of mobile video, this paper reports on a study using diary techniques and ethnographic interviews to better understand how people are using commercially available mobile video technologies in their everyday lives. Drawing on reported episodes of mobile video behavior, the study identifies the social motivations and values underpinning these behaviors that help characterize mobile video consumption beyond the simplistic notion of viewing video only to kill time. This paper also discusses the significance of user-generated content and the usage of video in social communities through the description of two mobile video technology services that allow users to create and share content. Implications for adoption and design of mobile video technologies and services are discussed as well.

Using Eye Tracking to Explore Consumers' Visual Behavior According to Their Shopping Motivation in Mobile Environments.

PubMed

Hwang, Yoon Min; Lee, Kun Chang

2017-07-01

Despite a strong shift to mobile shopping trends, many in-depth questions about mobile shoppers' visual behaviors in mobile shopping environments remain unaddressed. This study aims to answer two challenging research questions (RQs): (a) how much does shopping motivation like goal orientation and recreation influence mobile shoppers' visual behavior toward displays of shopping information on a mobile shopping screen and (b) how much of mobile shoppers' visual behavior influences their purchase intention for the products displayed on a mobile shopping screen? An eye-tracking approach is adopted to answer the RQs empirically. The experimental results showed that goal-oriented shoppers paid closer attention to products' information areas to meet their shopping goals. Their purchase intention was positively influenced by their visual attention to the two areas of interest such as product information and consumer opinions. In contrast, recreational shoppers tended to visually fixate on the promotion area, which positively influences their purchase intention. The results contribute to understanding mobile shoppers' visual behaviors and shopping intentions from the perspective of mindset theory.

From Multilingualism to Bilingualism: Changes in Language Use, Language Value, and Social Mobility among Engdewu Speakers in the Solomon Islands

ERIC Educational Resources Information Center

Emerine Hicks, Rachel

2017-01-01

On the island of Santa Cruz in the Solomon Islands, the Engdewu language is facing imminent language shift because of the increasing use of the lingua franca Solomon Islands Pijin in the community. In this article, I argue that this language shift is occurring because of changes to the social structure in Baemawz, one of the villages where Engdewu…

Isolation of a 5-Kilodalton Actin-Sequestering Peptide from Human Blood Platelets

NASA Astrophysics Data System (ADS)

Safer, Daniel; Golla, Rajasree; Nachmias, Vivianne T.

1990-04-01

Resting human platelets contain ≈0.3 mM unpolymerized actin. When freshly drawn and washed platelets are treated with saponin, 85-90% of the unpolymerized actin diffuses out. Analysis by polyacrylamide gel electrophoresis under nondenaturing conditions shows that the bulk of this unpolymerized actin migrates with a higher mobility than does pure G-actin, profilactin, or actin-gelsolin complex. When muscle G-actin is added to fresh or boiled saponin extract, the added muscle actin is shifted to the high-mobility form. The saponin extract contains an acidic peptide having a molecular mass in the range of 5 kDa, which has been purified to homogeneity by reverse-phase HPLC. This peptide also shifts muscle actin to the high-mobility form. Addition of either boiled saponin extract or the purified peptide to muscle G-actin also strongly and stoichiometrically inhibits salt-induced polymerization, as assayed by falling-ball viscometry and by sedimentation. We conclude that this peptide binds to the bulk of the unpolymerized actin in platelets and prevents it from polymerizing.

Dose related shifts in the developmental progress of chick embryos exposed to mobile phone induced electromagnetic fields.

PubMed

Zareen, Nusrat; Khan, Muhammad Yunus; Minhas, Liaqat Ali

2009-01-01

The possible adverse effects of Electromagnetic Fields (EMFs) emitted from mobile phones present a major public concern today. Some studies indicate EMFs effects on genes, free radical production, immunological and carcinogenic effects. On the other hand there are studies which do not support the hypothesis of any biological impacts of EMFs. This study was designed to observe the effects of mobile phone induced EMFs on survival and general growth and development of chick embryo, investigating dose-response relationship if any. This was an experimental study in which developing chick embryos were exposed to different doses of mobile phone induced EMFs. For this purpose a mobile phone was placed in the incubator in the centre of fertilised eggs in silent ringing mode and was 'rung' upon from any other line or cell phone. After incubation for 10 or 15 days the eggs were opened and the developmental mile-stones of the surviving embryos were compared with the non exposed subgroup. EMFs exposure significantly decreased the survivability of the chick embryos. The lower doses of EMFs caused growth retardation. However, this effect of growth retardation reallocated to partial growth enhancement on increasing the dose of EMFs and shifted over to definite growth enhancement on further raising the dose. There is an adverse effect of EMFs exposure on embryo survivability. Chick embryos developmental process is influenced by EMFs. However, these effects are variable depending upon the dose of EMFs exposure.

Method for imaging liquid and dielectric materials with scanning polarization force microscopy

DOEpatents

Hu, J.; Ogletree, D.F.; Salmeron, M.; Xiao, X.

1999-03-09

The invention images dielectric polarization forces on surfaces induced by a charged scanning force microscope (SFM) probe tip. On insulators, the major contribution to the surface polarizability at low frequencies is from surface ions. The mobility of these ions depends strongly on the humidity. Using the inventive SFM, liquid films, droplets, and other weakly adsorbed materials have been imaged. 9 figs.

Apparatus for imaging liquid and dielectric materials with scanning polarization force microscopy

DOEpatents

Hu, J.; Ogletree, D.F.; Salmeron, M.; Xiao, X.

1998-04-28

The invention images dielectric polarization forces on surfaces induced by a charged scanning force microscope (SFM) probe tip. On insulators, the major contribution to the surface polarizability at low frequencies is from surface ions. The mobility of these ions depends strongly on the humidity. Using the inventive SFM, liquid films, droplets, and other weakly adsorbed materials have been imaged. 9 figs.

Improving Inpatient Surveys: Web-Based Computer Adaptive Testing Accessed via Mobile Phone QR Codes

PubMed Central

2016-01-01

Background The National Health Service (NHS) 70-item inpatient questionnaire surveys inpatients on their perceptions of their hospitalization experience. However, it imposes more burden on the patient than other similar surveys. The literature shows that computerized adaptive testing (CAT) based on item response theory can help shorten the item length of a questionnaire without compromising its precision. Objective Our aim was to investigate whether CAT can be (1) efficient with item reduction and (2) used with quick response (QR) codes scanned by mobile phones. Methods After downloading the 2008 inpatient survey data from the Picker Institute Europe website and analyzing the difficulties of this 70-item questionnaire, we used an author-made Excel program using the Rasch partial credit model to simulate 1000 patients’ true scores followed by a standard normal distribution. The CAT was compared to two other scenarios of answering all items (AAI) and the randomized selection method (RSM), as we investigated item length (efficiency) and measurement accuracy. The author-made Web-based CAT program for gathering patient feedback was effectively accessed from mobile phones by scanning the QR code. Results We found that the CAT can be more efficient for patients answering questions (ie, fewer items to respond to) than either AAI or RSM without compromising its measurement accuracy. A Web-based CAT inpatient survey accessed by scanning a QR code on a mobile phone was viable for gathering inpatient satisfaction responses. Conclusions With advances in technology, patients can now be offered alternatives for providing feedback about hospitalization satisfaction. This Web-based CAT is a possible option in health care settings for reducing the number of survey items, as well as offering an innovative QR code access. PMID:26935793

Improving Inpatient Surveys: Web-Based Computer Adaptive Testing Accessed via Mobile Phone QR Codes.

PubMed

Chien, Tsair-Wei; Lin, Weir-Sen

2016-03-02

The National Health Service (NHS) 70-item inpatient questionnaire surveys inpatients on their perceptions of their hospitalization experience. However, it imposes more burden on the patient than other similar surveys. The literature shows that computerized adaptive testing (CAT) based on item response theory can help shorten the item length of a questionnaire without compromising its precision. Our aim was to investigate whether CAT can be (1) efficient with item reduction and (2) used with quick response (QR) codes scanned by mobile phones. After downloading the 2008 inpatient survey data from the Picker Institute Europe website and analyzing the difficulties of this 70-item questionnaire, we used an author-made Excel program using the Rasch partial credit model to simulate 1000 patients' true scores followed by a standard normal distribution. The CAT was compared to two other scenarios of answering all items (AAI) and the randomized selection method (RSM), as we investigated item length (efficiency) and measurement accuracy. The author-made Web-based CAT program for gathering patient feedback was effectively accessed from mobile phones by scanning the QR code. We found that the CAT can be more efficient for patients answering questions (ie, fewer items to respond to) than either AAI or RSM without compromising its measurement accuracy. A Web-based CAT inpatient survey accessed by scanning a QR code on a mobile phone was viable for gathering inpatient satisfaction responses. With advances in technology, patients can now be offered alternatives for providing feedback about hospitalization satisfaction. This Web-based CAT is a possible option in health care settings for reducing the number of survey items, as well as offering an innovative QR code access.

Mobile Laser Scanning Systems for Measuring the Clearance Gauge of Railways: State of Play, Testing and Outlook

PubMed Central

Mikrut, Sławomir; Kohut, Piotr; Pyka, Krystian; Tokarczyk, Regina; Barszcz, Tomasz; Uhl, Tadeusz

2016-01-01

The paper contains a survey of mobile scanning systems for measuring the railway clearance gauge. The research was completed as part of the project carried out for the PKP (PKP Polish Railway Lines S.A., Warsaw, Poland) in 2011–2013. The authors conducted experiments, including a search for the latest solutions relating to mobile measurement systems that meet the basic requirement. At the very least, these solutions needed to be accurate and have the ability for quick retrieval of data. In the paper, specifications and the characteristics of the component devices of the scanning systems are described. Based on experiments, the authors did some examination of the selected mobile systems to be applied for measuring the clearance gauge. The Riegl (VMX-250) and Z+F (Zoller + Fröhlich) Solution were tested. Additional test measurements were carried out within a 30-kilometer section of the Warsaw-Kraków route. These measurements were designed so as to provide various elements of the railway infrastructure, the track geometry and the installed geodetic control network. This ultimately made it possible to reduce the time for the preparation of geodetic reference measurements for the testing of the accuracy of the selected systems. Reference measurements included the use of the polar method to select profiles perpendicular to the axis of the track. In addition, the coordinates selected were well defined as measuring points of the objects of the infrastructure of the clearance gauge. All of the tested systems meet the accuracy requirements initially established (within the range of 2 cm as required by the PKP). The tested systems have shown their advantages and disadvantages. PMID:27187400

The Effects of Compensatory Scanning Training on Mobility in Patients with Homonymous Visual Field Defects: Further Support, Predictive Variables and Follow-Up

PubMed Central

Melis-Dankers, Bart J. M.; Brouwer, Wiebo H.; Tucha, Oliver; Heutink, Joost

2016-01-01

Introduction People with homonymous visual field defects (HVFD) often report difficulty detecting obstacles in the periphery on their blind side in time when moving around. Recently, a randomized controlled trial showed that the InSight-Hemianopia Compensatory Scanning Training (IH-CST) specifically improved detection of peripheral stimuli and avoiding obstacles when moving around, especially in dual task situations. Method The within-group training effects of the previously reported IH-CST are examined in an extended patient group. Performance of patients with HVFD on a pre-assessment, post-assessment and follow-up assessment and performance of a healthy control group are compared. Furthermore, it is examined whether training effects can be predicted by demographic characteristics, variables related to the visual disorder, and neuropsychological test results. Results Performance on both subjective and objective measures of mobility-related scanning was improved after training, while no evidence was found for improvement in visual functions (including visual fields), reading, visual search and dot counting. Self-reported improvement did not correlate with improvement in objective mobility performance. According to the participants, the positive effects were still present six to ten months after training. No demographic characteristics, variables related to the visual disorder, and neuropsychological test results were found to predict the size of training effect, although some inconclusive evidence was found for more improvement in patients with left-sided HVFD than in patients with right-sided HFVD. Conclusion Further support was found for a positive effect of IH-CST on detection of visual stimuli during mobility-related activities specifically. Based on the reports given by patients, these effects appear to be long-term effects. However, no conclusions can be drawn on the objective long-term training effects. PMID:27935973

Analysis of energy states where electrons and holes coexist in pseudomorphically strained InAs high-electron-mobility transistors

NASA Astrophysics Data System (ADS)

Nishio, Yui; Sato, Takato; Hirayama, Naomi; Iida, Tsutomu; Takanashi, Yoshifumi

2016-04-01

In strained high-electron-mobility transistors (HEMTs) with InAs as the channel, excess electrons and holes are generated in the drain region by impact ionization. In the source region, electrons are injected to recombine with accumulated holes by the Auger process. This causes the shift of the gate potential, V GS,shift, for HEMTs. For a system where electrons and holes coexist, we established a theory taking into account the nonparabolicity of the conduction band in the InAs channel. This theory enables us to rigorously determine not only the energy states and the concentration profiles for both carriers but also the V GS,shift due to an accumulation of holes. We have derived the Auger recombination theory which takes into account the Fermi-Dirac statistics and is applicable to an arbitrary shape of potential energy. The Auger recombination lifetime τA for InAs-PHEMTs was estimated as a function of the sheet hole concentration, p s, and τA was on the order of psec for p s exceeding 1012 cm-2.

Geometric validation of a mobile laser scanning system for urban applications

NASA Astrophysics Data System (ADS)

Guan, Haiyan; Li, Jonathan; Yu, Yongtao; Liu, Yan

2016-03-01

Mobile laser scanning (MLS) technologies have been actively studied and implemented over the past decade, as their application fields are rapidly expanding and extending beyond conventional topographic mapping. Trimble's MX-8, as one of the MLS systems in the current market, generates rich survey-grade laser and image data for urban surveying. The objective of this study is to evaluate whether Trimble MX-8 MLS data satisfies the accuracy requirements of urban surveying. According to the formula of geo-referencing, accuracies of navigation solution and laser scanner determines the accuracy of the collected LiDAR point clouds. Two test sites were selected to test the performance of Trimble MX-8. Those extensive tests confirm that Trimble MX-8 offers a very promising tool to survey complex urban areas.

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

Sato, Chikara, E-mail: ti-sato@aist.go.jp; Manaka, Sachie; Nakane, Daisuke

Highlights: Black-Right-Pointing-Pointer Mycoplasma mobile was observed in buffer with the Atmospheric Scanning Electron Microscope. Black-Right-Pointing-Pointer Characteristic protein localizations were visualized using immuno-labeling. Black-Right-Pointing-Pointer M. mobile attached to sialic acid on the SiN film surface within minutes. Black-Right-Pointing-Pointer Cells were observed at low concentrations. Black-Right-Pointing-Pointer ASEM should promote study and early-stage diagnosis of mycoplasma. -- Abstract: Mycoplasma is a genus of bacterial pathogen that causes disease in vertebrates. In humans, the species Mycoplasma pneumoniae causes 15% or more of community-acquired pneumonia. Because this bacterium is tiny, corresponding in size to a large virus, diagnosis using optical microscopy is not easy. Inmore » current methods, chest X-rays are usually the first action, followed by serology, PCR amplification, and/or culture, but all of these are particularly difficult at an early stage of the disease. Using Mycoplasma mobile as a model species, we directly observed mycoplasma in buffer with the newly developed Atmospheric Scanning Electron Microscope (ASEM). This microscope features an open sample dish with a pressure-resistant thin film window in its base, through which the SEM beam scans samples in solution, from below. Because of its 2-3 {mu}m-deep scanning capability, it can observe the whole internal structure of mycoplasma cells stained with metal solutions. Characteristic protein localizations were visualized using immuno-labeling. Cells were observed at low concentrations, because suspended cells concentrate in the observable zone by attaching to sialic acid on the silicon nitride (SiN) film surface within minutes. These results suggest the applicability of the ASEM for the study of mycoplasmas as well as for early-stage mycoplasma infection diagnosis.« less

LSD-induced entropic brain activity predicts subsequent personality change.

PubMed

Lebedev, A V; Kaelen, M; Lövdén, M; Nilsson, J; Feilding, A; Nutt, D J; Carhart-Harris, R L

2016-09-01

Personality is known to be relatively stable throughout adulthood. Nevertheless, it has been shown that major life events with high personal significance, including experiences engendered by psychedelic drugs, can have an enduring impact on some core facets of personality. In the present, balanced-order, placebo-controlled study, we investigated biological predictors of post-lysergic acid diethylamide (LSD) changes in personality. Nineteen healthy adults underwent resting state functional MRI scans under LSD (75µg, I.V.) and placebo (saline I.V.). The Revised NEO Personality Inventory (NEO-PI-R) was completed at screening and 2 weeks after LSD/placebo. Scanning sessions consisted of three 7.5-min eyes-closed resting-state scans, one of which involved music listening. A standardized preprocessing pipeline was used to extract measures of sample entropy, which characterizes the predictability of an fMRI time-series. Mixed-effects models were used to evaluate drug-induced shifts in brain entropy and their relationship with the observed increases in the personality trait openness at the 2-week follow-up. Overall, LSD had a pronounced global effect on brain entropy, increasing it in both sensory and hierarchically higher networks across multiple time scales. These shifts predicted enduring increases in trait openness. Moreover, the predictive power of the entropy increases was greatest for the music-listening scans and when "ego-dissolution" was reported during the acute experience. These results shed new light on how LSD-induced shifts in brain dynamics and concomitant subjective experience can be predictive of lasting changes in personality. Hum Brain Mapp 37:3203-3213, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Conceptual development of a transportable/deployable x-ray inspection system for cars and vans

NASA Astrophysics Data System (ADS)

Swift, Roderick D.

1997-02-01

The technology of transmission and backscatter imaging by flying-spot x-ray beams was extended to 450 kV beam energies with the installation of a prototype CargoSearchTM system at Otay Mesa, California in the summer of 1994. CargoSearchTM is a fixed-site system designed for the inspection of large over-the-road vehicles at border crossings. A self-contained, mobile implementation of the same technology has also been developed to scan objects ranging in size from a small car up to a full-scale tractor- trailer rig. MobileSearchTM is able to be moved over ordinary roadways to its intended operating site and set up easily by two or three people, but is currently limited to backscatter imaging only. It also lacks the ability to effectively image the vehicle's undercarriage, which is important for the detection of contraband concealed in the vehicle itself rather than its cargo. There is a need for a transportable, deployable scanning system that combines the self-contained mobility of MobileSearchTM and the combined transmission and backscatter imaging characteristics of CargoSearchTM, including its good geometry for backscatter imaging of the undercarriage of inspected vehicles. Concepts for two approaches that meet these needs are presented.

Defect-mediated transport and electronic irradiation effect in individual domains of CVD-grown monolayer MoS 2

DOE PAGES

Durand, Corentin; Zhang, Xiaoguang; Fowlkes, Jason; ...

2015-01-16

We study the electrical transport properties of atomically thin individual crystalline grains of MoS 2 with four-probe scanning tunneling microscopy. The monolayer MoS 2 domains are synthesized by chemical vapor deposition on SiO 2/Si substrate. Temperature dependent measurements on conductance and mobility show that transport is dominated by an electron charge trapping and thermal release process with very low carrier density and mobility. The effects of electronic irradiation are examined by exposing the film to electron beam in the scanning electron microscope in an ultrahigh vacuum environment. The irradiation process is found to significantly affect the mobility and the carriermore » density of the material, with the conductance showing a peculiar time-dependent relaxation behavior. It is suggested that the presence of defects in active MoS 2 layer and dielectric layer create charge trapping sites, and a multiple trapping and thermal release process dictates the transport and mobility characteristics. The electron beam irradiation promotes the formation of defects and impact the electrical properties of MoS 2. Finally, our study reveals the important roles of defects and the electron beam irradiation effects in the electronic properties of atomic layers of MoS 2.« less

Temperature-induced band shift in bulk γ-InSe by angle-resolved photoemission spectroscopy

NASA Astrophysics Data System (ADS)

Xu, Huanfeng; Wang, Wei; Zhao, Yafei; Zhang, Xiaoqian; Feng, Yue; Tu, Jian; Gu, Chenyi; Sun, Yizhe; Liu, Chang; Nie, Yuefeng; Edmond Turcu, Ion C.; Xu, Yongbing; He, Liang

2018-05-01

Indium selenide (InSe) has recently become popular research topics because of its unique layered crystal structure, direct band gap and high electron mobilities. In this work, we have acquired the electronic structure of bulk γ-InSe at various temperatures using angle-resolved photoemission spectroscopy (ARPES). We have also found that as the temperature decreases, the valence bands of γ-InSe exhibit a monotonic shift to lower binding energies. This band shift is attributed to the change of lattice parameters and has been validated by variable temperature X-ray diffraction measurements and theoretical calculations.

Atomized scan strategy for high definition for VR application

NASA Astrophysics Data System (ADS)

Huang, Shuping; Ran, Feng; Ji, Yuan; Chen, Wendong

2017-10-01

Silicon-based OLED (Organic Light Emitting Display) microdisplay technology begins to attract people's attention in the emerging VR and AR devices. The high display frame refresh rate is an important solution to alleviate the dizziness in VR applications. Traditional display circuit drivers use the analog method or the digital PWM method that follow the serial scan order from the first pixel to the last pixel by using the shift registers. This paper proposes a novel atomized scan strategy based on the digital fractal scan strategy using the pseudo-random scan order. It can be used to realize the high frame refresh rate with the moderate pixel clock frequency in the high definition OLED microdisplay. The linearity of the gray level is also improved compared with the Z fractal scan strategy.

Infrared Sensor System for Mobile-Robot Positioning in Intelligent Spaces

PubMed Central

Gorostiza, Ernesto Martín; Galilea, José Luis Lázaro; Meca, Franciso Javier Meca; Monzú, David Salido; Zapata, Felipe Espinosa; Puerto, Luis Pallarés

2011-01-01

The aim of this work was to position a Mobile Robot in an Intelligent Space, and this paper presents a sensorial system for measuring differential phase-shifts in a sinusoidally modulated infrared signal transmitted from the robot. Differential distances were obtained from these phase-shifts, and the position of the robot was estimated by hyperbolic trilateration. Due to the extremely severe trade-off between SNR, angle (coverage) and real-time response, a very accurate design and device selection was required to achieve good precision with wide coverage and acceptable robot speed. An I/Q demodulator was used to measure phases with one-stage synchronous demodulation to DC. A complete set of results from real measurements, both for distance and position estimations, is provided to demonstrate the validity of the system proposed, comparing it with other similar indoor positioning systems. PMID:22163907

Compact touchless fingerprint reader based on digital variable-focus liquid lens

NASA Astrophysics Data System (ADS)

Tsai, C. W.; Wang, P. J.; Yeh, J. A.

2014-09-01

Identity certification in the cyberworld has always been troublesome if critical information and financial transaction must be processed. Biometric identification is the most effective measure to circumvent the identity issues in mobile devices. Due to bulky and pricy optical design, conventional optical fingerprint readers have been discarded for mobile applications. In this paper, a digital variable-focus liquid lens was adopted for capture of a floating finger via fast focusplane scanning. Only putting a finger in front of a camera could fulfill the fingerprint ID process. This prototyped fingerprint reader scans multiple focal planes from 30 mm to 15 mm in 0.2 second. Through multiple images at various focuses, one of the images is chosen for extraction of fingerprint minutiae used for identity certification. In the optical design, a digital liquid lens atop a webcam with a fixed-focus lens module is to fast-scan a floating finger at preset focus planes. The distance, rolling angle and pitching angle of the finger are stored for crucial parameters during the match process of fingerprint minutiae. This innovative compact touchless fingerprint reader could be packed into a minute size of 9.8*9.8*5 (mm) after the optical design and multiple focus-plane scan function are optimized.

High-resolution mobile optical 3D scanner with color mapping

NASA Astrophysics Data System (ADS)

Ramm, Roland; Bräuer-Burchardt, Christian; Kühmstedt, Peter; Notni, Gunther

2017-07-01

A high-resolution mobile handheld scanning device suitable for 3D data acquisition and analysis for forensic investigations, rapid prototyping, design, quality management, and archaeology with a measurement volume of approximately 325 mm x 200 mm x 100mm and a lateral object resolution of 170 µm developed at our institute is introduced. The scanners weight is 4.4 kg with an optional color DLSR camera. The PC for measurement control and point calculation is included inside the housing. Power supply is realized by rechargeable batteries. Possible operation time is between 30 and 60 minutes. The object distance is between 400 and 500 mm, and the scan time for one 3D shot may vary between 0.1 and 0.5 seconds. The complete 3D result is obtained a few seconds after starting the scan. For higher quality 3D and color images the scanner is attachable to tripod use. Measurement objects larger than the measurement volume must be acquired partly. The different resulting datasets are merged using a suitable software module. The scanner has been successfully used in various applications.

Improving lateral resolution and image quality of optical coherence tomography by the multi-frame superresolution technique for 3D tissue imaging.

PubMed

Shen, Kai; Lu, Hui; Baig, Sarfaraz; Wang, Michael R

2017-11-01

The multi-frame superresolution technique is introduced to significantly improve the lateral resolution and image quality of spectral domain optical coherence tomography (SD-OCT). Using several sets of low resolution C-scan 3D images with lateral sub-spot-spacing shifts on different sets, the multi-frame superresolution processing of these sets at each depth layer reconstructs a higher resolution and quality lateral image. Layer by layer processing yields an overall high lateral resolution and quality 3D image. In theory, the superresolution processing including deconvolution can solve the diffraction limit, lateral scan density and background noise problems together. In experiment, the improved lateral resolution by ~3 times reaching 7.81 µm and 2.19 µm using sample arm optics of 0.015 and 0.05 numerical aperture respectively as well as doubling the image quality has been confirmed by imaging a known resolution test target. Improved lateral resolution on in vitro skin C-scan images has been demonstrated. For in vivo 3D SD-OCT imaging of human skin, fingerprint and retina layer, we used the multi-modal volume registration method to effectively estimate the lateral image shifts among different C-scans due to random minor unintended live body motion. Further processing of these images generated high lateral resolution 3D images as well as high quality B-scan images of these in vivo tissues.

Microelectrode Geochemical Observatory for In Situ Monitoring of Metals Concentration and Mobility in Contaminated Sediments

DTIC Science & Technology

2013-09-01

SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON a. REPORT b. ABSTRACT c . THIS PAGE 19b. TELEPHONE...Report Microelectrode Geochemcial Observatory for In Situ Monitoring of Metals Concentration and Mobility in Contaminated Sediments N62583-11- C -0524...Representative Poor Electrochemical Scans APPENDIX B: Standard Solution Test Data APPENDIX C : Bremerton Porewater Test Data APPENDIX D: Porewater

Scanning tunneling spectroscopy under large current flow through the sample.

PubMed

Maldonado, A; Guillamón, I; Suderow, H; Vieira, S

2011-07-01

We describe a method to make scanning tunneling microscopy/spectroscopy imaging at very low temperatures while driving a constant electric current up to some tens of mA through the sample. It gives a new local probe, which we term current driven scanning tunneling microscopy/spectroscopy. We show spectroscopic and topographic measurements under the application of a current in superconducting Al and NbSe(2) at 100 mK. Perspective of applications of this local imaging method includes local vortex motion experiments, and Doppler shift local density of states studies.

Total error shift patterns for daily CT on rails image-guided radiotherapy to the prostate bed

PubMed Central

2011-01-01

Background To evaluate the daily total error shift patterns on post-prostatectomy patients undergoing image guided radiotherapy (IGRT) with a diagnostic quality computer tomography (CT) on rails system. Methods A total of 17 consecutive post-prostatectomy patients receiving adjuvant or salvage IMRT using CT-on-rails IGRT were analyzed. The prostate bed's daily total error shifts were evaluated for a total of 661 CT scans. Results In the right-left, cranial-caudal, and posterior-anterior directions, 11.5%, 9.2%, and 6.5% of the 661 scans required no position adjustments; 75.3%, 66.1%, and 56.8% required a shift of 1 - 5 mm; 11.5%, 20.9%, and 31.2% required a shift of 6 - 10 mm; and 1.7%, 3.8%, and 5.5% required a shift of more than 10 mm, respectively. There was evidence of correlation between the x and y, x and z, and y and z axes in 3, 3, and 3 of 17 patients, respectively. Univariate (ANOVA) analysis showed that the total error pattern was random in the x, y, and z axis for 10, 5, and 2 of 17 patients, respectively, and systematic for the rest. Multivariate (MANOVA) analysis showed that the (x,y), (x,z), (y,z), and (x, y, z) total error pattern was random in 5, 1, 1, and 1 of 17 patients, respectively, and systematic for the rest. Conclusions The overall daily total error shift pattern for these 17 patients simulated with an empty bladder, and treated with CT on rails IGRT was predominantly systematic. Despite this, the temporal vector trends showed complex behaviors and unpredictable changes in magnitude and direction. These findings highlight the importance of using daily IGRT in post-prostatectomy patients. PMID:22024279

A study on the high temperature-dependence of the electrical properties in a solution-deposited zinc-tin-oxide thin-film transistor operated in the saturation region

NASA Astrophysics Data System (ADS)

Yu, Kyeong Min; Bae, Byung Seong; Jung, Myunghee; Yun, Eui-Jung

2016-06-01

We investigate the effects of high temperatures in the range of 292 - 393 K on the electrical properties of solution-processed amorphous zinc-tin-oxide (a-ZTO) thin-film transistors (TFTs) operated in the saturation region. The fabricated a-ZTO TFTs have a non-patterned bottom gate and top contact structure, and they use a heavily-doped Si wafer and SiO2 as a gate electrode and a gate insulator layer, respectively. In a-ZTO TFTs, the trap release energy ( E TR ) was deduced by using Maxwell-Boltzmann statistics. The decreasing E TR toward zero with increasing gate voltage (the density of trap states ( n s )) in the a-ZTO active layer can be attributed to a shift of the Fermi level toward the mobility edge with increasing gate voltage. The TFTs with low gate voltage (low n s ) exhibit multiple trap and release characteristics and show thermally-activated behavior. In TFTs with a high gate voltage (high n s ), however, we observe decreasing mobility and conductivity with increasing temperature at temperatures ranging from 303 to 363 K. This confirms that the E TR can drop to zero, indicating a shift of the Fermi level beyond the mobility edge. Hence, the mobility edge is detected at the cusp between thermally-activated transport and band transport.

The rotate-plus-shift C-arm trajectory: complete CT data with limited angular rotation

NASA Astrophysics Data System (ADS)

Ritschl, Ludwig; Kuntz, Jan; Kachelrieß, Marc

2015-03-01

In the last decade C-arm-based cone-beam CT became a widely used modality for intraoperative imaging. Typically a C-arm scan is performed using a circle-like trajectory around a region of interest. Therefor an angular range of at least 180° plus fan-angle must be covered to ensure a completely sampled data set. This fact defines some constraints on the geometry and technical specifications of a C-arm system, for example a larger C radius or a smaller C opening respectively. These technical modifications are usually not beneficial in terms of handling and usability of the C-arm during classical 2D applications like fluoroscopy. The method proposed in this paper relaxes the constraint of 180° plus fan-angle rotation to acquire a complete data set. The proposed C-arm trajectory requires a motorization of the orbital axis of the C and of ideally two orthogonal axis in the C plane. The trajectory consists of three parts: A rotation of the C around a defined iso-center and two translational movements parallel to the detector plane at the begin and at the end of the rotation. Combining these three parts to one trajectory enables for the acquisition of a completely sampled dataset using only 180° minus fan-angle of rotation. To evaluate the method we show animal and cadaver scans acquired with a mobile C-arm prototype. We expect that the transition of this method into clinical routine will lead to a much broader use of intraoperative 3D imaging in a wide field of clinical applications.

3D shape measurement system developed on mobile platform

NASA Astrophysics Data System (ADS)

Wu, Zhoujie; Chang, Meng; Shi, Bowen; Zhang, Qican

2017-02-01

Three-dimensional (3-D) shape measurement technology based on structured light has become one hot research field inspired by the increasing requirements. Many methods have been implemented and applied in the industry applications, but most of their equipments are large and complex, cannot be portable. Meanwhile, the popularity of the smart mobile terminals, such as smart phones, provides a platform for the miniaturization and portability of this technology. The measurement system based on phase-shift algorithm and Gray-code pattern under the Android platform on a mobile phone is mainly studied and developed, and it has been encapsulated into a mobile phone application in order to reconstruct 3-D shape data in the employed smart phone easily and quickly. The experimental results of two measured object are given in this paper and demonstrate the application we developed in the mobile platform is effective.

Information Literacy in a Digital Era: Understanding the Impact of Mobile Information for Undergraduate Nursing Students.

PubMed

Doyle, Glynda J; Furlong, Karen E; Secco, Loretta

2016-01-01

Recent entry-to-practice nursing informatics competencies for Registered Nurses in Canada mean nurse educators need educational strategies to promote student competency within the rapidly evolving informatics field. A collaborative research team from three Canadian nursing programs completed a mixed method survey to describe how nursing students used mobile nursing information support and the extent of this support for learning. The Mobile Information Support Evaluation Tool (MISET) assessed Usefulness/Helpfulness, Information Literacy Support, and Use of Evidence-Based Sources. The quantitative and qualitative data were analyzed to describe students' perspectives and the ways they used mobile resources in learning situations. Findings suggest nursing students mainly accessed mobile resources to support clinical learning, and specifically for task-oriented information such as drug medication or patient conditions/diagnoses. Researchers recommend a paradigm shift whereby educators emphasize information literacy in a way that supports evidence-based quality care.

Sensor-Topology Based Simplicial Complex Reconstruction from Mobile Laser Scanning

NASA Astrophysics Data System (ADS)

Guinard, S.; Vallet, B.

2018-05-01

We propose a new method for the reconstruction of simplicial complexes (combining points, edges and triangles) from 3D point clouds from Mobile Laser Scanning (MLS). Our main goal is to produce a reconstruction of a scene that is adapted to the local geometry of objects. Our method uses the inherent topology of the MLS sensor to define a spatial adjacency relationship between points. We then investigate each possible connexion between adjacent points and filter them by searching collinear structures in the scene, or structures perpendicular to the laser beams. Next, we create triangles for each triplet of self-connected edges. Last, we improve this method with a regularization based on the co-planarity of triangles and collinearity of remaining edges. We compare our results to a naive simplicial complexes reconstruction based on edge length.

Effect of molecular asymmetry on the charge transport physics of high mobility n-type molecular semiconductors investigated by scanning Kelvin probe microscopy.

PubMed

Hu, Yuanyuan; Berdunov, Nikolai; Di, Chong-an; Nandhakumar, Iris; Zhang, Fengjiao; Gao, Xike; Zhu, Daoben; Sirringhaus, Henning

2014-07-22

We have investigated the influence of the symmetry of the side chain substituents in high-mobility, solution processable n-type molecular semiconductors on the performance of organic field-effect transistors (OFETs). We compare two molecules with the same conjugated core, but either symmetric or asymmetric side chain substituents, and investigate the transport properties and thin film growth mode using scanning Kelvin probe microscopy (SKPM) and atomic force microscopy (AFM). We find that asymmetric side chains can induce a favorable two-dimensional growth mode with a bilayer structure, which enables ultrathin films with a single bilayer to exhibit excellent transport properties, while the symmetric molecules adopt an unfavorable three-dimensional growth mode in which transport in the first monolayer at the interface is severely hindered by high-resistance grain boundaries.

Doppler optical coherence tomography of retinal circulation.

PubMed

Tan, Ou; Wang, Yimin; Konduru, Ranjith K; Zhang, Xinbo; Sadda, SriniVas R; Huang, David

2012-09-18

Noncontact retinal blood flow measurements are performed with a Fourier domain optical coherence tomography (OCT) system using a circumpapillary double circular scan (CDCS) that scans around the optic nerve head at 3.40 mm and 3.75 mm diameters. The double concentric circles are performed 6 times consecutively over 2 sec. The CDCS scan is saved with Doppler shift information from which flow can be calculated. The standard clinical protocol calls for 3 CDCS scans made with the OCT beam passing through the superonasal edge of the pupil and 3 CDCS scan through the inferonal pupil. This double-angle protocol ensures that acceptable Doppler angle is obtained on each retinal branch vessel in at least 1 scan. The CDCS scan data, a 3-dimensional volumetric OCT scan of the optic disc scan, and a color photograph of the optic disc are used together to obtain retinal blood flow measurement on an eye. We have developed a blood flow measurement software called "Doppler optical coherence tomography of retinal circulation" (DOCTORC). This semi-automated software is used to measure total retinal blood flow, vessel cross section area, and average blood velocity. The flow of each vessel is calculated from the Doppler shift in the vessel cross-sectional area and the Doppler angle between the vessel and the OCT beam. Total retinal blood flow measurement is summed from the veins around the optic disc. The results obtained at our Doppler OCT reading center showed good reproducibility between graders and methods (<10%). Total retinal blood flow could be useful in the management of glaucoma, other retinal diseases, and retinal diseases. In glaucoma patients, OCT retinal blood flow measurement was highly correlated with visual field loss (R(2)>0.57 with visual field pattern deviation). Doppler OCT is a new method to perform rapid, noncontact, and repeatable measurement of total retinal blood flow using widely available Fourier-domain OCT instrumentation. This new technology may improve the practicality of making these measurements in clinical studies and routine clinical practice.

Using Mobile Apps to Communicate Vaccination Records: A City-wide Evaluation with a National Immunization App, Maternal Child Registry and Public Health Authorities.

PubMed

Atkinson, Katherine M; El-Khatib, Ziad; Barnum, Geoffery; Bell, Cameron; Turcotte, Marie-Claude; Murphy, Malia S Q; Teitelbaum, Mari; Chakraborty, Pranesh; Laflamme, Lucie; Wilson, Kumanan

2017-01-01

Medicine is experiencing a paradigm shift, where patients are increasingly involved in the management of their health data. We created a mobile app which permitted parental reporting of immunization status to public health authorities. We describe app use as a proxy for feasibility and acceptability as well as data utility for public health surveillance. The evaluation period ran from April 27, 2015, to April 18, 2017, during which time 2,653 unique children's records were transmitted, containing 36,105 vaccinations. Our findings suggest that mobile immunization reporting is feasible and may be an acceptable complement to existing reporting methods. Measures of data utility suggest that mobile reporting could enable more accurate assessments of vaccine coverage.

Design of an anti-Rician-fading modem for mobile satellite communication systems

NASA Technical Reports Server (NTRS)

Kojima, Toshiharu; Ishizu, Fumio; Miyake, Makoto; Murakami, Keishi; Fujino, Tadashi

1995-01-01

To design a demodulator applicable to mobile satellite communication systems using differential phase shift keying modulation, we have developed key technologies including an anti-Rician-fading demodulation scheme, an initial acquisition scheme, automatic gain control (AGC), automatic frequency control (AFC), and bit timing recovery (BTR). Using these technologies, we have developed one-chip digital signal processor (DSP) modem for mobile terminal, which is compact, of light weight, and of low power consumption. Results of performance test show that the developed DSP modem achieves good performance in terms of bit error ratio in mobile satellite communication environment, i.e., Rician fading channel. It is also shown that the initial acquisition scheme acquires received signal rapidly even if the carrier-to-noise power ratio (CNR) of the received signal is considerably low.

Bright blue-shifted fluorescent proteins with Cys in the GAF domain engineered from bacterial phytochromes: fluorescence mechanisms and excited-state dynamics.

PubMed

Hontani, Yusaku; Shcherbakova, Daria M; Baloban, Mikhail; Zhu, Jingyi; Verkhusha, Vladislav V; Kennis, John T M

2016-11-18

Near-infrared fluorescent proteins (NIR FPs) engineered from bacterial phytochromes (BphPs) are of great interest for in vivo imaging. They utilize biliverdin (BV) as a chromophore, which is a heme degradation product, and therefore they are straightforward to use in mammalian tissues. Here, we report on fluorescence properties of NIR FPs with key alterations in their BV binding sites. BphP1-FP, iRFP670 and iRFP682 have Cys residues in both PAS and GAF domains, rather than in the PAS domain alone as in wild-type BphPs. We found that NIR FP variants with Cys in the GAF or with Cys in both PAS and GAF show blue-shifted emission with long fluorescence lifetimes. In contrast, mutants with Cys in the PAS only or no Cys residues at all exhibit red-shifted emission with shorter lifetimes. Combining these results with previous biochemical and BphP1-FP structural data, we conclude that BV adducts bound to Cys in the GAF are the origin of bright blue-shifted fluorescence. We propose that the long fluorescence lifetime follows from (i) a sterically more constrained thioether linkage, leaving less mobility for ring A than in canonical BphPs, and (ii) that π-electron conjugation does not extend on ring A, making excited-state deactivation less sensitive to ring A mobility.

Irradiation defect dispersions and effective dislocation mobility in strained ferritic grains: A statistical analysis based on 3D dislocation dynamics simulations

NASA Astrophysics Data System (ADS)

Li, Y.; Robertson, C.

2018-06-01

The influence of irradiation defect dispersions on plastic strain spreading is investigated by means of three-dimensional dislocation dynamics (DD) simulations, accounting for thermally activated slip and cross-slip mechanisms in Fe-2.5%Cr grains. The defect-induced evolutions of the effective screw dislocation mobility are evaluated by means of statistical comparisons, for various defect number density and defect size cases. Each comparison is systematically associated with a quantitative Defect-Induced Apparent Straining Temperature shift (or «ΔDIAT»), calculated without any adjustable parameters. In the investigated cases, the ΔDIAT level associated with a given defect dispersion closely replicates the measured ductile to brittle transition temperature shift (ΔDBTT) due to the same, actual defect dispersion. The results are further analyzed in terms of dislocation-based plasticity mechanisms and their possible relations with the dose-dependent changes of the ductile to brittle transition temperature.

Transmission of influenza reflects seasonality of wild birds across the annual cycle

USGS Publications Warehouse

Hill, Nichola J.; Ma, Eric J.; Meixell, Brandt W.; Lindberg, Mark S.; Boyce, Walter M.; Runstadler, Jonathan A.

2016-01-01

Influenza A Viruses (IAV) in nature must overcome shifting transmission barriers caused by the mobility of their primary host, migratory wild birds, that change throughout the annual cycle. Using a phylogenetic network of viral sequences from North American wild birds (2008–2011) we demonstrate a shift from intraspecific to interspecific transmission that along with reassortment, allows IAV to achieve viral flow across successive seasons from summer to winter. Our study supports amplification of IAV during summer breeding seeded by overwintering virus persisting locally and virus introduced from a wide range of latitudes. As birds migrate from breeding sites to lower latitudes, they become involved in transmission networks with greater connectivity to other bird species, with interspecies transmission of reassortant viruses peaking during the winter. We propose that switching transmission dynamics may be a critical strategy for pathogens that infect mobile hosts inhabiting regions with strong seasonality.

Non-urban mobile radio market demand forecast

NASA Technical Reports Server (NTRS)

Castruccio, P. A.; Cooper, J.

1982-01-01

A national nonmetropolitan land mobile traffic model for 1990-2000 addresses user classes, density classes, traffic mix statistics, distance distribution, geographic distribution, price elasticity, and service quality elasticity. Traffic demands for business, special industrial, and police were determined on the basis of surveys in 73 randomly selected nonurban counties. The selected services represent 69% of total demand. The results were extrapolated to all services in the non-SMSA areas of the contiguous United States. Radiotelephone services were considered separately. Total non-SMSA mobile radio demand (one way) estimates are given. General functional requirements include: hand portability, privacy, reduction of blind spots, two way data transmission, position location, slow scan imagery.

Characterization and frequency-thermal response of electrical properties of Cu nanoferrite prepared by sol-gel method

NASA Astrophysics Data System (ADS)

Moghadasi, Fatemeh S.; Daadmehr, Vahid; Kashfi, Monire

2016-10-01

In this paper, we have synthesized copper ferrite nanocrystals using sol-gel method. X-ray diffraction (XRD) analysis confirms that the ferrite has cubic spinal structure and shows Jahn-Teller effect. Also, scan electron microscope (SEM) image demonstrates that grains are nano size order. We showed that the dielectric properties are compatible with the Maxwell-Wagner model and phenomenological Koop's theory. Loss tangent and conductivity of the ferrite have been measured to have small values of 2.4 and 2×10-7 S/m, respectively at room temperature and at 12 Hz. Conductivity has been investigated in terms of localized hopping mechanism and good obedience of Jonscher's law was observed. Variation of activation energy was studied and showed a transition temperature of 443 °K. The electrical modulus shows relaxation of interfacial polarization with relaxation time of 0.318 ms at 24 °C and 15.9 μs at 72 °C. In Impedance spectroscopy, we observed the effects of grain and grain boundary. By increasing temperature, capacity and conduction would increase which show easier polarization process and a semiconducting behavior. Also, relaxation times are shifted to smaller values to represent increasing the electrons mobility.

Microelectrode Geochemcial Observatory for In Situ Monitoring of Metals Concentration and Mobility in Contaminated Sediments

DTIC Science & Technology

2013-09-01

ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON a. REPORT b. ABSTRACT c . THIS PAGE 19b. TELEPHONE NUMBER (include area code) Standard Form 298...Monitoring of Metals Concentration and Mobility in Contaminated Sediments N62583-11- C -0524 NAVFAC EXWC - Nancy Ruiz, Ph.D. Geosyntec Consultants...OF APPENDICES APPENDIX A: Representative Poor Electrochemical Scans APPENDIX B: Standard Solution Test Data APPENDIX C : Bremerton Porewater Test

Mobile robot motion estimation using Hough transform

NASA Astrophysics Data System (ADS)

Aldoshkin, D. N.; Yamskikh, T. N.; Tsarev, R. Yu

2018-05-01

This paper proposes an algorithm for estimation of mobile robot motion. The geometry of surrounding space is described with range scans (samples of distance measurements) taken by the mobile robot’s range sensors. A similar sample of space geometry in any arbitrary preceding moment of time or the environment map can be used as a reference. The suggested algorithm is invariant to isotropic scaling of samples or map that allows using samples measured in different units and maps made at different scales. The algorithm is based on Hough transform: it maps from measurement space to a straight-line parameters space. In the straight-line parameters, space the problems of estimating rotation, scaling and translation are solved separately breaking down a problem of estimating mobile robot localization into three smaller independent problems. The specific feature of the algorithm presented is its robustness to noise and outliers inherited from Hough transform. The prototype of the system of mobile robot orientation is described.

Measuring chromatic aberrations in imaging systems using plasmonic nanoparticles.

PubMed

Gennaro, Sylvain D; Roschuk, Tyler R; Maier, Stefan A; Oulton, Rupert F

2016-04-01

We demonstrate a method to measure chromatic aberrations of microscope objectives with metallic nanoparticles using white light. Extinction spectra are recorded while scanning a single nanoparticle through a lens's focal plane. We show a direct correlation between the focal wavelength and the longitudinal chromatic focal shift through our analysis of the variations between the scanned extinction spectra at each scan position and the peak extinction over the entire scan. The method has been tested on achromat and apochromat objectives using aluminum disks varying in size from 260-520 nm. Our method is straightforward, robust, low cost, and broadband with a sensitivity suitable for assessing longitudinal chromatic aberrations in high-numerical-aperture apochromatic corrected lenses.

Tuning the resonance frequencies and mode shapes in a large range multi-degree of freedom micromirror.

PubMed

Morrison, Jessica; Imboden, Matthias; Bishop, David J

2017-04-03

The ability to actively shift the primary resonance of a 2D scanning micromirror allows the user to set the scanning direction, set the scanning frequency, and lift otherwise degenerate modes in a symmetrically designed system. In most cases, resonant scanning micromirrors require frequency stability in order to perform imaging and projection functions properly. This paper suggests a method to tune the tip and tilt resonant frequencies in real time while actively suppressing or allowing degeneracy of the two modes in a symmetric electrothermal micromirror. We show resonant frequency tuning with a range of degeneracy separation of 470 Hz or by approximately ±15% and controllable coupling.

Pseudo-random dynamic address configuration (PRDAC) algorithm for mobile ad hoc networks

NASA Astrophysics Data System (ADS)

Wu, Shaochuan; Tan, Xuezhi

2007-11-01

By analyzing all kinds of address configuration algorithms, this paper provides a new pseudo-random dynamic address configuration (PRDAC) algorithm for mobile ad hoc networks. Based on PRDAC, the first node that initials this network randomly chooses a nonlinear shift register that can generates an m-sequence. When another node joins this network, the initial node will act as an IP address configuration sever to compute an IP address according to this nonlinear shift register, and then allocates this address and tell the generator polynomial of this shift register to this new node. By this means, when other node joins this network, any node that has obtained an IP address can act as a server to allocate address to this new node. PRDAC can also efficiently avoid IP conflicts and deal with network partition and merge as same as prophet address (PA) allocation and dynamic configuration and distribution protocol (DCDP). Furthermore, PRDAC has less algorithm complexity, less computational complexity and more sufficient assumption than PA. In addition, PRDAC radically avoids address conflicts and maximizes the utilization rate of IP addresses. Analysis and simulation results show that PRDAC has rapid convergence, low overhead and immune from topological structures.

Load shift potential of electric vehicles in Europe

NASA Astrophysics Data System (ADS)

Babrowski, Sonja; Heinrichs, Heidi; Jochem, Patrick; Fichtner, Wolf

2014-06-01

Many governments highly encourage electric mobility today, aiming at a high market penetration. This development would bring forth an impact on the energy system, which strongly depends on the driving and charging behavior of the users. While an uncontrolled immediate charging might strain the local grid and/or higher peak loads, there are benefits to be gained by a controlled charging. We examine six European mobility studies in order to display the effects of controlled and uncontrolled unidirectional charging. Taking into account country-specific driving patterns, we generate for each country a charging load curve corresponding to uncontrolled charging and consider the corresponding parking time at charging facilities in order to identify load shift potentials. The main results are that besides the charging power of the vehicles, the possibility to charge at the work place has a significant influence on the uncontrolled charging curve. Neither national nor regional differences are as significant. When charging is only possible at home, the vehicle availability at charging facilities during the day for all countries is at least 24%. With the additional possibility to charge at work, at least 45% are constantly available. Accordingly, we identified a big potential for load shifting through controlled charging.

The Cutting Edge of Affinity Electrophoresis Technology

PubMed Central

Kinoshita, Eiji; Kinoshita-Kikuta, Emiko; Koike, Tohru

2015-01-01

Affinity electrophoresis is an important technique that is widely used to separate and analyze biomolecules in the fields of biology and medicine. Both quantitative and qualitative information can be gained through affinity electrophoresis. Affinity electrophoresis can be applied through a variety of strategies, such as mobility shift electrophoresis, charge shift electrophoresis or capillary affinity electrophoresis. These strategies are based on changes in the electrophoretic patterns of biological macromolecules that result from interactions or complex-formation processes that induce changes in the size or total charge of the molecules. Nucleic acid fragments can be characterized through their affinity to other molecules, for example transcriptional factor proteins. Hydrophobic membrane proteins can be identified by means of a shift in the mobility induced by a charged detergent. The various strategies have also been used in the estimation of association/disassociation constants. Some of these strategies have similarities to affinity chromatography, in that they use a probe or ligand immobilized on a supported matrix for electrophoresis. Such methods have recently contributed to profiling of major posttranslational modifications of proteins, such as glycosylation or phosphorylation. Here, we describe advances in analytical techniques involving affinity electrophoresis that have appeared during the last five years. PMID:28248262

Omni-directional L-band antenna for mobile communications

NASA Technical Reports Server (NTRS)

Kim, C. S.; Moldovan, N.; Kijesky, J.

1988-01-01

The principle and design of an L-band omni-directional mobile communication antenna are discussed. The antenna is a circular wave guide aperture with hybrid circuits attached to higher order mode excitation. It produces polarized and symmetric two split beams in elevation. The circular waveguide is fed by eight probes with a 90 degree phase shift between their inputs. Radiation pattern characteristics are controlled by adjusting the aperture diameter and mode excitation. This antenna satisfies gain requirements as well as withstanding the harsh environment.

Trellis coded multilevel DPSK system with doppler correction for mobile satellite channels

NASA Technical Reports Server (NTRS)

Divsalar, Dariush (Inventor); Simon, Marvin K. (Inventor)

1991-01-01

A trellis coded multilevel differential phase shift keyed mobile communication system. The system of the present invention includes a trellis encoder for translating input signals into trellis codes; a differential encoder for differentially encoding the trellis coded signals; a transmitter for transmitting the differentially encoded trellis coded signals; a receiver for receiving the transmitted signals; a differential demodulator for demodulating the received differentially encoded trellis coded signals; and a trellis decoder for decoding the differentially demodulated signals.

Prenatal exposure of mice to diethylstilbestrol disrupts T-cell differentiation by regulating Fas/Fas ligand expression through estrogen receptor element and nuclear factor-κB motifs.

PubMed

Singh, Narendra P; Singh, Udai P; Nagarkatti, Prakash S; Nagarkatti, Mitzi

2012-11-01

Prenatal exposure to diethylstilbestrol (DES) is known to cause altered immune functions and increased susceptibility to autoimmune disease in humans. In the current study, we investigated the effect of prenatal exposure to DES on thymocyte differentiation involving apoptotic pathways. Prenatal DES exposure caused thymic atrophy, apoptosis, and up-regulation of Fas and Fas ligand (FasL) expression in thymocytes. To examine the mechanism underlying DES-mediated regulation of Fas and FasL, we performed luciferase assays using T cells transfected with luciferase reporter constructs containing full-length Fas or FasL promoters. There was significant luciferase induction in the presence of Fas or FasL promoters after DES exposure. Further analysis demonstrated the presence of several cis-regulatory motifs on both Fas and FasL promoters. When DES-induced transcription factors were analyzed, estrogen receptor element (ERE), nuclear factor κB (NF-κB), nuclear factor of activated T cells (NF-AT), and activator protein-1 motifs on the Fas promoter, as well as ERE, NF-κB, and NF-AT motifs on the FasL promoter, showed binding affinity with the transcription factors. Electrophoretic mobility-shift assays were performed to verify the binding affinity of cis-regulatory motifs of Fas or FasL promoters with transcription factors. There was shift in mobility of probes (ERE or NF-κB2) of both Fas and FasL in the presence of nuclear proteins from DES-treated cells, and the shift was specific to DES because these probes failed to shift their mobility in the presence of nuclear proteins from vehicle-treated cells. Together, the current study demonstrates that prenatal exposure to DES triggers significant alterations in apoptotic molecules expressed on thymocytes, which may affect T-cell differentiation and cause long-term effects on the immune functions.

Prenatal Exposure of Mice to Diethylstilbestrol Disrupts T-Cell Differentiation by Regulating Fas/Fas Ligand Expression through Estrogen Receptor Element and Nuclear Factor-κB Motifs

PubMed Central

Singh, Narendra P.; Singh, Udai P.; Nagarkatti, Prakash S.

2012-01-01

Prenatal exposure to diethylstilbestrol (DES) is known to cause altered immune functions and increased susceptibility to autoimmune disease in humans. In the current study, we investigated the effect of prenatal exposure to DES on thymocyte differentiation involving apoptotic pathways. Prenatal DES exposure caused thymic atrophy, apoptosis, and up-regulation of Fas and Fas ligand (FasL) expression in thymocytes. To examine the mechanism underlying DES-mediated regulation of Fas and FasL, we performed luciferase assays using T cells transfected with luciferase reporter constructs containing full-length Fas or FasL promoters. There was significant luciferase induction in the presence of Fas or FasL promoters after DES exposure. Further analysis demonstrated the presence of several cis-regulatory motifs on both Fas and FasL promoters. When DES-induced transcription factors were analyzed, estrogen receptor element (ERE), nuclear factor κB (NF-κB), nuclear factor of activated T cells (NF-AT), and activator protein-1 motifs on the Fas promoter, as well as ERE, NF-κB, and NF-AT motifs on the FasL promoter, showed binding affinity with the transcription factors. Electrophoretic mobility-shift assays were performed to verify the binding affinity of cis-regulatory motifs of Fas or FasL promoters with transcription factors. There was shift in mobility of probes (ERE or NF-κB2) of both Fas and FasL in the presence of nuclear proteins from DES-treated cells, and the shift was specific to DES because these probes failed to shift their mobility in the presence of nuclear proteins from vehicle-treated cells. Together, the current study demonstrates that prenatal exposure to DES triggers significant alterations in apoptotic molecules expressed on thymocytes, which may affect T-cell differentiation and cause long-term effects on the immune functions. PMID:22888145

Fluorescence of nitrobenzoxadiazole (NBD)-labeled lipids in model membranes is connected not to lipid mobility but to probe location.

PubMed

Amaro, Mariana; Filipe, Hugo A L; Prates Ramalho, J P; Hof, Martin; Loura, Luís M S

2016-03-14

Nitrobenzoxadiazole (NBD)-labeled lipids are popular fluorescent membrane probes. However, the understanding of important aspects of the photophysics of NBD remains incomplete, including the observed shift in the emission spectrum of NBD-lipids to longer wavelengths following excitation at the red edge of the absorption spectrum (red-edge excitation shift or REES). REES of NBD-lipids in membrane environments has been previously interpreted as reflecting restricted mobility of solvent surrounding the fluorophore. However, this requires a large change in the dipole moment (Δμ) of NBD upon excitation. Previous calculations of the value of Δμ of NBD in the literature have been carried out using outdated semi-empirical methods, leading to conflicting values. Using up-to-date density functional theory methods, we recalculated the value of Δμ and verified that it is rather small (∼2 D). Fluorescence measurements confirmed that the value of REES is ∼16 nm for 1,2-dioleoyl-sn-glycero-3-phospho-l-serine-N-(NBD) (NBD-PS) in dioleoylphosphatidylcholine vesicles. However, the observed shift is independent of both the temperature and the presence of cholesterol and is therefore insensitive to the mobility and hydration of the membrane. Moreover, red-edge excitation leads to an increased contribution of the decay component with a shorter lifetime, whereas time-resolved emission spectra of NBD-PS displayed an atypical blue shift following excitation. This excludes restrictions to solvent relaxation as the cause of the measured REES and TRES of NBD, pointing instead to the heterogeneous transverse location of probes as the origin of these effects. The latter hypothesis was confirmed by molecular dynamics simulations, from which the calculated heterogeneity of the hydration and location of NBD correlated with the measured fluorescence lifetimes/REES. Globally, our combination of theoretical and experiment-based techniques has led to a considerably improved understanding of the photophysics of NBD and a reinterpretation of its REES in particular.

Tracking Human Mobility Using WiFi Signals.

PubMed

Sapiezynski, Piotr; Stopczynski, Arkadiusz; Gatej, Radu; Lehmann, Sune

2015-01-01

We study six months of human mobility data, including WiFi and GPS traces recorded with high temporal resolution, and find that time series of WiFi scans contain a strong latent location signal. In fact, due to inherent stability and low entropy of human mobility, it is possible to assign location to WiFi access points based on a very small number of GPS samples and then use these access points as location beacons. Using just one GPS observation per day per person allows us to estimate the location of, and subsequently use, WiFi access points to account for 80% of mobility across a population. These results reveal a great opportunity for using ubiquitous WiFi routers for high-resolution outdoor positioning, but also significant privacy implications of such side-channel location tracking.

Nanostructures formed by cyclodextrin covered procainamide through supramolecular self assembly - Spectral and molecular modeling study

NASA Astrophysics Data System (ADS)

Rajendiran, N.; Mohandoss, T.; Sankaranarayanan, R. K.

2015-02-01

Inclusion complexation behavior of procainamide (PCA) with two cyclodextrins (α-CD and β-CD) were analyzed by absorption, fluorescence, scanning electron microscope (SEM), transmission electron microscope (TEM), Raman image, FT-IR, differential scanning colorimeter (DSC), Powder X ray diffraction (XRD) and 1H NMR. Blue shift was observed in β-CD whereas no significant spectral shift observed in α-CD. The inclusion complex formation results suggest that water molecules also present in the inside of the CD cavity. The present study revealed that the phenyl ring of the PCA drug is entrapped in the CD cavity. Cyclodextrin studies show that PCA forms 1:2 inclusion complex with α-CD and β-CD. PCA:α-CD complex form nano-sized particles (46 nm) and PCA:β-CD complex form self-assembled to micro-sized tubular structures. The shape-shifting of 2D nanosheets into 1D microtubes by simple rolling mechanism were analysed by micro-Raman and TEM images. Thermodynamic parameters (ΔH, ΔG and ΔS) of inclusion process were determined from semiempirical PM3 calculations.

Determination of Young's modulus of individual electrospun nanofibers by microcantilever vibration method

NASA Astrophysics Data System (ADS)

Yuya, Philip A.; Wen, Yongkui; Turner, Joseph A.; Dzenis, Yuris A.; Li, Zheng

2007-03-01

The authors report a technique for measuring Young's modulus of a single electrospun nanofiber using the vibrations of two microcantilevers coupled with the nanofiber. The modulus is calculated from the resonant frequency shift resulting from the nanofiber. Polyacrylonitrile nanofibers (200nm diameter) were collected during electrospinning and wrapped on two similar microcantilevers causing a shift in first resonance from 10.0to19.4kHz. Finite element analysis was used to analyze the frequency shift using images from a scanning electron microscope giving a modulus of the as-spun polyacrylonitrile nanofiber of 26.8GPa.

Vacuum Bloch-Siegert shift in Landau polaritons with ultra-high cooperativity

NASA Astrophysics Data System (ADS)

Li, Xinwei; Bamba, Motoaki; Zhang, Qi; Fallahi, Saeed; Gardner, Geoff C.; Gao, Weilu; Lou, Minhan; Yoshioka, Katsumasa; Manfra, Michael J.; Kono, Junichiro

2018-06-01

A two-level system resonantly interacting with an a.c. magnetic or electric field constitutes the physical basis of diverse phenomena and technologies. However, Schrödinger's equation for this seemingly simple system can be solved exactly only under the rotating-wave approximation, which neglects the counter-rotating field component. When the a.c. field is sufficiently strong, this approximation fails, leading to a resonance-frequency shift known as the Bloch-Siegert shift. Here, we report the vacuum Bloch-Siegert shift, which is induced by the ultra-strong coupling of matter with the counter-rotating component of the vacuum fluctuation field in a cavity. Specifically, an ultra-high-mobility two-dimensional electron gas inside a high-Q terahertz cavity in a quantizing magnetic field revealed ultra-narrow Landau polaritons, which exhibited a vacuum Bloch-Siegert shift up to 40 GHz. This shift, clearly distinguishable from the photon-field self-interaction effect, represents a unique manifestation of a strong-field phenomenon without a strong field.

ScaMo: Realisation of an OO-functional DSL for cross platform mobile applications development

NASA Astrophysics Data System (ADS)

Macos, Dragan; Solymosi, Andreas

2013-10-01

The software market is dynamically changing: the Internet is going mobile, the software applications are shifting from the desktop hardware onto the mobile devices. The largest markets are the mobile applications for iOS, Android and Windows Phone and for the purpose the typical programming languages include Objective-C, Java and C ♯. The realization of the native applications implies the integration of the developed software into the environments of mentioned mobile operating systems to enable the access to different hardware components of the devices: GPS module, display, GSM module, etc. This paper deals with the definition and possible implementation of an environment for the automatic application generation for multiple mobile platforms. It is based on a DSL for mobile application development, which includes the programming language Scala and a DSL defined in Scala. As part of a multi-stage cross-compiling algorithm, this language is translated into the language of the affected mobile platform. The advantage of our method lies in the expressiveness of the defined language and the transparent source code translation between different languages, which implies, for example, the advantages of debugging and development of the generated code.

Frequency-dependent polarization-angle-phase-shift in the microwave-induced magnetoresistance oscillations

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

Liu, Han-Chun; Ye, Tianyu; Mani, R. G.

2015-02-14

Linear polarization angle, θ, dependent measurements of the microwave radiation-induced oscillatory magnetoresistance, R{sub xx}, in high mobility GaAs/AlGaAs 2D electron devices have shown a θ dependence in the oscillatory amplitude along with magnetic field, frequency, and extrema-dependent phase shifts, θ{sub 0}. Here, we suggest a microwave frequency dependence of θ{sub 0}(f) using an analysis that averages over other smaller contributions, when those contributions are smaller than estimates of the experimental uncertainty.

Scanning Cloud Radar Observations at the ARM sites

NASA Astrophysics Data System (ADS)

Kollias, P.; Clothiaux, E. E.; Shupe, M.; Widener, K.; Bharadwaj, N.; Miller, M. A.; Verlinde, H.; Luke, E. P.; Johnson, K. L.; Jo, I.; Tatarevic, A.; Lamer, K.

2012-12-01

Recently, the DOE Atmospheric Radiation Measurement (ARM) program upgraded its fixed and mobile facilities with the acquisition of state-of-the-art scanning, dual-wavelength, polarimetric, Doppler cloud radars. The scanning ARM cloud radars (SACR's) are the most expensive and significant radar systems at all ARM sites and eight SACR systems will be operational at ARM sites by the end of 2013. The SACR's are the primary instruments for the detection of 3D cloud properties (boundaries, volume cloud fractional coverage, liquid water content, dynamics, etc.) beyond the soda-straw (profiling) limited view. Having scanning capabilities with two frequencies and polarization allows more accurate probing of a variety of cloud systems (e.g., drizzle and shallow, warm rain), better correction for attenuation, use of attenuation for liquid water content retrievals, and polarimetric and dual-wavelength ratio characterization of non-spherical particles for improved ice crystal habit identification. Examples of SACR observations from four ARM sites are presented here: the fixed sites at Southern Great Plains (SGP) and North Slope of Alaska (NSA), and the mobile facility deployments at Graciosa Island, Azores and Cape Cod, Massachusetts. The 3D cloud structure is investigated both at the macro-scale (20-50 km) and cloud-scale (100-500 m). Doppler velocity measurements are corrected for velocity folding and are used either to describe the in-cloud horizontal wind profile or the 3D vertical air motions.

Improving lateral resolution and image quality of optical coherence tomography by the multi-frame superresolution technique for 3D tissue imaging

PubMed Central

Shen, Kai; Lu, Hui; Baig, Sarfaraz; Wang, Michael R.

2017-01-01

The multi-frame superresolution technique is introduced to significantly improve the lateral resolution and image quality of spectral domain optical coherence tomography (SD-OCT). Using several sets of low resolution C-scan 3D images with lateral sub-spot-spacing shifts on different sets, the multi-frame superresolution processing of these sets at each depth layer reconstructs a higher resolution and quality lateral image. Layer by layer processing yields an overall high lateral resolution and quality 3D image. In theory, the superresolution processing including deconvolution can solve the diffraction limit, lateral scan density and background noise problems together. In experiment, the improved lateral resolution by ~3 times reaching 7.81 µm and 2.19 µm using sample arm optics of 0.015 and 0.05 numerical aperture respectively as well as doubling the image quality has been confirmed by imaging a known resolution test target. Improved lateral resolution on in vitro skin C-scan images has been demonstrated. For in vivo 3D SD-OCT imaging of human skin, fingerprint and retina layer, we used the multi-modal volume registration method to effectively estimate the lateral image shifts among different C-scans due to random minor unintended live body motion. Further processing of these images generated high lateral resolution 3D images as well as high quality B-scan images of these in vivo tissues. PMID:29188089

Trellis coding with Continuous Phase Modulation (CPM) for satellite-based land-mobile communications

NASA Technical Reports Server (NTRS)

1989-01-01

This volume of the final report summarizes the results of our studies on the satellite-based mobile communications project. It includes: a detailed analysis, design, and simulations of trellis coded, full/partial response CPM signals with/without interleaving over various Rician fading channels; analysis and simulation of computational cutoff rates for coherent, noncoherent, and differential detection of CPM signals; optimization of the complete transmission system; analysis and simulation of power spectrum of the CPM signals; design and development of a class of Doppler frequency shift estimators; design and development of a symbol timing recovery circuit; and breadboard implementation of the transmission system. Studies prove the suitability of the CPM system for mobile communications.

Cycle of charge carrier states with formation and extinction of a floating gate in an ambipolar tetracyanoquaterthienoquinoid-based field-effect transistor

NASA Astrophysics Data System (ADS)

Itoh, Takuro; Toyota, Taro; Higuchi, Hiroyuki; Matsushita, Michio M.; Suzuki, Kentaro; Sugawara, Tadashi

2017-03-01

A tetracyanoquaterthienoquinoid (TCT4Q)-based field effect transistor is characterized by the ambipolar transfer characteristics and the facile shift of the threshold voltage induced by the bias stress. The trapping and detrapping kinetics of charge carriers was investigated in detail by the temperature dependence of the decay of source-drain current (ISD). We found a repeatable formation of a molecular floating gate is derived from a 'charge carrier-and-gate' cycle comprising four stages, trapping of mobile carriers, formation of a floating gate, induction of oppositely charged mobile carriers, and recombination between mobile and trapped carriers to restore the initial state.

Coordination of Mobile Devices : Technology and Standards Scan.

DOT National Transportation Integrated Search

2015-06-19

The connected vehicle environment was envisioned as a means of exchanging messages through a connected vehicle fleet. The majority of the current connected vehicle environment focuses on the vehicle, by supporting the exchange of messages from vehicl...

Multi-Beam Sonar Infrastructure Mapping Research

DOT National Transportation Integrated Search

2017-10-01

The hydraulics unit in MnDOTs bridge office applied for a research grant to develop in-house underwater acoustic 3D imaging capabilities. This research report presents both stationary and mobile scanning techniques, outlines the setup of both syst...

Synthesis of nanoparticles in a flame aerosol reactor with independent and strict control of their size, crystal phase and morphology

NASA Astrophysics Data System (ADS)

Jiang, Jingkun; Chen, Da-Ren; Biswas, Pratim

2007-07-01

A flame aerosol reactor (FLAR) was developed to synthesize nanoparticles with desired properties (crystal phase and size) that could be independently controlled. The methodology was demonstrated for TiO2 nanoparticles, and this is the first time that large sets of samples with the same size but different crystal phases (six different ratios of anatase to rutile in this work) were synthesized. The degree of TiO2 nanoparticle agglomeration was determined by comparing the primary particle size distribution measured by scanning electron microscopy (SEM) to the mobility-based particle size distribution measured by online scanning mobility particle spectrometry (SMPS). By controlling the flame aerosol reactor conditions, both spherical unagglomerated particles and highly agglomerated particles were produced. To produce monodisperse nanoparticles, a high throughput multi-stage differential mobility analyser (MDMA) was used in series with the flame aerosol reactor. Nearly monodisperse nanoparticles (geometric standard deviation less than 1.05) could be collected in sufficient mass quantities (of the order of 10 mg) in reasonable time (1 h) that could be used in other studies such as determination of functionality or biological effects as a function of size.

Classification of Mobile Laser Scanning Point Clouds from Height Features

NASA Astrophysics Data System (ADS)

Zheng, M.; Lemmens, M.; van Oosterom, P.

2017-09-01

The demand for 3D maps of cities and road networks is steadily growing and mobile laser scanning (MLS) systems are often the preferred geo-data acquisition method for capturing such scenes. Because MLS systems are mounted on cars or vans they can acquire billions of points of road scenes within a few hours of survey. Manual processing of point clouds is labour intensive and thus time consuming and expensive. Hence, the need for rapid and automated methods for 3D mapping of dense point clouds is growing exponentially. The last five years the research on automated 3D mapping of MLS data has tremendously intensified. In this paper, we present our work on automated classification of MLS point clouds. In the present stage of the research we exploited three features - two height components and one reflectance value, and achieved an overall accuracy of 73 %, which is really encouraging for further refining our approach.

Using Mobile Laser Scanning Data for Features Extraction of High Accuracy Driving Maps

NASA Astrophysics Data System (ADS)

Yang, Bisheng; Liu, Yuan; Liang, Fuxun; Dong, Zhen

2016-06-01

High Accuracy Driving Maps (HADMs) are the core component of Intelligent Drive Assistant Systems (IDAS), which can effectively reduce the traffic accidents due to human error and provide more comfortable driving experiences. Vehicle-based mobile laser scanning (MLS) systems provide an efficient solution to rapidly capture three-dimensional (3D) point clouds of road environments with high flexibility and precision. This paper proposes a novel method to extract road features (e.g., road surfaces, road boundaries, road markings, buildings, guardrails, street lamps, traffic signs, roadside-trees, power lines, vehicles and so on) for HADMs in highway environment. Quantitative evaluations show that the proposed algorithm attains an average precision and recall in terms of 90.6% and 91.2% in extracting road features. Results demonstrate the efficiencies and feasibilities of the proposed method for extraction of road features for HADMs.

CBCT volumetric coverage extension using a pair of complementary circular scans with complementary kV detector lateral and longitudinal offsets

NASA Astrophysics Data System (ADS)

Yang, Deshan; Li, H. Harold; Goddu, S. Murty; Tan, Jun

2014-10-01

Onboard cone-beam CT (CBCT) has been widely used in image guided radiation therapy. However, the longitudinal coverage is only 15.5 cm in the pelvis scan mode. As a result, a single CBCT scan cannot cover the planning target volume in the longitudinal direction for over 80% of the patients. The common approach is to use double- or multiple-circular scans and then combine multiple CBCT volumes after reconstruction. However it raises concerns regarding doubled imaging dose at the imaging beam junctions due to beam divergence. In this work, we present a new method, DSCS (Dual Scan with Complementary Shifts), to address the CBCT coverage problem using a pair of complementary circular scans. In DSCS, two circular scans were performed at 39.5 cm apart longitudinally. In the superior scan, the detector panel was offset by 16 cm to the left, 15 cm to the inferior. In the inferior scan, the detector panel was shifted 16 cm to the right and 15 cm to the superior. The effective imaging volume is 39.5 cm longitudinally with a 45 cm lateral field-of-view (FOV). Half beam blocks were used to confine the imaging radiation inside the volume of interest. A new image reconstruction algorithm was developed, based on the Feldkamp-Davis-Kress cone-beam CT reconstruction algorithm, to support the DSCS scanning geometry. Digital phantom simulations were performed to demonstrate the feasibility of DSCS. Physical phantom studies were performed using an anthropomorphic phantom on a commercial onboard CBCT system. With basic scattering corrections, the reconstruction results were acceptable. Other issues, including the discrepancy in couch vertical at different couch longitudinal positions, and the inaccuracy in couch table longitudinal movement, were manually corrected during the reconstruction process. In conclusion, the phantom studies showed that, using DSCS, a 39.5 cm longitudinal coverage with a 45 cm FOV was accomplished. The efficiency of imaging dose usage was near 100%. This proposed method could be potentially useful for image guidance and subsequent treatment plan adaptation.

Cloud-based crowd sensing: a framework for location-based crowd analyzer and advisor

NASA Astrophysics Data System (ADS)

Aishwarya, K. C.; Nambi, A.; Hudson, S.; Nadesh, R. K.

2017-11-01

Cloud computing is an emerging field of computer science to integrate and explore large and powerful computing systems and storages for personal and also for enterprise requirements. Mobile Cloud Computing is the inheritance of this concept towards mobile hand-held devices. Crowdsensing, or to be precise, Mobile Crowdsensing is the process of sharing resources from an available group of mobile handheld devices that support sharing of different resources such as data, memory and bandwidth to perform a single task for collective reasons. In this paper, we propose a framework to use Crowdsensing and perform a crowd analyzer and advisor whether the user can go to the place or not. This is an ongoing research and is a new concept to which the direction of cloud computing has shifted and is viable for more expansion in the near future.

Mapping Vineyard Leaf Area Using Mobile Terrestrial Laser Scanners: Should Rows be Scanned On-the-Go or Discontinuously Sampled?

PubMed Central

del-Moral-Martínez, Ignacio; Rosell-Polo, Joan R.; Company, Joaquim; Sanz, Ricardo; Escolà, Alexandre; Masip, Joan; Martínez-Casasnovas, José A.; Arnó, Jaume

2016-01-01

The leaf area index (LAI) is defined as the one-side leaf area per unit ground area, and is probably the most widely used index to characterize grapevine vigor. However, LAI varies spatially within vineyard plots. Mapping and quantifying this variability is very important for improving management decisions and agricultural practices. In this study, a mobile terrestrial laser scanner (MTLS) was used to map the LAI of a vineyard, and then to examine how different scanning methods (on-the-go or discontinuous systematic sampling) may affect the reliability of the resulting raster maps. The use of the MTLS allows calculating the enveloping vegetative area of the canopy, which is the sum of the leaf wall areas for both sides of the row (excluding gaps) and the projected upper area. Obtaining the enveloping areas requires scanning from both sides one meter length section along the row at each systematic sampling point. By converting the enveloping areas into LAI values, a raster map of the latter can be obtained by spatial interpolation (kriging). However, the user can opt for scanning on-the-go in a continuous way and compute 1-m LAI values along the rows, or instead, perform the scanning at discontinuous systematic sampling within the plot. An analysis of correlation between maps indicated that MTLS can be used discontinuously in specific sampling sections separated by up to 15 m along the rows. This capability significantly reduces the amount of data to be acquired at field level, the data storage capacity and the processing power of computers. PMID:26797618

Mapping Vineyard Leaf Area Using Mobile Terrestrial Laser Scanners: Should Rows be Scanned On-the-Go or Discontinuously Sampled?

PubMed

del-Moral-Martínez, Ignacio; Rosell-Polo, Joan R; Company, Joaquim; Sanz, Ricardo; Escolà, Alexandre; Masip, Joan; Martínez-Casasnovas, José A; Arnó, Jaume

2016-01-19

The leaf area index (LAI) is defined as the one-side leaf area per unit ground area, and is probably the most widely used index to characterize grapevine vigor. However, LAI varies spatially within vineyard plots. Mapping and quantifying this variability is very important for improving management decisions and agricultural practices. In this study, a mobile terrestrial laser scanner (MTLS) was used to map the LAI of a vineyard, and then to examine how different scanning methods (on-the-go or discontinuous systematic sampling) may affect the reliability of the resulting raster maps. The use of the MTLS allows calculating the enveloping vegetative area of the canopy, which is the sum of the leaf wall areas for both sides of the row (excluding gaps) and the projected upper area. Obtaining the enveloping areas requires scanning from both sides one meter length section along the row at each systematic sampling point. By converting the enveloping areas into LAI values, a raster map of the latter can be obtained by spatial interpolation (kriging). However, the user can opt for scanning on-the-go in a continuous way and compute 1-m LAI values along the rows, or instead, perform the scanning at discontinuous systematic sampling within the plot. An analysis of correlation between maps indicated that MTLS can be used discontinuously in specific sampling sections separated by up to 15 m along the rows. This capability significantly reduces the amount of data to be acquired at field level, the data storage capacity and the processing power of computers.

An Agent Based Collaborative Simplification of 3D Mesh Model

NASA Astrophysics Data System (ADS)

Wang, Li-Rong; Yu, Bo; Hagiwara, Ichiro

Large-volume mesh model faces the challenge in fast rendering and transmission by Internet. The current mesh models obtained by using three-dimensional (3D) scanning technology are usually very large in data volume. This paper develops a mobile agent based collaborative environment on the development platform of mobile-C. Communication among distributed agents includes grasping image of visualized mesh model, annotation to grasped image and instant message. Remote and collaborative simplification can be efficiently conducted by Internet.

Improved Tandem Measurement Techniques for Aerosol Particle Analysis

NASA Astrophysics Data System (ADS)

Rawat, Vivek Kumar

Non-spherical, chemically inhomogeneous (complex) nanoparticles are encountered in a number of natural and engineered environments, including combustion systems (which produces highly non-spherical aggregates), reactors used in gas-phase materials synthesis of doped or multicomponent materials, and in ambient air. These nanoparticles are often highly diverse in size, composition and shape, and hence require determination of property distribution functions for accurate characterization. This thesis focuses on development of tandem mobility-mass measurement techniques coupled with appropriate data inversion routines to facilitate measurement of two dimensional size-mass distribution functions while correcting for the non-idealities of the instruments. Chapter 1 provides the detailed background and motivation for the studies performed in this thesis. In chapter 2, the development of an inversion routine is described which is employed to determine two dimensional size-mass distribution functions from Differential Mobility Analyzer-Aerosol Particle Mass analyzer tandem measurements. Chapter 3 demonstrates the application of the two dimensional distribution function to compute cumulative mass distribution function and also evaluates the validity of this technique by comparing the calculated total mass concentrations to measured values for a variety of aerosols. In Chapter 4, this tandem measurement technique with the inversion routine is employed to analyze colloidal suspensions. Chapter 5 focuses on application of a transverse modulation ion mobility spectrometer coupled with a mass spectrometer to study the effect of vapor dopants on the mobility shifts of sub 2 nm peptide ion clusters. These mobility shifts are then compared to models based on vapor uptake theories. Finally, in Chapter 6, a conclusion of all the studies performed in this thesis is provided and future avenues of research are discussed.

More screen operation than calling: the results of observing cyclists' behaviour while using mobile phones.

PubMed

de Waard, Dick; Westerhuis, Frank; Lewis-Evans, Ben

2015-03-01

Operating a mobile telephone while riding a bicycle is fairly common practice in the Netherlands, yet it is unknown if this use is stable or increasing. As such, whether the prevalence of mobile phone use while cycling has changed over the past five years was studied via on-road observation. In addition the impact of mobile phone use on lateral position, i.e. distance from the front wheel to the curb, was also examined to see if it compared to the results seen in previous experimental studies. Bicyclists were observed at six different locations and their behaviour was scored. It was found that compared to five years ago the use of mobile phones while cycling has changed, not in frequency, but in how cyclists were operating their phones. As found in 2008, three percent of the bicyclists were observed to be operating a phone, but a shift from calling (0.7% of cyclists observed) to operating (typing, texting, 2.3% of cyclists) was found. In 2008 nearly the complete opposite usage was observed: 2.2% of the cyclists were calling and 0.6% was texting. Another finding was that effects on lateral position were similar to those seen in experimental studies in that cyclists using a phone maintained a cycling position which was further away from the curb. It was also found that when at an intersection, cyclist's operating their phone made less head movements to the right than cyclists who were just cycling. This shift from calling to screen operation, when combined with the finding related to reduced head movements at intersections, is worrying and potentially dangerous. Copyright © 2015 Elsevier Ltd. All rights reserved.

Apertureless scanning microscope probe as a detector of semiconductor laser emission

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

Dunaevskiy, Mikhail, E-mail: Mike.Dunaeffsky@mail.ioffe.ru; National Research University of Information Technologies, Mechanics and Optics; Dontsov, Anton

2015-04-27

An operating semiconductor laser has been studied using a scanning probe microscope. A shift of the resonance frequency of probe that is due to its heating by laser radiation has been analyzed. The observed shift is proportional to the absorbed radiation and can be used to measure the laser near field or its output power. A periodical dependence of the measured signal has been observed as a function of distance between the probe and the surface of the laser due to the interference of the outgoing and cantilever-reflected waves. Due to the multiple reflections resulting in the interference, the lightmore » absorption by the probe cantilever is greatly enhanced compared with a single pass case. Interaction of infrared emission of a diode laser with different probes has been studied.« less

Simultaneously measured signals in scanning probe microscopy with a needle sensor: frequency shift and tunneling current.

PubMed

Morawski, Ireneusz; Voigtländer, Bert

2010-03-01

We present combined noncontact scanning force microscopy and tunneling current images of a platinum(111) surface obtained by means of a 1 MHz quartz needle sensor. The low-frequency circuit of the tunneling current was combined with a high-frequency signal of the quartz resonator enabling full electrical operation of the sensor. The frequency shift and the tunneling current were detected simultaneously, while the feedback control loop of the topography signal was fed using one of them. In both cases, the free signal that was not connected to the feedback loop reveals proportional-integral controller errorlike behavior, which is governed by the time derivative of the topography signal. A procedure is proposed for determining the mechanical oscillation amplitude by utilizing the tunneling current also including the average tip-sample work function.

Noninvasive diagnosis of oral cancer by Stokes shift spectroscopy

NASA Astrophysics Data System (ADS)

Ebenezar, Jeyasingh; Ganesan, Singaravelu; Aruna, Prakasrao; Muralinaidu, Radhakrishnan

2014-03-01

The objective of this study is to evaluate the diagnostic potential of stokes shift (SS) spectroscopy (S3) for normal, precancer and cancerous oral lesions in vivo. The SS spectra were recorded in the 250 - 650 nm spectral range by simultaneously scanning both the excitation and emission wavelengths while keeping a fixed wavelength interval Δλ=20 nm between them. Characteristic, highly resolved peaks and significant spectral differences between normal and different pathological oral lesions observed around 300, 355, 395, and 420 nm which are attributed to tryptophan, collagen, and NADH respectively. Using S3 technique one can obtain the key fluorophores in a single scan and hence they can be targeted as a tumor markers in this study. In order to quantify the altered spectral differences between normal and different pathological oral lesions are verified by different ratio parameters.

Enhancing the blue shift of SHG signal in GaSe:B/Ce crystal

NASA Astrophysics Data System (ADS)

Karatay, Ahmet; Yuksek, Mustafa; Ertap, Hüseyin; Elmali, Ayhan; Karabulut, Mevlut

2018-02-01

The influence of Ce3+ on the wavelength of second harmonic generation (SHG) signal in boron doped GaSe crystals have been investigated. We found that by substitution of Ce3+ with B3+, SHG signal shifted to lower wavelength. In addition, the nonlinear absorption (NA) properties and ultrafast dynamics of pure, 1 at.% B3+ and 0.5 at.% B3++ 0.5 at.% Ce3+ doped GaSe crystals have been studied by open aperture Z-scan and ultrafast pump probe spectroscopy techniques. From the open aperture Z-scan experiments we observed that all of the crystals showed nonlinear absorption (NA). However, pump-probe experiments revealed that when GaSe crystal is doped, the NA signal turns into a bleaching signal with different lifetimes depending on the type and concentration of the dopant atoms.

3D WindScanner lidar measurements of wind and turbulence around wind turbines, buildings and bridges

NASA Astrophysics Data System (ADS)

Mikkelsen, T.; Sjöholm, M.; Angelou, N.; Mann, J.

2017-12-01

WindScanner is a distributed research infrastructure developed at DTU with the participation of a number of European countries. The research infrastructure consists of a mobile technically advanced facility for remote measurement of wind and turbulence in 3D. The WindScanners provide coordinated measurements of the entire wind and turbulence fields, of all three wind components scanned in 3D space. Although primarily developed for research related to on- and offshore wind turbines and wind farms, the facility is also well suited for scanning turbulent wind fields around buildings, bridges, aviation structures and of flow in urban environments. The mobile WindScanner facility enables 3D scanning of wind and turbulence fields in full scale within the atmospheric boundary layer at ranges from 10 meters to 5 (10) kilometers. Measurements of turbulent coherent structures are applied for investigation of flow pattern and dynamical loads from turbines, building structures and bridges and in relation to optimization of the location of, for example, wind farms and suspension bridges. This paper presents our achievements to date and reviews briefly the state-of-the-art of the WindScanner measurement technology with examples of uses for wind engineering applications.

Nonlinear Pressure-Flow Relationship Is Able to Detect Asymmetry of Brain Blood Circulation Associated with Midline Shift

PubMed Central

Lo, Men-Tzung; Peng, C.K.; Novak, Vera; Schmidt, Eric A.; Kumar, Ajay; Czosnyka, Marek

2009-01-01

Abstract Reliable and noninvasive assessment of cerebral blood flow regulation is a major challenge in acute care monitoring. This study assessed dynamics of flow regulation and its relationship to asymmetry of initial computed tomography (CT) scan using multimodal pressure flow (MMPF) analysis. Data of 27 patients (38 ± 15 years old) with traumatic brain injury (TBI) were analyzed. Patients were selected from bigger cohort according to criteria of having midline shift on initial CT scan and intact skull (no craniotomy or bone flap). The MMPF analysis was used to extract the oscillations in cerebral perfusion pressure (CPP) and blood flow velocity (BFV) signals at frequency of artificial ventilation, and to calculate the instantaneous phase difference between CPP and BFV oscillations. Mean CPP-BFV phase difference was used to quantify pressure and flow relationship. The TBI subjects had smaller mean BP-BFV phase shifts (left, 8.7 ± 9.6; right 10.2 ± 8.3 MCAs, mean ± SD) than values previously obtained in healthy subjects (left, 37.3 ± 7.6 degrees; right, 38.0 ± 8.9 degrees; p < 0.0001), suggesting impaired blood flow regulation after TBI. The difference in phase shift between CPP and BFV in the left and right side was strongly correlated to the midline shift (R = 0.78; p < 0.0001). These findings indicate that the MMPF method allows reliable assessment of alterations in pressure and flow relationship after TBI. Moreover, mean pressure-flow phase shift is sensitive to the displacement of midline of the brain, and may potentially serve as a marker of asymmetry of cerebral autoregulation. PMID:19196074

Uncertainty propagation using the Monte Carlo method in the measurement of airborne particle size distribution with a scanning mobility particle sizer

NASA Astrophysics Data System (ADS)

Coquelin, L.; Le Brusquet, L.; Fischer, N.; Gensdarmes, F.; Motzkus, C.; Mace, T.; Fleury, G.

2018-05-01

A scanning mobility particle sizer (SMPS) is a high resolution nanoparticle sizing system that is widely used as the standard method to measure airborne particle size distributions (PSD) in the size range 1 nm–1 μm. This paper addresses the problem to assess the uncertainty associated with PSD when a differential mobility analyzer (DMA) operates under scanning mode. The sources of uncertainty are described and then modeled either through experiments or knowledge extracted from the literature. Special care is brought to model the physics and to account for competing theories. Indeed, it appears that the modeling errors resulting from approximations of the physics can largely affect the final estimate of this indirect measurement, especially for quantities that are not measured during day-to-day experiments. The Monte Carlo method is used to compute the uncertainty associated with PSD. The method is tested against real data sets that are monosize polystyrene latex spheres (PSL) with nominal diameters of 100 nm, 200 nm and 450 nm. The median diameters and associated standard uncertainty of the aerosol particles are estimated as 101.22 nm  ±  0.18 nm, 204.39 nm  ±  1.71 nm and 443.87 nm  ±  1.52 nm with the new approach. Other statistical parameters, such as the mean diameter, the mode and the geometric mean and associated standard uncertainty, are also computed. These results are then compared with the results obtained by SMPS embedded software.

Automatic Feature Detection, Description and Matching from Mobile Laser Scanning Data and Aerial Imagery

NASA Astrophysics Data System (ADS)

Hussnain, Zille; Oude Elberink, Sander; Vosselman, George

2016-06-01

In mobile laser scanning systems, the platform's position is measured by GNSS and IMU, which is often not reliable in urban areas. Consequently, derived Mobile Laser Scanning Point Cloud (MLSPC) lacks expected positioning reliability and accuracy. Many of the current solutions are either semi-automatic or unable to achieve pixel level accuracy. We propose an automatic feature extraction method which involves utilizing corresponding aerial images as a reference data set. The proposed method comprise three steps; image feature detection, description and matching between corresponding patches of nadir aerial and MLSPC ortho images. In the data pre-processing step the MLSPC is patch-wise cropped and converted to ortho images. Furthermore, each aerial image patch covering the area of the corresponding MLSPC patch is also cropped from the aerial image. For feature detection, we implemented an adaptive variant of Harris-operator to automatically detect corner feature points on the vertices of road markings. In feature description phase, we used the LATCH binary descriptor, which is robust to data from different sensors. For descriptor matching, we developed an outlier filtering technique, which exploits the arrangements of relative Euclidean-distances and angles between corresponding sets of feature points. We found that the positioning accuracy of the computed correspondence has achieved the pixel level accuracy, where the image resolution is 12cm. Furthermore, the developed approach is reliable when enough road markings are available in the data sets. We conclude that, in urban areas, the developed approach can reliably extract features necessary to improve the MLSPC accuracy to pixel level.

Effect of Phase Shift from Corals to Zoantharia on Reef Fish Assemblages

PubMed Central

Cruz, Igor C. S.; Loiola, Miguel; Albuquerque, Tiago; Reis, Rodrigo; de Anchieta C. C. Nunes, José; Reimer, James D.; Mizuyama, Masaru; Kikuchi, Ruy K. P.; Creed, Joel C.

2015-01-01

Consequences of reef phase shifts on fish communities remain poorly understood. Studies on the causes, effects and consequences of phase shifts on reef fish communities have only been considered for coral-to-macroalgae shifts. Therefore, there is a large information gap regarding the consequences of novel phase shifts and how these kinds of phase shifts impact on fish assemblages. This study aimed to compare the fish assemblages on reefs under normal conditions (relatively high cover of corals) to those which have shifted to a dominance of the zoantharian Palythoa cf. variabilis on coral reefs in Todos os Santos Bay (TSB), Brazilian eastern coast. We examined eight reefs, where we estimated cover of corals and P. cf. variabilis and coral reef fish richness, abundance and body size. Fish richness differed significantly between normal reefs (48 species) and phase-shift reefs (38 species), a 20% reduction in species. However there was no difference in fish abundance between normal and phase shift reefs. One fish species, Chaetodon striatus, was significantly less abundant on normal reefs. The differences in fish assemblages between different reef phases was due to differences in trophic groups of fish; on normal reefs carnivorous fishes were more abundant, while on phase shift reefs mobile invertivores dominated. PMID:25629532

The effects of shift work and time of day on fine motor control during handwriting.

PubMed

Hölzle, Patricia; Hermsdörfer, Joachim; Vetter, Céline

2014-01-01

Handwriting is an elaborate and highly automatised skill relying on fine motor control. In laboratory conditions handwriting kinematics are modulated by the time of day. This study investigated handwriting kinematics in a rotational shift system and assessed whether similar time of day fluctuations at the work place can be observed. Handwriting performance was measured in two tasks of different levels of complexity in 34 shift workers across morning (6:00-14:00), evening (14:00-22:00) and night shifts (22:00-6:00). Participants were tested during all three shifts in 2-h intervals with mobile testing devices. We calculated average velocity, script size and writing frequency to quantify handwriting kinematics and fluency. Average velocity and script size were significantly affected by the shift work schedule with the worst performance during morning shifts and the best performance during evening shifts. Our data are of high economic relevance as fine motor skills are indispensable for accurate and effective production at the work place. Handwriting is one of the most complex fine motor skills in humans, which is frequently performed in daily life. In this study, we tested handwriting repeatedly at the work place in a rotational shift system. We found slower handwriting velocity and reduced script size during morning shifts.

Structural and dynamical trends in alkali-metal silanides characterized by neutron-scattering methods

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

Tang, Wan Si; Dimitrievska, Mirjana; Chotard, Jean -Noel

Structural, vibrational, and dynamical properties of the mono- and mixed-alkali silanides (MSiH 3, where M = K, Rb, Cs, K 0.5Rb 0.5, K 0.5Cs 0.5, and Rb 0.5Cs 0.5) were investigated by various neutron experiments, including neutron powder diffraction (NPD), neutron vibrational spectroscopy (NVS), neutron-scattering fixed-window scans (FWSs), and quasielastic neutron scattering (QENS) measurements. Structural characterization showed that the mixed compounds exhibit disordered (α) and ordered (β) phases for temperatures above and below about 200–250 K, respectively, in agreement with their monoalkali correspondents. Vibrational and dynamical properties are strongly influenced by the cation environment; in particular, there is a redmore » shift in the band energies of the librational and bending modes with increasing lattice size as a result of changes in the bond lengths and force constants. Additionally, slightly broader spectral features are observed in the case of the mixed compounds, indicating the presence of structural disorder caused by the random distribution of the alkali-metal cations within the lattice. FWS measurements upon heating showed that there is a large increase in reorientational mobility as the systems go through the order–disorder (β–α) phase transition, and measurements upon cooling of the α-phase revealed the known strong hysteresis for reversion back to the β-phase. Interestingly, at a given temperature, among the different alkali silanide compounds, the relative reorientational mobilities of the SiH 3 – anions in the α- and β-phases tended to decrease and increase, respectively, with increasing alkali-metal mass. Lastly, this dynamical result might provide some insights concerning the enthalpy–entropy compensation effect previously observed for these potentially promising hydrogen storage materials.« less

Thermal behavior of H-aggregate in a mixed Langmuir-Blodgett film of merocyanine dye, arachidic acid, and n-octadecane ternary system investigated by UV-visible and IR absorption spectroscopy.

PubMed

Hirano, Yoshiaki; Tateno, Shinsuke; Yamashita, Yoshihide; Ozaki, Yukihiro

2008-11-13

We have investigated the thermal behavior of H-aggregate in a mixed Langmuir-Blodgett (LB) film of the merocyanine dye (MS18)-arachidic acid (C20)- n-octadecane (AL18) ternary system by means of UV-visible and IR absorption spectroscopy in the range from 25 to 250 degrees C with a continuous scan. The results of both UV-visible and IR spectra indicate that the temperature-dependent variation in MS 18 aggregation state is linked not only with the degree of intramolecular charge transfer and the behavior of packing, orientation, conformation, and thermal mobility of the MS18 hydrocarbon chain but also with the presence and absence of AL18. The H-aggregate dissociates from 25 up to 50 degrees C, which is caused by the AL18 evaporation from the mixed LB film and the increment of thermal mobility of the MS18 hydrocarbon chain. From 110 to 160 degrees C, blue-shifted bands, attributed to the oligomeric MS18 aggregation, appear near 515 nm in the MS18-C 20-AL18 ternary system as well. The temperature at which the 515 nm band occurs is identical for both present ternary system and previously investigated MS18-deuterated arachidic acid (C20- d) binary system, and it is in good agreement with the melting point (110 degrees C) of cadmium arachidate (CdC20). Therefore, it is indicated that the driving force which induces the 515 nm band comes from the melting phenomenon of CdC20 molecules which are phase-separated from MS 18 molecules in as-deposited LB films.

Oxygen "getter" effects on microstructure and carrier transport in low temperature combustion-processed a-InXZnO (X = Ga, Sc, Y, La) transistors.

PubMed

Hennek, Jonathan W; Smith, Jeremy; Yan, Aiming; Kim, Myung-Gil; Zhao, Wei; Dravid, Vinayak P; Facchetti, Antonio; Marks, Tobin J

2013-07-24

In oxide semiconductors, such as those based on indium zinc oxide (IXZO), a strong oxygen binding metal ion ("oxygen getter"), X, functions to control O vacancies and enhance lattice formation, hence tune carrier concentration and transport properties. Here we systematically study, in the IXZO series, the role of X = Ga(3+) versus the progression X = Sc(3+) → Y(3+) → La(3+), having similar chemical characteristics but increasing ionic radii. IXZO films are prepared from solution over broad composition ranges for the first time via low-temperature combustion synthesis. The films are characterized via thermal analysis of the precursor solutions, grazing incidence angle X-ray diffraction (GIAXRD), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and scanning transmission electron microscopy (STEM) with high angle annular dark field (HAADF) imaging. Excellent thin-film transistor (TFT) performance is achieved for all X, with optimal compositions after 300 °C processing exhibiting electron mobilities of 5.4, 2.6, 2.4, and 1.8 cm(2) V(-1) s(-1) for Ga(3+), Sc(3+), Y(3+), and La(3+), respectively, and with I(on)/I(off) = 10(7)-10(8). Analysis of the IXZO TFT positive bias stress response shows X = Ga(3+) to be superior with mobilities (μ) retaining >95% of the prestress values and threshold voltage shifts (ΔV(T)) of <1.6 V, versus <85% μ retention and ΔV(T) ≈ 20 V for the other trivalent ions. Detailed microstructural analysis indicates that Ga(3+) most effectively promotes oxide lattice formation. We conclude that the metal oxide lattice formation enthalpy (ΔH(L)) and metal ionic radius are the best predictors of IXZO oxygen getter efficacy.

Structural and dynamical trends in alkali-metal silanides characterized by neutron-scattering methods

DOE PAGES

Tang, Wan Si; Dimitrievska, Mirjana; Chotard, Jean -Noel; ...

2016-09-02

Structural, vibrational, and dynamical properties of the mono- and mixed-alkali silanides (MSiH 3, where M = K, Rb, Cs, K 0.5Rb 0.5, K 0.5Cs 0.5, and Rb 0.5Cs 0.5) were investigated by various neutron experiments, including neutron powder diffraction (NPD), neutron vibrational spectroscopy (NVS), neutron-scattering fixed-window scans (FWSs), and quasielastic neutron scattering (QENS) measurements. Structural characterization showed that the mixed compounds exhibit disordered (α) and ordered (β) phases for temperatures above and below about 200–250 K, respectively, in agreement with their monoalkali correspondents. Vibrational and dynamical properties are strongly influenced by the cation environment; in particular, there is a redmore » shift in the band energies of the librational and bending modes with increasing lattice size as a result of changes in the bond lengths and force constants. Additionally, slightly broader spectral features are observed in the case of the mixed compounds, indicating the presence of structural disorder caused by the random distribution of the alkali-metal cations within the lattice. FWS measurements upon heating showed that there is a large increase in reorientational mobility as the systems go through the order–disorder (β–α) phase transition, and measurements upon cooling of the α-phase revealed the known strong hysteresis for reversion back to the β-phase. Interestingly, at a given temperature, among the different alkali silanide compounds, the relative reorientational mobilities of the SiH 3 – anions in the α- and β-phases tended to decrease and increase, respectively, with increasing alkali-metal mass. Lastly, this dynamical result might provide some insights concerning the enthalpy–entropy compensation effect previously observed for these potentially promising hydrogen storage materials.« less

Geometric design practices for European roads

DOT National Transportation Integrated Search

2001-06-01

The objective of the scanning tour was to review and document European procedures and practices in roadway geometric design and context-sensitive design, in which a balance is sought between safety and mobility needs and community interests. The U.S....

Understanding Mobile Apps

MedlinePlus

... share personal information let your kids spend real money — even if the app is free include ads link to social media What’s more, ... Money & Credit Homes & Mortgages Health & Fitness Jobs & Making ... Security "Free" Security Scans Computer Security Disposing of Old Computers ...

Modular scanning FCS quantifies receptor-ligand interactions in living multicellular organisms.

PubMed

Ries, Jonas; Yu, Shuizi Rachel; Burkhardt, Markus; Brand, Michael; Schwille, Petra

2009-09-01

Analysis of receptor-ligand interactions in vivo is key to biology but poses a considerable challenge to quantitative microscopy. Here we combine static-volume, two-focus and dual-color scanning fluorescence correlation spectroscopy to solve this task at cellular resolution in complex biological environments. We quantified the mobility of fibroblast growth factor receptors Fgfr1 and Fgfr4 in cell membranes of living zebrafish embryos and determined their in vivo binding affinities to their ligand Fgf8.

Tracking Human Mobility Using WiFi Signals

PubMed Central

Sapiezynski, Piotr; Stopczynski, Arkadiusz; Gatej, Radu; Lehmann, Sune

2015-01-01

We study six months of human mobility data, including WiFi and GPS traces recorded with high temporal resolution, and find that time series of WiFi scans contain a strong latent location signal. In fact, due to inherent stability and low entropy of human mobility, it is possible to assign location to WiFi access points based on a very small number of GPS samples and then use these access points as location beacons. Using just one GPS observation per day per person allows us to estimate the location of, and subsequently use, WiFi access points to account for 80% of mobility across a population. These results reveal a great opportunity for using ubiquitous WiFi routers for high-resolution outdoor positioning, but also significant privacy implications of such side-channel location tracking. PMID:26132115

Network-Centric Operations Support: Lessons Learned, Status, and Way-Ahead

DTIC Science & Technology

2014-06-01

34 Information Sharing Environment (ISE) Presentation, Enterprise Architecture Conference, 2011 (http://goveaconference.com/Events/2011/Sessions/ Tuesday ...cgi-bin/GetTRDoc?AD=ADA525312) [35] Morris , Michael, et al. Widget and Mobile Technologies a Forcing Function for Acquisition Change: Paradigm Shift

The Case for Place

ERIC Educational Resources Information Center

Thomas, Lisa Carlucci

2012-01-01

Bookstores, record stores, libraries, Facebook: these places--both physical and virtual--demonstrate an established and essential purpose as centers of community, expertise, convenience, immediacy, and respect. Yet as digital, mobile, and social shifts continue to transform culture and interactions, these spaces and places transform, too.…

Parochialism and Intercourse: Metaphors for Mobility.

ERIC Educational Resources Information Center

Edwards, John

1994-01-01

Discusses tensions resulting from dichotomies existing between "smaller" languages and those of wider communications. It is suggested that there are four recurring approaches for dealing with this tension: communicative language shift, defense of the more threatened variety, "localization" of the stronger language (for example,…

Automated measurement of uptake in cerebellum, liver, and aortic arch in full-body FDG PET/CT scans.

PubMed

Bauer, Christian; Sun, Shanhui; Sun, Wenqing; Otis, Justin; Wallace, Audrey; Smith, Brian J; Sunderland, John J; Graham, Michael M; Sonka, Milan; Buatti, John M; Beichel, Reinhard R

2012-06-01

The purpose of this work was to develop and validate fully automated methods for uptake measurement of cerebellum, liver, and aortic arch in full-body PET/CT scans. Such measurements are of interest in the context of uptake normalization for quantitative assessment of metabolic activity and/or automated image quality control. Cerebellum, liver, and aortic arch regions were segmented with different automated approaches. Cerebella were segmented in PET volumes by means of a robust active shape model (ASM) based method. For liver segmentation, a largest possible hyperellipsoid was fitted to the liver in PET scans. The aortic arch was first segmented in CT images of a PET/CT scan by a tubular structure analysis approach, and the segmented result was then mapped to the corresponding PET scan. For each of the segmented structures, the average standardized uptake value (SUV) was calculated. To generate an independent reference standard for method validation, expert image analysts were asked to segment several cross sections of each of the three structures in 134 F-18 fluorodeoxyglucose (FDG) PET/CT scans. For each case, the true average SUV was estimated by utilizing statistical models and served as the independent reference standard. For automated aorta and liver SUV measurements, no statistically significant scale or shift differences were observed between automated results and the independent standard. In the case of the cerebellum, the scale and shift were not significantly different, if measured in the same cross sections that were utilized for generating the reference. In contrast, automated results were scaled 5% lower on average although not shifted, if FDG uptake was calculated from the whole segmented cerebellum volume. The estimated reduction in total SUV measurement error ranged between 54.7% and 99.2%, and the reduction was found to be statistically significant for cerebellum and aortic arch. With the proposed methods, the authors have demonstrated that automated SUV uptake measurements in cerebellum, liver, and aortic arch agree with expert-defined independent standards. The proposed methods were found to be accurate and showed less intra- and interobserver variability, compared to manual analysis. The approach provides an alternative to manual uptake quantification, which is time-consuming. Such an approach will be important for application of quantitative PET imaging to large scale clinical trials. © 2012 American Association of Physicists in Medicine.

Functional improvements following the use of the NVT Vision Rehabilitation program for patients with hemianopia following stroke.

PubMed

Hayes, Allison; Chen, Celia S; Clarke, Gayle; Thompson, Annette

2012-01-01

The incidence of visual deficits following stroke ranges from 20%-68% and has significant impact on activities of daily living. The NVT system is a compensatory visual scanning training program that consists of combined static and mobility training and transfer to activities of daily living. The study aims to evaluate functional changes following the NVT program for people who have homonymous hemianopia (HH) following stroke. Interventional case series of 13 consecutive participants with HH undergoing NVT vision rehabilitation. The primary outcome measure was the number of targets missed on a standardized Mobility Assessment Course (MAC). Other outcome measures included assessment of visual scanning, vision specific Quality of Life questionnaires and reading performance. The average number of targets (sd) missed on the MAC course was 39.6 ± 20.9% before intervention, 27.5 ± 16.3% immediately post intervention and 20.8 ± 15.5% at 3 months post rehabilitation. The study showed a statistically significant trend in improvement in mobility related subscales of National Eye Institute Visual Function Questionnaire-NEI VFQ-25 (p=0.003) and the Veteran Affairs Low Vision Visual Function Questionnaire-VA LVFQ-48 (p=0.036) at 3 months post rehabilitation. The NVT intervention resulted in functional improvements in mobility post rehabilitation. The NVT training showed improvement in vision specific quality of life. There is a need for standardised vision therapy intervention, in conjunction with existing rehabilitation services, for patients with stroke and traumatic brain injury.

Data on the calcium-induced mobility shift of myristoylated and non-myristoylated forms of neurocalcin delta.

PubMed

Viviano, Jeffrey; Krishnan, Anuradha; Wu, Hao; Venkataraman, Venkat

2016-06-01

This data article presents the differences observed between the myristoylated and non-myristoylated forms of the neuronal calcium sensor protein, neurocalcin delta (NCALD). Analysis of the myristoylated and non-myristoylated versions of the protein by mass spectrometry provided difference in mass values consistent with addition of myristoyl group. In the presence of calcium, mobility retardation was observed upon electrophoresis of the protein in native gels. The retardation was dose-dependent and was exhibited by both the myristoylated and non-myristoylated forms of the protein.

Methanogenesis-induced pH–Eh shifts drives aqueous metal(loid) mobility in sulfide mineral systems under CO2 enriched conditions

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

Harvey, Omar R.; Qafoku, Nikolla; Cantrell, Kirk J.

2016-01-15

Accounting for microbially-mediated CO2 transformation is pivotal to assessing geochemical implications for elevated CO2 in subsurface environments. A series of batch-reactor experiments were conducted to decipher links between autotrophic methanogenesis, CO2 dynamics and aqueous Fe, As and Pb concentrations in the presence of sulfide minerals. Microbially-mediated solubility-trapping followed by pseudo-first order reduction of HCO3- to CH4 (k’ = 0.28-0.59 d-1) accounted for 95% of the CO2 loss from methanogenic experiments. Bicarbonate-to-methane reduction was pivotal in the mitigation of CO2-induced acidity (~1 pH unit) and enhancement of reducing conditions (Eh change from -0.215 to -0.332V ). Methanogenesis-associated shifts in pH-Eh valuesmore » showed no significant effect on aqueous Pb but favored, 1) increased aqueous As as a result of microbially-mediated dissolution of arsenopyrite and 2) decreased aqueous Fe due to mineral-trapping of CO2-mobilized Fe as Fe-carbonate. Its order of occurrence (and magnitude), relative to solubility- and mineral-trapping, highlighted the potential for autotrophic methanogenesis to modulate both carbon sequestration and contaminant mobility in CO2-impacted subsurface environments.« less

Three-dimensional rotational angiography of the left atrium and the oesophagus: the short-term mobility of the oesophagus and the stability of the fused three-dimensional model of the left atrium and the oesophagus during catheter ablation for atrial fibrillation.

PubMed

Starek, Zdenek; Lehar, Frantisek; Jez, Jiri; Scurek, Martin; Wolf, Jiri; Kulik, Tomas; Zbankova, Alena; Novak, Miroslav

2017-08-01

The objective of this study was to evaluate the mobility of the oesophagus and the stability of the three-dimensional (3D) model of the oesophagus using 3D rotational angiography (3DRA) of the left atrium (LA) and the oesophagus, fused with live fluoroscopy during catheter ablation for atrial fibrillation. From March 2015 to September 2015, 3DRA of the LA and the oesophagus was performed in 33 patients before catheter ablation for atrial fibrillation. Control contrast oesophagography was performed every 30 min. The positions of the oesophagograms and the 3D model of the LA and the oesophagus were repeatedly measured and compared with the spine. The average shift of the oesophagus ranged from 2.7 ± 2.2 to 5.0 ± 3.5 mm. The average real-time oesophageal shift ranged from 2.7 ± 2.2 to 3.8 ± 3.4 mm. No significant shift was detected until the 90th minute of the procedure. The average shift of the 3D model of the LA and the oesophagus ranged from 1.4 ± 1.8 to 3.3 ± 3.0 mm (right-left direction) and from 0.9 ± 1.2 to 2.2 ± 1.3 mm (craniocaudal direction). During the 2 h procedure, there were no significant shifts of the model. During catheter ablation for atrial fibrillation, there is no significant change in the position of the oesophagus until the 90th minute of the procedure and no significant shift in the 3D model of the LA and the oesophagus. The 3D model of the oesophagus reliably depicts the position of the oesophagus during the entire procedure. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Photonic crystal fibre enables short-wavelength two-photon laser scanning fluorescence microscopy with fura-2

NASA Astrophysics Data System (ADS)

McConnell, Gail; Riis, Erling

2004-10-01

We report on a novel and compact reliable laser source capable of short-wavelength two-photon laser scanning fluorescence microscopy based on soliton self-frequency shift effects in photonic crystal fibre. We demonstrate the function of the system by performing two-photon microscopy of smooth muscle cells and cardiac myocytes from the rat pulmonary vein and Chinese hamster ovary cells loaded with the fluorescent calcium indicator fura-2/AM.

Direct Comparison of Respiration-Correlated Four-Dimensional Magnetic Resonance Imaging Reconstructed Using Concurrent Internal Navigator and External Bellows.

PubMed

Li, Guang; Wei, Jie; Olek, Devin; Kadbi, Mo; Tyagi, Neelam; Zakian, Kristen; Mechalakos, James; Deasy, Joseph O; Hunt, Margie

2017-03-01

To compare the image quality of amplitude-binned 4-dimensional magnetic resonance imaging (4DMRI) reconstructed using 2 concurrent respiratory (navigator and bellows) waveforms. A prospective, respiratory-correlated 4DMRI scanning program was used to acquire T2-weighted single-breath 4DMRI images with internal navigator and external bellows. After a 10-second training waveform of a surrogate signal, 2-dimensional MRI acquisition was triggered at a level (bin) and anatomic location (slice) until the bin-slice table was completed for 4DMRI reconstruction. The bellows signal was always collected, even when the navigator trigger was used, to retrospectively reconstruct a bellows-rebinned 4DMRI. Ten volunteers participated in this institutional review board-approved 4DMRI study. Four scans were acquired for each subject, including coronal and sagittal scans triggered by either navigator or bellows, and 6 4DMRI images (navigator-triggered, bellows-rebinned, and bellows-triggered) were reconstructed. The simultaneously acquired waveforms and resulting 4DMRI quality were compared using signal correlation, bin/phase shift, and binning motion artifacts. The consecutive bellows-triggered 4DMRI scan was used for indirect comparison. Correlation coefficients between the navigator and bellows signals were found to be patient-specific and inhalation-/exhalation-dependent, ranging from 0.1 to 0.9 because of breathing irregularities (>50% scans) and commonly observed bin/phase shifts (-1.1 ± 0.6 bin) in both 1-dimensional waveforms and diaphragm motion extracted from 4D images. Navigator-triggered 4DMRI contained many fewer binning motion artifacts at the diaphragm than did the bellows-rebinned and bellows-triggered 4DMRI scans. Coronal scans were faster than sagittal scans because of the fewer slices and higher achievable acceleration factors. Navigator-triggered 4DMRI contains substantially fewer binning motion artifacts than bellows-rebinned and bellows-triggered 4DMRI, primarily owing to the deviation of the external from the internal surrogate. The present study compared 2 concurrent surrogates during the same 4DMRI scan and their resulting 4DMRI quality. The navigator-triggered 4DMRI scanning protocol should be preferred to the bellows-based, especially for coronal scans, for clinical respiratory motion simulation. Copyright © 2016 Elsevier Inc. All rights reserved.

Understanding The Neural Mechanisms Involved In Sensory Control Of Voice Production

PubMed Central

Parkinson, Amy L.; Flagmeier, Sabina G.; Manes, Jordan L.; Larson, Charles R.; Rogers, Bill; Robin, Donald A.

2012-01-01

Auditory feedback is important for the control of voice fundamental frequency (F0). In the present study we used neuroimaging to identify regions of the brain responsible for sensory control of the voice. We used a pitch-shift paradigm where subjects respond to an alteration, or shift, of voice pitch auditory feedback with a reflexive change in F0. To determine the neural substrates involved in these audio-vocal responses, subjects underwent fMRI scanning while vocalizing with or without pitch-shifted feedback. The comparison of shifted and unshifted vocalization revealed activation bilaterally in the superior temporal gyrus (STG) in response to the pitch shifted feedback. We hypothesize that the STG activity is related to error detection by auditory error cells located in the superior temporal cortex and efference copy mechanisms whereby this region is responsible for the coding of a mismatch between actual and predicted voice F0. PMID:22406500

Probing the limits of the rigid-intensity-shift model in differential-phase-contrast scanning transmission electron microscopy

NASA Astrophysics Data System (ADS)

Clark, L.; Brown, H. G.; Paganin, D. M.; Morgan, M. J.; Matsumoto, T.; Shibata, N.; Petersen, T. C.; Findlay, S. D.

2018-04-01

The rigid-intensity-shift model of differential-phase-contrast imaging assumes that the phase gradient imposed on the transmitted probe by the sample causes the diffraction pattern intensity to shift rigidly by an amount proportional to that phase gradient. This behavior is seldom realized exactly in practice. Through a combination of experimental results, analytical modeling and numerical calculations, using as case studies electron microscope imaging of the built-in electric field in a p-n junction and nanoscale domains in a magnetic alloy, we explore the breakdown of rigid-intensity-shift behavior and how this depends on the magnitude of the phase gradient and the relative scale of features in the phase profile and the probe size. We present guidelines as to when the rigid-intensity-shift model can be applied for quantitative phase reconstruction using segmented detectors, and propose probe-shaping strategies to further improve the accuracy.

Cd Mobility in Anoxic Fe-Mineral-Rich Environments - Potential Use of Fe(III)-Reducing Bacteria in Soil Remediation

NASA Astrophysics Data System (ADS)

Muehe, E. M.; Adaktylou, I. J.; Obst, M.; Schröder, C.; Behrens, S.; Hitchcock, A. P.; Tylsizczak, T.; Michel, F. M.; Krämer, U.; Kappler, A.

2014-12-01

Agricultural soils are increasingly burdened with heavy metals such as Cd from industrial sources and impure fertilizers. Metal contaminants enter the food chain via plant uptake from soil and negatively affect human and environmental health. New remediation approaches are needed to lower soil metal contents. To apply these remediation techniques successfully, it is necessary to understand how soil microbes and minerals interact with toxic metals. Here we show that microbial Fe(III) reduction initially mobilizes Cd before its immobilization under anoxic conditions. To study how microbial Fe(III) reduction influences Cd mobility, we isolated a new Cd-tolerant, Fe(III)-reducing Geobacter sp. from a heavily Cd-contaminated soil. In lab experiments, this Geobacter strain first mobilized Cd from Cd-loaded Fe(III) hydroxides followed by precipitation of Cd-bearing mineral phases. Using Mössbauer spectroscopy and scanning electron microscopy, the original and newly formed Cd-containing Fe(II) and Fe(III) mineral phases, including Cd-Fe-carbonates, Fe-phosphates and Fe-(oxyhydr)oxides, were identified and characterized. Using energy-dispersive X-ray spectroscopy and synchrotron-based scanning transmission X-ray microscopy, Cd was mapped in the Fe(II) mineral aggregates formed during microbial Fe(III) reduction. Microbial Fe(III) reduction mobilizes Cd prior to its precipitation in Cd-bearing mineral phases. The mobilized Cd could be taken up by phytoremediating plants, resulting in a net removal of Cd from contaminated sites. Alternatively, Cd precipitation could reduce Cd bioavailability in the environment, causing less toxic effects to crops and soil microbiota. However, the stability and thus bioavailability of these newly formed Fe-Cd mineral phases needs to be assessed thoroughly. Whether phytoremediation or immobilization of Cd in a mineral with reduced Cd bioavailability are feasible mechanisms to reduce toxic effects of Cd in the environment remains to be determined.

Laser-Camera Vision Sensing for Spacecraft Mobile Robot Navigation

NASA Technical Reports Server (NTRS)

Maluf, David A.; Khalil, Ahmad S.; Dorais, Gregory A.; Gawdiak, Yuri

2002-01-01

The advent of spacecraft mobile robots-free-flyng sensor platforms and communications devices intended to accompany astronauts or remotely operate on space missions both inside and outside of a spacecraft-has demanded the development of a simple and effective navigation schema. One such system under exploration involves the use of a laser-camera arrangement to predict relative positioning of the mobile robot. By projecting laser beams from the robot, a 3D reference frame can be introduced. Thus, as the robot shifts in position, the position reference frame produced by the laser images is correspondingly altered. Using normalization and camera registration techniques presented in this paper, the relative translation and rotation of the robot in 3D are determined from these reference frame transformations.

Influence of OPD in wavelength-shifting interferometry

NASA Astrophysics Data System (ADS)

Wang, Hongjun; Tian, Ailing; Liu, Bingcai; Dang, Juanjuan

2009-12-01

Phase-shifting interferometry is a powerful tool for high accuracy optical measurement. It operates by change the optical path length in the reference arm or test arm. This method practices by move optical device. So it has much problem when the optical device is very large and heavy. For solve this problem, the wavelength-shifting interferometry was put forwarded. In wavelength-shifting interferometry, the phase shifting angle was achieved by change the wavelength of optical source. The phase shifting angle was decided by wavelength and OPD (Optical Path Difference) between test and reference wavefront. So the OPD is an important factor to measure results. But in measurement, because the positional error and profile error of under testing optical element is exist, the phase shifting angle is different in different test point when wavelength scanning, it will introduce phase shifting angle error, so it will introduce optical surface measure error. For analysis influence of OPD on optical surface error, the relation between surface error and OPD was researched. By simulation, the relation between phase shifting error and OPD was established. By analysis, the error compensation method was put forward. After error compensation, the measure results can be improved to great extend.

Influence of OPD in wavelength-shifting interferometry

NASA Astrophysics Data System (ADS)

Wang, Hongjun; Tian, Ailing; Liu, Bingcai; Dang, Juanjuan

2010-03-01

Phase-shifting interferometry is a powerful tool for high accuracy optical measurement. It operates by change the optical path length in the reference arm or test arm. This method practices by move optical device. So it has much problem when the optical device is very large and heavy. For solve this problem, the wavelength-shifting interferometry was put forwarded. In wavelength-shifting interferometry, the phase shifting angle was achieved by change the wavelength of optical source. The phase shifting angle was decided by wavelength and OPD (Optical Path Difference) between test and reference wavefront. So the OPD is an important factor to measure results. But in measurement, because the positional error and profile error of under testing optical element is exist, the phase shifting angle is different in different test point when wavelength scanning, it will introduce phase shifting angle error, so it will introduce optical surface measure error. For analysis influence of OPD on optical surface error, the relation between surface error and OPD was researched. By simulation, the relation between phase shifting error and OPD was established. By analysis, the error compensation method was put forward. After error compensation, the measure results can be improved to great extend.

Animal-Free Chemical Safety Assessment

PubMed Central

Loizou, George D.

2016-01-01

The exponential growth of the Internet of Things and the global popularity and remarkable decline in cost of the mobile phone is driving the digital transformation of medical practice. The rapidly maturing digital, non-medical world of mobile (wireless) devices, cloud computing and social networking is coalescing with the emerging digital medical world of omics data, biosensors and advanced imaging which offers the increasingly realistic prospect of personalized medicine. Described as a potential “seismic” shift from the current “healthcare” model to a “wellness” paradigm that is predictive, preventative, personalized and participatory, this change is based on the development of increasingly sophisticated biosensors which can track and measure key biochemical variables in people. Additional key drivers in this shift are metabolomic and proteomic signatures, which are increasingly being reported as pre-symptomatic, diagnostic and prognostic of toxicity and disease. These advancements also have profound implications for toxicological evaluation and safety assessment of pharmaceuticals and environmental chemicals. An approach based primarily on human in vivo and high-throughput in vitro human cell-line data is a distinct possibility. This would transform current chemical safety assessment practice which operates in a human “data poor” to a human “data rich” environment. This could also lead to a seismic shift from the current animal-based to an animal-free chemical safety assessment paradigm. PMID:27493630

Forecasted range shifts of arid-land fishes in response to climate change

USGS Publications Warehouse

Whitney, James E.; Whittier, Joanna B.; Paukert, Craig P.; Olden, Julian D.; Strecker, Angela L.

2017-01-01

Climate change is poised to alter the distributional limits, center, and size of many species. Traits may influence different aspects of range shifts, with trophic generality facilitating shifts at the leading edge, and greater thermal tolerance limiting contractions at the trailing edge. The generality of relationships between traits and range shifts remains ambiguous however, especially for imperiled fishes residing in xeric riverscapes. Our objectives were to quantify contemporary fish distributions in the Lower Colorado River Basin, forecast climate change by 2085 using two general circulation models, and quantify shifts in the limits, center, and size of fish elevational ranges according to fish traits. We examined relationships among traits and range shift metrics either singly using univariate linear modeling or combined with multivariate redundancy analysis. We found that trophic and dispersal traits were associated with shifts at the leading and trailing edges, respectively, although projected range shifts were largely unexplained by traits. As expected, piscivores and omnivores with broader diets shifted upslope most at the leading edge while more specialized invertivores exhibited minimal changes. Fishes that were more mobile shifted upslope most at the trailing edge, defying predictions. No traits explained changes in range center or size. Finally, current preference explained multivariate range shifts, as fishes with faster current preferences exhibited smaller multivariate changes. Although range shifts were largely unexplained by traits, more specialized invertivorous fishes with lower dispersal propensity or greater current preference may require the greatest conservation efforts because of their limited capacity to shift ranges under climate change.

Orientation of airborne laser scanning point clouds with multi-view, multi-scale image blocks.

PubMed

Rönnholm, Petri; Hyyppä, Hannu; Hyyppä, Juha; Haggrén, Henrik

2009-01-01

Comprehensive 3D modeling of our environment requires integration of terrestrial and airborne data, which is collected, preferably, using laser scanning and photogrammetric methods. However, integration of these multi-source data requires accurate relative orientations. In this article, two methods for solving relative orientation problems are presented. The first method includes registration by minimizing the distances between of an airborne laser point cloud and a 3D model. The 3D model was derived from photogrammetric measurements and terrestrial laser scanning points. The first method was used as a reference and for validation. Having completed registration in the object space, the relative orientation between images and laser point cloud is known. The second method utilizes an interactive orientation method between a multi-scale image block and a laser point cloud. The multi-scale image block includes both aerial and terrestrial images. Experiments with the multi-scale image block revealed that the accuracy of a relative orientation increased when more images were included in the block. The orientations of the first and second methods were compared. The comparison showed that correct rotations were the most difficult to detect accurately by using the interactive method. Because the interactive method forces laser scanning data to fit with the images, inaccurate rotations cause corresponding shifts to image positions. However, in a test case, in which the orientation differences included only shifts, the interactive method could solve the relative orientation of an aerial image and airborne laser scanning data repeatedly within a couple of centimeters.

Orientation of Airborne Laser Scanning Point Clouds with Multi-View, Multi-Scale Image Blocks

PubMed Central

Rönnholm, Petri; Hyyppä, Hannu; Hyyppä, Juha; Haggrén, Henrik

2009-01-01

Comprehensive 3D modeling of our environment requires integration of terrestrial and airborne data, which is collected, preferably, using laser scanning and photogrammetric methods. However, integration of these multi-source data requires accurate relative orientations. In this article, two methods for solving relative orientation problems are presented. The first method includes registration by minimizing the distances between of an airborne laser point cloud and a 3D model. The 3D model was derived from photogrammetric measurements and terrestrial laser scanning points. The first method was used as a reference and for validation. Having completed registration in the object space, the relative orientation between images and laser point cloud is known. The second method utilizes an interactive orientation method between a multi-scale image block and a laser point cloud. The multi-scale image block includes both aerial and terrestrial images. Experiments with the multi-scale image block revealed that the accuracy of a relative orientation increased when more images were included in the block. The orientations of the first and second methods were compared. The comparison showed that correct rotations were the most difficult to detect accurately by using the interactive method. Because the interactive method forces laser scanning data to fit with the images, inaccurate rotations cause corresponding shifts to image positions. However, in a test case, in which the orientation differences included only shifts, the interactive method could solve the relative orientation of an aerial image and airborne laser scanning data repeatedly within a couple of centimeters. PMID:22454569

Dissociable Modulation of Overt Visual Attention in Valence and Arousal Revealed by Topology of Scan Path

PubMed Central

Ni, Jianguang; Jiang, Huihui; Jin, Yixiang; Chen, Nanhui; Wang, Jianhong; Wang, Zhengbo; Luo, Yuejia; Ma, Yuanye; Hu, Xintian

2011-01-01

Emotional stimuli have evolutionary significance for the survival of organisms; therefore, they are attention-grabbing and are processed preferentially. The neural underpinnings of two principle emotional dimensions in affective space, valence (degree of pleasantness) and arousal (intensity of evoked emotion), have been shown to be dissociable in the olfactory, gustatory and memory systems. However, the separable roles of valence and arousal in scene perception are poorly understood. In this study, we asked how these two emotional dimensions modulate overt visual attention. Twenty-two healthy volunteers freely viewed images from the International Affective Picture System (IAPS) that were graded for affective levels of valence and arousal (high, medium, and low). Subjects' heads were immobilized and eye movements were recorded by camera to track overt shifts of visual attention. Algebraic graph-based approaches were introduced to model scan paths as weighted undirected path graphs, generating global topology metrics that characterize the algebraic connectivity of scan paths. Our data suggest that human subjects show different scanning patterns to stimuli with different affective ratings. Valence salient stimuli (with neutral arousal) elicited faster and larger shifts of attention, while arousal salient stimuli (with neutral valence) elicited local scanning, dense attention allocation and deep processing. Furthermore, our model revealed that the modulatory effect of valence was linearly related to the valence level, whereas the relation between the modulatory effect and the level of arousal was nonlinear. Hence, visual attention seems to be modulated by mechanisms that are separate for valence and arousal. PMID:21494331

Common MRI acquisition non-idealities significantly impact the output of the boundary shift integral method of measuring brain atrophy on serial MRI.

PubMed

Preboske, Gregory M; Gunter, Jeff L; Ward, Chadwick P; Jack, Clifford R

2006-05-01

Measuring rates of brain atrophy from serial magnetic resonance imaging (MRI) studies is an attractive way to assess disease progression in neurodegenerative disorders, particularly Alzheimer's disease (AD). A widely recognized approach is the boundary shift integral (BSI). The objective of this study was to evaluate how several common scan non-idealities affect the output of the BSI algorithm. We created three types of image non-idealities between the image volumes in a serial pair used to measure between-scan change: inconsistent image contrast between serial scans, head motion, and poor signal-to-noise (SNR). In theory the BSI volume difference measured between each pair of images should be zero and any deviation from zero should represent corruption of the BSI measurement by some non-ideality intentionally introduced into the second scan in the pair. Two different BSI measures were evaluated, whole brain and ventricle. As the severity of motion, noise, and non-congruent image contrast increased in the second scan, the calculated BSI values deviated progressively more from the expected value of zero. This study illustrates the magnitude of the error in measures of change in brain and ventricle volume across serial MRI scans that can result from commonly encountered deviations from ideal image quality. The magnitudes of some of the measurement errors seen in this study exceed the disease effect in AD shown in various publications, which range from 1% to 2.78% per year for whole brain atrophy and 5.4% to 13.8% per year for ventricle expansion (Table 1). For example, measurement error may exceed 100% if image contrast properties dramatically differ between the two scans in a measurement pair. Methods to maximize consistency of image quality over time are an essential component of any quantitative serial MRI study.

Numerical study of wavelength-swept semiconductor ring lasers: the role of refractive-index nonlinearities in semiconductor optical amplifiers and implications for biomedical imaging applications.

PubMed

Bilenca, A; Yun, S H; Tearney, G J; Bouma, B E

2006-03-15

Recent results have demonstrated unprecedented wavelength-tuning speed and repetition rate performance of semiconductor ring lasers incorporating scanning filters. However, several unique operational characteristics of these lasers have not been adequately explained, and the lack of an accurate model has hindered optimization. We numerically investigated the characteristics of these sources, using a semiconductor optical amplifier (SOA) traveling-wave Langevin model, and found good agreement with experimental measurements. In particular, we explored the role of the SOA refractive-index nonlinearities in determining the intracavity frequency-shift-broadening and the emitted power dependence on scan speed and direction. Our model predicts both continuous-wave and pulse operation and shows a universal relationship between the output power of lasers that have different cavity lengths and the filter peak frequency shift per round trip, therefore revealing the advantage of short cavities for high-speed biomedical imaging.

Bragg projection ptychography on niobium phase domains

NASA Astrophysics Data System (ADS)

Burdet, Nicolas; Shi, Xiaowen; Clark, Jesse N.; Huang, Xiaojing; Harder, Ross; Robinson, Ian

2017-07-01

Bragg projection ptychography (BPP) is a coherent x-ray diffraction imaging technique which combines the strengths of scanning microscopy with the phase contrast of x-ray ptychography. Here we apply it for high resolution imaging of the phase-shifted crystalline domains associated with epitaxial growth. The advantages of BPP are that the spatial extent of the sample is arbitrary, it is nondestructive, and it gives potentially diffraction limited spatial resolution. Here we demonstrate the application of BPP for revealing the domain structure caused by epitaxial misfit in a nanostructured metallic thin film. Experimental coherent diffraction data were collected from a niobium thin film, epitaxially grown on a sapphire substrate as the beam was scanned across the sample. The data were analyzed by BPP using a carefully selected combination of refinement procedures. The resulting image shows a close packed array of epitaxial domains, shifted with respect to each other due to misfit between the film and its substrate.

Developing Intercultural Awareness Using Digital Storytelling

ERIC Educational Resources Information Center

Ribiero, Sandre P. M.

2016-01-01

Higher Education mirrors the shifting nature of society and work. Mobility may provide unparalleled learning opportunities for all stakeholders; however, in order to live and work in plural societies as socially responsible and intercultural knowledgeable citizens, intercultural awareness and intercultural communication skills need to be mastered.…

State Efforts to Reform Schools: Treading between a Regulatory Swamp and an English Garden.

ERIC Educational Resources Information Center

Timar, Thomas B.; Kirp, David L.

1988-01-01

The educational reform strategies of Texas, California, and South Carolina are examined as they relate to reform outcomes. The current effort toward educational excellence must shift its focus from regulation and compliance monitoring to mobilization of institutional capacity. (SLD)

Mobile Disdrometer Observations of Nocturnal Mesoscale Convective Systems During PECAN

NASA Astrophysics Data System (ADS)

Bodine, D. J.; Rasmussen, K. L.

2015-12-01

Understanding microphysical processes in nocturnal mesoscale convective systems (MCSs) is an important objective of the Plains Elevated Convection At Night (PECAN) experiment, which occurred from 1 June - 15 July 2015 in the central Great Plains region of the United States. Observations of MCSs were collected using a large array of mobile and fixed instrumentation, including ground-based radars, soundings, PECAN Integrated Sounding Arrays (PISAs), and aircraft. In addition to these observations, three mobile Parsivel disdrometers were deployed to obtain drop-size distribution (DSD) measurements to further explore microphysical processes in convective and stratiform regions of nocturnal MCSs. Disdrometers were deployed within close range of a multiple frequency network of mobile and fixed dual-polarization radars (5 - 30 km range), and near mobile sounding units and PISAs. Using mobile disdrometer and multiple-wavelength, dual-polarization radar data, microphysical properties of convective and stratiform regions of MCSs are investigated. The analysis will also examine coordinated Range-Height Indicator (RHI) scans over the disdrometers to elucidate vertical DSD structure. Analysis of dense observations obtained during PECAN in combination with mobile disdrometer DSD measurements contributes to a greater understanding of the structural characteristics and evolution of nocturnal MCSs.

Results of the survey activities and mobile gamma scanning in Monticello, Utah

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

Little, C.A.; Berven, B.A.

The town of Monticello, Utah, was once the site of an active mill which processed vanadium ore (1942 to 1948), and uranium ore (1948 to 1960). Properties in the vicinity of that mill have become contaminated with radioactive material from ore processing. The Radiological Survey Activities (RASA) group at Oak Ridge National Laboratory (ORNL) was requested by the Division of Remedial Action Projects (DRAP) in the Department of Energy (DOE) to: (1) identify potentially contaminated properties; (2) assess natural background radiation levels; and (3) rapidly assess the magnitude, extent, and type (i.e. ore, tailings, etc.) of contamination present on thesemore » properties (if any). This survey was conducted by RASA during April 1983. In addition to the 114 properties previously identified from historical information, the ORNL mobile gamma scanning van located 36 new properties exhibiting anomalous gamma radiation levels. Onsite surveys were conducted on 145 of the 150 total properties identified either historically or with the gamma scanning van. Of these 145 properties, 122 of them appeared to have some type of contaminated material present on them; however, only 48 appeared to be contaminated to the extent where they were in excess of Environmental Protection Agency (EPA) criteria (40 CFR 192). Twenty-one other properties were recommended for additional investigation (indoor gamma scanning and radon daughter measurements); of these, only ten required further analysis. This report provides the detailed data and analyses related to the radiological survey efforts performed by ORNL in Monticello, Utah.« less

Fast Lamb wave energy shift approach using fully contactless ultrasonic system to characterize concrete structures

NASA Astrophysics Data System (ADS)

Ham, Suyun; Popovics, John S.

2015-03-01

Ultrasonic techniques provide an effective non-destructive evaluation (NDE) method to monitor concrete structures, but the need to perform rapid and accurate structural assessment requires evaluation of hundreds, or even thousands, of measurement datasets. Use of a fully contactless ultrasonic system can save time and labor through rapid implementation, and can enable automated and controlled data acquisition, for example through robotic scanning. Here we present results using a fully contactless ultrasonic system. This paper describes our efforts to develop a contactless ultrasonic guided wave NDE approach to detect and characterize delamination defects in concrete structures. The developed contactless sensors, controlled scanning system, and employed Multi-channel Analysis of Surface Waves (MASW) signal processing scheme are reviewed. Then a guided wave interpretation approach for MASW data is described. The presence of delamination is interpreted by guided plate wave (Lamb wave) behavior, where a shift in excited Lamb mode phase velocity, is monitored. Numerically simulated and experimental ultrasonic data collected from a concrete sample with simulated delamination defects are presented, where the occurrence of delamination is shown to be associated with a mode shift in Lamb wave energy.

Melting, crystallization and storage stability of virgin coconut oil and its blends by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR).

PubMed

Srivastava, Yashi; Semwal, Anil Dutt; Sajeevkumar, Vallayil Appukuttan; Sharma, G K

2017-01-01

The blends were prepared of virgin coconut oil with refined soyabean oil (VCO-RSOY) and refined safflower oil (VCO-RSAFF). Blending with VCO improved the fatty acid composition which increased the shelf stability of 20:80 VCO-RSOY and VCO-RSAFF up to 12 months in different packaging systems such as low density polyethylene, linear low density polyethylene, metalized polyester pouches, polyethylene teteraphthalate, high density polyethylene (HDPE), Amber HDPE bottle. The specific spectral regions of FTIR proved to be very useful for the determination of adulteration as well as for the study of oxidation process. Band shifts observed at 3008, 1652, 1397, 1097, 912 and 845 cm -1 have been used to differentiate RSAFF from VCO. VCO spectrums did not have these chemical shifts. Further the spectrum of RSOY showed same band shifts as RSAFF except 1652, 1397, 869.6 and 845 cm -1 . Differential Scanning Calorimetry provided useful information regarding the nature of thermodynamic changes related to physical state of vegetable oil. The physical state changes included melting and crystallization events which require the intake and release of energy.

Radiation dose calculations for CT scans with tube current modulation using the approach to equilibrium function

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

Li, Xinhua; Zhang, Da; Liu, Bob, E-mail: bliu7@mgh.harvard.edu

2014-11-01

Purpose: The approach to equilibrium function has been used previously to calculate the radiation dose to a shift-invariant medium undergoing CT scans with constant tube current [Li, Zhang, and Liu, Med. Phys. 39, 5347–5352 (2012)]. The authors have adapted this method to CT scans with tube current modulation (TCM). Methods: For a scan with variable tube current, the scan range was divided into multiple subscan ranges, each with a nearly constant tube current. Then the dose calculation algorithm presented previously was applied. For a clinical CT scan series that presented tube current per slice, the authors adopted an efficient approachmore » that computed the longitudinal dose distribution for one scan length equal to the slice thickness, which center was at z = 0. The cumulative dose at a specific point was a summation of the contributions from all slices and the overscan. Results: The dose calculations performed for a total of four constant and variable tube current distributions agreed with the published results of Dixon and Boone [Med. Phys. 40, 111920 (14pp.) (2013)]. For an abdomen/pelvis scan of an anthropomorphic phantom (model ATOM 701-B, CIRS, Inc., VA) on a GE Lightspeed Pro 16 scanner with 120 kV, N × T = 20 mm, pitch = 1.375, z axis current modulation (auto mA), and angular current modulation (smart mA), dose measurements were performed using two lines of optically stimulated luminescence dosimeters, one of which was placed near the phantom center and the other on the surface. Dose calculations were performed on the central and peripheral axes of a cylinder containing water, whose cross-sectional mass was about equal to that of the ATOM phantom in its abdominal region, and the results agreed with the measurements within 28.4%. Conclusions: The described method provides an effective approach that takes into account subject size, scan length, and constant or variable tube current to evaluate CT dose to a shift-invariant medium. For a clinical CT scan, dose calculations may be performed with a water-containing cylinder whose cross-sectional mass is equal to that of the subject. This method has the potential to substantially improve evaluations of patient dose from clinical CT scans, compared to CTDI{sub vol}, size-specific dose estimate (SSDE), or the dose evaluated for a TCM scan with a constant tube current equal to the average tube current of the TCM scan.« less

An Ultrasonic Scanning Technique for In-Situ `Bowing' Measurement of Prototype Fast Breeder Reactor Fuel Sub-Assembly

NASA Astrophysics Data System (ADS)

Swaminathan, K.; Asokane, C.; Sylvia, J. I.; Kalyanasundaram, P.; Swaminathan, P.

2012-02-01

An ultrasonic under-sodium scanner has been developed for deployment in Prototype Fast Breeder Reactor (PFBR) which is in advanced stage of construction at Kalpakkam, India. Its purpose is to scan the above-core plenum for detection, if any, of displacement of sub-assemblies. During its burn-up in the reactor, the head of a Fuel Sub-Assembly (FSA) may undergo a lateral shift from its original position (called `bowing') due to the fast neutron induced damage on its structural material. A simple scanning technique has been developed for measuring the extent of bowing in-situ. This paper describes a PC-controlled mock-up of the scanner used to implement the scanning technique and the results obtained of scanning a mock-up FSA head under water. The details of the liquid-sodium proof transducer developed for use in the PFBR scanner and its performance are also discussed.

Comparison of the biometric formulas used for applanation A-scan ultrasound biometry.

PubMed

Özcura, Fatih; Aktaş, Serdar; Sağdık, Hacı Murat; Tetikoğlu, Mehmet

2016-10-01

The purpose of the study was to compare the accuracy of various biometric formulas for predicting postoperative refraction determined using applanation A-scan ultrasound. This retrospective comparative study included 485 eyes that underwent uneventful phacoemulsification with intraocular lens (IOL) implantation. Applanation A-scan ultrasound biometry and postoperative manifest refraction were obtained in all eyes. Biometric data were entered into each of the five IOL power calculation formulas: SRK-II, SRK/T, Holladay I, Hoffer Q, and Binkhorst II. All eyes were divided into three groups according to axial length: short (≤22.0 mm), average (22.0-25.0 mm), and long (≥25.0 mm) eyes. The postoperative spherical equivalent was calculated and compared with the predicted refractive error using each biometric formula. The results showed that all formulas had significantly lower mean absolute error (MAE) in comparison with Binkhorst II formula (P < 0.01). The lowest MAE was obtained with the SRK-II for average (0.49 ± 0.40 D) and short (0.67 ± 0.54 D) eyes and the SRK/T for long (0.61 ± 0.50 D) eyes. The highest postoperative hyperopic shift was seen with the SRK-II for average (46.8 %), short (28.1 %), and long (48.4 %) eyes. The highest postoperative myopic shift was seen with the Holladay I for average (66.4 %) and long (71.0 %) eyes and the SRK/T for short eyes (80.6 %). In conclusion, the SRK-II formula produced the lowest MAE in average and short eyes and the SRK/T formula produced the lowest MAE in long eyes. The SRK-II has the highest postoperative hyperopic shift in all eyes. The highest postoperative myopic shift is with the Holladay I for average and long eyes and SRK/T for short eyes.

Relating Linear and Volumetric Variables Through Body Scanning to Improve Human Interfaces in Space

NASA Technical Reports Server (NTRS)

Margerum, Sarah E.; Ferrer, Mike A.; Young, Karen S.; Rajulu, Sudhakar

2010-01-01

Designing space suits and vehicles for the diverse human population present unique challenges for the methods of traditional anthropometry. Space suits are bulky and allow the operator to shift position within the suit and inhibit the ability to identify body landmarks. Limited suit sizing options also cause variability in fit and performance between similarly sized individuals. Space vehicles are restrictive in volume in both the fit and the ability to collect data. NASA's Anthropometric and Biomechanics Facility (ABF) has utilized 3D scanning to shift from traditional linear anthropometry to explore and examine volumetric capabilities to provide anthropometric solutions for design. Overall, the key goals are to improve the human-system performance and develop new processes to aid in the design and evaluation of space systems. Four case studies are presented that illustrate the shift from purely linear analyses to an augmented volumetric toolset to predict and analyze the human within the space suit and vehicle. The first case study involves the calculation of maximal head volume to estimate total free volume in the helmet for proper air exchange. Traditional linear measurements resulted in an inaccurate representation of the head shape, yet limited data exists for the determination of a large head volume. Steps were first taken to identify and classify a maximum head volume and the resulting comparisons to the estimate are presented in this paper. This study illustrates the gap between linear components of anthropometry and the need for overall volume metrics in order to provide solutions. A second case study examines the overlay of the space suit scans and components onto scanned individuals to quantify fit and clearance to aid in sizing the suit to the individual. Restrictions in space suit size availability present unique challenges to optimally fit the individual within a limited sizing range while maintaining performance. Quantification of the clearance and fit between similarly sized individuals is critical in providing a greater understanding of the human body's function within the suit. The third case study presented in this paper explores the development of a conformal seat pan using scanning techniques, and details the challenges of volumetric analyses that were overcome in order to develop a universal seat pan that can be utilized across the entire user population. The final case study explores expanding volumetric capabilities through generation of boundary manikins. Boundary manikins are representative individuals from the population of interest that represent the extremes of the population spectrum. The ABF developed a technique to take three-dimensional scans of individuals and manipulate the scans to reflect the boundary manikins' anthropometry. In essence, this process generates a representative three-dimensional scan of an individual from anthropometry, using another individual's scanned image. The results from this process can be used in design process modeling and initial suit sizing work as a three dimensional, realistic example of individuals from the population, maintaining the variability between and correlation to the relevant dimensions of interest.

Immersive realities: articulating the shift from VR to mobile AR through artistic practice

NASA Astrophysics Data System (ADS)

Margolis, Todd; Cornish, Tracy; Berry, Rodney; DeFanti, Thomas A.

2012-03-01

Our contemporary imaginings of technological engagement with digital environments has transitioned from flying through Virtual Reality to mobile interactions with the physical world through personal media devices. Experiences technologically mediated through social interactivity within physical environments are now being preferenced over isolated environments such as CAVEs or HMDs. Examples of this trend can be seen in early tele-collaborative artworks which strove to use advanced networking to join multiple participants in shared virtual environments. Recent developments in mobile AR allow untethered access to such shared realities in places far removed from labs and home entertainment environments, and without the bulky and expensive technologies attached to our bodies that accompany most VR. This paper addresses the emerging trend favoring socially immersive artworks via mobile Augmented Reality rather than sensorially immersive Virtual Reality installations. With particular focus on AR as a mobile, locative technology, we will discuss how concepts of immersion and interactivity are evolving with this new medium. Immersion in context of mobile AR can be redefined to describe socially interactive experiences. Having distinctly different sensory, spatial and situational properties, mobile AR offers a new form for remixing elements from traditional virtual reality with physically based social experiences. This type of immersion offers a wide array of potential for mobile AR art forms. We are beginning to see examples of how artists can use mobile AR to create social immersive and interactive experiences.

Spatial Shifts in Tidal-Fluvial Environments

NASA Astrophysics Data System (ADS)

Dykstra, S. L.; Dzwonkowski, B.

2017-12-01

Fresh water discharge damps tidal propagation and increases the phase lag, which has important impacts on system-wide sediment transport process and ecological structure. Here, the role of discharge on spatial variability in the dynamics of tidal rivers is investigated in Mobile Bay and Delta, a microtidal diurnal system where discharge ranges multiple orders of magnitude. Long-term observations at 7 velocity stations and 20 water level stations, ranging over 260km along the system, were analyzed. Observations of the tidal extinguishing point in both velocity and water level were highly variable with significant shifts in location covering a distance over 140km. The velocity stations also allowed for measuring the extent of flood (i.e. point where tidal flow is arrested by discharge) shifting 100km. With increased discharge, flow characteristics at station locations can transition from an estuary (i.e. bidirectional tidal flow) to a tidal river to a traditional fluvial environment. This revealed systematic discharge induced damping and an increase in phase lag. Interestingly, before damping occurs, the tide amplifies ( 15%) seaward of the extent of flood. Another consistent pattern is the higher sensitivity of the velocity signal to discharge than water level. This causes the velocity to lag more and create progressive tides. In a microtidal diurnal system, the signal propagates further inland than a semidiurnal tide due to its lower frequency but is easily damped due to the small amplitude, creating large shifts. Previous research has focused on environments dominated by semidiurnal tides with similar magnitudes to discharge using water level observations. For example, the well studied Columbia and the St. Lawrence rivers have small shifts in their tidal extinguishing point O(10km) (Jay 2016, Matte 2014). These shifts are not large enough to observe process like discharge-induced amplification and damping at the same site like in the Mobile system, but they may indicate a decoupling of the water level and velocity signal by discharge. Throughout the world, shifts in tidal rivers are created by seasonal discharge patterns, but large storms can quickly disrupt a system and move it over 140km in a few days.

A self-reference PRF-shift MR thermometry method utilizing the phase gradient

NASA Astrophysics Data System (ADS)

Langley, Jason; Potter, William; Phipps, Corey; Huang, Feng; Zhao, Qun

2011-12-01

In magnetic resonance (MR) imaging, the most widely used and accurate method for measuring temperature is based on the shift in proton resonance frequency (PRF). However, inter-scan motion and bulk magnetic field shifts can lead to inaccurate temperature measurements in the PRF-shift MR thermometry method. The self-reference PRF-shift MR thermometry method was introduced to overcome such problems by deriving a reference image from the heated or treated image, and approximates the reference phase map with low-order polynomial functions. In this note, a new approach is presented to calculate the baseline phase map in self-reference PRF-shift MR thermometry. The proposed method utilizes the phase gradient to remove the phase unwrapping step inherent to other self-reference PRF-shift MR thermometry methods. The performance of the proposed method was evaluated using numerical simulations with temperature distributions following a two-dimensional Gaussian function as well as phantom and in vivo experimental data sets. The results from both the numerical simulations and experimental data show that the proposed method is a promising technique for measuring temperature.

Modification and Mobility of Dunes and Ripples in Middle and High Southern Latitude Dune Fields

NASA Astrophysics Data System (ADS)

Banks, M.; Fenton, L. K.; Chojnacki, M.; Silvestro, S.

2017-12-01

Change detection analyses of aeolian bedforms (dunes and ripples), using multi-temporal images (0.25 m/pixel) acquired by the High Resolution Imaging Science Experiment (HiRISE), reveal changes and migration of some bedforms. We now have a database of 200 dune fields with migration rates for bedforms that are mobile. Results show that most northern (N) hemisphere bedforms show movement, while 50% of southern (S) hemisphere bedforms show no detectable changes. In particular, bedforms located >70° N are consistently mobile and exhibit high sand fluxes while S hemisphere bedforms progressively decrease in mobility with proximity to the S pole. We analyze HiRISE image pairs covering dune fields south of 40° S for evidence of movement and apply a dune stability index (SI) based on the presence/lack of superposed non-aeolian features and degree of degradation by non-aeolian processes (0-6, higher numbers indicating increasing evidence of stability/modification). Combining mobility data and SI for 71 dune fields, we find a clear trend of decreasing sand mobility and increasing SI with latitude: 1) both dunes and ripples are more commonly mobile at lower latitudes, although some high-latitude ripples are migrating, 2) dune fields with low SIs (≤3) tend to be active while those with higher SIs tend to be inactive, and 3) ripple migration rates decrease slightly with increasing latitude and SI, although this may be attributable to regional variations. The elevation of dune fields generally increases with increasing S latitude suggesting elevation, and decreasing pressure, may contribute to decreasing mobility. A change in dominance of active to inactive bedforms and a morphological shift to higher SIs (SI=2) both occur at 60º S and coincide with the edge of high concentrations of H2O-equivalent hydrogen content observed by the Neutron Spectrometer. This is consistent with previous studies suggesting stabilizing agents (e.g., ground ice), likely limit sediment movement (i.e. sand availability). Active dune fields with morphologies consistent with stability (i.e. migrating ripples with SI=3) may indicate possible competing influences of aeolian and non-aeolian processes (i.e. polar processes), or perhaps a temporal shift from earlier conditions dominated by polar processes to recent increases in aeolian activity.

Embed dynamic content in your poster.

PubMed

Hutchins, B Ian

2013-01-29

A new technology has emerged that will facilitate the presentation of dynamic or otherwise inaccessible data on posters at scientific meetings. Video, audio, or other digital files hosted on mobile-friendly sites can be linked to through a quick response (QR) code, a two-dimensional barcode that can be scanned by smartphones, which then display the content. This approach is more affordable than acquiring tablet computers for playing dynamic content and can reach many users at large conferences. This resource details how to host videos, generate QR codes, and view the associated files on mobile devices.

Indoor and Outdoor Mobile Mapping Systems for Architectural Surveys

NASA Astrophysics Data System (ADS)

Campi, M.; di Luggo, A.; Monaco, S.; Siconolfi, M.; Palomba, D.

2018-05-01

This paper presents the results of architectural surveys carried out with mobile mapping systems. The data acquired through different instruments for both indoor and outdoor surveying are analyzed and compared. The study sample shows what is required for an acquisition in a dynamic mode indicating the criteria for the creation of a georeferenced network for indoor spaces, as well as the operational processes concerning data capture, processing, and management. The differences between a dynamic and static scan have been evaluated, with a comparison being made with the aerial photogrammetric survey of the same sample.

Mobile Stroke Unit Reduces Time to Image Acquisition and Reporting.

PubMed

Nyberg, E M; Cox, J R; Kowalski, R G; Duarte, D V; Schimpf, B; Jones, W J

2018-05-17

Timely administration of thrombolytic therapy is critical to maximizing the likelihood of favorable outcomes in patients with acute ischemic stroke. Although emergency medical service activation overall improves the timeliness of acute stroke treatment, the time from emergency medical service dispatch to hospital arrival unavoidably decreases the timeliness of thrombolytic administration. Our mobile stroke unit, a new-generation ambulance with on-board CT scanning capability, reduces key imaging time metrics and facilitates in-the-field delivery of IV thrombolytic therapy. © 2018 by American Journal of Neuroradiology.

Provision of CT Scanning Capability to VA/DoD (Veterans Administration/ Department of Defense) Health Care Facilities through a Shared Mobile CT Unit: A Feasibility Study

DTIC Science & Technology

1984-07-27

all Federal sectoT facilities. Shared services have long been recna, nzed as one way to reduce costs, throuph optima’ itilizaticn of capacity, but...stock arguments against shared services . A CT scanner may be installed in a mobile van and the service moved in its entirety from hospital to hospital...annually. This severely restricted further acquisition by hospitals in most health service areas (5,9,14). Shared Services : A Response to Regulation

Grain-Size-Limited Mobility in Methylammonium Lead Iodide Perovskite Thin Films

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

Reid, Obadiah G.; Yang, Mengjin; Kopidakis, Nikos

2016-09-09

We report a systematic study of the gigahertz-frequency charge carrier mobility found in methylammonium lead iodide perovskite films as a function of average grain size using time-resolved microwave conductivity and a single processing chemistry. Our measurements are in good agreement with the Kubo formula for the AC mobility of charges confined within finite grains, suggesting (1) that the surface grains imaged via scanning electron microscopy are representative of the true electronic domain size and not substantially subdivided by twinning or other defects not visible by microscopy and (2) that the time scale of diffusive transport across grain boundaries is muchmore » slower than the period of the microwave field in this measurement (-100 ps). The intrinsic (infinite grain size) minimum mobility extracted form the model is 29 +/- 6 cm2 V-1 s-1 at the probe frequency (8.9 GHz).« less

Nonlocal nonlinear refraction in Hibiscus sabdariffa with large phase shifts.

PubMed

Ramírez-Martínez, D; Alvarado-Méndez, E; Trejo-Durán, M; Vázquez-Guevara, M A

2014-10-20

In this work we present a study of nonlinear optical properties in organic materials (hibiscus sabdariffa). Our results demonstrate that the medium exhibits a highly nonlocal nonlinear response. We show preliminary numerical results of the transmittance as nonlocal response by considering, simultaneously, the nonlinear absorption and refraction in media. Numerical results are accord to measurement obtained by Z- scan technique where we observe large phase shifts. We also analyze the far field diffraction ring patterns of the sample.

Velocity measurements in the plume of an arcjet engine

NASA Technical Reports Server (NTRS)

Pivirotto, T. J.; Deininger, W. D.

1987-01-01

A nonintrusive technique has been used to conduct a radial survey in the flow field of an arcjet engine plume. The technique measures the Doppler shift of an optically thin line resulting from recombination and relaxation processes in the high Mach number stream, in order to determine flow velocities. Atom temperature can also be calculated from the same Doppler-broadened line widths, when these shifts are measured with a scanning Fabry-Perot spectrometer whose design is presented in detail.

Fast two-layer two-photon imaging of neuronal cell populations using an electrically tunable lens

PubMed Central

Grewe, Benjamin F.; Voigt, Fabian F.; van ’t Hoff, Marcel; Helmchen, Fritjof

2011-01-01

Functional two-photon Ca2+-imaging is a versatile tool to study the dynamics of neuronal populations in brain slices and living animals. However, population imaging is typically restricted to a single two-dimensional image plane. By introducing an electrically tunable lens into the excitation path of a two-photon microscope we were able to realize fast axial focus shifts within 15 ms. The maximum axial scan range was 0.7 mm employing a 40x NA0.8 water immersion objective, plenty for typically required ranges of 0.2–0.3 mm. By combining the axial scanning method with 2D acousto-optic frame scanning and random-access scanning, we measured neuronal population activity of about 40 neurons across two imaging planes separated by 40 μm and achieved scan rates up to 20–30 Hz. The method presented is easily applicable and allows upgrading of existing two-photon microscopes for fast 3D scanning. PMID:21750778

Role of AlGaN/GaN interface traps on negative threshold voltage shift in AlGaN/GaN HEMT

NASA Astrophysics Data System (ADS)

Malik, Amit; Sharma, Chandan; Laishram, Robert; Bag, Rajesh Kumar; Rawal, Dipendra Singh; Vinayak, Seema; Sharma, Rajesh Kumar

2018-04-01

This article reports negative shift in the threshold-voltage in AlGaN/GaN high electron mobility transistor (HEMT) with application of reverse gate bias stress. The device is biased in strong pinch-off and low drain to source voltage condition for a fixed time duration (reverse gate bias stress), followed by measurement of transfer characteristics. Negative threshold voltage shift after application of reverse gate bias stress indicates the presence of more carriers in channel as compared to the unstressed condition. We propose the presence of AlGaN/GaN interface states to be the reason of negative threshold voltage shift, and developed a process to electrically characterize AlGaN/GaN interface states. We verified the results with Technology Computer Aided Design (TCAD) ATLAS simulation and got a good match with experimental measurements.

Origin of high carrier mobility and low residual stress in RF superimposed DC sputtered Al doped ZnO thin film for next generation flexible devices

NASA Astrophysics Data System (ADS)

Kumar, Naveen; Dubey, Ashish; Bahrami, Behzad; Venkatesan, S.; Qiao, Qiquan; Kumar, Mukesh

2018-04-01

In this work, the energy and flux of high energetic ions were controlled by RF superimposed DC sputtering process to increase the grain size and suppress grain boundary potential with minimum residual stress in Al doped ZnO (AZO) thin film. AZO thin films were deposited at different RF/(RF + DC) ratios by keeping total power same and were investigated for their electrical, optical, structural and nanoscale grain boundaries potential. All AZO thin film showed high crystallinity and orientation along (002) with peak shift as RF/(RF + DC) ratio increased from 0.0, pure DC, to 1.0, pure RF. This peak shift was correlated with high residual stress in as-grown thin film. AZO thin film grown at mixed RF/(RF + DC) of 0.75 showed high electron mobility, low residual stress and large crystallite size in comparison to other AZO thin films. The nanoscale grain boundary potential was mapped using Kelvin Probe Force Microscopy in all AZO thin film and it was observed that carrier mobility is controlled not only by grains size but also by grain boundary potential. The XPS analysis confirms the variation in oxygen vacancies and zinc interstitials which explain the origin of low grain boundaries potential and high carrier mobility in AZO thin film deposited at 0.75 RF/(RF + DC) ratio. This study proposes a new way to control the grain size and grain boundary potential to further tune the optoelectronic-mechanical properties of AZO thin films for next generation flexible and optoelectronic devices.

Advances in 4D Treatment Planning for Scanned Particle Beam Therapy — Report of Dedicated Workshops

PubMed Central

Bert, Christoph; Graeff, Christian; Riboldi, Marco; Nill, Simeon; Baroni, Guido; Knopf, Antje-Christin

2014-01-01

We report on recent progress in the field of mobile tumor treatment with scanned particle beams, as discussed in the latest editions of the 4D treatment planning workshop. The workshop series started in 2009, with about 20 people from 4 research institutes involved, all actively working on particle therapy delivery and development. The first workshop resulted in a summary of recommendations for the treatment of mobile targets, along with a list of requirements to apply these guidelines clinically. The increased interest in the treatment of mobile tumors led to a continuously growing number of attendees: the 2012 edition counted more than 60 participants from 20 institutions and commercial vendors. The focus of research discussions among workshop participants progressively moved from 4D treatment planning to complete 4D treatments, aiming at effective and safe treatment delivery. Current research perspectives on 4D treatments include all critical aspects of time resolved delivery, such as in-room imaging, motion detection, beam application, and quality assurance techniques. This was motivated by the start of first clinical treatments of hepato cellular tumors with a scanned particle beam, relying on gating or abdominal compression for motion mitigation. Up to date research activities emphasize significant efforts in investigating advanced motion mitigation techniques, with a specific interest in the development of dedicated tools for experimental validation. Potential improvements will be made possible in the near future through 4D optimized treatment plans that require upgrades of the currently established therapy control systems for time resolved delivery. But since also these novel optimization techniques rely on the validity of the 4DCT, research focusing on alternative 4D imaging technique, such as MRI based 4DCT generation will continue. PMID:24354749

Mapping atomic contact between pentacene and a Au surface using scanning tunneling spectroscopy.

PubMed

Song, Young Jae; Lee, Kyuho; Kim, Seong Heon; Choi, Byoung-Young; Yu, Jaejun; Kuk, Young

2010-03-10

We mapped spatially varying intramolecular electronic structures on a pentacene-gold interface using scanning tunneling spectroscopy. Along with ab initio calculations based on density functional theory, we found that the directional nature of the d orbitals of Au atoms plays an important role in the interaction at the pentacene-gold contact. The gold-induced interface states are broadened and shifted by various pentacene-gold distances determined by the various registries of a pentacene molecule on a gold substrate.

Realization of a quantum Hamiltonian Boolean logic gate on the Si(001):H surface.

PubMed

Kolmer, Marek; Zuzak, Rafal; Dridi, Ghassen; Godlewski, Szymon; Joachim, Christian; Szymonski, Marek

2015-08-07

The design and construction of the first prototypical QHC (Quantum Hamiltonian Computing) atomic scale Boolean logic gate is reported using scanning tunnelling microscope (STM) tip-induced atom manipulation on an Si(001):H surface. The NOR/OR gate truth table was confirmed by dI/dU STS (Scanning Tunnelling Spectroscopy) tracking how the surface states of the QHC quantum circuit on the Si(001):H surface are shifted according to the input logical status.

The effect on road safety of a modal shift from car to bicycle.

PubMed

Stipdonk, Henk; Reurings, Martine

2012-01-01

To describe and apply a method to assess the effect on road safety of a modal shift from cars to bicycles. Ten percent of all car trips shorter than 7.5 km were assumed to be replaced by bicycle trips. Single-vehicle and multivehicle crashes involving cars and/or bicycles were considered. The safety of car occupants and cyclists was taken into account as well as the safety of other road users involved in such crashes. The computations were carried out by age and gender. Assuming constant risk (casualties per distance traveled), the expected number of accidents is proportional to the mobility shift. Several types of risk were considered: the risk of being injured as a car driver or cyclist and the risk of being involved as a car driver or cyclist in a crash in which another road user is injured. The results indicated that the total gain of the modal shift was negative for fatalities, which means that there was a net increase in the number of fatalities. The modal shift was advantageous for young drivers and disadvantageous for elderly drivers. In addition, it was more positive for males than for females. The turning point was around the age of 35. For hospitalized casualties, due to the strong influence of the many hospitalized cyclists in nonmotorized vehicle crashes, there was a strong negative overall effect, and the modal shift resulted in a positive effect for 18- and 19-year-old males only. Overall, a small increase (up to 1%) in the number of cyclist fatalities and a greater increase of 3.5 percent in the number of inpatients was expected. The increase in casualties was mainly due to the proportion of single-vehicle bicycle crashes with serious injuries in relation to the total number of injured cyclists. The effect of the modal shift was shown to depend on age and gender, resulting in fewer casualties for younger drivers and for women. It is possible to provide a first approximation of the effect on road safety of a mobility shift from cars to bicycles. This approximation indicates that, in general, road safety does not benefit from this modal shift. The effect differs for gender and age groups. Elderly drivers are safer inside a car than on a bicycle. For the number of hospitalized casualties, the modal shift increases the number of casualties for practically all ages and both genders.

Fatigue mitigation with SleepTrackTXT2 in air medical emergency care systems: study protocol for a randomized controlled trial.

PubMed

Patterson, P Daniel; Moore, Charity G; Guyette, Frank X; Doman, Jack M; Sequeira, Denisse; Werman, Howard A; Swanson, Doug; Hostler, David; Lynch, Joshua; Russo, Lindsey; Hines, Linda; Swecker, Karen; Runyon, Michael S; Buysse, Daniel J

2017-06-05

Most air medical Emergency Medical Services (EMS) clinicians work extended duration shifts, and more than 50% report inadequate sleep, poor sleep quality, and/or poor recovery between shifts. The SleepTrackTXT pilot trial (ClinicalTrials.gov, NCT02063737) showed that use of mobile phone text messages could impact EMS clinician self-reported fatigue and sleepiness during long duration shifts. The purpose of the SleepTrackTXT2 trial is to leverage lessons learned from the first SleepTrackTXT study and test an enhanced intervention targeting air medical EMS clinicians. We will conduct a multi-site randomized trial with a sample of adult EMS clinicians recruited from four air medical EMS systems located in the midwest, northeastern, and southern USA. Participants will be allocated to one of two possible arms for a 4-month (120-day) study period. The intervention arm will involve text-message assessments of sleepiness, fatigue, and difficulty concentrating at the beginning, every 4 hours during, and at the end of scheduled shifts. Participants reporting high levels of sleepiness, fatigue, or difficulty with concentration will receive one of nine randomly selected intervention messages to promote behavior change during shift work to improve alertness. Intervention participants will receive a text-message report on Friday of each week that shows their sleep debt over the previous 7 days followed by a text message to promote paying back sleep debt recovery when feasible. Participants in the control group receive text messages that only include assessments. Both arms will receive text-message assessments of perceived recovery since last shift, sleepiness, fatigue, or difficulty with concentration at noon (1200 hours) on days between scheduled shifts (off-duty days). We have two aims for this study: (1) to determine the short-term impact of the enhanced SleepTrackTXT2 intervention on air medical clinician fatigue reported in real time during and at the end of shift work, and (2) to determine the long-term impact of the SleepTrackTXT2 intervention on sleep quality and sleep health indicators including hours of sleep and recovery between shift work. The SleepTrackTXT2 trial may provide evidence of real-world effectiveness that would support widespread expansion of fatigue mitigation interventions in emergency care clinician shift workers. The trial may specifically support use of real-time assessments and interventions delivered via mobile technology such as text messaging. ClinicalTrials.gov, NCT02783027 . Registered on 23 May 2016.

Probing cation and vacancy ordering in the dry and hydrated yttrium-substituted BaSnO3 perovskite by NMR spectroscopy and first principles calculations: implications for proton mobility.

PubMed

Buannic, Lucienne; Blanc, Frédéric; Middlemiss, Derek S; Grey, Clare P

2012-09-05

Hydrated BaSn(1-x)Y(x)O(3-x/2) is a protonic conductor that, unlike many other related perovskites, shows high conductivity even at high substitution levels. A joint multinuclear NMR spectroscopy and density functional theory (total energy and GIPAW NMR calculations) investigation of BaSn(1-x)Y(x)O(3-x/2) (0.10 ≤ x ≤ 0.50) was performed to investigate cation ordering and the location of the oxygen vacancies in the dry material. The DFT energetics show that Y doping on the Sn site is favored over doping on the Ba site. The (119)Sn chemical shifts are sensitive to the number of neighboring Sn and Y cations, an experimental observation that is supported by the GIPAW calculations and that allows clustering to be monitored: Y substitution on the Sn sublattice is close to random up to x = 0.20, while at higher substitution levels, Y-O-Y linkages are avoided, leading, at x = 0.50, to strict Y-O-Sn alternation of B-site cations. These results are confirmed by the absence of a "Y-O-Y" (17)O resonance and supported by the (17)O NMR shift calculations. Although resonances due to six-coordinate Y cations were observed by (89)Y NMR, the agreement between the experimental and calculated shifts was poor. Five-coordinate Sn and Y sites (i.e., sites next to the vacancy) were observed by (119)Sn and (89)Y NMR, respectively, these sites disappearing on hydration. More five-coordinated Sn than five-coordinated Y sites are seen, even at x = 0.50, which is ascribed to the presence of residual Sn-O-Sn defects in the cation-ordered material and their ability to accommodate O vacancies. High-temperature (119)Sn NMR reveals that the O ions are mobile above 400 °C, oxygen mobility being required to hydrate these materials. The high protonic mobility, even in the high Y-content materials, is ascribed to the Y-O-Sn cation ordering, which prevents proton trapping on the more basic Y-O-Y sites.

Stimulation of hepatocytic AMP-activated protein kinase by okadaic acid and other autophagy-suppressive toxins

PubMed Central

2004-01-01

Autophagic activity in isolated rat hepatocytes is strongly suppressed by OA (okadaic acid) and other PP (protein phosphatase)-inhibitory toxins as well as by AICAR (5-aminoimidazole-4-carboxamide riboside), a direct activator of AMPK (AMP-activated protein kinase). To investigate whether AMPK is a mediator of the effects of the toxin, a phosphospecific antibody directed against the activation of phosphorylation of the AMPK α (catalytic)-subunit at Thr172 was used to assess the activation status of this enzyme. AICAR as well as all the toxins tested (OA, microcystin-LR, calyculin A, cantharidin and tautomycin) induced strong, dose-dependent AMPKα phosphorylation, correlating with AMPK activity in situ (in intact hepatocytes) as measured by the AMPK-dependent phosphorylation of acetyl-CoA carboxylase at Ser79. All treatments induced the appearance of multiple, phosphatase-sensitive, low-mobility forms of the AMPK α-subunit, consistent with phosphorylation at several sites other than Thr172. The flavonoid naringin, an effective antagonist of OA-induced autophagy suppression, inhibited the AMPK phosphorylation and mobility shifting induced by AICAR, OA or microcystin, but not the changes induced by calyculin A or cantharidin. AMPK may thus be activated both by a naringin-sensitive and a naringin-resistant mechanism, probably involving the PPs PP2A and PP1 respectively. Neither the Thr172-phosphorylating protein kinase LKB1 nor the Thr172-dephosphorylating PP, PP2C, were mobility-shifted after treatment with toxins or AICAR, whereas a slight mobility shifting of the regulatory AMPK β-subunit was indicated. Immunoblotting with a phosphospecific antibody against pSer108 at the β-subunit revealed a naringin-sensitive phosphorylation induced by OA, microcystin and AICAR and a naringin-resistant phosphorylation induced by calyculin A and cantharidin, suggesting that β-subunit phosphorylation could play a role in AMPK activation. Naringin antagonized the autophagy-suppressive effects of AICAR and OA, but not the autophagy suppression caused by cantharidin, consistent with AMPK-mediated inhibition of autophagy by toxins as well as by AICAR. PMID:15461583

Inexpensive Audio Activities: Earbud-Based Sound Experiments

ERIC Educational Resources Information Center

Allen, Joshua; Boucher, Alex; Meggison, Dean; Hruby, Kate; Vesenka, James

2016-01-01

Inexpensive alternatives to a number of classic introductory physics sound laboratories are presented including interference phenomena, resonance conditions, and frequency shifts. These can be created using earbuds, economical supplies such as Giant Pixie Stix® wrappers, and free software available for PCs and mobile devices. We describe two…

Importance of Labor in Adoption of a Modern Farm Input.

ERIC Educational Resources Information Center

Ndiaye, Serigne; Sofranko, Andrew J.

1988-01-01

Explores relationship between farm technology and labor availability in Africa. Studies introduction of high-yielding maize variety in Zambia and resulting effects on labor availability/mobilization. Shows shift to hybrids requires additional labor, including available children. Illustrates need for adoption research taking broader farming…

Mobile Laser Scanning for Indoor Modelling

NASA Astrophysics Data System (ADS)

Thomson, C.; Apostolopoulos, G.; Backes, D.; Boehm, J.

2013-10-01

The process of capturing and modelling buildings has gained increased focus in recent years with the rise of Building Information Modelling (BIM). At the heart of BIM is a process change for the construction and facilities management industries whereby a BIM aids more collaborative working through better information exchange, and as a part of the process Geomatic/Land Surveyors are not immune from the changes. Terrestrial laser scanning has been proscribed as the preferred method for rapidly capturing buildings for BIM geometry. This is a process change from a traditional measured building survey just with a total station and is aided by the increasing acceptance of point cloud data being integrated with parametric building models in BIM tools such as Autodesk Revit or Bentley Architecture. Pilot projects carried out previously by the authors to investigate the geometry capture and modelling of BIM confirmed the view of others that the process of data capture with static laser scan setups is slow and very involved requiring at least two people for efficiency. Indoor Mobile Mapping Systems (IMMS) present a possible solution to these issues especially in time saved. Therefore this paper investigates their application as a capture device for BIM geometry creation over traditional static methods through a fit-for-purpose test.

Performance analysis of a compact and low-cost mapping-grade mobile laser scanning system

NASA Astrophysics Data System (ADS)

Julge, Kalev; Vajakas, Toivo; Ellmann, Artu

2017-10-01

The performance of a low-cost, self-contained, compact, and easy to deploy mapping-grade mobile laser scanning (MLS) system, which is composed of a light detection and ranging sensor Velodyne VLP-16 and a dual antenna global navigation satellite system/inertial navigation system SBG Systems Ellipse-D, is analyzed. The field tests were carried out in car-mounted and backpack modes for surveying road engineering structures (such as roads, parking lots, underpasses, and tunnels) and coastal erosion zones, respectively. The impact of applied calculation principles on trajectory postprocessing, direct georeferencing, and the theoretical accuracy of the system is analyzed. A calibration method, based on Bound Optimization BY Quadratic Approximation, for finding the boresight angles of an MLS system is proposed. The resulting MLS point clouds are compared with high-accuracy static terrestrial laser scanning data and survey-grade MLS data from a commercially manufactured MLS system. The vertical, horizontal, and relative accuracy are assessed-the root-mean-square error (RMSE) values were determined to be 8, 15, and 3 cm, respectively. Thus, the achieved mapping-grade accuracy demonstrates that this relatively compact and inexpensive self-assembled MLS can be successfully used for surveying the geometry and deformations of terrain, buildings, road, and other engineering structures.

Correlation of interface states/border traps and threshold voltage shift on AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistors

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

Wu, Tian-Li, E-mail: Tian-Li.Wu@imec.be; Groeseneken, Guido; Department of Electrical Engineering, KU Leuven, Leuven

2015-08-31

In this paper, three electrical techniques (frequency dependent conductance analysis, AC transconductance (AC-g{sub m}), and positive gate bias stress) were used to evaluate three different gate dielectrics (Plasma-Enhanced Atomic Layer Deposition Si{sub 3}N{sub 4}, Rapid Thermal Chemical Vapor Deposition Si{sub 3}N{sub 4}, and Atomic Layer Deposition (ALD) Al{sub 2}O{sub 3}) for AlGaN/GaN Metal-Insulator-Semiconductor High-Electron-Mobility Transistors. From these measurements, the interface state density (D{sub it}), the amount of border traps, and the threshold voltage (V{sub TH}) shift during a positive gate bias stress can be obtained. The results show that the V{sub TH} shift during a positive gate bias stress ismore » highly correlated to not only interface states but also border traps in the dielectric. A physical model is proposed describing that electrons can be trapped by both interface states and border traps. Therefore, in order to minimize the V{sub TH} shift during a positive gate bias stress, the gate dielectric needs to have a lower interface state density and less border traps. However, the results also show that the commonly used frequency dependent conductance analysis technique to extract D{sub it} needs to be cautiously used since the resulting value might be influenced by the border traps and, vice versa, i.e., the g{sub m} dispersion commonly attributed to border traps might be influenced by interface states.« less

Laser-based pedestrian tracking in outdoor environments by multiple mobile robots.

PubMed

Ozaki, Masataka; Kakimuma, Kei; Hashimoto, Masafumi; Takahashi, Kazuhiko

2012-10-29

This paper presents an outdoors laser-based pedestrian tracking system using a group of mobile robots located near each other. Each robot detects pedestrians from its own laser scan image using an occupancy-grid-based method, and the robot tracks the detected pedestrians via Kalman filtering and global-nearest-neighbor (GNN)-based data association. The tracking data is broadcast to multiple robots through intercommunication and is combined using the covariance intersection (CI) method. For pedestrian tracking, each robot identifies its own posture using real-time-kinematic GPS (RTK-GPS) and laser scan matching. Using our cooperative tracking method, all the robots share the tracking data with each other; hence, individual robots can always recognize pedestrians that are invisible to any other robot. The simulation and experimental results show that cooperating tracking provides the tracking performance better than conventional individual tracking does. Our tracking system functions in a decentralized manner without any central server, and therefore, this provides a degree of scalability and robustness that cannot be achieved by conventional centralized architectures.

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

Uin, Janek

The Brechtel Manufacturing Inc. (BMI) Humidified Tandem Differential Mobility Analyzer (HT-DMA Model 3002) (Brechtel and Kreidenweis 2000a,b, Henning et al. 2005, Xerxes et al. 2014) measures how aerosol particles of different initial dry sizes grow or shrink when exposed to changing relative humidity (RH) conditions. It uses two different mobility analyzers (DMA) and a humidification system to make the measurements. One DMA selects a narrow size range of dry aerosol particles, which are exposed to varying RH conditions in the humidification system. The second (humidified) DMA scans the particle size distribution output from the humidification system. Scanning a wide rangemore » of particle sizes enables the second DMA to measure changes in size or growth factor (growth factor = humidified size/dry size), due to water uptake by the particles. A Condensation Particle Counter (CPC) downstream of the second DMA counts particles as a function of selected size in order to obtain the number size distribution of particles exposed to different RH conditions.« less

Performance of cancer cluster Q-statistics for case-control residential histories

PubMed Central

Sloan, Chantel D.; Jacquez, Geoffrey M.; Gallagher, Carolyn M.; Ward, Mary H.; Raaschou-Nielsen, Ole; Nordsborg, Rikke Baastrup; Meliker, Jaymie R.

2012-01-01

Few investigations of health event clustering have evaluated residential mobility, though causative exposures for chronic diseases such as cancer often occur long before diagnosis. Recently developed Q-statistics incorporate human mobility into disease cluster investigations by quantifying space- and time-dependent nearest neighbor relationships. Using residential histories from two cancer case-control studies, we created simulated clusters to examine Q-statistic performance. Results suggest the intersection of cases with significant clustering over their life course, Qi, with cases who are constituents of significant local clusters at given times, Qit, yielded the best performance, which improved with increasing cluster size. Upon comparison, a larger proportion of true positives were detected with Kulldorf’s spatial scan method if the time of clustering was provided. We recommend using Q-statistics to identify when and where clustering may have occurred, followed by the scan method to localize the candidate clusters. Future work should investigate the generalizability of these findings. PMID:23149326

3D modeling of underground objects with the use of SLAM technology on the example of historical mine in Ciechanowice (Ołowiane Range, The Sudetes)

NASA Astrophysics Data System (ADS)

Wajs, Jaroslaw; Kasza, Damian; Zagożdżon, Paweł P.; Zagożdżon, Katarzyna D.

2018-01-01

Terrestrial Laser Scanning is a currently one of the most popular methods for producing representations of 3D objects. This paper presents the potential of applying the mobile laser scanning method to inventory underground objects. The examined location was a historic crystalline limestone mine situated in the vicinity of Ciechanowice village (Kaczawa Mts., SW Poland). The authors present a methodology for performing measurements and for processing the obtained results, whose accuracy is additionally verified.

Functional characterisation of Burkholderia pseudomallei biotin protein ligase: A toolkit for anti-melioidosis drug development.

PubMed

Bond, Thomas E H; Sorenson, Alanna E; Schaeffer, Patrick M

2017-06-01

Burkholderia pseudomallei (Bp) is the causative agent of melioidosis. The bacterium is responsible for 20% of community-acquired sepsis cases and 40% of sepsis-related mortalities in northeast Thailand, and is intrinsically resistant to aminoglycosides, macrolides, rifamycins, cephalosporins, and nonureidopenicillins. There is no vaccine and its diagnosis is problematic. Biotin protein ligase (BirA) which is essential for fatty acid synthesis has been proposed as a drug target in bacteria. Very few bacterial BirA have been characterized, and a better understanding of these enzymes is necessary to further assess their value as drug targets. BirA within the Burkholderia genus have not yet been investigated. We present for the first time the cloning, expression, purification and functional characterisation of the putative Bp BirA and orthologous B. thailandensis (Bt) biotin carboxyl carrier protein (BCCP) substrate. A GFP-tagged Bp BirA was produced and applied for the development of a high-throughput (HT) assay based on our differential scanning fluorimetry of GFP-tagged proteins (DSF-GTP) principle as well as an electrophoretic mobility shift assay. Our biochemical data in combination with the new HT DSF-GTP and biotinylation activity assay could facilitate future drug screening efforts against this drug-resistant organism. Copyright © 2017 Elsevier GmbH. All rights reserved.

The QMAP and MAT/TOCO Experiments for Measuring Anisotropy in the Cosmic Microwave Background

NASA Astrophysics Data System (ADS)

Miller, A.; Beach, J.; Bradley, S.; Caldwell, R.; Chapman, H.; Devlin, M. J.; Dorwart, W. B.; Herbig, T.; Jones, D.; Monnelly, G.; Netterfield, C. B.; Nolta, M.; Page, L. A.; Puchalla, J.; Robertson, T.; Torbet, E.; Tran, H. T.; Vinje, W. E.

2002-06-01

We describe two related experiments that measured the anisotropy in the cosmic microwave background (CMB). QMAP was a balloon-borne telescope that flew twice in 1996, collecting data on degree angular scales with an array of six high electron mobility transistor-based amplifiers (HEMTs). QMAP used an interlocking scan strategy to directly produce high signal-to-noise ratio CMB maps over a limited region of sky. The QMAP gondola was then refitted for ground-based work as the MAT/TOCO experiment. Observations were made from 5200 m on Cerro Toco in Northern Chile in 1997 and 1998 using time domain beam synthesis. MAT/TOCO measured the rise and fall of the CMB angular spectrum, thereby localizing the position of the first peak to lpeak=216+/-14. In addition to describing the instruments, we discuss the data selection methods, check for systematic errors, and compare the MAT/TOCO results to those from recent experiments. The previously reported data are updated to account for a small calibration shift and corrected to account for a small contribution from known sources of foreground emission. The resulting amplitude of the first peak for 160

Flip-flop of hydroxy fatty acids across the membrane as monitored by proton-sensitive microelectrodes.

PubMed

Pohl, Elena E; Voltchenko, Anna M; Rupprecht, Anne

2008-05-01

Hydroxyl group-containing fatty acids play an important role in anti-inflammatory action, neuroprotection, bactericide and anti-cancer defense. However, the mechanism of long-chain hydroxy fatty acids (HFA) transport across plasma membranes is still disputed. Two main hypotheses have been suggested: firstly, that protonated HFAs traverse across the membranes spontaneously and, secondly, that the transport is facilitated by proteinaceous carriers. Here, we demonstrate that the protonated HFA are able to move across planar lipid bilayers without protein assistance. This transport step is accompanied by the acidification of the buffer in receiving compartment and the pH augmentation in the donating compartment. The latter contained liposomes doped with HFA. As revealed by scanning pH-sensitive microelectrodes, the pH shift occurred only in the immediate vicinity of the membrane, while bulk pH remained unchanged. In concurrence with the theoretical model of weak acid transport, the pH value at maximum proton flux was almost equal to the pK of the studied HFA. Intrinsic pKi values were calculated from the electrophoretic mobilities of HFA-containing liposomes and were 5.4, 6.5, 6.9 and 6.3 for 2-hydroxyhexadecanoic, 16-hydroxyhexadecanoic, 12-hydroxydodecanoic and 9,10,16-trihydroxyhexadecanoic acids, respectively.

Correction of phase-shifting error in wavelength scanning digital holographic microscopy

NASA Astrophysics Data System (ADS)

Zhang, Xiaolei; Wang, Jie; Zhang, Xiangchao; Xu, Min; Zhang, Hao; Jiang, Xiangqian

2018-05-01

Digital holographic microscopy is a promising method for measuring complex micro-structures with high slopes. A quasi-common path interferometric apparatus is adopted to overcome environmental disturbances, and an acousto-optic tunable filter is used to obtain multi-wavelength holograms. However, the phase shifting error caused by the acousto-optic tunable filter reduces the measurement accuracy and, in turn, the reconstructed topographies are erroneous. In this paper, an accurate reconstruction approach is proposed. It corrects the phase-shifting errors by minimizing the difference between the ideal interferograms and the recorded ones. The restriction on the step number and uniformity of the phase shifting is relaxed in the interferometry, and the measurement accuracy for complex surfaces can also be improved. The universality and superiority of the proposed method are demonstrated by practical experiments and comparison to other measurement methods.

Development of scanning graphene Hall probes for magnetic microscopy

NASA Astrophysics Data System (ADS)

Schaefer, Brian T.; Wang, Lei; McEuen, Paul L.; Nowack, Katja C.

We discuss our progress on developing scanning Hall probes fabricated from hexagonal boron nitride (hBN)-encapsulated graphene, with the goal to image magnetic fields with submicron resolution. In contrast to scanning superconducting quantum interference device (SQUID) microscopy, this technique is compatible with a large applied magnetic field and not limited to cryogenic temperatures. The field sensitivity of a Hall probe depends inversely on carrier density, while the primary source of noise in the measurement is Johnson noise originating from the device resistance. hBN-encapsulated graphene demonstrates high carrier mobility at low carrier densities, therefore making it an ideal material for sensitive Hall probes. Furthermore, engineering the dielectric environment of graphene by encapsulating in hBN reduces low-frequency charge noise and disorder from the substrate. We outline our plans for adapting these devices for scanning, including characterization of the point spread function with a scanned current loop and fabrication of a deep-etched structure that enables positioning the sensitive area within 100 nanometers of the sample surface.

Childhood Family Structure and Intergenerational Income Mobility in the United States.

PubMed

Bloome, Deirdre

2017-04-01

The declining prevalence of two-parent families helped increase income inequality over recent decades. Does family structure also condition how economic (dis)advantages pass from parents to children? If so, shifts in the organization of family life may contribute to enduring inequality between groups defined by childhood family structure. Using National Longitudinal Survey of Youth data, I combine parametric and nonparametric methods to reveal how family structure moderates intergenerational income mobility in the United States. I find that individuals raised outside stable two-parent homes are much more mobile than individuals from stable two-parent families. Mobility increases with the number of family transitions but does not vary with children's time spent coresiding with both parents or stepparents conditional on a transition. However, this mobility indicates insecurity, not opportunity. Difficulties maintaining middle-class incomes create downward mobility among people raised outside stable two-parent homes. Regardless of parental income, these people are relatively likely to become low-income adults, reflecting a new form of perverse equality. People raised outside stable two-parent families are also less likely to become high-income adults than people from stable two-parent homes. Mobility differences account for about one-quarter of family-structure inequalities in income at the bottom of the income distribution and more than one-third of these inequalities at the top.

Firm size distribution and mobility of the top 500 firms in China, the United States and the world

NASA Astrophysics Data System (ADS)

Guo, Jinzhong; Xu, Qi; Chen, Qinghua; Wang, Yougui

2013-07-01

This paper considers the macroscopic and microscopic statistical features of the top 500 firms in China, the United States and the world, denoted as China 500 (CH500), Fortune 500 (US500) and Fortune Global 500 (FG500). From a macroscopic perspective, the firm size distribution of each category, when measured by revenue, is steadily distributed over the observed period, even during periods of financial crises. As is evidenced by the Gini coefficient, divergences between firm scales are most significant for the CH500. From a microscopic perspective, the underlying micro-dynamics are volatile and often turbulent due to the exit and entry of firms as well as shifts in their revenues and ranks. Such fluctuations, or mobility, are visualized in rank/revenue/share clocks. We also propose a revenue/rank/share mobility index that is a quantitative measurement of mobility. Among these, we find that the share mobility acts as an effective indicator of economic status; where there is a share mobility spike, there is an ailing economy. The share mobility indexes indicate that the 2008 Financial Crisis had little impact on the Chinese economy, while it triggered violent changes in the top 500 firms in the United States and the world.

Changes in urination according to the sound of running water using a mobile phone application.

PubMed

Kwon, Whi-An; Kim, Sung Han; Kim, Sohee; Joung, Jae Young; Chung, Jinsoo; Lee, Kang Hyun; Lee, Sang-Jin; Seo, Ho Kyung

2015-01-01

The sound of running water (SRW) has been effectively used for toilet training during toddlerhood. However, the effect of SRW on voiding functions in adult males with lower urinary tract symptoms (LUTS) has not been evaluated. To determine the effect of SRW on urination in male patients with LUTS, multiple voiding parameters of uroflowmetry with postvoid residual urine (PVR) were assessed according to the presence of SRW played by a mobile application. Eighteen consecutive male patients with LUTS were prospectively enrolled between March and April 2014. Uroflowmetry with PVR measured by a bladder scan was randomly performed once weekly for two consecutive weeks with and without SRW in a completely sealed room after pre-checked bladder volume was scanned to be more than 150 cc. SRW was played with river water sounds amongst relaxed melodies from a smartphone mobile application. The mean age of enrolled patients and their mean International Prostate Symptom Score (IPSS) were 58.9 ± 7.7 years (range: 46-70) and 13.1 ± 5.9, respectively. All patients had not been prescribed any medications, including alpha-blockers or anti-muscarinic agents, in the last 3 months. There was a significant increase in mean peak flow rate (PFR) with SRW in comparison to without SRW (15.7 mL/s vs. 12.3 mL/s, respectively, p = 0.0125). However, there were no differences in other uroflowmetric parameters, including PVR. The study showed that SRW from a mobile phone application may be helpful in facilitating voiding functions by increasing PFR in male LUTS patients.

Scanning Tunneling Spectroscopy of Potassium on Graphene

NASA Astrophysics Data System (ADS)

Cormode, Daniel; Leroy, Brian; Yankowitz, Matthew

2012-02-01

We investigate the effect of charged impurities on the electronic properties of large single crystal CVD grown graphene using scanning tunneling microscopy. Mono- and multilayer crystals were prepared by transferring graphene from copper onto exfoliated boron nitride flakes on 300 nm SiO2 substrates. The boron nitride provides an ultra flat surface for the graphene. Potassium atoms are controllably deposited on the graphene at low temperature by heating a nearby getter source. Scanning tunneling spectroscopy and transport measurements were performed in ultra high vacuum at 4.5 K. Transport measurements demonstrate the shifting of the Dirac point as the samples are doped, while STM measurements demonstrate the size, arrangement and local electronic influence of the potassium atoms.

Body Composition Remodeling and Incident Mobility Limitations in African Ancestry Men.

PubMed

Santanasto, Adam J; Miljkovic, Iva; Cvejkus, Ryan C; Gordon, Christopher L; Bunker, Clareann H; Patrick, Allen L; Wheeler, Victor W; Zmuda, Joseph M

2018-04-05

Mobility limitations are common, with higher prevalence in African Americans compared to whites, and are associated with disability, institutionalization and death. Aging is associated with losses of lean mass and a shift to central adiposity, which are more pronounced in African Americans. We aimed to examine the association of body composition remodeling with incident mobility limitations in older men of African Ancestry. Seven-year changes in body composition were measured using peripheral computed tomography (pQCT) of the calf and whole-body dual x-ray absorptiometry (DXA) in 505 African Ancestry men aged ≥60 years and free of self-reported mobility limitations at baseline. Self-reported incident mobility limitations were assessed at 7-year follow-up. Odds of developing mobility limitations associated with baseline and change in body composition were quantified using separate logistic regression models. Seventy-five men (14.9%) developed incident mobility limitations over 6.2±0.6 years. Baseline body composition was not associated with incident mobility limitations. After adjustment for covariates, gaining total and intermuscular fat were associated with incident mobility limitations a (OR: 1.60; 95% CI: 1.21-2.13; OR: 1.51; 95% CI: 1.18-1.94). Changes in DXA lean mass were not related to mobility limitations; however, maintaining pQCT calf muscle area was protective against mobility limitations (OR: 0.65; 95% CI: 0.48-0.87). Increases in body fat, and particularly intermuscular fat, and decreases in calf skeletal muscle were associated with a higher risk of developing mobility limitations. Our findings emphasize the importance of body composition remodeling in the development of mobility limitations among African ancestry men.

Public Sector Transformation, Racial Inequality and Downward Occupational Mobility

ERIC Educational Resources Information Center

Wilson, George; Roscigno, Vincent J.; Huffman, Matt L.

2013-01-01

New "governance" reforms entailing shifts toward privatization have permeated the public sector over the last decade, possibly affecting workplace-based attainments. We examine the consequences of this reform for African American men, who during the civil rights era reached relative parity with whites. We analyze race-based inequities on one…

Educational Exceptionalism in Small (and Micro) States: Cooperative Educational Transfer and TVET

ERIC Educational Resources Information Center

Jules, Tavis D.

2015-01-01

Since 2002, the 15 member states of the Caribbean Community (CARICOM) have shifted human resource development reforms from focusing on providing basic, mass primary and secondary education and limited tertiary education toward diverting resources to "Technical and Vocational Education and Training" (TVET) to accommodate labor mobility.…

Reconceptualizing the Nature of Goals and Outcomes in Language/s Education

ERIC Educational Resources Information Center

Leung, Constant; Scarino, Angela

2016-01-01

Transformations associated with the increasing speed, scale, and complexity of mobilities, together with the information technology revolution, have changed the demography of most countries of the world and brought about accompanying social, cultural, and economic shifts (Heugh, 2013). This complex diversity has changed the very nature of…

Peer Communication through Blogging

ERIC Educational Resources Information Center

Wall, Steven D.; Anderson, Janice

2015-01-01

With the emergence of mobile technologies, students' access to computing devices is omnipresent, as is their ability to collaborate through multiple modalities. This 21st-century affordance has generated a shift in the way preservice teachers are prepared to use, understand. and interact with social media (e.g., blogs) during their academic years.…

Macroscopic experimental and modeling evaluation of selenite and selenate adsorption mechanisms on gibbsite

USDA-ARS?s Scientific Manuscript database

Selenite Se(IV) and selenate Se(VI) selenium adsorption behavior was investigated on gibbsite as a function of solution pH and solution ionic strength. Adsorption of both Se redox states decreased with increasing solution pH. Electrophoretic mobility measurements showed downward shifts in point of...

The Shifting Geography of Urban Education

ERIC Educational Resources Information Center

Freeman, Eric

2010-01-01

Poverty in the United States is migrating far beyond the urban core and transforming the suburbs into places increasingly stratified by income, wealth, opportunity, and education. Census data from the 2005 American Community Survey reveal new patterns of income inequality, residential mobility, and spatial segregation that make the suburbs less of…

Trends in Higher Education. Volume 2: Faculty

ERIC Educational Resources Information Center

Association of Universities and Colleges of Canada, 2007

2007-01-01

This volume of "Trends" provides a historical analysis of faculty hiring over the last 30 years, with breakdowns that examine nationwide shifts in gender, age, mobility and attrition as well as within specific disciplines. Following this analysis is a discussion of the factors that will drive change in faculty renewal for the…

Globalisation and Higher Education: From Within-Border to Cross-Border

ERIC Educational Resources Information Center

Youssef, Leïla

2014-01-01

Globalisation, the shift to a knowledge economy, and changing demographics are increasingly challenging higher education systems. The move from elite through mass to universal education, coupled with the internationalisation of higher education, has profoundly influenced the system, especially in terms of academic mobility. It has created new…

Changing Directions: The Future of Associate Degree Nursing.

ERIC Educational Resources Information Center

Dillon, Patricia

1997-01-01

The majority of current nursing graduates are associate degree nurses (ADNs). However, recent trends, such as the shift to a worldwide health care market and community/primary care, suggest that a bachelor's degree is better preparation. Ways to increase the mobility of ADNs into bachelor's degree programs are needed. (SK)

Digital Literacy: Tools and Methodologies for Information Society

ERIC Educational Resources Information Center

Rivoltella, Pier Cesare, Ed.

2008-01-01

Currently in a state of cultural transition, global society is moving from a literary society to digital one, adopting widespread use of advanced technologies such as the Internet and mobile devices. Digital media has an extraordinary impact on society's formative processes, forcing a pragmatic shift in their management and organization. This…

iTESOL: Analogous Practices in the SLA Classroom

ERIC Educational Resources Information Center

McDonald, Lisa

2010-01-01

Recent studies of emerging technologies have shown that mobile phone production now exceeds one billion devices globally per year (Johnson, Levine & Smith, 2008). With a level of production that signifies a shift in the ownership of "networked machines" from institutions to individuals, the broad appeal of portable technologies now offers…

Geographic Mobility of Manpower in the USSR.

ERIC Educational Resources Information Center

Kossov, V. V.; Tatevosoc, R. V.

1984-01-01

The Soviet Union is experiencing substantial reduction in the growth of the working-age population, accompanied by a shift in the distribution of population growth. The government is using various means to encourage workers to move to the sparsely populated developing regions and away from the large cities. (SK)

L2-Proficiency-Dependent Laterality Shift in Structural Connectivity of Brain Language Pathways.

PubMed

Xiang, Huadong; van Leeuwen, Tessa Marije; Dediu, Dan; Roberts, Leah; Norris, David G; Hagoort, Peter

2015-08-01

Diffusion tensor imaging (DTI) and a longitudinal language learning approach were applied to investigate the relationship between the achieved second language (L2) proficiency during L2 learning and the reorganization of structural connectivity between core language areas. Language proficiency tests and DTI scans were obtained from German students before and after they completed an intensive 6-week course of the Dutch language. In the initial learning stage, with increasing L2 proficiency, the hemispheric dominance of the Brodmann area (BA) 6-temporal pathway (mainly along the arcuate fasciculus) shifted from the left to the right hemisphere. With further increased proficiency, however, lateralization dominance was again found in the left BA6-temporal pathway. This result is consistent with reports in the literature that imply a stronger involvement of the right hemisphere in L2 processing especially for less proficient L2 speakers. This is the first time that an L2 proficiency-dependent laterality shift in the structural connectivity of language pathways during L2 acquisition has been observed to shift from left to right and back to left hemisphere dominance with increasing L2 proficiency. The authors additionally find that changes in fractional anisotropy values after the course are related to the time elapsed between the two scans. The results suggest that structural connectivity in (at least part of) the perisylvian language network may be subject to fast dynamic changes following language learning.

Effects of Frequency Drift on the Quantification of Gamma-Aminobutyric Acid Using MEGA-PRESS

NASA Astrophysics Data System (ADS)

Tsai, Shang-Yueh; Fang, Chun-Hao; Wu, Thai-Yu; Lin, Yi-Ru

2016-04-01

The MEGA-PRESS method is the most common method used to measure γ-aminobutyric acid (GABA) in the brain at 3T. It has been shown that the underestimation of the GABA signal due to B0 drift up to 1.22 Hz/min can be reduced by post-frequency alignment. In this study, we show that the underestimation of GABA can still occur even with post frequency alignment when the B0 drift is up to 3.93 Hz/min. The underestimation can be reduced by applying a frequency shift threshold. A total of 23 subjects were scanned twice to assess the short-term reproducibility, and 14 of them were scanned again after 2-8 weeks to evaluate the long-term reproducibility. A linear regression analysis of the quantified GABA versus the frequency shift showed a negative correlation (P < 0.01). Underestimation of the GABA signal was found. When a frequency shift threshold of 0.125 ppm (15.5 Hz or 1.79 Hz/min) was applied, the linear regression showed no statistically significant difference (P > 0.05). Therefore, a frequency shift threshold at 0.125 ppm (15.5 Hz) can be used to reduce underestimation during GABA quantification. For data with a B0 drift up to 3.93 Hz/min, the coefficients of variance of short-term and long-term reproducibility for the GABA quantification were less than 10% when the frequency threshold was applied.

Quantum oscillations in a topological insulator Bi2Te2Se with large bulk resistivity (6 Ω cm)

NASA Astrophysics Data System (ADS)

Xiong, Jun; Petersen, A. C.; Qu, Dongxia; Hor, Y. S.; Cava, R. J.; Ong, N. P.

2012-02-01

We report the observation of prominent Shubnikov-de Haas oscillations in a Topological Insulator, Bi2Te2Se, with large bulk resistivity (6 Ω cm at 4 K). By fitting the SdH oscillations, we infer a large metallicity parameter kFℓ=41, with a surface mobility (μs∼2800 cm2/V s) much larger than the bulk mobility (μb∼50 cm2/V s). The plot of the index fields Bν vs. filling factor ν shows a {1}/{2}-shift, consistent with massless, Dirac states.

Adding Value to the Network: Exploring the Software as a Service and Platform as a Service Models for Mobile Operators

NASA Astrophysics Data System (ADS)

Gonçalves, Vânia

The environments of software development and software provision are shifting to Web-based platforms supported by Platform/Software as a Service (PaaS/SaaS) models. This paper will make the case that there is equally an opportunity for mobile operators to identify additional sources of revenue by exposing network functionalities through Web-based service platforms. By elaborating on the concepts, benefits and risks of SaaS and PaaS, several factors that should be taken into consideration in applying these models to the telecom world are delineated.

Analysis of Carina Position as Surrogate Marker for Delivering Phase-Gated Radiotherapy

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

Weide, Lineke van der; Soernsen de Koste, John R. van; Lagerwaard, Frank J.

2008-07-15

Purpose: Respiratory gating can mitigate the effect of tumor mobility in radiotherapy (RT) for lung cancer. Because the tumor is generally not visualized, external surrogates of tumor position are used to trigger respiration-gated RT. We evaluated the suitability of the carina position as a surrogate in respiration-gated RT. Methods and Materials: A total of 30 four-dimensional (4D) computed tomography (CT) scans from 14 patients with lung cancer were retrospectively analyzed. Both uncoached (free breathing) and audio-coached 4D-CT scans were acquired from 9 patients, and 12 uncoached 4D-CT scans were acquired from 5 other patients during a 2-4-week period of stereotacticmore » RT. The repeat scans were co-registered. The carina position was identified on the coronal cut planes in all 4D-CT phases. The correlation between the carina position and the total lung volume for each phase was determined, and the reproducibility of the carina position was studied in the 5 patients with repeat uncoached 4D-CT scans. Results: The mean extent of carina motion in 21 uncoached scans was 5.3 {+-} 1.6 mm in the craniocaudal (CC), 2.3 {+-} 1.4 mm in the anteroposterior, and 1.5 {+-} 0.7 mm in the mediolateral direction. Audio coaching resulted in a twofold increase in carina mobility in all directions. The CC carina position correlated with changes in the total lung volume (R = 0.89 {+-} 0.14), but the correlation was better for the audio-coached than for the uncoached 4D-CT scans (R = 0.93 {+-} 0.08 vs. R = 0.85 {+-} 0.17; paired t test, p = 0.034). Preliminary data from the 5 patients indicated that the CC carina motion correlated better with tumor motion than did the motion of the diaphragm. Conclusions: The CC position of the carina correlated well with the total lung volume, indicating that the carina is a good surrogate for verifying the total lung volume during respiration-gated RT.« less

Positron transport studies at the Au - (InP:Fe) interface

NASA Astrophysics Data System (ADS)

Au, H. L.; Lee, T. C.; Beling, C. D.; Fung, S.

1996-03-01

Positron mobility and lifetime measurements have been carried out on semi-insulating Fe-doped InP samples with Au contacts used for electric field application. The lifetime measurements, with electric fields directed towards the Au - InP:Fe interface, reveal no component associated with interfacial open-volume sites and thus give no evidence of any positron mobility. The mobility measurements, made using the Doppler-shifted annihilation radiation technique, however, reveal a temperature independent positron mobility of about 0953-8984/8/10/012/img1 in the range 150 - 300 K. These observations, together with results from I - V analysis, are discussed with reference to two possible band-bending schemes. The first, which requires an ionized shallow donor region adjacent to the Au - InP interface, seems less plausible on a number of grounds. In the second, however, an 0953-8984/8/10/012/img2 negative space charge produces an adverse diffusion barrier for positrons approaching the interface together with a non-uniform electric field in the samples capable of explaining the observed mobility results.

Solution-Processed Donor-Acceptor Polymer Nanowire Network Semiconductors For High-Performance Field-Effect Transistors

PubMed Central

Lei, Yanlian; Deng, Ping; Li, Jun; Lin, Ming; Zhu, Furong; Ng, Tsz-Wai; Lee, Chun-Sing; Ong, Beng S.

2016-01-01

Organic field-effect transistors (OFETs) represent a low-cost transistor technology for creating next-generation large-area, flexible and ultra-low-cost electronics. Conjugated electron donor-acceptor (D-A) polymers have surfaced as ideal channel semiconductor candidates for OFETs. However, high-molecular weight (MW) D-A polymer semiconductors, which offer high field-effect mobility, generally suffer from processing complications due to limited solubility. Conversely, the readily soluble, low-MW D-A polymers give low mobility. We report herein a facile solution process which transformed a lower-MW, low-mobility diketopyrrolopyrrole-dithienylthieno[3,2-b]thiophene (I) into a high crystalline order and high-mobility semiconductor for OFETs applications. The process involved solution fabrication of a channel semiconductor film from a lower-MW (I) and polystyrene blends. With the help of cooperative shifting motion of polystyrene chain segments, (I) readily self-assembled and crystallized out in the polystyrene matrix as an interpenetrating, nanowire semiconductor network, providing significantly enhanced mobility (over 8 cm2V−1s−1), on/off ratio (107), and other desirable field-effect properties that meet impactful OFET application requirements. PMID:27091315

Piezoelectric scattering limited mobility of hybrid organic-inorganic perovskites CH3NH3PbI3

PubMed Central

Lu, Ying-Bo; Kong, Xianghua; Chen, Xiaobin; Cooke, David G.; Guo, Hong

2017-01-01

Carrier mobility is one of the most important parameters for semiconducting materials and their use in optoelectronic devices. Here we report a systematic first principles analysis of the acoustic phonon scattering mechanism that limits the mobility of CH3NH3PbI3 (MAPbI3) perovskites. Due to the unique hybrid organic-inorganic structure, the mechanical, electronic and transport properties are dominated by the same factor, i.e. the weak interatomic bond and the easy rotation of methylammonium (MA) molecules under strain. Both factors make MAPbI3 soft. Rotation of MA molecule induces a transverse shift between Pb and I atoms, resulting in a very low deformation potential and a strong piezoelectricity in MAPbI3. Hence the carrier mobility of pristine MAPbI3 is limited by the piezoelectric scattering, which is consistent to the form of its temperature dependence. Our calculations suggest that in the pristine limit, a high mobility of about several thousand cm2 V−1 S−1 is expected for MAPbI3. PMID:28150743

Improving vaccine registries through mobile technologies: a vision for mobile enhanced Immunization information systems.

PubMed

Wilson, Kumanan; Atkinson, Katherine M; Deeks, Shelley L; Crowcroft, Natasha S

2016-01-01

Immunization registries or information systems are critical to improving the quality and evaluating the ongoing success of immunization programs. However, the completeness of these systems is challenged by a myriad of factors including the fragmentation of vaccine administration, increasing mobility of individuals, new vaccine development, use of multiple products, and increasingly frequent changes in recommendations. Mobile technologies could offer a solution, which mitigates some of these challenges. Engaging individuals to have more control of their own immunization information using their mobile devices could improve the timeliness and accuracy of data in central immunization information systems. Other opportunities presented by mobile technologies that could be exploited to improve immunization information systems include mobile reporting of adverse events following immunization, the capacity to scan 2D barcodes, and enabling bidirectional communication between individuals and public health officials. Challenges to utilizing mobile solutions include ensuring privacy of data, access, and equity concerns, obtaining consent and ensuring adoption of technology at sufficiently high rates. By empowering individuals with their own health information, mobile technologies can also serve as a mechanism to transfer immunization information as individuals cross local, regional, and national borders. Ultimately, mobile enhanced immunization information systems can help realize the goal of the individual, the healthcare provider, and public health officials always having access to the same immunization information. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Sexual Orientation-Related Differences in Virtual Spatial Navigation and Spatial Search Strategies.

PubMed

Rahman, Qazi; Sharp, Jonathan; McVeigh, Meadhbh; Ho, Man-Ling

2017-07-01

Spatial abilities are generally hypothesized to differ between men and women, and people with different sexual orientations. According to the cross-sex shift hypothesis, gay men are hypothesized to perform in the direction of heterosexual women and lesbian women in the direction of heterosexual men on cognitive tests. This study investigated sexual orientation differences in spatial navigation and strategy during a virtual Morris water maze task (VMWM). Forty-four heterosexual men, 43 heterosexual women, 39 gay men, and 34 lesbian/bisexual women (aged 18-54 years) navigated a desktop VMWM and completed measures of intelligence, handedness, and childhood gender nonconformity (CGN). We quantified spatial learning (hidden platform trials), probe trial performance, and cued navigation (visible platform trials). Spatial strategies during hidden and probe trials were classified into visual scanning, landmark use, thigmotaxis/circling, and enfilading. In general, heterosexual men scored better than women and gay men on some spatial learning and probe trial measures and used more visual scan strategies. However, some differences disappeared after controlling for age and estimated IQ (e.g., in visual scanning heterosexual men differed from women but not gay men). Heterosexual women did not differ from lesbian/bisexual women. For both sexes, visual scanning predicted probe trial performance. More feminine CGN scores were associated with lower performance among men and greater performance among women on specific spatial learning or probe trial measures. These results provide mixed evidence for the cross-sex shift hypothesis of sexual orientation-related differences in spatial cognition.

Data-driven gating in PET: Influence of respiratory signal noise on motion resolution.

PubMed

Büther, Florian; Ernst, Iris; Frohwein, Lynn Johann; Pouw, Joost; Schäfers, Klaus Peter; Stegger, Lars

2018-05-21

Data-driven gating (DDG) approaches for positron emission tomography (PET) are interesting alternatives to conventional hardware-based gating methods. In DDG, the measured PET data themselves are utilized to calculate a respiratory signal, that is, subsequently used for gating purposes. The success of gating is then highly dependent on the statistical quality of the PET data. In this study, we investigate how this quality determines signal noise and thus motion resolution in clinical PET scans using a center-of-mass-based (COM) DDG approach, specifically with regard to motion management of target structures in future radiotherapy planning applications. PET list mode datasets acquired in one bed position of 19 different radiotherapy patients undergoing pretreatment [ 18 F]FDG PET/CT or [ 18 F]FDG PET/MRI were included into this retrospective study. All scans were performed over a region with organs (myocardium, kidneys) or tumor lesions of high tracer uptake and under free breathing. Aside from the original list mode data, datasets with progressively decreasing PET statistics were generated. From these, COM DDG signals were derived for subsequent amplitude-based gating of the original list mode file. The apparent respiratory shift d from end-expiration to end-inspiration was determined from the gated images and expressed as a function of signal-to-noise ratio SNR of the determined gating signals. This relation was tested against additional 25 [ 18 F]FDG PET/MRI list mode datasets where high-precision MR navigator-like respiratory signals were available as reference signal for respiratory gating of PET data, and data from a dedicated thorax phantom scan. All original 19 high-quality list mode datasets demonstrated the same behavior in terms of motion resolution when reducing the amount of list mode events for DDG signal generation. Ratios and directions of respiratory shifts between end-respiratory gates and the respective nongated image were constant over all statistic levels. Motion resolution d/d max could be modeled as d/dmax=1-e-1.52(SNR-1)0.52, with d max as the actual respiratory shift. Determining d max from d and SNR in the 25 test datasets and the phantom scan demonstrated no significant differences to the MR navigator-derived shift values and the predefined shift, respectively. The SNR can serve as a general metric to assess the success of COM-based DDG, even in different scanners and patients. The derived formula for motion resolution can be used to estimate the actual motion extent reasonably well in cases of limited PET raw data statistics. This may be of interest for individualized radiotherapy treatment planning procedures of target structures subjected to respiratory motion. © 2018 American Association of Physicists in Medicine.

Flat Terahertz Reflective Focusing Metasurface with Scanning Ability.

PubMed

Yi, Huan; Qu, Shi-Wei; Chen, Bao-Jie; Bai, Xue; Ng, Kung Bo; Chan, Chi Hou

2017-06-14

The ability to manipulate the propagation properties of electromagnetic waves, e.g., divergence, focusing, holography or deflection, is very significant in terahertz applications. Metasurfaces with flat structures are attractive for achieving such manipulations in terahertz band, as they feature low profile, lightweight, and ease of design and installation. Several types of terahertz reflective or transmitting metasurfaces with focusing function have been implemented recently, but none of them can provide scanning ability with controllable focus. Here, a flat reflective metasurface featuring controllable focal shift is proposed and experimentally demonstrated. Furthermore, the principle of designing a focus scanning reflective metasurface is presented and the focusing characteristics are discussed, including focus scanning along a line parallel or orthogonal to the metasurface with a large bandwidth. These interesting properties indicate that this flat reflective metasurface could play a key role in many terahertz imaging and detection systems.

Responses of Roadside Soil Cation Pools to Vehicular Emission Deposition in Southern California

NASA Astrophysics Data System (ADS)

Rossi, R.; Bain, D. J.; Jenerette, D.; Clarke, L. W.; Wilson, K.

2013-12-01

Roadside soils are heavily loaded with NO3- due to vehicular emissions. This deposition likely acidifies these soils, potentially mobilizing cationic species from soil exchange sites. Acidification driven mobilization is well documented in forest soils, but poorly understood in roadside soils. Metal concentrations in park and garden soils collected from Southern California were examined across gradients of soil chemistry, road network density, climate, and geology to examine cation mobilization effects. In our samples, soil pH is not clearly related to distance from the roadside or underlying geology. However, the depletion of several elements (Al, K) is clearly observed in near-road environments. These depletion trends occur despite contrary trends, including increased soil surface areas and soil organic matter in near-road environments. Additionally, inputs from the weathering of road building materials appear to affect soil chemistry. For example, soil Ca patterns remain relatively consistent relative to roads, suggesting Ca bearing weathering products replenish soil Ca pools in near-road areas. Simple mixing models constructed using elemental ratios are consistent with road material Ca source contributions. Observed near-road patterns in soil chemistry likely influence local ecological function, shifting plant communities and soil functions. Clear understanding of these shifts is essential to the effective use of green infrastructure and other strategies utilized to control road-sourced nutrients. This analytical framework can be applied globally as road networks continue to expand and affect larger ecosystems.

Molecular weight dependent charge carrier mobility in poly(3,3' '-dioctyl-2,2':5',2' '-terthiophene).

PubMed

Verilhac, Jean-Marie; Pokrop, Rafal; LeBlevennec, Gilles; Kulszewicz-Bajer, Irena; Buga, Katarzyna; Zagorska, Malgorzata; Sadki, Said; Pron, Adam

2006-07-13

Poly(3,3' '-dioctyl-2,2':5',2' '-terthiophene), a polymer recently used for the fabrication of organic field effect transistors, has been fractionated into five fractions distinctly differing in their molecular weights (Mn), with the goal of determining the influence of the degree of polymerization (DPn) on its principal physicochemical parameters. It has been demonstrated that within the Mn range studied (from 1.5 kDa to 10.5 kDa by SEC), corresponding to DPn from 10 to 38, the polymer band gap steadily decreases with growing molecular weight, which is clearly manifested by an increasing bathochromic shift of the band originating from the pi-pi* transition. The same trend is observed for the HOMO level, determined from the onset of the p-doping in cyclic voltammetry, which shifts from -5.10 eV to -4.90 eV for the lowest and the highest molecular weight fractions, respectively. The most pronounced influence of DPn has been found for the charge carriers' mobility-one of the most important parameters of field effect transistors (FETs) fabricated from this polymer. A fourfold increase in DPn results in an increase of the carriers' mobility by more than 3 orders of magnitude. Comparison of these results with those obtained for fractionated regioregular poly(3-hexylthiophene) shows a strikingly similar behavior of both polymers with respect to the molecular weight.

Performance of a scanning mobility particle sizer in measuring diverse types of airborne nanoparticles: Multi-walled carbon nanotubes, welding fumes, and titanium dioxide spray.

PubMed

Chen, Bean T; Schwegler-Berry, Diane; Cumpston, Amy; Cumpston, Jared; Friend, Sherri; Stone, Samuel; Keane, Michael

2016-07-01

Direct-reading instruments have been widely used for characterizing airborne nanoparticles in inhalation toxicology and industrial hygiene studies for exposure/risk assessments. Instruments using electrical mobility sizing followed by optical counting, e.g., scanning or sequential mobility particle spectrometers (SMPS), have been considered as the "gold standard" for characterizing nanoparticles. An SMPS has the advantage of rapid response and has been widely used, but there is little information on its performance in assessing the full spectrum of nanoparticles encountered in the workplace. In this study, an SMPS was evaluated for its effectiveness in producing "monodisperse" aerosol and its adequacy in characterizing overall particle size distribution using three test aerosols, each mimicking a unique class of real-life nanoparticles: singlets of nearly spherical titanium dioxide (TiO2), agglomerates of fiber-like multi-walled carbon nanotube (MWCNT), and aggregates that constitutes welding fume (WF). These aerosols were analyzed by SMPS, cascade impactor, and by counting and sizing of discrete particles by scanning and transmission electron microscopy. The effectiveness of the SMPS to produce classified particles (fixed voltage mode) was assessed by examination of the resulting geometric standard deviation (GSD) from the impactor measurement. Results indicated that SMPS performed reasonably well for TiO2 (GSD = 1.3), but not for MWCNT and WF as evidenced by the large GSD values of 1.8 and 1.5, respectively. For overall characterization, results from SMPS (scanning voltage mode) exhibited particle-dependent discrepancies in the size distribution and total number concentration compared to those from microscopic analysis. Further investigation showed that use of a single-stage impactor at the SMPS inlet could distort the size distribution and underestimate the concentration as shown by the SMPS, whereas the presence of vapor molecules or atom clusters in some test aerosols might cause artifacts by counting "phantom particles." Overall, the information obtained from this study will help understand the limitations of the SMPS in measuring nanoparticles so that one can adequately interpret the results for risk assessments and exposure prevention in an occupational or ambient environment.

Discriminant analysis of fused positive and negative ion mobility spectra using multivariate self-modeling mixture analysis and neural networks.

PubMed

Chen, Ping; Harrington, Peter B

2008-02-01

A new method coupling multivariate self-modeling mixture analysis and pattern recognition has been developed to identify toxic industrial chemicals using fused positive and negative ion mobility spectra (dual scan spectra). A Smiths lightweight chemical detector (LCD), which can measure positive and negative ion mobility spectra simultaneously, was used to acquire the data. Simple-to-use interactive self-modeling mixture analysis (SIMPLISMA) was used to separate the analytical peaks in the ion mobility spectra from the background reactant ion peaks (RIP). The SIMPLSIMA analytical components of the positive and negative ion peaks were combined together in a butterfly representation (i.e., negative spectra are reported with negative drift times and reflected with respect to the ordinate and juxtaposed with the positive ion mobility spectra). Temperature constrained cascade-correlation neural network (TCCCN) models were built to classify the toxic industrial chemicals. Seven common toxic industrial chemicals were used in this project to evaluate the performance of the algorithm. Ten bootstrapped Latin partitions demonstrated that the classification of neural networks using the SIMPLISMA components was statistically better than neural network models trained with fused ion mobility spectra (IMS).

Effect of transient wave forcing on the behavior of arsenic in a sandy nearshore aquifer

NASA Astrophysics Data System (ADS)

Rakhimbekova, S.; O'Carroll, D. M.; Robinson, C. E.

2016-12-01

Waves cause large quantities of coastal water to recirculate across the groundwater-coastal water interface in addition to inducing complex groundwater flows in the nearshore aquifer. Due to the distinct chemical composition of recirculating coastal water compared with discharging terrestrial groundwater, wave-induced recirculations and flows can alter geochemical gradients in the nearshore aquifer which may subsequently affect the mobilization and transport of reactive pollutants (e.g., arsenic). The impact of seasonal geochemical and hydrological variability on the occurrence and mobility of arsenic near the groundwater-surface water interface has been shown previously in riverine settings, however, the impact of high frequency geochemical variations (e.g., varying wave conditions) on arsenic mobility in groundwater-surface water environments is unclear. The objective of the study was to assess the impact of intensified wave conditions on the behavior of arsenic in a nearshore aquifer to determine the factors regulating its mobility and transport to receiving coastal waters. Field investigations were conducted at a permeable beach on the Great Lakes during a period of intensified wave conditions (wave event). High spatial resolution pore water sampling captured the geochemical conditions in the nearshore aquifer prior to the wave event, immediately after the wave event and over a recovery period of 3 weeks following the wave event. Shifts in pH and redox potential (ORP) gradients in response to varying wave conditions caused shifts in the iron and arsenic distributions in the aquifer. Sediment analysis was combined with the pore water distributions to assess the release of sediment-bound arsenic in response to the varying wave conditions. Insight into the effect of transient forcing on arsenic mobility and transport in groundwater-surface water environments is important for evaluating the potential risks associated with this toxic metalloid. The findings of this study also have significant implications for the fate of other reactive constituents (heavy metals, nutrients) discharging through nearshore aquifers to coastal waters.

Current-voltage characteristics in organic field-effect transistors. Effect of interface dipoles

NASA Astrophysics Data System (ADS)

Sworakowski, Juliusz

2015-07-01

The role of polar molecules present at dielectric/semiconductor interfaces of organic field-effect transistors (OFETs) has been assessed employing the electrostatic model put forward in a recently published paper (Sworakowski et al., 2014). The interface dipoles create dipolar traps in the surface region of the semiconductor, their depths decreasing with the distance from the interface. This feature results in appearance of mobility gradients in the direction perpendicular to the dielectric/semiconductor interface, manifesting themselves in modification of the shapes of current-voltage characteristics. The effect may account for differences in carrier mobilities determined from the same experimental data using methods scanning different ranges of channel thicknesses (e.g., transconductances vs. transfer characteristics), differences between turn-on voltages and threshold voltages, and gate voltage dependence of mobility.

Stable organic thin-film transistors

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

Jia, Xiaojia; Fuentes-Hernandez, Canek; Wang, Cheng-Yin

Organic thin-film transistors (OTFTs) can be fabricated at moderate temperatures and through cost-effective solution-based processes on a wide range of low-cost flexible and deformable substrates. Although the charge mobility of state-of-the-art OTFTs is superior to that of amorphous silicon and approaches that of amorphous oxide thin-film transistors (TFTs), their operational stability generally remains inferior and a point of concern for their commercial deployment. We report on an exhaustive characterization of OTFTs with an ultrathin bilayer gate dielectric comprising the amorphous fluoropolymer CYTOP and an Al2O3:HfO2 nanolaminate. Threshold voltage shifts measured at room temperatureovertimeperiods upto5.9×105 s do not vary monotonically andmore » remain below 0.2 V in microcrystalline OTFTs (mc-OTFTs) with field-effect carrier mobility values up to 1.6 cm2 V-1 s-1. Modeling of these shifts as a function of time with a double stretched-exponential (DSE) function suggests that two compensating aging mechanisms are at play and responsible for this high stability. The measured threshold voltage shifts at temperatures up to 75°C represent at least a one-order-of-magnitude improvement in the operational stability over previous reports, bringing OTFT technologies to a performance level comparable to that reported in the scientific literature for other commercial TFTs technologies.« less

Stable organic thin-film transistors

DOE PAGES

Jia, Xiaojia; Fuentes-Hernandez, Canek; Wang, Cheng-Yin; ...

2018-01-12

Organic thin-film transistors (OTFTs) can be fabricated at moderate temperatures and through cost-effective solution-based processes on a wide range of low-cost flexible and deformable substrates. Although the charge mobility of state-of-the-art OTFTs is superior to that of amorphous silicon and approaches that of amorphous oxide thin-film transistors (TFTs), their operational stability generally remains inferior and a point of concern for their commercial deployment. We report on an exhaustive characterization of OTFTs with an ultrathin bilayer gate dielectric comprising the amorphous fluoropolymer CYTOP and an Al2O3:HfO2 nanolaminate. Threshold voltage shifts measured at room temperatureovertimeperiods upto5.9×105 s do not vary monotonically andmore » remain below 0.2 V in microcrystalline OTFTs (mc-OTFTs) with field-effect carrier mobility values up to 1.6 cm2 V-1 s-1. Modeling of these shifts as a function of time with a double stretched-exponential (DSE) function suggests that two compensating aging mechanisms are at play and responsible for this high stability. The measured threshold voltage shifts at temperatures up to 75°C represent at least a one-order-of-magnitude improvement in the operational stability over previous reports, bringing OTFT technologies to a performance level comparable to that reported in the scientific literature for other commercial TFTs technologies.« less

Gas-Phase Dopant-Induced Conformational Changes Monitored with Transversal Modulation Ion Mobility Spectrometry.

PubMed

Meyer, Nicole Andrea; Root, Katharina; Zenobi, Renato; Vidal-de-Miguel, Guillermo

2016-02-16

The potential of a Transversal Modulation Ion Mobility Spectrometry (TMIMS) instrument for protein analysis applications has been evaluated. The Collision Cross Section (CCS) of cytochrome c measured with the TMIMS is in agreement with values reported in the literature. Additionally, it enables tandem IMS-IMS prefiltration in dry gas and in vapor doped gas. The chemical specificity of the different dopants enables interesting studies on the structure of proteins as CCS changed strongly depending on the specific dopant. Hexane produced an unexpectedly high CCS shift, which can be utilized to evaluate the exposure of hydrophobic parts of the protein. Alcohols produced higher shifts with a dual behavior: an increase in CCS due to vapor uptake at specific absorption sites, followed by a linear shift typical for unspecific and unstable vapor uptake. The molten globule +8 shows a very specific transition. Initially, its CCS follows the trend of the compact folded states, and then it rapidly increases to the levels of the unfolded states. This strong variation suggests that the +8 charge state undergoes a dopant-induced conformational change. Interestingly, more sterically demanding alcohols seem to unfold the protein more effectively also in the gas phase. This study shows the capabilities of the TMIMS device for protein analysis and how tandem IMS-IMS with dopants could provide better understanding of the conformational changes of proteins.

Stable organic thin-film transistors

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

Jia, Xiaojia; Fuentes-Hernandez, Canek; Wang, Cheng-Yin

2018-01-01

Organic thin-film transistors (OTFTs) can be fabricated at moderate temperatures and through cost-effective solution-based processes on a wide range of low-cost flexible and deformable substrates. Although the charge mobility of state-of-the-art OTFTs is superior to that of amorphous silicon and approaches that of amorphous oxide thin-film transistors (TFTs), their operational stability generally remains inferior and a point of concern for their commercial deployment. We report on an exhaustive characterization of OTFTs with an ultrathin bilayer gate dielectric comprising the amorphous fluoropolymer CYTOP and an Al2O3:HfO2 nanolaminate. Threshold voltage shifts measured at room temperatureovertimeperiods upto5.9×105 s do not vary monotonically andmore » remain below 0.2 V in microcrystalline OTFTs (mc-OTFTs) with field-effect carrier mobility values up to 1.6 cm2 V−1 s−1. Modeling of these shifts as a function of time with a double stretched-exponential (DSE) function suggests that two compensating aging mechanisms are at play and responsible for this high stability. The measured threshold voltage shifts at temperatures up to 75°C represent at least a one-order-of-magnitude improvement in the operational stability over previous reports, bringing OTFT technologies to a performance level comparable to that reported in the scientific literature for other commercial TFTs technologies.« less

A comparison between coherent and noncoherent mobile systems in large Doppler shift, delay spread, and C/I environment

NASA Technical Reports Server (NTRS)

Feher, Kamilo

1993-01-01

The performance and implementation complexity of coherent and of noncoherent QPSK and GMSK modulation/demodulation techniques in a complex mobile satellite systems environment, including large Doppler shift, delay spread, and low C/I, are compared. We demonstrate that for large f(sub d)T(sub b) products, where f(sub d) is the Doppler shift and T(sub b) is the bit duration, noncoherent (discriminator detector or differential demodulation) systems have a lower BER floor than their coherent counterparts. For significant delay spreads, e.g., tau(sub rms) greater than 0.4 T(sub b), and low C/I, coherent systems outperform noncoherent systems. However, the synchronization time of coherent systems is longer than that of noncoherent systems. Spectral efficiency, overall capacity, and related hardware complexity issues of these systems are also analyzed. We demonstrate that coherent systems have a simpler overall architecture (IF filter implementation-cost versus carrier recovery) and are more robust in an RF frequency drift environment. Additionally, the prediction tools, computer simulations, and analysis of coherent systems is simpler. The threshold or capture effect in low C/I interference environment is critical for noncoherent discriminator based systems. We conclude with a comparison of hardware architectures of coherent and of noncoherent systems, including recent trends in commercial VLSI technology and direct baseband to RF transmit, RF to baseband (0-IF) receiver implementation strategies.

A comparison between coherent and noncoherent mobile systems in large Doppler shift, delay spread, and C/I environment

NASA Astrophysics Data System (ADS)

Feher, Kamilo

The performance and implementation complexity of coherent and of noncoherent QPSK and GMSK modulation/demodulation techniques in a complex mobile satellite systems environment, including large Doppler shift, delay spread, and low C/I, are compared. We demonstrate that for large f(sub d)T(sub b) products, where f(sub d) is the Doppler shift and T(sub b) is the bit duration, noncoherent (discriminator detector or differential demodulation) systems have a lower BER floor than their coherent counterparts. For significant delay spreads, e.g., tau(sub rms) greater than 0.4 T(sub b), and low C/I, coherent systems outperform noncoherent systems. However, the synchronization time of coherent systems is longer than that of noncoherent systems. Spectral efficiency, overall capacity, and related hardware complexity issues of these systems are also analyzed. We demonstrate that coherent systems have a simpler overall architecture (IF filter implementation-cost versus carrier recovery) and are more robust in an RF frequency drift environment. Additionally, the prediction tools, computer simulations, and analysis of coherent systems is simpler. The threshold or capture effect in low C/I interference environment is critical for noncoherent discriminator based systems. We conclude with a comparison of hardware architectures of coherent and of noncoherent systems, including recent trends in commercial VLSI technology and direct baseband to RF transmit, RF to baseband (0-IF) receiver implementation strategies.

Stable organic thin-film transistors

PubMed Central

Jia, Xiaojia; Fuentes-Hernandez, Canek; Wang, Cheng-Yin; Park, Youngrak; Kippelen, Bernard

2018-01-01

Organic thin-film transistors (OTFTs) can be fabricated at moderate temperatures and through cost-effective solution-based processes on a wide range of low-cost flexible and deformable substrates. Although the charge mobility of state-of-the-art OTFTs is superior to that of amorphous silicon and approaches that of amorphous oxide thin-film transistors (TFTs), their operational stability generally remains inferior and a point of concern for their commercial deployment. We report on an exhaustive characterization of OTFTs with an ultrathin bilayer gate dielectric comprising the amorphous fluoropolymer CYTOP and an Al2O3:HfO2 nanolaminate. Threshold voltage shifts measured at room temperature over time periods up to 5.9 × 105 s do not vary monotonically and remain below 0.2 V in microcrystalline OTFTs (μc-OTFTs) with field-effect carrier mobility values up to 1.6 cm2 V−1 s−1. Modeling of these shifts as a function of time with a double stretched-exponential (DSE) function suggests that two compensating aging mechanisms are at play and responsible for this high stability. The measured threshold voltage shifts at temperatures up to 75°C represent at least a one-order-of-magnitude improvement in the operational stability over previous reports, bringing OTFT technologies to a performance level comparable to that reported in the scientific literature for other commercial TFTs technologies. PMID:29340301

Saccade-synchronized rapid attention shifts in macaque visual cortical area MT.

PubMed

Yao, Tao; Treue, Stefan; Krishna, B Suresh

2018-03-06

While making saccadic eye-movements to scan a visual scene, humans and monkeys are able to keep track of relevant visual stimuli by maintaining spatial attention on them. This ability requires a shift of attentional modulation from the neuronal population representing the relevant stimulus pre-saccadically to the one representing it post-saccadically. For optimal performance, this trans-saccadic attention shift should be rapid and saccade-synchronized. Whether this is so is not known. We trained two rhesus monkeys to make saccades while maintaining covert attention at a fixed spatial location. We show that the trans-saccadic attention shift in cortical visual medial temporal (MT) area is well synchronized to saccades. Attentional modulation crosses over from the pre-saccadic to the post-saccadic neuronal representation by about 50 ms after a saccade. Taking response latency into account, the trans-saccadic attention shift is well timed to maintain spatial attention on relevant stimuli, so that they can be optimally tracked and processed across saccades.

Modeling neck mobility in fossil turtles.

PubMed

Werneburg, Ingmar; Hinz, Juliane K; Gumpenberger, Michaela; Volpato, Virginie; Natchev, Nikolay; Joyce, Walter G

2015-05-01

Turtles have the unparalleled ability to retract their heads and necks within their shell but little is known about the evolution of this trait. Extensive analysis of neck mobility in turtles using radiographs, CT scans, and morphometry reveals that basal turtles possessed less mobility in the neck relative to their extant relatives, although the anatomical prerequisites for modern mobility were already established. Many extant turtles are able to achieve hypermobility by dislocating the central articulations, which raises cautions about reconstructing the mobility of fossil vertebrates. A 3D-model of the Late Triassic turtle Proganochelys quenstedti reveals that this early stem turtle was able to retract its head by tucking it sideways below the shell. The simple ventrolateral bend seen in this stem turtle, however, contrasts with the complex double-bend of extant turtles. The initial evolution of neck retraction therefore occurred in a near-synchrony with the origin of the turtle shell as a place to hide the unprotected neck. In this early, simplified retraction mode, the conical osteoderms on the neck provided further protection. © 2014 Wiley Periodicals, Inc.

Evaluation of mobile phone addiction level and sleep quality in university students.

PubMed

Sahin, Sevil; Ozdemir, Kevser; Unsal, Alaattin; Temiz, Nazen

2013-07-01

To determine the mobile phone addiction level in university students, to examine several associated factors and to evaluate the relation between the addiction level and sleep quality. The study is a cross-sectional research conducted on the students of the Sakarya University between 01 November 2012 and 01 February 2013. The study group included 576 students. The Problematic Mobile Phone Use Scale was used for evaluating the mobile phone addiction level and the Pittsburgh Sleep Quality Index for assessing the sleep quality. Mann-Whitney U test, Kruskal-Wallis test and Spearman's Correlation Analysis were used for analyzing the data. The study group consisted of 296 (51.4%) females and 208 (48.6%) males. The mean age was 20.83 ± 1.90 years (min:17, max:28). The addiction level was determined to be higher in the second-year students, those with poor family income, those with type A personality, those whose age for first mobile phone is 13 and below and those whose duration of daily mobile phone use is above 5 hours (p < 0.05 for each). The sleep quality worsens with increasing mobile phone addiction level (p < 0.05). The sleep quality worsens with increasing addiction level. It was concluded that referring the students with suspected addiction to advanced healthcare facilities, performing occasional scans for early diagnosis and informing the students about controlled mobile phone use would be useful.

Analysis of accuracy airborne, terrestrial and mobile laser scanning data as an introduction to their integration). (Polish Title: Analiza dokładności przestrzennej danych z lotniczego, naziemnego i mobilnego skaningu laserowego jako wstęp do ich integracji)

NASA Astrophysics Data System (ADS)

Warchoł, A.

2013-12-01

The following article presents an analysis of accuracy three point clouds (airborne, terrestrial and mobile) obtained for the same area. The study was conducted separately for the coordinates (X, Y) - examining the location of buildings vertex and separately for the coordinate (Z) - comparing models built on each of the clouds. As a baseline measurement for both analyzes (X, Y and Z), the total station measurement was taken.

Perioperative Brain Shift and Deep Brain Stimulating Electrode Deformation Analysis: Implications for rigid and non-rigid devices

PubMed Central

Sillay, Karl A.; Kumbier, L. M.; Ross, C.; Brady, M.; Alexander, A.; Gupta, A.; Adluru, N.; Miranpuri, G. S.; Williams, J. C.

2016-01-01

Deep brain stimulation (DBS) efficacy is related to optimal electrode placement. Several authors have quantified brain shift related to surgical targeting; yet, few reports document and discuss the effects of brain shift after insertion. Objective: To quantify brain shift and electrode displacement after device insertion. Twelve patients were retrospectively reviewed, and one post-operative MRI and one time-delayed CT were obtained for each patient and their implanted electrodes modeled in 3D. Two competing methods were employed to measure the electrode tip location and deviation from the prototypical linear implant after the resolution of acute surgical changes, such as brain shift and pneumocephalus. In the interim between surgery and a pneumocephalus free postoperative scan, electrode deviation was documented in all patients and all electrodes. Significant shift of the electrode tip was identified in rostral, anterior, and medial directions (p < 0.05). Shift was greatest in the rostral direction, measuring an average of 1.41 mm. Brain shift and subsequent electrode displacement occurs in patients after DBS surgery with the reversal of intraoperative brain shift. Rostral displacement is on the order of the height of one DBS contact. Further investigation into the time course of intraoperative brain shift and its potential effects on procedures performed with rigid and non-rigid devices in supine and semi-sitting surgical positions is needed. PMID:23010803

Role of aerosil dispersion on the activated kinetics of the LC1-xSilx system.

PubMed

Sharma, Dipti; MacDonald, John C; Iannacchione, Germano S

2006-12-28

This study explores the role of aerosil dispersion on activated phase transitions of bulk octylcyanobiphenyl (8CB) liquid crystals by performing heating rate-dependent experiments. Differential scanning calorimetry (DSC) was used at various heating ramp rates in order to probe the activated phase dynamics of the system. The system, LC1-xSilx, was prepared by mixing aerosil nanoparticles (7 nm in diameter) in the bulk 8CB by the solvent dispersion method (SDM). LC represents bulk 8CB, and Sil represents aerosil nanoparticles with concentration x in percent. The concentration of the aerosil nanoparticles (x) varied from 0 to 0.2 g/cm3 in the bulk 8CB. Well-defined, endothermic peaks were found on a heating scan at melting and at the smectic-A to nematic (SmA-N) and nematic to isotropic (N-I) transitions. These peaks show a temperature shift and a change in their shapes and sizes in the presence of aerosil nanoparticles. In addition, an exothermic peak also appeared before the melting peak during the heating scan in the presence of aerosil nanoparticles. All transitions shifted significantly with different heating ramp rates, following an Arrhenius behavior, showing activated kinetics. The presence of aerosil nanoparticles caused a significant increase in the enthalpy and a decrease in the activation energy compared to the results found in bulk 8CB. This behavior can be explained by aerosil dispersion in the LC1-xSilx, inducing a disorder in the bulk 8CB. Infrared (IR) spectroscopy shows a shift to higher frequency for the broad peak at 1082 cm-1, corresponding to an Si-O bond as the density of the aerosil increases, and can be explained in terms of surface and molecular interactions between aerosil nanoparticles and 8CB liquid crystal molecules.

Essentials of LIDAR multiangle data processing methodology for smoke polluted atmospheres

Treesearch

V. A. Kovalev; A. Petkov; C. Wold; S. Urbanski; W. M. Hao

2009-01-01

Mobile scanning lidar is the most appropriate tool for monitoring wildfire smoke-plume dynamics and optical properties. Lidar is the only remote sensing instrument capable of obtaining detailed three-dimensional range-resolved information for smoke distributions and optical properties over ranges of 10+ km at different wavelengths simultaneously.

OZONE-ISOPRENE REACTION: RE-EXAMINATION OF THE FORMATION OF SECONDARY ORGANIC AEROSOL

EPA Science Inventory

The reaction of ozone and isoprene has been studied to examine physical and chemical characteristics of the secondary organic aerosol formed. Using a scanning mobility particle sizer, the volume distribution of the aerosol was found in the range 0.05 - 0.2 µm. The aerosol yield w...

Segway Robotic Mobility Platform

DTIC Science & Technology

2004-10-01

involved changes to firmware and creation of an electrical interface to the RMP. The existing HT design offered the possibility of creating a reliable...mounted on its side and swept back and forth by an Amtec pan-and-tilt unit to acquire 3-D scans of the environment. The RMP also carries an

Unilateral pleural effusion in an animal model: evaluation of lung function with EBCT

NASA Astrophysics Data System (ADS)

Recheis, Wolfgang A.; Pallwein, Leo; Soegner, Peter; Faschingbauer, Ralph; Schmidbauer, Georg; Kleinsasser, Axel; Loeckinger, Alexander; Hoermann, Christoph; zur Nedden, Dieter

2003-05-01

The purpsoe was to evaluate the influence of a right-sided pleural effusion on the lung aeration dynamics in the respiratory cycle during pressure controlled ventilation. Pleural effusion was simulated by infusion of 3% gelatin into the pleural cavity in steps of 300ml totaling 1200ml in four anesthetized pigs. After each step, volume scans and respirator gated 50ms scans at a constant table position (carina niveau) were taken. The dynamic changes of the previously defined air-tissue ratios (in steps of 100HU) were evaluated in three separate regions of left and right lung: a ventral, an intermediate and a dorsal area. The affected side revealed dramatic alveolar collapse. There was a shift of the lung density to higher air-tissue ratios (+200HU) but showing the same air-tissue ratio dynamics. A slight lateral shift of 32mm (+/-14mm) the mediastinum was measured. The unaffected side showed no increase in the air-tissue ratios caused by hyperinflation but an increase of density due to mediastinal shift. Air-tissue ratio dynamics remained unchanged on the unaffected side compared to baseline measurements. We visualized the ventilation mismatch caused by pleural effusion. The contra-lateral lung is not affected by unilateral pleural effusion. Pressure controlled ventilation prevents hyper-inflation of non-dependent lung areas.

Alleviating artifacts in 1H MRI thermometry by single scan spatiotemporal encoding.

PubMed

Schmidt, Rita; Frydman, Lucio

2013-10-01

Recent years have seen an increased interest in combining MRI thermometry with devices capable of destroying malignancies by heat ablation. Expected from the MR protocols are accurate and fast thermal characterizations, providing real time feedback on restricted tissue volumes and/or rapidly moving organs like liver. This article explores the potential advantages of relying on spatiotemporally encoded (SPEN) sequences for retrieving real-time thermometric images based on the water's proton resonance frequency (PRF) shifts. Hybrid spatiotemporal/k-space encoding single-scan MRI experiments were implemented on animal and human scanners, and their abilities to deliver single- and multi-slice real-time thermometric measurements based on PRF-derived phase maps in phantoms and in vivo, were compared against echo planar imaging (EPI) and gradient-echo counterparts. Under comparable acquisition conditions, SPEN exhibited advantages vis-à-vis EPI in terms of dealing with inhomogeneous magnetic field distortions, with shifts arising due to changes in the central frequency offsets, with PRF distributions, and for zooming into restricted fields-of-view without special pulse sequence provisions. This work confirms the ability of SPEN sequences, particularly when implemented under fully-refocused conditions, to exploit their built-in robustness to shift- and field-derived inhomogeneities for monitoring thermal changes in real-time under in vitro and in vivo conditions.

Self-correcting electronically scanned pressure sensor

NASA Technical Reports Server (NTRS)

Gross, C. (Inventor)

1983-01-01

A multiple channel high data rate pressure sensing device is disclosed for use in wind tunnels, spacecraft, airborne, process control, automotive, etc., pressure measurements. Data rates in excess of 100,000 measurements per second are offered with inaccuracies from temperature shifts less than 0.25% (nominal) of full scale over a temperature span of 55 C. The device consists of thirty-two solid state sensors, signal multiplexing electronics to electronically address each sensor, and digital electronic circuitry to automatically correct the inherent thermal shift errors of the pressure sensors and their associated electronics.

On-chip beam positioning sensor via frequency locked cascaded ring resonators

NASA Astrophysics Data System (ADS)

Naiman, Alex; Stern, Liron; Levy, Uriel

2018-05-01

We demonstrate an approach for on-chip beam positioning with a position accuracy of up to 100 nm. This approach is based on tracking the resonance of two adjacent microring resonators that are implemented on a silicon on insulator chip. We demonstrate the functionality of our approach by illuminating the chip through a Near Field Scanning Optical Microscope tip and monitoring the shift of the microring resonances due to the thermo-optic effect. We also discuss the contribution of different effects such as free carrier absorption and dispersion to the resonance shift.

Social, Spatial and Legislative Strategy to Shift Urban Mobility Patterns

NASA Astrophysics Data System (ADS)

Branea, Ana-Maria; Gaman, Marius; Badescu, Stefana

2017-10-01

A city’s predominant transportation mode is crucial in determining its type of urban tissue. A denser and more compact urban development is generated through pedestrian, bicycle and public transit while car based developments tend to be dispersed, characterized by unsustainable low densities. However, a clear implementation strategy eludes many urban planning practitioners and public administrations, thus highlighting the need for further research. Following an international trend, Timisoara’s mobility strategy over the past two decades, has been to accommodate an ever-increasing number of vehicles on its underdeveloped infrastructure at the expense of green areas, pedestrian lanes and even travel-turned-parking lanes. Despite the latest, slight, shift towards inner city urban development only 11% of the proposed Urban Mobility Strategy’s policies are not centred on cars. Through a 15 criteria analysis of the main means of transportation, pedestrian, bicycle, public transit and car, the authors determined the most sustainable and efficient mode based on the distance - duration relationship as being bicycles, for a city of Timisoara’s size and characteristics. Yet, the city’s infrastructure scored poorly on safety and comfort due to its incoherence and numerous dysfunctionalities. To better illustrate and understand Timisoara’s current state and proposed mobility strategy, the authors undertook a comparative analysis of Timisoara’s and Utrecht’s bike lane infrastructure. Similarities in size and number of inhabitants were only secondary selection criteria compared to Utrecht’s aspiring to model status. The aim of this study is to present the long term, multi-tier implementation strategy proposed to reorient Timisoara’s urban development towards a more compact, sustainable typology. Comprising social-educational, spatial and legislative objectives the strategy aspires to modify local behaviour towards and perception of alternative modes of transportation by influencing human behaviour at a strategic and tactical level.

Dynamics-based selective 2D 1H/1H chemical shift correlation spectroscopy under ultrafast MAS conditions

NASA Astrophysics Data System (ADS)

Zhang, Rongchun; Ramamoorthy, Ayyalusamy

2015-05-01

Dynamics plays important roles in determining the physical, chemical, and functional properties of a variety of chemical and biological materials. However, a material (such as a polymer) generally has mobile and rigid regions in order to have high strength and toughness at the same time. Therefore, it is difficult to measure the role of mobile phase without being affected by the rigid components. Herein, we propose a highly sensitive solid-state NMR approach that utilizes a dipolar-coupling based filter (composed of 12 equally spaced 90° RF pulses) to selectively measure the correlation of 1H chemical shifts from the mobile regions of a material. It is interesting to find that the rotor-synchronized dipolar filter strength decreases with increasing inter-pulse delay between the 90° pulses, whereas the dipolar filter strength increases with increasing inter-pulse delay under static conditions. In this study, we also demonstrate the unique advantages of proton-detection under ultrafast magic-angle-spinning conditions to enhance the spectral resolution and sensitivity for studies on small molecules as well as multi-phase polymers. Our results further demonstrate the use of finite-pulse radio-frequency driven recoupling pulse sequence to efficiently recouple weak proton-proton dipolar couplings in the dynamic regions of a molecule and to facilitate the fast acquisition of 1H/1H correlation spectrum compared to the traditional 2D NOESY (Nuclear Overhauser effect spectroscopy) experiment. We believe that the proposed approach is beneficial to study mobile components in multi-phase systems, such as block copolymers, polymer blends, nanocomposites, heterogeneous amyloid mixture of oligomers and fibers, and other materials.

Analysis of healthy sitting behavior: interface pressure distribution and subcutaneous tissue oxygenation.

PubMed

Reenalda, Jasper; Van Geffen, Paul; Nederhand, Marc; Jannink, Michiel; IJzerman, Maarten; Rietman, Hans

2009-01-01

Pressure ulcers are a large problem in individuals who use a wheelchair for their mobility and have limited trunk stability and motor function. Because no relation between interface pressure and pressure ulcer development has been established and no clinical threshold for pressure ulcer development can be given, looking at the sitting behavior of nondisabled individuals is important. Nondisabled individuals do not develop pressure ulcers because they continuously shift posture. We analyzed the sitting behavior of 25 nondisabled male subjects by using a combination of interface pressure measurement and subcutaneous tissue oxygenation measurement by means of the Oxygen to See. These subjects shifted posture on average 7.8 +/- 5.2 times an hour. These posture shifts were merely a combination of posture shifts in the frontal and sagittal plane. Subcutaneous oxygen saturation increased on average 2.2% with each posture adjustment, indicating a positive effect of posture shifts on tissue viability. The results of this study can be used as a reference for seating interventions aimed at preventing pressure ulcers. Changing the sitting load at least every 8 minutes is recommended for wheelchair users.

Real-Time Fatigue Reduction in Emergency Care Clinicians: The SleepTrackTXT Randomized Trial

PubMed Central

Patterson, P. Daniel; Buysse, Daniel J.; Weaver, Matthew D.; Doman, Jack M.; Moore, Charity G.; Suffoletto, Brian P.; McManigle, Kyle L.; Callaway, Clifton W.; Yealy, Donald M.

2015-01-01

Background We assessed performance characteristics and impact of a mobile phone text-message intervention for reducing intra-shift fatigue among emergency clinician shift workers. Methods We used a randomized controlled trial of 100 participants. All participants received text-message assessments at the start, every 4-hours during, and at end of scheduled shifts over a 90-day period. Text-message queries measured self-rated sleepiness, fatigue, and difficulty with concentration. Additional text-messages were sent to intervention participants to promote alertness. A performance measure of interest was compliance with answering text-messages. Results Ninety-nine participants documented 2,621 shifts and responded to 36,073 of 40,947 text-messages (88% compliance rate). Intervention participants reported lower mean fatigue and sleepiness at 4 hours, 8 hours, and at the end of 12-hour shifts compared to controls (p<0.05). Intervention participants reported better sleep quality at 90-days compared to baseline (p=0.01). Conclusions We showed feasibility and short-term efficacy of a text-message based assessment and intervention tool. PMID:26305869

Executive function processes predict mobility outcomes in older adults.

PubMed

Gothe, Neha P; Fanning, Jason; Awick, Elizabeth; Chung, David; Wójcicki, Thomas R; Olson, Erin A; Mullen, Sean P; Voss, Michelle; Erickson, Kirk I; Kramer, Arthur F; McAuley, Edward

2014-02-01

To examine the relationship between performance on executive function measures and subsequent mobility outcomes in community-dwelling older adults. Randomized controlled clinical trial. Champaign-Urbana, Illinois. Community-dwelling older adults (N = 179; mean age 66.4). A 12-month exercise trial with two arms: an aerobic exercise group and a stretching and strengthening group. Established cognitive tests of executive function (flanker task, task switching, and a dual-task paradigm) and the Wisconsin card sort test. Mobility was assessed using the timed 8-foot up and go test and times to climb up and down a flight of stairs. Participants completed the cognitive tests at baseline and the mobility measures at baseline and after 12 months of the intervention. Multiple regression analyses were conducted to determine whether baseline executive function predicted postintervention functional performance after controlling for age, sex, education, cardiorespiratory fitness, and baseline mobility levels. Selective baseline executive function measurements, particularly performance on the flanker task (β = 0.15-0.17) and the Wisconsin card sort test (β = 0.11-0.16) consistently predicted mobility outcomes at 12 months. The estimates were in the expected direction, such that better baseline performance on the executive function measures predicted better performance on the timed mobility tests independent of intervention. Executive functions of inhibitory control, mental set shifting, and attentional flexibility were predictive of functional mobility. Given the literature associating mobility limitations with disability, morbidity, and mortality, these results are important for understanding the antecedents to poor mobility function that well-designed interventions to improve cognitive performance can attenuate. © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.

Mapping of the local environmental changes in proteins by cysteine scanning

PubMed Central

Yamazaki, Yoichi; Nagata, Tomoko; Terakita, Akihisa; Kandori, Hideki; Shichida, Yoshinori; Imamoto, Yasushi

2014-01-01

Protein conformational changes, which regulate the activity of proteins, are induced by the alternation of intramolecular interactions. Therefore, the detection of the local environmental changes around the key amino acid residues is essential to understand the activation mechanisms of functional proteins. Here we developed the methods to scan the local environmental changes using the vibrational band of cysteine S-H group. We validated the sensitivity of this method using bathorhodopsin, a photoproduct of rhodopsin trapped at liquid nitrogen temperature, which undergoes little conformational changes from the dark state as shown by the X-ray crystallography. The cysteine residues were individually introduced into 15 positions of Helix III, which contains several key amino acid residues for the light-induced conformational changes of rhodopsin. The shifts of S-H stretching modes of these cysteine residues and native cysteine residues upon the formation of bathorhodopsin were measured by Fourier transform infrared spectroscopy. While most of cysteine residues demonstrated no shift of S-H stretching mode, cysteine residues introduced at positions 117, 118, and 122, which are in the vicinity of the chromophore, demonstrated the significant changes. The current results are consistent with the crystal structure of bathorhodopsin, implying that the cysteine scanning is sensitive enough to detect the tiny conformational changes. PMID:27493492

High-speed line-scan camera with digital time delay integration

NASA Astrophysics Data System (ADS)

Bodenstorfer, Ernst; Fürtler, Johannes; Brodersen, Jörg; Mayer, Konrad J.; Eckel, Christian; Gravogl, Klaus; Nachtnebel, Herbert

2007-02-01

Dealing with high-speed image acquisition and processing systems, the speed of operation is often limited by the amount of available light, due to short exposure times. Therefore, high-speed applications often use line-scan cameras, based on charge-coupled device (CCD) sensors with time delayed integration (TDI). Synchronous shift and accumulation of photoelectric charges on the CCD chip - according to the objects' movement - result in a longer effective exposure time without introducing additional motion blur. This paper presents a high-speed color line-scan camera based on a commercial complementary metal oxide semiconductor (CMOS) area image sensor with a Bayer filter matrix and a field programmable gate array (FPGA). The camera implements a digital equivalent to the TDI effect exploited with CCD cameras. The proposed design benefits from the high frame rates of CMOS sensors and from the possibility of arbitrarily addressing the rows of the sensor's pixel array. For the digital TDI just a small number of rows are read out from the area sensor which are then shifted and accumulated according to the movement of the inspected objects. This paper gives a detailed description of the digital TDI algorithm implemented on the FPGA. Relevant aspects for the practical application are discussed and key features of the camera are listed.

Enhanced resolution imaging of ultrathin ZnO layers on Ag(111) by multiple hydrogen molecules in a scanning tunneling microscope junction

NASA Astrophysics Data System (ADS)

Liu, Shuyi; Shiotari, Akitoshi; Baugh, Delroy; Wolf, Martin; Kumagai, Takashi

2018-05-01

Molecular hydrogen in a scanning tunneling microscope (STM) junction has been found to enhance the lateral spatial resolution of the STM imaging, referred to as scanning tunneling hydrogen microscopy (STHM). Here we report atomic resolution imaging of 2- and 3-monolayer (ML) thick ZnO layers epitaxially grown on Ag(111) using STHM. The enhanced resolution can be obtained at a relatively large tip to surface distance and resolves a more defective structure exhibiting dislocation defects for 3-ML-thick ZnO than for 2 ML. In order to elucidate the enhanced imaging mechanism, the electric and mechanical properties of the hydrogen molecular junction (HMJ) are investigated by a combination of STM and atomic force microscopy. It is found that the HMJ shows multiple kinklike features in the tip to surface distance dependence of the conductance and frequency shift curves, which are absent in a hydrogen-free junction. Based on a simple modeling, we propose that the junction contains several hydrogen molecules and sequential squeezing of the molecules out of the junction results in the kinklike features in the conductance and frequency shift curves. The model also qualitatively reproduces the enhanced resolution image of the ZnO films.

An absolute method for determination of misalignment of an immersion ultrasonic transducer.

PubMed

Narayanan, M M; Singh, Narender; Kumar, Anish; Babu Rao, C; Jayakumar, T

2014-12-01

An absolute methodology has been developed for quantification of misalignment of an ultrasonic transducer using a corner-cube retroreflector. The amplitude based and the time of flight (TOF) based C-scans of the reflector are obtained for various misalignments of the transducer. At zero degree orientation of the transducer, the vertical positions of the maximum amplitude and the minimum TOF in the C-scan coincide. At any other orientation of the transducer with the horizontal plane, there is a vertical shift in the position of the maximum amplitude with respect to the minimum TOF. The position of the minimum (TOF) remains the same irrespective of the orientation of the transducer and hence is used as a reference for any misalignment of the transducer. With the measurement of the vertical shift and the horizontal distance between the transducer and the vertex of the reflector, the misalignment of the transducer is quantified. Based on the methodology developed in the present study, retroreflectors are placed in the Indian 500MWe Prototype Fast Breeder Reactor for assessment of the orientation of the ultrasonic transducer prior to the under-sodium ultrasonic scanning for detection of any protrusion of the subassemblies. Copyright © 2014 Elsevier B.V. All rights reserved.

Accurate Ultrasonic Measurement of Surface Profile Using Phase Shift of Echo and Inverse Filtering

NASA Astrophysics Data System (ADS)

Arihara, Chihiro; Hasegawa, Hideyuki; Kanai, Hiroshi

2006-05-01

Atherosclerosis is the main cause of circulatory diseases such as myocardial infarction and cerebral infarction, and it is very important to diagnose atherosclerosis in its early stage. In the early stage of atherosclerosis, the luminal surface of an arterial wall becomes rough because of the injury of the endothelium [R. Ross: New Engl. J. Med. 340 (2004) 115]. Conventional ultrasonic diagnostic equipments cannot detect such roughness on the order of micrometer because of their low resolution of approximately 0.1 mm. In this study, for the accurate detection of surface roughness, an ultrasonic beam was scanned in the direction that is parallel to the surface of an object. When there is a gap on the surface, the phase of the echo from the surface changes because the distance between the probe and the surface changes during the scanning. Therefore, surface roughness can be assessed by estimating the phase shift of echoes obtained during the beam scanning. Furthermore, lateral resolution, which is deteriorated by a finite diameter of the ultrasound beam, was improved by an inverse filter. By using the proposed method, the surface profile of a phantom, which had surface roughness on the micrometer order, was detected, and the estimated surface profiles became more precise by applying the inverse filter.

A Fourier Transform Spectrometer Based on an Electrothermal MEMS Mirror with Improved Linear Scan Range

PubMed Central

Wang, Wei; Chen, Jiapin; Zivkovic, Aleksandar. S.; Xie, Huikai

2016-01-01

A Fourier transform spectrometer (FTS) that incorporates a closed-loop controlled, electrothermally actuated microelectromechanical systems (MEMS) micromirror is proposed and experimentally verified. The scan range and the tilting angle of the mirror plate are the two critical parameters for MEMS-based FTS. In this work, the MEMS mirror with a footprint of 4.3 mm × 3.1 mm is based on a modified lateral-shift-free (LSF) bimorph actuator design with large piston and reduced tilting. Combined with a position-sensitive device (PSD) for tilt angle sensing, the feedback controlled MEMS mirror generates a 430 µm stable linear piston scan with the mirror plate tilting angle less than ±0.002°. The usable piston scan range is increased to 78% of the MEMS mirror’s full scan capability, and a spectral resolution of 0.55 nm at 531.9 nm wavelength, has been achieved. It is a significant improvement compared to the prior work. PMID:27690047

Adaptive multiphoton endomicroscopy through a dynamically deformed multicore optical fiber using proximal detection.

PubMed

Warren, Sean C; Kim, Youngchan; Stone, James M; Mitchell, Claire; Knight, Jonathan C; Neil, Mark A A; Paterson, Carl; French, Paul M W; Dunsby, Chris

2016-09-19

This paper demonstrates multiphoton excited fluorescence imaging through a polarisation maintaining multicore fiber (PM-MCF) while the fiber is dynamically deformed using all-proximal detection. Single-shot proximal measurement of the relative optical path lengths of all the cores of the PM-MCF in double pass is achieved using a Mach-Zehnder interferometer read out by a scientific CMOS camera operating at 416 Hz. A non-linear least squares fitting procedure is then employed to determine the deformation-induced lateral shift of the excitation spot at the distal tip of the PM-MCF. An experimental validation of this approach is presented that compares the proximally measured deformation-induced lateral shift in focal spot position to an independent distally measured ground truth. The proximal measurement of deformation-induced shift in focal spot position is applied to correct for deformation-induced shifts in focal spot position during raster-scanning multiphoton excited fluorescence imaging.

Operation of a wet near-field scanning optical microscope in stable zones by minimizing the resonance change of tuning forks.

PubMed

Park, Kyoung-Duck; Park, Doo Jae; Lee, Seung Gol; Choi, Geunchang; Kim, Dai-Sik; Byeon, Clare Chisu; Choi, Soo Bong; Jeong, Mun Seok

2014-02-21

A resonant shift and a decrease of resonance quality of a tuning fork attached to a conventional fiber optic probe in the vicinity of liquid is monitored systematically while varying the protrusion length and immersion depth of the probe. Stable zones where the resonance modification as a function of immersion depth is minimized are observed. A wet near-field scanning optical microscope (wet-NSOM) is operated for a sample within water by using such a stable zone.

Formation Flying and Deformable Instruments

NASA Astrophysics Data System (ADS)

Rio, Yvon

2009-05-01

Astronomers have always attempted to build very stable instruments. They fight all that can cause mechanical deformation or image motion. This has led to well established technologies (autoguide, active optics, thermal control, tip/tilt correction), as well as observing methods based on the use of controlled motion (scanning, micro scanning, shift and add, chopping and nodding). Formation flying disturbs this practice. It is neither possible to reduce the relative motion to very small amplitudes, nor to control it at will. Some impacts on Simbol-X instrument design, and operation are presented.

Race Moves: Following Global Manifestations of New Racisms in Intimate Space

ERIC Educational Resources Information Center

Mishra Tarc, Aparna

2013-01-01

This article makes tentative links between abstract global forces and the affective and material reworking of race in intimate spaces of culture and community. Using postcolonial and psychoanalytic resources the article follows enduring manifestations of race as racism surfaces and is mobilized through global shifts of people, ideas and capital.…

AIM for Digital Equity

ERIC Educational Resources Information Center

Bowser, Gayl; Zabala, Joy Smiley

2012-01-01

In a 2011 segment on CNN "Headline News," Doug Levin, CEO of the State Educational Technology Director's Association, asserted that the shift to Common Core State Standards, the prevalence of open content, and the rapid increase in the availability of mobile technology will soon make paper textbooks a thing of the past in U.S. schools. He predicts…

Leave islands as refugia for low-mobility species in managed forest mosaics

Treesearch

Stephanie J. Wessell-Kelly; Deanna H. Olson

2013-01-01

In recent years, forest management in the Pacifi c Northwest has shifted from one based largely on resource extraction to one based on ecosystem management principles. Forest management based on these principles involves simultaneously balancing and sustaining multiple forest resource values, including silvicultural, social, economic, and ecological objectives. Leave...

Macroscopic experimental and modeling evaluation of selenite and selenate adsorption mechanisms on gibbsite

USDA-ARS?s Scientific Manuscript database

Selenite Se(IV) and selenate Se(VI) adsorption behavior was investigated on gibbsite as a function of solution pH and solution ionic strength. Adsorption of both Se redox states decreased with increasing solution pH. Electrophoretic mobility measurements showed downward shifts in point of zero cha...

Political Reform and the Historical Trajectories of U.S. Social Movements in the Twentieth Century

ERIC Educational Resources Information Center

Amenta, Edwin; Caren, Neal; Stobaugh, James E.

2012-01-01

We propose a political reform theory, a political and historical institutionalist argument that holds that shifts in political structures, partisan regimes and policy greatly influence movements. We appraise this argument, along with resource mobilization, political opportunity and media alternatives, by analyzing 600,000 articles in the "New York…

Employee Turnover: Evidence from a Case Study.

ERIC Educational Resources Information Center

Borland, Jeff

1997-01-01

Patterns of employee turnover from a medium-sized law firm in Australia were examined in regard to theories of worker mobility (matching, sectoral shift, and incentive). Results support a role for matching effects, but personnel practices affect the timing of turnover. Matching and incentive-based theories do not explain the high rates of turnover…

Politics and School Education in Australia: A Case of Shifting Purposes

ERIC Educational Resources Information Center

Cranston, Neil; Kimber, Megan; Mulford, Bill; Reid, Alan; Keating, Jack

2010-01-01

Purpose: The paper aims to argue that there has been a privileging of the private (social mobility) and economic (social efficiency) purposes of schooling at the expense of the public (democratic equality) purposes of schooling. Design/methodology/approach: The paper employs a literature review, policy and document analysis. Findings: Since the…

Relational Rurals: Some Thoughts on Relating Things and Theory in Rural Studies

ERIC Educational Resources Information Center

Heley, Jesse; Jones, Laura

2012-01-01

This paper considers how shifts within the social sciences towards conceptualising spatiality in relational terms have unfolded in rural studies in particular ways over the past decade or so. A period in which networks, connections, flows and mobility have all established themselves as compelling conceptual frames for research, the rural has…

mHealth and big data will bring meaning and value to patient-reported outcomes.

PubMed

Weiler, Anne

2016-01-01

The intersection of widespread mobile adoption, cloud computing and healthcare will enable patient-reported outcomes to be used to personalize care, draw insights and shorten the cycle from research to clinical implementation. Today, patient-reported outcomes are largely collected as part of a regulatory shift to value-based or bundled care. When patients are able to record their experiences in real-time and combine them with passive data collection from sensors and mobile devices, this information can inform better care for each patient and contribute to the growing body of health data that can be used to draw insights for all patients. This paper explores the current limitations of patient reported outcomes and how mobile health and big data analysis unlocks their potential as a valuable tool to deliver care.

Adaptive data rate SSMA system for personal and mobile satellite communications

NASA Technical Reports Server (NTRS)

Ikegami, Tetsushi; Takahashi, Takashi; Arakaki, Yoshiya; Wakana, Hiromitsu

1995-01-01

An adaptive data rate SSMA (spread spectrum multiple access) system is proposed for mobile and personal multimedia satellite communications without the aid of system control earth stations. This system has a constant occupied bandwidth and has variable data rates and processing gains to mitigate communication link impairments such as fading, rain attenuation and interference as well as to handle variable data rate on demand. Proof of concept hardware for 6MHz bandwidth transponder is developed, that uses offset-QPSK (quadrature phase shift keying) and MSK (minimum shift keying) for direct sequence spread spectrum modulation and handle data rates of 4k to 64kbps. The RS422 data interface, low rate voice and H.261 video codecs are installed. The receiver is designed with coherent matched filter technique to achieve fast code acquisition, AFC (automatic frequency control) and coherent detection with minimum hardware losses in a single matched filter circuit. This receiver structure facilitates variable data rate on demand during a call. This paper shows the outline of the proposed system and the performance of the prototype equipment.

Revised motion estimation algorithm for PROPELLER MRI.

PubMed

Pipe, James G; Gibbs, Wende N; Li, Zhiqiang; Karis, John P; Schar, Michael; Zwart, Nicholas R

2014-08-01

To introduce a new algorithm for estimating data shifts (used for both rotation and translation estimates) for motion-corrected PROPELLER MRI. The method estimates shifts for all blades jointly, emphasizing blade-pair correlations that are both strong and more robust to noise. The heads of three volunteers were scanned using a PROPELLER acquisition while they exhibited various amounts of motion. All data were reconstructed twice, using motion estimates from the original and new algorithm. Two radiologists independently and blindly compared 216 image pairs from these scans, ranking the left image as substantially better or worse than, slightly better or worse than, or equivalent to the right image. In the aggregate of 432 scores, the new method was judged substantially better than the old method 11 times, and was never judged substantially worse. The new algorithm compared favorably with the old in its ability to estimate bulk motion in a limited study of volunteer motion. A larger study of patients is planned for future work. Copyright © 2013 Wiley Periodicals, Inc.

CT Guidance is Needed to Achieve Reproducible Positioning of the Mouse Head for Repeat Precision Cranial Irradiation

PubMed Central

Armour, M.; Ford, E.; Iordachita, I.; Wong, J.

2011-01-01

To study the effects of cranial irradiation, we have constructed an all-plastic mouse bed equipped with an immobilizing head holder. The bed integrates with our in-house Small Animal Radiation Research Platform (SARRP) for precision focal irradiation experiments and cone-beam CT. We assessed the reproducibility of our head holder to determine the need for CT based targeting in cranial irradiation studies. To measure the holder’s reproducibility, a C57BL/6 mouse was positioned and CT scanned nine times. Image sets were loaded into the Pinnacle3 radiation treatment planning system and were registered to one another by one investigator using rigid body alignment of the cranial regions. Rotational and translational offsets were measured. The average vector shift between scans was 0.80 ± 0.49 mm. Such a shift is too large to selectively treat subregions of the mouse brain. In response, we use onboard imaging to guide cranial irradiation applications that require sub-millimeter precision. PMID:20041766

CT guidance is needed to achieve reproducible positioning of the mouse head for repeat precision cranial irradiation.

PubMed

Armour, M; Ford, E; Iordachita, I; Wong, J

2010-01-01

To study the effects of cranial irradiation, we have constructed an all-plastic mouse bed equipped with an immobilizing head holder. The bed integrates with our in-house Small Animal Radiation Research Platform (SARRP) for precision focal irradiation experiments and cone-beam CT. We assessed the reproducibility of our head holder to determine the need for CT-based targeting in cranial irradiation studies. To measure the holder's reproducibility, a C57BL/6 mouse was positioned and CT-scanned nine times. Image sets were loaded into the Pinnacle(3) radiation treatment planning system and were registered to one another by one investigator using rigid body alignment of the cranial regions. Rotational and translational offsets were measured. The average vector shift between scans was 0.80 +/- 0.49 mm. Such a shift is too large to selectively treat subregions of the mouse brain. In response, we use onboard imaging to guide cranial irradiation applications that require sub-millimeter precision.

Laser-Based Slam with Efficient Occupancy Likelihood Map Learning for Dynamic Indoor Scenes

NASA Astrophysics Data System (ADS)

Li, Li; Yao, Jian; Xie, Renping; Tu, Jinge; Feng, Chen

2016-06-01

Location-Based Services (LBS) have attracted growing attention in recent years, especially in indoor environments. The fundamental technique of LBS is the map building for unknown environments, this technique also named as simultaneous localization and mapping (SLAM) in robotic society. In this paper, we propose a novel approach for SLAMin dynamic indoor scenes based on a 2D laser scanner mounted on a mobile Unmanned Ground Vehicle (UGV) with the help of the grid-based occupancy likelihood map. Instead of applying scan matching in two adjacent scans, we propose to match current scan with the occupancy likelihood map learned from all previous scans in multiple scales to avoid the accumulation of matching errors. Due to that the acquisition of the points in a scan is sequential but not simultaneous, there unavoidably exists the scan distortion at different extents. To compensate the scan distortion caused by the motion of the UGV, we propose to integrate a velocity of a laser range finder (LRF) into the scan matching optimization framework. Besides, to reduce the effect of dynamic objects such as walking pedestrians often existed in indoor scenes as much as possible, we propose a new occupancy likelihood map learning strategy by increasing or decreasing the probability of each occupancy grid after each scan matching. Experimental results in several challenged indoor scenes demonstrate that our proposed approach is capable of providing high-precision SLAM results.

Effect of the atmosphere on the color coordinates of sunlit surfaces

NASA Astrophysics Data System (ADS)

Willers, Cornelius J.; Viljoen, Johan W.

2016-02-01

Aerosol attenuation in the atmosphere has a relatively weak spectral variation compared to molecular absorption. However, the solar spectral irradiance differs considerably for the sun at high zenith angles versus the sun at low zenith angles. The perceived color of a sunlit object depends on the object's spectral reflectivity as well as the irradiance spectrum. The color coordinates of the sunlit object, hence also the color balance in a scene, shift with changes in the solar zenith angle. The work reported here does not claim accurate color measurement. With proper calibration mobile phones may provide reasonably accurate color measurement, but the mobile phones used for taking these pictures and videos are not scientific instruments and were not calibrated. The focus here is on the relative shift of the observed colors, rather than absolute color. The work in this paper entails the theoretical analysis of color coordinates of surfaces and how they change for different colored surfaces. Then follows three separate investigations: (1) Analysis of a number of detailed atmospheric radiative transfer code (Modtran) runs to show from the theory how color coordinates should change. (2) Analysis of a still image showing how the colors of two sample surfaces vary between sunlit and shaded areas. (3) Time lapse video recordings showing how the color coordinates of a few surfaces change as a function of time of day. Both the theoretical and experimental work shows distinct shifts in color as function of atmospheric conditions. The Modtran simulations demonstrate the effect from clear atmospheric conditions (no aerosol) to low visibility conditions (5 km visibility). Even under moderate atmospheric conditions the effect was surprisingly large. The experimental work indicated significant shifts during the diurnal cycle.

Analysis of heterogeneous water vapor uptake by metal iodide cluster ions via differential mobility analysis-mass spectrometry

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

Oberreit, Derek; Fluid Measurement Technologies, Inc., Saint Paul, Minnesota 55110; Rawat, Vivek K.

The sorption of vapor molecules onto pre-existing nanometer sized clusters is of importance in understanding particle formation and growth in gas phase environments and devising gas phase separation schemes. Here, we apply a differential mobility analyzer-mass spectrometer based approach to observe directly the sorption of vapor molecules onto iodide cluster ions of the form (MI){sub x}M{sup +} (x = 1-13, M = Na, K, Rb, or Cs) in air at 300 K and with water saturation ratios in the 0.01-0.64 range. The extent of vapor sorption is quantified in measurements by the shift in collision cross section (CCS) for eachmore » ion. We find that CCS measurements are sensitive enough to detect the transient binding of several vapor molecules to clusters, which shift CCSs by only several percent. At the same time, for the highest saturation ratios examined, we observed CCS shifts of up to 45%. For x < 4, cesium, rubidium, and potassium iodide cluster ions are found to uptake water to a similar extent, while sodium iodide clusters uptake less water. For x ≥ 4, sodium iodide cluster ions uptake proportionally more water vapor than rubidium and potassium iodide cluster ions, while cesium iodide ions exhibit less uptake. Measured CCS shifts are compared to predictions based upon a Kelvin-Thomson-Raoult (KTR) model as well as a Langmuir adsorption model. We find that the Langmuir adsorption model can be fit well to measurements. Meanwhile, KTR predictions deviate from measurements, which suggests that the earliest stages of vapor uptake by nanometer scale species are not well described by the KTR model.« less

Size dependent bandgap of molecular beam epitaxy grown InN quantum dots measured by scanning tunneling spectroscopy

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

Kumar, Mahesh; Roul, Basanta; Central Research Laboratory, Bharat Electronics, Bangalore-560013

InN quantum dots (QDs) were grown on Si (111) by epitaxial Stranski-Krastanow growth mode using plasma-assisted molecular beam epitaxy. Single-crystalline wurtzite structure of InN QDs was verified by the x-ray diffraction and transmission electron microscopy. Scanning tunneling microscopy has been used to probe the structural aspects of QDs. A surface bandgap of InN QDs was estimated from scanning tunneling spectroscopy (STS) I-V curves and found that it is strongly dependent on the size of QDs. The observed size-dependent STS bandgap energy shifts with diameter and height were theoretical explained based on an effective mass approximation with finite-depth square-well potential model.

Widefield and total internal reflection fluorescent structured illumination microscopy with scanning galvo mirrors

NASA Astrophysics Data System (ADS)

Chen, Youhua; Cao, Ruizhi; Liu, Wenjie; Zhu, Dazhao; Zhang, Zhiming; Kuang, Cuifang; Liu, Xu

2018-04-01

We present an alternative approach to realize structured illumination microscopy (SIM), which is capable for live cell imaging. The prototype utilizes two sets of scanning galvo mirrors, a polarization converter and a piezo-platform to generate a fast shifted, s-polarization interfered and periodic variable illumination patterns. By changing the angle of the scanning galvanometer, we can change the position of the spots at the pupil plane of the objective lens arbitrarily, making it easy to switch between widefield and total internal reflection fluorescent-SIM mode and adapting the penetration depth in the sample. Also, a twofold resolution improvement is achieved in our experiments. The prototype offers more flexibility of pattern period and illumination orientation changing than previous systems.

Use of multidetector-row computed tomography scan to detect pannus formation in prosthetic mechanical aortic valves.

PubMed

Aladmawi, Mohamed A; Pragliola, Claudio; Vriz, Olga; Galzerano, Domenico

2017-04-01

Obstruction of a mechanical aortic valve by pannus formation at the subvalvular level is a major long-term complication of aortic valve replacement (AVR). In fact, pannus is sometime difficult to differentiate from patient-prosthesis mismatch or valve thrombosis. In most cases cine-angiography and echocardiography, either transthoracic or transesophageal, cannot correctly visualize the complication when the leaflets show a normal mobility. Recent technological refinements made this difficult diagnosis possible by ECG-gated computed tomography (CT) scan which shows adequate images in 90% of the cases and can differentiate pannus from fresh and organized thrombus.

Buffer Gas Modifiers Effect Resolution in Ion Mobility Spectrometry through Selective Ion-Molecule Clustering Reactions

PubMed Central

Fernández-Maestre, Roberto; Wu, Ching; Hill, Herbert H.

2013-01-01

RATIONALE When polar molecules (modifiers) are introduced into the buffer gas of an ion mobility spectrometer, most ion mobilities decrease due to the formation of ion-modifier clusters. METHODS We used ethyl lactate, nitrobenzene, 2-butanol, and tetrahydrofuran-2-carbonitrile as buffer gas modifiers and electrospray ionization ion mobility spectrometry (IMS) coupled to quadrupole mass spectrometry. Ethyl lactate, nitrobenzene, and tetrahydrofuran-2-carbonitrile had not been tested as buffer gas modifiers and 2-butanol had not been used with basic amino acids. RESULTS The ion mobilities of several diamines (arginine, histidine, lysine, and atenolol) were not affected or only slightly reduced when these modifiers were introduced into the buffer gas (3.4% average reduction in an analyte's mobility for the three modifiers). Intramolecular bridges caused limited change in the ion mobilities of diamines when modifiers were added to the buffer gas; these bridges hindered the attachment of modifier molecules to the positive charge of ions and delocalized the charge, which deterred clustering. There was also a tendency towards large changes in ion mobility when the mass of the analyte decreased; ethanolamine, the smallest compound tested, had the largest reduction in ion mobility with the introduction of modifiers into the buffer gas (61%). These differences in mobilities, together with the lack of shift in bridge-forming ions, were used to separate ions that overlapped in IMS, such as isoleucine and lysine, and arginine and phenylalanine, and made possible the prediction of separation or not of overlapping ions. CONCLUSIONS The introduction of modifiers into the buffer gas in IMS can selectively alter the mobilities of analytes to aid in compound identification and/or enable the separation of overlapping analyte peaks. PMID:22956312

Significant Transient Mobility of Platinum Clusters via a Hot Precursor State on the Alumina Surface.

PubMed

Beniya, Atsushi; Hirata, Hirohito; Watanabe, Yoshihide

2016-11-17

Relaxation dynamics of hot metal clusters on oxide surfaces play a crucial role in a variety of physical and chemical processes. However, their transient mobility has not been investigated as much as other systems such as atoms and molecules on metal surfaces due to experimental difficulties. To study the role of the transient mobility of clusters on the oxide surface, we investigated the initial adsorption process of size-selected Pt clusters on a thin Al 2 O 3 film. Soft-landing the size-selected clusters while suppressing the thermal migration resulted in the transient migration controlling the initial adsorption states as an isolated and aggregated cluster, as revealed using scanning tunneling microscopy. We demonstrate that transient migration significantly contributes to the initial cluster adsorption process; the cross section for aggregation is seven times larger than the expected value from geometrical considerations, indicating that metal clusters are highly mobile during a energy dissipation process on the oxide surface.

Room-temperature mobility above 2200 cm{sup 2}/V·s of two-dimensional electron gas in a sharp-interface AlGaN/GaN heterostructure

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

Chen, Jr-Tai, E-mail: jrche@ifm.liu.se; Persson, Ingemar; Nilsson, Daniel

A high mobility of 2250 cm{sup 2}/V·s of a two-dimensional electron gas (2DEG) in a metalorganic chemical vapor deposition-grown AlGaN/GaN heterostructure was demonstrated. The mobility enhancement was a result of better electron confinement due to a sharp AlGaN/GaN interface, as confirmed by scanning transmission electron microscopy analysis, not owing to the formation of a traditional thin AlN exclusion layer. Moreover, we found that the electron mobility in the sharp-interface heterostructures can sustain above 2000 cm{sup 2}/V·s for a wide range of 2DEG densities. Finally, it is promising that the sharp-interface AlGaN/GaN heterostructure would enable low contact resistance fabrication, less impurity-related scattering, andmore » trapping than the AlGaN/AlN/GaN heterostructure, as the high-impurity-contained AlN is removed.« less

AlGaN/GaN high electron mobility transistor grown on GaN template substrate by molecule beam epitaxy system

NASA Astrophysics Data System (ADS)

Tsai, Jenn-Kai; Chen, Y. L.; Gau, M. H.; Pang, W. Y.; Hsu, Y. C.; Lo, Ikai; Hsieh, C. H.

2008-03-01

In this study, AlGaN/GaN high electron mobility transistor (HEMT) structure was grow on GaN template substrate radio frequency plasma assisted molecular beam epitaxy (MBE) equipped with an EPI UNI-Bulb nitrogen plasma source. The undoped GaN template substrate was grown on c-sapphire substrate by metal organic vapor phase epitaxy system (MOPVD). After growth of MOVPE and MBE, the samples are characterized by double crystal X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (SEM), atomic force microscopy (AFM), and Hall effect measurements. We found that the RMS roughness of template substrate play the major role in got the high value of mobility on AlGaN/GaN HEMT. When the roughness was lower than 0.77 nm in a 25 μm x 25 μm area, the mobility of HEMT at the temperature of 77 K was over 10000 cm^2/Vs.

Large Scale Textured Mesh Reconstruction from Mobile Mapping Images and LIDAR Scans

NASA Astrophysics Data System (ADS)

Boussaha, M.; Vallet, B.; Rives, P.

2018-05-01

The representation of 3D geometric and photometric information of the real world is one of the most challenging and extensively studied research topics in the photogrammetry and robotics communities. In this paper, we present a fully automatic framework for 3D high quality large scale urban texture mapping using oriented images and LiDAR scans acquired by a terrestrial Mobile Mapping System (MMS). First, the acquired points and images are sliced into temporal chunks ensuring a reasonable size and time consistency between geometry (points) and photometry (images). Then, a simple, fast and scalable 3D surface reconstruction relying on the sensor space topology is performed on each chunk after an isotropic sampling of the point cloud obtained from the raw LiDAR scans. Finally, the algorithm proposed in (Waechter et al., 2014) is adapted to texture the reconstructed surface with the images acquired simultaneously, ensuring a high quality texture with no seams and global color adjustment. We evaluate our full pipeline on a dataset of 17 km of acquisition in Rouen, France resulting in nearly 2 billion points and 40000 full HD images. We are able to reconstruct and texture the whole acquisition in less than 30 computing hours, the entire process being highly parallel as each chunk can be processed independently in a separate thread or computer.

Correlation of proton irradiation induced threshold voltage shifts to deep level traps in AlGaN/GaN heterostructures

NASA Astrophysics Data System (ADS)

Zhang, Z.; Cardwell, D.; Sasikumar, A.; Kyle, E. C. H.; Chen, J.; Zhang, E. X.; Fleetwood, D. M.; Schrimpf, R. D.; Speck, J. S.; Arehart, A. R.; Ringel, S. A.

2016-04-01

The impact of proton irradiation on the threshold voltage (VT) of AlGaN/GaN heterostructures is systematically investigated to enhance the understanding of a primary component of the degradation of irradiated high electron mobility transistors. The value of VT was found to increase monotonically as a function of 1.8 MeV proton fluence in a sub-linear manner reaching 0.63 V at a fluence of 1 × 1014 cm-2. Silvaco Atlas simulations of VT shifts caused by GaN buffer traps using experimentally measured introduction rates, and energy levels closely match the experimental results. Different buffer designs lead to different VT dependences on proton irradiation, confirming that deep, acceptor-like defects in the GaN buffer are primarily responsible for the observed VT shifts. The proton irradiation induced VT shifts are found to depend on the barrier thickness in a linear fashion; thus, scaling the barrier thickness could be an effective way to reduce such degradation.

Making value a priority: how this paradigm shift is changing the landscape in health care.

PubMed

Kimberly, John; Cronk, Imran

2016-10-01

The world of health care is changing dramatically, as reflected in the number, magnitude, and scope of innovative new approaches-to how illness is treated and how better health is promoted-that are being implemented around the globe. The changes triggered by these initiatives affect both how care is organized, managed, and paid for and the kinds of approaches that are being developed to keep people healthy. Underlying these changes is a more fundamental paradigm shift, a shift in the priority given to "value" in the formulation of policy and management practice. This brief essay highlights five trends that are central in this shift: increasing emphasis on health promotion, movement toward value-based payment, advances in digital/mobile technology, exploitation of big data, and changes in support for biomedical research. Each of these has its own value controversies, and the individual impact of each is impossible to predict. Collectively, however, their impact is likely to be significant. © 2016 New York Academy of Sciences.

Childhood Family Structure and Intergenerational Income Mobility in the United States

PubMed Central

2018-01-01

The declining prevalence of two-parent families helped increase income inequality over recent decades. Does family structure also condition how economic (dis)advantages pass from parents to children? If so, shifts in the organization of family life may contribute to enduring inequality between groups defined by childhood family structure. Using National Longitudinal Survey of Youth data, I combine parametric and nonparametric methods to reveal how family structure moderates intergenerational income mobility in the United States. I find that individuals raised outside stable two-parent homes are much more mobile than individuals from stable two-parent families. Mobility increases with the number of family transitions but does not vary with children’s time spent coresiding with both parents or stepparents conditional on a transition. However, this mobility indicates insecurity, not opportunity. Difficulties maintaining middle-class incomes create downward mobility among people raised outside stable two-parent homes. Regardless of parental income, these people are relatively likely to become low-income adults, reflecting a new form of perverse equality. People raised outside stable two-parent families are also less likely to become high-income adults than people from stable two-parent homes. Mobility differences account for about one-quarter of family-structure inequalities in income at the bottom of the income distribution and more than one-third of these inequalities at the top. PMID:28315158

Effect of Phosphorylation on Interactions between Transmembrane Domains of SERCA and Phospholamban.

PubMed

Martin, Peter D; James, Zachary M; Thomas, David D

2018-06-05

We have used site-directed spin labeling and electron paramagnetic resonance (EPR) to map interactions between the transmembrane (TM) domains of the sarcoplasmic reticulum Ca 2+ -ATPase (SERCA) and phospholamban (PLB) as affected by PLB phosphorylation. In the cardiac sarcoplasmic reticulum, PLB binding to SERCA results in Ca-dependent enzyme inhibition, which is reversed by PLB phosphorylation at Ser16. Previous spectroscopic studies on SERCA-PLB have largely focused on the cytoplasmic domain of PLB, showing that phosphorylation induces a structural shift in this domain relative to SERCA. However, SERCA inhibition is due entirely to TM domain interactions. Therefore, we focus here on PLB's TM domain, attaching Cys-reactive spin labels at five different positions. In each case, continuous-wave EPR indicated moderate spin-label mobility, with the addition of SERCA revealing two populations, one indistinguishable from PLB alone and another with more restricted rotational mobility, presumably due to SERCA-binding. Phosphorylation had no effect on the rotational mobility of either component but significantly decreased the mole fraction of the restricted component. Solvent-accessibility experiments using power-saturation EPR and saturation-recovery EPR confirmed that these two spectral components were SERCA-bound and unbound PLB and showed that phosphorylation increased the overall lipid accessibility of the TM domain by increasing the fraction of unbound PLB. However-based on these results-at physiological levels of SERCA and PLB, most SERCA would have bound PLB even after phosphorylation. Additionally, no structural shift in the TM domain of SERCA-bound PLB was detected, as there were no significant changes in membrane insertion depth or its accessibility. Therefore, we conclude that under physiological conditions, the phosphorylation of PLB induces little or no change in the interaction of the TM domain with SERCA, so relief of inhibition is predominantly due to the previously observed structural shift in the cytoplasmic domain. Copyright © 2018 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Carbon Mobility at Subduction Interfaces via Deformation-Enhanced Fluid Infiltration: Evidence from the Swiss/Italian Alps

NASA Astrophysics Data System (ADS)

Jaeckel, K. P.; Bebout, G. E.; Angiboust, S.

2016-12-01

The interplay between fluid flow and deformation along subduction interfaces, and the extent to which deformation-enhanced fluid infiltration can drive decarbonation and carbonate dissolution, remain poorly understood. Recent work on HP/UHP decarbonation in W. Alps suites has indicated that, in intact volumes of metasediment, metabasalt, and ophicarbonate away from major shear zones and with few veins, carbonate is largely retained to 80-90 km depths (Cook-Kollars et al., 2014; Collins et al., 2015; Chem. Geol.). Yet uncertain is whether forearc fluid infiltration focused in intensely sheared and fractured zones could result in greater mobilization of C from subducting sections, in quantities sufficient to impact subduction zone C cycling. Lower-plate rocks at Arosa and Dent Blanche interface exposures (Bachmann et al., 2009, JGR; Angiboust et al., 2015, G3) are primarily calc-schist intercalated with meta-ultramafic and metamafic schist and contain carbonate-bearing veins of varying abundance and texture. At some localities, these sections contain blocks of carbonate, metabasalt, and upper-plate gneiss. Strongly deformed veins concordant with the foliation parallel to the thrust interface commonly contain carbonate and quartz. In highly sheared regions in the Arosa Zone, δ18O(VSMOW) values of some host-rocks and veins are shifted from +20 ± 2‰, values observed regionally for the Schistes Lustres, to values of +11 to +13‰. These shifts can be explained by interaction with externally-derived H2O-rich fluids with δ18O of +9 to +11‰. Smaller datasets for Dent Blanche localities hint at similar δ18O shifts. Most of these rocks contain little evidence of C release by decarbonation reactions. Evidence exists for local-scale dissolution of carbonate, during pressure solution, and carbonate-bearing veins reflect C mobility in fluids. Ongoing work assesses whether volumes of carbonate removed in some regions balance with those precipitated nearby in veins and pressure shadows.

Multi-Instrument Manager Tool for Data Acquisition and Merging of Optical and Electrical Mobility Size Distributions

NASA Astrophysics Data System (ADS)

Tritscher, Torsten; Koched, Amine; Han, Hee-Siew; Filimundi, Eric; Johnson, Tim; Elzey, Sherrie; Avenido, Aaron; Kykal, Carsten; Bischof, Oliver F.

2015-05-01

Electrical mobility classification (EC) followed by Condensation Particle Counter (CPC) detection is the technique combined in Scanning Mobility Particle Sizers(SMPS) to retrieve nanoparticle size distributions in the range from 2.5 nm to 1 μm. The detectable size range of SMPS systems can be extended by the addition of an Optical Particle Sizer(OPS) that covers larger sizes from 300 nm to 10 μm. This optical sizing method reports an optical equivalent diameter, which is often different from the electrical mobility diameter measured by the standard SMPS technique. Multi-Instrument Manager (MIMTM) software developed by TSI incorporates algorithms that facilitate merging SMPS data sets with data based on optical equivalent diameter to compile single, wide-range size distributions. Here we present MIM 2.0, the next-generation of the data merging tool that offers many advanced features for data merging and post-processing. MIM 2.0 allows direct data acquisition with OPS and NanoScan SMPS instruments to retrieve real-time particle size distributions from 10 nm to 10 μm, which we show in a case study at a fireplace. The merged data can be adjusted using one of the merging options, which automatically determines an overall aerosol effective refractive index. As a result an indirect and average characterization of aerosol optical and shape properties is possible. The merging tool allows several pre-settings, data averaging and adjustments, as well as the export of data sets and fitted graphs. MIM 2.0 also features several post-processing options for SMPS data and differences can be visualized in a multi-peak sample over a narrow size range.

[Agrarian change and regional settling in Chile].

PubMed

Canales Ceron, A

1996-01-01

"This study analyzes the effect of agrarian change on regional settling dynamics in Chile during the last 35 years. The transformations of agrarian structure have produced important changes in the spatial configuration of country-city relations, particularly regarding the new features of rural-urban migration in regional contexts. Whereas until the sixties rural-urban migration was associated with an occupational shift from agriculture to urban employment, after the seventies this relation practically disappeared, leaving a virtual disassociation between the territorial mobility of the population and the occupational mobility of the labor force. This disassociation is a central trait of the current regional pattern of country-city relations." (SUMMARY IN ENG) excerpt

A pilot study of an mHealth application for healthcare workers: poor uptake despite high reported acceptability at a rural South African community-based MDR-TB treatment program.

PubMed

Chaiyachati, Krisda H; Loveday, Marian; Lorenz, Stephen; Lesh, Neal; Larkan, Lee-Megan; Cinti, Sandro; Friedland, Gerald H; Haberer, Jessica E

2013-01-01

As the South African province of KwaZulu-Natal addresses a growing multidrug-resistant tuberculosis (MDR-TB) epidemic by shifting care and treatment from trained specialty centers to community hospitals, delivering and monitoring MDR-TB therapy has presented new challenges. In particular, tracking and reporting adverse clinical events have been difficult for mobile healthcare workers (HCWs), trained health professionals who travel daily to patient homes to administer and monitor therapy. We designed and piloted a mobile phone application (Mobilize) for mobile HCWs that electronically standardized the recording and tracking of MDR-TB patients on low-cost, functional phones. We assess the acceptability and feasibility of using Mobilize to record and submit adverse events forms weekly during the intensive phase of MDR-TB therapy and evaluate mobile HCW perceptions throughout the pilot period. All five mobile HCWs at one site were trained and provided with phones. Utilizing a mixed-methods evaluation, mobile HCWs' usage patterns were tracked electronically for seven months and analyzed. Qualitative focus groups and questionnaires were designed to understand the impact of mobile phone technology on the work environment. Mobile HCWs submitted nine of 33 (27%) expected adverse events forms, conflicting with qualitative results in which mobile HCWs stated that Mobilize improved adverse events communication, helped their daily workflow, and could be successfully expanded to other health interventions. When presented with the conflict between their expressed views and actual practice, mobile HCWs cited forgetfulness and believed patients should take more responsibility for their own care. This pilot experience demonstrated poor uptake by HCWs despite positive responses to using mHealth. Though our results should be interpreted cautiously because of the small number of mobile HCWs and MDR-TB patients in this study, we recommend carefully exploring the motivations of HCWs and technologic enhancements prior to scaling new mHealth initiatives in resource poor settings.

Effects of Frequency Drift on the Quantification of Gamma-Aminobutyric Acid Using MEGA-PRESS

PubMed Central

Tsai, Shang-Yueh; Fang, Chun-Hao; Wu, Thai-Yu; Lin, Yi-Ru

2016-01-01

The MEGA-PRESS method is the most common method used to measure γ-aminobutyric acid (GABA) in the brain at 3T. It has been shown that the underestimation of the GABA signal due to B0 drift up to 1.22 Hz/min can be reduced by post-frequency alignment. In this study, we show that the underestimation of GABA can still occur even with post frequency alignment when the B0 drift is up to 3.93 Hz/min. The underestimation can be reduced by applying a frequency shift threshold. A total of 23 subjects were scanned twice to assess the short-term reproducibility, and 14 of them were scanned again after 2–8 weeks to evaluate the long-term reproducibility. A linear regression analysis of the quantified GABA versus the frequency shift showed a negative correlation (P < 0.01). Underestimation of the GABA signal was found. When a frequency shift threshold of 0.125 ppm (15.5 Hz or 1.79 Hz/min) was applied, the linear regression showed no statistically significant difference (P > 0.05). Therefore, a frequency shift threshold at 0.125 ppm (15.5 Hz) can be used to reduce underestimation during GABA quantification. For data with a B0 drift up to 3.93 Hz/min, the coefficients of variance of short-term and long-term reproducibility for the GABA quantification were less than 10% when the frequency threshold was applied. PMID:27079873

Adaptive optimization by 6 DOF robotic couch in prostate volumetric IMRT treatment: rototranslational shift and dosimetric consequences

PubMed Central

Placidi, Lorenzo; Azario, Luigi; Mattiucci, Gian Carlo; Greco, Francesca; Damiani, Andrea; Mantini, Giovanna; Frascino, Vincenzo; Piermattei, Angelo; Valentini, Vincenzo; Balducci, Mario

2015-01-01

The purpose of this study was to investigate the magnitude and dosimetric relevance of translational and rotational shifts on IGRT prostate volumetric‐modulated arc therapy (VMAT) using Protura six degrees of freedom (DOF) Robotic Patient Positioning System. Patients with cT3aN0M0 prostate cancer, treated with VMAT simultaneous integrated boost (VMAT‐SIB), were enrolled. PTV2 was obtained adding 0.7 cm margin to seminal vesicles base (CTV2), while PTV1 adding to prostate (CTV1) 0.7 cm margin in all directions, except 1.2 cm, as caudal margin. A daily CBCT was acquired before dose delivery. The translational and rotational displacements were corrected through Protura Robotic Couch, collected and applied to the simulation CT to obtain a translated CT (tCT) and a rototranslated CT (rtCT) on which we recalculated the initial treatment plan (TP). We analyzed the correlation between dosimetric coverage, organs at risk (OAR) sparing, and translational or rotational displacements. The dosimetric impact of a rototranslational correction was calculated. From October 2012 to September 2013, a total of 263 CBCT scans from 12 patients were collected. Translational shifts were <5mm in 81% of patients and the rotational shifts were <2∘ in 93% of patient scans. The dosimetric analysis was performed on 172 CBCT scans and calculating 344 VMAT‐TP. Two significant linear correlations were observed between yaw and the V20 femoral heads and between pitch rotation and V50 rectum (p<0.001); rototranslational correction seems to impact more on PTV2 than on PTV1, especially when margins are reduced. Rotational errors are of dosimetric significance in sparing OAR and in target coverage. This is relevant for femoral heads and rectum because of major distance from isocenter, and for seminal vesicles because of irregular shape. No correlation was observed between translational and rotational errors. A study considering the intrafractional error and the deformable registration is ongoing. PACS number: 87.55.de PMID:26699314

Nontraumatic tibial polyethylene insert cone fracture in mobile-bearing posterior-stabilized total knee arthroplasty.

PubMed

Tanikake, Yohei; Hayashi, Koji; Ogawa, Munehiro; Inagaki, Yusuke; Kawate, Kenji; Tomita, Tetsuya; Tanaka, Yasuhito

2016-12-01

A 72-year-old male patient underwent mobile-bearing posterior-stabilized total knee arthroplasty for osteoarthritis. He experienced a nontraumatic polyethylene tibial insert cone fracture 27 months after surgery. Scanning electron microscopy of the fracture surface of the tibial insert cone suggested progress of ductile breaking from the posterior toward the anterior of the cone due to repeated longitudinal bending stress, leading to fatigue breaking at the anterior side of the cone, followed by the tibial insert cone fracture at the anterior side of the cone, resulting in fracture at the base of the cone. This analysis shows the risk of tibial insert cone fracture due to longitudinal stress in mobile-bearing posterior-stabilized total knee arthroplasty in which an insert is designed to highly conform to the femoral component.

A CityGML extension for traffic-sign objects that guides the automatic processing of data collected using Mobile Mapping technology

NASA Astrophysics Data System (ADS)

Varela-González, M.; Riveiro, B.; Arias-Sánchez, P.; González-Jorge, H.; Martínez-Sánchez, J.

2014-11-01

The rapid evolution of integral schemes, accounting for geometric and semantic data, has been importantly motivated by the advances in the last decade in mobile laser scanning technology; automation in data processing has also recently influenced the expansion of the new model concepts. This paper reviews some important issues involved in the new paradigms of city 3D modelling: an interoperable schema for city 3D modelling (cityGML) and mobile mapping technology to provide the features that composing the city model. This paper focuses in traffic signs, discussing their characterization using cityGML in order to ease the implementation of LiDAR technology in road management software, as well as analysing some limitations of the current technology in the labour of automatic detection and classification.

A characterization of autumn nocturnal migration detected by weather surveillance radars in the northeastern USA.

PubMed

Farnsworth, Andrew; Van DOREN, Benjamin M; Hochachka, Wesley M; Sheldon, Daniel; Winner, Kevin; Irvine, Jed; Geevarghese, Jeffrey; Kelling, Steve

2016-04-01

Billions of birds migrate at night over North America each year. However, few studies have described the phenology of these movements, such as magnitudes, directions, and speeds, for more than one migration season and at regional scales. In this study, we characterize density, direction, and speed of nocturnally migrating birds using data from 13 weather surveillance radars in the autumns of 2010 and 2011 in the northeastern USA. After screening radar data to remove precipitation, we applied a recently developed algorithm for characterizing velocity profiles with previously developed methods to document bird migration. Many hourly radar scans contained windborne "contamination," and these scans also exhibited generally low overall reflectivities. Hourly scans dominated by birds showed nightly and seasonal patterns that differed markedly from those of low reflectivity scans. Bird migration occurred during many nights, but a smaller number of nights with large movements of birds defined regional nocturnal migration. Densities varied by date, time, and location but peaked in the second and third deciles of night during the autumn period when the most birds were migrating. Migration track (the direction to which birds moved) shifted within nights from south-southwesterly to southwesterly during the seasonal migration peaks; this shift was not consistent with a similar shift in wind direction. Migration speeds varied within nights, although not closely with wind speed. Airspeeds increased during the night; groundspeeds were highest between the second and third deciles of night, when the greatest density of birds was migrating. Airspeeds and groundspeeds increased during the fall season, although groundspeeds fluctuated considerably with prevailing winds. Significant positive correlations characterized relationships among bird densities at southern coastal radar stations and northern inland radar stations. The quantitative descriptions of broadscale nocturnal migration patterns presented here will be essential for biological and conservation applications. These descriptions help to define migration phenology in time and space, fill knowledge gaps in avian annual cycles, and are useful for monitoring long-term population trends of migrants. Furthermore, these descriptions will aid in assessing potential risks to migrants, particularly from structures with which birds collide and artificial lighting that disorients migrants.

Current mHealth Technologies for Physical Activity Assessment and Promotion

PubMed Central

O’Reilly, Gillian A.; Spruijt-Metz, Donna

2014-01-01

Context Novel mobile assessment and intervention capabilities are changing the face of physical activity (PA) research. A comprehensive systematic review of how mobile technology has been used for measuring PA and promoting PA behavior change is needed. Evidence acquisition Article collection was conducted using six databases from February to June 2012 with search terms related to mobile technology and PA. Articles that described the use of mobile technologies for PA assessment, sedentary behavior assessment, and/or interventions for PA behavior change were included. Articles were screened for inclusion and study information was extracted. Evidence synthesis Analyses were conducted from June to September 2012. Mobile phone–based journals and questionnaires, short message service (SMS) prompts, and on-body PA sensing systems were the mobile technologies most utilized. Results indicate that mobile journals and questionnaires are effective PA self-report measurement tools. Intervention studies that reported successful promotion of PA behavior change employed SMS communication, mobile journaling, or both SMS and mobile journaling. Conclusions mHealth technologies are increasingly being employed to assess and intervene on PA in clinical, epidemiologic, and intervention research. The wide variations in technologies used and outcomes measured limit comparability across studies, and hamper identification of the most promising technologies. Further, the pace of technologic advancement currently outstrips that of scientific inquiry. New adaptive, sequential research designs that take advantage of ongoing technology development are needed. At the same time, scientific norms must shift to accept “smart,” adaptive, iterative, evidence-based assessment and intervention technologies that will, by nature, improve during implementation. PMID:24050427

Current mHealth technologies for physical activity assessment and promotion.

PubMed

O'Reilly, Gillian A; Spruijt-Metz, Donna

2013-10-01

Novel mobile assessment and intervention capabilities are changing the face of physical activity (PA) research. A comprehensive systematic review of how mobile technology has been used for measuring PA and promoting PA behavior change is needed. Article collection was conducted using six databases from February to June 2012 with search terms related to mobile technology and PA. Articles that described the use of mobile technologies for PA assessment, sedentary behavior assessment, and/or interventions for PA behavior change were included. Articles were screened for inclusion and study information was extracted. Analyses were conducted from June to September 2012. Mobile phone-based journals and questionnaires, short message service (SMS) prompts, and on-body PA sensing systems were the mobile technologies most utilized. Results indicate that mobile journals and questionnaires are effective PA self-report measurement tools. Intervention studies that reported successful promotion of PA behavior change employed SMS communication, mobile journaling, or both SMS and mobile journaling. mHealth technologies are increasingly being employed to assess and intervene on PA in clinical, epidemiologic, and intervention research. The wide variations in technologies used and outcomes measured limit comparability across studies, and hamper identification of the most promising technologies. Further, the pace of technologic advancement currently outstrips that of scientific inquiry. New adaptive, sequential research designs that take advantage of ongoing technology development are needed. At the same time, scientific norms must shift to accept "smart," adaptive, iterative, evidence-based assessment and intervention technologies that will, by nature, improve during implementation. © 2013 American Journal of Preventive Medicine.

CONTINUOUS MEASUREMENT OF FINE AND ULTRAFINE PARTICULATE MATTER, CRITERIA POLLUTANTS AND METEOROLOGICAL CONDITIONS IN URBAN EL PASO, TEXAS

EPA Science Inventory

Continuous measurements of aerosol size distributions were made in El Paso, TX, for a period in winter 1999. Size distribution measurements were performed at two urban locations in El Paso using two pairs of the scanning mobility particle sizer and the aerodynamic particle si...

Miniature, mobile X-ray computed radiography system

DOEpatents

Watson, Scott A; Rose, Evan A

2017-03-07

A miniature, portable x-ray system may be configured to scan images stored on a phosphor. A flash circuit may be configured to project red light onto a phosphor and receive blue light from the phosphor. A digital monochrome camera may be configured to receive the blue light to capture an article near the phosphor.

An Automated Road Roughness Detection from Mobile Laser Scanning Data

NASA Astrophysics Data System (ADS)

Kumar, P.; Angelats, E.

2017-05-01

Rough roads influence the safety of the road users as accident rate increases with increasing unevenness of the road surface. Road roughness regions are required to be efficiently detected and located in order to ensure their maintenance. Mobile Laser Scanning (MLS) systems provide a rapid and cost-effective alternative by providing accurate and dense point cloud data along route corridor. In this paper, an automated algorithm is presented for detecting road roughness from MLS data. The presented algorithm is based on interpolating smooth intensity raster surface from LiDAR point cloud data using point thinning process. The interpolated surface is further processed using morphological and multi-level Otsu thresholding operations to identify candidate road roughness regions. The candidate regions are finally filtered based on spatial density and standard deviation of elevation criteria to detect the roughness along the road surface. The test results of road roughness detection algorithm on two road sections are presented. The developed approach can be used to provide comprehensive information to road authorities in order to schedule maintenance and ensure maximum safety conditions for road users.

3D local feature BKD to extract road information from mobile laser scanning point clouds

NASA Astrophysics Data System (ADS)

Yang, Bisheng; Liu, Yuan; Dong, Zhen; Liang, Fuxun; Li, Bijun; Peng, Xiangyang

2017-08-01

Extracting road information from point clouds obtained through mobile laser scanning (MLS) is essential for autonomous vehicle navigation, and has hence garnered a growing amount of research interest in recent years. However, the performance of such systems is seriously affected due to varying point density and noise. This paper proposes a novel three-dimensional (3D) local feature called the binary kernel descriptor (BKD) to extract road information from MLS point clouds. The BKD consists of Gaussian kernel density estimation and binarization components to encode the shape and intensity information of the 3D point clouds that are fed to a random forest classifier to extract curbs and markings on the road. These are then used to derive road information, such as the number of lanes, the lane width, and intersections. In experiments, the precision and recall of the proposed feature for the detection of curbs and road markings on an urban dataset and a highway dataset were as high as 90%, thus showing that the BKD is accurate and robust against varying point density and noise.

A dual growing method for the automatic extraction of individual trees from mobile laser scanning data

NASA Astrophysics Data System (ADS)

Li, Lin; Li, Dalin; Zhu, Haihong; Li, You

2016-10-01

Street trees interlaced with other objects in cluttered point clouds of urban scenes inhibit the automatic extraction of individual trees. This paper proposes a method for the automatic extraction of individual trees from mobile laser scanning data, according to the general constitution of trees. Two components of each individual tree - a trunk and a crown can be extracted by the dual growing method. This method consists of coarse classification, through which most of artifacts are removed; the automatic selection of appropriate seeds for individual trees, by which the common manual initial setting is avoided; a dual growing process that separates one tree from others by circumscribing a trunk in an adaptive growing radius and segmenting a crown in constrained growing regions; and a refining process that draws a singular trunk from the interlaced other objects. The method is verified by two datasets with over 98% completeness and over 96% correctness. The low mean absolute percentage errors in capturing the morphological parameters of individual trees indicate that this method can output individual trees with high precision.

Towards the automatic scanning of indoors with robots.

PubMed

Adán, Antonio; Quintana, Blanca; Vázquez, Andres S; Olivares, Alberto; Parra, Eduardo; Prieto, Samuel

2015-05-19

This paper is framed in both 3D digitization and 3D data intelligent processing research fields. Our objective is focused on developing a set of techniques for the automatic creation of simple three-dimensional indoor models with mobile robots. The document presents the principal steps of the process, the experimental setup and the results achieved. We distinguish between the stages concerning intelligent data acquisition and 3D data processing. This paper is focused on the first stage. We show how the mobile robot, which carries a 3D scanner, is able to, on the one hand, make decisions about the next best scanner position and, on the other hand, navigate autonomously in the scene with the help of the data collected from earlier scans. After this stage, millions of 3D data are converted into a simplified 3D indoor model. The robot imposes a stopping criterion when the whole point cloud covers the essential parts of the scene. This system has been tested under real conditions indoors with promising results. The future is addressed to extend the method in much more complex and larger scenarios.

Laser-Based Pedestrian Tracking in Outdoor Environments by Multiple Mobile Robots

PubMed Central

Ozaki, Masataka; Kakimuma, Kei; Hashimoto, Masafumi; Takahashi, Kazuhiko

2012-01-01

This paper presents an outdoors laser-based pedestrian tracking system using a group of mobile robots located near each other. Each robot detects pedestrians from its own laser scan image using an occupancy-grid-based method, and the robot tracks the detected pedestrians via Kalman filtering and global-nearest-neighbor (GNN)-based data association. The tracking data is broadcast to multiple robots through intercommunication and is combined using the covariance intersection (CI) method. For pedestrian tracking, each robot identifies its own posture using real-time-kinematic GPS (RTK-GPS) and laser scan matching. Using our cooperative tracking method, all the robots share the tracking data with each other; hence, individual robots can always recognize pedestrians that are invisible to any other robot. The simulation and experimental results show that cooperating tracking provides the tracking performance better than conventional individual tracking does. Our tracking system functions in a decentralized manner without any central server, and therefore, this provides a degree of scalability and robustness that cannot be achieved by conventional centralized architectures. PMID:23202171

Towards the Automatic Scanning of Indoors with Robots

PubMed Central

Adán, Antonio; Quintana, Blanca; Vázquez, Andres S.; Olivares, Alberto; Parra, Eduardo; Prieto, Samuel

2015-01-01

This paper is framed in both 3D digitization and 3D data intelligent processing research fields. Our objective is focused on developing a set of techniques for the automatic creation of simple three-dimensional indoor models with mobile robots. The document presents the principal steps of the process, the experimental setup and the results achieved. We distinguish between the stages concerning intelligent data acquisition and 3D data processing. This paper is focused on the first stage. We show how the mobile robot, which carries a 3D scanner, is able to, on the one hand, make decisions about the next best scanner position and, on the other hand, navigate autonomously in the scene with the help of the data collected from earlier scans. After this stage, millions of 3D data are converted into a simplified 3D indoor model. The robot imposes a stopping criterion when the whole point cloud covers the essential parts of the scene. This system has been tested under real conditions indoors with promising results. The future is addressed to extend the method in much more complex and larger scenarios. PMID:25996513

The effect of static scanning and mobility training on mobility in people with hemianopia after stroke: A randomized controlled trial comparing standardized versus non-standardized treatment protocols

PubMed Central

2011-01-01

Background Visual loss following stroke impacts significantly on activities of daily living and is an independent risk factor for becoming dependent. Routinely, allied health clinicians provide training for visual field loss, mainly with eye movement based therapy. The effectiveness of the compensatory approach to rehabilitation remains inconclusive largely due to difficulty in validating functional outcome with the varied type and dosage of therapy received by an individual patient. This study aims to determine which treatment is more effective, a standardized approach or individualized therapy in patients with homonymous hemianopia post stroke. Methods/Design This study is a double-blind randomized controlled, multicenter trial. A standardised scanning rehabilitation program (Neuro Vision Technology (NVT) program) of 7 weeks at 3 times per week, is compared to individualized therapy recommended by clinicians. Discussion The results of the trial will provide information that could potentially inform the allocation of resources in visual rehabilitation post stroke. Trial Registration Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12610000494033 PMID:21767413

Electrophoretic mobility shift in native gels indicates calcium-dependent structural changes of neuronal calcium sensor proteins.

PubMed

Viviano, Jeffrey; Krishnan, Anuradha; Wu, Hao; Venkataraman, Venkat

2016-02-01

In proteins of the neuronal calcium sensor (NCS) family, changes in structure as well as function are brought about by the binding of calcium. In this article, we demonstrate that these structural changes, solely due to calcium binding, can be assessed through electrophoresis in native gels. The results demonstrate that the NCS proteins undergo ligand-dependent conformational changes that are detectable in native gels as a gradual decrease in mobility with increasing calcium but not other tested divalent cations such as magnesium, strontium, and barium. Surprisingly, such a gradual change over the entire tested range is exhibited only by the NCS proteins but not by other tested calcium-binding proteins such as calmodulin and S100B, indicating that the change in mobility may be linked to a unique NCS family feature--the calcium-myristoyl switch. Even within the NCS family, the changes in mobility are characteristic of the protein, indicating that the technique is sensitive to the individual features of the protein. Thus, electrophoretic mobility on native gels provides a simple and elegant method to investigate calcium (small ligand)-induced structural changes at least in the superfamily of NCS proteins. Copyright © 2015 Elsevier Inc. All rights reserved.

Random-walk mobility analysis of Lisbon's plans for the post-1755 reconstruction

NASA Astrophysics Data System (ADS)

de Sampayo, Mafalda Teixeira; Sousa-Rodrigues, David

2016-11-01

The different options for the reconstruction of the city of Lisbon in the aftermath of the 1755 earthquake are studied with an agent-based model based on randomwalks. This method gives a comparative quantitative measure of mobility of the circulation spaces within the city. The plans proposed for the city of Lisbon signified a departure from the medieval mobility city model. The intricacy of the old city circulation spaces is greatly reduced in the new plans and the mobility between different areas is substantially improved. The simulation results of the random-walk model show that those plans keeping the main force lines of the old city presented less improvement in terms ofmobility. The plans that had greater design freedom were, by contrast, easier to navigate. Lisbon's reconstruction followed a plan that included a shift in the traditional notions of mobility. This affected the daily lives of its citizens by potentiating an easy access to the waterfront, simplifying orientation and navigability. Using the random-walk model it is shown how to quantitatively measure the potential that synthetic plans have in terms of the permeability and navigability of different city public spaces.

Group-Oriented Services: A Shift towards Consumer-Managed Relationships in the Telecom Industry

NASA Astrophysics Data System (ADS)

Vrdoljak, Luka; Bojic, Iva; Podobnik, Vedran; Jezic, Gordan; Kusek, Mario

Today, telecom operators face a threefold challenge: a social challenge dealing with the evolution of the consumer lifestyle, a technological challenge dealing with ever changing ICT trends and a business challenge dealing with the need for innovative business models. This paper introduces an idea of group-oriented services, a special type of personalized telecom services, as a possible solution for all three of these challenges. A proof-of-concept service, called Agent-Based Mobile Content Brokerage, is presented and elaborated with the aim to demonstrate a shift towards consumer-managed relationships, a novel provisioning paradigm within the telecom industry.

Probing surface states in PbS nanocrystal films using pentacene field effect transistors: controlling carrier concentration and charge transport in pentacene.

PubMed

Park, Byoungnam; Whitham, Kevin; Bian, Kaifu; Lim, Yee-Fun; Hanrath, Tobias

2014-12-21

We used a bilayer field effect transistor (FET) consisting of a thin PbS nanocrystals (NCs) film interfaced with vacuum-deposited pentacene to probe trap states in NCs. We interpret the observed threshold voltage shift in context of charge carrier trapping by PbS NCs and relate the magnitude of the threshold voltage shift to the number of trapped carriers. We explored a series of NC surface ligands to modify the interface between PbS NCs and pentacene and demonstrate the impact of interface chemistry on charge carrier density and the FET mobility in a pentacene FET.

NAVIS-An UGV Indoor Positioning System Using Laser Scan Matching for Large-Area Real-Time Applications

PubMed Central

Tang, Jian.; Chen, Yuwei.; Jaakkola, Anttoni.; Liu, Jinbing.; Hyyppä, Juha.; Hyyppä, Hannu.

2014-01-01

Laser scan matching with grid-based maps is a promising tool for real-time indoor positioning of mobile Unmanned Ground Vehicles (UGVs). While there are critical implementation problems, such as the ability to estimate the position by sensing the unknown indoor environment with sufficient accuracy and low enough latency for stable vehicle control, further development work is necessary. Unfortunately, most of the existing methods employ heuristics for quick positioning in which numerous accumulated errors easily lead to loss of positioning accuracy. This severely restricts its applications in large areas and over lengthy periods of time. This paper introduces an efficient real-time mobile UGV indoor positioning system for large-area applications using laser scan matching with an improved probabilistically-motivated Maximum Likelihood Estimation (IMLE) algorithm, which is based on a multi-resolution patch-divided grid likelihood map. Compared with traditional methods, the improvements embodied in IMLE include: (a) Iterative Closed Point (ICP) preprocessing, which adaptively decreases the search scope; (b) a totally brute search matching method on multi-resolution map layers, based on the likelihood value between current laser scan and the grid map within refined search scope, adopted to obtain the global optimum position at each scan matching; and (c) a patch-divided likelihood map supporting a large indoor area. A UGV platform called NAVIS was designed, manufactured, and tested based on a low-cost robot integrating a LiDAR and an odometer sensor to verify the IMLE algorithm. A series of experiments based on simulated data and field tests with NAVIS proved that the proposed IMEL algorithm is a better way to perform local scan matching that can offer a quick and stable positioning solution with high accuracy so it can be part of a large area localization/mapping, application. The NAVIS platform can reach an updating rate of 12 Hz in a feature-rich environment and 2 Hz even in a feature-poor environment, respectively. Therefore, it can be utilized in a real-time application. PMID:24999715

NAVIS-An UGV indoor positioning system using laser scan matching for large-area real-time applications.

PubMed

Tang, Jian; Chen, Yuwei; Jaakkola, Anttoni; Liu, Jinbing; Hyyppä, Juha; Hyyppä, Hannu

2014-07-04

Laser scan matching with grid-based maps is a promising tool for real-time indoor positioning of mobile Unmanned Ground Vehicles (UGVs). While there are critical implementation problems, such as the ability to estimate the position by sensing the unknown indoor environment with sufficient accuracy and low enough latency for stable vehicle control, further development work is necessary. Unfortunately, most of the existing methods employ heuristics for quick positioning in which numerous accumulated errors easily lead to loss of positioning accuracy. This severely restricts its applications in large areas and over lengthy periods of time. This paper introduces an efficient real-time mobile UGV indoor positioning system for large-area applications using laser scan matching with an improved probabilistically-motivated Maximum Likelihood Estimation (IMLE) algorithm, which is based on a multi-resolution patch-divided grid likelihood map. Compared with traditional methods, the improvements embodied in IMLE include: (a) Iterative Closed Point (ICP) preprocessing, which adaptively decreases the search scope; (b) a totally brute search matching method on multi-resolution map layers, based on the likelihood value between current laser scan and the grid map within refined search scope, adopted to obtain the global optimum position at each scan matching; and (c) a patch-divided likelihood map supporting a large indoor area. A UGV platform called NAVIS was designed, manufactured, and tested based on a low-cost robot integrating a LiDAR and an odometer sensor to verify the IMLE algorithm. A series of experiments based on simulated data and field tests with NAVIS proved that the proposed IMEL algorithm is a better way to perform local scan matching that can offer a quick and stable positioning solution with high accuracy so it can be part of a large area localization/mapping, application. The NAVIS platform can reach an updating rate of 12 Hz in a feature-rich environment and 2 Hz even in a feature-poor environment, respectively. Therefore, it can be utilized in a real-time application.

Mobile cloud-computing-based healthcare service by noncontact ECG monitoring.

PubMed

Fong, Ee-May; Chung, Wan-Young

2013-12-02

Noncontact electrocardiogram (ECG) measurement technique has gained popularity these days owing to its noninvasive features and convenience in daily life use. This paper presents mobile cloud computing for a healthcare system where a noncontact ECG measurement method is employed to capture biomedical signals from users. Healthcare service is provided to continuously collect biomedical signals from multiple locations. To observe and analyze the ECG signals in real time, a mobile device is used as a mobile monitoring terminal. In addition, a personalized healthcare assistant is installed on the mobile device; several healthcare features such as health status summaries, medication QR code scanning, and reminders are integrated into the mobile application. Health data are being synchronized into the healthcare cloud computing service (Web server system and Web server dataset) to ensure a seamless healthcare monitoring system and anytime and anywhere coverage of network connection is available. Together with a Web page application, medical data are easily accessed by medical professionals or family members. Web page performance evaluation was conducted to ensure minimal Web server latency. The system demonstrates better availability of off-site and up-to-the-minute patient data, which can help detect health problems early and keep elderly patients out of the emergency room, thus providing a better and more comprehensive healthcare cloud computing service.

AMF3 ARM's Research Facility and MAOS at Oliktok Point Alaska

NASA Astrophysics Data System (ADS)

Helsel, F.; Ivey, M.; Dexheimer, D.; Hardesty, J.; Lucero, D. A.; Roesler, E. L.

2016-12-01

Scientific Infrastructure To Support Atmospheric Science And Aerosol Science For The Department Of Energy's Atmospheric Radiation Measurement Programs Mobile Facility 3 Located At Oliktok Point, Alaska.The Atmospheric Radiation Measurement (ARM) Program's Mobile Facility 3 (AMF3) located at Oliktok Point, Alaska is a U.S. Department of Energy (DOE) site designed to collect data to determine the impact that clouds and aerosols have on solar radiation. The site provides a scientific infrastructure and data archives for the international Arctic research community. The infrastructure at Oliktok is designed to be mobile and it may be relocated in the future to support other ARM science missions. AMF3's present instruments include: scanning precipitation Radar-cloud radar, Raman Lidar, Eddy correlation flux systems, Ceilometer, Balloon sounding system, Atmospheric Emitted Radiance Interferometer (AERI), Micro-pulse Lidar (MPL), Millimeter cloud radar along with all the standard metrological measurements. A Mobile Aerosol Observing System (MAOS) has been added to AMF3 in 2016 more details of the instrumentation at www.arm.gov/sites/amf/mobile-aos. Data from these instruments are placed in the ARM data archives and are available to the international research community. This poster will discuss what instruments are at the ARM Program's AMF3 and highlight the newest addition to AMF3, the Mobile Aerosol Observing System (MAOS).

Particle size and morphology of UHMWPE wear debris in failed total knee arthroplasties--a comparison between mobile bearing and fixed bearing knees.

PubMed

Huang, Chun-Hsiung; Ho, Fang-Yuan; Ma, Hon-Ming; Yang, Chan-Tsung; Liau, Jiann-Jong; Kao, Hung-Chan; Young, Tai-Horng; Cheng, Cheng-Kung

2002-09-01

Osteolysis induced by ultrahigh molecular weight polyethylene wear debris has been recognized as the major cause of long-term failure in total joint arthroplasties. In a previous study, the prevalence of intraoperatively identified osteolysis during primary revision surgery was much higher in mobile bearing knee replacements (47%) than in fixed bearing knee replacements (13%). We postulated that mobile bearing knee implants tend to produce smaller sized particles. In our current study, we compared the particle size and morphology of polyethylene wear debris between failed mobile bearing and fixed bearing knees. Tissue specimens from interfacial and lytic regions were extracted during revision surgery of 10 mobile bearing knees (all of the low contact stress (LCS) design) and 17 fixed bearing knees (10 of the porous-coated anatomic (PCA) and 7 of the Miller/Galante design). Polyethylene particles were isolated from the tissue specimens and examined using both scanning electron microscopy and light-scattering analyses. The LCS mobile bearing knees produced smaller particulate debris (mean equivalent spherical diameter: 0.58 microm in LCS, 1.17 microm in PCA and 5.23 microm in M/G) and more granular debris (mean value: 93% in LCS, 77% in PCA and 15% in M/G).

Mobile Cloud-Computing-Based Healthcare Service by Noncontact ECG Monitoring

PubMed Central

Fong, Ee-May; Chung, Wan-Young

2013-01-01

Noncontact electrocardiogram (ECG) measurement technique has gained popularity these days owing to its noninvasive features and convenience in daily life use. This paper presents mobile cloud computing for a healthcare system where a noncontact ECG measurement method is employed to capture biomedical signals from users. Healthcare service is provided to continuously collect biomedical signals from multiple locations. To observe and analyze the ECG signals in real time, a mobile device is used as a mobile monitoring terminal. In addition, a personalized healthcare assistant is installed on the mobile device; several healthcare features such as health status summaries, medication QR code scanning, and reminders are integrated into the mobile application. Health data are being synchronized into the healthcare cloud computing service (Web server system and Web server dataset) to ensure a seamless healthcare monitoring system and anytime and anywhere coverage of network connection is available. Together with a Web page application, medical data are easily accessed by medical professionals or family members. Web page performance evaluation was conducted to ensure minimal Web server latency. The system demonstrates better availability of off-site and up-to-the-minute patient data, which can help detect health problems early and keep elderly patients out of the emergency room, thus providing a better and more comprehensive healthcare cloud computing service. PMID:24316562

Evaluation of mobile phone addiction level and sleep quality in university students

PubMed Central

Sahin, Sevil; Ozdemir, Kevser; Unsal, Alaattin; Temiz, Nazen

2013-01-01

Objective: To determine the mobile phone addiction level in university students, to examine several associated factors and to evaluate the relation between the addiction level and sleep quality. Methods: The study is a cross-sectional research conducted on the students of the Sakarya University between 01 November 2012 and 01 February 2013. The study group included 576 students. The Problematic Mobile Phone Use Scale was used for evaluating the mobile phone addiction level and the Pittsburgh Sleep Quality Index for assessing the sleep quality. Mann-Whitney U test, Kruskal-Wallis test and Spearman’s Correlation Analysis were used for analyzing the data. Results: The study group consisted of 296 (51.4%) females and 208 (48.6%) males. The mean age was 20.83 ± 1.90 years (min:17, max:28). The addiction level was determined to be higher in the second-year students, those with poor family income, those with type A personality, those whose age for first mobile phone is 13 and below and those whose duration of daily mobile phone use is above 5 hours (p < 0.05 for each). The sleep quality worsens with increasing mobile phone addiction level (p < 0.05). Conclusion: The sleep quality worsens with increasing addiction level. It was concluded that referring the students with suspected addiction to advanced healthcare facilities, performing occasional scans for early diagnosis and informing the students about controlled mobile phone use would be useful. PMID:24353658

An Autonomous Mobile Agent-Based Distributed Learning Architecture-A Proposal and Analytical Analysis

ERIC Educational Resources Information Center

Sadiig, I. Ahmed M. J.

2005-01-01

The traditional learning paradigm involving face-to-face interaction with students is shifting to highly data-intensive electronic learning with the advances in Information and Communication Technology. An important component of the e-learning process is the delivery of the learning contents to their intended audience over a network. A distributed…

Revisiting Insider-Outsider Research in Comparative and International Education. Bristol Papers in Education: Comparative and International Studies

ERIC Educational Resources Information Center

Crossley, Michael, Ed.; Arthur, Lore, Ed.; McNess, Elizabeth, Ed.

2016-01-01

This volume recognises how many researchers across the social sciences, and in comparative and international education in particular, see themselves as insiders or outsiders or, more pertinently, shifting combinations of both, in the research process. The book revisits and problematises these concepts in an era where the global mobility of…

Getting in Touch: Use of Mobile Devices in the Elementary Classroom

ERIC Educational Resources Information Center

Ciampa, Katia; Gallagher, Tiffany L.

2013-01-01

In this single-case study, we examined the perceived influence of school-wide Apple iPod Touch integration on student learning and engagement. Data collection consisted of elementary teacher and principal interviews, as well as parent surveys. Findings revealed that there was a marked shift in teachers' and students' perceived roles when the iPod…

Perspectives on Distance Education and Social Media

ERIC Educational Resources Information Center

Powers, Lisa; Alhussain, Ruqaya; Averbeck, Clemens; Warner, Andre

2012-01-01

There is a dramatic shift in the tools that are used in today's technology-based distance education. While distance education is not new, there are new types of socially rich, mobile technologies that empower learners to be more in control of what they learn, when they learn it, and how they learn it. Students are taking more responsibility for…

The Shift of the University Paradigm and Reform of the Korean University Systems

ERIC Educational Resources Information Center

Lee, Hyun-Chong

2005-01-01

The 21st century society is characterised as a knowledge-based society, education mobility society, and cyber schooling society. This new paradigm of university enables us to restructure the university system in Korea. To establish an efficient and competitive education system, it is essential to change the current university system. Restructuring…

Marketisation and Widening Participation in English Higher Education: A Critical Discourse Analysis of Institutional Access Policy Documents

ERIC Educational Resources Information Center

McCaig, Colin

2015-01-01

This paper uses critical discourse analysis of English higher education institutions' policy statements about access to explore the changing ways that institutions have used language to shift their market positionality away from widening participation for all and the process of higher education to "fair access" (i.e. social mobility for…

Dynamic Gender Differences in a Post-Socialist Labor Market: Russia, 1991-1997

ERIC Educational Resources Information Center

Gerber, Theodore P.; Mayorova, Olga

2006-01-01

We examine how the shift from state socialism affects gender inequality in the labor market using multivariate models of employment exit, employment entry, job mobility and new job quality for 3,580 Russian adults from 1991 through 1997. Gender differences changed in a complex fashion. Relative to men, women gained greater access to employment,…

The Matter of New Media Making: An Intra-Action Analysis of Adolescents Making a Digital Book Trailer

ERIC Educational Resources Information Center

Ehret, Christian; Hollett, Ty; Jocius, Robin

2016-01-01

Representational logic cannot account for the entanglements of all that matters in making new media: feeling bodies, vibrant matter, feeling bodies and vibrant matter all moving and at different rates. In the currently shifting communicative landscape, where mobile technologies are the primary means for youths' digital production, all this…

What Are More Effective in English Classrooms: Textbooks or Podcasts?

ERIC Educational Resources Information Center

Selwood, Jaime; Lauer, Joe; Enokida, Kazumichi

2016-01-01

In the 21st century it has become clear that more and more language-learning pedagogical materials have begun to shift to a digital mobile-access format and away from being a textbook and classroom based one. High quality language-learning podcasts can provide a cheap, beneficial and portable technology that allows learners the freedom to access…

The Egg The Cart The Horse The Chicken: Cyberwriting, Sound, Intermedia.

ERIC Educational Resources Information Center

Smith, Hazel; Dean, Roger T.

2002-01-01

Focuses on the way new technologies are shifting page-based notions of literature. Argues hyperlinking and animation allow for new kinds of textual structure and linguistic mobility. Suggests the merging of words, sound, and visual image within the domain of the computer can create new types of meaning through semiotic juxtaposition and exchange.…

Synthetic and Biomass Alternate Fueling in Aviation

NASA Technical Reports Server (NTRS)

Hendricks, Robert C.; Bushnell, Dennis M.

2009-01-01

Must use earth's most abundant natural resources - Biomass, Solar, Arid land (43%), Seawater (97%) with nutrients (80%) plus brackish waters and nutrients resolve environmental triangle of conflicts energy-food-freshwater and ultrafine particulate hazards. Requires Paradigm Shift - Develop and Use Solar* for energy; Biomass for aviation and hybrid-electric-compressed air mobility fueling with transition to hydrogen long term.

Choosing the Arts: The Moral Regulation of Parents in the Educational Marketplace

ERIC Educational Resources Information Center

Saifer, Adam; Gaztambide-Fernández, Rubén

2017-01-01

The neoliberal turn in public education positions the parent as a consumer within an expanding educational marketplace. This shift is premised on the notion that the free market is best suited to promote equity. Critics of this claim highlight how a larger choice arena creates additional opportunities for privileged parents to mobilize their…